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Sample records for chalk river cyclotron

  1. Initial field measurements on the Chalk River superconducting cyclotron

    Ormrod, J.H.; Chan, K.C.; Hill, J.H.

    1980-12-01

    The midplane magnetic field of the Chalk River superconducting cyclotron has been mapped in detail over the full operating range of 2.5 to 5 tesla. The field measuring apparatus is described and results given include measurements of the field stability, reproducibility and harmonic content. (author)

  2. Status of the Chalk River superconducting heavy-ion cyclotron

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

    1982-01-01

    The Chalk River four-sector K=520 superconducting cyclotron is designed to accelerate all ions from lithium (to 50 MeV/u) to uranium (to 10 MeV/u) using a 13 MV tandem Van de Graaff as injector. After an extended shutdown the magnet has been reassembled and field measurements resumed. During the shutdown a ground fault between the superconducting coil and its container was removed, the flutter poles were shimmed and the remaining trim rod holes were bored in them, the 104 trim rods with their holders were installed and the cryostat inner wall was modified to accept the radiofrequency accelerating structure. Experiments on the radiofrequency accelerating system, cryopumps, electrostatic deflector and superconducting windings for the magnetic channel are done in separate test chambers. Recent results and the status of all subsystems are given

  3. Foil changer for the Chalk River superconducting cyclotron

    Hoffmann, C.R.; Kilborn, R.I.; Mouris, J.E.; Proulx, D.R.; Weaver, J.F.

    1985-01-01

    Capture of an injected beam in the Chalk River superconducting cyclotron requires that a carbon stripping foil be accurately placed in a dee to intercept the incoming beam. Foil radial position must be precisely adjustable and foils must be easily replaced. A foil changing apparatus has been designed, built and tested to meet these requirements. The main components are a supply magazine, a transport system, and unloading and loading mechanisms. The magazine is on top of the cyclotron. It holds 300 foils and can be isolated from machine vacuum for refilling. Each foil is mounted on a stainless steel frame. A stainless steel roller chain fitted with 33 copper sleeves (shrouds) carries foils, one per shroud, down a dee stem to the midplane. A 12-bit absolute optical shaft encoder senses foil position. To replace a foil a shroud is positioned at the top of the cyclotron, a foil is removed, and another is transferred from the magazine to the empty shroud. Three stepping motors and associated electronics provide mechanical drive and are interfaced with a CAMAC control system

  4. Foil changer for the Chalk River superconducting cyclotron

    Hoffmann, C.R.; Kilborn, R.I.; Mouris, J.F.; Proulx, D.R.; Weaver, J.F.

    1985-01-01

    Capture of an injected beam in the Chalk River superconducting cyclotron requires that a carbon stripping foil be accurately placed in a dee to intercept the incoming beam. Foil radial position must be precisely adjustable and foils must be easily replaced. A foil changing apparatus has been designed, built and tested to meet these requirements. The main components are a supply magazine, a transport system, and unloading and loading mechanisms. The magazine is on top of the loading mechanisms. The magazine is on top of the cyclotron. It holds 300 foils and can be isolated from machine vacuum for refilling. Each foil is mounted on a stainless steel frame. A stainless steel roller chain fitted with 33 copper sleeves (shrouds) carries foils, one per shroud, down a dee stem to the midplane. A 12-bit absolute optical shaft encoder senses foil position. To replace a foil a shroud is positioned at the top of the cyclotron, a foil is removed, and another is transferred from the magazine to the empty shroud. Three stepping motors and associated electronics provide mechanical drive and are interfaced with a CAMAC control system

  5. Electrostatic deflector development at the Chalk River superconducting cyclotron

    Diamond, W.T.; Mitchel, G.R.; Almeida, J.; Schmeing, H.

    1991-01-01

    An electrostatic deflector is used to extract heavy-ion beans from the Chalk River superconducting cyclotron. Deflector voltages up to 100 kV across a 7 m gap (143 kV/cm) are needed to extract the full range of beams that the cyclotron is designed to accelerate. This goal remains a challenge, but substantial progress has been made over the past year. Voltages over 90 kV have been reliably maintained over a 7.5 mm gap with a magnetic field of 3 T. Voltages of 74 kV have been used with a reduced gap of 4.75 mm (corresponding to a field greater than 150 kV/cm) to extract beams with magnetic fields up to 4.25 T. Major progress was achieved when the authors introduced a water-cooled, negative high-voltage electrode, and changed the sparking plates and the thin septum from molybdenum to stainless steel. Efforts are continuing to attain a field of at least 143 kV/cm over a gap of at least 6 mm width

  6. Magnetic field related mechanical tolerances for the proposed Chalk River superconducting heavy-ion cyclotron

    Heighway, E.A.; Chaplin, K.R.

    1977-11-01

    A four sector azimuthally varying field cyclotron with superconducting main coils has been proposed as a heavy-ion post-accelerator for the Chalk River MP Tandem van de Graaff. The radial profile of the average axial field will be variable using movable steel trim rods. The field errors due to coil, trim rod and flutter pole imperfections are calculated. Those considered are errors in the axial field, first and second azimuthal harmonic axial fields, transverse field and first azimuthal harmonic transverse field. Such fields induce phase slip, axial or radial coherent oscillations and can result in axial or radial beam instability. The allowed imperfections (tolerances) required to retain stability and maintain acceptably small coherent oscillation amplitudes are calculated. (author)

  7. Reactor loops at Chalk River

    Sochaski, R.O.

    1962-07-01

    This report describes broadly the nine in-reactor loops, and their components, located in and around the NRX and NRU reactors at Chalk River. First an introduction and general description is given of the loops and their function, supplemented with a table outlining some loop specifications and nine simplified flow sheets, one for each individual loop. The report then proceeds to classify each loop into two categories, the 'main loop circuit' and the 'auxiliary circuit', and descriptions are given of each circuit's components in turn. These components, in part, are comprised of the main loop pumps, the test section, loop heaters, loop coolers, delayed-neutron monitors, surge tank, Dowtherm coolers, loop piping. Here again photographs, drawings and tables are included to provide a clearer understanding of the descriptive literature and to include, in tables, some specifications of the more important components in each loop. (author)

  8. The fusion blanket program at Chalk River

    Hastings, I.J.

    1986-03-01

    Work on the Fusion Blanket Program commenced at Chalk River in 1984 June. Co-funded by Canadian Fusion Fuels Technology Project and Atomic Energy of Canada Limited, the Program utilizes Chalk River expertise in instrumented irradiation testing, ceramics, tritium technology, materials testing and compound chemistry. This paper gives highlights of studies to date on lithium-based ceramics, leading contenders for the fusion blanket

  9. Measurements with the Chalk River Calorimeters

    Boyd, A.W.

    1970-01-01

    The Chalk River calorimeters were designed to measure the absorbed dose rate in reactors in materials such as graphite, polyethylene and beryllium in the range 0.01-1 Wg -1 . To eliminate heaters in the sample they were made to operate adiabatically, or more accurately quasi-adiabatically since there is no heater on the jacket. Both the sample and jacket temperatures are recorded from the time of insertion in the reactor flux and the absorbed dose rate is calculated from these data. The advantages of this type of calorimeter are the ease of construction and the absence of a sample heater. The disadvantage is that dose rates below ~ 10 mWg -1 cannot be determined accurately

  10. Radar sounding of bedrock and water table at Chalk River

    Annan, A.P.; Davis, J.L.

    1979-01-01

    When a spill of radioactive waste occurs, one of the main concerns is the flow pattern of ground water in the area of the spill. Ground probing radar is a relatively new geophysical technique which can provide high resolution data on the surficial geology and water distribution. The results of some preliminary radar experiments conducted at Chalk River Nuclear Laboratories (CRNL) of the Atomic Energy of Canada Limited (AECL), Chalk River, Ontario are presented. (auth)

  11. The Chalk River Tritium Extraction Plant

    Holtslander, W.J.; Harrison, T.E.; Spagnolo, D.A.

    1990-01-01

    The Chalk River Tritium Extraction Plant for removal of tritium from heavy water is described. Tritium is present in the heavy water from research reactors in the form of DTO at a concentration in the range of 1-35 Ci/kg. It is removed by a combination of catalytic exchange to transfer the tritium from DTO to DT, followed by cryogenic distillation to separate and concentrate the tritium to T 2 . The tritium product is reacted with titanium and packaged for transportation and storage as titanium tritide. The plant processes heavy water at a rate of 25 kg/h and removes 80% of the tritium and 90% of the protium per pass. Catalytic exchange is carried out in the liquid phase using a proprietary wetproofed catalyst. The plant serves two roles in the Canadian fusion program: it produces pure tritium for use in fusion research and development, and it demonstrates on an industrial scale many of the tritium technologies that are common to the tritium systems in fusion reactors (author)

  12. The Chalk River Tritium Extraction Plant

    Holtslander, W J; Harrison, T E; Spagnolo, D A

    1990-07-01

    The Chalk River Tritium Extraction Plant for removal of tritium from heavy water is described. Tritium is present in the heavy water from research reactors in the form of DTO at a concentration in the range of 1-35 Ci/kg. It is removed by a combination of catalytic exchange to transfer the tritium from DTO to DT, followed by cryogenic distillation to separate and concentrate the tritium to T{sub 2}. The tritium product is reacted with titanium and packaged for transportation and storage as titanium tritide. The plant processes heavy water at a rate of 25 kg/h and removes 80% of the tritium and 90% of the protium per pass. Catalytic exchange is carried out in the liquid phase using a proprietary wetproofed catalyst. The plant serves two roles in the Canadian fusion program: it produces pure tritium for use in fusion research and development, and it demonstrates on an industrial scale many of the tritium technologies that are common to the tritium systems in fusion reactors (author)

  13. Province of Ontario nuclear emergency plan part V - Chalk River

    NONE

    1991-10-01

    The aim of Part 5 of the Provincial Nuclear Emergency Plan is to describe the measures that shall be undertaken to deal with a nuclear emergency caused by the Chalk River Laboratories. This plan deals mainly with actions at the Provincial level and shall by supplemented by the appropriate Municipal Plan. The Townships of Rolph, Buchanan, Wylie, and McKay, the Town of Deep River and the Village of Chalk River are the designated municipalities with respect to CRL. 2 tabs., 5 figs.

  14. Province of Ontario nuclear emergency plan part V - Chalk River

    1991-10-01

    The aim of Part 5 of the Provincial Nuclear Emergency Plan is to describe the measures that shall be undertaken to deal with a nuclear emergency caused by the Chalk River Laboratories. This plan deals mainly with actions at the Provincial level and shall by supplemented by the appropriate Municipal Plan. The Townships of Rolph, Buchanan, Wylie, and McKay, the Town of Deep River and the Village of Chalk River are the designated municipalities with respect to CRL. 2 tabs., 5 figs

  15. Integrated waste plan for Chalk River Laboratories

    McClelland, P.; Bainbridge, I.

    2011-01-01

    The core missions for Chalk River Laboratories (CRL) will involve a complex suite of activities for decades to come, many of these activities resulting in production of some amount of wastes. In order to support the business of the Nuclear Laboratories there is a requirement to responsibly manage the wastes arising from these activities. Capability to develop waste stream pathway scenarios and be able to make informed strategic decisions regarding the various options for waste processing, storage and long-term management (i.e. e nabling facilities ) is necessary to discharge this responsibility in the most cost effective and sustainable manner. A holistic waste management plan integrated with the decommissioning, environmental remediation and operations programs is the desired result such that: - Waste inputs and timings are identified; - Timing of key decisions regarding enabling facilities is clearly identified; and - A defensible decision-making framework for enabling facilities is established, thereby ensuring value for Canadians. The quantities of wastes that require managing as part of the Nuclear Legacy Liabilities Program and AECL operations activities is in the range of 200,000 to 300,000 m 3 , with a yearly increase of several thousand m 3 . This volume can be classified into over thirty distinct waste streams having differing life cycle waste management pathways from generation to disposition. The time phasing of the waste management activities required for these wastes spans several decades and involves a complex array of processes and facilities. Several factors typical of wastes from the development of nuclear technology further complicate the situation. For example, there is considerable variation in the level of detail and format of waste records generated over several decades. Also, wastes were put into storage over several decades without knowledge or consideration of what the final disposition path will be. Prior to proceeding with any major new

  16. Reactor safety research and development in Chalk River Laboratories

    Nitheanandan, T. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2014-07-01

    Atomic Energy of Canada Limited's Chalk River Laboratories provides three different services to stakeholders and customers. The first service provided by the laboratory is the implementation of Research and Development (R&D) programs to provide the underlying technological basis of safe nuclear power reactor designs. A significant portion of the Canadian R&D capability in reactor safety resides at Atomic Energy of Canada Limited's Chalk River Laboratories, and this capability was instrumental in providing the science and technology required to aid in the safety design of CANDU power reactors. The second role of the laboratory has been in supporting nuclear facility licensees to ensure the continued safe operation of nuclear facilities, and to develop safety cases to justify continued operation. The licensing of plant life extension is a key industry objective, requiring extensive research on degradation mechanisms, such that safety cases are based on the original safety design data and valid and realistic assumptions regarding the effect of ageing and management of plant life. Recently, Chalk River Laboratories has been engaged in a third role in research to provide the technical basis and improved understanding for decision making by regulatory bodies. The state-of-the-art test facilities in Chalk River Laboratories have been contributing to the R&D needs of all three roles, not only in Canada but also in the international community, thorough Canada's participation in cooperative programs lead by International Atomic Energy Agency and the OECD's Nuclear Energy Agency. (author)

  17. Cancer and workers' compensation at Chalk River nuclear laboratories

    Evans, D.W.S.

    1985-01-01

    This paper describes the circumstances leading to the notification to the Worker's Compensation Board of Ontario of two cases of cancer, both involving the lymphatic and haematoporetic systems, in employees at Chalk River Nulcear Laboratories. Twenty of these neoplasms are known to have occurred in the CRNL population between 1966 and 1983. The leukemia/lymphoma ratio observed in the twenty neoplasms is similar to that found in populations not occupationally exposed to ionizing radiation. The possible relationship between asbestos exposure and lymphoid neoplasms was discussed. 5 refs

  18. The dynamic analysis facility at the Chalk River Nuclear Laboratories

    Argue, D.S.; Howatt, W.T.

    1979-10-01

    The Dynamic Analysis Facility at the Chalk River Nuclear Laboratories (CRNL) of Atomic Energy of Canada Limited (AECL) comprises a Hybrid Computer, consisting of two Applied Dynamic International AD/FIVE analog computers and a Digital Equipment Corporation (DEC) PDP-11/55 digital computer, and a Program Development System based on a DEC PDP-11/45 digital computer. This report describes the functions of the various hardware components of the Dynamic Analysis Facility and the interactions between them. A brief description of the software available to the user is also given. (auth)

  19. Mortality among long-term Chalk River employees

    Werner, M.M.; Myers, D.K.

    1986-12-01

    Mortality among Chalk River Nuclear Laboratory (CRNL) employees who died during employment or after retirement has been updated to 1985 December 31. Data in tabular form are presented for overall mortality for male and female employees, for the participants in the clean-up for the NRX and NRU reactor accidents and for a group of CRNL staff with lifetime accumulative doses in excess of 0.2 Sv. Data are also presented on the different types of cancer causing death among male employees. No statistically significant increases in cancer deaths were found in any of the groups analyzed. 25 refs

  20. Field studies of radionuclide transport at the Chalk River Laboratories

    Champ, D.R.; Killey, R.W.D.; Moltyaner, G.L.

    1991-01-01

    In this paper the authors summarize the results of: in situ field column experiments to study the transport behaviour of several long-lived radionuclides, 4 natural gradient non-reactive radiotracer injection experiments at the Chalk River Laboratories (CRL) Twin Lake Tracer Test Site, and a model validation study that used data for 90 Sr from two well-defined contaminated groundwater flow systems at CRL. The paper also describes a current re-evaluation of radionuclide release and transport from a 1960 experimental burial (in a CRL sand aquifer) of glass blocks containing fission and activation products. (J.P.N.)

  1. Superconducting cyclotrons

    Blosser, H.G.; Johnson, D.A.; Burleigh, R.J.

    1976-01-01

    Superconducting cyclotrons are particularly appropriate for acceleration of heavy ions. A review is given of design features of a superconducting cyclotron with energy 440 (Q 2 /A) MeV. A strong magnetic field (4.6 tesla average) leads to small physical size (extraction radius 65 cm) and low construction costs. Operating costs are also low. The design is based on established technology (from present cyclotrons and from large bubble chambers). Two laboratories (in Chalk River, Canada and in East Lansing, Michigan) are proceeding with construction of full-scale prototype components for such cyclotrons

  2. Atmospherically dispersed radiocarbon at the Chalk River Laboratories

    Milton, G.M.; Brown, R.M.; Repta, C.J.W.; Selkirk, C.J.

    1996-01-01

    A small percentage of the total radiocarbon produced by the NRX and NRU experimental reactors at the Chalk River Laboratories has been vented from the main reactor stack and atmospherically dispersed across the site. Surveys conducted in 1982-83 and 1993-94 have shown that atmospheric levels more than 50 m from the stack are never greater than 600 Bq.kg -1 carbon above the natural background level, falling to near-global atmospheric levels at the site boundaries roughly 7 km away. A dispersion factor > 1.2 x 10 6 m 3 .s -1 at ∼ 0.75 km distance from the point of emission is calculated on the basis of recent in-stack monitoring. Analysis of growth rings in on-site trees has provided an opportunity to search for correlations of 14 C output summer power production and/or moderator losses. (author). 16 refs., 14 tabs., 11 figs

  3. Trial coring in LLRW trenches at Chalk River

    Donders, R.E.; Killey, R.W.D.; Franklin, K.J.; Strobel, G.S.

    1996-11-01

    As part of a program to better characterize the low-hazard radioactive waste managed by AECL at Chalk River Laboratories, coring techniques in waste trenches are being assessed. Trial coring has demonstrated that sampling in waste regions is possible, and that boreholes can be placed through the waste trenches. Such coring provides a valuable information-gathering technique. Information available from trench coring includes: trench cover depth, waste region depth, waste compaction level, and detailed stratigraphic data; soil moisture content and facility drainage performance; borehole gamma logs that indicate radiation levels in the region of the borehole; biochemical conditions in the waste regions, vadose zone, and groundwater; site specific information relevant to contaminant migration modelling or remedial actions; information on contaminant releases and inventories. Boreholes through the trenches can also provide a means for early detection of potential contaminant releases. (author). 4 refs., 4 tabs., 4 figs

  4. Radiocarbon dating with the Chalk River MP Tandem accelerator

    Ball, G.C.; Andrews, H.R.; Brown, R.M.; Burn, N.; Davies, W.G.; Imahori, Y.; Milton, J.C.D.

    1981-01-01

    During the past three years an automated radiocarbon dating system based on the MP Tandem accelerator has been developed for the analysis of 14 C in groundwater samples from the nuclear waste disposal research program and other small samples of scientific interest. At the present time 14 C/ 12 C ratio measurements can be determined with an accuracy of about 5% and the system background levels (approx. 35000 to 45000 years) are totally determined by sample and/or ion source contamination. Our goal has been to develop a dedicated reliable system for routine analysis that will produce accurate results with a minimum expenditure of human resources and accelerator beam time. Improvements required to operate the tandem accelerator as a quantitative tool have also benefited the rest of the experimental nuclear physics program. The early evolution of the dating facility was described previously. This paper is a brief report of the current status at Chalk River

  5. Isotope hydrology of the Chalk River Laboratories site, Ontario, Canada

    Peterman, Zell; Neymark, Leonid; King-Sharp, K.J.; Gascoyne, Mel

    2016-01-01

    This paper presents results of hydrochemical and isotopic analyses of groundwater (fracture water) and porewater, and physical property and water content measurements of bedrock core at the Chalk River Laboratories (CRL) site in Ontario. Density and water contents were determined and water-loss porosity values were calculated for core samples. Average and standard deviations of density and water-loss porosity of 50 core samples from four boreholes are 2.73 ± 12 g/cc and 1.32 ± 1.24 percent. Respective median values are 2.68 and 0.83 indicating a positive skewness in the distributions. Groundwater samples from four deep boreholes were analyzed for strontium (87Sr/86Sr) and uranium (234U/238U) isotope ratios. Oxygen and hydrogen isotope analyses and selected solute concentrations determined by CRL are included for comparison. Groundwater from borehole CRG-1 in a zone between approximately +60 and −240 m elevation is relatively depleted in δ18O and δ2H perhaps reflecting a slug of water recharged during colder climatic conditions. Porewater was extracted from core samples by centrifugation and analyzed for major dissolved ions and for strontium and uranium isotopes. On average, the extracted water contains 15 times larger concentration of solutes than the groundwater. 234U/238U and correlation of 87Sr/86Sr with Rb/Sr values indicate that the porewater may be substantially older than the groundwater. Results of this study show that the Precambrian gneisses at Chalk River are similar in physical properties and hydrochemical aspects to crystalline rocks being considered for the construction of nuclear waste repositories in other regions.

  6. Effluent and environmental monitoring of Chalk River Laboratories

    Pilgrim, T.; De Waele, C.; Gallagher, C. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2014-07-01

    Atomic Energy of Canada Limited's (AECL's) Environmental Protection Program has been gathering environmental monitoring data at its Chalk River Laboratories (CRL) for over 60 years. The comprehensive effluent and environmental monitoring program at CRL consists of more than 600 sampling locations, including the Ottawa River, with approximately 60,000 analyses performed on air and liquid effluent parameters each year. Monitoring for a variety of radiological and non-radiological parameters is regularly conducted on various media, including ambient air, foodstuff (e.g. milk, fish, garden produce, large game, and farm animals), groundwater, Ottawa River water and other surface water on and off-site. The purpose of the monitoring program is to verify that past and current radiological and non-radiological emissions derived from AECL operations and activities, such as process water effluent into the Ottawa River, are below regulatory limits and demonstrate that CRL operations do not negatively affect the quality of water on or leaving the site. In fact, ongoing program reports demonstrate that radiological emissions are well below regulatory limits and have been declining for the past five years, and that non-radiological contaminants do not negatively affect the quality of water on and off the site. Two updated Canadian Standards Association (CSA) standards for Effluent and Environmental monitoring have come into effect and have resulted in some changes to the AECL Program. This presentation will discuss effluent and surface water monitoring results, the observed trends, the changes triggered by the CSA standards, and a path forward for the future. (author)

  7. Experience with radioactive waste incineration at Chalk River Nuclear Laboratories

    Le, V.T.; Beamer, N.V.; Buckley, L.P.

    1988-06-01

    Chalk River Nuclear Laboratories is a nuclear research centre operated by Atomic Energy of Canada Limited. A full-scale waste treatment centre has been constructed to process low- and intermediate-level radioactive wastes generated on-site. A batch-loaded, two-stage, starved-air incinerator for solid combustible waste is one of the processes installed in this facility. The incinerator has been operating since 1982. It has consistently reduced combustible wastes to an inert ash product, with an average volume reduction factor of about 150:1. The incinerator ash is stored in 200 L drums awaiting solidification in bitumen. The incinerator and a 50-ton hydraulic baler have provided treatment for a combined volume of about 1300 m 3 /a of solid low-level radioactive waste. This paper presents a review of the performance of the incinerator during its six years of operation. In addition to presenting operational experience, an assessment of the starved-air incineration technique will also be discussed

  8. The Chalk River helium jet and skimmer system

    Schmeing, H.; Koslowsky, V.; Wightman, M.; Hardy, J.C.; MacDonald, J.A.; Faestermann, T.; Andrews, H.R.; Geiger, J.S.; Graham, R.L.

    1976-01-01

    A helium jet and skimmer system intended as an interface between a target location at the Chalk River tandem accelerator and the ion source of an on-line separator presently under construction has been developed. The system consists of a target chamber, a 125 cm long capillary, and a one stage skimmer chamber. The designs of the target and skimmer chambers allow one to vary a large number of independent flow and geometrical parameters with accurate reproducibility. Experiments with the β-delayed proton emitter 25 Si (tsub(1/2)=218 ms) produced in the reaction 24 Mg( 3 He,2n) 25 Si show that under optimized conditions about 75% of the reaction products leaving the target are transported to the skimmer. Of those, more than 90% pass through the skimmer orifice, which separates off 97.5% of the transport gas, helium. By introducing an additional helium flow across the skimming orifice the amount of helium separated off the transport jet can be increased to beyond 99.85%, leaving the high throughput of recoils unaffected. (Auth.)

  9. Contaminated groundwater characterization at the Chalk River Laboratories, Ontario, Canada

    Schilk, A.J.; Robertson, D.E.; Thomas, C.W.; Lepel, E.A. [Pacific Northwest National Lab., Richland, WA (United States); Champ, D.R.; Killey, R.W.D.; Young, J.L.; Cooper, E.L. [Chalk River Labs., Chalk River, Ontario (Canada)

    1993-03-01

    The licensing requirements for the disposal of low-level radioactive waste (10 CFR 61) specify the performance objectives and technical requisites for federal and commercial land disposal facilities, the ultimate goal of which is to contain the buried wastes so that the general population is adequately protected from harmful exposure to any released radioactive materials. A major concern in the operation of existing and projected waste disposal sites is subterranean radionuclide transport by saturated or unsaturated flow, which could lead to the contamination of groundwater systems as well as uptake by the surrounding biosphere, thereby directly exposing the general public to such materials. Radionuclide transport in groundwater has been observed at numerous commercial and federal waste disposal sites [including several locations within the waste management area of Chalk River Laboratories (CRL)], yet the physico-chemical processes that lead to such migration are still not completely understood. In an attempt to assist in the characterization of these processes, an intensive study was initiated at CRL to identify and quantify the mobile radionuclide species originating from three separate disposal sites: (a) the Chemical Pit, which has received aqueous wastes containing various radioisotopes, acids, alkalis, complexing agents and salts since 1956, (b) the Reactor Pit, which has received low-level aqueous wastes from a reactor rod storage bay since 1956, and (c) the Waste Management Area C, a thirty-year-old series of trenches that contains contaminated solid wastes from CRL and various regional medical facilities. Water samples were drawn downgradient from each of the above sites and passed through a series of filters and ion-exchange resins to retain any particulate and dissolved or colloidal radionuclide species, which were subsequently identified and quantified via radiochemical separations and gamma spectroscopy. These groundwaters were also analyzed for anions

  10. WIMS-CRNL: A user's manual for the Chalk River version of WIMS

    Donnelly, J.V.

    1986-01-01

    This report describes the preparation of the input for WIMS-CRNL, the Chalk River version of the WIMS lattice code. Also included are notes on the operation of the code, contents of the associated libraries, and the relation of WIMS-CRNL to other versions of the code

  11. ACE - an algebraic compiler and encoder for the Chalk River datatron computer

    Kennedy, J.M.; Okazaki, E.A.; Millican, M.

    1960-03-01

    ACE is a program written for the Chalk River Datatron (Burroughs 205) Computer to enable the machine to compile a program for solving a problem from instructions supplied by the user in a notation related much more closely to algebra than to the machine's own code. (author)

  12. Heating- and growing-degree days at Chalk River Nuclear Laboratories, 1976-1980

    Jay, P.C.; Wildsmith, D.P.

    1981-05-01

    An update of the report, Heating- and Growing-Degree-Days at Chalk River Nuclear Laboratories (AECL-5547) is presented along with various other meteorological variables which were not included in the previous publication. Also included, and shown in graph form, are the monthly degree-day frequencies. (author)

  13. Vertical distribution of radioactive particles in Ottawa River sediment near the Chalk River Laboratories

    Lee, D.R.; Hartwig, D.S.

    2011-01-01

    Previously, we described an area of above-background levels of radioactivity in the bed of the Ottawa River near the Chalk River Laboratories. The area was about 200 m wide by 400 m long and in water 8 to 30 m deep. The source of the radioactivity was associated with the location of cooling-water discharge. Particles of radioactive material were later recovered from the upper 10-15 cm of sediment and were determined to be sand-sized grains of nuclear fuel and corrosion products. This report provides an examination of the vertical distribution of radioactive particles in the riverbed. Twenty-three dredge samples (representing 1.2 m 2 of riverbed) were collected near the Process Outfall. Each dredge sample was dissected in horizontal intervals 1-cm-thick. Each interval provided a 524 cm 3 sample of sediment that was carefully examined for particulate radioactivity. Approximately 80% of the radioactivity appeared to be associated with discrete particles. Although the natural sediment in the general area is cohesive, silty clay and contains less than 10% sand, the sediment near the Outfall was found to be rich in natural sand, presumably from sources such as winter sanding of roads at the laboratories. The radioactive particles were almost entirely contained in the top-most 10 cm of the river bed. The majority of the particles were found several centimetres beneath the sediment surface and the numbers of particles and the radioactivity of the particles peaked 3 to 7 cm below the sediment surface. Based on the sediment profile, there appeared to have been a marked decrease in the deposition of particulate radioactivity in recent decades. The vertical distribution of radioactive particles indicated that sedimentation is resulting in burial and that the deposition of most of the particulate radioactivity coincided with the operation of Chalk River's NRX reactor from 1947 to 1992. (author)

  14. Likely-clean concrete disposition at Chalk River Laboratories

    Betts, J.A. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2011-07-01

    The vast majority of wastes produced at nuclear licensed sites are no different from wastes produced from other traditional industrial activities. Radiation and contamination control practices ensure that the small amounts of waste materials that contain a radiation and or contamination hazard are segregated and managed appropriately according to the level of hazard. Part of the segregation process involves additional clearance checks of wastes generated in areas where the potential to become radioactively contaminated exists, but is very small and contamination control practices are such that the wastes are believed to be 'likely-clean'. This important clearance step helps to ensure that radioactive contamination is not inadvertently released during disposition of inactive waste materials. Clearance methods for bagged likely-clean wastes (i.e. small volumes of low density wastes) or discreet non-bagged items are well advanced. Clearance of bagged likely-clean wastes involves measuring small volumes of bagged material within purpose built highly sensitive bag monitors. For non-bagged items the outer surfaces are scanned to check for surface contamination using traditional hand-held contamination instrumentation. For certain very bulky and porous materials (such as waste concrete), these traditional clearance methods are impractical or not fully effective. As a somewhat porous (and dense) material, surface scanning cannot always be demonstrated to be conclusive. In order to effectively disposition likely-clean concrete, both the method of clearance (i.e. conversion from likely-clean to clean) and method of disposition have to be considered. Likely-clean concrete wastes have been produced at Chalk River Laboratories (CRL) from demolitions of buildings and structures, as well as small amounts from site maintenance activities. A final disposition method for this material that includes the secondary clearance check that changes the classification of this

  15. Likely-clean concrete disposition at Chalk River Laboratories

    Betts, J.A.

    2011-01-01

    The vast majority of wastes produced at nuclear licensed sites are no different from wastes produced from other traditional industrial activities. Radiation and contamination control practices ensure that the small amounts of waste materials that contain a radiation and or contamination hazard are segregated and managed appropriately according to the level of hazard. Part of the segregation process involves additional clearance checks of wastes generated in areas where the potential to become radioactively contaminated exists, but is very small and contamination control practices are such that the wastes are believed to be 'likely-clean'. This important clearance step helps to ensure that radioactive contamination is not inadvertently released during disposition of inactive waste materials. Clearance methods for bagged likely-clean wastes (i.e. small volumes of low density wastes) or discreet non-bagged items are well advanced. Clearance of bagged likely-clean wastes involves measuring small volumes of bagged material within purpose built highly sensitive bag monitors. For non-bagged items the outer surfaces are scanned to check for surface contamination using traditional hand-held contamination instrumentation. For certain very bulky and porous materials (such as waste concrete), these traditional clearance methods are impractical or not fully effective. As a somewhat porous (and dense) material, surface scanning cannot always be demonstrated to be conclusive. In order to effectively disposition likely-clean concrete, both the method of clearance (i.e. conversion from likely-clean to clean) and method of disposition have to be considered. Likely-clean concrete wastes have been produced at Chalk River Laboratories (CRL) from demolitions of buildings and structures, as well as small amounts from site maintenance activities. A final disposition method for this material that includes the secondary clearance check that changes the classification of this

  16. Edibility of sport fishes in the Ottawa River near Chalk River Laboratories

    Lee, D.R.; Chaput, T.; Miller, A.; Wills, C.A., E-mail: leed@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    To address the question of edibility of fish in the Ottawa River near Chalk River Laboratories (CRL), 123 game fish were collected for analysis from four locations: Mackey and Rolphton (45 km and 35 km upstream of Chalk River Laboratories (CRL), respectively), the Sandspit (Pointe au Bapteme) and Cotnam Island (1.6 km and 45 km downstream of CRL, respectively). Twenty-six to thirty-six game fish were collected at each location in 2007 and samples of flesh or bone were analyzed. Trap nets were used to collect only the fish required, allowing release of management-sensitive species. The focus was on walleye (Sander vitreus) because they are abundant and popular among anglers. A few northern pike (Esox lucius) and a smaller number of smallmouth bass (Micropterus dolomieui) were also collected at three of the four sites. Samples of the fish were analyzed for cesium-137 ({sup 137}Cs), strontium-90 ({sup 90}Sr), mercury (Hg), and selected organo-chlorine compounds. Concentrations of {sup 137}Cs in the flesh and {sup 90}Sr in the bones of sport fish were low and similar at all four locations and appear to reflect the global residuals from nuclear weapons testing (primarily in the 1960's) as opposed to releases from CRL. Possible explanations are: 1) Reductions in radionuclide releases from CRL in recent decades and 2) Relatively large foraging ranges of sport fish. Mercury concentrations were elevated in fishes in the Ottawa River and were significantly higher at the Sandspit and Rolphton than at Mackey and Cotnam Island (p<0.001). Mercury concentrations from the four sites are comparable to concentrations in other Ontario and Quebec lakes. It is advisable therefore, that consumers follow the fish consumption guidelines issued by provincial authorities when eating fish from the Ottawa River. Organo-chlorine compounds were not detected in walleye; however, they were detected in all eight of the pike collected at Cotnam Island. The highest organo

  17. Edibility of sport fishes in the Ottawa River near Chalk River Laboratories

    Lee, D.R.; Chaput, T.; Miller, A.; Wills, C.A.

    2013-01-01

    To address the question of edibility of fish in the Ottawa River near Chalk River Laboratories (CRL), 123 game fish were collected for analysis from four locations: Mackey and Rolphton (45 km and 35 km upstream of Chalk River Laboratories (CRL), respectively), the Sandspit (Pointe au Bapteme) and Cotnam Island (1.6 km and 45 km downstream of CRL, respectively). Twenty-six to thirty-six game fish were collected at each location in 2007 and samples of flesh or bone were analyzed. Trap nets were used to collect only the fish required, allowing release of management-sensitive species. The focus was on walleye (Sander vitreus) because they are abundant and popular among anglers. A few northern pike (Esox lucius) and a smaller number of smallmouth bass (Micropterus dolomieui) were also collected at three of the four sites. Samples of the fish were analyzed for cesium-137 ( 137 Cs), strontium-90 ( 90 Sr), mercury (Hg), and selected organo-chlorine compounds. Concentrations of 137 Cs in the flesh and 90 Sr in the bones of sport fish were low and similar at all four locations and appear to reflect the global residuals from nuclear weapons testing (primarily in the 1960's) as opposed to releases from CRL. Possible explanations are: 1) Reductions in radionuclide releases from CRL in recent decades and 2) Relatively large foraging ranges of sport fish. Mercury concentrations were elevated in fishes in the Ottawa River and were significantly higher at the Sandspit and Rolphton than at Mackey and Cotnam Island (p<0.001). Mercury concentrations from the four sites are comparable to concentrations in other Ontario and Quebec lakes. It is advisable therefore, that consumers follow the fish consumption guidelines issued by provincial authorities when eating fish from the Ottawa River. Organo-chlorine compounds were not detected in walleye; however, they were detected in all eight of the pike collected at Cotnam Island. The highest organo-chlorine concentrations were measured in two

  18. The new Chalk River AMS ion source, sample changer and external sample magazine

    Koslowsky, V.T.; Bray, N.; Imahori, Y.; Andrews, H.R.; Davies, W.G.

    1997-01-01

    A new sample magazine, sample changer and ion source have been developed and are in routine use at Chalk River. The system features a readily accessible 40-sample magazine at ground potential that is external to the ion source and high-voltage cage. The samples are held in an inert atmosphere and can be individually examined or removed; they can be exchanged en masse as a complete magazine concurrent with an AMS measurement. On-line sample changing is done with a pneumatic rabbit transfer system employing two stages of differential pumping. At Chalk River this is routinely performed across a 200 kV potential. Sample positioning is precise, and hundreds of 36 Cl and 129 I samples have been measured over a period of several days without interruption or alteration of ion source operating conditions. (author)

  19. Regional transport of radioxenon released from the Chalk River Laboratories medical isotope facility

    Christine Johnson; Steven Biegalski

    2015-01-01

    An examination of proposed sampling sites near Chalk River Laboratories in Ontario, Canada is performed by considering the regional transport of radioxenon using atmospheric dispersion modeling. The local geography is considered, as are the local meteorological conditions during the summer months. In particular the impacts of predicted conditions on the imprinting of atmospheric radioxenon into the subsurface are considered and weighed against site proximity, geography, and geology. (author)

  20. Overview of research in physics and health sciences at the Chalk River Nuclear Laboratories

    Milton, J.C.D.

    1988-01-01

    Toxicology research was a logical extension of existing program at Chalk River. Research in radiotoxicology has been going on there since the early forties. An overview of the existing physics and health sciences research programs operating at the Research Company of Atomic Energy of Canada Limited was presented. Programs in nuclear physics, heavy ion nuclear physics, astrophysical neutrino physics, condensed matter physics, fusion, biology, dosimetry, and environmental sciences were briefly described. In addition, a description of the research company organization was provided

  1. Analysis of the Pelletron charging chain break in the Chalk River MP tandem accelerator

    Burn, N.; Greiner, B.F.; Coleman, C.E.

    1980-11-01

    On February 7, 1980 one of the three Pelletron charging chains in the Low Energy end of the Chalk River MP Tandem Accelerator broke during normal operation. The chains had been in use for 38 000 h at the time of the break. Tensile tests were carried out on pieces of the broken chain as well as unused pieces of chain. Several possible reasons for the chain break are suggested; ways of improving performance and reliability are proposed. (auth)

  2. A review of geophysical investigations at the site of Chalk River Nuclear Laboratories, Ontario

    Thomas, M.D.; Hayles, J.G.

    1988-01-01

    The site of the Chalk River Nuclear Laboratories was one of the first research areas located on crystalline rocks to be extensively investigated under the Canadian Nuclear Fuel Waste Management Program. A large contribution to meeting the geoscientific objectives of the program has been made using a suite of geophysical techniques. Many of them are standard, though sometimes modified in terms of instrumentation and/or experimental and/or analytical procedures, to meet the particular needs of the waste management program. Relatively new techniques have also been employed. Much of the early evaluation and development of the various techniques took place at the Chalk River site. Standard methods such as gravity, magnetics and seismic sounding have been used to investigate bedrock structure, and the seismic method has also been used to estimate overburden thickness. Standard geophysical borehole logging has been used to obtain in situ estimates of physical properties, to locate fracture zones and to make hole to hole correlations that have helped define local structure. Several standard electrical (e.g. resitivity) and electromagnetic (e.g. VLF-EM) techniques have proven successful in identifying water-filled fractures and faults. Relatively new techniques introduced into the geophysics at Chalk River were: ground probing radar; to investigate overburden; borehole TV and acoustic televiewer and VLF-EM, to locate fractures; studies of seismic tube-waves, well tides and temperature logs, to investigate fracture location and permeability. Most of these methods have been successful and are now routinely employed at other research sites

  3. A summary of the Chalk River valve packing evaluation program 1985 - 1990

    Aikin, J.A.; Doubt, G.L.; Lade, C.R.

    1990-12-01

    The move away from asbestos-based valve packing products has generated concern among valve manufacturers, packing manufacturers and user groups about the reliability and safety of non-asbestos based products for long-term use. AECL Research, Chalk River, has been actively evaluating these new valve packing products since 1985. This report describes the work done at Chalk River from 1985 to 1990. The report includes both Electric Power Research Institute (EPRI) and CANDU Owners Group (COG) funded studies. A description of the test programs and a brief summary of the functional performance of the more successful materials (die-formed graphite, braided asbestos and braided non-asbestos) on friction, stem leakage and consolidation are provided. At this time, Chalk River and Ontario Hydro have approved the following packing arrangements: for non-live-loaded valves, the recommended replacements packing for braided asbestos is combination flexible graphite packing sets; and, for heavy water valves originally designed with JC187I, the recommended replacement packing is approved braided-asbestos products

  4. Response of invertebrates from the hyporheic zone of chalk rivers to eutrophication and land use.

    Pacioglu, Octavian; Moldovan, Oana Teodora

    2016-03-01

    Whereas the response of lotic benthic macroinvertebrates to different environmental stressors is a widespread practice nowadays in assessing the water and habitat quality, the use of hyporheic zone invertebrates is still in its infancy. In this study, classification and regression trees analysis were employed in order to assess the ecological requirements and the potential as bioindicators for the hyporheic zone invertebrates inhabiting four lowland chalk rivers (south England) with contrasting eutrophication levels (based on surface nitrate concentrations) and magnitude of land use (based on percentage of fine sediments load and median interstitial space). Samples of fauna, water and sediment were sampled twice, during low (summer) and high (winter) groundwater level, at depths of 20 and 35 cm. Certain groups of invertebrates (Glossosomatidae and Psychomyiidae caddisflies, and riffle beetles) proved to be good indicators of rural catchments, moderately eutrophic and with high fine sediment load. A diverse community dominated by microcrustaceans (copepods and ostracods) were found as good indicators of highly eutrophic urban streams, with moderate-high fine sediment load. However, the use of other taxonomic groups (e.g. chironomids, oligochaetes, nematodes, water mites and the amphipod Gammarus pulex), very widespread in the hyporheic zone of all sampled rivers, is of limited use because of their high tolerance to the analysed stressors. We recommend the use of certain taxonomic groups (comprising both meiofauna and macroinvertebrates) dwelling in the chalk hyporheic zone as indicators of eutrophication and colmation and, along with routine benthic sampling protocols, for a more comprehensive water and habitat quality assessment of chalk rivers.

  5. Field burial results and SIMS analysis of the Chalk River glass blocks

    Tait, J.C.; Hocking, W.H.; Betteridge, J.S.; Bart, G.

    1986-01-01

    In 1959, 25 2-kg hemispherical blocks of aluminosilicate glass, each containing ∼90 MBq/g of mixed fission products, were buried in a sandy soil aquifer in the waste management area at the Chalk River Nuclear Laboratories. A second set of blocks, containing ∼260 MBq/g mixed fission products, was buried in 1960. One block from each test was retrieved in 1978 to undergo chemical and surface analysis. This report reviews the migration of the 90 Sr and 137 Cs plume in the soil and presents the results of SIMS depth profiling of the surface of a glass block. (author)

  6. An overview of the waste characterization program at Chalk River Nuclear Laboratories

    Csullog, G.W.; Hardy, D.G.

    1990-05-01

    A comprehensive Waste Characterization Program (WCP) is in place at Chalk River Laboratories to support disposal projects. The WCP is responsible for: 1) specifying the manifests for waste shipments; 2) developing and maintaining central databases for waste inventories and analytical data; and 3) developing the technologies and procedures to characterize the radiological and the physical/chemical properties of wastes. WCP work is being performed under the umbrella of a newly developed waste management Quality Assurance (QA) program. This paper gives an overview of the WCP with an emphasis on the requirements for determining radionuclide inventories in wastes, for implementing record-keeping systems, and for maintaining a QA program for disposal operations

  7. Facilities for post-irradiation examination of experimental fuel elements at Chalk River Nuclear Laboratories

    Mizzan, E.; Chenier, R.J.

    1979-10-01

    Expansion of post-irradiation facilities at the Chalk River Nuclear Laboratories and steady improvement in hot-cell techniques and equipment are providing more support to Canada's reactor fuel development program. The hot-cell facility primarily used for examination of experimental fuels averages a quarterly throughput of 40 elements and 110 metallographic specimens. New developments in ultrasonic testing, metallographic sample preparation, active storage, active waste filtration, and fissile accountability are coming into use to increase the efficiency and safety of hot-cell operations. (author)

  8. Proceedings of a workshop on geophysical and related geoscientific research at Chalk River, Ontario

    Thomas, M.D.; Dixon, D.F.

    1989-10-01

    A large part of the Canadian Nuclear Fuel Waste Management Program is geoscience research and development aimed at obtaining information to quantify the transport of radionuclides through the geosphere and at determining the geotechnical properties required for disposal vault design. The geosphere at potential disposal sites is characterized in part by the use of remote sensing (geophysical) methods. In 1977 public concern about the disposal of radioactive waste resulted in field work being restricted to the site of Chalk River Nuclear Laboratories, which was used to develop, evaluate and compare various techniques in order to optimize the methods for obtaining geoscience information. Methods tested at Chalk River are to be applied at other research sites. Most investigations have been carried out around Maskinonge Lake, using about thirty boreholes sink into bedrock. The boreholes provide subsurface geological information that can be used as a reference to compare the responses of various geophysical methods and equipment. Regional studies, including airborne geophysical surveys, have also been conducted. The 25 papers presented at this workshop provide comprehensive documentation of the most significant results of geophysical studies. The workshop also provided an evaluation of geophysical techniques and their utility to the Nuclear Fuel Waste Management Program

  9. Programme of research into the management and storage of radioactive waste. Single fracture experiment at Chalk River

    Bourke, P.J.

    1984-01-01

    A field experiment was carried out at Chalk river to measure the transport of bromine and strontium through a fracture in granite. Retardation of strontium transport by sorption onto the rock was also measured. Data was obtained for bromine but no useful data was obtained for strontium due to failure of the hydraulic equipment. (U.K.)

  10. Drivers of abundance and community composition of benthic macroinvertebrates in Ottawa River sediment near Chalk River Laboratories

    Bond, M.J.; Rowan, D.; Silke, R.; Carr, J., E-mail: bondm@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2013-12-15

    The Ottawa River has received effluent from Chalk River Laboratories (CRL) for more than 60 years. Some radionuclides and contaminants released in effluents are bound rapidly to particles and deposited in bottom sediments where they may be biologically available to benthic invertebrates and other aquatic biota. As part of a larger ecological assessment, we assess the potential impact of contaminated sediments in the vicinity of CRL on local benthic community structure. Using bivariate and multivariate approaches, we demonstrate that CRL operations have had little impact on the local benthic community. Despite elevated anthropogenic radionuclide activity concentrations in sediment near CRL's process outfall, the benthic community is no less abundant or diverse than what is observed upstream at background levels. The Ottawa River benthic invertebrate community is structured predominantly by natural physical and biological conditions in the sediment, specifically sediment water content and organic content. These natural habitat conditions have a stronger influence on macroinvertebrate communities than sediment contamination. (author)

  11. Causes of death among long-term employees of Chalk River Laboratories, 1966-1989

    Werner, M.M.; Myers, D.K.

    1990-11-01

    Data on mortality among long-term employees of Chalk River Laboratories to 1989 December 31 are reported. The 1988 Hare report, entitled The Safety of Ontario's Nuclear Power Reactors, noted that there had been a steady rise in standardized mortality ratios (SMR) for cancer among these employees in the last three successive five-year periods from 1971-75 to 1981-85. None of the SMRs was significantly different from unity; however, the apparent trend could be indicative of the development of latent cancers. The present report was prepared to see if that increasing trend in cancer SMRs continued. In the years 1986-89, the SMR for cancer among long-term male employees was exceptionally low. The wide fluctuations seen in our data over time are likely anomalies arising from the small size of the study group rather than problems arising from radiation exposures on site

  12. Derived release limits (DRL's) for airborne and liquid effluents from the Chalk River Nuclear Laboratories during normal operations

    Palmer, J.F.

