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1

Cyclotron Production of Medical Radionuclides  

NASA Astrophysics Data System (ADS)

Cyclotron products are gaining in significance in diagnostic investigations via PET and SPECT, as well as in some therapeutic studies. The scientific and technological background of radionuclide production using a cyclotron is briefly discussed. Production methods of the commonly used positron and photon emitters are described and developments in the production of some new positron emitters and therapeutic radionuclides outlined. Some perspectives of cyclotron production of medical radionuclides are considered.

Qaim, S. M.

2

BEST medical radioisotope production cyclotrons  

NASA Astrophysics Data System (ADS)

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].

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

2013-04-01

3

[Evaluation of Radio-activated Compounds Produced in the Walls and Adjacent Areas of a Small Medical Cyclotron].  

PubMed

According to the (18)O(p, n) (18)F reaction, fast neutrons produced in the target will cause residual radioactivity in a cyclotron itself and in the concrete walls mainly after thermalization of neutrons.As exploratory work prior to decommissioning of a medical cyclotron facility, surface and core samples of the facility's concrete walls were collected after confirming the external radiation was at a low level based on hollow ionization chamber-type survey meter and glass dosimeter measurements. The residual radioactivity in these samples was measured by gamma-spectrometry. Residual radioactivity was detected in all of the components of the cyclotron. In the concrete, eight residual radioactive nuclides were identified. However, radioactivity concentrations of these radionuclides were less than that of (40)K which may exist generally in a natural environment. A clearance level for radioactive solid waste has not been defined nor implemented at present in Japan, and reliable evaluation will be required to minimize radioactive waste at the time of decommissioning. The present results provide basic data for establishment of regulatory guidelines for decommissioning of medical cyclotrons. PMID:21979783

Saito, Kyoko; Takahashi, Yasuyuki; Yamaguchi, Ichiro; Kimura, Ken-Ichi; Kanzaki, Takao; Shimada, Hirotaka; Otake, Hidenori; Oriuchi, Noboru; Endo, Keigo

2009-01-01

4

National Medical Cyclotron Facility: Report to the Minister of Health by the Medical Cyclotron Committee.  

National Technical Information Service (NTIS)

Research and training in nuclear medicine in Australia are both limited by the lack of a medical cyclotron facility. The Committee recommends the establishment of a national medical cyclotron to provide a supply of short-lived radioisotopes for research i...

1985-01-01

5

Development of a Medical Cyclotron Production Facility  

NASA Astrophysics Data System (ADS)

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.

Allen, Danny R.

2003-08-01

6

Development of a Medical Cyclotron Production Facility  

SciTech Connect

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.

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

2003-08-26

7

Rotatable superconducting cyclotron adapted for medical use  

DOEpatents

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

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

1985-01-01

8

Development of a Medical Cyclotron Production Facility  

Microsoft Academic Search

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

Danny R. Allen; Danny R

2003-01-01

9

A Small Helium3 Cyclotron  

Microsoft Academic Search

A 27-inch AVF cyclotron of fourfold symmetry designed specifically for use in helium-3 activation analysis is now in operation at the Lawrence Radiation Laboratory in Berkeley. The fixed energy and modest beam quality requirements have resulted in an instrument of minimum size, weight, power consumption, and fabrication costs. New techniques were developed to construct edge-cooled tape-wound magnet coils which are

R. M. Main; M. R. Curtis; R. Grazier; P. B. Kennedy; B. H. Smith; D. A. Spence

1967-01-01

10

a Small Low-Energy Cyclotron for Radioisotope Measurements  

Microsoft Academic Search

Direct detection of ^{14} C by accelerator mass spectrometry has proved to be a much more sensitive method for radiocarbon dating than the decay counting method invented earlier by Libby. A small cyclotron (the \\

Kirk Joseph Bertsche

1989-01-01

11

Ion motion in a small low energy cyclotron  

NASA Astrophysics Data System (ADS)

A small cyclotron (the ``cyclotrino'') was proposed for direct detection of radiocarbon in 1980 and has now detected radiocarbon at natural abundance. High resolution and background rejection are achieved in this cyclotron by acceleration of negative ions through many turns while operating at a high harmonic. This article details the analysis of ion motion in a small flat-field, electrostatically-focused cyclotron. Included are discussions of beam acceptance, axial and radial beam stability, and a detailed analysis of phase bunching and its effect on mass resolution. Present address: Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, P.O. Box 808, L-397, Livermore, CA 94551, USA.

Bertsche, Kirk J.

1991-03-01

12

A compact cyclotron C-30 for medical isotopes production  

SciTech Connect

The isochronous cyclotron C-30 with pole diameter 105 cm accelerates H/sup -/ particles up to 31 MeV or D/sup -/ to 16 MeV with intensities about 50 uA. The protons or deutrons extracted by stripping will be used for medical isotopes production.

Sura, J.; Getku, S.; Plawski, E.; Weychert, C.; Zuwadzki, J.

1985-10-01

13

The present situation and the prospect of medical cyclotrons in China  

NASA Astrophysics Data System (ADS)

The paper introduces the increasing applications of cyclotrons in the field of health care and some major work carried out abroad. Its emphasis is placed on the introduction to the application status and the development process of medical cyclotrons in China. The paper has assessed possible developing trends of medical cyclotrons based on the current application demand and the technological development status.

Zhang, TianJue; Fan, MingWu; Wei, SuMin; Chen, ShengZu; Yang, Fang

2011-12-01

14

An advanced PC-PLC-based SCADA system for a commerical medical cyclotron  

Microsoft Academic Search

A novel SCADA system is developed for the 30 MeV H? ion commercial Medical Cyclotron (Model: Cyclone-30) operating at proton beam currents up to 850 ?A, at the National Medical Cyclotron, Sydney Australia. Cyclone-30 control system at NMC consists of two PLCs and a PC. The NMC SCADA system is based on a IBM compatible PC and FIX DMACS software

Ramapriyan Singlachar; Bhaskar Mukherjee

1997-01-01

15

A new generation of medical cyclotrons for the 90`s  

SciTech Connect

Cyclotrons continue to be efficient accelerators for use in radio-isotope production. In recent years, developments in accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper the authors will survey recent developments in the areas of cyclotron technology as they relate to the new generation of commercial cyclotrons. Existing and potential markets for these cyclotrons will be presented. They will also discuss the possibility of systems capable of extracted energies up to 150 MeV and extracted beam currents of up to 2.0 mA.

Milton, B.F.

1995-08-01

16

An advanced PC-PLC-based SCADA system for a commercial medical cyclotron  

NASA Astrophysics Data System (ADS)

A novel SCADA system is developed for the 30 MeV H- ion commercial Medical Cyclotron (Model: Cyclone-30) operating at proton beam currents up to 850 ?A, at the National Medical Cyclotron, Sydney Australia. Cyclone-30 control system at NMC consists of two PLCs and a PC. The NMC SCADA system is based on a IBM compatible PC and FIX DMACS software package running on Windows 3.1 platform. This system is custom built for the Cyclone-30 at NMC. High-quality graphic screens are designed to suit the cyclotron at NMC keeping up to date with all the system upgrades. This system is designed to completely replace the existing man-machine interface with many new functions. This paper describes the important components of the system including system architecture and software development.

Singlachar, Ramapriyan; Mukherjee, Bhaskar

1997-02-01

17

Hospital based superconducting cyclotron for neutron therapy: Medical physics perspective  

NASA Astrophysics Data System (ADS)

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

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

2001-12-01

18

Medical Waste Management Implications for Small Medical Facilities.  

ERIC Educational Resources Information Center

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…

Byrns, George; Burke, Thomas

1992-01-01

19

Medical Waste Management Implications for Small Medical Facilities.  

ERIC Educational Resources Information Center

|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…

Byrns, George; Burke, Thomas

1992-01-01

20

Measurement of thermal neutron fluence distribution with use of 23 Na radioactivation around a medical compact cyclotron  

Microsoft Academic Search

A medical compact cyclotron produces about 1015 neutrons per day along with 100 GBq of 18F. Therefore, it is important to establish radiation safety guidelines on residual radioactivity for routine operation, maintenance\\u000a work, and decommissioning. Thus, we developed a simple method for measuring the thermal neutrons in a cyclotron room. In order\\u000a to verify the feasibility of our proposed method, we

Toshioh Fujibuchi; Ichiro Yamaguchi; Tetsuharu Kasahara; Takashi Iimori; Yoshitada Masuda; Ken-ichi Kimura; Hiroshi Watanabe; Tomonori Isobe; Takeji Sakae

2009-01-01

21

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

SciTech Connect

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

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

2013-01-01

22

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

PubMed Central

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.

Pant, G. S.; Senthamizhchelvan, S.

2007-01-01

23

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

24

A real-time positron monitor for the estimation of stack effluent releases from PET medical cyclotron facilities.  

PubMed

Large activities of short-lived positron emitting radiopharmaceuticals are routinely manufactured by modern Medical Cyclotron facilities for positron emission tomography (PET) applications. During radiochemical processing, a substantial fraction of the volatile positron emitting radiopharmaceuticals are released into the atmosphere. An inexpensive, fast response positron detector using a simple positron-annihilation chamber has been developed for real-time assessment of the stack release of positron emitting effluents at the Australian National Medical Cyclotron. The positron detector was calibrated by using a 3.0 ml (1.50 MBq) aliquot of 18FDG and interfaced to an industrial standard datalogger for the real-time acquisition of stack release data. PMID:12406635

Mukherjee, Bhaskar

2002-12-01

25

Selected Reference Aids for Small Medical Libraries *  

PubMed Central

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

Duncan, Howertine Farrell

1970-01-01

26

Reclassification in a small decentralized medical library.  

PubMed

This study describes procedures and indentifies problems in the reclassification of a small medical school library collection that is decentralized into five locations in three different communities. A total of 9,915 monographic titles (14,911 volumes) were reclassified in a nine-month period. The reclassification staff consisted of one professional, two nonprofessionals, and one partime student assistant. PMID:884347

Tong, J G; Brennen, P W; Byrd, G D

1977-07-01

27

Basic Reference Aids for Small Medical Libraries *  

PubMed Central

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

Blair, Edith D.

1967-01-01

28

Cyclotrons: From Science to Human Health  

NASA Astrophysics Data System (ADS)

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

Craddock, Michael

2011-04-01

29

Cyclotron production of [{sup 18}F]fluoride ion and [{sup 18}F]fluorine gas and their medical applications  

SciTech Connect

One of the newest low energy cyclotrons for the production of positron emitting isotopes has been sited at Lawrence Berkeley National Laboratory. This prototype CTI RDS-111, proton only, 11 MeV, negative ion machine is capable of producing GBq quantities of fluorine-18 for radiopharmaceutical applications. A CTI designed target changing system developed for this cyclotron can hold up to eight small targets. We have tested two small high pressure CTI silver body target designs for the production of [{sup 18}F]fluoride ion and compared them to the CTI RDS-112 style low pressure target. The high pressure target can produce up to 100{percent} more activity for a given time and beam current with improved saturation yields. A high pressure aluminum RDS-112 gas target has been used to produce [{sup 18}F]F{sub 2}. The fluoride ion produced from this machine has been used to label fluorodeoxyglucose to trace glucose metabolism in patients and the fluorine gas has been used to label fluoro-meta-tyrosine to image therapeutic response to gene therapy in Parkinsonian monkeys. {copyright} {ital 1997 American Institute of Physics.}

VanBrocklin, H.F.; ONeil, J.P. [Center for Functional Imaging, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

1997-02-01

30

Shielding for a cyclotron used for medical isotope production in China.  

PubMed

Monte Carlo and discrete ordinate calculations have been performed to determine the doses at several locations in a positron emission tomography (PET) facility in China, where the radiation source is a cyclotron that is used for the production of the isotopes necessary for PET scans. The energy-dependent neutron source term is obtained by calculations using the ALICE code, and is interpolated for input to Monte Carlo and discrete ordinate calculations. The building that houses the cyclotron has a labyrinth of walls to minimise dose to operators and to other occupants of the building. Unbiased Monte Carlo calculations did not converge after more than one week of CPU time, whereas direction biasing alone resulted in convergence in several days. A study of several biasing techniques indicated that about a factor of 3 in computational efficiency is obtained using evaluated biasing methods. The use of adjoint fluxes for biasing Monte Carlo calculations can improve computational efficiencies by one or two orders of magnitude for some problems. PMID:16381758

Pevey, R; Miller, L F; Marshall, B J; Townsend, L W; Alvord, B

2005-01-01

31

Automated cyclotron tuning using beam phase measurements  

NASA Astrophysics Data System (ADS)

The ACCEL K250 superconducting cyclotron is specifically designed for the use in proton therapy systems. The compact medical 250 MeV proton accelerator fulfils all present and future beam requirements for fast scanning treatment systems and is delivered as a turn key system; no operator is routinely required. During operation of the cyclotron heat dissipation of the RF system induces a small drift in iron temperature. This temperature drift slightly detunes the magnetic field and small corrections must be made. A non-destructive beam phase detector has been developed to measure and quantify the effect of a magnetic field drift. Signal calculations were made and the design of the capacitive pickup probe was optimised to cover the desired beam current range. Measurements showed a very good agreement with the calculated signals and beam phase can be measured with currents down to 3 nA. The measured phase values are used as input for a feedback loop controlling the current in the superconducting coil. The magnetic field of the cyclotron is tuned automatically and online to maintain a fixed beam phase. Extraction efficiency is thereby optimised continuously and activation of the cyclotron is minimised. The energy and position stability of the extracted beam are well within specification.

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

2006-12-01

32

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

PubMed

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

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

2013-01-11

33

Cyclotrons: 1978  

SciTech Connect

A compilation is presented of the experimental facilities of the world's cyclotrons including history and status, staff and operation, research staff, target facilities, magnet, acceleration system, vacuum system, characteristic beams, beam properties, and a plan view of the facility for each cyclotron. (GHT)

Martin, J.A. (comp.)

1978-01-01

34

Cyclotrons and positron emitting radiopharmaceuticals  

SciTech Connect

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)

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

1984-01-01

35

An interactional approach to conceptualising small talk in medical interactions  

PubMed Central

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

Hudak, Pamela L.; Maynard, Douglas W.

2013-01-01

36

Differentiation of stereoisomeric diols by using CH3OB+OCH3 in a small Fourier transform ion cyclotron resonance mass spectrometer  

NASA Astrophysics Data System (ADS)

Gas-phase reactions of stereoisomeric cyclic diols with CH3OB+OCH3 were examined in a small Fourier transform ion cyclotron resonance mass spectrometer. CH3OB+OCH3 is a strong electrophile and rapidly abstracts an OH group from the diols studied. This very exothermic reaction is followed by spontaneous fragmentation of the resulting ion. In addition to this reaction, cis-diols also react with CH3OB+OCH3 by an intramolecular displacement of CH3OH in the initially formed, short-lived adduct ion. The product distributions allow distinction between the cis- and trans-isomers of 1,2-cyclopentanediol, and between the cis-(diendo- and diexo-) and trans-isomers of 2,3-trinorbornanediol.

Leeck, D. T.; Ranatunga, T. D.; Smith, R. L.; Partanen, T.; Vainiotalo, P.; Kenttämaa, H. I.

1995-02-01

37

Microcomputer Systems in Solo and Small Group Medical Practices  

PubMed Central

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

Bremer, Roger E.

1978-01-01

38

Future cyclotron systems: An industrial perspective  

SciTech Connect

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

Stevenson, N.R. [TRIUMF, Vancouver, BC (Canada); Dickie, W.J. [Nordion International Inc., Kanata, Ontario (Canada)

1995-09-01

39

A low background-rate detector for ions in the 5 to 50 keV energy range to be used for radioisotope dating with a small cyclotron  

SciTech Connect

Accelerator mass spectrometry in tandem Van de Graaff accelerators has proven successful for radioisotope dating small samples. We are developing a 20 cm diameter 30 to 40 keV cyclotron dedicated to high-sensitivity radioisotope dating, initially for /sup 14/C. At this energy, range and dE/dx methods of particle identification are impossible. Thus arises the difficult problem of reliably detecting 30 to 40 keV /sup 14/C at 10/sup -2/ counts/sec in the high background environment of the cyclotron, where lower energy ions, electrons, and photons bombard the detector at much higher rates. We have developed and tested an inexpensive, generally useful ion detector that allows dark-count rates below 10/sup -4/ counts/sec and excellent background suppression. With the cyclotron tuned near the /sup 13/CH background peak, to the frequency for /sup 14/C, the detector suppresses the background to 6 x 10/sup -4/ counts/sec. For each /sup 14/C ion the detectors grazing-incidence Al/sub 2/O/sub 3/ conversion dynode emits about 20 secondary electrons, which are independently multiplied in separate pores of a microchannel plate. The output signal is proportional to the number of secondary electrons, allowing pulse-height discrimination of background. We have successfully tested the detector with positive /sup 12/C, /sup 23/Na, /sup 39/K, /sup 41/K, /sup 85/Rb, /sup 87/Rb, and /sup 133/Cs at 5 to 40 keV, and with 36 keV negative /sup 12/C and /sup 13/CH. It should detect ions and neutrals of all species, at energies above 5 keV, with good efficiency and excellent background discrimination. Counting efficiency and background discrimination improve with higher ion energy. The detector can be operated at least up to 2 x 10/sup -7/ Torr and be repeatedly exposed to air. The maximum rate is 10/sup 6.4/ ions/sec in pulse counting mode and 10/sup 9.7/ ions/sec in current integrating mode.

Friedman, P.G.

1986-11-25

40

The cyclotron development activities at CIAE  

NASA Astrophysics Data System (ADS)

The cyclotron has an obvious advantage in offering high average current and beam power. Cyclotron development for various applications, e.g. radioactive ion-beam (RIB) generation, clean nuclear energy systems, medical diagnostics and isotope production, were performed at China Institute of Atomic Energy (CIAE) for over 50 years. At the moment two cyclotrons are being built at CIAE, the 100 MeV, CYCIAE-100, and a 14 MeV, the CYCIAE-14. Meanwhile, we are designing and proposing to build a number of cyclotrons with different energies, among them are the CYCIAE-70, the CYCIAE-800, and the upgrading of CYCIAE-CRM, which is going to increase its beam current to mA level. The contribution will present an overall introduction to the cyclotron development activities conducted at CIAE, with different emphasis to each project in order to demonstrate the design and construction highlights.

Zhang, Tianjue; Li, Zhenguo; An, Shizhong; Yin, Zhiguo; Yang, Jianjun; Yang, Fang

2011-12-01

41

Recent development and progress of IBA cyclotrons  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

42

Small Is Beautiful - Compact Semantics for Medical Language Processing  

Microsoft Academic Search

We introduce two abstraction mechanisms by which the process of semantic interpretation of medical documents can be simplified\\u000a and optimized. One relates to the linguistic generality, the other to the inheritance-based specification of semantic rules.\\u000a The proposed methodology leads to a parsimonious inventory of abstract, simple and domainindependent semantic interpretation\\u000a schemata whose effectiveness has been evaluated on a medical text

Martin Romacker; Stefan Schulz; Udo Hahn

1999-01-01

43

Simulation study on alpha-driven localized cyclotron modes in nonuniform magnetic field  

Microsoft Academic Search

Resonance is a fundamental issue in science and requires precise synchronization. As an ion version of cyclotron maser, relativistic ion cyclotron instability is driven by fusion produced MeV ions whose Lorentz factor is very close to unity. Cyclotron maser requires a small positive frequency mismatch between the wave and the harmonic cyclotron motion of fast particles. Thus, it is generally

Kuan-Ren Chen; Tsung-Hua Tsai; Liu Chen

2008-01-01

44

Workflow and Electronic Health Records in Small Medical Practices.  

National Technical Information Service (NTIS)

This study analyzes the workflow and implementation of Electronic Health Record (EHR) systems across different functions in small physician offices. We characterize the differences in the offices with different levels of computerization in terms of workfl...

B. B. Lide E. Subrahmanian M. Ramaiah R. D. Sriram

2010-01-01

45

Cyclotrons as mass spectrometers  

SciTech Connect

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

Clark, D.J.

1984-04-01

46

Multiresolution analysis and classification of small bowel medical images.  

PubMed

This is the first reported work in the area of small bowel image classification and a novel analysis system was developed. Principles of human texture perception were used to design features which can discriminate between abnormal and normal images. The proposed method extracts statistical features from the wavelet domain, which describe the homogeneity of localized areas within the small bowel images. To ensure that robust features were extracted, a shift-invariant discrete wavelet transform (SIDWT) was explored. LDA classification was used with the leave one out method to improve classification under the small database scenario. A total of 75 abnormal and normal bowel images were used for experimentation resulting in high classification rates: 85% specificity and 85% sensitivity. The success of the system can be accounted to the discriminatory and robust feature set (translation, scale and semi-rotational invariant), which successfully classified various sizes and types of pathologies at multiple viewing angles. PMID:18003011

Khademi, April; Krishnan, Sridhar

2007-01-01

47

Factors Influencing Electronic Clinical Information Exchange in Small Medical Group Practices  

ERIC Educational Resources Information Center

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

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

2012-01-01

48

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

Microsoft Academic Search

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

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

2001-01-01

49

Electron cyclotron heating and current drive in toroidal geometry  

NASA Astrophysics Data System (ADS)

The Principal Investigator has continued to work on problems associated both with the deposition and with the emission of electron cyclotron heating power electron cyclotron heating in toroidal plasmas. In particular, the work has focused on the use of electron cyclotron heating to stabilize q = 1 and q = 2 instabilities in tokamaks and on the use of electron cyclotron emission as a plasma diagnostic. The research described in this report has been carried out in collaboration with scientists at Princeton, MIT and Livermore. The Principal Investigator is now employed at Lehigh University, and a small group effort on electron cyclotron heating in plasmas has begun to evolve at Lehigh involving undergraduate and graduate students. Work has also been done in support of the electron cyclotron heating and current drive program at the Center for Research in Plasma Physics in Lausanne, Switzerland.

Kritz, A. H.

1993-03-01

50

Ion Cyclotron and Ion Skin Depth Effects Influences on Substorm Dynamics as Determined by Multi-Fluid/Multi-Scale Modeling: Small Scale versus Large Scale  

NASA Astrophysics Data System (ADS)

MHD models have been one of the major tools to investigate global magnetospheric dynamics. However, MHD is a single fluid description whereas the magnetosphere's composition is known to vary substantially during activity periods with heavy ionospheric ions often being the dominate ion species in the inner magnetosphere during storm periods. In addition, MHD also neglects ion skin depth and ion cyclotron effects, which are important in thin current sheets and can control the reconnection rate. Multi-fluid modeling offers the opportunity to investigate mass effects on global magnetospheric dynamics, and with recent augmentation of the code with refinement gridding, we are also able to resolve ion skin depth and ion cyclotron effects within a global magnetosphere. Previous work has demonstrated that heavy ion outflows can account for the observed saturation of the cross- polar cap potential, as such has a major influence on global transport of mass, momentum and energy within the magnetosphere. It is shown in this paper that these same outflows can have substantial variations in time and space during a substorm, and in fact are an important contributing factor to substorm onset in an isolated substorm, including the kinking and breakup of the tail current sheet. These processes produce very distinctive signatures that have many properties similar to recent Cluster observations.

Winglee, R. M.; Harnett, E. M.; Kidder, A.

2008-05-01

51

Integrating Technology into PBL Small Groups in a Medical Education Setting.  

ERIC Educational Resources Information Center

|How students used computers and Internet access in the day-to-day work of the problem-based learning (PBL) classroom was studied with second year medical students working in small learning groups. Fifteen students, one from each PBL group, met as a focus group to discuss computer and Internet use. Several themes emerged from the discussions.…

Reznich, Christopher B.; Werner, Elizabeth

52

Test particle motion in the cyclotron resonance regime  

Microsoft Academic Search

Test particles moving in the field of an electromagnetic wave propagating in a background magnetic field can gain significant energy when the wave parameters and particle energy are such that the cyclotron resonance condition is satisfied. Central to the acceleration process and long time scale periodic behavior is the coherent accumulation over many cyclotron orbits of a small change in

Gregory P. Ginet; Jay M. Albert

1991-01-01

53

The Warsaw K=160 cyclotron  

NASA Astrophysics Data System (ADS)

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

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

2001-12-01

54

Improvements and applications at NIRS cyclotron facility  

NASA Astrophysics Data System (ADS)

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. .

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

55

Commercial cyclotrons. Part I: Commercial cyclotrons in the energy range 10 30 MeV for isotope production  

NASA Astrophysics Data System (ADS)

A survey of commercial cyclotrons for production of medical and industrial isotopes is presented. Compact isochronous cyclotrons which accelerate negative hydrogen ions in the energy range 10 30 MeV have been widely used over the last 25 years for production of medical isotopes and other applications. Different cyclotron models for the energy range 10 12 MeV with moderate beam intensity are used for production of 11C, 13N, 15O, and 18F isotopes widely applied in positron emission tomography. Commercial cyclotrons with high beam intensity are available on the market for production of most medical and industrial isotopes. In this work, the physical and technical parameters of different models are compared. Possibilities of improving performance and increasing intensity of H- beams up to 2 3 mA are discussed.

Papash, A. I.; Alenitsky, Yu. G.

2008-07-01

56

Cyclotron resonance and quasiparticles  

SciTech Connect

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

Cohen, Marvin L.

2005-01-15

57

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

PubMed Central

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.

Brandon, A N

1975-01-01

58

Selected Lists of Journals for the Small Medical Library: A Comparative Analysis  

PubMed Central

The results of a survey and weighted summary of all major suggested journal subscription lists for hospital libraries are described. A total of ninety-one titles taken from 255 titles examined is listed under thirty-three subject headings. Contrasts are made of the titles and subject headings employed by others, and the potential of Stearns' “core collection” concept for small medical libraries is dealt with in detail.

Timour, John A.

1971-01-01

59

High frequency plasma heating at finite presure in region of ion cyclotron frequencies  

NASA Astrophysics Data System (ADS)

The heating of an inhomogeneous plasma cylinder by electromagnetic waves at approximately the ion cyclotron frequency is investigated. Analytical expressions are derived for the amount of power absorbed by the plasma. It is found that ion cyclotron resonance of the primary gas is an effective heating mechanism in Drakon-type installations with reactor parameters, in contrast to systems with small beta. The cyclotron attenuation at harmonics of the ion cyclotron frequency of the primary gas is found to be very strong. The width of the cyclotron resonance zone for waves with small enough values of k parallel is smaller than the plasma dimensions because of the plasma diamagnetism. Cherenkov absorption by electrons is also strong. It is found possible to excite intrinsic oscillations only for small values of k parallel or in small installations; cyclotron resonance by the Alfven branch of the oscillations can be employed in small installations.

Grekov, D. L.; Stepanov, K. N.

1986-02-01

60

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

PubMed

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

Brandon, A N; Hill, D R

1981-04-01

61

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

PubMed Central

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

Brandon, A N; Hill, D R

1981-01-01

62

Activities at iThemba LABS Cyclotron Facilities  

NASA Astrophysics Data System (ADS)

iThemba Laboratory for Acceleratory Based Sciences (iThemba LABS) is a multi-disciplinary cyclotron facility. Chief among its activities is the operation of a k=200 sepparate sector cyclotron (SSC) which provides proton beams of energies up to 200 MeV. These beams are used for fundamental nuclear physics research in the intermediate energy region, isotope production and medical physics applications. Details on developments regarding the new flagship project at iThemba LABS are also presented.

Bark, R. M.; Cornell, J.; Lawrie, J. J.; Vilakazi, Z. Z.

63

DESIGN STUDY OF THE 30 MeV CYCLOTRON MAGNET  

Microsoft Academic Search

Korea Institute of RAdiological & Medical Sciences (KIRAMS) has been developing a 30 MeV cyclotron that is planned to be installed at Advanced Radiation Technology Institute, Jeongeup in late 2006. The AVF (Azimuthally Varying Field) magnet of the cyclotron was designed to produce 15-30 MeV proton beam with movable stripper foil. Four directions of extractions are available with two switching

J. Kang; B. H. Hong; H. S. Chang; I. S. Jung; J. S. Chai

64

Cryopumping for Cyclotrons  

Microsoft Academic Search

High pumping speeds and high pumping capacities are required for the vacuum systems of large cyclotrons. Only cryopumps and getter pumps safely provide these features. The best pumping system for a particular machine can be designed only upon fixing size, operating pressure, pumpdown time, mechanical design and materials of the latter. The criteria for the selection of the pumps are

Cristoforo Benvenuti

1979-01-01

65

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

PubMed Central

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

Brandon, A N; Hill, D R

1991-01-01

66

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

PubMed

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

Brandon, A N; Hill, D R

1985-04-01

67

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

PubMed

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

Brandon, A N; Hill, D R

1987-04-01

68

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

PubMed

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

Brandon, A N; Hill, D R

1983-04-01

69

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

PubMed

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

Brandon, A N; Hill, D R

1989-04-01

70

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

PubMed

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

Brandon, A N; Hill, D R

1991-04-01

71

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

PubMed Central

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

Brandon, A N; Hill, D R

1987-01-01

72

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

PubMed Central

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

Brandon, A N; Hill, D R

1985-01-01

73

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

PubMed Central

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.

Brandon, A N; Hill, D R

1983-01-01

74

[Hemodynamic evaluations of patients with small aortic annulus with St. Jude Medical prosthetic heart valve].  

