Sample records for small medical cyclotron

  1. BEST medical radioisotope production cyclotrons

    SciTech Connect

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

    2013-04-19

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

  2. 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.

  3. Development of a Medical Cyclotron Production Facility

    SciTech Connect

    Allen, Danny R. [CEO: NuTech Cyclotron Technologies, LLC, Tyler, Texas (United States)

    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.

  4. Rotatable superconducting cyclotron adapted for medical use

    DOEpatents

    Blosser, Henry G. (East Lansing, MI); Johnson, David A. (Williamston, MI); Riedel, Jack (East Lansing, MI); Burleigh, Richard J. (Berkeley, CA)

    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.

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

    PubMed

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

    2014-02-01

    A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H- ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 ?A/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 0.3??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 ?A 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. PMID:24593632

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

    SciTech Connect

    Jia, XianLu, E-mail: jiaxl@ciae.ac.cn; Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang [China Institute of Atomic Energy, Beijing (China)] [China Institute of Atomic Energy, Beijing (China)

    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 ?A/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 0.3??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 ?A 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H- ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 ?A/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 0.3? 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 ?A 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.

  8. 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.

  9. Neutron dose rate in the facility at the cyclotron center of Chung Shan Medical University.

    PubMed

    Lee, Jui-Ping; Chen, Chien-Yi

    2008-03-01

    The neutron dose equivalent rate (DR) leaking from the self-shielded cyclotron was measured using an FHT-751 neutron counting system in the facility at the Cyclotron Center of Chung Shan Medical University. This system was calibrated using two (252)Cf neutron sources and simulated according to MCNP code. The results show various DRs up to 120 microSv h(-1) in the cyclotron room. Two-dimensional distributions of measured neutron DRs indicate an explicit, heavy leakage of neutrons through the self-shielded interlock. The neutron DR of the operating cyclotron that is hazardous to the health of medical personal and the public is evaluated. PMID:18303178

  10. Miniature cyclotron resonance ion source using small permanent magnet

    NASA Technical Reports Server (NTRS)

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

    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.

  11. 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

  12. 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. PMID:20098564

  13. Medical Waste Management Implications for Small Medical Facilities.

    ERIC Educational Resources Information Center

    Byrns, George; Burke, Thomas

    1992-01-01

    Discusses the implications of the Medical Waste Management Act of 1988 for small medical facilities, public health, and the environment. Reviews health and environmental risks associated with medical waste, current regulatory approaches, and classifications. Concludes that the health risk of medical wastes has been overestimated; makes…

  14. Integrated medical informatics with small group teaching in medical education

    Microsoft Academic Search

    Heng-Shuen Chen; Fei-Ran Guo; Chien-Tsai Liu; Yue-Joe Lee; Jye-Horng Chen; Chia-Chin Lin; Sheng-Mou Hou; Bor-Shen Hsieh

    1998-01-01

    National Taiwan University College of Medicine (NTUCM) introduced small groups of teaching and basic-clinical integrated courses for medical students in 1992. By using computer network and multimedia techniques, this study tried to overcome barriers to learning in small group teaching. The Department of Medical Informatics of NTUCM established campus networking and computer classrooms and provided Internet and intranet network services

  15. A small cold cathode heavy ion source for a compact cyclotron

    Microsoft Academic Search

    T. Yamaya; T. Shinozuka; K. Kotajima; M. Fujioka; T. Onodera

    1984-01-01

    A small cold cathode PIG ion source for multiply charged heavy ions was developed for the compact cyclotron of Tohoku University, and the performance was examined with H2, CO2, CH4, O2, Ne and Ar gases. The beam currents of 12C4+,5+, 14N4+,5+,6+, 16O5+,6+ and 20Ne5+ ions were measured at the cyclotron extraction radius. Design considerations and characteristics of this ion source

  16. 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.

  17. A real-time intercepting beam-profile monitor for a medical cyclotron

    SciTech Connect

    Hendriks, C.; Uittenbosch, T.; Cameron, D.; Kellogg, S.; Gray, D.; Buckley, K.; Schaffer, P.; Verzilov, V.; Hoehr, C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada)] [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada)

    2013-11-15

    There is a lack of real-time continuous beam-diagnostic tools for medical cyclotrons due to high power deposition during proton irradiation. To overcome this limitation, we have developed a profile monitor that is capable of providing continuous feedback about beam shape and current in real time while it is inserted in the beam path. This enables users to optimize the beam profile and observe fluctuations in the beam over time with periodic insertion of the monitor.

  18. Integrated medical informatics with small group teaching in medical education.

    PubMed

    Chen, H S; Guo, F R; Liu, C T; Lee, Y J; Chen, J H; Lin, C C; Hou, S M; Hsieh, B S

    1998-06-01

    National Taiwan University College of Medicine (NTUCM) introduced small groups of teaching and basic-clinical integrated courses for medical students in 1992. By using computer network and multimedia techniques, this study tried to overcome barriers to learning in small group teaching. The Department of Medical Informatics of NTUCM established campus networking and computer classrooms and provided Internet and intranet network services including mail, netnews, bulletin board systems (BBS), world wide web (WWW), gopher, ftp and local file servers. To implement an interactive learning environment, the authors first tried mail lists, newsgroups and BBS. Next an integrated learning system prototype on the WWW was developed to provide functions including online syllabus, discussion boards simulated to BBS, online talk, interactive case studies, virtual classroom with video on demand (VOD) and Internet medical resources. The results showed that after the medical students completed the required course of medical informatics and had good network access using a network to communicate with each other became a daily practice. In the future, the system will extend to the tutoring of clinical practice and continuing medical education. The authors expect a national medical education network and more international cooperation and exchange. PMID:9726493

  19. Automated cyclotron tuning using beam phase measurements

    Microsoft Academic Search

    J. H. Timmer; H. Röcken; T. Stephani; C. Baumgarten; A. Geisler

    2006-01-01

    The ACCEL K250 superconducting cyclotron is specifically designed for the use in proton therapy systems. The compact medical 250MeV proton accelerator fulfils all present and future beam requirements for fast scanning treatment systems and is delivered as a turn key system; no operator is routinely required. During operation of the cyclotron heat dissipation of the RF system induces a small

  20. A CYCLOTRON CONCEPT TO SUPPORT ISOTOPE PRODUCTION FOR SCIENCE AND MEDICAL APPLICATIONS

    SciTech Connect

    Egle, Brian [ORNL] [ORNL; Mirzadeh, Saed [ORNL] [ORNL; Tatum, B Alan [ORNL] [ORNL; Varma, Venugopal Koikal [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Bradley, Eric Craig [ORNL] [ORNL; Burgess, Thomas W [ORNL] [ORNL; Aaron, W Scott [ORNL] [ORNL; Binder, Jeffrey L [ORNL] [ORNL; Beene, James R [ORNL] [ORNL; Saltmarsh, Michael John [ORNL] [ORNL

    2013-01-01

    In August of 2009, the Nuclear Science Advisory Committee (NSAC) recommended a variable-energy, high-current multi-particle accelerator for the production of medical radioisotopes. The Oak Ridge National Laboratory is developing a technical concept for a 70 MeV dual-extraction multi-particle cyclotron that will meet the needs identified in the NSAC report. The cyclotron, which will be located at the Holifield Radioactive Ion Beam Facility (HRIBF), will operate on a 24/7 basis and will provide approximately 6000 hours per year of quality beam time for both the production R&D and production of medical and industrial radioisotopes. The proposed cyclotron will be capable of accelerating dual beams of 30 to 70 MeV H at up to 750 A, and up to 50 A of 15-35 MeV D , 35 MeV H2, and 70 MeV -particles. In dual-extraction H mode, a total of 750 A of 70 MeV protons will be provided simultaneously to both HRIBF and Isotope Production Facility. The isotope facility will consist of two target stations: a 2 water-cooled station and a 4 water-cooled high-energy-beam research station. The multi-particle capability and high beam power will enable research into new regimes of accelerator-produced radioisotopes, such as 225Ac, 211At, 68Ge, and 7B. The capabilities of the accelerator will enable the measurement of excitation functions, thick target yield measurements, research in high-power-target design, and will support fundamental research in nuclear and radiochemistry.

  1. Selected Reference Aids for Small Medical Libraries *

    PubMed Central

    Duncan, Howertine Farrell

    1970-01-01

    This annotated list of 178 items is compiled as a guide to the development of the reference collection in a small medical library. Arrangement, following the pattern of the previous revision, is by broad subject groups. Titles are chiefly in English. Textbooks in subject fields have been omitted since these are covered adequately in several comprehensive guides to the literature. PMID:5439904

  2. Initial experience with an 11 MeV self-shielded medical cyclotron on operation and radiation safety

    PubMed Central

    Pant, G. S.; Senthamizhchelvan, S.

    2007-01-01

    A self-shielded medical cyclotron (11 MeV) was commissioned at our center, to produce positron emitters, namely, 18F, 15O, 13N and 11C for positron emission tomography (PET) imaging. Presently the cyclotron has been exclusively used for the production of 18F- for 18F-FDG imaging. The operational parameters which influence the yield of 18F- production were monitored. The radiation levels in the cyclotron and radiochemistry laboratory were also monitored to assess the radiation safety status in the facility. The target material, 18O water, is bombarded with proton beam from the cyclotron to produce 18F- ion that is used for the synthesis of 18F-FDG. The operational parameters which influence the yield of 18F- were observed during 292 production runs out of a total of more than 400 runs. The radiation dose levels were also measured in the facility at various locations during cyclotron production runs and in the radiochemistry laboratory during 18F-FDG syntheses. It was observed that rinsing the target after delivery increased the number of production runs in a given target, as well as resulted in a better correlation between the duration of bombardment and the end of bombardment 18F- activity with absolutely clean target after being rebuilt. The radiation levels in the cyclotron and radiochemistry laboratory were observed to be well within prescribed limits with safe work practice. PMID:21157531

  3. Evaluating secondary neutron doses of a refined shielded design for a medical cyclotron using the TLD approach

    NASA Astrophysics Data System (ADS)

    Lin, Jye-Bin; Tseng, Hsien-Chun; Liu, Wen-Shan; Lin, Ding-Bang; Hsieh, Teng-San; Chen, Chien-Yi

    2013-11-01

    An increasing number of cyclotrons at medical centers in Taiwan have been installed to generate radiopharmaceutical products. An operating cyclotron generates immense amounts of secondary neutrons from reactions such the 18O(p, n)18F, used in the production of FDG. This intense radiation can be hazardous to public health, particularly to medical personnel. To increase the yield of 18F-FDG from 4200 GBq in 2005 to 48,600 GBq in 2011, Chung Shan Medical University Hospital (CSMUH) has prolonged irradiation time without changing the target or target current to meet requirements regarding the production 18F. The CSMUH has redesigned the CTI Radioisotope Delivery System shield. The lack of data for a possible secondary neutron doses has increased due to newly designed cyclotron rooms. This work aims to evaluate secondary neutron doses at a CTI cyclotron center using a thermoluminescent dosimeter (TLD-600). Two-dimensional neutron doses were mapped and indicated that neutron doses were high as neutrons leaked through self-shielded blocks and through the L-shaped concrete shield in vault rooms. These neutron doses varied markedly among locations close to the H218O target. The Monte Carlo simulation and minimum detectable dose are also discussed and demonstrated the reliability of using the TLD-600 approach. Findings can be adopted by medical centers to identify radioactive hot spots and develop radiation protection.

  4. Basic Reference Aids for Small Medical Libraries *

    PubMed Central

    Blair, Edith D.

    1967-01-01

    Selected primarily for the small medical library, this list is compiled to serve as a practical guide for the librarian in developing and utilizing an effective reference collection. Arrangement is by broad subject groups; titles chosen are chiefly in English with geographic coverage limited to the United States and Canada. Texts in subject fields have been omitted since these are adequately covered in several comprehensive guides to the literature. PMID:6041827

  5. Decommissioning procedures for an 11 MeV self-shielded medical cyclotron after 16 years of working time.

    PubMed

    Calandrino, R; del Vecchio, A; Savi, A; Todde, S; Griffoni, V; Brambilla, S; Parisi, R; Simone, G; Fazio, F

    2006-06-01

    The present article describes the decommissioning of a compact, self-shielded, 11 MeV medical cyclotron. A Monte Carlo simulation of the possible nuclear reactions was performed in order to plan the decommissioning activities. In the course of the cyclotron dismantling, cyclotron components, shields, and floor concrete samples were measured. Residual activities were analyzed with a Ge(Li) detector and compared with simulation data. Doses to staff involved in the decommissioning procedure were monitored by individual TL dosimeters. The simulations identified five radioactive nuclides in shields and floor concrete: 55Fe and 45Ca (beta emitters, total specific activity: 2.29 x 10(4) Bq kg) and 152Eu, 154Eu, 60Co (gamma emitters, total specific activity: 1.62 x 10(3) Bq kg-1). Gamma-ray spectrometry confirmed the presence of gamma emitters, corresponding to a total specific activity of 3.40 x 10(2) Bq kg-1. The presence of the radioisotope 124Sb in the lead contained in the shield structure, corresponding to a simulated specific activity of 9.38 x 10(3) Bq kg-1, was experimentally confirmed. The measured dose from external exposure of the involved staff was <20 muSv, in accordance with the expected range of values between 10 and 20 muSv. The measured dose from intake was negligible. Finally, the decommissioning of the 11 MeV cyclotron does not represent a risk for the involved staff, but due to the presence of long-lived radioisotopes, the cyclotron components are to be treated as low level radioactive waste and stored in an authorized storage area. PMID:16691108

  6. Measurements of activation products associated with Havar foils from a GE PETtrace medical cyclotron using high resolution gamma spectroscopy.

    PubMed

    Manickam, Vivek; Brey, Richard R; Jenkins, Peter A; Christian, Paul E

    2009-02-01

    Havar foils are specially engineered for beam-line windows used in the General Electric (GE) PETtrace medical cyclotron that can withstand the high pressure differentials and also temperatures developed near the target with proton bombardment. These foils effectively separate components along the beam line of the cyclotron. Various activation products are produced in the foils from the primary proton beam and other secondary radiations. An accurate estimate of the activation products is necessary for the disposal of these foils. The foils were assayed using two High Purity Germanium (HPGe) detectors calibrated over a wide energy range. These were positioned at different distances (0.10 m, 0.24 m, and 1.74 m) away from the detector faces to accommodate their high activities. A summary of the anticipated relative abundance of each activation product and a scatter plot of the average exposure rate per unit charge incident on the foil vs. time post-activation are provided. A detailed spectral analysis of the foils in the energy ranges between 12 keV to 300 keV and 12 keV through 2,500 keV revealed the residual activation products 56Co, 57Co, 58Co, 54Mn, and 183Re at 264 d post-irradiation. Spectral examinations of the different foils removed between 2003 and 2005 show the same activation products regardless of the irradiation time or foil position in the target assembly. The information presented in this paper can be used along with the integrated charge incident on the foils in estimating the activity of Havar foils for the purpose of disposal. PMID:19125055

  7. Ion cyclotron range of frequencies heating of plasma with small impurity production

    DOEpatents

    Ohkawa, Tihiro (La Jolla, CA)

    1987-01-01

    Plasma including plasma ions is magnetically confined by a magnetic field. The plasma has a defined outer surface and is intersected by resonance surfaces of respective common ion cyclotron frequency of a predetermined species of plasma ions moving in the magnetic field. A radio frequency source provides radio frequency power at a radio frequency corresponding to the ion cyclotron frequency of the predetermined species of plasma ions moving in the field at a respective said resonance surface. RF launchers coupled to the radio frequency source radiate radio frequency energy at the resonance frequency onto the respective resonance surface within the plasma from a plurality of locations located outside the plasma at such respective distances from the intersections of the respective resonance surface and the defined outer surface and at such relative phases that the resulting interference pattern provides substantially null net radio frequency energy over regions near and including substantial portions of the intersections relative to the radio frequency energy provided thereby at other portions of the respective resonance surface within the plasma.

  8. An interactional approach to conceptualising small talk in medical interactions

    PubMed Central

    Hudak, Pamela L.; Maynard, Douglas W.

    2013-01-01

    In medical interactions, it may seem straightforward to identify ‘small talk’ as casual or social talk superfluous to the institutional work of dealing with patients’ medical concerns. Such a broad characterisation is, however, extremely difficult to apply to actual talk, and more specificity is necessary to pursue analyses of how small talk is produced and what it achieves for participants in medical interactions. We offer an approach to delineating a subgenre of small talk called topicalised small talk (TST), derived on the basis of conversation analytically-informed analyses of routine consultations involving orthopaedic surgeons and older patients. TST is a line of talk that is referentially independent from their institutional identities as patients or surgeons, oriented instead to an aspect of the personal biography of one (or both), or to some neutral topic available to interactants in any setting (e.g. weather). Importantly, TST is an achievement of both patient and surgeon in that generation and pursuit of topic is mutually accomplished. In an exploratory but systematic analysis, when this approach was applied to a purposive sample of surgeon-patient interactions, TST was much more prevalent in visits with White than African American patients. Accounts for possible ethnic differences in TST are suggested. PMID:21545445

  9. Effect of imperfections of the radial component of a magnetic field on beam dynamics in medical cyclotron C235-V3

    NASA Astrophysics Data System (ADS)

    Karamysheva, G. A.; Kostromin, S. A.; Morozov, N. A.; Samsonov, E. V.; Syresin, E. M.

    2014-11-01

    This paper presents numerical simulations and experimental results related to the effect of imperfections of the radial component of a magnetic field on the beam dynamics in the medical cyclotron C235-V3 of the Dimitrovgrad Proton Therapy Center. These imperfections in the region of the minimal axial betatron frequency lead to a transformation of coherent motion of the center of gravity of the beam to the incoherent motion of separate particles. The radial component increases the axial size of the beam by a factor of 2 at a radius of 20 cm, which produces additional losses of protons. To reduce undesirable actions of the radial component on the axial motion, the magnetic system in the central region has been optimized using two procedures: the positioning of shim correctors on sectors and selecting a special asymmetric arrangement of the upper and lower central plugs. This led to a twofold reduction in the axial size of the beam and a decrease in proton losses. Eventually, the beam transmission in C235-V3 has been increased to 72% without a limiting aperture diaphragm, which is commonly used in cyclotrons of this type. This makes it possible to reduce the irradiation dose of machine elements and increase the beam current at a deflector entrance of the cyclotron C235-V3 by a factor of 1.5 when compared to a serial C235 cyclotron.

  10. Analysis of induced radionuclides in replacement parts and liquid wastes in a medical cyclotron solely used for production of 18F for [18F]FDG.

    PubMed

    Mochizuki, S; Ishigure, N; Ogata, Y; Kobayashi, T

    2013-04-01

    Radioactivities produced in replacement parts and liquid wastes in a medical cyclotron used to produce (18)F for [(18)F]FDG with 10MeV protons were analyzed. Nineteen radionuclides were found in the replacement parts and liquid wastes. Among them, long-lived (56)Co in the Havar foils is critical in terms of radioactive waste management. The estimated dose level of exposure for the operating staff during the replacement of parts was around 310?Sv/y, which is smaller than the recommended dose limit for workers. PMID:23419430

  11. Microcomputer Systems in Solo and Small Group Medical Practices

    PubMed Central

    Bremer, Roger E.

    1978-01-01

    Technological developments of microprocessors and microcomputers will facilitate transferring the advantages of larger computer installations to solo and small group medical practices. A series of powerful forces will create the need for computer assistance, helping to overcome earlier restraints. Surveys show the physician is anxious for the help, and manufacturers have the needed advanced components under development. A typical advanced system for physical examination and clerical transactions (ASPECT) has been synthesized from the identified components at attractive economies of scale. More orderly and faster patient processing, lower costs for in-office laboratory tests, high quality, comparative diagnostic protocols, processing more patients at lower unit costs, automated administrative procedures and interface with emerging data banks are a few of the many potential benefits to the patient, the practitioner and society. Effective demonstration programs, triggering modified manufacturing and marketing patterns, are pragmatic priorities before the arsenal of these benefits can be effectively arrayed against today's greatest health care adversary - “the inflation crunch.”

  12. New considerations for compact cyclotrons

    E-print Network

    Marshall, Eric S. (Eric Scott)

    2012-01-01

    A compact cyclotron built with superconducting magnets could be a transformative solution to many scientific problems facing the defense, medical, and energy industries today. This thesis discusses three potential applications ...

  13. Factors Influencing Electronic Clinical Information Exchange in Small Medical Group Practices

    ERIC Educational Resources Information Center

    Kralewski, John E.; Zink, Therese; Boyle, Raymond

    2012-01-01

    Purpose: The purpose of this study was to identify the organizational factors that influence electronic health information exchange (HIE) by medical group practices in rural areas. Methods: A purposive sample of 8 small medical group practices in 3 experimental HIE regions were interviewed to determine the extent of clinical information exchange…

  14. Evaluation of Small-Group Teaching in Human Gross Anatomy in a Caribbean Medical School

    ERIC Educational Resources Information Center

    Chan, Lap Ki; Ganguly, Pallab K.

    2008-01-01

    Although there are a number of medical schools in the Caribbean islands, very few reports have come out so far in the literature regarding the efficacy of small-group teaching in them. The introduction of small-group teaching in the gross anatomy laboratory one and a half years ago at St. Matthew's University (SMU) on Grand Cayman appears to have…

  15. Radiation surveillance in and around cyclotron facility.

    PubMed

    Kaur, Amandeep; Sharma, Sarika; Mittal, Br

    2012-10-01

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

  16. Radiation surveillance in and around cyclotron facility

    PubMed Central

    Kaur, Amandeep; Sharma, Sarika; Mittal, BR

    2012-01-01

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

  17. Workflow and Electronic Health Records in Small Medical Practices

    PubMed Central

    Ramaiah, Mala; Subrahmanian, Eswaran; Sriram, Ram D; Lide, Bettijoyce B

    2012-01-01

    This paper analyzes the workflow and implementation of electronic health record (EHR) systems across different functions in small physician offices. We characterize the differences in the offices based on the levels of computerization in terms of workflow, sources of time delay, and barriers to using EHR systems to support the entire workflow. The study was based on a combination of questionnaires, interviews, in situ observations, and data collection efforts. This study was not intended to be a full-scale time-and-motion study with precise measurements but was intended to provide an overview of the potential sources of delays while performing office tasks. The study follows an interpretive model of case studies rather than a large-sample statistical survey of practices. To identify time-consuming tasks, workflow maps were created based on the aggregated data from the offices. The results from the study show that specialty physicians are more favorable toward adopting EHR systems than primary care physicians are. The barriers to adoption of EHR systems by primary care physicians can be attributed to the complex workflows that exist in primary care physician offices, leading to nonstandardized workflow structures and practices. Also, primary care physicians would benefit more from EHR systems if the systems could interact with external entities. PMID:22737096

  18. Selected List of Books and Journals for the Small Medical Library *

    PubMed Central

    Brandon, Alfred N.

    1967-01-01

    This updated list of 388 books and 140 journals is intended as a selection aid for the small library of a hospital, medical society, clinic, or similar organization. Books and journals are arranged by subject, with the books followed by an author index, and the journals by an alphabetical title listing. PMID:6041826

  19. Comparing Two Cooperative Small Group Formats Used with Physical Therapy and Medical Students

    ERIC Educational Resources Information Center

    D'Eon, Marcel; Proctor, Peggy; Reeder, Bruce

    2007-01-01

    This study compared "Structured Controversy" (a semi-formal debate like small group activity) with a traditional open discussion format for medical and physical therapy students. We found that those students who had participated in Structured Controversy changed their personal opinion on the topic more than those who were in the Open Discussion…

  20. National Superconducting Cyclotron Laboratory

    E-print Network

    National Superconducting Cyclotron Laboratory at Michigan State University 2008 Graduate Studies, sometimes within fractions of seconds. Experimental groups use the world leading capabilities of cyclotrons at

  1. PET - radiopharmaceutical facilities at Washington University Medical School - an overview

    SciTech Connect

    Dence, C.S.; Welch, M.J. [Washington Univ., St. Louis, MO (United States)

    1994-12-31

    The PET program at Washington University has evolved over more than three decades of research and development in the use of positron-emitting isotopes in medicine and biology. In 1962 the installation of the first hospital cyclotron in the USA was accomplished. This first machine was an Allis Chalmers (AC) cyclotron and it was operated until July, 1990. Simultaneously with this cyclotron the authors also ran a Cyclotron Corporation (TCC) CS-15 cyclotron that was purchased in 1977. Both of these cyclotrons were maintained in-house and operated with a relatively small downtime (approximately 3.5%). After the dismantling of the AC machine in 1990, a Japanese Steel Works 16/8 (JSW-16/8) cyclotron was installed in the vault. Whereas the AC cyclotron could only accelerate deuterons (6.2 MeV), the JSW - 16/8 machine can accelerate both protons and deuterons, so all of the radiopharmaceuticals can be produced on either of the two presently owned accelerators. At the end of May 1993, the medical school installed the first clinical Tandem Cascade Accelerator (TCA) a collaboration with Science Research Laboratories (SRL) of Somerville, MA. Preliminary target testing, design and development are presently under way. In 1973, the University installed the first operational PETT device in the country, and at present there is a large basic science and clinical research program involving more than a hundred staff in nuclear medicine, radiation sciences, neurology, neurosurgery, psychiatry, cardiology, pulmonary medicine, oncology, and surgery.

  2. 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 ?-particles. The ?-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.

  3. Ion Cyclotron Resonance Accelerator

    Microsoft Academic Search

    T. L. Grimm; C. T. Ramsell; R. C. York

    1997-01-01

    The Ion Cyclotron Resonance Accelerator (ICRA) is based on the operating principles of cyclotrons and gyrotrons, and should provide beam suitable for the production of radioisotopes for positron emission tomography (PET) or neutrons at a fraction of the cost of present day cyclotrons and linacs. The concept extends cyclotron resonance acceleration to ions by using a superconducting solenoid and a

  4. Selected List of Books and Journals for the Small Medical Library *

    PubMed Central

    Brandon, Alfred N.

    1969-01-01

    This updated list of 398 books and 141 journals is intended as a selection aid for the small library of a hospital, medical society, clinic, or similar organization. Books and journals are arranged by subject, with the books followed by an author index, and the journals by an alphabetical title listing. Items suggested for first purchase by smaller libraries are noted by an asterisk. PMID:4888285

  5. Selected List of Books and Journals for the Small Medical Library *

    PubMed Central

    Brandon, Alfred N.

    1971-01-01

    This updated list of 389 books and 135 journals is intended as a selection aid for the small library of a hospital, medical society, clinic, or similar organization. Books and journals are arranged by subject, with the books followed by an author index, and the journals by an alphabetical title listing. Items suggested for first purchase by smaller libraries are noted by an asterisk. PMID:5582092

  6. Development of a high current H(-) ion source for cyclotrons.

    PubMed

    Etoh, H; Aoki, Y; Mitsubori, H; Arakawa, Y; Mitsumoto, T; Yajima, S; Sakuraba, J; Kato, T; Okumura, Y

    2014-02-01

    A multi-cusp DC H(-) ion source has been designed and fabricated for medical applications of cyclotrons. Optimization of the ion source is in progress, such as the improvement of the filament configuration, magnetic filter strength, extraction electrode's shape, configuration of electron suppression magnets, and plasma electrode material. A small quantity of Cs has been introduced into the ion source to enhance the negative ion beam current. The ion source produced 16 mA of DC H(-) ion beam with the Cs-seeded operation at a low arc discharge power of 2.8 kW. PMID:24593547

  7. Open-Source Medical Devices (OSMD) Design of a Small Animal Radiotherapy System

    NASA Astrophysics Data System (ADS)

    Prajapati, S.; Mackie, T. R.; Jeraj, R.

    2014-03-01

    Open-Source Medical Devices (OSMD) was initiated with the goal of facilitating medical research by developing medical technologies including both hardware and software on an open-source platform. Our first project was to develop an integrated imaging and radiotherapy device for small animals that includes computed tomography (CT), positron emission tomography (PET) and radiation therapy (RT) modalities for which technical specifications were defined in the first OSMD conference held in Madison, Wisconsin, USA in December 2011. This paper specifically focuses on the development of a small animal RT (micro-RT) system by designing a binary micro multileaf collimator (bmMLC) and a small animal treatment planning system (SATPS) to enable intensity modulated RT (IMRT). Both hardware and software projects are currently under development and their current progresses are described. After the development, both bmMLC and TPS will be validated and commissioned for a micro-RT system. Both hardware design and software development will be open-sourced after completion.

  8. Small group effectiveness in a Caribbean medical school’s problem-based learning sessions

    PubMed Central

    2014-01-01

    Purpose: The Tutorial Group Effectiveness Instrument was developed to provide objective information on the effectiveness of small groups. Student perception of small group effectiveness during the problem base learning (PBL) process has not been previously studied in Xavier University School of Medicine (Aruba, Kingdom of the Netherlands); hence, the present study was carried out. Methods: The study was conducted among second and third semester undergraduate medical students during the last week of September 2013, at Xavier University School of Medicine of the Netherlands. Students were informed about the objectives of the study and invited to participate after obtaining written, informed consent. Demographic information like gender, age, nationality, and whether the respondent had been exposed to PBL before joining the institution was noted. Student perception about small group effectiveness was studied by noting their degree of agreement with a set of 19 statements using a Likert-type scale. Results: Thirty-four of the 37 (91.9%) second and third semester medical students participated in the study. The mean cognitive score was 3.76 while the mean motivational and de-motivational scores were 3.65 and 2.51, respectively. The median cognitive category score was 27 (maximum score 35) while the motivation score was 26 (maximum score 35) and the de-motivational score was 12 (maximum score25). There was no significant difference in scores according to respondents’ demographic characteristics. Conclusion: Student perception about small group effectiveness was positive. Since most medical schools worldwide already have or are introducing PBL as a learning modality, the Tutorial Group Effectiveness Instrument can provide valuable information about small group functioning during PBL sessions. PMID:24699510

  9. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1981-01-01

    This revised list of 539 books and 136 journals is intended as a selection guide for small or medium-sized hospital libraries or for small medical libraries in comparable health care facilities. It can also be used as a core list by consortia of small hospital libraries. Books and journals are categorized by subject; the book list is followed by an author index and the list of journals by an alphabetical title listing. Items suggested for initial purchase by smaller libraries, 137 books and 54 journals, are indicated by asterisks. To purchase the entire collection of books and to pay for annual subscriptions to all the journals would require an expenditure of about $30,000. The cost of only the asterisked items, which are recommended for first purchase, totals approximately $8,900. PMID:7225656

  10. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N

    1977-01-01

    This revised list of 472 books and 138 journals is intended as a selection guide for small or medium-sized hospital libraries or for the small medical library serving a specified clientele. It can also be used as a core list by small hospital library consortia. Books and journals are categorized by subject, with the books being followed by an author index and the journals by an alphabetical title listing. Items suggested for initial purchase by smaller libraries are indicated by an asterisk. To purchase the entire collection of books and to pay for annual subscriptions to all the journals would require an expenditure of about $18,200. The cost of only the asterisked items recommended for first purchase totals approximately $4,500. PMID:321057

  11. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1979-01-01

    This revised list of 492 books and 138 journals is intended as a selection guide for small or medium-sized hospital libraries or for the small medical library serving a specified clientele. It can also be used as a core list by small hospital library consortia. Books and journals are categorized by subject, with the books being followed by an author index and the journals by an alphabetical title listing. Items suggested for initial purchase by smaller libraries are indicated by an asterisk. To purchase the entire collection of books and to pay for annual subscriptions to all the journals would require an expenditure of about $22,500. The cost of only the asterisked items, recommended for first purchase, totals approximately $6,100. PMID:380695

  12. Factors Affecting Electronic Medical Record System Adoption in Small Korean Hospitals

    PubMed Central

    Park, Young-Taek

    2014-01-01

    Objectives The objective of this paper is to investigate the factors affecting adoption of an Electronic Medical Record (EMR) system in small Korean hospitals. Methods This study used survey data on adoption of EMR systems; data included that from various hospital organizational structures. The survey was conducted from April 10 to August 3, 2009. The response rate was 33.5% and the total number of small general hospitals was 144. Data were analyzed using the generalized estimating equation method to adjust for environmental clustering effects. Results The adoption rate of EMR systems was 40.2% for all responding small hospitals. The study results indicate that IT infrastructure (OR, 1.48; 95% CI, 1.23 to 1.80) and organic hospital structure (OR, 1.86; 95% CI, 1.07 to 3.23) rather than mechanistic hospital structure or the number of hospitals within a county (OR, 1.08; 95% CI, 1.01 to 1.17) were critical factors for EMR adoption after controlling for various hospital covariates. Conclusions This study found that several managerial features of hospitals and one environmental factor were related to the adoption of EMR systems in small Korean hospitals. Considering that health information technology produces many positive health outcomes and that an 'adoption gap' regarding information technology exists in small clinical settings, healthcare policy makers should understand which organizational and environmental factors affect adoption of EMR systems and take action to financially support small hospitals during this transition. PMID:25152831

  13. Some optimisation studies relevant to the production of high-purity 124I and 120gI at a small-sized cyclotron.

    PubMed

    Qaim, S M; Hohn, A; Bastian, Th; El-Azoney, K M; Blessing, G; Spellerberg, S; Scholten, B; Coenen, H H

    2003-01-01

    Optimisation experiments on the production of the positron emitting radionuclides 124I(T(1/2) = 4.18d) and (120g)I (T(1/2) = 1.35 h) were carried out. The TeO(2)-target technology and dry distillation method of radioiodine separation were used. The removal of radioiodine was studied as a function of time and the loss of TeO(2) from the target as a function of oven temperature and time of distillation. A distillation time of 15 min at 750 degrees C was found to be ideal. Using a very pure source and comparing the intensities of the annihilation and X-ray radiation, a value of 22.0 +/- 0.5% for the beta(+) branching in 124I was obtained. Production of 124I was done using 200 mg/cm(2) targets of 99.8% enriched 124TeO(2) on Pt-backing, 16 MeV proton beam intensities of 10 microA, and irradiation times of about 8 h. The average yield of 124I at EOB was 470 MBq(12.7 mCi). At the time of application (about 70 h after EOB) the radionuclidic impurity 123I (T(1/2) = 13.2 h) was <1%. The levels of other impurities were negligible (126I < 0.0001%;125I = 0.01%). Special care was taken to determine the 125I impurity. For the production of (120g)I only a thin 30 mg target (on 0.5 cm(2) area) of 99.9% enriched 120TeO(2) was available. Irradiations were done with 16 MeV protons for 80 min at beam currents of 7 microA. The 120gI yield achieved at EOB was 700 MBq(19 mCi), and the only impurity detected was the isomeric state 120 mI(T(1/2) = 53 min) at a level of 4.0%. The radiochemical purity of both 124I and 120gI was checked via HPLC and TLC. The radioiodine collected in 0.02 M NaOH solution existed >98% as iodide. The amount of inactive Te found in radioiodine was <1 microg. High purity 124I and 120gI can thus be advantageously produced on a medium scale using the low-energy (p,n) reaction at a small-sized cyclotron. PMID:12485666

  14. Selected List of Books and Journals for the Small Medical Library *

    PubMed Central

    Brandon, Alfred N.

    1973-01-01

    This updated list of 410 books and 136 journals is intended as a selection aid for the small library of a hospital, medical society, clinic, or similar organization. Books and journals are arranged by subject, with the books followed by an author index, and the journals by an alphabetical title listing. Items suggested for first purchase by smaller libraries are noted by an asterisk. To purchase the entire collection of books and to pay for the annual subscription costs of all the journals would require an expenditure of about $12,000. To acquire only those items suggested for first purchase, approximately $3,250 would be needed. PMID:4702804

  15. Evaluation of small-group teaching in human gross anatomy in a Caribbean medical school

    NSDL National Science Digital Library

    Dr. Lap Ki Chan (The University of Hong Kong)

    2008-01-01

    Although there are a number of medical schools in the Caribbean islands, very few reports have come out so far in the literature regarding the efficacy of small-group teaching. The introduction of small-group teaching in the gross anatomy laboratory one and a half years ago at St. Matthew's University (SMU) on Grand Cayman appears to have had a significant positive impact on the academic achievement of students in anatomy. This study surveyed the responses of the students to the small-group learning method in gross anatomy at SMU using a structured questionnaire. The results show that our students prefer this small-group learning method over a completely self-directed method in the gross anatomy lab because the study materials were carefully chosen and the study objectives were demonstrated by the resource person. However, teacher-centered teaching was deliberately avoided by fostering problem-solving skills in the anatomy lab sessions. Another aim of the small-group teaching at SMU was to develop the interpersonal and communication skills of the students, which are important in their later education and career.

  16. H- superconducting cyclotron for PET isotope production

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    The scientific design of a 14-MeV H- compact superconducting cyclotron for producing of the 18F and 13N isotopes has been developed. Main requirements to the facility as a medical accelerator are met in the design. In particular, the main requirement for the cyclotron was the smallest possible size due to the superconducting magnet. The calculations show that the proposed cyclotron allows extracted beam intensity over 500 ?A. To increase system reliability and production rates, an external H- ion source is applied. The choice of the cyclotron concept, design of the structure elements, calculation of the electromagnetic fields and beam dynamics from the ion source to the extraction system were performed.

  17. Compact superconducting 250 MeV proton cyclotron for the PSI PROSCAN proton therapy project

    Microsoft Academic Search

    M. Schillo; A. Geisler; A. Hobl; H. U. Klein; D. Krischel; M. Meyer-Reumers; C. Piel; H. Blosser; J.-W. Kim; F. Marti; J. Vincent; S. Brandenburg; J. P. M. Beijers

    2001-01-01

    A cyclotron for proton therapy has to fulfill many requirements set by the specific operational and safety needs of a medical facility and the medical environment. These are for instance high extraction efficiency, high availability and reliability, simple and robust operation. ACCEL Instruments GmbH has refined the design concept of a medical cyclotron for the PSI PROSCAN project with the

  18. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N

    1975-01-01

    This revised list of 446 books and 137 journals is intended as a selection guide for small or medium-sized hospital libraries or for the small medical library serving a specified clientele. Books and journals are categorized by subject, with the books being followed by an author index and the journals by an alphabetical title listing. Items suggested for initial purchase by smaller libraries are indicated by an asterisk. To purchase the entire collection of books and to pay for annual subscriptions to all the journals would require an expenditure for about $14,500. The cost of only the asterisked items recommended for first purchase totals approximately $4,100. PMID:1095095

  19. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1987-01-01

    The impact that the hospital librarian's use of management techniques and comprehension of the highly competitive health care environment can have on collection development and resulting information services in his or her library is reviewed in the introduction to this revised list of 600 books and 139 journals. The list is intended as a selection guide for the small or medium-size library in a hospital or comparable medical facility, or a core collection for a consortium of small hospital libraries. Books and journals are categorized by subject; the book list is followed by an author/editor index and the subject list of journals by an alphabetical title listing. Items suggested for initial purchase by smaller libraries are indicated by asterisks. To purchase the entire collection of books and to pay for 1987 subscriptions to all journals would require about $52,600. The cost of only the asterisked items totals approximately $21,000. PMID:3594025

  20. Selected list of Books and Journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1983-01-01

    The relationship of the "Selected List" to collection development is explored in the introduction to this revised list of 559 books and 135 journals. The list is intended as a selection guide for the small or medium-sized library in a hospital or comparable medical facility or as a core collection for a consortium of small hospital libraries. Books and journals are categorized by subject; the book list is followed by an author/editor index and the subject list of journals by an alphabetical title listing. Items suggested for initial purchase by smaller libraries (155 books and 54 journals) are indicated by asterisks. To purchase the entire collection of books and to pay for annual subscriptions would require an expenditure of about $38,900. The cost of only the asterisked items totals approximately $13,200. PMID:6190523

  1. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1985-01-01

    The interrelationship of print and electronic media in the hospital library and the relevance of the "Selected List" in 1985 are discussed in the introduction to this revised list of 583 books and 138 journals. The list is meant to be a selection guide for the small or medium-size library in a hospital or comparable medical facility, or a core collection for a consortium of small hospital libraries. Books and journals are categorized by subject; the book list is followed by an author/editor index and the subject list of journals by an alphabetical title listing. Items suggested for initial purchase by smaller libraries are indicated by asterisks. To purchase the entire collection of books and to pay for 1985 subscriptions to all the journals would require about $45,200. The cost of only the asterisked items totals approximately $16,100. PMID:3888331

  2. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1991-01-01

    The current financial status of the health care industry is viewed both from its effect on the hospital library collection and the response of the hospital library to the financial crisis. Predecessors of this list have been intended as selection guides for a small or medium-size library in a hospital or comparable medical facility. As the prices of books and journals continue to soar, the secondary purpose as a core collection for a consortium of small hospital libraries or a network sharing library resources may eventually become its primary use. Books (607) and journals (140) are categorized by subject; the book list is followed by an author/editor index, and the subject list of journals by an alphabetical title listing. To purchase the entire collection of books and to pay for 1991 subscriptions would require about $77,700. The cost of only the asterisked items totals $29,300. PMID:2039906

  3. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1989-01-01

    In the introduction to this revised list of 607 books and 141 journals, quality assurance programs of health care institutions and patient education are suggested as vehicles for more directly involving the hospital library and its collection in patient care. This list is intended as a selection guide for the small or medium-sized library in a hospital or comparable medical facility, or as a core collection for a consortium of small hospital libraries. Books and journals are categorized by subject; the book list is followed by an author/editor index, and the subject list of journals by an alphabetical title listing. To purchase the entire collection of books and to pay for 1989 subscriptions would require about $63,500. The cost of only the asterisked items totals $24,000. PMID:2655782

  4. Cyclotrons as mass spectrometers

    SciTech Connect

    Clark, D.J.

