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. BEST medical radioisotope production cyclotrons

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  3. Novel compact superconducting cyclotron for medical applications

    NASA Astrophysics Data System (ADS)

    Dey, Malay Kanti; Gupta, Anjan Dutta; Chakrabarti, Alok

    2013-04-01

    A new design is presented for a superconducting-coil-based compact cyclotron, which has many practical benefits over conventional superconducting cyclotrons. Unlike in conventional superconducting cyclotrons, an iron yoke and poles have been avoided in this design and the azimuthally varying field is generated by superconducting sector coils. Housing the superconducting sector coils and circular coils in a single cryostat has resulted in an ultralight 25 MeV proton cyclotron weighing about 2000 kg. Further, the sector coils and the main coils are fed by independent power supplies, which allow flexibility of operation through on-line magnetic field trimming. The engineering considerations, focused on making the cyclotron ideally suited to medical applications, are described in detail.

  4. 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.

  5. 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.

  6. Nationwide survey on the operational status of medical compact cyclotrons in Japan.

    PubMed

    Fujibuchi, Toshioh; Yamaguchi, Ichiro; Watanabe, Hiroshi; Kimura, Ken-ichi; Tanaka, Shinji; Kida, Tetsuo; Nagaoka, Hiroaki

    2009-07-01

    The management of induced radioactivity of the cyclotron itself and structures is an important issue in decommissioning of medical compact cyclotrons. To obtain basic data on the actual operational conditions of cyclotrons, we performed nationwide survey. The actual beam current was about half of the maximum beam current indicated in the official permits for cyclotron operation. The actual operating time was about 10% of the maximum operating time indicated in the official permits. The average daily radioactive-nuclide ((18)F) production was only 10% of the allowed maximum quantity. From these results, it became clear that the induced radioactivity of a cyclotron and its concrete structures based on the maximum beam current and the maximum operating time may be overestimated. These basic data are expected to be useful for a realistic evaluation and helpful in establishing a rational regulation in regard to radioactive waste control for decommissioning of medical cyclotrons. PMID:20821110

  7. 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

  8. 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

  9. 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.

  10. 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…

  11. 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.

  12. 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

  13. 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

  14. 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

  15. The Method of Small-Volume Expansions for Medical Imaging

    E-print Network

    Ammari, Habib

    1 The Method of Small-Volume Expansions for Medical Imaging Habib Ammari1 and Hyeonbae Kang2 1@inha.ac.kr 1.1 Introduction Inverse problems in medical imaging are in their most general form ill with many medical imaging problems. The method relies on deriving asymptotics. Such asymptotics have been

  16. Progress report on the IBA-SHI small cyclotron for cancer therapy

    Microsoft Academic Search

    Y. Jongen; A. Laisné; W. Beeckman; J. P. Dufour; H. Marie; R. Verbruggen; H. Wollnik; N. Takahashi; S. Satoh; M. Sano; T. Takayama

    1993-01-01

    A proton therapy facility using a compact, high-field nonsuperconducting cyclotron was first presented by Ion Beam Applications (IBA) at the PTCOG meeting in June 1990. In December 1990, funding was secured to start the design of a prototype at IBA. In October 1991 a collaboration agreement was signed between IBA and Sumitomo Heavy Industries (SHI). The main features of this

  17. Radiation safety management of residual long-lived radioactivity distributed in an inner concrete wall of a medical cyclotron room.

    PubMed

    Yamaguchi, Ichiro; Kimura, Ken-ichi; Fujibuchi, Toshioh; Takahashi, Yasuyuki; Saito, Kyoko; Otake, Hidenori

    2011-07-01

    The depth distribution of residual long-lived radioactivity in the inner concrete wall of a medical cyclotron room was measured by assaying concrete cores. Seven long-lived radioactive nuclides ((46)Sc, (60)Co, (65)Zn, (134)Cs, (152)Eu, (22)Na and (54)Mn) were identified by gamma-ray spectrometry of the concrete samples. It was confirmed that the gamma-ray-emitting radionuclides induced by thermal neutrons through the (n, ?) reaction are dominant, and that the activity induced by thermal neutrons is greater at a depth of 10-30 cm, rather than at the surface of the concrete, and decreased exponentially beyond a depth of ~40 cm. Although the specific activity at the surface was greater than the clearance level for radioactive waste indicated in IAEA RS-G-1.7, the mean specific activities in the walls and floor were less than the clearance level. PMID:21498855

  18. An overview of copper radionuclides and production of 61Cu by proton irradiation of natZn at a medical cyclotron

    Microsoft Academic Search

    Pejman Rowshanfarzad; Mahsheed Sabet; Amir Reza Jalilian; Mohsen Kamalidehghan

    2006-01-01

    In this article, production methods and applications of copper radionuclides are overviewed with special attention toward 61Cu, due to its interesting nuclear properties. Selection of production parameters for 61Cu including: appropriate nuclear reaction, proton beam energy, target thickness and targetry method are discussed for NRCAM 30MeV medical cyclotron. 64Zn(p,?)61Cu was selected as the best reaction and 61Cu was produced by

  19. Computerizing a Small Medical Practice Trading Tranquility for Tranquilizers

    PubMed Central

    Adams, Richard C.

    1979-01-01

    The use of micro-computers in the solo or small group medical practice environment is a relatively recent development. This paper describes the development and initial field testing of such a system, first in a solo practice, then evolving to a small group. The hardware is briefly detailed, the evolution of the software package is described, the difficulties of implementation and the future plans for the system are all outlined. As the hardware becomes more economical and universally available, use of microcomputers will certainly become commonplace, even in the small office setting, and it offers exciting possibilities for the future.

  20. 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 ...

  1. Cyclotrons and positron emitting radiopharmaceuticals

    SciTech Connect

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

    1984-01-01

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

  2. 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

  3. 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

  4. Thoughts on Cataloging and Classification in a Small Medical Library

    PubMed Central

    Waller, Salvador B.

    1970-01-01

    This article is based on experience with small library collections. It is an effort to point out some of the problems in cataloging and classification, to arouse an interest in self-analysis on the part of the small library, and to offer some suggestions as to how the small institution can streamline techniques and economize on meager resources with no loss of value to the card catalog. It is recognized that the catalogs in many small libraries are unsuited for their tasks as a result of adhering to philosophies of larger institutions. The small institution has neither the need nor resources for such completeness in cataloging and classification. Deviation from standard rules is not advocated. However, consistency in treatment is advised and adherence in depth to standard rules is questioned. PMID:5411704

  5. Thoughts on cataloging and classification in a small medical library.

    PubMed

    Waller, S B

    1970-01-01

    This article is based on experience with small library collections. It is an effort to point out some of the problems in cataloging and classification, to arouse an interest in self-analysis on the part of the small library, and to offer some suggestions as to how the small institution can streamline techniques and economize on meager resources with no loss of value to the card catalog. It is recognized that the catalogs in many small libraries are unsuited for their tasks as a result of adhering to philosophies of larger institutions. The small institution has neither the need nor resources for such completeness in cataloging and classification. Deviation from standard rules is not advocated. However, consistency in treatment is advised and adherence in depth to standard rules is questioned. PMID:5411704

  6. The Use of Small Group Tutorials as an Educational Strategy in Medical Education

    ERIC Educational Resources Information Center

    Ferris, Helena

    2015-01-01

    Small group tutorials are an educational strategy that is growing in popularity in medical education. This is indicative of the movement from a traditional teacher centred approach to more student-centred learning, which is characterised by active participation and autonomous learning (Hedge et al, 2011). However, small group teaching is one of…

  7. JSW's baby cyclotron

    SciTech Connect

    Toda, Y.; Kaneda, Y.; Satoh, Y.; Suzukawa, I.; Yamada, T.

    1983-04-01

    Designed by The Japan Steel Works, Ltd., specially for installation in a hospital's medical department and nuclear research laboratory, '' JSW BABY CYCLOTRON '' has been developed to produce short-lived radioisotopes such as 11C, 13N, 15O and 18F. JSW's Baby Cyclotron has some design features. 1) Fixed energy and four sector azimuthally varying field. 2) Compact figure desired for hospital's nuclear medical department 3) A bitter type magnet yoke shielding activity 4) Simple control and operation 5) Easy maintenance without skilled personnel. Type BC105 (P:10MeV, d:5MeV), BC107 (P:10MeV, d:7MeV), BC168 (P:16MeV, d:8MeV) and BC1710 (P:17MeV, d:10MeV) are available according to required amount of radioisotopes. In our radioisotope production test, yield and purity of 11C, 13N, 15O and 18F are usable to clinical diagnosis.

  8. Cyclotron produced radiopharmaceuticals

    NASA Astrophysics Data System (ADS)

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

    2003-01-01

    Some of the cyclotron-produced radionuclides may serve as important materials for the production of radiopharmaceuticals. This lecture deals with basic information relating to various aspects of these compounds. In comparison with radionuclides/compounds used for non-medical purposes, radiopharmaceuticals are subject to a broader scale of regulations, both from the safety and efficacy point of view; besides that, there are both radioactive and medical aspects that must be taken into account for any radiopharmaceutical. According to the regulations and in compliance with general rules of work with radioactivity, radiopharmaceuticals should only be prepared/manufactured under special conditions, using special areas and special equipment and applying special procedures (e.g. sterilisation, disinfection, aseptic work). Also, there are special procedures for cleaning and maintenance. Sometimes the requirements for the product safety clash with those for the safety of the personnel; several examples of solutions pertaining to these cases are given in the lecture. Also, the specific role of cyclotron radiopharmaceuticals is discussed.

  9. Centrifugal extraction of highly enriched 123Te for the production of 123I at a cyclotron

    NASA Astrophysics Data System (ADS)

    Yu Sosnin, L.; Tcheltsov, A. N.

    1999-12-01

    The centrifugal enrichment of gram quantities of 99.9% 123Te by a non-steady-state separation method is described. The resulting highly enriched 123Te can be used for the production of the medical radionuclide 123I on a small cyclotron ( E<20 MeV). Results indicate that the non-steady-state separation can be effectively used for the enrichment of isotopes of other elements.

  10. 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.

  11. Medical Students Perceive Better Group Learning Processes when Large Classes Are Made to Seem Small

    PubMed Central

    Hommes, Juliette; Arah, Onyebuchi A.; de Grave, Willem; Schuwirth, Lambert W. T.; Scherpbier, Albert J. J. A.; Bos, Gerard M. J.

    2014-01-01

    Objective Medical schools struggle with large classes, which might interfere with the effectiveness of learning within small groups due to students being unfamiliar to fellow students. The aim of this study was to assess the effects of making a large class seem small on the students' collaborative learning processes. Design A randomised controlled intervention study was undertaken to make a large class seem small, without the need to reduce the number of students enrolling in the medical programme. The class was divided into subsets: two small subsets (n?=?50) as the intervention groups; a control group (n?=?102) was mixed with the remaining students (the non-randomised group n?100) to create one large subset. Setting The undergraduate curriculum of the Maastricht Medical School, applying the Problem-Based Learning principles. In this learning context, students learn mainly in tutorial groups, composed randomly from a large class every 6–10 weeks. Intervention The formal group learning activities were organised within the subsets. Students from the intervention groups met frequently within the formal groups, in contrast to the students from the large subset who hardly enrolled with the same students in formal activities. Main Outcome Measures Three outcome measures assessed students' group learning processes over time: learning within formally organised small groups, learning with other students in the informal context and perceptions of the intervention. Results Formal group learning processes were perceived more positive in the intervention groups from the second study year on, with a mean increase of ??=?0.48. Informal group learning activities occurred almost exclusively within the subsets as defined by the intervention from the first week involved in the medical curriculum (E-I indexes>?0.69). Interviews tapped mainly positive effects and negligible negative side effects of the intervention. Conclusion Better group learning processes can be achieved in large medical schools by making large classes seem small. PMID:24736272

  12. Composition and production rate of medical waste from a small producer in Greece.

    PubMed

    Graikos, Anastasios; Voudrias, Evangelos; Papazachariou, Athanasios; Iosifidis, Nikolaos; Kalpakidou, Maria

    2010-01-01

    The objective of this work was to determine the composition and production rate of medical waste from the health care facility of social insurance institute, a small waste producer in Xanthi, Greece. Specifically, produced medical waste from the clinical pathology (medical microbiology) laboratory, the X-ray laboratory and the surgery and injection therapy departments of the health facility was monitored for six working weeks. A total of 240 kg medical solid waste was manually separated and weighed and 330 L of liquid medical waste was measured and classified. The hazardous waste fraction (%w/w) of the medical solid waste was 91.6% for the clinical pathology laboratory, 12.9% for the X-ray laboratory, 24.2% for the surgery departments and 17.6% for the injection therapy department. The infectious waste fraction (%w/w) of the hazardous medical solid waste was 75.6% for the clinical pathology laboratory, 0% for the X-ray laboratory, 100% for the surgery departments and 75.6% for the injection therapy department. The total hazardous medical solid waste production rate was 64+/-15 g/patient/d for the clinical pathology laboratory, 7.2+/-1.6 g/patient/d for the X-ray laboratory, 8.3+/-5.1 g/patient/d for the surgery departments and 24+/-9 g/patient/d for the injection therapy department. Liquid waste was produced by the clinical pathology laboratory (infectious-and-toxic) and the X-ray laboratory (toxic). The production rate for the clinical pathology laboratory was 0.03+/-0.003 L/patient/d and for the X-ray laboratory was 0.06+/-0.006 L/patient/d. Due to the small amount produced, it was suggested that the most suitable management scheme would be to transport the hazardous medical waste, after source-separation, to the Prefectural Hospital of Xanthi to be treated with the hospital waste. Assuming this data is representative of other small medical facilities, medical waste production can be estimated for such facilities distributed around Greece. PMID:20156673

  13. 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…

  14. 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

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

    PubMed Central

    Brandon, Alfred N.

    1965-01-01

    This list of 358 books and 123 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:14308899

  16. Teaching ultrasound in developing countries: issues to consider when working in small medical facilities.

    PubMed

    Brown, Douglas L

    2014-03-01

    The author provides some suggestions for those considering travel to developing countries to provide training in ultrasound at small medical facilities. Issues discussed will include planning before the trip, personal safety and health while there, as well as equipment and travel issues. PMID:24901780

  17. [Occupational safety and health at small scale enterprises co-operating with a medical university].

    PubMed

    Taguchi, Yoto; Horie, Seichi; Tsutsui, Takao; Igisu, Hideki

    2002-06-01

    This descriptive study reports the results of a systematic survey on occupational safety and health hazards and risks to exposed workers at companies co-operating with a medical university, and investigates the effective methods for their management. Varieties of works at all these co-operating companies have been categorized into 14 types of businesses. The survey was performed in two-fold; an individual interview of managers and a comprehensive inspection of workshops, and a questionnaire to all workers (response rate 95.9%). All of the co-operating companies were small-scale enterprises with less than 50 employees. The occupational safety and health risks to be controlled were accidental contact with biomedical wastes, heat in the kitchen, laundry and boiler room, unfavorable ventilation at workplace close to medical facility, and physical fatigue of guards and janitors. A higher number of occupational health physicians and a higher rate of health examinations were observed compared to other small-scale enterprises in Japan. About 80% of all workers were conscious of working on the premises of medical facilities. To improve the occupational safety and health activities of co-operating companies, we propose the use of professionals at the medical university, the promotion of joint activities among the co-operating companies, and the strengthening of mutual connection and coordination between the co-operating companies and the medical university. PMID:12066587

  18. 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

  19. 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

  20. Implementing a Personalized Resource Management Program for a Small Medical Library by Using LinkOut

    Microsoft Academic Search

    Dorothy R. Kelly

    2006-01-01

    End users want easy access to electronic full-text articles from their desktops. This small medical library has implemented an easy and cost-effective resource management program to meet this user need. This column will describe the implementation, use, and maintenance of the National Library of Medicine's LinkOut, a personalized resource management program that provides immediate access to the library's online journal

  1. 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

  2. The networks from medical knowledge and clinical practice have small-world, scale-free, and hierarchical features

    NASA Astrophysics Data System (ADS)

    Tachimori, Yutaka; Iwanaga, Hiroaki; Tahara, Takashi

    2013-12-01

    Here, we constructed and analyzed a network (henceforth, “medical knowledge network”) derived from a commonly used medical text. We show that this medical knowledge network has small-world, scale-free, and hierarchical features. We then constructed a network from data from a hospital information system that reflected actual clinical practice and found that this network also had small-world, scale-free, and hierarchical features. Moreover, we found that both the diagnosis frequency distribution of the hospital network and the diagnosis degree distribution of the medical knowledge network obeyed a similar power law. These findings suggest that the structure of clinical practice may emerge from the mutual influence of medical knowledge and clinical practice, and that the analysis of a medical knowledge network may facilitate the investigation of the characteristics of medical practice.

  3. Improvement through Small Cycles of Change: Lessons from an Academic Medical Center Emergency Department.

    PubMed

    Arbune, Amit; Wackerbarth, Sarah; Allison, Penne; Conigliaro, Joseph

    2014-08-01

    This article describes the experiences of a quality improvement team that used small cycles of change to improve the emergency department (ED) of an academic medical center. The role of EDs in the provision of healthcare continues to increase in importance. ED bottlenecks contribute to long waits and diminished outcomes for ED patients as well as more system-wide issues, such as inefficiencies in inpatient admission processes. The purpose of this "ED Operational Efficiency Project" was to reduce lengths of stay (LOS) for low-acuity patients. The team used lean management techniques to both improve services and shift the ED culture to prioritize continuous quality improvement. The goal to reduce LOS by 30% was met as the result of several interrelated projects (or small cycles of change). Key lessons include monitoring metrics, communicating with teams and target populations, learning from initial failures, using small wins to increase momentum, and anchoring changes. PMID:25330898

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

    PubMed

    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 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. PMID:19177374

  5. 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

  6. 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

  7. 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

  8. Improvements and applications at NIRS cyclotron facility

    NASA Astrophysics Data System (ADS)

    Honma, T.; Hojo, S.; Miyahara, N.; Nemoto, K.; Sato, Y.; Suzuki, K.; Takada, M.; Yamada, S.; Kuramochi, Y.; Okada, T.; Hanagasaki, M.; Komatsu, K.; Ogawa, H.

    2001-12-01

    The NIRS-Chiba isochronous cyclotron has been working in routinely, and providing the stable beams for bio-medical studies and various kind of related experiments since 1975. The clinical trail of eye melanoma has been under continued. Recently two new beam lines were constructed in order to carry out the bio-physical study, and to produce the long-lived R.I.s for SPECT. Some progressive improvements, such as updating the magnetic-channel and development of a floating septum system, were performed for stable operation of the cyclotron. A brief review of the current status of the cyclotron and typical application of latest experiments in the various fields are described.

  9. 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

  10. 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

  11. 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.

  12. Rf for cyclotrons

    E-print Network

    Sigg, P K

    2006-01-01

    The following paper will give an overview of cyclotron-specific RF design: it will deal with classical RF structures (Dees), which are mostly based on a ?/4 or ?/2 coaxial line design, and extend to cavity concepts deviating from conventional cyclotron resonators. Such cavities usually can only be employed in Separated Sector Cyclotrons (SSCs), because their designs ask for more space for the RF cavities. Modelling methods, mechanical design and some results are also presented. Specific characteristics and requirements for RF power amplifiers are introduced; illustrated by two types of power amplifiers. Finally, basic concepts and prerequisites for control systems are presented.

  13. 88-Inch Cyclotron newsletter

    SciTech Connect

    Stokstad, R.

    1987-02-01

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

  14. Medical Record Clerk Training Program, Course of Study; Student Manual: For Medical Record Personnel in Small Rural Hospitals in Colorado.

    ERIC Educational Resources Information Center

    Community Health Service (DHEW/PHS), Arlington, VA. Div. of Health Resources.

    The manual provides major topics, objectives, activities and, procedures, references and materials, and assignments for the training program. The topics covered are hospital organization and community role, organization and management of a medical records department, international classification of diseases and operations, medical terminology,…

  15. 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.

  16. Small molecule discoidin domain receptor kinase inhibitors and potential medical applications.

    PubMed

    Li, Yupeng; Lu, Xiaoyun; Ren, Xiaomei; Ding, Ke

    2015-04-23

    Discoidin domain receptors (DDRs) are members of the transmembrane receptor tyrosine kinase (RTK) superfamily which are distinguished from others by the presence of a discoidin motif in the extracellular domain and their utilization of collagens as internal ligands. Two types of DDRs, DDR1 and DDR2, have been identified with distinct expression profiles and ligand specificities. These DDRs play important roles in the regulation of fundamental cellular process, such as proliferation, survival, differentiation, adhesion, and matrix remodeling. They have also been closely linked to a number of human diseases, including various fibrotic disorders, atherosclerosis, and cancer. As a consequence, DDRs have been considered as novel potential molecular targets for drug discovery and increasing efforts are being devoted to the identification of new small molecule inhibitors targeting the receptors. In this review, we offer a contemporary overview on the discovery of DDRs inhibitors and their potential medical application for the treatment of cancer and inflammation related disorders. PMID:25569119

  17. 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

  18. 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

  19. 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, James L. Voss Veterinary Medical Center College of Veterinary Medicine and Biomedical Sciences Colorado) at the Assistant Professor level in the Department of Clinical Sciences. Qualifications · DVM or equivalent

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

    PubMed

    Rogers, David E C; Brent, Alan C

    2006-01-01

    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. PMID:16364626

  1. Teaching medical ethics: problem-based learning or small group discussion?

    PubMed Central

    Heidari, Akram; Adeli, Seyyed-Hassan; Taziki, Sadegh-Ali; Akbari, Valliollahe; Ghadir, Mohammad-Reza; Moosavi-Movahhed, Seyyed-Majid; Ahangari, Roghayyeh; Sadeghi-Moghaddam, Parvaneh; Mirzaee, Mohammad-Rahim; Damanpak-Moghaddam, Vahid

    2013-01-01

    Lecture is the most common teaching method used in ethics education, while problem-based learning (PBL) and small group discussion (SGD) have been introduced as more useful methods. This study compared these methods in teaching medical ethics. Twenty students (12 female and 8 male) were randomly assigned into two groups. The PBL method was used in one group, and the other group was taught using the SGD method. Twenty-five open-ended questions were used for assessment and at the end of the course, a course evaluation sheet was used to obtain the students’ views about the advantages and disadvantages of each teaching method, their level of satisfaction with the course, their interest in attending the sessions, and their opinions regarding the effect of teaching ethics on students’ behaviors. The mean score in the PBL group (16.04 ± 1.84) was higher than the SGD group (15.48 ± 2.01). The satisfaction rates in the two groups were 3.00 ± 0.47 and 2.78 ± 0.83 respectively. These differences were not statistically significant. Since the mean score and satisfaction rate in the PBL group were higher than the SGD group, the PBL method is recommended for ethics education whenever possible. PMID:23908762

  2. Cyclotron Research and Applications

    NASA Astrophysics Data System (ADS)

    Mach, Rostislav

    2010-01-01

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

  3. A small portable proton exchange membrane fuel cell and hydrogen generator for medical applications.

    PubMed

    Adlhart, O J; Rohonyi, P; Modroukas, D; Driller, J

    1997-01-01

    Small, lightweight power sources for total artificial hearts (TAH), left ventricular assist devices (LVAD), and other medical products are under development. The new power source will provide 2 to 3 times the capacity of conventional batteries. The implications of this new power source are profound. For example, for the Heartmate LVAD, 5 to 8 hours of operation are obtained with 3 lb of lead acid batteries (Personal Communication Mr. Craig Sherman, Thermo Cardiosystems, Inc TCI 11/29/96). With the same weight, as much as 14 hours of operation appear achievable with the proton exchange membrane (PEM) fuel cell power source. Energy densities near 135 watt-hour/L are achievable. These values significantly exceed those of most conventional and advanced primary and secondary batteries. The improvement is mission dependent and even applies for the short deployment cited above. The comparison to batteries becomes even more favorable if the mission length is increased. The higher capacity requires only replacement of lightweight hydride cartridges and logistically available water. Therefore, when one spare 50 L hydride cartridge weighing 115 g is added to the reactant supply the energy density of the total system increases to 230 watt-hour/kg. This new power source is comprised of a hydrogen fueled, air-breathing PEM fuel cell and a miniature hydrogen generator (US Patent No 5,514,353). The fuel cell is of novel construction and differs from conventional bipolar PEM fuel cells by the arrangement of cells on a single sheet of ion-exchange membrane. The construction avoids the weight and volume penalty of conventional bipolar stacks. The hydrogen consumed by the fuel cell is generated load-responsively in the miniature hydrogen generator, by reacting calcium hydride with water, forming in the process hydrogen and lime. The generator is cartridge rechargeable and available in capacities providing up to several hundred watt-hours of electric power. PMID:9152494

  4. 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

  5. Radioactive nuclei for medical applications

    NASA Astrophysics Data System (ADS)

    Jastrz?bski, Jerzy

    2011-01-01

    The radioisotopes used for labeling the diagnostic and therapeutic radiopharmaceuticals are contemporaneously produced using neutrons in reactors and light charged particles from accelerators (cyclotrons). After the presentation of both methods the commercially available cyclotrons are reviewed. Some examples of the most popular medical radioisotopes are given. The new Radiopharmaceuticals Production and Research Centre at the University of Warsaw is presented.

  6. Fourier transform ion cyclotron resonance mass spectrometric detection of small Ca 2+ -induced conformational changes in the regulatory domain of human cardiac troponin C

    Microsoft Academic Search

    Fang Wang; Weiqun Li; Mark R. Emmett; Alan G. Marshall; David Corson; Brian D. Sykes

    1999-01-01

    Troponin C (TnC), a calcium-binding protein of the thin filament of muscle, plays a regulatory role in skeletal and cardiac\\u000a muscle contraction. NMR reveals a small conformational change in the cardiac regulatory N-terminal domain of TnC (cNTnC) on\\u000a binding of Ca2+ such that the total exposed hydrophobic surface area increases very slightly from 3090±86 Å2 for apo-cNTnC to 3108±71 Å2

  7. Decay of References to Web sites in Articles Published in General Medical Journals: Mainstream vs Small Journals

    PubMed Central

    Habibzadeh, P.

    2013-01-01

    Summary Background Over the last decade, Web sites (URLs) have been increasingly cited in scientific articles. However, the contents of the page of interest may change over the time. Objective To investigate the trend of citation to URLs in five general medical journals since January 2006 to June 2013 and to compare the trends in mainstream journals with small journals. Methods References of all original articles and review articles published between January 2006 and June 2013 in three regional journals – Archives of Iranian Medicine (AIM), Eastern Mediterranean Health Journal (EMHJ), and Journal of Postgraduate Medical Institute (JPMI) – and two mainstream journals – The Lancet and British Medical Journal (BMJ) – were reviewed. The references were checked to determine the frequency of citation to URLs as well as the rate of accessibility of the URLs cited. Results A total of 2822 articles was studied. Since January 2006 onward, the number of citations to URLs increased in the journals (doubling time ranged from 4.2 years in EMHJ to 13.9 years in AIM). Overall, the percentage of articles citing at least one URL has increased from 24% in 2006 to 48.5% in 2013. Accessibility to URLs decayed as the references got old (half life ranged from 2.2 years in EMHJ to 5.3 years in BMJ). The ratio of citation to URLs in the studied mainstream journals, as well as the ratio of URLs accessible were significantly (p<0.001) higher than the small medical journals. Conclusion URLs are increasingly cited, but their contents decay with time. The trend of citing and decaying URLs are different in mainstream journals compared to small medical journals. Decay of URL contents would jeopardize the accuracy of the references and thus, the body of evidence. One way to tackle this important obstacle is to archive URLs permanently. PMID:24454575

  8. 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.

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

    SciTech Connect

    Sambuu, Odmaa; Nanzad, Norov [Nuclear Research Center National University of Mongolia Ulaanbaatar (Mongolia)

    2009-03-31

    A 300 kW small medical reactor was designed to be used for boron neutron capture therapy (BNCT) at KAIST in 1996. 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.

  10. 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.

  11. Terrestrial kilometric radiation - The cyclotron theory

    NASA Technical Reports Server (NTRS)

    Melrose, D. B.; Hewitt, R. G.; Ronnmark, K. G.

    1982-01-01

    It is shown that electrons in inverted V events can cause direct, amplified cyclotron emission (x-mode radiation) above the cutoff frequency, and the growth rate of the waves is calculated by using inverted V electron event observations as the inputs of a numerical code. Calculation results exhibiting wave growth are adduced as evidence for the cyclotron interpretation of terrestrial kilometric radiation (TKR). It is speculated that the specific electron distribution features which generate TKR should disappear in much less than a second, and should therefore not be observable in particle data averaged over more than one second. The basic electron distribution feature that gives rise to TKR is a one-sided loss cone anisotropy in which upward moving electrons with small pitch angles are missing. The features causing large growth rates may be due to the effects of the parallel electric field.

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

    NASA Astrophysics Data System (ADS)

    Jones, D.

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

  13. Automatic and manual indexing performance in a small file of medical literature.

    PubMed Central

    Boyce, B; Lockard, M

    1975-01-01

    A test of the performance of an automatic indexing procedure based on the processing of the full text of medical journal articles shows results comparable to those achieved using Excerpta Medica and MEDLARS manual indexing. A file of nineteen documents was partitioned by sixteen questions, for each of which two search strategies in each indexing language were formulated. The results were compared to ideal answers chosen by a fourth-year medical student who read the entire file and posed the questions. PMID:1191823

  14. 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…

  15. Development and implementation of a secure, integrated management system for medical images and electronic clinical records for small hospitals.

    PubMed

    Pereira, Javier; Castro, Antonio F; Perez, Juan L; Novoa, Francisco J; Vázquez, Jose M; Teijeiro, Jorge; Pazos, Alejandro; Ezquerra, Norberto

    2007-06-01

    The field of Medical Informatics is currently experiencing increasing demands for new models of the Picture Archiving and Communication Systems (PACS) and Digital Imaging and Communications in Medicine (DICOM) protocols. Despite of the considerable advantages of current systems, implementation in hospitals is remarkably slow, due primarily to difficulties in integration and relatively high costs. Even though the success of DICOM standards has greatly contributed to the development of PACS, many hospitals remain unable to support it or to make full use of its potential because various imaging modalities in use at these sites generate images that cannot be stored in the PACS and cannot be managed in a centralized manner without DICOM standardization modules. Furthermore, the imaging modalities being used in such smaller centers are expensive and unlikely to be replaced, making DICOM compliance untenable. With this in mind, this paper describes the design, development, and implementation of a management system for medical diagnostic imaging, based on the DICOM standard and adapted to the needs of a small hospital. The system is currently being implemented in the San Rafael Hospital at A Coruna in Spain, and integrated with the existing hospital information system (HIS). We have studied the networking infrastructure of the hospital and its available image generation devices, and have subsequently carried out a series of measurements including transmission times, image file size, compression ratios, and many others that allow us to analyze the behavior of the system. Results obtained from these investigations demonstrate both the flexibility of using such a "small-hospital" DICOM-based framework as well as the relative cost-effectiveness of the system. In this regard, the approach, described herein, might serve as a model for other small, and possibly mid-sized, medical centers. PMID:17603833

  16. Increasing access to medical oncology consultation in older patients with stage II-IIIA non-small-cell lung cancer

    Microsoft Academic Search

    Jue Wang; Yong Fang Kuo; Jean Freeman; James S. Goodwin

    2008-01-01

    Background  Resectable non-small-cell lung cancer (NSCLC) was once considered a disease whose sole therapy was surgical resection. Therefore\\u000a it was managed by surgeons. However, with growing evidence of the benefit of adjuvant chemotherapy, such patients should also\\u000a be evaluated by a medical oncologist.\\u000a \\u000a \\u000a \\u000a Methods  Using data from the Surveillance, Epidemiology, and End Results (SEER) Program, we identified 3,196 patients 66–85 years of\\u000a age

  17. 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.

  18. 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.

  19. Electron Cyclotron Waves

    SciTech Connect

    Hoekzema, J.A. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH (Germany)

    2004-03-15

    An introduction is given to plasma heating and current drive with electromagnetic waves in the electron cyclotron range of frequencies, with emphasis on application in tokamak plasmas. Propagation and absorption of these waves is generally well described by linear theory, a short overview of which is given. Electron cyclotron absorption is limited to regions of the plasma where the gyromotion of electrons is in resonance with the wave frequency and can be well localised, even in smaller experiments. Apart from being able to provide global heating and non-inductive current drive, ECRH and ECCD are therefore important tools to study and manipulate locally instabilities in the plasma which are electron temperature gradient or current driven. Important potential control applications in a reactor grade plasma include mode stabilisation to prevent disruptions, transport manipulation (e.g. to maintain burn) and correction of the bootstrap current profile. The use of EC waves in major tokamak experiments has in the past been restricted due to the lack of suitable sources. These sources are, however, now rapidly becoming available.

  20. 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.

  1. Evaluation of a Small-Group Support Program for First-Year Medical Students.

    ERIC Educational Resources Information Center

    Ficklin, Fred L.; And Others

    1983-01-01

    A small-group program established to provide advice and support in areas of stress for freshman students at Indiana University School of Medicine is described. Two objectives of the program were met: increasing intraclass student communication and support and decreasing student anonymity. (MLW)

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

    Microsoft Academic Search

    David E. C. Rogers; Alan C. Brent

    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

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

    Microsoft Academic Search

    David E. C.. Rogers; Alan C. Brent

    2006-01-01

    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

  4. Nonlinear cyclotron harmonic absorption

    SciTech Connect

    Seol, Jae Chun [National Fusion Research Institute, Yuseong, Daejeon 555-333 (Korea, Republic of); Hegna, C. C.; Callen, J. D. [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706-1609 (United States)

    2009-05-15

    Nonlinear oscillations of particle's energy occur when a particle stays in a resonance zone. In this work, we found that collisionless heating of particles occurs when they pass the microwave beam at first, second, and third harmonic resonances. It is found that the net energy gain of particles from the microwaves is inversely proportional to the wave frequency. It is also found that the net energy gain is dependent on the microwave beam width. The energy gain of particles from a single pass through a resonance zone has been formulated analytically. A numerical calculation has been performed and the results are in good agreement with the analytic calculation. Both analytic and numerical calculations show a strong frequency dependence and a beam width dependence of nonlinear cyclotron resonance heating.