PubMed

As the elderly population in Japan increases, senile degenerative aortic valvular disease also tends to increase. These patients often have a small aortic annulus. The problem of "valve-patient-mismatch" occurs when a small prosthesis is inserted into a patient with a small aortic annulus. To avoid annular enlargement after aortic valve replacement (AVR), we tried to use a small-sized St. Jude Medical (SJM) valve. From September 1988 through November 1996, 110 AVR were performed in our institution. In these cases, 30 underwent AVR with a small sized SJM valve (male < or = 21 mm, female < or = 19 mm). Dobutamine stress echocardiography was performed in 19 patients who had undergone AVR with a small-sized SJM valve. Surgical results were also compared between patients with small aortic annulus and those with normal-sized aortic annulus. Using Doppler echocardiography, pressure gradients (PG), cardiac index (CI), effective orifice area (EOA), and performance index (PI) were calculated at rest and during stress. The mean body surface area (BSA) of patient who had undergone AVR with SJM19A, 19HP and 21A was 1.40, 1.42 and 1.56 m2, respectively. With dobutamine stress, heart rates, PG and CI increased significantly. Mean and maximum PG of patients with 19HP (8.0 and 15.4 mmHg at rest, 12.9 and 28.0 mmHg under stress, respectively) and 21A (9.5 and 19.1 mmHg at rest, 16.5 and 35.3 mmHg under stress, respectively) were relatively low. EOA index (EOAI) of patient with 19HP showed the highest values mean 0.93 cm2/m2. PIs tended to be higher with HP models than with standard models. The tests were completed without significant side effects such as frequent ventricular arrhythmias. Among the cases with small aortic annulus, there were no operative deaths or hospital deaths. There were also no late deaths, episodes of hemorrhage or thrombosis. Conclusions. In our institution, AVR was performed safely without any aortic annular enlargement with a small aortic anulus in small BSA patients. Postoperative hemodynamic data obtained by echocardiography were satisfactory for all patients at rest and even during maximum dobutamine stress test. PMID:10037837

Shimabukuro, T; Takeuchi, Y; Gomi, A; Nakatani, H; Suda, Y; Kono, K; Nagano, N

1998-12-01

75

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

PubMed Central

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

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

2013-01-01

76

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

Microsoft Academic Search

As a part of the Upgrade Project of Beijing Tandem Accelerator Laboratory, a 100 MeV compact cyclotron was designed for the generation of high intensity proton beam. In comparison the H- beam intensity injected into the cyclotron central region of the 30 MeV medical cyclotron developed at CIAE 8 years ago, those injected into the 100 MeV machine will be

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

2004-01-01

77

Design and development of low-loss transformer for powering small implantable medical devices.  

PubMed

Small implantable medical devices, such as wireless capsule endoscopes, that can be swallowed have previously been developed. However, these devices cannot continuously operate for more than 8 h because of battery limitations; moreover, additional functionalities cannot be introduced. This paper proposes a design method for a high-efficiency energy transmission transformer (ETT) that can transmit energy transcutaneously to small implantable medical devices using electromagnetic induction. First, the authors propose an unconventional design method to develop such a high-efficiency ETT. This method can be readily used to calculate the exact transmission efficiency for changes in the material and design parameters (i.e., the magnetic material, transmission frequency, load resistance, etc.). Next, the ac-to-ac energy transmission efficiency is calculated and compared with experimental measurements. Then, suitable conditions for practical transmission are identified. A maximum efficiency of 33.1% can be obtained at a transmission frequency of 500 kHz and a receiving power of 100 mW for a receiving coil size of ¿5 mm × 20 mm. Future design optimization is possible by using this method. PMID:23853315

Shiba, K; Morimasa, A; Hirano, H

2010-04-01

78

Correlation of MRI-determined small bowel Crohn's disease categories with medical response and surgical pathology  

PubMed Central

AIM: To determine whether magnetic resonance imaging (MRI) can be used to categorize small bowel Crohn’s disease (SB CD) into groups that correlate with response to medical therapy and surgical pathology. METHODS: Data was collected from all patients with MRI evidence of SB CD without significant colonic disease over a 32-mo period. Two radiologists, blinded to clinical findings, evaluated each MRI and grouped them based on bowel wall thickness and wall enhancement. These categories were: (1) “fibrosis”, (2) “mild segmental hyper-enhancement and mild wall thickening”, (3) “mild segmental hyper-enhancement and marked wall thickening”, (4) “marked segmental transmural hyper-enhancement”. Patient response to additional medical therapy post-MRI was prospectively determined at 8-wk. Non-responders underwent endoscopy and were offered therapeutic endoscopy or surgery. Surgical pathology was assessed against the MRI category. RESULTS: Fifty-five patients were included. Females and category “2” patients were more likely, and patients with luminal narrowing and hold-up less likely, to respond to medical therapy (P < 0.05). Seventeen patients underwent surgery. The surgical pathological findings of fibrosis and the severity of inflammation correlated with the MRI category in all cases. CONCLUSION: Our findings suggest that SB CD can be grouped by the MRI findings and that these groups are associated with patients more likely to respond to continued medical therapy. The MRI categories also correlated with the presence and level of intestinal inflammation and fibrosis on surgical pathology, and may be of prognostic use in the management of CD patients.

Lawrance, Ian Craig; Welman, Christopher J; Shipman, Peter; Murray, Kevin

2009-01-01

79

Intensity limitations in compact H{sup minus} cyclotrons  

SciTech Connect

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

Baartman, R.A.

1995-12-31

80

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

PubMed Central

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

Brandon, A N; Hill, D R

1995-01-01

81

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

PubMed

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

Brandon, A N; Hill, D R

1995-04-01

82

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

PubMed Central

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.

Brandon, A N; Hill, D R

1997-01-01

83

New magnet pole shape for isochronous cyclotrons  

SciTech Connect

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

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

1981-06-01

84

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

PubMed Central

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.

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

2012-01-01

85

Cyclotron resonance of trilayer graphene  

NASA Astrophysics Data System (ADS)

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

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

2012-08-01

86

Recent developments in superconducting cyclotrons  

Microsoft Academic Search

Superconducting cyclotrons have come of age: three machines have been operating on a regular basis since several years. These first generation machines have benefited from improvement programs and new equipment, while proposals for further expansion of their capabilities have been elaborated. The most significant events of 1994 have been the first beams in two new machines: the AGOR cyclotron in

H. W. Schreuder

1995-01-01

87

Cyclotron laboratory (CyLab) of Slovak metrological institute.  

National Technical Information Service (NTIS)

The calculations of parameters of the compact isochronous cyclotron 'CyLab' (Slovak Republic) for medical diagnostics and other applied purposes are presented. The accelerator will be able to deliver from H(sup +) ions to Xe(sup +40) ions, with energies 7...

O. N. Borisov S. B. Vorozhtsov G. G. Gul'bekyan G. A. Karamysheva N. A. Morozov

1997-01-01

88

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

PubMed Central

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

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

2013-01-01

89

Ion cyclotron resonance cell  

DOEpatents

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.

Weller, R.R.

1995-02-14

90

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

PubMed Central

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

Brandon, A N; Hill, D R

1993-01-01

91

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

PubMed Central

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

Hill, Dorothy R.; Stickell, Henry N.

2001-01-01

92

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

SciTech Connect

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.

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

2006-07-01

93

Nonlinear cyclotron harmonic absorption  

SciTech Connect

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.

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

94

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

PubMed

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

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

95

A Small but Significant Difference - The Role of Gender on Acceptance of Medical Assistive Technologies  

Microsoft Academic Search

\\u000a The current research aimed to study user diversity with a focus on gender differences in adoption of medical assistive technologies\\u000a in general, and in particular. In order to understand the gender impact, we conducted two consecutive studies and considered\\u000a gender as a key moderator of acceptance aspects in the medical context. The first study focused on general aspects of medical

Wiktoria Wilkowska; Sylvia Gaul; Martina Ziefle

2010-01-01

96

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

NASA Astrophysics Data System (ADS)

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

Nagai, Chiaki; Moriwaki, Toshimichi

97

Radioactive nuclei for medical applications  

NASA Astrophysics Data System (ADS)

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.

Jastrz?bski, Jerzy

2011-01-01

98

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

SciTech Connect

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

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

1985-12-31

99

Medical disorders in a small Caribbean island. An analysis of the disease of adults in Dominica in 1972 and 1973.  

PubMed

An analysis was undertaken, for the first time, of the total picture of the medical disorders of adults on a small Caribbean island. At present non-infectious diseases, especially diabetes and hypertension, are of major improtance. Parasitic infestation of the gut occurred in 50-60% of the hospital population. The pattern of diseases indicates that the island is in a transitional stage of its medical development, and that resources need not be directed to the curative as well as to public health programmes. The impact of peculiarities of local geography and customs are discussed as contributing to some of the more unusual diseases of the Caribbean. PMID:1267503

Grell, G A

1976-03-01

100

Medical image texture analysis: A case study with small bowel, retinal and mammogram images  

Microsoft Academic Search

This work concerns the development of a generalized framework for computer-aided diagnosis of medical images. The system is built to mimic human texture perception as texture has been shown to be an important feature for pathology discrimination in medical images. In particular, it was shown by Julesz that orientation, frequency and scale are important markers for texture discrimination. Consequently, this

April Khademi; Sridhar Krishnan

2008-01-01

101

Shielding calculations for Inshas cyclotron  

NASA Astrophysics Data System (ADS)

Methods used in shielding calculations for the cyclotron vault and experimental rooms of Egypt's first cyclotron laboratory to be erected at the premises of the Nuclear Research Center, Atomic Energy Authority (Inshas) are discussed. Use is made of the removal diffusion theory and of the techniques presented in NCRP-51, Wall and ceiling dimensions are estimated based on radiation protection norms given in the ICRP-60 as issued in 1991.

Comsan, M. N. H.

1996-05-01

102

Hemodynamic evaluations of patients with small aortic annulus with St. Jude Medical prosthetic heart valve  

Microsoft Academic Search

As the elderly population in Japan increases, senile degenerative aortic valvular disease also tends to increase. These patients\\u000a often have a small aortic annulus. The problem of “valve-patient-mismatch” occurs when a small prosthesis is inserted into\\u000a a patient with a small aortic annulus. To avoid annular enlargement after aortic valve replacement (AVR), we tried to use\\u000a a small-sized St. Jude

Takashi Shimabukuro; Yasuo Takeuchi; Akihiko Gomi; Hayao Nakatani; Yuji Suda; Koji Kono; Naoko Nagano

1998-01-01

103

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

SciTech Connect

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.

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

2009-03-31

104

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

NASA Astrophysics Data System (ADS)

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.

Sambuu, Odmaa; Nanzad, Norov

2009-03-01

105

Ion cyclotron waves near Io  

NASA Astrophysics Data System (ADS)

In this work, we discuss the properties of the ion cyclotron waves observed by the Galileo spacecraft in the Io torus on December 7, 1995. These waves are generated by anisotropies in the pickup ion distributions present in the region. To zeroth order the waves grow at the sulfur dioxide gyrofrequency, are left-hand polarized and propagate along the magnetic field. A more detailed study reveals that in some regions the waves grow over a finite bandwidth, with frequencies near the SO + and S + gyrofrequencies, propagate at an angle to the field, and are elliptically polarized. We perform a kinetic dispersion analysis and show that while the parallel propagating SO 2+ cyclotron mode has the largest growth, oblique cyclotron waves can also grow with a significant rate in the multicomponent plasma near Io. We find that decreasing the sulfur dioxide pickup ion density, and including a SO + pickup component can lead to instabilities generated by the sulfur monoxide and sulfur components in the plasma, and to the observed bandwidth of frequencies. Therefore, it is possible that in addition to the waves generated by SO 2+ pickup ions, in some regions Galileo observed ion cyclotron waves generated by anisotropic distributions of SO + and S + ions. When Voyager 1 flew by the torus in 1979 the spacecraft detected the Alfvén wing but no cyclotron waves were observed in the data. We evaluate the group and phase velocities of ion cyclotron waves and find that both are smaller than the Alfvén velocity. Then it is possible that the cyclotron waves can get carried away before they reach Voyager.

Blanco-Cano, X.; Russell, C. T.; Huddleston, D. E.; Strangeway, R. J.

2001-08-01

106

Relativistic cyclotron resonance shape in magnetic bottle geonium  

PubMed Central

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

Dehmelt, Hans; Mittleman, Richard; Liu, Yuan

1988-01-01

107

Legal Regulation of the Croatian Medical Journal: Model for Small Academic Journals  

Microsoft Academic Search

During the last few years, the questions of editorial independence and journal governance have come into the focus of scholarly journals. There is little data on the legal regulation of journals outside mainstream science, although they con- stitute the largest body of biomedical literature. The Croatian Medical Journal functioned for more than 10 years with- out much legal regulation but

Silva Rulic-Hren

2003-01-01

108

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

ERIC Educational Resources Information Center

|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…

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

2004-01-01

109

[Role of cooperation of small enterprises in the production of rigid medical endoscopes].  

PubMed

The paper briefly describes the purposes and technical data of rigid endoscopes with grading optic elements designed and produced by 3 small enterprises which have common aims and methods of their fulfillment. It also gives brief characteristics of Russian gradanes used as objectives and translators of optic image. The experience of cooperation of small enterprises shows that not only a very large-scale optic enterprise, but an amalgamation of small enterprises may solve such a difficult problem as design and serial production of thin rigid endoscopes due to cooperation of all those having a required scientific-and-technical potential. PMID:9611748

D'iakonov, S Iu; Kats, A I; Remizov, N V

110

The radium institute cyclotron MGC-20  

SciTech Connect

The cyclotron of the MGC-20 type was designed by NIIEFA in 1970. Since that time, 7 machines of this type have been made with 3 of them installed at St Petersburgh, 1 in Moscow, and 3 more abroad. The first beam of the Radium Institute cyclotron was obtained in 1988. The MGC-20 is a variable energy cyclotron, suitable for acceleration of light ions. The cyclotron is described.

Solin, L.M.; Lebedev, L.S.; Selitsky, Yu.A. [V.G. Khlopin Radium Institute (Russian Federation)] [and others

1993-12-31

111

Rib Projects of Sendai New Cyclotron  

NASA Astrophysics Data System (ADS)

The AVF cyclotron at CYRIC has been replaced from K=50 MeV AVF cyclotron to K=130 MeV AVF cyclotron. All of the missions for replacement have been almost completed. It has started the commissioning for beam tuning and has partly been opened for experiments. Outline of the new plans by the new cyclotron will be presented including the RI beam projects under consideration.

Shinozuka, T.

112

Helium cyclotron resonance within the earth's magnetosphere  

Microsoft Academic Search

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

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

1981-01-01

113

St. Jude medical cardiac valves in small aortic roots: Follow-up to sixteen years  

Microsoft Academic Search

Prosthetic aortic valve replacement in the small aortic root raises concerns of its long-term effects. Between 1978 and 1994, 270 patients received only small aortic prostheses (? 21 mm). There were 117 men (43.3%) and 153 women (56.7%) with a mean age of 64.3 ± 11.6 years (range 19 to 87 years). The body surface areas ranged from 1.2 to

Dilip Sawant; Arun K. Singh; William C. Feng; Arthur A. Bert; Fred Rotenberg

1997-01-01

114

Cyclotron Radiation from Electrons in Magnetosphere.  

National Technical Information Service (NTIS)

Cyclotron power radiated by an electron and total cyclotron power has been calculated and its variation along different geomagnetic lines of force has been shown. The polar diagram of the radiated cyclotron power has been worked out. In view of the direct...

R. N. Singh R. P. Singh

1969-01-01

115

Oak Ridge Isotope Production Cyclotron Facility and Target Handling  

Microsoft Academic Search

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

Eric Craig Bradley; Venugopal Koikal Varma; Jeffrey L Binder; Saed Mirzadeh; B Alan Tatum; Thomas W Burgess; Joe Devore; Mark Rennich; Michael John Saltmarsh; Benjamin Cale Caldwell

2011-01-01

116

Small-bore, polymer-coated hollow fibers for medical infrared lasers  

Microsoft Academic Search

For medical applications, a hollow fiber is an effective delivery medium for infrared lasers represented by Er:YAG and CO2 lasers which common silica glass fibers cannot transmit due to the absorption. We have developed hollow fibers with a polymer thin film upon the inside of silver-coated glass capillary tube and shown their low loss properties for high-powered infrared lasers. In

Y. Abe; Y. Matsuura; M. Miyagi

1999-01-01

117

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

PubMed

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

Andrews, Gavin J; Phillips, David R

2005-05-01

118

The cyclotron trap for antiprotons  

NASA Astrophysics Data System (ADS)

The cyclotron trap is a device to increase the stop density of negatively charged particles. Its working principle is to wind up the range of a stopping particle in a weak focusing magnetic field. Its main application in the past was the spectroscopy of exotic atoms. A modern application is the production of low energy muon or antiproton beams.

Simons, L. M.

1993-03-01

119

Ion sources for cyclotron applications  

SciTech Connect

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.

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

1992-07-01

120

LBNL 88-inch Cyclotron improvements  

Microsoft Academic Search

A number of recent improvements have been made in the Cyclotron, ECR sources and beam lines. An aluminum oxide wall coating in the AECR source produces more secondary electrons to increase high charge state ion production by 2-4 compared to electron injection. Development of simultaneous multiple frequency ECR heating with 10 and 14 GRz results in two ECR zones and

C. M. Lyneis; Z. Q. Xie; D. J. Clark

1996-01-01

121

Women and small cell lung cancer: social characteristics, medical history, management and survival  

Microsoft Academic Search

The literature make it clear that lung cancer in women differs from that in men in several specific aspects. We conducted a retrospective study of the 967 consecutive recorded patients (696 men and 91 women after exclusions) diagnosed with small cell lung cancers (SCLC) between 1981 and 1994 in the Bas-Rhin population-based cancer registry to determine if such particularities could

Bertrand Mennecier; Marie-Paule Lebitasy; Lionel Moreau; Guy Hedelin; Ashok Purohit; Cedric Galichet; Elisabeth Quoix

2003-01-01

122

Cyclotron Production of Technetium-99m  

NASA Astrophysics Data System (ADS)

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

Gagnon, Katherine M.

123

TRIUMF cyclotron vacuum system refurbishing  

NASA Astrophysics Data System (ADS)

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.

Sekachev, I.

2008-03-01

124

High brightness 50 MeV Cyclotron for Accelerator-Driven Subcritical Fission  

NASA Astrophysics Data System (ADS)

The Accelerator Research Lab at Texas A&M University is developing new accelerator technology for a high-brightness, high-current cyclotron with capabilities that will be beneficial for applications to accelerator-driven subcritical fission, medical isotope production, and proton therapy. As a first embodiment of the technology, we are developing a detailed design for TAMU-50, a 50 MeV, 5 mA proton cyclotron with high beam brightness. In this presentation we present devices and beamline components for injection, extraction, controls and diagnostics. We emphasize the system integration and implementation of TAMU-50 for production of medical radioisotopes.

Assadi, Saeed; Badgley, Karie; Mann, Thomas; McIntyre, Peter; Pogue, Nathaniel; Sattarov, Akhdiyor

2011-10-01

125

Medical treatment of small cell lung cancer: state of the art and new development.  

PubMed

Introduction: Small cell lung cancer (SCLC) is a rapidly progressive disease that accounts for approximately 15% of all lung cancers. Chemotherapy remains the cornerstone of treatment of SCLC, but in the last two decades, its progress has reached a plateau. Although a significant sensitivity to chemotherapy and radiotherapy is a feature of SCLC, an early development of drug resistance unavoidable occurs during the course of the disease. Second-line treatment for relapsed patients remains a very challenging setting, with a limited clinical benefit. Areas covered: A thorough analysis of various therapeutic strategies reported in literature for SCLC treatment was performed. This review includes novel therapeutic approaches such as maintenance or consolidation treatments, new chemotherapy agents and targeted therapy. Expert opinion: Against this background, there is a desperate need for the development of novel active drugs. Among these, amrubicin has also shown more favourable antitumor activity, and is the most promising at present. Concerning targeted agents, these have failed to demonstrate effectiveness for SCLC and a better understanding of the molecular mechanisms is clearly needed. In the future, further investigations are required to clarify the role of novel anti-angiogenic or pro-apoptotic agents and hedgehog pathway inhibitors. PMID:23901936

Sgambato, Assunta; Casaluce, Francesca; Maione, Paolo; Rossi, Antonio; Sacco, Paola Claudia; Panzone, Filomena; Ciardiello, Fortunato; Gridelli, Cesare

2013-08-01

126

Commercial compact cyclotrons in the 90`s  

SciTech Connect

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

Milton, B.F.

1995-09-01

127

Method and apparatus for ion cyclotron spectrometry  

DOEpatents

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.

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

2010-08-17

128

Research Activities At The RCNP Cyclotron Facility  

NASA Astrophysics Data System (ADS)

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

Hatanaka, Kichiji

2010-05-01

129

Space charge effects in RIKEN cyclotrons  

NASA Astrophysics Data System (ADS)

The RI Beam Factory is under construction at RIKEN. The new accelerator system consists of three cascade cyclotrons, and Experimental Storage rings. Space charge effects on the beams are the subjects to be studied. Acceleration of the ions 16O8+ and 238U88+ was considered in the Superconducting Ring Cyclotron (SRC). The flattop (FT) compensation of the longitudinal space charge (LSC) was attempted. In the AVF cyclotron the simulation of the energy spread suppression by FT was fulfilled. .

Vorojtsov, S. B.; Vorozhtsov, A. S.; Goto, A.; Mitsumoto, T.; Fukunishi, N.; Yano, Y.

2001-12-01

130

FFAGs and Cyclotrons with Reverse Bends  

NASA Astrophysics Data System (ADS)

This paper describes tracking studies of radial-sector FFAGs and cyclotrons with reverse bends using the cyclotron equilibrium orbit code CYCLOPS. The results for FFAGs confirm those obtained with lumped-element codes, and suggest that cyclotron codes will prove to be important tools for evaluating the measured fields of FFAG magnets. The results for radial-sector cyclotrons show that the use of negative valley fields would allow vertical focusing to be maintained, and hence allow intense cw beams to be accelerated, to energies as high as 10 GeV.

Craddock, Michael; Rao, Yi-Nong

2009-05-01

131

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

NASA Astrophysics Data System (ADS)

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

McMahan, Margaret; Clark, David

2003-04-01

132

Orbit dynamics in isochronous cyclotrons  

SciTech Connect

Acceleration of heavy ions in an isochronous cyclotron can lead to a ..nu../sub r/-value near unity for many turns. In ORIC, several departures from 3-fold symmetry unfortunately exist, so that a complex resonant behavior may lead to beam loss. To study these questions, a program has been initiated with the aim of devising and using very efficient algorithms for calculating the motion of ions during acceleration. The eikonal function was chosen as the basis for these studies, with methods and some results here described.

Welton, T.A.; Nichols, T.

1981-01-01

133

The cyclotrons in my life  

SciTech Connect

This story is about two cyclotrons. The first was the one I helped build when I was a graduate student at Columbia; the second, I built with John Marshall at the University of Chicago after World War II. This is also a story about a graduate student who happened to be in the right place at the right time. In that sense it is an example of the opportunity that every graduate student can look forward to as a result of doing research on the frontiers of science, where the possibilities are endless. My own story had that kind of excitement. 9 refs., 21 figs.

Anderson, H.L.

1989-08-01

134

Fluid theory of beam spiraling in high intensity cyclotrons  

NASA Astrophysics Data System (ADS)

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

Cerfon, Antoine; Parra, Felix; Freidberg, Jeffrey

2012-10-01

135

Hypofractionated three-dimensional conformal radiotherapy for medically inoperable early stage non-small-cell lung cancer  

PubMed Central

Purpose The purpose of this study was to assess the clinical outcomes of hypofractionated radiotherapy (HFRT) with three-dimensional conformal technique for medically inoperable patients with early stage non-small-cell lung cancer (NSCLC) and to evaluate prognostic factors. Materials and Methods We performed a retrospective review of 26 patients who underwent HFRT for early stage NSCLC between September 2005 and August 2011. Only clinical stage T1-3N0 was included. The median RT dose was 70 Gy (range, 60 to 72 Gy) and the median biologically equivalent dose (BED) was 94.5 Gy (range, 78.0 to 100.8 Gy). In 84.6% of patients, 4 Gy per fraction was used. Neoadjuvant chemotherapy with paclitaxel and cisplatin was given to 2 of 26 patients. Results The median follow-up time for surviving patients was 21 months (range, 13 to 49 months). The overall response rate was 53.9%, and the initial local control rate was 100%. The median survival duration was 27.8 months. Rates of 2-year overall survival, progression-free survival (PFS), local control (LC), and locoregional-free survival (LRFS) were 54.3%, 61.1%, 74.6%, and 61.9%, respectively. Multivariate analysis showed that BED (>90 vs. ?90 Gy) was an independent prognostic factor influencing PFS, LC, and LRFS. Severe toxicities over grade 3 were not observed. Conclusion Radical HFRT can yield satisfactory disease control with acceptable rates of toxicities in medically inoperable patients with early stage NSCLC. HFRT is a viable alternative for clinics and patients ineligible for stereotactic ablative radiotherapy. BED over 90 Gy and 4 Gy per fraction might be appropriate for HFRT.

Lee, Joo Ho; Kim, Hak Jae; Park, Charn Il; Lee, Se-Hoon; Kim, Dong-Wan; Heo, Dae Seog

2013-01-01

136

Recovery of Laughlin correlations with cyclotron braids  

NASA Astrophysics Data System (ADS)

Cyclotron braid subgroups are defined in order to identify the topological origin of Laughlin correlations in 2D Hall systems. Flux tubes and vortices for composite fermion constructions are explained in terms of cyclotron braids. The odd and even denominator fractional lowest Landau level fillings are discussed.

Jacak, J.; Jacak, L.

2010-12-01

137

Cyclotron Techniques for Radiation Damage Studies  

Microsoft Academic Search

This report describes the methods and equipment developed for the irradiation of materials under controlled conditions on the 60-inch Berkeley cyclotron. Descriptions are given of the components of equipment for use in the temperature range from ?195°C to 2000°C. These include target boxes which accurately locate the specimens to be irradiated in the cyclotron beam, a cold helium circulating system

H. P. Yockey; A. Andrew; F. L. Fillmore; L. E. Glasgow; C. D'A Hunt; J. H. Pepper

1954-01-01

138

Computer design of a compact cyclotron  

NASA Astrophysics Data System (ADS)

Here we present results of the computer design of the structural elements of a compact cyclotron by the example of HITFiL cyclotron selected as the driving accelerator that is under construction at the Institute of Modern Physics (Lanzhou, China). In the article a complex approach to modeling of the compact cyclotron, including calculation of electromagnetic fields of the structural elements and beam dynamics calculations, is described. The existing design data on the axial injection, magnetic, acceleration and extraction systems of the cyclotron are used as a starting point in the simulation. Some of the upgrades of the cyclotron structural elements were proposed, which led to substantial improvement of the beam quality and transmission.

Wang, Bing; Hao, Huanfeng; Vorozhtsov, S. B.; Smirnov, V. L.; Yao, Qinggao; Zhang, Jinquan; Song, Mingtao; Zhao, Hongwei

2012-05-01

139

Kompaktnyj izokhronnyj tsiklotron KITs-35 (vybor parametrov). (Compact isochronous cyclotron CIC-35 (parameters choice)).  

National Technical Information Service (NTIS)

Choosing of parameters of a compact isochronous cyclotron CIC-35 intended for medical radioisotope production is considered. Acceleration of the H(sup -)-ions beam of 200 mkA to 15-35 MeV energy is assumed. 14 refs.; 8 figs.; 3 tabs. (Atomindex citation 2...

O. N. Borisov Z. V. Borisovskaya S. B. Vorozhtsov V. P. Dmitrievskij O. V. Lomakina

1992-01-01

140

The irradiation facility at the AGOR cyclotron  

NASA Astrophysics Data System (ADS)

The KVI is conducting radiobiology research using protons up to 190 MeV from the superconducting AGOR cyclotron in collaboration with the University Medical Center Groningen (UMCG) since 1998. Using the same set-up, we have started irradiations for radiation hardness studies of detectors and components for the European Space Agency (ESA) and industrial parties. For these irradiations, we use either mono-energetic protons or a simulated solar flare energy spectrum with fluxes up to 5 × 108 protons cm-2 s-1. Furthermore, tests of radiation effects such as single event upsets, are being performed with intensities down to a few particles/s. Different energies are achieved by degrading the primary beam energy. We are currently developing the capability for heavy ion irradiations in air with beams up to Xe at beam energies between 15 and 45 MeV per nucleon. Performing the irradiations in air simplifies handling and monitoring of the device under test. The high energy allows penetration to the active layer of electronic devices, without modifications to the chip housing. The different ions provide a wide range in LET.

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

2007-08-01

141

Simulation study on alpha-driven localized cyclotron modes in nonuniform magnetic field  

NASA Astrophysics Data System (ADS)

Resonance is a fundamental issue in science and requires precise synchronization. As an ion version of cyclotron maser, relativistic ion cyclotron instability is driven by fusion produced MeV ions whose Lorentz factor is very close to unity. Cyclotron maser requires a small positive frequency mismatch between the wave and the harmonic cyclotron motion of fast particles. Thus, it is generally believed that it can not survive the nonuniformity of magnetic field such as in realistic devices. However, our simulations have shown that localized cyclotron waves are excited when the magnetic field is with a sinusoidal nonuniformity much larger than the frequency mismatch required. This indicates that resonance is a consequence of the need to drive instability for dissipating free energy and increasing the entropy. When a favorable wave eigen-frequency is collectively decided in a coherent means, a special wave form in real space is created for this purpose, even without boundary. Furthermore, the results also indicate that the wave eigen-frequency found can be lower than the local harmonic cyclotron frequency. The simulation results are compared with the analytical results from a perturbation theory.

Chen, Kuan-Ren; Tsai, Tsung-Hua; Chen, Liu

2008-11-01

142

The Coaxial-Ring Cyclotron as a powerful multipurpose proton accelerator  

NASA Astrophysics Data System (ADS)

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.

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

1997-02-01

143

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

Microsoft Academic Search

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.

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

2009-01-01

144

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

ERIC Educational Resources Information Center

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

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

2006-01-01

145

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

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

PhD Jonathan Kibble (St. George's University Department of Physiology and Neuroscience); PhD Penelope Hansen (Memorial University Basic Science Division); Loren Nelson (St. George's University Department of Physiology and Neuroscience)

2006-12-01

146

Electron cyclotron emission from nonthermal tokamak plasmas  

SciTech Connect

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.

