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Sample records for proton magnetometer survey

  1. The low cost Proton Precession Magnetometer developed at the Indian Institute of Geomagnetism

    International Nuclear Information System (INIS)

    Mahavarkar, P.; Singh, S.; Labde, S.; Dongre, V.; Patil, A.

    2017-01-01

    Proton magnetometers are the oldest scalar magnetometers. The first commercial units were produced in early 1960s as portable instruments. In continuation airborne instruments appeared with optimized speed of readings and sensitivity, large sensors etc. Later development of Overhauser and optically pumped magnetometers has eliminated Proton magnetometers from airborne surveys. However they remain very popular in various ground surveys and observatories. With this primary purpose of generating the ground based magnetic data, the Indian Institute of Geomagnetism (IIG) for the last 3 decades have been developing low cost Proton Precession Magnetometers (PPM). Beginning with the 1 nT PPM which has undergone several changes in design, the successor PM7 the advanced version has been successfully developed by the institute and is installed at various observatories of the institute. PM7 records the total field 'F' with accuracy of 0.1 nT and a sampling rate of 10 seconds/sample. This article briefly discusses the design and development of this IIG make PM7 and compares the data recorded by this instrument with one of the commercially available Overhauser magnetometer in the world market. The quality of data recorded by PM7 is in excellent agreement with the Overhauser. With the available quality of data generated by this instrument, PM7 is an affordable PPM for scientific institutions, schools and colleges intending to carry out geomagnetic studies. The commercial cost of PM7 is ≈ 20% of the cost of Overhauser available in market.

  2. The low cost Proton Precession Magnetometer developed at the Indian Institute of Geomagnetism

    Science.gov (United States)

    Mahavarkar, P.; Singh, S.; Labde, S.; Dongre, V.; Patil, A.

    2017-05-01

    Proton magnetometers are the oldest scalar magnetometers. The first commercial units were produced in early 1960s as portable instruments. In continuation airborne instruments appeared with optimized speed of readings and sensitivity, large sensors etc. Later development of Overhauser and optically pumped magnetometers has eliminated Proton magnetometers from airborne surveys. However they remain very popular in various ground surveys and observatories. With this primary purpose of generating the ground based magnetic data, the Indian Institute of Geomagnetism (IIG) for the last 3 decades have been developing low cost Proton Precession Magnetometers (PPM). Beginning with the 1 nT PPM which has undergone several changes in design, the successor PM7 the advanced version has been successfully developed by the institute and is installed at various observatories of the institute. PM7 records the total field `F' with accuracy of 0.1 nT and a sampling rate of 10 seconds/sample. This article briefly discusses the design and development of this IIG make PM7 and compares the data recorded by this instrument with one of the commercially available Overhauser magnetometer in the world market. The quality of data recorded by PM7 is in excellent agreement with the Overhauser. With the available quality of data generated by this instrument, PM7 is an affordable PPM for scientific institutions, schools and colleges intending to carry out geomagnetic studies. The commercial cost of PM7 is ≈ 20% of the cost of Overhauser available in market.

  3. A theoretical and experimental investigation of the proton magnetometer

    International Nuclear Information System (INIS)

    Hancke, G.P.

    1987-01-01

    This study comprises the investigation of the properties of the proton magnetometer based on the free precession of protons. The basic principle of the free precession of protons in the earth's magnetic field is described and the most important factors affecting this free precession are examined. It is shown that very important parameters to keep in mind are the polarization time and the magnitude of the polarization field. A discussion of the errors of a proton magnetometer built on the periodometer principles is given and it is shown that the error in counting of the number of precession periods during the time of measurement contributes most to the total error. The magnitude of this error depends on the signal-to-noise ratio, the instability of the operating threshold of the discriminator of the period counter, it's operating time and the tuning accuracy of the sensor to the precession frequency. The penetration to a magnetometer input of variable magnetic and electric interferences, their influence on the phase of the useful signal, and the resulting measurement errors are examined and methods of reducing the effects of interferences are discussed. The optimization of sensor design is very important in the development of proton magnetometers. The coil geometry, physical size, the working substance and the polarization design are important parameters. The selection of a method for processing the precession signal of a proton magnetometer is examined, given a sensor and signal amplifier with fixed parameters. A method is proposed and compared with known methods. Measurement errors are computed for various signal-to-noise ratios and times of observation of the precession signal, and it is shown that the proposed method is superior to conventional methods found in commercial instruments

  4. Scalar magnetometers for space applications

    DEFF Research Database (Denmark)

    Primdahl, Fritz

    A survey of existing instrumentation and developments is presented emphasizing instrumentation for in-flight calibration of vector magnetometers on magnetic mapping missions. Proton free or forced precession magnetometers are at the focus as calibration references, because the proton gyromagnetic...

  5. Autonomous Aeromagnetic Surveys Using a Fluxgate Magnetometer

    Directory of Open Access Journals (Sweden)

    Douglas G. Macharet

    2016-12-01

    Full Text Available Recent advances in the research of autonomous vehicles have showed a vast range of applications, such as exploration, surveillance and environmental monitoring. Considering the mining industry, it is possible to use such vehicles in the prospection of minerals of commercial interest beneath the ground. However, tasks such as geophysical surveys are highly dependent on specific sensors, which mostly are not designed to be used in these new range of autonomous vehicles. In this work, we propose a novel magnetic survey pipeline that aims to increase versatility, speed and robustness by using autonomous rotary-wing Unmanned Aerial Vehicles (UAVs. We also discuss the development of a state-of-the-art three-axis fluxgate, where our goal in this work was to refine and adjust the sensor topology and coupled electronics specifically for this type of vehicle and application. The sensor was built with two ring-cores using a specially developed stress-annealed CoFeSiB amorphous ribbon, in order to get sufficient resolution to detect concentrations of small ferrous minerals. Finally, we report on the results of experiments performed with a real UAV in an outdoor environment, showing the efficacy of the methodology in detecting an artificial ferrous anomaly.

  6. Autonomous Aeromagnetic Surveys Using a Fluxgate Magnetometer.

    Science.gov (United States)

    Macharet, Douglas G; Perez-Imaz, Héctor I A; Rezeck, Paulo A F; Potje, Guilherme A; Benyosef, Luiz C C; Wiermann, André; Freitas, Gustavo M; Garcia, Luis G U; Campos, Mario F M

    2016-12-17

    Recent advances in the research of autonomous vehicles have showed a vast range of applications, such as exploration, surveillance and environmental monitoring. Considering the mining industry, it is possible to use such vehicles in the prospection of minerals of commercial interest beneath the ground. However, tasks such as geophysical surveys are highly dependent on specific sensors, which mostly are not designed to be used in these new range of autonomous vehicles. In this work, we propose a novel magnetic survey pipeline that aims to increase versatility, speed and robustness by using autonomous rotary-wing Unmanned Aerial Vehicles (UAVs). We also discuss the development of a state-of-the-art three-axis fluxgate, where our goal in this work was to refine and adjust the sensor topology and coupled electronics specifically for this type of vehicle and application. The sensor was built with two ring-cores using a specially developed stress-annealed CoFeSiB amorphous ribbon, in order to get sufficient resolution to detect concentrations of small ferrous minerals. Finally, we report on the results of experiments performed with a real UAV in an outdoor environment, showing the efficacy of the methodology in detecting an artificial ferrous anomaly.

  7. Airborne gamma-ray spectrometer and magnetometer survey. Volume I. Final report

    International Nuclear Information System (INIS)

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Mariposa, California and Nevada; Fresno, California; and Bakersfield, Caifornia 1:250,000 National Topographic Map Series (NTMS) 1 0 x 2 0 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance (ARR) program, which in turn is a part of the National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  8. Airborne gamma-ray spectrometer and magnetometer survey: Peoria, Decater, Belleville Quadrangles, (IL). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Peoria, Decatur, and Belleville, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton procession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  9. Development of a nuclear precession magnetometer

    International Nuclear Information System (INIS)

    Virgens Alves, J.G. das.

    1983-12-01

    The objective of this thesis was to develop a proton precession magnetometer for geophysical prospecting and base stations. The proton procession magnetometer measures the total magnetic fields intensity. It operates on the basis of nuclear magnetic resonance by determining the processing frequency of protons of a non viscous liquid in the terrestrial magnetic fields. The instrument was tested in field to evaluate signal/noise ratio, supportable gradient and battery consumption. Application test was carried out to take diurnal variation data and, reconnaissance and detail surveys data on an archaeological site in the Marajo Island-Pa. The test results were confronted with two commercial magnetometers-GP-70, McPhar e G-816, Geometric - and, with data from Observatorio Magnetico Ilha de Tatuoca as well. For all cases, the data comparison showed a good performance of the magnetometer tested. (author)

  10. Airborne gamma-ray spectrometer and magnetometer survey, Sagavanirktok Quadrangle, Alaska. Volume I. Final report

    International Nuclear Information System (INIS)

    1981-03-01

    The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Sagavanirktok map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of eight uranium anomalies have been outlined on the interpretation map. However, all of these zones are only weakly to moderately anomalous. None are thought to be indicative of local enrichment of uranium to economically significant levels. No follow-up work is recommended

  11. Airborne gamma-ray spectrometer and magnetometer survey: Lund quadrangle, Ely quadrangle, Nevada. Volume I. Final report

    International Nuclear Information System (INIS)

    1980-01-01

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Ely and Lund 1:250,000 National Topographic Map Series (NTMS quadrangle maps). The survey was part of DOE's National Uranium Resource Evaluation (NURE) Aerial Radiometric Reconnaissance program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and interpretation methodology. Volume II contains the data displays for a quadrangle and the interpretation results

  12. Magnetic profiling of the San Andreas Fault using a dual magnetometer UAV aerial survey system.

    Science.gov (United States)

    Abbate, J. A.; Angelopoulos, V.; Masongsong, E. V.; Yang, J.; Medina, H. R.; Moon, S.; Davis, P. M.

    2017-12-01

    Aeromagnetic survey methods using planes are more time-effective than hand-held methods, but can be far more expensive per unit area unless large areas are covered. The availability of low cost UAVs and low cost, lightweight fluxgate magnetometers (FGMs) allows, with proper offset determination and stray fields correction, for low-cost magnetic surveys. Towards that end, we have developed a custom multicopter UAV for magnetic mapping using a dual 3-axis fluxgate magnetometer system: the GEOphysical Drone Enhanced Survey Instrument (GEODESI). A high precision sensor measures the UAV's position and attitude (roll, pitch, and yaw) and is recorded using a custom Arduino data processing system. The two FGMs (in-board and out-board) are placed on two ends of a vertical 1m boom attached to the base of the UAV. The in-board FGM is most sensitive to stray fields from the UAV and its signal is used, after scaling, to clean the signal of the out-board FGM from the vehicle noise. The FGMs record three orthogonal components of the magnetic field in the UAV body coordinates which are then transformed into a north-east-down coordinate system using a rotation matrix determined from the roll-pitch-yaw attitude data. This ensures knowledge of the direction of all three field components enabling us to perform inverse modeling of magnetic anomalies with greater accuracy than total or vertical field measurements used in the past. Field tests were performed at Dragon's Back Pressure Ridge in the Carrizo Plain of California, where there is a known crossing of the San Andreas Fault. Our data and models were compared to previously acquired LiDAR and hand-held magnetometer measurements. Further tests will be carried out to solidify our results and streamline our processing for educational use in the classroom and student field training.

  13. Airborne gamma-ray spectrometer and magnetometer survey: Harrison Bay Quadrangle, Alaska. Final report, Volume 1

    International Nuclear Information System (INIS)

    1981-02-01

    During the months of July and August of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 3 0 x 1 0 and one (1) 4 0 x 1 0 NTMS quadrangles of the Alaska North Slope. These include the Barrow, Wainwright, Meade River, Teshekpuk, Harrison Bay, Beechey Point, Point Lay, Utukok River, Lookout Ridge, Ikpikpuk River, Umiat, and Sagavanirktok quadrangles. This report discusses the results obtained over the Harrison Bay map area

  14. Airborne gamma-ray spectrometer and magnetometer survey: Aberdeen quadrangle, South Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    During the months of June through October, 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. This report discusses the results obtained over the Aberdeen, South Dakota map area. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps

  15. Airborne gamma-ray spectrometer and magnetometer survey: north/south tieline. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted along the 99 0 longitude meridian from the Canadian border southward to the Mexican border. A total of 1555 line miles of geophysical data were acquired and, subsequently, compiled. The north-south tieline was flown as part of the National Uranium Resources Evaluation. NURE is a program of the US Department of Energy's Grand Junction, Colorado, office to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  16. Airborne gamma-ray spectrometer and magnetometer survey, Point Lay Quadrangle, Alaska. Volume I. Final report

    International Nuclear Information System (INIS)

    1981-02-01

    The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Point Lay map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of six uranium anomalies have been indicated on the interpretation map. All six are only weakly to moderately anomalous in either uranium or the uranium ratios. None of these are thought to be of any economic significance. No follow-up work is recommended for the Point Lay Quadrangle

  17. Airborne gamma-ray spectrometer and magnetometer survey, Wainwright Quadrangle, Alaska. Final report

    International Nuclear Information System (INIS)

    1981-03-01

    The results obtained from a gamma-ray spectrometer and magnetometer survey over the Wainwright map area of Alaska are presented. Based on the criteria outlined in the general section of interpretation, a total of seven uranium anomalies have been outlined on the interpretation map. With the exception of Anomaly 1, all are located over the higher terrain of the foothills in the southern portion of the quadrangle. All seven anomalies are only weakly to moderately anomalous. There are no indications anywhere within the area of any significant preferential accumulations of uranium. None of the anomalies are thought to be of any economic importance. No follow-up work is recommended

  18. Airborne gamma-ray spectrometer and magnetometer survey, Meade River Quadrangle, Alaska. Final report

    International Nuclear Information System (INIS)

    1981-02-01

    The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Meade River map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of eight uranium anomalies have been outlined on the interpretation map. Most of these are only weakly to moderately anomalous. Zones 3 and 7 are relatively better than the others though none of the anomalies are thought to be of any economic significance. No follow-up work is recommended

  19. Airborne gamma-ray spectrometer and magnetometer survey, Devils Lake quadrangle, North Dakota. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    During the months of June through October, 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. This report discusses the results obtained over the Devil's Lake map area of North Dakota. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps

  20. Geophysical Surveying of Shallow Magnetic Anomalies Using the iPhone Magnetometer

    Science.gov (United States)

    Opdyke, P.; Dudley, C.; Louie, J. N.

    2012-12-01

    This investigation examined whether the 3-axis Hall-effect magnetometer in the Apple iPhone 3GS can function as an effective shallow magnetic survey instrument. The xSensor Pro app from Crossbow Systems allows recoding of all three sensor components along with the GPS location, at a frequency of 1.0, 4.0, 16.0, and 32.0 Hz. If the iPhone proves successful in collecting useful magnetic data, then geophysicists and especially educators would have a new tool for high-density geophysical mapping. No-contract iPhones that can connect with WiFi can be obtained for about $400, allowing deployment of large numbers of instruments. iPhones with the xSensor Pro app surveyed in parallel with an Overhauser GEM system magnetometer (1 nT sensitivity) to test this idea. Anderson Bay, located on the Pyramid Lake Paiute Reservation, provided a rural survey location free from cultural interference. xSensor Pro, logged each component's intensity and the GPS location at a frequency of four measurements per second. Two Overhauser units functioned as a base unit and a roving unit. The roving unit collected total field at set points located with a handheld GPS. Comparing the total field computed from the iPhone components against that collected by the Overhauser establishes the level of anomalies that the iPhone can detect. iPhone total-field measurements commonly vary by 200 nT from point to point, so a spatial-temporal average over 25 seconds produces a smoothed signal for comparison. Preliminary analysis of the iPhone results show that the data do not accurately correlate to the total field collected by the Overhauser for any anomaly of less than 200 nT.

  1. Airborne gamma-ray spectrometer and magnetometer survey, Mitchell Quadrangle, South Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Mitchell map area. The purpose of this program is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1479 line miles are in this quadrangle

  2. Airborne gamma-ray spectrometer and magnetometer survey, New Rockford Quadrangle, North Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the New Rockford map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1397 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  3. Airborne gamma-ray spectrometer and magnetometer survey: Huron quadrangle, South Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Huron map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1459 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  4. Airborne gamma-ray spectrometer and magnetometer survey Coos Bay, Oregon. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    During the months of August, September, and October of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Coos Bay, Oregon, map area. Line spacing was generally six miles for east/west traverses and eighteen miles for north/south tie lines over the northern one-half of the area. Traverses and tie lines were flown at three miles and twelve miles respectively over the southern one-half of the area. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 863.8 line miles are in this quadrangle

  5. Airborne gamma-ray spectrometer and magnetometer survey: Alturas quadrangle, California. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Alturas, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1631.6 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  6. Airborne gamma-ray spectrometer and magnetometer survey: Susanville quadrangle, California. Final report

    International Nuclear Information System (INIS)

    1981-05-01

    An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Susanville, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1642.8 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

  7. Airborne gamma-ray spectrometer and magnetometer survey: Barrow Quadrangle, Alaska. Final report. Volume I

    International Nuclear Information System (INIS)

    1981-03-01

    During the months of July-August 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 3 0 x 1 0 and one (1) 4 0 x 1 0 NTMS quadrangles of the Alaskan North Slope. This report discusses the results obtained over the Barrow map area. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps. The histograms and the multiparameter profiles are presented with the anomaly maps and flight path map in a separate bound volume. Complete data listings of both the reduced single record and the reduced averaged record data are found in the back of this report. The format of the printout of the microfiches and the format of the data files delivered on magnetic tape are in accordance with the specifications of the BFEC 1200-C and are described in appendices F through L of this report

  8. A survey of flux transfer events recorded by the UKS spacecraft magnetometer

    International Nuclear Information System (INIS)

    Southwood, D.J.; Saunders, M.A.; Dunlop, M.W.; Mier-Jedrzejowicz, W.A.C.; Rijnbeek, R.P.

    1986-01-01

    The UKS spacecraft operated from August 1984 through to January 1985. During that time, it made multiple crossings of the magnetopause in local time sectors extending from mid-afternoon to just behind the dawn meridian. We have surveyed the magnetometer records from these magnetopause encounters and have compiled a catalogue of flux transfer events. Using the catalogue, we find the FTE occurrence determined from the UKS data set is substantially less than that detected using data from the early ISEE 1/2 spacecraft orbits. The UKS data set shows a correlation between FTE occurrence and southward external magnetic field, but there are several instances of passes in which no FTEs are detected but for which the external field was unambiguously southward. The passes with the largest number of events are those for which the field outside the magnetopause has a large Bsub(M) component. We conclude that the lower latitude of the UKS encounters is responsible for the discrepancy with the ISEE occurrence. The most likely source region appears to be near the subsolar region. (author)

  9. Airborne gamma-ray spectrometer and magnetometer survey: Norton Bay Quadrangle (Alaska). Final report

    International Nuclear Information System (INIS)

    1980-01-01

    During the months of July, August, and September 1979, an airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten 3 0 x 1 0 NTMS quadrangles of West-Central Alaska. The results obtained over the Norton Bay Map area are discussed. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps and flight path maps. The histograms and the multiparameter are presented with the anomaly maps and flight path map in a separate volume. A total of twenty (20) uranium anomalies have been indicated on the interpretation map. No thorium anomalies were found. The uranium anomalies are all weak and generally have only U/K or U/T expression. Often the uranium concentration within the zone is low, and generally is less than 2.5 ppM. Only zones 9, with an average of 3.0 ppM eU, and 14, with 2.6 ppm have above average uranium content. Zone 14 is also the only uranium anomaly with combined U/K and U/T ratio anomalies. No single uranium anomaly is believed to represent an economic follow-up target. The most prospective area appears to be the elongate zone of generally high uranium content, formed by the deposits of the Shaktolik group, to the east of the Ungalik conglomerate. This zone flanks an elongate area of relatively strong shallow magnetic sources, interpreted to be related to a monozonitic intrusive of which the Christmas mountain forms part. This intrusive rock contains in other neighboring areas often high thorium and uranium concentrations and may here as well served as a possible source of uranium deposits

  10. Airborne gamma-ray spectrometer and magnetometer survey: Forsyth quadrangle, Round Up quadrangle, Hardin quadrangle (Montana), Sheridan quadrangle, (Wyoming). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Forsyth, Hardin, and Sheridan, and Roundup, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration Pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  11. Airborne gamma-ray spectrometer and magnetometer survey: Crescent Quadrangle, Burns Quadrangle, Canyon City Quadrangle, Bend Quadrangle, Salem Quadrangle (Oregon). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    An airborne combining radiometric and magnetic survey was performed for the Department of Energy over the area covered by the Burns, Crescent, Canyon City, Bend, and Salem, Washington 1:250,000 National Topographic Map Series, 1 0 x 2 0 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance program, which is in turn a part of the National Uranium Resource Evaluation program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

  12. Fluxgate vector magnetometers: A multisensor device for ground, UAV, and airborne magnetic surveys

    OpenAIRE

    Gavazzi , Bruno; Le Maire , Pauline; Munschy , Marc; Dechamp , Aline

    2016-01-01

    International audience; Fluxgate magnetometers are quite uncommon in geophysics. Recent advances in calibration of the devices and their magnetic compensation ability led Institut de Physique du Globe de Stras-bourg to develop instruments for magnetic measurements at different scales for a wide range of applications — from submetric measurements on the ground to aircraft-conducted acquisition by unmanned aerial vehicles (UAVs). A case study on the aerial military base BA112 shows the usefulne...

  13. Attitude-independent magnetometer calibration for marine magnetic surveys: regularization issue

    International Nuclear Information System (INIS)

    Wu, Zhitian; Hu, Xiaoping; Wu, Meiping; Cao, Juliang

    2013-01-01

    We have developed an attitude-independent calibration method for a shipboard magnetometer to estimate the absolute strength of the geomagnetic field from a marine vessel. The three-axis magnetometer to be calibrated is fixed on a rigid aluminium boom ahead of the vessel to reduce the magnetic effect of the vessel. Due to the constrained manoeuvres of the vessel, a linear observational equation system for calibration parameter estimation is severely ill-posed. Consequently, if the issue is not mitigated, traditional calibration methods may result in unreliable or unsuccessful solutions. In this paper, the ill-posed problem is solved by using the truncated total least squares (TTLS) technique. This method takes advantage of simultaneously considering errors on both sides of the observation equation. Furthermore, the TTLS method suits strongly ill-posed problems. Simulations and experiments have been performed to assess the performance of the TTLS method and to compare it with the performance of conventional regularization approaches such as the Tikhonov method and truncated single value decomposition. The results show that the proposed algorithm can effectively mitigate the ill-posed problem and is more stable than the compared regularization methods for magnetometer calibration applications. (paper)

  14. Natural remanent magnetization and rock magnetic parameters from the North-East Atlantic continental margin : Insights from a new, automated cryogenic magnetometer at the Geological Survey of Norway

    Science.gov (United States)

    Klug, Martin; Fabian, Karl; Knies, Jochen; Sauer, Simone

    2017-04-01

    Natural remanent magnetization (NRM) and rock magnetic parameters from two locations, West Barents Sea ( 71.6°N,16.2°E) and Vestnesa Ridge, NW Svalbard ( 79.0°N, 6.9°E), were acquired using a new, automatically operating cryogenic magnetometer system at the Geological Survey of Norway. The magnetometer setup comprises an automated robot sample feeding, dynamic operation and measurement monitoring, and customised output-to-database data handling. The setup is designed to dynamically enable a variety of parallel measurements with several coupled devices (e.g. balance, MS2B) to effectively use dead-time in between the otherwise time-consuming measurements with the cryogen magnetometer. Web-based access allows remote quality control and interaction 24/7 and enables high sample throughput. The magnetic properties are combined with geophysical, geochemical measurements and optical imaging, both radiographic and colour images, from high-resolution core-logging. The multidisciplinary approach enables determination and interpretation of content and formation of the magnetic fraction, and its development during diagenetic processes. Besides palaeomagnetic age determination the results offer the opportunity to study sediment transformation processes that have implications for the burial and degradation of organic matter. The results also help to understand long and short-term variability of sediment accumulation. Chemical sediment stability is directly linked to environmental and climate variability in the polar marine environment during the recent past.

  15. The MASCOT Magnetometer

    Science.gov (United States)

    Herčík, David; Auster, Hans-Ulrich; Blum, Jürgen; Fornaçon, Karl-Heinz; Fujimoto, Masaki; Gebauer, Kathrin; Güttler, Carsten; Hillenmaier, Olaf; Hördt, Andreas; Liebert, Evelyn; Matsuoka, Ayako; Nomura, Reiko; Richter, Ingo; Stoll, Bernd; Weiss, Benjamin P.; Glassmeier, Karl-Heinz

    2017-07-01

    The Mobile Asteroid Scout (MASCOT) is a small lander on board the Hayabusa2 mission of the Japan Aerospace Exploration Agency to the asteroid 162173 Ryugu. Among the instruments on MASCOT is a fluxgate magnetometer, the MASCOT Magnetometer (MasMag). The magnetometer is a lightweight (˜280 g) and low power (˜0.5 W) triaxial fluxgate magnetometer. Magnetic field measurements during the landing period and during the surface operational phase shall provide information about any intrinsic magnetic field of the asteroid and its remanent magnetization. This could provide important constraints on planet formation and the thermal and aqueous evolution of primitive asteroids.

  16. Tuned cavity magnetometer sensitivity.

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat; Schwindt, Peter

    2009-09-01

    We have developed a high sensitivity (magnetometer that utilizes a novel optical (interferometric) detection technique. Further miniaturization and low-power operation are key advantages of this magnetometer, when compared to systems using SQUIDs which require liquid Helium temperatures and associated overhead to achieve similar sensitivity levels.

  17. Fluxgate vector magnetometers: Compensated multi-sensor devices for ground, UAV and airborne magnetic survey for various application in near surface geophysics

    Science.gov (United States)

    Gavazzi, Bruno; Le Maire, Pauline; Munschy, Marc; Dechamp, Aline

    2017-04-01

    Fluxgate 3-components magnetometer is the kind of magnetometer which offers the lightest weight and lowest power consumption for the measurement of the intensity of the magnetic field. Moreover, vector measurements make it the only kind of magnetometer allowing compensation of magnetic perturbations due to the equipment carried with it. Unfortunately, Fluxgate magnetometers are quite uncommon in near surface geophysics due to the difficulty to calibrate them precisely. The recent advances in calibration of the sensors and magnetic compensation of the devices from a simple process on the field led Institut de Physique du Globe de Strasbourg to develop instruments for georeferenced magnetic measurements at different scales - from submetric measurements on the ground to aircraft-conducted acquisition through the wide range offered by unmanned aerial vehicles (UAVs) - with a precision in the order of 1 nT. Such equipment is used for different kind of application: structural geology, pipes and UXO detection, archaeology.

  18. Tuned optical cavity magnetometer

    Science.gov (United States)

    Okandan, Murat; Schwindt, Peter

    2010-11-02

    An atomic magnetometer is disclosed which utilizes an optical cavity formed from a grating and a mirror, with a vapor cell containing an alkali metal vapor located inside the optical cavity. Lasers are used to magnetically polarize the alkali metal vapor and to probe the vapor and generate a diffracted laser beam which can be used to sense a magnetic field. Electrostatic actuators can be used in the magnetometer for positioning of the mirror, or for modulation thereof. Another optical cavity can also be formed from the mirror and a second grating for sensing, adjusting, or stabilizing the position of the mirror.

  19. GOES Space Environment Monitor, Magnetometer

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Three orthogonal flux-gate magnetometer elements, (spinning twin fluxgate magnetometer prior to GOES-8) provide magnetic field measurements in three mutually...

  20. The Magnetospheric Multiscale Magnetometers

    Science.gov (United States)

    Russell, C. T.; Anderson, B. J.; Baumjohann, W.; Bromund, K. R.; Dearborn, D.; Fischer, D.; Le, G.; Leinweber, H. K.; Leneman, D.; Magnes, W.; hide

    2014-01-01

    The success of the Magnetospheric Multiscale mission depends on the accurate measurement of the magnetic field on all four spacecraft. To ensure this success, two independently designed and built fluxgate magnetometers were developed, avoiding single-point failures. The magnetometers were dubbed the digital fluxgate (DFG), which uses an ASIC implementation and was supplied by the Space Research Institute of the Austrian Academy of Sciences and the analogue magnetometer (AFG) with a more traditional circuit board design supplied by the University of California, Los Angeles. A stringent magnetic cleanliness program was executed under the supervision of the Johns Hopkins University,s Applied Physics Laboratory. To achieve mission objectives, the calibration determined on the ground will be refined in space to ensure all eight magnetometers are precisely inter-calibrated. Near real-time data plays a key role in the transmission of high-resolution observations stored onboard so rapid processing of the low-resolution data is required. This article describes these instruments, the magnetic cleanliness program, and the instrument pre-launch calibrations, the planned in-flight calibration program, and the information flow that provides the data on the rapid time scale needed for mission success.

  1. THOR Fluxgate Magnetometer (MAG)

    Science.gov (United States)

    Nakamura, Rumi; Eastwood, Jonathan; Magnes, Werner; Carr, Christopher, M.; O'Brien, Helen, L.; Narita, Yasuhito; K, Chen, Christopher H.; Berghofer, Gerhard; Valavanoglou, Aris; Delva, Magda; Plaschke, Ferdinand; Cupido, Emanuele; Soucek, Jan

    2017-04-01

    Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. The fluxgate Magnetometer (MAG) measures the background to low frequency magnetic field. The high sensitivity measurements of MAG enable to characterize the nature of turbulent fluctuations as well as the large-scale context. MAG will provide the reference system for determining anisotropy of field fluctuations, pitch-angle and gyro-phase of particles. The design of the magnetometer consists of two tri-axial sensors and the related magnetometer electronics; the electronics are hosted on printed circuit boards in the common electronics box of the fields and wave processor (FWP). A fully redundant two- sensor system mounted on a common boom and the new miniaturized low noise design based on MMS and Solar Orbiter instruments enable accurate measurement throughout the region of interest for THOR science. The usage of the common electronics hosted by FWP guarantees to fulfill the required timing accuracy with other fields measurements. These improvements are important to obtain precise measurements of magnetic field, which is essential to estimate basic plasma parameters and correctly identify the spatial and temporal scales of the turbulence. Furthermore, THOR MAG provides high quality data with sufficient overlap with the Search Coil Magnetometer (SCM) in frequency space to obtain full coverage of the wave forms over all the frequencies necessary to obtain the full solar wind turbulence spectrum from MHD to kinetic range with sufficient accuracy. We discuss the role of MAG in THOR key science questions and present the new developments during Phase A such as the finalised instrument design, MAG relevant requirement, and new calibraion schemes.

  2. The IRM fluxgate magnetometer

    Science.gov (United States)

    Luehr, H.; Kloecker, N.; Oelschlaegel, W.; Haeusler, B.; Acuna, M.

    1985-01-01

    This report describes the three-axis fluxgate magnetometer instrument on board the AMPTE IRM spacecraft. Important features of the instrument are its wide dynamic range (0.1-60,000 nT), a high resolution (16-bit analog to digital conversion) and the capability to operate automatically or via telecommand in two gain states. In addition, the wave activity is monitored in all three components up to 50 Hz. Inflight checkout proved the nominal functioning of the instrument in all modes.

  3. Cryostats for SQUID magnetometers

    International Nuclear Information System (INIS)

    Testard, O.A.; Locatelli, M.

    1982-05-01

    A non metallic and non magnetic cryostat, with a very low thermal budget and a container type autonomy was developed, to condition S.Q.U.I.D. magnetometers which maximum sensitivity reaches 10 -14 Tesla Hertzsup(-1/2). This instrumentation puts in hand new concepts of composite materials, thermal shock and vibration resistant, multilayer thermal radiative insulation also to the prouve of vibrations with thermal equivalent emissivity lower than 10 -3

  4. Vector Magnetometer Application with Moving Carriers

    Directory of Open Access Journals (Sweden)

    Andrii Prystai

    2016-12-01

    Full Text Available In magnetic prospecting the aeromagnetic survey is a widespread method used for research in large territories or in the areas with difficult access (forests, swamps, shallow waters. At present, a new type of mobile carriers – remotely piloted vehicles or drones – is becoming very common. The drones supplied by magnetometer can be also used for underground utility location (for example, steel and concrete constructions, buried power cables, to name a few. For aeromagnetic survey, obtaining of 3-component magnetic field data gives higher processing precision, so the fluxgate magnetometers (FGM seem to be the most preferable by reason of low weight, noise, power consumption and costs. During movement of FGM fixed to a drone practically permanent attitude changes in the Earth’s magnetic field arises with corresponding changes of its projection at FGM axes. Also the electromagnetic interference from the drone motor and uncontrolled oscillations of drone and suspension are the factors which limit the magnetometer sensitivity level. Aroused because of this, signals significantly exceed the expected signals from a studied object and so should be removed by proper interference filtration and use of stabilized towed construction, as well as at data processing. To find the necessary resolution threshold of a drone-portable FGM, the modeling was made to estimate magnetic field value from a small sphere about 1 cm radius at the minimal altitude of drone flight and it was shown that such a small object can be reliably detected if the FGM noise level is less than 0.15 nT. Next requirement is the necessity to decrease as much as possible the FGM power consumption with retention of low noise level. Finally, because of drone movement, the broadening of a frequency range should be done. The LEMI-026 magnetometer was developed satisfying all requirements to the drone-mounted device. The field tests were successfully performed using two of LEMI-026

  5. Scalar Calibration of Vector Magnetometers

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Brauer, Peter; Primdahl, Fritz

    2000-01-01

    The calibration parameters of a vector magnetometer are estimated only by the use of a scalar reference magnetometer. The method presented in this paper differs from those previously reported in its linearized parametrization. This allows the determination of three offsets or signals in the absence...

  6. High Accuracy Vector Helium Magnetometer

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed HAVHM instrument is a laser-pumped helium magnetometer with both triaxial vector and omnidirectional scalar measurement capabilities in a single...

  7. Optical Magnetometer Incorporating Photonic Crystals

    Science.gov (United States)

    Kulikov, Igor; Florescu, Lucia

    2007-01-01

    According to a proposal, photonic crystals would be used to greatly increase the sensitivities of optical magnetometers that are already regarded as ultrasensitive. The proposal applies, more specifically, to a state-of-the-art type of quantum coherent magnetometer that exploits the electromagnetically-induced-transparency (EIT) method for determining a small change in a magnetic field indirectly via measurement of the shift, induced by that change, in the hyperfine levels of resonant atoms exposed to the field.

  8. Calibration of a fluxgate magnetometer array and its application in magnetic object localization

    International Nuclear Information System (INIS)

    Pang, Hongfeng; Luo, Shitu; Zhang, Qi; Li, Ji; Chen, Dixiang; Pan, Mengchun; Luo, Feilu

    2013-01-01

    The magnetometer array is effective for magnetic object detection and localization. Calibration is important to improve the accuracy of the magnetometer array. A magnetic sensor array built with four three-axis DM-050 fluxgate magnetometers is designed, which is connected by a cross aluminum frame. In order to improve the accuracy of the magnetometer array, a calibration process is presented. The calibration process includes magnetometer calibration, coordinate transformation and misalignment calibration. The calibration system consists of a magnetic sensor array, a GSM-19T proton magnetometer, a two-dimensional nonmagnetic rotation platform, a 12 V-dc portable power device and two portable computers. After magnetometer calibration, the RMS error has been decreased from an original value of 125.559 nT to a final value of 1.711 nT (a factor of 74). After alignment, the RMS error of misalignment has been decreased from 1322.3 to 6.0 nT (a factor of 220). Then, the calibrated array deployed on the nonmagnetic rotation platform is used for ferromagnetic object localization. Experimental results show that the estimated errors of X, Y and Z axes are −0.049 m, 0.008 m and 0.025 m, respectively. Thus, the magnetometer array is effective for magnetic object detection and localization in three dimensions. (paper)

  9. Calibration of a fluxgate magnetometer array and its application in magnetic object localization

    Science.gov (United States)

    Pang, Hongfeng; Luo, Shitu; Zhang, Qi; Li, Ji; Chen, Dixiang; Pan, Mengchun; Luo, Feilu

    2013-07-01

    The magnetometer array is effective for magnetic object detection and localization. Calibration is important to improve the accuracy of the magnetometer array. A magnetic sensor array built with four three-axis DM-050 fluxgate magnetometers is designed, which is connected by a cross aluminum frame. In order to improve the accuracy of the magnetometer array, a calibration process is presented. The calibration process includes magnetometer calibration, coordinate transformation and misalignment calibration. The calibration system consists of a magnetic sensor array, a GSM-19T proton magnetometer, a two-dimensional nonmagnetic rotation platform, a 12 V-dc portable power device and two portable computers. After magnetometer calibration, the RMS error has been decreased from an original value of 125.559 nT to a final value of 1.711 nT (a factor of 74). After alignment, the RMS error of misalignment has been decreased from 1322.3 to 6.0 nT (a factor of 220). Then, the calibrated array deployed on the nonmagnetic rotation platform is used for ferromagnetic object localization. Experimental results show that the estimated errors of X, Y and Z axes are -0.049 m, 0.008 m and 0.025 m, respectively. Thus, the magnetometer array is effective for magnetic object detection and localization in three dimensions.

  10. Calibration of three-axis magnetometers with differential evolution algorithm

    International Nuclear Information System (INIS)

    Pang, Hongfeng; Zhang, Qi; Wang, Wei; Wang, Junya; Li, Ji; Luo, Shitu; Wan, Chengbiao; Chen, Dixiang; Pan, Mengchun; Luo, Feilu

    2013-01-01

    The accuracy of three-axis magnetometers is influenced by different scale and bias of each axis and nonorthogonality between axes. One limitation of traditional iteration methods is that initial parameters influence the calibration, thus leading to the local optimal or wrong results. In this paper, a new method is proposed to calibrate three-axis magnetometers. To employ this method, a nonmagnetic rotation platform, a proton magnetometer, a DM-050 three-axis magnetometer and the differential evolution (DE) algorithm are used. The performance of this calibration method is analyzed with simulation and experiment. In simulation, the calibration results of DE, unscented Kalman filter (UKF), recursive least squares (RLS) and genetic algorithm (GA) are compared. RMS error using DE is least, which is reduced from 81.233 nT to 1.567 nT. Experimental results show that comparing with UKF, RLS and GA, the DE algorithm has not only the least calibration error but also the best robustness. After calibration, RMS error is reduced from 68.914 nT to 2.919 nT. In addition, the DE algorithm is not sensitive to initial parameters, which is an important advantage compared with traditional iteration algorithms. The proposed algorithm can avoid the troublesome procedure to select suitable initial parameters, thus it can improve the calibration performance of three-axis magnetometers. - Highlights: • The calibration results and robustness of UKF, GA, RLS and DE algorithm are analyzed. • Calibration error of DE is the least in simulation and experiment. • Comparing with traditional calibration algorithms, DE is not sensitive to initial parameters. • It can improve the calibration performance of three-axis magnetometers

  11. Magnetogama: an open schematic magnetometer

    Science.gov (United States)

    Wahyudi; Khakhim, Nurul; Kuntoro, Tri; Mardiatno, Djati; Rakhman, Afif; Setyo Handaru, Anas; Akhmad Mufaqih, Adien; Marwan Irnaka, Theodosius

    2017-09-01

    Magnetogama is an open schematic hand-assembled fluxgate magnetometer. Compared to another magnetometer, Magnetogama has more benefit concerning its price and its ease of use. Practically Magnetogama can be utilized either in land or attached to an unmanned aerial vehicle (UAV). Magnetogama was designed to give open access to a cheap and accurate alternative to magnetometer sensor. Therefore it can be used as a standard design which is directly applicable to the low-budget company or education purposes. Schematic, code and several verification tests were presented in this article ensuring its reproducibility. Magnetogama has been tested with two kind of tests: a comparison with two nearest observatories at Learmonth (LRM) and Kakadu (KDU) and the response of magnetic substance.

  12. Magnetogama: an open schematic magnetometer

    Directory of Open Access Journals (Sweden)

    Wahyudi

    2017-09-01

    Full Text Available Magnetogama is an open schematic hand-assembled fluxgate magnetometer. Compared to another magnetometer, Magnetogama has more benefit concerning its price and its ease of use. Practically Magnetogama can be utilized either in land or attached to an unmanned aerial vehicle (UAV. Magnetogama was designed to give open access to a cheap and accurate alternative to magnetometer sensor. Therefore it can be used as a standard design which is directly applicable to the low-budget company or education purposes. Schematic, code and several verification tests were presented in this article ensuring its reproducibility. Magnetogama has been tested with two kind of tests: a comparison with two nearest observatories at Learmonth (LRM and Kakadu (KDU and the response of magnetic substance.

  13. Digital fluxgate magnetometer: design notes

    International Nuclear Information System (INIS)

    Belyayev, Serhiy; Ivchenko, Nickolay

    2015-01-01

    We presented an approach to understanding the performance of a fully digital fluxgate magnetometer. All elements of the design are important for the performance of the instrument, and the presence of the digital feed-back loop introduces certain peculiarities affecting the noise and dynamic performance of the instrument. Ultimately, the quantisation noise of the digital to analogue converter is found to dominate the noise of the current design, although noise shaping alleviates its effect to some extent. An example of magnetometer measurements on board a sounding rocket is presented, and ways to further improve the performance of the instrument are discussed. (paper)

  14. Digital fluxgate magnetometer: design notes

    Science.gov (United States)

    Belyayev, Serhiy; Ivchenko, Nickolay

    2015-12-01

    We presented an approach to understanding the performance of a fully digital fluxgate magnetometer. All elements of the design are important for the performance of the instrument, and the presence of the digital feed-back loop introduces certain peculiarities affecting the noise and dynamic performance of the instrument. Ultimately, the quantisation noise of the digital to analogue converter is found to dominate the noise of the current design, although noise shaping alleviates its effect to some extent. An example of magnetometer measurements on board a sounding rocket is presented, and ways to further improve the performance of the instrument are discussed.

  15. Low Cost, Low Power, High Sensitivity Magnetometer

    Science.gov (United States)

    2008-12-01

    which are used to measure the small magnetic signals from brain. Other types of vector magnetometers are fluxgate , coil based, and magnetoresistance...concentrator with the magnetometer currently used in Army multimodal sensor systems, the Brown fluxgate . One sees the MEMS fluxgate magnetometer is...Guedes, A.; et al., 2008: Hybrid - LOW COST, LOW POWER, HIGH SENSITIVITY MAGNETOMETER A.S. Edelstein*, James E. Burnette, Greg A. Fischer, M.G

  16. An Arduino-Based Magnetometer

    Science.gov (United States)

    McCaughey, Mike

    2017-01-01

    An Arduino-based system with a triple axis magnetometer chip may be used to plot both the strength and direction of the magnetic field of a magnet directly on a sheet of paper. Before taking measurements, it is necessary either to correct for or to eliminate soft and hard iron effects. The same sensor may be used to determine the presence of soft…

  17. Magnetometer calibration and test procedure

    International Nuclear Information System (INIS)

    Squier, D.M.

    1997-01-01

    Nuclear waste has been sluiced and pumped from storage tank 241-AX-104, leaving a contaminated heel volume. These operations did not include measurements of the removed waste volume leaving an unknown heel volume in the tank. A magnetometer transducer will be lowered through tank riser ports to rest on the heel's surface. The heel thickness will control the distance between the transducer and the tank's bottom The instrument's output varies with the distance from a magnetic mass, such as the tank's steel bottom, thereby enabling a measurement of the heel depth. Measurements at several tank locations will permit an estimate of the tank's heel volume. The magnetometer's output is influenced by adjacent magnetic materials, such as the tank walls, air lift circulators or other equipment installed in the tank. An adjacent vertical steel surface produces a voltage offset in the instrument's output. Measurements near a tank wall or other tank components may be corrected by noting the offset before the instrument's output is influenced by the tank bottom. An unlevel or uneven heel surface could orient the magnetometer transducer so that it is not vertically level. The magnetometer readings are influenced by these skewed transducer orientations. The magnitude of these errors and offsets must be characterized to bound the heel volume estimate range. The data collected by this activity will be statistically analyzed by SESC to state the confidence level of the heel volume estimates. A test report will document the results of the measurements

  18. Practice Patterns Analysis of Ocular Proton Therapy Centers: The International OPTIC Survey

    International Nuclear Information System (INIS)

    Hrbacek, Jan; Mishra, Kavita K.; Kacperek, Andrzej; Dendale, Remi; Nauraye, Catherine; Auger, Michel; Herault, Joel; Daftari, Inder K.; Trofimov, Alexei V.; Shih, Helen A.; Chen, Yen-Lin E.; Denker, Andrea; Heufelder, Jens; Horwacik, Tomasz; Swakoń, Jan; Hoehr, Cornelia; Duzenli, Cheryl; Pica, Alessia; Goudjil, Farid; Mazal, Alejandro

    2016-01-01

    Purpose: To assess the planning, treatment, and follow-up strategies worldwide in dedicated proton therapy ocular programs. Methods and Materials: Ten centers from 7 countries completed a questionnaire survey with 109 queries on the eye treatment planning system (TPS), hardware/software equipment, image acquisition/registration, patient positioning, eye surveillance, beam delivery, quality assurance (QA), clinical management, and workflow. Results: Worldwide, 28,891 eye patients were treated with protons at the 10 centers as of the end of 2014. Most centers treated a vast number of ocular patients (1729 to 6369). Three centers treated fewer than 200 ocular patients. Most commonly, the centers treated uveal melanoma (UM) and other primary ocular malignancies, benign ocular tumors, conjunctival lesions, choroidal metastases, and retinoblastomas. The UM dose fractionation was generally within a standard range, whereas dosing for other ocular conditions was not standardized. The majority (80%) of centers used in common a specific ocular TPS. Variability existed in imaging registration, with magnetic resonance imaging (MRI) rarely being used in routine planning (20%). Increased patient to full-time equivalent ratios were observed by higher accruing centers (P=.0161). Generally, ophthalmologists followed up the post–radiation therapy patients, though in 40% of centers radiation oncologists also followed up the patients. Seven centers had a prospective outcomes database. All centers used a cyclotron to accelerate protons with dedicated horizontal beam lines only. QA checks (range, modulation) varied substantially across centers. Conclusions: The first worldwide multi-institutional ophthalmic proton therapy survey of the clinical and technical approach shows areas of substantial overlap and areas of progress needed to achieve sustainable and systematic management. Future international efforts include research and development for imaging and planning software upgrades

  19. Practice Patterns Analysis of Ocular Proton Therapy Centers: The International OPTIC Survey

    Energy Technology Data Exchange (ETDEWEB)

    Hrbacek, Jan, E-mail: Jan.hrbacek@psi.ch [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); Mishra, Kavita K. [Ocular Tumor Proton Therapy Program, University of California San Francisco, San Francisco, California (United States); Kacperek, Andrzej [National Proton Therapy Centre, Clatterbridge Cancer Centre, Bebington (United Kingdom); Dendale, Remi; Nauraye, Catherine; Auger, Michel [Centre de Protonthérapie d' Orsay, Institut Curie, Orsay (France); Herault, Joel [Centre Lacassagne, Nice (France); Daftari, Inder K. [Ocular Tumor Proton Therapy Program, University of California San Francisco, San Francisco, California (United States); Trofimov, Alexei V.; Shih, Helen A.; Chen, Yen-Lin E. [F. H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Denker, Andrea [Protons for Therapy, Helmholtz-Zentrum Berlin, Berlin (Germany); Heufelder, Jens [BerlinProtonen am HZB, Charité – Universitätsmedizin Berlin, Berlin (Germany); Horwacik, Tomasz; Swakoń, Jan [Institute of Nuclear Physic, Polish Academy of Sciences, Krakow (Poland); Hoehr, Cornelia; Duzenli, Cheryl [BC Cancer Agency – TRIUMF, Vancouver (Canada); Pica, Alessia [Center for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); Goudjil, Farid; Mazal, Alejandro [Centre de Protonthérapie d' Orsay, Institut Curie, Orsay (France); and others

    2016-05-01

    Purpose: To assess the planning, treatment, and follow-up strategies worldwide in dedicated proton therapy ocular programs. Methods and Materials: Ten centers from 7 countries completed a questionnaire survey with 109 queries on the eye treatment planning system (TPS), hardware/software equipment, image acquisition/registration, patient positioning, eye surveillance, beam delivery, quality assurance (QA), clinical management, and workflow. Results: Worldwide, 28,891 eye patients were treated with protons at the 10 centers as of the end of 2014. Most centers treated a vast number of ocular patients (1729 to 6369). Three centers treated fewer than 200 ocular patients. Most commonly, the centers treated uveal melanoma (UM) and other primary ocular malignancies, benign ocular tumors, conjunctival lesions, choroidal metastases, and retinoblastomas. The UM dose fractionation was generally within a standard range, whereas dosing for other ocular conditions was not standardized. The majority (80%) of centers used in common a specific ocular TPS. Variability existed in imaging registration, with magnetic resonance imaging (MRI) rarely being used in routine planning (20%). Increased patient to full-time equivalent ratios were observed by higher accruing centers (P=.0161). Generally, ophthalmologists followed up the post–radiation therapy patients, though in 40% of centers radiation oncologists also followed up the patients. Seven centers had a prospective outcomes database. All centers used a cyclotron to accelerate protons with dedicated horizontal beam lines only. QA checks (range, modulation) varied substantially across centers. Conclusions: The first worldwide multi-institutional ophthalmic proton therapy survey of the clinical and technical approach shows areas of substantial overlap and areas of progress needed to achieve sustainable and systematic management. Future international efforts include research and development for imaging and planning software upgrades

  20. LH2 Target Design & Position Survey Techniques for the MUSE experiment for Precise Proton Radius Measurement

    Science.gov (United States)

    Le Pottier, Luc; Roy, Pryiashee; Lorenzon, Wolfgang; Raymond, Richard; Steinberg, Noah; Rossi de La Fuente, Erick; MUSE (MUon proton Scattering Experiment) Collaboration

    2017-09-01

    The proton radius puzzle is a currently unresolved problem which has intrigued the scientific community, dealing with a 7 σ discrepancy between the proton radii determined from muonic hydrogen spectroscopy and electron scattering measurements. The MUon Scattering Experiment (MUSE) aims to resolve this puzzle by performing the first simultaneous elastic scattering measurements of both electrons and muons on the proton, which will allow the comparison of the radii from the two interactions with reduced systematic uncertainties. The data from this experiment is expected to provide the best test of lepton universality to date. The experiment will take place at the Paul Scherrer Institute in Switzerland in 2018. An essential component of the experiment is a liquid hydrogen (LH2) cryotarget system. Our group at the University of Michigan is responsible for the design, fabrication and installation of this system. Here we present our LH2 target cell design and fabrication techniques for successful operation at 20 K and 1 atm, and our computer vision-based target position survey system which will determine the position of the target, installed inside a vacuum chamber, with 0.01 mm or better precision at the height of the liquid hydrogen target and along the beam direction during the experiment.

  1. Induction Magnetometers – Design Peculiarities

    Directory of Open Access Journals (Sweden)

    Valeriy KOREPANOV

    2010-09-01

    Full Text Available Induction or search-coil magnetometers (IM are widely used in many branches of science and industry. The frequency range and dynamic range of IMs are probably the widest of all existing magnetometers: they are used for the measurement of magnetic field variations in the frequency band from ~10-4 till ~106 Hz with the intensities from fractions of femtotesla till tens of tesla. This explains the permanent interest to IM design and the attempts to construct the IMs with best possible parameters. The present paper deals with the peculiarities of IM design. An attempt to re-establish the correctness of priorities in the field is made and the approaches to the IM optimization and their quality estimation are described.

  2. SU-E-T-568: Neutron Dose Survey of a Compact Single Room Proton Machine

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y; Prusator, M; Islam, M; Johnson, D; Ahmad, S [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2015-06-15

    Purpose: To ensure acceptable radiation limits are maintained for those working at and near the machine during its operation, a comprehensive radiation survey was performed prior to the clinical release of Mevion S250 compact proton machine at Stephenson Oklahoma Cancer Center. Methods: The Mevion S250 proton therapy system consists of the following: a superconducting cyclotron to accelerate the proton particles, a passive double scattering system for beam shaping, and paired orthogonal x-ray imaging systems for patient setup and verification via a 6D robotic couch. All equipment is housed within a single vault of compact design. Two beam delivery applicators are available for patient treatment, offering field sizes of as great as 14 cm and 25 cm in diameter, respectively. Typical clinical dose rates are between 1 and 2 Gy/min with a fixed beam energy of 250 MeV. The large applicator (25 cm in diameter) was used in conjunction with a custom cut brass aperture to create a 20 cm x 20 cm field size at beam isocenter. A 30 cm − 30 cm − 35 cm high density plastic phantom was placed in the beam path to mimic the conditions creating patient scatter. Measurements integrated-ambient-neutron-dose-equivalence were made with a SWENDII detector. Gantry angles of 0, 90 and 180 degrees, with a maximum dose rate of 150 MU/min (for large applicator) and beam configuration of option 1 (range 25 cm and 20 cm modulation), were selected as testing conditions. At each point of interest, the highest reading was recorded at 30 cm from the barrier surface. Results: The highest neutron dose was estimated to be 0.085 mSv/year at the console area. Conclusion: All controlled areas are under 5 mSv/year and the uncontrolled areas are under 1 mSv/year. The radiation protection provided by the proton vault is of sufficient quality.

  3. Atomic magnetometer for human magnetoencephalograpy.

    Energy Technology Data Exchange (ETDEWEB)

    Schwindt, Peter; Johnson, Cort N.

    2010-12-01

    We have developed a high sensitivity (<5 fTesla/{radical}Hz), fiber-optically coupled magnetometer to detect magnetic fields produced by the human brain. This is the first demonstration of a noncryogenic sensor that could replace cryogenic superconducting quantum interference device (SQUID) magnetometers in magnetoencephalography (MEG) and is an important advance in realizing cost-effective MEG. Within the sensor, a rubidium vapor is optically pumped with 795 laser light while field-induced optical rotations are measured with 780 nm laser light. Both beams share a single optical axis to maximize simplicity and compactness. In collaboration with neuroscientists at The Mind Research Network in Albuquerque, NM, the evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer and a commercial SQUID-based MEG system with signals comparing favorably. Multi-sensor operation has been demonstrated with two AMs placed on opposite sides of the head. Straightforward miniaturization would enable high-density sensor arrays for whole-head magnetoencephalography.

  4. Airborne gamma-ray spectrometer and magnetometer survey, Durango A, B, C, and D, Colorado. Volume I. Detail area. Final report

    International Nuclear Information System (INIS)

    1983-01-01

    An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the Durango A, Durango B, Durango C, and Durango D Detail Areas of southwestern Colorado. The Durango A Detail Area is within the coverage of the Needle Mountains and Silverton 15' map sheets, and the Pole Creek Mountain, Rio Grande Pyramid, Emerald Lake, Granite Peak, Vallecito Reservoir, and Lemon Reservoir 7.5' map sheets of the National Topographic Map Series (NTMS). The Durango B Detail Area is within the coverage of the Silverton 15' map sheet and the Wetterhorn Peak, Uncompahgre Peak, Lake City, Redcloud Peak, Lake San Cristobal, Pole Creek Mountain, and Finger Mesa 7.5' map sheets of the NTMS. The Durango C Detail Area is within the coverage of the Platoro and Wolf Creek Pass 15' map sheets of the NTMS. The Durango D Detail Area is within the coverage of the Granite Lake, Cimarrona Peak, Bear Mountain, and Oakbrush Ridge 7.5' map sheets of the NTMS. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, gridded, and contoured to produce maps of the radiometric variables, uranium, potassium, and thorium; their ratios; and the residual magnetic field. These maps have been analyzed in order to produce a multi-variant analysis contour map based on the radiometric response of the individual geological units. A geochemical analysis has been performed, using the radiometric and magnetic contour maps, the multi-variant analysis map, and factor analysis techniques, to produce a geochemical analysis map for the area

  5. Two-channel recoder for magnetometer with energy-independent mass memory device

    International Nuclear Information System (INIS)

    Korzinin, V.N.; Selivanov, A.M.

    1993-01-01

    The paper describes a two-channel digit-to-analog recorder designed for converting the sequence of pulses from proton magnetometer (MMH-203) outlet; the device enables processing of the pulses and their recording in RAM and on the tape of the analog recorder. The availability of nonvolotile RAM allows to transmit digit information to a computer (BK-0010) for its further processing

  6. Vector Fluxgate Magnetometer (VMAG) Development for DSX

    Science.gov (United States)

    2010-06-03

    AFRL-RV-HA-TR-2010-1056 Vector Fluxgate Magnetometer (VMAG) Development for DSX Mark B. Moldwin UCLA Institute of Geophysics... Fluxgate Magnetometer (VMAG) Development for DSX 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62601F 6. AUTHOR(S) Mark B. Moldwin 5d. PROJECT...axis fluxgate magnetometer for the AFRL-mission. The instrument is designed to measure the medium-Earth orbit geomagnetic field with precision of 0.1

  7. Design and analysis of miniature tri-axial fluxgate magnetometer

    Science.gov (United States)

    Zhi, Menghui; Tang, Liang; Qiao, Donghai

    2017-02-01

    The detection technology of weak magnetic field is widely used in Earth resource survey and geomagnetic navigation. Useful magnetic field information can be obtained by processing and analyzing the measurement data from magnetic sensors. A miniature tri-axial fluxgate magnetometer is proposed in this paper. This miniature tri-axial fluxgate magnetometer with ring-core structure has a dynamic range of the Earth’s field ±65,000 nT, resolution of several nT. It has three independent parts placed in three perpendicular planes for measuring three orthogonal magnetic field components, respectively. A field-programmable gate array (FPGA) is used to generate stimulation signal, analog-to-digital (A/D) convertor control signal, and feedback digital-to-analog (D/A) control signal. Design and analysis details are given to improve the dynamic range, sensitivity, resolution, and linearity. Our prototype was measured and compared with a commercial standard Magson fluxgate magnetometer as a reference. The results show that our miniature fluxgate magnetometer can follow the Magson’s change trend well. When used as a magnetic compass, our prototype only has ± 0.3∘ deviation compared with standard magnetic compass.

