WorldWideScience

Sample records for blackbody radiation

  1. Lorentz transformation of blackbody radiation.

    Science.gov (United States)

    Ford, G W; O'Connell, R F

    2013-10-01

    We present a simple calculation of the Lorentz transformation of the spectral distribution of blackbody radiation at temperature T. Here we emphasize that T is the temperature in the blackbody rest frame and does not change. We thus avoid the confused and confusing question of how temperature transforms. We show by explicit calculation that at zero temperature the spectral distribution is invariant. At finite temperature we find the well-known result familiar in discussions of the 2.7 K cosmic radiation. PMID:24229306

  2. Blackbody Radiation from Isolated Neptunes

    CERN Document Server

    Ginzburg, Sivan; Loeb, Abraham

    2016-01-01

    Recent analyses of the orbits of some Kuiper Belt objects hypothesize the presence of an undiscovered Neptune-size planet at a very large separation from the Sun. The energy budget of Neptunes on such distant orbits is dominated by the internal heat released by their cooling rather than solar irradiation (making them effectively "isolated"). The blackbody radiation that these planets emit as they cool may provide the means for their detection. Here we use an analytical toy model to study the cooling and radiation of isolated Neptunes. This model can translate a detection (or a null detection) to a constraint on the size and composition of the hypothesized "Planet Nine". Specifically, the thick gas atmosphere of Neptune-like planets serves as an insulating blanket which slows down their cooling. Therefore, a measurement of the blackbody temperature, $T_{\\rm eff}\\sim 50\\textrm{K}$, at which a Neptune emits can be used to estimate the mass of its atmosphere, $M_{\\rm atm}$. Explicitly, we find the relation $T_{\\r...

  3. Blackbody Radiation and the Carbon Particle

    Directory of Open Access Journals (Sweden)

    Pierre-Marie Robitaille

    2008-07-01

    Full Text Available Since the days of Kirchhoff, blackbody radiation has been considered to be a universal process, independent of the nature and shape of the emitter. Nonetheless, in promoting this concept, Kirchhoff did require, at the minimum, thermal equilibrium with an enclosure. Recently, the author stated (P.-M. Robitaille, IEEE Trans. Plasma Sci., 2003, v.31(6, 1263-1267; P.-M. Robitaille, Progr. in Phys., 2006, v.2, 22-23, that blackbody radiation is not universal and has called for a return to Stewart's law (P.-M. Robitaille, Progr. in Phys., 2008, v.3, 30-35. In this work, a historical analysis of thermal radiation is presented. It is demonstrated that soot, or lampblack, was the standard for blackbody experiments throughout the 1800s. Furthermore, graphite and carbon black continue to play a central role in the construction of blackbody cavities. The advent of universality is reviewed through the writings of Pierre Prevost, Pierre Louis Dulong, Alexis Therese Petit, Jean Baptiste Joseph Fourier, Simeon Denis Poisson, Frederick Herve de la Provostaye, Paul Quentin Desain, Balfour Stewart, Gustav Robert Kirchhoff, and Max Karl Ernst Ludwig Planck. These writings illustrate that blackbody radiation, as experimentally produced in cavities and as discussed theoretically, has remained dependent on thermal equilibrium with at least the smallest carbon particle. Finally, Planck's treatment of Kirchhoff's law is examined in detail and the shortcomings of his derivation are outlined. It is shown once again, that universality does not exist. Only Stewart's law of thermal emission, not Kirchhoff's, is fully valid.

  4. A blackbody radiation-pumped CO2 laser experiment

    Science.gov (United States)

    Christiansen, W. H.; Insuik, R. J.; Deyoung, R. J.

    1982-09-01

    Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping.

  5. Effective temperature and exergy of monochromic blackbody radiation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new parameter named monochromic effective temperature Tλ is proposed, which represents the thermodynamic quality of monochromic blackbody radiation. The exergy of the monochromic blackbody radiation is expressed by Tλ. The monochromic effective temperature equation is developed, which shows that the produci of Tλ and the wavelength is constant, which equals 5.33016×10-3 tion in photosynthesis can be explained by the results of this work.

  6. A regularized GMRES method for inverse blackbody radiation problem

    Directory of Open Access Journals (Sweden)

    Wu Jieer

    2013-01-01

    Full Text Available The inverse blackbody radiation problem is focused on determining temperature distribution of a blackbody from measured total radiated power spectrum. This problem consists of solving a first kind of Fredholm integral equation and many numerical methods have been proposed. In this paper, a regularized GMRES method is presented to solve the linear ill-posed problem caused by the discretization of such an integral equation. This method projects the orignal problem onto a lower dimensional subspaces by the Arnoldi process. Tikhonov regularization combined with GCV criterion is applied to stabilize the numerical iteration process. Three numerical examples indicate the effectiveness of the regularized GMRES method.

  7. Einstein's coefficients and the nature of thermal blackbody radiation

    OpenAIRE

    Prigara, F. V.

    2002-01-01

    We show that thermal radio emission has an induced character and argue that thermal blackbody radiation in other spectral ranges also has an induced origin. A new theory of thermal radio emission of non-uniform gas basing on the induced origin of emission and its astrophysical applications are considered. The nature of emission from various astrophysical objects is discussed.

  8. The Nature of Thermal Blackbody Radiation

    OpenAIRE

    Prigara, F. V.

    2002-01-01

    It was shown recently that thermal radio emission has a stimulated character, and it is quite possible that thermal black body radiation in other spectral ranges also has an induced origin. The induced origin of thermal black body emission leads to important astrophysical consequences, such as the existence of laser type sources and thermal harmonics in stellar spectra.

  9. Quantum driven dissipative parametric oscillator in a blackbody radiation field

    Energy Technology Data Exchange (ETDEWEB)

    Pachón, Leonardo A. [Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Department of Chemistry and Center for Quantum Information and Quantum Control, Chemical Physics Theory Group, University of Toronto, Toronto, Ontario M5S 3H6 (Canada); Brumer, Paul [Department of Chemistry and Center for Quantum Information and Quantum Control, Chemical Physics Theory Group, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

    2014-01-15

    We consider the general open system problem of a charged quantum oscillator confined in a harmonic trap, whose frequency can be arbitrarily modulated in time, that interacts with both an incoherent quantized (blackbody) radiation field and with an arbitrary coherent laser field. We assume that the oscillator is initially in thermodynamic equilibrium with its environment, a non-factorized initial density matrix of the system and the environment, and that at t = 0 the modulation of the frequency, the coupling to the incoherent and the coherent radiation are switched on. The subsequent dynamics, induced by the presence of the blackbody radiation, the laser field, and the frequency modulation, is studied in the framework of the influence functional approach. This approach allows incorporating, in analytic closed formulae, the non-Markovian character of the oscillator-environment interaction at any temperature as well the non-Markovian character of the blackbody radiation and its zero-point fluctuations. Expressions for the time evolution of the covariance matrix elements of the quantum fluctuations and the reduced density-operator are obtained.

  10. A history of slide rules for blackbody radiation computations

    Science.gov (United States)

    Johnson, R. Barry; Stewart, Sean M.

    2012-10-01

    During the Second World War the importance of utilizing detection devices capable of operating in the infrared portion of the electromagnetic spectrum was firmly established. Up until that time, laboriously constructed tables for blackbody radiation needed to be used in calculations involving the amount of radiation radiated within a given spectral region or for other related radiometric quantities. To rapidly achieve reasonably accurate calculations of such radiometric quantities, a blackbody radiation calculator was devised in slide rule form first in Germany in 1944 and soon after in England and the United States. In the immediate decades after its introduction, the radiation slide rule was widely adopted and recognized as a useful and important tool for engineers and scientists working in the infrared field. It reached its pinnacle in the United States in 1970 in a rule introduced by Electro Optical Industries, Inc. With the onset in the latter half of the 1970s of affordable, hand-held electronic calculators, the impending demise of the radiation slide rule was evident. No longer the calculational device of choice, the radiation slide rule all but disappeared within a few short years. Although today blackbody radiation calculations can be readily accomplished using anything from a programmable pocket calculator upwards, with each device making use of a wide variety of numerical approximations to the integral of Planck's function, radiation slide rules were in the early decades of infrared technology the definitive "workhorse" for those involved in infrared systems design and engineering. This paper presents a historical development of radiation slide rules with many versions being discussed.

  11. Secure thermal infrared communications using engineered blackbody radiation

    OpenAIRE

    Xiaoxin Liang; Fangjing Hu; Yuepeng Yan; Stepan Lucyszyn

    2014-01-01

    The thermal (emitted) infrared frequency bands, from 20–40 THz and 60–100 THz, are best known for applications in thermography. This underused and unregulated part of the spectral range offers opportunities for the development of secure communications. The ‘THz Torch' concept was recently presented by the authors. This technology fundamentally exploits engineered blackbody radiation, by partitioning thermally-generated spectral noise power into pre-defined frequency channels; the energy in ea...

  12. Blackbody-induced radiative dissociation of cationic SF 6 clusters

    DEFF Research Database (Denmark)

    Toker, Jonathan; Rahinov, I.; Schwalm, D.;

    2012-01-01

    The stability of cationic SF5+(SF6)n−1 clusters was investigated by measuring their blackbody-induced radiative dissociation (BIRD) rates. The clusters were produced in a supersonic expansion ion source and stored in an electrostatic ion-beam trap at room temperature, where their abundances...... and lifetimes were measured. Using the “master equation” approach, relative binding energies of an SF6 unit in the clusters could be extracted from the storage-time dependence of the survival probabilities. The results allow for a deeper insight into the effect of a localized charge on the structure...... and stability of SF6-based clusters....

  13. Equilibrium properties of blackbody radiation in Doubly Special Relativity

    CERN Document Server

    Chandra, Nitin; Vaibhav, Vinay

    2016-01-01

    Doubly Special Relativity (DSR) is an attempt to incorporate an observer independent energy/length scale in the relativistic theory. We study various thermodynamic properties of blackbody radiation in DSR. We find that the energy density, specific heat etc. follows usual acoustic phonon dynamics as has been well studied by Debye. Other thermodynamic quantities like pressure, entropy etc. has also been calculated. The usual Stefan-Boltzmann law gets modified. The phase-space measure is also expected to get modified for an exotic spacetime, which in turn leads to the modification of Planck energy density distribution and the Wien's displacement law.

  14. Broadband infrared vibrational nano-spectroscopy using thermal blackbody radiation.

    Science.gov (United States)

    O'Callahan, Brian T; Lewis, William E; Möbius, Silke; Stanley, Jared C; Muller, Eric A; Raschke, Markus B

    2015-12-14

    Infrared vibrational nano-spectroscopy based on scattering scanning near-field optical microscopy (s-SNOM) provides intrinsic chemical specificity with nanometer spatial resolution. Here we use incoherent infrared radiation from a 1400 K thermal blackbody emitter for broadband infrared (IR) nano-spectroscopy. With optimized interferometric heterodyne signal amplification we achieve few-monolayer sensitivity in phonon polariton spectroscopy and attomolar molecular vibrational spectroscopy. Near-field localization and nanoscale spatial resolution is demonstrated in imaging flakes of hexagonal boron nitride (hBN) and determination of its phonon polariton dispersion relation. The signal-to-noise ratio calculations and analysis for different samples and illumination sources provide a reference for irradiance requirements and the attainable near-field signal levels in s-SNOM in general. The use of a thermal emitter as an IR source thus opens s-SNOM for routine chemical FTIR nano-spectroscopy. PMID:26698997

  15. Nonlinear vacuum polarization in intense blackbody radiation and its effects on the radiation spectrum

    Science.gov (United States)

    Wu, Sheldon; Hartemann, Frederic; Siders, Craig; Barty, Christopher

    2009-11-01

    A study of thermally induced vacuum polarization stemming from the Euler-Heisenberg radiation correction to Maxwell equations is conducted. While nonlinear effects associated with interactions of electromagnetic pulse with a background photon gas had been previously calculated, we examine the possibility of nonlinear corrective terms to the blackbody radiation spectrum. Suitable conditions can be found in both astrophysical and laboratory environments. Inertial confined, ignited thermonuclear plasmas will produce intense blackbody radiation at temperatures in excess of 20 keV. In this theoretical investigation, our analysis shows that in an ideal incoherent blackbody the radiation spectrum is unaffected in the regime studied. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  16. Secure thermal infrared communications using engineered blackbody radiation

    Science.gov (United States)

    Liang, Xiaoxin; Hu, Fangjing; Yan, Yuepeng; Lucyszyn, Stepan

    2014-06-01

    The thermal (emitted) infrared frequency bands, from 20-40 THz and 60-100 THz, are best known for applications in thermography. This underused and unregulated part of the spectral range offers opportunities for the development of secure communications. The `THz Torch' concept was recently presented by the authors. This technology fundamentally exploits engineered blackbody radiation, by partitioning thermally-generated spectral noise power into pre-defined frequency channels; the energy in each channel is then independently pulsed modulated and multiplexing schemes are introduced to create a robust form of short-range secure communications in the far/mid infrared. To date, octave bandwidth (25-50 THz) single-channel links have been demonstrated with 380 bps speeds. Multi-channel `THz Torch' frequency division multiplexing (FDM) and frequency-hopping spread-spectrum (FHSS) schemes have been proposed, but only a slow 40 bps FDM scheme has been demonstrated experimentally. Here, we report a much faster 1,280 bps FDM implementation. In addition, an experimental proof-of-concept FHSS scheme is demonstrated for the first time, having a 320 bps data rate. With both 4-channel multiplexing schemes, measured bit error rates (BERs) of < 10-6 are achieved over a distance of 2.5 cm. Our approach represents a new paradigm in the way niche secure communications can be established over short links.

  17. On the thermodynamics of the conversion of partially polarized black-body radiation

    OpenAIRE

    Badescu, V.

    1992-01-01

    This paper considers a model consisting of : (i) a source of partially polarized black-body radiation (the pump), (ii) a thermally radiative or non-radiative ambient sink and (iii) two energy converters. The first converter (RH) transforms the energy of the black-body radiation into heat, while the second one (HW) (which has a non-zero entropy generation rate) uses that heat to produce work. The entropy-generation rates in the two converters are non-negative only when some conditions are sati...

  18. Polylogarithmic Representation of Radiative and Thermodynamic Properties of Thermal Radiation in a Given Spectral Range: I. Blackbody Radiation

    Science.gov (United States)

    Fisenko, Anatoliy I.; Lemberg, Vladimir

    2015-07-01

    The thermodynamics of blackbody radiation has been constructed for the entire range of the spectrum. However, in practical applications, thermodynamic functions must be calculated within a finite range of frequencies. The analytical expressions for the radiative and thermodynamic properties of blackbody radiation over an arbitrary spectral range of the electromagnetic spectrum are obtained. The Wien displacement law, Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, and pressure are expressed in terms of the polylogarithm functions. These expressions are important when we build a theoretical model of radiative heat transfer, for example. The thermodynamic functions of blackbody radiation are calculated for various ranges of the spectrum at different temperatures. As an example of practical applications, thermodynamics of the cosmic microwave background radiation measured by the COBE FIRAS instrument is constructed. The expressions obtained for the radiative and thermodynamic functions of blackbody radiation can easily be presented in wavelength and wavenumber domains.

  19. Analysis of the blackbody-radiation shift in an ytterbium optical lattice clock

    Science.gov (United States)

    Xu, Yi-Lin; Xu, Xin-Ye

    2016-10-01

    We accurately evaluate the blackbody-radiation shift in a 171Yb optical lattice clock by utilizing temperature measurement and numerical simulation. In this work. three main radiation sources are considered for the blackbody-radiation shift, including the heated atomic oven, the warm vacuum chamber, and the room-temperature vacuum windows. The temperatures on the outer surface of the vacuum chamber are measured during the clock operation period by utilizing seven calibrated temperature sensors. Then we infer the temperature distribution inside the vacuum chamber by numerical simulation according to the measured temperatures. Furthermore, we simulate the temperature variation around the cold atoms while the environmental temperature is fluctuating. Finally, we obtain that the total blackbody-radiation shift is -1.289(7) Hz with an uncertainty of 1.25 × 10-17 for our 171Yb optical lattice clock. The presented method is quite suitable for accurately evaluating the blackbody-radiation shift of the optical lattice clock in the case of lacking the sensors inside the vacuum chamber. Project supported by the National Key Basic Research and Development Program of China (Grant No. 2012CB821302), the National Natural Science Foundation of China (Grant No. 11134003), the National High Technology Research and Development Program of China (Grant No. 2014AA123401), and the Shanghai Excellent Academic Leaders Program of China (Grant No. 12XD1402400).

  20. Fermi golden rule for $N$-body systems in a black-body radiation

    CERN Document Server

    Ostilli, Massimo

    2016-01-01

    We review the calculation of the Fermi golden rule for a system of $N$-body dipoles, magnetic or electric, weakly interacting with a black-body radiation. By using the magnetic or electric field-field correlation function evaluated in the 1960s for the black body radiation, we deduce a general formula for the transition rates and study its limiting, fully coherent or fully incoherent, regimes.

  1. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody.

    Science.gov (United States)

    Zhu, Linxiao; Raman, Aaswath P; Fan, Shanhui

    2015-10-01

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities. PMID:26392542

  2. Entropy and complexity properties of the d-dimensional blackbody radiation

    CERN Document Server

    Toranzo, I V

    2015-01-01

    Space dimensionality is a crucial variable in the analysis of the structure and dynamics of natural systems and phenomena. The dimensionality effects of the blackbody radiation has been the subject of considerable research activity in recent years. These studies are still somewhat fragmentary, pos- ing formidable qualitative and quantitative problems for various scientific and technological areas. In this work we carry out an information-theoretical analysis of the spectral energy density of a d-dimensional blackbody at temperature T by means of various entropy-like quantities (disequilibrium, Shannon entropy, Fisher information) as well as by three (dimensionless) complexity measures (Cr\\'amer-Rao, Fisher-Shannon and LMC). All these frequency-functional quantities are calculated and discussed in terms of temperature and dimensionality. It is shown that all three measures of complexity have an universal character in the sense that they depend neither on temperature nor on the Planck and Boltzmann constants, b...

  3. Laser trapping of 225Ra and 226Ra with repumping by room-temperature blackbody radiation.

    Science.gov (United States)

    Guest, J R; Scielzo, N D; Ahmad, I; Bailey, K; Greene, J P; Holt, R J; Lu, Z-T; O'Connor, T P; Potterveld, D H

    2007-03-01

    We have demonstrated Zeeman slowing and capture of neutral 225Ra and 226Ra atoms in a magneto-optical trap. The intercombination transition 1S0-->3P1 is the only quasicycling transition in radium and was used for laser-cooling and trapping. Repumping along the 3D1-->1P1 transition extended the lifetime of the trap from milliseconds to seconds. Room-temperature blackbody radiation was demonstrated to provide repumping from the metastable 3P0 level. We measured the isotope shift and hyperfine splittings on the 3D1-->1P1 transition with the laser-cooled atoms, and set a limit on the lifetime of the 3D1 level based on the measured blackbody repumping rate. Laser-cooled and trapped radium is an attractive system for studying fundamental symmetries. PMID:17359153

  4. Laser-trapping of Ra-225 and Ra-226 with repumping by room temperature blackbody radiation

    CERN Document Server

    Guest, J R; Bailey, K; Greene, J P; Holt, R J; Lu, Z T; O'Connor, T P; Potterveld, D H; Scielzo, N D

    2007-01-01

    We have demonstrated Zeeman slowing and capture of neutral Ra-225 and Ra-226 atoms in a magneto-optical trap (MOT). The intercombination transition 1S0-3P1 is the only quasi-cycling transition in radium and was used for laser-cooling and trapping. Repumping along the 3D1-1P1 transition extended the lifetime of the trap from milliseconds to seconds. Room-temperature blackbody radiation was demonstrated to provide repumping from the metastable 3P0 level. We measured the isotope shift and hyperfine splittings on the 3D1-1P1 transition with the laser-cooled atoms, and set a limit on the lifetime of the 3D1 level based on the measured blackbody repumping rate. Laser-cooled and trapped radium is an attractive system for studying fundamental symmetries.

  5. Polylogarithmic representation of radiative and thermodynamic properties of thermal radiation in a given spectral range: I. Blackbody radiation

    CERN Document Server

    Fisenko, Anatoliy I

    2014-01-01

    Using polylogarithm functions the exact analytical expressions for the radiative and thermodynamic properties of blackbody radiation, such as the Wien displacement law, Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies are constructed. The obtained expressions allow us to tabulate these functions in various finite frequency bands at different temperatures for practical applications. As an example, the radiative and thermodynamic functions using experimental data for the monopole spectrum of the Cosmic Microwave Background (CMB) radiation measured by the COBE FIRAS instrument in the 60 - 600 GHz frequency interval at the temperature T = 2.725 K are calculated. The expressions obtained for the radiative and thermodynamic functions can be easily presented in wavelength and wavenumber domains.

  6. Perfect blackbody radiation from a graphene nanostructure with application to high-temperature spectral emissivity measurements.

    Science.gov (United States)

    Matsumoto, Takahiro; Koizumi, Tomoaki; Kawakami, Yasuyuki; Okamoto, Koichi; Tomita, Makoto

    2013-12-16

    We report the successful fabrication of a novel type of blackbody material based on a graphene nanostructure. We demonstrate that the graphene nanostructure not only shows a low reflectance comparable to that of a carbon nanotube array but also shows an extremely high heat resistance at temperatures greater than 2500 K. The graphene nanostructure, which has an emissivity higher than 0.99 over a wide range of wavelengths, behaves as a standard blackbody material; therefore, the radiation spectrum and the temperature can be precisely measured in a simple manner. Here, the spectral emissivities of tungsten and tantalum are experimentally obtained using this ideal blackbody material and are compared to previously reported spectra. We clearly demonstrate the existence of a temperature-independent fixed point of emissivity at a certain wavelength. Both the spectral emissivity as a function of temperature and the cross-over point in the emissivity spectrum are well described by the complex dielectric function based on the Lorentz-Drude model with the phonon-scattering effect.

  7. Perfect blackbody radiation from a graphene nanostructure with application to high-temperature spectral emissivity measurements.

    Science.gov (United States)

    Matsumoto, Takahiro; Koizumi, Tomoaki; Kawakami, Yasuyuki; Okamoto, Koichi; Tomita, Makoto

    2013-12-16

    We report the successful fabrication of a novel type of blackbody material based on a graphene nanostructure. We demonstrate that the graphene nanostructure not only shows a low reflectance comparable to that of a carbon nanotube array but also shows an extremely high heat resistance at temperatures greater than 2500 K. The graphene nanostructure, which has an emissivity higher than 0.99 over a wide range of wavelengths, behaves as a standard blackbody material; therefore, the radiation spectrum and the temperature can be precisely measured in a simple manner. Here, the spectral emissivities of tungsten and tantalum are experimentally obtained using this ideal blackbody material and are compared to previously reported spectra. We clearly demonstrate the existence of a temperature-independent fixed point of emissivity at a certain wavelength. Both the spectral emissivity as a function of temperature and the cross-over point in the emissivity spectrum are well described by the complex dielectric function based on the Lorentz-Drude model with the phonon-scattering effect. PMID:24514669

  8. A new blackbody radiation law based on fractional calculus and its application to NASA COBE data

    OpenAIRE

    Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi

    2015-01-01

    By applying fractional calculus to the equation proposed by M. Planck in 1900, we obtain a new blackbody radiation law described by a Mittag-Leffler (ML) function. We have analyzed NASA CODE data by means of a non-extensive formula with a parameter (q - 1), a formula proposed by Ertik et al. with a fractional parameter (alpha - 1), and our new formula including a parameter (p - 1), as well as the Bose-Einstein distribution with a dimensionless chemical potential mu. It can be said that one ro...

  9. A New Blackbody Radiation Law Based on Fractional Calculus and its Application to NASA COBE Data

    OpenAIRE

    Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi

    2015-01-01

    By applying fractional calculus to the equation proposed by M. Planck in 1900, we obtain a new blackbody radiation law described by a Mittag-Leffler (ML) function. We have analyzed NASA COBE data by means of a non-extensive formula with a parameter $(q-1)$, a formula proposed by Ertik et al. with a fractional parameter $(\\alpha-1)$, and our new formula including a parameter $(p-1)$, as well as the Bose-Einstein distribution with a dimensionless chemical potential $\\mu$. It can be said that on...

  10. Laser-trapping of Ra-225 and Ra-226 with repumping by room temperature blackbody radiation

    OpenAIRE

    Guest, J R; Scielzo, N. D.; Ahmad, I.; Bailey, K.; Greene, J. P.; Holt, R J; Lu, Z. -T.; O'Connor, T. P.; Potterveld, D. H.

    2007-01-01

    We have demonstrated Zeeman slowing and capture of neutral Ra-225 and Ra-226 atoms in a magneto-optical trap (MOT). The intercombination transition 1S0-3P1 is the only quasi-cycling transition in radium and was used for laser-cooling and trapping. Repumping along the 3D1-1P1 transition extended the lifetime of the trap from milliseconds to seconds. Room-temperature blackbody radiation was demonstrated to provide repumping from the metastable 3P0 level. We measured the isotope shift and hyperf...

  11. Differential thermoluminescence (DTL) -a new instrument for measurement of thermoluminescence with suppression of blackbody radiation.

    Science.gov (United States)

    Manche, E P

    1978-06-01

    A new instrumental technique for the determination of thermoluminescent glow curves, especially useful for investigation at high temperatures, is described. Two samples, identical in all respects except that one is preheated, are simultaneously heated. The light outputs from the samples are individually modulated at two different frequencies, fed to a single photomultiplier tube the output of which is amplified by two lock-in amplifiers. The selectively amplified signals are further fed to a differential amplifier which cancels out the undesirable blackbody radiation to give a signal due only to the luminophor. This technique conveniently extends the temperature range of thermoluminescence and further allows high-temperature investigation of emissions in the red region of the spectrum.

  12. A new blackbody radiation law based on fractional calculus and its application to NASA COBE data

    Science.gov (United States)

    Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi

    2015-12-01

    By applying fractional calculus to the equation proposed by M. Planck in 1900, we obtain a new blackbody radiation law described by a Mittag-Leffler (ML) function. We have analyzed NASA COBE data by means of a non-extensive formula with a parameter (q - 1) , a formula proposed by Ertik et al. with a fractional parameter (α - 1) , and our new formula including a parameter (p - 1) , as well as the Bose-Einstein distribution with a dimensionless chemical potential μ. It can be said that one role of the fractional parameter (p - 1) is almost the same as that of chemical potential (μ) as well as that of the parameter (q - 1) in the non-extensive approach.

  13. Measurement of the energy and power radiated by a pulsed blackbody x-ray source.

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, Gordon Andrew; McDaniel, Dillon Heirman; Jorgenson, Roy E.; Warne, Larry Kevin; Dropinski, Steven Clark; Hanson, Donald L.; Johnson, William Arthur; York, Mathew William; Lewis, D.F. (International Specialty Products, Wayne , NJ); Korde, R. (International Radiation Detectors, Torrance, CA); Haslett, C.L. (Ktech Corporation, Albuquerque, NM); Wall, D.L. (Resonetics, Nashua, New hampshire); Ruggles, Laurence E.; Ramirez, L.E. (ATK Mission Research Corporation, Albuquerque, NM); Stygar, William A.; Porter, John Larry, Jr.; McKenney, John Lee; Bryce, Edwin Anthony; Cuneo, Michael Edward; Torres, Jose A.; Mills, Jerry Alan; Leeper, Ramon Joe; McGurn, John Stephen; Fehl, David Lee; Spielman, R. B. (International Specialty Products, Wayne , NJ); Pyle, John H. (Ktech Corporation, Albuquerque, NM); Mazarakis, Michael Gerrassimos; Ives, Harry Crockett, III (EG& G, Albuquerque, NM); Seamen, Johann F.; Simpson, Walter W.

    2006-02-01

    We have developed a diagnostic system that measures the spectrally integrated (i.e. the total) energy and power radiated by a pulsed blackbody x-ray source. The total-energy-and-power (TEP) diagnostic system is optimized for blackbody temperatures between 50 and 350 eV. The system can view apertured sources that radiate energies and powers as high as 2 MJ and 200 TW, respectively, and has been successfully tested at 0.84 MJ and 73 TW on the Z pulsed-power accelerator. The TEP system consists of two pinhole arrays, two silicon-diode detectors, and two thin-film nickel bolometers. Each of the two pinhole arrays is paired with a single silicon diode. Each array consists of a 38 x 38 square array of 10-{micro}m-diameter pinholes in a 50-{micro}m-thick tantalum plate. The arrays achromatically attenuate the x-ray flux by a factor of {approx}1800. The use of such arrays for the attenuation of soft x rays was first proposed by Turner and co-workers [Rev. Sci. Instrum. 70, 656 (1999)RSINAK0034-674810.1063/1.1149385]. The attenuated flux from each array illuminates its associated diode; the diode's output current is recorded by a data-acquisition system with 0.6-ns time resolution. The arrays and diodes are located 19 and 24 m from the source, respectively. Because the diodes are designed to have an approximately flat spectral sensitivity, the output current from each diode is proportional to the x-ray power. The nickel bolometers are fielded at a slightly different angle from the array-diode combinations, and view (without pinhole attenuation) the same x-ray source. The bolometers measure the total x-ray energy radiated by the source and--on every shot--provide an in situ calibration of the array-diode combinations. Two array-diode pairs and two bolometers are fielded to reduce random uncertainties. An analytic model (which accounts for pinhole-diffraction effects) of the sensitivity of an array-diode combination is presented.

  14. Measurement of the energy and power radiated by a pulsed blackbody x-ray source

    International Nuclear Information System (INIS)

    We have developed a diagnostic system that measures the spectrally integrated (i.e. the total) energy and power radiated by a pulsed blackbody x-ray source. The total-energy-and-power (TEP) diagnostic system is optimized for blackbody temperatures between 50 and 350 eV. The system can view apertured sources that radiate energies and powers as high as 2 MJ and 200 TW, respectively, and has been successfully tested at 0.84 MJ and 73 TW on the Z pulsed-power accelerator. The TEP system consists of two pinhole arrays, two silicon-diode detectors, and two thin-film nickel bolometers. Each of the two pinhole arrays is paired with a single silicon diode. Each array consists of a 38 x 38 square array of 10-(micro)m-diameter pinholes in a 50-(micro)m-thick tantalum plate. The arrays achromatically attenuate the x-ray flux by a factor of ∼1800. The use of such arrays for the attenuation of soft x rays was first proposed by Turner and co-workers [Rev. Sci. Instrum. 70, 656 (1999)RSINAK0034-674810.1063/1.1149385]. The attenuated flux from each array illuminates its associated diode; the diode's output current is recorded by a data-acquisition system with 0.6-ns time resolution. The arrays and diodes are located 19 and 24 m from the source, respectively. Because the diodes are designed to have an approximately flat spectral sensitivity, the output current from each diode is proportional to the x-ray power. The nickel bolometers are fielded at a slightly different angle from the array-diode combinations, and view (without pinhole attenuation) the same x-ray source. The bolometers measure the total x-ray energy radiated by the source and--on every shot--provide an in situ calibration of the array-diode combinations. Two array-diode pairs and two bolometers are fielded to reduce random uncertainties. An analytic model (which accounts for pinhole-diffraction effects) of the sensitivity of an array-diode combination is presented

  15. Determination of the 5d6s 3D1 state lifetime and blackbody radiation clock shift in Yb

    CERN Document Server

    Beloy, K; Lemke, N D; Hinkley, N; Oates, C W; Ludlow, A D

    2012-01-01

    The Stark shift of the ytterbium optical clock transition due to room temperature blackbody radiation is dominated by a static Stark effect, which was recently measured to high accuracy [J. A. Sherman et al., Phys. Rev. Lett. 108, 153002 (2012)]. However, room temperature operation of the clock at 10^{-18} inaccuracy requires a dynamic correction to this static approximation. This dynamic correction largely depends on a single electric dipole matrix element for which theoretically and experimentally derived values disagree significantly. We determine this important matrix element by two independent methods, which yield consistent values. Along with precise radiative lifetimes of 6s6p 3P1 and 5d6s 3D1, we report the clock's blackbody radiation shift to 0.05% precision.

  16. Nonlinear Vacuum Polarization In Intense Blackbody Radiation And The Generation Of Cherenkov Radiation By Energetic Charged Particles

    Science.gov (United States)

    Wu, Sheldon S. Q.; Hartemann, F. V.; Barty, C. P. J.

    2010-03-01

    A study of thermally-induced vacuum polarization stemming from the Euler-Heisenberg nonlinear radiation correction to Maxwell equations is conducted. While nonlinear effects associated with photon-photon scattering in the photon gas had been previously calculated, we present an analysis in the framework of stochastic electrodynamics. To lowest order of approximation, it is shown that the phase velocity of light is reduced in the presence of intense ambient electromagnetic radiation. Therefore Cherenkov radiation can be generated when charged particles traverse a region of intense blackbody radiation. Suitable conditions may be found in astrophysical environments. Cosmic ray electrons and positrons in the GeV to TeV range meet the energy requirement for this process to occur. We present calculations of the emission characteristics and conditions under which Cherenkov radiation may be observed. This effect combined with synchrotron and inverse Compton processes may lead to a more complete understanding of cosmic ray propagation. Also of interest, the question of the linearity of the relic cosmic microwave background is under investigation using this formalism and will be discussed. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  17. Onset of optical-phonon cooling in multilayer graphene revealed by RF noise and black-body radiation thermometries

    International Nuclear Information System (INIS)

    We report on electron cooling power measurements in few-layer graphene excited by Joule heating by means of a new setup combining electrical and optical probes of the electron and phonon baths temperatures. At low bias, noise thermometry allows us to retrieve the well known acoustic phonon cooling regimes below and above the Bloch-Grüneisen temperature, with additional control over the phonon bath temperature. At high electrical bias, we show the relevance of direct optical investigation of the electronic temperature by means of black-body radiation measurements. In this regime, the onset of new efficient relaxation pathways involving optical modes is observed. (paper)

  18. Role of the multipolar black-body radiation shifts in the atomic clocks at the 10-18 uncertainty level

    Indian Academy of Sciences (India)

    B K Sahoo

    2014-08-01

    We present here an overview of the role of the multipolar black-body radiation (BBR) shifts in the single ion atomic clocks to appraise the anticipated 10-18 uncertainty level. With an attempt to use the advanced technologies for reducing the instrumental uncertainties at the unprecedented low, it is essential to investigate contributions from the higher-order systematics to achieve the ambitious goal of securing the most precise clock frequency standard. In this context, we have analysed contributions to the BBR shifts from the multipolar polarizabilities in a few ion clocks.

  19. Black-body radiation shift of atomic energy-levels:The $ (Z \\alpha)^2\\alpha T^2/m $ correction

    OpenAIRE

    Zhou, Wanping; Mei, Xuesong; Lu, Jingjun; Qiao, Haoxue

    2016-01-01

    The next-to-leading order black-body radiation(BBR) shift to atomic energy-levels, namely $ (Z\\alpha)^2\\alpha T^2/m $ correction, was studied by using the nonrelativistic quantum electrodynamics(NRQED). We also estimate the one-loop contribution of quadrupole and the two-loop contributions of BBR-shift of the thermal(real) photon. These corrections have not been investigated before. The order of magnitude BBR-shift indicates the one-loop contribution of quadrupole is stronger than the previou...

  20. The relativistic one-loop and two-loop black-body radiation shift of atomic energy-levels

    OpenAIRE

    Zhou, Wanping; Mei, Xuesong; Qiao, Haoxue

    2016-01-01

    The thermal relativistic one-loop and two-loop self-energy corrections of atomic energy-levels induced by the blackbody radiation(BBR) are studied. We estimated the magnitude of BBR-shift of this results in the hydrogen-like atom. The order of magnitude indicated the two loop correction of the real photon is feeble, but that thermal relativistic one-loop self-energy correction and the thermal two-loop self-energy corrections induced by real and virtual photon are abnormal high, which may exce...

  1. The relativistic one-loop and two-loop black-body radiation shift of atomic energy-levels

    CERN Document Server

    Zhou, Wanping; Qiao, Haoxue

    2016-01-01

    The thermal relativistic one-loop and two-loop self-energy corrections of atomic energy-levels induced by the blackbody radiation(BBR) are studied. We estimated the magnitude of BBR-shift of this results in the hydrogen-like atom. The order of magnitude indicated the two loop correction of the real photon is feeble, but that thermal relativistic one-loop self-energy correction and the thermal two-loop self-energy corrections induced by real and virtual photon are abnormal high, which may exceed the leading order correction of BBR in the hydrogen with high $Z$ or low $T$.

  2. Upconversion luminescence and blackbody radiation in tetragonal YSZ co-doped with Tm(3+) and Yb(3+).

    Science.gov (United States)

    Soares, M R N; Ferro, M; Costa, F M; Monteiro, T

    2015-12-21

    Lanthanide doped inorganic nanoparticles with upconversion luminescence are of utmost importance for biomedical applications, solid state lighting and photovoltaics. In this work we studied the downshifted luminescence, upconversion luminescence (UCL) and blackbody radiation of tetragonal yttrium stabilized zirconia co-doped with Tm(3+) and Yb(3+) single crystals and nanoparticles produced by laser floating zone and laser ablation in liquids, respectively. The photoluminescence (PL) and PL excitation (PLE) were investigated at room temperature (RT). PL spectra exhibit the characteristic lines in UV, blue/green, red and NIR regions of the Tm(3+) (4f(12)) under resonant excitation into the high energy (2S+1)LJ multiplets. Under NIR excitation (980 nm), the samples placed in air display an intense NIR at ∼800 nm due to the (1)G4→(3)H5/(3)H4→(3)H6 transitions. Additionally, red, blue/green and ultraviolet UCL is observed arising from higher excited (1)G4 and (1)D2 multiplets. The power excitation dependence of the UCL intensity indicated that 2-3 low energy absorbed photons are involved in the UCL for low power levels, while for high powers, the identified saturation is dependent on the material size with a enhanced effect on the NPs. The temperature dependence of the UCL was investigated for single crystals and targets used in the ablation. An overall increase of the integrated intensity was found to occur between 12 K and the RT. The thermally activated process is described by activation energies of 10 meV and 30 meV for single crystals and targets, respectively. For the NPs, the UCL was found to be strongly sensitive to pressure conditions. Under vacuum conditions, instead of the narrow lines of the Tm(3+), a wide blackbody radiation was detected, responsible for the change in the emission colour from blue to orange. This phenomenon is totally reversible when the NPs are placed at ambient pressure. The UCL/blackbody radiation in the nanosized material exhibits

  3. Evidence from the Special Relativity and Blackbody Radiation Theories for the Existence of Photons Possessing Zero Kinetic Energy

    CERN Document Server

    Buenker, R J

    1992-01-01

    The traditional interpretation of radiative emission and absorption asserts that photons are created and annihilated in such processes. A Gedanken experiment is considered in which kinetic energy from observed photons is systematically removed until a limit of zero is reached. With the help of the relativistic Doppler effect it is shown that even for infinitesimally small kinetic energies the photons continue to exist, since in other inertial systems they will be observed to have a much higher energy/frequency falling in an easily detectable range. It is possible to formulate an alternative explanation for absorption and emission processes on this basis in terms of real photons with exactly zero kinetic energy being present before or after radiative interactions. Bolstering this hypothesis is the fact that the statistical mechanical treatment of photons interacting with oscillators in blackbody radiation theory predicts an infinite density of photons of this energy, both in the original Planck formulation emp...