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

147

Preliminary safety evaluation of a cyclotron facility for positron emission tomography imaging  

Microsoft Academic Search

.   This work describes the design characteristics of a medical imaging centre which uses positron emission tomography, with\\u000a a cyclotron for fluorine-18 and nitrogen-13 production, and which has provided experimental information on operational data\\u000a recorded by area dosimetry since 1995. Doses to radiopharmacy and medical staff have been measured both in normal work and\\u000a in some handling incidents. Data on

L. González; E. Vañó; C. A. Cordeiro; J. L. Carreras

1999-01-01

148

Electron cyclotron resonance plasma photos  

SciTech Connect

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

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

2010-02-15

149

All-magnetic extraction for cyclotron beam reacceleration  

DOEpatents

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

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

1975-07-22

150

Radio-frequency system of the KIRAMS-30 cyclotron for RI mass production  

NASA Astrophysics Data System (ADS)

The KHIMA (Korea Heavy Ion Medical Accelerator) had developed the KIRAMS-30 cyclotron in collaboration with the ARTI (Advanced Radiation Technology Institute). This cyclotron is able to accelerate proton for the mass production of radioisotopes. It is designed to use two normal conduct RF cavities. The resonant frequency of the ion is 15.99 MHz because of the magnet design and the beam dynamics. The RF frequency is 63.96 MHz because of the 4 th harmonic number. By using computer simulation codes, we estimated the principle design parameters of the RF system, we simulated the electric field distribution. In this paper, we present the design features, the results of quality assessment tests for the RF system, and important issues taken into consideration when designing such a cyclotron.

Jung, In Su; Park, Yeunsoo; Kang, Joonsun; Kang, Gun Uk; An, Dong Hyun; Hahn, Garam; Hong, Bong Hwan; Hur, Min Goo; Cho, Jun Dong; Kim, Moon-Hyun; Kwon, Key Ho

2012-07-01

151

Method and apparatuses for ion cyclotron spectrometry  

DOEpatents

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.

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

2012-03-06

152

Cyclotron radiation losses in subcompact tori  

SciTech Connect

Subcompact tori such as the field reversed mirror (FRM) have a relatively large surface to volume ratio. This has raised concern that in advanced fuel devices cyclotron losses could prevent their viability as reactors. Indeed the cyclotron radiation produced is several times the fusion power. However, due to reabsorption in the FRM plasma, it turns out that less than 7% of the cyclotron radiation produced escapes the plasma. Then when reflection from the first wall is included, net losses are reduced further to < 3 despite a 10% hole fraction in the wall for injector ports. Finally, a global model studies of the FRM show that even if the cyclotron loss rates are four times that predicted, the reactor energy balance remains viable.

Tetley, W.; Miley, G.

1980-01-01

153

Space charge effects in cyclotron gas stopper  

Microsoft Academic Search

The cyclotron gas stopper is a newly proposed device to stop energetic rare isotope ions from projectile fragmentation reactions in a helium-filled chamber [1,2]. The radioactive ions are slowed down by collisions using a buffer gas inside a cyclotron-type magnet and are extracted via interactions with a radio frequency (RF) field applied to a sequence of concentric electrodes (RF carpet).

Yuri K. Batygin

2011-01-01

154

Space Charge Effects in Cyclotron Gas Stopper  

Microsoft Academic Search

The cyclotron gas stopper is a newly proposed device to stop energetic rare\\u000aisotope ions from projectile fragmentation reactions in a helium-filled\\u000achamber. The radioactive ions are slowed down by collisions with a buffer gas\\u000ainside a cyclotron-type magnet and are extracted via interactions with a Radio\\u000aFrequency (RF) field applied to a sequence of concentric electrodes (RF\\u000acarpet). The

Yuri K. Batygin

2010-01-01

155

Cyclotron resonance heating systems for SST1  

Microsoft Academic Search

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

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

2006-01-01

156

A Trial of Team-Based Versus Small-Group Learning for Second-Year Medical Students: Does the Size of the Small Group Make a Difference?  

Microsoft Academic Search

Background: Team-based learning is a large-group instructional modality intended to provide active learning with modest faculty resources. Purpose: The goal is to determine if team-based learning could be substituted for small-group learning in case sessions without compromising test performance or satisfaction. Methods: One hundred and sixty-seven students were assigned to team-based or small-group learning for 6 case discussion sessions. Examination

Laura Rees Willett; G. Craig Rosevear; Sarang Kim

2011-01-01

157

Electron cyclotron resonance ion source DECRIS-4 for the U400 cyclotron  

Microsoft Academic Search

The electron cyclotron resonance ion source DECRIS-4 has been designed and constructed at the FLNR to be used as a second injector of heavy multiply charged ions for the U-400 cyclotron. After the modification of the injection side this source can be also used as a ``charge breeder'' (the ``1+-->n+'' method) for the second phase of the Dubna radioactive ion

M. Leporis; V. Bekhterev; S. Bogomolov; A. Efremov; G. Gulbekian; Yu. Kostyukhov; A. Lebedev; V. Loginov; N. Yazvitsky

2006-01-01

158

Beam dynamics in high intensity cyclotrons including neighboring bunch effects: Model, implementation, and application  

NASA Astrophysics Data System (ADS)

Space-charge effects, being one of the most significant collective effects, play an important role in high intensity cyclotrons. However, for cyclotrons with small turn separation, other existing effects are of equal importance. Interactions of radially neighboring bunches are also present, but their combined effects have not yet been investigated in any great detail. In this paper, a new particle in the cell-based self-consistent numerical simulation model is presented for the first time. The model covers neighboring bunch effects and is implemented in the three-dimensional object-oriented parallel code OPAL-cycl, a flavor of the OPAL framework. We discuss this model together with its implementation and validation. Simulation results are presented from the PSI 590 MeV ring cyclotron in the context of the ongoing high intensity upgrade program, which aims to provide a beam power of 1.8 MW (CW) at the target destination.

Yang, J. J.; Adelmann, A.; Humbel, M.; Seidel, M.; Zhang, T. J.

2010-06-01

159

Cyclotron Lines in Accretion Powered Pulsars  

NASA Astrophysics Data System (ADS)

The strong magnetic fields of accretion-powered pulsars give rise to cyclotron resonance scattering features (CRSF), popularly known as "Cyclotron Lines", in their X-ray spectra. The study of the energies and profiles of these lines provide a direct measurement of the magnetic field distribution in the X-ray emitting region. Cyclotron lines have been detected in the spectra of more than two dozen X-ray pulsars till date, but in many of these cases the observations are too sparse to make detailed conclusions. Upcoming X-ray missions such as NuSTAR and ASTROSAT are poised to collect a wealth of new data on the cyclotron features in X-ray binaries. Detailed phase resolved study of these lines can be used to perform a magnetic tomography of the poles of the accreting neutron star. In this talk I will present a short review of the techniques to model the CRSF profiles, followed by a description of the expected distribution of matter density and magnetic field at the polar cap, derived from MHD solutions. I will then discuss the predicted shapes of cyclotron lines from such emitting regions.

Bhattacharya, Dipankar

2012-07-01

160

Recycling and recommissioning a used biomedical cyclotron  

NASA Astrophysics Data System (ADS)

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. .

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

2001-07-01

161

Low energy cyclotron for radiocarbon dating  

SciTech Connect

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

Welch, J.J.

1984-12-01

162

Cyclotron frequency shifts arising from polarization forces  

NASA Astrophysics Data System (ADS)

The cyclotron frequency of a charged particle in a uniform magnetic field B is related to its mass m and charge q by the relationship ?c = qB/m. This simple relationship forms the basis for sensitive mass comparisons using ion cyclotron resonance mass spectroscopy, with applications ranging from the identification of biomolecules and the study of chemical reaction rates to determinations of the fine structure constant of atomic spectra. Here we report the observation of a deviation from the cyclotron frequency relationship for polarizable particles: in high-accuracy measurements of a single CO+ ion, a dipole induced in the orbiting ion shifts the measured cyclotron frequency. We use this cyclotron frequency shift to measure non-destructively the quantum state of the CO+ ion. The effect also provides a means to determine to a few per cent the body-frame dipole moment of CO+, thus establishing a method for measuring dipole moments of molecular ions for which few comparably accurate measurements exist. The general perturbation that we describe here affects the most precise mass comparisons attainable today, with applications including direct tests of Einstein's mass-energy relationship and charge-parity-time reversal symmetry, and possibly the weighing of chemical bonds.

Thompson, James K.; Rainville, Simon; Pritchard, David E.

2004-07-01

163

Radiotracers for medical applications  

Microsoft Academic Search

This book discusses the medical applications of radiotracers. Diagnostic uses and pharmacokinetics of isotopes and radiopharmaceuticals is emphasized. The volume one covers the following topics: Radiohalogenated compounds, including radioiodine; Tc-labeled compounds; and in-house prepared radiopharmaceuticals. The charge particle range vs. energy in every element is tabulated for protons for cyclotrons users. Discussions are also provided on nonimaging radiotracer methods; ¹¹C,

Rayudu; G. A. S

1983-01-01

164

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

ERIC Educational Resources Information Center

|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…

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

2012-01-01

165

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

Microsoft Academic Search

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 transportation to a hospital ED and the reported blood alcohol content

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

2012-01-01

166

Problems of high efficient extraction from the isochronous cyclotron.  

National Technical Information Service (NTIS)

The problem of high efficient extraction ((eta) (>=) 50%) from isochronous cyclotrons (with the exception of the stripping method) is not completely solved up to this day. This problem is specifically important, because these cyclotrons are being also app...

J. Schwabe

1994-01-01

167

Analysis of gamma ray burst spectra with cyclotron lines.  

National Technical Information Service (NTIS)

Motivated by the recent developments in the cyclotron resonance upscattering of soft photons or CUSP model of Gamma Ray Burst (GRB) continuum spectra, we revisit a select database of GRBs with credible cyclotron absorption features. We measure the break e...

V. Kargatis E. P. Liang

1990-01-01

168

Cyclotron maser emission: Stars, planets, and laboratory  

NASA Astrophysics Data System (ADS)

This paper is a review of results by the group over the past decade on auroral kilometric radiation and similar cyclotron emissions from stars and planets. These emissions are often attributed to a horseshoe or crescent shaped momentum distribution of energetic electrons moving into the convergent magnetic field which exists around polar regions of dipole-type stars and planets. We have established a laboratory-based facility that has verified many of the details of our original theoretical description and agrees well with numerical simulations. The experiment has demonstrated that the horseshoe distribution does indeed produce cyclotron emission at a frequency just below the local cyclotron frequency, with polarization close to X-mode and propagating nearly perpendicularly to the beam motion. We discuss recent developments in the theory and simulation of the instability including addressing a radiation escape problem and the effect of competing instabilities, relating these to the laboratory, space, and astrophysical observations.

Vorgul, I.; Kellett, B. J.; Cairns, R. A.; Bingham, R.; Ronald, K.; Speirs, D. C.; McConville, S. L.; Gillespie, K. M.; Phelps, A. D. R.

2011-05-01

169

Estimated leakage radiation from Inshas Cyclotron  

NASA Astrophysics Data System (ADS)

Inshas Cyclotron is a K=20 AVF cyclotron of MGC-20 type with maximum iternal/external parameters for protons Emax=20/18 MeV, Imax=200/50 ?A. The cyclotron machine is situated in a vault followed by 5 radiation shielded experimental halls. The shielded area was designed at the aim that operation with ion beam in a hall does not prevent work in adjacent hall(s) and outside. The layout of the facility is given with emphasis on mazes and sliding doors. The leakage radiation from thick shields and mazes is estimated. Methods of calculation based on engineering approach are used. Obtained results are given and are to be verified based on actual radiation situation during accelerator operation at the rated parameters.

Comsan, M. N. H.

1999-06-01

170

Cyclotron maser emission: Stars, planets, and laboratory  

SciTech Connect

This paper is a review of results by the group over the past decade on auroral kilometric radiation and similar cyclotron emissions from stars and planets. These emissions are often attributed to a horseshoe or crescent shaped momentum distribution of energetic electrons moving into the convergent magnetic field which exists around polar regions of dipole-type stars and planets. We have established a laboratory-based facility that has verified many of the details of our original theoretical description and agrees well with numerical simulations. The experiment has demonstrated that the horseshoe distribution does indeed produce cyclotron emission at a frequency just below the local cyclotron frequency, with polarization close to X-mode and propagating nearly perpendicularly to the beam motion. We discuss recent developments in the theory and simulation of the instability including addressing a radiation escape problem and the effect of competing instabilities, relating these to the laboratory, space, and astrophysical observations.

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

2011-05-15

171

Improving cancer treatment with cyclotron produced radionuclides  

SciTech Connect

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

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

1992-08-04

172

Radioisotope production at the Kazakhstan cyclotron  

Microsoft Academic Search

Cyclotrons play an important role for production of carrier-free radioisotopes for various applications in the nuclear medicine, industry, ecology and science. Kazakhstan variable energy isochronous cyclotron, K = 50 MeV, is a 150 cm compact-pole 3 sector positive ion machine. It generates different beams of light ions: protons 6-30 MeV, deuterons 12.5-25 MeV, 3He-ions 18.5-62 MeV, alpha-particles 25-50 MeV. In

A. Arzumanov; V. Batischev; N. Berdinova; A. Borissenko; G. Chumikov; N. Gorodisskaya; A. Knyazev; V. Koptev; S. Lyssukhin; Yu. Popov; G. Sychikov; D. Zheltov

2003-01-01

173

Transmission characteristics of cyclotron harmonic waves in plasma  

Microsoft Academic Search

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

F. W. Crawford; H. H. Weiss

1966-01-01

174

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

NASA Astrophysics Data System (ADS)

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

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

2001-12-01

175

Cyclotron braid group structure for composite fermions  

NASA Astrophysics Data System (ADS)

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).

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

2010-09-01

176

Electron-cyclotron-resonance ion sources (review)  

SciTech Connect

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

Golovanivskii, K.S.; Dougar-Jabon, V.D. [People`s Friendship Univ., Moscow (Russian Federation)

1992-01-01

177

Cyclotron Axial Ion-Beam-Buncher System.  

National Technical Information Service (NTIS)

Adiabatic ion bunching is achieved in a cyclotron axial ion injection system through the incorporation of a radio frequency quadrupole system, which receives ions from an external ion source via an accelerate-decelerate system and a focusing einzel lens s...

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

1982-01-01

178

Comparison between californium and cyclotron SEU tests  

Microsoft Academic Search

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

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

1990-01-01

179

On Resonant Heating Below the Cyclotron Frequency  

SciTech Connect

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.

Liu Chen; Zhihong Lin; White, R.

2001-02-02

180

Fluid model of electron cyclotron current drive  

SciTech Connect

A macroscopic model is proposed to describe the dynamics of electron cyclotron current drive (ECCD). This model depends on the adoption of a suitable distribution function for the energetic current-carrying electrons. The model is readily applied to examine the current drive efficiency of high-power ECCD experiments, reproducing the main experimental features.

Ludwig, G. O. [Associated Plasma Laboratory, National Space Research Institute 12227-010 Sao Jose dos Campos, SP (Brazil)

2008-04-07

181

Comparison between californium and cyclotron SEU tests  

NASA Astrophysics Data System (ADS)

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

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

182

Numerical investigation of auroral cyclotron maser processes  

SciTech Connect

When a mainly rectilinear electron beam is subject to significant magnetic compression, conservation of magnetic moment results in the formation of a horseshoe shaped velocity distribution. It has been shown that such a distribution is unstable to cyclotron emission and may be responsible for the generation of auroral kilometric radiation--an intense rf emission sourced at high altitudes in the terrestrial auroral magnetosphere. Particle-in-cell code simulations have been undertaken to investigate the dynamics of the cyclotron emission process in the absence of cavity boundaries with particular consideration of the spatial growth rate, spectral output and rf conversion efficiency. Computations reveal that a well-defined cyclotron emission process occurs albeit with a low spatial growth rate compared with waveguide bounded simulations. The rf output is near perpendicular to the electron beam with a slight backward-wave character reflected in the spectral output with a well defined peak at 2.68 GHz, just below the relativistic electron cyclotron frequency. The corresponding rf conversion efficiency of 1.1% is comparable to waveguide bounded simulations and consistent with the predictions of kinetic theory that suggest efficient, spectrally well defined emission can be obtained from an electron horseshoe distribution in the absence of radiation boundaries.

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

2010-05-15

183

Ion-cyclotron instability in magnetic mirrors  

SciTech Connect

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

Pearlstein, L.D.

1987-02-02

184

Proton cyclotron waves at mars and venus  

Microsoft Academic Search

Proton cyclotron waves were discovered by the Phobos magnetic field investigation upstream of the Mars bow shock. These waves have also been detected by the MGS magnetometer and more extensively mapped with its much longer database. The waves are very common and extend well into the solar wind on either side of the bow shock indicating that a very large

C. T. Russell; S. Mayerberger; X. Blanco-Cano

2004-01-01

185

Development of an Accelerator Mass Spectrometer based on a Cyclotron  

NASA Astrophysics Data System (ADS)

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 ° 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.

Kim, Dogyun; Bhang, Hyeongchan; Kim, Jongwon

2011-12-01

186

Development of an Accelerator Mass Spectrometer based on a Cyclotron  

SciTech Connect

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.

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

187

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

SciTech Connect

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.

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

188

A high resolution Small Field Of View (SFOV) gamma camera: a columnar scintillator coated CCD imager for medical applications  

NASA Astrophysics Data System (ADS)

We describe a high resolution, small field of view (SFOV), Charge Coupled Device (CCD) based camera for imaging small volumes of radionuclide uptake in tissues. The Mini Gamma Ray Camera (MGRC) is a collimated, scintillator-coated, low cost, high performance imager using low noise CCDs. The prototype MGRC has a 600 ?m thick layer of columnar CsI(Tl) and operates in photon counting mode using a thermoelectric cooler to achieve an operating temperature of - 10°C. Collimation was performed using a pin hole collimator. We have measured the spatial resolution, energy resolution and efficiency using a number of radioisotope sources including 140 keV gamma-rays from 99mTc in a specially designed phantom. We also describe our first imaging of a volunteer patient.

Lees, J. E.; Bassford, D. J.; Blake, O. E.; Blackshaw, P. E.; Perkins, A. C.

2011-12-01

189

Optimization of A Commercial PET Cyclotron For Increased 18F- Production  

SciTech Connect

Commercial cyclotron systems used for 18F- production through 18O (p, n) 18F reaction face several conflicting requirements that include: reliability/uptime, quantity of consumables, safety, cost and yield. With commercialization of PET tracer distribution, higher yield has become one of the most important requirements. Maximizing yield for commercial cyclotrons require engineering trade-off amongst several requirements, and often, to be conservative, significant design margin is kept while field feedback is collected. With maturing of technology, substantial experience has been obtained for a commercial cyclotron (PETtrace, GE Medical Systems), which is in use for several years. In this paper, we describe key elements of PETtrace commercial cyclotron technology undergoing enhancements, and share our works-in-progress experiments in performing critical engineering trade-offs to improve 18F- yield. Three key parameters were tuned in this study within the design margin of the current equipment. First, we designed a second-generation target assembly with optimized 18O water volume for accepting increased beam currents while maintaining cooling performance. Second, we increased the beam current of the ion source. And finally, a new RF driver amplifier was designed to enhance the RF power ratings to enable higher beam currents. Initial tests performed in the factory indicate substantially higher yield performance (> 50%) reaching a peak yield of over 4 Ci per hour of bombardment in the new target. On dual targets, this extrapolates to 13.5 Ci/2hr of bombardment for a total target current of 120 {mu}A. A target current of 100 {mu}A is available in the existing design thus providing an 18F- production capacity exceeding 11 Ci/2hr. The preliminary experimental results are promising and illustrate successful exploitation of design margin to achieve increased yield for a commercial cyclotron. Long-term studies to assess impact on life of ion source are underway along with a dedicated effort for achieving target currents in the excess of 120{mu}A.

Bergstrom, Jan Olof; Eriksson, Tomas [GE Medical System, Uppsala (Sweden)

2003-08-26

190

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

NASA Astrophysics Data System (ADS)

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

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

2003-08-01

191

Electron-cyclotron wave scattering by edge density fluctuations in ITER  

SciTech Connect

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

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

2009-11-15

192

Extending the feasibility boundary of the isochronous cyclotron  

NASA Astrophysics Data System (ADS)

A number of recent design innovations have made the isochronous cyclotron a design option for applications that were previously considered best served by other types of accelerators. Several such proposed and existing applications of cyclotron technology are described. To provide a basis for these reviews the general characteristics of the isochronous cyclotron are summarized, including investigations of improved methods of computer simulations of cyclotron features. The possibility of reducing cyclotron size and cost by raising the maximum magnetic field from 5 to 8 tesla has been studied; the magnetic and electric fields for such an ultra compact cyclotron have been simulated and beam quality satisfactory for applications in nuclear physics is indicated. The feasibility of a cyclotron based accelerator mass spectrometry (AMS) program at the National superconducting Cyclotron Laboratory (NSCL) has also being studied; a feasibility example of an inexpensive high resolution AMS cyclotron is developed based on the use of an existing magnet and scaling from the handful of existing designs. A review of the central region of the first commercial 235 MeV proton cyclotron for cancer therapy is presented; orbit studies are summarized and an improved central region is discussed.

Schubert, Jeffrey R.

193

Ion Cyclotron Resonance Heating on TEXTOR  

SciTech Connect

The original work done on TEXTOR on ion cyclotron resonance heating of the plasma is reviewed. After a brief introduction outlining the principles, the radio-frequency (rf) system is described, with its substantial evolution during time. Then, the different physics results are reviewed. Ion cyclotron heating has been performed in a large number of scenarios and under a wide range of conditions. Aside from the various minority or mode-conversion scenarios, the interaction with beam ions and the possibility of controlling fast-ion diffusion with rf have been deeply investigated. Both the interaction with the wall or edge plasma and the impact on improved core confinement were studied in detail. Pioneering work was done to demonstrate efficient heating with unshielded antennas and plasma production in a tokamak by rf alone for plasma startup assistance or wall conditioning.

Koch, R.; Dumortier, P.; Durodie, F.; Huygen, S.; Lyssoivan, A.; Messiaen, A.M.; Vandenplas, P.E.; Wassenhove, G. van; Vervier, M.; Weynants, R.R

2005-02-15

194

Applications of cyclotron based ion scattering  

NASA Astrophysics Data System (ADS)

Ion scattering experiments have been performed with a 3-30 MeV AVF cyclotron. The wide range of available energies combined with proper beam handling allows many scattering techniques to perform. At first an example of ordinary Rutherford backscattering spectrometry will be demonstrated on model catalysts as studied in surface chemistry. High energy backscattering spectrometry with 8.8 MeV He ions, which enhances the sensitivity for oxygen, has been applied to study the oxygen removal from corroded archaeological artefacts upon treatment with a H2 plasma. Elastic recoil detection analysis will be shown feasible with He ions having incident energies between 10 and 15 MeV once combined with a thin film detector. The development of a setup for ion channeling experiments with the cyclotron is reported and first results promise to increase the angular resolution in lattice deformation studies.

van Ijzendoorn, L. J.; Niemantsverdriet, J. W.; Severens, R. J.; van Dijk, P. W. L.; de Voigt, M. J. A.

1994-05-01

195

Acceleration system for the RCNP ring cyclotron  

SciTech Connect

A variable frequency H/sub 101/ mode single-gap cavity has been made for the RCNP ring cyclotron. The frequency range is 22 to 33 MHz. Radially increasing voltage distributions of the acceleration system produce beam phase compression ratio of about 3. The cavity was excited up to 270 kV at 33 MHz in a preliminary test. A 20 inch cryopump evacuated the aluminium cavity chamber down to 1 X 10/sup -7/ Torr.

Saito, T.; Inoue, M.; Itahashi, T.; Mivra, I.; Shimizu, A.; Tamura, H.

1985-10-01

196

The Jyvaskyla (Finland) K130 cyclotron project  

NASA Astrophysics Data System (ADS)

Tests and delivery dates of the components and cyclotron building and installation are given. A vacuum level of 0.00002 Pa was obtained after 200 hours pumping of the vacuum chamber. After venting with nitrogen the vacuum level of 0.0001 Pa was achieved. The specified level of 0.00001 Pa could not be achieved. It is possible that first experiments can be run just before the end of the year 1992.

Liukkonen, Esko

197

Creep of Aluminum under Cyclotron Irradiation  

Microsoft Academic Search

The effect of cyclotron irradiation by 38-Mev alpha particles on the steady-state creep rate (ca 10?6 per second) of aluminum has been measured at beam densities up to 1.2×1013 particles per cm2 per second. The data, which were taken on a 0.016-inch thick aluminum specimen for a stress range of 600 to 2500 psi and over a temperature range of

M. R. Jeppson; R. L. Mather; A. Andrew; H. P. Yockey

1955-01-01

198

Cyclotron Requirements for Multi-disciplinary Programs  

NASA Astrophysics Data System (ADS)

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.

Armbruster, John M.

2009-03-01

199

Cyclotron Requirements for Multi-disciplinary Programs  

SciTech Connect

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.

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

2009-03-10

200

Ion cyclotron waves in Io's wake region  

NASA Astrophysics Data System (ADS)

When Galileo flew almost directly through the center of Io's wake in December 1995 it encountered a region of depressed field strength, devoid of the strong ion cyclotron waves that were present inbound and outbound on either side of the wake. In August 2001 Galileo made an almost orthogonal pass, parallel to the wake axis, passing within 200 km of the Io surface, and staying close to 1 RIo above the center of the wake. Downstream from Io (but not upstream) strong ion cyclotron waves were seen. The very low frequency of these waves, well below the local SO 2+ gyro frequency, suggests that they were created in the low field of Io's wake. Thus in contrast to implications of the December 1995, near-Io, wake passage, ion cyclotron waves are produced in the Io wake. Furthermore, these waves persisted beyond 6.7 RIo downstream, with little sign of recovery in frequency, indicating that Io's depressed field wake extends well downstream of Io.

Russell, C. T.; Blanco-Cano, X.; Kivelson, M. G.

2003-03-01

201

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

Microsoft Academic Search

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

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

1998-01-01

202

Temperature control of a cyclotron magnet for stabilization of the JAERI AVF cyclotron beam  

NASA Astrophysics Data System (ADS)

Frequent corrections of the magnetic field of the JAERI AVF cyclotron were required for keeping a beam current constant during long time operation. We observed correlation between the magnetic field and the temperature of the cyclotron magnet yoke by measuring the magnetic field with an NMR probe and the temperature with platinum resistance thermometers. As a result, this instability of a cyclotron beam was induced by temperature-change of the magnet yoke caused mainly by thermal conduction from the main coil. To restrain the thermal conduction to the yoke, we have inserted temperature-controlled copper plates between the yoke and the main coil. In addition, a temperature control system for the cooling water of the trim coils has been installed, which is independent of the total cooling system for controlling the pole tip temperature. An optimum condition of the temperature control systems for stabilizing the magnetic field has been investigated. .

Okumura, S.; Arakawa, K.; Fukuda, M.; Nakamura, Y.; Yokota, W.; Ishimoto, T.; Kurashima, S.; Ishibori, I.; Nara, T.; Agematsu, T.; Tamura, H.; Matsumura, A.; Sano, M.; Tachikawa, T.

2001-12-01

203

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

PubMed Central

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

Chang, Joe Y.; Komaki, Ritsuko; Wen, Hong Y.; De Gracia, Beth; Bluett, Jaques B.; McAleer, Mary F.; Swisher, Stephen G.; Gillin, Michael; Mohan, Radhe; Cox, James D.

2011-01-01

204

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

Federal Register 2010, 2011, 2012, 2013

...License Nos. 052-31352-01MD/52- 31352-02; EA-11-086; NRC-2011-0292] International Cyclotron, Inc., Hato Rey, Puerto Rico; Order Suspending Licensed Activities I International Cyclotron, Inc. (International Cyclotron;...

2011-12-27

205

Fundamental ion cyclotron resonance heating of JET deuterium plasmas  

SciTech Connect

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.

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

206

Is radiofrequency ablation more effective than stereotactic ablative radiotherapy in patients with early stage medically inoperable non-small cell lung cancer?  

PubMed Central

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was ‘is radiofrequency ablation more effective than stereotactic ablative radiotherapy in patients with early stage medically inoperable non-small cell lung cancer?’ Altogether, over 219 papers were found, of which 16 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Radiofrequency ablation (RFA) and stereotactic ablative radiotherapy (SABR) offer a clear survival benefit compared with conventional radiotherapy in the treatment of early stage non-small cell lung cancer (NSCLC) in medically inoperable patients. Overall survival at 1 year (68.2–95% vs. 81–85.7%) and 3 years (36–87.5% vs. 42.7–56%) was similar between patients treated with RFA and SABR. However, 5-year survival was higher in SABR (47%) than RFA (20.1–27%). Local progression rates were lower in patients treated with SABR (3.5–14.5% vs. 23.7–43%). Both treatments were associated with complications. Pneumothorax (19.1–63%) was the most common complication following RFA. Fatigue (31–32.6%), pneumonitis (2.1–12.5%) and chest wall pain (3.1–12%) were common following SABR. Although tumours ?5 cm in size can be effectively treated with RFA, results are better for tumours ?3 cm. One study documented increased recurrence rates with larger tumours and advanced disease stage following RFA. Another study found increasing age, tumour size, previous systemic chemotherapy, previous external beam radiotherapy and emphysema increased the risk of toxicity following SABR and suggested that risk factors should be used to stratify patients. RFA can be performed in one session, whereas SABR is more effective if larger doses of radiation are given over two to three fractions. RFA is not recommended for centrally based tumours. Patients with small apical tumours, posteriorly positioned tumours, peripheral tumours and tumours close to the scapula where it may be difficult to position an active electrode are more optimally treated with SABR. Treatment for early stage inoperable NSCLC should be tailored to individual patients, and under certain circumstances, a combined approach may be beneficial.