    1981-02-01

    Derived release limits (DRL's), based on regulatory dose limits, have been calculated for routine discharges of radioactivity in airborne and liquid effluents from the Chalk River Nuclear Laboratories. Three types of sources of airborne effluents were considered: the NRX/NRU stack, the 61 m stack connected to the 99 Mo production facility, and a roof vent typical of those installed on several buildings on the site. Sources of liquid effluents to the Ottawa River were treated as a single source from the site as a whole. Various exposure pathways to workers on the site and to members of the public outside the site boundary were considered in the calculations. The DRL's represent upper limits for routine emissions of radioactivity from the Chalk River Nuclear Laboratories to the surrounding environment. Actual releases are regulated by Administrative Levels, set lower than the DRL's, and are confirmed by monitoring. (author)

  13. Development of an Integrated Waste Plan for Chalk River Laboratories - 13376

    Jones, L.

    2013-01-01

    To further its Strategic Planning, the Atomic Energy of Canada Limited (AECL) required an effective approach to developing a fully integrated waste plan for its Chalk River Laboratories (CRL) site. Production of the first Integrated Waste Plan (IWP) for Chalk River was a substantial task involving representatives from each of the major internal stakeholders. Since then, a second revision has been produced and a third is underway. The IWP remains an Interim IWP until all gaps have been resolved and all pathways are at an acceptable level of detail. Full completion will involve a number of iterations, typically annually for up to six years. The end result of completing this process is a comprehensive document and supporting information that includes: - An Integrated Waste Plan document summarizing the entire waste management picture in one place; - Details of all the wastes required to be managed, including volume and timings by waste stream; - Detailed waste stream pathway maps for the whole life-cycle for each waste stream to be managed from pre-generation planning through to final disposition; and - Critical decision points, i.e. decisions that need to be made and timings by when they need to be made. A waste inventory has been constructed that serves as the master reference inventory of all waste that has been or is committed to be managed at CRL. In the past, only the waste that is in storage has been effectively captured, and future predictions of wastes requiring to be managed were not available in one place. The IWP has also provided a detailed baseline plan at the current level of refinement. Waste flow maps for all identified waste streams, for the full waste life cycle complete to disposition have been constructed. The maps identify areas requiring further development, and show the complexities and inter-relationships between waste streams. Knowledge of these inter-dependencies is necessary in order to perform effective options studies for enabling

  14. Proposed approach for bedrock characterization at Chalk River Nuclear Laboratories for waste disposal

    Heystee, R.J.; Dixon, D.F.

    1985-07-01

    Low- and intermediate-level wastes (L AND ILW) are produced at the Chalk River Nuclear Laboratories (CRNL) by the operation of reactors for nuclear research and development and by the production of radioisotopes. CRNL also manages L and ILW produced by Canadian research laboratories, universities, hospitals and some industries. An option that is being considered for the disposal of some of these wastes is to emplace them in a shallow rock cavity in fractured crystalline bedrock on the CRNL property. To design such a disposal facility and to evalute its long-term performance, data must be obtained on the geologic and hydrogeologic characteristics of the site. Over the past several years, a variety of airborne, ground surface and borehole geological, geophysical and/or hydrogeological methods have been used to acquire data on some rock mass discontinuities at CRNL. The techniques which are apparently more useful for acquiring these data are described and a proposed approach to site characterization for a shallow rock cavity at CRNL is outlined

  15. AECL'S approach to managing long term liabilities at Chalk River Laboratories. Annex II

    Audet, M.C.

    2006-01-01

    Chalk River Laboratories (CRL) is a large nuclear research and development/ industrial site operated by Atomic Energy of Canada Limited (AECL). Construction of the site started in 1944, and it now includes over 100 buildings/facilities operating in various nuclear fields. A well developed decommissioning programme exists at CRL, with progress being made on decommissioning older redundant buildings, in parallel with ongoing site operations and development. The decommissioning programme is predicated on the assumption that the current nuclear operations will continue over a 100 year operating period, but with a decline towards the end of the period. Although decommissioning and remediation work will be carried out throughout the operational period, residual levels of activity remaining in a few areas will require institutional control (IC) for an assumed period of 300 years. The intention is to complete all necessary active remediation work before the start of the IC period and thereafter rely only on passive means to reduce residual contamination to levels that do not require IC measures. The latter include environmental monitoring, active and passive controls to prevent intrusion, and management controls to prohibit access or development. A formal information and records management programme at CRL has been initiated. (author)

  16. Tritium behavior on a cultivated plot in the 1994 chronic HT release experiment at Chalk River

    Noguchi, H.; Yokoyama, S.; Kinouchi, N.; Murata, M.; Amano, H.; Atarashi, M.; Ichimasa, Y.; Ichimasa, M.

    1995-01-01

    The behavior of HT and HTO in air and surface soil has been studied extensively in the chronic HT release experiment carried out at Chalk River during the summer of 1994. HTO concentrations in air moisture and soil water collected in a cultivated plot showed similar time-variations, increasing rapidly during the first and second days and becoming gradual after the first 3-4 days. The air HTO concentration decreased during and following rainfall but recovered within a day. The rainfall reduced the HTO concentrations in ridge soil water but little in furrows. Time histories of HTO concentrations in air moisture and soil water suggest that the system was near steady-state within a continuous HT release period of 12 days, in spite of the presence of rain during the period. The air HTO concentrations on clear days showed diurnal cycles that were higher during daytime than at night. The experimental field had a very complex soil regime with respect to HT deposits. The deposits to soil surface varied depending on soil conditions. 12 refs., 5 figs

  17. An overview of the waste characterization program at Chalk River Nuclear Laboratories

    Csullog, G.W.; Hardy, D.G.

    1988-01-01

    In the last five years, Chalk River Nuclear Laboratories (CRNL) placed 17,000 m 3 of wastes into storage (excluding contaminated soil and fill). Almost half of the waste was generated off-site. CRNL is now developing IRUS, an Intrusion Resistant Underground Structure, and the IST, an Improved Sand Trench, to replace storage with safe, permanent disposal. IRUS will be used to dispose of wastes with radiologically hazardous lifetimes between 150 and 500 years duration and the IST will be used for wastes with radiologically hazardous lifetimes of less than 150 years. A comprehensive Waste Characterization Program (WCP) is in place to support disposal projects. The WCP is responsible for (1) specifying the manifests for waste shipments; (2) developing and maintaining central databases for waste inventories and analytical data; and (3) developing the technologies and procedures to characterize the radiological and the physical/chemical properties of wastes. WCP work is being performed under the umbrella of a newly developed waste management quality assurance (QA) program. This paper gives an overview of the WCP with an emphasis on the requirements for determining radionuclide inventories in wastes, for implementing record-keeping systems and for maintaining a QA program for disposal operations

  18. Current status of the waste identification program at AECL's Chalk River Laboratories

    Csullog, G.W.; Edwards, N.W.; TerHuurne, M.A.

    1998-01-01

    The management of routine operating waste by Waste Management and Decommissioning (WM and D) at Atomic Energy of Canada Limited's (AECL) Chalk River Laboratories (CRL) is supported by the Waste Identification (WI) Program. The principal purpose of the WI Program is to minimize the cost and the effort associated with waste characterization and waste tracking, which are needed to optimize waste handling, storage and disposal. The major steps in the WI Program are: (1) identify and characterize the processes that generate the routine radioactive wastes accepted by WM and D - radioisotope production, radioisotope use, reactor operation, fuel fabrication, et cetera (2) identify and characterize the routine blocks of waste generated by each process or activity - the initial characterization is based on inference (process knowledge) (3) prepare customized, template data sheets for each routine waste block - templates contain information such as package type, waste material, waste type, solidifying agent, the average non-radiological contaminant inventory, the average radiological contaminant inventory, and the waste class (4) ensure generators 'use the right piece of paper with the right waste' when they transfer waste to WM and D - that is they use the correct template data sheets to transfer routine wastes, by: identifying and marking waste collection points in the generator's facility; ensuring that generators implement effective waste collection/segregation procedures; implementing standard procedures to transfer waste to WM and D; and, auditing waste collection and segregation within a generator's facility (5) determine any additional waste block characterization requirements (is anything needed beyond the original characterization by process knowledge?) This paper describes the WI Program, it provides an example of its implementation, and it summarizes the current status of its implementation for both CRL and non-CRL waste generators. (author)

  19. Spatial analysis of Carbon-14 dynamics in a wetland ecosystem (Duke Swamp, Chalk River Laboratories, Canada)

    Yankovich, T.L.; King-Sharp, K.J.; Carr, J.; Robertson, E.; Killey, R.W.D.; Beresford, N.A.; Wood, M.D.

    2014-01-01

    A detailed survey was conducted to quantify the spatial distribution of 14 C in Sphagnum moss and underlying soil collected in Duke Swamp. This wetland environment receives 14 C via groundwater pathways from a historic radioactive Waste Management Area (WMA) on Atomic Energy Canada Limited (AECL)'s Chalk River Laboratories (CRL) site. Trends in 14 C specific activities were evaluated with distance from the sampling location with the maximum 14 C specific activity (DSS-35), which was situated adjacent to the WMA and close to an area of groundwater discharge. Based on a spatial evaluation of the data, an east-to-west 14 C gradient was found, due to the influence of the WMA on 14 C specific activities in the swamp. In addition, it was possible to identify two groups of sites, each showing significant exponential declines with distance from the groundwater source area. One of the groups showed relatively more elevated 14 C specific activities at a given distance from source, likely due to their proximity to the WMA, the location of the sub-surface plume originating from the WMA, the presence of marsh and swamp habitat types, which facilitated 14 C transport to the atmosphere, and possibly, 14 C air dispersion patterns along the eastern edge of the swamp. The other group, which had lower 14 C specific activities at a given distance from the groundwater source area, included locations that were more distant from the WMA and the sub-surface plume, and contained fen habitat, which is known to act as barrier to groundwater flow. The findings suggest that proximity to source, groundwater flow patterns and habitat physical characteristics can play an important role in the dynamics of 14 C being carried by discharging groundwater into terrestrial and wetland environments. - Highlights: • Groundwater represents an important source of volatile radionuclides to wetlands. • Habitat type influenced 14 C transport from sub-surface to surface environments. • C-14 specific

  20. Assessing inventories of past radioactive waste arisings at Chalk River Laboratories

    Csullog, G.W.; TerHuurne, M.A.; Miller, M.T.; Edwards, N.W.; Hulley, V.R.; McCann, D.J.

    1998-01-01

    Internationally, a great deal of progress has been made in improving the management of currently accumulating and anticipated future radioactive wastes. Progress includes improved waste collection, segregation, characterization and documentation in support of disposal facility licensing and operation. These improvements are not often very helpful for assessing the hazards of wastes collected prior to their implementation, since, internationally, historic radioactive wastes were not managed and documented according to today's methods. This paper provides an overview of Atomic Energy of Canada Limited's (AECL) unique approach to managing its currently accumulating, low-level radioactive wastes at Chalk River Laboratories (CRL) and it describes the novel method AECL-CRL has developed to assess its historic radioactive wastes. Instead of estimating the characteristics of current radioactive wastes on a package-by-package basis, process knowledge is used to infer the average characteristics of most wastes. This approach defers, and potentially avoids, the use of expensive analytical technologies to characterize wastes until a reasonable certainty is gained about their ultimate disposition (Canada does not yet have a licensed radioactive waste disposal facility). Once the ultimate disposition is decided, performance assessments determine if inference characterization is adequate or if additional characterization is required. This process should result in significant cost savings to AECL since expensive, resource-intensive, up-front characterization may not be required for low-impact wastes. In addition, as technological improvements take place, the unit cost of characterization usually declines, making it less expensive to perform any additional characterization for current radioactive wastes. The WIP-III data management system is used at CRL to 'warehouse' the average characteristics of current radioactive wastes. This paper describes how this 'warehouse of information

  1. Hydrogeochemical processes affecting the migration of radionuclides in a fluvial sand aquifer at the Chalk River Nuclear Laboratories

    Jackson, R.E.; Inch, K.J.

    1980-01-01

    In the mid-1950's two experimental disposals of liquid radioactive waste containing about 700 curries of strontium-90 and cesium-137 were made into pits in sandy ground at one of the disposal areas at Chalk River Nuclear Laboratories. Since then, the wastes have migrated into two nearby aquifers and have chromatographically separated into strontium-90 and cesium-137 plumes moving at velocities less than that of the transporting groundwater. Analysis of radioactively contaminated aquifer sediments showed that most of the strontium-90 is exchangeably adsorbed, primarily to feldspars and layer silicates (mainly biotite); the rest is either specifically adsorbed to iron (III) and perhaps manganese (IV) oxhydroxides or fixed to unknown sinks. Less than one half of adsorbed cesium-137 is exchangeable with 0.5 m calcium chloride; the high levels of cesium-137 adsorption and fixation are probably due to its reaction with micaceous minerals. Complexation of strontium-90 and cesium-137 does not appear to be an important factor affecting their transport or adsorption. In studies of groundwater quality or pollution, dissolved oxygen and sulfide should be measured in addition to the redox potential since it allows independent assessment of the redox levels. The latter were found to affect the mobility of multivalent transition metals and nonmetals. (DN)

  2. Management of legacy spent nuclear fuel wastes at the Chalk River Laboratories: operating experience and progress towards waste remediation

    Cox, D.S.; Bainbridge, I.B.; Greenfield, K.R.

    2006-01-01

    AECL has been managing and storing a diversity of spent nuclear fuel, arising from operations at its Chalk River Laboratories (CRL) site over more than 50 years. A subset of about 22 tonnes of research reactor fuels, primarily metallic uranium, have been identified as a high priority for remediation, based on monitoring and inspection that has determined that these fuels and their storage containers are corroding. This paper describes the Fuel Packaging and Storage (FPS) project, which AECL has launched to retrieve these fuels from current storage, and to emplace them in a new above-ground dry storage system, as a prerequisite step to decommissioning some of the early-design waste storage structures at CRL. The retrieved fuels will be packaged in a new storage container, and subjected to a cold vacuum drying process that will remove moisture, and thereby reduce the extent of future corrosion and degradation. The FPS project will enable improved interim storage to be implemented for legacy fuels at CRL, until a decision is made on the ultimate disposition of legacy fuels in Canada. (author)

  3. Pre-operational HTO/HT surveys in the vicinity of the Chalk River Laboratories tritium extraction plant

    Workman, W.J.G.; Brown, R.M.

    1993-08-01

    Surveys of the concentrations of HT and HTO in the atmosphere downwind of the Chalk River Laboratories reactor facilities were carried out in 1986 November, and in 1989 March, April and September under different conditions of air temperature, wind direction, and snow or vegetative cover. HT usually amounted to 1-5% of total tritium, but values up to 20% were observed, probably resulting from preferential removal of HTO. In all of the surveys, the greater persistence in the atmosphere of HT than of HTO was evident. The existing levels of HT are such that they will not be augmented significantly by chronic releases from the Tritium Extraction Plant (TEP) when it comes into operation. Hence, operation of the TEP will not facilitate studies of the environmental behaviour of chronically released HT. However, longer term studies of the distribution of HT from the existing facilities would be worthwhile. Soil and vegetation HTO levels in the study area are reported. Further studies of the distribution of tritium between the air, soil and vegetation in areas subjected to chronic exposure would be valuable

  4. US team measurements during the June 1987 experimental HT release at the Chalk River Nuclear Laboratories, Ontario, Canada

    Jalbert, R.A.; Murphy, C.E.

    1988-01-01

    In June 1987, an experiment was performed at the Chalk River Nuclear Laboratories in Ontario, Canada, to study the oxidation of HT in the environment. The experiment involved a 30-minute release of 100 Ci of HT to the atmosphere at an elevation of one meter. The HTOHT ratios were shown to slowly increase downwind (/approximately/4 /times/ 10/sup /minus/5/ at 50 meters to almost 10/sup /minus/3 at 400 meters) as conversion of HT takes place. For several days after the release, HTO concentrations in the atmosphere remained elevated. Freeze-dried water from vegetation samples was found to be very low in HTO immediately after the release suggesting a very low direct uptake of HTO in air by vegetation. The tritiated water concentration increased during the first day, peaking during the second day (about 400 to 600 pCiml of water at 50 meters from the source) and decreasing by the end of the second day. The organically bound tritium continued to accumulate during the period following exposure (about 10 pCigm dry weight at 50 meters after two days). 4 refs., 6 figs., 2 tabs

  5. U.S. team measurements during the June 1987 experimental HT release at the Chalk River Nuclear Laboratories, Ontario, Canada

    Jalbert, R.A.; Murphy, C.E.

    1988-01-01

    In June 1987, an experiment was performed at the Chalk River Nuclear Laboratories in Ontario, Canada, to study the oxidation of HT in the environment. The experiment involved a 30-minute release of 3.54 TBq (95.7 Ci) of HT to the atmosphere at an elevation of one meter. The HTO/HT ratios were shown to slowly increase downwind (-- 4 x 10/sup -5/ at 50 meters to almost 10/sup -3/ at 400 meters) as conversion of HT takes place. For several days after the release, HTO concentrations in the atmosphere remained elevated. Freeze-dried water from vegetation samples was found to be very low in HTO immediately after the release suggesting a very low direct uptake of HTO in air by vegetation. The free-HTO concentration in vegetation increased during the first day, peaking during the second day (about 1.5 - 3.0 x 10/sup 4/ Bq/L at 50 meters from the source) and decreasing by the end of the second day. The organically bound tritium continued to accumulate during the period following exposure (about 400 Bq/kg dry weight at 50 meters after two days)

  6. HTO and OBT activity concentrations in soil at the historical atmospheric HT release site (Chalk River Laboratories)

    Kim, S.B.; Bredlaw, M.; Korolevych, V.Y.

    2012-01-01

    Tritium is routinely released by the Chalk River Laboratories (CRL) nuclear facilities. Three International HT release experiments have been conducted at the CRL site in the past. The site has not been disturbed since the last historical atmospheric testing in 1994 and presents an opportunity to assess the retention of tritium in soil. This study is devoted to the measurement of HTO and OBT activity concentration profiles in the subsurface 25 cm of soil. In terms of soil HTO, there is no evidence from the past HT release experiments that HTO was retained. The HTO activity concentration in the soil pore water appears similar to concentrations found in background areas in Ontario. In contrast, OBT activity concentrations in soil at the same site were significantly higher than HTO activity concentrations in soil. Elevated OBT appears to reside in the top layer of the soil (0–5 cm). In addition, OBT activity concentrations in the top soil layer did not fluctuate much with season, again, quite in contrast with soil HTO. This result suggests that OBT activity concentrations retained the signature of the historical tritium releases. Highlights: ► At the historical HT release site, HTO and OBT activity concentrations in soil depths were investigated. ► Most organically bound tritium exists in the top layer of the soil. ► The results indicated that OBT activity concentrations can be reflective of historical tritium releases into the environment.

  7. Low-level radioactive river sediment particles originating from the Chalk river nuclear site carry a mixture of radionuclides and metals

    Lind, Ole Christian; Cagno, Simone; Salbu, Brit [Norwegian University of Life Sciences - NMBU, Center of Excellence in Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Aas (Norway); Falkenberg, Gerald [Photon science, DESY, Hamburg (Germany); Janssens, Koen; Nuyts, Gert; Vanmeert, Frederik [AXIL, Department of Chemistry, University of Antwerpen (Belgium); Jaroszewicz, Jakub [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Priest, Nicholas D.; Audet, Marc [Nuclear Science Division, AECL Chalk River Laboratories (Canada)

    2014-07-01

    The Chalk River Laboratory of Atomic Energy of Canada Ltd., site is located on the Ottawa River approximately 200 km northwest of Ottawa, Canada. The site has two large research reactors: NRX, which operated from 1947 to 1991 and NRU, which continues to operate and is used to produce a significant fraction of the world's supply of medical isotopes. During the course of the operation of the NRX reactor small quantities of radioactive particles were discharged to the Ottawa River through a process sewer discharge pipe. These are now located in river bed sediments within a 0.08 km² area close to the discharge pipe. In the present study, selected particles were isolated from riverbed sediments. These were then characterized by environmental scanning electron microscopy with energy dispersive micro X-ray analysis (ESEM-EDX). This was undertaken to obtain information on particle size, structure and the distribution of elements across particle surfaces. Based on the results of ESEM-EDX, particles were selected for X-ray absorption nano-tomography analysis, which provides videos showing the 3D density distribution of the particles. Furthermore, 2D and 3D Synchrotron Radiation based X-ray techniques (micro-X-ray fluorescence; micro-XRF, micro-X-ray absorption near edge spectroscopy; micro-XANES and micro-X-ray diffraction; micro-XRD) with submicron resolution (beam size 0.5 μm) were employed to investigate the elemental and phase composition (micro-XRF/XRD) and oxidation states (micro-XANES) of matrix elements with high spatial resolution and sensitivity. Results show that the particles investigated so far varied according to: 1) <~40 μm diameter sized U fuel particles similar in structure to particles observed from Chernobyl and Krasnoyarsk-26 and 2) larger particles with diameters up to several hundred μm. The larger particles comprised a matrix of low density, sediment material with high density inclusions that contained a range of metals including Cu, Cr, As

  8. Mortality study of Canadian military personnel exposed to radiation: atomic test blasts and Chalk River nuclear reactor clean-ups, 1950's

    Raman, S.; Dulberg, C.S.; Spasoff, R.A.

    1984-08-01

    This report describes a historical cohort study of the group of Canadian military personnel exposed to radiation in the 1950s at atomic bomb test blasts in the U.S. and Australia, and at clean-up operations at the Chalk River Nuclear Laboratories. Overall and cause-specific mortality in the exposed group was compared to that of the control cohort of unexposed military personnel, matched on age, service, rank and trade. Analyses indicated no elevation in the exposed cohort, in overall or cause-specific mortality due to diseases associated with radiation. Since this study was restricted to an investigation of mortality, we must stress that we cannot generalize these results or conclusions to current morbidity experienced by the exposed cohort

  9. Rf structure of superconducting cyclotron for therapy application

    Takekoshi, Hidekuni; Matsuki, Seishi; Mashiko, Katuo; Shikazono, Naomoto.

    1981-01-01

    Advantages of fast neutrons in therapeutical application are now widely recognized. Fast neutrons are generated by bombarding a thick beryllium target with high energy protons and deuterons. The AVF cyclotrons which deliver 50 MeV protons and 25 MeV deuterons are commonly used and are commercially available now. At the treatment usually rotational irradiation is taken to prevent an injury to normal tissue from the high LET effect of fast neutrons. The construction cost of both cyclotrons and isocentric irradiation installation are relatively high, so that the spread of neutron therapy is obstructed. A superconducting cyclotron for neutron therapy application was proposed by a Chalk River group. This low cost design allows the installation to be a dedicated facility located in a hospital, and small size allows installations of the complete cyclotron in a rotatable gantry. The design studies of the superconducting cyclotron based on this idea are going on at Kyoto University. The full scale model experiments for a rf structure of the cyclotron were carried out. (author)

  10. Model description of CHERPAC (Chalk River Environmental Research Pathways Analysis Code); results of testing with post-Chernobyl data from Finland

    Peterson, S-R.

    1994-07-01

    CHERPAC (Chalk River Environmental Research Pathways Analysis Code), a time-dependent code for assessing doses from accidental and routine releases of radionuclides, has been under development since 1987. A complete model description is provide here with equations, parameter values, assumptions and information on parameter distributions for uncertainty analysis. Concurrently, CHERPAC has been used to participate in the two internal model validation exercises BIOMOVS (BIOspheric MOdel Validation Study) and VAMP (VAlidation of Assessment Model Predictions, a co-ordinated research program of the International Atomic Energy Agency). CHERPAC has been tested for predictions of concentrations of 137 Cs in foodstuffs, body burden and dose over time using data collected after the Chernobyl accident of 1986 April. CHERPAC's results for the recent VAMP scenario for southern Finland are particularly accurate and should represent what the code can do under Canadian conditions. CHERPAC's predictions are compared with the observations from Finland for four and one-half years after the accident as well as with the results of the other participating models from nine countries. (author). 18 refs., 23 figs., 2 appendices

  11. Model description of CHERPAC (Chalk River Environmental Research Pathways Analysis Code); results of testing with post-Chernobyl data from Finland

    Peterson, S-R

    1994-07-01

    CHERPAC (Chalk River Environmental Research Pathways Analysis Code), a time-dependent code for assessing doses from accidental and routine releases of radionuclides, has been under development since 1987. A complete model description is provide here with equations, parameter values, assumptions and information on parameter distributions for uncertainty analysis. Concurrently, CHERPAC has been used to participate in the two internal model validation exercises BIOMOVS (BIOspheric MOdel Validation Study) and VAMP (VAlidation of Assessment Model Predictions, a co-ordinated research program of the International Atomic Energy Agency). CHERPAC has been tested for predictions of concentrations of {sup 137}Cs in foodstuffs, body burden and dose over time using data collected after the Chernobyl accident of 1986 April. CHERPAC`s results for the recent VAMP scenario for southern Finland are particularly accurate and should represent what the code can do under Canadian conditions. CHERPAC`s predictions are compared with the observations from Finland for four and one-half years after the accident as well as with the results of the other participating models from nine countries. (author). 18 refs., 23 figs., 2 appendices.

  12. U–Pb, Rb–Sr, and U-series isotope geochemistry of rocks and fracture minerals from the Chalk River Laboratories site, Grenville Province, Ontario, Canada

    Neymark, L.A.; Peterman, Z.E.; Moscati, R.J.; Thivierge, R.H.

    2013-01-01

    Highlights: • AECL evaluates Chalk River Laboratories site as potential nuclear waste repository. • Isotope-geochemical data for rocks and fracture minerals at CRL site are reported. • Zircons from gneiss and granite yielded U–Pb ages of 1472 ± 14 and 1045 ± 6 Ma. • WR Rb–Sr and Pb–Pb systems do not show substantial large-scale isotopic mobility. • U-series and REE data do not support oxidizing conditions at depth in the past 1 Ma. - Abstract: As part of the Geologic Waste Management Facility feasibility study, Atomic Energy of Canada Ltd. (AECL) is evaluating the suitability of the Chalk River Laboratories (CRL) site in Ontario, situated in crystalline rock of the southwestern Grenville Province, for the possible development of an underground repository for low- and intermediate-level nuclear waste. This paper presents petrographic and trace element analyses, U–Pb zircon dating results, and Rb–Sr, U–Pb and U-series isotopic analyses of gneissic drill core samples from the deep CRG-series characterization boreholes at the CRL site. The main rock types intersected in the boreholes include hornblende–biotite (±pyroxene) gneisses of granitic to granodioritic composition, leucocratic granitic gneisses with sparse mafic minerals, and garnet-bearing gneisses with variable amounts of biotite and/or hornblende. The trace element data for whole-rock samples plot in the fields of within-plate, syn-collision, and volcanic arc-type granites in discrimination diagrams used for the tectonic interpretation of granitic rocks. Zircons separated from biotite gneiss and metagranite samples yielded SHRIMP-RG U–Pb ages of 1472 ± 14 (2σ) and 1045 ± 6 Ma, respectively, in very good agreement with widespread Early Mesoproterozoic plutonic ages and Ottawan orogeny ages in the Central Gneiss Belt. The Rb–Sr, U–Pb, and Pb–Pb whole-rock errorchron apparent ages of most of the CRL gneiss samples are consistent with zircon U–Pb age and do not indicate

  13. Results of detailed ground geophysical surveys for locating and differentiating waste structures in waste management area 'A' at Chalk River Laboratories, Ontario

    Tomsons, D.K.; Street, P.J.; Lodha, G.S.

    1999-01-01

    Waste Management Area 'A' (WMA 'A'), located in the outer area of the Chalk River Laboratories (CRL) was in use as a waste burial site from 1946 to 1955. Waste management structures include debris-filled trenches, concrete bunkers and miscellaneous contaminated solid materials, and ditches and pits used for liquid dispersal. In order to update historical records, it was proposed to conduct detailed ground geophysical surveys to define the locations of waste management structures in WMA 'A', assist in planning of the drilling and sampling program to provide ground truth for the geophysics investigation and to predict the nature and locations of unknown/undefined shallow structures. A detailed ground geophysical survey grid was established with a total of 127 grid lines, oriented NNE and spaced one metre apart. The geophysical surveys were carried out during August and September, 1996. The combination of geophysical tools used included the Geonics EM61 metal detector, the GSM-19 magnetometer/gradiometer and a RAMAC high frequency ground penetrating radar system. The geophysical surveys were successful in identifying waste management structures and in characterizing to some extent, the composition of the waste. The geophysical surveys are able to determine the presence of most of the known waste management structures, especially in the western and central portions of the grid which contain the majority of the metallic waste. The eastern portion of the grid has a completely different geophysical character. While historical records show that trenches were dug, they are far less evident in the geophysical record. There is clear evidence for a trench running between lines 30E and 63E at 70 m. There are indications from the radar survey of other trench-like structures in the eastern portion. EM61 data clearly show that there is far less metallic debris in the eastern portion. The geophysical surveys were also successful in identifying previously unknown locations of waste

  14. Chalk as a reservoir

    Fabricius, Ida Lykke

    , and the best reservoir properties are typically found in mudstone intervals. Chalk mudstones vary a lot though. The best mudstones are purely calcitic, well sorted and may have been redeposited by traction currents. Other mudstones are rich in very fine grained silica, which takes up pore space and thus...... basin, so stylolite formation in the chalk is controlled by effective burial stress. The stylolites are zones of calcite dissolution and probably are the source of calcite for porefilling cementation which is typical in water zone chalk and also affect the reservoirs to different extent. The relatively...... have hardly any stylolites and can have porosity above 40% or even 50% and thus also have relatively high permeability. Such intervals have the problem though, that increasing effective stress caused by hydrocarbon production results in mechanical compaction and overall subsidence. Most other chalk...

  15. Results of detailed ground geophysical surveys for locating and differentiating waste structures in waste management area 'A' at Chalk River Laboratories, Ontario

    Tomsons, D.K.; Street, P.J.; Lodha, G.S

    1999-07-01

    Waste Management Area 'A' (WMA 'A'), located in the outer area of the Chalk River Laboratories (CRL) was in use as a waste burial site from 1946 to 1955. Waste management structures include debris-filled trenches, concrete bunkers and miscellaneous contaminated solid materials, and ditches and pits used for liquid dispersal. In order to update historical records, it was proposed to conduct detailed ground geophysical surveys to define the locations of waste management structures in WMA 'A', assist in planning of the drilling and sampling program to provide ground truth for the geophysics investigation and to predict the nature and locations of unknown/undefined shallow structures. A detailed ground geophysical survey grid was established with a total of 127 grid lines, oriented NNE and spaced one metre apart. The geophysical surveys were carried out during August and September, 1996. The combination of geophysical tools used included the Geonics EM61 metal detector, the GSM-19 magnetometer/gradiometer and a RAMAC high frequency ground penetrating radar system. The geophysical surveys were successful in identifying waste management structures and in characterizing to some extent, the composition of the waste. The geophysical surveys are able to determine the presence of most of the known waste management structures, especially in the western and central portions of the grid which contain the majority of the metallic waste. The eastern portion of the grid has a completely different geophysical character. While historical records show that trenches were dug, they are far less evident in the geophysical record. There is clear evidence for a trench running between lines 30E and 63E at 70 m. There are indications from the radar survey of other trench-like structures in the eastern portion. EM61 data clearly show that there is far less metallic debris in the eastern portion. The geophysical surveys were also successful in identifying

  16. An investigation of the suitability of the Chalk River site to host a geologic waste management facility for CRL's low and intermediate level wastes

    Thompson, P.; Baumgartner, P.; Chan, T.; Kitson, C.; Kozak, E.; Man, A.; Martino, J.; Stroes-Gascoyne, S.; Beaton, D.; Sharp, K.; Thivierge, R.

    2011-01-01

    Atomic Energy of Canada Limited (AECL) is investigating the suitability of the Chalk River Laboratories (CRL) site for hosting a Geologic Waste Management Facility (GWMF) as part of the Nuclear Legacy Liabilities Program (NLLP) funded through Natural Resources Canada (NRCan). The GWMF is envisioned to be an underground engineered-geological repository consisting of shafts, access tunnels and emplacement caverns located at a nominal depth of 500 to 1000 m in the bedrock at the CRL site. A 5-year-long pre-project study was started in 2006 to assess the feasibility of the bedrock at the CRL site to host a GWMF. The pre-project feasibility study began with a review of various previous geological investigations performed in the bedrock at the CRL site. The 2006-2010 pre-project feasibility study involved exploring the geoscience and engineering characteristics of the bedrock to depths of over one kilometre at the CRL site through surface investigations and the drilling and testing of seven new deep characterization boreholes into the CRL bedrock. The collected information and interpretations were used to construct three-dimensional (3D) deterministic computer models of the geology of the bedrock at the CRL site and surrounding area and of the associated groundwater-flow regime. In order to technically assess the suitability of the CRL site, the GWMF feasibility study has conservatively assumed that all of the legacy and forecast Low and Intermediate Level Waste (LILW) at CRL would report to it. The 3D deterministic models were used within a preliminary performance and safety assessment model to assess the long-term safety of a hypothetical GWMF at the CRL site on the basis of future radionuclide and toxic substance releases. Other items important to a preliminary performance and safety assessment include an inventory of CRL's radioactive wastes and other contaminants that could be placed in the GWMF, the creation of the engineered waste emplacement rooms and

  17. Facilities for Waste Management at Chalk River, Canada; Les Installations d'Elimination et d'Utilisation des Dechets a Chalk River, Canada; 041e 0411 041e 0420 0423 0414 041e 0412 ; Instalaciones Utilizadas para el Provechamiento y Evacuacion de Desechos Radiactivos en Chalk River, Canada

    Mawson, C. A.; Russell, A. E. [Environmental Research Branch, Atomic Energy of Canada Ltd. (Canada)

    1960-07-01

    The waste disposal areas used by the Atomic Energy of Canada Limited are situated in a rock basin filled with glacial till and sand, draining into the Ottawa River. Low-activity liquid effluent is run into pits in the sand, which are filled with small rocks to prevent contact of liquid with the air. Medium- level liquid is mixed with cement in drums which are stacked and totally enclosed in concrete trenches; medium-level solids are buried in concrete-lined trenches; high-level solids are placed in holes lined with steel or concrete piping. Special facilities are provided for organic liquids and bottled wastes. Details will be given of the structural work and procedures, with an outline of the results of environmental monitoring. (author) [French] Les zones d'elimination utilisees par l'Atomic Energy of Canada Limited sont situees dans un bassin rocheux, rempli de blocs erratiques et'de sable, dont les eaux s'ecoulent dans la riviere Ottawa. Les effluents liquides de faible activite sont verses dans des puits creuses dans le sable, qui sont ensuite remplis de petites pierres pour prevenir le contact du liquide avec l'air. Les dechets liquides d'activite moyenne sont melanges a du ciment dans des barils qui sont entasses et completement enfermes dans des tranchees betonnees; les dechets solides d'activite moyenne sont enfouis dans des tranchees bordees de beton; les dechets solides de haute activite sont places dans des trous bordes de conduites d'acier ou de ciment. Des installations speciales sont prevues pour les liquides organiques et les dechets enfermes dans des recipients en forme de bouteilles. Le memoire expose en detail les travaux d'amenagement et les methodes suivies; il donne un apercu des resultats du controle du milieu ambiant. (author) [Spanish] Las zonas utilizadas por la Atomic Energy of Canada Limited para la evacuacion de desechos radiactivos estan situadas en una cuenca rocosa recubierta de limo y arena del periodo glacial, que desemboca en el

  18. Chalk Catchment Transit Time: Unresolved Issues

    Darling, W. G.; Gooddy, D. C. [British Geological Survey, Crowmarsh Gifford, Wallingford, Oxfordshire (United Kingdom); Barker, J. A. [School of Civil Engineering and the Environment, University of Southampton, Southampton (United Kingdom); Robinson, M. [Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford, Oxfordshire (United Kingdom)

    2013-07-15

    The mean transit time (MTT) of a catchment is the average residence time of water from rainfall to river outflow at the foot of the catchment. As such, MTT has important water quality as well as resource implications. Many catchments worldwide have been measured for MTT using environmental isotopes, yet the Chalk, an important aquifer in NW Europe, has received little attention in this regard. The catchment of the River Lambourn in southern England has been intermittently studied since the 1960s using isotopic methods. A tritium peak measured in the river during the 1970s indicates an apparent MTT of {approx}15 years, but the thick unsaturated zone (average {approx}50 m) of the catchment suggests that the MTT should be much greater because of the average downward movement through the Chalk of {approx}1 m/a consistently indicated by tritium and other tracers. Recent work in the catchment using SF{sub 6} as a residence time indicator has given groundwater ages in the narrow range 11-18 yrs, apparently supporting the river tritium data but in conflict with the unsaturated zone data even allowing for a moderate proportion of rapid bypass flow. The MTT of the catchment remains unresolved for the time being. (author)

  19. Use of borehole-geophysical logs and hydrologic tests to characterize crystalline rock for nuclear-waste storage, Whiteshell Nuclear Research Establishment, Manitoba, and Chalk River Nuclear Laboratory, Ontario, Canada

    Davison, C.C.

    1982-12-01

    A number of borehole methods were used in the investigation of crystalline rocks at Whiteshell Nuclear Research Establishment and Chalk River Nuclear Laboratory in Canada. The selection of a crystalline-rock mass for the storage of nuclear waste likely will require the drilling and testing of a number of deep investigative boreholes in the rock mass. Although coring of at least one hole in each new area is essential, methods for making in-situ geophysical and hydrologic measurements can substitute for widespread coring and result in significant savings in time and money. Borehole-geophysical logging techniques permit the lateral extrapolation of data from a core hole. Log response is related to rock type, alteration, and the location and character of fractures. The geophysical logs that particularly are useful for these purposes are the acoustic televiewer and acoustic waveform, neutron and gamma, resistivity, temperature, and caliper. The acoustic-televiewer log of the borehole wall can provide high resolution data on the orientation and apparent width of fractures. In situ hydraulic tests of single fractures or fracture zones isolated by packers provide quantitative information on permeability, extent, and interconnection. The computer analysis of digitized acoustic waveforms has identified a part of the waveform that has amplitude variations related to permeabilities measured in the boreholes by packer tests. 38 refs., 37 figs., 4 tabs

  20. Medical Cyclotrons

    Friesel, D. L.; Antaya, T. A.

    Particle accelerators were initially developed to address specific scientific research goals, yet they were used for practical applications, particularly medical applications, within a few years of their invention. The cyclotron's potential for producing beams for cancer therapy and medical radioisotope production was realized with the early Lawrence cyclotrons and has continued with their more technically advanced successors — synchrocyclotrons, sector-focused cyclotrons and superconducting cyclotrons. While a variety of other accelerator technologies were developed to achieve today's high energy particles, this article will chronicle the development of one type of accelerator — the cyclotron, and its medical applications. These medical and industrial applications eventually led to the commercial manufacture of both small and large cyclotrons and facilities specifically designed for applications other than scientific research.

  1. Cyclotrons: 1978

    Martin, J.A.

    1978-01-01

    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

  2. ChalkBoard: Mapping Functions to Polygons

    Matlage, Kevin; Gill, Andy

    ChalkBoard is a domain specific language for describing images. The ChalkBoard language is uncompromisingly functional and encourages the use of modern functional idioms. ChalkBoard uses off-the-shelf graphics cards to speed up rendering of functional descriptions. In this paper, we describe the design of the core ChalkBoard language, and the architecture of our static image generation accelerator.

  3. The sedimentology of redeposited chalk

    Anderskouv, Kresten; Surlyk, Finn; Gale, Andy

    Redeposited facies in the Upper Cretaceous Chalk Group constitute major hydrocarbon reservoirs in the North Sea Central Graben. Existing facies models are largely based on publications from the early 1980's dealing with core material from the Norwegian sector. However, the recognition, interpreta...

  4. Nickel adsorption on chalk and calcite

    Belova, Dina Alexandrovna; Lakshtanov, Leonid; Carneiro, J.F.

    2014-01-01

    Nickel uptake from solution by two types of chalk and calcite was investigated in batch sorption studies. The goal was to understand the difference in sorption behavior between synthetic and biogenic calcite. Experiments at atmospheric partial pressure of CO2, in solutions equilibrated with calcite...... = - 1.12 on calcite and log KNi = - 0.43 and - 0.50 on the two chalk samples. The study confirms that synthetic calcite and chalk both take up nickel, but Ni binds more strongly on the biogenic calcite than on inorganically precipitated, synthetic powder, because of the presence of trace amounts...... of polysaccharides and clay nanoparticles on the chalk surface....

  5. Slope failure of chalk channel margins

    Gale, A.; Anderskouv, Kresten; Surlyk, Finn

    2015-01-01

    provide evidence for recurring margin collapse of a long-lived Campanian channel. Compressionally deformed and thrust chalk hardgrounds are correlated to thicker, non-cemented chalk beds that form a broad, gentle anticline. These chalks represent a slump complex with a roll-over anticline of expanded, non......-cemented chalk in the head region and a culmination of condensed hardgrounds in the toe region. Observations strongly suggest that the slumping represents collapse of a channel margin. Farther northwards, the contemporaneous succession shows evidence of small-scale penecontemporaneous normal faulting towards...

  6. Adsorption Properties of Chalk Reservoir Materials

    Okhrimenko, Denis

    /gas adsorption properties of synthetic calcium carbonate phases (calcite, vaterite and aragonite) with chalk, which is composed of biogenic calcite (>98%). In combination with data from nanotechniques, the results demonstrate the complexity of chalk behavior and the role of nanoscale clay particles. The results...

  7. Self Compacting Concrete with Chalk Filler

    Sørensen, Eigil V.

    2007-01-01

    Utilisation of Danish chalk filler has been investigated as a means to produce self compacting concrete (SCC) at lower strength levels for service in non aggressive environments. Stable SCC mixtures were prepared at chalk filler contents up to 60% by volume of binder to yield compressive strengths...

  8. Waste minimization at Chalk River Laboratories

    Kranz, P.; Wong, P.C.F.

    2011-01-01

    Waste minimization supports Atomic Energy of Canada Limited (AECL) Environment Policy with regard to pollution prevention and has positive impacts on the environment, human health and safety, and economy. In accordance with the principle of pollution prevention, the quantities and degree of hazard of wastes requiring storage or disposition at facilities within or external to AECL sites shall be minimized, following the principles of Prevent, Reduce, Reuse, and Recycle, to the extent practical. Waste minimization is an important element in the Waste Management Program. The Waste Management Program has implemented various initiatives for waste minimization since 2007. The key initiatives have focused on waste reduction, segregation and recycling, and included: 1) developed waste minimization requirements and recycling procedure to establish the framework for applying the Waste Minimization Hierarchy; 2) performed waste minimization assessments for the facilities, which generate significant amounts of waste, to identify the opportunities for waste reduction and assist the waste generators to develop waste reduction targets and action plans to achieve the targets; 3) implemented the colour-coded, standardized waste and recycling containers to enhance waste segregation; 4) established partnership with external agents for recycling; 5) extended the likely clean waste and recyclables collection to selected active areas; 6) provided on-going communications to promote waste reduction and increase awareness for recycling; and 7) continually monitored performance, with respect to waste minimization, to identify opportunities for improvement and to communicate these improvements. After implementation of waste minimization initiatives at CRL, the solid waste volume generated from routine operations at CRL has significantly decreased, while the amount of recyclables diverted from the onsite landfill has significantly increased since 2007. The overall refuse volume generated at CRL (including solid radioactive waste, inactive waste and recyclables) decreased by 14% from 2007 to 2010. It should be noted that the workforce at CRL increased by approximately 15% during the same period. When considering the refuse volume data on a per capita basis, the volume of overall refuse per person was reduced from 3.03 m 3 /person in 2007 to 2.25 m 3 /person in 2010. This represents a 26% reduction in refuse in three years. This paper describes the waste minimization initiatives and the achievements at CRL in details, and also the planned initiatives in future. (author)

  9. Non-destructive testing at Chalk River

    Hilborn, J.W.

    1976-01-01

    In 1969 CRNL recognized the need for a strong group skilled in non-destructive test procedures. Within two years a new branch called Quality Control Branch was staffed and working. This branch engages in all aspects of non-destructive testing including development of new techniques, new applications of known technology, and special problems in support of operating reactors. (author)

  10. Waste minimization at Chalk River Laboratories

    Kranz, P.; Wong, P.C.F. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2011-07-01

    Waste minimization supports Atomic Energy of Canada Limited (AECL) Environment Policy with regard to pollution prevention and has positive impacts on the environment, human health and safety, and economy. In accordance with the principle of pollution prevention, the quantities and degree of hazard of wastes requiring storage or disposition at facilities within or external to AECL sites shall be minimized, following the principles of Prevent, Reduce, Reuse, and Recycle, to the extent practical. Waste minimization is an important element in the Waste Management Program. The Waste Management Program has implemented various initiatives for waste minimization since 2007. The key initiatives have focused on waste reduction, segregation and recycling, and included: 1) developed waste minimization requirements and recycling procedure to establish the framework for applying the Waste Minimization Hierarchy; 2) performed waste minimization assessments for the facilities, which generate significant amounts of waste, to identify the opportunities for waste reduction and assist the waste generators to develop waste reduction targets and action plans to achieve the targets; 3) implemented the colour-coded, standardized waste and recycling containers to enhance waste segregation; 4) established partnership with external agents for recycling; 5) extended the likely clean waste and recyclables collection to selected active areas; 6) provided on-going communications to promote waste reduction and increase awareness for recycling; and 7) continually monitored performance, with respect to waste minimization, to identify opportunities for improvement and to communicate these improvements. After implementation of waste minimization initiatives at CRL, the solid waste volume generated from routine operations at CRL has significantly decreased, while the amount of recyclables diverted from the onsite landfill has significantly increased since 2007. The overall refuse volume generated at CRL (including solid radioactive waste, inactive waste and recyclables) decreased by 14% from 2007 to 2010. It should be noted that the workforce at CRL increased by approximately 15% during the same period. When considering the refuse volume data on a per capita basis, the volume of overall refuse per person was reduced from 3.03 m{sup 3}/person in 2007 to 2.25 m{sup 3}/person in 2010. This represents a 26% reduction in refuse in three years. This paper describes the waste minimization initiatives and the achievements at CRL in details, and also the planned initiatives in future. (author)

  11. Medical cyclotrons

    Wolf, A.P.

    1976-01-01

    Cyclotrons as tools for therapy and for the production of radionuclides for use in nuclear medicine have been extensively reviewed in the literature. The current world status with respect to cyclotrons used primarily for research, development and application in nuclear medicine is reviewed here in the context of geographical distribution and type of use, presently available commercial types, machine characteristics and trends. Aspects of design requirements from a user perspective such as machine, beam and target characteristics are covered. Some special problems concerning many factors which can lead to effective production of the desired radionuclide or product are considered in light of machine characteristics. Consideration is also given to future directions for accelerators in nuclear medicine

  12. Electromagnetic cyclotron harmonic waves

    Ohnuma, T.; Watanabe, T.; Hamamatsu, K.

    1981-09-01

    Electromagnetic electron cyclotron harmonic waves just below the electron cyclotron harmonics are investigated numerically and experimentally. Backward waves which are observed to propagate nearly perpendicular to the magnetic field just below the electron cyclotron frequency in a high density magnetoplasma are confirmed to be in accord with the theoretical electromagnetic cyclotron waves. (author)

  13. Adsorption of hydrocarbons in chalk reservoirs

    Madsen, L.