    1984-04-01

    The principles and design choices for cyclotrons as mass spectrometers are described. They are illustrated by examples of cyclotrons developed by various groups for this purpose. The use of present high energy cyclotrons for mass spectrometry is also described. 28 references, 12 figures.

  5. Basic steps in establishing effective small group teaching sessions in medical schools

    PubMed Central

    Meo, Sultan Ayoub

    2013-01-01

    Small-group teaching and learning has achieved an admirable position in medical education and has become more popular as a means of encouraging the students in their studies and enhance the process of deep learning. The main characteristics of small group teaching are active involvement of the learners in entire learning cycle and well defined task orientation with achievable specific aims and objectives in a given time period. The essential components in the development of an ideal small group teaching and learning sessions are preliminary considerations at departmental and institutional level including educational strategies, group composition, physical environment, existing resources, diagnosis of the needs, formulation of the objectives and suitable teaching outline. Small group teaching increases the student interest, teamwork ability, retention of knowledge and skills, enhance transfer of concepts to innovative issues, and improve the self-directed learning. It develops self-motivation, investigating the issues, allows the student to test their thinking and higher-order activities. It also facilitates an adult style of learning, acceptance of personal responsibility for own progress. Moreover, it enhances student-faculty and peer-peer interaction, improves communication skills and provides opportunity to share the responsibility and clarify the points of bafflement. PMID:24353692

  6. Basic steps in establishing effective small group teaching sessions in medical schools.

    PubMed

    Meo, Sultan Ayoub

    2013-07-01

    Small-group teaching and learning has achieved an admirable position in medical education and has become more popular as a means of encouraging the students in their studies and enhance the process of deep learning. The main characteristics of small group teaching are active involvement of the learners in entire learning cycle and well defined task orientation with achievable specific aims and objectives in a given time period. The essential components in the development of an ideal small group teaching and learning sessions are preliminary considerations at departmental and institutional level including educational strategies, group composition, physical environment, existing resources, diagnosis of the needs, formulation of the objectives and suitable teaching outline. Small group teaching increases the student interest, teamwork ability, retention of knowledge and skills, enhance transfer of concepts to innovative issues, and improve the self-directed learning. It develops self-motivation, investigating the issues, allows the student to test their thinking and higher-order activities. It also facilitates an adult style of learning, acceptance of personal responsibility for own progress. Moreover, it enhances student-faculty and peer-peer interaction, improves communication skills and provides opportunity to share the responsibility and clarify the points of bafflement. PMID:24353692

  7. Patient-Centered Medical Home Among Small Urban Practices Serving Low-Income and Disadvantaged Patients

    PubMed Central

    Berry, Carolyn A.; Mijanovich, Tod; Albert, Stephanie; Winther, Chloe H.; Paul, Margaret M.; Ryan, Mandy Smith; McCullough, Colleen; Shih, Sarah C.

    2013-01-01

    PURPOSE Research on the patient-centered medical home (PCMH) model and practice redesign has not focused on the unique challenges and strengths of very small primary care practices serving disadvantaged patient populations. We analyzed the practice characteristics, prior experiences, and dimensions of the PCMH model that exist in such practices participating in the Primary Care Information Project (PCIP) of the New York City Department of Mental Health and Hygiene. METHODS We obtained descriptive data, focusing on PCMH, for 94 primary care practices with 5 or fewer clinicians serving high volumes of Medicaid and minority patient populations in New York City. Data included information extracted from PCIP administrative data and survey data collected specifically for this study. RESULTS Survey results indicated substantial implementation of key aspects of the PCMH among small practices serving disadvantaged patient populations, despite considerable potential challenges to achieving PCMH implementation. Practices tended to use few formal mechanisms, such as formal care teams and designated care or case managers, but there was considerable evidence of use of informal team-based care and care coordination nonetheless. It appears that many of these practices achieved the spirit, if not the letter, of the law in terms of key dimensions of PCMH. CONCLUSIONS Small practices can achieve important aspects of the PCMH model of primary care, often with informal rather than formal mechanisms and strategies. The use of flexible, less formal strategies is important to keep in mind when considering implementation and assessment of PCMH-like initiatives in small practices. PMID:23690391

  8. Small Blob Identification in Medical Images Using Regional Features from Optimum Scale.

    PubMed

    Zhang, Min; Wu, Teresa; Bennett, Kevin

    2014-09-25

    Recent advances in medical imaging technology have greatly enhanced imaging based diagnosis which requires computational effective and accurate algorithms to process the images (e.g., measure the objects) for quantitative assessment. In this research, we are interested in one type of imaging object: small blobs. Examples of small blob objects are cells in histopathology images, glomeruli in MR images, etc. This problem is particularly challenging because the small blobs often have inhomogeneous intensity distribution and an indistinct boundary against the background. Yet, in general, these blobs have similar sizes. Motived by this finding, we propose a novel detector termed Hessian-based Laplacian of Gaussian (HLoG) using the scale space theory as the foundation. Like most imaging detectors, an image is first smoothed via LoG. Hessian analysis is then launched to identify the single optimal scale based on which a pre-segmentation is conducted. The advantage of the Hessian process is it is capable of delineating the blobs. As a result, regional features can be retrieved. These features enable the unsupervised clustering algorithm for post-pruning which shall be more robust and sensitive than the traditional threshold-based post-pruning commonly used in most imaging detectors. To test the performance of the proposed HLoG, two sets of 2D grey medical images are studied. HLoG is compared against three state-of-the-art detectors: gLoG, Radial-Symmetry and LoG using precision, recall and F-score metrics. We observe that HLoG statistically outperforms the compared detectors. PMID:25265624

  9. Radioisotope dating with a cyclotron.

    PubMed

    Muller, R A

    1977-04-29

    By considering radioisotope dating as a problem in trace element detection, and by using the cyclotron as a high-energy mass spectrometer for this purpose, we have shown that one can greatly increase the maximum age that can be determined while simultaneously reducing the size of the sample required. The cyclotron can be used to detect atoms or simple molecules that are present at the 10(-16) level or greater. For (14)C dating one should be able to go back 40,000 to 100,000 years with 1- to 100-mg carbon samples; for (10)Be dating, 10 to 30 million years with 1-mm(3) to 10-cm(3) rock samples; for tritium dating, 160 years with a 1-liter water sample. The feasibility of the technique has been demonstrated experimentally by measuring the tritium/deuterium ratio in a sample 24 years old. For samples many half-lives old, the fractional error in the age is small even if rates of production or deposition of the isotopes. Although cyclotrons are expensive to build, their operating costs are relatively low. If several samples are dated per hour the cost per date may not be substantially higher than it is today for decay dating. There are already more than 50 cyclotrons in operation which have the potential to do radioisotope dating, and their application to important problems of dating and trace element analysis should prove very fruitful. PMID:17837065

  10. Energy management techniques for ultra-small bio-medical implants

    E-print Network

    Sanchez, William R

    2012-01-01

    Trends in the medical industry have created a growing demand for implantable medical devices. In particular, the need to provide medical professionals a means to continuously monitor bio-markers over long time scales with ...

  11. Superconducting cyclotron: neutron source for therapy

    Microsoft Academic Search

    C. B. Bigham; H. R. Schneider

    1975-01-01

    A neutron source for medical therapy purposes is described. The cyclotron consists of: an iron metal housing acting as a magnetic yoke, magnetic shield, radiation shield, and vacuum vessel; a pair of superconducting coils mounted in a cavity in the housing, the coils being cooled to superconducting temperatures; an ion orbiting region defined by pairs of sectoral-shaped rf electrode structures

  12. Patterns of Relating Between Physicians and Medical Assistants in Small Family Medicine Offices

    PubMed Central

    Elder, Nancy C.; Jacobson, C. Jeffrey; Bolon, Shannon K.; Fixler, Joseph; Pallerla, Harini; Busick, Christina; Gerrety, Erica; Kinney, Dee; Regan, Saundra; Pugnale, Michael

    2014-01-01

    PURPOSE The clinician-colleague relationship is a cornerstone of relationship-centered care (RCC); in small family medicine offices, the clinician–medical assistant (MA) relationship is especially important. We sought to better understand the relationship between MA roles and the clinician-MA relationship within the RCC framework. METHODS We conducted an ethnographic study of 5 small family medicine offices (having <5 clinicians) in the Cincinnati Area Research and Improvement Group (CARInG) Network using interviews, surveys, and observations. We interviewed 19 MAs and supervisors and 11 clinicians (9 family physicians and 2 nurse practitioners) and observed 15 MAs in practice. Qualitative analysis used the editing style. RESULTS MAs’ roles in small family medicine offices were determined by MA career motivations and clinician-MA relationships. MA career motivations comprised interest in health care, easy training/workload, and customer service orientation. Clinician-MA relationships were influenced by how MAs and clinicians respond to their perceptions of MA clinical competence (illustrated predominantly by comparing MAs with nurses) and organizational structure. We propose a model, trust and verify, to describe the structure of the clinician-MA relationship. This model is informed by clinicians’ roles in hiring and managing MAs and the social familiarity of MAs and clinicians. Within the RCC framework, these findings can be seen as previously undefined constraints and freedoms in what is known as the Complex Responsive Process of Relating between clinicians and MAs. CONCLUSIONS Improved understanding of clinician-MA relationships will allow a better appreciation of how clinicians and MAs function in family medicine teams. Our findings may assist small offices undergoing practice transformation and guide future research to improve the education, training, and use of MAs in the family medicine setting. PMID:24615311

  13. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1995-01-01

    The complementary informational access roles of the traditional hospital library book and journal collection and the high-tech Internet are viewed from a 1995 perspective. Predecessors of this list have been intended as selection guides for a small or medium-size library in a hospital or comparable medical facility. As the prices of books and journals continue on an upward spiral, the secondary purpose as a core collection for a consortium of small hospital libraries or a network sharing library resources is fast becoming its primary use. Books (610) and journals (141) are categorized by subject; the book list is followed by an author/editor index and the subject list of journals by an alphabetical title listing. Due to requests from librarians, a "minimal core" book collection consisting of 82 titles has been pulled out from the 200 asterisked initial-purchase books. To purchase the entire collection of books and to pay for 1995 subscriptions would require $93,300. The cost of only the asterisked items totals $39,000. The "minimal core" book collection costs $12,700. PMID:7599581

  14. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1997-01-01

    The introduction to this revised list (seventeenth version) of 610 books and 141 journals addresses the origin, three decades ago, of the "Selected List of Books and Journals for the Small Medical Library," and the accomplishments of the late Alfred N. Brandon in helping health sciences librarians, and especially hospital librarians, to envision what collection development and a library collection are all about. This list is intended as a selection guide for the small or medium-size library in a hospital or similar facility. More realistically, it can function as a core collection for a library consortium. Books and journals are categorized by subject; the book list is followed by an author/editor index, and the subject list of journals by an alphabetical title listing. Due to continuing requests from librarians, a "minimal core" book collection consisting of 78 titles has been pulled out from the 200 asterisked (*) initial-purchase books and marked with daggers ([symbol: see text]). To purchase the entire collection of books and to pay for 1997 journal subscriptions would require $101,700. The cost of only the asterisked items, books and journals, totals $43,100. The "minimal core" book collection costs $12,600. PMID:9160148

  15. Magnetic trapping effects on electron cyclotron maser in magnetic mirrors

    SciTech Connect

    Lin, J.; Bian, B.D. (Department of Physics, Fuzhou University, Fuzhou 350002 (China))

    1993-02-01

    The magnetic trapping effects of weakly relativistic electron on electron cyclotron maser instability in the magnetic mirror fusion devices are studied. The integrodifferential eigenmode equation is solved perturbatively with a small part of weakly relativistic electron population. Compared with the previous local model, the results indicate that the trapped effects provide stabilization to the electron cyclotron maser propagating along the magnetic field.

  16. Initial Medical Attention on Patients with Early-Stage Non-Small Cell Lung Cancer

    PubMed Central

    Chen, Xing; Gorlov, Ivan P.; Ying, Jun; Merriman, Kelly W.; Kimmel, Marek; Lu, Charles; Reyes-Gibby, Cielito C.; Gorlova, Olga Y.

    2012-01-01

    Background Detection of early stage non-small cell lung cancer (NSCLC) is commonly believed to be incidental. Understanding the reasons that caused initial detection of these patients is important for early diagnosis. However, these reasons are not well studied. Methods We retrospectively reviewed medical records of patients diagnosed with stage I or II NSCLC between 2000 and 2009 at UT MD Anderson Cancer Center. Information on suggestive LC-symptoms or other reasons that caused detection were extracted from patients' medical records. We applied univariate and multivariate analyses to evaluate the association of suggestive LC-symptoms with tumor size and patient survival. Results Of the 1396 early stage LC patients, 733 (52.5%) presented with suggestive LC-symptoms as chief complaint. 347 (24.9%) and 287 (20.6%) were diagnosed because of regular check-ups and evaluations for other diseases, respectively. The proportion of suggestive LC-symptom-caused detection had a linear relationship with the tumor size (correlation 0.96; with p<.0001). After age, gender, race, smoking status, therapy, and stage adjustment, the symptom-caused detection showed no significant difference in overall and LC-specific survival when compared with the other (non-symptom-caused) detection. Conclusion Symptoms suggestive of LC are the number one reason that led to detection in early NSCLC. They were also associated with tumor size at diagnosis, suggesting early stage LC patients are developing symptoms. Presence of symptoms in early stages did not compromise survival. A symptom-based alerting system or guidelines may be worth of further study to benefit NSCLC high risk individuals. PMID:22412901

  17. 3D Observations of Electromagnetic Ion Cyclotron Wave Propagation in a Laboratory Plasma Column

    E-print Network

    California at Los Angles, University of

    3D Observations of Electromagnetic Ion Cyclotron Wave Propagation in a Laboratory Plasma Column The propagation of Electromagnetic Ion Cyclotron Waves (EMICW's) as launched by an antenna of small transverse digitization and storage of large data sets. Electromagnetic Ion Cyclotron Waves (EMICW's) are shear Alfvén

  18. Report on the 12-Inch Cyclotron Magnet Study: Measurements, Modeling, and Future plans.

    E-print Network

    Glashausser, Charles

    Report on the 12-Inch Cyclotron Magnet Study: Measurements, Modeling, and Future plans. Timothy W. Koeth Rutgers University, Piscataway NJ 08854 ABSTRACT: A small 12-Inch, 1.2MeV proton cyclotron has to improve the cyclotron's operation. This R&D project also affords the students a unique research experience

  19. Support and Strategies for Change Among Small Patient-Centered Medical Home Practices

    PubMed Central

    Scholle, Sarah Hudson; Asche, Stephen E.; Morton, Suzanne; Solberg, Leif I.; Tirodkar, Manasi A.; Jaén, Carlos Roberto

    2013-01-01

    PURPOSE We aimed to determine the motivations and barriers facing small practices that seek to adopt the patient-centered medical home (PCMH) model, as well as the type of help and strategies they use. METHODS We surveyed lead physicians at practices with fewer than 5 physicians, stratified by state and level of National Committee for Quality Assurance PCMH recognition, using a Web-based survey with telephone, fax, and mail follow-up. The response rate was 59%, yielding a total sample of 249 practices from 23 states. RESULTS Improving quality and patient experience were the strongest motivations for PCMH implementation; time and resources were the biggest barriers. Most practices participated in demonstration projects or received financial rewards for PCMH, and most received training or other kinds of help. Practices found training and help related to completing the PCMH application to be the most useful. Training for patients was both less common and less valued. The most commonly used strategies for practice transformation were staff training, systematizing processes of care, and quality measurement/goal setting. The least commonly endorsed strategy was involving patients in quality improvement. Practices with a higher level of PCMH recognition were more likely to have electronic health records, to report barriers, and to use measurement-based quality improvement strategies. CONCLUSIONS To spread the adoption of the PCMH model among small practices, financial support, practical training, and other help are likely to continue to be important. Few practices involved patients in their implementation, so it would be helpful to test the impact of greater patient involvement in the PCMH. PMID:23690387

  20. Brandon/Hill selected list of print books and journals for the small medical library*

    PubMed Central

    Hill, Dorothy R.; Stickell, Henry N.

    2001-01-01

    After thirty-six years of biennial updates, the authors take great pride in being able to publish the nineteenth version (2001) of the “Brandon/Hill Selected List of Print Books and Journals for the Small Medical Library.” This list of 630 books and 143 journals is intended as a selection guide for health sciences libraries or similar facilities. It can also function as a core collection for a library consortium. Books and journals are categorized by subject; the book list is followed by an author/editor index, and the subject list of journals, by an alphabetical title listing. Due to continuing requests from librarians, a “minimal core list” consisting of 81 titles has been pulled out from the 217 asterisked (*) initial-purchase books and marked with daggers (†*) before the asterisks. To purchase the entire collection of 630 books and to pay for 143 2001 journal subscriptions would require $124,000. The cost of only the asterisked items, books and journals, totals $55,000. The “minimal core list” book collection costs approximately $14,300. PMID:11337945

  1. Selected list of books and journals for the small medical library.

    PubMed Central

    Brandon, A N; Hill, D R

    1993-01-01

    The potential for the hospital library as an accepted patient-focused module is viewed in terms of both the present and the future--or no future--in the introduction to this revised recommended list of 606 books and 143 journals. Predecessors of this list have been intended as selection guides for a small or medium-size library in a hospital or comparable medical facility. Due to rapidly rising prices, the secondary purpose--a basic collection for a consortium of hospital libraries or a network sharing library resources--may eventually become its primary use. Books and journals are categorized by subject; the book list is followed by an author/editor index, and the subject list of journals by an alphabetical title listing. For the first time, a "minimal core collection" consisting of 85 books has been broken out from the 200 asterisked initial purchase books. To purchase the entire collection of books and to pay for the 1993 subscriptions would require about $87,000; the cost of only the asterisked books and journals totals $34,800. The "minimal core list" of books costs $11,600. PMID:8472001

  2. Small-scale medical waste incinerators - experiences and trials in South Africa

    SciTech Connect

    Rogers, David E.C. [Environmental Process Solutions, Process Technology Centre, Council for Scientific and Industrial Research (CSIR), P.O. Box 395, Pretoria 0001 (South Africa)]. E-mail: drogers@csir.co.za; Brent, Alan C. [Life Cycle Engineering, Department of Engineering and Technology Management, University of Pretoria, Room 4-12, Engineering 2, Pretoria 0002 (South Africa)

    2006-07-01

    Formal waste management services are not accessible for the majority of primary healthcare clinics on the African continent, and affordable and practicable technology solutions are required in the developing country context. In response, a protocol was established for the first quantitative and qualitative evaluation of relatively low cost small-scale incinerators for use at rural primary healthcare clinics. The protocol comprised the first phase of four, which defined the comprehensive trials of three incineration units. The trials showed that all of the units could be used to render medical waste non-infectious, and to destroy syringes or render needles unsuitable for reuse. Emission loads from the incinerators are higher than large-scale commercial incinerators, but a panel of experts considered the incinerators to be more acceptable compared to the other waste treatment and disposal options available in under-serviced rural areas. However, the incinerators must be used within a safe waste management programme that provides the necessary resources in the form of collection containers, maintenance support, acceptable energy sources, and understandable operational instructions for the incinerators, whilst minimising the exposure risks to emissions through the correct placement of the units in relation to the clinic and the surrounding communities. On-going training and awareness building are essential in order to ensure that the incinerators are correctly used as a sustainable waste treatment option.

  3. 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 cyclotrons, accelerating protons to 80,000 volts using less than 1,000 volts on a semi-circular accelerating electrode, now called the ''dee''. Following the discovery by J. D. Cockcroft and E. T. S. Walton of how to produce larger currents at higher voltages, Lawrence constructed the first two-dee 27-Inch (69-cm) Cyclotron, which produced protons and deuterons of 4.8 MeV. The 27-Inch Cyclotron was used extensively in early investigations of nuclear reactions involving neutrons and artificial radioactivity. In 1939, working with William Brobeck, Lawrence constructed the 60-Inch (150-cm) Cyclotron, which accelerated deuterons to 19 MeV. It was housed in the Crocker Laboratory, where scientists first made transmutations of some elements, discovered several transuranic elements, and created hundreds of radioisotopes of known elements. At the Crocker Laboratory the new medical modality called nuclear medicine was born, which used radioisotopes for diagnosis and treatment of human diseases. In 1939 Lawrence was awarded the Nobel Prize in Physics, and later element 103 was named ''Lawrencium'' in his honor.

  4. Medical Engineering Education for Engineers Working in Small & Medium Sized Enterprise

    NASA Astrophysics Data System (ADS)

    Nagai, Chiaki; Moriwaki, Toshimichi

    Medical device industry is expected to be one of the growing fields in coming years, because a large amount of medical bill expenditure becomes pressing matters to overcome in Japan?s rapidly aging society. Authors have developed medical engineering programs for SMe?s to meet these demand by the government grant under academia-industry collaboration in this region and were successful to put these programs into practice. We have two medical engineering education programs in Kobe-Kansai region, one is by graduate school of Kobe University, and the other is non degree program by Kobe City Industrial Promotion Foundation. Present situation of these education are described.

  5. Cyclotron Internal Ion Source with DC Extraction

    Microsoft Academic Search

    M. L. Mallory; E. D. Hudson; R. S. Lord

    1973-01-01

    This paper describes a method for increasing the intensities for heavy ion beams accelerated in isochronous cyclotrons at high harmonics (h¿5) of the orbit frequency. Normally, only small intensities are obtained at high harmonics because of the low effective accelerating voltage between the ion source and the puller electrode. We have developed and tested a dc ion extraction system for

  6. The Story of a Small Campaign: The Medical Arrangements during the Burma Rebellion, 1931

    PubMed Central

    West, J. W.

    1933-01-01

    (1) A general description of Burma, its climate and seasons.—(2) The medical experience of former campaigns in Burma.—(3) Medical resources available and methods adopted to preserve the health of the troops, with special reference to accommodation, water supplies, malaria, heat-stroke and veneral disease. PMID:19989209

  7. Cyclotron Institute Upgrade Project

    SciTech Connect

    Clark, Henry [Texas A& M University; Yennello, Sherry [Texas A& M University; Tribble, Robert [Texas A& M University

    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.

  8. Characterization of a small chamber used for exposure to microwave radiation of small animals. Medical research progress report No. 4

    Microsoft Academic Search

    S. S. Yeandle; H. Bassen; J. R. Thomas

    1978-01-01

    The details are shown of a small inexpensive microwave irradiation chamber for exposure of rats to 2450 MHz radiation used in studies of the behavioral effects of microwave radiation. The spatial variation of the magnitude of the electric field vector and absolute calibrations of the field within the chamber are reported. During irradiation the rat was constrained in a plastic

  9. Cyclotron resonance and quasiparticles

    SciTech Connect

    Cohen, Marvin L.

    2005-01-15

    This introductory paper contains personal perspectives about the importance of cyclotron resonance in forming our modern view of solids. The papers following this one will discuss the discovery, refinements, and some of the latest developments. Although I will touch on some of these subjects, I leave the details to the other authors and in the main focus on the conceptual impact of the work. I propose that it was experiments based on cyclotron resonance which established the quasiparticle concept.

  10. Cyclotron line features from neutron star atmospheres

    NASA Technical Reports Server (NTRS)

    Wang, John C. L.; Wasserman, Ira M.; Salpeter, Edwin E.

    1989-01-01

    Cyclotron line features from the polar cap plasmas of accreting magnetized neutron stars are modeled. The polar cap environment is modeled by a homogeneous isothermal plane-parallel slab threaded by a uniform superstrong magnetic field oriented orthogonal to the slab. Two physical cyclotron photon source functions are used. For conventional stopping depths, the emergent line spectra are fairly independent of the source functions. For hot atmospheres the details of the line transfer using relativistic kinematics differ substantially from those using nonrelativistic kinematics. Aside from finite recoil, both a finite natural linewidth and conventional stopping depths suppress the escape of photons blueward of line center and potential line features tend to be smeared out into the low-energy continuum. The formation of a line features is most favorable in low-field high-temperature atmospheres where cyclotron photon production is confined to a layer of small column density.

  11. In Comparative Analysis for Fuel Burnup of Fuel Assembly Designs for the 300 kW Small Medical Reactor

    NASA Astrophysics Data System (ADS)

    Sambuu, Odmaa; Nanzad, Norov

    2009-03-01

    A 300 kW small medical reactor was designed to be used for boron neutron capture therapy (BNCT) at KAIST in 1996 [1]. In this paper, analysis for the core life cycle of the original design of the BNCT facility and modifications of the fuel assembly configuration and enrichment to get a proper life cycle were performed and a criticality, neutron flux distribution and fuel burnup calculations were carried out.

  12. The Role of International Medical Graduates in America?s Small Rural Critical Access Hospitals

    ERIC Educational Resources Information Center

    Hagopian, Amy; Thompson, Matthew J.; Kaltenbach, Emily; Hart, L. Gary

    2004-01-01

    Critical access hospitals (CAHs) are a federal Medicare category for isolated rural facilities with 15 or fewer acute care beds that receive cost-based reimbursement from Medicare. Purpose: This study examines the role of foreign-born international medical graduates (IMGs) in the staffing of CAHs. Methods: Chief executive officers (CEOs) of CAH…

  13. Emittance measurements of a cold cathode internal ion source for cyclotrons

    Microsoft Academic Search

    E. Forringer; H. G. Blosser

    2001-01-01

    Studies of the emittance and phase space density of an internal, cold cathode ion source are underway at the NSCL. The source being studied is of the same style as the one used in the Harper Medical Cyclotron [1], and planned for use in the 250 MeV superconducting cyclotron for advanced cancer therapy under development [2]. Experimental results for r-pr

  14. Cyclotron enhancement of tunneling

    NASA Astrophysics Data System (ADS)

    Medvedeva, M. V.; Larkin, I. A.; Ujevic, Sebastian; Shchur, L. N.; Ivlev, B. I.

    2008-10-01

    A state of an electron in a quantum wire or a thin film becomes metastable when a static electric field is applied perpendicular to the wire direction or the film surface. The state decays via tunneling through the created potential barrier. An additionally applied magnetic field, perpendicular to the electric field, can increase the tunneling decay rate for many orders of magnitude. This happens when the state in the wire or the film has a velocity perpendicular to the magnetic field. According to the cyclotron effect, the velocity rotates under the barrier and becomes more aligned with the direction of tunneling. This mechanism can be called cyclotron enhancement of tunneling.

  15. Petit bourgeois health care? The big small-business of private complementary medical practice.

    PubMed

    Andrews, Gavin J; Phillips, David R

    2005-05-01

    Although small business private complementary medicine (CAM) has grown to be a significant provider of health care in many Western societies, there has been relatively little research on the sector in business terms and on its wider socio-economic position and role. Using a combined questionnaire and interview survey, and the concept of small business petit bourgeoisie as a framework, this paper considers the character of therapists and their businesses in England and Wales. The findings suggest that typical of the core characteristics of both the petit bourgeoisie and therapists are the selling of goods with a considerable market viability, at the same time financial insecurity; the modest size of businesses; small amounts of direct employment generation and business owners undertaking everyday 'hands-on' work themselves. Certain of the therapists' and business characteristics depart from the stereotypical image of a small businesses class, such as the high incidence of part-time self-employment and incomes being supplemented often by unrelated waged employment. However, given the acknowledged diversity of the petit bourgeoisie between societies and over time, the framework is arguably appropriate in this context, and private CAM a latest guise. Indeed, just as the petit bourgeoisie have traditionally found market niches either neglected or rejected by bigger business, small business CAM has provided the forms of health care neglected and sometimes rejected by orthodox medicine. PMID:15955291

  16. Internal H - ion source for cyclotrons

    NASA Astrophysics Data System (ADS)

    Glazov, A.; Novikov, D.; Vasiliev, N.

    1994-04-01

    The results of experimental studies of the ion source with a cold hollow cathode for production of H- ions are presented. The cavity parameters for effective hollow cathode operation in the PIG-type of discharge have been found and a H--ion current up to 2 mA at a small gas flow rate has been obtained. The ion source can be used as an internal ion source in cyclotrons.

  17. Aiming for Prevention: Medical and Public Health Approaches to Small Arms, Gun Violence, and Injury

    Microsoft Academic Search

    Brian Rawson

    The level of global small arms violence is enormous and the scale of human suffering it causes is immense, although poorly counted. It causes at least hundreds of thousands of deaths and more than a million injuries each year, as well as permanent physical and psychological damage, destruction of families, lost productivity, and diversion of resources from basic health services.

  18. Aiming for prevention: International medical conference on small arms, gun violence and injury

    Microsoft Academic Search

    Brian Rawson

    2002-01-01

    IPPNW and Physicians for Social Responsibility, Finland organized an international conference on small arms and firearms injury in Helsinki from 28–30 September 2001, emphasizing the preventive medicine aspects of the issues discussed. This article describes the background to this conference and reports the work of IPPNW in following it up.

  19. COUPLER AND TRIMMER DESIGN FOR THE SCENT SUPERCONDUCTING CYCLOTRON

    Microsoft Academic Search

    L. A. C. Piazza; D. Battaglia; L. Calabretta; A. Caruso; M. Maggiore; D. Rifuggiato

    A superconducting cyclotron accelerating ions up to 250AMeV, for medical applications and radioactive ions production has been studied at Laboratori Nazionali del Sud in Catania (1). The radio frequency (RF) system, is based on four normal conducting radio frequency cavities operating at 93 MHz. A specific study has been done with two different 3D electromagnetic codes, Ansoft HFSS and CST

  20. Small primary care practices face four hurdles--including a physician-centric mind-set--in becoming medical homes.

    PubMed

    Nutting, Paul A; Crabtree, Benjamin F; McDaniel, Reuben R

    2012-11-01

    Transforming small independent practices to patient-centered medical homes is widely believed to be a critical step in reforming the US health care system. Our team has conducted research on improving primary care practices for more than fifteen years. We have found four characteristics of small primary care practices that seriously inhibit their ability to make the transformation to this new care model. We found that small practices were extremely physician-centric, lacked meaningful communication among physicians, were dominated by authoritarian leadership behavior, and were underserved by midlevel clinicians who had been cast into unimaginative roles. Our analysis suggests that in addition to payment reform, a shift in the mind-set of primary care physicians is needed. Unless primary care physicians can adopt new mental models and think in new ways about themselves and their practices, it will be very difficult for them and their practices to create innovative care teams, become learning organizations, and act as good citizens within the health care neighborhood. PMID:23129671

  1. Central region of SKKUCY-9 compact cyclotron

    NASA Astrophysics Data System (ADS)

    Jung, S. Y.; Kim, H. W.; Ghergherehchi, M.; Park, J. K.; Chai, J. S.; Kim, S. H.

    2014-04-01

    The development of a 9 MeV compact cyclotron for the production of radioisotopes for medical applications has been recently completed. The machine accelerates negative hydrogen ions generated from an internal PIG (Penning Ion Gauge) ion source following spiral orbits. Some of the structures designed for early beam acceleration, including a pair of center poles providing ions a circular direction, the head of the ion source, and the electrodes, are located in the center of the cyclotron. In this paper we discuss and evaluate the design of the central region that pulls the ions from the chimney of the ion source and directs them into the equilibrium orbit. The magnetic field produced by the center poles was analyzed using the magnetic solver in OPERA-3D TOSCA, and the phase error and ion equilibrium orbit, which is dependent on the kinetic energy within the designed field, were calculated using CYCLONE v8.4. The electric field produced in the acceleration gap was designed using an electrostatic solver. Then, the single beam trajectory was calculated by our own Cyclotron Beam Dynamics (CBD) code. The early orbits, vertical oscillation, acceptable RF phase and the energy gain during the early turns was evaluated. Final goal was to design the central region by the iterative optimization process and verify it with 1 MeV beam experiment.

  2. Preserving third year medical students' empathy and enhancing self-reflection using small group "virtual hangout" technology.

    PubMed

    Duke, Pamela; Grosseman, Suely; Novack, Dennis H; Rosenzweig, Steven

    2014-09-01

    Abstract Background: Medical student professionalism education is challenging in scope, purpose, and delivery, particularly in the clinical years when students in large universities are dispersed across multiple clinical sites. We initiated a faculty-facilitated, peer small group course for our third year students, creating virtual classrooms using social networking and online learning management system technologies. The course emphasized narrative self-reflection, group inquiry, and peer support. Methods: We conducted this study to analyze the effects of a professionalism course on third year medical students' empathy and self-reflection (two elements of professionalism) and their perceptions about the course. Students completed the Groningen Reflection Ability Scale (GRAS) and the Jefferson Scale of Empathy (JSE) before and after the course and provided anonymous online feedback. Results: The results of the JSE before and after the course demonstrated preservation of empathy rather than its decline. In addition, there was a statistically significant increase in GRAS scores (p?

  3. Duodenal Aspirates for Small Intestine Bacterial Overgrowth: Yield, PPIs, and Outcomes after Treatment at a Tertiary Academic Medical Center

    PubMed Central

    Franco, Diana L.; Disbrow, Molly B.; Kahn, Allon; Koepke, Laura M.; Harris, Lucinda A.; Ramirez, Francisco C.

    2015-01-01

    Duodenal aspirates are not commonly collected, but they can be easily used in detection of small intestinal bacterial overgrowth (SIBO). Proton pump inhibitor (PPI) use has been proposed to contribute to the development of SIBO. We aimed to determine the yield of SIBO-positive cultures detected in duodenal aspirates, the relationship between SIBO and PPI use, and the clinical outcomes of patients identified by this method. In a retrospective study, we analyzed electronic medical records from 1263 consecutive patients undergoing upper endoscopy at a tertiary medical center. Aspirates were collected thought out the third and fourth portions of the duodenum, and cultures were considered to be positive for SIBO if they produced more than 100,000?cfu/mL. Culture analysis of duodenal aspirates identified SIBO in one-third of patients. A significantly higher percentage of patients with SIBO use PPIs than patients without SIBO, indicating a possible association. Similar proportions of patients with SIBO improved whether or not they received antibiotic treatment, calling into question the use of this expensive therapy for this disorder. PMID:25694782

  4. Brandon/Hill selected list of books and journals for the small medical library.

    PubMed Central

    Hill, D R

    1999-01-01

    The interrelationship of print and electronic media in the hospital library and its relevance to the "Brandon/Hill Selected List" in 1999 are addressed in the updated list (eighteenth version) of 627 books and 145 journals. This list is intended as a selection guide for the small or medium-size library in a hospital or similar facility. More realistically, it can function as a core collection for a library consortium. Books and journals are categorized by subject; the book list is followed by an author/editor index, and the subject list of journals by an alphabetical title listing. Due to continuing requests from librarians, a "minimal core" book collection consisting of 82 titles has been pulled out from the 214 asterisked (*) initial-purchase books and marked with daggers ([symbol: see text]). To purchase the entire collection of books and to pay for 1999 journal subscriptions would require $114,900. The cost of only the asterisked items, books and journals, totals $49,100. The "minimal core" book collection costs $13,200. PMID:10219475

  5. Cyclotron resonance of trilayer graphene

    NASA Astrophysics Data System (ADS)

    Sena, S. H. R.; Pereira, J. M., Jr.; Farias, G. A.; Peeters, F. M.

    2012-08-01

    The cyclotron resonance energies, the corresponding oscillator strengths, and the cyclotron absorption spectrum for trilayer graphene are calculated for both ABA and ABC stacking. A gate potential across the stacked layers leads to (1) a reduction of the transition energies, (2) a lifting of the degeneracy of the zero Landau level, and (3) the removal of the electron-hole symmetry.

  6. Experiments on Ion Cyclotron Waves

    Microsoft Academic Search

    W. M. Hooke; F. H. Tenney; M. H. Brennan; H. M. Hill Jr.; T. H. Stix

    1961-01-01

    Experiments were performed on the generation of ion cyclotron waves and ; their propagation into a magnetic beach. The experiments were carried out on the ; B-66 machine, which is currently a magnetic mirror device. Studies of the ; production of neutrons have provided evidence for the absorption of the energy of ; these waves via ion cyclotron damping. Microwave

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

    NASA Astrophysics Data System (ADS)

    Fišer, M.; Kopi?ka, K.; Hradilek, P.; Han?, 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.

  8. 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.

  9. Ion cyclotron resonance cell

    DOEpatents

    Weller, Robert R. (Aiken, SC)

    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.

  10. Use of Modified SOAP Notes and Peer-led Small-group Discussion in a Medical Physiology Course: Addressing the Hidden Curriculum

    NSDL National Science Digital Library

    PhD Jonathan Kibble (St. George's University Department of Physiology and Neuroscience)

    2006-12-01

    Peer leading of small-group discussion of cases; use of modified subjective, objective, assessment of physiology (SOAP) notes; and opportunities for self-assessment were introduced into a Medical Physiology course to increase students'' awareness and practice of professional behaviors

  11. Use of Modified SOAP Notes and Peer-Led Small-Group Discussion in a Medical Physiology Course: Addressing the Hidden Curriculum

    ERIC Educational Resources Information Center

    Kibble, Jonathan; Hansen, Penelope A.; Nelson, Loren

    2006-01-01

    Peer leading of small-group discussion of cases; use of modified subjective, objective, assessment of physiology (SOAP) notes; and opportunities for self-assessment were introduced into a Medical Physiology course to increase students' awareness and practice of professional behaviors. These changes arose from faculty members' understanding of the…

  12. An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy

    NASA Astrophysics Data System (ADS)

    Cao, Yun; Li, Jia Qing; Sun, Liang Ting; Zhang, Xue Zhen; Feng, Yu Cheng; Wang, Hui; Ma, Bao Hua; Li, Xi Xia

    2014-02-01

    A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 e?A of C5+ ion beam should be extracted from the ion source, and the beam emittance better than 75 ?*mm*mrad. In recent commissioning, about 120 e?A of C5+ ion beam was got when work gas was CH4 while about 262 e?A of C5+ ion beam was obtained when work gas was C2H2 gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.