  8. New vector/scalar Overhauser DNP magnetometers POS-4 for magnetic observatories and directional oil drilling support

    Directory of Open Access Journals (Sweden)

    Sapunov V.A., Denisov A.Y., Saveliev D.V., Soloviev A.A., Khomutov S.Y., Borodin P.B., Narkhov E.D., Sergeev A.V., Shirokov A.N.

    2016-12-01

    Full Text Available This paper covers same results of the research directed at developing an absolute vector proton magnetometer POS-4 based on the switching bias magnetic fields methods. Due to the high absolute precision and stability magnetometer POS-4 found application not only for observatories and to directional drilling support of oi and gas well. Also we discuss the some basic errors of measurements and discuss the long-term experience in the testing of magnetic observatories ART and PARATUNKA.

  9. DSCOVR Magnetometer Level 2 One Minute Averages

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Interplanetary magnetic field observations collected from magnetometer on DSCOVR satellite - 1-minute average of Level 1 data

  10. DSCOVR Magnetometer Level 2 One Second Averages

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Interplanetary magnetic field observations collected from magnetometer on DSCOVR satellite - 1-second average of Level 1 data

  11. Digitalization of highly precise fluxgate magnetometers

    DEFF Research Database (Denmark)

    Cerman, Ales; Kuna, A.; Ripka, P.

    2005-01-01

    This paper describes the theory behind all three known ways of digitalizing the fluxgate magnetometers: analogue magnetometers with digitalized output using high resolution ADC, application of the delta-sigma modulation to the sensor feedback loop and fully digital signal detection. At present time...... the Delta-Sigma ADCs are mostly used for the digitalization of the highly precise fluxgate magnetorneters. The relevant part of the paper demonstrates some pitfalls of their application studied during the design of the magnetometer for the new Czech scientific satellite MIMOSA. The part discussing...... the application of the A-E modulation to the sensor feedback loop theoretically derives the main advantage of this method-increasing of the modulation order and shows its real potential compared to the analog magnetometer with consequential digitalization. The comparison is realized on the modular magnetometer...

  12. A simple fluxgate magnetometer using amorphous alloys

    International Nuclear Information System (INIS)

    Ghatak, S.K.; Mitra, A.

    1992-01-01

    A simple fluxgate magnetometer is developed using low magnetostrictive ferromagnetic amorphous alloy acting as a sensing element. It uses the fact that the magnetization of sensing element symmetrically magnetized by a sinusoidal field contains even harmonic components in presence of dc signal field H and the amplitude of the second harmonic component of magnetization is proportional to H. The sensitivity and linearity of the magnetometer with signal field are studied for parallel configuration and the field ranging from 10 nT to 10 μT can be measured. The functioning of the magnetometer is demonstrated by studying the shielding and flux-trapping phenomena in high-Tc superconductor. (orig.)

  13. All optical vector magnetometer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I research project will investigate a novel method of operating an atomic magnetometer to simultaneously measure total magnetic fields and vector magnetic...

  14. The Fluxgate Magnetometer Simulation in Comsol Multiphysics

    Directory of Open Access Journals (Sweden)

    Kolomeytsev Andrey

    2018-01-01

    Full Text Available This article describes the fluxgate magnetometer simulation in Comsol Multiphysics software package. The simulation results coincide with the experiment described earlier. Decomposition of the output signal by the Fourier coefficients shows a frequency doubling.

  15. The Pioneer XI high field fluxgate magnetometer

    Science.gov (United States)

    Acuna, M. A.; Ness, N. F.

    1975-01-01

    The high field fluxgate magnetometer experiment flown aboard the Pioneer XI spacecraft is described. This extremely simple instrument was used to extend the spacecraft's upper-limit measurement capability by approximately an order of magnitude (from 0.14 mT to 1.00 mT) with minimum power and volume requirements. This magnetometer was designed to complement the low-field measurements provided by a helium vector magnetometer and utilizes magnetic ring core sensors with biaxial orthogonal sense coils. The instrument is a single-range, triaxial-fluxgate magnetometer capable of measuring fields of up to 1 mT along each orthogonal axis, with a maximum resolution of 1 microT.

  16. The Fluxgate Magnetometer Simulation in Comsol Multiphysics

    OpenAIRE

    Kolomeytsev Andrey; Baranov Pavel; Zatonov Ivan

    2018-01-01

    This article describes the fluxgate magnetometer simulation in Comsol Multiphysics software package. The simulation results coincide with the experiment described earlier. Decomposition of the output signal by the Fourier coefficients shows a frequency doubling.

  17. Magnetometer Data recovered from 35mm film

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The L57 CDMP recovery project takes magnetometer data on 35mm film stored at the archive's climate controlled warehouse and digitizes them.

  18. Athermal fiber laser for the SWARM absolute scalar magnetometer

    Science.gov (United States)

    Fourcault, W.; Léger, J.-M.; Costes, V.; Fratter, I.; Mondin, L.

    2017-11-01

    The Absolute Scalar Magnetometer (ASM) developed by CEA-LETI/CNES is an optically pumped 4He magnetic field sensor based on the Zeeman effect and an electronic magnetic resonance whose effects are amplified by a laser pumping process [1-2]. Consequently, the role of the laser is to pump the 4He atoms at the D0 transition as well as to allow the magnetic resonance signal detection. The ASM will be the scalar magnetic reference instrument of the three ESA Swarm satellites to be launched in 2012 in order to carry out the best ever survey of the Earth magnetic field and its temporal evolution. The sensitivity and accuracy of this magnetometer based on 4He optical pumping depend directly on the characteristics of its light source, which is the key sub-system of the sensor. We describe in this paper the selected fiber laser architecture and its wavelength stabilization scheme. Its main performance in terms of spectral emission, optical power at 1083 nm and intensity noise characteristics in the frequency bands used for the operation of the magnetometer, are then presented. Environmental testing results (thermal vacuum cycling, vibrations, shocks and ageing) are also reported at the end of this paper.

  19. ATS-6 - UCLA fluxgate magnetometer

    Science.gov (United States)

    Mcpherron, R. L.; Coleman, P. J., Jr.; Snare, R. C.

    1975-01-01

    A summary of the design of the University of California at Los Angeles' fluxgate magnetometer is presented. Instrument noise in the bandwidth 0.001 to 1.0 Hz is of order 85 m gamma. The DC field of the spacecraft transverse to the earth-pointing axis is 1.0 + or - 21 gamma in the X direction and -2.4 + or - 1.3 gamma in the Y direction. The spacecraft field parallel to this axis is less than 5 gamma. The small spacecraft field has made possible studies of the macroscopic field not previously possible at synchronous orbit. At the 96 W longitude of Applications Technology Satellite-6 (ATS-6), the earth's field is typically inclined 30 deg to the dipole axis at local noon. Most perturbations of the field are due to substorms. These consist of a rotation in the meridian to a more radial field followed by a subsequent rotation back. The rotation back is normally accompanied by transient variations in the azimuthal field. The exact timing of these perturbations is a function of satellite location and the details of substorm development.

  20. Observatory Magnetometer In-Situ Calibration

    Directory of Open Access Journals (Sweden)

    A Marusenkov

    2011-07-01

    Full Text Available An experimental validation of the in-situ calibration procedure, which allows estimating parameters of observatory magnetometers (scale factors, sensor misalignment without its operation interruption, is presented. In order to control the validity of the procedure, the records provided by two magnetometers calibrated independently in a coil system have been processed. The in-situ estimations of the parameters are in very good agreement with the values provided by the coil system calibration.

  1. Directly coupled YBCO dc SQUID magnetometers

    International Nuclear Information System (INIS)

    Petersen, P.R.E.; Shen, Y.Q.; Holst, T.; Larsen, B.H.; Sager, M.P.; Bindslev Hansen, J.

    1999-01-01

    YBa 2 Cu 3 O 7- x magnetometers have been made on 10mmx10mm MgO substrates by directly coupling the magnetometer pick-up loop to a dc SQUID with narrow strip lines. The dc SQUIDs were made with YBa 2 Cu 3 O 7-x step-edge Josephson junctions. The layout of the magnetometer pick-up loop was chosen as a compromise between maximizing the loop effective area and minimizing the loop inductance. The SQUID was designed to have L S ∼100 pH in order to obtain β L =2I 0 L S /Φ 0 approx.= 1 with the single-junction critical current I 0 ∼10 μA. We have made magnetometers with white noise levels down to 55 fT Hz -1/2 and a 1/f knee at 1 Hz (ac biased). Noise measurements were made on a field-cooled magnetometer. The noise measured at 1 Hz when cooled in 'zero field' was 175 fT Hz -1/2 . When cooled in magnetic fields of B = 50 μT and B = 100 μT we measured the noise at 1 Hz to be 430 fT Hz -1 2 and 1.3 pT Hz -1/2 , respectively. (author)

  2. Silent Localization of Underwater Sensors Using Magnetometers

    Directory of Open Access Journals (Sweden)

    Jonas Callmer

    2010-01-01

    Full Text Available Sensor localization is a central problem for sensor networks. If the sensor positions are uncertain, the target tracking ability of the sensor network is reduced. Sensor localization in underwater environments is traditionally addressed using acoustic range measurements involving known anchor or surface nodes. We explore the usage of triaxial magnetometers and a friendly vessel with known magnetic dipole to silently localize the sensors. The ferromagnetic field created by the dipole is measured by the magnetometers and is used to localize the sensors. The trajectory of the vessel and the sensor positions are estimated simultaneously using an Extended Kalman Filter (EKF. Simulations show that the sensors can be accurately positioned using magnetometers.

  3. Man-Portable Simultaneous Magnetometer and EM System (MSEMS)

    Science.gov (United States)

    2008-12-01

    limited to cesium vapor magnetometers outputting a Larmor signal. It cannot, as presently configured, be used with less expensive fluxgate magnetometers ...pulses to convert the frequency-based Larmor signal into nT. A fluxgate magnetometer does not employ the resonance mechanism of an alkali vapor...Simultaneous Magnetometer and EM System (MSEMS) December 2008 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the

  4. Determination of the Overhauser magnetometer uncertainty

    Czech Academy of Sciences Publication Activity Database

    Ulvr, M.; Zikmund, A.; Kupec, J.; Janošek, M.; Vlk, Michal; Bayer, Tomáš

    2015-01-01

    Roč. 66, 7/s (2015), s. 26-29 ISSN 1335-3632 Institutional support: RVO:67985530 Keywords : Overhauser magnetometer * Earth `s magnetic field * comparison * uncertainty Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.407, year: 2015

  5. Development of autonomous magnetometer rotorcraft for wide area assessment

    Energy Technology Data Exchange (ETDEWEB)

    Roelof Versteeg; Matt Anderson; Les Beard; Eric Corban; Darryl Curley; Jeff Gamey; Ross Johnson; Dwight Junkin; Mark McKay; Jared Salzmann; Mikhail Tchernychev; Suraj Unnikrishnan; Scott Vinson

    2010-04-01

    Large areas across the United States are potentially contaminated with UXO, with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with 1) near 100 % coverage and 2) near 100 % detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area assessment is a multi-level one, in which medium - altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry. Subsequent to this wide area assessment targeted surface investigations are performed using either towed geophysical sensor arrays or man portable sensors. In order to be an effective tool for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 – 3 meters. These altitude requirements mean that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys (resulting in costs of approximately $100-$150/acre). In addition, due to the low altitude there are substantial risks to pilots and equipment. Surface towed arrays provide high resolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. There is thus a need for other systems which can be used for effective data collection. An UAV (Unmanned Aerial Vehicle) magnetometer platform is an obvious alternative. The motivation behind such a system is that it reduces risk to operators, is lower in initial and Operational and Maintenance (O&M) costs (and can thus potentially be applied to smaller sites) and has the potential of being more effective in terms of detection and possibly characterization (through the use of

  6. A survey of high explosive-induced damage and spall in selected metals using proton radiography

    International Nuclear Information System (INIS)

    Holtkamp, D.B.; Clark, D.A.; Ferm, E.N.; Gallegos, R.A.; Hammon, D.; Hemsing, W.F.; Hogan, G.E.; Holmes, V.H.; King, N.S.P.; Lopez, R.P.; Merrill, F.E.; Morris, C.L.; Morley, K.B.; Murray, M.M.; Pazuchanics, P.D.; Prestridge, K.P.; Quintana, J.P.; Saunders, A.; Shinas, M.A.; Stacy, H.L.

    2004-01-01

    Multiple spall and damage layers can be created in metal when the free surface reflects a Taylor wave generated by high explosives. These phenomena have been explored in different thicknesses of several metals (tantalum, copper, 6061 T6-aluminum, and tin) using high-energy proton radiography. Multiple images (up to 21) can be produced of the dynamic evolution of damaged material on the microsecond time scale with a <50 ns 'shutter' time. Movies and multiframe still images of areal and (Abel inverted) volume densities are presented. An example of material that is likely melted on release (tin) is also presented

  7. A Web Server for MACCS Magnetometer Data

    Science.gov (United States)

    Engebretson, Mark J.

    1998-01-01

    NASA Grant NAG5-3719 was provided to Augsburg College to support the development of a web server for the Magnetometer Array for Cusp and Cleft Studies (MACCS), a two-dimensional array of fluxgate magnetometers located at cusp latitudes in Arctic Canada. MACCS was developed as part of the National Science Foundation's GEM (Geospace Environment Modeling) Program, which was designed in part to complement NASA's Global Geospace Science programs during the decade of the 1990s. This report describes the successful use of these grant funds to support a working web page that provides both daily plots and file access to any user accessing the worldwide web. The MACCS home page can be accessed at http://space.augsburg.edu/space/MaccsHome.html.

  8. Midlatitude magnetometer chains during the IMS

    International Nuclear Information System (INIS)

    Mcpherron, R.L.

    1982-01-01

    The International Magnetospheric Study (IMS) is an international program to study global problems of magnetospheric dynamics. A key element of the U.S. participation in this program was the establishment of a ground magnetometer network. This network included a number of arrays at high and low latitudes. This report describes three chains established at midlatitudes, including the IMS Midlatitude Chain, the AFGL Magnetometer Network, and the Bell Lab Conjugate Array. Descriptions of the type of equipment, station locations, types of data display, and availability of data for each chain are presented in this report. A major problem of the data analysis phase of the IMS will be reducing selected subsets of these data to a common format. Currently, there are no plans to do this in a systematic manner

  9. Digital Detection and feedback Fluxgate Magnetometer

    DEFF Research Database (Denmark)

    Piil-Henriksen, J.; Merayo, José M.G.; Nielsen, Otto V

    1996-01-01

    A new full Earth's field dynamic feedback fluxgate magnetometer is described. It is based entirely on digital signal processing and digital feedback control, thereby replacing the classical second harmonic tuned analogue electronics by processor algorithms. Discrete mathematical cross......-correlation routines and substantial oversampling reduce the noise to 71 pT root-mean-square in a 0.25-10 Hz bandwidth for a full Earth's field range instrument....

  10. High temperature superconductive flux gate magnetometer

    International Nuclear Information System (INIS)

    Gershenson, M.

    1991-01-01

    This paper proposes a different type of HTS superconducting magnetometer based on the non-linear magnetic behavior of bulk HTS materials. The device design is based on the generation of second harmonics which arise as a result of non-linear magnetization observed in Type-II superconductors. Even harmonics are generated from the non-linear interaction of an ac excitation signal with an external DC magnetic field which acts as a bias signal

  11. Mathematical model of a fluxgate magnetometer

    OpenAIRE

    Baranov Pavel F.; Baranova Vitalia E.; Nesterenko Tamara G.

    2018-01-01

    In paper analytical equations for calculate the electromotive force in the measuring coil of the fluxgate magnetometer independent of the drive signal frequency content are presented. Also, the equations for es-timation of the fluxgate sensitivity at any harmonic and for study fluxgates operation with a glance to the waveform and the polynomial approximation of the mean magnetization curve of the core are provided.

  12. Mathematical model of a fluxgate magnetometer

    Directory of Open Access Journals (Sweden)

    Baranov Pavel F.

    2018-01-01

    Full Text Available In paper analytical equations for calculate the electromotive force in the measuring coil of the fluxgate magnetometer independent of the drive signal frequency content are presented. Also, the equations for es-timation of the fluxgate sensitivity at any harmonic and for study fluxgates operation with a glance to the waveform and the polynomial approximation of the mean magnetization curve of the core are provided.

  13. Fluxgate magnetometers for outer planets exploration

    Science.gov (United States)

    Acuna, M. H.

    1974-01-01

    The exploration of the interplanetary medium and the magnetospheres of the outer planets requires the implementation of magnetic field measuring instrumentation with wide dynamic range, high stability, and reliability. The fluxgate magnetometers developed for the Pioneer 11 and Mariner-Jupiter-Saturn missions are presented. These instruments cover the range of .01 nT to 2 million nT with optimum performance characteristics and low power consumption.

  14. The MAGSAT vector magnetometer: A precision fluxgate magnetometer for the measurement of the geomagnetic field

    Science.gov (United States)

    Acuna, M. H.; Scearce, C. S.; Seek, J.; Scheifele, J.

    1978-01-01

    A description of the precision triaxial fluxgate magnetometer to be flown aboard the MAGSAT spacecraft is presented. The instrument covers the range of + or - 64,000 nT with a resolution of + or - 0.5 nT, an intrinsic accuracy of + or - 0.001% of full scale and an angular alignment stability of the order of 2 seconds of arc. It was developed at NASA's Goddard Space Flight Center and represents the state-of-the-art in precision vector magnetometers developed for spaceflight use.

  15. Development of a Micro-Fabricated Total-Field Magnetometer

    Science.gov (United States)

    2011-03-01

    are made with fluxgate technologies. Fluxgates have lower sensitivity than Cs magnetometers , yet they continue to be used in small wands simply...extraction process by providing the sensitivity of a Cs magnetometer with the convenience and low cost of a fluxgate wand. Extremely small and low cost...FINAL REPORT Development of a Micro-Fabricated Total-Field Magnetometer SERDP Project MR-1512 MARCH 2011 Mark Prouty Geometrics, Inc

  16. Choice of optimal parameters for the superconductive quantum magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, B V; Ivanenko, A I; Trofimov, V N

    1974-12-31

    The problem of choosing the optimal coupling coefficient and optimal working frequency for superconductive quantum magnetometer is considered. The present experimental signalnoise dependence confirms the drawn conclusions. (auth)

  17. High Tc Josephson Junctions, SQUIDs and magnetometers

    International Nuclear Information System (INIS)

    Clarke, J.

    1991-01-01

    There has recently been considerable progress in the state-of-the-art of high-T c magnetometers based on dc SQUIDs (Superconducting Quantum Interference Devices). This progress is due partly to the development of more manufacturable Josephson junctions, making SQUIDs easier to fabricate, and partly to the development of multiturn flux transformers that convert the high sensitivity of SQUIDs to magnetic flux to a correspondingly high sensitivity to magnetic field. Needless to say, today's high-T c SQUIDs are still considerably less sensitive than their low-T c counterparts, particularly at low frequencies (f) where their level of 1/f noise remains high. Nonetheless, the performance of the high-T c devices has now reached the point where they are adequate for a number of the less demanding applications; furthermore, as we shall see, at least modest improvements in performance are expected in the near future. In this article, the author outlines these various developments. This is far from a comprehensive review of the field, however, and, apart from Sec. 2, he describes largely his own work. He begins in Sec. 2 with an overview of the various types of Josephson junctions that have been investigated, and in Sec. 3, he describes some of the SQUIDs that have been tested, and assess their performance. Section 4 discuss the development of the multilayer structures essential for an interconnect technology, and, in particular, for crossovers and vias. Section 5 shows how this technology enables one to fabricate multiturn flux transformers which, in turn, can be coupled to SQUIDs to make magnetometers. The performance and possible future improvements in these magnetometers are assessed, and some applications mentioned

  18. Corrosion measurement using flux gate magnetometer

    International Nuclear Information System (INIS)

    Rashdi Shah Ahmad; Chong Cheong Wei

    2001-01-01

    The ability of fluxgate magnetometer to detect and measure quantitatively the magnetic field generated by electrochemical corrosion is presented. In this study, each sample (iron plate) was exposed to a range of increasingly corrosive environment. During the exposure, we measured the magnetic field above the sample for specific duration of time. The result shows that there is a clear relationship between corrosivity of the environment and the change in magnitude of magnetic field that was generated by the corrosion reaction. Therefore, the measurement of magnetic field might be used to determine the corrosion rates. (Author)

  19. Automated system for the calibration of magnetometers

    DEFF Research Database (Denmark)

    Petrucha, Vojtech; Kaspar, Petr; Ripka, Pavel

    2009-01-01

    A completely nonmagnetic calibration platform has been developed and constructed at DTU Space (Technical University of Denmark). It is intended for on-site scalar calibration of high-precise fluxgate magnetometers. An enhanced version of the same platform is being built at the Czech Technical Uni...... through custom-made optical incremental sensors. The system is controlled by a microcontroller, which executes commands from a computer. The properties of the system as well as calibration and measurement results will be presented. ©2009 American Institute of Physics...

  20. Performances and place of magnetometers based on amorphous wires compared to conventional magnetometers

    International Nuclear Information System (INIS)

    Robbes, D.; Dolabdjian, C.; Monfort, Y.

    2002-01-01

    We discuss and compare performances of various room temperature magnetometers. The work is directed towards the search of those magnetometers having a high sensitivity (>1000 V/T), a very low noise level (>1 pT/√Hz at white noise) attainable in a volume typically smaller than 1 cm 3 . The choice of this set of parameters is related to the useful comparison of room temperature magnetometers versus cryogenic ones, such as Superconducting Quantum Interferometer Devices (SQUIDs). The latter have highly degraded performances when their working operations needs an open unshielded environment as required for example in industrial application (non-destructive evaluation). SQUIDs have also a rather poor spatial resolution, and could be replaced by room temperature sensors in some magnetic imaging systems, which require a high spatial resolution. The paper is 'highlighted' in the field of magnetic sensors based on amorphous magnetic wires that were used to carry out wide bandwidth (>100 kHz), very low noise flux gate (∼pT/√Hz at white noise) and highly sensitive, low noise magnetometers (∼pT/√Hz at white noise) Colpitts oscillator configuration use by K. Bushida's

  1. Survey of findings in patients having persistent heartburn on proton pump inhibitor therapy.

    Science.gov (United States)

    Mandaliya, R; DiMarino, A J; Cohen, S

    2016-01-01

    In patients with refractory heartburn while on proton pump inhibitor (PPI) therapy, changing drugs or increasing treatment to a twice a day (b.i.d.) dose has become a common practice. This study aims to study patients with persistent heartburn while on PPI therapy and to determine if persistent symptom indicates the need for more aggressive or different therapy. A retrospective review of impedance-pH tracings on PPI therapy (q.d. or b.i.d.) for patients with persistent heartburn was performed. DeMeester score, impedance, and symptom sensitive index (SSI) were used as indices. Statistical analyses were performed using chi-squared test with Yates correction and paired t-test. One hundred consecutive patients, (female 50%, male 50%, mean age 54 [range 16-83] years) were studied on q.d. (n = 45) or b.i.d. PPI (n = 55). Only 20% of the patients had abnormal DeMeester score; 41% had an abnormal impedance score and 56% had abnormal SSI; 29% had all indices normal. There was no difference between patients taking q.d. versus b.i.d. PPI for abnormal DeMeester score (22 vs. 18%), impedance (38 vs. 44%) and SSI (53 vs. 58%); P = 0.80, 0.69, and 0.77, respectively. In 56 patients with positive SSI, symptoms were due to acid reflux in 8 (14%) patients, nonacid reflux in 31 (55%) patients, and combined acid and nonacid reflux in 17 (30%) patients. Patients with persistent heartburn on PPI therapy show a variety of disorders: (i) acid reflux (20%); (ii) nonacid reflux (26%); (iii) positive SSI (56%); (iv) all normal indices (29%). These studies indicate that persistent heartburn on PPI therapy is a complex problem that may not respond to simply increasing acid inhibition. © 2014 International Society for Diseases of the Esophagus.

  2. Diurnal and Seasonal Variations in Mid-Latitude Geomagnetic Field During International Quiet Days: BOH Magnetometer

    Directory of Open Access Journals (Sweden)

    Junga Hwang

    2012-12-01

    Full Text Available Korea Astronomy and Space Science Institute researchers have installed and operated magnetometers at Bohyunsan Observatory to measure the Earth's magnetic field variations in South Korea. In 2007, we installed a fluxgate magnetometer (RFP-523C to measure H, D, and Z components of the geomagnetic field. In addition, in 2009, we installed a Overhauser proton sensor to measure the absolute total magnetic field F and a three-axis magneto-impedance sensor for spectrum analysis. Currently three types of magnetometer data have been accumulated. In this paper, we use the H, D, Z components of fluxgate magnetometer data to investigate the characteristics of mid-latitude geomagnetic field variation. To remove the temporary changes in Earth’s geomagnetic filed by space weather, we use the international quiet days’ data only. In other words, we performed a superposed epoch analysis using five days per each month during 2008-2011. We find that daily variations of H, D, and Z shows similar tendency compared to previous results using all days. That is, H, D, Z all three components’ quiet intervals terminate near the sunrise and shows maximum 2-3 hours after the culmination and the quiet interval start from near the sunset. Seasonal variations show similar dependences to the Sun. As it becomes hot season, the geomagnetic field variation’s amplitude becomes large and the quiet interval becomes shortened. It is well-known that these variations are effects of Sq current system in the Earth’s atmosphere. We confirm that the typical mid-latitude geomagnetic field variations due to the Sq current system by excluding all possible association with the space weather.

  3. Mid-latitude Geomagnetic Field Analysis Using BOH Magnetometer: Preliminary Results

    Directory of Open Access Journals (Sweden)

    Junga Hwang

    2011-09-01

    Full Text Available Korea Astronomy and Space Science Institute researchers have installed and operated magnetometers at Mt. Bohyun Observatory to measure the Earth's magnetic field variations in South Korea. We, in 2007, installed a fluxgate magnetometer (RFP-523C to measure H, D, and Z components of the geomagnetic field. In addition, in 2009, we installed a Overhauser proton sensor to measure the absolute total magnetic field F and a three-axis magneto-impedance sensor for spectrum analysis. Currently three types of magnetometer data have been accumulated. In this paper, we provide the preliminary and the first statistical analysis using the BOH magnetometer installed at Mt. Bohyun Observatory. By superposed analysis, we find that daily variations of H, D, and Z shows similar tendency, that is, about 30 minutes before the meridian (11:28 a minimum appears and the time after about 3 hours and 30 minutes (15:28 a maximum appears. Also, a quiet interval start time (19:06 is near the sunset time, and a quiet interval end time (06:40 is near the sunrise time. From the sunset to the sunrise, the value of H has a nearly constant interval, that is, the sun affects the changes in H values. Seasonal variations show similar dependences to the sun. Local time variations show that noon region has the biggest variations and midnight region has the smallest variations. We compare the correlations between geomagnetic variations and activity indices as we expect the geomagnetic variation would contain the effects of geomagnetic activity variations. As a result, the correlation coefficient between H and Dst is the highest (r = 0.947, and other AL, AE, AU index and showed a high correlation. Therefore, the effects of geomagnetic storms and geomagnetic substorms might contribute to the geomagnetic changes significantly.

  4. Digital Fluxgate Magnetometer for Detection of Microvibration

    Directory of Open Access Journals (Sweden)

    Menghui Zhi

    2017-01-01

    Full Text Available In engineering practice, instruments, such as accelerometer and laser interferometer, are widely used in vibration measurement of structural parts. A method for using a triaxial fluxgate magnetometer as a microvibration sensor to measure low-frequency pendulum microvibration (not translational vibration is proposed in this paper, so as to detect vibration from low-frequency vibration sources, such as large rotating machine, large engineering structure, earthquake, and microtremor. This method provides vibration detection based on the environmental magnetic field signal to avoid increased measurement difficulty and error due to different relative positions of permanent magnet and magnetometer on the device under test (DUT when using the original magnetic measurement method. After fixedly connecting the fluxgate probe with the DUT during the test, the angular displacement due to vibration can be deduced by measuring the geomagnetic field’s magnetic induction intensity change on the orthogonal three components during the vibration. The test shows that the microvibration sensor has angular resolution of over 0.05° and maximum measuring frequency of 64 Hz. As an exploring test aimed to detect the microvibration of earth-orbiting satellite in the in-orbit process, the simulation experiment successfully provides the real-time microvibration information for attitude and orbit control subsystem.

  5. Automated system for the calibration of magnetometers

    International Nuclear Information System (INIS)

    Petrucha, Vojtech; Kaspar, Petr; Ripka, Pavel; Merayo, Jose M. G.

    2009-01-01

    A completely nonmagnetic calibration platform has been developed and constructed at DTU Space (Technical University of Denmark). It is intended for on-site scalar calibration of high-precise fluxgate magnetometers. An enhanced version of the same platform is being built at the Czech Technical University. There are three axes of rotation in this design (compared to two axes in the previous version). The addition of the third axis allows us to calibrate more complex devices. An electronic compass based on a vector fluxgate magnetometer and micro electro mechanical systems (MEMS) accelerometer is one example. The new platform can also be used to evaluate the parameters of the compass in all possible variations in azimuth, pitch, and roll. The system is based on piezoelectric motors, which are placed on a platform made of aluminum, brass, plastic, and glass. Position sensing is accomplished through custom-made optical incremental sensors. The system is controlled by a microcontroller, which executes commands from a computer. The properties of the system as well as calibration and measurement results will be presented

  6. Magnetoresistive magnetometer for space science applications

    International Nuclear Information System (INIS)

    Brown, P; Beek, T; Carr, C; O’Brien, H; Cupido, E; Oddy, T; Horbury, T S

    2012-01-01

    Measurement of the in situ dc magnetic field on space science missions is most commonly achieved using instruments based on fluxgate sensors. Fluxgates are robust, reliable and have considerable space heritage; however, their mass and volume are not optimized for deployment on nano or picosats. We describe a new magnetometer design demonstrating science measurement capability featuring significantly lower mass, volume and to a lesser extent power than a typical fluxgate. The instrument employs a sensor based on anisotropic magnetoresistance (AMR) achieving a noise floor of less than 50 pT Hz −1/2 above 1 Hz on a 5 V bridge bias. The instrument range is scalable up to ±50 000 nT and the three-axis sensor mass and volume are less than 10 g and 10 cm 3 , respectively. The ability to switch the polarization of the sensor's easy axis and apply magnetic feedback is used to build a driven first harmonic closed loop system featuring improved linearity, gain stability and compensation of the sensor offset. A number of potential geospace applications based on the initial instrument results are discussed including attitude control systems and scientific measurement of waves and structures in the terrestrial magnetosphere. A flight version of the AMR magnetometer will fly on the TRIO-CINEMA mission due to be launched in 2012. (paper)

  7. Battlefield Applications for the Polatomic 2000 Magnetometer/Gradiometer

    National Research Council Canada - National Science Library

    Kuhlman, G

    2002-01-01

    ... He(4) scalar magnetometer/gradiometer. A major innovation in the P-2000 helium magnetometer is the introduction of a laser pump source to replace the conventional RF discharge helium lamp used in the Navy AN/ASQ-81/208 MAD Set...

  8. Choice of Magnetometers and Gradiometers after Signal Space Separation.

    Science.gov (United States)

    Garcés, Pilar; López-Sanz, David; Maestú, Fernando; Pereda, Ernesto

    2017-12-16

    Modern Elekta Neuromag MEG devices include 102 sensor triplets containing one magnetometer and two planar gradiometers. The first processing step is often a signal space separation (SSS), which provides a powerful noise reduction. A question commonly raised by researchers and reviewers relates to which data should be employed in analyses: (1) magnetometers only, (2) gradiometers only, (3) magnetometers and gradiometers together. The MEG community is currently divided with regard to the proper answer. First, we provide theoretical evidence that both gradiometers and magnetometers result from the backprojection of the same SSS components. Then, we compare resting state and task-related sensor and source estimations from magnetometers and gradiometers in real MEG recordings before and after SSS. SSS introduced a strong increase in the similarity between source time series derived from magnetometers and gradiometers (r² = 0.3-0.8 before SSS and r² > 0.80 after SSS). After SSS, resting state power spectrum and functional connectivity, as well as visual evoked responses, derived from both magnetometers and gradiometers were highly similar (Intraclass Correlation Coefficient > 0.8, r² > 0.8). After SSS, magnetometer and gradiometer data are estimated from a single set of SSS components (usually ≤ 80). Equivalent results can be obtained with both sensor types in typical MEG experiments.

  9. Digital fluxgate magnetometer for the "Astrid-2" satellite

    DEFF Research Database (Denmark)

    Pedersen, Erik Bøje; Primdahl, Fritz; Petersen, Jan Raagaard

    1999-01-01

    The design and performance of the Astrid-2 magnetometer are described. The magnetometer uses mathematical routines implemented by software for commercially available digital dignal processors to determine the magnetic field from the fluxgate sensor. The sensor is from the latest generation of amo...

  10. Analysing Harmonic Motions with an iPhone's Magnetometer

    Science.gov (United States)

    Yavuz, Ahmet; Temiz, Burak Kagan

    2016-01-01

    In this paper, we propose an experiment for analysing harmonic motion using an iPhone's (or iPad's) magnetometer. This experiment consists of the detection of magnetic field variations obtained from an iPhone's magnetometer sensor. A graph of harmonic motion is directly displayed on the iPhone's screen using the "Sensor Kinetics"…

  11. Proton-proton bremsstrahlung

    International Nuclear Information System (INIS)

    Fearing, H.W.

    1990-01-01

    We summarize some of the information about the nucleon-nucleon force which has been obtained by comparing recent calculations of proton-proton bremsstrahlung with cross section and analyzing power data from the new TRIUMF bremsstrahlung experiment. Some comments are made as to how these results can be extended to neutron-proton bremsstrahlung. (Author) 17 refs., 6 figs

  12. Development of Geomagnetic Monitoring System Using a Magnetometer for the Field

    Science.gov (United States)

    Lee, Young-Cheol; Kim, Sung-Wook; Choi, Eun-Kyeong; Kim, In-Soo

    2014-05-01

    Three institutes including KMA (Korea Meteorological Administration), KSWC (Korean Space Weather Center) of NRRA (National Radio Research Agency) and KIGAM (Korea Institute of Geoscience and Mineral Resources) are now operating magnetic observatories. Those observatories observe the total intensity and three components of geomagnetic element. This paper comes up with a magnetic monitoring system now under development that uses a magnetometer for field survey. In monitoring magnetic variations in areas (active faults or volcanic regions), more reliable results can be obtained when an array of several magnetometers are used rather than a single magnetometer. In order to establish and operate a magnetometer array, such factors as expenses, convenience of the establishment and operation of the array should be taken into account. This study has come up with a magnetic monitoring system complete with a magnetometer for the field survey of our own designing. A magnetic monitoring system, which is composed of two parts. The one is a field part and the other a data part. The field part is composed of a magnetometer, an external memory module, a power supply and a set of data transmission equipment. The data part is a data server which can store the data transmitted from the field part, analyze the data and provide service to the web. This study has developed an external memory module for ENVI-MAG (Scintrex Ltd.) using an embedded Cortex-M3 board, which can be programmed, attach other functional devices (SD memory cards, GPS antennas for time synchronization, ethernet cards and so forth). The board thus developed can store magnetic measurements up to 8 Gbytes, synchronize with the GPS time and transmit the magnetic measurements to the data server which is now under development. A monitoring system of our own developing was installed in Jeju island, taking measurements throughout Korea. Other parts including a data transfer module, a server and a power supply using solar

  13. Hall probe magnetometer for SSC magnet cables

    International Nuclear Information System (INIS)

    Cross, R.W.; Goldfarb, R.B.

    1991-01-01

    The authors of this paper constructed a Hall probe magnetometer to measure the magnetization hysteresis loops of Superconducting Super Collider magnet cables. The instrument uses two Hall-effect field sensors to measure the applied field H and the magnetic induction B. Magnetization M is calculated from the difference of the two quantities. The Hall probes are centered coaxially in the bore of a superconducting solenoid with the B probe against the sample's broad surface. An alternative probe arrangement, in which M is measured directly, aligns the sample probe parallel to the field. The authors measured M as a function of H and field cycle rate both with and without a dc transport current. Flux creep as a function of current was measured from the dependence of ac loss on the cycling rate and from the decay of magnetization with time. Transport currents up to 20% of the critical current have minimal effect on magnetization and flux creep

  14. Quantum critical environment assisted quantum magnetometer

    Science.gov (United States)

    Jaseem, Noufal; Omkar, S.; Shaji, Anil

    2018-04-01

    A central qubit coupled to an Ising ring of N qubits, operating close to a critical point is investigated as a potential precision quantum magnetometer for estimating an applied transverse magnetic field. We compute the quantum Fisher information for the central, probe qubit with the Ising chain initialized in its ground state or in a thermal state. The non-unitary evolution of the central qubit due to its interaction with the surrounding Ising ring enhances the accuracy of the magnetic field measurement. Near the critical point of the ring, Heisenberg-like scaling of the precision in estimating the magnetic field is obtained when the ring is initialized in its ground state. However, for finite temperatures, the Heisenberg scaling is limited to lower ranges of N values.

  15. Development of Autonomous Magnetometer Rotorcraft For Wide Area Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mark D. McKay; Matthew O. Anderson

    2011-08-01

    Large areas across the United States and internationally are potentially contaminated with unexploded ordinance (UXO), with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with (1) near 100% coverage and (2) near 100% detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area assessment is a multi-level one, in which medium - altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry. Subsequent to this wide area assessment targeted surface investigations are performed using either towed geophysical sensor arrays or man portable sensors. In order to be an effective tool for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 to 3 meters. These altitude requirements mean that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys, resulting in costs of approximately $100-$150/acre. In addition, due to the low altitude there are substantial risks to pilots and equipment. Surface towed arrays provide highresolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. Thus there is a need for other systems, which can be used for effective data collection. An Unmanned Aerial Vehicle (UAV) magnetometer platform is an obvious alternative. The motivation behind such a system is that it reduces risk to operators, is lower in initial and Operational and Maintenance (O&M) costs (and can thus potentially be applied to smaller sites) and has the potential of being more effective in terms of detection and possibly

  16. High transition-temperature SQUID magnetometers and practical applications

    International Nuclear Information System (INIS)

    Dantsker, E.; Lawrence Berkeley National Lab., CA

    1997-05-01

    The design, fabrication and performance of SQUID magnetometers based on thin films of the high-transition temperature superconductor YBa 2 Cu 3 O 7-x (YBCO) are described. Essential to the achieving high magnetic field resolution at low frequencies is the elimination of 1/f flux noise due to thermally activated hopping of flux vortices between pinning sites in the superconducting films. Through improvements in processing, 1/f noise in single layer YBCO thin films and YBCO-SrTiO 3 -YBCO trilayers was systematically reduced to allow fabrication of sensitive SQUID magnetometers. Both single-layer directly coupled SQUID magnetometers and multilayer magnetometers were fabricated, based on the dc SQUID with bicrystal grain boundary Josephson junctions. Multilayer magnetometers had a lower magnetic field noise for a given physical size due to greater effective sensing areas. A magnetometer consisting of a SQUID inductively coupled to the multiturn input coil of a flux transformer in a flip-chip arrangement had a field noise of 27 fT Hz -1/2 at 1 Hz and 8.5 fT Hz -1/2 at 1 kHz. A multiloop multilayer SQUID magnetometer had a field noise of 37 fT Hz -1/2 at 1 Hz and 18 fT Hz -1/2 at 1 kHz. A three-axis SQUID magnetometer for geophysical applications was constructed and operated in the field in the presence of 60 Hz and radiofrequency noise. Clinical quality magnetocardiograms were measured using multilayer SQUID magnetometers in a magnetically shielded room

  17. High transition-temperature SQUID magnetometers and practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Dantsker, Eugene [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1997-05-01

    The design, fabrication and performance of SQUID magnetometers based on thin films of the high-transition temperature superconductor YBa2Cu3O7-x (YBCO) are described. Essential to the achieving high magnetic field resolution at low frequencies is the elimination of 1/f flux noise due to thermally activated hopping of flux vortices between pinning sites in the superconducting films. Through improvements in processing, 1/f noise in single layer YBCO thin films and YBCO-SrTiO3-YBCO trilayers was systematically reduced to allow fabrication of sensitive SQUID magnetometers. Both single-layer directly coupled SQUID magnetometers and multilayer magnetometers were fabricated, based on the dc SQUID with bicrystal grain boundary Josephson junctions. Multilayer magnetometers had a lower magnetic field noise for a given physical size due to greater effective sensing areas. A magnetometer consisting of a SQUID inductively coupled to the multiturn input coil of a flux transformer in a flip-chip arrangement had a field noise of 27 fT Hz-1/2 at 1 Hz and 8.5 fT Hz-1/2 at 1 kHz. A multiloop multilayer SQUID magnetometer had a field noise of 37 fT Hz-1/2 at 1 Hz and 18 fT Hz-1/2 at 1 kHz. A three-axis SQUID magnetometer for geophysical applications was constructed and operated in the field in the presence of 60 Hz and radiofrequency noise. Clinical quality magnetocardiograms were measured using multilayer SQUID magnetometers in a magnetically shielded room.

  18. Search Coil vs. Fluxgate Magnetometer Measurements at Interplanetary Shocks

    Science.gov (United States)

    Wilson, L.B., III

    2012-01-01

    We present magnetic field observations at interplanetary shocks comparing two different sample rates showing significantly different results. Fluxgate magnetometer measurements show relatively laminar supercritical shock transitions at roughly 11 samples/s. Search coil magnetometer measurements at 1875 samples/s, however, show large amplitude (dB/B as large as 2) fluctuations that are not resolved by the fluxgate magnetometer. We show that these fluctuations, identified as whistler mode waves, would produce a significant perturbation to the shock transition region changing the interpretation from laminar to turbulent. Thus, previous observations of supercritical interplanetary shocks classified as laminar may have been under sampled.

  19. Self-Compensating Excitation of Fluxgate Sensors for Space Magnetometers

    DEFF Research Database (Denmark)

    Cerman, Alec; Merayo, José M.G.; Brauer, Peter

    2008-01-01

    The paper presents design and implementation of the new self-compensating excitation circuitry to the new generation of high-precise space vector magnetometers. The application starts with complex study including design of new robust model of the non-linear inductor leading to investigation...... of the most crucial points, continuous by design of the self-compensating excitation unit and concludes with unit complex testing and application to the magnetometer. The application of the self-compensation of the excitation decreases temperature drift of the magnetometer offset caused by the temperature...

  20. Analysing harmonic motions with an iPhone’s magnetometer

    Science.gov (United States)

    Yavuz, Ahmet; Kağan Temiz, Burak

    2016-05-01

    In this paper, we propose an experiment for analysing harmonic motion using an iPhone’s (or iPad’s) magnetometer. This experiment consists of the detection of magnetic field variations obtained from an iPhone’s magnetometer sensor. A graph of harmonic motion is directly displayed on the iPhone’s screen using the Sensor Kinetics application. Data from this application was analysed with Eureqa software to establish the equation of the harmonic motion. Analyses show that the use of an iPhone’s magnetometer to analyse harmonic motion is a practical and effective method for small oscillations and frequencies less than 15-20 Hz.

  1. GIOTTO MAGNETOMETER 8 SECOND DATA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of the Giotto Magnetometer Experiment is the investigation of the interaction between Comet Halley and the solar wind at a distance of 0.9 AU from...

  2. Developement of a Fluxgate Magnetometer for the KITSAT-3 Satellite

    Directory of Open Access Journals (Sweden)

    S. H. Hwang

    1997-12-01

    Full Text Available The magnetometer is one of the most important payloads of scientific satellites to monitor the near-earth space environment. The electromagnetic variations of the space environment can be observed with the electric and magnetic field measurements. In practice, it is well known that the measurement of magnetic fields needs less technical complexities than that of electric fields in space. Therefore the magnetometer has long been recognized as one of the basic payloads for the scientific satellites. In this paper, we discuss the scientific fluxgate magnetometer which will be on board the KITSAT-3. The main circuit design of the present magnetometer is based on that of KISAT-1 and -2 but its facilities have been re-designed to improve the resolution to about 5nT for scientific purpose. The calibration and noise level test of this circuit have been performed at the laboratory of the Tierra Tecnica company in Japan.

  3. Differential Search Coils Based Magnetometers: Conditioning, Magnetic Sensitivity, Spatial Resolution

    Directory of Open Access Journals (Sweden)

    Timofeeva Maria

    2012-03-01

    Full Text Available A theoretical and experimental comparison of optimized search coils based magnetometers, operating either in the Flux mode or in the classical Lenz-Faraday mode, is presented. The improvements provided by the Flux mode in terms of bandwidth and measuring range of the sensor are detailed. Theory, SPICE model and measurements are in good agreement. The spatial resolution of the sensor is studied which is an important parameter for applications in non destructive evaluation. A general expression of the magnetic sensitivity of search coils sensors is derived. Solutions are proposed to design magnetometers with reduced weight and volume without degrading the magnetic sensitivity. An original differential search coil based magnetometer, made of coupled coils, operating in flux mode and connected to a differential transimpedance amplifier is proposed. It is shown that this structure is better in terms of volume occupancy than magnetometers using two separated coils without any degradation in magnetic sensitivity. Experimental results are in good agreement with calculations.

  4. VOYAGER 1 SATURN MAGNETOMETER RESAMPLED DATA 9.60 SEC

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Voyager 1 Saturn encounter magnetometer data that have been resampled at a 9.6 second sample rate. The data set is composed of 6 columns: 1)...

  5. Self-Calibrating Vector Helium Magnetometer (SVHM), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR proposal describes proposed development of a conceptual design for a Self-Calibrating Vector Helium Magnetometer (SVHM) for design and fabrication...

  6. VOYAGER 2 JUPITER MAGNETOMETER RESAMPLED DATA 48.0 SEC

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Voyager 2 Jupiter encounter magnetometer data that have been resampled at a 48.0 second sample rate. The data set is composed of 6 columns: 1)...

  7. Ultrasensitive magnetometers based on rotational magnetic excitation

    International Nuclear Information System (INIS)

    Hristoforou, E.; Svec, P. Sr.

    2014-01-01

    Three new types of fluxgate magnetometers are presented in this paper, able to monitor the three components of the ambient field, all of them based on the principle of rotational excitation field. The first type is based on Yttrium- Iron Garnet (YIG) single crystal film, magnetized with rotational field on its plane, where the 2"n"d, 4"t"h and 6"t"h harmonics offer the three components of the ambient field with sensitivity better than 1 pT at 0.2 Hz, its size being 25 cm"3. The second type is based on permalloy film, where the rotational excitation field on its plane offers change of magnetoresistance with sensitivity better than 10 pT at 1 Hz, uncertainty of 1 ppm and size ∼ 8 cm"3. The third type, is based on amorphous film, where the rotation field mode offer sensitivity better than 100 pT at 1 Hz, uncertainty of 10 ppm and size ∼ 10 mm"3. (authors)

  8. The Search-Coil Magnetometer for MMS

    Science.gov (United States)

    Le Contel, O.; Leroy, P.; Roux, A.; Coillot, C.; Alison, D.; Bouabdellah, A.; Mirioni, L.; Meslier, L.; Galic, A.; Vassal, M. C.; Torbert, R. B.; Needell, J.; Rau, D.; Dors, I.; Ergun, R. E.; Westfall, J.; Summers, D.; Wallace, J.; Magnes, W.; Valavanoglou, A.; Olsson, G.; Chutter, M.; Macri, J.; Myers, S.; Turco, S.; Nolin, J.; Bodet, D.; Rowe, K.; Tanguy, M.; de la Porte, B.

    2016-03-01

    The tri-axial search-coil magnetometer (SCM) belongs to the FIELDS instrumentation suite on the Magnetospheric Multiscale (MMS) mission (Torbert et al. in Space Sci. Rev. (2014), this issue). It provides the three magnetic components of the waves from 1 Hz to 6 kHz in particular in the key regions of the Earth's magnetosphere namely the subsolar region and the magnetotail. Magnetospheric plasmas being collisionless, such a measurement is crucial as the electromagnetic waves are thought to provide a way to ensure the conversion from magnetic to thermal and kinetic energies allowing local or global reconfigurations of the Earth's magnetic field. The analog waveforms provided by the SCM are digitized and processed inside the digital signal processor (DSP), within the Central Electronics Box (CEB), together with the electric field data provided by the spin-plane double probe (SDP) and the axial double probe (ADP). On-board calibration signal provided by DSP allows the verification of the SCM transfer function once per orbit. Magnetic waveforms and on-board spectra computed by DSP are available at different time resolution depending on the selected mode. The SCM design is described in details as well as the different steps of the ground and in-flight calibrations.

  9. Ultra-sensitive Magnetic Microscopy with an Atomic Magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-19

    The PowerPoint presentation focused on research goals, specific information about the atomic magnetometer, response and resolution factors of the SERF magnetometer, FC+AM systems, tests of field transfer and resolution on FC, gradient cancellation, testing of AM performance, ideas for a multi-channel AM, including preliminary sensitivity testing, and a description of a 6 channel DAQ system. A few ideas for future work ended the presentation.

  10. Magnetometer and Gyroscope Calibration Method with Level Rotation

    Directory of Open Access Journals (Sweden)

    Zongkai Wu

    2018-03-01

    Full Text Available Micro electro mechanical system (MEMS gyroscopes and magnetometers are usually integrated into a sensor module or chip and widely used in a variety of applications. In existing integrated gyroscope and magnetometer calibration methods, rotation in all possible orientations is a necessary condition for a good calibration result. However, rotation around two or more axes is difficult to attain, as it is limited by the range of movement of vehicles such as cars, ships, or planes. To solve this problem, this paper proposes an integrated magnetometer and gyroscope calibration method with level rotation. The proposed method presents a redefined magnetometer output model using level attitude. New gyroscope and magnetometer calibration models are then deduced. In addition, a simplified cubature Kalman filter (CKF is established to estimate calibration parameters. This method possesses important value for application in actual systems, as it only needs level rotation for real-time calibration of gyroscopes and magnetometers. Theoretical analysis and test results verify the validity and feasibility of this method.

  11. Plasma Distribution in Mercury's Magnetosphere Derived from MESSENGER Magnetometer and Fast Imaging Plasma Spectrometer Observations

    Science.gov (United States)

    Korth, Haje; Anderson, Brian J.; Gershman, Daniel J.; Raines, Jim M.; Slavin, James A.; Zurbuchen, Thomas H.; Solomon, Sean C.; McNutt, Ralph L.

    2014-01-01

    We assess the statistical spatial distribution of plasma in Mercury's magnetosphere from observations of magnetic pressure deficits and plasma characteristics by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. The statistical distributions of proton flux and pressure were derived from 10months of Fast Imaging Plasma Spectrometer (FIPS) observations obtained during the orbital phase of the MESSENGER mission. The Magnetometer-derived pressure distributions compare favorably with those deduced from the FIPS observations at locations where depressions in the magnetic field associated with the presence of enhanced plasma pressures are discernible in the Magnetometer data. The magnitudes of the magnetic pressure deficit and the plasma pressure agree on average, although the two measures of plasma pressure may deviate for individual events by as much as a factor of approximately 3. The FIPS distributions provide better statistics in regions where the plasma is more tenuous and reveal an enhanced plasma population near the magnetopause flanks resulting from direct entry of magnetosheath plasma into the low-latitude boundary layer of the magnetosphere. The plasma observations also exhibit a pronounced north-south asymmetry on the nightside, with markedly lower fluxes at low altitudes in the northern hemisphere than at higher altitudes in the south on the same field line. This asymmetry is consistent with particle loss to the southern hemisphere surface during bounce motion in Mercury's offset dipole magnetic field.

  12. Fluxgate Magnetometer system mounted on UAS system: First field test at Dominga IOCG deposit, Chile

    Science.gov (United States)

    Yanez, G. A.; Banchero, L.; Marco, A.; Figueroa, R.

    2016-12-01

    With the support of Fundacion Chile (FCH) grant, we developed an airborne magnetic system (GeoMagDrone GFDAS) mounted on a UAS octodrone platform (DJI, S1000), based on a low cost/light-weight fluxgate magnetometer (FGM-301) and a robust/light-weight data logger for position, temperature, radar altimeter and 3 magnetic components at 16 Hz recording. Fluxgate magnetometer is hanging from the UAS platform at a distance of 2.5m where the EM noise is reduced to less than 2 nT. The whole geophysical system, including batteries, weights 650 gr., with an autonomy of 2 hours. Magnetometer calibration includes the 9 coefficients of amplitude, offset, and orthogonality, and temperature correction. We test the system over the IOCG deposit of Dominga-Chile, a magnetite ore (40%) (a block of 2x3 km with NS lines separated every 50m and a clearance of 40m, the mineral deposit buried 50-100m from the surface, where a ground magnetic survey was conducted previously. Ground conditions includes relatively rough topography with slopes of 10-20%, and some windy days. We use the digital terrain model SRTM30 to define the drape flight shape Average flight performance includes a mean speed of 35-40 km/hour, and an UAS battery consumption of 18-12 minutes depending on the wind conditions. A good correspondence was found between plan deployment and survey results in terms of line direction/separation/clearance. Line path were flown with errors less than 5 meters, whereas clearance of 40m was kept depending on the amount of control points used. The comparison between ground survey and GeoMagDrone results show a perfect match (anomaly amplitude/shape and noise envelope), validating in this way the system developed. Main concern for the productive application of this technology in unmanned geophysical platforms is the battery performance and the quality of digital terrain models to follow the topography.

  13. Design and implementation of JOM-3 Overhauser magnetometer analog circuit

    Science.gov (United States)

    Zhang, Xiao; Jiang, Xue; Zhao, Jianchang; Zhang, Shuang; Guo, Xin; Zhou, Tingting

    2017-09-01

    Overhauser magnetometer, a kind of static-magnetic measurement system based on the Overhauser effect, has been widely used in archaeological exploration, mineral resources exploration, oil and gas basin structure detection, prediction of engineering exploration environment, earthquakes and volcanic eruotions, object magnetic measurement and underground buried booty exploration. Overhauser magnetometer plays an important role in the application of magnetic field measurement for its characteristics of small size, low power consumption and high sensitivity. This paper researches the design and the application of the analog circuit of JOM-3 Overhauser magnetometer. First, the Larmor signal output by the probe is very weak. In order to obtain the signal with high signal to noise rstio(SNR), the design of pre-amplifier circuit is the key to improve the quality of the system signal. Second, in this paper, the effectual step which could improve the frequency characters of bandpass filter amplifier circuit were put forward, and theoretical analysis was made for it. Third, the shaping circuit shapes the amplified sine signal into a square wave signal which is suitable for detecting the rising edge. Fourth, this design elaborated the optimized choice of tuning circuit, so the measurement range of the magnetic field can be covered. Last, integrated analog circuit testing system was formed to detect waveform of each module. By calculating the standard deviation, the sensitivity of the improved Overhauser magnetometer is 0.047nT for Earth's magnetic field observation. Experimental results show that the new magnetometer is sensitive to earth field measurement.

  14. Feasibility Study for an Autonomous UAV -Magnetometer System -- Final Report on SERDP SEED 1509:2206

    Energy Technology Data Exchange (ETDEWEB)

    Roelof Versteeg; Mark McKay; Matt Anderson; Ross Johnson; Bob Selfridge; Jay Bennett

    2007-09-01

    Large areas across the United States are potentially contaminated with UXO, with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with 1) near 100 % coverage and 2) near 100 % detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area scanning is a multi-level one, in which medium altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry followed by surface investigations using either towed geophysical sensor arrays or man portable sensors. In order to be effective for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 – 3 meters. These altitude requirements means that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys (resulting in costs of approximately $100-$150/acre). Surface towed arrays provide high resolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. Thus, other systems are needed allowing for effective data collection. An UAV (Unmanned Aerial Vehicle) magnetometer platform is an obvious alternative. The motivation behind such a system is that it would be safer for the operators, cheaper in initial and O&M costs, and more effective in terms of site characterization. However, while UAV data acquisition from fixed wing platforms for large (> 200 feet) stand off distances is relatively straight forward, a host of challenges exist for low stand-off distance (~ 6 feet) UAV geophysical data acquisition. The objective of SERDP SEED 1509:2006 was to identify the primary challenges

  15. A survey of backward proton and pion production in p+C interactions at beam momenta from 1 to 400 GeV/c

    CERN Document Server

    Chvala, O.; Makariev, M.; Rybicki, A.; Varga, D.; Wenig, S.

