Science.gov

Sample records for active radiation measurements

  1. Photocatalytic Active Radiation Measurements and Use

    NASA Technical Reports Server (NTRS)

    Davis, Bruce A.; Underwood, Lauren W.

    2011-01-01

    Photocatalytic materials are being used to purify air, to kill microbes, and to keep surfaces clean. A wide variety of materials are being developed, many of which have different abilities to absorb various wavelengths of light. Material variability, combined with both spectral illumination intensity and spectral distribution variability, will produce a wide range of performance results. The proposed technology estimates photocatalytic active radiation (PcAR), a unit of radiation that normalizes the amount of light based on its spectral distribution and on the ability of the material to absorb that radiation. Photocatalytic reactions depend upon the number of electron-hole pairs generated at the photocatalytic surface. The number of electron-hole pairs produced depends on the number of photons per unit area per second striking the surface that can be absorbed and whose energy exceeds the bandgap of the photocatalytic material. A convenient parameter to describe the number of useful photons is the number of moles of photons striking the surface per unit area per second. The unit of micro-einsteins (or micromoles) of photons per m2 per sec is commonly used for photochemical and photoelectric-like phenomena. This type of parameter is used in photochemistry, such as in the conversion of light energy for photosynthesis. Photosynthetic response correlates with the number of photons rather than by energy because, in this photochemical process, each molecule is activated by the absorption of one photon. In photosynthesis, the number of photons absorbed in the 400 700 nm spectral range is estimated and is referred to as photosynthetic active radiation (PAR). PAR is defined in terms of the photosynthetic photon flux density measured in micro-einsteins of photons per m2 per sec. PcAR is an equivalent, similarly modeled parameter that has been defined for the photocatalytic processes. Two methods to measure the PcAR level are being proposed. In the first method, a calibrated

  2. A New Quantum Sensor for Measuring Photosynthetically Active Radiation

    NASA Astrophysics Data System (ADS)

    Johnson, D.; Thomas, T.; Heinicke, D.; Peterson, R.; Morgan, P.; McDermitt, D. K.; Burba, G. G.

    2015-12-01

    A quantum sensor measures photosynthetically active radiation (PAR, in μmol of photons m-2 s-1) in the 400 nm to 700 nm waveband. Plants utilize this radiation to drive photosynthesis, though individual plant responses to incident radiation may vary within this range. The new quantum sensor (model LI-190R, LI-COR Biosciences, Lincoln, NE), with an optical filter and silicon photodiode detector housed in a cosine-corrected head, is designed to provide a better response to incident radiation across the 400-700 nm range. The new design is expected to significantly improve spectral response due to uniformity across the PAR waveband, but particularly in the wavebands from 520 nm to 600 nm and 665 nm to 680 nm, and sharp cutoffs in the regions below and above the PAR waveband. Special care was taken to make sure that PAR sensor would not substantially respond to incident radiation above the 700 nm threshold because this can lead to errors when performing measurements in environments with a large proportion of near-infrared radiation, such as canopy understory. The physical housing of the sensor is designed to be weather-resistant, to effectively shed precipitation, provide protection at high temperature and high humidity conditions, and has a cosine-corrected response to 82° zenith angle. The latter is particularly important when measuring incident radiation at low elevation angles, diffuse light, or low light conditions. This presentation describes the principles of the new design, and shows the performance results from field experiments and laboratory tests.

  3. PARduino: A Simple Device Measuring and Logging Photosynthetically Active Radiation

    NASA Astrophysics Data System (ADS)

    Barnard, H. R.; Findley, M. C.

    2013-12-01

    Photosynthetically Active Radiation (PAR, 400 to 700 nm) is one of the primary controls of forest carbon and water relations. In complex terrain, PAR has high spatial-variability. Given the high cost of commercial datalogging equipment, spatially-distributed measurements of PAR have been typically modeled using geographic coordinates and terrain indices. Here, we present a design for a low cost, field-deployable device for measuring and logging PAR built around an Arduino microcontroller (we named it PARduino). PARduino provides for widely distributed sensor arrays and tests the feasibility of using hobbyist-grade electronics for collecting scientific data. PARduino components include a LiCor quantum sensor, EME Systems signal converter/amplifier, and Sparkfun's Arduino Pro Mini microcontroller. Additional components include a real time clock, a microSD flash memory card, and a custom printed circuit board (PCB). We selected the components with an eye towards ease of assembly. Everything can be connected to the PCB using through-hole soldering techniques. Since the device will be deployed in remote research plots that lack easy access to line power, battery life was also a consideration in the design. Extended deployment is possible because PARduino's software keeps it in a low-power sleep mode until ready to make a measurement. PARduino will be open-source hardware for use and improvement by others.

  4. Radiation Measurements Performed with Active Detectors Relevant for Human Space Exploration

    PubMed Central

    Narici, Livio; Berger, Thomas; Matthiä, Daniel; Reitz, Günther

    2015-01-01

    A reliable radiation risk assessment in space is a mandatory step for the development of countermeasures and long-duration mission planning in human spaceflight. Research in radiobiology provides information about possible risks linked to radiation. In addition, for a meaningful risk evaluation, the radiation exposure has to be assessed to a sufficient level of accuracy. Consequently, both the radiation models predicting the risks and the measurements used to validate such models must have an equivalent precision. Corresponding measurements can be performed both with passive and active devices. The former is easier to handle, cheaper, lighter, and smaller but they measure neither the time dependence of the radiation environment nor some of the details useful for a comprehensive radiation risk assessment. Active detectors provide most of these details and have been extensively used in the International Space Station. To easily access such an amount of data, a single point access is becoming essential. This review presents an ongoing work on the development of a tool that allows obtaining information about all relevant measurements performed with active detectors providing reliable inputs for radiation model validation. PMID:26697408

  5. Radiation Measurements Performed with Active Detectors Relevant for Human Space Exploration.

    PubMed

    Narici, Livio; Berger, Thomas; Matthiä, Daniel; Reitz, Günther

    2015-01-01

    A reliable radiation risk assessment in space is a mandatory step for the development of countermeasures and long-duration mission planning in human spaceflight. Research in radiobiology provides information about possible risks linked to radiation. In addition, for a meaningful risk evaluation, the radiation exposure has to be assessed to a sufficient level of accuracy. Consequently, both the radiation models predicting the risks and the measurements used to validate such models must have an equivalent precision. Corresponding measurements can be performed both with passive and active devices. The former is easier to handle, cheaper, lighter, and smaller but they measure neither the time dependence of the radiation environment nor some of the details useful for a comprehensive radiation risk assessment. Active detectors provide most of these details and have been extensively used in the International Space Station. To easily access such an amount of data, a single point access is becoming essential. This review presents an ongoing work on the development of a tool that allows obtaining information about all relevant measurements performed with active detectors providing reliable inputs for radiation model validation.

  6. Radiation Measurements Performed with Active Detectors Relevant for Human Space Exploration.

    PubMed

    Narici, Livio; Berger, Thomas; Matthiä, Daniel; Reitz, Günther

    2015-01-01

    A reliable radiation risk assessment in space is a mandatory step for the development of countermeasures and long-duration mission planning in human spaceflight. Research in radiobiology provides information about possible risks linked to radiation. In addition, for a meaningful risk evaluation, the radiation exposure has to be assessed to a sufficient level of accuracy. Consequently, both the radiation models predicting the risks and the measurements used to validate such models must have an equivalent precision. Corresponding measurements can be performed both with passive and active devices. The former is easier to handle, cheaper, lighter, and smaller but they measure neither the time dependence of the radiation environment nor some of the details useful for a comprehensive radiation risk assessment. Active detectors provide most of these details and have been extensively used in the International Space Station. To easily access such an amount of data, a single point access is becoming essential. This review presents an ongoing work on the development of a tool that allows obtaining information about all relevant measurements performed with active detectors providing reliable inputs for radiation model validation. PMID:26697408

  7. Using a simple apparatus to measure direct and diffuse photosynthetically active radiation at remote locations.

    PubMed

    Cruse, Michael J; Kucharik, Christopher J; Norman, John M

    2015-01-01

    Plant canopy interception of photosynthetically active radiation (PAR) drives carbon dioxide (CO2), water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM) Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal) of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the potential to support

  8. Using a Simple Apparatus to Measure Direct and Diffuse Photosynthetically Active Radiation at Remote Locations

    PubMed Central

    Cruse, Michael J.; Kucharik, Christopher J.; Norman, John M.

    2015-01-01

    Plant canopy interception of photosynthetically active radiation (PAR) drives carbon dioxide (CO2), water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM) Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal) of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the potential to support

  9. Measurement of energetic radiation caused by thunderstorm activities by a sounding balloon and ground observation

    NASA Astrophysics Data System (ADS)

    Torii, T.

    2015-12-01

    Energetic radiation caused by thunderstorm activity is observed at various places, such as the ground, high mountain areas, and artificial satellites. In order to investigate the radiation source and its energy distribution, we measured energetic radiation by a sounding balloon, and the ground observation. On the measurement inside/above the thundercloud, we conducted a sounding observation using a radiosonde mounted two GM tubes (for gamma-rays, and for beta/gamma-rays), in addition to meteorological instruments. The balloon passed through a region of strong echoes in a thundercloud shown by radar image, at which time an increase in counting rate of the GM tube about 2 orders of magnitude occurred at the altitude from 5 km to 7.5 km. Furthermore, the counting rate of two GM tubes indicated the tendency different depending on movement of a balloon. This result suggests that the ratio for the gamma-rays (energetic photons) of the beta-rays (energetic electrons) varies according to the place in the thundercloud. Furthermore, we carried out a ground observation of the energetic gamma rays during winter thunderstorm at a coastal area facing the Sea of Japan. Two types of the energetic radiation have been observed at this time. We report the outline of these measurements and analysis in the session of the AGU meeting.

  10. Measuring the activity of a {sup 51}Cr neutrino source based on the gamma-radiation spectrum

    SciTech Connect

    Gorbachev, V. V. Gavrin, V. N.; Ibragimova, T. V.; Kalikhov, A. V.; Malyshkin, Yu. M.; Shikhin, A. A.

    2015-12-15

    A technique for the measurement of activities of intense β sources by measuring the continuous gamma-radiation (internal bremsstrahlung) spectra is developed. A method for reconstructing the spectrum recorded by a germanium semiconductor detector is described. A method for the absolute measurement of the internal bremsstrahlung spectrum of {sup 51}Cr is presented.

  11. Earth Radiation Measurement Science

    NASA Technical Reports Server (NTRS)

    Smith, G. Louis

    2000-01-01

    This document is the final report for NASA Grant NAG1-1959, 'Earth Radiation Measurement Science'. The purpose of this grant was to perform research in this area for the needs of the Clouds and Earth Radiant Energy System (CERES) project and for the Earth Radiation Budget Experiment (ERBE), which are bing conducted by the Radiation and Aerosols Branch of the Atmospheric Sciences Division of Langley Research Center. Earth Radiation Measurement Science investigates the processes by which measurements are converted into data products. Under this grant, research was to be conducted for five tasks: (1) Point Response Function Measurements; (2) Temporal Sampling of Outgoing Longwave Radiation; (3) Spatial Averaging of Radiation Budget Data; (4) CERES Data Validation and Applications; and (5) ScaRaB Data Validation and Application.

  12. Apparatus having reduced background for measuring radiation activity in aerosol particles

    DOEpatents

    Rodgers, John C.; McFarland, Andrew R.; Oritz, Carlos A.; Marlow, William H.

    1992-01-01

    Apparatus having reduced background for measuring radiation activity in aerosol particles. A continuous air monitoring sampler is described for use in detecting the presence of alpha-emitting aerosol particles. An inlet fractionating screen has been demonstrated to remove about 95% of freshly formed radon progeny from the aerosol sample, and approximately 33% of partially aged progeny. Addition of an electrical condenser and a modified dichotomous virtual impactor are expected to produce considerable improvement in these numbers, the goal being to enrich the transuranic (TRU) fraction of the aerosols. This offers the possibility of improving the signal-to-noise ratio for the detected alpha-particle energy spectrum in the region of interest for detecting TRU materials associated with aerosols, thereby enhancing the performance of background-compensation algorithms for improving the quality of alarm signals intended to warn personnel of potentially harmful quantities of TRU materials in the ambient air.

  13. Online educative activities for solar ultraviolet radiation based on measurements of cloud amount and solar exposures.

    PubMed

    Parisi, A V; Downs, N; Turner, J; Amar, A

    2016-09-01

    A set of online activities for children and the community that are based on an integrated real-time solar UV and cloud measurement system are described. These activities use the functionality of the internet to provide an educative tool for school children and the public on the influence of cloud and the angle of the sun above the horizon on the global erythemal UV or sunburning UV, the diffuse erythemal UV, the global UVA (320-400nm) and the vitamin D effective UV. Additionally, the units of UV exposure and UV irradiance are investigated, along with the meaning and calculation of the UV index (UVI). This research will help ensure that children and the general public are better informed about sun safety by improving their personal understanding of the daily and the atmospheric factors that influence solar UV radiation and the solar UV exposures of the various wavebands in the natural environment. The activities may correct common misconceptions of children and the public about UV irradiances and exposure, utilising the widespread reach of the internet to increase the public's awareness of the factors influencing UV irradiances and exposures in order to provide clear information for minimizing UV exposure, while maintaining healthy, outdoor lifestyles.

  14. Online educative activities for solar ultraviolet radiation based on measurements of cloud amount and solar exposures.

    PubMed

    Parisi, A V; Downs, N; Turner, J; Amar, A

    2016-09-01

    A set of online activities for children and the community that are based on an integrated real-time solar UV and cloud measurement system are described. These activities use the functionality of the internet to provide an educative tool for school children and the public on the influence of cloud and the angle of the sun above the horizon on the global erythemal UV or sunburning UV, the diffuse erythemal UV, the global UVA (320-400nm) and the vitamin D effective UV. Additionally, the units of UV exposure and UV irradiance are investigated, along with the meaning and calculation of the UV index (UVI). This research will help ensure that children and the general public are better informed about sun safety by improving their personal understanding of the daily and the atmospheric factors that influence solar UV radiation and the solar UV exposures of the various wavebands in the natural environment. The activities may correct common misconceptions of children and the public about UV irradiances and exposure, utilising the widespread reach of the internet to increase the public's awareness of the factors influencing UV irradiances and exposures in order to provide clear information for minimizing UV exposure, while maintaining healthy, outdoor lifestyles. PMID:27450297

  15. METHOD FOR MEASURING RADIATION

    DOEpatents

    Roesch, W.C.; McCall, R.C.

    1961-11-21

    A method for measuring an unknown integrated quantity of radiation with a condenser ionization chamber is described. The chamber is initially charged to a predetermined voltage by a voltage source. The chamber is then removed from the source and exposed to an unknown quantity of radiation for a period of time. The quantity of radiation to which the chamber was exposed is then measured by detecting the magnitude of the pulse of current necessary to recharge the chamber of its initial value through a suitable impedance. The current pulse is amplified and measured directly by a suitable pulse height analyzing system. (AEC)

  16. Small Active Radiation Monitor

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.

    2004-01-01

    A device, named small active radiation monitor, allows on-orbit evaluations during periods of increased radiation, after extravehicular activities, or at predesignated times for crews on such long-duration space missions as on the International Space Station. It also permits direct evaluation of biological doses, a task now performed using a combination of measurements and potentially inaccurate simulations. Indeed the new monitor can measure a full array of radiation levels, from soft x-rays to hard galactic cosmic-ray particles. With refinement, it will benefit commercial (nuclear power-plant workers, airline pilots, medical technicians, physicians/dentists, and others) and military personnel as well as the astronauts for whom thermoluminescent dosimeters are inadequate. Civilian and military personnel have long since graduated from film badges to thermoluminescent dosimeters. Once used, most dosimeters must be returned to a central facility for processing, a step that can take days or even weeks. While this suffices for radiation workers for whom exposure levels are typically very low and of brief duration, it does not work for astronauts. Even in emergencies and using express mail, the results can often be delayed by as much as 24 hours. Electronic dosimeters, which are the size of electronic oral thermometers, and tattlers, small electronic dosimeters that sound an alarm when the dose/dose rate exceeds preset values, are also used but suffer disadvantages similar to those of thermoluminescent dosimeters. None of these devices fully answers the need of rapid monitoring during the space missions. Instead, radiation is monitored by passive detectors, which are read out after the missions. Unfortunately, these detectors measure only the absorbed dose and not the biologically relevant dose equivalent. The new monitor provides a real-time readout, a time history of radiation exposures (both absorbed dose and biologically relevant dose equivalent), and a count of the

  17. Passive and Active Radiation Measurements Capability at the INL Zero Power Physics Reactor (ZPPR) Facility

    SciTech Connect

    Robert Neibert; John Zabriskie; Collin Knight; James L. Jones

    2010-12-01

    The Zero Power Physics Reactor (ZPPR) facility is a Department of Energy facility located in the Idaho National Laboratory’s (INL) Materials and Fuels Complex. It contains various nuclear and non-nuclear materials that are available to support many radiation measurement assessments. User-selected, single material, nuclear and non-nuclear materials can be readily utilized with ZPPR clamshell containers with almost no criticality concerns. If custom, multi-material configurations are desired, the ZPPR clamshell or an approved aluminum Inspection Object (IO) Box container may be utilized, yet each specific material configuration will require a criticality assessment. As an example of the specialized material configurations possible, the National Nuclear Security Agency’s Office of Nuclear Verification (NNSA/NA 243) has sponsored the assembly of six material configurations. These are shown in the Appendixes and have been designated for semi-permanent storage that can be available to support various radiation measurement applications.

  18. Airborne gamma radiation measurements of soil moisture during FIFE: Activities and results

    NASA Technical Reports Server (NTRS)

    Peck, Eugene L.

    1992-01-01

    Soil moisture measurements were obtained during the summer of 1987 and 1989 near Manhattan, Kansas, using the National Weather Service (NWS) airborne gamma radiation system. A network of 24 flight lines were established over the research area. Airborne surveys were flown daily during two intensive field campaigns. The data collected was sufficient to modify the NWS standard operational method for estimating soil moisture for the Field Experiment (FIFE) flight lines. The average root mean square error of the soil moisture estimates for shorter FIFE flight lines was found to be 2.5 percent, compared with a reported value of 3.9 percent for NWS flight lines. Techniques were developed to compute soil moisture estimates for portions of the flight lines. Results of comparisons of the airborne gamma radiation soil moisture estimates with those obtained using the NASA Pushbroom Microwave Radiation (PBMR) system and hydrological model are presented. The airborne soil moisture measurements, and real averages computed using all remotely sensed and ground data, have been in support of the research of the many FIFE investigators whose overall goal was the upscale integration of models and the application of satellite remote sensing.

  19. Flame Radiation Measurements

    NASA Technical Reports Server (NTRS)

    Claus, R. W.; Humenik, F. M.; Neely, G. M.

    1983-01-01

    Spectral and total flame radiation measurements exhibited: (1) that radiant heat flux increases with vision combustor inlet air pressure; (2) the effect of fuel atomization characteristics on radiant heat flux; and (3) that a reduction in fuel hydrogen content produces a significant increase in radiant heat flux primarily at low combustor pressures.

  20. RADIATION MEASURING DEVICES

    DOEpatents

    Bouricius, G.M.B.; Rusch, G.K.

    1960-03-22

    A radiation-measuring device is described having an a-c output. The apparatus has a high-energy particle source responsive to radiation flux disposed within a housing having a pair of collector plates. A potential gradient between the source and collector plates causes ions to flow to the plates. By means of electrostatic or magnetic deflection elements connected to an alternating potential, the ions are caused to flow alternately to each of the collector plates causing an a-c signal thereon.

  1. Spent-fuel verification measurements using passive and active radiation techniques

    SciTech Connect

    Ewing, R.I.; Seager, K.D.

    1996-08-01

    This paper describes an evolutionary development process that will lead to spent fuel measurements that directly measure fissile reactivity. First, the Fork measurement system has been used to verify the burnup of pressurized water reactor (PWR) spent-fuel assemblies at U.S. nuclear utilities. Fork measurements have demonstrated the utility of the passive Fork system to verify reactor records with a single 100-second measurement on each assembly. Second, an Advanced Fork system incorporating collimated gamma-ray spectroscopy has been designed to permit advanced calibration techniques that are independent of reactor burnup records and to allow rapid axial scanning of spent fuel assemblies. Third, an Active Fork system incorporating a neutron source to interrogate spent fuel is proposed to provide the capability to measure fissile reactivity, when compared to measurements on fresh fuel assemblies of the same design. The Advanced and Active Fork systems have wide applicability to spent fuel verification for PWR, boiling water reactor (BWR), and U.S. Department of Energy (DOE) spent fuel.

  2. Comparison of ground and satellite based measurements of the fraction of photosynthetically active radiation intercepted by tall-grass prairie

    NASA Technical Reports Server (NTRS)

    Demetriades-Shah, T. H.; Kanemasu, E. T.; Flitcroft, I.; Su, H.

    1990-01-01

    The fraction, of photosynthetically active radiation absorbed by vegetation, F sub ipar, is an important requirement for estimating vegetation biomass productivity and related quantities. This was an integral part of a large international effort; the First ISLSCP Field Experiment (FIFE). The main objective of FIFE was to study the effects of vegetation on the land atmosphere interactions and to determine if these interactions can be assessed from satellite spectral measurements. The specific purpose of this experiment was to find out how well measurements of F sub ipar relate to ground, helicopter, and satellite based spectral reflectance measurements. Concurrent measurements of F sub ipar and ground, helicopter, and satellite based measurements were taken at 13 tall grass prairie sites in Kansas. The sites were subjected to various combinations of burning and grazing managements.

  3. Effects of ultraviolet radiation on the type-I collagen protein triple helical structure: a method for measuring structural changes through optical activity.

    PubMed

    Majewski, Alexander J; Sanzari, Martin; Cui, Hong-Liang; Torzilli, Peter

    2002-03-01

    A detailed study of the effects of ultraviolet radiation on type-I collagen has been conducted. We have confirmed that exposure to ultraviolet radiation lowers the denaturation temperature of type-I collagen and that the triple helical state is destroyed provided that the radiation dose exceeds a threshold level, which is defined as the incident radiation dose that raises the sample temperature above the (lower) denaturation temperature. For incident radiation doses below threshold, the collagen molecule remains in a triple helical state. Denaturation is determined by changes in the optical activity of the collagen solution. Furthermore, a new instrument has been developed and tested to measure the optical rotatory dispersion properties of chiral molecules. The advantage of this instrument is that it enables a real-time measurement of the optical activity of chiral macromolecules while exposing samples to ultraviolet radiation and requiring no special sample preparation techniques. Using a differential measurement scheme, system errors have been minimized.

  4. Simple device measures solar radiation

    NASA Technical Reports Server (NTRS)

    Humphries, W. R.

    1977-01-01

    Simple inexpensive thermometer, insolated from surroundings by transparent glass or plastic encasement, measures intensities of solar radiation, or radiation from other sources such as furnaces or ovens. Unit can be further modified to accomplish readings from remote locations.

  5. Surface activity and radiation field measurements of the TMI-2 reactor building gross decontamination experiment

    SciTech Connect

    McIsaac, C V

    1983-10-01

    Surface samples were collected from concrete and metal surfaces within the Three Mile Island Unit 2 Reactor Building on December 15 and 17, 1981 and again on March 25 and 26, 1982. The Reactor Building was decontaminated by hydrolasing during the period between these dates. The collected samples were analyzed for radionuclide concentration at the Idaho National Engineering Laboratory. The sampling equipment and procedures, and the analysis methods and results are discussed. The measured mean surface concentrations of /sup 137/Cs and /sup 90/Sr on the 305-ft elevation floor before decontamination were, respectively, 3.6 +- 0.9 and 0.17 +- 0.04 ..mu..Ci/cm/sup 2/. Their mean concentrations on the 347-ft elevation floor were about the same. On both elevations, walls were found to be considerably less contaminated than floors. The fractions of the core inventories of /sup 137/Cs, /sup 90/Sr, and /sup 129/I deposited on Reactor Building surfaces prior to decontamination were calculated using their mean concentrations on various types of surfaces. The calculated values for these three nuclides are 3.5 +- 0.4 E-4, 2.4 +- 0.8 E-5, and 5.7 +- 0.5 E-4, respectively. The decontamination operations reduced the /sup 137/Cs surface activity on the 305- and 347-ft elevations by factors of 20 and 13, respectively. The /sup 90/Sr surface activity reduction was the same for both floors, that being a factor of 30. On the whole, decontamination of vertical surfaces was not achieved. Beta and gamma exposure rates that were measured during surface sampling were examined to determine the degree to which they correlated with measured surface activities. The data were fit with power functions of the form y = ax/sup b/. As might be expected, the beta exposure rates showed the best correlation. Of the data sets fit with the power function, the set of December 1981 beta exposure exhibited the least scatter. The coefficient of determination for this set was calculated to be 0.915.

  6. Center for Radiation Research. 1990 technical activities

    SciTech Connect

    Kuyatt, C.E.

    1991-02-01

    The report summarizes research projects, measurement method development, calibration and testing and data evaluation activities that were carried out during Fiscal Year 1990 in the NIST Center for Radiation Research. These activities fall in the areas of radiometric physics, radiation sources and instrumentation, and ionizing radiation.

  7. A new UK Greenhouse Gas measurement network providing ultra high-frequency measurements of key radiatively active trace gases taken from a network of tall towers

    NASA Astrophysics Data System (ADS)

    Grant, A.; O'Doherty, S.; Manning, A. J.; Simmonds, P. G.; Derwent, R. G.; Moncrieff, J. B.; Sturges, W. T.

    2012-04-01

    Monitoring of atmospheric concentrations of gases is important in assessing the impact of international policies related to the atmospheric environment. The effects of control measures on greenhouse gases introduced under the Montreal and Kyoto Protocols are now being observed. Continued monitoring is required to assess the overall success of the Protocols. For over 15 years the UK Government have funded high-frequency measurements of greenhouse gases and ozone depleting gases at Mace Head, a global background measurement station on the west coast of Ireland. These continuous, high-frequency, high-precision measurements are used to estimate regional (country-scale) emissions of greenhouse gases across the UK using an inversion methodology (NAME-Inversion) that links the Met Office atmospheric dispersion model (Numerical Atmospheric dispersion Modelling Environment - NAME) with the Mace Head observations. This unique inversion method acts to independently verify bottom up emission estimates of radiatively active and ozone-depleting trace gases. In 2011 the UK government (DECC) funded the establishment and integration of three new tall tower measurements stations in the UK, to provide enhanced resolution emission maps and decrease uncertainty of regional emission estimates produced using the NAME-Inversion. One station included in this new UK network was already established in Scotland and was used in collaboration with Edinburgh University. The two other new stations are in England and were set-up early in 2012, they contain brand new instrumentation for measurements of greenhouse gases. All three additional stations provide ultra high-frequency (1 sec) data of CO2 and CH4 using the Picarro© Cavity Ring Down Spectrometer and high frequency (20 min) measurements of N2O and SF6 from custom built sample modules with GC-ECD. We will present the new tall tower UK measurement network in detail. Using high-frequency measurements at new operational sites, including Mace

  8. Comparison of ground and satellite based measurements of the fraction of photosynthetically active radiation intercepted by tall-grass prairie

    SciTech Connect

    Demetriades-shah, T.H.; Kanemasu, E.T.; Flitcroft, I.D.; Su, H. Kansas State Univ., Manhattan )

    1992-11-01

    The fraction of photosynthetically active radiation intercepted by vegetation, F(sub ipar) is an important parameter for modeling the interactions between the land-surface and atmosphere and for estimating vegetation biomass productivity. This study was, therefore, an integral part of FIFE. The specific purpose of this experiment was to find out how well definitive measurements of F(sub ipar) on the ground relate to near-ground and satellite based spectral reflectance measurements. Concurrent measurements of F(sub ipar) and ground, helicopter, and satellite based reflectance measurements were taken at thirteen tall-grass prairie sites within the FIFE experimental area. The sites were subjected to various combinations of burning and grazing managements. The ground and helicopter based reflectance measurements were taken on the same day or few days from the time of the overpass of LANDSAT and SPOT satellites. Ground-based reflectance measurements and sun photometer readings taken at the times of the satellite overpasses were used to correct for atmospheric attenuation. Hand-held radiometer spectral indices were strongly correlated with helicopter and satellite based values (r = 0.94 for helicopter, 0.93 for LANDSAT Thematic Mapper, and 0.86 for SPOT). However, the ground, helicopter, and satellite based normalized difference spectral vegetation indices showed low sensitivity to changes in F(sub ipar). Reflectance measurements were only moderately well correlated with measurements of F(sub ipar) (r = 0.82 for hand-held radiometer, 0.84 for helicopter measurements, and 0.75 for the LANDSAT Thematic Mapper and SPOT). Improved spectral indices which can compensate for site differences are needed in order to monitor F(sub ipar) more reliably. 12 refs.

  9. Comparison of ground and satellite based measurements of the fraction of photosynthetically active radiation intercepted by tall-grass prairie

    NASA Technical Reports Server (NTRS)

    Demetriades-Shah, T. H.; Kanemasu, E. T.; Flitcroft, I. D.; Su, H.

    1992-01-01

    The fraction of photosynthetically active radiation intercepted by vegetation, F(sub ipar) is an important parameter for modeling the interactions between the land-surface and atmosphere and for estimating vegetation biomass productivity. This study was, therefore, an integral part of FIFE. The specific purpose of this experiment was to find out how well definitive measurements of F(sub ipar) on the ground relate to near-ground and satellite based spectral reflectance measurements. Concurrent measurements of F(sub ipar) and ground, helicopter, and satellite based reflectance measurements were taken at thirteen tall-grass prairie sites within the FIFE experimental area. The sites were subjected to various combinations of burning and grazing managements. The ground and helicopter based reflectance measurements were taken on the same day or few days from the time of the overpass of LANDSAT and SPOT satellites. Ground-based reflectance measurements and sun photometer readings taken at the times of the satellite overpasses were used to correct for atmospheric attenuation. Hand-held radiometer spectral indices were strongly correlated with helicopter and satellite based values (r = 0.94 for helicopter, 0.93 for LANDSAT Thematic Mapper, and 0.86 for SPOT). However, the ground, helicopter, and satellite based normalized difference spectral vegetation indices showed low sensitivity to changes in F(sub ipar). Reflectance measurements were only moderately well correlated with measurements of F(sub ipar) (r = 0.82 for hand-held radiometer, 0.84 for helicopter measurements, and 0.75 for the LANDSAT Thematic Mapper and SPOT). Improved spectral indices which can compensate for site differences are needed in order to monitor F(sub ipar) more reliably.

  10. Comparison of ground and satellite based measurements of the fraction of photosynthetically active radiation intercepted by tall-grass prairie

    NASA Technical Reports Server (NTRS)

    Demetriades-Shah, T. H.; Kanemasu, E. T.; Flitcroft, I.; Su, H.

    1991-01-01

    The fraction, of photosynthetically active radiation intercepted by vegetation, F(sub ipar) is an important parameter for modeling the interactions between the land-surface and atmosphere and for estimating vegetation biomass productivity. This study was; therefore, an integral part of FIFE. The specific purpose of this experiment was to find out how well definitive measurements of F(sub ipar) on the ground relate to near-ground and satellite based spectral reflectance measurements. Concurrent measurements of F(sub ipar) and ground, helicopter, and satellite based reflectance measurements were taken at thirteen tall-grass prairie sites within the FIFE experimental area. The sites were subjected to various combinations of burning and grazing managements. The ground and helicopter based reflectance measurements were taken on the same day or few days from the time of the overpass of LANDSAT and SPOT satellites. Ground-based reflectance measurements and sun photometer readings taken at the times of the satellite overpasses were used to correct for atmospheric attenuation. Hand-held radiometer spectral indices were strongly correlated with helicopter and satellite based values (r=0.94 for helicopter, 0.93 for LANDSAT Thematic Mapper, and 0.86 for SPOT). However, the ground, helicopter, and satellite based normalized difference spectral vegetation indices showed low sensitivity to changes in F(sub ipar). Reflectance measurements were only moderately well correlated with measurements of F(sub ipar) (r=0.82 for hand-held radiometer, 0.84 for helicopter measurements, and 0.75 for the LANDSAT Thematic Mapper and SPOT). Improved spectral indices which can compensate for site differences are needed in order to monitor F(sub ipar) more reliably.

  11. Measurement of stray radiation within a scanning proton therapy facility: EURADOS WG9 intercomparison exercise of active dosimetry systems

    SciTech Connect

    Farah, J. Trompier, F.; Mares, V.; Schinner, K.; Wielunski, M.; Romero-Expósito, M.; Domingo, C.; Trinkl, S.; Dufek, V.; Klodowska, M.; Liszka, M.; Stolarczyk, L.; Olko, P.; Kubancak, J.; and others

    2015-05-15

    Purpose: To characterize stray radiation around the target volume in scanning proton therapy and study the performance of active neutron monitors. Methods: Working Group 9 of the European Radiation Dosimetry Group (EURADOS WG9—Radiation protection in medicine) carried out a large measurement campaign at the Trento Centro di Protonterapia (Trento, Italy) in order to determine the neutron spectra near the patient using two extended-range Bonner sphere spectrometry (BSS) systems. In addition, the work focused on acknowledging the performance of different commercial active dosimetry systems when measuring neutron ambient dose equivalents, H{sup ∗}(10), at several positions inside (8 positions) and outside (3 positions) the treatment room. Detectors included three TEPCs—tissue equivalent proportional counters (Hawk type from Far West Technology, Inc.) and six rem-counters (WENDI-II, LB 6411, RadEye™ NL, a regular and an extended-range NM2B). Meanwhile, the photon component of stray radiation was deduced from the low-lineal energy transfer part of TEPC spectra or measured using a Thermo Scientific™ FH-40G survey meter. Experiments involved a water tank phantom (60 × 30 × 30 cm{sup 3}) representing the patient that was uniformly irradiated using a 3 mm spot diameter proton pencil beam with 10 cm modulation width, 19.95 cm distal beam range, and 10 × 10 cm{sup 2} field size. Results: Neutron spectrometry around the target volume showed two main components at the thermal and fast energy ranges. The study also revealed the large dependence of the energy distribution of neutrons, and consequently of out-of-field doses, on the primary beam direction (directional emission of intranuclear cascade neutrons) and energy (spectral composition of secondary neutrons). In addition, neutron mapping within the facility was conducted and showed the highest H{sup ∗}(10) value of ∼51 μSv Gy{sup −1}; this was measured at 1.15 m along the beam axis. H{sup ∗}(10) values

  12. Measurement of solar radiation

    SciTech Connect

    Braunstein, A.; Levite, T.; Sohar, E.

    1984-11-27

    There is provided a device for indicating the level of solar radiation intensity, and especially that region of the spectrum in the ultraviolet region which causes sunburn. The device may be provided with an output subdivided into a plurality of discrete levels of intensity indicated as numerals and figures. It may be provided with means of adjustment to the physiology of the user.

  13. Acoustic radiation stress measurement

    NASA Technical Reports Server (NTRS)

    Cantrell, John H., Jr.; Yost, William T.

    1987-01-01

    Ultrasonic radio frequency tone-bursts are launched into a sample of material tested. The amplitude of the tone-bursts and the slope of the resulting static displacement pulses are measured. These measurements are used to calculate the nonlinearities of the materials.

  14. EXOMARS IRAS (DOSE) radiation measurements.

    NASA Astrophysics Data System (ADS)

    Federico, C.; Di Lellis, A. M.; Fonte, S.; Pauselli, C.; Reitz, G.; Beaujean, R.

    The characterization and the study of the radiations on their interaction with organic matter is of great interest in view of the human exploration on Mars. The Ionizing RAdiation Sensor (IRAS) selected in the frame of the ExoMars/Pasteur ESA mission is a lightweight particle spectrometer combining various techniques of radiation detection in space. It characterizes the first time the radiation environment on the Mars surface, and provide dose and dose equivalent rates as precursor information absolutely necessary to develop ways to mitigate the radiation risks for future human exploration on Mars. The Martian radiation levels are much higher than those found on Earth and they are relatively low for space. Measurements on the surface will show if they are similar or not to those seen in orbit (modified by the presence of ``albedo'' neutrons produced in the regolith and by the thin Martian atmosphere). IRAS consists of a telescope based on segmented silicon detectors of about 40\\userk\\milli\\metre\\user;k diameter and 300\\user;k\\micro\\metre\\user;k thickness, a segmented organic scintillator, and of a thermoluminescence dosimeter. The telescope will continuously monitor temporal variation of the particle count rate, the dose rate, particle and LET (Linear Energy Transfer) spectra. Tissue equivalent BC430 scintillator material will be used to measure the neutron dose. Neutrons are selected by a criteria requiring no signal in the anti-coincidence. Last, the passive thermoluminescence dosimeter, based on LiF:Mg detectors, regardless the on board operation timing, will measure the total dose accumulated during the exposure period and due to beta and gamma radiation, with a responsivity very close to that of a human tissue.

  15. Surface-Satellite Measurements for Atmospheric Radiative Transfer (SMART)and Chemical, Optical and Microphysical Measurements of In-Situ Troposphere (COMMIT) Research Activities

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee

    2004-01-01

    The GSFC SMART consists of a suite of remote sensing instruments, including many commercially available radiometers, spectrometer, interferometer, and three in-house developed inskuments: micro-pulse lidar (MPL), scanning microwave radiometer (SMiR), and sun-sky-surface photometer (S(sup 3)). SMART cover the spectral range from UV to microwave, and passive to active remote sensing. This is to enrich the EOS-like research activities (i.e., EOS validation, innovative investigations, and long-term local environmental observations). During past years, SMART has been deployed in many NASA supported field campaigns to collocate with satellite nadir overpass for intercomparisons, and for initializing model simulations. Built on the successful experience of SMART, we are currently developing a new ground-based in-situ sampling package, COMMIT, including measurements of trace gases (CO, SO2, NOx, and O3,) concentrations, fine/coarse particle sizers and chemical composition, single- and three-wavelength nephelometers, and surface meteorological probes. COMMIT is built for seeking a relationship between surface in-situ measurements and boundary layer characteristics. This is to enrich EOS-like research on removing boundary layer signal from the entire column from space observation - to deduce the stable (less variability) free-troposphere observations. The COMMIT will try its best to link the chemical, microphysical, and optical properties of the boundary layer with radiation. The next major activities for SMART-COMMIT are scheduled for 2004-2006 in BASE-ASIA and EAST-AIRE. The expected close collaboration of BASE-ASIA with various research projects in Asia (i.e., ABC in South Asia, led by Ramanathan et al.; EAST-AIRE in East Asia, led by Li et al.; and APEX in Northeast Asia, led by Nakajima et al.) will definitely provide a better understanding of the impact of the biomass burning and air pollutants on regional-to-global climate, hydrological and carbon cycles, and

  16. Radiation Measurements aboard Spacelab 1

    NASA Astrophysics Data System (ADS)

    Benton, E. V.; Almasi, J.; Cassou, R.; Frank, A.; Henke, R. P.; Rowe, V.; Parnell, T. A.; Schopper, E.

    1984-07-01

    The radiation environment inside Spacelab 1 was measured by a set of passive radiation detectors distributed throughout the volume inside the module, in the access tunnel, and outside on the pallet. Measurements of the low-LET (linear energy transfer) component obtained from the thermoluminescence detectors ranged from 102 to 190 millirads, yielding an average low-LET dose rate of 11.2 millirads per day inside the module, about twice the low-LET dose rate measured on previous flights of the space shuttle. Because of the higher inclination of the orbit (57 degrees versus 28.5 degrees for previous shuttle flights), substantial fluxes of highly ionizing HZE particles (high charge and energy galactic cosmic rays) were observed, yielding an overall average mission dose-equivalent of about 150 millirems, more than three times higher that measured on previous shuttle missions.

  17. Radiation measurements aboard Spacelab 1

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Almasi, J.; Cassou, R.; Frank, A.; Henke, R. P.; Rowe, V.; Parnell, T. A.; Schopper, E.

    1984-01-01

    The radiation environment inside Spacelab 1 was measured by a set of passive radiation detectors distributed throughout the volume inside the module, in the access tunnel, and outside on the pallet. Measurements of the low linear energy transfer (LET) component obtained from the thermoluminescence detectors ranged from 102 to 190 millirads, yielding an average low LET dose rate of 11.2 millirads/day inside the module, about twice the low LET dose rate measured on previous flights of the Space Shuttle. Because of the higher inclination of the orbit (57 versus 28.5 deg for previous Shuttle flights), substantial fluxes of highly ionizing high charge and energy galactic cosmic ray particles were observed, yielding an overall average mission dose-equivalent of about 150 millirems, more than three times higher than that measured on previous Shuttle missions.

  18. Radiation budget measurement/model interface

    NASA Technical Reports Server (NTRS)

    Vonderhaar, T. H.; Ciesielski, P.; Randel, D.; Stevens, D.

    1983-01-01

    This final report includes research results from the period February, 1981 through November, 1982. Two new results combine to form the final portion of this work. They are the work by Hanna (1982) and Stevens to successfully test and demonstrate a low-order spectral climate model and the work by Ciesielski et al. (1983) to combine and test the new radiation budget results from NIMBUS-7 with earlier satellite measurements. Together, the two related activities set the stage for future research on radiation budget measurement/model interfacing. Such combination of results will lead to new applications of satellite data to climate problems. The objectives of this research under the present contract are therefore satisfied. Additional research reported herein includes the compilation and documentation of the radiation budget data set a Colorado State University and the definition of climate-related experiments suggested after lengthy analysis of the satellite radiation budget experiments.

  19. WE-D-17A-05: Measurement of Stray Radiation Within An Active Scanning Proton Therapy Facility: EURADOS WG9 Intercomparison Exercise of Active Dosimetry Systems

    SciTech Connect

    Farah, J; Trompier, F; Stolarczyk, L; Klodowska, M; Liszka, M; Olko, P; Algranati, C; Fellin, F; Schwarz, M; Domingo, C; Romero-Exposito, M; Dufek, V; Frojdh, E; George, S; Harrison, R; Kubancak, J; Ploc, O; Knezevic, Z; Majer, M; Miljanic, S; and others

    2014-06-15

    Purpose: Intercomparison of active dosemeters in the measurement of stray radiation at the Trento active-scanning proton therapy facility. Methods: EURADOS WG9 carried out a large intercomparison exercise to test different dosemeters while measuring secondary neutrons within a 230 MeV scanned proton therapy facility. Detectors included two Bonner Sphere Spectrometers (BSS), three tissue equivalent proportional counters (TEPCHawk) and six rem-counters (Wendi II, Berthold, RadEye, a regular and an extended-range Anderson and Braun NM2B counters). Measurements of neutron ambient dose equivalents, H*(10), were done at several positions inside (8 positions) and outside (3 positions) the treatment room while irradiating a water tank phantom with a 10 × 10 × 10 cc field. Results: A generally good agreement on H*(10) values was observed for the tested detectors. At distance of 2.25 m and angles 45°, 90° and 180° with respect to the beam axis, BSS and proportional counters agreed within 30%. Higher differences (up to 60%) were observed at the closest and farthest distances, i.e. at positions where detectors sensitivity, energy, fluence and angular response are highly dependent on neutron spectra (flux and energy). The highest neutron H*(10) value, ∼60 microSv/Gy, was measured at 1.15 m along the beam axis. H*(10) decreased significantly with the distance from the isocenter dropping to 1.1 microSv/Gy at 4.25 m and 90° from beam axis, ∼2 nanoSv/Gy at the entrance of the maze, 0.2 nanoSv/Gy at the door outside the room and below detection limit in the gantry control room and at an adjacent room. These values remain considerately lower than those of passively scattered proton beams. BSS and Hawk unfolded spectra provide valuable inputs when studying the response of each detector. Conclusion: TEPCs and BSS enable accurate measurements of stray neutrons while other rem-meters also give satisfactory results but require further improvements to reduce uncertainties.

  20. Neutron radiation measurements on several international flights.

    PubMed

    Poje, Marina; Vuković, Branko; Radolić, Vanja; Miklavčić, Igor; Planinić, Josip

    2015-03-01

    The earth is continually exposed to cosmic radiation of both solar and galactic origin. High-energy particles interact with the constituents in the atmosphere producing secondary particles that create radiation fields at aircraft altitudes. These secondary particles consist mainly of photons, protons, neutrons, charged and uncharged pions, and muons. The neutron component dominates the hadron cascade at lower altitudes as a result of its longer mean free path. Since air transportation has become more available to a greater number of people, this has led to an increase in the number of persons exposed to ionizing radiation of cosmic origin. This concerns pilots and cabin crews as well as frequent flyers. A neutron component of cosmic radiation was measured using an LR 115/CR-39 track detector associated with a 10B converter foil. The measurement of the neutron dose is a good approximation of the total dose since neutrons carry about 50% of the total ambient dose equivalent at aircraft altitudes. Also, the results of the measurements were compared with the data obtained by EPCARD software simulation. The measured neutron dose rate had a span from 0.36 to 8.83 μSv h(-1) (dose enhancement due to high solar activity in the flight period). PMID:25627946

  1. Neutron radiation measurements on several international flights.

    PubMed

    Poje, Marina; Vuković, Branko; Radolić, Vanja; Miklavčić, Igor; Planinić, Josip

    2015-03-01

    The earth is continually exposed to cosmic radiation of both solar and galactic origin. High-energy particles interact with the constituents in the atmosphere producing secondary particles that create radiation fields at aircraft altitudes. These secondary particles consist mainly of photons, protons, neutrons, charged and uncharged pions, and muons. The neutron component dominates the hadron cascade at lower altitudes as a result of its longer mean free path. Since air transportation has become more available to a greater number of people, this has led to an increase in the number of persons exposed to ionizing radiation of cosmic origin. This concerns pilots and cabin crews as well as frequent flyers. A neutron component of cosmic radiation was measured using an LR 115/CR-39 track detector associated with a 10B converter foil. The measurement of the neutron dose is a good approximation of the total dose since neutrons carry about 50% of the total ambient dose equivalent at aircraft altitudes. Also, the results of the measurements were compared with the data obtained by EPCARD software simulation. The measured neutron dose rate had a span from 0.36 to 8.83 μSv h(-1) (dose enhancement due to high solar activity in the flight period).

  2. Methods of and apparatus for radiation measurement, and specifically for in vivo radiation measurement

    DOEpatents

    Huffman, D.D.; Hughes, R.C.; Kelsey, C.A.; Lane, R.; Ricco, A.J.; Snelling, J.B.; Zipperian, T.E.

    1986-08-29

    Methods of and apparatus for in vivo radiation measurements rely on a MOSFET dosimeter of high radiation sensitivity which operates in both the passive mode to provide an integrated dose detector and active mode to provide an irradiation rate detector. A compensating circuit with a matched unirradiated MOSFET is provided to operate at a current designed to eliminate temperature dependence of the device. Preferably, the MOSFET is rigidly mounted in the end of a miniature catheter and the catheter is implanted in the patient proximate the radiation source.

  3. Actively driven thermal radiation shield

    DOEpatents

    Madden, Norman W.; Cork, Christopher P.; Becker, John A.; Knapp, David A.

    2002-01-01

    A thermal radiation shield for cooled portable gamma-ray spectrometers. The thermal radiation shield is located intermediate the vacuum enclosure and detector enclosure, is actively driven, and is useful in reducing the heat load to mechanical cooler and additionally extends the lifetime of the mechanical cooler. The thermal shield is electrically-powered and is particularly useful for portable solid-state gamma-ray detectors or spectrometers that dramatically reduces the cooling power requirements. For example, the operating shield at 260K (40K below room temperature) will decrease the thermal radiation load to the detector by 50%, which makes possible portable battery operation for a mechanically cooled Ge spectrometer.

  4. Active personal radiation monitor for lunar EVA

    NASA Astrophysics Data System (ADS)

    Straume, Tore; Borak, Tom; Braby, L. A.; Lusby, Terry; Semones, Edward J.; Vazquez, Marcelo E.

    As astronauts return to the Moon-and this time, work for extended periods-there will be a critical need for crew personnel radiation monitoring as they operate lunar rovers or otherwise perform a myriad of extravehicular activities (EVAs). Our focus is on development of a small personal radiation monitor for lunar EVA that responds to the complex radiation quality and changing dose rates on the Moon. Of particular concern are active monitoring capabilities that provide both early warning and radiation dosimetry information during solar particle events (SPEs). To accomplish this, we are developing small detectors integrated with modern high speed, low power microelectronics to measure dose-rate and dose-mean lineal energy in real time. The monitor is designed to perform over the range of dose rates and LETs expected from both GCR and SPE radiations during lunar EVA missions. The monitor design provides simultaneous measurement of dose-equivalent rates at two tissue-equivalent depths simulating skin and marrow. The compact personal monitor is estimated to be the size of a cell phone and would fit on an EVA spacesuit (e.g., in backpack) or in a toolbox. The four-year development effort (which began December 2007) will result in a prototype radiation monitor field tested and characterized for the major radiations expected on the surface of the Moon. We acknowledge support from NSBRI through grants to NASA Ames Research Center (T. Straume, PI) and Colorado State University (T. Borak, PI).

  5. Radiation exposure measurement onboard civil aircraft.

    PubMed

    Beaujean, R; Burmeister, S; Petersen, F; Reitz, G

    2005-01-01

    The active dosemeter DOSTEL based on two silicon planar detectors was flown on civil aircraft flights to study the radiation exposure of air crew members. The altitude and latitude dependence of count and dose rates as well as long-term variations are measured. After calibration of the DOSTEL response against measurements of a TEPC instrument, total dose-equivalent values for various flights are compared with H*(10) calculations by EPCARD yielding a ratio of 1.02 +/- 0.09 (standard variation).

  6. Method and Apparatus for Measuring Radiation Quantities

    DOEpatents

    Roberts, N O

    1955-01-25

    This patent application describes a compact dosimeter for measuring X-ray and gamma radiation by the use of solutions which undergo a visible color change upon exposure to a predetermined quantity of radiation.

  7. Radiation Detection for Active Interrogation of HEU

    SciTech Connect

    Mihalczo, J.T.

    2004-12-09

    This report briefly describes the neutrons and gamma rays emitted by active interrogation of HEU, briefly discusses measurement methods, briefly discusses sources and detectors relevant to detection of shielded HEU in Sealand containers, and lists the measurement possibilities for the various sources. All but one of the measurement methods detect radiation emitted by induced fission in the HEU; the exception utilizes nuclear resonance fluorescence. The brief descriptions are supplemented by references. This report presents some active interrogation possibilities but the status of understanding is not advanced enough to select particular methods. Additional research is needed to evaluate these possibilities.

  8. Lawrence Livermore National Laboratory?s Book of Minimum Detectable Activity for Direct Measurement of Internally Deposited Radionuclides in Radiation Workers

    SciTech Connect

    Hickman, D P

    2008-10-08

    Lawrence Livermore National Laboratory maintains an in vivo measurement program designed to identify and evaluate the activity of radionuclides deposited in the body. Two types of systems are primarily used for the routine monitoring of radiation workers, the lung counting system and the scanning bed whole body counting system. The lung counting system is comprised of two Canberra ACTII detector sets. Each ACTII set contains two planar germanium detectors with carbon composite end windows optimized to measure low energy photon emitting radionuclides. The ACTII detectors are placed on the upper torso over the lungs for the direct measurement of internally deposited radionuclides in the lungs that emit low energy photons. A correction for the thickness of the chest wall is applied to the efficiency. Because the thickness of the chest wall is a key factor in the measurement of low energy photon emitting radionuclides in the lung, the minimum detectable activity is a function of the chest wall thickness. The scanning bed whole body counting system is comprised of a thin air mattress on top of a carbon fiber bed that slowly scans over four high purity germanium detectors. The scanning system is designed to minimize variations in detected activity due to radionuclide distribution in the body. The scanning bed detection system is typically used for the measurement of internally deposited radionuclides that emit photons above 100 to 200 keV. MDAs have been generated for radionuclides that provide energies above 80 keV since the lowest calibration energy for the system is approximately 86 keV. The following charts and table provide best determination of minimum detectable activity using human subjects as controls for the background contributions. A wide variety of radionuclides are used throughout the laboratory and the following pages represent several of the radionuclides that have been encountered at the Whole Body and Spectroscopy Laboratories within Hazards Control.

  9. Radiation dose measurements in coronary CT angiography

    PubMed Central

    Sabarudin, Akmal; Sun, Zhonghua

    2013-01-01

    Coronary computed tomography (CT) angiography is associated with high radiation dose and this has raised serious concerns in the literature. Awareness of various parameters for dose estimates and measurements of coronary CT angiography plays an important role in increasing our understanding of the radiation exposure to patients, thus, contributing to the implementation of dose-saving strategies. This article provides an overview of the radiation dose quantity and its measurement during coronary CT angiography procedures. PMID:24392190

  10. Method for radiation detection and measurement

    DOEpatents

    Miller, S.D.

    1993-12-21

    Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength. 9 figures.

  11. Method for radiation detection and measurement

    DOEpatents

    Miller, Steven D.

    1993-01-01

    Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength.

  12. NCRP Program Area Committee 6: Radiation Measurements and Dosimetry.

    PubMed

    Simon, Steven L; Zeman, Gary H

    2016-02-01

    Program Area Committee (PAC) 6 of the National Council on Radiation Protection and Measurements provides guidance for radiation measurements and dosimetry--one of the most fundamental scientific areas of the Council's expertise. Seminal reports published by PAC 6 over many decades have documented the scientific and technical foundations of radiation measurements and dosimetry for generations of radiation scientists and radiation protection professionals. Ongoing work of PAC 6 is driven by advancing technology, such as development of new types of instruments, biodosimetry and nanotechnology; by evolving understanding of radiation hazards, such as effects on the lens of the eye and risks as from some high-dose medical imaging procedures; and by new situations faced in the modern socio-political environment including radiological and nuclear threats. The activities of PAC 6 are intended to formulate and document the dosimetric framework for radiological science to address these ever-emerging challenges. PMID:26717161

  13. NCRP Program Area Committee 6: Radiation Measurements and Dosimetry.

    PubMed

    Simon, Steven L; Zeman, Gary H

    2016-02-01

    Program Area Committee (PAC) 6 of the National Council on Radiation Protection and Measurements provides guidance for radiation measurements and dosimetry--one of the most fundamental scientific areas of the Council's expertise. Seminal reports published by PAC 6 over many decades have documented the scientific and technical foundations of radiation measurements and dosimetry for generations of radiation scientists and radiation protection professionals. Ongoing work of PAC 6 is driven by advancing technology, such as development of new types of instruments, biodosimetry and nanotechnology; by evolving understanding of radiation hazards, such as effects on the lens of the eye and risks as from some high-dose medical imaging procedures; and by new situations faced in the modern socio-political environment including radiological and nuclear threats. The activities of PAC 6 are intended to formulate and document the dosimetric framework for radiological science to address these ever-emerging challenges.

  14. Radiation: Physical Characterization and Environmental Measurements

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In this session, Session WP4, the discussion focuses on the following topics: Production of Neutrons from Interactions of GCR-Like Particles; Solar Particle Event Dose Distributions, Parameterization of Dose-Time Profiles; Assessment of Nuclear Events in the Body Produced by Neutrons and High-Energy Charged Particles; Ground-Based Simulations of Cosmic Ray Heavy Ion Interactions in Spacecraft and Planetary Habitat Shielding Materials; Radiation Measurements in Space Missions; Radiation Measurements in Civil Aircraft; Analysis of the Pre-Flight and Post-Flight Calibration Procedures Performed on the Liulin Space Radiation Dosimeter; and Radiation Environment Monitoring for Astronauts.

  15. Measurement and Applications of Radiation Pressure

    NASA Astrophysics Data System (ADS)

    Ma, Dakang; Garrett, Joseph; Murray, Joseph; Munday, Jeremy; Munday Lab Team

    Light reflected off a material or absorbed within it exerts radiation pressure through the transfer of momentum. Measuring and utilizing radiation pressure have aroused growing interest in a wide spectrum of research fields. Micromechanical transducers and oscillators are good candidates for measuring radiation pressure, but accompanying photothermal effects often obscure the measurement. In this work, we investigate the accurate measurement of the radiation force on microcantilevers in ambient conditions and ways to separate radiation pressure and photothermal effects. Further, we investigate an optically broadband switchable device based on polymer dispersed liquid crystal which has potential applications in solar sails and maneuvering spacecraft without moving parts. The authors would like to thank NASA Early Career Faculty Award and NASA Smallsat Technology Partnership Award for their funding support.

  16. New radiation detectors for field measurements

    SciTech Connect

    Bhattacharjie, A.; Quam, W.

    1993-12-31

    Two new types of radiation detectors are discussed; the first is a large area TLD and the second is a high pressure xenon proportional counter. The large area TLD can be used to measure In situ alpha activity with high spatial resolution and high sensitivity. Some field measurements are presented. The high pressure xenon proportional counter (XGPC) is capable of realtime survey work and monitoring of plutonium (through detection of the 60 keV Americium-241 gamma ray) and uranium. Spectral resolution data from the 8 atmosphere proportional counter are presented. In many applications the counting efficiency penalty due to low stopping power of xenon at higher gamma energies can be offset by increasing gas pressure and using physically long counters.

  17. SUMER: Solar Ultraviolet Measurements of Emitted Radiation

    NASA Technical Reports Server (NTRS)

    Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.; Grewing, M.; Huber, M. C. E.; Jordan, S. D.; Kuehne, M.; Lemaire, P.; Marsch, E.

    1992-01-01

    The experiment Solar Ultraviolet Measurements of Emitted Radiation (SUMER) is designed for the investigations of plasma flow characteristics, turbulence and wave motions, plasma densities and temperatures, structures and events associated with solar magnetic activity in the chromosphere, the transition zone and the corona. Specifically, SUMER will measure profiles and intensities of Extreme Ultraviolet (EUV) lines emitted in the solar atmosphere ranging from the upper chromosphere to the lower corona; determine line broadenings, spectral positions and Doppler shifts with high accuracy, provide stigmatic images of selected areas of the Sun in the EUV with high spatial, temporal and spectral resolution and obtain full images of the Sun and the inner corona in selectable EUV lines, corresponding to a temperature from 10,000 to more than 1,800,000 K.

  18. Radiation Measured during ISS-Expedition 13 with Different Dosimeters

    NASA Technical Reports Server (NTRS)

    Zhou, D.; Semones, E.; Gaza, R.; Johnson, S.; Zapp, N.; Lee, K.; George, T.

    2008-01-01

    Radiation in low Earth orbit (LEO) is mainly composed of Galactic Cosmic Rays (GCR), solar energetic particles and particles in SAA (South Atlantic Anomaly). The biological impact of space radiation to astronauts depends strongly on the particles linear energy transfer (LET) and is dominated by high LET radiation. It is important to measure the LET spectrum for the space radiation field and to investigate the influence of radiation on astronauts. At present, the preferred active dosimeters sensitive to all LET are the tissue equivalent proportional counter (TEPC) and silicon detectors in various configurations; the preferred passive dosimeters are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) sensitive to low LET as well as CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. The TEPC, CR-39 PNTDs, TLDs and OSLDs were used to investigate the radiation exposure for the ISS mission Expedition 13 (ISS-12S) in LEO. LET spectra and radiation quantities (fluence, absorbed dose, dose equivalent and quality factor) were measured for the space mission with different dosimeters. This paper introduces the operational principles for the dosimeters, describes the method to combine the results measured by TLDs/OSLDs and CR-39 PNTDs, and presents the LET spectra and the radiation quantities measured. Keywords: space radiation; cosmic rays; active and passive dosimeters; LET spectra

  19. Radiative flux measurements in the stratosphere

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1990-01-01

    The objective is to determine how the stratospheric tropospheric exchange of water vapor is affected by the interaction of solar (visible) and planetary (infrared) radiation with tropical cumulonimbus anvils. This research involves field measurements from the ER-2 aircraft as well as radiative transfer modelling to determine heating and cooling rates and profiles that directly affect the exchange between the troposphere and the stratosphere.

  20. Array Of Sensors Measures Broadband Radiation

    NASA Technical Reports Server (NTRS)

    Hoffman, James W.; Grush, Ronald G.

    1994-01-01

    Multiple broadband radiation sensors aimed at various portions of total field of view. All sensors mounted in supporting frame, serving as common heat sink and temperature reference. Each sensor includes heater winding and differential-temperature-sensing bridge circuit. Power in heater winding adjusted repeatedly in effort to balance bridge circuit. Intended to be used aboard satellite in orbit around Earth to measure total radiation emitted, at various viewing angles, by mosaic of "footprint" areas (each defined by its viewing angle) on surface of Earth. Modified versions of array useful for angle-resolved measurements of broadband radiation in laboratory and field settings on Earth.

  1. MEASURING TEMPORAL PHOTON BUNCHING IN BLACKBODY RADIATION

    SciTech Connect

    Tan, P. K.; Poh, H. S.; Kurtsiefer, C.; Yeo, G. H.; Chan, A. H. E-mail: phyck@nus.edu.sg

    2014-07-01

    Light from thermal blackbody radiators such as stars exhibits photon bunching behavior at sufficiently short timescales. However, with available detector bandwidths, this bunching signal is difficult to observe directly. We present an experimental technique to increase the photon bunching signal in blackbody radiation via spectral filtering of the light source. Our measurements reveal strong temporal photon bunching from blackbody radiation, including the Sun. This technique allows for an absolute measurement of the photon bunching signature g {sup (2)}(0), and thereby a direct statement on the statistical nature of a light source. Such filtering techniques may help revive the interest in intensity interferometry as a tool in astronomy.

  2. SUMER: Solar Ultraviolet Measurements of Emitted Radiation

    NASA Technical Reports Server (NTRS)

    Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.; Grewing, M.; Huber, M. C. E.; Jordan, M. C. E.; Lemaire, P.; Marsch, E.; Poland, A. I.

    1988-01-01

    The SUMER (solar ultraviolet measurements of emitted radiation) experiment is described. It will study flows, turbulent motions, waves, temperatures and densities of the plasma in the upper atmosphere of the Sun. Structures and events associated with solar magnetic activity will be observed on various spatial and temporal scales. This will contribute to the understanding of coronal heating processes and the solar wind expansion. The instrument will take images of the Sun in EUV (extreme ultra violet) light with high resolution in space, wavelength and time. The spatial resolution and spectral resolving power of the instrument are described. Spectral shifts can be determined with subpixel accuracy. The wavelength range extends from 500 to 1600 angstroms. The integration time can be as short as one second. Line profiles, shifts and broadenings are studied. Ratios of temperature and density sensitive EUV emission lines are established.

  3. Evaluation of arctic broadband surface radiation measurements

    NASA Astrophysics Data System (ADS)

    Matsui, N.; Long, C. N.; Augustine, J.; Halliwell, D.; Uttal, T.; Longenecker, D.; Nievergall, O.; Wendell, J.; Albee, R.

    2011-08-01

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

  4. Evaluation of Arctic broadband surface radiation measurements

    NASA Astrophysics Data System (ADS)

    Matsui, N.; Long, C. N.; Augustine, J.; Halliwell, D.; Uttal, T.; Longenecker, D.; Niebergall, O.; Wendell, J.; Albee, R.

    2012-02-01

    The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW) and thermal infrared, or longwave (LW), radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse) SW measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

  5. Evaluation of Arctic Broadband Surface Radiation Measurements

    SciTech Connect

    Matsui, N.; Long, Charles N.; Augustine, J. A.; Halliwell, D.; Uttal, Taneil; Longenecker, D.; Niebergale, J.; Wendell, J.; Albee, R.

    2012-02-24

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

  6. Inversion of Multi-Angle Radiation Measurement

    SciTech Connect

    Cairns, B.; Alexandrov, M. Lacis, A.; Carlson, B.

    2005-03-18

    Our need to reconcile models and measurements in an efficient manner that allows for the operational retrieval of particle sizes for a two layer cloud led us to develop a new method for calculating the Green's functions for radiative transfer. The method uses the fact that doubling/adding codes can be easily used to calculate internal radiation fields at arbitrarily high resolution. We have also determined that the adjoint downwelling and upwelling vector radiation fields are simply related to the usual downwelling and upwelling vector radiation fields so that the entire Green's function can be determined from a single calculation. The Green's functions have then been used to calculate the particle sizes in a two layer cloud that are consistent with both the reflectance and polarization measurements. This approach may be of use in other applications where adjoint calculations are used, particularly if multiangle measurements are being analyzed.