  13. Stimulated electromagnetic emission near electron cyclotron harmonics in the ionosphere

    Microsoft Academic Search

    T. B. Leyser; B. Thide; H. Derblom; A. Hedberg; B. Lundborg; P. Stubbe; H. Kopka; M. Rietveld

    1989-01-01

    Observations of electromagnetic emission stimulated by a high-frequency radio wave injected into the ionosphere from a ground-based powerful transmitter operated near harmonics of the ionospheric electron cyclotron frequency are reported. Significant changes in the spectrum of the stimulated electromagnetic radiation were obtained as the injected frequency was varied in small steps around these harmonics. The experimental results are attributed to

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

    SciTech Connect

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

    1985-12-31

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

  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. Engaging with economic evaluation methods: insights from small and medium enterprises in the UK medical devices industry after training workshops

    PubMed Central

    2012-01-01

    Background With increased governmental interest in value assessment of technologies and where medical device manufacturers are finding it increasingly necessary to become more familiar with economic evaluation methods, the study sought to explore the levels of health economics knowledge within small and medium-sized enterprises (SMEs) and to scope strategies they employ to demonstrate the value of their products to purchasers. Methods A short questionnaire was completed by participants attending one of five workshops on product development in the medical device sector that took place in England between 2007 and 2011. From all responses obtained, a large proportion of participants were based in SMEs (N?=?43), and these responses were used for the analysis. Statistical analysis using non-parametric tests was performed on questions with approximately interval scales. Qualitative data from participant responses were analysed to reveal emerging themes. Results The questionnaire results revealed that 60% of SME participants (mostly company directors or managers, including product or project managers) rated themselves as having low or no knowledge of health economics prior to the workshops but the rest professed at least medium knowledge. Clinical trials and cost analyses or cost-effectiveness studies were the most highly cited means by which SMEs aim to demonstrate value of products to purchasers. Purchasers were perceived to place most importance on factors of safety, expert opinion, cost-effectiveness and price. However many companies did not utilise formal decision-making tools to prioritise these factors. There was no significant dependence of the use of decision-making tools in general with respect to professed knowledge of health economics methods. SMEs did not state a preference for any particular aspect of potential value when deciding whether to develop a product. A majority of SMEs stated they would use a health economics tool. Research and development teams or marketing and sales departments would most likely use one. Conclusion This study points to the need for further research into the education requirements of SMEs in the area of Health Technology Assessment (HTA) and also for investigation into how SMEs engage with existing HTA processes as required by assessors such as NICE. PMID:22943625

  17. Experiments on Ion Cyclotron Waves

    Microsoft Academic Search

    W. M. Hooke; F. H. Tenney; M. H. Brennan; H. M. Hill; T. H. Stix

    1961-01-01

    Experiments have been performed on the generation of ion cyclotron waves and their propagation into a magnetic beach. The experiments were carried out on the B-66 machine, which is currently a magnetic mirror device. Studies of the production of neutrons have provided evidence for the absorption of the energy of these waves via ion cyclotron damping.Microwave phase-shift measurements have now

  18. Relativistic cyclotron resonance shape in magnetic bottle geonium

    PubMed Central

    Dehmelt, Hans; Mittleman, Richard; Liu, Yuan

    1988-01-01

    The thermally excited axial oscillation of the electron through the weak magnetic bottle needed for the continuous Stern-Gerlach effect modulates the cyclotron frequency and produces a characteristic ? 12-kHz-wide vertical rise-exponential decline line shape of the cyclotron resonance. At the same time the relativistic mass shift decreases the frequency by ? 200 Hz per cyclotron motion quantum level n. Nevertheless, our analysis of the complex line shape shows that it should be possible to produce an abrupt rise in the cyclotron quantum number n from 0 to ? 20 over a small fraction of 200 Hz, when the 160-GHz microwave drive approaches the n = 0 ? 1 transition, and a jump of 14 levels over a frequency increment of 200 Hz has already been observed in preliminary work. This realizes an earlier proposal to generate a very sharp cyclotron resonance feature by quasithermal excitation with a square noise band and should provide a way to detect spin flips when a weak bottle is used to reduce the broadening of the g - 2 resonance by a factor of 20. PMID:16578834

  19. Web-based technology: its effects on small group "problem-based learning" interactions in a professional veterinary medical program.

    PubMed

    Schoenfeld-Tacher, Regina; Bright, Janice M; McConnell, Sherry L; Marley, Wanda S; Kogan, Lori R

    2005-01-01

    The objective of this investigation was to ascertain whether and how the introduction of a new technology (WebCT) influenced faculty teaching styles while facilitating small group problem-based learning (PBL) sessions in a professional veterinary medical (PVM) program. The following questions guided the study: (1) How does the use of technology affect faculty teaching behaviors? (2) Do the facilitators' interactions with WebCT technology change over the course of one semester? (3) What is the perceived impact of WebCT on facilitators' role in PBL? The study employed a combination of qualitative (case study) and semi-quantitative (survey) methods to explore these issues. Nine clinical sciences faculty members, leading a total of six PBL groups, were observed over the course of an academic semester for a total of 20 instructional sessions. The qualitative data gathered by observing faculty as they facilitated PBL sessions yielded three major themes: (1) How do PBL facilitators adapt to the addition of WebCT technology? (2) Does this technology affect teaching? and (3) How do PBL facilitators interact with their students and each other over the course of a semester? No direct evidence was found to suggest that use of WebCT affected teaching behaviors (e.g., student-centered vs. teacher-centered instruction). However, all facilitators showed a moderate increase in comfort with the technology during the semester, and one participant showed remarkable gains in technology skills. The teaching theme provided insight into how facilitators foster learning in a PBL setting as compared to a traditional lecture. A high degree of variability in teaching styles was observed, but individuals' styles tended to remain stable over the course of the semester. Nevertheless, all facilitators interacted similarly with students, in a more caring and approachable manner, when compared to the classroom or clinic atmospheres. PMID:15834826

  20. Columbia University Varying Electron Cyclotron ResonanceVarying Electron Cyclotron Resonance

    E-print Network

    Columbia University Varying Electron Cyclotron ResonanceVarying Electron Cyclotron Resonance currently via two electron cyclotron resonance heating (ECRH) sources: 2.5 kW at 2.45 GHz and 2.5 kW at 6 discharge can be used to turn plasma instabilities on and off. #12;OutlineOutline Electron cyclotron

  1. Assistant Professor, Small Animal Critical Care/ Emergency Medicine Department of Clinical Sciences, James L. Voss Veterinary Medical Center

    E-print Network

    Birner, Thomas

    Assistant Professor, Small Animal Critical Care/ Emergency Medicine Department of Clinical Sciences/or continuous renal replacement therapy program is desirable. Specific Responsibilities Teaching · Clinical: Provide lecture and laboratory instruction in small animal critical care/emergency medicine to veterinary

  2. Helium cyclotron resonance within the earth's magnetosphere

    Microsoft Academic Search

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

    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

  3. 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.

  4. 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.

  5. CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES

    E-print Network

    Karney, Charles

    CURRENTS DRIVEN BY ELECTRON CYCLOTRON WAVES C.F.F. KARNEY, NJ. FISCH Plasma Physics Laboratory of the generation of steady-state currents by electron cyclotron waves are explored. A numerical solution of electron cyclotron wave absorption appears to be one of the more promising schemes of providing a steady

  6. Cyclotron Research Centre Universit de Lige

    E-print Network

    Wolper, Pierre

    Cyclotron Research Centre Université de Liège Christophe Phillips, Ir., PhD., c). #12;Contact Christophe Phillips Centre de Recherches du Cyclotron, B30 043662316 c.phillips@ulg.ac.be http://www.cyclotron.ulg.ac.be/ #12;#12;

  7. FAST ION STUDIES OF ION CYCLOTRON HEATING

    E-print Network

    Hammett, Greg

    FAST ION STUDIES OF ION CYCLOTRON HEATING IN THE PLT TOKAMAK Gregory Wayne Hammett;@1986 Gregory Wayne Hammett ALL RIGHTS RESERVED #12;Abstract Fast Ion Studies of Ion Cyclotron Heating to thermonuclear temperatures is the use of waves in the ion cyclotron range of frequencies. Measurements

  8. HARMONIC CYCLOTRON HEATING IN THE TOROIDAL OCTUPOLE

    E-print Network

    Sprott, Julien Clinton

    HARMONIC CYCLOTRON HEATING IN THE TOROIDAL OCTUPOLE J. C. Sprott October 1976 Plasma Studies PLP without consent of the author and maj or professor. #12;-2- Previous calculations of cyclotron resonance the harmonic cyclotron heating of both electrons and ions. It is well known (see, for example, O. Eldridge

  9. 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.

  10. The cyclotron laboratory and the RFQ accelerator in Bern

    SciTech Connect

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

    2013-07-18

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

  11. 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 ?A 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-produced 99mTc has been extensively compared with relevant United States Pharmacopeia (USP) specifications for the existing 99Mo/99mTc production strategy. Additional quality testing, including biodistribution studies of [ 99mTc]pertechnetate and [99mTc]disofenin in both mice and rabbits was also evaluated. Using the strategies and results presented throughout this dissertation, this thesis concludes with the world's first cyclotron-based 99mTc patient images obtained as part of a Phase I Clinical Trial at the University of Alberta using [99m Tc]pertechnetate.

  12. Production of the PET bone agent (18)F-fluoride ion, simultaneously with (18)F-FDG by a single run of the medical cyclotron with minimal radiation exposure- a novel technique.

    PubMed

    Kumar, Rajeev; Sonkawade, Rajendra G; Tripathi, Madhavi; Sharma, Punit; Gupta, Priyanka; Kumar, Praveen; Pandey, Anil K; Bal, Chandrasekhar; Damle, Nishikant Avinash; Bandopadhayaya, Gurupad

    2014-01-01

    Our aim was to establish an easy and convenient procedure for the preparation of fluorine-18-sodium fluoride ((18)F-NaF) for bone positron emission tomography (PET) during routine (18)F-FDG production using the Explora FDG4 radiochemistry module (EFRM) by single run of Cyclotron with negligible radiation exposure. We compared three techniques for (18)F-NaF production during routine PET radiochemistry at our setup. In one method we used synthesis module and in other two methods we did not. In the first and third method, F-18 was directly extracted from the V-vial and in the second method, (18)F-NaF was extracted by post processing from the EFRM. In the first method, F-18 was extracted directly from V-vial manually by opening the V-vial cap. In the second method, Explora FDG-4 Module was used. First, F-18 was transferred from the V-vial. Then, after post processing in EFRM, pure F-18 was obtained in the product vial. In the third method, pure F-18 was obtained in the product vial with the help of a mechanical robotic arm. The above were followed by routine quality control of (18)F-NaF produced by each method. Results of quality control of the (18)F-NaF obtained by all three methods satisfied all parameters prescribed by the United States Pharmacopeia (USP) and the British Pharmacopeia (BP) including biological, physical and chemical specifications. The radiochemical purity was 98.5±1.5% with Rf 0.006. The level of Kryptofix-222 (K222) in (18)F-NaF was within the prescribed limit. Mean pH of (18)F-NaF was 6.0±1.5. The exposure rate around the hot cell was negligible. In conclusion, from the results it was obvious that by our method number three (18)F-NaF was directly obtained from the V-vial using mechanical robotic arms. This method was the most appropriate with minimized radiation exposure to the handling Radiochemist and was also saving time as compared to the other two methods. PMID:25097896

  13. Cyclotron Radiation from Magnetic Cataclysmic Variables

    NASA Astrophysics Data System (ADS)

    Barrett, Paul Everett

    The absorption coefficient for the ordinary and extraordinary modes of wave propagation are calculated for cyclotron radiation from hot magnetized plasmas (kT < 50 keV). Two relativistic methods are used to calculate the absorption coefficients: the dielectric formulation and the single particle formulation. A nonrelativistic approximation which includes the effects of inverse-bremsstrahlung and Thomson scattering (collisions) is also made. The equations of radiative transfer for a homogeneous plasma, with large Faraday rotation, are solved, and simple analytic expressions for the Stokes parameters Q and V are derived in terms of the optical depths in both modes. The results are applied to the accretion columns of AM Herculis binaries. The inclusion of collisional effects in the nonrelativistic approximation reduces the amount of fractionally polarized light to levels which agree better with the observations. For small viewing angles with the magnetic field, the circular polarization does not approach 100% as is observed in the relativistic calculations without the effects of collisions. The polarization approaches a value much less than 100%. This result may provide a qualitative explanation of the standstill which observed in some AM Herculis binaries. Comparisons of theoretical and observational circular polarization curves for AM Herculis give surprisingly good agreement for a magnetic field of 2.7 x 10('7) gauss, temperature of 0.2 keV, and plasma slab thickness of 2.6 x 10('8) cm. The detection of cyclotron lines in the optical spectrum is limited to a small parameter space in magnetic field ((2-10) x 10('7) gauss), plasma temperature (< 15 keV), and direction of the accretion column (nearly perpendicular to the line of sight for extended periods of time; (TURN)10 minutes). Theoretical spectra confirm the conclusion by Wickramasinghe and Meggitt (1982) that the broad lines in VV Puppis are due to cyclotron emission, but dispute their conclusion that the addition of an unpolarized component of radiation in the blue and UV spectrum is required. A best fit to the data of VV Puppis yields a polar magnetic field of 3.15 x 10('7) gauss, a postshock temperature of 8.7 keV, and a dimensionless plasma parameter of (TURN)10('6).

  14. 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.

  15. Design Study of a Mini Cyclotron for the Application of Biomedical Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Kim, Jong-Won; Yun, Chong-Chul; Youn, Min-Yong; Wang, Sonjong

    2009-03-01

    A small cyclotron has been considered for the use of biomedical accelerator mass spectrometer (BAMS). Over a decade ago a few cyclotrons had been constructed and tested for AMS, but technical problems of instability and poor transmission efficiency caused to discontinue further developments. The major reason of the demise of cyclotron AMS was the dominance of commercial Tandem-based AMS facilities. Now BAMS may ask for more compact system, and perhaps using positive ions to accelerate isotope tracers is a favorable feature. The design of a cyclotron to meet the requirements of BAMS has been performed by adopting a compact magnet with high stability and a flat-topping rf system to increase transmission efficiency.

  16. Results from an exploratory study to identify the factors that contribute to success for UK medical device small- and medium-sized enterprises.

    PubMed

    Hourd, P C; Williams, D J

    2008-07-01

    This paper reports the results from an exploratory study that sets out to identify and compare the strategic approaches and patterns of business practice employed by 14 UK small- and medium-sized enterprises to achieve success in the medical device sector of the health-care industry. An interview-based survey was used to construct individual case studies of the medical device technology (MDT) companies. A cross-case analysis was performed to search for patterns and themes that cut across these individual cases. Exploratory results revealed the heterogeneity of MDT companies and the distinctive features of the MDT innovation process that emphasize the importance of a strategic approach for achieving milestones in the product development and exploitation process and for creating value for the company and its stakeholders. Recognizing the heterogeneity of MDT companies, these exploratory findings call for further investigation to understand better the influence of components of the MDT innovation process on the commercialization life cycle and value trajectory. This is required to assist start-up or spin-out MDT companies in the UK and worldwide to navigate the critical transitions that determine access to financial and consumer markets and enhance the potential to build a successful business. This will be important not only for bioscience-based companies but also for engineering-based companies aiming to convert their activities into medical devices and the health- and social-care market. PMID:18756690

  17. Proton Beam Therapy for Patients With Medically Inoperable Stage I Non-Small-Cell Lung Cancer at the University of Tsukuba

    SciTech Connect

    Nakayama, Hidetsugu, E-mail: hnakayama@pmrc.tsukuba.ac.j [Proton Medical Research Center, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki (Japan); Department of Radiation Oncology, Tsukuba Medical Center, Ibaraki (Japan); Sugahara, Shinji [Proton Medical Research Center, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki (Japan); Tokita, Mari [Department of Radiation Oncology, Alpert Medical School of Brown University, Providence, RI (United States); Satoh, Hiroaki [Department of Respiratory Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki (Japan); Tsuboi, Koji [Proton Medical Research Center, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki (Japan); Ishikawa, Shigemi [Department of Thoracic Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki (Japan); Tokuuye, Koichi [Department of Radiation Oncology, Tsukuba Medical Center, Ibaraki (Japan); Department of Radiology, Tokyo Medical University, Shinjuku, Tokyo (Japan)

    2010-10-01

    Purpose: To evaluate in a retrospective review the role of proton beam therapy for patients with medically inoperable Stage I non-small-cell lung cancer (NSCLC). Patients and Methods: From November 2001 to July 2008, 55 medically inoperable patients with Stage I NSCLC were treated with proton beam therapy. A total of 58 (T1/T2, 30/28) tumors were treated. The median age of study participants was 77 years (range, 52-86 years). A total dose of 66 GyE in 10 fractions was given to peripherally located tumors and 72.6 GyE in 22 fractions to centrally located tumors. Results: The rates (95% confidence interval) of overall and progression-free survival of all patients and of local control of all tumors at 2 years were 97.8% (93.6-102.0%), 88.7% (77.9-99.5%), and 97.0% (91.1-102.8%), respectively. There was no statistically significant difference in progression-free rate between T1 and T2 tumors (p = 0.87). Two patients (3.6%) had deterioration in pulmonary function, and 2 patients (3.6%) had Grade 3 pneumonitis. Conclusion: Proton beam therapy was effective and well tolerated in medically inoperable patients with Stage I NSCLC.

  18. 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.

  19. A Medical Research Council phase II trial of alternating chemotherapy and radiotherapy in small-cell lung cancer

    Microsoft Academic Search

    NM Bleehen; DJ Girling; A Gregor; RC Leonard; D Machin; CG McKenzie; DA Morgan; JF Smyth; MF Spittle; RJ Stephens

    1991-01-01

    In a non-randomised study in six centres in the UK, 24 patients with previously untreated small-cell lung cancer of limited extent were treated with a regimen of alternating chemotherapy and radiotherapy to assess response, toxicity, and the feasibility of applying such a regimen on a multicentre basis in the UK. The intention was to give six courses of chemotherapy on

  20. Cost-Effectiveness Analysis of Stereotactic Body Radiotherapy and Radiofrequency Ablation for Medically Inoperable, Early-Stage Non-Small Cell Lung Cancer

    SciTech Connect

    Sher, David J., E-mail: dsher@lroc.harvard.edu [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, MA (United States); Center for Outcomes and Policy Research, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, MA (United States); Wee, Jon O. [Department of Thoracic Surgery, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, MA (United States); Punglia, Rinaa S. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, MA (United States); Center for Outcomes and Policy Research, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, MA (United States)

    2011-12-01

    Purpose: The standard management of medically inoperable Stage I non-small-cell lung cancer (NSCLC) conventionally has been fractionated three-dimensional conformal radiation therapy (3D-CRT). The relatively poor local control rate and inconvenience associated with this therapy have prompted the development of stereotactic body radiotherapy (SBRT), a technique that delivers very high doses of irradiation typically over 3 to 5 sessions. Radiofrequency ablation (RFA) has also been investigated as a less costly, single-day therapy that thermally ablates small, peripheral tumors. The cost-effectiveness of these three techniques has never been compared. Methods and Materials: We developed a Markov model to describe health states of 65-year-old men with medically inoperable NSCLC after treatment with 3D-CRT, SBRT, and RFA. Given their frail state, patients were assumed to receive supportive care after recurrence. Utility values, recurrence risks, and costs were adapted from the literature. Sensitivity analyses were performed to model uncertainty in these parameters. Results: The incremental cost-effectiveness ratio for SBRT over 3D-CRT was $6,000/quality-adjusted life-year, and the incremental cost-effectiveness ratio for SBRT over RFA was $14,100/quality-adjusted life-year. One-way sensitivity analysis showed that the results were robust across a range of tumor sizes, patient utility values, and costs. This result was confirmed with probabilistic sensitivity analyses that varied local control rates and utilities. Conclusion: In comparison to 3D-CRT and RFA, SBRT was the most cost-effective treatment for medically inoperable NSCLC over a wide range of treatment and disease assumptions. On the basis of efficacy and cost, SBRT should be the primary treatment approach for this disease.

  1. Method and apparatus for ion cyclotron spectrometry

    DOEpatents

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

  2. Research Activities At The RCNP Cyclotron Facility

    SciTech Connect

    Hatanaka, Kichiji [Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki, 567-0047 Osaka (Japan)

    2010-05-12

    The Research Center for Nuclear Physics (RCNP) cyclotron cascade system has been operated to provide high quality beams for various experiments. In order to increase the physics research opportunities, the Azimuthally Varying Field (AVF) cyclotron facility was upgraded recently. A flat-topping system and an 18-GHz superconducting Electron Cyclotron Resonance (ECR) ion source were introduced to improve the beam's quality and intensity. A new beam line was installed to diagnose the characteristics of the beam to be injected into the ring cyclotron and to bypass the ring cyclotron and directly transport low energy beams from the AVF cyclotron to experimental halls. A separator is equipped to provide RI beams produced by fusion reactions at low energy and by projectile fragmentations at high energy. Development has continued to realize the designed performance of these systems.

  3. Fluid theory of beam spiraling in high intensity cyclotrons

    NASA Astrophysics Data System (ADS)

    Cerfon, Antoine; Parra, Felix; Freidberg, Jeffrey

    2012-10-01

    Novel uses of cyclotrons for basic science, national security and medical therapy applications require the production of beams with ever higher intensities. At these high intensities, uncontrolled beam loss must be minimized. To satisfy the stringent beam loss criteria, it is crucial to have a detailed understanding of the beam dynamics in high intensity cyclotrons, and more specifically, an understanding of the effects of space charge on the dynamics. Using a two-dimensional fluid description, we investigate the nonlinear radial-longitudinal dynamics of intense beams in cyclotrons. With a multiscale analysis separating the time scale associated with the betatron motion and the slower time scale associated with space-charge effects, we show that the longitudinal-radial vortex motion can be understood in the frame moving with the charged beam as the nonlinear advection of the beam by the ExB velocity field, where E is the electric field due to the space charge and B is the external magnetic field. This interpretation provides simple explanations for the stability of round beams and for the development of spiral halos in elongated beams. By numerically solving the advection equation, we show that it is also in quantitative agreement with results obtained in PIC simulations.

  4. Commissioning the chalk river superconducting cyclotron

    Microsoft Academic Search

    J. A. Hulbert; C. B. Bigham; E. A. Heighway; J. D. Hepburn; C. R. Hoffmann; J. H. Ormrod; H. R. Schneider

    1985-01-01

    The Chalk River superconducting cyclotron, when injected with beam from the Chalk River 13 MV tandem Van de Graaff accelerator, will accelerate all ions from lithium (to 50 MeV\\/u) to uranium (to 10 MeV\\/u). Following successful development trials of the cyclotron magnet and rf accelerating system and installation of the magnetic extraction channel, the cyclotron is now assembled in its

  5. CURRENTS DRIVE BY ELECTRON CYCLOTRON WAVES

    E-print Network

    Karney, Charles

    JULY 1981 CURRENTS DRIVE BY ELECTRON CYCLOTRON WAVES C,F,Fn KARNEY AND NwJ, FISCH PLASMA PHYSICS. Link: http://charles.karney.info/biblio/karney81d.html #12;Currents Driven by Electron Cyclotron Waves cyclotron waves a r e explored. A numerical solution of t h e Fokker-Planck equation is used t o v e r i f y

  6. ION CYCLOTRON RESONANCE HEATING IN WE WISCONSIN SUPPORTED TOROIDAL OCTUPOLE

    E-print Network

    Sprott, Julien Clinton

    ION CYCLOTRON RESONANCE HEATING IN WE WISCONSIN SUPPORTED TOROIDAL OCTUPOLE by J. D. Barter and J of the cyclotron resonance (lMHz powers. INIROnuCTION Wave heating in the ion cyclotron range of frequencies is becoming a recognized

  7. Conceptual design of the RF accelerating cavities for a superconducting cyclotron

    NASA Astrophysics Data System (ADS)

    Maggiore, M.; Calabretta, L.; Di Giacomo, M.; Rifuggiato, D.; Battaglia, D.; Piazza, L.

    2006-02-01

    A superconducting cyclotron accelerating ions up to 250 A MeV, for medical applications and radioactive ions production is being studied at Laboratori Nazionali del Sud in Catania. The radio frequency (RF) system, working in the fourth harmonic, is based on four normal conducting radio frequency cavities operating at 93 MHz. This paper describes an unusual multi-stem cavity design, performed with 3D electromagnetic codes. Our aim is to obtain a cavity, completely housed inside the cyclotron, with a voltage distribution ranging from 65 kV in the injection region to a peak value of 120 kV in the extraction region, and having a low power consumption.

  8. The irradiation facility at the AGOR cyclotron

    NASA Astrophysics Data System (ADS)

    Brandenburg, Sytze; Ostendorf, Reint; Hofstee, Mariet; Kiewiet, Harry; Beijers, Hans

    2007-08-01

    The KVI is conducting radiobiology research using protons up to 190 MeV from the superconducting AGOR cyclotron in collaboration with the University Medical Center Groningen (UMCG) since 1998. Using the same set-up, we have started irradiations for radiation hardness studies of detectors and components for the European Space Agency (ESA) and industrial parties. For these irradiations, we use either mono-energetic protons or a simulated solar flare energy spectrum with fluxes up to 5 × 10 8 protons cm -2 s -1. Furthermore, tests of radiation effects such as single event upsets, are being performed with intensities down to a few particles/s. Different energies are achieved by degrading the primary beam energy. We are currently developing the capability for heavy ion irradiations in air with beams up to Xe at beam energies between 15 and 45 MeV per nucleon. Performing the irradiations in air simplifies handling and monitoring of the device under test. The high energy allows penetration to the active layer of electronic devices, without modifications to the chip housing. The different ions provide a wide range in LET.

  9. Toxicity and Patterns of Failure of Adaptive/Ablative Proton Therapy for Early-Stage, Medically Inoperable Non-Small Cell Lung Cancer

    SciTech Connect

    Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Komaki, Ritsuko; Wen, Hong Y.; De Gracia, Beth; Bluett, Jaques B.; McAleer, Mary F. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Swisher, Stephen G. [Department of Thoracic/Cardiovascular Surgery, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Gillin, Michael; Mohan, Radhe [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Cox, James D. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

    2011-08-01

    Purpose: To analyze the toxicity and patterns of failure of proton therapy given in ablative doses for medically inoperable early-stage non-small cell lung cancer (NSCLC). Methods and Materials: Eighteen patients with medically inoperable T1N0M0 (central location) or T2-3N0M0 (any location) NSCLC were treated with proton therapy at 87.5 Gy (relative biological effectiveness) at 2.5 Gy /fraction in this Phase I/II study. All patients underwent treatment simulation with four-dimensional CT; internal gross tumor volumes were delineated on maximal intensity projection images and modified by visual verification of the target volume in 10 breathing phases. The internal gross tumor volumes with maximal intensity projection density was used to design compensators and apertures to account for tumor motion. Therapy consisted of passively scattered protons. All patients underwent repeat four-dimensional CT simulations during treatment to assess the need for adaptive replanning. Results: At a median follow-up time of 16.3 months (range, 4.8-36.3 months), no patient had experienced Grade 4 or 5 toxicity. The most common adverse effect was dermatitis (Grade 2, 67%; Grade 3, 17%), followed by Grade 2 fatigue (44%), Grade 2 pneumonitis (11%), Grade 2 esophagitis (6%), and Grade 2 chest wall pain (6%). Rates of local control were 88.9%, regional lymph node failure 11.1%, and distant metastasis 27.8%. Twelve patients (67%) were still alive at the last follow-up; five had died of metastatic disease and one of preexisting cardiac disease. Conclusions: Proton therapy to ablative doses is well tolerated and produces promising local control rates for medically inoperable early-stage NSCLC.

  10. Electron Cyclotron Resonance (ECR) Plasma Thruster Research

    Microsoft Academic Search

    H. Nakashima; Y. Takao; Y. Mori; K. Uemura; T. Gouda; T. Miyamoto; T. Esaki; T. Maeyama; T. Muranaka

    2000-01-01

    A study is being made on an electric propulsion system (EICR Plasma Thruster) which can generate plasma with ECRH (Electron Cyclotron Resonance Heating), accelerate ions with ICRFH (Ion Cyclotron Range of Frequency Heating) via antenna, and adopts a gradient in magnetic field to obtain thrust. The plasma thruster could achieve high power density and long lifetime since this system does

  11. Cyclotrons: From Science to Human Health

    Microsoft Academic Search

    Michael Craddock

    2011-01-01

    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

  12. Status of the Milan Superconducting Cyclotron Project

    Microsoft Academic Search

    E. Acerbi; F. Aghion; F. Alessandria; G. Baccaglioni; C. Birattari; J. Camon; C. de Martinis; E. Fabrici; D. Giove; W. Giussani; G. Gualeni; P. Michelato; L. Milinkovic; D. Pagani; E. Panzeri; F. Resmini; L. Rossi; A. Salomone; L. Serafini; G. Varisco; V. Venturini

    1983-01-01

    This paper presents an updated status report on the Superconducting Cyclotron, under construction at the University of Milan during the past two years, with funding chiefly provided by the Italian National Institute for Nuclear Physics. The cyclotron is designed for a K of 800 and a K \\/SUB FOC\\/ of 200 and thus yields maximum energies of 100 MeV\\/n for

  13. Operation of a quasioptical electron cyclotron maser

    Microsoft Academic Search

    E. C. Morse; R. V. Pyle

    1984-01-01

    The electron cyclotron maser or gyrotron concept was developed to produce sources producing 200 kW at 28 GHz continuously, and higher power outputs and frequencies in pulsed mode. These sources were useful in electron cyclotron resonance heating in magnetically confined fusion devices. Conventional gyrotrons follow a trend of decreasing power for increasing frequency. In order to circumvent this problem, the

  14. Geomagnetic cyclotron resonance in living cells

    Microsoft Academic Search

    Abraham R. Liboff

    1985-01-01

    Although considerable experimental evidence now exists to indicate that low-frequency magnetic fileds influence living cells, the mode of coupling remains a mystery. We propose a radical new model for electromagnetic interactions with cells, one resulting from a cyclotron resonance mechanism attached to ions moving through transmembrane channels. It is shown that the cyclotron resonance condition on such ions readily leads

  15. Permanent Magnet System for PET Cyclotron

    Microsoft Academic Search

    E. Antokhin; M. Kumada; Y. Iwashita; S. Wakasa; S. Matsumoto; T. Fujisawa; I. Bolhsakova; R. Holyaka; V. Erashok; E. Sugiyama; H. Shimizu

    2008-01-01

    The recent paper is devoted to design, manufacturing and testing the permanent magnet system to be used for Positron Emission Tomography (PET) cyclotron. The using permanent magnet material instead of copper coils allows essential electric power savings during PET cyclotron operation, though it comes to some increasing construction cost. The main problem why until now permanent magnets were not used

  16. 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 ?A, 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.

  17. 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.

  18. 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.

  19. Linear analysis of ion cyclotron interaction in a multicomponent plasma

    NASA Technical Reports Server (NTRS)

    Gendrin, R.; Ashour-Abdalla, M.; Omura, Y.; Quest, K.

    1984-01-01

    The mechanism by which hot anisotropic protons generate electromagnetic ion cyclotron waves in a plasma containing cold H(+) and He(+) ions is quantitatively studied. Linear growth rates (both temporal and spatial) are computed for different plasma parameters: concentration, temperature,and anisotropy of cold He(+) ions and of hot protons. It is shown that: (1) for parameters typical of the geostationary altitude the maximum growth rates are not drastically changed when a small proportion (about 1 to 20 percent) of cold He(+) ions is present; (2) because of the important cyclotron absorption by thermal He(+) ions in the vicinity of the He(+) gyrofrequency, waves which could resonate with the bulk of the He(+) distribution cannot be generated. Therefore quasi-linear effects, in a homogeneous medium at least, cannot be responsible for the heating of He(+) ions which is often observed in conjunction with ion cyclotron waves. The variation of growth rate versus wave number is also studied for its importance in selecting suitable parameters in numerical simulation experiments.

  20. 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. [Graduate School of Mechanical Engineering, Toyo University, Tokyo 112-8606, Japan and National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Department of Electrical, Electronic and Information Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary); Department of Mechanical Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-0815 (Japan); National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan and K.V.I. University of Groningen, 9747 AA Groningen (Netherlands)

    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.

  1. Experimental study of an ion cyclotron resonance accelerator

    Microsoft Academic Search

    Christopher T. Ramsell

    2000-01-01

    The Ion Cyclotron Resonance Accelerator (ICRA) uses the operating principles of cyclotrons and gyrotrons. The novel geometry of the ICRA allows an ion beam to drift axially while being accelerated in the azimuthal direction. Previous work on electron cyclotron resonance acceleration used waveguide modes to accelerate an electron beam [5]. This research extends cyclotron resonance acceleration to ions by using

  2. Cavity Control in a Single-Electron Quantum Cyclotron

    E-print Network

    Hanneke, David

    Cavity Control in a Single-Electron Quantum Cyclotron An Improved Measurement of the Electron ­ Colloquium The Quantum Cyclotron · Single electron · Resolve lowest cyclotron and spin states via QND? Frequency! B #12;Hanneke MPPL 2010 ­ Colloquium Experimenter's g · The cyclotron is an anharmonic oscillator

  3. Laser separation of medical isotopes

    Microsoft Academic Search

    J. W. Eerkens; D. A. Puglishi; W. H. Miller

    1996-01-01

    There is an increasing demand for different separated isotopes as feed material for reactor and cyclotron-produced radioisotopes used by a fast-growing radiopharmaceutical industry. One new technology that may meet future demands for medical isotopes is molecular laser isotope separation (MLIS). This method was investigated for the enrichment of uranium in the 1970`s and 1980s by Los Alamos National Laboratory, Isotope

  4. An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy.

    PubMed

    Cao, Yun; Li, Jia Qing; Sun, Liang Ting; Zhang, Xue Zhen; Feng, Yu Cheng; Wang, Hui; Ma, Bao Hua; Li, Xi Xia

    2014-02-01

    A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 e?A of C(5+) ion beam should be extracted from the ion source, and the beam emittance better than 75 ?*mm*mrad. In recent commissioning, about 120 e?A of C(5+) ion beam was got when work gas was CH4 while about 262 e?A of C(5+) ion beam was obtained when work gas was C2H2 gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper. PMID:24593539

  5. An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy

    SciTech Connect

    Cao, Yun, E-mail: caoyun@impcas.ac.cn; Li, Jia Qing; Sun, Liang Ting; Zhang, Xue Zhen; Feng, Yu Cheng; Wang, Hui; Ma, Bao Hua; Li, Xi Xia [Institute of Modern Physics, CAS, Lanzhou 730000 (China)] [Institute of Modern Physics, CAS, Lanzhou 730000 (China)

    2014-02-15

    A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 e?A of C{sup 5+} ion beam should be extracted from the ion source, and the beam emittance better than 75 ?*mm*mrad. In recent commissioning, about 120 e?A of C{sup 5+} ion beam was got when work gas was CH{sub 4} while about 262 e?A of C{sup 5+} ion beam was obtained when work gas was C{sub 2}H{sub 2} gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.

  6. Cyclotron radiation from magnetic cataclysmic variables

    NASA Astrophysics Data System (ADS)

    Barrett, P. E.

    The absorption coefficient for the ordinary and extraordinary modes of wave propagation are calculated for cyclotron radiation from hot magnetized plasmas (kT less than 50 keV). Two relativistic methods are used to calculate the absorption coefficients: the dielectric formulation and the single particle formulation. A nonrelativistic approximation which includes the effects of inverse-bremsstrahlung and Thomson scattering (collisions) is also made. The situations of radiative transfer for a homogeneous plasma, with large Faraday rotation, are solved, and simple analytic expressions for the Stokes parameters Q and V are derived in terms of the optical depths in both modes. The results are applied to the accretion columns of AM Herculis binaries. The inclusion of collisional effects in the nonrelativistic approximation reduces the amount of fractionally polarized light to levels which agree better with the observations. For small viewing angles with the magnetic field, the circular polarization does not approach 100% as is observed in the relativistic calculations without the effects of collisions.

  7. Nonlinear evolution of electromagnetic ion cyclotron waves

    SciTech Connect

    Silin, I.; Sydora, R. D.; Mann, I. R.; Sauer, K. [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada); Mace, R. L. [School of Physics, University of KwaZulu-Natal, Durban 4000 (South Africa)

    2011-04-15

    Hybrid Vlasov-Fourier modeling is used to investigate the nonlinear evolution of electromagnetic ion cyclotron (EMIC) waves driven by proton temperature anisotropy in plasmas with a population of He{sup +} ions and a cold proton background. In the pure proton-electron plasma, most of the free energy is converted into high-amplitude waves and currents. In the nonlinear stage, within a few hundred proton gyroperiods after the saturation, the wave spectrum shifts toward lower wave numbers and frequencies, from {omega}{approx}0.6{Omega}{sub p} to below {omega}{approx}0.25{Omega}{sub p}. In the presence of even a small population of He{sup +} ions almost all of the free energy is used in He{sup +} heating. The wave activity in the saturated state moves from the linearly unstable upper branch to the linearly stable lower one. In the presence of a background of cold protons, the waves can propagate in the frequency stop-band. Our results demonstrate that linear stability theory cannot be used to estimate the characteristics of the expected saturated wave spectra in the terrestrial magnetosphere. Significantly, our nonlinear simulations produce wave spectra which are in close agreement with the EMIC waves observed in situ by satellites as well as by ground-based magnetometers positioned at the ends of the magnetic field lines.

  8. Cyclotron wave instability in the corona and origin of solar radio emission with fine structure

    Microsoft Academic Search

    V. V. Zheleznyakov; E. Ya. Zlotnik

    1975-01-01

    The longitudinal waves (Bernstein modes and plasma waves near the hybrid frequency) in a mixture of equilibrium coronal plasma and a small group of energetic electrons are investigated. The energetic electrons have a nonequilibrium momentum distribution inherent in trapped particles. The frequency dependence of the cyclotron instability increments is studied. Attention is paid to a significant role of the relativistic

  9. The Impact of Tumor Size on Outcomes After Stereotactic Body Radiation Therapy for Medically Inoperable Early-Stage Non-Small Cell Lung Cancer

    SciTech Connect

    Allibhai, Zishan [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto (Canada); Taremi, Mojgan [Department of Radiation Oncology, Stronach Regional Cancer Centre, Newmarket (Canada); Bezjak, Andrea; Brade, Anthony; Hope, Andrew J.; Sun, Alexander [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto (Canada); Cho, B.C. John, E-mail: john.cho@rmp.uhn.on.ca [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto (Canada)

    2013-12-01

    Purpose: Stereotactic body radiation therapy for medically inoperable early-stage non-small cell lung cancer (NSCLC) offers excellent control rates. Most published series deal mainly with small (usually <4 cm), peripheral, solitary tumors. Larger tumors are associated with poorer outcomes (ie, lower control rates, higher toxicity) when treated with conventional RT. It is unclear whether SBRT is sufficiently potent to control these larger tumors. We therefore evaluated and examined the influence of tumor size on treatment outcomes after SBRT. Methods and Materials: Between October 2004 and October 2010, 185 medically inoperable patients with early (T1-T2N0M0) NSCLC were treated on a prospective research ethics board-approved single-institution protocol. Prescription doses were risk-adapted based on tumor size and location. Follow-up included prospective assessment of toxicity (as per Common Terminology Criteria for Adverse Events, version 3.0) and serial computed tomography scans. Patterns of failure, toxicity, and survival outcomes were calculated using Kaplan-Meier method, and the significance of tumor size (diameter, volume) with respect to patient, treatment, and tumor factors was tested. Results: Median follow-up was 15.2 months. Tumor size was not associated with local failure but was associated with regional failure (P=.011) and distant failure (P=.021). Poorer overall survival (P=.001), disease-free survival (P=.001), and cause-specific survival (P=.005) were also significantly associated with tumor size (with tumor volume more significant than diameter). Gross tumor volume and planning target volume were significantly associated with grade 2 or worse radiation pneumonitis. However, overall rates of grade ?3 pneumonitis were low and not significantly affected by tumor or target size. Conclusions: Currently employed stereotactic body radiation therapy dose regimens can provide safe effective local therapy even for larger solitary NSCLC tumors (up to 5.7 cm in tumor diameter or 100 cm{sup 3} in tumor volume) but are associated with more nonlocal failures as well as poorer survival. These observations suggest these patients may benefit from more extensive staging or consideration of adjuvant therapy.

  10. Injection and extraction for cyclotrons

    E-print Network

    Kleeven, W

    2006-01-01

    The main design goals for beam injection are explained and special problems related to a central region with internal ion source are considered. The principle of a PIG source is addressed. The issue of vertical focusing in the cyclotron centre is briefly discussed. Several examples of numerical simulations are given. Different ways of (axial) injection are briefly outlined. A proposal for a magnetostatic axial inflector is given. Different solutions for beam extraction are treated. These include the internal target, extraction by stripping, resonant extraction using a deflector and self-extraction. The different ways of creating a turn-separation are explained. The purpose of different types of extraction devices such as harmonic coils, deflectors and gradient corrector channels are outlined. Several illustrations are given in the form of photographs and drawings.