Bilal, Haris; Mahmood, Sarah; Rajashanker, Bala; Shah, Rajesh

2012-01-01

207

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  

Microsoft Academic Search

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

Mark A. Henderson; David J. Hoopes; James W. Fletcher; Pei-Fen Lin; Mark Tann; Constantin T. Yiannoutsos; Mark D. Williams; Achilles J. Fakiris; Ronald C. McGarry; Robert D. Timmerman

2010-01-01

208

Backward branch of surface dust cyclotron wave in a semi-bounded magnetized dusty plasma  

SciTech Connect

The surface dust cyclotron waves are investigated in semi-bounded magnetized dusty plasmas. The dispersion relation is obtained by the plasma dielectric function with the specular reflection boundary condition. The result shows the existence of the low-frequency backward wave branch in the surface dust cyclotron wave. The frequency of the wave is found to be decreased with the dust Debye wave number. It is also found that there is a minimum position of the scaled group velocity in the small-wave-number region. It is interesting to note that the group velocity increases below the minimum position and, however, decreases above the minimum position with increasing the dust Debye wave number.

Chang, Won-Seok; Chang, Dong-Man; Jung, Iyoung Michelle; Jung, Young-Dae [Department of Applied Physics, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Hanyoung Foreign Language High School, Seoul 134-837 (Korea, Republic of); Department of Applied Physics and Institute of Natural Science and Technology, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of)

2006-01-15

209

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

SciTech Connect

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.

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

210

[Electron cyclotron resonance (ECR) plasma film deposition  

SciTech Connect

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

NONE

1999-04-01

211

Electromagnetic Ion Cyclotron Fluctuations and Fast Electron Scattering: Hybrid Simulations  

Microsoft Academic Search

Two dimensional electromagnetic hybrid simulations in a magnetized, homogeneous, collisionless plasma with a single ion species yield enhanced electromagnetic ion cyclotron (EMIC) fluctuations due to the growth of the ion cyclotron instability driven by T? i > T|| i. The research described here addresses fundamental properties of such enhanced fluctuations, in preparation for future studies on their interaction with fast

D. Winske; S. P. Gary

2008-01-01

212

Fundamental ion cyclotron resonance heating of JET deuterium plasmas  

Microsoft Academic Search

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

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

213

The TRIUMF 500 MeV cyclotron: the driver accelerator  

NASA Astrophysics Data System (ADS)

ISAC's radioactive ion beams are currently produced in nuclear spallation reactions driven by an intense 480-MeV proton beam from the TRIUMF sector-focused cyclotron. In this article we describe the design and operation of the cyclotron, and also the extensive program of upgrading the equipment and beams that has enhanced its performance and reliability over recent years.

Bylinskii, I.; Craddock, M. K.

2013-10-01

214

The spectral emissivity at the electron cyclotron frequency  

Microsoft Academic Search

Attention is given to the work of Audenaerde (1976, 1977) concerning electron cyclotron radiation from a stationary, quasi-homogeneous plasma of arbitrary density. As an extension of this study, the spectral emissivity in a magnetized plasma at frequencies close to the electron cyclotron frequency is calculated. Values are found for waves both parallel and perpendicular to the static magnetic field.

K. Audenaerde; C. M. Celata

1978-01-01

215

Cyclotron resonance effects on stochastic acceleration of light ionospheric ions  

NASA Astrophysics Data System (ADS)

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.

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

1982-09-01

216

Ion Cyclotron Waves in the VASIMR  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

217

Electron Cyclotron Resonance Heating on TEXTOR  

SciTech Connect

TEXTOR is equipped with two gyrotrons at 110 and 140 GHz, respectively. Both share a single power supply and a confocal quasi-optical transmission line. They cannot be operated simultaneously. The 110-GHz gyrotron with limited power and pulse length (300 kW; 200 ms) has been used in a first series of experiments on electron cyclotron resonance heating (ECRH) and electron cyclotron current drive (ECCD) and for collective Thomson scattering (CTS) diagnostics of energetic ions. In the future the 110-GHz gyrotron will be operated exclusively for CTS diagnostics, while for ECRH and ECCD, the newly installed 140-GHz, high-power (800-kW), long-pulse (>3-s) gyrotron is now available. The highlights of first ECRH experiments with the 110-GHz gyrotron are reported. These include observations of internal transport barriers with ECRH on various target plasmas: in the current plateau phase of both ohmic and radiation improved mode (RI-mode) discharges. In addition, sawtooth control by localized ECRH is demonstrated. First results on CTS include the observation of the slowing down of energetic ions and of the redistribution of energetic ions in sawtooth crashes.

Westerhof, E. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM (Netherlands); Hoekzema, J.A. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, EURATOM Association (Germany); Hogeweij, G.M.D. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM (Netherlands)] (and others)

2005-02-15

218

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

SciTech Connect

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.

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

219

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

SciTech Connect

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

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

2012-12-19

220

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

NASA Astrophysics Data System (ADS)

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 C60 ion beam production.

Uchida, T.; Minezaki, H.; Tanaka, K.; Muramatsu, M.; Asaji, T.; Kato, Y.; Kitagawa, A.; Biri, S.; Yoshida, Y.

2010-02-01

221

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

SciTech Connect

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

Krasilnikov, A. V.; Kaschuck, Yu. A.; Amosov, V. N. [SRC RF Troitsk Institute for Innovating and Fusion Research, Troitsk (Russian Federation); Van Eester, D.; Lerche, E. [Laboratory for Plasma Physics--ERM/KMS, TEC partner, Brussels (Belgium); Ongena, J.; Bonheure, G. [Laboratory for Plasma Physics--ERM/KMS, TEC partner, Brussels (Belgium); Euratom-UKAEA Fus. Assoc., Culham Science Center (United Kingdom); Mailloux, J.; Stamp, M.; Jachmich, S.; Leggate, H.; Walden, A.; Mayoral, M.-L.; Santala, M.; Kiptily, V.; Popovichev, S. [Euratom-UKAEA Fus. Assoc., Culham Science Center (United Kingdom); Vdovin, V. [RNC Kurchatov Institute, Nuclear Fusion Institute, Moscow (Russian Federation); Biewer, T. [Euratom-UKAEA Fus. Assoc., Culham Science Center (United Kingdom); Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Crombe, K. [Euratom-UKAEA Fus. Assoc., Culham Science Center (United Kingdom); Department of Applied Physics, Ghent University, Gent (Belgium); Esposito, B. [ENEA, Frascati (Italy)] (and others)

2007-09-28

222

The Flux Control of Cyclotron Ions Incident upon the Substrate by Employing the Ponderomotive Potential  

NASA Astrophysics Data System (ADS)

The plasma-assisted deposition is desirable processing technique to grow the epitaxial film such as oxide-metal compound semiconductor on the lower temperature substrate. To control its stoichiometry ratio and orientation more precisely, handling the flux of oxygen and metallic ions incident upon the substrate is required. Here, we propose to employ the ponderomotive potential acting independently on each species of cyclotron ions in order to govern a new method for the flux control of ions selected before the substrate. Our idea is to form the potential structure decelerating the ions before the substrate, resulting in the enhancement of the ponderomotive force on their ions. The preliminary experiment is carried out using the magnetized plasma column terminated by the floating substrate where the localized rotating electrostatic field yielding the ponderomotive potential is impressed. It is found that the ion flux decreases when rf frequency approaches to the cyclotron frequency of helium ion. However, Q-value is small because the ions would not make the cyclotron motion many times until arriving at the substrate. In order to decelerate ions, we try to form the potential hump and/or to reconstruct the ion sheath to the effective electron sheath by the ponderomotive potential.

Sato, Naoyuki; Nakamori, Hidetaka; Ikehata, Takashi; Mase, Hiroshi

2000-10-01

223

Electromagnetic Ion Cyclotron Waves in the Helium Branch Induced by Multiple Electromagnetic Ion Cyclotron Triggered Emissions  

NASA Astrophysics Data System (ADS)

Electromagnetic ion cyclotron (EMIC) triggered emissions with rising tones between the H+ and He+ cyclotron frequencies were found in the inner magnetosphere by the recent Cluster observations. Another type of EMIC wave with a constant frequency is occasionally observed below the He+ cyclotron frequency after the multiple EMIC triggered emissions. We performed a self-consistent hybrid simulation with a one-dimensional cylindrical magnetic flux model approximating the dipole magnetic field of the Earth's inner magnetosphere. In the presence of energetic protons with a sufficient density and temperature anisotropy, multiple EMIC triggered emissions are reproduced due to the nonlinear wave growth mechanism of rising-tone chorus emissions, and a constant frequency wave in the He+ EMIC branch is subsequently generated. Through interaction with the multiple EMIC rising-tone emissions, the velocity distribution function of the energetic protons is strongly modified. Because of the pitch angle scattering of the protons, the gradient of the distribution in velocity phase space is enhanced along the diffusion curve of the He+ branch wave, resulting in the linear growth of the EMIC wave in the He+ branch.

Shoji, M.; Omura, Y.; Grison, B.; Pickett, J. S.; Dandouras, I. S.; Engebretson, M. J.

2011-12-01

224

Folded waveguide coupler for ion cyclotron heating  

SciTech Connect

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

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

1986-01-01

225

Electron Cyclotron Heating in RFP plasmas  

NASA Astrophysics Data System (ADS)

Reversed field pinches (RFP) plasmas are typically overdense (?pe>?ce) and thus not suitable for conventional electron cyclotron (EC) heating and current drive. In recent high plasma current discharges (Ip>1.5 MA), however, the RFX-mod device was operated in underdense conditions (?pe

Bilato, R.; Volpe, F.; Poli, E.; Köhn, A.; Cavazzana, R.; Paccagnella, R.; Farina, D.

2009-11-01

226

Simulation of electron cyclotron heating in TFR  

NASA Astrophysics Data System (ADS)

A high power (over 500 kW) electron cyclotron heating (ECH) experiment was carried out. Bulk heating experiments were analyzed by one dimensional transport code simulations. All experimental regimes are addressed, concentrating on global properties and trends of discharges in the different regimes instead of simulating one particular discharge. A regime with good confinement is found for low plasma currents. At higher currents lower confinement times are found and a high level of MHD activity (mainly m=2, 3) is observed. When ECH is applied, these regimes converge, i.e., even at low ECH powers the confinement in the low current regime is strongly degraded and approaches that of the high current regime. During part of the experiment a calorimeter was mounted in the shadow of the limiter. This gave a high level of metallic impurities. Under these conditions the confinement is slightly worse than in the high current regime and no dependence on current is found.

Westerhof, E.

1987-08-01

227

Cyclotron-based high energy ion channeling  

NASA Astrophysics Data System (ADS)

Ion channeling for materials analysis is usually carried out with He ion beam energies less than 3MeV. The AVF-cyclotron at Eindhoven University of Technology allows the use of higher beam energies (3-30MeV) which is of potential interest due to a high angular resolution, a large analysable depth range and the application of nuclear reactions or resonant scattering cross-sections. In this paper the enhanced angular resolution for 12.6MeV He ions is demonstrated by angular scans from a buried Si1-xGex layer. The enhanced analysable depth range is shown by quantitative defect depth profiling of a 4?m thick relaxed SiGe multilayer buffer. Finally, a study on vibrational amplitudes in bulk InP was carried out by a combination of channeling and nuclear reaction analysis using the 31P(?,p)34S reaction.

van Ijzendoorn, L. J.; van Dijk, P. W. L.; de Voigt, M. J. A.

1998-03-01

228

Cyclotron maser radiation from inhomogeneous plasmas  

SciTech Connect

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.

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

229

Superconducting cyclotron and its vacuum system  

NASA Astrophysics Data System (ADS)

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.

Sur, A.; Bhandari, R. K.

2008-05-01

230

Accelerators for hadrontherapy: From Lawrence cyclotrons to linacs  

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

231

Positron emission isotope production cyclotron in DLNP JINR (Status Report)  

NASA Astrophysics Data System (ADS)

A C10-cyclotron for radioisotope production is under construction at the Dzhelepov Laboratory of Nuclear Problem, Joint Institute for Nuclear Research (DLNP JINR). It is a compact isochronous cyclotron for accelerating H- ions to the energy of about 10 MeV. The magnetic system, vacuum chamber and accelerating system is being built now. Results of the calculation and forming of the cyclotron magnetic field and the study of the beam dynamics from an ion source to an extraction system in calculated magnetic field are presented.

Alenitsky, Yu. G.; Denisov, Yu. N.; Chesnov, A. F.; Glazov, A. A.; Gurskiy, S. V.; Karamysheva, G. A.; Kostromin, S. A.; Morozov, N. A.; Romanov, V. M.; Samsonov, E. V.; Tolstoi, N. S.; Zaplatin, N. L.

2008-12-01

232

Improving cancer treatment with cyclotron produced radionuclides. Progress report  

SciTech Connect

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

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

1993-11-01

233

Recent advances in medical radionuclide production and future perspective of compact medical cyclotrons  

Microsoft Academic Search

In recent years, many radiopharmaceuticals bearing different kind of radionuclides have been largely used in diagnostic and therapeutic studies, especially of cancer. The basic principle of radiodiagnosis and raditherapy is ensuring as low as radiation dose absorption by patients. Sometimes, the radionuclides having very short half-lives, and very interesting decay characteristics are required for this purpose. The use of short-lived

Turan Ünak

2000-01-01

234

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

SciTech Connect

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.

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

235

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

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.

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

236

Medical treatment of advanced non-small cell lung cancer in elderly patients: A review of the role of chemotherapy and targeted agents.  

PubMed

Lung cancer is the leading cause of cancer related mortality worldwide. Non-small cell lung cancer (NSCLC) accounts for 85% of all cases. Half of the patients at diagnosis of NSCLC are over seventy years old; therefore, the elderly represent a large subgroup of patients affected by advanced NSCLC in our clinical practice. Nevertheless, the elderly are under-represented in clinical trials. Given the fact that old age is frequently associated with several comorbidities, poor general conditions and physiologic reduction in organ function, clinicians must carefully choose the best treatment option for elderly patients with advanced NSCLC, always taking into account the expected risks and benefits. In this paper we perform a review of literature evidence regarding the medical treatment of elderly patients affected by advanced NSCLC, encompassing single-agent chemotherapy, doublet chemotherapy and targeted agents. We conclude that single-agent chemotherapy with a third generation agent (vinorelbine, taxanes, gemcitabine) represents a valid treatment option for elderly patients who are not eligible for a combination chemotherapy due to clinical features such as comorbidities, poor performance status and inadequate organ function. Platinum-based doublet chemotherapy shows similar efficacy in elderly patients as compared to their younger counterpart, despite greater treatment related toxicity and it is indicated in elderly patients with ECOG PS: 0-2, adequate organ function and no major comorbidities. Elderly patients affected by epidermal growth factor receptor (EGFR) mutated NSCLC benefit mostly from a tyrosine kinase inhibitor of EGFR (erlotinib, gefitinib) which is associated with a good toxicity profile. Currently there are no available data to strongly support the use of bevacizumab in combination with first line chemotherapy in the treatment of older adults. Elderly patients affected by NSCLC harboring the EML4-ALK translocation could benefit mostly from a treatment with an oral inhibitor of such a rearrangement (crizotinib). PMID:24070465

Meoni, Giulia; Cecere, Fabiana Letizia; Lucherini, Elisa; Di Costanzo, Francesco

2013-05-07

237

Currents induced in tokamaks by electron cyclotron heating  

SciTech Connect

Generation of a plasma current is predicted in association with strong electron cyclotron heating in tokamaks or in any plasma with transverse magnetic field gradients. The current predicted in present-day tokamaks is of the order of one-quarter ampere per watt, which is large enough to be detected in heating experiments in progress. The current scales linearly with electron temperature and heating power and inversely with density and major radius. The mechanism depends on the Doppler shift for electrons streaming along magnetic field lines. Electrons streaming toward the source of radiation are resonant at a larger magnetic field. When the interaction is strong, radiation incident from the high field side is absorbed before reaching the cold electron resonant surface, and, so, a unidirectional population of electrons is heated. The anisotropic electron distribution gains momentum by collisions with ions. For small tokamaks the extraordinary wave should be launched for current drive, but for reactors the ordinary wave produces a sufficiently strong interaction.

Eldridge, O. C.

1980-10-01

238

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

NASA Astrophysics Data System (ADS)

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

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

2008-09-01

239

Stripper foil mechanism for the K1200 superconducting cyclotron  

NASA Astrophysics Data System (ADS)

The Coupled Cyclotron Facility at MSU comprises two superconducting cyclotrons, the K500 (injector) and the K1200 (booster). Both cyclotrons are of the compact design with three hills and three dees in the valleys. The beam from the K500 is injected in the K1200 and stripped to a high charge state inside one of the dees of the cyclotron. The stripper mechanism consists of 31 foil holders attached to a bicycle chain, mounted on a moving platter. A complicated design was necessary to fit all the hardware necessary to do foil exchange in the tight space inside the dee. Five different hydraulic cylinders move the foil to the stripping position, exchange foils within the stripper chain, and position the foils in the loading position. We describe in the paper the mechanical design as well as the control programs developed for it. .

Bonofiglio, J.; Alfredson, S.; Hitchcock, S.; Marti, F.; Rodriguez, A.; Stork, G.

2001-12-01

240

Maser Cyclotron Instability in a Plasma with Anisotropic Distribution Function.  

National Technical Information Service (NTIS)

Electron cyclotron absorption and emission, with allowance for the relativistic effects for propagation along the magnetic field in a plasma with arbitrary refraction index N and anisotropic distribution function of electrons is investigated. This questio...

V. G. Bezchastanov G. G. Pavlov

1990-01-01

241

Cyclotrons for Clinical and Biomedical Research with PET.  

National Technical Information Service (NTIS)

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

A. P. Wolf

1987-01-01

242

Design Study Of Cyclotron Magnet With Permanent Magnet  

SciTech Connect

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.

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

243

Cyclotrons for clinical and biomedical research with PET  

SciTech Connect

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

Wolf, A.P.

1987-01-01

244

Bernstein mode coupling to cyclotron harmonic radiation in a plasma  

SciTech Connect

An electron Bernstein wave in the presence of an ion-acoustic wave of suitable wave number converts itself into cyclotron harmonic electromagnetic radiation in a plasma. The Bernstein wave imparts oscillatory velocity to electrons that couples with the density perturbation associated with the sound wave to produce a nonlinear current, driving the electromagnetic wave at sum (or difference) frequency. Conversely a large amplitude electromagnetic wave at a cyclotron harmonic can parametrically excite an electron Bernstein wave that may effectively heat the electrons.

Kumar, Asheel; Tripathi, V.K. [Department of Physics, University of Allahabad, Allahabad-211002 (India); Department of Physics, Indian Institute of Technology, New Delhi-110016 (India)

2006-05-15

245

Results from Lanzhou K450 heavy ion cyclotron  

Microsoft Academic Search

The heavy ion research facility at Lanzhou (HIRFL) consists of a K69 sector focusing cyclotron (SFC) as the injector and a K450 separated sector cyclotron (SSC) as the main accelerator. Any ions from C to Ta can be accelerated, and the maximum energies range from 5 MeV\\/u to 125 MeV\\/u. As of May 1987 the injector SFC has been put

Baowen Wei

1989-01-01

246

Comparison between californium and cyclotron heavy ion tests  

NASA Astrophysics Data System (ADS)

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

Velazco, Raoul; Provost-Grellier, Antoine

247

Superconducting magnet for K-500 cyclotron at VECC, Kolkata  

Microsoft Academic Search

K-500 superconducting cyclotron is in the advanced stage of commissioning at VECC, Kolkata. Superconducting magnet is one of the major and critical component of the cyclotron. It has been successfully fabricated, installed, cooled down to 4.2K by interfacing with LHe plant and energized to its rated current on 30th April, 2005 producing magnetic field of 4.8T at median plane of

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

2009-01-01

248

Search for Cyclotron-maser Radio Emission from Extrasolar Planets  

Microsoft Academic Search

There is reason to believe that extrasolar planets and\\/or brown dwarfs of mass about 1 to 50 M_J have magnetic fields, that they emit extremely intense cyclotron-maser radiation at metric wavelengths, and that this radiation may be detectable with sensitive radio telescopes like the VLA. The radiation is emitted at the electron cyclotron frequency, and has been detected from Earth,

G. A. Dulk; Y. Leblanc; T. S. Bastian

1997-01-01

249

High refractive index at electron cyclotron harmonics in a plasma  

Microsoft Academic Search

A theoretical explanation for the enhanced emissions of electron cyclotron harmonics from a non-relativistic plasma immersed in an external magnetic field, is considered. An asymptotic resolution of the general dispersion equation for the cyclotron harmonics and for quasi-perpendicular propagation is systematically studied. We obtain a quasi-longitudinal and a quasi-extraordinary mode, the refractive index of both modes being very large. The

Y. Furutani; G. Kalman

1965-01-01

250

Simulation of electron cyclotron current drive and electron cyclotron resonant heating for the HL-2A tokamak  

NASA Astrophysics Data System (ADS)

A quasi-linear formalism is developed for relativistic particles. It is self-consistent including spatial diffusion. An attempt is made to simulate the process of electron cyclotron resonant heating (ECRH) and electron cyclotron current drive (ECCD) for the HL-2A tokamak. Temperature oscillating regimes in Tore Supra diagnosed by MHD activity seem to be reproduced in the simulation. The special feature in this paper is to see the resonance in the long time scale for relativistic plasma.

Wang, Zhong-Tian; Long, Yong-Xing; Dong, Jia-Qi; He, Zhi-Xiong

2013-09-01

251

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

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.

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

252

Radical radiotherapy for stage I/II non-small cell lung cancer in patients not sufficiently fit for or declining surgery (medically inoperable): a systematic review  

PubMed Central

OBJECTIVES—To determine the effectiveness of radical radiotherapy in medically inoperable stage I/II non-small cell lung cancer (NSCLC) and the extent of treatment related morbidity.?METHODS—Randomised trials were sought by electronically searching the Cochrane Clinical Trials Register, and both randomised and non-randomised trials were sought by searching Medline and Excerpta Medica (Embase). Further studies were identified from references cited in those papers already identified by electronic searching. The studies included were those of patients of any age with stage I/II NSCLC receiving radiotherapy at a dose of >40 Gy in 20 fractions over 4 weeks or its radiobiological equivalent.?RESULTS—Two randomised and 35 non-randomised studies were identified. One randomised and nine non-randomised studies did not meet the selection criteria, leaving one randomised and 26 non-randomised studies for analysis. In the randomised trial 2 year survival was higher following continuous hyperfractionated accelerated radiotherapy (CHART; 37%) than following 60 Gy in 30 fractions over 6 weeks (24%). An estimated 2003 patients were included in the 26 non-randomised studies; overall survival was 22-72% at 2 years, 17-55% at 3 years, and 0-42% at 5 years. Following treatment, 11-43% of patients died from causes other than cancer. Cancer specific survival was 54-93% at 2 years, 22-56% at 3 years, and 13-39% at 5 years. Complete response rates were 33-61% and local failure rates were 6-70%. Distant metastases developed in approximately 25% of patients. Better response rates and survival were seen in those with smaller tumours and in those receiving higher doses although the reasons for prescribing higher doses were not clearly stated. The outcome was worse in those with prior weight loss or poor performance status. Assessment of treatment related morbidity and effects on quality of life and symptom control were inconclusive because of the lack of prospective evaluation and paucity of data.?CONCLUSIONS—No randomised trials compared a policy of immediate radical radiotherapy with palliative radiotherapy given when patients develop symptoms. In the absence of such trials, radical radiotherapy appears to result in a better survival than might be expected had treatment not been given. A substantial, though variable, proportion of patients died during follow up from causes other than cancer. The optimal radiation dose and treatment technique (particularly with respect to mediastinal irradiation) remain uncertain.??

Rowell, N; Williams, C

2001-01-01

253

The Oak Ridge Isochronous Cyclotron Refurbishment Project  

SciTech Connect

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.

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

2011-01-01

254

Modelling of Ion Cyclotron Wall Conditioning plasmas  

NASA Astrophysics Data System (ADS)

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.

Douai, D.; Wauters, T.; Lyssoivan, A.; Marchuk, O.; Wünderlich, D.; Brémond, S.; Lombard, G.; Mollard, P.; Pegourié, B.; van Oost, G.

2011-12-01

255

Electron cyclotron emission diagnostic for ITER  

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

256

Fullerenes in electron cyclotron resonance ion sources  

SciTech Connect

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

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

2006-03-15

257

Cyclotron-based effects on plant gravitropism  

NASA Astrophysics Data System (ADS)

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

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

258

Electron cyclotron emission diagnostic for ITER.  

PubMed

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

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

2010-10-01

259

Electron cyclotron emission diagnostic for ITER  

SciTech Connect

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

Rowan, W.; Austin, M.; Phillips, P. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Beno, J.; Ouroua, A. [Center for Electromechanics, University of Texas at Austin, Austin, Texas 78758 (United States); Ellis, R. [University of Maryland, College Park, Maryland 20742 (United States); Feder, R.; Patel, A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2010-10-15

260

Modelling of Ion Cyclotron Wall Conditioning plasmas  

SciTech Connect

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.

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

261

Feasibility study on epithermal neutron field for cyclotron-based boron neutron capture therapy.  

PubMed

To realize the accelerator-based boron neutron capture therapy (BNCT) at the Cyclotron and Radioisotope Center of Tohoku University, the feasibility of a cyclotron-based BNCT was evaluated. This study focuses on optimizing the epithermal neutron field with an energy spectrum and intensity suitable for BNCT for various combinations of neutron-producing reactions and moderator materials. Neutrons emitted at 90 degrees from a thick (stopping-length) Ta target, bombarded by 50 MeV protons of 300 microA beam current, were selected as a neutron source, based on the measurement of angular distributions and neutron energy spectra. As assembly composed of iron, AlF3/Al/6LiF, and lead was chosen as moderators, based on the simulation trials using the MCNPX code. The depth dose distributions in a cylindrical phantom, calculated with the MCNPX code, showed that, within 1 h of therapeutic time, the best moderator assembly, which is 30-cm-thick iron, 39-cm-thick AlF3/Al/6LiF, and 1-cm-thick lead, provides an epithermal neutron flux of 0.7 x 10(9) [n cm(-2) s(-1)]. This results in a tumor dose of 20.9 Gy-eq at a depth of 8 cm in the phantom, which is 6.4 Gy-eq higher than that of the Brookhaven Medical Research Reactor at the equivalent condition of maximum normal tissue tolerance. The beam power of the cyclotron is 15 kW, which is much lower than other accelerator-based BNCT proposals. PMID:12945968

Yonai, Shunsuke; Aoki, Takao; Nakamura, Takashi; Yashima, Hiroshi; Baba, Mamoru; Yokobori, Hitoshi; Tahara, Yoshihisa

2003-08-01

262

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

SciTech Connect

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.

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

263

Cyclotron-based of plant gravisensing  

NASA Astrophysics Data System (ADS)

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

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

264

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

PubMed

An investigative study of the (100)Mo (p,2n)(99m)Tc reaction on a medical cyclotron using (100)Mo2C is reported. This is the first report of this compound being used as a target for this reaction. (100)Mo2C, a refractory carbide with high thermal conductivity, properties which underscore its use on a cyclotron, was synthesized using (100)MoO3. Its ease of oxidation back to (100)MoO3 under air at elevated temperatures facilitates the use of thermo-chromatography, a high temperature gas phase separation technique for the separation and isolation of (99m)Tc. Activity yields for (99m)Tc averaged 84% of the calculated theoretical yields. Additionally, the percent recovery of MoO3, the precursor for Mo2C, was consistently high at 85% ensuring a good life cycle for this target material. The produced (99m)Tc was radio-chemically pure and easily labeled MDP for imaging purposes. PMID:23890695

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

2013-07-23

265

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

PubMed

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

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

266

Radiation Effects Testing at the 88-Inch Cyclotron at LBNL  

NASA Astrophysics Data System (ADS)

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

McMahan, M. A.; Koga, R.

2002-01-01

267

Flattop acceleration system in the RIKEN AVF cyclotron  

NASA Astrophysics Data System (ADS)

A flattop acceleration system has been developed and installed in the RIKEN Azimuthally Varying Field (AVF) cyclotron in order to improve the transmission efficiency and energy spread of beams. The flattop accelerating voltage is generated by a superposition of voltages of the fundamental and third harmonics on the dee, by attaching an additional resonator capacitively coupled to the main resonator. The flattop voltage could be generated from 36 to 63MHz corresponding to the third harmonic of the operating frequency range of 12-21MHz. A beam acceleration test was carried out and beam emittance in the longitudinal phase space was measured using a spectrometer. With this flattop system, the single-turn extraction was achieved more easily and the momentum spread was reduced to one-third. The beam transmission efficiency through the AVF cyclotron as well as the RIKEN Ring Cyclotron (RRC) has also been improved.

Kohara, S.; Goto, A.; Sakamoto, N.; Kamigaito, O.; Watanabe, S.; Teranishi, T.; Katayama, T.; Chiba, Y.; Kase, M.; Yano, Y.

2004-07-01

268

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

NASA Astrophysics Data System (ADS)

A 128 channel two-dimensional electron cyclotron emission imaging system collects time-resolved 16×8 images of Te 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.

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

269

Radiation effects testing at the 88-inch cyclotron at LBNL  

SciTech Connect

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

McMahan, Margaret A.; Koga, Rokotura

2001-10-09

270

The beam dynamics study for the CYCIAE-100 cyclotron  

NASA Astrophysics Data System (ADS)

A new RIB project, Beijing Radioactive Ion-beam Facility (BRIF), has been started at CIAE since 2004. For this project, a 100 MeV high intensity compact cyclotron, CYCIAE-100, is selected as the driving accelerator for radioactive ion beam production. The cyclotron will provide the proton beam of 75-100 MeV with an intensity of 200-500 ?A. The features of the cyclotron have already been described in several papers published elsewhere. In this paper the beam dynamics study is reviewed systematically. The basic parameters and numerical calculations results on the static orbit and accelerated orbit are given. The space charge effects, including the mutual interaction of neighboring multiple bunches in the radial direction, are studied with OPAL-CYCL code, and the current limit determined by space charge effects for this machine is predicted by fully 3D simulation.