  7. Radiation Transmission Measurements for a Lightweight Fabric

    SciTech Connect

    Friedman, H; Singh, M S; DeMeo, R F

    2003-01-17

    Radiation Shield Technologies has developed a lightweight fabric, shown in Fig. 1, with radiation shielding properties for X ray, gamma ray and beta particle emissions in the range of energies relevant to clinical and Homeland Security applications. Detailed measurements were done to measure the shielding properties of this material against the spectra of standard radionuclides and x-ray generators. The mass attenuation coefficients were calculated using LLNL cross section data, a 3-D photon transport code, elemental weight fractions and the measured density of the fabric.

  8. Measurements of the diffuse ultraviolet radiation

    NASA Technical Reports Server (NTRS)

    Fix, John D.; Craven, John D.; Frank, Louis A.

    1989-01-01

    The imaging instrumentation on the Dynamics Explorer 1 satellite has been used to measure the intensity of the diffuse ultraviolet radiation on two great circles about the sky. It is found that the isotropic component of the diffuse ultraviolet radiation (possibly of extragalactic origin) has an intensity of 530 + or - 80 units (a unit is 1 photon per sq cm s A sr) at a wavelength of 150 nm. The Galactic component of the diffuse ultraviolet radiation has a dependence on Galactic latitude which requires strongly forward scattering particles if it is produced by dust above the Galactic plane.

  9. Optical Measurement Technologies for High Temperature, Radiation Exposure, and Corrosive Environments—Significant Activities and Findings: In-vessel Optical Measurements for Advanced SMRs

    SciTech Connect

    Anheier, Norman C.; Cannon, Bret D.; Qiao, Hong; Suter, Jonathan D.

    2012-09-01

    Development of advanced Small Modular Reactors (aSMRs) is key to providing the United States with a sustainable, economically viable, and carbon-neutral energy source. The aSMR designs have attractive economic factors that should compensate for the economies of scale that have driven development of large commercial nuclear power plants to date. For example, aSMRs can be manufactured at reduced capital costs in a factory and potentially shorter lead times and then be shipped to a site to provide power away from large grid systems. The integral, self-contained nature of aSMR designs is fundamentally different than conventional reactor designs. Future aSMR deployment will require new instrumentation and control (I&C) architectures to accommodate the integral design and withstand the extreme in-vessel environmental conditions. Operators will depend on sophisticated sensing and machine vision technologies that provide efficient human-machine interface for in-vessel telepresence, telerobotic control, and remote process operations. The future viability of aSMRs is dependent on understanding and overcoming the significant technical challenges involving in-vessel reactor sensing and monitoring under extreme temperatures, pressures, corrosive environments, and radiation fluxes

  10. MSL-RAD radiation environment measurements.

    PubMed

    Guo, Jingnan; Zeitlin, Cary; Wimmer-Schweingruber, Robert F; Hassler, Donald M; Ehresmann, Bent; Köhler, Jan; Böhm, Eckart; Böttcher, Stephan; Brinza, David; Burmeister, Sönke; Cucinotta, Francis; Martin, Cesar; Posner, Arik; Rafkin, Scot; Reitz, Guenther

    2015-09-01

    In this study, results are presented from the on-board radiation assessment detector (RAD) of Mars Science Laboratory (MSL). RAD is designed to measure the energetic particle radiation environment, which consists of galactic cosmic rays (GCRs) and solar energetic particles (SEPs) as well as secondary particles created by nuclear interactions of primary particles in the shielding (during cruise) or Martian soil and atmosphere (surface measurements). During the cruise, RAD collected data on space radiation from inside the craft, thus allowing for a reasonable estimation of what a human crew travelling to/from Mars might be exposed to. On the surface of Mars, RAD is shielded by the atmosphere (from above) and the planet itself (from below). RAD measures the first detailed radiation data from the surface of another planet, and they are highly relevant for planning future crewed missions. The results for radiation dose and dose equivalent (a quantity most directly related to human health risk) are presented during the cruise phase, as well as on the Martian surface. Dose and dose equivalent are dominated by the continuous GCR radiation, but several SEP events were also detected and are discussed here.

  11. MSL-RAD radiation environment measurements.

    PubMed

    Guo, Jingnan; Zeitlin, Cary; Wimmer-Schweingruber, Robert F; Hassler, Donald M; Ehresmann, Bent; Köhler, Jan; Böhm, Eckart; Böttcher, Stephan; Brinza, David; Burmeister, Sönke; Cucinotta, Francis; Martin, Cesar; Posner, Arik; Rafkin, Scot; Reitz, Guenther

    2015-09-01

    In this study, results are presented from the on-board radiation assessment detector (RAD) of Mars Science Laboratory (MSL). RAD is designed to measure the energetic particle radiation environment, which consists of galactic cosmic rays (GCRs) and solar energetic particles (SEPs) as well as secondary particles created by nuclear interactions of primary particles in the shielding (during cruise) or Martian soil and atmosphere (surface measurements). During the cruise, RAD collected data on space radiation from inside the craft, thus allowing for a reasonable estimation of what a human crew travelling to/from Mars might be exposed to. On the surface of Mars, RAD is shielded by the atmosphere (from above) and the planet itself (from below). RAD measures the first detailed radiation data from the surface of another planet, and they are highly relevant for planning future crewed missions. The results for radiation dose and dose equivalent (a quantity most directly related to human health risk) are presented during the cruise phase, as well as on the Martian surface. Dose and dose equivalent are dominated by the continuous GCR radiation, but several SEP events were also detected and are discussed here. PMID:25969529

  12. Broadband radiation modes: Estimation and active control

    NASA Astrophysics Data System (ADS)

    Berkhoff, Arthur P.

    2002-03-01

    In this paper we give a formulation of the most efficiently radiating vibration patterns of a vibrating body, the radiation modes, in the time domain. The radiation modes can be used to arrive at efficient weighting schemes for an array of sensors in order to reduce the controller dimensionality. Because these particular radiation modes are optimum in a broadband sense, they are termed broadband radiation modes. Methods are given to obtain these modes from measured data. The broadband radiation modes are used for the design of an actuator array in a feedback control system to reduce the sound power radiated from a plate. Three methods for the design of the actuator are compared, taking into account the reduction of radiated sound power in the controlled frequency range, but also the possible increase of radiated sound power in the uncontrolled frequency range.

  13. Measurement of 226Ra, 232Th, 137Cs and 40K activities of Wheat and Corn Products in Ilam Province – Iran and Resultant Annual Ingestion Radiation Dose

    PubMed Central

    CHANGIZI, Vahid; SHAFIEI, Elham; ZAREH, Mohammad Reza

    2013-01-01

    Background: Background: Natural background radiation is the main source of human exposure to radioactive material. Soils naturally have radioactive mineral contents. The aim of this study is to determine natural (238 U, 232 Th, 40 K) and artificial (137 Cs) radioactivity levels in wheat and corn fields of Eilam province. Methods: HPGe detector was used to measure the concentration activity of 238 U and 232 Th series, 40 K and 137 Cs in wheat and corn samples taken from different regions of Eilam province, in Iran. Results: In wheat and corn samples, the average activity concentrations of 226 Ra, 232 Th, 40 K and 137 Cs were found to be 1, 67, 0.5, 91.73, 0.01 and 0.81, 0.85, 101.52, 0.07 Bq/kg (dry weight), respectively. H ex and H in in the present work are lower than 1. The average value of H ex was found to be 0.02 and 0.025 and average value of H in to be found 0.025 and 0.027 in wheat fields samples and corn samples in Eilam provinces, respectively. The obtained values of AGDE are 30.49 mSv/yr for wheat filed samples and 37.89 mSv/yr for corn samples; the AEDE rate values are 5.28 mSv/yr in wheat filed samples and this average value was found to be 6.13 mSv/yr in corn samples in Eilam. Transfer factors (TFs) of long lived radionuclide such as 137 Cs, 226 Ra, 232 Th and 40 K from soils to corn and wheat plants have been studied by radiotracer experiments. Conclusion: The natural radioactivity levels in Eilam province are not at the range of high risk of morbidity and are under international standards. PMID:26056646

  14. Real time radiation measurements in space

    NASA Astrophysics Data System (ADS)

    Thomson, I.; Mackay, G.

    Radiation composed of energetic electrons, protons, photons, and galactic cosmic rays will be experienced by all space missions and may have effects on radiation sensitive electronic components and biological specimens. Radiation issues of interest to microgravity and biological experiments are discussed and the design of a new direct reading electronic radiation monitoring system is described. The proposed system consists of a radiation sensitive metal oxide semiconductor field effect transistor (MOSFET) specially designed to respond to ionizing radiation. On exposure to radiation, a permanent charge is stored in the MOSFET's insulating oxide, altering the device's electrical characteristics in a manner directly proportional to the dose exposed. A simple circuit reads the MOSFET's cumulative dose, making it possible to obtain real-time measurements and store the data or transfer the data to an earth station. Tests have shown that the MOSFET dosimeter shows a linear response up to at least 30,000 centiGray at a resolution of 0.1 centiGray. The MOSFET dosimetry system will be installed on the European Space Agency's ARTEP satellite scheduled for launch in November 1991.

  15. Sources and measurement of ultraviolet radiation.

    PubMed

    Diffey, Brian L

    2002-09-01

    Ultraviolet (UV) radiation is part of the electromagnetic spectrum. The biological effects of UV radiation vary enormously with wavelength and for this reason the UV spectrum is further subdivided into three regions: UVA, UVB, and UVC. Quantities of UV radiation are expressed using radiometric terminology. A particularly important term in clinical photobiology is the standard erythema dose (SED), which is a measure of the erythemal effectiveness of a UV exposure. UV radiation is produced either by heating a body to an incandescent temperature, as is the case with solar UV, or by passing an electric current through a gas, usually vaporized mercury. The latter process is the mechanism whereby UV radiation is produced artificially. Both the quality (spectrum) and quantity (intensity) of terrestrial UV radiation vary with factors including the elevation of the sun above the horizon and absorption and scattering by molecules in the atmosphere, notably ozone, and by clouds. For many experimental studies in photobiology it is simply not practicable to use natural sunlight and so artificial sources of UV radiation designed to simulate the UV component of sunlight are employed; these are based on either optically filtered xenon arc lamps or fluorescent lamps. The complete way to characterize an UV source is by spectroradiometry, although for most practical purposes a detector optically filtered to respond to a limited portion of the UV spectrum normally suffices.

  16. Sources and measurement of ultraviolet radiation.

    PubMed

    Diffey, Brian L

    2002-09-01

    Ultraviolet (UV) radiation is part of the electromagnetic spectrum. The biological effects of UV radiation vary enormously with wavelength and for this reason the UV spectrum is further subdivided into three regions: UVA, UVB, and UVC. Quantities of UV radiation are expressed using radiometric terminology. A particularly important term in clinical photobiology is the standard erythema dose (SED), which is a measure of the erythemal effectiveness of a UV exposure. UV radiation is produced either by heating a body to an incandescent temperature, as is the case with solar UV, or by passing an electric current through a gas, usually vaporized mercury. The latter process is the mechanism whereby UV radiation is produced artificially. Both the quality (spectrum) and quantity (intensity) of terrestrial UV radiation vary with factors including the elevation of the sun above the horizon and absorption and scattering by molecules in the atmosphere, notably ozone, and by clouds. For many experimental studies in photobiology it is simply not practicable to use natural sunlight and so artificial sources of UV radiation designed to simulate the UV component of sunlight are employed; these are based on either optically filtered xenon arc lamps or fluorescent lamps. The complete way to characterize an UV source is by spectroradiometry, although for most practical purposes a detector optically filtered to respond to a limited portion of the UV spectrum normally suffices. PMID:12231182

  17. Gamma radiation background measurements from Spacelab 2

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.; Gregory, John C.; Fishman, Gerald J.

    1988-01-01

    A Nuclear Radiation Monitor incorporating a NaI(Tl) scintillation detector was flown as part of the verification flight instrumentation on the Spacelab 2 mission, July 29 to August 6, 1985. Gamma-ray spectra were measured with better than 20 s resolution throughout most of the mission in the energy range 0.1 to 30 MeV. Knowledge of the decay characteristics and the geomagnetic dependence of the counting rates enable measurement of the various components of the Spacelab gamma-ray background: prompt secondary radiation, Earth albedo, and delayed induced radioactivity. The status of the data analysis and present relevant examples of typical background behavior are covered.

  18. Gamma radiation background measurements from Spacelab 2

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.; Gregory, John C.; Fishman, Gerald J.

    1989-01-01

    A Nuclear Radiation Monitor incorporating a NaI(Tl) scintillation detector was flown as part of the verification flight instrumentation on the Spacelab 2 mission, July 29 to August 6, 1985. Gamma-ray spectra were measured with better than 20 s resolution throughout most of the mission in the energy range 0.1 to 30 MeV. Knowledge of the decay characteristics and the geomagnetic dependence of the counting rates enable measurement of the various components of the Spacelab gamma-ray background: prompt secondary radiation, earth albedo, and delayed induced radioactivity. The status of the data analysis and present relevant examples of typical background behavior are covered.

  19. Measurement of Global Radiation using Photovoltaic Panels

    NASA Astrophysics Data System (ADS)

    Veroustraete, Frank; Bronders, Jan; Lefevre, Filip; Mensink, Clemens

    2014-05-01

    The Vito Unit - Environmental and Spatial Aspects (RMA) - for many of its models makes use of global solar radiation. From this viewpoint and also from the notion that this variable is seldom measured or available at the local scale and at high multi-temporal frequencies, it can be stated that many models are fed with low quality estimates of global solar radiation at the local to regional scales. A project was initiated called SUNSPIDER with the following objective. To make use of photovoltaic solar panels to measure solar radiation at the highest spatio-temporal resolution, from the local to the regional scales and from minutes to years. To integrate the measured solar fields in different application fields like, plant systems and agriculture, agro-meteorology and hydrology and last but not least solar energy applications. In Belgium about 250.000 PV installations have been built leading to about 6% electric power supply from photovoltaics on a yearly basis. Last year in June, the supply reached a peak of more than 20% of the total power input on the Belgian grid. A database of Belgian residential solar panel sites will be compiled. The database will serve as an input to an inverted PV model to be able to perform radiation calculations specifically for each of the validated panel sites based on minutely logged power data. Data acquisition for these sites will start each time a site is validated and hence imported in the database. Keywords: Photovoltaic Panels; PV modelling; Global Radiation.

  20. Radiation measurements from polar and geosynchronous satellites

    NASA Technical Reports Server (NTRS)

    Vonderhaar, T. H.

    1973-01-01

    During the 1960's, radiation budget measurements from satellites have allowed quantitative study of the global energetics of our atmosphere-ocean system. A continuing program is planned, including independent measurement of the solar constant. Thus far, the measurements returned from two basically different types of satellite experiments are in agreement on the long term global scales where they are most comparable. This fact, together with independent estimates of the accuracy of measurement from each system, shows that the energy exchange between earth and space is now measured better than it can be calculated. Examples of application of the radiation budget data were shown. They can be related to the age-old problem of climate change, to the basic question of the thermal forcing of our circulation systems, and to the contemporary problems of local area energetics and computer modeling of the atmosphere.

  1. Wedge immersed thermistor bolometer measures infrared radiation

    NASA Technical Reports Server (NTRS)

    Dreyfus, M. G.

    1965-01-01

    Wedge immersed-thermistor bolometer measures infrared radiation in the atmosphere. The thermistor flakes are immersed by optical contact on a wedge-shaped germanium lens whose narrow dimension is clamped between two complementary wedge-shaped germanium blocks bonded with a suitable adhesive.

  2. Symposium on Radiation Measurements and Applications

    NASA Astrophysics Data System (ADS)

    Wehe, David K.

    2015-06-01

    On June 9-12, 2014, the Symposium on Radiation Measurements and Applications (SORMA XV) took place at the University of Michigan campus. This was the 15th in the long-running series traditionally held every four years in Ann Arbor, and marked its 50th anniversary since inception. Attendance peaked again at nearly 500 conferees, with 135 students in attendance.

  3. Radiation measurements on the International Space Station.

    PubMed

    Badhwar, G D

    2001-01-01

    The International Space Station (ISS) is becoming a reality with the docking of the Russian Service module (Zarya) with the Unity module (Zaveda). ISS will be in a nominal 51.65-degree inclination by 400 km orbit. This paper reviews the currently planned radiation measurements, which are in many instances, based on experiments previously flown on the Space Shuttle. Results to be expected based on Shuttle measurements are presented.

  4. METHOD AND APPARATUS FOR MEASURING RADIATION

    DOEpatents

    Reeder, S.D.

    1962-04-17

    A chemical dosimeter for measuring the progress of a radiation-induced oxidation-reduction reaction is described. The dosimeter comprises a container filled with an aqueous chemical oxidation-reduction system which reacts quantitatively to the radiation. An anode of the group consisting of antimony and tungsten and a cathode of the group consisting of gold and platnium are inserted into the system. Means are provided to stir the system and a potential sensing device is connected across the anode and cathode to detect voltage changes. (AEC)

  5. Preliminary results of radiation measurements on EURECA

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    The eleven-month duration of the EURECA mission allows long term radiation effects to be studied similarly to those of the Long Duration Exposure Facility (LDEF). Basic data can be generated for projections of crew doses and electronic and computer reliability on spacecraft missions. A radiation experiment has been designed for EURECA which uses passive integrating detectors to measure average radiation levels. The components include a Trackoscope, which employs fourteen plastic nuclear track detector (PNTD) stacks to measure the angular dependence of LET (greater than or equal to 6 keV/microns) radiation. Also included are TLD's for total absorbed doses, thermal/resonance neutron detectors (TRND's) for low energy neutron fluences and a thick PNTD stack for depth dependence measurements. LET spectra are derived from the PNTD measurements. Preliminary TLD results from seven levels within the detector array show that integrated doses inside the flight canister varied from 18.8 plus or minus 0.6 cGy to 38.9 plus or minus 1.2 cGy. The TLD's oriented toward the least shielded direction averaged 53 percent higher in dose than those oriented away from the least shielded direction (minimum shielding toward the least shielded direction varied from 1.13 to 7.9 g/cm(exp 2), Al equivalent). The maximum dose rate on EURECA (1.16 mGy/day) was 37 percent of the maximum measured on LDEF and dose rates at all depths were less than measured on LDEF. The shielding external to the flight canister covered a greater solid angle about the canister than in the LDEF experiments.

  6. Preliminary results of radiation measurements on EURECA

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    The eleven-month duration of the EURECA mission allows long-term radiation effects to be studied similarly to those of the Long Duration Exposure Facility (LDEF). Basic data can be generated for projections to crew doses and electronic and computer reliability on spacecraft missions. A radiation experiment has been designed for EURECA which uses passive integrating detectors to measure average radiation levels. The components include a Trackoscope, which employs fourteen plastic nuclear track detector (PNTD) stacks to measure the angular dependence of high LET (greater than or equal to 6 keV/micro m) radiation. Also included are TLD's for total absorbed doses, thermal/resonance neutron detectors (TRND's) for low energy neutron fluences and a thick PNTD stack for depth dependence measurements. LET spectra are derived from the PNTD measurements. Preliminary TLD results from seven levels within the detector array show that integrated does inside the flight canister varied from 18.8 +/- 0.6 cGy to 38.9 +/- 1.2 cGy. The TLD's oriented toward the least shielded direction averaged 53% higher in dose than those oriented away from the least shielded direction (minimum shielding toward the least shielded direction varied from 1.13 to 7.9 g/cm(exp 2), Al equivalent). The maximum dose rate on EURECA (1.16 mGy/day) was 37% of the maximum measured on LDEF and dose rates at all depths were less than measured on LDEF. The shielding external to the flight canister covered a greater solid angle about the canister than the LDEF experiments.

  7. Measuring Acoustic-Radiation Stresses in Materials

    NASA Technical Reports Server (NTRS)

    Cantrell, John H.; Yost, W. T.

    1986-01-01

    System measures nonlinearity parameters of materials. Uses static strain generated by acoustic wave propagating in material. Since static strain is effectively "dc" component of waveform distortion, problems associated with phase-cancellation artifacts disappear. Further, sign of nonlinearity parameter obtained by simple inspection of measured signal polarity. These features make this system very amenable to use in field. System expected to become standard for acoustic-radiation-stress measurements for solids and liquids and for characterization of material properties related to strength and residual or applied stresses. Also expected to become standard for transducer calibration.

  8. Radiation beam calorimetric power measurement system

    DOEpatents

    Baker, John; Collins, Leland F.; Kuklo, Thomas C.; Micali, James V.

    1992-01-01

    A radiation beam calorimetric power measurement system for measuring the average power of a beam such as a laser beam, including a calorimeter configured to operate over a wide range of coolant flow rates and being cooled by continuously flowing coolant for absorbing light from a laser beam to convert the laser beam energy into heat. The system further includes a flow meter for measuring the coolant flow in the calorimeter and a pair of thermistors for measuring the temperature difference between the coolant inputs and outputs to the calorimeter. The system also includes a microprocessor for processing the measured coolant flow rate and the measured temperature difference to determine the average power of the laser beam.

  9. Automatic actinometric system for diffuse radiation measurement

    NASA Astrophysics Data System (ADS)

    Litwiniuk, Agnieszka; Zajkowski, Maciej

    2015-09-01

    Actinometric station is using for measuring solar of radiation. The results are helpful in determining the optimal position of solar panels relative to the Sun, especially in today's world, when the energy coming from the Sun and other alternative sources of energy become more and more popular. Polish climate does not provide as much energy as in countries in southern Europe, but it is possible to increase the amount of energy produced by appropriate arrangement of photovoltaic panels. There is the possibility of forecasting the amount of produced energy, the cost-effectiveness and profitability of photovoltaic installations. This implies considerable development opportunities for domestic photovoltaic power plants. This article presents description of actinometric system for diffuse radiation measurement, which is equipped with pyranometer - thermopile temperature sensor, amplifier AD620, AD Converter ADS1110, microcontroller Atmega 16, SD card, GPS module and LCD screen.

  10. Measurements of the cosmic background radiation

    NASA Technical Reports Server (NTRS)

    Lubin, P.; Villela, T.

    1986-01-01

    Data on the cosmic microwave background radiation obtained with a maser at 12 mm and a Schottky diode mixer at 3 mm are presented. The dipole anisotropy, apparently due to our motion, has been measured sufficiently well to determine our direction of motion within two degrees. The results show that the Galaxy is moving in a direction that is about 44 deg from the center of the Virgo cluster.

  11. Comparative Measurements of Radon Concentration in Soil Using Passive and Active Methods in High Level Natural Radiation Area (HLNRA) of Ramsar

    PubMed Central

    Amanat, B; Kardan, M R; Faghihi, R; Hosseini Pooya, S M

    2013-01-01

    Background: Radon and its daughters are amongst the most important sources of natural exposure in the world. Soil is one of the significant sources of radon/thoron due to both radium and thorium so that the emanated thoron from it may cause increased uncertainties in radon measurements. Recently, a diffusion chamber has been designed and optimized for passive discriminative measurements of radon/thoron concentrations in soil. Objective: In order to evaluate the capability of the passive method, some comparative measurements (with active methods) have been performed. Method: The method is based upon measurements by a diffusion chamber, including two Lexan polycarbonate SSNTDs, which can discriminate the emanated radon/thorn from the soil by delay method. The comparative measurements have been done in ten selected points of HLNRA of Ramsar in Iran. The linear regression and correlation between the results of two methods have been studied. Results: The results show that the radon concentrations are within the range of 12.1 to 165 kBq/m3 values. The correlation between the results of active and passive methods was measured by 0.99 value. As well, the thoron concentrations have been measured between 1.9 to 29.5 kBq/m3 values at the points. Conclusion: The sensitivity as well as the strong correlation with active measurements shows that the new low-cost passive method is appropriate for accurate seasonal measurements of radon and thoron concentration in soil. PMID:25505760

  12. Measurements of neutron radiation in aircraft.

    PubMed

    Vuković, B; Poje, M; Varga, M; Radolić, V; Miklavcić, I; Faj, D; Stanić, D; Planinić, J

    2010-12-01

    Radiation environment is a complex mixture of charged particles of the solar and galactic origin, as well as of secondary particles created in an interaction of galactic cosmic particles with the nuclei of the Earth's atmosphere. A radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. In order to measure a neutron component of the cosmic radiation, we investigated a few combinations of a track etch detector (CR-39, LR-115) with a plastic converter or boron foil. Detector calibration was performed on neutrons coming from the nuclear reactor, as well as in the CERN-EU high-energy Reference Field (CERF) facility. From November 2007 to September 2008, the neutron dose equivalent was measured by the track detectors during five aircraft flights, in the north geographical latitude from 21° to 58°; the respective average dose rate, determined by using the D-4 detector (CR-39/B), was Ḣ(n)=5.9 μSv/h. The photon dose rate, measured by the electronic dosimeter RAD-60 SE, had the average value of Ḣ(f)=1.4 μSv/h.

  13. Radiation measurements on the Mir Orbital Station.

    PubMed

    Badhwar, G D; Atwell, W; Reitz, G; Beaujean, R; Heinrich, W

    2002-10-01

    Radiation measurements made onboard the MIR Orbital Station have spanned nearly a decade and covered two solar cycles, including one of the largest solar particle events, one of the largest magnetic storms, and a mean solar radio flux level reaching 250 x 10(4) Jansky that has been observed in the last 40 years. The cosmonaut absorbed dose rates varied from about 450 microGy day-1 during solar minimum to approximately half this value during the last solar maximum. There is a factor of about two in dose rate within a given module, and a similar variation from module to module. The average radiation quality factor during solar minimum, using the ICRP-26 definition, was about 2.4. The drift of the South Atlantic Anomaly was measured to be 6.0 +/- 0.5 degrees W, and 1.6 +/- 0.5 degrees N. These measurements are of direct applicability to the International Space Station. This paper represents a comprehensive review of Mir Space Station radiation data available from a variety of sources. PMID:12440430

  14. Radiation measurements on the Mir Orbital Station.

    PubMed

    Badhwar, G D; Atwell, W; Reitz, G; Beaujean, R; Heinrich, W

    2002-10-01

    Radiation measurements made onboard the MIR Orbital Station have spanned nearly a decade and covered two solar cycles, including one of the largest solar particle events, one of the largest magnetic storms, and a mean solar radio flux level reaching 250 x 10(4) Jansky that has been observed in the last 40 years. The cosmonaut absorbed dose rates varied from about 450 microGy day-1 during solar minimum to approximately half this value during the last solar maximum. There is a factor of about two in dose rate within a given module, and a similar variation from module to module. The average radiation quality factor during solar minimum, using the ICRP-26 definition, was about 2.4. The drift of the South Atlantic Anomaly was measured to be 6.0 +/- 0.5 degrees W, and 1.6 +/- 0.5 degrees N. These measurements are of direct applicability to the International Space Station. This paper represents a comprehensive review of Mir Space Station radiation data available from a variety of sources.

  15. Radiation Transmission Measurements for Demron Fabric

    SciTech Connect

    Friedman, H; Singh, M S

    2003-01-07

    Radiation Shield Technologies has requested a measurement survey of its Demron fabric to determine the shielding properties in the x-ray, gamma ray and beta particle emissions in the range of energies relevant to clinical and Homeland Security applications. It is important to perform a detailed measurement program in order to sort out the shielding properties of this material in light of the often-times complex spectra emitted by standard radio-nuclides and x-ray generators. Low energy portions of the spectra are shielded more easily by this fabric than are the higher energy components and a simple single-layer test can lead to misleading results. This concept of ''spectral hardening'' was investigated by measuring the transmission factors for many layers and extracting information from the slopes of the transmission curves thereby obtaining a true picture of the shielding properties of the material as a function of energy. After the initial measurement program was completed, the mass attenuation coefficients were calculated using the LLNL cross section data, TART code, RST supplied weight fractions and the measured density of the fabric. This code is used for the Monte Carlo simulation of coupled neutron-photon transport in 3-D geometry for shielding and other applications. With such a design tool, it is possible to ''tune'' the characteristics of the Demron fabric to meet the specific needs for a given radiation environment.

  16. Miniature detector measures deep space radiation

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2011-08-01

    The 1972 journey of Apollo 17 marked not only the last time a human walked on the Moon but also the most recent manned venture beyond the outer reaches of the Earth's atmosphere. With preparations being made for humans to once again explore deep space, important steps are under way to quantify the hazards of leaving low-Earth orbit. One significant risk for long-distance missions is the increased exposure to ionizing radiation—energetic particles that can strip electrons off of otherwise neutral materials, affecting human health and the functioning of spacecraft equipment. The deep space probes that are being sent to measure the risks from ionizing radiation and other hazards can be costly, so maximizing the scientific value of each launch is important. With this goal in mind, Mazur et al. designed and developed a miniature dosimeter that was sent into lunar orbit aboard NASA's Lunar Reconnaissance Orbiter (LRO) in 2009. Weighing only 20 grams, the detector is able to measure fluctuations in ionizing radiation as low as 1 microrad (equivalent to 1.0 × 10-8 joules of energy deposited into 1 kilogram) while requiring minimal power and computer processing. The postage stamp-sized detector tracked radiation dosages for the first year of LRO's mission, with the results being confirmed by other onboard and near-Earth detectors. (Space Weather, doi:10.1029/2010SW000641, 2011)

  17. Measuring ionizing radiation with a mobile device

    NASA Astrophysics Data System (ADS)

    Michelsburg, Matthias; Fehrenbach, Thomas; Puente León, Fernando

    2012-02-01

    In cases of nuclear disasters it is desirable to know one's personal exposure to radioactivity and the related health risk. Usually, Geiger-Mueller tubes are used to assess the situation. Equipping everyone with such a device in a short period of time is very expensive. We propose a method to detect ionizing radiation using the integrated camera of a mobile consumer device, e.g., a cell phone. In emergency cases, millions of existing mobile devices could then be used to monitor the exposure of its owners. In combination with internet access and GPS, measured data can be collected by a central server to get an overview of the situation. During a measurement, the CMOS sensor of a mobile device is shielded from surrounding light by an attachment in front of the lens or an internal shutter. The high-energy radiation produces free electrons on the sensor chip resulting in an image signal. By image analysis by means of the mobile device, signal components due to incident ionizing radiation are separated from the sensor noise. With radioactive sources present significant increases in detected pixels can be seen. Furthermore, the cell phone application can make a preliminary estimate on the collected dose of an individual and the associated health risks.

  18. Future radiation measurements in low Earth orbit

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.

    1993-01-01

    The first Long Duration Exposure Facility (LDEF) mission has demonstrated the value of the LDEF concept for deep surveys of the space radiation environment. The kinds of measurements that could be done on a second LDEF mission are discussed. Ideas are discussed for experiments which: (1) capitalize on the discoveries from LDEF 1; (2) take advantage of LDEF's unique capabilities; and (3) extend the investigations begun on LDEF 1. These ideas have been gleaned from investigators on LDEF 1 and others interested in the space radiation environment. They include new approaches to the investigation of Be-7 that was discovered on LDEF 1, concepts to obtain further information on the ionic charge state of cosmic rays and other energetic particles in space and other ideas to extend the investigations begun on LDEF 1.

  19. Measurement of Thermal Radiation Properties of Solids

    NASA Technical Reports Server (NTRS)

    Richmond, J. C. (Editor)

    1963-01-01

    The overall objectives of the Symposium were to afford (1) an opportunity for workers in the field to describe the equipment and procedures currently in use for measuring thermal radiation properties of solids, (2) an opportunity for constructive criticism of the material presented, and (3) an open forum for discussion of mutual problems. It was also the hope of the sponsors that the published proceedings of the Symposium would serve as a valuable reference on measurement techniques for evaluating thermal radiation properties of solids, partic.ularly for those with limited experience in the field. Because of the strong dependence of emitted flux upon temperature, the program committee thought it advisable to devote the first session to a discussion of the problems of temperature measurement. All of the papers in Session I were presented at the request of and upon topics suggested by the Committee. Because of time and space limitations, it, was impossible to consider all temperature measurement problems that might arise--the objective was rather to call to the attention of the reader some of the problems that might be encountered, and to provide references that might provide solutions.

  20. Radiated microwave power transmission system efficiency measurements

    NASA Technical Reports Server (NTRS)

    Dickinson, R. M.; Brown, W. C.

    1975-01-01

    The measured and calculated results from determining the operating efficiencies of a laboratory version of a system for transporting electric power from one point to another via a wireless free space radiated microwave beam are reported. The system's overall end-to-end efficiency as well as intermediated conversion efficiencies were measured. The maximum achieved end-to-end dc-to-ac system efficiency was 54.18% with a probable error of + or - 0.94%. The dc-to-RF conversion efficiency was measured to be 68.87% + or - 1.0% and the RF-to-dc conversion efficiency was 78.67 + or - 1.1%. Under these conditions a dc power of 495.62 + or - 3.57 W was received with a free space transmitter antenna receiver antenna separation of 170.2 cm (67 in).

  1. Active Radiation Monitoring on the International Space Station

    NASA Astrophysics Data System (ADS)

    Shelfer, T.; Semones, E.; Johnson, S.; Zapp, N.; Weyland, M.; Riman, F.; Flanders, J.; Golightly, M.; Smith, G.

    The space radiation environment in and around the International Space Station (ISS) is currently being monitored by a variety of active and passive radiation measurement systems. There are currently three permanent NASA active radiation monitoring systems onboard the ISS. The first instrument is the ISS Tissue Equivalent Proportional Counter (ISS TEPC) that was activated November 9, 2000. The next instrument brought online was the Intra-Vehicular Charged Particle Directional Spectrometer (IV-CPDS) that was activated April 21, 2001. The last instrument to be activated was the Extra-Vehicular Charged Particle Directional Spectrometer (EV-CPDS) that was turned on April 26, 2002. These three instruments provide the Space Radiation Analysis Group at NASA/Johnson Space Center with real-time radiation environment data, as well as detailed science data that is downloaded on a regular basis. The real-time data is used primarily for flight operations support in the Mission Control Center - Houston. The detailed science data is currently used in support of crew radiation dosemetry efforts, to validate the radiation environment model at the ISS orbit, and to validate shield distribution and interaction models for the ISS. We plan to present data collected by the ISS TEPC, IV-CPDS, and EV-CPDS for the Expedition 3 (August 10, 2001 - December 17, 2001) and Expedition 4 (December 5, 2001 - June 11, 2002)) time periods. Our preliminary measurement results will be presented in terms of environment variables such as orbital altitude and space weather, and shielding variables such as location inside the ISS and orientation of the ISS complex. In addition, the measured radiation dose will be divided into contributions from Galactic Cosmic Rays (GCR) and trapped particles.

  2. Radiated BPF sound measurement of centrifugal compressor

    NASA Astrophysics Data System (ADS)

    Ohuchida, S.; Tanaka, K.

    2013-12-01

    A technique to measure radiated BPF sound from an automotive turbocharger compressor impeller is proposed in this paper. Where there are high-level background noises in the measurement environment, it is difficult to discriminate the target component from the background. Since the effort of measuring BPF sound was taken in a room with such condition in this study, no discrete BPF peak was initially found on the sound spectrum. Taking its directionality into consideration, a microphone covered with a parabolic cone was selected and using this technique, the discrete peak of BPF was clearly observed. Since the level of measured sound was amplified due to the area-integration effect, correction was needed to obtain the real level. To do so, sound measurements with and without a parabolic cone were conducted for the fixed source and their level differences were used as correction factors. Consideration is given to the sound propagation mechanism utilizing measured BPF as well as the result of a simple model experiment. The present method is generally applicable to sound measurements conducted with a high level of background noise.

  3. Measurement of enzyme activity.

    PubMed

    Harris, T K; Keshwani, M M

    2009-01-01

    To study and understand the nature of living cells, scientists have continually employed traditional biochemical techniques aimed to fractionate and characterize a designated network of macromolecular components required to carry out a particular cellular function. At the most rudimentary level, cellular functions ultimately entail rapid chemical transformations that otherwise would not occur in the physiological environment of the cell. The term enzyme is used to singularly designate a macromolecular gene product that specifically and greatly enhances the rate of a chemical transformation. Purification and characterization of individual and collective groups of enzymes has been and will remain essential toward advancement of the molecular biological sciences; and developing and utilizing enzyme reaction assays is central to this mission. First, basic kinetic principles are described for understanding chemical reaction rates and the catalytic effects of enzymes on such rates. Then, a number of methods are described for measuring enzyme-catalyzed reaction rates, which mainly differ with regard to techniques used to detect and quantify concentration changes of given reactants or products. Finally, short commentary is given toward formulation of reaction mixtures used to measure enzyme activity. Whereas a comprehensive treatment of enzymatic reaction assays is not within the scope of this chapter, the very core principles that are presented should enable new researchers to better understand the logic and utility of any given enzymatic assay that becomes of interest.

  4. Measurement of surface physical properties and radiation balance for KUREX-91 study

    NASA Technical Reports Server (NTRS)

    Walter-Shea, Elizabeth A.; Blad, Blaine L.; Mesarch, Mark A.; Hays, Cynthia J.

    1992-01-01

    Biophysical properties and radiation balance components were measured at the Streletskaya Steppe Reserve of the Russian Republic in July 1991. Steppe vegetation parameters characterized include leaf area index (LAI), leaf angle distribution, mean tilt angle, canopy height, leaf spectral properties, leaf water potential, fraction of absorbed photosynthetically active radiation (APAR), and incoming and outgoing shortwave and longwave radiation. Research results, biophysical parameters, radiation balance estimates, and sun-view geometry effects on estimating APAR are discussed. Incoming and outgoing radiation streams are estimated using bidirectional spectral reflectances and bidirectional thermal emittances. Good agreement between measured and modeled estimates of the radiation balance were obtained.

  5. Measuring space radiation with ADIS instruments

    NASA Astrophysics Data System (ADS)

    Connell, J. J.; Lopate, C.; McKibben, R. B.; Merk, J.

    2010-09-01

    Measurements of radiation in space, cosmic rays and Solar energetic particles, date back to the dawn of space flight. Solid state detectors, the basis of most modern high energy charged particle instruments, first flew in space in the 1960's. Modern particle spectrometers, such as ACE/CRIS, ACE/SIS and Ulysses/HET, can measure the elemental and isotopic composition of ions through the iron peak. This is achieved by using position sensing detectors (PSD's) arranged into hodoscopes to measure particle trajectories through the instrument, allowing for pathlength corrections to energy loss measurements. The Angle Detecting Inclined Sensor (ADIS) technique measures particle angle of incidence using a simple system of detectors inclined to the instrument axis. It achieves elemental resolution well beyond iron, and isotopic resolution for moderate mass elements without the complexity of position sensing detectors. An ADIS instrument was selected to fly as the High Energy Particle Sensor (HEPS) on NPOESS, but was de-scoped with the rest of the space weather suite. Another ADIS instrument, the Energetic Heavy Ion Sensor (EHIS), is being developed for GOES-R. UNH has built and tested a engineering unit of the EHIS. Applications for manned dosimetery on the Crew Exploration Vehicle (CEV) are also being explored. The basic ADIS technique is explained and accelerator data for heavy ions shown.

  6. Measurement and assessment of radiation dose of astronauts in space

    NASA Astrophysics Data System (ADS)

    Zhang, Binquan; Sun, Yue-qiang; Yang, Chuibai; Zhang, Shenyi; Liang, Jinbao

    Astronauts in flight are exposed by the space radiation, which is mainly composed of proton, electron, heavy ion, and neutron. To assess the radiation risk, measurement and assessment of radiation dose of astronauts is indispensable. Especially, measurement for heavy ion radiation is most important as it contributes the major dose. Until now, most of the measurements and assessments of radiation dose of astronauts are based on the LET (Linear Energy Transfer) spectrum of space radiation. However, according to the ICRP Publication 123, energy and charge number of heavy ions should be measured in order to assess space radiation exposure to astronauts. In addition, from the publication, quality factors for each organs or tissues of astronauts are different and they should be calculated or measured independently. Here, a method to measure the energy and charge number of heavy ion and a voxel phantom based on the anatomy of Chinese adult male are presented for radiation dose assessment of astronauts.

  7. Estimating shortwave solar radiation using net radiation and meteorological measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shortwave radiation has a wide variety of uses in land-atmosphere interactions research. Actual evapotranspiration estimation that involves stomatal conductance models like Jarvis and Ball-Berry require shortwave radiation to estimate photon flux density. However, in most weather stations, shortwave...

  8. Radiation Measurements on the Russian MIR Orbital Station

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.

    1999-01-01

    The Russian Mir orbital station was launched into an orbit with a 51.65 deg inclination in March 1986. It has operated continuously in the altitude range of 380 to 460 km. Almost immediately, cosmonauts began to carry out missions to the station. To date, there have been some 25 Russian missions. As part of the NASA Mir Program, a comprehensive set of radiation measurements were made to map the radiation in all of the Mir module. Numerous radiation measurements have been made on the Mir station throughout its lifetime. However, the comparison of these measurements have been difficult because of different sensitivities of detectors, some active and some passive, differing self shielding and in most cases unknown location shielding. In spite of these complications, very significant progress in the knowledge of the radiation environment onboard the Mir station has been made. These results are directly applicable to expected radiation environment on the International Space Station. In this paper, we describe the combined results from all seven NASA Mir missions. We show: (1) the absorbed dose rate from trapped particles is well correlated with the atmospheric density computed nearly 400 days earlier than the time of observation, (2) developed a relationship between the absorbed dose rate from galactic cosmic rays to the deceleration potential derived using the Climax neutron monitor rate, giving a tool to predict GCR dose rates to +/- 15% nearly 90 days prior to observations, (3) describe the drift of the South Atlantic Anomaly (SAA) with time, (4) compare the predictions of the dose rates as a function of time from the November 6-8, 1998 solar particle event with observations, (5) compare measurements made with NASA Tissue Equivalent Proportional Counter (TEPC) with the ESA DOSTEL device, the Hungarian Pille system, and the Russian R-16 dosimeter. Implications of these measurements for the ISS will be discussed.

  9. Measurement of Physical Activity.

    ERIC Educational Resources Information Center

    Dishman, Rod K.; Washburn, Richard A.; Schoeller, Dale A.

    2001-01-01

    Valid assessment of physical activity must be unobtrusive, practical to administer, and specific about physical activity type, frequency, duration, and intensity. Assessment methods can be categorized according to whether they provide direct or indirect (e.g., self-report) observation of physical activity, body motion, physiological response…

  10. European activities in radiation protection in medicine.

    PubMed

    Simeonov, Georgi

    2015-07-01

    The recently published Council Directive 2013/59/Euratom ('new European Basic Safety Standards', EU BSS) modernises and consolidates the European radiation protection legislation by taking into account the latest scientific knowledge, technological progress and experience with implementing the current legislation and by merging five existing Directives into a single piece of legislation. The new European BSS repeal previous European legislation on which the national systems for radiation protection in medicine of the 28 European Union (EU) Member States are based, including the 96/29/Euratom 'BSS' and the 97/43/Euratom 'Medical Exposure' Directives. While most of the elements of the previous legislation have been kept, there are several legal changes that will have important influence over the regulation and practice in the field all over Europe-these include, among others: (i) strengthening the implementation of the justification principle and expanding it to medically exposed asymptomatic individuals, (ii) more attention to interventional radiology, (iii) new requirements for dose recording and reporting, (iv) increased role of the medical physics expert in imaging, (v) new set of requirements for preventing and following up on accidents and (vi) new set of requirements for procedures where radiological equipment is used on people for non-medical purposes (non-medical imaging exposure). The EU Member States have to enforce the new EU BSS before January 2018 and bring into force the laws, regulations and administrative provisions necessary to comply with it. The European Commission has certain legal obligations and powers to verify the compliance of the national measures with the EU laws and, wherever necessary, issue recommendations to, or open infringement cases against, national governments. In order to ensure timely and coordinated implementation of the new European legal requirements for radiation protection, the Commission is launching several actions

  11. Measurement of solar radiation at the Earth's surface

    NASA Technical Reports Server (NTRS)

    Bartman, F. L.

    1982-01-01

    The characteristics of solar energy arriving at the surface of the Earth are defined and the history of solar measurements in the United States presented. Radiation and meteorological measurements being made at solar energy meteorological research and training sites and calibration procedures used there are outlined. Data illustrating the annual variation in daily solar radiation at Ann Arbor, Michigan and the diurnal variation in radiation at Albuquerque, New Mexico are presented. Direct normal solar radiation received at Albuquerque is contrasted with that received at Maynard, Massachusetts. Average measured global radiation for a period of one year for four locations under clear skies, 50% cloud cover, and 100% cloud cover is given and compared with the solar radiation at the top of the atmosphere. The May distribution of mean daily direct solar radiation and mean daily global solar radiation over the United States is presented. The effects of turbidity on the direct and circumsolar radiation are shown.

  12. Method and apparatus for measuring electromagnetic radiation

    NASA Technical Reports Server (NTRS)

    Been, J. F. (Inventor)

    1973-01-01

    An apparatus and method are described in which the capacitance of a semiconductor junction subjected to an electromagnetic radiation field is utilized to indicate the intensity or strength of the radiation.

  13. Radiation measurement on the International Space Station.

    PubMed

    Akopova, A B; Manaseryan, M M; Melkonyan, A A; Tatikyan, S Sh; Potapov, Yu

    2005-02-01

    The results of an investigation of radiation environment on board the ISS with apogee/perigee of 420/380 km and inclination 51.6 degrees are presented. For measurement of important characteristics of cosmic rays (particles fluxes, LET spectrum, equivalent doses and heavy ions with Z > or = 2) a nuclear photographic emulsion as a controllable threshold detector was used. The use of this detector permits a registration of the LET spectrum of charged particles within wide range of dE/dx and during the last years it has already been successfully used on board the MIR station, Space Shuttles and "Kosmos" spacecrafts. An integral LET spectrum was measured in the range 0.5-2.2 x 10(3) keV/micrometers and the value of equivalent dose 360 microSv/day was estimated. The flux of biologically dangerous heavy particles with Z > or = 2 was measured (3.85 x 10(3) particles/cm2).

  14. Ground truth data for test sites (SL-3). [solar radiation and thermal radiation brightness temperature measurements

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Field measurements performed simultaneously with Skylab overpasses in order to provide comparative calibration and performance evaluation measurements for the EREP sensors are presented. The solar radiation region from 400 to 1300 nanometers and the thermal radiation region from 8 to 14 micrometer region were investigated. The measurements of direct solar radiation were analyzed for atmospheric optical depth; the total and reflected solar radiation were analyzed for target reflectivity. These analyses were used in conjunction with a radiative transfer computer program in order to calculate the amount and spectral distribution of solar radiation at the apertures of the EREP sensors. The instrumentation and techniques employed, calibrations and analyses performed, and results obtained are discussed.

  15. Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models

    SciTech Connect

    Patrinos, A.A. ); Renne, D.S.; Stokes, G.M. ); Ellingson, R.G. )

    1991-01-01

    The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy's (DOE's) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and related models. The importance of the ARM program is a apparent from the results of model assessments of the impact on global climate change. Recent studies suggest that radiatively active trace gas emissions caused by human activity can lead to a global warming of 1.5 to 4.5 degrees Celsius and to important changes in water availability during the next century (Cess, et al. 1989). These broad-scale changes can be even more significant at regional levels, where large shifts in temperature and precipitation patterns are shown to occur. However, these analyses also indicate that considerable uncertainty exists in these estimates, with the manner in which cloud radiative processes are parameterized among the most significant uncertainty. Thus, although the findings have significant policy implications in assessment of global and regional climate change, their uncertainties greatly influence the policy debate. ARM's highly focused observational and analytical research is intended to accelerate improvements and reduce key uncertainties associated with the way in which GCMs treat cloud cover and cloud characteristics and the resulting radiative forcing. This paper summarizes the scientific context for ARM, ARM's experimental approach, and recent activities within the ARM program.

  16. Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models

    SciTech Connect

    Patrinos, A.A.; Renne, D.S.; Stokes, G.M.; Ellingson, R.G.

    1991-01-01

    The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy`s (DOE`s) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and related models. The importance of the ARM program is a apparent from the results of model assessments of the impact on global climate change. Recent studies suggest that radiatively active trace gas emissions caused by human activity can lead to a global warming of 1.5 to 4.5 degrees Celsius and to important changes in water availability during the next century (Cess, et al. 1989). These broad-scale changes can be even more significant at regional levels, where large shifts in temperature and precipitation patterns are shown to occur. However, these analyses also indicate that considerable uncertainty exists in these estimates, with the manner in which cloud radiative processes are parameterized among the most significant uncertainty. Thus, although the findings have significant policy implications in assessment of global and regional climate change, their uncertainties greatly influence the policy debate. ARM`s highly focused observational and analytical research is intended to accelerate improvements and reduce key uncertainties associated with the way in which GCMs treat cloud cover and cloud characteristics and the resulting radiative forcing. This paper summarizes the scientific context for ARM, ARM`s experimental approach, and recent activities within the ARM program.

  17. The measurement of radiation exposure of astronauts by radiochemical techniques

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.

    1972-01-01

    Cosmic radiation doses to the crews of the Apollo 14, 15, and 16 missions of 142 + or - 80, 340 + or - 80, and 210 + or - 130 mR respectively were calculated from the specific activities of Na-22 and Na-24 in the postflight urine specimens of the astronauts. The specific activity of Fe-59 was higher in the urine than in the feces of the Apollo 14 and 15 astronauts, and a possible explanation is given. The concentrations of K-40, K-42, Cr-51, Co-60, and Cs-137 in the urine are also reported for these astronauts. The radiation doses received by pilots and navigators flying high altitude missions during the solar flare of March 27 to 30, 1972 were calculated from the specific activity of Na-24 in their urine. These values are compared with the expected radiation dose calculated from the known shape and intensity of the proton spectrum and demonstrate the magnitude of atmospheric shielding. The concentrations of Na, K, Rb, Cs, Fe, Co, Ag, Zn, Hg, As, Sb, Se, and Br were measured in the urine specimens from the Apollo 14 and 15 astronauts by neutron activation analysis. The mercury and arsenic levels were much higher than expected.

  18. Background radiation measurements at high power research reactors

    SciTech Connect

    Ashenfelter, J.; Balantekin, B.; Baldenegro, C. X.; Band, H. R.; Barclay, G.; Bass, C. D.; Berish, D.; Bowden, N. S.; Bryan, C. D.; Cherwinka, J. J.; Chu, R.; Classen, T.; Davee, D.; Dean, D.; Deichert, G.; Dolinski, M. J.; Dolph, J.; Dwyer, D. A.; Fan, S.; Gaison, J. K.; Galindo-Uribarri, A.; Gilje, K.; Glenn, A.; Green, M.; Han, K.; Hans, S.; Heeger, K. M.; Heffroni, B.; Jaffe, D. E.; Kettell, S.; Langford, T. J.; Littlejohn, B. R.; Martinez, D.; McKeown, R. D.; Morrell, S.; Mueller, P. E.; Mumm, H. P.; Napolitano, J.; Norcini, D.; Pushin, D.; Romero, E.; Rosero, R.; Saldana, L.; Seilhan, B. S.; Sharma, R.; Stemen, N. T.; Surukuchi, P. T.; Thompson, S. J.; Varner, R. L.; Wang, W.; Watson, S. M.; White, B.; White, C.; Wilhelmi, J.; Williams, C.; Wise, T.; Yao, H.; Yeh, M.; Yen, Y. -R.; Zhang, C.; Zhang, X.

    2015-10-23

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including -ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. Furthermore, the general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  19. Background radiation measurements at high power research reactors

    SciTech Connect

    Ashenfelter, J.; Yeh, M.; Balantekin, B.; Baldenegro, C. X.; Band, H. R.; Barclay, G.; Bass, C. D.; Berish, D.; Bowden, N. S.; Bryan, C. D.; Cherwinka, J. J.; Chu, R.; Classen, T.; Davee, D.; Dean, D.; Deichert, G.; Dolinski, M. J.; Dolph, J.; Dwyer, D. A.; Fan, S.; Gaison, J. K.; Galindo-Uribarri, A.; Gilje, K.; Glenn, A.; Green, M.; Han, K.; Hans, S.; Heeger, K. M.; Heffron, B.; Jaffe, D. E.; Kettell, S.; Langford, T. J.; Littlejohn, B. R.; Martinez, D.; McKeown, R. D.; Morrell, S.; Mueller, P. E.; Mumm, H. P.; Napolitano, J.; Norcini, D.; Pushin, D.; Romero, E.; Rosero, R.; Saldana, L.; Seilhan, B. S.; Sharma, R.; Stemen, N. T.; Surukuchi, P. T.; Thompson, S. J.; Varner, R. L.; Wang, W.; Watson, S. M.; White, B.; White, C.; Wilhelmi, J.; Williams, C.; Wise, T.; Yao, H.; Yen, Y. -R.; Zhang, C.; Zhang, X.

    2015-10-23

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including γ-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. Furthermore, the general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

  20. Background radiation measurements at high power research reactors

    DOE PAGES

    Ashenfelter, J.; Balantekin, B.; Baldenegro, C. X.; Band, H. R.; Barclay, G.; Bass, C. D.; Berish, D.; Bowden, N. S.; Bryan, C. D.; Cherwinka, J. J.; et al

    2015-10-23

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including -ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the backgroundmore » fields encountered. Furthermore, the general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.« less

  1. Background radiation measurements at high power research reactors

    DOE PAGES

    Ashenfelter, J.; Yeh, M.; Balantekin, B.; Baldenegro, C. X.; Band, H. R.; Barclay, G.; Bass, C. D.; Berish, D.; Bowden, N. S.; Bryan, C. D.; et al

    2015-10-23

    Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including γ-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the backgroundmore » fields encountered. Furthermore, the general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.« less

  2. Space life sciences: radiation risk assessment and radiation measurements in low Earth orbit.

    PubMed

    2004-01-01

    The volume contains papers presented at COSPAR symposia in October 2002 about radiation risk assessment and radiation measurements in low Earth orbit. The risk assessment symposium brought together multidisciplinary expertise including physicists, biologists, and theoretical modelers. Topics included current knowledge about known and predicted radiation environments, radiation shielding, physics cross section models, improved ion beam transport codes, biological demonstrations of specific shielding materials and applications to a manned mission to Mars, advancements in biological measurement of radiation-induced protein expression profiles, and integration of physical and biological parameters to assess key elements of radiation risk. Papers from the radiation measurements in low Earth orbit symposium included data about dose, linear energy transfer spectra, and charge spectra from recent measurements on the International Space Station (ISS), comparison between calculations and measurements of dose distribution inside a human phantom and the neutron component inside the ISS; and reviews of trapped antiprotons and positrons inside the Earth's magnetosphere. PMID:15880912

  3. Radiative temperature measurements at Kupaianaha lava lake, Kilauea Volcano, Hawaii

    NASA Astrophysics Data System (ADS)

    Flynn, Luke P.; Mouginis-Mark, Peter J.; Gradie, Jonathan C.; Lucey, Paul G.

    1993-04-01

    The radiative temperature of the surface of Kupaianaha lava lake is computed using field spectroradiometer data. Observations were made during periods of active overturning. The lake surface exhibits three stages of activity. Magma fountaining and overturning events characterize stage 1, which exhibits the hottest crustal temperatures and the largest fractional hot areas. Rifting events between plates of crust mark stage 2; crustal temperatures in this stage are between 100 C and 340 C, and fractional hot areas are at least an order of magnitude smaller than those in stage 1. Stage 3 is characterized by quiescent periods when the lake is covered by a thick crust. This stage dominates the activity of the lake more than 90 percent of the time. The results of this study are relevant for satellite and airborne measurement of the thermal characteristics of active volcanoes, and indicate that the thermal output of a lava lake varies on a time scale of seconds to minutes.

  4. Proceedings of a Meeting on Traceability for Ionizing Radiation Measurements

    NASA Astrophysics Data System (ADS)

    Heaton, H. T., II

    1982-02-01

    General concepts for traceability were presented from several perspectives. The national standards for radiation dosimetry, radioactivity measurements, and neutron measurements were described. Specific programs for achieving traceability to the national standards for radiation measurements in medical, occupational, and environmental applications were summarized.

  5. New radiosonde techniques to measure radiation profiles through the atmosphere

    NASA Astrophysics Data System (ADS)

    Kräuchi, Andreas; Philipona, Rolf; Romanens, Gonzague; Levrat, Gilbert

    2013-04-01

    Solar and thermal radiation fluxes are usually measured at Earth's surface and at the top of the atmosphere. Here we show radiosonde techniques that allow measuring radiation flux profiles and the radiation budget from the Earth's surface to above 30 km in the stratosphere. During two-hour flights solar shortwave and thermal longwave irradiance, downward and upward, is measured with four individual sensors at one-second resolution, along with standard PTU radiosonde profiles. Daytime and nighttime shortwave and longwave radiation measurements, and 24 hours surface measurements, allow determining radiation budget- and total net radiation profiles through the atmosphere. We use a double balloon technique to prevent pendulum motion during the ascent and to keep the sonde as horizontal as possible. New techniques using auto controlled airplanes are now investigated to retrieve the sonde after release at a certain altitude and to land it if possible at the launch station.

  6. Analysis of radiation measurement data of the BUSS cask

    SciTech Connect

    Liu, Y.Y.; Tang, J.S.

    1995-12-31

    The Beneficial Uses Shipping System (BUSS) is a Type-B packaging developed for shipping nonfissile, special-form radioactive materials to facilities such as sewage, food, and medical-product irradiators. The primary purpose of the BUSS cask is to provide shielding and confinement, as well as impact, puncture, and thermal protection for its certified special-form contents under both normal transport and hypothetical accident conditions. A BUSS cask that contained 16 CsCl capsules (2.723 {times} 10{sup 4} TBq total activity) was recently subjected to radiation survey measurements at a Westinghouse Hanford facility, which provided data that could be used to validate computer codes. Two shielding analysis codes, MICROSHIELD (User`s Manual 1988) and SAS4 (Tan 1993), that are used at Argonne National Laboratory to evaluate the safety of packaging of radioactive materials during transportation, have been selected for analysis of radiation data obtained from the BUSS cask. MICROSHIELD, which performs only gamma radiation shielding calculation, is based on a point-kernel model with idealized geometry, whereas SAS4 is a control module in the SCALE code system (1995) that can perform three-dimensional Monte Carlo shielding calculation for photons and neutrons, with built-in procedures for cross-section data processing and automated variance reduction. The two codes differ in how they model the details of the physics of gamma photon attenuation in materials, and this difference is reflected in the associated engineering cost of the analysis. One purpose of the analysis presented in this paper, therefore, is to examine the effects of the major modeling assumptions in the two codes on calculated dose rates, and to use the measured dose rates for comparison. The focus in this paper is on analysis of radiation dose rates measured on the general body of the cask and away from penetrations.

  7. Global Aerosol Radiative Forcing using Satellite and Surface Measurements

    NASA Astrophysics Data System (ADS)

    Patadia, F.; Christopher, S. A.

    2007-12-01

    Over the industrial period, aerosols have increased due to human activities and their effects on climate are the largest source of uncertainty in the current IPCC estimates of global climate forcing due to human activities. Inhomogeneous distribution of aerosols in space and time poses a challenge in their characterization and requires global measurements to assess their effects and reduce the associated uncertainties. In this paper we use global measurements from both satellite and ground based observations for one year time period to estimate the shortwave aerosol radiative forcing (SWARF) at the top-of-atmosphere (TOA) and discuss the associated uncertainties. For this, aerosol properties (optical depth) derived from AErosol RObotic NETwork (AERONET), a federation of ground-based remote sensing instruments, are used in this paper in conjunction with measurements of the TOA shortwave flux from CERES instrument (onboard Terra satellite). High spectral and spatial resolution observations from Imager (MODIS) will be used to identify clear sky conditions within CERES foot print and GOCART results will also be used for separating aerosol types. Global aerosol forcing and corresponding radiative forcing efficiencies will be presented as a function of major aerosol types [including anthropogenic (sulfate, soot, black carbon) and natural (dust) aerosols], region and season. This study should serve as a useful constraint for both numerical modeling simulations and satellite based estimates of SWARF.

  8. Global Aerosol Radiative Forcing Using Satellite and Surface Measurements

    NASA Astrophysics Data System (ADS)

    Patadia, F.; Christopher, S. A.

    2008-05-01

    Over the industrial period, aerosols have increased due to human activities and their effects on climate are the largest source of uncertainty in the current IPCC estimates of global climate forcing due to human activities. Inhomogeneous distribution of aerosols in space and time poses a challenge in characterizing their properties and requires global measurements to assess their effects and reduce the associated uncertainties. In this paper we use global measurements from both satellite and ground based observations for one year time period to estimate the shortwave aerosol radiative forcing (SWARF) at the top-of-atmosphere (TOA) and discuss the associated uncertainties. For this, aerosol properties (optical depth) derived from AErosol RObotic NETwork (AERONET), a federation of ground-based remote sensing instruments, are used in this paper in conjunction with measurements of the TOA shortwave flux from CERES instrument (onboard Terra satellite). High spectral and spatial resolution observations from Imager (MODIS) is used to identify clear sky conditions within CERES foot print and GOCART results will also be used for separating aerosol types. Global aerosol forcing and corresponding radiative forcing efficiencies will be presented as a function of major aerosol types [including anthropogenic (sulfate, soot, black carbon) and natural (dust) aerosols], region and season. This study should serve as a useful constraint for both numerical modeling simulations and satellite based estimates of SWARF.

  9. Radiation Pressure Measurements on Micron-Size Individual Dust Grains

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Craven, P. D.; Spann, J. F.; Witherow, W. K.; West, E. A.; Gallagher, D. L.; Adrian, M. L.; Fishman, G. J.; Tankosic, D.; LeClair, A.

    2003-01-01

    Measurements of electromagnetic radiation pressure have been made on individual silica (SiO2) particles levitated in an electrodynamic balance. These measurements were made by inserting single charged particles of known diameter in the 0.2- to 6.82-micron range and irradiating them from above with laser radiation focused to beam widths of approximately 175- 400 microns at ambient pressures particle due to the radiation force is balanced by the electrostatic force indicated by the compensating dc potential applied to the balance electrodes, providing a direct measure of the radiation force on the levitated particle. Theoretical calculations of the radiation pressure with a least-squares fit to the measured data yield the radiation pressure efficiencies of the particles, and comparisons with Mie scattering theory calculations provide the imaginary part of the refractive index of SiO2 and the corresponding extinction and scattering efficiencies.

  10. Neutron Measurements Using the Universal Radiation Spectrum Analyzer

    SciTech Connect

    Rick Cummings; Byron Christiansen; Laird Bean

    2005-02-01

    The Universal Radiation Spectrum Analyzer (URSA-II), developed by Radiation Safety Associates, and manufactured by SE International (Figure 1) is an interface between a radiation detector and a personal computer. Originally, the URSA-II was developed for use with detectors that measure the energy of gamma rays. At the Idaho National Laboratory, the URSA-II is an integral part of standard measurement techniques to measure characteristics of neutron radiation fields. Those techniques are discussed briefly and spectra using the URSA-II are presented.

  11. Measurement of radiation exposure of astronauts by radiochemical techniques

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.

    1973-01-01

    A cosmic radiation dose to the Apollo 17 crew of 1.3 R was calculated from the specific activities of Na-24 in their postflight urine specimens. The specific activities of K-42, Cr-51, Co60, and Sb-124, introduced by injection into the astronauts, are extremely high in these specimens. The Fe-59 and Cs-137 levels are also reported and appear to be normal. The concentrations of Na, K, Rb, Cs, Ca, Sr, Ba, Cr, Fe, Co, Ag, Au, Zn, Cd, Hg, Sn, As, Sb, Se, Br, Sc, La, Sm, Eu, Tb, Hf, Ta, and Th were measured in urine specimens from the Apollo 17 astronauts by neutron activation analysis. Strontium, barium, gold, cadmium, lanthanum, samarium, europium, terbium, thorium, and tin are reported for the first time. The concentrations or excretion rates of bromine and the alkali metals exhibit singificantly reduced postflight levels and are generally lower than values observed for previous missions. Chromium concentrations reflect radiochromium injections.