    1996-12-31

    The present work is a study on the wettability of hydrocarbon bearing chalk reservoirs. Wettability is a major factor that influences flow, location and distribution of oil and water in the reservoir. The wettability of the hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. Organic compounds such as carboxylic acids are found in formation waters from various hydrocarbon reservoirs and in crude oils. In the present investigation the wetting behaviour of chalk is studied by the adsorption of the carboxylic acids onto synthetic calcite, kaolinite, quartz, {alpha}-alumina, and chalk dispersed in an aqueous phase and an organic phase. In the aqueous phase the results clearly demonstrate the differences between the adsorption behaviour of benzoic acid and hexanoic acid onto the surfaces of oxide minerals and carbonates. With NaCl concentration of 0.1 M and with pH {approx_equal} 6 the maximum adsorption of benzoic acid decreases in the order: quartz, {alpha}-alumina, kaolinite. For synthetic calcite and chalk no detectable adsorption was obtaind. In the organic phase the order is reversed. The maximum adsorption of benzoic acid onto the different surfaces decreases in the order: synthetic calcite, chalk, kaolinite and quartz. Also a marked difference in adsorption behaviour between probes with different functional groups onto synthetic calcite from organic phase is observed. The maximum adsorption decreases in the order: benzoic acid, benzyl alcohol and benzylamine. (au) 54 refs.

  14. Chalk Formations as Natural Barriers towards Radionuclide Migration

    Pedersen, Walther Batsberg; Carlsen, Lars; Jensen, Bror Skytte

    1985-01-01

    A series of chalk samples from the cretaceous formation overlying the Erslev salt dome have been studied in order to establish permeabilities, porosities, dispersion-, diffusion-, and sorption characteristics of the chalk. The chalk was found to be porous (∊≈0.4), however, of rather low...

  15. Chalk: composition, diagenesis and physical properties

    Fabricius, Ida Lykke

    2007-01-01

    Chalk is a sedimentary rock of unusually high homogeneity on the scale where physical properties are measured, but the properties fall in wide ranges. Chalk may thus be seen as the ideal starting point for a physical understanding of rocks in general. Properties as porosity, permeability, capillary...... involving clay, silica, and calcite are interlinked, but progress differently in different localities. This partly depends on primary sediment composition, including organic content, which may induce the formation of concretions by microbial action. The diagenetic processes also depend on water depth, rate...

  16. Cyclotrons as mass spectrometers

    Clark, D.J.

    1984-04-01

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

  17. Compaction of microfossil and clay-rich chalk sediments

    Fabricius, Ida Lykke

    2001-01-01

    The aim of this study was to evaluate the role of microfossils and clay in the compaction of chalk facies sediments. To meet this aim, chalk sediments with varying micro texture were studied. The sediments have been tested uniaxially confined in a stainless-steel compaction cell. The sediments are......: 1) Pure carbonate chalk with mudstone texture from Stevns Klint (Denmark), 2) Relatively pure chalk sediments with varying content of microfossils from the Ontong Java Plateau (Western Pacific), 3) Clay-rich chalk and mixed sediments from the Caribbean. The tested samples were characterised...

  18. Cyclotron waves in plasma

    Lominadse, D.G.

    1975-01-01

    The book deals with fundamental physical concepts of the theory of cyclotron waves and cyclotron instabilities conditioned by the presence in plasma of direct or alternating electric currents passing in it perpendicularily to a magnetic field. A great variety of problems is considered connected with the linear theory of cyclotron oscillations in equilibrium and electron plasma of metals and semiconductors. Parametric excitations of electron cyclotron oscillations of plasma in an alternating electric field are studied. Particular attention is paid to the investigation of plasma turbulence arising as a result of development of cyclotron instabilities. Experimental data are discussed and compared with theoretical results

  19. Cyclotron waves in plasma

    Lominadze, D G

    2013-01-01

    Cyclotron Waves in Plasma is a four-chapter text that covers the basic physical concepts of the theory of cyclotron waves and cyclotron instabilities, brought about by the existence of steady or alternating plasma currents flowing perpendicular to the magnetic field.This book considers first a wide range of questions associated with the linear theory of cyclotron oscillations in equilibrium plasmas and in electron plasmas in metals and semiconductors. The next chapter deals with the parametric excitation of electron cyclotron oscillations in plasma in an alternating electric field. A chapter f

  20. The End of "Chalk and Talk"

    Barlow, Tim

    2012-01-01

    "Chalk and talk" had been the staple pedagogical approach of my Science teaching practice since entering the profession. I felt that there was a great deal of information that I must impart to my students. My tried and tested way to deliver information to my students had always been simply to stand in front of them and tell it to them... So what…

  1. Process for treating oil-chalk

    1925-10-20

    A process for treating oil-chalk or similar oil-containing minerals is characterized in that the material is treated in a stream of air diluted with indifferent gases at a temperature of about 150/sup 0/ to 160/sup 0/C.

  2. Medical applications of cyclotrons

    Jean, R.; Fauchet, M.

    1978-01-01

    Isochronous cyclotrons used to accelerate different charged particles (protons, deuterons, alphas...) at variable energies, have important medical applications, for neutron teletherapy, in vivo or in vitro activation analysis or production of short-lived radioisotopes for nuclear medicine. The characteristics of the cyclotron presently available are described for these three applications (low energy 'compact' cyclotrons, cyclotrons of intermediate and high energies), and their advantages are discussed from the points of view of the medical requirements, the financial investments and the results obtained. (orig.) [de

  3. MICHIGAN: Cyclotron conference

    Anon.

    1984-01-01

    A sense of excitement was in the air as cyclotron physicists and engineers from 17 countries convened on 30 April for the opening of the Tenth International Conference on Cyclotrons and Their Applications. Some 50 years after its invention, the redoubtable cyclotron remains a topic of compelling current interest. Cyclotron experts gathered at Michigan State University's Kellogg Center to hear of latest developments, of progress and successes on new machines which had come into operation, of new projects which were underway, and of dreams which lay ahead

  4. MICHIGAN: Cyclotron conference

    Anon.

    1984-10-15

    A sense of excitement was in the air as cyclotron physicists and engineers from 17 countries convened on 30 April for the opening of the Tenth International Conference on Cyclotrons and Their Applications. Some 50 years after its invention, the redoubtable cyclotron remains a topic of compelling current interest. Cyclotron experts gathered at Michigan State University's Kellogg Center to hear of latest developments, of progress and successes on new machines which had come into operation, of new projects which were underway, and of dreams which lay ahead.

  5. [Cyclotron based nuclear science

    1989-06-01

    This report contains papers on the following topics: Heavy ion reactors, nuclear structure and fundamental interactions; atomic and materials studies; nuclear theory; and superconducting cyclotron and instrumentation

  6. Influence of effective stress coefficient on mechanical failure of chalk

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Hjuler, M.L.

    2012-01-01

    The Effective stress coefficient is a measure of how chalk grains are connected with each other. The stiffness of chalk may decrease if the amount of contact cements between the grains decreases, which may lead to an increase of the effective stress coefficient. We performed CO2 injection in chal...... precise failure strength of chalk during changed stress state and under the influence of chemically reactive fluids during production of hydrocarbon and geological storage CO2....

  7. Effect of Fluid Dynamic Viscosity on the Strength of Chalk

    Hedegaard, K.; Fabricius, Ida Lykke

    The mechanical strength of high porosity and weakly cemented chalk is affected by the fluid in the pores. In this study, the effect of the dynamic viscosity of non-polar fluids has been measured on outcrop chalk from Sigerslev Quarry, Stevns, Denmark. The outcome is that the measured strength...... of the chalk decreases with increasing dynamic viscosity. The proposed qualitative explanation is that pressure difference supports and enhances the generation of microscopic shear and tensile failures....

  8. Water in chalk reservoirs: 'friend or foe?'

    Hjuler, Morten Leth

    2004-01-01

    Most of the petroleum fields in the Norwegian sector of the North Sea are sandstone reservoirs; the oil and gas are trapped in different species of sandstone. But the Ekofisk Field is a chalk reservoir, which really challenges the operator companies. When oil is produced from chalk reservoirs, water usually gets in and the reservoir subsides. The subsidence may be expensive for the oil companies or be used to advantage by increasing the recovery rate. Since 60 per cent of the world's petroleum reserves are located in carbonate reservoirs, it is important to understand what happens as oil and gas are pumped out. Comprehensive studies at the Department of Petroleum Technology and Applied Geophysics at Stavanger University College in Norway show that the mechanical properties of chalk are considerably altered when the pores in the rock become saturated with oil/gas or water under different stress conditions. The processes are extremely complex. The article also maintains that the effects of injecting carbon dioxide from gas power plants into petroleum reservoirs should be carefully studied before this is done extensively

  9. Medical cyclotron facilities

    1984-09-01

    This report examines the separate proposals from the Austin Hospital and the Australian Atomic Energy Commission for a medical cyclotron facility. The proponents have argued that a cyclotron facility would benefit Australia in areas of patient care, availability and export of radioisotopes, and medical research. Positron emission tomography (PET) and neutron beam therapy are also examined

  10. 20 years Rossendorf cyclotron

    1978-08-01

    On the occasion of the 20th anniversary of initiating of the Rossendorf cyclotron accounts are given of most important works and results in the field of accelerator engineering and utilization of this machine. The reports show the trend of development and actual spectrum of application. The enclosed literature lists give a survey of technical and experimental works at cyclotron. (author)

  11. Vancouver Cyclotron Conference

    Clark, David J.

    1993-01-01

    Although no longer on the high energy frontier, the cyclotron field is still a major scientific growth area. Its progress is highlighted at the international conference on cyclotron design, development and utilization held at intervals of about three years, under the auspices of the International Union of Pure and Applied Physics (IUPAP). Vancouver, surrounded by mountains, water and some cyclotrons, provided a pleasant setting for the 13th Conference, held last summer. With over 200 cyclotrons in operation around the world, the attendance, 241 delegates and 26 industrial exhibitors, was a near record, reflecting the flourishing state of the field. The early sessions covered the initial operation of new or upgraded cyclotron facilities. Major facilities completed since the previous Conference in Berlin in May 1989 included the 400 MeV ring cyclotron at Osaka, the U400M cyclotron at Dubna which will be coupled to the U400 to give 20 MeV nucléon uranium beams, the 130 MeV cyclotron at Jyvaskyla (in Finland, the furthest north!), the 110 MeV JAERI machine in Japan, and the 65 MeV proton therapy cyclotron in Nice. Among the facility upgrades were the KFA cyclotron at Julich which will inject the 2.5 GeV storage ring COSY, and the addition of an FM mode to the K=200 CW mode at Uppsala to give protons up to 180 MeV. The impressive current of 1.5 mA at 72 MeV obtained from the PSI Injector II will soon be injected into the 590 MeV ring

  12. New insight into the microtexture of chalks from NMR analysis

    Faÿ-Gomord, Ophélie; Soete, Jeroen; Katika, Konstantina

    2016-01-01

    An integrated petrographical and petrophysical study was carried out on a set of 35 outcrop chalk samples, covering a wide range of lithologies and textures. In this study various chalk rock-types have been characterized, in terms of microtextures and porous network, by integrating both geologica...

  13. Dissection of genetic architecture of grain chalk using NIR spectroscopy

    Chalk is a major quality characteristic that causes grain breakage during milling and loss of crop value. In this study, we sought to elucidate the quantitatively inherited grain chalk trait in rice and to conduct genome-wide association mapping to identify SNPs and candidate genes associated with ...

  14. Chalk effect on PVC cross-linking under irradiation

    Chudinova, V.V.; Guzeev, V.V.; Mozzhukhin, V.B.; Pomerantseva, Eh.G.; Nozrina, F.D.; Zhil'tsov, V.V.; Zubov, V.P.

    1994-01-01

    Effect of nonmodified and modified chalk on curing degree of polymer matrix was studied under-irradiation of PVC-compositions. Films of the compositions (100 mass part 7 PVC, 0-100 mas.part of chalk, 2.5 - lead sulfate, 1.5 - lead stearate and 0.3 - glycerin) were irradiated up to absorbed dose 0.1 MGy in an inert medium. Content of gel-fraction after boiling in THF was determined with use of IR spectroscopy. It was established, that intensive dehydrochlorination and polymer curing took place on chalk particle surface. Network fixed strongly chalk particles. However, chalk inhibited processes of dehydrochlorination and PVC curing, increasing amount of noncured PVC in polymer matrix

  15. Controls on Cementation in a Chalk Reservoir

    Meireles, Leonardo Teixeira Pinto; Hussein, A.; Welch, M.J.

    In this study, we identify different controls on cementation in a chalk reservoir. Biot’s coefficient, a measure of cementation, stiffness and strength in porous rocks, is calculated from logging data (bulk density and sonic Pwave velocity). We show that Biot’s coefficient is correlated...... to the water saturation of the Kraka reservoir and is partly controlled by its stratigraphic sub-units. While the direct causal relationship between Biot’s coefficient and water saturation cannot be extended for Biot’s coefficient and porosity, a correlation is also identified between the two, implying...

  16. Controls on Cementation in a Chalk Reservoir

    Meireles, Leonardo Teixeira Pinto; Hussein, A.; Welch, M.J.

    2017-01-01

    In this study, we identify different controls on cementation in a chalk reservoir. Biot’s coefficient, a measure of cementation, stiffness and strength in porous rocks, is calculated from logging data (bulk density and sonic Pwave velocity). We show that Biot’s coefficient is correlated...... that some degree of pore filling cementation occurred in Kraka (Alam, 2010). Lack of correlation between Biot’s coefficient and Gamma Ray (GR) indicates that the small amount of clay present is generally located in the pore space, thus not contributing to frame stiffness. While there was no compositional...... control on cementation via clay, we could infer that stratigraphy impacts on the diagenetic process....

  17. Change of Static and Dynamic Elastic Properties due to CO² Injection in North Sea Chalk

    Alam, Mohammad Monzurul; Hjuler, M.L.; Christensen, H.F.

    2012-01-01

    important in enhanced oil recovery by CO2 injection (CO2-EOR) in chalk as, chalk reservoirs are vulnerable to compaction under changed stress and pore fluid. From South Arne field, North Sea, we used Ekofisk Formation chalk having approximately 20% non-carbonate and Tor Formation chalk having less than 5...

  18. Cyclotrons for isotope production

    Milton, B.F.; Stevenson, N.R.

    1995-06-01

    Cyclotrons continue to be efficient accelerators for radioisotope 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 indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology, and isotope production, as they relate to the new generation of commercial cyclotrons. We will also discuss the possibility of systems capable of extracted energies up to 100 MeV and extracted beam currents of up to 2.0 mA. (author). 6 refs., 2 tabs., 3 figs

  19. Synchro-cyclotron

    CERN PhotoLab

    1972-01-01

    The electromagnetic coil which forms the first section of the proton extraction channel in the improved synchro-cyclotron. The photograph shows the positioning gear and the current septum. An extraction efficiency above 50% is expected.

  20. To What Degree Thermal Cycles Affect Chalk Strength

    Livada, Tijana; Nermoen, Anders; Korsnes, Reidar Inger

    triaxial cell experiments. For dry rock, no significant effects of temperature cycling was found on average tensile strength, however the range of the tensile failure stress is doubled for the samples exposed to 50 temperature cycles, as opposed to those to none. For water saturated cores, the temperature......Chalk reservoirs could potentially undergo destabilization as the result of repeated cold water injection into a hot reservoir during water flooding. Preliminary results of an ongoing study are presented in this paper, which compare the impact of temperature cycling on mechanical behavior on dry...... and water saturated chalk. Sixty disks of dry Kansas chalk exposed to different number of temperature cycles were tested for tensile strength using a Brazilian test. Changes in elastic properties as function of number of temperature cycles of the same chalk, but now saturated in water, were studied using...

  1. Kolmanda aastatuhande piraadid / kommenteerinud Peter Chalk ja Gordan Van Hook

    2009-01-01

    Piraatlusest Somaalia piirkonnas ja rahvusvahelistest dokumentidest piraatluse vastu võitlemiseks 21. sajandil. Kommenteerivad uurimiskeskuse RAND Corporation vanempoliitanalüütik Peter Chalk ja transpordikompanii Maersk Line innovatsiooni ja arenduse vanemdirektor Gordan Van Hook

  2. Slow wave cyclotron maser

    Kho, T.H.; Lin, A.T.

    1988-01-01

    Cyclotron masers such as Gyrotrons and the Autoresonance Masers, are fast wave devices: the electromagnetic wave's phase velocity v rho , is greater than the electron beam velocity, v b . To be able to convert the beam kinetic energy into radiation in these devices the beam must have an initial transverse momentum, usually obtained by propagating the beam through a transverse wiggler magnet, or along a nonuniform guide magnetic field before entry into the interaction region. Either process introduces a significant amount of thermal spread in the beam which degrades the performance of the maser. However, if the wave phase velocity v rho v b , the beam kinetic energy can be converted directly into radiation without the requirement of an initial transverse beam momentum, making a slow wave cyclotron maser a potentially simpler and more compact device. The authors present the linear and nonlinear physics of the slow wave cyclotron maser and examine its potential for practical application

  3. Cyclotron to Oslo University

    Sandstad, J.

    1978-01-01

    The new cyclotron was delivered to Oslo University on September 21st 1978, and was mannfactured by A/B Scandtronix of Uppsala, Sweden. The contract price was 6,8 million Norwegian kroner and installation will cost a further 4 million. The main specifications are given. The energy will be 36 MeV for protons and alpha particles, 18 MeV deuterons and 48 MeV for helium 3. The principle of a cyclotron is briefly described. While the primary purpose of the machine is nuclear research it is also planned to produce short-lived radioisotopes, primarily iodine 123. (JIW)

  4. How cyclotrons work

    Nolan, D.

    1992-01-01

    The operating principles of a cyclic accelerator are presented based on the IBA Cyclone 30 negative ion cyclotron, selected for the Australia's first medical cyclotron. Its main features are: acceleration with variable energy of between 15-30 million electron volts, the capability of extracting two beams simultaneously, low power consumption, easy maintenance. Other aspects not directly related to the principle of operation discussed include the vacuum and the radio-frequency systems as well as the complex computerized control system used to automatically control start-up and shut-down operations. ills

  5. National Medical Cyclotron

    Boyd, Rex.

    1991-01-01

    The National Medical Cyclotron, under construction at Sydney's Royal Prince Alfred Hospital(RPAH) is to be operated by the Australian Nuclear Science and Technology Organization in collaboration with the hospital. Its main purpose is to produce radioisotopes on commercial basis for distribution to hospitals through Australia as well as short-lived radioisotopes (2 minutes to 2 hours) for immediate application at RPAH in Positron Emission Tomography, to study the dynamics of human physiology and metabolism in organs, bones and soft tissues. A list of the principal cyclotron-produced radionuclides is provided. ills

  6. Ramifide resonators for cyclotrons

    Smirnov, Yu.V.

    2000-01-01

    The resonators with the conductors ramified form for cyclotrons are systematized and separated into the self-contained class - the ramified resonators for cyclotrons (Carr). The ramified resonators are compared with the quarter-wave and half-wave nonramified resonators, accomplished from the transmitting lines fragments. The CRR are classified into two types: ones with the additional structural element, switched in parallel and in series. The CRR may include several additional structural elements. The CRR calculations may be concluded by analytical methods - the method of matrix calculation or the method of telegraph equations and numerical methods - by means of the ISFEL3D, MAFIA and other programs [ru

  7. Seismic architecture of the Chalk Group from onshore reflection data in eastern Denmark

    Moreau, Julien; Anderskouv, Kresten; Boldreel, Lars Ole

    with the seismic stratigraphy. Several seismic facies are identified in the Chalk Group: the 'transparent' (white chalk), the stratified (marl-chalk alternations), the crudely stratified (flint-rich chalk) and the hummocky (bryozoan mounds). The units notably vary in thickness at a relatively small scale...... of the deformations appear to be restricted to the white chalk, whereas the stratified seismic facies are comparatively less disturbed. The origin of the structures observed in the white chalk can either be associated with the regional stress field or with differential diagenetic evolution between strata inducing...

  8. Electron-Cyclotron Waves

    Westerhof, E.

    1994-01-01

    The essential elements of the theory of electron cyclotron waves are reviewed, The two main electro-magnetic modes of propagation are identified and their dispersion and absorption properties are discussed. The importance of the use of the relativistic resonance condition is stressed.

  9. Biomedical cyclotron facility

    MacDonald, N.S.; Birdsall, R.; Takahaski, J.; McConnel, L.; Wood, R.; Wakakuwa, S.

    1976-01-01

    During the fifth year of operation the mechanical performance of the cyclotron and accessory equipment was excellent. Major items put into operation were a small computer system interfaced with Ge-Li gamma spectrometer and a pneumatic-tube system for fast delivery of short-lived radionuclides. A table is presented listing the radionuclides produced

  10. The control computer for the Chalk River electron test accelerator

    McMichael, G.E.; Fraser, J.S.; McKeown, J.

    1978-02-01

    A versatile control and data acquisition system has been developed for a modest-sized linear accelerator using mainly process I/O hardware and software. This report describes the evolution of the present system since 1972, the modifications needed to satisfy the changing requirements of the various accelerator physics experiments and the limitations of such a system in process control. (author)

  11. The Chalk River Nuclear Laboratories contingency plan -a brief description

    White, J.M.

    1982-01-01

    A brief description of the contingency plan which deals with both the on-site and off-site consequences of a serious nuclear accident is given. The off-site consequences of different size releases and the subsequent action taken by employees, radiation protection experts, municipal, Provincial and Federal authorities is described and the interaction of the various groups is discussed. (author)

  12. A light-water detritiation project at Chalk River Laboratories

    Boniface, H.A.; Castillo, I.; Everatt, A.E.; Ryland, D.K.

    2010-01-01

    The NRU reactor rod bays is a large, open pool of water that receives hundreds of fuel rods annually, each carrying a small amount of residual tritiated heavy water. The tritium concentration of the rod bays water has risen over the years, to a level that is of concern to the operations staff and to the environment. The proposed long-term solution is to reduce the rod bays tritium concentration by direct detritiation of the water. The Combined Electrolytic-Catalytic Exchange (CECE) process is well suited to the light-water detritiation problem. With a tritium-protium separation factor greater than five, a CECE detritiation process can easily achieve the eight orders of magnitude separation required to split a tritiated light-water feed into an essentially tritium-free effluent stream and a tritiated heavy water product suitable for recycling through a heavy water upgrader. This paper describes a CECE light-water detritiation process specifically designed to reduce the tritium concentration in the NRU rod bays to an acceptable level. The conceptual design of a 600 Mg/a detritiation process has been developed and is now at the stage of project review and the beginning of detailed design. (author)

  13. TASCC newsletter volume 6 no. 11

    Thomson, L.

    1992-01-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this issue is a report on Canadians at the Eurogam spectrometer, cyclotron beam report, facility report and operating record, a listing of experiments conducted

  14. Goodbye Synchro-Cyclotron

    Anon.

    1990-12-15

    On 17 December, after having seen many other physics machines come and go during its 33-year career, CERN's 600 MeV SynchroCyclotron (SC) is being shut down. Judged simply by its length (to say nothing of its quality), the research career of this machine testifies to the wisdom and imagination of the CERN pioneers who proposed it in the early 1950s.

  15. Goodbye Synchro-Cyclotron

    Anon.

    1990-01-01

    On 17 December, after having seen many other physics machines come and go during its 33-year career, CERN's 600 MeV SynchroCyclotron (SC) is being shut down. Judged simply by its length (to say nothing of its quality), the research career of this machine testifies to the wisdom and imagination of the CERN pioneers who proposed it in the early 1950s

  16. Cyclotrons in developing countries

    Vera Ruiz, Hernan

    2004-01-01

    Cyclotron accelerators are prolific sources of charged particle for the production of radionuclides and have become an essential tool in the practice of modern nuclear medicine by providing reliable radiotracers for SPECT and PET studies. In a recent survey conducted by the IAEA in 2001, the growth in the number of cyclotron facilities installed in laboratories and hospitals in developed as well as developing countries was recorded. This trend, which started in the late 70's, continues in the present time also and all indications are that it will continue in the next five to ten years. The reasons for this growth are several: technology involved has become more user or 'hospital friendly', third party reimbursement for several clinical studies based on F-18 PET radiopharmaceuticals at least in some of the advanced countries started in 1998 and above all, the clear irrefutable and demonstrable conclusion of the positive cost/benefit outcomes of PET studies in the field of oncology to a lesser degree, thus far, for cardiology and neurology. It is however recognizable that the overall financial cost of the technology, which comprises the premises to house the facility, the cyclotron accelerator, the corresponding radiochemistry and quality control equipment and the PET cameras can be nevertheless an expensive proposition that requires careful advance planning. This fact is even more relevant when the facility is planned for installation in a developing country, which, frequently, in addition to having a lack of sufficient financial resources, do have shortage of qualified human resources to efficiently run the facility. In spite of the above, it is fact that more and more public as well as private organizations in the developing countries are setting up cyclotron/PET programmes or are seriously considering the installation of such a facility

  17. Temporal variability of micro-organic contaminants in lowland chalk catchments: New insights into contaminant sources and hydrological processes.

    Manamsa, K; Lapworth, D J; Stuart, M E

    2016-10-15

    This paper explores the temporal variation of a broad suite of micro organic (MO) compounds within hydrologically linked compartments of a lowland Chalk catchment, the most important drinking water aquifer in the UK. It presents an assessment of results from relatively high frequency monitoring at a well-characterised site, including the type and concentrations of compounds detected and how they change under different hydrological conditions including exceptionally high groundwater levels and river flow conditions during 2014 and subsequent recovery. This study shows for the first time that within the Chalk groundwater there can be a greater diversity of the MOs compared to surface waters. Within the Chalk 26 different compounds were detected over the duration of the study compared to 17 in the surface water. Plasticisers (0.06-39μg/L) were found to dominate in the Chalk groundwater on 5 visits (38.4%) accounting for 14.5% of detections but contributing highest concentrations whilst other compounds dominated in the surface water. Trichloroethene and atrazine were among the most frequently detected compounds. The limit for the total pesticide concentration detected did not exceed EU/UK prescribed concentration values for drinking water. Emerging organic compounds such as caffeine, which currently do not have water quality limits, were also detected. The low numbers of compounds found within the hyporheic zone highlight the role of this transient interface in the attenuation and breakdown of the MOs, and provision of an important ecosystem service. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.

  18. Advanced waterflooding in chalk reservoirs: Understanding of underlying mechanisms

    Zahid, Adeel; Sandersen, Sara Bülow; Stenby, Erling Halfdan

    2011-01-01

    Over the last decade, a number of studies have shown SO42−, Ca2+ and Mg2+ to be potential determining ions, which may be added to the injected brine for improving oil recovery during waterflooding in chalk reservoirs. However the understanding of the mechanism leading to an increase in oil recove...... of a microemulsion phase could be the possible reasons for the observed increase in oil recovery with sulfate ions at high temperature in chalk reservoirs besides the mechanism of the rock wettability alteration, which has been reported in most previous studies.......Over the last decade, a number of studies have shown SO42−, Ca2+ and Mg2+ to be potential determining ions, which may be added to the injected brine for improving oil recovery during waterflooding in chalk reservoirs. However the understanding of the mechanism leading to an increase in oil recovery...

  19. Startup work on Inshas cyclotron

    Vorogushin, M.F.; Strokach, A.P.; Shikhov, V.Ya.; Galchuk, A.V.; Soliman, A.N.; El-Abyad, M.; Comsan, M.N.H.; Saleh, Z.A.; Azzam, A.N.

    2001-01-01

    Startup works on the MGC-20 variable energy cyclotron in the Inshas Nuclear Research Center (Egypt) are described. The cyclotron is intended for acceleration of hydrogen and helium ions in a wide energy range (for protons - from 5 to 20 MeV). Main units of the cyclotron and results of computer experimental acceleration of protons to 18 MeV are described. The prospects of furthers investigations are presented [ru

  20. Ion cyclotron resonance heating

    Tajima, T.

    1982-01-01

    Ion cyclotron resonance heating of plasmas in tokamak and EBT configurations has been studied using 1-2/2 and 2-1/2 dimensional fully self-consistent electromagnetic particle codes. We have tested two major antenna configurations; we have also compared heating efficiencies for one and two ion species plasmas. We model a tokamak plasma with a uniform poloidal field and 1/R toroidal field on a particular q surface. Ion cyclotron waves are excited on the low field side by antennas parallel either to the poloidal direction or to the toroidal direction with different phase velocities. In 2D, minority ion heating (vsub(perpendicular)) and electron heating (vsub(parallel),vsub(perpendicular)) are observed. The exponential electron heating seems due to the decay instability. The minority heating is consistent with mode conversion of fast Alfven waves and heating by electrostatic ion cyclotron modes. Minority heating is stronger with a poloidal antenna. The strong electron heating is accompanied by toroidal current generation. In 1D, no thermal instability was observed and only strong minority heating resulted. For an EBT plasma we model it by a multiple mirror. We have tested heating efficiency with various minority concentrations, temperatures, mirror ratios, and phase velocities. In this geometry we have beach or inverse beach heating associated with the mode conversion layer perpendicular to the toroidal field. No appreciable electron heating is observed. Heating of ions is linear in time. For both tokamak and EBT slight majority heating above the collisional rate is observed due to the second harmonic heating. (author)

  1. Solid targetry for compact cyclotrons

    Comor, J.

    2004-01-01

    In this presentation authors present experimental results of solid targetry for compact cyclotrons. It is concluded: Solid targetry is not restricted to large accelerator centers anymore; Small and medium scale radioisotope production is feasible with compact cyclotrons; The availability of versatile solid target systems is expected to boost the radiochemistry of 'exotic' positron emitters

  2. Cyclotrons and positron emitting radiopharmaceuticals

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

    1984-01-01

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

  3. Status report on cyclotron operation

    Kovacs, P.; Szuecs, I.; Ander, I.; Lakatos, T.; Fenyvesi, A.; Ditroi, F.; Takacs, S.; Tarkanyi, F.

    2004-01-01

    The operation of the cyclotron in 2003 was again concentrated to 9 months; January, July and August were reserved for maintenance, renewal works and holidays. The overall working time of the accelerator was 4051 hours. The cyclotron was available for users for 3682 hours. In order to improve the circumstances of the irradiations renewal and improvements were done. (N.T.)

  4. Cyclotrons and positron emitting radiopharmaceuticals

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

    1984-01-01

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

  5. Quantitative 1D saturation profiles on chalk by NMR

    Olsen, Dan; Topp, Simon; Stensgaard, Anders

    1996-01-01

    Quantitative one-dimensional saturation profiles showing the distribution of water and oil in chalk core samples are calculated from NMR measurements utilizing a 1D CSI spectroscopy pulse sequence. Saturation profiles may be acquired under conditions of fluid flow through the sample. Results reveal...

  6. Nano sized clay detected on chalk particle surfaces

    Skovbjerg, Lone; Hassenkam, Tue; Makovicky, Emil

    2012-01-01

    that in calcite saturated water, both the polar and the nonpolar functional groups adhere to the nano sized clay particles but not to calcite. This is fundamentally important information for the development of conceptual and chemical models to explain wettability alterations in chalk reservoirs...

  7. Groundwater conversion areas in chalk in the southern Frankish Alps

    Pfaff, T.

    1987-01-01

    In order to collect hydro-geological data, chalk water marking was done and/or interpreted, water balances were produced, the contents tritium, oxygen 18, calcium, magnesium and the groundwater temperatures and electrolytic conductivity of the groundwater were examined and the dry weather drainage of individual sources was analysed. (orig./PW) [de

  8. Medical cyclotron: why, where, how

    Scheer, Kurt; Comar, Dominique; Kellershohn, Claude

    1976-01-01

    Cyclotrons for medical purposes are particularly useful for the production of radioactive isotopes of elements normally constituting organic matter ( 15 O, 13 N, 11 C). The short half-life and positron emission of those elements are of great interest in medical diagnosis. Many others carrier-free radioisotopes can be produced by cyclotrons. Three categories of cyclotrons are mentioned. Desk top cyclotron only adapted to the production of short-lived radioisotopes in a hospital; low energy and average energy cyclotrons which require well-entrained personnel for their operation and are best adapted to the production of radioelements on a regional or even national scale. Examples relative to the interest of short-lived radioisotopes in lung and brain investigations and tumor detection are given

  9. Ekofisk chalk: core measurements, stochastic reconstruction, network modeling and simulation

    Talukdar, Saifullah

    2002-07-01

    This dissertation deals with (1) experimental measurements on petrophysical, reservoir engineering and morphological properties of Ekofisk chalk, (2) numerical simulation of core flood experiments to analyze and improve relative permeability data, (3) stochastic reconstruction of chalk samples from limited morphological information, (4) extraction of pore space parameters from the reconstructed samples, development of network model using pore space information, and computation of petrophysical and reservoir engineering properties from network model, and (5) development of 2D and 3D idealized fractured reservoir models and verification of the applicability of several widely used conventional up scaling techniques in fractured reservoir simulation. Experiments have been conducted on eight Ekofisk chalk samples and porosity, absolute permeability, formation factor, and oil-water relative permeability, capillary pressure and resistivity index are measured at laboratory conditions. Mercury porosimetry data and backscatter scanning electron microscope images have also been acquired for the samples. A numerical simulation technique involving history matching of the production profiles is employed to improve the relative permeability curves and to analyze hysteresis of the Ekofisk chalk samples. The technique was found to be a powerful tool to supplement the uncertainties in experimental measurements. Porosity and correlation statistics obtained from backscatter scanning electron microscope images are used to reconstruct microstructures of chalk and particulate media. The reconstruction technique involves a simulated annealing algorithm, which can be constrained by an arbitrary number of morphological parameters. This flexibility of the algorithm is exploited to successfully reconstruct particulate media and chalk samples using more than one correlation functions. A technique based on conditional simulated annealing has been introduced for exact reproduction of vuggy

  10. JSW's baby cyclotron

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

    1983-01-01

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

  11. Cyclotron produced radiopharmaceuticals

    Kopicka, K.; Fiser, M.; Hradilek, P.; Hanc, P.; Lebeda, O.

    2003-01-01

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

  12. Field and numerical descriptions of fracture geometries and terminations in chalk containing chert layers and inclusions; implications for groundwater flow in Danish chalk aquifers

    Seyum, S.

    2017-12-01

    This study is a description of the fracture distribution in laterally discontinuous chalk and chert layers, with an investigation on how fracture lengths and apertures vary as a function of applied stresses, material properties, and interface properties. Natural fractures intersect laterally extensive, discontinuous, chalk-chert material interfaces in 62 million-year old to 72 million-year old Chalk Group formations exposed at Stevns Klint, Denmark. Approximately one-third of Denmark's fresh water use is from chalk and limestone regional aquifers of the Chalk Group formations, where rock permeability is dominantly a function of open fracture connectivities. Fractured, centimeter- to decimeter-thick chert layers and inclusions (101 GPa elastic stiffness) are interlayered with fractured, meter-thick chalk layers (100 GPa elastic stiffness). Fractures are observed to terminate against and cross chalk-chert interfaces, affecting the vertical flow of water and pollutants between aquifers. The discontinuous and variably thin nature of chert layers at Stevns Klint effectively merges adjacent fracture-confining layers of chalk along discrete position intervals, resulting in lateral variability of fracture spacing. Finite element numerical models are designed to describe fracture interactions with stiff, chert inclusions of various shapes, thicknesses, widths, orientations, and interface friction and fracture toughness values. The models are two-dimensional with isotropic, continuous material in plane strain and uniformly applied remote principal stresses. These characteristics are chosen based on interpretations of the petrophysics of chalk and chert, the burial history of the rock, and the scale of investigation near fracture tips relative to grain sizes. The result are value ranges for relative stiffness contrasts, applied stresses, and material interface conditions that would cause fractures to cross, terminate at, or form along chalk-chert interfaces, with emphasis on

  13. Applied research with cyclotrons

    Apel, P.; Dmitriev, S.; Gulbekian, G.; Gikal, B.; Ivanov, O.; Reutov, V.; Skuratov, V.

    2005-01-01

    During the past three decades the Flerov laboratory carried out research and development of a number of applications that have found or may find use in modern technologies. One of the applications is the so-called ion track technology enabling us to create micro- and nano-structured materials. Accelerated heavy ion beams are the unique tools for structuring insulating solids in a controllable manner. At FLNR JINR the U-400 cyclotron and the IC-100 cyclotron are employed for irradiation of materials to be modified by the track-etch technique. For practical applications, U-400 delivers the 86 Kr ion beams with total energies of 250, 350, 430 and 750 MeV, and the 136 Xe ion beams with the energy of 430 MeV. The cyclotron is equipped with a specialized channel for irradiation of polymer foils. IC-100 is a compact accelerator specially designed for the technological uses. High-intensity krypton ion beams with the energy of ∼ 1 MeV/u are available now at IC-100. Production of track-etch membranes is an example of mature technology based on irradiation with accelerated ions. The track-etch membranes offer distinct advantages over other types of membranes due to their precisely determined structure. One-pore, oligo-pore and multi-pore samples can serve as models for studying the transport of liquids, gases, particles, solutes, and electrolytes in narrow channels. Track-etch pores are also used as templates for making nano wires, nano tubes or array of nano rods. The microstructures obtained this way may find use in miniaturized devices such as sensors for biologically important molecules. Bulk and surface modification for the production of new composites and materials with special optical properties can be performed with ion beams. Flexible printed circuits, high-performance heat transfer modules, X-ray filters, and protective signs are examples of products developed in collaboration with research and industrial partners. Some recent achievements and promising ideas that

  14. Isochronous cyclotron data base description

    Kiyan, I.N.; Vorozhtsov, S.B.; Tarashkevich, R.

    2004-01-01

    The relational data base of the control parameters of the isochronous cyclotron, Isochronous Cyclotron Data Base (ICDB), is described. The relational data base under consideration, written in Transact SQL for the MS SQL Server 2000 with the use of MS Enterprise Manager and MS Query Analyzer, was installed on the server of the AIC144 isochronous cyclotron in Krakow, which operates under the control of the operating system MS Windows Server 2003 (Standard Edition). The interface of the data base under considerations is written in C++ with the use of Visual C++ .NET and is built in the Cyclotron Operator Help Program (COHP), which is used for modeling the operational modes of the isochronous cyclotron. Communication between the COHP and the relational data base is realised on the base of the Open Data Base Connectivity protocol. The relational data base of the control parameter of the isochronous cyclotron is intended: firstly, for systematization and automatic use of all measured and modelled magnetic field maps in the process of modeling the operational modes; secondly, for systematization and convenient access to the stored operational modes; thirdly, for simplifying the operator's work. The relational data base of the control parameter of the isochronous cyclotron reflects its physical structure and the logic of its operator's work. (author)

  15. [Cyclotron based nuclear science

    1991-08-01

    This report contains descriptions of research programs carried out by Institute staff, as well as progress on new instrumentation during the period, April 1, 1990, to March 31, 1991. The K500 cyclotron and ECR source provided beam for 4140 hours during the period. The beam was actually available for experiments 1927.50 hours and 1110.50 hours was devoted to developing new beams and exploring cyclotron performance. A wide range of beams from protons to Xe with energies from 2.4 MeV/u to 60 MeV/U have been used in experiments. The highest total energy beam accelerated was 35 MeV/u 63 Cu. The ECR source, made a tremendous improvement in accelerator performance and reliability. Substantial amounts of beam time were devoted to investigations of hot nuclei, electron-positron, giant resonances, atomic effects of high velocity ion beams, astrophysics related reactions and proton and alpha bremsstrahlung. Scientific accomplishments included determination of the heat capacity of nuclei through new insight into the level densities and establishing a lower limit for electron positron resonances a factor of ten better than previous measurements. The proton spectrometer, constructed for studies of the Gamow-Teller interaction is complete, and initial physics measurements will be made in the next few months. All of the BaF 2 crystals have been delivered and acceptance tests are underway. A K=315 MDM spectrometer has been obtained from Oxford University and is scheduled for installation in Spring 1992, after removal of the K=150 Enge split pole spectrometer. Institute groups continue participation in MEGA, instrumentation projects for RHIC, and few nucleon studies at LAMPF and KEK. Reports of these activities are included

  16. Modelling flow and heat transfer through unsaturated chalk - Validation with experimental data from the ground surface to the aquifer

    Thiéry, Dominique; Amraoui, Nadia; Noyer, Marie-Luce

    2018-01-01

    During the winter and spring of 2000-2001, large floods occurred in northern France (Somme River Basin) and southern England (Patcham area of Brighton) in valleys that are developed on Chalk outcrops. The floods durations were particularly long (more than 3 months in the Somme Basin) and caused significant damage in both countries. To improve the understanding of groundwater flooding in Chalk catchments, an experimental site was set up in the Hallue basin, which is located in the Somme River Basin (France). Unsaturated fractured chalk formation overlying the Chalk aquifer was monitored to understand its reaction to long and heavy rainfall events when it reaches a near saturation state. The water content and soil temperature were monitored to a depth of 8 m, and the matrix pressure was monitored down to the water table, 26.5 m below ground level. The monitoring extended over a 2.5-year period (2006-2008) under natural conditions and during two periods when heavy, artificial infiltration was induced. The objective of the paper is to describe a vertical numerical flow model based on Richards' equation using these data that was developed to simulate infiltrating rainwater flow from the ground surface to the saturated aquifer. The MARTHE computer code, which models the unsaturated-saturated continuum, was adapted to reproduce the monitored high saturation periods. Composite constitutive functions (hydraulic conductivity-saturation and pressure-saturation) that integrate the increase in hydraulic conductivity near saturation and extra available porosity resulting from fractures were introduced into the code. Using these composite constitutive functions, the model was able to accurately simulate the water contents and pressures at all depths over the entire monitored period, including the infiltration tests. The soil temperature was also accurately simulated at all depths, except during the infiltrations tests, which contributes to the model validation. The model was used

  17. Ion Cyclotron Resonance Facility (ICR)

    Federal Laboratory Consortium — his facility is charged with developing and exploiting the unique capabilities of Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry, and leads the...

  18. Present and future superconducting cyclotrons

    Nolen, J.A. Jr.

    1987-01-01

    This paper begins with a brief review of the status of present superconducting (SC) cyclotron projects, including the two which are currently operating and the six which are under construction. The next section summarizes the main features shared by five of these machines, while the third section presents recent developments and new concepts introduced in the other three ''second generation'' SC cyclotrons. Projects in early stages of development are discussed in the fourth section

  19. The Effect of Bacteria Penetration on Chalk Permeability

    Halim, Amalia Yunita; Shapiro, Alexander; Nielsen, Sidsel Marie

    number of B. licheniformis was detected on the effluent compared with P. putida. However, in the experiment with B. licheniformis mainly spores were detected in the effluent. The core permeability decreased rapidly during injection of bacteria and a starvation period of 12 days did not allow......Bacteria selective plugging is one of the mechanisms through which microorganisms can be applied for enhanced oil recovery. Bacteria can plug the water-bearing zones of a reservoir, thus altering the flow paths and improving sweep efficiency. It is known that the bacteria can penetrate deeply...... into reservoirs, however, a complete understanding of the penetration behavior of bacteria is lacking, especially in chalk formations where the pore throat sizes are almost comparable with the sizes of bacteria vegetative cells. This study investigates the penetration of bacteria into chalk. Two bacteria types...

  20. Injection and extraction for cyclotrons

    Heikkinen, P.

    1994-01-01

    External ion sources for cyclotrons are needed for polarised and heavy ions. This calls for injection systems, either radial or axial. Radial injection is also needed when a cyclotron works as a booster after another cyclotron or a linear accelerator (usually tandem). Requirements for injection differ from separated sector cyclotrons where there is plenty of room to house inflectors and/or strippers, to superconducting cyclotrons where the space is limited by a small magnet gap, and high magnetic field puts other limitations to the inflectors. Several extraction schemes are used in cyclotrons. Stripping injection is used for H - and also for heavy ions where the q/m ratio is usually doubled. For other cases, electric and magnetic deflection has to be used. To increase the turn separation before the first deflector, both resonant and non-resonant schemes are used. In this lecture, external injection systems are surveyed and some rules to thumb for injection parameters are given. Extraction schemes are also reviewed. (orig.)

  1. The transport and behaviour of isoproturon in unsaturated chalk cores

    Besien, T. J.; Williams, R. J.; Johnson, A. C.

    2000-04-01

    A batch sorption study, a microcosm degradation study, and two separate column leaching studies were used to investigate the transport and fate of isoproturon in unsaturated chalk. The column leaching studies used undisturbed core material obtained from the field by dry percussion drilling. Each column leaching study used 25 cm long, 10 cm wide unsaturated chalk cores through which a pulse of isoproturon and bromide was eluted. The cores were set-up to simulate conditions in the unsaturated zone of the UK Chalk aquifer by applying a suction of 1 kPa (0.1 m H 2O) to the base of each column, and eluting at a rate corresponding to an average recharge rate through the unsaturated Chalk. A dye tracer indicated that the flow was through the matrix under these conditions. The results from the first column study showed high recovery rates for both isoproturon (73-92%) and bromide (93-96%), and that isoproturon was retarded by a factor of about 1.23 relative to bromide. In the second column study, two of the four columns were eluted with non-sterile groundwater in place of the sterile groundwater used on all other columns, and this study showed high recovery rates for bromide (85-92%) and lower recovery rates for isoproturon (66-79% — sterile groundwater, 48-61% — non-sterile groundwater). The enhanced degradation in the columns eluted with non-sterile groundwater indicated that groundwater microorganisms had increased the degradation rate within these columns. Overall, the reduced isoproturon recovery in the second column study was attributed to increased microbial degradation as a result of the longer study duration (162 vs. 105 days). The breakthrough curves (BTCs) for bromide had a characteristic convection-dispersion shape and were accurately simulated with the minimum of calibration using a simple convection-dispersion model (LEACHP). However, the isoproturon BTCs had an unusual shape and could not be accurately simulated.

  2. Low field NMR surface relaxivity studies of chalk and argillaceous sandstones

    Katika, Konstantina; Fordsmand, Henrik; Fabricius, Ida Lykke

    2017-01-01

    the accuracy of predictions of petrophysical properties of various rocks with the use of NMR spectrometry. We perform laboratory transverse relaxation (T2) measurements on water saturated Gorm field chalk, Stevns Klint chalk, Solsort field greensand and Berea sandstone. These rocks are of particular interest...... field chalk and Solsort field greensand have higher ρ at higher Larmor frequency. By contrast, ρ of the purely calcitic Stevns chalk and quartzitic Berea sandstone proved not to be affected by the changes in frequency. T2 distributions at temperatures ranging from 10 °C to 60 °C provided comparison...

  3. Multicavity proton cyclotron accelerator

    J. L. Hirshfield

    2002-08-01

    Full Text Available A mechanism for acceleration of protons is described, in which energy gain occurs near cyclotron resonance as protons drift through a sequence of rotating-mode TE_{111} cylindrical cavities in a strong nearly uniform axial magnetic field. Cavity resonance frequencies decrease in sequence from one another with a fixed frequency interval Δf between cavities, so that synchronism can be maintained between the rf fields and proton bunches injected at intervals of 1/Δf. An example is presented in which a 122 mA, 1 MeV proton beam is accelerated to 961 MeV using a cascade of eight cavities in an 8.1 T magnetic field, with the first cavity resonant at 120 MHz and with Δf=8 MHz. Average acceleration gradient exceeds 40 MV/m, average effective shunt impedance is 223 MΩ/m, but maximum surface field in the cavities does not exceed 7.2 MV/m. These features occur because protons make many orbital turns in each cavity and thus experience acceleration from each cavity field many times. Longitudinal and transverse stability appear to be intrinsic properties of the acceleration mechanism, and an example to illustrate this is presented. This acceleration concept could be developed into a proton accelerator for a high-power neutron spallation source, such as that required for transmutation of nuclear waste or driving a subcritical fission burner, provided a number of significant practical issues can be addressed.

  4. Tachyonic cyclotron radiation

    Tomaschitz, R.