  4. Einstein-Hopf drag, Doppler shift of thermal radiation and blackbody friction: A unifying perspective on an intriguing physical effect

    CERN Document Server

    Lach, G; Jentschura, U D

    2011-01-01

    The thermal friction force acting on an atom moving relative to a thermal photon bath has recently been calculated on the basis of the fluctuation-dissipation theorem. The thermal fluctuations of the electromagnetic field give rise to a drag force on an atom provided one allows for dissipation of the field energy via spontaneous emission. The drag force exists if the atomic polarizability has a nonvanishing imaginary part. Here, we explore alternative derivations. The damping of the motion of a simple harmonic oscillator is described by radiative reaction theory (result of Einstein and Hopf), taking into account the known stochastic fluctuations of the electromagnetic field. Describing the excitations of the atom as an ensemble of damped harmonic oscillators, we identify the previously found expressions as generalizations of the Einstein-Hopf result. In addition, we present a simple explanation for blackbody friction in terms of a Doppler shift of the thermal radiation in the inertial frame of the moving atom...

  5. Laser-trapping of {sup 225}Ra and {sup 226}Ra with repumping by room-temperature blackbody radiation.

    Energy Technology Data Exchange (ETDEWEB)

    Guest, J. R.; Scielzo, N. D.; Ahmad, I.; Bailey, K.; Greene, J. P.; Holt, R. J.; Lu, Z.-T.; O' Connor, T. P.; Potterveld, D. H.; Physics; Enrico Fermi Inst.; Univ. of Chicago

    2007-02-27

    We have demonstrated Zeeman slowing and capture of neutral {sup 225}Ra and {sup 226}Ra atoms in a magneto-optical trap. The intercombination transition {sup 1}S{sub 0} {yields} {sup 3}P{sub 1} is the only quasicycling transition in radium and was used for laser-cooling and trapping. Repumping along the {sup 3}D{sub 1} {yields} {sup 1}P{sub 1} transition extended the lifetime of the trap from milliseconds to seconds. Room-temperature blackbody radiation was demonstrated to provide repumping from the metastable {sup 3}P{sub 0} level. We measured the isotope shift and hyperfine splittings on the {sup 3}D{sub 1} {yields} {sup 1}P{sub 1} transition with the laser-cooled atoms, and set a limit on the lifetime of the {sup 3}D{sub 1} level based on the measured blackbody repumping rate. Laser-cooled and trapped radium is an attractive system for studying fundamental symmetries.

  6. Black-body radiation shift of atomic energy-levels:The $ (Z \\alpha)^2\\alpha T^2/m $ correction

    CERN Document Server

    Zhou, Wanping; Lu, Jingjun; Qiao, Haoxue

    2016-01-01

    The next-to-leading order black-body radiation(BBR) shift to atomic energy-levels, namely $ (Z\\alpha)^2\\alpha T^2/m $ correction, was studied by using the nonrelativistic quantum electrodynamics(NRQED) at first. This $T^{2}$-dependent correction has not been investigated before, and only contains the contribution of eletric-dipole of thermal photon. In order to study the contribution of multipolar. We estimate the two-loop contributions of BBR-shift by using quantum electrodynamics approach(QED), and find both one-loop and two-loop diagram contribute to the $ (Z\\alpha)^2\\alpha T^2/m $ correction. Integrating the results which are obtained by these two approaches, the $ (Z\\alpha)^2\\alpha T^2/m $ correction we derived is in principle applicable to multi-electron atoms and contains the contribution of multipolar. The order of magnitude BBR-shift indicates this next-to-leading order BBR-shift may be as significant as the leading order in the multi-electron atoms or cold ones.

  7. Relativistic many-body calculation of energies, lifetimes, polarizabilities, blackbody radiative shift and hyperfine constants in Lu2+

    CERN Document Server

    Safronova, U I; Johnson, W R

    2016-01-01

    Energy levels of 30 low-lying states of Lu2+ and allowed electric-dipole matrix elements between these states are evaluated using a relativistic all-order method in which all single, double and partial triple excitations of Dirac-Fock wave functions are included to all orders of perturbation theory. Matrix elements are critically evaluated for their accuracy and recommended values of the matrix elements are given together with uncertainty estimates. Line strengths, transition rates and lifetimes of the metastable 5d(3/2) and 5d(5/2) states are calculated. Recommended values are given for static polarizabilities of the 6s, 5d and 6p states and tensor polarizabilities of the 5d and 6p(3/2) states. Uncertainties of the polarizability values are estimated in all cases. The blackbody radiation shift of the 6s(1/2)-5d(5/2) transition frequency of the Lu2+ ion is calculated with the aid of the recommended scalar polarizabilities of the 6s(1/2) and 5d(5/2) states. Finally, A and B hyperfine constants are determined f...

  8. Relativistic many-body calculation of energies, lifetimes, polarizabilities, blackbody radiative shift, and hyperfine constants in Lu2 +

    Science.gov (United States)

    Safronova, U. I.; Safronova, M. S.; Johnson, W. R.

    2016-09-01

    Energy levels of 30 low-lying states of Lu2 + and allowed electric-dipole matrix elements between these states are evaluated using a relativistic all-order method in which all single, double, and partial triple excitations of Dirac-Fock wave functions are included to all orders of perturbation theory. Matrix elements are critically evaluated for their accuracy and recommended values of the matrix elements are given together with uncertainty estimates. Line strengths, transition rates, and lifetimes of the metastable 5 d3 /2 and 5 d5 /2 states are calculated. Recommended values are given for static polarizabilities of the 6 s , 5 d , and 6 p states and tensor polarizabilities of the 5 d and 6 p3 /2 states. Uncertainties of the polarizability values are estimated in all cases. The blackbody radiation shift of the 6 s1 /2-5 d5 /2 transition frequency of the Lu2 + ion is calculated with the aid of the recommended scalar polarizabilities of the 6 s1 /2 and 5 d5 /2 states. Finally, A and B hyperfine constants are determined for states of 2+175Lu with n ≤9 . This work provides recommended values of transition matrix elements, polarizabilities, and hyperfine constants of Lu2 +, critically evaluated for accuracy, for benchmark tests of high-precision theoretical methodology and planning of future experiments.

  9. Blackbody-pumped CO2 laser experiment

    Science.gov (United States)

    Christiansen, W. H.; Insuik, R. J.

    1983-07-01

    Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping. Previously announced in STAR as N83-10420

  10. Thermal radiation and blackbody radiation drag of a large-sized perfectly black particle moving with relativistic velocity

    OpenAIRE

    Kyasov, A. A.; Dedkov, G. V.

    2015-01-01

    We have developed a self-consistent description of the radiation heat transfer and dynamics of large perfectly black spherical bodies with sizes much greater than the characteristic wavelength of radiation moving in a photon gas with relativistic velocity. The results can be important in astrophysics.

  11. The Blackbody Radiation Spectrum Follows from Zero-Point Radiation and the Structure of Relativistic Spacetime in Classical Physics

    OpenAIRE

    Boyer, Timothy H.

    2011-01-01

    The analysis of this article is entirely within classical physics. Any attempt to describe nature within classical physics requires the presence of Lorentz-invariant classical electromagnetic zero-point radiation so as to account for the Casimir forces between parallel conducting plates at low temperatures. Furthermore, conformal symmetry carries solutions of Maxwell's equations into solutions. In an inertial frame, conformal symmetry leaves zero-point radiation invariant and does not connect...

  12. The static and dynamic polarisability, and the Stark and black-body radiation frequency shifts of the molecular hydrogen ions H2+, HD+, and D2+

    CERN Document Server

    Schiller, Stephan; Bekbaev, Ashat K; Korobov, Vladimir I

    2014-01-01

    We calculate the DC Stark effect for three molecular hydrogen ions in the non-relativistic approximation. The effect is calculated both in dependence on the rovibrational state and in dependence on the hyperfine state. We discuss special cases and approximations. We also calculate the AC polarisabilities for several rovibrational levels, and therefrom evaluate accurately the black-body radiation shift, including the effects of excited electronic states. The results enable the detailed evaluation of certain systematic shifts of the transitions frequencies for the purpose of ultra-high-precision optical, microwave or radio-frequency spectroscopy in ion traps.

  13. Blackbody metamaterial lasers

    KAUST Repository

    Liu, Changxu

    2015-01-01

    We investigate both theoretically and experimentally a new type of laser, which exploits a broadband light "condensation" process sustained by the stimulated amplification of an optical blackbody metamaterial. © 2014 Optical Society of America.

  14. Evaluation of blackbody radiation shift with temperature associated fractional uncertainty at 10E-18 level for 40Ca+ ion optical clock

    CERN Document Server

    Zhang, Ping; Shu, Hua-lin; Yuan, Jin-bo; Shang, Juan-juan; Cui, Kai-feng; Chao, Si-jia; Wang, Shao-mao; Liu, Dao-xin; Huang, Xue-ren

    2016-01-01

    In this paper, blackbody radiation (BBR) temperature rise seen by the $^{40}$Ca$^+$ ion confined in a miniature Paul trap and its uncertainty have been evaluated via finite-element method (FEM) modelling. The FEM model was validated by comparing with thermal camera measurements, which were calibrated by PT1000 resistance thermometer, at several points on a dummy trap. The input modelling parameters were analyzed carefully in detail, and their contributions to the uncertainty of environment temperature were evaluated on the validated FEM model. The result shows that the temperature rise seen by $^{40}$Ca$^+$ ion is 1.72 K with an uncertainty of 0.46 K. It results in a contribution of 2.2 mHz to the systematic uncertainty of $^{40}$Ca$^+$ ion optical clock, corresponding to a fractional uncertainty 5.4$\\times$10$^{-18}$. This is much smaller than the uncertainty caused by the BBR shift coefficient, which is evaluated to be 4.8 mHz and at 10$^{-17}$ level in fractional frequency units.

  15. Calculation of the effective emissivity of blackbodies made of alumina

    International Nuclear Information System (INIS)

    Blackbodies are sources of temperature radiation that are used for calibration of radiation thermometers. Their effective emissivity should be close to the value of 1 to approximate an ideal Planckian radiator. Their effective emissivity depends on the geometry of their cavity and the used material. It can be estimated by measurements, but often it is calculated by numerical methods. For typical graphite blackbodies, it was shown in the past that high effective emissivities better than 0.999 can be reached. In this paper, calculations of the effective emissivity of a alumina blackbody are presented. Alumina is a new material for blackbodies, with different radiation properties. Using two calculation methods (integrative cavity method and Monte Carlo method), the effective cavity emissivity for blank and coated alumina is estimated. It is shown that effective spectral emissivities up to 0.999 87 can be reached. (paper)

  16. Blackbody for metrological control of ear thermometers

    Science.gov (United States)

    Cárdenas-García, D.; Méndez-Lango, E.

    2013-09-01

    Body temperature is an important parameter in medical practice, and most of health diagnoses are made based upon measured temperature values. Non-contact measurements are attractive to both patients and physicians, and ear thermometers (ET) are part of the set of infrared thermometers for medical applications. ETs sense the tympanic membrane temperature which best represents body temperature. They take advantage of the natural high effective emissivity cavity that is formed as radiation source. To calibrate or to check the performance of ETs, we designed a high-emissivity spherical cavity as a blackbody source which can be placed in a dry block oven. Although the blackbody cavity can have any shape, we decided to build it spherical because its effective emissivity can be easily calculated in a closed form. The cavity is made of Aluminum to take advantage of its high thermal conductivity while its inner side is covered with a black paint to increase the cavity effective emissivity. Based on paint emissivity measurements and the geometrical shape, we calculated that the cavity has an effective emissivity higher than 0.999. Blackbody temperature is measured with a calibrated contact thermometer placed inside the bottom wall of the cavity. We present the design of the cavity, the experimental setup, and results of three commercial ETs compared with this cavity.

  17. Design and construction of a gallium fixed-point blackbody at CENAM

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas G, D., E-mail: dcardena@cenam.mx [Centro Nacional de Metrologia, Km 4.5 Carretera a los Cues, El Marques, 76246 Santiago de Queretaro, Queretaro (Mexico)

    2015-07-01

    For temperatures below silver fixed-point defined by the International Temperature Scale of 1990, a transfer radiation thermometer can be calibrated using either of two calibration schemes: a variable temperature blackbody with a standard platinum resistance thermometer as a reference, or with a set of fixed-point blackbodies. CENAM is presently working with the first scheme, and it is developing fixed-point blackbodies to have the capability to work with the second scheme too. For this purpose a gallium fixed-point blackbody to calibrate CENAM transfer radiation thermometer was designed and constructed. The blackbody cavity has a cylinder-cone shape with effective emissivity equal to 0.9992±0.0004 in the 8 μm to 14 μm wavelength range. The radiance temperature of the gallium fixed-point blackbody was estimated to have and expanded uncertainty of 54 m K, with a coverage factor k = 2. (Author)

  18. Design and performance evaluation of low-temperature vacuum blackbody system

    International Nuclear Information System (INIS)

    In this paper, the design concept of a low-temperature vacuum blackbody was described, and thermophysical model of the blackbody was numerically evaluated. Also the working performance of low-temperature vacuum blackbody was evaluated using infrared camera system. The blackbody system was constructed to operate under high-vacuum conditions (2.67x10-2 Pa) to reduce temperature uncertainty, which is caused by vapor condensation at low temperatures usually below 273 K. In addition, both heat sink and heat shield including cold shield were installed around radiator to prevent heat loss from the blackbody. Simplified mathematical model of blackbody radiator was analyzed using modified Stefan-Boltzmann's rule. The infrared radiant performance of the blackbody was evaluated using infrared camera. Based on the results of measurements, and simulation, temperature stability of the low-temperature vacuum blackbody demonstrated that the blackbody system can serve as a highly stable reference source for the calibration of an infrared optical system.

  19. Spectral emissivity of surface blackbody calibrators

    DEFF Research Database (Denmark)

    Clausen, Sønnik

    2007-01-01

    The normal spectral emissivity of commercial infrared calibrators is compared with measurements of anodized aluminum samples and grooved aluminum surfaces coated with Pyromark. Measurements performed by FTIR spectroscopy in the wavelength interval from 2 to 20 mu m and at temperatures between 5...... and 550 degrees C are presented with absolute uncertainties from 0.25% to 1% in spectral regions with sufficient signal and no significant atmospheric gas absorption. A large variation in emissivity with wavelength is observed for some surfaces, i.e., from 1% to 3% to more than 10%. The variation...... in emissivity using similar materials can be reduced to 0.5-1% by optimizing the coating process and the surface geometry. Results are discussed and an equation for calculation of the equivalent blackbody surface temperature from FTIR spectra is presented, including reflected ambient radiation. It is in most...

  20. Numerical Models of Blackbody-Dominated GRBs

    CERN Document Server

    Cuesta-Martínez, Carlos F; Mimica, Petar; Thöne, Christina C; de Ugarte-Postigo, Antonio

    2015-01-01

    Blackbody-dominated (BBD) gamma-ray bursts (GRBs) are events characterized by the absence of a typical afterglow, long durations and the presence of a significant thermal component following the prompt gamma-ray emission. GRB 101225A (the `Christmas burst') is a prototype of this class. A plausible progenitor system for it, and for the BBD-GRBs, is the merger of a neutron star (NS) and a helium core of an evolved, massive star. Using relativistic hydrodynamic simulations we model the propagation of an ultrarelativistic jet through the enviroment created by such a merger and we compute the whole radiative signature, both thermal and non-thermal, of the jet dynamical evolution. We find that the thermal emission originates from the interaction between the jet and the hydrogen envelope ejected during the NS/He merger.

  1. Solar powered blackbody-pumped lasers

    Science.gov (United States)

    Christiansen, Walter H.; Sirota, J. M.

    1991-02-01

    A concept for a solar-powered laser is presented which utilizes an intermediate blackbody cavity to provide a uniform optical pumping environment for the lasant, typically CO or CO2 or possibly a solid state laser medium. High power cw blackbody- pumped lasers with efficiencies on the order of 20 percent or more are feasible. The physical basis of this idea is reviewed. Small scale experiments using a high temperature oven as the optical pump have been carried out with gas laser mixtures. Detailed calculations showing a potential efficiency of 35 percent for blackbody pumped Nd:YAG system are discussed.

  2. A small-size transfer blackbody cavity for calibration of infrared ear thermometers

    International Nuclear Information System (INIS)

    A small-size transfer blackbody cavity for calibration of infrared ear thermometers (IRETs) was developed and characterized at the Korea Research Institute of Standards and Science. This blackbody cavity consists of a reflector exposed to the air and a radiator with three-step curves immersed in a water-bath, and has an angularly uniform emissivity of higher than 0.9993. The radiance temperature of the blackbody cavity was measured with an IRET. We also calculated the effective emissivity by using the software STEEP322, considering the influence of the shape and temperature of the probe-tip of the IRET on the effective emissivity of the blackbody cavity. The measured and calculated radiance temperatures of the blackbody cavity were compared to those of the ASTM-type blackbody cavity and are in good agreement. Uncertainties (k = 1) of the blackbody cavity are estimated to be less than 44 mK in the temperature range 35–42 °C. (paper)

  3. Wideband filter radiometers for blackbody temperature measurements

    Science.gov (United States)

    Boivin, L. P.; Bamber, C.; Gaertner, A. A.; Gerson, R. K.; Woods, D. J.; Woolliams, E. R.

    2010-10-01

    The use of high-temperature blackbody (HTBB) radiators to realize primary spectral irradiance scales requires that the operating temperature of the HTBB be accurately determined. We have developed five filter radiometers (FRs) to measure the temperature of the National Research Council of Canada's HTBB. The FRs are designed to minimize sensitivity to ambient temperature fluctuations. They incorporate air-spaced colored glass filters and a Si photodiode detector that are housed in a cell whose temperature is controlled to ±0.1°C by means of annular thermoelectric elements at the front and rear of the cell. These wideband filter radiometers operate in four different wavelength bands. The spectral responsivity measurements were performed in an underfill geometry for a power-mode calibration that is traceable to NRC's cryogenic radiometer. The spectral temperature sensitivity of each of these FRs has been measured. The apertures for these FRs were cold-formed by swaging machine-cut apertures onto precision dowel pins. A description of the filter radiometer design, fabrication and testing, together with a detailed uncertainty analysis, is presented. We derive the equations that relate the spectral irradiance measured by the FRs to the spectral radiance and temperature of the HTBB, and deal specifically with the change of index of refraction over the path of the radiation from the interior of the HTBB to the FRs. We believe these equations are more accurate than recently published derivations. Our measurements of the operating temperature of our HTBB working at temperatures near 2500 K, 2700 K and 2900 K, together with measurements using a pyrometer, show agreement between the five filter radiometers and with the pyrometer to within the estimated uncertainties.

  4. Amplitude-Squared Squeezing in a Kerr-Nonlinear Blackbody

    Institute of Scientific and Technical Information of China (English)

    WU Zi-Xia; CHENG Ze; ZHANG Yan-Min; CHENG Zheng-Ze

    2007-01-01

    We find that amplitude-squared squeezing of the photon field is present in a new blackbody, namely, a Kerrnonlinear blackbody. The squeezing effect decreases as temperature T increases. The amount of the amplitude-squared squeezing in a Kerr-nonlinear blackbody is much larger than the corresponding squeezing in normal blackbody, and the degree of amplitude-squared squeezing is much larger than the amplitude squeezing for the same range of parameters in a Kerr-nonlinear blackbody.

  5. Thermodynamic properties of a Kerr nonlinear blackbody.

    Science.gov (United States)

    Cheng, Ze

    2012-11-01

    Within the framework of quantum field theory, we present the superfluid state of photons in a blackbody whose interior is filled by a Kerr nonlinear crystal. The thermodynamic properties of a Kerr nonlinear blackbody are investigated. At the transition temperature, the Gibbs free energy of the two phases is continuous but the entropy density of the two phases is discontinuous. Hence, there is a jump in the entropy density and this leads to a latent heat density. The photon system undergoes a first-order phase transition from the normal to the superfluid state. The transition temperature is characteristic of a concrete crystal. The entropy density and specific heat capacity are monotonically increasing functions of the temperature but are monotonically decreasing functions of the Kerr nonlinear coefficient. PMID:23214733

  6. Comparison of Blackbodies for Calibration of Infrared Ear Thermometers

    DEFF Research Database (Denmark)

    Pušnik, Igor; Clausen, Sønnik; Favreau, Jacques-Olivier;

    2011-01-01

    The article presents the results of the EURAMET Project No. 927 “Comparison of blackbodies for calibration of infrared ear thermometers (IRETs)”. The objective of the comparison was to determine the agreement of blackbodies used for the calibration of IRETs among European national laboratories....... To verify the accuracy of an IRET, a suitable blackbody (BB) is needed. Such a blackbody related to the EN standard, designed for the calibration of ear thermometers and immersed in a stirred water bath, was provided for the comparison by the pilot laboratory. The pilot provided also the transfer IRET...

  7. The Planck Blackbody Spectrum Follows from the Structure of Relativistic Spacetime

    CERN Document Server

    Boyer, Timothy H

    2016-01-01

    Here we show that within classical physics, the Planck blackbody spectrum can be derived directly from the structure of relativistic spacetime. In noninertial frames, thermal radiation at positive temperature is connected directly to zero-point radiation whose spectrum follows from the geodesic structure of the spacetime. The connection between zero-point radiation and thermal radiation at postive temperature is through a time-dilating conformal transformation in the noninertial frame. Transferring the spectrum back to Minskowski spacetime, the Planck spectrum is obtained.

  8. mbb_emcee: Modified Blackbody MCMC

    Science.gov (United States)

    Conley, Alexander

    2016-02-01

    Mbb_emcee fits modified blackbodies to photometry data using an affine invariant MCMC. It has large number of options which, for example, allow computation of the IR luminosity or dustmass as part of the fit. Carrying out a fit produces a HDF5 output file containing the results, which can either be read directly, or read back into a mbb_results object for analysis. Upper and lower limits can be imposed as well as Gaussian priors on the model parameters. These additions are useful for analyzing poorly constrained data. In addition to standard Python packages scipy, numpy, and cython, mbb_emcee requires emcee (ascl:1303.002), Astropy (ascl:1304.002), h5py, and for unit tests, nose.

  9. Mixing of blackbodies: entropy production and dissipation of sound waves in the early Universe

    OpenAIRE

    Khatri, Rishi; Sunyaev, Rashid A.; Chluba, Jens

    2012-01-01

    Mixing of blackbodies with different temperatures creates a spectral distortion which, at lowest order, is a y-type distortion, indistinguishable from the thermal y-type distortion produced by the scattering of CMB photons by hot electrons residing in clusters of galaxies. This process occurs in the radiation-pressure dominated early Universe, when the primordial perturbations excite standing sound waves on entering the sound horizon. Photons from different phases of the sound waves, having d...

  10. Black-body laws derived from a minimum knowledge of Physics

    OpenAIRE

    A. G. AgneseINFN; La Camera, M.; E. Recami(INFN)

    2015-01-01

    Starting from the knowledge of the four fundamental quantities length L, mass M, time T, absolute temperature $\\theta$ and accepting the validity of Gauss's law in all dimensions, we generalize, by the theory of physical dimensions, the expression of the Stephan-Boltzmann law and of the Planck's formula for the black-body radiation to a spacetime with one time and n spatial coordinates. In the particular case n=3 we shall recover the known results.

  11. Mixing of blackbodies: entropy production and dissipation of sound waves in the early Universe

    Science.gov (United States)

    Khatri, R.; Sunyaev, R. A.; Chluba, J.

    2012-07-01

    Mixing of blackbodies with different temperatures creates a spectral distortion which, at lowest order, is a y-type distortion, indistinguishable from the thermal y-type distortion produced by the scattering of cosmic microwave background (CMB) photons by hot electrons residing in clusters of galaxies. This process occurs in the radiation-pressure dominated early Universe, when the primordial perturbations excite standing sound waves on entering the sound horizon. Photons from different phases of the sound waves, having different temperatures, diffuse through the electron-baryon plasma and mix together. This diffusion, with the length defined by Thomson scattering, dissipates sound waves and creates spectral distortions in the CMB. Of the total dissipated energy, 2/3 raises the average temperature of the blackbody part of spectrum, while 1/3 creates a distortion of y-type. It is well known that at redshifts 105 ≲ z ≲ 2 × 106, comptonization rapidly transforms y-distortions into a Bose-Einstein spectrum. The chemical potential of the Bose-Einstein spectrum is again 1/3 the value we would get if all the dissipated energy was injected into a blackbody spectrum but no extra photons were added. We study the mixing of blackbody spectra, emphasizing the thermodynamic point of view, and identifying spectral distortions with entropy creation. This allows us to obtain the main results connected with the dissipation of sound waves in the early Universe in a very simple way. We also show that mixing of blackbodies in general, and dissipation of sound waves in particular, leads to creation of entropy.

  12. Reexamining Black-Body Shifts for Hydrogenlike Ions

    OpenAIRE

    Jentschura, U. D.; Haas, M.

    2008-01-01

    We investigate black-body induced energy shifts for low-lying levels of atomic systems, with a special emphasis on transitions used in current and planned high-precision experiments on atomic hydrogen and ionized helium. Fine-structure and Lamb-shift induced black-body shifts are found to increase with the square of the nuclear charge number, whereas black-body shifts due to virtual transitions decrease with increasing nuclear charge as the fourth power of the nuclear charge. We also investig...

  13. Improved Blackbody Temperature Sensors for a Vacuum Furnace

    Science.gov (United States)

    Farmer, Jeff; Coppens, Chris; O'Dell, J. Scott; McKechnie, Timothy N.; Schofield, Elizabeth

    2009-01-01

    Some improvements have been made in the design and fabrication of blackbody sensors (BBSs) used to measure the temperature of a heater core in a vacuum furnace. Each BBS consists of a ring of thermally conductive, high-melting-temperature material with two tantalum-sheathed thermocouples attached at diametrically opposite points. The name "blackbody sensor" reflects the basic principle of operation. Heat is transferred between the ring and the furnace heater core primarily by blackbody radiation, heat is conducted through the ring to the thermocouples, and the temperature of the ring (and, hence, the temperature of the heater core) is measured by use of the thermocouples. Two main requirements have guided the development of these BBSs: (1) The rings should have as high an emissivity as possible in order to maximize the heat-transfer rate and thereby maximize temperature-monitoring performance and (2) the thermocouples must be joined to the rings in such a way as to ensure long-term, reliable intimate thermal contact. The problem of fabricating a BBS to satisfy these requirements is complicated by an application-specific prohibition against overheating and thereby damaging nearby instrumentation leads through the use of conventional furnace brazing or any other technique that involves heating the entire BBS and its surroundings. The problem is further complicated by another application-specific prohibition against damaging the thin tantalum thermocouple sheaths through the use of conventional welding to join the thermocouples to the ring. The first BBS rings were made of graphite. The tantalum-sheathed thermocouples were attached to the graphite rings by use of high-temperature graphite cements. The ring/thermocouple bonds thus formed were found to be weak and unreliable, and so graphite rings and graphite cements were abandoned. Now, each BBS ring is made from one of two materials: either tantalum or a molybdenum/titanium/zirconium alloy. The tantalum

  14. Frequency shift due to blackbody radiation in a cesium atomic fountain and improvement of the clock performances; Deplacement de frequence du au rayonnement du corps noir dans une fontaine atomique a cesium et amelioration des performances de l'horloge

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S

    2004-07-01

    FO1 was the first caesium fountain primary frequency standard in the world. The most recent evaluation in 2002 before improvement reached an accuracy of 1*10{sup -15} when operated with optical molasses. Working as an extremely precise and stable instrument, FO1 has contributed to fundamental physics and technical measurements: - Frequency comparison between Cs and Rb fountains over an interval of 5 years sets an upper limit for a possible variation of the fine structure constant as |alpha/alpha| < 2*10{sup -15}/y. The resolution is about 5 times better than the previous test in our laboratory. The projected accuracy of the space clock PHARAO is 1*10{sup -16}. We confirmed its Ramsey cavity performance by testing the phase difference between the two interaction zones in FO1. The measured temperature T dependent frequency shift of the Cs clock induced by the blackbody radiation field is given as nu(T)=154(6)*10{sup -6}*(T/300){sup 4}[1+{epsilon}(T/300){sup 2}] Hz with the theoretical value {epsilon} = 0,014. The obtained accuracy represents a 3 times improvement over the previous measurement by the PTB group. Some improvements have been carried out on FO1. The new FO1 version works directly with optical molasses loaded by a laser slowed atomic beam. The application of the adiabatic passage method to perform the state selection allows us to determine the atom number dependent frequency shifts due to the cold collision and cavity pulling effects at a level of of 10{sup -16}. Recently, the obtained frequency stability is 2,8*10{sup -14}*{tau}{sup -1/2} for about 4*10{sup 6} detected atoms. The accuracy is currently under evaluation, the expected value is a few times 10{sup -16}. (author)

  15. Design, manufacture, and calibration of infrared radiometric blackbody sources

    Energy Technology Data Exchange (ETDEWEB)

    Byrd, D.A.; Michaud, F.D.; Bender, S.C. [and others

    1996-04-01

    A Radiometric Calibration Station (RCS) is being assembled at the Los Alamos National Laboratories (LANL) which will allow for calibration of sensors with detector arrays having spectral capability from about 0.4-15 {mu}m. The configuration of the LANL RCS. Two blackbody sources have been designed to cover the spectral range from about 3-15 {mu}m, operating at temperatures ranging from about 180-350 K within a vacuum environment. The sources are designed to present a uniform spectral radiance over a large area to the sensor unit under test. The thermal uniformity requirement of the blackbody cavities has been one of the key factors of the design, requiring less than 50 mK variation over the entire blackbody surface to attain effective emissivity values of about 0.999. Once the two units are built and verified to the level of about 100 mK at LANL, they will be sent to the National Institute of Standards and Technology (NIST), where at least a factor of two improvement will be calibrated into the blackbody control system. The physical size of these assemblies will require modifications of the existing NIST Low Background Infrared (LBIR) Facility. LANL has constructed a bolt-on addition to the LBIR facility that will allow calibration of our large aperture sources. Methodology for attaining the two blackbody sources at calibrated levels of performance equivalent to present state of the art will be explained in the following.

  16. An atomic clock with $1\\times 10^{-18}$ room-temperature blackbody Stark uncertainty

    CERN Document Server

    Beloy, K; Phillips, N B; Sherman, J A; Schioppo, M; Lehman, J; Feldman, A; Hanssen, L M; Oates, C W; Ludlow, A D

    2014-01-01

    The Stark shift due to blackbody radiation (BBR) is the key factor limiting the performance of many atomic frequency standards, with the BBR environment inside the clock apparatus being difficult to characterize at a high level of precision. Here we demonstrate an in-vacuum radiation shield that furnishes a uniform, well-characterized BBR environment for the atoms in an ytterbium optical lattice clock. Operated at room temperature, this shield enables specification of the BBR environment to a corresponding fractional clock uncertainty contribution of $5.5 \\times 10^{-19}$. Combined with uncertainty in the atomic response, the total uncertainty of the BBR Stark shift is now $1\\times10^{-18}$. Further operation of the shield at elevated temperatures enables a direct measure of the BBR shift temperature dependence and demonstrates consistency between our evaluated BBR environment and the expected atomic response.

  17. Research of optimizing the microwave wide band blackbody calibration target

    Institute of Scientific and Technical Information of China (English)

    Nian Feng; Yang Yujie; Wang Wei

    2009-01-01

    The blackbody calibration targets applied for microwave radiometer's prelauneh calibration are opti-mized with its electromagnetic and thermal characteristics. Based on the method of emissivity optimization with radar cross section (RCS) simulation and the method of subgrid finite difference time domain (FDTD), the following design rules are summarized: that the round wedge is better than the square one, the best ratio from height to bottom radius is 4:1, for wide band calibration, the multilayer absorbing material coating is efficient to increase the emissivity, and the gradual thickness absorbing material coating is helpful to guarantee the uniform distribution of surface temperature even as it keeps a higher emissivity. Finally following the above conclusions, a new type of blackbody calibration target with the cellular array is preferred to improve the uniformity of polarization, which will increase the performance of the calibration targets further.

  18. Signal verification with blackbody photons for the Fermilab Holometer

    Science.gov (United States)

    Kamai, Brittany

    2014-03-01

    The Holometer, an instrument that consists of two proximate power-recycled laser interferometers, is used to test for the presence of a new type of position noise. The predicted noise signal, from a quantum-geometrical theory, is that two interferometers can measure correlated position noise in the light output of the each interferometer. Verification of the ability to correctly detect small correlations in a noisy signal can be done using blackbody photons passing through a beamsplitter. The correlated intensity variations from a blackbody emitter will be used to test the Holometer photodiodes, electronics and front-end software. We will describe the verification equipment and procedure. Science runs for the Holometer will commence in early 2015.

  19. Scale effect of Planck’ s law over nonisothermal blackbody surface

    Institute of Scientific and Technical Information of China (English)

    李小文; 王锦地; A.; H.; Strahler

    1999-01-01

    Many physical laws, principles, models, measurement methods, etc., are applicable only to either a point on surface or a homogeneous surface. However, remote sensing deals with pixels which may range from meters to kilometers. Therefore scale effects of these laws and measurements are inevitable problems which must be faced. As an example, the spatial scale effect of Planck Law over nonisothermal blackbody surface is considered.

  20. Blackbody absorption efficiencies for six lamp pumped Nd laser materials

    Science.gov (United States)

    Cross, Patricia L.; Barnes, Norman P.; Skolaut, Milton W., Jr.; Storm, Mark E.

    1990-01-01

    Utilizing high resolution spectra, the absorption efficiencies for six Nd laser materials were calculated as functions of the effective blackbody temperature of the lamp and laser crystal size. The six materials were Nd:YAG, Nd:YLF, Nd:Q-98 Glass, Nd:YVO4, Nd:BEL, and Nd:Cr:GSGG. Under the guidelines of this study, Nd:Cr:GSGG's absorption efficiency is twice the absorption efficiency of any of the other laser materials.

  1. Comparison of blackbodies for calibration of infrared ear thermometers

    DEFF Research Database (Denmark)

    Pusnik, Igor; Clausen, Sønnik; Favreau, Jacques-Olivier;

    2010-01-01

    The article will present the results of the EURAMET project no. 927 "Comparison of blackbodies for calibration of infrared ear thermometers (IRETs)". For the comparison MIRS/UL-FE LMK was chosen as the pilot laboratory. The objective of the comparison was to determine the agreement of blackbodies...... this is the standard EN 12470-5, which is a harmonised standard and supports the Medical Device Directive (MDD). Other standards are ASTM standard, Designation E 1965 – 98 and the draft of Japan Industrial Standard JIS T 4207, 2005: Japanese Industrial Standard: “infrared ear thermometers.”. The International...... Organization for Standardization (ISO) is developing a new standard for clinical thermometers, which will include also IRETs. The basic requirement for accuracy in EN 12470-5 is that the maximum permissible error of IRET is ±0,2 °C in the range from 35,5 °C to 42,0 °C, while the uncertainty of a blackbody...

  2. Creation of the CMB blackbody spectrum: precise analytic solutions

    CERN Document Server

    Khatri, Rishi

    2012-01-01

    The blackbody spectrum of CMB was created behind the blackbody surface at redshifts $z\\gtrsim 2\\times 10^6$. At earlier times, the Universe was dense and hot enough that complete thermal equilibrium between baryonic matter (electrons and ions) and photons could be established. Any perturbation away from the blackbody spectrum was suppressed exponentially. New physics, for example annihilation and decay of dark matter, can add energy and photons to CMB at redshifts $z\\gtrsim 10^5$ and result in a non-zero chemical potential ($\\mu$) of CMB. Precise evolution of the CMB spectrum around the critical redshift of $z\\gtrsim 2\\times 10^6$ is required in order to calculate the $\\mu$-type spectral distortion. Although numerical calculation of important processes involved (double Compton process, comptonization and bremsstrahlung) is not difficult, analytic solutions are much faster and easier to calculate and provide valuable physical insights. We provide precise (better than 1%) analytic solutions for the decay of $\\m...

  3. Mixing of blackbodies: entropy production and dissipation of sound waves in the early Universe

    CERN Document Server

    Khatri, Rishi; Chluba, Jens

    2012-01-01

    Mixing of blackbodies with different temperatures creates a spectral distortion which, at lowest order, is a y-type distortion, indistinguishable from the thermal y-type distortion produced by the scattering of CMB photons by hot electrons residing in clusters of galaxies. This process occurs in the radiation-pressure dominated early Universe, when the primordial perturbations excite standing sound waves on entering the sound horizon. Photons from different phases of the sound waves, having different temperatures, diffuse through the electron-baryon plasma and mix together. This diffusion, with the length defined by Thomson scattering, dissipates sound waves and creates spectral distortions in the CMB. Of the total dissipated energy, 2/3 raises the average temperature of the blackbody part of spectrum, while 1/3 creates a distortion of y-type. It is well known that at redshifts 10^5< z< 2x10^6, comptonization rapidly transforms y-distortions into a Bose-Einstein spectrum. The chemical potential of the B...

  4. A Physically Based Algorithm for Non-Blackbody Correction of Cloud-Top Temperature and Application to Convection Study

    Science.gov (United States)

    Wang, Chunpeng; Lou, Zhengzhao Johnny; Chen, Xiuhong; Zeng, Xiping; Tao, Wei-Kuo; Huang, Xianglei

    2014-01-01

    Cloud-top temperature (CTT) is an important parameter for convective clouds and is usually different from the 11-micrometers brightness temperature due to non-blackbody effects. This paper presents an algorithm for estimating convective CTT by using simultaneous passive [Moderate Resolution Imaging Spectroradiometer (MODIS)] and active [CloudSat 1 Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)] measurements of clouds to correct for the non-blackbody effect. To do this, a weighting function of the MODIS 11-micrometers band is explicitly calculated by feeding cloud hydrometer profiles from CloudSat and CALIPSO retrievals and temperature and humidity profiles based on ECMWF analyses into a radiation transfer model.Among 16 837 tropical deep convective clouds observed by CloudSat in 2008, the averaged effective emission level (EEL) of the 11-mm channel is located at optical depth; approximately 0.72, with a standard deviation of 0.3. The distance between the EEL and cloud-top height determined by CloudSat is shown to be related to a parameter called cloud-top fuzziness (CTF), defined as the vertical separation between 230 and 10 dBZ of CloudSat radar reflectivity. On the basis of these findings a relationship is then developed between the CTF and the difference between MODIS 11-micrometers brightness temperature and physical CTT, the latter being the non-blackbody correction of CTT. Correction of the non-blackbody effect of CTT is applied to analyze convective cloud-top buoyancy. With this correction, about 70% of the convective cores observed by CloudSat in the height range of 6-10 km have positive buoyancy near cloud top, meaning clouds are still growing vertically, although their final fate cannot be determined by snapshot observations.