    2013-01-01

    New data on proton and pion production in p+C interactions from the CERN PS and SPS accelerators are used in conjunction with other available data sets to perform a comprehensive survey of backward hadronic cross sections. This survey covers the complete backward hemisphere in the range of lab angles from 10 to 180 degrees, from 0.2 to 1.4 GeV/c in lab momentum and from 1 to 400 GeV/c in projectile momentum. Using the constraints of continuity and smoothness of the angular, momentum and energy dependences a consistent description of the inclusive cross sections is established which allows the control of the internal consistency of the nineteen available data sets.

  16. Calibration of the Ørsted vector magnetometer

    DEFF Research Database (Denmark)

    Olsen, Nils; Tøffner-Clausen, Lars; Sabaka, T.J.

    2003-01-01

    The vector fluxgate magnetometer of the Orsted satellite is routinely calibrated by comparing its output with measurements of the absolute magnetic intensity from the Overhauser instrument, which is the second magnetometer of the satellite. We describe the method used for and the result obtained...... coordinate system and the reference system of the star imager. This is done by comparing the magnetic and attitude measurements with a model of Earth's magnetic field. The Euler angles describing this rotation are determined in this way with an accuracy of better than 4 arcsec....

  17. Microfabricated optically pumped magnetometer arrays for biomedical imaging

    Science.gov (United States)

    Perry, A. R.; Sheng, D.; Krzyzewski, S. P.; Geller, S.; Knappe, S.

    2017-02-01

    Optically-pumped magnetometers have demonstrated magnetic field measurements as precise as the best superconducting quantum interference device magnetometers. Our group develops miniature alkali atom-based magnetic sensors using microfabrication technology. Our sensors do not require cryogenic cooling, and can be positioned very close to the sample, making these sensors an attractive option for development in the medical community. We will present our latest chip-scale optically-pumped gradiometer developed for array applications to image magnetic fields from the brain noninvasively. These developments should lead to improved spatial resolution, and potentially sensitive measurements in unshielded environments.

  18. Electromagnetic induction imaging with a radio-frequency atomic magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Deans, Cameron; Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk; Hussain, Sarah; Renzoni, Ferruccio [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2016-03-07

    We report on a compact, tunable, and scalable to large arrays imaging device, based on a radio-frequency optically pumped atomic magnetometer operating in magnetic induction tomography modality. Imaging of conductive objects is performed at room temperature, in an unshielded environment and without background subtraction. Conductivity maps of target objects exhibit not only excellent performance in terms of shape reconstruction but also demonstrate detection of sub-millimetric cracks and penetration of conductive barriers. The results presented here demonstrate the potential of a future generation of imaging instruments, which combine magnetic induction tomography and the unmatched performance of atomic magnetometers.

  19. Long-term vacuum tests of single-mode vertical cavity surface emitting laser diodes used for a scalar magnetometer

    Science.gov (United States)

    Hagen, C.; Ellmeier, M.; Piris, J.; Lammegger, R.; Jernej, I.; Magnes, W.; Murphy, E.; Pollinger, A.; Erd, C.; Baumjohann, W.

    2017-11-01

    Scalar magnetometers measure the magnitude of the magnetic field, while vector magnetometers (mostly fluxgate magnetometers) produce three-component outputs proportional to the magnitude and the direction of the magnetic field. While scalar magnetometers have a high accuracy, vector magnetometers suffer from parameter drifts and need to be calibrated during flight. In some cases, full science return can only be achieved by a combination of vector and scalar magnetometers.

  20. Evaluating Detection and Estimation Capabilities of Magnetometer-Based Vehicle Sensors

    Science.gov (United States)

    2012-05-01

    fluxgate magnetometers whose operating characteristics are well documented [1, 2]. Such magnetometers measure two perpendicular magnetic components of...of surveillance scenarios. As part of that work, this analysis focuses on UGS utilizing of two-axis fluxgate magnetometers . Two MOPs are 12 -60 -40 -20...Proceedings of the IEEE, 78(6):973–989, June 1990. [2] E. M. Billingsley and S. W. Billingsley. Fluxgate magnetometers . Proceedings of the IEEE, 5090(194

  1. The Pioneer 11 high-field fluxgate magnetometer

    Science.gov (United States)

    Acuna, M. H.; Ness, N. F.

    1973-01-01

    The High Field Fluxgate Magnetometer Experiment flow aboard the Pioneer 11 spacecraft to investigate Jupiter's magnetic field is described. The instrument extends the spacecraft's upper limit measurement capability by more than an order of magnitude to 17.3 gauss with minimum power and volume requirements.

  2. Small Fluxgate Magnetometers: Development and Future Trends in Spain

    Science.gov (United States)

    Ciudad, David; Díaz-Michelena, Marina; Pérez, Lucas; Aroca, Claudio

    2010-01-01

    In this paper, we give an overview of the research on fluxgate magnetometers carried out in Spain. In particular we focus in the development of the planar-type instruments. We summarize the fabrication processes and signal processing developments as well as their use in complex systems and space. PMID:22294904

  3. Observations of interplanetary dust by the Juno magnetometer investigation

    DEFF Research Database (Denmark)

    Benn, Mathias; Jørgensen, John Leif; Denver, Troelz

    2017-01-01

    One of the Juno magnetometer investigation's star cameras was configured to search for unidentified objects during Juno's transit en route to Jupiter. This camera detects and registers luminous objects to magnitude 8. Objects persisting in more than five consecutive images and moving with an appa...... on the distribution and motion of interplanetary (>μm sized) dust....

  4. Ionospheric travelling convection vortices observed by the Greenland magnetometer chain

    DEFF Research Database (Denmark)

    Kotsiaros, Stavros; Stolle, Claudia; Friis-Christensen, Eigil

    2013-01-01

    The Greenland magnetometer array continuously provides geomagnetic variometer data since the early eighties. With the polar cusp passing over it almost every day, the array is suitable to detect ionospheric traveling convection vortices (TCVs), which were rst detected by Friis-Christensen et al...

  5. Small fluxgate magnetometers: development and future trends in Spain.

    Science.gov (United States)

    Ciudad, David; Díaz-Michelena, Marina; Pérez, Lucas; Aroca, Claudio

    2010-01-01

    In this paper, we give an overview of the research on fluxgate magnetometers carried out in Spain. In particular we focus in the development of the planar-type instruments. We summarize the fabrication processes and signal processing developments as well as their use in complex systems and space.

  6. Small Fluxgate Magnetometers: Development and Future Trends in Spain

    OpenAIRE

    Lucas Pérez; Claudio Aroca; Marina Díaz-Michelena; David Ciudad

    2010-01-01

    In this paper, we give an overview of the research on fluxgate magnetometers carried out in Spain. In particular we focus in the development of the planar-type instruments. We summarize the fabrication processes and signal processing developments as well as their use in complex systems and space.

  7. Small Fluxgate Magnetometers: Development and Future Trends in Spain

    Directory of Open Access Journals (Sweden)

    Lucas Pérez

    2010-03-01

    Full Text Available In this paper, we give an overview of the research on fluxgate magnetometers carried out in Spain. In particular we focus in the development of the planar-type instruments. We summarize the fabrication processes and signal processing developments as well as their use in complex systems and space.

  8. Design of a Low-Cost 2-Axes Fluxgate Magnetometer for Small Satellite Applications

    Directory of Open Access Journals (Sweden)

    Su-Jeoung Kim

    2005-03-01

    Full Text Available This paper addresses the design and analysis results of a 2-axes magnetometer for attitude determination of small satellite. A low-cost and efficient 2-axes fluxgate magnetometer was selected as the most suitable attitude sensor for LEO microsatellites which require a low-to-medium level pointing accuracy. An optimization trade-off study has been performed for the development of 2-axes fluxgate magnetometer. All the relevant parameters such as permeability, demagnetization factor, coil diameter, core thickness, and number of coil turns were considered for the sizing of a small satellite magnetometer. The magnetometer which is designed, manufactured, and tested in-house as described in this paper satisfies linearity requirement for determining attitude position of small satellites. On the basis of magnetometer which is designed in Space System Research Lab. (SSRL, commercial magnetometer will be developed.

  9. Proton therapy

    International Nuclear Information System (INIS)

    Smith, Alfred R

    2006-01-01

    Proton therapy has become a subject of considerable interest in the radiation oncology community and it is expected that there will be a substantial growth in proton treatment facilities during the next decade. I was asked to write a historical review of proton therapy based on my personal experiences, which have all occurred in the United States, so therefore I have a somewhat parochial point of view. Space requirements did not permit me to mention all of the existing proton therapy facilities or the names of all of those who have contributed to proton therapy. (review)

  10. Results from the GSFC fluxgate magnetometer on Pioneer 11

    Science.gov (United States)

    Acuna, M. H.; Ness, N. F.

    1976-01-01

    A high-field triaxial fluxgate magnetometer was mounted on Pioneer 11 to measure the main magnetic field of Jupiter. It is found that this planetary magnetic field is more complex than that indicated by the results of the Pioneer 10 vector helium magnetometer. At distances less than 3 Jupiter radii, the magnetic field is observed to increase more rapidly than an inverse-cubed distance law associated with any simple dipole model. Contributions from higher-order multipoles are significant, with the quadrupole and octupole being 24 and 21 percent of the dipole moment, respectively. Implications of the results for the study of trapped particles, planetary radio emission, and planetary interiors are discussed. Major conclusions are that the deviation of the main planetary magnetic field from a simple dipole leads to distortion of the L shells of the charged particles and to warping of the magnetic equator. Enhanced absorption effects associated with Amalthea and Io are predicted.

  11. Fluxgate Magnetometer Array for Geomagnetic Abnormal Phenomena Tracking

    Directory of Open Access Journals (Sweden)

    Xiaomei Wang

    2011-06-01

    Full Text Available The objective of this project is to develop a flexible observation mode for a geomagnetic abnormal phenomena tracking system. The instrument, based on ring core fluxgate magnetometer technology, improves the field environment performance. Using wireless technology provides on-the-spot mobile networking for the observational data, with efficient access to the earthquake precursor observation network. It provides a powerful detection method for earthquake short-term prediction through installation of a low-noise fluxgate magnetometer array, intensely observing the phenomenon of geomagnetic disturbances and abnormal low-frequency electromagnetic signals in different latitudes, then carrying out observational data processing and exploring the relationship between earthquake activity and geomagnetic field changes.

  12. Machine Learning Based Localization and Classification with Atomic Magnetometers

    Science.gov (United States)

    Deans, Cameron; Griffin, Lewis D.; Marmugi, Luca; Renzoni, Ferruccio

    2018-01-01

    We demonstrate identification of position, material, orientation, and shape of objects imaged by a Rb 85 atomic magnetometer performing electromagnetic induction imaging supported by machine learning. Machine learning maximizes the information extracted from the images created by the magnetometer, demonstrating the use of hidden data. Localization 2.6 times better than the spatial resolution of the imaging system and successful classification up to 97% are obtained. This circumvents the need of solving the inverse problem and demonstrates the extension of machine learning to diffusive systems, such as low-frequency electrodynamics in media. Automated collection of task-relevant information from quantum-based electromagnetic imaging will have a relevant impact from biomedicine to security.

  13. Suppression of the Nonlinear Zeeman Effect and Heading Error in Earth-Field-Range Alkali-Vapor Magnetometers.

    Science.gov (United States)

    Bao, Guzhi; Wickenbrock, Arne; Rochester, Simon; Zhang, Weiping; Budker, Dmitry

    2018-01-19

    The nonlinear Zeeman effect can induce splitting and asymmetries of magnetic-resonance lines in the geophysical magnetic-field range. This is a major source of "heading error" for scalar atomic magnetometers. We demonstrate a method to suppress the nonlinear Zeeman effect and heading error based on spin locking. In an all-optical synchronously pumped magnetometer with separate pump and probe beams, we apply a radio-frequency field which is in phase with the precessing magnetization. This results in the collapse of the multicomponent asymmetric magnetic-resonance line with ∼100  Hz width in the Earth-field range into a single peak with a width of 22 Hz, whose position is largely independent of the orientation of the sensor within a range of orientation angles. The technique is expected to be broadly applicable in practical magnetometry, potentially boosting the sensitivity and accuracy of Earth-surveying magnetometers by increasing the magnetic-resonance amplitude, decreasing its width, and removing the important and limiting heading-error systematic.

  14. Suppression of the Nonlinear Zeeman Effect and Heading Error in Earth-Field-Range Alkali-Vapor Magnetometers

    Science.gov (United States)

    Bao, Guzhi; Wickenbrock, Arne; Rochester, Simon; Zhang, Weiping; Budker, Dmitry

    2018-01-01

    The nonlinear Zeeman effect can induce splitting and asymmetries of magnetic-resonance lines in the geophysical magnetic-field range. This is a major source of "heading error" for scalar atomic magnetometers. We demonstrate a method to suppress the nonlinear Zeeman effect and heading error based on spin locking. In an all-optical synchronously pumped magnetometer with separate pump and probe beams, we apply a radio-frequency field which is in phase with the precessing magnetization. This results in the collapse of the multicomponent asymmetric magnetic-resonance line with ˜100 Hz width in the Earth-field range into a single peak with a width of 22 Hz, whose position is largely independent of the orientation of the sensor within a range of orientation angles. The technique is expected to be broadly applicable in practical magnetometry, potentially boosting the sensitivity and accuracy of Earth-surveying magnetometers by increasing the magnetic-resonance amplitude, decreasing its width, and removing the important and limiting heading-error systematic.

  15. General theory of detection of signal induced in vibrating magnetometer

    International Nuclear Information System (INIS)

    Pacyna, A.W.

    1980-01-01

    Assuming the point dipole approximation only and making use of the vectorial notation, signal (EMF) induced in a single-turn pick-up coil of the vibrating magnetometer are calculated for the case of any orientation of the coil, of vibration axis and of the magnetic moment of the sample. On the basis of formula obtained, three types of measurement geometries have been distinquished and for these the qualitative analysis is made. (author)

  16. Swarm Optimization-Based Magnetometer Calibration for Personal Handheld Devices

    Directory of Open Access Journals (Sweden)

    Naser El-Sheimy

    2012-09-01

    Full Text Available Inertial Navigation Systems (INS consist of accelerometers, gyroscopes and a processor that generates position and orientation solutions by integrating the specific forces and rotation rates. In addition to the accelerometers and gyroscopes, magnetometers can be used to derive the user heading based on Earth’s magnetic field. Unfortunately, the measurements of the magnetic field obtained with low cost sensors are usually corrupted by several errors, including manufacturing defects and external electro-magnetic fields. Consequently, proper calibration of the magnetometer is required to achieve high accuracy heading measurements. In this paper, a Particle Swarm Optimization (PSO-based calibration algorithm is presented to estimate the values of the bias and scale factor of low cost magnetometers. The main advantage of this technique is the use of the artificial intelligence which does not need any error modeling or awareness of the nonlinearity. Furthermore, the proposed algorithm can help in the development of Pedestrian Navigation Devices (PNDs when combined with inertial sensors and GPS/Wi-Fi for indoor navigation and Location Based Services (LBS applications.

  17. In-Flight Calibration Processes for the MMS Fluxgate Magnetometers

    Science.gov (United States)

    Bromund, K. R.; Leinweber, H. K.; Plaschke, F.; Strangeway, R. J.; Magnes, W.; Fischer, D.; Nakamura, R.; Anderson, B. J.; Russell, C. T.; Baumjohann, W.; hide

    2015-01-01

    The calibration effort for the Magnetospheric Multiscale Mission (MMS) Analog Fluxgate (AFG) and DigitalFluxgate (DFG) magnetometers is a coordinated effort between three primary institutions: University of California, LosAngeles (UCLA); Space Research Institute, Graz, Austria (IWF); and Goddard Space Flight Center (GSFC). Since thesuccessful deployment of all 8 magnetometers on 17 March 2015, the effort to confirm and update the groundcalibrations has been underway during the MMS commissioning phase. The in-flight calibration processes evaluatetwelve parameters that determine the alignment, orthogonalization, offsets, and gains for all 8 magnetometers usingalgorithms originally developed by UCLA and the Technical University of Braunschweig and tailored to MMS by IWF,UCLA, and GSFC. We focus on the processes run at GSFC to determine the eight parameters associated with spin tonesand harmonics. We will also discuss the processing flow and interchange of parameters between GSFC, IWF, and UCLA.IWF determines the low range spin axis offsets using the Electron Drift Instrument (EDI). UCLA determines the absolutegains and sensor azimuth orientation using Earth field comparisons. We evaluate the performance achieved for MMS andgive examples of the quality of the resulting calibrations.

  18. New Magneto-Inductive DC Magnetometer for Space Missions

    Science.gov (United States)

    Moldwin, M.; Bronner, B.; Regoli, L.; Thoma, J.; Shen, A.; Jenkins, G.; Cutler, J.

    2017-12-01

    A new magneto-inductive DC magnetometer is being developed at the University of Michigan that provides fluxgate quality measurements in a low mass, volume, power and cost package. The magnetometer enables constellation-class missions not only due to its low-resource requirements, but also its potential for commercial integrated circuit fabrication. The magneto-inductive operating principle is based on a simple resistance-inductor (RL) circuit and involves measurement of the time it takes to charge and discharge the inductor between an upper and lower threshold by means of a Schmitt trigger oscillator. This time is proportional to the inductance that in turn is proportional to the field strength. We have modeled the operating principle in the circuit simulator SPICE and have built a proto-type using modified commercial sensors. The performance specifications include a dynamic range over the full-Earth's field, sampling rates up to 80 Hz, sensor and electronics mass of about 30 g, circuit board and sensor housing volume of magnetometer.

  19. A spinner magnetometer for large Apollo lunar samples

    Science.gov (United States)

    Uehara, M.; Gattacceca, J.; Quesnel, Y.; Lepaulard, C.; Lima, E. A.; Manfredi, M.; Rochette, P.

    2017-10-01

    We developed a spinner magnetometer to measure the natural remanent magnetization of large Apollo lunar rocks in the storage vault of the Lunar Sample Laboratory Facility (LSLF) of NASA. The magnetometer mainly consists of a commercially available three-axial fluxgate sensor and a hand-rotating sample table with an optical encoder recording the rotation angles. The distance between the sample and the sensor is adjustable according to the sample size and magnetization intensity. The sensor and the sample are placed in a two-layer mu-metal shield to measure the sample natural remanent magnetization. The magnetic signals are acquired together with the rotation angle to obtain stacking of the measured signals over multiple revolutions. The developed magnetometer has a sensitivity of 5 × 10-7 Am2 at the standard sensor-to-sample distance of 15 cm. This sensitivity is sufficient to measure the natural remanent magnetization of almost all the lunar basalt and breccia samples with mass above 10 g in the LSLF vault.

  20. A spinner magnetometer for large Apollo lunar samples.

    Science.gov (United States)

    Uehara, M; Gattacceca, J; Quesnel, Y; Lepaulard, C; Lima, E A; Manfredi, M; Rochette, P

    2017-10-01

    We developed a spinner magnetometer to measure the natural remanent magnetization of large Apollo lunar rocks in the storage vault of the Lunar Sample Laboratory Facility (LSLF) of NASA. The magnetometer mainly consists of a commercially available three-axial fluxgate sensor and a hand-rotating sample table with an optical encoder recording the rotation angles. The distance between the sample and the sensor is adjustable according to the sample size and magnetization intensity. The sensor and the sample are placed in a two-layer mu-metal shield to measure the sample natural remanent magnetization. The magnetic signals are acquired together with the rotation angle to obtain stacking of the measured signals over multiple revolutions. The developed magnetometer has a sensitivity of 5 × 10 -7 Am 2 at the standard sensor-to-sample distance of 15 cm. This sensitivity is sufficient to measure the natural remanent magnetization of almost all the lunar basalt and breccia samples with mass above 10 g in the LSLF vault.

  1. Particle swarm optimization algorithm based low cost magnetometer calibration

    Science.gov (United States)

    Ali, A. S.; Siddharth, S., Syed, Z., El-Sheimy, N.

    2011-12-01

    Inertial Navigation Systems (INS) consist of accelerometers, gyroscopes and a microprocessor provide inertial digital data from which position and orientation is obtained by integrating the specific forces and rotation rates. In addition to the accelerometers and gyroscopes, magnetometers can be used to derive the absolute user heading based on Earth's magnetic field. Unfortunately, the measurements of the magnetic field obtained with low cost sensors are corrupted by several errors including manufacturing defects and external electro-magnetic fields. Consequently, proper calibration of the magnetometer is required to achieve high accuracy heading measurements. In this paper, a Particle Swarm Optimization (PSO) based calibration algorithm is presented to estimate the values of the bias and scale factor of low cost magnetometer. The main advantage of this technique is the use of the artificial intelligence which does not need any error modeling or awareness of the nonlinearity. The estimated bias and scale factor errors from the proposed algorithm improve the heading accuracy and the results are also statistically significant. Also, it can help in the development of the Pedestrian Navigation Devices (PNDs) when combined with the INS and GPS/Wi-Fi especially in the indoor environments

  2. In-Flight Calibration Processes for the MMS Fluxgate Magnetometers

    Science.gov (United States)

    Bromund, K. R.; Leinweber, H. K.; Plaschke, F.; Strangeway, R. J.; Magnes, W.; Fischer, D.; Nakamura, R.; Anderson, B. J.; Russell, C. T.; Baumjohann, W.; Chutter, M.; Torbert, R. B.; Le, G.; Slavin, J. A.; Kepko, L.

    2015-12-01

    The calibration effort for the Magnetospheric Multiscale Mission (MMS) Analog Fluxgate (AFG) and Digital Fluxgate (DFG) magnetometers is a coordinated effort between three primary institutions: University of California, Los Angeles (UCLA); Space Research Institute, Graz, Austria (IWF); and Goddard Space Flight Center (GSFC). Since the successful deployment of all 8 magnetometers on 17 March 2015, the effort to confirm and update the ground calibrations has been underway during the MMS commissioning phase. The in-flight calibration processes evaluate twelve parameters that determine the alignment, orthogonalization, offsets, and gains for all 8 magnetometers using algorithms originally developed by UCLA and the Technical University of Braunschweig and tailored to MMS by IWF, UCLA, and GSFC. We focus on the processes run at GSFC to determine the eight parameters associated with spin tones and harmonics. We will also discuss the processing flow and interchange of parameters between GSFC, IWF, and UCLA. IWF determines the low range spin axis offsets using the Electron Drift Instrument (EDI). UCLA determines the absolute gains and sensor azimuth orientation using Earth field comparisons. We evaluate the performance achieved for MMS and give examples of the quality of the resulting calibrations.

  3. Through-barrier electromagnetic imaging with an atomic magnetometer.

    Science.gov (United States)

    Deans, Cameron; Marmugi, Luca; Renzoni, Ferruccio

    2017-07-24

    We demonstrate the penetration of thick metallic and ferromagnetic barriers for imaging of conductive targets underneath. Our system is based on an 85 Rb radio-frequency atomic magnetometer operating in electromagnetic induction imaging modality in an unshielded environment. Detrimental effects, including unpredictable magnetic signatures from ferromagnetic screens and variations in the magnetic background, are automatically compensated by active compensation coils controlled by servo loops. We exploit the tunability and low-frequency sensitivity of the atomic magnetometer to directly image multiple conductive targets concealed by a 2.5 mm ferromagnetic steel shield and/or a 2.0 mm aluminium shield, in a single scan. The performance of the atomic magnetometer allows imaging without any prior knowledge of the barriers or the targets, and without the need of background subtraction. A dedicated edge detection algorithm allows automatic estimation of the targets' size within 3.3 mm and of their position within 2.4 mm. Our results prove the feasibility of a compact, sensitive and automated sensing platform for imaging of concealed objects in a range of applications, from security screening to search and rescue.

  4. Detection Range of Airborne Magnetometers in Magnetic Anomaly Detection

    Directory of Open Access Journals (Sweden)

    Chengjing Li

    2015-11-01

    Full Text Available Airborne magnetometers are utilized for the small-range search, precise positioning, and identification of the ferromagnetic properties of underwater targets. As an important performance parameter of sensors, the detection range of airborne magnetometers is commonly set as a fixed value in references regardless of the influences of environment noise, target magnetic properties, and platform features in a classical model to detect airborne magnetic anomalies. As a consequence, deviation in detection ability analysis is observed. In this study, a novel detection range model is proposed on the basis of classic detection range models of airborne magnetometers. In this model, probability distribution is applied, and the magnetic properties of targets and the environment noise properties of a moving submarine are considered. The detection range model is also constructed by considering the distribution of the moving submarine during detection. A cell-averaging greatest-of-constant false alarm rate test method is also used to calculate the detection range of the model at a desired false alarm rate. The detection range model is then used to establish typical submarine search probabilistic models. Results show that the model can be used to evaluate not only the effects of ambient magnetic noise but also the moving and geomagnetic features of the target and airborne detection platform. The model can also be utilized to display the actual operating range of sensor systems.

  5. A broadband two axis flux-gate magnetometer

    Directory of Open Access Journals (Sweden)

    P. Palangio

    1998-06-01

    Full Text Available A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.

  6. Electromagnetic Waves with Frequencies Near the Local Proton Gryofrequency: ISEF-3 1 AU Observations

    Science.gov (United States)

    Tsurutani, B.

    1993-01-01

    Low Frequency electromagnetic waves with periods near the local proton gyrofrequency have been detected near 1 AU by the magnetometer onboard ISEE-3. For these 1 AU waves two physical processes are possible: solar wind pickup of nuetral (interstellar?) particles and generation by relativistic electron beams propagating from the Sun.

  7. A Proton-Cyclotron Wave Storm Generated by Unstable Proton Distribution Functions in the Solar Wind

    Science.gov (United States)

    Wicks, R. T.; Alexander, R. L.; Stevens, M.; Wilson, L. B., III; Moya, P. S.; Vinas, A.; Jian, L. K.; Roberts, D. A.; O’Modhrain, S.; Gilbert, J. A.; hide

    2016-01-01

    We use audification of 0.092 seconds cadence magnetometer data from the Wind spacecraft to identify waves with amplitudes greater than 0.1 nanoteslas near the ion gyrofrequency (approximately 0.1 hertz) with duration longer than 1 hour during 2008. We present one of the most common types of event for a case study and find it to be a proton-cyclotron wave storm, coinciding with highly radial magnetic field and a suprathermal proton beam close in density to the core distribution itself. Using linear Vlasov analysis, we conclude that the long-duration, large-amplitude waves are generated by the instability of the proton distribution function. The origin of the beam is unknown, but the radial field period is found in the trailing edge of a fast solar wind stream and resembles other events thought to be caused by magnetic field footpoint motion or interchange reconnection between coronal holes and closed field lines in the corona.

  8. Miniature scientific-grade induction magnetometer for cubesats

    Science.gov (United States)

    Pronenko, Vira

    2017-04-01

    One of the main areas of space research is the study and forecasting of space weather. The society is more and more depending nowadays on satellite technology and communications, so it is vital to understand the physical process in the solar-terrestrial system which may disturb them. Besides the solar radiation and Space Weather effects, the Earth's ionosphere is also modified by the ever increasing industrial activity. There have been also multiple reports relating VLF and ELF wave activity to atmospheric storms and geological processes, such as earthquakes and volcanic activity. For advancing in these fields, the AC magnetic field permanent monitoring is crucial. Using the cubesat technology would allow increasing the number of measuring points dramatically. It is necessary to mention that the cubesats use for scientific research requires the miniaturization of scientific sensors what is a serious problem because the reduction of their dimensions leads, as a rule, to the parameters degradation, especially of sensitivity threshold. Today, there is no basic model of a sensitive miniature induction magnetometer. Even the smallest one of the known - for the Bepi-Colombo mission to Mercury - is too big for cubesats. The goal of the present report is to introduce the new design of miniature three-component sensor for measurement of alternative vector magnetic fields - induction magnetometer (IM). The study directions were concentrated on the ways and possibilities to create the miniature magnetometer with best combination of parameters. For this a set of scientific and technological problems, mostly aimed at the sensor construction improvement, was solved. The most important parameter characterizing magnetometer quality is its own magnetic noise level (NL). The analysis of the NL influencing factors is made and the ways to decrease it are discussed in the report. Finally, the LEMI-151 IM was developed for the SEAM cubesat mission with optimal performances within the

  9. Multilayer Based Technology to Build RTD Fluxgate Magnetometer

    Directory of Open Access Journals (Sweden)

    B. ANDO

    2006-03-01

    Full Text Available In this paper we discuss the main features of the Residence Times Difference Fluxgate Magnetometer. A low-cost technology, negligible onboard power requirements and the intrinsic digital form of the readout signal are the main advantages of the proposed strategy. Results obtained show the possibility to realise low-cost devices exploiting Printed Circuit Board (PCB technology for applications requiring resolution in the nanotesla range as the ferrous object (or particles detection, being the performance obtained suitable to detect the presence or the transit of ferrous materials via their interaction with the geomagnetic field.

  10. Three axis vector atomic magnetometer utilizing polarimetric technique

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Swarupananda, E-mail: spradhan@barc.gov.in, E-mail: pradhans75@gmail.com [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India and Homi Bhabha National Institute, Department of Atomic Energy, Mumbai 400094 (India)

    2016-09-15

    The three axis vector magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer geometry offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only the reflected signal (one polarization component) from the polarimeter and thus can be easily expanded to make spatial array of detectors and/or high sensitivity field gradient measurement as required for biomedical application.

  11. The simple procedure for the fluxgate magnetometers calibration

    Science.gov (United States)

    Marusenkov, Andriy

    2014-05-01

    The fluxgate magnetometers are widely used in geophysics investigations including the geomagnetic field monitoring at the global network of geomagnetic observatories as well as for electromagnetic sounding of the Earth's crust conductivity. For solving these tasks the magnetometers have to be calibrated with an appropriate level of accuracy. As a particular case, the ways to satisfy the recent requirements to the scaling and orientation errors of 1-second INTERNAGNET magnetometers are considered in the work. The goal of the present study was to choose a simple and reliable calibration method for estimation of scale factors and angular errors of the three-axis magnetometers in the field. There are a large number of the scalar calibration methods, which use a free rotation of the sensor in the calibration field followed by complicated data processing procedures for numerical solution of the high-order equations set. The chosen approach also exploits the Earth's magnetic field as a calibrating signal, but, in contrast to other methods, the sensor has to be oriented in some particular positions in respect to the total field vector, instead of the sensor free rotation. This allows to use very simple and straightforward linear computation formulas and, as a result, to achieve more reliable estimations of the calibrated parameters. The estimation of the scale factors is performed by the sequential aligning of each component of the sensor in two positions: parallel and anti-parallel to the Earth's magnetic field vector. The estimation of non-orthogonality angles between each pair of components is performed after sequential aligning of the components at the angles +/- 45 and +/- 135 degrees of arc in respect to the total field vector. Due to such four positions approach the estimations of the non-orthogonality angles are invariant to the zero offsets and non-linearity of transfer functions of the components. The experimental justifying of the proposed method by means of the

  12. A simple vibrating sample magnetometer for macroscopic samples

    Science.gov (United States)

    Lopez-Dominguez, V.; Quesada, A.; Guzmán-Mínguez, J. C.; Moreno, L.; Lere, M.; Spottorno, J.; Giacomone, F.; Fernández, J. F.; Hernando, A.; García, M. A.

    2018-03-01

    We here present a simple model of a vibrating sample magnetometer (VSM). The system allows recording magnetization curves at room temperature with a resolution of the order of 0.01 emu and is appropriated for macroscopic samples. The setup can be mounted with different configurations depending on the requirements of the sample to be measured (mass, saturation magnetization, saturation field, etc.). We also include here examples of curves obtained with our setup and comparison curves measured with a standard commercial VSM that confirms the reliability of our device.

  13. Quantifying the In-Flight Yaw, Pitch, and Roll of a Semi-Rigidly Mounted Potassium Vapour Magnetometer Suspended Under a Heavy-Lift Multi-Rotor UAV and its Impact on Data Quality

    Science.gov (United States)

    Walter, C. A.; Braun, A.; Fotopoulos, G.

    2017-12-01

    Research is being conducted to develop an Unmanned Aerial System (UAS) that is capable of reliably and efficiently collecting high resolution, industry standard magnetic data (magnetic data with a fourth difference of +/- 0.05 nT) via an optically pumped vapour magnetometer. The benefits of developing a UAS with these capabilities include improvements in the resolution of localized airborne surveys (2.5 km by 2.5 km) and the ability to conduct 3D magnetic gradiometry surveys in the observation gap evident between traditional terrestrial and manned airborne magnetic surveys (surface elevation up to 120 m). Quantifying the extent of an optically pumped vapour magnetometer's 3D orientation variations, while in-flight and suspended under a UAS, is a significant advancement to existing knowledge as optically pumped magnetometers have an orientation-dependent (to the primary magnetic field vector) process for measuring the magnetic field. This study investigates the orientation characteristics of a GEM Systems potassium vapour magnetometer, GSMP-35U, while semi-rigidly suspended 3 m under a DJI S900, heavy-lift multi-rotor UAV (Unmanned Aerial Vehicle) during an airborne surveying campaign conducted Northeast of Thunder Bay, Ontario, Canada. A nine degrees of freedom IMU (Inertial Measurement Unit), the Adafruit GY-80, was used to quantify the 3D orientation variations (yaw, pitch and roll) of the magnetic sensor during flight. The orientation and magnetic datasets were indexed and linked with a date and time stamp (within 1 ms) via a Raspberry Pi 2, acting as an on-board computer and data storage system. Analysing the two datasets allowed for the in-flight orientation variations of the potassium vapour magnetometer to be directly compared with the gathered magnetic and signal quality data of the magnetometer. The in-flight orientation characteristics of the magnetometer were also quantified for a range of air-speeds and flight maneuvers throughout the survey. Overall

  14. On the control of magnetic perturbing field onboard landers: the Magnetometer Protection program for the ESA ExoMars/Humboldt MSMO magnetometer experiment

    DEFF Research Database (Denmark)

    Menvielle, M.; Primdahl, Fritz; Brauer, Peter

    to planetary research. The major difficulty in implementing a magnetometer experiment onboard a lander is to achieve at acceptable costs a good Magnetometer Protection, namely to control the perturbing magnetic field generated by the lander during operations at the planetary surfa ce, so as to achieve...... scientific payload in the frame of the ESA ExoMars mission. Experience from previous missions constitutes the background for the MSMO Magnetometer Protection strategy. DC and AC lander generated magnetic perturbations are discussed, with particular attention to those related to solar generators. Emphasis...... and very resource consuming....

  15. Prospecting For Magnetite Ore Deposits With A Innovative Sensor's of Unique Fundamentally New Magnetometer.

    Science.gov (United States)

    Emelianenko, T. I.; Tachaytdinov, R. S.; Sarichev, V. F.; Kotov, B. V.; Susoeva, G. N.

    After careful study of principles and abilities of all existing magnetmeters of all three revolutions in magnetic prospecting we have come to the conclusion that they cannot solve local guestions of the magnetic prospecting or determine centre coordinates of magnetite ore body before drilling Electromagnetism lows and achievents magnetprospectings and radioelectronics of all 20th century serve as a theoretical base of the "locator". While creating this cardinally new magnetmeter , we borrowed different things from radio-prospectors, magnetprospectors, wireless operators and combined all of them while creating the "locators''. The "locators' construction is bas ed on the "magnetic intensification" principle ,owing to which this "locators" are characterised by hight sensitiveness and ability to determine centers of even little commercial magnetite ore deposits with relatively weak magnetic anomalies. The main advantage of the "locators" over existing ones is that it can solve local questions determine centre coordinates. A remarkably simple locator construction determine direction of the on-surface measurings towards the ore body centre and gives approximate prognosis resourses before/withour/ drilling. The "locators" were worked out for the first time in history , they have 2 licences. The fundamental design and drawbacks of the existing magnetometers have been inherited from the original magnetometre dating back two or three hundred years. The developers of the existing magnetometres have all gone along the same well- beaten track of replacing the primitive sensor in the form of a piece of ore hung on a string at first by an arrow sensor and later by magnetically oriented protons and quanta, with amplification of the sensors' OUTPUT signal. Furthermore, all the existing magnetometres are imperfect in that they, lacking the directivity of the ground-level magnetic measurements, only record the overall magnetic vector field generated by all the ore bodies around the

  16. Exploiting nonlinear dynamics in a coupled-core fluxgate magnetometer

    International Nuclear Information System (INIS)

    Bulsara, Adi R; In, Visarath; Kho, Andy; Longhini, Patrick; Neff, Joe; Anderson, Gregory; Obra, Christopher; Palacios, Antonio; Baglio, Salvatore; Ando, Bruno

    2008-01-01

    Unforced bistable dynamical systems having dynamics of the general form τ F x-dot (t)=-∇ x U(x) cannot oscillate (i.e. switch between their stable attractors). However, a number of such systems subject to carefully crafted coupling schemes have been shown to exhibit oscillatory behavior under carefully chosen operating conditions. This behavior, in turn, affords a new mechanism for the detection and quantification of target signals having magnitude far smaller than the energy barrier height in the potential energy function U(x) for a single (uncoupled) element. The coupling-induced oscillations are a feature that appears to be universal in systems described by bi- or multi-stable potential energy functions U(x), and are being exploited in a new class of dynamical sensors being developed by us. In this work we describe one of these devices, a coupled-core fluxgate magnetometer (CCFM), whose operation is underpinned by this dynamic behavior. We provide an overview of the underlying dynamics and, also, quantify the performance of our test device; in particular, we provide a quantitative performance comparison to a conventional (single-core) fluxgate magnetometer via a 'resolution' parameter that embodies the device sensitivity (the slope of its input–output transfer characteristic) as well as the noise floor

  17. A radiation hardened digital fluxgate magnetometer for space applications

    Science.gov (United States)

    Miles, D. M.; Bennest, J. R.; Mann, I. R.; Millling, D. K.

    2013-09-01

    Space-based measurements of Earth's magnetic field are required to understand the plasma processes responsible for energising particles in the Van Allen radiation belts and influencing space weather. This paper describes a prototype fluxgate magnetometer instrument developed for the proposed Canadian Space Agency's (CSA) Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS) mission and which has applications in other space and suborbital applications. The magnetometer is designed to survive and operate in the harsh environment of Earth's radiation belts and measure low-frequency magnetic waves, the magnetic signatures of current systems, and the static background magnetic field. The new instrument offers improved science data compared to its predecessors through two key design changes: direct digitisation of the sensor and digital feedback from two cascaded pulse-width modulators combined with analog temperature compensation. These provide an increase in measurement bandwidth up to 450 Hz with the potential to extend to at least 1500 Hz. The instrument can resolve 8 pT on a 65 000 nT field with a magnetic noise of less than 10 pT/√Hz at 1 Hz. This performance is comparable with other recent digital fluxgates for space applications, most of which use some form of sigma-delta (ΣΔ) modulation for feedback and omit analog temperature compensation. The prototype instrument was successfully tested and calibrated at the Natural Resources Canada Geomagnetics Laboratory.

  18. Multi-flux-transformer MRI detection with an atomic magnetometer.

    Science.gov (United States)

    Savukov, Igor; Karaulanov, Todor

    2014-12-01

    Recently, anatomical ultra-low field (ULF) MRI has been demonstrated with an atomic magnetometer (AM). A flux-transformer (FT) has been used for decoupling MRI fields and gradients to avoid their negative effects on AM performance. The field of view (FOV) was limited because of the need to compromise between the size of the FT input coil and MRI sensitivity per voxel. Multi-channel acquisition is a well-known solution to increase FOV without significantly reducing sensitivity. In this paper, we demonstrate twofold FOV increase with the use of three FT input coils. We also show that it is possible to use a single atomic magnetometer and single acquisition channel to acquire three independent MRI signals by applying a frequency-encoding gradient along the direction of the detection array span. The approach can be generalized to more channels and can be critical for imaging applications of non-cryogenic ULF MRI where FOV needs to be large, including head, hand, spine, and whole-body imaging. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Swarm's absolute magnetometer experimental vector mode, an innovative capability for space magnetometry

    DEFF Research Database (Denmark)

    Hulot, Gauthier; Vigneron, Pierre; Leger, Jean-Michel

    2015-01-01

    , combining ASM scalar data with independent uxgate magnetometer vector data. The high level of agreement between these models demonstrates the potential of the ASM's vector mode for data quality control and as a stand alone magnetometer, and illustrates the way the evolution of key eld features can easily...

  20. Preliminary Report: DESiGN and Test Result of KSR-3 Rocket Magnetometers

    Directory of Open Access Journals (Sweden)

    Hyo-Min Kim

    2000-12-01

    Full Text Available The solar wind contributes to the formation of unique space environment called the Earth's magnetosphere by various interactions with the Earth's magnetic field. Thus the solar-terrestrial environment affects the Earth's magnetic field, which can be observed with an instrument for the magnetic field measurement, the magnetometer usually mounted on the rocket and the satellite and based on the ground observatory. The magnetometer is a useful instrument for the spacecraft attitude control as well as the Earth's magnetic field measurements for a scientific purpose. In this paper, we present the preliminary design and test results of the two onboard magnetometers of KARI's (Korea Aerospace Research Institute sounding rocket, KSR-3, which will be launched four times during the period of 2001-02. The KSR-3 magnetometers consist of the fluxgate magnetometer, MAG/AIM (Attitude Information Magnetometer for acquiring the rocket flight attitude information, and of the search-coil magnetometer, MAG/SIM (Scientific Investigation Magnetometer for the observation of the Earth's magnetic field fluctuations. With the MAG/AIM, the 3-axis attitude information can be acquired by the comparison of the resulting dc magnetic vector field with the IGRF (International Geomagnetic Reference Field. The Earth's magnetic field fluctuations ranging from 10 to 1,000 Hz can also be observed with the MAG/SIM measurement.

  1. Closed-cycle gas flow system for cooling a HTc dc-SQUID magnetometer

    NARCIS (Netherlands)

    Bosch, van den P.J.; Holland, H.J.; Brake, ter H.J.M.; Rogalla, H.

    1994-01-01

    A closed-cycle gas flow system for cooling a high-crit. temp. d.c.-superconducting quantum interference device (SQUID) magnetometer by means of a cryocooler has been designed, constructed and tested. The magnetometer is aimed to measure heart signals with a sensitivity of 0.1 pT/Hz1/2. The required

  2. The absolute magnetometers on board Swarm, lessons learned from more than two years in space

    DEFF Research Database (Denmark)

    Hulot, Gauthier; Leger, Jean-Michel; Vigneron, Pierre

    ESA's Swarm satellites carry 4He absolute magnetometers (ASM), designed by CEA-Léti and developed in partnership with CNES. These instruments are the first-ever space-borne magnetometers to use a common sensor to simultaneously deliver 1Hz independent absolute scalar and vector readings of the ma...

  3. Correlation between fluxgate and SQUID magnetometer data sets for geomagnetic storms

    Directory of Open Access Journals (Sweden)

    Matladi Thabang

    2014-01-01

    Full Text Available There has always been a need to monitor the near Earth's magnetic field, as this monitoring provides understanding and possible predictions of Space Weather events such as geomagnetic storms. Conventional magnetometers such as fluxgates have been used for decades for Space Weather research. The use of highly sensitive magnetometers such as Superconducting QUantum Interference Devices (SQUIDs, promise to give more insight into Space Weather. SQUIDs are relatively recent types of magnetometers that exploit the superconductive effects of flux quantization and Josephson tunneling to measure magnetic flux. SQUIDs have a very broad bandwidth compared to most conventional magnetometers and can measure magnetic flux as low as a few femtotesla. Since SQUIDs have never been used in Space Weather research, unshielded, it is necessary to investigate if they can be reliable Space Weather instruments. The validation is performed by comparing the frequency content of the SQUID and fluxgate magnetometers, as reported by Phiri.

  4. Associating ground magnetometer observations with current or voltage generators

    DEFF Research Database (Denmark)

    Hartinger, M. D.; Xu, Z.; Clauer, C. R.

    2017-01-01

    A circuit analogy for magnetosphere-ionosphere current systems has two extremes for driversof ionospheric currents: ionospheric elec tric fields/voltages constant while current/conductivity vary—the“voltage generator”—and current constant while electric field/conductivity vary—the “current generator.......”Statistical studies of ground magnetometer observations associated with dayside Transient High LatitudeCurrent Systems (THLCS) driven by similar mechanisms find contradictory results using this paradigm:some studies associate THLCS with voltage generators, others with current generators. We argue that mostof...... these two assumptions substantially alter expectations for magnetic perturbations associatedwith either a current or a voltage generator. Our results demonstrate that before interpreting groundmagnetometer observations of THLCS in the context of current/voltage generators, the location...

  5. A three-axis SQUID-based absolute vector magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Schönau, T.; Schmelz, M.; Stolz, R.; Anders, S.; Linzen, S.; Meyer, H.-G. [Department of Quantum Detection, Leibniz Institute of Photonic Technology, Jena 07745 (Germany); Zakosarenko, V.; Meyer, M. [Supracon AG, An der Lehmgrube 11, Jena 07751 (Germany)

    2015-10-15

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth’s magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz{sup 1/2}. The width of superconducting strip lines is restricted to less than 6 μm in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μT amplitude without the need for recalibration.

  6. Magnetometer-Augmented IMU Simulator: In-Depth Elaboration

    Directory of Open Access Journals (Sweden)

    Thomas Brunner

    2015-03-01

    Full Text Available The location of objects is a growing research topic due, for instance, to the expansion of civil drones or intelligent vehicles. This expansion was made possible through the development of microelectromechanical systems (MEMS, inexpensive and miniaturized inertial sensors. In this context, this article describes the development of a new simulator which generates sensor measurements, giving a specific input trajectory. This will allow the comparison of pose estimation algorithms. To develop this simulator, the measurement equations of every type of sensor have to be analytically determined. To achieve this objective, classical kinematic equations are used for the more common sensors, i.e., accelerometers and rate gyroscopes. As nowadays, the MEMS inertial measurement units (IMUs are generally magnetometer-augmented, an absolute world magnetic model is implemented. After the determination of the perfect measurement (through the error-free sensor models, realistic error models are developed to simulate real IMU behavior. Finally, the developed simulator is subjected to different validation tests.

  7. Miniaturized digital fluxgate magnetometer for small spacecraft applications

    International Nuclear Information System (INIS)

    Forslund, Åke; Ivchenko, Nickolay; Olsson, Göran; Edberg, Terry; Belyayev, Serhiy; Marusenkov, Andriy

    2008-01-01

    A novel design of an Earth field digital fluxgate magnetometer is presented, the small magnetometer in low-mass experiment (SMILE). The combination of a number of new techniques results in significant miniaturization of both sensor and electronics. The design uses a sensor with volume compensation, combining three dual rod cores in a Macor® cube with the side dimension of 20 mm. Use of volume compensation provides high geometrical stability of the axes and improved performance compared to component compensated sensors. The sensor is operated at an excitation frequency of 8 kHz. Most of the instrument functionality is combined in a digital signal processing core, implemented in a field programmable gate array (FPGA). The pick-up signal is digitized after amplification and filtering, and values of compensation currents for each of the axes are determined by a digital correlation algorithm, equivalent to a matched filter, and are fed to a hybrid pulse-width modulation/delta-sigma digital-to-analogue converter driving the currents through the compensation coils. Using digital design makes the instrument very flexible, reduces power consumption and opens possibilities for the customization of the operation modes. The current implementation of the design is based on commercial off-the-shelf components. A calibration of the SMILE instrument was carried out at the Nurmijärvi Geophysical Observatory, showing high linearity (within 6 nT on the whole ±50 µT scale), good orthogonality (22 arcmin) and very good temperature stability of the axes

  8. Testing the three axis magnetometer and gradiometer MOURA and data comparison on San Pablo de los Montes Observatory.

    Science.gov (United States)

    Belen Fernandez, Ana; Sanz, Ruy; Covisa, Pablo; Tordesillas, Jose Manuel; Diaz-Michelena, Marina

    2013-04-01

    A magnetometer and gradiometer named MOURA has been developed with the objective to measure the magnetic field on Mars in the frame of Mars MetNet Precursor Mission (MMPM) [1]. MOURA is a compact, miniaturized, intelligent and low cost instrument, based on two sets of triaxial magnetometers separated one centimeter from each other to do gradiometry studies. It has a resolution of 2.2 nT, and a field range of + 65μT, which can be extended to +130 μT when sensors are saturated. [2] These sensor heads are Anisotropic MagnetoResistances (AMR) Commercial-Off-The-Shelf (COTS) by Honeywell, specifically HMC1043, which has been selected due to their relative low consumption, weight and size, factors very important for the mission with very limited mass and power budget (shared 150 g for three full payloads). Also, this technology has been previously successfully employed on board Unmanned Aerial Vehicles (UAV) to perform geomagnetic surveys in extreme conditions areas [3], and in several space missions for different applications. [4] After the development of the MOURA Engineering Qualification Model (EQM) in November 2011, an exhaustive set of tests have been performed to validate and fully characterize the instrument. Compensation equations have been derived for the temperature corrections in the operation range (between -135 °C and 30 °C) in controlled environments. These compensation equations have been applied to field data, which have shown to follow the daily Earth's magnetic field variations as registered by San Pablo Geomagnetic Observatory (IAGA code: SPT) (available at www.ign.es and www.intermagnet.org) with deviations lower than 40 nT. These deviations were attributed to several error factors as the different locations between MOURA and SPT and other possible different geomagnetic conditions. Due to the above, a measurement campaign on SPT installations are been done. The main objective is to compare MOURA measurements on a relevant environment, with data

  9. Brand name and generic proton pump inhibitor prescriptions in the United States: insights from the national ambulatory medical care survey (2006-2010).

    Science.gov (United States)

    Gawron, Andrew J; Feinglass, Joseph; Pandolfino, John E; Tan, Bruce K; Bove, Michiel J; Shintani-Smith, Stephanie

    2015-01-01

    Introduction. Proton pump inhibitors (PPI) are one of the most commonly prescribed medication classes with similar efficacy between brand name and generic PPI formulations. Aims. We determined demographic, clinical, and practice characteristics associated with brand name PPI prescriptions at ambulatory care visits in the United States. Methods. Observational cross sectional analysis using the National Ambulatory Medical Care Survey (NAMCS) of all adult (≥18 yrs of age) ambulatory care visits from 2006 to 2010. PPI prescriptions were identified by using the drug entry code as brand name only or generic available formulations. Descriptive statistics were reported in terms of unweighted patient visits and proportions of encounters with brand name PPI prescriptions. Global chi-square tests were used to compare visits with brand name PPI prescriptions versus generic PPI prescriptions for each measure. Poisson regression was used to determine the incidence rate ratio (IRR) for generic versus brand PPI prescribing. Results. A PPI was prescribed at 269.7 million adult ambulatory visits, based on 9,677 unweighted visits, of which 53% were brand name only prescriptions. In 2006, 76.0% of all PPI prescriptions had a brand name only formulation compared to 31.6% of PPI prescriptions in 2010. Visits by patients aged 25-44 years had the greatest proportion of brand name PPI formulations (57.9%). Academic medical centers and physician-owned practices had the greatest proportion of visits with brand name PPI prescriptions (58.9% and 55.6% of visits with a PPI prescription, resp.). There were no significant differences in terms of median income, patient insurance type, or metropolitan status when comparing the proportion of visits with brand name versus generic PPI prescriptions. Poisson regression results showed that practice ownership type was most strongly associated with the likelihood of receiving a brand name PPI over the entire study period. Compared to HMO visits

  10. Development of Magnetometer Digital Circuit for KSR-3 Rocket and Analytical Study on Calibration Result

    Directory of Open Access Journals (Sweden)

    Eun-Seok Lee

    2002-12-01

    Full Text Available This paper describes the re-design and the calibration results of the MAG digital circuit onboard the KSR-3. We enhanced the sampling rate of magnetometer data. Also, we reduced noise and increased authoritativeness of data. We could confirm that AIM resolution was decreased less than 1nT of analog calibration by a digital calibration of magnetometer. Therefore, we used numerical-program to correct this problem. As a result, we could calculate correction and error of data. These corrections will be applied to magnetometer data after the launch of KSR-3.

  11. Radiotherapy : proton therapy

    International Nuclear Information System (INIS)

    1991-01-01

    The first phase of proton therapy at the National Accelerator Centre will be the development of a 200 MeV small-field horizontal beam radioneurosurgical facility in the south treatment vault. A progressive expansion of this facility is planned. The patient support and positioning system has been designed and developed by the Departments of Mechanical Engineering and Surveying of the University of Cape Town to ensure the accurate positioning in the proton beam of the lesion to be treated. The basic components of the system are an adjustable chair, a series of video cameras and two computers. The specifications for the proton therapy interlock system require that the inputs to and the outputs from the system be similar to those of the neutron therapy system. Additional facilities such as a full diagnostic system which would assist the operators in the event of an error will also be provided. Dosimeters are required for beam monitoring, for monitor calibration and for determining dose distributions. Several designs of transmission ionization chambers for beam monitoring have been designed and tested, while several types of ionization chambers and diodes have been used for the dose distribution measurements. To facilitate the comparison of measured ranges and energy losses of proton beams in the various materials with tabled values, simple empirical approximations, which are sufficiently accurate for most applications, have been used. 10 refs., 10 fig., 4 tabs

  12. Proton decay theory

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1983-01-01

    Topics include minimal SU(5) predictions, gauge boson mediated proton decay, uncertainties in tau/sub p/, Higgs scalar effects, proton decay via Higgs scalars, supersymmetric SU(5), dimension 5 operators and proton decay, and Higgs scalars and proton decay

  13. Proton therapy

    International Nuclear Information System (INIS)

    Jongen, Y.

    1995-01-01

    Ideal radiotherapy deposits a large amount of energy in the tumour volume, and none in the surrounding healthy tissues. Proton therapy comes closer to this goal because of a greater concentration of dose, well defined proton ranges and points of energy release which are precisely known - the Bragg peak1. In the past, the development of clinical proton therapy has been hampered by complexity, size, and cost. To be clinically effective, energies of several hundred MeV are required; these were previously unavailable for hospital installations, and pioneering institutions had to work with complex, inadequate equipment originally intended for nuclear physics research. Recently a number of specialist organizations and commercial companies have been working on dedicated systems for proton therapy. One, IBA of Belgium, has equipment for inhouse hospital operation which encompasses a complete therapy centre, delivered as a turnkey package and incorporating a compact, automated, higher energy cyclotron with isocentric gantries. Their system will be installed at Massachusetts General Hospital, Boston. The proton therapy system comprises: - a 235 MeV isochronous cyclotron to deliver beams of up to 1.5 microamps, but with a hardware limitation to restrict the maximum possible dose; - variable energy beam (235 to 70 MeV ) with energy spread and emittance verification; - a beam transport and switching system to connect the exit of the energy selection system to the entrances of a number of gantries and fixed beamlines. Along the beam transport system, the beam characteristics are monitored with non-interceptive multiwire ionization chambers for automatic tuning; - gantries fitted with nozzles and beamline elements for beam control; both beam scattering and beam wobbling techniques are available for shaping the beam;

  14. Aerial gamma ray and magnetic survey, Van Horn and Pecos Quadrangles, Texas. Volume I. Final report

    International Nuclear Information System (INIS)

    1977-10-01

    A high sensitivity, airborne radiometric and magnetic survey of portions of the Big Bend, Texas area was conducted. The project area comprising the Van Horn and Pecos 1:250,000 NTMS sheets, consists of approximately 16,400 square miles. A total of 6,666 line miles of high sensitivity radiometric and magnetic data were collected. Traverse lines were flown at a spacing of 3.125 miles in an east/west direction with tie lines flown in a north/south direction at a 18.375 miles separation. All data were collected utilizing a fixed wing aircraft, Grumman G-89 and over 3,500 cubic inches of NaI crystal detector. Magnetometer data were collected utilizing a high sensitivity, 0.25 gamma, proton magnetometer. Data were digitally recorded at 0.5 second intervals. All field data were returned to the computer facilities for processing, statistical analysis, and interpretation. Other data are presented which include corrected profiles of all radiometric variables, magnetic data, radar altimeter data, barometric altimeter data, air temperature and airborne Bismuth contributions. Data presented have been summed to provide 1.0 second equivalent sample intervals, corrected for Compton Scatter, altitude dependence and atmospheric Bismuth. These data are presented in the form of strip charts, microfiche, and digital magnetic tapes containing raw spectral data, single record data, magnetic data, and statistical analysis results. In addition, computer generated anomaly maps along with interpretation maps are presented relating mapped geology to the collected radiometric data

  15. Rad-Hard Sigma-Delta 3-Channel ADC for Fluxgate Magnetometers, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The measurement of the magnetic field vector is of fundamental importance to space physics missions. The fluxgate magnetometer is a device developed for precise...

  16. Measuring In-Flight Angular Motion With a Low-Cost Magnetometer

    National Research Council Canada - National Science Library

    Harkins, Thomas E; Wilson, Michael J

    2007-01-01

    A technique for obtaining pitch, yaw, and roll rates of a projectile from a single, low-cost, commercial off-the-shelf magnetometer has been developed at the Advanced Munitions Concepts Branch of the U.S...

  17. Rad-Hard Sigma-Delta 3-channel ADC for Fluxgate Magnetometers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project aims to develop a multi-channel analog to digital converter (ADC) required for a fluxgate magnetometer (EPD) employed on NASA's planetary...

  18. Simplified High-Performance Roll Out Composite Magnetometer Boom, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to NASA's need for compact, low-cost deployable magnetometer booms for CubeSats, Roccor proposes to develop a Simple High-performance Roll-Out Composite...

  19. Basic technical parameters of magnetometers with ferromagnetic transducers and a method to define them

    International Nuclear Information System (INIS)

    Nagiello, Z.