  12. Method for increased sensitivity of radiation detection and measurement

    DOEpatents

    Miller, Steven D.

    1994-01-01

    Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength. Reduced background is accomplished by more thorough annealing and enhanced radiation induced luminescence is obtained by treating the crystalline material to coalesce primary damage centers into secondary damage centers.

  13. Pyroelectric detector development for the Radiation Measurement system

    NASA Technical Reports Server (NTRS)

    Hubbard, G. S.; Mcmurray, Robert E., Jr.; Hanel, R. P.; Dominguez, D. E.; Valero, F. P. J.; Baumann, Hilary; Hansen, W. L.; Haller, E. E.

    1993-01-01

    A new class of high detectivity pyroelectric detectors developed for optimization of the radiation measurement system within the framework of the Atmospheric Radiation Measurement program is described. These devices are intended to provide detectivities of up to about 10 exp 11 cm Hz exp 0.5/W with cooling to about 100 K required for the detector focal plane.

  14. Measurements of the frequency spectrum of transition radiation

    NASA Technical Reports Server (NTRS)

    Cherry, M. L.; Mueller, D.

    1977-01-01

    We report a measurement of the frequency spectrum of X-ray transition radiation. X rays were generated by electrons of 5 and 9 GeV in radiators of multiple polypropylene foils, and detected in the range 4 to 30 keV with a calibrated single-crystal Bragg spectrometer. The experimental results closely reproduce the features of the theoretically predicted spectrum. In particular, the pronounced interference pattern of multifoil radiators and the expected hardening of the radiation with increasing foil thickness are clearly observed. The overall intensity of the radiation is somewhat lower than predicted by calculations.

  15. Status of LDEF ionizing radiation measurements and analysis

    NASA Technical Reports Server (NTRS)

    Parnell, Thomas A.

    1993-01-01

    At this symposium significant new data and analyses were reported in cosmic ray research, radiation dosimetry, induced radioactivity, and radiation environment modeling. Measurements of induced radioactivity and absorbed dose are nearly complete, but much analysis and modeling remains. Measurements and analyses of passive nuclear track detectors (PNTD), used to derive the cosmic ray composition and spectra, and linear energy transfer (LET) spectra, are only a few percent complete, but important results have already emerged. As one might expect at this stage of the research, some of the new information has produced questions rather than answers. Low-energy heavy nuclei detected by two experiments are not compatible with known solar or cosmic components. Various data sets on absorbed dose are not consistent, and a new trapped proton environment model does not match the absorbed dose data. A search for cosmogenic nuclei other than Be-7 on Long Duration Exposure Facility (LDEF) surfaces has produced an unexpected result, and some activation data relating to neutrons is not yet understood. Most of these issues will be resolved by the analysis of further experiment data, calibrations, or the application of the large LDEF data set that offers alternate data or analysis techniques bearing on the same problem. The scope of the papers at this symposium defy a compact technical summary. I have attempted to group the new information that I noted into the following groups: induced radioactivity; absorbed dose measurements; LET spectra and heavy ion dosimetry; environment modeling and three dimensional shielding effects; cosmogenic nuclei; and cosmic rays and other heavy ions. The papers generally are expository and have excellent illustrations, and I refer to their figures rather than reproduce them here. The general program and objectives of ionizing radiation measurements and analyses on LDEF has been described previously.

  16. Measurement of radiation property of long infrared emitter and examination of infrared radiation heating process

    NASA Astrophysics Data System (ADS)

    Nakano, Y.; Miyanaga, T.; Miyakawa, M.

    1989-05-01

    Long infrared radiation is becoming widely used for process heating, drying and space heating. In order to make more effective use of long infrared radiation, the investigations on measuring method of radiation property of long infrared emitter, the measuring results, and selection of suitable emitters for heating objects, were carried out. Using Fourier transform infrared radiation spectrophotometer, trial manufacture of an apparatus for measuring spectral emissivity of long infrared emitters was conducted and the measuring method was established. By this, the following knowledges on ceramic long infrared emitter were obtained: spectral emissivity almost never depends on temperature of the emitter, variation with time is hardly shown, and radiation efficiency is shown to be 50 to 60 percent. Infrared radiation heating processes on foods and synthetic resins were investigated, and an examination on the method for selecting emitters, which are suitable to materials to be heated, was conducted.

  17. Quantifying reflectance anisotropy of photosynthetically active radiation in grasslands

    NASA Technical Reports Server (NTRS)

    Middleton, Elizabeth M.

    1992-01-01

    Quantifying the vegetative surface's reflectance anisotropy was an important part of the First ISLSCP Field Experiment, as its major objectives focused on retrieval of surface parameters from satellite-derived reflectances. The explicit remote measurements for approximating the bidirectional reflectance distribution function (BRDF) of photosynthetically active radiation had not been previously undertaken. In this paper the proper expression of reflectance for BRDFs for retrieval of canopy parameters is assessed.

  18. Ground truth data for test sites (SL-4). [thermal radiation brightness temperature and solar radiation measurments

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Field measurements performed simultaneous with Skylab overpass in order to provide comparative calibration and performance evaluation measurements for the EREP sensors are presented. Wavelength region covered include: solar radiation (400 to 1300 nanometer), and thermal radiation (8 to 14 micrometer). Measurements consisted of general conditions and near surface meteorology, atmospheric temperature and humidity vs altitude, the thermal brightness temperature, total and diffuse solar radiation, direct solar radiation (subsequently analyzed for optical depth/transmittance), and target reflectivity/radiance. The particular instruments used are discussed along with analyses performed. Detailed instrument operation, calibrations, techniques, and errors are given.

  19. PRELIMINARY MEASURMENTS OF THE HIGH-GAIN FEL RADIATION PROPERTIES ALONG THE RADIATOR.

    SciTech Connect

    SHAFTAN,T.; LOOS,H.; SHEEHY,B.; YU,L.H.

    2004-08-29

    We present preliminary experimental results on evolution of properties of the DUV FEL [1,2] radiation along the radiator. Intercepting the electron beam at the different locations inside the undulator we recorded and analyzed transverse profiles, spectra and intensity of the FEL output. Shot-to-shot fluctuations of the FEL radiation may significantly affect the accuracy of measurement. In the paper we present and discuss a single-shot measurement technique, based on a special imaging system.

  20. Effective UV radiation from model calculations and measurements

    NASA Technical Reports Server (NTRS)

    Feister, Uwe; Grewe, Rolf

    1994-01-01

    Model calculations have been made to simulate the effect of atmospheric ozone and geographical as well as meteorological parameters on solar UV radiation reaching the ground. Total ozone values as measured by Dobson spectrophotometer and Brewer spectrometer as well as turbidity were used as input to the model calculation. The performance of the model was tested by spectroradiometric measurements of solar global UV radiation at Potsdam. There are small differences that can be explained by the uncertainty of the measurements, by the uncertainty of input data to the model and by the uncertainty of the radiative transfer algorithms of the model itself. Some effects of solar radiation to the biosphere and to air chemistry are discussed. Model calculations and spectroradiometric measurements can be used to study variations of the effective radiation in space in space time. The comparability of action spectra and their uncertainties are also addressed.

  1. Lessons learned from the Radiation measurements of the Mars Science Lab Radiation Assessment Detector (MSL-RAD)

    NASA Astrophysics Data System (ADS)

    Reitz, Guenther; Ottolenghi, Andrea

    2016-07-01

    The Radiation Assessment Detector (RAD) was designed to characterize the radiation environment on the Mars surface and to contribute to an improved assessment of radiation risk for a future human mission to Mars. The flight was chosen to cover a period of solar maximum activity to allow besides the measurement of the galactic cosmic rays an intense study of exposures by solar particle events. The Mars Science Laboratory spacecraft (MSL), containing the Curiosity rover, in which RAD was integrated, was launched to Mars on November 26, 2011. Although not part of the mission planning, RAD was operated already during the 253 day and 560 million km cruise to Mars and made the first time detailed measurements of a radiation environment comparable to that inside a future spacecraft carrying humans to Mars and in other deep space missions. Exactly 100 years after the discovery of cosmic rays on August 7, 1912 RAD makes the first observation of the radiation environment on the surface of another planet and is still gathering data until today. Meanwhile the maximum activity of the current solar cycle has been passed and the solar activity is decreasing. Unfortunately the present solar cycle was an unexpected weak cycle. As a matter of fact only very small solar particle events could be observed during the still ongoing RAD measurements. The paper highlights the achievements of RAD by presenting selected data measured during the cruise and on the Mars surface and describes its impact on predictive models for health risks of astronauts during space missions.

  2. ACTIVITIES: Centimeter and Millimeter Measurements

    ERIC Educational Resources Information Center

    Bolster, L. Carey

    1974-01-01

    An activity is suggested which will give junior high school students practice in estimating and measuring in centimeters and millimeters. Three worksheets are given, one of which is a model for making a metric caliper. (LS)

  3. The measured radiation environment within Spacelabs 1 and 2 and comparison with predictions

    NASA Technical Reports Server (NTRS)

    Parnell, T. A.; Watts, J. W., Jr.; Fishman, G. J.; Benton, E. V.; Frank, A. L.

    1986-01-01

    A set of passive and active radiation detectors was flown as part of the verification flight instrumentation (VFI) in an attempt to measure the radiation environment in the Spacelab (SL) module and on the pallet. SL 1 carried 4 passive and 2 active detector packages which were used to evaluate the radiation environment within the spacecraft and SL 2 carried 2 passive VFI units on the pallet. Dose equivalents of 330 + or - 70 mrem and 537 + or - 37 mrem were measured in the SL 1 module and SL 2 pallet, respectively.

  4. Measuring radiation dose to patients undergoing fluoroscopically-guided interventions

    NASA Astrophysics Data System (ADS)

    Lubis, L. E.; Badawy, M. K.

    2016-03-01

    The increasing prevalence and complexity of fluoroscopically guided interventions (FGI) raises concern regarding radiation dose to patients subjected to the procedure. Despite current evidence showing the risk to patients from the deterministic effects of radiation (e.g. skin burns), radiation induced injuries remain commonplace. This review aims to increase the awareness surrounding radiation dose measurement for patients undergoing FGI. A review of the literature was conducted alongside previous researches from the authors’ department. Studies pertaining to patient dose measurement, its formalism along with current advances and present challenges were reviewed. Current patient monitoring techniques (using available radiation dosimeters), as well as the inadequacy of accepting displayed dose as patient radiation dose is discussed. Furthermore, advances in real-time patient radiation dose estimation during FGI are considered. Patient dosimetry in FGI, particularly in real time, remains an ongoing challenge. The increasing occurrence and sophistication of these procedures calls for further advances in the field of patient radiation dose monitoring. Improved measuring techniques will aid clinicians in better predicting and managing radiation induced injury following FGI, thus improving patient care.

  5. BOREAS HYD-3 Subcanopy Incoming Solar Radiation Measurements

    NASA Technical Reports Server (NTRS)

    Hardy, Janet P.; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Davis, Robert E.; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-3 team collected several data sets related to the hydrology of forested areas. This data set contains solar radiation measurements from several pyranometers (solar radiometers) placed on the snow surface in jack pine (1994) and black spruce and aspen forests (1996) in the BOREAS southern study area (SSA). An array of radiometers was used to collect data for three to four consecutive days in each forest type to study the hypothesis that energy transfer and snow water equivalent would vary spatially as a function of canopy closure. The quality of the data is good, because the days were generally clear and the radiometers were checked daily to remove anything that landed on the radiometers. The data are available in tabular ASCII files. The subcanopy incoming solar radiation measurement data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  6. 47 CFR 2.1511 - Measurements of radiated emissions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Measurements of radiated emissions. The Commission's Rules require that the peak efficetive radiated power... quarter-wave monopole antenna located on a one wavelength minimum diameter metal ground plane. The Rules... (1) Place a 121.5 MHz quarter-wave vertical antenna element at the center of the ground plane...

  7. Traceability of radiation measurements: musings of a user

    SciTech Connect

    Kathren, R.L.

    1980-04-01

    Although users of radiation desire measurement traceability for a number of reasons, including legal, regulatory, contractual, and quality assurance requirements, there exists no real definition of the term in the technical literature. Definitions are proposed for both traceability and traceability to the National Bureau of Standards. The hierarchy of radiation standards is discussed and allowable uncertainties are given for each level. Areas of need with respect to radiation standards are identified, and a system of secondary radiation calibration laboratories is proposed as a means of providing quality calibrations and traceability on a routine basis.

  8. An active control strategy for achieving weak radiator structures

    SciTech Connect

    Naghshineh, K. . Acoustics and Radar Technology Lab.); Koopmann, G.H. . Center for Acoustics and Vibration)

    1994-01-01

    A general control strategy is presented for active suppression of total radiated sound power from harmonically excited structures based on the measurement of their response. Using the measured response of the structure together with knowledge of its structural mobility, and equivalent primary excitation force is found at discrete points along the structure. Using this equivalent primary force and performing a quadratic optimization of the power radiated form the structure, a set of control forces is found at selected points on the structure that results in minimum radiated sound power. A numerical example of this strategy is presented for a simply supported beam in a rigid baffle excited by a harmonic plane wave incident at an oblique angle. A comparison of the response of the beam with and without control forces shows a large reduction in the controlled response displacement magnitude. In addition, as the result of the action of the control forces, the magnitude of the wave number spectrum of the beam's response in the supersonic region is decreased substantially. The effect of the number and location of the actuators on reductions in sound power level is also studied. The actuators located at the anti-nodes of structural modes within the supersonic region together with those located near boundaries are found to be the most effective in controlling the radiation of sound from a structure.

  9. Measuring plasma turbulence using low coherence microwave radiation

    SciTech Connect

    Smith, D. R.

    2012-02-20

    Low coherence backscattering (LCBS) is a proposed diagnostic technique for measuring plasma turbulence and fluctuations. LCBS is an adaptation of optical coherence tomography, a biomedical imaging technique. Calculations and simulations show LCBS measurements can achieve centimeter-scale spatial resolution using low coherence microwave radiation. LCBS measurements exhibit several advantages over standard plasma turbulence measurement techniques including immunity to spurious reflections and measurement access in hollow density profiles. Also, LCBS is scalable for 1-D profile measurements and 2-D turbulence imaging.

  10. Measurements and evaluation of the risks due to external radiation exposures and to intake of activated elements for operational staff engaged in the maintenance of medical cyclotrons.

    PubMed

    Calandrino, R; del Vecchio, A; Parisi, R; Todde, S; De Felice, P; Savi, A; Pepe, A; Mrskova, A

    2010-06-01

    The aim of this paper is to assess the activation phenomena and to evaluate the risk of external exposure and intake doses for the maintenance staff of two medical cyclotrons. Two self-shielded cyclotrons are currently operating in the facility for the routine production of (11)C and (18)F. Four radiochemistry laboratories are linked to the cyclotrons by means of shielded radioisotope delivery lines. Radiopharmaceuticals are prepared both for the PET Diagnostic Department, where four CT-PET scanners are operating with a mean patient workload of 40 d(-1) and for [(18)F]FDG external distribution, to provide radiopharmaceuticals for other institutions. In spite of the fact that air contamination inside the radiochemistry laboratories during the synthesis represents the largest 'slice of the pie' in the evaluation of annual intake dose, potential contamination due to the activated particulate, generated during cyclotron irradiation by micro-corrosion of targets and other components potentially struck by the proton beam and generated neutrons, should be considered. In this regard, the most plausible long-lived (T(1/2) > 30 d) radioisotopes formed are: (97)Tc, (56)Co, (57)Co, (58)Co, (60)Co, (49)V, (55)Fe, (109)Cd, (65)Zn and (22)Na. The results for the operating personnel survey has revealed only low-level contamination for (65)Zn in one test, together with minor (18)F intake, probably due to the environmental dispersion of the radioisotope during the [(18)F]FDG synthesis.

  11. Nuclear radiation-warning detector that measures impedance

    SciTech Connect

    Savignac, Noel Felix; Gomez, Leo S; Yelton, William Graham; Robinson, Alex; Limmer, Steven

    2013-06-04

    This invention is a nuclear radiation-warning detector that measures impedance of silver-silver halide on an interdigitated electrode to detect light or radiation comprised of alpha particles, beta particles, gamma rays, X rays, and/or neutrons. The detector is comprised of an interdigitated electrode covered by a layer of silver halide. After exposure to alpha particles, beta particles, X rays, gamma rays, neutron radiation, or light, the silver halide is reduced to silver in the presence of a reducing solution. The change from the high electrical resistance (impedance) of silver halide to the low resistance of silver provides the radiation warning that detected radiation levels exceed a predetermined radiation dose threshold.

  12. Measurements of the cosmic background radiation

    NASA Technical Reports Server (NTRS)

    Lubin, P.; Villela, T.

    1987-01-01

    Maps of the large scale structure (theta is greater than 6 deg) of the cosmic background radiation covering 90 percent of the sky are now available. The data show a very strong 50-100 sigma (statistical error) dipole component, interpreted as being due to our motion, with a direction of alpha = 11.5 + or - 0.15 hours, sigma = -5.6 + or - 2.0 deg. The inferred direction of the velocity of our galaxy relative to the cosmic background radiation is alpha = 10.6 + or - 0.3 hours, sigma = -2.3 + or - 5 deg. This is 44 deg from the center of the Virgo cluster. After removing the dipole component, the data show a galactic signature but no apparent residual structure. An autocorrelation of the residual data, after substraction of the galactic component from a combined Berkeley (3 mm) and Princeton (12 mm) data sets, show no apparent structure from 10 to 180 deg with a rms of 0.01 mK(sup 2). At 90 percent confidence level limit of .00007 is placed on a quadrupole component.

  13. Measuring Substantial Reductions in Activity

    PubMed Central

    Schafer, Charles; Evans, Meredyth; Jason, Leonard A.; So, Suzanna; Brown, Abigail

    2015-01-01

    The case definitions for Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), Myalgic Encephalomyelitis (ME), and chronic fatigue syndrome (CFS) each include a disability criterion requiring substantial reductions in activity in order to meet diagnostic criteria. Difficulties have been encountered in defining and operationalizing the substantial reduction disability criterion within these various illness definitions. The present study sought to relate measures of past and current activities in several domains including the SF-36, an objective measure of activity (e.g. actigraphy), a self-reported quality of life scale, and measures of symptom severity. Results of the study revealed that current work activities had the highest number of significant associations with domains such as the SF-36 subscales, actigraphy, and symptom scores. As an example, higher self-reported levels of current work activity were associated with better health. This suggests that current work related activities may provide a useful domain for helping operationalize the construct of substantial reductions in activity. PMID:25584524

  14. Measurement of divergence of co/sub 2/-laser radiation

    SciTech Connect

    Shepelenko, A.A.; Shulyat'ev, V.B.

    1986-04-01

    This paper presents a modification of the Foucault method for measuring the radiation divergence of high-power CW lasers in which the limiting diaphram is produced by an aperture burned through by the laser radiation itself. The method is suitable for beams with any cross-sectional intensitiy distribution. Results of divergence measurements of a CO/sub 2/ production laser with power to 2 kW are presented.

  15. Partial pressure measurements with an active spectrometer

    SciTech Connect

    Brooks, N.H.; Jensen, T.H.; Colchin, R.J.; Maingi, R.; Wade, M.R.; Finkenthal, D.F.; Naumenko, N.; Tugarinov, S.

    1998-07-01

    Partial pressure neutral ga measurements have been made using a commercial Penning gauge in conjunction with an active spectrometer. In prior work utilizing bandpass filters and conventional spectrometers, trace concentrations of the hydrogen isotopes H, D, T and of the noble gases He, Ne and Ar were determined from characteristic spectral lines in the light emitted by the neutral species of these elements. For all the elements mentioned, the sensitivity was limited by spectral contamination from a pervasive background of molecular hydrogen radiation. The active spectrometer overcomes this limitations by means of a digital lock-in method and correlation with reference spectra. Preliminary measurements of an admixture containing a trace amount of neon in deuterium show better than a factor of 20 improvement in sensitivity over conventional techniques. This can be further improved by correlating the relative intensities of multiple lines to sets of reference spectra.

  16. Evaluation of the shortwave radiative balance via measurements and calculations

    NASA Astrophysics Data System (ADS)

    Amann, V.; Koepke, P.; Quenzel, H.; Kriebel, K. T.

    A new method of calculating the shortwave radiative balance is presented. Radiative densities are measured while the atmospheric state values necessary for the calculation are assumed and varied. Two situations are used, a cloud-free atmosphere over ocean and a cloud-free atmosphere over a homogeneous land area southeast of Madrid. Aircraft measurements of spectral and integrated radiative densities obtained at various heights and angles are compared with the calculated values. The agreement is good, and the boundaries of the model at low height stand out.

  17. Balloon measurements of the far-infrared background radiation.

    NASA Technical Reports Server (NTRS)

    Muehlner, D.; Weiss, R.

    1973-01-01

    Description of a balloon-borne radiometer designed to make direct measurements of the background radiation in the spectral range from 1 to 20 cm, and evaluation of the results of two balloon flights performed with the aid of this radiometer. Measurements in five different passbands in the spectral region below 20 per cm were made with a liquid-helium-cooled radiometer in two flights at approximately 40-km altitude. The results obtained are found to be consistent with a 2.7 K thermal radiation background. In addition, an atmospheric radiation of certain magnitude is found to dominate the region above 11 per cm.

  18. Radiation measurements over a snowfield at an elevated site

    NASA Technical Reports Server (NTRS)

    Korff, H. C.; Gailiun, J. J.; Vonderhaar, T. H.

    1974-01-01

    The components of short wave radiation were measured over a snowfield in a valley of the Rocky Mountains at a height of 2700 m above sea level. Global and reflected radiation were obtained by a set of Eppley pyranometers. In addition, the direct solar radiation and the turbidity of the atmosphere were derived from pyrheliometric data on cloud-free days. Emphasis was given to the reflectance of the snowfield in relation to the position of the sun, especially at low elevation angles. These reflectance values were measured for cloudless as well as for cloudy days and compared with already published values for arctic and antarctic conditions.

  19. Measuring scatter radiation in diagnostic X rays for radiation protection purposes.

    PubMed

    Vlachos, Ioannis; Tsantilas, Xenophon; Kalyvas, Nektarios; Delis, Harry; Kandarakis, Ioannis; Panayiotakis, George

    2015-07-01

    During the last decades, radiation protection and dosimetry in medical X-ray imaging practice has been extensively studied. The purpose of this study was to measure secondary radiation in a conventional radiographic room, in terms of ambient dose rate equivalent H*(10) and its dependence on the radiographic exposure parameters such as X-ray tube voltage, tube current and distance. With some exceptions, the results indicated that the scattered radiation was uniform in the space around the water cylindrical phantom. The results also showed that the tube voltage and filtration affect the dose rate due to the scatter radiation. Finally, the scattered X-ray energy distribution was experimentally calculated.

  20. Estimation of Effective Doses for Radiation Cancer Risks on ISS, Lunar, and Mars Missions with Space Radiation Measurement

    NASA Technical Reports Server (NTRS)

    Kim, M.Y.; Cucinotta, F.A.

    2005-01-01

    Radiation protection practices define the effective dose as a weighted sum of equivalent dose over major sites for radiation cancer risks. Since a crew personnel dosimeter does not make direct measurement of effective dose, it has been estimated with skin-dose measurements and radiation transport codes for ISS and STS missions. The Phantom Torso Experiment (PTE) of NASA s Operational Radiation Protection Program has provided the actual flight measurements of active and passive dosimeters which were placed throughout the phantom on STS-91 mission for 10 days and on ISS Increment 2 mission. For the PTE, the variation in organ doses, which is resulted by the absorption and the changes in radiation quality with tissue shielding, was considered by measuring doses at many tissue sites and at several critical body organs including brain, colon, heart, stomach, thyroid, and skins. These measurements have been compared with the organ dose calculations obtained from the transport models. Active TEPC measurements of lineal energy spectra at the surface of the PTE also provided the direct comparison of galactic cosmic ray (GCR) or trapped proton dose and dose equivalent. It is shown that orienting the phantom body as actual in ISS is needed for the direct comparison of the transport models to the ISS data. One of the most important observations for organ dose equivalent of effective dose estimates on ISS is the fractional contribution from trapped protons and GCR. We show that for most organs over 80% is from GCR. The improved estimation of effective doses for radiation cancer risks will be made with the resultant tissue weighting factors and the modified codes.

  1. Measurement of natural background radiation intensity on a train.

    PubMed

    Chen, Yen-Fu; Lin, Jeng-Wei; Sheu, Rong-Jiun; Lin, Uei-Tyng; Jiang, Shiang-Huei

    2011-03-01

    This work aims to measure different components of natural background radiation on a train. A radiation measurement system consisting of four types of radiation detectors, namely, a Berkeley Lab cosmic-ray detector, moderated (3)He detector, high-pressure ionisation chamber and NaI(Tl) spectrometer, associated with a global positioning system unit was established for this purpose. For the commissioning of the system, a test measurement on a train along the railway around the northern Taiwan coast from Hsinchu to Hualien with a distance of ∼ 275 km was carried out. No significant variation of the intensities of the different components of natural background radiation was observed, except when the train went underground or in the tunnels. The average external dose rate received by the crew of the train was estimated to be 62 nSv h(-1).

  2. Radiation budget measurements for the eighties and nineties

    SciTech Connect

    Smith, G.L.; Barkstrom, B.R.; Harrison, E.F.; Lee, R.B. III; Wielicki, B.A. )

    1994-01-01

    The Earth Radiation Budget Experiment (ERBE) consisted of a scanning radiometer and non-scanning radiometers on each of three spacecraft. These instruments began flying in October 1984. The nonscanning radiometers continue to operate, providing broadband radiation measurements of the Earth's outgoing longwave radiation and reflected solar radiation, in addition to measurements of the solar output. The Clouds and Earth Radiant Energy System (CERES) features a scanning radiometer, which is an improved version of the ERBE scanning radiometer, and will fly on the Tropical Rainfall Measurement Mission and Earth Observation System platforms in the late nineties. The CERES project will provide not only radiant fluxes at the top of the atmosphere' (TOA), but also at the surface and will compute radiant flux divergence through the atmosphere.

  3. Radiation measurements from polar and geosynchronous satellites

    NASA Technical Reports Server (NTRS)

    Vonderhaar, T. H.; Kidder, S. Q.; Hillger, D. W.; Ellis, J. S.

    1978-01-01

    The following topics are discussed: (1) cloud effects in climate determination; (2) annual variation in the global heat balance of the earth; (3) the accuracy of precipitation estimates made from passive microwave measurements from satellites; (4) seasonal oceanic precipitation frequencies; (5) determination of mesoscale temperature and moisture fields over land from satellite radiance measurements; and (6) Nimbus 6 scanning microwave spectrometer data evaluation for surface wind and pressure components in tropical storms.

  4. An evaluation of RAMS radiation schemes by field measurements

    SciTech Connect

    Zhong, S; Doran, J C

    1994-02-01

    At present, two radiation schemes are used in RAMS: the Mahrer and Pielke (M-P) scheme and the Chen and Cotton (C-C) scheme. The M-P scheme requires little computational expense, but does not include the radiative effects of liquid water or ice; the C-C scheme accounts for the radiative effects of liquid water and ice but is fairly expensive computationally. For simulations with clouds, the C-C scheme is obviously a better choice, but for clear sky conditions, RAMS users face a decision regarding which radiation scheme to use. It has been noted that the choice of radiation scheme may result in significantly different results for the same case. To examine the differences in the radiative fluxes and the boundary-layer structure corresponding to the two radiation schemes in RAMS we have carried out a study where Rams was used to simulate the same case with two different radiation schemes. The modeled radiative fluxes by the two schemes were then compared with the field measurements. A description of the observations and the case study, a comparison and discussion of the results, and a summary and conclusions follow.

  5. ISS and Space Shuttle Radiation Measurements at Solar Minimum

    NASA Technical Reports Server (NTRS)

    Gaza, Ramona; Welton, Andrew; Dunegan, Audrey; Lee, Kerry

    2011-01-01

    A summary of 2008-2011 ISS and Space Shuttle radiation dosimetry results for inside vehicle radiation monitoring in low-Earth orbit will be presented. Results include new data from ISS Expedition 22-25/20A radiation area monitors (RAM) and Shuttle Missions STS127-STS133 passive radiation dosimeters (PRD). ISS 20A radiation measurement locations included three Node 2 crew quarters locations at NOD2S5_CQ, NOD2P5_CQ and CQ-3 (Deck), as well as ESA Columbus, and JAXA Kibo locations. ISS 20A and STS127-STS133 missions were flown at 51.6 inclination with an altitude range of 330-350 km. The passive radiation results will be presented in terms of measured daily dose obtained using luminescence detectors (i.e., Al2O3:C, LiF:Mg,Ti and CaF2:Tm). In addition, preliminary results from the DOSIS 2 Project, in collaboration with the German Space Agency (DLR) will be presented. SRAG s participation to the DOSIS 2 exposure on ISS (11/16/2009-05/26/2010) involved passive radiation measurements at 10 different shielding locations inside the ESA Columbus Module.

  6. Measurement of background gamma radiation in the northern Marshall Islands

    PubMed Central

    Bordner, Autumn S.; Crosswell, Danielle A.; Katz, Ainsley O.; Shah, Jill T.; Zhang, Catherine R.; Nikolic-Hughes, Ivana; Hughes, Emlyn W.; Ruderman, Malvin A.

    2016-01-01

    We report measurements of background gamma radiation levels on six islands in the northern Marshall Islands (Enewetak, Medren, and Runit onEnewetak Atoll; Bikini and Nam on Bikini Atoll; and Rongelap on Rongelap Atoll). Measurable excess radiation could be expected from the decay of 137Cs produced by the US nuclear testing program there from 1946 to 1958. These recordings are of relevance to safety of human habitation and resettlement. We find low levels of gamma radiation for the settled island of Enewetak [mean = 7.6 millirem/year (mrem/y) = 0.076 millisievert/year (mSv/y)], larger levels of gamma radiation for the island of Rongelap (mean = 19.8 mrem/y = 0.198 mSv/y), and relatively high gamma radiation on the island of Bikini (mean = 184 mrem/y = 1.84 mSv/y). Distributions of gamma radiation levels are provided, and hot spots are discussed. We provide interpolated maps for four islands (Enewetak, Medren, Bikini, and Rongelap), and make comparisons to control measurements performed on the island of Majuro in the southern Marshall Islands, measurements made in Central Park in New York City, and the standard agreed upon by the United States and the Republic of the Marshall Islands (RMI) governments (100 mrem/y = 1 mSv/y). External gamma radiation levels on Bikini Island significantly exceed this standard (P = <<0.01), and external gamma radiation levels on the other islands are below the standard. To determine conclusively whether these islands are safe for habitation, radiation exposure through additional pathways such as food ingestion must be considered. PMID:27274073

  7. Measurement of background gamma radiation in the northern Marshall Islands.

    PubMed

    Bordner, Autumn S; Crosswell, Danielle A; Katz, Ainsley O; Shah, Jill T; Zhang, Catherine R; Nikolic-Hughes, Ivana; Hughes, Emlyn W; Ruderman, Malvin A

    2016-06-21

    We report measurements of background gamma radiation levels on six islands in the northern Marshall Islands (Enewetak, Medren, and Runit onEnewetak Atoll; Bikini and Nam on Bikini Atoll; and Rongelap on Rongelap Atoll). Measurable excess radiation could be expected from the decay of (137)Cs produced by the US nuclear testing program there from 1946 to 1958. These recordings are of relevance to safety of human habitation and resettlement. We find low levels of gamma radiation for the settled island of Enewetak [mean = 7.6 millirem/year (mrem/y) = 0.076 millisievert/year (mSv/y)], larger levels of gamma radiation for the island of Rongelap (mean = 19.8 mrem/y = 0.198 mSv/y), and relatively high gamma radiation on the island of Bikini (mean = 184 mrem/y = 1.84 mSv/y). Distributions of gamma radiation levels are provided, and hot spots are discussed. We provide interpolated maps for four islands (Enewetak, Medren, Bikini, and Rongelap), and make comparisons to control measurements performed on the island of Majuro in the southern Marshall Islands, measurements made in Central Park in New York City, and the standard agreed upon by the United States and the Republic of the Marshall Islands (RMI) governments (100 mrem/y = 1 mSv/y). External gamma radiation levels on Bikini Island significantly exceed this standard (P = <0.01), and external gamma radiation levels on the other islands are below the standard. To determine conclusively whether these islands are safe for habitation, radiation exposure through additional pathways such as food ingestion must be considered.

  8. Measurement of background gamma radiation in the northern Marshall Islands.

    PubMed

    Bordner, Autumn S; Crosswell, Danielle A; Katz, Ainsley O; Shah, Jill T; Zhang, Catherine R; Nikolic-Hughes, Ivana; Hughes, Emlyn W; Ruderman, Malvin A

    2016-06-21

    We report measurements of background gamma radiation levels on six islands in the northern Marshall Islands (Enewetak, Medren, and Runit onEnewetak Atoll; Bikini and Nam on Bikini Atoll; and Rongelap on Rongelap Atoll). Measurable excess radiation could be expected from the decay of (137)Cs produced by the US nuclear testing program there from 1946 to 1958. These recordings are of relevance to safety of human habitation and resettlement. We find low levels of gamma radiation for the settled island of Enewetak [mean = 7.6 millirem/year (mrem/y) = 0.076 millisievert/year (mSv/y)], larger levels of gamma radiation for the island of Rongelap (mean = 19.8 mrem/y = 0.198 mSv/y), and relatively high gamma radiation on the island of Bikini (mean = 184 mrem/y = 1.84 mSv/y). Distributions of gamma radiation levels are provided, and hot spots are discussed. We provide interpolated maps for four islands (Enewetak, Medren, Bikini, and Rongelap), and make comparisons to control measurements performed on the island of Majuro in the southern Marshall Islands, measurements made in Central Park in New York City, and the standard agreed upon by the United States and the Republic of the Marshall Islands (RMI) governments (100 mrem/y = 1 mSv/y). External gamma radiation levels on Bikini Island significantly exceed this standard (P = <0.01), and external gamma radiation levels on the other islands are below the standard. To determine conclusively whether these islands are safe for habitation, radiation exposure through additional pathways such as food ingestion must be considered. PMID:27274073

  9. The radiation balance of the earth-atmosphere system from Nimbus 3 radiation measurements

    NASA Technical Reports Server (NTRS)

    Raschke, E.; Vonderhaar, T. H.; Pasternak, M.; Bandeen, W. R.

    1973-01-01

    The radiation balance of the earth-atmosphere system and its components was computed from global measurements of radiation reflected and emitted from the earth to space. These measurements were made from the meteorological satellite Nimbus 3 during the periods from April 16 to August 15, 1969; October 3 to 17, 1969; and January 21 to February 3, 1970. Primarily the method of evaluation, its inherent assumptions, and possible error sources were discussed. Results are presented by various methods: (1) global, hemispherical, and zonal averages obtained from measurements in all semimonthly periods and (2) global maps of the absorbed solar radiation, the albedo, the outgoing longwave radiation, and the radiation balance obtained from measurements during semimonthly periods in each season (May 1 to 15, July 16 to 31, and October 3 to 17, 1969, and January 21 to February 3, 1970). Annual global averages of the albedo and of the outgoing longwave radiation were determined. These values balance to within 1 percent the annual global energy input by solar radiation that was computed for a solar constant.

  10. Advances in Atmospheric Radiation Measurements and Modeling Needed to Improve Air Safety

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent; Atwell, William; Beck, Peter; Benton, Eric; Copeland, Kyle; Dyer, Clive; Gersey, Brad; Getley, Ian; Hands, Alex; Holland, Michael; Hong, Sunhak; Hwang, Junga; Jones, Bryn; Malone, Kathleen; Meier, Matthias M.; Mertens, Chris; Phillips, Tony; Ryden, Keith; Schwadron, Nathan; Wender, Stephen A.; Wilkins, Richard; Xapsos, Michael A.

    2015-04-01

    Air safety is tied to the phenomenon of ionizing radiation from space weather, primarily from galactic cosmic rays but also from solar energetic particles. A global framework for addressing radiation issues in this environment has been constructed, but more must be done at international and national levels. Health consequences from atmospheric radiation exposure are likely to exist. In addition, severe solar radiation events may cause economic consequences in the international aviation community due to exposure limits being reached by some crew members. Impacts from a radiation environment upon avionics from high-energy particles and low-energy, thermalized neutrons are now recognized as an area of active interest. A broad community recognizes that there are a number of mitigation paths that can be taken relative to the human tissue and avionics exposure risks. These include developing active monitoring and measurement programs as well as improving scientific modeling capabilities that can eventually be turned into operations. A number of roadblocks to risk mitigation still exist, such as effective pilot training programs as well as monitoring, measuring, and regulatory measures. An active international effort toward observing the weather of atmospheric radiation must occur to make progress in mitigating radiation exposure risks. Stakeholders in this process include standard-making bodies, scientific organizations, regulatory organizations, air traffic management systems, aircraft owners and operators, pilots and crew, and even the public.

  11. Biological trace element measurements using synchrotron radiation

    SciTech Connect

    Giauque, R.D.; Jaklevic, J.M.; Thompson, A.C.

    1985-07-01

    The feasibility of performing x-ray fluorescence trace element determinations at concentrations substantially below the ppM level for biological materials is demonstrated. Conditions for achieving optimum sensitivity were ascertained. Results achieved for five standard reference materials were, in most cases, in excellent agreement with listed values. Minimum detectable limits of 20 ppM were measured for most elements.

  12. Aerosol direct radiative effect over China estimated with visibility measurements

    NASA Astrophysics Data System (ADS)

    Ye, K.; Lin, J.

    2012-12-01

    As a short-lived climate forcer, aerosols exhibit strong radiative effects that vary significantly across the space and time. Current understanding of the long-term variability of aerosol climate forcings is however very poor due to lack of relevant atmospheric measurements. Historic records for visibility measurements from thousands of ground meteorological stations offer a plausible tool to study the decadal and multi-decadal variability of aerosol radiative effects. As a first step, this study presents a method to estimate aerosol direct radiative effect over China based on visibility data for 2006. Visibility data from about 400 ground stations are converted to near-surface aerosol extinction coefficients, which are converted then to aerosol optical depth (AOD) based on spatially and temporally varying vertical distributions of aerosol optical properties simulated by the widely used chemical transport model GEOS-Chem. The resulting AOD data are consistent with direct measurements from the China Aerosol Remote Sensing Network (CARSNET) and the Aerosol Robotic Network (AERONET) in regions where visibility and AOD measurement sites are close in distance. Next, the visibility-derived AOD data are combined with other aerosol optical properties adopted from GEOS-Chem, cloud data from ground stations and surface albedo data from moderate-resolution imaging spectroradiometer (MODIS) to derive the direct radiative effect, by employing the Santa Barbara DISORT Atmospheric Radiative Transfer model (SBDART). Spatial and monthly variations of aerosol radiative effects are examined.

  13. Radiation Pressure Measurements on Micron Size Individual Dust Grains

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Craven, P.D.; Spann, J. F.; Tankosic, D.; Witherow, W. K.; LeClair, A.; West, E.; Sheldon, R.; Gallagher, D. L.; Adrian, M. L.

    2003-01-01

    Measurements of electromagnetic radiation pressure have been made on individual silica (SiO2) particles levitated in an electrodynamic balance. These measurements were made by inserting single charged particles of known diameter in the 0.2 micron to 6.82 micron range and irradiating them from above with laser radiation focused to beam-widths of approx. 175-400 micron, at ambient pressures approx. 10(exp -3) to 10(exp -4) torr. The downward displacement of the particle due to the radiation force is balanced by the electrostatic force indicated by the compensating dc potential applied to the balance electrodes, providing a direct measure of the radiation force on the levitated particle. Theoretical calculations of the radiation pressure with a least-squares fit to the measured data yield the radiation pressure efficiencies of the particles, and comparisons with Mie scattering theory calculations provide the imaginary part of the refractive index of silica and the corresponding extinction and scattering efficiencies.

  14. Method and apparatus for measuring spatial uniformity of radiation

    DOEpatents

    Field, Halden

    2002-01-01

    A method and apparatus for measuring the spatial uniformity of the intensity of a radiation beam from a radiation source based on a single sampling time and/or a single pulse of radiation. The measuring apparatus includes a plurality of radiation detectors positioned on planar mounting plate to form a radiation receiving area that has a shape and size approximating the size and shape of the cross section of the radiation beam. The detectors concurrently receive portions of the radiation beam and transmit electrical signals representative of the intensity of impinging radiation to a signal processor circuit connected to each of the detectors and adapted to concurrently receive the electrical signals from the detectors and process with a central processing unit (CPU) the signals to determine intensities of the radiation impinging at each detector location. The CPU displays the determined intensities and relative intensity values corresponding to each detector location to an operator of the measuring apparatus on an included data display device. Concurrent sampling of each detector is achieved by connecting to each detector a sample and hold circuit that is configured to track the signal and store it upon receipt of a "capture" signal. A switching device then selectively retrieves the signals and transmits the signals to the CPU through a single analog to digital (A/D) converter. The "capture" signal. is then removed from the sample-and-hold circuits. Alternatively, concurrent sampling is achieved by providing an A/D converter for each detector, each of which transmits a corresponding digital signal to the CPU. The sampling or reading of the detector signals can be controlled by the CPU or level-detection and timing circuit.

  15. Techniques for measuring radiation induced effects of acousto optic devices

    SciTech Connect

    Taylor, E.W.

    1995-08-01

    Innovative measurement techniques for determining radiation induced changes in acousto optic devices are briefly discussed. Measurements of acousto optic operational parameters such as signal transmission efficiency, diffraction efficiency, spatial intensity and bandwidth responses during electron irradiations are described. During exposure to pulsed electrons, only transient perturbations to the acousto optic operational parameters were experienced. Examples of new measurement procedures and typical data resulting from the measurements are presented.

  16. Measurement of radiation exposure of astronauts by radiochemical techniques

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.

    1973-01-01

    A cosmic radiation dose to the Apollo 16 crew of 180 + or - 100 mR was calculated from the specific activities of Na-22 and Na-24 in pre and postflight urine specimens. The specific activities of Cr-51 and Co-60 are higher in postflight specimens than in preflight specimens, presumably due to a postflight injection of radiochromium. The Fe-59 and Cs-137 specific activities are also reported and appear to be normal. The radiation doses received by a pilot and a navigator flying a high altitude mission during the solar flare of August 4 to 9, 1972 were calculated from the specific activity of Na-24 in their urine. These values are compared with the expected radiation dose calculated form the known shape and intensity of the proton spectrum. They demonstrate the magnitude of atmospheric shielding.

  17. Atmospheric radiation measurement program facilities newsletter, April 2001.

    SciTech Connect

    Holdridge, D. J.

    2001-05-03

    Intensive Observation Period Projects Scheduled--Several IOP projects have been scheduled for the SGP CART site this spring. These projects either have already begun or will begin shortly. Radiosondes--The RS-90 Transition IOP is currently under way. The RS-90 model radiosonde is gradually replacing the older RS-80 model. Radiosondes are instrument packages attached to and launched by weather balloons. The instruments measure atmospheric pressure, temperature, and relative humidity as the balloon rises through the air. The new RS-90 model is a high-performance radiosonde with fast-response sensors capable of providing data for each variable every second. The relatively environmentally friendly package is constructed of cardboard and steel rather than Styrofoam, and it has a water-activated battery that contains no toxic substances. The RS-90 Transition IOP is taking place during April. Operators will launch both the old RS-80 and the new RS-90 radiosondes simultaneously once each day to obtain duplicate vertical profiles of the atmosphere for comparison. This procedure will also allow data users to test the output from the old and new radiosondes in models. Narrow Field of View (NFOV) Solar Spectrometer Cloud Optical Depth Retrieval Campaign--The NFOV IOP is scheduled to take place on May 7-August 31, 2001. A researcher from Pennsylvania State University will be deploying a dual-spectrometer instrument that measures the hemispheric flux and zenith NFOV radiance over a wavelength range of 300- 1000 nanometers. (One nanometer equals 1 billionth of a meter or 0.000000039 inches.) This wavelength range includes the ultraviolet, visible, and near-infrared spectra. These measurements are used to estimate cloud optical depth--a quantity related to the amount of solar radiation intercepted by a cloud--for broken cloud fields over vegetated surfaces. The IOP measurements will be compared with optical depth measurements made by SGP instruments. Precision Gas Sampling (PGS

  18. Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2008

    SciTech Connect

    LR Roeder

    2008-12-01

    The Importance of Clouds and Radiation for Climate Change: The Earth’s surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols, can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earth’s energy balance. In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To reduce these scientific uncertainties, the ARM Program uses a unique twopronged approach: • The ARM Climate Research Facility, a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes; and • The ARM Science Program, focused on the analysis of ACRF and other data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report provides an overview of each of these components and a sample of achievements for each in fiscal year (FY) 2008.

  19. Absolute Radiation Measurements in Earth and Mars Entry Conditions

    NASA Technical Reports Server (NTRS)

    Cruden, Brett A.

    2014-01-01

    This paper reports on the measurement of radiative heating for shock heated flows which simulate conditions for Mars and Earth entries. Radiation measurements are made in NASA Ames' Electric Arc Shock Tube at velocities from 3-15 km/s in mixtures of N2/O2 and CO2/N2/Ar. The technique and limitations of the measurement are summarized in some detail. The absolute measurements will be discussed in regards to spectral features, radiative magnitude and spatiotemporal trends. Via analysis of spectra it is possible to extract properties such as electron density, and rotational, vibrational and electronic temperatures. Relaxation behind the shock is analyzed to determine how these properties relax to equilibrium and are used to validate and refine kinetic models. It is found that, for some conditions, some of these values diverge from non-equilibrium indicating a lack of similarity between the shock tube and free flight conditions. Possible reasons for this are discussed.

  20. Coordinated weather balloon solar radiation measurements during a solar eclipse.

    PubMed

    Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

    2016-09-28

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. PMID:27550757

  1. Coordinated weather balloon solar radiation measurements during a solar eclipse

    PubMed Central

    2016-01-01

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes. This article is part of the themed issue ‘Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse’. PMID:27550757

  2. Coordinated weather balloon solar radiation measurements during a solar eclipse.

    PubMed

    Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

    2016-09-28

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  3. Satellite data sets for the atmospheric radiation measurement (ARM) program

    SciTech Connect

    Shi, L.; Bernstein, R.L.

    1996-04-01

    This abstract describes the type of data obtained from satellite measurements in the Atmospheric Radiation Measurement (ARM) program. The data sets have been widely used by the ARM team to derive cloud-top altitude, cloud cover, snow and ice cover, surface temperature, water vapor, and wind, vertical profiles of temperature, and continuoous observations of weather needed to track and predict severe weather.

  4. Temperature measurements using multicolor pyrometry in thermal radiation heating environments

    SciTech Connect

    Fu, Tairan; Liu, Jiangfan; Duan, Minghao; Zong, Anzhou

    2014-04-15

    Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100–2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700–1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.

  5. Temperature measurements using multicolor pyrometry in thermal radiation heating environments.

    PubMed

    Fu, Tairan; Liu, Jiangfan; Duan, Minghao; Zong, Anzhou

    2014-04-01

    Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100-2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700-1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments. PMID:24784642

  6. Radiation internal exposure measurements archiving system (REMAS).

    PubMed

    Bitar, A; Maghrabi, M

    2013-12-01

    This paper describes a personal-computer-based software, REMAS, which helps users to estimate intake activity and resulting internal doses for all radionuclides existing in (International Commission on Radiological Protection) ICRP 78 and other important elements. In addition to its use in internal dose calculations, it facilitates management of data of monitored persons who are occupationally exposed to unsealed radioactive substances. Furthermore, REMAS offers the possibility to generate different reports of results. The program is suitable for laboratories working in the field of assessment of occupational intake and also for users of radioactive material who are routinely monitored. REMAS, which is bilingual program (English and Arabic), was built with GUI environment and was developed using Microsoft FoxPro. It runs on Microsoft Windows XP operating systems.

  7. Radiation internal exposure measurements archiving system (REMAS).

    PubMed

    Bitar, A; Maghrabi, M

    2013-12-01

    This paper describes a personal-computer-based software, REMAS, which helps users to estimate intake activity and resulting internal doses for all radionuclides existing in (International Commission on Radiological Protection) ICRP 78 and other important elements. In addition to its use in internal dose calculations, it facilitates management of data of monitored persons who are occupationally exposed to unsealed radioactive substances. Furthermore, REMAS offers the possibility to generate different reports of results. The program is suitable for laboratories working in the field of assessment of occupational intake and also for users of radioactive material who are routinely monitored. REMAS, which is bilingual program (English and Arabic), was built with GUI environment and was developed using Microsoft FoxPro. It runs on Microsoft Windows XP operating systems. PMID:23782905

  8. Validating CERES Radiative Fluxes in the Arctic with Airborne Radiative Flux Measurements from the ARISE Campaign

    NASA Astrophysics Data System (ADS)

    Corbett, J.; Bucholtz, A.; Kato, S.; Rose, F. G.; Smith, W. L., Jr.

    2015-12-01

    The Clouds and the Earth's Radiant Energy System (CERES) instruments on board NASA's Terra, Aqua, and Soumi-NPP satellites provide the only measurements of reflected solar shortwave and emitted longwave radiative flux over the Arctic. Various methods have shown the uncertainty of CERES fluxes over sea ice to be higher than other scene types. However validation against an independent radiative flux measurement has never been attempted. We present here an attempt to better quantify the uncertainty of time-and-space averaged CERES flux measurements using airborne measurements from the Arctic Radiation - IceBridge Sea Ice Experiment (ARISE). The ARISE campaign took place during September of 2014 based out of Fairbanks, Alaska, with most of the measurements taken in the vicinity of the sea ice edge between 125°W and 150°W, and 71°N to 77°N. For six of the flights, measurements were taken in a lawnmower type pattern over either 100 x 200 km box regions at a constant altitude of >6 km, or 100 x 100 km box regions at an altitude of between 200 m to 500 m. They were designed to resemble the CERES Level 3 spatial averaging grids, and were located and timed to coincide with a high number of CERES overpasses. On board the aircraft were a set of upward and downward facing shortwave and longwave broadband radiometers (BBR), along with other instruments measuring meteorological conditions and cloud properties. We have compared the broadband radiative fluxes from BBR with those from CERES for the three days where the aircraft was flying the high altitude pattern. We use the Fu-Liou radiative transfer model to account for differences in the measurement altitude between BBR and CERES. We will present results of the comparisons between the computed fluxes and the measured longwave and shortwave radiative fluxes.

  9. Evaporation and radiation measurements at Salton Sea, California

    USGS Publications Warehouse

    Sturrock, Alex M.

    1978-01-01

    Evaporation from Salton Sea, Calif. was computed for a 539-day period between duly 14, 1967, and January 2, 1969, by use of energy-budget, mass-transfer, and water-budget methods. The total evaporation computed by the three methods agreed within 5 percent. For computing evaporation by the mass-transfer method, vapor pressure measured at raft stations on the sea was considered to be more representative of the conditions over the sea than vapor pressure measured at land stations. The values of heat transfer to and from the bed were used in energy-budget computations. The inclusion of these heat transfer values improved the correlation of evaporation computed by the energy-budget and water-budget methods. Monthly evaporation computed by the energy budget method for 1968 showed that the Salton Sea exhibited a double-wave evaporation similar to that of oceans in the same latitude. Weekly and monthly comparisons were made to determine if radiation measured by the flat-plate radiometer is seasonally biased. Weekly totals of radiation from three flat-plate radiometers were compared to values of a Cummings Radiation Integrator. Monthly totals of radiation for each of the two types of instruments were compared to an empirical method for determining radiation. These comparisons indicate that the measurements of radiation by the flat-plate radiometer are not seasonally biased, and that the Cummings Radiation Integrator gives reliable measurements of radiation for periods as short as 1 week. The net incoming radiation was measured at three stations around the Salton Sea. The areal variation was less than 1 percent on an annual basis and the largest weekly variation was less than 6 percent. An empirical mass-transfer coefficient, N, was determined from energy-budget measurements. The value of this coefficient to give evaporation in inches per day is 0.00245 when the windspeed is expressed in miles per hour and vapor pressure is expressed in millibars. The coefficient is valid

  10. Measurement of microwave radiation from electron beam in the atmosphere

    NASA Astrophysics Data System (ADS)

    Ohta, I. S.; Akimune, H.; Fukushima, M.; Ikeda, D.; Inome, Y.; Matthews, J. N.; Ogio, S.; Sagawa, H.; Sako, T.; Shibata, T.; Yamamoto, T.

    2016-02-01

    We report the use of an electron light source (ELS) located at the Telescope Array Observatory in Utah, USA, to measure the isotropic microwave radiation from air showers. To simulate extensive air showers, the ELS emits an electron beam into the atmosphere and a parabola antenna system for the satellite communication is used to measure the microwave radiation from the electron beam. Based on this measurement, an upper limit on the intensity of a 12.5 GHz microwave radiation at 0.5 m from a 1018 eV air shower was estimated to be 3.96×10-16 W m-2 Hz-1 with a 95% confidence level.

  11. A molecular fraction method for measuring personnel radiation doses

    NASA Astrophysics Data System (ADS)

    Fadel, M. A.; Khalil, W. A.; Krodja, R. P.; Sheta, N.; Abd El-Baset, M. S.

    1987-02-01

    This work represents a development in fast and albedo neutron and gamma ray dosimetry, using cellulose nitrate, as a tissue equivalent material, in which radiation damage was registered. The changes in molecular fractions of the polymer were measured after irradiation with neutron fluences from a 252Cf source in the range 10 5-10 10 n/cm 2 and gamma doses in the range 10 -4-10 -1 Gy through the use of gel filtration chromatography. Effects of irradiation on phantom, phantom to dosimeter distance, phantom thickness and storage at extreme environmental conditions were studied on the detector response and readout. The results showed that main chain scission followed by formation of new molecular configurations is the predominant effect of radiation on the polymer. The method enables measurements of neutron fluences and gamma doses in mixed radiation fields. Empirical formulae for calculating the absorbed dose from the measured changes in molecular fraction intensities are given.

  12. Radiating Shock Measurements in the Z-Pinch Dynamic Hohlraum

    SciTech Connect

    Rochau, G. A.; Bailey, J. E.; Chandler, G. A.; Lemke, R. W.; Peterson, K. J.; Slutz, S. A.; Maron, Y.; Fisher, D. V.; Fisher, V. I.; Stambulchik, E.; Dunham, G. S.; MacFarlane, J. J.; Schroen, D. G.

    2008-03-28

    The Z-pinch dynamic hohlraum is an x-ray source for high energy-density physics studies that is heated by a radiating shock to radiation temperatures >200 eV. The time-dependent 300-400 eV electron temperature and 15-35 mg/cc density of this shock have been measured for the first time using space-resolved Si tracer spectroscopy. The shock x-ray emission is inferred from these measurements to exceed 50 TW, delivering >180 kJ to the hohlraum.

  13. Shock Layer Radiation Measurements and Analysis for Mars Entry

    NASA Technical Reports Server (NTRS)

    Bose, Deepak; Grinstead, Jay Henderson; Bogdanoff, David W.; Wright, Michael J.

    2009-01-01

    NASA's In-Space Propulsion program is supporting the development of shock radiation transport models for aerocapture missions to Mars. A comprehensive test series in the NASA Antes Electric Arc Shock Tube facility at a representative flight condition was recently completed. The facility optical instrumentation enabled spectral measurements of shocked gas radiation from the vacuum ultraviolet to the near infrared. The instrumentation captured the nonequilibrium post-shock excitation and relaxation dynamics of dispersed spectral features. A description of the shock tube facility, optical instrumentation, and examples of the test data are presented. Comparisons of measured spectra with model predictions are also made.

  14. Measuring activity in ant colonies

    NASA Astrophysics Data System (ADS)

    Noda, C.; Fernández, J.; Pérez-Penichet, C.; Altshuler, E.

    2006-12-01

    Ants, as paradigm of social insects, have become a recurrent example of efficient problem solvers via self-organization. In spite of the simple behavior of each individual, the colony as a whole displays "swarm intelligence:" the organization of ant trails for foraging is a typical output of it. But conventional techniques of observation can hardly record the amount of data needed to get a detailed understanding of self-organization of ant swarms in the wild. Here we are presenting a measurement system intended to monitor ant activity in the field comprising massive data acquisition and high sensitivity. A central role is played by an infrared sensor devised specifically to monitor relevant parameters to the activity of ants through the exits of the nest, although other sensors detecting temperature and luminosity are added to the system. We study the characteristics of the activity sensor and its performance in the field. Finally, we present massive data measured at one exit of a nest of Atta insularis, an ant endemic to Cuba, to illustrate the potential of our system.

  15. Quantifying reflectance anisotropy of photosynthetically active radiation in grasslands

    SciTech Connect

    Middleton, E.M. )

    1992-11-30

    This work is part of the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE), an international land-surface-atmosphere experiment aimed at improving the way climate models represent energy, water, heat, and carbon exchanges, and improving the utilization of satellite based remote sensing to monitor such parameters. This paper reports on a study to quantify the reflectance anisotropy of the photosynthetically active radiation (PAR) for grasslands. PAR falls in the wavelength range 0.4 to 0.7[mu]m. The study looks at the variation of PAR with illumination and vegetative canopy conditions. It uses bidirectional reflectance distribution function data, and measures of anisotropy derived from reflectance factor and reflectance fraction data to aid in the analysis. The data used for this analysis came from an intense effort mounted to measure diurnal changes in the anisotropy of surface reflectance from prairie grassland as a function of the vegetative canopy.

  16. Listing of solar radiation measuring equipment and glossary

    NASA Technical Reports Server (NTRS)

    Carter, E. A.; Greenbaum, S. A.; Patel, A. M.

    1976-01-01

    An attempt is made to list and provide all available information about solar radiation measuring equipment which are being manufactured and are available on the market. The list is in tabular form and includes sensor type, response time, cost data and comments for each model. A cost code is included which shows ranges only.

  17. Atmospheric radiation measurement program facilities newsletter, September 2002.

    SciTech Connect

    Holdridge, D. J.

    2002-10-02

    This Atmospheric radiation measurement program facilities newsletter covers the following topics: The Raman lidar at the SGP central facility is receiving upgrades to its environmental controls; The instrument tower at Okmulgee State Park is receiving upgrades to prevent Turkey Vultures from roosting on the booms.

  18. Evaporation and radiation measurements at Salton Sea, California

    USGS Publications Warehouse

    Sturrock, Alex M.

    1977-01-01

    Evaporation from the Salton Sea, Calif., was computed for a 539-day period between July 14, 1967, and January 2, 1969, by use of energy-budget, mass-transfer, and water budget methods. The total evaporation computed by the three methods agreed within 5 percent. The values of heat transfer to and from the bed were used in the energy-budget computations. Monthly evaporation computed by the energy-budget method for 1968 showed that the Salton Sea exhibited a double wave evaporation similar to that of oceans in the same latitude. Weekly and montly comparisons were made to determine if radiation measured by the flat-plate radiometer is seasonally biased. These comparisons indicate that the measurements of radiation by the flat-plate radiometer are not seasonally biased, and that the Cummings Radiation Integrator gives reliable measurements of radiation for periods as short as 1 week. An empirical mass-transfer coefficient, N, as determined from energy-budget measurements. The value of this coefficient to give evaporation in inches per day is 0.00245 when the windspeed is expressed in miles per hour and the vapor pressure expressed in millibars. (Woodard-USGS)

  19. Radiation profiles measured through clouds using a return glider radiosonde

    NASA Astrophysics Data System (ADS)

    Kräuchi, Andreas; Philipona, Rolf; Kivi, Rigel

    2016-04-01

    With new and improved radiation sensors in a small glider aircraft vertical flights through clouds have been conducted. This new Return Glider Radiosonde (RG-R) is lifted up with double balloon technique to keep the radiation instruments as horizontal as possible during ascent. The RG-R is equipped with a routine radiosonde to transmit the data to a ground station and an autopilot to fly the glider radiosonde back to the launch site, where it lands autonomous with a parachute. The RG-R was successfully tested and deployed for tropospheric and stratospheric radiation measurements up to 30 hPa (24 km altitude) at the GRUAN sites Payerne (Switzerland) and Sodankylä (Finland). Radiation profiles and the radiation budget through the atmosphere during different daytimes and under cloud-free and cloudy situations will be shown in relation to temperature and humidity at the surface and in the atmosphere. The RG-R flight characteristics and new measurement possibilities will also be discussed.

  20. Interpretation of TEPC Measurements in Space Flights for Radiation Monitoring

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Nikjoo, Hooshang; Dicello, John F.; Pisacane, Vincent; Cucinotta, Francis A.

    2007-01-01

    For the proper interpretation of radiation data measured in space, the results of integrated radiation transport models were compared with the tissue equivalent proportional counter (TEPC) measurements. TEPC is a simple, time-dependent approach to radiation monitoring for astronauts on board the International Space Station. Another and a newer approach to microdosimetry is the use of silicon-on-insulator (SOI) technology launched on the MidSTAR-1 mission in low Earth orbit (LEO). In the radiation protection practice, the average quality factor of a radiation field is defined as a function of linear energy transfer (LET), Qave(LET). However, TEPC measures the average quality factor as a function of the lineal energy y, Qave(y), defined as the average energy deposition in a volume divided by the average chord length of the volume. The deviation of y from LET is caused by energy straggling, delta-ray escape or entry, and nuclear fragments produced in the detector volume. The response distribution functions of the wall-less and walled TEPCs were calculated from Monte-Carlo track simulations. Using an integrated space radiation model (which includes the transport codes HZETRN and BRYNTRN, and the quantum nuclear interaction model QMSFRG) and the resultant response distribution functions from Monte-Carlo track simulations, we compared model calculations with the walled-TEPC measurements from NASA missions in LEO and made predictions for the lunar and the Mars missions. Good agreement was found for Qave(y) between the model and measured spectra from past NASA missions. The Qave(y) values for the trapped or the solar protons ranged from 1.9-2.5. This over-estimates the Qave(LET) values which ranged from 1.4-1.6. Both quantities increase with shield thickness due to nuclear fragmentation. The Qave(LET) for the complete GCR spectra was found to be 3.5-4.5, while flight TEPCs measured 2.9-3.4 for Qave(y). The GCR values are decreasing with the shield thickness. Our analysis

  1. Status of radiation damage measurements in room temperature semiconductor radiation detectors

    SciTech Connect

    Franks, L.A.; James, R.B.

    1998-04-01

    The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI{sub 2}) is reviewed for the purpose of determining their applicability to space applications. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10{sup 10} p/cm{sup 2} and significant bulk leakage after 10{sup 12} p/cm{sup 2}. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 {times} 10{sup 9} p/cm{sup 2} in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum neutrons after fluences up to 10{sup 10} n/cm{sup 2}, although activation was evident. CT detectors show resolution losses after fluences of 3 {times} 10{sup 9} p/cm{sup 2} at 33 MeV for chlorine-doped detectors. Indium doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 {times} 10{sup 10} n/cm{sup 2}. Mercuric iodide has been studied with intermediate energy protons (10 to 33 MeV) at fluences up to 10{sup 12} p/cm{sup 2} and with 1.5 GeV protons at fluences up to 1.2 {times} 10{sup 8} p/cm{sup 2}. Neutron exposures at 8 MeV have been reported at fluences up to 10{sup 15} n/cm{sup 2}. No radiation damage was found under these irradiation conditions.

  2. Lens transmission measurement for an absolute radiation thermometer

    SciTech Connect

    Hao, X.; Yuan, Z.; Lu, X.

    2013-09-11

    The lens transmission for the National Institute of Metrology of China absolute radiation thermometer is measured by a hybrid method. The results of the lens transmission measurements are 99.002% and 86.792% for filter radiometers with center wavelengths 633 nm and 900 nm, respectively. These results, after correcting for diffraction factors and the size-of-source effect when the lens is incorporated within the radiometer, can be used for measurement of thermodynamic temperature. The expanded uncertainty of the lens transmission measurement system has been evaluated. It is 1.3×10{sup −3} at 633 nm and 900 nm, respectively.