Zhang, Tianjue; Yao, Hongjuan; Yang, Jianjun; Zhong, Junqing; An, Shizhong

2012-06-01

271

Alfven-ion-cyclotron turbulence induced by the electromagnetic ion-cyclotron instability  

NASA Astrophysics Data System (ADS)

Turbulence driven by the parametric instability of the Alfven-ion-cyclotron (AIC) waves is investigated by using a particle-in-cell simulation method. The AIC waves with a broad range are excited by the anisotropic ion temperature. In addition, harmonic modes and upper sideband modes of AIC waves are found. In the longitudinal electrostatic fluctuations, the ion-acoustic (IA) waves and its second harmonic (IA2nd) modes are found. The mode coupling between the excited fluctuations is investigated by using the bicoherence analysis. It is also shown that the electrostatic field shows a single spectrum which corresponds to IA2nd waves, whereas density fluctuation shows a dual spectrum of IA and IA2nd waves. The charge neutrality condition normally applied for the IA mode breaks down for the IA2nd mode.

Kaang, H.; Ryu, C.; Rha, K.; Rhee, T.

2011-12-01

272

Cyclotron or Synchrotron? Additional IRS Spectroscopy of Three Intermediate Polars  

NASA Astrophysics Data System (ADS)

Intermediate Polars are binary systems where a magnetic white dwarf accretes matter from a late-type, Roche lobe-filling secondary star. The standard model for IPs assumes that the magnetic field strength of the white dwarf is < 10 MG. If true, any cyclotron emission should occur in the mid-infrared region of the electromagnetic spectrum. In Cycle 2, we conducted a survey of IPs using the IRS on Spitzer and found no compelling evidence for the presence of cyclotron emission. We found that if cyclotron emission was occuring in the 5 to 14 micron bandpass, it constituted less that 0.5% of the bolometric luminosity of these systems (in the highly magnetic 'Polars', the cyclotron emission can rival the bolometric luminosity of the system!). We did, however, detect longer wavelength (> 14 micron) mid-infrared excesses for EX Hya and V1223 Sgr. These excesses are consistent with cyclotron emission from a 1 MG field. Unfortunately, the S/N of the LL2 data were poor, and we lacked the longer wavelength (LL1) observations that would clinch the case for such emission. As part of our IP survey, we extracted archival observations of AE Aqr and confirmed that its mid-infrared spectrum is dominated by optically thin synchrotron emission. It is reasonable to suggest that the LL2 detections of EX Hya and V1223 Sgr can be explained by such emission. With better LL2 data, and new LL1 observations, we will be able to determine whether the standard low field model for IPs is correct, or whether IPs are synchrotron sources. New, higher S/N data is requested for V603 Aql to determine whether it has an optically thin cyclotron emission feature at 8 microns, and whether it has a similar long wavelength excess. Our program requests 8.2 hours of Spitzer time.

Harrison, Thomas; Campbell, Ryan; Cordova, France; Howell, Steve

2007-05-01

273

Electron cyclotron resonance charge breeder ion source simulation by MCBC and GEM  

SciTech Connect

Numerical simulation results by the GEM and MCBC codes are presented, along with a comparison with experiments for beam capture dynamics and parameter studies of charge state distribution (CSD) of electron cyclotron resonance charge breeder ion sources. First, steady state plasma profiles are presented by GEM with respect to key experimental parameters such as rf power and gas pressure. As rf power increases, electron density increases by a small amount and electron energy by a large amount. The central electrostatic potential dip also increased. Next, MCBC is used to trace injected beam ions to obtain beam capture profiles. Using the captured ion profiles, GEM obtains a CSD of beam ions. As backscattering can be significant, capturing the ions near the center of the device enhances the CSD. The effect of rf power on the beam CSD is mainly due to different steady states plasmas. Example cases are presented assuming that the beam ions are small enough not to affect the plasma.

Kim, J. S.; Zhao, L.; Cluggish, B. P.; Bogatu, I. N.; Pardo, R. [FAR-TECH, Inc., 3550 General Atomics Court 15-155, San Diego, California 92121 (United States); Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2008-02-15

274

Superconducting conversion of the Oak Ridge Isochronous Cyclotron  

SciTech Connect

The superconducting conversion of the Oak Ridge Isochronous Cyclotron (ORIC) will replace the existing aluminum main magnet coils with a NbTi superconducting coil system to provide an increase in magnetic field from 1.9 to 3.3 T. The higher magnetic field will provide a three-fold increase in maximum energy capability of the cyclotron for high mass ions. The conversion will include a new beam extraction system, magnet yoke stiffening to counteract the increased magnetic forces, and minor modifications to the beam transport systems and shielding.

Martin, J.A.; Ball, J.B.; Cleary, E.D.

1981-01-01

275

Analysis of gamma ray burst spectra with cyclotron lines  

SciTech Connect

Motivated by the recent developments in the cyclotron resonance upscattering of soft photons or CUSP model of Gamma Ray Burst (GRB) continuum spectra, we revisit a select database of GRBs with credible cyclotron absorption features. We measure the break energy of the continuum, the slope below the break and deduce the soft photon energy or the electron beam Lorentz factor cutoff. We study the correlation (or lack of) between various parameters in the context of the CUSP model. One surprise result is that there appears to be marginal correlation between the break energy and the spectral index below the break. 20 refs., 8 figs., 2 tabs.

Kargatis, V. (Rice Univ., Houston, TX (USA). Dept. of Space Physics and Astronomy); Liang, E.P. (Lawrence Livermore National Lab., CA (USA))

1990-09-26

276

Temperature-resonant cyclotron spectra in confined geometries  

NASA Astrophysics Data System (ADS)

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.

Pototsky, A.; Hänggi, P.; Marchesoni, F.; Savel'Ev, S.

2011-07-01

277

ELECTRON CYCLOTRON CURRENT DRIVE EFFICIENCY IN GENERAL TOKAMAK GEOMETRY  

SciTech Connect

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.

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

2003-03-01

278

Theory of propagation of ordinary surface cyclotron waves  

SciTech Connect

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.

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

2009-01-15

279

Vacuum system of heavy ion cyclotron complex DC-60  

NASA Astrophysics Data System (ADS)

The vacuum system of the heavy ion cyclotron complex DC-60 created at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research for the interdisciplinary research complex (Astana, Kazakhstan) is described. The results of numerical simulation of transmission efficiency of accelerated ions in the course of recharging on residual gas, which determines the basic parameters of the designed vacuum system, are presented. As a result of successful implementation of the cyclotron complex DC-60 project, heavy ion beams were accelerated. The obtained parameters of the vacuum system agree completely with calculations, which were the basis of the project.

Gikal, B. N.; Tikhomirov, A. V.; Khabarov, M. V.; Chernyshev, O. A.

2008-07-01

280

Vacuum measurements of the K500 cyclotron accelerator chamber  

SciTech Connect

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.

Mallory, M.L.; Miller, P.S.; Kuchar, J.; Hudson, E.D.

1986-01-01

281

Fluid equations in the presence of electron cyclotron current drive  

SciTech Connect

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.

Jenkins, Thomas G.; Kruger, Scott E. [Tech-X Corporation, 5621 Arapahoe Avenue, Boulder, Colorado 80303 (United States)

2012-12-15

282

2D electron cyclotron emission imaging at ASDEX Upgrade (invited)  

SciTech Connect

The newly installed electron cyclotron emission imaging diagnostic on ASDEX Upgrade provides measurements of the 2D electron temperature dynamics with high spatial and temporal resolution. An overview of the technical and experimental properties of the system is presented. These properties are illustrated by the measurements of the edge localized mode and the reversed shear Alfven eigenmode, showing both the advantage of having a two-dimensional (2D) measurement, as well as some of the limitations of electron cyclotron emission measurements. Furthermore, the application of singular value decomposition as a powerful tool for analyzing and filtering 2D data is presented.

Classen, I. G. J. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Boom, J. E.; Vries, P. C. de [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Suttrop, W.; Schmid, E.; Garcia-Munoz, M.; Schneider, P. A. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); Tobias, B.; Domier, C. W.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Donne, A. J. H. [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Jaspers, R. J. E. [Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Park, H. K. [POSTECH, Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Munsat, T. [University of Colorado, Boulder, Colorado 80309 (United States)

2010-10-15

283

Design Aspects and Operation Experience With a Novel Superconducting Cyclotron for Cancer Treatment  

Microsoft Academic Search

Two superconducting cyclotrons have been delivered by ACCEL to produce 250 MeV protons for cancer treatment. Based on a conceptual design of the national superconducting cyclotron laboratory (NSCL) these machines are the first ones of their kind being engineered and built by industry. Application of superconductivity provides better and more reliable beam performance as compared to normal conducting cyclotrons. We

D. Krischel; C. Baumgarten; A. Geisler; A. Hobl; H.-U. Klein; M. Poier; H. Rocken; M. Schillo; P. vom Stein; T. Stephani; J. H. Timmer; C. Zimmer

2007-01-01

284

Development of Electron Cyclotron Resonance Ion Source for Synthesis of Endohedral Metallofullerenes  

SciTech Connect

A new electron cyclotron resonance ion source (ECRIS) has been constructed for synthesis of endohedral metallofullerenes. The main purpose of the ion source is to produce new biological and medical materials. The design is based on ECRIS for production of multicharged ion beams with a traditional minimum-B magnetic field. An 8-10 GHz traveling wave tube (TWT) amplifier and a 2.45 GHz magnetron have been applied as microwave sources. Fullerene and metal vapor are introduced with a filament heating micro-oven and an induction heating oven, respectively. In preliminary ion-extraction test, Ar{sup +} is 54 {mu}A. Many broken fullerenes such as C{sub 58} and C{sub 56} are observed in fullerene ion beams.

Tanaka, K. [Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama, Toyama, 930-1305 (Japan); Bio-Nano Electronics Research centre, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-0815 (Japan); Muramatsu, M. [Bio-Nano Electronics Research centre, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-0815 (Japan); National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Uchida, T.; Hanajiri, T.; Yoshida, Y. [Bio-Nano Electronics Research centre, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-0815 (Japan); Biri, S. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Benter 18/c (Hungary); Asaji, T.; Shima, K. [Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama, Toyama, 930-1305 (Japan); Kitagawa, A. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Kato, Y. [Division of Electrical Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

2008-11-03

285

Electron Cyclotron Resonance Ion Sources for Highly-Charged Ion Beams  

SciTech Connect

Electron Cyclotron Resonance (ECR) ion sources are used for several different applications. Primarily they are used for the production of highly-charged ion beams for nuclear physics experiments but they are also used, for example, in medical applications and radiation-hardness tests of space electronics. Strong requests have been made from the nuclear physics community towards obtaining higher beam intensities and new exotic, even radioactive, ion beams. Due to the requirements more powerful ECR ion sources and new methods for the beam production are needed. In order to meet the beam intensity requirements several superconducting ion sources have recently been built or are under construction in Asia, Europe and the USA. The development work towards improvements in ion beam quality and the production of metal ion beams is also playing a crucial role. In this article a general overview concerning the ECR ion sources, their future and beam production will be given.

Koivisto, H. [Department of Physics, University of Jyvaeskylae, FIN-40014 University of Jyvaeskylae (Finland)

2009-03-10

286

Design of a focusing high-energy heavy ion microbeam system at the JAERI AVF cyclotron  

NASA Astrophysics Data System (ADS)

For bio-medical applications of single-ion hit techniques such as radio-microsurgery, a focused high-energy heavy ion microbeam was designed and installed as a vertical beam line connected to the AVF cyclotron (/K=110) facility at JAERI Takasaki. By extracting a heavy ion microbeam into atmosphere, living cells can be irradiated with an accuracy smaller than typical cellular sizes. In addition, a high-speed automatic targeting and single-ion irradiation system was combined with a two-dimensional microbeam scanning system allowing more than 1000 targets per minute to be hit within a set field of view. Such high speeds targeting is necessary when examining statistically significant trends in cell irradiation studies within feasible time constraints. A real-time single-ion hit position detecting system was also designed to further increase the reliability of such irradiations.

Oikawa, M.; Kamiya, T.; Fukuda, M.; Okumura, S.; Inoue, H.; Masuno, S.; Umemiya, S.; Oshiyama, Y.; Taira, Y.

2003-09-01

287

Laboratory and cyclotron requirements for PET research  

SciTech Connect

This report describes four types of PET facilities: Clinical PET with no radionuclide production; clinical PET with a small accelerator; clinical PET with research support; and research PET facilities. General facility considerations are also discussed.

Schlyer, D.J.

1993-06-01

288

ADHD Medications  

MedlinePLUS

Managing ADHD With Medication Just about everyone has trouble concentrating or paying attention in class from time to time. ... to develop new medications for ADHD. Continue Are ADHD Medications Safe? Most experts agree that ADHD medications ...

289

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

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

290

Warm plasma effects on electromagnetic ion cyclotron wave MeV electron interactions in the magnetosphere  

NASA Astrophysics Data System (ADS)

The full kinetic linear dispersion relation in a warm plasma with He+ and O+ ions is used to estimate the minimum resonant electron energies required for resonant scattering of relativistic electrons by electromagnetic ion cyclotron waves. We find two significant differences from the cold-plasma approximation: (1) waves can be excited inside the stop bands and at ion gyrofrequencies for relatively small wave numbers k < ?p/vA and (2) short wavelengths with k > ?p/vA experience strong cyclotron damping. We show that, in general, minimum resonant energy of electrons Emin depends only on the wave number k, magnetic field strength B, and plasma mass density ? and depends on the wave frequency ? only implicitly, via the dispersion relation. Formulae for Emin as function of ? based on cold-plasma approximation predict the lowest energy loss where ? ? ?He+, since in this approximation k ? ? at these frequencies. We show this inference is incorrect and that kinetic effects mean that the ion gyrofrequencies are no longer necessarily preferential for low energy loss. The lowest values of Emin are obtained where the dispersion supports the largest wave numbers k and in the regions of the largest mass densities ? and the lowest magnetic fields B. For realistic magnetospheric conditions Emin ˜ 2 MeV and can only drop to ˜500 keV inside dense plasmaspheric plumes, with plasma density of the order of 500 cm-3, or during plasmaspheric expansions to high L shells (L ˜ 7).

Silin, I.; Mann, I. R.; Sydora, R. D.; Summers, D.; Mace, R. L.

2011-05-01

291

Electron-cyclotron-resonant-heated electron distribution functions  

SciTech Connect

Recent studies at Lawrence Livermore National Laboratory (LLNL) with a bounce-averaged Fokker-Planck code indicate that the energetic electron tail formed by electron-cyclotron resonant heating (ECRH) at the second harmonic is not Maxwellian. We present the results of our bounce-averaged Fokker-Planck code along with some simple analytic models of hot-electron distribution functions.

Matsuda, Y.; Nevins, W.M.; Cohen, R.H.

1981-06-26

292

BEAM LINES FOR PHYSICAL EXPERIMENTS OF DC350 CYCLOTRON  

Microsoft Academic Search

The beam lines for physical experiments of DC-350 cyclotron are presented. The bending magnet with variable magnetic field up to 1.5 T gives possibility to transport ion beam to five experimental installations. The beam focusing in the beam lines is provided by set of quadrupole lenses. The beam diagnostics consists of the Faraday caps, luminophors, aperture diaphragms, wire scanners and

G. Gulbekyan; G. Ivanov; I. Kalagin; V. Kazacha; N. Kazarinov; M. Khabarov; V. Melnikov

293

Maryland University Sectored Isochronous Cyclotron (MUSIC): Progress Report No. 14.  

National Technical Information Service (NTIS)

The past quarter has seen further progress in the solution of the problem of achieving a cyclotron which meets or exceeds the performance requirements. The magnet system, with the exception of the trim coils and their supplies, is all on order or about to...

1967-01-01

294

Computerized Simulation of a Magnetic Structure of the Superconducting Cyclotron.  

National Technical Information Service (NTIS)

Geometric parameters of a magnetic structure of the isochronous cyclotron for accelerating ions with A/Z=2 upto 30 MeV/nucl energy are determined. The shape of electromagnet three spiral shims for the pole piece diameter of 185 cm has been calculated. The...

Y. G. Alenitskij S. I. Chesnova V. V. Leonov E. M. Khodakov V. K. Shlejfman

1988-01-01

295

Comparison between californium and cyclotron heavy ion tests  

Microsoft Academic Search

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

Raoul Velazco; Antoine Provost-Grellier

1990-01-01

296

Development of high frequency, cyclotron harmonic gyrotron oscillator  

Microsoft Academic Search

The oscillation results of a high frequency gyrotron which operates at the fundamental cyctron frequency and its higher harmonics (s=1, 2, 3) are described. The fairly high frequency of 220 GHz (corresponding wave length 1.35 mm) has been achieved at the fundamental and second harmonic of the cyclotron frequency. The scaling law of output power to harmonic number s is

Toshitaka Idehara; Toshiaki Tatsukawa; Satoru Matsumoto; Kohji Kunieda; Kazuhisa Hemmi; Tomohiro Kanemaki

1988-01-01

297

Alfven-cyclotron Scattering of Solar Wind Ions: Hybrid Simulations  

NASA Astrophysics Data System (ADS)

Cyclotron resonances are the fundamental wave-particle interaction between ions and Alfvén-cyclotron fluctuations at sufficiently short wavelengths and at propagation approximately parallel or antiparallel to a background magnetic field B_o in a relatively uniform, collisionless plasma. Cyclotron resonance enables pitch-angle scattering, typically leading to changes in the perpendicular (to B_o) energies of that species. If alpha particles are a minority ion, the proton and alpha resonance conditions are sensitive functions of the alpha/proton relative speed v? p} parallel or antiparallel to Bo. The research described here utilizes ensembles of hybrid simulations in which damped Alfvén-cyclotron fluctuations are imposed upon a steady, homogeneous plasma characterized by average solar wind parameters near 1 AU and bearing both protons and alpha particles. The simulations yield ion species responses to such fluctuations as functions of three parameters: the initial v? p/vA (where vA is the Alfvén speed), the initial magnitude of the applied fluctuating magnetic field energy density, and the relative density of the alphas. For average solar wind conditions near Earth, if magnetic power spectra extend to sufficiently short wavelengths, saturation of alpha scattering is most likely due to exhaustion of the fluctuating field energy density.

Gary, S. P.; Yin, L.; Winske, D.

2005-12-01

298

Proposals for ITER Ion Cyclotron Reference Design Upgrades  

Microsoft Academic Search

A possible issue for the ITER Ion Cyclotron Heating and Current Drive system is related to the high electric field (2 kV\\/mm parallel to B0) at which the array is planned to operate, which may be associated to a low dielectric rigidity of the of the vessel ``vacuum''. The combined effects are likely to set the upper limit to the

G. Bosia; B. Beaumont; S. Brémond; P. Testoni; K. Vulliez

2005-01-01

299

Electron-cyclotron-heating experiments in tokamaks and stellarators  

SciTech Connect

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

England, A.C.

1983-01-01

300

Unique Features of the Texas A & M Variable Energy Cyclotron  

Microsoft Academic Search

This paper describes some of the design, engineering, construction and procurement details of the Texas A & M University Variable Energy Cyclotron (TAMVEC). All major engineering has been completed, and system components are presently under construction at various vendor plants throughout the country. Assembly and installation of the machine will begin in the latter part of June 1966. It is

W. A. McFarlin; D. J. Goerz

1966-01-01

301

KEKCB electron cyclotron resonance charge breeder at TRIAC  

Microsoft Academic Search

The KEKCB is an electron cyclotron resonance (ECR) ion source for converting singly charged ions to multicharged ones at Tokai Radioactive Ion Accelerator Complex. By using the KEKCB, singly charged gaseous and nongaseous ions were converted to multicharged ones of A\\/q~=7 with efficiencies of 7% and 2%, respectively. The conversion efficiency was found to be independent of the lifetime of

N. Imai; S. C. Jeong; M. Oyaizu; S. Arai; Y. Fuchi; Y. Hirayama; H. Ishiyama; H. Miyatake; M. H. Tanaka; M. Okada; Y. X. Watanabe; S. Ichikawa; H. Kabumoto; A. Osa; Y. Otokawa; T. K. Sato

2008-01-01

302

Cyclotron Resonance of Electrons Trapped in a Microwave Cavity  

ERIC Educational Resources Information Center

|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)|

Elmore, W. C.

1975-01-01

303

Status of the cyclotron vacuum system at TRIUMF  

Microsoft Academic Search

The world's largest cyclotron was built at TRIUMF in 1972 and commissioned to full energy in 1974 [Harwood VJ, Yandon JC. TRIUMF Design Note, TRI-69-7, 1969 [1], Blakely RG, Moore RW, Harwood VJ. TRIUMF Design Note, TRI-69-9, 1969 [2

I. Sekachev

2006-01-01

304

Galileo observations of ion cyclotron waves in the Io torus  

Microsoft Academic Search

Ion cyclotron waves generated near Io have been observed on four Galileo passes of the plasma torus, in December 1995, October 1999, November 1999, and February 2000. The waves have frequencies near the gyrofrequencies of SO+2 and SO+ ions, and are propagating at angles up to 40° to the ambient magnetic field. These waves are generated by ring-beam distributions of

X. Blanco-Cano; C.T. Russell; R. J. Strangeway; M. G. Kivelson; K. K. Khurana

2001-01-01

305

A phase-imaging technique for cyclotron-frequency measurements  

NASA Astrophysics Data System (ADS)

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.

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.

2013-09-01

306

Cyclotron-wave converter for SPS energy transmission system  

NASA Astrophysics Data System (ADS)

The possibility of cyclotron-wave converter (CWC) realization with power level up to 100 kW, output voltage up to 100 kV, efficiency to 85-90 percent and high reliability is presented. The perspectives of CWC application in the SPS ground station are discussed in comparison with rectenna elements based on Schottky-barrier diodes.

Vanke, V. A.; Savvin, V. L.

307

A micropulse monitor for control of cyclotron beams  

NASA Astrophysics Data System (ADS)

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

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

1990-07-01

308

Status of ECR (Electron Cyclotron Resonance) source technology  

SciTech Connect

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.

Lyneis, C.M.

1987-03-01

309

Three-dimensional trim coil field in the VINCY cyclotron.  

National Technical Information Service (NTIS)

The trim coil magnetic field in the VINCY cyclotron was performed with the help of the three-dimensional (3D) software. The comparison of the 2D and 3D trim coil calculation results are presented. The 3d calculations of trim coil show some difference in t...

S. B. Vorozhtsov I. V. Titkova O. V. Lomakina D. V. Altiparmakov M. Lazovic

1996-01-01

310

Cyclotron emissivity of a plasma of arbitrary density  

Microsoft Academic Search

The spectral emissivity of a nonrelativistic plasma of arbitrary density for frequencies above the electron cyclotron frequency is derived. A general formula is applied to the case of thermal equilibrium, and an analytic formula for emission perpendicular to the static magnetic field is explained. For arbitrary directions, results can be calculated numerically and given in graphic form. Results provided by

K. Audenaerde

1977-01-01

311

a New Miniature Electron Cyclotron Resonance Ion Source  

Microsoft Academic Search

A compact electron cyclotron resonance (ECR) ion source has been designed and built which has a magnetic mirror and sextupole system consisting entirely of permanent magnets to contain and stabilize a plasma. Microwaves at 2.45 GHz were coupled to the plasma in the RHCP mode to induce resonant heating in the plasma. The essential elements of the ECR plasma system

Caesar Romero Jackson

1992-01-01

312

Invited Paper-Polarized Ion Sources for Cyclotrons  

Microsoft Academic Search

Since their advent six years ago polarized ion sources have been successfully installed in 15 accelerators of various types around the world, including FF, FM, and isochronous cyclotrons. The advantages of sources over nuclear reactions for providing polarized particles are (1) greater intensity, (2) control of polarization mode and direction, and (3) freedom from background radiation from the primary target.

M. K. Craddock

1966-01-01

313

Design of a beam buncher for the KIRAMS-30 cyclotron  

Microsoft Academic Search

A general method to increase the efficiency of a particle accelerator with an external ion source system is to use a buncher. It generates a pulsed beam from the dc beam and the period of a pulsed beam is matched to RF frequency of cyclotron. A concept drawing of a beam buncher is designed according to the distance of buncher

In Su Jung; Dong Hyun An; Bong Hwan Hong; Min Goo Hur; Joon Sun Kang; Hong Suk Chang; Tea Gun Yang; Min Young Lee; Seong Seok Hong; Yu Seuk Kim; Jong Seo Chai; Key Ho Kwon

2007-01-01

314

Cyclotron Autoresonance with TE and TM Guided Waves  

Microsoft Academic Search

The electron cyclotron autoresonance is of both theoretical and practical interest for acceleration of charged particles and for generation of microwave radiation in various gyro-devices. In this paper a unified first-principles approach is applied to the analysis of the interaction of gyrating electrons with electromagnetic waves with different characteristic impedance. In contrast to the previous works that consider the underlying

S. Sabchevski; T. Idehara

2005-01-01

315

A CCD camera probe for a superconducting cyclotron  

Microsoft Academic Search

The authors developed a probe for a K1200 superconducting cyclotron based on a charge coupled device (CCD) TV camera that works in a 6 T magnetic field. The camera looks at the beam spot on a scintillating screen. The TV image is processed by a frame grabber that digitizes and displays the image in pseudocolor in real time. This probe

F. Marti; R. Blue; J. Kuchar; J. A. Nolen; B. Sherrill; J. Yurkon

1991-01-01

316

On 'conflict of conservation laws in cyclotron radiation  

Microsoft Academic Search

We reconsider the apparent conflict of conservation laws in cyclotron radiation discovered by Lieu et al (1983). We show that they did not correctly include the effects of radiation reaction in their calculation. When a 'recoil' term, calculated using relativistic quantum theory, is included in the angular momentum of the particle the conflict disappears. We find that the guiding centre

S M White; A J Parle

1985-01-01

317

Axial injection and phase selection studies of the MSU K1200 cyclotron  

SciTech Connect

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

Bailey, J.D. [Oak Ridge National Lab., TN (United States)]|[Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)

1995-12-31

318

Space charge instabilities in gyrotron beams and theory of gyro-traveling-wave-amplifiers at cyclotron harmonics  

SciTech Connect

This dissertation concerns itself with two important issues in the study of gyrotrons. In Part I, the authors study the space charge instabilities in gyrotron electron beams via both solution of the linear dispersion equation and the nonlinear particle simulation. The linear analysis addressed the stabilizing effects of energy spread in the beams and the gradient of the external magnetic field. The nonlinear multi-frequency simulation demonstrates that the energy spread induced by multiple unstable waves in the nonlinear saturation stage is more significant than the corresponding spread induced by a single unstable wave. This indicates that the deleterious effect on the quality of the beam will be greater than previously expected, and emphasizes the need to design electron guns which are stable to this wave mode. In Part II, the authors develop a generalized theory of gyro-traveling-wave tubes (gyro-TWTs) operating at arbitrary cyclotron harmonics. In the framework of small signal theory, the authors obtain and analyze the dispersion equation and discuss a problem of spurious counterpropagating waves excitation. In the large-signal study, the authors predict the possibility of achieving high efficiency of operation at the first four cyclotron harmonics and show that the orbital efficiency of the relativistic gyro-TWT operating at the second cyclotron harmonic with large frequency up-conversion may exceed 60%. The results obtained also demonstrate that the sensitivity of the harmonic gyro-TWT efficiency with respect to the electron velocity spread strongly depends on axial wavenumbers of the travelling waves.

Li, H.

1993-01-01

319

A Small High Performance Microprocessor Core Sirius for Embedded Low Power Designs, Demonstrated in a Medical Mass Application of an Electronic Pill(EPill®)  

Microsoft Academic Search

A new, small, and for low power optimized, processor core SIRIUS has been developed, simulated, synthesized to a netlist and verified. From this netlist, containing only primitives like gates and flip-flop s, a mapping to an ASIC technology or a FPGA technology can easily be done with existing synthesizer tools, allowing very complex SOC designs with several blocks. Emulation via

Dirk Jansen; Nidal Fawaz; Daniel Bau; Marc Durrenberger

2007-01-01

320

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

Microsoft Academic Search

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

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

2001-01-01

321

Beam orbit simulation in the central region of the RIKEN AVF cyclotron  

NASA Astrophysics Data System (ADS)

This paper describes the modification design of the central region for h=2 mode of acceleration in the RIKEN AVF cyclotron. we made a small modification to the electrode shape in the central region for optimization of the beam transmission. The central region is equipped with an axial injection system. The spiral type inflector is used for axial injection. The electric field distribution in the inflector and in four acceleration gaps has been numerically calculated from an electric potential map produced by the program RELAX3D. The magnetic field is measured. The geometry of the central region has been tested with the computations of orbits carried out by means of the computer code CYCLONE. The optical properties of the spiral inflector and the central region are studied by using the program CASINO and CYCLONE, respectively. We have also made an effort to minimize the inflector fringe field effects using the RELAX3D program.

Toprek, D.; Goto, A.; Yano, Y.

1999-04-01

322

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

PubMed

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. PMID:23742544

Chen, Dezhi; Chen, Zihao; Liu, Kaifeng; Yang, Jun; Li, Dong; Qin, Bin; Xiong, Yongqian

2013-05-01

323

High Power Cyclotrons for Accelerator Driven System (ADS)  

NASA Astrophysics Data System (ADS)

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

Calabretta, Luciano

2012-03-01

324

Botox (Medical)  

MedlinePLUS

... Eye Glossary Current News How to Help Botox (Medical) Share with a friend Botox (Medical) A link to this article will be included ... list. Close without sharing. Give Us Feedback Botox (Medical) Your name First Name MI Laast Name Your ...

325

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 ...

326

Impact of a medical waste incinerator on mercury levels in lagoon fish from a small tropical island in the Western Pacific.  