    1980-01-01

    The basic technical parameters of magnetometers with ferromagnetic transducers and measuring methods to define these parameters have been discussed. Special attention was paid to factors which essentially affect the inaccuracy of these measuring instruments. (author)

  20. Venus Lightning: What We Have Learned from the Venus Express Fluxgate Magnetometer

    Science.gov (United States)

    Russell, C. T.; Strangeway, R. J.; Wei, H. Y.; Zhang, T. L.

    2010-03-01

    The Venus Express magnetometer sees short (tens of milliseconds) pulses of EM waves in the Venus ionosphere as predicted by the lightning model for the PVO electric pulses. These waves are stronger than similar terrestrial signals produced by lightning.

  1. Sensitivity optimization of Bell-Bloom magnetometers by manipulation of atomic spin synchronization

    Science.gov (United States)

    Ranjbaran, M.; Tehranchi, M. M.; Hamidi, S. M.; Khalkhali, S. M. H.

    2018-05-01

    Many efforts have been devoted to the developments of atomic magnetometers for achieving the high sensitivity required in biomagnetic applications. To reach the high sensitivity, many types of atomic magnetometers have been introduced for optimization of the creation and relaxation rates of atomic spin polarization. In this paper, regards to sensitivity optimization techniques in the Mx configuration, we have proposed a novelty approach for synchronization of the spin precession in the Bell-Bloom magnetometers. We have utilized the phenomenological Bloch equations to simulate the spin dynamics when modulation of pumping light and radio frequency magnetic field were both used for atomic spin synchronization. Our results showed that the synchronization process, improved the magnetometer sensitivity respect to the classical configurations.

  2. IceBridge Scintrex CS-3 Cesium Magnetometer L1B Geolocated Magnetic Anomalies, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Scintrex CS-3 Cesium Magnetometer L1B Geolocated Magnetic Anomalies (IMCS31B) data set contains magnetic field readings taken over Greenland using...

  3. IceBridge Scintrex CS-3 Cesium Magnetometer L0 Raw Magnetic Field, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Scintrex CS-3 Cesium Magnetometer L0 Raw Magnetic Field data set contains magnetic field readings and fluxgate values taken over Greenland using...

  4. Feasibility study on measurement of magnetocardiography (MCG) using fluxgate magnetometer

    Science.gov (United States)

    Sengottuvel, S.; Sharma, Akash; Biswal, Deepak; Khan, Pathan Fayaz; Swain, Pragyna Parimita; Patel, Rajesh; Gireesan, K.

    2018-04-01

    This paper reports the feasibility of measuring weak magnetic fields generated by the electrical activity of the heart using a portable tri-axial fluxgate magnetometer inside a magnetically shielded room. Measurement of Magnetocardiogram (MCG) signals could be successfully demonstrated from a healthy subject using a novel set-up involving a reference fluxgate sensor which simultaneously measures the magnetic fields associated with the ECG waveform measured on the same subject. The timing information provided by R wave peaks of ECG recorded by the reference sensor is utilized to generate trigger locked average of the sensor output of the measurement fluxgate, and extract MCG signals in all the three orthogonal directions (X, Y and Z) on the anterior thorax. It is expected that such portable room temperature measurements using fluxgate sensor could assist in validating the direction of the equivalent current dipole associated with the electrical activity of the human heart. This is somewhat difficult in conventional MCG measurements using SQUID sensors, which usually furnish only the z component of the magnetic field and its spatial derivatives.

  5. CLUSTER STAFF search coils magnetometer calibration - comparisons with FGM

    Science.gov (United States)

    Robert, P.; Cornilleau-Wehrlin, N.; Piberne, R.; de Conchy, Y.; Lacombe, C.; Bouzid, V.; Grison, B.; Alison, D.; Canu, P.

    2013-12-01

    The main part of Cluster Spatio Temporal Analysis of Field Fluctuations (STAFF) experiment consists of triaxial search coils allowing the measurements of the three magnetic components of the waves from 0.1 Hz up to 4 kHz. Two sets of data are produced, one by a module to filter and transmit the corresponding waveform up to either 10 or 180 Hz (STAFF-SC) and the second by an onboard Spectrum Analyser (STAFF-SA) to compute the elements of the spectral matrix for five components of the waves, 3 × B and 2 × E (from EFW experiment) in the frequency range 8 Hz to 4 kHz. In order to understand the way the output signal of the search coils are calibrated, the transfer functions of the different parts of the instrument are described as well as the way to transform telemetry data into physical units, across various coordinate systems from the spinning sensors to a fixed and known frame. The instrument sensitivity is discussed. Cross-calibration inside STAFF (SC and SA) is presented. Results of cross-calibration between the STAFF search coils and the Cluster Flux Gate Magnetometer (FGM) data are discussed. It is shown that these cross-calibrations lead to an agreement between both data sets at low frequency within a 2% error. By means of statistics done over 10 yr, it is shown that the functionalities and characteristics of both instruments have not changed during this period.

  6. CLUSTER-STAFF search coil magnetometer calibration - comparisons with FGM

    Science.gov (United States)

    Robert, P.; Cornilleau-Wehrlin, N.; Piberne, R.; de Conchy, Y.; Lacombe, C.; Bouzid, V.; Grison, B.; Alison, D.; Canu, P.

    2014-09-01

    The main part of the Cluster Spatio-Temporal Analysis of Field Fluctuations (STAFF) experiment consists of triaxial search coils allowing the measurements of the three magnetic components of the waves from 0.1 Hz up to 4 kHz. Two sets of data are produced, one by a module to filter and transmit the corresponding waveform up to either 10 or 180 Hz (STAFF-SC), and the second by the onboard Spectrum Analyser (STAFF-SA) to compute the elements of the spectral matrix for five components of the waves, 3 × B and 2 × E (from the EFW experiment), in the frequency range 8 Hz to 4 kHz. In order to understand the way the output signals of the search coils are calibrated, the transfer functions of the different parts of the instrument are described as well as the way to transform telemetry data into physical units across various coordinate systems from the spinning sensors to a fixed and known frame. The instrument sensitivity is discussed. Cross-calibration inside STAFF (SC and SA) is presented. Results of cross-calibration between the STAFF search coils and the Cluster Fluxgate Magnetometer (FGM) data are discussed. It is shown that these cross-calibrations lead to an agreement between both data sets at low frequency within a 2% error. By means of statistics done over 10 yr, it is shown that the functionalities and characteristics of both instruments have not changed during this period.

  7. A xylophone bar magnetometer for micro/pico satellites

    Science.gov (United States)

    Lamy, Hervé; Niyonzima, Innocent; Rochus, Pierre; Rochus, Véronique

    2010-10-01

    The Belgian Institute of Space Aeronomy (BIRA-IASB), "Centre Spatial de Liège" (CSL), "Laboratoire de Techniques Aéronautiques et Spatiales" (LTAS) of University of Liège, and the Microwave Laboratory of University of Louvain-La-Neuve (UCL) are collaborating in order to develop a miniature version of a xylophone bar magnetometer (XBM) using Microelectromechanical Systems (MEMS) technology. The device is based on a classical resonating xylophone bar. A sinusoidal current is supplied to the bar oscillating at the fundamental transverse resonant mode of the bar. When an external magnetic field is present, the resulting Lorentz force causes the bar to vibrate at its fundamental frequency with an amplitude directly proportional to the vertical component of the ambient magnetic field. In this paper we illustrate the working principles of the XBM and the challenges to reach the required sensitivity in space applications (measuring magnetic fields with an accuracy of approximately of 0.1 nT). The optimal dimensions of the MEMS XBM are discussed as well as the constraints on the current flowing through the bar. Analytical calculations as well as simulations with finite element methods have been used. Prototypes have been built in the Microwave Laboratory using silicon on insulator (SOI) and bulk micromachining processes. Several methods to accurately measure the displacement of the bar are proposed.

  8. Reducing systematic errors in measurements made by a SQUID magnetometer

    International Nuclear Information System (INIS)

    Kiss, L.F.; Kaptás, D.; Balogh, J.

    2014-01-01

    A simple method is described which reduces those systematic errors of a superconducting quantum interference device (SQUID) magnetometer that arise from possible radial displacements of the sample in the second-order gradiometer superconducting pickup coil. By rotating the sample rod (and hence the sample) around its axis into a position where the best fit is obtained to the output voltage of the SQUID as the sample is moved through the pickup coil, the accuracy of measuring magnetic moments can be increased significantly. In the cases of an examined Co 1.9 Fe 1.1 Si Heusler alloy, pure iron and nickel samples, the accuracy could be increased over the value given in the specification of the device. The suggested method is only meaningful if the measurement uncertainty is dominated by systematic errors – radial displacement in particular – and not by instrumental or environmental noise. - Highlights: • A simple method is described which reduces systematic errors of a SQUID. • The errors arise from a radial displacement of the sample in the gradiometer coil. • The procedure is to rotate the sample rod (with the sample) around its axis. • The best fit to the SQUID voltage has to be attained moving the sample through the coil. • The accuracy of measuring magnetic moment can be increased significantly

  9. Obtaining 'images' from iron objects using a 3-axis fluxgate magnetometer

    International Nuclear Information System (INIS)

    Chilo, Jose; Jabor, Abbas; Lizska, Ludwik; Eide, Age J.; Lindblad, Thomas

    2007-01-01

    Magnetic objects can cause local variations in the Earth's magnetic field that can be measured with a magnetometer. Here we used tri-axial magnetometer measurements and an analysis method employing wavelet techniques to determine the 'signature' or 'fingerprint' of different iron objects. Clear distinctions among the iron samples were observed. The time-dependent changes in the frequency powers were extracted by use of the Morlet wavelet corresponding to frequency bands from 0.1 to 100 Hz

  10. High-sensitivity dc field magnetometer using nonlinear resonance magnetoelectric effect

    International Nuclear Information System (INIS)

    Burdin, D.A.; Chashin, D.V.; Ekonomov, N.A.; Fetisov, Y.K.; Stashkevich, A.A.

    2016-01-01

    The design and operation principle of dc field magnetometer using nonlinear resonance magnetoelectric effect in a ferromagnetic–piezoelectric structure are described. It is shown that under action of ac pumping magnetic field the structure generates the output voltage containing higher harmonics whose amplitudes depend on the dc magnetic field. Best performance of the device is obtained if the signal of the third harmonics is used for the dc field measurement. The sensitivity can be considerably (by approximately three orders of magnitude) increased if advantage is taken of the acoustic resonance of the structure at this frequency. There exists the optimal pumping field ensuring the highest sensitivity. Further increasing of this field expands the range of measurable dc fields at the expense of deteriorated sensitivity. The magnetometer fabricated on the basis of a planar langatate-Metglas structure had sensitivity up to ~1 V/Oe and allowed detection of the fields as low as ~10"−"5 Oe. - Highlights: • Operational principle and design of new type dc field magnetometer is described. • Magnetometer uses nonlinear magnetoelectric effect in a langatate-Metglas structure. • Magnetometer has sensitivity of ~1 V/Oe and detects fields as low as 10"−"5 Oe. • The proposed magnetometer can compete with well known fluxgate sensors.

  11. High-sensitivity dc field magnetometer using nonlinear resonance magnetoelectric effect

    Energy Technology Data Exchange (ETDEWEB)

    Burdin, D.A.; Chashin, D.V.; Ekonomov, N.A. [Moscow State University of Information Technologies, Radio Engineering and Electronics, Moscow (Russian Federation); Fetisov, Y.K., E-mail: fetisov@mirea.ru [Moscow State University of Information Technologies, Radio Engineering and Electronics, Moscow (Russian Federation); Stashkevich, A.A. [LSPM (CNRS-UPR 3407), Université Paris 13, Sorbonne Paris Cité, 93430 Villetaneuse (France)

    2016-05-01

    The design and operation principle of dc field magnetometer using nonlinear resonance magnetoelectric effect in a ferromagnetic–piezoelectric structure are described. It is shown that under action of ac pumping magnetic field the structure generates the output voltage containing higher harmonics whose amplitudes depend on the dc magnetic field. Best performance of the device is obtained if the signal of the third harmonics is used for the dc field measurement. The sensitivity can be considerably (by approximately three orders of magnitude) increased if advantage is taken of the acoustic resonance of the structure at this frequency. There exists the optimal pumping field ensuring the highest sensitivity. Further increasing of this field expands the range of measurable dc fields at the expense of deteriorated sensitivity. The magnetometer fabricated on the basis of a planar langatate-Metglas structure had sensitivity up to ~1 V/Oe and allowed detection of the fields as low as ~10{sup −5} Oe. - Highlights: • Operational principle and design of new type dc field magnetometer is described. • Magnetometer uses nonlinear magnetoelectric effect in a langatate-Metglas structure. • Magnetometer has sensitivity of ~1 V/Oe and detects fields as low as 10{sup −5} Oe. • The proposed magnetometer can compete with well known fluxgate sensors.

  12. A portable Hall magnetometer probe for characterization of magnetic iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Jefferson F.D.F.; Costa, Mateus C.; Louro, Sonia R.W.; Bruno, Antonio C., E-mail: acbruno@puc-rio.br

    2017-03-15

    We have built a portable Hall magnetometer probe, for measuring magnetic properties of iron oxide nanoparticles, that can be used for bulk materials and liquid samples as well. The magnetometer probe consists of four voltage-programmable commercial Hall sensors and a thin acrylic plate for positioning the sensors. In order to operate, it needs to be attached to a pole of an electromagnet and connected to an AD converter and a computer. It acquires a complete magnetization curve in a couple of minutes and has a magnetic moment sensitivity of 3.5×10{sup −7} Am{sup 2}. We tested its performance with magnetic nanoparticles containing an iron oxide core and having coating layers with different sizes. The magnetization results obtained were compared with measurements performed on commercial stand-alone magnetometers, and exhibited errors of about ±0.2 Am{sup 2}/kg (i.e 0.4%) at saturation and below 0.5 Am{sup 2}/kg (i.e. 10%) at remanence. - Highlights: • A low-cost portable Hall magnetometer probe has been built. • The Hall magnetometer probe can be attached to any electromagnet. • The Hall probe was calibrated and successfully compared to industry standard magnetometers. • The Hall probe was able to measure iron oxide nanoparticles with different coatings.

  13. A portable Hall magnetometer probe for characterization of magnetic iron oxide nanoparticles

    International Nuclear Information System (INIS)

    Araujo, Jefferson F.D.F.; Costa, Mateus C.; Louro, Sonia R.W.; Bruno, Antonio C.

    2017-01-01

    We have built a portable Hall magnetometer probe, for measuring magnetic properties of iron oxide nanoparticles, that can be used for bulk materials and liquid samples as well. The magnetometer probe consists of four voltage-programmable commercial Hall sensors and a thin acrylic plate for positioning the sensors. In order to operate, it needs to be attached to a pole of an electromagnet and connected to an AD converter and a computer. It acquires a complete magnetization curve in a couple of minutes and has a magnetic moment sensitivity of 3.5×10 −7 Am 2 . We tested its performance with magnetic nanoparticles containing an iron oxide core and having coating layers with different sizes. The magnetization results obtained were compared with measurements performed on commercial stand-alone magnetometers, and exhibited errors of about ±0.2 Am 2 /kg (i.e 0.4%) at saturation and below 0.5 Am 2 /kg (i.e. 10%) at remanence. - Highlights: • A low-cost portable Hall magnetometer probe has been built. • The Hall magnetometer probe can be attached to any electromagnet. • The Hall probe was calibrated and successfully compared to industry standard magnetometers. • The Hall probe was able to measure iron oxide nanoparticles with different coatings.

  14. Proton radiography to improve proton therapy treatment

    NARCIS (Netherlands)

    Takatsu, J.; van der Graaf, E. R.; van Goethem, Marc-Jan; van Beuzekom, M.; Klaver, T.; Visser, Jan; Brandenburg, S.; Biegun, A. K.

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT)

  15. In-Flight Calibration of the MMS Fluxgate Magnetometers

    Science.gov (United States)

    Bromund, K. R.; Plaschke, F.; Strangeway, R. J.; Anderson, B. J.; Huang, B. G.; Magnes, W.; Fischer, D.; Nakamura, R.; Leinweber, H. K.; Russell, C. T.; hide

    2017-01-01

    We present an overview of the approach to in-flight calibration, which is a coordinated effort between the University of California Los Angeles (UCLA), Space Research Institute, Graz, Austria (IWF) and the NASA Goddard Space Flight Center (GSFC). We present details of the calibration effort at GSFC. During the first dayside season of the Magnetospheric Multiscale (MMS) mission, the in-flight calibration process for the Fluxgate magnetometers (FGM) implemented an algorithm that selected a constant offset (zero-level) for each sensor on each orbit. This method was generally able to reduce the amplitude of residual spin tone to less than 0.2 nT within the region of interest. However, there are times when the offsets do show significant short-term variations. These variations are most prominent in the nighttime season (phase 1X), when eclipses are accompanied by offset changes as large as 1 nT. Eclipses are followed by a recovery period as long as 12 hours where the offsets continue to change as temperatures stabilize. Understanding and compensating for these changes will become critical during Phase 2 of the mission in 2017, when the nightside will become the focus of MMS science. Although there is no direct correlation between offset and temperature, the offsets are seen for the period of any given week to be well-characterized as function of instrument temperature. Using this property, a new calibration method has been developed that has proven effective in compensating for temperature-dependent offsets during phase 1X of the MMS mission and also promises to further refine calibration quality during the dayside season.

  16. In honour of N. Yngve Öhrn: surveying proton cancer therapy reactions with Öhrn's electron nuclear dynamics method. Aqueous clusters radiolysis and DNA-base damage by proton collisions

    Science.gov (United States)

    Mclaurin, Patrick M.; Privett, Austin J.; Stopera, Christopher; Grimes, Thomas V.; Perera, Ajith; Morales, Jorge A.

    2015-02-01

    Proton cancer therapy (PCT) utilises high-energy H+ projectiles to cure cancer. PCT healing arises from its DNA damage in cancerous cells, which is mostly inflicted by the products from PCT water radiolysis reactions. While clinically established, a complete microscopic understanding of PCT remains elusive. To help in the microscopic elucidation of PCT, Professor Öhrn's simplest-level electron nuclear dynamics (SLEND) method is herein applied to H+ + (H2O)3-4 and H+ + DNA-bases at ELab = 1.0 keV. These are two types of computationally feasible prototypes to study water radiolysis reactions and H+-induced DNA damage, respectively. SLEND is a time-dependent, variational, non-adiabatic and direct-dynamics method that adopts a nuclear classical-mechanics description and an electronic single-determinantal wavefunction. Additionally, our SLEND + effective-core-potential method is herein employed to simulate some computationally demanding PCT reactions. Due to these attributes, SLEND proves appropriate for the simulation of various types of PCT reactions accurately and feasibly. H+ + (H2O)3-4 simulations reveal two main processes: H+ projectile scattering and the simultaneous formation of H and OH fragments; the latter process is quantified through total integrals cross sections. H+ + DNA-base simulations reveal atoms and groups displacements, ring openings and base-to-proton electron transfers as predominant damage processes. The authors warmly dedicate this SLEND investigation in honour of Professor N. Yngve Öhrn on the occasion of his 80th birthday celebration during the 54th Sanibel Symposium in St. Simons' Island, Georgia, on February 16-21, 2014. Associate Professor Jorge A. Morales was a former chemistry PhD student under the mentorship of Professor Öhrn and Dr Ajith Perera took various quantum chemistry courses taught by Professor Öhrn during his chemistry PhD studies. Both Jorge and Ajith look back to those great times of their scientific formation under

  17. Plasma flow during the brightening of proton aurora in the cusp

    DEFF Research Database (Denmark)

    Taguchi, S.; Hosokawa, K.; Suzuki, S.

    2010-01-01

    On the basis of simultaneous observations from the Super Dual Auroral Radar Network (SuperDARN), the far ultraviolet instrument on the IMAGE spacecraft, and a magnetometer installed on the east coast of Greenland, we present the characteristics of plasma flow during a westward moving proton auror...... to the traveling bulge at the polar cap boundary, which is the footprint of a flux transfer event, and imply that the preexisting vortical flow may be intensified when it becomes inflow to the bulge....

  18. Radiation tolerance of a spin-dependent tunnelling magnetometer for space applications

    International Nuclear Information System (INIS)

    Persson, Anders; Thornell, Greger; Nguyen, Hugo

    2011-01-01

    To meet the increasing demand for miniaturized space instruments, efforts have been made to miniaturize traditional magnetometers, e.g. fluxgate and spin-exchange relaxation-free magnetometers. These have, for different reasons, turned out to be difficult. New technologies are needed, and promising in this respect are tunnelling magnetoresistive (TMR) magnetometers, which are based on thin film technology. However, all new space devices first have to be qualified, particularly in terms of radiation resistance. A study on TMR magnetometers' vulnerability to radiation is crucial, considering the fact that they employ a dielectric barrier, which can be susceptible to charge trapping from ionizing radiation. Here, a TMR-based magnetometer, called the spin-dependent tunnelling magnetometer (SDTM), is presented. A magnetometer chip consisting of three Wheatstone bridges, with an angular pitch of 120°, was fabricated using microstructure technology. Each branch of the Wheatstone bridges consists of eight pairs of magnetic tunnel junctions (MTJs) connected in series. Two such chips are used to measure the three-dimensional magnetic field vector. To investigate the SDTM's resistance to radiation, one branch of a Wheatstone bridge was irradiated with gamma rays from a Co 60 source with a dose rate of 10.9 rad min −1 to a total dose of 100 krad. The TMR of the branch was monitored in situ, and the easy axis TMR loop and low-frequency noise characteristics of a single MTJ were acquired before and after irradiation with the total dose. It was concluded that radiation did not influence the MTJs in any noticeable way in terms of the TMR ratio, coercivity, magnetostatic coupling or low-frequency noise

  19. Proton diffraction

    International Nuclear Information System (INIS)

    Den Besten, J.L.; Jamieson, D.N.; Allen, L.J.

    1998-01-01

    The Lindhard theory on ion channeling in crystals has been widely accepted throughout ion beam analysis for use in simulating such experiments. The simulations use a Monte Carlo method developed by Barret, which utilises the classical 'billiard ball' theory of ions 'bouncing' between planes or tubes of atoms in the crystal. This theory is not valid for 'thin' crystals where the planes or strings of atoms can no longer be assumed to be of infinite proportions. We propose that a theory similar to that used for high energy electron diffraction can be applied to MeV ions, especially protons, in thin crystals to simulate the intensities of transmission channeling and of RBS spectra. The diffraction theory is based on a Bloch wave solution of the Schroedinger equation for an ion passing through the periodic crystal potential. The widely used universal potential for proton-nucleus scattering is used to construct the crystal potential. Absorption due to thermal diffuse scattering is included. Experimental parameters such as convergence angle, beam tilt and scanning directions are considered in our calculations. Comparison between theory and experiment is encouraging and suggests that further work is justified. (authors)

  20. Nonlinear temperature compensation of fluxgate magnetometers with a least-squares support vector machine

    International Nuclear Information System (INIS)

    Pang, Hongfeng; Chen, Dixiang; Pan, Mengchun; Luo, Shitu; Zhang, Qi; Luo, Feilu

    2012-01-01

    Fluxgate magnetometers are widely used for magnetic field measurement. However, their accuracy is influenced by temperature. In this paper, a new method was proposed to compensate the temperature drift of fluxgate magnetometers, in which a least-squares support vector machine (LSSVM) is utilized. The compensation performance was analyzed by simulation, which shows that the LSSVM has better performance and less training time than backpropagation and radical basis function neural networks. The temperature characteristics of a DM fluxgate magnetometer were measured with a temperature experiment box. Forty-five measured data under different magnetic fields and temperatures were obtained and divided into 36 training data and nine test data. The training data were used to obtain the parameters of the LSSVM model, and the compensation performance of the LSSVM model was verified by the test data. Experimental results show that the temperature drift of magnetometer is reduced from 109.3 to 3.3 nT after compensation, which suggests that this compensation method is effective for the accuracy improvement of fluxgate magnetometers. (paper)

  1. A dumbbell-shaped hybrid magnetometer operating in DC-10 kHz

    Science.gov (United States)

    Shi, Hongyu; Wang, Yanzhang; Chen, Siyu; Lin, Jun

    2017-12-01

    This study is motivated by the need to design a hybrid magnetometer operating in a wide-frequency band from DC to 10 kHz. To achieve this objective, a residence times difference fluxgate magnetometer (RTDFM) and an induction magnetometer (IM) have been integrated into a compact form. The hybrid magnetometer has a dumbbell-shaped structure in which the RTDFM transducer is partially inserted into the tube cores of the IM. Thus, the sensitivity of the RTDFM is significantly improved due to the flux amplification. The optimal structure, which has maximum sensitivity enhancement, was obtained through FEM analysis. To validate the theoretical analysis, the optimal hybrid magnetometer was manufactured, and its performance was evaluated. The device has a sensitivity of 45 mV/nT at 1 kHz in IM mode and 0.38 μs/nT in RTDFM mode, which is approximately 3.45 times as large as that of the single RTDFM structure. Furthermore, to obtain a lower noise performance in the entire frequency band, two operation modes switch at the cross frequency (0.16 Hz) of their noise levels. The noise level is 30 pT/√Hz in RTDFM mode and 0.07 pT/√Hz at 1 kHz in IM mode.

  2. Nonlinear temperature compensation of fluxgate magnetometers with a least-squares support vector machine

    Science.gov (United States)

    Pang, Hongfeng; Chen, Dixiang; Pan, Mengchun; Luo, Shitu; Zhang, Qi; Luo, Feilu

    2012-02-01

    Fluxgate magnetometers are widely used for magnetic field measurement. However, their accuracy is influenced by temperature. In this paper, a new method was proposed to compensate the temperature drift of fluxgate magnetometers, in which a least-squares support vector machine (LSSVM) is utilized. The compensation performance was analyzed by simulation, which shows that the LSSVM has better performance and less training time than backpropagation and radical basis function neural networks. The temperature characteristics of a DM fluxgate magnetometer were measured with a temperature experiment box. Forty-five measured data under different magnetic fields and temperatures were obtained and divided into 36 training data and nine test data. The training data were used to obtain the parameters of the LSSVM model, and the compensation performance of the LSSVM model was verified by the test data. Experimental results show that the temperature drift of magnetometer is reduced from 109.3 to 3.3 nT after compensation, which suggests that this compensation method is effective for the accuracy improvement of fluxgate magnetometers.

  3. NetPICOmag: A low-cost networked magnetometer and its applications

    Science.gov (United States)

    Schofield, I.; Connors, M.; Russell, C. T.

    2012-03-01

    NetPICOmag (NPM) is the culmination of a design effort to build a compact, low-cost, laboratory-grade, networked magnetometer designed for remote autonomous operation, suited for research and education. NPM allows wide placement of magnetometers sensitive enough to detect auroral activity and the daily variation, and is suitable for education projects and a range of geophysical applications. The use of networked microcontrollers and GPS timing is applicable to other small instruments for field or local deployment, and an onboard data logging capability has also been demonstrated. We illustrate the value of the placement of low-cost magnetometers to increase coverage in an area through the study of a Pc 5 pulsation event which took place on September 4, 2010. By combining results with those from auroral zone magnetometers supporting the THEMIS project, we find that the phase velocity of these morning sector pulsations was northward on the ground. The event took place under very quiet solar wind conditions, and credible mapping associates it with the inner magnetosphere. Another aspect beyond increasing areal coverage is increasing density of coverage, which becomes feasible with instruments of very low cost. We examine aspects of the April 5, 2010 space weather event which are possible to deduce from closely spaced magnetometers.

  4. Proton imaging apparatus for proton therapy application

    International Nuclear Information System (INIS)

    Sipala, V.; Lo Presti, D.; Brianzi, M.; Civinini, C.; Bruzzi, M.; Scaringella, M.; Talamonti, C.; Bucciolini, M.; Cirrone, G.A.P.; Cuttone, G.; Randazzo, N.; Stancampiano, C.; Tesi, M.

    2011-01-01

    Radiotherapy with protons, due to the physical properties of these particles, offers several advantages for cancer therapy as compared to the traditional radiotherapy and photons. In the clinical use of proton beams, a p CT (Proton Computer Tomography) apparatus can contribute to improve the accuracy of the patient positioning and dose distribution calculation. In this paper a p CT apparatus built by the Prima (Proton Imaging) Italian Collaboration will be presented and the preliminary results will be discussed.

  5. Proton radioactivity from proton-rich nuclei

    International Nuclear Information System (INIS)

    Guzman, F.; Goncalves, M.; Tavares, O.A.P.; Duarte, S.B.; Garcia, F.; Rodriguez, O.

    1999-03-01

    Half-lives for proton emission from proton-rich nuclei have been calculated by using the effective liquid drop model of heavy-particle decay of nuclei. It is shown that this model is able to offer results or spontaneous proton-emission half-life-values in excellent agreement with the existing experimental data. Predictions of half-life-values for other possible proton-emission cases are present for null orbital angular momentum. (author)

  6. Comparison of a triaxial fluxgate magnetometer and Toftness sensometer for body surface EMF measurement.

    Science.gov (United States)

    Zhang, John; Toftness, Dave; Snyder, Brian; Nosco, Dennis; Balcavage, Walter; Nindl, Gabi

    2004-12-01

    The use of magnetic fields to treat disease has intrigued mankind since the time of the ancient Greeks. More recently it has been shown that electromagnetic field (EMF) treatment aids bone healing, and repetitive transcranial magnetic stimulation (rTMS) appears to be beneficial in treating schizophrenia and depression. Since external EMFs influence internal body processes, we hypothesized that measurement of body surface EMFs might be used to detect disease states and direct the course of subsequent therapy. However, measurement of minute body surface EMFs requires use of a sensitive and well documented magnetometer. In this study we evaluated the sensitivity and frequency response of a fluxgate magnetometer with a triaxial probe for use in detecting body surface EMF and we compared the magnetometer readings with a signal from a Toftness Sensometer, operated by an experienced clinician, in the laboratory and in a clinical setting. A Peavy Audio Amplifier and variable power output Telulex signal generator were used to develop 50 microT EMFs in a three coil Merritt coil system. A calibrated magnetometer was used to set a 60 Hz 50 microT field in the coil and an ammeter was used to measure the current required to develop the 50 microT field. At frequencies other than 60 Hz, the field strength was maintained at 50 microT by adjusting the Telulex signal output to keep the current constant. The field generated was monitored using a 10 turn coil connected to an oscilloscope. The oscilloscope reading indicated that the field strength was the same at all frequencies tested. To determine if there was a correspondence between the signals detected by a fluxgate magnetometer (FGM1) and the Toftness Sensometer both devices were placed in the Merritt coil and readings were recorded from the FGM1 and compared with the ability of a highly experienced Toftness operator to detect the 50 microT field. Subsequently, in a clinical setting, FGM1 readings made by an FGM1 technician and

  7. Construction and calibration of a low cost and fully automated vibrating sample magnetometer

    International Nuclear Information System (INIS)

    El-Alaily, T.M.; El-Nimr, M.K.; Saafan, S.A.; Kamel, M.M.; Meaz, T.M.; Assar, S.T.

    2015-01-01

    A low cost vibrating sample magnetometer (VSM) has been constructed by using an electromagnet and an audio loud speaker; where both are controlled by a data acquisition device. The constructed VSM records the magnetic hysteresis loop up to 8.3 KG at room temperature. The apparatus has been calibrated and tested by using magnetic hysteresis data of some ferrite samples measured by two scientifically calibrated magnetometers; model (Lake Shore 7410) and model (LDJ Electronics Inc. Troy, MI). Our VSM lab-built new design proved success and reliability. - Highlights: • A low cost automated vibrating sample magnetometer VSM has been constructed. • The VSM records the magnetic hysteresis loop up to 8.3 KG at room temperature. • The VSM has been calibrated and tested by using some measured ferrite samples. • Our VSM lab-built new design proved success and reliability

  8. Construction and calibration of a low cost and fully automated vibrating sample magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    El-Alaily, T.M., E-mail: toson_alaily@yahoo.com [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); El-Nimr, M.K.; Saafan, S.A.; Kamel, M.M.; Meaz, T.M. [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); Assar, S.T. [Engineering Physics and Mathematics Department, Faculty of Engineering, Tanta University, Tanta (Egypt)

    2015-07-15

    A low cost vibrating sample magnetometer (VSM) has been constructed by using an electromagnet and an audio loud speaker; where both are controlled by a data acquisition device. The constructed VSM records the magnetic hysteresis loop up to 8.3 KG at room temperature. The apparatus has been calibrated and tested by using magnetic hysteresis data of some ferrite samples measured by two scientifically calibrated magnetometers; model (Lake Shore 7410) and model (LDJ Electronics Inc. Troy, MI). Our VSM lab-built new design proved success and reliability. - Highlights: • A low cost automated vibrating sample magnetometer VSM has been constructed. • The VSM records the magnetic hysteresis loop up to 8.3 KG at room temperature. • The VSM has been calibrated and tested by using some measured ferrite samples. • Our VSM lab-built new design proved success and reliability.

  9. Field-Programmable Gate Array-based fluxgate magnetometer with digital integration

    Science.gov (United States)

    Butta, Mattia; Janosek, Michal; Ripka, Pavel

    2010-05-01

    In this paper, a digital magnetometer based on printed circuit board fluxgate is presented. The fluxgate is pulse excited and the signal is extracted by gate integration. We investigate the possibility to perform integration on very narrow gates (typically 500 ns) by using digital techniques. The magnetometer is based on field-programmable gate array (FPGA) card: we will show all the advantages and disadvantages, given by digitalization of fluxgate output voltage by means of analog-to-digital converter on FPGA card, as well as digitalization performed by external digitizer. Due to very narrow gate, it is shown that a magnetometer entirely based on a FPGA card is preferable, because it avoids noise due to trigger instability. Both open loop and feedback operative mode are described and achieved results are presented.

  10. Development of a {sup 3}He magnetometer for a neutron electric dipole moment experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, Andreas; Heil, Werner; Lauer, Thorsten; Neumann, Daniel [Johannes Gutenberg University, Institute of Physics, Mainz (Germany); Koch, Hans-Christian [Johannes Gutenberg University, Institute of Physics, Mainz (Germany); University of Fribourg, Physics Department, Fribourg (Switzerland); Daum, Manfred [Paul Scherrer Institute, Villigen (Switzerland); Pazgalev, Anatoly [Ioffe Institute, St Petersburg (Russian Federation); Sobolev, Yuri [Johannes Gutenberg University, Institute of Nuclear Chemistry, Mainz (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Weis, Antoine [University of Fribourg, Physics Department, Fribourg (Switzerland)

    2014-01-01

    We have developed a highly sensitive {sup 3}He magnetometer for the accurate measurement of the magnetic field in an experiment searching for an electric dipole moment of the neutron. By measuring the Larmor frequency of nuclear spin polarized {sup 3}He atoms a sensitivity on the femto-Tesla scale can be achieved. A {sup 3}He/Cs-test facility was established at the Institute of Physics of the Johannes Gutenberg University in Mainz to investigate the readout of {sup 3}He free induction decay with a lamp-pumped Cs magnetometer. For this we designed and built an ultra-compact and transportable polarizer unit which polarizes {sup 3}He gas up to 55% by metastability exchange optical pumping. The polarized {sup 3}He was successfully transfered from the polarizer into a glass cell mounted in a magnetic shield and the {sup 3}He free induction decay was detected by a lamp-pumped Cs magnetometer. (orig.)

  11. Delayed protons and properties of proton-rich nuclei

    International Nuclear Information System (INIS)

    Karnaukhov, V.A.

    1976-01-01

    The object of the investigation is to study the properties of proton-rich nuclei. The emphasis in the proposed survey is made on investigations in the range of Z > 50. Measurement of the total energy in emission of delayed protons (DP) enables one to determine the difference between the masses of initial and final isotopes. The statistical model of the DP emission is used for describing the proton spectrum. A comparison of the DP experimental and theoretical spectra shows that the presence of local resonances in the strength functions of the β dacay is rather a rule than an exception. Studies into the fine structure of the proton spectra supply information of the density of nuclei considerably removed from the β-stability line at the excitation energies of 3-7 MeV. The aproaches for retrieval of nuclear information with the aid of proton radiators developed so far can serve as a good basis for systematic investigation over a wide range of A and Z

  12. Coherent population trapping magnetometer by differential detecting magneto–optic rotation effect

    International Nuclear Information System (INIS)

    Zhang Fan; Tian Yuan; Zhang Yi; Gu Si-Hong

    2016-01-01

    A pocket coherent population trapping (CPT) atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated. Using the differential detecting magneto–optic rotation effect, a CPT spectrum with the background canceled and a high signal-to-noise ratio is obtained. The experimental results reveal that the sensitivity of the proposed scheme can be improved by half an order, and the ability to detect weak magnetic fields is extended one-fold. Therefore, the proposed scheme is suited to realize a pocket-size CPT magnetometer. (paper)

  13. Obtaining 'images' from iron objects using a 3-axis fluxgate magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Chilo, Jose [University of Gaevle, S-80176 Gaevle (Sweden); Jabor, Abbas [Royal Institute of Technology, Department of Physics, S-106 91 Stockholm (Sweden); Lizska, Ludwik [Swedish Institute of Space Physics in Umea (Sweden); Eide, Age J. [Ostfold University College, N-1757 Halden (Norway); Lindblad, Thomas [Royal Institute of Technology, Department of Physics, S-106 91 Stockholm (Sweden)], E-mail: lindblad@particle.kth.se

    2007-10-01

    Magnetic objects can cause local variations in the Earth's magnetic field that can be measured with a magnetometer. Here we used tri-axial magnetometer measurements and an analysis method employing wavelet techniques to determine the 'signature' or 'fingerprint' of different iron objects. Clear distinctions among the iron samples were observed. The time-dependent changes in the frequency powers were extracted by use of the Morlet wavelet corresponding to frequency bands from 0.1 to 100 Hz.

  14. Construction and calibration of a low cost and fully automated vibrating sample magnetometer

    Science.gov (United States)

    El-Alaily, T. M.; El-Nimr, M. K.; Saafan, S. A.; Kamel, M. M.; Meaz, T. M.; Assar, S. T.

    2015-07-01

    A low cost vibrating sample magnetometer (VSM) has been constructed by using an electromagnet and an audio loud speaker; where both are controlled by a data acquisition device. The constructed VSM records the magnetic hysteresis loop up to 8.3 KG at room temperature. The apparatus has been calibrated and tested by using magnetic hysteresis data of some ferrite samples measured by two scientifically calibrated magnetometers; model (Lake Shore 7410) and model (LDJ Electronics Inc. Troy, MI). Our VSM lab-built new design proved success and reliability.

  15. Integrated high-transition temperature magnetometer with only two superconducting layers

    DEFF Research Database (Denmark)

    Kromann, R.; Kingston, J.J.; Miklich, A.H.

    1993-01-01

    We describe the fabrication and testing of an integrated YBa2Cu3O7-x thin-film magnetometer consisting of a dc superconducting quantum interference device (SQUID), with biepitaxial grain boundary junctions, integrated with a flux transformer on a single substrate. Only two superconducting layers...... are required, the SQUID body serving as the crossunder that completes the multiturn flux transformer. The highest temperature at which any of the magnetometers functioned was 76 K. At 60 K the magnetic field gain of this device was 63, and the magnetic field noise was 160 fT Hz-1/2 at 2 kHz, increasing to 3...

  16. Membrane-based torque magnetometer: Enhanced sensitivity by optical readout of the membrane displacement

    Science.gov (United States)

    Blankenhorn, M.; Heintze, E.; Slota, M.; van Slageren, J.; Moores, B. A.; Degen, C. L.; Bogani, L.; Dressel, M.

    2017-09-01

    The design and realization of a torque magnetometer is reported that reads the deflection of a membrane by optical interferometry. The compact instrument allows for low-temperature measurements of tiny crystals less than a microgram with a significant improvement in sensitivity, signal-to-noise ratio as well as data acquisition time compared with conventional magnetometry and offers an enormous potential for further improvements and future applications in different fields. Magnetic measurements on single-molecule magnets demonstrate the applicability of the membrane-based torque magnetometer.

  17. Vector magnetometer design study: Analysis of a triaxial fluxgate sensor design demonstrates that all MAGSAT Vector Magnetometer specifications can be met

    Science.gov (United States)

    Adams, D. F.; Hartmann, U. G.; Lazarow, L. L.; Maloy, J. O.; Mohler, G. W.

    1976-01-01

    The design of the vector magnetometer selected for analysis is capable of exceeding the required accuracy of 5 gamma per vector field component. The principal elements that assure this performance level are very low power dissipation triaxial feedback coils surrounding ring core flux-gates and temperature control of the critical components of two-loop feedback electronics. An analysis of the calibration problem points to the need for improved test facilities.

  18. Detailed magnetic survey at Dahshour archeological sites Southwest Cairo, Egypt

    Science.gov (United States)

    Mekkawi, Mahmoud; Arafa-Hamed, Tarek; Abdellatif, Tareq

    2013-06-01

    Dahshour area has recently shown a great potential of archeological findings. This was remarkable from the latest discovery of the causeway and the mortuary temple of the Pyramid of Amenemhat III using geophysical data. The main objective of the present work is to locate the buried archeological remains in the area of Dahshour, Southwest Cairo using magnetic survey for shallow investigations. Land magnetic data is acquired using proton magnetometer (two sensors) with a sensor separation of 0.8 m; i.e. gradiometer survey. The study area is located nearby the two known pyramids of Dahshour. The field data is processed and analyzed using Oasis Montaj Geosoft™ software. The processed data is presented in order to delineate the hidden artifacts causing the magnetic anomalies. The results indicated a distribution of the buried archeological features within the study area. These archeological features are detected according to the magnetic contrast between the magnetic archeological sources (such as mud bricks, basalt and granite) and the surroundings; mainly sandy soil. The delineated archeological features at Dahshour are probably dated back to the old kingdom having a depth reach up to 3.0 m. Consequently it is highly recommended to carry out excavation to precisely classify them and high light their nature and value.

  19. Lunar magnetic anomalies detected by the Apollo substatellite magnetometers

    Science.gov (United States)

    Hood, L.L.; Coleman, P.J.; Russell, C.T.; Wilhelms, D.E.

    1979-01-01

    Properties of lunar crustal magnetization thus far deduced from Apollo subsatellite magnetometer data are reviewed using two of the most accurate presently available magnetic anomaly maps - one covering a portion of the lunar near side and the other a part of the far side. The largest single anomaly found within the region of coverage on the near-side map correlates exactly with a conspicuous, light-colored marking in western Oceanus Procellarum called Reiner Gamma. This feature is interpreted as an unusual deposit of ejecta from secondary craters of the large nearby primary impact crater Cavalerius. An age for Cavalerius (and, by implication, for Reiner Gamma) of 3.2 ?? 0.2 ?? 109 y is estimated. The main (30 ?? 60 km) Reiner Gamma deposit is nearly uniformly magnetized in a single direction, with a minimum mean magnetization intensity of ???7 ?? 10-2 G cm3/g (assuming a density of 3 g/cm3), or about 700 times the stable magnetization component of the most magnetic returned samples. Additional medium-amplitude anomalies exist over the Fra Mauro Formation (Imbrium basin ejecta emplaced ???3.9 ?? 109 y ago) where it has not been flooded by mare basalt flows, but are nearly absent over the maria and over the craters Copernicus, Kepler, and Reiner and their encircling ejecta mantles. The mean altitude of the far-side anomaly gap is much higher than that of the near-side map and the surface geology is more complex, so individual anomaly sources have not yet been identified. However, it is clear that a concentration of especially strong sources exists in the vicinity of the craters Van de Graaff and Aitken. Numerical modeling of the associated fields reveals that the source locations do not correspond with the larger primary impact craters of the region and, by analogy with Reiner Gamma, may be less conspicuous secondary crater ejecta deposits. The reason for a special concentration of strong sources in the Van de Graaff-Aitken region is unknown, but may be indirectly

  20. Proton movies

    CERN Multimedia

    2009-01-01

    A humorous short film made by three secondary school students received an award at a Geneva film festival. Even without millions of dollars or Hollywood stars at your disposal, it is still possible to make a good science fiction film about CERN. That is what three students from the Collège Madame de Staël in Carouge, near Geneva, demonstrated. For their amateur short film on the LHC, they were commended by the jury of the video and multimedia festival for schools organised by the "Media in education" service of the Canton of Geneva’s Public Education Department. The film is a spoof of a television news report on the LHC start-up. In sequences full of humour and imagination, the reporter conducts interviews with a very serious "Professor Sairne", some protons preparing for their voyage and even the neutrons that were rejected by the LHC. "We got the idea of making a film about CERN at the end of the summer," explains Lucinda Päsche, one of the three students. "We did o...

  1. Aerial gamma ray and magnetic survey: Fremont Quadrangle, Nebraska, Iowa; Lincoln Quadrangle, Nebraska; Manhattan Quadrangle, Kansas; Hutchinson Quadrangle, Kansas. Final report. Volume I

    International Nuclear Information System (INIS)

    1977-11-01

    A high sensitivity airborne radiometric and magnetic survey of the East Salina Basin Area (Kansas and Nebraska) was conducted. The project area, the Hutchinson and Manhattan, Kansas sheets, consists of approximately 30,800 square miles. A total of 11,287 line miles of high sensitivity radiometric and magnetic data were collected. All data were collected utilizing a fixed wing aircraft, and over 3,500 cubic inches of NaI crystal detector. Magnetometer data were collected utilizing a high sensitivity 0.25 gamma, proton magnetometer. All field data were returned to GeoMetrics, Sunnyvale, California computer facilities for processing, statistical analysis and interpretation. As an integral part of this final report, other data are presented which include corrected profiles of all radiometric variables (total count, K, U, Th, U/Th, U/K, and Th/K, ratios), magnetic data, radar altimeter data, barometric altimeter data, air temperature and airborne Bi contributions. Radiometric data presented are corrected for Compton Scatter, altitude dependence and atmospheric Bismuth. These data are presented in the form of strip charts as averaged one second samples using a 5 second moving average window, microfiche and digital magnetic tapes containing raw spectral data, single record data, averaged record data, and statistical analysis results. In addition, computer generated anomaly maps and interpretation maps are presented relating known geology or soil distribution to the corrected radiometric data

  2. Space Weather Magnetometer Set with Automated AC Spacecraft Field Correction for GEO-KOMPSAT-2A

    Science.gov (United States)

    Auster, U.; Magnes, W.; Delva, M.; Valavanoglou, A.; Leitner, S.; Hillenmaier, O.; Strauch, C.; Brown, P.; Whiteside, B.; Bendyk, M.; Hilgers, A.; Kraft, S.; Luntama, J. P.; Seon, J.

    2016-05-01

    Monitoring the solar wind conditions, in particular its magnetic field (interplanetary magnetic field) ahead of the Earth is essential in performing accurate and reliable space weather forecasting. The magnetic condition of the spacecraft itself is a key parameter for the successful performance of the magnetometer onboard. In practice a condition with negligible magnetic field of the spacecraft cannot always be fulfilled and magnetic sources on the spacecraft interfere with the natural magnetic field measured by the space magnetometer. The presented "ready-to-use" Service Oriented Spacecraft Magnetometer (SOSMAG) is developed for use on any satellite implemented without magnetic cleanliness programme. It enables detection of the spacecraft field AC variations on a proper time scale suitable to distinguish the magnetic field variations relevant to space weather phenomena, such as sudden increase in the interplanetary field or southward turning. This is achieved through the use of dual fluxgate magnetometers on a short boom (1m) and two additional AMR sensors on the spacecraft body, which monitor potential AC disturbers. The measurements of the latter sensors enable an automated correction of the AC signal contributions from the spacecraft in the final magnetic vector. After successful development and test of the EQM prototype, a flight model (FM) is being built for the Korean satellite Geo-Kompsat 2A, with launch foreseen in 2018.

  3. Mapping of Ambient Magnetic Fields within Liquid Helium Dewar for Testing of a DC SQUID Magnetometer

    International Nuclear Information System (INIS)

    Newhouse, Randal

    2003-01-01

    In an effort to explore the cavity lights phenomenon, Experimental Facilities Department at SLAC is testing a DC SQUID magnetometer. Due to the nature of the SQUID magnetometer and the intended tests, the earth's magnetic field must be negated. It is proposed to reduce ambient fields using bucking coils. First, however, an accurate map of the magnetic field inside the liquid helium Dewar where the experiment is going to take place needed to be made. This map was made using a three-axis fluxgate magnetometer mounted on a 3D positioning device made for this purpose. A ten inch tall volume within the Dewar was measured at data points approximately an inch from each other in all three axes. A LabVEIW program took readings from the magnetometer at 2 ms intervals for 1000 readings in such a way as to eliminate any ambient 60 Hz signals that may be present in the data. This data was stored in spreadsheet format and was analyzed to determine how the magnetic field within the Dewar was changing as a function of position

  4. Magnetorelaxometry of magnetic nanoparticles with fluxgate magnetometers for the analysis of biological targets

    International Nuclear Information System (INIS)

    Ludwig, Frank; Heim, Erik; Maeuselein, Sascha; Eberbeck, Dietmar; Schilling, Meinhard

    2005-01-01

    A magnetorelaxometry system based on sensitive fluxgate magnetometers for the analysis of the relaxation behavior of magnetic nanoparticles is presented. The system is tested with a dilution series of magnetite. The results are directly compared with data obtained with a SQUID magnetorelaxometry system measured on the same samples. Advantages of using fluxgates rather than SQUIDs for magnetorelaxometry are discussed

  5. Z3 model of Saturns magnetic field and the Pioneer 11 vector helium magnetometer observations

    International Nuclear Information System (INIS)

    Connerney, J.E.P.; Acuna, M.H.; Ness, N.F.

    1984-05-01

    Magnetic field observations obtained by the Pioneer 11 vector helium magnetometer are compared with the Z(sub 3) model magnetic field. These Pioneer 11 observations, obtained at close-in radial distances, constitute an important and independent test of the Z(sub 3) zonal harmonic model, which was derived from Voyager 1 and Voyager 2 fluxgate magnetometer observations. Differences between the Pioneer 11 magnetometer and the Z(sub 3) model field are found to be small (approximately 1%) and quantitatively consistent with the expected instrumental accuracy. A detailed examination of these differences in spacecraft payload coordinates shows that they are uniquely associated with the instrument frame of reference and operation. A much improved fit to the Pioneer 11 observations is obtained by rotation of the instrument coordinate system about the spacecraft spin axis by 1.4 degree. With this adjustment, possibly associated with an instrumental phase lag or roll attitude error, the Pioneer 11 vector helium magnetometer observations are fully consistent with the Voyager Z(sub 3) model

  6. A novel HTS magnetometer, exploiting the low jc of bulk YBCO

    International Nuclear Information System (INIS)

    Gallop, J.C.; Lilleyman, S.; Langham, C.D.; Radcliffe, W.J.; Stewart, M.

    1989-01-01

    The authors report here a novel of magnetometer which is based on the low critical magnetic field H/sub cl/ of sintered samples of the high temperature ceramic superconductor YBa/sub 2/Cu/sub 3/O/sub y/. By driving a sample of the superconductor around a magnetization hysteresis loop, at a frequency of --100 kHz, and detecting the induced voltage in a coil coupled to the sample, at the second harmonic of the drive frequency, the authors find that this voltage is linearly dependent on the aplied d.c. magnetic field in which the sample is situated. They present a model which explains the operation of this magnetometer. This device, while not as sensitive as a SQUID, has the advantage of a wider dynamic range and direct measurement of flux density, unlike a SQUID which is only capable of sensing flux density changes. When operated at 77K the prototype magnetometer has already demonstrated a sensitivity at least 10 times better than that of a commercial fluxgate magnetometer. The system also appears to provide a simple method for investigation of flux flow in these materials

  7. Harmonic detection of magnetic resonance for sensitivity improvement of optical atomic magnetometers

    Energy Technology Data Exchange (ETDEWEB)

    Ranjbaran, M. [Laser and Plasma Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Tehranchi, M.M., E-mail: teranchi@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Physics Department, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Hamidi, S.M. [Laser and Plasma Research Institute, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Khalkhali, S.M.H. [Physics Department, Kharazmi University, Tehran (Iran, Islamic Republic of)

    2017-02-15

    Highly sensitive atomic magnetometers use optically detected magnetic resonance of atomic spins to measure extremely weak magnetic field changes. The magnetometer sensitivity is directly proportional to the ratio of intensity to line-shape of the resonance signal. To obtain narrower resonance signal, we implemented harmonic detection of magnetic resonance method in M{sub x} configuration. The nonlinear spin polarization dynamics in detection of the higher harmonics were employed in phenomenological Bloch equations. The measured and simulated harmonic components of the resonance signals in frequency domain yielded significantly narrower line-width accompanying much improved sensitivity. Our results confirm the sensitivity improvement by a factor of two in optical atomic magnetometer via second harmonic signal which can open a new insight in the weak magnetic field measurement system design. - Highlights: • Highly sensitive atomic magnetometers have been used to measure weak magentic filed. • To obtain narrower resonance signal, we impalnted harmonic detection of magnetic resonance. • The nonlinear spin polarization dynamics in detetion of the higher harmonics were imployed.

  8. Performance Improvement of Inertial Navigation System by Using Magnetometer with Vehicle Dynamic Constraints

    Directory of Open Access Journals (Sweden)

    Daehee Won

    2015-01-01

    Full Text Available A navigation algorithm is proposed to increase the inertial navigation performance of a ground vehicle using magnetic measurements and dynamic constraints. The navigation solutions are estimated based on inertial measurements such as acceleration and angular velocity measurements. To improve the inertial navigation performance, a three-axis magnetometer is used to provide the heading angle, and nonholonomic constraints (NHCs are introduced to increase the correlation between the velocity and the attitude equation. The NHCs provide a velocity feedback to the attitude, which makes the navigation solution more robust. Additionally, an acceleration-based roll and pitch estimation is applied to decrease the drift when the acceleration is within certain boundaries. The magnetometer and NHCs are combined with an extended Kalman filter. An experimental test was conducted to verify the proposed method, and a comprehensive analysis of the performance in terms of the position, velocity, and attitude showed that the navigation performance could be improved by using the magnetometer and NHCs. Moreover, the proposed method could improve the estimation performance for the position, velocity, and attitude without any additional hardware except an inertial sensor and magnetometer. Therefore, this method would be effective for ground vehicles, indoor navigation, mobile robots, vehicle navigation in urban canyons, or navigation in any global navigation satellite system-denied environment.

  9. Validation of the GOES-16 magnetometer using multipoint measurements and magnetic field models

    Science.gov (United States)

    Califf, S.; Loto'aniu, P. T. M.; Redmon, R. J.; Sarris, T. E.; Brito, T.

    2017-12-01

    The Geostationary Operational Environmental Satellites (GOES) have been providing continuous geomagnetic field measurements for over 40 years. While the primary purpose of GOES is operational, the magnetometer data are also widely used in the scientific community. In an effort to validate the recently launched GOES-16 magnetometer, we compare the measurements to existing magnetic field models and other GOES spacecraft currently on orbit. There are four concurrent measurements from GOES-13, 14, 15 and 16 spanning 75W to 135W longitude. Also, GOES-13 is being replaced by GOES-16 in the GOES-East location, and during the transition, GOES-13 and GOES-16 will be parked nearby in order to assist with calibration of the new operational satellite. This work explores techniques to quantify the performance of the GOES-16 magnetometer by comparison to data from nearby spacecraft. We also build on previous work to assimilate in situ measurements with existing magnetic field models to assist in comparing data from different spatial locations. Finally, we use this unique dataset from four simultaneous geosynchronous magnetometer measurements and the close separation between GOES-13 and GOES-16 to study the spatial characteristics of ULF waves and other magnetospheric processes.

  10. MgB2 magnetometer with directly coupled pick-up loop

    NARCIS (Netherlands)

    Portesi, C.; Mijatovic, D.; Veldhuis, Dick; Brinkman, Alexander; Monticone, E.; Gonnelli, R.S.

    2006-01-01

    magnetometer with a directly coupled pick-up loop. We used an all in situ technique for fabricating magnesium diboride films, which consists of the co-evaporation of B and Mg by means of an e-gun and a resistive heater respectively. Consequently, we realized the superconducting device, which

  11. Design Principles of A Sigma-delta Flux-gate Magnetometer

    Science.gov (United States)

    Magnes, W.; Valavanoglou, A.; Pierce, D.; Frank, A.; Schwingenschuh, K.

    A state-of-the-art flux-gate magnetometer is characterised by magnetic field resolution of several pT in a wide frequency range, low power consumption, low weight and high robustness. Therefore, flux-gate magnetometers are frequently used for ground-based Earth's field observation as well as for measurements aboard scientific space missions. But both traditional analogue and recently developed digital flux-gate magnetometers need low power and high-resolution analogue-to-digital converters for signal quan- tization. The disadvantage of such converters is the low radiation hardness. This fact has led to the idea of combining a traditional analogue flux-gate regulation circuit with that of a discretely realized sigma-delta converter in order to get a radiation hard and further miniaturized magnetometer. The name sigma-delta converter is derived from putting an integrator in front of a 1-bit delta modulator which forms the sigma-delta loop. It is followed by a digital decimation filter realized in a field-programmable gate array (FPGA). The flux-gate regulation and the sigma-delta loop are quite similar in the way of realizing the integrator and feedback circuit, which makes it easy to com- bine these two systems. The presented talk deals with the design principles and the results of a first bread board model.