  5. CMB all-scale blackbody distortions induced by linearizing temperature

    Science.gov (United States)

    Notari, Alessio; Quartin, Miguel

    2016-08-01

    Cosmic microwave background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a linearized formula for relating them to the temperature blackbody fluctuations. However, this procedure also generates a signal in the maps in the form of y -type distortions which is degenerate with the thermal Sunyaev Zel'dovich (tSZ) effect. These are small effects that arise at second order in the temperature fluctuations not from primordial physics but from such a limitation of the map-making procedure. They constitute a contaminant for measurements of our peculiar velocity, the tSZ and primordial y -distortions. They can nevertheless be well modeled and accounted for. We show that the distortions arise from a leakage of the CMB dipole into the y -channel which couples to all multipoles, mostly affecting the range ℓ≲400 . This should be visible in Planck's y -maps with an estimated signal-to-noise ratio of about 12. We note however that such frequency-dependent terms carry no new information on the nature of the CMB dipole. This implies that the real significance of Planck's Doppler coupling measurements is actually lower than reported by the collaboration. Finally, we quantify the level of contamination in tSZ and primordial y -type distortions and show that it is above the sensitivity of proposed next-generation CMB experiments.

  6. CMB all-scale blackbody distortions induced by linearizing temperature

    CERN Document Server

    Notari, Alessio

    2016-01-01

    Cosmic Microwave Background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a \\emph{linearized} formula for relating them to the temperature blackbody fluctuations. However such a procedure also generates a signal in the maps in the form of y-type distortions, and thus degenerate with the thermal SZ (tSZ) effect. These are small effects that arise at second-order in the temperature fluctuations not from primordial physics but from such a limitation of the map-making procedure. They constitute a contaminant for measurements of: our peculiar velocity, the tSZ and of primordial y-distortions, but they can nevertheless be well-modelled and accounted for. We show that the largest distortions arises at high ell from a leakage of the CMB dipole into the y-channel which couples to all multipoles, but mostly affects the range ell <~ 400. This should be visible in Planck's y-maps with an estimated signal-to-noise ratio of about 9. We note however that such frequency-de...

  7. Thermal Equilibrium Between Radiation and Matter: A Lead to the Maxwell-Boltzmann and Planck Distributions

    Science.gov (United States)

    Lanyi, Gabor E.

    2003-01-01

    This viewgraph presentation reviews the 1901 work in Planck's constant and blackbody radiation law and the 1916 Einstein rederivation of the blackbody radiation law. It also reviews Wien's law. It also presents equations that demonstrate the thermal balance between radiation and matter.

  8. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  9. Sensitivity of blackbody effective emissivity to wavelength and temperature: By genetic algorithm

    International Nuclear Information System (INIS)

    A variable-temperature blackbody (VTBB) is used to calibrate an infrared radiation thermometer (pyrometer). The effective emissivity (εeff) of a VTBB is dependent on temperature and wavelength other than the geometry of the VTBB. In the calibration process the effective emissivity is often assumed to be constant within the wavelength and temperature range. There are practical situations where the sensitivity of the effective emissivity needs to be known and correction has to be applied. We present a method using a genetic algorithm to investigate the sensitivity of the effective emissivity to wavelength and temperature variation. Two matlab® programs are generated: the first to model the radiance temperature calculation and the second to connect the model to the genetic algorithm optimization toolbox. The effective emissivity parameter is taken as a chromosome and optimized at each wavelength and temperature point. The difference between the contact temperature (reading from a platinum resistance thermometer or liquid in glass thermometer) and radiance temperature (calculated from the εeff values) is used as an objective function where merit values are calculated and best fit εeff values selected. The best fit εeff values obtained as a solution show how sensitive they are to temperature and wavelength parameter variation. Uncertainty components that arise from wavelength and temperature variation are determined based on the sensitivity analysis. Numerical examples are considered for illustration

  10. Sensitivity of blackbody effective emissivity to wavelength and temperature: By genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Ejigu, E. K.; Liedberg, H. G. [National Metrology Institute of South Africa (NMISA), Private Bag X34, Lynnwood Ridge, Pretoria, 0040 (South Africa)

    2013-09-11

    A variable-temperature blackbody (VTBB) is used to calibrate an infrared radiation thermometer (pyrometer). The effective emissivity (ε{sub eff}) of a VTBB is dependent on temperature and wavelength other than the geometry of the VTBB. In the calibration process the effective emissivity is often assumed to be constant within the wavelength and temperature range. There are practical situations where the sensitivity of the effective emissivity needs to be known and correction has to be applied. We present a method using a genetic algorithm to investigate the sensitivity of the effective emissivity to wavelength and temperature variation. Two matlab® programs are generated: the first to model the radiance temperature calculation and the second to connect the model to the genetic algorithm optimization toolbox. The effective emissivity parameter is taken as a chromosome and optimized at each wavelength and temperature point. The difference between the contact temperature (reading from a platinum resistance thermometer or liquid in glass thermometer) and radiance temperature (calculated from the ε{sub eff} values) is used as an objective function where merit values are calculated and best fit ε{sub eff} values selected. The best fit ε{sub eff} values obtained as a solution show how sensitive they are to temperature and wavelength parameter variation. Uncertainty components that arise from wavelength and temperature variation are determined based on the sensitivity analysis. Numerical examples are considered for illustration.

  11. Onboard Blackbody Calibrator Component Development for IR Remote Sensing Instrumentation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We plan to develop a blackbody coated with Carbon nanotube materials that will able to operate in the temperature ranges need to calibrate a thermal infrared sensor...

  12. Induced radiation processes in single-bubble sonoluminescence

    OpenAIRE

    Prigara, Fedor V.

    2005-01-01

    According to the recent revision of the theory of thermal radiation, thermal black-body radiation has an induced origin. We show that in single-bubble sonoluminescence thermal radiation is emitted by a spherical resonator, coincident with the sonoluminescing bubble itself, instead of the ensemble of elementary resonators emitting thermal black-body radiation in the case of open gaseous media. For a given wavelength, the diameter of the resonator is fixed, and this explains the very high const...

  13. Analytic evaluation of the weighting functions for remote sensing of blackbody planetary atmospheres : the case of limb viewing geometry

    Science.gov (United States)

    Ustinov, Eugene A.

    2006-01-01

    In a recent publication (Ustinov, 2002), we proposed an analytic approach to evaluation of radiative and geophysical weighting functions for remote sensing of a blackbody planetary atmosphere, based on general linearization approach applied to the case of nadir viewing geometry. In this presentation, the general linearization approach is applied to the limb viewing geometry. The expressions, similar to those obtained in (Ustinov, 2002), are obtained for weighting functions with respect to the distance along the line of sight. Further on, these expressions are converted to the expressions for weighting functions with respect to the vertical coordinate in the atmosphere. Finally, the numerical representation of weighting functions in the form of matrices of partial derivatives of grid limb radiances with respect to the grid values of atmospheric parameters is used for a convolution with the finite field of view of the instrument.

  14. Theoretical realization of robust broadband transparency in ultrathin seamless nanostructures by dual blackbodies for near infrared light

    Science.gov (United States)

    Zhang, Lei; Hao, Jiaming; Ye, Huapeng; Yeo, Swee Ping; Qiu, Min; Zouhdi, Said; Qiu, Cheng-Wei

    2013-03-01

    We propose a counter-intuitive mechanism of constructing an ultrathin broadband transparent device with two perfect blackbodies. By introducing hybridization of plasmon modes, resonant modes with different symmetries coexist in this system. A broadband transmission spectrum in the near infrared regime is achieved through controlling their coupling strengths, which is governed by the thickness of high refractive index layer. Meanwhile, the transparency bandwidth is found to be tunable in a large range by varying the geometric dimension. More significantly, from the point view of applications, the proposed method of achieving broadband transparency can perfectly tolerate the misalignment and asymmetry of periodic nanoparticles on the top and bottom, which is empowered by the unique dual of coupling-in and coupling-out processes within the pair of blackbodies. Moreover, roughness has little influence on its transmission performance. According to the coupled mode theory, the distinguished transmittance performance is physically interpreted by the radiative decay rate of the entire system. In addition to the feature of uniquely robust broadband transparency, such a ultrathin seamless nanostructure (in the presence of a uniform silver layer) also provides polarization-independent and angle-independent operations. Therefore, it may power up a wide spectrum of exciting applications in thin film protection, touch screen techniques, absorber-emitter transformation, etc.We propose a counter-intuitive mechanism of constructing an ultrathin broadband transparent device with two perfect blackbodies. By introducing hybridization of plasmon modes, resonant modes with different symmetries coexist in this system. A broadband transmission spectrum in the near infrared regime is achieved through controlling their coupling strengths, which is governed by the thickness of high refractive index layer. Meanwhile, the transparency bandwidth is found to be tunable in a large range by

  15. Effective emissivity of a blackbody cavity formed by two coaxial tubes.

    Science.gov (United States)

    Mei, Guohui; Zhang, Jiu; Zhao, Shumao; Xie, Zhi

    2014-04-10

    A blackbody cavity is developed for continuously measuring the temperature of molten steel, which consists of a cylindrical outer tube with a flat bottom, a coaxial inner tube, and an aperture diaphragm. The ray-tracing approach based on the Monte Carlo method was applied to calculate the effective emissivity for the isothermal cavity with the diffuse walls. And the dependences of the effective emissivity on the inner tube relative length were calculated for various inner tube radii, outer tube lengths, and wall emissivities. Results indicate that the effective emissivity usually has a maximum corresponding to the inner tube relative length, which can be explained by the impact of the inner tube relative length on the probability of the rays absorbed after two reflections. Thus, these results are helpful to the optimal design of the blackbody cavity.

  16. Effective emissivity of a blackbody cavity formed by two coaxial tubes.

    Science.gov (United States)

    Mei, Guohui; Zhang, Jiu; Zhao, Shumao; Xie, Zhi

    2014-04-10

    A blackbody cavity is developed for continuously measuring the temperature of molten steel, which consists of a cylindrical outer tube with a flat bottom, a coaxial inner tube, and an aperture diaphragm. The ray-tracing approach based on the Monte Carlo method was applied to calculate the effective emissivity for the isothermal cavity with the diffuse walls. And the dependences of the effective emissivity on the inner tube relative length were calculated for various inner tube radii, outer tube lengths, and wall emissivities. Results indicate that the effective emissivity usually has a maximum corresponding to the inner tube relative length, which can be explained by the impact of the inner tube relative length on the probability of the rays absorbed after two reflections. Thus, these results are helpful to the optimal design of the blackbody cavity. PMID:24787424

  17. A simple blackbody simulator with several possibilities and applications on thermography

    Science.gov (United States)

    dos Santos, Laerte; Lemos, Alisson Maria; Abi-Ramia, Marco Antônio

    2016-05-01

    Originally designed to make the practical examination on thermography certification1 possible, the device presented in this paper has demonstrated to be a very useful and versatile didactic tool for training centers and educational institutions, it can also be used as a low cost blackbody simulator to verify calibration of radiometers. It is a simple device with several functionalities for studying and for applications on heat transfer and radiometry, among them the interesting ability to thermally simulate the surface of real objects. On that functionality, if the device is seen by a thermographic camera, it reproduces the surface apparent temperatures of the object that it is simulating, at the same time, if it is seen by a naked eye it shows a visible image of that same surface. This functionality makes the practical study in the classroom possible, from different areas such as electrical, mechanical, medical, building, veterinary, etc.

  18. Design and Calibration of a Cryogenic Blackbody Calibrator at Centimeter Wavelengths

    CERN Document Server

    Kogut, A J; Fixsen, D J; Limon, M; Mirel, P G A; Levin, S; Seiffert, M; Lubin, P M

    2004-01-01

    We describe the design and calibration of an external cryogenic blackbody calibrator used for the first two flights of the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) instrument. The calibrator consists of a microwave absorber weakly coupled to a superfluid liquid helium bath. Half-wave corrugations viewed 30 deg off axis reduce the return loss below -35 dB. Ruthenium oxide resistive thermometers embedded within the absorber monitor the temperature across the face of the calibrator. The thermal calibration transfers the calibration of a reference thermometer to the flight thermometers using the flight thermometer readout system. Data taken near the superfluid transition in 8 independent calibrations 4 years apart agree within 0.3 mK, providing an independent verification of the thermometer calibration at temperatures near that of the cosmic microwave background.

  19. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Mengüç, M Pinar

    2011-01-01

    Providing a comprehensive overview of the radiative behavior and properties of materials, the fifth edition of this classic textbook describes the physics of radiative heat transfer, development of relevant analysis methods, and associated mathematical and numerical techniques. Retaining the salient features and fundamental coverage that have made it popular, Thermal Radiation Heat Transfer, Fifth Edition has been carefully streamlined to omit superfluous material, yet enhanced to update information with extensive references. Includes four new chapters on Inverse Methods, Electromagnetic Theory, Scattering and Absorption by Particles, and Near-Field Radiative Transfer Keeping pace with significant developments, this book begins by addressing the radiative properties of blackbody and opaque materials, and how they are predicted using electromagnetic theory and obtained through measurements. It discusses radiative exchange in enclosures without any radiating medium between the surfaces-and where heat conduction...

  20. CMB all-scale blackbody distortions as a new tool to measure our peculiar velocity

    CERN Document Server

    Notari, Alessio

    2015-01-01

    We show that the Cosmic Microwave Background can be used to measure our peculiar velocity in a novel way, by looking at Doppler-induced distortions of the intensity blackbody spectrum which couple different multipoles. The frequency dependence of such a signal is called y-type, and is degenerate with the thermal SZ (tSZ) effect. Interestingly, like the kinetic Doppler quadrupole, its measurement is not limited by cosmic variance of the temperature spectrum; instead it only depends on experimental noise and on the small contamination due to the tSZ effect. Already with Planck this method yields a signal-to-noise ratio of about 9, and future experiments can increase this to somewhere around 15-40, and in principle even further if tSZ effect can be subtracted using data from clusters. Such a signal is present at all multipoles, but mostly in ell <~ 400, providing thus an independent way to measure our velocity that might also clarify the mixing between Doppler and a possible anomalous intrinsic dipolar modula...

  1. Uncertainty calculation of the effective emissivity of cylinder-conical blackbody cavities

    Science.gov (United States)

    De Lucas, Javier; Juan Segovia, José

    2016-02-01

    A numerical and geometrical model for calculating the local effective emissivity of isothermal blackbody cylinder-conical cavities with lid, assuming diffuse reflection, is described. This has been developed by generalizing previous models based on conical and cylindrical geometries. The model has been validated by determining the diffusely reflected photon trajectories and the corresponding experimental view factors between given pairs of surface elements. Differences compared to theoretical values, were subsequently analyzed in terms of the model’s intrinsic uncertainty. A well-defined numerical function that calculates the effective emissivity as a function of its natural variables, intrinsic emissivity and geometrical parameters, is established. In order to calculate the probability distribution of the output quantity, we use the Monte Carlo method for the propagation of the probability distributions that characterize our knowledge concerning the values of the influence variables. The model is applied to heat-pipe black bodies installed at our laboratory, previously characterized at the PTB. A comparison with published uncertainty results, obtained by applying classical uncertainty propagation techniques, is also made.

  2. Radiation

    International Nuclear Information System (INIS)

    The basic facts about radiation are explained, along with some simple and natural ways of combating its ill-effects, based on ancient healing wisdom as well as the latest biochemical and technological research. Details are also given of the diet that saved thousands of lives in Nagasaki after the Atomic bomb attack. Special comment is made on the use of radiation for food processing. (U.K.)

  3. Lecture on Thermal Radiation

    Science.gov (United States)

    Dennis, Brian R.

    2006-01-01

    This lecture will cover solar thermal radiation, particularly as it relates to the high energy solar processes that are the subject of this summer school. After a general review of thermal radiation from the Sun and a discussion of basic definitions, the various emission and absorption mechanisms will be described including black-body emission, bremsstrahlung, free-bound, and atomic line emissions of all kinds. The bulk of the time will be spent discussing the observational characteristics of thermal flare plasma and what can be learned about the flare energy release process from observations of the thermal radiation at all wavelengths. Information that has been learned about the morphology, temperature distribution, and composition of the flare plasma will be presented. The energetics of the thermal flare plasma will be discussed in relation to the nonthermal energy of the particles accelerated during the flare. This includes the total energy, the radiated and conductive cooling processes, and the total irradiated energy.

  4. Engineering absorption and blackbody radiation in the far-infrared with surface phonon polaritons on gallium phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Streyer, W.; Law, S.; Rosenberg, A.; Wasserman, D. [Department of Electrical and Computer Engineering, University of Illinois Urbana Champaign, Urbana, Illinois 61801 (United States); Roberts, C.; Podolskiy, V. A. [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States); Hoffman, A. J. [Department of Electrical Engineering, University of Notre Dame, South Bend, Indiana 46556 (United States)

    2014-03-31

    We demonstrate excitation of surface phonon polaritons on patterned gallium phosphide surfaces. Control over the light-polariton coupling frequencies is demonstrated by changing the pattern periodicity and used to experimentally determine the gallium phosphide surface phonon polariton dispersion curve. Selective emission via out-coupling of thermally excited surface phonon polaritons is experimentally demonstrated. Samples are characterized experimentally by Fourier transform infrared reflection and emission spectroscopy, and modeled using finite element techniques and rigorous coupled wave analysis. The use of phonon resonances for control of emissivity and excitation of bound surface waves offers a potential tool for the exploration of long-wavelength Reststrahlen band frequencies.

  5. Electronic modulation of infrared radiation in graphene plasmonic resonators

    OpenAIRE

    Brar, Victor W.; Sherrott, Michelle C.; Jang, Min Seok; Kim, Seyoon; Kim, Laura; Choi, Mansoo; Sweatlock, Luke A.; Atwater, Harry A.

    2015-01-01

    All matter at finite temperatures emits electromagnetic radiation due to the thermally induced motion of particles and quasiparticles. Dynamic control of this radiation could enable the design of novel infrared sources; however, the spectral characteristics of the radiated power are dictated by the electromagnetic energy density and emissivity, which are ordinarily fixed properties of the material and temperature. Here we experimentally demonstrate tunable electronic control of blackbody emis...

  6. 关于换热器的低温黑体辐射源%A low-temperature blackbody cavity with a heat exchanger

    Institute of Scientific and Technical Information of China (English)

    蓝卉; 薛生虎

    2012-01-01

    A new type of design for blackbody cavity was presented. The apparatus adopts a fluid bath to achieve temperature uniformity along with the cavity and uses cooled nitrogen gas to prevent frost condensation on the wall and the window of the blackbody cavity when the designed blackbody cavity works at temperatures below the dew point. The shape of the blackbody cavity was cone-cylinder. The cone angle of the cavity was 120°. The diameter of the cavity was 50 mm. The length of the cavity was 300 mm. The temperature stability of blackbody cavity was better than ± 0. 05℃/ 30 min. The calculated emissivity of the designed blackbody cavity was 0. 998. The measured emissivity of the designed blackbody cavity was 0. 997. The measured emissivity agrees well with the calculated one.%介绍一种工作在-80℃~+100℃的基于换热器的新型低温标准黑体辐射源的设计和其发射率的计算.这种黑体辐射源采用液体恒温槽均温致冷和采用气帘隔离法消除低温凝露和结霜,黑体空腔形状为圆锥-圆柱型,锥角为120°,空腔内径50 mm,腔长为300 mm,控温稳定性优于±0.05℃/30 min.理论计算的黑体空腔有效发射率为0.998(保留小数点后三位),比对实验测量得到的有效发射率为0.997(保留小数点后三位),二者接近一致.

  7. Spectrum of the cosmic background radiation: early and recent measurements from the White Mountain Research Station

    International Nuclear Information System (INIS)

    The White Mountain Research Station has provided a support facility at a high, dry, radio-quiet site for measurements that have established the blackbody character of the cosmic microwave background radiation. This finding has confirmed the interpretation of the radiation as a relic of the primeval fireball and helped to establish the hot Big Bang theory as the standard cosmological model

  8. Rydberg atom detection of the temporal coherence of cosmic microwave background radiation

    CERN Document Server

    Tscherbul, Timur V

    2013-01-01

    Rydberg atoms immersed in cold blackbody radiation are shown to display long-lived quantum coherence effects on timescales of tens of picoseconds. By solving non-Markovian equations of motion with no free parameters we obtain the time evolution of the density matrix, and demonstrate that the blackbody-induced temporal coherences manifest as quantum beats in time-resolved fluorescence intensities of the Rydberg atoms. A measurable fluorescence signal can be obtained with a cold trapped ensemble of 1e8 Rydberg atoms subject to 2.7 K cosmic microwave background radiation (CMB), allowing for novel insights into previously unexamined quantum coherence properties of CMB.

  9. Trapping of pellet cloud radiation in thermonuclear plasmas

    International Nuclear Information System (INIS)

    The experimental and theoretical data on radiation trapping in clouds of pellets injected into thermonuclear plasmas are presented. The theoretical modeling is performed in terms of equivalent Stark spectral line widths under condition of LTE (Sakha-Boltzman) in pellet cloud plasmas. It is shown that a domain of blackbody radiation could exist in hydrogen pellet clouds resulting in ''pellet disappearance'' effect which is absent in a case of impurity pellet clouds. Reasons for this difference are discussed. (author)

  10. Planck's radiation law: is a quantum-classical perspective possible?

    Science.gov (United States)

    Marrocco, Michele

    2016-05-01

    Planck's radiation law provides the solution to the blackbody problem that marks the decline of classical physics and the rise of the quantum theory of the radiation field. Here, we venture to suggest the possibility that classical physics might be equally suitable to deal with the blackbody problem. A classical version of the Planck's radiation law seems to be achievable if we learn from the quantum-classical correspondence between classical Mie theory and quantum-mechanical wave scattering from spherical scatterers (partial wave analysis). This correspondence designs a procedure for countable energy levels of the radiation trapped within the blackbody treated within the multipole approach of classical electrodynamics (in place of the customary and problematic expansion in terms of plane waves that give rise to the ultraviolet catastrophe). In turn, introducing the Boltzmann discretization of energy levels, the tools of classical thermodynamics and statistical theory become available for the task. On the other hand, the final result depends on a free parameter whose physical units are those of an action. Tuning this parameter on the value given by the Planck constant makes the classical result agree with the canonical Planck's radiation law.

  11. Entropy/information flux in Hawking radiation

    OpenAIRE

    Alonso-Serrano, Ana; Visser, Matt(School of Mathematics, Statistics, and Operations Research, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand)

    2015-01-01

    Blackbody radiation contains (on average) an entropy of $3.9\\pm2.5$ bits per photon. This applies not only to the proverbial case of "burning a lump of coal", but also to the Hawking radiation from both analogue black holes and general relativistic black holes. The flip side of this observation is the information budget: If the emission process is unitary, (as it certainly is for normal physical/chemical burning, and also for the Hawking emission from analogue black holes), then this entropy ...

  12. Hawking radiation from the dilaton-(anti) de Sitter black hole via covariant anomaly

    Institute of Scientific and Technical Information of China (English)

    Han Yi-Wen; Bao Zhi-Qing; Hong Yun

    2009-01-01

    Adopting the anomaly cancellation method, initiated by Robinson and Wilczek recently, this paper discusses Hawking radiation from the dilaton-(anti) de Sitter black hole. To save the underlying gauge and general covariance, it introduces covariant fluxes of gauge and energy-momentum tensor to cancel the gauge and gravitational anomalies. The result shows that the introduced compensating fluxes are equivalent to those of a 2-dimensional blackbody radiation at Hawking temperature with appropriate chemical potential.

  13. Enhancing radiative energy transfer through thermal extraction

    Science.gov (United States)

    Tan, Yixuan; Liu, Baoan; Shen, Sheng; Yu, Zongfu

    2016-06-01

    Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a). In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics. Thermal extraction works by using a specially designed thermal extractor to convert and guide the near-field energy to the far field, as shown in Fig. 1b. The same blackbody as shown in Fig. 1a is placed closely below the thermal extractor with a spacing smaller than the thermal wavelength. The near-field coupling transfers radiative energy with a density greater than σT4. The thermal extractor, made from transparent and high-index or structured materials, does not emit or absorb any radiation. It transforms the near-field energy and sends it toward the far field. As a result, the total amount of far-field radiative heat dissipated by the same blackbody is greatly enhanced above SσT4, where S is the area of the emitter. This paper will review the progress in thermal

  14. Nonlocal Effects in Black Body Radiation

    CERN Document Server

    Bremm, G N

    2016-01-01

    Nonlocal electrodynamics is a formalism developed to include nonlocal effects in the measurement process caused by the non-inertial state of the observers. This theory modifies Maxwell's electrodynamics by eliminating the hypothesis of locality that assumes an accelerated observer simultaneously equivalent to a comoving inertial frame of reference. In this scenario, the transformation between an inertial and accelerated observer is generalized which affects the properties of physical fields. In particular, we analyze how an uniformly accelerated observer perceives a homogeneous and isotropic blackbody radiation. We show that all nonlocal effects are transient and most relevant in the first period of acceleration.

  15. Measurement and evaluation of the radiative properties of a thin solid fuel

    Science.gov (United States)

    Pettegrew, Richard; Street, Kenneth; Pitch, Nancy; Tien, James; Morrison, Phillip

    2003-01-01

    Accurate modeling of combustion systems requires knowledge of the radiative properties of the system. Gas phase properties are well known, but detailed knowledge of surface properties is limited. Recent work has provided spectrally resolved data for some solid fuels, but only for the unburned material at room temperature, and for limited sets of previously burned and quenched samples. Due to lack of knowledge of the spectrally resolved properties at elevated temperatures, as well as processing limitations in the modeling effort, graybody values are typically used for the fuels surface radiative properties. However, the spectrally resolved properties for the fuels at room temperature can be used to give a first-order correction for temperature effects on the graybody values. Figure 1 shows a sample of the spectrally resolved emittance/absorptance for a thin solid fuel of the type commonly used in combustion studies, from approximately 2 to 20 microns. This plot clearly shows a strong spectral dependence across the entire range. By definition, the emittance is the ratio of the emitted energy to that of a blackbody at the same temperature. Therefore, to determine a graybody emittance for this material, the spectrally resolved data must be applied to a blackbody curve. The total area under the resulting curve is ratioed to the total area under the blackbody curve to yield the answer. Due to the asymmetry of the spectrally resolved emittance and the changing shape of the blackbody curve as the temperature increases, the relative importance of the emittance value at any given wavelength will change as a function of temperature. Therefore, the graybody emittance value for a given material will change as a function of temperature even if the spectral dependence of the radiative properties remains unchanged. This is demonstrated in Figures 2 and 3, which are plots of the spectrally resolved emittance for KimWipes (shown in Figure 1) multiplied by the blackbody curves for

  16. Determination of the time evolution of the electron-temperature profile of reactor-like plasmas from the measurement of blackbody electron-cyclotron emission

    International Nuclear Information System (INIS)

    Plasma characteristics (i.e., n/sub e/ greater than or equal to 1 x 1013 cm-3, T/sub e/ greater than or equal to 1070K, B/sub psi/ greater than or equal to 20 kG) in present and future magnetically confined plasma devices, e.g., Princeton Large Torus (PLT) and Tokamak Fusion Test Reactor (TFTR), meet the conditions for blackbody emission near the electron cyclotron frequency and at few harmonics. These conditions, derived from the hot plasma dielectric tensor, have been verified by propagation experiments on PLT and the Princeton Model-C Stellarator. Blackbody emission near the fundamental electron cyclotron frequency and the second harmonic have been observed in PLT and is routinely measured to ascertain the time evolution of the electron temperature profile. These measurements are especially valuable in the study of auxiliary heating of tokamak plasma. Measurement and calibration techniques will also be discussed with special emphasis on our fast-scanning heterodyne receiver concept

  17. Radiative characteristics of the Chelyabinsk superbolide

    Science.gov (United States)

    Yanagisawa, Masahisa

    2015-12-01

    On Feb. 15, 2013, a meteoroid with a size of about 19 m plunged into the terrestrial atmosphere at 19 km s-1 and burst at an altitude of about 30 km over the city of Chelyabinsk, Russia. Here we present light curves for the bolide in the red, green, and blue color bands, derived from an analysis of a video that was recorded by a dashboard camera and released on the Internet. Our results demonstrate that the bolide was blue-green in color, which is inconsistent with the Planck spectrum before the meteoroid began to fragment. Fragmentation triggered a flare-up of the bolide and 90% of its radiation energy at optical wavelengths was released within a period of about 2 s after that. During the same period, the brightness ratios among the three bands became consistent with 4000 K blackbody radiation. Based on the peak luminosity, a surface area of several square kilometers would be required for a 4000 K blackbody. It is considered that the radiation source of the bolide was an elongated cloud of vapor and debris produced through severe fragmentation of the meteoroid.

  18. Modulation and amplification of radiative far field heat transfer: Towards a simple radiative thermal transistor

    Energy Technology Data Exchange (ETDEWEB)

    Joulain, Karl; Ezzahri, Younès; Drevillon, Jérémie [Institut Pprime, Université de Poitiers-CNRS-ENSMA, UPR 3346, ENSIP Bâtiment B25, 2 Rue Pierre Brousse, TSA 41105, 86073 Poitiers Cedex 9 (France); Ben-Abdallah, Philippe [Laboratoire Charles Fabry, UMR 8501, Institut d' optique, CNRS, Université Paris-Sud 11, 2 Avenue Augustin Fresnel, 91127 Palaiseau (France)

    2015-03-30

    We show in this article that phase change materials (PCM) exhibiting a phase transition between a dielectric state and a metallic state are good candidates to perform modulation as well as amplification of radiative thermal flux. We propose a simple situation in plane parallel geometry where a so-called radiative thermal transistor could be achieved. In this configuration, we put a PCM between two blackbodies at different temperatures. We show that the transistor effect can be achieved easily when this material has its critical temperature between the two blackbody temperatures. We also see that the more the material is reflective in the metallic state, the more switching effect is realized, whereas the more PCM transition is stiff in temperature, the more thermal amplification is high. We finally take the example of VO{sub 2} that exhibits an insulator-metallic transition at 68 °C. We show that a demonstrator of a radiative transistor could easily be achieved in view of the heat flux levels predicted. Far-field thermal radiation experiments are proposed to back the results presented.

  19. SSPM在蓝宝石光纤黑体腔瞬态高温传感器中的应用%Application of the SSPM in Sapphire Fiber Black-Body Cavity Transient High Temperature Sensor

    Institute of Scientific and Technical Information of China (English)

    潘保武; 郝晓剑; 李伟; 周汉昌

    2011-01-01

    介绍了一种基于黑体全辐射原理的蓝宝石光纤黑体腔高温传感器,从黑体腔制作和微光信号探测方面进行了分析,测试了固态光电倍增管(Solid-State Photomultiplier,SSPM)的输入输出特性,并给出了实验结果.实验结果表明:由于采用新型光电探测器和膜层材料,大大提高了传感器的测温范围和信噪比.该高温传感器的测试范围上限大于2000 C,响应时间小于100 ms,能够满足科研和工业生产中特殊环境下的温度测量.%Sapphire fiber blackbody cavity transient high temperature sensor based on a whole blank-body radiation theory was introduced, and blank-body cavity production and weak photoelectric signal detection was analyzed. Testing results of input and output characteristics for the solid-state photomultiplier(SSPM) were also given. The experimental results show that the temperature range and signal to noise ratio of the sensor are increased using new photoelectric detector and film material. The temperature sensor measuring range upper limit is greater than 2 000 C and the response time less than 100 ms. It can meet the research and industrial production with some specific environment for temperature measurement.

  20. Radiation Feedback in ULIRGS: Are Photons Movers and Shakers?

    CERN Document Server

    Davis, Shane W; Stone, James M; Murray, Norman

    2014-01-01

    We use our variable Eddington tensor (VET) radiation hydrodynamics code to perform two-dimensional simulations to study the impact of radiation forces on atmospheres composed of dust and gas. Our setup closely follows that of Krumholz & Thompson, assuming that dust and gas are well-coupled and that the radiation field is characterized by blackbodies with temperatures >~ 80 K, as might be found in ultraluminous infrared galaxies. In agreement with previous work, we find that Rayleigh-Taylor instabilities develop in radiation supported atmospheres, leading to inhomogeneities that limit momentum exchange between radiation and dusty gas, and eventually providing a near balance of the radiation and gravitational forces. However, the evolution of the velocity and spatial distributions of the gas differs significantly from previous work, which utilized a less accurate flux-limited diffusion (FLD) method. Our VET simulations show continuous net acceleration of the gas, with no steady-state reached by the end of t...

  1. Distortion of the Microwave Blackbody Background Radiation Implied by the Baryon-symmetric Cosmology of Omnes and the Galaxy Formation Theory of Stecker and Puget

    Science.gov (United States)

    Stecker, F. W.; Puget, J. L.

    1973-01-01

    Theories on the evolution of the universe are evaluated. Particular attention was given to Omnes and Stecker and Puget theories. Data cover distortion of the microwave black body background energy distribution at red shifts between 10,000 and 1.000, and black body distortion due to antimatter and annihilation reactions.

  2. Coherent dynamics of Rydberg atoms in cosmic-microwave-background radiation

    Science.gov (United States)

    Tscherbul, Timur V.; Brumer, Paul

    2014-01-01

    Rydberg atoms excited by cold blackbody radiation are shown to display long-lived quantum coherences on time scales of tens of picoseconds. By solving non-Markovian equations of motion with no free parameters we obtain the time evolution of the density matrix and demonstrate that the blackbody-induced temporal coherences manifest as slowly decaying (100 ps) quantum beats in time-resolved fluorescence. An analytic model shows the dependence of the coherent dynamics on the energy splitting between atomic eigenstates, transition dipole moments, and coherence time of the radiation. Experimental detection of the fluorescence signal from a trapped ensemble of 108 Rydberg atoms is discussed, but shown to be technically challenging at present, requiring cosmic-microwave-background amplification somewhat beyond current practice.

  3. Hawking radiation temperatures in non-stationary Kerr black holes with different tortoise coordinate transformations

    Science.gov (United States)

    Lan, X. G.; Jiang, Q. Q.; Wei, L. F.

    2012-04-01

    We apply the Damour-Ruffini-Sannan method to study the Hawking radiations of scalar and Dirac particles in non-stationary Kerr black holes under different tortoise coordinate transformations. We found that all the relevant Hawking radiation spectra show still the blackbody ones, while the Hawking temperatures are strongly related to the used tortoise coordinate transformations. The properties of these dependences are discussed analytically and numerically. Our results imply that proper selections of tortoise coordinate transformations should be important in the studies of Hawking radiations and the correct selection would be given by the experimental observations in the future.

  4. INSTRUMENTATION FOR MEASURING AND TRANSMISSION THE SOLAR RADIATION THROUGH EARTH’S ATMOSPHERE

    OpenAIRE

    Alexandru Dan Toma

    2013-01-01

    The Sun's energy is distributed over a broad range of the electromagnetic spectrum and Sun behaves approximately like a "blackbody" radiating at a temperature of about 5800 K with maximum output in the green-yellow part of the visible spectrum, around 500 nm. Not all solar radiation reaching the top of the atmosphere reaches Earth's surface due to a various optical phenomena in regard to solar radiation crossing the Earth’s atmosphere. In order to investigate them, there are two general categ...

  5. Radiative contribution to thermal conductance in animal furs and other woolly insulators.

    Science.gov (United States)

    Simonis, Priscilla; Rattal, Mourad; Oualim, El Mostafa; Mouhse, Azeddine; Vigneron, Jean-Pol

    2014-01-27

    This paper deals with radiation's contribution to thermal insulation. The mechanism by which a stack of absorbers limits radiative heat transfer is examined in detail both for black-body shields and grey-body shields. It shows that radiation energy transfer rates should be much faster than conduction rates. It demonstrates that, for opaque screens, increased reflectivity will dramatically reduce the rate of heat transfer, improving thermal insulation. This simple model is thought to contribute to the understanding of how animal furs, human clothes, rockwool insulators, thermo-protective containers, and many other passive energy-saving devices operate.

  6. Design and calibration of a novel transient radiative heat flux meter for a spacecraft thermal test.

    Science.gov (United States)

    Sheng, Chunchen; Hu, Peng; Cheng, Xiaofang

    2016-06-01

    Radiative heat flux measurement is significantly important for a spacecraft thermal test. To satisfy the requirements of both high accuracy and fast response, a novel transient radiative heat flux meter was developed. Its thermal receiver consists of a central thermal receiver and two thermal guarded annular plates, which ensure the temperature distribution of the central thermal receiver to be uniform enough for reasonably applying lumped heat capacity method in a transient radiative heat flux measurement. This novel transient radiative heat flux meter design can also take accurate measurements regardless of spacecraft surface temperature and incident radiation spectrum. The measurement principle was elaborated and the coefficients were calibrated. Experimental results from testing a blackbody furnace and an Xenon lamp show that this novel transient radiative heat flux meter can be used to measure transient radiative heat flux up to 1400 W/m(2) with high accuracy and the response time of less than 10 s. PMID:27370482

  7. Hawking radiation from gravity's rainbow via gravitational anomaly

    Institute of Scientific and Technical Information of China (English)

    Zeng Xiao-Xiong; Yang Shu-Zheng; Chen De-You

    2008-01-01

    Based on the anomaly cancellation method,initiated by Robinson and Wilczek,we investigates Hawking radiation from the modified Schwarzschild black hole from gravity's rainbow from the anomaly point of view.Unlike the general Schwarzschild space-time,the metric of this black hole depends on the energies of probes.The obtained result shows to restore the underlying general covariance at the quantum level in the effective field,the covariant compensating flux of energy-momentum tensor,which is related to the energies of the probes,should precisely equal to that of a (1+1)-dimensional blackbody at the Hawking temperature.

  8. Thornhill, de Broglie and the kinetic theory of electromagnetic radiation

    CERN Document Server

    Dunning-Davies, J P

    2008-01-01

    In 1983, Thornhill showed that Planck's energy distribution for a black-body radiation field could be derived for a gas-like aether with Maxwellian statistics. Further, it was shown that the frequency of electromagnetic waves correlates with the energy per unit mass of the particles, not with their energy, thus differing from Planck's quantum hypothesis. He pointed out that de Broglie, in a paper of 1922, was on the way to achieving this result but did not pursue the matter to its logical conclusion. Here a translation of de Broglie's paper is presented to draw attention to this point. Some brief additional comments are included also.

  9. Insights from Synthetic Star-forming Regions: II. Verifying Dust Surface Density, Dust Temperature & Gas Mass Measurements with Modified Blackbody Fitting

    CERN Document Server

    Koepferl, Christine M; Dale, James E

    2016-01-01

    We use a large data-set of realistic synthetic observations (PaperI) to assess how observational techniques affect the measurement of physical properties of star-forming regions. In this paper (PaperII), we explore the reliability of the measured total gas mass, dust surface density and dust temperature maps derived from modified blackbody fitting of synthetic Herschel observations. We found from our pixel-by-pixel analysis of the measured dust surface density and dust temperature a worrisome error spread especially close to star-formation sites and low-density regions, where for those "contaminated" pixels the surface densities can be under/overestimated by up to three orders of magnitude. In light of this, we recommend to treat the pixel-based results from this technique with caution in regions with active star formation. In regions of high background typical in the inner Galactic plane, we are not able to recover reliable surface density maps of individual synthetic regions, since low-mass regions are lost...

  10. The diffuse galactic gamma radiation: The Compton contribution and component separation by energy interval and galactic coordinates

    Science.gov (United States)

    Kniffen, D. A.; Fichtel, C.

    1981-01-01

    The radiation to be expected from cosmic ray interactions with matter and photons was examined. Particular emphasis is placed on the Compton emission. Both the photon density in and near the visible region and that in the region are deduced from the estimates of the emission functions throughout the Galaxy. The blackbody radiation is also included in the estimate of the total Compton emission. The result suggests that the gamma ray Compton radiation from cosmic ray ineractions with galactic visible and infrared photons is substantially larger than previously believed.