  11. Electron cyclotron resonance plasma photos

    SciTech Connect

    Racz, R.; Palinkas, J. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary); University of Debrecen, H-4010 Debrecen, Egyetem ter 1 (Hungary); Biri, S. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary)

    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. Beam on: the development of the Texas A&M Cyclotron Institute

    E-print Network

    Knudson, Jon Sven

    1982-01-01

    was wrong 1n his 1nterpretation of its structure, In 1911 Ernest Rutherford in his laboratory 1n Manchester proved that an atom 's positive charge was concentrated 1n a small core 1n lumps of electrons 0 +8 + + 0 + 0 0+ 0 + 0 0+ 8 p+ uniformly.... LIST OF FIGURES. LIST OF ACRONYMS. CHAPTER I: INTRODUCTION. TABLE OF CONTENTS Pa&ac 1V V11 The Structure of the Atom. Ernest Lawrence and the Cyclotron. A Medium Energy Cyclotron at the A&M College of Texas. . . CHAPTER II: THE TEXAS A...

  13. 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.

  14. Electron cyclotron wave generation by relativistic electrons

    NASA Technical Reports Server (NTRS)

    Wong, H. K.; Goldstein, M. L.

    1994-01-01

    We show that an energetic electron distribution which has a temperature anisotropy (T perpendicular to b is greater than T parallel to b), or which is gyrating about a DC magnetic field, can generate electron cyclotron waves with frequencies below the electron cyclotron frequency. Relativistic effects are included in solving the dispersion equation and are shown to be quantitatively important. The basic idea of the mechanism is the coupling of the beam mode to slow waves. The unstable electron cyclotron waves are predominantly electromagnetic and right-hand polarized. For a low-density plasma in which the electron plasma frequency is less than the electron cyclotron frequency, the excited waves can have frequencies above or below the electron plasma frequency, depending upon the parameters of the energetic electron distribution. This instability may account for observed Z mode waves in the polar magnetosphere of the Earth and other planets.

  15. Cyclotron axial ion-beam-buncher system

    SciTech Connect

    Hamm, R.W.; Swenson, D.A.; Wangler, T.P.

    1982-02-11

    Adiabatic ion bunching is achieved in a cyclotron axial ion injection system through the incorporation of a radio frequency quadrupole system, which receives ions from an external ion source via an accelerate-decelerate system and a focusing einzel lens system, and which adiabatically bunches and then injects the ions into the median plane of a cyclotron via an electrostatic quadrupole system and an inflection mirror.

  16. Three Phase rf Systems for Superconducting Cyclotrons

    Microsoft Academic Search

    J. Riedel

    1983-01-01

    This article describes and illustrates the three phase r.f. system for superconducting cyclotrons. It is discussed that the initial design of the MSU K500 cyclotron r.f. system has since been changed and these changes are reviewed. The author describes how, after several evolutions, there is now a successful moving short for the 6 dee stems. The stem current flowing on

  17. Cyclotron resonance heating systems for SST1

    Microsoft Academic Search

    D. Bora; Sunil Kumar; Raj Singh; K. Sathyanarayana; S. V. Kulkarni; A. Mukherjee; B. K. Shukla; J. P. Singh; Y. S. S. Srinivas; P. Khilar; M. Kushwah; Rajnish Kumar; R. Sugandhi; P. Chattopadhyay; Singh Raghuraj; H. M. Jadav; B. Kadia; Manoj Singh; Rajan Babu; P. Jatin; G. Agrajit; P. Biswas; A. Bhardwaj; D. Rathi; G. Siju; K. Parmar; A. Varia; S. Dani; D. Pragnesh; C. Virani; Harsida Patel; P. Dharmesh; A. R. Makwana; P. Kirit; M. Harsha; J. Soni; V. Yadav; D. S. Bhattacharya; M. Shmelev; V. Belousov; V. Kurbatov; Yu. Belov; E. Tai

    2006-01-01

    RF systems in the ion cyclotron resonance frequency (ICRF) range and electron cyclotron resonance frequency (ECRF) range are in an advanced stage of commissioning, to carry out pre-ionization, breakdown, heating and current drive experiments on the steady-state superconducting tokamak SST-1. Initially the 1.5 MW continuous wave ICRF system would be used to heat the SST-1 plasma to 1.0 keV during

  18. The Chalk River Heavy ion Superconducting Cyclotron

    Microsoft Academic Search

    C. R. Hoffmann; C. B. Bigham; J. S. Fraser; E. A. Heighway; J. A. Hulbert; J. H. Ormrod; H. R. Schneider

    1975-01-01

    A detailed study of an isochronous cyclotron as an energy booster accelerator for the Chalk River 13 MV MP Tandem Van de Graaff has been undertaken. The cyclotron is intended primarily for heavy ions but would accelerate all ions from Li+3 to U+33 to at least 10 MeV\\/u. NbTi superconducting coils supplemented with cylindrical iron poles provide an average magnetic

  19. Cyclotron Maser Emission from Blazar Jets?

    Microsoft Academic Search

    Mitchell C. Begelman; Robert E. Ergun; Martin J. Rees

    2005-01-01

    We consider the production of electron cyclotron maser emission by\\u000alow-density, highly magnetized plasmas in relativistic jets. The population\\u000ainversion required to drive cyclotron maser instability could occur in\\u000alocalized, transient sites where hydromagnetic instabilities, shocks, and\\/or\\u000aturbulence lead to magnetic mirroring along current-carrying flux tubes. The\\u000amaser is pumped as electrons are accelerated by the parallel electric field\\u000athat

  20. Cyclotron Maser Emission from Blazar Jets?

    Microsoft Academic Search

    Mitchell C. Begelman; Robert E. Ergun; Martin J. Rees

    2005-01-01

    We consider the production of electron cyclotron maser emission by low-density, highly magnetized plasmas in relativistic jets. The population inversion required to drive cyclotron maser instability could occur in localized, transient sites where hydromagnetic instabilities, shocks, and\\/or turbulence lead to magnetic mirroring along current-carrying flux tubes. The maser is pumped by the conversion of kinetic and magnetic energy into j

  1. Building 211 cyclotron characterization survey report

    SciTech Connect

    NONE

    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.

  2. Production of superthermal electrons and ion cyclotron waves in a reversed-field-pinch plasma

    SciTech Connect

    Yoshida, Z. (Department of Nuclear Engineering, University of Tokyo, Hongo, Tokyo 113 (Japan)); Hasegawa, A. (Department of Communication Engineering, Osaka University, Suita, Osaka 565 (Japan)); Wakatani, M. (Plasma Physics Laboratory, Kyoto University, Gokasho, Uji 611 (Japan))

    1993-09-01

    Production of superthermal electrons through kinetic interactions with electromagnetic fluctuations is studied to account for observations of fast electrons and ion cyclotron waves in reversed field pinch plasmas. Low-frequency Alfvenic (torsional) modes can interact with electrons through the Landau resonance when the wavelength perpendicular to the magnetic field is as small as the ion gyroradius. Such kinetic Alfven waves induce simultaneous diffusion (double diffusion) in the coordinate and velocity spaces, and produce a field aligned superthermal electron beam in the edge region. Microinstabilities are driven by the electron-beam and ion cyclotron waves are excited. Through these precesses the fluctuation energy in the low-frequency regime may be transported to the ion cyclotron frequency regime.

  3. On the electrically detected cyclotron resonance of holes in silicon nanostructures

    SciTech Connect

    Bagraev, N. T., E-mail: bagraev@mail.ioffe.ru; Gets, D. S.; Danilovsky, E. Yu.; Klyachkin, L. E.; Malyarenko, A. M. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2013-04-15

    The cyclotron resonance in semiconductor nanostructures is electrically detected for the first time without an external cavity, a source, and a detector of microwave radiation. An ultranarrow p-Si quantum well on an n-Si (100) surface confined by superconducting heavily boron-doped {delta}-shaped barriers is used as the object of investigation and provides microwave generation within the framework of the nonstationary Josephson effect. The cyclotron resonance is detected upon the presence of a microcavity, which is incorporated into the quantum-well plane, by measuring the longitudinal magnetoresistance under conditions of stabilization of the source-drain current. The cyclotron-resonance spectra and their angular dependences measured in a low magnetic field identify small values of the effective mass of light and heavy holes in various 2D subbands due to the presence of edge channels with a high mobility of carriers.

  4. Note: Control of liquid helium supply to cryopanels of Kolkata superconducting cyclotron.

    PubMed

    Bhattacharyya, T K; Pal, G

    2015-02-01

    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. PMID:25725894

  5. Note: Control of liquid helium supply to cryopanels of Kolkata superconducting cyclotron

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, T. K.; Pal, G.

    2015-02-01

    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.

  6. Conceptual design of the RF accelerating cavities for a superconducting cyclotron

    Microsoft Academic Search

    M. Maggiore; L. Calabretta; M. Di Giacomo; D. Rifuggiato; D. Battaglia; L. Piazza

    2006-01-01

    A superconducting cyclotron accelerating ions up to 250AMeV, for medical applications and radioactive ions production is being studied at Laboratori Nazionali del Sud in Catania. The radio frequency (RF) system, working in the fourth harmonic, is based on four normal conducting radio frequency cavities operating at 93MHz. This paper describes an unusual multi-stem cavity design, performed with 3D electromagnetic codes.

  7. General Electric PETtrace cyclotron as a neutron source for boron neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Bosko, Andrey

    This research investigates the use of a PETtrace cyclotron produced by General Electric (GE) as a neutron source for boron neutron capture therapy (BNCT). The GE PETtrace was chosen for this investigation because this type of cyclotron is popular among nuclear pharmacies and clinics in many countries; it is compact and reliable; it produces protons with energies high enough to produce neutrons with appropriate energy and fluence rate for BNCT and it does not require significant changes in design to provide neutrons. In particular, the standard PETtrace 18O target is considered. The cyclotron efficiency may be significantly increased if unused neutrons produced during radioisotopes production could be utilized for other medical modalities such as BNCT at the same time. The resulting dose from the radiation emitted from the target is evaluated using the Monte Carlo radiation transport code MCNP at several depths in a brain phantom for different scattering geometries. Four different moderating materials of various thicknesses were considered: light water, carbon, heavy water, arid Fluental(TM). The fluence rate tally was used to calculate photon and neutron dose, by applying fluence rate-to-dose conversion factors. Fifteen different geometries were considered and a 30-cm thick heavy water moderator was chosen as the most suitable for BNCT with the GE PETtrace cyclotron. According to the Brookhaven Medical Research Reactor (BMRR) protocol, the maximum dose to the normal brain is set to 12.5 RBEGy, which for the conditions of using a heavy water moderator, assuming a 60 muA beam current, would be reached with a treatment time of 258 min. Results showed that using a PETtrace cyclotron in this configuration provides a therapeutic ratio of about 2.4 for depths up to 4 cm inside a brain phantom. Further increase of beam current proposed by GE should significantly improve the beam quality or the treatment time and allow treating tumors at greater depths.

  8. Compact superconducting 250 MeV proton cyclotron for the PSI PROSCAN proton therapy project

    NASA Astrophysics Data System (ADS)

    Schillo, M.; Geisler, A.; Hobl, A.; Klein, H. U.; Krischel, D.; Meyer-Reumers, M.; Piel, C.; Blosser, H.; Kim, J.-W.; Marti, F.; Vincent, J.; Brandenburg, S.; Beijers, J. P. M.

    2001-12-01

    A cyclotron for proton therapy has to fulfill many requirements set by the specific operational and safety needs of a medical facility and the medical environment. These are for instance high extraction efficiency, high availability and reliability, simple and robust operation. ACCEL Instruments GmbH has refined the design concept of a medical cyclotron for the PSI PROSCAN project with the objective to use this cyclotron as the standard accelerator in complete proton therapy facilities, which ACCEL intends to market. Starting from the design in [1], we have carried out further detail clarifications, optimizations and adaptations to the needs of PSI [2]. The work was performed in a collaboration between ACCEL, NSCL and KVI in view of the requirements from the PSI PROSCAN project. An overview on the design will be given touching on subjects such as the 3D structural analysis of the coil, detailed magnetic modeling for optimization of the inner region and the spiral, optimization of the RF power, optimization of the cryogenic design based on available cryocoolers instead of a liquefaction plant and Monte Carlo simulations to estimate the heat balance produced by neutrons at 4K components.

  9. Vacuum System of the Large Cyclotrons at VECC

    NASA Astrophysics Data System (ADS)

    Pal, G.; Mallik, C.; Yadav, R. C.; Akhter, J.; Datta Gupta, A.; Mandal, B.; Roy, A.; Polley, A.; Datta, M.; Nandi, C.; Sarkar, A.; Bhattacharyya, Srimantra; Pal, Sarbajit; Bhandari, R. K.

    2012-11-01

    Variable Energy Cyclotron Centre (VECC) has two large cyclotrons, K-130 cyclotron and K-500 cyclotron. The first beam in the room temperature K-130 cyclotron (RTC) was accelerated in June 1977. The cyclotron accelerated and delivered alpha and proton beams consistently to the cyclotron users for several years. Heavy ion beams were available in this cyclotron from 1997 to 2007. Presently, the cyclotron is working as a primary source for RIB production. The cyclotron has an acceleration chamber volume of about 28 m3. The total length of beam line is about 65 m. Vacuum of the order of 1 x 10-6 mbar is presently maintained in the cyclotron and beam line using diffusion pumps. It is one of the largest vacuum systems operating in India. It is consistently being operated 24 x 7 round the year giving beam to the cyclotron users. A K-500 superconducting cyclotron (SCC) with K=520 has been constructed at Kolkata. SCC will be used to accelerate beams to 80 MeV/A for light heavy ions and about 10 MeV/A for medium mass heavy ions. Three turbo molecular pumps are connected to the acceleration chamber. Three cryopanels placed inside the lower dees in the valley gap of the superconducting magnet are available in the accelerating chamber for achieving high vacuum. The acceleration chamber having a volume of about 1.0 m3 was operated using turbomolecular pumps, liquid nitrogen cooled panels and liquid helium cooled cryopanels at different stages during beam commissioning. Differential pumping is provided across the RF liner to avoid distortion. The first beam line of about 21 m has been installed in the cyclotron. The outer vacuum chamber of the cyclotron magnet cryostat has active pumping. The vacuum system of the superconducting cyclotron is also operating reliably round the clock throughout the year. The paper describes the details of the vacuum systems of the large cyclotrons at VEC Centre Kolkata India, its commissioning and operating experience.

  10. Stereotactic Body Radiotherapy Versus Surgery for Medically Operable Stage I Non-Small-Cell Lung Cancer: A Markov Model-Based Decision Analysis

    SciTech Connect

    Louie, Alexander V. [Department of Oncology, University of Western Ontario, London, ON (Canada); Rodrigues, George, E-mail: george.rodrigues@lhsc.on.ca [Department of Oncology, University of Western Ontario, London, ON (Canada); Department of Epidemiology/Biostatistics, University of Western Ontario, London, ON (Canada); Hannouf, Malek [Department of Epidemiology/Biostatistics, University of Western Ontario, London, ON (Canada); Zaric, Gregory S. [Department of Epidemiology/Biostatistics, University of Western Ontario, London, ON (Canada); Richard Ivey School of Business, University of Western Ontario, London, ON (Canada); Palma, David A. [Department of Oncology, University of Western Ontario, London, ON (Canada); Cao, Jeffrey Q. [Department of Oncology, University of Western Ontario, London, ON (Canada); Richard Ivey School of Business, University of Western Ontario, London, ON (Canada); Yaremko, Brian P. [Department of Oncology, University of Western Ontario, London, ON (Canada); Malthaner, Richard [Department of Epidemiology/Biostatistics, University of Western Ontario, London, ON (Canada); Division of Surgery, University of Western Ontario, London, ON (Canada); Mocanu, Joseph D. [Richard Ivey School of Business, University of Western Ontario, London, ON (Canada)

    2011-11-15

    Purpose: To compare the quality-adjusted life expectancy and overall survival in patients with Stage I non-small-cell lung cancer (NSCLC) treated with either stereotactic body radiation therapy (SBRT) or surgery. Methods and Materials: We constructed a Markov model to describe health states after either SBRT or lobectomy for Stage I NSCLC for a 5-year time frame. We report various treatment strategy survival outcomes stratified by age, sex, and pack-year history of smoking, and compared these with an external outcome prediction tool (Adjuvant{exclamation_point} Online). Results: Overall survival, cancer-specific survival, and other causes of death as predicted by our model correlated closely with those predicted by the external prediction tool. Overall survival at 5 years as predicted by baseline analysis of our model is in favor of surgery, with a benefit ranging from 2.2% to 3.0% for all cohorts. Mean quality-adjusted life expectancy ranged from 3.28 to 3.78 years after surgery and from 3.35 to 3.87 years for SBRT. The utility threshold for preferring SBRT over surgery was 0.90. Outcomes were sensitive to quality of life, the proportion of local and regional recurrences treated with standard vs. palliative treatments, and the surgery- and SBRT-related mortalities. Conclusions: The role of SBRT in the medically operable patient is yet to be defined. Our model indicates that SBRT may offer comparable overall survival and quality-adjusted life expectancy as compared with surgical resection. Well-powered prospective studies comparing surgery vs. SBRT in early-stage lung cancer are warranted to further investigate the relative survival, quality of life, and cost characteristics of both treatment paradigms.

  11. High Radiation Dose May Reduce the Negative Effect of Large Gross Tumor Volume in Patients With Medically Inoperable Early-Stage Non-Small Cell Lung Cancer

    SciTech Connect

    Zhao Lujun [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI (United States); West, Brady T. [Center for Statistical Consultation and Research, University of Michigan Medical Center, Ann Arbor, MI (United States); Hayman, James A. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI (United States); Lyons, Susan [Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI (United States); Department of Radiation Oncology, Veterans Administration Health Center, Ann Arbor, MI (United States); Cease, Kemp [Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI (United States); Department of Radiation Oncology, Veterans Administration Health Center, Ann Arbor, MI (United States); Kong, F.-M. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI (United States) and Department of Radiation Oncology, Veterans Administration Health Center, Ann Arbor, MI (United States)]. E-mail: Fengkong@med.umich.edu

    2007-05-01

    Purpose: To determine whether the effect of radiation dose varies with gross tumor volume (GTV) in patients with stage I/II non-small cell lung cancer (NSCLC). Methods and Materials: Included in the study were 114 consecutive patients with medically inoperable stage I/II NSCLC treated with three-dimensional conformal radiotherapy between 1992 and 2004. The median biologic equivalent dose (BED) was 79.2 Gy (range, 58.2-124.5 Gy). The median GTV was 51.8 cm{sup 3} (range, 2.1-727.8 cm{sup 3}). The primary endpoint was overall survival (OS). Kaplan-Meier estimation and Cox regression models were used for survival analyses. Results: Multivariate analysis showed that there was a significant interaction between radiation dose and GTV (p < 0.001). In patients with BED {<=}79.2 Gy (n = 68), the OS medians for patients with GTV >51.8 cm{sup 3} and {<=}51.8 cm{sup 3} were 18.2 and 23.9 months, respectively (p 0.015). If BED was >79.2 Gy (n = 46), no significant difference was found between GTV groups (p = 0.681). For patients with GTV >51.8 cm{sup 3} (n = 45), the OS medians in those with BED >79.2 Gy and {<=}79.2 Gy were 30.4 and 18.2 months, respectively (p < 0.001). If GTV was {<=}51.8 cm{sup 3} (n = 45), the difference was no longer significant (p = 0.577). Conclusion: High-dose radiation is more important for patients with larger tumors and may be effective in reducing the adverse outcome associated with large GTV. Further prospective studies are needed to confirm this finding.

  12. Numerical investigation for high intensity H- beam injection to a 100 MeV compact cyclotron

    NASA Astrophysics Data System (ADS)

    Zhang, Tianjue; Yao, Hongjuan; Guan, Xialing; Chu, Chengjie; Zhong, Junqing; Yin, Zhiguo

    2004-05-01

    As a part of the Upgrade Project of Beijing Tandem Accelerator Laboratory, a 100 MeV compact cyclotron was designed for the generation of high intensity proton beam. In comparison the H- beam intensity injected into the cyclotron central region of the 30 MeV medical cyclotron developed at CIAE 8 years ago, those injected into the 100 MeV machine will be 4 times higher. So, the axial injection optics was investigated numerically again by means of taking the space charge effect into account. The simulation started from the old layout based on the ES (Einzell lens and solenoid) system in CIAE's 30 MeV machine and SQQ system (solenoid and doublet) in TRIUMF's machine, shows that a ESQQ system should be able to match the injection optics better for higher intensity beam injection. A new layout based on ESQQ injection system will be used for the 100 MeV cyclotron. From three-dimensional field computation, the modularization of magnets (S and QQ) are designed so that the injection line ESQQ could be rearranged flexibly.

  13. 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.

  14. National Superconducting Cyclotron Laboratory Call for Proposals--PAC 37

    E-print Network

    Liu, Taosheng

    National Superconducting Cyclotron Laboratory Call for Proposals--PAC 37 February 2, 2012 Dear NSCL. apparatus (including drawing); 2. Status of previous experiments completed at the Coupled Cyclotron Facility

  15. COUPLED HELICON-CYCLOTRON MODES: THEORY AND EXPERIMENT

    E-print Network

    Chen, Francis F.

    COUPLED HELICON-CYCLOTRON MODES: THEORY AND EXPERIMENT Francis F. Chen, Donald Arnush, John D to the usual helicon (H) wave by the boundary condition. The TG mode is an electron cyclotron wave in a bounded

  16. Interpretive Experiments: An Interpretive Experiment in Ion Cyclotron Resonance Spectroscopy.

    ERIC Educational Resources Information Center

    Burnier, R. C.; Freiser, B. S.

    1979-01-01

    Provides a discussion which is intended for chemistry college students on the ion cyclotron resonance (ICR) spectroscopy, the physical basis for ion cyclotron resonance, and the experimental methodology employed by ICR spectroscopists. (HM)

  17. Special radiation protection aspects of medical accelerators.

    PubMed

    Silari, M

    2001-01-01

    Radiation protection aspects relevant to medical accelerators are discussed. An overview is first given of general safety requirements. Next, shielding and labyrinth design are discussed in some detail for the various types of accelerators, devoting more attention to hadron machines as they are far less conventional than electron linear accelerators. Some specific aspects related to patient protection are also addressed. Finally, induced radioactivity in accelerator components and shielding walls is briefly discussed. Three classes of machines are considered: (1) medical electron linacs for 'conventional' radiation therapy, (2) low energy cyclotrons for production of radionuclides mainly for medical diagnostics and (3) medium energy cyclotrons and synchrotrons for advanced radiation therapy with protons or light ion beams (hadron therapy). PMID:11843087

  18. Phase space characterization of an internal ion source for cyclotrons

    Microsoft Academic Search

    Edward Russell Forringer

    2004-01-01

    Orbit tracking codes are used to predict the behavior of the beam in a cyclotron before the cyclotron is constructed by tracking many orbits which collectively are intended to represent the beam. Cyclotrons with internal ion sources (such as the series of 250 MeV proton beam cancer therapy cyclotrons being manufactured by ACCEL Instruments GmbH of Bergisch-Gladbach Germany) present difficulty

  19. Design and testing of an electron cyclotron resonance heating ion source for use in high field compact superconducting cyclotrons

    E-print Network

    Artz, Mark E

    2012-01-01

    The main goal of this project is to evaluate the feasibility of axial injection of a high brightness beam from an Electron Cyclotron Resonance ion source into a high magnetic field cyclotron. Axial injection from an ion ...

  20. 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.

  1. Relativistic Dispersion, the Cyclotron Maser Instability, and Auroral Kilometric Radiation

    Microsoft Academic Search

    P. L. Pritchett

    1984-01-01

    The most successful explanation proposed for the generation of auroral kilometric radiation (AKR) is the direct cyclotron mechanism in which radiation excited near the local electron cyclotron frequency is amplified through a gyroresonant interaction. Previous work has shown that inclusion of the relativistic mass dependence of the cyclotron frequency is essential to determine the resonant contours in velocity space. In

  2. Autoresonant ion cyclotron isotope separation and J. Robiche

    E-print Network

    Autoresonant ion cyclotron isotope separation J.-M. Raxa and J. Robiche Laboratoire de Physique et separation process based on selective cyclotron resonant interaction between ions and a tapered helicoidal a separation criterion. This autoresonant ion cyclotron isotope separation mechanism provides an efficient

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

    E-print Network

    Santolik, Ondrej

    Ion cyclotron harmonics in the Saturn downward current auroral region J. D. Menietti,1 P. Schippers Investigation (CAPS) instrument we have been able to identify ion cyclotron harmonic waves associated. Gurnett, F. Crary, and A. J. Coates (2011), Ion cyclotron harmonics in the Saturn downward current auroral

  4. Cyclotron Resonances in a Non-Neutral Multispecies Ion Plasma

    E-print Network

    California at San Diego, University of

    Cyclotron Resonances in a Non-Neutral Multispecies Ion Plasma M. Affolter, F. Anderegg, C. F, California 92093 Abstract. Shifts of the cyclotron mode frequencies, away from the single particle limit as determination of cyclotron mode frequencies from launched wave absorption. At moderately low temperatures, the m

  5. ccsd00001954, Electron cyclotron current drive eciency in an

    E-print Network

    ccsd­00001954, version 1 ­ 22 Oct 2004 Electron cyclotron current drive e�ciency in an axisymmetric@nuclear.inin.mx Abstract. The neoclassical transport theory is applied to calculate electron cyclotron current drive (ECCD cyclotron resonant surface at a speci#12;c poloidal location. The ECCD e�ciency is analyzed in the cases

  6. Search for Cyclotron Maser Emission from Extrasolar Planets

    E-print Network

    Richardson Jr., James E.

    Chapter 3 Search for Cyclotron Maser Emission from Extrasolar Planets 3.1 Introduction Radio frequency cyclotron maser radiation is emitted by all five of our solar sys- tem's magnetized planets, the "Radiometric Bode's Law" and a variation on that law by Zarka, we predicted radio fluxes and cyclotron

  7. Inverse ion-cyclotron damping: Laboratory demonstration and space ramificationsa...

    E-print Network

    California at Berkeley, University of

    Inverse ion-cyclotron damping: Laboratory demonstration and space ramificationsa... M. E. Koepke 2003 The familiar and ubiquitous phenomenon of ion-cyclotron damping is shown to be invertible in a laboratory plasma resembling ionospheric plasma in terms of important dimensionless parameters. The ion-cyclotron

  8. LE JOURNAL DE PHYSIQUE DISPOSITIF DE SYNCHRONISATION AUTOMATIQUE DU CYCLOTRON

    E-print Network

    Boyer, Edmond

    LE JOURNAL DE PHYSIQUE ET LE RADIUM DISPOSITIF DE SYNCHRONISATION AUTOMATIQUE DU CYCLOTRON Par PIERRE DEBRAINE. Ingénieur E. P. C. I., Chef du Groupe du Cyclotron au C. E. A. et 010CESTMÍR 0160ÍMÁN011 réalisation d'un dispositif de synchronisation du cyclotron, permettant de faire fonctionner cet appareil avec

  9. RXTE Studies of Cyclotron Lines in Accreting Pulsars

    E-print Network

    Barnstedt, Jürgen

    RXTE Studies of Cyclotron Lines in Accreting Pulsars W.A. Heindl \\Lambda , W. Coburn \\Lambda , D, 1290 Versoix, Switzerland I INTRODUCTION Cyclotron lines in accreting X­ray pulsar spectra result from near the neutron star poles. For this reason they are known as cyclotron resonance scattering features

  10. Electron Cyclotron Emission Radiometer Cristina Morales, Advisor: Dr. John Rodgers,

    E-print Network

    Anlage, Steven

    Electron Cyclotron Emission Radiometer Cristina Morales, Advisor: Dr. John Rodgers, Abstract ·The-Maxwellian bursts in plasma temperature. ·The receiver measures electron cyclotron emission (ECE) from magnetized around the magnetic field lines and radiate at the electron cyclotron frequency given by ·Magnetic Field

  11. ccsd00001798, Polarization Reversal of Electron Cyclotron Wave

    E-print Network

    ccsd­00001798, version 1 ­ 20 Oct 2004 Polarization Reversal of Electron Cyclotron Wave Due waves with electron cyclotron resonance (ECR) frequency are experimentally and theoretically. Introduction Electron cyclotron wave is important plasma waves in the #12;elds of basic plasma physics, nuclear

  12. Nonlinear Cyclotron-Resonance Accelerations by a Generalized EM Wave

    E-print Network

    Boyer, Edmond

    Nonlinear Cyclotron-Resonance Accelerations by a Generalized EM Wave AKIMOTO, Kazuhiro and HOJO that the well-known cyclotron resonance may be classified into three regimes as the length and/or the amplitude of the pulse are varied. Namely, as the pulse amplitude increases, the transit-time cyclotron

  13. VARIABLE CYCLOTRON LINE IN HER X-1 R. Staubert1

    E-print Network

    Barnstedt, Jürgen

    VARIABLE CYCLOTRON LINE IN HER X-1 R. Staubert1 , N. I. Shakura2 , K. P. Postnov2 , J. Wilms3 , W of California, San Diego, USA ABSTRACT We present new results on the cyclotron resonance scat- tering feature that the cyclotron line energy correlates with the observed maximum flux of the corresponding 35 day Main-On state

  14. ELECTRON CYCLOTRON HEATING OF AN ANISOTROPIC PLASMA J. C. SPROTT

    E-print Network

    Sprott, Julien Clinton

    ELECTRON CYCLOTRON HEATING OF AN ANISOTROPIC PLASMA by J. C. SPROTT December 4, 1969 PLP No. 322 professor. Plasma Studies University of Wisconsin #12;Electron Cyclotron Heating of an Anisotropic Plasma, and multipole confined plasmas also exhibit a degree of anisotropy at high energies when electron cyclotron 1

  15. Electron Cyclotron Heating in a Non-Uniform Magnetic Field

    E-print Network

    Sprott, Julien Clinton

    Electron Cyclotron Heating in a Non-Uniform Magnetic Field by J.e. Sprott December 1968 Presented pulse. IN1RODUCTION Most previous theories of electron cyclotron resonance heating have dealt primarily will outline a simple theoretical model which can be used to estimate the electron cyclotron heating rate

  16. COLLISIONAL CYCLOTRON HEATING NEAR THE OCTUPOLE B = 0 AXIS

    E-print Network

    Sprott, Julien Clinton

    COLLISIONAL CYCLOTRON HEATING NEAR THE OCTUPOLE B = 0 AXIS by J. C. Sprott March 1974 PLP 551 reports the results of (electron or ion) cyclotron heating calculations near the B 0 axis in an octupo1e, the resonance surface is a large aspect ratio toroid of minor radius r , and the cyclotron frequency varies as o

  17. Transmission characteristics of cyclotron harmonic waves in plasma

    Microsoft Academic Search

    F. W. Crawford; H. H. Weiss

    1966-01-01

    In recent years the importance of cyclotron harmonic waves has become apparent in many branches of plasma physics. For example, it has been demonstrated that they are involved in the anomalously high noise radiation near the electron cyclotron harmonic frequencies that has been observed from thermonuclear fusion study devices, and that they can explain the cyclotron harmonic resonances observed in

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

    PubMed

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

    2014-02-01

    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. PMID:24593512

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    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.

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

    SciTech Connect

    Efremov, A., E-mail: efremov@nrmail.jinr.ru; Bogomolov, S.; Lebedev, A.; Loginov, V.; Yazvitsky, N. [Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions, Dubna, Moscow Reg. 141980 (Russian Federation)] [Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions, Dubna, Moscow Reg. 141980 (Russian Federation)

    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.

  1. Biological and medical application of SR from the storage rings of VEPP-3 and “Siberia2”. The origin of specific changes of small-angle X-ray diffraction pattern of hair and their correlation with the elemental content

    Microsoft Academic Search

    A. M Aksirov; V. S Gerasimov; V. I Kondratyev; V. N Korneev; G. N Kulipanov; N. F Lanina; V. P Letyagin; N. A Mezentsev; P. M Sergienko; B. P Tolochko; V. A Trounova; A. A Vazina

    2001-01-01

    X-ray diffraction and fluorescent investigations of human hair were carried out using SR of VEPP-3. The small-angle techniques were used for ecological monitoring and medical diagnostics of pathological states of human organisms with the usage of non-invasive methods for express analysis of biological objects, including human and animal tissues: nails, wool and hair samples.Possibility using of hair fibre diffraction to

  2. Comparison of outcomes for patients with medically inoperable Stage I non-small-cell lung cancer treated with two-dimensional vs. three-dimensional radiotherapy

    SciTech Connect

    Fang, L. Christine [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Komaki, Ritsuko [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)]. E-mail: rkomaki@mdanderson.org; Allen, Pamela [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Guerrero, Thomas [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Mohan, Radhe [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Cox, James D. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

    2006-09-01

    Purpose: This retrospective analysis was performed to assess the outcomes of three-dimensional (3D) conformal radiotherapy and two-dimensional (2D) planning. Methods and Materials: Between 1978 and 2003, 200 patients with Stage I non-small-cell lung cancer (NSCLC) were treated with radiotherapy alone at M.D. Anderson Cancer Center. Eighty-five patients were treated with 3D conformal radiotherapy. For the 3D group, median age, radiation dose, and follow-up was 73 (range, 50-92), 66 Gy (range, 45-90.3 Gy), and 19 months (range, 3-77 months), respectively; and for the 2D group, 69 (range, 44-88), 64 Gy (range, 20-74 Gy), 20 months (range, 1-173 months), respectively. Overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), locoregional control (LRC), and distant metastasis-free survival (DMFS) rates were analyzed. Results: There was no statistically significant difference in patient and tumor characteristics between 2D and 3D groups, except the 3D patients were older (p = 0.006). The OS, DSS, and LRC rates were significantly higher in patients who were treated by 3D conformal radiotherapy. Two- and 5-year OS for the 3D group were 68% and 36%, respectively, and 47% and 10% in the 2D group (p = 0.001). DSS at 2 and 5 years for the 3D group were 83% and 68%, respectively, vs. 62% and 29% in the 2D group (p < 0.001). LRC rates at 2 and 5 years for patients in the 3D group were 77% and 70% and 53% and 34% in the 2D group (p < 0.001). On univariate analysis elective, nodal irradiation was associated with decreased OS, DSS, and LRC. On multivariate analysis, 3D conformal radiotherapy was associated with increased OS and DSS. Male sex, age {>=}70, weight loss {>=}5%, and tumor size {>=}4 cm were associated with decreased OS and DSS. Conclusions: This study demonstrates that 3D conformal radiotherapy improves outcomes in patients with medically inoperable Stage I NSCLC compared with 2D treatment and is an acceptable treatment for this group of patients.

  3. Indiana University cyclotron facility Back by popular demand are guided tours of the IU cyclotron facility, a

    E-print Network

    Evans, Hal

    Open House at the Indiana University cyclotron facility Back by popular demand are guided tours of the IU cyclotron facility, a large, multi-disciplinary laboratory where research in nuclear physics of Energy and Matter, and IU Cyclotron Operations, which supports the Midwest Proton Radiotherapy Institute

  4. Distinction between electrostatic ion cyclotron waves and ion cyclotron harmonic waves

    Microsoft Academic Search

    P. M. Kintner

    1980-01-01

    Two distinctly different plasma wave modes with structure related to the ion cyclotron frequency, ..omega..\\/sub ci\\/, have been detected by instruments onboard the S3-3 satellite. The harmonic frequency structure with respect to ..omega..\\/sub ci\\/ is different for each mode and the two modes exhibit different values of phase coherence. One referred to as the electrostatic ion cyclotron wave has already

  5. Development of an Accelerator Mass Spectrometer based on a Cyclotron

    SciTech Connect

    Kim, Dogyun; Bhang, Hyeongchan [Department of Physics and Astronomy, Seoul National University, Seoul, 151-742 (Korea, Republic of); Kim, Jongwon [Department of Biomedical Engineering, National Cancer Center, Goyang, Gyeonggi, 410-769 (Korea, Republic of)

    2011-12-13

    An accelerator mass spectrometer based on a cyclotron has been developed, and a prototype of the injection beam line has been constructed. Mass resolution of the cyclotron is designed to be over 4000. A sawtooth RF buncher in the beam line and a flat-topping RF system for the cyclotron were utilized to enhance beam transmission efficiency, which is a primary factor for improvement compared to previous cyclotron mass spectrometers. The injection beam line comprises an ion source, Einzel lens, RF buncher, 90 deg. dipole magnet and a slit box containing beam diagnostic devices. A carbon beam was measured at the location of the slit box, and beam phase spaces will be measured. The design of a cyclotron magnet was done, and orbit tracking was carried out using cyclotron optics codes. A scheme of radial injection was chosen to place a beam on the equilibrium orbit of the cyclotron. The injection scheme will be optimized after the beam measurements are completed.

  6. Cyclotron radiation and emission in graphene

    NASA Astrophysics Data System (ADS)

    Morimoto, Takahiro; Hatsugai, Yasuhiro; Aoki, Hideo

    2008-08-01

    Peculiarity in the cyclotron radiation and emission in graphene is theoretically examined in terms of the optical conductivity and relaxation rates to propose that graphene in magnetic fields can be a candidate for realizing the Landau-level laser, proposed decades ago [H. Aoki, Appl. Phys. Lett. 48, 559 (1986)].

  7. Electron cyclotron resonance charge breeder (invited)

    Microsoft Academic Search

    P. Sortais; J. F. Bruandet; J. L. Bouly; N. Chauvin; J. C. Curdy; R. Geller; T. Lamy; P. Sole; J. L. Vieux-Rochaz

    2000-01-01

    Initially developed for radioactive ion beam production, the electron cyclotron resource (ECR) charge breeder shows that the beam injection of a primary beam inside an ECR ion source is a very general process for beam production. In this article we will review the latest results obtained on the ISN Grenoble test bench for the production of clockwise (CW) or pulsed

  8. Ion cyclotron heating of a plasma

    Microsoft Academic Search

    T H Stix

    1961-01-01

    Experiments with ion cyclotron heating of a deuterium plasma confined in the B-65 stellarator are reported. Single-particle type behaviour is evidenced by the production of neutrons, ascribed to deuterons accelerated in the low density region beneath the induction coil but at the outside of the plasma, at a value B0 of confining magnetic field corresponding to single particle resonance. Ion

  9. The TRIUMF facility and cyclotron developments

    Microsoft Academic Search

    R. Baartman; P. Bricault; M. Dombsky; G. Dutto; K. Fong; T. Kuo; R. E. Laxdal; A. Mitra; R. Ruegg; G. H. Mackenzie; M. Olivo; R. Poirier; K. Reiniger; L. Root; P. W. Schmor; M. Stenning; G. Stinson

    2001-01-01

    The TRIUMF cyclotron has delivered, over the past several years, simultaneous proton beams to meson users, proton users, and low energy proton users with total intensity around 200 ?A at energies between 60 and 500 MeV Since 1998 it has also been delivering routinely 500 MeV protons to ISAC with proton currents up to 40 ?A on target. Initial ISAC

  10. The Superconducting Ring Cyclotron in RIKEN

    Microsoft Academic Search

    H. Okuno; J. Ohnishi; K. Yamada; N. Fukunishi; K. Ikegami; T. Maie; H. Hasebe; M. Hamanaka; M. Kase; A. Goto; Y. Yano

    2007-01-01

    RIKEN Nishina Center for accelerator-based science in RIKEN is constructing the radioactive isotope beam factory (RIBF), which is capable of providing the world's most intense RI beams over the whole range of atomic masses. 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

  11. Characterization of electron cyclotron resonance hydrogen plasmas

    Microsoft Academic Search

    C. A. Outten; J. C. Barbour; W. R. Wampler

    1991-01-01

    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 ({ital V}{sub {ital p}} ), electron density ({ital N}{sub {ital e}} ), electron

  12. Neutron radiography using a transportable superconducting cyclotron

    Microsoft Academic Search

    D. A. Allen; M. R. Hawkesworth; T. D. Beynon; S. Green; J. D. Rogers; M. J. Allen; H. C. Plummer; N. J. Boulding; M. Cox; I. McDougall

    1994-01-01

    A thermal neutron radiography system based on a compact 12 MeV superconducting proton cyclotron is described. Neutrons are generated using a thick beryllium target and moderated in high density polyethylene. Monte Carlo computer simulations have been used to model the neutron and photon transport in order to optimise the performance of the system. With proton beam currents in excess of

  13. Comparison between californium and cyclotron SEU tests

    NASA Astrophysics Data System (ADS)

    Velazco, Raoul; Provost-Grellier, Antoine; Chapuis, T.; Labrunee, M.; Falguere, D.; Koga, R.