    2006-01-01

    We study superluminal cyclotron emission by electrons and muons in semiclassical orbits. The tachyonic line spectra of hydrogenic ions such as H, 56 Fe 25+ , and 238 U 91+ , as well as their muonic counterparts pμ - , 56 Fe 26+ μ - and 238 U 92+ μ - are calculated, in particular the tachyonic power transversally and longitudinally radiated, the total intensity, and the power radiated in the individual harmonics. We also investigate tachyonic continuum radiation from electrons and protons cycling in the surface and light cylinder fields of γ -ray and millisecond pulsars, such as the Crab pulsar, PSR B1509-58, and PSR J0218 + 4232. The superluminal spectral densities generated by non-relativistic, mildly relativistic and ultra-relativistic source particles are derived. We study the parameters determining the global shape of the transversal and longitudinal densities and the energy scales of the broadband spectrum. The observed cutoff frequency in the γ-ray band of the pulsars is used to infer the upper edge of the orbital energy, and we conclude that electrons and nuclei cycling in the surface fields can reach energies beyond the ''ankle'' of the cosmic ray spectrum. This suggests γ-ray pulsars as sources of ultra-high energy cosmic rays. (orig.)

  5. Regional hardening of Upper Cretaceous Chalk in eastern England, UK: trace element and stable isotope patterns in the Upper Cenomanian and Turonian Chalk and their significance

    Jeans, Christopher V.; Long, Dee; Hu, Xiu-Fang; Mortimore, Rory N.

    2014-12-01

    The regional hardening of the Late Cenomanian to Early Turonian Chalk of the Northern Province of eastern England has been investigated by examining the pattern of trace elements and stable carbon and oxygen isotopes in the bulk calcite of two extensive and stratigraphically adjacent units each 4 to 5 m thick of hard chalk in Lincolnshire and Yorkshire. These units are separated by a sequence, 0.3-1.3 m thick, of variegated marls and clayey marls. Modelling of the geochemistry of the hard chalk by comparison with the Standard Louth Chalk, combined with associated petrographic and geological evidence, indicates that (1) the hardening is due to the precipitation of a calcite cement, and (2) the regional and stratigraphical patterns of geochemical variation in the cement are largely independent of each other and have been maintained by the impermeable nature of the thin sequence of the clay-rich marls that separate them. Two phases of calcite cementation are recognised. The first phase was microbially influenced and did not lithify the chalk. It took place predominantly in oxic and suboxic conditions under considerable overpressure in which the Chalk pore fluids circulated within the units, driven by variations in compaction, temperature, pore fluid pressure and local tectonics. There is evidence in central and southern Lincolnshire of the loss of Sr and Mgenriched pore fluids to the south during an early part of this phase. The second phase of calcite precipitation was associated with the loss of overpressure in probably Late Cretaceous and in Cenozoic times as the result of fault movement in the basement penetrating the overlying Chalk and damaging the seal between the two chalk units. This greatly enhanced grain pressures, resulting in grain welding and pressure dissolution, causing lithification with the development of stylolites, marl seams, and brittle fractures. Associated with this loss of overpressure was the penetration of the chalk units by allochthonous

  6. [Cyclotron based nuclear science

    1993-07-01

    The period 1 April 1992--31 March 1993 saw the initial runs of three new spectrometers, which constitute a major portion of the new detection capabilities developed for this facility. These devices are the Proton Spectrometer (PSP) (data from which are shown on the cover of this document), the Mass Achroniat Recoil Mass Spectrometer (MARS), and the Multipole Dipole Multipole (MDM) Particle Spectrometer. The ECR-K500 cyclotron combination operated 5,849 hours. The beam was on target 39% of this time. Studies of nuclear dynamics and nuclear thermodynamics using the neutron ball have come to fruition. A critical re-evaluation of the available data on the giant monopole resonance indicated that the incompressibility is not specified to a range smaller than 200--350 MeV by those data. New systematic experiments using the MDM spectrometer are now underway. The MEGA collaboration obtained the first data on the μ → eγ decay rate and determination of the Michel parameter in normal μ decay. Experiments appear to confirm the existence of monoenergetic pair peaks even for relatively low Z projectile -- Z target combinations. Studies of the (α,2α) knockout reaction indicate that this reaction may prove to be a valuable tool for determination of reaction rates of astrophysical interest. Theoretical work reported in this document ranges from nuclear structure calculations using the IBM-2 model to calculations of kaon production and the in-medium properties of the rho and phi mesons. Nuclear dynamics and exotic shapes and fragmentation modes of hot nuclei are also addressed. New measurements of x-ray emission from highly ionized ions, of molecular dissociation and of surface interactions are reported. The research is presented in nearly 50 brief summaries usually including data and references

  7. Dynamic and static elastic moduli of North Sea and deep sea chalk

    Gommesen, Lars; Fabricius, Ida Lykke

    2001-01-01

    We have established an empirical relationship between the dynamic and the static mechanical properties of North Sea and deep sea chalk for a large porosity interval with respect to porosity, effective stress history and textural composition. The chalk investigated is from the Tor and Hod Formatio...

  8. Diagenetic Variations between Upper Cretaceous Outcrop and Deeply Buried Reservoir Chalks of the North Sea Area

    Hjuler, Morten Leth; Fabricius, Ida Lykke

    2007-01-01

    -particle connections and less altered particle shapes. The non-carbonate mineralogy of outcrop chalks is dominated by quartz, occasionally opal-CT and clinoptilolite, and the clay mineral smectite. In offshore chalks quartz still dominates, opal-CT has recrystallized into submicron-size quartz crystals and smectite...

  9. Dual hydraulic behaviour of the Chalk in the Netherlands North Sea

    Verweij, H.

    2006-01-01

    Information on the sedimentary development, seismic stratigraphy and burial compaction of the Chalk Group in the Netherlands North Sea was combined with pressure data and basin modelling to investigate the hydraulic behaviour of the Chalk Group in the Central Graben and Schill Grund High. The

  10. Electron cyclotron harmonic wave acceleration

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

    1987-01-01

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

  11. Electron cyclotron harmonic wave acceleration

    Karimabadi, H.; Menyuk, C.R.; Sprangle, P.; Vlahos, L.; Salonika Univ., Greece)

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts. 31 references

  12. Present situation of 'baby cyclotron'

    Yamada, Teruo

    1981-01-01

    A ''baby cyclotron'' has been developed by the Japan Steel Works, Ltd. Its No. 1 model (proton 9.4 MeV) was delivered to the Nakano Hospital of National Sanatorium in March, 1979. It is being used successfully for the production of 11 C, 13 N and 15 O and labeled compounds. The proton or deuteron particles accelerated in the cyclotron collide on target materials. The target box, which is automatically changeable, is directly installed to the accelerating box, thereby taking the safety measures for any leaking radiation. The following matters are described: the production of short-lived radioisotopes (RI yields and treatment); the processes of production in the Nakano Hospital, with No. 1 baby cyclotron, including the photosynthesis of labeled compounds such as 11 C-labeled glucose; the research on the automation in the synthesis of organic labeled compounds like 11 C-palmitic acid. (J.P.N.)

  13. Status Report on Cyclotron Operation

    Kovacs, P.; Szuecs, I.; Ander, I.; Lakatos, T.; Tarkanyi, F.

    2004-01-01

    Complete text of publication follows. The operation of the cyclotron in 2004 was concentrated to the usual 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 3554 hours, the time used for systematic maintenance was 450 hours. The breakdown periods amounted to 70 hours last year, included in it a 50 hours repair of RF control module under guarantee. The cyclotron was available for users during 3034 hours. The effectively used beam-on-target time statistics is summarized in Table 1. Developments: A new measuring site with a HPGe detector based gamma spectrometer is under installation in the basement of the Cyclotron Laboratory. A two channel pneumatic rabbit system is also under development to enable fast transport of samples between the new measuring site and two irradiation sites (the low intensity fast neutron irradiation site and the beam line used for Thin Layer Activation). (author)

  14. Development of Medical Cyclotron in KIRAMS

    Chai, Jong Seo; Jung, In Su; An, Dong Hyun

    2005-01-01

    This paper is presented on the development and status of medical cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS) at present. We have developed medical cyclotron which is KIRAMS-13. And the improvement of KIRAMS-13 is presented. Furthermore, the design of new cyclotrons, such as KIRAMS-5 and KIRAMS-30 cyclotron, are presented, and R and D studies for future plan of heavy ion accelerator are discussed

  15. Impact of supercritical CO2 injection on petrophysical and rock mechanics properties of chalk: an experimental study on chalk from South Arne field, North Sea

    Alam, Mohammad Monzurul; Hjuler, Morten Leth; Christensen, Helle Foged

    2011-01-01

    Changes in chalk due to EOR by injecting supercritical CO2 (CO2-EOR) can ideally be predicted by applying geophysical methods designed from laboratory-determined petrophysical and rock mechanics properties. A series of petrophysical and rock mechanics tests were performed on Ekofisk Formation...... and Tor Formation chalk of the South Arne field to reveal the changes in petrophysical and rock mechanics properties of chalk due to the injection of CO2 at supercritical state. An increase in porosity and decrease in specific surface was observed due to injection of supercritical CO2. This indicates...... as indicated by NMR T2 relaxation time was observed. Rock mechanics testing indicates that in 30% porosity chalk from the South Arne field, injection of supercritical CO2 has no significant effect on shear strength and compaction properties, while there is probably a slight decrease in stiffness properties...

  16. MC-50 AVF cyclotron operation

    Chae, Jong Seo; Lee, Dong Hoon; Kim, You Seok; Park, Chan Won; Lee, Yong Min; Hong, Sung Seok; Lee, Min Yong

    1995-12-01

    The first cyclotron in Korea, MC-59 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-70 .mu.A. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed. (author). 8 tabs., 17 figs., 10 refs.

  17. MC-50 AVF cyclotron operation

    Kim, Yu Seok; Chai, Jong Seo; Bak, Seong Ki; Park, Chan Won; Jo, Young Ho; Hong, Seong Seok; Lee, Min Yong; Jang Ho Ha

    2000-01-01

    The first cyclotron in Korea, MC-50 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-60μA. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23 days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed

  18. MC-50 AVF cyclotron operation

    Kim, Yu Seok; Chai, Jong Seo; Bak, Seong Ki; Park, Chan Won; Jo, Young Ho; Hong, Seong Seok; Lee, Min Yong; Jang Ho Ha

    2000-01-01

    The first cyclotron in Korea, MC-50 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-60{mu}A. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23 days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed.

  19. The development of cyclotron radiopharmaceuticals

    Yang, Seung Dae; Chun, K. W.; Suh, Y. S.; Lee, J. D.; Ahn, S. H. and others

    1999-03-01

    The purpose of this project is to develop the radiopharmaceuticals and automatic synthetic unit for labelled compounds, and to establish mass production system of radiopharmaceuticals. These will contribute to the early diagnosis of the disease hard to cure. The contents of this project are as follows, the development of the radiopharmaceutical for imaging of cancer, the development of automatic synthesizer for the synthesis of radio-pharmaceuticals, the development of hormone derivatives labelled with 12 '3I, the development of the radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for imaging of myocardial metabolism

  20. MC-50 AVF cyclotron operation

    Chae, Jong Seo; Lee, Dong Hoon; Kim, You Seok; Park, Chan Won; Lee, Yong Min; Hong, Sung Seok; Lee, Min Yong.

    1995-12-01

    The first cyclotron in Korea, MC-59 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-70 .mu.A. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed. (author). 8 tabs., 17 figs., 10 refs

  1. Probing the intrinsically oil-wet surfaces of pores in North Sea chalk at subpore resolution

    Hassenkam, Tue; Skovbjerg, Lone Lindbæk; Stipp, Susan Louise Svane

    2009-01-01

    been drilled in a water-bearing formation. At this site, the chalk has never seen oil, though at other locations, the same stratigraphic horizon with the same rock properties is known to be a productive oil reservoir. Thus the properties of the investigated particle surfaces are inherent to the chalk......Ultimate Oil recovery from chalk reservoirs is limited by many factors - including the grain size and the surface properties of the small mainly biogenic calcite particles that chalk is made off . Wettability, the tendency for water or oil to spread over a surface, of the particle surfaces is one...... of the controlling factors for the effectiveness of water flooding, one of the most common methods to improve oil recovery in Chalk reservoirs. Understanding surface wetting and its variability at scales smaller than the pore dimension will potentially provide clues for more effective oil production methods. We used...

  2. Uranium traps in the phosphate bearing sudr chalk, in northeastern sinai, Egypt

    Hussein, H.A.; El-Aassy, I.E.; Mahdy, M.A.; Dabbour, G.A.; Mansour, M.Gh.; Morsy, A.M.

    1998-01-01

    The maastrichtian sudr formation in northeastern sinai is composed of three members, the lower chalk, the middle phosphate and chart-bearing and the upper chalk members. Lemon yellow secondary uranium mineralization, distributed in the lower chalk member and in some phosphate beds from the middle phosphate member are observed. The XRD analyses of some samples from the uranium bearing chalk and the phosphate beds showed the presence of the secondary uranium minerals carnotite, bergenite and upalite. The mode of uranium occurrences could be interpreted as a result of the phosphatic beds decomposition and their subjection to later diagenetic processes. Uranium leaching circulation from phosphate rocks led to the liberation of uranium from the phosphates, and vanadium from the bituminous material and clay minerals. These migrated and were deposited locally and within the underlying chalk beds which acted as a lithologic trap

  3. Improved Oil Recovery in Chalk. Spontaneous Imbibition affected by Wettability, Rock Framework and Interfacial Tension

    Milter, J.

    1996-12-31

    The author of this doctoral thesis aims to improve the oil recovery from fractured chalk reservoirs, i.e., maximize the area of swept zones and their displacement efficiencies. In order to identify an improved oil recovery method in chalk, it is necessary to study wettability of calcium carbonate and spontaneous imbibition potential. The thesis contains an investigation of thin films and wettability of single calcite surfaces. The results of thin film experiments are used to evaluate spontaneous imbibition experiments in different chalk types. The chalk types were described detailed enough to permit considering the influence of texture, pore size and pore throat size distributions, pore geometry, and surface roughness on wettability and spontaneous imbibition. Finally, impacts of interfacial tension by adding anionic and cationic surfactants to the imbibing water phase are studied at different wettabilities of a well known chalk material. 232 refs., 97 figs., 13 tabs.

  4. Chalk effect on PVC cross-linking under irradiation; Vliyanie mela na sshivanie PVKh pri obluchenii

    Chudinova, V V; Guzeev, V V; Mozzhukhin, V B; Pomerantseva, Eh G; Nozrina, F D; Zhil` tsov, V V; Zubov, V P

    1994-12-31

    Effect of nonmodified and modified chalk on curing degree of polymer matrix was studied under-irradiation of PVC-compositions. Films of the compositions (100 mass part 7 PVC, 0-100 mas.part of chalk, 2.5 - lead sulfate, 1.5 - lead stearate and 0.3 - glycerin) were irradiated up to absorbed dose 0.1 MGy in an inert medium. Content of gel-fraction after boiling in THF was determined with use of IR spectroscopy. It was established, that intensive dehydrochlorination and polymer curing took place on chalk particle surface. Network fixed strongly chalk particles. However, chalk inhibited processes of dehydrochlorination and PVC curing, increasing amount of noncured PVC in polymer matrix.

  5. Fault zone processes in mechanically layered mudrock and chalk

    Ferrill, David A.; Evans, Mark A.; McGinnis, Ronald N.; Morris, Alan P.; Smart, Kevin J.; Wigginton, Sarah S.; Gulliver, Kirk D. H.; Lehrmann, Daniel; de Zoeten, Erich; Sickmann, Zach

    2017-04-01

    A 1.5 km long natural cliff outcrop of nearly horizontal Eagle Ford Formation in south Texas exposes northwest and southeast dipping normal faults with displacements of 0.01-7 m cutting mudrock, chalk, limestone, and volcanic ash. These faults provide analogs for both natural and hydraulically-induced deformation in the productive Eagle Ford Formation - a major unconventional oil and gas reservoir in south Texas, U.S.A. - and other mechanically layered hydrocarbon reservoirs. Fault dips are steep to vertical through chalk and limestone beds, and moderate through mudrock and clay-rich ash, resulting in refracted fault profiles. Steeply dipping fault segments contain rhombohedral calcite veins that cross the fault zone obliquely, parallel to shear segments in mudrock. The vertical dimensions of the calcite veins correspond to the thickness of offset competent beds with which they are contiguous, and the slip parallel dimension is proportional to fault displacement. Failure surface characteristics, including mixed tensile and shear segments, indicate hybrid failure in chalk and limestone, whereas shear failure predominates in mudrock and ash beds - these changes in failure mode contribute to variation in fault dip. Slip on the shear segments caused dilation of the steeper hybrid segments. Tabular sheets of calcite grew by repeated fault slip, dilation, and cementation. Fluid inclusion and stable isotope geochemistry analyses of fault zone cements indicate episodic reactivation at 1.4-4.2 km depths. The results of these analyses document a dramatic bed-scale lithologic control on fault zone architecture that is directly relevant to the development of porosity and permeability anisotropy along faults.

  6. Groundwater recharge dynamics in unsaturated fractured chalk: a case study

    Cherubini, Claudia; Pastore, Nicola; Giasi, Concetta I.; Allegretti, Nicolaetta M.

    2016-04-01

    The heterogeneity of the unsaturated zone controls its hydraulic response to rainfall and the extent to which pollutants are delayed or attenuated before reaching groundwater. It plays therefore a very important role in the recharge of aquifers and the transfer of pollutants because of the presence of temporary storage zones and preferential flows. A better knowledge of the physical processes in the unsaturated zone would allow an improved assessment of the natural recharge in a heterogeneous aquifer and of its vulnerability to surface-applied pollution. The case study regards the role of the thick unsaturated zone of the Cretaceous chalk aquifer in Picardy (North of France) that controls the hydraulic response to rainfall. In the North Paris Basin, much of the recharge must pass through a regional chalk bed that is composed of a porous matrix with embedded fractures. Different types of conceptual models have been formulated to explain infiltration and recharge processes in the unsaturated fractured rock. The present study analyses the episodic recharge in fractured Chalk aquifer using the kinematic diffusion theory to predict water table fluctuation in response to rainfall. From an analysis of the data, there is the evidence of 1) a seasonal behavior characterized by a constant increase in the water level during the winter/spring period and a recession period, 2) a series of episodic behaviors during the summer/autumn. Kinematic diffusion models are useful for predict preferential fluxes and dynamic conditions. The presented approach conceptualizes the unsaturated flow as a combination of 1) diffusive flow refers to the idealized portion of the pore space of the medium within the flow rate is driven essentially by local gradient of potential; 2) preferential flow by which water moves across macroscopic distances through conduits of macropore length.

  7. Geochemical criteria for reservoir quality variations in chalk from the North Sea

    Kunzendorf, H.; Soerensen, P.

    1989-12-01

    The influence of chalk geochemistry on petrophysical parameters determining porosity and permeability is investigated. The central well TWB-8 and eastern marginal well E-lx of the North Sea Tyra gas field were chosen. Drill core sections of Upper Maastrichtian and Danian chalk were selected. Chemical data on chalk samples were gathered by using X-ray fluorescence and instrumental neutron activation. Geochemical data are compared with the well-logging results. Geophysical logging suggests that there is reduced porosity in the Danian reservoir units LDP and UDT in both wells. The chalk drill core samples from the section with reduced porosity also show a lower Ca content. A high Si content is observed in these samples and a number of trace elements in chalk show a similar distribution with depth. Reservoir porosity may be estimated from the Si content of chalk. Chalk permeability may also be elements Al, Fe and Sc show the same trends as that for Si. Diagenetic changes in chalk also include clay minerals. The gas zone in TWB-8 is characterized by low contents of Na and Cl, i.e. lower water saturation is indicated. Low concentrations of rare earths in all chalk samples show a shale-normalized pattern that is characteristic of marine sediments laid down under oxic conditions. Some changes that occur with depth in the Ce anomaly may indicate a slight change in the depositional environment. The content of manganese continuously decreases with depth, from Danian (about 2000 ppm) to Maastrichtian strata (less than 200 ppm). In this respect, no other chemical element in chalk correlates with Mn. There is no indication as to which mineral or mineral phase one is likely to find in the element. (AB) 14 tabs., 49 ills., 147 refs

  8. Fluid substitution studies for North Sea chalk logging data

    Gommesen, Lars; Mavko, G.; Mukerji, T.

    2002-01-01

    We have tested the application of respectively the Kuster-Toksöz and the Gassmann theory as a tool for predicting pore fluid from the elastic properties of brine-saturated North Sea reservoir chalk. We confirm that the Kuster-Toksöz model predicts a larger fluid effect thant the Gassmann model......, and show that the Kuster-Toksöz model fails to predict the presence of hydrocarbons. The Gassmann prediction for the near and potentially invaded zone corresponds more closely to logging data, than the Gassmann prediction for the far, virgin zone. We hereby conclude that the Gassmann theory predicts...

  9. Princeton Cyclotron QDDD spectrograph system

    Kouzes, R.T.

    1985-01-01

    A review of experiments involving the Princeton Quadrupole-Dipole-Dipole- Dipole (QDDD) spectrograph is given. The QDDD is a high resolution, large solid angle device which is combined with the azymuthally varying field (AVF) cyclotron. Some reactions involving 3 He beams are discussed

  10. PIXE analysis by baby cyclotron

    Yoshida, Hyogo; Tanaka, Teruaki; Ito, Takashi; Toda, Yohjiro; Wakasa, Hideichiro

    1988-01-01

    The Japan Steel Works, Ltd. has been supplying a very small sized cyclotron (Baby Cyclotron) to hospitals and research facilities. The cyclotron is designed to produce short-lived radioisotopes for medical use. In the present study, this cyclotron is modified so that it can serve for PIXE analysis. The PIXE (particle induced X-ray emission) technique has the following features: (1) Down to 1 ng of trace material in a sample (mg - μg) can be detected, (2) An analysis run is completed in one to ten minutes, permitting economical analysis for a large number of samples, (3) Several elements can be analyzed simultaneously, with an almost constant sensitivity for a variety of elements ranging from aluminum to heavy metals, (4) Analysis can be performed nondestructively without a chemical process, and (5) The use of microbeam can provide data on the distribution of elements with a resolution of several μm. Software for analysis is developed to allow the modified equipment to perform peak search, background fitting, and identification and determination of peaks. A study is now being conducted to examine the performance of the equipment for PIXE analysis of thin samples. Satisfactory results have been obtained. The analysis time, excluding the background correction, is 5-10 min. (Nogami, K.)

  11. Ion sources for cyclotron applications

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

    1992-07-01

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

  12. Ponderomotive force near cyclotron resonance

    Kono, Mitsuo; Sanuki, Heiji

    1987-01-01

    The ponderomotive force, which is involved in the excitation of macroscopic behaviors of plasma caused by wave motion, plays an important role in various non-linear wave motion phenomena. In the present study, equations for the pondermotive force for plasma in a uniform magnetic field is derived using a renormalization theory which is based on the Vlasov equation. It is shown that the pondermotive force, which diverges at the cyclotron resonence point according to adiabatic approximation, can be expressed by a non-divergent equation by taking into account the instability of the cyclotron orbit due to high-order scattering caused by a wave. This is related with chaotic particle behaviors near cyclotron resonance, where the pondermotive force is small and the diffusion process prevails. It is assumed here that the amplitude of the high-frequency electric field is not large and that the broadening of cyclotron levels is smaller than the distance between the levels. A global chaos will be created if the amplitude of the electric field becomes greater to allow the broadening to exceed the distance between the levels. (Nogami, K.).

  13. Cyclotron transitions of bound ions

    Bezchastnov, Victor G.; Pavlov, George G.

    2017-06-01

    A charged particle in a magnetic field possesses discrete energy levels associated with particle rotation around the field lines. The radiative transitions between these levels are the well-known cyclotron transitions. We show that a bound complex of particles with a nonzero net charge displays analogous transitions between the states of confined motion of the entire complex in the field. The latter bound-ion cyclotron transitions are affected by a coupling between the collective and internal motions of the complex and, as a result, differ from the transitions of a "reference" bare ion with the same mass and charge. We analyze the cyclotron transitions for complex ions by including the coupling within a rigorous quantum approach. Particular attention is paid to comparison of the transition energies and oscillator strengths to those of the bare ion. Selection rules based on integrals of collective motion are derived for the bound-ion cyclotron transitions analytically, and the perturbation and coupled-channel approaches are developed to study the transitions quantitatively. Representative examples are considered and discussed for positive and negative atomic and cluster ions.

  14. Status report on cyclotron operation

    Kovács, P; Ander, I; Lakatos, T; Fenyvesi, A; Ditrói, F; Takács, S; Tarkanyi, F

    2003-01-01

    The operation of the cyclotron in 2002 was concentrated to 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 4084 hours, the breakdown periods amounted to 15 hours last year. In order to improve the circumstances of the irradiations, several following improvements were done. (R.P.)

  15. Chalk porosity and sonic velocity versus burial depth

    Fabricius, Ida Lykke; Gommesen, Lars; Krogsbøll, Anette Susanne

    2008-01-01

    Seventy chalk samples from four formations in the overpressured Danish central North Sea have been analyzed to investigate how correlations of porosity and sonic velocity with burial depth are affected by varying mineralogy, fluid pressure, and early introduction of petroleum. The results show th...... for fluid pressure because the cementing ions originate from stylolites, which are mechanically similar to fractures. We find that cementation occurs over a relatively short depth interval.......Seventy chalk samples from four formations in the overpressured Danish central North Sea have been analyzed to investigate how correlations of porosity and sonic velocity with burial depth are affected by varying mineralogy, fluid pressure, and early introduction of petroleum. The results show...... that porosity and sonic velocity follow the most consistent depth trends when fluid pressure and pore-volume compressibility are considered. Quartz content up to 10% has no marked effect, but more than 5% clay causes lower porosity and velocity. The mineralogical effect differs between P-wave and shear velocity...

  16. Savannah River Laboratory contribution to the Chalk River experimental HT release of June 1987

    Murphy, C.E. Jr.

    1987-01-01

    Seventeen years ago, a series of experiments were conducted at Bruyeres-Le-Chatel by French scientists interested in atmospheric diffusion. The scientists used tritium as a tracer in these tests. The results showed nearly complete oxidation of the gas by the time the released material had been carried 10 kilometers from the source. It became clear that if the results were general, the doses projected for fusion reactors would be greatly increased over what had been expected from earlier experience with HT gas. For this reason, the Next European Torus (NET) fusion program funded a series of experiments to look further at tritium oxidation in the environment. SRL participation in the tests provided an opportunity to make field comparisons of the SRL design tritium gas samplers and also provided vegetation that had been exposed under controlled conditions which could be used to study the incorporation of tritium into vegetation organics, the subject of ongoing SRL research. 25 refs., 4 figs., 2 tabs

  17. TASCC newsletter volume 10 no. 1

    Thomson, L.

    1996-01-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this January issue of TASCC is an update of the facility, letters of support to the government for research to continue at Chalk River Laboratories, home page on the Internet, collaboration on Vsystem with the Hahn-Meitner Institute and a listing of January's experiments. 1 fig

  18. Progress report, Physics Division, July 1 to September 30, 1976

    1976-10-01

    Progress in the Physics Division, Chalk River Nuclear Laboratories, is reported for the period July 1 to September 30, 1976. Operation of the MP Tandem accelerator is described. Design highlights are provided for a proposed superconcucting cyclotron. Elastic and inelastic scattering experiments, many conducted in cooperation with other laboratories, are summarized. Activities of the Chalk River computation centre are also described. (O.T.)

  19. From ooze to sedimentary rock, the first diagenetic processes affecting the chalk of eastern Denmark

    Moreau, Julien; Boussaha, Myriam; Nielsen, Lars

    processes operating in the chalk sediments at widely different scales into a single diagenetic model: At Stevns the chalk is affected by an extensive polygonal fault system which is expressed in onshore and offshore seismic profiles. Smaller scale contractional features like deformation bands (hairline...... strongly affect reservoir properties of the chalk both by establishing compartments and vertical connections. A better understanding of these reservoir modifications will be critical for improving the predictive capability of models describing the behaviour of drinking water and hydrocarbons hosted...

  20. Development of cyclotron solid targetry

    D'Souza, J.; Deans, T.; Cryer, D.; Price, R.

    2004-01-01

    Full text: Western Australia's first medical cyclotron was recently installed in the Department of Medical Technology and Physics at Sir Charles Gairdner Hospital. The cyclotron is routinely used for 18 F production using a liquid target, and now research is being undertaken into solid target bombardment for production of novel isotopes such as 124 I, 64 Cu and 96 Tc. The IBA Cyclone 18/9 has a maximum proton beam energy of 18MeV and maximum beam current of 80μA. A proton beam is generated by the acceleration of H- ions in the evacuated cyclotron (10 -6 bar) which are then stripped of 2 electrons just prior to exiting a target port. Each port has two strippers which are made of 10μm thick carbon with dimensions 12mmxl3mm. Due to their thinness, the strippers are easily ruptured. The Cyclone 18/9 has 8 target ports. In order to fit a target onto the cyclotron when the cyclotron is already evacuated the target is first evacuated to 10 -3 bar by a roughing pump before an isolation valve at the port is opened. This stops any damage that may occur by the flow of air from the target reservoir to the cyclotron eg to the strippers. The first step in the project to develop solid targetry is to build a beam line in order to measure the beam profile. If successful, this design will be improved in order to have a beam line and target holder that are suitable for use in solid target bombardment. A 40cm beam line with an internal diameter of 3.6cm was built to fit onto the IBA Cyclone 18/9. The beam line, made out of aluminium, incorporates a step 5cm from the end at which a target material can be fitted. A cover fits onto the beam line, behind the target in order to maintain vacuum. The cover is held in place by the vacuum within the beam line. At the end of bombardment, the beam line can be isolated from the vacuum of the target and normal air pressure restored. In doing so the cover plate falls open and the target falls into a lead pot, ready for removal from the cyclotron

  1. Identifying evidence of climate change impact on extreme events in permeable chalk catchments

    Butler, A. P.; Nubert, S.

    2009-12-01

    The permeable chalk catchments of southern England are vital for the economy and well being of the UK. Not only important as a water resource, their freely draining soils support intensive agricultural production, and the rolling downs and chalk streams provide important habitants for many protected plant and animal species. Consequently, there are concerns about the potential impact of climate change on such catchments, particularly in relation to groundwater recharge. Of major concern are possible changes in extreme events, such as groundwater floods and droughts, as any increase in the frequency and/or severity of these has important consequences for water resources, ecological systems and local infrastructure. Studies of climate change impact on extreme events for such catchments have indicated that, under medium and high emissions scenarios, droughts are likely to become more severe whilst floods less so. However, given the uncertainties in such predictions and the inherent variability in historic data, producing definitive evidence of changes in flood/drought frequency/severity poses a significant challenge. Thus, there is a need for specific extreme event statistics that can be used as indicators of actual climate change in streamflow and groundwater level observations. Identifying such indicators that are sufficiently robust requires catchments with long historic time series data. One such catchment is the River Lavant, an intermittent chalk stream in West Sussex, UK. Located within this catchment is Chilgrove House, the site of the UK’s longest groundwater monitoring well (with a continuous record of water level observations of varying frequency dating back to 1836). Using a variety of meteorological datasets, the behaviour of the catchment has been modelled, from 1855 to present, using a 'leaky aquifer' conceptual model. Model calibration was based on observed daily streamflow, at a gauging station just outside the town of Chichester, from 1970. Long

  2. Neutron radiography with the cyclotron

    Tazawa, Shuichi; Asada, Yorihisa; Yano, Munehiko; Nakanii, Takehiko.

    1985-01-01

    Neutron radiography is well recognized as a powerful tool in nondestructive testing, but not widely used yet owing to lack of high intense thermal neutron source convenient for practical use. This article presents a new neutron radiograph facility, utilizing a sub-compact cyclotron as neutron source and is equipped with vertical and horizontal irradiation ports. The article describes a series of experiments, we conducted using beams of a variable energy cyclotron at Tohoku University to investigate the characteristics of thermal neutron obtained from 9 Be(p, n) reaction and thermalized by elastic scattering process. The article also describes a computer simulation of neutron moderator to analyze conditions getting maximal thermal neutron flux. Further, some of practical neutron radiograph examinations of aero-space components and museum art objects of classic bronze mirror and an attempt realizing real time imaging technique, are introduced in the article. (author)

  3. The development of cyclotron radiopharmaceuticals

    Yang, Seung Dae; Chun, K. W.; Suh, Y. S.; Lee, J. D.; Ahn, S. H. and others

    1999-03-01

    The purpose of this project is to developthe radiopharmaceuticals and automatic synthetic unit for labelled compounds, and to establish mass production system of radiopharmaceuticals. These will contribute to the early diagnosis of the disease hard to cure. The contents of this project are as follows, the development of the radiopharmaceutical for imaging of cancer, the development of automatic synthesizer for the synthesis of radio-pharmaceuticals, the development of hormone derivatives labelled with {sup 12}'3I, the development of the radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for imaging of myocardial metabolism.

  4. Cyclotron radiation from hot plasmas

    Pohl, F.; Henning, J.; Duechs, D.

    1975-11-01

    In calculating the energy transport and losses due to cyclotron radiation there are two major requirements: the absorption coefficient has to be known and the proper geometry of the plasma has to be taken into account. In this report Trubnikov's integral formulae for the absorption coefficient have been evaluated numerically and compared with the approximative formulas of previous authors. Deviations by a factor of 2 - 10 in various frequency regimes are not unusual. With these coefficients the rate of change of the energy density due to cyclotron radiation in a plasma as well as the radiation density at a plasma surface are computed for plasma slab and plasma cylinder. Sometimes considerable differences to the results of previons papers can found. Many simple formulae interpolating the numerical results are given in the text, and the FORTRAN computer programs have been reproduced in the appendices. (orig.) [de

  5. Cyclotron production of Cu-61

    Lebeda, Ondřej; Ráliš, Jan; Seifert, Daniel

    2013-01-01

    Roč. 40, 2 Supplement (2013), S323-S323 ISSN 1619-7070. [Annual Congress of the European Association of Nuclear Medicine (EANM). 19.10.2013-23.10.2013, Lyon] R&D Projects: GA TA ČR TA02010797 Institutional support: RVO:61389005 Keywords : cyclotron U-120M * PET * Cu-61 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  6. Status report on the cyclotron

    Kormany, Z.

    2002-01-01

    Complete text of publication follows. The operation of the cyclotron in 2001 was again concentrated to the usual 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 4300 hours, the breakdown periods amounted to 66 hours last year. The cyclotron was available for users during 3751 hours, the effectively used beam-on-target time is summarized in Table 1. The total time required for machine setup and beam tuning or spent waiting for the start of an irradiation was 272 hours. The control of the adjustable collimators applied in the beam transport system of the cyclotron was renewed during the winter maintenance period. They have been connected to the programmable logic controllers (PLC) and their new control code frees the operators from the long and slow manual setting process. The successful renewal of the control of this and other subsystems (cyclotron and beam transport power supplies) made lots of adjusting and measuring elements on the original control desk needless. To provide more space for the control PCs and remove all unnecessary devices, the unused part of the control desk has been dismantled. The short beam line used mainly for radiation hardness studies was equipped with a new oil-diffusion vacuum system during the summer maintenance. Its components are also connected to the PLC and the same automatic control has been provided like for the other vacuum stands of- the beam transport system. Another short beam line - basically a mirror image of the first one - has also been installed and successfully tested by trial irradiations. (R.P.)

  7. Commercial compact cyclotrons in the 90's

    Milton, B.F.

    1995-09-01

    Cyclotrons continue to be efficient accelerators for radio-isotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicate a strong future for commercial cyclotrons. In this paper we 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. We will also discuss the possibility of systems designed for higher energies and capable of extracted beam currents of up to 2.0 mA. (author)

  8. Commercial compact cyclotrons in the 90's

    Milton, B.F.

    1995-09-01

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

  9. Method and apparatus for ion cyclotron spectrometry

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

    2010-08-17

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

  10. Future cyclotron systems : an industrial perspective

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

    1995-09-01

    The use of commercial cyclotron systems for the production of radioisotopes continues to grow on a world-wide scale. Improvements in technology have significantly increased the production capabilities of modem 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, we 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. (author)

  11. Future cyclotron systems: An industrial perspective

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

    1995-09-01

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

  12. Stylolites, porosity, depositional texture, and silicates in chalk facies sediments

    Fabricius, Ida Lykke; Borre, Mai K.

    2007-01-01

    dissolution around 490 m below sea floor (bsf) corresponds to an interval of waning porosity-decline, and even the occurrence of proper stylolites from 830 m bsf is accompanied by only minor porosity reduction. Because opal is present, the pore-water is relatively rich in Si which through the formation of Ca......-silica complexes causes an apparent super-saturation of Ca and retards cementation. The onset of massive pore-filling cementation at 1100 m bsf may be controlled by the temperature-dependent transition from opal-CT to quartz. In the stylolite-bearing chalk of two wells in the Gorm and Tyra fields, the nannofossil...... matrix shows recrystallization but only minor pore-filling cement, whereas microfossils are cemented. Cementation in Gorm and Tyra is thus partial and has apparently not been retarded by opal-controlled pore-water. A possible explanation is that, due to the relatively high temperature, silica has...

  13. Biot Critical Frequency Applied as Common Friction Factor for Chalk with Different Pore Fluids and Temperatures

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    2010-01-01

    Injection of water into chalk hydrocarbon reservoirs has lead to mechanical yield and failure. Laboratory experiments on chalk samples correspondingly show that the mechanical properties of porous chalk depend on pore fluid and temperature. Water has a significant softening effect on elastic...... and we propose that the fluid effect on mechanical properties of highly porous chalk may be the result of liquid‐solid friction. Applying a different strain or stress rate is influencing the rock strength and needs to be included. The resulting function is shown to relate to the material dependent...... and rate independent b-factor used when describing the time dependent mechanical properties of soft rock or soils. As a consequence it is then possible to further characterize the material constant from the porosity and permeability of the rock as well as from pore fluid density and viscosity which...

  14. A new cyclotron for biomedical research

    Wolber, G.

    1988-01-01

    This paper presents the rationale for replacing the old AEG Compact Cyclotron (built in 1969/71) of the Institute for Radiology and Pathophysiology at the German Cancer Research Center by a 30 MeV H - /15 MeV D - cyclotron. A status report is followed by the scientific and technical reasoning as well as budgetary and organizational considerations. In the appendix we tried to explain the function of a cyclotron in a simple and comprehensive manner. (orig.) [de

  15. Imaging the Danish Chalk Group with high resolution, 3-component seismics

    Kammann, J.; Rasmussen, S. L.; Nielsen, L.; Malehmir, A.; Stemmerik, L.

    2016-12-01

    The Chalk Group in the Danish Basin forms important reservoirs to hydrocarbons as well as water resources, and it has been subject to several seismic studies to determine e.g. structural elements, deposition and burial history. This study focuses on the high quality seismic response of a survey acquired with an accelerated 45 kg weight drop and 3-component MEMS-based sensors and additional wireless vertical-type sensors. The 500 m long profile was acquired during one day close to a chalk quarry and chalk cliffs of the Stevns peninsula in eastern Denmark where the well-known K-T (Cretaceous-Tertiary) boundary and different chalk lithologies are well-exposed. With this simple and fast procedure we were able to achieve deep P-wave penetration to the base of the Chalk Group at about 900 m depth. Additionally, the CMP-processed seismic image of the vertical component stands out by its high resolution. Sedimentary features are imaged in the near-surface Danian, as well as in the deeper Maastrichtian and Upper Campanian parts of the Chalk Group. Integration with borehole data suggests that changes in composition, in particular clay content, correlate with changes in reflectivity of the seismic data set. While the pure chalk in the Maastrichtian deposits shows rather low reflectivity, succession enriched in clay appear to be more reflective. The integration of the mentioned methods gives the opportunity to connect changes in facies to the elastic response of the Chalk Group in its natural environmental conditions.

  16. Advances in superconducting cyclotrons at MSU

    Blosser, H.; Antaya, T.; Au, R.

    1987-01-01

    Intensive work on superconducting cyclotrons began at MSU in late 1973 (a brief earlier study had occurred in the early 1960's) and continues vigorously at present. One large cyclotron, the ''K500'', has been operating for a number of years, a second, the ''K800'', is nearing completion, the first operating tests of its magnet having occurred at the time of the previous conference, and a third, the ''medical cyclotron'', is now also nearing completion with first operation of its magnet expected just after the present conference. These cyclotrons like other superconducting cyclotrons are all dramatically smaller than comparable room temperature machines; overall weight is typically about 1/20th of that of room temperature cyclotrons of the same energy. This large reduction in the quantities of materials is partially offset by added complexity, but finally, a net overall cost savings of 50 to 70 % typically results; as a consequence the superconducting cyclotron is widely viewed as the cyclotron of the future. The thirteen years of experience at MSU involving three of these cyclotrons, together with much important work at other laboratories, gives a rather clear view of the advantages and disadvantages of various design approaches including by now a rather significant period of long term evaluation. This paper reviews highlights of this program. (author)

  17. TASCC newsletter volume 9 no. 6

    Thomson, L.

    1995-06-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this June issue of TASCC is an update of the facility, TASCC workshop on international success and a listing of Junes's experiments. 1 fig

  18. TASCC newsletter volume 5 no. 5

    Thomson, L.

    1991-05-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this May issue is information on a workshop for material science studies, a facility report and operating record and the experiments conducted. 1 fig

  19. TASCC newsletter volume 6 no. 6

    Thomson, L.

    1992-06-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this June issue is a report on operator training, operating record and facility report and a listing of experiments conducted in June

  20. The effect of chalk on the finger-hold friction coefficient in rock climbing.

    Amca, Arif Mithat; Vigouroux, Laurent; Aritan, Serdar; Berton, Eric

    2012-11-01

    The main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were performed. Participants hung from holds which were fixed on a specially designed hang board. The inclination of the hang board was progressively increased until the climber's hand slipped from the holds. The angle of the hang board was simultaneously recorded by using a gyroscopic sensor and the friction coefficient was calculated at the moment of slip. The results showed that there was a significant positive effect of chalk on the coefficient of friction (+18.7% on limestone and +21.6% on sandstone). Moreover sandstone had a higher coefficient of friction than limestone (+15.6% without chalk, +18.4% with chalk). These results confirmed climbers' belief that chalk enhances friction. However, no correlation with humidity/temperature and friction coefficient was noted which suggested that additional parameters should be considered in order to understand the effects of climate on finger friction in rock climbing.

  1. Reactive transport modelling of groundwater chemistry in a chalk aquifer at the watershed scale.

    Mangeret, A; De Windt, L; Crançon, P

    2012-09-01

    This study investigates thermodynamics and kinetics of water-rock interactions in a carbonate aquifer at the watershed scale. A reactive transport model is applied to the unconfined chalk aquifer of the Champagne Mounts (France), by considering both the chalk matrix and the interconnected fracture network. Major element concentrations and main chemical parameters calculated in groundwater and their evolution along flow lines are in fair agreement with field data. A relative homogeneity of the aquifer baseline chemistry is rapidly reached in terms of pH, alkalinity and Ca concentration since calcite equilibrium is achieved over the first metres of the vadose zone. However, incongruent chalk dissolution slowly releases Ba, Mg and Sr in groundwater. Introducing dilution effect by rainwater infiltration and a local occurrence of dolomite improves the agreement between modelling and field data. The dissolution of illite and opal-CT, controlling K and SiO(2) concentrations in the model, can be approximately tackled by classical kinetic rate laws, but not the incongruent chalk dissolution. An apparent kinetic rate has therefore been fitted on field data by inverse modelling: 1.5×10(-5) mol(chalk)L (-1) water year (-1). Sensitivity analysis indicates that the CO(2) partial pressure of the unsaturated zone is a critical parameter for modelling the baseline chemistry over the whole chalk aquifer. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Persistent and emerging micro-organic contaminants in Chalk groundwater of England and France

    Lapworth, D.J.; Baran, N.; Stuart, M.E.; Manamsa, K.; Talbot, J.

    2015-01-01

    The Chalk aquifer of Northern Europe is an internationally important source of drinking water and sustains baseflow for surface water ecosystems. The areal distribution of microorganic (MO) contaminants, particularly non-regulated emerging MOs, in this aquifer is poorly understood. This study presents results from a reconnaissance survey of MOs in Chalk groundwater, including pharmaceuticals, personal care products and pesticides and their transformation products, conducted across the major Chalk aquifers of England and France. Data from a total of 345 sites collected during 2011 were included in this study to provide a representative baseline assessment of MO occurrence in groundwater. A suite of 42 MOs were analysed for at each site including industrial compounds (n = 16), pesticides (n = 14) and pharmaceuticals, personal care and lifestyle products (n = 12). Occurrence data is evaluated in relation to land use, aquifer exposure, well depth and depth to groundwater to provide an understanding of vulnerable groundwater settings. - Highlights: • Broad range of microorganics detected in Chalk groundwater in England and France. • Plasticisers, pesticides, BPA and THM detected at the highest concentrations. • Pesticides higher in outcrop Chalk, caffeine and BPA at concealed sites. • Occurrences show some relationship to land use, borehole depth and water level. - Broad screening reveals for the first time the extent of emerging microorganic pollution in Chalk groundwater sources across England and France

  3. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    Maruthi, Y. A.; Das, N. Lakshmana; Ramprasad, S.; Ram, S. S.; Sudarshan, M.

    2015-01-01

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk

  4. Biot Critical Frequency Applied to Description of Failure and Yield of Highly Porous Chalk with Different Pore Fluids

    Andreassen, Katrine Alling; Fabricius, Ida Lykke

    2010-01-01

    Injection of water into chalk hydrocarbon reservoirs has led to mechanical yield and failure. Laboratory experiments on chalk samples correspondingly show that the mechanical properties of porous chalk depend on pore fluid and temperature. In case of water-saturated samples, the concentration...... is controlled by solid-fluid friction. The reference frequency is thus a measure of this friction, and we propose that the fluid effect on mechanical properties of chalk may be the result of liquid-solid friction. We reviewed 622 published experiments on mechanical properties of porous chalk. The data include...... chalk samples that were tested at temperatures from 20 °C to 130 °C with the following pore fluids: fresh water, synthetic seawater, glycol, and oil of varying viscosity. The critical frequency is calculated for each experiment. For each specimen, we calculate the thickness to the slipping plane outside...

  5. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    Maruthi, Y. A., E-mail: ymjournal2014@gmail.com [Associate professor, Dept of Environmental Studies, GITAM Institute of Science, GITAM University, Visakhapatnam, A.P (India); Das, N. Lakshmana, E-mail: nldas9@gmail.com [Professor, Dept of Physics, GITAM Institute of Science, GITAM University, Visakhapatnam, A.P (India); Ramprasad, S., E-mail: ramprasadsurakala@gmail.com [Research Scholar, Dept of Environmental science, GITAM Institute of Science, GITAM University, Visakhapatnam, A.P (India); Ram, S. S., E-mail: tracebio@gmail.com [Research Scholar, Dept of Trace element research, UGC-DAE Consortium Centre, Kolkata centre India (India); Sudarshan, M., E-mail: sude@alpha.iuc.res.in [Scientist-F, Dept of Trace element research, UGC-DAE Consortium Centre, Kolkata centre India (India)

    2015-08-28

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk.

  6. Structural and Lithological Controls upon Fluid Migration within the Chalk and Upper Greensand Aquifers in the Chilterns and Lambourn Downs

    Thompson, Sally

    2002-01-01

    The influence of lithological heterogeneities, structural discontinuities and discontinuity surface mineralisation upon groundwater migration within the Chalk and the Upper Greensand of southern England has been investigated. Lithological heterogeneities in the Chalk succession include marl seams, hardgrounds, tabular flints and nodular flints. Each of these heterogeneities has a lower intrinsic porosity and permeability than in the calcite rich chalk. The influence that each of these ...

  7. Summary on electron cyclotron theory

    Westerhof, E.