  12. The Future of Ground Magnetometer Arrays in Support of Space Weather Monitoring and Research

    Science.gov (United States)

    Engebretson, Mark; Zesta, Eftyhia

    2017-11-01

    A community workshop was held in Greenbelt, Maryland, on 5-6 May 2016 to discuss recommendations for the future of ground magnetometer array research in space physics. The community reviewed findings contained in the 2016 Geospace Portfolio Review of the Geospace Section of the Division of Atmospheric and Geospace Science of the National Science Foundation and discussed the present state of ground magnetometer arrays and possible pathways for a more optimal, robust, and effective organization and scientific use of these ground arrays. This paper summarizes the report of that workshop to the National Science Foundation (Engebretson & Zesta, as well as conclusions from two follow-up meetings. It describes the current state of U.S.-funded ground magnetometer arrays and summarizes community recommendations for changes in both organizational and funding structures. It also outlines a variety of new and/or augmented regional and global data products and visualizations that can be facilitated by increased collaboration among arrays. Such products will enhance the value of ground-based magnetometer data to the community's effort for understanding of Earth's space environment and space weather effects.

  13. A nitrogen triple-point thermal storage unit for cooling a SQUID magnetometer

    NARCIS (Netherlands)

    Rijpma, A.P.; Meenderink, D.J.; Reincke, H.A.; Venhorst, G.C.F.; Holland, H.J.; Brake, ter H.J.M.

    2005-01-01

    In order to achieve turnkey operation, the use is planned of cryocoolers to cool a SQUID magnetometer system. To minimize the magnetical and mech. interference from the coolers, they are switched off during the actual measurements. Consequently, a thermal storage unit (TSU) is required with

  14. A nitrogen triple-point thermal storage unit for cooling a SQUID magnetometer

    NARCIS (Netherlands)

    Rijpma, A.P.; Meenderink, D.J.; Reincke, H.A.; Venhorst, G.C.F.; Venhorst, G.C.F.; Holland, Herman J.; ter Brake, Hermanus J.M.

    2005-01-01

    In order to achieve turnkey operation, we plan to use cryocoolers to cool a SQUID magnetometer system. To minimize the magnetical and mechanical interference from the coolers, we intend to switch them off during the actual measurements. Consequently, a thermal storage unit (TSU) is required with

  15. Characterization and demonstration results of a SQUID magnetometer system developed for geomagnetic field measurements

    Science.gov (United States)

    Kawai, J.; Miyamoto, M.; Kawabata, M.; Nosé, M.; Haruta, Y.; Uehara, G.

    2017-08-01

    We characterized a low temperature superconducting quantum interference device (SQUID) magnetometer system developed for high-sensitivity geomagnetic field measurement, and demonstrated the detection of weak geomagnetic signals. The SQUID magnetometer system is comprised of three-axis SQUID magnetometers housed in a glass fiber reinforced plastic cryostat, readout electronics with flux locked loop (FLL), a 24-bit data logger with a global positioning system and batteries. The system noise was approximately 0.2 pT √Hz- 1/2 in the 1-50 Hz frequency range. This performance was determined by including the thermal noise and the shielding effect of the copper shield, which covered the SQUID magnetometers to eliminate high-frequency interference. The temperature drift of the system was ˜0.8 pT °C- 1 in an FLL operation. The system operated for a month using 33 l liquid helium. Using this system, we performed the measurements of geomagnetic field in the open-air, far away from the city. The system could detect weak geomagnetic signals such as the Schumann resonance with sixth harmonics, and the ionospheric Alfvén resonance appearing at night, for the north-south and east-west components of the geomagnetic field. We confirm that the system was capable of high-sensitivity measurement of the weak geomagnetic activities.

  16. Magnetogate: Using an iPhone Magnetometer for Measuring Kinematic Variables

    Science.gov (United States)

    Temiz, Burak Kagan; Yavuz, Ahmet

    2016-01-01

    This paper presents a method to measure the movement of an object from specific locations on a straight line using an iPhone's magnetometer. In this method, called "magnetogate," an iPhone is placed on a moving object (in this case a toy car) and small neodymium magnets are arranged at equal intervals on one side of a straight line. The…

  17. Proton-air and proton-proton cross sections

    Directory of Open Access Journals (Sweden)

    Ulrich Ralf

    2013-06-01

    Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.

  18. Radiotherapy Proton Interactions in Matter

    OpenAIRE

    Gottschalk, Bernard

    2018-01-01

    A survey of physics useful to proton radiotherapy, centered on stopping, scattering and hard scatters: 1. Introduction 2. The fundamental formula dose = fluence x mass stopping power. Practical units, comments on effective stopping power. 3. Range: experimental definition, Beth-Bloch CSDA theory, range-energy tables and approximations, range straggling. 4. Multiple Coulomb Scattering: suggested reading, elements of Moliere theory, the Gaussian approximation, scattering power. 5. Hard scatters...

  19. A game-theoretic approach for calibration of low-cost magnetometers under noise uncertainty

    Science.gov (United States)

    Siddharth, S.; Ali, A. S.; El-Sheimy, N.; Goodall, C. L.; Syed, Z. F.

    2012-02-01

    Pedestrian heading estimation is a fundamental challenge in Global Navigation Satellite System (GNSS)-denied environments. Additionally, the heading observability considerably degrades in low-speed mode of operation (e.g. walking), making this problem even more challenging. The goal of this work is to improve the heading solution when hand-held personal/portable devices, such as cell phones, are used for positioning and to improve the heading estimation in GNSS-denied signal environments. Most smart phones are now equipped with self-contained, low cost, small size and power-efficient sensors, such as magnetometers, gyroscopes and accelerometers. A magnetometer needs calibration before it can be properly employed for navigation purposes. Magnetometers play an important role in absolute heading estimation and are embedded in many smart phones. Before the users navigate with the phone, a calibration is invoked to ensure an improved signal quality. This signal is used later in the heading estimation. In most of the magnetometer-calibration approaches, the motion modes are seldom described to achieve a robust calibration. Also, suitable calibration approaches fail to discuss the stopping criteria for calibration. In this paper, the following three topics are discussed in detail that are important to achieve proper magnetometer-calibration results and in turn the most robust heading solution for the user while taking care of the device misalignment with respect to the user: (a) game-theoretic concepts to attain better filter parameter tuning and robustness in noise uncertainty, (b) best maneuvers with focus on 3D and 2D motion modes and related challenges and (c) investigation of the calibration termination criteria leveraging the calibration robustness and efficiency.

  20. A game-theoretic approach for calibration of low-cost magnetometers under noise uncertainty

    International Nuclear Information System (INIS)

    Siddharth, S; Ali, A S; El-Sheimy, N; Goodall, C L; Syed, Z F

    2012-01-01

    Pedestrian heading estimation is a fundamental challenge in Global Navigation Satellite System (GNSS)-denied environments. Additionally, the heading observability considerably degrades in low-speed mode of operation (e.g. walking), making this problem even more challenging. The goal of this work is to improve the heading solution when hand-held personal/portable devices, such as cell phones, are used for positioning and to improve the heading estimation in GNSS-denied signal environments. Most smart phones are now equipped with self-contained, low cost, small size and power-efficient sensors, such as magnetometers, gyroscopes and accelerometers. A magnetometer needs calibration before it can be properly employed for navigation purposes. Magnetometers play an important role in absolute heading estimation and are embedded in many smart phones. Before the users navigate with the phone, a calibration is invoked to ensure an improved signal quality. This signal is used later in the heading estimation. In most of the magnetometer-calibration approaches, the motion modes are seldom described to achieve a robust calibration. Also, suitable calibration approaches fail to discuss the stopping criteria for calibration. In this paper, the following three topics are discussed in detail that are important to achieve proper magnetometer-calibration results and in turn the most robust heading solution for the user while taking care of the device misalignment with respect to the user: (a) game-theoretic concepts to attain better filter parameter tuning and robustness in noise uncertainty, (b) best maneuvers with focus on 3D and 2D motion modes and related challenges and (c) investigation of the calibration termination criteria leveraging the calibration robustness and efficiency. (paper)

  1. Airborne gamma-ray spectrometer and magnetometer survey: Ely quadrangle, Nevada. Final report

    International Nuclear Information System (INIS)

    1980-01-01

    Five uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are tabulated and are shown on the Uranium Anomaly Interpretation Map, together with the interpretation of the magnetic data. This volume contains 12 appendices: flight line map; geology map; explanation of geologic legend; flight line/geology map; pseudo-contour maps; stacked profiles; anomaly maps; geologic histograms; speed and altitude histograms; statistical tables; magnetic and ancillary profile; and test line data

  2. Airborne gamma-ray spectrometer amd magnetometer survey: Santa Maria. Final report

    International Nuclear Information System (INIS)

    1981-01-01

    Fourteen uranium amonalies meet the minimum statistical requirements as defined in Volume I. These anomalies are tabulated and are shown on the uranium anomaly interpretation map, together with the interpretation of the magnetic data

  3. Airborne gamma-ray spectrometer and magnetometer survey: New Rockford quadrangle, North Dakota. Final report

    International Nuclear Information System (INIS)

    1981-04-01

    Volume II contains the flight path, radiometric multi-parameter stacked profiles, magnetic and ancillary parameter stacked profiles, histograms, and anomaly maps for the New Rockford Quadrangle in North Dakota

  4. Airborne gamma-ray spectrometer and magnetometer survey: Victoria quadrangle (Washington). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    One uranium anomaly meets the minimum statistical requirements. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eT), eU/eT, eU/K, eT/K, and magnetic pseudo-contour maps are presented. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation. Anomaly number 1 is over an exposure of the Permian Shuksan metamorphic suite which is predominantly phyllite

  5. Airborne gamma-ray spectrometer and magnetometer survey: Mariposa quadrangle (California, Nevada). Final report

    International Nuclear Information System (INIS)

    1980-01-01

    A total of 15 uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are shown on the Uranium Anomaly Interpretation Map, together with interpretation of the magnetic data. Potassium (K), equivalent uranium (eU), equivalent thorium (eTh), eU/eTh, eU/K, eTh/K, and magnetic Pseudo Contour Maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight line together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II. The anomaly map shows postulated magnetic discontinuities, the outline of shallow magnetic bodies responsible for short wavelength anomalies, and the outline of deep magnetic bodies responsible for the longer wavelength anomalies. The predominant trend in the magnetic discontinuities is north to northwest, which correlates well with the trend of mapped faults in the area. These magnetic discontinuities are interpreted as faults. A second set of east-northeast trending discontinuities off-sets the north to northwest trending set, and are interpreted as faults. The sources of several short wavelength anomalies are Quaternary and Jurassic/Triassic basic volcanic rocks. Longer wavelength anomalies present in the magnetic data are attributed to deep-seated basic igneous rocks

  6. Airborne gamma-ray spectrometer and magnetometer survey: Kingston quadrangle (New York). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    No uranium anomalies meet the minimum statistical requirements as defined in Volume I. There is no Uranium Anomaly Map for this volume. Potassium (%K), equivalent Uranium (ppm eU), equivalent Thorium (ppm eTh), eU/eTh, eU/K, eTh/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II

  7. Airborne gamma-ray spectrometer and magnetometer survey, Peoria quadrangle (IL). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    Twenty-three uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are listed and are shown on the Uranium Anomaly Interpretation Map. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eTh), eU/eTh, eU/K, eTh/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II. Anomalies No. 1 and No. 2, and No. 19 are over areas underlain by the Radnor Till member (Qti) of the Pleistocene Glasford formation. Anomalies No. 3 and No. 5 are over areas underlain by Pleistocene moraine and other deposits of the Fairgrange Till member (Qwf, Qwfm) of the Wedron formation. Anomaly No. 4 is over an area underlain by the Pleistocene Batestown Till member (Qwb) of the Wedron formation. Anomalies No. 6 and No. 7 are over areas underlain by the Delavan Till member (Qwd) of the Pleistocene Wedron formation. Anomalies No. 8 and No. 20 are over areas underlain by Pleistocene moraine deposits of the Yorkville Till member (Qwym) of the Wedron formation. Anomalies No. 9, No. 12, and No. 14 are over areas underlain by Pleistocene moraine deposits of the Snider Till member (Qwsm) of the Wedron formation. Anomalies No. 10, and No. 15 to No. 16 are over areas underlain by the Snider Till member (Qws) of the Wedron formation of Pleistocene age. Anomaly No. 11 is over an area underlain by the Pleistocene Snider Till member (Qws) of the Wedron formation and Cahokia Alluvium

  8. Airborne gamma-ray spectrometer and magnetometer survey: Toronto quadrangle (New York). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    No uranium anomalies meet the minimum statistical requirements as defined in Volume I. There is no Uranium Anomaly Map for this volume. Potassium (%K), equivalent Uranium (ppm eU), equivalent Thorium (ppm eTh), eU/eTh, eU/K, eTh/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II

  9. Airborne gamma-ray spectrometer and magnetometer survey, Bend quadrangle (Oregon). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    Eight uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are listed and are shown on the Uranium Anomaly Interpretation Map. Potassim (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eT), eU/eT, eU/K, eT/K, and Magnetic Pseudo Contour Maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II

  10. Airborne gamma-ray spectrometer and magnetometer survey, Salem quadrangle (Oregon). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    Five uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are tabulated and are shown on the Uranium Anomaly Interpretation Map. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (eT), eU/eT, eU/K, eT/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II. Each of the anomalies occurs over the Eocene Tyee and Burpee formation (Teme), a rhythmically banded, feldspathic and micaceous, massive bedded sandstone, and siltstone. Anomalies 1, 2, 3, and 4 are in the northwest corner of the map. Anomalies 2 and 3 are near faults, so may be due to radon leaking from the faults. Anomaly No. 5 is in the southwest corner of the map

  11. Airborne gamma-ray spectrometer and magnetometer survey, Belleville quadrangle (IL). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    Forty-two uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are listed and are shown on the Uranium Anomaly Interpretation Map. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eTh), eU/eTh, eU/K, eTh/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II. Anomalies No. 1, No. 4 to No. 17, No. 22 to No. 23, and No. 27 to No. 30 are over areas underlain by the Radnor Till member (Qti) of the Pleistocene Glasford formation. Anomalies No. 2 and No. 3 are over areas underlain by Pleistocene Cahokia Alluvium (Qc) and the Radnor Till member (Qti) of the Glasford formation. Anomalies No. 18 to No. 21, and No. 24 are over areas underlain by the Pleistocene Equality formation (Qcl). Anomalies No. 25 and No. 26 are over areas underlain by the Equality formation (Qcl) and the Radnor Till member (Qti) of the Glasford formation. Both of these formations are of Pleistocene age. Anomalies No. 31 and No. 33 are over areas underlain by the Pleistocene Cahokia Alluvium (Qc). Anomalies No. 32, No. 34 to No. 38, and No. 40 to No. 42 are over areas underlain by the Radnor Till member (Qti) of the Pleistocene Glasford formation. Anomaly No. 39 is over an area underlain by the Radnor Till (Qti) and the Hagarstown (Qgh) members of the Pleistocene Glasford formation

  12. Airborne gamma-ray spectrometer and magnetometer survey. Canyon City quadrangle (Oregon). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    Fourteen uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are listed and are shown on the Uranium Anomaly Interpretation Map. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (eT), eU/eT, eU/K, eT/K, and Magnetic Pseudo Contour Maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II. Anomaly No. 1 is over mainly sedimentary rocks of undifferentitatd Paleozoic/Mesozoic age (MzPza). Anomaly No. 2 is over a fault contact between Strawberry volcanics (Ts), and volcanic rocks of the Clarno (Tc). Anomaly No. 3 is over an intensely faulted block of Strawberry volcanics (Ts). Anomaly No. 4 is over the contact area between Strawberry volcanic rocks (Ts) and a basalt plug of Tertiary age (Tbi). Anomaly No. 5 is over the contact area between volcanic rocks of the Clarno formation (Tc) and undivided sedimentary rocks of Jurassic/Triassic age. Part of the anomaly is over landslide debris (Q1). Anomalies No. 6 and No. 7 are over a fault contact between volcanic rocks of the Clarno formation (Tc) and undivided sedimentary rocks of Jurassic/Triassic age

  13. Airborne gamma-ray spectrometer and magnetometer survey: Rockford quadrangle (IL). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    Eleven uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are tabulated and are shown on the Uranium Anomaly Interpretation Map. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eTh), eU/eTh, eU,K, eTh/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II. Anomaly No. 1 is over an area underlain by the Mackinaw member (Qhm) of the Pleistocene Henry formation. Anomaly No. 2 is over an area underlain by Pleistocene Cahokia Alluvium (Qc) and the Ogle Till member (Qgo) of the Glasford formation. Anomaly No. 3 is over an area underlain by the Ogle Till member (Qgo) of the Pleistocene age. Anomaly No. 4 is over an area underlain by Ordovician Galena Black River Dolomite (Og). Anomaly No. 5 is over an area underlain by the Mackinaw member (Qhm) of the Henry formation and the Capron Till member (Qwic) of the Winnebago formation of Pleistocene ages. Anomaly No. 6 is over an area underlain by the Windlow Till member (Qgw) of the Glasford formation of Pleistocene age. Anomaly No. 7 is over an area underlain by the Argyle Till member (Qwia) o the Winnebago formation of Pleistocene age. Anomaly No. 8 is over an area underlain by the Capron Till member (Qwic) of the Winnebago formation of Pleistocene age. Anomaly No. 9 is over an area underlain by the Pleistocene Carmi member (Qcl) of the Equality formation and undifferentiated ground moraine (Qug). Anomalies No. 10 and No. 11 are over areas underlain by undifferentiated ground moraine (Qug) of Pleistocene age

  14. Airborne gamma-ray spectrometer and magnetometer survey, Copalis Beach quadrangle (Washington). Final report

    International Nuclear Information System (INIS)

    1981-01-01

    No uranium anomalies meet the minimum statistical requirements as defined. There is no Uranium Anomaly Interpretation Map for the Copalis Beach quadrangle. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eT), eU/eT, eU/K, eT/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation

  15. [Survey of the prescriptions of proton pump inhibitors in patients admitted in an internal medicine ward: how is the compliance to the French guidelines?].

    Science.gov (United States)

    Sauvaget, L; Rolland, L; Dabadie, S; Desblaches, J; Bernard, N; Vandenhende, M-A; Bonnet, F; Pédeboscq, S; Morlat, P

    2015-10-01

    In June 2009, the national French authority for Health reported many off-label uses of proton pump inhibitors (PPI). Our objective was to analyse the justification and modalities of PPI prescriptions in patients before their admission in a department of internal medicine. Data were prospectively collected during 5months. At admission, all prescriptions of PPI by general practitioners (GP) were recorded. The accordance of the prescriptions with the marketing authorization indications and the French guidelines in terms of duration of treatment or dosage was analyzed. These informations were obtained from computerized medical records and, if necessary, by contacting GPs. We collected 173 prescriptions. Fifty-six (32%) were in accordance with marketing authorization indications and, among them, 15 prescriptions (9% of all) respected the French guidelines about dosage and duration of treatment. One hundred and six prescriptions (61%) were not adequate and among them an off-label use was notified in 91 (53% of all); among them 33% for simple dyspeptic disorders, 23% for the prevention of NSAID-induced lesions in patients without risk factors, and finally 17% for the prevention of stress ulcer. Fifty-two prescriptions (30%) were unclassified due to incomplete data. Our study showed that a vast majority of the prescriptions for PPIs are not in accordance with French guidelines. Preventive actions against abusive prescriptions, withdrawal strategies or replacement of already prescribed PPIs should be implemented to reduce the risk of side effects and the economic impact of long term use of PPIs. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  16. Hungarian repeat station survey, 2010

    Directory of Open Access Journals (Sweden)

    Péter Kovács

    2013-03-01

    Full Text Available The last Hungarian repeat station survey was completed between October 2010 and February 2011. Declination, inclination and the total field were observed using one-axial DMI fluxgate magnetometer mounted on Zeiss20A theodolite and GSM 19 Overhauser magnetometer. The magnetic elements of the sites were reduced to the epoch of 2010.5 on the basis of the continuous recordings of Tihany Geophysical Observatory. In stations located far from the reference observatory, the observations were carried out in the morning and afternoon in order to decrease the effect of the distant temporal correction. To further increase the accuracy, on-site dIdD variometer has also been installed near the Aggtelek station, in the Baradla cave, during the survey of the easternmost sites. The paper presents the technical details and the results of our last campaign. The improvement of the accuracy of the temporal reduction by the use of the local variometer is also reported.

  17. Proton therapy device

    International Nuclear Information System (INIS)

    Tronc, D.

    1994-01-01

    The invention concerns a proton therapy device using a proton linear accelerator which produces a proton beam with high energies and intensities. The invention lies in actual fact that the proton beam which is produced by the linear accelerator is deflected from 270 deg in its plan by a deflecting magnetic device towards a patient support including a bed the longitudinal axis of which is parallel to the proton beam leaving the linear accelerator. The patient support and the deflecting device turn together around the proton beam axis while the bed stays in an horizontal position. The invention applies to radiotherapy. 6 refs., 5 figs

  18. Empirical Determination of Efficient Sensing Frequencies for Magnetometer-Based Continuous Human Contact Monitoring

    Directory of Open Access Journals (Sweden)

    Seungho Kuk

    2018-04-01

    Full Text Available The high linear correlation between the smartphone magnetometer readings in close proximity can be exploited for physical human contact detection, which could be useful for such applications as infectious disease contact tracing or social behavior monitoring. Alternative approaches using other capabilities in smartphones have aspects that do not fit well with the human contact detection. Using Wi-Fi or cellular fingerprints have larger localization errors than close human contact distances. Bluetooth beacons could reveal the identity of the transmitter, threatening the privacy of the user. Also, using sensors such as GPS does not work for indoor contacts. However, the magnetometer correlation check works best in human contact distances that matter in infectious disease transmissions or social interactions. The omni-present geomagnetism makes it work both indoors and outdoors, and the measured magnetometer values do not easily reveal the identity and the location of the smartphone. One issue with the magnetometer-based contact detection, however, is the energy consumption. Since the contacts can take place anytime, the magnetometer sensing and recording should be running continuously. Therefore, how we address the energy requirement for the extended and continuous operation can decide the viability of the whole idea. However, then, we note that almost all existing magnetometer-based applications such as indoor location and navigation have used high sensing frequencies, ranging from 10 Hz to 200 Hz. At these frequencies, we measure that the time to complete battery drain in a typical smartphone is shortened by three to twelve hours. The heavy toll raises the question as to whether the magnetometer-based contact detection can avoid such high sensing rates while not losing the contact detection accuracy. In order to answer the question, we conduct a measurement-based study using independently produced magnetometer traces from three different

  19. Empirical Determination of Efficient Sensing Frequencies for Magnetometer-Based Continuous Human Contact Monitoring.

    Science.gov (United States)

    Kuk, Seungho; Kim, Junha; Park, Yongtae; Kim, Hyogon

    2018-04-27

    The high linear correlation between the smartphone magnetometer readings in close proximity can be exploited for physical human contact detection, which could be useful for such applications as infectious disease contact tracing or social behavior monitoring. Alternative approaches using other capabilities in smartphones have aspects that do not fit well with the human contact detection. Using Wi-Fi or cellular fingerprints have larger localization errors than close human contact distances. Bluetooth beacons could reveal the identity of the transmitter, threatening the privacy of the user. Also, using sensors such as GPS does not work for indoor contacts. However, the magnetometer correlation check works best in human contact distances that matter in infectious disease transmissions or social interactions. The omni-present geomagnetism makes it work both indoors and outdoors, and the measured magnetometer values do not easily reveal the identity and the location of the smartphone. One issue with the magnetometer-based contact detection, however, is the energy consumption. Since the contacts can take place anytime, the magnetometer sensing and recording should be running continuously. Therefore, how we address the energy requirement for the extended and continuous operation can decide the viability of the whole idea. However, then, we note that almost all existing magnetometer-based applications such as indoor location and navigation have used high sensing frequencies, ranging from 10 Hz to 200 Hz. At these frequencies, we measure that the time to complete battery drain in a typical smartphone is shortened by three to twelve hours. The heavy toll raises the question as to whether the magnetometer-based contact detection can avoid such high sensing rates while not losing the contact detection accuracy. In order to answer the question, we conduct a measurement-based study using independently produced magnetometer traces from three different countries. Specifically, we

  20. Elastic proton-proton scattering at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Yip, K.

    2011-09-03

    Here we describe elastic proton+proton (p+p) scattering measurements at RHIC in p+p collisions with a special optics run of {beta}* {approx} 21 m at STAR, at the center-of-mass energy {radical}s = 200 GeV during the last week of the RHIC 2009 run. We present preliminary results of single and double spin asymmetries.

  1. Baryon production in proton-proton collisions

    International Nuclear Information System (INIS)

    Liu, F.M.; Werner, K.

    2002-01-01

    Motivated by the recent rapidity spectra of baryons and antibaryons in pp collisions at 158 GeV and the Ω-bar/Ω ratio discussion, we reviewed string formation mechanism and some string models. This investigation told us how color strings are formed in ultrarelativistic proton-proton collisions

  2. Proton: the particle.

    Science.gov (United States)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All

  3. Proton: The Particle

    Energy Technology Data Exchange (ETDEWEB)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.

  4. Probabilistic resident space object detection using archival THEMIS fluxgate magnetometer data

    Science.gov (United States)

    Brew, Julian; Holzinger, Marcus J.

    2018-05-01

    Recent progress in the detection of small space objects, at geosynchronous altitudes, through ground-based optical and radar measurements is demonstrated as a viable method. However, in general, these methods are limited to detection of objects greater than 10 cm. This paper examines the use of magnetometers to detect plausible flyby encounters with charged space objects using a matched filter signal existence binary hypothesis test approach. Relevant data-set processing and reduction of archival fluxgate magnetometer data from the NASA THEMIS mission is discussed in detail. Using the proposed methodology and a false alarm rate of 10%, 285 plausible detections with probability of detection greater than 80% are claimed and several are reviewed in detail.

  5. Loop-locked coherent population trapping magnetometer based on a fiber electro-optic modulator.

    Science.gov (United States)

    Hu, Yong; Feng, Y Y; Xu, Chi; Xue, H B; Sun, Li

    2014-04-01

    We have set up a coherent population trapping (CPT)-based magnetometer prototype with the D1 line of ⁸⁷Rb atoms. The dichromatic light field is derived from a fiber electro-optic modulator (FEOM) connected to an external cavity laser diode. A CPT resonance signal with a 516 Hz linewidth is observed. By feeding back the derivative of the resonance curve to the FEOM with a proportional integral controller, of which the voltage output is directly converted to the measured magnetic field intensity, the resonance peak is locked to the environmental magnetic field. The measurement data we have achieved are well matched with the data measured by a commercial fluxgate magnetometer within 2 nT, and the sensitivity is better than 8 pT/√Hz in a parallel B field.

  6. New type of fluxgate magnetometer for the heart’s magnetic fields detection

    Directory of Open Access Journals (Sweden)

    Rybalko Ruslan

    2015-09-01

    Full Text Available The application area of fluxgate sensors is limited by their sensitivity. Medical researches create high demand on the magnetometers with the characteristics of high accuracy and sensibility for measuring weak magnetic fields produced by the human body, such as the heart‘s magnetic field. Due to the insufficient sensitivity of fluxgate sensors, superconducting magnetometers (SQUID take the dominant position for the cardiomagnetic measurements. They have to be cooled by liquefied gases and it leads to high service costs. Therefore an idea of creating a high sensitive sensor based on fluxgate principles and known methods of measurement is attractive and up to date. This paper is dedicated to the modified flux-gate sensors based on Racetrack technology with a new approach of signal demodulation. The improved fluxgate sensor system provides detection of the heart‘s magnetic field without additional expenditures for use.

  7. On-orbit real-time magnetometer bias determination for micro-satellites without attitude information

    Directory of Open Access Journals (Sweden)

    Zhang Zhen

    2015-10-01

    Full Text Available Due to the disadvantages such as complex calculation, low accuracy of estimation, and being non real time in present methods, a new real-time algorithm is developed for on-orbit magnetometer bias determination of micro-satellites without attitude knowledge in this paper. This method uses the differential value approach. It avoids the impact of quartic nature and uses the iterative method to satisfy real-time applications. Simulation results indicate that the new real-time algorithm is more accurate compared with other methods, which are also tested by an experiment system using real noise data. With the new real-time algorithm, a magnetometer calibration can be taken on-orbit and will reduce the demand for computing power effectively.

  8. Research on Intelligent Control System of DC SQUID Magnetometer Parameters for Multi-channel System

    Science.gov (United States)

    Chen, Hua; Yang, Kang; Lu, Li; Kong, Xiangyan; Wang, Hai; Wu, Jun; Wang, Yongliang

    2018-03-01

    In a multi-channel SQUID measurement system, adjusting device parameters to optimal condition for all channels is time-consuming. In this paper, an intelligent control system is presented to determine the optimal working point of devices which is automatic and more efficient comparing to the manual one. An optimal working point searching algorithm is introduced as the core component of the control system. In this algorithm, the bias voltage V_bias is step scanned to obtain the maximal value of the peak-to-peak current value I_pp of the SQUID magnetometer modulation curve. We choose this point as the optimal one. Using the above control system, more than 30 weakly damped SQUID magnetometers with area of 5 × 5 mm^2 or 10 × 10 mm^2 are adjusted and a 36-channel magnetocardiography system perfectly worked in a magnetically shielded room. The average white flux noise is 15 μΦ_0/Hz^{1/2}.

  9. Searching for axion stars and Q-balls with a terrestrial magnetometer network

    Energy Technology Data Exchange (ETDEWEB)

    Jackson Kimball, D. F. [Cal State, East Bay; Budker, D. [UC, Berkeley; Eby, J. [Fermilab; Pospelov, M. [Perimeter Inst. Theor. Phys.; Pustelny, S. [Jagiellonian U.; Scholtes, T. [Fribourg U.; Stadnik, Y. V. [Helmholtz Inst., Mainz; Weis, A. [Fribourg U.; Wickenbrock, A. [Mainz U.

    2017-10-11

    Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q-balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q-balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown that a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q-ball could be detected over a broad range of unexplored parameter space.

  10. Automatic torque magnetometer for vacuum-to-high-pressure hydrogen environments

    International Nuclear Information System (INIS)

    Larsen, J.W.; Livesay, B.R.

    1979-01-01

    An automatic torque magnetometer has been developed for use in high-pressure hydrogen. It will contain pressures ranging from vacuum to 200 atm of hydrogen gas at sample temperatures greater than 400 0 C. This magnetometer, which uses an optical lever postion sensor and a restoring force technique has an operating range of 2.0 x 10 3 dyn cm to l.6 x 10 -4 dyn cm. An accompanying digital data collection system extends the sensitivity to 1 x 10 -5 dyn cm as well as increasing the data handling capacity of the system. The magnetic properties of thin films in high-temperature and high-pressure hydrogen environments can be studied using this instruments

  11. Micromechanical ``Trampoline'' Magnetometers for Use in Pulsed Magnetic Fields Exceeding 60 Tesla

    Science.gov (United States)

    Balakirev, F. F.; Boebinger, G. S.; Aksyuk, V.; Gammel, P. L.; Haddon, R. C.; Bishop, D. J.

    1998-03-01

    We present the design, construction, and operation of a novel magnetometer for use in intense pulsed magnetic fields. The magnetometer consists of a silicon micromachined "trampoline" to which the sample is attached. The small size of the device (typically 400 microns on a side) gives a fast mechanical response (10,000 to 50,000 Hz) and extremely high sensitivity (10-11 Am^2, corresponding to 10-13 Am^2/Hz^(1/2)). The device is robust against electrical and mechanical noise and requires no special vibration isolation from the pulsed magnet. As a demonstration, we present data taken in a 60 tesla pulsed magnetic field which show clear de Haas-van Alphen oscillations in a one microgram sample of the organic superconductor K-(BEDT-TTF)_2Cu(NCS)_2.

  12. Feasibility study of a sup 3 He-magnetometer for neutron electric dipole moment experiments

    CERN Document Server

    Borisov, Y; Leduc, M; Lobashev, V; Otten, E W; Sobolev, Y

    2000-01-01

    We report on a sup 3 He-magnetometer capable of detecting tiny magnetic field fluctuations of less than 10 sup - sup 1 sup 4 T in experiments for measuring the electric dipole moment (EDM) of the neutron. It is based on the Ramsey technique of separated oscillating fields and uses nuclear spin-polarized sup 3 He gas which is stored in two vessels of V approx =10 l in a sandwich-type arrangement around the storage bottle for ultra-cold neutrons (UCN). The gas is polarized by means of optical pumping in a separate, small discharge cell at pressures around 0.5 mbar and is then expanded into the actual magnetometer volume. To detect the polarization of sup 3 He gas at the end of the storage cycle the gas is pumped out by means of an oil-diffusion pump and compressed again into the discharge cell where optical detection of nuclear polarization is used.

  13. Magnetic shield effect simulation of superconducting film shield covering directly coupled HTS dc-SQUID magnetometer

    International Nuclear Information System (INIS)

    Terauchi, N.; Noguchi, S.; Igarashi, H.

    2011-01-01

    A superconducting film shield over a SQUID ring improves the robustness of the SQUID with respect to magnetic noise. Supercurrent in the SQUID magnetometer and the superconducting film shield were simulated. The superconducting film shield reduces the influence of the external magnetic field on the SQUID ring. An HTS SQUID is a high sensitive magnetic sensor. In recent years, the HTS SQUID is widely used in various applications. In some applications, high robustness with respect to magnetic noise is required to realize stable operation at outside of a magnetic shielding room. The target of this paper is a directly coupled HTS dc-SQUID magnetometer. To enhance the robustness of the SQUID magnetometer, use of a superconducting thin film shield has been proposed. The magnetic field directly penetrating the SQUID ring causes the change of the critical current of Josephson junction, and then the SQUID magnetometer transitions into inoperative state. In order to confirm the magnetic shield effect of the superconducting film shield, electromagnetic field simulation with 3D edge finite element method was performed. To simulate the high temperature superconductor, E-J characteristics and c-axis anisotropy are considered. To evaluate the effect of the superconducting film shield, an external magnetic field which is supposed to be a magnetic noise is applied. From the simulation results, the time transition of the magnetic flux penetrating the SQUID ring is investigated and the effect of the superconducting film shield is confirmed. The amplitude of the magnetic flux penetrating the SQUID ring can be reduced to about one-sixth since the superconducting film shield prevents the magnetic noise from directly penetrating the SQUID ring.

  14. Identification of Mobile Phones Using the Built-In Magnetometers Stimulated by Motion Patterns

    Directory of Open Access Journals (Sweden)

    Gianmarco Baldini

    2017-04-01

    Full Text Available We investigate the identification of mobile phones through their built-in magnetometers. These electronic components have started to be widely deployed in mass market phones in recent years, and they can be exploited to uniquely identify mobile phones due their physical differences, which appear in the digital output generated by them. This is similar to approaches reported in the literature for other components of the mobile phone, including the digital camera, the microphones or their RF transmission components. In this paper, the identification is performed through an inexpensive device made up of a platform that rotates the mobile phone under test and a fixed magnet positioned on the edge of the rotating platform. When the mobile phone passes in front of the fixed magnet, the built-in magnetometer is stimulated, and its digital output is recorded and analyzed. For each mobile phone, the experiment is repeated over six different days to ensure consistency in the results. A total of 10 phones of different brands and models or of the same model were used in our experiment. The digital output from the magnetometers is synchronized and correlated, and statistical features are extracted to generate a fingerprint of the built-in magnetometer and, consequently, of the mobile phone. A SVM machine learning algorithm is used to classify the mobile phones on the basis of the extracted statistical features. Our results show that inter-model classification (i.e., different models and brands classification is possible with great accuracy, but intra-model (i.e., phones with different serial numbers and same model classification is more challenging, the resulting accuracy being just slightly above random choice.

  15. Simulation and measurement of ferromagnetic impurities in non-magnetic aeroengine turbine disks using fluxgate magnetometers

    OpenAIRE

    Sebastian Hantscher; Ruixin Zhou; Albert Seidl; Johann Hinken; Christian Ziep

    2015-01-01

    In this paper, ferromagnetic impurities in paramagnetic aeroengine turbine disks are investigated. Because such inclusions represent a significant threat in aviation, a detailed analysis is required for impured turbine disks. For this purpose, sensitive fluxgate magnetometers are used. After a premagnetisation, this sensor is able to detect small ferromagnetic particles by recording the variation of the magnetic flux density while the disk rotates below the sensor head. This trajectory create...

  16. High-Sensitivity Low-Noise Miniature Fluxgate Magnetometers Using a Flip Chip Conceptual Design

    OpenAIRE

    Lu, Chih-Cheng; Huang, Jeff; Chiu, Po-Kai; Chiu, Shih-Liang; Jeng, Jen-Tzong

    2014-01-01

    This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB) substrate and electrically connected to each other similar to the current “flip chip” concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. P...

  17. Hypervelocity dust particle impacts observed by the Giotto Magnetometer and Plasma Experiments

    OpenAIRE

    Neubauer, F. M.; Glassmeier, K. H.; Coates, A. J.; Goldstein, R.; Acuña, M. H.; Musmann, G.

    1990-01-01

    We report thirteen very short events in the magnetic field of the inner magnetic pile‐up region of comet Halley observed by the Giotto magnetometer experiment together with simultaneous plasma data obtained by the Johnstone plasma analyzer and the ion mass spectrometer experiments. The events are due to dust impacts in the milligram range on the spacecraft at the relative velocity between the cemetery dust and the spacecraft of 68 km/sec. They are generally consistent with dust impact events ...

  18. The MAGIC of CINEMA: first in-flight science results from a miniaturised anisotropic magnetoresistive magnetometer

    Directory of Open Access Journals (Sweden)

    M. O. Archer

    2015-06-01

    Full Text Available We present the first in-flight results from a novel miniaturised anisotropic magnetoresistive space magnetometer, MAGIC (MAGnetometer from Imperial College, aboard the first CINEMA (CubeSat for Ions, Neutrals, Electrons and MAgnetic fields spacecraft in low Earth orbit. An attitude-independent calibration technique is detailed using the International Geomagnetic Reference Field (IGRF, which is temperature dependent in the case of the outboard sensor. We show that the sensors accurately measure the expected absolute field to within 2% in attitude mode and 1% in science mode. Using a simple method we are able to estimate the spacecraft's attitude using the magnetometer only, thus characterising CINEMA's spin, precession and nutation. Finally, we show that the outboard sensor is capable of detecting transient physical signals with amplitudes of ~ 20–60 nT. These include field-aligned currents at the auroral oval, qualitatively similar to previous observations, which agree in location with measurements from the DMSP (Defense Meteorological Satellite Program and POES (Polar-orbiting Operational Environmental Satellites spacecraft. Thus, we demonstrate and discuss the potential science capabilities of the MAGIC instrument onboard a CubeSat platform.

  19. Fluxgate magnetometer offset vector determination by the 3D mirror mode method

    Science.gov (United States)

    Plaschke, F.; Goetz, C.; Volwerk, M.; Richter, I.; Frühauff, D.; Narita, Y.; Glassmeier, K.-H.; Dougherty, M. K.

    2017-07-01

    Fluxgate magnetometers on-board spacecraft need to be regularly calibrated in flight. In low fields, the most important calibration parameters are the three offset vector components, which represent the magnetometer measurements in vanishing ambient magnetic fields. In case of three-axis stabilized spacecraft, a few methods exist to determine offsets: (I) by analysis of Alfvénic fluctuations present in the pristine interplanetary magnetic field, (II) by rolling the spacecraft around at least two axes, (III) by cross-calibration against measurements from electron drift instruments or absolute magnetometers, and (IV) by taking measurements in regions of well-known magnetic fields, e.g. cometary diamagnetic cavities. In this paper, we introduce a fifth option, the 3-dimensional (3D) mirror mode method, by which 3D offset vectors can be determined using magnetic field measurements of highly compressional waves, e.g. mirror modes in the Earth's magnetosheath. We test the method by applying it to magnetic field data measured by the following: the Time History of Events and Macroscale Interactions during Substorms-C spacecraft in the terrestrial magnetosheath, the Cassini spacecraft in the Jovian magnetosheath and the Rosetta spacecraft in the vicinity of comet 67P/Churyumov-Gerasimenko. The tests reveal that the achievable offset accuracies depend on the ambient magnetic field strength (lower strength meaning higher accuracy), on the length of the underlying data interval (more data meaning higher accuracy) and on the stability of the offset that is to be determined.

  20. Integrated de SQUID magnetometer with high dV/dB

    International Nuclear Information System (INIS)

    Drung, D.; Cantor, R.; Peters, M.; Ryhanen, T.; Kochi, H.

    1991-01-01

    This paper presents a directly coupled dc SQUID magnetometer with very simple feedback electronics. The magnetometer has been integrated on a 7.2 x 7.2 mm 2 chip and fabricated using a four-level Nb/Si x N v /Nb process. Eight pick-up loops are connected in parallel to directly form the SQUID inductance of about 0.4 nH which leads to a high sensitivity B/Φ = 0.47 nT/Φ. An Additional Positive Feedback (APF) circuit on the magnetometer chip has been used to increase the gradient of the V-μ characteristic to dV/dΦ ≅ 300 μV/Φ 0 at the SQUID operating point. The resulting gradient of the transfer function of dV/dB ≅ 640 μV/nT makes it possible to directly read out the SQUID without helium temperature impedance matching circuits or flux modulation techniques

  1. Intense auroral field-aligned currents and electrojets detected by rocket-borne fluxgate magnetometer

    International Nuclear Information System (INIS)

    Tohyama, Fumio; Fukunishi, Hiroshi; Takahashi, Takao; Kokubun, Susumu; Fujii, Ryoichi; Yamagishi, Hisao.

    1988-01-01

    The S-310JA-11 and S-310JA-12 rockets, having a vector magnetometer with high sensitivity (1.8 nT) and high sampling frequency (100 Hz), were launched into the aurora on May 29 and July 12, 1985, from Syowa Station, Antarctica. The S-310JA-11 rocket penetrated twice quiet arcs, while the S-310JA-12 rocket traversed across intense and active auroral arcs during a large magnetic substorm. In the S-310JA-12 rocket experiment, intense field-aligned currents of 400 - 600 nT were observed when the rocket penetrated an active arc during the descending flight. The magnetometer on board the S-310JA-12 rocket also detected intense electrojet currents with a center at 110 km on the upward leg and at 108 km on the downward leg. The magnetometer data of the S-310JA-11 rocket showed no distinguished magnetic field variation due to field-aligned current and electrojet. (author)

  2. Attitude Determination with Magnetometers and Accelerometers to Use in Satellite Simulator

    Directory of Open Access Journals (Sweden)

    Helio Koiti Kuga

    2013-01-01

    Full Text Available Attitude control of artificial satellites is dependent on information provided by its attitude determination process. This paper presents the implementation and tests of a fully self-contained algorithm for the attitude determination using magnetometers and accelerometers, for application on a satellite simulator based on frictionless air bearing tables. However, it is known that magnetometers and accelerometers need to be calibrated so as to allow that measurements are used to their ultimate accuracy. A calibration method is implemented which proves to be essential for improving attitude determination accuracy. For the stepwise real-time attitude determination, it was used the well-known QUEST algorithm which yields quick response with reduced computer resources. The algorithms are tested and qualified with actual data collected on the streets under controlled situations. For such street runaways, the experiment employs a solid-state magnetoresistive magnetometer and an IMU navigation block consisting of triads of accelerometers and gyros, with MEMS technology. A GPS receiver is used to record positional information. The collected measurements are processed through the developed algorithms, and comparisons are made for attitude determination using calibrated and noncalibrated data. The results show that the attitude accuracy reaches the requirements for real-time operation for satellite simulator platforms.

  3. Study on modulation amplitude stabilization method for PEM based on FPGA in atomic magnetometer

    Science.gov (United States)

    Wang, Qinghua; Quan, Wei; Duan, Lihong

    2017-10-01

    Atomic magnetometer which uses atoms as sensitive elements have ultra-high precision and has wide applications in scientific researches. The photoelastic modulation method based on photoelastic modulator (PEM) is used in the atomic magnetometer to detect the small optical rotation angle of a linearly polarized light. However, the modulation amplitude of the PEM will drift due to the environmental factors, which reduces the precision and long-term stability of the atomic magnetometer. Consequently, stabilizing the PEM's modulation amplitude is essential to precision measurement. In this paper, a modulation amplitude stabilization method for PEM based on Field Programmable Gate Array (FPGA) is proposed. The designed control system contains an optical setup and an electrical part. The optical setup is used to measure the PEM's modulation amplitude. The FPGA chip, with the PID control algorithm implemented in it, is used as the electrical part's micro controller. The closed loop control method based on the photoelastic modulation detection system can directly measure the PEM's modulation amplitude in real time, without increasing the additional optical devices. In addition, the operating speed of the modulation amplitude stabilization control system can be greatly improved because of the FPGA's parallel computing feature, and the PID control algorithm ensures flexibility to meet different needs of the PEM's modulation amplitude set values. The Modelsim simulation results show the correctness of the PID control algorithm, and the long-term stability of the PEM's modulation amplitude reaches 0.35% in a 3-hour continuous measurement.

  4. MgB{sub 2} magnetometer with a directly coupled pick-up loop

    Energy Technology Data Exchange (ETDEWEB)

    Portesi, C [Istituto Elettrotecnico Nazionale Galileo Ferraris, Strada delle Cacce 91, I-10135 Turin (Italy); Mijatovic, D [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Veldhuis, D [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Brinkman, A [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Monticone, E [Istituto Elettrotecnico Nazionale Galileo Ferraris, Strada delle Cacce 91, I-10135 Turin (Italy); Gonnelli, R S [INFM, Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy)

    2006-05-15

    In this work, we show the results obtained in the fabrication and characterization of an MgB{sub 2} magnetometer with a directly coupled pick-up loop. We used an all in situ technique for fabricating magnesium diboride films, which consists of the co-evaporation of B and Mg by means of an e-gun and a resistive heater respectively. Consequently, we realized the superconducting device, which incorporates two nanobridges as weak links in a superconducting loop. The nanobridges were realized by focused ion beam milling; they were 240 nm wide and had a critical current density of 10{sup 7} A cm{sup -2}. The magnetometer was characterized at different temperatures and also measurements of the noise levels have been performed. The device shows Josephson quantum interference up to 20 K and the calculated effective area at low temperatures was 0.24 mm{sup 2}. The transport properties of the magnetometer allow determining fundamental materials properties of the MgB{sub 2} thin films, such as the penetration depth.

  5. MgB2 magnetometer with a directly coupled pick-up loop

    Science.gov (United States)

    Portesi, C.; Mijatovic, D.; Veldhuis, D.; Brinkman, A.; Monticone, E.; Gonnelli, R. S.

    2006-05-01

    In this work, we show the results obtained in the fabrication and characterization of an MgB2 magnetometer with a directly coupled pick-up loop. We used an all in situ technique for fabricating magnesium diboride films, which consists of the co-evaporation of B and Mg by means of an e-gun and a resistive heater respectively. Consequently, we realized the superconducting device, which incorporates two nanobridges as weak links in a superconducting loop. The nanobridges were realized by focused ion beam milling; they were 240 nm wide and had a critical current density of 107 A cm-2. The magnetometer was characterized at different temperatures and also measurements of the noise levels have been performed. The device shows Josephson quantum interference up to 20 K and the calculated effective area at low temperatures was 0.24 mm2. The transport properties of the magnetometer allow determining fundamental materials properties of the MgB2 thin films, such as the penetration depth.

  6. The MAGIC of CINEMA: first in-flight science results from a miniaturised anisotropic magnetoresistive magnetometer

    Science.gov (United States)

    Archer, M. O.; Horbury, T. S.; Brown, P.; Eastwood, J. P.; Oddy, T. M.; Whiteside, B. J.; Sample, J. G.

    2015-06-01

    We present the first in-flight results from a novel miniaturised anisotropic magnetoresistive space magnetometer, MAGIC (MAGnetometer from Imperial College), aboard the first CINEMA (CubeSat for Ions, Neutrals, Electrons and MAgnetic fields) spacecraft in low Earth orbit. An attitude-independent calibration technique is detailed using the International Geomagnetic Reference Field (IGRF), which is temperature dependent in the case of the outboard sensor. We show that the sensors accurately measure the expected absolute field to within 2% in attitude mode and 1% in science mode. Using a simple method we are able to estimate the spacecraft's attitude using the magnetometer only, thus characterising CINEMA's spin, precession and nutation. Finally, we show that the outboard sensor is capable of detecting transient physical signals with amplitudes of ~ 20-60 nT. These include field-aligned currents at the auroral oval, qualitatively similar to previous observations, which agree in location with measurements from the DMSP (Defense Meteorological Satellite Program) and POES (Polar-orbiting Operational Environmental Satellites) spacecraft. Thus, we demonstrate and discuss the potential science capabilities of the MAGIC instrument onboard a CubeSat platform.

  7. Comparison of Vertical Drifts of ISR and Magnetometer Data Measurements at the Magnetic Equator

    Science.gov (United States)

    Condor P, P. J.

    2014-12-01

    We compare vertical drifts measured with the Jicamarca incoherent scatter radar (ISR) and drifts estimated from magnetometer data applying a Neural Network data processing technique. For the application of the Neural Network (NN) method, we use the magnitude of the horizontal (H) component of the magnetic field measured with magnetometers at Jicamarca and Piura (Peru). The data was collected between the years 2002 and 2013. In training the NN we use the difference between the magnitudes of the horizontal components (dH) measured at JRO (placed at the magnetic equator) and Piura (displaced 5° away). Additional parameters used are F10.7 and Ap indexes. The estimates obtained with the NN procedure are very good. We have an RMS error of 3.7 m/s using dH as an input of the NN while the error is 3.9 m/s when we use the component H of JRO as an input. The results are validated using the set of vertical drifts observations collected with the Jicamarca incoherent scatter radar. The estimated drifts can be accessed using the following website: http://jro.igp.gob.pe/driftnn. In the poster, we show the comparison of vertical drifts from 2002 to 2013 where we discuss the agreement between magnetometer and ISR data.

  8. Combined spacecraft orbit and attitude control through extended Kalman filtering of magnetometer, gyro, and GPS measurements

    Directory of Open Access Journals (Sweden)

    Tamer Mekky Ahmed Habib

    2014-06-01

    Full Text Available The main goal of this research is to establish spacecraft orbit and attitude control algorithms based on extended Kalman filter which provides estimates of spacecraft orbital and attitude states. The control and estimation algorithms must be capable of dealing with the spacecraft conditions during the detumbling and attitude acquisition modes of operation. These conditions are characterized by nonlinearities represented by large initial attitude angles, large initial angular velocities, large initial attitude estimation error, and large initial position estimation error. All of the developed estimation and control algorithms are suitable for application to the next Egyptian scientific satellite, EGYPTSAT-2. The parameters of the case-study spacecraft are similar but not identical to the former Egyptian satellite EGYPTSAT-1. This is done because the parameters of EGYPTSAT-2 satellite have not been consolidated yet. The sensors utilized are gyro, magnetometer, and GPS. Gyro and magnetometer are utilized to provide measurements for the estimates of spacecraft attitude state vector where as magnetometer and GPS are utilized to provide measurements for the estimates of spacecraft orbital state vector.

  9. Spherical proton emitters

    International Nuclear Information System (INIS)

    Berg, S.; Semmes, P.B.; Nazarewicz, W.

    1997-01-01

    Various theoretical approaches to proton emission from spherical nuclei are investigated, and it is found that all the methods employed give very similar results. The calculated decay widths are found to be qualitatively insensitive to the parameters of the proton-nucleus potential, i.e., changing the potential parameters over a fairly large range typically changes the decay width by no more than a factor of ∼3. Proton half-lives of observed heavy proton emitters are, in general, well reproduced by spherical calculations with the spectroscopic factors calculated in the independent quasiparticle approximation. The quantitative agreement with experimental data obtained in our study requires that the parameters of the proton-nucleus potential be chosen carefully. It also suggests that deformed proton emitters will provide invaluable spectroscopic information on the angular momentum decomposition of single-proton orbitals in deformed nuclei. copyright 1997 The American Physical Society

  10. Proton therapy physics

    CERN Document Server

    2012-01-01

    Proton Therapy Physics goes beyond current books on proton therapy to provide an in-depth overview of the physics aspects of this radiation therapy modality, eliminating the need to dig through information scattered in the medical physics literature. After tracing the history of proton therapy, the book summarizes the atomic and nuclear physics background necessary for understanding proton interactions with tissue. It describes the physics of proton accelerators, the parameters of clinical proton beams, and the mechanisms to generate a conformal dose distribution in a patient. The text then covers detector systems and measuring techniques for reference dosimetry, outlines basic quality assurance and commissioning guidelines, and gives examples of Monte Carlo simulations in proton therapy. The book moves on to discussions of treatment planning for single- and multiple-field uniform doses, dose calculation concepts and algorithms, and precision and uncertainties for nonmoving and moving targets. It also exami...

  11. Proton solvation and proton transfer in chemical and electrochemical processes

    International Nuclear Information System (INIS)

    Lengyel, S.; Conway, B.E.

    1983-01-01

    This chapter examines the proton solvation and characterization of the H 3 O + ion, proton transfer in chemical ionization processes in solution, continuous proton transfer in conductance processes, and proton transfer in electrode processes. Topics considered include the condition of the proton in solution, the molecular structure of the H 3 O + ion, thermodynamics of proton solvation, overall hydration energy of the proton, hydration of H 3 O + , deuteron solvation, partial molal entropy and volume and the entropy of proton hydration, proton solvation in alcoholic solutions, analogies to electrons in semiconductors, continuous proton transfer in conductance, definition and phenomenology of the unusual mobility of the proton in solution, solvent structure changes in relation to anomalous proton mobility, the kinetics of the proton-transfer event, theories of abnormal proton conductance, and the general theory of the contribution of transfer reactions to overall transport processes

  12. Study of proton radioactivities

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Back, B.B.; Henderson, D.J. [and others

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  13. Optimizations of spin-exchange relaxation-free magnetometer based on potassium and rubidium hybrid optical pumping

    International Nuclear Information System (INIS)

    Fang, Jiancheng; Wang, Tao; Li, Yang; Zhang, Hong; Zou, Sheng

    2014-01-01

    The hybrid optical pumping atomic magnetometers have not realized its theoretical sensitivity, the optimization is critical for optimal performance. The optimizations proposed in this paper are suitable for hybrid optical pumping atomic magnetometer, which contains two alkali species. To optimize the parameters, the dynamic equations of spin evolution with two alkali species were solved, whose steady-state solution is used to optimize the parameters. The demand of the power of the pump beam is large for hybrid optical pumping. Moreover, the sensitivity of the hybrid optical pumping magnetometer increases with the increase of the power density of the pump beam. The density ratio between the two alkali species is especially important for hybrid optical pumping magnetometer. A simple expression for optimizing the density ratio is proposed in this paper, which can help to determine the mole faction of the alkali atoms in fabricating the hybrid cell before the cell is sealed. The spin-exchange rate between the two alkali species is proportional to the saturated density of the alkali vapor, which is highly dependent on the temperature of the cell. Consequently, the sensitivity of the hybrid optical pumping magnetometer is dependent on the temperature of the cell. We proposed the thermal optimization of the hybrid cell for a hybrid optical pumping magnetometer, which can improve the sensitivity especially when the power of the pump beam is low. With these optimizations, a sensitivity of approximately 5 fT/Hz 1/2 is achieved with gradiometer arrangement

  14. The QuakeFinder Magnetometer Network - a Platform for Earth and Space Science Research

    Science.gov (United States)

    Bleier, T.; Kappler, K. N.; Schneider, D.

    2016-12-01

    QuakeFinder (QF) is a humanitarian research and development project attempting to characterize earth-emitting electromagnetic (EM) signals as potential precursors to earthquakes. Beginning in 2005, QF designed, built, deployed and now maintains an array of 165 remote monitoring stations in 6 countries (US/California, Taiwan, Greece, Indonesia, Peru and Chile). Having amassed approximately 70 TB of data and greater than 140 earthquakes (M4+), QF is focused on the data analysis and signal processing algorithms in our effort to enable a forecasting capability. QF's autonomous stations, located along major fault lines, collect and transmit electromagnetic readings from 3-axis induction magnetometers and positive/negative ion sensors, a geophone, as well as various station health status and local conditions. The induction magnetometers, oriented N-S,E-W and vertically, have a 40 nT range and 1 pT sensitivity. Data is continuously collected at 50 samples/sec (sps), GPS time-stamped and transmitted, primarily through cell phone networks, to our data center in Palo Alto, California. The induction magnetometers routinely detect subtle geomagnetic and ionospheric disturbances as observed worldwide. QF seeks to make available both historic data and the array platform to strategic partners in the EM-related research and operation fields. The QF system will be described in detail with examples of local and regional geomagnetic activity. The stations are robust and will be undergoing a system-level upgrade in the near future. Domestically, QF maintains a 98% `up time' among the 120 stations in California while internationally our metric is typically near 80%. Irregular cell phone reception is chief among the reasons for outages although little data has been lost as the stations can store up to 90 days of data. These data are retrieved by QF personnel or, when communication is reestablished, the QF data ingest process automatically updates the database. Planned station upgrades

  15. Magnetometer Data in the Classroom as a part of the NASA THEMIS Satellite Mission

    Science.gov (United States)

    Peticolas, L. M.; Bean, J.; Walker, A.