  5. 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.

  6. 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.

  7. 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?

  8. Medical implications of understanding the functions of human small heat shock proteins.

    PubMed

    Mymrikov, Evgeny V; Haslbeck, Martin

    2015-06-01

    Small heat shock proteins (sHsps) are ubiquitous molecular chaperones that are implicated in a variety of diseases. Upon stress, they stabilize unfolding proteins and prevent them from aggregating. However, under physiological conditions without severe stress, some sHsps interact with other proteins. In a perspective view, their ability to bind specific client proteins might allow them to fine-tune the availability of the client for other, client-dependent cellular processes. Additionally, some sHsps seem to interact with specific co-chaperones. These co-chaperones are usually part of large protein machineries that are functionally modulated upon sHsps interaction. Finally, secreted human sHsps seem to interact with receptor proteins, potentially as signal molecules transmitting the stress status from one cell to another. This review focuses on the mechanistic description of these different binding modes for human sHsps and how this might help to understand and modulate the function of sHsps in the context of disease. PMID:25915440

  9. 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

  10. 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

  11. Use of cyclotrons in medicine

    NASA Astrophysics Data System (ADS)

    Qaim, S. M.

    2004-10-01

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

  12. 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

  13. Costs of First-Line Doublet Chemotherapy and Lifetime Medical Care in Advanced Non–small-Cell Lung Cancer in the United States

    Microsoft Academic Search

    Kathleen Lang; Martin D. Marciniak; Douglas Faries; Michael Stokes; Don Buesching; Craig Earle; Joseph Treat; Steve Babineaux; Nathalie Morissette; David Thompson

    2009-01-01

    ObjectivesThe purpose of this study was to identify total lifetime medical-care costs and costs associated with first-line chemotherapy treatment among older patients with stage IIIB\\/IV non–small-cell lung cancer treated with commonly used two-drug chemotherapy (“doublet”) regimens in the United States.

  14. The cyclotron laboratory and the RFQ accelerator in Bern

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

  15. 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.

  16. Ion sources for cyclotron applications

    SciTech Connect

    Leung, K.N.; Bachman, D.A.; McDonald, D.S.; Young, A.T.

    1992-07-01

    The use of a multicusp plasma generator as an ion source has many advantages. The development of both positive and negative ion beams based on the multicusp source geometry is presented. It is shown that these sources can be operated at steady state or cw mode. As a result they are very suitable for cyclotron operations.

  17. 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.

  18. High performance computation on beam dynamics problems in high intensity compact cyclotrons

    NASA Astrophysics Data System (ADS)

    Yang, JianJun; Zhang, TianJue; Lin, YuZheng; Adelmann, Andreas; Wang, Feng; An, ShiZhong

    2011-12-01

    This paper presents the research progress in the beam dynamics problems for future high intensity compact cyclotrons by utilizing the state-of-the-art high performance computation technology. A "Start-to-Stop" model, which includes both the interaction of the internal particles of a single bunch and the mutual interaction of neighboring multiple bunches in the radial direction, is established for compact cyclotrons with multi-turn extraction. This model is then implemented in OPAL-CYCL, which is a 3D object-oriented parallel code for large scale particle simulations in cyclotrons. In addition, to meet the running requirement of parallel computation, we have constructed a small scale HPC cluster system and tested its performance. Finally, the high intensity beam dynamics problems in the 100 MeV compact cyclotron, which is being constructed at CIAE, are studied using this code and some conclusions are drawn.

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

    SciTech Connect

    Kim, Jong-Won [National Cancer Center, 809 Madu-dong, Goyang, Kyonggi 410-769 (Korea, Republic of); Yun, Chong-Chul; Youn, Min-Yong [National Center for Inter-University Research Facilities, Seoul National University, Sillim-dong, Gwanak, Seoul 151-742 (Korea, Republic of); Wang, Sonjong [Center for Fusion Engineering, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of)

    2009-03-10

    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.

  20. 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.

  1. 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.

  2. 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 into the non-linear regime. Relativistic effects on the current generated are discussed. Applications to steady

  3. 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

  4. Ion cyclotron modes in tokamaks

    NASA Astrophysics Data System (ADS)

    Waltz, R. E.; Dominguez, R. R.

    1981-08-01

    A linear theory of electrostatic ion cyclotron normal modes with moderate wavenumber, which can exist in a sheared magnetic field, is given. Such modes have been seen in a scattering experiment on the TFR tokamak. A novel mode with fluid electron behavior is found, and the Drummond and Rosenbluth current driven mode with kinetic electron behavior is recovered. Toroidal effects are considered. The kinetic modes offer the most natural explanation for the experimental frequency spectrum. However, numerical solutions of the dispersion relations predict that current drifts three to ten times larger than those in TFR are needed for instability.

  5. The Coaxial-Ring Cyclotron as a powerful multipurpose proton accelerator

    NASA Astrophysics Data System (ADS)

    Tumanian, A. R.; Guiragossian, Z. G.; Nikoghosian, V. Ts.; Tsakanov, V. M.

    1997-02-01

    The concept and general layout of a new high-power proton multistage isochronous cyclotron is presented. Key design features include the use of large-diameter cyclotron rings having low magnetic fields and the coaxial nesting of several cyclotron stages. The proposed Coaxial-Ring Cyclotrons (CRC) accelerator system has several advantages as compared to conventional cyclotrons. It has wide turn-to-turn separation of orbits, high energy gains per turn with small number of turns in each cyclotron stage, to produce high space-charge-limited beam current, simplified beam injection and extraction at low loss, an ability to inject and simultaneously accelerate multiple independent beams, and to extract different energy beams from the intermediate orbits of cyclotron stages. One or several Radio Frequency Quadrupole (RFQ) injectors are used to provide the necessary high brightness injection. Thus, a high-current, 1.5-GeV highly-efficient and cost-effective accelerator system is conceived, specifically to serve as the proton driver in several applications of the Accelerator Driven Transmutation Technologies (ADTT), and also to serve as a photon cancer therapy source, a materials processing source, as well as to act as a high-quality accelerator for the conduct of fundamental research in physics with intense beams of neutrons, neutrinos, muons and mesons. This paper describes the general layout of the nested five stages of cyclotrons, to produce 1.0-to-1.5-GeV, 1.0-to-20-mA average-current protons in single-beam injection, or higher currents by multiple-beam injection, fitting into the 70-m diameter main ring and the inner circular hall of the existing 6-GeV Yerevan Electron Synchrotron, and converting all related facilities.

  6. Collegiate-Based Emergency Medical Service: Impact on Alcohol-Related Emergency Department Transports at a Small Liberal Arts College

    ERIC Educational Resources Information Center

    Rosen, Joshua B.; Olson, Mark H.; Kelly, Marianne

    2012-01-01

    Objective: The authors examined the impact of a collegiate-based emergency medical service (CBEMS) on the frequency of emergency department (ED) transports. Participants: Students transported to the ED for acute alcohol intoxication during the Fall 2008 and the Fall 2009 semesters (N = 50). Methods: The frequency of students receiving…

  7. 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.

  8. K-130 Cyclotron vacuum system

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  10. Electron cyclotron emission from nonthermal tokamak plasmas

    SciTech Connect

    Harvey, R.W.; O'Brien, M.R.; Rozhdestvensky, V.V.; Luce, T.C.; McCoy, M.G.; Kerbel, G.D. (General Atomics, San Diego, California 92186-9784 (United States))

    1993-02-01

    Electron cyclotron emission can be a sensitive indicator of nonthermal electron distributions. A new, comprehensive ray-tracing and cyclotron emission code that is aimed at predicting and interpreting the cyclotron emission from tokamak plasmas is described. The radiation transfer equation is solved along Wentzel--Kramers--Brillouin (WKB) rays using a fully relativistic calculation of the emission and absorption from electron distributions that are gyrotropic and toroidally symmetric, but may be otherwise arbitrary functions of the constants of motion. Using a radial array of electron distributions obtained from a bounce-averaged Fokker--Planck code modeling dc electron field and electron cyclotron heating effects, the cyclotron emission spectra are obtained. A pronounced strong nonthermal cyclotron emission feature that occurs at frequencies relativistically downshifted to second harmonic cyclotron frequencies outside the tokamak is calculated, in agreement with experimental results from the DIII-D [J. L. Luxon and L. G. Davies, Fusion Technol. [bold 8], 441 (1985)] and FT-1 [D. G. Bulyginsky [ital et] [ital al]., in [ital Proceedings] [ital of] [ital the] 15[ital th] [ital European] [ital Conference] [ital on] [ital Controlled] [ital Fusion] [ital and] [ital Plasma] [ital Heating], Dubrovnik, 1988 (European Physical Society, Petit-Lancy, 1988), Vol. 12B, Part II, p. 823] tokamaks. The calculations indicate the presence of a strong loss mechanism that operates on electrons in the 100--150 keV energy range.

  11. 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.

  12. 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.

  13. Department of Engineering Spring 2011 B. Braun Medical: Non-Interchangeable Small-Bore Connectors for Liquids and

    E-print Network

    Demirel, Melik C.

    -Bore Connectors for Liquids and Gases in Healthcare Applications Sarah Knupp, Taylor Stine, Taylor Jedrek, Kayla. The deliverables required included four concepts of non-interchangeable connectors, and a report proving's objective was to develop four concepts of non-interchangeable small-bore connector pairs. Concept generation

  14. Method and apparatuses for ion cyclotron spectrometry

    DOEpatents

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

    2012-03-06

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

  15. 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

  16. Backward-wave cyclotron maser oscillator experiment

    SciTech Connect

    Jerby, E.; Shahadi, A.; Agmon, E.; Golombek, H.; Grinberg, V.; Bensal, M. [Tel Aviv Univ., Ramat Aviv (Israel). Faculty of Engineering; Bekefi, G. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1994-12-31

    A backward-wave cyclotron maser oscillator experiment conducted at Tel Aviv University is reported in this paper. The oscillator operates in the microwave regime (9.4 GHz) with a low-energy electron beam pulse (8 keV, 0.2 A, 1 ms). A frequency chirping effect observed by an heterodyne technique reveals the cyclotron resonance with a backward wave harmonic of the periodic waveguide.

  17. Recent development and progress of IBA cyclotrons

    Microsoft Academic Search

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

    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

  18. The experience of the clinical photographer, when working in both large and small medical illustration departments in the UK.

    PubMed

    Grice, Katherine; Treen, Nicola

    2010-06-16

    Working in a large department with an assorted staff of photographers, managers, graphic designers and administrators numbering thirty-plus is a radically different experience from working in a department that numbers two or three. The authors of this paper have both worked in large and small departments and were quite surprised by the similarities and differences between these two working experiences. Their impressions are shared here. PMID:20557162

  19. Electrostatic ion cyclotron, beam-plasma, and lower hybrid waves excited by an electron beam

    SciTech Connect

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

    1985-06-01

    It is pointed out that electrostatic ion cyclotron (EIC) waves have been extensively investigated in connection with both space and laboratory plasmas. The present investigation has the objective to study the excitation of low-frequency waves in a multiion plasma by electron beams. The frequencies considered range from below the lowest gyrofrequency of the heaviest ion to about the lower hybrid frequency. It is shown that electron-beam instabilities can produce peaks in the growth rate below the cyclotron frequency of each ion species if nonzero perpendicular wave number effects are included in the ion dynamics. The dispersion relations for neutralized ion Bernstein (NIB) and pure ion Bernstein (PIB) waves are considered along with an instability analysis for a cold plasma and warm electron beam, the electron beam-plasma mode, banded ion cyclotron (EIC) waves with small perpendicular wavelengths, and the growth lengths of the waves. 39 references.

  20. Electrostatic ion cyclotron, beam-plasma, and lower hybrid waves excited by an electron beam

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    It is pointed out that electrostatic ion cyclotron (EIC) waves have been extensively investigated in connection with both space and laboratory plasmas. The present investigation has the objective to study the excitation of low-frequency waves in a multiion plasma by electron beams. The frequencies considered range from below the lowest gyrofrequency of the heaviest ion to about the lower hybrid frequency. It is shown that electron-beam instabilities can produce peaks in the growth rate below the cyclotron frequency of each ion species if nonzero perpendicular wave number effects are included in the ion dynamics. The dispersion relations for neutralized ion Bernstein (NIB) and pure ion Bernstein (PIB) waves are considered along with an instability analysis for a cold plasma and warm electron beam, the electron beam-plasma mode, banded ion cyclotron (EIC) waves with small perpendicular wavelengths, and the growth lengths of the waves.

  1. Space-charge-Cerenkov and cyclotron-Cerenkov instabilities in an electron-beam dielectric system

    SciTech Connect

    Case, W.B.; Kaplan, R.D.; Golub, J.E.; Walsh, J.E.

    1984-04-01

    A relativistic electron beam propagating along a constant magnetic field has four normal modes: the slow and fast space charge and the slow and fast cyclotron modes. When propagating through a dielectric where the beam velocity is greater than the velocity of light in the dielectric, the slow modes may become unstable. We call these the space-charge-Cerenkov and cyclotron-Cerenkov instabilities. In this paper we use the cold fluid model in the small signal limit to obtain a general dispersion relation for propagation at an arbitrary direction with respect to the magnetic guide field. This describes both of the above instabilities as special cases. This result is then generalized to include the effects of a thermal spread. Implications for possible application for generation or amplification of microwaves, where the beam passes near the dielectric, are also considered. We conclude that the cyclotron-Cerenkov instability is a strong candidate for the short wavelength microwave regime.

  2. Oak Ridge Isotope Production Cyclotron Facility and Target Handling

    SciTech Connect

    Bradley, Eric Craig [ORNL; Varma, Venugopal Koikal [ORNL; Egle, Brian [ORNL; Binder, Jeffrey L [ORNL; Mirzadeh, Saed [ORNL; Tatum, B Alan [ORNL; Burgess, Thomas W [ORNL; Devore, Joe [Oak Ridge National Laboratory (ORNL); Rennich, Mark [Oak Ridge National Laboratory (ORNL); Saltmarsh, Michael John [ORNL; Caldwell, Benjamin Cale [Oak Ridge National Laboratory (ORNL)

    2011-01-01

    Abstract The Nuclear Science Advisory Committee issued in August 2009 an Isotopes Subcommittee report that recommended the construction and operation of a variable-energy, high-current, multiparticle accelerator for producing medical radioisotopes. To meet the needs identified in the report, Oak Ridge National Laboratory is developing a technical concept for a commercial 70 MeV dual-port-extraction, multiparticle cyclotron to be located at the Holifield Radioactive Ion Beam Facility. The conceptual design of the isotope production facility as envisioned would provide two types of targets for use with this new cyclotron. One is a high-power target cooled by water circulating on both sides, and the other is a commercial target cooled only on one side. The isotope facility concept includes an isotope target vault for target irradiation and a shielded transfer station for radioactive target handling. The targets are irradiated in the isotope target vault. The irradiated targets are removed from the target vault and packaged in an adjoining shielded transfer station before being sent out for postprocessing. This paper describes the conceptual design of the target-handling capabilities required for dealing with these radioactive targets and for minimizing the contamination potential during operations.

  3. 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.

  4. Recycling and recommissioning a used biomedical cyclotron

    NASA Astrophysics Data System (ADS)

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

    2001-07-01

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

  5. Implementation of the chronic care model in small medical practices improves cardiovascular risk but not glycemic control.

    PubMed

    Frei, Anja; Senn, Oliver; Chmiel, Corinne; Reissner, Josiane; Held, Ulrike; Rosemann, Thomas

    2014-04-01

    OBJECTIVE To test whether the implementation of elements of the Chronic Care Model (CCM) via a specially trained practice nurse leads to an improved cardiovascular risk profile among type 2 diabetes patients. RESEARCH DESIGN AND METHODS This cluster randomized controlled trial with primary care physicians as the unit of randomization was conducted in the German part of Switzerland. Three hundred twenty-six type 2 diabetes patients (age >18 years; at least one glycosylated hemoglobin [HbA1c] level of ?7.0% [53 mmol/mol] in the preceding year) from 30 primary care practices participated. The intervention included implementation of CCM elements and involvement of practice nurses in the care of type 2 diabetes patients. Primary outcome was HbA1c levels. The secondary outcomes were blood pressure (BP), LDL cholesterol, accordance with CCM (assessed by Patient Assessment of Chronic Illness Care [PACIC] questionnaire), and quality of life (assessed by the 36-item short-form health survey [SF-36]). RESULTS After 1 year, HbA1c levels decreased significantly in both groups with no significant difference between groups (-0.05% [-0.60 mmol/mol]; P = 0.708). Among intervention group patients, systolic BP (-3.63; P = 0.050), diastolic BP (-4.01; P < 0.001), LDL cholesterol (-0.21; P = 0.033), and PACIC subscores (P < 0.001 to 0.048) significantly improved compared with control group patients. No differences between groups were shown in the SF-36 subscales. CONCLUSIONS A chronic care approach according to the CCM and involving practice nurses in diabetes care improved the cardiovascular risk profile and is experienced by patients as a better structured care. Our study showed that care according to the CCM can be implemented even in small primary care practices, which still represent the usual structure in most European health care systems. PMID:24513589

  6. Ototoxic Medications (Medication Effects)

    MedlinePLUS

    Ototoxic Medications (Medication Effects) By Barbara Cone, Patricia Dorn, Dawn Konrad-Martin, Jennifer Lister, Candice Ortiz, and ... in our Audiology Information Series [PDF]. What Is Ototoxicity? Certain medications can damage the ear, resulting in ...

  7. 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 ...

  8. 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.

  9. 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

  10. 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.

  11. Currents driven by electron cyclotron waves

    SciTech Connect

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

    1981-07-01

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

  12. Cyclotron braid group structure for composite fermions.

    PubMed

    Jacak, J; Jó?wiak, I; Jacak, L; Wieczorek, K

    2010-09-01

    Although they describe properties of 2D Hall systems in the fractional quantum regime well, composite fermions suffer from the unexplained character of the localized magnetic field flux-tubes attached to each particle in order to reproduce the Laughlin correlations via Aharonov-Bohm phase shifts. The identification of the cyclotron trajectories of 2D charged particles as accessible classical trajectories within the braid group approach at the magnetic field presence, allows, however, for the avoidance of the construction with fluxes. We introduce cyclotron braid subgroups for charged 2D systems at the fractional Landau-level filling associated in a more natural way with composite fermions without invoking field flux-tubes. The Aharonov-Bohm phase shifts caused by fluxes are replaced with the phase gain due to multi-loop cyclotron trajectories unavoidably occurring at the fractional filling of 1/p (p is an odd integer). Another approach to composite particles, using so-called vortices, is also discussed from the point of view of the cyclotron braid group description (for both odd and even p integers). PMID:21403293

  13. 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.

  14. On Resonant Heating Below the Cyclotron Frequency

    SciTech Connect

    Liu Chen; Zhihong Lin; White, R.

    2001-02-02

    Resonant heating of particles by an electrostatic wave propagating perpendicular to a confining uniform magnetic field is examined. It is shown that, with a sufficiently large wave amplitude, significant perpendicular stochastic heating can be obtained with wave frequency at a fraction of the cyclotron frequency.

  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. Ion Cyclotron Waves in the VASIMR

    Microsoft Academic Search

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

    2008-01-01

    The Variable Specific Impulse Magnetoplasma Rocket is an electric propulsion system under development at Ad Astra Rocket Company that utilizes several processes of ion acceleration and heating that occur in the Birkeland currents of an auroral arc system. Among these processes are parallel electric field acceleration, lower hybrid resonance heating, and ion cyclotron resonance heating. The VASIMR is capable of

  17. Relativistic cyclotron for the University of Milan

    Microsoft Academic Search

    A. Luccio; G. Pavanati; F. Resmini; C. Succi; G. Tagliaferri

    1962-01-01

    A fixed frequency, fixed energy Thomas cyclotron is presently under ; construction at the University of Milan. With a pole diameter of 186 cm, the ; planned energy is 45 Mev for protons; magnet winding and d.c. power supply are ; however rated to stand at ieast a 20% increase in energy. Model studies of the ; magnet field and

  18. 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.

  19. Live small-animal X-ray lung velocimetry and lung micro-tomography at the Australian Synchrotron Imaging and Medical Beamline.

    PubMed

    Murrie, Rhiannon P; Morgan, Kaye S; Maksimenko, Anton; Fouras, Andreas; Paganin, David M; Hall, Chris; Siu, Karen K W; Parsons, David W; Donnelley, Martin

    2015-07-01

    The high flux and coherence produced at long synchrotron beamlines makes them well suited to performing phase-contrast X-ray imaging of the airways and lungs of live small animals. Here, findings of the first live-animal imaging on the Imaging and Medical Beamline (IMBL) at the Australian Synchrotron are reported, demonstrating the feasibility of performing dynamic lung motion measurement and high-resolution micro-tomography. Live anaesthetized mice were imaged using 30?keV monochromatic X-rays at a range of sample-to-detector propagation distances. A frame rate of 100?frames?s(-1) allowed lung motion to be determined using X-ray velocimetry. A separate group of humanely killed mice and rats were imaged by computed tomography at high resolution. Images were reconstructed and rendered to demonstrate the capacity for detailed, user-directed display of relevant respiratory anatomy. The ability to perform X-ray velocimetry on live mice at the IMBL was successfully demonstrated. High-quality renderings of the head and lungs visualized both large structures and fine details of the nasal and respiratory anatomy. The effect of sample-to-detector propagation distance on contrast and resolution was also investigated, demonstrating that soft tissue contrast increases, and resolution decreases, with increasing propagation distance. This new capability to perform live-animal imaging and high-resolution micro-tomography at the IMBL enhances the capability for investigation of respiratory diseases and the acceleration of treatment development in Australia. PMID:26134810

  20. Production of flickering aurora and field-aligned electron flux by electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Temerin, M.; Mcfadden, J.; Boehm, M.; Carlson, C. W.; Lotko, W.

    1986-01-01

    Recent observations have suggested that flickering aurora is produced by a modulation of the field-aligned component of the electron flux within an auroral arc. It is proposed that a portion of the field-aligned electrons are of ionospheric origin and that these electrons are accelerated and their flux modulated by electromagnetic ion cyclotron waves that occur below the main acceleration region on auroral arc field lines. A model of the electromagnetic ion cyclotron wave shows that the parallel phase velocity of the wave increase as the wave propagates toward the ionosphere. A test particle calculation shows that ionospheric electrons trapped or reflected by the wave are accelerated to energies of several keV and that their flux is modulated at the wave frequency. The relative amplitudes of the model wave electric fields are consistent with the observations of small-scale low-frequency ionospheric and magnetospheric electric fields near auroral arcs of approximately 10 mV/m and 100 mV/m, respectively. The large-amplitude ion cyclotron waves also produce a ponderomotive force and a self-consistent ambipolar electric field. Energy considerations show that the downward energy flux in the electromagnetic ion cyclotron wave can be several percent of the total downward auroral electron energy flux.

  1. Magnetic Alfvén-cyclotron fluctuations of anisotropic nonthermal plasmas

    NASA Astrophysics Data System (ADS)

    Navarro, Roberto E.; Muñoz, Víctor; Araneda, Jaime; Viñas, Adolfo F.-; Moya, Pablo S.; Valdivia, Juan A.

    2015-04-01

    Remote and in situ observations in the solar wind show that ion and electron velocity distributions persistently present deviations from thermal equilibrium. Ion anisotropies seem to be constrained by instability thresholds which are in agreement with linear kinetic theory. For plasma states below these instability thresholds, the quasi-stable solar wind plasma sustains a small but detectable level of magnetic fluctuation power. These fluctuations may be related to spontaneous electromagnetic fluctuations arising from the discreteness and thermal motion of charged particles. Here we study magnetic Alfvén-cyclotron fluctuations propagating along a background magnetic field in a plasma composed of thermal and suprathermal protons and electrons via the fluctuation-dissipation theorem. The total fluctuating magnetic power is estimated in a proton temperature anisotropy-beta diagram for three different families of proton distribution functions, which can be compared to a number of recent measurements in the solar wind.

  2. 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.

  3. 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.

  4. 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.

  5. ENSEMBLE SIMULATIONS OF PROTON HEATING IN THE SOLAR WIND VIA TURBULENCE AND ION CYCLOTRON RESONANCE

    SciTech Connect

    Cranmer, Steven R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2014-07-01

    Protons in the solar corona and heliosphere exhibit anisotropic velocity distributions, violation of magnetic moment conservation, and a general lack of thermal equilibrium with the other particle species. There is no agreement about the identity of the physical processes that energize non-Maxwellian protons in the solar wind, but a traditional favorite has been the dissipation of ion cyclotron resonant Alfvén waves. This paper presents kinetic models of how ion cyclotron waves heat protons on their journey from the corona to interplanetary space. It also derives a wide range of new solutions for the relevant dispersion relations, marginal stability boundaries, and nonresonant velocity-space diffusion rates. A phenomenological model containing both cyclotron damping and turbulent cascade is constructed to explain the suppression of proton heating at low alpha-proton differential flow speeds. These effects are implemented in a large-scale model of proton thermal evolution from the corona to 1 AU. A Monte Carlo ensemble of realistic wind speeds, densities, magnetic field strengths, and heating rates produces a filled region of parameter space (in a plane described by the parallel plasma beta and the proton temperature anisotropy ratio) similar to what is measured. The high-beta edges of this filled region are governed by plasma instabilities and strong heating rates. The low-beta edges correspond to weaker proton heating and a range of relative contributions from cyclotron resonance. On balance, the models are consistent with other studies that find only a small fraction of the turbulent power spectrum needs to consist of ion cyclotron waves.

  6. A Kinetic Model of Solar Wind Generation by Oblique Ion-cyclotron Waves

    NASA Astrophysics Data System (ADS)

    Isenberg, Philip A.; Vasquez, Bernard J.

    2011-04-01

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

  7. 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).

  8. Orbit correction in an orbit separated cyclotron

    NASA Astrophysics Data System (ADS)

    Plostinar, C.; Rees, G. H.

    2014-04-01

    The orbit separated proton cyclotron (OSC) described in [1] differs in concept from that of a separated orbit cyclotron (SOC) [2]. Synchronous acceleration in an OSC is based on harmonic number jumps and orbit length adjustments via reverse bending. Four-turn acceleration in the OSC enables it to have four times fewer cryogenic-cavity systems than in a superconducting linac of the same high beam power and energy range. Initial OSC studies identified a progressive distortion of the spiral beam orbits by the off-axis, transverse deflecting fields in its accelerating cavities. Compensation of the effects of these fields involves the repeated use of a cavity field map, in a 3-D linac tracking code, to determine the modified arc bends required for the OSC ring. Subsequent tracking studies confirm the compensation scheme and show low emittance growth in acceleration.

  9. Microhardness evaluation of cyclotron foil windows

    NASA Astrophysics Data System (ADS)

    Finn, R.; Shives, T.; Brady, C.; Plascjak, P.; Meyer, W.; Sheh, Y.

    1989-04-01

    The production of radiopharmaceuticals for application to positron emission tomography necessitates radionuclides of finite specific activity and chemical purity. Reliable, routine production of the short-lived, biologically useful radionuclides has required careful selection of target system materials. The degenerative effects of high beam currents and use of refrigerated cooling units on metallic cyclotron target windows are of particular interest. Repeated subjection of the metallic windows and target bodies to energetic charged particles induces crystalline lattice imperfections and strain hardening. The reduction in ductility of the foil window appears to correlate with an increase in hardness as evaluated using the Knoop microhardness technique and optical microscopic examination on both aluminum and Havar irradiated cyclotron windows. A summary of our results on the above effects will be presented.

  10. Dispersion Solver with Relativistic Cyclotron Resonance

    NASA Astrophysics Data System (ADS)

    Nakamura, T. K.

    2002-12-01

    A method to calculate linear dispersion relation of electromagnetic waves in a relativistic plasma is proposed. Exact analytic calculation with relativistic cyclotron resonances is extremely difficult because the cyclotron frequency depends on both parallel and perpendicular (to magnetic field) velocities due to the relativistic effect. To avoid this difficulty, the method presented here makes use of algebraic approximation to the velocity distribution function. Algebraic approximation enables analytical velocity integration with the residue theorem; results are highly accurate when applied to non-relativistic calculation (see references). The same tactics can be applied for relativistic plasmas, however, there comes a problem of branch cut and multiple Riemann surfaces. This problem must be overcome by ad hoc technique depending on each specific wave mode. Calculation for a parallel propagating electromagnetic wave in a relativistic plasma will be presented as an example. References: Lofgren et al., Phys. Plasmas, vol 4, 1124 (1997). Nakamura, T. K., and M. Hoshino, Phys. Plasmas, vol 5, 3547 (1998).

  11. 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.

  12. 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.

  13. Current driven electromagnetic ion cyclotron instability

    Microsoft Academic Search

    D. W. Forslund; J. M. Kindel; M. A. Stroscio

    1979-01-01

    A detailed investigation of the electron-current-driven electro-magnetic ion cyclotron instability is presented which extends the original work on the subject by Stix (1962). An infinite uniform collisionless Maxwellian plasma embedded in a constant dc magnetic field is assumed. Analytical derivation of the critical drift velocity spans the range of ion-beta from about 0.001 to 0.1. An important result is that

  14. 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

  15. 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.

  16. 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.

  17. Transparency of Magnetized Plasma at Cyclotron Frequency

    SciTech Connect

    G. Shvets; J.S. Wurtele

    2002-03-14

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

  18. Cyclotron Requirements for Multi-disciplinary Programs

    SciTech Connect

    Armbruster, John M. [IBA Molecular, 3601 Morgantown Industrial Park, Morgantown, WV 26501 (United States)

    2009-03-10

    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.

  19. Improving cancer treatment with cyclotron produced radionuclides

    SciTech Connect

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

    1992-08-04

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

  20. A phantom experiment for the evaluation of whole body exposure during BNCT using cyclotron-based epithermal neutron source (C-BENS)

    Microsoft Academic Search

    T. Tsukamoto; H. Tanaka; H. Yoshinaga; T. Mitsumoto; A. Maruhashi; K. Ono; Y. Sakurai

    2011-01-01

    At Kyoto University Research Reactor Institute (KURRI), cyclotron-based epithermal neutron source was installed in December 2008, and the supplementary construction works have been performed. As of December 2010, the various irradiation characteristics important for BNCT were mostly evaluated. The whole body exposure during BNCT medical irradiation is one of the important characteristics.In this article, measurements of absorbed dose for thermal

  1. Current driven electrostatic and electromagnetic ion cyclotron instabilities

    NASA Technical Reports Server (NTRS)

    Forslund, D. W.; Kennel, C. F.; Kindel, J. M.

    1971-01-01

    Growth rates and parameter dependences are calculated for the current driven instabilities of electrostatic (with finite-beta corrections) and electromagnetic ion cyclotron waves. For 0.25 (T sub e)/(T sub i) 2.5, ion cyclotron waves have large growth rates, while ion acoustic waves are still stable. In fusion devices, where electrostatic waves may be stable, electromagnetic ion cyclotron waves are unstable for beta sub i 0.001.

  2. Second-cyclotron-harmonic emission measurements on ISX-B

    SciTech Connect

    Kulchar, A.G.; Wilgen, J.B.; England, A.C.; Eldridge, O.C.; Loring, C.M.; Bekefi, G.; Hackett, K.E.

    1982-04-01

    Second harmonic cyclotron radiation was used to measure the electron temperature during electron cyclotron heating (ECH) on the Impurity Study Experiment (ISX-B) tokamak. The 58-GHz and 70-GHz microwave superheterodyne receivers used for the measurements are described in detail. The limitations of the use of cyclotron radiation for a temperature measurement are quantified in terms of both the density and the temperature. A comparison is made between the results from the microwave diagnostics and those from the laser Thomson scattering to demonstrate that the cyclotron emission is thermal. A brief discussion of sensitivity to runaways and to other nonthermal populations is given.

  3. Fundamental ion cyclotron resonance heating of JET deuterium plasmas

    SciTech Connect

    Krasilnikov, A. V. [Troitsk Institute of Nuclear Physics (TRINITI), Russia; Van Eester, D. [Laboratory for Plasma Physics-ERM/KMS (LPP-ERM/KMS), Brussels, Belgium; Lerche, E. [Laboratory for Plasma Physics-ERM/KMS (LPP-ERM/KMS), Brussels, Belgium; Ongena, J. [Laboratory for Plasma Physics-ERM/KMS (LPP-ERM/KMS), Brussels, Belgium; Amosov, V. N. [Troitsk Institute of Nuclear Physics (TRINITI), Russia; Biewer, Theodore M [ORNL; Bonheure, G. [Laboratory for Plasma Physics-ERM/KMS (LPP-ERM/KMS), Brussels, Belgium; Crombe, K. [Ghent University, Belgium; Ericsson, G. [Uppsala University, Uppsala, Sweden; Esposito, Basilio [ENEA, Frascati; Giacomelli, L. [Uppsala University, Uppsala, Sweden; Hellesen, C. [Uppsala University, Uppsala, Sweden; Hjalmarsson, A. [Uppsala University, Uppsala, Sweden; Jachmich, S. [EURATOM / UKAEA, UK; Kallne, J. [Uppsala University, Uppsala, Sweden; Kaschuck, Yu A [Troitsk Institute of Nuclear Physics (TRINITI), Russia; Kiptily, V. [EURATOM / UKAEA, UK; Leggate, H. [EURATOM / UKAEA, UK; Mailloux, J. [EURATOM / UKAEA, UK; Marocco, D. [ENEA, Frascati; Mayoral, M.-L. [EURATOM / UKAEA, UK; Popovichev, S. [EURATOM / UKAEA, UK; Riva, M. [ENEA, Frascati; Santala, M. [EURATOM / UKAEA, UK; Stamp, M. F. [EURATOM / UKAEA, UK; Vdovin, V. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Walden, A. [EURATOM / UKAEA, UK

    2009-03-01

    Radio frequency heating of majority ions is of prime importance for understanding the basic role of auxiliary heating in the activated D T phase of ITER. Majority deuterium ion cyclotron resonance heating (ICRH) experiments at the fundamental cyclotron frequency were performed in JET. In spite of the poor antenna coupling at 25 MHz, this heating scheme proved promising when adopted in combination with D neutral beam injection (NBI). The effect of fundamental ICRH of a D population was clearly demonstrated in these experiments: by adding ~25% of heating power the fusion power was increased up to 30 50%, depending on the type of NBI adopted. At this power level, the ion and electron temperatures increased from Ti ~ 4.0 keV and Te ~ 4.5 keV (NBI-only phase) to Ti ~ 5.5 keV and Te ~ 5.2 keV (ICRH + NBI phase), respectively. The increase in the neutron yield was stronger when 80 keV rather than 130 keV deuterons were injected in the plasma. It is shown that the neutron rate, the diamagnetic energy and the electron as well as the ion temperature scale roughly linearly with the applied RF power. A synergistic effect of the combined use of ICRF and NBI heating was observed: (i) the number of neutron counts measured by the neutron camera during the combined ICRF + NBI phases of the discharges exceeded the sum of the individual counts of the NBI-only and ICRF-only phases; (ii) a substantial increase in the number of slowing-down beam ions was detected by the time of flight neutron spectrometer when ICRF power was switched on; (iii) a small D subpopulation with energies slightly above the NBI launch energy was detected by the neutral particle analyzer and -ray spectroscopy.