PubMed

In 2004-2005, several species of marine fish were collected for mercury (Hg) analysis from Saipan Lagoon, Saipan, Commonwealth of the Northern Mariana Islands. Relatively high concentrations were found in representatives from the Hafa Adai Beach area located some distance from known sources of Hg contamination. A follow-up investigation aimed at identifying additional land-based sources of Hg in the area was launched in early 2007. The study identified a medical waste incinerator as the primary source of Hg enrichment. The incinerator was operational for about 20 years before it was closed down by the U.S. Environmental Protection Agency (EPA) in January 2006, for multiple violations of the Clean Air Act. Stormwater runoff from this facility entered a drainage network that discharged into the ocean at the southern end of Hafa Adai Beach, about 1 km away. At the time of this investigation storm drain sediments at the coast were only marginally enriched with mercury although values some 50x above background were detected in drainage deposits a few meters down-gradient of the incinerator site. Mercury concentrations in fish from the Hafa Adai Beach area were also significantly lower than those determined in similar species 3 yr earlier. The implications of the data are briefly discussed. PMID:21598167

Denton, Gary R W; Trianni, Michael S; Bearden, Brian G; Houk, Peter C; Starmer, John A

2011-01-01

327

Cooling Electron Plasmas by Cyclotron-Cavity Resonance  

NASA Astrophysics Data System (ADS)

A robust technique for cooling trapped non-neutral plasmas is to allow leptons to thermalize to the temperature of the experimental environment through cyclotron emission. Storing these plasmas in a high-Q cavity can enhance or inhibit this cooling mechanism dependent on the cyclotron frequency, the electromagnetic mode structure in the cavity, and the profile of the trapped plasma. Also, thermalization rates may be limited as temperatures in the system approach the energy spacing between Landau levels- the quantum mechanical levels of transverse particle motion in the system. This is a regime possible in a cryogenic environment with high magnetic fields, such as typically used in Penning-Malmberg traps. Here, we report on the progress of the cold electron research experiment at UC Berkeley designed to measure these effects.

Povilus, Alex; Baquero-Ruiz, Marcelo; Chapman, Steve; Fajans, Joel

2012-10-01

328

Improved energy resolution of a cyclotron beam for RBS measurements  

NASA Astrophysics Data System (ADS)

For RBS (Rutherford Back Scattering) analysis, the quality of the beam is of premium importance because the depth profile resolution of the method is strongly dependent on the energy resolution of the probing beam. A magnetic analyzer, consisting of two 90 left right bending magnets forming an achromatic doublet has been adapted to the Liege 20 MeV (proton) AVF (Azimuthal Varying Field) cyclotron. The energy resolution of that system has been measured by recording the resonance width of a 32S(p,p??)32S (3.38 MeV. p+ lab. energy). We have obtained a value of ?E = ± 2 keV, reducing by a factor of 20 the natural dispersion of our cyclotron. We describe our magnetic analyzer system and present the results of our RBS measurements at energies up to 14 MeV ?.

Chêne, G.; Garnir, H.-P.; Marchal, A.; Mathis, F.; Strivay, D.

2008-05-01

329

Status report on the JAERI AVF cyclotron system  

NASA Astrophysics Data System (ADS)

The AVF cyclotron system at JAERI Takasaki has been smoothly operated without serious troubles since the first beam extraction of 50 MeV 4He2+ in March 1991. A yearly operation time is about 3200 hours on an average for past several years. In the last three years, we performed some improvements and developments as follows: stabilization of the cyclotron beam, renewal of computers and basic programs for the control system, installation of a new ECR ion source and reconstruction of the rotary shutter. Furthermore, two series of M/Q=4 and M/Q=2 cocktail beams have been developed continuously. Now we are modifying the RF cavities for the flat-top acceleration by superimposing the fifth-harmonic frequency on the fundamental one. .

Nakamura, Y.; Nara, T.; Agematsu, T.; Ishibori, I.; Tamura, H.; Kurashima, S.; Yokota, W.; Okumura, S.; Fukuda, M.; Arakawa, K.

2001-12-01

330

Ion Behavior in an Electrically Compensated Ion Cyclotron Resonance Trap  

PubMed Central

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.

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

2010-01-01

331

RF Heating in Electron Cyclotron Resonance Ion Sources  

SciTech Connect

ECRIS-Electron Cyclotron Resonance Ion Sources are able to feed accelerators with intense currents of highly charged ions. In ECRIS a high density-high temperature plasma is generated by means of the Electron Cyclotron Resonance Heating inside a B-min, MHD stable trap. The state of the art about the principal heating mechanisms will be given. The paper will specially discuss the most critical and still open issues concerning the influence of the magnetic field and of the RF frequency on the plasma heating, as well as the impact of possible non-linear pumping wave-to-plasma interactions. The contribution of INFN-LNS will be specifically underlined. A short review on the future perspectives for the design of new generation ion sources will be given in conclusion.

Mascali, D. [INFN - LNS, via S. Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria, 6 - 95125 Catania (Italy); Gammino, S.; Celona, L.; Ciavola, G. [INFN - LNS, via S. Sofia 62, 95123 Catania (Italy)

2011-12-23

332

PHYSICS OF ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D  

SciTech Connect

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

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

2002-11-01

333

RF Heating in Electron Cyclotron Resonance Ion Sources  

NASA Astrophysics Data System (ADS)

ECRIS--Electron Cyclotron Resonance Ion Sources are able to feed accelerators with intense currents of highly charged ions. In ECRIS a high density--high temperature plasma is generated by means of the Electron Cyclotron Resonance Heating inside a B-min, MHD stable trap. The state of the art about the principal heating mechanisms will be given. The paper will specially discuss the most critical and still open issues concerning the influence of the magnetic field and of the RF frequency on the plasma heating, as well as the impact of possible non-linear pumping wave--to--plasma interactions. The contribution of INFN-LNS will be specifically underlined. A short review on the future perspectives for the design of new generation ion sources will be given in conclusion.

Mascali, D.; Gammino, S.; Celona, L.; Ciavola, G.

2011-12-01

334

PHYSICS OF ELCTRON CYCLOTRON CURRENT DRIVE ON DIII-D  

SciTech Connect

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

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

2002-09-01

335

Vortex cyclotron resonance in high-T{sub c} superconductors  

SciTech Connect

The orbital motion of pancake vortices takes place as a result of momentum exchange with electromagnetic waves. The coherent wave for vortex motion is obtained from the Lorentz-covariant wave equation for vortices. When the static magnetic field is tilted from the c axis, the vortex orbit becomes elliptical due to an interlayer electromagnetic interaction or gauge current. The gauge current also produces a coupling between the vortex cyclotron motion and transverse Josephson plasma, which was experimentally observed. The cyclotron mass of superfluid electrons and the frequency of a transverse Josephson plasma were obtained in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. {copyright} {ital 1998} {ital The American Physical Society}

Ichiguchi, T. [Advanced Research Lab., Hitachi Ltd., Hatoyama, Saitama, 350-03 (Japan)

1998-01-01

336

Ion Cyclotron Heating in the Model C Stellarator  

Microsoft Academic Search

A new ion cyclotron resonance heating system has been installed on the Model C stellarator. Use of low-power rf during the entire Ohmic heating pulse shows that the density for optimum coupling is a factor of 1.5-2 greater than that calculated from a simple theory. The variation of coupling with density and plasma radius is found to agree with theory.

M. A. Rothman; R. M. Sinclair; I. G. Brown; J. C. Hosea

1969-01-01

337

Comparison between Californium and cyclotron S. E. U. tests  

Microsoft Academic Search

In this paper, experimental equipment allowing to perform heavy ion testing for programmable integrated circuits is presented. This equipment was used along with two different types of heavy ion simulator to perform SEU tests on representative circuits: a dedicated Cf²⁵² fission decay source developed by CERT-DERTS and the LBL 88'' cyclotron. The observed discrepancies between the results obtained using a

R. Velazco; A. Provost-Greillier; T. Chapuis; M. Labrunee; D. Falguere; R. Koga

1989-01-01

338

Electron cyclotron heating scenario and experimental results in LHD  

Microsoft Academic Search

A large helical device (LHD) experiment began at the end of March 1998. Fundamental and second harmonic electron cyclotron heating (ECH) are used as a plasma production and heating method with six gyrotrons whose frequencies are 82.6\\/84 and 168 GHz, respectively. Up to 0.9 MW power has been injected in LHD with long distance corrugated waveguide transmission systems. The maximum

H Idei; S Kubo; T Shimozuma; M Sato; K Ohkubo; Y Yoshimura; Y Takita; S Kobayashi; S Ito; Y Mizuno; K Tsumori; K Ikeda; T Notake; T Watari; O Kaneko; A Komori; H Yamada; P. C de Vries; M Goto; K Ida; S Inagaki; S Kado; K Kawahata; T Kobuchi; T Minami; J Miyazawa; T Morisaki; S Morita; S Murakami; S Muto; Y Nagayama; H Nakanishi; K Narihara; B. J Peterson; S Sakakibara; H Sasao; K Sato; K Tanaka; Y Takeiri; K. Y Watanabe; I Yamada; O Motojima; M Fujiwara

2001-01-01

339

Alfve´n-ion-cyclotron instability in mirror machines  

Microsoft Academic Search

The Alfve´n-ion-cyclotron instability is studied for finite mirror-confined plasmas with high beta without field reversal. Variation perpendicular to field lines is modeled by an effective k?. Variation along a representative field line is treated using the Wentzel-Kramer-Brillouin approximation in two ways. First, the local dispersion relation is expanded about a wavenumber and frequency corresponding to absolute instability at the machine

Duncan C. Watson

1980-01-01

340

Cyclotron Resonance in Graphene at Ultrahigh Magnetic Fields  

Microsoft Academic Search

To investigate the effects of intentional and unintentional doping on the conduction properties of CVD-grown large-area graphene, we have performed high-field cyclotron resonance (CR) measurements on graphene. We accessed ultrahigh magnetic fields using the Single-Turn Coil System at NHMFL-Los Alamos, which can produce peak fields over 300 T in ˜2.5 mus pulses. We investigated magneto-infrared transmission at 10.6 mum in

L. G. Booshehri; C. H. Mielke; S. A. Crooker; L. Ren; E. H. Haroz; Z. Jin; Z. Sun; Z. Yan; J. M. Tour; J. Kono

2011-01-01

341

TRIUMF CYCLOTRON VACUUM SYSTEM UPGRADE AND OPERATIONAL EXPERIENCE  

Microsoft Academic Search

The replacement of the 30-year-old Philips cryogenerator with a modern LINDE-1630 helium refrigerator is an important component of TRIUMF's ongoing 500 MeV cyclotron refurbishing program. Two 10.7 m long cryopanels are cooled with liquid helium rather than with 17 K helium gas, as was the case with the cryogenerator. This has increased the pumping speed and, respectively, improved the vacuum

I. Sekachev; I. Bylinskii; A. Koveshnikov; I. Slobodov; D. Yosifov

2009-01-01

342

Highly Selective Contact Hole Etching Using Electron Cyclotron Resonance Plasma  

Microsoft Academic Search

The SiO2 etching process is one of the most significant processes in ultra-large-scale integration (ULSI) fabrication. In order to obtain fine contact holes, it is necessary to achieve both highly selective etching of SiO2 over other materials, and non-reactive ion etch (non-RIE) lag. We investigated the etching characteristics and the effect of O2 addition in C4F8+O2 plasma using electron cyclotron

Hajime Kimura; Ken'ichiro Shiozawa; Kenji Kawai; Hiroshi Miyatake; Masahiro Yoneda

1995-01-01

343

Status Report on the K.V.I. Cyclotron  

Microsoft Academic Search

The K.V.I. cyclotron, which has a maximum energy of 160 Q2\\/A MeV and which has been constructed by Philips, has been in regular operation since 1972. The machine is used mainly for nuclear physics with light ion beams. However, beams of heavier ions are in increasing demand. The Livingston type ion source now used only gives modest currents of C

O. C. Dermois; A. G. Drentje; H. W. Schreuder

1979-01-01

344

GENERIC COMPONENT CLASS IN JAVA FOR CYCLOTRON CONTROL SYSTEM  

Microsoft Academic Search

A generic Java class-structure comprising of a number of Cyclotron oriented control components with effective control features has been constructed for use in the universal MMI(1), The usable components are of four distinct categories i.e. Boolean Monitor, Boolean Control, Analog Monitor and Analog Control. They can be inter- linked in a tree structure. Operational safety interlocks can be implemented in

Tapas Samanta; S. Dasgupta

345

BEAM SIMULATION OF SQQ INJECTION SYSTEM IN KIRAMS-30 CYCLOTRON  

Microsoft Academic Search

The injection system of KIRAMS-30 cyclotron consists of a doublegap buncher,an SQQ, and a spiral inflector. Ini- tial beam with 100 mmmrad has been generated by random Gaussian function in the transverse plane and random uni- form function in the longitudinal direction. Using the 3D electric and magnetic fields of a buncher, SQQ, inflector, and return-yoke bore, the characteristics of

Dong Hyun An; Joonsun Kang; In Su Jung; Hong Suk Jang; Bong Hwan Hong

346

Pencil Beam Scanning System Based On A Cyclotron  

SciTech Connect

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.

Tachikawa, Toshiki; Nonaka, Hideki; Kumata, Yukio [Sumitomo Heavy Industries, Ltd., 5-2 Soubiraki-cho, Niihama, Ehime 792-8588 (Japan); Nishio, Teiji; Ogino, Takashi [National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577 (Japan)

2011-06-01

347

Converting an AEG Cyclotron to H- Acceleration and Extraction  

NASA Astrophysics Data System (ADS)

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.

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

2009-03-01

348

Topology of relativistic refractive index surfaces for electron cyclotron waves  

Microsoft Academic Search

The dispersion of electron cyclotron waves in a weakly relativistic Maxwellian plasma is investigated. It is shown that the apparently very complicated picture of the coupling of the extraordinary (X) mode to Bernstein waves can be accounted for in a simple way by considering the refractive indices as Riemann-like surfaces in the Clemmow-Mullaly-Allis (CMA) parameter space, ( omega p2\\/ omega

J. Egedal; H. Bindslev

1994-01-01

349

Design of a beam buncher for the KIRAMS-30 cyclotron  

NASA Astrophysics Data System (ADS)

A general method to increase the efficiency of a particle accelerator with an external ion source system is to use a buncher. It generates a pulsed beam from the dc beam and the period of a pulsed beam is matched to RF frequency of cyclotron. A concept drawing of a beam buncher is designed according to the distance of buncher electrode gap and an electric field. Beam bunching is generated, when charged particles are accelerated and decelerated periodically with an electric field at an electrode gaps. In this paper, we designed the beam buncher for the KIRAMS-30 cyclotron. The KIRAMS-30 cyclotron which will be installed at advanced radiation technology institute (ARTI) until next February, is equipped with an external multicusp ion source. The buncher is installed into a beam injection line just before solenoid quadrupole quadrupole (SQQ) and injection system design was already fixed. The purpose of the beam buncher was to achieve high efficiency, easy-to-tune and low cost.

Jung, In Su; An, Dong Hyun; Hong, Bong Hwan; Hur, Min Goo; Kang, Joon Sun; Chang, Hong Suk; Yang, Tea Gun; Lee, Min Young; Hong, Seong Seok; Kim, Yu Seuk; Chai, Jong Seo; Kwon, Key Ho

2007-08-01

350

A Suzaku View of Cyclotron Line Sources and Candidates  

NASA Astrophysics Data System (ADS)

Sixteen 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 slightly more than half of them, plus a few similar systems without known CRSFs, have been observed with Suzaku. I present an overview of results from these observations, including the discovery of a CRSF in the transient 1A 1118-61 and pulse phase and/or time resolved analyses. They 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. I briefly introduce a spectral model for CRSFs that is currently being developed and that for the first time is based on these physical properties. In addition to cyclotron line measurements, selected highlights from the Suzaku sample include, e.g., iron line studies and disentangling absorption and mass transfer variations in the clumpy winds of 4U 1907+09 and Vela X-1.

Pottschmidt, Katja

2011-09-01

351

A Suzaku view of cyclotron line sources and candidates  

NASA Astrophysics Data System (ADS)

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 for the first time is based on these physical properties. In addition to cyclotron line measurements, selected highlights from the Suzaku analyses include dip and flare studies, e.g., of 4U 1907+09 and Vela X-1, which show clumpy wind effects (like partial absorption and/or a decrease in the mass accretion rate supplied by the wind) and may also display magnetospheric gating effects.

Pottschmidt, K.; Suchy, S.; 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.

2012-03-01

352

Cryogenic system upgrade for the National Superconducting Cyclotron Laboratory  

SciTech Connect

The National Superconducting Cyclotron Laboratory (NSCL) is a National Science Foundation supported facility, with additional support from Michigan State University (MSU). The facility consists of two superconducting cyclotrons and over fifty individual cryostats, each containing several superconducting magnets that are used in the beam transport system. The facility also has a superconducting ion source and a large superconducting spectrograph. To support this facility we operated two helium refrigerators producing approximate 900W at 4.5K. In July of 1999, construction of a new beam analysis system, the A1900, was started. The laboratory was reconfigured to couple the two cyclotrons in series to enable the facility to produce higher intensity radioactive beams than previously possible in the stand-alone mode. In addition, the helium distribution system was upgraded with new transfer lines and a new distribution box. The new requirements increased the refrigeration load to more than 1 KW at 4.5K. To support this increased cryogenic load, the existing two helium cryogenic plants, were at best, marginal in capacity. This would have required both plants to run at full capacity, maximum efficiency and availability. To achieve higher reliability, availability, and process transient capacity for magnet cool down and filling, a decision was made to obtain a larger cryogenic plant to support the new system. The following paper describes the important aspects and capabilities of the new cryogenic system to accomplish this goal.

A. McCartney; V. Ganni; H. Laumer; D. Arenius; J. Creel; W. Chronis; K. Davidson

2002-05-10

353

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

SciTech Connect

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.

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

354

Medical scribes.  

PubMed

Medical scribes and electronic health records (EHRs) are increasingly being introduced into ambulatory clinics with variable outcomes. Characteristics of a successful implementation of medical scribes are described. Tips for optimization of the composition and presentation of the EHR as well as medical processes associated with medical documentation are presented. PMID:23373160

Baugh, Reginald; Jones, James E; Trott, K; Takyi, Valerie E; Abbas, Jihad T

355

Conceptual design of a high field ultra-compact cyclotron for nuclear physics research  

Microsoft Academic Search

We have studied the feasibility of using an existing wide-bore 8 T magnet as a component of an ultra-high-field cyclotron. Such a machine would use the highest magnetic field of any cyclotron to date, viz. 7.6 T averaged azimuthally with 8.5 T in the hills. The K95 `Eight Tesla Cyclotron' would have roughly the same magnetic rigidity (B?) as the

J. Schubert; H. Blosser

1997-01-01

356

Ray trajectories near the electron cyclotron resonance surface in an axisymmetric magnetic trap  

SciTech Connect

Characteristic features of the propagation of electromagnetic electron cyclotron waves in the vicinity of the electron cyclotron resonance surface are investigated both analytically and numerically with allowance for variation in the magnetic field strength and a corresponding variation in the magnetic field direction. It is demonstrated that variation in the magnetic field direction can qualitatively change the wave propagation pattern and can markedly affect the efficiency of electron cyclotron resonance plasma heating in an axisymmetric magnetic trap.

Gospodchikov, E. D.; Smolyakova, O. B. [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)

2011-09-15

357

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

358

The efficient production of high specific activity copper-64 using a biomedial cyclotron  

SciTech Connect

We have developed a method for the efficient and cost-effective production of high specific activity Cu-64, via the Ni-64(p,n)Cu-64 reaction, using a small biomedical cyclotron. Nickel-64 (95% enriched) has been successfully electroplated on gold disks at thicknesses of {approximately}20-300 {mu}ms and bombarded with protons at beam currents up to {approximately}45 microamps. An automated target has been designed to facilitate the irradiations on a biomedical cyclotron. Techniques have been developed for the rapid and efficient separation of Cu-64 from Ni-64 and other reaction byproducts using ion exchange chromatography. An initial production run using 55 mg of 95% enriched Ni-64 yielded 20 GBq of Cu-64 with specific activity of 4.5 GBq/{mu}g (determined by serial dilution titrations with TETA). In a series of experiments, bombardment of 18.7-23.7 mg of 85% enriched Ni-64 has produced 8.9-18.5 GBq of Cu-64 with specific activity of 4.5 GBq/{mu}g (determined by serial dilution titrations with TETA). In a series of experiments, bombardment of 18.7-23.7 mg of 85% enriched Ni-64 has produced 8.9-18.5 GBq of Cu-64 (133 {plus_minus} 10 MBq/{mu}Ahr) with specific activity of 3.5 GBq-11.5 GBq/{mu}g. The amount and specific activity of the Cu-64 produced is more than adequate for both PET and therapy experiments. The Cu-64 produced in more than adequate for both PET and therapy experiments. The Cu-64 had been used to radiolabel PTSM (pyruvaldehyde bis (N4-methylthiosemicarbazone)-used to quantify blood flow), a monoclonal antibody (1A3) and octreotide. An efficient technique for recycling the costly enriched nickel-64 target material has been developed. Nickel eluted off the separation column is collected, boiled to dryness and redissolved in the electroplating bath. Using this method, 94.2 {plus_minus} 3.2% of the Ni-64 has been recovered. The technique described provides a simple, cost-effective method for the cyclotron production of Cu-64.

McCarthy, D.W.; Shefer, R.E.; Klinkowstein, R.E.; Bass, L.A. [Newton Scientific Inc., Winchester, MA (United States)] [and others

1996-05-01

359

Target telemetry in medical isotope production  

NASA Astrophysics Data System (ADS)

Positron emission tomography reveals the biochemical basis underlying many disease processes. The key step is the labeling of authentic metabolic substrates, generally starting with precursor compounds of the short-lived radionuclides 11C, 13N, 15O and 18F. These, in turn, are produced on accelerators, with small cyclotrons now appearing in hospitals. The success of maintaining a reliable source of imaging agents in a clinical setting hinges more on making effective use of modest beams and energies (50 ?A 10 MeV) rather than scaling up the cyclotron in an engineering overkill. Target performance is observed by telemetry of a number of parameters during irradiation. In particular, the neutron flux can be singled out as an immediate signature of the (p, n) reaction, and serves as an important variable to optimize during the bombardment.

Nickles, R. J.; Votaw, J. R.; Hutchins, G. D.; Rosenthal, M. S.; Funk, K. M.; Sunderland, J. J.; Satter, M. R.

1985-05-01

360

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

NASA Astrophysics Data System (ADS)

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.

Avila-Rodriguez, Miguel Angel

361

Microwave-Excited Microplasma Thrusters Using Surface Wave and Electron Cyclotron Resonance Discharges  

NASA Astrophysics Data System (ADS)

Downsizing spacecrafts has recently been focused on to decrease mission costs and to increase launch rates, and missions with small satellites would bring a great advantage of reducing their risks. Such a concept supports a new approach to developing precise, reliable, and low-cost micropropulsion systems. We have studied two types of microwave-excited microplasma thrusters, using surface wave-excited and electron cyclotron resonance-excited discharges. Microwaves of S-band (4 GHz) and X-band (11 GHz) were employed to excite the plasma in these experiments, with the feed or propellant gases of Ar and He. A microplasma thruster of electrothermal type consisted of a surface wave-excited microplasma source, and a converging-diverging micronozzle to obtain the thrust. For 11-GHz microwaves at a power of 6 W, a thrust of 1.1 mN and a specific impulse of 90 s were obtained at an Ar gas flow rate of 40 sccm, where the plasma electron density was 1.2x10^20 m-3, and the gas temperature was 1.5x10^3 K; under the same conditions for 4-GHz microwaves, the thrust, specific impulse, electron density, and gas temperature were 0.93 mN, 80 s, 7.0x10^19 m-3, and 8.0x10^2 K, respectively. A microplasma thruster of electromagnetic type had a microplasma source excited by electron cyclotron resonance with external magnetic fields, to obtain the thrust through accelerating ions by ambipolar electric fields. Optical emission spectrum was dominated by Ar^+ ion lines in the microplasma thruster of electromagnetic type, owing to higher electron temperatures at lower feed-gas pressures.

Mori, Daisuke; Kawanabe, Tetsuo; Takao, Yoshinori; Eriguchi, Koji; Ono, Kouichi

2012-10-01

362

Accelerator science in medical physics  

PubMed Central

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

Peach, K; Wilson, P; Jones, B

2011-01-01

363

Cyclotron resonance precipitation of energetic electrons from the inner magnetosphere  

SciTech Connect

Cyclotron resonance between trapped energetic electrons and VLF waves produces pitch angle scattering which leads to electron precipitation in the inner magnetosphere. Previous experiments have shown that in the drift loss cone at L values from 1.5 to 1.8 energy spectrum of the electrons above 50 keV is often dominated by a single narrow peak. The center energy of this peak varies with L in a manner characteristic of cyclotron resonance between the electrons and monochromatic VLF waves in the vicinity of the geomagnetic equator. The source of the waves is probably VLF communication or navigation transmitters. The authors report the results of a study of 680 occurrences of these peaks detected by the low altitude polar orbiting satellite S81-1. The present data, from altitudes between 170 and 270 km, show the resonance peaks only in two restricted longitude zones centered at 100E and 300E; this result contrasts with the previous measurements at higher altitudes, which detected peaks over a wide range of longitudes. The majority of nighttime events were near transmitter locations where the cyclotron resonance condition was met by electrons with pitch angles near the edge of the loss cone. Detailed study of the events occurring near 100E reveals a 27-day periodicity in the frequency of occurrence; peaks are most often observed during minima in solar/geomagnetic activity. The peaks observed at nighttime in both longitude zones have a possible seasonal variation, being most frequent when it is wintertime at the site of the VLF transmitters responsible for the precipitation.

Datlowe, D.W.; Imhof, W.L. (Lockheed Palo Alto Lab., CA (United States))

1990-05-01

364

Effective production of ??Zn with a PET cyclotron.  

PubMed

Cyclotrons dedicated to the production of PET radiopharmaceuticals for clinical use can be a resource also for research in other fields of science. In the present study we assessed the feasibility of (65)Zn production via the (65)Cu(p,n)(65)Zn reaction using a 16.5 MeV GE-PETtrace biomedical cyclotron. The radioisotope (65)Zn (t(1/2)=244.26 zd; decay mode: EC 98.3%, ?(+) 1.7%) has a wide range of applications, especially in botany and agriculture; its long half life allows storage and delivery to research centers without a cyclotron on site. Natural copper foils (thickness: 100 ?m; purity: >99.9%) were irradiated in a solid target station developed in our institution. The EXFOR and IAEA cross sections databases were carefully studied to optimize the irradiation setup in order to maximize the yield of the radionuclide of interest and minimize the production of isotopic impurities. We performed production runs at 20 ?A for 30 min. Activity was measured using a calibrated HPGe gamma ray detector and an ionization chamber radionuclide activity meter. These measures showed the presence of two main contaminants: (63)Zn (t(1/2)=38.47 min) and (64)Cu (t(1/2)=12.7h); we produced (65)Zn with a saturation yield of (1.06 ± 0.07) GBq/?A (E(p)=12.65?10.48 MeV). The irradiated target was dissolved in 1 ml of 6N HNO(3) at the temperature of 90°C and then purified through anion exchange chromatography with BIO RAD AG 1×8 resin. The radionuclidic purity of the final solution of (65)Zn in HCl 0.005 N, expressed in activity, resulted superior to (99.921 ± 0.003) %. PMID:22732395

Lucconi, G; Cicoria, G; Pancaldi, D; Malizia, C; Marengo, M

2012-04-04

365

Ion cyclotron emission spectroscopy as an. cap alpha. -particle monitor  

SciTech Connect

Since 1981, we have proposed and investigated spectral analysis of the harmonics of ion cyclotron emission (ICE) as a means of monitoring the energy content of ..cap alpha.. particles confined in a magnetic fusion device. A pair of crown probe antennas have been constructed for TFTR to collect ICE spectra and will be installed on that device in the near future. The design of this ICE spectroscopy system is described. Also, some calculations of ICE electromagnetic fluctuations in the ICRF, due to newborn ..cap alpha.. particles with a distribution function appropriate to typical fusion reactor parameters, are discussed. The calculated emission spectra are quite distinct from that of blackbody radiation.

Moses, K.G.; Sperling, J.L.; Dooling, J.C.; Chu, C.

1988-08-01

366

Potential applications of an electron cyclotron resonance multicusp plasma source  

SciTech Connect

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

Tsai, C.C.; Berry, L.A.; Gorbatkin, S.M.; Haselton, H.H.; Roberto, J.B.; Stirling, W.L. (Oak Ridge National Laboratory, Oak Ridge, TN (USA))

1990-05-01

367

Twisted electrostatic ion-cyclotron waves in dusty plasmas.  

PubMed

We show the existence of a twisted electrostatic ion-cyclotron (ESIC) wave carrying orbital angular momentum (OAM) in a magnetized dusty plasma. For our purposes, we derive a 3D wave equation for the coupled ESIC and dust ion-acoustic (DIA) waves from the hydrodynamic equations that are composed of the continuity and momentum equations, together with Poisson's equation. The 3D wave equation reveals the formation of a braided or twisted ESIC wave structure carrying OAM. The braided or twisted ESIC wave structure can trap and transport plasma particles in magnetoplasmas, such as those in Saturn's F-ring and in the forthcoming magnetized dusty plasma experiments. PMID:23410477

Shukla, P K

2013-01-04

368

Does the ion cyclotron exist in the inner corona?  

NASA Astrophysics Data System (ADS)

The present work is about the interpretation of the linear polarization of the O {vi} D_2 (lambda1032 ) coronal line observed by SUMER/SoHO. We take into account the effect of the Doppler redistribution due to the scattering ions motion. We consider the cases of isotropic and anisotropic velocity field distributions. The latter can be interpreted by the ion-cyclotron effect that affects heavy ions in the solar corona. The comparison of the numerical results with the observations yields constraints on the solar wind outflow speed and on the velocity field distribution of the O5+ ions at low coronal altitudes in the polar holes.