    Experimental equipment which performs heavy ion testing for programmable integrated circuits is presented. This equipment is used along with two different means of heavy ion simulator to perform Single Event Upset (SEU) tests on representative circuits: a dedicated Cf 252 fission decay source to simulate high LET particles is questioned by the discrepancies observed between Cf 252 and cyclotron results.

  14. Cyclotron-based neutron source for BNCT

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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 & 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 1.8×109 neutrons/cm2/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 10B-p-Borono-phenylalanine. Clinical trials of malignant brain tumors will be started in this year.

  15. Cyclotron-based neutron source for BNCT

    SciTech Connect

    Mitsumoto, T.; Yajima, S.; Tsutsui, H.; Ogasawara, T.; Fujita, K. [Sumitomo Heavy Industries, Ltd (Japan); Tanaka, H.; Sakurai, Y.; Maruhashi, A. [Kyoto University Research Reactor Institute (Japan)

    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.

  16. Stability of the electron cyclotron resonance

    E-print Network

    Joachim Asch; Olivier Bourget; Cédric Meresse

    2014-12-30

    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.

  17. Medical Practice Makes Perfect

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Cedaron Medical Inc., was founded in 1990 as a result of a NASA SBIR (Small Business Innovative Research) grant from Johnson Space Center to develop a Hand Testing and Exercise Unit for use in space. From that research came Dexter, a comprehensive workstation that creates a paperless environment for medical data management.

  18. Medical volume image summarization

    Microsoft Academic Search

    Feng Ding; Hao Li; Yuan Cheng; W. K. Leow

    2009-01-01

    Medical volume images are large in size. They cannot be efficiently transmitted and visualized as candidates for medical image retrieval and relevance feedback. On the other hand, 2D images that are small in size and rich in 3D details can be efficiently transmitted and visualized as candidates. This paper presents an algorithm that summarizes the 3D details in a volume

  19. Space Charge Frequency Shifts of the Cyclotron Modes in Multi-Species Ion Plasmas

    NASA Astrophysics Data System (ADS)

    Affolter, M.; Anderegg, F.; Driscoll, C. F.

    2015-02-01

    Shifts of the cyclotron frequency away from the "bare" cyclotron frequency are observed to be proportional to the total ion density through the E × B rotation frequency, and to the relative concentration of each ion species, in quantitative agreement with analytic theory. These shifts are measured at small excitation amplitudes on the typical center-of-mass m = 1 mode, and also on cyclotron modes with m = 0 and m = 2 azimuthal dependence. The frequency spacing between these modes is proportional to the rotation frequency of the ion cloud, which is controlled and measured using a "rotating wall" and laser-induced fluorescence. These cylindrical ion plasmas consist of Mg+ isotopes, with H3 O + and O2 + impurities. It is observed that the shift in the m = 1 cyclotron frequency is larger for the minority species 25Mg+ and 26Mg+, than for the majority species 24Mg+. A simple center-of-mass model is presented, which is in quantitative agreement with these results. It is also shown that this model interprets and expands the intensity dependent calibration equation, ( M/ q) = A/ f + B/ f 2 + CI/ f 2.

  20. Design study of a 9 MeV compact cyclotron system for PET

    NASA Astrophysics Data System (ADS)

    Lee, Byeong-No; Shin, Seung-Wook; Song, Hoseung; Kim, Hyun-Wook; Chai, Jong-Seo

    2013-06-01

    A cyclotron is an accelerator which can be applied to both cancer diagnosis and treatment. Among commercially sold cyclotrons, the major energy is used for positron emission tomography (PET) ranges from 10 to 20 MeV. In this research, 9 MeV compact cyclotron for PET was designed. The research was conducted on the response cross section and the yield for the energy distribution to decide the design features. Also, it was determined the specifications on the basis of the fluoro-deoxy-glucose (FDG) maximum dose. The machine, which has a 20 uA beam current, is designed to be installed in small-to-medium-sized hospitals in local cities because of its relatively light weight (6 tons). This compact cyclotron, which provides 9-MeV proton beams, is composed of a azimuthally varying field (AVF) electromagnet, 83-MHz RF systems with a 20 kW amplifier, a panning ion gauge (PIG) type ion-source for negative hydrogen, and a double-stage high-vacuum system. The basic model design was done by using 3-D CAD program, CATIA and all the field calculations were performed using commercial electromagnetic field analysis code, OPERA-3D TOSCA. From this research, we expect a time reduction for FDG production, a decrease of radioactive exposure for workers, and an equipment cost reduction.

  1. Development of Cyclotron Beam Technology for Applications in Materials Science and Biotechnology at JAERI-TIARA

    NASA Astrophysics Data System (ADS)

    Ohara, Y.; Arakawa, K.; Fukuda, M.; Kamiya, T.; Kurashima, S.; Nakamura, Y.; Okumura, S.; Saidoh, M.; Tajima, S.

    2003-08-01

    Recent progress of cyclotron ion beam development for applications in materials science and biotechnology at the ion-irradiation research facility TIARA of the Japan Atomic Energy Research Institute(JAERI) is overviewed. The AVF cyclotron in TIARA can accelerate protons and heavy ions up to 90 MeV and 27.5 MeV/n, respectively. In order to conform to the requirement of a reliable tuning of microbeam formation, the cyclotron beam current has been stabilized by controlling the temperature of the magnet yoke and pole within +/-0.5° and hence by decreasing the variation of the magnetic field ?B/B below 10-5. A heavy ion microbeam with energy of hundreds MeV is a significantly useful probe for researches on biofunctional elucidation in biotechnology. Production of the microbeam with spot size as small as 1?m by quadrupole lenses requires the energy spread of the beam ?E/E < 2 × 10-4. In order to minimize the energy spread of the cyclotron beam, the fifth-harmonic voltage waveform has been successfully superposed on the fundamental one to make energy gain uniform.

  2. Space charge frequency shifts of the cyclotron modes in multi-species ion plasmas.

    PubMed

    Affolter, M; Anderegg, F; Driscoll, C F

    2015-02-01

    Shifts of the cyclotron frequency away from the "bare" cyclotron frequency are observed to be proportional to the total ion density through the E?×?B rotation frequency, and to the relative concentration of each ion species, in quantitative agreement with analytic theory. These shifts are measured at small excitation amplitudes on the typical center-of-mass m?=?1 mode, and also on cyclotron modes with m?=?0 and m?=?2 azimuthal dependence. The frequency spacing between these modes is proportional to the rotation frequency of the ion cloud, which is controlled and measured using a "rotating wall" and laser-induced fluorescence. These cylindrical ion plasmas consist of Mg(+) isotopes, with H3 O (+) and O2 (+) impurities. It is observed that the shift in the m?=?1 cyclotron frequency is larger for the minority species (25)Mg(+) and (26)Mg(+), than for the majority species (24)Mg(+). A simple center-of-mass model is presented, which is in quantitative agreement with these results. It is also shown that this model interprets and expands the intensity dependent calibration equation, (M/q)?=?A/f?+?B/f (2)?+?CI/f (2). PMID:25450158

  3. Electron-cyclotron wave scattering by edge density fluctuations in ITER

    SciTech Connect

    Tsironis, Christos [School of Electrical and Computer Engineering, National Technical University of Athens, Athens GR 15773 (Greece); Department of Physics, Aristotle University of Thessaloniki, Thessaloniki GR 54006 (Greece); Peeters, Arthur G. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Isliker, Heinz; Chatziantonaki, Ioanna; Vlahos, Loukas [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki GR 54006 (Greece); Strintzi, Dafni [School of Electrical and Computer Engineering, National Technical University of Athens, Athens GR 15773 (Greece)

    2009-11-15

    The effect of edge turbulence on the electron-cyclotron wave propagation in ITER is investigated with emphasis on wave scattering, beam broadening, and its influence on localized heating and current drive. A wave used for electron-cyclotron current drive (ECCD) must cross the edge of the plasma, where density fluctuations can be large enough to bring on wave scattering. The scattering angle due to the density fluctuations is small, but the beam propagates over a distance of several meters up to the resonance layer and even small angle scattering leads to a deviation of several centimeters at the deposition location. Since the localization of ECCD is crucial for the control of neoclassical tearing modes, this issue is of great importance to the ITER design. The wave scattering process is described on the basis of a Fokker-Planck equation, where the diffusion coefficient is calculated analytically as well as computed numerically using a ray tracing code.

  4. Magnetic field modification of 18 GHz electron cyclotron resonance ion source at the Japan Atomic Energy Research Institute

    Microsoft Academic Search

    W. Yokota; Y. Saitoh; T. Nara; Y. Ishii; K. Arakawa

    2000-01-01

    An 18 GHz electron cyclotron resonance ion source under development since. 1994 has a solenoid coil between a pair of mirror coils to vary the mirror ratio over a wide range. The solenoid coil of the original design formed a small bump in the bottom of the mirror field profile when the source parameters were optimized for high charge states.

  5. Ion cyclotron waves in the Io torus: Wave dispersion, free energy analysis, and SO 2 + source rate estimates

    Microsoft Academic Search

    D. E. Huddleston; R. J. Strangeway; J. Warnecke; C. T. Russell; M. G. Kivelson

    1998-01-01

    As the Galileo spacecraft passed through the I0 torus, ion cyclotron waves were observed near the sulfur dioxide ion gyrofrequency. The toms plasma is continually replenished by the ionization of neutral particles from I0. It is well known that sulfur dioxide dissociates rapidly, so that the corotating toms plasma consists of predominantly sulfur and oxygen ions. However, for the small

  6. Resonant cyclotron acceleration of particles by a time periodic singular flux tube

    E-print Network

    Joachim Asch; Tomas Kalvoda; Pavel Stovicek

    2011-03-15

    We study the dynamics of a classical nonrelativistic charged particle moving on a punctured plane under the influence of a homogeneous magnetic field and driven by a periodically time-dependent singular flux tube through the hole. We observe an effect of resonance of the flux and cyclotron frequencies. The particle is accelerated to arbitrarily high energies even by a flux of small field strength which is not necessarily encircled by the cyclotron orbit; the cyclotron orbits blow up and the particle oscillates between the hole and infinity. We support this observation by an analytic study of an approximation for small amplitudes of the flux which is obtained with the aid of averaging methods. This way we derive asymptotic formulas that are afterwards shown to represent a good description of the accelerated motion even for fluxes which are not necessarily small. More precisely, we argue that the leading asymptotic terms may be regarded as approximate solutions of the original system in the asymptotic domain as the time tends to infinity.

  7. Coronal ion-cyclotron beam instabilities within the multi-fluid description

    E-print Network

    R. Mecheri; E. Marsch

    2007-06-07

    Spectroscopic observations and theoretical models suggest resonant wave-particle interactions, involving high-frequency ion-cyclotron waves, as the principal mechanism for heating and accelerating ions in the open coronal holes. However, the mechanism responsible for the generation of the ion-cyclotron waves remains unclear. One possible scenario is that ion beams originating from small-scale reconnection events can drive micro-instabilities that constitute a possible source for the excitation of ion-cyclotron waves. In order to study ion beam-driven electromagnetic instabilities, the multi-fluid model in the low-beta coronal plasma is used. While neglecting the electron inertia this model allows one to take into account ion-cyclotron wave effects that are absent from the one-fluid MHD model. Realistic models of density and temperature as well as a 2-D analytical magnetic field model are used to define the background plasma in the open-field funnel region of a polar coronal hole. Considering the WKB approximation, a Fourier plane-wave linear mode analysis is employed in order to derive the dispersion relation. Ray-tracing theory is used to compute the ray path of the unstable wave as well as the evolution of the growth rate of the wave while propagating in the coronal funnel. We demonstrate that, in typical coronal holes conditions and assuming realistic values of the beam velocity, the free energy provided by the ion beam propagating parallel the ambient field can drive micro-instabilities through resonant ion-cyclotron excitation.

  8. A KINETIC MODEL OF SOLAR WIND GENERATION BY OBLIQUE ION-CYCLOTRON WAVES

    SciTech Connect

    Isenberg, Philip A.; Vasquez, Bernard J. [Institute for the Study of Earth, Oceans and Space and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States)

    2011-04-20

    The fast solar wind is generated by extended perpendicular ion heating in coronal holes, but the kinetic mechanism responsible for this heating has not been determined. One long-standing possibility is the resonant-cyclotron dissipation of ion-cyclotron waves, replenished from a turbulent cascade of interacting counter-propagating Alfven waves. We present results of a kinetic model for proton heating by the quasilinear resonant-cyclotron wave-particle interaction in a coronal hole. The resonant wave spectrum is taken as a power law in wavenumber, uniformly distributed in propagation direction between 0 deg. and 60 deg. with respect to the large-scale radial magnetic field. We obtain the steady-state solution of the kinetic guiding-center equation for the proton distribution in an expanding coronal hole, including the effects of large-scale forces of gravity, charge-separation electric field, Alfven wave ponderomotive force, and mirror force, along with the small-scale scattering from the wave dissipation. We find that plausible wave intensities can yield reasonable flow speeds and temperatures in the heliocentric radial range between 2 and 6 solar radii. We address the claim in earlier work that dissipation of parallel-propagating ion-cyclotron waves cannot provide enough acceleration and show that claim to be incorrect. We find that the combined action of the large-scale forces and the resonant-cyclotron scattering produces proton distribution functions with a characteristic structure: compressed in the sunward half of velocity space with a high-density shell separate from the origin, and relatively expanded in the anti-sunward half of velocity space. We suggest that qualitatively similar proton distributions would result from the kinetic evolution of any sufficiently effective perpendicular heating mechanism operating in an expanding coronal hole.

  9. C235-V3 cyclotron for a proton therapy center to be installed in the hospital complex of radiation medicine (Dimitrovgrad)

    NASA Astrophysics Data System (ADS)

    Galkin, R. V.; Gurskii, S. V.; Jongen, Y.; Karamysheva, G. A.; Kazarinov, M. Yu.; Korovkin, S. A.; Kostromin, S. A.; Calderan, J.-M.; Cahay, P.; Mokrenko, S. P.; Morozov, N. A.; Nkongolo, H.; Ol'shevskii, A. G.; Paradis, Y.; Petrov, D. S.; Romanov, V. M.; Samsonov, E. V.; Syresin, E. M.; Shakun, A. N.; Shakun, N. G.; Shirkov, G. D.; Shirkov, S. G.

    2014-06-01

    Proton therapy is an effective method of treating oncologic diseases. In Russia, construction of several centers for proton and ion therapy is slated for the years to come. A proton therapy center in Dimitrovgrad will be the first. The Joint Institute for Nuclear Research (Russia) in collaboration with Ion Beam Application (IBA) (Belgium) has designed an C235-V3 medical proton cyclotron for this center. It outperforms previous versions of commercial IBA cyclotrons, which have already been installed in 11 oncologic hospital centers in different countries. Experimental and calculation data for the beam dynamics in the C235-V3 medical cyclotron are presented. Reasons for beam losses during acceleration are considered, the influence of the magnetic field radial component in the midplane of the accelerator and main resonances is studied, and a beam extraction system is designed. In 2011-2012 in Dubna, the cyclotron was mounted, its magnetic field was properly configured, acceleration conditions were optimized, and beam extraction tests were carried out after which it was supplied to Dimitrovgrad. In the C235-V3 cyclotron, an acceleration efficiency of 72% and an extraction efficiency of 62% have been achieved without diaphragming to form a vertical profile of the beam.

  10. Medical Assistants

    MedlinePLUS

    ... clinical work. Administrative medical assistants often fill out insurance forms or code patients’ medical information. They often ... may update a patient’s medical file, fill out insurance forms, and answer telephone calls in a practitioner’s ...

  11. Cyclotron Maser Emission from Blazar Jets?

    E-print Network

    Begelman, M C; Rees, Martin J; Begelman, Mitchell C.; Ergun, Robert E.; Rees, Martin J.

    2005-01-01

    We consider the production of electron cyclotron maser emission by low-density, highly magnetized plasmas in relativistic jets. The population inversion required to drive cyclotron maser instability could occur in localized, transient sites where hydromagnetic instabilities, shocks, and/or turbulence lead to magnetic mirroring along current-carrying flux tubes. The maser is pumped as electrons are accelerated by the parallel electric field that develops as a result of the mirror. We estimate the maximum brightness temperatures that can be obtained in a single maser site and in an array of many masers operating simultaneously, under conditions likely to apply in blazar jets. Synchrotron absorption, by relativistic electrons within the jet, presents the largest obstacle to the escape of the maser radiation, and may render most of it invisible. However, we argue that a high brightness temperature could be produced in a thin boundary layer outside the synchrotron photosphere, perhaps in the shear layer along the ...

  12. 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).

  13. A model for cyclotron resonance scattering features

    E-print Network

    G. Schönherr; J. Wilms; P. Kretschmar; I. Kreykenbohm; A. Santangelo; R. E. Rothschild; W. Coburn; R. Staubert

    2007-07-13

    (abbreviated version of the abstract) We study the physics of cyclotron line formation in the high-energy spectra of accreting X-ray pulsars using Monte Carlo methods, assuming that the line-forming region is a low-density electron plasma in a sub-critical magnetic field. We investigate the dependence of the shape of the fundamental line on angle, geometry, optical depth and temperature. We also discuss variations of the line ratios for non-uniform magnetic fields. These numerical predictions for the line profiles are linked to results from observational data analysis using an XSPEC model based on the Monte Carlo simulations. We apply this model to observational data from RXTE and INTEGRAL. The predicted strong emission wings of the fundamental cyclotron feature are not found in observational data, hinting at a bottom illuminated slab geometry for line formation.

  14. 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.

  15. 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.

  16. 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.

  17. 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).

  18. Superconducting cyclotron and its vacuum system

    Microsoft Academic Search

    A. Sur; R. K. Bhandari

    2008-01-01

    A large superconducting cyclotron is under construction at this Centre and will be used to accelerate heavy ion beams to energy up to 80 MeV\\/A for light heavy ions and about 10 MeV\\/A for medium mass heavy ions. The vacuum system for this accelerator has several different aspects. The main acceleration chamber will be evacuated to a level of about

  19. Liquid stub tuner for ion cyclotron heating

    Microsoft Academic Search

    R. Kumazawa; T. Mutoh; T. Seki; F. Sinpo; G. Nomura; T. Ido; T. Watari; Jean-Marie Noterdaeme; Yangping Zhao

    1999-01-01

    Ion cyclotron range of frequency (ICRF) heating on the large helical device (LHD) is characterized by high power (up to 12 MW) and steady state operation (30 min). The LHD is a helical device (with a major radius of 3.9 m and a minor radius of 0.6 m) with superconducting coil windings (l=2, m=10). The main purpose of physical research

  20. The Superconducting Separated Orbit Cyclotron Tritron

    Microsoft Academic Search

    U. Trinks; W. Assmann; L. Dietl; G. Hinderer; H. J. Körner; A. Platzer; B. Rehm; K. Rieger; C. Riess; R. Savoy; M. Wandinger; W. Wiedemann

    1985-01-01

    At the Munich 13 MV-Tandem Laboratory the TRITRON is under development, which will be the prototype of a superconducting separated orbit cyclotron for acceleration of heavy ions with 0.04 < i 0.14 and 0.1 0.3. It consists of 12 flat, superconducting sector magnets with 20 neighbouring channels for the spiral-orbit (rin = 70 cm, re, = 150 cm). Due to

  1. Characterization of electron cyclotron resonance hydrogen plasmas

    Microsoft Academic Search

    C. A. Outten; J. C. Barbour; W. R. Wampler

    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

  2. Cyclotron Maser Emission from Blazar Jets?

    E-print Network

    Mitchell C. Begelman; Robert E. Ergun; Martin J. Rees

    2005-02-07

    We consider the production of electron cyclotron maser emission by low-density, highly magnetized plasmas in relativistic jets. The population inversion required to drive cyclotron maser instability could occur in localized, transient sites where hydromagnetic instabilities, shocks, and/or turbulence lead to magnetic mirroring along current-carrying flux tubes. The maser is pumped as electrons are accelerated by the parallel electric field that develops as a result of the mirror. We estimate the maximum brightness temperatures that can be obtained in a single maser site and in an array of many masers operating simultaneously, under conditions likely to apply in blazar jets. Synchrotron absorption, by relativistic electrons within the jet, presents the largest obstacle to the escape of the maser radiation, and may render most of it invisible. However, we argue that a high brightness temperature could be produced in a thin boundary layer outside the synchrotron photosphere, perhaps in the shear layer along the wall of the jet. Induced Compton scattering provides additional constraints on the maximum brightness temperature of a masing jet. We suggest that recent observations of diffractive scintillation in the blazar J1819+3845, indicating intrinsic brightness temperatures greater than 10^{14} K at 5 GHz, may be explained in terms of cyclotron maser emission. High brightness temperature maser emission from blazar jets may extend to frequencies as high as ~100 GHz, with the maximum possible T_B scaling roughly as 1/frequency. Less massive relativistic jet sources, such as microquasars, are even better candidates for producing cyclotron maser emission, primarily in the infrared and optical bands.

  3. Nonconvective and convective electron cyclotron harmonic instabilities

    Microsoft Academic Search

    M. Ashour-Abdalla; C. F. Kennel

    1978-01-01

    The article discusses nonconvective and convective electron-cyclotron harmonic instabilities. Particularly, the spatial growth rates of electrostatic waves in an electron plasma having hot and cold components and a weak loss cone perpendicular velocity distribution are investigated. It is found that the cold-electron density controls which harmonic band may be excited and that the cold-electron temperature controls spatial amplification. The nonconvective

  4. Beryllium10 mass spectrometry with a cyclotron

    Microsoft Academic Search

    G. M. Raisbeck; F. Yiou; M. Fruneau; J. M. Loiseaux

    1978-01-01

    The Grenoble cyclotron has been used as a mass spectrometer to measure ratios of 10 to 9 of 10⁻⁸, 10⁻⁹, and 10⁻¹° in standardized beryllium oxide samples. Similar measurements can be used to determine cosmogenic 10 (half-life, 1.5 x 10⁶ years) profiles in various geophysical reservoirs such as sea sediments and polar ice. This procedure can be used either to

  5. 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.

  6. Operation of a quasioptical electron cyclotron maser

    SciTech Connect

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

    1984-12-01

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

  7. RF cavity simulations for superconducting cyclotron C400

    Microsoft Academic Search

    Y. Jongen; M. Abs; W. Kleeven; S. Zaremba; A. A. Glazov; S. V. Gurskiy; O. V. Karamyshev; G. A. Karamysheva; N. A. Morozov

    2011-01-01

    Compact superconducting isochronous cyclotron C400 [1] has been designed at IBA (Belgium) in collaboration with the JINR (Dubna). This cyclotron will be the first cyclotron in\\u000a the world capable of delivering protons, carbon and helium ions for therapeutic use. 12C6+ and 4He2+ ions will be accelerated to 400 MeV\\/u energy and extracted by electrostatic deflector, H2+ ions will be accelerated

  8. 76 FR 80982 - International Cyclotron, Inc., Hato Rey, Puerto Rico; Order Suspending Licensed Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-27

    ...EA-11-086; NRC-2011-0292] International Cyclotron, Inc., Hato Rey, Puerto Rico; Order Suspending Licensed Activities I International Cyclotron, Inc. (International Cyclotron; Licensee) is the holder of Byproduct...

  9. Radially Localized Measurements of Superthermal Electrons Using Oblique Electron Cyclotron Emission

    E-print Network

    Radially Localized Measurements of Superthermal Electrons Using Oblique Electron Cyclotron Emission Cyclotron Emission from superthermalelectrons can be imposed by observationof emission upshiftedfrom the thermal cyclotron resonance in the horizontal midplane of a tokamak. A new and unique diagnostic has been

  10. The LBL (Lawrence Berkeley Laboratory) 88-inch cyclotron operating with an ECR source

    SciTech Connect

    Clark, D.J.

    1986-10-01

    The features and operation of the LBL 88-inch Cyclotron are described, including its ECR source, injection system, and the cyclotron center region. The beams that have been accelerated at the cyclotron are discussed. (LEW)

  11. Electromagnetic ion cyclotron waves at proton cyclotron C. C. Chaston, J. W. Bonnell, J. P. McFadden, R. E. Ergun, and C. W. Carlson

    E-print Network

    California at Berkeley, University of

    Electromagnetic ion cyclotron waves at proton cyclotron harmonics C. C. Chaston, J. W. Bonnell, J; published 7 November 2002. [1] Waves with frequencies in the vicinity of the proton cyclotron frequency electromagnetic at cyclotron harmonics while simultaneously giving rise to broadband electrostatic emissions

  12. Medical telesensors

    NASA Astrophysics Data System (ADS)

    Ferrell, Trinidad L.; Crilly, P. B.; Smith, S. F.; Wintenberg, Alan L.; Britton, Charles L., Jr.; Morrison, Gilbert W.; Ericson, M. N.; Hedden, D.; Bouldin, Donald W.; Passian, A.; Downey, Todd R.; Wig, A. G.; Meriaudeau, Fabrice

    1998-05-01

    Medical telesensors are self-contained integrated circuits for measuring and transmitting vital signs over a distance of approximately 1-2 meters. The circuits are unhoused and contain a sensor, signal processing and modulation electronics, a spread-spectrum transmitter, an antenna and a thin-film battery. We report on a body-temperature telesensor, which is sufficiently small to be placed on a tympanic membrane in a child's ear. We also report on a pulse-oximeter telesensor and a micropack receiver/long- range transmitter unit, which receives form a telesensor array and analyzes and re-transmits the vital signs over a longer range. Signal analytics are presented for the pulse oximeter, which is currently in the form of a finger ring. A multichip module is presented as the basic signal-analysis component. The module contains a microprocessor, a field=programmable gate array, memory elements and other components necessary for determining trauma and reporting signals.

  13. Bio-Nano ECRIS: An electron cyclotron resonance ion source for new materials production

    SciTech Connect

    Uchida, T. [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Minezaki, H. [Graduate School of Engineering, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Tanaka, K.; Asaji, T. [Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama, Toyama 930-1305 (Japan); Muramatsu, M.; Kitagawa, A. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Biri, S. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem Ter 18/c (Hungary); Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan); Graduate School of Engineering, Toyo University, 2100, Kujirai, Kawagoe, Saitama 350-8585 (Japan)

    2010-02-15

    We developed an electron cyclotron resonance ion source (ECRIS) for new materials production on nanoscale. Our main target is the endohedral fullerenes, which have potential in medical care, biotechnology, and nanotechnology. In particular, iron-encapsulated fullerene can be applied as a contrast material for magnetic resonance imaging or microwave heat therapy. Thus, our new ECRIS is named the Bio-Nano ECRIS. In this article, the recent progress of the development of the Bio-Nano ECRIS is reported: (i) iron ion beam production using induction heating oven and (ii) optimization of singly charged C{sub 60} ion beam production.

  14. A real-time beam-profile monitor for a PET cyclotron

    SciTech Connect

    Hoehr, C.; Uittenbosch, T.; Verzilov, V.; English, W.; Buckley, K.; Gray, D.; Kellog, S.; Cameron, D.; Schaffer, P. [TRIUMF, 4004 Wesbrook Mall, V6T 2A3 Vancouver (Canada)

    2012-12-19

    Beam profiles in medical cyclotrons are traditionally measured using techniques that do not provide any information about short-term fluctuations of the beam shape or beam intensity. To overcome this, we have developed a real-time harp beam profile monitor which can withstand beam power in excess of 300 W. The monitor and electronics were constructed and applied toward a 13 MeV proton beam with current of up to 25 {mu}A. Herein are reported preliminary beam-profile measurement results.

  15. Cyclotron dynamics of interacting bosons in artificial magnetic fields

    E-print Network

    Xiaopeng Li; S. Das Sarma

    2014-06-24

    We study theoretically quantum dynamics of interacting bosons in artificial magnetic fields as engineered in recent ultracold atomic experiments, where quantum cyclotron orbital motion has been observed. With exact numerical simulations and perturbative analyses, we find that interactions induce damping in the cyclotron motion. The damping time is found to be dependent on interaction and tunneling strengths monotonically, while its dependence on magnetic flux is non-monotonic. Sufficiently strong interactions would render bosons dynamically localized inhibiting the cyclotron motion. The damping predicted by us can be construed as an interaction-induced quantum decoherence of the cyclotron motion.

  16. The surface-state of the topological insulator Bi2Se3 revealed by cyclotron resonance

    SciTech Connect

    Mcdonald, Ross D [Los Alamos National Laboratory; Ayala - Valenzuela, Oscar E [Los Alamos National Laboratory; Altarawneh, Moaz M [Los Alamos National Laboratory; Analytis, James G [STANFORD UNIV/SLAC; Chu, J. H. [STANFORD UNIV/SLAC; Fisher, R. [STANFORD UNIV/SLAC

    2011-01-14

    Transport measurements of topological insulators are dominated by the conductivity of the bulk, leading to substantial difficulties in resolving the properties of the surface. To this end, we use high magnetic field, rf- and microwave-spectroscopy to selectively couple to the surface conductivity of Bi2Se3 at high frequency. In the frequency range of a few GHz we observe a crossover from quantum oscillations indicative of a small 3D Fermi surface, to cyclotron resonance indicative of a 2D surface state. By probing the conductivity at reduced skin depths, we have observed a 2D cyclotron resonance from a material whose bulk Fermi-surface is 3D. The frequency-magnetic field scaling of this resonance is inconsistent with the bulk effective mass, but more consistent with the dispersion and band filling of a Dirac-like surface state as observed by ARPES, with substantial manybody renormalization.

  17. Medical Matrix

    NSDL National Science Digital Library

    Medical Matrix is a Web resource that offers a database of Internet clinical medicine resources. Medical Matrix categorizes resources by disease, specialty, and other interest areas. It is designed as a "home page" for a physician's or healthworker's computer. Medical Matrix is a project of the Internet Working Group of the American Medical Informatics Association.

  18. Quality inspection of small diameter polymeric medical tubing and attached wire stent using TAP-NDE and the Gabor Wavelet Transform

    E-print Network

    Harms, Kent David

    2001-01-01

    A non-contact, laser-optic based technique referred to as the Thermo-Acousto-Photonic Nondestructive Evaluation (TAP-NDE) was utilized to investigate bond integrity and localized stiffening due to an attached wire stent on small diameter polymeric...

  19. Assessment of quality of life in small-cell lung cancer using a Daily Diary Card developed by the Medical Research Council Lung Cancer Working Party

    Microsoft Academic Search

    PM Fayers; NM Bleehen; DJ Girling; RJ Stephens

    1991-01-01

    Three hundred and sixty-nine patients in an MRC study of combination chemotherapy and radiotherapy for small-cell lung cancer of limited extent were asked to complete a Daily Diary Card which enabled an assessment of their quality of life to be made during and after treatment. The information derived from the card suggests that although cytotoxic chemotherapy has an adverse effect

  20. Operational performance of the LBL 88-inch cyclotron with an ECR (Electron Cyclotron Resonance) source

    SciTech Connect

    Lyneis, C.M.

    1986-10-01

    The 88-Inch Cyclotron began regular operation with the ECR (Electron Cyclotron Resonance) source in January 1985. Since then about 80% of the cyclotron operating schedule has been with the ECR source. The light-ion filament source is used only for runs two or more shifts in length using proton, deuteron, /sup 3/He, or alpha beams. Occasionally the polarized ion source is used. The heavy-ion PIG sources are no longer used. The operating experience with the Cyclotron + ECR has been highly successful in terms of reliability, stability, production of high charge state currents, and range of ions which can be produced. The performance of the Cyclotron + ECR has steadily improved since regular operation began. The improvement is a result of better source performance, better stability and tuning of the injection line, and better cyclotron tuning. Development of the ECR source has resulted in improved high charge state performance and a greater variety of ion species. The LBL ECR now produces 14 ..mu..A of O/sup 7 +/, 1 ..mu..A of O/sup 8 +/, 72 ..mu..A of Ar/sup 9 +/, 1.4 ..mu..A of Ar/sup 14 +/, 5 ..mu..A of I/sup 25 +/, and .009 ..mu..A of I/sup 30 +/. Metal ions from Mg, K, and Ca are produced in the ECR using an oven to inject vapor into the plasma chamber. Operation with the oven is quite stable and frequently requires no adjustment during runs lasting several days. Beams of F, Si, S, and Ti have been produced using various compounds as gases or solids with the oven. The overall transmission from source analyzing magnet to cyclotron external beam is typically 2 to 10% with a maximum of 17%. As a result of the improved source performance and transmission a wide variety of new beams can be produced. For example, a 32.5 MeV/u /sup 16/O/sup 8 +/ beam and /sup 48/Ca/sup 11 +/ beams with energy from 200 to 350 MeV have been used for nuclear physics experiments. A 1.08 GeV /sup 36/Ar/sup 18 +/ beam was used to test the response of various scintillator materials to intermediate energy heavy ions.

  1. Impurity cyclotron resonance of anomalous Dirac electrons in graphene.

    PubMed

    Kim, S C; Yang, S-R Eric; MacDonald, A H

    2014-08-13

    We have investigated a new feature of impurity cyclotron resonances common to various localized potentials of graphene. A localized potential can interact with a magnetic field in an unexpected way in graphene. It can lead to formation of anomalous boundstates that have a sharp peak with a width R in the probability density inside the potential and a broad peak of size magnetic length ? outside the potential. We investigate optical matrix elements of anomalous states and find that they are unusually small and depend sensitively on the magnetic field. The effect of many-body interactions on their optical conductivity is investigated using a self-consistent time-dependent Hartree-Fock approach. For a completely filled Landau level we find that an excited electron-hole pair, originating from the optical transition between two anomalous impurity states, is nearly uncorrelated with other electron-hole pairs, although it displays substantial exchange self-energy effects. This absence of correlation is a consequence of a small vertex correction in comparison to the difference between renormalized transition energies computed within the one electron-hole pair approximation. However, an excited electron-hole pair originating from the optical transition between a normal and an anomalous impurity state can be substantially correlated with other electron-hole states with a significant optical strength. PMID:25049042

  2. The beam bunching system for the Chalk River superconducting cyclotron

    Microsoft Academic Search

    E. A. Heighway; C. B. Bigham; J. E. McGregor

    1983-01-01

    The bunching system for the tandem accelerator-superconducting cyclotron is of the buncher-rebuncher type. It consists of a low energy gridded buncher before the tandem that produces a time focus at the tandem stripper, combined with a high energy buncher between the tandem and the cyclotron to correct for debunching of the beam produced by energy straggling in the stripper. To

  3. The Upgrade Project at Texas A&M Cyclotron Institute

    Microsoft Academic Search

    G. Tabacaru; J. Ärje; F. Abegglen; G. Chubaryan; G. Derrig; H. L. Clark; G. Kim; D. May; G. Souliotis; R. E. Tribble

    2008-01-01

    The Cyclotron Institute at Texas A&M University is currently under an upgrade process. The plan is to produce re-accelerated radioactive ion beams using the recommissioned 88'' Cyclotron as a driver and two different devices. The technique for producing radioactive species will be presented.

  4. The Upgrade Project at Texas A and M Cyclotron Institute

    SciTech Connect

    Tabacaru, G.; Abegglen, F.; Chubaryan, G.; Derrig, G.; Clark, H. L.; Kim, G.; May, D.; Souliotis, G.; Tribble, R. E. [Cyclotron Institute Texas A and M University, College Station, 77843 TX (United States); Aerje, J. [JYFL, Jyvaeskylae (Finland)

    2008-01-24

    The Cyclotron Institute at Texas A and M University is currently under an upgrade process. The plan is to produce re-accelerated radioactive ion beams using the recommissioned 88'' Cyclotron as a driver and two different devices. The technique for producing radioactive species will be presented.

  5. The Texas A & M K500 cyclotron facility

    Microsoft Academic Search

    D. H. Youngblood

    1991-01-01

    A K500 superconducting cyclotron, following the MSU design, has been constructed with funds provided by Texas A & M University and The Robert A. Welch Foundation. First beam was extracted in June, 1988, and the first experiments were performed shortly afterward in July using a PIG internal ion source. An electron-cyclotron resonance ion source was constructed and delivered first beam

  6. Operating experience with an ion source in a superconducting cyclotron

    Microsoft Academic Search

    T. A. Antaya; J. A. Kuchar; M. L. Mallory

    1983-01-01

    The authors have developed a PIG ion source for axial insertion in the K500 cyclotron. The operation of the ion source has been limited to the requirements demanded by the operation of the cyclotron. These requirements have been for moderate charge state light heavy ions, of principally carbon, nitrogen and neon. The source design is more than adequate for moderate

  7. Performance of H-\\/D- cyclotron using internal source

    Microsoft Academic Search

    T. T. Y. Kuo; G. O. Hendry

    1993-01-01

    Over the past ten years, several models of H-\\/D- compact cyclotrons using an internal source have been constructed and put into routine operation. This paper reports the performance of some of these machines. A detailed description on individual cyclotrons is omitted in order to give space for discussion on the design guidelines and the criteria which warrant the high beam

  8. Nonlinear steepening of the electrostatic ion cyclotron wave

    Microsoft Academic Search

    M. Temerin; M. Woldorff; F. S. Mozer

    1979-01-01

    Observations of the nonlinear steepening of the electrostatic hydrogen cyclotron wave at altitudes between 5000 and 8000 km above the auroral regions of the earth's ionosphere are reported, and interpreted in terms of the nonlinear fluid equations for the electrostatic ion cyclotron wave. Measurements of the electric field were obtained by three orthogonally oriented pairs of spherical detectors on board

  9. Cyclotron Maser Radiation from an Inhomogeneous Plasma

    SciTech Connect

    Cairns, R. A.; Vorgul, I. [University of St Andrews, School of Mathematics and Statistics, St Andrews, Fife, Scotland, KY16 9SS (United Kingdom); Bingham, R. [STFC Rutherford Appleton Lab, Space Science and Technology Dept, Didcot, Oxon, OX11 0QX (United Kingdom); Physics Department, University of Strathclyde, Glasgow, G4 0NG (United Kingdom)

    2008-11-21

    Cyclotron maser radiation is important in both laboratory devices such as gyrotrons and in space physics applications to phenomena such as auroral kilometric radiation. To understand the behavior, especially in the latter case where there is generally a localized region of instability, requires an understanding of how such instabilities behave in an inhomogeneous plasma. Here we consider, for simplicity, a simple ring distribution of electrons in either a step function variation of magnetic field or a continuous gradient. In each case we show that there can exist localized regions of instability from which waves, growing in time, can be radiated outwards.

  10. Cyclotron maser using the anomalous Doppler effect

    Microsoft Academic Search

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

    1983-01-01

    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

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

    SciTech Connect

    NONE

    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.

  12. Electron cyclotron emission diagnostics on KSTAR tokamak

    SciTech Connect

    Jeong, S. H. [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Daejeon 305-353 (Korea, Republic of); Lee, K. D.; Kwon, M. [National Fusion Research Institute, 113 Gwahangno, Daejeon 305-333 (Korea, Republic of); Kogi, Y. [Fukuoka Institute of Technology, Higashiku, Fukuoka 811-0295 (Japan); Kawahata, K.; Nagayama, Y. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Mase, A. [KASTEC, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

    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.

  13. Cavity QED of the graphene cyclotron transition

    E-print Network

    David Hagenmüller; Cristiano Ciuti

    2011-11-15

    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 occuring in the Dicke-model is predicted for increasing value of the electron density.