    2003-01-01

    The papers presented within the Theory Sessions of the conference clearly reflect the general trends of the research field. The growing use of Electron Bernstein Waves (EBW) for plasma heating and current drive in overdense plasmas goes hand in hand with an increased theoretical understanding of EBW excitation. While the expanding number of devices with powerful ECRH systems allowing ever more detailed experiments is reflected in the increased detail of modelling and consequent understanding of the experimental results. Apart from these general trends, some more fundamental contributions to the field of electron cyclotron wave propagation are highlighted. (author)

  8. Porosity and sonic velocity depth trends of Eocene chalk in Atlantic Ocean: Influence of effective stress and temperature

    Awedalkarim, Ahmed; Fabricius, Ida Lykke

    2014-01-01

    We aimed to relate changes in porosity and sonic velocity data, measured on water-saturated Eocene chalks from 36 Ocean Drilling Program drill sites in the Atlantic Ocean, to vertical effective stress and thermal maturity. We considered only chalk of Eocene age to avoid possible influence...... not show or at least it is difficult to define a clear pore-stiffening contact cementation trend as the Ontong Java Plateau chalk. Mechanical compaction is the principal cause of porosity reduction (at shallow depths) in the studied Eocene chalk, at least down to about 5MPa Terzaghi׳s effective stress...

  9. Studies of electron cyclotron emission on text

    Gandy, R.F.

    1990-07-01

    The Auburn University electron cyclotron emission (ECE) system has made many significant contributions to the TEXT experimental program during the past five years. Contributions include electron temperature information used in the following areas of study: electron cyclotron heating (ECH), pellet injection, and impurity/energy transport. Details of the role which the Auburn ECE system has played will now be discussed

  10. Cyclotrons for the production of radioactive beams

    Clark, D.J.

    1990-01-01

    This paper describes the characteristics and design choices for modern cyclotrons. Cyclotrons can be used in 3 areas in the radioactive beam field: the production of high energy heavy ion beams for use in fragmentation, the spallation of targets with high energy protons, and the acceleration of radioactive beams from low energy to the MeV/u range. 16 refs., 6 figs

  11. Isochronous cyclotron for thermonuclear reactors driving

    Alenitskij, Yu.G.

    1998-01-01

    The main requirements to an accelerator as a part of an electronuclear power plant are considered. The range of the parameters of the accelerated proton and deuteron beams, for which the isochronous cyclotron is the most profitable, is proposed. An opportunity of using the cyclotron to drive the research reactors of various types is considered

  12. Trends in cyclotrons for radionuclide production

    Vera Ruiz, H.; Lambrecht, R.M.

    1999-01-01

    The IAEA recently concluded a worldwide survey of the cyclotrons used for radionuclide production. Most of the institutions responded to the questionnaire. The responses identified technical, utilisation and administrative information for 206 cyclotrons. Compiled data includes the characteristics, performance and popularity of each of the different commercial cyclotrons. Over 20 cyclotrons are scheduled for installation in 1998. The expansion in the number of cyclotron installations during the last decade was driven by the advent of advances in medical imaging instrumentation (namely, positron emission tomography (PET), and more recently by 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons; and recent governmental decisions that permit reimbursement for cyclotron radiopharmaceutical studies by the government or insurance companies. The priorities for the production of clinical, commercial and research radionuclides were identified. The emphasis is on radionuclides used for medical diagnosis with SPET (e.g. 123 I, 201 Tl) and PET (e.g. 11 C, 13 N, 15 O, 18 F) radiopharmaceuticals, and for individualized patient radiation treatment planning (e.g. 64 Cu, 86 Y, 124 I) with PET. There is an emerging trend to advance the cyclotron as an alternative method to nuclear reactors for the production of neutron-rich radionuclides (e.g. 64 Cu, 103 Pd, 186 Re) needed for therapeutic applications. (authors)

  13. Wave fronts of electromagnetic cyclotron harmonic waves

    Ohnuma, T.; Watanabe, T.

    1982-01-01

    In an inhomogeneous high-density magnetized plasma, the spatial properties of the wave fronts and ray trajectories of electromagnetic ordinary and extraordinary cyclotron harmonic waves are investigated. Those waves which are radiated from a local source are found to have wave fronts which are almost parallel to the magnetic field. Also, the reflective properties of the electromagnetic cyclotron harmonic waves are confirmed

  14. Current oil and gas production from North American Upper Cretaceous chalks

    Scholle, Peter A.

    1977-01-01

    Production of oil and natural gas from North American chalks has increased significantly during the past five years, spurred by the prolific production from North Sea chalks, as well as by higher prices and improved production technology. Chalk reservoirs have been discovered in the Gulf Coast in the Austin Group, Saratoga and Annona Chalks, Ozan Formation, Selma Group, Monroe gas rock (an informal unit of Navarro age), and other Upper Cretaceous units. In the Western Interior, production has been obtained from the Cretaceous Niobrara and Greenhorn Formations. Significant, though subcommercial, discoveries of natural gas and gas condensate also have been made in the Upper Cretaceous Wyandot Formation on the Scotian Shelf of eastern Canada. All North American chalk units share a similar depositional and diagenetic history. The chalks consist primarily of whole and fragmented coccoliths with subordinate planktonic and benthonic Foraminifera, inoceramid prisms, oysters, and other skeletal grains. Most have between 10 and 35 percent HCl-insoluble residue, predominantly clay. Deposition was principally below wave base in tens to hundreds of meters of water. The diagenetic history of a chalk is critical in determining its reservoir potential. All chalk has a stable composition (low-Mg calcite) and very high primary porosity. With subsequent burial, mechanical and chemical (solution-transfer) compaction can reduce or completely eliminate pore space. The degree of loss of primary porosity in chalk sections is normally a direct function of the maximum depth to which it has been buried. Pore-water chemistry, pore-fluid pressures, and tectonic stresses also influence rates of cementation. Oil or gas reservoirs of North American chalk fall into three main groups: 1. Areas with thin overburden and significant primary porosity retention (for example, Niobrara Formation of Kansas and eastern Colorado). 2. Areas with thicker overburden but considerable fracturing. Here primary

  15. Recent development and progress of IBA cyclotrons

    Kleeven, W., E-mail: Willem.Kleeven@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Abs, M., E-mail: Michel.Abs@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Delvaux, J.L., E-mail: Jean-Luc.Delvaux@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Forton, E., E-mail: Eric.Forton@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Jongen, Y., E-mail: Yves.Jongen@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Medeiros Romao, L., E-mail: Luis.MedeirosRomao@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Nactergal, B., E-mail: Benoit.Nactergal@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Nuttens, V., E-mail: Vincent.Nuttens@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Servais, T., E-mail: Thomas.Servais@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Vanderlinden, T., E-mail: Thierry.Vanderlinden@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Zaremba, S., E-mail: Simon.Zaremba@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium)

    2011-12-15

    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 {sup 201}Tl 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{sup -}, D{sup -} and also {alpha}-particles. The {alpha}-beam of this cyclotron will allow the production of new therapeutic isotopes (e.g. {sup 211}At) 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.

  16. Developing the smallest possible medical cyclotron

    Katarina Anthony

    2011-01-01

    Imagine a portable medical cyclotron operated in a conventional radioactive facility at a hospital. Imagine a nurse or technician switching it on and producing isotopes at the patient’s bedside. Sounds like science fiction? Think again.   CERN has teamed up with Spain’s national scientific research centre (CIEMAT) to develop an avant-garde cyclotron to be used for Positron Emission Tomography (PET). “We plan to make a cyclotron that doesn't need an insulated building or ‘vault’: a cyclotron small enough to fit inside a hospital lift,” explains Jose Manuel Perez, who is leading the CIEMAT/CERN collaboration. “It will be the smallest possible medical cyclotron for single patient dose production and will dramatically reduce costs for hospitals.” While PET technology has transformed imaging techniques, many of its medical benefits have remained confined to highly specialised hospitals. “Studies have foun...

  17. Computer design of a compact cyclotron

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

    2011-01-01

    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

  18. Cyclotron-Resonance-Maser Arrays

    Kesar, A.; Lei, L.; Dikhtyar, V.; Korol, M.; Jerby, E.

    1999-01-01

    The cyclotron-resonance-maser (CRM) array [1] is a radiation source which consists of CRM elements coupled together under a common magnetic field. Each CRM-element employs a low-energy electron-beam which performs a cyclotron interaction with the local electromagnetic wave. These waves can be coupled together among the CRM elements, hence the interaction is coherently synchronized in the entire array. The implementation of the CRM-array approach may alleviate several technological difficulties which impede the development of single-beam gyro-devices. Furthermore, it proposes new features, such as the phased-array antenna incorporated in the CRM-array itself. The CRM-array studies may lead to the development of compact, high-power radiation sources operating at low-voltages. This paper introduces new conceptual schemes of CRM-arrays, and presents the progress in related theoretical and experimental studies in our laboratory. These include a multi-mode analysis of a CRM-array, and a first operation of this device with five carbon-fiber cathodes

  19. Production of radiopharmaceuticals by cyclotrons

    Schmitz, F.; Van Naemen, J.; Monclus, M.; Van Gansbeke, B.; Kadiata, M.; Ekelmans, D.; Moray, M.; Penninckx, R.; Goldman, S.

    2004-01-01

    Companies specialized in the development and installation of accelerator-based systems dedicated to the medical applications brought on the market cyclotrons well fitted to the requests of the industrial community or universities and so covering every segment of the market. These machines are fully automatic, and need reduced maintenance; they are highly specialized for defined tasks. They can produce high beam intensity and realize dual beam irradiation. Also the prices are reducing considerably. The targets and the automatic system follow the same trend. Unfortunately, the flexibility of these devices for new area of research and development has been dramatically reduced. The growing number of PET cameras has increased the popularity of PET tracers used for nuclear imaging. Consequently, there is a growing demand for these radiopharmaceuticals compounds labeled with short-lived radioisotopes for clinical applications. From a research and development tool in the eighties, PET has now grown up to a clinical tool. Moreover, depending of the social welfare, reimbursement of some PET examinations is granted, which accelerates the trend for an extended use of PET tracers. Regulatory affairs try to establish and standardize the control on these radiopharmaceutical compounds produced in a growing number of local radio pharmacies owning a baby cyclotron. On the other hand, the attention of equipment suppliers was brought in the setting up of a total quality control follow up. These efforts were successively achieved by getting for instance the ISO 9001 certificate

  20. Medical cyclotron basic concepts and its applications

    Kumar, Rajeev; Sonkawade, R.G.

    2012-01-01

    More than 3000 nuclides are known, of which approximately 2700 are radioactive, and rest are stable. The majority of radionuclides are artificially produced in the reactor and cyclotron. In a cyclotron, Charge particle such as proton, Deuteron, á (Alpha) particle, 3 He particles and so forth are accelerated in circular paths within the Dees under vacuum by means of an electromagnetic field. These accelerated particles can possess few KeV to several BeV of kinetic energy depending on the design of the cyclotron. At our setup we have an 11 MeV dual beam multi target cyclotron which is capable producing 11 C, 13 N, 15 O, 18 F and 2 F radioisotopes and all have been successfully produced and tested in our lab. Earlier cyclotrons were the best source of high-energy beams for nuclear physics experiments; several cyclotrons are still in use for this type of research. Cyclotrons can be used to treat cancer. Ion beams from cyclotrons can be used, as in proton therapy. The positron emitting isotopes are suitable for PET imaging. As discussed we are producing mainly Carbon-11, Nitrogen-13, Oxygen-15, and Fluorine-18: These are positron emitters used in PET for studying brain physiology and pathology, in particular for localizing epileptic focus, and in dementia, psychiatry and neuropharmacology studies. So these are having significant role in diagnosis of Oncological, Neurological and Cardiological disorder. More than ninety percent we are producing 18 F in FDG. 18 F in FDG (Flouro-Deoxy-glucose) has become very important in detection of cancers and the monitoring of progress in their treatment, using PET. Medical cyclotron is complex equipment requiring delicate handling by highly trained personnel. The aim of this article is to highlight few finer aspects of Medical cyclotron operation, including precautions for safety and smooth functioning of this sophisticated equipment. (author)

  1. THE STUDY OF TECHNOLOGICAL PROPERTIES OF PLASTISOLS BASED EMULSION PVC FILLED WITH CHALK GIDROFOBIZIROVANNYM

    V. A. Sedykh

    2014-01-01

    Full Text Available Baby toys are made using the centrifugal molding plastisol based emulsion of polyvinyl chloride plasticized with dioctylphthalate. To reduce cost and decrease biotelemetry the dioctylphthalate on the surface of the product domestic toys than toys produced in China, there was a necessity of introduction of the filler is chalk from different manufacturers. By using a Brookfield vis-cometer PV-D was studied rheology of filled hydrophobized chalk PVC plastisols in storage conditions for up to 72 hours at temperatures of 14-20°C. It was found that the flow plastisols consistent with pseudo-plastic fluids. Given the flow rates of emulsion PVC plastisols filled to 35 % of the mass. hydrophobized chalk. The influence of the content of the plasticizer dioctylphthalate in a narrow interval (37,0 - 41,4 % of the mass. on the viscosity of polymer pastes and the kinetics of its changes during storage. Revealed a linear dependence of the viscosity of the filled hydrophobized chalk plastisols on the speed of rotation of the spindle of the viscometer and during storage. Given the rate of expansion changes the viscosity of the plastisols of the speed of rotation of the spindle of the viscometer, the rate of change in viscosity and calculation of the initial viscosity. Determined the stability of the dispersion hydrophobized chalk in a colloidal solution of PVC in dioctylphthalate during storage. We determined the variation of the content of chalk (ash with top and bottom layers plastisols height 8 cm after 24 hours storage. It is proved that the temperature of the preparation and storage of polymer pastes were determining factors in the regulation of such technological properties of PVC plastisols in the presence hydrophobized chalkas viscosity, stability of the dispersion of chalk and, consequently, the efficiency of distribution plastisols in the form of a centrifugal molding.

  2. Stability analysis of chalk sea cliffs using UAV photogrammetry

    Barlow, John; Gilham, Jamie

    2017-04-01

    Cliff erosion and instability poses a significant hazard to communities and infrastructure located is coastal areas. We use point cloud and spectral data derived from close range digital photogrammetry to assess the stability of chalk sea cliffs located at Telscombe, UK. Data captured from an unmanned aerial vehicle (UAV) were used to generate dense point clouds for a 712 m section of cliff face which ranges from 20 to 49 m in height. Generated models fitted our ground control network within a standard error of 0.03 m. Structural features such as joints, bedding planes, and faults were manually mapped and are consistent with results from other studies that have been conducted using direct measurement in the field. Kinematic analysis of these data was used to identify the primary modes of failure at the site. Our results indicate that wedge failure is by far the most likely mode of slope instability. An analysis of sequential surveys taken from the summer of 2016 to the winter of 2017 indicate several large failures have occurred at the site. We establish the volume of failure through change detection between sequential data sets and use back analysis to determine the strength of shear surfaces for each failure. Our results show that data capture through UAV photogrammetry can provide useful information for slope stability analysis over long sections of cliff. The use of this technology offers significant benefits in equipment costs and field time over existing methods.

  3. Compaction monitoring in the Ekofisk area Chalk Fields

    Menghini, M.L.

    1989-01-01

    In late Nov. 1984, the subsidence phenomenon was recognized in the Ekofisk field. To determine the magnitude and areal extent of the formation compaction, a program for measuring compaction with electric logging tools was initiated. Initial time-lapse surveys performed with cased-hole neutron tools indicated that reservoir compaction was occurring, but the accuracy of the determination of compaction rate was low. In addition to the cased-hole neutron survey, radioactive markers and a gamma ray (GR) detection tool were used to determine compaction rate in the reservoir more accurately and to determine whether compaction was occurring in the overburden. A program for implanting radioactive-marker bullets and subsequent monitoring with a four-detector GR tool was implemented. There are currently 13 wells equipped with radioactive markers in the compaction monitoring program. Compaction monitoring accuracy using the four-detector GR tool was found to depend on wellbore geometry, completion design, and radioactive-marker placement. This paper gives the results of the program to date and describes the operational procedures and analysis techniques used for compaction monitoring in the greater Ekofisk area chalk fields

  4. Electron cyclotron resonance plasma photos

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

    2010-02-15

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

  5. Electron cyclotron resonance plasma photos

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

    2010-01-01

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

  6. Channeling experiments at IPNE Cyclotron

    Constantin, F; Dumitru, M; Ivan, A [Cyclotron Laboratory, Institute of Atomic Physics, Institute of Physics and Nuclear Engineering, R-76900 Bucharest, P.O.Box MG-6, (Romania)

    1992-01-01

    Channeling experiments have been performed at the I.P.N.E Cyclotron using a 3 MeV alpha beam. A slide system cut the beam up to 5 minutes spatial resolution with a maximum 60 nA beam current on the target. The two-axis goniometer, fully computer-controlled, moves the target, a silicon wafer, with 2.5 minute resolution, while an alpha particle sensitive solid state detector, monitors the backscattered particle fluence. In the first stage, channeling appears to be a simple, fast and reliable method for precise monocrystal orientation. A reduction of the host yield by a factor of two allowed impurities and defects to be studied. (Author).

  7. Cyclotron resonance in bilayer graphene.

    Henriksen, E A; Jiang, Z; Tung, L-C; Schwartz, M E; Takita, M; Wang, Y-J; Kim, P; Stormer, H L

    2008-02-29

    We present the first measurements of cyclotron resonance of electrons and holes in bilayer graphene. In magnetic fields up to B=18 T, we observe four distinct intraband transitions in both the conduction and valence bands. The transition energies are roughly linear in B between the lowest Landau levels, whereas they follow square root[B] for the higher transitions. This highly unusual behavior represents a change from a parabolic to a linear energy dispersion. The density of states derived from our data generally agrees with the existing lowest order tight binding calculation for bilayer graphene. However, in comparing data to theory, a single set of fitting parameters fails to describe the experimental results.

  8. Benthic macrofauna variations and community structure in Cenomanian cyclic chalk-marl from Southerham Grey Pit, SE England

    Lauridsen, Bodil Wesenberg; Gale, A. S.; Surlyk, Finn

    2009-01-01

    Cenomanian chalk-marl couplets from England represent the 20 ka Milankovitch precession cycle. Fossil communities from both chalk and marl are identified to test if the orbital fluctuations and the associated changes in substrate lithology and climate exerted any control on the benthic macrofauna...

  9. All-magnetic extraction for cyclotron beam reacceleration

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

    1975-07-22

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

  10. Twelve tips for the production of digital chalk-talk videos.

    Rana, Jasmine; Besche, Henrike; Cockrill, Barbara

    2017-06-01

    Increasingly over the past decade, faculty in medical and graduate schools have received requests from digital millennial learners for concise faculty-made educational videos. At our institution, over the past couple of years alone, several hundred educational videos have been created by faculty who teach in a flipped-classroom setting of the pre-clinical medical school curriculum. Despite the appeal and potential learning benefits of digital chalk-talk videos first popularized by Khan Academy, we have observed that the conceptual and technological barriers for creating chalk-talk videos can be high for faculty. To this end, this tips article offers an easy-to-follow 12-step conceptual framework to guide at-home production of chalk-talk educational videos.

  11. Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs

    Zahid, Adeel; Shapiro, Alexander; Stenby, Erling Halfdan

    2012-01-01

    of the temperature dependence of the oil recovery indicated that the interaction of the ions contained in brine with the rock cannot be the only determining mechanism of enhanced recovery. We observed no substitution of Ca2+ ions with Mg2+ ions at high temperatures for both rocks. Not only the injection brine......In recent years, many core displacement experiments of oil by seawater performed on chalk rock samples have reported SO42–, Ca2+, and Mg2+ as potential determining ions for improving oil recovery. Most of these studies were carried out with outcrop chalk core plugs. The objective of this study...... is to investigate the potential of the advanced waterflooding process by carrying out experiments with reservoir chalk samples. The study results in a better understanding of the mechanisms involved in increasing the oil recovery with potential determining ions. We carried out waterflooding instead of spontaneous...

  12. Permeability, porosity, dispersion-, diffusion-, and sorption characteristics of chalk samples from Erslev, Mors, Denmark

    Carlsen, L.; Batsberg, W.; Skytte Jensen, B.; Bo, P.

    1981-08-01

    A series of chalk samples from the cretaceous formation overlying the Erslev salt dome have been studied in order to establish permeabilities, porosities, dispersion-, diffusion-, and sorption characteristics of the chalk, Predominantly the investigations have been carried out by application of a liquid chromatographic technique. The chalk was found to be porous (epsilon approximately 0.4), however, of rather low permeability (k approximately 10 -7 cm/sec). It was found that the material exhibits a retarding effect on the migration of cationic species as Cs + , Sr 2+ , Co 2+ , and Eu 3+ , whereas anionic species as Cl - and TcO - 4 move with the water front. The geochemical implications are discussed. (author)

  13. Seismic geomorphology and origin of diagenetic geobodies in the Upper Cretaceous Chalk of the North Sea Basin (Danish Central Graben)

    Smit, F. W. H.; van Buchem, F.S.P.; Holst, J.H.

    2018-01-01

    that the geobodies are of an open-system diagenetic origin caused by ascending basin fluids guided by faults and stratigraphic heterogeneities. Increased amounts of porosity-occluding cementation, contact cement and/or high-density/-velocity minerals caused an impedance contrast that can be mapped in seismic data...... failure, followed by local mechanical compaction of high-porous chalks, paired with 2) ascension of basinal diagenetic fluids along fault systems that locally triggered cementation of calcite and dolomite within the chalk, causing increased contact cements and/or reducing porosity. The migration pathway...... of the fluids is marked by the SCRs, which are the outlines of high-density bodies of chalk nested in highly porous chalks. This study thus provides new insights into the 3D relationship between fault systems, fluid migration and diagenesis in chalks, and has important applications for basin modeling...

  14. Potential for isoproturon, atrazine and mecoprop to be degraded within a chalk aquifer system

    Johnson, Andrew C.; White, Craig; Lal Bhardwaj, C.

    2000-06-01

    The potential for herbicide degradation in an unconfined chalk aquifer was examined by collecting and spiking fresh samples and incubating them in the laboratory. The microcosms were incubated at 20°C under aerobic conditions and spiked with either isoproturon, atrazine or mecoprop at a concentration of 100 μg/l. The samples were obtained from a single fieldsite within the Upper Chalk aquifer in Hampshire, UK. Groundwater samples required the presence of sterile chalk in a ratio of at least 1:13 to promote isoproturon degradation. An isoproturon degradation potential existed in the soil, and the chalk unsaturated and saturated zones. However, no degradation of isoproturon in the unsaturated zone was observed when a more appropriate simulation of in-situ moisture conditions was carried out. Apart from the soil, no potential for atrazine or mecoprop degradation could be detected in the same samples over a 200-day incubation. In a series of groundwater samples taken from different boreholes, 10-300 m apart, large differences in isoproturon degradation potential were observed. Removal rates for 100 μg/l isoproturon varied from 83-425 ng/day, but in some samples no degradation potential could be detected. The primary metabolite which could be distinguished from isoproturon degradation in chalk and groundwater was monodesmethyl-isoproturon. When a chalk groundwater sample was spiked with isoproturon at 0.9 μg/l, this was not degraded over a 300-day incubation period. Further experiments with fresh groundwater from a Triassic Sandstone site illustrated that groundwater bacteria could degrade isoproturon at the more realistic temperature of 10°C as well as at 20°C.

  15. Method and apparatuses for ion cyclotron spectrometry

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

    2012-03-06

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

  16. NORTICA - a new code for cyclotron analysis

    Gorelov, D.; Johnson, D.; Marti, F.

    2001-01-01

    The new package NORTICA (Numerical ORbit Tracking In Cyclotrons with Analysis) of computer codes for beam dynamics simulations is under development at NSCL. The package was started as a replacement for the code MONSTER developed in the laboratory in the past. The new codes are capable of beam dynamics simulations in both CCF (Coupled Cyclotron Facility) accelerators, the K500 and K1200 superconducting cyclotrons. The general purpose of this package is assisting in setting and tuning the cyclotrons taking into account the main field and extraction channel imperfections. The computer platform for the package is Alpha Station with UNIX operating system and X-Windows graphic interface. A multiple programming language approach was used in order to combine the reliability of the numerical algorithms developed over the long period of time in the laboratory and the friendliness of modern style user interface. This paper describes the capability and features of the codes in the present state

  17. Development of a Medical Cyclotron Production Facility

    Allen, Danny R.

    2003-08-01

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

  18. Development of a Medical Cyclotron Production Facility

    Allen, Danny R.

    2003-01-01

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

  19. 10 GHz ECRIS for Warsaw Cyclotron

    Sudlitz, K

    1999-01-01

    Cusp type, 10 GHz ECRIS has been built and tested earlier. For obtaining intensive beams, more relevant for cyclotron, cusp geometry has been replaced by hexapole. Discharge chamber (stainless steel, 50 mm diameter, 250 mm long) is an extension of a coaxial line, feeding RF (9,6 GHz, up to 200 W) to the plasma. The NdFeB hexapole (0,52 T on the surface) has been used. The axial magnetic field is created by water cooled coils. The axial injection line dedicated to K160 isochronous heavy ion cyclotron has been constructed. The line consists of Glaser lenses, double focusing magnet, solenoid and mirror type inflector. The system provides sufficient transmission of the beam from ECR ion source to the firsts orbits of the cyclotron for m/q ranging from 7 to 2. After successful initial tests which were done in July 1997 the ECRIS serves as an external source for Warsaw Cyclotron.

  20. Application of superconductivity in cyclotron construction

    Blosser, H.G.

    1982-01-01

    This paper reviews major concepts and design features of the new class of cyclotrons which use superconducting coils to provide main magnet excitation. The discussion begins with a brief historical review tracing the evolution of these ''superconducting'' cyclotrons and the impact of this application of superconductivity in pushing back traditional cyclotron construction limits. This is followed by a review of the principal phenomena which come into play to set new limits on the operating regime, and the nature of these limits, some of which arise from orbit properties and some of which result from construction intricacies in the coil and in the rf system. Conclusions anticipate a future widely encompassing role in the application of superconductivity to cyclotron

  1. Progress report: Variable Energy Cyclotron Centre, Calcutta

    1999-01-01

    This volume of the progress report brings out the scientific and technical activities of Variable Energy Cyclotron Centre, Calcutta during the year 1999. This includes brief review of the various R and D activities of the Centre and outside users of the cyclotron from the universities and other research institutes. The operational activities of the cyclotron with ECR ion sources, accelerator oriented research activities, activities on detector, target and electronics are reported. The activities of the Computer and Informatics group are described. The status report of the ongoing projects is also provided. The main activities of the superconducting cyclotron project, radioactive ion beam project, heavy ion experimental facility, advanced computational facility, recovery and analysis of helium from hot springs and material science research are described

  2. Electron cyclotron emission imaging in tokamak plasmas

    Munsat, T.; Domier, C.W.; Kong, X. Y.; Liang, T. R.; N C Luhmann Jr.,; Tobias, B. J.; Lee, W.; Park, H. K.; Yun, G.; Classen, I.G.J.; Donne, A. J. H.

    2010-01-01

    We discuss the recent history and latest developments of the electron cyclotron emission imaging diagnostic technique, wherein electron temperature is measured in magnetically confined plasmas with two-dimensional spatial resolution. The key enabling technologies for this technique are the

  3. Cyclotron/PET project in Uruguay

    Engler, H.

    2006-01-01

    The Positron Computed Tomography (PET) is a tri dimensional image technique which shows biochemical information. PET is used in neurology and cardiology diseases. The National Center Cyclotron PET has been found to research, development and health science applications.

  4. Cyclotron method for heavy ion acceleration

    Gikal, B.N.; Gul'bekyan, G.G.; Kutner, V.B.; Oganesyan, R.Ts.

    1984-01-01

    Studies on heavy ion beams in a wide range of masses (up to uranium) and energies disclose essential potential opportunities for solution of both fundamental scientific and significant economical problems. A cyclotron method for heavy ion acceleration is considered. Development of low and medium energy heavy ion accelerators is revealed. The design of a complex comprising two isochronous cyclotrons which is planned to be constrdcted 1n the JINR is described. The cyclotron complex includes the U-400 and the U-400 M cyclotrons and it is intended for acceleration of both 35-20 MeV/nucleon superheavy ions such as Xe-U and 120 MeV/nucleon light ions. Certain systems of the accelerators are described. Prospects of the U-400 and the U-400 M development are displayed

  5. Wettability of Chalk and Argillaceous Sandstones Assessed from T1/T2 Ratio

    Katika, Konstantina; Saidian, M.; Fabricius, Ida Lykke

    ratio can quantify the affinity between the rock and wetting pore fluid. The affinity is a measure directly linked to wettability. In order to investigate the T2-shortening, we performed T1-T2 NMR experiments on different samples of chalk, Berea sandstone, and chloritic greensand, saturated either...... with water, oil or oil/water at irreducible water saturation. The T1/T2 ratio obtained from T1-T2 maps reflects the T2-shortening. We compare the T1/T2 ratio for the same type of rock, saturated with different fluids. The chalk shows high affinity for water, Berea sandstone has no clear preference for oil...

  6. The surface reactivity of chalk (biogenic calcite) with hydrophilic and hydrophobic functional groups

    Okhrimenko, D. V.; Dalby, K. N.; Skovbjerg, L. L.; Bovet, N.; Christensen, J. H.; Stipp, S. L. S.

    2014-03-01

    The surface properties of calcium carbonate minerals play an important role in a number of industrial and biological processes. Properties such as wettability and adsorption control liquid-solid interface behaviour and thus have a strong influence on processes such as biomineralisation, remediation of aquifers and oil recovery. We investigated how two model molecules of different polarity, namely water and ethanol, interact with reservoir and outcrop chalk samples and we compared their behaviour with that of pure, inorganically precipitated calcite. Thermodynamic quantities, such as the work of wetting, surface energy and isosteric adsorption enthalpy, were determined from vapour adsorption isotherms. The chalks were studied fresh and after extraction of organic residues that were originally present in these samples. The work of wetting correlates with the amount of organic matter present in the chalk samples but we observed a fundamental difference between the adsorption properties of chalk and pure, inorganically precipitated calcite toward the less polar, ethanol molecule. Further analysis of the chemical composition of the organic matter extracted from the chalk samples was made by gas chromatography (GC-MS). Monitoring surface composition by X-ray photoelectron spectroscopy (XPS) before and after extraction of the organic material, and with atomic force microscopy (AFM), showed that nanometer sized clay crystals observed on the chalk particle surfaces could be an important part of the reason for the differences. Removal of the extractable portion of the hydrocarbons liberates adsorption sites that have different wetting properties than the rest of the chalk and these have an energy distribution that is similar to clays. Thus, the results exemplify the complexity of biogenic calcite adsorption behaviour and demonstrate that chalk wetting in drinking water aquifers as well as oil reservoirs is controlled partly by the nanoparticles of clay that have grown on the

  7. Marine macrofossil communities in the uppermost Maastrichtian chalk of Stevns Klint, Denmark

    Hansen, Thomas; Surlyk, Finn

    2014-01-01

    Three successive marine habitats and their benthic macrofossil communities have been recognised and assessed in the uppermost Maastrichtian chalk of Stevns Klint, Denmark. The mound-bedded lower Sigerslev Member was deposited below the photic zone under the influence of persistent, non-erosive bo......Three successive marine habitats and their benthic macrofossil communities have been recognised and assessed in the uppermost Maastrichtian chalk of Stevns Klint, Denmark. The mound-bedded lower Sigerslev Member was deposited below the photic zone under the influence of persistent, non...

  8. Capillary fringe and tritium and nitrogen tracing history in the Senonian chalk of Champagne

    Ballif, J.L.

    1998-01-01

    In the middle of Champagne-Ardenne area, a chalky zone is located, directly on top of which lies the soil and in which the water table is relatively close the soil; which allows for capillary direction to the surface horizons and the renewal of water reserve. After the presentation of the hydrological characteristics, the total porosity of chalk, the pores distribution, the capillary attraction is shown by the hydrological comportment of the soil and the upper part of the unsaturated zone of chalk. In the homogeneous rock, the tritium and nitrogen transfers reveal the historical tracks. (authors)

  9. Progress report on the Milan superconducting cyclotron

    Acerbi, E.; Alessandria, F.; Baccaglioni, G.; Bellomo, G.; Birattari, C.; Bosotti, A.; Broggi, F.; Cortesi, G.; DeMartinis, C.; Fabrici, E.; Ferrari, A.; Giove, D.; Giussani, A.; Giussani, W.; Michelato, P.; Pagani, C.; Rivoltella, G.; Rossi, L.; Serafini, L.; Sussetto, A.; Torri, V.; Varisco, G.; Cuttone, G.; Raia, G.; Kai, L.

    1988-01-01

    This paper reports on the construction of the K800 superconducting cyclotron at the University of Milan underway since February 1981. The delay in the construction of the new building and a defect of the weldings of the helium vessel have caused a shift in the project schedule of about two years. Currently, the cyclotron magnet and the cryogenic plant have been completed and installed. First operation of the magnet and magnetic field mapping are to begin shortly

  10. Building 211 cyclotron characterization survey report

    NONE

    1998-03-30

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

  11. NIRS-Chiba isochronous cyclotron 1975

    Ogawa, H.; Kumamoto, Y.; Yamada, T.; Hiramoto, T.

    1976-02-01

    The cyclotron facility installed according to the recommendation of the Atomic Energy Committee of Japan is used for neutron therapy and production of short-lived radioisotopes. Construction on the facility was started in the autumn of 1972, and completed in March 1974. Described are the following: beam transport and the experimental hall, machine research and improvement, machine time sharing and the particles and energies, characteristics of the cyclotron, and facility personnel. (auth.)

  12. Initial operation of the cyclotron CYTRACK

    Denisov, Yu.N.; Dolya, S.N.; Kalinichenko, V.V.; Karamysheva, G.A.; Kostromin, S.A.; Fedorenko, S.B.

    2005-01-01

    The industrial cyclotron CYTRACK is dedicated to produce the track membranes. It is the basic instrument for the industry of membrane products to be consumed in medicine, biotechnology, pharmacology, microelectronics and many other industries. Cyclotron CYTRACK started working in August 2002. Argon ions were accelerated to the project energy - 2.4 MeV/nucleon, the extracted beam intensity was about 200 nA, the extraction efficiency totaled ∼50%

  13. Cyclotron beam dynamic simulations in MATLAB

    Karamysheva, G.A.; Karamyshev, O.V.; Lepkina, O.E.

    2008-01-01

    MATLAB is useful for beam dynamic simulations in cyclotrons. Programming in an easy-to-use environment permits creation of models in a short space of time. Advanced graphical tools of MATLAB give good visualization features to created models. The beam dynamic modeling results with an example of two different cyclotron designs are presented. Programming with MATLAB opens wide possibilities of the development of the complex program, able to perform complete block of calculations for the design of the accelerators

  14. Rock physical aspects of CO{sub 2} injection in chalk

    Alam, M.M.

    2011-04-15

    Impact of supercritical CO{sub 2} on the petrophysical and rock-mechanics properties of Ekofisk Formation and Tor Formation chalk from South Arne field, Danish North Sea, chalk was investigated. A series of laboratory experiments was performed on core material collected from the reservoir zone of the South Arne field in order to reveal the changes with respect to porosity, specific surface, pore stiffness, wettability, mineralogy and mechanical failure. In addition, a theoretical rock physical background was also established in order to be able to make sensible interpretation of laboratory data. Sound wave velocity was used as the central tool to study any change in petrophysical and rock mechanical properties. The main focus was to achieve a better understanding of effective stress coefficient (also known as Biot's coefficient); by means of which effective stress can be predicted more accurately. Independent theoretical studies were made on diagenesis, surface properties and stiffness of chalk and their relation with sonic velocity (or Biot's coefficient calculated from sonic velocity). The knowledge and experience from these studies was combined to achieve the main research objective of monitoring changes in hydrocarbon reservoirs in chalk due to CO{sub 2} injection. In order to understand the development of chalk from calcareous ooze and achieving pore stiffness, the diagenesis process of a sedimentary sequence from Kerguelen Plateau in the Indian Ocean was studied. The principal objective of the study was to explore how different porosity reduction mechanisms change the strength of these deep sea carbonate-rich sediments and how these mechanisms can be traced from the change in Biot's coefficient, alpha. In calcareous ooze, alpha was found close to one. Mechanical compaction reduces porosity, but only leads to a minor decrease in alpha. Recrystallization process renders particles smoother, but do not lead to reduction in alpha unless it gives

  15. Ion-cyclotron-resonance- and Fourier-transform-ion-cyclotron-resonance spectroscopy: technology and application

    Luederwald, I.

    1977-01-01

    Instrumentation and technology of Ion-Cyclotron-Resonance and Fourier-Transform-Ion-Cyclotron-Resonance Spectroscopy are described. The method can be applied to studies of ion/molecule reactions in gas phase, to obtain thermodynamic data as gas phase acidity or basicity, proton and electron affinity, and to establish reaction mechanisms and ion structures. (orig.) [de

  16. A national medical cyclotron facility: report to the Minister of Health by the Medical Cyclotron Committee

    1985-01-01

    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 in relevant fields of medicine, and for diagnostic use in nuclear medicine

  17. 57 Co produced in cyclotron

    Landini, Liliane; Osso Junior, Joao Alberto

    2000-01-01

    The Cyclotron CV-28 of IPEN-CNEN/SP is a particle accelerator, used mainly in the radioisotope production, applied in 'in vivo' diagnosis in nuclear medicine. Some of them are employed in the calibration of Diagnosis equipment, such as gamma and X-rays detectors. Co-57 is an example of this application. A natural nickel foil was used as target and irradiated with proton beams of 24 MeV energy. The radioactivity analysis of the irradiated target was performed by Gamma Spectroscopy with a HPGe detector. A 259,74MBq (7,02 mCi) Co-57 source was prepared, 67 days after the last bombardment, with impurity levels of 1.13% for Co-56 and 1.29% for Co-58. The thick target yields for Co-57 and for the main radionuclidic impurities were measured, after the chemical separation of the irradiated target, extrapolated to the last EOB: 1.076 MBq (29.09 mCi)/mA.h, 0.012 MBq (0.33 mCi)/mA.h and 0.014 MBq (0.37 mCi)/mA.h, for Co-57, Co-56 and Co-58, respectively. (author)

  18. Electron cyclotron heating of plasmas

    Guest, Gareth

    2009-01-01

    As nuclear fusion becomes an increasingly important potential energy source in these times of global oil and energy crises, the development of technologies that can lead to the realization of this virtually inexhaustible source of energy takes on ever greater urgency. Over the past decade electron cyclotron heating has undergone a significant maturation and has emerged as an essential component of the major approaches to achieving controlled nuclear fusion. The gyrotron, first developed in the Soviet Union, has made it possible to employ ECH in large tokamak and stellarator fusion devices by providing megawatts of microwave power at frequencies above 100 GHz. A contemporary VGT-8110 gyrotron, for example, shown here with Kevin Felch and Pat Cahalan of Communications and Power Industries, is capable of delivering 10 second pulses of 1 MW of power at 110 GHz. The present monograph addresses the ECH physics critical to the international fusion reactor experiment, ITER, but also presents the fundamentals of ECH that are essential to its successful implementation in applications that range from active experiments in planetary magnetospheres to commercial plasma sources for the manufacture of computer chips. The book seeks to convey the physics of ECH in an orderly and coherent fashion to a professional audience by presenting the basic theoretical foundations and then using the theory to interpret a number of established experimental results. Exercises are included to aid the reader in making the theory more concrete. (orig.)

  19. Cyclotron tubes - a theoretical study

    Mourier, G

    1980-12-01

    The introduction presents a general discussion of electron cyclotron masers (ECM): resonance, relativistic effects, elementary quantum aspects, the classical relativistic bunching and the optimum value of the electric field. The practical structure - in particular that of the gyrotron - is specified only insofar as it is useful for understanding the following chapters. The main parameters are discussed. Section 2 develops a nonlinear adiabatic or orbital theory of electron motion which alleviates calculations considerably while keeping numerical errors low enough for many practical cases. Its results are compared to a rigorous integration in one case. Other cases show the importance of the electric field profile inside the resonant cavity. Section 3 is devoted to space charge phenomena, and, for the most part, to a linear theory with space charge. In its limited range of validity (low-energy electrons), the theory indicates a strong impact of space charge for low a.c. fields and exhibits a pure beam instability. Section 4 is devoted to circuit equations with emphasis on the special features of cavities consisting of a long waveguide near cutoff. The conclusion indicates some trends of gyrotron development and corresponding theoretical problems.

  20. Uranium series geochemistry in aquifers: quantification of transport mechanisms of uranium and daughter products: the chalk aquifer (Champagne, France)

    Hubert, A.

    2005-09-01

    With the increase of contaminant flux of radionuclides in surface environment (soil, river, aquifer...), there is a need to understand and model the processes that control the distribution of uranium and its daughter products during transport within aquifers. We have used U-series disequilibria as an analogue for the transport of uranium and its daughter products in aquifer to understand such mechanisms. The measurements of uranium ( 234 U et 238 U), thorium ( 230 Th et 232 Th), 226 Ra and 222 Rn isotopes in the solid and liquid phases of the chalk aquifer in Champagne (East of France) allows us to understand the processes responsible for fractionation within the uranium decay chain. Fractionations are induced by physical and chemical properties of the elements (leaching, adsorption) but also by radioactive properties (recoil effect during α-decay). For the first time a comprehensive sampling of the solid phase has been performed, allowing quantifying mechanisms responsible for the long term evolution of the aquifer. A non steady state 1D model has been developed which takes into account leaching, adsorption processes as well as radioactive filiation and α-recoil effect. Retardation coefficients have been calculated for uranium, thorium and radium. The aquifer is characterised by a double porosity, and the contribution of fracture and matrix porosity on the water/rock interaction processes has been estimated. (author)

  1. Effect of fluid-solid friction on the stiffness of chalk

    Alam, Mohammad Monzurul; Nguh Akam, Hosea; Fabricius, Ida Lykke

    2011-01-01

    Chalks behave weaker at water saturated condition. We studied this softening effect as a function of Biot’s frequency ratio, which is a ratio between measured ultrasonic wave frequency and Biot critical frequency, fc. Kinematic viscosity of fluid and permeability of rock determines fc. We observe...

  2. Aerobic degradation potential of the herbicides mecoprop, dichlorprop and bentazone in groundwater from chalk aquifers

    Levi, Suzi; Hybel, Anne-Marie; Bjerg, Poul Løgstrup

    2011-01-01

    The aerobic degradation potential of mecoprop, dichlorprop and bentazone was studied at concentration of 1 μg/L in laboratory batch experiments with groundwater from chalk aquifers. Within the incubation period of 129 days, 14C-mecoprop concentration decreased to 60-80% in the microcosms with gro...

  3. Using Raman spectroscopic imaging for non-destructive analysis of filler distribution in chalk filled polypropylene

    Boros, Evelin; Porse, Peter Bak; Nielsen, Inga

    2016-01-01

    A feasibility study on using Raman spectral imaging for visualization and analysis of filler distribution in chalk filled poly-propylene samples has been carried out. The spectral images were acquired using a Raman spectrometer with 785 nm light source.Eight injection-molded samples with concentr...

  4. Waveform analysis of crosshole GPR data collected in heterogeneous chalk deposits

    Keskinen, Johanna; Nielsen, Lars; Zibar, Majken Caroline Looms

    2014-01-01

    Chalks are important reservoirs for groundwater production onshore Denmark and for hydrocarbons in the North Sea Basin. Therefore this rock type is studied extensively with geological and geophysical methods. Ground-penetrating radar (GPR) tomography is used to characterize fine-scale reservoir...

  5. Measuring and Modeling the Displacement of Connate Water in Chalk Core Plugs during Water Injection

    Korsbech, Uffe C C; Aage, Helle Karina; Andersen, Bertel Lohmann

    2006-01-01

    and forms a mixed water bank with almost 100% connate water in the front behind which a gradual transition to pure injection water occurs. This result underpins log interpretations from waterflooded chalk reservoirs. An ad hoc model was set up by use of the results, and the process was examined...

  6. Reservoir fracture mapping using microearthquakes: Austin chalk, Giddings field, TX and 76 field, Clinton Co., KY

    Phillips, W.S.; Rutledge, J.T.; Gardner, T.L. [SPE, Richardson, TX (United States); Fairbanks, T.D.; Miller, M.E.; Schuessler, B.K. [Los Alamos National Lab., NM (United States)

    1996-11-01

    Patterns of microearthquakes detected downhole defined fracture orientation and extent in the Austin chalk, Giddings field, TX and the 76 field, Clinton Co., KY. We collected over 480 and 770 microearthquakes during hydraulic stimulation at two sites in the Austin chalk, and over 3200 during primary production in Clinton Co. Data were of high enough quality that 20%, 31% and 53% of the events could be located, respectively. Reflected waves constrained microearthquakes to the stimulated depths at the base of the Austin chalk. In plan view, microearthquakes defined elongate fracture zones extending from the stimulation wells parallel to the regional fracture trend. However, widths of the stimulated zones differed by a factor of five between the two Austin chalk sites, indicating a large difference in the population of ancillary fractures. Post-stimulation production was much higher from the wider zone. At Clinton Co., microearthquakes defined low-angle, reverse-fault fracture zones above and below a producing zone. Associations with depleted production intervals indicated the mapped fractures had been previously drained. Drilling showed that the fractures currently contain brine. The seismic behavior was consistent with poroelastic models that predicted slight increases in compressive stress above and below the drained volume.

  7. Can we get a better knowledge on dissolution processes in chalk by using microfluidic chips?

    Neuville, Amélie; Minde, Mona; Renaud, Louis; Vinningland, Jan Ludvig; Dysthe, Dag Kristian; Hiorth, Aksel

    2017-04-01

    This work has been initiated in the context of research on improving the oil recovery in chalk bedrocks. One of the methods to improve the oil recovery is to inject "smart water" (acidic water/brines). Experiments on core scale and field tests that have been carried out the last decade have clearly shown that water chemistry affects the final oil recovery. However, there is generally no consensus in the scientific community of why additional oil is released, and it is also still not understood what are the mineralogical and structural changes. Direct in situ observation of the structural changes that occur when chalk is flooded with brines could resolve many of the open questions that remain. One of the highlights of this work is thus the development of an innovative methodology where fluid/rock interactions are observed in-situ by microscopy. To do so, we create several types of custom-made microfluidic systems that embeds reactive materials like chalk and calcite. The methodology we develop can be applied to other reactive materials. We will present an experiment where a calcite window dissolves with a fluid, where we observe in-situ the topography features of the calcite window, as well as the dissolution rate [1]. The injected fluid circulates at controlled flowrates in a channel which is obtained by xurography: double sided tape is cut out with a cutter plotter and placed between the reactive window and a non-reactive support. While the calcite window reacts, its topography is measured in situ every 10 s using an interference microscope, with a pixel resolution of 4.9 μm and a vertical resolution of 50 nm. These experiments are also compared with reactive flow simulations done with Lattice Boltzmann methods. Then, we will present a dissolution experiment done with a microfluidic system that embeds chalk. In this experiment, the main flow takes place at the chalk surface, in contact with fluid flowing in a channel above the chalk sample. Thus the reaction

  8. Analysis of fine-dispersed chalk usage as mineral additive in the composition of sand aggrerate concrete

    Светлана Николаевна Чепурная

    2016-12-01

    Full Text Available The research results of fine-disperse chalk addition on physical and mechanical properties of the cement stone and concrete are shown. It is determined that fine-disperse chalk addition in the binder composition increases the content of ultrafine particles. The chalk particles fill the pore space between the cement particles, increasing the packing density, which leads to a density increase, which consequently leads to improved physical and mechanical properties of the concrete: water tightness, cold resistance, corrosion resistance, crack resistance and other properties

  9. Neutron radiography by using JSW baby cyclotron

    Toda, Yojiro

    1995-01-01

    At present, JSW baby cyclotrons are mostly used for the production of the radioisotopes for medical use. The attempt to use this baby cyclotron for neutron radiography began already in 1981. The feasibility of the neutron radiography for the explosives in metallic cases which are used for H1 rockets was investigated. In 1983, it was shown that the neutron radiography by using the baby cyclotron in Muroran Works, Japan Steel Works, Ltd. was able to be carried out as a routine work. Since then, the nondestructive inspection by neutron radiography has been performed for rocket pyrotechnic articles, and contributed to heighten their reliability. Further, the radiography by using fast neutrons was developed and put to practical use for recent large H2 rockets. The JSW baby cyclotron BC 168 which has been used for neutron radiography can accelerate 16 MeV protons or 8 MeV deuterons up to 50 μA. The principle of thermal neutron radiography is the generation of fast neutrons by irradiating a Be target with the proton beam accelerated by a baby cyclotron, the moderation of the fast neutrons, the formation of the thermal neutron flux of uniform distribution with a collimator, the thermal neutron flux hitting the Gd plate in a film cassette through an object, and the exposure of an X-ray film to electrons from the Gd plate. Fast neutron radiography apparatus, and commercial neutron radiography are described. (K.I.)