  3. Measurement of parameters in Indus-2 synchrotron radiation source.

    PubMed

    Ghodke, A D; Husain, Riyasat; Kumar, Pradeep; Yadav, Surendra; Puntambekar, T A

    2012-10-01

    The paper presents the measurement of optics parameters in Indus-2 synchrotron radiation source, which include betatron tune, beta function, dispersion function, natural chromaticity, corrected chromaticity, central RF frequency, momentum compaction factor, and linear betatron coupling. Two methods were used for beta function measurement; a conventional quadrupole scan method and a method using the fitting of the orbit response matrix. A robust Levenberg-Marquardt algorithm was used for nonlinear least square fitting of the orbit response matrix. In this paper, detailed methods for the parameter measurements are described. The measured results are discussed and compared with the theoretical values obtained using accelerator simulation code Accelerator Toolbox in MATLAB.

  4. Measuring Radiofrequency and Microwave Radiation from Varying Signal Strengths

    NASA Technical Reports Server (NTRS)

    Davis, Bette; Gaul, W. C.

    2007-01-01

    This viewgraph presentation discusses the process of measuring radiofrequency and microwave radiation from various signal strengths. The topics include: 1) Limits and Guidelines; 2) Typical Variable Standard (IEEE) Frequency Dependent; 3) FCC Standard 47 CFR 1.1310; 4) Compliance Follows Unity Rule; 5) Multiple Sources Contribute; 6) Types of RF Signals; 7) Interfering Radiations; 8) Different Frequencies Different Powers; 9) Power Summing - Peak Power; 10) Contribution from Various Single Sources; 11) Total Power from Multiple Sources; 12) Are You Out of Compliance?; and 13) In Compliance.

  5. Dosimetry of occupational exposure to RF radiation: Measurements and methods

    SciTech Connect

    Tofani, S.; Agnesod, G.

    1987-06-01

    Workers engaged in the operation of RF industrial devices are exposed to electromagnetic radiation in the near-field zone that is characterized by high spatial and temporal gradients. This paper is concerned with measurement methods and data analyses which allow the evaluation of the electromagnetic field exposure of the operator together with the SAR induced by near-field exposure accounting for the spatial and temporal variations. These methods are applied to the theoretical dosimetry of the occupational exposure to RF radiation emitted by 27.12-MHz plastic sealers. The data obtained are compared with those deducible through a conventional wide-band isotropic field meter.

  6. Measurement of the radiative transport properties of reticulated alumina foams

    SciTech Connect

    Hale, M.J.; Bohn, M.S.

    1992-12-01

    This paper presents a method for determining radiative transport properties of reticulated materials. The method has both experimental and analytical components. A polar nephelometer is used to measure the scattering profile of a sample of the reticulated material. The results of a Monte Carlo simulation of the experiment are then combined with the experimental results to give the scatter albedo and extinction coefficient. This paper presents the results of using this method to determine the radiative transport properties of four different porosities (10, 20, 30, 65 pores per inch) of cylindrical reticulated alumina samples ranging in thickness form 0.5 inches to 2. 5 inches.

  7. Probing Radiation Damage in Plutonium Alloys with Multiple Measurement Techniques

    SciTech Connect

    McCall, S K; Fluss, M J; Chung, B W

    2010-04-21

    A material subjected to radiation damage will usually experience changes in its physical properties. Measuring these changes in the physical properties provides a basis to study radiation damage in a material which is important for a variety of real world applications from reactor materials to semiconducting devices. When investigating radiation damage, the relative sensitivity of any given property can vary considerably based on the concentration and type of damage present as well as external parameters such as the temperature and starting material composition. By measuring multiple physical properties, these differing sensitivities can be leveraged to provide greater insight into the different aspects of radiation damage accumulation, thereby providing a broader understanding of the mechanisms involved. In this report, self-damage from {alpha}-particle decay in Pu is investigated by measuring two different properties: magnetic susceptibility and resistivity. The results suggest that while the first annealing stage obeys second order chemical kinetics, the primary mechanism is not the recombination of vacancy-interstitial close pairs.

  8. Atmospheric radiation measurement program facilities newsletter, September 2001.

    SciTech Connect

    Holdridge, D. J.

    2001-10-10

    Our Changing Climate--Is our climate really changing? How do we measure climate change? How can we predict what Earth's climate will be like for generations to come? One focus of the Atmospheric Radiation Measurement (ARM) Program is to improve scientific climate models enough to achieve reliable regional prediction of future climate. According to the Environmental Protection Agency (EPA), the global mean surface temperature has increased by 0.5-1.0 F since the late 19th century. The 20th century's 10 warmest years all occurred in the last 15 years of the century, with 1998 being the warmest year of record. The global mean surface temperature is measured by a network of temperature-sensing instruments distributed around the world, including ships, ocean buoys, and weather stations on land. The data from this network are retrieved and analyzed by various organizations, including the National Aeronautics and Space Administration, the National Oceanic and Atmospheric Administration, and the World Meteorological Organization. Worldwide temperature records date back to 1860. To reconstruct Earth's temperature history before 1860, scientists use limited temperature records, along with proxy indicators such as tree rings, pollen records, and analysis of air frozen in ancient ice. The solar energy received from the sun drives Earth's weather and climate. Some of this energy is reflected and filtered by the atmosphere, but most is absorbed by Earth's surface. The absorbed solar radiation warms the surface and is re-radiated as heat energy into the atmosphere. Some atmospheric gases, called greenhouse gases, trap some of the re-emitted heat, keeping the surface temperature regulated and suitable for sustaining life. Although the greenhouse effect is natural, some evidence indicates that human activities are producing increased levels of some greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Scientists believe that the combustion of fossil fuels is

  9. Measurement of Radiation Belt Partcles by MDS-1 Onboard SEDA

    NASA Astrophysics Data System (ADS)

    Matsumoto, H.; Koshiishi, H.; Goka, T.

    The Space Environment Data Acquisition Equipment (SEDA) is on board the Mission Demonstration Test Satellite-1 (MDS-1) to measure the radiation environment, which was launched into geo-stationary transfer orbit (GTO) on February 4, 2002 with an apogee of about 35,700km, a perigee of about 500 km and an inclination of about 28.5 degrees. SEDA consists of the four instruments. Standard Dose Monitor monitors the electron and proton flux. Dosimeter measures the integrated radiation dose at fifty-six points of the satellite. Heavy Ion Telescope monitors the flux of heavy ions from He to Fe. Magnetometer measures the magnetic field in the magnetosphere. In this paper are described first results and comparison with the ISO standard model for the space environment

  10. Measurement of emission from a radiatively collapsed shock

    NASA Astrophysics Data System (ADS)

    Visco, A.; Drake, R. P.; Grosskopf, M. J.; Gjeci, N.; Gillespie, R. S.; Shultz, J. D.; Campbell, D. A.; Human, J.

    2007-11-01

    Radiatively collapsed shocks are systems in which radiation transport causes the shock to ``collapse'' or compress to high densities. Such shocks are present in supernova remnants, passing through interstellar medium, and other such astrophysical systems. With the advent of large laser facilities, conditions can be created so that radiativly collapsed shocks can be studied in quantitative way. Recent experiments have been preformed on the Omega laser at the Laboratory for Laser Energetics to study the dynamics of these shocks. Measurements of radiative emission from the collapsed shock and precursor region have been made using a streaked optical pyrometer from which the temperature of the system can be calculated. Details of the experiment and results will be discussed. This research was sponsored by the NNSA through DOE Research Grants DE-FG52-07NA28058, DE-FG52-04NA00064, and other grants and contracts.

  11. Recent measurements for hadrontherapy and space radiation: nuclear physics.

    PubMed

    Miller, J

    2001-01-01

    The particles and energies commonly used for hadron therapy overlap the low end of the charge and energy range of greatest interest for space radiation applications, Z=1-26 and approximately 100-1000 MeV/nucleon. It has been known for some time that the nuclear interactions of the incident ions must be taken into account both in treatment planning and in understanding and addressing the effects of galactic cosmic ray ions on humans in space. Until relatively recently, most of the studies of nuclear fragmentation and transport in matter were driven by the interests of the nuclear physics and later, the hadron therapy communities. However, the experimental and theoretical methods and the accelerator facilities developed for use in heavy ion nuclear physics are directly applicable to radiotherapy and space radiation studies. I will briefly review relevant data taken recently at various accelerators, and discuss the implications of the measurements for radiotherapy, radiobiology and space radiation research.

  12. Atmospheric Radiation Measurement Program facilities newsletter, April 2000

    SciTech Connect

    Sisterson, D. L.

    2000-05-05

    This issue of the Atmospheric Radiation Measurement Program (ARM Program) monthly newsletter is about the ARM Program goal to improve scientific understanding of the interactions of sunlight (solar radiation) with the atmosphere, then incorporate this understanding into computer models of climate change. To model climate accurately all around the globe, a variety of data must be collected from many locations on Earth. For its Cloud and Radiation Testbed (CART) sites, ARM chose locations in the US Southern Great Plains, the North Slope of Alaska, and the Tropical Western Pacific Ocean to represent different climate types around the world. In this newsletter they consider the North Slope of Alaska site, with locations at Barrow and Atqasuk, Alaska.

  13. Polarimeter measures sea state characteristics using emitted infrared radiation

    NASA Technical Reports Server (NTRS)

    Egan, W. G.; Hilgeman, T.

    1977-01-01

    An infrared polarimeter, capable of operating between 1 and 12 micrometers wavelength has been used to measure the polarization of emitted radiation from the sea. The observed polarization at 10.6 micrometers from a smooth sea was found to be positive, indicating the dominance of reflected infrared sky radiation over the emitted. With the appearance of waves, the percent polarization increased, as expected, for a zenith angle well above the Brewster angle for water. This is qualitatively in accordance with a model presented to explain the behavior. Initial analyses indicate that the polarized components of the sea's emitted and reflected radiation are affected by type and direction of waves, angle of viewing, and foam. The effects of variations in these parameters require further delineation. The infrared polarimetric technique appears to be a novel new passive method for remote monitoring of waves.

  14. Recent measurements for hadrontherapy and space radiation: nuclear physics

    NASA Technical Reports Server (NTRS)

    Miller, J.

    2001-01-01

    The particles and energies commonly used for hadron therapy overlap the low end of the charge and energy range of greatest interest for space radiation applications, Z=1-26 and approximately 100-1000 MeV/nucleon. It has been known for some time that the nuclear interactions of the incident ions must be taken into account both in treatment planning and in understanding and addressing the effects of galactic cosmic ray ions on humans in space. Until relatively recently, most of the studies of nuclear fragmentation and transport in matter were driven by the interests of the nuclear physics and later, the hadron therapy communities. However, the experimental and theoretical methods and the accelerator facilities developed for use in heavy ion nuclear physics are directly applicable to radiotherapy and space radiation studies. I will briefly review relevant data taken recently at various accelerators, and discuss the implications of the measurements for radiotherapy, radiobiology and space radiation research.

  15. Measurements of radiation fields around high-energy proton accelerators.

    PubMed

    Agosteo, Stefano; Silari, Marco

    2005-01-01

    Monitoring of ionising radiation around high-energy particle accelerators is a difficult task due to the complexity of the radiation field, which is made up of neutrons, charged hadrons, muons, photons and electrons, with energy spectra extending over a wide energy range. The dose-equivalent outside a thick shield is mainly owing to neutrons, with some contribution from photons and, to a minor extent, the other particles. Neutron dosimetry and spectrometry are thus of primary importance to correctly evaluate the exposure of personnel. This paper reviews the relevant techniques and instrumentation employed for monitoring radiation fields around high-energy proton accelerators, with particular emphasis on the recent development to increase the response of neutron measuring devices > 20 MeV. Rem-counters, pressurised ionisation chambers, superheated emulsions, tissue-equivalent proportional counters and Bonner sphere spectrometers are discussed. PMID:16604662

  16. Design of a differential radiometer for atmospheric radiative flux measurements

    SciTech Connect

    LaDelfe, P.C.; Weber, P.G.; Rodriguez, C.W.

    1994-11-01

    The Hemispherical Optimized NEt Radiometer (HONER) is an instrument under development at the Los Alamos National Laboratory for deployment on an unmanned aerospace vehicle as part of the Atmospheric Radiation Measurements (ARM/UAV) program. HONER is a differential radiometer which will measure the difference between the total upwelling and downwelling fluxes and is intended to provide a means of measuring the atmospheric radiative flux divergence. Unlike existing instruments which measure the upwelling and downwelling fluxes separately, HONER will achieve an optical difference by chopping the two fluxes alternately onto a common pyroelectric detector. HONER will provide data resolved into two spectral bands; one covering the solar dominated region from less than 0.4 micrometer to approximately 4.5 micrometers and the other covering the region from approximately 4.5 micrometers to greater than 50 micrometers, dominated by thermal radiation. The means of separating the spectral regions guarantees seamless summation to calculate the total flux. The fields-of-view are near-hemispherical, upward and downward. The instrument can be converted, in flight, from the differential mode to absolute mode, measuring the upwelling and downwelling fluxes separately and simultaneously. The instrument also features continuous calibration from on-board sources. We will describe the design and operation of the sensor head and the on-board reference sources as well as the means of deployment.

  17. Radiation measured with passive dosimeters in low Earth orbit

    NASA Astrophysics Data System (ADS)

    Zhou, D.; Semones, E.; Gaza, R.; Weyland, M.

    begin center Radiation Measured with Passive Dosimeters in Low Earth Orbit end center begin center D Zhou 1 2 E Semones 1 R Gaza 1 2 M Weyland 1 end center begin center 1 Johnson Space Center - NASA 2101 Nasa Road 1 Houston 77058 USA end center begin center 2 Universities Space Research Association 2101 Nasa Parkway Houston 77058 USA end center begin center Abstract end center The linear energy transfer LET of particles in low Earth orbit LEO is extended from sim 0 1 to sim 1000 keV mu m water The best passive dosimeters for the radiation measurement are thermoluminescence dosimeters TLDs or optically stimulated luminescence dosimeters OSLDs for low LET and CR-39 plastic nuclear track detectors PNTDs for high LET Radiation quantities fluence absorbed dose dose equivalent and quality factor were measured with the passive dosimeters composed of TLDs OSLDs and CR-39 PNTDs for STS-114 mission This paper introduces the operation principles for TLDs OSLDs and CR-39 PNTDs describes the method to combine the results measured by TLDs OSLDs and CR-39 PNTDs and presents the results measured by different dosimeters for different LET band and that combined for all LET

  18. Optical measurements of plastic (polyimide) hollow waveguides for IR radiation

    NASA Astrophysics Data System (ADS)

    Croitoru, Nathan I.; Inberg, Alexandra; Oksman, Mark; Ben-David, M.

    1997-12-01

    Hollow waveguides for infrared radiation are suitable for high power radiation and large interval of wavelengths. This has enabled to begin its preparation for several practical applications in medicine which are already investigated. One of the types of these waveguides is made from plastic (teflon) tubes and several papers were published in this field. Although the Teflon waveguides have several important advantages (high flexibility and biological suitability) for application in medicine, there are also difficulties in achieving low attenuation (low radiation losses), of the transmitted radiation, which is limiting their applications. One of the main reasons of the large losses of the transmitted radiation through these waveguides is the relative large roughness of the internal wall of the tubes which produce scattering of the incident radiation. Several attempts to reduce the roughness have given only a limited improvement since the internal wall of the Teflon tube is not easy to polish (the needed average roughness is less than 10 nm). In previous papers we have reported first results obtained in developing a new type of hollow waveguide for infrared made from polyimide which is a type of plastic with high melting temperature and which can be prepared with very flat surface roughness, less than 10 nm. In this paper we shall present new results of a study made for developing this type of plastic hollow waveguide. The attenuation was reduced to values less than 1 dB. Data about the process of etching for decreasing the roughness of the internal wall of polyimide tube and new methods of deposition of high adhesive and minimal roughness of the Ag and AgI guiding layers will be presented. Results of measurements of attenuation as a function of bending radius, coupled power and time of transmitted radiation will be shown and discussed. New type of dependence of attenuation on bending due to the mechanical properties of the polyimide tubes will be shown and discussed.

  19. Optical measurements of plastic (polyimide) hollow waveguides for IR radiation

    NASA Astrophysics Data System (ADS)

    Croitoru, Nathan I.; Inberg, Alexandra; Oksman, Mark; Ben-David, M.

    1998-01-01

    Hollow waveguides for infrared radiation are suitable for high power radiation and large interval of wavelengths. This has enabled to begin its preparation for several practical applications in medicine which are already investigated. One of the types of these waveguides is made from plastic (teflon) tubes and several papers were published in this field. Although the Teflon waveguides have several important advantages (high flexibility and biological suitability) for application in medicine, there are also difficulties in achieving low attenuation (low radiation losses), of the transmitted radiation, which is limiting their applications. One of the main reasons of the large losses of the transmitted radiation through these waveguides is the relative large roughness of the internal wall of the tubes which produce scattering of the incident radiation. Several attempts to reduce the roughness have given only a limited improvement since the internal wall of the Teflon tube is not easy to polish (the needed average roughness is less than 10 nm). In previous papers we have reported first results obtained in developing a new type of hollow waveguide for infrared made from polyimide which is a type of plastic with high melting temperature and which can be prepared with very flat surface roughness, less than 10 nm. In this paper we shall present new results of a study made for developing this type of plastic hollow waveguide. The attenuation was reduced to values less than 1 dB. Data about the process of etching for decreasing the roughness of the internal wall of polyimide tube and new methods of deposition of high adhesive and minimal roughness of the Ag and AgI guiding layers will be presented. Results of measurements of attenuation as a function of bending radius, coupled power and time of transmitted radiation will be shown and discussed. New type of dependence of attenuation on bending due to the mechanical properties of the polyimide tubes will be shown and discussed.

  20. A Comparison of EAST Shock-Tube Radiation Measurements with a New Air Radiation Model

    NASA Technical Reports Server (NTRS)

    Johnston, Christopher O.

    2008-01-01

    This paper presents a comparison between the recent EAST shock tube radiation measurements (Grinstead et al., AIAA 2008-1244) and the HARA radiation model. The equilibrium and nonequilibrium radiation measurements are studied for conditions relevant to lunar-return shock-layers; specifically shock velocities ranging from 9 to 11 kilometers per second at initial pressures of 0.1 and 0.3 Torr. The simulated shock-tube flow is assumed one-dimensional and is calculated using the LAURA code, while a detailed nonequilibrium radiation prediction is obtained in an uncoupled manner from the HARA code. The measured and predicted intensities are separated into several spectral ranges to isolate significant spectral features, mainly strong atomic line multiplets. The equations and physical data required for the prediction of these strong atomic lines are reviewed and their uncertainties identified. The 700-1020 nm wavelength range, which accounts for roughly 30% of the radiative flux to a peak-heating lunar return shock-layer, is studied in detail and the measurements and predictions are shown to agree within 15% in equilibrium. The plus or minus 1.5% uncertainty on the measured shock velocity is shown to cause up to a plus or minus 30% difference in the predicted radiation. This band of predictions contains the measured values in almost all cases. For the highly nonequilibrium 0.1 Torr cases, the nonequilibrium radiation peaks are under-predicted by about half. This under-prediction is considered acceptable when compared to the order-of-magnitude over-prediction obtained using a Boltzmann population of electronic states. The reasonable comparison in the nonequilibrium regions provides validation for both the non-Boltzmann modeling in HARA and the thermochemical nonequilibrium modeling in LAURA. The N2 (+)(1-) and N2(2+) molecular band systems are studied in the 290 480 nm wavelength range for both equilibrium and nonequilibrium regimes. The non-Boltzmann rate models for these

  1. Direct measurements of radiative capture reactions with DRAGON

    NASA Astrophysics Data System (ADS)

    Christian, Gregory

    2015-10-01

    Direct measurements of radiative proton and alpha capture reactions are crucial for understanding nucleosynthesis in a variety of astrophysical environments, including classical novae, supernovae, X-Ray bursts, and quiescent stellar burning. Often the most important reactions have very low cross sections or involve unstable targets, making laboratory measurements extremely challenging. The detector of recoils and gammas of nuclear reactions (DRAGON) at TRIUMF is a recoil mass separator designed to measure radiative capture reactions in inverse kinematics, with beam suppression factors as high as 1016. When combined with the intense radioactive beams available at the ISAC-I facility, DRAGON's capabilities are unique and world-leading. In this talk, I will give a brief technical overview of DRAGON before presenting results from recent experiments. Some highlights include the first-ever direct measurement of 38K(p , γ) 39Ca, a crucial reaction for determining the endpoint of nova nucleosynthesis, and measurements of 76Se(α , γ) 80Kr. The latter measurements determine the rate of the reverse reaction, 80Kr(γ , α) 76Se, an important waiting point in the synthesis of the p-nuclei. I will also discuss future (and ongoing) developments at DRAGON, including the commissioning of a new chamber for high-precision elastic scattering measurements and plans to determine the 330 keV resonance strength in 18F(p , γ) 19Ne via measurements of 15O(α , γ) 19Ne and 15O + α elastic scattering.

  2. Measuring Radiation Damage from Heavy Energetic Ions in Aluminum

    SciTech Connect

    Kostin, M., PI-MSU; Ronningen, R., PI-MSU; Ahle, L., PI-LLNL; Gabriel, T., Scientific Investigation and Development; Mansur, L., PI-ORNL; Leonard, K., ORNL; Mokhov, N., FNAL; Niita, K., RIST, Japan

    2009-02-21

    An intense beam of 122 MeV/u (9.3 GeV) 76Ge ions was stopped in aluminum samples at the Coupled Cyclotron Facility at NSCL, MSU. Attempts were made at ORNL to measure changes in material properties by measuring changes in electrical resistivity and microhardness, and by transmission electron microscopy characterization, for defect density caused by radiation damage, as a function of depth and integrated ion flux. These measurements are relevant for estimating damage to components at a rare isotope beam facility.

  3. RADIATIVE PROPERTY MEASUREMENTS OF OXY-FUEL FLAMES

    SciTech Connect

    Clinton R. Bedick; Stephen K. Beer; Kent H. Casleton; Benjamin T. Chorpening; David W. Shaw; M. Joseph Yip

    2011-03-01

    As part of the DOE Existing Plants, Emissions and Capture (EPEC) program, oxy-combustion is being investigated as a method to simplify carbon capture and reduce the parasitic energy penalties associated with separating CO2 from a dilute flue gas. Gas-phase radiation heat transfer in boilers becomes significant when shifting from air-firing to oxycombustion, and must be accurately represented in models. Currently, radiative property data are not widely available in the literature for conditions appropriate to this environment. In order to facilitate the development and validation of accurate oxy-combustion models, NETL conducted a series of studies to measure radiation properties of oxy-fuel flames at adiabatic flame temperatures of 1750 - 1950K, and product molar concentrations ranging from 95% CO2 to 100% steam, determined by equilibrium calculations. Transmission coefficients were measured as a function of wavelength using a mid-IR imaging spectrometer and a blackbody radiation source. Additionally, flame temperatures were calculated using data collected within CO2 and H2O absorption bands. Experimental results were compared to two statistical narrowband models and experimental data from literature sources. These comparisons showed good overall agreement, although differences between the models and experimental results were noted, particularly for the R branch of the 2.7 μm H2O band.

  4. Calibration of TEPC for CubeSat Experiment to Measure Space Radiation

    NASA Astrophysics Data System (ADS)

    Nam, Uk-Won; Park, Won-Kee; Lee, Jaejin; Pyo, Jeonghyun; Moon, Bong-Kon; Lee, Dae-Hee; Jin, Ho; Lee, Seongwhan; Kim, Jungho; Kitamura, Hisashi; Uchihori, Yukio; Kim, Sunghwan

    2015-06-01

    A newly designed Tissue Equivalent Proportional Counter (TEPC) has been developed for the CubeSat mission, SIGMA (Scientific cubesat with Instruments for Global Magnetic field and rAdiation) to investigate space radiation. In order to test the performance of the TEPC, we have performed heavy ion beam experiments with the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. In space, human cells can be exposed to complex radiation sources, such as X-ray, Gamma ray, energetic electrons, protons, neutrons and heavy charged particles in a huge range of energies. These generate much a larger range of Linear Energy Transfer (LET) than on the ground and cause unexpected effects on human cells. In order to measure a large range of LET, from 0.3 to 1,000 keV/?m, we developed a compact TEPC which measures ionized particles produced by collisions between radiation sources and tissue equivalent materials in the detector. By measuring LET spectra, we can easily derive the equivalent dose from the complicated space radiation field. In this HIMAC experiment, we successfully obtained the linearity response for the TEPC with Fe 500 MeV/u and C 290 MeV/u beams and demonstrated the performance of the active radiation detector.

  5. Airborne gamma radiation soil moisture measurements over short flight lines

    NASA Technical Reports Server (NTRS)

    Peck, Eugene L.; Carrol, Thomas R.; Lipinski, Daniel M.

    1990-01-01

    Results are presented on airborne gamma radiation measurements of soil moisture condition, carried out along short flight lines as part of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE). Data were collected over an area in Kansas during the summers of 1987 and 1989. The airborne surveys, together with ground measurements, provide the most comprehensive set of airborne and ground truth data available in the U.S. for calibrating and evaluating airborne gamma flight lines. Analysis showed that, using standard National Weather Service weights for the K, Tl, and Gc radiation windows, the airborne soil moisture estimates for the FIFE lines had a root mean square error of no greater than 3.0 percent soil moisture. The soil moisture estimates for sections having acquisition time of at least 15 sec were found to be reliable.

  6. The measurement of radiation exposure of astronauts by radiochemical techniques

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.

    1972-01-01

    The principal gamma-ray emitting radioisotopes, produced in the body of astronauts by cosmic-ray bombardment, which have half-lives long enough to be useful for radiation dose evaluation, are Be-7, Na-22, and Na-24. The sodium isotopes were measured in the preflight and postflight urine and feces, and those feces specimens collected during the manned Apollo missions, by analysis of the urine salts and the raw feces in large crystal multidimensional gamma-ray spectrometers. The Be-7 was chemically separated, and its concentration measured in an all NaI (TL), anticoincidence shielded, scintillation well crystal. The astronaut radiation dose in millirads, as determined for the Apollo 7, 8, 9, 10, 11, 12, and 13 missions, was 330, 160, smaller than 315, 870 plus or minus 550, 31, 110, and smaller than 250, respectively.

  7. A Novel Microsensor for Measuring Angular Distribution of Radiative Intensity.

    PubMed

    Murphy, Thomas E; Pilorz, Stuart; Prufert-Bebout, Leslie; Bebout, Brad

    2015-01-01

    This article presents the design, construction and characterization of a novel type of light probe for measuring the angular radiance distribution of light fields. The differential acceptance angle (DAA) probe can resolve the directionality of a light field in environments with steep light gradients, such as microbial mats, without the need to remove, reorient, and reinsert the probe, a clear advantage over prior techniques. The probe consists of an inner irradiance sensor inside a concentric, moveable light-absorbing sheath. The radiative intensity in a specific zenith direction can be calculated by comparing the irradiance onto the sensor at different acceptance angles. We used this probe to measure the angular radiance distribution of two sample light fields, and observed good agreement with a conventional radiance probe. The DAA probe will aid researchers in understanding light transfer physics in dense microbial communities and expedite validation of numerical radiative transfer models for these environments. PMID:25763775

  8. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    SciTech Connect

    Sannibale, F.; Stupakov, G.V.; Zolotorev, M.S.; Filippetto, D.; Jagerhofer, L.; /Vienna, Tech. U.

    2009-12-09

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  9. Absolute bunch length measurements by incoherent radiation fluctuation analysis

    SciTech Connect

    Sannibale, Fernando; Stupakov, Gennady; Zolotorev, Max; Filippetto, Daniele; Jagerhofer, Lukas

    2008-09-29

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  10. Some cosmic radiation dose measurements aboard flights connecting Zagreb Airport.

    PubMed

    Vuković, B; Radolić, V; Lisjak, I; Vekić, B; Poje, M; Planinić, J

    2008-02-01

    When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A320 and ATR40 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or 10B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb-Paris-Buenos Aires and reversely, when one measured non-neutron cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 microSv/h and the TLD dosimeter registered the dose equivalent of 75 microSv or the average dose rate of 2.7 microSv/h; the neutron dosimeter gave the dose rate of 2.4 microSv/h. In the same month, February 2005, a traveling to Japan (24-h-flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4microSv/h; the neutron dosimeter gave the dose rate of 2.5 microSv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude that the neutron component carried about 50% of the total dose, that was near other known data.

  11. Some cosmic radiation dose measurements aboard flights connecting Zagreb Airport.

    PubMed

    Vuković, B; Radolić, V; Lisjak, I; Vekić, B; Poje, M; Planinić, J

    2008-02-01

    When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A320 and ATR40 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or 10B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb-Paris-Buenos Aires and reversely, when one measured non-neutron cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 microSv/h and the TLD dosimeter registered the dose equivalent of 75 microSv or the average dose rate of 2.7 microSv/h; the neutron dosimeter gave the dose rate of 2.4 microSv/h. In the same month, February 2005, a traveling to Japan (24-h-flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4microSv/h; the neutron dosimeter gave the dose rate of 2.5 microSv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude that the neutron component carried about 50% of the total dose, that was near other known data. PMID:17935999

  12. Plasma ion temperature measurements via charge exchange recombination radiation

    NASA Astrophysics Data System (ADS)

    Fonck, R. J.; Goldston, R. J.; Kaita, R.; Post, D. E.

    1983-02-01

    Spatially and temporally resolved plasma ion temperatures can be determined by measuring the Doppler-broadened line profiles of transitions excited by charge-exchange recombination reactions between fast hydrogen atoms and fully ionized low-Z ions. Plasma rotation velocity profiles can also be obtained. A sample result from the PDX tokamak using He+ radiation is presented, and expected line intensities for model cases for PDX and TFTR are calculated.

  13. Plasma ion temperature measurements via charge-exchange recombination radiation

    SciTech Connect

    Fonck, R.J.; Goldston, R.J.; Kaita, R.; Post, D.E.

    1982-11-01

    Spatially and temporally resolved plasma ion temperatures can be determined by measuring the Doppler-broadened line profiles of transitions excited by charge-exchange recombination reactions between fast hydrogen atoms and fully ionized low-Z ions. Plasma rotation velocity profiles can also be obtained. A sample result from the PDX tokamak using He/sup +/ radiation is presented, and expected line intensities for model cases for PDX and TFTR are calculated.

  14. Plasma ion temperature measurements via charge exchange recombination radiation

    SciTech Connect

    Fonck, R.J.; Goldston, R.J.; Kaita, R.; Post, D.E.

    1983-02-01

    Spatially and temporally resolved plasma ion temperatures can be determined by measuring the Doppler-broadened line profiles of transitions excited by charge-exchange recombination reactions between fast hydrogen atoms and fully ionized low-Z ions. Plasma rotation velocity profiles can also be obtained. A sample result from the PDX tokamak using He/sup +/ radiation is presented, and expected line intensities for model cases for PDX and TFTR are calculated.

  15. Photosynthetically active radiation and its relationship with global solar radiation in Central China.

    PubMed

    Wang, Lunche; Gong, Wei; Ma, Yingying; Hu, Bo; Zhang, Miao

    2014-08-01

    Photosynthetically active radiation (PAR) and other solar components were observed for a period of 3 years at Wuhan, China to determine for the first time the temporal variability of PAR fraction [PAR/G (G here stands for global solar radiation)] and its dependence on different sky conditions in Central China. PAR, G and PAR/G showed similar seasonal features that peaked in summer and reached their lowest values in winter. The seasonal PAR/G ranged from 1.70 E MJ(-1) (winter) to 2.01 E MJ(-1) (summer) with an annual mean value of 1.89 E MJ(-1). Hourly values of PAR/G increased from 1.78 to 2.11 E MJ(-1) on average as sky conditions changed from clear to cloudy. Monthly mean hourly PAR/G revealed a diurnal variation, with highest values observed around sunrise and sunset, slightly higher PAR fractions were also found around noon for most months. The effect of daylength on PAR/G was also studied and no significant impact was found. Three models were developed to estimate PAR from G. These models consisted of atmospheric parameters that were found to cause substantial changes of PAR/G, such as sky clearness, brightness, path length and the sky clearness index. The estimations obtained from different models were very close to the measured values with maximum relative errors below 8 % (hourly values) in Wuhan. The models were not only tested at seven radiation stations in Central China, but also verified in six stations with different climates in China. The models were found to estimate PAR accurately from commonly available G data in Central China; however, the results also implied that the models need to be modified to account for local climatic conditions when applied to the whole country.

  16. Spectral estimators of absorbed photosynthetically active radiation in corn canopies

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Daughtry, C. S. T.; Bauer, M. E.

    1984-01-01

    Most models of crop growth and yield require an estimate of canopy leaf area index (LAI) or absorption of radiation. Relationships between photosynthetically active radiation (PAR) absorbed by corn canopies and the spectral reflectance of the canopies were investigated. Reflectance factor data were acquired with a LANDSAT MSS band radiometer. From planting to silking, the three spectrally predicted vegetation indices examined were associated with more than 95% of the variability in absorbed PAR. The relationships developed between absorbed PAR and the three indices were evaluated with reflectance factor data acquired from corn canopies planted in 1979 through 1982. Seasonal cumulations of measured LAI and each of the three indices were associated with greater than 50% of the variation in final grain yields from the test years. Seasonal cumulations of daily absorbed PAR were associated with up to 73% of the variation in final grain yields. Absorbed PAR, cumulated through the growing season, is a better indicator of yield than cumulated leaf area index. Absorbed PAR may be estimated reliably from spectral reflectance data of crop canopies.

  17. Spectral estimators of absorbed photosynthetically active radiation in corn canopies

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Daughtry, C. S. T.; Bauer, M. E.

    1985-01-01

    Most models of crop growth and yield require an estimate of canopy leaf area index (LAI) or absorption of radiation. Relationships between photosynthetically active radiation (PAR) absorbed by corn canopies and the spectral reflectance of the canopies were investigated. Reflectance factor data were acquired with a Landsat MSS band radiometer. From planting to silking, the three spectrally predicted vegetation indices examined were associated with more than 95 percent of the variability in absorbed PAR. The relationships developed between absorbed PAR and the three indices were evaluated with reflectance factor data acquired from corn canopies planted in 1979 through 1982. Seasonal cumulations of measured LAI and each of the three indices were associated with greater than 50 percent of the variation in final grain yields from the test years. Seasonal cumulations of daily absorbed PAR were associated with up to 73 percent of the variation in final grain yields. Absorbed PAR, cumulated through the growing season, is a better indicator of yield than cumulated leaf area index. Absorbed PAR may be estimated reliably from spectral reflectance data of crop canopies.

  18. Millimeter wave radiative transfer studies for precipitation measurements

    NASA Technical Reports Server (NTRS)

    Vivekanandan, J.; Evans, Frank

    1989-01-01

    Scattering calculations using the discrete dipole approximation and vector radiative transfer calculations were performed to model multiparameter radar return and passive microwave emission for a simple model of a winter storm. The issue of dendrite riming was addressed by computing scattering properties of thin ice disks with varying bulk density. It was shown that C-band multiparameter radar contains information about particle density and the number concentration of the ice particles. The radiative transfer modeling indicated that polarized multifrequency passive microwave emission may be used to infer some properties of ice hydrometers. Detailed radar modeling and vector radiative transfer modeling is in progress to enhance the understanding of simultaneous radar and radiometer measurements, as in the case of the proposed TRMM field program. A one-dimensional cloud model will be used to simulate the storm structure in detail and study the microphysics, such as size and density. Multifrequency polarized radiometer measurements from the SSMI satellite instrument will be analyzed in relation to dual-frequency and dual-polarization radar measurements.

  19. European measurements of aircraft crew exposure to cosmic radiation.

    PubMed

    Menzel, H G; O'Sullivan, D; Beck, P; Bartlett, D

    2000-11-01

    For more than 5 y, the European Commission has supported research into scientific and technical aspects of cosmic-ray dosimetry at flight altitudes in civil radiation. This has been in response to legislation to regard exposure of aircraft crew as occupational, following the recommendations of the International Commission on Radiological Protection in Publication 60. The response to increased public interest and concern, and in anticipation of European and national current work, within a total of three multi-national, multi-partner research contracts, is based on a comprehensive approach including measurements with dosimetric and spectrometric instruments during flights, at high-mountain altitudes, and in a high-energy radiation reference field at CERN, as well as cosmic-ray transport calculations. The work involves scientists in the fields of neutron physics, cosmic-ray physics, and general dosimetry. A detailed set of measurements has been obtained by employing a wide range of detectors on several routes, both on subsonic and supersonic aircraft. Many of the measurements were made simultaneously by several instruments allowing the intercomparison of results. This paper presents a brief overview of results obtained. It demonstrates that the knowledge about radiation fields and on exposure data has been substantially consolidated and that the available data provide an adequate basis for dose assessments of aircraft crew, which will be legally required in the European Union after 13 May 2000.

  20. Comparative Measurements of Cosmic Radiation Monitors for Aircrew Exposure Assessment

    NASA Astrophysics Data System (ADS)

    Getley, I. L.; Bennett, L. G. I.; Boudreau, M. L.; Lewis, B. J.; Green, A. R.; Butler, A.; Takada, M.; Nakamura, T.

    Various commercially available electronic personal dosimeters (EPDs) have recently been flown on numerous scheduled airline flights in order to determine their viability as small, convenient monitors to measure cosmic radiation at altitude. Often, frequent flyers or airline crew will acquire such dosimeters and report the readings from their flights, without due regard for the mixed radiation field at altitude, which is different from the intended fields on land. A sampling of EPDs has been compared to two types of spectrometers, which measure the total radiation spectrum. The "HAWK" tissue equivalent proportional counter is considered a reference instrument and measures the total dose equivalent H*(10). The Liulin-4N and 4SN linear energy transfer spectrometers each have a silicon semiconductor-based PIN diode detector which provides an absorbed dose, D, but have been further developed to provide H*(10). A Thermo Electron FH41B and B-10, and EPD-N2, and several personal dosimeters (Fuji NRY-21 and NRF-20, and RADOS DIS-100) were also flown.

  1. Theory and measurement of emittance properties for radiation thermometry applications.

    NASA Technical Reports Server (NTRS)

    Dewitt, D. P.; Hernicz, R. S.

    1972-01-01

    Some basic concepts of radiation physics are briefly reviewed to provide an introduction to the radiative properties - including emittance, reflectance, absorptance, and transmittance - their definitions, interrelations, theory and methods of measurement. Analyzed data showing typical characteristics of temperature and wavelength dependence, surface effects and environmental influences on the radiation properties of selected classes of materials are presented. Emphasis is placed on those emittance properties of particular interest to conventional radiation thermometry applications, but sufficient generality on all properties is presented to be useful for new or unusual techniques where a more detailed understanding of the behavior of materials is desirable. Data sources are identified to assist the reader in locating property information. It is the intention of the paper to give the reader a background to become more fully aware of the pitfalls, limitations, but of course, advantages in the use of data from the literature. The paper is written in the form of an abbreviated review fully documenting the more important topics and concepts which can only be treated briefly.

  2. UV index forecasts and measurements of health-effective radiation.

    PubMed

    Feister, Uwe; Laschewski, Gudrun; Grewe, Rolf-Dieter

    2011-01-10

    While erythemal irradiance as a potentially damaging effect to the skin has been extensively studied and short-term forecasts have been issued to the public to reduce detrimental immediate and long-term effects such as sunburn and skin cancer by overexposure, beneficial effects to human health such as vitamin D(3) production by UV radiation and melatonin suppression by blue visible light have attained more and more attention, though both of them have not become part of forecasting yet. Using 4years of solar radiation data measured at the mid-latitude site Lindenberg (52°N), and forecast daily maximum UV index values, an overall good correspondence has been found. The data base of solar UV radiation and illuminance has also been used to analyze effects of clouds and aerosols on the effective irradiance. Optically thick clouds can strongly modify the ratios between erythemal and vitamin D(3) effective irradiance such that direct radiative transfer modeling of the latter in future UV forecasts should be preferably used. If parameterizations of vitamin D(3) effective irradiance from erythemal irradiance are used instead, the optical cloud depth would have to be taken into account to avoid an overestimation of vitamin D(3) with parameterizations neglecting cloud optical depth. Particular emphasis for the beneficial effects has been laid in our study on low exposure. Daily doses of solar irradiation for both vitamin D(3) and melatonin suppression do not reach minimum threshold doses even with clear sky and unobstructed horizon during the winter months.

  3. Science Plan for the Atmospheric Radiation Measurement Program (ARM)

    SciTech Connect

    1996-02-01

    The purpose of this Atmospheric Radiation Measurement (ARM) Science Plan is to articulate the scientific issues driving the ARM Program, and to relate them to DOE`s programmatic objectives for ARM, based on the experience and scientific progress gained over the past five years. ARM programmatic objectives are to: (1) Relate observed radiative fluxes and radiances in the atmosphere, spectrally resolved and as a function of position and time, to the temperature and composition of the atmosphere, specifically including water vapor and clouds, and to surface properties, and sample sufficient variety of situations so as to span a wide range of climatologically relevant possibilities; (2) develop and test parameterizations that can be used to accurately predict the radiative properties and to model the radiative interactions involving water vapor and clouds within the atmosphere, with the objective of incorporating these parameterizations into general circulation models. The primary observational methods remote sending and other observations at the surface, particularly remote sensing of clouds, water vapor and aerosols.

  4. Measuring solar UV radiation with EBT radiochromic film.

    PubMed

    Butson, Ethan T; Cheung, Tsang; Yu, Peter K N; Butson, Martin J

    2010-10-21

    Ultraviolet radiation dosimetry has been performed with the use of a radiochromic film dosimeter called Gafchromic EBT for solar radiation exposure. The film changes from a clear colour to blue colour when exposed to ultraviolet radiation and results have shown that the colour change is reproducible within ±10% at 5 kJ m(-2) UV exposure under various conditions of solar radiation. Parameters tested included changes in season (summer versus winter exposure), time of day, as well as sky conditions such as cloudy skies versus clear skies. As the radiochromic films' permanent colour change occurs in the visible wavelengths the film can be analysed with a desktop scanner with the most sensitive channel for analysis being the red component of the signal. Results showed that an exposure of 5 kJ m(-2) (approximately 1 h exposure in full sun during summer) produced an approximate 0.28 change in the net OD when analysed in reflection mode on the desktop scanner which is significant darkening. The main advantages of this film type, and thus the new EBT2 film which has replaced EBT for measurement of UV exposure, is the visible colour change and thus easy analysis using a desktop scanner, its uniformity in response and its robust physical strength for use in outside exposure situations. PMID:20858922

  5. Measurement of gamma and neutron radiations inside spent fuel assemblies with passive detectors

    NASA Astrophysics Data System (ADS)

    Viererbl, L.; Lahodová, Z.; Voljanskij, A.; Klupák, V.; Koleška, M.; Cabalka, M.; Turek, K.

    2011-10-01

    During operation of a fission nuclear reactor, many radionuclides are generated in fuel by fission and activation of 235U, 238U and other nuclides present in the assembly. After removal of a fuel assembly from the core, these radionuclides are sources of different types of radiation. Gamma and neutron radiation emitted from an assembly can be non-destructively detected with different types of detectors. In this paper, a new method of measurement of radiation from a spent fuel assembly is presented. It is based on usage of passive detectors, such as alanine dosimeters for gamma radiation and track detectors for neutron radiation. Measurements are made on the IRT-2M spent fuel assemblies used in the LVR-15 research reactor. During irradiation of detectors, the fuel assembly is located in a water storage pool at a depth of 6 m. Detectors are inserted into central hole of the assembly, irradiated for a defined time interval, and after the detectors removed from the assembly, gamma dose or neutron fluence are evaluated. Measured profiles of gamma dose rate and neutron fluence rate inside of the spent fuel assembly are presented. This measurement can be used to evaluate relative fuel burn-up.

  6. Calculation and interpretation of In-Situ measurements of initial radiations at Hiroshima and Nagasaki

    SciTech Connect

    Loewe, W.E.

    1983-02-16

    Cobalt activation calculations will be reviewed, and similar comparisons of sulfur activation interior to electrical insulators on power transmission lines will be discussed. The relationship between neutron tissue kermas one to two kilometers from hypocenter and the particular activations of cobalt and sulfur are reviewed. At present, measured and calculated quantities agree within associated uncertainties, which are substantial. Additional work to shrink these uncertainties will be discussed. Particular cobalt activation topics will include: the sensitivity to thermal neutrons outside the pillar; calculated values using actual Nagasaki concrete composition; and calculational advances to improve modelling of the actual configuration. Particular sulfur activation topics will include: absolute comparisons of measured and calculated ratios of dpm/gm of /sup 32/P at all measured ranges, based on approximate experimental values for insulator attentuation and source radiations; the relationship between sulfur activation within a kilometer of hypocenter and kermas at two kilometers; and calculational advances to improve modelling of the actual configuration.

  7. Measurements of prompt radiation induced conductivity of Kapton.

    SciTech Connect

    Preston, Eric F.; Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Stringer, Thomas Arthur

    2010-10-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Kapton (polyimide) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil samples were irradiated with a 0.5 {mu}s pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E10 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 6E-17 and 2E-16 mhos/m per rad/s, depending on the dose rate and the pulse width.

  8. [Analyses of spectral emissivity in radiation temperature measurement].

    PubMed

    Fu, Tai-Ran; Cheng, Xiao-Fang; Zhong, Mao-Hua; Yang, Zang-Jian

    2008-01-01

    The complexity of the spectral emissivity of actual surfaces is the key point in the research and applications of radiation temperature measurement, resulting in the difficulty in the achievement of the temperature measurement. In the present paper, based on the discussions of the Taylor expansion, the non-dimension wavelength and the exponent, the authors describe the mathematical expression of the spectral emissivity of actual surfaces, and establish the general spectral emissivity function. Through the fitting of experimental data of the spectral emissivities of different metals at different temperatures, the applicability of the spectral emissivity function is verified which especially becomes the fundamental in the research of primary spectrum pyrometry.

  9. Measurements of prompt radiation induced conductivity in Teflon (PTFE).

    SciTech Connect

    Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, E.

    2013-05-01

    We performed measurements of the prompt radiation induced conductivity (RIC) in thin samples of Teflon (PTFE) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil (76.2 microns) samples were irradiated with a 0.5 %CE%BCs pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E11 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Details of the experimental apparatus and analysis are reported in this report on prompt RIC in Teflon.

  10. Atmospheric Radiation Measurement Program - unmanned aerospace vehicle: The follow-on phase

    SciTech Connect

    Vitko, J. Jr.

    1995-04-01

    Unmanned Aerospace Vehicle (UAV) demonstration flights (UDF) are designed to provide an early demonstration of the scientific utility of UAVs by using an existing UAV and instruments to measure broadband radiative flux profiles under clear sky conditions. UDF is but the first of three phases of ARM-UAV. The second phase significantly extends both the UAV measurement techniques and the available instrumentation to allow both multi-UAV measurements in cloudy skies and extended duration measurements in the tropopause. These activities build naturally to the third and final phase, that of full operational capability, i.e., UAVs capable of autonomous operations at 20-km altitudes for multiple days with a full suite of instrumentation for measuring radiative flux, cloud properties, and water vapor profiles.

  11. Active Dust Mitigation Technology for Thermal Radiators for Lunar Exploration

    NASA Technical Reports Server (NTRS)

    Calle, C. I.; Buhler, C. R.; Hogue, M. D.; Johansen, M. R.; Hopkins, J. W.; Holloway, N. M. H.; Connell, J. W.; Chen, A.; Irwin, S. A.; Case, S. O.; VanSuetendael, N. J.; Snyder, S. J.; Clements, J. S.

    2010-01-01

    Dust accumulation on thermal radiator surfaces planned for lunar exploration will significantly reduce their efficiency. Evidence from the Apollo missions shows that an insulating layer of dust accumulated on radiator surfaces could not be removed and caused serious thermal control problems. Temperatures measured at different locations in the magnetometer on Apollo 12 were 38 C warmer than expected due to lunar dust accumulation. In this paper, we report on the application of the Electrodynamic Dust Shield (EDS) technology being developed in our NASA laboratory and applied to thermal radiator surfaces. The EDS uses electrostatic and dielectrophoretic forces generated by a grid of electrodes running a 2 micro A electric current to remove dust particles from surfaces. Working prototypes of EDS systems on solar panels and on thermal radiators have been successfully developed and tested at vacuum with clearing efficiencies above 92%. For this work EDS prototypes on flexible and rigid thermal radiators were developed and tested at vacuum.

  12. Fluorine gettering by activated charcoal in a radiation environment

    SciTech Connect

    Felker, L.K.; Toth, L.M.

    1988-10-01

    Activated charcoal has been shown to be an effective gettering agent for the fluorine gas that is liberated in a radiation environment. Even though activated charcoal is a commonly used getter, little is known about the radiation stability of the fluorine-charcoal product. This work has shown that not only is the product stable in high gamma radiation fields, but also that radiation enhances the capacity of the charcoal for the fluorine. The most useful application of this work is with the Molten Salt Reactor Experiment (MSRE) fuel salt because the radioactive components (fission products and actinides) cause radiolytic damage to the solid LiF-BeF/sub 2/-ZrF/sub 4/-UF/sub 4/ (64.5, 30.3, 5.0, 0.13 mol %, respectively) resulting in the liberation of fluorine gas. This work has also demonstrated that the maximum damage to the fuel salt by approx.3 /times/ 10/sup 7/ R/h gamma radiation is approximately 2%, at which point the rate of recombination of fluorine with active metal sites within the salt lattice equals the rate of fluorine generation. The enhanced reactivity of the activated charcoal and radiation stability of the product ensures that the gettered fluorine will stay sequestered in the charcoal.

  13. Solar Radiation Measurements Onboard the Research Aircraft HALO

    NASA Astrophysics Data System (ADS)

    Lohse, I.; Bohn, B.; Werner, F.; Ehrlich, A.; Wendisch, M.

    2014-12-01

    Airborne measurements of the separated upward and downward components of solar spectral actinic flux densities for the determination of photolysis frequencies and of upward nadir spectral radiance were performed with the HALO Solar Radiation (HALO-SR) instrument package onboard the High Altitude and Long Range Research Aircraft (HALO). The instrumentation of HALO-SR is characterized and first measurement data from the Next-generation Aircraft Remote-Sensing for Validation Studies (NARVAL) campaigns in 2013 and 2014 are presented. The measured data are analyzed in the context of the retrieved microphysical and optical properties of clouds which were observed underneath the aircraft. Detailed angular sensitivities of the two optical actinic flux receivers were determined in the laboratory. The effects of deviations from the ideal response are investigated using radiative transfer calculations of atmospheric radiance distributions under various atmospheric conditions and different ground albedos. Corresponding correction factors are derived. Example photolysis frequencies are presented, which were sampled in the free troposphere and lower stratosphere over the Atlantic Ocean during the 2013/14 HALO NARVAL campaigns. Dependencies of photolysis frequencies on cloud cover, flight altitude and wavelength range of the photolysis process are investigated. Calculated actinic flux densities in the presence of clouds benefit from the measured spectral radiances. Retrieved cloud optical thicknesses and effective droplet radii are used as model input for the radiative transfer calculations. By comparison with the concurrent measurements of actinic flux densities the retrieval approach is validated. Acknowledgements: Funding by the Deutsche Forschungsgemeinschaft within the priority program HALO (BO 1580/4-1, WE 1900/21-1) is gratefully acknowledged.

  14. Radiation measurement platform for balloon flights based on the TriTel silicon detector telescope

    NASA Astrophysics Data System (ADS)

    Zabori, Balazs; Hirn, Attila; Pazmandi, Tamas; Apathy, Istvan; Szanto, Peter; Deme, Sandor

    Several measurements have been performed on the cosmic radiation field from the surface of the Earth up to the maximum altitudes of research airplanes. However the cosmic radiation field is not well known between 15 km and 30 km. Our experiment idea based on to study the radiation environment in the stratosphere. The main technical goals of our experiment were to test at first time the TriTel 3D silicon detector telescope system for future ISS missons and to develop a balloon technology platform for advanced cosmic radiation and dosimetric measurements. The main scientific goals were to give an assessment of the cosmic radiation field at the altitude of the BEXUS balloons, to use the TriTel system to determine dosimetric and radiation quantities during the ballon flight and to intercompare the TriTel and Pille results to provide a correction factor definition method for the Pille ISS measurements. To fulfil the scientific and technological objectives several different dosimeter systems were included in the experiment: an advanced version of the TriTel silicon detector telescope, Geiger-Müller counters, Pille passive thermoluminescent dosimeters and Solid State Nuclear Track Detectors. The experiment was built by students from Hungarian universities and flew on board the BEXUS stratospheric balloon in Northern Sweden (from ESRANGE Space Center). The float altitude was approximately 28.6 km and the total flight time was about 4 hours. The active instruments measured in real time and the ground team received the collected data continuously during the mission. The main technical goals were received since the operation of the TriTel experienced no failures and the experiment worked as it expected. This paper presents the scientific goals and results. From the TriTel measurements the deposited energy spectra, the Linear Energy Transfer spectra, the average quality factor of the cosmic radiation as well as the absorbed dose and the dose equivalent were determined for the

  15. Radiation Dose Measurement for High-Intensity Laser Interactions with Solid Targets at SLAC

    SciTech Connect

    Liang, Taiee

    2015-09-25

    A systematic study of photon and neutron radiation doses generated in high-intensity laser-solid interactions is underway at SLAC National Accelerator Laboratory. We found that these laser-solid experiments are being performed using a 25 TW (up to 1 J in 40 fs) femtosecond pulsed Ti:sapphire laser at the Linac Coherent Light Source’s (LCLS) Matter in Extreme Conditions (MEC) facility. Additionally, radiation measurements were performed with passive and active detectors deployed at various locations inside and outside the target chamber. Results from radiation dose measurements for laser-solid experiments at SLAC MEC in 2014 with peak intensity between 1018 to 7.1x1019 W/cm2 are presented.

  16. Solar Radiation and Cloud Radiative Forcing in the Pacific Warm Pool Estimated Using TOGA COARE Measurements

    NASA Technical Reports Server (NTRS)

    Chou, Ming-Dah; Chou, Shu-Hsien; Zhao, Wenzhong

    1999-01-01

    The energy budget of the tropical western Pacific (TWP) is particularly important because this is one of the most energetic convection regions on the Earth. Nearly half of the solar radiation incident at the top of atmosphere is absorbed at the surface and only about 22% absorbed in the atmosphere. A large portion of the excess heat absorbed at the surface is transferred to the atmosphere through evaporation, which provides energy and water for convection and precipitation. The western equatorial Pacific is characterized by the highest sea surface temperature (SST) and heaviest rainfall in the world ocean. A small variation of SST associated with the eastward shift of the warm pool during El-Nino/Souther Oscillation changes the atmospheric circulation pattern and affects the global climate. In a study of the TWP surface heat and momentum fluxes during the Tropical Ocean and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) Intensive observing period (IOP) from November 1992 to February have found that the solar radiation is the most important component of the surface energy budget, which undergoes significant temporal and spatial variation. The variations are influenced by the two 40-50 days Madden Julian Oscillations (MJOs) which propagated eastward from the Indian Ocean to the Central Pacific during the IOP. The TWP surface solar radiation during the COARE IOP was investigated by a number of studies. In addition, the effects of clouds on the solar heating of the atmosphere in the TWP was studied using energy budget analysis. In this study, we present some results of the TWP surface solar shortwave or SW radiation budget and the effect of clouds on the atmospheric solar heating using the surface radiation measurements and Japan's Geostationary Meteorological Satellite 4 radiance measurements during COARE IOP.

  17. Radiation therapy generates platelet-activating factor agonists

    PubMed Central

    Sahu, Ravi P.; Harrison, Kathleen A.; Weyerbacher, Jonathan; Murphy, Robert C.; Konger, Raymond L.; Garrett, Joy Elizabeth; Chin-Sinex, Helen Jan; Johnston, Michael Edward; Dynlacht, Joseph R.; Mendonca, Marc; McMullen, Kevin; Li, Gengxin; Spandau, Dan F.; Travers, Jeffrey B.

    2016-01-01

    Pro-oxidative stressors can suppress host immunity due to their ability to generate oxidized lipid agonists of the platelet-activating factor-receptor (PAF-R). As radiation therapy also induces reactive oxygen species, the present studies were designed to define whether ionizing radiation could generate PAF-R agonists and if these lipids could subvert host immunity. We demonstrate that radiation exposure of multiple tumor cell lines in-vitro, tumors in-vivo, and human subjects undergoing radiation therapy for skin tumors all generate PAF-R agonists. Structural characterization of radiation-induced PAF-R agonistic activity revealed PAF and multiple oxidized glycerophosphocholines that are produced non-enzymatically. In a murine melanoma tumor model, irradiation of one tumor augmented the growth of the other (non-treated) tumor in a PAF-R-dependent process blocked by a cyclooxygenase-2 inhibitor. These results indicate a novel pathway by which PAF-R agonists produced as a byproduct of radiation therapy could result in tumor treatment failure, and offer important insights into potential therapeutic strategies that could improve the overall antitumor effectiveness of radiation therapy regimens. PMID:26959112

  18. Radiation therapy generates platelet-activating factor agonists.

    PubMed

    Sahu, Ravi P; Harrison, Kathleen A; Weyerbacher, Jonathan; Murphy, Robert C; Konger, Raymond L; Garrett, Joy Elizabeth; Chin-Sinex, Helen Jan; Johnston, Michael Edward; Dynlacht, Joseph R; Mendonca, Marc; McMullen, Kevin; Li, Gengxin; Spandau, Dan F; Travers, Jeffrey B

    2016-04-12

    Pro-oxidative stressors can suppress host immunity due to their ability to generate oxidized lipid agonists of the platelet-activating factor-receptor (PAF-R). As radiation therapy also induces reactive oxygen species, the present studies were designed to define whether ionizing radiation could generate PAF-R agonists and if these lipids could subvert host immunity. We demonstrate that radiation exposure of multiple tumor cell lines in-vitro, tumors in-vivo, and human subjects undergoing radiation therapy for skin tumors all generate PAF-R agonists. Structural characterization of radiation-induced PAF-R agonistic activity revealed PAF and multiple oxidized glycerophosphocholines that are produced non-enzymatically. In a murine melanoma tumor model, irradiation of one tumor augmented the growth of the other (non-treated) tumor in a PAF-R-dependent process blocked by a cyclooxygenase-2 inhibitor. These results indicate a novel pathway by which PAF-R agonists produced as a byproduct of radiation therapy could result in tumor treatment failure, and offer important insights into potential therapeutic strategies that could improve the overall antitumor effectiveness of radiation therapy regimens. PMID:26959112

  19. Investigation of scene identification algorithms for radiation budget measurements

    NASA Technical Reports Server (NTRS)

    Diekmann, F. J.

    1986-01-01

    The computation of Earth radiation budget from satellite measurements requires the identification of the scene in order to select spectral factors and bidirectional models. A scene identification procedure is developed for AVHRR SW and LW data by using two radiative transfer models. These AVHRR GAC pixels are then attached to corresponding ERBE pixels and the results are sorted into scene identification probability matrices. These scene intercomparisons show that there generally is a higher tendency for underestimation of cloudiness over ocean at high cloud amounts, e.g., mostly cloudy instead of overcast, partly cloudy instead of mostly cloudy, for the ERBE relative to the AVHRR results. Reasons for this are explained. Preliminary estimates of the errors of exitances due to scene misidentification demonstrates the high dependency on the probability matrices. While the longwave error can generally be neglected the shortwave deviations have reached maximum values of more than 12% of the respective exitances.

  20. Radiation measuring apparatus employing variable rate pulse sampling control

    SciTech Connect

    Kakegawa, M.; Kumano, N.; Nohara, N.; Tanaka, E.; Tomitani, T.

    1980-01-29

    A scintillation type radiation-measuring apparatus comprising a radiation-detecting scintillator is described. A scintillation given off from the scintillator is converted into current by a photomultiplier tube. A current amplifier generates a plurality of pulses each proportional to the intensity of said converted current. The pulses have the width clipped by a clipped pulse generating circuit. The clipped form of the pulses is delayed by a delay circuit and integrated by an integrator; the wave height value of the outputs from the integrator is sampled by a sampling circuit to provide a sampled output. Means are provided to supply instructions to start and reset the operation of the integrator and to commence the operation of the sampling circuit in accordance with the interval between successively detected current pulses.

  1. Disease Activity Measures in Paediatric Rheumatic Diseases

    PubMed Central

    Luca, Nadia J.; Feldman, Brian M.

    2013-01-01

    Disease activity refers to potentially reversible aspects of a disease. Measurement of disease activity in paediatric rheumatic diseases is a critical component of patient care and clinical research. Disease activity measures are developed systematically, often involving consensus methods. To be useful, a disease activity measure must be feasible, valid, and interpretable. There are several challenges in quantifying disease activity in paediatric rheumatology; namely, the conditions are multidimensional, the level of activity must be valuated in the context of treatment being received, there is no gold standard for disease activity, and it is often difficult to incorporate the patient's perspective of their disease activity. To date, core sets of response variables are defined for juvenile idiopathic arthritis, juvenile systemic lupus erythematosus, and juvenile dermatomyositis, as well as definitions for improvement in response to therapy. Several specific absolute disease activity measures also exist for each condition. Further work is required to determine the optimal disease activity measures in paediatric rheumatology. PMID:24089617

  2. Radiation protection in radiologic technology: Apathy versus active involvement

    SciTech Connect

    Franz, K.H.

    1982-11-01

    The lack of active participation in radiation protection is a serious problem in Radiologic Technology today. Underlying the problem is professional apathy. An overview of the historical changes, as well as various recent developments in radiology, accentuate the importance of necessary changes in technologists' attitudes and activities. 22 references.

  3. In-flight radiation measurements on STS-60.

    PubMed

    Badhwar, G D; Golightly, M J; Konradi, A; Atwell, W; Kern, J W; Cash, B; Benton, E V; Frank, A L; Sanner, D; Keegan, R P; Frigo, L A; Petrov, V M; Tchernykh, I V; Akatov YuA; Shurshakov, V A; Arkhangelsky, V V; Kushin, V V; Klyachin, N A; Vana, N; Schoner, W

    1996-01-01

    A joint investigation between the United States and Russia to study the radiation environment inside the Space Shuttle flight STS-60 was carried out as part of the Shuttle-Mir Science Program (Phase 1). This is the first direct comparison of a number of different dosimetric measurement techniques between the two countries. STS-60 was launched on 3 February 1994 in a nearly circular 57 degrees x 353 km orbit with five U.S. astronauts and one Russian cosmonaut for 8.3 days. A variety of instruments provided crew radiation exposure, absorbed doses at fixed locations, neutron fluence and dose equivalent, linear energy transfer (LET) spectra of trapped and galactic cosmic radiation, and energy spectra and angular distribution of trapped protons. In general, there is good agreement between the U.S. and Russian measurements. The AP8 Min trapped proton model predicts an average of 1.8 times the measured absorbed dose. The average quality factor determined from measured lineal energy, y, spectra using a tissue equivalent proportional counter (TEPC), is in good agreement with that derived from the high temperature peak in the 6LiF thermoluminescent detectors (TLDs). The radiation exposure in the mid-deck locker from neutrons below 1 MeV was 2.53 +/- 1.33 microSv/day. The absorbed dose rates measured using a tissue equivalent proportional counter, were 171.1 +/- 0.4 and 127.4 +/- 0.4 microGy/day for trapped particles and galactic cosmic rays, respectively. The combined dose rate of 298.5 +/- 0.82 microGy/day is about a factor of 1.4 higher than that measured using TLDs. The westward longitude drift of the South Atlantic Anomaly (SAA) is estimated to be 0.22 +/- 0.02 degrees/y. We evaluated the effects of spacecraft attitudes on TEPC dose rates due to the highly anisotropic low-earth orbit proton environment. Changes in spacecraft attitude resulted in dose-rate variations by factors of up to 2 at the location of the TEPC. PMID:11539199

  4. Atmospheric radiation measurement program facilities newsletter, August 2002.

    SciTech Connect

    Holdridge, D. J.