  4. Fundamental ion cyclotron resonance heating of JET deuterium plasmas

    NASA Astrophysics Data System (ADS)

    Krasilnikov, A. V.; Van Eester, D.; Lerche, E.; Ongena, J.; Amosov, V. N.; Biewer, T.; Bonheure, G.; Crombe, K.; Ericsson, G.; Esposito, B.; Giacomelli, L.; Hellesen, C.; Hjalmarsson, A.; Jachmich, S.; Kallne, J.; Kaschuck, Yu A.; Kiptily, V.; Leggate, H.; Mailloux, J.; Marocco, D.; Mayoral, M.-L.; Popovichev, S.; Riva, M.; Santala, M.; Stamp, M.; Vdovin, V.; Walden, A.; JET EFDA Task Force Heating; JET EFDA contributors

    2009-04-01

    Radio frequency heating of majority ions is of prime importance for understanding the basic role of auxiliary heating in the activated D-T phase of ITER. Majority deuterium ion cyclotron resonance heating (ICRH) experiments at the fundamental cyclotron frequency were performed in JET. In spite of the poor antenna coupling at 25 MHz, this heating scheme proved promising when adopted in combination with D neutral beam injection (NBI). The effect of fundamental ICRH of a D population was clearly demonstrated in these experiments: by adding ~25% of heating power the fusion power was increased up to 30-50%, depending on the type of NBI adopted. At this power level, the ion and electron temperatures increased from Ti ~ 4.0 keV and Te ~ 4.5 keV (NBI-only phase) to Ti ~ 5.5 keV and Te ~ 5.2 keV (ICRH + NBI phase), respectively. The increase in the neutron yield was stronger when 80 keV rather than 130 keV deuterons were injected in the plasma. It is shown that the neutron rate, the diamagnetic energy and the electron as well as the ion temperature scale roughly linearly with the applied RF power. A synergistic effect of the combined use of ICRF and NBI heating was observed: (i) the number of neutron counts measured by the neutron camera during the combined ICRF + NBI phases of the discharges exceeded the sum of the individual counts of the NBI-only and ICRF-only phases; (ii) a substantial increase in the number of slowing-down beam ions was detected by the time of flight neutron spectrometer when ICRF power was switched on; (iii) a small D subpopulation with energies slightly above the NBI launch energy was detected by the neutral particle analyzer and ?-ray spectroscopy.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

    Hoehr, C.; Uittenbosch, T.; Verzilov, V.; English, W.; Buckley, K.; Gray, D.; Kellog, S.; Cameron, D.; Schaffer, P.

    2012-12-01

    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 ?A. Herein are reported preliminary beam-profile measurement results.

  7. 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.

  8. 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.

  9. Cyclotron Mode Frequency Shifts in Multi-Species Ion Plasmas

    NASA Astrophysics Data System (ADS)

    Affolter, Matthew

    2014-10-01

    Plasmas exhibit a variety of cyclotron modes, which are used in a broad range of devices to manipulate and diagnose charged particles. Here we discuss cyclotron modes in trapped plasmas with a single sign of charge. Collective effects and electric fields shift these cyclotron mode frequencies away from the ``bare'' cyclotron frequencies ?s ? qB /ms c for each species s. These electric fields may arise from applied trap potentials, from space charge including collective effects, and from image charge in the trap walls. We will describe a new laser-thermal cyclotron spectroscopy technique, applied to well-diagnosed pure ion plasmas. This technique enables detailed observations of cos (m?) surface cyclotron modes with m = 0 , 1, and 2 in near rigid-rotor multi-species ion plasmas. For each species s, we observe cyclotron mode frequency shifts which are dependent on the plasma density through the E × B rotation frequency, and on the charge concentration of species s, in close agreement with recent theory. This includes the novel m = 0 radial ``breathing'' mode, which generates no external electric field except at the plasma ends. These cyclotron frequencies can be used to determine the plasma E × B rotation frequency and the species charge concentrations, in close agreement with our laser diagnostics. Here, this plasma characterization permits a determination of the ``bare'' cyclotron frequencies to an accuracy of 2 parts in 104. These new results give a physical basis for the ``space charge'' and ``amplitude'' calibration equations of cyclotron mass spectroscopy, widely used in molecular chemistry and biology. Also, at high temperatures there is preliminary evidence that radially-standing electrostatic Bernstein waves couple to the surface cyclotron modes, producing new resonant frequencies. Supported by NSF/DOE Partnership grants PHY-0903877 and DE-SC0002451.

  10. Ion cyclotron resonance heating and the Alfven-ion cyclotron instability

    Microsoft Academic Search

    T. Tajima; J. M. Dawson

    1980-01-01

    A simulation study of physical processes involved in ion cyclotron resonance heating and associated radio frequency plugging of a mirror confined plasma was carried out utilizing 1-2\\/2 dimensional magnetostatic particle code. Three heating regimes are discerned: weak, moderate and strong, characterized primarily by the pump wave amplitude. The pump waves induced other modes to various degrees, particularly so in the

  11. A Scanning Frequency Mode for Ion Cyclotron Mobility Spectrometry

    E-print Network

    Clemmer, David E.

    A Scanning Frequency Mode for Ion Cyclotron Mobility Spectrometry Rebecca S. Glaskin, Stephen J A new operational mode for an ion cyclotron mobility spectrometry instrument is explored as a possible-based separation by varying the ion cycle number has substantial analytical utility. Ion mobility spectrometry (IMS

  12. 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.

  13. Cyclotron resonance interaction of microwaves with energetic electrons

    Microsoft Academic Search

    J. L. Hirshfield; I. B. Bernstein; J. M. Wachtel

    1965-01-01

    Quantum mechanical and classical descriptions of microwave interaction with energetic electrons near cyclotron resonance which underlie the gain mechanism in the electron cyclotron maser are reviewed. Experimental studies designed to test the theory are discussed. A perturbation calculation is given which includes systematically the effects of RF electric and magnetic forces and finite transit time for electrons in the TE011cavity

  14. US Particle Accelerator School Cyclotrons: Old but Still New

    E-print Network

    Dai, Pengcheng

    US Particle Accelerator School Cyclotrons: Old but Still New The history of accelerators is a history of inventions William A. Barletta Director, US Particle Accelerator School Dept. of Physics, MIT Economics Faculty, University of Ljubljana #12;US Particle Accelerator School ~ 650 cyclotrons operating

  15. 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 auroral region, nearby a source region of Saturn kilometric radiation. Using the Cassini Radio and Plasma. Gurnett, F. Crary, and A. J. Coates (2011), Ion cyclotron harmonics in the Saturn downward current auroral

  16. Fundamental ion cyclotron resonance heating of JET deuterium plasmas

    Microsoft Academic Search

    A. V. Krasilnikov; D. Van Eester; E. Lerche; J. Ongena; V. N. Amosov; Theodore M Biewer; G. Bonheure; K. Crombe; G. Ericsson; Basilio Esposito; L. Giacomelli; C. Hellesen; A. Hjalmarsson; S. Jachmich; J. Kallne; Yu A. Kaschuck; V. Kiptily; H. Leggate; J. Mailloux; D. Marocco; M.-L. Mayoral; S. Popovichev; M. Riva; M. Santala; M. F. Stamp; V. Vdovin; A. Walden; JET EFDA contributors

    2009-01-01

    Radio frequency heating of majority ions is of prime importance for understanding the basic role of auxiliary heating in the activated D-T phase of ITER. Majority deuterium ion cyclotron resonance heating (ICRH) experiments at the fundamental cyclotron frequency were performed in JET. In spite of the poor antenna coupling at 25 MHz, this heating scheme proved promising when adopted in

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

    E-print Network

    California at San Diego, University of

    ], and has been observed in precision cyclotron mass spectrometry experiments [2, 3]. Previous experiments [4 the majority and minority species. EXPERIMENT The cyclotron modes are observed in a multispecies ion plasma-Malmberg trap is used to confine the plasma in a field of B = 2.96 Tesla. The plasma is maintained in a near

  18. 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.

  19. Medication Guide

    MedlinePLUS

    ... before starting any new medication. First-Line Medications: Nicotine Replacement Therapy (NRT) These medications are called "first- ... they might try a "second-line" medication instead. Nicotine replacement therapy (NRT) helps smokers quit by reducing ...

  20. Concept and utilization of a regional cyclotron center

    NASA Astrophysics Data System (ADS)

    Emran, Ali M.

    1993-06-01

    Cyclotrons have been proven to be valuable tools associated with development and applications of radioisotopes, radiochemicals and radiopharmaceuticals. Utilization of cyclotrons in biomedical research has increased to cover applications with SPECT and PET as major imaging modalities. The extensive cost of establishing a cyclotron facility has prompted development of more economically feasible sources of radioisotopes such as radioisotope generators. This idea presents the disadvantages of less versatility and production shortage. Therefore, the concept of a regional cyclotron center is being introduced for production of radiotracers to be utilized by users in the area. The Cyclotron Facility at the University of Texas Health Sciences Center at Houston (UTHSC-H) is being developed as a regional center where numerous radioisotopes and radiotracers have been developed and applied to various fields.

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

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  2. 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.

  3. Loss cone-driven cyclotron maser instability

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  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. Fundamental and harmonic electron cyclotron maser emission

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.

    1985-01-01

    The plasma conditions and features of the energetic electron distribution in electron cyclotron maser emission for which growth in a particular mode is favored when the ratio of the plasma frequency omega(p) to the electron cyclotron frequency Omega(e) is greater than about 0.3 are determined. It is shown that growth at the fundamental is suppressed as omega(p)/Omega(e) increases and emission at harmonics of Omega(e) dominates. Growth at harmonics of Omega(e) is not restricted to the O and X modes, but can also occur for the Z mode. Whether or not growth in a particular mode dominates depends both on omega(p)/Omega(e) and on the form of the distribution. If the density of the energetic electrons is sufficiently large, the dispersion relations of the O and X modes are modified so that the group velocities of the growing O and X mode waves can be comparable to that of the growing Z mode waves.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. Ionospheric modification at twice the electron cyclotron frequency.

    PubMed

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

    2005-04-01

    In 2004, a new transmission band was added to the HAARP high-frequency ionospheric modification facility that encompasses the second electron cyclotron harmonic at altitudes between approximately 220 and 330 km. Initial observations indicate that greatly enhanced airglow occurs whenever the transmission frequency approximately matches the second electron cyclotron harmonic at the height of the upper hybrid resonance. This is the reverse of what happens at higher electron cyclotron harmonics. The measured optical emissions confirm the presence of accelerated electrons in the plasma. PMID:15903924

  11. Beam cyclotron instability in a dusty plasma

    NASA Astrophysics Data System (ADS)

    Rosenberg, M.

    2014-08-01

    A beam cyclotron instability in a plasma composed of magnetized ions and electrons and unmagnetized, negatively charged dust is investigated using linear kinetic theory. We consider the case where an ion E × E drift leads to the excitation of a discrete wavenumber spectrum of waves with frequency on the order of the dust plasma frequency for propagation perpendicular to the magnetic field. The unstable wavelengths are short, on the order of the ion gyroradius. Collisions of charged particles with neutrals are taken into account, as well as ion-dust and dust-dust collisions, which can be significant at the lower pressures considered. The behavior of the instability for oblique propagation is also considered. Application to possible laboratory dusty magnetoplasma parameters is discussed.

  12. 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.

  13. 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.

  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. Determination of the frequency-controlling region of the current-driven electrostatic ion-cyclotron instability

    Microsoft Academic Search

    N. S. Wolf; R. Schrittwieser

    1985-01-01

    A small, axially moveable test coil is used to locally increase the magnetic field of a single-ended Q-machine. The influence of this additional field on the current-driven electrostatic ion-cyclotron instability (EICI) depends on its distance from the collector. Three different regions are found, and in the middle region, at a distance of several cm from the collector, the local magnetic

  17. Ion heating in the field-reversed configuration by rotating magnetic fields near the ion-cyclotron resonance

    PubMed

    Cohen; Glasser

    2000-12-11

    The trajectories of ions confined in a field-reversed configuration (FRC) equilibrium magnetic geometry and heated with a small-amplitude, odd-parity rotating magnetic field (RMF) have been studied with a Hamiltonian computer code. When the RMF frequency is in the ion-cyclotron range, explosive heating occurs. Higher-energy ions are found to have betatron-type orbits, preferentially localized near the FRC's midplane. These results are relevant to a compact magnetic-fusion-reactor design. PMID:11102199

  18. Abortion - medical

    MedlinePLUS

    Therapeutic medical abortion; Elective medical abortion; Induced abortion; Nonsurgical abortion ... A medical, or nonsurgical, abortion can be done within 7 weeks from the first day of the woman's last ...

  19. Medication Treatments

    MedlinePLUS

    ... medications are used to treat certain symptoms of Fragile X syndrome, as shown in the chart below. The NICHD ... of these medications in treating the symptoms of Fragile X syndrome, or for other conditions for which the medications ...

  20. Flat-top system of the DC-280 cyclotron

    NASA Astrophysics Data System (ADS)

    Gulbekyan, G. G.; Buzmakov, V. A.; Zarubin, V. B.; Ivanenko, I. A.; Kazarinov, N. Yu.; Karamysheva, G. A.; Franko, I.

    2013-07-01

    The flat-top cavity of the radio-frequency accelerating system designed at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, for the DC-280 cyclotron is described. The cyclotron is intended for increasing the capabilities and efficiency of experiments on the synthesis of super-heavy elements and an investigation of their nuclear physical and chemical properties. The DC-280 isochronous heavy-ion cyclotron will produce accelerated beam of ions in the range from neon to uranium. The parameters, design, and results of the experimental and 3D computer modeling of the flat-top cavity of the RF accelerating system of the DC-280 cyclotron are reported.

  1. Heavy-ion injection from tandems into an isochronous cyclotron

    SciTech Connect

    LeVine, M.J.; Chasman, C.

    1981-01-01

    A design has been realized for the injection of heavy ion beams generated by the BNL 3-stage tandem facility into a proposed isochronous cyclotron. The tandem beams are bunched into +- 1/sup 0/ R.F. phase (less than or equal to 0.5 nsec) in two stages. The beam is then injected into the cyclotron through a valley, past a hill, and into the next valley on to a stripper foil. Only a single steerer is required to make trajectory corrections for the different beams. Two achromats are used to regulate the tandem potential and to provide phase control. A final section of the injection optics provides matching of transverse phase space to the acceptance of the cyclotron. The calculations use realistic tandem emittances and magnetic fields for the cyclotron based on measurements with a model magnet.

  2. 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.

  3. 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 ...

  4. HISTORY of the UMH Medical Library The medical library of Cedars Medical Center was initially housed in a remove and relatively

    E-print Network

    Miami, University of

    HISTORY of the UMH Medical Library 1 The medical library of Cedars Medical Center was initially subscriptions were purchased through dues of the Medical Staff. Selections of material were based and Journals for the Small Medical Library. Requests from medical staff members were incorporated

  5. Production of radioisotopes in the ORNL 86-inch cyclotron

    Microsoft Academic Search

    J. W. Terry

    1981-01-01

    The radioisotope production facilities and programs of the 86-Inch Cyclotron are reviewed in this presentation. The 86-Inch Cyclotron is designed to accelerate protons to a maximum energy of 22 MeV for internal targets. These protons are used to bombard metals that are electroplated, potted or soldered to water-cooled plates. Additionally, metals and inorganic compounds are bombarded in water-cooled tube targets.

  6. 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

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

    Microsoft Academic Search

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

    2004-01-01

    In the previous study, we found the feasibility of a cyclotron-based BNCT using the Ta(p,n) neutrons at 90° bombarded by 50MeV protons, and the iron, AlF3, Al and 6LiF moderators by simulations using the MCNPX code. In order to validate the simulations to realize the cyclotron-based BNCT, we measured the epithermal neutron energy spectrum passing through the moderators with our

  8. 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

  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. One-dimensional modeling of transport in small stellarators

    Microsoft Academic Search

    K. J. S. Mertens; W. N. G. Hitchon; D. T. Anderson; J. L. Shohet

    1988-01-01

    An existing stellarator reactor transport code was modified to model small stellarator experiments. Changes were made in the treatment of neutrals, the atomic physics process, and the transport models. The authors investigated the extent to which the hollow density profiles experimentally detected during electron cyclotron resonance heating (ECRH) experiments in the interchangeable module stellarator (IMS), a small modular stellarator, can

  11. Development of a low-level RF control system for PET cyclotron CYCIAE-14

    NASA Astrophysics Data System (ADS)

    Li, Pengzhan; Yin, Zhiguo; Ji, Bin; Zhang, Tianjue; Zhao, Zhenlu

    2014-01-01

    The project of a 14 MeV PET cyclotron aiming at medical diagnosis and treatment was proposed and started at CIAE in 2010. The low-level RF system is designed to stabilize acceleration voltage and control the resonance of the cavity. Based on the experience of the existing CRM Cyclotron in CIAE, a new start-up sequence is developed and tested. The frequency sweeping is used to activate the RF system. Before the tuner is put into use, a new state called “DDS tuning” is applied to trace the resonance frequency to the designed value. This new option state helps to cover the tuning range, if a large frequency variation occurs because of a thermal cavity deformation. The logic control unit detects the spark, reflection, Pulse/CW state and the frequency of the RF source to perform all kinds of protection and state operations. The test bench and on-line test are carried out to verify the initial design.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. SPIE Medical Imaging Medical Imaging

    E-print Network

    Miga, Michael I.

    1 SPIE Medical Imaging 2006 1 Medical Imaging Fundamentals Kenneth H. Wong, Ph.D. Division of Computer Assisted Interventions and Medical Robotics (CAIMR) Imaging Science and Information Systems (ISIS) Center Department of Radiology Georgetown University SPIE Medical Imaging 2006 2 Main Themes · Describe

  19. Progress in the development of an H- ion source for cyclotrons

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    A multi-cusp DC H- ion source has been developed for cyclotrons in medical use. Beam optics of the H- ion beam is studied using a 2D beam trajectory code. The simulation results are compared with the experimental results obtained in the Mark I source, which has produced up to 16 mA H- ion beams. The optimum extraction voltages show good agreement between the calculation and the experimental results. A new ion source, Mark II source, is designed to achieve the next goal of producing an H- beam of 20 mA. The magnetic field configurations and the plasma electrode design are optimized for Cs-seeded operation. Primary electron trajectory simulation shows that primary electrons are confined well and the magnetic filter prevents the primary electrons from entering into the extraction region.

  20. Kinetic simulation of the electron-cyclotron maser instability: effect of a finite source size

    NASA Astrophysics Data System (ADS)

    Kuznetsov, A. A.; Vlasov, V. G.

    2012-03-01

    Context. The electron-cyclotron maser instability is widespread in the Universe, producing, e.g., radio emission of the magnetized planets and cool substellar objects. Diagnosing the parameters of astrophysical radio sources requires comprehensive nonlinear simulations of the radiation process taking into account the source geometry. Aims: We simulate the electron-cyclotron maser instability (i.e., the amplification of electromagnetic waves and the relaxation of an unstable electron distribution) in a very low-beta plasma. The model used takes into account the radiation escape from the source region and the particle flow through this region. Methods: We developed a kinetic code to simulate the time evolution of an electron distribution in a radio emission source. The model includes the terms describing the particle injection to and escape from the emission source region. The spatial escape of the emission from the source is taken into account by using a finite amplification time. The unstable electron distribution of the horseshoe type is considered. A number of simulations were performed for different parameter sets typical of the magnetospheres of planets and ultracool dwarfs. Results: The generated emission (corresponding to the fundamental extraordinary mode) has a frequency close to the electron cyclotron frequency and propagates across the magnetic field. Shortly after the onset of a simulation, the electron distribution reaches a quasi-stationary state. If the emission source region is relatively small, the resulting electron distribution is similar to that of the injected electrons and the emission intensity is low. In larger sources, the electron distribution may become nearly flat due to the wave-particle interaction, while the conversion efficiency of the particle energy flux into waves reaches 10-20%. We found good agreement of our model with the in situ observations in the source regions of auroral radio emissions of the Earth and Saturn. The expected characteristics of the electron distributions in the magnetospheres of ultracool dwarfs were obtained.

  1. Quantum Nature of Cyclotron Harmonics in Thermal Spectra of Neutron Stars

    NASA Astrophysics Data System (ADS)

    Suleimanov, V. F.; Pavlov, G. G.; Werner, K.

    2010-05-01

    Some isolated neutron stars (NSs) show harmonically spaced absorption features in their thermal soft X-ray spectra. The interpretation of the features as a cyclotron line and its harmonics has been suggested, but the usual explanation of the harmonics as caused by relativistic effects fails because the relativistic corrections are extremely small in this case. We suggest that the features, known as quantum oscillations, correspond to the peaks in the energy dependence of the free-free opacity in a quantizing magnetic field. The peaks arise when the transitions to new Landau levels become allowed with increasing the photon energy; they are strongly enhanced by the square-root singularities in the phase-space density of quantum states in the case when the free (non-quantized) motion is effectively one dimensional. To explore observable properties of these quantum oscillations, we calculate models of hydrogen NS atmospheres with B ~ 1010-1011 G (i.e., electron cyclotron energy E c,e ~ 0.1-1 keV) and T eff = 1-3 MK. Such conditions are thought to be typical for the so-called central compact objects in supernova remnants, such as 1E 1207.4-5209 in PKS 1209-51/52. We show that observable features at the electron cyclotron harmonics form at moderately large values of the quantization parameter, b eff ? E c,e /kT eff ~= 0.5-20. The equivalent widths of the features can reach ~100-200 eV; they grow with increasing b eff and are lower for higher harmonics.

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

    E-print Network

    Bosko, Andrey

    2005-11-01

    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...

  3. 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

  4. Design and construction of a cyclotron capable of accelerating protons to 2 MeV

    E-print Network

    Dewan, Leslie

    2007-01-01

    This thesis describes the design and construction of a cyclotron capable of accelerating protons to 2 MeV. A cyclotron is a charged particle accelerator that uses a magnetic field to confine particles to a spiral flight ...

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

    E-print Network

    Bosko, Andrey

    2005-11-01

    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...

  6. 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 ...

  7. Medication Errors

    MedlinePLUS

    ... Risk Management (PDF - 1.1MB) Draft Guidance for Industry and Food and Drug Administration Staff - Applying Human Factors and Usability Engineering to Optimize Medical Device Design Spotlight Guidance for Industry: Safety Considerations for Product Design to Minimize Medication ...

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

    PubMed

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

    2008-10-01

    A 128 channel two-dimensional electron cyclotron emission imaging system collects time-resolved 16x8 images of T(e) profiles and fluctuations on the TEXTOR tokamak. Electron cyclotron emission imaging (ECEI) is undergoing significant changes which promise to revolutionize and extend its capabilities far beyond what has been achieved to date. These include the development of a minilens array configuration with increased sensitivity antennas, a new local oscillator pumping scheme, enhanced electron cyclotron resonance heating shielding, and a highly flexible optical design with vertical zoom capability. Horizontal zoom and spot size (rf bandwidth) capabilities are also being developed with new ECEI electronics. An interface module is under development to remotely control all key features of the new ECEI instrument, many of which can be changed during a plasma discharge for maximum flexibility. PMID:19044590

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

    SciTech Connect

    Zhang, P.; Domier, C. W.; Liang, T.; Kong, X.; Tobias, B.; Shen, Z.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Park, H. [Pohang University of Science and Technology, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Classen, I. G. J.; Pol, M. J. van de; Donne, A. J. H.; Jaspers, R. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, 3430 BE Niewuwegein (Netherlands)

    2008-10-15

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

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

    SciTech Connect

    Vega-Carrillo, Hector Rene [Unidades Academicas: Estudios Nucleares e Ing. Electrica. Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas, Zac. Mexico (Mexico); Mendez, Roberto [Universidad Europea Miguel de Cervantes, Valladolid (Spain); Iniguez, Maria Pilar [Facultad de Ciencias de la Universidad de Valladolid, Valladolid (Spain); Marti-Climent, Joseph; Penuelas, Ivan [Servicio de Medicina Nuclear, Clinica Universitaria de la Universidad de Navarra (Spain); Barquero, Raquel [Hospital Universitario Rio Hortega, Valladolid (Spain)

    2006-09-08

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

  11. A laboratory study of collisional electrostatic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Suszcynsky, D. M.; Cartier, S. L.; Merlino, R. L.; Dangelo, N.

    1986-01-01

    The effects of neutral-particle collisions on electrostatic ion cyclotron instability are analyzed. Experiments were conducted in the Q machine of Motley (1975) with a cesium plasma in which the neutral gas pressure in the main chamber varied from about 5 microtorr-10 mtorr. The relation between electrostatic ion cyclotron wave amplitude and frequency and neutral argon pressure is examined. It is observed that over the full range of neutral pressure the frequency changes by less than 10 percent and the ion cyclotron waves continue to be excited and reach amplitudes of at least several percent at values of the neutral pressure where the ion-neutral collision frequency/ion gyrofrequency is about 0.3.

  12. 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

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

    NASA Astrophysics Data System (ADS)

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

    2003-07-01

    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" Cyclotron to deliver high intensity light particle and heavy ion beams, to be used 1.) for production of rare isotopes for acceleration in the K500 Cyclotron and 2.) as precursor beams to produce significantly higher intensity stripping and fragmentation beams in our MARS spectrometer. In addition to greatly extending the reach of the present TAMU research program, this facility could play a much wider role in support of the national accelerator based scientific research effort. This facility could also prove to be very useful for early testing of techniques to be employed in the Rare Isotope Accelerator, RIA, and in educating younger scientists for the RIA era.

  14. Cavity Control in a Single-Electron Quantum Cyclotron: An Improved Measurement of the

    E-print Network

    Hanneke, David

    Cavity Control in a Single-Electron Quantum Cyclotron: An Improved Measurement of the Electron Cyclotron: An Improved Measurement of the Electron Magnetic Moment Abstract A single electron in a quantum cyclotron yields new measurements of the electron magnetic moment, given by g/2 = 1.001 159 652 180 73 (28

  15. 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 00808-9 PACS number s : 84.40.Ik I. INTRODUCTION Cyclotron-resonance masers CRM's 1 have been stud- ied

  16. 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, 84.40.Ik, 84.47. w I. INTRODUCTION Cyclotron-resonance masers CRMs and gyrotrons are known as high

  17. 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

  18. Design and Construction of the Axial Injection System for the 88Inch Cyclotron

    Microsoft Academic Search

    D. J. Clark; R. Burger; A. Carneiro; D. Elo; P. Frazier; A. Luccio; D. Morris; M. Renkas; F. Resmini

    1969-01-01

    A new axial injection system for the 88-inch cyclotron has been constructed. It transports beams from external ion sources axially through the magnet yoke to the median plane of the cyclotron. The optical elements include a bending magnet, electric quadrupoles, and the magnetic field of the cyclotron. Beam monitoring is done with scanning wires. phosphor plates and Faraday cups.

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

    NASA Astrophysics Data System (ADS)

    Asner, D. M.; Bradley, R. F.; de Viveiros, L.; Doe, P. J.; Fernandes, J. L.; Fertl, M.; Finn, E. C.; Formaggio, J. A.; Furse, D.; Jones, A. M.; Kofron, J. N.; LaRoque, B. H.; Leber, M.; McBride, E. L.; Miller, M. L.; Mohanmurthy, P.; Monreal, B.; Oblath, N. S.; Robertson, R. G. H.; Rosenberg, L. J.; Rybka, G.; Rysewyk, D.; Sternberg, M. G.; Tedeschi, J. R.; Thümmler, T.; VanDevender, B. A.; Woods, N. L.; Project 8 Collaboration

    2015-04-01

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

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

    PubMed

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

    2015-04-24

    It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Although first derived in 1904, cyclotron radiation from a single electron orbiting in a magnetic field has never been observed directly. We demonstrate single-electron detection in a novel radio-frequency spectrometer. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay end point, and this work demonstrates a fundamentally new approach to precision beta spectroscopy for future neutrino mass experiments. PMID:25955048

  1. Heavy ion acceleration using 224 cm cyclotron at Kolkata

    NASA Astrophysics Data System (ADS)

    Mallik, C.

    2001-12-01

    The cyclotron at Kolkata after accelerating light ions for twenty years was shut down in early 1997 for modification of the central region and connecting the 6.4 Ghz ECR source to the cyclotron. After carrying out several modifications and installation of the axial injection line the beam trials were started. The first heavy ion beam was obtained in early '98. Using oxygen as the test beam most of the initial debugging was done. Now the beams have been made available to the users for experiments. The second ECR ion source has been added to increase the range of energy and ion species.

  2. Residual radioactivity in a cyclotron and its surroundings

    SciTech Connect

    Phillips, A.B.; Prull, D.E.; Ristinen, R.A.; Kraushaar, J.J.

    1986-09-01

    Neutron-induced gamma-ray-emitting radionuclides in components and surroundings of the University of Colorado 1.3-m sector-focusing cyclotron have been measured with Ge(Li) and HPGe detectors. These measurements were made before decommissioning of the cyclotron and before approving release of the accelerator components and building space for other uses. In addition to the activities expected from previous published work, 13.3-y 152Eu and 8.6-y 154Eu were found in the concrete shielding with specific activities of tens of becquerels per kilogram (a few nanocuries per kilogram).

  3. 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.

  4. Temperature-resonant cyclotron spectra in confined geometries.

    PubMed

    Pototsky, A; Hänggi, P; Marchesoni, F; Savel'ev, S

    2011-07-01

    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. PMID:21867113

  5. 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.

  6. 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.

  7. A compact cost-effective beamline for a PET Cyclotron

    NASA Astrophysics Data System (ADS)

    Dehnel, M. P.; Jackle, P.; Roeder, M.; Stewart, T.; Theroux, J.; Brasile, J. P.; Sirot, P.; Buckley, K. R.; Bedue, M.

    2007-08-01

    Most commercial PET Cyclotrons have targets mounted on or near the main cyclotron vacuum chamber. There is often little or no system capability for centering or focusing the extracted beam on target to achieve maximum production. This paper describes the ion-optics, design and development of a compact cost-effective beamline comprised of low activation and radiation resistant materials. The beamline, complete with suitable diagnostic devices, permits the extracted proton beam to be centered ( X- Y steering magnet), and focused (quadrupole doublet) on target eliminating unnecessary beamspill and ensuring high production.

  8. ELECTRON CYCLOTRON CURRENT DRIVE EFFICIENCY IN GENERAL TOKAMAK GEOMETRY

    SciTech Connect

    LIN-LUI,Y.R; CHAN,V.S; PRATER,R

    2003-03-01

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

  9. Development of microwave ion source and low energy beam transport system for high current cyclotron

    NASA Astrophysics Data System (ADS)

    Pandit, V. S.; Sing Babu, P.; Goswami, A.; Srivastava, S.; Misra, A.; Chatterjee, Mou; Nabhiraj, P. Y.; Yadav, R. C.; Bhattacharya, S.; Roy, S.; Nandi, C.; Pal, G.; Thakur, S. K.

    2013-12-01

    A 2.45 GHz microwave ion source and a low energy beam transport system have been developed to study the high intensity proton beam injection into a 10 MeV, 5 mA compact cyclotron. We have extracted proton beam more than 10 mA at 80 kV as measured by the DCCT after the extraction and a well collimated beam of 7 mA (through 1 cm × 1 cm slit) at the faraday cup 1.5 m away from the source. The transport of protons from the ion source in the presence of H2+, H3+ species has been studied using PIC simulations through our transport line which consists of two solenoids. We have also installed a small dipole magnet with similar field as that of the cyclotron along with vacuum chamber, spiral inflector and few diagnostic elements at the end of the beam line. In the preliminary testing of inflection, we achieved 1 mA beam on the faraday cup at the exit of inflector with ?60% transmission efficiency.

  10. 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

  11. On the interactions of transverse ion-cyclotron waves with ions in solar wind plasma

    NASA Astrophysics Data System (ADS)

    Bourouaine, S.; Marsch, E.; Neubauer, F. M.

    2010-12-01

    We show the evidence of the ion-cyclotron dissipation mechanism in solar wind plasma using Helios data. From our statistical analysis we found that the wave power of high-frequency transverse waves (having frequencies between 0.01 and 1 normalized to the proton gyrofrequency in the plasma frame) correlates with both, the proton temperature anisotropy, T?}/T{? , and the normalized differential speed, V{? p}/VA, between alpha particles and protons. Furthermore, when this speed stays below 0.5, then the alpha-particle temperature anisotropy correlates positively with the relative power of the transverse waves. However, if V{? p}/VA is larger than 0.6, then the alpha-particle temperature anisotropy tends to decrease towards values below unity, despite the presence of transverse waves with relatively large amplitudes. For small relative wave amplitude, it is found that alpha particles can even be heated more strongly than protons when the alpha-to-electron density ratio nearly or below 0.01. Our findings are in good agreement with predictions of kinetic theory for the resonant interaction of ions with Alfvén-cyclotron waves and for the resulting wave dissipation. Therefore, the solar wind turbulence may lead to the presence of parallel (or quasi-parallel) transverse high-frequency waves, e.g, Alfvén-cylcotron waves.