  14. IsoRay Medical William A. Cavanagh

    E-print Network

    IsoRay Medical William A. Cavanagh Vice President of Research and Development IsoRay Medical March 2011 #12;IsoRay Medical AMEX: ISR Founded: 1998 Richland, Washington Employees: 35 Market Cap (3/3/11): 32.5M #12;IsoRay Medical 1901: Pierre Curie suggests that a small radium tube be inserted

  15. ICRH of JET and LHD Majority Ions at Their Fundamental Cyclotron Frequency

    NASA Astrophysics Data System (ADS)

    Krasilnikov, A. V.; Van Eester, D.; Lerche, E.; Ongena, J.; Mailloux, J.; Stamp, M.; Jachmich, S.; Leggate, H.; Vdovin, V.; Walden, A.; Mayoral, M.-L.; Bonheure, G.; Santala, M.; Kiptily, V.; Popovichev, S.; Biewer, T.; Crombe, K.; Esposito, B.; Marocco, D.; Riva, M.; Kaschuck, Yu. A.; Amosov, V. N.; Ericsson, G.; Giacomelli, L.; Hellesen, C.; Hjalmarsson, A.; Kallne, J.; Isobe, M.; Nishiura, M.; Sasao, M.; Nishimura, H.; Saito, K.; Seki, T.; Mutoh, T.; Kumazawa, R.; Takeiri, Y.; Osakabe, M.; Goto, M.; Murakami, S.; Goncharov, P.

    2007-09-01

    Results of the experimental studies of ICRH at the fundamental cyclotron frequency of the majority deuterons in JET plasmas with near-tangential deuteron neutral beam injection (NBI) are presented. 1D, 2D and 3D ICRH modeling indicated that several ITER relevant mechanisms of heating may occur simultaneously in this heating scheme: fundamental ion cyclotron resonance heating of majority and beam D ions, impurity ion heating and electron heating due to Landau damping and TTMP. These mechanisms were studied in JET experiments with a ˜90% D, 5% H plasma including traces of Be and Ar. Up to 2MW of ICRH power was applied at 25 MHz to NBI heated plasmas. In most of the discharges the toroidal magnetic field strength was 3.3T, but in one it was equal to 3.6T. The E+ component of the electric field governs the ion cyclotron heating of not too fast particles. The Doppler shifted RF absorption of the beam deuterons away from the cold resonance at which E+ is small was exploited to enhance the RF power absorption efficiency. Fundamental ICRH experiments were also carried out in LHD hydrogen plasma with high energy hydrogen NBI. ICRH was performed at 38MHz with injected power <1 MW. The effect of fundamental ICRH was clearly demonstrated in both machines.

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

    PubMed

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

    2013-11-01

    Variable Energy Cyclotron Centre (VECC) has commissioned K500 Superconducting cyclotron (SCC) based on MSU and Texas A&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. PMID:24289392

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    Variable Energy Cyclotron Centre (VECC) has commissioned K500 Superconducting cyclotron (SCC) based on MSU and Texas A&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. 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 [Variable Energy Cyclotron Centre, Kolkata (India)] [Variable Energy Cyclotron Centre, Kolkata (India)

    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.

  19. Medical Management

    MedlinePLUS

    ... form Search Charcot-Marie-Tooth Disease (CMT) Medical Management Although there’s no cure for CMT, there are ... individualized physical therapy program. For more on medical management of CMT, see Surgery Sometimes, Bracing Often, Caution ...

  20. Oral Medication

    MedlinePLUS

    ... doctor before starting anything new — even over-the-counter items. Explore: Oral Medication How Much Do Oral Medications Cost? Save money by finding the right type and dosage of medicine for your needs. In this section Treatment and ...

  1. Medication Errors

    MedlinePLUS

    ... Reviewers - Medical Device Use-Safety: Incorporating Human Factors Engineering into Risk Management (PDF - 1.1MB) Draft Guidance ... Drug Administration Staff - Applying Human Factors and Usability Engineering to Optimize Medical Device Design Spotlight Guidance for ...

  2. Medical Transcriptionists

    MedlinePLUS

    ... an understanding of medical terminology, anatomy and physiology, grammar, and word-processing software. Pay The median annual ... an understanding of medical terminology, anatomy and physiology, grammar, and word-processing software. Education Employers prefer to ...

  3. Cyclotron radiation and emission in graphene

    NASA Astrophysics Data System (ADS)

    Morimoto, Takahiro; Hatsugai, Yasuhiro; Aoki, Hideo

    2008-03-01

    While the physics of ``Massless Dirac" particles in graphene has been kicked off by the observation of an anomalous quantum Hall effect, interests begin to extend optical properties, which includes recent spectroscopy studies on unevenly spaced Landau levels ?N in magnetic fields. Here we point out that the graphene Landau levels should have an interesting implication on the Landau-level laser proposed decades ago [H. Aoki, Appl. Phys. Lett. 48, 559 (1986)]. Having this in mind we have calculated the optical conductivity for graphene in magnetic fields,% with the linear-response theory, including the effect of disorder to show the following: (i) The unevenly spaced Landau levels do give rise to an interesting situation, where the N=0 Landau level stands alone for an appropriate level of disorder. This should help in realizing the population inversion (across N=0 and N>=1 here) necessary for lasing. (ii) The optical conductivity, which reflects the unevenly spaced Landau levels, has some peaks that increase with temperature. (iii) As for the relaxation processes, which are examined with an extention of the treatment for ordinary quantum Hall systems, graphene's peculiar cyclotron energy ?B along with its 2D nature favor the cyclotron emission over other relaxation processes.

  4. Ion cyclotron bands in VLF saucers

    NASA Technical Reports Server (NTRS)

    Maeda, Kaichi; Fung, Shing F.; Calvert, Wynne

    1990-01-01

    In the wideband VLF data obtained by the polar orbiting DE-1 satellite over the polar night ion trough region of the upper ionosphere, conspicuous frequency-band structures are found to occur both in absorption and emission, particularly associating with VLF saucers. The attenuation bands indicate that the ions of atomic hydrogen from the polar ionosphere are accelerated by the ac electric fields of VLF waves oscillating normal to the static magnetic field, analogous to a cyclotron accelerator. The observed frequencies of the cyclotron harmonics suggest that the acceleration is taking place in the layer below the satellite at a geocentric distance of less than about 1.5 earth radii. This example indicates the existence of upward propagating hiss at those altitudes inside the auroral zone. On the other hand, the frequency shifts of the emission bands are attributed to a combination of two different types of Doppler shift, one due to the orbital motion of the satellite and the other due to the upward motion of the medium at the emission source. This indicates the existence of an upward plasma flow at the source, with a velocity of the order of 20 km/s inside the saucer. The amount of this frequency shift decreases with increasing harmonic order, indicating a higher phase velocity for the electrostatic waves of higher harmonic order.

  5. Electron Cyclotron Current Drive by Bernstein Waves

    NASA Astrophysics Data System (ADS)

    Ram, A. K.; Decker, J.; Peysson, Y.

    2006-04-01

    The high-? plasmas in spherical tori (ST), like in NSTX, are overdense to the traditional X and O modes in the electron cyclotron range of frequencies (ECRF). However, in the same frequency range electron Bernstein waves (EBW) can propagate in ST plasmas and damp effectively on electrons at the Doppler-shifed electron cyclotron resonance or its harmonics. Since externally generated current is necessary for steady state operation and for controlling the current profile, we examine the role of EBWs in STs. We find that EBWs can generate plasma current by the Ohkawa scheme in the outer half of the plasma and the Fisch-Boozer scheme in the core of the plasma. The current drive efficiency is much higher with EBWs than with the traditional ECRF waves as the EBWs interact with more energetic electrons. We will discuss the properties of EBWs and their interaction with electrons for current drive. Results from two codes, one which solves the fully relativistic plasma dielectric tensor and the other which solves the drift kinetic equation for electrons, will also be presented.

  6. Cyclotron resonance heating systems for SST-1

    NASA Astrophysics Data System (ADS)

    Bora, D.; Kumar, Sunil; Singh, Raj; Sathyanarayana, K.; Kulkarni, S. V.; Mukherjee, A.; Shukla, B. K.; Singh, J. P.; Srinivas, Y. S. S.; Khilar, P.; Kushwah, M.; Kumar, Rajnish; Sugandhi, R.; Chattopadhyay, P.; Raghuraj, Singh; Jadav, H. M.; Kadia, B.; Singh, Manoj; Babu, Rajan; Jatin, P.; Agrajit, G.; Biswas, P.; Bhardwaj, A.; Rathi, D.; Siju, G.; Parmar, K.; Varia, A.; Dani, S.; Pragnesh, D.; Virani, C.; Patel, Harsida; Dharmesh, P.; Makwana, A. R.; Kirit, P.; Harsha, M.; Soni, J.; Yadav, V.; Bhattacharya, D. S.; Shmelev, M.; Belousov, V.; Kurbatov, V.; Belov, Yu.; Tai, E.

    2006-03-01

    RF systems in the ion cyclotron resonance frequency (ICRF) range and electron cyclotron resonance frequency (ECRF) range are in an advanced stage of commissioning, to carry out pre-ionization, breakdown, heating and current drive experiments on the steady-state superconducting tokamak SST-1. Initially the 1.5 MW continuous wave ICRF system would be used to heat the SST-1 plasma to 1.0 keV during a pulse length of 1000 s. For different heating scenarios at 1.5 and 3.0 T, a wide band of operating frequencies (20-92 MHz) is required. To meet this requirement two CW 1.5 MW rf generators are being developed in-house. A pressurized as well as vacuum transmission line and launcher for the SST-1-ICRF system has been commissioned and tested successfully. A gyrotron for the 82.6 GHz ECRF system has been tested for a 200 kW/1000 s operation on a water dummy load with 17% duty cycle. High power tests of the transmission line have been carried out and the burn pattern at the exit of transmission line shows a gaussian nature. Launchers used to focus and steer the microwave beam in plasma volume are characterized by a low power microwave source and tested for UHV compatibility. Long pulse operation has been made feasible by actively cooling both the systems. In this paper detailed test results and the present status of both the systems are reported.

  7. Status of the Milan superconducting cyclotron project

    SciTech Connect

    Acerbi, E.

    1983-08-01

    This paper presents an updated status report on the Superconducting Cyclotron, under construction at the University of Milan during the past two years, with funding chiefly provided by the Italian National Institute for Nuclear Physics. The cyclotron is designed for a K of 800 and a K /SUB FOC/ of 200 and thus yields maximum energies of 100 MeV/n for fully stripped light ions and 20 MeV/n for uranium and other heavy ions. The pole radius is 90 cm with three sectors having an average spiral constant of 1/45.7 rad/cm. The average magnetic field will span between 22 and 48 K Gauss with a corresponding R.F. frequency range between 15 and 48 MHz. The anticipated peak dee voltage is 100 KV with harmonic operation from h = 1 to h = 4. The operating modes include the use of an internal PIG source, injection from a 16 MV tandem, and axial injection from an external ion source. This paper presents the design parameters and outlines the progress made so far.

  8. 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.

  9. 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.

  10. Collective cyclotron motion of the relativistic plasma in graphene Markus Mller and Subir Sachdev

    E-print Network

    Müller, Markus

    Collective cyclotron motion of the relativistic plasma in graphene Markus Müller and Subir Sachdev cyclotron motion with a temperature-dependent relativistic cyclotron frequency proportional to the net charge density of the Dirac plasma. In contrast to the undamped cyclotron pole in Galilean

  11. Picosecond time-resolved cyclotron resonance in semiconductors A. H. Chin, and A. P. Mitchell

    E-print Network

    Kono, Junichiro

    Picosecond time-resolved cyclotron resonance in semiconductors J. Kono,a) A. H. Chin, and A. P FIR absorption as a function of magnetic field, we performed time-resolved cyclotron resonance.g., inter-Landau level transitions cyclotron reso- nance . Since cyclotron resonance CR is a powerful FIR

  12. Relativistic cyclotron resonance condition as applied to Type II interplanetary radio emission

    E-print Network

    California at Berkeley, University of

    Relativistic cyclotron resonance condition as applied to Type II interplanetary radio emission W. M to couple directly to the o-mode radio branch via the relativistic cyclotron harmonic resonance interaction not exactly at) the cyclotron harmonics, mfc, where m is the cyclotron harmonic number. We compare the details

  13. Spin Separation in Cyclotron Motion L. P. Rokhinson* and V. Larkina

    E-print Network

    Rokhinson, Leonid

    Spin Separation in Cyclotron Motion L. P. Rokhinson* and V. Larkina Department of Physics, Purdue in the same direction, and, correspondingly, different cyclotron orbits in a weak magnetic field. Two point character- istic for cyclotron motion. Then, charge carriers move along the cyclotron orbit with spin

  14. Wave dispersion near cyclotron resonance in pulsar plasmas D. B. Melrose* and Q. Luo

    E-print Network

    Melrose, Don

    Wave dispersion near cyclotron resonance in pulsar plasmas D. B. Melrose* and Q. Luo School below the cyclotron frequency and must propagate through the cyclotron resonance region where they are affected by the reso- nance. Wave dispersion near the cyclotron resonance is discussed in the formalism

  15. Power requirements for electron cyclotron current drive and ion cyclotron resonance heating for sawtooth control in ITER

    NASA Astrophysics Data System (ADS)

    Chapman, I. T.; Graves, J. P.; Sauter, O.; Zucca, C.; Asunta, O.; Buttery, R. J.; Coda, S.; Goodman, T.; Igochine, V.; Johnson, T.; Jucker, M.; La Haye, R. J.; Lennholm, M.; Contributors, JET-EFDA

    2013-06-01

    13 MW of electron cyclotron current drive (ECCD) power deposited inside the q = 1 surface is likely to reduce the sawtooth period in ITER baseline scenario below the level empirically predicted to trigger neoclassical tearing modes (NTMs). However, since the ECCD control scheme is solely predicated upon changing the local magnetic shear, it is prudent to plan to use a complementary scheme which directly decreases the potential energy of the kink mode in order to reduce the sawtooth period. In the event that the natural sawtooth period is longer than expected, due to enhanced ? particle stabilization for instance, this ancillary sawtooth control can be provided from >10MW of ion cyclotron resonance heating (ICRH) power with a resonance just inside the q = 1 surface. Both ECCD and ICRH control schemes would benefit greatly from active feedback of the deposition with respect to the rational surface. If the q = 1 surface can be maintained closer to the magnetic axis, the efficacy of ECCD and ICRH schemes significantly increases, the negative effect on the fusion gain is reduced, and off-axis negative-ion neutral beam injection (NNBI) can also be considered for sawtooth control. Consequently, schemes to reduce the q = 1 radius are highly desirable, such as early heating to delay the current penetration and, of course, active sawtooth destabilization to mediate small frequent sawteeth and retain a small q = 1 radius. Finally, there remains a residual risk that the ECCD + ICRH control actuators cannot keep the sawtooth period below the threshold for triggering NTMs (since this is derived only from empirical scaling and the control modelling has numerous caveats). If this is the case, a secondary control scheme of sawtooth stabilization via ECCD + ICRH + NNBI, interspersed with deliberate triggering of a crash through auxiliary power reduction and simultaneous pre-emptive NTM control by off-axis ECCD has been considered, permitting long transient periods with high fusion gain. The power requirements for the necessary degree of sawtooth control using either destabilization or stabilization schemes are expected to be within the specification of anticipated ICRH and ECRH heating in ITER, provided the requisite power can be dedicated to sawtooth control.

  16. 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.

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

    PubMed

    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. PMID:24517753

  18. 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.

  19. Evidence for cyclotron maser emission from the sun and stars

    NASA Technical Reports Server (NTRS)

    Dulk, G. A.; Winglee, R. M.

    1987-01-01

    Recent observational and theoretical work on cyclotron maser instability is reviewed, with emphasis on the similarities between microwave spike bursts from the sun and bursts from stars and planets. Results on particle-in-cell simulations are discussed, and it is suggested that such studies may provide further information on the amount and efficiency of energy transfer by the maser radiation. Observational tests of the cyclotron maser theory are considered, in addition to the role of the cyclotron maser as an energy transport mechanism in solar flares.

  20. 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.

  1. Decommissioning of a hot laboratory and cyclotron complex to Green Field

    SciTech Connect

    Loughborough, D.; Hamblin, C.; Asquith, J.

    1995-01-01

    This article describes the decommissioning of several major facilities and two small nuclear reactors at AEA Technology`s Harwell Laboratory in England. Building 540.2 which included the Variable Energy Cyclotron (VEC) and hot laboratory facilities was to be the first to complet a treturn to a `green-field` site, scheduled in June 1994. Topics covered in this article include the following: the VEC; The Hot cells; options study; decommissioning plan; setting a strategy; the ARTISAN Manipulator system; decommissioning methodology; timescales; experiences during decommissioning; methodology; schedule; civil demolition. 6 figs.

  2. Ohm's law at strong coupling: S duality and the cyclotron resonance

    SciTech Connect

    Hartnoll, Sean A. [KITP, University of California, Santa Barbara, California 93106-4030 (United States); Herzog, Christopher P. [Physics Department, University of Washington, Seattle, Washington 98195-1560 (United States)

    2007-11-15

    We calculate the electrical and thermal conductivities and the thermoelectric coefficient of a class of strongly interacting 2+1-dimensional conformal field theories with anti-de Sitter space duals. We obtain these transport coefficients as a function of charge density, background magnetic field, temperature, and frequency. We show that the thermal conductivity and thermoelectric coefficient are determined by the electrical conductivity alone. At small frequency, in the hydrodynamic limit, we are able to provide a number of analytic formulas for the electrical conductivity. A dominant feature of the conductivity is the presence of a cyclotron pole. We show how bulk electromagnetic duality acts on the transport coefficients.

  3. Ohm's Law at strong coupling: S duality and the cyclotron resonance

    E-print Network

    Sean A. Hartnoll; Christopher P. Herzog

    2007-10-18

    We calculate the electrical and thermal conductivities and the thermoelectric coefficient of a class of strongly interacting 2+1 dimensional conformal field theories with anti-de Sitter space duals. We obtain these transport coefficients as a function of charge density, background magnetic field, temperature and frequency. We show that the thermal conductivity and thermoelectric coefficient are determined by the electrical conductivity alone. At small frequency, in the hydrodynamic limit, we are able to provide a number of analytic formulae for the electrical conductivity. A dominant feature of the conductivity is the presence of a cyclotron pole. We show how bulk electromagnetic duality acts on the transport coefficients.

  4. Texas A&M 14.5 and 6.4 GHz electron cyclotron resonance ion sources

    Microsoft Academic Search

    D. P. May; F. P. Abegglen; G. J. Derrig; R. S. Olsen

    2006-01-01

    The plasma chamber of the Texas A&M 14.5 GHz electron cyclotron resonance (ECR) ion source ECR2 has been redesigned recently. Small-diameter (1.8 mm), water-carrying copper tubes are interposed between the Nb-Fe-B permanent magnets and the aluminum plasma-chamber wall. This design allows for more protection of the hexapole via water cooling than the previous design and also eliminates all of the

  5. Texas A&M 14.5 and 6.4 GHz electron cyclotron resonance ion sources

    Microsoft Academic Search

    D. P. May; F. P. Abegglen; G. J. Derrig; R. S. Olsen

    2006-01-01

    The plasma chamber of the Texas A&M 14.5 GHz electron cyclotron resonance (ECR) ion source ECR2 has been redesigned recently. Small-diameter (1.8 mm), water-carrying copper tubes are interposed between the Nb–Fe–B permanent magnets and the aluminum plasma-chamber wall. This design allows for more protection of the hexapole via water cooling than the previous design and also eliminates all of the

  6. Medications: Using Them Safely

    MedlinePLUS

    ... to see if chilling the medicine is safe. Mixing the medicine with a small amount of liquid or soft food (such as applesauce or yogurt) may make it ... the medication's effectiveness will not be altered by mixing it with food or ... using a syringe, try squirting the medicine (a little bit at a time) on the ...

  7. Current Profile Modification with Electron Cyclotron Current Drive

    NASA Astrophysics Data System (ADS)

    Luce, T. C.

    1998-11-01

    Generation of localized current by electron cyclotron (EC) waves offers the possibility of steady-state current sustainment, active current profile control, and instability suppression. This work represents the first proof-of-principle determination of both on-axis and off-axis current drive derived from local measurements of the internal magnetic fields. The EC waves are generated by two 110 GHz gyrotrons (0.9 MW and 0.8 MW for 1 s pulses) and are transmitted to the plasma by overmoded evacuated transmission line. The deposition can be varied by changing the poloidal angle of the final launching mirror or by changing the toroidal magnetic field. For central aiming with oblique launch, electron cyclotron current drive (ECCD) up to 100 kA has been driven with 1.2 MW of EC power. The current drive figure of merit has the expected linear dependence on electron temperature and is comparable to that in previous experiments on DIII--D for ECCD and for fast wave current drive. During the central ECCD, the loop voltage on axis becomes negative, indicating that the driven current density exceeds the Ohmic current density before the ECCD is applied. The internal inductance rises and the central safety factor q(0) falls compared to the case without current drive, as expected. When the EC deposition is moved off-axis to ?=0.4, the total noninductive current rises by up to 100 kA compared to a discharge without ECCD, and the current profile broadens. The increase in noninductive current is both EC current drive and neutral beam current drive (NBCD) enhanced by the elevated temperature, but the broadening of the current profile indicates the bulk of the current is EC-driven current. The off-axis EC-driven current exceeds the current predicted by theoretical modeling, which is small due to the Ohkawa effect. The difference from linear theory is qualitatively consistent with previous calculations of electric field enhancement of ECCD. A scan of the major radius of the deposition at fixed minor radius (?=0.4) indicates substantially more current is driven with the resonance on the high field side of the axis, as expected from consideration of the local fraction of trapped particles. The magnitude of the effects is being compared with Fokker-Planck code calculations.

  8. Cyclotron maser radiation from inhomogeneous plasmas

    SciTech Connect

    Cairns, R. A.; Vorgul, I. [School of Mathematics and Statistics, University of St. Andrews, St. Andrews, Fife KY16 9SS (United Kingdom); Bingham, R. [STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Ronald, K.; Speirs, D. C.; McConville, S. L.; Gillespie, K. M.; Bryson, R.; Phelps, A. D. R.; Cross, A. W.; Roberston, C. W.; Whyte, C. G.; He, W. [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Kellett, B. J. [STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom)

    2011-02-15

    Cyclotron maser instabilities are important in space, astrophysical, and laboratory plasmas. While extensive work has been done on these instabilities, most of it deals with homogeneous plasmas with uniform magnetic fields while in practice, of course, the systems are generally inhomogeneous. Here we expand on our previous work [R. A. Cairns, I. Vorgul, and R. Bingham, Phys. Rev. Lett. 101, 215003 (2008)] in which we showed that localized regions of instability can exist in an inhomogeneous plasma and that the way in which waves propagate away from this region is not necessarily obvious from the homogeneous plasma dispersion relation. While we consider only a simple ring distribution in velocity space, because of its tractability, the ideas may point toward understanding the behavior in the presence of more realistic distributions. The main object of the present work is to move away from consideration of the local dispersion relation and show how global growing eigenmodes can be constructed.

  9. 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.

  10. High-Resolution Ion Cyclotron Mobility Spectrometry

    PubMed Central

    Merenbloom, Samuel I.; Glaskin, Rebecca S.; Henson, Zachary B.; Clemmer, David E.

    2009-01-01

    A novel ion mobility spectrometry instrument incorporating a cyclotron geometry drift tube is presented. The drift tube consists of eight regions, four curved drift tubes and four ion funnels. Packets of ions are propagated around the drift tube by changing the drift field at a frequency that is resonant with the ion’s drift time through each region. The approach trims each packet of ions as it leaves and enters each new region. An electrostatic gate allows ions to be kept in the drift tube for numerous cycles, increasing the ability to resolve specified ions. We demonstrate the approach by isolating the [M+2H]2+ or [M+3H]3+ charge state of substance P as well as individual trisaccharide isomers from a mixture of melezitose and raffinose. Resolving powers in excess of 300 are obtainable with this approach. PMID:19143495

  11. Cyclotron emission effect on CMB spectral distortions

    E-print Network

    Carlo Burigana; Andrea Zizzo

    2006-01-12

    We investigated the role of the cyclotron emission (CE) associated to cosmic magnetic fields (MF) on the evolution of cosmic microwave background (CMB) spectral distortions. We computed the photon and energy injection rates by including spontaneous and stimulated emission and absorption. These CE rates have been compared with those of bremsstrahlung (BR) and double Compton scattering (DC), for realistic CMB distorted spectra at various cosmic epochs. For reasonable MF strengths we found that the CE contribution to the evolution of the CMB spectrum is much smaller than the BR and DC contributions. The constraints on the energy exchanges at various redshifts can be then derived, under quite general assumptions, by considering only Compton scattering (CS), BR, and DC, other than the considered dissipation process. Upper limits to the CMB polarization degree induced by CE have been estimated.

  12. Electron-cyclotron-resonance (ECR) plasma acceleration

    NASA Technical Reports Server (NTRS)

    Sercel, Joel C.

    1987-01-01

    A research effort directed at analytically and experimentally investigating electron-cyclotron-resonance (ECR) plasma acceleration is outlined. In addition, relevant past research is reviewed. Also, the prospects for application of ECR plasma acceleration to spacecraft propulsion are described. It is shown that previously unexplained losses in converting microwave power to directed kinetic power via ECR plasma acceleration can be understood in terms of diffusion of energized plasma to the physical walls of the accelerator. It is also argued that line radiation losses due to electron-ion and electron-atom inelastic collisions should be less than estimated in past research. Based on this new understanding, the expectation now exists that very efficient ECR plasma accelerators can be designed for application to high-specific-impulse spacecraft propulsion.

  13. 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.

  14. Superconducting cyclotron and its vacuum system

    NASA Astrophysics Data System (ADS)

    Sur, A.; Bhandari, R. K.

    2008-05-01

    A large superconducting cyclotron is under construction at this Centre and will be used to accelerate heavy ion beams to energy up to 80 MeV/A for light heavy ions and about 10 MeV/A for medium mass heavy ions. The vacuum system for this accelerator has several different aspects. The main acceleration chamber will be evacuated to a level of about 10-7 torr using both turbo molecular pumps and specially designed cryopanels. The surfaces exposed to this 'vacuum' are mostly made of OFE copper. The cryogenic transfer lines, to cool the cryopanels, are of several meters in length and they pass through RF resonators extending below the magnet. The cryostat that will house the superconducting coils has an annular vacuum chamber, which is evacuated to a level of approximately 10-5 torr using a turbo molecular pump. Cryopumping action starts once the coils are cooled to low temperatures. A differential pumping is provided below the RF liner that encloses the pole tip of the main magnet. The space that is pumped in this case contains epoxy-potted trim coils wound around the pole tips. Crucial interlocks are provided between the differential vacuum and the acceleration chamber vacuum to avoid distortion of the RF liner, which is made of thin copper sheets. The other important vacuum system provides thermal insulation for the liquid helium transfer lines. In this paper a brief description of the superconducting cyclotron will be given. Details of various vacuum aspects of the accelerator and the logistics of their operation will be presented. Introduction of some of the improved equipment now available and improved techniques are also discussed.

  15. The NSCL cyclotron gas stopper - Under construction

    NASA Astrophysics Data System (ADS)

    Schwarz, S.; Bollen, G.; Brodeur, M.; Chouhan, S. S.; DeKamp, J.; Gehring, A. E.; Joshi, N. S.; Magsig, C.; Morrissey, D. J.; Ringle, R.; Ottarson, J.; Zeller, A. F.

    2013-12-01

    Rare isotopes are produced at the NSCL by projectile fragmentation at energies on the order of 100 MeV/u for a wide range of research. In order to provide these exotic ions to low-energy high precision experiments such as the Penning-trap mass spectrometer LEBIT and the collinear laser spectroscopy setup, or to the NSCL's re-accelerator (ReA), the beam must be slowed down into the eV range by solid degraders and interaction with buffer gas. A novel gas-filled reverse cyclotron is currently under construction by the NSCL and will complement a recently installed linear gas-filled cell. The new device is based on a 2.6 T maximum-field cyclotron-type three-sectored magnet to confine the injected beam while it is slowed down in ?100 mbar of high-purity helium gas, cooled to liquid-nitrogen temperature. Once thermalized, the beam is transported to the center of the device by a novel RF-carpet system, extracted along the symmetry axis and accelerated to a few tens of keV of energy for delivery to the users. The device has been characterized in numerous simulations with full 3D models of its magnetic field. The beam transport has been modeled from the fragment separator to the point where they reach thermal energies. The simulations indicate that very efficient stopping and fast extraction will be possible even for light and medium-mass ions, which are difficult to efficiently thermalize in linear gas cells. Construction of the device is well underway and initial tests are planned for later this year. The design and the predicted performance of the machine is discussed and its construction status is given.

  16. 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 satellite and ground-based data is needed to solve this very intriguing problem.

  17. 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 of modern satellite and ground-based data is needed to solve this very intriguing problem.

  18. Resonant cyclotron scattering in magnetars' emission

    E-print Network

    Nanda Rea; Silvia Zane; Roberto Turolla; Maxim Lyutikov; Diego Gotz

    2008-06-19

    (Abridged) We present a systematic fit of a model of resonant cyclotron scattering (RCS) to the X-ray data of ten magnetars, including canonical and transient anomalous X-ray pulsars (AXPs), and soft gamma repeaters (SGRs). In this scenario, non-thermal magnetar spectra in the soft X-rays (i.e. below ~10 keV) result from resonant cyclotron scattering of the thermal surface emission by hot magnetospheric plasma. We find that this model can successfully account for the soft X-ray emission of magnetars, while using the same number of free parameters than the commonly used empirical blackbody plus power-law model. However, while the RCS model can alone reproduce the soft X-ray spectra of AXPs, the much harder spectra of SGRs below ~10 keV, requires the addition of a power-law component (the latter being the same component responsible for their hard X-ray emission). Although this model in its present form does not explain the hard X-ray emission of a few of these sources, we took this further component into account in our modeling not to overlook their contribution in the ~4-10 keV band. We find that the entire class of sources is characterized by magnetospheric plasma with a density which, at resonant radius, is about 3 orders of magnitudes higher than n_{GJ}, the Goldreich-Julian electron density. The inferred values of the intervening hydrogen column densities, are also in better agreement with more recent estimates inferred from the fit of single X-ray edges. For the entire sample of observations, we find indications for a correlation between the scattering depth and the electron thermal velocity, and the field strength. Moreover, in most transient anomalous X-ray pulsars the outburst state is characterized by a relatively high surface temperature which cools down during the decay.

  19. Medical Assistants

    NSDL National Science Digital Library

    For a concise summary of the medical assistant profession the Medical Assistants entry in the Bureau of Labor Statistics' Occupational Outlook Handbook is must read. The site covers topics ranging from the nature of the profession, working conditions, earnings, and more. The section on training, qualifications and advancement will be of special interest to medical assistant faculty and students. The section on sources of addition information will also be a good launching point for anyone seeking additional online resources.

  20. Design Study Of Cyclotron Magnet With Permanent Magnet

    SciTech Connect

    Kim, Hyun Wook [Lab. Of Accelerator and Medical Engineering, SungKyunKwan University, Cheoncheon-dong, Jangan-gu, Suwon Gyeonggi-do 440-746 (Korea, Republic of); Chai, Jong Seo [Lab. Of Accelerator and Medical Engineering, SungKyunKwan University, Cheoncheon-dong, Jangan-gu, Suwon Gyeonggi-do 440-746 (Korea, Republic of); Department of Energy Science, SungKyunKwan University, Cheoncheon-dong, Jangan-gu, Suwon Gyeonggi-do 440-746 (Korea, Republic of)

    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.

  1. Multiple frequency electron cyclotron heating for the Levitated Dipole Experiment

    E-print Network

    Mahar, Scott B

    2005-01-01

    The use of multiple frequencies of electron cyclotron resonance heating (ECRH) in the Levitated Dipole Experiment (LDX) is an important tool that will tailor the plasma profiles. Initial LDX plasmas have been created using ...

  2. Development Plans - the Texas A&m Cyclotron Institute

    Microsoft Academic Search

    F. Abegglen; A. Azhari; G. Chubaryan; H. Clark; G. Derrig; C. A. Gagliardi; J. C. Hardy; G. Kim; D. May; M. Murray; J. B. Natowitz; R. P. Schmitt; G. Souliotis; R. E. Tribble; R. Wada; R. L. Watson; D. H. Youngblood; S. J. Yennello

    2003-01-01

    A facility upgrade for the Texas A&M University Cyclotron Institute would significantly extend our research capabilities as a stable beam facility with extended rare beam capabilities. This would be achieved by re-activating our 88\\

  3. Collective cyclotron motion of the relativistic plasma in graphene

    E-print Network

    Markus Mueller; Subir Sachdev

    2008-09-19

    We present a theory of the finite temperature thermo-electric response functions of graphene, in the hydrodynamic regime induced by electron-electron collisions. In moderate magnetic fields, the Dirac particles undergo a collective cyclotron motion with a temperature-dependent relativistic cyclotron frequency proportional to the net charge density of the Dirac plasma. In contrast to the undamped cyclotron pole in Galilean-invariant systems (Kohn's theorem), here there is a finite damping induced by collisions between the counter-propagating particles and holes. This cyclotron motion shows up as a damped pole in the frequency dependent conductivities, and should be readily detectable in microwave measurements at room temperature. We also discuss the large Nernst effect to be expected in graphene.

  4. Single electron detection and spectroscopy via relativistic cyclotron radiation

    E-print Network

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

    2014-08-22

    It has been understood since 1897 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. Here we demonstrate single-electron detection in a novel radiofrequency spec- trometer. 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 elec- tron 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.

  5. Dispersion relation of electromagnetic ion cyclotron waves using Cluster observations

    E-print Network

    Pakhotin, I. P.

    Multi-point wave observations on Cluster spacecraft are used to infer the dispersion relation of electromagnetic ion cyclotron (EMIC) waves. In this study we use a phase differencing method and observations from STAFF and ...

  6. 6D Muon Ionization Cooling with an Inverse Cyclotron

    SciTech Connect

    Summers, D. J.; Bracker, S. B.; Cremaldi, L. M.; Godang, R. [Dept. of Physics and Astronomy, University of Mississippi-Oxford, University, MS 38677 (United States); Palmer, R. B. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2006-03-20

    A large admittance sector cyclotron filled with LiH wedges surrounded by helium or hydrogen gas is explored. Muons are cooled as they spiral adiabatically into a central swarm. As momentum approaches zero, the momentum spread also approaches zero. Long bunch trains coalesce. Energy loss is used to inject the muons into the outer rim of the cyclotron. The density of material in the cyclotron decreases adiabatically with radius. The sector cyclotron magnetic fields are transformed into an azimuthally symmetric magnetic bottle in the center. Helium gas is used to inhibit muonium formation by positive muons. Deuterium gas is used to allow captured negative muons to escape via the muon catalyzed fusion process. The presence of ionized gas in the center may automatically neutralize space charge. When a bunch train has coalesced into a central swarm, it is ejected axially with an electric kicker pulse.

  7. Effective dose to immuno-PET patients due to metastable impurities in cyclotron produced zirconium-89

    NASA Astrophysics Data System (ADS)

    Alfuraih, Abdulrahman; Alzimami, Khalid; Ma, Andy K.; Alghamdi, Ali; Al Jammaz, Ibrahim

    2014-11-01

    Immuno-PET is a nuclear medicine technique that combines positron emission tommography (PET) with radio-labeled monoclonal antibodies (mAbs) for tumor characterization and therapy. Zirconium-89 (89Zr) is an emerging radionuclide for immuno-PET imaging. Its long half-life (78.4 h) gives ample time for the production, the administering and the patient uptake of the tagged radiopharmaceutical. Furthermore, the nuclides will remain in the tumor cells after the mAbs are catabolized so that time series studies are possible without incurring further administration of radiopharmarceuticals. 89Zr can be produced in medical cyclotrons by bombarding an yttrium-89 (89Y) target with a proton beam through the 89Y(p,n)89Zr reaction. In this study, we estimated the effective dose to the head and neck cancer patients undergoing 89Zr-based immune-PET procedures. The production of 89Zr and the impurities from proton irradiation of the 89Y target in a cyclotron was calculated with the Monte Carlo code MCNPX and the nuclear reaction code TALYS. The cumulated activities of the Zr isotopes were derived from real patient data in literature and the effective doses were estimated using the MIRD specific absorbed fraction formalism. The estimated effective dose from 89Zr is 0.5±0.2 mSv/MBq. The highest organ dose is 1.8±0.2 mSv/MBq in the liver. These values are in agreement with those reported in literature. The effective dose from 89mZr is about 0.2-0.3% of the 89Zr dose in the worst case. Since the ratio of 89mZr to 89Zr depends on the cooling time as well as the irradiation details, contaminant dose estimation is an important aspect in optimizing the cyclotron irradiation geometry, energy and time.

  8. Comparison between californium and cyclotron heavy ion tests

    NASA Astrophysics Data System (ADS)

    Velazco, Raoul; Provost-Grellier, Antoine

    Experimental equipment which performs heavy ion tests for programmable integrated circuits is presented. This equipment is used along with two different means of heavy ion simulator to perform Single Event Upset (SEU) tests on representative circuits: A dedicated Cf 252 fission decay source and a cyclotron. The validity of using californium source to simulate high LET particles is questioned by the discrepancies observed between Cf 252 and cyclotron results.

  9. The electron–cyclotron maser for astrophysical application

    Microsoft Academic Search

    Rudolf A. Treumann

    2006-01-01

    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

  10. The electron-cyclotron maser for astrophysical application

    Microsoft Academic Search

    Rudolf A. Treumann

    2006-01-01

    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

  11. Magnetosphere cyclotron maser: Backward wave oscillator generation regime

    Microsoft Academic Search

    V. Y. Trakhtengerts

    1995-01-01

    A new generation regime of the magnetosphere cyclotron maser is considered, based on phase coherence effects in wave-particle systems with step-like deformations of electron velocity distribution functions. Such deformations appear during cyclotron interactions of noise-like whistler wave emissions and energetic electrons at the boundaries between resonant and nonresonant particles. The new regime is similar to the backward wave oscillator in

  12. Mirror and ion cyclotron anisotropy instabilities in the magnetosheath

    NASA Technical Reports Server (NTRS)

    Mckean, M. E.; Winske, D.; Gary, S. P.

    1992-01-01

    The kinetic properties of the ion cyclotron anisotropy and the mirror instabilities are investigated using one-dimensional hybrid simulations. It is found that, for moderate values of the ion beta and the proton temperature anisotropy, the two instabilities produce similar levels of turbulence. For high values of beta or temperature anisotropy, the ion cyclotron instability produces higher fluctuation levels of turbulence than does the mirror instability.

  13. The contribution of ion-cyclotron waves to electron heating and SAR-arc excitation near the storm-time plasmapause. [Stable Auroral Red arc

    NASA Technical Reports Server (NTRS)

    Thorne, Richard M.; Horne, Richard B.

    1992-01-01

    The potential role of ion-cyclotron waves in the electron heating process has been studied, using the HOTRAY code. It is demonstrated that ion-cyclotron waves can play an important role in both the energy transfer to plasmaspheric electrons and the subsequent downward heat conduction to SAR arc altitudes. In particular, such waves can experience enhanced path integrated amplification along the steep plasmapause density gradient. The latter tends to keep the wave normal angle small on several successive bounces across the equator, thus allowing cyclotron-resonant amplification leading to a total gain of up to 20 e-foldings. When the wave propagation vector becomes highly oblique, absorption occurs during Landau resonance with thermal plasmaspheric electrons, increasing the electron temperature in the direction parallel to the ambient field and leading directly to heat conduction into ionosphere.

  14. Twelve million resolving power on 4.7 T Fourier transform ion cyclotron resonance instrument with dynamically harmonized cell-observation of fine structure in peptide mass spectra.