  11. Hawking radiation from the charged and magnetized BTZ black hole via covariant anomaly

    Institute of Scientific and Technical Information of China (English)

    Zeng Xiao-Xiong; Yang Shu-Zheng

    2009-01-01

    This paper discusses Hawking radiation from the charged and magnetized Bafiados-Teitelboim-Zanelli (BTZ) black hole from the viewpoint of anomaly, initiated by Robinson and Wilczek recently. It reconstructs the electromagnetic field tensor and the Lagrangian of the field corresponding to the source with electric and magnetic charges to redefine an equivalent charge and gauge potential. It employs the covariant anomaly cancellation method to determine thecompensating fluxes of charge flow and energy-momentum tensor, which are shown to match with those of the 2- dimensional blackbody radiation at the Hawking temperature exactly.

  12. Reflection of infrared radiation from thin aluminium layers

    CERN Document Server

    Calatroni, Sergio

    2001-01-01

    The thermal shielding of the LHC magnets cryostats will make use of Multi-Layer Insulation. This is a sandwich of several Mylar (polyester) foils 6 µm thick coated with a thin film of aluminium, having a thickness of some 30 nm. The thickness of the aluminium film must be kept at a minimum to minimise lateral thermal conduction. The outer layer of this sandwich stays at a temperature of 20 K or below, and receives IR radiation from surfaces at 77 K (wavelength of 37.6 µm at the peak of blackbody radiation), which should be reflected with the highest efficiency. The minimum thickness for the aluminium layer to avoid transmission of the radiation can be calculated by making use of the skin effect theory, taking into account the changes in electrical properties that are due to the extremely low thickness of the film.

  13. The definition analyses of radiation temperature measurement area

    Institute of Scientific and Technical Information of China (English)

    Fu Tairan; Cheng Xiaofang; Zhong Maohua

    2008-01-01

    In the research of primary spectrum pyrometry, this paper discussed the definition problem of radiation tem-perature measurement area based on the measurement coordinates. For the linear spectrum emissivity model and im-proved monotonic spectrum emissivity model, the characteristics of radiation temperature measurement area restricted by the measurement coordinates were theoretically analyzed, through the investigations of the temperature and emissivity co-ordinate axes. Choosing the specific primary spectrum pyrometer as an example in applications, the theoretical area of radiation temperature measurement of this pyrometer was given and it was verified through blackbody experiments. The discussions of this paper will provide the necessary foundation for the theory research development of primary spectrum pyrometry and the realization of technical applications.

  14. Tunneling Radiation of Massive Vector Bosons from Dilaton Black Holes

    Science.gov (United States)

    Li, Ran; Zhao, Jun-Kun; Wu, Xing-Hua

    2016-07-01

    It is well known that Hawking radiation can be treated as a quantum tunneling process of particles from the event horizon of black hole. In this paper, we attempt to apply the massive vector bosons tunneling method to study the Hawking radiation from the non-rotating and rotating dilaton black holes. Starting with the Proca field equation that govern the dynamics of massive vector bosons, we derive the tunneling probabilities and radiation spectrums of the emitted vector bosons from the static spherical symmetric dilatonic black hole, the rotating Kaluza—Klein black hole, and the rotating Kerr—Sen black hole. Comparing the results with the blackbody spectrum, we satisfactorily reproduce the Hawking temperatures of these dilaton black holes, which are consistent with the previous results in the literature. Supported by National Natural Science Foundation of China under Grant No. 11205048

  15. Radiation enteritis

    Science.gov (United States)

    ... enteropathy; Radiation-induced small bowel injury; Post-radiation enteritis ... often are no good treatments for chronic radiation enteritis that is more severe. Medicines such as cholestyramine, ...

  16. Tests of Exoplanet Atmospheric Radiative Transfer Codes

    Science.gov (United States)

    Harrington, Joseph; Challener, Ryan; DeLarme, Emerson; Cubillos, Patricio; Blecic, Jasmina; Foster, Austin; Garland, Justin

    2016-10-01

    Atmospheric radiative transfer codes are used both to predict planetary spectra and in retrieval algorithms to interpret data. Observational plans, theoretical models, and scientific results thus depend on the correctness of these calculations. Yet, the calculations are complex and the codes implementing them are often written without modern software-verification techniques. In the process of writing our own code, we became aware of several others with artifacts of unknown origin and even outright errors in their spectra. We present a series of tests to verify atmospheric radiative-transfer codes. These include: simple, single-line line lists that, when combined with delta-function abundance profiles, should produce a broadened line that can be verified easily; isothermal atmospheres that should produce analytically-verifiable blackbody spectra at the input temperatures; and model atmospheres with a range of complexities that can be compared to the output of other codes. We apply the tests to our own code, Bayesian Atmospheric Radiative Transfer (BART) and to several other codes. The test suite is open-source software. We propose this test suite as a standard for verifying current and future radiative transfer codes, analogous to the Held-Suarez test for general circulation models. This work was supported by NASA Planetary Atmospheres grant NX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G.

  17. Hawking Radiation and Entropy of a Dynamic Dilaton-Maxwell Black Hole with a New Tortoise Coordinate Transformation

    Science.gov (United States)

    Lan, Xiao-Gang

    2013-05-01

    By introducing a new tortoise coordinate transformation, we apply Damour-Ruffini-Sannan method to study the Hawking radiation of massive scalar particles in a dynamic Dilaton-Maxwell black hole. We find that Hawking radiation spectrum shows still the blackbody one, while the Hawking temperature is significantly changed. Additionally, by adopting the thin film method, we calculate the entropy of a dynamic Dilaton-Maxwell black hole. The result indicates that the entropy for such a black hole is still in proportional to the area of its event horizon.

  18. A theoretical analysis of the influence of turbulence on radiative emission in turbulent diffusion flames of methane

    Science.gov (United States)

    Coelho, P. J.

    2012-06-01

    A theoretical analysis is reported to quantify the increase of radiative emission due to turbulence for methane diffusion flames burning in air. The instantaneous thermochemical state of the reactive mixture is described by a flamelet model and a detailed chemical mechanism. Mean values of the absorption coefficient, blackbody radiation intensity and radiative emission are evaluated for different turbulence levels by assuming the pdf shape of mixture fraction. The results show that turbulent fluctuations generally contribute to reduce the Planck mean absorption coefficient of the medium, in contrast with the blackbody radiation intensity, which is significantly increased by turbulence. If the turbulence level is relatively small, the influence of turbulence on the absorption coefficient is marginal. Otherwise, fluctuations of the absorption coefficient of the medium should be taken into account. The mean radiative emission is underestimated if turbulent fluctuations are fully ignored and overestimated if only temperature fluctuations are considered, while neglecting fluctuations of the absorption coefficient of the medium, the error being generally higher in the latter case. The effects of turbulence on radiative emission are stronger in the fuel-lean region and close to stoichiometric conditions than in the fuel-rich region.

  19. Radiation thermodynamics with applications to lasing and fluorescent cooling

    Science.gov (United States)

    Mungan, Carl E.

    2005-04-01

    Laser cooling of bulk matter uses thermally assisted fluorescence to convert heat into light and can be interpreted as an optically pumped laser running in reverse. Optical pumping in such devices drives the level populations out of equilibrium. Nonthermal radiative energy transfers are thereby central to the operation of both lasers and luminescent coolers. A thermodynamic treatment of their limiting efficiencies requires a careful development of the entropy and effective temperatures of radiation, valid for the entire range of light from the blackbody to the ideal laser limiting cases. In particular, the distinct meaning and utility of the brightness and flux temperatures should be borne in mind. Numerical examples help illustrate these concepts at a level suitable for undergraduate physics majors.

  20. A comparison of different entransy flow definitions and entropy generation in thermal radiation optimization

    International Nuclear Information System (INIS)

    In thermal radiation, taking heat flow as an extensive quantity and defining the potential as temperature T or the blackbody emissive power U will lead to two different definitions of radiation entransy flow and the corresponding principles for thermal radiation optimization. The two definitions of radiation entransy flow and the corresponding optimization principles are compared in this paper. When the total heat flow is given, the optimization objectives of the extremum entransy dissipation principles (EEDPs) developed based on potentials T and U correspond to the minimum equivalent temperature difference and the minimum equivalent blackbody emissive power difference respectively. The physical meaning of the definition based on potential U is clearer than that based on potential T, but the latter one can be used for the coupled heat transfer optimization problem while the former one cannot. The extremum entropy generation principle (EEGP) for thermal radiation is also derived, which includes the minimum entropy generation principle for thermal radiation. When the radiation heat flow is prescribed, the EEGP reveals that the minimum entropy generation leads to the minimum equivalent thermodynamic potential difference, which is not the expected objective in heat transfer. Therefore, the minimum entropy generation is not always appropriate for thermal radiation optimization. Finally, three thermal radiation optimization examples are discussed, and the results show that the difference in optimization objective between the EEDPs and the EEGP leads to the difference between the optimization results. The EEDP based on potential T is more useful in practical application since its optimization objective is usually consistent with the expected one. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  1. A comparison of different entransy flow definitions and entropy generation in thermal radiation optimization

    Institute of Scientific and Technical Information of China (English)

    Zhou Bing; Cheng Xue-Tao; Liang Xin-Gang

    2013-01-01

    In thermal radiation,taking heat flow as an extensive quantity and defining the potential as temperature T or the blackbody emissive power U will lead to two different definitions of radiation entransy flow and the corresponding principles for thermal radiation optimization.The two definitions of radiation entransy flow and the corresponding optimization principles are compared in this paper.When the total heat flow is given,the optimization objectives of the extremum entransy dissipation principles (EEDPs) developed based on potentials T and U correspond to the minimum equivalent temperature difference and the minimum equivalent blackbody emissive power difference respectively.The physical meaning of the definition based on potential U is clearer than that based on potential T,but the latter one can be used for the coupled heat transfer optimization problem while the former one cannot.The extremum entropy generation principle (EEGP) for thermal radiation is also derived,which includes the minimum entropy generation principle for thermal radiation.When the radiation heat flow is prescribed,the EEGP reveals that the minimum entropy generation leads to the minimum equivalent thermodynamic potential difference,which is not the expected objective in heat transfer.Therefore,the minimum entropy generation is not always appropriate for thermal radiation optimization.Finally,three thermal radiation optimization examples are discussed,and the results show that the difference in optimization objective between the EEDPs and the EEGP leads to the difference between the optimization results.The EEDP based on potential T is more useful in practical application since its optimization objective is usually consistent with the expected one.

  2. Entropy/information flux in Hawking radiation

    CERN Document Server

    Alonso-Serrano, Ana

    2015-01-01

    Blackbody radiation contains (on average) an entropy of $3.9\\pm2.5$ bits per photon. This applies not only to the proverbial case of "burning a lump of coal", but also to the Hawking radiation from both analogue black holes and general relativistic black holes. The flip side of this observation is the information budget: If the emission process is unitary, (as it certainly is for normal physical/chemical burning, and also for the Hawking emission from analogue black holes), then this entropy is exactly compensated by the "hidden information" in the correlations. We shall now extend this argument to the Hawking radiation from general relativistic black holes, (where previous discussion is both heated and inconclusive), demonstrating that the assumption of unitarity leads to a perfectly reasonable entropy/information budget without any hint of a "firewall". The assumption of unitarity instead has a different implication --- the horizon (if present) cannot be an *event* horizon, it must be an *apparent/trapping*...

  3. Recent progress in thermodynamics of radiation——exergy of radiation, effective temperature of photon and entropy constant of photon

    Institute of Scientific and Technical Information of China (English)

    CHEN ZeShao; MO SongPing; HU Peng

    2008-01-01

    The recent progress on thermodynamic properties of spectral radiant energy in the field of thermodynamics of radiation is reviewed. The effective temperature of photon Tλ representing the energy quality of photon is introduced. The relation tropy constant of photon is given as sλ=3.72680×10-23 J/K. The exergy, entropy and enthalpy of the spectral blackbody radiation, the equilibrium cavity radiation, the radiation flux in open system are discussed by using Tλ and sλ, as well as the en-tropy change in the process of the state transformation of photon gas. By analyzing the exergy of spectral radiation, the exergy efficiency of spectral radiant energy available for photosynthesis is proved to be higher than that of light energy. The method for the irreversible loss of exergy calculation in radiant energy converters is also discussed.

  4. Cosmic microwave background radiation: anisotropies and polarization

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Sergio Vitorino de Borba; Guaitolini Junior, J.T. [Universidade Federal do Espirito Santo (UFES), ES (Brazil). Dept. de Fisica

    2011-07-01

    Full text: The development of cosmological models which describe correctly the universe we live in is becoming more reliable, as the improvement of the measure tools provides us with more accurate information. The Cosmic Microwave Background Radiation (CMB) was discovered accidentally by Arno Penzias and Robert Wilson in early 60s, becoming a strong evidence in favor of the Big Bang model. This radiation, typical of a blackbody with maximum intensity in the microwave band, was already predicted by Gamov, Alpher and Herman and it's originated from the uncoupling between radiation and matter in recombination, at z = 1088. Nowadays, since no other observable in Cosmology provides us with information of such a distant past, studying CMB is of great importance for the process of the comprehension of the universe. The detection of small anisotropies at the temperatures distribution, which remain even after considering the universe recent phenomena and effects of referential movements, evidenced that the primordial universe was closer to the thermodynamic equilibrium and that the appearance of small inhomogeneities were the beginning of the formation of the structures we see today. These small anisotropies are important because from them it is possible to observe polarization at CMB. In a universe so perfectly homogeneous and isotropic, polarization would never exist. In this work, we calculate the behavior of light propagation in a disturbed universe, obtaining anisotropies from the potential variation at the radiation way and from the peculiar velocity of matter which spread radiation in our direction. At this point, the next purpose is to theoretically calculate these anisotropies in an alternative cosmological example, such as in Brans-Dicke theory or a model of an universe filled with a viscous fluid. Besides, with the Stokes Parameters describing the radiation field, we study the CMB polarization, in particular analyzing the polarization tensor in a 2-sphere as

  5. Radiation protection

    International Nuclear Information System (INIS)

    This work define procedures and controls about ionizing radiations. Between some definitions it found the following topics: radiation dose, risk, biological effects, international radioprotection bodies, workers exposure, accidental exposure, emergencies and radiation protection

  6. Radiation dosimetry

    CERN Document Server

    Hine, Gerald J; Hine, Gerald J

    1956-01-01

    Radiation Dosimetry focuses on the advancements, processes, technologies, techniques, and principles involved in radiation dosimetry, including counters and calibration and standardization techniques. The selection first offers information on radiation units and the theory of ionization dosimetry and interaction of radiation with matter. Topics include quantities derivable from roentgens, determination of dose in roentgens, ionization dosimetry of high-energy photons and corpuscular radiations, and heavy charged particles. The text then examines the biological and medical effects of radiation,

  7. Radiation and Heat Transfer in the Atmosphere: A Comprehensive Approach on a Molecular Basis

    Directory of Open Access Journals (Sweden)

    Hermann Harde

    2013-01-01

    Full Text Available We investigate the interaction of infrared active molecules in the atmosphere with their own thermal background radiation as well as with radiation from an external blackbody radiator. We show that the background radiation can be well understood only in terms of the spontaneous emission of the molecules. The radiation and heat transfer processes in the atmosphere are described by rate equations which are solved numerically for typical conditions as found in the troposphere and stratosphere, showing the conversion of heat to radiation and vice versa. Consideration of the interaction processes on a molecular scale allows to develop a comprehensive theoretical concept for the description of the radiation transfer in the atmosphere. A generalized form of the radiation transfer equation is presented, which covers both limiting cases of thin and dense atmospheres and allows a continuous transition from low to high densities, controlled by a density dependent parameter. Simulations of the up- and down-welling radiation and its interaction with the most prominent greenhouse gases water vapour, carbon dioxide, methane, and ozone in the atmosphere are presented. The radiative forcing at doubled CO2 concentration is found to be 30% smaller than the IPCC-value.

  8. Energy shift due to anisotropic black body radiation

    CERN Document Server

    Flambaum, Victor V; Safronova, Marianna S

    2015-01-01

    In many applications a source of the black-body radiation (BBR) can be highly anisotropic. This leads to the BBR shift that depends on tensor polarizability and on the projection of the total angular momentum of ions and atoms in a trap. We derived formula for the anisotropic BBR shift and performed numerical calculations of this effect for Ca$^+$ and Yb$^+$ transitions of experimental interest. These ions used for a design of high-precision atomic clocks, fundamental physics tests such as search for the Lorentz invariance violation and space-time variation of the fundamental constants, and quantum information. Anisotropic BBR shift may be one of the major systematic effect in these experiments.

  9. Space Radiation

    Science.gov (United States)

    Wu, Honglu

    2006-01-01

    Astronauts receive the highest occupational radiation exposure. Effective protections are needed to ensure the safety of astronauts on long duration space missions. Increased cancer morbidity or mortality risk in astronauts may be caused by occupational radiation exposure. Acute and late radiation damage to the central nervous system (CNS) may lead to changes in motor function and behavior, or neurological disorders. Radiation exposure may result in degenerative tissue diseases (non-cancer or non-CNS) such as cardiac, circulatory, or digestive diseases, as well as cataracts. Acute radiation syndromes may occur due to occupational radiation exposure.

  10. Radiation Therapy

    Science.gov (United States)

    ... goal of causing less harm to the surrounding healthy tissue. You don't have to worry that you'll glow in the dark after radiation treatment: People who receive external radiation are not radioactive. You' ...

  11. Ionizing radiations

    International Nuclear Information System (INIS)

    The purpose of this article is to simplify some of the relevant points of legislation, biological effects and protection for the benefit of the occupational health nurse not familiar with the nuclear industries. The subject is dealt with under the following headings; Understanding atoms. What is meant by ionizing radiation. Types of ionizing radiation. Effects of radiation: long and short term somatic effects, genetic effects. Control of radiation: occupational exposure, women of reproductive age, medical aspects, principles of control. The occupational health nurse's role. Emergency arrangements: national arrangements for incidents involving radiation, action to be taken by the nurse. Decontamination procedures: external and internal contamination. (U.K.)

  12. Strong Near-Field Enhancement of Radiative Heat Transfer between Metallic Surfaces

    Science.gov (United States)

    Kralik, Tomas; Hanzelka, Pavel; Zobac, Martin; Musilova, Vera; Fort, Tomas; Horak, Michal

    2012-11-01

    Near-field heat transfer across a gap between plane-parallel tungsten layers in vacuo was studied experimentally with the temperature of the cold sample near 5 K and the temperature of the hot sample in the range 10-40 K as a function of the gap size d. At gaps smaller than one-third of the peak wavelength λm given by Wien’s displacement law, the near-field effect was observed. In comparison with blackbody radiation, hundred times higher values of heat flux were achieved at d≈1μm. Heat flux normalized to the radiative power transferred between black surfaces showed scaling (λm/d)n, where n≈2.6. This Letter describes the results of experiment and a comparison with present theory over 4 orders of magnitude of heat flux.

  13. Electrically tunable near-field radiative heat transfer via ferroelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yi; Boriskina, Svetlana V.; Chen, Gang, E-mail: gchen2@mit.edu [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-12-15

    We explore ways to actively control near-field radiative heat transfer between two surfaces that relies on electrical tuning of phonon modes of ferroelectric materials. Ferroelectrics are widely used for tunable electrical devices, such as capacitors and memory devices; however, their tunable properties have not yet been examined for heat transfer applications. We show via simulations that radiative heat transfer between two ferroelectric materials can be enhanced by over two orders of magnitude over the blackbody limit in the near field, and can be tuned as much as 16.5% by modulating the coupling between surface phonon polariton modes at the two surfaces via varying external electric fields. We then discuss how to maximize the modulation contrast for tunable thermal devices using the studied mechanism.

  14. On Fundamental Properties Of The Classical Electromagnetic Zero-point Radiation And Its Implications

    CERN Document Server

    Matsuoka, Y

    2005-01-01

    There is a classical theory that can explain various quantum phenomena including the Casimir effect, the van der Waals force, the blackbody radiation, and so forth [1]. The classical theory is called “stochastic electrodynamics (SED)” and only the difference from conventional classical physics is the choice of the boundary condition for Maxwell equations. It requires random electromagnetic radiation called “zero-point field (ZPF),” which exists throughout space even at zero temperature. Thus, the ZPF is thought to be an universal background field which corresponds to the vacuum ground state in the language of quantum electrodynamics. In this paper, the fundamental properties, especially the symmetries, of the ZPF are studied at first. It is found that the requirement of the Lorentz invariance of the field might be incompatible with the formulation of classical electrodynamics. Secondly, the behavior of unrestricted charged particle immersed in the ZPF is considered. Unl...

  15. Development of infrared spectral radiation measurement system of a non-luminous flame

    Institute of Scientific and Technical Information of China (English)

    Zhao Jin; Maohua Yang; Guibin Yuan; Jingmin Dai

    2005-01-01

    @@ The spectral radiation characteristic of a non-luminous flame is analyzed. The apparatus and the calibration procedure based on infrared emission spectrometry for measurements of the flame are introduced.The influence of background radiation and stray light on the measurement results could be reduced and suppressed by the design of thermolator and digital lock-in technique. A blackbody cavity was used as reference emission source to calibrate the system that completed absolute measurement. The spectral measurement range is 1-20 μm. The least measuring distance and the lowest power detected at the entrance pupil are 550 mm and 10-9 W/cm2, respectively. The experimental results show that the measure error is less than 10%.

  16. X-ray and gamma-ray astronomy. [origins of extraterrestrial radiation sources

    Science.gov (United States)

    1975-01-01

    Accomplishments in the fields of X-ray and gamma ray astronomy are discussed. Data obtained from IMP and OGO satellites are analyzed to determine the sources of interplanetary radiation bursts. The energy spectrum of cosmic gamma ray bursts as observed by IMP-6 is described. The application of cooling blackbody techniques as a method for examining cosmic gamma ray bursts is reported. The experimental results and theoretical interpretation of high energy diffuse gamma rays are investigated. The structure of the SAS-2 satellite is depicted and the accomplishments are examined. Other sources of gamma radiation to include galactic fermi, Cygnus X-1, supernovae, and the planet Jupiter are proposed. Data obtained from the Pioneer 10 space probe are presented in graph form.

  17. Radiation dosimetry and radiation biophysics

    International Nuclear Information System (INIS)

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with the design and measurement of physical parameters used in theory or to support biological experiments. The radiation biophysics program tests and uses the theoretical developments for experimental design, and provides information for further theoretical development through experiments on cellular systems

  18. Radiation dosimetry and radiation biophysics

    International Nuclear Information System (INIS)

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with design and measurement of those physical parameters used in the theory or to support biological experiments. The radiation biophysics program tests and makes use of the theoretical developments for experimental design. Also, this program provides information for further theoretical development through experiments on cellular systems

  19. Atoms, Radiation, and Radiation Protection

    CERN Document Server

    Turner, James E

    2007-01-01

    Atoms, Radiation, and Radiation Protection offers professionals and advanced students a comprehensive coverage of the major concepts that underlie the origins and transport of ionizing radiation in matter. Understanding atomic structure and the physical mechanisms of radiation interactions is the foundation on which much of the current practice of radiological health protection is based. The work covers the detection and measurement of radiation and the statistical interpretation of the data. The procedures that are used to protect man and the environment from the potential harmful effects of

  20. Radiation Chemistry

    Science.gov (United States)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  1. Design and Experimental Research of Solar Blackbody Cavity Absorber%太阳能黑腔集热器的设计及实验研究

    Institute of Scientific and Technical Information of China (English)

    张晓晖; 姜伟娜; 徐鉴鉴

    2014-01-01

    在黑体概念的基础上,设计了1种新型太阳能腔体集热器,并进行了实验。新型太阳能腔体集热器利用黑腔的高吸收率、泡沫板的良好隔热性以及玻璃板营造的温室效应,使得集热器的整体热损失明显下降,从而提高了集热效率。测试结果表明:集热器内介质为水时,平均温升为15.1℃,最大温升为21℃,热效率最低为53%。各项热损失计算结果表明:黑腔辐射造成的热损失最大,反射热损失和对流热损失很小。新型太阳能腔体集热器结构紧凑,单位体积的有效吸热面积较平板太阳能集热器和真空管太阳能集热器大。%On the basis of traditional cavity absorber,a kind of new solar cavity-heat receiver is designed.With advantage of high absorptivity and good thermal insulation,the whole heat loss gets smaller and can obtain high thermal efficiency.The result of the experiment shows that the mean temperature rise is 15.1℃ and the highest temperature rise is 21℃ when water is filled,and the thermal efficiency is 53% under present situa-tion.The result of the thermal loss calculation indicates that radiation heat loss accounts for the most,while reflection heat loss and convection heat loss is small.The compact design has bigger effective heat absorbing area per volume than flat plate solar collector and evacuated tubular collector.

  2. Radiation acoustics

    CERN Document Server

    Lyamshev, Leonid M

    2004-01-01

    Radiation acoustics is a developing field lying at the intersection of acoustics, high-energy physics, nuclear physics, and condensed matter physics. Radiation Acoustics is among the first books to address this promising field of study, and the first to collect all of the most significant results achieved since research in this area began in earnest in the 1970s.The book begins by reviewing the data on elementary particles, absorption of penetrating radiation in a substance, and the mechanisms of acoustic radiation excitation. The next seven chapters present a theoretical treatment of thermoradiation sound generation in condensed media under the action of modulated penetrating radiation and radiation pulses. The author explores particular features of the acoustic fields of moving thermoradiation sound sources, sound excitation by single high-energy particles, and the efficiency and optimal conditions of thermoradiation sound generation. Experimental results follow the theoretical discussions, and these clearl...

  3. Radiation carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1976-01-01

    The risk of iatrogenic tumors with radiation therapy is so outweighed by the benefit of cure that estimates of risk have not been considered necessary. However, with the introduction of chemotherapy, combined therapy, and particle radiation therapy, the comparative risks should be examined. In the case of radiation, total dose, fractionation, dose rate, dose distribution, and radiation quality should be considered in the estimation of risk. The biological factors that must be considered include incidence of tumors, latent period, degree of malignancy, and multiplicity of tumors. The risk of radiation induction of tumors is influenced by the genotype, sex, and age of the patient, the tissues that will be exposed, and previous therapy. With chemotherapy the number of cells at risk is usually markedly higher than with radiation therapy. Clearly the problem of the estimation of comparative risks is complex. This paper presents the current views on the comparative risks and the importance of the various factors that influence the estimation of risk.

  4. Radiation magnetohydrodynamic simulation of plasma formed on a surface by a megagauss field.

    Science.gov (United States)

    Esaulov, A A; Bauer, B S; Makhin, V; Siemon, R E; Lindemuth, I R; Awe, T J; Reinovsky, R E; Struve, K W; Desjarlais, M P; Mehlhorn, T A

    2008-03-01

    Radiation magnetohydrodynamic modeling is used to study the plasma formed on the surface of a cylindrical metallic load, driven by megagauss magnetic field at the 1MA Zebra generator (University of Nevada, Reno). An ionized aluminum plasma is used to represent the "core-corona" behavior in which a heterogeneous Z-pinch consists of a hot low-density corona surrounding a dense low-temperature core. The radiation dynamics model included simultaneously a self-consistent treatment of both the opaque and transparent plasma regions in a corona. For the parameters of this experiment, the boundary of the opaque plasma region emits the major radiation power with Planckian black-body spectrum in the extreme ultraviolet corresponding to an equilibrium temperature of 16 eV. The radiation heat transport significantly exceeds the electron and ion kinetic heat transport in the outer layers of the opaque plasma. Electromagnetic field energy is partly radiated (13%) and partly deposited into inner corona and core regions (87%). Surface temperature estimates are sensitive to the radiation effects, but the surface motion in response to pressure and magnetic forces is not. The general results of the present investigation are applicable to the liner compression experiments at multi-MA long-pulse current accelerators such as Atlas and Shiva Star. Also the radiation magnetohydrodynamic model discussed in the paper may be useful for understanding key effects of wire array implosion dynamics.

  5. GRAVITATIONAL RADIATION

    OpenAIRE

    SALTIK, Metin; Mustafa KURT; Mehmet KAYMAK

    1996-01-01

    According to classical electromagnetic theory, an accelerated charge or system of charges radiates electromagnetic waves. In a radio transmitter antenna charges are accelerated along the antenna and release electromagnetic waves, which is radiated at the velocity of light in the surrounding medium. All of the radio transmitters work on this principle today. In this study an analogy is established between the principles by which accelerated charge systems markes radiation and the accelerated m...

  6. Hawking radiation

    Science.gov (United States)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  7. Plume radiation

    Science.gov (United States)

    Dirscherl, R.

    1993-06-01

    The electromagnetic radiation originating from the exhaust plume of tactical missile motors is of outstanding importance for military system designers. Both missile- and countermeasure engineer rely on the knowledge of plume radiation properties, be it for guidance/interference control or for passive detection of adversary missiles. To allow access to plume radiation properties, they are characterized with respect to the radiation producing mechanisms like afterburning, its chemical constituents, and reactions as well as particle radiation. A classification of plume spectral emissivity regions is given due to the constraints imposed by available sensor technology and atmospheric propagation windows. Additionally assessment methods are presented that allow a common and general grouping of rocket motor properties into various categories. These methods describe state of the art experimental evaluation techniques as well as calculation codes that are most commonly used by developers of NATO countries. Dominant aspects influencing plume radiation are discussed and a standardized test technique is proposed for the assessment of plume radiation properties that include prediction procedures. These recommendations on terminology and assessment methods should be common to all employers of plume radiation. Special emphasis is put on the omnipresent need for self-protection by the passive detection of plume radiation in the ultraviolet (UV) and infrared (IR) spectral band.

  8. GRAVITATIONAL RADIATION

    Directory of Open Access Journals (Sweden)

    Metin SALTIK

    1996-03-01

    Full Text Available According to classical electromagnetic theory, an accelerated charge or system of charges radiates electromagnetic waves. In a radio transmitter antenna charges are accelerated along the antenna and release electromagnetic waves, which is radiated at the velocity of light in the surrounding medium. All of the radio transmitters work on this principle today. In this study an analogy is established between the principles by which accelerated charge systems markes radiation and the accelerated mass system, and the systems cousing gravitational radiation are investigated.

  9. Radiation protection

    International Nuclear Information System (INIS)

    A NRPB leaflet in the 'At-a-Glance' series explains in a simple but scientifically accurate way what radiation is, the biological effects and the relative sensitivity of different parts of the human body. The leaflet then discusses radiation protection principles, radiation protection in the UK and finally the effectiveness of this radiation protection as judged by a breakdown of the total dose received by an average person in the UK, a heavy consumer of Cumbrian seafood, an average nuclear industry worker and an average person in Cornwall. (UK)

  10. Radiation medicine

    International Nuclear Information System (INIS)

    This booklet has been produced by UKAEA and the Marie Curie Memorial Foundation to give some basic information about what radiation is and how it is used in day to day diagnosis and treatment. It will be of interest to people undergoing treatment, their relatives and friends, and anyone who wants to know more about this important area. After a brief historical introduction the booklet explains what radiation is, the natural and man-made sources of radiation, how it is produced and how X-rays are used in medical diagnosis and treatment. The radiation protection measures taken and safety standards followed are mentioned. (author)

  11. Earth Radiation Budget Experiment scanner radiometric calibration results

    Science.gov (United States)

    Lee, Robert B., III; Gibson, M. A.; Thomas, Susan; Meekins, Jeffrey L.; Mahan, J. R.

    1990-01-01

    The Earth Radiation Budget Experiment (ERBE) scanning radiometers are producing measurements of the incoming solar, earth/atmosphere-reflected solar, and earth/atmosphere-emitted radiation fields with measurement precisions and absolute accuracies, approaching 1 percent. ERBE uses thermistor bolometers as the detection elements in the narrow-field-of-view scanning radiometers. The scanning radiometers can sense radiation in the shortwave, longwave, and total broadband spectral regions of 0.2 to 5.0, 5.0 to 50.0, and 0.2 to 50.0 micrometers, respectively. Detailed models of the radiometers' response functions were developed in order to design the most suitable calibration techniques. These models guided the design of in-flight calibration procedures as well as the development and characterization of a vacuum-calibration chamber and the blackbody source which provided the absolute basis upon which the total and longwave radiometers were characterized. The flight calibration instrumentation for the narror-field-of-view scanning radiometers is presented and evaluated.

  12. Radiation oncology

    International Nuclear Information System (INIS)

    The Radiation Oncology Division has had as its main objectives both to operate an academic training program and to carry out research on radiation therapy of cancer. Since fiscal year 1975, following a directive from ERDA, increased effort has been given to research. The research activities have been complemented by the training program, which has been oriented toward producing radiation oncologists, giving physicians short-term experience in radiation oncology, and teaching medical students about clinical cancer and its radiation therapy. The purpose of the research effort is to improve present modalities of radiation therapy of cancer. As in previous years, the Division has operated as the Radiation Oncology Program of the Department of Radiological Sciences of the University of Puerto Rico School of Medicine. It has provided radiation oncology support to patients at the University Hospital and to academic programs of the University of Puerto Rico Medical Sciences Campus. The patients, in turn, have provided the clinical basis for the educational and research projects of the Division. Funding has been primarily from PRNC (approx. 40%) and from National Cancer Institute grants channeled through the School of Medicine (approx. 60%). Special inter-institutional relationships with the San Juan Veterans Administration Hospital and the Metropolitan Hospital in San Juan have permitted inclusion of patients from these institutions in the Division's research projects. Medical physics and radiotherapy consultations have been provided to the Radiotherapy Department of the VA Hospital

  13. Synchrotron radiation

    International Nuclear Information System (INIS)

    The paper on Synchrotron Radiation contains the appendix to the Daresbury Annual Report 1987/88. The appendix is mainly devoted to the scientific progress reports on the work at the Synchrotron Radiation Source in 1987/8. The parameters of the Experimental Stations and the index to the Scientific Reports are also included in the appendix. (U.K.)

  14. Radiation detector

    Science.gov (United States)

    Fultz, Brent T.

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  15. Radiation Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Castor, J I

    2003-10-16

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is

  16. Radiation Therapy

    Science.gov (United States)

    ... therapy. At this time, you will have a physical exam , talk about your medical history , and maybe have imaging tests . Your doctor or nurse will discuss external beam radiation therapy, its benefits and side effects, and ways you can care ...

  17. Synchrotron radiation

    International Nuclear Information System (INIS)

    A detailed account of the research work associated with the Synchrotron Radiation Source at Daresbury Laboratory, United Kingdom, in 1984/85, is presented in the Appendix to the Laboratory's Annual Report. (U.K.)

  18. Radiation damage

    CERN Document Server

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  19. Radiation curing

    International Nuclear Information System (INIS)

    In the beginning of the seventies the two types of radiation sources applied in industrial processes, electron radiation and UV, had been given rather optimistic forecasts. While UV could succeed in the field of panel and film coating, electron radiation curing seems to gain success in quite new fields of manufacturing. The listing of the suggested applications of radiation curing and a comparison of both advantages and disadvantages of this technology are followed by a number of case studies emphasizing the features of these processes and giving some examplary calculations. The data used for the calculations should provide an easy calculation of individual manufacturing costs if special production parameters, investment or energy costs are employed. (Author)

  20. Synchrotron radiation

    International Nuclear Information System (INIS)

    A report is given on the work involving the Synchrotron Radiation Division of the Daresbury Laboratory during the period January 1981 - March 1982. Development of the source, beamlines and experimental stations is described. Progress reports from individual investigators are presented which reveal the general diversity and interdisciplinary nature of the research which benefits from access to synchrotron radiation and the associated facilities. Information is given on the organisation of the Division and publications written by the staff are listed. (U.K.)

  1. Radiation emergencies

    International Nuclear Information System (INIS)

    Elaborate precautions are taken in the design, construction and operation of nuclear installations. Even then, there always remains the possibility, however small, of accidents. A radiation emergency can be defined as any abnormal situation following an incident/accident which may result in either unusually large radiation fields in any plant/area or large release of air or liquid borne radioactivity leading to widespread contamination of areas

  2. Radiation Entomology

    OpenAIRE

    A. Nagaratnam

    2000-01-01

    The article reviews the use of radiation and radioisotopes in entomology with special reference to the use of radiotracers in entomological studies and the use of sterile insect techniques in the control of insect pests. It also presents' a profile of Shri Koshy and his contributions to defence entomology, including design of an efficient device for the rearing of cockroaches, evaluation of different repellents against leeches, laboratory and pilot field studies on the use of radiation-steril...

  3. Synchrotron radiation

    International Nuclear Information System (INIS)

    The paper on synchrotron radiation is the appendix to the Daresbury (United Kingdom) annual report, 1985/86. The bulk of the volume is made up of the progress reports for the work carried out during the year under review using the Synchrotron Radiation Source (SRS) at Daresbury. The Appendix also contains: the scientific programmes at the the SRS, progress on beamlines, instrumentation and computing developments, and activities connected with accelerator development. (U.K.)

  4. Numerical solution of the radiative transfer equation: X-ray spectral formation from cylindrical accretion onto a magnetized neutron star

    CERN Document Server

    Farinelli, R; Romano, P; Titarchuk, L

    2011-01-01

    Predicting the emerging X-ray spectra in several astrophysical objects is of great importance, in particular when the observational data are compared with theoretical models. To this aim, we have developed an algorithm solving the radiative transfer equation in the Fokker-Planck approximation when both thermal and bulk Comptonization take place. The algorithm is essentially a relaxation method, where stable solutions are obtained when the system has reached its steady-state equilibrium. We obtained the solution of the radiative transfer equation in the two-dimensional domain defined by the photon energy E and optical depth of the system tau using finite-differences for the partial derivatives, and imposing specific boundary conditions for the solutions. We treated the case of cylindrical accretion onto a magnetized neutron star. We considered a blackbody seed spectrum of photons with exponential distribution across the accretion column and for an accretion where the velocity reaches its maximum at the stellar...

  5. "The Theory of Heat Radiation" Revisited: A Commentary on the Validity of Kirchhoff's Law of Thermal Emission and Max Planck's Claim of Universality

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2015-04-01

    Full Text Available Affirming Kirchhoff’s Law of thermal emission, Max Planck conferred upon his own equation and its constants, h and k , universal significance. All arbitrary cavities were said to behave as blackbodies. They were thought to contain b lack, or normal radiation, which depended only upon temperature and frequency of observation, irrespective of the nature of the cavity walls. Today, laboratory blackbodies a re specialized, heated devices whose interior walls are lined with highly absorptive surfaces, such as graphite, soot, or other sophisticated materials. Such evidence repeatedly calls into question Kirchhoff’s Law, as nothing in the laboratory is independent of the nature of the walls. By focusing on Max Planck’s classic text, “ The Theory of Heat Radiation ’, it can be demonstrated that the German physicist was unable to properly justify Kirchhoff’s Law. At every turn, he was confronted with the fact that materials possess frequency dependent reflectivity and absorptivity, but he often chose to sidestep these realities. He used polarized light to derive Kirchhoff’s Law, when it is well known that blackbody radiation is never polar- ized. Through the use of an element, d σ , at the bounding surface between two media, he reached the untenable position that arbitrary materials have the same reflective prop- erties. His Eq.40 ( ρ = ρ ′ , constituted a dismissal of experimental reality. It is evident that if one neglects reflection, then all cavities must be black. Unable to ensure that perfectly reflecting cavities can be filled with black radiation, Planck inserted a minute carbon particle, which he qualified as a “catalyst”. In fact, it was acting as a perfect absorber, fully able to provide, on its own, the radiation sought. In 1858, Balfour Stew- art had outlined that the proper treatment of cavity radiation must include reflection. Yet, Max Planck did not cite the Scottish scientist. He also d id not correctly address

  6. Brain radiation - discharge

    Science.gov (United States)

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  7. Classical Zero-Point Radiation and Relativity: The Problem of Atomic Collapse Revisited

    Science.gov (United States)

    Boyer, Timothy H.