  12. Medical waste generation in selected clinical facilities in Taiwan

    Microsoft Academic Search

    Y. W. Cheng; K.-C. Li; F. C. Sung

    2010-01-01

    This study investigated the type and amount of medical waste generated from small clinical facilities in Taiwan. We sampled 200 small medical establishments, with few or no patient beds, to survey the wastes generated and disposed. The surveyed medical facilities consisted of four groups including private clinics, medical laboratories, blood centers and public clinics. Private clinics providing surgical, dental, obstetrical,

  13. 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.

  14. Do we need medical leadership or medical engagement?

    PubMed

    Spurgeon, Peter; Long, Paul; Clark, John; Daly, Frank

    2015-07-01

    Purpose - The purpose of this paper is to address issues of medical leadership within health systems and to clarify the associated conceptual issues, for example, leadership versus management and medical versus clinical leadership. However, its principle contribution is to raise the issue of the purpose or outcome of medical leadership, and, in this respect, it argues that it is to promote medical engagement. Design/methodology/approach - The approach is to provide evidence, both from the literature and empirically, to suggest that enhanced medical engagement leads to improved organisational performance and, in doing so, to review the associated concepts. Findings - Building on current evidence from the UK and Australia, the authors strengthen previous findings that effective medical leadership underpins the effective organisational performance. Research limitations/implications - There is a current imbalance between the size of the databases on medical engagement between the UK (very large) and Australia (small but developing). Practical implications - The authors aim to equip medical leaders with the appropriate skill set to promote and enhance greater medical engagement. The focus of leaders in organisations should be in creating a culture that fosters and supports medical engagement. Social implications - This paper provides empowerment of medical professionals to have greater influence in the running of the organisation in which they deliver care. Originality/value - The paper contains, for the first time, linked performance data from the Care Quality Commission in the UK and from Australia with the new set of medical engagement findings. PMID:26083633

  15. 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.

  16. Radiation effects test facility at the Indiana University Cyclotron Facility

    Microsoft Academic Search

    C. C. Foster; S. L. Casey; A. L. Johnson; P. Miesle; N. Sifri; A. H. Skees; K. M. Murray

    1997-01-01

    The beam line end station, associated instrumentation and dosimetry used at the Indiana University Cyclotron Facility for radiation effects research and testing with up to 200 MeV protons are described. Access to beam for radiation effects studies is greatly enhanced by the capability to share beam with other users on a millisecond time scale. Use of shared beam mandates that

  17. Simulation of the current-driven electrostatic ion cyclotron instability

    Microsoft Academic Search

    P. L. Pritchett; M. Ashour-Abdalla; J. M. Dawson

    1981-01-01

    Results are presented of a self-consistent particle simulation of the growth and saturation of electrostatic ion cyclotron (EIC) waves along auroral field lines. The driving mechanism for the waves is an initial drifting Maxwellian distribution for the electrons. The magnetic field is taken to lie in the simulation plane, so that modes such as the ion acoustic instability and the

  18. Graduate StudieS 2014 National Superconducting Cyclotron Laboratory

    E-print Network

    by NASA. National Superconducting Cyclotron Laboratory Michigan State University 640 South Shaw Lane, East in accelerator technology and experimental equipment. During the past half-century, nuclear science research result as NSCL and subsequently FRIB push the envelope at the sensitivity frontier of field. Progress

  19. Dynamic effects on cyclotron scattering in pulsar accretion columns

    SciTech Connect

    Brainerd, J.J.; Meszaros, P. (NASA, Marshall Space Flight Center, Huntsville, AL (USA) Pennsylvania State Univ., University Park (USA))

    1991-03-01

    A resonant scattering model for photon reprocessing in a pulsar accretion column is presented. The accretion column is optically thin to Thomson scattering and optically thick to resonant scattering at the cyclotron frequency. Radiation from the neutron star surface propagates freely through the column until the photon energy equals the local cyclotron frequency, at which point the radiation is scattered, much of it back toward the star. The radiation pressure in this regime is insufficient to stop the infall. Some of the scattered radiation heats the stellar surface around the base of the column, which adds a softer component to the spectrum. The partial blocking by the accretion column of X-rays from the surface produces a fan beam emission pattern. X-rays above the surface cyclotron frequency freely escape and are characterized by a pencil beam. Gravitational light bending produces a pencil beam pattern of column-scattered radiation in the antipodal direction, resulting in a strongly angle-dependent cyclotron feature. 31 refs.

  20. Measuring the Cyclotron State of a Trapped Electron

    E-print Network

    Stefano Mancini; Paolo Tombesi

    1997-07-04

    We propose the cyclotron state retrieval of an electron trapped in a Penning trap by using different measurement schemes based on suitable modifications of the applied electromagnetic fields and exploiting the axial degree of freedom as a probe. A test for matter-antimatter symmetry of the quantum state is proposed.

  1. Cyclotron maser emission of auroral Z mode radiation

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  2. 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. By analogy, extrasolar planets are also expected to be a source of non-thermal radio emission frequencies for the full catalog of known extrasolar planets. Four target planets were selected

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

    SciTech Connect

    Lyneis, C.M.

    1987-03-01

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

  4. 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)

  5. 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

  6. Characteristic Experimentations of Degrader and Scatterer at MC50 Cyclotron

    Microsoft Academic Search

    S. K. Lee; H. R. Lee; K. R. Kim; B. S. Park; B. H. Choi

    2005-01-01

    Building proton beam user facilities, especially deciding beam energy level, depends on the attached proton accelerator and users' needs. To adjust beam energy level, two methods are generally used. One is to directly adjust the beam in the accelerator. The other is to adjust beam energy after extracting from the accelerator. Degrader\\/Scatterer System has been installed in the MC-50 Cyclotron

  7. High Power Ion Cyclotron Heating in the VASIMR

    Microsoft Academic Search

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

    2009-01-01

    The Variable Specific Impulse Magnetoplasma Rocket (VASIMR®) is an electric propulsion system under development at Ad Astra Rocket Company that utilizes several processes of ion acceleration and heating that occur in the Birkeland currents of an auroral arc system. Among these processes are parallel electric field acceleration, lower hybrid resonance heating, and ion cyclotron resonance heating. The VASIMR® is capable

  8. Dynamic effects on cyclotron scattering in pulsar accretion columns

    NASA Technical Reports Server (NTRS)

    Brainerd, J. J.; Meszaros, P.

    1991-01-01

    A resonant scattering model for photon reprocessing in a pulsar accretion column is presented. The accretion column is optically thin to Thomson scattering and optically thick to resonant scattering at the cyclotron frequency. Radiation from the neutron star surface propagates freely through the column until the photon energy equals the local cyclotron frequency, at which point the radiation is scattered, much of it back toward the star. The radiation pressure in this regime is insufficient to stop the infall. Some of the scattered radiation heats the stellar surface around the base of the column, which adds a softer component to the spectrum. The partial blocking by the accretion column of X-rays from the surface produces a fan beam emission pattern. X-rays above the surface cyclotron frequency freely escape and are characterized by a pencil beam. Gravitational light bending produces a pencil beam pattern of column-scattered radiation in the antipodal direction, resulting in a strongly angle-dependent cyclotron feature.

  9. Radiation safety and quality control in the cyclotron laboratory.

    PubMed

    Sharma, Sushil; Krause, Gregory; Ebadi, Manuchair

    2006-01-01

    Radiation safety was determined to maintain quality control in the cyclotron laboratory. Based on the results of 438 runs in the Faraday cup (20 microA for 10 min), 20 runs on 18O-water target (40 microA for 2 h) and 10 runs on 18O-gas targets (30 microA for 45 min), we have established that occupationally exposed workers remain 10 +/- 5 times below federal regulatory limits (FRLs) in the cyclotron vault, 30 +/- 8 times below FRL in the radiochemistry laboratory and 200 +/- 10 times below the FRL outside the cyclotron laboratory during beam operation. (The FRL for unrestricted area are <20 microSv in 1 h.) The non-occupationally exposed workers serving in offices in the vicinity of the cyclotron vault within 100 m distance remained 200 times below the FRL irrespective of beam being on or off, suggesting that routine beam operation of 40 microA for 2 h once a day during office hours is safe provided quality control and system performance measures as discussed in this report are strictly maintained. PMID:16497875

  10. COUPLED HELICON-CYCLOTRON MODES: THEORY AND EXPERIMENT

    E-print Network

    Chen, Francis F.

    to the normal H mode, and the larger one to the TG mode. As B0 is decreased, the roots approach each other [3] and Boswell [4] and have recently been re-examined by Chen and Arnush [5]. The normal modeCOUPLED HELICON-CYCLOTRON MODES: THEORY AND EXPERIMENT Francis F. Chen, Donald Arnush, John D

  11. Surface treatment of HV electrodes for superconducting cyclotron beam extraction

    Microsoft Academic Search

    G. Cuttone; C. Marchetta; L. Torrisi; G. Delta Mea; A. Quaranta; V. Rigato; S. Zandolin

    1997-01-01

    At the Istituto Nazionale di Fisica Nucleare Laboratorio Nazionale del Sud of Catania, a K=800 superconducting cyclotron is in operation since 1994. The accelerator beam extraction is accomplished using electrostatic deflectors constituted by HV electrodes generating electric fields to 140 kV\\/cm in 6 to 8 mm gaps. The electrostatic performance is strongly dependent on the presence of high magnetic fields

  12. A phase-imaging technique for cyclotron-frequency measurements

    NASA Astrophysics Data System (ADS)

    Eliseev, S.; Blaum, K.; Block, M.; Dörr, A.; Droese, C.; Eronen, T.; Goncharov, M.; Höcker, M.; Ketter, J.; Ramirez, E. Minaya; Nesterenko, D. A.; Novikov, Yu. N.; Schweikhard, L.

    2014-01-01

    A novel approach to mass measurements at the 10-9 level for short-lived nuclides with half-lives well below one second is presented. It is based on the projection of the radial ion motion in a Penning trap onto a position-sensitive detector. Compared with the presently employed time-of-flight ion-cyclotron-resonance technique, the novel approach is 25-times faster and provides a 40-fold gain in resolving power. Moreover, it offers a substantially higher sensitivity since just two ions are sufficient to determine the ion's cyclotron frequency. Systematic effects specific to the technique that can change the measured cyclotron frequency are considered in detail. It is shown that the main factors that limit the maximal accuracy and resolving power of the technique are collisions of the stored ions with residual gas in the trap, the temporal instability of the trapping voltage, the anharmonicities of the trapping potential and the uncertainty introduced by the conversion of the cyclotron to magnetron motion.

  13. Characteristics of electron-cyclotron-resonance-heated tokamak power reactors

    Microsoft Academic Search

    S. M. Wolfe; D. R. Cohn; R. J. Temkin; K. Kreischer

    1979-01-01

    The characteristics of electron-cyclotron resonance-heated tokamak reactors are determined, based on the requirements for wave propagation and absorption in the plasma. Heating at both the fundamental and the second harmonic is considered, and constraints on the toroidal beta and the minimum magnetic field required to obtain suitable fusion power densities are derived. The magnetic field and temperature necessary to achieve

  14. 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

  15. AXIAL INJECTION CHANNEL OF THE DC350 CYCLOTRON

    Microsoft Academic Search

    G. G. Gulbekyan; S. L. Bogomolov; V. V. Bekhterev; I. V. Kalagin; N. Yu. Kazarinov; M. V. Khabarov; V. N. Melnikov; M. N. Sazonov; Kairat K. Kadyrzhanov

    Axial injection channel of the DC-350 cyclotron is presented. It is intended for transportation of the high intensity ion beam from Li to Bi obtained in the superconducting ECR-ion source (SECRIS). The sharp shortening of the distance between SECRIS and the analyzing bending magnet allow removing the focusing elements between the SECRIS and the analyzing magnet. This reduces the negative

  16. Visible Light Emission of Electron Cyclotron Resonance Plasmas

    Microsoft Academic Search

    Richárd Racz; Sándor Biri; József Palinkas

    2011-01-01

    Electron cyclotron resonance (ECR) plasmas gener- ated by microwave and confined by magnetic field are, in most cases, generated for highly charged ion production followed by injection of them into an accelerator. The ECR plasma itself usually cannot be seen because it is deeply hidden in the center of the facility. In the Institute of Nuclear Research (ATOMKI), the ECR

  17. Technological issues of ion cyclotron heating of fusion plasmas

    Microsoft Academic Search

    D. Q. Hwang; C. M. Fortgang

    1985-01-01

    With the recent promising results of plasma heating using electromagnetic waves (EM waves) in the ion cyclotron range of frequency (ICRF) on the Princeton Large Torus (PLT) tokamak the feasibility of employing ICRF heating to a reactor-like magnetic confinement device is increasing. The high power ICRF experiments funded on JET (Joint European Torus in England) and JT-60 (in Japan) will

  18. 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.

  19. A Pilot Trial of Serial 18F-Fluorodeoxyglucose Positron Emission Tomography in Patients With Medically Inoperable Stage I Non-Small-Cell Lung Cancer Treated With Hypofractionated Stereotactic Body Radiotherapy

    SciTech Connect

    Henderson, Mark A., E-mail: mahender@iupui.ed [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States); Hoopes, David J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States); Department of Radiation Oncology, Wright-Patterson Medical Center, Wright-Patterson Air Force Base, OH (United States); Fletcher, James W.; Lin, P.-F.; Tann, Mark [Department of Nuclear Medicine, Indiana University School of Medicine, Indianapolis, IN (United States); Yiannoutsos, Constantin T. [Division of Biostatistics, Indiana University School of Medicine, Indianapolis, IN (United States); Williams, Mark D. [Pulmonary Division, Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, IN (United States); Fakiris, Achilles J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States); McGarry, Ronald C. [Department of Radiation Medicine, University of Kentucky, Lexington, KY (United States); Timmerman, Robert D. [Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX (United States)

    2010-03-01

    Purpose: Routine assessment was made of tumor metabolic activity as measured by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in Stage I non-small-cell lung cancer (NSCLC). This report describes PET correlates prospectively collected after stereotactic body radiotherapy (SBRT) for patients with medically inoperable NSCLC. Methods and Materials: 14 consecutive patients with medically inoperable Stage I NSCLC were enrolled. All patients received SBRT to 60-66 Gy in three fractions. Patients underwent serial planned FDG-PET/computed tomography fusion imaging before SBRT and at 2, 26, and 52 weeks after SBRT. Results: With median follow-up of 30.2 months, no patients experienced local failure. One patient developed regional failure, 1 developed distant failure, and 1 developed a second primary. The median tumor maximum standardized uptake value (SUV{sub max}) before SBRT was 8.70. The median SUV{sub max} values at 2, 26, and 52 weeks after SBRT were 6.04, 2.80, and 3.58, respectively. Patients with low pre-SBRT SUV were more likely to experience initial 2-week rises in SUV, whereas patients with high pre-SBRT SUV commonly had SUV declines 2 weeks after treatment (p = 0.036). Six of 13 patients had primary tumor SUV{sub max} >3.5 at 12 months after SBRT but remained without evidence of local disease failure on further follow-up. Conclusions: A substantial proportion of patients may have moderately elevated FDG-PET SUV{sub max} at 12 months without evidence of local failure on further follow-up. Thus, slightly elevated PET SUV{sub max} should not be considered a surrogate for local treatment failure. Our data do not support routine serial FDG-PET/computed tomography for follow-up of patients receiving SBRT for Stage I NSCLC.

  20. 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.

  1. Decontamination and decommissioning of the 60-inch Cyclotron facility at Argonne National Laboratory-East project final report

    Microsoft Academic Search

    E. Collins; J. Boyance; D. Tinnin; A. Williams

    2001-01-01

    This final report of the decontamination and decommissioning (D&D) of the Argonne National Laboratory-East (ANL-E) 60'' Cyclotron Accelerator Facility contains descriptions and evaluations of activities performed, and results obtained in connection with the Cyclotron D&D Project. It provides the following information: Objective of the Cyclotron D&D Project; A brief history of the Cyclotron facility; Overall descriptions of the Cyclotron facility

  2. Nonlinear response of magnetic islands to localized electron cyclotron current injection

    NASA Astrophysics Data System (ADS)

    Borgogno, D.; Comisso, L.; Grasso, D.; Lazzaro, E.

    2014-06-01

    The magnetic island evolution under the action of a current generated externally by electron cyclotron wave beams is studied using a reduced resistive magnetohydrodynamics plasma model. The use of a two-dimensional reconnection model shows novel features of the actual nonlinear evolution as compared to the zero-dimensional model of the generalized Rutherford equation. When the radio frequency control is applied to a small magnetic island, the complete annihilation of the island width is followed by a spatial phase shift of the island, referred as "flip" instability. On the other hand, a current-drive injection in a large nonlinear island can be accompanied by the occurrence of a Kelvin-Helmholtz instability. These effects need to be taken into account in designing tearing mode control systems based on radio frequency current-drive.

  3. Effect of turbulence on electron cyclotron current drive and heating in ITER

    E-print Network

    Casson, F J; Angioni, C; Buchholz, R; Peeters, A G

    2014-01-01

    Non-linear local electromagnetic gyrokinetic turbulence simulations of the ITER standard scenario H-mode are presented for the q=3/2 and q=2 surfaces. The turbulent transport is examined in regions of velocity space characteristic of electrons heated by electron cyclotron waves. Electromagnetic fluctuations and sub-dominant micro-tearing modes are found to contribute significantly to the transport of the accelerated electrons, even though they have only a small impact on the transport of the bulk species. The particle diffusivity for resonant passing electrons is found to be less than 0.15 m^2/s, and their heat conductivity is found to be less than 2 m^2/s. Implications for the broadening of the current drive and energy deposition in ITER are discussed.

  4. Cyclotron production of I-123: An evaluation of the nuclear reactions which produce this isotope

    NASA Technical Reports Server (NTRS)

    Sodd, V. J.; Scholz, K. L.; Blue, J. W.; Wellman, H. N.

    1970-01-01

    The use of the various nuclear reactions is described by which I-123,a low radiation dose radiopharmaceutical, can be cyclotron-produced. Methods of directly producing I-123 and those which indirectly produce the radionuclide through the beta (+) decay of its nautral precursor, Xe-123. It is impossible to separate from the radioiodine contaminants, notably I-124, which occur in the direct method. Thus, it is preferable to produce pure I-123 from Xe-123 which is easily separated from the radioiodines. Among the characteristics of I-123 is the capability of reducing the patient dose in a thyroid uptake measurement to a very small percentage of that delivered by the more commonly used I-131.

  5. Solid material evaporation into an electron cyclotron resonance source by laser ablation

    NASA Astrophysics Data System (ADS)

    Harkewicz, R.; Stacy, J.; Greene, J.; Pardo, R. C.

    1994-04-01

    In an effort to explore new methods of producing ion beams from solid materials, a laser-ablation technique for evaporating materials directly into an electron cyclotron resonance (ECR) ion source plasma was developed. A pulsed NdYaG laser with approximately 25 W average power and peak power density on the order of 107 W/cm2 has been used off-line to measure ablation rates of various materials as a function of peak laser power. The benefits anticipated from the successful demonstration of this technique include the ability to use very small quantities of materials efficiently, improved material efficiency of incorporation into the ECR plasma, and decoupling of the material evaporation process from the ECR source tuning operation. The results of these tests are reported herein and the design is described for incorporating such a system directly with the Argonne Tandem Linac Accelerator System Positive Ion Injector ECR (ATLAS PII-ECR) ion source.

  6. Improved operation of the Michelson interferometer electron cyclotron emission diagnostic on DIII-D

    SciTech Connect

    Austin, M.E.; Ellis, R.F. [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742-3511 (United States)] [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742-3511 (United States); Doane, J.L. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)] [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); James, R.A. [Lawrence Livermore National Laboratory, Livermore, California 94551-9090 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94551-9090 (United States)

    1997-01-01

    The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and a reduction of calibration error from 15{percent} to 5{percent}. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter-wavelength frequency and very stable transmission characteristics over time. Further reduction in error was realized through special signal processing of the calibration and plasma interferograms. {copyright} {ital 1997 American Institute of Physics.}

  7. Magnetic field calculation for a 10 MeV positron emission tomography cyclotron

    SciTech Connect

    Chen Dezhi; Liu Kaifeng; Yang Jun; Li Dong; Qin Bin; Xiong Yongqian [State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Chen Zihao [Central Southern Electrical Power Design Institute, Wuhan 430071 (China)

    2013-05-15

    The magnetic field calculation and correction for a 10 MeV positron emission tomography cyclotron is presented. 3D TOSCA analysis results are compared with the measured data, and the calculation error is used to calibrate the B-H curve to obtain a very precise finite element method estimator, which is used to predict the correction of the magnet pole for achieving the isochronous field. The isochronous field error is approximated with the effects of a set of standard patches. On the assumption that the effect of each small patch is proportional to its surface, the correction of the magnet pole is found by solving a system of equations using the least square scheme. The magnet shimming is performed and the measured magnetic field is found in good agreement with the prediction, with an error less than 2 G.

  8. Improved ion optics for introduction of ions into a 9.4-T Fourier transform ion cyclotron resonance mass spectrometer

    SciTech Connect

    Chen, Yu; Leach, Franklin E.; Kaiser, Nathan K.; Dang, Xibei; Ibrahim, Yehia M.; Norheim, Randolph V.; Anderson, Gordon A.; Smith, Richard D.; Marshall, Alan G.

    2015-01-01

    Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry provides unparalleled mass accuracy and resolving power.[1],[2] With electrospray ionization (ESI), ions are typically transferred into the mass spectrometer through a skimmer, which serves as a conductance-limiting orifice. However, the skimmer allows only a small fraction of incoming ions to enter the mass spectrometer. An ion funnel, originally developed by Smith and coworkers at Pacific Northwest National Laboratory (PNNL)[3-5] provides much more efficient ion focusing and transfer. The large entrance aperture of the ion funnel allows almost all ions emanating from a heated capillary to be efficiently captured and transferred, resulting in nearly lossless transmission.

  9. Medical Terminology.

    ERIC Educational Resources Information Center

    Mercer County Community Coll., Trenton, NJ.

    This document is one of a series of student workbooks developed for workplace skill development courses or workshops by Mercer County Community College (New Jersey) and its partners. Designed to help employees of medical establishments learn medical terminology, this course provides information on basic word structure, body parts, suffixes and…

  10. Medical Management of Small Abdominal Aortic Aneurysms

    Microsoft Academic Search

    B. Timothy Baxter; Michael C. Terrin; Ronald L. Dalman

    2010-01-01

    Abdominal aortic aneurysm is a common condition that may be lethal when it is unrecognized. Current guidelines suggest repair as the aneurysm diameter reaches 5.0 to 5.5 cm. Most aortic aneurysms are detected incidentally when imaging is done for other purposes or through screening programs. Ninety percent of these aneurysms are below the threshold for intervention at the time of

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  12. Remote target removal for the Oak Ridge 86-inch Cyclotron

    SciTech Connect

    Walls, A.A.

    1982-01-01

    A remotely operated target remover has been plaed in operation at the 86-Inch Cyclotron located in Oak Ridge. The system provides for the remote removal of a target from inside the cyclotron, loading it into a cask, and the removal of the cask from the 1.5 m (5-ft) shielding walls. The remote system consists of multiple electrical and pneumatically operated equipment which is designed for controlled step-by-step operation, operated with an electrical control panel, and monitored by a television system. The target remover has reduced the radiation exposures to operating personnel at the facility and has increased the effective operating time. The system is fast, requires a minimum of skill to operate, and has demonstrated both reliability and durability.

  13. Ion Behavior in an Electrically Compensated Ion Cyclotron Resonance Trap

    PubMed Central

    Brustkern, Adam M.; Rempel, Don L.; Gross, Michael L.

    2010-01-01

    We recently described a new electrically compensated trap in FT ion cyclotron resonance mass spectrometry and developed a means of tuning traps of this general design. Here, we describe a continuation of that research by comparing the ion transient lifetimes and the resulting mass resolving powers and signal-to-noise (S/N) ratios that are achievable in the compensated vs. uncompensated modes of this trap. Transient lifetimes are ten times longer under the same conditions of pressure, providing improved mass resolving power and S/N ratios. The mass resolving power as a function of m/z is linear (log-log plot) and nearly equal to the theoretical maximum. Importantly, the ion cyclotron frequency as a function of ion number decreases linearly in accord with theory, unlike its behavior in the uncompensated mode. This linearity should lead to better control in mass calibration and increased mass accuracy than achievable in the uncompensated mode. PMID:21499521

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  16. Aharonov-Bohm Effect in Cyclotron and Synchrotron Radiations

    E-print Network

    Bagrov, V G; Levin, A; Tlyachev, V B

    2000-01-01

    We study the impact of Aharonov-Bohm solenoid on the radiation of a charged particle moving in a constant uniform magnetic field. With this aim in view, exact solutions of Klein-Gordon and Dirac equations are found in the magnetic-solenoid field. Using such solutions, we calculate exactly all the characteristics of one-photon spontaneous radiation both for spinless and spinning particle. Considering non-relativistic and relativistic approximations, we analyze cyclotron and synchrotron radiations in detail. Radiation peculiarities caused by the presence of the solenoid may be considered as a manifestation of Aharonov-Bohm effect in the radiation. In particular, it is shown that new spectral lines appear in the radiation spectrum. Due to angular distribution peculiarities of the radiation intensity, these lines can in principle be isolated from basic cyclotron and synchrotron radiation spectra

  17. Aharonov-Bohm effect in cyclotron and synchrotron radiations

    NASA Astrophysics Data System (ADS)

    Bagrov, V. G.; Gitman, D. M.; Levin, A.; Tlyachev, V. B.

    2001-07-01

    We study the impact of Aharonov-Bohm solenoid on the radiation of a charged particle moving in a constant uniform magnetic field. With this aim in view, exact solutions of Klein-Gordon and Dirac equations are found in the magnetic-solenoid field. Using such solutions, we calculate exactly all the characteristics of one-photon spontaneous radiation both for spinless and spinning particle. Considering non-relativistic and relativistic approximations, we analyze cyclotron and synchrotron radiations in detail. Radiation peculiarities caused by the presence of the solenoid may be considered as a manifestation of Aharonov-Bohm effect in the radiation. In particular, it is shown that new spectral lines appear in the radiation spectrum. Due to angular distribution peculiarities of the radiation intensity, these lines can in principle be isolated from basic cyclotron and synchrotron radiation spectra.

  18. Aharonov-Bohm Effect in Cyclotron and Synchrotron Radiations

    E-print Network

    V. G. Bagrov; D. M. Gitman; A. Levin; V. B. Tlyachev

    2000-11-06

    We study the impact of Aharonov-Bohm solenoid on the radiation of a charged particle moving in a constant uniform magnetic field. With this aim in view, exact solutions of Klein-Gordon and Dirac equations are found in the magnetic-solenoid field. Using such solutions, we calculate exactly all the characteristics of one-photon spontaneous radiation both for spinless and spinning particle. Considering non-relativistic and relativistic approximations, we analyze cyclotron and synchrotron radiations in detail. Radiation peculiarities caused by the presence of the solenoid may be considered as a manifestation of Aharonov-Bohm effect in the radiation. In particular, it is shown that new spectral lines appear in the radiation spectrum. Due to angular distribution peculiarities of the radiation intensity, these lines can in principle be isolated from basic cyclotron and synchrotron radiation spectra

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

    NASA Astrophysics Data System (ADS)

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

    1993-02-01

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

  20. Current performance of the self-extracting cyclotron

    SciTech Connect

    Lucas, S.; Swoboda, F.; Kleeven, W.; Delvaux, J.L.; Jongen, Y. [IBA Radio-Isotopes, Av de l'Esperance, 1, 6220 Fleurus (Belgium); IBA, Chemin du Cyclotron, B-1348 Louvain-La-Neuve (Belgium)

    2003-08-26

    The self-extracting cyclotron is a 14MeV multi-mA H+ machine from which the beam extracts without a deflector. The development of this prototype has started in 1998, and has now reached a point such that IBA considers to use it as a production machine. It is now installed in an irradiation facility and is equipped with two beam lines and two high power target-system. Beams of more than 1 mA have been extracted and transported to targets Further development is ongoing in order to increase the current on target to at least 2 mA in the coming months. Commercial isotope production will start at the end of this year. This paper will describe the current configuration of the cyclotron and the associated performances. Emphases will be put on reliability and associated problems, beam optics and performances of sub-systems.

  1. Ion-beam-driven electrostatic ion cyclotron instabilities

    SciTech Connect

    Miura, A.; Okuda, H.; Ashour-Abdalla, M.

    1982-10-01

    We present results of numerical simulations on the electrostatic ion cyclotron instabilities driven by the ion beam parallel to the magnetic field. For the beam speed exceeding the thermal speed of background ions and the beam temperature much lower than the background ion temperature, it is found that the instability results in strong perpendicular heating and slowing down of parallel drift of the beam ions, leading to the saturation of the instability. Applications to plasma heating and space plasma physics are discussed.

  2. Slant Slot Antenna-Type Electron Cyclotron Resonance Plasma Source

    Microsoft Academic Search

    Seiichi Watanabe; Hitoshi Tamura; Masahiro Sumiya; Muneo Furuse; Sunao Kawasaki

    1998-01-01

    A new compact electron cyclotron resonance (ECR) plasma source, which is termed slant-slot antenna-type ECR plasma source, is presented. Using this plasma source an ion saturation current density Iis of 6.2 mA\\/cm2±5.2% was obtained over a diameter of 300 mm under ambient conditions of Cl2 gas at 0.7 Pa. The features of the plasma source are an independent circular TM011

  3. Simulation of the current-driven electrostatic ion cyclotron instability

    Microsoft Academic Search

    P. I. Pritchett; J. M. Dawson

    1981-01-01

    Particle simulations are employed in a self-consistent investigation of the growth and saturation of current-driven instabilities along auroral field lines. Ion cyclotron waves are found to grow to levels ephi\\/T\\/sub e\\/approx.0.2--0.4, which are comparable with the levels observed by the S3-3 satellite. In the present initial-value calculations, saturation is due to plateau formation on the electron distribution function. Excitation of

  4. Two-dimensional simulation of an electron cyclotron resonance discharge

    Microsoft Academic Search

    J. H. Shiau; J. H. Tsai; S. H. Chen; J. Y. Yang; C. J. Chiou

    1999-01-01

    Summary form only given, as follows. A two-dimensional three-moment simulation code was developed and performed for the study of the electron cyclotron resonance (ECR) plasma sources based on the self-consistent fluid model which determines the dynamics of the plasma as well as its interactions with the microwave. In particular, the ECR discharges can be characterized by two major parameters, one

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

    NASA Technical Reports Server (NTRS)

    Alexander, S. G.; Meszaros, P.

    1989-01-01

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

  6. High-resolution kinetic simulations of electron cyclotron heating

    Microsoft Academic Search

    Vladimir Krivenski

    1999-01-01

    A parallel solver of the Fokker-Planck equation, coupled with a set of parallel interpretative codes (computing the Electron Cyclotron Emission, X-Ray Emission, and Thomson Scattering spectra for an arbitrary electron distribution function), was written. The code allows the computation of the electron distribution function at much higher resolution in phase-space than it was previously possible. We find this capability to

  7. CONTROL SYSTEM PROGRESS FOR K500 SUPERCONDUCTING CYCLOTRON

    Microsoft Academic Search

    S. Dasgupta

    2006-01-01

    Construction of the K500 Super-conducting cyclotron facility at VECC, Kolkata, has progressed to the extent that the building, the Magnet yoke, the Helium-plant, the super-conducting coil winding on bobbin, the trim coils are in their advanced stages of completion. Requirement analysis of the control system is under continued development, based on a document depicting detailed specifications of the sub-systems, prepared

  8. RF physics of ICWC discharge at high cyclotron harmonics

    SciTech Connect

    Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M. [Association Euratom-Belgian State, LPP-ERM-KMS, 1000 Brussels (Belgium); Bobkov, V.; Rohde, V.; Schneider, P. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching (Germany); Douai, D.; Kogut, D. [Association Euratom-CEA, CEA, IRFM, 13108 St Paul lez Durance (France); Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G. [Association Euratom-IEK-4, Forschungszentrum Jülich, 52425 Jülich (Germany); Moiseenko, V. [Institute of Plasma Physics NSC KIPT, 61108 Kharkiv (Ukraine); Noterdaeme, J.-M. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching, Germany and Ghent University, 9000 Ghent (Belgium); Collaboration: TEXTOR Team; ASDEX Upgrade Team

    2014-02-12

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

  9. Field Desorption Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    Microsoft Academic Search

    Tanner M. Schaub

    2004-01-01

    This, the 30th year of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS),1 has marked a milestone for incredible growth in the field of high-resolution mass spectrometry. The most notable realizations of this fact being the successful installation of the highest field FT-ICR MS system assembled to date (14.5 Tesla) and the recent release of the most advanced commercial

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

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

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

  11. Pencil Beam Scanning System Based On A Cyclotron

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

  12. 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 ...

  13. Medical Scientists

    MedlinePLUS

    ... little supervision, forming their own hypotheses and developing experiments, accordingly. They often lead teams of technicians, and ... prospective medical scientists the opportunity to develop their experiments and, sometimes, to supervise undergraduates. Ph.D. programs ...

  14. 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)

  15. Medical Assistants

    MedlinePLUS

    ... signs, such as heart rate and blood pressure. Training Medical assistants who do not have postsecondary education ... all workers was $34,750. On-the-job Training Additional training needed (postemployment) to attain competency in ...

  16. Backward mode of the ion-cyclotron wave in a semi-bounded magnetized Lorentzian plasma

    SciTech Connect

    Ki, Dae-Han [Department of Applied Physics, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Jung, Young-Dae [Department of Applied Physics, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180-3590 (United States)

    2012-08-15

    The backward modes of the surface ion-cyclotron wave are investigated in a semi-bounded magnetized Lorentzian plasma. The dispersion relation of the backward mode of the surface ion-cyclotron wave is obtained using the specular reflection boundary condition with the plasma dielectric function. The result shows that the nonthermal effect suppresses the wave frequency as well as the group velocity of the surface ion-cyclotron wave. It is also found that the nonthermal effect on the surface ion-cyclotron wave increases with an increase of the wave number. In addition, it is found that the propagation domain of the surface ion-cyclotron wave increases with an increase of the ratio of the electron plasma frequency to the electron gyrofrequency. It is also found that the nonthermal effect increases the propagation domain of the surface ion-cyclotron wave in a semi-bounded magnetized Lorentzian plasma.