    PubMed

    Popov, Igor A; Nagornov, Konstantin; Vladimirov, Gleb N; Kostyukevich, Yury I; Nikolaev, Eugene N

    2014-05-01

    Resolving power of about 12,000 000 at m/z 675 has been achieved on low field homogeneity 4.7 T magnet using a dynamically harmonized Fourier transform ion cyclotron resonance (FT ICR) cell. Mass spectra of the fine structure of the isotopic distribution of a peptide were obtained and strong discrimination of small intensity peaks was observed in case of resonance excitation of the ions of the whole isotopic cluster to the same cyclotron radius. The absence of some peaks from the mass spectra of the fine structure was explained basing on results of computer simulations showing strong ion cloud interactions, which cause the coalescence of peaks with m/z close to that of the highest magnitude peak. The way to prevent peak discrimination is to excite ion clouds of different m/z to different cyclotron radii, which was demonstrated and investigated both experimentally and by computer simulations. PMID:24604470

  15. Accelerator science in medical physics

    PubMed Central

    Peach, K; Wilson, P; Jones, B

    2011-01-01

    The use of cyclotrons and synchrotrons to accelerate charged particles in hospital settings for the purpose of cancer therapy is increasing. Consequently, there is a growing demand from medical physicists, radiographers, physicians and oncologists for articles that explain the basic physical concepts of these technologies. There are unique advantages and disadvantages to all methods of acceleration. Several promising alternative methods of accelerating particles also have to be considered since they will become increasingly available with time; however, there are still many technical problems with these that require solving. This article serves as an introduction to this complex area of physics, and will be of benefit to those engaged in cancer therapy, or who intend to acquire such technologies in the future. PMID:22374548

  16. Spin-Dependent Cyclotron Decay Rates in Strong Magnetic Fields

    E-print Network

    Matthew G. Baring; Peter L. Gonthier; Alice K. Harding

    2005-05-16

    Cyclotron decay and absorption rates have been well studied in the literature, focusing primarily on spectral, angular and polarization dependence. Astrophysical applications usually do not require retention of information on the electron spin state, and these are normally averaged in obtaining the requisite rates. In magnetic fields, higher order quantum processes such as Compton scattering become resonant at the cyclotron frequency and its harmonics, with the resonances being formally divergent. Such divergences are usually eliminated by accounting for the finite lifetimes of excited Landau states. This practice requires the use of spin-dependent cyclotron rates in order to obtain accurate determinations of process rates very near cyclotronic resonances, the phase space domain most relevant for certain applications to pulsar models. This paper develops previous results in the literature to obtain compact analytic expressions for cyclotron decay rates/widths in terms of a series of Legendre functions of the second kind; these expressions can be expediently used in astrophysical models. The rates are derived using two popular eigenstate formalisms, namely that due to Sokolov and Ternov, and that due to Johnson and Lippmann. These constitute two sets of eigenfunctions of the Dirac equation that diagonalize different operators, and accordingly yield different spin-dependent cyclotron rates. This paper illustrates the attractive Lorentz transformation characteristics of the Sokolov and Ternov formulation, which is another reason why it is preferable when electron spin information must be explicitly retained.

  17. Status and development of the Kazakhstan isochronous cyclotron

    NASA Astrophysics Data System (ADS)

    Arzumanov, A.; Batischev, V.; Borissenko, A.; Gorkovets, M.; Koptev, V.; Lyssukhin, S.; Mulgin, S.; Popov, Yu.; Zhdanov, S.

    2001-12-01

    A report is presented on the status of the cyclotron in Almaty at present time. In spite of sharp curtailment of government-funded basic research program the cyclotron still remains as multipurpose accelerator facility and is being used for fundamental research and application in different fields of applied science. During last years some cyclotron systems were upgraded and some were designed anew. The system for on-line precise ion beam energy measurement using time-of-flight method was designed and constructed. Inductive pick-up electrodes are integrated into beam transport channel and are located at the distance of 10 m from each other. Average beam energy determination is performed with the accuracy about 0.1%. This system allows to analyze ion beam parameters in pulse-mode of cyclotron operation with macro duty factor in the range of 2-50. In connection with development of cyclotron based radioisotope production and necessity of irradiation of toxic materials and loose and smelted powders with low heat conductivity circular beam scanning system was designed and installed. Transversal rotating magnetic field is generated by stator of usual electro-motor. The scanner allows to form predictable beam power density distribution on the target surface and obtain rather uniform irradiation fields. Cyclotron based neutron source with Be target for research on radioecology and neutron dosimetry was constructed and is located at one of the external beam transportation channel. Parameters of the system and examples of its application are presented.

  18. French Army Medical Services in the mid-nineteenth century: a medical history of the French Crimean expedition

    E-print Network

    Harbison, Burton Earl

    1987-01-01

    . MEDICAL TECHNOLOGY IN THE NINETEENTH CENTURY. Surgery. The New Small Arms Military Medicine in France. THE FRENCH MEDICAL SERVICE IN 1854. The Algerian Experience. French Hospitals The British System . Non-Medical Considerations MEDICAL HISTORY... OF THE FRENCH CRIMEAN EXPEDITION. The First Winter The Second Winter. ANALYSIS. Medical Technology . The Economy. Shortages Among Medical Personnel. The Soldiers and Leaders Operating Procedure. Subordination of the Medical Service The War at Home...

  19. Electromagnetic cyclotron waves near the proton cyclotron frequency in the solar wind

    NASA Astrophysics Data System (ADS)

    Jian, Lan K.; Boardsen, Scott; Moya, Pablo; Stevens, Michael; Alexander, Robert; Vinas, Adolfo

    2015-04-01

    Strong narrow-band electromagnetic waves around the proton cyclotron frequency (fpc) have been found sporadically in the solar wind from 0.3 to 0.7 AU during MESSENGER spacecraft’s cruise phase. These waves are transverse and circularly polarized, and they propagate in directions quasi-parallel to the magnetic field. The wave power decreases quadratically with heliocentric distance, faster than the trend if assuming the conservation of Poynting flux for wave packets, suggesting there is energy dissipation from the waves, which could contribute to the heating and acceleration of solar wind plasma. Although the wave frequency is a few times of fpc in the spacecraft frame, it is a fraction of fpc in the solar wind plasma frame after removing the Doppler shift effect. In this frequency range, the waves can be left-hand (LH) polarized ion cyclotron waves or right-hand (RH) polarized magnetosonic waves. Because the waves are LH or RH polarized in the spacecraft frame with otherwise nearly identical characteristics, they could be due to Doppler shift of a same type of waves or a mixture of waves with intrinsically different polarizations. Through the assistance of audification, we have studied the long-lasting wave events in 2005 using high-cadence magnetic field data from the Wind mission. Statistically, in contrast with general solar wind, the protons at these waves are distributed closer to the proton instability thresholds, while the alpha particles at these waves are distributed further away from the alpha instability thresholds. For selected events of extensive waves, the ion distribution is analyzed in detail. A mixture of temperature anisotropies for core protons, beam protons, and alpha particles, as well as proton beam drift are often found in such events. We conduct linear wave dispersion analysis using these ion moments to examine whether these waves can be explained by the local generation of kinetic instabilities such as the LH ion cyclotron, the RH firehose, and the RH ion beam instability.

  20. Influence of wall impedance and self-fields on the cyclotron maser instability

    SciTech Connect

    Khalilzadeh, Elnaz; Maraghechi, Behrouz [Department of Physics, Amirkabir University of Technology, P. O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Chakhmachi, Amir [Department of Physics, Amirkabir University of Technology, P. O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Plasma Physics and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, P.O. Box 14155-1339 (Iran, Islamic Republic of)

    2009-09-01

    The compound influence of wall impedance and self-fields on the cyclotron maser instability is investigated for a hollow electron beam. A stability analysis is carried out using the linearized Vlasov-Maxwell equations, under the assumption that the beam thickness is small compared to the beam radius. A dispersion relation is derived and solved numerically to study the effects of the wall impedance and self-fields on the cyclotron maser instability. These effects lead to the elliptical motion of the equilibrium configuration. The growth rate decreases due to the wall resistivity and self-fields. It has been shown that the interaction between the self-field and impedance effects is in the lower reduction in the growth rate when they are both present compared to their separate effects added together. The instability bandwidth increases due to the wall impedance and decreases due to the self fields. In the presence of self-fields, a very small increase in the wall impedance causes an increase in the instability bandwidth. This shows that the widening effect of the bandwidth due to the wall impedance is dominant and prevails over the narrowing effect of the self-field.

  1. Texas A and M 14.5 and 6.4 GHz electron cyclotron resonance ion sources

    SciTech Connect

    May, D.P.; Abegglen, F.P.; Derrig, G.J.; Olsen, R.S. [Cyclotron Institute, Texas A and M University, College Station, Texas 77845 (United States)

    2006-03-15

    The plasma chamber of the Texas A and M 14.5 GHz electron cyclotron resonance (ECR) ion source ECR2 has been redesigned recently. Small-diameter (1.8 mm), water-carrying copper tubes are interposed between the Nb-Fe-B permanent magnets and the aluminum plasma-chamber wall. This design allows for more protection of the hexapole via water cooling than the previous design and also eliminates all of the troublesome water-to-vacuum seals of the previous design. Both ECR2 and the 6.4 GHz electron cyclotron resonance ion source ECR1 have similarly dimensioned aluminum plasma chambers, both incorporate biased disks, but the experience with each has been much different. The performance and the operation of the two sources are compared.

  2. Medical Device Safety

    MedlinePLUS

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Medical Devices Print this page Share this page E-mail this page Home Medical Devices Medical Device Safety Medical Device Safety Search the Medical Device Safety Section Medical ...

  3. Ion Cyclotron Waves at Titan: Harbingers of Atmospheric Loss

    NASA Astrophysics Data System (ADS)

    Russell, C. T.; Wei, H. Y.; Cowee, M. M.; Neubauer, F.; Dougherty, M. K.

    2014-04-01

    When a flowing magnetized plasma intercepts a neutral atmosphere such as Titan's exosphere, we expect that any atoms or molecules that become ionized by photoionization impact ionization or charge exchange could lead to the acceleration and pick-up of those newly formed ions. This process creates an ion distribution function that often is highly unstable to the production of ion-cyclotron waves. Such waves have been observed in the Earth's polar cusp [1], at the Moon [2], at Mars [3], at Io [4], and at Enceladus [5]. We had expected also to observe these waves at Titan but neither the Voyager Titan passage nor the early Cassini Titan flybys produced ion-cyclotron waves. Modelling studies have suggested that the growth time is long and the waves will not grow until some distance far downstream. However, on two passes by Titan T63 and T98, ion cyclotron waves have been seen with the T98 wave field having been much more pronounced. Figure 1 below shows the transverse and compressional power as dynamic spectra versus time on the T98 inbound pass to Titan. The ion cyclotron waves clearly arise at the expected frequency just below the piston cyclotron frequency. It is remarkable that no such waves are seen outbound at T98.This is in agreement with the initial trajectories of newborn ions which lead away from the dense deeper atmosphere inbound and into the dense deeper atmosphere outbound. On the T63 pass, a short period of waves was seen near the proton and H2+ cyclotron frequencies. We discuss these rare ion cyclotron waves at Titan in the light of hybrid simulations of ion pickup under conditions in Saturn's outer magnetosphere.

  4. 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 ?-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.

  5. The Oak Ridge Isochronous Cyclotron Refurbishment Project

    SciTech Connect

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

    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. Analytical representation of cyclotron magnetic field

    SciTech Connect

    Lee-Whiting, G.E.; Davies, W.G. [AECL Research, Chalk River, Ontario (Canada). Chalk River Labs.] [AECL Research, Chalk River, Ontario (Canada). Chalk River Labs.

    1994-07-01

    A model has been developed for the rapid but accurate calculation of the static magnetic field in the Chalk River cyclotron. The field is expressed in terms of elementary functions which can be handled efficiently in differential-algebra trajectory integrations. Maxwell`s equations are satisfied exactly. Each of seven subdivisions of the superconducting coils is treated by a moment expansion about a central circle. Each pole is modeled as a uniformly magnetized semi-infinite prism. Monopoles and dipoles at the vertices of the polygonal pole faces correct for departures from the true pole shape. Uniform distributions of dipole strength along the edges of the pole-face polygons correct for the local inappropriateness of the assumption of uniform magnetization. The contributions of the yoke and of other relatively distant parts of the structure to the field in the region of particle acceleration are represented by low-order polynomials. Some of the source parameters are obtained by fitting to the measured values of B{sub z} in the horizontal plane of symmetry.

  7. Characterization of electron cyclotron resonance hydrogen plasmas

    SciTech Connect

    Outten, C.A. (Michigan Univ., Ann Arbor, MI (USA). Dept. of Nuclear Engineering); Barbour, J.C.; Wampler, W.R. (Sandia National Labs., Albuquerque, NM (USA))

    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.

  8. Electron cyclotron emission diagnostic for ITER.

    PubMed

    Rowan, W; Austin, M; Beno, J; Ellis, R; Feder, R; Ouroua, A; Patel, A; Phillips, P

    2010-10-01

    Electron temperature measurements and electron thermal transport inferences will be critical to the nonactive and deuterium phases of ITER operation and will take on added importance during the alpha heating phase. The diagnostic must meet stringent criteria on spatial coverage and spatial resolution during full field operation. During the early phases of operation, it must operate equally well at half field. The key to the diagnostic is the front end design. It consists of a quasioptical antenna and a pair of calibration sources. The radial resolution of the diagnostic is less than 0.06 m. The spatial coverage extends at least from the core to the separatrix with first harmonic O-mode being used for the core and second harmonic X-mode being used for the pedestal. The instrumentation used for the core measurement at full field can be used for detection at half field by changing the detected polarization. Intermediate fields are accessible. The electron cyclotron emission systems require in situ calibration, which is provided by a novel hot calibration source. The critical component for the hot calibration source, the emissive surface, has been successfully tested. A prototype hot calibration source has been designed, making use of extensive thermal and mechanical modeling. PMID:21033963

  9. 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. PMID:18315111

  10. Characterization of electron cyclotron resonance hydrogen plasmas

    SciTech Connect

    Outten, C.A. (Department of Nuclear Engineering, University of Michigan, Ann Arbor, Michigan 48109 (USA)); Barbour, J.C.; Wampler, W.R. (Sandia National Laboratories, Albuquerque, New Mexico 87185 (USA))

    1991-05-01

    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 ({ital V}{sub {ital p}} ), electron density ({ital N}{sub {ital e}} ), electron temperature ({ital T}{sub {ital e}} ), ion energy ({ital T}{sub {ital 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 W of absorbed power. These results gave {ital V}{sub {ital p}} =30{plus minus}5 eV, {ital N}{sub {ital e}} =1{times}10{sup 8} cm{sup {minus}3}, and {ital T}{sub {ital e}} =10--13 eV. In good agreement with the Langmuir probe results, carbon resistance probes have shown that {ital T}{sub {ital 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} s at a pressure of 1{times}10{sup {minus}4} Torr and for 50 W of absorbed power.

  11. Fullerenes in electron cyclotron resonance ion sources

    SciTech Connect

    Biri, S.; Fekete, E.; Kitagawa, A.; Muramatsu, M.; Janossy, A.; Palinkas, J. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/C (Hungary); National Institute for Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Department of Experimental Physics, Technical University of Budapest, H-1521 Budapest, P.O. Box 91 (Hungary); Department of Experimental Physics, University of Debrecen, H-4026 Debrecen, Bem ter 18/A (Hungary)

    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.

  12. Modelling of Ion Cyclotron Wall Conditioning plasmas

    SciTech Connect

    Douai, D.; Wauters, T.; Wuenderlich, D.; Bremond, S.; Lombard, G.; Mollard, P.; Pegourie, B. [CEA, IRFM, 13108 St Paul lez Durance (France); Lyssoivan, A. [LPP-ERM/KMS, 1000 Brussels (Belgium); Marchuk, O. [IEK-4, FZ Juelich, 52425 Juelich (Germany); Van Oost, G. [Ghent University, 9000 Ghent (Belgium)

    2011-12-23

    Ion Cyclotron Wall Conditioning (ICWC) is envisioned in ITER to clean the wall from impurities, to control the wall isotopic ratio and the hydrogen recycling in the presence of the toroidal magnetic field. Various experiments and modelling are advancing to consolidate this technique. In this contribution the modeling of ICWC is presented, which can be divided in two parts: plasma description and plasma wall interaction. Firstly a 0D plasma model, based on a set of energy and particle balance equations for Maxwellian Hydrogen and Helium species, is presented. The model takes into account elementary collision processes, coupled RF power, particle confinement, wall recycling, and active gas injection and pumping. The RF plasma production process is based mainly on electron collisional ionization. The dependency of the plasma parameters, the Hydrogen and Helium partial pressures and neutral or ionic fluxes on pressure and RF power are quantitatively in good agreement with those obtained experimentally on TORE SUPRA. Secondly an extension of the 0D model including the description of the wall interaction is presented and compared to TORE SUPRA multi-pulse ICWC discharges.

  13. Botox (Medical)

    MedlinePLUS

    ... included in your message Your e-mail address: Your name: Your friend's e-mail address: Your friend's name: ... Close without sharing. Give Us Feedback Botox (Medical) Your name First Name MI Laast Name Your e-mail ...

  14. Medication Treatments

    MedlinePLUS

    ... Information How is the FMR1 mutation related to Fragile X-associated disorders? What causes it? How many people ... approved any drugs specifically for the treatment of Fragile X or its symptoms. But in many cases, medications ...

  15. Medical Scientists

    MedlinePLUS

    ... must use their expertise to determine the best method for solving a specific research question. Data-analysis skills. Medical scientists use statistical techniques, so that they can properly quantify and ...

  16. Medication Treatment

    MedlinePLUS

    ... behavior, such as to reduce self-injury or aggression. Once a symptom is no longer a problem, ... of repetitive behaviors; decrease anxiety, irritability, tantrums, and aggressive behavior; and improve eye contact. Tricyclics These medications ...

  17. Cardiac Medications

    MedlinePLUS

    ... lowering medications may interact with grapefruit, grapefruit juice, pomegranate and pomegranate juice. Please talk to your health care provider ... attacks, or "little strokes") and other forms of cardiovascular disease. Usually prescribed preventively when plaque buildup is ...

  18. Medical Imaging.

    ERIC Educational Resources Information Center

    Barker, M. C. J.

    1996-01-01

    Discusses four main types of medical imaging (x-ray, radionuclide, ultrasound, and magnetic resonance) and considers their relative merits. Describes important recent and possible future developments in image processing. (Author/MKR)

  19. 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.

  20. Medical Acoustics

    NASA Astrophysics Data System (ADS)

    Beach, Kirk; Dunmire, Barbrina

    Medical acoustics can be subdivided into diagnostics and therapy. Diagnostics are further separated into auditory and ultrasonic methods, and both employ low amplitudes. Therapy (excluding medical advice) uses ultrasound for heating, cooking, permeablizing, activating and fracturing tissues and structures within the body, usually at much higher amplitudes than in diagnostics. Because ultrasound is a wave, linear wave physics are generally applicable, but recently nonlinear effects have become more important, even in low-intensity diagnostic applications.

  1. Medical education.

    PubMed

    Krishnan, P

    1992-01-01

    In theory, the Medical Council of India (MCI) determines the standards and qualifications of medical schools. It also sanctions curricula and ensures standards. Yet no standards exist on the mode of selection in medical schools, duration of study, course content, student stipends or period of internship. It takes 4.5 years to finish medical school. Students undergo preclinical, paraclinical, and clinical training. Most courses are in English which tends to favor the urban elite. Students cannot always communicate with patients in local languages. Textbooks often provide medical examples unrelated to India. Pedagogy consists mainly of lectures and rote learning predominates. Curricula tend not to provide courses in community health. Students pick up on the elitist attitudes of the faculty. For example, faculty do not put much emphasis on community health, individual health, equity in health care delivery, and teamwork. Further the education system is not patient oriented, but hospital or disease oriented. Faculty should train students in creating sanitation programs, knowing local nutritious foods, and in making community diagnoses. Yet they tend to be practitioners 1st then educators. Further faculty are not paid well and are not always invited to take part in improving curriculum, so morale is often low. Moreover experience in health planning and management issues is not required for administrators. In addition, medical schools are not well equipped with learning aids, libraries, or teaching staff. Tax revenues finance medical education. 75% of graduating physicians set up a private practice. Further many physicians go to urban areas. 34-57% emigrate to other countries. The problems of medical education will not be solved until the political and economic system becomes more responsive to the health needs of the people. PMID:12343653

  2. Medication Math

    NSDL National Science Digital Library

    Joey

    2008-10-16

    Medication calculation needs to be completed accurately for proper patient treatment. In this section you will need to review and improve your medication math. Understanding math: Math and Culture Refresher: Take the amount of fluid in the bottle and times that by the dose ordered. Then divide this number by the amount of drug in the bottle. This will give you the volume of the drug that you need to administer. Diagram of formulas Math Formulas Math ...

  3. Trends of Medication Errors in Hospitalized Children

    Microsoft Academic Search

    Gideon Koren

    2002-01-01

    Medication errors are a major cause of morbidity and mortality among hospitalized children. Due to the small volumes of stock solution involved, even a large error may look as an unsuspiciously small dose. Strategies were implemented to reduce medication errors in a large tertiary pediatric hospital in Toronto. Starting in 1993, several initiatives were taken, including a newhospital computer system

  4. A Small \\

    Microsoft Academic Search

    D. K. Wells

    1967-01-01

    High beam currents have been achieved with a radial source which fits into the 2-inch gap of a 30-inch cyclotron. The geometry is that of a cold-cathode or P. I. G. source. However, the cathodes are heated to thermionic temperatures by ion bombardment rather than a conventional high-current heated filament. The source is now in use and produces intense beams

  5. 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.

  6. 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

    ...OF COMMERCE International Trade Administration National Superconducting Cyclotron Laboratory of Michigan State University; Notice...DC. Docket Number: 10-043. Applicant: National Superconducting Cyclotron Laboratory of Michigan State University....

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

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Tanushyam; Kanti Dey, Malay; Dhara, Partha; Roy, Suvodeep; Debnath, Jayanta; Balakrishna Bhole, Rajendra; Dutta, Atanu; Pradhan, Jedidiah; Pal, Sarbajit; Pal, Gautam; Roy, Amitava; Chakrabarti, Alok

    2013-05-01

    In an isochronous cyclotron, measurements of central phase of the ion beam with respect to rf and the phase width provide a way to tune the cyclotron for maximum energy gain per turn and efficient extraction. We report here the development of a phase measurement system and the measurements carried out at the Variable Energy Cyclotron Centre's (VECC's) K = 500 superconducting cyclotron. The technique comprises detecting prompt ?-rays resulting from the interaction of cyclotron ion beam with an aluminium target mounted on a radial probe in coincidence with cyclotron rf. An assembly comprising a fast scintillator and a liquid light-guide inserted inside the cyclotron was used to detect the ?-rays and to transfer the light signal outside the cyclotron where a matching photo-multiplier tube was used for light to electrical signal conversion. The typical beam intensity for this measurement was a few times 1011 pps.

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

    PubMed

    Bhattacharjee, Tanushyam; Kanti Dey, Malay; Dhara, Partha; Roy, Suvodeep; Debnath, Jayanta; Balakrishna Bhole, Rajendra; Dutta, Atanu; Pradhan, Jedidiah; Pal, Sarbajit; Pal, Gautam; Roy, Amitava; Chakrabarti, Alok

    2013-05-01

    In an isochronous cyclotron, measurements of central phase of the ion beam with respect to rf and the phase width provide a way to tune the cyclotron for maximum energy gain per turn and efficient extraction. We report here the development of a phase measurement system and the measurements carried out at the Variable Energy Cyclotron Centre's (VECC's) K = 500 superconducting cyclotron. The technique comprises detecting prompt ?-rays resulting from the interaction of cyclotron ion beam with an aluminium target mounted on a radial probe in coincidence with cyclotron rf. An assembly comprising a fast scintillator and a liquid light-guide inserted inside the cyclotron was used to detect the ?-rays and to transfer the light signal outside the cyclotron where a matching photo-multiplier tube was used for light to electrical signal conversion. The typical beam intensity for this measurement was a few times 10(11) pps. PMID:23742541

  9. Electron cyclotron wave resonance plasma assisted deposition of cubic boron nitride thin films

    E-print Network

    Zexian, Cao

    Electron cyclotron wave resonance plasma assisted deposition of cubic boron nitride thin films Z. X-pressure plasma source. The electron-cyclotron-wave resonance ECWR plasma served both to sputter the hBN target

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

    SciTech Connect

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

    2013-05-15

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

  11. 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.

  12. Physica E 34 (2006) 640643 Geometric resonance of bragg-reflected cyclotron orbits in

    E-print Network

    Katsumoto, Shingo

    Physica E 34 (2006) 640­643 Geometric resonance of bragg-reflected cyclotron orbits in a unidirectional lateral superlattice (ULSL) attributable to the geometric resonance of Bragg-reflected cyclotron

  13. Cyclotron Resonance in Bilayer Graphene PI: Horst Stormer, Department of Physics, Columbia University

    E-print Network

    Cyclotron Resonance in Bilayer Graphene PI: Horst Stormer, Department of Physics, Columbia of the cyclotron resonance of electrons and holes in bilayer graphene. In magnetic fields up to B=18T we observe

  14. A compact superconducting cyclotron for the production of high intensity protons

    Microsoft Academic Search

    H. Blosser; D. Johnson; D. Lawton; F. Marti; R. Ronningen; J. Vincent

    1997-01-01

    This paper reviews a study of a compact superconducting cyclotron to accelerate 200 microamps of protons to 250 MeV. The basic cyclotron structure is the same as that developed in a previous study of a 250 MeV cancer therapy cyclotron, the chief difference in the study reported here being much higher beam current (x10,000) than in the therapy cyclotron to

  15. Medical Transcriptionists: Making Medical Histories.

    ERIC Educational Resources Information Center

    Shniper, Lynn

    2001-01-01

    Medical transcriptionists are experts in the language of medicine. Describes what they do and what their working conditions, earnings, employment prospects, and training requirements are. Includes sources of additional information. (Author)

  16. Dittrick Medical History Center

    NSDL National Science Digital Library

    2003-01-01

    Currently operating as an interdisciplinary study center within the College of Arts and Sciences of Case Western Reserve University, the Dittrick Medical History Center was established as part of the Cleveland Medical Library Association in 1894. First-time visitors will definitely want to begin by looking through the museum's history, and then examine the museum artifacts and galleries, which represent a small sample of their holdings. The artifacts are divided into time periods and include such fascinating medical equipment as bloodletting devices, a phrenology bust, and a defribrillator from 1950. The galleries section allows visitors to take a virtual tour of the rooms within the museum, such as a doctor's office from the 1930s and a replica of a pharmacy from the 1880s. Several online exhibits are also available for perusal, such as one dedicated to Cleveland's brush with a smallpox epidemic in 1902. Utterly fascinating, though not for the squeamish, is the exhibit that details medical school photographs, many of them class photographs around dissection tables, and postcards featuring medical students and cadavers. The site is rounded out with a host of online guides and finding aids that help in using the Center's extensive collections dealing with the history of medicine.

  17. 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.

  18. The Texas A & M K500 cyclotron facility

    NASA Astrophysics Data System (ADS)

    Youngblood, D. H.

    1991-05-01

    A K500 superconducting cyclotron, following the MSU design, has been constructed with funds provided by Texas A & M University and The Robert A. Welch Foundation. First beam was extracted in June, 1988, and the first experiments were performed shortly afterward in July using a PIG internal ion source. An electron-cyclotron resonance ion source was constructed and delivered first beam to the cyclotron in November, 1989, and experiments with injected beams began immediately. Experiments are underway with existing instrumentation and a 4 ? neutron calorimeter constructed for heavy ion reaction mechanism studies. A diproton spectrometer for Gamow-Teller studies is nearing completion, and a recoil mass spectrometer and 57-element BaF 2 array are under construction.

  19. Cyclotron resonances in a non-neutral multispecies ion plasma

    NASA Astrophysics Data System (ADS)

    Affolter, M.; Anderegg, F.; Driscoll, C. F.; Dubin, D. H. E.

    2013-03-01

    Shifts of the cyclotron mode frequencies, away from the single particle limit, are observed to be proportional to the measured E × B rotation frequency in a non-neutral ion plasma. These cylindrical ion plasmas consist of 24Mg+, 25Mg+, and 26Mg+; with H3O+, and O2+ impurities. Laser cooling of the 24Mg+ majority species enables temperature control over the range 10-5 < T < 10-2 eV, as well as determination of cyclotron mode frequencies from launched wave absorption. At moderately low temperatures, the m? = 1 and m? = 2 cyclotron frequency shifts are well described by cold fluid theory for an equilibrium square profile. However, for T < 10-3 eV, centrifugal mass separation can shift the mode frequency back towards the single particle limit.

  20. Cyclotron-resonance maser in a magnetic mirror.

    PubMed

    Caspi, R; Jerby, E

    1999-08-01

    A cyclotron-resonance maser (CRM) experiment is performed in a high-gradient magnetic field using a low-energy electron beam ( approximately 10 keV/1 A). The magnetic field exceeds 1.63 T, which corresponds to a 45-GHz cyclotron frequency. The CRM radiation output is observed in much lower frequencies, between 6.6 and 20 GHz only. This discrepancy is explained by the finite penetration depth of the electrons into the growing magnetic field, as in a magnetic mirror. The electrons emit radiation at the local cyclotron frequency in their reflection point from that magnetic mirror; hence, the radiation frequency depends mostly on the initial electron energy. A conceptual reflex gyrotron scheme is proposed in this paper, as a CRM analogue for the known reflex klystron. PMID:11970042

  1. 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.

  2. Improvements to the analytical capabilities of Fourier transform ion cyclotron resonance mass spectrometry

    Microsoft Academic Search

    Limbach

    1992-01-01

    Improvements to the utility of Fourier transform ion cyclotron resonance mass spectrometry for analytical mass spectrometry are presented. Various ion packet decay models are investigated for both singly and multiply charged ions. A new ion trap allows for determination of the cyclotron radius of the ion packet with improved sensitivity. The cyclotron radius of the ion packet can be measured

  3. Optimized magnet for a 250 MeV proton radiotherapy cyclotron

    Microsoft Academic Search

    J. Kim; H. Blosser

    2001-01-01

    The NSCL accelerator group in 1993 carried out an extensive design study [1] for a K250 superconducting cyclotron for advanced cancer therapy. A private company ACCEL now offers cyclotrons based on this study on a commercial basis, and actual construction of a first such cyclotron is likely in the near future. In view of this, further optimization of the design

  4. ACCELERATORS: Central region design for a 10 MeV internal ion source cyclotron

    Microsoft Academic Search

    Bin Qin; Kai-Feng Liu; Yi-Zhang Feng; Ming-Wu Fan

    2009-01-01

    Internal ion sources are widely adopted in commercial cyclotrons used for short-life isotopes production. Without beam manipulation provided by the external beam injection line, the central region of this type of cyclotron is more sensitive and should be carefully designed. A design study and beam dynamics simulation for the central region of a 10 MeV compact cyclotron is presented. The

  5. SPITZER IRS SPECTROSCOPY OF INTERMEDIATE POLARS: CONSTRAINTS ON MID-INFRARED CYCLOTRON EMISSION

    E-print Network

    Harrison, Thomas

    SPITZER IRS SPECTROSCOPY OF INTERMEDIATE POLARS: CONSTRAINTS ON MID-INFRARED CYCLOTRON EMISSION into the mid-infrared. There is no evidence for discrete cyclotron emission features in the near- or mid, and possibly EX Hya and V1223 Sgr, do show longer wavelength excesses. We have used a cyclotron modeling code

  6. Electrostatic ion-cyclotron waves driven by parallel velocity shear R. L. Merlinoa)

    E-print Network

    Merlino, Robert L.

    Electrostatic ion-cyclotron waves driven by parallel velocity shear R. L. Merlinoa) Department cyclotron frequency propagating at large angles to the ambient magnetic field can be excited in a magnetized in determining the stability of shear-driven electrostatic ion-cyclotron EIC modes is also considered

  7. Cyclotron waves in a non-neutral plasma column Daniel H. E. Dubin

    E-print Network

    California at San Diego, University of

    #12;Cyclotron waves in a non-neutral plasma column Daniel H. E. Dubin Department of Physics with frequencies near the cyclotron frequency Xcs of a given plasma species s is developed for a multispecies non distribution function up to Oð1=X2 cs � are kept, as are the effects of finite cyclotron radius rc up to Oðr2 c

  8. Radially Localized Measurements of Superthermal Electrons Using Oblique Electron Cyclotron Emission

    E-print Network

    Radially Localized Measurements of Superthermal Electrons Using Oblique Electron Cyclotron Emission Electron Cyclotron Emission from superthermal electrons can be imposed by observation of emission upshifted from the thermal cyclotron resonance in the horizontal midplane of a tokamak. A new and unique

  9. ELECTRON CYCLOTRON RESONANCE DISCHARGE AS A SOURCE FOR HYDROGEN AND DEUTERIUM IONS PRODUCTION

    E-print Network

    Boyer, Edmond

    1 ELECTRON CYCLOTRON RESONANCE DISCHARGE AS A SOURCE FOR HYDROGEN AND DEUTERIUM IONS PRODUCTION@uis.edu.co In this report, we describe characteristics of a ring-structure hydrogen plasma heated in electron cyclotron are observed in an electron cyclotron resonance (ECR) plasma source, #12;2 with the reaction channel involving

  10. Generation and propagation of cyclotron maser emissions in the finite auroral kilometric radiation source cavity

    E-print Network

    California at Berkeley, University of

    Generation and propagation of cyclotron maser emissions in the finite auroral kilometric radiation of the electron-cyclotron maser radiation produced in the auroral kilometric radiation (AKR) source cavity Plasma Physics: Numerical simulation studies; KEYWORDS: wave-particle interaction, cyclotron maser

  11. Cyclotron waves in a non-neutral plasma column Daniel H. E. Dubin

    E-print Network

    California at San Diego, University of

    Cyclotron waves in a non-neutral plasma column Daniel H. E. Dubin Citation: Phys. Plasmas 20://pop.aip.org/authors #12;Cyclotron waves in a non-neutral plasma column Daniel H. E. Dubin Department of Physics with frequencies near the cyclotron frequency Xcs of a given plasma species s is developed for a multispecies non

  12. CYCLOTRON RESONANCE IN HIGH MAGNETIC FIELDS Department of Electrical and Computer Engineering, Rice University,

    E-print Network

    Kono, Junichiro

    CYCLOTRON RESONANCE IN HIGH MAGNETIC FIELDS J. KONO Department of Electrical and Computer review recent cyclotron resonance studies of semiconductors performed in high magnetic fields that can shed light on carrier-interaction effects on cyclotron resonance. In addition, we discuss new

  13. Two-dimensional cyclotron-resonance maser array: Spectral measurements with one and two electron beams

    E-print Network

    Jerby, Eli

    Two-dimensional cyclotron-resonance maser array: Spectral measurements with one and two electron Received 8 September 1997; revised manuscript received 17 September 1998 The cyclotron-resonance-maser CRM array is a device in which separate electron beams perform simul- taneously a cyclotron interaction

  14. Cyclotron Waves in a Nonneutral Plasma Column Daniel H.E. Dubin

    E-print Network

    California at San Diego, University of

    Cyclotron Waves in a Nonneutral Plasma Column Daniel H.E. Dubin Department of Physics, University]) Abstract A kinetic theory of linear electrostatic plasma waves with frequencies near the cyclotron/2 cs ) are kept, as are the effects of finite cyclotron radius rc up to O(r2 c ). At this order

  15. Cyclotron-resonance maser in a periodically loaded quadrupole transmission line Y. Leibovitch and E. Jerby*

    E-print Network

    Jerby, Eli

    Cyclotron-resonance maser in a periodically loaded quadrupole transmission line Y. Leibovitch and E; revised manuscript received 17 February 1999 A cyclotron-resonance maser CRM is implemented in a periodic quadrupole waveguide. The device oscillates at the fundamental and high harmonics of the cyclotron frequency

  16. Cyclotron Resonance of Itinerant Holes in Ferromagnetic InMnAs/GaSb Heterostructures

    E-print Network

    Kono, Junichiro

    Cyclotron Resonance of Itinerant Holes in Ferromagnetic InMnAs/GaSb Heterostructures G. A, Yokohama, Kanazawa 226-8503, Japan Abstract. We report the first observation of hole cyclotron resonance describe our observation of hole cyclotron resonance (CR) in ferromagnetic InMnAs/GaSb heterostructures

  17. Cyclotron absorption of radio emission within pulsar magnetospheres Qinghuan LuoP

    E-print Network

    Melrose, Don

    Cyclotron absorption of radio emission within pulsar magnetospheres Qinghuan LuoP and D. B. Melrose T Absorption of radio emission through normal cyclotron resonance within pulsar magneto- spheres is considered. The optical depth for cyclotron damping is calculated using a plasma distribution with an intrinsically

  18. Interrelation of noise-like and discrete ELF\\/VLF emissions generated by cyclotron interactions

    Microsoft Academic Search

    V. Y. Trakhtengerts; M. J. Rycroft; A. G. Demekhov

    1996-01-01

    It is shown that quasi-monochromatic wves (wvelets) cn be cused by the strong cyclotron instability, stimulated by hiss emissions. The hiss, generated by the cyclotron instability ofnnisotropic smooth energetic electron distribution, createsstep-like deformation of the distribution functiont the boundary between resonantnd nonresonant electrons. This deformation leds to the strongmplifiction of the wvelet whose frequency corresponds to that for cyclotron resonance

  19. Electrostatic electron cyclotron waves generated by low-energy electron beams

    E-print Network

    Santolik, Ondrej

    Electrostatic electron cyclotron waves generated by low-energy electron beams J. D. Menietti, O by the Polar spacecraft at high altitudes and latitudes and at frequencies just above the cyclotron frequency. D. Scudder, J. S. Pickett, and D. A. Gurnett, Electrostatic electron cyclotron waves generated

  20. Inhomogeneous cyclotron emission source for the five branch mode conversion problem

    E-print Network

    Ng, Chung-Sang

    Inhomogeneous cyclotron emission source for the five branch mode conversion problem C. S. Ng, V. F distribution from a cyclotron mode conversion layer are extended to the five branch wave coupling case which source distribution from a cyclotron layer.3 Besides obvious theoretical interest, the problem

  1. Quantum Jumps Between Fock States of an Ultracold Electron Cyclotron Oscillator

    E-print Network

    Gabrielse, Gerald

    Quantum Jumps Between Fock States of an Ultracold Electron Cyclotron Oscillator A thesis presented 1999 by Steven Eric Peil All rights reserved #12;Abstract Fock states of a one-electron cyclotron to the n = 4 cyclotron level have been observed. The potential line broadening from the increased magnetic

  2. Cold Electrostatic Ion Cyclotron Waves for Preionization and IBW Launching in LHD *

    E-print Network

    ­ 1 ­ Cold Electrostatic Ion Cyclotron Waves for Preionization and IBW Launching in LHD * Masayuki CESICW (Cold Electrostatic Ion Cyclotron Wave) for heating the core of LHD with the folded waveguide research. Electron cyclotron heating (ECH) is a well­known effective tool for plasma production

  3. The role of ion cyclotron motion at Ganymede: Magnetic field morphology and magnetospheric dynamics

    E-print Network

    Black, Robert X.

    The role of ion cyclotron motion at Ganymede: Magnetic field morphology and magnetospheric dynamics 2006; published 31 May 2006. [1] Ion cyclotron motion can play a role in shaping magnetospheres planets. However, MHD explicitly neglects such effects. We demonstrate the importance of ion cyclotron

  4. Generation of "spiky" potential structures associated with multiharmonic electrostatic ion-cyclotron waves

    E-print Network

    Merlino, Robert L.