    2016-07-01

    The physicists of the early twentieth century were unaware of two aspects which are vital to understanding some aspects of modern physics within classical theory. The two aspects are: (1) the presence of classical electromagnetic zero-point radiation, and (2) the importance of special relativity. In classes in modern physics today, the problem of atomic collapse is still mentioned in the historical context of the early twentieth century. However, the classical problem of atomic collapse is currently being treated in the presence of classical zero-point radiation where the problem has been transformed. The presence of classical zero-point radiation indeed keeps the electron from falling into the Coulomb potential center. However, the old collapse problem has been replaced by a new problem where the zero-point radiation may give too much energy to the electron so as to cause "self-ionization." Special relativity may play a role in understanding this modern variation on the atomic collapse problem, just as relativity has proved crucial for a classical understanding of blackbody radiation.

  8. Radiation myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, I.A.; Myers, S.J.

    1976-02-01

    Myelopathy secondary to radiation is a relatively uncommon entity which was reported initially in 1941 by Ahlbom. From a total of 65 patients who were seen in our spinal injury clinic during the past four years, three patients have received a diagnosis of radiation myelopathy. This is 4.6 percent of the total number. The case histories of two patients with radiation myelopathy are presented. The clinical and pathologic features are discussed. Since the three patients with this diagnosis whose cases are followed in the clinic are still alive, the second case that is reported is taken from the files of the pathology department so that autopsy and histologic data also can be presented.

  9. Radiation myelopathy

    International Nuclear Information System (INIS)

    Myelopathy secondary to radiation is a relatively uncommon entity which was reported initially in 1941 by Ahlbom. From a total of 65 patients who were seen in our spinal injury clinic during the past four years, three patients have received a diagnosis of radiation myelopathy. This is 4.6 percent of the total number. The case histories of two patients with radiation myelopathy are presented. The clinical and pathologic features are discussed. Since the three patients with this diagnosis whose cases are followed in the clinic are still alive, the second case that is reported is taken from the files of the pathology department so that autopsy and histologic data also can be presented

  10. Radiation gauge

    International Nuclear Information System (INIS)

    Fuji Electric has developed a pipe wall thinning detection device, which operates based on radiation gauge technology, for use in nuclear power plants and thermoelectric power plants. The radiation from the pipe wall thinning detection device, which can be used even during the plant operation, can penetrate heat insulation material. The device consists of detector and radiation source, and can detect the thickness of pipes (less than 500 mm in external diameter and less than 50 mm in thickness) with 2% reproducibility (with a measurement time of several minutes), based on the attenuation rate. Operation is easy and efficient since there is no need to remove the heat insulation and it is easy to mount the device, thus enabling more effective detection. (author)

  11. The bumpy road Max Planck from radiation theory to the quantum (1896-1906)

    CERN Document Server

    Badino, Massimiliano

    2015-01-01

    This book examines the different areas of knowledge, traditions, and conceptual resources that contributed to the building of Max Planck’s theory of radiation. It presents an insightful comparative analysis that not only sheds light upon a fundamental chapter in the history of modern physics, but also enlarges our understanding of how theoreticians work. Coverage offers a deep investigation into the technical aspects behind the theory and extends in time the notion of quantum revolution. It also presents a full-fledged discussion of the combinatorial part of Planck’s theory and places emphasis on the epistemological role of mathematical practices. By painstakingly reconstructing both the electromagnetic and the combinatorial part of Planck’s black-body theory, the author shows how some apparently merely technical resources, such as the Fourier series, effectively contributed to shape the final form of Planck’s theory. For decades, historians have debated the conditions of possibility of Max Planck’s...

  12. Measurement of the large-scale anisotropy of the cosmic background radiation at 3mm

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, G.L.

    1983-12-01

    A balloon-borne differential radiometer has measured the large-scale anisotropy of the cosmic background radiation (CBR) with high sensitivity. The antenna temperature dipole anistropy at 90 GHz (3 mm wavelength) is 2.82 +- 0.19 mK, corresponding to a thermodynamic anistropy of 3.48 +- mK for a 2.7 K blackbody CBR. The dipole direction, 11.3 +- 0.1 hours right ascension and -5.7/sup 0/ +- 1.8/sup 0/ declination, agrees well with measurements at other frequencies. Calibration error dominates magnitude uncertainty, with statistical errors on dipole terms being under 0.1 mK. No significant quadrupole power is found, placing a 90% confidence-level upper limit of 0.27 mK on the RMS thermodynamic quadrupolar anistropy. 22 figures, 17 tables.

  13. Tailored long range forces on polarizable particles by collective scattering of broadband radiation

    CERN Document Server

    Holzmann, Daniela

    2016-01-01

    Collective coherent light scattering by polarizable particles creates surprisingly strong, long range inter-particle forces originating from interference of the light scattered by different particles. While for monochromatic laser beams this interaction decays with the inverse distance, we show here that in general the effective interaction range and geometry can be controlled by the illumination bandwidth and geometry. As generic example we study the modifications inter-particle forces within a 1D chain of atoms trapped in the field of a confined optical nanofiber mode. For two particles we find short range attraction as well as optical binding at multiple distances. The range of stable distances shrinks with increasing light bandwidth and for a very large bandwidth field as e.g. blackbody radiation we find a strongly attractive potential up to a critical distance beyond which the force gets repulsive. Including multiple scattering can even lead to the appearance of a stable configuration at a large distance...

  14. Radiation toxicology

    International Nuclear Information System (INIS)

    Extensive studies on both human and experimental animal populations have provided information that allow radiation protection standards to be set with greater confidence than for most if not all other carcinogenic agents. Furthermore, both international and national advisory bodies are continually updating the risk estimates and the standards as new information is available. However, it is clear that models are needed that take into account the multistage nature of carcinogenesis. Studies in both ionizing and ultraviolet radiation carcinogenesis are more valuable to the general problem of elucidating the mechanisms involved in cancer than is indicated by the amount of work or support for this field of research

  15. Radiation Entomology

    Directory of Open Access Journals (Sweden)

    A. Nagaratnam

    2000-10-01

    Full Text Available The article reviews the use of radiation and radioisotopes in entomology with special reference to the use of radiotracers in entomological studies and the use of sterile insect techniques in the control of insect pests. It also presents' a profile of Shri Koshy and his contributions to defence entomology, including design of an efficient device for the rearing of cockroaches, evaluation of different repellents against leeches, laboratory and pilot field studies on the use of radiation-sterilised males for the control of the mosquito Culex fatigans.

  16. Radiation toxicology

    International Nuclear Information System (INIS)

    The extensive studies on both human and experimental animal populations have provided information that allows radiation protection standards to be set with greater confidence than for most if not all other carcinogenic agents. Furthermore, both international and national advisory bodies are continually updating the risk estimates and the standards as new information is available. However, it is clear that we need models that take into account the multistage nature of carcinogenesis. Studies in both ionizing and ultraviolet radiation carcinogenesis are more valuable to the general problem of elucidating the mechanisms involved in cancer than is indicated by the amount of work or support for this field of research

  17. Radiation dosimetry

    International Nuclear Information System (INIS)

    Film is one of the most simple ways to detect radiation although for film as dosimeters a careful attention is required in many aspects, such as emulsion characteristics, film response capacity processing techniques and interpretation of the exposition. Surpassing these factors the film dosimeter is the most reliable

  18. Radiation dosage

    International Nuclear Information System (INIS)

    Radiation dosage at Bikini Atoll is the result of current soil contamination, a relic of the nuclear weapons testing program of some 30 years ago. The principal contaminants today and some of their physical properties are listed: cesium-137, strontium-90, plutonium -239, 240 and americium-241. Cobalt-60 contributes less than 1 to the dose and is not considered significant. A resident of the atoll would accumulate radiation dose (rem) in two ways -- by exposure to radiation emanating from the ground and vegetation, and by exposure to radiation released in the spontaneous decay of radionuclides that have entered his body during the ingestion of locally grown foods. The latter process would account for some 90% of the dose; cesium-137 would be responsible for 0 90% of it. Since BARC's method of estimating dosage differs in some respects from that employed by the Lawrence Livermore National Laboratory (LLNL), (Ref.1, LLNL 1982) we are presenting our method in detail. The differences have two sources. First, the numbers used by BARC for the daily ingestion of radionuclides via the diet are higher than LLNL's. Second, BARC's calculation of dose from radionuclide intake utilizes the ICRP system. The net result is that BARC doses are consistently higher than LLNL doses, and in this respect are more conservative

  19. Radiation Technology

    International Nuclear Information System (INIS)

    The conference was organized to evaluate the application directions of radiation technology in Vietnam and to utilize the Irradiation Centre in Hanoi with the Co-60 source of 110 kCi. The investigation and study of technico-economic feasibility for technology development to various items of food and non-food objects was reported. (N.H.A)

  20. Radiation protection

    CERN Multimedia

    Radioactive Shipping Service

    2005-01-01

    The section of the radiation protection group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tél. 73171

  1. Radiation protection

    CERN Multimedia

    2005-01-01

    The section of the Radiation Protection Group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tél. 73171

  2. Radiation protection

    CERN Multimedia

    2005-01-01

    The section of the Radiation Protection Group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tel. 73171

  3. Near-field thermal radiation between homogeneous dual uniaxial electromagnetic metamaterials

    Science.gov (United States)

    Chang, Jui-Yung; Basu, Soumyadipta; Yang, Yue; Wang, Liping

    2016-06-01

    Recently, near-field thermal radiation has attracted much attention in several fields since it can exceed the Planck blackbody limit through the coupling of evanescent waves. In this work, near-field radiative heat transfer between two semi-infinite dual uniaxial electromagnetic metamaterials with two different material property sets is theoretically analyzed. The near-field radiative heat transfer is calculated using fluctuational electrodynamics incorporated with anisotropic wave optics. The underlying mechanisms, namely, magnetic hyperbolic mode, magnetic surface polariton, electrical hyperbolic mode, and electrical surface polariton, between two homogeneous dual uniaxial electromagnetic metamaterials are investigated by examining the transmission coefficient and the spectral heat flux. The effect of vacuum gap distance is also studied, which shows that the enhancement at smaller vacuum gap is mainly due to hyperbolic mode and surface plasmon polariton modes. In addition, the results show that the contribution of s-polarized waves is significant and should not be excluded due to the strong magnetic response regardless of vacuum gap distances. The fundamental understanding and insights obtained here will facilitate the finding and application of novel materials for near-field thermal radiation.

  4. Radiation pager

    International Nuclear Information System (INIS)

    Methods of interdicting nuclear materials to date have favored the use of large portal detectors at choke points, or hand carried instruments used by trained personnel for conducting spot searches. Although these methods are effective in some instances, it is often impractical to insert choke points at busy traffic areas, and it is not cost effective to maintain a force of skilled operators whose focus is nuclear interdiction. Recent technology developments are causing profound changes in the philosophy and methods employed for interdicting nuclear materials. Breakthrough advances in the miniaturization of detectors and low power electronics have made possible a new class of small gamma-ray radiation detectors, roughly the size of a message pager, with unprecedented sensitivity for their size. These instruments, named Radiation PagersTM, are ideally suited for use by untrained individual law enforcement personnel and emergency responders in the course of their regular duties. New tactics that utilize a radiation detector worn by every officer are creating a moving curtain of detection with a significantly higher likelihood of locating illicit nuclear contraband. These individual detectors also provide each officer with a high level of confidence that they are not being unknowingly irradiated in the course of their work. (author)

  5. Radiation preservation of maize

    International Nuclear Information System (INIS)

    Radiation preservation of maize was carried out. Radiation doses and sources, shielding materials, packaging materials, chemical radiation effects, biological radiation effects, were discussed. Experimental methods, samples and accessories were also presented. (SMN)

  6. Risk Factors: Radiation

    Science.gov (United States)

    Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage DNA and cause cancer. Ionizing radiation includes radon, x-rays, gamma rays, and other forms of high-energy radiation.

  7. Perspective of radiation processing

    International Nuclear Information System (INIS)

    The area of the applications of radiation techniques is very wide. This paper only relates to the applications of radiation techniques in industries including radiation chemical industry, radiation processing of foods and environmental protection by radiation, but the nuclear instruments and the instrumentations of radiation are out-side of our study. (author)

  8. Radiation hormesis

    International Nuclear Information System (INIS)

    The author defines hormesis as the stimulus given to any organism by non-toxic concentrations of toxic substances and gives a few examples of the experimental evidence for the existence of radiation hormesis. The most probable explanation for its working lies not in the education of the nuclear repair system but in the education of the immune system, which is very complex and is capable of learning to deal with a variety of threats to living cells. The effects of both high LET and low LET particles are considered. (author)

  9. Synchrotron radiation

    International Nuclear Information System (INIS)

    This report details the activities in synchrotron radiation and related areas at Daresbury Laboratory during 1989/90. The number and scope of the scientific reports submitted by external users and in-house staff is a reflection of the large amount of scheduled beamtime and high operating efficiency achieved at the Synchrotron Radiation Source (SRS) during the past year. Over 4000 hours of user beam were available, equivalent to about 80% of the total scheduled time. Many of the reports collected here illustrate the increasing technical complexity of the experiments now being carried out at Daresbury. Provision of the appropriate technical and scientific infrastructure and support is a continuing challenge. The development of the Materials Science Laboratory together with the existing Biological Support Laboratory will extend the range of experiments which can be carried out on the SRS. This will particularly facilitate work in which the sample must be prepared or characterised immediately before or during an experiment. The year 1989/90 has also seen a substantial upgrade of several stations, especially in the area of x-ray optics. Many of the advantages of the High Brightness Lattice can only be exploited effectively with the use of focusing optics. As the performance of these stations improves, the range of experiments which are feasible on the SRS will be extended significantly. (author)

  10. Ultraviolet radiation

    International Nuclear Information System (INIS)

    Ultraviolet radiation (UVR) from the sun or artificial sources is reflected or transmitted at the surface of the skin, about 5% of normally incident rays being directly reflected. The transmitted fraction is scattered, photochemically absorbed or dissipated as heat within the skin, or passes from it to contribute to the variable total amount of reflected and transmitted radiation. The UVR absorbers in skin are not definitely known, but DNA is a definite target and probably lipoprotein membranes, RNA, proteins, mucopolysaccharides, elastin and collagen. Photochemical or free radical damage to absorber or nearby organelles leads to pharmacological, ultrastructural, histological and clinical changes. Most frequent DNA damage is pyrimidine dimer formation, apparently inhibiting cell function and replication. This is largely enzymatically repaired in man in the dark by excision repair, post-replication repair and possible other enzymatic mechanisms, and at least in some organisms by light-induced photoreactivation repair. UVR exposure causes well recognized acute and chronic clinical syndromes in man. These are discussed in this paper

  11. Radiation risks and radiation protection at CRNL

    International Nuclear Information System (INIS)

    Radiation exposure is an occupational hazard at CRNL. The predicted health effects of low levels of radiation are described and compared with other hazards of living. Data related to the health of radiation workers are also considered. Special attention is given to the expected effects of radiation on the unborn child. Measures taken to protect CRNL employees against undue occupational exposure to radiation are noted

  12. Recent progress in thermodynamics of radiation——exergy of radiation, effective temperature of photon and entropy constant of photon

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The recent progress on thermodynamic properties of spectral radiant energy in the field of thermodynamics of radiation is reviewed. The effective temperature of photon Tλ representing the energy quality of photon is introduced. The relation between Tλ and the wavelength λ is given as λTλ =c3=5.33016×10?3 m·K. The en- tropy constant of photon is given as sλ=3.72680×10?23 J/K. The exergy, entropy and enthalpy of the spectral blackbody radiation, the equilibrium cavity radiation, the radiation flux in open system are discussed by using Tλ and sλ, as well as the en- tropy change in the process of the state transformation of photon gas. By analyzing the exergy of spectral radiation, the exergy efficiency of spectral radiant energy available for photosynthesis is proved to be higher than that of light energy. The method for the irreversible loss of exergy calculation in radiant energy converters is also discussed.

  13. Hawking radiation and the Stefan-Boltzmann law: The effective radius of the black-hole quantum atmosphere

    CERN Document Server

    Hod, Shahar

    2016-01-01

    It has recently been suggested [S. B. Giddings, Phys. Lett. B {\\bf 754}, 39 (2016)] that the Hawking black-hole radiation spectrum originates from an effective quantum "atmosphere" which extends well outside the black-hole horizon. In particular, comparing the Hawking radiation power of a $(3+1)$-dimensional Schwarzschild black hole of horizon radius $r_{\\text{H}}$ with the familiar Stefan-Boltzmann radiation power of a $(3+1)$-dimensional flat space perfect blackbody emitter, Giddings concluded that the source of the Hawking semi-classical black-hole radiation is a quantum region outside the Schwarzschild black-hole horizon whose effective radius $r_{\\text{A}}$ is characterized by the relation $\\Delta r\\equiv r_{\\text{A}}-r_{\\text{H}}\\sim r_{\\text{H}}$. It is of considerable physical interest to test the general validity of Giddings's intriguing conclusion. To this end, we study the Hawking radiation of $(D+1)$-dimensional Schwarzschild black holes. We find that the dimensionless radii $r_{\\text{A}}/r_{\\text...

  14. Modelling the dust emission from dense interstellar clouds: disentangling the effects of radiative transfer and dust properties

    CERN Document Server

    Ysard, N; Demyk, K; Guillet, V; Abergel, A; Bernard, J -P; Malinen, J; Mény, C; Montier, L; Paradis, D; Ristorcelli, I; Verstraete, L

    2012-01-01

    With Planck and Herschel, we now have the spectral coverage and angular resolution required to observe dense and cold molecular clouds. As these clouds are optically thick at short wavelength but optically thin at long wavelength, it is tricky to conclude anything about dust properties without a proper treatment of the radiative transfer (RT). Our aim is to disentangle the effects of RT and of dust properties on the variations in the dust emission to provide observers with keys to analyse the emission arising from dense clouds. We model cylindrical clouds, illuminated by the ISRF, and carry out full RT calculations. Dust temperatures are solved using DustEM for amorphous carbons and silicates, grains coated with carbon mantles, and mixed aggregates of carbon and silicate. We allow variations of the grain optical properties with wavelength and temperature. We determine observed colour temperatures, T, and emissivity spectral indices, beta, by fitting the dust emission with modified blackbodies, to compare our ...

  15. Radiation biophysics

    International Nuclear Information System (INIS)

    Summaries of research projects conducted during 1978 and 1979 are presented. The overall thrust of the research is aimed at understanding the effects of radiation on organisms. Specific subject areas include: the effects of heavy-particle beam nuclear interactions in tissue on dosimetry; tracer studies with radioactive fragments of heavy-ion beams; the effects of heavy/ions on human kidney cells and Chinese hamster cells; the response of a rhabdomyosarcoma tumor system in rats to heavy-ion beams; the use of heavy charged particles in radiotherapy of human cancer; heavy-ion radiography; the biological effects of high magnetic fields; central nervous system neurotoxicity; and biophysical studies on cell membranes

  16. Environmental radiation

    International Nuclear Information System (INIS)

    The types of ionizing radiations from the atomic nucleus are explained, such as the beams alpha, beta and gamma. The definitions of spectrometry and nuclear traces have been included.The study presents two researches realized in Costa Rica on the radioactive nuclear and artificial elements in the environment. The first shown is the analysis of coastal sediments where explains which are radioactive artificial isotopes and the pollution that occurs in food, coastal sediments, fertilizers, the soil, the water and the air. Within the analysis techniques are the gamma spectrometry, alpha spectrometry and nuclear strokes. Among the conclusions of this initial investigation is shown that at Punta Leona descendants of Uranium and Thorium present lower concentrations in relation to the gulf and its variations are not important. In the following study the radon gas is analyzed in the human environment where is determined that it is the second generator that causes cancer in lungs after the tobacco. This work indicates that the doses come from natural and artificial sources of radiation for the public are a whole of 2.7 mSv/year, information provided by the UNSCEAR, 2000. The radon gas is inert and radioactive of atomic number 86, includes 23 isotopes and 3 natural isotopes. The radon is everywhere, as are houses and buildings, in Costa Rica it is located in old homes with little ventilation. It describes the equipment used for the detection of radon gas in the environment. Within the conclusions radon gas is concentrated in confined spaces which can be harmful to health. It is determined that enough ventilation in places of high concentrations of radon is important. Finally it is recommended to monitor the sites where can be detected high concentrations of radon and that they have important influx of people

  17. Interaction of surface plasmon polaritons in heavily doped GaN microstructures with terahertz radiation

    Science.gov (United States)

    Melentev, G. A.; Shalygin, V. A.; Vorobjev, L. E.; Panevin, V. Yu.; Firsov, D. A.; Riuttanen, L.; Suihkonen, S.; Korotyeyev, V. V.; Lyaschuk, Yu. M.; Kochelap, V. A.; Poroshin, V. N.

    2016-03-01

    We present the results of experimental and theoretical studies of the surface plasmon polariton excitations in heavily doped GaN epitaxial layers. Reflection and emission of radiation in the frequency range of 2-20 THz including the Reststrahlen band were investigated for samples with grating etched on the sample surface, as well as for samples with flat surface. The reflectivity spectrum for p-polarized radiation measured for the sample with the surface-relief grating demonstrates a set of resonances associated with excitations of different surface plasmon polariton modes. Spectral peculiarities due to the diffraction effect have been also revealed. The characteristic features of the reflectivity spectrum, namely, frequencies, amplitudes, and widths of the resonance dips, are well described theoretically by a modified technique of rigorous coupled-wave analysis of Maxwell equations. The emissivity spectra of the samples were measured under epilayer temperature modulation by pulsed electric field. The emissivity spectrum of the sample with surface-relief grating shows emission peaks in the frequency ranges corresponding to the decay of the surface plasmon polariton modes. Theoretical analysis based on the blackbody-like radiation theory well describes the main peculiarities of the observed THz emission.

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

    International Nuclear Information System (INIS)

    Z-pinches created using the Z accelerator generate approximately220 TW, 1.7 MJ radiation pulses that heat large (approximately10 cm3) 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

  19. Self-consistent Optomechanical Dynamics and Radiation Forces in Thermal Light Fields

    International Nuclear Information System (INIS)

    We discuss two different aspects of the mechanical interaction between neutral matter and electromagnetic radiation.The first part addresses the complex dynamics of an elastic dielectric deformed by optical forces. To do so we use a one-dimensional model describing the medium by an array of beam splitters such that the interaction with the incident waves can be described with a transfer-matrix approach. Since the force on each individual beam splitter is known we thus obtain the correct volumetric force density inside the medium. Sending a light field through an initially homogeneous dielectric then results in density modulations which in turn alter the optical properties of this medium.The second part is concerned with mechanical light-effects on atoms in thermal radiation fields. At hand of a generic setup of an atom interacting with a hot sphere emitting blackbody radiation we show that the emerging gradient force may surpass gravity by several orders of magnitude. The strength of the repulsive scattering force strongly depends on the spectrum of the involved atoms and can be neglected in some setups. A special emphasis lies on possible implications on astrophysical scenarios where the interactions between heated dust and atoms, molecules or nanoparticles are of crucial interest. (author)

  20. Shape-Independent Limits to Near-Field Radiative Heat Transfer.

    Science.gov (United States)

    Miller, Owen D; Johnson, Steven G; Rodriguez, Alejandro W

    2015-11-13

    We derive shape-independent limits to the spectral radiative heat transfer rate between two closely spaced bodies, generalizing the concept of a blackbody to the case of near-field energy transfer. Through conservation of energy and reciprocity, we show that each body of susceptibility χ can emit and absorb radiation at enhanced rates bounded by |χ|(2)/Im χ, optimally mediated by near-field photon transfer proportional to 1/d(2) across a separation distance d. Dipole-dipole and dipole-plate structures approach restricted versions of the limit, but common large-area structures do not exhibit the material enhancement factor and thus fall short of the general limit. By contrast, we find that particle arrays interacting in an idealized Born approximation (i.e., neglecting multiple scattering) exhibit both enhancement factors, suggesting the possibility of orders-of-magnitude improvement beyond previous designs and the potential for radiative heat transfer to be comparable to conductive heat transfer through air at room temperature, and significantly greater at higher temperatures.

  1. Near-field radiation between graphene-covered carbon nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Richard Z.; Liu, Xianglei; Zhang, Zhuomin M., E-mail: zhuomin.zhang@me.gatech.edu [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

    2015-05-15

    It has been shown that at small separation distances, thermal radiation between hyperbolic metamaterials is enhanced over blackbodies. This theoretical study considers near-field radiation when graphene is covered on the surfaces of two semi-infinite vertically aligned carbon nanotube (VACNT) arrays separated by a sub-micron vacuum gap. Doped graphene is found to improve photon tunneling in a broad hyperbolic frequency range, due to the interaction with graphene-graphene surface plasmon polaritons (SPP). In order to elucidate the SPP resonance between graphene on hyperbolic substrates, vacuum-suspended graphene sheets separated by similar gap distances are compared. Increasing the Fermi energy through doping shifts the spectral heat flux peak toward higher frequencies. Although the presence of graphene on VACNT does not offer huge near-field heat flux enhancement over uncovered VACNT, this study identifies conditions (i.e., gap distance and doping level) that best utilize graphene to augment near-field radiation. Through the investigation of spatial Poynting vectors, heavily doped graphene is found to increase penetration depths in hyperbolic modes and the result is sensitive to the frequency regime. This study may have an impact on designing carbon-based vacuum thermophotovoltaics and thermal switches.

  2. Near-field radiation between graphene-covered carbon nanotube arrays

    Directory of Open Access Journals (Sweden)

    Richard Z. Zhang

    2015-05-01

    Full Text Available It has been shown that at small separation distances, thermal radiation between hyperbolic metamaterials is enhanced over blackbodies. This theoretical study considers near-field radiation when graphene is covered on the surfaces of two semi-infinite vertically aligned carbon nanotube (VACNT arrays separated by a sub-micron vacuum gap. Doped graphene is found to improve photon tunneling in a broad hyperbolic frequency range, due to the interaction with graphene-graphene surface plasmon polaritons (SPP. In order to elucidate the SPP resonance between graphene on hyperbolic substrates, vacuum-suspended graphene sheets separated by similar gap distances are compared. Increasing the Fermi energy through doping shifts the spectral heat flux peak toward higher frequencies. Although the presence of graphene on VACNT does not offer huge near-field heat flux enhancement over uncovered VACNT, this study identifies conditions (i.e., gap distance and doping level that best utilize graphene to augment near-field radiation. Through the investigation of spatial Poynting vectors, heavily doped graphene is found to increase penetration depths in hyperbolic modes and the result is sensitive to the frequency regime. This study may have an impact on designing carbon-based vacuum thermophotovoltaics and thermal switches.

  3. Ralph A. Alpher, George Antonovich Gamow, and the Prediction of the Cosmic Microwave Background Radiation

    CERN Document Server

    Alpher, Victor S

    2014-01-01

    The first prediction of the existence of "relict radiation" or radiation remaining from the "Big Bang" was made in 1948. This derived from the seminal dissertation work of Ralph A. Alpher. He was a doctoral student of George A. Gamow and developed several critical advances in cosmology in late 1946, 1947, and 1948. Alpher developed the ideas of "hot" big bang cosmology to a high degree of physical precision, and was the first to present the idea that radiation, not matter, predominated the early universal adiabatic expansion first suggested by A. Friedmann in the early 1920s. Alpher and Herman predicted the residual relic black-body temperature in 1948 and 1949 at around 5 K. However, to this day, this prediction, and other seminal ideas in big bang cosmology, have often been attributed erroneously to the better-known George A. Gamow. This article reviews some of the more egregious and even farcical errors in the scholarly literature about Ralph A. Alpher and his place in the history of big bang cosmology. Tw...

  4. Near-field radiation between graphene-covered carbon nanotube arrays

    International Nuclear Information System (INIS)

    It has been shown that at small separation distances, thermal radiation between hyperbolic metamaterials is enhanced over blackbodies. This theoretical study considers near-field radiation when graphene is covered on the surfaces of two semi-infinite vertically aligned carbon nanotube (VACNT) arrays separated by a sub-micron vacuum gap. Doped graphene is found to improve photon tunneling in a broad hyperbolic frequency range, due to the interaction with graphene-graphene surface plasmon polaritons (SPP). In order to elucidate the SPP resonance between graphene on hyperbolic substrates, vacuum-suspended graphene sheets separated by similar gap distances are compared. Increasing the Fermi energy through doping shifts the spectral heat flux peak toward higher frequencies. Although the presence of graphene on VACNT does not offer huge near-field heat flux enhancement over uncovered VACNT, this study identifies conditions (i.e., gap distance and doping level) that best utilize graphene to augment near-field radiation. Through the investigation of spatial Poynting vectors, heavily doped graphene is found to increase penetration depths in hyperbolic modes and the result is sensitive to the frequency regime. This study may have an impact on designing carbon-based vacuum thermophotovoltaics and thermal switches

  5. Nuclear radiation in warfare

    International Nuclear Information System (INIS)

    The subject is covered in chapters, entitled: introduction; digest of nuclear weaponry (characteristics of nuclear weapons; effects of nuclear weapons other than ionizing radiation (fire-ball, fall-out, thermal radiation, blast wave, electromagnetic pulse); the nuclear arms race; war scenarios; biological effects of radiations on man (radiation doses; natural sources of radiation; acute effects of radiation; long-term somatic effects; genetic effects; factors affecting the biological response to radiation; internal exposure; synergistic effects; protection against radiation effects); radiations from nuclear explosions (initial radiation; fall-out; effects of fall-out on animal and plant life; contamination of water and food supplies by fall-out); radiation casualties in a nuclear war; effectiveness of civil defence; other warlike uses of radiation (attacks on civilian nuclear power installations; radiological warfare; terrorist activities); conclusion. (orig./HP)

  6. Synchrotron radiation

    International Nuclear Information System (INIS)

    Work at the Daresbury SRS has of necessity been interrupted this year (1991/92) due to the incorporation of Wiggler II. However, considerable beamtime was awarded before the shutdown and the major part of this appendix is concerned with the progress reports of the research undertaken then. The reports have been organised under the following broad headings: Molecular Science (19 papers), Surface and Materials Science (169 papers), Biological Science (85 papers), Instrumental and Technique Developments (13 papers) and Accelerator Physics (3 papers). It is hoped that in time the number of contributions on accelerator physics will grow to reflect the in-house activity on, for example, accelerator improvement and design. The research reports are preceded by the Annual Report of the Synchrotron Radiation Facilities Committee, which outlines the research highlights identified by that Committee (also included are details of the current membership of the SRFC and the chairmen of the Beamtime Allocation Panels). Following the reports are the specifications for the beamlines and stations. This year Section 3 contains 289 reports (nearly 100 more than last year) and the number of publications, generated by scientists and engineers who have used or are associated with Daresbury Laboratory facilities, has topped 500 for the first time. (author)

  7. Application and possible mechanisms of combining LLLT (low level laser therapy), infrared hyperthermia and ionizing radiation in the treatment of cancer

    Science.gov (United States)

    Abraham, Edward H.; Woo, Van H.; Harlin-Jones, Cheryl; Heselich, Anja; Frohns, Florian

    2014-02-01

    Benefit of concomitant infrared hyperthermia and low level laser therapy and ionizing radiation is evaluated in this study. The purpose/objectives: presentation with locally advanced bulky superficial tumors is clinically challenging. To enhance the efficacy of chemotherapy and IMRT (intensity-modulated radiation therapy) and/or electron beam therapy we have developed an inexpensive and clinically effective infrared hyperthermia approach that combines black-body infrared radiation with halogen spectrum radiation and discrete wave length infrared clinical lasers LLLT. The goal is to produce a composite spectrum extending from the far infrared to near infrared and portions of the visible spectrum with discrete penetrating wavelengths generated by the clinical infrared lasers with frequencies of 810 nm and/or 830 nm. The composite spectrum from these sources is applied before and after radiation therapy. We monitor the surface and in some cases deeper temperatures with thermal probes, but use an array of surface probes as the limiting safe thermal constraint in patient treatment while at the same time maximizing infrared entry to deeper tissue layers. Fever-grade infrared hyperthermia is produced in the first centimeters while non-thermal infrared effects act at deeper tissue layers. The combination of these effects with ionizing radiation leads to improved tumor control in many cancers.

  8. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Siegel, Robert

    2016-01-01

    Further expanding on the changes made to the fifth edition, Thermal Radiation Heat Transfer, 6th Edition continues to highlight the relevance of thermal radiative transfer and focus on concepts that develop the radiative transfer equation (RTE). The book explains the fundamentals of radiative transfer, introduces the energy and radiative transfer equations, covers a variety of approaches used to gauge radiative heat exchange between different surfaces and structures, and provides solution techniques for solving the RTE.

  9. Radiation controlling reversible window

    Energy Technology Data Exchange (ETDEWEB)

    Gell, H.A. Jr.

    1980-01-01

    A coated glass glazing system is presented including a transparent glass substrate having one surface coated with a radiation absorptive film which is overcoated with a radiation reflective film by a technique which renders the radiation reflective film radiation absorptive at the surface contracting the radiating absorptive film. The coated glass system is used as glazing for storm windows which are adapted to be reversible so that the radiation reflective surface may be exposed to the outside of the dwelling during the warm seasons to prevent excessive solar radiation from entering a dwelling and reversed during cold seasons to absorb solar radiation and utilize it to aid in keeping the dwelling interior warm.

  10. Detection of Terahertz Radiation

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a system for detecting terahertz radiation, a camera device, and a method for detecting terahertz radiation.......The present invention relates to a system for detecting terahertz radiation, a camera device, and a method for detecting terahertz radiation....

  11. Introduction to radiation biology

    International Nuclear Information System (INIS)

    This book is arranged in a logical sequence, starting from radiation physics and radiation chemistry, followed by molecular, subcellular and cellular effects and going on to the level of organism. Topics covered include applied radiobiology like modifiers of radiosensitivity, predictive assay, health physics, human genetics and radiopharmaceuticals. The topics covered are : 1. Radiation Physics, 2. Detection and Measurement of Radiation, 3. Radiation Chemistry, 4. DNA Damage and Repair, 5. Chromosomal Aberrations and Gene Mutations, 6. Cellular Radiobiology 7. Acute Radiation Effects, 8. Delayed Effects of Radiation, 9. Biological Basis of Radiotherapy, 10. Chemical Modifiers of Radiosensitivity, 11. Hyperthermia, 12. High LET Radiations in Cancer, Therapy, 13. Predictive Assays, 14. Radiation Effects on Embryos, 15. Human Radiation Genetics, 16. Radiolabelled Compounds in Biology and Medicine and 17. Radiological Health

  12. Radiation protection forum

    International Nuclear Information System (INIS)

    The National Director of the Nuclear Regulatory Authority and Radiation Protection of Uruguay in the first forum for radiation protection set out the following themes: activity of regulatory body, radiation safety, physical security, safeguards, legal framework, committed substantive program, use of radiation, risks and benefits, major sources of radiation, the national regulatory framework, national inventory of sources, inspections, licensing, import and export of sources control , radioactive transport, materials safety, agreements, information and teaching, radiological emergencies and prompt response.

  13. Wireless radiation sensor

    Energy Technology Data Exchange (ETDEWEB)

    Lamberti, Vincent E.; Howell, Jr, Layton N.; Mee, David K.; Kress, Reid L.

    2016-08-09

    Disclosed is a sensor for detecting radiation. The sensor includes a ferromagnetic metal and a radiation sensitive material coupled to the ferromagnetic metal. The radiation sensitive material is operable to change a tensile stress of the ferromagnetic metal upon exposure to radiation. The radiation is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the changes in the tensile stress.

  14. Radiation Safety Compliance.

    Science.gov (United States)

    Koth, Jana; Smith, Marcia Hess

    2016-05-01

    This article discusses radiation safety programs, including the members of the radiation safety team, their roles, and the challenges they face, with a focus on the radiation safety officer's duties. Agencies that regulate radiation safety also are described. The importance of minimizing patient dose, ensuring that dosimetry badges are worn correctly, and using therapeutic radioactive materials safely are addressed. Finally, radiologic technologists' role in using radiation safely is discussed, and the principles of time, distance, and shielding are reviewed. PMID:27146175

  15. Effect of Index of Refraction on Radiation Characteristics in a Heated Absorbing, Emitting, and Scattering Layer

    Science.gov (United States)

    Siegel, R.; Spuckler, C. M.

    1992-01-01

    The index of refraction can considerably influence the temperature distribution and radiative heat flow in semitransparent materials such as some ceramics. For external radiant heating, the refractive index influences the amount of energy transmitted into the interior of the material. Emission within a material depends on the square of its refractive index, and hence this emission can be many times that for a biackbody radiating into a vacuum. Since radiation exiting through an interface into a vacuum cannot exceed that of a blackbody, there is extensive reflection at the internal surface of an interface, mostly by total internal reflection. This redistributes energy within the layer and tends to make its temperature distribution more uniform. The purpose of the present analysis is to show that, for radiative equilibrium in a gray layer with diffuse interfaces, the temperature distribution and radiative heat flux for any index of refraction can be obtained very simply from the results for an index of refraction of unity. For the situation studied here, the layer is subjected to external radiative heating incident on each of its surfaces. The material emits, absorbs, and isotropically scatters radiation. For simplicity the index of refraction is unity in the medium surrounding the layer. The surfaces of the layer are assumed diffuse. This is probably a reasonable approximation for a ceramic layer that has not been polished. When transmitted radiation or radiation emitted from the interior reaches the inner surface of an interface, the radiation is diffused and some of it thereby placed into angular directions for which there is total internal reflection. This provides a trapping effect for retaining energy within the layer and tends to equalize its temperature distribution. An analysis of temperature distributions in absorbing-emitting layers, including index of refraction effects, was developed by Gardon (1958) to predict cooling and heat treating of glass plates

  16. Cosmic background radiation in the vicinity of a Schwarzschild black hole: No classic firewall

    Science.gov (United States)

    Wielgus, M.; Ellis, G. F. R.; Vincent, F. H.; Abramowicz, M. A.

    2014-12-01

    The cosmic blackbody background radiation pervades the entire Universe, and so falls into every astrophysical black hole. The blueshift of the infalling photons, measured by a static observer, is infinite at the event horizon. This raises a question as to whether a "firewall" of high energy density may form just outside the horizon, or whether the effect can be attributed exclusively to a singular behavior of the static observer's frame at the horizon. In principle, the presence of such a firewall may alter the motion of the infalling matter, influence the black hole evolution, or even invalidate the vacuum Einstein field equation solution as a realistic approximation for black holes. In this paper we show by means of analytic calculations that all these effects indeed exist, but their magnitude is typically negligibly small, even though the matter stress tensor is divergent in the static frame at r =2 M . That is not surprising because of the divergent relation of that frame to a freely falling frame as r →2 M ; however, it represents a kind of classical analogue for the black hole complementarity principle that has been proposed for quantum effects near a black hole. What is perhaps more surprising is the divergence of the radiation stress tensor for massive particles moving on circular geodesic orbits for values of r approaching r =3 M . However such orbits will not occur for infalling matter in realistic accretion discs.