  17. 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 ...

  18. Resonant Cyclotron Scattering and Comptonization in Neutron Star Magnetospheres

    E-print Network

    Maxim Lyutikov; Fotis P. Gavriil

    2006-02-10

    Resonant cyclotron scattering of the surface radiation in the magnetospheres of neutron stars may considerably modify the emergent spectra and impede efforts to constraint neutron star properties. Resonant cyclotron scattering by a non-relativistic warm plasma in an inhomogeneous magnetic field has a number of unusual characteristics: (i) in the limit of high resonant optical depth, the cyclotron resonant layer is half opaque, in sharp contrast to the case of non-resonant scattering. (ii) The transmitted flux is on average Compton up-scattered by ~ $1+ 2 beta_T$, where $\\beta_T$ is the typical thermal velocity in units of the velocity of light; the reflected flux has on average the initial frequency. (iii) For both the transmitted and reflected fluxes the dispersion of intensity decreases with increasing optical depth. (iv) The emergent spectrum is appreciably non-Plankian while narrow spectral features produced at the surface may be erased. We derive semi-analytically modification of the surface Plankian emission due to multiple scattering between the resonant layers and apply the model to anomalous X-ray pulsar 1E 1048.1--5937. Our simple model fits just as well as the ``canonical'' magnetar spectra model of a blackbody plus power-law.

  19. Apparent electrostatic ion cyclotron waves in the diffuse aurora

    SciTech Connect

    Bering, E.A.

    1983-08-01

    Emissions that have properties consistent with electrostatic ion cyclotron (EIC) waves have been observed at low altitude in the diffuse aurora by a sounding rocket payload. Peaks were observed in the power spectrum of the electric field near the hydrogen and oxygen ion cyclotron frequencies. Doppler shift and polarization analyses have been performed using EIC wave parameters derived from linear theory. Both analyses indicated that these emissions had properties consistent with those expected for H/sup +/ and O/sup +/ EIC waves. The two analyses indicated that both emission bands were due to waves propagating eastward parallel to the poleward boundary of the diffuse aurora. The large local cold plasma density and resulting Landau damping require that the source be local. Magnetometer data indicated the presence of a downward parallel current density of 5 ..mu..A/m/sup 2/. Sufficient free energy for the waves was available from this current, although the waves were observed frequently at altitudes where the ion-neutral collision frequency exceeded the oxygen cyclotron frequency.

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

    SciTech Connect

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

    1992-08-04

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

  1. Electron cyclotron heating on the ISX-B tokamak

    SciTech Connect

    Eldridge, O.C.; England, A.C.; Gilgenbach, R.M.; Hackett, K.F.; Kulchar, A.G.; Loring, C.M.; Wilgen, J.B.

    1980-01-01

    One experiment on electron cyclotron heating on the Impurity Study Experiment (ISX-b) tokamak has been completed and a second experiment is in progress. In the first experiment, with a gyrotron producing 100 kW at 35 GHz, a heating efficiency greater than 60% was achieved. Unpolarized radiation was launched from the high field side of the tokamak, heating electrons at cyclotron resonance in the center of the plasma. From laser scattering and thermal emission at the second gyroharmonic, the electron temperature, initially 850 eV, increased to 1250 eV at the end of a 15-ms pulse. The second experiment is now in progress, with 180 kW at 28 GHz and a capability of 100-ms pulses. A comparison between polarized and unpolarized radiation, modification of the plasma current profile, and a critical comparison with theory are planned. In this paper, experiments on preionization at the upper hybrid resonance are reported. A plasma with an electron temperature of 10 eV was produced, which is not high enough to reduce impurity radiation. The resistive part of the loop voltage was reduced by preionization. Plans for an experiment to measure electric current induced by electron cyclotron heating are presented, along with a review of the theoretical basis of the current drive.

  2. Kinetic simulation of the electron-cyclotron maser instability: effect of a finite source size

    NASA Astrophysics Data System (ADS)

    Kuznetsov, A. A.; Vlasov, V. G.

    2012-04-01

    The electron-cyclotron maser instability is widespread in the Universe, producing, e.g., radio emission of the magnetized planets and cool substellar objects. Diagnosing the parameters of astrophysical radio sources requires comprehensive nonlinear simulations of the radiation process taking into account the source geometry. In this work, we simulate the electron-cyclotron maser instability (i.e., the amplification of electromagnetic waves and the relaxation of an unstable electron distribution) in a very low-beta plasma. The model used takes into account the radiation escape from the source region and the particle flow through this region. We developed a kinetic quasi-linear code to simulate the time evolution of an electron distribution in a radio emission source. The model includes the terms describing the particle injection to and escape from the emission source region. The spatial escape of the emission from the source is taken into account by using a finite amplification time. The unstable electron distribution of the horseshoe type is considered. A number of simulations were performed for different parameter sets typical of the magnetospheres of planets and ultracool dwarfs. We have found that the generated emission (corresponding to the fundamental extraordinary mode) has a frequency close to the electron cyclotron frequency and propagates across the magnetic field. Shortly after the onset of a simulation, the electron distribution reaches a quasi-stationary state. Under the conditions typical of the sources of terrestrial and Saturnian auroral radio emissions, the dominant factor affecting the electron distribution is the particle escape from the emission source region. As a result, the electron distribution in a quasi-stationary state does not differ significantly from the horseshoe-like distribution of the injected electrons. The conversion efficiency of the particle energy flux into waves is typically a few percent. We have found good agreement of our model with the in situ observations in the source regions of auroral radio emissions of the Earth and Saturn. Under the conditions that seem to be typical of the magnetospheres of ultracool dwarfs, the electron distribution may become nearly flat due to the wave-particle interactions, while the conversion efficiency of the particle energy flux into waves reaches 10 - 20%. Therefore we expect the electron distributions in the stellar magnetospheres to look similar to Maxwellian or kappa distributions, which are only slightly distorted by the parallel electric field and magnetic mirroring. Nevertheless, even these small deviations from an equilibrium distribution seem to be sufficient to produce an intense radio emission.

  3. Development of a PET cyclotron based irradiation setup for proton radiobiology

    NASA Astrophysics Data System (ADS)

    Ghithan, Sharif; Crespo, Paulo; do Carmo, S. J. C.; Ferreira Marques, Rui; Fraga, F. A. F.; Simões, Hugo; Alves, Francisco; Rachinhas, P. J. B. M.

    2015-02-01

    An out-of-yoke irradiation setup using the proton beam from a cyclotron that ordinary produces radioisotopes for positron emission tomography (PET) has been developed, characterized, calibrated and validated. The current from a 20 ?m thick aluminum transmission foil is readout by home-made transimpedance electronics, providing online dose information. The main monitoring variables, delivered in real-time, include beam current, integrated charge and dose rate. Hence the dose and integrated current delivered at a given instant to an experimental setup can be computer-controlled with a shutter. In this work, we report on experimental results and Geant4 simulations of a setup which exploits for the first time the 18 MeV proton beam from a PET cyclotron to irradiate a selected region of a target using the developed irradiation system. By using this system, we are able to deliver a homogeneous beam on targets with 18 mm diameter, allowing to achieve the controlled irradiation of cell cultures located in biological multi-well dishes of 16 mm diameter. We found that the magnetic field applied inside the cyclotron plays a major role for achieving the referred to homogeneity. The quasi-Gaussian curve obtained by scanning the magnet current and measuring the corresponding dose rate must be measured before any irradiation procedure, with the shutter closed. At the optimum magnet current, which corresponds to the center of the Gaussian, a homogenous dose is observed over the whole target area. Making use of a rotating disk with a slit of 0.5 mm at a radius of 150 mm, we could measure dose rates on target ranging from 500 mGy/s down to 5 mGy/s. For validating the developed irradiation setup, several Gafchromic® EBT2 films were exposed to different values of dose. The absolute dose in the irradiated films were assessed in the 2D film dosimetry system of the Department of Radiotherapy of Coimbra University Hospital Center with a precision better than 2%. In the future, we plan to irradiate small animals, cell cultures, or other materials or samples.

  4. Theory of the current-driven ion cyclotron instability in the bottomside ionosphere

    Microsoft Academic Search

    P. Satyanarayana; P. K. Chaturvedi; M. J. Keskinen; J. D. Huba; S. L. Ossakow

    1985-01-01

    A theory of the current-driven electrostatic ion cyclotron(EIC) instability in the collisional bottomside ionosphere is presented. It is found that the electron collisions are destabilizing and are crucial for the excitation of the EIC instability in the collisional bottomside ionosphere. Furthermore, the growth rates of the ion cyclotron instability in the bottomside ionosphere maximize for (K-perpendicular) (rho sub i) or

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  6. Theory of the cyclotron resonance spectrum of a polaron in two dimensions

    Microsoft Academic Search

    Wu Xiaoguang; F. M. Peeters; J. T. Devreese

    1986-01-01

    The magneto-optical absorption spectrum of a two-dimensional polaron is calculated by using a memory-function approach. The cyclotron resonance frequency and the cyclotron resonance mass of the polaron are obtained for weak electron-phonon coupling. The absorption spectrum exhibits peaks around the cyclotron frequency omegac and the LO-phonon-assisted harmonics omegaLO+nomegac (n=1,2,. . .). The oscillator strength and the position of the peaks

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

    NASA Technical Reports Server (NTRS)

    Wu, C. S.

    1985-01-01

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

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

    E-print Network

    Knudson, Jon Sven

    1982-01-01

    . 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... observed the properties of elements and inferred their atomic structure. The development of particle accelerators, such as the cyclotron, allowed physi ci sts to observe the properties of atoms directly. Ernest Lawrence at his Radiation Laboratory...

  9. 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.

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

    PubMed

    Pal, Gautam; DuttaGupta, Anjan; Chakrabarti, Alok

    2014-07-01

    The beam chamber of Variable Energy Cyclotron Centre, Kolkata's K = 500 superconducting cyclotron is pumped by liquid helium cooled cryopanel with liquid nitrogen cooled radiation shield. Performance of the vacuum system was evaluated by cooling the cryopanel assembly with liquid nitrogen and liquid helium. Direct measurement of beam chamber pressure is quite difficult because of space restrictions and the presence of high magnetic field. Pressure gauges were placed away from the beam chamber. The beam chamber pressure was evaluated using a Monte Carlo simulation software for vacuum system and compared with measurements. The details of the vacuum system, measurements, and estimation of pressure of the beam chamber are described in this paper. PMID:25085128

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

    SciTech Connect

    Hojo, S., E-mail: s-hojo@nirs.go.jp; Katagiri, K.; Nakao, M.; Sugiura, A.; Muramatsu, M.; Noda, A.; Noda, K. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba (Japan)] [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba (Japan); Okada, T.; Takahashi, Y.; Komiyama, A.; Honma, T. [Accelerator Engineering Corporation, 6-18-1 Konakadai, Inage, Chiba (Japan)] [Accelerator Engineering Corporation, 6-18-1 Konakadai, Inage, Chiba (Japan)

    2014-02-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  13. MEDICAL EMERGENCIES What is a medical emergency?

    E-print Network

    Fernandez, Eduardo

    911 for emergency assistance · Following the arrangement of emergency medical treatment of Injury form. · assists the employee in selecting the appropriate medical provider. · arrangesMEDICAL EMERGENCIES What is a medical emergency? Serious injury or illness. What do I do

  14. 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.

  15. 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.

  16. 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)

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

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

    SciTech Connect

    Carbajal, L., E-mail: L.Carbajal-Gomez@warwick.ac.uk; Cook, J. W. S. [Centre for Fusion, Space and Astrophysics, Department of Physics, The University of Warwick, Coventry CV4 7AL (United Kingdom)] [Centre for Fusion, Space and Astrophysics, Department of Physics, The University of Warwick, Coventry CV4 7AL (United Kingdom); Dendy, R. O. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, Oxfordshire (United Kingdom) [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, Oxfordshire (United Kingdom); Centre for Fusion, Space and Astrophysics, Department of Physics, The University of Warwick, Coventry CV4 7AL (United Kingdom); Chapman, S. C. [Centre for Fusion, Space and Astrophysics, Department of Physics, The University of Warwick, Coventry CV4 7AL (United Kingdom) [Centre for Fusion, Space and Astrophysics, Department of Physics, The University of Warwick, Coventry CV4 7AL (United Kingdom); Department of Mathematics and Statistics, University of Tromsø, N-9037, Tromsø (Norway); Max Planck Institute for the Physics of Complex Systems, D-01187, Dresden (Germany)

    2014-01-15

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

  19. Low energy cyclotron production of multivalent transition metals for PET imaging and therapy

    NASA Astrophysics Data System (ADS)

    Avila-Rodriguez, Miguel Angel

    Recent advances in high-resolution tomographs for small animals require the production of nonconventional long-lived positron emitters to label novel radiopharmaceuticals for PET-based molecular imaging. Radioisotopes with an appropriate half life to match the kinetics of slow biological processes will allow to researchers to study the phamacokinetics of PET ligands over several hours, or even days, on the same animal, with the injection of a single dose. In addition, radionuclides with a suitable half life can potentially be distributed from a central production site making them available in PET facilities that lack an in-house cyclotron. In the last few years there has been a growing interest in the use of PET ligands labeled with radiometals, particularly isotopes of copper, yttrium and zirconium. Future clinical applications of these tracers will require them to be produced reliably and efficiently. This thesis work deals with implementing and optimizing the production of the multivalent transition metals 61,64Cu, 86Y and 89Zr for molecular PET imaging and therapy. Our findings in the production of these radionuclides at high specific activity on an 11 MeV proton-only cyclotron are presented. Local applications of these tracers, including Cu-ATSM for in vivo quantification of hypoxia, synthesis of targeted radiopharmaceuticals using activated esters of DOTA, and a novel development of positron emitting resin microspheres, are also be discussed. As a result of this thesis work, metallic radionuclides are now efficiently produced on a weekly basis in sufficient quality and quantity for collaborating scientists at UW-Madison and external users in other Universities across the country.

  20. Medical waste management in Korea.

    PubMed

    Jang, Yong-Chul; Lee, Cargro; Yoon, Oh-Sub; Kim, Hwidong

    2006-07-01

    The management of medical waste is of great importance due to its potential environmental hazards and public health risks. In the past medical waste was often mixed with municipal solid waste and disposed of in residential waste landfills or improper treatment facilities (e.g. inadequately controlled incinerators) in Korea. In recent years, many efforts have been made by environmental regulatory agencies and waste generators to better manage the waste from healthcare facilities. This paper presents an overview of the current management practices of medical waste in Korea. Information regarding generation, composition, segregation, transportation, and disposal of medical wastes is provided and discussed. Medical waste incineration is identified as the most preferred disposal method and will be the only available treatment option in late 2005. Faced with increased regulations over toxic air emissions (e.g. dioxins and furans), all existing small incineration facilities that do not have air pollution control devices will cease operation in the next few years. Large-scale medical waste incinerators would be responsible for the treatment of medical waste generated by most healthcare facilities in Korea. It is important to point out that there is a great potential to emit air toxic pollutants from such incinerators if improperly operated and managed, because medical waste typically contains a variety of plastic materials such as polyvinyl chloride (PVC). Waste minimization and recycling, control of toxic air emissions at medical waste incinerators, and alternative treatment methods to incineration are regarded to be the major challenges in the future. PMID:16338054

  1. Utilization of the CS-30 cyclotron at the Duke University Medical Center

    SciTech Connect

    Wieland, B.W.; McKinney, C.J.; Dailey, M.F. [Duke Univ., Durham, NC (United States)

    1994-12-31

    Present routine radionuclide production includes {sup 18}F fluoride from protons on {sup 18}O water, {sup 13}N ammonia from protons on {sup 13}C slurry, {sup 15}O water from deuterons on nitrogen gas, and {sup 211}At from alphas on bismuth metal. Clinical PET using two tomographs (GE 4096 and Advance) is done Tuesday through Friday, typically 4 to 11 patients per day using {sup 15}O water, {sup 13}N ammonia, and {sup 18}F FDG synthesized with a GE Microlab. Clinical patient studies are 50% neurology using FDG, 45% body using FDG, and 5% cardiology using ammonia and FDG (oncology in these three areas totals 60%). {sup 15}O water for clinical research patients (THC and cognitive) is produced twice a week. {sup 211}At is produced about twice a week for monoclonal antibody labelling.

  2. Medical Device Safety

    MedlinePLUS

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

  3. 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.

  4. Medical imaging

    SciTech Connect

    Jacobs, E.R.

    1987-01-01

    Medical Imaging: A Concise Textbook is written to assist a large group of medical personnel, including students and general practitioners, in reading radiographs. The book also attempts to give this group an introduction to radiology. The book begins by examining the physics and the positioning techniques of modern radiology. The following chapters then discuss the subspecialties, ranging from chest and musculoskeletal radiology to interventional radiology and nuclear medicine. The normal features of the subject are discussed first, followed by pathologic abnormalities. With the abnormal patterns, a differential diagnosis is arranged in tables.

  5. 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.

  6. Fast particle-driven ion cyclotron emission (ICE) in tokamak plasmas and the case for an ICE diagnostic in ITER

    NASA Astrophysics Data System (ADS)

    McClements, K. G.; D'Inca, R.; Dendy, R. O.; Carbajal, L.; Chapman, S. C.; Cook, J. W. S.; Harvey, R. W.; Heidbrink, W. W.; Pinches, S. D.

    2015-04-01

    The detection of fast particle-driven waves in the ion cyclotron frequency range (ion cyclotron emission or ICE) could provide a passive, non-invasive diagnostic of confined and escaping fast particles (fusion ?-particles and beam ions) in ITER, and would be compatible with the high radiation environment of deuterium–tritium plasmas in that device. Recent experimental results from ASDEX Upgrade and DIII-D demonstrate the efficacy of ICE as a diagnostic of different fast ion species and of fast ion losses, while recent particle-in-cell (PIC) and hybrid simulations provide a more exact comparison with measured ICE spectra and open the prospect of exploiting ICE more fully as a fast ion diagnostic in future experiments. In particular the PIC/hybrid approach should soon make it possible to simulate the nonlinear physics of ICE in full toroidal geometry. Emission has been observed previously at a wide range of poloidal angles, so there is flexibility in the location of ICE detectors. Such a detector could be implemented in ITER by installing a small toroidally orientated loop near the plasma edge or by adding a detection capability to the ion cyclotron resonance heating (ICRH) antennae. In the latter case, the antenna could be used simultaneously to heat the plasma and detect ICE, provided that frequencies close to those of the ICRH source are strongly attenuated in the detection system using a suitable filter. Wavenumber information, providing additional constraints on the fast ion distribution exciting the emission, could be obtained by measuring ICE using a toroidally distributed array of detectors or different straps of the ICRH antenna.

  7. Medical marijuana.

    PubMed

    Marmor, J B

    1998-06-01

    Although many clinical studies suggest the medical utility of marijuana for some conditions, the scientific evidence is weak. Many patients in California are self-medicating with marijuana, and physicians need data to assess the risks and benefits. The only reasonable solution to this problem is to encourage research on the medical effects of marijuana. The current regulatory system should be modified to remove barriers to clinical research with marijuana. The NIH panel has identified several conditions for which there may be therapeutic benefit from marijuana use and that merit further research. Marijuana should be held to the same evaluation standards of safety and efficacy as other drugs (a major flaw in Proposition 215) but should not have to be proved better than current medications for its use to be adopted. The therapeutic window for marijuana and THC between desired effect and unpleasant side effects is narrow and is a major reason for discontinuing use. Although the inhaled route of administration has the benefit of allowing patients to self-titrate the dose, the smoking of crude plant material is problematic. The NIH panel recommended that a high priority be given to the development of a controlled inhaled form of THC. The presence of a naturally occurring cannabinoid-receptor system in the brain suggests that research on selective analogues of THC may be useful to enhance its therapeutic effects and minimize adverse effects. PMID:9656007

  8. 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.

  9. Medical genetics

    SciTech Connect

    Nora, J.J.; Fraser, F.C.

    1989-01-01

    This book presents a discussion of medical genetics for the practitioner treating or counseling patients with genetic disease. It includes a discussion of the relationship of heredity and diseases, the chromosomal basis for heredity, gene frequencies, and genetics of development and maldevelopment. The authors also focus on teratology, somatic cell genetics, genetics and cancer, genetics of behavior.

  10. Electromagnetic Waves near the Proton Cyclotron Frequency: STEREO Observations

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  11. Glow plasma trigger for electron cyclotron resonance ion sourcesa)

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    Electron cyclotron resonance ion sources (ECRISs) are particularly useful for nuclear, atomic, and high energy physics, as unique high current generators of multicharged ion beams. Plasmas of gas discharges in an open magnetic trap heated by pulsed (100 ?s and longer) high power (100 kW and higher) high-frequency (greater than 37.5 GHz) microwaves of gyrotrons is promising in the field of research in the development of electron cyclotron resonance sources for high charge state ion beams. Reaching high ion charge states requires a decrease in gas pressure in the magnetic trap, but this method leads to increases in time, in which the microwave discharge develops. The gas breakdown and microwave discharge duration becomes greater than or equal to the microwave pulse duration when the pressure is decreased. This makes reaching the critical plasma density initiate an electron cyclotron resonance (ECR) discharge during pulse of microwave gyrotron radiation with gas pressure lower than a certain threshold. In order to reduce losses of microwave power, it is necessary to shorten the time of development of the ECR discharge. For fast triggering of ECR discharge under low pressure in an ECRIS, we initially propose to fill the magnetic trap with the plasmas of auxiliary pulsed discharges in crossed ExB fields. The glow plasma trigger of ECR based on a Penning or magnetron discharge has made it possible not only to fill the trap with plasma with density of 1012 cm-3, required for a rapid increase in plasma density and finally for ECR discharge ignition, but also to initially heat the plasma electrons to Te?20 eV.

  12. Glow plasma trigger for electron cyclotron resonance ion sources

    SciTech Connect

    Vodopianov, A. V.; Golubev, S. V.; Izotov, I. V. [Institute of Applied Physics, Russian Academy of Science, Nizhniy Novgorod 603950 (Russian Federation); Nikolaev, A. G.; Oks, E. M.; Savkin, K. P.; Yushkov, G. Yu. [High Current Electronics Institute, Siberian Division, Russian Academy of Science, Tomsk 634055 (Russian Federation)

    2010-02-15

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

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

    PubMed

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

    2010-02-01

    Electron cyclotron resonance ion sources (ECRISs) are particularly useful for nuclear, atomic, and high energy physics, as unique high current generators of multicharged ion beams. Plasmas of gas discharges in an open magnetic trap heated by pulsed (100 micros and longer) high power (100 kW and higher) high-frequency (greater than 37.5 GHz) microwaves of gyrotrons is promising in the field of research in the development of electron cyclotron resonance sources for high charge state ion beams. Reaching high ion charge states requires a decrease in gas pressure in the magnetic trap, but this method leads to increases in time, in which the microwave discharge develops. The gas breakdown and microwave discharge duration becomes greater than or equal to the microwave pulse duration when the pressure is decreased. This makes reaching the critical plasma density initiate an electron cyclotron resonance (ECR) discharge during pulse of microwave gyrotron radiation with gas pressure lower than a certain threshold. In order to reduce losses of microwave power, it is necessary to shorten the time of development of the ECR discharge. For fast triggering of ECR discharge under low pressure in an ECRIS, we initially propose to fill the magnetic trap with the plasmas of auxiliary pulsed discharges in crossed ExB fields. The glow plasma trigger of ECR based on a Penning or magnetron discharge has made it possible not only to fill the trap with plasma with density of 10(12) cm(-3), required for a rapid increase in plasma density and finally for ECR discharge ignition, but also to initially heat the plasma electrons to T(e) approximately = 20 eV. PMID:20192326

  14. SPIRAL FACILITY AT GANIL: ION BEAM SIMULATION AND OPTIMISATION METHOD FOR THE CIME CYCLOTRON INJECTION SYSTEM

    E-print Network

    Paris-Sud XI, Université de

    of the 3D electric fields and the beam dynamics in the cyclotron. This paper gives a descriptionJection elements, but in the absence of the RF cavities. 2.2 Electric fields: CHA3D, VINFLEC and PLTMG The axial injection in the CIME compact cyclotron uses either a Muller inflector [4] and RF cavity noses well suited

  15. Onset, growth, and saturation of the current-driven ion cyclotron instability

    Microsoft Academic Search

    D. L. Correll; N. Rynn

    1975-01-01

    The temporal evolution of the current-driven electrostatic ion cyclotron instability was investigated experimentally. The critical destabilizing electron drift velocity for different values of mode phase velocity was measured. The phase velocity was changed by varying the effective plasma column length and hence the parallel wavelength. Ion cyclotron damping was observed to dominate over electron Landau damping at low phase velocities.

  16. Effects on Ion Cyclotron Emission of the Orbit Topology Changes from the Wave-Particle Interactions

    Microsoft Academic Search

    T. Hellsten; K. Holmström; T. Johnson; T. Bergkvist; M. Laxåback

    It is known that non-relaxed distribution functions can give rise to excitation of magnetosonic waves by ion cyclotron interactions when the distribution function increases with respect to the perpendicular velocity. We have found that in a toroidal plasma also collisional relaxed distribution functions of central peaked high-energy ions can destabilise magnetosonic eigenmodes by ion cyclotron interactions, due to the change

  17. The Upgrade Project at Texas A and M University Cyclotron Institute: Update

    SciTech Connect

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

    2010-11-24

    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.

  18. A note on electrostatic ion\\/dust cyclotron instabilities in dusty plasmas

    Microsoft Academic Search

    V. W. Chow; M. Rosenberg

    1998-01-01

    The electrostatic dust cyclotron instability (EDC) in dusty plasmas is somewhat analogous to the electrostatic ion cyclotron instability (EIC) in electron-ion plasmas, negative ion plasmas, and dusty plasmas. While the EIC instability can be driven by an electron drift along the magnetic field, the EDC instability can be driven by an ion drift along B in a plasma with negatively

  19. Normal and anomalous Doppler effects in a dielectric-loaded stripline cyclotron-resonance maser oscillator

    E-print Network

    Jerby, Eli

    Normal and anomalous Doppler effects in a dielectric-loaded stripline cyclotron-resonance maser-651X 97 09010-7 PACS number s : 41.60. m, 84.40.Ik I. INTRODUCTION The cyclotron-resonance maser CRM autoresonance maser CARM experiment 7 . Periodic waveguides made of arrays of metal posts were used

  20. Theory of electron cyclotron maser interaction in a cavity at the harmonic frequencies

    Microsoft Academic Search

    K. R. Chu

    1978-01-01

    A theory of the cyclotron maser interaction between an annular electron beam and the standing electromagnetic wave in a cavity structure is formulated on the basis of the relativistic Vlasov equation and the Maxwell equations. Detailed analytical expressions for the beam-wave coupling coefficient, beam energy gain, and threshold beam power have been derived for the fundamental and higher cyclotron harmonics.

  1. Experimental and theoretical studies of a 35 GHz cyclotron autoresonance maser amplifier

    E-print Network

    Wurtele, Jonathan

    Experimental and theoretical studies of a 35 GHz cyclotron autoresonance maser amplifier A. C. Di maser (CARM) amplifier are reported. The measurements are carried out at a frequency of 35 GHz using agreement with the experimental observations. I. INTRODUCTION The cyclotron autoresonance maser (CARM) has

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

    SciTech Connect

    Savilov, A. V. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation) and Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod (Russian Federation)

    2012-11-01

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

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

    Microsoft Academic Search

    Andrey Bosko

    2005-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  5. Nonlinear dynamics of the electromagnetic ion cyclotron structures in the inner magnetosphere

    Microsoft Academic Search

    N. L. Tsintsadze; T. D. Kaladze; J. W. Van Dam; W. Horton; X. R. Fu; T. W. Garner

    2010-01-01

    Electromagnetic ion cyclotron waves, called EMICs, are widely observed in the inner magnetosphere and can be excited through various plasma mechanisms such as ion temperature anisotropy. These waves interact with magnetospheric particles, which they can scatter into the loss cone. This paper investigates how nonlinearities in the ion fluid equations governing the electromagnetic ion cyclotron waves cause large-amplitude EMIC waves

  6. Major results of the electron cyclotron heating experiment in the PDX tokamak

    Microsoft Academic Search

    H. Hsuan; K. Bol; N. Bowen; D. Boyd; A. Cavallo; A. Dimits; J. Doane; G. Elder; M. Goldman; B. Grek

    1984-01-01

    Electron Cyclotron Heating (ECH) experiments on PDX have been carried out with two 60 GHz pulsed gyrotrons each yielding up to approximately 100 kW. The ECH system used two waveguide runs each about 30 meters long. One run included 5 bends and the other, 7 bends. Predetermined waveguide modes were transmitted. The electron cyclotron waves were launched in narrow beams

  7. Interaction of Neutral Beam (NB) Injected Fast Ions With Ion Cyclotron Resonance Frequency (ICRF) Waves

    Microsoft Academic Search

    M. Choi; V. S. Chan; S. C. Chiu; Y. A. Omelchenko; Y. Sentoku; H. E. St. John

    2003-01-01

    Existing tokamaks such as DIII-D and future experiments like ITER employ both NB injection (NBI) and ion-cyclotron resonance heating (ICRH) for auxiliary heating and current drive. The presence of energetic particles produced by NBI can result in absorption of the Ion cyclotron radio frequency (ICRF) power. ICRF can also interact with the energetic beam ions to alter the characteristics of

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

    NASA Technical Reports Server (NTRS)

    Marzoli, Irene; Tombesi, Paolo

    1993-01-01

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

  9. Design Characteristics of the K=800 Superconducting Cyclotron at M.S.U

    Microsoft Academic Search

    F. Resmini; G. Bellomo; E. Fabrici; H. G. Blosser; D. Johnson

    1979-01-01

    Design work on the proposed K=800, KF= 400, superconducting cyclotron at MSU has progressed to the point where overall machine characteristics are firmly established. The main purpose1 of the machine is to serve as a booster for the K=500 cyclotron, now under construction. In this respect, let us recall that the design goal is to achieve maximum beam energies of

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

    SciTech Connect

    Alexander, S.G.; Meszaros, P. (Pennsylvania State Univ., University Park (USA))

    1989-09-01

    A transmission model of gamma-ray burst sources is studied using the relativistic QED magnetic-resonant opacities including multiple photon scattering, incorporated into a discrete-ordinate radiative-transport scheme. The physics of the cyclotron line-producing region is discussed in general, and the expected line profiles, relative harmonic strengths, and polarizations are indicated under various conditions. The calculated spectra for these models show good agreement with the spectra reported from Ginga for GB 880205 and GB 870303. 22 refs.

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

    SciTech Connect

    Kurayev, A.A.; Lukashonok, D.V.; Sinitsyn, A.K., E-mail: kurayev@bsuir.by, E-mail: timka86@gmail.com [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus)

    2011-07-01

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

  12. Experimental monitoring of ozone production in a PET cyclotron facility.

    PubMed

    Zanibellato, L; Cicoria, G; Pancaldi, D; Boschi, S; Mostacci, D; Marengo, M

    2010-10-01

    Ozone produced from radiolytic processes was investigated as a possible health hazard in the working environment at the University Hospital "S.Orsola--Malpighi" PET facility. Intense radiation fields can generate ozone, known to be the most toxic gas produced by ionizing radiation around a particle accelerator. To evaluate ozone concentration in air, two different measurement campaigns were conducted with passive diffusion detectors. Comparison of the results with the concentration limits recommended by American Conference of Governmental Industrial Hygienists (ACGIH) demonstrated that ozone poses no health hazard to workers around a biomedical cyclotron. PMID:20483623

  13. Electron cyclotron resonance microwave ion sources for thin film processing

    SciTech Connect

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

    1990-01-01

    Plasmas created by microwave absorption at the electron cyclotron resonance (ECR) are increasingly used for a variety of plasma processes, including both etching and deposition. ECR sources efficiently couple energy to electrons and use magnetic confinement to maximize the probability of an electron creating an ion or free radical in pressure regimes where the mean free path for ionization is comparable to the ECR source dimensions. The general operating principles of ECR sources are discussed with special emphasis on their use for thin film etching. Data on source performance during Cl base etching of Si using an ECR system are presented. 32 refs., 5 figs.

  14. Plasma modeling in an electron-cyclotron-resonance ion source

    SciTech Connect

    Pesic, S.; Vukovic, M. (Institute for Research in Physics, Boris Kidric'' Institute, P.O. Box 522, 11001 Beograd (Yugoslavia))

    1990-09-15

    Modeling calculations of an electron-cyclotron-resonance ion source (ECRIS) are presented. The adopted model is described through an analysis of the impact of ECR heating, transport, and atomic-collision processes on the particle balance in an ECRIS. On the basis of the obtained numerical results, general relationships among externally controllable parameters, and plasma and ion-beam characteristics are derived. Comparison with experimental results that use the electron energy as the only fitting parameter supports the applied model. The predicted general trends provide some basis for future experiments.

  15. Two aspects of the K500 cyclotron project 

    E-print Network

    Van Baalen, Aaron Chase

    1988-01-01

    cyclotron magnet vas designed to produce magnetic fields that vill allow isochronous acceleration (see Appendix A) of ions vith a charge-to-mass ratio in the zange of 0. 01 to 0. 5 to final energies of betveen 0. 1 and 80 NeV/n (see Fig. 1) [7... (- "5 mV) of the circuitry. Since the field varies by + 8 kG relative to the central field, the measurement of the field difference vill be accurate to approximately z 1 gauss [8). A mechanical system (see Fig. 6) vas constructed to map the field...

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

    PubMed

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

    2005-03-01

    The feasibility of producing Ac-225 by proton irradiation of Ra-226 in a cyclotron through the reaction Ra-226(p,2n)Ac-225 has been experimentally demonstrated for the first time. Proton energies were varied from 8.8 to 24.8 MeV and cross-sections were determined by radiochemical analysis of reaction yields. Maximum yields were reached at incident proton energies of 16.8 MeV. Radiochemical separation of Ac-225 from the irradiated target yielded a product suitable for targeted alpha therapy of cancer. PMID:15607913

  17. Deposition of diamondlike films by electron cyclotron resonance microwave plasmas

    NASA Technical Reports Server (NTRS)

    Pool, F. S.; Shing, Y. H.