    2011-12-01

    The NASA-funded THEMIS mission was designed to determine the onset time and location of magnetic substorms of Earth's space environment, a prerequisite to understanding space weather. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. he Geomagnetic Event Observation Network by Students (GEONS) project was the flagship, formal education component of the E/PO program. With the placement of magnetometers in the proximity of rural schools throughout the country, middle and high school teachers along with their students benefited from the opportunity to work with 'real-time' data and participated in hands-on space science activities. Particular attention was paid to placing the magnetometer stations at schools in rural communities whose students were traditionally underserved and underrepresented in the sciences. The project offered to the teachers of these students long-term professional development opportunities that centered around THEMIS-related space science and the magnetometer data. The THEMIS E/PO final evaluation report for the main phase of the THEMIS mission covered the period from 2003-2009, describing the impact of this program such as this program placed magnetometers sites at 13 rural, underserved schools/communities, two-fifths of which are on tribal lands; and provided intensive professional development for 20 teachers from 2004 through 2009. A core group of eight teachers estimated reaching more than 2,720 students with THEMIS-related materials/ideas. 75% of these students are minorities in science. Core teachers provided evidence of the project's positive impact on students' attitudes toward science and their choices for courses that position them for STEM-related careers. Core teachers reported sharing THEMIS-related materials/ideas with 275 colleagues. The NewsHour with Jim Lehrer featured the Petersburg, Alaska site potentially reaching more than 5 million viewers in two airings, according to Nielsen

  16. Working group report on the structure of the proton

    International Nuclear Information System (INIS)

    Badelek, B.; Vogt, A.; Gehrmann, T.; Martin, A.D.; Lancaster, M.

    1996-03-01

    We summarize the developments on the structure of the proton that we studied at the Workshop on HERA physics that was held in Durham in September 1995. We survey the latest structure function data; we overview the QCD interpretations of the measurements of the structure functions and of final state processes; we discuss charm production and the spin properties of the proton. (orig.)

  17. Report on gravity measurements and replacement of an unmanned magnetometer in the Sor Rondane Mountains, Eastern Dronning Maud Land, 2013 (JARE-55

    Directory of Open Access Journals (Sweden)

    Yusuke Suganuma

    2014-11-01

    Full Text Available Gravity measurements, replacement of the unmanned magnetometer, and a reconnaissance flight to the Belgica Mountains were carried out in the Sor Rondane Mountains as a part of the 55 th Japanese Antarctic Research Expedition (JARE-55. The field party comprised two geodesists, one geomorphologists, and one magnetospheric scientist. The Belgian Antarctic Research Expedition (BELARE and International Polar Foundation (IPF supported this field expedition. Dronning Maud Land Air Network (DROMLAN provided airborne access from Cape Town, South Africa to the Sor Rondane Mountains via Novolazarevskaya Airbase. The survey areas of this field expedition are the central parts of the Sor Rondane Mountains and the Belgica Mountains. This report summarizes the field expedition in terms of operations, logistics, and weather observations.

  18. Measurement of the terrestrial magnetic field and its anomalies

    International Nuclear Information System (INIS)

    Duret, D.

    1994-01-01

    After a presentation of the terrestrial magnetic field and its various anomalies, the different types of magnetometers commonly used are reviewed with their characteristics and performances: scalar magnetometers (free precession and continuous polarization proton magnetometers, dynamic polarization proton magnetometers, optical pumping magnetometers, electronic resonance scalar magnetometers (without pumping)); vectorial magnetometers (flux gate magnetometers, induction magnetometers, suspended magnet magnetometers, superconducting magnetometers, integrated magnetometers, resonance directional magnetometers). The magnetometry market and applications are discussed. 20 figs., 9 tabs., 72 refs

  19. Measurement of the terrestrial magnetic field and its anomalies; Mesures du champ magnetique terrestre et de ses anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Duret, D.

    1994-12-31

    After a presentation of the terrestrial magnetic field and its various anomalies, the different types of magnetometers commonly used are reviewed with their characteristics and performances: scalar magnetometers (free precession and continuous polarization proton magnetometers, dynamic polarization proton magnetometers, optical pumping magnetometers, electronic resonance scalar magnetometers (without pumping)); vectorial magnetometers (flux gate magnetometers, induction magnetometers, suspended magnet magnetometers, superconducting magnetometers, integrated magnetometers, resonance directional magnetometers). The magnetometry market and applications are discussed. 20 figs., 9 tabs., 72 refs.

  20. Proton-Proton and Proton-Antiproton Colliders

    CERN Document Server

    Scandale, Walter

    2014-01-01

    In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  1. Technical procedures for aeromagnetic surveys in Antarctica during the Italian expeditions (1988-1992

    Directory of Open Access Journals (Sweden)

    D. Damaske

    1994-06-01

    Full Text Available For most of Antarctica, the geophysical data now available are those of aeromagnetic surveys performed there from 1950 to 1960. Until 1984, the inaccurate positioning and insufficient monitoring of geomagnetic time variations allowed the investigation of the geomagnetic residual field only along profiles. The Ganovex IV aeromagnetic survey, performed by BGR-USGS over the Ross Sea and the Northern Victoria Land, and the geophysical investigations of BAS on the Southern Antarctic peninsula and the Ronne ice shelf region corresponds to the recent advancement of these techniques in Antarctica. The first experiments of aeromagnetic measurements, during the Italian expeditions in Antarctica were made during the 1988-1989 field season. Some geomagnetic helicopter borne profiles were accomplished with a Proton Precession Magnetometer (PPM in the Terra Nova Bay-Gerlache Inlet area. In the 1989-1990 ItaliAntartide expedition some profiles were flown over the suture between the Wilson and Bower terranes, in Northern Victoria Land. During the 1991-1992 expedition, in cooperation with researchers of BGR (Bundesanstalt fur Geowissenschaften und Rohstoffe of Hannover, the GITARA I (German ITalian Aeromagnetic Rescarch Antarctica program, as part of the LIRA (Litospheric Investigation in the Ross Sea Area project, was carried out. The investigated area lies between the latitudes 74°18' S and 75°18' S and the longitudes 160°30' E and 164°30'E and it corresponds to a portion of the North Victoria Land, located between the Eisenhower Range and the, DrygaIski Ice Tongue. The survey was made with a Cesium vapour magnetometer. The positioning system was of the “Range-Range” type, it consisted of three transmitters (beacons, installed inside the investigated area and located with GPS measurements. The line spacing was 4.4 km, with tie lines every 22 km. The survey covered an area of 6500 km2 . Four PPM base stations for the determination of the time variation

  2. Proton Fast Ignition

    International Nuclear Information System (INIS)

    Key, M H; Freeman, R R; Hatchett, S P; MacKinnon, A J; Patel, P K; Snavely, R A; Stephens, R B

    2006-04-01

    Fast ignition (FI) by a laser generated ballistically focused proton beam is a more recently proposed alternative to the original concept of FI by a laser generated beam of relativistic electrons. It has potential advantages in less complex energy transport into dense plasma. Recent successful target heating experiments motivate further investigation of the feasibility of proton fast ignition. The concept, the physics and characteristics of the proton beams, the recent experimental work on focusing of the beams and heating of solid targets and the overall prospects for proton FI are discussed

  3. The Storage Ring Proton EDM Experiment

    Science.gov (United States)

    Semertzidis, Yannis; Storage Ring Proton EDM Collaboration

    2014-09-01

    The storage ring pEDM experiment utilizes an all-electric storage ring to store ~1011 longitudinally polarized protons simultaneously in clock-wise and counter-clock-wise directions for 103 seconds. The radial E-field acts on the proton EDM for the duration of the storage time to precess its spin in the vertical plane. The ring lattice is optimized to reduce intra-beam scattering, increase the statistical sensitivity and reduce the systematic errors of the method. The main systematic error is a net radial B-field integrated around the ring causing an EDM-like vertical spin precession. The counter-rotating beams sense this integrated field and are vertically shifted by an amount, which depends on the strength of the vertical focusing in the ring, thus creating a radial B-field. Modulating the vertical focusing at 10 kHz makes possible the detection of this radial B-field by a SQUID-magnetometer (SQUID-based BPM). For a total number of n SQUID-based BPMs distributed around the ring the effectiveness of the method is limited to the N = n /2 harmonic of the background radial B-field due to the Nyquist sampling theorem limit. This limitation establishes the requirement to reduce the maximum radial B-field to 0.1-1 nT everywhere around the ring by layers of mu-metal and aluminum vacuum tube. The metho's sensitivity is 10-29 e .cm , more than three orders of magnitude better than the present neutron EDM experimental limit, making it sensitive to SUSY-like new physics mass scale up to 300 TeV.

  4. Proton decay: spectroscopic probe beyond the proton drip line

    International Nuclear Information System (INIS)

    Seweryniak, D; Davids, C N; Robinson, A; Woods, P J; Blank, B; Carpenter, M P; Davinson, T; Freeman, S J; Hammond, N; Hoteling, N; Janssens, R V F; Khoo, T L; Liu, Z; Mukherjee, G; Shergur, J; Sinha, S; Sonzogni, A A; Walters, W B; Woehr, A

    2005-01-01

    Proton decay has been transformed in recent years from an exotic phenomenon into a powerful spectroscopic tool. The frontiers of experimental and theoretical proton-decay studies will be reviewed. Different aspects of proton decay will be illustrated with recent results on the deformed proton emitter 135 Tb, the odd-odd deformed proton emitter 130 Eu, the complex fine structure in the odd-odd 146 Tm nucleus and on excited states in the transitional proton emitter 145 Tm

  5. Review of inelastic proton-proton reactions

    CERN Document Server

    Morrison, Douglas Robert Ogston

    1973-01-01

    The most important new results on inelastic proton-proton scattering obtained with the new machines, I.S.R. and N.A.L., are: (1) The inelastic cross-section increases monotonically with energy from threshold to 1500 GeV/c. Above 6 GeV/c the energy variation has a s /sup +0.04/ behaviour. (2) Scaling is observed at I.S.R. energies in pion production. Confirmation is obtained of the hypothesis of limiting fragmentation. (3) The results are in general, consistent with the two-component model-one class of events being produced by diffraction dissociation and the other by a short-range-order process (e.g. the multiperipheral model). (4) There are indications that the protons have a granular structure; this from observation of secondaries of large transverse momenta. (33 refs).

  6. Studies of Polar Current Systems Using the IMS Scandinavian Magnetometer Array

    Science.gov (United States)

    Untiedt, J.; Baumjohann, W.

    1993-09-01

    As a contribution to the International Magnetospheric Study (IMS, 1976 1979) a two-dimensional array of 42 temporary magnetometer stations was run in Scandinavia, supplementary to the permanent observatories and concentrated in the northern part of the region. This effort aimed at the time-dependent (periods above about 100 s) determination of the two-dimensional structure of substorm-related magnetic fields at the Earth's surface with highest reasonable spatial resolution (about 100 km, corresponding to the height of the ionosphere) near the footpoints of field-aligned electric currents that couple the disturbed magnetosphere to the ionosphere at auroral latitudes. It has been of particular advantage for cooperative studies that not only simultaneous data were available from all-sky cameras, riometers, balloons, rockets, and satellites, but also from the STARE radar facility yielding colocated two-dimensional ionospheric electric field distributions. In many cases it therefore was possible to infer the three-dimensional regional structure of substorm-related ionospheric current systems. The first part of this review outlines the basic relationships and methods that have been used or have been developed for such studies. The second short part presents typical equivalent current patterns observed by the magnetometer array in the course of substorms. Finally we review main results of studies that have been based on the magnetometer array observations and on additional data, omitting studies on geomagnetic pulsations. These studies contributed to a clarification of the nature of auroral electrojets including the Harang discontinuity and of ionospheric current systems related to auroral features such as the break-up at midnight, the westward traveling surge, eastward drifting omega bands, and spirals.

  7. Protons and how they are transported by proton pumps

    DEFF Research Database (Denmark)

    Buch-Pedersen, Morten Jeppe; Pedersen, Bjørn Panyella; Nissen, Poul

    2008-01-01

    molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological...... proton pumps emerge. Most notably, the minimal pumping apparatus of all pumps consists of a central proton acceptor/donor, a positively charged residue to control pK (a) changes of the proton acceptor/donor, and bound water molecules to facilitate rapid proton transport along proton wires....

  8. A summary of the results from the UCLA OGO-5 fluxgate magnetometer

    Science.gov (United States)

    Coleman, P. J., Jr.; Russell, C. T.

    1973-01-01

    The OGO-5 fluxgate magnetometer experiment (E-14) was designed to measure the vector magnetic field over the full range of the OGO-5 orbit. Thus, it had a dynamic range of + or - 64,000 gamma yet it maintained a precision of + or - 1/16 gamma at all times. This enabled a broad spectrum of problems to be attached. Studies of the magnetospheric waves, currents, waves-particle interactions, pitch angle distributions and wave normal directions were made. The structure of the magnetopause, the magnetotail, and bow shock were probed, waves and discontinuities in the solar wind were examined and the various phases of substorms were examined in depth.

  9. Elimination of the induced current error in magnetometers using superconducting flux transformers

    International Nuclear Information System (INIS)

    Dummer, D.; Weyhmann, W.

    1987-01-01

    The changing magnetization of a sample in a superconducting flux transformer coupled magnetometer induces a current in the transformer which in turn changes the field at the sample. This ''image'' field and the error caused by it can be eliminated by sensing the current in the loop and nulling it by feedback through a mutual inductance. We have tested the technique on the superconducting transition of indium in an applied magnetic field and shown that the observed width of the transition is greatly reduced by maintaining zero current in the flux transformer

  10. Geospace Science from Ground-based Magnetometer Arrays: Advances in Sensors, Data Collection, and Data Integration

    Science.gov (United States)

    Mann, Ian; Chi, Peter

    2016-07-01

    Networks of ground-based magnetometers now provide the basis for the diagnosis of magnetic disturbances associated with solar wind-magnetosphere-ionosphere coupling on a truly global scale. Advances in sensor and digitisation technologies offer increases in sensitivity in fluxgate, induction coil, and new micro-sensor technologies - including the promise of hybrid sensors. Similarly, advances in remote connectivity provide the capacity for truly real-time monitoring of global dynamics at cadences sufficient for monitoring and in many cases resolving system level spatio-temporal ambiguities especially in combination with conjugate satellite measurements. A wide variety of the plasmaphysical processes active in driving geospace dynamics can be monitored based on the response of the electrical current system, including those associated with changes in global convection, magnetospheric substorms and nightside tail flows, as well as due to solar wind changes in both dynamic pressure and in response to rotations of the direction of the IMF. Significantly, any changes to the dynamical system must be communicated by the propagation of long-period Alfven and/or compressional waves. These wave populations hence provide diagnostics for not only the energy transport by the wave fields themselves, but also provide a mechanism for diagnosing the structure of the background plasma medium through which the waves propagate. Ultra-low frequency (ULF) waves are especially significant in offering a monitor for mass density profiles, often invisible to particle detectors because of their very low energy, through the application of a variety of magneto-seismology and cross-phase techniques. Renewed scientific interest in the plasma waves associated with near-Earth substorm dynamics, including magnetosphere-ionosphere coupling at substorm onset and their relation to magnetotail flows, as well the importance of global scale ultra-low frequency waves for the energisation, transport

  11. Note: Commercial SQUID magnetometer-compatible NMR probe and its application for studying a quantum magnet.

    Science.gov (United States)

    Vennemann, T; Jeong, M; Yoon, D; Magrez, A; Berger, H; Yang, L; Živković, I; Babkevich, P; Rønnow, H M

    2018-04-01

    We present a compact nuclear magnetic resonance (NMR) probe which is compatible with a magnet of a commercial superconducting quantum interference device magnetometer and demonstrate its application to the study of a quantum magnet. We employ trimmer chip capacitors to construct an NMR tank circuit for low temperature measurements. Using a magnetic insulator MoOPO 4 with S = 1/2 (Mo 5+ ) as an example, we show that the T-dependence of the circuit is weak enough to allow the ligand-ion NMR study of magnetic systems. Our 31 P NMR results are compatible with previous bulk susceptibility and neutron scattering experiments and furthermore reveal unconventional spin dynamics.

  12. Note: Readout of a micromechanical magnetometer for the ITER fusion reactor

    International Nuclear Information System (INIS)

    Rimminen, H.; Kyynäräinen, J.

    2013-01-01

    We present readout instrumentation for a MEMS magnetometer, placed 30 m away from the MEMS element. This is particularly useful when sensing is performed in high-radiation environment, where the semiconductors in the readout cannot survive. High bandwidth transimpedance amplifiers are used to cancel the cable capacitances of several nanofarads. A frequency doubling readout scheme is used for crosstalk elimination. Signal-to-noise ratio in the range of 60 dB was achieved and with sub-percent nonlinearity. The presented instrument is intended for the steady-state magnetic field measurements in the ITER fusion reactor.

  13. Note: Commercial SQUID magnetometer-compatible NMR probe and its application for studying a quantum magnet

    Science.gov (United States)

    Vennemann, T.; Jeong, M.; Yoon, D.; Magrez, A.; Berger, H.; Yang, L.; Živković, I.; Babkevich, P.; Rønnow, H. M.

    2018-04-01

    We present a compact nuclear magnetic resonance (NMR) probe which is compatible with a magnet of a commercial superconducting quantum interference device magnetometer and demonstrate its application to the study of a quantum magnet. We employ trimmer chip capacitors to construct an NMR tank circuit for low temperature measurements. Using a magnetic insulator MoOPO4 with S = 1/2 (Mo5+) as an example, we show that the T-dependence of the circuit is weak enough to allow the ligand-ion NMR study of magnetic systems. Our 31P NMR results are compatible with previous bulk susceptibility and neutron scattering experiments and furthermore reveal unconventional spin dynamics.

  14. Is light narrowing possible with dense-vapor paraffin coated cells for atomic magnetometers?

    Science.gov (United States)

    Han, Runqi; Balabas, Mikhail; Hovde, Chris; Li, Wenhao; Roig, Hector Masia; Wang, Tao; Wickenbrock, Arne; Zhivun, Elena; You, Zheng; Budker, Dmitry

    2017-12-01

    We investigated the operation of an all-optical rubidium-87 atomic magnetometer with amplitude-modulated light. To study the suppression of spin-exchange relaxation, three schemes of pumping were implemented with room-temperature and heated paraffin coated vacuum cells. Efficient pumping and accumulation of atoms in the F=2 ground state were obtained. However, the sought-for narrowing of the resonance lines has not been achieved. A theoretical analysis of the polarization degree is presented to illustrate the absence of light narrowing due to radiation trapping at high temperature.

  15. Giving Protons a Boost

    CERN Multimedia

    2004-01-01

    The first of LHC's superconducting radio-frequency cavity modules has passed its final test at full power in the test area of building SM18. These modules carry an oscillating electric field that will accelerate protons around the LHC ring and help maintain the stability of the proton beams.

  16. On the proton decay

    International Nuclear Information System (INIS)

    Fonda, L.; Ghirardi, G.C.; Weber, T.

    1983-07-01

    The problem of the proton decay is considered taking into account that in actual experiments there is an interaction of the proton with its environment which could imply an increase of its theoretical lifetime. It is seen that, by application of the time-energy uncertainty relation, no prolongation of the lifetime is obtained in this case. (author)

  17. Gas magnetometer

    Science.gov (United States)

    Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

    2016-05-03

    Measurement of a precessional rate of a gas, such as an alkali gas, in a magnetic field is made by promoting a non-uniform precession of the gas in which substantially no net magnetic field affects the gas during a majority of the precession cycle. This allows sensitive gases that would be subject to spin-exchange collision de-phasing to be effectively used for extremely sensitive measurements in the presence of an environmental magnetic field such as the Earth's magnetic field.

  18. PS proton source

    CERN Multimedia

    1959-01-01

    The first proton source used at CERN's Proton Synchrotron (PS) which started operation in 1959. This is CERN's oldest accelerator still functioning today (2018). It is part of the accelerator chain that supplies proton beams to the Large Hadron Collider. The source is a Thonemann type. In order to extract and accelerate the protons at high energy, a high frequency electrical field is used (140Mhz). The field is transmitted by a coil around a discharge tube in order to maintain the gas hydrogen in an ionised state. An electrical field pulse, in the order of 15kV, is then applied via an impulse transformer between anode and cathode of the discharge tube. The electrons and protons of the plasma formed in the ionised gas in the tube, are then separated. Currents in the order of 200mA during 100 microseconds have benn obtained with this type of source.

  19. Investigation of Global Lightning using Schumann Resonances measured by High Frequency Induction Coil Magnetometers in the UK

    Science.gov (United States)

    Beggan, C.; Gabillard, T.; Swan, A.; Flower, S. M.; Thomson, A. W.

    2012-12-01

    In June 2012, the British Geological Survey Geomagnetism team installed two high frequency (100 Hz) induction coil magnetometers at the Eskdalemuir Observatory, in the Scottish Borders of the United Kingdom. The induction coils permit us to measure the very rapid changes of the magnetic field. The Eskdalemuir Observatory is one of the longest running geophysical sites in the UK (beginning operation in 1904) and is located in a rural valley with a quiet magnetic environment. The data output from the induction coils are digitized and logged onsite before being collected once per hour and sent to the Edinburgh office via the Internet. We intend to run the coils as a long term experiment. We present initial results from first five months of data. Analysis of spectrograms and power spectral density plots in the frequency band of 3-40 Hz from the coils show diffuse bands of peak power around 7.8 Hz, 14.3 Hz, 20.8 Hz, 27 Hz, 34 Hz and 39Hz related to the global Schumann resonances. We also detect a strong narrow peak at 25 Hz, which is a harmonic of the UK electrical power system. There are a number of features in the data that we wish to investigate, including the diurnal and seasonal variation of the Schumann resonances. For example, it has been suggested that lightning activity is related to climate variability in the tropics and that perhaps Madden-Julian Oscillations (MJO) or El Niño Southern Oscillation (ENSO)-like correlations are detectable within the data. On longer timescales, we will look for solar cycle and climate variations. We also wish to note that the data is freely available on request to the community.

  20. Proton-proton colliding beam facility ISABELLE

    International Nuclear Information System (INIS)

    Hahn, H.

    1980-01-01

    This paper attempts to present the status of the ISABELLE construction project, which has the objective of building a 400 + 400 GeV proton colliding beam facility. The major technical features of the superconducting accelerators with their projected performance are described. Progress made so far, difficulties encountered, and the program until completion in 1986 is briefly reviewed

  1. Effect of second harmonic in pulse-width-modulation-based DAC for feedback of digital fluxgate magnetometer

    Science.gov (United States)

    Belyayev, Serhiy; Ivchenko, Nickolay

    2018-04-01

    Digital fluxgate magnetometers employ processing of the measured pickup signal to produce the value of the compensation current. Using pulse-width modulation with filtering for digital to analog conversion is a convenient approach, but it can introduce an intrinsic source of nonlinearity, which we discuss in this design note. A code shift of one least significant bit changes the second harmonic content of the pulse train, which feeds into the pick-up signal chain despite the heavy filtering. This effect produces a code-dependent nonlinearity. This nonlinearity can be overcome by the specific design of the timing of the pulse train signal. The second harmonic is suppressed if the first and third quarters of the excitation period pulse train are repeated in the second and fourth quarters. We demonstrate this principle on a digital magnetometer, achieving a magnetometer noise level corresponding to that of the sensor itself.

  2. Temperature-dependent performance of all-NbN DC-SQUID magnetometers

    Science.gov (United States)

    Liu, Quansheng; Wang, Huiwu; Zhang, Qiyu; Wang, Hai; Peng, Wei; Wang, Zhen

    2017-05-01

    Integrated NbN direct current superconducting quantum interference device (DC-SQUID) magnetometers were developed based on high-quality epitaxial NbN/AlN/NbN Josephson junctions for SQUID applications operating at high temperatures. We report the current-voltage and voltage-flux characteristics and the noise performance of the NbN DC-SQUIDs for temperatures ranging from 4.2 to 9 K. The critical current and voltage swing of the DC-SQUIDs decreased by 15% and 25%, respectively, as the temperature was increased from 4.2 to 9 K. The white flux noise of the DC-SQUID magnetometer at 1 kHz increased from 3.9 μΦ0/Hz1/2 at 4.2 K to 4.8 μΦ0/Hz1/2 at 9 K with 23% increase, corresponding to the magnetic field noise of 6.6 and 8.1 fT/Hz1/2, respectively. The results show that NbN DC-SQUIDs improve the tolerance of the operating temperatures and temperature fluctuations in SQUID applications.

  3. Counter electrojet features in the Brazilian sector: simultaneous observation by radar, digital sounder and magnetometers

    Directory of Open Access Journals (Sweden)

    C. M. Denardini

    2009-04-01

    Full Text Available In the present work we show new results regarding equatorial counter electrojet (CEJ events in the Brazilian sector, based on the RESCO radar, two set of fluxgate magnetometer systems and a digital sounder. RESCO radar is a 50 MHz backscatter coherent radar installed in 1998 at São Luís (SLZ, 2.33° S, 44.60° W, an equatorial site. The Digital sounder routinely monitors the electron density profile at the radar site. The magnetometer systems are fluxgate-type installed at SLZ and Eusébio (EUS, 03.89° S, 38.44° W. From the difference between the horizontal component of magnetic field at SLZ station and the same component at EUS (EEJ ground strength several cases of westward morning electrojet and its normal inversion to the eastward equatorial electrojet (EEJ have been observed. Also, the EEJ ground strength has shown some cases of CEJ events, which been detected with the RESCO radar too. Detection of these events were investigated with respect to their time and height of occurrence, correlation with sporadic E (Es layers at the same time, and their spectral characteristics as well as the radar echo power intensity.

  4. On determining fluxgate magnetometer spin axis offsets from mirror mode observations

    Science.gov (United States)

    Plaschke, Ferdinand; Narita, Yasuhito

    2016-09-01

    In-flight calibration of fluxgate magnetometers that are mounted on spacecraft involves finding their outputs in vanishing ambient fields, the so-called magnetometer offsets. If the spacecraft is spin-stabilized, then the spin plane components of these offsets can be relatively easily determined, as they modify the spin tone content in the de-spun magnetic field data. The spin axis offset, however, is more difficult to determine. Therefore, usually Alfvénic fluctuations in the solar wind are used. We propose a novel method to determine the spin axis offset: the mirror mode method. The method is based on the assumption that mirror mode fluctuations are nearly compressible such that the maximum variance direction is aligned to the mean magnetic field. Mirror mode fluctuations are typically found in the Earth's magnetosheath region. We introduce the method and provide a first estimate of its accuracy based on magnetosheath observations by the THEMIS-C spacecraft. We find that 20 h of magnetosheath measurements may already be sufficient to obtain high-accuracy spin axis offsets with uncertainties on the order of a few tenths of a nanotesla, if offset stability can be assumed.

  5. On determining fluxgate magnetometer spin axis offsets from mirror mode observations

    Directory of Open Access Journals (Sweden)

    F. Plaschke

    2016-09-01

    Full Text Available In-flight calibration of fluxgate magnetometers that are mounted on spacecraft involves finding their outputs in vanishing ambient fields, the so-called magnetometer offsets. If the spacecraft is spin-stabilized, then the spin plane components of these offsets can be relatively easily determined, as they modify the spin tone content in the de-spun magnetic field data. The spin axis offset, however, is more difficult to determine. Therefore, usually Alfvénic fluctuations in the solar wind are used. We propose a novel method to determine the spin axis offset: the mirror mode method. The method is based on the assumption that mirror mode fluctuations are nearly compressible such that the maximum variance direction is aligned to the mean magnetic field. Mirror mode fluctuations are typically found in the Earth's magnetosheath region. We introduce the method and provide a first estimate of its accuracy based on magnetosheath observations by the THEMIS-C spacecraft. We find that 20 h of magnetosheath measurements may already be sufficient to obtain high-accuracy spin axis offsets with uncertainties on the order of a few tenths of a nanotesla, if offset stability can be assumed.

  6. Demonstration of the SeptiStrand benthic microbial fuel cell powering a magnetometer for ship detection

    Science.gov (United States)

    Arias-Thode, Y. Meriah; Hsu, Lewis; Anderson, Greg; Babauta, Jerome; Fransham, Roy; Obraztsova, Anna; Tukeman, Gabriel; Chadwick, D. Bart

    2017-07-01

    The Navy has a need for monitoring conditions and gathering information in marine environments. Sensors can monitor and report environmental parameters and potential activities such as animal movements, ships, or personnel. However, there has to be a means to power these sensors. One promising enabling technology that has been shown to provide long-term power production in underwater environments is the benthic microbial fuel cells (BMFC). BMFCs are devices that generate energy by coupling bioanodes and biocathodes through an external energy harvester. Recent studies have demonstrated success for usage of BMFCs in powering small instruments and other devices on the seafloor over limited periods of time. In this effort, a seven-stranded BMFC linear array of 30 m was designed to power a seafloor magnetometer to detect passing ship movements through Pearl Harbor, Hawaii. The BMFC system was connected to a flyback energy harvesting circuit that charged the battery powering the magnetometer. The deployment was demonstrated the BMFC supplied power to the battery for approximately 38 days. This is the first large-scale demonstration system for usage of the SeptiStrand BMFC technology to power a relevant sensor.

  7. The fluxgate magnetometer of the BepiColombo Mercury Planetary Orbiter

    Science.gov (United States)

    Glassmeier, K.-H.; Auster, H.-U.; Heyner, D.; Okrafka, K.; Carr, C.; Berghofer, G.; Anderson, B. J.; Balogh, A.; Baumjohann, W.; Cargill, P.; Christensen, U.; Delva, M.; Dougherty, M.; Fornaçon, K.-H.; Horbury, T. S.; Lucek, E. A.; Magnes, W.; Mandea, M.; Matsuoka, A.; Matsushima, M.; Motschmann, U.; Nakamura, R.; Narita, Y.; O'Brien, H.; Richter, I.; Schwingenschuh, K.; Shibuya, H.; Slavin, J. A.; Sotin, C.; Stoll, B.; Tsunakawa, H.; Vennerstrom, S.; Vogt, J.; Zhang, T.

    2010-01-01

    The magnetometer (MAG) on the Mercury Planetary Orbiter (MPO) of the joint European-Japanese BepiColombo mission to planet Mercury is a low-noise, tri-axial, dual-sensor, digital fluxgate instrument with its sensors mounted on a 2.8-m-long boom. The primary MPO/MAG science objectives are to determine the spatial and temporal structure of the magnetic field in the Hermean system, in particular the structure and origin of the intrinsic magnetic field of Mercury. MPO/MAG has a dynamic measurement range of ±2000nT with a resolution of 2 pT during operation along the near-polar orbit of the MPO spacecraft around Mercury. MPO/MAG is designed to provide measurements with rates between 0.5 and 128 vectors/s. In cooperation with its sister magnetometer instrument, MMO/MGF on board the BepiColombo Mercury Magnetospheric Orbiter (MMO), MPO/MAG will be able to distinguish between temporal and spatial magnetic field variations in the magnetically closely coupled Hermean system.

  8. Development of fluxgate magnetometers and applications to the space science missions

    Science.gov (United States)

    Matsuoka, A.; Shinohara, M.; Tanaka, Y.-M.; Fujimoto, A.; Iguchi, K.

    2013-11-01

    Magnetic field is one of the essential physical parameters to study the space physics and evolution of the solar system. There are several methods to measure the magnetic field in the space by spacecraft and rockets. Fluxgate magnetometer has been most generally used out of them because it measures the vector field accurately and does not need much weight and power budgets. When we try more difficult missions such as multi-satellite observation, landing on the celestial body and exploration in the area of severe environment, we have to modify the magnetometer or develop new techniques to make the instrument adequate for those projects. For example, we developed a 20-bit delta-sigma analogue-to-digital converter for MGF-I on the BepiColombo MMO satellite, to achieve the wide-range (±2000 nT) measurement with good resolution in the high radiation environment. For further future missions, we have examined the digitalizing of the circuit, which has much potential to drastically reduce the instrument weight, power consumption and performance dependence on the temperature.

  9. Proton storage rings

    International Nuclear Information System (INIS)

    Rau, R.R.

    1978-04-01

    A discussion is given of proton storage ring beam dynamic characteristics. Topics considered include: (1) beam energy; (2) beam luminosity; (3) limits on beam current; (4) beam site; (5) crossing angle; (6) beam--beam interaction; (7) longitudinal instability; (8) effects of scattering processes; (9) beam production; and (10) high magnetic fields. Much of the discussion is related to the design parameters of ISABELLE, a 400 x 400 GeV proton---proton intersecting storage accelerator to be built at Brookhaven National Laboratory

  10. ATLAS Forward Proton Detector

    CERN Document Server

    Grieco, Chiara; The ATLAS collaboration

    2018-01-01

    The aim of the ATLAS Forward Proton (AFP) detector system is the measurement of protons scattered diffractively or electromagnetically at very small angles. The full two-arm setup was installed during the 2016/2017 EYETS. This allows measurements of processes with two forward protons: central diffraction, exclusive production, and two-photon processes. In 2017, AFP participated in the ATLAS high-luminosity data taking on the day-by-day basis. In addition, several special runs with reduced luminosity were taken. The poster will present the AFP detectors and the lessons learned from the last year operation and some performance from 2016 and 2017.

  11. Proton computed tomography

    International Nuclear Information System (INIS)

    Hanson, K.M.

    1978-01-01

    The use of protons or other heavy charged particles instead of x rays in computed tomography (CT) is explored. The results of an experimental implementation of proton CT are presented. High quality CT reconstructions are obtained at an average dose reduction factor compared with an EMI 5005 x-ray scanner of 10:1 for a 30-cm-diameter phantom and 3.5:1 for a 20-cm diameter. The spatial resolution is limited by multiple Coulomb scattering to about 3.7 mm FWHM. Further studies are planned in which proton and x-ray images of fresh human specimens will be compared. Design considerations indicate that a clinically useful proton CT scanner is eminently feasible

  12. Electron - proton colliders

    International Nuclear Information System (INIS)

    Wiik, B.H.

    1985-01-01

    Electron-proton storage rings allow us to study the interaction between the two basic constituents of matter, electrons and quarks at very short distances. Such machines were first discussed in connection with the ISR but the idea was abandoned because of the anticipated low counting rate. The interest in electron-proton storage rings was rekindeled by the discovery of large pointlike cross sections in lepton-hardon interactions and several/sup 2-15/ projects have been discussed during the past decade. However, despite a glorious past, which includes the discovery of quarks and neutral currents, and a multitude of proposals no electron-proton storage ring has ever been built. What we might learn by studying electron-proton collisions at high energies is discussed. After some brief comments on present proposals the proposed DESY ep project HERA is described as an example of how to realize such a machine

  13. Apparatus for proton radiography

    International Nuclear Information System (INIS)

    Martin, R.L.

    1976-01-01

    An apparatus for effecting diagnostic proton radiography of patients in hospitals comprises a source of negative hydrogen ions, a synchrotron for accelerating the negative hydrogen ions to a predetermined energy, a plurality of stations for stripping extraction of a radiography beam of protons, means for sweeping the extracted beam to cover a target, and means for measuring the residual range, residual energy, or percentage transmission of protons that pass through the target. The combination of information identifying the position of the beam with information about particles traversing the subject and the back absorber is performed with the aid of a computer to provide a proton radiograph of the subject. In an alternate embodiment of the invention, a back absorber comprises a plurality of scintillators which are coupled to detectors. 10 claims, 7 drawing figures

  14. Plant proton pumps

    DEFF Research Database (Denmark)

    Gaxiola, Roberto A.; Palmgren, Michael Gjedde; Schumacher, Karin

    2007-01-01

    Chemiosmotic circuits of plant cells are driven by proton (H+) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react...

  15. Inauguration of Proton Synchrotron

    CERN Multimedia

    1960-01-01

    On 5 February 1960, the Proton Synchrotron (PS) was formally inaugurated. The great Danish physicist, Niels Bohr, releases a bottle of champagne against a shielding block to launch the PS on its voyage in physics.

  16. Proton beam therapy facility

    International Nuclear Information System (INIS)

    1984-01-01

    It is proposed to build a regional outpatient medical clinic at the Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois, to exploit the unique therapeutic characteristics of high energy proton beams. The Fermilab location for a proton therapy facility (PTF) is being chosen for reasons ranging from lower total construction and operating costs and the availability of sophisticated technical support to a location with good access to patients from the Chicago area and from the entire nation. 9 refs., 4 figs., 26 tabs

  17. Proton beam therapy facility

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-09

    It is proposed to build a regional outpatient medical clinic at the Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois, to exploit the unique therapeutic characteristics of high energy proton beams. The Fermilab location for a proton therapy facility (PTF) is being chosen for reasons ranging from lower total construction and operating costs and the availability of sophisticated technical support to a location with good access to patients from the Chicago area and from the entire nation. 9 refs., 4 figs., 26 tabs.

  18. PROTON MICROSCOPY AT FAIR

    International Nuclear Information System (INIS)

    Merrill, F. E.; Mariam, F. G.; Golubev, A. A.; Turtikov, V. I.; Varentsov, D.

    2009-01-01

    Proton radiography was invented in the 1990's at Los Alamos National Laboratory (LANL) as a diagnostic to study dynamic material properties under extreme pressures, strain and strain rate. Since this time hundreds of dynamic proton radiography experiments have been performed at LANL and a facility has been commissioned at the Institute for Theoretical and Experimental Physics (ITEP) in Russia for similar applications in dynamic material studies. Recently an international effort has investigated a new proton radiography capability for the study of dynamic material properties at the Facility for Anti-proton and Ion Research (FAIR) located in Darmstadt, Germany. This new Proton microscope for FAIR(PRIOR) will provide radiographic imaging of dynamic systems with unprecedented spatial, temporal and density resolution, resulting in a window for understanding dynamic material properties at new length scales. It is also proposed to install the PRIOR system at the GSI Helmholtzzentrum fuer Schwerionenforschung before installation at FAIR for dynamic experiments with different drivers including high explosives, pulsed power and lasers. The design of the proton microscope and expected radiographic performance is presented.

  19. Multicavity proton cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    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.

  20. Integrated induction coil and fluxgate magnetometers for EM analysis and monitoring

    Science.gov (United States)

    Hanstein, T.; Strack, K.; Jiang, J.

    2013-12-01

    The concept of a full field array electromagnetic system is an ideal tool to support hydrocarbon and geothermal E & P as well as various engineering monitoring applications. Some of the key questions are defining the reservoir, mapping of the fractures and reservoir depletion monitoring. The reservoirs are all too often relative thin and give an anomalous electromagnetic (EM) response, which is often small in amplitude and challenging for the EM measuring system. A digital fluxgate magnetometer (32-bit) is connected to the KMS magnetotelluric acquisition system with analogue induction coils and electrodes to extend the range of application of a single recording site. Since the noise level is above that of the induction coil for periods shorter than 20 s, the apparent resistivity is biased. For longer periods the apparent resistivity is consistent and eventually better than the induction coil. However, phase and tipper are not biased and agree well with the induction data even for shorter periods. This allows us to develop algorithms that significantly extend the range of application of the fluxgate beyond what was done in the past. The highest frequency of the fluxgate magnetometer is about 180 Hz and the hightest sampling of the FG-board is 4 kHz.The different induction coils and fluxgate magnetometer have intensively been tested in the magnetic chamber and at the field test site near Houston for noise performance by parallel recordings. They show that even in an environment with high cultural noise, the specification can be met. In Northeast China, a 30-day monitoring test with MT was carried out for seismologic applications. Acquisitition schedule included different recordings times and sampling rates. Daily, the data was collected and processed via the internet from either Europe or the US. Even with long recording, we still had to select the time windows for data averaging and coherences are not a good threshhold criteria in this case. During another MT

  1. Proton Radiography to Improve Proton Radiotherapy : Simulation Study at Different Proton Beam Energies

    NARCIS (Netherlands)

    Biegun, Aleksandra; Takatsu, Jun; van Goethem, Marc-Jan; van der Graaf, Emiel; van Beuzekom, Martin; Visser, Jan; Brandenburg, Sijtze

    To improve the quality of cancer treatment with protons, a translation of X-ray Computed Tomography (CT) images into a map of the proton stopping powers needs to be more accurate. Proton stopping powers determined from CT images have systematic uncertainties in the calculated proton range in a

  2. Thermodynamics of a closed-cycle gas flow system for cooling a HTc dc-SQUID magnetometer

    NARCIS (Netherlands)

    van den Bosch, P.J.; van den Bosch, P.J.; ter Brake, Hermanus J.M.; van den Eijkel, G.C.; Boelens, J.P.; Holland, Herman J.; Verberne, J.F.C.; Rogalla, Horst

    1994-01-01

    A multichannel high-Tc dc-SQUID based heart-magnetometer is currently under development in our laboratory. The system is cooled by a cooler that, due to its magnetic interference, has to be separated from the SQUID unit. In the present prototype system a closed-cycle gas flow was chosen as the

  3. MOURA magnetometer for Mars MetNet Precursor Mission. Its potential for an in situ magnetic environment and surface characterization

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Michelena, M.; Sanz, R.; Fernandez, A.B.; Manuel, V. de; Cerdan, M.F.; Apestigue, V.; Arruego, I.; Azcue, J.; Dominguez, J.A.; Gonzalez, M.; Guerrero, H.; Sabau, M.; Kilian, R.; Baeza, O.; Ros, F.; Vazquez, M.; Tordesillas, J.M.; Covisa, P.; Aguado, J.

    2016-07-01

    MOURA magnetometer and gradiometer is part of the scientific instrumentation for Mars MetNet Precursor mission. This work describes the objective of the investigation, summarizes the work done in the design and development of the sensor as well as its calibration, and shows the demonstration campaigns to show the potential of such instrument for planetary landers and rovers. (Author)

  4. Comparison between SuperDARN flow vectors and equivalent ionospheric currents from ground magnetometer arrays

    DEFF Research Database (Denmark)

    Weygand, J. M.; Amm, O.; Angelopoulos, V.

    2012-01-01

    seasons. This comparison is done over a range of spatial separations, magnetic latitudes, magnetic local times, and auroral electrojet activity to investigate under what conditions the vectors are anti-parallel to one another. Our results show that in general the equivalent ionospheric currents are anti...... that may influence the alignment include ionospheric conductivity gradients and quiet time backgrounds. Our results can be used to approximate the macroscopic (similar to 1000 km) ionospheric convection patterns. The SECS maps represent a value-added product from the raw magnetometer database and can...... be used for contextual interpretation; they can help with our understanding of magnetosphere-ionosphere coupling mechanisms using ground arrays and the magnetospheric spacecraft data, and they can be used as input for other techniques....

  5. Triaxial digital fluxgate magnetometer for NASA applications explorer mission: Results of tests of critical elements

    Science.gov (United States)

    Mcleod, M. G.; Means, J. D.

    1977-01-01

    Tests performed to prove the critical elements of the triaxial digital fluxgate magnetometer design were described. A method for improving the linearity of the analog to digital converter portion of the instrument was studied in detail. A sawtooth waveform was added to the signal being measured before the A/D conversion, and averaging the digital readings over one cycle of the sawtooth. It was intended to reduce bit error nonlinearities present in the A/D converter which could be expected to be as much as 16 gamma if not reduced. No such nonlinearities were detected in the output of the instrument which included the feature designed to reduce these nonlinearities. However, a small scale nonlinearity of plus or minus 2 gamma with a 64 gamma repetition rate was observed in the unit tested. A design improvement intended to eliminate this small scale nonlinearity was examined.

  6. Summary of initial results from the GSFC fluxgate magnetometer on Pioneer 11

    Science.gov (United States)

    Acuna, M. H.; Ness, N. F.

    1975-01-01

    The main magnetic field of Jupiter was measured by the Fluxgate Magnetometer on Pioneer 11 and analysis reveals it to be relatively more complex than expected. In a centered spherical harmonic representation with a maximum order of n = 3 (designated GSFC model 04), the dipole term (with opposite polarity to the Earth's) has a moment of 4.28 Gauss x (Jupiter radius cubed), tilted by 9.6 deg towards a system 111 longitude of 232. The quadrupole and octupole moments are significant, 24% and 21% of the dipole moment respectively, and this leads to deviations of the planetary magnetic field from a simple offset tilted dipole for distances smaller than three Jupiter radii. The GSFC model shows a north polar field strength of 14 Gauss and a south polar field strength of 10.4 Gauss. Enhanced absorption effects in the radiation belts may be predicted as a result of field distortion.

  7. Development, construction and analysis of the "Ørsted" fluxgate magnetometer

    DEFF Research Database (Denmark)

    Nielsen, Otto V; Petersen, Jan Raagaard; Primdahl, Fritz

    1995-01-01

    glass ribbons as core materials. It is shown that very simple physical models can be used to explain the fluxgate mode of operation, thereby making it easy to calculate the overall sensor performance from first principles. Special attention is drawn to the core excitation current which is analysed...... in the instrument (±65 536 nT with 0.5 nT resolution). The maximum attainablebandwidth is half the sensor excitation frequency (½ x 15 kHz) but the Ørsted magnetometer bandwidth is limited to 250 Hz. The thermal stability of the sensor has been measured to be better than 1 nT in the temperature range -20 to +60°C....

  8. Infrastructure-Less Indoor Localization Using the Microphone, Magnetometer and Light Sensor of a Smartphone.

    Science.gov (United States)

    Galván-Tejada, Carlos E; García-Vázquez, Juan Pablo; Galván-Tejada, Jorge I; Delgado-Contreras, J Rubén; Brena, Ramon F

    2015-08-18

    In this paper, we present the development of an infrastructure-less indoor location system (ILS), which relies on the use of a microphone, a magnetometer and a light sensor of a smartphone, all three of which are essentially passive sensors, relying on signals available practically in any building in the world, no matter how developed the region is. In our work, we merge the information from those sensors to estimate the user's location in an indoor environment. A multivariate model is applied to find the user's location, and we evaluate the quality of the resulting model in terms of sensitivity and specificity. Our experiments were carried out in an office environment during summer and winter, to take into account changes in light patterns, as well as changes in the Earth's magnetic field irregularities. The experimental results clearly show the benefits of using the information fusion of multiple sensors when contrasted with the use of a single source of information.

  9. Magnetic field `flyby' measurement using a smartphone's magnetometer and accelerometer simultaneously

    Science.gov (United States)

    Monteiro, Martín; Stari, Cecilia; Cabeza, Cecilia; Marti, Arturo C.

    2017-12-01

    The spatial dependence of magnetic fields in simple configurations is a common topic in introductory electromagnetism lessons, both in high school and in university courses. In typical experiments, magnetic fields and distances are obtained taking point-by-point values using a Hall sensor and a ruler, respectively. Here, we show how to take advantage of the smartphone capabilities to get simultaneous measures with the built-in accelerometer and magnetometer and to obtain the spatial dependence of magnetic fields. We consider a simple setup consisting of a smartphone mounted on a track whose direction coincides with the axis of a coil. While the smartphone is moving on the track, both the magnetic field and the distance from the center of the coil (integrated numerically from the acceleration values) are simultaneously obtained. This methodology can easily be extended to more complicated setups.

  10. Investigation of a low-cost magneto-inductive magnetometer for space science applications

    Science.gov (United States)

    Regoli, Leonardo H.; Moldwin, Mark B.; Pellioni, Matthew; Bronner, Bret; Hite, Kelsey; Sheinker, Arie; Ponder, Brandon M.

    2018-03-01

    A new sensor for measuring low-amplitude magnetic fields that is ideal for small spacecraft is presented. The novel measurement principle enables the fabrication of a low-cost sensor with low power consumption and with measuring capabilities that are comparable to recent developments for CubeSat applications. The current magnetometer, a software-modified version of a commercial sensor, is capable of detecting fields with amplitudes as low as 8.7 nT at 40 Hz and 2.7 nT at 1 Hz, with a noise floor of 4 pT/Hz at 1 Hz. The sensor has a linear response to less than 3 % over a range of ±100 000 nT. All of these features make the magneto-inductive principle a promising technology for the development of magnetic sensors for both space-borne and ground-based applications to study geomagnetic activity.

  11. Measurements on very small single crystals of NdFeB using a vibrating reed magnetometer

    International Nuclear Information System (INIS)

    Richter, H.J.; Hempel, K.A.; Verhoef, R.

    1988-01-01

    Nd 2 Fe 14 B single crystals with magnetic moments ranging from 1.6 x 10 -8 Acm 2 to 9.5 x 10 -7 Acm 2 are measured using the ultra high sensitivity vibrating reed magnetometer. The hysteresis loops are compared to those of BaFe 12 O 19 single crystals. It turns out that the magnetization reversal of the Nd 2 Fe 14 B samples is similar to that of BaFe 12 O 19 single crystals if the ferrite samples are considerably bigger in size. This does not hold for bigger Nd 2 Fe 14 B particles where stronger domain wall pinning is observed. For very small grains of Nd 2 Fe 14 B there is still evidence of domain wall processes while for BaFe 12 O 19 grains of the same size true single domain behaviour can be observed

  12. Hypervelocity dust particle impacts observed by the Giotto magnetometer and plasma experiments

    International Nuclear Information System (INIS)

    Neubauer, F.M.; Glassmeier, K.H.; Goldstein, R.; Acuna, M.H.; Musmann, G.; Coates, A.J.

    1990-01-01

    The authors report thirteen very short events in the magnetic field of the inner magnetic pile-up region of comet Halley observed by the Giotto magnetometer experiment together with simultaneous plasma data obtained by the Johnstone plasma analyzer and the ion mass spectrometer experiments. The events are due to dust impacts in the milligram range on the spacecraft at the relative velocity between the cometary dust and the spacecraft of 68 km/sec. They are generally consistent with dust impact events derived from spacecraft attitude perturbations by the Giotto camera [Curdt and Keller, private communication]. Their characteristic shape generally involves a sudden decrease in magnetic field magnitude, a subsequent overshoot beyond initial field values and an asymptotic approach to the initial field somewhat reminiscent of the magnetic field signature after the AMPTE releases in the solar wind. These observations give a new way of analyzing ultra-fast dust particles incident on a spacecraft

  13. Hypervelocity dust particle impacts observed by the Giotto magnetometer and plasma experiments

    Science.gov (United States)

    Neubauer, F. M.; Glassmeier, K.-H.; Coates, A. J.; Goldstein, R.; Acuna, M. H.

    1990-01-01

    This paper describes 13 very short events in the magnetic field of the inner magnetic pile-up region of Comet Halley observed by the Giotto magnetometer experiment together with simultaneous plasma data obtained by the Johnstone plasma analyzer and the ion mass spectrometer experiments. The events are due to dust impacts in the milligram range on the spacecraft at the relative velocity between the cometary dust and the spacecraft of 68 km/sec. They are generally consistent with dust impact events derived from spacecraft attitude perturbations by the Giotto camera. Their characteristic shape generally involves a sudden decrease in magnetic-field magnitude, a subsequent overshoot beyond initial field values, and an asymptotic approach to the initial field (somewhat reminiscent of the magnetic-field signature after the AMPTE releases in the solar wind). These observations give a new way of analyzing ultra-fast dust particles incident on a spacecraft.

  14. A 3-Axis Miniature Magnetic Sensor Based on a Planar Fluxgate Magnetometer with an Orthogonal Fluxguide

    Directory of Open Access Journals (Sweden)

    Chih-Cheng Lu

    2015-06-01

    Full Text Available A new class of tri-axial miniature magnetometer consisting of a planar fluxgate structure with an orthogonal ferromagnetic fluxguide centrally situated over the magnetic cores is presented. The magnetic sensor possesses a cruciform ferromagnetic core placed diagonally upon the square excitation coil under which two pairs of pick-up coils for in-plane field detection are allocated. Effective principles and analysis of the magnetometer for 3-D field vectors are described and verified by numerically electromagnetic simulation for the excitation and magnetization of the ferromagnetic cores. The sensor is operated by applying the second-harmonic detection technique that can verify V-B relationship and device responsivity. Experimental characterization of the miniature fluxgate device demonstrates satisfactory spatial magnetic field detection results in terms of responsivity and noise spectrum. As a result, at an excitation frequency of 50 kHz, a maximum in-plane responsivity of 122.4 V/T appears and a maximum out-of-plane responsivity of 11.6 V/T is obtained as well. The minimum field noise spectra are found to be 0.11 nT/√Hz and 6.29 nT/√Hz, respectively, in X- and Z-axis at 1 Hz under the same excitation frequency. Compared with the previous tri-axis fluxgate devices, this planar magnetic sensor with an orthogonal fluxguide provides beneficial enhancement in both sensory functionality and manufacturing simplicity. More importantly, this novel device concept is considered highly suitable for the extension to a silicon sensor made by the current CMOS-MEMS technologies, thus emphasizing its emerging applications of field detection in portable industrial electronics.

  15. Real-time Geomagnetic Data from a Raspberry Pi Magnetometer Network in the United Kingdom

    Science.gov (United States)

    Case, N.; Beggan, C.; Marple, S. R.

    2017-12-01

    In 2014, BGS and the University of Lancaster won an STFC Public Engagement grant to build and deploy 10 Raspberry Pi magnetometers to secondary schools across the UK to enable citizen science. The system uses a Raspberry Pi computer as a logging and data transfer device, connected to a set of three orthogonal miniature fluxgate magnetometers. The system has a nominal sensitivity of around 1 nanoTesla (nT), in each component direction (North, East and Down). This is around twenty times less sensitive than a current scientific-level instrument, but given its relatively low-cost, at about £250 ($325) per unit, this is an excellent price-to-performance ratio given we could not improve the sensitivity unless we spent a lot more money. The magnetic data are sampled at a 5 second cadence and sent to the AuroraWatch website at Lancaster University every 2 minutes. The data are freely available to view and download. The primary aim of the project is to encourage students from 14-18 years old to look at how sensors can be used to collect geophysical data and integrate it together to give a wider understanding of physical phenomena. A second aim is to provide useful data on the spatial variation of the magnetic field for analysis of geomagnetic storms, alongside data from the BGS observatory and University of Lancaster's SAMNET variometer network. We show results from the build, testing and running of the sensors including some recent storms and we reflect on our experiences in engaging schools and the general public with information about the magnetic field. The information to build the system and logging and analysis software for the Raspberry Pi is all freely available, allowing those interested to participate in the project as citizen scientists.

  16. High-Sensitivity Low-Noise Miniature Fluxgate Magnetometers Using a Flip Chip Conceptual Design

    Directory of Open Access Journals (Sweden)

    Chih-Cheng Lu

    2014-07-01

    Full Text Available This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB substrate and electrically connected to each other similar to the current “flip chip” concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. Principles and analysis of the fluxgate sensor are introduced first, and followed by FEA electromagnetic modeling and simulation for the proposed sensor. Comprehensive characteristic experiments of the miniature fluxgate device exhibit favorable results in terms of sensitivity (or “responsivity” for magnetometers and field noise spectrum. The sensor is driven and characterized by employing the improved second-harmonic detection technique that enables linear V-B correlation and responsivity verification. In addition, the double magnitude of responsivity measured under very low frequency (1 Hz magnetic fields is experimentally demonstrated. As a result, the maximum responsivity of 593 V/T occurs at 50 kHz of excitation frequency with the second harmonic wave of excitation; however, the minimum magnetic field noise is found to be 0.05 nT/Hz1/2 at 1 Hz under the same excitation. In comparison with other miniature planar fluxgates published to date, the fluxgate magnetic sensor with flip chip configuration offers advances in both device functionality and fabrication simplicity. More importantly, the novel design can be further extended to a silicon-based micro-fluxgate chip manufactured by emerging CMOS-MEMS technologies, thus enriching its potential range of applications in modern engineering and the consumer electronics market.

  17. A 3-Axis Miniature Magnetic Sensor Based on a Planar Fluxgate Magnetometer with an Orthogonal Fluxguide.

    Science.gov (United States)

    Lu, Chih-Cheng; Huang, Jeff

    2015-06-19

    A new class of tri-axial miniature magnetometer consisting of a planar fluxgate structure with an orthogonal ferromagnetic fluxguide centrally situated over the magnetic cores is presented. The magnetic sensor possesses a cruciform ferromagnetic core placed diagonally upon the square excitation coil under which two pairs of pick-up coils for in-plane field detection are allocated. Effective principles and analysis of the magnetometer for 3-D field vectors are described and verified by numerically electromagnetic simulation for the excitation and magnetization of the ferromagnetic cores. The sensor is operated by applying the second-harmonic detection technique that can verify V-B relationship and device responsivity. Experimental characterization of the miniature fluxgate device demonstrates satisfactory spatial magnetic field detection results in terms of responsivity and noise spectrum. As a result, at an excitation frequency of 50 kHz, a maximum in-plane responsivity of 122.4 V/T appears and a maximum out-of-plane responsivity of 11.6 V/T is obtained as well. The minimum field noise spectra are found to be 0.11 nT/√Hz and 6.29 nT/√Hz, respectively, in X- and Z-axis at 1 Hz under the same excitation frequency. Compared with the previous tri-axis fluxgate devices, this planar magnetic sensor with an orthogonal fluxguide provides beneficial enhancement in both sensory functionality and manufacturing simplicity. More importantly, this novel device concept is considered highly suitable for the extension to a silicon sensor made by the current CMOS-MEMS technologies, thus emphasizing its emerging applications of field detection in portable industrial electronics.