  17. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiotherapy. Current research topics include: oncogenic transformation assays, mutation studies involving interactions between radiation and environmental contaminants, isolation, characterization and sequencing of a human repair gene, characterization of a dominant transforming gene found in C3H 10T1/2 cells, characterize ab initio the interaction of DNA and radiation, refine estimates of the radiation quality factor Q, a new mechanistic model of oncogenesis showing the role of long-term low dose medium LET radiation, and time dependent modeling of radiation induced chromosome damage and subsequent repair or misrepair

  18. Fundamentals of radiation technologies

    International Nuclear Information System (INIS)

    The proceedings contain papers dealing with current trends in radiation technologies, the basic concepts of radiation technologies, the interaction of ionizing radiation with matter, and the foundations of radiation chemistry. Also described are the technical and economic principles of design and the use of radionuclide radiation sources and electron accelerators. The problems are discussed of radiosterilization, the radiation processing of polymers and their degradation, and the radiopreservation of cultural and museum objects. Also dealt with is the irradiation of foods and the impact of radiation technologies on the environment including radiation chemistry problems of nuclear power plants. The basic principles are explained of work safety in handling sources of ionizing radiation. (J.C.)

  19. Argentine radiation protection society

    International Nuclear Information System (INIS)

    The Argentine Radiation Protection Society (SAR) is a non profit society, member of IRPA. It was originally launched in 1987 and a formal constitution was adopted in 1983. Presently, SAR has 220 active members, professionals and technicians dedicated to a variety of disciplines related to different radiation protection aspects: medicine, industry, research and teaching. The basic SAR objectives are: to promote research and knowledge exchange on radiation protection topics and related disciplines; to promote the comprehension of radiation protection criteria with regard to existence and handling of radioactive and fissile materials and any other radiation sources; to foster the conception of radiation protection as a professional discipline and to contribute to its permanent improvement; to promote the diffusion of the information related to all radiation protection and nuclear safety aspects, and radiation protection standards and recommendations, not only within the scientific, technical and academic areas, but also to general public

  20. Radiation processing in Japan

    International Nuclear Information System (INIS)

    Economic scale of radiation application in the field of industry, agriculture and medicine in Japan in 1997 was investigated to compare its economic impacts with that of nuclear energy industry. Total production value of radiation application accounted for 54% of nuclear industry including nuclear energy industry and radiation applications in three fields above. Industrial radiation applications were further divided into five groups, namely nondestructive test, RI instruments, radiation facilities, radiation processing and ion beam processing. More than 70% of the total production value was brought about by ion beam processing for use with IC and semiconductors. Future economic prospect of radiation processing of polymers, for example cross-linking, EB curing, graft polymerization and degradation, is reviewed. Particular attention was paid to radiation vulcanization of natural rubber latex and also to degradation of natural polymers. (S. Ohno)

  1. Space radiation effects

    International Nuclear Information System (INIS)

    The authors briefly discusses the radiation environment in near-earth space and it's influences on material, and electronic devices using in space airship, also, the research developments in space radiation effects are introduced

  2. Radiation in genetic engineering

    International Nuclear Information System (INIS)

    Radiation as used in genetic engineering involves producing changes in the hereditary units of existing plants and animals by the use of radiation. The desired results of such irradiation is to increase the quality and/or quantity of such plants or animals. The mode of radiation interaction with biological samples or cells is described by the 'Target theory'. This theory considers the radiosensitive portion of the medium as target to be hit by radiation particles. Cellular effect of radiation can be divided into two types, i.e. effect on cell division and effects on cell metabolism. As a result of radiation induced changes to DNA and proteins, visible damage to chromosome can sometimes be seen. Every radiation, even a single beta particle may be of great importance and consequence if it hits a vital component in a particular manner. Hence even normal background radiation induces mutation and may help in the natural evolution process. (A.S.)

  3. External Radiation Therapy

    Medline Plus

    Full Text Available ... frequently used is radiation therapy. Gunnar Zagars, M.D.: There are different forms of radiation for prostate ... typical treatment takes seven weeks. Gunnar Zagars, M.D.: A patient comes in every day, Monday to ...

  4. Radiation processing in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Economic scale of radiation application in the field of industry, agriculture and medicine in Japan in 1997 was investigated to compare its economic impacts with that of nuclear energy industry. Total production value of radiation application accounted for 54% of nuclear industry including nuclear energy industry and radiation applications in three fields above. Industrial radiation applications were further divided into five groups, namely nondestructive test, RI instruments, radiation facilities, radiation processing and ion beam processing. More than 70% of the total production value was brought about by ion beam processing for use with IC and semiconductors. Future economic prospect of radiation processing of polymers, for example cross-linking, EB curing, graft polymerization and degradation, is reviewed. Particular attention was paid to radiation vulcanization of natural rubber latex and also to degradation of natural polymers. (S. Ohno)

  5. Working with radiation

    International Nuclear Information System (INIS)

    This simple booklet is written primarily to supply information about radiation, its potential dangers and radiation protection, to those working for, or considering taking up employment with, British Nuclear Fuels plc. (U.K.)

  6. Radiation Protection Handbook

    Science.gov (United States)

    1972-01-01

    A handbook which sets forth the Kennedy Space Center radiation protection policy is presented. The book also covers administrative direction and guidance on organizational and procedural requirements of the program. Only ionizing radiation is covered.

  7. External Radiation Therapy

    Medline Plus

    Full Text Available ... the treatment that is frequently used is radiation therapy. Gunnar Zagars, M.D.: There are different forms of radiation for prostate cancer. They really boil down to two different types. ...

  8. Radiation protection standards

    International Nuclear Information System (INIS)

    The present paper deals with: Objectives and basic concepts of radiation protection, basic radiobiological considerations, the ICRP system of dose limitation and with operational radiation protection (limits, reference levels, occupational exposure). (RW)

  9. Environmental Radiation Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Environmental Radiation Data (ERD) is an electronic and print journal compiled and distributed quarterly by the Office of Radiation and Indoor Air's National Air...

  10. Principles of radiation detection

    International Nuclear Information System (INIS)

    After a short description of the ionizing radiations and their interactions with matter, the properties and functions of radiation detector systems in general and of the scintillation and semiconductor detectors in particular are presented. Figs and tabs

  11. External radiation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  12. Polymer radiation chemistry

    International Nuclear Information System (INIS)

    This article reviews some of the work carried out in the Polymer and Radiation Group at the University of Queensland over the past ten years. The objective of the work has been to investigate the relationships between polymer structure and sensitivity towards high energy radiation, including 60Co gamma radiation, electron beams and UV radiation. A range of synthetic polymers containing carboxyl groups, acrylate groups, sulfone groups, amide linkages and aromatic residues have been investigated. (author). 18 refs, 2 figs, 4 tabs

  13. Radiation effects in semiconductors

    CERN Document Server

    2011-01-01

    There is a need to understand and combat potential radiation damage problems in semiconductor devices and circuits. Written by international experts, this book explains the effects of radiation on semiconductor devices, radiation detectors, and electronic devices and components. These contributors explore emerging applications, detector technologies, circuit design techniques, new materials, and innovative system approaches. The text focuses on how the technology is being used rather than the mathematical foundations behind it. It covers CMOS radiation-tolerant circuit implementations, CMOS pr

  14. Radiation protection at CERN

    OpenAIRE

    Forkel-Wirth, Doris; Roesler, Stefan; Silari, Marco; Streit-Bianchi, Marilena; Theis, Christian; Vincke, Heinz; Vincke, Helmut

    2013-01-01

    This paper gives a brief overview of the general principles of radiation protection legislation; explains radiological quantities and units, including some basic facts about radioactivity and the biological effects of radiation; and gives an overview of the classification of radiological areas at CERN, radiation fields at high-energy accelerators, and the radiation monitoring system used at CERN. A short section addresses the ALARA approach used at CERN.

  15. Synchrotron radiation facilities

    CERN Multimedia

    1972-01-01

    Particularly in the past few years, interest in using the synchrotron radiation emanating from high energy, circular electron machines has grown considerably. In our February issue we included an article on the synchrotron radiation facility at Frascati. This month we are spreading the net wider — saying something about the properties of the radiation, listing the centres where synchrotron radiation facilities exist, adding a brief description of three of them and mentioning areas of physics in which the facilities are used.

  16. Application of ionizing radiations

    International Nuclear Information System (INIS)

    The main subject of the application of Ionizing Radiations Program is to disseminate and consolidate techniques leading to the use of the radiation technology and radioisotopes application in Industry, Human Health, Agriculture and Environmental Preservation. This Program is divided into four subprograms: 1) Food and Agricultural Products Irradiation; 2) Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; Radioactive Facilities and Equipment for Nuclear Techniques Applications

  17. Hybrid radiator cooling system

    Energy Technology Data Exchange (ETDEWEB)

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  18. (Mis)Understanding Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, Stephen Bruce [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-10

    This set of slides discusses radiation and fears concerning it at a non-technical level. Included are some misconceptions and practical consequences resulting from these. The concept of radiation hormesis is explained. The author concludes that a number of significant societal benefits are being foregone because of overly cautious concerns about low-level radiation.

  19. Biological implications of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bond, V.P.

    1977-01-01

    Some topics discussed are as follows: effects of diagnostic and therapeutic radiation on dividing cells, DNA, and blood cells; radiation sickness in relation to dose; early and late effects of radiation; effects of low dose irradiation; dose-effect curves; radioinduction of tumors in animals; and incidence of cancer in children following in utero exposure to diagnostic x rays. (HLW)

  20. Quark radiation from LEP

    International Nuclear Information System (INIS)

    Like any other electrically charged particles, quarks should give out electromagnetic radiation (photons) when they vibrate. One of the physics results from CERN's LEP collider is the first clear observation of this quark radiation from electron-positron collisions. At lower energies this radiation could only be inferred

  1. Radiation bioengineering; Bioinzynieria radiacyjna

    Energy Technology Data Exchange (ETDEWEB)

    Rosiak, J.M. [Politechnika Lodzka, Lodz (Poland). Inst. Techniki Radiacynej

    1997-10-01

    Radiation processing for modification of different properties of materials being designed for medical use have been described. Especially the polymers as very often used for medical equipment production have been modified by radiation. The different medical applications of biomaterials based on radiation modified polymers have been presented. 13 refs.

  2. Applications of ionizing radiations

    International Nuclear Information System (INIS)

    The R and D activities of the application of Ionizing Radiations Program is comprised to four subprograms: Food and Agricultural Productions Irradiation; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for Nuclear Techniques Applications

  3. Application of ionizing radiation

    International Nuclear Information System (INIS)

    Fundamental studies by the Nuclear Research Institute concerning the use of ionizing radiations are reported. The ROZA irradiation plant is used for sterilization in medicine and for historic objects preservation. Ionizing radiation is used in the radiation treatment of cables and drinking water. Radiopharmaceuticals are developed. The Institute is an all-state centre for research and development of semiconductor detectors. (M.S.)

  4. Ultraviolet radiation and immunosuppression.

    LENUS (Irish Health Repository)

    Murphy, G M

    2009-11-01

    Ultraviolet (UV) radiation is a complete carcinogen. The effects of UV radiation are mediated via direct damage to cellular DNA in the skin and suppression of image surveillance mechanisms. In the context of organ transplantation, addiction of drugs which suppress the immune system add greatly to the carcinogenicity of UV radiation. This review considers the mechanisms of such effects.

  5. Topics in radiation dosimetry radiation dosimetry

    CERN Document Server

    1972-01-01

    Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

  6. Mental models of radiation

    International Nuclear Information System (INIS)

    Laymen and experts participated in interviews designed to reveal their 'mental models' of the processes potentially causing the miscommunications between experts and the public. We analyzed their responses in terms of an 'expert model' circumscribing scientifically relevant information. From results, there are gaps even between experts. Experts on internal exposure focused mainly on artificial radiation and high level of radiation. Experts on radiation biology focused on medical radiation, level of risk, environmental radiation, and hot springs. Experts on dosimetric performance focused on atomic power generation and needs of radiological protection. It means that even experts, they have interests only on their own specialized field. (author)

  7. Monitoring of radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service.

  8. Radiation protection and instrumentation

    Science.gov (United States)

    Bailey, J. V.

    1975-01-01

    Radiation was found not to be an operational problem during the Apollo program. Doses received by the crewmen of Apollo missions 7 through 17 were small because no major solar-particle events occurred during those missions. One small event was detected by a radiation sensor outside the Apollo 12 spacecraft, but no increase in radiation dose to the crewmen inside the spacecraft was detected. Radiation protection for the Apollo program was focused on both the peculiarities of the natural space radiation environment and the increased prevalence of manmade radiation sources on the ground and onboard the spacecraft. Radiation-exposure risks to crewmen were assessed and balanced against mission gain to determine mission constraints. Operational radiation evaluation required specially designed radiation detection systems onboard the spacecraft in addition to the use of satellite data, solar observatory support, and other liaison. Control and management of radioactive sources and radiation-generating equipment was important in minimizing radiation exposure of ground-support personnel, researchers, and the Apollo flight and backup crewmen.

  9. Biological improvement of radiation resistance

    Energy Technology Data Exchange (ETDEWEB)

    Chun, K. J.; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J

    2000-08-01

    To investigate the mechanisms of gene action related to the radiation resistance in microorganisms could be essentially helpful for the development of radiation protectants and hormeric effects of low dose radiation. This book described isolation of radiation-resistant microorganisms, induction of radiation-resistant and functionally improved mutants by gamma-ray radiation, cloning and analysis of the radiation resistance related genes and analysis of the expressed proteins of the radiation resistant related genes.

  10. Biological improvement of radiation resistance

    International Nuclear Information System (INIS)

    To investigate the mechanisms of gene action related to the radiation resistance in microorganisms could be essentially helpful for the development of radiation protectants and hormeric effects of low dose radiation. This book described isolation of radiation-resistant microorganisms, induction of radiation-resistant and functionally improved mutants by gamma-ray radiation, cloning and analysis of the radiation resistance related genes and analysis of the expressed proteins of the radiation resistant related genes

  11. Radiation safety audit

    International Nuclear Information System (INIS)

    Audit has been seen as one of the effective methods to ensure harmonization in radiation protection. A radiation safety audit is a formal safety performance examination of existing or future work activities by an independent team. Regular audit will assist the management in its mission to maintain the facilities environment that is inherently safe for its employees. The audits review the adequacy of facilities for the type of use, training, and competency of workers, supervision by authorized users, availability of survey instruments, security of radioactive materials, minimization of personnel exposure to radiation, safety equipment, and the required record keeping. All approved areas of use are included in these periodic audits. Any deficiency found in the audit shall be corrected as soon as possible after they are reported. Radiation safety audit is a proactive approach to improve radiation safety practices and identify and prevent any potential radiation accident. It is an excellent tool to identify potential problem to radiation users and to assure that safety measures to eliminate or reduce the problems are fully considered. Radiation safety audit will help to develop safety culture of the facility. It is intended to be the cornerstone of a safety program designed to aid the facility, staff and management in maintaining a safe environment in which activities are carried out. The initiative of this work is to evaluate the need of having a proper audit as one of the mechanism to manage the safety using ionizing radiation. This study is focused on the need of having a proper radiation safety audit to identify deviations and deficiencies of radiation protection programmes. It will be based on studies conducted on several institutes/radiation facilities in Malaysia in 2006. Steps will then be formulated towards strengthening radiation safety through proper audit. This will result in a better working situation and confidence in the radiation protection community

  12. Radiation protection - thirty years after

    International Nuclear Information System (INIS)

    In this paper is discussed some questions in the field of Radiation Protection as like: historical prologue of radiations discovery and it's systematics; radiation and radiation protection; ALARA principle and 'de minimis' approach; radiation risks and dose limits and radiation and chemicals a risk comparison (author)

  13. Radiation: boon or bane?

    International Nuclear Information System (INIS)

    Mankind has been exposed to radiation ever since the very first stage of its evolutionary development. Radiation is one of the greatest discoveries of mankind. Radiation has turned out to be a razor-sharp double-edged sword. In earlier days, it worried no one, because nobody knew about it. The correct application of radiation, be it in any field, have made lives better. Radiation in reality, a boon as well as a curse. Radiation is important but it is time we have to decide where to draw the line. For example, the match stick by itself is just a harmless object. One can use it to light a lamp or light a fire for cooking. In the hands of a mother lighting the lamp or the cooking fire, it becomes beneficial. The same match stick in the hands of a small careless child could prove to be fatal. The increased use of radiation has created fear in the minds of people regarding its possible adverse effects on living systems. Radiation is highly dangerous if not used with caution. This fear is heightened by nuclear fallouts, nuclear accidents and of high levels of natural background radiation in geographical areas in a number of countries. Terrorists may take advantage of technology and may produce nuclear weapons, which is a great risk for entire world. There are numerous reports about increasing health hazards like headache, sleep disorders, lack of concentration, infertility, memory loss, cardiovascular problems, cancer etc. which arises due to over exposure of radiation. Apart from human race, radiation affects other animals and overall environment. Although it has adverse effects on living beings but it cannot be denied that today radiation is a common and valuable tool in medicine, agriculture, research and industry. Radiation has contributed to significant improvements in fields of communications technology and energy. Radiation has proved to be an excellent source in terms of amount of energy production with generation of minimal waste. Even though it produces small

  14. Canada: Living with radiation

    International Nuclear Information System (INIS)

    Canadians are exposed daily to a variety of naturally occurring radiation. Heat and light from the sun, are familiar examples. Radium and uranium are naturally occurring materials which have been found to emit radiation and so have been called radioactive. There are also various types of artificially produced forms of radiation that are employed routinely in modern living, such as radio and television waves and microwaves. X-rays, another common type of radiation, are widely used in medicine as are some man-made radioactive substances. These emit radiation just like naturally occurring radioactive materials. Surveys have shown that many people have a poor understanding of the risks associated with the activities of modern living. Exposure to ionizing radiation from radioactive materials is also considered by many persons to have a high risk, This booklet attempts to inform the readers about ionizing radiation, its uses and the risks associated with it, and to put these risks in perspective with the risks of other activities and practices. A range of topics from medical uses of radiation to emergency planning, from biological effects of radiation to nuclear power, each topic is explained to relate radiation to our everyday lives. 44 figs

  15. Radiation processing of polyethylene

    Science.gov (United States)

    Barlow, A.; Biggs, J. W.; Meeks, L. A.

    This paper covers two areas (a) the use of high energy radiation for the synthesis and improvement of polymer properties and (b) the formulation of radiation curable compounds for automotive/appliance wire applications and high voltage insulation. The first part discusses the use of gamma radiation for the bulk polymerization of ethylene and the properties of the polymer produced. The use of low dose radiation to increase polymer molecular weight and modify polydispersity is also described together with its projected operational cost. An update is provided of the cost savings that can be realized when using radiation crosslinked heavy duty film, which expands its applications, compared with noncrosslinked materials. The second section of the paper considers the advantages and disadvantages of radiation vs. peroxide curing of wire and cable compounds. The formulation of a radiation curable, automotive/appliance wire compound is discussed together with the interactions between the various ingredients; i.e., base resin, antioxidants, flame retardant filler, coupling agents, processing aids and radiation to achieve the desired product. In addition, the general property requirements of a radiation curable polyethylene for high voltage insulation are discussed; these include crosslinking efficiency, thermal stability, wet tree resistance and satisfactory dielectric properties. Preliminary data generated in the development of a 230KV radiation crosslinked polyethylene insulation are included.

  16. [Multispectral Radiation Algorithm Based on Emissivity Model Constraints for True Temperature Measurement].

    Science.gov (United States)

    Liang, Mei; Sun, Xiao-gang; Luan, Mei-sheng

    2015-10-01

    Temperature measurement is one of the important factors for ensuring product quality, reducing production cost and ensuring experiment safety in industrial manufacture and scientific experiment. Radiation thermometry is the main method for non-contact temperature measurement. The second measurement (SM) method is one of the common methods in the multispectral radiation thermometry. However, the SM method cannot be applied to on-line data processing. To solve the problems, a rapid inversion method for multispectral radiation true temperature measurement is proposed and constraint conditions of emissivity model are introduced based on the multispectral brightness temperature model. For non-blackbody, it can be drawn that emissivity is an increasing function in the interval if the brightness temperature is an increasing function or a constant function in a range and emissivity satisfies an inequality of emissivity and wavelength in that interval if the brightness temperature is a decreasing function in a range, according to the relationship of brightness temperatures at different wavelengths. The construction of emissivity assumption values is reduced from multiclass to one class and avoiding the unnecessary emissivity construction with emissivity model constraint conditions on the basis of brightness temperature information. Simulation experiments and comparisons for two different temperature points are carried out based on five measured targets with five representative variation trends of real emissivity. decreasing monotonically, increasing monotonically, first decreasing with wavelength and then increasing, first increasing and then decreasing and fluctuating with wavelength randomly. The simulation results show that compared with the SM method, for the same target under the same initial temperature and emissivity search range, the processing speed of the proposed algorithm is increased by 19.16%-43.45% with the same precision and the same calculation results.

  17. A measurement of the low frequency spectrum of the cosmic microwave background radiation

    International Nuclear Information System (INIS)

    As part of a larger effort to measure the spectrum of the Cosmic Background Radiation (CBR) at low frequencies, the intensity of the CBR has been measured at a frequency of 1.410 GHz. The measurement was made by comparing the power received from the sky with the power received from a specially designed cooled calibration target with known properties. Sources of radiation other than the CBR were then identified and subtracted to calculate the antenna temperature of the CBR at 1.410 GHz. The instrument used to measure the CBR was a total-power microwave radiometer with a 25 MHz bandwidth centered at 1.410 GHz. The radiometer had a noise temperature of 80 K, and sufficient data were taken that radiometer noise did not contribute significantly to the total measurement error. The sources of error were predominantly systematic in nature, and the largest error was due to uncertainty in the reflection characteristics of the cold-load calibrator. Identification and subtraction of signals from the Galaxy (0.7 K) and the Earth's atmosphere (0.8 K) were also significant parts of the data reduction and error analysis. The brightness temperature of the Cosmic Background Radiation at 1.410 GHz is 222. +- 0.55 Kelvin. The spectrum of the CBR, as determined by this measurement and other published results, is consistent with a blackbody spectrum of temperature 2.741 +- 0.016. Constraints on the amount by which the CBR spectrum deviates from Planck spectrum are used to place limits on energy releases early in the history of the universe. 55 refs., 25 figs., 8 tabs

  18. [Multispectral Radiation Algorithm Based on Emissivity Model Constraints for True Temperature Measurement].

    Science.gov (United States)

    Liang, Mei; Sun, Xiao-gang; Luan, Mei-sheng

    2015-10-01

    Temperature measurement is one of the important factors for ensuring product quality, reducing production cost and ensuring experiment safety in industrial manufacture and scientific experiment. Radiation thermometry is the main method for non-contact temperature measurement. The second measurement (SM) method is one of the common methods in the multispectral radiation thermometry. However, the SM method cannot be applied to on-line data processing. To solve the problems, a rapid inversion method for multispectral radiation true temperature measurement is proposed and constraint conditions of emissivity model are introduced based on the multispectral brightness temperature model. For non-blackbody, it can be drawn that emissivity is an increasing function in the interval if the brightness temperature is an increasing function or a constant function in a range and emissivity satisfies an inequality of emissivity and wavelength in that interval if the brightness temperature is a decreasing function in a range, according to the relationship of brightness temperatures at different wavelengths. The construction of emissivity assumption values is reduced from multiclass to one class and avoiding the unnecessary emissivity construction with emissivity model constraint conditions on the basis of brightness temperature information. Simulation experiments and comparisons for two different temperature points are carried out based on five measured targets with five representative variation trends of real emissivity. decreasing monotonically, increasing monotonically, first decreasing with wavelength and then increasing, first increasing and then decreasing and fluctuating with wavelength randomly. The simulation results show that compared with the SM method, for the same target under the same initial temperature and emissivity search range, the processing speed of the proposed algorithm is increased by 19.16%-43.45% with the same precision and the same calculation results

  19. Radiation physics, biophysics, and radiation biology

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  20. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood ''biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons

  1. RADIATION WAVE DETECTION

    Science.gov (United States)

    Wouters, L.F.

    1960-08-30

    Radiation waves can be detected by simultaneously measuring radiation- wave intensities at a plurality of space-distributed points and producing therefrom a plot of the wave intensity as a function of time. To this end. a detector system is provided which includes a plurality of nuclear radiation intensity detectors spaced at equal radial increments of distance from a source of nuclear radiation. Means are provided to simultaneously sensitize the detectors at the instant a wave of radiation traverses their positions. the detectors producing electrical pulses indicative of wave intensity. The system further includes means for delaying the pulses from the detectors by amounts proportional to the distance of the detectors from the source to provide an indication of radiation-wave intensity as a function of time.

  2. Radiation Protection. Chapter 24

    International Nuclear Information System (INIS)

    Chapter 21, in describing basic radiation biology and radiation effects, demonstrates the need to have a system of radiation protection that allows the many beneficial uses of radiation to be realized while ensuring detrimental radiation effects are either prevented or minimized. This can be achieved with the twin objectives of preventing the occurrence of deterministic effects and of limiting the probability of stochastic effects to a level that is considered acceptable. In a radiology facility, consideration needs to be given to the patient, the staff involved in performing the radiological procedures, members of the public and other staff that may be in the radiology facility, carers and comforters of patients undergoing procedures, and persons who may be undergoing a radiological procedure as part of a biomedical research project. This chapter discusses how the objectives given above are fulfilled through a system of radiation protection and how such a system should be applied practically in a radiology facility

  3. Difficult wounds: radiation wounds

    International Nuclear Information System (INIS)

    In an era of modern radiotherapy, problems associated with the indiscriminate treatment of benign disease have largely disappeared. Skin sparing effects of super voltage radiation equipment make the problems previously seen with orthovoltage equipment less frequent. Vigilance on the part of the workers in the field, in general, protects from the disasters that befell Thomas Edison's laboratory assistant. Despite these modern advances, the reconstructive surgeon often faces problems of managing acute local radiation injury from accident following planned therapeutic radiation or the ulcerations and breakdowns seen months or years after radiation therapy. The single most serious hazard to surgery in radiated tissue is the lodgment of bacteria in this tissue rendered avascular by the radiation and secondary necrosis from the infection itself. The principles of management are no different from those used for other chronic granulating wounds: local wound care, appropriate topical antibacterial therapy, systemic antibiotics during the perioperative period and, most importantly, adequate soft tissue coverage

  4. Health of radiation workers

    International Nuclear Information System (INIS)

    Radiation workers are healthier than the average person in the general population and appear to be as healthy as workers in other ΣsafeΣ industries. It is, however, assumed that there is no safe dose of radiation and that any exposure to radiation will cause a small increase in the incidence of cancer, this increase being directly proportional to the total radiation dose. On the basis of the risk estimates given by ICRP, radiation exposures up to 1 rem per year for 47 years are predicted to cause fewer work-related deaths than expected for the average worker in Canadian industry. Radiation exposures of 5 rem per year from age 18 to 65 would result in predicted risk which is about four times higher than that for most workers in Canada and might increase the chances of death before age 75 to nearly the same level as for the average member of the general public. (auth)

  5. Environmental radiation data, 9

    International Nuclear Information System (INIS)

    The Environmental Physics Laboratory has conducted a large number of background radiation surveys in these years, aiming at the analysis of characteristics and behaviour of environmental radiation, the development of measurement techniques and instruments of environmental radiation, and the evaluation of environmental radiation dose. As the environmental radiation data obtained by these surveys are useful for broad purposes as actual survey data, it is desirable to arrange these data systematically and to open them to the other scientist. For that, it is necessary to make the recording media and the FORMAT of these data available for usual computers. In the light of this circumstance, these data were rearranged and recompiled systematically to meet the demand. This report mentions about the data obtained by the background radiation surveys in and around Tokyo performed during 1991 - 1993 using portable instruments, as well as the information necessary for the data handling. (author)

  6. User's manual for CNVUFAC, the general dynamics heat-transfer radiation view factor program

    Energy Technology Data Exchange (ETDEWEB)

    Wong, R. L.

    1976-06-25

    CNVUFAC, the General Dynamics heat-transfer radiation veiw factor program, has been adapted for use on the LLL CDC 7600 computer system. The input and output have been modified, and a node incrementing logic was included to make the code compatible with the TRUMP thermal analyzer and related codes. The program performs the multiple integration necessary to evaluate the geometric black-body radiaton node to node view factors. Card image output that contains node number and view factor information is generated for input into the related program GRAY. Program GRAY is then used to include the effects of gray-body emissivities and multiple reflections, generating the effective gray-body view factors usable in TRUMP. CNVUFAC uses an elemental area summation scheme to evaluate the multiple integrals. The program permits shadowing and self-shadowing. The basic configuration shapes that can be considered are cylinders, cones, spheres, ellipsoids, flat plates, disks, toroids, and polynomials of revolution. Portions of these shapes can also be considered.

  7. RHOBOT: Radiation hardened robotics

    International Nuclear Information System (INIS)

    A survey of robotic applications in radioactive environments has been conducted, and analysis of robotic system components and their response to the varying types and strengths of radiation has been completed. Two specific robotic systems for accident recovery and nuclear fuel movement have been analyzed in detail for radiation hardness. Finally, a general design approach for radiation-hardened robotics systems has been developed and is presented. This report completes this project which was funded under the Laboratory Directed Research and Development program

  8. Registration of radiation doses

    International Nuclear Information System (INIS)

    In Finland the Radiation and Nuclear Safety Authority (STUK) is maintaining the register (called Dose Register) of the radiation exposure of occupationally exposed workers in order to ensure compliance with the principles of optimisation and individual protection. The guide contains a description of the Dose Register and specifies the responsibilities of the party running a radiation practice to report the relevant information to the Dose Register

  9. Ionizing Radiation and Life

    OpenAIRE

    Dartnell, L. R.

    2011-01-01

    Ionizing radiation is a ubiquitous feature of the Cosmos, from exogenous cosmic rays (CR) to the intrinsic mineral radioactivity of a habitable world, and its influences on the emergence and persistence of life are wide-ranging and profound. Much attention has already been focused on the deleterious effects of ionizing radiation on organisms and the complex molecules of life, but ionizing radiation also performs many crucial functions in the generation of habitable planetary environments and ...

  10. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  11. RHOBOT: Radiation hardened robotics

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, P.C.; Posey, L.D. [Sandia National Labs., Albuquerque, NM (United States)

    1997-10-01

    A survey of robotic applications in radioactive environments has been conducted, and analysis of robotic system components and their response to the varying types and strengths of radiation has been completed. Two specific robotic systems for accident recovery and nuclear fuel movement have been analyzed in detail for radiation hardness. Finally, a general design approach for radiation-hardened robotics systems has been developed and is presented. This report completes this project which was funded under the Laboratory Directed Research and Development program.

  12. Heterogeneous radiation catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Cabicar, J.; Kudlacek, R.; Motl, A.; Mucka, V.; Pospisil, M. (Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Jaderna a Fysikalne Inzenyrska)

    1982-01-01

    Results of the investigation of some radiation catalysis problems are reviewed. Main attention is paid to the radiation effect on the catalytic activity of various catalysts in the decomposition of hydrogen peroxide and in the hydrogenation of maleic acid. The results presented are obtained in the study of the kinetics of reduction of several pre-irradiated metal oxides and of the radiation effect on catalysts used in some catalytic reactions important for industry.

  13. Canada's radiation scandal?

    International Nuclear Information System (INIS)

    In July 1990, Greenpeace distributed a 16-page treatise entitled 'Canada's Radiation Scandal' to a wide audience. The bottom line of the Greenpeace critique was that 'Canada's radiation limits are among the worst in the developed world'. This is a commentary on the Greenpeace pamphlet from the Atomic Energy Control Board (AECB), the body that sets and enforces radiation standards covering the use of nuclear energy in Canadian industry, science and medicine

  14. Solar radiation conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Kittl, E.

    1975-12-30

    A system for converting solar radiation into useful electrical energy is provided. The system includes a silicon cell and solar radiation conversion means integral with or spaced from the silicon cell. The solar radiation conversion means is characterized by a band-emission spectrum that provides a good spectral match with the spectral response of a silicon cell. 6 Claims, 3 Drawing Figures (Official Gazette)

  15. Chemical effects of radiation

    International Nuclear Information System (INIS)

    Ionizing radiations initiate chemical changes in materials because of the high energy of their quanta. In water, highly reactive free radicals are produced which can initiate secondary changes of solutes, and in chemical of biological molecules in contact with the water. Free radicals can also be directly produced in irradiated medical products. Their fate can be identified and the molecular basis of radiation inactivation clarified. Methods have now been developed to protect and minimise such radiation damage. (author)

  16. Optimization of radiation protection

    International Nuclear Information System (INIS)

    The Symposium presentations were divided into three sessions devoted to the following topics: the role of optimization of radiation protection (10 papers), application of the principle of optimization of radiation protection (26 papers), methods and techniques in the optimization of radiation protection (7 papers). An additional session was devoted to the presentation of a summary statement and to an extended discussion by a panel of senior experts on the question of whether optimization (ALARA) is meeting its objective

  17. Solar radiation models - review

    OpenAIRE

    M. Jamil Ahmad, G.N. Tiwari

    2010-01-01

    In the design and study of solar energy, information on solar radiation and its components at a given location is very essential. Solar radiation data are required by solar engineers, architects, agriculturists and hydrologists for many applications such as solar heating, cooking, drying and interior illumination of buildings. For this purpose, in the past, several empirical correlations have been developed in order to estimate the solar radiation around the world. The main objective of this ...

  18. Low-level radiation

    International Nuclear Information System (INIS)

    It is known that the normal incidence of cancer in human populations is increased by exposure to moderately high doses of ionizing radiation. At background radiation levels or at radiation levels which are 100 times greater, the potential health risks are considered to be directly proportional to the total accumulated dose of radiation. Some of the uncertainties associated with this assumption and with the accepted risk estimates have been critically reviewed in this document. The general scientific consensus at present suggests that the accepted risk estimates may exaggerate the actual risk of low levels of sparsely ionizing radiations (beta-, gamma- or X-rays) somewhat but are unlikely to overestimate the actual risks of densely ionizing radiations (fast neutrons, alpha-particles). At the maximum permissible levels of exposure for radiation workers in nuclear power stations, the potential health hazards in terms of life expectancy would be comparable to those encountered in transportation and public utilities or in the construction industry. At the average radiation exposures received by these workers in practice, the potential health hazards are similar to those associated with safe categories of industries. Uranium mining remains a relativly hazardous occupation. In terms of absolute numbers, the genetic hazards, which are less well established, are thought to be smaller than the carcinogenic hazards of radiation when only the first generation is considered but to be of the same order of magnitude as the carcinogenic hazards when the total number of induced genetic disorders is summed over all generations

  19. Radiation hormesis in plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Lee, Byung Hun; Shin, In Chul; Lim, Young Taek

    2000-04-01

    This research was performed to investigate the effects of low dose {gamma}-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as subsequent high doses of radiation or Phytophthora blight of pepper could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant (POD) were accomplished in the plant irradiated with different dose of {gamma}-ray. (author)

  20. Rotating bubble membrane radiator

    Science.gov (United States)

    Webb, Brent J.; Coomes, Edmund P.

    1988-12-06

    A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

  1. Radiation Protection Proclamation

    International Nuclear Information System (INIS)

    A proclamation of the Government of Ethiopia, cited as the radiation protection proclamation number 79/1993 was prepared with the objective to establish a national radiation protection authority that formulates policies, controls and supervises activities involving all sources of radiation and lay down laws governing such activities in order to ensure public safety against associated hazards while allowing radiation related activities to be carried out for the benefit of the public . The Authority is guided by an inter-ministerial board and is accountable to the Ethiopian Science and Technology Commission

  2. Thermal-Radiation Program

    Science.gov (United States)

    Anderson, Gordon

    1993-01-01

    Thermal Radiation Analyzer System (TRASYS) computer program is software program having generalized capability to solve equations of radiation-related aspects of thermal-analysis problems. Computes total thermal-radiation environment for spacecraft in orbit. Software calculates internode-radiation-interchange data as well as data on rates of incidence and absorption of heat originating from environmental radiant sources. Provides data of both types in format directly usable by such thermal-analyzer programs as SINDA '85/FLUINT (available from COSMIC, program number MSC-21528). CRAY version of TRASYS (P25) written in FORTRAN 77. Other versions available upon request.

  3. Radiation in the environment

    International Nuclear Information System (INIS)

    In this brochure a general survey is presented of the SAWORA (Dutch abbrevation for 'Radiation aspects of dwelling-hygiene and related radio-ecological problems') research-program and its results. In this program emphasis lay upon indoor radiation burden. Therewith a distinction has to be made between external and internal radiation burden of men. In this context the external burden is accounted for by gamma radiation while the internal burden depends predominantly upon the concentration of radon in the air and radioactive materials in the body. After a short explanation of the concept of radiation in ch. 2, attention is devoted to gamma radiation and radon concentration in the open air in ch. 3, furthermore the radionuclide concentrations of the Dutch soil are discussed. In ch. 4 the radio-ecological aspects of fly-ash powder and gypsum are treated and, in ch. 5, those of building materials. Ch. 6 deals with indoor gamma-radiation. In ch. 7 a survey is given of radon concentrations in Dutch dwellings and the observed differences in concentrations. The synthesis of the various factors which influence the indoor radiation burden, the way in which radon and radondaughters enter the lungs and their contribution to the origin of lung carcinomas are discussed in ch. 8, together with the computer model with which the radiation aspects of certain building-technical developments can be calculated. Ch. 9 finally summarizes the most important results of the SAWORA program. 34 refs.; figs

  4. Potential theory of radiation

    Science.gov (United States)

    Chiu, Huei-Huang

    1989-01-01

    A theoretical method is being developed by which the structure of a radiation field can be predicted by a radiation potential theory, similar to a classical potential theory. The introduction of a scalar potential is justified on the grounds that the spectral intensity vector is irrotational. The vector is also solenoidal in the limits of a radiation field in complete radiative equilibrium or in a vacuum. This method provides an exact, elliptic type equation that will upgrade the accuracy and the efficiency of the current CFD programs required for the prediction of radiation and flow fields. A number of interesting results emerge from the present study. First, a steady state radiation field exhibits an optically modulated inverse square law distribution character. Secondly, the unsteady radiation field is structured with two conjugate scalar potentials. Each is governed by a Klein-Gordon equation with a frictional force and a restoring force. This steady potential field structure and the propagation of radiation potentials are consistent with the well known results of classical electromagnetic theory. The extension of the radiation potential theory for spray combustion and hypersonic flow is also recommended.

  5. Radiation protection textbook

    International Nuclear Information System (INIS)

    This textbook of radiation protection presents the scientific bases, legal and statutory measures and technical means of implementation of the radioprotection in the medical and industrial sectors, research and nuclear installations. It collects the practical information (organization, analysis of post, prevention, evaluation and risks management, the controls, the training and the information) usually scattered and the theoretical knowledge allowing every person using ionizing radiation: To analyze jobs in controlled areas, to watch the respect for the current regulations, to participate in the training and in the information of the staffs exposed to intervene in accidental situation. This third edition is widely updated and enriched by the most recent scientific and legal data concerning, notably, the human exposure, the dosimetry, the optimization of the radiation protection and the epidemiological inquiries. The contents is as follows: physics of ionizing radiation, ionizing radiation: origin and interaction with matter, dosimetry and protection against ionizing radiation, detection and measurement of ionizing radiation, radiobiology, legal measures relative to radiation protection, human exposure of natural origin, human exposure of artificial origin, medical, dental and veterinarian radiology, radiotherapy, utilization of unsealed sources in medicine and research, electronuclear industry, non nuclear industrial and aeronautical activities exposing to ionizing radiation, accidental exposures. (N.C.)