    1990-01-01

    Hard a-C:H films have been deposited through electron cyclotron resonance (ECR) microwave plasma decomposition of CH4 diluted with H2 gas. It has been found that hard diamondlike films could only be produced under a RF-induced negative self-bias of the substrate stage. Raman spectra indicate the deposition of two distinct film types: one film type exhibiting well-defined bands at 1360 and 1580/cm and another displaying a broad Raman peak centered at approximately 1500/cm. Variation of the mirror magnetic-field profile of the ECR system was examined, demonstrating the manipulation of film morphology through the extraction of different ion energies.

  18. Generating electron cyclotron resonance plasma using distributed scheme

    SciTech Connect

    Huang, C. C. [Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan (China); Chung-Shan Institute of Science and Technology, Lung-Tan, Taoyuan, Taiwan (China); Chang, T. H.; Chen, N. C.; Chao, H. W. [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China); Chen, C. C. [Chung-Shan Institute of Science and Technology, Lung-Tan, Taoyuan, Taiwan (China); Chou, S. F. [Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan (China)

    2012-08-06

    This study employs a distributed microwave input system and permanent magnets to generate large-area electron cyclotron resonance (ECR) plasma. ECR plasmas were generated with nitrogen gas, and the plasma density was measured by Langmuir probe. A uniform ECR plasma with the electron density fluctuation of {+-}9.8% over 500 mm Multiplication-Sign 500 mm was reported. The proposed idea of generating uniform ECR plasma can be scaled to a much larger area by using n Multiplication-Sign n microwave input array system together with well-designed permanent magnets.

  19. Electromagnetic ion/ion cyclotron instability at slow shocks

    NASA Technical Reports Server (NTRS)

    Winske, D.; Omidi, N.

    1990-01-01

    The linear and nonlinear properties of the obliquely propagating electromagnetic ion/ion cyclotron instability are investigated. The instability is driven by the relative, field-aligned streaming of two ion beams and can exist at a lower velocity threshold than the more commonly studied, parallel propagating electromagnetic ion beam instabilities. It is shown that the instability plays an important role in the formation of, dissipation at, and waves upstream of slow mode shocks. Possible application of this instability to ion beams in the plasma sheet boundary layer is also briefly discussed.

  20. Experimental demonstration of high efficiency electron cyclotron autoresonance acceleration

    SciTech Connect

    LaPointe, M.A.; Yoder, R.B.; Wang, C.; Ganguly, A.K.; Hirshfield, J.L. [Omega-P, Inc., 202008 Yale Station, New Haven, Connecticut 06520 (United States)] [Omega-P, Inc., 202008 Yale Station, New Haven, Connecticut 06520 (United States); [Physics Department, Yale University, New Haven, Connecticut 06520-8120 (United States)

    1996-04-01

    First experimental results are reported on the operation of a multimegawatt 2.856 GHz cyclotron autoresonance accelerator (CARA). A 90{endash}100 kV, 2{endash}3 MW linear electron beam has had up to6.6 MW added to it in CARA, with an rf-to-beam power efficiency of up to 96{percent}. This efficiency level is larger than that reported for any fast-wave interaction between radiation and electrons, and also larger than that in normal conducting rf linear accelerators. The results obtained are in good agreement with theoretical predictions. {copyright} {ital 1996 The American Physical Society.}

  1. Study of selective heating at ion cyclotron resonance

    SciTech Connect

    Compant La Fontaine, A. [DCC/DPE/SPEA, CEA C.E. Saclay 91191 Gif Sur Yvette Cedex (France)

    1996-02-01

    In order to achieve effective isotopic separation by the Plasma Separation Process (PSP) near the ion cyclotron resonance, experiments are performed on the ERIC device,{sup 1,2} and in parallel theory is developed. Some recent results dealing with the basic properties of the electromagnetic wave induced in the plasma are presented. Also the conditions for which the heating is the most selective are given. In addition experimental measurements of ionic temperatures of resonant isotopes are compared with theoretical results. {copyright} {ital 1996 American Institute of Physics.}

  2. Cyclotron line resonant transfer through neutron star atmospheres

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    Monte Carlo methods are used to study in detail the resonant radiative transfer of cyclotron line photons with recoil through a purely scattering neutron star atmosphere for both the polarized and unpolarized cases. For each case, the number of scatters, the path length traveled, the escape frequency shift, the escape direction cosine, the emergent frequency spectra, and the angular distribution of escaping photons are investigated. In the polarized case, transfer is calculated using both the cold plasma e- and o-modes and the magnetic vacuum perpendicular and parallel modes.

  3. Initiative in Nuclear Theory at the Variable Energy Cyclotron Centre

    E-print Network

    D. K. Srivastava; J. Alam; D. N. Basu; A. K. Chaudhuri; J. N. De; K. Krishan; S. Pal

    2005-06-24

    We recall the path breaking contributions of the nuclear theory group of the Variable Energy Cyclotron Centre, Kolkata. From a beginning of just one person in 1970s, the group has steadily developed into a leading group in the country today, with seminal contributions to almost the entire range of nuclear physics, viz., low energy nuclear reactions, nuclear structure, deep inelastic collisions, fission, liquid to gas phase transitions, nuclear matter, equation of state, mass formulae, neutron stars, relativistic heavy ion collisions, medium modification of hadron properties, quark gluon plasma, and cosmology of early universe.

  4. Beam injection improvement for electron cyclotron resonance charge breeders

    SciTech Connect

    Lamy, T.; Angot, J.; Sortais, P.; Thuillier, T. [Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, Grenoble (France); Galata, A. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy)

    2012-02-15

    The injection of a 1+ beam into an electron cyclotron resonance (ECR) charge breeder is classically performed through a grounded tube placed on its axis at the injection side. This tube presents various disadvantages for the operation of an ECR charge breeder. First experiments without a grounded tube show a better use of the microwave power and a better charge breeding efficiency. The optical acceptance of the charge breeder without decelerating tube allows the injection of high intensity 1+ ion beams at high energy, allowing metals sputtering inside the ion source. The use of this method for refractory metallic ion beams production is evaluated.

  5. Theory of the anomalous Doppler cyclotron-resonance-maser amplifier with tapered parameters G. S. Nusinovich,1

    E-print Network

    Jerby, Eli

    Theory of the anomalous Doppler cyclotron-resonance-maser amplifier with tapered parameters G. S The theory of a slow-wave cyclotron-resonance-maser CRM amplifier employing an initially linear elec- tron Cyclotron resonance masers CRM's are sources of co- herent electromagnetic EM radiation based on the cyclo

  6. How do we Define a Medical School?

    PubMed Central

    Karle, Hans

    2010-01-01

    A century after the Flexner Report on medical education in North America, which revolutionised the training of medical doctors all over the world, it is time to revisit this famous document and analyse symptoms and signs of a return to pre-Flexnerian conditions. With the ongoing mushroom growth over the last decades of small, proprietary educational institutions of low quality and driven by for-profit purposes, medical education is in a threatened position. This trend is of general international interest because of the increasing migration of medical doctors. There is a need for discussion of what should be the rational criteria and basic requirements for establishing new medical schools. PMID:21509225

  7. Medical imaging

    NASA Astrophysics Data System (ADS)

    Elliott, Alex

    2005-07-01

    Diagnostic medical imaging is a fundamental part of the practice of modern medicine and is responsible for the expenditure of considerable amounts of capital and revenue monies in healthcare systems around the world. Much research and development work is carried out, both by commercial companies and the academic community. This paper reviews briefly each of the major diagnostic medical imaging techniques—X-ray (planar and CT), ultrasound, nuclear medicine (planar, SPECT and PET) and magnetic resonance. The technical challenges facing each are highlighted, with some of the most recent developments. In terms of the future, interventional/peri-operative imaging, the advancement of molecular medicine and gene therapy are identified as potential areas of expansion.

  8. Medical Dictionary

    NSDL National Science Digital Library

    For nurses and other health care professionals who seek to distinguish the habitus from the humerus, this online medical dictionary provided by MedicineNet will be a place to bookmark for repeat visits. The dictionary contains well-written explanations for over 16,000 medical terms, and users can go ahead and browse around, or enter keywords or phrases into the search engine that resides on the page. The site also features a â??Word of the Dayâ?, and visitors can also look through recent news items that address different health issues and also look over the latest entries to the dictionary. The site is rounded out by a list of the â??Top 10 Medtermsâ?, which is also a good way to start exploring the materials here.

  9. Compact antenna for two-dimensional beam scan in the JT-60U electron cyclotron heating/current drive system

    SciTech Connect

    Moriyama, S.; Kajiwara, K.; Takahashi, K.; Kasugai, A.; Seki, M.; Ikeda, Y.; Fujii, T. [Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Mukoyama 801-1, Naka-shi, Ibaraki 311-0193 (Japan)

    2005-11-15

    A compact antenna system was designed and fabricated to enable millimeter-wave beam scanning in the toroidal and poloidal directions of the JT-60U tokamak for electron cyclotron heating (ECH) and electron cyclotron current drive (ECCD) experiments. The antenna consists of a fast movable flat mirror mounted on the tokamak vacuum vessel and a rotary focusing mirror attached at the end of the waveguide that is supported from outside the vacuum vessel. This separate support concept enables a compact structure inside a shallow port (0.68x0.54x0.2 m) that is shared with a subport for an independent diagnostic system. During a plasma shot, the flat mirror is driven by a servomotor with a 3-m-long drive shaft to reduce the influence of the high magnetic field on the motor. The focusing mirror is rotated by a simple mechanism utilizing a push rod and an air cylinder. The antenna has been operated reliably for 3 years after a small improvement to the rotary drive mechanism. It has made significant contributions to ECH and ECCD experiments, especially the current profile control in JT-60U.

  10. Plasma-sheath instability in Hall thrusters due to periodic modulation of the energy of secondary electrons in cyclotron motion

    SciTech Connect

    Sydorenko, D.; Smolyakov, A. [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Kaganovich, I.; Raitses, Y. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

    2008-05-15

    Particle-in-cell simulation of Hall thruster plasmas reveals a plasma-sheath instability manifesting itself as a rearrangement of the plasma sheath near the thruster channel walls accompanied by a sudden change of many discharge parameters. The instability develops when the sheath current as a function of the sheath voltage is in the negative conductivity regime. The major part of the sheath current is produced by beams of secondary electrons counter-streaming between the walls. The negative conductivity is the result of nonlinear dependence of beam-induced secondary electron emission on the plasma potential. The intensity of such emission is defined by the beam energy. The energy of the beam in crossed axial electric and radial magnetic fields is a quasiperiodical function of the phase of cyclotron rotation, which depends on the radial profile of the potential and the thruster channel width. There is a discrete set of stability intervals determined by the final phase of the cyclotron rotation of secondary electrons. As a result, a small variation of the thruster channel width may result in abrupt changes of plasma parameters if the plasma state jumps from one stability interval to another.

  11. Medication Considerations

    Microsoft Academic Search

    Colleen E. Carney; Jack D. Edinger

    \\u000a Despite the general efficacy of CBT for insomnia, this form of therapy is generally not the first intervention chosen for\\u000a the majority of treatment seeking insomnia sufferers. Most are seen in primary care settings where they usually are treated\\u000a with some form of hypnotic medication. Many of those who eventually present for a trial of CBT do so while continuing

  12. Medical Telemetry

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Telemetry is the process whereby physiological or other data is acquired by instruments, translated into radio signals and j sent to a receiving station where the signals are decoded and recorded. Extensively used in I space operations, it is finding new Earth applications, among them transmission of medical data between emergency vehicles and hospitals. For example, transmission of an electrocardiogram from an ambulance to a hospital enables a physician to read the telemetered EKG and advise ambulance attendants on emergency procedures. Central Medical Emergency Dispatch (CMED) operates as a regional emergency medical communications center for Cleveland, Ohio and Cuyahoga County. The CMED system includes radio and telephone communications from hospital-to-hospital and from ambulance-to-hospital, but for improved emergency life support CMED sought to add a county-wide telemetry capability. The problem was that there were only eight radio frequencies available for telemetry and there were more than 30 potential users in Cleveland alone. NASA's Lewis Research Center volunteered its expert assistance. The Center's engineers studied the systems of other telemetry using cities, surveyed area hospitals to assure compatibility of telemetry equipment, and advised what types of equipment would be needed in emergency vehicles and at the various hospitals. The Lewis plan suggested that CMED be designated the central coordinating agency for the Cuyahoga County system, monitoring all telemetry frequencies and, when requested, assigning one not in use or one to be used at a sufficient distance that it would create no interference problem.

  13. SUPERCONDUCTING RING CYCLOTRON FOR RIKEN RI BEAM FACTORY IN JAPAN

    SciTech Connect

    Okuno, H.; Dantsuka, T.; Yamada, K.; Kase, M.; Maie, T.; Kamigaito, O. [RIKEN Nishina Center, Wako, Saitama, 351-0198 (Japan)

    2010-04-09

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

  14. Electron Cyclotron Heating at 0.5 T in HSX*

    NASA Astrophysics Data System (ADS)

    Talmadge, J. N.; Almagri, A.; Anderson, D. T.; Anderson, F. S. B.; Gerhardt, S. P.; Sakaguchi, V.; Shafii, J.; Vernon, R. J.; Bigelow, T. S.; Likin, K. M.

    1999-11-01

    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. An estimate of the power deposition profile has been made based on ray-tracing calculations. Modeling of the neoclassical electron thermal conductivity profile has been improved by taking into account the finite coil magnetic field spectrum and the ambipolar calculation of the electric field. The 1-D transport code ASTRA[1] is used to calculate the electron temperature profiles for both the quasi-helical mode of operation, and for a configuration which simulates transport in a conventional stellarator. Electron temperature profiles will be measured in collaboration with UC-Davis using a multiple frequency, single spatial channel electron cyclotron emission radiometer operated at the second harmonic. First plasma results using the 28 GHz gyrotron will be presented, if available. [1] N. E. Karulin, IPP 3/328, 1994. *Work supported by USDOE grant DE-FG02-93ER54222.

  15. Electronuclear ion fusion in an ion cyclotron resonance reactor

    SciTech Connect

    Cowgill, Donald F.

    1996-12-01

    A method and apparatus for generating nuclear fusion by ion cyclotron resonance in an ion trap reactor. The reactor includes a cylindrical housing having an axial axis, an internal surface, and first and second ends. First and second end plates that are charged are respectively located at the first and second ends of the cylindrical housing. A gas layer is adsorbed on the internal surface of the cylindrical housing. Ions are desorbed from the gas layer, forming a plasma layer adjacent to the cylindrical housing that includes first ions that have a same charge sign as the first and second end plates. A uniform magnetic field is oriented along the axial axis of the cylindrical housing. Second ions, that are unlike the first ions, but have the same charge sign, are injected into the cylindrical housing along the axial axis of the cylindrical housing. A radio frequency field resonantly accelerates the injected second ions at the cyclotron resonance frequency of the second ions. The second ions circulate in increasing helical orbits and react with the first ions, at the optimum energy for nuclear fusion. The amplitude of the radio frequency field is adjusted to accelerate the second ions at a rate equal to the rate of tangential energy loss of the second ions by nuclear scattering in the first ions, causing the ions to continually interact until fusion occurs.

  16. Electron cyclotron emission measurements on the Texas Experimental Tokamak

    SciTech Connect

    Austin, M.E. Jr.

    1992-01-01

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

  17. Electron cyclotron maser emission from solar coronal funnels?

    NASA Astrophysics Data System (ADS)

    Vocks, C.; Mann, G.

    2004-05-01

    The sun is covered by a network of supergranular cells. The convective motion of these cells leads to the formation of strong magnetic fields at the cell boundaries. At larger heights in the solar transition region and low corona, this magnetic field geometry expands rapidly within a short distance, and forms the magnetic structure of ``coronal funnels''. This field line geometry represents a magnetic mirror, and since the plasma density strongly increases with depth in the transition region, the electron velocity distribution function (VDF) can develop a loss cone. Within such a coronal funnel, the plasma frequency can have smaller values than the electron cyclotron frequency, ?p < ?e. These are the necessary conditions for the generation of X-mode waves through the electron cyclotron maser mechanism. Since there is some observational evidence for radio emission from the supergranular network, it is of interest to investigate the possibility of this plasma wave generation in a quiet stellar atmosphere in detail. In this paper, a kinetic model is used to calculate the electron VDF in a coronal funnel. A method is derived to determine wave growth rates from the electron VDF. Its application on the coronal funnel VDF indeed results in X-mode wave growth. However, it is also found that wave absorption by higher-order resonances at larger heights in the atmosphere plays an important role.

  18. A Suzaku View of Cyclotron Line Sources and Candidates

    E-print Network

    Pottschmidt, K; Rivers, E; Rothschild, R E; Marcu, D M; Barragán, L; Kühnel, M; Fürst, F; Schwarm, F; Kreykenbohm, I; Wilms, J; Schönherr, G; Caballero, I; Camero-Arranz, A; Bodaghee, A; Doroshenko, V; Klochkov, D; Santangelo, A; Staubert, R; Kretschmar, P; Wilson-Hodge, C; Finger, M H; Terada, Y

    2011-01-01

    Seventeen accreting neutron star pulsars, mostly high mass X-ray binaries with half of them Be-type transients, are known to exhibit Cyclotron Resonance Scattering Features (CRSFs) in their X-ray spectra, with characteristic line energies from 10 to 60 keV. To date about two thirds of them, plus a few similar systems without known CRSFs, have been observed with Suzaku. We present an overview of results from these observations, including the discovery of a CRSF in the transient 1A 1118-61 and pulse phase resolved spectroscopy of GX 301-2. These observations allow for the determination of cyclotron line parameters to an unprecedented degree of accuracy within a moderate amount of observing time. This is important since these parameters vary - e.g., with orbital phase, pulse phase, or luminosity - depending on the geometry of the magnetic field of the pulsar and the properties of the accretion column at the magnetic poles. We briefly introduce a spectral model for CRSFs that is currently being developed and that...

  19. Medical errors in neurosurgery

    PubMed Central

    Rolston, John D.; Zygourakis, Corinna C.; Han, Seunggu J.; Lau, Catherine Y.; Berger, Mitchel S.; Parsa, Andrew T.

    2014-01-01

    Background: Medical errors cause nearly 100,000 deaths per year and cost billions of dollars annually. In order to rationally develop and institute programs to mitigate errors, the relative frequency and costs of different errors must be documented. This analysis will permit the judicious allocation of scarce healthcare resources to address the most costly errors as they are identified. Methods: Here, we provide a systematic review of the neurosurgical literature describing medical errors at the departmental level. Eligible articles were identified from the PubMed database, and restricted to reports of recognizable errors across neurosurgical practices. We limited this analysis to cross-sectional studies of errors in order to better match systems-level concerns, rather than reviewing the literature for individually selected errors like wrong-sided or wrong-level surgery. Results: Only a small number of articles met these criteria, highlighting the paucity of data on this topic. From these studies, errors were documented in anywhere from 12% to 88.7% of cases. These errors had many sources, of which only 23.7-27.8% were technical, related to the execution of the surgery itself, highlighting the importance of systems-level approaches to protecting patients and reducing errors. Conclusions: Overall, the magnitude of medical errors in neurosurgery and the lack of focused research emphasize the need for prospective categorization of morbidity with judicious attribution. Ultimately, we must raise awareness of the impact of medical errors in neurosurgery, reduce the occurrence of medical errors, and mitigate their detrimental effects. PMID:25371849

  20. Medical alert bracelet (image)

    MedlinePLUS

    People with diabetes should always wear a medical alert bracelet or necklace that emergency medical workers will ... People with diabetes should always wear a medical alert bracelet or necklace that emergency medical workers will ...

  1. Implantable Medical Devices

    MedlinePLUS

    Implantable Medical Devices Updated:Oct 23,2014 Implantable Medical Devices - 2 types 1. Rhythm control ICD -- Implantable cardioverter-defibrillator ( ... medical treatment. 2. Support of the Circulation Implantable Medical Devices Left Ventricular Assist Device (Also known as ...

  2. Recent Medical Device Recalls

    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 Recalls List ...

  3. Services Bldg. Veterinary Medical

    E-print Network

    Lin, Zhiqun

    Student Services Bldg. Oak Veterinary Medical College Veterinary Medical Research Institute Stadium Continuing Education--H7 Veterinary Medical College--I13 Veterinary Medical Research Institute-- H13

  4. 77 FR 31143 - Emergency Medical Services Week, 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-24

    ...Proclamation 8824--Emergency Medical Services Week, 2012 Proclamation 8825--National Safe Boating Week, 2012 Proclamation 8826--National Small Business Week, 2012 Proclamation 8827--World Trade Week, 2012...

  5. Precision assembly systems for medical devices

    Microsoft Academic Search

    Christine Connolly

    2009-01-01

    Purpose – The purpose of this paper is to describe the approach and technology of various companies making automated assembly equipment for medical devices. Design\\/methodology\\/approach – The structure of the medical device assembly market is introduced, and the expertise and applications of a small company working in the intermediate production market is described. The modular approach of Mikron Assembly Technology

  6. Medical Mysteries

    NSDL National Science Digital Library

    Rice University presents Medical Mysteries (or MedMyst for short) "an Internet-based adventure...in which you are on a mission to discover the causes of diseases." Designed for middle and high school students, MedMyst offers an engaging, multimedia approach to learning about infectious diseases and the immune system, as well as pharmacology, chemistry, public health policy, and more. MedMyst also includes three downloadable mini-labs that expand on concepts covered in the multimedia adventure. The Web site also includes loads of useful links.

  7. Medical Mystery

    NSDL National Science Digital Library

    2014-01-28

    This activity (on pages 15-23) combines interactive role-playing and graphing to introduce learners to the health affects of pollen. In the first part, learners role-play a detective on a medical case and the main character in the case. Learners formulate a hypothesis about a patient's illness. In the second part, learners graph evidence based on pollen counts and create a "final report" about what caused the patient's health problem. This activity smoothly combines health education, environmental science, and math.

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

    SciTech Connect

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

    2013-01-15

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

  9. Thinking About Medical School?

    E-print Network

    de Lijser, Peter

    Thinking About Medical School? Explore the DO Difference! Osteopathic Medical Education Training's Osteopathic Medical Schools · Meet with Medical School Admission Officers · Learn about osteopathic medicine and medical schools · Discover the best ways to prepare for medical school When Where Pre-Health Advisor

  10. Touchfree medical interfaces.

    PubMed

    Rossol, Nathaniel; Cheng, Irene; Rui Shen; Basu, Anup

    2014-01-01

    Real-time control of visual display systems via mid-air hand gestures offers many advantages over traditional interaction modalities. In medicine, for example, it allows a practitioner to adjust display values, e.g. contrast or zoom, on a medical visualization interface without the need to re-sterilize the interface. However, when users are holding a small tool (such as a pen, surgical needle, or computer stylus) the need to constantly put the tool down in order to make hand gesture interactions is not ideal. This work presents a novel interface that automatically adjusts for gesturing with hands and hand-held tools to precisely control medical displays. The novelty of our interface is that it uses a single set of gestures designed to be equally effective for fingers and hand-held tools without using markers. This type of interface was previously not feasible with low-resolution depth sensors such as Kinect, but is now achieved by using the recently released Leap Motion controller. Our interface is validated through a user study on a group of people given the task of adjusting parameters on a medical image. PMID:25571508

  11. On the feasibility of electron cyclotron heating of overcritical plasma in a magnetic mirror trap

    SciTech Connect

    Vodopyanov, A. V.; Golubev, S. V.; Gospodchikov, E. D.; Smolyakova, O. B.; Suvorov, E. V. [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)

    2012-06-15

    The feasibility of matching electromagnetic radiation in the electron cyclotron frequency range to a dense plasma in an open magnetic trap by producing an inverted (with a minimum on the axis) plasma density profile is discussed. The use of such a profile shows promise for the implementation of efficient cyclotron heating at plasma densities above the critical density, at which the Langmuir frequency is equal to the heating radiation frequency. Examples of the magnetic field and plasma density distributions in a mirror trap are presented for which analysis of the beam trajectories shows the feasibility of efficient electron cyclotron absorption of microwave beams in overcritical plasma.

  12. Heavy ion development at the LBL (Lawrence Berkeley Laboratory) 88-inch cyclotron

    SciTech Connect

    Clark, D.J.; Lyneis, C.M.

    1989-05-01

    The 88-Inch Cyclotron produces a wide range of ions for basic and applied research. The 6.4 GHz ECR source has completely replaced the PIG source, giving higher charge states and higher cyclotron energies. The ECR source has produced ions of 34 elements, of which 28 have been accelerated in the cyclotron, using gases, and low and high temperature ovens. A higher frequency 14.5 GHz advanced ECR is now under construction. It will further increase the charge states and energies available. A conceptual design has been done for a superconducting ECR driven by a gyrotron at 28 GHz. 8 refs., 5 figs., 1 tab.

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

    SciTech Connect

    Park, Jin Ah [Lab. of Accelerator and Medical Engineering, School of Information and Communication, Engineering, SungKyunKwan University, 300 Cheoncheon-dong, Suwon Gyeonggido 440-746 (Korea, Republic of); Gad, Kh. M. M. [Department of Energy Science, SungKyunKwan University, 300 Cheoncheon-dong, Suwon Gyeonggi-do 440-330 (Korea, Republic of); Chai, Jong-Seo [Lab. of Accelerator and Medical Engineering, School of Information and Communication, Engineering, SungKyunKwan University, 300 Cheoncheon-dong, Suwon Gyeonggido 440-746 (Korea, Republic of); Department of Energy Science, SungKyunKwan University, 300 Cheoncheon-dong, Suwon Gyeonggi-do 440-330 (Korea, Republic of)

    2011-06-01

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

  14. Spiraling ion beam driven electrostatic ion cyclotron wave instabilities in collisionless dusty plasma

    NASA Astrophysics Data System (ADS)

    Sharma, Shatendra; Sharma, Jyotsna

    2014-08-01

    The numerical calculations of the growth rate in long parallel wavelength are made for a spiraling ion beam propagating through a collision less magnetized dusty plasma cylinder that drives electrostatic ion cyclotron waves to instability via cyclotron interaction. It is found that the growth rate of the instability of the electrostatic ion cyclotron waves increase in the long parallel limit with the density ratio of negatively charged dust grains to electrons. The growth rate of the unstable mode has the maximum value for the modes whose Eigen functions peak at the location of the beam and varies as the one-third power of the beam current in both the limits.

  15. Cyclotron humps in AM HER systems. IV - Variations around the orbit in MR SER

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, D. T.; Cropper, Mark; Mason, K. O.; Garlick, M.

    1991-06-01

    Phase-resolved spectroscopy of MR Ser in which cyclotron harmonics are evident are presented. These move with viewing angle. Asymmetries in the movement and profiles of the humps indicate that the cyclotron remission region is extended. This region is modeled to deduce a magnetic field of 24.5 + or - 0.5 MG. Halo Zeeman absorption features which yield a similar field are also observed, confirming that the two emission regions are closely associated. Photospheric Zeeman features yield a polar field of 26 MG (assuming a centered dipole) consistent with the field in the cyclotron and halo emission regions if these are some 20 deg from the magnetic pole.

  16. Production of rare isotope beams at the Texas A and M University Cyclotron Institute

    SciTech Connect

    Tabacaru, G.; May, D. P.; Chubarian, G.; Clark, H.; Kim, G. J.; Tribble, R. E. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843-3366 (United States); Arje, J. [Accelerator Laboratory, University of Jyvaeskylae, Jyvaeskylae (Finland)

    2012-02-15

    The Cyclotron Institute at Texas A and M is currently configuring a scheme for the production of radioactive-ion beams that incorporates a light-ion guide and a heavy-ion guide coupled with an electron-cyclotron-resonance ion source constructed for charge-breeding. This scheme is part of an upgrade to the facility and is intended to produce radioactive beams suitable for injection into the K500 superconducting cyclotron. The current status of the project and details on the ion sources used in the project is presented.

  17. Medical Marketing Semi MedicalMarketingSemi

    E-print Network

    Buehrer, R. Michael

    U.S. ARMY Medical Marketing Semi WELCOME U.S.ARMY MedicalMarketingSemi Virginia Tech DATE: 23 October 2014 TIME: 8:00 am - 8:00 pm LOCATION: On Campus The Medical Marketing Semi is an operationally flexible, mobile medical exhibit. The MMS has various peripheral multi-media systems and displays

  18. MEDICAL EMERGENCIES What is a medical emergency?

    E-print Network

    Fernandez, Eduardo

    assistance Following the arrangement of emergency medical treatment for the injured employee, supervisor mustMEDICAL EMERGENCIES What is a medical emergency? Serious injury or illness. What do I do if there is a medical emergency occurring or one has occurred? CALL 911. Paramedics and ambulance service

  19. MEDICAL EMERGENCIES What is a medical emergency?

    E-print Network

    Fernandez, Eduardo

    assistance Following the arrangement of emergency medical treatment for the injured employee, supervisorMEDICAL EMERGENCIES What is a medical emergency? Serious injury or illness. What do I do if there is a medical emergency occurring or one has occurred? CALL 911. Paramedics and ambulance service

  20. Development of gas pulsing system for electron cyclotron resonance ion source

    SciTech Connect

    Hojo, S.; Honma, T.; Muramatsu, M.; Sakamoto, Y.; Sugiura, A. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

    2008-02-15

    A gas-pulsing system for an electron cyclotron resonance ion source with all permanent magnets (Kei2 source) at NIRS has been developed and tested. The system consists of a small vessel (30 ml) to reserve CH{sub 4} gas and two fast solenoid valves that are installed at both sides of the vessel. They are connected to each other and to the Kei2 source by using a stainless-steel pipe (4 mm inner diameter), where the length of the pipe from the valve to the source is 60 cm and the conductance is 1.2 l/s. From the results of the test, almost 300 e {mu}A for a pulsed {sup 12}C{sup 4+} beam was obtained at a Faraday cup in an extraction-beam channel with a pressure range of 4000 Pa in the vessel. At this time, the valve has an open time of 10 ms and the delay time between the valve open time and the application of microwave power is 100 ms. In experiments, the conversion efficiency for input CH{sub 4} molecules to the quantity of extracted {sup 12}C{sup 4+} ions in one beam pulse was found to be around 3% and the ratio of the total amount of the gas requirement was only 10% compared with the case of continuous gas provided in 3.3 s of repetition in HIMAC.

  1. Distorted Cyclotron Line Profile in Cep X-4 as Observed by NuSTAR

    NASA Astrophysics Data System (ADS)

    Fürst, F.; Pottschmidt, K.; Miyasaka, H.; Bhalerao, V.; Bachetti, M.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.; Grinberg, V.; Hailey, C. J.; Harrison, F. A.; Kennea, J. A.; Rahoui, F.; Stern, D.; Tendulkar, S. P.; Tomsick, J. A.; Walton, D. J.; Wilms, J.; Zhang, W. W.

    2015-06-01

    We present spectral analysis of Nuclear Spectroscopic Telescope Array and Swift observations of Cep X-4 during its outburst in 2014. We observed the source once during the peak of the outburst and once during the decay, finding good agreement in the spectral shape between the observations. We describe the continuum using a power law with a Fermi–Dirac cutoff at high energies. Cep X-4 has a very strong cyclotron resonant scattering feature (CRSF) around 30 keV. A simple absorption-like line with a Gaussian optical depth or a pseudo-Lorentzian profile both fail to describe the shape of the CRSF accurately, leaving significant deviations at the red side of the line. We characterize this asymmetry with a second absorption feature around 19 keV. The line energy of the CRSF, which is not influenced by the addition of this feature, shows a small but significant positive luminosity dependence. With luminosities between (1–6) × 1036 erg s?1, Cep X-4 is below the theoretical limit where such a correlation is expected. This behavior is similar to Vela X-1 and we discuss parallels between the two systems.

  2. Electron cyclotron resonance 140 mA D(+) beam extraction optimization for IFMIF EVEDA accelerator.

    PubMed

    Delferrière, O; De Menezes, D; Gobin, R; Harrault, F; Tuske, O

    2008-02-01

    Based on the experience of the SILHI electron cyclotron resonance (ECR) ion source for the IPHI accelerator, which produces routinely 100-120 mA H(+) beam, the CEA-Saclay is in charge of the design and realization of the 140 mA cw deuteron source for the IFMIF project (International Fusion Materials Irradiation Facility). IFMIF is an accelerator-based neutron irradiation facility consisting of two accelerators of 125 mA D(+) beam at 40 MeV that hit in parallel a lithium target. IFMIF utilizes the deuteron-lithium (d-Li) neutron, producing a reaction to simulate the 14 MeV neutron environment in deuterium-tritium (D-T) fusion reactors. In the framework of the IFMIF EVEDA phase (Engineering Validation and Engineering Design Activities), we are studying a cw ECR ion source with a new extraction system to allow high current extraction while keeping a low divergence as well as a small emittance. Starting from SILHI five-electrode system with H(+) ions, the extracted beam characteristics as well as electric field conditions are compared with the cases of four- and three-electrode extraction systems. Experimental results made on the SILHI source with H(+) ions are briefly discussed. Extensive experimental results on the new source test bench BETSI are expected as soon as the design and fabrication of a dedicated extraction system with a new set of electrodes will be finished. PMID:18315214

  3. Electron cyclotron resonance 140mA D+ beam extraction optimization for IFMIF EVEDA acceleratora)

    NASA Astrophysics Data System (ADS)

    Delferrière, O.; De Menezes, D.; Gobin, R.; Harrault, F.; Tuske, O.