Raouafi, N.-E.

369

Beam injection improvement for electron cyclotron resonance charge breeders  

SciTech Connect

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.

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

370

Calibration of electron cyclotron emission radiometer for KSTAR  

SciTech Connect

We developed and installed an electron cyclotron emission radiometer for taking measurements of Korea Superconducting Tokamak Advanced Research (KSTAR) plasma. In order to precisely measure the absolute value of electron temperatures, a calibration measurement of the whole radiometer system was performed, which confirmed that the radiometer has an acceptably linear output signal for changes in input temperature. It was also found that the output power level predicted by a theoretical calculation agrees with that obtained by the calibration measurement. We also showed that the system displays acceptable noise-temperature performance around 0.23 eV.

Kogi, Y. [Fukuoka Institute of Technology, Fukuoka 811-0295 (Japan); Jeong, S. H. [Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Lee, K. D.; Kwon, M. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Akaki, K.; Mase, A. [KASTEC, Kyushu University, Kasuga 816-8580 (Japan); Kuwahara, D. [Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Yoshinaga, T.; Nagayama, Y.; Kawahata, K. [National Institute for Fusion Science, Toki 509-5292 (Japan)

2010-10-15

371

Twisted electrostatic ion-cyclotron waves in dusty plasmas  

NASA Astrophysics Data System (ADS)

We show the existence of a twisted electrostatic ion-cyclotron (ESIC) wave carrying orbital angular momentum (OAM) in a magnetized dusty plasma. For our purposes, we derive a 3D wave equation for the coupled ESIC and dust ion-acoustic (DIA) waves from the hydrodynamic equations that are composed of the continuity and momentum equations, together with Poisson's equation. The 3D wave equation reveals the formation of a braided or twisted ESIC wave structure carrying OAM. The braided or twisted ESIC wave structure can trap and transport plasma particles in magnetoplasmas, such as those in Saturn's F-ring and in the forthcoming magnetized dusty plasma experiments.

Shukla, P. K.

2013-01-01

372

Superthermal electron distribution measurements from polarized electron cyclotron emission  

SciTech Connect

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

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

1988-06-01

373

Cyclotron production of Ac-225 for targeted alpha therapy.  

PubMed

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

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

2005-03-01

374

Experimental monitoring of ozone production in a PET cyclotron facility.  

PubMed

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

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

2010-02-06

375

Generating electron cyclotron resonance plasma using distributed scheme  

SciTech Connect

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.

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

376

Medical futility  

Microsoft Academic Search

Physicians may employ the concept of medical futility to justify a decision not to pursue certain treatments that may be requested\\u000a or demanded by patients or surrogates. Medical futility means that the proposed therapy should not be performed because available\\u000a data show that it will not improve the patient’s medical condition. Medical futility remains ethically controversial for several\\u000a reasons. Some

James L. Bernat

2005-01-01

377

Current drive with fast waves, electron cyclotron waves, and neutral injection in the DIII-D tokamak  

SciTech Connect

Current drive experiments have been performed on the DIII-D tokamak using fast waves, electron cyclotron waves, and neutral injection. Fast wave experiments were performed using a 4-strap antenna with 1 MW of power at 60 MHz. These experiments showed effective heating of electrons, with a global heating efficiency equivalent to that of neutral injection even when the single pass damping was calculated to be as small as 5%. The damping was probably due to the effect of multiple passes of the wave through the plasma. Fast wave current drive experiments were performed with a toroidally directional phasing of the antenna straps. Currents driven by fast wave current drive (FWCD) in the direction of the main plasma current of up to 100 kA were found, not including a calculated 40 kA of bootstrap current. Experiments with FWCD in the counter current direction showed little current drive. In both cases, changes in the sawtooth behavior and the internal inductance qualitatively support the measurement of FWCD. Experiments on electron cyclotron current drive have shown that 100 kA of current can be driven by 1 MW of power at 60 GHz. Calculations with a Fokker-Planck code show that electron cyclotron current drive (ECCD) can be well predicted when the effects of electron trapping and of the residual electric field are included. Experiments on driving current with neutral injection showed that effective current drive could be obtained and discharges with full current drive were demonstrated. Interestingly, all of these methods of current drive had about the same efficiency, 0.015 {times} 10{sup 20} MA/MW/m{sup 2}.

Prater, R.; Petty, C.C.; Pinsker, R.I.; Chiu, S.C.; deGrassie, J.S.; Harvey, R.W.; Ikel, H.; Lin-Liu, Y.R.; Luce, T.C. (General Atomics, San Diego, CA (United States)); James, R.A. (Lawrence Livermore National Lab., CA (United States)); Porkolab, M. (Massachusetts Inst. of Tech., Cambridge, MA (United States)); Baity, F.W.; Goulding, R.H.; Hoffmann, D.J. (Oak Ridge National Lab., TN (United States)); Kawash

1992-09-01

378

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

SciTech Connect

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

Elizarov, L.I.; Ivanov, A.A.; Serebrennikov, K.S.; Vostrikova, E.A. [Russian Research Center 'Kurchatov Institute', 1Kurchatov Square, 123182 Moscow (Russian Federation); Russian Research Center 'Kurchatov Institute', 1 Kurchatov Square, 123182 Moscow, Russia and Peoples Friendship University of Russia, 6 Miklukho-Maklaya Street 117198 Moscow (Russian Federation)

2006-03-15

379

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

SciTech Connect

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

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

1980-03-01

380

Kinetic Models of the Cyclotron Resonant Wave-Particle Interaction in Heliospheric Plasmas  

Microsoft Academic Search

The resonant cyclotron interaction between gyrating ions and MHD waves is fundamental to understanding the behavior of many plasma phenomena in the heliosphere. Close to the Sun, the heating and acceleration of the solar wind in the corona is likely caused by the resonant dissipation of ion cyclotron waves. In the outer heliosphere, the ionization of inflowing interstellar neutrals creates

Philip Isenberg

2006-01-01

381

PARASITIC PITCH-ANGLE DIFFUSION OF RADIATION-BELT PARTICLES BY ION CYCLOTRON WAVES  

Microsoft Academic Search

The resonant pitch angle scattering of protons and electrons by ion cyclotron turbulence is investigated. The analysis is analogous to that recently performed for electron interactions with whistler mode waves. The role played by the intense band of ion cyclotron waves, predicted to be generalted just within the plasmapause during the decay of the magnetospheric ring current, is evaluated in

Lawrence R. Lyons; Richard Mansergh Thorne

1972-01-01

382

Relativistic electron scattering by electromagnetic ion cyclotron ?uctuations: test particle simulations  

Microsoft Academic Search

Abstract. Relativistic electron scattering by electromagnetic ion cyclotron (EMIC) ?uctuations is studied using test particle computations coupled to a hybrid simulation code. The enhanced EMIC ?uctuations are derived from a one-dimensional, self-consistent hybrid simulation model and is due to the growth of the ion cyclotron instability driven by the ion temperature anisotropy, Ti? > Tik, in a magnetized, homogeneous, collisionless

K. Liu; D. S. Lemons; D. Winske; S. P. Gary

2009-01-01

383

Relativistic Electron Scattering by Electromagnetic Ion Cyclotron Fluctuations: Test Particle Simulations  

Microsoft Academic Search

Relativistic electron scattering by electromagnetic ion cyclotron (EMIC) fluctuations is studied using a test particle simulation code. The EMIC fluctuation input comes from a one dimensional, self-consistent hybrid simulation model and is due to the growth of the ion cyclotron instability driven by the ion temperature anisotropy, Ti > Ti, in a magnetized, homogeneous, collisionless plasma with a single ion

Kaijun Liu; Don S. Lemons; Dan Winske; S. Peter Gary

2009-01-01

384

Electron cyclotron maser based on the combination two-wave resonance  

SciTech Connect

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.

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

385

Resonant response of a metallic nanoparticle by collective cyclotron oscillations of electrons and ions  

Microsoft Academic Search

A metal nanoparticle threaded by uniform magnetic field of an ambient matrix responding to an incident electromagnetic wave by collective cyclotron oscillations of electrons and ions is considered. The resonant frequencies of light-induced electron and ion cyclotron oscillations, gyromagnetic plasmons, are obtained followed by a brief discussion of testing these predictions by optical means.

Sergey Bastrukov; Pik-Yin Lai

2005-01-01

386

Diagnosis of mildly relativistic electron velocity distributions by electron cyclotron emission in the Alcator C tokamak  

Microsoft Academic Search

Mildly relativistic electron velocity distributions are diagnosed from measurements of the first few electron cyclotron emission harmonics in the Alcator C tokamak. The approach employs a vertical viewing chord through the center of the tokamak plasma terminating at a compact, high-performance viewing dump. The cyclotron emission spectra obtained in this way are dominated by frequency downshifts due to the relativistic

Kato

1986-01-01

387

Hybrid simulations of wave propagation and ion cyclotron heating in the expanding solar wind  

Microsoft Academic Search

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

Paulett C. Liewer; Marco Velli; Bruce E. Goldstein

1999-01-01

388

Hybrid simulations of wave propagation and ion cyclotron heating in the expanding solar wind  

Microsoft Academic Search

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

Paulett C. Liewer; Marco Velli; Bruce E. Goldstein

1999-01-01

389

A Strong Focussing Ring, as Beam Stretcher for Synchro-Cyclotrons  

Microsoft Academic Search

The possibility of injecting the Synchro-Cyclotron extracted proton beam into a strong focussing ring called CYBEST, is investigated. It is seen that pion beams produced in internal targets of such a device show some advantages with respect to present Synchro-Cyclotron beams. More detailed studies are needed however for final judgement. CYBEST is realizable if a sufficiently fast extraction from the

G. Brianti; P. Skarek

1966-01-01

390

Ion cyclotron harmonic resonances driven by ion ring-beam distributions  

Microsoft Academic Search

Enhanced magnetic fluctuations with frequencies peaking at the ion cyclotron frequency and its harmonics have been observed at Comet Halley and also in the upstream regions of planetary bow shocks. It is thought that these waves are generated at comets by pickup ions that are unstable to the generation of waves at harmonics of the ion cyclotron wave number. In

H. K. Wong; M. L. Goldstein; C. W. Smith

1991-01-01

391

Ion cyclotron harmonic resonances driven by ion ring-beam distributions  

Microsoft Academic Search

Enhanced magnetic fluctuations with frequencies peaking at the ion cyclotron frequency and its harmonics have been observed at comet Halley and also in the upstream regions of planetary bow shocks. It is thought that these waves are generated at comets by pickup ions that are unstable to the generation of waves at harmonics of the ion cyclotron wave number. In

H. K. Wong; M. L. Goldstein; C. W. Smith

1991-01-01

392

Electron cyclotron heating in weakly relativistic finite-beta tandem mirror plasmas  

Microsoft Academic Search

Electron cyclotron resonance frequency wave and absorption theory and ray tracing are reviewed and a numerical model for the study of electron heating in tandem mirror plugs and barriers is presented. It is found that substantial shifts in the spatial energy deposition profile occur from the cold plasma electron cyclotron resonance at elevated temperatures and that surface absorption can be

K. R. Audenaerde; J. E. Scharer

1982-01-01

393

Rapid Current Ramp-Up by Cyclotron-Driving Electrons beyond Runaway Velocity  

Microsoft Academic Search

The toroidal current has been rapidly ramped-up after the formation of an initial closed flux surface in an electron cyclotron heated discharge in the low aspect ratio torus experiment device. A current carrying fast electron tail is developed well beyond the runaway velocity against the reverse voltage from self-induction, suggesting a forward driving force on the tail by the cyclotron

M. Uchida; T. Yoshinaga; H. Tanaka; T. Maekawa

2010-01-01

394

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

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.

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

395

Proton Cyclotron Echo: a Phenomenon of Wave-Wave and Wave-Particle Interactions in Topside Sounding of the Ionosphere  

Microsoft Academic Search

Proton cyclotron echoes are phenomena related to the proton cyclotron frequency discovered on topside sounder swept-frequency ionograms from the Canadian satellite Alouette II in 1969. Subsequent studies were also limited to the use of the swept-frequency ionograms and devoted only to these so called regular proton cyclotron echoes. The regular proton cyclotron echoes occur on the swept-frequency ionograms at constant

Guang-Ming Chen

1993-01-01

396

Principles and Methods of Medical Geographic Mapping.  

National Technical Information Service (NTIS)

Contents: Key problems in mapping in the field of medical geography; Experience in compiling small-scale specialized zoogeographic maps with medical geographic content; Experience in mapping the population of black-legged ticks carriers of natural focal i...

1969-01-01

397

Medical Device Safety  

MedlinePLUS

... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Medical Devices Home Medical Devices Medical Device Safety - Section Contents ... Medical Product Safety Network Emergency Situations (Medical Devices) - Medical Device Safety Search the Medical Device Safety Section Medical ...

398

ARTEMIS-B: A room-temperature test electron cyclotron resonance ion source for the National Superconducting Cyclotron Laboratory at Michigan State University  

Microsoft Academic Search

The current scheme for ion-beam injection into the coupled cyclotron accelerator at the NSCL involves the use of two electron cyclotron resonance (ECR) ion sources. The first one is a 6.4 GHz fully superconducting that will be replaced within two years by SUSI, a third generation 18 GHz superconducting ECR ion source. The other source, ARTEMIS, is a room-temperature source

G. Machicoane; D. Cole; J. Ottarson; J. Stetson; P. Zavodszky

2006-01-01

399

Wave heating models for ion-cyclotron heating in EBT-S  

SciTech Connect

Wave heating of ELMO BUMPY TORUS-SCALE (EBT-S) in the ion-cyclotron range of frequencies will be strongly influenced by the geometry of the plasma. In particular, the short finite length of the mirror sections means that the electron bounce frequency is of comparable magnitude to the ion-cyclotron frequency. Consequently, the bouncing motion of trapped particles impacts the electron absorption of wave energy. Furthermore, the varying magnetic field strength along magnetic field lines influences the ion-cyclotron absorption of waves because the ion-cyclotron resonance conditions are satisfied only at discrete points along the field lines. Expressions are given for trapped and passing electron absorption as well as ion-cyclotron absorption. A numerical example is also discussed.

Sperling, J.L.

1980-05-19

400

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

NASA Astrophysics Data System (ADS)

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

Waltz, R. E.; Deng, Zhao

2013-01-01

401

Mass Measurements with the CSS2 and CIME cyclotrons at GANIL  

SciTech Connect

This paper presents two original direct mass-measurement techniques developed at GANIL using the CSS2 and CIME cyclotrons as high-resolution mass spectrometers. The mass measurement with the CSS2 cyclotron is based on a time-of-flight method along the spiral trajectory of the ions inside the cyclotron. The atomic mass excesses of 68Se and 80Y recently measured with this technique are -53.958(246) MeV and -60.971(180) MeV, respectively. The new mass-measurement technique with the CIME cyclotron is based on the sweep of the acceleration radio-frequency of the cyclotron. Tests with stable beams have been performed in order to study the accuracy of this new mass-measurement method and to understand the systematic errors.

Gomez Hornillos, M. B.; Chartier, M.; Demonchy, C. E. [University of Liverpool, Oliver Lodge Laboratory, L69 7ZE Liverpool (United Kingdom); Mittig, W.; Chautard, F.; Georgiev, G.; Jacquot, B.; Jurado, B.; Lecesne, N.; Rousseau, M.; Roussel-Chomaz, P.; Savajols, H.; Villari, A. C. C. [GANIL, Bld Henri Becquerel, BP 5027, 14076 Caen Cedex 5 (France); Blank, B. [CEN Bordeaux-Gradignan, Le Haut-Vigneau, 33175 Gradignan (France); Caballero, L. [IFIC, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Gillibert, A. [CEA/DSM/DAPNIA/SPhN, CEN Saclay, 91191 Gif-sur-Yvette (France); Lepine-Szily, A. [IFUSP, Caixa Postal 66318, CEP 05315-970 Sao Paulo (Brazil); Orr, N. [LPC, 6 Bld du Marechal Juin, 14050 Caen Cedex (France); Politi, G. [Universita di Catania, 64 Via S. Sofia, 95123 Catania (Italy)

2006-03-13

402

Ion beams of carbon clusters and multiply charged fullerenes produced with electron cyclotron resonance ion sources  

SciTech Connect

The production of carbon cluster ions by injecting C{sub 60} fullerene vapor into different electron cyclotron resonance (ECR) ion sources (MONO1001/2.45 GHz and CAPRICE/14 GHz) is described. The extracted ion mass spectra show a bimodal distribution, well known from collisions between electrons or ions and fullerenes. In addition to small carbon clusters and even-numbered fullerene ions, odd-numbered clusters with (n>30) are detected with low intensities. In particular, we have analyzed the mass spectra as a function of the rf power applied to the ECR plasma. Optimum power values are found for the production of individual carbon cluster ions, which increase with decreasing cluster size. Whereas at low power the production of fullerene ions dominates, the intensity of the very small carbon clusters is found to strongly increase with the injected power. This difference in the power dependence is used to vary and to determine the beam composition for ions with identical mass/charge ratios.

Maunoury, L.; Manil, B.; Rangama, J.; Lebius, H.; Huber, B.A.; Pacquet, J.Y.; Leroy, R.; Pedersen, U.V.; Hvelplund, P.; Jensen, J.; Tomita, S.; Zettergren, H.; Schmidt, H.T.; Cederquist, H.; Gustavo, F. [CIRIL, CEA-CNRS-ENSICAEN-Universite de Caen, BP 5133, F-14070 Caen Cedex 5 (France); GANIL, Bv. Henry Becquerel, BP 55027, F-14076 Caen (France); Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus (Denmark); Division of Ion Physics, A Laboratory, Uppsala University, Box 534, SE-75121, Uppsala (Sweden); Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-0006 (Japan); Physics Department, Stockholm University, AlbaNova University, SE-10691 Stockholm (Sweden); DSM/DRFMC, CEA-Grenoble, 17 rue des martyrs, F-38054 Grenoble Cedex 9 (France)

2005-05-15

403

On the Electron-Cyclotron Maser Instability. II. Pulsations in the Quasi-stationary State  

NASA Astrophysics Data System (ADS)

In the previous paper we have studied the electron-cyclotron maser instability of a source in quasi-equilibrium. In a situation of weak diffusion such a state will remain for a limited time regardless of the particular loss-cone instability involved. Here our major interest is in oscillations set up by small disturbances around the steady state. Both the linear growth as well as the coupled diffusion rate are subject to a common oscillation period, since wave growth and diffusion are interlocked by a Lotka-Volterra type of coupled equations. Periods in the limit of small amplitude (limit cycle) of the self-organizing wave-particle system are investigated for the magnetoionic X- and O-mode and for harmonic numbers s = 1, 2 of the maser instability. Pulsation periods in the order of 1 s, as observed in the decimetric range of solar flare emission are found exist for (1) fundamental (s = 1) O-mode for 0.3 < ?p/?e ? 1.0, and (2) harmonic (s = 2) X-mode (for 1.0 ? ?p/?e 1.4). The period is sensitive to variations of the shape of the loss-cone and therefore not stable. The proposed model provides an interpretation of the observed quasi-periodic decimetric solar pulsations as well as some of similar stellar phenomena.

Aschwanden, M. J.; Benz, A. O.

1988-09-01

404

Superconducting Ring Cyclotron for Riken RI Beam Factory in Japan  

NASA Astrophysics Data System (ADS)

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.

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

2010-04-01

405

The cyclotron resonance klystron: a novel HPM source*  

NASA Astrophysics Data System (ADS)

A novel high power microwave (HPM) device, the cyclotron resonance klystron (CRK), is presented. The interaction relies on enhanced resonant bunching in a highly chromatic transport section between a buncher and a catcher cavity. The chromatic section is a helical wiggler / guide field combination operating close to the cyclotron resonance. The slow group II electrons propagate on long trajectories with a large transverse excursion, while the faster group I electrons have a much shorter transit time, thus resulting in resonantly enhanced bunching. In addition, space-charge effects are alleviated because the beam is spread over a large transverse area. The design parameters of a power amplifier operating at X-band, with an output power in the GW range will be given. Computer simulations of the input and output cavities, electron gun and resonant bunching region, including 3D and space-charge effects will also be presented, as well as a design for a compact, efficient 1/2 GW tube. *Work supported in part by DoD/AFOSR (MURI) F49620-95-1-0253, AFOSR (ATRI) F30602-94-2-001, ARO DAAHO4-95-1-0336 and LLNL/LDRD DoE W-7405-ENG-48

Jackson, C. J.; Le Sage, G. P.; Hartemann, F. V.; Luhmann, N. C., Jr.

1996-11-01

406

Spiral design and beam dynamics for a variable energy cyclotron  

SciTech Connect

Beam-orbit studies were performed for the conversion of the SREL synchrocyclotron magnet for use as a room temperature, multiparticle, isochronous cyclotron. Based on model magnet measurements of field profiles for 8 to 23/sup 0/K gauss hill fields, a four sector spiral pole tip design has been realized which allows all isotope species of heavy ion beams to be accelerated to required final energies. The total spiral angle of 38/sup 0/ allows injection of the beams from the MP tandem into the cyclotron through a valley. The two valey RF system of 140 kV peak accelerates beams on harmonic numbers 2, 3, 4, 6 and 10 at 14 to 21 MHz. Computer calculations indicated acceptable ..nu../sub z/, ..nu../sub r/ and phase space beam characteristics and passing of resonances for typical beams considered: /sup 16/O at 8 and 150 MeV/amu, /sup 60/Ni at 100 MeV/amu and /sup 238/U at 2.5 and 16 MeV/amu. Single turn extraction is achieved with electrostatic deflection.

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

1981-01-01

407

First commissioning results with the Grenoble test electron cyclotron resonance ion source at iThemba LABS  

SciTech Connect

iThemba Laboratory for Accelerator Based Science (iThemba LABS) is a multi-disciplinary accelerator facility. One of its main activities is the operation of a separated-sector cyclotron with a K-value of 200, which provides beams of various ion species. These beams are used for fundamental nuclear physics research in the intermediate energy region, radioisotope production, and medical physics applications. Due to the requirements of nuclear physics for new ion species and higher energies, the decision was made to install a copy of the so-called Grenoble test source (GTS) at iThemba LABS. In this paper, we will report on the experimental setup and the first results obtained with the GTS2 at iThemba LABS.

Thomae, R.; Conradie, J.; Delsink, H.; Du Plessis, H.; Fourie, D.; Klopp, M.; Kohler, I.; Lussi, C.; McAlister, R.; Ntshangase, S.; Sakildien, M. [iThemba LABS, P.O Box 722, Somerset West 7130 (South Africa); Hitz, D. [CEA/DRFMC, 17 Av. Des Martyrs, 38054, Grenoble Cedex 9 (France); Kuechler, D. [CERN, BE/ABP/HSL, 1211 Geneva 23 (Switzerland)

2012-02-15

408

First commissioning results with the Grenoble test electron cyclotron resonance ion source at iThemba LABS  

NASA Astrophysics Data System (ADS)

iThemba Laboratory for Accelerator Based Science (iThemba LABS) is a multi-disciplinary accelerator facility. One of its main activities is the operation of a separated-sector cyclotron with a K-value of 200, which provides beams of various ion species. These beams are used for fundamental nuclear physics research in the intermediate energy region, radioisotope production, and medical physics applications. Due to the requirements of nuclear physics for new ion species and higher energies, the decision was made to install a copy of the so-called Grenoble test source (GTS) at iThemba LABS. In this paper, we will report on the experimental setup and the first results obtained with the GTS2 at iThemba LABS.

Thomae, R.; Conradie, J.; Delsink, H.; Du Plessis, H.; Fourie, D.; Hitz, D.; Klopp, M.; Kohler, I.; Kuechler, D.; Lussi, C.; McAlister, R.; Ntshangase, S.; Sakildien, M.

2012-02-01

409

Use of electron cyclotron resonance x-ray source for nondestructive testing application  

SciTech Connect

Electron cyclotron resonance (ECR) technique is being used for generating x rays in the low-energy region (<150 keV). Recently, the source is used for the calibration of thermoluminescent dosimetry (TLD) badges. In order to qualify the ECR x-ray source for imaging application, the source should give uniform flux over the area under study. Lead collimation arrangement is made to get uniform flux. The flux profile is measured using a teletector at different distance from the port and uniform field region of 10x10 cm{sup 2} has been marked at 20 cm from the x-ray exit port. A digital-to-analog converter (DAC) circuit pack is used for examining the source performance. The required dose for nondestructive testing examination has been estimated using a hospital x-ray machine and it is found to be 0.05 mSv. Our source experimental parameters are tuned and the DAC circuit pack was exposed for nearly 7 min to get the required dose value. The ECR x-ray source operating parameters are argon pressure: 10{sup -5} Torr, microwave power: 350 W, and coil current: 0 A. The effective energy of the x-ray spectrum is nearly 40 keV. The x-ray images obtained from ECR x-ray source and hospital medical radiography machine are compared. It is found that the image obtained from ECR x-ray source is suitable for NDT application.

Baskaran, R.; Selvakumaran, T.S. [Radiological Safety Division, Safety Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

2006-03-15

410

Use of electron cyclotron resonance x-ray source for nondestructive testing application  

NASA Astrophysics Data System (ADS)

Electron cyclotron resonance (ECR) technique is being used for generating x rays in the low-energy region (<150 keV). Recently, the source is used for the calibration of thermoluminescent dosimetry (TLD) badges. In order to qualify the ECR x-ray source for imaging application, the source should give uniform flux over the area under study. Lead collimation arrangement is made to get uniform flux. The flux profile is measured using a teletector at different distance from the port and uniform field region of 10×10 cm2 has been marked at 20 cm from the x-ray exit port. A digital-to-analog converter (DAC) circuit pack is used for examining the source performance. The required dose for nondestructive testing examination has been estimated using a hospital x-ray machine and it is found to be 0.05 mSv. Our source experimental parameters are tuned and the DAC circuit pack was exposed for nearly 7 min to get the required dose value. The ECR x-ray source operating parameters are argon pressure: 10-5 Torr, microwave power: 350 W, and coil current: 0 A. The effective energy of the x-ray spectrum is nearly 40 keV. The x-ray images obtained from ECR x-ray source and hospital medical radiography machine are compared. It is found that the image obtained from ECR x-ray source is suitable for NDT application.

Baskaran, R.; Selvakumaran, T. S.

2006-03-01

411

Plasma-Sheath Instability in Hall Thrusters Due to Periodic Modulation of the Energy of Secondary Electrons in Cyclotron Motion  

SciTech Connect

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 quasi-periodical 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.

D. Sydorenko and A. Smolyakov I. Kaganovich and Y. Raitses

2008-04-23

412

COMPLETE SUPPRESSION OF THE M=2/N-1 NEOCLASSICAL TEARING MODE USING ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D  

SciTech Connect

A271 COMPLETE SUPPRESSION OF THE M=2/N-1 NEOCLASSICAL TEARING MODE USING ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D. The first suppression of the important and deleterious m=2/n=1 neoclassical tearing mode (NTM) is reported using electron cyclotron current drive (ECCD) to replace the ''missing'' bootstrap current in the island O-point. Experiments on the DIII-D tokamak verify the maximum shrinkage of the m=2/n=1 island occurs when the ECCD location coincides with the q = 2 surface. The DIII-D plasma control system is put into search and suppress mode to make small changes in the toroidal field to find and lock onto the optimum position, based on real time measurements of dB{sub {theta}}/dt, for complete m=2/n=1 NTM suppression by ECCD. The requirements on the ECCD for complete island suppression are well modeled by the modified Rutherford equation for the DIII-D plasma conditions.

PETTY,CC; LAHAYE,LA; LUCE,TC; HUMPHREYS,DA; HYATT,AW; PRATER,R; STRAIT,EJ; WADE,MR

2003-03-01

413

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.

2006-11-01

414

Medical confidence.  

PubMed Central

If medical confidentiality is not observed patients may well be reluctant to disclose information to their doctors or even to seek medical advice. Therefore, argues the author, it is of the utmost importance that doctors strive to protect medical confidentiality, particularly now when it is under threat not only in this country but also overseas. The profession must cease to regard ethical issues to do with confidentiality, and indeed to do with all areas of medical practice, as abstract phenomena requiring no justification. If it does not then it will come under increasing and justified criticism from the community it serves.