  6. Radiation hormesis in plant

    International Nuclear Information System (INIS)

    This research was performed to investigate the effects of low dose γ-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as subsequent high doses of radiation or Phytophthora blight of pepper could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant (POD) were accomplished in the plant irradiated with different dose of γ-ray. (author)

  7. Spacecraft Radiation Analysis

    Science.gov (United States)

    Harris, D. W.

    1972-01-01

    The radiation interface in spacecrafts using radioisotope thermoelectric generators is studied. A Monte Carlo analysis of the radiation field that includes scattered radiation effects, produced neutron and gamma photon isoflux contours as functions of distance from the RTG center line. It is shown that the photon flux is significantly depressed in the RTG axial direction because of selfshielding. Total flux values are determined by converting the uncollided flux values into an equivalent RTG surface source and then performing a Monte Carlo analysis for each specific dose point. Energy distributions of the particle spectra completely define the radiation interface for a spacecraft model.

  8. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent

  9. Radiation protection infrastructure

    International Nuclear Information System (INIS)

    A prerequisite for the safe use of ionizing radiation in a country is the availability of an adequate infrastructure to achieve the desired degree of protection. The extent of such an infrastructure, generally comprising regulatory mechanisms and technical capabilities for application and enforcement of regulations, has to be commensurate with the stage of technological development. The expanding application of ionizing radiation in medicine, industry and research calls for vigorous promotion of effective radiation protection efforts, not only to prevent any unsafe practices but also to assess correctly and provide authoritative information on the safety of adopted practices. Experience reveals that radiation protection practices vary considerably from one country to another. The regulatory structures and type of organization with regard to radiation protection are very different, depending on a number of factors such as the constitutional framework, the legal and administrative systems of the country concerned, the state of technical development, the status of application of radiation sources, the existence of research and associated institutions, and the technical skills and financial resources available. Radiation protection principles evolve with time as further experience is gained and as new research evidence becomes available. Regulation of radiation protection has to take account of such changes and adapt to changing conditions. Forty-eight papers from 29 Member States and two International Organizations were presented in nine scientific sessions. Topics included radiation protection regulation and licensing notification, registration, inspection and control programmes, education and training, the role of supporting institutions such as national laboratories and research institutes, the role of professional associations, the contribution of radiation protection services, and international activities. A concluding panel addressed development strategies to

  10. Tuning optical radiation for visual and nonvisual impact

    Science.gov (United States)

    Royer, Michael P.

    2011-12-01

    Brightness of Trichromatic Light Sources AIM: To examine the effect of tuning optical radiation on brightness perception for younger (18-25 years of age) and older (50 years of age or older) observers. METHODOLOGY: Participants made forced-choice evaluations of the brightness of a full factorial of stimulus pairs selected from two groups of four metameric stimuli. The large-field stimuli were created by systematically varying either the red or the blue primary of an RGB LED mixture. KEY FINDINGS: Light stimuli of equal illuminance and chromaticity do not appear equally bright to either younger or older subjects. The rank-order of brightness is not predicted by any current model of human vision or theory of brightness perception including Scotopic to Photopic or Cirtopic to Photopic ratio theory, prime color theory, correlated color temperature, photometry, color quality metrics, linear brightness models, or color appearance models. Age may affect brightness perception when short-wavelength primaries are used, especially those with a peak wavelength shorter than 450 nm. Optimizing RGB LED Mixtures AIM: To investigate potential tradeoffs between luminous efficacy, nonvisual efficacy, and color quality of RGB LED mixtures when the peak wavelength and full with half maximum of the primaries are varied. To identify mixtures suitable for architectural lighting which provide increased circadian stimulation. METHODOLOGY: Software to calculate the properties of RGB LED mixtures matching the chromaticity of blackbody radiation was developed using Microsoft Excel and Visual Basic. Excel Solver was used to perform a series of optimization routines, identifying high-performing mixtures that were then compared to traditional lamps. KEY FINDINGS: Trichromatic mixtures suitable for architectural interiors can outperform traditional lamps when luminous efficacy, nonvisual efficacy, and color quality are considered simultaneously. However, misplacement of radiant energy can result in poor

  11. Tuning optical radiation for visual and nonvisual impact

    Science.gov (United States)

    Royer, Michael P.

    2011-12-01

    Brightness of Trichromatic Light Sources AIM: To examine the effect of tuning optical radiation on brightness perception for younger (18-25 years of age) and older (50 years of age or older) observers. METHODOLOGY: Participants made forced-choice evaluations of the brightness of a full factorial of stimulus pairs selected from two groups of four metameric stimuli. The large-field stimuli were created by systematically varying either the red or the blue primary of an RGB LED mixture. KEY FINDINGS: Light stimuli of equal illuminance and chromaticity do not appear equally bright to either younger or older subjects. The rank-order of brightness is not predicted by any current model of human vision or theory of brightness perception including Scotopic to Photopic or Cirtopic to Photopic ratio theory, prime color theory, correlated color temperature, photometry, color quality metrics, linear brightness models, or color appearance models. Age may affect brightness perception when short-wavelength primaries are used, especially those with a peak wavelength shorter than 450 nm. Optimizing RGB LED Mixtures AIM: To investigate potential tradeoffs between luminous efficacy, nonvisual efficacy, and color quality of RGB LED mixtures when the peak wavelength and full with half maximum of the primaries are varied. To identify mixtures suitable for architectural lighting which provide increased circadian stimulation. METHODOLOGY: Software to calculate the properties of RGB LED mixtures matching the chromaticity of blackbody radiation was developed using Microsoft Excel and Visual Basic. Excel Solver was used to perform a series of optimization routines, identifying high-performing mixtures that were then compared to traditional lamps. KEY FINDINGS: Trichromatic mixtures suitable for architectural interiors can outperform traditional lamps when luminous efficacy, nonvisual efficacy, and color quality are considered simultaneously. However, misplacement of radiant energy can result in poor

  12. Radiative electron capture

    International Nuclear Information System (INIS)

    Some data are presented for radiative electron capture by fast moving ions. The radiative electron capture spectrum is shown for O8+ in Ag, along with the energy dependence of the capture cross-section. A discrepancy between earlier data, theoretical prediction, and the present data is pointed out. (3 figs) (U.S.)

  13. Radiation Protection in Guatemala

    International Nuclear Information System (INIS)

    The tasks connected with radiation protection are allocated to the National Institute for Nuclear Energy in Guatemala. Regulatory measures are further needed to identify the responsibilities of various authorities to ensure that all radiation workers are provided with personal dosemeters. (author)

  14. Radiation-induced pneumothorax

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, D.M.; Littman, P.; Gefter, W.B.; Miller, W.T.; Raney, R.B. Jr.

    1983-01-01

    Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis.

  15. Radiation-induced pneumothorax

    International Nuclear Information System (INIS)

    Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis

  16. Biological effects of radiation

    International Nuclear Information System (INIS)

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  17. Radiation'96. Conference handbook

    International Nuclear Information System (INIS)

    The conference program includes eight invited lectures which cover a range of contemporary topics in radiation science and technology. In addition, thirty-two oral papers were presented, along with forty-five posters. The conference handbook contains one-page precis or extended abstracts of all presentations, and is a substantial compendium of current radiation research in Australia

  18. New sources of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schimmerling, W.

    1979-09-01

    An attempt is made to select examples of radiation sources whose application may make new or unconventional demands on radiation protection and dosimetry. A substantial body of knowledge about high energy facilities exists and, partly for this reason, the great high energy accelerators are mentioned only briefly.

  19. Indoor ionizing radiation

    International Nuclear Information System (INIS)

    Radiation in indoor air is discussed in the perspective of the effective dose equivalents from other sources of radiation. Estimates of effective doses equivalents from indoor radon and its contribution to lung cancer incidence are reviewed. Swedish experiences with cost effective remedial actions are presented. The authors present optimal strategies for screening measurements and remedial actions in cost-benefit perspective. (author.)

  20. Radiation`96. Conference handbook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The conference program includes eight invited lectures which cover a range of contemporary topics in radiation science and technology. In addition, thirty-two oral papers were presented, along with forty-five posters. The conference handbook contains one-page precis or extended abstracts of all presentations, and is a substantial compendium of current radiation research in Australia.

  1. ALICE HMPID Radiator Vessel

    CERN Multimedia

    2003-01-01

    View of the radiator vessels of the ALICE/HMPID mounted on the support frame. Each HMPID module is equipped with 3 indipendent radiator vessels made out of neoceram and fused silica (quartz) windows glued together. The spacers inside the vessel are needed to stand the hydrostatic pressure. http://alice-hmpid.web.cern.ch/alice-hmpid

  2. Nonclassicality of Thermal Radiation

    OpenAIRE

    Johansen, Lars M.

    2004-01-01

    It is demonstrated that thermal radiation of small occupation number is strongly nonclassical. This includes most forms of naturally occurring radiation. Nonclassicality can be observed as a negative weak value of a positive observable. It is related to negative values of the Margenau-Hill quasi-probability distribution.

  3. Instrument for assaying radiation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Jody Rustyn; Farfan, Eduardo B.

    2016-03-22

    An instrument for assaying radiation includes a flat panel detector having a first side opposed to a second side. A collimated aperture covers at least a portion of the first side of the flat panel detector. At least one of a display screen or a radiation shield may cover at least a portion of the second side of the flat panel detector.

  4. Semiconductor radiation detection systems

    CERN Document Server

    2010-01-01

    Covers research in semiconductor detector and integrated circuit design in the context of medical imaging using ionizing radiation. This book explores other applications of semiconductor radiation detection systems in security applications such as luggage scanning, dirty bomb detection and border control.

  5. Electronics for radiation detection

    CERN Document Server

    2011-01-01

    Addresses the developments in the design of semiconductor detectors and integrated circuits, in the context of medical imaging using ionizing radiation. This book explains how circuits for radiation are built, focusing on practical information about how they are being used, rather than mathematical details.

  6. Occupational radiation exposure

    International Nuclear Information System (INIS)

    The X-ray and Radiation Protection Ordinances in the Federal Republic of Germany and Austria were discussed. The demands of protection ordinances can only be met if the monitoring of the radiation dose is ensured to a large extent. This was stated in the lectures on dosimetry, but also in those on the technical know-how and knowledge and the quality control in radiodiagnostics. The leukemia and cancer risk for persons exposed to radiation at work came also up for discussion, and the report on the re-evaluation of data about Hiroshima and Nagasaki showing a statistically recordable rise in cancer mortality has to be seen in connection with the radiation protection laws. A lecture was held on a radiation accident in Brazil in 1987 in order to give an example of an increased radiation exposure with a fatal result. It was an off-plant radiation accident. Since a physical dosimetry naturally cannot take place in such cases, it becomes necessary to inform oneself on the extent of the detriment by means of the detrimental characteristics of the irradiated organism. Also reported was the ''biological dosimetry'' of the radiation accident in Brazil. The 23 contributions have been separately recorded in the data base. (orig./DG) With 43 figs., 41 tabs

  7. Radiation protection of workers

    OpenAIRE

    Niu, Shengli

    2011-01-01

    Provides information about the size of the workforce affected by, and the occupational activities associated with, exposure to radiation and the relevant ILO instruments on the protection of workers. Mentions the ILO Convention on Radiation Protection, 1960 (No. 115), and its accompanying Recommendation (No. 114).

  8. Modular remote radiation monitor

    International Nuclear Information System (INIS)

    The Modular Remote Radiation Monitor (MRRM) is a novel radiation monitor suitable for monitoring environmental exposure to ionizing radiation. It is a portable compact-size low-power microprocessor-based electronic device which provides its monitoring data to other electronic systems, physically distant from it, by means of an electronic communication channel, which can be wired or wireless according to the requirements of each application. Besides its low-power highly-integrated circuit design, the Modular Remote Radiation Monitor is presented in a modular architecture, which promotes full compliance to the technical requirements of different applications while minimizing cost, size and power consumption. Its communication capability also supports the implementation of a network of multiple radiation monitors connected to a supervisory system, capable of remotely controlling each monitor independently as well as visualizing the radiation levels from all monitors. A prototype of the MRRM, functionally equivalent to the MRA-7027 radiation monitor, was implemented and connected to a wired MODBUS network of MRA-7027 monitors, responsible for monitoring ionizing radiation inside Argonauta reactor room at Instituto de Engenharia Nuclear. Based on the highly positive experimental results obtained, further design is currently underway in order to produce a consumer version of the MRRM. (author)

  9. Radiation Exposure and Pregnancy

    Science.gov (United States)

    ... radiation and was devel- oped by the Health Physics Society. Stabin M, Breitz H. Breast milk excretion of radiopharmaceuticals: Mechanisms, findings, and radiation dosimetry. Continuing Medical Education Article, Journal of Nuclear Medicine 41(5):863-873; 2000. U.S. Nuclear ...

  10. External Radiation Therapy

    Medline Plus

    Full Text Available ... D.: There are different forms of radiation for prostate cancer. They really boil down to two different types. There's what we call external beam treatment, which is given from an x-ray ... the prostate. [beeping] Narrator: The more common form of radiation ...

  11. Non-ionizing radiation

    International Nuclear Information System (INIS)

    The technical papers deal with health hazards from radiation, rules for the prevention of accidents, the risk of cancer and radiation effects, as well as the international standardization of UV, light, IR, LASER, static and low-frequency fields, electromagnetic fields, cardiac pacemakers, infrasound, ultrasound, and visual display units. (DG)

  12. New sources of radiation

    International Nuclear Information System (INIS)

    An attempt is made to select examples of radiation sources whose application may make new or unconventional demands on radiation protection and dosimetry. A substantial body of knowledge about high energy facilities exists and, partly for this reason, the great high energy accelerators are mentioned only briefly

  13. NASA's Space Radiation Laboratory

    Institute of Scientific and Technical Information of China (English)

    Shelley Canright; 陈功

    2004-01-01

    @@ Imagine a human spacecraft crew voyaging through space. A satellite sends a warning; energetic particles are being accelerated from the Sun's corona①,sending dangerous radiation toward the spacecraft, but the crewmembers aren't worried. Long before their journey, researchers on Earth conducted experiments to accurately measure the hazards of space radiation and developed new materials and countermeasures to protect them.

  14. Natural radiation environment III

    International Nuclear Information System (INIS)

    Separate abstracts were prepared for the 52 research papers presented at this symposium in April 1978. The major topics in this volume deal with penetrating radiation measurements, radiation surveys and population exposure, radioactivity in the indoor environment, and technologically enhanced natural radioactivity

  15. Space Radiation Risk Assessment

    Science.gov (United States)

    Blakely, E.

    Evaluation of potential health effects from radiation exposure during and after deep space travel is important for the future of manned missions To date manned missions have been limited to near-Earth orbits with the moon our farthest distance from earth Historical space radiation career exposures for astronauts from all NASA Missions show that early missions involved total exposures of less than about 20 mSv With the advent of Skylab and Mir total career exposure levels increased to a maximum of nearly 200 mSv Missions in deep space with the requisite longer duration of the missions planned may pose greater risks due to the increased potential for exposure to complex radiation fields comprised of a broad range of radiation types and energies from cosmic and unpredictable solar sources The first steps in the evaluation of risks are underway with bio- and physical-dosimetric measurements on both commercial flight personnel and international space crews who have experience on near-earth orbits and the necessary theoretical modeling of particle-track traversal per cell including the contributing effects of delta-rays in particle exposures An assumption for biologic effects due to exposure of radiation in deep space is that they differ quantitatively and qualitatively from that on earth The dose deposition and density pattern of heavy charged particles are very different from those of sparsely ionizing radiation The potential risks resulting from exposure to radiation in deep space are cancer non-cancer and genetic effects Radiation from

  16. Radiation Exposure and Cancer

    Science.gov (United States)

    ... Compensation Programs for People Exposed to Radiation as Part of Nuclear Weapons Testing Between 1945 and 1962, several countries tested nuclear weapons in the open air. The US government has passed several laws to ... radiation as part of nuclear testing programs who later develop certain ...

  17. National congress of radiation protection

    International Nuclear Information System (INIS)

    The congress of radiation protection tackled different areas of radiation protection. The impact of ionizing radiations on environment coming from radioactive activities. The biological radiation effects, the dosimetry, the different ways of doing relative to radiation protection,the risks analysis and the communications with populations, information about accidents and the lessons learned from them are included in this congress. (N.C.)

  18. Theory and practice of radiation

    International Nuclear Information System (INIS)

    This book deals with theory of the atomic energy; nuclear physics, radiochemistry, radiation chemistry and radiobiology. Also it says about protection radiation, management of waste of radiation, dealing of radiation including measuring the radiation energy and a neutron content and explanation of the laws and ordinances of nuclear energy. This is a book of preparations for examinations.

  19. Biophysical radiation effects

    International Nuclear Information System (INIS)

    The biological effectiveness of ionizing radiation is based upon the absorption of energy in molecular structures of a cell. Because of the quantum nature of radiation large fluctuations of energy concentration in subcellulare regions has to be considered. In addition both the spatial distribution of a sensitive molecular target and cellulare repair processes has to be taken into consideration for an assessment of radiation action. In radiation protection the difference between the quality factor and the Relative Biological Effectiveness has a fundamental meaning and will be discussed in more detail. The present report includes a short review on some relevant models on radiation action and a short discussion on effects of low dose irradiation. (orig.)

  20. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  1. Atmospheric Radiative Transfer

    Science.gov (United States)

    Perliski, Lori

    Because radiative transfer cuts across many scientific disciplines with applications including remote sensing, climate, atmospheric chemistry, and photobiology, there is a need for comprehensive books on this subject that can appeal to a wide readership. While Atmospheric Radiative Transfer takes strides toward filling this niche by addressing a broad range of topics, it is dry reading and suffers from lack of detail. The book was based on a graduate-level course taught at the University of Sciences and Technologies in Lille, France, and indeed, the text reads much like an expanded outline perhaps derived from lecture notes.Part one deals with general radiative transfer, and part two covers Earth's radiation budget, the climate system, and remote sensing techniques. The radiative transfer equation and solutions for absorbing and scattering atmospheres are discussed as are the details of absorption, such as energy levels, line strengths, line intensities, equivalent widths, and weak- and strong-line limits.

  2. Fading Hawking Radiation

    CERN Document Server

    Sakalli, I; Pasaoglu, H

    2012-01-01

    In this study, we explore a particular type Hawking radiation which ends with zero temperature and entropy. The appropriate black holes for this purpose are the linear dilaton black holes. In addition to the black hole choice, a recent formalism in which the Parikh-Wilczek's tunneling formalism amalgamated with quantum corrections to all orders in \\hbar is considered. The adjustment of the coefficients of the quantum corrections plays a crucial role on this particular Hawking radiation. The obtained tunneling rate indicates that the radiation is not pure thermal anymore, and hence correlations of outgoing quanta are capable of carrying away information encoded within them. Finally, we show in detail that when the linear dilaton black hole completely evaporates through such a particular radiation, entropy of the radiation becomes identical with the entropy of the black hole, which corresponds to "no information loss".

  3. Applications of ionizing radiations

    International Nuclear Information System (INIS)

    Developments in standard applications and brand new nuclear technologies, with high impact on the future of the agriculture, medicine, industry and the environmental preservation. The Radiation Technology Center (CTR) mission is to apply the radiation and radioisotope technologies in Industry, Health, Agriculture, and Environmental Protection, expanding the scientific knowledge, improving human power resources, transferring technology, generating products and offering services for the Brazilian society. The CTR main R and D activities are in consonance with the IPEN Director Plan (2011-2013) and the Applications of Ionizing Radiation Program, with four subprograms: Irradiation of Food and Agricultural Products; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for the Applications of Nuclear Techniques

  4. Radiation Damage Workshop

    Science.gov (United States)

    Stella, P. M.

    1984-01-01

    The availability of data regarding the radiation behavior of GaAs and silicon solar cells is discussed as well as efforts to provide sufficient information. Other materials are considered too immature for reasonable radiation evaluation. The lack of concern over the possible catastrophic radiation degradation in cascade cells is a potentially serious problem. Lithium counterdoping shows potential for removing damage in irradiated P-type material, although initial efficiencies are not comparable to current state of the art. The possibility of refining the lithium doping method to maintain high initial efficiencies and combining it with radiation tolerant structures such as thin BSF cells or vertical junction cells could provide a substantial improvement in EOL efficiencies. Laser annealing of junctions, either those formed ion implantation or diffusion, may not only improve initial cell performance but might also reduce the radiation degradation rate.

  5. Accelerator and radiation physics

    CERN Document Server

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  6. Chitosan and radiation chemistry

    Science.gov (United States)

    Chmielewski, Andrzej G.

    2010-03-01

    Chitosan as a raw material with special properties has drawn attention of scientists working in the field of radiation processing and natural polymer products development, and also of specialists working in the field of radiation protection and oncologists. Especially the applications concern reduced molecular weight chitosan which still retain its chemical structure; such form of the compound is fostering biological, physical and chemical reactivity of the product. Chitosan degrades into fragments under γ-ray or electron beam irradiation. Antibacterial properties of the product are applied in manufacturing hydrogel for wound dressing and additional healing properties can be achieved by incorporating in the hydrogel matrix chitosan bonded silver clusters. Another possible application of chitosan is in reducing radiation damage to the radiation workers or radiation cured patients. In the case of radioisotopes oral or respiratory chitosan-based materials can be applied as chelators. Applications of chitosan in oncology are also reported.

  7. Chitosan and radiation chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Chmielewski, Andrzej G., E-mail: a.chmielewski@ichtj.waw.p [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    2010-03-15

    Chitosan as a raw material with special properties has drawn attention of scientists working in the field of radiation processing and natural polymer products development, and also of specialists working in the field of radiation protection and oncologists. Especially the applications concern reduced molecular weight chitosan which still retain its chemical structure; such form of the compound is fostering biological, physical and chemical reactivity of the product. Chitosan degrades into fragments under gamma-ray or electron beam irradiation. Antibacterial properties of the product are applied in manufacturing hydrogel for wound dressing and additional healing properties can be achieved by incorporating in the hydrogel matrix chitosan bonded silver clusters. Another possible application of chitosan is in reducing radiation damage to the radiation workers or radiation cured patients. In the case of radioisotopes oral or respiratory chitosan-based materials can be applied as chelators. Applications of chitosan in oncology are also reported.

  8. Chitosan and radiation chemistry

    International Nuclear Information System (INIS)

    Chitosan as a raw material with special properties has drawn attention of scientists working in the field of radiation processing and natural polymer products development, and also of specialists working in the field of radiation protection and oncologists. Especially the applications concern reduced molecular weight chitosan which still retain its chemical structure; such form of the compound is fostering biological, physical and chemical reactivity of the product. Chitosan degrades into fragments under γ-ray or electron beam irradiation. Antibacterial properties of the product are applied in manufacturing hydrogel for wound dressing and additional healing properties can be achieved by incorporating in the hydrogel matrix chitosan bonded silver clusters. Another possible application of chitosan is in reducing radiation damage to the radiation workers or radiation cured patients. In the case of radioisotopes oral or respiratory chitosan-based materials can be applied as chelators. Applications of chitosan in oncology are also reported.

  9. Applications of ionizing radiations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    Developments in standard applications and brand new nuclear technologies, with high impact on the future of the agriculture, medicine, industry and the environmental preservation. The Radiation Technology Center (CTR) mission is to apply the radiation and radioisotope technologies in Industry, Health, Agriculture, and Environmental Protection, expanding the scientific knowledge, improving human power resources, transferring technology, generating products and offering services for the Brazilian society. The CTR main R and D activities are in consonance with the IPEN Director Plan (2011-2013) and the Applications of Ionizing Radiation Program, with four subprograms: Irradiation of Food and Agricultural Products; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for the Applications of Nuclear Techniques.

  10. Radiation Effects In Space

    Science.gov (United States)

    Tripathi, Ram K.

    2011-06-01

    Protecting space missions from severe exposures from radiation, in general, and long duration/deep space human missions, in particular, is a critical design driver, and could be a limiting factor. The space radiation environment consists of galactic cosmic rays (GCR), solar particle events (SPE), trapped radiation, and includes ions of all the known elements over a very broad energy range. These ions penetrate spacecraft materials producing nuclear fragments and secondary particles that damage biological tissues and microelectronic devices. One is required to know how every element (and all isotopes of each element) in the periodic table interacts and fragments on every other element in the same table as a function of kinetic energy ranging over many decades. In addition, the accuracy of the input information and database, in general and nuclear data in particular, impacts radiation exposure health assessments and payload penalty. After a brief review of effects of space radiation on materials and electronics, human space missions to Mars is discussed.

  11. Radiative impacts of ozone and other radiatively active components

    Energy Technology Data Exchange (ETDEWEB)

    Stordal, F.; Larsen, T.A.; Myhre, G.; Zetterberg, L.

    1996-07-01

    Radiative transfer calculations have been performed with two models of infrared radiation (broad band and line-by-line) and one model for ultraviolet and visible radiation (discrete ordinate method). The calculations are aimed at quantifying the radiative effects of radiatively active gases, in particular ozone. Seasonal variations and trends in the radiative forcing due to presence of ozone in the atmosphere is studied, based on observed ozone profiles from ozone soundings at selected Nordic locations. 15 refs., 28 figs., 8 tabs.

  12. Radiation effects on living systems

    International Nuclear Information System (INIS)

    This bibliography includes papers and reports by Atomic Energy of Canada Limited scientists concerning radiation effects on living systems. It is divided into three sections: Radiobiology, Radiation Biochemistry and Radiation Chemistry. (auth)

  13. Doses from Medical Radiation Sources

    Science.gov (United States)

    ... Radiation Protection and Measurements; NCRP Report 124; 1996. United Nations Scientific Committee on the Effects of Atomic Radiation. ... ionizing radiation, Vol. 1: Sources. New York, NY: United Nations Publishing; 2000. Russell JR, Stabin MG, Sparks RB, ...

  14. [Remote radiation planning support system].

    Science.gov (United States)

    Atsumi, Kazushige; Nakamura, Katsumasa; Yoshidome, Satoshi; Shioyama, Yoshiyuki; Sasaki, Tomonari; Ohga, Saiji; Yoshitake, Tadamasa; Shinoto, Makoto; Asai, Kaori; Sakamoto, Katsumi; Hirakawa, Masakazu; Honda, Hiroshi

    2012-08-01

    We constructed a remote radiation planning support system between Kyushu University Hospital (KUH) in Fukuoka and Kyushu University Beppu Hospital (KBH) in Oita. Between two institutions, radiology information system for radiotherapy division (RT-RIS) and radiation planning system (RTPS) were connected by virtual private network (VPN). This system enables the radiation oncologists at KUH to perform radiotherapy planning for the patients at KBH. The detail of the remote radiation planning support system in our institutions is as follows: The radiation oncologist at KBH performs radiotherapy planning and the data of the patients are sent anonymously to the radiation oncologists at KUH. The radiation oncologists at KUH receive the patient's data, access to RTPS at KBH, verify or change the radiation planning at KBH: Radiation therapy is performed at KBH according to the confirmed plan by the radiation oncologists at KUH. Our remote radiation planning system is useful for providing radiation therapy with safety and accuracy.

  15. The exergy of thermal radiation and its relevance in solar energy conversion

    Science.gov (United States)

    Wright, Sean Edward

    Driven by the importance of optimizing energy systems and technologies, the field of exergy analysis was developed to better illuminate process inefficiencies and evaluate performance. Exergy analysis provides important information and understanding that cannot be obtained from energy analysis. The field of exergy analysis is well formulated and understood except for thermal radiation (TR) heat transfer. The exergy flux, or maximum work obtainable, from TR has not been unambiguously determined. Moreover, many thermodynamic textbooks are misleading by incorrectly implying that the entropy and exergy transport with TR is calculated by using the same expressions that apply to heat conduction. Research on the exergy of TR was carried out by Petela. However, many researchers have considered Petela's analysis of the exergy of TR to be irrelevant to the conversion of TR fluxes. Petela's thermodynamic approach is considered irrelevant because, others argue, that it neglects fundamental issues that are specific to the conversion of fluxes, issues that are unusual in the context of exergy analysis. The purpose of the research in this thesis is to determine, using fundamental thermodynamic principles, the exergy flux of TR with an arbitrary spectrum and its relevance to solar radiation (SR) conversion. In this thesis it is shown that Petela's result can be used for the exergy flux of blackbody radiation (BR) and represents the upper limit to the conversion of SR approximated as BR. The thesis shows this by resolving a number of fundamental issues: (1)Inherent Irreversibility; (2)Definition of the Environment; (3)Inherent Emission; (4)Threshold Behaviour; (5)Effect of Concentrating TR. This thesis also provides a new expression, based on inherent irreversibility, for the exergy flux of TR with an arbitrary spectrum. Previous analysis by Karlsson assumes that reversible conversion of non-blackbody radiation (NBR) is theoretically possible, whereas this thesis presents evidence

  16. Radiation hormesis in plant

    International Nuclear Information System (INIS)

    This research was performed to investigate the effects of low dose gamma radiation on germination, early growth and yield in a wide range of vegetable crops. The stimulating effects of gamma radiation was evaluated through investigating germination rate, early growth and physiological activities such as enzyme activities, hormones and photosynthetic responses etc. Induction of increased shikonin production in the plants by low dose gamma radiation was challenged to open up the possibility of applying radiation hormesis to the industrial mass production system of the natural materials useful to humans. Effects of natural radiation emitted from solid ceramics was compared on the plants with those of low dose gamma radiation. Finally, activation of aged seeds by low dose gamma radiation, probably facilitating their commercial circulation in the agriculture, was challenged in association with an industrial seed company. Moreover, the shift in resistance of the crops to environmental stresses including UV and low temperature was addressed as well as DNA damage, repair and protein expression after gamma irradiation

  17. Beneficial uses of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fox, M.R.

    1991-10-01

    An overall decline in technical literacy within the American public has come at a time when technological advances are accelerating in the United States and around the world. This had led to a large communication gulf between the general public and the technologists. Nowhere is this more evident then with the topic of radiation. Regrettably, too few people know about sources of radiation, the pervasiveness, amounts, and variabilities, and do not have a true understanding of the environment in which we live. Nor do many people know that radiation has been used in beneficial ways for decades around the world. While the general public does not know of the scientific applications to which radiation has been deployed, it nevertheless had benefited tremendously from these efforts. Thanks to the well know properties of radiation, scientific ingenuity has found many uses of radiation in chemical and agricultural research, biomedical research, in the diagnoses and treatment of hundreds of types of diseases, in industrial applications, food irradiation, and many others. This paper provides a sample of the types of uses to which radiation has been used to help advance the betterment of humankind.

  18. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  19. Stimulated coherent transition radiation

    International Nuclear Information System (INIS)

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed

  20. Radiation therapy physics

    CERN Document Server

    Hendee, William R; Hendee, Eric G

    2013-01-01

    The Third Edition of Radiation Therapy Physics addresses in concise fashion the fundamental diagnostic radiologic physics principles as well as their clinical implications. Along with coverage of the concepts and applications for the radiation treatment of cancer patients, the authors have included reviews of the most up-to-date instrumentation and critical historical links. The text includes coverage of imaging in therapy planning and surveillance, calibration protocols, and precision radiation therapy, as well as discussion of relevant regulation and compliance activities. It contains an upd

  1. Nuclear medicine radiation dosimetry

    CERN Document Server

    McParland, Brian J

    2010-01-01

    Complexities of the requirements for accurate radiation dosimetry evaluation in both diagnostic and therapeutic nuclear medicine (including PET) have grown over the past decade. This is due primarily to four factors: growing consideration of accurate patient-specific treatment planning for radionuclide therapy as a means of improving the therapeutic benefit, development of more realistic anthropomorphic phantoms and their use in estimating radiation transport and dosimetry in patients, design and use of advanced Monte Carlo algorithms in calculating the above-mentioned radiation transport and

  2. Radiation and waste safety

    International Nuclear Information System (INIS)

    Most of the ionizing radiation that people are exposed to in day-to-day activities comes from natural, rather than manmade, sources. Nuclear radiation is a powerful source of benefit to mankind, whether applied in the field of medicine, agriculture, environmental management or elsewhere. The health effects of radiation - both natural and artificial - are relatively well understood and can be minimized through careful safety measures and practices. The Department of Technical Co-operation is sponsoring a programme with the support of the Nuclear Safety Department aiming at establishing Basic Safety Standard requirements in all Member States. (IAEA)

  3. Epistemology of radiation protection

    International Nuclear Information System (INIS)

    The scientific committee had assess Status of levels, effects and risks of ionizing radiation for General assembly, scientific community and public. The review of levels, sources and exposures. The natural sources of radiation include cosmic rays, terrestrial and artificial sources include medical issues, military activities, civil nuclear power occupational exposure and accidents. The global average exposure is 80% natural source, 20% medical examination 0.2% weapon fallout < 0.1% cherbonyl accidents and < 0.1 nuclear power. The effects of radiation incudes health effects, hereditable effects, bystander effects, and abscopal effects. The randon risks include lancer risk, plant and animal

  4. Radiation processed polysaccharide products

    International Nuclear Information System (INIS)

    Radiation crosslinking, degradation and grafting techniques for modification of polymeric materials including natural polysaccharides have been providing many unique products. In this communication, typical products from radiation processed polysaccharides particularly plant growth promoter from alginate, plant protector and elicitor from chitosan, super water absorbent containing starch, hydrogel sheet containing carrageenan/CM-chitosan as burn wound dressing, metal ion adsorbent from partially deacetylated chitin were described. The procedures for producing those above products were also outlined. Future development works on radiation processing of polysaccharides were briefly presented. (author)

  5. Radiation Protection Dosimetry

    International Nuclear Information System (INIS)

    The contributions presented during the seminar provided clear evidence that radiation protection of the patient plays an increasingly important role for manufacturers of radiological equipment and for regulatory bodies, as well as for radiologists, doctors and assistants. The proceedings of this seminar reflect the activities and work in the field of radiation protection of the patient and initiate further action in order to harmonize dosimetric measurements and calculations, to ameliorate education and training, to improve the technical standards of the equipment and to give a push to a more effective use of ionising radiation in the medical sector

  6. Radiation protection glossary

    International Nuclear Information System (INIS)

    The glossary is intended to be used as a terminology standard for IAEA documentation on radiation protection. An effort has been made to use definitions contained in internationally accepted publications such as recommendations of the International Commission on Radiological Protection (ICRP), standards of the International Organization for Standardization (ISO) and of the International Electrotechnical Commission (IEC), reports of the International Commission on Radiation Units and Measurements (ICRU), with only slight modifications in order to tailor them more closely to IAEA needs. The glossary is restricted to ionizing radiation

  7. Foundations of radiation hydrodynamics

    CERN Document Server

    Mihalas, Dimitri

    1999-01-01

    Radiation hydrodynamics is a broad subject that cuts across many disciplines in physics and astronomy: fluid dynamics, thermodynamics, statistical mechanics, kinetic theory, and radiative transfer, among others. The theory developed in this book by two specialists in the field can be applied to the study of such diverse astrophysical phenomena as stellar winds, supernova explosions, and the initial phases of cosmic expansion, as well as the physics of laser fusion and reentry vehicles. As such, it provides students with the basic tools for research on radiating flows.Largely self-contained,

  8. Radiation hormesis in plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Cun, Ki Jung; Shin, In Chul; Lim, Young Taek

    1999-04-01

    This research was performed to investigate the effects of low dose {gamma}-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as acid rain or soil types could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant enzyme (POD) were accomplished in the plant irradiated with difference dosage of {gamma}-ray.

  9. RADIATION PROTECTION IN IRAN

    OpenAIRE

    R. Abedinzadih; H. Parnianpour

    1980-01-01

    This paper presents the current activities on radiation protection in Iran. According to the Atomic Energy Organization Law of Iran the radiological safety is ascribed to the Atomic Energy Organization of Iran (A E O I) and the Radiation Protection Department (R P D) is the responsible organ within AEOI. R P D since it's establishment in 1975, with the aim to ensure the protection of man and his environment against any harmful effects of radiations, has embarked on a national development...

  10. Radiation hormesis in plant

    International Nuclear Information System (INIS)

    This research was performed to investigate the effects of low dose γ-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as acid rain or soil types could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant enzyme (POD) were accomplished in the plant irradiated with difference dosage of γ-ray

  11. Manual on radiation haematology

    International Nuclear Information System (INIS)

    Studies of the biological effects of ionizing radiation have led to the introduction of various measures to protect both the public and personnel engaged in occupations where they could be exposed to such radiations. Many recent studies deal with the basic mechanism of radiation injuries and with their treatment, and some of these investigations have been sponsored by the World Health Organization and the International Atomic Energy Agency. Fundamental studies of the blood-forming tissue have provided the information necessary for formulating recommendations of the International Commission on Radiological Protection. Heinecke in 1903 was the first to note damage to the haemato-poietic tissue after whole-body irradiation. Since that time we have learned much of the functions of the various components of the blood. Many studies have been undertaken to understand the proliferative capacities of the various 'stem' cells involved in the haematopoietic processes and the extent to which these processes can be interfered with by ionizing radiations. We now understand which are the reliable criteria by which radiation damage can be assessed from its effects on the haematopoietic system. In addition, much work has been done to determine how radiation injury to the hematopoietic system may be offset by therapy. In developing countries radiation is being increasingly applied in medical work and many other fields, and there is an immediate need to disseminate information relevant to radiation hazards. This Manual on Radiation Haematology is an attempt at a synthesis of much that is relevant to these matters. As the Contents List shows, many experts have contributed to the book. Their styles have been changed as little as possible. A certain amount of duplication of information could not be avoided; where an editorial decision to remove a passage would have resulted in losing the exact concept that the author wished to express, this passage has been retained. Information from

  12. Radiative-transfer models for supernovae IIb/Ib/Ic from binary-star progenitors

    Science.gov (United States)

    Dessart, Luc; Hillier, D. John; Woosley, Stan; Livne, Eli; Waldman, Roni; Yoon, Sung-Chul; Langer, Norbert

    2015-10-01

    We present 1D non-local thermodynamic equilibrium time-dependent radiative-transfer simulations for supernovae (SNe) of Type IIb, Ib, and Ic that result from the terminal explosion of the mass donor in a close-binary system. Here, we select three ejecta with a total kinetic energy of ≈1.2 × 1051 erg, but characterized by different ejecta masses (2-5 M⊙), composition, and chemical mixing. The Type IIb/Ib models correspond to the progenitors that have retained their He-rich shell at the time of explosion. The Type Ic model arises from a progenitor that has lost its helium shell, but retains 0.32 M⊙ of helium in a CO-rich core of 5.11 M⊙. We discuss their photometric and spectroscopic properties during the first 2-3 months after explosion, and connect these to their progenitor and ejecta properties including chemical stratification. For these three models, Arnett's rule overestimates the 56Ni mass by ≈ 50 per cent while the procedure of Katz et al., based on an energy argument, yields a more reliable estimate. The presence of strong C I lines around 9000Å prior to maximum is an indicator that the pre-SN star was underabundant in helium. As noted by others, the 1.08μm feature is a complex blend of C I, Mg II, and He I lines, which makes the identification of He uncertain in SNe Ibc unless other He I lines can be identified. Our models show little scatter in (V - R) colour 10 d after R-band maximum. We also address a number of radiative transfer properties of SNe Ibc, including the notion of a photosphere, the inference of a representative ejecta expansion rate, spectrum formation, blackbody fits and `correction factors'.