    2008-02-01

    Based on the experience of the SILHI electron cyclotron resonance (ECR) ion source for the IPHI accelerator, which produces routinely 100-120mA H+ beam, the CEA-Saclay is in charge of the design and realization of the 140mA cw deuteron source for the IFMIF project (International Fusion Materials Irradiation Facility). IFMIF is an accelerator-based neutron irradiation facility consisting of two accelerators of 125mA D+ beam at 40MeV that hit in parallel a lithium target. IFMIF utilizes the deuteron-lithium (d-Li) neutron, producing a reaction to simulate the 14MeV neutron environment in deuterium-tritium (D-T) fusion reactors. In the framework of the IFMIF EVEDA phase (Engineering Validation and Engineering Design Activities), we are studying a cw ECR ion source with a new extraction system to allow high current extraction while keeping a low divergence as well as a small emittance. Starting from SILHI five-electrode system with H+ ions, the extracted beam characteristics as well as electric field conditions are compared with the cases of four- and three-electrode extraction systems. Experimental results made on the SILHI source with H+ ions are briefly discussed. Extensive experimental results on the new source test bench BETSI are expected as soon as the design and fabrication of a dedicated extraction system with a new set of electrodes will be finished.

  4. Alternative optical concept for electron cyclotron emission imaging

    SciTech Connect

    Liu, J. X., E-mail: jsliu9@berkeley.edu [Department of Physics, University of California Berkeley, Berkeley, California 94720 (United States); Milbourne, T. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23185 (United States); Bitter, M.; Delgado-Aparicio, L.; Dominguez, A.; Efthimion, P. C.; Hill, K. W.; Kramer, G. J.; Kung, C.; Pablant, N. A.; Tobias, B. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Kubota, S. [Department of Physics, University of California Los Angeles, Los Angeles, California 90095 (United States); Kasparek, W. [Department of Electrical Engineering, University of Stuttgart, Stuttgart (Germany); Lu, J. [Department of Physics, Chongqing University, Chongqing 400044 (China); Park, H. [Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of)

    2014-11-15

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

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

    NASA Technical Reports Server (NTRS)

    Winske, D.; Omidi, N.

    1992-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Winske, D.; Omidi, N.

    1992-10-01

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

  7. Electromagnetic ion cyclotron waves stimulated by modest magnetospheric compressions

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  8. Enhanced confinement in electron cyclotron resonance ion source plasma

    SciTech Connect

    Schachter, L.; Dobrescu, S. [National Institute for Physics and Nuclear Engineering, Bucharest (Romania); Stiebing, K. E. [Institut fuer Kernphysik der J. W. Goethe-Universitaet, Frankfurt/Main (Germany)

    2010-02-15

    Power loss by plasma-wall interactions may become a limitation for the performance of ECR and fusion plasma devices. Based on our research to optimize the performance of electron cyclotron resonance ion source (ECRIS) devices by the use of metal-dielectric (MD) structures, the development of the method presented here, allows to significantly improve the confinement of plasma electrons and hence to reduce losses. Dedicated measurements were performed at the Frankfurt 14 GHz ECRIS using argon and helium as working gas and high temperature resistive material for the MD structures. The analyzed charge state distributions and bremsstrahlung radiation spectra (corrected for background) also clearly verify the anticipated increase in the plasma-electron density and hence demonstrate the advantage by the MD-method.

  9. Electron Cyclotron Measurements on the Maryland Centrifugal Experiment

    NASA Astrophysics Data System (ADS)

    Reid, Remington; Young, William; Allen, Christina; Ellis, Richard; Romero-Talamas, Carlos; Hassam, Adil

    2011-10-01

    The Maryland Centrifugal Experiment (MCX) uses supersonic rotation to stabilize dense plasmas (n ~1014/cc) confined in an axisymmetric magnetic mirror. This rotation is generated using an axial electrode to drive large radial currents though the plasma. The MCX plasma delivers a sufficient heat flux to make the vast majority of the plasma inaccessible to electrostatic probes, making direct measurements of the electron temperature unworkable. Electron cyclotron radiation, propagating in the whistler mode has been used in past experiments to measure the axial electron temperature distribution in mirror type machines and has the advantage of working in very dense plasmas. A radiometer has been installed on MCX to measure this radiation and the axial electron temperature is being measured. Abrupt changes in the intensity of the ECE radiation are correlated with bulk plasma instabilities provide information to further diagnose these instabilities.

  10. Concept for a fourth generation electron cyclotron resonance ion source.

    PubMed

    Lyneis, C; Ferracin, P; Caspi, S; Hodgkinson, A; Sabbi, G L

    2012-02-01

    A fourth generation electron cyclotron resonance ion source with an operating frequency between 40 and 56 GHz has the potential to quadruple the heavy-ion beam currents and provide a cost effective upgrade path for heavy ion drivers in use or in the planning stage at radioactive beam facilities. Design studies show it is feasible to produce the required magnetic fields in the plasma chamber, 7 T axially and 4 T in the radial direction with a magnetic structure using commercially available Nb(3)Sn superconducting materials. In this paper we describe the design of such a magnet structure including a 3D analysis of the Lorentz forces generated by the magnetic fields and the necessary clamping structure to stabilize the conductor against these forces. PMID:22380148

  11. Finite banana width effect on magnetoacoustic cyclotron instability

    SciTech Connect

    Chen, Y.P.; Tsai, S.T. [Institute of Physics, Academia Sinica, Beijing 100080 (China)] [Institute of Physics, Academia Sinica, Beijing 100080 (China)

    1995-08-01

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

  12. Parametric instabilities during electron cyclotron heating of tandem mirrors

    NASA Technical Reports Server (NTRS)

    Nicholson, D. R.

    1984-01-01

    Electron cyclotron resonance heating is one of the most commonly used methods of heating electrons in the plugs and in the thermal barriers of tandem mirrors. The intense coherent electromagnetic waves used for such heating are susceptible to parametric decay into other modes. Significant growth rates are found for the decay of either ordinary or extraordinary waves into two magnetized electron plasma waves. This and related effects may result in electron heating mechanisms rather different than those assumed in linear ray-tracing calculations. These results may help explain the unusual effects observed during heating of the Phaedrus tandem mirror device. In the general case, these instabilities may be strongly inhibited by density gradients.

  13. Recent developments of cyclotron produced radionuclides for nuclear cardiology

    NASA Astrophysics Data System (ADS)

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

    1987-04-01

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

  14. ICR study of nonreactive ion-molecule collision rate constants for Cl/-/ and Cr/CO/5/-/. [Ion Cyclotron Resonance

    NASA Technical Reports Server (NTRS)

    Dymerski, P. P.; Dunbar, R. C.; Dugan, J. V., Jr.

    1974-01-01

    Determination of experimental momentum transfer rate constants for systems of Cl(-) and Cr(CO)5(-) ions by means of an ion cyclotron resonance (ICR) line-broadening technique. It is found that in the pure polarization limit of small ion/large neutral collisions the Langevin ion mobility theory gives good agreement with experimental results. A comparison of isotropic and anisotropic neutral systems suggests that a correction for the anisotropic systems is necessary. Beyond the pure polarization limit the Langevin theory gives poor predictions for ion mobilities. The adjustable parameter, gamma, of the Mason-Schamp (12-6-4) potential function permits unique solution of the ion mobility for Cr(CO)5(-) in a wide range of neutral gases. The large values of gamma obtained for most of these systems imply, in terms of the Mason-Schamp theory, that the r to the minus 6th power contribution to the potential function is significant.

  15. Chirped dissipative ion-cyclotron solitons in the Earth's low-altitude ionospheric plasma with two ion species

    SciTech Connect

    Kovaleva, I. Kh. [Russian Academy of Sciences, Institute of Geosphere Dynamics (Russian Federation)] [Russian Academy of Sciences, Institute of Geosphere Dynamics (Russian Federation)

    2013-03-15

    Conditions for the excitation of small-scale nonlinear ion-cyclotron gradient-drift dissipative structures in cold ionospheric plasma are considered. The solution for the wave electric field in this structure in the form of a chirped soliton satisfying the equation of the Ginzburg-Landau type is derived in the electrostatic approach. The dissipative structure as a whole represents the chirped soliton accompanied by the comoving quasineutral plasma hump. The possibility of the excitation of two modes of this type (the high- and low-frequency ones) in plasma containing light and heavy ion impurities is considered. The role of electromagnetic corrections and the possible contribution introduced by these structures to the transport processes in the ionosphere are discussed.

  16. Business ethics, medical ethics and economic medicalization

    Microsoft Academic Search

    Geoffrey Poitras

    2009-01-01

    This paper explores the ethical implications of economic medicalization: where non-medical problems are transformed into medical problems in order to achieve the objective of shareholder wealth maximization. After considering differences between business ethics and medical ethics, economic medicalization arising from corporate marketing strategies is detailed. Both direct-to-consumer and more traditional physician centred marketing methods are considered. In addition, the economic

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

    PubMed

    Muramatsu, M; Kitagawa, A

    2012-02-01

    There are two major medical applications of ion accelerators. One is a production of short-lived isotopes for radionuclide imaging with positron emission tomography and single photon emission computer tomography. Generally, a combination of a source for negative ions (usually H- and/or D-) and a cyclotron is used; this system is well established and distributed over the world. Other important medical application is charged-particle radiotherapy, where the accelerated ion beam itself is being used for patient treatment. Two distinctly different methods are being applied: either with protons or with heavy-ions (mostly carbon ions). Proton radiotherapy for deep-seated tumors has become widespread since the 1990s. The energy and intensity are typically over 200 MeV and several 10(10) pps, respectively. Cyclotrons as well as synchrotrons are utilized. The ion source for the cyclotron is generally similar to the type for production of radioisotopes. For a synchrotron, one applies a positive ion source in combination with an injector linac. Carbon ion radiotherapy awakens a worldwide interest. About 6000 cancer patients have already been treated with carbon beams from the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan. These clinical results have clearly verified the advantages of carbon ions. Heidelberg Ion Therapy Center and Gunma University Heavy Ion Medical Center have been successfully launched. Several new facilities are under commissioning or construction. The beam energy is adjusted to the depth of tumors. It is usually between 140 and 430 MeV?u. Although the beam intensity depends on the irradiation method, it is typically several 10(8) or 10(9) pps. Synchrotrons are only utilized for carbon ion radiotherapy. An ECR ion source supplies multi-charged carbon ions for this requirement. Some other medical applications with ion beams attract developer's interests. For example, the several types of accelerators are under development for the boron neutron capture therapy. This treatment is conventionally demonstrated by a nuclear reactor, but it is strongly expected to replace the reactor by the accelerator. We report status of ion source for medical application and such scope for further developments. PMID:22380341

  18. Experiments on the creation of einsteinium and fermium in a cyclotron

    Microsoft Academic Search

    L. I. Guseva; K. V. Filippova; Yu. B. Gerlit; V. A. Druin; B. F. Myasoedov; N. I. Tarantin

    1956-01-01

    In this article we present the results of some experiments on the creation of einsteinium and fermium by cyclotron irradiation of a uranium target with quintuply charged nitrogen ions (N V) and sextuply charged oxygen ions (O VI).

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

    SciTech Connect

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

    1988-08-01

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

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

    SciTech Connect

    Not Available

    1980-06-01

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

  1. Ultracompact superconducting isochronous cyclotron production of ¹³N for positron emission tomography applications

    E-print Network

    Fitzgerald, Shawn (Shawn Michael)

    2013-01-01

    Testing was performed on a data acquisition (DAQ) system that was built specifically to characterize a new ultracompact superconducting isochronous cyclotron (USIC) at MIT. A production model of Nitrogen-13 was validated ...

  2. Theory of the current-driven ion-cyclotron instability in the bottomside ionosphere. Memorandum report

    Microsoft Academic Search

    P. Satyanarayana; P. K. Chaturvedi; M. J. Keskinen; J. D. Huba; S. L. Ossakow

    1985-01-01

    A theory of the current-driven electrostatic ion-cyclotron(EIC) instability in the collisional bottomside ionosphere is presented. It is found that the electron collisions are destabilizing and are crucial for the excitation of the EIC instability in the collisional bottomside ionosphere. Furthermore, the growth rates of the ion cyclotron instability in the bottomside ionosphere maximize for (K-perpendicular) (rho\\/sub i\\/) > or =

  3. V-Shaped dc Potential Structure Caused by Current-Driven Electrostatic Ion-Cyclotron Instability

    Microsoft Academic Search

    Seiji Ishiguro; Tetsuya Sato; Hisanori Takamaru

    1997-01-01

    It is first demonstrated that a V-shaped dc potential structure is created by a current-driven electrostatic ion-cyclotron instability by means of an open two-dimensional particle simulation model. A positive dc potential difference along magnetic field lines is generated by anomalous resistivity caused by the ion-cyclotron instability. In the direction across the magnetic field lines, the dc potential rises from the

  4. V-shaped Potential Structure Formation due to Current-driven Electrostatic Ion-cyclotron Instability

    Microsoft Academic Search

    Seiji Ishiguro; Tetsuya Sato

    2000-01-01

    Formation of dc potential structure in a magnetized plasma due to electrostatic current-driven ion-cyclotron instabilities has been investigated by means of a self-consistent open boundary two-and-a-half dimensional electrostatic particle in cell simulation model. It is found that a V-shaped potential structure is created due to current-driven electrostatic ion cyclotron instability for a bell-shaped electron stream along the magnetic field lines.

  5. Formation of wave-front pattern accompanied by current-driven electrostatic ion-cyclotron instabilities

    Microsoft Academic Search

    Seiji Ishiguro; Tetsuya Sato; Hisanori Takamaru; Kunihiko Watanabe

    1997-01-01

    Formation of a wave-front pattern accompanied by an electrostatic ion-cyclotron instability driven by electrons drifting along a magnetic field is investigated by two-and-half dimensional particle simulations. A clear spatial wave-front pattern appears as the ion cyclotron wave grows due to the instability. When the electron stream is uniform in the system, an obliquely intersected stripe wave-front pattern is formed. When

  6. Stabilization of the current-driven electrostatic ion-cyclotron instability by lower-hybrid waves

    Microsoft Academic Search

    N. S. Wolf; R. Majeski; V. Tripathi; C. S. Liu; H. Lashinsky

    1980-01-01

    The current-driven electrostatic ion-cyclotron instability in a Q machine operated in the low-density regime the square of the ratio of the electron plasma frequency to the electron cyclotron frequency is much less than 1 is stabilized by externally generated RF electrostatic fields in the lower-hybrid range. Stabilization is due to a resonant ponderomotive force, which reduces the instability frequency, thus

  7. X-ray pulsar models. I. Angle-dependent cyclotron line formation and comptonization

    SciTech Connect

    Meszaros, P.; Nagel, W.

    1985-11-01

    A multiangle, incoherent scattering formalism that yields pulse phase spectroscopic information is used to calculate spectra and cyclotron line shapes of static X-ray pulsar atmospheres with slab and column geometry. Comparisons with observations of integrated spectra and of phase-dependent cyclotron line properties indicates a better fit for the slab models. The illumination of inner or outer boundaries by external photon sources is allowed for, and the examples considered are an arbitrary input at the inner boundary. 42 references.

  8. Thermal effects on the cyclotron line formation process in x-ray pulsars

    SciTech Connect

    Kirk, J.G.; Meszaros, P.

    1980-11-01

    We derive expressions for the scattering and absorption cross sections of photons in a hot plasma including the effects of vacuum polarization in a strong magnetic field. Near the cyclotron resonance, these expressions depart significantly from previous cold plasma calculations. An approximate calculation of the radiative transfer is presented, and cyclotron absorption and emission-line fits are compared. This simplified transfer model suggests that an emission-line interpretation is slightly more probable at this stage.

  9. Observing the Quantum Limit of an Electron Cyclotron: QND Measurements of Quantum Jumps between Fock States

    Microsoft Academic Search

    S. Peil; G. Gabrielse

    1999-01-01

    Quantum jumps between Fock states of a one-electron oscillator reveal the quantum limit of a cyclotron. With a surrounding cavity inhibiting synchrotron radiation 140-fold, the jumps show a 13 s Fock state lifetime and a cyclotron in thermal equilibrium with 1.6 to 4.2 K blackbody photons. These disappear by 80 mK, a temperature 50 times lower than previously achieved with

  10. Hybrid Simulations of Wave Propagation and Ion Cyclotron Heating in the Expanding Solar Wind

    Microsoft Academic Search

    Paulett Liewer; Marco Velli; Bruce Goldstein

    1999-01-01

    We present results from hybrid (particle ions, fluid electrons) simulations of the evolution of Alfvén waves close to the\\u000a ion cyclotron frequency in the solar wind, which take into account the basic properties of the background solar wind flow,\\u000a i.e., the spherical expansion and the consequent decrease in magnetic field and cyclotron frequency with increasing distance\\u000a from the Sun. We

  11. Experimental verification of beam characteristics for cyclotron-based epithermal neutron source (C-BENS)

    Microsoft Academic Search

    H. Tanaka; Y. Sakurai; M. Suzuki; S. Masunaga; T. Mitsumoto; K. Fujita; G. Kashino; Y. Kinashi; Y. Liu; M. Takada; K. Ono; A. Maruhashi

    2011-01-01

    A cyclotron-based epithermal neutron source has been developed for boron neutron capture therapy. This system consists of a cyclotron accelerator producing 1.1-mA proton beams with an energy of 30MeV, a beam transport system coupled with a beryllium neutron production target, and a beam-shaping assembly (BSA) with a neutron collimator. In our previous work, the BSA was optimized to obtain sufficient

  12. Study of the neutron field in the vicinity of an unshielded PET cyclotron

    Microsoft Academic Search

    R. Méndez; M. P. Iñiguez; J. M. Martí-Climent; I. Peñuelas; H. R. Vega-Carrillo; R. Barquero

    2005-01-01

    The neutron field in the proximity of an unshielded PET cyclotron was investigated during 18F radioisotope production with an 18 MeV proton beam. Thermoluminescent detector (TLD) models TLD600 and TLD700 as well as Bonner moderating spheres were irradiated at different positions inside the vault room where the cyclotron is located to determine the thermal neutron flux, neutron spectrum and dose

  13. Ion Cyclotron Production by a Four-Wave Interaction with a Helicon Pump

    SciTech Connect

    Sutherland, O.; Giles, M.; Boswell, R. [Plasma Research Laboratory, RSPhysSE, Australian National University, 0200, Canberra (Australia)

    2005-05-27

    Ion cyclotron waves at approximately 0.7 the ion gyrofrequency have been observed experimentally in the large volume helicon reactor WOMBAT. These waves are highly localized along the axis of the device where a 8 cm diameter, 2 m long. Ar II plasma column is produced. Spectral measurements reveal a four-wave interaction where energy is down-converted to the ion cyclotron mode from the helicon pump. The experimental results are explained in terms of a filamentation type instability.

  14. STATUS REPORT OF THE U400 CYCLOTRON AT THE FLNR JINR

    Microsoft Academic Search

    G. G. Gulbekyan; B. N. Gikal; I. V. Kalagin; V. B. Kutner; S. L. Bogomolov

    2004-01-01

    The isochronous U400 cyclotron has been constructed and put into operation since 1978. The cyclotron produces ion beams of atomic masses from 4 to 209 at maximum energy up to 26 MeV\\/nucleon. Since 1996, the U400 axial injection system with the ECR4M ion source has been constructed and put into operation. To increase output intensity, the double buncher system (Sine

  15. Experimental demonstration of an electromagnetically pumped free-electron laser with a cyclotron-harmonic idler

    Microsoft Academic Search

    R. A. Kehs; Y. Carmel; V. L. Granatstein; W. W. Destler

    1988-01-01

    A three-wave, free-electron laser was operated with a powerful 8.4-GHz electromagnetic ''pump'' wave replacing the usual magnetostatic wiggler. The presence of a uniform axial magnetic field Bâ produced cyclotron-harmonic ''idler'' waves. Peaks in the emission spectrum corresponding to cyclotron harmonics were observed covering a frequency range from 16.5 to 130 GHz. The frequency spectrum of this novel free-electron laser mechanism

  16. Cyclotron resonance study of the electron and hole velocity in graphene monolayers

    Microsoft Academic Search

    R. S. Deacon; K.-C. Chuang; R. J. Nicholas; K. S. Novoselov; A. K. Geim

    2007-01-01

    We report studies of cyclotron resonance in monolayer graphene. Cyclotron\\u000aresonance is detected using the photoconductive response of the sample for\\u000aseveral different Landau level occupancies. The experiments measure an electron\\u000avelocity at the K- (Dirac) point of $c_{K}^{*}$ = 1.093 x 10$^{6}$ ms$^{-1}$\\u000aand in addition detect a significant asymmetry between the electron and hole\\u000abands, leading to a

  17. Multi-Species Test of Ion Cyclotron Resonance Heating at High Altitudes

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    Observations of ion distributions and plasma waves obtained by the Dynamics Explorer 1 satellite in the high-altitude, nightside auroral zone are used to study ion energization for three ion species. A number of theoretical models have been proposed to account for the transverse heating of these ion populations. One of these, the ion cyclotron resonance heating (ICRH) mechanism, explains ion conic formation through ion cyclotron resonance with broadband electromagnetic wave turbulence in the vicinity of the characteristic ion cyclotron frequency. The cyclotron resonant heating of the ions by low- frequency electromagnetic waves is an important energy source for the transport of ions from the ionosphere to the magnetosphere. In this paper we test the applicability of the ICRH mechanism to three simultaneously heated and accelerated ion species by modelling the ion conic formation in terms of a resonant wave-particle interaction in which the ions extract energy from the portion of the broadband electromagnetic wave spectrum which includes the ion cyclotron frequency. Using a Monte Carlo technique we evaluate the ion heating produced by the electromagnetic turbulence at low frequencies and find that the wave amplitudes near the ion cyclotron frequencies are sufficient to explain the observed ion energies.

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

    PubMed

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

    2014-02-01

    The JAEA AVF cyclotron accelerates various kinds of high-energy ion beams for research in biotechnology and materials science. Beam intensities of an ion species of the order of 10(-9)-10(-6) ampere are often required for various experiments performed sequentially over a day. To provide ion beams with sufficient intensity and stability, an operator has to retune an ion source in a short time. However, the beam intensity downstream of the cyclotron rarely increases in proportion to the intensity at the ion source. To understand the cause of this beam behavior, transmission efficiencies of a (12)C(5+) beam from an electron cyclotron resonance ion source to the cyclotron were measured for various conditions of the ion source. Moreover, a feasible region for acceleration in the emittance of the injection beam was clarified using a transverse-acceptance measuring system. We confirmed that the beam emittance and profile were changed depending on the condition of the ion source and that matching between the beam emittance and the acceptance of the cyclotron was degraded. However, after fine-tuning to improve the matching, beam intensity downstream of the cyclotron increased. PMID:24593459

  19. First operation of the charge-breeder electron-cyclotron-resonance ion source at the Texas A and M Cyclotron Institute

    SciTech Connect

    May, D. P.; Tabacaru, G.; Abegglen, F. P. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States); Cornelius, W. D. [Scientific Solutions, P.O. Box 500207, San Diego, California 92150 (United States)

    2010-02-15

    The 14.5 GHz electron-cyclotron-resonance ion source (ECRIS) designed and fabricated specifically for charge breeding has been installed at the Texas A and M University Cyclotron Institute for use in the institute's ongoing radioactive-ion-beam upgrade. The initial testing of the source has just begun with magnetic analysis of the ECRIS beam. The source has only been conditioning for a brief time at low microwave power, and it is continuing to improve. After the source has been conditioned and characterized, charge-breeding trials with stable beams from a singly ionizing source will begin.

  20. Mobile medical image retrieval

    NASA Astrophysics Data System (ADS)

    Duc, Samuel; Depeursinge, Adrien; Eggel, Ivan; Müller, Henning

    2011-03-01

    Images are an integral part of medical practice for diagnosis, treatment planning and teaching. Image retrieval has gained in importance mainly as a research domain over the past 20 years. Both textual and visual retrieval of images are essential. In the process of mobile devices becoming reliable and having a functionality equaling that of formerly desktop clients, mobile computing has gained ground and many applications have been explored. This creates a new field of mobile information search & access and in this context images can play an important role as they often allow understanding complex scenarios much quicker and easier than free text. Mobile information retrieval in general has skyrocketed over the past year with many new applications and tools being developed and all sorts of interfaces being adapted to mobile clients. This article describes constraints of an information retrieval system including visual and textual information retrieval from the medical literature of BioMedCentral and of the RSNA journals Radiology and Radiographics. Solutions for mobile data access with an example on an iPhone in a web-based environment are presented as iPhones are frequently used and the operating system is bound to become the most frequent smartphone operating system in 2011. A web-based scenario was chosen to allow for a use by other smart phone platforms such as Android as well. Constraints of small screens and navigation with touch screens are taken into account in the development of the application. A hybrid choice had to be taken to allow for taking pictures with the cell phone camera and upload them for visual similarity search as most producers of smart phones block this functionality to web applications. Mobile information access and in particular access to images can be surprisingly efficient and effective on smaller screens. Images can be read on screen much faster and relevance of documents can be identified quickly through the use of images contained in the text. Problems with the many, often incompatible mobile platforms were discovered and are listed in the text. Mobile information access is a quickly growing domain and the constraints of mobile access also need to be taken into account for image retrieval. The demonstrated access to the medical literature is most relevant as the medical literature and their images are clearly the largest knowledge source in the medical field.

  1. Medical marketplace

    NASA Astrophysics Data System (ADS)

    Moretti, Michael

    1991-08-01

    Solid state lasers are the real highlight of my talk today, and were really the star of the year. In every application area I can think of, people have tried with some success to introduce corturiercial solid state products. I'll go into more detail, but aside from solid state, a very significant event happened in Deceniber when one of the laser angioplasty companies (Advanced Interventional Systens) received FDA clearance to begin marketing the excimer for coronary applications (Figure 1) . This is the first time to my knowledge that an excimer has ever been cleared for a medical application in the United States. It's an event that we didn't really expect to happen so soon. It's extremely significant and we'll see where it goes from here. The system needs to be road-tested a bit but to get past the FDA is the major obstacle. Looking back to solid state laser the importance of solid state lasers is as researchers become more involved with the excimer and conduct more clinical studies in ophthalmology, they realize that it's not going to be a panacea for all refractive surgery or other ophthalmolic applications. In many cases it looks like the solid state laser may be the laser of choice in certain types of surgery; most notably perhaps in refractive surgery. We've all read about the success of the excimer at least in capturing the press's attention for corneal sculpting and vision correction. Well, it could be that actually the next generation will be a solid state laser, so let's keep an open mind here.

  2. Lower hybrid current drive favoured by electron cyclotron radiofrequency heating

    SciTech Connect

    Cesario, R.; Cardinali, A.; Castaldo, C.; Marinucci, M.; Tuccillo, A. A. [Associazione EURATOM/ENEA sulla Fusione, Centro Ricerche Frascati, 00044, Frascati (Italy); Amicucci, L.; Galli, A. [Università di Roma Sapienza, Dipartimento Ingegneria Elettronica, Rome (Italy); Giruzzi, G. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Napoli, F.; Schettini, G. [Università di Roma Tre, Dipartimento Ingegneria Elettronica, Rome (Italy)

    2014-02-12

    The important goal of adding to the bootstrap a fraction of non-inductive plasma current, which would be controlled for obtaining and optimizing steady-state profiles, can be reached by using the Current Drive produced by Lower Hybrid waves (LHCD). FTU (Frascati Tokamak Upgrade) experiments demonstrated, indeed, that LHCD is effective at reactor-graded high plasma density, and the LH spectral broadening is reduced, operating with higher electron temperature in the outer region of plasma column (T{sub e-periphery}). This method was obtained following the guidelines of theoretical predictions indicating that the broadening of launched spectrum produced by parametric instability (PI) should be reduced, and the LHCD effect at high density consequently enabled, under higher (T{sub e-periphery}). In FTU, the temperature increase in the outer plasma region was obtained by operating with reduced particle recycling, lithized walls and deep gas fuelling by means of fast pellet. Heating plasma periphery with electron cyclotron resonant waves (ECRH) will provide a further tool for achieving steady-state operations. New FTU experimental results are presented here, demonstrating that temperature effect at the plasma periphery, affecting LH penetration, occurs in a range of plasma parameters broader than in previous work. New information is also shown on the modelling assessing frequencies and growth rates of the PI coupled modes responsible of spectral broadening. Finally, we present the design of an experiment scheduled on FTU next campaign, where ECRH power is used to slightly increase the electron temperature in the outer plasma region of a high-density discharge aiming at restoring LHCD. Consequent to model results, by operating with a toroidal magnetic field of 6.3 T, useful for locating the electron cyclotron resonant layer at the periphery of the plasma column (r/a?0.8, f{sub 0}=144 GHz), an increase of T{sub e} in the outer plasma (from 40 eV to 80 eV at r/a?0.8) is expected by the JETTO code, sufficient for recovering LHCD. An ECRH power of 0.8 MW, and the standard FTU regime at high plasma density (n{sub eav}?1.3×10{sup 20}m{sup ?3} and plasma current of 0.5 MA) have been considered. The code has been set with transport modelling to reproduce the evolution of FTU kinetic profiles.

  3. The Medical Home

    MedlinePLUS

    ... Keeping Kids Safe Concussions: What to Know The Medical Home KidsHealth > Parents > Doctors & Hospitals > Doctor & Hospital Visits > ... home" for your child. What Does the Term "Medical Home" Mean? A medical home isn't a ...

  4. Your Medical Records

    MedlinePLUS

    What Are Medical Records? Each time you climb up on a doctor's exam table or roll up your sleeve for a ... place to keep them private. What's in My Medical Records? You might picture your medical records as ...

  5. Medication/Drug Allergy

    MedlinePLUS

    ... of Allergy & Clinical Immunology View full profile Medication/Drug Allergy Allergies to medications/drugs are complicated because ... allergy symptoms. Learn more. Doctors Who Treat Medication/Drug Allergy Rohit K. Katial Harold S. Nelson Richard W. ...

  6. Ion Heating and High-Energy-Particle Production by Ion-Cyclotron Heating in the Large Helical Device

    Microsoft Academic Search

    T. Mutoh; R. Kumazawa; T. Seki; T. Watari; K. Saito; Y. Torii; D. A. Hartmann; Y. Zhao; M. Sasao; M. Isobe; M. Osakabe; A. V. Krasilnikov; T. Ozaki; K. Narihara; Y. Nagayama; S. Inagaki; F. Shimpo; G. Nomura; M. Yokota; K. Akaishi; N. Ashikawa; P. de Vries; M. Emoto; H. Funaba; A. Fukuyama; M. Goto; K. Ida; H. Idei; K. Ikeda; N. Inoue; K. Itoh; O. Kaneko; K. Kawahata; S. Kado; A. Komori; T. Kobuchi; S. Kubo; S. Masuzaki; T. Morisaki; S. Morita; J. Miyazawa; S. Murakami; T. Minami; S. Muto; Y. Nakamura; H. Nakanishi; N. Noda; K. Nishimura; K. Ohkubo; N. Ohyabu; S. Ohdachi; Y. Oka; H. Okada; B. J. Peterson; A. Sagara; K. Sato; S. Sakakibara; R. Sakamoto; H. Sasao; M. Sato; T. Shimozuma; M. Shoji; S. Sudo; H. Suzuki; Y. Takeiri; K. Tanaka; K. Toi; T. Tokuzawa; K. Tsumori; K. Y. Watanabe; T. Watanabe; H. Yamada; I. Yamada; S. Yamaguchi; K. Yamazaki; M. Yokoyama; Y. Yoshimura; Y. Hamada; O. Motojima; M. Fujiwara

    2000-01-01

    Ion-cyclotron heating was applied to the Large Helical Device. When the proton-cyclotron resonance was near the saddle point of the magnetic field-strength plane, strong ion-cyclotron damping occurred. Under these conditions efficient plasma heating was achieved for more than one minute. A high-energy ion tail was observed, and the effective tail temperature was determined by a balance between the wave acceleration

  7. Medical narratives in electronic medical records

    Microsoft Academic Search

    Huibert J Tange; Arie Hasman; Pieter F de Vries Robbé; Harry C Schouten

    1997-01-01

    In this article, we describe the state of the art and directions of current development and research with respect to the inclusion of medical narratives in electronic medical-record systems. We used information about 20 electronic medical-record systems as presented in the literature. We divided these systems into `classical' systems that matured before 1990 and are now used in a broad

  8. Advances in Medical Devices and Medical Electronics

    Microsoft Academic Search

    Michael R. Neuman; Gail D. Baura; Stuart Meldrum; Orhan Soykan; Max E. Valentinuzzi; Ron S. Leder; Silvestro Micera; Yuan-Ting Zhang

    2012-01-01

    Medical devices and medical electronics are areas that had little to offer 100 years ago. However, there were three important existing technologies that led to many further developments over the following 100 years. These are the stethoscope, electrocardiography, and X-ray medical imaging. Although these technologies had been described and were available to some extent when the Proceedings of the IEEE

  9. Spatially resolved charge-state and current-density distributions at the extraction of an electron cyclotron resonance ion source.

    PubMed

    Panitzsch, Lauri; Peleikis, Thies; Stalder, Michael; Wimmer-Schweingruber, Robert F

    2011-09-01

    In this paper we present our measurements of charge-state and current-density distributions performed in very close vicinity (15 mm) of the extraction of our hexapole geometry electron cyclotron resonance ion source. We achieved a relatively high spatial resolution reducing the aperture of our 3D-movable extraction (puller) electrode to a diameter of only 0.5 mm. Thus, we are able to limit the source of the extracted ion beam to a very small region of the plasma electrode's hole (Ø = 4 mm) and therefore to a very small region of the neutral plasma sheath. The information about the charge-state distribution and the current density in the plane of the plasma electrode at each particular position is conserved in the ion beam. We determined the total current density distribution at a fixed coaxial distance of only 15 mm to the plasma electrode by remotely moving the small-aperture puller electrode which contained a dedicated Faraday cup (FC) across the aperture of the plasma electrode. In a second measurement we removed the FC and recorded m/q-spectra for the different positions using a sector magnet. From our results we can deduce that different ion charge-states can be grouped into bloated triangles of different sizes and same orientation at the extraction with the current density peaking at centre. This confirms observations from other groups based on simulations and emittance measurements. We present our measurements in detail and discuss possible systematic errors. PMID:21974580

  10. Spatially resolved charge-state and current-density distributions at the extraction of an electron cyclotron resonance ion source

    SciTech Connect

    Panitzsch, Lauri; Peleikis, Thies; Stalder, Michael; Wimmer-Schweingruber, Robert F. [Institute for Experimental and Applied Physics (IEAP), Christian-Albrechts-Universitaet, Kiel (Germany)

    2011-09-15

    In this paper we present our measurements of charge-state and current-density distributions performed in very close vicinity (15 mm) of the extraction of our hexapole geometry electron cyclotron resonance ion source. We achieved a relatively high spatial resolution reducing the aperture of our 3D-movable extraction (puller) electrode to a diameter of only 0.5 mm. Thus, we are able to limit the source of the extracted ion beam to a very small region of the plasma electrode's hole (O = 4 mm) and therefore to a very small region of the neutral plasma sheath. The information about the charge-state distribution and the current density in the plane of the plasma electrode at each particular position is conserved in the ion beam. We determined the total current density distribution at a fixed coaxial distance of only 15 mm to the plasma electrode by remotely moving the small-aperture puller electrode which contained a dedicated Faraday cup (FC) across the aperture of the plasma electrode. In a second measurement we removed the FC and recorded m/q-spectra for the different positions using a sector magnet. From our results we can deduce that different ion charge-states can be grouped into bloated triangles of different sizes and same orientation at the extraction with the current density peaking at centre. This confirms observations from other groups based on simulations and emittance measurements. We present our measurements in detail and discuss possible systematic errors.