  10. 83-inch cyclotron research program. Final report

    Parkinson, W.C.

    1983-07-01

    In June of 1960 the US Atomic Energy Commission authorized the construction of a modern variable energy cyclotron facility at The University of Michigan to be used for research in nuclear spectroscopy. The Legislature of the State of Michigan made available funds for construction of a building to house the 83-inch cyclotron and auxiliary equipment as well as the University's remodeled 42-inch cyclotron. The research program centered around the 83-inch cyclotron was funded by the AEC and its successors, the Energy Research and Development Administration (ERDA) and the Department of Energy (DOE), from September 1964 through March 1977. The program represented a continuation of the research effort using the 42-inch cyclotron facility which had been supported continuously by the AEC since February 1950. This final report to DOE briefly describes the research facility, the research program, and highlights the principal accomplishments of the effort. It begins with a historical note to place this effort within the context of nuclear physics research in the Department of Physics of the University of Michigan

  11. Manufacturing on the radiopharmaceuticals produced by cyclotron

    Ueda, Nobuo

    1994-01-01

    Radiopharmaceutical (RP) produced by cyclotrons are widely used for the in vivo diagnosis of various diseases such as cancer, cerebral vascular disorders and cardiac diseases. The nuclides used as RPs and their nuclear reactions, and the quantity of RPs supplied in Japan in the last five years are shown. These RPs are delivered to about 1,100 hospitals in Japan. Thallium-201 and iodine-123 showed very high growth rate. Recently, two new I-123 RPs, BMIPP and MIBG which are heart-imaging agents, have been supplied. It suggests that the quantity of I-123 will increase much more in future. The image diagnostic method using RPs is called in vivo nuclear medicine, and has become the indispensable means for medical institutions together with X-ray CT, nuclear magnetic resonance imaging and ultrasonic diagnosis. The RPs for in vivo diagnosis generally used at present are classified into those labeled with the RIs produced with cyclotrons and those labeled with Tc-99m formed by the decay of Mo-99. The quantity being used is overwhelmingly more in the latter, but the former shows the tendency of growth. The commercial production of cyclotron RIs for medical use, the chemical forms and the diagnostic purposes of the RPs using cyclotron RIs, and the state of use of the cyclotron-produced RPs are reported. (K.I.)

  12. Low energy cyclotron for radiocarbon dating

    Welch, J.J.

    1984-12-01

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity 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 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 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

  13. Recycling and recommissioning a used biomedical cyclotron

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

    2001-01-01

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

  14. Superconducting cyclotron magnet coil short

    Mallory, M.L.; Blosser, H.G.; Clark, D.J.; Launer, H.; Lawton, D.; Miller, P.; Resmini, F.

    1982-01-01

    In February 1981, a short circuit appeared in the superconducting coil of the K500 cyclotron. The short is resistive in character and therefore has no effect on steady state operation of the magnet. The resistance of the short varies, sometimes being below threshold of detection as a heat load on the cooling system and sometimes being significant. The resistance under certain conditions shows approximately cyclic phenomena with time constants in the range of seconds and other approximately cyclic phenomena which correlate with gross operating parameters of the magnet (shifting current from one coil to another at high field and lowering and raising the liquid helium level). A number of diagnostic studies of the short have been made, using 1) an array of flux sensing loops to sense the magnetic effect of the short, 2) voltage comparisons between upper and lower sections of the coil, 3) comparisons of forces in the nine member coil support system and 4) the effect of the short on the thermal charactersitics of the coil. Insulation failure or a metal chip shorting out turns have been explored in some detail but a convincing determination of the exact cause of the short may never be available, (even the extreme step of unwinding the coil having a significant probability that an imperfection with the observed characteristics would pass unnoticed). Analysis of the characteristics of the short indicated that the most serious consequence would be failure of the coils mechanical support system in the event that the magnet was quickly discharged, as in a dump or quench. To deal with this hazard, the support system has been modified by installing solid supports which prevent the coil from moving by an amount sufficient to damage the support system. We have also reexamined the data and calculations used in the original coil design and have made some additional measurements of the properties of the materials (yield strength, friction coefficient, Young's modulus) used in the

  15. Radiation shielding and health physics instrumentation for PET medical cyclotrons

    Mukherjee, B.

    2002-01-01

    Full text: Modern Medical Cyclotrons produce a variety of short-lived positron emitting PET radioisotopes, and as a result are the source of intense neutron and gamma radiations. Since such cyclotrons are housed within hospitals or medical clinics, there is significant potential for un-intentional exposure to staff or patients in proximity to cyclotron facilities. Consequently, the radiological hazards associated with Cyclotrons provide the impetus for an effective radiological shielding and continuous monitoring of various radiation levels in the cyclotron environment. Management of radiological hazards is of paramount importance for the safe operation of a Medical Cyclotron facility. This work summarised the methods of shielding calculations for a compact hospital based Medical Cyclotron currently operating in Canada, USA and Australia. The design principle and operational history of a real-time health physics monitoring system (Watchdog) operating at a large multi-energy Medical Cyclotron is also highlighted

  16. Statistical fluctuations in cooperative cyclotron radiation

    Anishchenko, S. V.; Baryshevsky, V. G.

    2018-01-01

    Shot noise is the cause of statistical fluctuations in cooperative cyclotron radiation generated by an ensemble of electrons oscillating in magnetic field. Autophasing time - the time required for the cooperative cyclotron radiation power to peak - is the critical parameter characterizing the dynamics of electron-oscillators interacting via the radiation field. It is shown that premodulation of charged particles leads to a considerable narrowing of the autophasing time distribution function for which the analytic expression is obtained. When the number of particles Ne exceeds a certain value that depends on the degree to which the particles have been premodulated, the relative root-mean-square deviation (RMSD) of the autophasing time δT changes from a logarithmic dependence on Ne (δT ∼ 1 / lnNe) to square-root (δT ∼ 1 /√{Ne }). A slight energy spread (∼4%) results in a twofold drop of the maximum attainable power of cooperative cyclotron radiation.

  17. Decommissioning analyzis of a university cyclotron

    Eggermont, G.X.; Buls, N.; Hermanne, A.

    1996-01-01

    In the widespread use of some medical nuclear facilities, such as cyclotrons for isotope production, Life cycle analyzis, including decommissioning, was not taken into account. The structural materials of an accelerator and the concrete shielding of the bunker are activated by neutrons. This could yield a considerable volume of nuclear waste and needs radiation protection concern for occupational workers and the environment during some decennia. At the university of Brussels (WB) a prospective radiation protection and waste analyzis is being made for the later decommissioning of their cyclotron. Only few similar studies have been published. In Belgium future nuclear dismantling operations will be submitted to a radiation protection authorization procedure. Meanwhile the nuclear waste authorities insist on dismantling planning, including financial provisioning. An optimization exercise was made at the VUB-cyclotron, taking into account international trends to clearance levels for low level nuclear waste. Conceptual prevention opportunities e.g. selective material choice could be identified for future accelerator constructions. (author)

  18. Scientific instruments, scientific progress and the cyclotron

    Baird, David; Faust, Thomas

    1990-01-01

    Philosophers speak of science in terms of theory and experiment, yet when they speak of the progress of scientific knowledge they speak in terms of theory alone. In this article it is claimed that scientific knowledge consists of, among other things, scientific instruments and instrumental techniques and not simply of some kind of justified beliefs. It is argued that one aspect of scientific progress can be characterized relatively straightforwardly - the accumulation of new scientific instruments. The development of the cyclotron is taken to illustrate this point. Eight different activities which promoted the successful completion of the cyclotron are recognised. The importance is in the machine rather than the experiments which could be run on it and the focus is on how the cyclotron came into being, not how it was subsequently used. The completed instrument is seen as a useful unit of scientific progress in its own right. (UK)

  19. Radiation exposure to workers at cyclotron facilities

    Ribeiro, M.S.; Sanches, M.P.; Sanchez, A.S.; Rodrigues, D.L.

    2001-01-01

    Radiopharmaceuticals quickly furnish the information doctors need to establish a precise diagnosis of the patient's condition, and therefore to prescribe the most effective therapy. In cancerology, F18-FDG, the most widely used PET imaging tracer, excels in the early detection of cancer tumors, even very tiny ones, which it locates and clearly distinguishes from healthy surrounding tissues. IPEN-CNEN/SP has two cyclotron accelerators used mainly for radioisotope production to be utilized in nuclear medicine for diagnosis and therapy. The first is a CV-28 cyclotron, variable energy that came into operation in 1982, which was used to produce F18-FDG and Iodine 123 up to 1998. The second, a Cyclone 30 cyclotron, 30 MeV, commenced operation in 1998 for certification purpose, and due to increase demand for radiopharmaceuticals in Brazil, started F18-FDG production in 1999. Cyclotron Laboratory will be a reference Research and Developing Center in our country and will help the Brazilian and Latin-American community. It is necessary to have an adequate database to allow regular follow up and analysis of the individual dose distributions for each group involved in the cyclotron activities. These databases are also important means to assess the effectiveness of efforts in order to maintain doses ALARA and reduce inequalities. The official individual occupational dosimetry is provided by certified Laboratory of Thermoluminescent Dosimetry at IPEN-CNEN/SP. This paper describes the occupational doses distribution in Laboratory of Cyclotrons at IPEN-CNEN/SP from January, 1998 to July, 2000 and propose improvements for the future. (author)

  20. Knowledge based operation assist system for JAERI AVF cyclotron

    Agematsu, T.; Okumura, S.; Yokota, W.; Arakawa, K.; Murakami, T.; Okamura, T.

    1992-01-01

    We have developed two operation assist systems for easy and rapid operation of the JAERI AVF cyclotron. One is a knowledge based expert system guiding the sequence of parameter adjustment to inexperienced cyclotron operators. The other is a real-time simulation of the beam trajectories which are calculated from actual operating parameters. It graphically indicates feasible setting range of parameters that satisfies the acceptance of the cyclotron. These systems provide a human interface to adjust the parameters of the cyclotron. (author)

  1. Commissioning of cryogen delivery system for superconducting cyclotron magnet

    Pal, G.; Nandi, C.; Bhattacharyya, T.K.; Chaudhuri, J.; Bhandari, R.K.

    2005-01-01

    A K-500 superconducting cyclotron is being constructed at VECC Kolkata. The cryogen delivery system distributes liquid helium and liquid nitrogen to the superconducting cyclotron. Liquid helium is required to cool the cyclotron magnet and cryopanels. Liquid nitrogen is used to reduce the capacity of the helium liquefier. This paper describes the system, the current status and the commissioning experiences of cryogen delivery system for cyclotron magnet. (author)

  2. ECR ion source for variable energy cyclotron

    Bose, D K; Taki, G S; Nabhiraj, P Y; Pal, G; Dasgupta, B; Mallik, C; Das, S K; Bandopadhaya, D K; Bhandari, R K [Variable Energy Cyclotron Centre, Calcutta (India)

    1995-09-01

    Some performance characteristics of 6.4 GHz two stage ECR ion source which was under development at this centre is presented. The present ion source will facilitate acceleration of light heavy ions with the existing k=130 variable energy cyclotron. Multiply charged heavy ion (MCHI) beam from the source will also be utilized for atomic physics studies. Oxygen beam has already been used for ion implantation studies. The external injection system under development is nearing completion. Heavy ion beam from cyclotron is expected by end of 1995. (author).

  3. Cyclotron Lines in Accreting Neutron Star Spectra

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

    2009-05-01

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

  4. Radiochemistry Lab Decommissioning and Dismantlement. AECL, Chalk River Labs, Ontario, Canada

    Kenny, Stephen

    2008-01-01

    Atomic Energy of Canada (AECL) was originally founded in the mid 1940's to perform research in radiation and nuclear areas under the Canadian Defense Department. In the mid 50's The Canadian government embarked on several research and development programs for the development of the Candu Reactor. AECL was initially built as a temporary site and is now faced with many redundant buildings. Prior to 2004 small amounts of Decommissioning work was in progress. Many reasons for deferring decommissioning activities were used with the predominant ones being: 1. Reduction in radiation doses to workers during the final dismantlement, 2. Development of a long-term solution for the management of radioactive wastes in Canada, 3. Financial constraints presented by the number of facilities shutdown that would require decommissioning funds and the absence of an approved funding strategy. This has led to the development of a comprehensive decommissioning plan that is all inclusive of AECL's current and legacy liabilities. Canada does not have a long-term disposal site; therefore waste minimization becomes the driving factor behind decontamination for decommissioning before and during dismantlement. This decommissioning job was a great learning experience for decommissioning and the associated contractors who worked on this project. Throughout the life of the project there was a constant focus on waste minimization. This focus was constantly in conflict with regulatory compliance primarily with respect to fire regulations and protecting the facility along with adjacent facilities during the decommissioning activities. Discrepancies in historical documents forced the project to treat every space as a contaminated space until proven differently. Decommissioning and dismantlement within an operating site adds to the complexity of the tasks especially when it is being conducted in the heart of the plant. This project was very successful with no lost time accidents in over one hundred thousand hours worked, on schedule and under budget despite some significant changes throughout the decommissioning phases. The actual cost to decommission this building will come in under 9 million dollars vs. an estimated 14.5 million dollars. This paper will cover some of the unique aspects of dismantling a radioactive building that has seen pretty much every element of the periodic table pass through it with the client requirement focused on minimization of radioactive waste volumes

  5. A review of HTO evaporation studies at Chalk River Nuclear Laboratories

    Brown, R.M.; Barry, P.J.

    1979-01-01

    Results of the tritium evaporation and exchange studies on Perch Lake are discussed. A model is used to describe the tritium distribution in the atmospheric moisture above the lake. The model, however, underestimates the tritium content at heights above 5 m; such a discrepancy is attributed to the characteristics of the wind speed variation with height, by which vertical diffusion proceeds at somewhat greater rate than expected. Therefore, to represent the Perch Lake system adequately, a three-layer model is required, incorporating a thin laminar layer at the surface, a growing turbulent internal boundary layer and a third layer with high eddy diffusivity. Pan experiments have been used to determine the exponent n=(h-epsilon)/(1-h+Δepislon) of the equation describing the change in isotopic composition during evaporation. The agreement between the experimental and the theoretical values is good for high to middle relative humidities, but significant deviations are shown at low humidities. (author)

  6. Summary of loops in the Chalk River NRX and NRU reactors

    Nishimura, D.T.

    1980-12-01

    The design and operating parameters of the high pressure, high temperature light water loops in the NRX and NRU reactors are presented to assist experimenters reviewing these facilities for their experiments. The NRX and NRU reactor design and operating data of interest to the experimenters are also presented. (author)

  7. Chemical speciation of radionuclides in contaminant plumes at the Chalk River Nuclear Laboratories

    Champ, D.R.

    1986-01-01

    Experimental disposals of liquid and glassified wastes directly into the sands of the Perch Lake basin, Ontario, Canada, have resulted in the formation of well-defined subsurface contaminant plumes in the groundwater flow system. Using large volume water sampling techniques we have detected low concentrations of several long-lived radionuclides including isotopes of Pu, Am, Cm, Tc, I, Sr and Cs. The particulate and ionic speciation results from these studies support the conclusions of previous laboratory column studies that transport of radionuclides, particularly Cs and Pu, on particulates and/or colloids could be a significant mobilization mechanism in groundwater flow systems. We also propose, based on a comparison of the plume data with previous detailed studies on 60 Co that complexation reactions with natural as well as synthetic organic ligands can yield mobile anionic species of the actinides and lanthanides. Further detailed studies will be required to support this postulate. (author)

  8. X-ray measurement of residual stress in metals at Chalk River Nuclear Laboratories

    Winegar, J.E.

    1980-06-01

    X-ray diffraction is used at CRNL to measure residual stress in metals. This report summarizes the basic principles of stress measurement, and reviews factors affecting accuracy of measurement. The technique and equipment described were developed at CRNL to give reliable measurements. Accuracy of measurement is achieved by using fixed-count step-scanning and by computer analysis of intensity data using a cubic spline curve smoothing routine. Specific reference is made to the measurement of residual stress in Inconel-600 and Incoloy-800 boiler tubing. Because it measures stress in thin surface layers, the X-ray method can also be used to measure the depth profile of stresses. As there are no standardized procedures for measuring residual stress, this report will be useful both to those unfamiliar with the measurement of residual stress and to those already making such measurements in other laboratories. (auth)

  9. Implementing the AECL decommissioning quality assurance program at the Chalk River and Whiteshell Laboratories

    Colotelo, C.A.; Attas, E.M.; Stephens, M.E.

    2006-01-01

    This paper describes the approach and progress in developing, implementing and maintaining a quality assurance (QA) program for decommissioning at the nuclear facilities managed by Atomic Energy of Canada Limited (AECL). Decommissioning activities conducted by AECL are varied in nature, so the QA program must provide adequate flexibility, while maintaining consistency with accepted quality standards. Well-written documentation adhering to the applicable decommissioning standards is a key factor. Manager commitment and input during the writing of the documentation are also important to ensure relevance of the QA program and effectiveness of implementation. Training in the use of the quality assurance plan and procedures is vital to the understanding of the QA program. Beyond the training aspect there is a need for the quality assurance program to be supported by a QA subject expert who is able to advise the group in implementing the Quality Program with consistency over the range of decommissioning work activities and to provide continual assessment of the quality assurance program for efficiency and effectiveness, with a concomitant continuous improvement process. (author)

  10. The movement of water, arsenic, and radium at a Chalk River waste management area

    Killey, R.W.D.; Myrand, D.

    1985-05-01

    Area F is a storage site at CRNL for 119 000 tonnes of soil contaminated with low levels of arsenic and radium-226. The site was closed in 1979, and a clayey silt cover was installed in an attempt to minimize infiltration of available precipitation. Results of studies in 1980 and 1983 are used to show that the low-permeability cover has been largely ineffective in reducing infiltration. Radium has remained immobile, but arsenic is being transported by infiltrating waters into unsaturated sands beneath the contaminated soil. Iron oxyhydroxide coatings on the sand grains are sorbing the transported arsenic, and have reduced dissolved arsenic concentrations in pore waters in the sands to natural background levels

  11. Updated follow-up of long-term Chalk River employees

    Werner, M.M.; Myers, D.K.; Morrison, D.P.

    1983-08-01

    Data on the follow-up of CRNL employees who died during employment or after retirement have been updated to 1982 December 31. Updated tables on mortality for AECL participants in the 1953 NRX clean-up and in the 1958 NRU decontamination are also included in this report. Preliminary mortality data on two other groups are presented here for (a) female employees of CRNL, 1966-1982 and (b) male employees of CRNL who have accumulated lifetime occupational doses of 0.2 Sv (20 rem) or more. Data on types of fatal cancer recorded for long-term male CRNL employees over the period 1966-1982 are also given. No statistically significant increases in cancer deaths were found in any of the groups analyzed

  12. The Turnover Process at Chalk River Laboratories from Operations to Decommissioning

    Pottelberg, Paul; Tremblay, Roger

    2016-01-01

    Canadian Nuclear Laboratories (CNL) has 200 facilities that account for approximately 2 million square feet of building space. Currently there are 23 facilities undergoing various stages of Decommissioning. An additional 30 facilities are scheduled to be turned over to Decommissioning in 2016. CNL is currently restructuring to transition to a Government Owned/Contractor Operated (GoCo) organization and there will be a focus to accelerate the Decommissioning of legacy facilities on site. In the past, facilities were shutdown and left in various configurations with limited documentation or limited staff knowledge of the status of the facility at the start of Decommissioning. Recently, guidelines have been developed to ensure that any facility being turned over is put into a proper and documented safe shutdown configuration. This paper will look at CNL's process for turnover of facilities from Operations to Decommissioning and identify some of the key Lessons Learned. The turnover of nuclear facilities, administrative and support buildings, components or areas from Operations to Decommissioning needs to be documented and managed to ensure Health, Safety, Security and Environmental (HSSE) risks are identified, eliminated or effectively controlled. At CNL, the turnover document Table of Contents is: Introduction and Purpose; Facility Boundaries; Known Deficiencies; Facility Status; Shutdown Status; Hazards; System/Equipment; Drawings/Maps/Records; Significant Environmental Aspects (SEAs); Interface; and other Transfer Documentation. The transfer documentation specifically covers: - Defined boundaries of the facility, building, component or area at the time of turnover; - Identification of all deficiencies associated with the facility, building, component or area and the person, after turnover, who will be responsible for correcting them; - Confirmation of the status of the facility, building, component or area at the time of turnover with respect to: - The status of the Preliminary Decommissioning Plan (PDP). If the PDP is not current then it should be revised before Facilities Decommissioning accepts full responsibility for the facility, building, component or area; - Details of Shutdown activities (e.g. isolations, draining, decontamination, etc.); - Hazards that remain; - Significant environmental aspects and operational controls; - Details of system/equipment that remain energized or continue to perform their design function (e.g. holding tank still containing radiological liquid, etc.); - Updated drawings and equipment specifications; - Status of Engineering Change Control (ECC) that are in progress; - Safety Related Systems (SRS) list; - Fire code and building code violations or deficiencies; - Maintenance schedule; - Inventory of Nuclear Materials; - Governing documents e.g. Criticality Safety Document, Preliminary Decommissioning Plan, Environmental Assessment, Safety Analysis Report, Facility Authorization, etc.; - Outstanding Regulatory commitments; - Information on any required amendments to the Site License; and - Listing of all documentation and records to be included with the Transfer Certificate. Key responsibilities are laid out defining what is required from each party and other groups involved in the transfer of the facility. (authors)

  13. Objectives of research activities in Biology Branch, Chalk River Nuclear Laboratories, 1976

    1977-03-01

    The primary responsibility assigned to the Biology Branch within the framework of CRNL has been an active engagement in basic research related to the assessment of radiation hazards, particularly those to be expected after exposure to relatively low doses of radiation delivered at low dose-rates. The present group is characterized by a broad interest in the entire chain of events by which the initial radiation-induced changes in the living cell are translated into biological effects, with a special focus of attention on the mechanisms by which the initial damage can be largely repaired and by which the risks to man are modified under different circumstances. The basic concepts in radiation biology and risk estimates are reviewed in the light of recent literature on these topics. The current and proposed research activities of the Biology Branch are described. General and specific recommendations for future activities are given. (author)

  14. Influence of clay and silica on permeability and capillary entry pressure of chalk reservoirs in the North Sea

    Røgen, Birte; Fabricius, Ida Lykke

    2002-01-01

    specific surface area. Fifty-nine Tor and Ekofisk Formation chalk samples from five North Sea chalk reservoirs were investigated. All contain quartz and clay minerals, most commonly kaolinite and smectite, with trace amounts of illite. The contents of calcite and quartz are inversely correlated and both......)): calcite between 0.5 and 3.5, quartz about 5, kaolinite about 15, and smectite about 60....

  15. Stylolites, porosity, depositional texture, and silicates in chalk facies sediments:Ontong Java Plateau - Gorm and Tyra fields, North Sea

    Fabricius, Ida Lykke; Borre, Mai K.

    2007-01-01

    Comparison of chalk on the Ontong Java Plateau and chalk in the Central North Sea indicates that, whereas pressure dissolution is controlled by effective burial stress, pore-filling cementation is controlled by temperature. Effective burial stress is caused by the weight of all overlying water and sediments as counteracted by the pressure in the pore fluid, so the regional overpressure in the Central North Sea is one reason why the two localities have different relationships between temperatu...

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

    Oosterbeek, J.W.; Bürger, A.; Westerhof, E.

    2008-01-01

    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) bea...

  17. Building on TR-24 success. Advanced Cyclotron Systems Inc. launches a new cyclotron model

    Russell Watt; William Gyles; Alexander Zyuzin

    2015-01-01

    ACSI is designing a new 30 MeV cyclotron based on the TR-24. While minimizing changes from the proven TR-24, including maintaining the same outer dimensions, the energy of the cyclotron will be increased to 30 MeV, which will make it the most compact, non-superconducting, 30 MeV cyclotron design to date. Maximum beam current will match the TR-24 at 1 mA. With the size and footprint of a typical low energy PET cyclotron, this system will offer users a cost effective solution for a diversified facility capable of producing a wide spectrum of PET and SPECT radioisotopes for research and commercial distribution. (author)

  18. TASCC newsletter volume 7 no. 7

    Thomson, L.

    1993-07-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this July issue information is gained on solar cells as fission detectors, database conversion to VISTA, a facility report on beam production, employment equity at TASCC and insight into the cyclotron electrostatic deflector behaviour. 3 figs

  19. TASCC newsletter volume 9 no. 2

    Thomson, L.

    1995-02-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this February issue of TASCC is an update of the facility, beams to simulate the cosmic-ray environment in space, personnel changes at TASCC, modular approach to rebuilding cyclotron rf control electronics and a listing of February's experiments. 1 fig

  20. TASCC newsletter volume 5 no. 10

    Thomson, L.

    1991-10-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this October issue is a report on the commissioning of the cyclotron, a new AMS test method for Chlorine 36 beam, a facility report and operating record and a listing of experiments conducted in October

  1. Tokamak startup with electron cyclotron heating

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

    1980-04-01

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

  2. Passive cyclotron current drive for fusion plasmas

    Kernbichler, W.

    1995-01-01

    The creation of toroidal current using cyclotron radiation in a passive way is, together with the well known bootstrap current, an interesting method for stationary current drive in high-temperature fusion reactors. Here, instead of externally applied RF-waves, fish-scale like structures at the first wall help to create enough asymmetry in the self generated cyclotron radiation intensity to drive a current within the plasma. The problem of computing passive cyclotron current drive consists of actually two linked problems, which are the computation of the electron equilibrium under the presence of self-generated radiation, and the computation of the photon equilibrium in a bounded system with a distorted electron distribution. This system of integro-differential equations cannot be solved directly in an efficient way. Therefore a linearization procedure was developed to decouple both sets of equations, finally linked through a generalized local current drive efficiency. The problem of the exact accounting for the wall profile effects was reduced to the solution of a Fredholm-type integral equation of the 2 nd -kind. Based on all this an extensive computer code was developed to compute the passively driven current as well as radiation losses, radiation transport and overall efficiencies. The results therefrom give an interesting and very detailed insight into the problems related to passive cyclotron current drive

  3. Radioisotope production with a medical cyclotron

    Silvester, D.J.

    1974-01-01

    The cyclotron of Hammersmith hospital in England was completed and started the operation in 1955. The feature is in its design operable at high beam current, reaching 500μA in internal beam and 300μA in external beam. In 1960's, twelve nuclides of radioactive pharmaceuticals were produced with the cyclotron. C-11, N-13 and O-15 have been used in the form of radioactive gases such as CO or H 2 O to test lung functions. F-18 has been used for bone scanning. K-43 is employed in the research of electrolyte balancing together with Na-24 and Br-77. Fe-52 is utilized in iron ion researches as a tracer. Cs-129 is highly evaluated as an isotope for imaging cardiac clogging part. Radioisotopes must be much more used in the examination of in vivo metabolic function. For this purpose, peculiarly labelled compounds should be further developed. It is welcome that the persons paying attention to the medical prospect of cyclotrons are increasing. The author hopes to continue his endeavour to find new products made with the cyclotron for human welfare. (Wakatsuki, Y.)

  4. Ion-cyclotron instability in magnetic mirrors

    Pearlstein, L.D.

    1987-01-01

    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

  5. The Data Cyclotron query processing scheme

    Goncalves, R.; Kersten, M.

    2011-01-01

    A grand challenge of distributed query processing is to devise a self-organizing architecture which exploits all hardware resources optimally to manage the database hot set, minimize query response time, and maximize throughput without single point global coordination. The Data Cyclotron

  6. The Data Cyclotron query processing scheme.

    R.A. Goncalves (Romulo); M.L. Kersten (Martin)

    2011-01-01

    htmlabstractA grand challenge of distributed query processing is to devise a self-organizing architecture which exploits all hardware resources optimally to manage the database hot set, minimize query response time, and maximize throughput without single point global coordination. The Data Cyclotron

  7. Cyclotron-based neutron source for BNCT

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

    2013-04-19

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

  8. <600> MeV synchro-cyclotron

    CERN PhotoLab

    1971-01-01

    One of the 14 pancakes of the new magnet coils for the 600 MeV synchro-cyclotron which were wound and coated with epoxy resin on the CERN site. These new coils will replace the present ones which have been in use for more than 14 years but are now showing signs of deteriorations.

  9. Helical axial injection concept for cyclotrons

    Hudson, E.D.

    1981-01-01

    A concept for an external beam injection system using a helical beam path centered on the cyclotron axis is described. This system could be used to couple two accelerator stages, with or without intermediate stripping, in cases where conventional axial injection or radial injection are not practical.

  10. Helical axial injection concept for cyclotrons

    Hudson, E.D.

    1981-01-01

    A concept for an external beam injection system using a helical beam path centered on the cyclotron axis is described. This system could be used to couple two accelerator stages, with or without intermediate stripping, in cases where conventional axial injection or radial injection are not practical

  11. Automated cyclotron tuning using beam phase measurements

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

    2006-01-01

    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

  12. A visual assistance environment for cyclotron operation

    Okamura, Tetsuya; Murakami, Tohru; Agematsu, Takashi; Okumura, Susumu; Arakawa, Kazuo.

    1993-01-01

    A computer-based operation system for a cyclotron which assists inexperienced operators has been developed. Cyclotron start-up operations require dozens of adjustable parameters to be finely tuned to maximize extracted beam current. The human interfaces of the system provide a visual environment designed to enhance beam parameter adjustments. First, the mental model of operators is analyzed. It is supposed to be composed of five partial mental models: beam behavior model, feasible setting regions model, parameter sensitivity model, parameter mutual relation model, and status map model. Next, based on these models, three visual interfaces are developed, i.e., (1) Beam trajectory is rapidly calculated and graphically displayed whenever the operators change the cyclotron parameters. (2) Feasible setting regions (FSR) of the parameters that satisfy the cyclotron's beam acceptance criteria are indicated. (3) Search traces, being a historical visual map of beam current values, are superimposed on the FSRs. Finally, to evaluate system effectiveness, the search time required to reach maximum beam current conditions was measured. In addition, system operability was evaluated using written questionnaires. Results of the experiment showed that the search time to reach specific beam conditions was reduced by approximately 65% using these interfaces. The written questionnaires survey showed the operators highly evaluate system operability. (author)

  13. Microwave power coupling with electron cyclotron resonance ...

    600 W microwave power with an average electron density of ∼ 6 × 1011 cm. −3 ... the angular frequency of the cyclotron motion, e is the electron charge, m is the mass of .... is also suitable for ECR plasma-based applications like high-quality ...

  14. Development of HM12 cyclotron for PET

    Morita, Takuzo; Kawama, Tetsuo; Fujii, Kazuo

    2000-01-01

    In Japan, there are at present more than 30 PET (Positron Emission Tomography) facilities. The movements of medical insurance application to the PET diagnosis using [ 18 F] FDG (2-[ 18 F]-fluoro-2-deoxy-glucose) by the Ministry of Health and Welfare are being enhanced by PET related people. Therefore, more clinical centers using PET system are expected to be built in the near future. HM12 cyclotron was developed to meet such market demands for PET, and the prototype machine has been rent to Cyclotron Radio Isotope Center (CYRIC) of Tohoku University since Oct. 1998 for their use of clinical research with positron emitters like 11 C, 13 N, 15 O and 18 F. We got many technical data of HM12 Cyclotron on the clinical base. The data was enough to establish the reliability of HM12 system operation under the clinical condition. The first commercial product of HM12 Cyclotron was delivered to National Cancer Center in March 2000. The final performance test will be finished by the end of June 2000. (author)

  15. Electron cyclotron emission from thermal plasmas

    Fidone, I.; Granata, G.

    1978-02-01

    Electron cyclotron radiation from a warm inhomogeneous plasma is investigated. A direct calculation of the emissive power of a plasma slab is performed using Rytov's method and the result is compared with the solution of the transfer equation. It is found that, for arbitrary directions of emission, the two results differ, which reflects the fact that Kirchhoff's law is not generally obeyed

  16. Electron cyclotron heating and associated parallel cooling

    Rapozo, C. da C.; Assis, A.S. de; Busnardo Neto, J.

    1990-01-01

    It has been experimentally observed that during the electron-cyclotron heating the electron longitudinal temperature drops as the perpendicular temperature increases. The experiment was carried in a linear mirror machine with a low density (10 10 cm -3 ) weakly ionized (< 1.0 %) plasma. (Author)

  17. On Resonant Heating Below the Cyclotron Frequency

    Chen, Liu; Lin, Zhihong; White, R.

    2001-01-01

    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

  18. Emergency situation in a medical cyclotron facility

    Kumar, Rajeev; Bhat, M.K.; Singh, D.K.; Pthania, B.S.; Pandit, A.G.; Jacob, M.J.

    2010-01-01

    Full text: Medical cyclotron is a particle accelerator used in producing short lived radioisotopes such as 18 F, 11 C, 15 O, 13 N, 18 F-2 gas etc. Positron Emission Tomography (PET) is a nuclear imaging modality that has rapidly gained favour. 18 F-FDG is the most widely used radiopharmaceutical with a half-life of 109.8 min. Having more than five years experience in this field we face lots of emergency conditions in the medical cyclotron facility. On the basis of harm we have divided in to three categories i.e. Harm of (a) working personnel, (b) Equipment and (c) environment. Radioactive gas leak and Target foil rupture is considered as the major emergency situations during medical cyclotron operations because there is a potential of over exposure to the working personnel. Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions. It is found that the induced activity in the target foil increases with its successive usages. Recommendations have also been made to reduce personal exposure while handling the radioactive gas leak and target foil rupture conditions

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

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

    1992-01-01

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

  20. Currents driven by electron cyclotron waves

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

    1981-07-01

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

  1. Tokamak startup with electron cyclotron heating

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

    1980-04-01

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

  2. Cyclotron resonance cooling by strong laser field

    Tagcuhi, Toshihiro; Mima, Kunioka

    1995-01-01

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

  3. Experimental Study of Bacterial Penetration into Chalk Rock: Mechanisms and Effect on Permeability

    Halim, Amalia Yunita; Shapiro, Alexander; Eliasson Lantz, Anna

    2014-01-01

    Bacterial selective plugging is one of the mechanisms through which microorganisms can be applied for enhanced oil recovery, as bacteria can plug the water-swept zones of a reservoir, thus altering the flow paths and improving sweep efficiency. However, complete understanding of the penetration...... behavior of bacteria is lacking, especially in chalk formations where characteristic pore throat sizes are comparable with the sizes of bacterial cells. In this study, two bacterial strains, Bacillus licheniformis 421 (spore-forming) and Pseudomonas putida K12 (non-spore forming) were used to investigate...... the penetration of bacteria into chalk and its effect on permeability reduction. The core plugs were produced from Stevns Klint outcrop with low permeability (2–4 mD) and with pore sizes comparable to bacterial sizes. Both types of bacteria were able to penetrate and to be transported through the cores to some...

  4. Investigation of spore forming bacterial flooding for enhanced oil recovery in a North Sea chalk Reservoir

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Eliasson Lantz, Anna

    2015-01-01

    Little has been done to study microbial enhanced oil recovery (MEOR) in chalk reservoirs. The present study focuses on core flooding experiments designed to see microbial plugging and its effect on oil recovery. A pressure tapped core holder was used for this purpose. A spore forming bacteria...... Bacillus licheniformis 421 was used as it was shown to be a good candidate in a previous study. Bacterial spore can penetrate deeper into the chalk rock, squeezing through the pore throats. Our results showed that injection of B. licheniformis 421 as a tertiary oil recovery method, in the residual oil...... saturation state, was able to produce additionally 1.0-2.3% original oil in place (OOIP) in homogeneous cores and 6.9-8.8% OOIP in heterogeneous cores. In addition, the pressure gradient was much higher in the heterogeneous cores, which confirms that bacterial selective plugging plays an important role...

  5. Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass

    Hansen, H.K.; Kristensen, I.V.; Ottosen, L.M.; Villumsen, A. [Dept. of Geology and Geotechnical Engineering, The Technical Univ. of Denmark, Lyngby (Denmark)

    2001-07-01

    Electroosmotic dewatering has been tested in laboratory cells for 4 different porous materials: chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge from enzyme production. In all cases it was possible to remove water when passing electric DC current through the material. Casagrande's coefficients for the three materials where determined at different water contents. In the electroosmotic experiments shown in this work chalk can be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM. The process was not optimised indicating that higher dry matter contents could be achieved. (orig.)

  6. Burial diagenesis of deep sea chalk as reflected in Biot's coefficient

    Fabricius, Ida Lykke; Alam, Mohammad Monzurul

    2013-01-01

    to limestone as burial increases and porosity decreases. The porosity decrease is accompanied by an increasing velocity to elastic waves, and consequently a decreasing Biot's coefficient, as estimated from velocity and density of core samples. When the effective burial stress is normalized to total horizontal....... In the ooze, we find that the natural compaction causes an increasing stress on grain contact area, indicating that the ooze particles become strongly strained. In the chalk section, contact cement is probably the reason why particles become less strained as porosity declines. In the limestone, stress...... on particles apparently is low and not correlated with porosity, probably because the pore-filling cementation in this interval causes Biot's coefficient to decline as burial increases. Limestone from the water zone of the North sea Chalk Group follows the same stress trend as deep sea limestone. These results...

  7. Acidity of sphagnum and its relation to chalk and mineral salts

    Skene, M

    1915-01-01

    In addition to the criticism and elucidation of various other points, the chief conclusions which may be drawn from the preceding pages are: (1) There is a variation in acidity and in sensitiveness to chalk between the different species of sphagnum. (2) There is a correlation between degree of acidity and degree of sensitiveness. (3) The connection between the two is indirect, not direct. (4) The sphagna thrive in acid solutions: the injurious effect of chalk, and of alkalies in general, is due to the substitution of an alkaline for an acid reaction. (5) Mineral solutions are generally physiologically harmless, but may be ecologically harmful. (6) The sphagna do actually utilize in growth bases held absorbed by the acid compounds of the cell-walls.

  8. Strength and Biot's coefficient for high-porosity oil- or water-saturated chalk

    Andreassen, Katrine Alling

    . The Biot coefficient states the degree of cementation or how the pore pressure contributes to the strain resulting from an external load for a porous material. It is here calculated from dynamic measurements and correlated with the strength of outcrop chalk characterized by the onset of pore collapse...... during hydrostatic loading. The hypothesis is that the Biot coefficient and the theory of poroelasticity may cover the fluid effect by including the increased fluid bulk modulus from oil to water. A high number of test results for both oil- and water-saturated high-porosity outcrop chalk show correlation......In the petroleum industry it is relevant to know the Biot coefficient for establishing the effective stresses present in both the overburden and for the reservoir interval. When depleting a reservoir it is important to estimate the settlement through the strain imposed by the effective stress. Also...

  9. Elasticity and electrical resistivity of chalk and greensand during water flooding with selective ions

    Katika, Konstantina; Alam, Mohammad Monzurul; Alexeev, Artem

    2018-01-01

    is water-wet after flooding. Greensand remained mixed wet throughout the experiments. Electrical resistivity data are in agreement with this interpretation. The electrical resistivity data during flooding revealed that the formation brine is not fully replaced by the injected water in both chalk......Water flooding with selective ions has in some cases lead to increased oil recovery. We investigate the physical processes on a pore scale that are responsible for changes in petrophysical and mechanical properties of four oil-bearing chalk and four oil-bearing greensand samples caused by flooding...... with brines containing varying amounts of dissolved NaCl, Na2SO4, MgCl2 and MgSO4. Ultrasonic P-wave velocity and AC resistivity measurements were performed prior to, during and after flow through experiments in order to identify and quantify the processes related to water flooding with selective ions. Low...

  10. Origin of channel systems in the Upper Cretaceous chalk group of the Paris Basin

    Esmerode, E. V.; Surlyk, Finn

    2009-01-01

    the presence of at least two distinct intra-chalk discordant reflections: a Top Santonian and a Mid-Campanian reflection. These reflections are in places associated with up to 120-m-deep channel-like structures trending preferentially N-S and NW-SE. The Mid-Campanian reflection is also sporadically associated...... with a massive secondary dolomite layer, the thicknesses of which may reach 110 m. Diagenesis does not seem to account for the formation of the discordant reflections, as there is neither a one-to-one relationship between the dolomite and discordant reflections, nor are there signs of systematic collapse...... is suggested due to the uninterrupted deep-marine chalk facies below and above both unconformities, and the unrealistically large sea-level drop of more than 200 m, which would be necessary for subaerial exposure of the central Paris Basin during the Campanian. The channels are oriented parallel to the margins...

  11. Investigated Miscible CO2 Flooding for Enhancing Oil Recovery in Wettability Altered Chalk and Sandstone Rocks

    Tabrizy, Vahid Alipour

    2012-07-01

    The thesis addresses oil recovery by miscible CO2 flooding from modified sandstone and chalk rocks. Calcite mineral surface is modified with stearic acid (SA) and asphaltene, and the silicate mineral surfaces are modified with N,N-dimethyldodecylamine (NN-DMDA) and asphaltene. The stability of adsorbed polar components in presence of SO4 2- and Mg2 + ions is also investigated. Recovery from sandstone cores is consistently lower than that from chalk cores saturated with the same oil and flooded with CO2 at all miscible flooding conditions. This may be due to the larger permeability contrasts in sandstone cores, which promote the fingering phenomenon. Miscible CO2 flooding for chalk and sandstone cores with distilled water, as initial water saturation, shows also lower oil recovery than cores saturated with different ions. At higher miscible flooding conditions, higher oil recovery is obtained. However, presence of light components (such as C1 or C3) in oil reduced the recovery. Oil recovery in presence of methane (C1) is lower than that in presence of methane and propane (C1/C3). A ternary diagram was constructed in order to understand the CO2 flooding mechanism(s) at the different flooding conditions and in presence of light components. The side effect of the flooding with CO2 is the probability for asphaltene deposition. An approach based on solubility parameter in the liquid, is used to assess the risk for asphaltene deposition during CO2 miscible flooding. The light components (C1/C3) and higher flooding conditions enhanced the risk for asphaltene instability. It is also shown higher amount of asphaltene deposition in chalk cores than that in sandstone cores at similar miscibility conditions.(au)

  12. TASCC newsletter volume 8 no. 5

    Thomson, L

    1994-05-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this May issue of TASCC is an update of the facility, a visit by the Nuclear Physics Technical Review Committee, sizing of meteors, Deep River Science Academy on TASCC projects and a listing of May`s experiments. 2 figs.

  13. Directory of cyclotrons used for radionuclide production in Member States

    NONE

    1998-03-01

    The directory of cyclotrons used for radionuclide production is an update of the data base on cyclotrons that was compiled in 1983 by the International Atomic Energy Agency. The directory contains technical, utilization and administrative information supplied to the IAEA as of October 1997. The directory was prepared through information collected by questionnaires sent to institutions that either have a cyclotron, or that were identified to be in the process of installation of a cyclotron. The directory contains 206 entries for cyclotrons operating in 34 Member States. The largest concentration of cyclotrons for radionuclide production are located in the United States of America (66), Japan (33) and Germany (22). The largest number of cyclotrons for a single country is the United States of America. The expansion in number of cyclotrons during the last decade has been driven by the advent of advances in medical imaging instrumentation (PET, SPET and more recently 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons from several companies that manufacture cyclotrons; and recent decisions that {sup 15}O-oxygen PET studies in Japan, and {sup 18}F-FDG PET studies in Germany are eligible for reimbursement by government or insurance companies.

  14. Directory of cyclotrons used for radionuclide production in Member States

    1998-03-01

    The directory of cyclotrons used for radionuclide production is an update of the data base on cyclotrons that was compiled in 1983 by the International Atomic Energy Agency. The directory contains technical, utilization and administrative information supplied to the IAEA as of October 1997. The directory was prepared through information collected by questionnaires sent to institutions that either have a cyclotron, or that were identified to be in the process of installation of a cyclotron. The directory contains 206 entries for cyclotrons operating in 34 Member States. The largest concentration of cyclotrons for radionuclide production are located in the United States of America (66), Japan (33) and Germany (22). The largest number of cyclotrons for a single country is the United States of America. The expansion in number of cyclotrons during the last decade has been driven by the advent of advances in medical imaging instrumentation (PET, SPET and more recently 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons from several companies that manufacture cyclotrons; and recent decisions that 15 O-oxygen PET studies in Japan, and 18 F-FDG PET studies in Germany are eligible for reimbursement by government or insurance companies

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

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

    2017-04-01

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

  16. Radiation protection of cyclotron vault with maze in PET Cyclotron Center

    Fueloep, Marko

    2003-01-01

    The PET Cyclotron center (PCC) is a complex for production, research and application of positron radiopharmaceuticals for PET (Positron Emission Tomography), which was commissioned this year (2004) in Bratislava, Slovak Republic. Positron radionuclides are produced by 18/9 MeV proton/deuteron cyclotron CYCLONE 18/9. Radiation protection of personnel and inhabitants against ionizing radiation in the PCC is solved with regard to the ICRP recommendations and Slovak regulatory system, protection rules and criteria and optimization of radiation protection. In the article comparisons of calculated and measured neutron and gamma dose equivalent rates around the CYCLONE 18/9 and at various points behind the shielding of cyclotron vault with maze are presented. Description of the CYCLONE 18/9 as a source of angular distribution of neutron energy spectra (production of 18 F was considered) was simulated by Monte Carlo code MCNPX. Code MCNP4B was used for shielding calculation of cyclotron vault with maze. Neutron energy spectra behind the shielding were measured by Bonner spectrometer. The values of neutron dose equivalent, which were calculated and measured around the CYCLONE 18/9 and at various points behind the shielding of cyclotron vault with maze, are within the range of factor 2. (authors)

  17. The Cyclotron Center of the Slovak Republic

    Podhorsky, D.; Ruzicka, J.; Macasek, F.; Makaiova, I.; Saro, S.; Kristiak, J.; Fulup, M.