    2002-08-29

    ARM in Australia--The Atmospheric Radiation Measurement (ARM) Program of the U.S. Department of Energy (DOE) has launched its newest Atmospheric Radiation and Cloud Station (ARCS) in Darwin, Australia. This is the fifth research site established since ARM Program inception in 1989. The new Darwin site and two other ARCS sites--on Manus Island and the island of Nauru--are in the Tropical Western Pacific region. The North American sites in the U.S. Southern Great Plains and on the North Slope of Alaska represent two different climate regions. A goal of the ARM Program is to improve understanding of (1) the ways clouds and atmospheric moisture interact with solar radiation and (2) the effects of these interactions on both a local and global climate. Years of collected data are being used to improve computer climate models so that their predictions are more accurate. The new Darwin site is at the Darwin International Airport, adjacent to the Darwin Airport Meteorological Office. The site features state-of-the-art instrumentation used to measure solar radiation and surface radiation balance; cloud parameters; and standard meteorological variables such as temperature, wind speed and direction, atmospheric moisture, precipitation rates, and barometric pressure. A data management system (DMS) consisting of two computer workstations collects, stores, processes, and backs up data from each of the ARCS instruments. Data are transmitted via the Internet to the United States for further processing and archiving with data from the other ARM sites. All ARM data are freely available via the Internet to the public and the worldwide scientific community (http://www.arm.gov/). Operational since April 2002, the Darwin site was officially dedicated on July 30, 2002, by dignitaries from both the United States and Australia. The site is a collaborative effort between DOE and the Australian Bureau of Meteorology's Special Services Unit--the equivalent of the U.S. National Weather Service

  5. Radiation protection guidance for activities in low-Earth orbit.

    PubMed

    Townsend, L W; Fry, R J M

    2002-01-01

    Scientific Committee 75 (SC 75) of the National Council on Radiation Protection and Measurements (NCRP) was assembled for the purpose of providing guidance to NASA concerning radiation protection in low-Earth orbit. The report of SC 75 was published in December 2000 as NCRP Report No. 132. In this presentation an overview of the findings and recommendations of the committee report will be presented. PMID:12539765

  6. Environmental gamma radiation measurement in district Swat, Pakistan.

    PubMed

    Jabbar, T; Khan, K; Subhani, M S; Akhter, P; Jabbar, A

    2008-01-01

    External exposure to environmental gamma ray sources is an important component of exposure to the public. A survey was carried out to determine activity concentration levels and associated doses from (226)Ra, (232)Th, (40)K and (137)Cs by means of high-resolution gamma ray spectrometry in the Swat district, famous for tourism. The mean concentrations for (226)Ra, (232)Th and (40)K were found to be 50.4 +/- 0.7, 34.8 +/- 0.7 and 434.5 +/- 7.4 Bq kg(-1), respectively, in soil samples, which are slightly more than the world average values. However, (137)Cs was only found in the soil sample of Barikot with an activity concentration of 34 +/- 1.2 Bq kg(-1). Only (40)K was determined in vegetation samples with an average activity of 172.2 +/- 1.7 Bq kg(-1), whereas in water samples, all radionuclides were found below lower limits of detection. The radium equivalent activity in all soil samples is lower than the limit set in the Organisation for Economic Cooperation and Development report (370 Bq kg(-1)). The value of the external exposure dose has been determined from the content of these radionuclides in soil. The average terrestrial gamma air absorbed dose rate was observed to be 62.4 nGy h(-1), which yields an annual effective dose of 0.08 mSv. The average value of the annual effective dose lies close to the global range of outdoor radiation exposure given in United Nations Scientific Committee on the Effects of Atomic Radiation. However, the main component of the radiation dose to the population residing in the study area arises from cosmic ray due to high altitude. PMID:18936087

  7. Calibration facilities for borehole and surface environmental radiation measurements

    SciTech Connect

    Stromswold, D.C.

    1994-04-01

    Measuring radiation from contaminated soil and buildings is important in the cleanup of land areas and facilities. It provides the means for quantifying the amount of contamination and assessing the success of efforts to restore areas to acceptable conditions for public use. Instruments that measure in situ radiation from natural or radiochemically-contaminated earth formations must be calibrated in appropriate facilities to provide quantitative assessments of concentrations of radionuclides. For instruments that are inserted into boreholes, these calibration facilities are typically special models having holes for probe insertion and having sufficient size to appear radiometrically ``infinite`` in extent. The US Department of Energy (DOE) has such models at Hanford, Washington, and Grand Junction, Colorado. They are concrete cylinders having a central borehole and containing known, enhanced amounts of K, U, and Th for spectral gamma-ray measurements. Additional models contain U for calibrating neutron probes for fissile materials and total-count gamma-ray probes. Models for calibrating neutron probes for moisture measurements in unsaturated formations exist for steel-cased boreholes at Hanford and for uncased boreholes at the DOE`s Nevada Test Site. Large surface pads are available at Grand Junction for portable, vehicle-mounted, or airplane-mounted spectral gamma-ray detectors.

  8. Surface summertime radiative forcing by shallow cumuli at the Atmospheric Radiation Measurement Southern Great Plains site

    SciTech Connect

    Berg, Larry K.; Kassianov, Evgueni I.; Long, Charles N.; Mills Jr., David L.

    2011-01-08

    Although shallow cumuli are common over large areas of the globe, their impact on the surface radiative forcing has not been carefully evaluated. This study addresses this shortcoming by analyzing data from days with shallow cumuli collected over eight summers (2000-2007) at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility (collectively ACRF) Southern Great Plains site. During periods with clouds, the average shortwave and longwave radiative forcings are 45.5 W m-2 and +11.6 W m-2, respectively. The forcing has been defined so that a negative (positive) forcing indicates a surface cooling (warming). On average, the shortwave forcing is negative, however, instances with positive shortwave forcing are observed approximately 20% of the time. These positive values of shortwave forcing are associated with three-dimensional radiative effects of the clouds. The three-dimensional effects are shown to be largest for intermediate cloud amounts. The magnitude of the three-dimensional effects decreased with averaging time, but it is not negligibly small even for large averaging times as long as four hours.

  9. Soot and Radiation Measurements in Microgravity Jet Diffusion Flames

    NASA Technical Reports Server (NTRS)

    Ku, Jerry C.

    1996-01-01

    The subject of soot formation and radiation heat transfer in microgravity jet diffusion flames is important not only for the understanding of fundamental transport processes involved but also for providing findings relevant to spacecraft fire safety and soot emissions and radiant heat loads of combustors used in air-breathing propulsion systems. Our objectives are to measure and model soot volume fraction, temperature, and radiative heat fluxes in microgravity jet diffusion flames. For this four-year project, we have successfully completed three tasks, which have resulted in new research methodologies and original results. First is the implementation of a thermophoretic soot sampling technique for measuring particle size and aggregate morphology in drop-tower and other reduced gravity experiments. In those laminar flames studied, we found that microgravity soot aggregates typically consist of more primary particles and primary particles are larger in size than those under normal gravity. Comparisons based on data obtained from limited samples show that the soot aggregate's fractal dimension varies within +/- 20% of its typical value of 1.75, with no clear trends between normal and reduced gravity conditions. Second is the development and implementation of a new imaging absorption technique. By properly expanding and spatially-filtering the laser beam to image the flame absorption on a CCD camera and applying numerical smoothing procedures, this technique is capable of measuring instantaneous full-field soot volume fractions. Results from this technique have shown the significant differences in local soot volume fraction, smoking point, and flame shape between normal and reduced gravity flames. We observed that some laminar flames become open-tipped and smoking under microgravity. The third task we completed is the development of a computer program which integrates and couples flame structure, soot formation, and flame radiation analyses together. We found good

  10. Nuclear fragmentation measurements for hadrontherapy and space radiation protection

    SciTech Connect

    De Napoli, M.; Agodi, C.; Blancato, A. A.; Cavallaro, M.; Cirrone, G. A. P.; Cuttone, G.; Sardina, D.; Scuderi, V.; Battistoni, G.; Bondi, M.; Cappuzzello, F.; Carbone, D.; Nicolosi, D.; Raciti, G.; Tropea, S.; Giacoppo, F.; Morone, M. C.; Pandola, L.; Rapisarda, E.; Romano, F.; and others

    2013-04-19

    Nuclear fragmentation measurements are necessary in hadrontherapy and space radiation protection, to predict the effects of the ion nuclear interactions within the human body. Nowadays, a very limited set of carbon fragmentation cross sections has been measured and in particular, to our knowledge, no double differential fragmentation cross sections at intermediate energies are available in literature. We have measured the double differential cross sections and the angular distributions of the secondary fragments produced in the {sup 12}C fragmentation at 62 AMeV on a thin carbon target. The experimental data have been also used to benchmark the prediction capability of the Geant4 Monte Carlo code at intermediate energies, where it was never tested before.

  11. How to obtain traceability on optical radiation measurements?

    NASA Astrophysics Data System (ADS)

    Matamoros García, Carlos H.

    2006-02-01

    Traceability to national standards provides confidence in measurements results, granting a guaranty when carrying out governmental rules and when demonstrating conformity with quality requirements such as ISO 9000 or ISO/IEC 17025 (and the Mexican equivalent standards). The appropriate traceability contributes with confidence of the quality of products or services. This paper presents different ways to obtain traceability in Mexico for the optical radiation measurements, mentioning some applications, and highlighting the necessity of having traceability to the appropriate units of the SI. Additionally it present the national standards maintained by Centro Nacional de Metrologia (CENAM), the national metrology institute in Mexico, that give the technical support to Mexican measurements in this field and the international recognition that the personal of the Optics and Radiometry Division had gained in 10 years of development.

  12. Sensor intercomparison of distributed surface radiation measurement system

    NASA Astrophysics Data System (ADS)

    Dou, Baocheng; Wen, Jianguang; Li, Xiuhong; Liu, Qiang; Xiao, Qing; Bai, Junhua; Peng, Jingjing; Lin, Xingwen; Zhang, Zhigang; Wu, Xiaodan; Cai, Erli; Zhang, Jialin; Chang, Chongyan

    2015-12-01

    The Wireless Sensor Networks of Coarse-resolution Pixel Parameters (CPP-WSN) was established to monitor the heterogeneity of coarse spatial resolution pixel, with consideration of different categories of land surface parameters in Huailai, Hebei province, China (40.349°N, 115.785°E). The observation network of radiation parameters (RadNet) in CPP-WSN was developed for multi-band radiation measurement and consisted of 6 nodes covering 2km*2km area to capture its heterogeneity. Each node employed four sensors to observe the five radiation parameters. The number and location of nodes in RadNet were determined through the representativeness-based sampling method. Thus, the RadNet is a distributed observation system with nodes work synchronously and measurements used together. The intercomparison experiment for RadNet is necessary and was conducted in Huailai Remote Sensing Station from 5th Aug to 10th Aug in 2012. Time series observations from various sensors were collected and analyzed. The maximum relative differences among sensors of UVR, SWR, LWR, PAR, and LST are 4.83%, 5.3%, 3.71%, 11%, and 0.54%, respectively. Sensor/parameter differences indeed exist and are considerable large for PAR, SWR, UVR, and LWR, which cannot be ignored. The linear normalization and quadratic polynomial normalization perform similar for CUV5/UVR, PQS1/PAR, CNR4/SWR, and SI-111/LST. As for CNR4/LWR, quadratic polynomial normalization show higher accuracy than linear normalization, especially in node2, node4, and node5. Thus, the LWR measured by CNR4 is proved to be nonlinear, and should be normalized with quadratic polynomial coefficients for higher precision.

  13. Intercomparison of Shortwave Radiative Transfer Codes and Measurements

    SciTech Connect

    Halthore, Rangasayi N.; Crisp, David; Schwartz, Stephen E.; Anderson, Gail; Berk, A.; Bonnel, B.; Boucher, Olivier; Chang, Fu-Lung; Chou, Ming-Dah; Clothiaux, Eugene E.; Dubuisson, P.; Fomin, Boris; Fouquart, Y.; Freidenreich, S.; Gautier, Catherine; Kato, Seiji; Laszlo, Istvan; Li, Zhanqing; Mather, Jim H.; Plana-Fattori, Artemio; Ramaswamy, V.; Ricchiazzi, P.; Shiren, Y.; Trishchenko, A.; Wiscombe, Warren J.

    2005-06-03

    Computation of components of shortwave (SW) or solar irradiance in the surface-atmospheric system forms the basis of intercomparison between 16 radiative transfer models of varying spectral resolution ranging from line-by-line models to broadband and general circulation models. In order of increasing complexity the components are: direct solar irradiance at the surface, diffuse irradiance at the surface, diffuse upward flux at the surface, and diffuse upward flux at the top of the atmosphere. These components allow computation of the atmospheric absorptance. Four cases are considered from pure molecular atmospheres to atmospheres with aerosols and atmosphere with a simple uniform cloud. The molecular and aerosol cases allow comparison of aerosol forcing calculation among models. A cloud-free case with measured atmospheric and aerosol properties and measured shortwave radiation components provides an absolute basis for evaluating the models. For the aerosol-free and cloud-free dry atmospheres, models agree to within 1% (root mean square deviation as a percentage of mean) in broadband direct solar irradiance at surface; the agreement is relatively poor at 5% for a humid atmosphere. A comparison of atmospheric absorptance, computed from components of SW radiation, shows that agreement among models is understandably much worse at 3% and 10% for dry and humid atmospheres, respectively. Inclusion of aerosols generally makes the agreement among models worse than when no aerosols are present, with some exceptions. Modeled diffuse surface irradiance is higher than measurements for all models for the same model inputs. Inclusion of an optically thick low-cloud in a tropical atmosphere, a stringent test for multiple scattering calculations, produces, in general, better agreement among models for a low solar zenith angle (SZA = 30?) than for a high SZA (75?). All models show about a 30% increase in broadband absorptance for 30? SZA relative to the clear-sky case and almost no

  14. The next step in Earth radiation budget measurements

    NASA Astrophysics Data System (ADS)

    Wiscombe, Warren; Chiu, Christine

    2013-05-01

    Space-based Earth Radiation Budget (ERB) measurements are ready to take their next major evolutionary step beyond the ERBE three-satellite constellation of the 1980s. This step would complete the ERBE vision by using not just three but dozens of satellites, and it would complete the GERB vision by providing global diurnal cycle. Such a large constellation would measure true diurnal cycle, without long chains of assumptions and extrapolations, allowing ERB to take its place alongside the other synoptic variables that are assimilated in weather and climate models, and bringing ERB back to a forefront research area. This constellation approach would make it possible to study ERB for rapidly evolving large-scale phenomena. It would also allow, for the first time, the measurement of the true Earth Radiation Imbalance, a crucial quantity, much in the news of late, for testing climate models and for predicting the future course of global warming. Among many side benefits, the greatest would be that all interested nations could participate. Such nations would merely need to meet the instrument functional requirements and find rides to space, and the system could thus grow with time, allowing continuously improved sampling, rapid deployment of new technologies with minimal damage to data continuity, and economies of scale. This is really the perfect ERB system for a budget-constrained decade.

  15. ACCURATE TEMPERATURE MEASUREMENTS IN A NATURALLY-ASPIRATED RADIATION SHIELD

    SciTech Connect

    Kurzeja, R.

    2009-09-09

    Experiments and calculations were conducted with a 0.13 mm fine wire thermocouple within a naturally-aspirated Gill radiation shield to assess and improve the accuracy of air temperature measurements without the use of mechanical aspiration, wind speed or radiation measurements. It was found that this thermocouple measured the air temperature with root-mean-square errors of 0.35 K within the Gill shield without correction. A linear temperature correction was evaluated based on the difference between the interior plate and thermocouple temperatures. This correction was found to be relatively insensitive to shield design and yielded an error of 0.16 K for combined day and night observations. The correction was reliable in the daytime when the wind speed usually exceeds 1 m s{sup -1} but occasionally performed poorly at night during very light winds. Inspection of the standard deviation in the thermocouple wire temperature identified these periods but did not unambiguously locate the most serious events. However, estimates of sensor accuracy during these periods is complicated by the much larger sampling volume of the mechanically-aspirated sensor compared with the naturally-aspirated sensor and the presence of significant near surface temperature gradients. The root-mean-square errors therefore are upper limits to the aspiration error since they include intrinsic sensor differences and intermittent volume sampling differences.

  16. Measurement of solar UV radiation in Antarctica with collagen sheets.

    PubMed

    Takahashi, Tetsuya; Kondo, Tetsuo; Tanaka, Keisuke; Hattori, Shunji; Irie, Shinkichi; Kudoh, Sakae; Imura, Satoshi; Kanda, Hiroshi

    2012-07-01

    Collagen sheets were used in a unique evaluation method to examine skin damage caused by ultraviolet (UV) light of short wavelength during a season of the Antarctic ozone hole. The collagen sheets were exposed outdoors for 25 and 50 d, in the spring when the ozone hole was formed and in the ozone-hole-free autumn. Extracts from the exposed collagen sheets were analyzed for total protein and terminal amino acid concentrations as an index of collagen fragmentation. The results show that the amount of extractable collagen and terminal amino acid concentration in the spring exposure were approximately double and five times higher, respectively, when compared with those in the autumn exposure. During the ozone hole occurrence, the terminal amino acid concentration of the extracted collagen was about five times higher when exposure lasted 50 d from mid-September to the end of October compared to when exposure lasted 25 d from mid-September to early October. This result could be attributed to a limited amount of short-wavelength UV radiation reaching the ground surface as a result of the low height of the sun in September, when the ozone hole occurred. In fact, UV radiation measurements taken at Syowa Station indicate that short-wavelength UV radiation in the range 290-295 nm was not detected until approximately 1-2 months after the beginning of the ozone hole occurrence. PMID:22419356

  17. Comparisons of Air Radiation Model with Shock Tube Measurements

    NASA Technical Reports Server (NTRS)

    Bose, Deepak; McCorkle, Evan; Bogdanoff, David W.; Allen, Gary A., Jr.

    2009-01-01

    This paper presents an assessment of the predictive capability of shock layer radiation model appropriate for NASA s Orion Crew Exploration Vehicle lunar return entry. A detailed set of spectrally resolved radiation intensity comparisons are made with recently conducted tests in the Electric Arc Shock Tube (EAST) facility at NASA Ames Research Center. The spectral range spanned from vacuum ultraviolet wavelength of 115 nm to infrared wavelength of 1400 nm. The analysis is done for 9.5-10.5 km/s shock passing through room temperature synthetic air at 0.2, 0.3 and 0.7 Torr. The comparisons between model and measurements show discrepancies in the level of background continuum radiation and intensities of atomic lines. Impurities in the EAST facility in the form of carbon bearing species are also modeled to estimate the level of contaminants and their impact on the comparisons. The discrepancies, although large is some cases, exhibit order and consistency. A set of tests and analyses improvements are proposed as forward work plan in order to confirm or reject various proposed reasons for the observed discrepancies.

  18. Radiation-driven Outflows from and Radiative Support in Dusty Tori of Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Chan, Chi-Ho; Krolik, Julian H.

    2016-07-01

    Substantial evidence points to dusty, geometrically thick tori obscuring the central engines of active galactic nuclei (AGNs), but so far no mechanism satisfactorily explains why cool dust in the torus remains in a puffy geometry. Near-Eddington infrared (IR) and ultraviolet (UV) luminosities coupled with high dust opacities at these frequencies suggest that radiation pressure on dust can play a significant role in shaping the torus. To explore the possible effects of radiation pressure, we perform three-dimensional radiative hydrodynamics simulations of an initially smooth torus. Our code solves the hydrodynamics equations, the time-dependent multi–angle group IR radiative transfer (RT) equation, and the time-independent UV RT equation. We find a highly dynamic situation. IR radiation is anisotropic, leaving primarily through the central hole. The torus inner surface exhibits a break in axisymmetry under the influence of radiation and differential rotation; clumping follows. In addition, UV radiation pressure on dust launches a strong wind along the inner surface; when scaled to realistic AGN parameters, this outflow travels at ˜ 5000 {(M/{10}7{M}ȯ )}1/4 {[{L}{UV}/(0.1{L}{{E}})]}1/4 {km} {{{s}}}-1 and carries ˜ 0.1 {(M/{10}7{M}ȯ )}3/4 {[{L}{UV}/(0.1{L}{{E}})]}3/4 M ⊙ yr‑1, where M, {L}{UV}, and {L}{{E}} are the mass, UV luminosity, and Eddington luminosity of the central object respectively.

  19. Gamma rays and supernova explosions. [high temperature radiation measurement

    NASA Technical Reports Server (NTRS)

    Arnett, W. D.

    1977-01-01

    Thermal radiation associated with the explosion of supernovae is investigated. High temperature is required to produce copious gamma radiation of this sort. It appears that type 11 supernovae do not release much of their energy as gamma ray continuum radiation.

  20. Measurement of soil moisture using remote sensing multisensor radiation techniques

    NASA Technical Reports Server (NTRS)

    Waite, W. P. (Principal Investigator)

    1982-01-01

    Theoretical modeling as well as laboratory and field measurement were coupled with analysis of aircraft data obtained from controlled sites in an effort to enhance understanding of the microwave response due to soil moisture so as to specify sensor parameters and develop inversion algorithms. Models to predict the complex dielectric constant were produced which led to the interpretation of the results in terms of a matrix potential rather than simply moisture content. Similar advances were made in the development of coherent and incoherent radiative transfer models and rough surface scattering models.

  1. New Measurements of the Cosmic Background Radiation Spectrum

    SciTech Connect

    Smoot, G.F.; De Amici, G.; Levin, S.; Witebsky, C.

    1984-12-01

    We have continued our program to measure the long-wavelength spectrum of the cosmic background radiation. Our previous observations were at five wavelengths--0.33, 0.9, 3.0, 6.3, and 12.0 cm--and had a weighted average value of 2.73 {+-} 0.05 K and deviated from a Planckian spectrum by less than 6%. In August 1984, we repeated our observations at 3.0, 0.9, and 0.33 cm and made new observations with a radiometer tunable from 1.7 to 15 cm. Preliminary analysis indicate that the new data are consistent with our previous results.

  2. Maser radiometer for cosmic background radiation anisotropy measurements

    NASA Astrophysics Data System (ADS)

    Fixsen, D. J.; Wilkinson, D. T.

    1982-06-01

    A maser amplifier was incorporated into a low noise radiometer designed to measure large-scale anisotropy in the 3 deg K microwave background radiation. To minimize emission by atmospheric water vapor and oxygen, the radiometer is flown in a small balloon to an altitude to 25 km. Three successful flights were made - two from Palestine, Texas and one from Sao Jose dos Campos, Brazil. Good sky coverage is important to the experiment. Data from the northern hemisphere flights has been edited and calibrated.

  3. Maser radiometer for cosmic background radiation anisotropy measurements

    NASA Technical Reports Server (NTRS)

    Fixsen, D. J.; Wilkinson, D. T.

    1982-01-01

    A maser amplifier was incorporated into a low noise radiometer designed to measure large-scale anisotropy in the 3 deg K microwave background radiation. To minimize emission by atmospheric water vapor and oxygen, the radiometer is flown in a small balloon to an altitude to 25 km. Three successful flights were made - two from Palestine, Texas and one from Sao Jose dos Campos, Brazil. Good sky coverage is important to the experiment. Data from the northern hemisphere flights has been edited and calibrated.

  4. Activation energy measurements of cheese

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperature sweeps of cheeses using small amplitude oscillatory shear tests produced values for activation energy of flow (Ea) between 30 and 44 deg C. Soft goat cheese and Queso Fresco, which are high-moisture cheeses and do not flow when heated, exhibited Ea values between 30 and 60 kJ/mol. The ...

  5. Atmospheric Radiation Measurement Program facilities newsletter, July 2001.

    SciTech Connect

    Holdridge, D. J.

    2001-07-23

    Global Warming and Methane--Global warming, an increase in Earth's near-surface temperature, is believed to result from the buildup of what scientists refer to as ''greenhouse gases.'' These gases include water vapor, carbon dioxide, methane, nitrous oxide, ozone, perfluorocarbons, hydrofluoro-carbons, and sulfur hexafluoride. Greenhouse gases can absorb outgoing infrared (heat) radiation and re-emit it back to Earth, warming the surface. Thus, these gases act like the glass of a greenhouse enclosure, trapping infrared radiation inside and warming the space. One of the more important greenhouse gases is the naturally occurring hydrocarbon methane. Methane, a primary component of natural gas, is the second most important contributor to the greenhouse effect (after carbon dioxide). Natural sources of methane include wetlands, fossil sources, termites, oceans, fresh-waters, and non-wetland soils. Methane is also produced by human-related (or anthropogenic) activities such as fossil fuel production, coal mining, rice cultivation, biomass burning, water treatment facilities, waste management operations and landfills, and domesticated livestock operations (Figure 1). These anthropogenic activities account for approximately 70% of the methane emissions to the atmosphere. Methane is removed naturally from the atmosphere in three ways. These methods, commonly referred to as sinks, are oxidation by chemical reaction with tropospheric hydroxyl ion, oxidation within the stratosphere, and microbial uptake by soils. In spite of their important role in removing excess methane from the atmosphere, the sinks cannot keep up with global methane production. Methane concentrations in the atmosphere have increased by 145% since 1800. Increases in atmospheric methane roughly parallel world population growth, pointing to anthropogenic sources as the cause (Figure 2). Increases in the methane concentration reduce Earth's natural cooling efficiency by trapping more of the outgoing

  6. Environmental assessment for the Atmospheric Radiation Measurement (ARM) Program: Southern Great Plains Cloud and Radiation Testbed (CART) site

    SciTech Connect

    Policastro, A.J.; Pfingston, J.M.; Maloney, D.M.; Wasmer, F.; Pentecost, E.D.

    1992-03-01

    The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth`s atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy`s Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climate change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described.

  7. Atmospheric transmittance model for photosynthetically active radiation

    SciTech Connect

    Paulescu, Marius; Stefu, Nicoleta; Gravila, Paul; Paulescu, Eugenia; Boata, Remus; Pacurar, Angel; Mares, Oana; Pop, Nicolina; Calinoiu, Delia

    2013-11-13

    A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, Ångström's turbidity coefficient and single scattering albedo. Comparison with other models and ground measured data shows a reasonable level of accuracy for this model, making it suitable for practical applications. From the computational point of view the calculus is condensed into simple algebra which is a noticeable advantage. For users interested in speed-intensive computation of the effective PAR solar irradiance, a PC program based on the parametric equations along with a user guide are available online at http://solar.physics.uvt.ro/srms.

  8. Femtosecond electron beam generation and measurement for laser synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Uesaka, Mitsuru; Kinoshita, Kenichi; Watanabe, Takahiro; Ueda, Toru; Yoshii, Koji; Harano, Hideki; Nakajima, Kazuhisa; Ogata, Atsushi; Sakai, Fumio; Kotaki, Hideyuki; Kando, Masaki; Dewa, Hideki; Kondo, Shuji; Shibata, Yukio; Ishi, Kimihiro; Ikezawa, Mikio

    1998-02-01

    One of the S-band twin linacs (18L linac) of Nuclear Engineering Research Laboratory of University of Tokyo is modified in order to produce femtosecond electron single bunch for femtosecond X-ray generation via Thomson backward scattering, namely laser synchrotron radiation. Laser photocathode RF gun and chicane-type magnetic pulse compressor are installed at the S-band linac. 10 ps (FWHM) laser pulse generates 5 MeV, 10 ps (FWHM), 1 nC electron single bunch, which is accelerated up to 20 MeV in the S-band accelerating tube and compressed to 200 fs (FWHM) by the chicane. Design study has been performed by using the code of PARMELA and the installation has been finished. For precise and reliable measurement of the compressed pulse length, the comparison of measurement between the femtosecond streak camera and coherent transition radiation interferometry was carried out. Good agreement between them for 1-10 ps (FWHM) pulses was achieved. A new Michelson interferometer for the 200 fs pulse is now under construction.

  9. Atmospheric Radiation Measurement (ARM) Data from the ARM Aerial Facility

    DOE Data Explorer

    The Atmospheric Radiation Measurement (ARM) Program is the largest global change research program supported by the U.S. Department of Energy. The primary goal of the ARM Program is to improve the treatment of cloud and radiation physics in global climate models in order to improve the climate simulation capabilities of these models. ARM data is collected both through permanent monitoring stations and field campaigns around the world. Airborne measurements required to answer science questions from researchers or to validate ground data are also collected. To find data from all categories of aerial operations, follow the links from the AAF information page at http://www.arm.gov/sites/aaf. Tables of information will provide start dates, duration, lead scientist, and the research site for each of the named campaigns. The title of a campaign leads, in turn, to a project description, contact information, and links to the data. Users will be requested to create a password, but the data files are free for viewing and downloading. The ARM Archive physically resides at the Oak Ridge National Laboratory.

  10. Cloud cover models derived from satellite radiation measurements

    NASA Technical Reports Server (NTRS)

    Bean, S. J.; Somerville, P. N.

    1979-01-01

    Using daily measurement of day and night infrared and incoming and absorbed solar radiation obtained from a TIROS satellite over a period of approximately 45 months, and integrated over 2.5 degree latitude-longitude grids, the proportion of cloud cover over each grid each day was derived for the entire period. For each of four three-month periods, estimates a and b of the two parameters of the best-fit beta distribution were obtained for each grid location. The (a,b) plane was divided into a number of regions. All the geographical locations whose (a,b) estimates were in the same region in the (a,b) plane were said to have the same cloud cover type for that season. For each season, the world was thus divided into separate cloud cover types. Using estimates of mean cloud cover for each season, the world was again divided into separate cloud cover types. The process was repeated for standard deviations. Thus for each season, three separate cloud cover models were obtained using the criteria of shape of frequency distribution, mean cloud cover, and variability of cloud cover. The cloud cover statistics were derived from once-a-day, near-local-noon satellite radiation measurements.

  11. Visualization of Radiation Environment on Mars: Assessment with MARIE Measurements

    NASA Technical Reports Server (NTRS)

    Saganti, P.; Cucinotta, F.; Zeitlin, C.; Cleghorn, T.; Flanders, J.; Riman, F.; Hu, X.; Pinsky, L.; Lee, K.; Anderson, V.; Atwell, W.; Turner, R.

    2003-01-01

    For a given GCR (Galactic Cosmic Ray) environment at Mars, particle flux of protons, alpha particles, and heavy ions, are also needed on the surface of Mars for future human exploration missions. For the past twelve months, the MARJE (Martian Radiation Environment Experiment) instrument onboard the 200J Mars Odyssey has been providing the radiation measurements from the Martian orbit. These measurements are well correlated with the HZETRN (High Z and Energy Transport) and QMSFRG (Quantum Multiple-Scattering theory of nuclear Fragmentation) model calculations. These model calculations during these specific GCR environment conditions are now extended and transported through the CO2 atmosphere onto the Martian surface. These calculated pa11icle flux distributions are presented as a function of the Martian topography making use of the MOLA (Mars Orbiter Laser Altimeter) data from the MGS (Mars Global Surveyor). Also, particle flux calculations are presented with visualization in the human body from skin depth to the internal organs including the blood-forming organs.

  12. Smart measurement system for an environmental radiation monitoring

    NASA Astrophysics Data System (ADS)

    Lee, Wanno; Kim, Hee-Reyoung; Chung, Kun-Ho; Kim, Eun-Han; Cho, Young Hyun; Choi, Geun Sik; Lee, Chang Woo

    2007-08-01

    A smart measurement system for an on-line gamma monitoring has been developed to overcome the problems of a conventional system which cannot automatically restore the previous-lost data of several posts by a radio telemetry. It is similar to the conventional system except for a new electronic circuit board and an integrated operation program. The new electronic circuit board is able to store the radiation data with a time tag of 6 or more months if the recording interval time is 10 s. The operation program automatically sends the time correction command to the six monitoring posts for a daily synchronization between the monitoring posts and the central control computer as a Korean mean time. The previous-lost radiation data for 6 or more months could be restored by using two components with the functions of a time tag and a daily synchronization without any additional equipment. It was tested for more than 1 year, from which the test results, the data collection rate was dramatically improved without any tedious manual work, which was almost about 100% for 1 year. The smart measurement system has been applied for an effective gamma monitoring around the nuclear facilities at KAERI since it was developed and tested in 2003.

  13. Martian Radiation Environment: Model Calculations and Recent Measurements with "MARIE"

    NASA Technical Reports Server (NTRS)

    Saganti, P. B.; Cucinotta, F. A.; zeitlin, C. J.; Cleghorn, T. F.

    2004-01-01

    The Galactic Cosmic Ray spectra in Mars orbit were generated with the recently expanded HZETRN (High Z and Energy Transport) and QMSFRG (Quantum Multiple-Scattering theory of nuclear Fragmentation) model calculations. These model calculations are compared with the first eighteen months of measured data from the MARIE (Martian Radiation Environment Experiment) instrument onboard the 2001 Mars Odyssey spacecraft that is currently in Martian orbit. The dose rates observed by the MARIE instrument are within 10% of the model calculated predictions. Model calculations are compared with the MARIE measurements of dose, dose-equivalent values, along with the available particle flux distribution. Model calculated particle flux includes GCR elemental composition of atomic number, Z = 1-28 and mass number, A = 1-58. Particle flux calculations specific for the current MARIE mapping period are reviewed and presented.

  14. Measurements of prompt radiation induced conductivity of alumina and sapphire.

    SciTech Connect

    Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, Eric F.

    2011-04-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Alumina and Sapphire at the Little Mountain Medusa LINAC facility in Ogden, UT. Five mil thick samples were irradiated with pulses of 20 MeV electrons, yielding dose rates of 1E7 to 1E9 rad/s. We applied variable potentials up to 1 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 1E10 and 1E9 mho/m/(rad/s), depending on the dose rate and the pulse width for Alumina and 1E7 to 6E7 mho/m/(rad/s) for Sapphire.

  15. Miniature Tissue Equivalent Proportional Counter dosimeter for active personal radiation monitoring of astronauts

    NASA Astrophysics Data System (ADS)

    Watson Huber, Aubrey

    The accurate measurement of spaceflight crew radiation exposure is of utmost importance. If onboard instrumentation shows that the pre-determined limit for radiation exposure has been met or exceeded during a mission, that mission can be greatly affected by the implementation of precautionary measures, or, in more extreme cases, the crew's health being negatively affected. Large active regional monitors determine real-time radiation risks of the crew during spaceflight, while small passive personal badges detect individual astronaut total exposure levels upon their return to Earth. At present, there are no personal active radiation dosimeters that can assess the continuous radiation risk to individual astronauts during spaceflight. Personal active radiation devices would be ideal for current operations in low-Earth orbit (LEO), as well as upcoming extravehicular activities on the Moon, Mars, or other planetary bodies. This project focused on the miniaturization of the Tissue Equivalent Proportional Counters (TEPCs) presently being utilized on the International Space Station (ISS) and Space Shuttle, enabling them to become personal crew dosimeters. The miniaturized TEPC prototype design has dimensions of 7.6 x 10.1 x 2.54 cm (3 x 4 x 1 in). It is composed of a 3 x 4 array of 1.27 cm (0.5 in) spherical detectors for measurements equivalent to a 4.39 cm (1.73 in) spherical detector, with an additional standalone sphere of diameter 1.27 cm (0.5 in) for taking measurements in high-flux environments. The detector simulates a tissue-equivalent diameter of 2 microns, is sensitive to lineal energies of 0.3 -- 1000 keV/micron, and can measure charged particles and neutrons ranging from 0.01 -- 100 mGy/hr.

  16. Radiation inactivation study of aminopeptidase: probing the active site

    NASA Astrophysics Data System (ADS)

    Jamadar, V. K.; Jamdar, S. N.; Mohan, Hari; Dandekar, S. P.; Harikumar, P.

    2004-04-01

    Ionizing radiation inactivated purified chicken intestinal aminopeptidase in media saturated with gases in the order N 2O>N 2>air. The D 37 values in the above conditions were 281, 210 and 198 Gy, respectively. OH radical scavengers such as t-butanol and isopropanol effectively nullified the radiation-induced damage in N 2O. The radicals (SCN) 2•-, Br 2•- and I 2•- inactivated the enzyme, pointing to the involvement of aromatic amino acids and cysteine in its catalytic activity. The enzyme exhibited fluorescence emission at 340 nm which is characteristic of tryptophan. The radiation-induced loss of activity was accompanied by a decrease in the fluorescence of the enzyme suggesting a predominant influence on tryptophan residues. The enzyme inhibition was associated with a marked increase in the Km and a decrease in the Vmax and kcat values, suggesting an irreversible alteration in the catalytic site. The above observations were confirmed by pulse radiolysis studies.

  17. Method and apparatus for measuring solar radiation in a vegetative canopy

    DOEpatents

    Gutschick, V.P.; Barron, M.H.; Waechter, D.A.; Wolf, M.A.

    1985-04-30

    An apparatus and method for measuring solar radiation received in a vegetative canopy. A multiplicity of sensors selectively generates electrical signals in response to impinging photosynthetically active radiation in sunlight. Each sensor is attached to a plant within the canopy and is electrically connected to a separate port in a junction box having a multiplicity of ports. Each port is connected to an operational amplifier. Each amplifier amplifies the signals generated by the sensors. Each amplifier is connected to an analog-to-digital convertor which digitizes each signal. A computer is connected to the convertors and accumulates and stores solar radiation data. A data output device such as a printer is connected to the computer and displays the data.

  18. Method and apparatus for measuring solar radiation in a vegetative canopy

    DOEpatents

    Gutschick, Vincent P.; Barron, Michael H.; Waechter, David A.; Wolf, Michael A.

    1987-01-01

    An apparatus and method for measuring solar radiation received in a vegetative canopy. A multiplicity of sensors selectively generates electrical signals in response to impinging photosynthetically active radiation in sunlight. Each sensor is attached to a plant within the canopy and is electrically connected to a separate port in a junction box having a multiplicity of ports. Each port is connected to an operational amplifier. Each amplifier amplifies the signals generated by the sensors. Each amplifier is connected to an analog-to-digital convertor which digitizes each signal. A computer is connected to the convertors and accumulates and stores solar radiation data. A data output device such as a printer is connected to the computer and displays the data.

  19. A Strategy to Assess Aerosol Direct Radiative Forcing of Climate Using Satellite Radiation Measurements

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Tanre, Didier; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Atmospheric aerosols have a complex internal chemical composition and optical properties. Therefore it is difficult to model their impact on redistribution and absorption of solar radiation, and the consequent impact on atmospheric dynamics and climate. The use in climate models of isolated aerosol parameters retrieved from satellite data (e.g. optical thickness) may result in inconsistent calculations, if the model assumptions differ from these of the satellite retrieval schemes. Here we suggest a strategy to assess the direct impact of aerosol on the radiation budget at the top and bottom of the atmosphere using satellite and ground based measurements of the spectral solar radiation scattered by the aerosol. This method ensures consistent use of the satellite data and increases its accuracy. For Kaufman and Tanre: Strategy for aerosol direct forcing anthropogenic aerosol in the fine mode (e.g. biomass burning smoke and urban pollution) consistent use of satellite derived optical thickness can yield the aerosol impact on the spectral solar flux with accuracy an order of magnitude better than the optical thickness itself. For example, a simulated monthly average smoke optical thickness of 0.5 at 0.55 microns (forcing of 40-50 W/sq m) derived with an error of 20%, while the forcing can be measured directly with an error of only 0-2 W/sq m. Another example, the effect of large dust particles on reflection of solar flux can be derived three times better than retrievals of optical thickness. Since aerosol impacts not only the top of the atmosphere but also the surface irradiation, a combination of satellite and ground based measurements of the spectral flux, can be the most direct mechanism to evaluate the aerosol effect on climate and assimilate it in climate models. The strategy is applied to measurements from SCAR-B and the Tarfox experiments. In SCAR-B aircraft spectral data are used to derive the 24 hour radiative forcing of smoke at the top of the atmosphere of

  20. Measurement of energetic radiation generated during thunderstorm by a sounding balloon and an airplane

    NASA Astrophysics Data System (ADS)

    Torii, Tatsuo; Sanada, Yukihisa; Nishizawa, Yukiyasu; Yamada, Tsutomu; Orita, Tadashi; Muraoka, Koji; Sato, Masayuki; Watanabe, Akira

    2015-04-01

    Energetic radiation caused by thunderstorm activity is observed at various places, such as the ground, high mountain areas, and artificial satellites. In order to investigate the source location of the radiation and its energy distribution, we observed radiation using a sounding balloon and an airplane in the inside and above the thundercloud which would be near a source of radiation. On the measurement in the thundercloud, we conducted a sounding observation using a radiosonde mounted two GM tubes (for gamma-rays, and for beta/gamma-rays), besides meteorological instruments. The balloon passed through a region of strong echoes in a thundercloud shown by radar image, at which time an increase in counting rate of the GM tube about 2 orders of magnitude occurred at the altitude from 5 km to 7.5 km. Furthermore, the counting rate of 2 GM tubes indicated the tendency different depending on movement of a balloon. This result suggests that the ratio for the gamma-rays (energetic photons) of the beta-rays (energetic electrons) varies according to the place in the thundercloud. Then, we measured the variation of the energetic radiation from the top of the thundercloud using an airplane. At this time, we used two NaI detectors different in the size -- the large one is with the size of 5 inches (12.7cmφ ×12.7cm) to detect the energetic radiation (< 30 MeV) that will be emitted from strong electric field in a thundercloud, and 3 inches (7.62cmφ×7.62cm) detector for the measurement of low energy gamma-rays( < 3 MeV). We performed the radiation measurement by flying around the thunderclouds at 12 -- 14 km in height by the observation in the summer. Furthermore, in the winter season, we flew 5 -- 6 km in height and measured the radiation around the thunderclouds. The event that the counting rate was slightly exceeding a normal variation was observed by a result of the winter observation. About the cause, we are analyzing it now. We report the result of these measurements and

  1. Solar irradiance measurements - Minimum through maximum solar activity

    NASA Technical Reports Server (NTRS)

    Lee, R. B., III; Gibson, M. A.; Shivakumar, N.; Wilson, R.; Kyle, H. L.; Mecherikunnel, A. T.

    1991-01-01

    The Earth Radiation Budget Satellite (ERBS) and the NOAA-9 spacecraft solar monitors were used to measure the total solar irradiance during the period October 1984 to December 1989. Decreasing trends in the irradiance measurements were observed as sunspot activity decreased to minimum levels in 1986; after 1986, increasing trends were observed as sunspot activity increased. The magnitude of the irradiance variability was found to be approximately 0.1 percent between sunspot minimum and maximum (late 1989). When compared with the 1984 to 1989 indices of solar magnetic activity, the irradiance trends appear to be in phase with the 11-year sunspot cycle. Both irradiance series yielded 1,365/sq Wm as the mean value of the solar irradiance, normalized to the mean earth/sun distance. The monitors are electrical substitution, active-cavity radiometers with estimated measurement precisions and accuracies of less than 0.02 and 0.2 percent, respectively.

  2. Changes in biologically active ultraviolet radiation reaching the Earth's surface.

    PubMed

    Madronich, S; McKenzie, R L; Björn, L O; Caldwell, M M

    1998-10-01

    Stratospheric ozone levels are near their lowest point since measurements began, so current ultraviolet-B (UV-B) radiation levels are thought to be close to their maximum. Total stratospheric content of ozone-depleting substances is expected to reach a maximum before the year 2000. All other things being equal, the current ozone losses and related UV-B increases should be close to their maximum. Increases in surface erythemal (sunburning) UV radiation relative to the values in the 1970s are estimated to be: about 7% at Northern Hemisphere mid-latitudes in winter/spring; about 4% at Northern Hemisphere mid-latitudes in summer/fall; about 6% at Southern Hemisphere mid-latitudes on a year-round basis; about 130% in the Antarctic in spring; and about 22% in the Arctic in spring. Reductions in atmospheric ozone are expected to result in higher amounts of UV-B radiation reaching the Earth's surface. The expected correlation between increases in surface UV-B radiation and decreases in overhead ozone has been further demonstrated and quantified by ground-based instruments under a wide range of conditions. Improved measurements of UV-B radiation are now providing better geographical and temporal coverage. Surface UV-B radiation levels are highly variable because of cloud cover, and also because of local effects including pollutants and surface reflections. These factors usually decrease atmospheric transmission and therefore the surface irradiances at UV-B as well as other wavelengths. Occasional cloud-induced increases have also been reported. With a few exceptions, the direct detection of UV-B trends at low- and mid-latitudes remains problematic due to this high natural variability, the relatively small ozone changes, and the practical difficulties of maintaining long-term stability in networks of UV-measuring instruments. Few reliable UV-B radiation measurements are available from pre-ozone-depletion days. Satellite-based observations of atmospheric ozone and clouds are

  3. Radiation Hard Active Media R&D for CMS Hadron Endcap Calorimetry

    NASA Astrophysics Data System (ADS)

    Tiras, Emrah; CMS-HCAL Collaboration

    2015-04-01

    The High Luminosity LHC era imposes unprecedented radiation conditions on the CMS detectors targeting a factor of 5-10 higher than the LHC design luminosity. The CMS detectors will need to be upgraded in order to withstand these conditions yet maintain/improve the physics measurement capabilities. One of the upgrade options is reconstructing the CMS Endcap Calorimeters with a shashlik design electromagnetic section and replacing active media of the hadronic section with radiation-hard scintillation materials. In this context, we have studied various radiation-hard materials such as Polyethylene Naphthalate (PEN), Polyethylene Terephthalate (PET), HEM and quartz plates coated with various organic materials such as p-Terphenyl (pTp), Gallium doped Zinc Oxide (ZnO:Ga) and Anthracene. Here we discuss the related test beam activities, laboratory measurements and recent developments.

  4. Radiation exposure at sea level measurement between Rio de Janeiro and the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    De Freitas, A. C.; Alencar, A. S.; Coutinho, C. R.; Paschoa, A. S.

    2007-09-01

    A sea trip was made aboard the vessel NApOc Ary Rongel of the Brazilian Navy from Rio de Janeiro (Lat. 22°S) to Admiralty Bay (Lat. 62°S) in the King George Island in the Antarctic Peninsula. This trip was part of the Brazilian Antarctic Programme. Radiation measurements were carried out with a proportional counter along the ship round-trip route, which sailed partially under the South Atlantic Anomaly. Only those measurements, which were taken after the vessel was farther than one nautical mile offshore were used. This procedure minimizes radiation contributions from land. External radiation measurements made offshore give an indication of the secondary cosmic ray intensity at sea level. Barometric pressure measurements were registered along the round-trip route as well. Negative correlations between the measured external radiation and the barometric pressure on the vessel were observed in both ways of the round-trip. In latitudes above 42°S, the negative correlation became more prominent. In 1935 the variation of the secondary cosmic radiation with atmospheric pressure was known as the barometric paradox. Recently, an attempt was made to associate long-term variations of the surface pressure with solar activity and galactic cosmic rays. The results are discussed taking into account that as the barometric pressure increases the particle density in the atmosphere also increases. In such case, there are an increasing number of interactions with the particles produced in the hadronic showers, because of decreasing mean free path. Thus, the number of particles reaching a detector at the sea level decreases.

  5. Detailed Evaluation of MODIS Fire Radiative Power Measurements

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles

    2010-01-01

    Satellite remote sensing is providing us tremendous opportunities to measure the fire radiative energy (FRE) release rate or power (FRP) from open biomass burning, which affects many vegetated regions of the world on a seasonal basis. Knowledge of the biomass burning characteristics and emission source strengths of different (particulate and gaseous) smoke constituents is one of the principal ingredients upon which the assessment, modeling, and forecasting of their distribution and impacts depend. This knowledge can be gained through accurate measurement of FRP, which has been shown to have a direct relationship with the rates of biomass consumption and emissions of major smoke constituents. Over the last decade or so, FRP has been routinely measured from space by both the MODIS sensors aboard the polar orbiting Terra and Aqua satellites, and the SEVIRI sensor aboard the Meteosat Second Generation (MSG) geostationary satellite. During the last few years, FRP has been gaining recognition as an important parameter for facilitating the development of various scientific studies relating to the quantitative characterization of biomass burning and their emissions. Therefore, we are conducting a detailed analysis of the FRP products from MODIS to characterize the uncertainties associated with them, such as those due to the MODIS bow-tie effects and other factors, in order to establish their error budget for use in scientific research and applications. In this presentation, we will show preliminary results of the MODIS FRP data analysis, including comparisons with airborne measurements.

  6. Atmospheric Radiation Measurement Program facilities newsletter, January 2000

    SciTech Connect

    Sisterson, D.L.

    2000-02-16

    The subject of this newsletter is the ARM unmanned aerospace vehicle program. The ARM Program's focus is on climate research, specifically research related to solar radiation and its interaction with clouds. The SGP CART site contains highly sophisticated surface instrumentation, but even these instruments cannot gather some crucial climate data from high in the atmosphere. The Department of Energy and the Department of Defense joined together to use a high-tech, high-altitude, long-endurance class of unmanned aircraft known as the unmanned aerospace vehicle (UAV). A UAV is a small, lightweight airplane that is controlled remotely from the ground. A pilot sits in a ground-based cockpit and flies the aircraft as if he were actually on board. The UAV can also fly completely on its own through the use of preprogrammed computer flight routines. The ARM UAV is fitted with payload instruments developed to make highly accurate measurements of atmospheric flux, radiance, and clouds. Using a UAV is beneficial to climate research in many ways. The UAV puts the instrumentation within the environment being studied and gives scientists direct measurements, in contrast to indirect measurements from satellites orbiting high above Earth. The data collected by UAVs can be used to verify and calibrate measurements and calculated values from satellites, therefore making satellite data more useful and valuable to researchers.

  7. Simplified calibration for broadband solar ultraviolet radiation measurements.

    PubMed

    Oppenrieder, A; Hoeppe, P; Koepke, P; Reuder, J; Schween, J; Schreder, J

    2003-12-01

    Aspects of different calibration procedures for erythemally weighing broadband radiometers are presented in this study. These instruments are common in projects dealing with ultraviolet radiation effects on humans. Many erythemally weighing broadband radiometers are still operated using a single calibration factor (cf) that is provided with the instrument. The individual characteristics of every instrument are strongly dependent on the total ozone amount and the solar elevation. Therefore, a calibration procedure also has to take into account the ozone concentrations and the solar elevation to compensate for the effects of the individual characteristics and to provide comparable measurements. Given the variation of the ozone concentrations and the solar elevation, an individual cf has to be calculated for every measurement. Using a simplified version of the calibration procedure, which is presented in this study, can lessen this effort. Taking into account the relevant meteorological conditions for a measuring site, a single cf is calculated to compensate the individual characteristics of the instruments and therefore deliver comparable measurements with less effort. PMID:14743870

  8. Spatial autocorrelation of radiation measured by the Earth Radiation Budget Experiment: Scene inhomogeneity and reciprocity violation

    NASA Technical Reports Server (NTRS)

    Davies, Roger

    1994-01-01

    The spatial autocorrelation functions of broad-band longwave and shortwave radiances measured by the Earth Radiation Budget Experiment (ERBE) are analyzed as a function of view angle in an investigation of the general effects of scene inhomogeneity on radiation. For nadir views, the correlation distance of the autocorrelation function is about 900 km for longwave radiance and about 500 km for shortwave radiance, consistent with higher degrees of freedom in shortwave reflection. Both functions rise monotonically with view angle, but there is a substantial difference in the relative angular dependence of the shortwave and longwave functions, especially for view angles less than 50 deg. In this range, the increase with angle of the longwave functions is found to depend only on the expansion of pixel area with angle, whereas the shortwave functions show an additional dependence on angle that is attributed to the occlusion of inhomogeneities by cloud height variations. Beyond a view angle of about 50 deg, both longwave and shortwave functions appear to be affected by cloud sides. The shortwave autocorrelation functions do not satisfy the principle of directional reciprocity, thereby proving that the average scene is horizontally inhomogeneous over the scale of an ERBE pixel (1500 sq km). Coarse stratification of the measurements by cloud amount, however, indicates that the average cloud-free scene does satisfy directional reciprocity on this scale.

  9. Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2007

    SciTech Connect

    LR Roeder

    2007-12-01

    This annual report describes the purpose and structure of the program, and presents key accomplishments in 2007. Notable achievements include: • Successful review of the ACRF as a user facility by the DOE Biological and Environmental Research Advisory Committee. The subcommittee reinforced the importance of the scientific impacts of this facility, and its value for the international research community. • Leadership of the Cloud Land Surface Interaction Campaign. This multi-agency, interdisciplinary field campaign involved enhanced surface instrumentation at the ACRF Southern Great Plains site and, in concert with the Cumulus Humilis Aerosol Processing Study sponsored by the DOE Atmospheric Science Program, coordination of nine aircraft through the ARM Aerial Vehicles Program. • Successful deployment of the ARM Mobile Facility in Germany, including hosting nearly a dozen guest instruments and drawing almost 5000 visitors to the site. • Key advancements in the representation of radiative transfer in weather forecast models from the European Centre for Medium-Range Weather Forecasts. • Development of several new enhanced data sets, ranging from best estimate surface radiation measurements from multiple sensors at all ACRF sites to the extension of time-height cloud occurrence profiles to Niamey, Niger, Africa. • Publication of three research papers in a single issue (February 2007) of the Bulletin of the American Meteorological Society.

  10. Measurement of the radiation field surrounding the Collider Detector at Fermilab

    SciTech Connect

    K. Kordas et al.

    2004-01-28

    We present here the first direct and detailed measurements of the spatial distribution of the ionizing radiation surrounding a hadron collider experiment. Using data from two different exposures we measure the effect of additional shielding on the radiation field around the Collider Detector at Fermilab (CDF). Employing a simple model we parameterize the ionizing radiation field surrounding the detector.

  11. Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization

    SciTech Connect

    Meng, Zhen; Gan, Ye-Hua

    2015-05-01

    Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation. - Highlights: • COX-2 inhibitor, celecoxib, could enhance radiosensitization. • Radiation induced PTEN inactivation (phosphorylation) and AKT activation. • COX-2 inhibitor induced PTEN expression and activation, and inactivated AKT. • COX-2 inhibitor enhanced radiosensitization through activating PTEN.

  12. Resolution of Transverse Electron Beam Measurements using Optical Transition Radiation

    SciTech Connect

    Ischebeck, Rasmus; Decker, Franz-Josef; Hogan, Mark; Iverson, Richard H.; Krejcik, Patrick; Lincoln, Melissa; Siemann, Robert H.; Walz, Dieter; Clayton, Chris E.; Huang, Chengkun; Lu, Wei; Deng, Suzhi; Oz, Erdem; /Southern California U.

    2005-06-22

    In the plasma wakefield acceleration experiment E-167, optical transition radiation is used to measure the transverse profile of the electron bunches before and after the plasma acceleration. The distribution of the electric field from a single electron does not give a point-like distribution on the detector, but has a certain extension. Additionally, the resolution of the imaging system is affected by aberrations. The transverse profile of the bunch is thus convolved with a point spread function (PSF). Algorithms that deconvolve the image can help to improve the resolution. Imaged test patterns are used to determine the modulation transfer function of the lens. From this, the PSF can be reconstructed. The Lucy-Richardson algorithm is used to deconvolute this PSF from test images.

  13. Radiation pressure efficiency measurements of nanoparticle coated microspheres

    SciTech Connect

    Kim, Soo Y.; Taylor, Joseph D.; Ladouceur, Harold D.; Hart, Sean J.; Terray, Alex

    2013-12-02

    Experimental measurements of the radiation pressure efficiency (Q{sub pr}) for several microparticles have been compared to theoretical calculations extrapolated from the Bohren-Huffman code for Mie scattering of coated particles. An increased shift of the Q{sub pr} parameter was observed for 2 μm SiO{sub 2} core particles coated with nanoparticles of higher refractive indices. Coatings of 14 nm melamine particles were found to increase the Q{sub pr} parameter 135 times over similar coatings using SiO{sub 2} particles of the same size. While a coating of 100 nm polystyrene particles also showed a significant increase, they did not agree well with theoretical values. It is hypothesized that other factors such as increased scatter, drag, and finite coating coverage are no longer negligible for coatings using nanoparticles in this size regime.

  14. Space charge dosimeters for extremely low power measurements of radiation in shipping containers

    DOEpatents

    Britton, Jr.; Charles L.; Buckner, Mark A.; Hanson, Gregory R.; Bryan, William L.

    2011-04-26

    Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes in situ polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

  15. Space charge dosimeters for extremely low power measurements of radiation in shipping containers

    DOEpatents

    Britton, Jr., Charles L.; Buckner, Mark A.; Hanson, Gregory R.; Bryan, William L.

    2011-05-03

    Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes insitu polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

  16. Space charge dosimeters for extremely low power measurements of radiation in shipping containers

    SciTech Connect

    Buckner, Mark A; Hanson, Gregory R; Bryan, William L

    2009-04-28

    Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes insitu polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

  17. Monolithic active pixel radiation detector with shielding techniques

    DOEpatents

    Deptuch, Grzegorz W.

    2016-09-06

    A monolithic active pixel radiation detector including a method of fabricating thereof. The disclosed radiation detector can include a substrate comprising a silicon layer upon which electronics are configured. A plurality of channels can be formed on the silicon layer, wherein the plurality of channels are connected to sources of signals located in a bulk part of the substrate, and wherein the signals flow through electrically conducting vias established in an isolation oxide on the substrate. One or more nested wells can be configured from the substrate, wherein the nested wells assist in collecting charge carriers released in interaction with radiation and wherein the nested wells further separate the electronics from the sensing portion of the detector substrate. The detector can also be configured according to a thick SOA method of fabrication.

  18. Space radiation measurements on-board ISS--the DOSMAP experiment.

    PubMed

    Reitz, G; Beaujean, R; Benton, E; Burmeister, S; Dachev, Ts; Deme, S; Luszik-Bhadra, M; Olko, P

    2005-01-01

    The experiment 'Dosimetric Mapping' conducted as part of the science program of NASA's Human Research Facility (HRF) between March and August 2001 was designed to measure integrated total absorbed doses (ionising radiation and neutrons), heavy ion fluxes and its energy, mass and linear energy transfer (LET) spectra, time-dependent count rates of charged particles and their corresponding dose rates at different locations inside the US Lab at the International Space Station. Owing to the variety of particles and energies, a dosimetry package consisting of thermoluminescence dosemeter (TLD) chips and nuclear track detectors with and without converters (NTDPs), a silicon dosimetry telescope (DOSTEL), four mobile silicon detector units (MDUs) and a TLD reader unit (PILLE) with 12 TLD bulbs as dosemeters was used. Dose rates of the ionising part of the radiation field measured with TLD bulbs applying the PILLE readout system at different locations varied between 153 and 231 microGy d(-1). The dose rate received by the active devices fits excellent to the TLD measurements and is significantly lower compared with measurements for the Shuttle (STS) to MIR missions. The comparison of the absorbed doses from passive and active devices showed an agreement within +/- 10%. The DOSTEL measurements in the HRF location yielded a mean dose equivalent rate of 535 microSv d(-1). DOSTEL measurements were also obtained during the Solar Particle Event on 15 April 2001. PMID:16604663

  19. Time-Domain Measurement of Broadband Coherent Cherenkov Radiation

    SciTech Connect

    Miocinovic, P.; Field, R.C.; Gorham, P.W.; Guillian, E.; Milincic, R.; Saltzberg, D.; Walz, D.; Williams, D.; /UCLA

    2006-03-13

    We report on further analysis of coherent microwave Cherenkov impulses emitted via the Askaryan mechanism from high-energy electromagnetic showers produced at the Stanford Linear Accelerator Center (SLAC). In this report, the time-domain based analysis of the measurements made with a broadband (nominally 1-18 GHz) log periodic dipole antenna (LPDA) is described. The theory of a transmit-receive antenna system based on time-dependent effective height operator is summarized and applied to fully characterize the measurement antenna system and to reconstruct the electric field induced via the Askaryan process. The observed radiation intensity and phase as functions of frequency were found to agree with expectations from 0.75-11.5 GHz within experimental errors on the normalized electric field magnitude and the relative phase; {sigma}{sub R|E|} = 0.039 {micro}V/MHz/TeV and {sigma}{sub {phi}} = 17{sup o}. This is the first time this agreement has been observed over such a broad bandwidth, and the first measurement of the relative phase variation of an Askaryan pulse. The importance of validation of the Askaryan mechanism is significant since it is viewed as the most promising way to detect cosmogenic neutrino fluxes at E{sub v} {ge} 10{sup 15} eV.

  20. Time-domain measurement of broadband coherent Cherenkov radiation

    SciTech Connect

    Miocinovic, P.; Gorham, P. W.; Guillian, E.; Milincic, R.; Field, R. C.; Walz, D.; Saltzberg, D.; Williams, D.

    2006-08-15

    We report on further analysis of coherent microwave Cherenkov impulses emitted via the Askaryan mechanism from high-energy electromagnetic showers produced at the Stanford Linear Accelerator Center (SLAC). In this report, the time-domain based analysis of the measurements made with a broadband (nominally 1-18 GHz) log periodic dipole array antenna is described. The theory of a transmit-receive antenna system based on time-dependent effective height operator is summarized and applied to fully characterize the measurement antenna system and to reconstruct the electric field induced via the Askaryan process. The observed radiation intensity and phase as functions of frequency were found to agree with expectations from 0.75-11.5 GHz within experimental errors on the normalized electric field magnitude and the relative phase; {sigma}{sub RvertcalbarEverticalbar}=0.039 {mu}V/MHz/TeV and {sigma}{sub {phi}}=17 deg. This is the first time this agreement has been observed over such a broad bandwidth, and the first measurement of the relative phase variation of an Askaryan pulse. The importance of validation of the Askaryan mechanism is significant since it is viewed as the most promising way to detect cosmogenic neutrino fluxes at E{sub {nu}}(greater-or-similar sign)10{sup 15} eV.

  1. Experimentally Measured Radiative Lifetimes and Oscillator Strengths in Neutral Vanadium

    NASA Astrophysics Data System (ADS)

    Holmes, C. E.; Pickering, J. C.; Ruffoni, M. P.; Blackwell-Whitehead, R.; Nilsson, H.; Engström, L.; Hartman, H.; Lundberg, H.; Belmonte, M. T.

    2016-06-01

    We report a new study of the V i atom using a combination of time-resolved laser-induced fluorescence and Fourier transform spectroscopy that contains newly measured radiative lifetimes for 25 levels between 24,648 cm-1 and 37,518 cm-1 and oscillator strengths for 208 lines between 3040 and 20000 Å from 39 upper energy levels. Thirteen of these oscillator strengths have not been reported previously. This work was conducted independently of the recent studies of neutral vanadium lifetimes and oscillator strengths carried out by Den Hartog et al. and Lawler et al., and thus serves as a means to verify those measurements. Where our data overlap with their data, we generally find extremely good agreement in both level lifetimes and oscillator strengths. However, we also find evidence that Lawler et al. have systematically underestimated oscillator strengths for lines in the region of 9000 ± 100 Å. We suggest a correction of 0.18 ± 0.03 dex for these values to bring them into agreement with our results and those of Whaling et al. We also report new measurements of hyperfine structure splitting factors for three odd levels of V i lying between 24,700 and 28,400 cm-1.

  2. Solar radiation measurements and their applications in climate research

    NASA Astrophysics Data System (ADS)

    Yin, Bangsheng

    Aerosols and clouds play important roles in the climate system through their radiative effects and their vital link in the hydrological cycle. Accurate measurements of aerosol and cloud optical and microphysical properties are crucial for the study of climate and climate change. This study develops/improves retrieval algorithms for aerosol single scattering albedo (SSA) and low liquid water path (LWP) cloud optical properties, evaluates a new spectrometer, and applies long-term measurements to establish climatology of aerosol and cloud optical properties. The following results were obtained. (1) The ratio of diffuse horizontal and direct normal fluxes measured from Multifilter Rotating Shadowband Radiometer (MFRSR) has been used to derive the aerosol SSA. Various issues have impacts on the accuracy of SSA retrieval, from measurements (e.g., calibration accuracy, cosine respond correction, and forward scattering correction) to input parameters and assumptions (e.g., asymmetry factor, Rayleigh scattering optical depth, and surface albedo). This study carefully analyzed these issues and extensively assessed their impacts on the retrieval accuracy. Furthermore, the retrievals of aerosol SSA from MFRSR are compared with independent measurements from co-located instruments. (2) The Thin-Cloud Rotating Shadowband Radiometer (TCRSR) has been used to derive simultaneously the cloud optical depth (COD) and cloud drop effective radius (DER), subsequently inferring the cloud liquid-water path (LWP). The evaluation of the TCRSR indicates that the error of radiometric calibration has limited impact on the cloud DER retrievals. However, the retrieval accuracy of cloud DER is sensitive to the uncertainties of background setting (e.g., aerosol loading and the existence of ice cloud) and the measured solar aureole shape. (3) A new high resolution oxygen A-band spectrometer (HABS) has been developed, which has the ability to measure both direct-beam and zenith diffuse solar radiation

  3. Measuring solar- and greenhouse radiation profiles in the atmosphere using upper-air radiosondes

    NASA Astrophysics Data System (ADS)

    Philipona, R.; Kräuchi, A.