  11. Quasioptical design of integrated Doppler backscattering and correlation electron cyclotron emission systems on the DIII-D tokamak

    E-print Network

    Rhodes, T. L.

    The quasioptical design of a new integrated Doppler backscattering (DBS) and correlation electron cyclotron emission (CECE) system is presented. The design provides for simultaneous measurements of intermediate wavenumber ...

  12. Nanotechnology: It's a Small, Small, Small, Small World

    NSDL National Science Digital Library

    Ralph Merkle (Zyvex; )

    2000-04-01

    The issue-focused, peer-reviewed article demonstrates how nanotechnology, or the rearrangement of atoms to manufacture products, has incredible potential. For example: computers with massive memory but miniscule storage devices, airplanes and other transport made from lightweight material, and medical instruments that can operate on cells or genes.

  13. Self-Consistent Model of Magnetospheric Ring Current and Propagating Electromagnetic Ion Cyclotron Waves: Waves in Multi-Ion Magnetosphere

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    The further development of a self-consistent theoretical model of interacting ring current ions and electromagnetic ion cyclotron waves (Khazanov et al., 2003) is presented In order to adequately take into account wave propagation and refraction in a multi-ion magnetosphere, we explicitly include the ray tracing equations in our previous self-consistent model and use the general form of the wave kinetic equation. This is a major new feature of the present model and, to the best of our knowledge, the ray tracing equations for the first time are explicitly employed on a global magnetospheric scale in order to self-consistently simulate the spatial, temporal, and spectral evolution of the ring current and of electromagnetic ion cyclotron waves To demonstrate the effects of EMIC wave propagation and refraction on the wave energy distribution and evolution, we simulate the May 1998 storm. The main findings of our simulation can be summarized as follows. First, owing to the density gradient at the plasmapause, the net wave refraction is suppressed, and He+-mode grows preferably at the plasmapause. This result is in total agreement with previous ray tracing studies and is very clearly found in presented B field spectrograms. Second, comparison of global wave distributions with the results from another ring current model (Kozyra et al., 1997) reveals that this new model provides more intense and more highly plasmapause-organized wave distributions during the May 1998 storm period Finally, it is found that He(+)-mode energy distributions are not Gaussian distributions and most important that wave energy can occupy not only the region of generation, i.e., the region of small wave normal angles, but all wave normal angles, including those to near 90 . The latter is extremely crucial for energy transfer to thermal plasmaspheric electrons by resonant Landau damping and subsequent downward heat transport and excitation of stable auroral red arcs.

  14. Self-Consistent Model of Magnetospheric Ring Current and Propagating Electromagnetic Ion Cyclotron Waves. 1; Waves in Multi Ion Magnetosphere

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    The further development of a self-consistent theoretical model of interacting ring current ions and electromagnetic ion cyclotron waves [Khazanov et al., 2003] is presented. In order to adequately take into account the wave propagation and refraction in a multi-ion plasmasphere, we explicitly include the ray tracing equations in our previous self-consistent model and use the general form of the wave kinetic equation. This is a major new feature of the present model and, to the best of our knowledge, the ray tracing equations for the first time are explicitly employed on a global magnetospheric scale in order to self-consistently simulate spatial, temporal, and spectral evolutions of the ring current and electromagnetic ion cyclotron waves. To demonstrate the effects of EMIC wave propagation and refraction on the EMIC wave energy distributions and evolution we simulate the May 1998 storm. The main findings of our simulation can be summarized as follows. First, due to the density gradient at the plasmapause, the net wave refraction is suppressed, and He(+)-mode grows preferably at plasmapause. This result is in a total agreement with the previous ray tracing studies, and very clear observed in presented B-field spectrograms. Second, comparison the global wave distributions with the results from other ring current model [Kozyra et al., 1997] reveals that our model provides more intense and higher plasmapause organized distributions during the May, 1998 storm period. Finally, the found He(+)-mode energy distributions are not Gaussian distributions, and most important that wave energy can occupy not only the region of generation, i. e. the region of small wave normal angles, but the entire wave normal angle region and even only the region near 90 degrees. The latter is extremely crucial for energy transfer to thermal plasmaspheric electrons by resonant Landau damping, and subsequent downward heat transport and excitation of stable auroral red arcs.

  15. SUPPRESSION OF TEARING MODES BY MEANS OF LOCALIZED ELECTRON CYCLOTRON CURRENT DRIVE IN THE DIII-D TOKAMAK

    SciTech Connect

    T.C. LUCE; R.J. LaHAYE; D.A.HUMPHREYS; C.C. PETTY; R. PRATER; M.E. AUSTIN; D.P. BRENNAN; I.A. GORELOV; J.M. LOHR; F.W. PERKINS; P.A. POLITZER; M.R. WADE

    2002-07-01

    The onset of tearing modes and the resulting negative effects on plasma performance set significant limits on the operational domain of tokamaks. Modes with toroidal mode number (n) larger than two cause only a minor reduction in energy confinement (<10%). Modes which have a dominant poloidal mode number (m) of three and n=2 lead to a significant reduction in confinement (<30%) at fixed power. The plasma pressure {beta} (normalized to the magnetic field pressure) can be raised further, albeit with very small incremental confinement. Pushing to higher {beta} often destabilizes the m=2/n=1 tearing mode which can lock to the wall and lead to a complete and rapid disruption of the plasma with potentially serious consequences for the tokamak. The {beta} values at which these modes usually appear in conventional tokamak discharges are well below the limits calculated using ideal MHD theory. Therefore, the tearing modes can set effective upper limits on energy confinement and pressure. Significant progress has been made in stabilizing these modes by local current generation using electron cyclotron waves. The tearing mode is essentially a deficit in current flowing helically, resonant with the spatial structure of the local magnetic field. This forms an ''island'' where the magnetic flux is no longer monotonic. It was predicted theoretically [1,2] that replacement of this ''missing'' current would return the plasma to the state prior to the instability. Experiments on the ASDEX-Upgrade [3], JT-60U [4], and DIII-D [5] tokamaks have demonstrated stabilization of m=3/n=2 modes using electron cyclotron current drive (ECCD) to replace the current in the island. Following these initial experiments, recent work on the DIII-D tokamak has demonstrated two significant advances in application of this technique--extending the operational domain stable to m=3/n=2 modes to higher {beta} and the first suppression of the more dangerous m=2/n=1 mode.

  16. High-resolution kinetic simulations of electron cyclotron heating

    NASA Astrophysics Data System (ADS)

    Krivenski, Vladimir

    1999-09-01

    A parallel solver of the Fokker-Planck equation, coupled with a set of parallel interpretative codes (computing the Electron Cyclotron Emission, X-Ray Emission, and Thomson Scattering spectra for an arbitrary electron distribution function), was written. The code allows the computation of the electron distribution function at much higher resolution in phase-space than it was previously possible. We find this capability to be crucial when simulating ECH in high-performance plasmas. In such plasmas and for normal heating, strong wave damping causes the RF power to be absorbed by the bulk of the distribution function, with negligible production of suprathermal electrons. Strong bulk absorption, however, is associated with the appearance of a new phenomenon: the deformation of the electron distribution at thermal energies. For power deposition near the plasma center, this effect results in the apparent peaking of the central electron temperature (in addition to the temperature increase), and in the discrepancy among the values of the electron temperature measured by different diagnostics (ECE, XRE, TS), reflecting the different energy-range sensitivity of the diagnostics, and the strong energy-dependence of the slope of the bulk distribution function. The deformation of the bulk distribution is governed by a power-density threshold, and increases with the electron temperature.

  17. ATLAS 10 GHz electron cyclotron resonance ion source upgrade project

    NASA Astrophysics Data System (ADS)

    Moehs, D. P.; Vondrasek, R.; Pardo, R. C.; Xie, D.

    2000-02-01

    A major upgrade of the first ATLAS 10 GHz electron cyclotron resonance (ECR) ion source, which began operations in 1987, is in the planning and procurement phase. The new design will convert the old two-stage source into a single-stage source with an electron donor disk and high gradient magnetic field that preserves radial access for solid material feeds and pumping of the plasma chamber. The new magnetic-field profile allows for the possibility of a second ECR zone at a frequency of 14 GHz. An open hexapole configuration, using a high-energy-product Nd-Fe-B magnet material, having an inner diameter of 8.8 cm and pole gaps of 2.4 cm, has been adopted. Models indicate that the field strengths at the chamber wall, 4 cm in radius, will be 9.3 kG along the magnet poles and 5.6 kG along the pole gaps. The individual magnet bars will be housed in austenitic stainless steel, allowing the magnet housing within the aluminum plasma chamber to be used as a water channel for direct cooling of the magnets. Eight solenoid coils from the existing ECR will be enclosed in an iron yoke to produce the axial mirror. Based on a current of 500 A, the final model predicts a minimum B field of 3 kG with injection and extraction mirror ratios of 4.4 and 2.9, respectively.

  18. Probing layer localization in twisted graphene bilayers via cyclotron resonance

    NASA Astrophysics Data System (ADS)

    Lu, Chi-Ken; Fertig, H. A.

    2015-03-01

    Electron wave functions in twisted bilayer graphene may have a strong single-layer character or be intrinsically delocalized between layers, with their nature often determined by how energetically close they are to the Dirac point. We demonstrate that in magnetic fields, cyclotron resonance spectra contain signatures that may be used to distinguish the nature of these wave functions at low energies, as well as to locate low-energy critical points in the zero-field energy spectrum. Optical absorption for two different configurations-electric field parallel and perpendicular to the bilayer-is calculated, and the configurations are shown to have different selection rules with respect to which states are connected by the perturbation. Interlayer bias further distinguishes transitions involving states of a single-layer nature from those with support in both layers. For doped systems, a sharp increase in intra-Landau-level absorption occurs with increasing field as the level passes through the zero-field saddle-point energy, where the states change character from single layer to bilayer. The effects of impurity scattering will be discussed too. This work was supported by the NSF through Grant No. DMR-1005035, the U.S.-Israel Binational Science Foundation, and Ministry of Science and Technology Taiwan Grant No. 103-2112-M-003-012-MY3.

  19. Mapping Quantized Cyclotron Orbits of Dirac Particles in Graphene

    NASA Astrophysics Data System (ADS)

    Miller, David; Kubista, Kevin; Ruan, Ming; de Heer, Walt; First, Phil; Rutter, Gregory; Stroscio, Joseph

    2009-11-01

    Monolayer graphene has unique electronic properties stemming from a low-energy band structure that is linear near the charge neutrality point (Dirac point). In a magnetic field, cyclotron orbits of electrons and holes are quantized into ``Landau levels'' (LL), with energies En that vary proportional to ?nB, where n is the LL quantum number. The Dirac physics of this system provides an interesting opportunity for experiments in scanning tunneling microscopy (STM) and spectroscopy (STS). We present results from STM/STS measurements of the local density of states (LDOS) of graphene grown epitaxially on SiC (000-1). The sample was studied at 4.3K in ultra-high vacuum under an applied perpendicular magnetic field <= 8T. Using STS maps, we observed the LDOS over a 100 nm^2 area at energies within ±200meV of the Dirac point. We find transitions from localized to extended states as the LDOS energy progresses across Landau levels. The zero-energy Landau level--unique to graphene--is observed to shift and split in areas where localized states occur. Results from Landau levels of different quantum numbers are also presented for comparison. Work supported in part by NSF, NRI-INDEX, and the W. M. Keck Foundation.

  20. Seventh Harmonic Co-Generation by Cyclotron Resonance Acceleration

    NASA Astrophysics Data System (ADS)

    Wang, Changbiao; Hirshfield, J. L.; Ganguly, Achintya K.

    1997-05-01

    The TE_72 mode in cylindrical waveguide has group velocity nearly equal to that of the TE_11 mode if the operating frequency of TE_72 is seven times of that of TE_11.(C. Wang, J. L. Hirshfield, and A. K. Ganguly, Phys. Rev. Lett. 77), 3819 (1996). This allows coherent radiation to be generated at the seventh harmonic while the TE_11 mode interacts with an electron beam via cyclotron autoresonance.(C. Wang and J. L. Hirshfield, Phys. Rev. E 51), 2456 (1995); M. A. LaPointe, R. B. Yoder, C. Wang, A. K. Ganguly, and J. L. Hirshfield, Phys. Rev. Lett. 76, 2718 (1996). For a 300 kV, 30 A warm beam pumped by 20 MW rf power at 2.856 GHz, simulations indicate that careful choice of the magnetic field profile and suppression of TE_11 mode after it is completely depleted can increase the seventh harmonic output up to 10 MW at 20 GHz. It is furthermore shown that injection can also benefit co-generation, both increasing harmonic output up to 16 MW and improving spent beam quality, which is helpful to beam energy recovery for efficiency enhancement.

  1. Electromagnetic ion-cyclotron instability in space plasmas

    SciTech Connect

    Xue, S.; Thorne, R.M. [Univ. of California, Los Angeles, CA (United States); Summers, D. [Memorial Univ. of Newfoundland, St. John`s, Newfoundland (Canada)

    1993-10-01

    Natural space plasmas generally exhibit a pronounced high-energy tail distribution that can best be modeled by a generalized Lorentzian (kappa) distribution. The authors employ the recently introduced modified plasma dispersion function to obtain the dispersion relation for field-aligned electromagnetic waves in such a plasma, and use this to study the instability properties of R mode and L mode waves in the solar wind and in planetary magnetospheres. They demonstrate for a wide range of plasma parameters that the growth of R mode waves in the solar wind can be significantly enhanced by the presence of a pronounced high-energy tail; previous studies based on a Maxwellian distribution could therefore be seriously in error. The corresponding enhancement in the growth rate of L mode waves in planetary magnetospheres is less dramatic, but the kappa distribution tends to produce significant wave amplification over a broader range of frequency than a Maxwellian distribution with comparable bulk properties. At frequencies comparable to the ion gyrofrequency wave growth is primarily caused by cyclotron resonance with ions. Hot anisotropic electrons can nevertheless influence the instability as a result of changes in the wave phase velocity. This modulating effect is most important for a Maxwellian plasma and becomes less significant as the spectral index of the kappa distribution is reduced. 15 refs., 11 figs.

  2. Cyclotron accelerated beams applied in wear and corrosion studies

    NASA Astrophysics Data System (ADS)

    Racolta, P. M.; Popa-Simil, L.; Ivanov, E. A.; Alexandreanu, B.

    1996-05-01

    Wear and corrosion processes are characterized by a loss of material that is, for machine parts and components, usually in a micrometer's range. That is why, in the last two decades, many direct applications in machine construction, petrochemical and metallurgical industries based on the Thin Layer Activation (TLA) technique have been developed. In this paper general working patterns together with a few examples of TLA applications carried out using our laboratory's U-120 Cyclotron are presented. The relation between the counting rate of the radiation originating from the component's irradiated zone and the loss of the worn material can be determined mainly by two methods: the oil circulation method and the remnant radioactivity measuring method. The first method is illustrated with some typical examples such as the optimization of the running-in program of a diesel engine and anti-wear features certifying of lubricant oils. There is also presented an example where the second method mentioned above has been applied to corrosion rate determinations for different kinds of unoxidable steels used in inert gas generator construction.

  3. Electron-cyclotron maser emission during solar and stellar flares

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.

    1985-01-01

    Radio bursts, with high brightness temperature 10 to the 10th power K and high degree of polarization, and the heating of the solar and stellar coronae during flares have been attributed to emission from the semirelativistic maser instability. In plasmas where the electron-plasma frequency, p, omega sub p, and the electron-cyclotron frequency, Omega sub e, are such that omega sup 2 sub p/Omega sup 2 sub e 1, x-mode growth dominates while z-mode growth dominates if omega sup 2 sub p/Omega sup 2 sub e is of order unity. The actual value of omega sup 2 sub p/Omega sup 2 sub e at which x-mode growth dominates is shown to be dependent on the plasma temperature with x-mode growth dominating at higher omega sub p/Omega sub e as the plasma temperature increases. Observations from a set of 20 impulsive flares indicate that the derived conditions for the dominance of x-mode growth are satisfied in about 75 percent of the flares.

  4. Electron-cyclotron maser emission during solar and stellar flares

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.

    1985-01-01

    Radio bursts, with high brightness temperature 10 to the 10th power K and high degree of polarization, and the heating of the solar and stellar coronae during flares have been attributed to emission from the semirelativistic maser instability. In plasmas where the electron-plasma frequency, p, omega sub p, and the electron-cyclotron frequency, Omega sub e, are such that omego sup 2 sub p/Omega sup 2 sub e 1, x-mode growth dominates while z-mode growth dominates if omega sup 2 sub p/Omega sup 2 sub e at which x-mode growth dominates is shown to be dependent on the plasma temperature with x-mode growth dominating at higher omega sub p/Omega sub e as the plasma temperature increases. Observations from a set of 20 impulsive flares indicate that the derived conditions for the dominance of x-mode growth are satisfied in about 75 percent of the flares.

  5. Control System of the Small Isochronous ring

    SciTech Connect

    Felix Marti; Eduard Pozdeyev

    2004-07-01

    The purpose of this paper is to describe the control system of the Small Isochronous Ring (SIR) developed and built at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). SIR is a small-scale experiment that simulates the dynamics of intense beams in large accelerators. A 20 to 30 keV hydrogen or deuterium ion bunch is injected in the ring, extracted after a variable number of turns and its longitudinal profile is studied. Information about the electronics used and software written to control different injection line, ring and extraction line elements is included. Some of these elements are magnets, electrostatic quadrupoles, electric and magnetic correctors, scanning wires, emittance measurement system, chopper and a fast Faraday cup.

  6. Beam Diagnostics of the Small Isochronous Ring

    SciTech Connect

    Felix Marti; Eduard Pozdeyev

    2004-07-01

    The purpose of this paper is to describe the beam diagnostic systems in the Small Isochronous Ring (SIR) developed and built at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). SIR is a small-scale experiment that simulates the dynamics of intense beams in large accelerators. A 20 to 30 keV hydrogen or deuterium ion bunch is injected in the ring, extracted after a variable number of turns and its longitudinal profile is studied. Some of the diagnostic tools available in SIR include an emittance measurement system in the injection line, scanning wires in different sections of the ring, phosphor screens at the injection and extraction points and a fast Faraday cup in the extraction line. The design of these systems and the kind of beam information they provide are discussed in detail.

  7. Medical imaging.

    PubMed Central

    Kreel, L.

    1991-01-01

    There is now a wide choice of medical imaging to show both focal and diffuse pathologies in various organs. Conventional radiology with plain films, fluoroscopy and contrast medium have many advantages, being readily available with low-cost apparatus and a familiarity that almost leads to contempt. The use of plain films in chest disease and in trauma does not need emphasizing, yet there are still too many occasions when the answer obtainable from a plain radiograph has not been available. The film may have been mislaid, or the examination was not requested, or the radiograph had been misinterpreted. The converse is also quite common. Examinations are performed that add nothing to patient management, such as skull films when CT will in any case be requested or views of the internal auditory meatus and heal pad thickness in acromegaly, to quote some examples. Other issues are more complicated. Should the patient who clinically has gall-bladder disease have more than a plain film that shows gall-stones? If the answer is yes, then why request a plain film if sonography will in any case be required to 'exclude' other pathologies especially of the liver or pancreas? But then should cholecystography, CT or scintigraphy be added for confirmation? Quite clearly there will be individual circumstances to indicate further imaging after sonography but in the vast majority of patients little or no extra information will be added. Statistics on accuracy and specificity will, in the case of gall-bladder pathology, vary widely if adenomyomatosis is considered by some to be a cause of symptoms or if sonographic examinations 'after fatty meals' are performed. The arguments for or against routine contrast urography rather than sonography are similar but the possibility of contrast reactions and the need to limit ionizing radiation must be borne in mind. These diagnostic strategies are also being influenced by their cost and availability; purely pragmatic considerations are not infrequently the overriding factor. Non-invasive methods will be preferred, particularly sonography as it is far more acceptable by not being claustrophobic and totally free of any known untoward effects. There is another quite different but unrelated aspect. The imaging methods, apart from limited exceptions, cannot characterize tissues as benign or malignant, granulomatous or neoplastic; cytology or histology usually provides the answer. Sonography is most commonly used to locate the needle tip correctly for percutaneous sampling of tissues. Frequently sonography with fine needle aspiration cytology or biopsy is the least expensive, safest and most direct route to a definitive diagnosis. Abscesses can be similarly diagnosed but with needles or catheters through which the pus can be drained. The versatility and mobility of sonography has spawned other uses, particularly for the very ill and immobile, for the intensive therapy units and for the operating theatre, as well in endosonography. The appointment of more skilled sonographers to the National Health Service could make a substantial contribution to cost-effective management of hospital services. Just when contrast agents and angiography have become safe and are performed rapidly, they are being supplanted by scanning methods. They are now mainly used for interventional procedures or of pre-operative 'road maps' and may be required even less in the future as MRI angiography and Doppler techniques progress. MRI will almost certainly extent its role beyond the central nervous system (CNS) should the equipment become more freely available, especially to orthopaedics. Until then plain films, sonography or CT will have to suffice. Even in the CNS there are conditions where CT is more diagnostic, as in showing calculations in cerebral cysticercosis. Then, too, in most cases CT produces results comparable to MRI apart from areas close to bone, structures at the base of the brain, in the posterior fossa and in the spinal cord. Scintigraphy for pulmonary infarcts and bone metastases and in renal disease in children plays

  8. Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

    SciTech Connect

    Falabella, S.

    1988-05-11

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10/sup 12/cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an increase in ion temperature from near 20 eV before ICRH to near 150 eV during ICRH, with about 60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial intergral of n/sub i/T/sub i/ as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma is seen to vary from axially peaked, to nearly flat as the plasma conditions carried over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U. 62 refs., 63 figs., 7 tabs.

  9. Study of the substrate bias in plasma depositions using an electron cyclotron resonance plasma

    SciTech Connect

    Shirai, K.; Gonda, S. (The Institute of Scientific and Industrial Research, Osaka University, 8-1, Mihogaoka, Ibaraki, Osaka 567 (Japan))

    1990-10-15

    A variety of effects of substrate bias upon an electron cyclotron resonance plasma deposition have been studied, taking the deposition of amorphous boron carbide films as an example. First, the impact energy of ions incident on substrates was studied through the variation of the sheath potentials formed on insulating and conducting substrates. For this purpose, the plasma potential ({ital V}{sub {ital p}}) was measured by the bias current-voltage ({ital I}{sub {ital b}}-{ital V}{sub {ital b}}) analysis, and the floating potential ({ital V}{sub {ital f}}) was measured by the Langmuir probe method. These analyses show that the plasma potential is sufficiently influenced by the substrate bias for positive biases even if the area of the bias electrode is small. The energy of ions incident on conducting substrates is not effectively changed by imposing a positive bias. This effect can be explained in terms of the global balance of the electron and ion currents. This consideration leads to the criterion for the area of bias electrode at which the substrate bias perturbs the plasma potential. Next, the effects of the substrate bias upon the deposition processes and properties of the deposited films were studied through the variations of the deposition rates and the infrared absorption due to the atomic vibrations in the films. The deposition rates vary with the substrate bias according to the variation of sheath potentials: {ital V}{sub {ital p}}{minus}{ital V}{sub {ital f}} for insulating substrates and {ital V}{sub {ital p}}{minus}{ital V}{sub {ital b}} for conducting substrates. As the substrate bias increases negatively, the deposition rate on conducting substrates increases. This increase is hardly explained by the direct contribution of ions to the deposition.

  10. A quasi-optical electron cyclotron maser for fusion reactor heating. Final report

    SciTech Connect

    Morse, E.C.

    1990-12-31

    High power microwave and millimeter sources, such as the quasi-optical electron cyclotron maser (QOECM) are important in fusion research as well as in high-energy physics and in other applications. The interaction between the electromagnetic modes of a Fabry-Perot resonator and an electron beam gyrating through a magnetic field has been studied for both the cases of beams parallel and perpendicular to the resonator. The parallel case was theoretically first studied by Kurin for forward and backward wave interaction, and experimentally by Komlev and Kurin. Kreischer and Temkin reviewed the general case of the linear small signal interaction parallel and perpendicular to the resonator. Sprangle, et al discussed the perpendicular case in a self-consistent linear and nonlinear theoretical study using the Gaussian transverse profile of an open resonator with a single longitudinal mode. Experimental verification of the devices operation was first mentioned in work at the Naval Research Laboratory. Theoretical studies using a time-dependent analysis of a large number of longitudinal modes with similar transverse mode profiles have demonstrated that single longitudinal-mode operation can be achieved at equilibrium and that performance can be enhanced by prebunching the electron beam and tapering the magnetic field. The use of output coupling apertures in the mirrors has been studied theoretically in relation to the structure of the modes for both confocal and nonconfocal resonators by Permnoud; use of an open resonator with stepped mirrors has been studied in order to choose a particular longitudinal mode. Studies at the Naval Research Laboratory mirror used configurations that diffraction couple the energy from around the mirror edges, so that the transverse profile inside the resonator can be selective to the fundamental mode.

  11. The Medical Passport

    ERIC Educational Resources Information Center

    Ineson, Sue; Seeling, Stephen S.

    2005-01-01

    A Working Group on Medical Passports was established in 2002 by the International Association of Medical Regulatory Authorities. The goal of this group was to develop a fast-track registration process for highly qualified medical practitioners wishing to move from one jurisdiction to another. A "medical passport" would be available only to…

  12. Medicine and Medical Center

    E-print Network

    Faculty of Medicine and Medical Center (FM/AUBMC) #12;400 Faculty of Medicine and Medical Center (FM/AUBMC) Graduate Catalogue 2014­15 Faculty of Medicine and Medical Center (FM/AUBMC) Officers Vice President for Medical Affairs and the Raja N. Khuri Dean of the Faculty of Medicine Ziyad Ghazzal

  13. Medicine and Medical Center

    E-print Network

    Shihadeh, Alan

    Faculty of Medicine and Medical Center (FM/AUBMC) #12;370 Faculty of Medicine and Medical Center (FM/AUBMC) Graduate Catalogue 2013­14 Faculty of Medicine and Medical Center (FM/AUBMC) Officers Vice President for Medical Affairs and the Raja N. Khuri Dean of the Faculty of Medicine Ziyad Ghazzal

  14. GOOD MEDICAL PRACTICE

    Microsoft Academic Search

    Kerry J Breen; MB BS; Stephen M Cordner; Dip Crim

    Good Medical Practice: Professionalism, Ethics and Law brings together the infor- mation central to the professional, ethical and legal requirements of being a doctor. It covers a core curriculum for medical students, doctors in training and international medical graduates preparing for the Australian Medical Council examinations. It will also be useful for busy doctors looking for answers to issues that

  15. Ion beam driven resonant ion-cyclotron instability in a magnetized dusty plasma

    NASA Astrophysics Data System (ADS)

    Prakash, Ved; Sharma, Suresh C.; Vijayshri, Gupta, Ruby

    2014-03-01

    Electrostatic ion cyclotron waves are excited by axial ion beam in a dusty plasma via Cerenkov and slow cyclotron interaction. The dispersion relation of the instability is derived in the presence of positively/negatively charged dust grains. The minimum beam velocity needed for the excitation is estimated for different values of relative density of negatively charged dust grains. It is shown that the minimum beam velocity needed for excitation increases as the charge density carried by dust increases. Temperature of electrons and ions, charge and mass of dust grains, external static magnetic field and finite boundary of dusty plasma significantly modify the dispersion properties of these waves and play a crucial role in the growth of resonant ion cyclotron instability. The ion cyclotron modes with phase velocity comparable to the beam velocity possess a large growth rate. The maximum value of growth rate increases with the beam density and scales as the one-third power of the beam density in Cerenkov interaction and is proportional to the square root of beam density in slow cyclotron interaction.

  16. Ion beam driven resonant ion-cyclotron instability in a magnetized dusty plasma

    SciTech Connect

    Prakash, Ved; Vijayshri [School of Sciences, Indira Gandhi National Open University, Maidan Garhi, New Delhi 110 068 (India)] [School of Sciences, Indira Gandhi National Open University, Maidan Garhi, New Delhi 110 068 (India); Sharma, Suresh C. [Department of Applied Physics, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi 110 042 (India)] [Department of Applied Physics, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi 110 042 (India); Gupta, Ruby [Department of Physics, Swami Shraddhanand College, University of Delhi, Alipur, Delhi 110 036 (India)] [Department of Physics, Swami Shraddhanand College, University of Delhi, Alipur, Delhi 110 036 (India)

    2014-03-15

    Electrostatic ion cyclotron waves are excited by axial ion beam in a dusty plasma via Cerenkov and slow cyclotron interaction. The dispersion relation of the instability is derived in the presence of positively/negatively charged dust grains. The minimum beam velocity needed for the excitation is estimated for different values of relative density of negatively charged dust grains. It is shown that the minimum beam velocity needed for excitation increases as the charge density carried by dust increases. Temperature of electrons and ions, charge and mass of dust grains, external static magnetic field and finite boundary of dusty plasma significantly modify the dispersion properties of these waves and play a crucial role in the growth of resonant ion cyclotron instability. The ion cyclotron modes with phase velocity comparable to the beam velocity possess a large growth rate. The maximum value of growth rate increases with the beam density and scales as the one-third power of the beam density in Cerenkov interaction and is proportional to the square root of beam density in slow cyclotron interaction.

  17. SELF-CONSISTENT ION CYCLOTRON ANISOTROPY-BETA RELATION FOR SOLAR WIND PROTONS

    SciTech Connect

    Isenberg, Philip A. [Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824 (United States); Maruca, Bennett A. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Kasper, Justin C., E-mail: phil.isenberg@unh.edu, E-mail: bmaruca@ssl.berkeley.edu, E-mail: jkasper@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2013-08-20

    We derive a set of self-consistent marginally stable states for a system of ion-cyclotron waves propagating parallel to the large-scale magnetic field through a homogeneous proton-electron plasma. The proton distributions and the wave dispersions are related through the condition that no further ion-cyclotron resonant particle scattering or wave growth/damping may take place. The thermal anisotropy of the protons in these states therefore defines the threshold value for triggering the proton-cyclotron anisotropy instability. A number of recent papers have noted that the anisotropy of solar wind protons at 1 AU does not seem to be limited by the proton-cyclotron anisotropy threshold, even at low plasma beta. However, this puzzle seems to be due solely to the estimation of this anisotropy threshold under the assumption that the protons have a bi-Maxwellian distribution. We note that bi-Maxwellian distributions are never marginally stable to the resonant cyclotron interaction, so these estimates do not represent physically valid thresholds. The threshold anisotropies obtained from our marginally stable states are much larger, as a function of proton parallel beta, than the bi-Maxwellian estimates, and we show that the measured data remains below these more rigorous thresholds. Thus, the results of this paper resolve the apparent contradiction presented by the solar wind anisotropy observations at 1 AU: the bi-Maxwellian anisotropies are not rigorous thresholds, and so do not limit the proton distributions in the solar wind.

  18. The cyclotron spectrum of anisotropic ultrarelativistic electrons: interpretation of X-ray pulsar spectra

    E-print Network

    A. N. Baushev

    2008-04-10

    The spectrum of cyclotron radiation produced by electrons with a strongly anisotropic velocity distribution is calculated taking into account higher harmonics. The motion of the electrons is assumed to be ultrarelativistic along the magnetic field and nonrelativistic across the field. One characteristic feature of the resulting spectrum is that harmonics of various orders are not equally spaced. The physical properties and observed spectra of four X-ray pulsars displaying higher cyclotron harmonics are analyzed. The cyclotron features in the spectra of all four pulsars can be interpreted only as emission lines. Moreover, the observed harmonics are not equidistant, and display certain other properties characteristic of emission by strongly anisotropic ultrarelativistic electrons. In addition, there are indirect theoretical arguments that the electrons giving rise to cyclotron features in the spectra of X-ray pulsars are ultrarelativistic and characterized by strongly anisotropic distributions. As a result, estimates of the magnetic fields of X-ray pulsars (which are usually derived from the energies of cyclotron lines) and certain other physical parameters require substantial revision.

  19. STS-3 medical report

    NASA Technical Reports Server (NTRS)

    Pool, S. L. (editor); Johnson, P. C., Jr. (editor); Mason, J. A. (editor)

    1982-01-01

    The medical operations report for STS-3, which includes a review of the health of the crew before, during, and immediately after the third Shuttle orbital flight is presented. Areas reviewed include: health evaluation, medical debriefing of crewmembers, health stabilization program, medical training, medical 'kit' carried in flight, tests and countermeasures for space motion sickness, cardiovascular profile, biochemistry and endocrinology results, hematology and immunology analyses, medical microbiology, food and nutrition, potable water, shuttle toxicology, radiological health, and cabin acoustic noise. Environmental effects of shuttle launch and landing medical information management, and management, planning, and implementation of the medical program are also dicussed.

  20. Measurements of ion cyclotron range of frequencies mode converted wave intensity with phase contrast imaging in Alcator C-Mod and comparison with full-wave simulations

    E-print Network

    Jaeger, E. F.

    Radio frequency waves in the ion cyclotron range of frequencies (ICRF) are widely used to heat tokamak plasmas. In ICRF heating schemes involving multiple ion species, the launched fast waves convert to ion cyclotron waves ...