  18. High-Sensitivity Low-Noise Miniature Fluxgate Magnetometers Using a Flip Chip Conceptual Design

    Science.gov (United States)

    Lu, Chih-Cheng; Huang, Jeff; Chiu, Po-Kai; Chiu, Shih-Liang; Jeng, Jen-Tzong

    2014-01-01

    This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB) substrate and electrically connected to each other similar to the current “flip chip” concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. Principles and analysis of the fluxgate sensor are introduced first, and followed by FEA electromagnetic modeling and simulation for the proposed sensor. Comprehensive characteristic experiments of the miniature fluxgate device exhibit favorable results in terms of sensitivity (or “responsivity” for magnetometers) and field noise spectrum. The sensor is driven and characterized by employing the improved second-harmonic detection technique that enables linear V-B correlation and responsivity verification. In addition, the double magnitude of responsivity measured under very low frequency (1 Hz) magnetic fields is experimentally demonstrated. As a result, the maximum responsivity of 593 V/T occurs at 50 kHz of excitation frequency with the second harmonic wave of excitation; however, the minimum magnetic field noise is found to be 0.05 nT/Hz1/2 at 1 Hz under the same excitation. In comparison with other miniature planar fluxgates published to date, the fluxgate magnetic sensor with flip chip configuration offers advances in both device functionality and fabrication simplicity. More importantly, the novel design can be further extended to a silicon-based micro-fluxgate chip manufactured by emerging CMOS-MEMS technologies, thus enriching its potential range of applications in modern engineering and the consumer electronics market. PMID:25196107

  19. Sensitivity of proposed search for axion-induced magnetic field using optically pumped magnetometers

    Science.gov (United States)

    Chu, P.-H.; Duffy, L. D.; Kim, Y. J.; Savukov, I. M.

    2018-04-01

    We investigate the sensitivity of a search for the oscillating current induced by axion dark matter in an external magnetic field using optically pumped magnetometers. This experiment is based upon the LC circuit (circuit with inductor and capacitor) axion detection concept of Sikivie et al. [Phys. Rev. Lett. 112, 131301 (2014), 10.1103/PhysRevLett.112.131301]. The modification of Maxwell's equations caused by the axion-photon coupling results in a minute magnetic field oscillating at a frequency equal to the axion mass, in the presence of an external magnetic field. The axion-induced magnetic field could be searched for using a LC circuit amplifier with an optically pumped magnetometer, the most sensitive cryogen-free magnetic-field sensor, in a room-temperature experiment, avoiding the need for a complicated and expensive cryogenic system. We discuss how an existing magnetic resonance imaging experiment can be modified to search for axions in a previously unexplored part of the parameter space. Our existing detection setup, optimized for magnetic resonance imagining, is already sensitive to an axion-photon coupling of 10-7 GeV-1 for an axion mass near 3 ×10-10 eV , which is already limited by astrophysical processes and solar axion searches. We show that realistic modifications, and optimization of the experiment for axion detection, can probe the axion-photon coupling up to 4 orders of magnitude beyond the current best limit, for axion masses between 10-11 and 10-7 eV .

  20. Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

    Science.gov (United States)

    Bechstein, S.; Petsche, F.; Scheiner, M.; Drung, D.; Thiel, F.; Schnabel, A.; Schurig, Th

    2006-06-01

    Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-Tc dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm × 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm × 4 cm × 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

  1. High-sensitivity low-noise miniature fluxgate magnetometers using a flip chip conceptual design.

    Science.gov (United States)

    Lu, Chih-Cheng; Huang, Jeff; Chiu, Po-Kai; Chiu, Shih-Liang; Jeng, Jen-Tzong

    2014-07-30

    This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB) substrate and electrically connected to each other similar to the current "flip chip" concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. Principles and analysis of the fluxgate sensor are introduced first, and followed by FEA electromagnetic modeling and simulation for the proposed sensor. Comprehensive characteristic experiments of the miniature fluxgate device exhibit favorable results in terms of sensitivity (or "responsivity" for magnetometers) and field noise spectrum. The sensor is driven and characterized by employing the improved second-harmonic detection technique that enables linear V-B correlation and responsivity verification. In addition, the double magnitude of responsivity measured under very low frequency (1 Hz) magnetic fields is experimentally demonstrated. As a result, the maximum responsivity of 593 V/T occurs at 50 kHz of excitation frequency with the second harmonic wave of excitation; however, the minimum magnetic field noise is found to be 0.05 nT/Hz(1/2) at 1 Hz under the same excitation. In comparison with other miniature planar fluxgates published to date, the fluxgate magnetic sensor with flip chip configuration offers advances in both device functionality and fabrication simplicity. More importantly, the novel design can be further extended to a silicon-based micro-fluxgate chip manufactured by emerging CMOS-MEMS technologies, thus enriching its potential range of applications in modern engineering and the consumer electronics market.

  2. A large-scale view of Space Technology 5 magnetometer response to solar wind drivers.

    Science.gov (United States)

    Knipp, D J; Kilcommons, L M; Gjerloev, J; Redmon, R J; Slavin, J; Le, G

    2015-04-01

    In this data report we discuss reprocessing of the Space Technology 5 (ST5) magnetometer database for inclusion in NASA's Coordinated Data Analysis Web (CDAWeb) virtual observatory. The mission consisted of three spacecraft flying in elliptical orbits, from 27 March to 27 June 2006. Reprocessing includes (1) transforming the data into the Modified Apex Coordinate System for projection to a common reference altitude of 110 km, (2) correcting gain jumps, and (3) validating the results. We display the averaged magnetic perturbations as a keogram, which allows direct comparison of the full-mission data with the solar wind values and geomagnetic indices. With the data referenced to a common altitude, we find the following: (1) Magnetic perturbations that track the passage of corotating interaction regions and high-speed solar wind; (2) unexpectedly strong dayside perturbations during a solstice magnetospheric sawtooth oscillation interval characterized by a radial interplanetary magnetic field (IMF) component that may have enhanced the accompanying modest southward IMF; and (3) intervals of reduced magnetic perturbations or "calms," associated with periods of slow solar wind, interspersed among variable-length episodic enhancements. These calms are most evident when the IMF is northward or projects with a northward component onto the geomagnetic dipole. The reprocessed ST5 data are in very good agreement with magnetic perturbations from the Defense Meteorological Satellite Program (DMSP) spacecraft, which we also map to 110 km. We briefly discuss the methods used to remap the ST5 data and the means of validating the results against DMSP. Our methods form the basis for future intermission comparisons of space-based magnetometer data.

  3. Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

    International Nuclear Information System (INIS)

    Bechstein, S; Petsche, F; Scheiner, M; Drung, D; Thiel, F; Schnabel, A; Schurig, Th

    2006-01-01

    Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/√Hz was specially designed for a 304-channel low-T c dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm x 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm x 4 cm x 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented

  4. Digitally controlled high-performance dc SQUID readout electronics for a 304-channel vector magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Bechstein, S [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Petsche, F [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Scheiner, M [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Drung, D [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Thiel, F [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Schnabel, A [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Schurig, Th [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)

    2006-06-01

    Recently, we have developed a family of dc superconducting quantum interference device (SQUID) readout electronics for several applications. These electronics comprise a low-noise preamplifier followed by an integrator, and an analog SQUID bias circuit. A highly-compact low-power version with a flux-locked loop bandwidth of 0.3 MHz and a white noise level of 1 nV/{radical}Hz was specially designed for a 304-channel low-T{sub c} dc SQUID vector magnetometer, intended to operate in the new Berlin Magnetically Shielded Room (BMSR-2). In order to minimize the space needed to mount the electronics on top of the dewar and to minimize the power consumption, we have integrated four electronics channels on one 3 cm x 10 cm sized board. Furthermore we embedded the analog components of these four channels into a digitally controlled system including an in-system programmable microcontroller. Four of these integrated boards were combined to one module with a size of 4 cm x 4 cm x 16 cm. 19 of these modules were implemented, resulting in a total power consumption of about 61 W. To initialize the 304 channels and to service the system we have developed software tools running on a laptop computer. By means of these software tools the microcontrollers are fed with all required data such as the working points, the characteristic parameters of the sensors (noise, voltage swing), or the sensor position inside of the vector magnetometer system. In this paper, the developed electronics including the software tools are described, and first results are presented.

  5. Magnetometer-inferred, Equatorial, Daytime Vertical ExB Drift Velocities Observed in the African Longitude Sector

    Science.gov (United States)

    Anderson, D. N.; Yizengaw, E.

    2011-12-01

    A recent paper has investigated the sharp longitude gradients in the dayside ExB drift velocities associated with the 4-cell, non-migrating structures thought to be connected with the eastward propagating, diurnal, non-migrating (DE3) tides. Observations of vertical ExB drift velocities obtained from the Ion Velocity Meter (IVM) on the Communication/Navigation Outage Forecast System (C/NOFS) satellite were obtained in the Western Pacific, Eastern Pacific, Peruvian and Atlantic sectors for a few days during the months of October, March and December, 2009. Respective ExB drift velocity gradients at the cell boundaries for these 4 longitude sectors were a.) -1.3m/sec/degree, b.) 3m/sec/degree, c.) -4m/sec/degree and d.) 1m/sec/degree and were observed on a day-to-day basis. In this talk, we estimate the longitude gradients in the dayside, vertical ExB drift velocities from magnetometer H-component observations in the African sector. We briefly describe the technique for obtaining realistic ExB drift velocities associated with the difference in the H-component values between a magnetometer on the magnetic equator and one off the magnetic equator at 6 to 9 degrees dip latitude (delta H). We present magnetometer-inferred, dayside ExB drift velocities obtained from the AMBER (African Meridian B-field Education and Research) magnetometer chain in the East Africa (Ethiopian) longitude sector and the West African (Nigerian) longitude sector. We compare the longitude gradients in ExB drift velocities in the African sector with the C/NOFS- observed longitude gradients mentioned above. We also discuss the advantages of using ground-based magnetometer observations to infer ExB drift velocities compared with the C/NOFS satellite observations.

  6. Proton therapy in Australia

    International Nuclear Information System (INIS)

    Jackson, M.

    2000-01-01

    Full text: Proton therapy has been in use since 1954 and over 25,000 patients have been treated worldwide. Until recently most patients were treated at physics research facilities but with the development of more compact and reliable accelerators it is now possible to realistically plan for proton therapy in an Australian hospital. The Australian National Proton Project has been formed to look at the feasibility of a facility which would be primarily for patient treatment but would also be suitable for research and commercial applications. A detailed report will be produced by the end of the year. The initial clinical experience was mainly with small tumours and other lesions close to critical organs. Large numbers of eye tumours have also been treated. Protons have a well-defined role in these situations and are now being used in the treatment of more common cancers. With the development of hospital-based facilities, over 2,500 patients with prostate cancer have been treated using a simple technique which gives results at least as good as radical surgery, external beam radiotherapy or brachytherapy. Importantly, the incidence of severe complications is very low. There are encouraging results in many disease sites including lung, liver, soft tissue sarcomas and oesophagus. As proton therapy becomes more widely available, randomised trials comparing it with conventional radiotherapy or Intensity Modulated Radiation Therapy (IMRT) will be possible. In most situations the use of protons will enable a higher dose to be given safely but in situations where local control rates are already satisfactory, protons are expected to produce less complications than conventional treatment. The initial costs of a proton facility are high but the recurrent costs are similar to other forms of high technology radiotherapy. . Simple treatment techniques with only a few fields are usually possible and proton therapy avoids the high integral doses associated with IMRT. This reduction in

  7. Proton dynamics in cancer.

    Science.gov (United States)

    Huber, Veronica; De Milito, Angelo; Harguindey, Salvador; Reshkin, Stephan J; Wahl, Miriam L; Rauch, Cyril; Chiesi, Antonio; Pouysségur, Jacques; Gatenby, Robert A; Rivoltini, Licia; Fais, Stefano

    2010-06-15

    Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth.Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC) in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

  8. Proton dynamics in cancer

    Directory of Open Access Journals (Sweden)

    Pouysségur Jacques

    2010-06-01

    Full Text Available Abstract Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth. Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

  9. Polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

  10. Journal of Proton Therapy

    Directory of Open Access Journals (Sweden)

    Editorial Office

    2015-01-01

    Full Text Available Journal of Proton Therapy (JPT is an international open access, peer-reviewed journal, which publishes original research, technical reports, reviews, case reports, editorials, and other materials on proton therapy with focus on radiation oncology, medical physics, medical dosimetry, and radiation therapy.No article processing/submission feeNo publication feePeer-review completion within 3-6 weeksImmediate publication after the completion of final author proofreadDOI assignment for each published articleFree access to published articles for all readers without any access barriers or subscriptionThe views and opinions expressed in articles are those of the author/s and do not necessarily reflect the policies of the Journal of Proton Therapy.Authors are encouraged to submit articles for publication in the inaugural issue of the Journal of Proton Therapy by online or email to editor@protonjournal.comOfficial Website of Journal of Proton Therapy: http://www.protonjournal.org/

  11. Medical Proton Accelerator Project

    International Nuclear Information System (INIS)

    Comsan, M.N.H.

    2008-01-01

    A project for a medical proton accelerator for cancer treatment is outlined. The project is motivated by the need for a precise modality for cancer curing especially in children. Proton therapy is known by its superior radiation and biological effectiveness as compared to photon or electron therapy. With 26 proton and 3 heavy-ion therapy complexes operating worldwide only one (p) exists in South Africa, and none in south Asia and the Middle East. The accelerator of choice should provide protons with energy 75 MeV for eye treatment and 250 MeV for body treatment. Four treatment rooms are suggested: two with isocentric gantries, one with fixed beams and one for development. Passive scanning is recommended. The project can serve Middle East and North Africa with ∼ 400 million populations. The annual capacity of the project is estimated as 1,100 to be compared with expected radiation cases eligible for proton cancer treatment of not less than 200,000

  12. Proton relativistic model; Modelo relativistico do proton

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Wilson Roberto Barbosa de

    1996-12-31

    In this dissertation, we present a model for the nucleon, which is composed by three relativistic quarks interacting through a contract force. The nucleon wave-function was obtained from the Faddeev equation in the null-plane. The covariance of the model under kinematical null-plane boots is discussed. The electric proton form-factor, calculated from the Faddeev wave-function, was in agreement with the data for low-momentum transfers and described qualitatively the asymptotic region for momentum transfers around 2 GeV. (author) 42 refs., 22 figs., 1 tab.

  13. Synchrotron radiation from protons

    International Nuclear Information System (INIS)

    Dutt, S.K.

    1992-12-01

    Synchrotron radiation from protons, though described by the same equations as the radiation from electrons, exhibits a number of interesting features on account of the parameters reached in praxis. In this presentation, we shall point out some of the features relating to (i) normal synchrotron radiation from dipoles in proton machines such as the High Energy Booster and the Superconducting Super Collider; (ii) synchrotron radiation from short dipoles, and its application to light monitors for proton machines, and (iii) synchrotron radiation from undulators in the limit when, the deflection parameter is much smaller than unity. The material for this presentation is taken largely from the work of Hofmann, Coisson, Bossart, and their collaborators, and from a paper by Kim. We shall emphasize the qualitative aspects of synchrotron radiation in the cases mentioned above, making, when possible, simple arguments for estimating the spectral and angular properties of the radiation. Detailed analyses can be found in the literature

  14. Polarized proton colliders

    International Nuclear Information System (INIS)

    Roser, T.

    1995-01-01

    High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes. This will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production. Proposals for polarized proton acceleration for several high energy colliders have been developed. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. This allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 x 10 32 cm -2 s -1

  15. Current-current interaction picture for proton-proton scattering

    International Nuclear Information System (INIS)

    Clarke, D.J.; Lo, S.Y.

    1979-01-01

    The authors propose that color current - color current interaction is reponsible for small angle elastic proton proton scattering at asymptotic energy. Excellent fits are obtained for all data above 12 GeV/c which covers twelve orders of magnitude

  16. Protons and how they are transported by proton pumps

    DEFF Research Database (Denmark)

    Buch-Pedersen, Morten Jeppe; Pedersen, Bjørn Panyella; Veierskov, Bjarke

    2008-01-01

    The very high mobility of protons in aqueous solutions demands special features of membrane proton transporters to sustain efficient yet regulated proton transport across biological membranes. By the use of the chemical energy of ATP, plasma-membrane-embedded ATPases extrude protons from cells...... of plants and fungi to generate electrochemical proton gradients. The recently published crystal structure of a plasma membrane H(+)-ATPase contributes to our knowledge about the mechanism of these essential enzymes. Taking the biochemical and structural data together, we are now able to describe the basic...... molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological...

  17. The polarization and the fundamental sensitivity of 39K (133Cs)-85Rb-4He hybrid optical pumping spin exchange relaxation free atomic magnetometers.

    Science.gov (United States)

    Liu, Jian-Hua; Jing, Dong-Yang; Wang, Liang-Liang; Li, Yang; Quan, Wei; Fang, Jian-Cheng; Liu, Wu-Ming

    2017-07-28

    The hybrid optical pumping spin exchange relaxation free (SERF) atomic magnetometers can realize ultrahigh sensitivity measurement of magnetic field and inertia. We have studied the 85 Rb polarization of two types of hybrid optical pumping SERF magnetometers based on 39 K- 85 Rb- 4 He and 133 Cs- 85 Rb- 4 He respectively. Then we found that 85 Rb polarization varies with the number density of buffer gas 4 He and quench gas N 2 , pumping rate of pump beam and cell temperature respectively, which will provide an experimental guide for the design of the magnetometer. We obtain a general formula on the fundamental sensitivity of the hybrid optical pumping SERF magnetometer due to shot-noise. The formula describes that the fundamental sensitivity of the magnetometer varies with the number density of buffer gas and quench gas, the pumping rate of pump beam, external magnetic field, cell effective radius, measurement volume, cell temperature and measurement time. We obtain a highest fundamental sensitivity of 1.5073 aT/Hz 1/2 (1 aT = 10 -18 T) with 39 K- 85 Rb- 4 He magnetometer between above two types of magnetometers when 85 Rb polarization is 0.1116. We estimate the fundamental sensitivity limit of the hybrid optical pumping SERF magnetometer to be superior to 1.8359 × 10 -2 aT/Hz 1/2 , which is higher than the shot-noise-limited sensitivity of 1 aT/Hz 1/2 of K SERF atomic magnetometer.

  18. Proton tunneling in solids

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, J.

    1998-10-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  19. Proton irradiation and endometriosis

    International Nuclear Information System (INIS)

    Wood, D.H.; Yochmowitz, M.G.; Salmon, Y.L.; Eason, R.L.; Boster, R.A.

    1983-01-01

    It was found that female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was determined to be 7 years after the proton exposure. The doses and energies of the radiation received by the experimental animals were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event. It is concluded that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crew members. 15 references

  20. Diagnosis by proton bombardment

    International Nuclear Information System (INIS)

    Steward, V.W.; Koehler, A.M.

    1976-01-01

    Beams of monoenergetic protons or other charged ions are passed through the living human body to detect abnormalities and obstructions in body tissue, which abnormalities and obstructions are visualized as density variations in the particle image emerging from the body part under investigation. The particles used are preferably protons having an energy of 100 to 300 MeV, more especially 200 to 300 MeV. The method is of use in detecting inter alia tumors, blood clots, infarcts, soft tissue lesions and multiple sclerosis in patients without exposure to high radiation dosages. 6 claims, 2 drawing figures

  1. Do protons decay

    International Nuclear Information System (INIS)

    Litchfield, P.J.

    1984-09-01

    The experimental status of proton decay is reviewed after the Leipzig International conference, July 1984. A brief comparative description of the currently active experiments is given. From the overall samples of contained events it can be concluded that the experiments are working well and broadly agree with each other. The candidates for proton decay from each experiment are examined. Although several experiments report candidates at a higher rate than expected from background calculations, the validity of these calculations is still open to doubt. (author)

  2. Proton tunneling in solids

    International Nuclear Information System (INIS)

    Kondo, J.

    1998-01-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  3. Proton Beam Writing

    International Nuclear Information System (INIS)

    Rajta, I.; Szilasi, S.Z.; Csige, I.; Baradacs, E.

    2005-01-01

    Complete text of publication follows. Refractive index depth profile in PMMA due to proton irradiation Proton Beam Writing has been successfully used to create buried channel waveguides in PMMA, which suggested that proton irradiation increases the refractive index. To investigate this effect, PMMA samples were irradiated by 1.7-2.1 MeV proton beam. Spectroscopic Ellipsometry has been used to investigate the depth profile of the refractive index. An increase of the refractive index was observed in the order of 0.01, which is approximately one order of magnitude higher than the detection limit. The highest increase of the refractive index occurs at the end of range, i.e. we found a good correlation with the Bragg curve of the energy loss. Hardness changes in PMMA due to proton beam micromachining As protons penetrate a target material and lose their energy according to the Bragg curve, the energy loss is different at different depths. This causes depth-dependent changes of some physical properties in the target material (e.g. refractive index, hardness). In order to characterize the changes of hardness and other mechanical properties as a function of beam penetration depth, systematic investigations have been performed on PMMA, the most common resist material used in proton beam micromachining. Silicon check valve made by proton beam micromachining The possible application of Proton Beam Micromachining (PBM) has been demonstrated by a few authors for creating 3D Si microstructures. In this work we present alternative methods for the formation of a simple a non-return valve for microfluidic applications. Two different approaches have been applied, in both cases we exploited characteristic features of the PBM technique and the selective formation and dissolution of porous Si over the implantation damaged areas. In the first case we implanted 10 μm thick cantilever-type membrane of the valve normally to the crystal surface and at 30-60 degrees to the sidewalls of the

  4. Proton-proton bremsstrahlung in a relativistic covariant model

    NARCIS (Netherlands)

    Martinus, Gerard Henk

    1998-01-01

    Proton-proton bremsstrahlung is one of the simplest processes involving the half off-shell NN interaction. Since protons are equally-charged particles with the same mass, electric-dipole radiation is suppressed and higher-order effects play an important role. Thus it is possible to get information

  5. Predictions of diffractive cross sections in proton-proton collisions

    Energy Technology Data Exchange (ETDEWEB)

    Goulianos, Konstantin [Rockefeller University, 1230 York Avenue, New York, NY 10065 (United States)

    2013-04-15

    We review our pre-LHC predictions of the total, elastic, total-inelastic, and diffractive components of proton-proton cross sections at high energies, expressed in the form of unitarized expressions based on a special parton-model approach to diffraction employing inclusive proton parton distribution functions and QCD color factors and compare with recent LHC results.

  6. Progresses in proton radioactivity studies

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, L. S., E-mail: flidia@ist.utl.pt [Center of Physics and Engineering of Advanced Materials, CeFEMA and Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Maglione, E. [Dipartimento di Fisica e Astronomia “G. Galilei”, Via Marzolo 8, I-35131 Padova, Italy and Istituto Nazionale di Fisica Nucleare, Padova (Italy)

    2016-07-07

    In the present talk, we will discuss recent progresses in the theoretical study of proton radioactivity and their impact on the present understanding of nuclear structure at the extremes of proton stability.

  7. Proton Radiography (pRad)

    Data.gov (United States)

    Federal Laboratory Consortium — The proton radiography project has used 800 MeV protons provided by the LANSCE accelerator facility at LANL, to diagnose more than 300 dynamic experiments in support...

  8. Energetic protons associated with a forward-reverse interplanetary shock pair at 1 A. U

    Energy Technology Data Exchange (ETDEWEB)

    Balogh, A [Imperial Coll. of Science and Technology, London (UK)

    1977-10-01

    A forward-reverse interplanetary shock was observed on 25 March 1969 by the magnetometer and plasma detector on the HEOS-1 satellite. This relatively rare event was described by Chao et al (1972) who concluded that the shock pair was formed at a distance 0.10 to 0.13 AU upstream of the Earth as a result of the interaction between a fast and a slow solar wind streams. Simultaneous observations of 1 MeV solar proton fluxes were also performed on HEOS-1. A characteristic intensity peak was observed as the forward shock passed by the spacecraft. The evolution of the proton intensity, together with a detailed analysis of anisotropies and pitch angle distributions show a complex dynamic picture of the effect of the forward shock on the ambient proton population. Significant changes in particle fluxes are seen to be correlated with fluctuations in the magnetic field. It is suggested that simple geometrical models of shock-assisted acceleration should be expanded to include the effect of magnetic fluctuations on particle fluxes. The interaction region limited by the forward and reverse shocks contained a large variety of magnetic fluctuations. Following the tangential discontinuity separating the fast solar wind stream from the preceding slow stream, a sunward flow was observed in the proton data, followed by a small but significant drop in intensity prior to the reverse shock.

  9. Violent collisions of spinning protons

    Energy Technology Data Exchange (ETDEWEB)

    Krisch, A.D. [Michigan Univ., Spin Physics Center, Ann Arbor, MI (United States)

    2005-07-01

    The author draws the history of polarized proton beams that has relied on experiments that took place in different accelerators like ZGS (zero gradient synchrotron, Argonne), AGS (Brookhaven) and Fermilab from 1973 till today. The first studies of the behavior and spin-manipulation of polarized protons helped in developing polarized beams around the world: Brookhaven now has 200 GeV polarized protons in the RHIC collider, perhaps someday the 7 TeV LHC at CERN might have polarized protons.

  10. Neutron-proton scattering

    International Nuclear Information System (INIS)

    Doll, P.

    1990-02-01

    Neutron-proton scattering as fundamental interaction process below and above hundred MeV is discussed. Quark model inspired interactions and phenomenological potential models are described. The seminar also indicates the experimental improvements for achieving new precise scattering data. Concluding remarks indicate the relevance of nucleon-nucleon scattering results to finite nuclei. (orig.) [de

  11. Proton Pulse Radiolysis

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, H C; Nilsson, G; Reitberger, T; Thuomas, K A

    1973-03-15

    A 5 MeV proton accelerator (Van de Graaff) has been used for pulse radiolysis of a number of organic gases and the transient spectra obtained from the alkanes methane, ethane, propane, n-butane and neopentane have tentatively been assigned to alkyl radicals. Some methodological aspects of this new technique are discussed

  12. The Melbourne proton microprobe

    International Nuclear Information System (INIS)

    Legge, G.J.F.; McKenzie, C.D.; Mazzolini, A.P.

    1979-01-01

    A scanning proton microprobe is described which operates in ultra-high vacuum with a resolution of ten microns. The operating principles and main features of the design are discussed and the ability of such an instrument to detect trace elements down to a few ppm by mass is illustrated

  13. Proton microanalysis in plants

    International Nuclear Information System (INIS)

    Garrec, J.P.

    Micro-analyses by nuclear reactions and atomic excitation are used to determine the distribution of fluorine and calcium in the needles of Abies Alba. Fluorine is detected by the nuclear reaction 19 F(p,α) 16 O at the 1.35 MeV resonance. Calcium is measured by its characteristic X-rays due to proton excitation [fr

  14. Proton transfer events in GFP

    NARCIS (Netherlands)

    Di Donato, M.; van Wilderen, L.J.G.W.; van Stokkum, I.H.M.; Cohen Stuart, T.A.; Kennis, J.T.M.; Hellingwerf, K.J.; van Grondelle, R.; Groot, M.L.

    2011-01-01

    Proton transfer is one of the most important elementary processes in biology. Green fluorescent protein (GFP) serves as an important model system to elucidate the mechanistic details of this reaction, because in GFP proton transfer can be induced by light absorption. Illumination initiates proton

  15. Electrodynamics of an omega-band as deduced from optical and magnetometer data

    Directory of Open Access Journals (Sweden)

    H. Vanhamäki

    2009-09-01

    Full Text Available We investigate an omega-band event that took place above northern Scandinavia around 02:00–02:30 UT on 9 March 1999. In our analysis we use ground based magnetometer, optical and riometer measurements together with satellite based optical images. The optical and riometer data are used to estimate the ionospheric Hall and Pedersen conductances, while ionospheric equivalent currents are obtained from the magnetometer measurements. These data sets are used as input in a local KRM calculation, which gives the ionospheric potential electric field as output, thus giving us a complete picture of the ionospheric electrodynamic state during the omega-band event. The overall structure of the electric field and field-aligned current (FAC provided by the local KRM method are in good agreement with previous studies. Also the E×B drift velocity calculated from the local KRM solution is in good qualitative agreement with the plasma velocity measured by the Finnish CUTLASS radar, giving further support for the new local KRM method. The high-resolution conductance estimates allow us to discern the detailed structure of the omega-band current system. The highest Hall and Pedersen conductances, ~50 and ~25 S, respectively, are found at the edges of the bright auroral tongue. Inside the tongue, conductances are somewhat smaller, but still significantly higher than typical background values. The electric field shows a converging pattern around the tongues, and the field strength drops from ~40 mV/m found at optically dark regions to ~10 mV/m inside the areas of enhanced conductivity. Downward FAC flow in the dark regions, while upward currents flow inside the auroral tongue. Additionally, sharp conductance gradients at the edge of an auroral tongue are associated with narrow strips of intense FACs, so that a strip of downward current flows at the eastern (leading edge and a similar strip of upward current is present at the western (trailing edge. The Joule

  16. Low-frequency noise in high-(Tc) superconductor Josephson junctions, SQUIDs, and magnetometers

    Science.gov (United States)

    Miklich, A. H.

    1994-05-01

    Design and performance of high-T(sub c) dc superconducting quantum interference devices (SQUID's), junctions that comprise them, and magnetometers made from them are described, with attention to sources of 1/f noise. Biepitaxial junctions are found to have large levels of critical current fluctuations which make them unsuitable for low-noise SQUID's; this suggests a poorly connected interface at the grain boundary junction. SQUID's from bicrystal junctions have levels of critical current noise controllable using bias current reversal techniques which leave the noise white down to frequencies of a few Hz. A SQUID with an energy resolution of 1.5 x 10(exp -30) J Hz(exp -1) at 1 Hz is reported. Magnetometers in which a (9 mm)(exp 2) pickup loop is directly coupled to a SQUID body have achieved field resolutions of 93 fT Hz(exp -1/2) down to frequencies below 1 Hz, improving to 39 fT Hz(exp -1/2) at 1 Hz with the addition of a 50mm-diameter single-turn flux transformer. Poor coupling to pickup loop makes it difficult to satisfy competing goals of high field resolution and small detector size necessary for multichannel biomagnetic imaging. Improved coupling is demonstrated by the use of multiturn-input-coil flux transformers, and a resolution of 35 fT Hz(exp -1/2) in the white noise region is reported with a (10 mm)(exp 2) pickup loop. However, additional 1/f noise from processed multilayer structures in the transformer limits the resolution at 1 Hz to 114 fT Hz(exp -1/2). High-T(sub c) SQUID's exhibit additional 1/f noise when cooled in a nonzero static magnetic field because of additional flux vortices trapped in the film, with the noise power at 1 Hz typically increasing by a factor of 10-20 in a field of 0.05mT (0.5 G). Finally, a SQUID-based voltmeter with a resolution of 9.2 pV Hz(exp -1/2) at 10 Hz (24 pV Hz(exp -1/2) at 1 Hz) is described.

  17. Low-Frequency Noise in High-T Superconductor Josephson Junctions, Squids, and Magnetometers.

    Science.gov (United States)

    Miklich, Andrew Hostetler

    The design and performance of high-T_ {rm c} dc superconducting quantum interference devices (SQUIDs), the junctions that comprise them, and magnetometers made from them are described, with special attention paid to sources of 1/f noise. Biepitaxial junctions are found to have large levels of critical current fluctuations which make them unsuitable for low-noise SQUIDs. This noise suggests a poorly connected interface at the grain boundary junction. SQUIDs from bicrystal junctions, in contrast, have levels of critical current noise that are controllable using bias current reversal techniques which leave the noise white down to frequencies of a few Hz. A SQUID with an energy resolution of 1.5times 10^{-30} J Hz^ {-1} at 1 Hz is reported. Magnetometers in which a (9 mm)^2 pickup loop is directly coupled to a SQUID body have achieved field resolutions of 93 fT Hz^{-1/2} down to frequencies below 1 Hz, improving to 39 fT Hz^{-1/2} at 1 Hz with the addition of a 50 mm-diameter single-turn flux transformer. Although the performance of these devices is sufficient for single -channel biomagnetometry or geophysical studies, their relatively poor coupling to the pickup loop makes it difficult to satisfy the competing goals of high field resolution and small detector size necessary for multichannel biomagnetic imaging. Improved coupling is demonstrated by the use of multiturn-input-coil flux transformers, and a resolution of 35 fT Hz^{-1/2} in the white noise region is reported with a (10 mm) ^2 pickup loop. However, additional 1/f noise from the processed multilayer structures in the transformer limits the resolution at 1 Hz to 114 fT Hz^ {-1/2}. High-T_{ rm c} SQUIDs are shown to exhibit additional 1/f noise when they are cooled in a nonzero static magnetic field because of the additional flux vortices trapped in the film, with the noise power at 1 Hz typically increasing by a factor of 10-20 in a field of 0.05 mT (0.5 G). Finally, a SQUID-based voltmeter with a resolution

  18. Magsat - A new satellite to survey the earth's magnetic field

    Science.gov (United States)

    Mobley, F. F.; Eckard, L. D.; Fountain, G. H.; Ousley, G. W.

    1980-01-01

    The Magsat satellite was launched on Oct. 30, 1979 into a sun-synchronous dawn-dusk orbit, of 97 deg inclination, 350 km perigee, and 550 km apogee. It contains a precision vector magnetometer and a cesium-vapor scalar magnetometer at the end of a 6-m long graphite epoxy scissors boom. The magnetometers are accurate to 2 nanotesla. A pair of star cameras are used to define the body orientation to 10 arc sec rms. An 'attitude transfer system' measures the orientation of the magnetometer sensors relative to the star cameras to approximately 5 arc sec rms. The satellite position is determined to 70 meters rms by Doppler tracking. The overall objective is to determine each component of the earth's vector magnetic field to an accuracy of 6 nanotesla rms. The Magsat satellite gathers a complete picture of the earth's magnetic field every 12 hours. The vector components are sampled 16 times per second with a resolution of 0.5 nanotesla. The data will be used by the U.S. Geological Survey to prepare 1980 world magnetic field charts and to detect large-scale magnetic anomalies in the earth's crust for use in planning resource exploration strategy.

  19. Australian national proton facility

    International Nuclear Information System (INIS)

    Jackson, M.

    2000-01-01

    Full text: Proton therapy has been in use since 1954 and over 25,000 patients have been treated worldwide. Until recently most patients were treated at physics research facilities and apart from the Harvard Cyclotron Laboratory and some low energy machines for eye treatment, only small numbers of patients were treated in each centre and conditions were less than optimal. Limited beam time and lack of support facilities restricted the type of patient treated and conventional fractionation could not be used. The initial clinical experience was mainly with small tumours and other lesions close to critical organs. Large numbers of eye tumours have also been treated. Protons have a well-defined role in these situations and are now being used in the treatment of more common cancers. Since the development of hospital-based facilities, such as the one in Loma Linda in California, over 2,500 patients with prostate cancer have been treated using a simple technique which gives results at least as good as radical surgery, external beam radiotherapy or brachytherapy. Importantly, the incidence of severe complications is very low. There are encouraging results in many disease sites including lung, liver, soft tissue sarcomas and oesophagus. As proton therapy becomes more widely available, randomised trials comparing it with conventional radiotherapy or intensity modulated radiotherapy (IMRT) will be possible. In most situations the use of protons will enable a higher dose to be given safely but in situations where local control rates are already satisfactory, protons are expected to produce less complications than conventional treatment. The initial costs of a proton facility are high but the recurrent costs are similar to other forms of high technology radiotherapy. Simple treatment techniques with only a few fields are usually possible and proton therapy avoids the high integral doses associated with IMRT. This reduction in the low dose volume is likely to be particularly

  20. Adaption of the Magnetometer Towed Array geophysical system to meet Department of Energy needs for hazardous waste site characterization

    International Nuclear Information System (INIS)

    Cochran, J.R.; McDonald, J.R.; Russell, R.J.; Robertson, R.; Hensel, E.

    1995-10-01

    This report documents US Department of Energy (DOE)-funded activities that have adapted the US Navy's Surface Towed Ordnance Locator System (STOLS) to meet DOE needs for a ''... better, faster, safer and cheaper ...'' system for characterizing inactive hazardous waste sites. These activities were undertaken by Sandia National Laboratories (Sandia), the Naval Research Laboratory, Geo-Centers Inc., New Mexico State University and others under the title of the Magnetometer Towed Array (MTA)

  1. Auto-Calibration Methods of Kinematic Parameters and Magnetometer Offset for the Localization of a Tracked Mobile Robot

    OpenAIRE

    Luciano Cantelli; Samuel Ligama; Giovanni Muscato; Davide Spina

    2016-01-01

    This paper describes an automatic calibration procedure adopted to improve the localization of an outdoor mobile robot. The proposed algorithm estimates, by using an extended Kalman filter, the main kinematic parameters of the vehicles, such as the wheel radii and the wheelbase as well as the magnetometer offset. Several trials have been performed to validate the proposed strategy on a tracked electrical mobile robot. The mobile robot is aimed to be adopted as a tool to help humanitarian demi...

  2. Auto-Calibration Methods of Kinematic Parameters and Magnetometer Offset for the Localization of a Tracked Mobile Robot

    Directory of Open Access Journals (Sweden)

    Luciano Cantelli

    2016-11-01

    Full Text Available This paper describes an automatic calibration procedure adopted to improve the localization of an outdoor mobile robot. The proposed algorithm estimates, by using an extended Kalman filter, the main kinematic parameters of the vehicles, such as the wheel radii and the wheelbase as well as the magnetometer offset. Several trials have been performed to validate the proposed strategy on a tracked electrical mobile robot. The mobile robot is aimed to be adopted as a tool to help humanitarian demining operations.

  3. A wide-frequency range AC magnetometer to measure the specific absorption rate in nanoparticles for magnetic hyperthermia

    International Nuclear Information System (INIS)

    Garaio, E.; Collantes, J.M.; Garcia, J.A.; Plazaola, F.; Mornet, S.; Couillaud, F.; Sandre, O.

    2014-01-01

    Measurement of specific absorption rate (SAR) of magnetic nanoparticles is crucial to assert their potential for magnetic hyperthermia. To perform this task, calorimetric methods are widely used. However, those methods are not very accurate and are difficult to standardize. In this paper, we present AC magnetometry results performed with a lab-made magnetometer that is able to obtain dynamic hysteresis-loops in the AC magnetic field frequency range from 50 kHz to 1 MHz and intensities up to 24 kA m −1 . In this work, SAR values of maghemite nanoparticles dispersed in water are measured by AC magnetometry. The so-obtained values are compared with the SAR measured by calorimetric methods. Both measurements, by calorimetry and magnetometry, are in good agreement. Therefore, the presented AC magnetometer is a suitable way to obtain SAR values of magnetic nanoparticles. - Highlights: • We propose AC magnetometry as a method to measure the specific absorption rate (SAR) of magnetic nanoparticles suitable for magnetic hyperthermia therapy. • We have built a lab-made AC magnetometer, which is able to measure magnetic dynamic hysteresis-loops of nanoparticle dispersions. • The device works with AC magnetic field intensities up to 24 kA m −1 in a frequency range from 75 kHz to 1 MHz. • The SAR values of maghemite nanoparticles around 12 nm in magnetic diameter dispersed in water are measured by the lab-made magnetometer and different calorimetric methods. • Although all methods are in good agreement, several factors (probe location, thermal inertia, losses, etc.) make calorimetric method less accurate than AC magnetometry

  4. Apparatus for measurement of the electric dipole moment of the neutron using a cohabiting atomic-mercury magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Baker, C.A. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Chibane, Y.; Chouder, M. [University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Geltenbort, P. [Institut Laue-Langevin, BP 156, F-38042 Grenoble Cedex 9 (France); Green, K. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Harris, P.G., E-mail: p.g.harris@sussex.ac.uk [University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Heckel, B.R. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Iaydjiev, P.; Ivanov, S.N.; Kilvington, I. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Lamoreaux, S.K. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); May, D.J.; Pendlebury, J.M.; Richardson, J.D.; Shiers, D.B.; Smith, K.F. [University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Grinten, M. van der [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom)

    2014-02-01

    A description is presented of apparatus used to carry out an experimental search for an electric dipole moment of the neutron, at the Institut Laue-Langevin (ILL), Grenoble. The experiment incorporated a cohabiting atomic-mercury magnetometer in order to reduce spurious signals from magnetic field fluctuations. The result has been published in an earlier letter [1]; here, the methods and equipment used are discussed in detail.

  5. arXiv Search for magnetic monopoles with the MoEDAL forward trapping detector in 2.11 fb$^{-1}$ of 13 TeV proton-proton collisions at the LHC

    CERN Document Server

    Acharya, B.; The MoEDAL collaboration; Baines, S.; Benes, P.; Bergmann, B.; Bernabéu, J.; Bevan, A.; Branzas, H.; Campbell, M.; Caramete, L.; Cecchini, S.; de Montigny, M.; De Roeck, A.; Ellis, J.R.; Fairbairn, M.; Felea, D.; Frank, M.; Frekers, D.; Garcia, C.; Hays, J.; Hirt, A.M.; Janecek, J.; Kim, D.-W; Kinoshita, K.; Korzenev, A.; Lacarrère, D.H.; Lee, S.C.; Leroy, C.; Levi, G.; Lionti, A.; Mamuzic, J.; Margiotta, A.; Mauri, N.; Mavromatos, N.E.; Mermod, P.; Mitsou, V.A.; Orava, R.; Ostrovskiy, I.; Parker, B.; Patrizii, L.; Păvălaş, G.E.; Pinfold, J.L.; Popa, V.; Pozzato, M.; Pospisil, S.; Rajantie, A.; Ruiz de Austri, R.; Sahnoun, Z.; Sakellariadou, M.; Santra, A.; Sarkar, S.; Semenoff, G.; Shaa, A.; Sirri, G.; Sliwa, K.; Soluk, R.; Spurio, M.; Srivastava, Y.N.; Suk, M.; Swain, J.; Tenti, M.; Togo, V.; Tuszyński, J.A.; Vento, V.; Vives, O.; Vykydal, Z.; Widom, A.; Willems, G.; Yoon, J.H.; Zgura, I.S.

    2018-07-10

    We update our previous search for trapped magnetic monopoles in LHC Run 2 using nearly six times more integrated luminosity and including additional models for the interpretation of the data. The MoEDAL forward trapping detector, comprising 222~kg of aluminium samples, was exposed to 2.11~fb$^{-1}$ of 13 TeV proton-proton collisions near the LHCb interaction point and analysed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to the Dirac charge or above are excluded in all samples. The results are interpreted in Drell-Yan production models for monopoles with spins 0, 1/2 and 1: in addition to standard point-like couplings, we also consider couplings with momentum-dependent form factors. The search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.

  6. Protonation of pyridine. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Zahran, N F; Ghoniem, H; Helal, A I [Physics Dept., Nuclear Research Center, AEA., Cairo, (Egypt); Rasheed, N [Nuclear Material Authority, Cairo, (Egypt)

    1996-03-01

    Field ionization mass spectra of pyridine is measured using 10{mu}m activated wire. protonation of pyridine, is observed as an intense peak in the mass spectra. Charge distribution of pyridine molecule is calculated using the modified neglect of diatomic overlap (MNDO) technique, and consequently proton attachment is proposed to be on the nitrogen atom. Temperature dependence of (M+H){sup +} ion is investigated and discussed. MNDO calculations of the protonated species are done, and the proton affinity of pyridine molecule is estimated. Time dependence of the field ionization process of pyridine and protonated ions are observed and discussed. 5 figs.

  7. An ultra-sensitive and wideband magnetometer based on a superconducting quantum interference device

    Science.gov (United States)

    Storm, Jan-Hendrik; Hömmen, Peter; Drung, Dietmar; Körber, Rainer

    2017-02-01

    The magnetic field noise in superconducting quantum interference devices (SQUIDs) used for biomagnetic research such as magnetoencephalography or ultra-low-field nuclear magnetic resonance is usually limited by instrumental dewar noise. We constructed a wideband, ultra-low noise system with a 45 mm diameter superconducting pick-up coil inductively coupled to a current sensor SQUID. Thermal noise in the liquid helium dewar is minimized by using aluminized polyester fabric as superinsulation and aluminum oxide strips as heat shields. With a magnetometer pick-up coil in the center of the Berlin magnetically shielded room 2 (BMSR2), a noise level of around 150 aT Hz-1/2 is achieved in the white noise regime between about 20 kHz and the system bandwidth of about 2.5 MHz. At lower frequencies, the resolution is limited by magnetic field noise arising from the walls of the shielded room. Modeling the BMSR2 as a closed cube with continuous μ-metal walls, we can quantitatively reproduce its measured field noise.

  8. Swarm Deployable Boom Assembly (DBA) Development of a Deployable Magnetometer Boom for the Swarm Spacecraft

    Science.gov (United States)

    McMahon, Paul; Jung, Hans-Juergen; Edwards, Jeff

    2013-09-01

    The Swarm programme consists of 3 magnetically clean satellites flying in close formation designed to measure the Earth's magnetic field using 2 Magnetometers mounted on a 4.3m long deployable boom.Deployment is initiated by releasing 3 HDRMs, once released the boom oscillates back and forth on a pair of pivots, similar to a restaurant kitchen door hinge, for around 120 seconds before coming to rest on 3 kinematic mounts which are used to provide an accurate reference location in the deployed position. Motion of the boom is damped through a combination of friction, spring hysteresis and flexing of the 120+ cables crossing the hinge. Considerable development work and accurate numerical modelling of the hinge motion was required to predict performance across a wide temperature range and ensure that during the 1st overshoot the boom did not damage itself, the harness or the spacecraft.Due to the magnetic cleanliness requirements of the spacecraft no magnetic materials could be used in the design of the hardware.

  9. Evaluating detection and estimation capabilities of magnetometer-based vehicle sensors

    Science.gov (United States)

    Slater, David M.; Jacyna, Garry M.

    2013-05-01

    In an effort to secure the northern and southern United States borders, MITRE has been tasked with developing Modeling and Simulation (M&S) tools that accurately capture the mapping between algorithm-level Measures of Performance (MOP) and system-level Measures of Effectiveness (MOE) for current/future surveillance systems deployed by the the Customs and Border Protection Office of Technology Innovations and Acquisitions (OTIA). This analysis is part of a larger M&S undertaking. The focus is on two MOPs for magnetometer-based Unattended Ground Sensors (UGS). UGS are placed near roads to detect passing vehicles and estimate properties of the vehicle's trajectory such as bearing and speed. The first MOP considered is the probability of detection. We derive probabilities of detection for a network of sensors over an arbitrary number of observation periods and explore how the probability of detection changes when multiple sensors are employed. The performance of UGS is also evaluated based on the level of variance in the estimation of trajectory parameters. We derive the Cramer-Rao bounds for the variances of the estimated parameters in two cases: when no a priori information is known and when the parameters are assumed to be Gaussian with known variances. Sample results show that UGS perform significantly better in the latter case.

  10. In-Flight Calibration Methods for Temperature-Dependent Offsets in the MMS Fluxgate Magnetometers

    Science.gov (United States)

    Bromund, K. R.; Plaschke, F.; Strangeway, R. J.; Anderson, B. J.; Huang, B. G.; Magnes, W.; Fischer, D.; Nakamura, R.; Leinweber, H. K.; Russell, C. T.; hide

    2016-01-01

    During the first dayside season of the Magnetospheric Multiscale (MMS) mission, the in-flight calibration process for the Fluxgate magnetometers (FGM) implemented an algorithm that selected a constant offset (zero-level) for each sensor on each orbit. This method was generally able to reduce the amplitude of residual spin tone to less than 0.2 nT within the region of interest. However, there are times when the offsets do show significant short-term variations. These variations are most prominent in the nighttime season (phase 1X), when eclipses are accompanied by offset changes as large as 1 nT. Eclipses are followed by a recovery period as long as 12 hours where the offsets continue to change as temperatures stabilize. Understanding and compensating for these changes will become critical during Phase 2 of the mission in 2017, when the nightside will become the focus of MMS science. Although there is no direct correlation between offset and temperature, the offsets are seen for the period of any given week to be well-characterized as function of instrument temperature. Using this property, a new calibration method has been developed that has proven effective in compensating for temperature-dependent offsets during phase 1X of the MMS mission and also promises to further refine calibration quality during the dayside season.

  11. Analysis of digital fluxgate magnetometer and radon data of MPGO network in Kachchh

    International Nuclear Information System (INIS)

    Prasad, M.S.B.S.; Gupta, Arun; Pradhan, Rashmi; Rastogi, B.K.; Rawat, Gautam

    2010-01-01

    Institute of Seismological Research (ISR) has established a network of four Multi-parametric Geophysical Observatories (MPGO) at Bhachau, Vamka, Desalpar and Badargadh in Kachchh which fall in the aftershock zone of 2001 Bhuj earthquake (Mw 7.7) for earthquake prediction research. Two Magson digital fluxgate magnetometers (DFM) have been installed on February 07, 2009 to observe magnetic precursors, if any, at Desalpar and Vamka in Kachchh. The daily variations of geomagnetic horizontal and vertical components are being continuously observed at a sampling interval of 1 Hz. Variations of about 2-9 nT in vertical component have been observed during earthquakes of Mw = 4 occurring within a radius of 65 km from Vamka and 80 km from Desalpar. Conventional polarization analysis of DFM data is implemented to check lithospheric origin of electromagnetic signals. Geomagnetic transfer function is calculated to observe any subsurface conductivity variation beneath the measuring sites. Further a strong radon anomaly at Vamka and Chobari sites has been observed 7 days before Mw 4.1 earthquake of 12 April 2009 which is at a distance of 29 km W from Vamka and 23 Km SW from Chobari. DFM and Radon sensors were installed as a part of MPGO instruments and these data will be supplemented by several other parameters. Preliminary results will be presented and discussed in the meetings. (author)

  12. In-Flight Calibration Methods for Temperature-Dependendent Offsets in the MMS Fluxgate Magnetometers

    Science.gov (United States)

    Bromund, K. R.; Plaschke, F.; Strangeway, R. J.; Anderson, B. J.; Huang, B. G.; Magnes, W.; Fischer, D.; Nakamura, R.; Leinweber, H. K.; Russell, C. T.; Baumjohann, W.; Chutter, M.; Torbert, R. B.; Le, G.; Slavin, J. A.; Kepko, L.

    2016-12-01

    During the first dayside season of the Magnetospheric Multiscale (MMS) mission, the in-flight calibration process for the Fluxgate magnetometers (FGM) implemented an algorithm that selected a constant offset (zero-level) for each sensor on each orbit. This method was generally able to reduce the amplitude of residual spin tone to less than 0.2 nT within the region of interest. However, there are times when the offsets do show significant short-term variations. These variations are most prominent in the nighttime season (phase 1X), when eclipses are accompanied by offset changes as large as 1 nT. Eclipses are followed by a recovery period as long as 12 hours where the offsets continue to change as temperatures stabilize. Understanding and compensating for these changes will become critical during Phase 2 of the mission in 2017, when the nightside will become the focus of MMS science. Although there is no direct correlation between offset and temperature, the offsets are seen — for the period of any given week — to be well-characterized as function of instrument temperature. Using this property, a new calibration method has been developed that has proven effective in compensating for temperature-dependent offsets during phase 1X of the MMS mission and also promises to further refine calibration quality during the dayside season.

  13. Investigation of a low-cost magneto-inductive magnetometer for space science applications

    Directory of Open Access Journals (Sweden)

    L. H. Regoli

    2018-03-01

    Full Text Available A new sensor for measuring low-amplitude magnetic fields that is ideal for small spacecraft is presented. The novel measurement principle enables the fabrication of a low-cost sensor with low power consumption and with measuring capabilities that are comparable to recent developments for CubeSat applications. The current magnetometer, a software-modified version of a commercial sensor, is capable of detecting fields with amplitudes as low as 8.7 nT at 40 Hz and 2.7 nT at 1 Hz, with a noise floor of 4 pT∕Hz at 1 Hz. The sensor has a linear response to less than 3 % over a range of ±100 000 nT. All of these features make the magneto-inductive principle a promising technology for the development of magnetic sensors for both space-borne and ground-based applications to study geomagnetic activity.

  14. Real-space imaging of non-collinear antiferromagnetic order with a single-spin magnetometer

    Science.gov (United States)

    Gross, I.; Akhtar, W.; Garcia, V.; Martínez, L. J.; Chouaieb, S.; Garcia, K.; Carrétéro, C.; Barthélémy, A.; Appel, P.; Maletinsky, P.; Kim, J.-V.; Chauleau, J. Y.; Jaouen, N.; Viret, M.; Bibes, M.; Fusil, S.; Jacques, V.

    2017-09-01

    Although ferromagnets have many applications, their large magnetization and the resulting energy cost for switching magnetic moments bring into question their suitability for reliable low-power spintronic devices. Non-collinear antiferromagnetic systems do not suffer from this problem, and often have extra functionalities: non-collinear spin order may break space-inversion symmetry and thus allow electric-field control of magnetism, or may produce emergent spin-orbit effects that enable efficient spin-charge interconversion. To harness these traits for next-generation spintronics, the nanoscale control and imaging capabilities that are now routine for ferromagnets must be developed for antiferromagnetic systems. Here, using a non-invasive, scanning single-spin magnetometer based on a nitrogen-vacancy defect in diamond, we demonstrate real-space visualization of non-collinear antiferromagnetic order in a magnetic thin film at room temperature. We image the spin cycloid of a multiferroic bismuth ferrite (BiFeO3) thin film and extract a period of about 70 nanometres, consistent with values determined by macroscopic diffraction. In addition, we take advantage of the magnetoelectric coupling present in BiFeO3 to manipulate the cycloid propagation direction by an electric field. Besides highlighting the potential of nitrogen-vacancy magnetometry for imaging complex antiferromagnetic orders at the nanoscale, these results demonstrate how BiFeO3 can be used in the design of reconfigurable nanoscale spin textures.

  15. Remote sensing the plasmasphere, plasmapause, plumes and other features using ground-based magnetometers

    Directory of Open Access Journals (Sweden)

    Menk Frederick

    2014-01-01

    Full Text Available The plasmapause is a highly dynamic boundary between different magnetospheric particle populations and convection regimes. Some of the most important space weather processes involve wave-particle interactions in this region, but wave properties may also be used to remote sense the plasmasphere and plasmapause, contributing to plasmasphere models. This paper discusses the use of existing ground magnetometer arrays for such remote sensing. Using case studies we illustrate measurement of plasmapause location, shape and movement during storms; refilling of flux tubes within and outside the plasmasphere; storm-time increase in heavy ion concentration near the plasmapause; and detection and mapping of density irregularities near the plasmapause, including drainage plumes, biteouts and bulges. We also use a 2D MHD model of wave propagation through the magnetosphere, incorporating a realistic ionosphere boundary and Alfvén speed profile, to simulate ground array observations of power and cross-phase spectra, hence confirming the signatures of plumes and other density structures.

  16. Optimization of a digital SQUID magnetometer in terms of noise and distortion

    International Nuclear Information System (INIS)

    Haverkamp, I; Toepfer, H; Wetzstein, O; Kunert, J; Stolz, R; Meyer, H-G; Ortlepp, T

    2012-01-01

    The digital SQUID magnetometer takes advantage of flux quantization in a superconducting loop in order to measure magnetic fields. The core element of the digital SQUID is a Josephson comparator with a superconducting antenna loop attached to one of its junctions. Evaluation of the circuit from the system’s point of view requires an analysis in the frequency domain. In order to obtain a high-resolution fast Fourier transform, large datasets are necessary which are difficult to generate with transient simulation tools. In this work we derive a behavioural model for the digital SQUID in order to overcome restrictions imposed by transient simulation. By means of this model the influence of the comparator grey zone and the input loop inductance on the system performance was analysed. In order to assess the system, evaluation criteria based on the power spectral density were applied, which are commonly used for characterization of semiconductor analogue to digital converters. As a result of this study, design guidelines for an optimum antenna inductance depending on the comparator grey zone are derived, allowing us to achieve an optimum system performance in terms of noise and distortion. (paper)

  17. Infrastructure-Less Indoor Localization Using the Microphone, Magnetometer and Light Sensor of a Smartphone

    Directory of Open Access Journals (Sweden)

    Carlos E. Galván-Tejada

    2015-08-01

    Full Text Available In this paper, we present the development of an infrastructure-less indoor location system (ILS, which relies on the use of a microphone, a magnetometer and a light sensor of a smartphone, all three of which are essentially passive sensors, relying on signals available practically in any building in the world, no matter how developed the region is. In our work, we merge the information from those sensors to estimate the user’s location in an indoor environment. A multivariate model is applied to find the user’s location, and we evaluate the quality of the resulting model in terms of sensitivity and specificity. Our experiments were carried out in an office environment during summer and winter, to take into account changes in light patterns, as well as changes in the Earth’s magnetic field irregularities. The experimental results clearly show the benefits of using the information fusion of multiple sensors when contrasted with the use of a single source of information.

  18. Signal Conditioning for the Kalman Filter: Application to Satellite Attitude Estimation with Magnetometer and Sun Sensors.

    Science.gov (United States)

    Esteban, Segundo; Girón-Sierra, Jose M; Polo, Óscar R; Angulo, Manuel

    2016-10-31

    Most satellites use an on-board attitude estimation system, based on available sensors. In the case of low-cost satellites, which are of increasing interest, it is usual to use magnetometers and Sun sensors. A Kalman filter is commonly recommended for the estimation, to simultaneously exploit the information from sensors and from a mathematical model of the satellite motion. It would be also convenient to adhere to a quaternion representation. This article focuses on some problems linked to this context. The state of the system should be represented in observable form. Singularities due to alignment of measured vectors cause estimation problems. Accommodation of the Kalman filter originates convergence difficulties. The article includes a new proposal that solves these problems, not needing changes in the Kalman filter algorithm. In addition, the article includes assessment of different errors, initialization values for the Kalman filter; and considers the influence of the magnetic dipole moment perturbation, showing how to handle it as part of the Kalman filter framework.