    2001-01-01

    The Cyclotron Center of the Slovak Republic was established at the beginning of August 1999 - within the Slovak-Office of Standards, Metrology and Testing (SOSMT), in Bratislava, Slovak Republic. It will have two cyclotrons - a large heavy and light cyclotron DC-72, which will be constructed by the Joint Institute for Nuclear Research (JINR), Dubna, Russian Federation, and a small commercial light ion cyclotron IBA 18/9. The heavy ion source of the electron resonance type (DECRS-2M) will be used for low and medium energy experiments in physics. The small electron accelerator is planned for different applications, including improving the properties of plastics, increasing the resistance of cables to fire and temperature, the sterilization of medical disposables in the CC SR. The main purpose of the Cyclotron Center of the Slovak Republic (CC SR) is to catch the present approach and trends in the area of improving of inhabitants life and health quality using the progressive technology, which is introduced by bringing into practice of the physical equipment - accelerators, producing beams of high energy particles. Experts of nuclear physics and of the related branches have no experimental basis in Slovakia, as after dissolution of the former the Czech and Slovak Federal Republic all bigger nuclear equipment were left in the Czech Republic. The Slovak Republic is one of the European countries where cancer and cardiovascular diseases have a rapidly increasing tendency (the rate of new oncological cases is approximately 20,000/year at the population of 5 million inhabitants) - early diagnostics of population is necessary to be updated urgently. The Slovak Republic use a great part of electricity (about 60 %) from its own nuclear power stations and thus it is in need of education of rising generations of experts from different nuclear fields. The Government of the Slovak republic on June 18, 1996 approved the strategic aim of building up the Cyclotron Laboratory at the

  18. Research and education by SF cyclotron facility

    1992-04-01

    This report represents the current activities in research and education using the cyclotron facility and related apparatus which are supported by Nuclear Physics Division and this is a continuation of INS-T-466 (1986, December). In this version an iron-free β-ray spectrometer and a cooler-synchrotron (TARN II) are briefly described also in the first chapter. The second chapter explains experimental programs performed in the last 5 years. The third chapter gives the number of publications on researches performed in 1975-1991, and also gives twelve topics obtained from the cyclotron and the β-ray spectrometer in recent 5 years. The last chapter provides the whole list of the works for Doctor and Master theses performed at the facility in the last 10 years. (J.P.N.)

  19. MMS Observations of Harmonic Electromagnetic Cyclotron Waves

    Usanova, M.; Ahmadi, N.; Ergun, R.; Trattner, K. J.; Fuselier, S. A.; Torbert, R. B.; Mauk, B.; Le Contel, O.; Giles, B. L.; Russell, C. T.; Burch, J.; Strangeway, R. J.

    2017-12-01

    Harmonically related electromagnetic ion cyclotron waves with the fundamental frequency near the O+ cyclotron frequency were observed by the four MMS spacecraft on May 20, 2016. The wave activity was detected by the spacecraft on their inbound passage through the Earth's morning magnetosphere during generally quiet geomagnetic conditions but enhanced solar wind dynamic pressure. It was also associated with an enhancement of energetic H+ and O+ ions. The waves are seen in both magnetic and electric fields, formed by over ten higher order harmonics, most pronounced in the electric field. The wave activity lasted for about an hour with some wave packets giving rise to short-lived structures extending from Hz to kHz range. These observations are particularly interesting since they suggest cross-frequency coupling between the lower and higher frequency modes. Further work will focus on examining the nature and role of these waves in the energetic particle dynamics from a theoretical perspective.

  20. Neutron radiography with the cyclotron, 3

    Hiraoka, Eiichi; Fujishiro, Masatoshi; Tsujii, Yukio

    1985-01-01

    Neutron radiography is well recognized as a powerful tool in nondestructive testing, but not widely used yet owing to lack of high intense thermal neutron source convenient for practical use. A new neutron radiograph facility, utilizing a sub-compact cyclotron as neutron source and equipped with vertical and horizontal irradiation ports, is presented in this article. A series of experiment, prior to its construction, was conducted using beams of a variable energy cyclotron at Tohoku University to investigate the characteristics of thermal neutron obtained, from 9 Be (p, n) reaction and thermalized by elastic scattering process. This article describes a computer simulation of neutron moderator to analyze conditions getting maximal thermal neutron flux. Some of practical neutron radiograph examination of aero-space components and museum art objects of classic bronze mirror are also presented together with an attempt realizing real time imaging technique. (author)

  1. Research activities by INS cyclotron facility

    1992-06-01

    Research activities made by the cyclotron facility and the related apparatuses at Institute for Nuclear Study (INS), University of Tokyo, have been reviewed in terms of the associated scientific publications. This publication list, which is to be read as a continuation of INS-Rep.-608 (October, 1986), includes experimental works on low-energy nuclear physics, accelerator technology, instrumental developments, radiation physics and other applications in interdisciplinary fields. The publications are classified into the following four categories. (A) : Internal reports published in INS. (B) : Publications in international scientific journals on experimental research works done by the cyclotron facility and the related apparatuses at INS. Those made by outside users are also included. (C) : Publications in international scientific journals on experimental low-energy nuclear physics, which have been done by the staff of INS Nuclear Physics Division using facilities outside INS. (D) : Contributions to international conferences. (author)

  2. New design for a medical cyclotron

    Wilson, M

    1985-12-01

    The Oxford Instruments Group PLC, have designed a 30 MeV energy proton cyclotron incorporating a super-conducting magnet and a novel RF accelerating cavity. The energy range is suitable for the production of isotopes such as /sup 67/Ga, /sup 111/In, /sup 123/I and /sup 201/Tl, and the short lived isotopes of carbon, nitrogen, oxygen and fluorine for use in Positron Emmission Tomography (PET). A new magnet and RF cavity design permit a considerable power and weight reduction and a compact size (1.5m dia x 1.9m high), allowing the cyclotron to be transported to a shielded site as an assembly after factory testing. A method of beam extraction has been adopted which minimises activation of the accelerator components and so allows hands on maintenance to be carried out when required.

  3. Matching of ion sources to cyclotron inflectors

    Baartman, R.

    1988-06-01

    In general, cyclotron inflectors strongly couple the two transverse subspaces. This leads to a growth in emittance projections for a beam with no initial correlation between the two transverse subspaces. Only in the case of the Mueller (hyperboloid) inflector is there no emittance growth. We have made calculations using an optimization routine to match a given beam through the axial injection system. We find that in the limit where all the emittance is due to a beam's axial angular momentum (for example, from an ECR source), matching with no emittance growth is possible even in the case of mirror or spiral inflectors. Moreover, any one of the two transverse emittances circulating in the cyclotron can be made smaller than the source emittance while maintaining the sum of the emittances constant. This is achieved by rotating the matching quadrupoles with respect to the inflector and retuning

  4. Cyclotrons as Drivers for Precision Neutrino Measurements

    Alonso, J.; Barletta, W. A.; Winslow, L. A.; Shaevitz, M. H.; Spitz, J.; Conrad, J. M.; Toups, M.; Adelmann, A.

    2014-01-01

    As we enter the age of precision measurement in neutrino physics, improved flux sources are required. These must have a well defined flavor content with energies in ranges where backgrounds are low and cross-section knowledge is high. Very few sources of neutrinos can meet these requirements. However, pion/muon and isotope decay-at-rest sources qualify. The ideal drivers for decay-at-rest sources are cyclotron accelerators, which are compact and relatively inexpensive. This paper describes a scheme to produce decay-at-rest sources driven by such cyclotrons, developed within the DAEδALUS program. Examples of the value of the high precision beams for pursuing Beyond Standard Model interactions are reviewed. New results on a combined DAEδALUS—Hyper-K search for CP violation that achieve errors on the mixing matrix parameter of 4° to 12° are presented

  5. Hybrid simulation of electron cyclotron resonance heating

    Ropponen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)], E-mail: tommi.ropponen@phys.jyu.fi; Tarvainen, O. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Suominen, P. [CERN Geneve 23, CH-1211 (Switzerland); Koponen, T.K. [Department of Physics, University of Jyvaeskylae, Nanoscience Center, P.O. Box 35, FI-40014 (Finland); Kalvas, T.; Koivisto, H. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)

    2008-03-11

    Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron density profiles and uses right hand circularly polarized (RHCP) electromagnetic waves to simulate electron heating in ECRIS plasma.

  6. Electron cyclotron emission from the PLT tokamak

    Hosea, J.; Arunasalam, V.; Cano, R.

    1977-07-01

    Experimental measurements of electron cyclotron emission from the PLT tokamak plasma reveal that black-body emission occurs at the fundamental frequency. Such emission, not possible by direct thermal excitation of electromagnetic waves, is herein attributed to thermal excitation of electrostatic (Bernstein) waves which then mode convert into electromagnetic waves. The local feature of the electrostatic wave generation permits spatially and time resolved measurements of electron temperature as for the second harmonic emission

  7. Use of maze in cyclotron hoppers

    Fernandes, Fernando A.; Alves, Juliano S.; Fochesatto, Cintia; Cerioli, Luciane; Borges, Joao Alfredo; Gonzalez, Delfin; Silva, Daniel C.

    2013-01-01

    Introduction: the increasing number of cyclotrons in Brazil due to constitutional amendment 49 /06 that enabled the production of radiopharmaceuticals with a short half - life by private companies. The radionuclides used for PET - CT require production centers near or within the diagnostic centers. In order to minimize maintenance and operating risks, gaining efficiency, our facility was the first in Brazil to use the access to a cyclotron bunker via maze, rather than armored door stopper type. Materials: the design calculations were based on the Monte Carlo method (MCNP5 - Monte Carlo N-Particletransportcode version 5). At the ends of the labyrinth are installed a door of polyethylene, for thermalization of neutrons, and other of wood for limiting access. Both legs of the maze have wall thickness of 100cm. In inspection Brazilian CNEN realize measures of dose rate for neutrons and gamma 9 points: 7 around the bunker, 1 over the bunker and 1 in the exhaust with the cyclotron operating with maximum load, double beam of 50uA for 2 hours. After commissioning were carried out around the bunker, the following measures: cumulative dose in three months with dosimeters for neutron rate dose with a gas proportional detector type filled with 3 He and polyethylene neutron moderator and dose rate with a Geiger - Mueller detector for gamma radiation. Readings with neutron detectors were classified as background radiation and dose rates were always below the limits established in standard EN 3.01, and the calculation of the predicted regardless of the intensity of irradiation inside the bunker. Conclusion: the use of labyrinths as a way to access the bunkers cyclotron has been shown to be effective as the radiation shielding and efficient by allowing quick and easy access, virtually eliminating the maintenance

  8. The superconducting separated orbit cyclotron TRITRON

    Trinks, U.

    1984-01-01

    At the Munich 13 MV-Tandem Laboratory the TRITRON is under development, which will be the prototype of a superconducting separated orbit cyclotron for acceleration of heavy ions with 0.04 or approx.20) of the revolution frequency. Thus the frequency range for acceleration of ions with different revolution frequency can be kept small (+-3%). The magnets as well as the cavities are contained in the same cavity. (orig.)

  9. DAISY - the Oslo Cyclotron data acquisition system

    Ramsoey, T.

    1991-08-01

    The new CACTUS multidetector system for the Oslo Cyclotron consists of 8 particle telescopes, 28 NAI detectors and 2 Ge detectors. Each detector gives rise to one energy parameter and one time parameter. Thus, a total of 80 parameters are present. The counting rate is 100 kByte/s for the highest beam intensities. A new data acquisition system, DAISY, satisfying these demands has been designed. The present report is intended as a complete technical manual for the new system. 24 refs

  10. Electron cyclotron resonance multiply charged ion sources

    Geller, R.

    1975-01-01

    Three ion sources, that deliver multiply charged ion beams are described. All of them are E.C.R. ion sources and are characterized by the fact that the electrons are emitted by the plasma itself and are accelerated to the adequate energy through electron cyclotron resonance (E.C.R.). They can work without interruption during several months in a quasi-continuous regime. (Duty cycle: [fr

  11. Cyclotron heating rate in a parabolic mirror

    Smith, P.K.

    1984-01-01

    Cyclotron resonance heating rates are found for a parabolic magnetic mirror. The equation of motion for perpendicular velocity is solved, including the radial magnetic field terms neglected in earlier papers. The expression for heating rate involves an infinite series of Anger's and Weber's functions, compared with a single term of the unrevised expression. The new results show an increase of heating rate compared with previous results. A simple expression is given for the ratio of the heating rates. (author)

  12. First experimental observation of cyclotron superradiance

    Ginzburg, N S; Zotova, I V; Sergeev, A S; Konoplev, I V [Russian Academy of Sciences, Nizhny Novgorod (Russian Federation). Inst. of Applied Physics; Shpak, V G; Yalandin, M I; Shunajlov, C A; Ulmaskulov, M P [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of Electrophysics

    1997-12-31

    The first experimental observation of cyclotron superradiance from subnanosecond high-current electron bunches moving through waveguide systems is reported. Ultrashort microwave K{sub {alpha}} band pulses with a power of 200 kW and duration less than 0.5 ns were observed in the regime of group synchronism when the electron bunch drift velocity coincided with the group velocity of the electromagnetic waves. (author). 2 figs., 13 refs.

  13. Electron cyclotron emission measurement in Tore Supra

    Javon, C.

    1991-06-01

    Electron cyclotron radiation from Tore-Supra is measured with Michelson and Fabry-Perot interferometers. Calibration methods, essential for this diagnostic, are developed allowing the determination of electron temperature in the plasma. In particular the feasibility of Fabry-Perot interferometer calibration by an original method is demonstrated. A simulation code is developed for modelling non-thermal electron population in these discharges using measurements in non-inductive current generation regime [fr

  14. Modular beam diagnostics instrument design for Cyclotrons

    Chaddha, N.; Bhole, R.B.; Sahoo, S.; Nandy, P.P.; Pal, S.

    2012-01-01

    The Cyclotrons at VECC, Kolkata i.e. Room Temperature Cyclotron (RTC) and Superconducting Cyclotron (SCC) comprise of internal and external Beam Diagnostic systems. These systems provide the beam developer with position, intensity, beam profile, a visual impression of the size and shape of ion beam, and operational control over diagnostic components like 3-finger probe, Beam Viewer probe, Deflector probe, Faraday cup, X-Y slit, Beam viewer etc. Automation of these components was initially done using customised modules for individual sub-system. An expansion of this facility and various levels of complexity demand modular design to cater easy modification and upgradation. The overall requirements are analysed and modular cards are developed based on basic functionalities like valve operation, probe/slit/viewer control, position read-out, Interlock, aperture control of beam line and communication. A 32-bit Advanced RISC Machine (ARM) based card with embedded EPICS is chosen as the master controller and FPGA/microcontroller is used for functional modules. The paper gives a comprehensive description of all modules and their integration with the control system. (author)

  15. Ion Cyclotron Heating on Proto-MPEX

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

    2016-10-01

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

  16. Electron cyclotron heating (ECH) of tokamak plasmas

    Hoshino, Katsumichi

    1990-01-01

    Electron cyclotron heating (ECH) is one of the intense methods of plasma heating, and which utilizes the collisionless electron-cyclotron-resonance-interaction between the launched electromagnetic waves (called electron cyclotron waves) and electrons which are one of the constituents of the high temperature plasmas. Another constituent, namely the ions which are subject to nuclear fusion, are heated indirectly but strongly and instantly (in about 0.1 s) by the collisions with the ECH-heated electrons in the fusion plasmas. The recent progress on the development of high-power and high-frequency millimeter-wave-source enabled the ECH experiments in the middle size tokamaks such as JFT-2M (Japan), Doublet III (USA), T-10 (USSR) etc., and ECH has been demonstrated to be the sure and intense plasma heating method. The ECH attracts much attention for its remarkable capabilities; to produce plasmas (pre-ionization), to heat plasmas, to drive plasma current for the plasma confinement, and recently especially by the localization and the spatial controllability of its heating zone, which is beneficial for the fine controls of the profiles of plasma parameters (temperature, current density etc.), for the control of the magnetohydrodynamic instabilities, or for the optimization/improvement of the plasma confinement characteristics. Here, the present status of the ECH studies on tokamak plasmas are reviewed. (author)

  17. Nonlinear cyclotron absorption and stimulated scattering

    Chung, T.H.

    1986-01-01

    In electron cyclotron resonance heating (ECRH), wave sources heating a plasma linearly with respect to intensity; but as the intensity of ECRH gets larger, there might appear nonlinear effects that would result in cutoff of net absorption. This thesis uses quantum mechanical theory to derive a threshold microwave intensity for nonlinear absorption. The quantum mechanical theory estimates that the threshold microwave intensity for nonlinear absorption is about 10 5 watts/cm 2 for a microwave heating experiment (T/sub e/ = 100 ev, λ = 3,783 cm, B = 2.5 kG). This value seems large considering the present power capabilities of microwave sources (10 2 ∼ 10 3 watts/cm 2 ), but for a low temperature plasma, this threshold will go down. There is another nonlinear phenomenon called stimulated cyclotron scattering that enhances photon scattering by electrons gyrating in a magnetic field. This is expected to prevent incoming photons from arriving at the central region of the fusion plasma, where absorption mainly takes place. Theory based on a photon transport model predicts that the threshold intensity for the stimulated cyclotron scattering is about 10 4 watts/cm 2 for the plasma parameters mentioned above. This value seems large also, but a longer wavelength of microwaves and a larger magnitude magnetic field, which will be the case in reactor type facilities, will lower the threshold intensity to levels comparable with the currently developed microwave sources

  18. Transparency of Magnetized Plasma at Cyclotron Frequency

    G. Shvets; J.S. Wurtele

    2002-03-01

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

  19. Improving cancer treatment with cyclotron produced radionuclides

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

    1992-01-01

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

  20. Operation of a quasioptical electron cyclotron maser

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

    1984-12-01

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

  1. TFTR vertically viewing electron cyclotron emission diagnostic

    Taylor, G.

    1990-01-01

    The Tokamak Fusion Test Reactor (TFTR) Michelson interferometer has a spectral coverage of 75--540 GHz, allowing measurement of the first four electron cyclotron harmonics. Until recently the instrument has been configured to view the TFTR plasma on the horizontal midplane, primarily in order to measure the electron temperature profile. Electron cyclotron emission (ECE) extraordinary mode spectra from TFTR Supershot plasmas exhibit a pronounced, spectrally narrow feature below the second harmonic. A similar feature is seen with the ECE radiometer diagnostic below the electron cyclotron fundamental frequency in the ordinary mode. Analysis of the ECE spectra indicates the possibility of a non-Maxwellian 40--80 keV tail on the electron distribution in or near the core. During 1990 three vertical views with silicon carbide viewing targets will be installed to provide a direct measurement of the electron energy distribution at major radii of 2.54, 2.78, and 3.09 m with an energy resolution of approximately 20% at 100 keV. To provide the maximum flexibility, the optical components for the vertical views will be remotely controlled to allow the Michelson interferometer to be reconfigured to either the midplane horizontal view or one of the three vertical views between plasma shots

  2. Caoxite-hydroxyapatite composition as consolidating material for the chalk stone from Basarabi-Murfatlar churches ensemble

    Ion, Rodica-Mariana; Turcanu-Caruţiu, Daniela; Fierăscu, Radu-Claudiu; Fierăscu, Irina; Bunghez, Ioana-Raluca; Ion, Mihaela-Lucia; Teodorescu, Sofia; Vasilievici, Gabriel; Rădiţoiu, Valentin

    2015-12-01

    The development of new composition for surface conservation of some architectural monuments represents now an important research topic. The Basarabi-Murfatlar Ensemble, recognized as the first religious monument from mediaeval Dobrogea (Romania) (from 9th to 11th century), is one of the most impressive archaeological sites of Europe. This ensemble is built from amorphous calcium carbonate, very sensitive to humidity, frost, salts, etc. The aim of this paper is to test on chalk stone samples a new consolidant - hydroxyapatite (HAp) mixed with calcium oxalate trihydrate (caoxite) (COT). Some specific techniques for evaluation its impact on chalk stone surface are used, as follows: petrographical and physical-chemical techniques: SEM, OM, ICP-AES, TGA, FTIR and Raman spectroscopy, chromatic parameters changes, the accelerated weathering tests: heating, freeze-thaw, and their effects on porosity and capillary water uptake by the chalk surface. All these have been evaluated before and after treatment with COT-HAp, putting into evidence the effect of the new composition on the chalk stone surface. HAp induces COT stabilization, and their joint composition can bind weathered stone blocks providing a substantial reinforcement of chalk surface.

  3. Diagnostic system for the nuclear medicine with baby cyclotron

    Kashihara, Masao; Wakasa, Shyuichiro

    1982-01-01

    The system of cyclotron nuclear medicine consists of ''RI-production by using the cyclotron'', ''production of radio-pharmaceuticals labeled with RI'', ''positron tomography''. On the other hand, Ultra compact cyclotron (Baby cyclotron) itself, RI production technique and positron tomography have been rapidly developed and advanced. We think that these three functions must be balance in the development in order to spread this system into the routine work in the hospital. However, since the technology of the synthesis for the labeled compounds is not so developed so far, more advance can be strongly expected. In this report, construction of the cyclotron nuclear medicine, utility for the practical use of RI produced by using the cyclotron, technique of RI production, and the studies on automated and efficient productions of radio-pharmaceuticals labeled with short-lived positron emitters for medical diagnostic use are described. (author)

  4. arXiv Cyclotrons: Magnetic Design and Beam Dynamics

    Zaremba, Simon

    Classical, isochronous, and synchro-cyclotrons are introduced. Transverse and longitudinal beam dynamics in these accelerators are covered. The problem of vertical focusing and iscochronism in compact isochronous cyclotrons is treated in some detail. Different methods for isochronization of the cyclotron magnetic field are discussed. The limits of the classical cyclotron are explained. Typical features of the synchro-cyclotron, such as the beam capture problem, stable phase motion, and the extraction problem are discussed. The main design goals for beam injection are explained and special problems related to a central region with an internal ion source are considered. The principle of a Penning ion gauge source is addressed. The issue of vertical focusing in the cyclotron centre is briefly discussed. Several examples of numerical simulations are given. Different methods of (axial) injection are briefly outlined. Different solutions for beam extraction are described. These include the internal target, extracti...

  5. Calculation of proton beam initial orbit at cyclotron central region

    Pramudita Anggraita

    2012-01-01

    A calculation of proton beam initial orbits at cyclotron central region was carried out using Scilab 5.2.0. The calculation was done in 2 dimensions in a homogeneous magnetic field of 1.66 tesla at frequency of fourth harmonics. The positions of ion source, dees, and dummy dees follow those of GE Minitrace cyclotron, peak dee voltage 30 kV. The calculation yields result comparable to those simulated at KIRAMS-13 cyclotron. (author)

  6. Suppression of cyclotron instability in Electron Cyclotron Resonance ion sources by two-frequency heating

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

    2015-01-01

    Multiple frequency heating is one of the most effective techniques to improve the performance of Electron Cyclotron Resonance (ECR) ion sources. The method increases the beam current and average charge state of the extracted ions and enhances the temporal stability of the ion beams. It is demonstrated in this paper that the stabilizing effect of two-frequency heating is connected with the suppression of electron cyclotron instability. Experimental data show that the interaction between the secondary microwave radiation and the hot electron component of ECR ion source plasmas plays a crucial role in mitigation of the instabilities

  7. Proceedings of eighth joint workshop on electron cyclotron emission and electron cyclotron resonance heating. Vol. 1

    1993-03-01

    The theory of electron cyclotron resonance phenomena is highly developed. The main theoretical tools are well established, generally accepted and able to give a satisfactory description of the main results obtained in electron cyclotron emission, absorption and current drive experiments. In this workshop some advanced theoretical and numerical tools have been presented (e.g., 3-D Fokker-Planck codes, treatment of the r.f. beam as a whole, description of non-linear and finite-beam effects) together with the proposal for new scenarios for ECE and ECA measurements (e.g., for diagnosing suprathermal populations and their radial transport). (orig.)

  8. Proceedings of eighth joint workshop on electron cyclotron emission and electron cyclotron resonance heating. Vol. 2

    1993-03-01

    The theory of electron cyclotron resonance phenomena is highly developed. The main theoretical tools are well established, generally accepted and able to give a satisfactory description of the main results obtained in electron cyclotron emission, absorption and current drive experiments. In this workshop some advanced theoretical and numerical tools have been presented (e.g., 3-D Fokker-Planck codes, treatment of the r.f. beam as a whole, description of non-linear and finite-beam effects) together with the proposal for new scenarios for ECE and ECA measurements (e.g., for diagnosing suprathermal populations and their radial transport). (orig.)

  9. Full-waveform inversion of cross-hole GPR data collected in a strongly heterogeneous chalk reservoir analogue with sharp permittivity and conductivity contrasts

    Keskinen, Johanna; Zibar, Majken Caroline Looms; Moreau, Julien

    2014-01-01

    Chalk sediments form an important reservoir for groundwater onshore and for hydrocarbons in the Danish sector of the North Sea. Cross-hole Ground-penetrating radar (GPR) tomography is an efficient method to investigate subtle porosity variations in the chalk. Traditional ray-based inversion...

  10. COMPARISON OF THE TRADITIONAL CHALK AND BOARD LECTURE SYSTEM VERSUS POWER POINT PRESENTATION AS A TEACHING TECHNIQUE FOR TEACHING GROSS ANATOMY TO THE FIRST PROFESSIONAL MEDICAL STUDENTS

    Nusrat; Abdul

    2015-01-01

    Traditionally and conventionally, gross anatomy is taught by lectures and cadaveric dissection and the lectures are taken with chalk and board (C&B) or chalk and talk method in, India. But there is always a debate over the most effective method of lecture delivery. AIM : The aim of this study was to compare the role and effecti...

  11. Cyclotron will not survive yet this year without state support

    Marcan, P.

    2005-01-01

    In this paper the project of the Cyclotron Center of the Slovak republic is described. On the basis of this project the state joint-stock company Biont was constituted. Small cyclotron is in operation; big cyclotron is in process of manufacture and it will be put in operation in 2007. Small cyclotron will be used for production of radiopharmaceuticals. Positron emission tomograph (PET) in Oncological Institute of St. Elizabeth (in Bratislava) and gamma camera in Central Military Hospital (in Ruzomberok) are constituents of the Biont. The PET will be also in Biont. The hadron therapy of ophthalmic tumors is planned. Financial plans of the Biont up to 2009 are presented

  12. The problems of high efficient extraction from the isochronous cyclotron

    Schwabe, J.

    1994-06-01

    The problem of high efficient extraction (η ≥ 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 applied in the production of medical radioisotopes, labeled pharmaceuticals as well as in neutron therapy (oncology), machine industry, agriculture (plant mutagenesis), etc. The aim of the proposed topic is to solve this problem on the AIC-144 isochronous cyclotron in the INP (Institute of Nuclear Physics). Lately, a beam of 20 MeV deuterons with an efficiency of ca. 15% was extracted from this cyclotron. (author). 25 refs, 14 figs

  13. Cyclotron based nuclear science. Progress report, April 1, 1985-March 31, 1986

    Youngblood, D.H.

    1986-08-01

    Progress report for cyclotron based nuclear science cyclotron facility are summarized. Research is described under the headings heavy ion reactions, nuclear theory, atomic studies and activation analysis, superconducting cyclotron and instrumentation. Publications are listed

  14. High resolution microgravity investigations for the detection and characterisation of subsidence associated with abandoned, coal, chalk and salt mines

    Styles, P.; Toon, S.; Branston, M.; England, R. [Keele Univ., Applied And Environmental Geophysics Group, School of Physical and Geographical Sciences (United Kingdom); Thomas, E.; Mcgrath, R. [Geotechnology, Neath (United Kingdom)

    2005-07-01

    The closure and decay of industrial activity involving mining has scarred the landscape of urban areas and geo-hazards posed by subsurface cavities are ubiquitous throughout Europe. Features of concern consist of natural solution cavities (e.g. swallow holes and sinkholes in limestone gypsum and chalk) and man-made cavities (mine workings, shafts) in a great variety of post mining environments, including coal, salt, gypsum, anhydrite, tin and chalk. These problems restrict land utilisation, hinder regeneration, pose a threat to life, seriously damage property and services and blight property values. This paper outlines the application of microgravity techniques to characterise abandoned mining hazard in case studies from Coal, Chalk and Salt Mining environments in the UK. (authors)

  15. High resolution microgravity investigations for the detection and characterisation of subsidence associated with abandoned, coal, chalk and salt mines

    Styles, P.; Toon, S.; Branston, M.; England, R.; Thomas, E.; Mcgrath, R.

    2005-01-01

    The closure and decay of industrial activity involving mining has scarred the landscape of urban areas and geo-hazards posed by subsurface cavities are ubiquitous throughout Europe. Features of concern consist of natural solution cavities (e.g. swallow holes and sinkholes in limestone gypsum and chalk) and man-made cavities (mine workings, shafts) in a great variety of post mining environments, including coal, salt, gypsum, anhydrite, tin and chalk. These problems restrict land utilisation, hinder regeneration, pose a threat to life, seriously damage property and services and blight property values. This paper outlines the application of microgravity techniques to characterise abandoned mining hazard in case studies from Coal, Chalk and Salt Mining environments in the UK. (authors)

  16. Understanding Fluid Flow during Tectonic Reactivation: An Example from the Flamborough Head Chalk Outcrop (UK

    O. Faÿ-Gomord

    2018-01-01

    Full Text Available Flamborough Head chalks are located at the extremities of E-W and N-S trending fault systems along the Yorkshire coast (UK. Rock deformation is expressed in Selwicks Bay where a normal fault is exposed along with a high density of calcite veins. The fault mineralization is tested using geochemistry. Crosscutting relationships are used to differentiate between three vein generations: a network of parallel veins that are oriented perpendicular to stratigraphy (Group I, hydraulic breccia with typical jigsaw puzzle structure (Group II, and a third generation of calcite veins crosscutting the two previous generations (Group III. Geochemical analyses revealed that all three generations possess the same chemical signature and must reflect successive pulses from the same mineralizing fluid source. Strontium isotope analyses showed that the veins have elevated 87Sr/86Sr ratios, that is, up to 7.110, while ratios of the chalk matrix equal 7.707. The latter value is in agreement with the signature of Late Cretaceous seawater. Consequently, the source of the fluid is external, reflecting an open system. The radiogenic Sr-isotope ratios, combined with low iron concentration, suggest that fluids migrated through sandy deposits. Fluid inclusion salinities range from 0 to 12 eq. wt% NaCl equiv. with a dominance of very low salinity inclusions, reflecting a meteoric signal. This leads to a model where meteoric fluids stored in an underlying confined sandstone aquifer were remobilized. The wide range of salinities could result from mixing of the meteoric fluid with some more saline fluids present in the rock sequence or from the dissolution of salts in the subsurface. In addition to the understanding of the local paragenetic evolution of the veining in Flamborough Head chalks, this study offers an insight into the way how fluid flows and mineralizes along fault zones.

  17. Tracking selenium in the Chalk aquifer of northern France: Sr isotope constraints

    Cary, L.; Benabderraziq, H.; Elkhattabi, J.; Gourcy, L.; Parmentier, M.; Picot, J.; Khaska, M.; Laurent, A.; Négrel, Ph.

    2014-01-01

    Highlights: • We report the chemistry of the Chalk groundwater affected by Se contamination. • Strontium isotopes were used to identify the groundwater bodies and their mixings. • The spatial and temporal Se variability is mainly linked to the presence of Se-rich clays. • Saturation or desaturation of Se-rich clays control Se mobility. - Abstract: Groundwater at the southern and eastern edges of France’s Paris Basin has a selenium content that at times exceeds the European Framework Directive’s drinking-water limit value of 10 μg/L. To better understand the dynamics of the Chalk groundwater being tapped to supply the city of Lille and the Se origins, we used a combination of geochemical and isotopic tools. Strontium isotopes, coupled with Ca/Sr, Mg/Sr and Se/Sr ratios, were used to identify the main groundwater bodies and their mixings, with the Mg/Sr and Se/Sr ratios constraining a ternary system. Groundwater in the agricultural aquifer-recharge zone represents a first end-member and displays the youngest water ages of the catchment along with the highest Sr isotopic signature (0.70842) and low Se contents. Anaerobic groundwater constitutes a second major end-member affected by water-rock interactions over a long residence time, with the lowest Sr isotopic signature (0.70789) and the lowest Se content, its low SF6 content confirming the contribution of old water. Se-rich groundwater containing up to 30 μg/L of Se represents a third major end-member, with an intermediate Sr isotopic ratio (0.70826), and is mainly constrained by the clayey Se-rich formation overlying the Chalk aquifer. The spatial and temporal Se variability in the groundwater is clearly linked to the presence of this formation identified as Tertiary and also to the hydrological conditions; saturation of the Se-rich clays by oxygenated groundwater enhances Se mobility and also Sr adsorption onto the clays. This multi-tool study including Sr isotopes successfully identified the Se

  18. Nuclear magnetic resonance and sound velocity measurements of chalk saturated with magnesium rich brine

    Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    2013-01-01

    The use of low field Nuclear Magnetic Resonance (NMR) to determine petrophysical properties of reservoirs has proved to be a good technique. Together with sonic and electrical resistivity measurements, NMR can contribute to illustrate the changes on chalk elasticity due to different pore water...... solutions of the same ionic strength. Saturation with a solution that contained divalent ions caused a major shift on the distribution of the relaxation time. The changes were probably due to precipitats forming extra internal surface in the sample. Sonic velocities were relatively low in the MgCl2 solution...

  19. Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge

    Hansen, H.K.; Christensen, Iben Vernegren; Ottosen, Lisbeth M.

    2003-01-01

    . Casagrande's coefficients were determined for the four materials at different water contents. The experiments in this work showed that chalk could be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM by electroosmosis....... The process was not optimised indicating that higher dry matter contents could be achieved by electroosmosis. It was possible to relate Casagrande's coefficient directly to the electroosmotic coefficient obtained by dewatering experiments....

  20. Optimization of Spore Forming Bacteria Flooding for Enhanced Oil Recovery in North Sea Chalk Reservoir

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Eliasson Lantz, Anna

    2015-01-01

    .2-3.8 cm) during bacteria injection. Further seawater flooding after three days shut in period showed that permeability gradually increased in the first two sections of the core and started to decrease in the third section of the core (3.8-6.3 cm). Complete plugging was never observed in our experiments.......Little has been done to study microbial enhanced oil recovery (MEOR) in chalk reservoirs. The present study focused on core flooding experiments to see microbial plugging and its effect on oil recovery. A pressure tapped core holder with pressure ports at 1.2 cm, 3.8 cm, and 6.3 cm from the inlet...

  1. Investigation of Lecturer's Chalk by x-ray Florescence and Fast Neutron Activation Techniques

    Hassan, M.F.

    2011-01-01

    Different samples of lecturer's chalk were studied, using X-ray florescence (XRF) and Fast Neutron Activation Analysis (FNAA) techniques to ensure the safety of its use. The K (X-rays) and the gamma-rays were measured, using Si(Li) and high-purity germanium (HPGe) spectrometers to detect and determine qualitatively and quantitatively the constituents of the studied samples. The concentrations of the elements (Ca and small traces of Al, Fe, Mg and Si) were measured and their presence was confirmed by gamma-ray, lifetime and/or XRF measurements.

  2. Uranium-phosphate relationship in phosphated chalks of the Mons and Picardie Bassins

    Quinif, Y; Charlet, J M; Dupuis, C; Robaszynski, F [Faculte Polytechnique de Mons (Belgium)

    1981-11-30

    The lithological and geochemical conditions relative to the ''Senonian'' phosphatic chalks are relatively simple in the Basins of Mons (Belgium) and of Picardy (France). Their characteristics permit us to study chiefly the uranium-phosphate relation. It appears a very good linear correlation between the phosphate and the uranium. The coefficient U/P/sub 2/O/sub 5/ remains a constant from the bottom to the top of the same section, but changes in space for synchronic formations (lateral variation of geochemical facies) and in time for two separated basins.

  3. Upper Cretaceous chalk facies and depositional history recorded in the Mona-1 core, Mona Ridge

    Anderskouv, Kresten; Surlyk, Finn

    2011-01-01

    , including mudflow, debris flow, and slumping. Pelagic deposits vary mainly in terms of the concentration of siliciclastic material, the trace-fossil assemblage, and the presence or ab­sence of primary sedimentary structures. Pelagic sedimentation was probably punctuated by the deposition of thin turbidites...... slump packages (14–18 in total) are interpreted, forming over 40% of the succession; debrites appear to be the most common precursor facies involved in slumping. The vertical succession of facies records an earliest Cenomanian facies shift from dominantly siliciclastic to chalk deposition...

  4. Quick, Easy, and Economic Mineralogical Studies of Flooded Chalk for EOR Experiments Using Raman Spectroscopy

    Laura Borromeo

    2018-05-01

    Full Text Available Understanding the chalk-fluid interactions and the associated mineralogical and mechanical alterations on a sub-micron scale are major goals in Enhanced Oil Recovery. Mechanical strength, porosity, and permeability of chalk are linked to mineral dissolution that occurs during brine injections, and affect the reservoir potential. This paper presents a novel “single grain” methodology to recognize the varieties of carbonates in rocks and loose sediments: Raman spectroscopy is a non-destructive, quick, and user-friendly technique representing a powerful tool to identify minerals down to 1 µm. An innovative working technique for oil exploration is proposed, as the mineralogy of micron-sized crystals grown in two flooded chalk samples (Liége, Belgium was successfully investigated by Raman spectroscopy. The drilled chalk cores were flooded with MgCl2 for ca. 1.5 (Long Term Test and 3 years (Ultra Long Term Test under North Sea reservoir conditions (Long Term Test: 130 °C, 1 PV/day, 9.3 MPa effective stress; Ultra Long Term Test: 130 °C, varying between 1–3 PV/day, 10.4 MPa effective stress. Raman spectroscopy was able to identify the presence of recrystallized magnesite along the core of the Long Term Test up to 4 cm from the injection surface, down to the crystal size of 1–2 µm. In the Ultra Long Term Test core, the growth of MgCO3 affected nearly the entire core (7 cm. In both samples, no dolomite or high-magnesium calcite secondary growth could be detected when analysing 557 and 90 Raman spectra on the Long and Ultra Long Term Test, respectively. This study can offer Raman spectroscopy as a breakthrough tool in petroleum exploration of unconventional reservoirs, due to its quickness, spatial resolution, and non-destructive acquisition of data. These characteristics would encourage its use coupled with electron microscopes and energy dispersive systems or even electron microprobe studies.

  5. Mechanical and chemical processes affecting the chalk during burial, insights from combined reflection seismics, well data and field work

    Moreau, Julien; Boussaha, Myriam; Thibault, Nicolas Rudolph

    2014-01-01

    and cores analyses, respectively.However, few sites allow to combine all the different scale of observation for chalk diagenesis. Onshore and offshore high resolution seismics, two fully cored >350 m wells with wireline logging tools and very high quality exposures from a coastal cliff and a quarry form...... works have been performed with astronomical calibration based on stable isotope stratigraphy, wireline logs as well as several palaeontological proxies and detailed sedimentological analysis. Since a couple of decades, a specific kind of fractures has been described in the Chalk of Denmark, the so...

  6. Environmental isotope studies related to groundwater flow and saline encroachment in the chalk aquifer of Lincolnshire, England

    Lloyd, J.W.; Howard, K.W.F.

    1978-01-01

    The isotopes of tritium and carbon are used to study part of the North Lincolnshire Chalk aquifer in England. The tritium data support the view that the aquifer is a thin fissure system and indicate that some changes in flow direction have occurred due to recent abstraction. The data are also consistent with other chemical data in elucidating groundwater entering the Chalk from deeper aquifers. Carbon isotopes are used to distinguish between saline water bodies and suggest that saline water was entrapped within the aquifer in the Eemian and Flandrian stages of the Pleistocene. (orig.) [de

  7. Benchmarking of codes for electron cyclotron heating and electron cyclotron current drive under ITER conditions

    Prater, R.; Farina, D.; Gribov, Y.; Harvey, R. W.; Ram, A. K.; Lin-Liu, Y. R.; Poli, E.; Smirnov, A. P.; Volpe, F.; Westerhof, E.; Zvonkovo, A.

    2008-01-01

    Optimal design and use of electron cyclotron heating requires that accurate and relatively quick computer codes be available for prediction of wave coupling, propagation, damping and current drive at realistic levels of EC power. To this end, a number of codes have been developed in laboratories

  8. Method of enhancing cyclotron beam intensity

    Hudson, Ed D.; Mallory, Merrit L.

    1977-01-01

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

  9. New compact cyclotron design for SPIRAL

    Duval, M.; Bourgarel, M.P.; Ripouteau, F.

    1995-01-01

    The SPIRAL project whose purpose is the production and the acceleration of radioactive nuclei is under realization at GANIL. The new facility uses a cyclotron as post accelerator taking place behind the present machine. The magnet structure is made of 4 independent return yokes and a common circular pole piece (3.5 m in diameter) with 4 sectors. The average induction needed is 1.56 Tesla with hill and valley gaps of respectively 0.12 and 0.3 m. The required field patterns are adjusted by means of circular trim coils located between the sectors and the pole piece. (author)

  10. Isotope separation by ionic cyclotron resonance

    Compant La Fontaine, A.; Gil, C.; Louvet, P.

    1986-10-01

    The principle of the process of isotopic separation by ionic cyclotron resonance is explained succinctly. The theoretical calculation of the isotopic effect is given as functions of the electric and magnetic fields in the frame of single particle approximation and of plasma collective theory. Then, the main parts of the demonstration device which is in operation at the CEA, are described here: the supraconducting magnetic field, the used diagnostics, the principle of the source and the collecting apparatus. Some experimental results are given for chromium. The application of the process to ponderal separation of metal isotopes, as chromium, nickel and molybdenum is discussed in view of production of medical, structural and irradiation isotopes

  11. Diffusion induced by cyclotron resonance heating

    Riyopoulos, S.; Tajima, T.; Hatori, T.; Pfirsch, D.

    1985-09-01

    The wave induced particle transport during the ion cyclotron resonance heating is studied in collisionless toroidal plasmas. It is shown that the previously neglected non-conservation of the toroidal angular momentum IP/sub phi/ caused by the toroidal wave component E/sub phi/ is necessary to allow particle diffusion and yields the leading diffusive contribution. While the induced ion transport for the rf power in contemporary experiments is of the order of the neoclassical value, that of fast alpha particles is quite large if resonance is present

  12. RELATIVISTIC CYCLOTRON INSTABILITY IN ANISOTROPIC PLASMAS

    López, Rodrigo A.; Moya, Pablo S.; Muñoz, Víctor; Valdivia, J. Alejandro [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Navarro, Roberto E.; Araneda, Jaime A. [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Viñas, Adolfo F., E-mail: rlopez186@gmail.com [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, MD 20771 (United States)

    2016-11-20

    A sufficiently large temperature anisotropy can sometimes drive various types of electromagnetic plasma micro-instabilities, which can play an important role in the dynamics of relativistic pair plasmas in space, astrophysics, and laboratory environments. Here, we provide a detailed description of the cyclotron instability of parallel propagating electromagnetic waves in relativistic pair plasmas on the basis of a relativistic anisotropic distribution function. Using plasma kinetic theory and particle-in-cell simulations, we study the influence of the relativistic temperature and the temperature anisotropy on the collective and noncollective modes of these plasmas. Growth rates and dispersion curves from the linear theory show a good agreement with simulations results.

  13. Cyclotron resonance in a cathode ray tube

    Gherbanovschi, N.; Tanasa, M.; Stoican, O.

    2002-01-01

    Absorption of the RF energy by the electron beam in a cathode ray tube due to the cyclotron resonance is described. The cathode ray tube is placed within a Helmholtz coils system supplied by a sawtooth current generator. In order to generate RF field and to detect RF absorption a gate dip-meter equipped with a FET transistor is used. The bias voltage variations of the FET transistors as a function of the magnetic field are recorded. The operating point of the cathode ray tube has been chosen so that the relaxation oscillations of the detection system can be observed. (authors)

  14. Properties of the TRIUMF cyclotron beam

    Craddock, M.K.; Blackmore, E.W.; Dutto, G.; Kost, C.J.; Mackenzie, G.H.; Richardson, J.R.; Root, L.W.; Schmor, P.

    1975-08-01

    Eight percent of the 300 keV d.c. beam from the ion source can be transmitted to 500 MeV in the TRIUMF cyclotron, without using the buncher. The beam losses are entirely accounted for; there are no significant losses due to orbit dynamic problems during 1500 turns of acceleration. The phase history is in good agreement with predictions based on the magnetic field survey. The effect of the harmonic coils and injection parameters on beam quality has been investigated. (author)

  15. High efficiency cyclotron trap assisted positron moderator

    Gerchow, L.; Cooke, D. A.; Braccini, S.; Döbeli, M.; Kirch, K.; Köster, U.; Müller, A.; Van Der Meulen, N. P.; Vermeulen, C.; Rubbia, A.; Crivelli, P.

    2017-01-01

    We report the realisation of a cyclotron trap assisted positron tungsten moderator for the conversion of positrons with a broad keV- few MeV energy spectrum to a mono-energetic eV beam with an efficiency of 1.8(2)% defined as the ratio of the slow positrons divided by the $\\beta^+$ activity of the radioactive source. This is an improvement of almost two orders of magnitude compared to the state of the art of tungsten moderators. The simulation validated with this measurement suggests that usi...

  16. Axial injection in Orsay superconducting cyclotron

    Depauw, J.; Kugler, M.F.; Legoff, A.; Potier, J.C.; Richomme, A.; Skowron, R.; Mandrillon, P.; Schapira, J.P.

    1983-01-01

    The compact superconducting cyclotron currently planned at IPN at Orsay is designed for light ion acceleration together with heavy ion acceleration. From the beginning, for this reason, a central geometry able to receive an inflector (to 90deg C) allowing the axial injection of low energy ion beams given by an outer source. The present study is aimed at showing the technical feasibility of theoretical results obtained on axial injection. First experimental study has been made of spatial repartition in three dimensions of electric potential developed by a central geometry of 3 electrodes. Then, the electric study of an electrostatic mirror has been made [fr

  17. Cyclotrons at the Institute of Physical and Chemical Research

    Imamura, Masashi.

    1989-01-01

    In this article the destruction by American forces, during World War II, of the Japanese cyclotrons and the subsequent construction of new cyclotrons at the Institute of Physical and Chemical Research, Japan is described. Their use for biological and medical radiation chemistry studies is summarized. (UK)

  18. Lower-hybrid absorption at the ion cyclotron harmonics

    Puri, S.

    1975-01-01

    In the presence of magnetic field gradients, the lower-hybrid wave can be absorbed through linear collisionless damping at the location of cyclotron or cyclotron harmonic resonances acting as singular turning points in the path of the advancing wave-front. (Auth.)

  19. A radioisotope production cyclotron designed to minimize dose

    Szlavik, F.F.; Moritz, L.E.

    1992-01-01

    This paper describes a radioisotope production cyclotron which has been designed to minimize the dose to personnel during operation and maintenance. The design incorporates lessons learned from the operation of a CP42 cyclotron and has resulted in a reduction of the dose by a factor of more than 10. (author)

  20. Calculation of particle dynamics in CI-10 cyclotron

    Samsonov, E.V.; Karamysheva, G.A.; Vorozhtsov, S.B.

    1999-01-01

    The calculations of beam dynamic characteristics of High-Intensity Cyclotron-Injector CI-10 for deuteron beam of 15 MeV energy are presented. Analytical estimations of space charge effects are given. In order to increase the intensity of the accelerator beam some ideas about the cyclotron design modification are given too. (author)

  1. First results of beam generation test for JAERI AVF cyclotron

    Tachikawa, T.; Hayashi, Y.; Ishii, K.

    1992-01-01

    The performance of JAERI AVF cyclotron was investigated with several kinds of ions in the wide energy range. The 90 MeV protons of 10 μA intensity was successfully extracted for the first time by the model 930 cyclotron. The feature of beam chopping system is also presented. (author)

  2. Resonance cones below the ion cyclotron frequency: theory and experiment

    Bellan, P.

    1976-03-01

    The resonance cones existing below the ion cyclotron frequency, ω/sub c/sub i//, are shown, theoretically and experimentally, to be the asymptotes of hyperbolic constant-phase surfaces of low-frequency ion acoustic waves. Above ω/sub c/sub i// the surfaces transform into ellipses that are related to the electrostatic ion cyclotron waves and ion acoustic waves

  3. Computer modeling of magnetic structure for IC-35 cyclotron

    Alenitskij, Yu.G.; Morozov, N.A.

    1998-01-01

    An extensive series of calculations has been carried out in order to design the magnetic structure of the IC-35 cyclotron for radioisotope production. The calculations were carried out by 2-D POISCR code. The average magnetic field and its variation were produced with the help of two different calculation models. The parameters of the cyclotron magnetic system are presented

  4. Fabrication of beam diagnostic components for Superconducting Cyclotron at Kolkata

    Roy, S.; Bhattacharya, S.; Das, T.; Bhattacharyya, T.K.; Pal, S.; Pal, G.; Mallik, C.; Bhandari, R.K.