Havard, J

1985-01-01

415

Electron cyclotron emission imaging and applications in magnetic fusion energy  

NASA Astrophysics Data System (ADS)

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

Tobias, Benjamin John

416

Formation of a large-area uniform ion beam using multipole magnets in the TIARA cyclotron  

NASA Astrophysics Data System (ADS)

The formation of an ion beam with a uniform transverse intensity distribution based on a nonlinear focusing method has been studied at the azimuthally varying field cyclotron facility of Japan Atomic Energy Agency. The method enables us to perform uniform irradiation at a constant particle fluence rate over the whole area of a large sample. To obtain a large-area highly uniform beam on the target, we first smooth the intensity distribution of the beam from the cyclotron by multiple scattering and then focus the smoothed beam using octupole magnets. An efficient technique to enhance the scattering effect with a small energy loss is discussed. By collimating the tail of the smoothed beam before octupole focusing, a beam with a nearly uniform profile can be attained on the target. Moreover, we also show that a misaligned beam can be transformed into a uniform beam by adding sextupole focusing. The possibility of ultra-short-time and ultra-low-fluence irradiation has been demonstrated toward advanced applications in materials and biological science. The characteristics of the uniform beam produced by the nonlinear focusing method are discussed from the viewpoint of a uniform irradiation method as compared to other conventional methods.KeywordsOctupole magnetSextupole magnetUniform irradiationIon beamBeam transport systemIon-beam applicationReferencesA.M.KoehlerR.J.SchneiderJ.M.SistersonMed. Phys.41977297T.R.RennerW.T.ChuMed. Phys.141987825Th.HabererW.BecherD.SchardtG.KraftNucl. Instr. and Meth. Phys. Res. Sect. A3301993296M.FukudaS.OkumuraK.ArakawaNucl. Instr. and Meth. Phys. Res. Sect. A396199745N.TsoupasL.AhrensS.BellaviaR.BonatiK.A.BrownI-HungChiangC.J.GardnerD.GassnerS.JaoW.W.MackayI.MarnerisW.MengD.PhillipsP.PileR.PriglA.RusekL.SnydstrupK.ZenoPhys. Rev. ST Accel. Beams102007024701P.F.MeadsJr.IEEE Trans. Nucl. Sci.NS-3019832838Y.YuriN.MiyawakiT.KamiyaW.YokotaK.ArakawaM.FukudaPhys. Rev. ST Accel. Beams102007104001H.WiedemannParticle Accelerator Physicsthird ed.2007Springer-VerlagBerlin, HeidelbergK. Arakawa, Y. Nakamura, W. Yokota, M. Fukuda, T. Nara, T. Agematsu, S. Okumura, I. Ishibori, T. Karasawa, R. Tanaka, A. Shimizu, T. Tachikawa, Y. Hayashi, K. Ishii, and T. Satoh, in: Proceedings of the 13th International Conference on Cyclotrons and their Applications, Vancouver, Canada, 1992, p. 119.T.AgematsuH.HanayaT.KojimaRadioisotopes57200887[in Japanese]E.SegrèNuclei and Particlessecond ed.1977W.A. Benjamin, Inc.Reading, MassachusettsThe achievable size of the uniform beam is currently limited by the size of the vacuum window. The installation of an experimental vacuum chamber at the target is under way for a larger-area uniform beam and some applications.G.R.LynchO.I.DahlNucl. Instr. and Meth. Phys. Res. Sect. B5819916T. Ishizaka, S. Okumura, I. Ishibori, T. Yuyama, and Y. Yuri, JAEA Takasaki Annual Report 2007, JAEA-Review 2008-055, 2008, p. 184.The required octupole force is almost independent of the final beam size on the target as long as the phase advance ? from the octupole magnet to the target is unchanged [see Eq. (2)]. Actually, the variation of ? is small since the beta function near the target is large.

Yuri, Yosuke; Ishizaka, Tomohisa; Yuyama, Takahiro; Ishibori, Ikuo; Okumura, Susumu; Yoshida, Ken-Ichi

2011-06-01

417

Reduction of Axial Kinetic Energy Induced Perturbations on Observed Cyclotron Frequency  

PubMed Central

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

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

2008-01-01

418

Enhanced confinement in electron cyclotron resonance ion source plasma  

SciTech Connect

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.

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

419

Observation of the backward electrostatic ion cyclotron wave  

SciTech Connect

The backward branch of the electrostatic ion cyclotron wave has been observed, we believe, for the first time. The wave, which was driven by a phased antenna structure inserted in a neon plasma, exists in the parameter ranges 2T/sub i//m/sub i/ << (..omega../k/sub parallel/)/sup 2/ << 2T/sub e//m/sub e/, n..cap omega../sub i/ < ..omega.. < (n+1)..cap omega../sub i/, T/sub e/ greater than or equal to T/sub i/, and ..omega../sub pi/ > ..cap omega../sub i/. Double-tip probe interferomety data agree with the theoretical dispersion relation.

Goree, J.; Ono, M.; Wong, K.L.

1984-12-01

420

Potential applications of an electron cyclotron resonance multicusp plasma source  

SciTech Connect

An electric cyclotron resonance (ECR) multicusp plasmatron has been developed by feeding a multicusp bucket arc chamber with a compact ECR plasma source. This novel source produces large (about 25-cm- diam), uniform (to within {plus minus}10%), dense (>10{sup 11}--cm{sup {minus}3}) plasmas of argon, helium, hydrogen, and oxygen. It has been operated to produce an oxygen plasma for etching 12.7-cm (5-in.) positive photoresist-coated silicon wafers with uniformity within {plus minus}8%. Following a brief review of the large plasma source developed at Oak Ridge National Laboratory, the configuration and operation of the source are described and a discharge model is presented. Results from this new ECR plasma source and potential applications for plasma processing of thin films are discussed. 21 refs., 10 figs.

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

1990-03-01

421

Charge-state distributions of metallic electron cyclotron resonance plasmas  

SciTech Connect

The authors have developed metallic ion beams in the energy range of a few keV to a few MeV using a low-energy ion-beam facility (LEIBF) consisting of a 10 GHz all-permanent-magnet electron cyclotron resonance (ECR) ion source placed on a high-voltage (200 kV) platform. The metallic vapors were achieved by plasma sputtering, using a micro-oven and volatile compounds to produce multiply charged ECR plasma. The ions were then extracted from the plasma and their energy and momentum were analyzed using a high-resolution dipole magnet. Charge-state distributions (CSDs) of three metallic ECR plasmas (Cu, Ni, and Sn) produced by different techniques are presented to help in using low-energy metallic ions for implantation. We present the CSD studies of metallic ECR plasma and highlight the physics of the process involved.

Kumar, P.; Rodrigues, G.; Lakshmy, P. S.; Kanjilal, D.; Kumar, R. [Inter University Accelerator Centre, New Delhi 110067 (India); Department of Physics, Ch. Charan Singh University, Meerut 250004 (U.P.) (India)

2008-01-15

422

Charge Reversal Fourier Transform Ion Cyclotron Resonance Mass Spectrometry  

NASA Astrophysics Data System (ADS)

We report the first charge reversal experiments performed by tandem-in-time rather than tandem-in-space MS/MS. Precursor odd-electron anions from fullerene C60, and even-electron ions from 2,7-di- tert-butylfluorene-9-carboxylic acid and 3,3'-bicarbazole were converted into positive product ions (-CR+) inside the magnet of a Fourier transform ion cyclotron resonance mass spectrometer. Charge reversal was activated by irradiating precursor ions with high energy electrons or UV photons: the first reported use of those activation methods for charge reversal. We suggest that high energy electrons achieve charge reversal in one step as double electron transfer, whereas UV-activated -CR+ takes place stepwise through two single electron transfers and formally corresponds to a neutralization-reionization (-NR+) experiment.[Figure not available: see fulltext.

Lobodin, Vladislav V.; Savory, Joshua J.; Kaiser, Nathan K.; Dunk, Paul W.; Marshall, Alan G.

2013-02-01

423

Superconducting magnet for K-500 cyclotron at VECC, Kolkata  

NASA Astrophysics Data System (ADS)

K-500 superconducting cyclotron is in the advanced stage of commissioning at VECC, Kolkata. Superconducting magnet is one of the major and critical component of the cyclotron. It has been successfully fabricated, installed, cooled down to 4.2 K by interfacing with LHe plant and energized to its rated current on 30th April, 2005 producing magnetic field of 4.8 T at median plane of cyclotron. The superconducting magnet (stored energy of 22MJ) consists of two coils (? and ?), which were wound on a sophisticated coil winding machine set-up at VECC. The superconducting cable used for winding the coils is multi filamentary composite superconducting wire (1.29 mm diameter) having 500 filaments of 40 ?m diameter Nb-Ti in copper matrix which is embedded in OFHC grade copper channel (2.794 mm × 4.978 mm) for cryogenic stability. The basic structure of coil consists of layer type helical winding on a SS bobbin of 1475 mm ID × 1930 mm OD × 1170 mm height. The bobbin was afterwards closed by SS sheet to form the LHe chamber. The total weight of the coil with bobbin was about 6 tonne and the total length of the superconducting cable wound was about 35 km. Winding was done at very high tension (2000 PSI) and close tolerance to restrict the movement of conductor and coil during energization. After coil winding, all four coils (two each on upper and lower half of median plane of cyclotron) were banded by aluminium strip (2.7 mm × 5 mm) at higher tension (20,000 PSI) to give more compressive force after cool down to 4.2 K for restricting the movement of coil while energizing and thereby eliminating the chances of quench during ramping of current. After completion of coil winding by October, 2003, cryostat assembly was taken up in house. The assembly of cryostat (13 tonne) with support links (9 Nos.) refrigeration port, instrumentation port, helium vapour cooled current loads, etc. was completed by June, 2004. Meanwhile assembly of magnet frame was taken up and the cryostat was positioned in the magnet frame with proper alignment by August, 2004. After installation of cryostat on magnet, the cryostat was connected to the helium refrigerator/liquefier, having refrigeration capacity of 200 W and 100 l/h in liquefier mode with LN2 pre-cooling. The cryogenic delivery system supplying the liquid helium and liquid nitrogen to the superconducting magnet was successfully commissioned in November, 2004. The cool down of the cryostat to 10 K took around 8 days following which the LHe was filled in the cryostat (300 l) on 15th January, 2005. Subsequently the superconducting coils (? and ?) were energized by two DC current regulated power supplies (20 V, 1000 A, 10 ppm stability) with slow and fast dump resistors connected externally across the superconducting coils for protection of coils at the time of power failure and quench. The paper describes the intricacies involved in coil winding, winding set-up, assembly of cryostat, cooling down the superconducting coils, filling by LHe and energization to rated current. The paper also highlights the operating experience of superconducting magnet and related test results.

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

2009-06-01

424

Determination of the Electron Cyclotron Current Drive Profile  

SciTech Connect

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

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

1999-11-01

425

Characteristics of microinstabilities in electron cyclotron and ohmic heated discharges  

SciTech Connect

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

Pusztai, I.; Moradi, S.; Fueloep, T. [Department of Applied Physics, Nuclear Engineering, Chalmers University of Technology and Euratom-VR Association, Goeteborg (Sweden); Timchenko, N. [Institute of Tokamak Physics, NRC ''Kurchatov Institute,'' 123182, Kurchatov Sq. 1, Moscow (Russian Federation)

2011-08-15

426

Electrostatic ion-cyclotron heating of solar atmosphere  

NASA Astrophysics Data System (ADS)

Some consequences of current dissipation in the coronal magnetic loops are studied. Particular attention is paid to the electrostatic ion-cyclotron (ESIC) instability, which possesses a self-limiting heating mechanism and which can be excited with a lower electron drift velocity than the Buneman instability. A current-carrying loop will have nonsymmetric temperature and density distributions across the top of the loop. When the electron drift velocity is near or above the critical value for the ESIC instability, the plasma will be heated to a temperature of up to a few million kelvins if the electron density is approximately 100 million per cubic cm and the height of the loop is approximately 1 billion cm. Furthermore, the ion temperature will be as much as a factor of 2 higher than the electron temperature if the ESIC instability criterion is satisfied. Otherwise, the ion and the electron temperatures will be the same.

Hinata, S.

1980-01-01

427

Cyclotron Resonance in Graphene at Ultrahigh Magnetic Fields  

NASA Astrophysics Data System (ADS)

To investigate the effects of intentional and unintentional doping on the conduction properties of CVD-grown large-area graphene, we have performed high-field cyclotron resonance (CR) measurements on graphene. We accessed ultrahigh magnetic fields using the Single-Turn Coil System at NHMFL-Los Alamos, which can produce peak fields over 300 T in ˜2.5 ?s pulses. We investigated magneto-infrared transmission at 10.6 ?m in pulsed ultrahigh magnetic fields up to 170 T for a variety of graphene samples on KRS-5 substrates with different levels of doping. Circularly polarized CO2 light was used to determine the carrier type of the doping, and temperature-dependent measurements were also performed. We observed a clear CR peak at ˜50 T corresponding to the n = 1 to n = 2 Landau level transition, which indicates that the Fermi energy measured from the Dirac point has to be ˜250-400 meV.

Booshehri, L. G.; Mielke, C. H.; Crooker, S. A.; Ren, L.; Haroz, E. H.; Jin, Z.; Sun, Z.; Yan, Z.; Tour, J. M.; Kono, J.

2011-03-01

428

The technology of the ion cyclotron range of frequencies  

SciTech Connect

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

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

1988-01-01

429

KEKCB electron cyclotron resonance charge breeder at TRIAC  

NASA Astrophysics Data System (ADS)

The KEKCB is an electron cyclotron resonance (ECR) ion source for converting singly charged ions to multicharged ones at Tokai Radioactive Ion Accelerator Complex. By using the KEKCB, singly charged gaseous and nongaseous ions were converted to multicharged ones of A/q~=7 with efficiencies of 7% and 2%, respectively. The conversion efficiency was found to be independent of the lifetime of the radioactive nuclei having lifetimes of the order of one second. Three collimators located at the entrance and the exit of the KEKCB defined the beam axis and facilitated beam injection. Grinding and washing the surfaces of aluminum electrode and plasma chamber dramatically reduced impurities originating from the ECR plasma of the KEKCB.

Imai, N.; Jeong, S. C.; Oyaizu, M.; Arai, S.; Fuchi, Y.; Hirayama, Y.; Ishiyama, H.; Miyatake, H.; Tanaka, M. H.; Okada, M.; Watanabe, Y. X.; Ichikawa, S.; Kabumoto, H.; Osa, A.; Otokawa, Y.; Sato, T. K.

2008-02-01

430

KEKCB electron cyclotron resonance charge breeder at TRIAC  

SciTech Connect

The KEKCB is an electron cyclotron resonance (ECR) ion source for converting singly charged ions to multicharged ones at Tokai Radioactive Ion Accelerator Complex. By using the KEKCB, singly charged gaseous and nongaseous ions were converted to multicharged ones of A/q{approx_equal}7 with efficiencies of 7% and 2%, respectively. The conversion efficiency was found to be independent of the lifetime of the radioactive nuclei having lifetimes of the order of one second. Three collimators located at the entrance and the exit of the KEKCB defined the beam axis and facilitated beam injection. Grinding and washing the surfaces of aluminum electrode and plasma chamber dramatically reduced impurities originating from the ECR plasma of the KEKCB.

Imai, N.; Jeong, S. C.; Oyaizu, M.; Arai, S.; Fuchi, Y.; Hirayama, Y.; Ishiyama, H.; Miyatake, H.; Tanaka, M. H.; Okada, M.; Watanabe, Y. X.; Ichikawa, S.; Kabumoto, H.; Osa, A.; Otokawa, Y.; Sato, T. K. [High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Japan Atomic Energy Agency (JAEA), Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan)

2008-02-15

431

KEKCB electron cyclotron resonance charge breeder at TRIAC.  

PubMed

The KEKCB is an electron cyclotron resonance (ECR) ion source for converting singly charged ions to multicharged ones at Tokai Radioactive Ion Accelerator Complex. By using the KEKCB, singly charged gaseous and nongaseous ions were converted to multicharged ones of A/q approximately 7 with efficiencies of 7% and 2%, respectively. The conversion efficiency was found to be independent of the lifetime of the radioactive nuclei having lifetimes of the order of one second. Three collimators located at the entrance and the exit of the KEKCB defined the beam axis and facilitated beam injection. Grinding and washing the surfaces of aluminum electrode and plasma chamber dramatically reduced impurities originating from the ECR plasma of the KEKCB. PMID:18315161

Imai, N; Jeong, S C; Oyaizu, M; Arai, S; Fuchi, Y; Hirayama, Y; Ishiyama, H; Miyatake, H; Tanaka, M H; Okada, M; Watanabe, Y X; Ichikawa, S; Kabumoto, H; Osa, A; Otokawa, Y; Sato, T K

2008-02-01

432

Anomalous galvanomagnetism, cyclotron resonance, and microwave spectroscopy of topological insulators  

NASA Astrophysics Data System (ADS)

The surface quantum Hall state, magnetoelectric phenomena, and their connection to axion electrodynamics have been studied intensively for topological insulators. One of the obstacles for observing such effects comes from nonzero conductivity of the bulk. To overcome this obstacle, we propose to use an external magnetic field to suppress the conductivity of the bulk carriers. The magnetic field dependence of galvanomagnetic and electromagnetic responses of the whole system shows anomalies due to broken time-reversal symmetry of the surface quantum Hall state, which can be used for its detection. In particular, we find negative linear dc magnetoresistivity and a quadratic field dependence of the Hall angle, shifted rf cyclotron resonance, nonanalytic microwave transmission coefficient, and saturation of the Faraday rotation angle with increasing magnetic field or wave frequency.

Tkachov, G.; Hankiewicz, E. M.

2011-07-01

433

Concept for a fourth generation electron cyclotron resonance ion source  

SciTech Connect

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{sub 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.

Lyneis, C.; Ferracin, P.; Caspi, S.; Hodgkinson, A.; Sabbi, G. L. [Lawrence Berkeley National Laboratory, Berkeley, California 94708 (United States)

2012-02-15

434

Medication reviews  

PubMed Central

Recent years have seen a formalization of medication review by pharmacists in all settings of care. This article describes the different types of medication review provided in primary care in the UK National Health Service (NHS), summarizes the evidence of effectiveness and considers how such reviews might develop in the future. Medication review is, at heart, a diagnostic intervention which aims to identify problems for action by the prescriber, the clinican conducting the review, the patient or all three but can also be regarded as an educational intervention to support patient knowledge and adherence. There is good evidence that medication review improves process outcomes of prescribing including reduced polypharmacy, use of more appropriate medicines formulation and more appropriate choice of medicine. When ‘harder’ outcome measures have been included, such as hospitalizations or mortality in elderly patients, available evidence indicates that whilst interventions could improve knowledge and adherence they did not reduce mortality or hospital admissions with one study showing an increase in hospital admissions. Robust health economic studies of medication reviews remain rare. However a review of cost-effectiveness analyses of medication reviews found no studies in which the cost of the intervention was greater than the benefit. The value of medication reviews is now generally accepted despite lack of robust research evidence consistently demonstrating cost or clinical effectiveness compared with traditional care. Medication reviews can be more effectively deployed in the future by targeting, multi-professional involvement and paying greater attention to medicines which could be safely stopped.

Blenkinsopp, Alison; Bond, Christine; Raynor, David K

2012-01-01

435

Amplitudes of electron cyclotron waves transmitted in the ionosphere  

NASA Astrophysics Data System (ADS)

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

James, H. G.

2011-07-01

436

Advantages of the LBL 88-inch cyclotron ion beam for SEP studies  

NASA Astrophysics Data System (ADS)

The Lawrence Berkeley Laboratory 88-inch cyclotron has been widely used for single-event phenomena (SEP) studies. The advantages and disadvantages of using ions at this facility are compared with those for other accelerator facilities in the U.S. One major advantage of the 88-inch cyclotron is that several ion species, with varying stopping powers, can be made available in a matter of seconds by simply adjusting the cyclotron frequency. The importance of this capability is illustrated via test results for a high-density SRAM and an EEPROM device type.

Koga, Rocky; Pinkerton, Steven D.

1993-09-01

437

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

PubMed

At CIAE, a 100 MeV H(-) cyclotron (CYCIAE-100) is under design and construction. A central region model (CRM) cyclotron was built for various experimental verifications for the CYCIAE-100 project and for research and development of high current injection to accelerate milliampere H(-) beam. The H(-) multicusp source built in 2003 has been improved recently to make the source operation more stable. A new injection line for axial low energy high current injection has been designed and constructed for the CRM cyclotron. PMID:18315258

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

2008-02-01

438

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

SciTech Connect

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

Zhang Tianjue; Li Zhenguo; Lu Yinlong; Wei Sumin; Cai Hongru; Ge Tao; Wu Longcheng; Pan Gaofeng; Yao Hongjuan; Kuo, T.; Yuan, D. [China Institute of Atomic Energy, Beijing 102413 (China); China Institute of Atomic Energy, Beijing 102413 (China) and Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); TRIUMF, 4004 Wesbrook Mall, Vancouver, B.C. V6T 2A3 (Canada)

2008-02-15

439

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

NASA Astrophysics Data System (ADS)

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

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

2008-02-01

440

Transport code studies of m=2 mode control by local electron cyclotron heating in TFR  

NASA Astrophysics Data System (ADS)

Transport code simulations of TFR experiments were carried out to determine whether positive results obtained by local electron cyclotron heating are indeed a consequence of profile tailoring. The evolution of the m=2, n=1 tearing mode was evaluated for cylindrical geometry using quasi-linear theory. The conclusion is that the suppression of the magnetohydrodynamic activity with electron cyclotron heating on TFR cannot be due to current profile tailoring alone. The most probable cause is the effect of electron cyclotron heating on the plasma position.

Westerhof, E.; Goedheer, W. J.

1988-06-01

441

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

SciTech Connect

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.

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

442

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

SciTech Connect

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.

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

443

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

SciTech Connect

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.

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

444

Local and global properties of plasma waves at the proton cyclotron frequency upstream from Mars  

NASA Astrophysics Data System (ADS)

A comprehensive study on the properties of electromagnetic ULF plasma waves upstream from Mars is presented. This study is based on reliable upstream measurements provided by the magnetometer and electron reflectometer (MAG/ER) onboard the Mars Global Surveyor (MGS) spacecraft during the Science Phasing Orbit period. We find that a large majority of these waves is characterized - in the spacecraft frame - by a left-hand circular polarization and a frequency which coincides with the local proton cyclotron frequency. Minimum variance analysis of the magnetic field indicates that these waves propagate almost parallel to the background magnetic field and comparison with suprathermal electron fluxes measured by ER suggests a small degree of compressibility. A survey based on more than 300 MGS elliptical orbits indicates that these waves are almost permanent and their spatial distribution does not seem to depend on the orientation of the solar wind convective electric field assuming a flow along the Sun-Mars line. Also, we find that their amplitude decreases with radial distance from the planet, supporting the idea that their source is Mars. Theoretical (analytical and numerical) approaches suggest that these properties are compatible with plasma waves originating in the pick-up of ionized exospheric hydrogen. We discuss these theoretical results and their implications for Mars and other atmospheric unmagnetized objects such as Venus.

Romanelli, N.; Bertucci, C.; Gomez, D. O.; Mazelle, C. X.; Delva, M.; Cowee, M.

2011-12-01

445

Bursts in Electron Cyclotron Emission During ELMs and EHOs in Tokamaks  

NASA Astrophysics Data System (ADS)

Electron cyclotron emission (ECE) bursts during edge localized modes (ELMs) have been observed and reported in several tokamaks. A number of possible explanations have been suggested, but none describe completely the observed ECE bursts. A key to understanding these bursts is that they always occur during edge MHD activity such as ELMs or EHOs in QH-mode plasmas. Other observed properties are that the ECE bursts appear on the low-field-side with an intensity of several tens or hundreds times the thermal emission level, and with a bandwidth as narrow as the instrumental filter spacing of 400 MHz or narrower. A model based on the basic emission and absorption relationship of ECE in plasma is put forth. We calculate the radiation temperature for different electron velocity distribution functions, but with a small variable resonance frequency within the instrumental bandwidth. The resulting radiation temperature and its spectral width agree well with experimental observations both in non-Maxwellian and Maxwellian distribution, but the radiation temperature in non-Maxwellian case is much higher.

Li, E.; Austin, M. E.

2012-10-01

446

Development of gas pulsing system for electron cyclotron resonance ion source  

SciTech Connect

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.

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

447

Propagation of metal vapor vacuum arc ions into electron cyclotron resonance ion sources  

NASA Astrophysics Data System (ADS)

A metal vapor vacuum arc (Mevva) ion source was finally installed and operated inside the electron cyclotron resonance (ECR) ion source Alice; Mevva cathode was made of Al, while ECR buffer gas was nitrogen, and among residuals, argon. Installation, hardware control, and improvements of diagnostic are discussed. Magnetic analysis of the ECR emitted current shows the presence of an Al3+ peak of about 5-10 ?A following Mevva pulse end after 15 ?s, against a steady state current of 10 nA. Peak width is about 5 ?s, which is the limit of our current amplifier. Peak remains when ECR is turned off. Application of a bias potential of +/-46 V to the Mevva anode shows fairly small effects on time of flight, which may indicate a large kinetic energy of Mevva ions (280 eV) at the end of Mevva shot. Bias voltage and ECR operation proved compatible only at low power, in present installation; then, some or most of Mevva ions are not trapped inside the ECR.

Cavenago, M.; Kulevoy, T.; Vassiliev, A.

1998-02-01

448

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

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.

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

449

Rapid host nation medical deployment.  

PubMed

Rapid development of land-based units in Operation Desert Shield/Storm presented critical needs for medical support. Integration of small Navy mobile medical teams in Bahrain and a larger United States Army Hospital unit in Riyadh, Saudi Arabia, at host nation hospitals presented an innovative method of providing this support. The success of these ventures in convenience and quality of care establishes the host nation interaction with military medical professionals as a workable, satisfying, and important adjunct to standard military medical care. PMID:1470355

Ludwig, F E; Horak, B J; Wallace, M R; Deafenbaugh, M K

1992-11-01

450

Multipurpose superconducting electron cyclotron resonance ion source, the European roadmap to third-generation electron cyclotron resonance ion sources  

SciTech Connect

The major infrastructures of nuclear physics in Europe adopted the technology of electron cyclotron resonance (ECR) ion sources for the production of heavy-ion beams. Most of them use 14 GHz electron cyclotron resonance ion sources (ECRISs), except at INFN-LNS, where an 18 GHz superconducting ECRIS is in operation. In the past five years it was demonstrated, in the frame of the EU-FP5 RTD project called ''Innovative ECRIS,'' that further enhancement of the performances requires a higher frequency (28 GHz and above) and a higher magnetic field (above 2.2 T) for the hexapolar field. Within the EU-FP6 a joint research activity named ISIBHI has been established to build by 2008 two different ion sources, the A-PHOENIX source at LPSC Grenoble, reported in another contribution, and the multipurpose superconducting ECRIS (MS-ECRIS), based on fully superconducting magnets, able to operate in High B mode at a frequency of 28 GHz or higher. Such a development represents a significant step compared to existing devices, and an increase of typically a factor of 10 for the intensity is expected (e.g., 1 emA for medium charge states of heavy ions, or hundreds of e{mu}A of fully stripped light ions, or even 1 e{mu}A of charge states above 50{sup +} for the heaviest species). The challenging issue is the very high level of magnetic field, never achieved by a minimum B trap magnet system; the maximum magnetic field of MS-ECRIS will be higher than 4 or 5 T for the axial field and close to 2.7 T for the hexapolar field. The detailed description of the MS-ECRIS project and of its major constraints will be given along with the general issues of the developments under way.

Ciavola, G.; Gammino, S.; Celona, L.; Torrisi, L.; Passarello, S.; Ando, L.; Cavenago, M.; Galata, A.; Spaedtke, P.; Tinschert, K.; Lang, R.; Iannucci, R.; Leroy, R.; Barue, C.; Hitz, D.; Seyfert, P.; Koivisto, H.; Suominen, P.; Tarvainen, O.; Beijers, H. [Istituto Nazionale Fisica Nucleare-Laboratori Nazionali del Sud (INFN-LNS), Via S. Sofia 62, 95123 Catania (Italy) and INFN-Laboratori Nazionali di Legnaro (INFN-LNL), 35020 Legnaro (Italy); Gesellschaft fuer Schwerionenforschung mbH (GSI), 64291 Darmstadt (Germany); Grand Accelerateur National d'Ions Lourds (GANIL), 14076 Caen (France); CEA-DRFMC-SBT, 38054 Grenoble (France); Department of Physics, University of Jyvaeskylae (JYFL), 40014 Jyvaeskylae (Finland); Kernfysisch Versneller Instituut (KVI), 9747 AA Groningen (Netherlands); Svedberg Laboratory (TSL), 75121 Uppsala (Sweden); CERN AB Department, CERN CH-1211 Geneva (Switzerland); Hahn Meitner Institut Berlin GmbH (HMI), 14109 Berlin (Germany); National Institute of Physics and Nuclear Engineering (NIPNE), MG-6, Bucharest-Magurele (Romania)] (and others)

2006-03-15

451

Medical pleuroscopy.  

PubMed

There has been an exciting expansion in the practice of medical pleuroscopy in recent years. As technology has become more available and confidence in the use of equipment has grown, medical thoracoscopy has become a core diagnostic and therapeutic tool in pleural disease care. Despite this, many areas of medical pleuroscopy practice remain conspicuously devoid of well-established evidence. More knowledge is needed in those areas where there is currently a degree of equipoise. Many areas where pleuroscopy currently has a marginal role require high-quality randomized trials be undertaken with a view to informing future practice and guidelines. PMID:23993819

Bhatnagar, Rahul; Maskell, Nick A

2013-06-18

452

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

Federal Register 2010, 2011, 2012, 2013

...Applicant: National Superconducting Cyclotron Laboratory of Michigan State University. Instrument: Radio Frequency Quadropole Accelerator (RFQ). Manufacturer: Institut fur Angewandte Physik, Germany. Intended Use: See notice at 75 FR 40775, July...

2010-08-12

453

Radioactive Beams Using the AECR-U and the 88-Inch Cyclotron  

SciTech Connect

The high ionization efficiency of an Electron Cyclotron Resonance (ECR) ion source combined with the mass resolution of a cyclotron is ideal for the generation of some ISOL-type radioactive ion beams (RIBs). In two separate projects at the 88-Inch Cyclotron at LBNL - BEARS and the Recyclotron - we have developed techniques to efficiently ionize and accelerate beams of gaseous species of 11C (t1/2 = 20 min), 14,15O (t1/2 = 70 sec, 2 min) and 76,79Kr (t1/2 = 14,35 hours). Measurements of the ionization efficiency and hold-up times are discussed, along with issues of source contamination and poisoning encountered in running both RIBs and high-intensity stable beam experiments using the same ion source, the LBNL AECR-U. Methods used to tune clean RIBs through the Cyclotron with high efficiency are also discussed, including the use and limitations of analog beams.

McMahan, M.A.; Leitner, D.; Powell, J.; Silver, C. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2005-03-15

454

Study on the Low Frequency Plasma Oscillations in Cyclotron Multicharged Ion Source.  

National Technical Information Service (NTIS)

The low frequency plasma oscillations in a cyclotron ion source with indirect heating cathode are studied to find out the connection of these oscillations with the multicharged ion yield. The ion charge state distribution and frequency spectrum of a plasm...

A. S. Pasyuk S. L. Bogomolov V. B. Kutner

1980-01-01