    2012-04-01

    Solar shortwave and thermal longwave irradiance is usually measured at the Earth's surface with ground radiation stations and at the top of the atmosphere with satellites. Here we show for the first time radiative flux profiles and the radiation budget in the atmosphere measured with radiosondes ascending from the Earth's surface to 35 km into the stratosphere. During two-hour flights solar shortwave and thermal longwave irradiance, downward and upward, is measured with four individual sensors at one-second resolution, along with standard PTU radiosonde profiles. Nighttime longwave radiation measurements are contrasted to daytime measurements and 24 hours means of radiation budget- and total net radiation profiles are shown. Of particular interest for greenhouse effect investigations are in situ measured longwave greenhouse radiation profiles and their vertical changes in relation to temperature, clouds, water vapour and other greenhouse gases.

  4. Earth radiation budget measurement from a spinning satellite: Conceptual design of detectors

    NASA Technical Reports Server (NTRS)

    Sromovsky, L. A.; Revercomb, H. E.; Suomi, V. E.

    1975-01-01

    The conceptual design, sensor characteristics, sensor performance and accuracy, and spacecraft and orbital requirements for a spinning wide-field-of-view earth energy budget detector were investigated. The scientific requirements for measurement of the earth's radiative energy budget are presented. Other topics discussed include the observing system concept, solar constant radiometer design, plane flux wide FOV sensor design, fast active cavity theory, fast active cavity design and error analysis, thermopile detectors as an alternative, pre-flight and in-flight calibration plane, system error summary, and interface requirements.

  5. Earth Radiation Budget Satellite extraterrestrial solar constant measurements - 1986-1987 increasing trend

    NASA Technical Reports Server (NTRS)

    Lee, Robert B., III; Barkstrom, Bruce R.; Harrison, Edwin F.; Gibson, Michael A.; Natarajan, Sudha M.; Edmonds, William L.; Mecherikunnel, Ann T.; Kyle, H. Lee

    1988-01-01

    From June 1986 through Nov 1987, the Earth Radiation Budget Satellite (ERBS) pyrheliometric measurements indicated that the solar constant was increasing approximately +0.02 percent per year. Earlier ERBS measurements indicated that the solar constant was declining approximately -0.03 percent per year during the 1984 through mid-1986 period. Since mid-1986 represents the beginning of solar cycle 22, it is believed that the reversal in the long-term solar constant trend may be linked to increased solar activity associated with the beginning of the 11-year sunspot cycle. The typical value of the solar constant was found to be 1365 Wm-2.

  6. Solar Radiation Modeling and Measurements for Renewable Energy Applications: Data and Model Quality; Preprint

    SciTech Connect

    Myers, D. R.

    2003-03-01

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software and for outdoor pyranometer calibrations is outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data.

  7. Resin {sup 90}Y microsphere activity measurements for liver brachytherapy

    SciTech Connect

    Dezarn, William A.; Kennedy, Andrew S.

    2007-06-15

    The measurement of the radioactivity administered to the patient is one of the major components of {sup 90}Y microsphere liver brachytherapy. The activity of {sup 90}Y microspheres in a glass delivery vial was measured in a dose calibrator. The calibration value to use for {sup 90}Y in the dose calibrator was verified using an activity calibration standard provided by the microsphere manufacturer. This method allowed for the determination of a consistent, reproducible local activity standard. Additional measurements were made to determine some of the factors that could affect activity measurement. The axial response of the dose calibrator was determined by the ratio of activity measurements at the bottom and center of the dose calibrator. The axial response was 0.964 for a glass shipping vial, 1.001 for a glass V-vial, and 0.988 for a polycarbonate V-vial. Comparisons between activity measurements in the dose calibrator and those using a radiation survey meter were found to agree within 10%. It was determined that the dose calibrator method was superior to the survey meter method because the former allowed better defined measurement geometry and traceability of the activity standard back to the manufacturer. Part of the preparation of resin {sup 90}Y microspheres for patient delivery is to draw out a predetermined activity from a shipping vial and place it into a V-vial for delivery to the patient. If the drawn activity was placed in a glass V-vial, the activity measured in the dose calibrator with a glass V-vial was 4% higher than the drawn activity from the shipping vial standard. If the drawn activity was placed in a polycarbonate V-vial, the activity measured in the dose calibrator with a polycarbonate V-vial activity was 20% higher than the drawn activity from the shipping vial standard. Careful characterization of the local activity measurement standard is recommended instead of simply accepting the calibration value of the dose calibrator manufacturer.

  8. Changes in biologically active ultraviolet radiation reaching the Earth's surface.

    PubMed

    McKenzie, Richard L; Björn, Lars Olof; Bais, Alkiviadis; Ilyasad, Mohammad

    2003-01-01

    Since publication of the 1998 UNEP Assessment, there has been continued rapid expansion of the literature on UV-B radiation. Many measurements have demonstrated the inverse relationship between column ozone amount and UV radiation, and in a few cases long-term increases due to ozone decreases have been identified. The quantity, quality and availability of ground-based UV measurements relevant to assessing the environmental impacts of ozone changes continue to improve. Recent studies have contributed to delineating regional and temporal differences due to aerosols, clouds, and ozone. Improvements in radiative transfer modelling capability now enable more accurate characterization of clouds, snow-cover, and topographical effects. A standardized scale for reporting UV to the public has gained wide acceptance. There has been increased use of satellite data to estimate geographic variability and trends in UV. Progress has been made in assessing the utility of satellite retrievals of UV radiation by comparison with measurements at the Earth's surface. Global climatologies of UV radiation are now available on the Internet. Anthropogenic aerosols play a more important role in attenuating UV irradiances than has been assumed previously, and this will have implications for the accuracy of UV retrievals from satellite data. Progress has been made inferring historical levels of UV radiation using measurements of ozone (from satellites or from ground-based networks) in conjunction with measurements of total solar radiation obtained from extensive meteorological networks. We cannot yet be sure whether global ozone has reached a minimum. Atmospheric chlorine concentrations are beginning to decrease. However, bromine concentrations are still increasing. While these halogen concentrations remain high, the ozone layer remains vulnerable to further depletion from events such as volcanic eruptions that inject material into the stratosphere. Interactions between global warming and

  9. Changes in biologically active ultraviolet radiation reaching the Earth's surface.

    PubMed

    McKenzie, Richard L; Björn, Lars Olof; Bais, Alkiviadis; Ilyasad, Mohammad

    2003-01-01

    Since publication of the 1998 UNEP Assessment, there has been continued rapid expansion of the literature on UV-B radiation. Many measurements have demonstrated the inverse relationship between column ozone amount and UV radiation, and in a few cases long-term increases due to ozone decreases have been identified. The quantity, quality and availability of ground-based UV measurements relevant to assessing the environmental impacts of ozone changes continue to improve. Recent studies have contributed to delineating regional and temporal differences due to aerosols, clouds, and ozone. Improvements in radiative transfer modelling capability now enable more accurate characterization of clouds, snow-cover, and topographical effects. A standardized scale for reporting UV to the public has gained wide acceptance. There has been increased use of satellite data to estimate geographic variability and trends in UV. Progress has been made in assessing the utility of satellite retrievals of UV radiation by comparison with measurements at the Earth's surface. Global climatologies of UV radiation are now available on the Internet. Anthropogenic aerosols play a more important role in attenuating UV irradiances than has been assumed previously, and this will have implications for the accuracy of UV retrievals from satellite data. Progress has been made inferring historical levels of UV radiation using measurements of ozone (from satellites or from ground-based networks) in conjunction with measurements of total solar radiation obtained from extensive meteorological networks. We cannot yet be sure whether global ozone has reached a minimum. Atmospheric chlorine concentrations are beginning to decrease. However, bromine concentrations are still increasing. While these halogen concentrations remain high, the ozone layer remains vulnerable to further depletion from events such as volcanic eruptions that inject material into the stratosphere. Interactions between global warming and

  10. Cloud Classes and Radiative Heating profiles at the Manus and Nauru Atmospheric Radiation Measurement (ARM) Sites

    SciTech Connect

    Mather, James H.; McFarlane, Sally A.

    2009-10-07

    The Tropical Western Pacific (TWP) is a convective regime; however, the frequency and depth of convection is dependant on dynamical forcing which exhibits variability on a range of temporal scales and also on location within the region. Manus Island, Papua New Guinea lies in the heart of the western Pacific warm pool region and exhibits frequent deep convection much of the time while Nauru, which lies approximately 20 degrees to the East of Manus, lies in a transition zone where the frequency of convection is dependent on the phase of the El Nino/Southern Oscillation. Because of this difference in dynamical regime, the distribution of clouds and the associated radiative heating is quite different at the two sites. Individual cloud types: boundary layer cumulus, thin cirrus, stratiform convective outflow, do occur at both sites – but with different frequencies. In this study we compare cloud profiles and heating profiles for specific cloud types at these two sites using data from the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF). Results of this comparison indicate that, while the frequency of specific cloud types differ between the two sites as one would expect, the characteristics of individual cloud classes are remarkably similar. This information could prove to be very useful for applying tropical ARM data to the broader region.

  11. Modular Architecture for the Measurement of Space Radiation

    NASA Technical Reports Server (NTRS)

    Delaune, Paul; Turner, Kathryn; Holland, S. Douglas; Carson, William R.; Riman, Fadi

    2007-01-01

    A modular architecture has been conceived for the design of radiation-monitoring instruments used aboard spacecraft and in planetary-exploration settings. This architecture reflects lessons learned from experience with prior radiation-monitoring instruments. A prototype instrument that embodies the architecture has been developed as part of the Mars Advanced Radiation Acquisition (MARA) project. The architecture is also applicable on Earth for radiation-monitoring instruments in research of energetic electrically charged particles and instruments monitoring radiation for purposes of safety, military defense, and detection of hidden nuclear devices and materials.

  12. Optical Spectroscopy Measurements of Shock Waves Driven by Intense Z-Pinch Radiation

    SciTech Connect

    Asay, J. Bernard, M.; Bailey, J.E.; Carlson, A.L.; Chandler, G.A.; Hall, C.A.; Hanson, D.; Johnston, R.; Lake, P.; Lawrence, J.

    1999-04-09

    Z-pinches created using the Z accelerator generate {approximately}220 TW, 1.7 MJ radiation pulses that heat large ({approximately}10 cm{sup 3}) hohlraums to 100-150 eV temperatures for times of order 10 nsec. We are performing experiments exploiting this intense radiation to drive shock waves for equation of state studies. The shock pressures are typically 1-10 Mbar with 10 nsec duration in 6-mm-diameter samples. In this paper we demonstrate the ability to perform optical spectroscopy measurements on shocked samples located in close proximity to the z-pinch. These experiments are particularly well suited to optical spectroscopy measurements because of the relatively large sample size and long duration. The optical emission is collected using fiber optics and recorded with a streaked spectrograph. Other diagnostics include VISAR and active shock breakout measurements of the shocked sample and a suite of diagnostics that characterize the radiation drive. Our near term goal is to use the spectral emission to obtain the temperature of the shocked material. Longer term objectives include the examination of deviations of the spectrum from blackbody, line emission from lower density regions, determination of kinetic processes in molecular systems, evaluation of phase transitions such as the onset of metalization in transparent materials, and characterization of the plasma formed when the shock exits the rear surface. An initial set of data illustrating both the potential and the challenge of these measurements is described.

  13. Environmental Measurements Laboratory fiscal year 1998: Accomplishments and technical activities

    SciTech Connect

    Erickson, M.D.

    1999-01-01

    The Environmental Measurements Laboratory (EML) is government-owned, government-operated, and programmatically under the DOE Office of Environmental Management. The Laboratory is administered by the Chicago Operations Office. EML provides program management, technical assistance and data quality assurance for measurements of radiation and radioactivity relating to environmental restoration, global nuclear nonproliferation, and other priority issues for the Department of Energy, as well as for other government, national, and international organizations. This report presents the technical activities and accomplishments of EML for Fiscal Year 1998.

  14. Review of measurement techniques for the neutron radiative-capture process

    SciTech Connect

    Poenitz, W.P.

    1981-07-01

    The experimental techniques applied in measurements of the neutron capture process are reviewed. The emphasis is on measurement techniques used in neutron capture cross section measurements. The activation technique applied mainly in earlier work has still its use in some cases, specifically for measurements of technologically important cross sections (/sup 238/U and /sup 232/Th) with high accuracy. Three major prompt neutron radioactive capture detection techniques have evolved: the total gamma radiation energy detection technique (mainly with large liquid scintillation detectors), the gamma-energy proportional detectors (with proportional counters or Moxon-Rae detectors), and the pulse-height weighting technique. These measurement techniques are generally applicable, however, shortcomings limit the achievable accuracy to a approx. = 5 to 15% uncertainty level.

  15. Estimation of Evapotranspiration as a function of Photosynthetic Active Radiation

    NASA Astrophysics Data System (ADS)

    Wesley, E.; Migliaccio, K.; Judge, J.

    2012-12-01

    The purpose of this research project is to more accurately measure the water balance and energy movements to properly allocate water resources at the Snapper Creek Site in Miami-Dade County, FL, by quantifying and estimating evapotranspiration (ET). ET is generally estimated using weather based equations, this project focused on estimating ET as a function of Photosynthetic Active Radiation (PAR). The project objectives were first to compose a function of PAR and calculated coefficients that can accurately estimate daily ET values with the least amount of variables used in its estimation equation, and second, to compare the newly identified ET estimation PAR function to TURC estimations, in comparison to our actual Eddy Covariance (EC) ET data and determine the differences in ET values. PAR, volumetric water content (VWC), and temperature (T) data were quality checked and used in developing singular and multiple variable regression models fit with SigmaPlot software. Fifteen different ET estimation equations were evaluated against EC ET and TURC estimated ET using R2 and slope factors. The selected equation that best estimated EC ET was cross validated using a 5 month data set; its daily and monthly ET values and sums were compared against the commonly used TURC equation. Using a multiple variable regression model, an equation with three variables (i.e., VWC, T, and PAR) was identified that best fit EC ET daily data. However, a regression was also found that used only PAR and provided ET predictions of similar accuracy. The PAR based regression model predicted daily EC ET more accurately than the traditional TURC method. Using only PAR to estimate ET reduces the input variables as compared to using the TURC model which requires T and solar radiation. Thus, not only is the PAR approach more accurate but also more cost effective. The PAR-based ET estimation equation derived in this study may be over fit considering only 5 months of data were used to produce the PAR

  16. Youth Physical Activity Resource Use and Activity Measured by Accelerometry

    ERIC Educational Resources Information Center

    Maslow, Andra L.; Colabianchi, Natalie

    2011-01-01

    Objectives: To examine whether use of physical activity resources (e.g., parks) was associated with daily physical activity measured by accelerometry. Methods: One hundred eleven adolescents completed a travel diary with concurrent accelerometry. The main exposure was self-reported use of a physical activity resource (none /1 resources). The main…

  17. Shuttle radiation dose measurements in the International Space Station orbits

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.

    2002-01-01

    The International Space Station (ISS) is now a reality with the start of a permanent human presence on board. Radiation presents a serious risk to the health and safety of the astronauts, and there is a clear requirement for estimating their exposures prior to and after flights. Predictions of the dose rate at times other than solar minimum or solar maximum have not been possible, because there has been no method to calculate the trapped-particle spectrum at intermediate times. Over the last few years, a tissue-equivalent proportional counter (TEPC) has been flown at a fixed mid-deck location on board the Space Shuttle in 51.65 degrees inclination flights. These flights have provided data that cover the expected changes in the dose rates due to changes in altitude and changes in solar activity from the solar minimum to the solar maximum of the current 23rd solar cycle. Based on these data, a simple function of the solar deceleration potential has been derived that can be used to predict the galactic cosmic radiation (GCR) dose rates to within +/-10%. For altitudes to be covered by the ISS, the dose rate due to the trapped particles is found to be a power-law function, rho(-2/3), of the atmospheric density, rho. This relationship can be used to predict trapped dose rates inside these spacecraft to +/-10% throughout the solar cycle. Thus, given the shielding distribution for a location inside the Space Shuttle or inside an ISS module, this approach can be used to predict the combined GCR + trapped dose rate to better than +/-15% for quiet solar conditions.

  18. Shuttle radiation dose measurements in the International Space Station orbits.

    PubMed

    Badhwar, Gautam D

    2002-01-01

    The International Space Station (ISS) is now a reality with the start of a permanent human presence on board. Radiation presents a serious risk to the health and safety of the astronauts, and there is a clear requirement for estimating their exposures prior to and after flights. Predictions of the dose rate at times other than solar minimum or solar maximum have not been possible, because there has been no method to calculate the trapped-particle spectrum at intermediate times. Over the last few years, a tissue-equivalent proportional counter (TEPC) has been flown at a fixed mid-deck location on board the Space Shuttle in 51.65 degrees inclination flights. These flights have provided data that cover the expected changes in the dose rates due to changes in altitude and changes in solar activity from the solar minimum to the solar maximum of the current 23rd solar cycle. Based on these data, a simple function of the solar deceleration potential has been derived that can be used to predict the galactic cosmic radiation (GCR) dose rates to within +/-10%. For altitudes to be covered by the ISS, the dose rate due to the trapped particles is found to be a power-law function, rho(-2/3), of the atmospheric density, rho. This relationship can be used to predict trapped dose rates inside these spacecraft to +/-10% throughout the solar cycle. Thus, given the shielding distribution for a location inside the Space Shuttle or inside an ISS module, this approach can be used to predict the combined GCR + trapped dose rate to better than +/-15% for quiet solar conditions.

  19. Environmental Radiation Measurements on MIR Station. Program 1; Internal Experiment

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.; Benton, E. R.

    1997-01-01

    Environmental radiation levels on the Russian space station Mir are being monitored under differing shielding conditions by a series of six area passive dosimeters (APDs) placed at individual locations inside the Core and Kvant 2 modules, and by an External Dosimeter Array (EDA) to be-deployed on the exterior surface of the Kvant 2 module. Each APD and the EDA contains CR-39 plastic nuclear track detectors (PNTDs) for measurement of LET spectra and TLDs for absorbed dose measurements. Two of the missions, NASA-2/Mir-21 and NASA-3/Mir-22 have been completed and the six APDs from each mission returned to Earth from Mir. This report covers progress to date on the analysis of TLDs and PNTDs from these two missions. For NASA-2/Mir-21, average mission absorbed dose rates varied from 271 to 407 micro-Gy/d at the APDS. For NASA-3/Mir-22, average mission absorbed dose rates varied from 265 to 421 micro-Gy/d.

  20. Absolute Measurements of Radiation Damage in Nanometer Thick Films

    PubMed Central

    Alizadeh, Elahe; Sanche, Léon

    2013-01-01

    We address the problem of absolute measurements of radiation damage in films of nanometer thicknesses. Thin films of DNA (~ 2–160nm) are deposited onto glass substrates and irradiated with varying doses of 1.5 keV X-rays under dry N2 at atmospheric pressure and room temperature. For each different thickness, the damage is assessed by measuring the loss of the supercoiled configuration as a function of incident photon fluence. From the exposure curves, the G-values are deduced, assuming that X-ray photons interacting with DNA, deposit all of their energy in the film. The results show that the G-value (i.e., damage per unit of deposited energy) increases with film thickness and reaches a plateau at 30±5 nm. This thickness dependence provides a correction factor to estimate the actual G-value for films with thicknesses below 30nm thickness. Thus, the absolute values of damage can be compared with that of films of any thickness under different experimental conditions. PMID:22562941

  1. Radiative transfer and radiative driving of outflows in active galactic nuclei and starbursts

    NASA Astrophysics Data System (ADS)

    Novak, G. S.; Ostriker, J. P.; Ciotti, L.

    2012-12-01

    To facilitate the study of black hole fuelling, star formation and feedback in galaxies, we outline a method for treating the radial forces on interstellar gas due to absorption of photons by dust grains. The method gives the correct behaviour in all of the relevant limits [dominated by the central point source; dominated by the distributed isotropic source; optically thin; optically thick to ultraviolet (UV)/optical; optically thick to infrared (IR)] and reasonably interpolates between the limits when necessary. The method is explicitly energy conserving so that UV/optical photons that are absorbed are not lost, but are rather redistributed to the IR where they may scatter out of the galaxy. We implement the radiative transfer algorithm in a two-dimensional hydrodynamical code designed to study feedback processes in the context of early-type galaxies. We find that the dynamics and final state of simulations are measurably but only moderately affected by radiative forces on dust, even when assumptions about the dust-to-gas ratio are varied from zero to a value appropriate for the Milky Way. In simulations with high gas densities designed to mimic ultraluminous IR galaxies with a star formation rate of several hundred solar masses per year, dust makes a more substantial contribution to the dynamics and outcome of the simulation. We find that, despite the large opacity of dust to UV radiation, the momentum input to the flow from radiation very rarely exceeds L/c due to two factors: the low opacity of dust to the re-radiated IR and the tendency for dust to be destroyed by sputtering in hot gas environments. We also develop a simplification of our radiative transfer algorithm that respects the essential physics but is much easier to implement and requires a fraction of the computational cost.

  2. Electron acceleration and radiation in evolving complex active regions

    NASA Astrophysics Data System (ADS)

    Anastasiadis, A.; Gontikakis, C.; Vilmer, N.; Vlahos, L.

    2004-07-01

    We present a model for the acceleration and radiation of solar energetic particles (electrons) in evolving complex active regions. The spatio - temporal evolution of active regions is calculated using a cellular automaton model, based on self-organized criticality. The acceleration of electrons is due to the presence of randomly placed, localized electric fields produced by the energy release process, simulated by the cellular automaton model. We calculate the resulting kinetic energy distributions of the particles and their emitted X-ray radiation spectra using the thick target approximation, and we perform a parametric study with respect to number of electric fields present and thermal temperature of the injected distribution. Finally, comparing our results with the existing observations, we find that they are in a good agreement with the observed X-ray spectra in the energy range 100-1000 keV.

  3. Active magnetic radiation shielding system analysis and key technologies.

    PubMed

    Washburn, S A; Blattnig, S R; Singleterry, R C; Westover, S C

    2015-01-01

    Many active magnetic shielding designs have been proposed in order to reduce the radiation exposure received by astronauts on long duration, deep space missions. While these designs are promising, they pose significant engineering challenges. This work presents a survey of the major systems required for such unconfined magnetic field design, allowing the identification of key technologies for future development. Basic mass calculations are developed for each system and are used to determine the resulting galactic cosmic radiation exposure for a generic solenoid design, using a range of magnetic field strength and thickness values, allowing some of the basic characteristics of such a design to be observed. This study focuses on a solenoid shaped, active magnetic shield design; however, many of the principles discussed are applicable regardless of the exact design configuration, particularly the key technologies cited. PMID:26177618

  4. Radiation inactivation analysis of influenza virus reveals different target sizes for fusion, leakage, and neuraminidase activities

    SciTech Connect

    Gibson, S.; Jung, C.Y.; Takahashi, M.; Lenard, J.

    1986-10-07

    The size of the functional units responsible for several activities carried out by the influenza virus envelope glycoproteins was determined by radiation inactivation analysis. Neuraminidase activity, which resides in the glycoprotein NA, was inactivated exponentially with an increasing radiation dose, yielding a target size of 94 +/- 5 kilodaltons (kDa), in reasonable agreement with that of the disulfide-bonded dimer (120 kDa). All the other activities studied are properties of the HA glycoprotein and were normalized to the known molecular weight of the neuraminidase dimer. Virus-induced fusion activity was measured by two phospholipid dilution assays: relief of energy transfer between N-(7-nitro-2,1,3-benzoxadiazol-4-yl)dipalmitoyl-L-alpha- phosphatidylethanolamine (N-NBD-PE) and N-(lissamine rhodamine B sulfonyl)-dioleoyl-L-alpha-phosphatidylethanolamine (N-Rh-PE) in target liposomes and relief of self-quenching of N-Rh-PE in target liposomes. Radiation inactivation of fusion activity proceeded exponentially with radiation dose, yielding normalized target sizes of 68 +/- 6 kDa by assay i and 70 +/- 4 kDa by assay ii. These values are close to the molecular weight of a single disulfide-bonded (HA1 + HA2) unit (75 kDa), the monomer of the HA trimer. A single monomer is thus inactivated by each radiation event, and each monomer (or some part of it) constitutes a minimal functional unit capable of mediating fusion. Virus-induced leakage of calcein from target liposomes and virus-induced leakage of hemoglobin from erythrocytes (hemolysis) both showed more complex inactivation behavior: a pronounced shoulder was present in both inactivation curves, followed by a steep drop in activity at higher radiation levels.

  5. Cerenkov radiation imaging as a method for quantitative measurements of beta particles in a microfluidic chip

    PubMed Central

    Cho, Jennifer S; Taschereau, Richard; Olma, Sebastian; Liu, Kan; Chen, Yi-Chun; Shen, Clifton K-F; van Dam, R Michael; Chatziioannou, Arion F.

    2009-01-01

    It has been observed that microfluidic chips used for synthesizing 18F-labeled compounds demonstrate visible light emission without nearby scintillators or fluorescent materials. The origin of the light was investigated and found to be consistent with the emission characteristics from Cerenkov radiation. Since 18F decays through the emission of high-energy positrons, the energy threshold for beta particles, i.e., electrons or positrons, to generate Cerenkov radiation was calculated for water and polydimethylsiloxane (PDMS), the most commonly used polymer-based material for microfluidic chips. Beta particles emitted from 18F have a continuous energy spectrum, with a maximum energy that exceeds this energy threshold for both water and PDMS. In addition, the spectral characteristics of the emitted light from 18F in distilled water were also measured, yielding a broad distribution from 300 nm to 700 nm, with higher intensity at shorter wavelengths. A photograph of the 18F solution showed a bluish-white light emitted from the solution, further suggesting Cerenkov radiation. In this study, the feasibility of using this Cerenkov light emission as a method for quantitative measurements of the radioactivity within the microfluidic chip in situ was evaluated. A detector previously developed for imaging microfluidic platforms was used. The detector consisted of a charge coupled device (CCD) optically coupled to a lens. The system spatial resolution, minimum detectable activity and dynamic range were evaluated. In addition, a calibration of Cerenkov signal versus activity concentration in the microfluidic chip was determined. This novel method of Cerenkov radiation measurements will provide researchers with a simple yet robust quantitative imaging tool for microfluidic applications utilizing beta particles. PMID:19847018

  6. Measurements of background gamma radiation on Spacelab 2

    NASA Technical Reports Server (NTRS)

    Fishman, G. J.; Paciesas, W. S.; Gregory, J. C.

    1987-01-01

    A nuclear radiation monitor (NRM) which was flown as part of the verification instrumentation on the Spacelab 2 mission (July 29 - August 6, 1985) recorded spectra every 20 seconds and counting rates in coarse energy bands on finer time scales. The gamma radiation environment on Spacelab is characterized by cosmic-ray and trapped proton secondary radiation in the Spacelab/Shuttle, earth albedo radiation, and delayed induced radioactivity in the detector and surrounding materials. It is found that passages through South Atlantic Anomaly protons produce a well-defined background enhancement.

  7. SYNCHROTRON RADIATION, FREE ELECTRON LASER, APPLICATION OF NUCLEAR TECHNOLOGY, ETC.: Measurement of radiation dose at the north interaction point of BEPC II

    NASA Astrophysics Data System (ADS)

    Mo, Xiao-Hu; Zhang, Jian-Yong; Zhang, Tian-Bao; Zhang, Qing-Jiang; Achasov, Mikhail; Fu, Cheng-Dong; Muchnoi, Nikolay; Qin, Qing; Qu, Hua-Min; Wang, Yi-Fang; Wu, Jing-Min; Xu, Jin-Qiang; Yu, Bo-Xiang

    2009-10-01

    The technique details for measuring radiation dose are expounded. The results of gamma and neutron radiation levels are presented and the corresponding radiation shielding is discussed based on the simplified estimation. In addition, the photon radiation level move as background for future experiments is measured by a NaI(Tl) detector.

  8. Measuring Homework Completion in Behavioral Activation

    ERIC Educational Resources Information Center

    Busch, Andrew M.; Uebelacker, Lisa A.; Kalibatseva, Zornitsa; Miller, Ivan W.

    2010-01-01

    The aim of this study was to develop and validate an observer-based coding system for the characterization and completion of homework assignments during Behavioral Activation (BA). Existing measures of homework completion are generally unsophisticated, and there is no current measure of homework completion designed to capture the particularities…

  9. Active cell mechanics: Measurement and theory.

    PubMed

    Ahmed, Wylie W; Fodor, Étienne; Betz, Timo

    2015-11-01

    Living cells are active mechanical systems that are able to generate forces. Their structure and shape are primarily determined by biopolymer filaments and molecular motors that form the cytoskeleton. Active force generation requires constant consumption of energy to maintain the nonequilibrium activity to drive organization and transport processes necessary for their function. To understand this activity it is necessary to develop new approaches to probe the underlying physical processes. Active cell mechanics incorporates active molecular-scale force generation into the traditional framework of mechanics of materials. This review highlights recent experimental and theoretical developments towards understanding active cell mechanics. We focus primarily on intracellular mechanical measurements and theoretical advances utilizing the Langevin framework. These developing approaches allow a quantitative understanding of nonequilibrium mechanical activity in living cells. This article is part of a Special Issue entitled: Mechanobiology.

  10. Cosmic radiation measurements on-board aircraft with the variance method.

    PubMed

    Kyllönen, J E; Lindborg, L; Samuelson, G

    2001-01-01

    The microdosimetric variance-covariance method has been used for cosmic radiation measurements on-board aircraft. Two independent methods of data analysis are presented; the first based on a high energy neutron calibration and the second on identification of single high LET events in the measured multiple event spectrum. Reduced dose levels at high geomagnetic latitudes are observed on one flight in a period of enhanced solar activity as indicated by a reduced ground-level neutron fluence rate. It is shown that with a reduced 137Cs-calibration factor, a Geiger-Mueller tube can be used as a low LET monitor, and that the wall thickness of a tissue-equivalent proportional counter is not crucial for flight measurements. No covariance is observed on any flight indicating it is sufficient to base dose determinations on variance measurements with only one detector. The uncertainties involved are also discussed in some detail.

  11. Measurement of radiation exposure of astronauts by radiochemical techniques

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.

    1972-01-01

    Only two of the fecal specimens collected inflight during the Apollo 15 mission were returned for analysis. Difficulty in obtaining reasonably accurate radiation dose estimates based on the cosmogenic radionuclide content of the specimens was encountered due to the limited sampling. The concentrations of Na-22, K-40, Cr-51, Fe-59, and Cs-137 are reported. The concentrations of 24 major, minor, and trace elements in these two specimens were determined. Most concentrations are typical of those observed previously. Major exceptions are extremely low values for selenium and extraordinarily high values for rare earth elements. The net Po-210 activities in the Apollo 11 and 12 Solar Wind Composition foils and in the Apollo 8 and 12 spacecraft reflective coatings due to lunar exposure have been determined. Equilibrium concentrations of 0.082 + or - 0.012 disintegrations /sq cm sec of Rn-222 in the lunar atmosphere and 0.0238 + or - 0.0035 disintegrations /sq cm sec of Po-210 on the lunar surface have been calculated for Oceanus Procellarum.

  12. CERES: The Next Generation of Earth Radiation Budget Measurements

    NASA Technical Reports Server (NTRS)

    Gibson, Gary G.; Wielicki, Bruce A.

    1999-01-01

    NASA's Earth Observing System (EOS) is part of an international program for studying the Earth from space using a multiple-instrument, multiple-satellite approach. The Clouds and the Earth's Radiant Energy System (CERES) experiment is designed to monitor changes in the Earth s radiant energy system and cloud systems and to provide these data with sufficient simultaneity and accuracy to examine critical cloud/climate feedback mechanisms which may play a major role in determining future changes in the climate system. The first EOS satellite (Terra), scheduled for launch this year, and the EOS-PM satellite, to be launched in late 2000, will each carry two CERES instruments. The first CERES instrument was launched in 1997 on the Tropical Rainfall Measuring Mission (TRMM) satellite. The CERES TRMM data show excellent instrument stability and a factor of 2 to 3 less error than previous Earth radiation budget missions. The first CERES data products have been validated and archived. The data consist of instantaneous longwave and shortwave broadband radiances, top-of-atmosphere fluxes, scene types, and time and space averaged fluxes and albedo. A later data product will combine CERES radiances and high- resolution imager data to produce cloud properties and fluxes throughout the atmosphere and at the surface.

  13. Measuring Radiation Patterns of Reconfigurable Patch Antennas on Wafers

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.

    2004-01-01

    An apparatus and technique have been devised for measuring the radiation pattern of a microwave patch antenna that is one of a number of identical units that have been fabricated in a planar array on a high-resistivity silicon wafer. The apparatus and technique are intended, more specifically, for application to such an antenna that includes a DC-controlled microelectromechanical system (MEMS) actuator for switching the antenna between two polarization states or between two resonance frequencies. Prior to the development of the present apparatus and technique, patch antennas on wafers were tested by techniques and equipment that are more suited to testing of conventional printed-circuit antennas. The techniques included sawing of the wafers to isolate individual antennas for testing. The equipment included custom-built test fixtures that included special signal launchers and transmission-line transitions. The present apparatus and technique eliminate the need for sawing wafers and for custom-built test fixtures, thereby making it possible to test antennas in less time and at less cost. Moreover, in a production setting, elimination of the premature sawing of wafers for testing reduces loss from breakage, thereby enhancing yield.

  14. Atmospheric Radiation Measurement Program facilities newsletter, November 2002.

    SciTech Connect

    Holdridge, D. J.

    2002-12-03

    Fall 2002 Intensive Operation Periods: Single Column Model and Unmanned Aerospace Vehicle--In an Intensive Operation Period (IOP) on November 3-23, 2002, researchers at the SGP CART site are collecting a detailed data set for use in improving the Single Column Model (SCM), a scaled-down climate model. The SCM represents one vertical column of air above Earth's surface and requires less computation time than a full-scale global climate model. Researchers first use the SCM to efficiently improve submodels of clouds, solar radiation transfer, and atmosphere-surface interactions, then implement the results in large-scale global models. With measured values for a starting point, the SCM predicts atmospheric variables during prescribed time periods. A computer calculates values for such quantities as the amount of solar radiation reaching the surface and predicts how clouds will evolve and interact with incoming light from the sun. Researchers compare the SCM's predictions with actual measurements made during the IOP, then adjust the submodels to make predictions more reliable. A second IOP conducted concurrently with the SCM IOP involves high-altitude, long-duration aircraft flights. The original plan was to use an unmanned aerospace vehicle (UAV), but the National Aeronautics and Space Administration (NASA) aircraft Proteus will be substituted because all UAVs have been deployed elsewhere. The UAV is a small, instrument-equipped, remote-control plane that is operated from the ground by a computer. The Proteus is a manned aircraft, originally designed to carry telecommunications relay equipment, that can be reconfigured for uses such as reconnaissance and surveillance, commercial imaging, launching of small space satellites, and atmospheric research. The plane is designed for two on-board pilots in a pressurized cabin, flying to altitudes up to 65,000 feet for as long as 18 hours. The Proteus has a variable wingspan of 77-92 feet and is 56 feet long. The plane can carry

  15. Atmospheric Radiation Measurement Program facilities newsletter, October 2000.

    SciTech Connect

    Sisterson, D. L.

    2000-11-09

    Energy Balance Bowen Ratio System--Estimates of surface energy fluxes are a primary product of the data collection systems at the ARM SGP CART site. Surface fluxes tell researchers a great deal about the effects of interactions between the sun's energy and Earth. Surface fluxes of latent and sensible heat can be estimated by measuring temperature and relative humidity gradients across a vertical distance. Sensible heat is what we feel coming from a warm sidewalk or a metal car door; it can be measured with a thermometer. Latent heat, on the other hand, is released or absorbed during transformations such as the freezing of water into ice or the evaporation of morning dew from a lawn. Such a transformation is referred to as a ''phase change,'' the conversion of a substance among its solid, liquid, and vapor phases. Phase change is an important aspect of our climate. Earth's water cycle abounds with phase changes: rain falls and evaporates, changing from liquid to vapor; the water vapor in the air condenses to form clouds, changing from a gas into a liquid cloud droplet, and eventually falls to Earth's surface as rain or snow; snow falls and melts to liquid or sublimes directly to water vapor. This cyclic process has no end. Surface vegetation and land use play extremely important roles in surface energy fluxes. Plants absorb and reflect solar radiation and also take up water and expel water vapor. The type of plant material, its stage of growth, and its color determine whether and to what extent the surface and air can couple and exchange energy.

  16. Effect of smoke on the transmissivity of photosynthetically active radiation inside the canopy

    NASA Astrophysics Data System (ADS)

    Yamasoe, M.; von Randow, C.; Manzi, A.; Schafer, J.; Eck, T.; Holben, B.

    2005-08-01

    Biomass burning activities emit high concentrations of aerosol particles to the atmosphere. Such particles can interact with solar radiation, decreasing the amount of light reaching the surface and increasing the fraction of diffuse radiation through scattering processes. This work reports results from photosynthetic active radiation (PAR) and aerosol optical depth (AOD) measurements conducted simultaneously at Reserva Biológica do Jaru (Rondonia State, Brazil) during LBA/SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia/ Smoke, Aerosols, Clouds, Rainfall, and Climate) and RaCCI (Radiation, Cloud, and Climate Interactions in the Amazon during the Dry-to-Wet Transition Season) field experiments from 15 September to 15 November 2002. AOD values were retrieved from an AERONET (Aerosol Robotic Network) radiometer, MODIS (Moderate Resolution Spectroradiometer) and a portable sunphotometer from the United States Department of Agriculture-Forest Service. Daily mean downward PAR irradiance at the top of canopy was reduced by up to 50% due to the smoke aerosol particles. This radiation reduction affected turbulent fluxes of sensible and latent heats at the surface, observed particularly for high values of aerosol optical depth. The increase of aerosol optical depth also enhanced the transmission of photosynthetic active radiation inside the canopy. This result was a consequence of enhanced availability of diffuse radiation due to light scattering by the aerosol particles. A complex relationship was identified between light availability inside the canopy and net ecosystem exchange (NEE). The results showed that the increase of aerosol optical depth corresponded to an increase on CO2 exchange, indicating more CO2 uptake by the vegetation. However, for a higher AOD value, the corresponding NEE was lower than for intermediate values. Further studies are needed to better understand these findings, which were reported for the first time for the Amazon region under

  17. Satellite Infrared Radiation Measurements Prior to the Major Earthquakes

    NASA Technical Reports Server (NTRS)

    Ouzounov, Dimitar; Pulintes, S.; Bryant, N.; Taylor, Patrick; Freund, F.

    2005-01-01

    This work describes our search for a relationship between tectonic stresses and increases in mid-infrared (IR) flux as part of a possible ensemble of electromagnetic (EM) phenomena that may be related to earthquake activity. We present and &scuss observed variations in thermal transients and radiation fields prior to the earthquakes of Jan 22, 2003 Colima (M6.7) Mexico, Sept. 28 .2004 near Parkfield (M6.0) in California and Northern Sumatra (M8.5) Dec. 26,2004. Previous analysis of earthquake events has indicated the presence of an IR anomaly, where temperatures increased or did not return to its usual nighttime value. Our procedures analyze nighttime satellite data that records the general condtion of the ground after sunset. We have found from the MODIS instrument data that five days before the Colima earthquake the IR land surface nighttime temperature rose up to +4 degrees C in a 100 km radius around the epicenter. The IR transient field recorded by MODIS in the vicinity of Parkfield, also with a cloud free environment, was around +1 degree C and is significantly smaller than the IR anomaly around the Colima epicenter. Ground surface temperatures near the Parkfield epicenter four days prior to the earthquake show steady increase. However, on the night preceding the quake, a significant drop in relative humidity was indicated, process similar to those register prior to the Colima event. Recent analyses of continuous ongoing long- wavelength Earth radiation (OLR) indicate significant and anomalous variability prior to some earthquakes. The cause of these anomalies is not well understood but could be the result of a triggering by an interaction between the lithosphere-hydrosphere and atmospheric related to changes in the near surface electrical field and/or gas composition prior to the earthquake. The OLR anomaly usually covers large areas surrounding the main epicenter. We have found strong anomalies signal (two sigma) along the epicentral area signals on Dec 21

  18. Measurements of the PLT and PDX device activation

    SciTech Connect

    Stavely, J.; Barnes, C.W.; Chrien, R.E.; Strachan, J.D.

    1981-09-01

    Measurements of the activation levels around the PLT and PDX tokamaks have been made using a Ge(Li) gamma spectrometer and a Geiger counter. The activation results from radiation induced in the plasma by 14 MeV neutrons from the d(t,n)..cap alpha.. fusion reaction, 14.7 MeV protons from the d(/sup 3/He,p)..cap alpha.. fusion reaction, 10 ..-->.. 20 MeV hard x-rays from runaway electron induced bremmstrahlung, and 2.5 MeV neutrons from the d(d,n)/sup 3/He fusion reaction. The magnitude of the activation is compared to that predicted for PDX on the basis of one-dimensional activation codes.

  19. Introduction to Radiation Issues for International Space Station Extravehicular Activities. Chapter 1

    NASA Technical Reports Server (NTRS)

    Shavers, M. R.; Saganti, P. B.; Miller, J.; Cucinotta, F. A.

    2003-01-01

    The International Space Station (ISS) provides significant challenges for radiation protection of the crew due to a combination of circumstances including: the extended duration of missions for many crewmembers, the exceptionally dynamic nature of the radiation environment in ISS orbit, and the necessity for numerous planned extravehicular activities (EVA) for station construction and maintenance. Radiation protection requires accurate radiation dose measurements and precise risk modeling of the transmission of high fluxes of energetic electrons and protons through the relatively thin shielding provided by the space suits worn during EVA. Experiments and analyses have been performed due to the necessity to assure complete radiation safety for the EVA crew and thereby ensure mission success. The detailed characterization described of the material and topological properties of the ISS space suits can be used as a basis for design of space suits used in future exploration missions. In radiation protection practices, risk from exposure to ionizing radiation is determined analytically by the level of exposure, the detrimental quality of the radiation field, the inherent radiosensitivity of the tissues or organs irradiated, and the age and gender of the person at the time of exposure. During low Earth orbit (LEO) EVA, the relatively high fluxes of low-energy electrons and protons lead to large variations in exposure of the skin, lens of the eye, and tissues in other shallow anatomical locations. The technical papers in this publication describe a number of ground-based experiments that precisely measure the thickness of the NASA extravehicular mobility unit (EMU) and Russian Zvezda Orlan-M suits using medical computerized tomography (CT) X-ray analysis, and particle accelerator experiments that measure the minimum kinetic energy required by electrons and photons to penetrate major components of the suits. These studies provide information necessary for improving the

  20. Neutron Measurements for Radiation Protection in Low Earth Orbit - History and Future

    NASA Technical Reports Server (NTRS)

    Golightly, M. J.; Se,pmes. E/

    2003-01-01

    The neutron environment inside spacecraft has been of interest from a scientific and radiation protection perspective since early in the history of manned spaceflight. With 1:.1e exception of a few missions which carried plutonium-fueled radioisotope thermoelectric generators, all of the neutrons inside the spacecraft are secondary radiations resulting from interactions of high-energy charged particles with nuclei in the Earth's atmosphere, spacecraft structural materials, and the astronaut's own bodies. Although of great interest, definitive measurements of the spacecraft neutron field have been difficult due to the wide particle energy range and the limited available volume and power for traditional techniques involving Bonner spheres. A multitude of measurements, however, have been made of the neutron environment inside spacecraft. The majority of measurements were made using passive techniques including metal activation fo ils, fission foils, nuclear photoemulsions, plastic track detectors, and thermoluminescent detectors. Active measurements have utilized proton recoil spectrometers (stilbene), Bonner Spheres eRe proportional counter based), and LiI(Eu)phoswich scintillation detectors. For the International Space Station (ISS), only the plastic track! thermoluminescent detectors are used with any regularity. A monitoring program utilizing a set of active Bonner spheres was carried out in the ISS Lab module from March - December 200l. These measurements provide a very limited look at the crew neutron exposure, both in time coverage and neutron energy coverage. A review of the currently published data from past flights will be made and compared with the more recent results from the ISS. Future measurement efforts using currently available techniques and those in development will be also discussed.

  1. Quantitative measurement of radiation pressure on a microcantilever in ambient environment

    SciTech Connect

    Ma, Dakang; Munday, Jeremy N.; Garrett, Joseph L.

    2015-03-02

    Light reflected off a material or absorbed within it exerts radiation pressure through the transfer of momentum. Micro/nano-mechanical transducers have become sensitive enough that radiation pressure can influence these systems. However, photothermal effects often accompany and overwhelm the radiation pressure, complicating its measurement. In this letter, we investigate the radiation force on an uncoated silicon nitride microcantilever in ambient conditions. We identify and separate the radiation pressure and photothermal forces through an analysis of the cantilever's frequency response. Further, by working in a regime where radiation pressure is dominant, we are able to accurately measure the radiation pressure. Experimental results are compared to theory and found to agree within the measured and calculated uncertainties.

  2. Atmospheric Radiation Measurement (ARM) Data from the ARM Specific Measurement Categories

    DOE Data Explorer

    The ARM Program gathers a wide variety of measurements from many different sources. Each day, the Data Archive stores and distributes large quantities of data collected from these sources. Scientists then use these data to research atmospheric radiation balance and cloud feedback processes, which are critical elements of global climate change. The huge archive of ARM data can be organized by measurement categories into six "collections:" Aerosols, Atmospheric Carbon, Atmospheric State, Cloud Properties, Radiometric, and Surface Properties. Clicking on one of the measurement categories leads to a page that breaks that category down into sub-categories. For example, "Aerosols" is broken down into Microphysical and Chemical Properties (with 9 subsets) and Optical and Radiative Properties (with 7 subsets). Each of the subset links, in turn, leads to detailed information pages and links to specific data streams. Users will be requested to create a password, but the data files are free for viewing and downloading. The ARM Archive physically resides at the Oak Ridge National Laboratory.

  3. Lauriston S. Taylor Lecture on radiation protection and measurements: what makes particle radiation so effective?

    PubMed

    Blakely, Eleanor A

    2012-11-01

    The scientific basis for the physical and biological effectiveness of particle radiations has emerged from many decades of meticulous basic research. A diverse array of biologically relevant consequences at the molecular, cellular, tissue, and organism level have been reported, but what are the key processes and mechanisms that make particle radiation so effective, and what competing processes define dose dependences? Recent studies have shown that individual genotypes control radiation-regulated genes and pathways in response to radiations of varying ionization density. The fact that densely ionizing radiations can affect different gene families than sparsely ionizing radiations, and that the effects are dose- and time-dependent, has opened up new areas of future research. The complex microenvironment of the stroma and the significant contributions of the immune response have added to our understanding of tissue-specific differences across the linear energy transfer (LET) spectrum. The importance of targeted versus nontargeted effects remains a thorny but elusive and important contributor to chronic low dose radiation effects of variable LET that still needs further research. The induction of cancer is also LET-dependent, suggesting different mechanisms of action across the gradient of ionization density. The focus of this 35th Lauriston S. Taylor Lecture is to chronicle the step-by-step acquisition of experimental clues that have refined our understanding of what makes particle radiation so effective, with emphasis on the example of radiation effects on the crystalline lens of the human eye.

  4. LAURISTON S. TAYLOR LECTURE ON RADIATION PROTECTION AND MEASURMENTS: WHAT MAKES PARTICLE RADIATION SO EFFECTIVE?

    PubMed Central

    Blakely, Eleanor A.

    2012-01-01

    The scientific basis for the physical and biological effectiveness of particle radiations has emerged from many decades of meticulous basic research. A diverse array of biologically relevant consequences at the molecular, cellular, tissue, and organism level have been reported, but what are the key processes and mechanisms that make particle radiation so effective, and what competing processes define dose dependences? Recent studies have shown that individual genotypes control radiation-regulated genes and pathways in response to radiations of varying ionization density. The fact that densely ionizing radiations can affect different gene families than sparsely ionizing radiations, and that the effects are dose- and time-dependent has opened up new areas of future research. The complex microenvironment of the stroma, and the significant contributions of the immune response have added to our understanding of tissue-specific differences across the linear energy transfer (LET) spectrum. The importance of targeted vs. nontargeted effects remain a thorny, but elusive and important contributor to chronic low dose radiation effects of variable LET that still needs further research. The induction of cancer is also LET-dependent, suggesting different mechanisms of action across the gradient of ionization density. The focus of this 35th Lauriston S. Taylor Lecture is to chronicle the step-by-step acquisition of experimental clues that have refined our understanding of what makes particle radiation so effective, with emphasis on the example of radiation effects on the crystalline lens of the human eye. PMID:23032880

  5. The Measurement of Spectral Characteristics and Composition of Radiation in Atlas with MEDIPIX2-USB Devices

    NASA Astrophysics Data System (ADS)

    Campbell, M.; Doležal, Z.; Greiffenberg, D.; Heijne, E.; Holy, T.; Idárraga, J.; Jakůbek, J.; Král, V.; Králík, M.; Lebel, C.; Leroy, C.; Llopart, X.; Lord, G.; Maneuski, D.; Ouellette, O.; Sochor, V.; Pospíšil, S.; Suk, M.; Tlustos, L.; Vykydal, Z.; Wilhelm, I.

    2008-06-01

    A network of devices to perform real-time measurements of the spectral characteristics and composition of radiation in the ATLAS detector and cavern during its operation is being built. This system of detectors will be a stand alone system fully capable of delivering real-time images of fluxes and spectral composition of different particle species including slow and fast neutrons. The devices are based on MEDIPIX2 pixel silicon detectors that will be operated via active USB cables and USB-Ethernet extenders through an Ethernet network by a PC located in the USA15 ATLAS control room. The installation of 14 devices inside ATLAS (detector and cavern) is in progress.

  6. Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization.

    PubMed

    Meng, Zhen; Gan, Ye-Hua

    2015-05-01

    Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation.

  7. The Atmospheric Radiation Measurement Program May 2003 Intensive Operations Period Examining Aerosol Properties and Radiative Influences: Preface to Special Section

    NASA Technical Reports Server (NTRS)

    Ferrare, Richard; Feingold, Graham; Ghan, Steven; Ogren, John; Schmid, Beat; Schwartz, Stephen E.; Sheridan, Pat

    2006-01-01

    Atmospheric aerosols influence climate by scattering and absorbing radiation in clear air (direct effects) and by serving as cloud condensation nuclei, modifying the microphysical properties of clouds, influencing radiation and precipitation development (indirect effects). Much of present uncertainty in forcing of climate change is due to uncertainty in the relations between aerosol microphysical and optical properties and their radiative influences (direct effects) and between microphysical properties and their ability to serve as cloud condensation nuclei at given supersaturations (indirect effects). This paper introduces a special section that reports on a field campaign conducted at the Department of Energy Atmospheric Radiation Measurement site in North Central Oklahoma in May, 2003, examining these relations using in situ airborne measurements and surface-, airborne-, and space-based remote sensing.

  8. Measurements of secondary neutrons from cosmic radiation with a Bonner sphere spectrometer at 79 degrees N.

    PubMed

    Rühm, Werner; Mares, V; Pioch, C; Weitzenegger, E; Vockenroth, R; Paretzke, H G

    2009-04-01

    Air crew members and airline passengers are continuously exposed to cosmic radiation during their flights. Particles ejected by the sun during so-called solar particle events (SPEs) in periods of high solar activity can contribute to this exposure. In rare cases the dose from a single SPE might even exceed the annual dose limit of 1 mSv above which dose monitoring of air crews is legally required in Germany. Measurements performed by means of neutron monitors have already shown that the relative intensity of secondary neutrons from cosmic radiation is enhanced during an SPE, particularly at regions close to the magnetic poles of the Earth where shielding of the cosmic radiation by the geomagnetic field is low. Here we describe a Bonner sphere spectrometer installed at the Koldewey station at 79 degrees N, i.e. about 1,000 km from the geographic North pole, which is designed to provide first experimental data on the time-dependent energy spectrum of neutrons produced in the atmosphere during an SPE. This will be important to calculate doses from these neutrons to air crew members. The system is described in detail and first results are shown that were obtained during quiet periods of sun activity.

  9. Measuring the Built Environment for Physical Activity

    PubMed Central

    Brownson, Ross C.; Hoehner, Christine M.; Day, Kristen; Forsyth, Ann; Sallis, James F.

    2009-01-01

    Physical inactivity is one of the most important public health issues in the U.S. and internationally. Increasingly, links are being identified between various elements of the physical—or built—environment and physical activity. To understand the impact of the built environment on physical activity, the development of high-quality measures is essential. Three categories of built environment data are being used: (1) perceived measures obtained by telephone interview or self-administered questionnaires; (2) observational measures obtained using systematic observational methods (audits); and (3) archival data sets that are often layered and analyzed with GIS. This review provides a critical assessment of these three types of built-environment measures relevant to the study of physical activity. Among perceived measures, 19 questionnaires were reviewed, ranging in length from 7 to 68 questions. Twenty audit tools were reviewed that cover community environments (i.e., neighborhoods, cities), parks, and trails. For GIS-derived measures, more than 50 studies were reviewed. A large degree of variability was found in the operationalization of common GIS measures, which include population density, land-use mix, access to recreational facilities, and street pattern. This first comprehensive examination of built-environment measures demonstrates considerable progress over the past decade, showing diverse environmental variables available that use multiple modes of assessment. Most can be considered first-generation measures, so further development is needed. In particular, further research is needed to improve the technical quality of measures, understand the relevance to various population groups, and understand the utility of measures for science and public health. PMID:19285216

  10. Measuring Solar Radiation Incident on Earth: Solar Constant-3 (SOLCON-3)

    NASA Technical Reports Server (NTRS)

    Crommelynck, Dominique; Joukoff, Alexandre; Dewitte, Steven

    2002-01-01

    Life on Earth is possible because the climate conditions on Earth are relatively mild. One element of the climate on Earth, the temperature, is determined by the heat exchanges between the Earth and its surroundings, outer space. The heat exchanges take place in the form of electromagnetic radiation. The Earth gains energy because it absorbs solar radiation, and it loses energy because it emits thermal infrared radiation to cold space. The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. When the balance is perturbed, a temperature change and hence a climate change of the Earth will occur. One possible perturbation of the balance is the CO2 greenhouse effect: when the amount of CO2 in the atmosphere increases, this will reduce the loss of thermal infrared radiation to cold space. Earth will gain more heat and hence the temperature will rise. Another perturbation of the balance can occur through variation of the amount of energy emitted by the sun. When the sun emits more energy, this will directly cause a rise of temperature on Earth. For a long time scientists believed that the energy emitted by the sun was constant. The 'solar constant' is defined as the amount of solar energy received per unit surface at a distance of one astronomical unit (the average distance of Earth's orbit) from the sun. Accurate measurements of the variations of the solar constant have been made since 1978. From these we know that the solar constant varies approximately with the 11-year solar cycle observed in other solar phenomena, such as the occurrence of sunspots, dark spots that are sometimes visible on the solar surface. When a sunspot occurs on the sun, since the spot is dark, the radiation (light) emitted by the sun drops instantaneously. Oddly, periods of high solar activity, when a lot of sunspot numbers increase, correspond to periods when the average solar constant is high. This indicates that

  11. Atmospheric Radiation Measurement Program facilities newsletter, October 2002.

    SciTech Connect

    Holdridge, D. J.

    2002-11-04

    Aerosol Observing System Upgraded--The Aerosol Observing System (AOS) at the SGP central facility recently received maintenance and was upgraded to improve its performance. The AOS measures the properties of the aerosol particles around it. Several AOS components were removed, repaired, and calibrated to operate within specifications. The system continuously gathers information about the way minute aerosol particles interact with solar radiation. A better understanding of these interactions will help climate change researchers integrate aerosol effects more accurately into global climate computer models. Polar Bears Make Work Dangerous at ARM North Slope of Alaska Site--The late development of seasonal sea ice has increased polar bear sitings at ARM's Barrow site. The bears were recently seen next to the ARM instrument towers at Barrow, making the normal work day a bit more tricky for the technicians who are at the site year-round. Polar bears are not afraid of people and will attack and kill. The bears usually spend most of their time on off-shore ice floes hunting seals. This season, a large storm pushed the floes out to sea while the bears were ashore at Barrow, leaving them to forage for food on land until the sea ice reforms with the onset of colder weather. The hungry bears have made working at the Barrow CART site a dangerous proposition. ARM workers carry shotguns with them at all times for protection. On a recent journey to the site, ARM instrument mentor Michael Ritsche encountered the animals. ''You become much more aware of your surroundings,'' said Ritsche after returning safely to Argonne. Barrow residents protect themselves by shooting warning shells to scare the bears away from developed areas. Hearing the firing in the early mornings and late evenings at Barrow reminded Ritsche that he was in a more dangerous world.

  12. Radiation profiles through the atmosphere measured by an auto controlled glider aircraft

    NASA Astrophysics Data System (ADS)

    Kräuchi, Andreas; Philipona, Rolf

    2014-05-01

    In 2011 radiation measurements through the atmosphere were made with a balloon borne short- and longwave net radiometer. These measurements were very promising and therefore new and improved sensors from Kipp&Zonen were used to equip a glider aircraft together with the standard Swiss radiosonde from Meteolabor AG. The glider serves as returning platform for the expensive and well calibrated radiation sensors. Double balloon technique is used to prevent pendulum motion during the ascent and to keep the radiation instruments as horizontal as possible. The built-in autopilot allows to return the gliderradiosonde to the launch site or to land it on predefined open space, which makes recovery much easier. The new return gliderradiosonde technique as well as new measurement possibilities will be shown. First measurements show radiation profiles through the atmosphere during different cloud conditions. Radiation profiles during different daytimes show the temporal resolution of vertical radiation profiles trough the atmosphere.

  13. An Automated System for Measuring Microphysical and Radiative Cloud Characteristics from a Tethered Balloon

    SciTech Connect

    Dr. Paul Lawson

    2004-03-15

    sensor package slowly descends to the ground and a radio tracking beacon is activated to locate the balloon and sensor package. The tethered balloon system was deployed in upslope clouds at the Smokey Hills Bombing Range in western Kansas and at Ft. Carson Air Force Base near Colorado Springs, Colorado. Both of these areas are FAA Restricted Airspace up to FL180 (18,000 ft MSL) so that the tethered balloon could be flown to its maximum height without violating FAA regulations. Because the feasibility field programs took place at the very end of the research period covered by this DOE grant, a detailed analysis of the results are beyond the scope of this report. However, examples of water drops and ice crystals recorded by the CPI demonstrated the feasibility of the balloon and sensor package. Based on our initial analysis of results from the feasibility field deployments, we have determined that the tethered balloon system is capable of making long -term measurements of meteorological, microphysical and radiation properties of polar stratus clouds up to a height of about 2 km. However, further field trials should be conducted before deploying the system in a full-up field campaign.

  14. Radiation Protection in Educational Institutions. Recommendations of the National Council on Radiation Protection and Measurements.

    ERIC Educational Resources Information Center

    National Council on Radiation Protection and Measurements, Washington, DC.

    The problems involved when radiation-producing devices of our contemporary technology are used in the teaching of science at the high school and undergraduate college level are discussed. Information is provided on the hazards involved in the use of radiation-producing equipment or radioactive materials in science demonstrations and experiments…

  15. New measurements for hadrontherapy and space radiation: biology

    NASA Technical Reports Server (NTRS)

    Blakely, E. A.

    2001-01-01

    The dual goals of optimizing clinical efficacy of hadrontherapy and determining radiation risk estimates for space research have intersected to a common focus for investigation of the biological effects of charged particles. This paper briefly highlights recent international progress at accelerator facilities engaged in both biological and clinical studies of the effects of particle beams, primarily protons, carbon and iron ions. Basic mechanisms of molecular, cellular and tissue responses continue under investigation for radiations with a range of ionization densities. Late normal tissue effects, including the risk of cancer in particular, are of importance for both research fields. International cooperation has enhanced the rate of progress as evidenced by recent publications. Specific areas of biomedical research related to the biological radiotoxicity of critical organs (especially the central nervous system), individual radiosensitivities to radiation carcinogenesis, and the analysis of effects in mixed radiation fields still require more research. Recommendations for addressing these issues are made.

  16. Measurement of the wall radiation in soft x-ray region in PDX (abstract)

    SciTech Connect

    Sesnic, S.; Tenney, F.H.; Bitter, M.; Hill, K.W.; von Goeler, S.

    1985-05-01

    A detector setup with three LN-cooled Si(Li) diodes is used to measure soft x-ray spectra (0.8--20 keV) emitted from the inside walls of the PDX vessel during the plasma discharge. The setup is part of a pulse-height-analysis system, which is used to measure the plasma and wall radiation simultaneously at five different radial positions. The wall and the plasma radiation are measured under different plasma conditions (e.g., OH and neutral beam heating). The wall radiation is very much increased during the neutral beam heating, with an enhancement factor of at least 10 over the OH wall radiation. Since we measure the plasma and the wall radiation at the same time, the measurements allow the conclusion that the wall radiation can be attributed essentially to fluorescence (line radiation, e.g., Ti-K/sub ..cap alpha../) and scattering (continuum part of the wall radiation spectrum). The fluorescence and the scattering are both caused by soft x-ray radiation flux coming from the plasma. There seems to be no need to invoke other, more exotic causes for the wall radiation, for example, charge particle bombardment of the wall.

  17. Measurement of the wall radiation in soft x-ray region in PDX

    SciTech Connect

    Sesnic, S.; Tenney, F.H.; Bitter, M.; Hill, K.W.; von Goeler, S.

    1985-06-01

    A detector setup with three LN-cooled Si(Li) diodes is used to measure soft x-ray spectra (0.8--20 keV) emitted from the inside walls of the PDX vessel during the plasma discharge. The setup is part of a pulse-height-analysis system, which is used to measure the plasma and wall radiation simultaneously at five different radial positions. The wall and the plasma radiation are measured under different plasma conditions (e.g., OH and neutral beam heating). The wall radiation is very much increased during the neutral beam heating, with an enhancement factor of at least 10 over the OH wall radiation. Since we measure the plasma and the wall radiation at the same time, the measurements allow the conclusion that the wall radiation can be attributed essentially to fluorescence (line radiation, e.g., Ti-K/sub ..cap alpha../) and scattering (continuum part of the wall radiation spectrum). The fluorescence and the scattering are both caused by soft x-ray radiation flux coming from the plasma. There seems to be no need to invoke other, more exotic causes for the wall radiation, for example, charge particle bombardment of the wall.

  18. Measurement of the wall radiation in soft x-ray region in PDX

    NASA Astrophysics Data System (ADS)

    Sesnic, S.; Tenney, F. H.; Bitter, M.; Hill, K. W.; von Goeler, S.

    1985-06-01

    A detector setup with three LN-cooled Si(Li) diodes is used to measure soft x-ray spectra (0.8-20 keV) emitted from the inside walls of the PDX vessel during the plasma discharge. The setup is part of a pulse-height-analysis system, which is used to measure the plasma and wall radiation simultaneously at five different radial positions. The wall and the plasma radiation are measured under different plasma conditions (e.g., OH and neutral beam heating). The wall radiation is very much increased during the neutral beam heating, with an enhancement factor of at least 10 over the OH wall radiation. Since we measure the plasma and the wall radiation at the same time, the measurements allow the conclusion that the wall radiation can be attributed essentially to fluorescence (line radiation, e.g., Ti-Kα) and scattering (continuum part of the wall radiation spectrum). The fluorescence and the scattering are both caused by soft x-ray radiation flux coming from the plasma. There seems to be no need to invoke other, more exotic causes for the wall radiation, for example, charge particle bombardment of the wall.