  19. Detecting molecules and cells labeled with magnetic particles using an atomic magnetometer

    International Nuclear Information System (INIS)

    Yu Dindi; Ruangchaithaweesuk, Songtham; Yao Li; Xu Shoujun

    2012-01-01

    The detection of magnetically labeled molecules and cells involves three essential parameters: sensitivity, spatial resolution, and molecular specificity. We report on the use of atomic magnetometry and its derivative techniques to achieve high performance in terms of all these parameters. With a sensitivity of 80 fT/√Hz for dc magnetic fields, we show that 7,000 streptavidin-conjugated magnetic microparticles magnetized by a permanent magnet produce a magnetic field of 650 pT; this result predicts that a single such particle can be detected during one second of signal averaging. Spatial information is obtained using a scanning magnetic imaging scheme. The spatial resolution is 20 μm with a detection distance of more than 1 cm; this distance is much longer than that in previous reports. The molecular specificity is achieved using force-induced remnant magnetization spectroscopy, which currently uses an atomic magnetometer for detection. As an example, we perform measurement of magnetically labeled human CD4+ T cells, whose count in the blood is the diagnostic criterion for human immunodeficiency virus infection. Magnetic particles that are specifically bound to the cells are resolved from nonspecifically bound particles and quantitatively correlate with the number of cells. The magnetic particles have an overall size of 2.8 μm, with a magnetic core in nanometer regime. The combination of our techniques is predicted to be useful in molecular and cellular imaging.

  20. Detection of Target ssDNA Using a Microfabricated Hall Magnetometer with Correlated Optical Readout

    Directory of Open Access Journals (Sweden)

    Steven M. Hira

    2012-01-01

    Full Text Available Sensing biological agents at the genomic level, while enhancing the response time for biodetection over commonly used, optics-based techniques such as nucleic acid microarrays or enzyme-linked immunosorbent assays (ELISAs, is an important criterion for new biosensors. Here, we describe the successful detection of a 35-base, single-strand nucleic acid target by Hall-based magnetic transduction as a mimic for pathogenic DNA target detection. The detection platform has low background, large signal amplification following target binding and can discriminate a single, 350 nm superparamagnetic bead labeled with DNA. Detection of the target sequence was demonstrated at 364 pM (<2 target DNA strands per bead target DNA in the presence of 36 μM nontarget (noncomplementary DNA (<10 ppm target DNA using optical microscopy detection on a GaAs Hall mimic. The use of Hall magnetometers as magnetic transduction biosensors holds promise for multiplexing applications that can greatly improve point-of-care (POC diagnostics and subsequent medical care.

  1. Anisotropic effects in a powder oriented YBCO sample using a three axes magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Boudissa, M. [Universite Ferhat Abbas, Faculte des Sciences de l' Ingenieur, Setif (Algeria); Halimi, R. [Universite Mentouri, Unite de Recherche de Physique des Materiaux, Constantine (Algeria); Senoussi, S. [Universite Paris-Sud, Laboratoire de Physique des Solides, Orsay (France)

    2006-09-15

    To measure the components of the magnetization vector along the XYZ directions of a reference frame, in the superconducting materials, we have conceived a three axes magnetometer, with a detection system equipped with three series of pick-up coils with axes parallel to the three directions X,Y, and Z. We describe in this paper the details of the design and the method of measurement, with some results obtained by magnetic measurements on samples of oriented YBCO powder, with size of the grains between 20 {mu}m and 40 {mu}m, for values of the angle {theta} between the magnetic field H and the c-axis, between 0 and 90 and for values of fields up to 12 T. The direct measurement of the Z and the XY components of the irreversible magnetization vector, M{sub irr}, allowed us to observe the twin effect (channeling) on the vortex pinning observed by many authors, the evolution of the magnetization vector and to measure with a high accuracy the anisotropy factor of our samples. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Anisotropic effects in a powder oriented YBCO sample using a three axes magnetometer

    International Nuclear Information System (INIS)

    Boudissa, M.; Halimi, R.; Senoussi, S.

    2006-01-01

    To measure the components of the magnetization vector along the XYZ directions of a reference frame, in the superconducting materials, we have conceived a three axes magnetometer, with a detection system equipped with three series of pick-up coils with axes parallel to the three directions X,Y, and Z. We describe in this paper the details of the design and the method of measurement, with some results obtained by magnetic measurements on samples of oriented YBCO powder, with size of the grains between 20 μm and 40 μm, for values of the angle θ between the magnetic field H and the c-axis, between 0 and 90 and for values of fields up to 12 T. The direct measurement of the Z and the XY components of the irreversible magnetization vector, M irr , allowed us to observe the twin effect (channeling) on the vortex pinning observed by many authors, the evolution of the magnetization vector and to measure with a high accuracy the anisotropy factor of our samples. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Signal Conditioning for the Kalman Filter: Application to Satellite Attitude Estimation with Magnetometer and Sun Sensors

    Directory of Open Access Journals (Sweden)

    Segundo Esteban

    2016-10-01

    Full Text Available Most satellites use an on-board attitude estimation system, based on available sensors. In the case of low-cost satellites, which are of increasing interest, it is usual to use magnetometers and Sun sensors. A Kalman filter is commonly recommended for the estimation, to simultaneously exploit the information from sensors and from a mathematical model of the satellite motion. It would be also convenient to adhere to a quaternion representation. This article focuses on some problems linked to this context. The state of the system should be represented in observable form. Singularities due to alignment of measured vectors cause estimation problems. Accommodation of the Kalman filter originates convergence difficulties. The article includes a new proposal that solves these problems, not needing changes in the Kalman filter algorithm. In addition, the article includes assessment of different errors, initialization values for the Kalman filter; and considers the influence of the magnetic dipole moment perturbation, showing how to handle it as part of the Kalman filter framework.

  4. Vector magnetometer based on synchronous manipulation of nitrogen-vacancy centers in all crystal directions

    Science.gov (United States)

    Zhang, Chen; Yuan, Heng; Zhang, Ning; Xu, Lixia; Zhang, Jixing; Li, Bo; Fang, Jiancheng

    2018-04-01

    Negatively charged nitrogen vacancy (NV‑) centers in diamond have been extensively studied as high-sensitivity magnetometers, showcasing a wide range of applications. This study experimentally demonstrates a vector magnetometry scheme based on synchronous manipulation of NV‑ center ensembles in all crystal directions using double frequency microwaves (MWs) and multi-coupled-strip-lines (mCSL) waveguide. The application of the mCSL waveguide ensures a high degree of synchrony (99%) for manipulating NV‑ centers in multiple orientations in a large volume. Manipulation with double frequency MWs makes NV‑ centers of all four crystal directions involved, and additionally leads to an enhancement of the manipulation field. In this work, by monitoring the changes in the slope of the resonance line consisting of multi-axes NV‑ centers, measurement of the direction of the external field vector was demonstrated with a sensitivity of {{10}\\prime}/\\sqrt{Hz} . Based on the scheme, the fluorescence signal contrast was improved by four times higher and the sensitivity to the magnetic field strength was improved by two times. The method provides a more practical way of achieving vector sensors based on NV‑ center ensembles in diamond.

  5. Global measures of ionospheric electrodynamic activity inferred from combined incoherent scatter radar and ground magnetometer observations

    International Nuclear Information System (INIS)

    Richmond, A.D.; Kamide, Y.; Akasofu, S.I.; Alcayde, D.; Blanc, M.; De LaBeaujardiere, O.; Evans, D.S.; Foster, J.C.; Holt, J.M.; Friis-Christensen, E.; Pellinen, R.J.; Senior, C.; Zaitzev, A.N.

    1990-01-01

    An analysis of several global measures of high-latitude ionospheric electrodynamic activity is undertakn on the basis of results obtained from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure applied to incoherent scatter radar and ground magnetometer observatons for January 18-19, 1984. Different global measures of electric potentials, currents, resistances, and energy transfer from the magnetosphere show temporal variations that are generally well correlated. The authors present parameterizations of thees quantities in terms of the AE index and the hemispheric power index of precipitating auroral particles. It is shown how error estimates of the mapped electric fields can be used to correct the estimation of Joule heating. Global measures of potential drop, field-aligned current, and Joule heating as obtained by the AMIE procedure are compared with similar measures presented in previous studies. Agreement is found to within the uncertainties inherent in each study. The mean potential drop through which field-aligned currents flow in closing through the ionosphere is approximately 28% of the total polar cap potential drop under all conditions during these 2 days. They note that order-of-magnitude differences can appear when comparing different global measures of total electric current flow and of effective resistances of the global circuit, so that care must be exercised in choosing characteristic values of these parameters for circuit-analogy studies of ionosphere-magnetosphere electrodynamic coupling

  6. Detecting molecules and cells labeled with magnetic particles using an atomic magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Yu Dindi; Ruangchaithaweesuk, Songtham; Yao Li; Xu Shoujun, E-mail: sxu7@uh.edu [University of Houston, Department of Chemistry (United States)

    2012-09-15

    The detection of magnetically labeled molecules and cells involves three essential parameters: sensitivity, spatial resolution, and molecular specificity. We report on the use of atomic magnetometry and its derivative techniques to achieve high performance in terms of all these parameters. With a sensitivity of 80 fT/{radical}Hz for dc magnetic fields, we show that 7,000 streptavidin-conjugated magnetic microparticles magnetized by a permanent magnet produce a magnetic field of 650 pT; this result predicts that a single such particle can be detected during one second of signal averaging. Spatial information is obtained using a scanning magnetic imaging scheme. The spatial resolution is 20 {mu}m with a detection distance of more than 1 cm; this distance is much longer than that in previous reports. The molecular specificity is achieved using force-induced remnant magnetization spectroscopy, which currently uses an atomic magnetometer for detection. As an example, we perform measurement of magnetically labeled human CD4+ T cells, whose count in the blood is the diagnostic criterion for human immunodeficiency virus infection. Magnetic particles that are specifically bound to the cells are resolved from nonspecifically bound particles and quantitatively correlate with the number of cells. The magnetic particles have an overall size of 2.8 {mu}m, with a magnetic core in nanometer regime. The combination of our techniques is predicted to be useful in molecular and cellular imaging.

  7. Flux-gate magnetometer spin axis offset calibration using the electron drift instrument

    International Nuclear Information System (INIS)

    Plaschke, Ferdinand; Nakamura, Rumi; Baumjohann, Wolfgang; Steller, Manfred; Magnes, Werner; Leinweber, Hannes K; Chutter, Mark; Vaith, Hans

    2014-01-01

    Spin-stabilization of spacecraft immensely supports the in-flight calibration of on-board flux-gate magnetometers (FGMs). From 12 calibration parameters in total, 8 can be easily obtained by spectral analysis. From the remaining 4, the spin axis offset is known to be particularly variable. It is usually determined by analysis of Alfvénic fluctuations that are embedded in the solar wind. In the absence of solar wind observations, the spin axis offset may be obtained by comparison of FGM and electron drift instrument (EDI) measurements. The aim of our study is to develop methods that are readily usable for routine FGM spin axis offset calibration with EDI. This paper represents a major step forward in this direction. We improve an existing method to determine FGM spin axis offsets from EDI time-of-flight measurements by providing it with a comprehensive error analysis. In addition, we introduce a new, complementary method that uses EDI beam direction data instead of time-of-flight data. Using Cluster data, we show that both methods yield similarly accurate results, which are comparable yet more stable than those from a commonly used solar wind-based method. (paper)

  8. DESIGN AND CALIBRATION OF A VIBRANT SAMPLE MAGNETOMETER: CHARACTERIZATION OF MAGNETIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Freddy P. Guachun

    2018-01-01

    Full Text Available This paper presents the process followed in the implementation of a vibrating sample magnetometer (VSM, constructed with materials commonly found in an electromagnetism laboratory. It describes the design, construction, calibration and use in the characterization of some magnetic materials. A VSM measures the magnetic moment of a sample when it is vibrated perpendicular to a uniform magnetic field; Magnetization and magnetic susceptibility can be determined from these readings. This instrument stands out for its simplicity, versatility and low cost, but it is very sensitive and capable of eliminating or minimizing many sources of error that are found in other methods of measurement, allowing to obtain very accurate and reliable results. Its operation is based on the law of magnetic induction of Lenz-Faraday that consists in measuring the induced voltage in coils of detection produced by the variation of the magnetic flux that crosses them. The calibration of the VSM was performed by means of a standard sample (Magnetite and verified by means of a test sample (Nickel.

  9. Calibration of Helmholtz Coils for the characterization of MEMS magnetic sensor using fluxgate magnetometer with DAS1 magnetic range data acquisition system

    Science.gov (United States)

    Ahmad, Farooq; Dennis, John Ojur; Md Khir, Mohd Haris; Hamid, Nor Hisham

    2012-09-01

    This paper presents the calibration of Helmholtz coils for the characterization of MEMS Magnetic sensor using Fluxgate magnetometer with DAS1 Magnetic Range Data Acquisition System. The Helmholtz coils arrangement is often used to generate a uniform magnetic field in space. In the past, standard magnets were used to calibrate the Helmholtz coils. A method is presented here for calibrating these coils using a Fluxgate magnetometer and known current source, which is easier and results in greater accuracy.

  10. Coupled-core fluxgate magnetometer: Novel configuration scheme and the effects of a noise-contaminated external signal

    International Nuclear Information System (INIS)

    Palacios, Antonio; Aven, John; In, Visarath; Longhini, Patrick; Kho, Andy; Neff, Joseph D.; Bulsara, Adi

    2007-01-01

    Recent theoretical and experimental work has shown that unidirectional coupling can induce oscillations in overdamped and undriven nonlinear dynamical systems that are non-oscillatory when uncoupled; in turn, this has been shown to lead to new mechanisms for weak (compared to the energy barrier height) signal detection and amplification. The potential applications include fluxgate magnetometers, electric field sensors, and arrays of Superconducting Quantum Interference Device (SQUID) rings. In the particular case of the fluxgate magnetometer, we have developed a ''coupled-core fluxgate magnetometer'' (CCFM); this device has been realized in the laboratory and its dynamics used to quantify many properties that are generic to this class of systems and coupling. The CCFM operation is underpinned by the emergent oscillatory behavior in a unidirectionally coupled ring of wound ferromagnetic cores, each of which can be treated as an overdamped bistable dynamic system when uncoupled. In particular, one can determine the regimes of existence and stability of the (coupling-induced) oscillations, and the scaling behavior of the oscillation frequency. More recently, we studied the effects of a (Gaussian) magnetic noise floor on a CCFM system realized with N=3 coupled ferromagnetic cores. In this Letter, we first introduce a variation on the basic CCFM configuration that affords a path to enhanced device sensitivity, particularly for N>=3 coupled elements. We then analyze the response of the basic CCFM configuration as well as the new setup to a dc target signal that has a small noisy component (or ''contamination'')

  11. In-flight calibration of the spin axis offset of a fluxgate magnetometer with an electron drift instrument

    Science.gov (United States)

    Leinweber, H. K.; Russell, C. T.; Torkar, K.

    2012-10-01

    We show that the spin axis offset of a fluxgate magnetometer can be calibrated with an electron drift instrument (EDI) and that the required input time interval is relatively short. For missions such as Cluster or the upcoming Magnetospheric Multiscale (MMS) mission the spin axis offset of a fluxgate magnetometer could be determined on an orbital basis. An improvement of existing methods for finding spin axis offsets via comparison of accurate measurements of the field magnitude is presented, that additionally matches the gains of the two instruments that are being compared. The technique has been applied to EDI data from the Cluster Active Archive and fluxgate magnetometer data processed with calibration files also from the Cluster Active Archive. The method could prove to be valuable for the MMS mission because the four MMS spacecraft will only be inside the interplanetary field (where spin axis offsets can be calculated from Alfvénic fluctuations) for short periods of time and during unusual solar wind conditions.

  12. A method for combining search coil and fluxgate magnetometer data to reveal finer structures in reconnection physics

    Science.gov (United States)

    Argall, M. R.; Caide, A.; Chen, L.; Torbert, R. B.

    2012-12-01

    Magnetometers have been used to measure terrestrial and extraterrestrial magnetic fields in space exploration ever since Sputnik 3. Modern space missions, such as Cluster, RBSP, and MMS incorporate both search coil magnetometers (SCMs) and fluxgate magnetometers (FGMs) in their instrument suites: FGMs work well at low frequencies while SCMs perform better at high frequencies. In analyzing the noise floor of these instruments, a cross-over region is apparent around 0.3-1.5Hz. The satellite separation of MMS and average speeds of field convection and plasma flows at the subsolar magnetopause make this a crucial range for the upcoming MMS mission. The method presented here combines the signals from SCM and FGM by taking a weighted average of both in this frequency range in order to draw out key features, such as narrow current sheet structures, that would otherwise not be visible. The technique is applied to burst mode Cluster data for reported magnetopause and magnetotail reconnection events to demonstrate the power of the combined data. This technique is also applied to data from the the EMFISIS instrument on the RBSP mission. The authors acknowledge and thank the FGM and STAFF team for the use of their data from the CLUSTER Active Archive.

  13. In-flight calibration of the spin axis offset of a fluxgate magnetometer with an electron drift instrument

    International Nuclear Information System (INIS)

    Leinweber, H K; Russell, C T; Torkar, K

    2012-01-01

    We show that the spin axis offset of a fluxgate magnetometer can be calibrated with an electron drift instrument (EDI) and that the required input time interval is relatively short. For missions such as Cluster or the upcoming Magnetospheric Multiscale (MMS) mission the spin axis offset of a fluxgate magnetometer could be determined on an orbital basis. An improvement of existing methods for finding spin axis offsets via comparison of accurate measurements of the field magnitude is presented, that additionally matches the gains of the two instruments that are being compared. The technique has been applied to EDI data from the Cluster Active Archive and fluxgate magnetometer data processed with calibration files also from the Cluster Active Archive. The method could prove to be valuable for the MMS mission because the four MMS spacecraft will only be inside the interplanetary field (where spin axis offsets can be calculated from Alfvénic fluctuations) for short periods of time and during unusual solar wind conditions. (paper)

  14. CalMagNet – an array of search coil magnetometers monitoring ultra low frequency activity in California

    Directory of Open Access Journals (Sweden)

    C. Dunson

    2008-04-01

    Full Text Available The California Magnetometer Network (CalMagNet consists of sixty-eight triaxial search-coil magnetometer systems measuring Ultra Low Frequency (ULF, 0.001–16 Hz, magnetic field fluctuations in California. CalMagNet provides data for comprehensive multi-point measurements of specific events in the Pc 1–Pc 5 range at mid-latitudes as well as a systematic, long-term study of ULF signals in active fault regions in California. Typical events include geomagnetic micropulsations and spectral resonant structures associated with the ionospheric Alfvén resonator. This paper provides a technical overview of the CalMagNet sensors and data processing systems. The network is composed of ten reference stations and fifty-eight local monitoring stations. The primary instruments at each site are three orthogonal induction coil magnetometers. A geophone monitors local site vibration. The systems are designed for future sensor expansion and include resources for monitoring four additional channels. Data is currently sampled at 32 samples per second with a 24-bit converter and time tagged with a GPS-based timing system. Several examples of representative magnetic fluctuations and signals as measured by the array are given.

  15. Geophysical survey at Tell Barri (Syria)

    Science.gov (United States)

    Florio, Giovanni; Cella, Federico; Pierobon, Raffaella; Castaldo, Raffaele; Castiello, Gabriella; Fedi, Maurizio

    2010-05-01

    A geophysical survey at the archaeological site of Tell Barri (Northeasterm Syria) was carried out. The Tell (Arab word for "hill") is 32 m high with a whole covered area of 37 hectares. The Tell, with its huge dimensions and with a great amount of pottery on the surface, is a precious area to study the regional history from IV mill. BC to Islamic and Medieval period. The geophysical study consisted in magnetic and electromagnetic measurements in the lower town area. The aim of this survey was to provide evidence of the presence of buried archaeological structures around an already excavated area. The wall structures in the Tell Barri are made by backed or crude clay bricks. The instrument used for the magnetic survey was an Overhauser-effect proton magnetometer (Gem GSM-19GF), in gradiometric configuration. The electromagnetic instrument used, Geonics Ltd. EM31, implements a Frequency Domain Electromagnetic Method (FDEM). It was used in vertical coils configuration, and this choice should grant a maximum theoretical investigation depth of about 6 m. Before starting the measurements on a larger scale, we conducted a magnetic and EM test profile on some already excavated, outcropping, baked bricks walls. Results were encouraging, because clear and strong magnetic and EM anomalies were recorded over the outcropping walls. However, in the survey area these structures are covered by 3 to 4 meters of clay material and the increased sensors-structures distance will reduce the anomalies amplitude. Moreover, the cover material is disseminated with bricks, basalt blocks and ceramics, all of which have relevant magnetic properties. After magnetic surveying some 50 m side square areas, we verified that unfortunately their effect resulted to be dominant with respect to the deeper wall structures, degrading too much the signal-to-noise ratio. The processing and analysis of magnetic data is however currently underway and will determine decisions about further use of this method

  16. Proton transfer events in GFP.

    Science.gov (United States)

    Di Donato, Mariangela; van Wilderen, Luuk J G W; Van Stokkum, Ivo H M; Stuart, Thomas Cohen; Kennis, John T M; Hellingwerf, Klaas J; van Grondelle, Rienk; Groot, Marie Louise

    2011-09-28

    Proton transfer is one of the most important elementary processes in biology. Green fluorescent protein (GFP) serves as an important model system to elucidate the mechanistic details of this reaction, because in GFP proton transfer can be induced by light absorption. Illumination initiates proton transfer through a 'proton-wire', formed by the chromophore (the proton donor), water molecule W22, Ser205 and Glu222 (the acceptor), on a picosecond time scale. To obtain a more refined view of this process, we have used a combined approach of time resolved mid-infrared spectroscopy and visible pump-dump-probe spectroscopy to resolve with atomic resolution how and how fast protons move through this wire. Our results indicate that absorption of light by GFP induces in 3 ps (10 ps in D(2)O) a shift of the equilibrium positions of all protons in the H-bonded network, leading to a partial protonation of Glu222 and to a so-called low barrier hydrogen bond (LBHB) for the chromophore's proton, giving rise to dual emission at 475 and 508 nm. This state is followed by a repositioning of the protons on the wire in 10 ps (80 ps in D(2)O), ultimately forming the fully deprotonated chromophore and protonated Glu222.

  17. Solar proton fluxes since 1956

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1977-01-01

    The fluxes of protons emitted during solar flares since 1956 were evaluated. The depth-versus-activity profiles of 56 Co in several lunar rocks are consistent with the solar-proton fluxes detected by experiments on several satellites. Only about 20% of the solar-proton-induced activities of 22 Na and 55 Fe in lunar rocks from early Apollo missions were produced by protons emitted from the sun during solar cycle 20 (1965--1975). The depth-versus-activity data for these radionuclides in several lunar rocks were used to determine the fluxes of protons during solar cycle 19 (1954--1964). The average proton fluxes for cycle 19 are about five times those for both the last million years and for cycle 20. These solar-proton flux variations correlate with changes in sunspot activity

  18. Airborne gamma-ray spectrometer and magnetometer survey: Indian Wells, Texas. Final report. Detail area, Volume IIB

    International Nuclear Information System (INIS)

    Volume IIB contains appendices for: flight line maps; geology maps; explanation of geologic legend; flight line/geology maps; radiometric contour maps; magnetic contour maps; geochemical factor analysis maps

  19. Airborne gamma-ray spectrometer and magnetometer survey: Cameron A, Arizona, detail area. Volume II A. Final report

    International Nuclear Information System (INIS)

    1983-01-01

    Volume II A contains appendices for: stacked profiles; geologic histograms; geochemical histograms; speed and altitude histograms; geologic statistical tables; geochemical statistical tables; magnetic and ancillary profiles; and test line data

  20. Airborne gamma-ray spectrometer and magnetometer survey, Durango C, Colorado. Final report Volume II A. Detail area

    International Nuclear Information System (INIS)

    1983-01-01

    Geology of Durango C detail area, radioactive mineral occurrences in Colorado, and geophysical data interpretation are included in this report. Eight appendices provide: stacked profiles, geologic histograms, geochemical histograms, speed and altitude histograms, geologic statistical tables, magnetic and ancillary profiles, and test line data

  1. Airborne gamma-ray spectrometer and magnetometer survey, Durango D, Colorado. Final report Volume II A. Detail area

    International Nuclear Information System (INIS)

    1983-01-01

    This volume contains geology of the Durango D detail area, radioactive mineral occurrences in Colorado, and geophysical data interpretation. Eight appendices provide: stacked profiles, geologic histograms, geochemical histograms, speed and altitude histograms, geologic statistical tables, geochemical statistical tables, magnetic and ancillary profiles, and test line data

  2. Airborne gamma-ray spectrometer and magnetometer survey, Durango B, Colorado. Final report Volume II A. Detail area

    International Nuclear Information System (INIS)

    1983-01-01

    The geology of the Durango B detail area, the radioactive mineral occurrences in Colorado and the geophysical data interpretation are included in this report. Seven appendices contain: stacked profiles, geologic histograms, geochemical histograms, speed and altitude histograms, geologic statistical tables, geochemical statistical tables, and test line data

  3. Airborne gamma-ray spectrometer and magnetometer survey, Durango A, Colorado. Final report Volume II A. Detail area

    International Nuclear Information System (INIS)

    1983-01-01

    This volume contains geology of the Durango A detail area, radioactive mineral occurences in Colorado, and geophysical data interpretation. Eight appendices provide the following: stacked profiles, geologic histograms, geochemical histograms, speed and altitude histograms, geologic statistical tables, geochemical statistical tables, magnetic and ancillary profiles, and test line data

  4. Airborne gamma-ray spectrometer and magnetometer survey: Monument Valley B, Utah, detail area. Volume II A. Final report

    International Nuclear Information System (INIS)

    1983-01-01

    Volume II A contains appendices for: stacked profiles; geologic histograms; geochemical histograms; speed and altitude histograms; geologic statistical tables; geochemical statistical tables; magnetic and ancillary profiles; and test line data

  5. Airborne gamma-ray spectrometer and magnetometer survey: Monument Valley B, Utah, detail area. Volume II B. Final report

    International Nuclear Information System (INIS)

    1983-01-01

    Volume II B contains appendices for: flight line maps; geology maps; explanation of geologic legend; flight line/geology maps; radiometric contour maps; magnetic contour maps; and geochemical factor analysis maps

  6. Airborne gamma-ray spectrometer and magnetometer survey, Durango D, Colorado. Final report Volume II B. Detail area

    International Nuclear Information System (INIS)

    1983-01-01

    This volume comprises eight appendices containing the following information for the Durango D detail area: flight line maps, geology maps, explanation of geologic legend, flight line/geology maps, radiometric contour maps, magnetic contour maps, multi-variant analysis maps, and geochemical factor analysis maps

  7. Airborne gamma-ray spectrometer and magnetometer survey: Monument Valley A, Utah, detail area. Volume II B. Final report

    International Nuclear Information System (INIS)

    1983-01-01

    Volume II B contains appendices for: flight line maps; geology maps; explanation of geologic legend; flight line/geology maps; radiometric contour maps; magnetic contour maps; multi-variant analysis maps; and geochemical factor analysis maps

  8. Proton mass decomposition

    Science.gov (United States)

    Yang, Yi-Bo; Chen, Ying; Draper, Terrence; Liang, Jian; Liu, Keh-Fei

    2018-03-01

    We report the results on the proton mass decomposition and also on the related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensembles of Nf = 2 + 1 DWF configurations with three lattice spacings and volumes, and several pion masses including the physical pion mass. With 1-loop pertur-bative calculation and proper normalization of the glue operator, we find that the u, d, and s quark masses contribute 9(2)% to the proton mass. The quark energy and glue field energy contribute 31(5)% and 37(5)% respectively in the MS scheme at µ = 2 GeV. The trace anomaly gives the remaining 23(1)% contribution. The u, d, s and glue momentum fractions in the MS scheme are consistent with the global analysis at µ = 2 GeV.

  9. Proton solar flares

    International Nuclear Information System (INIS)

    Shaposhnikova, E.F.

    1979-01-01

    The observations of proton solar flares have been carried out in 1950-1958 using the extrablackout coronograph of the Crimea astrophysical observatory. The experiments permit to determine two characteristic features of flares: the directed motion of plasma injection flux from the solar depths and the appearance of a shock wave moving from the place of the injection along the solar surface. The appearance of the shock wave is accompanied by some phenomena occuring both in the sunspot zone and out of it. The consistent flash of proton flares in the other groups of spots, the disappearance of fibres and the appearance of eruptive prominences is accomplished in the sunspot zone. Beyond the sunspot zone the flares occur above spots, the fibres disintegrate partially or completely and the eruptive prominences appear in the regions close to the pole

  10. The Amsterdam proton microbeam

    International Nuclear Information System (INIS)

    Bos, A.J.J.

    1984-01-01

    The aim of the work presented in this thesis is to develop a microbeam setup such that small beam spot sizes can be produced routinely, and to investigate the capabilities of the setup for micro-PIXE analysis. The development and performance of the Amsterdam proton microbeam setup are described. The capabilities of the setup for micro-PIXE are shown with an investigation into the presence of trace elements in human hair. (Auth.)

  11. The proton radius puzzle

    Science.gov (United States)

    Bonesini, Maurizio

    2017-12-01

    The FAMU (Fisica degli Atomi Muonici) experiment has the goal to measure precisely the proton Zemach radius, thus contributing to the solution of the so-called proton radius "puzzle". To this aim, it makes use of a high-intensity pulsed muon beam at RIKEN-RAL impinging on a cryogenic hydrogen target with an high-Z gas admixture and a tunable mid-IR high power laser, to measure the hyperfine (HFS) splitting of the 1S state of the muonic hydrogen. From the value of the exciting laser frequency, the energy of the HFS transition may be derived with high precision ( 10-5) and thus, via QED calculations, the Zemach radius of the proton. The experimental apparatus includes a precise fiber-SiPMT beam hodoscope and a crown of eight LaBr3 crystals and a few HPGe detectors for detection of the emitted characteristic X-rays. Preliminary runs to optimize the gas target filling and its operating conditions have been taken in 2014 and 2015-2016. The final run, with the pump laser to drive the HFS transition, is expected in 2018.

  12. Heavy quarks in proton

    CERN Document Server

    AUTHOR|(SzGeCERN)655637

    The measurement of prompt photon associated with a b jet in proton-proton interactions can provide us insight into the inner structure of proton. This is because precision of determination of parton distribution functions of b quark and gluon can be increased by such a measurement. The measurement of cross-section of prompt photon associated with a b jet (process $pp\\longrightarrow \\gamma + b + X$) at $\\sqrt{s}$= 8 TeV with the ATLAS detector is presented. Full 8 TeV dataset collected by ATLAS during the year 2012 was used in this analysis. Corresponding integrated luminosity is 20.3 $fb^{-1}$. Fiducial differential cross-section as a function of photon transverse momentum at particle level was extracted from data and compared with the prediction of leading order event generator Pythia 8. Cross-section extracted from data is normalised independently on the Monte Carlo prediction. Values of data distribution lie above Monte Carlo values. The difference can be explained by presence of higher order effects not ...

  13. Geophysical survey at archaeological sites in northeastern Syria

    OpenAIRE

    Mateiciucová, Inna; Milo, Peter; Tencer, Tomáš; Vlach, Marek

    2011-01-01

    From August 25 to September 4, 2008, geophysical surveys were carried out at the Neolithic, Chalcolithic, Bronze and Iron Age tell- and non-tell settlements in the Khabur region in Northeastern Syria (Syrian-Polish-Czech expedition) (Fig. 1). Four sites were prospected: Tell Arbid Abyad, Tell Arbid (West-hill), Khirbet Shane, Khirbet Bezi. The Scintrex Navmag SM-5 – Caesium Magnetometer was used for the measurement of the vertical gradient of the local magnetic field. The measurement resoluti...

  14. [Why proton therapy? And how?

    Science.gov (United States)

    Thariat, Juliette; Habrand, Jean Louis; Lesueur, Paul; Chaikh, Abdulhamid; Kammerer, Emmanuel; Lecomte, Delphine; Batalla, Alain; Balosso, Jacques; Tessonnier, Thomas

    2018-03-01

    Proton therapy is a radiotherapy, based on the use of protons, charged subatomic particles that stop at a given depth depending on their initial energy (pristine Bragg peak), avoiding any output beam, unlike the photons used in most of the other modalities of radiotherapy. Proton therapy has been used for 60 years, but has only become ubiquitous in the last decade because of recent major advances in particle accelerator technology. This article reviews the history of clinical implementation of protons, the nature of the technological advances that now allows its expansion at a lower cost. It also addresses the technical and physical specificities of proton therapy and the clinical situations for which proton therapy may be relevant but requires evidence. Different proton therapy techniques are possible. These are explained in terms of their clinical potential by explaining the current terminology (such as cyclotrons, synchrotrons or synchrocyclotrons, using superconducting magnets, fixed line or arm rotary with passive diffusion delivery or active by scanning) in basic words. The requirements associated with proton therapy are increased due to the precision of the depth dose deposit. The learning curve of proton therapy requires that clinical indications be prioritized according to their associated uncertainties (such as range uncertainties and movement in lung tumors). Many clinical indications potentially fall under proton therapy ultimately. Clinical strategies are explained in a paralleled manuscript. Copyright © 2018 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  15. Proton permeation of lipid bilayers.

    Science.gov (United States)

    Deamer, D W

    1987-10-01

    Proton permeation of the lipid bilayer barrier has two unique features. First, permeability coefficients measured at neutral pH ranges are six to seven orders of magnitude greater than expected from knowledge of other monovalent cations. Second, proton conductance across planar lipid bilayers varies at most by a factor of 10 when pH is varied from near 1 to near 11. Two mechanisms have been proposed to account for this anomalous behavior: proton conductance related to contaminants of lipid bilayers, and proton translocation along transient hydrogen-bonded chains (tHBC) of associated water molecules in the membrane. The weight of evidence suggests that trace contaminants may contribute to proton conductance across planar lipid membranes at certain pH ranges, but cannot account for the anomalous proton flux in liposome systems. Two new results will be reported here which were designed to test the tHBC model. These include measurements of relative proton/potassium permeability in the gramicidin channel, and plots of proton flux against the magnitude of pH gradients. (1) The relative permeabilities of protons and potassium through the gramicidin channel, which contains a single strand of hydrogen-bonded water molecules, were found to differ by at least four orders of magnitude when measured at neutral pH ranges. This result demonstrates that a hydrogen-bonded chain of water molecules can provide substantial discrimination between protons and other cations. It was also possible to calculate that if approximately 7% of bilayer water was present in a transient configuration similar to that of the gramicidin channel, it could account for the measured proton flux. (2) The plot of proton conductance against pH gradient across liposome membranes was superlinear, a result that is consistent with one of three alternative tHBC models for proton conductance described by Nagle elsewhere in this volume.

  16. MUSE: Measuring the proton radius with muon-proton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bernauer, Jan Christopher [Massachusetts Institute of Technology, Cambridge (United States)

    2014-07-01

    The proton radius has been measured so far using electron-proton scattering, electronic Hydrogen spectroscopy and muonic Hydrogen spectroscopy, the latter producing a much more accurate, but seven sigma different, result, leading to the now famous proton radius puzzle. The MUSE collaboration aims to complete the set of measurements by using muon scattering to determine the proton radius and to shed light on possible explanations of the discrepancy. The talk gives an overview of the experiment motivation and design and a status report on the progress.

  17. Vibrational spectroscopy on protons and deuterons in proton conducting perovskites

    DEFF Research Database (Denmark)

    Glerup, M.; Poulsen, F.W.; Berg, R.W.

    2002-01-01

    A short review of IR-spectroscopy on protons in perovskite structure oxides is given. The nature of possible proton sites, libration and combination tones and degree of hydrogen bonding is emphasised. Three new spectroscopic experiments and/or interpretations are presented. An IR-microscopy exper......A short review of IR-spectroscopy on protons in perovskite structure oxides is given. The nature of possible proton sites, libration and combination tones and degree of hydrogen bonding is emphasised. Three new spectroscopic experiments and/or interpretations are presented. An IR...

  18. Observations of the Earth's polar cleft at large radial distances with the Hawkeye 1 magnetometer

    International Nuclear Information System (INIS)

    Farrell, W.M.; Van Allen, J.A.

    1990-01-01

    Based on 364-spacecraft passes through the dayside region, the position of the polar cleft at large redial distances was determined with the magnetometer flown on Hawkeye 1. This data set represents one of the largest to investigate the high-latitude region at large radial distances, making it ideal for the study of the cusp and cleft region. Identification of the cleft depended on noting strong negative deviations of the magnetic field strength in the region from that of the dipole field. In solar magnetic coordinates, cleft observations were found between 40 degree and 70 degree latitude and ±75 degree longitude, while in geocentric magnetospheric coordinates, these observations were found between 20 degree and 75 degree latitude and ± 75 degree longitude. The extreme longitudinal extent of 150 degree is larger than those reported in some previous studies. Large magnetic depressions associated with the cleft extend out to 12 R E . Beyond this point, low model dipole field strengths make the determination of the cleft based on magnetic depressions unreliable. The cleft occurrences fall within an oval in magnetic latitude and longitude, but this oval is of a statistical nature and cannot be interpreted as the shape of the region at a given moment. As reported in other studies, the cleft was observed to shift to lower latitudes as compared to its quiet time geometry during periods when Kp was large and when the interplanetary magnetic field (IMF) pointed in a southerly direction. A southerly shift was also observed when th solar wind bulk flow speed, V sw , was large (>450 km/s), and the region might have enlarged when solar wind pressure, P sw , was large. The variation of the cleft latitude with V sw and P sw has not been thoroughly examined in previous studies

  19. An absolute nuclear magnetic resonance magnetometer; Magnetometre absolu a resonance magnetique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Salvi, A [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1961-10-15

    After an introduction in which the various work undertaken since the discovery of nuclear magnetic resonance is rapidly reviewed, the author describes briefly In the first chapter three types of NMR magnetometers, giving the advantages and disadvantages of each of them and deducing from this the design of the apparatus having the greatest number of qualities Chapter II is devoted to the crossed coil nuclear oscillator which operates continuously over a wide range (800 gamma). To avoid an error due to a carrying over the frequency, the measurement is carried out using bands of 1000 {gamma}. Chapter III deals with frequency measurements. The author describes an original arrangement which makes possible the frequency-field conversion with an accuracy of {+-} 5 x 10{sup -6}, and the differential measurement between two nuclear oscillators. The report finishes with a conclusion and a few recordings. (author) [French] Apres une introduction rappelant les divers travaux effectues en resonance magnetique nucleaire depuis sa mise en evidence, l'auteur decrit sommairement dans le premier chapitre trois types de magnetometre a R.M.N. enumerant les avantages et les inconvenients de chacun a partir desquels il projet, l'appareillage reunissant le maximum de qualites. Le chapitre II est consacre a l'oscillateur nucleaire a bobines croisees permettant un fonctionnement continu dons une large plage (800 gamma). Pour eviter une erreur due a l'entrainement de frequence, la mesure s'effectue par bandes de 1000 {gamma} chacune. Le chapitre III traite la mesure de frequence. L'auteur expose un montage original permettant la traduction frequence-champ avec une precision egale a {+-} 5.10{sup -6}, et la mesure differentielle entre deux oscillateurs nucleaires. Une conclusion et quelques enregistrements terminent ce travail. (auteur)

  20. Magnetic dichroism in photoemission: a new element-specific magnetometer with atomic-layer resolution

    International Nuclear Information System (INIS)

    Starke, K.; Arenholz, E.; Kaindl, G.

    1998-01-01

    Full text: Magnetic coupling in layered metallic structures has become a key issue in thin-film magnetism since the observation of oscillatory exchange coupling across non-ferromagnetic spacer layers. Although this phenomenon was discovered in rare earths (RE) superlattices, mostly transition-metal systems have been studied and are now applied in data-storage industry. An understanding of the coupling mechanisms has been reached after a fabrication of high-quality interfaces became possible. It allowed, in particular, the experimental finding of induced ferromagnetic order in 'nonmagnetic' atomic layers near an interface, using element-specific probes such as magnetic circular dichroism in x-ray absorption. - In layered RE systems, by contrast, the well known intermiscibility has prevented a preparation of atomically sharp interfaces, and all RE superlattices studied so far showed interdiffusion zones of several atomic layers. In the present overview, we report the first fabrication of atomically flat heteromagnetic RE interfaces, their structural characterization and their magnetic analysis using magnetic dichroism in photoemission (MDPE). This new tool gives access to the magnetization of individual atomic layers near interfaces in favourite cases. Merits of MDPE as a magnetometer are demonstrated at the example of Eu/Gd(0001), where chemical shifts of core-level photoemission lines allow to spectroscopically separate up to four different atomic layers. The high surface sensitivity of MDPE, together with the well known dependence of the core-level binding energies on the coordination number of the photo emitting atom, opens the door to future site-specific studies of magnetism in sub-monolayer systems such as 'nanowires'

  1. Measurement of small-angle antiproton-proton and proton-proton elastic scattering at the CERN intersecting storage rings

    NARCIS (Netherlands)

    Amos, N.; Block, M.M.; Bobbink, G.J.; Botje, M.A.J.; Favart, D.; Leroy, C.; Linde, F.; Lipnik, P.; Matheys, J-P.; Miller, D.

    1985-01-01

    Antiproton-proton and proton-proton small-angle elastic scattering was measured for centre-of-mass energies at the CERN Intersectung Storage Rings. In addition, proton-proton elastic scattering was measured at . Using the optical theorem, total cross sections are obtained with an accuracy of about

  2. Proton and carbon ion therapy

    CERN Document Server

    Lomax, Tony

    2013-01-01

    Proton and Carbon Ion Therapy is an up-to-date guide to using proton and carbon ion therapy in modern cancer treatment. The book covers the physics and radiobiology basics of proton and ion beams, dosimetry methods and radiation measurements, and treatment delivery systems. It gives practical guidance on patient setup, target localization, and treatment planning for clinical proton and carbon ion therapy. The text also offers detailed reports on the treatment of pediatric cancers, lymphomas, and various other cancers. After an overview, the book focuses on the fundamental aspects of proton and carbon ion therapy equipment, including accelerators, gantries, and delivery systems. It then discusses dosimetry, biology, imaging, and treatment planning basics and provides clinical guidelines on the use of proton and carbon ion therapy for the treatment of specific cancers. Suitable for anyone involved with medical physics and radiation therapy, this book offers a balanced and critical assessment of state-of-the-art...

  3. The PIREX proton irradiation facility

    International Nuclear Information System (INIS)

    Victoria, M.

    1995-01-01

    The proton Irradiation Experiment (PIREX) is a materials irradiation facility installed in a beam line of the 590 MeV proton accelerator at the Paul Scherrer Institute. Its main purpose is the testing of candidate materials for fusion reactor components. Protons of this energy produce simultaneously displacement damage and spallation products, amongst them helium and can therefore simulate any possible synergistic effects of damage and helium, that would be produced by the fusion neutrons

  4. The PIREX proton irradiation facility

    Energy Technology Data Exchange (ETDEWEB)

    Victoria, M. [Association EURATOM, Villigen (Switzerland)

    1995-10-01

    The proton Irradiation Experiment (PIREX) is a materials irradiation facility installed in a beam line of the 590 MeV proton accelerator at the Paul Scherrer Institute. Its main purpose is the testing of candidate materials for fusion reactor components. Protons of this energy produce simultaneously displacement damage and spallation products, amongst them helium and can therefore simulate any possible synergistic effects of damage and helium, that would be produced by the fusion neutrons.

  5. Search for proton decay: introduction

    International Nuclear Information System (INIS)

    Goldhaber, M.

    1984-01-01

    In interpreting contained events observed in various proton decay detectors one can sometimes postulate, though usually not unambiguously, a potential decay mode of the proton, called a candidate. It is called a candidate, because for any individual event it is not possible to exclude the possibility that it is instead due to cosmic ray background, chiefly atmospheric neutrinos. Some consistency checks are proposed which could help establish proton decay, if it does occur in the presently accessible lifetime window

  6. Sea Quarks in the Proton

    Directory of Open Access Journals (Sweden)

    Reimer Paul E

    2016-01-01

    Full Text Available The proton is a composite particle in which the binding force is responsible for the majority of its mass. To understand this structure, the distributions and origins of the quark-antiquark pairs produced by the strong force must be measured. The SeaQuest collaboration is using the Drell-Yan process to elucidate antiquark distributions in the proton and to study their modification when the proton is held within a nucleus.

  7. Proton irradiation and endometriosis

    International Nuclear Information System (INIS)

    Wood, D.H.; Yochmowitz, M.G.; Salmon, Y.L.; Eason, R.L.; Boster, R.A.

    1983-01-01

    Female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was 7 years after exposure. The doses and energies of the radiation received were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event, leading to the conclusion that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crewmembers

  8. Proton nuclear scattering radiography

    International Nuclear Information System (INIS)

    Duchazeaubeneix, J.C.; Faivre, J.C.; Garreta, D.

    1982-10-01

    Nuclear scattering of protons allows to radiograph objects with specific properties: direct 3- dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore, it is a well adapted method to gating techniques allowing the radiography of fast periodic moving systems. Results obtained on different objects (light and heavy materials) are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiography faster and to get a practical method are discussed

  9. Proton nuclear scattering radiography

    International Nuclear Information System (INIS)

    Saudinos, J.

    1982-04-01

    Nuclear scattering of protons allows to radiograph objects with specific properties: 3-dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore the nuclear scattering radiography (NSR) is a well adapted method to gating techniques allowing the radiography of fast periodic moving objects. Results obtained on phantoms, formalin fixed head and moving object are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiograph faster and to get a practical method are discussed

  10. Proton relativistic model

    International Nuclear Information System (INIS)

    Araujo, Wilson Roberto Barbosa de

    1995-01-01

    In this dissertation, we present a model for the nucleon, which is composed by three relativistic quarks interacting through a contract force. The nucleon wave-function was obtained from the Faddeev equation in the null-plane. The covariance of the model under kinematical null-plane boots is discussed. The electric proton form-factor, calculated from the Faddeev wave-function, was in agreement with the data for low-momentum transfers and described qualitatively the asymptotic region for momentum transfers around 2 GeV. (author)

  11. Proton-proton bremsstrahlung towards the elastic limit

    Science.gov (United States)

    Mahjour-Shafiei, M.; Amir-Ahmadi, H. R.; Bacelar, J. C. S.; Castelijns, R.; Ermisch, K.; van Garderen, E.; Gašparić, I.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Kiš, M.; Löhner, H.

    2005-05-01

    In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed.

  12. Proton-proton bremsstrahlung towards the elastic limit

    International Nuclear Information System (INIS)

    Mahjour-Shafiei, M.; Amir-Ahmadi, H.R.; Bacelar, J.C.S.; Castelijns, R.; Ermisch, K.; Garderen, E. van; Harakeh, M.N.; Kalantar-Nayestanaki, N.; Kis, M.; Loehner, H.; Gasparic, I.

    2005-01-01

    In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed

  13. The FAIR proton linac

    International Nuclear Information System (INIS)

    Kester, O.

    2015-01-01

    FAIR - the Facility for Antiproton and Ion Research in Europe - constructed at GSI in Darmstadt comprises an international centre of heavy ion accelerators that will drive heavy ion and antimatter research. FAIR will provide worldwide unique accelerator and experimental facilities, allowing a large variety of fore-front research in physics and applied science. FAIR will deliver antiproton and ion beams of unprecedented intensities and qualities. The main part of the FAIR facility is a sophisticated accelerator system, which delivers beams to different experiments of the FAIR experimental collaborations - APPA, NuSTAR, CBM and PANDA - in parallel. Modern H-type cavities offer highest shunt impedances of resonant structures of heavy ion linacs at low beam energies < 20 MeV/u and enable the acceleration of intense proton and ion beams. One example is the interdigital H-type structure. The crossed-bar H-cavities extend these properties to high energies even beyond 100 MeV/u. Compared to conventional Alvarez cavities, these crossed-bar (CH) cavities feature much higher shunt impedance at low energies. The design of the proton linac is based on those cavities

  14. Proton minibeam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Girst, Stefanie

    2016-03-08

    The risk of developing adverse side effects in the normal tissue after radiotherapy is often limiting for the dose that can be applied to the tumor. Proton minibeam radiotherapy, a spatially fractionated radiotherapy method using sub-millimeter proton beams, similar to grid therapy or microbeam radiation radiotherapy (MRT) using X-rays, has recently been invented at the ion microprobe SNAKE in Munich. The aim of this new concept is to minimize normal tissue injuries in the entrance channel and especially in the skin by irradiating only a small percentage of the cells in the total irradiation field, while maintaining tumor control via a homogeneous dose in the tumor, just like in conventional broad beam radiotherapy. This can be achieved by optimizing minibeam sizes and distances according to the prevailing tumor size and depth such that after widening of the minibeams due to proton interactions in the tissue, the overlapping minibeams produce a homogeneous dose distribution throughout the tumor. The aim of this work was to elucidate the prospects of minibeam radiation therapy compared to conventional homogeneous broad beam radiotherapy in theory and in experimental studies at the ion microprobe SNAKE. Treatment plans for model tumors of different sizes and depths were created using the planning software LAPCERR, to elaborate suitable minibeam sizes and distances for the individual tumors. Radiotherapy-relevant inter-beam distances required to obtain a homogeneous dose in the target volume were found to be in the millimeter range. First experiments using proton minibeams of only 10 μm and 50 μm size (termed microchannels in the corresponding publication Zlobinskaya et al. 2013) and therapy-conform larger dimensions of 100 μm and 180 μm were performed in the artificial human in-vitro skin model EpiDermFT trademark (MatTek). The corresponding inter-beam distances were 500 μm, 1mm and 1.8 mm, respectively, leading to irradiation of only a few percent of the cells

  15. Berkeley Proton Linear Accelerator

    Science.gov (United States)

    Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

    1953-10-13

    A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

  16. Coupled-core fluxgate magnetometer: Novel configuration scheme and the effects of a noise-contaminated external signal

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, Antonio [San Diego State University, Nonlinear Dynamical Systems Group, Department of Mathematics and Statistics, San Diego, CA 92182-7720 (United States)]. E-mail: palacios@euler.sdsu.edu; Aven, John [San Diego State University, Nonlinear Dynamical Systems Group, Department of Mathematics and Statistics, San Diego, CA 92182-7720 (United States); In, Visarath [Space and Naval Warfare Systems Center San Diego, Code 2363, 53560 Hull St, San Diego, CA 92152-5001 (United States)]. E-mail: visarath@spawar.navy.mil; Longhini, Patrick [Space and Naval Warfare Systems Center San Diego, Code 2363, 53560 Hull St, San Diego, CA 92152-5001 (United States); Kho, Andy [Space and Naval Warfare Systems Center San Diego, Code 2363, 53560 Hull St, San Diego, CA 92152-5001 (United States); Neff, Joseph D. [Space and Naval Warfare Systems Center San Diego, Code 2363, 53560 Hull St, San Diego, CA 92152-5001 (United States); Bulsara, Adi [Space and Naval Warfare Systems Center San Diego, Code 2363, 53560 Hull St, San Diego, CA 92152-5001 (United States)]. E-mail: bulsara@spawar.navy.mil

    2007-07-16

    Recent theoretical and experimental work has shown that unidirectional coupling can induce oscillations in overdamped and undriven nonlinear dynamical systems that are non-oscillatory when uncoupled; in turn, this has been shown to lead to new mechanisms for weak (compared to the energy barrier height) signal detection and amplification. The potential applications include fluxgate magnetometers, electric field sensors, and arrays of Superconducting Quantum Interference Device (SQUID) rings. In the particular case of the fluxgate magnetometer, we have developed a ''coupled-core fluxgate magnetometer'' (CCFM); this device has been realized in the laboratory and its dynamics used to quantify many properties that are generic to this class of systems and coupling. The CCFM operation is underpinned by the emergent oscillatory behavior in a unidirectionally coupled ring of wound ferromagnetic cores, each of which can be treated as an overdamped bistable dynamic system when uncoupled. In particular, one can determine the regimes of existence and stability of the (coupling-induced) oscillations, and the scaling behavior of the oscillation frequency. More recently, we studied the effects of a (Gaussian) magnetic noise floor on a CCFM system realized with N=3 coupled ferromagnetic cores. In this Letter, we first introduce a variation on the basic CCFM configuration that affords a path to enhanced device sensitivity, particularly for N>=3 coupled elements. We then analyze the response of the basic CCFM configuration as well as the new setup to a dc target signal that has a small noisy component (or ''contamination'')

  17. Free induction decay MR signal measurements toward ultra-low field MRI with an optically pumped atomic magnetometer.

    Science.gov (United States)

    Oida, Takenori; Kobayashi, Tetsuo

    2013-01-01

    Ultra-low field magnetic resonance imaging (ULF-MRI) has attracted attention because of its low running costs and minimum patient exposure. An optically pumped atomic magnetometer (OPAM) is a magnetic sensor with high sensitivity in the low frequency range, which does not require a cryogenic cooling system. In an effort to develop a ULF-MRI, we attempted to measure the free induction decay MR signals with an OPAM. We successfully detected the MR signals by combining an OPAM and a flux transformer, demonstrating the feasibility of the proposed system.

  18. Optimizing the sensing performance of a single-rod fluxgate magnetometer using thin magnetic wires

    International Nuclear Information System (INIS)

    Can, Hava; Tanrıseven, Sercan; Birlikseven, Cengiz; Sözeri, Hüseyin; Topal, Uğur; Svec, Peter Jr; Svec, Peter Sr; Bydzovsky, Jan

    2015-01-01

    This paper presents the optimal conditions for the design of a single-rod fluxgate magnetometer using Co-based amorphous magnetic wires with reduced geometrical dimensions of 100 μm in diameter. In order to enhance the performance of the current sensor (i.e. the noise level, the sensitivity, the dynamical range, the scaling factor, etc), the core materials were subjected to annealing at different annealing temperatures in a longitudinal magnetic field ranging from 0 to 0.5 T. The B–H measurements have shown that the heat treatments significantly change the magnetic parameters of the cores (the saturation field, the initial and apparent permeabilities). For instance, the initial permeability μ i attains values of between 3500 and 4700 depending on the treatment conditions. These magnetic parameters were subsequently correlated with the sensor performance by using the principles of the fluxgate physics. Consequently, the enhanced fluxgate effect with improved sensing characteristics has been obtained by annealing the wire core at 250 °C (B  =  0 T). It is shown that this magnetic wire with a sensing area of 0.00785 mm 2 is suitable as a sensor core for the nondestructive testing of metallic objects and the surfaces of magnetic cards. The sensor signal shows perfect linear dependence to dc or low frequency fields up to ∼1 Oe. The fitting parameters R 2 of 0.9998 could be achieved in a dc field interval of  −1.0 Oe and 1.0 Oe (when R 2   =1.0, all points lie exactly on the curve with no scatter). Such linearity has not been seen in such a large dynamical range until now in the rod-type single-core fluxgates. It is also shown that there is no hysteresis on the V 2f –H dc graphs (the V 2f is the sensor signal) even after applying fields as high as 100 Oe. Besides, the cross-field effect is almost zero due to the geometry of the long-thin wire. (paper)

  19. Optimizing the sensing performance of a single-rod fluxgate magnetometer using thin magnetic wires

    Science.gov (United States)

    Can, Hava; Svec, Peter, Jr.; Tanrıseven, Sercan; Bydzovsky, Jan; Birlikseven, Cengiz; Sözeri, Hüseyin; Svec, Peter, Sr.; Topal, Uğur

    2015-11-01

    This paper presents the optimal conditions for the design of a single-rod fluxgate magnetometer using Co-based amorphous magnetic wires with reduced geometrical dimensions of 100 μm in diameter. In order to enhance the performance of the current sensor (i.e. the noise level, the sensitivity, the dynamical range, the scaling factor, etc), the core materials were subjected to annealing at different annealing temperatures in a longitudinal magnetic field ranging from 0 to 0.5 T. The B-H measurements have shown that the heat treatments significantly change the magnetic parameters of the cores (the saturation field, the initial and apparent permeabilities). For instance, the initial permeability μ i attains values of between 3500 and 4700 depending on the treatment conditions. These magnetic parameters were subsequently correlated with the sensor performance by using the principles of the fluxgate physics. Consequently, the enhanced fluxgate effect with improved sensing characteristics has been obtained by annealing the wire core at 250 °C (B  =  0 T). It is shown that this magnetic wire with a sensing area of 0.00785 mm2 is suitable as a sensor core for the nondestructive testing of metallic objects and the surfaces of magnetic cards. The sensor signal shows perfect linear dependence to dc or low frequency fields up to ~1 Oe. The fitting parameters R 2 of 0.9998 could be achieved in a dc field interval of  -1.0 Oe and 1.0 Oe (when R 2  =1.0, all points lie exactly on the curve with no scatter). Such linearity has not been seen in such a large dynamical range until now in the rod-type single-core fluxgates. It is also shown that there is no hysteresis on the V 2f -H dc graphs (the V 2f is the sensor signal) even after applying fields as high as 100 Oe. Besides, the cross-field effect is almost zero due to the geometry of the long-thin wire.

  20. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...