    Generation of "spiky" potential structures associated with multiharmonic electrostatic ion-cyclotron plasma. These structures are associated with coherent multiharmonic electrostatic ion-cyclotron EIC waves of the potential fluctuations exhibit spiky structures with repetition rates near the ion-cyclotron frequency

  5. Cyclotron-resonance maser in a magnetic mirror Ronen Caspi and Eli Jerby*

    E-print Network

    Jerby, Eli

    Cyclotron-resonance maser in a magnetic mirror Ronen Caspi and Eli Jerby* Faculty of Engineering, Tel Aviv University, Ramat Aviv 69978, Israel Received 4 February 1999 A cyclotron-resonance maser CRM A . The magnetic field exceeds 1.63 T, which corresponds to a 45-GHz cyclotron frequency. The CRM radiation output

  6. PPPL3119 Preprint: July 1995, UC426 Alfvnic Behavior of Alpha Particle Driven Ion Cyclotron

    E-print Network

    PPPL­3119 ­ Preprint: July 1995, UC­426 Alfvénic Behavior of Alpha Particle Driven Ion Cyclotron, Oxfordshire, OX14 3DB UK (Euratom/UKAEA Fusion Association) ABSTRACT Ion cyclotron emission (ICE) has been the top and bottom of the vacuum vessel. Harmonics of the alpha cyclotron frequency (W a ) evaluated

  7. PPPL-3119 -Preprint: July 1995, UC-426 Alfvnic Behavior of Alpha Particle Driven Ion Cyclotron

    E-print Network

    PPPL-3119 - Preprint: July 1995, UC-426 Alfvénic Behavior of Alpha Particle Driven Ion Cyclotron, Oxfordshire, OX14 3DB UK (Euratom/UKAEA Fusion Association) ABSTRACT Ion cyclotron emission (ICE) has been the top and bottom of the vacuum vessel. Harmonics of the alpha cyclotron frequency ( ) evaluated

  8. Cyclotron Resonance in Bilayer Graphene E. A. Henriksen,1,* Z. Jiang,1,2

    E-print Network

    Kim, Philip

    Cyclotron Resonance in Bilayer Graphene E. A. Henriksen,1,* Z. Jiang,1,2 L.-C. Tung,2 M. E 2007; published 27 February 2008) We present the first measurements of cyclotron resonance of electrons recently been observed in infrared (IR) cyclotron resonance (CR) [9,10]. In contrast, bilayer gra- phene

  9. Cold Electrostatic Ion Cyclotron Waves for Preionization and IBW Launching in LHD*

    E-print Network

    - 1 - Cold Electrostatic Ion Cyclotron Waves for Preionization and IBW Launching in LHD* Masayuki CESICW (Cold Electrostatic Ion Cyclotron Wave) for heating the core of LHD with the folded waveguide research. Electron cyclotron heating (ECH) is a well-known effective tool for plasma production

  10. CYCLOTRON HEATING NFR THE MULTIPOLE B = 0 AXIS J. C. Sprott

    E-print Network

    Sprott, Julien Clinton

    CYCLOTRON HEATING NFR THE MULTIPOLE B = 0 AXIS by J. C. Sprott November 1973 PLP 536 Plasma Studies of the author and major professor. #12;Ion and Electron Cyclotron heating rates in multipoles are generally- is the multipole number and a is a constant. The cyclotron reso- nance zone then is in the shape of a large aspect

  11. Superradiant Decay of Cyclotron Resonance of Two-Dimensional Electron Gases Takashi Arikawa,1,*

    E-print Network

    Natelson, Douglas

    Superradiant Decay of Cyclotron Resonance of Two-Dimensional Electron Gases Qi Zhang,1 Takashi on the observation of collective radiative decay, or superradiance, of cyclotron resonance (CR) in high-mobility two through cyclotron resonance (CR) absorption [7]. How rapidly the coherence of this many-body superposition

  12. PHYSICAL REVIEW B 85, 205407 (2012) Circular polarization dependent cyclotron resonance in large-area graphene

    E-print Network

    Kono, Junichiro

    .67 m, we studied cyclotron resonance in large-area graphene grown by chemical vapor depositionPHYSICAL REVIEW B 85, 205407 (2012) Circular polarization dependent cyclotron resonance in large-area-field studies therefore allow for a clear identification of cyclotron resonance features in large-area, low

  13. Ferrite-guided cyclotron-resonance maser Eli Jerby,* A. Kesar, A. Aharony, and G. Breitmeier

    E-print Network

    Jerby, Eli

    Ferrite-guided cyclotron-resonance maser Eli Jerby,* A. Kesar, A. Aharony, and G. Breitmeier manuscript received 20 February 2002; published 10 June 2002 The concept of a cyclotron-resonance maser CRM.40.Az I. INTRODUCTION Cyclotron resonance masers CRM's are well-known sources of high-power microwaves

  14. ION CYCLOTRON HEATING IN THE WISCONSIN SUPPORTED TOROIDAL OCTUPOLE AND QUADRUPOLE,

    E-print Network

    Sprott, Julien Clinton

    PLP 730 ION CYCLOTRON HEATING IN THE WISCONSIN SUPPORTED TOROIDAL OCTUPOLE AND QUADRUPOLE, A. P only and are not to be further transmitted without consent of the authors. #12;. -"- ION CYCLOTRON cyclotron heating 'at the fundamental fre- quency in the supported octupole has produced "-600 eV ions

  15. Cyclotron resonance photoconductivity of a two-dimensional electron gas in HgTe quantum wells

    E-print Network

    Ganichev, Sergey

    Cyclotron resonance photoconductivity of a two-dimensional electron gas in HgTe quantum wells Ze-infrared cyclotron resonance photoconductivity (CRP) is investigated in HgTe quantum wells (QWs) of various widths that the transport time substantially exceeds the cyclotron resonance lifetime as well as the quantum lifetime which

  16. Multiple Cyclotron Lines in the Spectrum of 4U 0115+63

    E-print Network

    Barnstedt, Jürgen

    Multiple Cyclotron Lines in the Spectrum of 4U 0115+63 W.A. Heindl \\Lambda , W. Coburn \\Lambda , D 24 day orbit [1] with an O9e star [9]. A cyclotron resonance scattering feature (CRSF) was first experiment and found an additional feature at ¸12 keV, making 4U 0115+63 the first pulsar with two cyclotron

  17. Electron-cyclotron wave propagation, absorption and current drive in the presence of neoclassical tearing modes

    E-print Network

    Isliker, Heinz

    Electron-cyclotron wave propagation, absorption and current drive in the presence of neoclassical.1088/0741-3335/54/9/095005 Electron-cyclotron wave propagation, absorption and current drive in the presence of neoclassical tearing the propagation of electron-cyclotron waves, their absorption and current drive when neoclassical tearing modes

  18. CYCLOTRON RESONANCE IN A TWO-DIMENSIONAL ELECTRON GAS WITH LONG-RANGE DISORDER

    E-print Network

    Fogler, Michael

    CYCLOTRON RESONANCE IN A TWO-DIMENSIONAL ELECTRON GAS WITH LONG-RANGE DISORDER M. M. FOGLER School that the the cyclotron resonance in a two-dimensional electron gas has nontrivial properties if the correlation length with the di usive classical motion and a resulting very large quantum localization length. The cyclotron

  19. ION CYCLOTRON RESONANCE HEATING IN A TOROIDAL OCTUPOLE J. C. Sprott and J. D. Barter

    E-print Network

    Sprott, Julien Clinton

    ION CYCLOTRON RESONANCE HEATING IN A TOROIDAL OCTUPOLE J. C. Sprott and J. D. Barter May 1976 at the ion cyclotron frequency (2.6 MHz) has been used to heat the ions from for a high neutral re flux are observed to accompany the heating. Ion cyclotron resonance heating

  20. Electron-cyclotron wave scattering by edge density fluctuations in ITER Christos Tsironis,1,2

    E-print Network

    Isliker, Heinz

    Electron-cyclotron wave scattering by edge density fluctuations in ITER Christos Tsironis,1 October 2009; published online 20 November 2009 The effect of edge turbulence on the electron-cyclotron influence on localized heating and current drive. A wave used for electron-cyclotron current drive ECCD must

  1. Cyclotron resonance maser experiments in a bifilar helical waveguide Alon Aharony, Rami Drori, and Eli Jerby*

    E-print Network

    Jerby, Eli

    Cyclotron resonance maser experiments in a bifilar helical waveguide Alon Aharony, Rami Drori 2000 Oscillator and amplifier cyclotron-resonance-maser CRM experiments in a spiral bifilar waveguide, 84.40.Ik, 84.40.Az I. INTRODUCTION Cyclotron resonance masers CRM's and related gyrode- vices

  2. Electron cyclotron microinstability in the foot of a perpendicular shock: A self-consistent PIC simulation

    E-print Network

    California at Berkeley, University of

    Electron cyclotron microinstability in the foot of a perpendicular shock: A self-consistent PIC simulations of perpendicular shocks and found that an electron cyclotron micr- oinstability can develop, has a frequency comparable to the electron cyclotron frequency and a wavelength shorter than

  3. ION CYCLOTRON HEATING IN A TOROIDAL OC TUPOLE J. D. Barter and J. C. Sprott

    E-print Network

    Sprott, Julien Clinton

    ION CYCLOTRON HEATING IN A TOROIDAL OC TUPOLE J. D. Barter and J. C. Sprott February 1975;ION CYCLOTRON HEAT ING IN A TOROIDAL OCTUPOLE J. ,D. Barter and J. C. Sprott University of Wisconsin Madison, Wisconsin 53706 ABSTRACT COO-2387-36 RF power near the ion cyclotron resonance frequency has been

  4. A Polarized 3He Beam for Parity Violation Studies on the Princeton Cyclotron

    E-print Network

    Walsworth, Ronald L.

    A Polarized 3He Beam for Parity Violation Studies on the Princeton Cyclotron David Aaron Siegel in the Princeton cyclotron were coupled with calculations that predicted ow rates and inhomogeneity e ects to yield a complete characterization of the 3 He as it is injected into the cyclotron, including a theoretical value

  5. Doppler-shifted cyclotron resonance of fast ions with circularly polarized shear Alfvn wavesa...

    E-print Network

    Heidbrink, William W.

    Doppler-shifted cyclotron resonance of fast ions with circularly polarized shear Alfvén wavesa December 2008; accepted 2 March 2009; published online 16 April 2009 The Doppler-shifted cyclotron in the LAPD of the Doppler-shifted cyclotron resonance of fast ions with SAWs. In that work, the waves were

  6. ccsd-00001798,version1-20Oct2004 Polarization Reversal of Electron Cyclotron Wave

    E-print Network

    Paris-Sud XI, Université de

    ccsd-00001798,version1-20Oct2004 Polarization Reversal of Electron Cyclotron Wave Due to Radial with electron cyclotron resonance (ECR) frequency are experimentally and theoretically investigated for the case Electron cyclotron wave is important plasma waves in the fields of basic plasma physics, nuclear fusion

  7. Medical Biofilms

    PubMed Central

    2009-01-01

    For more than two decades, Biotechnology and Bioengineering has documented research focused on natural and engineered microbial biofilms within aquatic and subterranean ecosystems, wastewater and waste-gas treatment systems, marine vessels and structures, and industrial bioprocesses. Compared to suspended culture systems, intentionally engineered biofilms are heterogeneous reaction systems that can increase reactor productivity, system stability, and provide inherent cell: product separation. Unwanted biofilms can create enormous increases in fluid frictional resistances, unacceptable reductions in heat transfer efficiency, product contamination, enhanced material deterioration, and accelerated corrosion. Missing from B&B has been an equivalent research dialogue regarding the basic molecular microbiology, immunology, and biotechnological aspects of medical biofilms. Presented here are the current problems related to medical biofilms; current concepts of biofilm formation, persistence, and interactions with the host immune system; and emerging technologies for controlling medical biofilms. PMID:18366134

  8. 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.

  9. Theory of propagation of ordinary surface cyclotron waves

    SciTech Connect

    Girka, V. O.; Klyzhka, A. V. [Karazin Kharkiv National University (Ukraine)

    2009-01-15

    The dispersion properties of ordinary surface cyclotron waves in a semiinfinite nonuniform plasma are investigated. The waves propagate across the external magnetic field directed along the plasma surface in a metal waveguide the internal surface of which is covered with a dielectric. The problem is solved analytically in the framework of a kinetic model for plasma particles under the assumption of weak spatial dispersion. The influence of the parameters of the dielectric layer separating the plasma from the metal wall, the shape of the plasma density profile, and the value of the external magnetic field on the dispersion properties of surface cyclotron waves is studied both numerically and analytically.

  10. Improved tuning and matching of ion cyclotron systems

    SciTech Connect

    Swain, D.W.; Goulding, R.H.; Baity, F.W.; Hoffman, D.J. [Oak Ridge National Lab., TN (United States); Pinsker, R.I.; deGrassie, J.S.; Petty, C.C. [General Atomics, San Diego, CA (United States)

    1996-09-01

    Future fusion devices will require delivery of ion cyclotron heating and current drive power during plasma changes (e.g., L-H transition, ELMs). The use of a passive circuit (``ELM dump``) to protect the RF sources during transients has been demonstrated on DIII-D, and the results are applied to the ITER ion cyclotron system in this analysis. In addition, the use of frequency shifting to compensate for plasma load changes is illustrated for a possible ITER tuning and matching system.

  11. Vacuum measurements of the K500 cyclotron accelerator chamber

    SciTech Connect

    Mallory, M.L.; Miller, P.S.; Kuchar, J.; Hudson, E.D.

    1986-01-01

    To evaluate the effectiveness of the unique internal cryopumping system, the pressure in the K500 superconducting cyclotron was measured as a function of radius for various gas flow rates emanating from the internal PIG source. For the test, a nude ion gauge with vertical dimension less than 2.3 cm was built and mounted on the internal beam probe. The effect of magnetic field on the ion gauge reading was determined and a method of degaussing the cyclotron was devised. Data from the normal shielded ion gauge located approximately 6 m away from the median plane was correlated with the internal vacuum measurements.

  12. 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.

  13. 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. PMID:25375713

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

    SciTech Connect

    Jenkins, Thomas G.; Kruger, Scott E. [Tech-X Corporation, 5621 Arapahoe Avenue, Boulder, Colorado 80303 (United States)

    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.

  15. Temperature-resonant cyclotron spectra in confined geometries

    E-print Network

    Andrey Pototsky; Peter Hänggi; Fabio Marchesoni; Sergey Savel'ev

    2011-05-22

    We consider a two-dimensional gas of colliding charged particles confined to finite size containers of various geometries and subjected to a uniform orthogonal magnetic field. The gas spectral densities are characterized by a broad peak at the cyclotron frequency. Unlike for infinitely extended gases, where the amplitude of the cyclotron peak grows linearly with temperature, here confinement causes such a peak to go through a maximum for an optimal temperature. In view of the fluctuation-dissipation theorem, the reported resonance effect has a direct counterpart in the electric susceptibility of the confined magnetized gas.

  16. Backward Wave Cyclotron-Maser Emission in the Auroral Magnetosphere

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

  17. Electrostatic ion cyclotron and ion plasma waves in a symmetric pair-ion plasma cylinder.

    PubMed

    Kono, M; Vranjes, J; Batool, N

    2014-03-14

    Complicated wave behavior observed in the cylindrical pair-ion (fullerene) experiments by Oohara and co-workers are now identified to be low harmonic ion cyclotron waves combined with ion plasma oscillations inherent to kinetic theory. The electrostatic dispersion equation derived is based on an approximation for the current from the exact solutions of the characteristic cylindrical geometry form of the Vlasov plasma equation in a uniform magnetized plasma cylinder surrounded by a larger metal boundary outside a vacuum gap, which thus differs from that in unbounded plasmas. Positive and negative ions, differing only in the sign of their charge, respond to a potential in the same time scale and cooperate to reflect the enhanced kinetic orbital behaviors to the macroscopic propagation characteristics. In addition, the experimental value of the Larmor radius (comparable to the discharge radius but small enough to make the analytic approximation useful) makes higher harmonic ion cyclotron effects both observable and calculable with the appropriate approximation for the kinetic theory. PMID:24679299

  18. Electron-cyclotron-resonance plasma-assisted radio-frequency-sputtered strontium titanate thin films

    NASA Astrophysics Data System (ADS)

    Belsick, J. R.; Krupanidhi, S. B.

    1993-12-01

    Strontium titanate thin films were deposited by electron-cyclotron-resonance plasma-assisted radio-frequency magnetron sputtering. Electron-cyclotron-resonance plasma assistance was employed because of its ability to be used as a source of low-energy bombardment by a high density of species that are highly activated. It was found that both the structure and composition improve with the application of microwave plasma during the deposition. Analysis of the capacitance-voltage characteristics of metal-insulator-semiconductor devices revealed that the quality of the film/substrate interface is dependent on the pressure, atmosphere, and temperature of the deposition. Interfacial traps which give rise to charged surface states and silicon oxide formation have detrimental effects on films deposited on bare silicon substrates. Films on platinum-coated silicon substrates show good dielectric properties. The small-signal dielectric constant and dissipation factor at a frequency of 100 kHz were 170 and 0.033, respectively. For a 0.37-?m-thick film a charge storage density of 28 fC/?m2 and a unit area capacitance of 3.7 fF/?m2 were obtained at an applied electric field of 200 kV/cm.

  19. Mitigation of energetic electrons in the magnetosphere by amplified whistler wave under double cyclotron resonances

    NASA Astrophysics Data System (ADS)

    Kuo, S. P.

    2008-10-01

    An optimal approach reducing the population of MeV electrons in the magnetosphere is presented. Under a double resonance condition, whistler wave is simultaneously in cyclotron resonance with keV and MeV electrons. The injected whistler waves is first amplified by the background keV electrons via loss-cone negative mass instability to become effective in precipitating MeV electrons via cyclotron resonance elevated chaotic scattering. The numerical results show that a small amplitude whistler wave can be amplified by more than 25 dB. The amplification factor reduces only about 10 dB with a 30 dB increase of the initial wave intensity. Use of an amplified whistler wave to scatter 1.5 MeV electrons from an initial pitch angle of 86.5°to a pitch angle <50° is demonstrated. The ratio of the required wave magnetic field to the background magnetic field is calculated to be about 8×10-4.

  20. High-Dose Hypofractionated Proton Beam Radiation Therapy Is Safe and Effective for Central and Peripheral Early-Stage Non-Small Cell Lung Cancer: Results of a 12-Year Experience at Loma Linda University Medical Center

    SciTech Connect

    Bush, David A., E-mail: dbush@llu.edu [Department of Radiation Oncology, Loma Linda University Medical Center, Loma Linda, California (United States); Cheek, Gregory [Department of Pulmonary Medicine, Loma Linda University Medical Center, Loma Linda, California (United States); Zaheer, Salman; Wallen, Jason [Department of Thoracic Surgery, Loma Linda University Medical Center, Loma Linda, California (United States); Mirshahidi, Hamid [Department of Medical Oncology, Loma Linda University Medical Center, Loma Linda, California (United States); Katerelos, Ari; Grove, Roger; Slater, Jerry D. [Department of Radiation Oncology, Loma Linda University Medical Center, Loma Linda, California (United States)

    2013-08-01

    Purpose: We update our previous reports on the use of hypofractionated proton beam radiation therapy for early-stage lung cancer patients. Methods and Materials: Eligible subjects had biopsy-proven non-small cell carcinoma of the lung and were medically inoperable or refused surgery. Clinical workup required staging of T1 or T2, N0, M0. Subjects received hypofractionated proton beam therapy to the primary tumor only. The dose delivered was sequentially escalated from 51 to 60 Gy, then to 70 Gy in 10 fractions over 2 weeks. Endpoints included toxicity, pulmonary function, overall survival (OS), disease-specific survival (DSS), and local control (LC). Results: One hundred eleven subjects were analyzed for treatment outcomes. The patient population had the following average characteristics; age 73.2 years, tumor size 3.6 cm, and 1.33 L forced expiratory volume in 1 second. The entire group showed improved OS with increasing dose level (51, 60, and 70 Gy) with a 4-year OS of 18%, 32%, and 51%, respectively (P=.006). Peripheral T1 tumors exhibited LC of 96%, DSS of 88%, and OS of 60% at 4 years. Patients with T2 tumors showed a trend toward improved LC and survival with the 70-Gy dose level. On multivariate analysis, larger tumor size was strongly associated with increased local recurrence and decreased survival. Central versus peripheral location did not correlate with any outcome measures. Clinical radiation pneumonitis was not found to be a significant complication, and no patient required steroid therapy after treatment for radiation pneumonitis. Pulmonary function was well maintained 1 year after treatment. Conclusions: High-dose hypofractionated proton therapy achieves excellent outcomes for lung carcinomas that are peripherally or centrally located. The 70-Gy regimen has been adopted as standard therapy for T1 tumors at our institution. Larger T2 tumors show a trend toward improved outcomes with higher doses, suggesting that better results could be seen with intensified treatment.

  1. Long-term results of high-dose conformal radiotherapy for patients with medically inoperable T1-3N0 non-small-cell lung cancer: Is low incidence of regional failure due to incidental nodal irradiation?

    SciTech Connect

    Chen Ming [Department of Radiation Oncology, University of Michigan Health System, Ann Arbor, MI (United States); Hayman, James A. [Department of Radiation Oncology, University of Michigan Health System, Ann Arbor, MI (United States); Haken, Randall K. ten [Department of Radiation Oncology, University of Michigan Health System, Ann Arbor, MI (United States); Tatro, Daniel [Department of Radiation Oncology, University of Michigan Health System, Ann Arbor, MI (United States); Fernando, Shaneli [Department of Radiation Oncology, Veterans Administration Medical Center, Ann Arbor, MI (United States); Kong, F.-M. [Department of Radiation Oncology, University of Michigan Health System, Ann Arbor, MI (United States) and Department of Radiation Oncology, Veterans Administration Medical Center, Ann Arbor, MI (United States)]. E-mail: fengkong@med.umich.edu

    2006-01-01

    Purpose: To report the results of high-dose conformal irradiation and examine incidental nodal irradiation and nodal failure in patients with inoperable early-stage non-small-cell lung cancer (NSCLC). Methods and Materials: This analysis included patients with inoperable CT-staged T1-3N0M0 NSCLC treated on our prospective dose-escalation trial. Patients were treated with radiation alone (total dose, 63-102.9 Gy in 2.1-Gy daily fractions) with a three-dimensional conformal technique without intentional nodal irradiation. Bilateral highest mediastinal and upper/lower paratracheal, prevascular and retrotracheal, sub- and para-aortic, subcarinal, paraesophageal, and ipsilateral hilar regions were delineated individually. Nodal failure and doses of incidental irradiation were studied. Results: The potential median follow-up was 104 months. For patients who completed protocol treatment, median survival was 31 months. The actuarial overall survival rate was 86%, 61%, 43%, and 21% and the cause-specific survival rate was 89%, 70%, 53%, and 35% at 1, 2, 3, and 5 years, respectively. Weight loss (p = 0.008) and radiation dose in Gy (p = 0.013) were significantly associated with overall survival. In only 22% and 13% of patients examined did ipsilateral hilar and paratracheal (and subaortic for left-sided tumor) nodal regions receive a dose of {>=}40 Gy, respectively. Less than 10% of all other nodal regions received a dose of {>=}40 Gy. No patients failed initially at nodal sites. Conclusions: Radiation dose is positively associated with overall survival in patients with medically inoperable T1-3N0 NSCLC, though long-term results remain poor. The nodal failure rate is low and does not seem to be due to high-dose incidental irradiation.

  2. Non-linear effects in electron cyclotron current drive applied for the stabilization of neoclassical tearing modes

    NASA Astrophysics Data System (ADS)

    Ayten, B.; Westerhof, E.; the ASDEX Upgrade Team

    2014-07-01

    Due to the smallness of the volumes associated with the flux surfaces around the O-point of a magnetic island, the electron cyclotron power density applied inside the island for the stabilization of neoclassical tearing modes (NTMs) can exceed the threshold for non-linear effects as derived previously by Harvey et al (1989 Phys. Rev. Lett. 62 426). We study the non-linear electron cyclotron current drive (ECCD) efficiency through bounce-averaged, quasi-linear Fokker-Planck calculations in the magnetic geometry as created by the islands. The calculations are performed for the parameters of a typical NTM stabilization experiment on ASDEX Upgrade. A particular feature of these experiments is that the rays of the EC wave beam propagate tangential to the flux surfaces in the power deposition region. The calculations show significant non-linear effects on the ECCD efficiency, when the ECCD power is increased from its experimental value of 1 MW to a larger value of 4 MW. The nonlinear effects are largest in the case of locked islands or when the magnetic island rotation period is longer than the collisional time scale. The non-linear effects result in an overall reduction of the current drive efficiency for this case with absorption of the EC power on the low-field side of the electron cyclotron resonance layer. As a consequence of the non-linear effects, also the stabilizing effect of the ECCD on the island is reduced from linear expectations.

  3. Medical genetics

    SciTech Connect

    Jorde, L.B.; Carey, J.C.; White, R.L.

    1995-10-01

    This book on the subject of medical genetics is a textbook aimed at a very broad audience: principally, medical students, nursing students, graduate, and undergraduate students. The book is actually a primer of general genetics as applied to humans and provides a well-balanced introduction to the scientific and clinical basis of human genetics. The twelve chapters include: Introduction, Basic Cell Biology, Genetic Variation, Autosomal Dominant and Recessive Inheritance, Sex-linked and Mitochondrial Inheritance, Clinical Cytogenetics, Gene Mapping, Immunogenetics, Cancer Genetics, Multifactorial Inheritance and Common Disease, Genetic Screening, Genetic Diagnosis and Gene Therapy, and Clinical Genetics and Genetic Counseling.

  4. Medical Instrumentation

    NSDL National Science Digital Library

    2014-09-18

    Students learn about the sorts of devices designed by biomedical engineers and the many other engineering specialties that are required in their design of medical diagnostics, therapeutic aids, surgical devices and procedures, and replacement parts. They discuss the special considerations that must be made when dealing with the human body, such as being minimally invasive, biocompatible, keeping sterile, lightweight, corrosion resistant, long lasting and electrically safe. They also explore how "form fits function." Students gain an appreciation for the amazing devices that improve our quality of life. This lesson serves as a starting point for students to begin to ponder how the medical devices in their everyday lives work.

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

    SciTech Connect

    Pal, Gautam, E-mail: gautam.pal@vecc.gov.in; DuttaGupta, Anjan; Chakrabarti, Alok [Variable Energy Cyclotron Centre, I/AF Bidhannagar, Kolkata 700064 (India)

    2014-07-15

    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.

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

    SciTech Connect

    Bailey, J.D. [Oak Ridge National Lab., TN (United States)]|[Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)

    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.

  7. Medical Applications

    NASA Astrophysics Data System (ADS)

    Schieck, Hans Paetz Gen.

    The recent progress in medical imaging techniques such as magnetic-resonance imaging (nmr or mri), computer tomography (CT with X-rays), and positron-emission tomography (PET scanning using short-lived radioactive nuclei) has been impressive. Two areas where diagnostic tools lacked behind have been tomography of the blood vessels of the brain and of the bronchi.

  8. arXiv:cond-mat/9604010v11Apr1996 Vortex Dynamics in Superfluids: Cyclotron Type Motion

    E-print Network

    Niu, Qian

    arXiv:cond-mat/9604010v11Apr1996 Vortex Dynamics in Superfluids: Cyclotron Type Motion E. Demircan1. The natural motion of the vortex is of cyclotron type, whose frequency is found to be on the order of phonon foreign particles into the vortex core can reduce the cyclotron frequency and make the cyclotron motion

  9. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 27, NO. 2, APRIL 1999 445 Cyclotron-Resonance-Maser Arrays

    E-print Network

    Jerby, Eli

    IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 27, NO. 2, APRIL 1999 445 Cyclotron-Resonance-Maser Arrays Eli Jerby, Amit Kesar, Michael Korol, Li Lei, and Vladimir Dikhtyar Abstract-- The cyclotron-resonance-maser--Active antennas, active arrays, cyclotron radia- tion, cyclotron resonance, masers, microwave generation. I

  10. Laboratory and cyclotron requirements for PET research

    SciTech Connect

    Schlyer, D.J.

    1993-06-01

    This report describes four types of PET facilities: Clinical PET with no radionuclide production; clinical PET with a small accelerator; clinical PET with research support; and research PET facilities. General facility considerations are also discussed.

  11. Nonlinear effects of ion cyclotron heating of bounded plasmas

    Microsoft Academic Search

    J. M. Kindel; R. M. Martinez; A. T. Lin; J. M. Dawson

    1981-01-01

    An investigation of space charge effects associated with moving ions across dc magnetic field lines due to ion cyclotron heating is investigated. Within an electrostatic approximation, an inductive electric field is imposed across a highly inhomogeneous plasma. Two and one-half dimensional particle simulations examine this problem when electron motion is allowed along but not across the magnetic field. Finite parallel

  12. Nonlinear effects of ion cyclotron heating of bounded plasmas

    Microsoft Academic Search

    J. M. Kindel; A. T. Lin; J. M. Dawson; R. M. Martinez

    1981-01-01

    An investigation of space charge effects associated with moving ions across dc magnetic field lines due to ion cyclotron heating is investigated. Within an electrostatic approximation, an inductive electric field is imposed across a highly inhomogeneous plasma. Two and one-half dimensional particle simulations examine this problem when electron motion is allowed along but not across the magnetic field. Finite k∥

  13. Stripping extraction of positive ions from a cyclotron

    Microsoft Academic Search

    Jasna L. Ristic-Djurovic

    2001-01-01

    In a multipurpose cyclotron, it is convenient to use stripping extraction to extract selected positive ions in addition to the usual extraction by stripping of negative ions. The ions are specified as positive or negative according to the sign of their charge during acceleration. After stripping, positive ions travel not only through the pole edge magnetic field gradient, as is

  14. Numerical simulation of unconstrained cyclotron resonant maser emission

    NASA Astrophysics Data System (ADS)

    Speirs, D. C.; Gillespie, K. M.; Ronald, K.; McConville, S. L.; Phelps, A. D. R.; Cross, A. W.; Bingham, R.; Kellett, B. J.; Cairns, R. A.; Vorgul, I.

    2014-05-01

    When a mainly rectilinear electron beam is subject to significant magnetic compression, conservation of magnetic moment results in the formation of a horseshoe shaped velocity distribution. It has been shown that such a distribution is unstable to cyclotron emission and may be responsible for the generation of Auroral Kilometric Radiation (AKR) -an intense rf emission sourced at high altitudes in the terrestrial auroral magnetosphere. PiC code simulations have been undertaken to investigate the dynamics of the cyclotron emission process in the absence of cavity boundaries with particular consideration of the spatial growth rate, spectral output and rf conversion efficiency. Computations reveal that a well-defined cyclotron emission process occurs albeit with a low spatial growth rate compared to waveguide bounded simulations. The rf output is near perpendicular to the electron beam with a slight backward-wave character reflected in the spectral output with a well defined peak at 2.68GHz, just below the relativistic electron cyclotron frequency. The corresponding rf conversion efficiency of 1.1% is comparable to waveguide bounded simulations and consistent with the predictions of kinetic theory that suggest efficient, spectrally well defined radiation emission can be obtained from an electron horseshoe distribution in the absence of radiation boundaries.

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

    Microsoft Academic Search

    Lee A. Berry; S. M. Gorbatkin

    1995-01-01

    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

  16. Undriven periodic plasma oscillation in electron cyclotron resonance Ar plasma

    Microsoft Academic Search

    Pyung-Woo Lee; Sang-Won Lee; Hong-Young Chang

    1996-01-01

    We report experimental observation of periodic oscillation in a steady state electron cyclotron resonance argon plasma that is not driven by extra periodic forces. We interpret the oscillation according to the predator-prey model, which is a nonlinear plasma-neutral coupling in the plasma production region. The oscillation is observed in a narrow plasma parameter window and is evidence for neutral density

  17. Status of the Calcultta K500 superconducting cyclotron project

    Microsoft Academic Search

    2001-01-01

    The superconducting cyclotron under construction at this Center has Kbend=520 and Kfoc=160. Several parts of the main magnet frame have already been machined. They are undergoing inspection tests at the vendor's site. Trial windings on a full-scale dummy bobbin are going on to perfect the techniques using an elaborate superconducting coil winding set up at VECC. Fabrication of the RF

  18. Developing the Chalk River Superconducting Cyclotron for operation in ?-mode

    Microsoft Academic Search

    J. A. Hulbert; X.-H. Zhou

    1991-01-01

    The Chalk River Superconducting Cyclotron operates in two RF modes. In the ?-mode, the voltages on the four dees move in opposition in adjacent dees, giving rise to high RF surface currents in the cavity wall under the magnetic hills, and to vertical asymmetries in the dee excitation. Studies on a half-scale RF model of the accelerating cavity have confirmed

  19. RF cavity simulations for superconducting cyclotron C400

    NASA Astrophysics Data System (ADS)

    Jongen, Y.; Abs, M.; Kleeven, W.; Zaremba, S.; Glazov, A. A.; Gurskiy, S. V.; Karamyshev, O. V.; Karamysheva, G. A.; Morozov, N. A.

    2011-07-01

    Compact superconducting isochronous cyclotron C400 [ 1] has been designed at IBA (Belgium) in collaboration with the JINR (Dubna). This cyclotron will be the first cyclotron in the world capable of delivering protons, carbon and helium ions for therapeutic use. 12C6+ and 4He2+ ions will be accelerated to 400 MeV/u energy and extracted by electrostatic deflector, H{2/+} ions will be accelerated to the energy of 265 MeV/u and extracted by stripping. It is planned to use two normal conducting RF cavities for ion beam acceleration in the cyclotron C400. Computer model of the double gap delta RF cavity with 4 stems was developed in the general-purpose simulation software CST STUDIO SUITE. Necessary resonant frequency and increase of the voltage along the gaps were achieved. Optimization of the RF cavity parameters leads us to the cavity with quality factor about 14000, RF power dissipation is equal to about 50 kW per cavity.

  20. Recent developments at the Gustaf Werner cyclotron and CELSIUS

    Microsoft Academic Search

    D. Reistad

    1993-01-01

    The Gustaf Werner cyclotron, which usually operates in isochronous mode, is used as a synchrocyclotron for high energy protons. In addition to its internal PIG ion source, it has been equipped with two external ion sources, an ECR source for heavy ions and a source for polarized protons and deuterons. The CELSIUS ring is used for intermediate-energy physics with thin

  1. Status report of the clinical cyclotron facility in Seattle

    Microsoft Academic Search

    R. Risler; A. Z. Diaz; R. Emery; J. Jacky; G. E. Laramore; D. Reid

    2001-01-01

    The clinical cyclotron facility in Seattle continues to provide beams for neutron therapy and PET isotope production. Over 2000 patients have so far been treated using an isocentric gantry with multi-leaf collimator. Downtime remains below 2%. A new therapy control system has been in operation for nearly two years now and works efficiently and reliably. Developments to extend the therapeutic

  2. Vacuum measurements of the K500 cyclotron accelerator chamber

    Microsoft Academic Search

    M. L. Mallory; P. S. Miller; J. Kuchar; E. D. Hudson

    1986-01-01

    To evaluate the effectiveness of the unique internal cryopumping system, the pressure in the K500 superconducting cyclotron was measured as a function of radius for various gas flow rates emanating from the internal PIG source. For the test, a nude ion gauge with vertical dimension less than 2.3 cm was built and mounted on the internal beam probe. The effect

  3. An Intense Alpha Ion Source for INRS Cyclotron

    Microsoft Academic Search

    L. X. Chen; Chen Mao-bei

    1985-01-01

    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.

  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. Development of the third generation electron cyclotron resonance ion source

    Microsoft Academic Search

    C. M. Lyneis; Z. Q. Xie; C. E. Taylor

    1998-01-01

    The LBNL third generation electron cyclotron resonance (ECR) ion source has progressed from a concept to the fabrication of a full scale prototype superconducting magnet structure. This new ECR ion source will combine the recent ECR ion source techniques that significantly enhance the production of high charge state ions. The design includes a plasma chamber made from aluminum to provide

  6. Lifetime measurements of electron-cyclotron-resonance-heated electrons

    Microsoft Academic Search

    H. Boehmer; H. Goede; S. Talmadge

    1985-01-01

    The lifetime of energetic electrons generated via second harmonic electron-cyclotron-resonance heating in a symmetric magnetic mirror configuration is investigated experimentally. The decay time is observed to be as much as a factor of 4 shorter than the value calculated for the most rapid classical loss mechanism, Coulomb drag. The nonclassical loss component is shown to be induced by the microwave

  7. Ion thruster with electron cyclotron resonance microwave discharge

    Microsoft Academic Search

    Hitoshi Kuninaka; Satoshi Ichimura; Kyoichi Kuriki; Yasuo Horiuchi

    1992-01-01

    The electron cyclotron resonance plasma source is attractive for application to the ion thruster system because of electrodeless discharge and system downsizing. The internal probing in the discharge chamber was performed in order to improve the performance of the plasma source and investigate the plasma generating mechanism. High energy electrons were modified to be trapped and oscillate in an arched

  8. Electron Cyclotron Heating at 0.5 T in HSX

    Microsoft Academic Search

    J. N. Talmadge; A. Almagri; D. T. Anderson; F. S. B. Anderson; S. P. Gerhardt; V. Sakaguchi; J. Shafii; R. J. Vernon; T. S. Bigelow; K. M. Likin

    1999-01-01

    The first plasma experiments at 0.5 T in HSX will use a 28 GHz, 200 kW gyrotron to launch the extraordinary mode at the second harmonic of the electron cyclotron frequency. The status of the gyrotron, power supply and transmission line will be briefly summarized. An ellipsoidal mirror is being fabricated to minimize the spot size on the plasma axis.

  9. Continuous Energy Monitor for the External Beam of a Cyclotron

    Microsoft Academic Search

    J. A. Northrop; R. H. Stokes

    1958-01-01

    A simpie scintillation counter system is described which monitors the ; average energy of particles in the external beam of a cyclotron and ; simultaneously serves as a current integrator. Energy charges are continuously ; presented on a chart recorder, thus allowing the machine energy to be held ; constant to a high degree of accuracy over exended runs. In

  10. Propagation of electromagnetic ion cyclotron wave energy in the magnetosphere

    Microsoft Academic Search

    T. M. Loto'aniu; B. J. Fraser; C. L. Waters

    2005-01-01

    Recent satellite and conjugate observations of Pc 1 electromagnetic ion cyclotron (EMIC) waves have cast doubt on the validity of the long-standing bouncing wave packet (BWP) model that describes their propagation in the magnetosphere. A study was undertaken using the Combined Release and Radiation Effects Satellite (CRRES) E and B field data to further the understanding of the propagation characteristics

  11. Laboratory modeling of nonstationary processes in space cyclotron masers

    Microsoft Academic Search

    A. Vodop'yanov; S. Golubev; A. Demekhov; V. Zorin; D. Mansfel'D; S. Razin; V. Trakhtengerts

    2006-01-01

    Results are presented from laboratory modeling of the dynamics of space cyclotron masers Quasi-periodical bursts of electromagnetic radiation accompanied by the precipitation of energetic electrons from the non-equilibrium plasma of an ECR discharge in a mirror magnetic trap have been registered The study of the microwave plasma emission and the energetic electrons precipitated from the trap shows that the precipitation

  12. 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)

  13. Cyclotron waves in a non-neutral plasma column

    SciTech Connect

    Dubin, Daniel H. E. [Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)

    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.

  14. 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.

  15. Electromagnetic ion cyclotron waves stimulated by modest magnetospheric compressions

    Microsoft Academic Search

    B. J. Anderson; D. C. Hamilton

    1993-01-01

    The relationship between sudden impulses and enhancements or onset of Pc 1 at high-latitude ground stations is well established. It has been proposed that increased hot proton temperature anisotropy resulting from convection during magnetospheric compression is responsible for the enhancement in Pc 1 emissions via generation of electromagnetic ion cyclotron (EMIC) waves in the dayside outer equatorial magnetosphere. The authors

  16. Ion heating by strong electrostatic ion cyclotron turbulence

    Microsoft Academic Search

    R. L. Lysak; M. K. Hudson; M. Temerin

    1980-01-01

    A theory of ion heating due to electrostatic ion cyclotron (EIC) waves in the auroral zone is presented. Due to the slowly convecting nature of the EIC mode, quasi-linear plateau formation cannot stabilize the waves, and growth occurs until the nonlinear mechanisms of ion resonance broadening and electron trapping provide saturation. The large amplitude and coherent nature of the resulting

  17. Ion-cyclotron-resonance-heated conics: Theory and observations

    Microsoft Academic Search

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

    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

  18. The Electron Cyclotron Maser--An Historical Survey

    Microsoft Academic Search

    J. L. Hirshfield; V. L. Granatstein

    1977-01-01

    It has taken nearly twenty years for practical development of the electron cyclotron maser. The initial theoretical notions were put forward by R. Q. Twiss in 1958, but the first clear experimental demonstration did not take place until 1964. Today, in the USSR, these devices are being built which deliver kilowatt-level CW power at submillimeter wavelengths with high efficiency. This

  19. 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. PMID:24954679

  20. 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)