  19. Measurement of wall radiation in the soft x-ray region of PDX

    SciTech Connect

    Sesnic, S.; Tenney, F.H.; Bitter, M.; Hill, K.W.; von Goeler, S.

    1985-01-01

    A detector setup with three LN-cooled Si(Li) diodes is used to measure soft x-ray spectra (0.8 to 20 keV) emitted from the inside walls of the PDX vessel during the plasma discharge. This setup is part of a pulse-height-analysis system, which is used to measure the plasma and wall radiation simultaneously at five different radial positions. The wall and the plasma radiation are measured under different plasma conditions (e.g., OH and neutral beam heating). The wall radiation is increased very much during the neutral beam heating with an enhancement factor of at least 10 over OH wall radiation. Since we measure the plasma and the wall radiation at the same time, these measurements allow the conclusion that the wall radiation can be attributed essentially to fluorescence (line radiation, e.g., Ti-K/sub ..cap alpha../) and scattering (continuum part of the wall radiation spectrum). The fluorescence and the scattering are both caused by soft x-ray radiation flux coming from the plasma. There seems to be no need to invoke other, more exotic causes for the wall radiation (like charge particle bombardment of the wall).

  20. NASA Crew Personal Active Dosimeters (CPADs): Leveraging Novel Terrestrial Personal Radiation Monitoring Capabilities for Space Exploration

    NASA Technical Reports Server (NTRS)

    Leitgab, Martin; Semones, Edward; Lee, Kerry

    2016-01-01

    The NASA Space Radiation Analysis Group (SRAG) is developing novel Crew Personal Active Dosimeters (CAPDs) for upcoming crewed space exploration missions and beyond. To reduce the resource footprint of the project a COTS dosimeter base is used for the development of CPADs. This base was identified from evaluations of existing COTS personal dosimeters against the concept of operations of future crewed missions and tests against detection requirements for radiation characteristic of the space environment. CPADs exploit operations efficiencies from novel features for space flight personal dosimeters such as real-time dose feedback, and autonomous measuring and data transmission capabilities. Preliminary CPAD design, results of radiation testing and aspects of operational integration will be presented.

  1. Radiation Measured with Different Dosimeters for ISS-Expedition 18-19/ULF2 on Board International Space Station during Solar Minimum

    NASA Astrophysics Data System (ADS)

    Zhou, Dazhuang

    Radiation field of particles in low Earth orbit (LEO) is mainly composed of galactic cosmic rays (GCR), solar energetic particles and particles in SAA (South Atlantic Anomaly). GCR are modulated by solar activity, at the period of solar minimum activity, GCR intensity is at maximum and the main contributor for space radiation is GCR. At present for space radiation measurements conducted by JSC (Johnson Space Center) -SRAG (Space Radiation Analysis Group), the preferred active dosimeter sensitive to all LET (Linear Energy Transfer) is the tissue equivalent proportional counter (TEPC); the preferred passive dosimeters are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) sensitive to low LET as well as CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. For the method using passive dosimeters, radiation quantities for all LET can be obtained by combining radiation results measured with TLDs/OSLDs and CR-39 PNTDs. TEPC, TLDs/OSLDs and CR-39 detectors were used to measure the radiation field for the ISS (International Space Station) -Expedition 18-19/ULF2 space mission which was conducted from 15 November 2008 to 31 July 2009 -near the period of the recent solar minimum activity. LET spectra (differential and integral fluence, absorbed dose and dose equivalent) and radiation quantities were measured for positions TEPC, TESS (Temporary Sleeping Station, inside the polyethylene lined sleep station), SM-P 327 and 442 (Service Module -Panel 327 and 442). This paper presents radiation LET spectra measured with TEPC and CR-39 PNTDs and radiation dose measured with TLDs/OSLDs as well as the radiation quantities combined from results measured with passive dosimeters.

  2. Radiation Measured with Different Dosimeters for ISS-Expedition 18-19/ULF2 on Board International Space Station during Solar Minimum

    NASA Technical Reports Server (NTRS)

    Zhou, Dazhuang; Gaza, R.; Roed, Y.; Semones, E.; Lee, K.; Steenburgh, R.; Johnson, S.; Flanders, J.; Zapp, N.

    2010-01-01

    Radiation field of particles in low Earth orbit (LEO) is mainly composed of galactic cosmic rays (GCR), solar energetic particles and particles in SAA (South Atlantic Anomaly). GCR are modulated by solar activity, at the period of solar minimum activity, GCR intensity is at maximum and the main contributor for space radiation is GCR. At present for space radiation measurements conducted by JSC (Johnson Space Center) SRAG (Space Radiation Analysis Group), the preferred active dosimeter sensitive to all LET (Linear Energy Transfer) is the tissue equivalent proportional counter (TEPC); the preferred passive dosimeters are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) sensitive to low LET as well as CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. For the method using passive dosimeters, radiation quantities for all LET can be obtained by combining radiation results measured with TLDs/OSLDs and CR-39 PNTDs. TEPC, TLDs/OSLDs and CR-39 detectors were used to measure the radiation field for the ISS (International Space Station) - Expedition 18-19/ULF2 space mission which was conducted from 15 November 2008 to 31 July 2009 - near the period of the recent solar minimum activity. LET spectra (differential and integral fluence, absorbed dose and dose equivalent) and radiation quantities were measured for positions TEPC, TESS (Temporary Sleeping Station, inside the polyethylene lined sleep station), SM-P 327 and 442 (Service Module - Panel 327 and 442). This paper presents radiation LET spectra measured with TEPC and CR-39 PNTDs and radiation dose measured with TLDs/OSLDs as well as the radiation quantities combined from results measured with passive dosimeters.

  3. Stanford Synchrotron Radiation Laboratory activity report for 1987

    SciTech Connect

    Robinson, S.; Cantwell, K.

    1988-12-31

    During 1987, SSRL achieved many significant advances and reached several major milestones utilizing both SPEAR and PEP as synchrotron radiation sources as described in this report. Perhaps the following two are worthy of particular mention: (1) SPEAR reached an all time high of 4,190 delivered user-shifts during calendar year 1987, highlights of the many scientific results are given; (2) during a 12 day run in December of 1987, PEP was operated in a low emittance mode (calculated emittance 6.4 nanometer-radians) at 7.1 GeV with currents up to 33 mA. A second undulator beam line on PEP was commissioned during this run and used to record many spectra showing the extremely high brightness of the radiation. PEP is now by far the highest brightness synchrotron radiation source in the world. The report is divided into the following sections: (1) laboratory operations; (2) accelerator physics programs; (3) experimental facilities; (4) engineering division; (5) conferences and workshops; (6) SSRL organization; (7) experimental progress reports; (8) active proposals; (9) SSRL experiments and proposals by institution; and (10) SSRL publications.

  4. HEA-PVA gel system for UVA radiation dose measurement.

    PubMed

    Zhang, Wei; Yang, Liming; Fang, Sijia; Chen, Jie

    2016-10-01

    Acrylic monomer is known to be sensitive to ultraviolet radiation (UVR) through photoinitiator. Upon irradiation, the acrylic monomers formed stable polymer through free radical polymerization, hence its appearance will change from colorless and transparent to colored and non-transparent. Furthermore, the degree of changes was based on the UVR dose, and those optical changes could be detected by UV-vis spectrophotometer at the fixed wavelength of 550nm. In this study, we used 2-hydroxyethyl acrylate (HEA) as acrylic monomer, which mixed with polyvinyl alcohol (PVA), and finally obtained a three-dimensional hydrogel material through cross-linking by glutaraldehyde (GA). After doping with photoinitiator-Bis(2,6-difluoro-3-(1-hydropyrro-1-yl)-phenyl) titanocene (784), the gel material was sensitive to UV-A radiation (400-315nm), which forms an important part (~97%) of the natural solar UV radiation reaching the earth surface. The behavior of different formulations' dose response sensitivity, detector linearity, diffusion, stability after UVA radiation were investigated. The results showed that when the dosage range of UVA radiation was 0-560J/cm(2), the gel had a great sensitivity and the linearity was found to be closed to 1. After UVA radiation, the gel also had a very good optical stability. In addition to this, when irradiated with high dose UVA, the gel could maintain a low diffusion. PMID:27543762

  5. [Active radiation telethermometry in the complex diagnosis of ovarian tumors].

    PubMed

    Hozhenko, A I; Peresun'ko, O P; Orenchuk, V S; Vysochyna, K V

    1999-07-01

    An active remote radiation thermometry was used in the diagnosis and differential diagnosis of ovarian tumours by determining the heat flow from the area of projection of the ovaries and control background. Overall fourty three patients with ovarian tumours were examined by this method. Significance of the results secured was verified during the histological technique-aided operation. The authors have come to the conclusion that remote thermometry involving loading tests is a simple supplementary method of investigation that is helpful in diagnosing of both benign and malignant ovarian tumours.

  6. Absorbed photosynthetically active radiation of steppe vegetation and sun-view geometry effects on APAR estimates

    NASA Technical Reports Server (NTRS)

    Walter-Shea, E. A.; Blad, B. L.; Mesarch, M. A.; Hays, C. J.; Deering, D. W.; Eck, T. F.

    1992-01-01

    Instantaneous fractions of absorbed photosynthetically active radiation (APAR) were measured at the Streletskaya Steppe Reserve in conjunction with canopy bidirectional-reflected radiation measured at solar zenith angles ranging between 37 and 74 deg during the Kursk experiment (KUREX-91). APAR values were higher for KUREX-91 than those for the first ISLSCP field experiment (FIFE-89) and the amount of APAR of a canopy was a function of solar zenith angle, decreasing as solar zenith angle increased at the resrve. Differences in absorption are attributed to leaf area index (LAI) and leaf angle distribution and subsequently transmitted radiation interactions. LAIs were considerably higher at the reserve than those at the FIFE site. Leaf angle distributions of the reserve approach a uniform distribution while distributions at the FIFE site more closely approximate erectophile distributions. Reflected photosynthetically active radiation (PAR) components at KUREX-91 and FIFE-89 were similar in magnitude and in their response to solar zenith angle. Transmitted PAR increased with increasing solar zenith angle at KUREX-91 and decreased with increasing solar zenith angle at FIFE-89. Transmitted PAR at FIFE-89 was considerably larger than those at KUREX-91.

  7. Measurements of Neutron Radiation on the International Space Station: ISS-34 to ISS-40

    NASA Astrophysics Data System (ADS)

    Smith, Martin

    Radiation protection associated with human spaceflight is an important issue that becomes more vital as both the length of the mission and the distance from Earth increase. Radiation in deep space is a mixed field due to galactic cosmic rays (GCRs) and solar particle events (SPEs). In low-Earth orbit (LEO), protons and electrons trapped in the Van Allen radiation belts also make a major contribution to the radiation field. Neutrons encountered in LEO, for example on the International Space Station (ISS), are produced by nuclear interactions of GCRs and trapped protons with various elements in the walls and interior components of the spacecraft, and by neutron albedo after GCRs are incident on the Earth’s atmosphere. Previous investigations using bubble detectors (on Russian satellites, the Mir space station, the space shuttle, and the ISS) have shown that neutrons contribute significantly to the total biologically-equivalent radiation dose received by astronauts. As part of the ongoing Matroshka-R experiment, bubble detectors have been used to characterize neutron radiation on the ISS, starting with the ISS-13 mission in 2006. Two types of bubble detectors have been used for these experiments, namely space personal neutron dosimeters (SPNDs) and the space bubble-detector spectrometer (SBDS). The SBDS is a set of six detectors with different energy thresholds, which is used to determine the neutron energy spectrum. During the ISS-34 to ISS-40 expeditions (2012 - 2014) bubble detectors were used in both the US Orbital Segment (USOS) and the Russian segment of the ISS. The Radi-N2 experiment, a repeat of the 2009 Radi-N investigation, started during ISS-34 and included repeated measurements in four USOS modules: Columbus, the Japanese Experiment Module, the US Laboratory, and Node 2. Parallel experiments using a second set of detectors in the Russian segment included the first characterization of the neutron spectrum inside the tissue-equivalent Matroshka-R phantom

  8. Using luminescent materials as the active element for radiation sensors

    NASA Astrophysics Data System (ADS)

    Hollerman, William A.; Fontenot, Ross S.; Williams, Stephen; Miller, John

    2016-05-01

    Ionizing radiation poses a significant challenge for Earth-based defense applications as well as human and/or robotic space missions. Practical sensors based on luminescence will depend heavily upon research investigating the resistance of these materials to ionizing radiation and the ability to anneal or self-heal from damage caused by such radiation. In 1951, Birks and Black showed experimentally that the luminescent efficiency of anthracene bombarded by alphas varies with total fluence (N) as (I/I0) = 1/(1 + AN), where I is the luminescence yield, I0 is the initial yield, and A is a constant. The half brightness (N1/2) is defined as the fluence that reduce the emission light yield to half and is equal to is the inverse of A. Broser and Kallmann developed a similar relationship to the Birks and Black equation for inorganic phosphors irradiated using alpha particles. From 1990 to the present, we found that the Birks and Black relation describes the reduction in light emission yield for every tested luminescent material except lead phosphate glass due to proton irradiation. These results indicate that radiation produced quenching centers compete with emission for absorbed energy. The purpose of this paper is to present results from research completed in this area over the last few years. Particular emphasis will be placed on recent measurements made on new materials such as europium tetrakis dibenzoylmethide triethylammonium (EuD4TEA). Results have shown that EuD4TEA with its relatively small N1/2 might be a good candidate for use as a personal proton fluence sensor.

  9. 47 CFR 2.1053 - Measurements required: Field strength of spurious radiation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Measurements required: Field strength of spurious radiation. 2.1053 Section 2.1053 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... Procedures Certification § 2.1053 Measurements required: Field strength of spurious radiation....

  10. 47 CFR 2.1053 - Measurements required: Field strength of spurious radiation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Measurements required: Field strength of spurious radiation. 2.1053 Section 2.1053 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... Procedures Certification § 2.1053 Measurements required: Field strength of spurious radiation....

  11. 47 CFR 2.1053 - Measurements required: Field strength of spurious radiation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Measurements required: Field strength of spurious radiation. 2.1053 Section 2.1053 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... Procedures Certification § 2.1053 Measurements required: Field strength of spurious radiation....

  12. 47 CFR 2.1053 - Measurements required: Field strength of spurious radiation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Measurements required: Field strength of spurious radiation. 2.1053 Section 2.1053 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... Procedures Certification § 2.1053 Measurements required: Field strength of spurious radiation....

  13. Symposium Papers-Progress in Radiation and Energy Balance Measurement Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On November 2, 2004, an all-day symposium entitled “Progress in Radiation and Energy Balance Measurement Systems” was convened at the ASA-CSSA-SSSA annual meetings in Seattle, WA. Interest in the measurement of radiation and energy balance components at soil and plant canopy surfaces has seen a res...

  14. Tumor necrosis factor gene expression is mediated by protein kinase C following activation by ionizing radiation.

    SciTech Connect

    Hallahan, D. E.; Virudachalam, S.; Sherman, M. L.; Huberman, E.; Kufe, D. W.; Weichselbaum, R. R.; Univ. of Chicago; Dana-Farber Cancer Inst.; Univ. of Chicago

    1991-01-01

    Tumor necrosis factor (TNF) production following X-irradiation has been implicated in the biological response to ionizing radiation. Protein kinase C (PKC) is suggested to participate in TNF transcriptional induction and X-ray-mediated gene expression. We therefore studied radiation-mediated TNF expression in HL-60 cells with diminished PKC activity produced by either pretreatment with protein kinase inhibitors or prolonged 12-O-tetradecanoylphorbol-13-acetate treatment. Both treatments resulted in attenuation of radiation-mediated TNF induction. Consistent with these results, we found no detectable induction of TNF expression following X-irradiation in the HL-60 variant deficient in PKC-mediated signal transduction. The rapid activation of PKC following {gamma}-irradiation was established using an in vitro assay measuring phosphorylation of a PKC specific substrate. A 4.5-fold increase in PKC activity occurred 15 to 30 s following irradiation, which declined to baseline at 60 s. Two-dimensional gel electrophoresis of phosphoproteins extracted from irradiated cells demonstrated in vivo phosphorylation of the PKC specific substrate Mr 80,000 protein at 45 s following X-irradiation. These findings indicate that signal transduction via the PKC pathway is required for the induction of TNF gene expression by ionizing radiation.

  15. Measure of Legionella penumophila activity in situ

    SciTech Connect

    Fliermans, C.B.; Soracco, R.J.; Pope, D.H.

    1981-01-01

    Detection of Legionella pneumophila by serogroup-specific fluorescent antibodies was combined with a tetrazolium dye (INT) to measure electron transport activity. The biological uptake and reduction of the INT dye was studied in pure cultures and in natural water samples with respect to temperature. Uptake was complete within 60 min. Controls inhibited with formaldehyde demonstrated little activity. Both the in vitro and in situ determinations suggested that the electron transport system of Legionella was active over a temperature range of 25 to 60/sup 0/C.

  16. Measure of Legionella pneumophila activity in situ

    SciTech Connect

    Fliermans, C.B.; Soracco, R.J.; Pope, D.H.

    1981-01-01

    Detection of Legionella pneumophila by serogroup-specific fluorescent antibodies was combined with a tetrazolium dye (INT) to measure electron transport activity. The biological uptake and reduction of the INT dye was studied in pure cultures and in natural water samples with respect to temperature. Uptake was complete within 60 minutes. Controls inhibited with formaldehyde demonstrated little activity. Both the in vitro and in situ determinations suggested that the electron transport system of Legionella was active over a temperature range of 25/sup 0/ to 60/sup 0/C.

  17. Dosimeter for measuring skin dose and more deeply penetrating radiation

    DOEpatents

    Jones, Donald E.; Parker, DeRay; Boren, Paul R.

    1981-01-01

    A personnel dosimeter includes a plurality of compartments containing thermoluminescent dosimeter phosphors for registering radiation dose absorbed in the wearer's sensitive skin layer and for registering more deeply penetrating radiation. Two of the phosphor compartments communicate with thin windows of different thicknesses to obtain a ratio of shallowly penetrating radiation, e.g. beta. A third phosphor is disposed within a compartment communicating with a window of substantially greater thickness than the windows of the first two compartments for estimating the more deeply penetrating radiation dose. By selecting certain phosphors that are insensitive to neutrons and by loading the holder material with netruon-absorbing elements, energetic neutron dose can be estimated separately from other radiation dose. This invention also involves a method of injection molding of dosimeter holders with thin windows of consistent thickness at the corresponding compartments of different holders. This is achieved through use of a die insert having the thin window of precision thickness in place prior to the injection molding step.

  18. Activation of Protease Activated Receptor 2 by Exogenous Agonist Exacerbates Early Radiation Injury in Rat Intestine

    SciTech Connect

    Wang Junru; Boerma, Marjan; Kulkarni, Ashwini; Hollenberg, Morley D.; Hauer-Jensen, Martin

    2010-07-15

    Purpose: Protease-activated receptor-2 (PAR{sub 2}) is highly expressed throughout the gut and regulates the inflammatory, mitogenic, fibroproliferative, and nociceptive responses to injury. PAR{sub 2} is strikingly upregulated and exhibits increased activation in response to intestinal irradiation. We examined the mechanistic significance of radiation enteropathy development by assessing the effect of exogenous PAR{sub 2} activation. Methods and Materials: Rat small bowel was exposed to localized single-dose radiation (16.5 Gy). The PAR{sub 2} agonist (2-furoyl-LIGRLO-NH{sub 2}) or vehicle was injected intraperitoneally daily for 3 days before irradiation (before), for 7 days after irradiation (after), or both 3 days before and 7 days after irradiation (before-after). Early and delayed radiation enteropathy was assessed at 2 and 26 weeks after irradiation using quantitative histologic examination, morphometry, and immunohistochemical analysis. Results: The PAR{sub 2} agonist did not elicit changes in the unirradiated (shielded) intestine. In contrast, in the irradiated intestine procured 2 weeks after irradiation, administration of the PAR{sub 2} agonist was associated with more severe mucosal injury and increased intestinal wall thickness in all three treatment groups (p <.05) compared with the vehicle-treated controls. The PAR{sub 2} agonist also exacerbated the radiation injury score, serosal thickening, and mucosal inflammation (p <.05) in the before and before-after groups. The short-term exogenous activation of PAR{sub 2} did not affect radiation-induced intestinal injury at 26 weeks. Conclusion: The results of the present study support a role for PAR{sub 2} activation in the pathogenesis of early radiation-induced intestinal injury. Pharmacologic PAR{sub 2} antagonists might have the potential to reduce the intestinal side effects of radiotherapy and/or as countermeasures in radiologic accidents or terrorism scenarios.

  19. Laser-heating-based active optics for synchrotron radiation applications.

    PubMed

    Yang, Fugui; Li, Ming; Gao, Lidan; Sheng, Weifan; Liu, Peng; Zhang, Xiaowei

    2016-06-15

    Active optics has attracted considerable interest from researchers in synchrotron radiation facilities because of its capacity for x-ray wavefront correction. Here, we report a novel and efficient technique for correcting or modulating a mirror surface profile based on laser-heating-induced thermal expansion. An experimental study of the characteristics of the surface thermal deformation response indicates that the power of a milliwatt laser yields a bump height as low as the subnanometer scale and that the variation of the spot size modulates the response function width effectively. In addition, the capacity of the laser-heating technique for free-form surface modulation is demonstrated via a one-dimensional surface correction experiment. The developed method is a promising new approach toward effective x-ray active optics coupled with at-wavelength metrology techniques.

  20. Laser-heating-based active optics for synchrotron radiation applications.

    PubMed

    Yang, Fugui; Li, Ming; Gao, Lidan; Sheng, Weifan; Liu, Peng; Zhang, Xiaowei

    2016-06-15

    Active optics has attracted considerable interest from researchers in synchrotron radiation facilities because of its capacity for x-ray wavefront correction. Here, we report a novel and efficient technique for correcting or modulating a mirror surface profile based on laser-heating-induced thermal expansion. An experimental study of the characteristics of the surface thermal deformation response indicates that the power of a milliwatt laser yields a bump height as low as the subnanometer scale and that the variation of the spot size modulates the response function width effectively. In addition, the capacity of the laser-heating technique for free-form surface modulation is demonstrated via a one-dimensional surface correction experiment. The developed method is a promising new approach toward effective x-ray active optics coupled with at-wavelength metrology techniques. PMID:27304296

  1. Measurements and simulations of the radiation exposure to aircraft crew workplaces due to cosmic radiation in the atmosphere.

    PubMed

    Beck, P; Latocha, M; Dorman, L; Pelliccioni, M; Rollet, S

    2007-01-01

    As required by the European Directive 96/29/Euratom, radiation exposure due to natural ionizing radiation has to be taken into account at workplaces if the effective dose could become more than 1 mSv per year. An example of workers concerned by this directive is aircraft crew due to cosmic radiation exposure in the atmosphere. Extensive measurement campaigns on board aircrafts have been carried out to assess ambient dose equivalent. A consortium of European dosimetry institutes within EURADOS WG5 summarized experimental data and results of calculations, together with detailed descriptions of the methods for measurements and calculations. The radiation protection quantity of interest is the effective dose, E (ISO). The comparison of results by measurements and calculations is done in terms of the operational quantity ambient dose equivalent, H(10). This paper gives an overview of the EURADOS Aircraft Crew In-Flight Database and it presents a new empirical model describing fitting functions for this data. Furthermore, it describes numerical simulations performed with the Monte Carlo code FLUKA-2005 using an updated version of the cosmic radiation primary spectra. The ratio between ambient dose equivalent and effective dose at commercial flight altitudes, calculated with FLUKA-2005, is discussed. Finally, it presents the aviation dosimetry model AVIDOS based on FLUKA-2005 simulations for routine dose assessment. The code has been developed by Austrian Research Centers (ARC) for the public usage (http://avidos.healthphysics.at).

  2. Measuring cholinesterase activity in human saliva.

    PubMed

    Claus Henn, Birgit; McMaster, Suzanne; Padilla, Stephanie

    2006-10-01

    To assess the potential for using saliva in pesticide biomonitoring, the consistency of cholinesterase activity in human saliva collected over time was examined. In this pilot study, saliva was collected from 20 healthy adults once per week for 5 consecutive weeks using 2 different collection methods: a disposable plastic pipette, and a cotton-wool roll. A brief questionnaire was conducted each week to document changes in exposure to cholinesterase inhibitors for the duration of the sampling. To measure cholinesterase activity, an existing radiometric method was modified to make it suitable for human saliva. Using this method, cholinesterase activity was measurable in saliva, and duplicate samples showed reliable repeatability. Activity in both collection methods ranged from 3 to 265 nmol/h/ml saliva (mean = 52 +/- 37 [SD] nmol/h/ml saliva). For some individuals, enzyme activity was consistent over the five sampling weeks; for others, activity was highly variable. Coefficients of variation (CVs) were calculated to assess variability, and mean CVs were the same for both collection methods (about 35%). Adjusting for protein concentration in the pipette-collected samples did not change results. Both collection methods worked well for collecting between 1 and 3 ml saliva, but at the majority of visits (86%), participants preferred the cotton-wool roll. Results from this study suggest that saliva may be a useful indicator of potential neurotoxic effects from exposure to organophosphorus and carbamate pesticides, but that factors affecting variability should be explored further.

  3. Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory.

    PubMed

    Zeitlin, C; Hassler, D M; Cucinotta, F A; Ehresmann, B; Wimmer-Schweingruber, R F; Brinza, D E; Kang, S; Weigle, G; Böttcher, S; Böhm, E; Burmeister, S; Guo, J; Köhler, J; Martin, C; Posner, A; Rafkin, S; Reitz, G

    2013-05-31

    The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011, and for most of the 253-day, 560-million-kilometer cruise to Mars, the Radiation Assessment Detector made detailed measurements of the energetic particle radiation environment inside the spacecraft. These data provide insights into the radiation hazards that would be associated with a human mission to Mars. We report measurements of the radiation dose, dose equivalent, and linear energy transfer spectra. The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert.

  4. Parametric Channeling Radiation and its Application to the Measurement of Electron Beam Energy

    SciTech Connect

    Takabayashi, Y.

    2010-06-23

    We have proposed a method for observing parametric channeling radiation (PCR) and of applying it to the measurement of electron beam energy. The PCR process occurs if the energy of the channeling radiation coincides with the energy of the parametric X-ray radiation (PXR). The PCR process can be regarded as the diffraction of 'virtual channeling radiation'. We developed a scheme for beam energy measurement and designed an experimental setup. We also estimated the beam parameters, and calculated the angular distributions of PXR and PCR. These considerations indicate that the observation of PCR is promising.

  5. Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory.

    PubMed

    Zeitlin, C; Hassler, D M; Cucinotta, F A; Ehresmann, B; Wimmer-Schweingruber, R F; Brinza, D E; Kang, S; Weigle, G; Böttcher, S; Böhm, E; Burmeister, S; Guo, J; Köhler, J; Martin, C; Posner, A; Rafkin, S; Reitz, G

    2013-05-31

    The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011, and for most of the 253-day, 560-million-kilometer cruise to Mars, the Radiation Assessment Detector made detailed measurements of the energetic particle radiation environment inside the spacecraft. These data provide insights into the radiation hazards that would be associated with a human mission to Mars. We report measurements of the radiation dose, dose equivalent, and linear energy transfer spectra. The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert. PMID:23723233

  6. Measurement of soil radioactivity levels and radiation hazard assessment in southern Rechna interfluvial region, Pakistan.

    PubMed

    Jabbar, Abdul; Arshed, Waheed; Bhatti, Arshad Saleem; Ahmad, Syed Salman; Akhter, Perveen; Rehman, Saeed-Ur; Anjum, Muhammad Iftikhar

    2010-10-01

    Rechna interfluvial region is one of the main regions of Punjab, Pakistan. It is the area which is lying between River Ravi and River Chenab, alluvial-filled. Radioactivity levels in soil samples, collected from southern Rechna interfluvial region, Pakistan, have been estimated by using gamma-ray spectrometric technique. (226)Ra, (232)Th, the primordial radionuclide (40)K, and the artificial radionuclide (137)Cs have been measured in the soil of the study area. The mean radioactivity levels of (226)Ra, (232)Th, (40)K, and (137)Cs were found to be 50.6 +/- 1.7, 62.3 +/- 3.2, 662.2 +/- 32.1, and 3.1 +/- 0.3 Bq kg(-1), respectively. The mean radium equivalent activity (Ra(eq)), outdoor radiation hazard index (H(out)), indoor radiation hazard index (H(in)), and terrestrial absorbed dose rate for the area under study were determined as 190.8 +/- 8.7 Bq kg(-1), 0.52, 0.65, and 69.8 nGy h(-1), respectively. The annual effective dose to the general public was found to be 0.43 mSv. This value lies well below the limit of 1 mSv for general public as recommended by the International Commission on Radiological Protection. The measured values are comparable with other global radioactivity measurements and are found to be safe for the public and the environment.

  7. Atmospheric Radiation Measurement (ARM) Data from the North Slope Alaska (NSA) Site

    DOE Data Explorer

    The Atmospheric Radiation Measurement (ARM) Program is the largest global change research program supported by the U.S. Department of Energy. The primary goal of the ARM Program is to improve the treatment of cloud and radiation physics in global climate models in order to improve the climate simulation capabilities of these models. To achieve this goal, ARM scientists and researchers around the world use continuous data obtained through the ARM Climate Research Facility. ARM maintains four major, permanent sites for data collection and deploys the ARM Mobile Facility to other sites as determined. The North Slope of Alaska (NSA) site is a permanent site providing data about cloud and radiative processes at high latitudes. These data are being used to refine models and parameterizations as they relate to the Arctic. Centered at Barrow and extending to the south (to the vicinity of Atqasuk), west (to the vicinity of Wainwright), and east (towards Oliktok), the NSA site has become a focal point for atmospheric and ecological research activity on the North Slope. Approximately 300,000 NSA data sets from 1993 to the present reside in the ARM Archive at http://www.archive.arm.gov/. Users will need to register for a password, but all files are then free for viewing or downloading. The ARM Archive physically resides at the Oak Ridge National Laboratory.

  8. Monthly ratios of PAR to global solar radiation measured at northern Tibetan Plateau, China

    SciTech Connect

    Li, Ren; Zhao, Lin; Xiao, Yao; Liu, Guangyue; Sun, Linchan; Ding, Yongjian; Wang, Sheng; Ji, Guoliang

    2010-06-15

    Using narrowband and broadband solar radiation measurements collected at Wudaoliang (WDL) site in northern Tibetan Plateau (NTP) from September 1993 to December 1998, the relationship between monthly photosynthetically active radiation (Q{sub P}) and global solar radiation (R{sub S}) values is analyzed. Temporal variability of the ratio (Q{sub P}/R{sub S}) and its further dependence on several meteorological variables are presented. The narrowband ratio exhibited diurnal and seasonal variability with high values during morning and afternoon hours and low values around noon in winter time, whereas during summer period the ratio was decreased from morning to afternoon. The ratio (Q{sub P}/R{sub S}) was correlated positively with several atmospheric parameters such as water vapor pressure and low-level cloud amount; in contrast, the ratio was negatively correlated with clearness index, relative sunshine duration and atmospheric turbidity. It was also found that both the relative sunshine duration and water vapor pressure are the most influential parameters on the estimations of the spectral PAR ratio. Finally, an empirically derived model is proposed for estimating monthly average PAR values over the northern Tibetan Plateau. Verification results further ensured that the proposed model predicts monthly global PAR values accurately. (author)

  9. Microdosimetric-based risk factors for radiation received in space activities during a trip to Mars.

    PubMed

    Zaider, M

    1996-06-01

    A system for evaluating quality factors, Q, based on the microdosimetric distribution of the radiation field of interest has been set up; it makes use of a specific quality function (SQF) to obtain--given microdosimetric spectra--values for Q. The advantages of a system based on lineal energy are well recognized. Furthermore, recent studies have shown that spectra in 1-microm diameter tissue-equivalent spherical volumes reproduce correctly (in the sense of this formalism) measured RBE values, and thus a proportional counter would be usable as a practical instrument for radiation protection. All specific quality functions, q(y), available to date have been calculated from in vitro cellular data. To extend this approach to radiations of interest in space activities we have recently obtained a new function q(y) for in vivo radiogenic neoplasia using data on the Harderian gland of the mouse. These data were obtained for charged particles and energies relevant to space exposures. Furthermore, we introduce a new procedure that allows one to obtain--here with the use of microdosimetric distributions for the Hiroshima-Nagasaki radiation fields--risk factors scaled from the A-bomb survivorship results. We apply these concepts to particles and energies representing the galactic spectrum. We estimate that for a trip to Mars (450 d) the excess lifetime cancer mortality due to galactic cosmic ray (GCR) radiation is 0.037. This is about 50% lower than the risk coefficient obtained with the aid of standard (LET-based) quality factors.

  10. An information theory approach for evaluating earth radiation budget (ERB) measurements - Nonuniform sampling of reflected shortwave radiation

    NASA Technical Reports Server (NTRS)

    Barkstrom, Bruce R.; Direskeneli, Haldun; Halyo, Nesim

    1992-01-01

    An information theory approach to examine the temporal nonuniform sampling characteristics of shortwave (SW) flux for earth radiation budget (ERB) measurements is suggested. The information gain is computed by computing the information content before and after the measurements. A stochastic diurnal model for the SW flux is developed, and measurements for different orbital parameters are examined. The methodology is applied to specific NASA Polar platform and Tropical Rainfall Measuring Mission (TRMM) orbital parameters. The information theory approach, coupled with the developed SW diurnal model, is found to be promising for measurements involving nonuniform orbital sampling characteristics.

  11. Atmospheric Radiation Measurement program climate research facility operations quarterly report.

    SciTech Connect

    Sisterson, D. L.; Decision and Information Sciences

    2006-09-06

    Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year dating back to 1998. The U.S. Department of Energy requires national user facilities to report time-based operating data. The requirements concern the actual hours of operation (ACTUAL); the estimated maximum operation or uptime goal (OPSMAX), which accounts for planned downtime; and the VARIANCE [1-(ACTUAL/OPSMAX)], which accounts for unplanned downtime. The OPSMAX time for the third quarter for the Southern Great Plains (SGP) site is 2,074.80 hours (0.95 x 2,184 hours this quarter). The OPSMAX for the North Slope Alaska (NSA) locale is 1,965.60 hours (0.90 x 2,184), and that for the Tropical Western Pacific (TWP) locale is 1,856.40 hours (0.85 x 2,184). The OPSMAX time for the ARM Mobile Facility (AMF) is 2,074.80 hours (0.95 x 2,184). The differences in OPSMAX performance reflect the complexity of local logistics and the frequency of extreme weather events. It is impractical to measure OPSMAX for each instrument or data stream. Data availability reported here refers to the average of the individual, continuous data streams that have been received by the Archive. Data not at the Archive are caused by downtime (scheduled or unplanned) of the individual instruments. Therefore, data availability is directly related to individual instrument uptime. Thus, the average percent of data in the Archive

  12. SPHINX Measurements of Radiation Induced Conductivity of Foam

    SciTech Connect

    Ballard, W.P.; Beutler, D.E.; Burt, M.; Dudley, K.J.; Stringer, T.A.

    1998-12-14

    Experiments on the SPHINX accelerator studying radiation-induced conductivity (RIC) in foam indicate that a field-exclusion boundary layer model better describes foam than a Maxwell-Garnett model that treats the conducting gas bubbles in the foam as modifying the dielectric constant. In both cases, wall attachment effects could be important but were neglected.

  13. 47 CFR 15.33 - Frequency range of radiated measurements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... level of radiated emissions within the frequency range 9 kHz to 30 MHz, such as a CB receiver or a device designed to conduct its radio frequency emissions via connecting wires or cables, e.g., a carrier... used in the device, without going below 9 kHz (25 MHz for CB receivers), up to the frequency shown...

  14. 47 CFR 15.33 - Frequency range of radiated measurements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... level of radiated emissions within the frequency range 9 kHz to 30 MHz, such as a CB receiver or a device designed to conduct its radio frequency emissions via connecting wires or cables, e.g., a carrier... used in the device, without going below 9 kHz (25 MHz for CB receivers), up to the frequency shown...

  15. 47 CFR 15.33 - Frequency range of radiated measurements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... level of radiated emissions within the frequency range 9 kHz to 30 MHz, such as a CB receiver or a device designed to conduct its radio frequency emissions via connecting wires or cables, e.g., a carrier... used in the device, without going below 9 kHz (25 MHz for CB receivers), up to the frequency shown...

  16. 47 CFR 15.33 - Frequency range of radiated measurements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... level of radiated emissions within the frequency range 9 kHz to 30 MHz, such as a CB receiver or a device designed to conduct its radio frequency emissions via connecting wires or cables, e.g., a carrier... used in the device, without going below 9 kHz (25 MHz for CB receivers), up to the frequency shown...

  17. Nuclear Technology Series. Course 11: Radiation Detection and Measurement.

    ERIC Educational Resources Information Center

    Technical Education Research Center, Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  18. Terrestrial outgoing radiation measurements with small satellite mission

    NASA Astrophysics Data System (ADS)

    Zhu, Ping; Dewitte, Steven; Karatekin, Ozgur; Chevalier, André; Conscience, Christian

    2015-04-01

    The solar force is the main driver of the Earth's climate. For a balanced climate system, the incoming solar radiation is equal to the sum of the reflected visible and reemitted thermal radiation at top of the atmosphere (TOA). Thus the energy imbalance plays an important role to diagnose the health of nowadays climate. However it remains a challenge to directly track the small Energy imbalance in Earth's Radiation Budget (EIERB) from space due to the complicities of the Earth's climate system and the limitation on long term stability of space instrument. The terrestrial outgoing radiation (TOR) has been recoded with a Bolometric Oscillation Sensor onboard PICAD microsatellite. In this presentation, we will report the three years TOR observed with PICARD-BOS and its further comparison with the CERES product. However the data acquired from this mission is still not enough to derive the EIERB. But the heritage gained from this experiment shields a light on the EIERB tracking with the small satellite even a cubesat mission.

  19. Activity measurements of radon from construction materials.

    PubMed

    Fior, L; Nicolosi Corrêa, J; Paschuk, S A; Denyak, V V; Schelin, H R; Soreanu Pecequilo, B R; Kappke, J

    2012-07-01

    This work presents the results of radon concentration measurements of construction materials used in the Brazilian industry, such as clay (red) bricks and concrete blocks. The measurements focused on the detection of indoor radon activity during different construction stages and the analysis of radionuclides present in the construction materials. For this purpose, sealed chambers with internal dimensions of approximately 60×60×60 cm3 were built within a protected and isolated laboratory environment, and stable air humidity and temperature levels were maintained. These chambers were also used for radon emanation reduction tests. The chambers were built in four major stages: (1) assembly of the walls using clay (red) bricks, concrete blocks, and mortar; (2) installation of plaster; (3) finishing of wall surface using lime; and (4) insulation of wall surface and finishing using paint. Radon measurements were performed using polycarbonate etched track detectors. By comparing the three layers applied to the masonry walls, it was concluded that only the last step (wall painting using acrylic varnish) reduced the radon emanation, by a factor of approximately 2. Samples of the construction materials (clay bricks and concrete blocks) were ground, homogenized, and subjected to gamma-ray spectrometry analysis to evaluate the activity concentrations of 226Ra, 232Th and 40K. The values for the index of the activity concentration (I), radium equivalent activity (Raeq), and external hazard index (Hext) showed that these construction materials could be used without restrictions or concern about the equivalent dose limit (1 mSv/year).

  20. Ozonesonde measurements from the Atmospheric Radiation Measurement (ARM) site in Billings, Oklahoma

    SciTech Connect

    1998-12-01

    Ozonesonde instruments were prepared and released at the Atmospheric Radiation Measurement (ARM) site located near Billings, Oklahoma. Ozone sensors, associated radiosondes, balloons, and other parts and pieces required for the ozone observations were provided by WFF on a reimbursable arrangement with ANL. Observations were scheduled daily at 1,700 UTC beginning on September 22, 1995. Attempts to maintain this schedule were frustrated by a few simultaneous operations involving different electronic devices in use resulting in considerable rf noise. Since radiosondes are necessarily low-cost instruments their reception is particularly susceptible to noisy rf fields. Overall, however, 36 ozonesonde flights were made with the last observation occurring on November 1, 1995. Ozone data were processed on-site through the ground-station software and preliminary data delivered to Mike Splitt at the ARM site.

  1. Effect of smoke and clouds on the transmissivity of photosynthetically active radiation inside the canopy

    NASA Astrophysics Data System (ADS)

    Yamasoe, M. A.; von Randow, C.; Manzi, A. O.; Schafer, J. S.; Eck, T. F.; Holben, B. N.

    2006-05-01

    Biomass burning activities emit high concentrations of aerosol particles to the atmosphere. Such particles can interact with solar radiation, decreasing the amount of light reaching the surface and increasing the fraction of diffuse radiation through scattering processes, and thus has implications for photosynthesis within plant canopies. This work reports results from photosynthetically active radiation (PAR) and aerosol optical depth (AOD) measurements conducted simultaneously at Reserva Biológica do Jaru (Rondonia State, Brazil) during LBA/SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia/ Smoke, Aerosols, Clouds, Rainfall, and Climate) and RaCCI (Radiation, Cloud, and Climate Interactions in the Amazon during the Dry-to-Wet Transition Season) field experiments from 15 September to 15 November 2002. AOD values were retrieved from an AERONET (Aerosol Robotic Network) radiometer, MODIS (Moderate Resolution Spectroradiometer) and a portable sunphotometer from the United States Department of Agriculture - Forest Service. Significant reduction of PAR irradiance at the top of the canopy was observed due to the smoke aerosol particles layer. This radiation reduction affected turbulent fluxes of sensible and latent heats. The increase of AOD also enhanced the transmission of PAR inside the canopy. As a consequence, the availability of diffuse radiation was enhanced due to light scattering by the aerosol particles. A complex relationship was identified between light availability inside the canopy and net ecosystem exchange (NEE). The results showed that the increase of aerosol optical depth corresponded to an increase of CO2 uptake by the vegetation. However, for even higher AOD values, the corresponding NEE was lower than for intermediate values. As expected, water vapor pressure deficit (VPD), retrieved at 28m height inside the canopy, can also affect photosynthesis. A decrease in NEE was observed as VPD increased. Further studies are needed to better

  2. Measuring segregation: an activity space approach.

    PubMed

    Wong, David W S; Shaw, Shih-Lung

    2011-06-01

    While the literature clearly acknowledges that individuals may experience different levels of segregation across their various socio-geographical spaces, most measures of segregation are intended to be used in the residential space. Using spatially aggregated data to evaluate segregation in the residential space has been the norm and thus individual's segregation experiences in other socio-geographical spaces are often de-emphasized or ignored. This paper attempts to provide a more comprehensive approach in evaluating segregation beyond the residential space. The entire activity spaces of individuals are taken into account with individuals serving as the building blocks of the analysis. The measurement principle is based upon the exposure dimension of segregation. The proposed measure reflects the exposure of individuals of a referenced group in a neighborhood to the populations of other groups that are found within the activity spaces of individuals in the referenced group. Using the travel diary data collected from the tri-county area in southeast Florida and the imputed racial-ethnic data, this paper demonstrates how the proposed segregation measurement approach goes beyond just measuring population distribution patterns in the residential space and can provide a more comprehensive evaluation of segregation by considering various socio-geographical spaces.

  3. Measuring segregation: an activity space approach

    PubMed Central

    Shaw, Shih-Lung

    2010-01-01

    While the literature clearly acknowledges that individuals may experience different levels of segregation across their various socio-geographical spaces, most measures of segregation are intended to be used in the residential space. Using spatially aggregated data to evaluate segregation in the residential space has been the norm and thus individual’s segregation experiences in other socio-geographical spaces are often de-emphasized or ignored. This paper attempts to provide a more comprehensive approach in evaluating segregation beyond the residential space. The entire activity spaces of individuals are taken into account with individuals serving as the building blocks of the analysis. The measurement principle is based upon the exposure dimension of segregation. The proposed measure reflects the exposure of individuals of a referenced group in a neighborhood to the populations of other groups that are found within the activity spaces of individuals in the referenced group. Using the travel diary data collected from the tri-county area in southeast Florida and the imputed racial–ethnic data, this paper demonstrates how the proposed segregation measurement approach goes beyond just measuring population distribution patterns in the residential space and can provide a more comprehensive evaluation of segregation by considering various socio-geographical spaces. PMID:21643546

  4. Correlation among lung damage after radiation, amount of lipid peroxides, and antioxidant enzyme activities

    SciTech Connect

    Nozue, M.; Ogata, T.

    1989-04-01

    The correlation between lipid peroxidation and morphologic changes was examined in Sprague-Dawley rat lungs after 30 Gy single thoracic radiation. The rats were sacrificed every week until the end of the fifth week after radiation. The left lungs were used for the measurement of lipid peroxides and antioxidant enzymes activities. The right lungs were examined by light and electron microscopy. Amounts of lung lipid peroxides were within normal limits, and no cellular degenerative changes were observed in the lungs except for subendothelial and interstitial edema 2 weeks after radiation. Lipid peroxides drastically increased and marked degenerative cellular changes such as edematous swelling, vacuolation, and destruction of cell membranes occurred in the alveolar septa following the third week after radiation. The activities of catalase were significantly higher during the period from the second to the fifth week and those of superoxide dismutase and glutathione peroxidase increased at the end of the fifth week. Our results demonstrated that the acceleration of lipid peroxidation was well correlated with the morphologic expression of cell injury in the irradiated lungs.

  5. Mineral Dust Impact on Short- and Long-Wave Radiation and Comparison with Ceres Measurements

    NASA Astrophysics Data System (ADS)

    Romano, Salvatore; Perrone, Maria Rita

    2016-06-01

    Clear-sky downward and upward radiative flux measurements both in the short- and in the long-wave spectral range have been used to estimate and analyze the radiation changes at the surface due to the mineral dust advection at a Central Mediterranean site. Then, short- and long-wave radiative fluxes retrieved from the CERES (Clouds and the Earth's Radiant Energy System) radiometer sensors operating on board the EOS (Earth Observing System) AQUA and TERRA platforms have been used to evaluate the mineral dust radiative impact at the top of the atmosphere. Satellite-derived radiative fluxes at the surface have been compared with corresponding ground-based flux measurements, collocated in space and time, to better support and understand the desert dust radiative impact. Results referring to the year 2012 are reported.

  6. Modeling the ratio of photosynthetically active radiation to broadband global solar radiation using ground and satellite-based data in the tropics

    NASA Astrophysics Data System (ADS)

    Janjai, S.; Wattan, R.; Sripradit, A.

    2015-12-01

    Data from four stations in Thailand are used to model the ratio of photosynthetically active radiation (PAR) to broadband global solar radiation. The model expresses the ratio of PAR-to-broadband global solar radiation as a function of cloud index, aerosol optical depth, precipitable water, total ozone column and solar zenith angle. Data from the MTSAT-1R and OMI/AURA satellites are used to estimate the cloud index and total ozone column, respectively at each of the four stations, while aerosol optical depth and precipitable water are retrieved from Aerosol Robotic Network (AERONET) sunphotometer measurements, also available at each station. When tested against hourly measurements, the model exhibits a coefficient of variance (R2) equal to or better than 0.96, and root mean square difference (RMSD) in the range of 7.3-7.9% and mean bias difference (MBD) of -4.5% to 3.5%. The model compares favorably with other existing models.

  7. The radiation measurement applied to beam lifetime study on the synchrotron radiation facilities

    NASA Astrophysics Data System (ADS)

    Li, Yuxiong; Li, Juexin; Liu, Zuping; Cui, Yonggang; Gong, Guanghua; Shao, Beibei

    2003-06-01

    To collect beam loss information from an accelerator radiation field is helpful to machine study and operation. For a synchrotron radiation storage ring, shower electrons give a distinct clue to loss location and a BLM-XS model detector is suitable to detect them. Recently, we set up a new beam loss monitoring system by this method for National Synchrotron Radiation Laboratory (NSRL) storage ring. It does not interfere with the vacuum chamber and machine operation. Different from other systems, the detectors are used in pairs, fixed on opposite sides of the chamber separately. Some interesting phenomena about beam lifetime were observed. We located exactly where an excessive beam loss took place during ramping process and solved the problem. It was proved that gas accumulated at the front ends of photo-beam lines strongly impacted the electron beam and led to beam lifetime decreases. The cause of beam lifetime decrease because of superconducting wiggler is discussed.

  8. Biological activities caused by far-infrared radiation

    NASA Astrophysics Data System (ADS)

    Inoué, Shojiro; Kabaya, Morihiro

    1989-09-01

    Contrary to previous presumption, accumulated evidence indicates that far-infrared rays are biologically active. A small ceramic disk that emist far-infrared rays (4 16 μm) has commonly been applied to a local spot or a whole part of the body for exposure. Pioneering attempts to experimentally analyze an effect of acute and chronic radiation of far-infrared rays on living organisms have detected a growth-promoting effect in growing rats, a sleep-modulatory effect in freely behaving rats and an insomiac patient, and a blood circulation-enhancing effect in human skin. Question-paires to 542 users of far-infrared radiator disks embedded in bedelothes revealed that the majority of the users subjectively evaluated an improvement of their health. These effects on living organisms appear to be non-specifically triggered by an exposure to far-infrared rays, which eventually induce an increase in temperature of the body tissues or, more basically, an elevated motility of body fluids due to decrease in size of water clusters.

  9. Characterization of AN Actively Cooled Metal Foil Thermal Radiation Shield

    NASA Astrophysics Data System (ADS)

    Feller, J. R.; Kashani, A.; Helvensteijn, B. P. M.; Salerno, L. J.

    2010-04-01

    Zero boil-off (ZBO) or reduced boil-off (RBO) systems that involve active cooling of large cryogenic propellant tanks will most likely be required for future space exploration missions. For liquid oxygen or methane, such systems could be implemented using existing high technology readiness level (TRL) cryocoolers. However, for liquid hydrogen temperatures (˜20 K) no such coolers exist. In order to partially circumvent this technology gap, the concept of broad area cooling (BAC) has been developed, whereby a low mass thermal radiation shield could be maintained at temperatures around 100 K by steady circulation of cold pressurized gas through a network of narrow tubes. By this method it is possible to dramatically reduce the radiative heat leak to the 20 K tank. A series of experiments, designed to investigate the heat transfer capabilities of BAC systems, have been conducted at NASA Ames Research Center (ARC). Results of the final experiment in this series, investigating heat transfer from a metal foil film to a distributed cooling line, are presented here.

  10. Atmospheric radiation measurement program facilities newsletter, July 2002.

    SciTech Connect

    Holdridge, D. J.

    2002-08-12

    ARM Participating in Off-site Intensive Operational Period--The ARM Program is playing a role in the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) intensive operational period (IOP), under way through July in South Florida. The objective of CRYSTAL-FACE is to investigate the physical properties and formation processes of tropical cirrus clouds. The ARM Program has deployed a suite of ground-based instruments in Florida for CRYSTAL-FACE. In addition, the National Aeronautics and Space Administration provides six research aircraft equipped with state-of-the-art instruments to measure characteristics of cirrus clouds and their ability to alter the temperature of the atmosphere. The reliability of climate predictions depends on the accuracy of computer models of climate. Interactions between clouds and solar radiation are a major source of current uncertainty in the models, hindering accurate climate prediction. A goal of CRYSTAL-FACE is to improve on the way clouds are represented in and integrated into the models and thus achieve more reliable climate predictions. CRYSTAL-FACE will be followed in 2004 by CRYSTAL-TWP, to be held at ARM's Tropical Western Pacific (TWP) location on Manus and Nauru Islands. New Storage Building Proposed for Central Facility--Now in the design phase is a new storage building to be erected at the central facility, west of the shipping and receiving trailer. The added storage is needed because shipping needs for the TWP are now being handled by the SGP site. New Seminole Extended Facility Location Approved--The extended facility formerly on the property of the Seminole Industrial Foundation had to be removed from service in April, after the land was sold to a new owner. Both the foundation and the new land owner offered options for new extended facility locations in the area. An Environmental Evaluation Notification Form has now been approved by the USDOE (ARM Program sponsor), as

  11. Measurement of the linear polarization of channeling radiation in silicon and diamond

    SciTech Connect

    Rzepka, M.; Buschhorn, G.; Diedrich, E.; Kotthaus, R.; Kufner, W.; Roessl, W.; Schmidt, K.H.; Hoffmann-Stascheck, P.; Genz, H.; Nething, U.; Richter, A.; Sellschop, J.P.F.

    1995-07-01

    Utilizing 90{degree} Compton scattering the linear polarization of channeling radiation produced at the superconducting accelerator S-DALINAC with 62 MeV electrons in silicon and diamond has been measured in the energy range between 50 and 400 keV. Planar channeling radiation due to transitions involving transversal bound as well as unbound states is completely linearly polarized perpendicular to the channeling plane. Axial channeling radiation does not show linear polarization.

  12. Site/Systems Operations, Maintenance and Facilities Management of the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) Site

    SciTech Connect

    Wu, Susan

    2005-08-01

    This contract covered the site/systems operations, maintenance, and facilities management of the DOE Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) Site.

  13. Attributes and templates from active measurements with {sup 252}Cf

    SciTech Connect

    Mihalczo, J.T.; Mattingly, J.K.

    2000-02-01

    Active neutron interrogation is useful for the detection of shielded HEU and could also be used for Pu. In an active technique, fissile material is stimulated by an external neutron source to produce fission with the emanation of neutrons and gamma rays. The time distribution of particles leaving the fissile material is measured with respect to the source emission in a variety of ways. A variety of accelerator and radioactive sources can be used. Active interrogation of nuclear weapons/components can be used in two ways: template matching or attribute estimation. Template matching compares radiation signatures with known reference signatures and for treaty applications has the problem of authentication of the reference signatures along with storage and retrieval of templates. Attribute estimation determines, for example, the fissile mass from various features of the radiation signatures and does not require storage of radiation signatures but does require calibration, which can be repeated as necessary. A nuclear materials identification system (NMIS) has been in use at the Oak Ridge Y-12 Plant for verification of weapons components being received and in storage by template matching and has been used with calibrations for attribute (fissile mass) estimation for HEU metal. NMIS employs a {sup 252}Cf source of low intensity (< 2 x 10{sup 6} n/sec) such that the dose at 1 m is approximately twice that on a commercial airline at altitude. The use of such a source presents no significant safety concerns either for personnel or nuclear explosive safety, and has been approved for use at the Pantex Plant on fully assembled weapons systems.

  14. Atmospheric Radiation Measurement program (ARM) -- Summer 1995 review

    SciTech Connect

    MacDonald, G.; Ruderman, M.; Treiman, S.

    1995-10-01

    ARM is a highly focused program designed to improve the understanding of the transport of infrared and solar radiation through the atmosphere. The program pays particular attention to the interaction of radiation with the three phases of water. The goals of ARM are usually articulated in terms of improvements in climate models. The authors agree that ARM can indeed make significant contributions to the understanding of climate change. In addition the authors believe that the results of the program will have wide applicability to a broad range of problems, including more accurate short-term and seasonal weather forecasting. This report examines the issues of anomalous atmospheric absorption and makes recommendations concerning future directions for the ARM program.

  15. Measuring psychological engagement in youth activity involvement.

    PubMed

    Ramey, Heather L; Rose-Krasnor, Linda; Busseri, Michael A; Gadbois, Shannon; Bowker, Anne; Findlay, Leanne

    2015-12-01

    Although psychological engagement (e.g., enjoyment, concentration) may be critical in fostering positive outcomes of youth activity participation, too few studies have been conducted to establish its role in development. Furthermore, an established measurement tool is lacking. In the current study, we evaluated a brief engagement measure with two Canadian samples of youth (Sample 1, N = 290, mean age = 16.9 years, 62% female; Sample 2, N = 1827, mean age = 13.1 years, 54% female). We conducted a confirmatory factor analysis with structural equation modeling to examine the hypothesized structure of the model. We also assessed the measure's validity by testing relations between engagement and both perceived outcomes and positive features of activity settings. Psychological engagement was best captured by three latent cognitive, affective, and relational/spiritual factors and a second-order latent factor. Also, as anticipated, psychological engagement was associated with features of the activity setting and perceived impact.

  16. Radiation levels in cyclotron-radiochemistry facility measured by a novel comprehensive computerized monitoring system

    NASA Astrophysics Data System (ADS)

    Mishani, E.; Lifshits, N.; Osavistky, A.; Kaufman, J.; Ankry, N.; Tal, N.; Chisin, R.

    1999-04-01

    Radiation levels in a cyclotron-radiochemistry facility were measured during the production of commonly used PET radiopharmaceuticals by a comprehensive computerized monitoring system. The system consists of three major components: on-line radiation monitoring channels, an area control unit, and a gas waste management unit. During production the radiation levels were measured in the cyclotron vault, inside automatic chemistry production and research shielded cells, in the radiochemistry room, in the gas waste decay tank, in the chimney filters, and at the top of the cells chimney. Each detector was calibrated in a known radiation field, and a special detector dead time correction was performed in order to achieve detected signal-to-radiation linearity for the Geiger tubes located in the radiochemistry production and research cells. During production of C-11 and O-15 PET radiopharmaceuticals, high radiation levels were measured in the gas waste decay tank (240 and 80 mR/h, respectively). In contrast, the radiation levels at the chimney filters and at the top of the cells chimney did not exceed the International Atomic Energy Agency (IAEA) Drive Air Concentration (DAC) recommended for C-11 or O-15. During production of FDG, high radiation levels were measured at the chimney filters, however the radiation level at the top of the chimney (3.7 μCi/m 3) did not exceed the F-18 DAC recommendation (27 μCi/m 3). Low radiation levels of approximately 0.5-1 mR/h were measured in the radiochemistry room during production of PET radiopharmaceuticals. In the cyclotron vault, 2 min after bombardment the radiation levels at 2 m from the cyclotron decreased to 1-2 mR/h. The addition of a gas waste decay system to computerized monitoring channels located near each strategic point of the site allows for a comprehensive survey of the radiochemical processes.

  17. A novel dosimeter for measuring the amount of radiation exposure of surgeons during percutaneous nephrolithotomy: Instadose™

    PubMed Central

    Yuruk, Emrah; Gureser, Gokhan; Tuken, Murat; Ertas, Kasim

    2016-01-01

    Introduction The aim of this study was to demonstrate the efficacy of Instadose™, a novel dosimeter designed for radiation workers to provide a measurement of the radiation dose at any time from any computer; to determine the amount of radiation exposure during percutaneous nephrolithotomy (PNL); and to evaluate the factors that affect the amount of radiation exposed. Material and methods Two experienced surgeons wore Instadose™ on the outer part of their lead aprons during the PNL procedures performed between December 2013 and July 2014. Patient demographics and stone characteristics were noted. Factors affecting radiation dose were determined. Fluoroscopic screening time was compared with the amount of radiation in order to validate the measurements of Instadose™. Results Overall, 51 patients with a mean age of 43.41 ±18.58 (range 1–75) years were enrolled. Male to female ratio was 35/16. The amount of radiation was greater than 0.01mSv in only 19 (37.25%) cases. Stone location complexity (p = 0.380), dilation type (p = 0.584), stone size (p = 0.565), dilation size (p = 0.891) and access number (p = 0.268) were not associated with increased radiation exposure. Instadose™ measurements were correlated with fluoroscopic screening time (r = 0.519, p = 0.001). Conclusions Instadose™ is a useful tool for the measurement of radiation exposure during PNL. The advantage of measuring the amount of radiation exposure after each PNL operation is that it may aid urologists in taking appropriate precautions to minimize the risk of radiation related complications. PMID:27551558

  18. Radiation Protection. Measurement of radioactivity in the environment - Air- radon 222. A proposed ISO standard.

    NASA Astrophysics Data System (ADS)

    Gillmore, G.; Woods, M.

    2009-04-01

    Radon isotopes (222, 220, 219) are radioactive gases produced by the disintegration of radium isotopes 226, 224 and 223, which are decay products of uranium238, thorium232 and uranium235 respectively. All are found in the earth's crust. Solid elements, also radioactive, are produced by radon disintegration. Radon is classed as a rare gas in the periodic table of elements, along with helium, argon, neon, krypton and xenon. When disintegrating, radon emits alpha particles and generates solid decay products, which are also radioactive (polonium, bismuth, lead etc.). The potential danger of radon lies in its solid decay products rather than the gas itself. Whether or not they are attached aerosols, radon decay products can be inhaled and deposited in the bronchopulmonary tree to varying depths according to their size. Radon today is considered to be the main source of human exposure to natural radiation. At the international level, radon accounts for 52% of global average exposure to natural radiation. Isotope 222 (48%) is far more significant than isotope 220 (4%), whilst isotope 219 is considered as negligible. Exposure to radon varies considerably from one region to another, depending on factors such as weather conditions, and underlying geology. Activity concentration can therefore vary by a factor of 10 or even a 100 from one period of time to the next and from one area to another. There are many ways of measuring the radon 222 activity concentration and the potential alpha energy concentration of its short-lived decay products. Measuring techniques fall into three categories: - spot measurement methods; continuous measurement; integrated measurement. The proposed ISO (International Organisation for Standardisation) document suggests guidelines for measuring radon222 activity concentration and the potential alpha energy concentration of its short-lived decay products in a free (environment) and confined (buildings) atmosphere. The target date for availability of

  19. Intercepted photosynthetically active radiation estimated by spectral reflectance

    NASA Technical Reports Server (NTRS)

    Hatfield, J. L.; Asrar, G.; Kanemasu, E. T.

    1984-01-01

    Interception of photosynthetically active radiation (PAR) was evaluated relative to greenness and normalized difference (MSS (7-5)/(7+5) for five planting dates of wheat for 1978-79 and 1979-80 at Phoenix, Arizona. Intercepted PAR was calculated from leaf area index and stage of growth. Linear relatinships were found with greeness and normalized difference with separate relatinships describing growth and senescence of the crop. Normalized difference was significantly better than greenness for all planting dates. For the leaf area growth portion of the season the relation between PAR interception and normalized difference was the same over years and planting dates. For the leaf senescence phase the relationships showed more variability due to the lack of data on light interception in sparse and senescing canopies. Normalized difference could be used to estimate PAR interception throughout a growing season.

  20. Comparison of Martian Surface Radiation Predictions to the Measurements of Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)

    NASA Astrophysics Data System (ADS)

    Kim, M. H. Y.; Cucinotta, F.; Zeitlin, C. J.; Hassler, D.; Ehresmann, B.; Rafkin, S. C.; Wimmer-Schweingruber, R. F.; Böttcher, S. I.; Boehm, E.; Guo, J.; Kohler, J.; Martin-Garcia, C.; Reitz, G.; Posner, A.