    2009-01-01

    The viewer probe and main probe are used for determining the position and current of charged particles as it is accelerated inside the superconducting cyclotron. The viewer probe is used to visually observe the shape of the charged particle beam inside the cyclotron with the help of a borescope. The main probe measures the distribution of charged particles. The viewer probe and main probe are bellow sealed. They can be positioned with an accuracy of 0.5 mm at different radii within the superconducting cyclotron. M9 slit is placed after the exit flange of the cyclotron. It determines the position of the beam leaving the cyclotron. The beam line has slits, faraday cup, beam viewers, collimators, etc. for beam diagnostics. This paper presents the mechanical design and details of beam diagnostic components. (author)

  5. New superconducting cyclotron driven scanning proton therapy systems

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

    2005-01-01

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

  6. Operation of the Karlsruhe Isochronous Cyclotron in 1975

    Schulz, F.; Schweickert, H.

    1976-06-01

    The operation of the Karlsruhe Isochronous Cyclotron in 1975 is briefly surveyed. The main reasons for a very short period for maintenance, repair and installation, and several additional efforts to improve the reliability of the accelerator installation, are discussed. The status and the results of several technical developments for the cyclotron are described: 1) the axial injection system; 2) computer aided cyclotron operation; 3) ion source development; 4) capacitive current measurement at the external beam; 5) new correction coils for the cyclotron; 6) improvement of the neutron time-of-flight spectrometer. As there is an increasing interest in using this type of accelerator for research in fields other than nuclear physics, it was felt appropriate to present short surveys on investigations at our cyclotron in 1975 in the fields of: 1) solid state physics; 2) engineering; 3) materials research; 4) nuclear medicine; 5) nuclear chemistry. (orig.) [de

  7. A new generation of medical cyclotrons for the 90's

    Milton, B.F.

    1995-08-01

    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

  8. A new generation of medical cyclotrons for the 90's

    Milton, B.F.

    1995-08-01

    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 we 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. We 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. (author)

  9. U-2g0 cyclotron operational experience and improvement

    Gigal, B.N.; Gul'bekyan, G.G.; Kozlov, S.I.; Oganesyan, R.Ts.

    1983-01-01

    Brief description of main syste's of the U-200 isochronous 2-m cyclotron put into opera ion in 1968 is given and its operational characteristics a e presented. The cyclotron is used for conducting inve tigations in the field of nuclear physics. Ions from d uterium to argon have been accelerated in the cyclotro'. Annual time of target irradiation constitutes 2000-4000. The specific features of the cyclotron are: high l vel of a magnetic field (of about 20 kOe), possibili y of acceleration of ions with different mass-to-charge ratio a low correcting winding power, simple and high-e fective beam extraction by the method of charge exchange on a thin target allowing to vary smoothly energy of extracted ons. An experience in the U-200 cyclotron development and o eration is used as the basis for designing and choosing basic parameters of the U-200P, U-250, U-400 heavy ion cyclotrons

  10. How burial diagenesis of chalk sediments controls sonic velocity and porosity

    Fabricius, Ida Lykke

    2003-01-01

    Based on P-wave velocity and density data, a new elastic model for chalk sediments is established. The model allows the construction of a series of isoframe (IF) curves, each representing a constant part of the mineral phase contributing to the solid frame. The IF curves can be related to the pro......Based on P-wave velocity and density data, a new elastic model for chalk sediments is established. The model allows the construction of a series of isoframe (IF) curves, each representing a constant part of the mineral phase contributing to the solid frame. The IF curves can be related.......1 or higher. Upon burial, the sediments lose porosity by mechanical compaction, and concurrently, the calcite particles recrystallize into progressively more equant shapes. High compaction rates may keep the particles in relative motion, whereas low compaction rates allow the formation of contact cement...... this process testifies to the absence of chemical compaction by calcite-calcite pressure dissolution, as well as to the porosity-preserving effect of contact cementation. At sufficient burial stress, the presence of stylolites indicates that pressure dissolution takes place between calcite., and silicates...

  11. Status report on RIKEN Ring Cyclotron

    Yano, Y.

    1988-01-01

    This paper gives a status report on RIKEN Ring Cyclotron (RRC), successfully commissioned on December 16, 1986. The routine operation of RRC began in April, 1987, and was made until March 1988. April and May were devoted to the machine studies, and beams were delivered to the experiments from the end of May. Seven kinds of ion species from carbon to copper were used for the nuclear physics and atomic physics experiments during these one-year runs. High quality beams with transverse emittances less than 10 mm mrad, energy spread of approximately 0.1% and pulse width less than 300 psec were extracted. Since the middle of March, 1988, RRC has been shut down for extending the beam transfer lines and installing the various experimental setups. Next experimental program will start in July, 1988. The initial operational status of RRC is described as well as the running construction program of the new injector, a K70 AVF cyclotron with an external ECR ion source

  12. Electron cyclotron heating calculations for ATF

    Goldfinger, R.C.; Batchelor, D.B.

    1986-03-01

    The RAYS geometrical optics code has been used to calculate electron cyclotron wave propagation and heating in the Advanced Toroidal Facility (ATF) device under construction at Oak Ridge National Laboratory (ORNL). The intent of this work is to predict the outcome of various heating scenarios and to give guidance in designing an optimum heating system. Particular attention is paid to the effects of wave polarization and antenna location. We investigate first and second harmonic cyclotron heating with the parameters predicted for steady-state ATF operation. We also simulate the effect of wall reflections by calculating a uniform, isotropic flux of power radiating from the wall. These results, combined with the first-pass calculations, give a qualitative picture of the heat deposition profiles. From these results we identify the compromises that represent the optimum heating strategies for the ATF model considered here. Our basic conclusions are that second harmonic heating with the extraordinary mode (X-mode) gives the best result, with fundamental ordinary mode (O-mode) heating being slightly less efficient. Assuming the antenna location is restricted to the low magnetic field side, the antenna should be placed at phi = 0 0 (the toroidal angle where the helical coils are at the sides) for fundamental heating and at phi = 15 0 (where the helical coils are at the top and bottom) for second harmonic heating. These recommendations come directly from the ray tracing results as well as from a theoretical identification of the relevant factors affecting the heating

  13. Acceleration of tritons with a compact cyclotron

    Wegmann, H.; Huenges, E.; Muthig, H.; Moringa, H.

    1981-01-01

    With the compact cyclotron at the Faculty of Physics of the Technical University of Munich, tritons have been accelerated to an energy of 7 MeV. A safe and reliable operation of the gas supply for the ion source was obtained by a new tritium storage system. A quantity of 1500 Ci tritium is stored by two special Zr-Al getter pumps in a non-gaseous phase. The tritium can be released in well-defined amounts by heating the getter material. During triton acceleration the pressure in the cyclotron vacuum chamber is maintained only by a large titanium sputter-ion pump, thus forming a closed vacuum system without any exhaust of tritium contaminated gas. Any tritium contaminations in the air can be detected by an extremely sensitive tritium monitoring system. The triton beam with a maximum intensity of 30 μA has been used so far to produce neutron-rich radioisotopes such as 28 Mg, 43 K, or 72 Zn, which are successfully applied in tracer techniques in the studies of biological systems. (orig.)

  14. Cyclotron Resonances in Electron Cloud Dynamics

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

    2009-01-01

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

  15. Visual assistance system for cyclotron operation

    Okamura, Tetsuya; Tachikawa, Toshiki; Murakami, Tohru.

    1994-01-01

    A computer-based operation system for a cyclotron which assists operators has been developed. It is the operation assistance system depending on visual sense to indicate beam parameters to operators. First, the mental model of operators at the time of beam adjustment was analyzed, and it was presumed to be composed of five partial mental models, that is, beam behavior model, feasible setting region model, parameter sensitivity model, parameter interrelation model and status map model. Next, three visual interfaces were developed. Beam trajectory is rapidly calculated and graphically displayed whenever operators change parameters. Feasible setting regions (FSR) for parameters that satisfy the beam acceptance criteria of a cyclotron are indicated. The distribution of beam current values which are the quantity for evaluating adjustment is indicated as search history. Finally, for evaluating the system effectiveness, the search time required to reach the optimum conditions was measured. In addition, the system usability was evaluated by written questionnaires. The result of experiment showed the reduction of search time by about 65%. The written questionnaires survey showed the operators highly evaluate system usability. (K.I.)

  16. An integrated modelling and multicriteria analysis approach to managing nitrate diffuse pollution: 2. A case study for a chalk catchment in England.

    Koo, B K; O'Connell, P E

    2006-04-01

    The site-specific land use optimisation methodology, suggested by the authors in the first part of this two-part paper, has been applied to the River Kennet catchment at Marlborough, Wiltshire, UK, for a case study. The Marlborough catchment (143 km(2)) is an agriculture-dominated rural area over a deep chalk aquifer that is vulnerable to nitrate pollution from agricultural diffuse sources. For evaluation purposes, the catchment was discretised into a network of 1 kmx1 km grid cells. For each of the arable-land grid cells, seven land use alternatives (four arable-land alternatives and three grassland alternatives) were evaluated for their environmental and economic potential. For environmental evaluation, nitrate leaching rates of land use alternatives were estimated using SHETRAN simulations and groundwater pollution potential was evaluated using the DRASTIC index. For economic evaluation, economic gross margins were estimated using a simple agronomic model based on nitrogen response functions and agricultural land classification grades. In order to see whether the site-specific optimisation is efficient at the catchment scale, land use optimisation was carried out for four optimisation schemes (i.e. using four sets of criterion weights). Consequently, four land use scenarios were generated and the site-specifically optimised land use scenario was evaluated as the best compromise solution between long term nitrate pollution and agronomy at the catchment scale.

  17. Cyclotron Production of Technetium-99m

    Gagnon, Katherine M.

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

  18. TASCC newsletter volume 7 no. 6

    Thomson, L.

    1993-06-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this June issue of TASCC is a facility report, updates on experiments being conducted, educational affiliation with the Deep River Science Academy and findings involving gadolinium-149 and information on a highly deformed band found in praseodymium. 2 figs

  19. TASCC newsletter volume 8 no. 5

    Thomson, L.

    1994-05-01

    A newsletter produced by Chalk River's Tandem Accelerator Superconducting Cyclotron Facility. Included in this May issue of TASCC is an update of the facility, a visit by the Nuclear Physics Technical Review Committee, sizing of meteors, Deep River Science Academy on TASCC projects and a listing of May's experiments. 2 figs

  20. TASCC newsletter volume 7 no. 11

    Thomson, L

    1993-11-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this November issue of TASCC is an update of the facility, news of a purchase of phase-shifters and a listing of experiments run in November. 2 figs.

  1. TASCC newsletter volume 7 no. 12

    Thomson, L

    1993-12-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this December issue of TASCC is an update of the facility, a year end review by the director and a listing of experiments carried out in December. 3 figs.

  2. TASCC newsletter volume 7 no. 10

    Thomson, L

    1993-10-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this October issue of TASCC is an update of the facility report, ECR ion source development, new measurement of Carbon 10, Penning-trap mass spectrometer and a listing of October`s experiments. 2 figs.

  3. TASCC newsletter volume 8 no. 4

    Thomson, L

    1994-04-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this April issue of TASCC is an update of the facility, news on the Penning-trap spectrometer, educators at CRL, AECB inspection and a listing of April`s experiments. 1 fig.

  4. TASCC newsletter volume 7 no. 4

    Thomson, L

    1993-04-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in the April issue is information on damage tests of satellite instrumentation, general news on success of beams achieved, assessment by NPPAP panel on TASCC programs, staff changes and a listing of April`s experiments. 2 figs.

  5. TASCC newsletter volume 8 no. 6

    Thomson, L

    1994-06-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this June issue of TASCC is an update of the facility, a review of federal strategy for science and technology, construction on the Canadian Penning Trap Mass Spectrometer and a listing of June`s experiments. 1 fig.

  6. TASCC newsletter volume 8 no. 8

    Thomson, L

    1994-08-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this August issue of TASCC is an update of the facility, personnel changes at TASCC, awards to TASCC personnel, workshop on deflectors, beam calculations on PC`s and a listing of August`s experiments. 2 figs.

  7. TASCC newsletter volume 8 no. 7

    Thomson, L

    1994-07-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this July issue of TASCC is an update of the facility,news on TASCC personnel, results of a coulomb-excitation and a listing of July`s experiments. 4 figs.

  8. TASCC newsletter volume 9 no. 4

    Thomson, L

    1995-04-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this April issue of TASCC is an update of the facility, analysis of Chernobyl samples, staff changes, Internet availability and a listing of April`s experiments. 1 fig.

  9. TASCC newsletter volume 9 no. 6

    Thomson, L

    1995-06-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this June issue of TASCC is an update of the facility, TASCC workshop on international success and a listing of Junes`s experiments. 1 fig.

  10. TASCC newsletter volume 9 no. 12

    Thomson, L

    1995-12-01

    A newsletter produced by Chalk River`s Tandem Accelerator Superconducting Cyclotron Facility. Included in this December issued of TASCC is an update of the facility, a year -end review of TASCC by the director and a listing of December`s experiments. 1 fig.

  11. Life-history strategies as a tool to identify conservation constraints: A case-study on ants in chalk grasslands

    Noordwijk, C.G.E.; Boer, P.; Mabelis, A.A.; Verberk, W.C.E.P.; Siepel, H.

    2012-01-01

    Species’ life-history traits underlie species–environment relationships. Therefore, analysis of species traits, combined into life-history strategies, can be used to identify key factors shaping the local species composition. This is demonstrated in a case-study on ants in chalk grasslands. We

  12. Tilting oil-water contact in the chalk of Tyra Field as interpreted from capillary pressure data

    Fabricius, Ida Lykke; Rana, M.A.

    2010-01-01

    The Tyra Field in the central North Sea is located in Palaeogene and Upper Cretaceous chalk. It contains a natural gas zone underlain by an oil leg. Based on analysis of logs and core data from ten wells drilled prior to the field being put into production, normalized water saturation depth-trend...... inequilibriumin the aquifer following tectonic tilting....

  13. Towards an improved lithostratigraphic subdivision of the chalk group in the Netherlands North Sea area - A seismic stratigraphic approach

    Molen, A.S. van der; Wong, Th.E.

    2007-01-01

    In the Netherlands North Sea area, the Chalk Group has thus far been subdivided into the Cenomanian Texel Formation, the Turonian to Maastrichtian Ommelanden Formation and the Danian Ekofisk Formation. This paper describes the attempt to arrive at a more detailed lithostratigraphic subdivision for

  14. Towards an improved lithostratigraphic subdivision of the Chalk Group in the Netherlands North Sea area – A seismic stratigraphic approach

    Molen, A.S. van der; Wong, Th.E.

    In the Netherlands North Sea area, the Chalk Group has thus far been subdivided into the Cenomanian Texel Formation, the Turonian to MaastrichtianOmmelanden Formation and the Danian Ekofisk Formation. This paper describes the attempt to arrive at a more detailed lithostratigraphicsubdivision for

  15. Deep saltwater in Chalk of North-West Europe: origin, interface characteristics and development over geological time

    Bonnesen, Ellen Prip; Larsen, F.; Sonnenborg, T.O.

    2009-01-01

    High-concentration saltwaters occur in many places in the regional Chalk aquifers of North-West Europe; to investigate deep occurrences, profiles of interstitial porewater chemistry have been studied from three 250-450m deep cores drilled in the eastern parts of Zealand, Denmark. At the studied...

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

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

    1992-01-01

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

  17. Compact superconducting cyclotron C400 for hadron therapy

    Jongen, Y.; Abs, M.; Blondin, A.; Kleeven, W.; Zaremba, S.; Vandeplassche, D. [IBA, Chemin du Cyclotron 3, B-1348 Louvain-la-Neuve (Belgium); Aleksandrov, V.; Gursky, S.; Karamyshev, O. [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation); Karamysheva, G., E-mail: gkaram@nu.jinr.r [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation); Kazarinov, N.; Kostromin, S.; Morozov, N.; Samsonov, E.; Shirkov, G.; Shevtsov, V.; Syresin, E.; Tuzikov, A. [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation)

    2010-12-01

    The compact superconducting isochronous cyclotron C400 has been designed by the IBA-JINR collaboration. It will be the first cyclotron in the world capable of delivering protons, carbon and helium ions for cancer treatment. The cyclotron construction is started this year within the framework of the Archade project (Caen, France). {sup 12}C{sup 6+} and {sup 4}He{sup 2+} ions will be accelerated to 400 MeV/uu energy and extracted by the electrostatic deflector, H{sub 2}{sup +} ions will be accelerated to the energy of 265 MeV/uu and extracted by stripping. The magnet yoke has a diameter of 6.6 m, the total weight of the magnet is about 700 t. The designed magnetic field corresponds to 4.5 T in the hills and 2.45 T in the valleys. Superconducting coils will be enclosed in a cryostat; all other parts of the cyclotron will be warm. Three external ion sources will be mounted on the switching magnet on the injection line located below the cyclotron. The main parameters of the cyclotron, its design, the current status of the development work on the cyclotron systems are presented.

  18. Cyclotron Development and Technical Aspects on Accelerator Based Laboratory Development

    Sunarhadijoso

    2000-01-01

    BATAN is planning to establish an accelerator-based laboratory at P3TM Yogyakarta as an effort in the development and use of accelerator technology for improving industrial performance and public welfare. This paper reviews several aspects of cyclotron technology and describes the combination of a linear accelerator - cyclotron system as an alternative to be considered in the planing of the laboratory. The progress of cyclotron technology is discussed covering three generations, i.e. conventional cyclotron, synchrocyclotron and AVF cyclotron generations. The planning should not consider the accelerator application for radioisotope production because it is established in Serpong with the existing negative ion cyclotron. The proposed facility at P3TM may comprise two linear accelerators coupled with a positive ion cyclotron of synchrocyclotron generation. In fact, the attachment of the synchrocyclotron unit is flexible and it can be installed subsequently if the higher energy particle beam, which can not be produced by the linear accelerators, is extremely needed. Some technical aspects related to ion beam application, building construction and infrastructure, human resources, and specification of function test are discussed for additional information in the implementation of the planning. (author)

  19. Survey on radionuclide producing using cyclotron method in Malaysia

    Mohd Fadli Mohammad Noh

    2008-01-01

    This research discuss about basic design and systems of medical cyclotron that Malaysia currently have, its applications in radionuclide production and upcoming technologies of cyclotron. Surveys have been carried out on cyclotron facilities at Hospital Putrajaya and Wijaya International Medical Center, WIMC as well as reactor facility at Malaysia Nuclear Agency. The sources in this research also involves on-line and library searches. Information obtained are recorded, categorized, synthesized and discussed. systems of cyclotron of Hospital Putrajaya are further discussed in details. Based from the surveys carried out, it is found out that cyclotron facilities both in Hospital Putrajaya and WIMC only produce ( 18 F)FDG with radioactivity of 18 F produced in 2007 are 16479 mCi and 92546 mCi respectively. Survey also revealed that radioisotope production at Nuclear Malaysia has had its operation been ceased. A new radiopharmaceutical, namely CHOL is suggested to be synthesized by both facilities as a new PET tracer. Latest developments concerning technologies of cyclotron as well as other accelerators such as laser for future medical accelerator, prospect of boron neutron capture and the potential of hadron therapy in Malaysia are discussed here. Radioisotope production in Malaysia is expected to keep booming in future due to increase in usage of PET techniques and the construction of more compact, easy to handle and less costly cyclotrons. (author)

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

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

    1992-01-01

    Pc 2 electromagnetic ion cyclotron waves at 0.1 waves at 0.1 Hz, near the oxygen cyclotron frequency, have been observed by ISEE 1 and 2 between L = 7.6 and 5.8 on an inbound near-equatorial pass in the dusk sector. The waves occurred in a thick plasmapause of width ∼ 1.5 R E and penetrated ∼1 R E into the plasmasphere. Wave onset was accompanied by significant increases in the thermal (0-100 eV) He + and the warm (0.1-16 keV/e) O + and He + heavy ion populations. The most intense waves (8 nT) were observed in the outer plasmasphere where convection drift velocities (E x B)/B 2 were largest and the Alfven velocity was a minimum. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by cold plasma propagation theory are identified in the wave data. Poynting fluxes calculated during the first 15 min of the event show wave energy propagation directions both parallel and antiparallel to the field. Computations of the experimental wave spectra during the passage through the plasmapause show that the spectral slots relate to local plasma parameters, possibly suggesting an ion cyclotron wave growth source near the spacecraft. A regular wave packet structure seen over the first 30 min of the event may be attributed to the modulation of this energy source by the Pc 5 waves seen at the same time. Overall, the results are considered an example of an electromagnetic ion cyclotron wave-particle interaction occurring during the outer plasmasphere refilling process at the time of the substorm recovery phase

  1. Present status of device controls and hardware interfaces for the RCNP ring cyclotron

    Yamazaki, T.; Tamura, K.; Hosono, K.

    1994-01-01

    Since the first proton beam from the injector AVF cyclotron was injected to the ring cyclotron in 1991, the computer control system has been used for the beam acceleration of the ring cyclotron. Some device control modules have been updated, and computer configuration has been changed in 1992. Total control system performs basic facilities almost satisfactory under actual cyclotron operation. (author)

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

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

    2011-12-01

    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.

  3. Estimation of groundwater recharge to chalk and sandstone aquifers using simple soil models

    Ragab, R.; Finch, J.; Harding, R.

    1997-03-01

    On the assumption that the water draining below the root zone is potentially available for groundwater recharge, two current UK methods for estimating annual groundwater recharge have been compared with a new soil model using data from four sites under permanent grass in the UK: two sites representative of the Chalk aquifer at Bridgest Farm (Hampshire) and Fleam Dyke (Cambridgeshire), and two sites on the Triassic sandstone at Bicton College (Devon) and Bacon Hall (Shropshire). A Four Root Layers Model (FRLM), the Penman-Grindley model and the UK Meteorological Office Rainfall and Evaporation Calculation System (MORECS) were used. The new soil model was run with potential evaporation as input both from the MORECS and from the Penman-Monteith equation. The models were run for the Chalk sites both with and without a bypass flow of 15% of rainfall. Bypass was not considered for the sandstone sites. The performance of the models was tested against neutron probes measurements of soil moisture deficits. In addition, the annual groundwater recharge estimated from the models was compared with the published values obtained from the 'zero flux plane' method. Generally, the Penman-Grindley model was more successful in predicting the time for soil to return to its field capacity than in predicting the magnitude of the soil moisture deficit. The annual groundwater recharge was predicted with reasonable accuracy. The MORECS relatively tended to overestimate the soil moisture deficits and to delay the time at which the soil returns to its field capacity. The consequences were underestimates of annual groundwater recharge, owing either to the higher values of potential evaporation calculated from the MORECS or tothe high available water capacity values associated with the soils under consideration. The new soil model (FRLM) predicts the soil moisture deficits successfully and hence is reliable in estimating the annual groundwater recharge. The model is capable of doing this with

  4. Analytic descriptions of ion cyclotron absorption

    Bers, A.; Francis, G.; Fuchs, V.; Lashmore-Davies, C.N.; Ram, A.K.

    1987-05-01

    Analysis of energy propagation and absorption in ion-cyclotron heating of tokamak plasmas has relied on numerical solutions of fourth (and sixth) order differential equations for slab models of the plasma (poloidal) cross section. Realistic two-dimensional and fully toroidal geometry analyses would become quite unwieldy. It is shown here that the analysis of the slab model can be simplified considerably. A first-order differential equation is shown to describe the transmission coefficient for the fast wave, and it is solved analytically. A second order differential equation is shown to adequately describe both transmission and reflection. Conditions for ion absorption or mode conversion are derived. Including toroidal effects in propagation, conditions for electron absorption on the mode-converted ion-Bernstein waves are also described analytically

  5. Ion cyclotron emission by spontaneous emission

    Da Costa, O [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Gresillon, D [Ecole Polytechnique, 91 - Palaiseau (France). Lab. de Physique des Milieux Ionises

    1994-07-01

    The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs.

  6. In-house cyclotron and nuclear medicine

    Tateno, Yukio; Shishido, Fumio; Yamazaki, Toshiro

    1982-01-01

    In-house cyclotron produced radioisotopes and positron computed tomography provide a unique technique which gives cross-sectional bodyimages of various kinds of physiological activities of living human body. Applications of the technique to clinical study might throw a new light on the etiologically unknown disorders of human central nervous system and etc. However, some difficulties should be settled before the establishment of this technique as an useful research and diagnostic tool. One of them was spatial resolution of positron computed tomography, and another was selection and development of really effective labeled compounds for the disease in question. A rotary positron emission computed tomography device was developed by our physicist team, and our chemist team developed various kinds of radiopharmaceuticals. Clinical applications of the technique started in our institute in November 1979, using the positron computed tomography machine named Positrologica I and the pharmaceuticals, 13sup( n h3, )11sup( C o and )18 F-2-fluoro-deoxy-glucose. (author)

  7. Electron cyclotron resonance heating and current drive

    Fidone, I.; Castejon, F.

    1992-07-01

    A brief summary of the theory and experiments on electron- cyclotron heating and current drive is presented. The general relativistic formulation of wave propagation and linear absorption is considered in some detail. The O-mode and the X-mode for normal and oblique propagation are investigated and illustrated by several examples. The experimental verification of the theory in T-10 and D- III-D is briefly discussed. Quasilinear evolution of the momentum distribution and related applications as, for instance, non linear wave, damping and current drive, are also considered for special cases of wave frequencies, polarization and propagation. In the concluding section we present the general formulation of the wave damping and current drive in the absence of electron trapping for arbitrary values of the wave frequency. (Author) 13 refs.

  8. Electron cyclotron resonance (ECR) ion sources

    Jongen, Y.

    1984-05-01

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

  9. Particle acceleration by electromagnetic ion cyclotron turbulence

    Crew, G.B.; Chang, Tom

    1990-01-01

    The LF EM-turbulence which furnishes energy for the acceleration of ions in various regions of the earth's magnetosphere efficiently accomplishes its transfer of energy from waves to particles through ion cyclotron resonance (ICR) with the left-hand polarized component of the turbulence; the result of this interaction is a heating of the particle distribution. A general theoretical treatment of ICR heating in a weakly inhomogeneous magnetic geometry is presented, en route to a more detailed examination of auroral ion conics' formation. A substantial simplification of the analysis of the altitude-asymptotic form of the conic distribution is obtained via the similarity transformation introduced into the properties of the electric field spectral density and the earth's dipolar magnetic field. 60 refs

  10. Ion cyclotron emission by spontaneous emission

    Da Costa, O.; Gresillon, D.

    1994-01-01

    The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs

  11. Ion cyclotron heating in TMX-U

    Dimonte, G.; Barter, J.; Romesser, T.; Molvik, A.W.; Cummins, W.F.; Falabella, S.; Poulsen, P.

    1987-01-01

    Ion cyclotron heating (ICH) is applied to TMX-U to improve the thermal barrier performance by reducing the passing ion collisionality. During its development, measurements of the antenna loading resistance, R p , and the absorption efficiency, η, were compared with calculations with the antenna design code ANTENA over a wide range of densities and frequencies. Good agreement in R p was obtained in the short wavelength slow wave regime but not for long wavelength fast waves because the experimental magnetic field gradients are not modelled in ANTENA. Similarly, η is much larger experimentally (40%) than in ANTENA (10%) due to the magnetic beach in TMX-U. In its application, ICH successfully decreased the passing ion collisionality tenfold but did not extend thermal barrier plugging to higher density, indicating that collisional barrier filling is not currently limiting TMX-U performance. (author). 23 refs, 23 figs

  12. Neutron radiography using a transportable superconducting cyclotron

    Allen, D.A. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Hawkesworth, M.R. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Beynon, T.D. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Green, S. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Rogers, J.D. (Rolls-Royce, Derby (United Kingdom)); Allen, M.J. (Rolls-Royce, Derby (United Kingdom)); Plummer, H.C. (Rolls-Royce, MatEval, Derby (United Kingdom)); Boulding, N.J. (Oxford Instruments (United Kingdom)); Cox, M. (Oxford Instruments (United Kingdom)); McDougall, I. (Oxford Instruments (United Kingdom))

    1994-12-30

    A thermal neutron radiography system based on a compact 12 MeV superconducting proton cyclotron is described. Neutrons are generated using a thick beryllium target and moderated in high density polyethylene. Monte Carlo computer simulations have been used to model the neutron and photon transport in order to optimise the performance of the system. With proton beam currents in excess of 100 [mu]A, it can provide high thermal neutron fluxes with L/D ratios of between 50 and 300 for various applications. Both film and electronic imaging are used to produce radiographs. The electronic imaging system consists of a [sup 6]Li-loaded ZnS intensifier screen, and a low light CCD or SIT camera. High resolution images can be recorded and computer-controlled data processing, analysis and display are possible. ((orig.))

  13. Electron - cyclotron resonance heating and current drive

    Fidone, I.; Castejon, F.

    1992-01-01

    A brief summary of the theory and experiments on electron- cyclotron heating and current drive is presented. The general relativistic formulation of wave propagation and linear absorption is considered in some detail. The O-mode and the X-mode for normal and oblique propagation are investigated and illustrated by several examples. The experimental verification of the theory in T-10 and D- III-D is briefly discussed. Quasilinear evolution of the momentum distribution and related applications as, for instance, non linear wave, damping and current drive, are also considered for special cases of wave frequencies, polarization and propagation. In the concluding section we present the general formulation of the wave damping and current drive in the absence of electron trapping for arbitrary values of the wave frequency. (Author) 13 refs

  14. Electron Cyclotron Resonances in Electron Cloud Dynamics

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

    2008-01-01

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

  15. Auxiliary accelerating system for TRIUMF cyclotron

    Zach, M.; Fong, K.; Laxdal, R.; Mackenzie, G.H.; Pacak, V.; Pearson, J.; Richardson, J.R.; Stanford, G.; Worsham, R.

    1990-06-01

    A 92 MHz auxiliary accelerating cavity has been designed and manufactured for installation in the TRIUMF cyclotron. Operating at the fourth harmonic of the RF with a peak voltage of 150 kV, it almost doubles the present energy gain per turn in the 400-500 MeV range, and reduces by ∼50% the stripping loss of the H - beam. This significant improvement will allow a substantial increase in the extracted current above the present routine level of 150μA while maintaining the same levels of residual radioactivity. The system is completed and being commissioned. A description of the design and commissioning procedures is presented, and results of beam tests given. (Author) 7 refs., 5 figs

  16. Isochronization calculations for the Indiana University cyclotron

    Jones, W.P.

    1975-01-01

    A series of calculations using measured magnetic fields was performed to determine the optimal gradient coil currents for the wide range of operating conditions to be experienced by the Indiana University main stage cyclotron. Depending on the particle type to be accelerated and final energy desired, the required radial field increase varies from 0.5 percent to 22 percent. An iterative least squares fitting technique is used to minimize orbit time variations. For the acceleration of 200 MeV protons (330 revolutions, fourth harmonic), the maximum phase excursion is predicted to be less than two rf degrees. The technique used can be adapted to using measured phase histories to predict corrections to gradient coil currents. (auth)

  17. Magnetic field optimisation and orbit calculation for VEC superconducting cyclotron

    Debnath, J.; Dey, M.K.; Mallik, C.; Bhandari, R.K.

    2003-01-01

    At VECC, Kolkata preparations are underway to measure the magnetic field of the cyclotron. Also once the superconducting cyclotron is assembled prediction of beam related parameters will be a very important exercise to carry out. Considering this the beam behaviour in the cyclotron will be crucial to achieve these goals. The present paper deals with the efforts in this direction and using a test beam of He 1+ 20 MeV/n the trim coil currents, the tune variation and the (r,Pr) behaviour of the central trajectory

  18. Design features and operating characteristics of the MC-50 cyclotron

    Bak, Hae Ill; Bak, Joo Shik

    1989-01-01

    The MC-50 cyclotron at Korean Cancer Center Hospital is now operational for neutron therapy and medical radioisotope production. Design features, mechanical structures and operating characteristics of the MC-50 are described in this paper. Optimum operating condition for this cyclotron has been determined by the repetitive running, and the performances of the internal beam have been investigated through the measurements of intensity and spatial distribution of the internal beam as a function of the radius of the cyclotron. Routinely, the 40 μA of 50 MeV protons have been obtained at first Faraday cup with a extraction efficiency of 61%. (Author)

  19. Health physics aspects of the 1.5M cyclotron

    Song, W.J.; Du, H.L.; Wei, Z.Q.; Xia, X.S.; Zheng, H.Z.; Jiang, G.F.; Liu, Y.Y.

    1987-01-01

    The 1.5m cyclotron in Institute of Modern Physics, Academia Sinica had operated for about 20 years until 1984 then converted to 1.7m sector focusing cyclotron. In this period it mainly used for fast neutron physics, light ion induced nucleus reactions, radioisotope production and heavy ion reactions. The health physics performed on this cyclotron including personnel dose monitoring, area monitoring (radiation field, radioactive aerosol, surface contamination and activated components etc.), maintenance inspection, environment survey and waste disposal is presented in this paper

  20. Thermal Stabilization of Cryogenic System in Superconducting Cyclotron

    Shin, Seung Jae; Kim, Kyung Min; Cho, Hyung Hee; Hong, Bong Hwan; Kang, Joon Sun; Ahn, Dong Hyun

    2011-01-01

    Radiology has some useful applications for medical purpose. For cancer therapy, the superconducting cyclotron should generate heavy ion beams. It radiates heavy ion beams to cancer patients. In order to make cyclotron system stable, the cryogenic system which makes superconducting state should work constantly. However, radiation heat transfer of cryogenic system should be considered because liquid helium's boiling point is extremely low and there is huge temperature difference between the cryogenic system and ambient temperature. Accordingly, thermal analysis should be carried out. In this paper, the numerical analysis of the cryogenic system in practical superconducting cyclotron show temperature distribution and suggest the number of coolers using ANSYS Workbench program

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

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

    1993-11-01

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

  2. An experimental study on cyclotron-Cherenkov radiation

    Lee, C Y; Masuzaki, M; Yoshida, H; Toyosugi, N; Kamada, K; Ando, R [Kanazawa Univ. (Japan). Department of Physics

    1997-12-31

    Dielectric-loaded cylindrical waveguide configurations with an injected electron beam in which the growth rate of the cyclotron-Cherenkov instability surpasses that of the Cherenkov instability were sought by numerical treatment, and one configuration of this kind was found. This configuration consists of a metallic core and an outer metallic cylinder with a dielectric liner on the inner surface. Based on the calculations, an experimental device was designed and assembled to investigate experimentally radiation due to the cyclotron-Cherenkov instability. Beam propagation in the dielectric-loaded coaxial waveguide and microwave radiation due to the cyclotron-Cherenkov instability and the Cherenkov instability were studied. (author). 6 figs., 10 refs.

  3. Ion extraction in the cyclotron geometry

    Rodenburg, R.E.

    1985-01-01

    The detailed physics of ion beam extraction from a plasma column by intense sinusoidal radio frequency (rf) electric fields at the ion cyclotron frequency omega/sub ci/ and its harmonics is experimentally studied. Results describe the instantaneous relationship - within one rf period of approx. = 3009 nsec - between applied rf, the plasma response and the ions expelled by rf and plasma fields. Reflex discharges in H 2 , D 2 , and He with ion and electron densities greater than or equal to10 11 cm -3 are subjected to 0-5 kV zero-to-peak rf electric fields E vector and 0.65-9.00 kG background magnetic fields B 0 vector with E vector perpendicular to B 0 vector. Ion currents up to 200 μA are extracted. Nonperturbing optical diagnostics measure the relative amplitude and phase of instantaneous ion and electron density fluctuations induced by the rf during each rf cycle and the time variation of extracted ion bursts, the latter made possible by the use of a phosphor beam-stop. Detailed dependences on external electric and magnetic fields are reported. The plasma density fluctuations are in good agreement with the dispersion relation for electrostatic ion cyclotron waves (EICW), and the beam data show current enhancement at the second harmonic over that at the fundamental and evidence for a radically different mechanism for the rf-driven ion extraction process than conventional wisdom assumes. This work represents the first detailed, systematic study of the ac ion extraction process

  4. Diagenesis of silica-rich mounded chalk, the Coniacian Arnager Limestone, Denmark

    Buus Madsen, Heine; Stemmerik, Lars; Surlyk, Finn

    2010-01-01

    The Coniacian Arnager Limestone Formation is exposed on the Danish island of Bornholm in the Baltic Sea. It is composed of mound-bedded siliceous chalk, and X-ray diffraction and scanning electron microscopy indicate a content of 30-70% insoluble minerals, including authigenic opal-CT, quartz......, clinoptilolite, feldspars, calcite, dolomite, and barite. Opal-CT and clinoptilolite are the most common and constitute 16-53% and 2-9%, respectively. The content of insoluble minerals varies laterally bothwithinthemounds and inplanar beds, and the opal-CT content varies by up to 10% vertically. Themounds...... precipitation of opal-CT. The opal-CT formed at temperatures around 17°C, the precipitation lowered the silica activity and the Si/Al ratio of the pore water, resulting in precipitation of clinoptilolite, feldspar and smectite. Calcite formed synchronouslywith the latest clinoptilolite.Minoramounts of quartz...

  5. Controls on upper Campanian-Maastrichtian chalk deposition in the eastern Danish Basin

    Boussaha, Myriam; Thibault, Nicolas Rudolph; Anderskouv, Kresten

    2017-01-01

    % of the sediment. Sedimentation took place in deep water, below the photic zone and storm-wave base, and is characterized by decimetre to metre-scale variations in facies and trace fossil assemblages indicating repeated shifts in depositional environment. Integration of facies with published data on sea...... of accumulation rates and sea temperatures and is interpreted to represent a very broad set of deep water environmental conditions with an ample supply of calcareous nannofossil debris and intense bioturbation. Longer term shifts in deposition are best expressed by distribution of clay, flint and bioturbated...... micro-wackestone, bioturbated wackestone and laminated mudstone chalk facies, whereas the trace fossil assemblages appear less useful. The data set indicates overall shallowing over time with two distinctive events of clay influx to the basin during the late Campanian-earliest Maastrichtian and late...

  6. Determination of naturally radioactive elements in chalk sticks by means of gamma spectroscopy

    Abd El-Wahab, Magda; Morsy, Zeinab; El-Faramawy, Nabil

    2010-04-01

    The radiation hazards due to ingestion of chalkboard dust were investigated. Sixteen samples from three different origin fabricates were used. The estimation of radiation hazard indices were based on the evaluation of the concentration activities of the natural radionuclides 238U, 232Th and 40K. The radium equivalent activity, external hazard index, internal hazard index and the annual dose equivalent associated with the radionuclides were calculated and compared with international recommended values to assess the radiation hazard. The values of internal and external radiation hazard indices were found to be less than unity. The annual effective dose rate obtained, E eff, and the annual gonadal dose equivalent (AGDE) are found to be less than the limit of the doses recommended by the International Commission on Radiological Protection for the general public. The analytical results show that besides the main calcium content, some toxic elements, S, Mo and Pb and Ni and Pb, in the Egyptian and imported chalk stocks, respectively, existed.

  7. Change in Biot's effective stress coefficient of chalk during pore collapse

    Alam, M. Monzurul; Fabricius, Ida Lykke

    2013-01-01

    the grains could also change during elastic deformation of the grains in a rock mechanics test. Diagenetic change in grain contact cement of chalk can be compared with stress-induced change in the laboratory. The change in porosity is studied with reference to the change in effective stress on grain contacts...... and porosity reduces at a slower rate. We noticed that presence of non carbonates and hydrocarbon could increase σ'm. During rock mechanics test in the lab, with increased applied stress, σ'm increases, Biot's effective stress coefficient shows a decreasing trend, while a minor porosity reduction was observed......Biot's effective stress coefficient (α) is a measure of how well grains in the rocks are connected with each other. The amount of contact cements between the grains determines the stiffness of rocks. Change in grain contact occurs during natural diagenesis of sedimentary rock. Contact between...

  8. Full-waveform Inversion of Crosshole GPR Data Collected in Strongly Heterogeneous Chalk

    Keskinen, Johanna; Zibar, Majken Caroline Looms; Nielsen, Lars

    2015-01-01

    Chalk is an important reservoir rock for hydrocarbons and for groundwater resources for many major cities. Therefore, this rock type has been extensively investigated using both geological and geophysical methods. Many applications of crosshole GPR tomography rely on the ray approximation...... and corresponding inversions of first break traveltimes and/or maximum first-cycle amplitudes. Due to the inherent limitations associated with such approaches, the resulting models tend to be overly smooth and cannot adequately capture the small-scale heterogeneities. In contrast, the full-waveform inversion uses...... address the importance of (i) adequate starting models, both in terms of the dielectric permittivity and the electrical conductivity, (ii) the estimation of the source wavelet, (iii) and the effects of data sampling density when imaging this rock type. Moreover, we discuss the resolution of the bedding...

  9. Stochastic modelling of porosity using seismic impedances on a volume of chalk in the Dan Field

    Vejbaek, O.V.

    1995-12-31

    Seismic impedances calculated from logs show very good correlation to log porosities in wells penetrating the chalk reservoir in the Dan Field, Danish North Sea. This is the basis for an attempt to use seismic impedances derived from inversion as soft data for geostatistical reservoir characterization. The study focusses on porosity description of the Maastrichtian chalk reservoir unit, laterally restricted to an area covered by a subset of a 3D seismic survey. This seismic volume was inverted using the ISIS software producing a volume of seismic impedances. Spatial porosity realizations are produced using a gaussian collocated co-simulation algorithm, where well log porosities constitute the hard data input and seismic impedances are the soft data input. The simulated volume measures 1400 m x 1525 m x 102 m and is oriented parallel to lines and cross lines in the seismic dataset. Simulated blocks measures 25 m x 25 m x 6 m equivalent to twice the line and trace spacing, and approximately equivalent to the seismic sample rate. The correlation coefficient between log porosities and impedances calculated from logs alone are shown to be misleading since they suggest unrealistic high coefficients. However, the actual data used, namely inversion derived impedances and log porosities, still show correlation coefficients in the order of -0,45, which is quite sufficient to make the inversion results very useful. It is remarkable that the calculated correlation coefficient is based on 15 wells, and the inversion is based on only one well. The negative correlation coefficient indicate that high impedances correspond to low porosities and vice-versa. The impedance data indicate the level of average porosities at locations between wells. The fine structure is produced by the geostatistic process, with averages constrained by seismic impedances. The seismic impedances derived from the inversion process are thus shown to constitute useful primary data to constrain reservoir

  10. Combining Chalk Talk with PowerPoint to Increase In-class Student Engagement

    Swati Betharia

    2016-11-01

    Full Text Available In striving to attain a higher degree of in-class student engagement, and target a larger number of preferred student-learning styles, this case study describes a multimodal teaching approach. PowerPoint slides have gradually gained popularity over the more traditional chalk and talk lecture design. The student population in today’s age seeks more non-passive modes of information delivery. Numerous novel approaches to enhance active learning, such as flipped classroom and problem-based learning, have recently been explored. While working well for therapeutic and lab-based courses, these formats may not be best-suited for all basic science topics. The importance of basic science in a pharmacy curriculum is well emphasized in the 2016 ACPE Standards. To actively involve students in a pharmacology lecture on diuretics, a session was designed to combine the PowerPoint and chalk talk approaches. Students created 10 concept diagrams following an instructor, who explained each step in the process using a document camera. For visual learners, these diagrams provided a layered representation of the information, gradually increasing in complexity. For learners with a preference for the reading learning style, the information was also available in corresponding PowerPoint slides. Scores from pre- and post-session quizzes indicated a high level of concept understanding and recall (median 1 [IQR 0 – 2] vs 4 [IQR 3 – 5]; p<0.001. The student perception survey data reported higher in-class attention levels (76%, an appreciation for the utility of self-created concept diagrams (88%, and a call for additional sessions being presented in this format (73%. Targeting a variety of student learning styles by using the active development of concept diagrams, in addition to traditional PowerPoint slides, can promote student engagement and enhance content understanding.   Type: Case Study

  11. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 23

    1967-10-09

    Progress is reported in the design, installation of various components of the cyclotron, including coils, magnets, rf system, and vacuum system. Also reported are measurements on magnets and rf components. (LEW)

  12. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 20

    1967-06-30

    Progress is reported in the fabrication and testing of cyclotron components, including magnet system and rf system components. Work on vacuum components and instrumentation and control equipment is also reported. (LEW)

  13. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 32

    1968-06-28

    Completion of magnet tests, followed by completion of installation of major cyclotron components, are reported. Intermediate level power tests of the rf system are also reported. Design and fabrication of the control system are reported to be under way. (LEW)

  14. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 26

    1968-01-17

    Progress is reported in the fabrication, installation, and testing of cyclotron components, including magnets and coils, rf components, vacuum and control equipment. Also reported are magnet and rf component measurements. (LEW)

  15. Cyclotron radiation by a multi-group method

    Chu, T.C.

    1980-01-01

    A multi-energy group technique is developed to study conditions under which cyclotron radiation emission can shift a Maxwellian electron distribution into a non-Maxwellian; and if the electron distribution is non-Maxwellian, to study the rate of cyclotron radiation emission as compared to that emitted by a Maxwellian having the same mean electron density and energy. The assumptions in this study are: the electrons should be in an isotropic medium and the magnetic field should be uniform. The multi-group technique is coupled into a multi-group Fokker-Planck computer code to study electron behavior under the influence of cyclotron radiation emission in a self-consistent fashion. Several non-Maxwellian distributions were simulated to compare their cyclotron emissions with the corresponding energy and number density equivalent Maxwellian distribtions

  16. Cryogenic system for VECC K500 superconducting cyclotron

    Pal, G; Bhattacharyya, T K; Bhandari, R K

    2009-01-01

    VEC Centre, Kolkata in India is at an advanced stage of commissioning a K500 superconducting cyclotron. The superconducting coil of the magnet for cyclotron is cooled by liquid helium. Three liquid helium cooled cryopanels, placed inside the Dees of the radiofrequency system, maintain the vacuum in the acceleration region of the superconducting cyclotron. The cryogenic system for magnet for cyclotron has been tested by cooling the coil and energizing the magnet. The cryogenic system for cryopanels has also been tested. Heater and temperature sensor were placed on the liquid helium cold head for cryopanel. The temperature of the cold head was observed to be below 20 K upto a heat load of 11.7 watt.

  17. H-superconducting cyclotron for PET isotope production

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

    2014-01-01

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

  18. NORTICA—a new code for cyclotron analysis

    Gorelov, D.; Johnson, D.; Marti, F.

    2001-12-01

    The new package NORTICA (Numerical ORbit Tracking In Cyclotrons with Analysis) of computer codes for beam dynamics simulations is under development at NSCL. The package was started as a replacement for the code MONSTER [1] developed in the laboratory in the past. The new codes are capable of beam dynamics simulations in both CCF (Coupled Cyclotron Facility) accelerators, the K500 and K1200 superconducting cyclotrons. The general purpose of this package is assisting in setting and tuning the cyclotrons taking into account the main field and extraction channel imperfections. The computer platform for the package is Alpha Station with UNIX operating system and X-Windows graphic interface. A multiple programming language approach was used in order to combine the reliability of the numerical algorithms developed over the long period of time in the laboratory and the friendliness of modern style user interface. This paper describes the capability and features of the codes in the present state.

  19. Cyclotrons for clinical and biomedical research with PET

    Wolf, A.P.

    1987-01-01

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

  20. Electron cyclotron resonance heating in a short cylindrical plasma ...

    The power mode conversion efficiency is estimated to be ... has also found application in electron cyclotron current drive (ECCD) in fusion ... (few GHz) of microwave sources, a small linear ECR plasma system can also serve ..... References.