    2014-12-01

    For the analysis of radiation risks to astronauts and planning exploratory space missions, detailed knowledge of particle spectra is an important factor. Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Mars Science Laboratory Radiation Assessment Detector (MSL-RAD) on the Curiosity rover since August 2012, and particle fluxes for a wide range of ion species (up to several hundred MeV/u) and high energy neutrons (8 - 1000 MeV) have been available for the first 200 sols. Although the data obtained on the surface of Mars for 200 sols are limited in the narrow energy spectra, the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code are compared to the data. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used, which includes direct knockout, evaporation and nuclear coalescence. Daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station are implemented into transport calculations for describing the daily column depth of atmosphere. Particles impinging on top of the Martian atmosphere reach the RAD after traversing varying depths of atmosphere that depend on the slant angles, and the model accounts for shielding of the RAD by the rest of the instrument. Calculations of stopping particle spectra are in good agreement with the RAD measurements for the first 200 sols by accounting changing heliospheric conditions and atmospheric pressure. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and thus increase the accuracy of the predictions of future radiation environments on Mars. These contributions lend support to the understanding of radiation health risks to

  1. Comparison of Martian Surface Radiation Predictions to the Measurements of Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.; Zeitlin, Cary; Hassler, Donald M.; Ehresmann, Bent; Rafkin, Scot C. R.; Wimmer-Schweingruber, Robert F; Boettcher, Stephan; Boehm, Eckart; Guo, Jingnan; Koehler, Jan; Martin, Cesar; Reitz, Guenther; Posner, Erik

    2014-01-01

    For the analysis of radiation risks to astronauts and planning exploratory space missions, detailed knowledge of particle spectra is an important factor. Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Mars Science Laboratory Radiation Assessment Detector (MSL-RAD) on the Curiosity rover since August 2012, and particle fluxes for a wide range of ion species (up to several hundred MeV/u) and high energy neutrons (8 - 1000 MeV) have been available for the first 200 sols. Although the data obtained on the surface of Mars for 200 sols are limited in the narrow energy spectra, the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code are compared to the data. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used, which includes direct knockout, evaporation and nuclear coalescence. Daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station are implemented into transport calculations for describing the daily column depth of atmosphere. Particles impinging on top of the Martian atmosphere reach the RAD after traversing varying depths of atmosphere that depend on the slant angles, and the model accounts for shielding of the RAD by the rest of the instrument. Calculations of stopping particle spectra are in good agreement with the RAD measurements for the first 200 sols by accounting changing heliospheric conditions and atmospheric pressure. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and thus increase the accuracy of the predictions of future radiation environments on Mars. These contributions lend support to the understanding of radiation health risks to

  2. Shortwave Radiative Closure Studies for Clear Skies During the Atmospheric Radiation Measurement 2003 Aerosol Intensive Observation Period

    SciTech Connect

    Michalsky, Joseph J.; Anderson, Gail; Barnard, James C.; Delamere, Jennifer; Gueymard, C.; Kato, Seiji; Kiedron, P.; McComiskey, A.; Ricchiazzi, P.

    2006-07-20

    The Department of Energy's Atmospheric Radiation Measurement (ARM) program sponsored a large aerosol intensive observation period (AIOP) to study aerosol during the month of May 2003 around the Southern Great Plains (SGP) Climate Research Facility (CRF) in north central Oklahoma. Redundant measurements of aerosol optical properties were made using different techniques at the surface as well as in vertical profile with sensors aboard two aircraft. One of the principal motivations for this experiment was to resolve the disagreement between models and measurements of diffuse horizontal broadband shortwave irradiance at the surface, especially for modest aerosol loading. This paper focuses on using the redundant aerosol and radiation measurements during this AIOP to compare direct beam and diffuse horizontal broadband shortwave irradiance measurements and models at the surface for a wide range of aerosol cases that occurred during 30 clear-sky periods on 13 days of May 2003. Models and measurements are compared over a large range of solar-zenith angles. Six different models are used to assess the relative agreement among them and the measurements. Better agreement than previously achieved appears to be the result of better specification of input parameters and better measurements of irradiances than in prior studies. Biases between modeled and measured direct irradiances are in the worst case 1%, and biases between modeled and measured diffuse irradiances are less than 1.9%.

  3. Simulation of a numerical filter for enhancing earth radiation budget measurements

    NASA Technical Reports Server (NTRS)

    Green, R. N.

    1981-01-01

    The Earth Radiation Budget Experiment has the objective to collect the radiation budget data which are needed to determine the radiation budget at the top of the atmosphere (TOA) on a regional scale. A second objective is to determine the accuracy of the results. Three satellites will carry wide and medium field of view radiometers which measure the longwave and shortwave components of radiation. Scanning radiometers will be included to detect small spatial features. A proposal has been made to employ for the nonscanning radiometers a one-dimensional numerical filter which reduces satellite measurements to TOA radiant excitances. The numerical filter was initially formulated by House (1980). It enhances the resolution of the radiation budget along the satellite groundtrack. The accuracy of the numerical filter estimate is studied by simulating the data gathering and measurement inversion process. The results of the study are discussed, taking into account two error sources.

  4. [Radiometers performance attenuation and data correction in long-term observation of total radiation and photosynthetically active radiation in typical forest ecosystems in China].

    PubMed

    Zhu, Zhi-Lin; Sun, Xiao-Min; Yu, Gui-Rui; Wen, Xue-Fa; Zhang, Yi-Ping; Han, Shi-Jie; Yan, Jun-Hua; Wang, Hui-Min

    2011-11-01

    Based on the total radiation and photosynthetically active radiation (PAR) observations with net radiometer (CNR1) and quantum sensor (Li-190SB) in 4 ChinaFLUX forest sites (Changbaishan, Qianyanzhou, Dinghushan, and Xishuangbanna) in 2003-2008, this paper analyzed the uncertainties and the radiometers performance changes in long-term and continuous field observation. The results showed that the 98% accuracy of the total radiation measured with CNR1 (Q(cNR1)) could satisfy the technical criterion for the sites except Xishuangbanna where the Q(CNR1) was averagely about 7% lower than Q(CM11), the radiation measured with high accuracy pyranometer CM11. For most sites, though the temperature had definite effects on the performance of CNR1, the effects were still within the allowable range of the accuracy of the instrument. Besides temperature, the seasonal fog often occurred in tropical rain forests in Xishuangbanna also had effects on the performance of CNR1. Based on the long-term variations of PAR, especially its ratio to total radiation in the 4 sites, it was found that quantum sensor (Li-190SB) had obvious performance attenuation, with the mean annual attenuation rate being about 4%. To correct the observation error caused by Li-190SB, an attempt was made to give a post-correction of the PAR observations, which could basically eliminate the quantum sensor's performance attenuation due to long-term field measurement.

  5. Evaluation of solar radiation measurement systems: EPRI/NREL final test report. Volume 1

    SciTech Connect

    Stoffel, T; Riordan, C; Bigger, J

    1992-11-01

    Measured solar radiation resource data are needed by electric utilities to evaluate the potential of renewable energy options like photovoltaics in their service territory. In this final test report, we document a cooperative project of the Electric Power Research Institute (EPRI) and the National Renewable Energy Laboratory (NREL) to compare available measurement system options for performing solar radiation resource assessments. We present the detailed results of a 6-month field comparison of thermopile-based pyranometer and pyrheliometer solar irradiance measurement systems with two different implementations of the rotating shadowband radiometer (RSR) concept installed at NREL`s Solar Radiation Research Laboratory (SRRL) in Golden, Colorado.

  6. Neutron and proton activation measurements from Skylab

    NASA Technical Reports Server (NTRS)

    Fishman, G. J.

    1974-01-01

    Radioactivity induced by high-energy protons and secondary neutrons (from nuclear interactions) in various samples returned from different locations in Skylab was measured directly by gamma-ray spectroscopy measurements of decay gamma rays from the samples. Incident fluxes were derived from the activation measurements, using known nuclear cross-section. Neutron and proton flux values were found to range from 0.2 to 5 particles/sq cm-sec, depending on the energy range and location in Skylab. The thermal neutron flux was less than 0.07 neutrons/sq cm-sec. The results are useful for data analysis and planning of future high-energy astronomy experiments.

  7. Radiation does from medical in-vivo prompt gamma-ray activation using a mobile nuclear reactor.

    PubMed

    Chung, C; Chen, C P; Chang, P S

    1988-10-01

    A method of medical diagnosis of toxic elements, using a neutron beam from a mobile nuclear reactor to perform partial-body in-vivo prompt gamma-ray activation technique, has been developed. Both neutron and gamma-ray dose equivalents in an irradiated phantom and around medical researchers were measured and evaluated. Neutron flux at various kinetic energies was measured using an activation foil technique, and the neutron dose equivalents at tissues of risk inside the irradiated phantom were calculated by neutron transport code. Gamma-ray dose equivalents inside the irradiated phantom and around the nuclear reactor were measured by thermoluminescent dosimeters. The risk associated with the neutron and gamma radiation dose equivalents received by both the irradiated phantom and medical researchers were evaluated in detail. The radiation safety of the in-vivo medical diagnosis using the mobile nuclear reactor, under the context of radiation protection guidelines, is discussed.

  8. Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

    NASA Astrophysics Data System (ADS)

    Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

    2016-06-01

    A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

  9. Atmospheric Radiation Measurement (ARM) Data from Point Reyes, California for the Marine Stratus, Radiation, Aerosol, and Drizzle (MASRAD) Project

    DOE Data Explorer

    Point Reyes National Seashore, on the California coast north of San Francisco, was the location of the first deployment of the DOE's Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF). The ARM Program collaborated with the U.S. Office of Naval Research and DOE's Aerosol Science Program in the Marine Stratus, Radiation, Aerosol, and Drizzle (MASRAD) project. Their objectives were to collect data from cloud/aerosol interactions and to improve understanding of cloud organization that is often associated with patches of drizzle. Between March and September 2005, the AMF and at least two research aircraft were used to collect data.

  10. Solar radiation measurements from coordinated radiosonde flights during the 20th March 2015 solar eclipse

    NASA Astrophysics Data System (ADS)

    Harrison, R. Giles; Marlton, Graeme; Williams, Paul; Nicoll, Keri

    2016-04-01

    Solar radiation sensors can be carried on standard weather balloon packages and provide additional information about the atmosphere's vertical structure beyond the traditional thermodynamic measurements [1]. An interesting set of circumstances for such sensors occurs during a solar eclipse, which provides a rapidly changing solar radiation environment within the duration of a typical free balloon flight. Coordinating several launches of solar radiation measuring radiosondes brings a good likelihood of at least one being above any cloud during the maximum eclipse, allowing solar eclipse radiation measurements for comparison with theory. For the 20th March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44N, 0.94W), Lerwick (60.15N, 1.13W) and Reykjavik (64.13N, 21.90W), straddling the path of the eclipse. All three balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. These approaches, which are essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes. [1] K.A. Nicoll and R.G. Harrison, Balloon-borne disposable radiometer Rev Sci Instrum 83, 025111 (2012) doi: 10.1063/1.3685252

  11. Personal reflections on the highlights and changes in radiation and radioisotope measurement applications

    NASA Astrophysics Data System (ADS)

    Gardner, Robin P.; Lee, Kyoung O.

    2015-11-01

    This paper describes the recent changes that the authors have perceived in the use of radiation and radioisotope measurement applications. The first change is that due to the increased use of Monte Carlo simulation which has occurred from a normal evolutionary process. This is due in large part to the increased accuracy that is being obtained by the use of detector response functions (DRFs) and the simultaneous increased computational efficiency that has become available with these DRFs, the availability of a greatly improved weight windows variance reduction method, and the availability of inexpensive computer clusters. This first change is a happy one. The other change that is occurring is in response to recent terrorist activities. That change is the replacement or major change in the use of long-lived radioisotopes in radioisotope measurement and other radioisotope source applications. In general this can be done by improving the security of these radioisotope sources or by replacing them altogether by using machine sources of radiation. In either case one would like to preclude altogether or at least minimize the possibility of terrorists being able to obtain radioisotopes and use them for clandestine purposes.

  12. Evaluating a three dimensional model of diffuse photosynthetically active radiation in maize canopies

    NASA Astrophysics Data System (ADS)

    Wang, Xiping; Guo, Yan; Li, Baoguo; Wang, Xiyong; Ma, Yuntao

    2006-07-01

    Diffuse photosynthetically active radiation (DPAR) is important during overcast days and for plant parts shaded from the direct beam radiation. Simulation of DPAR interception by individual plant parts of a canopy, separately from direct beam photosynthetically active radiation (PAR), may give important insights into plant ecology. This paper presents a model to simulate the interception of DPAR in plant canopies. A sub-model of a virtual maize canopy was reconstructed. Plant surfaces were represented as small triangular facets positioned according to three-dimensionally (3D) digitized data collected in the field. Then a second sub-model to simulate the 3D DPAR distribution in the canopy was developed by dividing the sky hemisphere into a grid of fine cells that allowed for the anisotropic distribution of DPAR over the sky hemisphere. This model, DSHP (Dividing Sky Hemisphere with Projecting), simulates which DSH (Divided Sky Hemisphere) cells are directly visible from a facet in the virtual canopy, i.e. not obscured by other facets. The DPAR reaching the center of a facet was calculated by summing the amounts of DPAR present in every DSH cell. The distribution of DPAR in a canopy was obtained from the calculated DPARs intercepted by all facets in the canopy. This DSHP model was validated against DPAR measurements made in an actual maize ( Zea mays L.) canopy over selected days during the early filling stage. The simulated and measured DPAR at different canopy depths showed a good agreement with a R 2 equaling 0.78 ( n=120).

  13. [Effect of the atmospheric ozone layer on the biologically active ultraviolet radiation on the earth's surface].

    PubMed

    Schulze, R; Kasten, F

    1975-08-01

    Based on measurements of the spectral irradiation intensity of UV-B global radiation by Bener (1960) and on the curve of spectral skin erythema effects newly measured by Urbach and Berger (1972), the biologically active UV-radiation at earth's surface has been calculated as a function of sun's altitude and atmospheric ozone content in so-called "Biological Units": BE = mWh cm-2 times erythema efficacy. On the basis of these data, the total daily, monthly, and yearly amounts of biologically active UV-radiation have been determined for the different geographical latitudes and various ozone contents. Approximately two thirds of BU hit the equatorial zone from 35 degrees south to 35 degrees north. Provided that the stratospheric ozone layer would be reduced by ten per cent from the exhaust gases of supersonic planes flying at high-altitude, an increase of BU would result amounting to 18% at the equator, to 19% in middle latitudes, and to 22% at the poles.

  14. Organic Aerosol Composition Measurements at the DOE Atmospheric Radiation Measurement Sites

    NASA Astrophysics Data System (ADS)

    Parworth, C. L.; Zhang, Q.; Fast, J. D.; Shippert, T.; Sivaraman, C.; Mei, F.; Tilp, A.

    2012-12-01

    Organic aerosol (OA) makes up a large portion of aerosols in the atmosphere. A better understanding of the chemical composition of OA is needed to quantify the effects that aerosols have on radiation and clouds. OA is composed of thousands of species making its chemical and physical properties difficult to characterize. The complex composition of OA can be decomposed into several factors representative of distinct sources and evolution processes through the application of Positive Matrix Factorization (PMF) on ambient OA data acquired with aerosol mass spectrometers (AMS). Previous studies have shown that the OA factors thus determined can be particularly useful for closure studies on aerosol optical and cloud condensation properties. Three units of Aerosol Chemical Speciation Monitor (ACSM) were recently added to two long-term measurement sites (Tropical Western Pacific and Southern Great Plains) and a mobile facility supported by the DOE ARM program. An ACSM is a smaller version of an AMS that provides long term, continuous measurements of aerosols and requires low maintenance. In this presentation, we will report the development of methods that take measurements of total organic matter and mass spectral information from the ACSM and derive OA factors. We will describe how the OA factors are derived, the quality assurance (QA) procedures, and comparisons of side-by-side measurements from AMS and ACSM instruments. The code generated in this analysis will be run within the Data Management Facility of ARM and the new data product called the Organic Aerosol Composition (Oacomp) value-added product will be added to the ARM archive. We will also present data from over a year-long period from the SGP site, along with an analysis that explains the seasonal and multi-day variations in inorganic and organic aerosol components.

  15. Measurement of radiation produced by ultra short laser pulses interacting with solid targets

    SciTech Connect

    Fonseca, C.; Fernandez, F.; Mendez, C.; Ruiz, C.; Roso, L.

    2010-04-26

    Ionizing radiation was produced when ultra-short laser pulses collided obliquely on solid aluminium targets. As a result of the interaction, electrons and photons of some tens of keV were measured. We also analyzed the effect of laser polarization on the emitted radiation.

  16. Application of the Pin Diode as a Dosimeter for Dose Measurement of Several Radiation Sources

    NASA Astrophysics Data System (ADS)

    Sopko, Vit; Dammer, Jiri; Chren, Dominik; Sopko, Bruno; Latal, Frantisek

    2010-04-01

    Experimental PIN diodes produced for measurement of low energy gamma radiation were exposed to neutron, proton and gamma radiation sources, in an attempt to expand the area of their application. Irradiation of the PIN diode resulted in changes of IV curve. The changes of voltage at certain current were recorded and depicted in graphs.

  17. DATABASE OF METEOROLOGICAL AND RADIATION MEASUREMENTS MADE IN BELARUS DURING THE FIRST THREE MONTHS FOLLOWING THE CHERNOBYL ACCIDENT

    PubMed Central

    Drozdovitch, Vladimir; Zhukova, Olga; Germenchuk, Maria; Khrutchinsky, Arkady; Kukhta, Tatiana; Luckyanov, Nickolas; Minenko, Victor; Podgaiskaya, Marina; Savkin, Mikhail; Vakulovsky, Sergey; Voillequé, Paul; Bouville, André

    2012-01-01

    Results of all available meteorological and radiation measurements that were performed in Belarus during the first three months after the Chernobyl accident were collected from various sources and incorporated into a single database. Meteorological information such as precipitation, wind speed and direction, and temperature in localities were obtained from meteorological station facilities. Radiation measurements include gamma-exposure rate in air, daily fallout, concentration of different radionuclides in soil, grass, cow’s milk and water as well as total beta-activity in cow’s milk. Considerable efforts were made to evaluate the reliability of the measurements that were collected. The electronic database can be searched according to type of measurement, date, and location. The main purpose of the database is to provide reliable data that can be used in the reconstruction of thyroid doses resulting from the Chernobyl accident. PMID:23103580

  18. Database of meteorological and radiation measurements made in Belarus during the first three months following the Chernobyl accident.

    PubMed

    Drozdovitch, Vladimir; Zhukova, Olga; Germenchuk, Maria; Khrutchinsky, Arkady; Kukhta, Tatiana; Luckyanov, Nickolas; Minenko, Victor; Podgaiskaya, Marina; Savkin, Mikhail; Vakulovsky, Sergey; Voillequé, Paul; Bouville, André

    2013-02-01

    Results of all available meteorological and radiation measurements that were performed in Belarus during the first three months after the Chernobyl accident were collected from various sources and incorporated into a single database. Meteorological information such as precipitation, wind speed and direction, and temperature in localities were obtained from meteorological station facilities. Radiation measurements include gamma-exposure rate in air, daily fallout, concentration of different radionuclides in soil, grass, cow's milk and water as well as total beta-activity in cow's milk. Considerable efforts were made to evaluate the reliability of the measurements that were collected. The electronic database can be searched according to type of measurement, date, and location. The main purpose of the database is to provide reliable data that can be used in the reconstruction of thyroid doses resulting from the Chernobyl accident.

  19. Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy

    NASA Astrophysics Data System (ADS)

    Hälg, R. A.; Besserer, J.; Boschung, M.; Mayer, S.; Lomax, A. J.; Schneider, U.

    2014-05-01

    In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

  20. Atmospheric Radiation Measurement Program facilities newsletter, February 2001.

    SciTech Connect

    Holdridge, D. J.

    2001-03-08

    This newsletter consists of the following: (1) ARM Science Team Meeting Scheduled--The 11th Annual ARM Science Team meeting is scheduled for March 19-23, 2001, in Atlanta, Georgia. Members of the science team will exchange research results achieved by using ARM data. The science team is composed of working groups that investigate four topics: instantaneous radiative flux, cloud parameterizations and modeling, cloud properties, and aerosols. The annual meeting brings together the science team's 150 members to discuss issues related to ARM and its research. The members represent universities, government laboratories and research facilities, and independent research companies. (2) Communications to Extended Facilities Upgraded--New communications equipment has been installed at all of the SGP extended facilities. Shelters were installed to house the new equipment used to transfer data from instruments via the Internet to the site data system at the central facility. This upgrade has improved data availability from the extended facilities to 100% and reduced telephone costs greatly. (3) SGP Goes ''Buggy''--Steve Sekelsky, a researcher from the University of Massachusetts, is planning to bring a 95-GHz radar to the SGP central facility for deployment in March-October 2001. The radar will help to identify signals due to insects flying in the air. The ARM millimeter cloud radar, which operates at 35 GHz, is sensitive to such insect interference. Testing will also be performed by using a second 35-GHz radar with a polarized radar beam, which can differentiate signals from insects versus cloud droplets. (4) Winter Fog--Fog can add to hazards already associated with winter weather. Common types of fog formation include advection, radiation, and steam. Advection fog: An advection fog is a dense fog that forms when a warm, moist air mass moves into an area with cooler ground below. For example, fog can form in winter when warmer, water-saturated air from the south (associated

  1. The Vertical Distribution of Aerosols Over the Atmospheric Radiation Measurement Southern Great Plains Site Measured versus Modeled

    SciTech Connect

    Ferrare, R.; Turner, D.D.; Clayton, M.; Guibert, S.; Schulz, M.; Chin, M.

    2005-03-18

    Aerosol extinction profiles measured by the Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility Raman lidar are used to evaluate aerosol extinction profiles and aerosol optical thickness (AOT) simulated by aerosol models as part of the Aerosol module inter- Comparison in global models (AEROCOM) project. This project seeks to diagnose aerosol modules of global models and subsequently identify and eliminate weak components in aerosol modules used for global modeling; AEROCOM activities also include assembling data sets to be used in the evaluations. The AEROCOM average aerosol extinction profiles typically show good agreement with the Raman lidar profiles for altitudes above about 2 km; below 2 km the average model profiles are significantly (30-50%) lower than the Raman lidar profiles. The vertical variability in the average aerosol extinction profiles simulated by these models is less than the variability in the corresponding Raman lidar pro files. The measurements also show a much larger diurnal variability than the Interaction with Chemistry and Aerosols (INCA) model, particularly near the surface where there is a high correlation between aerosol extinction and relative humidity.

  2. Noninvasive ambulatory measurement system of cardiac activity.

    PubMed

    Pino, Esteban J; Chavez, Javier A P; Aqueveque, Pablo

    2015-08-01

    This work implements a noninvasive system that measures the movements caused by cardiac activity. It uses unobtrusive Electro-Mechanical Films (EMFi) on the seat and on the backrest of a regular chair. The system detects ballistocardiogram (BCG) and respiration movements. Real data was obtained from 54 volunteers. 19 of them were measured in the laboratory and 35 in a hospital waiting room. Using a BIOPAC acquisition system, the ECG was measured simultaneously to the BCG for comparison. Wavelet Transform (WT) is a better option than Empirical Mode Decomposition (EMD) for signal extraction and produces higher effective measurement time. In the laboratory, the best results are obtained on the seat. The correlation index was 0.9800 and the Bland-Altman limits of agreement were 0.7136 ± 4.3673 [BPM]. In the hospital waiting room, the best results are also from the seat sensor. The correlation index was 0.9840, and the limits of agreement were 0.4386 ± 3.5884 [BPM]. The system is able to measure BCG in an unobtrusive way and determine the cardiac frequency with high precision. It is simple to use, which means the system can easily be used in non-standard settings: resting in a chair or couch, at the gym, schools or in a hospital waiting room, as shown. PMID:26738057

  3. [Solar activity, dynamics of the ozone layer and possible role of ultraviolet radiation in heliobiology].

    PubMed

    Vladimirskiĭ, B M

    1982-01-01

    Solar activity influences the ozonosphere thickness, thus changing the intensity of the near-Earth ultraviolet radiation in the B band. In certain regions the radiation may change by 10--15%, with solar activity varying from its maximum to minimum. The variations in the ultraviolet intensity are very likely to be environmentally important. Thus, solar ultraviolet radiation at lambda = 290 -- 340 nm acts as one more physical agent transferring the effect of solar activity into the biosphere.

  4. Raman distributed temperature measurement at CERN high energy accelerator mixed field radiation test facility (CHARM)

    NASA Astrophysics Data System (ADS)

    Toccafondo, Iacopo; Nannipieri, Tiziano; Signorini, Alessandro; Guillermain, Elisa; Kuhnhenn, Jochen; Brugger, Markus; Di Pasquale, Fabrizio

    2015-09-01

    In this paper we present a validation of distributed Raman temperature sensing (RDTS) at the CERN high energy accelerator mixed field radiation test facility (CHARM), newly developed in order to qualify electronics for the challenging radiation environment of accelerators and connected high energy physics experiments. By investigating the effect of wavelength dependent radiation induced absorption (RIA) on the Raman Stokes and anti-Stokes light components in radiation tolerant Ge-doped multi-mode (MM) graded-index optical fibers, we demonstrate that Raman DTS used in loop configuration is robust to harsh environments in which the fiber is exposed to a mixed radiation field. The temperature profiles measured on commercial Ge-doped optical fibers is fully reliable and therefore, can be used to correct the RIA temperature dependence in distributed radiation sensing systems based on P-doped optical fibers.

  5. Measurements of the spectrum and energy dependence of X-ray transition radiation

    NASA Technical Reports Server (NTRS)

    Cherry, M. L.

    1978-01-01

    The results of experiments designed to test the theory of X-ray transition radiation and to verify the predicted dependence of the characteristic features of the radiation on the radiator dimensions are presented. The X-ray frequency spectrum produced by 5- to 9-GeV electrons over the range 4 to 30 keV was measured with a calibrated single-crystal Bragg spectrometer, and at frequencies up to 100 keV with an NaI scintillator. The interference pattern in the spectrum and the hardening of the radiation with increasing foil thickness are clearly observed. The energy dependence of the total transition-radiation intensity was studied using a radiator with large dimensions designed to yield energy-dependent signals at very high particle energies, up to E/mc-squared approximately equal to 100,000. The results are in good agreement with the theoretical predictions.

  6. Radiative properties measurements of photoionized plasmas on Z

    NASA Astrophysics Data System (ADS)

    Loisel, Guillaume; Bailey, Jim; Nagayama, Taisuke; Hansen, Stephanie; Rochau, Greg; Liedahl, Duane; Fontes, Chris; Flaugh, Matt; Koepke, Mark; Lane, Ted; Mancini, Roberto

    2015-11-01

    Physical descriptions of accretion-powered objects such as black holes, x-ray binaries, or AGN are informed through the interpretation of emergent spectra from the photoionized plasmas that surround them. Line formation in photoionized plasmas is dependent on the details of the radiation transport treatment and the so-called Resonant Auger Destruction hypothesis typically required to interpret the relativistically broadened Fe K α emitted from near the black hole event horizon. The Z facility at Sandia National Laboratories can produced such photoionized plasmas producing 1.6MJ of x-rays from the z-pinch dynamic hohlraum. The extended suite of diagnostics allows for a detailed characterization of plasmas conditions through absorption spectroscopy. present accurate and high-resolution emergent intensity observed from a photoionized silicon plasma for a discrete set of column densities that will help us evaluate understanding for radiation transport in accretion powered objects. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  7. Radiative Energetics of Mineral Dust Aerosols from Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee; Hansell, Richard A.

    2011-01-01

    Airborne dust aerosols worldwide contribute a significant part to air quality problems and, to some extent, regional climatic issues (e.g., radiative forcing, hydrological cycle, and primary biological productivity in oceans). Evaluating the direct solar radiative effect of dust aerosols is relatively straightforward due in part to the relatively large SIN ratio in broadband irradiance measurements. The longwave (LW) impact, on the other hand, is rather difficult to ascertain since the measured dust signal level (approx.10 W/sq m) is on the same order as the instrumental uncertainties. Although the magnitude of the LW impact is much smaller than that of the shortwave (SW), it can still have a noticeable influence on the energy distribution of Earth-atmosphere system, particularly due to the strong light-absorptive properties commonly found in many terrestrial minerals. The current effort is part of an ongoing research study to perform a global assessment of dust direct aerosol radiative effects (DARE) during major field deployments of key dust source regions worldwide. In this work we present results stemming from two previous field deployments: the 2006 NASA African Monsoon Multidisciplinary Activities and the 2008 Asian Monsoon Years, both utilizing NASA Goddard's mobile ground-based facility. The former study focused on transported Saharan dust at Sal (16.73degN, 22.93degW), Cape Verde along the west coast of Africa while the latter focused on Asian dust at Zhangye (39.082degN, 100.276degE), China near the source between the Taklimakan and Gobi deserts. Due to the compelling variability in spatial and temporal scale of dust properties during field experiments, a deterministic I-D radiative transfer model constrained by local measurements (i.e., spectral photometry/interferometry and lidar for physical/microphysical, mineralogy, and single-scattering properties) is employed to evaluate dust's local instantaneous SW/LW DARE both at the surface and at the top of

  8. Measurements of Radiation Exposure on Commercial Aircraft with the LIULIN-3M Instrument

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, E. G.; Stauffer, C. A.; Dachev, T. P.; Brucker, G. J.; Tomov, B. T.; Dimitrov, P. G.

    1998-01-01

    This paper reports on the development of a compact radiation monitor/dosimeter, the LIULIN-3M, and on extended measurements conducted on the ground and on commercial aircraft on domestic and international flights.

  9. [Evaluation of uncertainty in measurement of radiated disturbance and analysis of the result].

    PubMed

    Wang, Weiming; Jiang, Sui

    2012-03-01

    This paper evaluates the uncertainty in the measurement of radiated disturbance by analyzing and calculating the components that influence the uncertainty. And the effectiveness of the uncertainty testing has been confirmed through the ability validation.

  10. Scientific system for high-resolution measurement of the circumsolar radiation

    NASA Astrophysics Data System (ADS)

    Schrott, Simeon; Schmidt, Thomas; Hornung, Thorsten; Nitz, Peter

    2014-09-01

    We developed a camera based system for measurements of the circumsolar radiation with a high angular resolution of 0.1 mrad. Subsequent measurements may be taken at intervals as short as 15 s. In this publication we describe the optical system in detail and discuss some aspects of the measurement method. First results from two days of measurement at Freiburg i. Br., Germany, are presented and compared to data from literature. The good results encourage us to perform longer measurement campaigns in future to better understand the influence of circumsolar radiation on the power yield of concentrating photovoltaic systems.

  11. The Physical Measurement of Radiation Damage to Coliphage T7 DNA

    PubMed Central

    Hawkins, R. B.; Ginsberg, D. M.

    1971-01-01

    Coliphage T7 was exposed to 60Co gamma radiation while suspended in phosphate buffer or in phosphate buffer plus 0.001 M l-histidine. DNA was isolated from the phage by incubation with pronase, followed by extraction with cold phenol. The intrinsic viscosity of the DNA was measured as a function of radiation dose. The fraction of DNA molecules surviving radiation treatment with no double-strand breaks was measured from the radiation-induced heterogeneity of the DNA sedimentation boundary. From comparison of these measurements it is concluded that radiation introduces lesions other than double-strand breaks which affect the hydrodynamic properties of the DNA. In both buffer and buffer plus histidine the surviving fraction of intact virus genomes far exceeds the surviving fraction of plaque-forming units at any given dose. It was found that the decrease in intrinsic viscosity with dose is independent of the presence of histidine in the radiation medium. From this it is concluded that DNA damage is primarily due to a direct effect of radiation on the phage particle. The procedure necessary to isolate DNA from irradiated virus suggests that radiation produces covalent bonding of protein to the DNA. PMID:5579144

  12. Stanford Synchrotron Radiation Laboratory. Activity report for 1988

    SciTech Connect

    Cantwell, K.

    1996-01-01

    For SSRL operations, 1988 was a year of stark contrasts. The first extended PEP parasitic running since the construction of our two beam lines on that storage ring took place in November and December. Four experiments discussed below, were performed and detailed operational procedures which allowed synchrotron radiation an high energy users to coexist were established. SSRL anticipates that there will be significant amounts of beam time when PEP is run again for high energy physics. On the other hand, activity on SPEAR consisted of brief parasitic running on the VUV lines in December when the ring was operated at 1.85 GeV for colliding beam experiments. There was no dedicated SPEAR running throughout the entire calendar year. This is the first time since dedicated SPEAR operation was initiated in 1980 that there was no such running. The decision was motivated by both cost and performance factors, as discussed in Section 1 of this report. Fortunately, SLAC and SSRL have reached an agreement on SPEAR and PEP dedicated time charges which eliminates the cost volatility which was so important in the cancellation of the June-July dedicated SPEAR run. As discussed in Section 2, the 3 GeV SPEAR injector construction is proceeding on budget and on schedule. The injector will overcome the difficulties associated with the SLC-era constraint of only two injections per day. SSR and SLAC have also embarked on a program to upgrade SPEAR to achieve high reliability and performance. As a consequence, SSRL`s users may anticipate a highly effective SPEAR by 1991, at the latest. At that time, SPEAR is expected to be fully dedicated to synchrotron radiation research and operated by SSRL. Also contained in this report is a discussion of the improvements to SSRL`s experimental facilities and highlights of the experiments of the past year.

  13. A Terahertz Blackbody Radiation Standard Based on Emissivity Measurements and a Monte-Carlo Simulation

    NASA Astrophysics Data System (ADS)

    Monte, C.; Gutschwager, B.; Adibekyan, A.; Hollandt, J.

    2014-08-01

    Blackbody radiators are commonly used metrological standards of spectral radiance and radiation temperature according to Planck's law of thermal radiation. In a well defined geometry of observation they also provide calculable irradiance for the calibration of radiation detectors. Here we describe the metrological characterization of a vacuum variable-temperature blackbody to serve as a source standard for FIR- and THz radiation from 5 μm to 200 μm (60 THz to 1.5 THz). The key quantity of the characterization is the effective spectral emissivity of its cavity. This is determined by angular resolved directional spectral emissivity and directional spectral reflectivity measurements of its wall coating, Aeroglaze Z306. From the reflectivity measurements the diffusity is determined. Spectral emissivity and diffusity in combination with the well known cavity geometry allow the determination of the effective spectral cavity emissivity via a Monte-Carlo ray tracing simulation.

  14. Spectral Signature of Column Solar Radiation Absorption During the Atmospheric Radiation Measurement Enhanced Shortwave Experiment (ARESE). Revision

    SciTech Connect

    O'Hirok, William; Gautier, Catherine; Ricchiazzi, Paul

    1999-11-01

    Spectral and broadband shortwave radiative flux data obtained from the Atmospheric Radiation Measurement Enhanced Shortwave Experiment (ARESE) are compared with 3-D radiative transfer computations for the cloud field of October 30, 1995. Because the absorption of broadband solar radiation in the cloudy atmosphere deduced from observations and modeled differ by 135 Wm{sup -2}, we performed a consistency analysis using spectral observations and the model to integrate for wavelengths between the spectral observations. To match spectral measurements, aerosols need a reduction in both single scattering albedo (from 0.938 to 0.82) and asymmetry factor (from 0.67 to 0.61), and cloud droplets require a three-fold increase in co-albedo. Even after modifying the model inputs and microphysics the difference in total broadband absorption is still of the order of 75Wm{sup -2}. Finally, an unexplained absorber centered around 1.06 {micro}m appears in the comparison that is much too large to be explained by dimers.

  15. Atmospheric radiation measurement program facilities newsletter, August 2001.

    SciTech Connect

    Holdridge, D. J.,ed.

    2001-09-04

    Summer 2001 Heat Wave--This summer has proved to be downright hot in the Southern Great Plains states. The temperatures soared to record-setting levels. The state of Oklahoma saw its fourth hottest July since 1895, while Kansas experienced its seventh warmest. The average temperature throughout most of Oklahoma for the month of July was 2.5-5.5 F above normal. The highest temperature recorded in the region during July was 107 F in Oklahoma City. Wichita, Kansas, had 17 July days with recorded temperatures of 100 F or above, while Medicine Lodge, Kansas, had 21. In addition, Oklahoma suffered its ninth driest July, with precipitation levels much below normal. Kansas fared better, receiving above-normal precipitation amounts. Nevertheless, regional July rainfall averaged 1.5-3.0 inches below normal. Not only is a summer heat wave uncomfortable, but it can also be dangerous. The National Weather Service (NWS) has increased efforts to alert the public to the hazards of heat waves. Prolonged excessive heat and humidity stress the human body and can, in some cases, cause death. The NWS has devised a heat index that is a measure of the heat we perceive as a function of air temperature and humidity. A heat index chart displays different zones from caution to extreme danger, much like a wind chill index chart used in the winter. The values represent conditions of light winds and shade. Thus, in full sunshine heat index values can increase by 15 F. Exposure to winds in hot, dry weather can be equally dangerous. The NWS sends out alerts when the heat index is expected to reach values with significant potential impact. The danger of heat-related illness increases with the number of consecutive days with high heat and humidity levels. Heat and humidity take their toll faster on the elderly, small children, and those with respiratory health problems. Heat-related illnesses come in several forms with different symptoms. From common sunburns to heat stroke, these heat disorders

  16. Measuring and modeling near-surface reflected and emitted radiation fluxes at the FIFE site

    NASA Technical Reports Server (NTRS)

    Blad, Blaine L.; Walter-Shea, Elizabeth A.; Starks, Patrick J.; Vining, Roel C.; Hays, Cynthia J.; Mesarch, Mark A.

    1990-01-01

    Information is presented pertaining to the measurement and estimation of reflected and emitted components of the radiation balance. Information is included about reflectance and transmittance of solar radiation from and through the leaves of some grass and forb prairie species, bidirectional reflectance from a prairie canopy is discussed and measured and estimated fluxes are described of incoming and outgoing longwave and shortwave radiation. Results of the study showed only very small differences in reflectances and transmittances for the adaxial and abaxial surfaces of grass species in the visible and infrared wavebands, but some differences in the infrared wavebands were noted for the forbs. Reflectance from the prairie canopy changed as a function of solar and view zenith angles in the solar principal plane with definite asymmetry about nadir. The surface temperature of prairie canopies was found to vary by as much as 5 C depending on view zenith and azimuth position and on the solar azimuth. Aerodynamic temperature calculated from measured sensible heat fluxes ranged from 0 to 3 C higher than nadir-viewed temperatures. Models were developed to estimate incoming and reflected shortwave radiation from data collected with a Barnes Modular Multiband Radiometer. Several algorithms for estimating incoming longwave radiation were evaluated and compared to actual measures of that parameter. Net radiation was calculated using the estimated components of the shortwave radiation streams, determined from the algorithms developed, and from the longwave radiation streams provided by the Brunt, modified Deacon, and the Stefan-Boltzmann models. Estimates of net radiation were compared to measured values and found to be within the measurement error of the net radiometers used in the study.

  17. Photosynthetically active radiation and comparison of methods for its estimation in equatorial Singapore

    NASA Astrophysics Data System (ADS)

    Tan, Puay Yok; Ismail, Mirza Rifqi Bin

    2016-02-01

    Photosynthetically active radiation (PAR) is an important input variable for urban climate, crop modelling and ecosystem services studies. Despite its importance, only a few empirical studies have been conducted on PAR, its relationship to global solar radiation and sky conditions and its estimation in the tropics. We report in this study, the characterisation of PAR in Singapore through direct measurements and development of models for its estimation using input variables of global solar radiation ( H), photometric radiation ( L), clearness index ( k t ) and sky view factor (SVF). Daily PAR showed a good correlation with daily H and had a comparatively small seasonal variation in PAR due to Singapore's equatorial position. The ratio of PAR to H ( PAR/ H) showed a slight depression in midyear from May to August, which correlated well with seasonal patterns in rainfall over the study period. Hourly PAR/ H increased throughout the day. Three empirical models developed in this study were able to predict daily PAR satisfactorily, with the most accurate model being one which included both H and k t as independent variables. A regression model for estimation of PAR under shaded conditions using SVF produced satisfactory estimation of daily PAR but was prone to high mean percentage error at low PAR levels.

  18. History of satellite missions and measurements of the Earth Radiation Budget (1957-1984)

    NASA Technical Reports Server (NTRS)

    House, F. B.; Gruber, A.; Hunt, G. E.; Mecherikunnel, A. T.

    1986-01-01

    The history of satellite missions and their measurements of the earth radiation budget from the beginning of the space age until the present time are reviewed. The survey emphasizes the early struggle to develop instrument systems to monitor reflected shortwave and emitted long-wave exitances from the earth, and the problems associated with the interpretation of these observations from space. In some instances, valuable data sets were developed from satellite measurements whose instruments were not specifically designed for earth radiation budget observations.

  19. Nuclear Targets for a Precision Measurement of the Neutral Pion Radiative Width

    SciTech Connect

    Martel, Philippe; Clinton, Eric; McWilliams, R.; Lawrence, Dave; Miskimen, Rory; Ahmidouch, Abdellah; Ambrozewicz, Pawel; Asaturyan, Arshak; Baker, O.; Benton, LaRay; Bernstein, Aron; Cole, Philip; Collins, Patrick; Dale, Daniel; Danagoulian, Samuel; Davidenko, G.; Demirchyan, Raphael; Deur, Alexandre; DOLGOLENKO, A.; Dzyubenko, Georgiy; Evdokimov, Anatoly; Feng, JIng; Gabrielyan, Marianna; Gan, Liping; Gasparian, Ashot; Glamazdin, Oleksandr; Goryachev, Vladimir; Gyurjyan, Vardan; Hardy, K.; Ito, Mark; Khandaker, Mahbubul; Kingsberry, Paul; Kolarkar, Ameya; Konchatnyi, Mykhailo; Korchin, O.; Korsch, Wolfgang; Kowalski, Stanley; Kubantsev, Mikhail; Kubarovsky, Valery; LARIN, Ilya; MATVEEV, V.; McNulty, Dustin; Milbrath, Brian; Minehart, Ralph; Mochalov, Vasiliy; Mtingwa, Sekazi; Nakagawa, Itaru; Overby, Steven; Pasyuk, Evgueni; Payen, Marvin; Pedroni, Ronald; Prok, Yelena; Ritchie, Barry; Salgado, Carlos; Sitnikov, Anatoly; Sober, Daniel; Stephens, W.; Teymurazyan, Aram; Underwood, Jarreas; VASILIEV, A.; VEREBRYUSOV, V.; Vishnyakov, Vladimir; Wood, Michael

    2009-12-01

    A technique is presented for precision measurements of the area densities, density * T, of approximately 5% radiation length carbon and 208Pb targets used in an experiment at Jefferson Laboratory to measure the neutral pion radiative width. The precision obtained in the area density for the carbon target is +/- 0.050%, and that obtained for the lead target through an x-ray attenuation technique is +/- 0.43%.

  20. Atmospheric Radiation Measurement program facilities newsletter, May 2002.

    SciTech Connect

    Holdridge, D. J.

    2002-06-03

    Eight eddy correlation (ECOR) flux measurement systems are now deployed throughout the ARM SGP CART site. These systems are used to determine the flux (flow) of sensible heat, the flux of latent heat, and air momentum just above cropland a few hundred feet upwind of the ECOR locations. Sensible heat is energy we feel as warmth. Latent heat is the energy that evaporated water vapor measured in the atmosphere. The ECOR systems actually measure wind velocity and temperature fluctuations, water vapor, and barometric pressure. The surface flux values for sensible heat, latent heat, and momentum are calculated from these measurements.

  1. Saharan Dust Aerosol Radiative Forcing Measured from Space.

    NASA Astrophysics Data System (ADS)

    Li, F.; Vogelmann, A. M.; Ramanathan, V.

    2004-07-01

    This study uses data collected from the Clouds and the Earth's Radiant Energy System (CERES) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments to determine Saharan dust broadband shortwave aerosol radiative forcing over the Atlantic Ocean near the African coast (15° 25°N, 45° 15°W). The clear-sky aerosol forcing is derived directly from these data, without requiring detailed information about the aerosol properties that are not routinely observed such as chemical composition, microphysical properties, and their height variations. To determine the diurnally averaged Saharan dust radiative forcing efficiency (i.e., broadband shortwave forcing per unit optical depth at 550 nm, W m-2 τ-1a), two extreme seasons are juxtaposed: the high-dust months [June August (JJA)] and the low-dust months [November January (NDJ)]. It is found that the top-of-atmosphere (TOA) diurnal mean forcing efficiency is -35 ± 3 W m-2 τ-1a for JJA, and -26 ± 3 W m-2 τ-1a for NDJ. These efficiencies can be fit by reducing the spectrally varying aerosol single-scattering albedo such that its value at 550 nm is reduced from 0.95 ± 0.04 for JJA to about 0.86 ± 0.04 for NDJ. The lower value for the low-dust months might be influenced by biomass-burning aerosols that were transported into the study region from equatorial Africa. Although the high-dust season has a greater (absolute value of the) TOA forcing efficiency, the low-dust season may have a greater surface forcing efficiency. Extrapolations based on model calculations suggest the surface forcing efficiencies to be about -65 W m-2 τ-1a for the high-dust season versus -81 W m-2 τ-1a for the low-dust season. These observations indicate that the aerosol character within a region can be readily modified, even immediately adjacent to a powerful source region such as the Sahara. This study provides important observational constraints for models of dust radiative forcing.


  2. Active control of sound transmission/radiation from elastic plates by vibration inputs. II - Experiments

    NASA Technical Reports Server (NTRS)

    Metcalf, V. L.; Fuller, C. R.; Silcox, R. J.; Brown, D. E.

    1992-01-01

    Actively controlled harmonic force inputs were applied experimentally to reduce the sound transmitted through an elastic circular plate. The control implementation used a time domain least mean square adaptive algorithm with two error sensors. The control forces were applied directly to the plate by point force vibration inputs, while the error information and performance were measured in the radiated acoustic field by microphones. Test cases were also performed in which the error sensors were accelerometers mounted on the plate. When accelerometers were used as error sensors, the controller performance was degraded; leading to the conclusion that minimizing plate motion does not necessarily lead to an associated decrease in radiated sound levels. In contrast, the results show excellent attenuation of the transmitted sound field when microphone error sensors were used. This result was consistent over a range of frequencies. In addition, the experimental results are compared to previously derived analytical results and the effect of using a point or global minimization scheme is discussed.

  3. Cerium-activated sol-gel silica glasses for radiation dosimetry in harsh environment

    NASA Astrophysics Data System (ADS)

    El Hamzaoui, Hicham; Capoen, Bruno; Helou, Nissrine Al; Bouwmans, Géraud; Ouerdane, Youcef; Boukenter, Aziz; Girard, Sylvain; Marcandella, Claude; Duhamel, Olivier; Chadeyron, Geneviève; Mahiou, Rachid; Bouazaoui, Mohamed

    2016-04-01

    Cerium-doped silica glass has been prepared for ionizing radiation dosimetry applications, using the sol-gel route and densification under different atmospheres. In comparison with the glass densified under air atmosphere, the one obtained after sintering the xerogel under helium gas presents improved optical properties, with an enhancement of the photoluminescence quantum yield up to 33%, which is attributed to a higher Ce3+ ions concentration. Such a glassy rod has been jacketed in a quartz tube and then drawn at high temperature to a cane, which has been used as active material in a fibered remote x-ray radiation dosimeter. The sample exhibited a reversible linear radioluminescence intensity response versus the dose rate up to 30 Gy s-1. These results confirm the potentialities of this material for in vivo or high rate dose remote dosimetry measurements.

  4. Determining the radon exhalation rate from a gold mine tailings dump by measuring the gamma radiation.

    PubMed

    Ongori, Joash N; Lindsay, Robert; Newman, Richard T; Maleka, Peane P

    2015-02-01

    The mining activities taking place in Gauteng province, South Africa have caused millions of tons of rocks to be taken from underground to be milled and processed to extract gold. The uranium bearing tailings are placed in an estimated 250 dumps covering a total area of about 7000 ha. These tailings dumps contain considerable amounts of radium and have therefore been identified as large sources of radon. The size of these dumps make traditional radon exhalation measurements time consuming and it is difficult to get representative measurements for the whole dump. In this work radon exhalation measurements from the non-operational Kloof mine dump have been performed by measuring the gamma radiation from the dump fairly accurately over an area of more than 1 km(2). Radon exhalation from the mine dump have been inferred from this by laboratory-based and in-situ gamma measurements. Thirty four soil samples were collected at depths of 30 cm and 50 cm. The weighted average activity concentrations in the soil samples were 308 ± 7 Bq kg(-1), 255 ± 5 Bq kg(-1) and 18 ± 1 Bq kg(-1) for (238)U, (40)K and (232)Th, respectively. The MEDUSA (Multi-Element Detector for Underwater Sediment Activity) γ-ray detection system was used for field measurements. The radium concentrations were then used with soil parameters to obtain the radon flux using different approaches such as the IAEA (International Atomic Energy Agency) formula. Another technique the MEDUSA Laboratory Technique (MELT) was developed to map radon exhalation based on (1) recognising that radon exhalation does not affect (40)K and (232)Th activity concentrations and (2) that the ratio of the activity concentration of the field (MEDUSA) to the laboratory (HPGe) for (238)U and (40)K or (238)U and (232)Th will give a measure of the radon exhalation at a particular location in the dump. The average, normalised radon flux was found to be 0.12 ± 0.02 Bq m(-2) s(-1) for the mine dump. PMID:25461511

  5. Determining the radon exhalation rate from a gold mine tailings dump by measuring the gamma radiation.

    PubMed

    Ongori, Joash N; Lindsay, Robert; Newman, Richard T; Maleka, Peane P

    2015-02-01

    The mining activities taking place in Gauteng province, South Africa have caused millions of tons of rocks to be taken from underground to be milled and processed to extract gold. The uranium bearing tailings are placed in an estimated 250 dumps covering a total area of about 7000 ha. These tailings dumps contain considerable amounts of radium and have therefore been identified as large sources of radon. The size of these dumps make traditional radon exhalation measurements time consuming and it is difficult to get representative measurements for the whole dump. In this work radon exhalation measurements from the non-operational Kloof mine dump have been performed by measuring the gamma radiation from the dump fairly accurately over an area of more than 1 km(2). Radon exhalation from the mine dump have been inferred from this by laboratory-based and in-situ gamma measurements. Thirty four soil samples were collected at depths of 30 cm and 50 cm. The weighted average activity concentrations in the soil samples were 308 ± 7 Bq kg(-1), 255 ± 5 Bq kg(-1) and 18 ± 1 Bq kg(-1) for (238)U, (40)K and (232)Th, respectively. The MEDUSA (Multi-Element Detector for Underwater Sediment Activity) γ-ray detection system was used for field measurements. The radium concentrations were then used with soil parameters to obtain the radon flux using different approaches such as the IAEA (International Atomic Energy Agency) formula. Another technique the MEDUSA Laboratory Technique (MELT) was developed to map radon exhalation based on (1) recognising that radon exhalation does not affect (40)K and (232)Th activity concentrations and (2) that the ratio of the activity concentration of the field (MEDUSA) to the laboratory (HPGe) for (238)U and (40)K or (238)U and (232)Th will give a measure of the radon exhalation at a particular location in the dump. The average, normalised radon flux was found to be 0.12 ± 0.02 Bq m(-2) s(-1) for the mine dump.

  6. Youth solar ultraviolet radiation exposure, concurrent activities and sun-protective practices: a review.

    PubMed

    Wright, C Y; Reeder, A I

    2005-01-01

    To assist standardization of procedures, facilitate comparisons, and help guide research efforts to optimally inform development of appropriately targeted interventions, there is a need to review methods used to quantify child and adolescent solar ultraviolet radiation (UV) exposure, related outdoor activities and sun-protective practices. This holistic approach is essential for comprehensive research that will provide all-inclusive, informative and meaningful messages for preventive measures of harmful UV exposure. Two databases were searched and 29 studies were retrieved, and these studies report measurement or assessment techniques documenting UV exposure patterns and related outdoor activities. Polysulfone film badges were the main measurement instrument used in 10 studies, with questionnaire, survey data, observation, a model, electronic dosimeters, biological dosimeters, colorimeter and UV colouring labels used in the remaining studies. Methods used to record activities included self-report, parental report, a logbook and observation. Measurement duration and unit of UV exposure varied in most studies, but a method common to 15 studies was measured UV exposure as a percentage of ambient UV. The studies reviewed do not provide sufficient information for the development and evaluation of targeted youth sun protection programs. Studies are required which document precise UV exposure, concurrent activities and sun protection usage for children and adolescents. PMID:16354111

  7. Diagnostics of the efficiency of surface plasmon-polariton excitation by quantum dots via polarization measurements of the output radiation

    SciTech Connect

    Kukushkin, V. A.; Baidus, N. V.; Zdoroveishchev, A. V.

    2015-06-15

    It is demonstrated that the efficiency of surface plasmon-polariton excitation at a metal-semiconductor interface by active quantum dots can be determined from measurements of the polarization characteristics of the output radiation. Experimentally, the proposed diagnostic method is based on finding the ratio of the intensities of the output radiation with polarizations orthogonal and parallel to the nanoheterostructure plane for two different distances between the quantum-dot layer and the metal-semiconductor interface. These data are then used to obtain the unknown parameters in the proposed mathematical model which makes it possible to calculate the rate of surface plasmon-polariton excitation by active quantum dots. As a result, this rate can be determined without complicated expensive equipment for fast time-resolved measurements.

  8. Measurements of soot production and thermal radiation from confined turbulent jet diffusion flames of methane

    SciTech Connect

    Brookes, S.J.; Moss, J.B.

    1999-01-01

    Turbulent methane/air jet diffusion flames at atmospheric and elevated pressure have been studied experimentally to provide data for coupled thermal radiation and soot production model development and validation. Although methane is only lightly sooting at atmospheric pressure, at elevated pressure the soot yield increases greatly. This allows the creation of a highly radiating flame, of moderate optical depth, within a laboratory scale rig. Spatially resolved flame properties needed for model validation have been measured at 1 and 3 atm. These measurements include detailed maps of mean mixture fraction, mean temperature, mean soot volume fraction, and mean and instantaneous spectrally resolved, path integrated radiation intensity.

  9. Note: Measurement system for the radiative forcing of greenhouse gases in a laboratory scale.

    PubMed

    Kawamura, Yoshiyuki

    2016-01-01

    The radiative forcing of the greenhouse gases has been studied being based on computational simulations or the observation of the real atmosphere meteorologically. In order to know the greenhouse effect more deeply and to study it from various viewpoints, the study on it in a laboratory scale is important. We have developed a direct measurement system for the infrared back radiation from the carbon dioxide (CO2) gas. The system configuration is similar with that of the practical earth-atmosphere-space system. Using this system, the back radiation from the CO2 gas was directly measured in a laboratory scale, which roughly coincides with meteorologically predicted value.

  10. Note: Measurement system for the radiative forcing of greenhouse gases in a laboratory scale.

    PubMed

    Kawamura, Yoshiyuki

    2016-01-01

    The radiative forcing of the greenhouse gases has been studied being based on computational simulations or the observation of the real atmosphere meteorologically. In order to know the greenhouse effect more deeply and to study it from various viewpoints, the study on it in a laboratory scale is important. We have developed a direct measurement system for the infrared back radiation from the carbon dioxide (CO2) gas. The system configuration is similar with that of the practical earth-atmosphere-space system. Using this system, the back radiation from the CO2 gas was directly measured in a laboratory scale, which roughly coincides with meteorologically predicted value. PMID:26827362

  11. Calibration of modified Liulin detector for cosmic radiation measurements on-board aircraft.

    PubMed

    Kyselová, D; Ambrožová, I; Krist, P; Kubančák, J; Uchihori, Y; Kitamura, H; Ploc, O

    2015-06-01

    The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them. Aircrew dosimetry is usually performed using special computer programs mostly based on results of Monte Carlo simulations. Contemporary, detectors are used mostly for validation of these computer codes, verification of effective dose calculations and for research purposes. One of such detectors is active silicon semiconductor deposited energy spectrometer Liulin. Output quantities of measurement with the Liulin detector are the absorbed dose in silicon D and the ambient dose equivalent H*(10); to determine it, two calibrations are necessary. The purpose of this work was to develop a calibration methodology that can be used to convert signal from the detector to D independently on calibration performed at Heavy Ion Medical Accelerator facility in Chiba, Japan. PMID:25979744

  12. Calibration of modified Liulin detector for cosmic radiation measurements on-board aircraft.

    PubMed

    Kyselová, D; Ambrožová, I; Krist, P; Kubančák, J; Uchihori, Y; Kitamura, H; Ploc, O

    2015-06-01

    The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them. Aircrew dosimetry is usually performed using special computer programs mostly based on results of Monte Carlo simulations. Contemporary, detectors are used mostly for validation of these computer codes, verification of effective dose calculations and for research purposes. One of such detectors is active silicon semiconductor deposited energy spectrometer Liulin. Output quantities of measurement with the Liulin detector are the absorbed dose in silicon D and the ambient dose equivalent H*(10); to determine it, two calibrations are necessary. The purpose of this work was to develop a calibration methodology that can be used to convert signal from the detector to D independently on calibration performed at Heavy Ion Medical Accelerator facility in Chiba, Japan.

  13. Indoor and outdoor in situ high-resolution gamma radiation measurements in urban areas of Cyprus.

    PubMed

    Svoukis, E; Tsertos, H

    2007-01-01

    In situ, high-resolution, gamma-ray spectrometry of a total number of 70 outdoor and 20 indoor representative measurements were performed in preselected, common locations of the main urban areas of Cyprus. Specific activities and gamma absorbed dose rates in air due to the naturally occurring radionuclides of (232)Th and (238)U series, and (40)K are determined and discussed. Effective dose rate to the Cyprus population due to terrestrial gamma radiation is derived directly from this work. The results obtained outdoors match very well with those derived previously by high-resolution gamma spectrometry of soil samples, which were collected from the main island bedrock surface. This implies that the construction and building materials in urban areas do not affect the external gamma dose rate; thus they are mostly of local origin. Finally, the indoor/outdoor gamma dose ratio was found to be 1.4 +/- 0.5. PMID:17065195

  14. The measurement of ultraviolet radiation and sunburn time over southern Ontario

    NASA Technical Reports Server (NTRS)

    Evans, W. F. J.

    1994-01-01

    Studies of the depletion of ozone which have been conducted from the TOMS instrument on the NIMBUS 7 satellite indicate that total ozone has declined by 5 percent over the last 12 years at most mid-latitudes in the Northern Hemisphere typical of southern Ontario. The measurement of the actual resultant increases in UVB is now important. A monitoring program of UVB (biologically active solar ultraviolet radiation) has been conducted for the last 24 months at a site near Bolton, Ontario. The sunburn time varies from less than 17 minutes in late July, to over 4 hours in December on clear days. The levels depend on solar insolation and total ozone column. The ultraviolet levels are strongly affected by cloud and sky conditions. The implications of present and future depletion on the sunburn time are discussed.

  15. Atmospheric aerosol variability in Estonia calculated from solar radiation measurements

    NASA Astrophysics Data System (ADS)

    Russak, Viivi

    1996-10-01

    Direct solar radiation data obtained during 1955 1994 at the Tõravere Actinometric Station (Estonia) have been used to study the long-term variations of the atmospheric aerosol. In a linear approximation, the optical thickness of atmospheric aerosol averaged over months from April to August has increased by 73% at Tõravere during the last 40years. The aerosol loading of the atmosphere depends on wind direction, the southern and southeastern winds being the main carriers of aerosol. During the last decade, the increase in the optical thickness of aerosol in the case of W-, NW- and N-winds has slowed down. This is most likely caused by a reduction in the SO2 emission in Western and Central Europe as well as in Finland. In April, the advection of aerosol is greatest from the NE-direction. We suppose that this effect points to the possibility of aerosol transfer to Estonia through the Arctic regions.

  16. Measurements of radiation effects on a 4 Mb PSRAM memory

    SciTech Connect

    Gonçalez, Odair Lelis; Pereira Junior, Evaldo Carlos Fonseca; Vaz, Rafael Galhardo; Pereira, Marlon Antonio; Wirth, Gilson Inácio; Both, Thiago Hanna

    2014-11-11

    The results of a static test of total ionizing dose (TID) effects on an ISSI 4Mb PSRAM memory are reported in this work. The irradiation was performed at the IEAv’s Laboratory of Ionizing Radiation with 1.17 and 1.32 MeV gamma-rays from a {sup 60}Co source at a dose rate of 2.5 krad/h up to an accumulated dose of 215.7 krad. The TID threshold for bit flip found in this experiment was 52.5 krad. From a sampling of 4096 memory addresses it was estimated a bit flip rate of approximately 50% at an accumulated dose of 215.7 krad.

  17. Atmospheric Radiation Measurement Program facilities newsletter, May 2000.

    SciTech Connect

    Sisterson, D.L.

    2000-06-01

    This month the authors will visit an ARM CART site with a pleasant climate: the Tropical Western Pacific (TWP) CART site, along the equator in the western Pacific Ocean. The TWP locale lies between 10 degrees North latitude and 10 degrees South latitude and extends from Indonesia east-ward beyond the international date line. This area was selected because it is in and around the Pacific warm pool, the area of warm sea-surface temperatures that determine El Nino/La Nina episodes. The warm pool also adds heat and moisture to the atmosphere and thus fuels cloud formation. Understanding the way tropical clouds and water vapor affect the solar radiation budget is a focus of the ARM Program. The two current island-based CART sites in the TWP are in Manus Province in Papua New Guinea and on Nauru Island.

  18. Radiation exposures during space flight and their measurement.

    PubMed

    Benton, E V; Henke, R P

    1983-01-01

    The paper reviews radiation exposures recorded during space flights of the US and USSR. Most of the data are from manned missions and include discussion of absorbed dose and dose rates as a function of parameters such as altitude, inclination, spacecraft type and shielding. Preliminary data exist on the neutron and HZE-particle component, as well as the LET spectra. For low Earth-orbit missions, the dose encountered is strongly altitude-dependent, with a weaker dependence upon inclination. The doses range from about 6 millirad per day for the Space Transportation System No. 3 flight to about 90 mrad per day for Skylab. The effective quality factor (QF) for the near-Earth orbits and free space has been estimated to be about 1.5 and about 5.5 respectively. Complete shielding from the galactic cosmic rays does not appear practical because of spacecraft weight limitations. PMID:11542745

  19. Calibrating a novel multi-sensor physical activity measurement system

    PubMed Central

    John, D; Liu, S; Sasaki, J E; Howe, C A; Staudenmayer, J; Gao, R X; Freedson, P S

    2011-01-01

    Advancing the field of physical activity (PA) monitoring requires the development of innovative multi-sensor measurement systems that are feasible in the free-living environment. The use of novel analytical techniques to combine and process these multiple sensor signals is equally important. This paper, describes a novel multi-sensor ‘Integrated PA Measurement System’ (IMS), the lab-based methodology used to calibrate the IMS, techniques used to predict multiple variables from the sensor signals, and proposes design changes to improve the feasibility of deploying the IMS in the free-living environment. The IMS consists of hip and wrist acceleration sensors, two piezoelectric respiration sensors on the torso, and an ultraviolet radiation sensor to obtain contextual information (indoors vs. outdoors) of PA. During lab-based calibration of the IMS, data were collected on participants performing a PA routine consisting of seven different ambulatory and free-living activities while wearing a portable metabolic unit (criterion measure) and the IMS. Data analyses on the first 50 adult participants are presented. These analyses were used to determine if the IMS can be used to predict the variables of interest. Finally, physical modifications for the IMS that could enhance feasibility of free-living use are proposed and refinement of the prediction techniques is discussed. PMID:21813941

  20. Electromagnetic Measurements in an Active Oilfield Environment

    NASA Astrophysics Data System (ADS)

    Schramm, K. A.; Aldridge, D. F.; Bartel, L. C.; Knox, H. A.; Weiss, C. J.

    2015-12-01

    An important issue in oilfield development pertains to mapping and monitoring of the fracture distributions (either natural or man-made) controlling subsurface fluid flow. Although microseismic monitoring and analysis have been used for this purpose for several decades, there remain several ambiguities and uncertainties with this approach. We are investigating a novel electromagnetic (EM) technique for detecting and mapping hydraulic fractures in a petroleum reservoir by injecting an electrically conductive contrast agent into an open fracture. The fracture is subsequently illuminated by a strong EM field radiated by a large engineered antenna. Specifically, a grounded electric current source is applied directly to the steel casing of the borehole, either at/near the wellhead or at a deep downhole point. Transient multicomponent EM signals (both electric and magnetic) scattered by the conductivity contrast are then recorded by a surface receiver array. We are presently utilizing advanced 3D numerical modeling algorithms to accurately simulate fracture responses, both before and after insertion of the conductive contrast agent. Model results compare favorably with EM field data recently acquired in a Permian Basin oilfield. However, extraction of the very-low-amplitude fracture signatures from noisy data requires effective noise suppression strategies such as long stacking times, rejection of outliers, and careful treatment of natural magnetotelluric fields. Dealing with the ever-present "episodic EM noise" typical in an active oilfield environment (associated with drilling, pumping, machinery, traffic, etc.) constitutes an ongoing problem. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.