  13. Radiation monitoring by radiation effect of aerosol

    International Nuclear Information System (INIS)

    The high energy and high intensity accelerator facilities need the radiation monitoring with temporal and spatial resolutions. Numerical estimations are made for the radiation monitoring using the sampling method of aerosol Alanine. The aerosol Alanine put into the monitoring area through the duct. The intensity of radicals in the collected throughput Alanine of about 50 mg after passing through the monitoring area is measured by the ESR (Electron Spin Resonance) method. Key parameters in the system are the aerosol particle diameter and its intensity, the duct diameter and length, and the aerosol flow rate inside the duct. The maximum dose rate more than 108 Gy/h is possible to measure assuming the duct of 100 cm2 in area and 10 m in length, and the aerosol flow rate of 1000 L/min. The temporal resolution of the order of minutes is obtainable when the aerosol particle size is 0.1 μm. As a result of numerical estimation based on empirical simulations, it is to be promising to apply a proposed scheme to the radiation monitoring for accelerator fields. (Y. Tanaka)

  14. Intelligent Radiative Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An opportunity to boost energy efficiency in homes and buildings exists through the design of functional radiative properties in glass and other building materials....

  15. Radiation biology for environment

    International Nuclear Information System (INIS)

    Environmental pollution problems such as the green-house effect by increase of CO2, acid rain caused by flue gases, and contamination of chemicals and pesticides in foods and water, have become serious in the world with the rapid development of industry and agriculture. To solve some of these problems, radiation treatment has being applied for the removal of the contaminants from flue gases and waste water from industrial plants. On the other hand, the contribution of radiation biology for these environmental pollution problems is not direct but it has contributed indirectly in many fields. This paper describes the contributions of radiation biology for environment in the following two topics: 1) control of insects and microorganisms, and 2) application of radiation for agricultural wastes

  16. Radiation sensitive acrylate composition

    International Nuclear Information System (INIS)

    This application relates to radiation-sensitive compositions and more particularly to such compositions comprising acrylated esters. As used in this specification, the term acrylated esters refers to either acrylic or methacrylic acid resins. 3 tabs

  17. Radiation, health and society

    International Nuclear Information System (INIS)

    Experience from over one hundred years of working with radiation and follow-up studies of hundreds of thousands of workers has not revealed health hazards caused by normal exposure to natural radiation or to artificial radiation below the limits prescribed by ICRP. For the public, dose limits are only a fraction of those specified for occupationally exposed workers. While many people feel anxiety about the possibility of accidents in nuclear establishments and the short and long term effects on their health and on the health of their descendants, the risks from radiation must be seen in perspective. Human activities have added some artificial radioactive substances to the environment, but on the whole, that amount is far slighter than most people realize, and so slight that its impact on health can only be characterized as minimal

  18. Natural radiative cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.

    1979-01-01

    Natural radiative cooling at night was measured based on the surface-radiation spectrum after the heat balance of the surface exposed to the sun had been reradiated. A concept equivalent to the sky temperature and a concept useful for obtaining the net heat flux are discussed. The highest possible equilibrium temperature of the selective surface can be lowered; however, how to apply this practically is not yet known. A simple radiator, completely enclosed by a transparent screen, can produce a significant and inexpensive cooling effect. The results of experiments carried out in an area such as Padua, Italy, where the climate is not suitable for cooling purposes can still be predicted theoretically. The possibility of using the collector for heat collection during the day and as a radiator at night is indicated.

  19. Optimisation of radiation protection

    International Nuclear Information System (INIS)

    Optimisation of radiation protection is one of the key elements in the current radiation protection philosophy. The present system of dose limitation was issued in 1977 by the International Commission on Radiological Protection (ICRP) and includes, in addition to the requirements of justification of practices and limitation of individual doses, the requirement that all exposures be kept as low as is reasonably achievable, taking social and economic factors into account. This last principle is usually referred to as optimisation of radiation protection, or the ALARA principle. The NEA Committee on Radiation Protection and Public Health (CRPPH) organised an ad hoc meeting, in liaison with the NEA committees on the safety of nuclear installations and radioactive waste management. Separate abstracts were prepared for individual papers presented at the meeting

  20. Radiation Therapy (For Parents)

    Science.gov (United States)

    ... be some permanent changes to the color and elasticity of the skin. How can you help? Dress ... to Home and School Cancer Center Cancer Basics Types of Cancer Teens Get Radiation Therapy Chemotherapy Dealing ...

  1. Tin Can Radiation Detector.

    Science.gov (United States)

    Crull, John L.

    1986-01-01

    Provides instructions for making tin can radiation detectors from empty aluminum cans, aluminum foil, clear plastic, copper wire, silica gel, and fine, unwaxed dental floss put together with tape or glue. Also provides suggestions for activities using the detectors. (JN)

  2. Pregnancy and Radiation Exposure

    Science.gov (United States)

    ... had that might impact the development of their sperm or their eggs (ova) and their risk of ... your concerns with them. Radiation Exposure to the Sperm from Diagnostic X-Ray Studies There are no ...

  3. Monte Carlo Radiative Transfer

    CERN Document Server

    Whitney, Barbara A

    2011-01-01

    I outline methods for calculating the solution of Monte Carlo Radiative Transfer (MCRT) in scattering, absorption and emission processes of dust and gas, including polarization. I provide a bibliography of relevant papers on methods with astrophysical applications.

  4. Nanotechnology in radiation oncology.

    Science.gov (United States)

    Wang, Andrew Z; Tepper, Joel E

    2014-09-10

    Nanotechnology, the manipulation of matter on atomic and molecular scales, is a relatively new branch of science. It has already made a significant impact on clinical medicine, especially in oncology. Nanomaterial has several characteristics that are ideal for oncology applications, including preferential accumulation in tumors, low distribution in normal tissues, biodistribution, pharmacokinetics, and clearance, that differ from those of small molecules. Because these properties are also well suited for applications in radiation oncology, nanomaterials have been used in many different areas of radiation oncology for imaging and treatment planning, as well as for radiosensitization to improve the therapeutic ratio. In this article, we review the unique properties of nanomaterials that are favorable for oncology applications and examine the various applications of nanotechnology in radiation oncology. We also discuss the future directions of nanotechnology within the context of radiation oncology.

  5. Radiation protection and monitoring

    International Nuclear Information System (INIS)

    The present paper deals with the following topics: - Radiological quantities and units - Principles of radiological protection - Limits of doses and activity uptake - Activity discharges and monitoring - Radiation exposure and its calculation - Environmental monitoring - Personnel dosimetry. (orig./RW)

  6. External Radiation Therapy

    Medline Plus

    Full Text Available ... the cancer is not completely contained in the prostate or when the patient is older the treatment ... D.: There are different forms of radiation for prostate cancer. They really boil down to two different ...

  7. Radiative heat transfer

    CERN Document Server

    Modest, Michael F

    2013-01-01

    The third edition of Radiative Heat Transfer describes the basic physics of radiation heat transfer. The book provides models, methodologies, and calculations essential in solving research problems in a variety of industries, including solar and nuclear energy, nanotechnology, biomedical, and environmental. Every chapter of Radiative Heat Transfer offers uncluttered nomenclature, numerous worked examples, and a large number of problems-many based on real world situations-making it ideal for classroom use as well as for self-study. The book's 24 chapters cover the four major areas in the field: surface properties; surface transport; properties of participating media; and transfer through participating media. Within each chapter, all analytical methods are developed in substantial detail, and a number of examples show how the developed relations may be applied to practical problems. It is an extensive solution manual for adopting instructors. Features: most complete text in the field of radiative heat transfer;...

  8. Radiation chemistry of oils

    International Nuclear Information System (INIS)

    Full text : Primary investigations have been conducted at the end of the 1950th years in the area of radiation chemistry of the oils, the physical-chemical properties of crude oil have been investigated the influence of ionizing rays. This report by M. Malikzadeh is about the results of investigations carried out in the field of development of radiation chemistry. The power of the radiation dose and temperature-thermal effect of the collapse of Phentadekan -Oil, and oil fractions (200-400 degrees Celsium, 230-310 degrees Celsium) of radiation-thermal separation of olefins - Conversion of hydrogen from the transormation of black oil, bitumen and tar Kinetics of the above-mentioned processes was studied, the technical-economic indicators of the products were determined

  9. Radiation protection in medicine

    Energy Technology Data Exchange (ETDEWEB)

    Vano, E.; Holmberg, O.; Perez, M. R.; Ortiz, P.

    2016-08-01

    Diagnostic, interventional and therapeutic used of ionizing radiation are beneficial for hundreds of millions of people each year by improving health care and saving lives. In March 2001, the first International Conference on the Radiological Protection of Patients was held in Malaga, Spain, which led to an international action plan for the radiation protection of patients. Ten years after establishing the international action plan, the International Conference on Radiation Protection in Medicine: Setting the Scene for the Next Decade was held in Bonn, Germany, in December 2012. the main outcome of this conference was the so called Bonn Call for Action that identifies then priority actions to enhance radiation protection in medicine for the next decade. The IAEA and WHO are currently working in close cooperation to foster and support the implementation of these ten priority actions in Member States, but their implementation requires collaboration of national governments, international agencies, researchers, educators, institutions and professional associations. (Author)

  10. Breast radiation - discharge

    Science.gov (United States)

    ... during cancer treatment Eating extra calories when sick - adults Lymphedema - self-care Radiation therapy - questions to ask your doctor Safe eating during cancer treatment When you have diarrhea When you have nausea and vomiting Update Date ...

  11. Chest radiation - discharge

    Science.gov (United States)

    ... during cancer treatment Eating extra calories when sick - adults Lymphedema - self-care Radiation therapy - questions to ask your doctor Safe eating during cancer treatment When you have diarrhea When you have nausea and vomiting Update Date ...

  12. NASA Space Radiation Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory is a NASA funded facility, delivering heavy ion beams to a target area where scientists...

  13. The workers radiation protection

    International Nuclear Information System (INIS)

    This file gathers contributions and points of view from different actors of the workers radiation protection, included two foreign contributions making reference to Spanish and British practices. (N.C.)

  14. Radioactivity, radionuclides, radiation

    CERN Document Server

    Magill, Joseph

    2005-01-01

    RADIOACTIVITY – RADIONUCLIDES – RADIATION is suitable for a general audience interested in topical environmental and human health radiological issues such as radiation exposure in aircraft, food sterilisation, nuclear medicine, radon gas, radiation dispersion devices ("dirty bombs")… It leads the interested reader through the three Rs of nuclear science, to the forefront of research and developments in the field. The book is also suitable for students and professionals in the related disciplines of nuclear and radiochemistry, health physics, environmental sciences, nuclear and astrophysics. Recent developments in the areas of exotic decay modes (bound beta decay of ‘bare’ or fully ionized nuclei), laser transmutation, nuclear forensics, radiation hormesis and the LNT hypothesis are covered. Atomic mass data for over 3000 nuclides from the most recent (2003) evaluation are included.

  15. Physics for radiation protection

    CERN Document Server

    Martin, James E

    2013-01-01

    A much-needed working resource for health physicists and other radiation protection professionals, this volume presents clear, thorough, up-to-date explanations of the basic physics necessary to address real-world problems in radiation protection. Designed for readers with limited as well as basic science backgrounds, Physics for Radiation Protection emphasizes applied concepts and carefully illustrates all topics through examples as well as practice problems. Physics for Radiation Protection draws substantially on current resource data available for health physics use, providing decay schemes and emission energies for approximately 100 of the most common radionuclides encountered by practitioners. Excerpts of the Chart of the Nuclides, activation cross sections, fission yields, fission-product chains, photon attenuation coefficients, and nuclear masses are also provided.

  16. Radiation Protection Group

    CERN Multimedia

    2006-01-01

    The Radioactive Waste Section of the Radiation Protection Group wishes to inform you that the Radioactive Waste Treatment Centre will be closed on the afternoon of Tuesday 19 December 2006. Thank-you for your understanding.

  17. Radiation practices 1996

    Energy Technology Data Exchange (ETDEWEB)

    Havukainen, R. [ed.

    1997-05-01

    At the end of 1996, there were 1,762 valid safety licences in Finland for the use of radiation. In addition, there were 2,052 responsible parties for dental x-ray diagnostics. The registry of the Finnish Centre for Radiation and Nuclear Safety listed 13,360 radiation sources and 313 radionuclide laboratories. The import of radioactive substances amounted to 1.14 x 10{sup +16} Bq and export to 7.78 x 10{sup +13} Bq. A total of 4.02 x 10{sup +13} Bq of short-lived radionuclides were produced in Finland. There were 11,842 workers monitored for radiation exposure at 1,352 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of individual dosimeter readings) was 7.96 manSv in 1996, with nuclear power plant workers accounting for 69% of this total. The annual dosimeter reading of ten medical doctors (radiologists, interventional radiologists and cardiologists) and eight nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of dosimeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 242 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations where unusually high exposure to radiation was an unavoidable part of the task. Report was made of 12 incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Five of these cases occurred in radiotherapy, three in use of a radiation source in industry, three in transport of radiation sources and one in use of solarium appliances. Radiation-contaminated material was found in 17 shipments of scrap. (orig.)

  18. Radiation practices 1996

    International Nuclear Information System (INIS)

    At the end of 1996, there were 1,762 valid safety licences in Finland for the use of radiation. In addition, there were 2,052 responsible parties for dental x-ray diagnostics. The registry of the Finnish Centre for Radiation and Nuclear Safety listed 13,360 radiation sources and 313 radionuclide laboratories. The import of radioactive substances amounted to 1.14 x 10+16 Bq and export to 7.78 x 10+13 Bq. A total of 4.02 x 10+13 Bq of short-lived radionuclides were produced in Finland. There were 11,842 workers monitored for radiation exposure at 1,352 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of individual dosimeter readings) was 7.96 manSv in 1996, with nuclear power plant workers accounting for 69% of this total. The annual dosimeter reading of ten medical doctors (radiologists, interventional radiologists and cardiologists) and eight nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of dosimeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 242 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations where unusually high exposure to radiation was an unavoidable part of the task. Report was made of 12 incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Five of these cases occurred in radiotherapy, three in use of a radiation source in industry, three in transport of radiation sources and one in use of solarium appliances. Radiation-contaminated material was found in 17 shipments of scrap. (orig.)

  19. Radiation induced oral mucositis

    OpenAIRE

    P S Satheesh Kumar; Anita Balan; Arun Sankar; Tinky Bose

    2009-01-01

    Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i) With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii) who also received concomitant chemotherapy; (iii) who received a total dose over 5,000 cGy; and (iv) who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concer...

  20. Radiation shielding curtain

    International Nuclear Information System (INIS)

    A radiation shield is described in the form of a stranded curtain made up of bead-chains whose material and geometry are selected to produce a cross-sectional density that is the equivalent of 0.25 mm or more of lead and which curtain may be mounted on various radiological devices to shield against scattered radiation while offering a minimum of obstruction to the radiologist

  1. Preparing for radiation emergencies

    International Nuclear Information System (INIS)

    Over the past 40 years during man's expanded use of radioactive material there have been approximately 100 accidents which have resulted in injury to individuals. Most of these injuries have involved nuclear weapons development and testing rather than the peaceful applications of nuclear energy. A study of the sources causes and injuries resulting from this limited number of past events can provide guidance on the general type and magnitude of events which are most likely to occur in the future. The most common radiological and medical problems faced by the nuclear industry in the event of an accident are: internal and external overexposure to workers; radiation injury either from partial or whole-body exposure; and environmental contamination with the threat of contamination of individuals. Of the 100 or so radiation accidents which have been reported worldwide, the sources of uncontrolled radiation have been identified as shown in the table. These accidents have resulted in 16 fatalities and slightly more than 300 people each exposed to the equivalent of more than 25 rem total-body dose. In most discussions and national and international meetings the tendency has been to focus attention on large-scale nuclear accidents which are really exceedingly rare events. The purpose of the seminar on radiation emergency preparedness, held in India late last year, was to focus attention on the more common small-scale radiation events which are occurring in developing countries and which require modest efforts of advance planning and preparedness. As specific examples of the potential for radiation accidents, in India there are over 750 institutions using radiation sources: including more than 10 000 diagnostic X-ray units, 100 teletherapy units, and 90 brachytherapy units in medical applications; 332 radiography sources, and 138 nucleonic gauges in industrial applications. Of 77 accidents involving the loss of control over a radiation source, 47 involved industrial

  2. Radiation therapy physics

    CERN Document Server

    1995-01-01

    The aim of this book is to provide a uniquely comprehensive source of information on the entire field of radiation therapy physics. The very significant advances in imaging, computational, and accelerator technologies receive full consideration, as do such topics as the dosimetry of radiolabeled antibodies and dose calculation models. The scope of the book and the expertise of the authors make it essential reading for interested physicians and physicists and for radiation dosimetrists.

  3. Synchrotron radiation: science & applications

    OpenAIRE

    Aranda, Miguel A. G.

    2015-01-01

    This general talk is devoted to briefly introduce the main uses and applications of synchrotron radiation. An initial introduction will be dedicated to describe a synchrotron as a Large Facility devoted to produce photons that will be used to carry out excellent science. The five outstanding main characteristics of synchrotron radiation are: i) High brilliance and collimation ii) Wavelength tunability iii) Beamsize tunability iv) Defined polarization v) Time structure vi)...

  4. Report of board IV: Radiation damages and radiation induced diseases

    International Nuclear Information System (INIS)

    Board IV (radiation damage and radiation-induced diseases) worked on the effects of ionizing radiation on living organisms and studies the radiation damage it entailed. Investigations with cells or model systems serve to recognize certain causal relationships in an organism out of the diversity of reactions encountered. (orig./AK)

  5. Extension of radiative transfer code MOMO, matrix-operator model to the thermal infrared – Clear air validation by comparison to RTTOV and application to CALIPSO-IIR

    International Nuclear Information System (INIS)

    1-D radiative transfer code Matrix-Operator Model (MOMO), has been extended from [0.2−3.65μm] the band to the whole [0.2−100μm] spectrum. MOMO can now be used for the computation of a full range of radiation budgets (shortwave and longwave). This extension to the longwave part of the electromagnetic radiation required to consider radiative transfer processes that are features of the thermal infrared: the spectroscopy of the water vapor self- and foreign-continuum of absorption at 12μm and the emission of radiation by gases, aerosol, clouds and surface. MOMO's spectroscopy module, Coefficient of Gas Absorption (CGASA), has been developed for computation of gas extinction coefficients, considering continua and spectral line absorptions. The spectral dependences of gas emission/absorption coefficients and of Planck's function are treated using a k-distribution. The emission of radiation is implemented in the adding–doubling process of the matrix operator method using Schwarzschild's approach in the radiative transfer equation (a pure absorbing/emitting medium, namely without scattering). Within the layer, the Planck-function is assumed to have an exponential dependence on the optical-depth. In this paper, validation tests are presented for clear air case studies: comparisons to the analytical solution of a monochromatic Schwarzschild's case without scattering show an error of less than 0.07% for a realistic atmosphere with an optical depth and a blackbody temperature that decrease linearly with altitude. Comparisons to radiative transfer code RTTOV are presented for simulations of top of atmosphere brightness temperature for channels of the space-borne instrument MODIS. Results show an agreement varying from 0.1 K to less than 1 K depending on the channel. Finally MOMO results are compared to CALIPSO Infrared Imager Radiometer (IIR) measurements for clear air cases. A good agreement was found between computed and observed radiance: biases are smaller than 0

  6. Radiation processing in Hungary

    International Nuclear Information System (INIS)

    Hungary has 10.7 million population in 100,000 km2 territory. The gross national product is about $3,000 per capita per year. Hungary is a country with highly developed agriculture and medium degree developed industries. The Hungarian economy is an open economy because more than 40% of the national income is earned by export. The research and development works on various radiation processing have been performed for 25 years. In the Central Research Institute for Physics of the Hungarian Academy of Sciences, a laboratory was organized for the basic research of radiation chemistry and the moderator materials for nuclear reactors. Also the activities in the Central Research Institute for Chemistry, the Institute of Isotopes, the Research Institute for Plastics Industry, and the Central Research Institute for Food Industry are briefly reported. The largest radiation processing unit in Hungary is the automatic sterilization plant of Medicor Works in Debrecen with 350 kCi Co-60 source. The second important field of radiation processing is the irradiation of foods and agricultural products, and the radiation unit with 150 kCi Co-60 source is in the Central Research Institute for Food Industry. Radiation cross-linked polyethylene production, the production of wood-unsaturated polyester composite and enzyme immobilization are performed. (Kako, I.)

  7. Radiative forcing by contrails

    Directory of Open Access Journals (Sweden)

    R. Meerkötter

    Full Text Available A parametric study of the instantaneous radiative impact of contrails is presented using three different radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treated as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmosphere. The ice water content is varied as a function of ambient temperature. The model atmospheres include tropical, mid-latitude, and subarctic summer and winter atmospheres. Optically thin contrails cause a positive net forcing at top of the atmosphere. At the surface the radiative forcing is negative during daytime. The forcing increases with the optical depth and the amount of contrail cover. At the top of the atmosphere, a mean contrail cover of 0.1% with average optical depth of 0.2 to 0.5 causes about 0.01 to 0.03 Wm-2 daily mean instantaneous radiative forcing. Contrails cool the surface during the day and heat the surface during the night, and hence reduce the daily temperature amplitude. The net effect depends strongly on the daily variation of contrail cloud cover. The indirect radiative forcing due to particle changes in natural cirrus clouds may be of the same magnitude as the direct one due to additional cover.

    Key words. Atmospheric composition and structure (aerosols and particles · Meteorology and atmospheric dynamics (climatology · radiative processes

  8. Radiation and thyroid neoplasia

    International Nuclear Information System (INIS)

    It is now generally accepted that an association exists between external radiation administered to the head, neck, and upper thorax of infants, children, and adolescents and the subsequent development of neoplastic changes in the thyroid gland. Until recent years, external radiation was frequently administered to shrink an enlarged thymus or for the treatment of tonsillitis, adenoiditis, hearing loss, hemangioma, acne, tinea capitis, and other conditions. During the course of these treatments, the thyroid gland was exposed to scatter radiation. The use of external radiation therapy was then accepted practice, and its value was attested by many. Concern about the adverse effects was not initially appreciated, primarily because of the long periods of time between the radiation and the recognition of changes in the thyroid. The availability and effectiveness of other therapeutic measures and the growing concern about the delayed effects of radiation therapy when administered to the young for relatively benign conditions has, in recent years, largely eliminated use of this form of therapy, except in a few unusual conditions

  9. ISO radiation sterilization standards

    International Nuclear Information System (INIS)

    This presentation provides an overview of the current status of the ISO radiation sterilization standards. The ISO standards are voluntary standards which detail both the validation and routine control of the sterilization process. ISO 11137 was approved in 1994 and published in 1995. When reviewing the standard you will note that less than 20% of the standard is devoted to requirements and the remainder is guidance on how to comply with the requirements. Future standards developments in radiation sterilization are being focused on providing additional guidance. The guidance that is currently provided in informative annexes of ISO 11137 includes: device/packaging materials, dose setting methods, and dosimeters and dose measurement, currently, there are four Technical Reports being developed to provide additional guidance: 1. AAMI Draft TIR, 'Radiation Sterilization Material Qualification' 2. ISO TR 13409-1996, 'Sterilization of health care products - Radiation sterilization - Substantiation of 25 kGy as a sterilization dose for small or infrequent production batches' 3. ISO Draft TR, 'Sterilization of health care products - Radiation sterilization Selection of a sterilization dose for a single production batch' 4. ISO Draft TR, 'Sterilization of health care products - Radiation sterilization-Product Families, Plans for Sampling and Frequency of Dose Audits'

  10. Principles of radiation therapy

    International Nuclear Information System (INIS)

    Radiation oncology now represents the integration of knowledge obtained over an 80-year period from the physics and biology laboratories and the medical clinic. Such integration is recent; until the supervoltage era following World War II, the chief developments in these three areas for the most part were realized independently. The physics and engineering laboratories have now developed a dependable family of sources of ionizing radiations that can be precisely directed at tumor volumes at various depths within the body. The biology laboratory has provided the basic scientific support underlying the intensive clinical experience and currently is suggesting ways of using ionizing radiations more effectively, such as modified fractionation schedules relating to cell cycle kinetics and the use of drugs and chemicals as modifiers of radiation response and normal tissue reaction. The radiation therapy clinic has provided the patient stratum on which the acute and chronic effects of irradiation have been assessed, and the patterns of treatment success and failure identified. The radiation therapist has shared with the surgeon and medical oncologist the responsibility for clarifying the natural history of a large number of human neoplasms, and through such clarifications, has developed more effective treatment strategies. Several examples of this include the improved results in the treatment of Hodgkin's disease, squamous cell carcinoma of the cervix, seminoma, and epithelial neoplasms of the upper aerodigestive tract

  11. Radiation technology in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Vo Van Thuan [Institute for Nuclear Science and Technique, VAEC, Hanoi (Viet Nam)

    2001-03-01

    Most of researches and developments in the field of radiation technology that have completed in a decade before 1995 were concentrated to sterilization and food irradiation. A series of medical devices and products were the main commodities for research and application trials. Also, many kind of food have attracted the scientists and technologists to investigate the application and commercialization of irradiated food. In addition, the radiation technology also was utilized for processing of non-food items including herbs, medicinal produces, and tobacco material. Since 1996 VAEC and INST has realized the important role of radiation processing on natural polymers. Hence, along with the commercialization of radiation technology, three research teams were established for the target. This report reviews the recent activities and achievements on radiation technology in the country emphasizing on the radiation processing of polysaccharides. A number of polysaccharides, which originated from bio-/agro-wastes such as seaweed, shrimp shells, lignocelluloses, was modified or degraded by irradiation to prepare hydrogel and bio-active material using for health-care and crop production. (author)

  12. Radiation technology in Vietnam

    International Nuclear Information System (INIS)

    Most of researches and developments in the field of radiation technology that have completed in a decade before 1995 were concentrated to sterilization and food irradiation. A series of medical devices and products were the main commodities for research and application trials. Also, many kind of food have attracted the scientists and technologists to investigate the application and commercialization of irradiated food. In addition, the radiation technology also was utilized for processing of non-food items including herbs, medicinal produces, and tobacco material. Since 1996 VAEC and INST has realized the important role of radiation processing on natural polymers. Hence, along with the commercialization of radiation technology, three research teams were established for the target. This report reviews the recent activities and achievements on radiation technology in the country emphasizing on the radiation processing of polysaccharides. A number of polysaccharides, which originated from bio-/agro-wastes such as seaweed, shrimp shells, lignocelluloses, was modified or degraded by irradiation to prepare hydrogel and bio-active material using for health-care and crop production. (author)

  13. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles

    Directory of Open Access Journals (Sweden)

    Dörr Harald

    2011-11-01

    Full Text Available Abstract Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed.

  14. Radiation practices 1997

    Energy Technology Data Exchange (ETDEWEB)

    Havukainen, R. [ed.

    1998-05-01

    At the end of 1997, there were 1,753 valid safety licenses in Finland for the use of radiation. In addition, there were 2,065 responsible parties for dental x-ray diagnostics. The registry of STUK - Radiation and Nuclear Safety Authority listed 13,839 radiation sources and 302 radionuclide laboratories. The import of radioactive substances amounted to 1.09 x 10{sup +16} Bq and export to 2.4 x 10{sup +13} Bq. Short-lived radionuclides produced in Finland amounted to 5.2 x 10{sup +13} Bq. There were 11,773 workers monitored for radiation exposure at 1,316 work sites. Of these employees, 24% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of the individual dosemeter readings) was 6.6 Sv in 1997, with nuclear power plant workers accounting for 62% of this total. The annual dosemeter reading of thirteen medical doctors (radiologists, interventional radiologists and cardiologists) and six nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of the dosemeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 253 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations in which unusually high exposure to radiation was an unavoidable part of the task. Reports were made of four incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Two of these cases occurred in the medical use of radiation, one in the use of radiation sources in industry, and one in the use of solarium appliances. (orig.)

  15. Proceedings of radiation and occupational health Symposium

    International Nuclear Information System (INIS)

    This book compiled the papers presented at this symposium. The were papers on policy of radiation safety regulations, radiation safety measures, radiation in medicine and radiation protection, radiation measurements, radon measurement, radiation in petroleum industry, radiation monitoring and non ionizing radiation safety

  16. Some perspectives on radiation protection

    International Nuclear Information System (INIS)

    A brief review of the history and organizational structure of the NCRP is given. Summaries are given of a number of NCRP radiation protection guides dealing with hazards from 85Kr, radiation exposures from consumer products, basic radiation protection criteria, and doses from natural background radiation

  17. Radiation nephritis causing nephrotic syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Jennette, J.C.; Ordonez, N.G.

    1983-12-01

    Clinical symptoms of acute radiation nephritis with nephrotic syndrome developed in a fifty-six-year-old woman after abdominal radiation therapy for an astrocytoma of the spinal cord. The diagnosis of radiation nephritis was confirmed by renal biopsy. To our knowledge, this is the first documented case of radiation nephritis associated with nephrotic syndrome.

  18. Radiation Sensitization in Cancer Therapy.

    Science.gov (United States)

    Greenstock, Clive L.

    1981-01-01

    Discusses various aspects of radiation damage to biological material, including free radical mechanisms, radiation sensitization and protection, tumor hypoxia, mechanism of hypoxic cell radiosensitization, redox model for radiation modification, sensitizer probes of cellular radiation targets, pulse radiolysis studies of free radical kinetics,…

  19. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    In this review radiation produced by the nuclear industry is placed into context with other sources of radiation in our world. Human health effects of radiation, derivation of standards and risk estimates are reviewed in this document. The implications of exposing the worker and the general population to radiation generated by nuclear power are assessed. Effects of radiation are also reviewed. Finally, gaps in our knowledge concerning radiation are identified and current research on biological effects, on environmental aspects, and on dosimetry of radiation within AECL and Canada is documented in this report. (author)

  20. Radiation in Particle Simulations

    Energy Technology Data Exchange (ETDEWEB)

    More, R; Graziani, F; Glosli, J; Surh, M

    2010-11-19

    Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of megabars to thousands of gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present four methods that attempt a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The first method applies the Lienard-Weichert solution of Maxwell's equations for a classical particle whose motion is assumed to be known. The second method expands the electromagnetic field in normal modes (planewaves in a box with periodic boundary-conditions) and solves the equation for wave amplitudes coupled to the particle motion. The third method is a hybrid molecular dynamics/Monte Carlo (MD/MC) method which calculates radiation emitted or absorbed by electron-ion pairs during close collisions. The fourth method is a generalization of the third method to include small clusters of particles emitting radiation during close encounters: one electron simultaneously hitting two ions, two electrons simultaneously hitting one ion, etc. This approach is inspired by the virial expansion method of equilibrium statistical mechanics. Using a combination of these methods we believe it is possible to do atomic-scale particle

  1. Radiation processing of polysaccharides

    International Nuclear Information System (INIS)

    Radiation processing is a very convenient tool for imparting desirable effects in polymeric materials and it has been an area of enormous interest in the last few decades. The success of radiation technology for processing of synthetic polymers can be attributed to two reasons namely, their ease of processing in various shapes and sizes, and secondly, most of these polymers undergo crosslinking reaction upon exposure to radiation. In recent years, natural polymers are being looked at with renewed interest because of their unique characteristics, such as inherent biocompatibility, biodegradability and easy availability. Traditionally, the commercial exploitation of natural polymers like carrageenans, alginates or starch etc. has been based, to a large extent, on empirical knowledge. But now, the applications of natural polymers are being sought in knowledge - demanding areas such as pharmacy and biotechnology, which is acting as a locomotive for further scientific research in their structure-function relationship. Selected success stories concerning radiation processed natural polymers and application of their derivatives in the health care products industries and agriculture are reported. This publication will be of interest to individuals at nuclear institutions worldwide that have programmes of R and D and applications in radiation processing technologies. New developments in radiation processing of polymers and other natural raw materials give insight into converting them into useful products for every day life, human health and environmental remediation. The book will also be of interest to other field specialists, readers including managers and decision makers in industry (health care, food and agriculture) helping them to understand the important role of radiation processing technology in polysaccharides

  2. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    This annual report contains a summary of our current research. Some highlights include: experimental microdosimetry, track structure, extension of the Dual Radiation Action model to be time dependent, experiments showing that the reverse dose-rate effect for onogenic transformation, first rated for neutrons, has also been observed for charged particles of intermediate LET, an analysis of low dose-rate, research in hyperthermia, studies in molecular cloning, low dose rate studies, experimental studies on high LET, and molecular studies on DNA. 42 figs., 11 tabs

  3. Numerical Solution of the Radiative Transfer Equation: X-Ray Spectral Formation from Cylindrical Accretion onto a Magnetized Neutron Star

    Science.gov (United States)

    Fairnelli, R.; Ceccobello, C.; Romano, P.; Titarchuk, L.

    2011-01-01

    Predicting the emerging X-ray spectra in several astrophysical objects is of great importance, in particular when the observational data are compared with theoretical models. This requires developing numerical routines for the solution of the radiative transfer equation according to the expected physical conditions of the systems under study. Aims. We have developed an algorithm solving the radiative transfer equation in the Fokker-Planck approximation when both thermal and bulk Comptonization take place. The algorithm is essentially a relaxation method, where stable solutions are obtained when the system has reached its steady-state equilibrium. Methods. We obtained the solution of the radiative transfer equation in the two-dimensional domain defined by the photon energy E and optical depth of the system pi using finite-differences for the partial derivatives, and imposing specific boundary conditions for the solutions. We treated the case of cylindrical accretion onto a magnetized neutron star. Results. We considered a blackbody seed spectrum of photons with exponential distribution across the accretion column and for an accretion where the velocity reaches its maximum at the stellar surface and at the top of the accretion column, respectively. In both cases higher values of the electron temperature and of the optical depth pi produce flatter and harder spectra. Other parameters contributing to the spectral formation are the steepness of the vertical velocity profile, the albedo at the star surface, and the radius of the accretion column. The latter parameter modifies the emerging spectra in a specular way for the two assumed accretion profiles. Conclusions. The algorithm has been implemented in the XPEC package for X-ray fitting and is specifically dedicated to the physical framework of accretion at the polar cap of a neutron star with a high magnetic field (approx > 10(exp 12) G). This latter case is expected to be of typical accreting systems such as X

  4. Radiation in industrial processes

    International Nuclear Information System (INIS)

    The uses of ionizing radiation can be divided into two broad categories. First, it can be used as a tool of investigation, measurement and testing, and secondly, it can be a direct agent in inducing chemical processes. For example, radiation can help in the detecting and locating of malignant tumours, and it can be employed also for the destruction of those tumours. Again, it can reveal intricate processes of plant growth and, at the same time, can initiate certain processes which result in the growth of new varieties of plants. Similarly in industry, radiation is both a tool of detection, testing and measurement and an active agent for the initiation of useful chemical reactions. The initiation of chemical reactions usually requires larger and more powerful sources of radiation. Such radiation can be provided by substances like cobalt 60 and caesium 137 or by machines which accelerate nuclear particles to very high energies. Of the particle-accelerating machines, the most useful in this field are those which accelerate electrons to energies considerably higher than those possessed by the electrons (beta particles) emitted by radioactive substances. These high-energy radiations produce interesting reactions both in organic life and in materials for industry. Several of the papers presented at the Warsaw conference were devoted to the application of ionizing radiation to polymerization and other useful reactions in the manufacture and treatment of plastics. The polymerization of the ethylene series of hydro-carbons was discussed from various angles and the technical characteristics and requirements were described. It was pointed out by some experts that the cross-linking effect of radiation resulted in a superior product, opening the way to new applications of polyethylene. Irradiated polyethylene film has been sold for several years, and electrical wire has been made with irradiated polyethylene as the insulating jacket. Other reactions discussed included the cross

  5. New Approaches to Radiation Protection

    OpenAIRE

    Rosen, Eliot M.; Day, Regina; Singh, Vijay K.

    2015-01-01

    Radioprotectors are compounds that protect against radiation injury when given prior to radiation exposure. Mitigators can protect against radiation injury when given after exposure but before symptoms appear. Radioprotectors and mitigators can potentially improve the outcomes of radiotherapy for cancer treatment by allowing higher doses of radiation and/or reduced damage to normal tissues. Such compounds can also potentially counteract the effects of accidental exposure to radiation or delib...

  6. Radiation recall dermatitis with azithromycin

    OpenAIRE

    Vujovic, O.

    2010-01-01

    Radiation recall is a well-known phenomenon that involves the “recall” of an acute inflammatory reaction in a previously irradiated region after administration of certain drugs. The most common type of radiation recall is radiation recall dermatitis, which involves the reoccurrence of an acute inflammatory skin reaction in previously irradiated skin. Most radiation recall reactions are attributable to chemotherapeutic agents. One previously reported case of radiation recall dermatitis occurre...

  7. Foundations for radiation protection

    International Nuclear Information System (INIS)

    Full text; In 1996, the IAEA published the latest edition of the International Basic Safety Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources (Basic Safety Standards or BSS) comprising basic requirements to be filled in all activities involving radiation exposure. The standards define internationally harmonized requirements and provide practical guidance for public authorities and services, employers and workers, specialized radiation protection bodies, enterprises and health and safety communities. In the same year, the IAEA, through the technical cooperation programme, launched the Model Project on Upgrading Radiation Protection Infrastructure, a global initiative designed to help Member States establish the infrastructure needed to adhere to the BSS. To address the complexity of this task, the radiation protection team identified key elements, known as Thematic Safety Areas. These are: 1. Legislative Framework and Regulatory Infrastructure, Draft and put into effect radiation protection laws and regulations and establish and empower a national regulatory authority. 2. Occupational Exposure Control Protect the health and safety of each individual who faces the risk of radiation exposure in the workplace through individual and workplace monitoring programmes, including dose assessment, record keeping of doses and quality management. 3. Medical Exposure Control: Develop procedures and activities to control the exposure of patients undergoing diagnosis and/or treatment via diagnostic and interventional radiology, nuclear medicine or radiotherapy through staff training, provision of basic quality control equipment, and the establishment of quality assurance programmes. 4. Public and Environmental Exposure Control: Develop means to protect both the public and the environment including: a) programmes to register, inventory and provide safe storage of unused radioactive sources and material; b) procedures to control and safely

  8. Radiation produced biomaterials

    International Nuclear Information System (INIS)

    Medical advances that have prolonged the average life span have generated increased need for new materials that can be used as tissue and organ replacements, drug delivery systems and/or components of devices related to therapy and diagnosis. The first man-made plastic used as surgical implant was celluloid, applied for cranial defect repair. However, the first users applied commercial materials with no regard for their purity, biostability and post-operative interaction with the organism. Thus, these materials evoked a strong tissue reaction and were unacceptable. The first polymer which gained acceptance for man-made plastic was poly(methyl methacrylate). But the first polymer of choice, precursor of the broad class of materials known today as hydrogels, was poly(hydroxyethyl methacrylate) synthesized in the fifties by Wichterle and Lim. HEMA and its various combinations with other, both hydrophilic and hydrophobic, polymers are till now the most often used hydrogels for medical purposes. In the early fifties, the pioneers of the radiation chemistry of polymers began some experiments with radiation crosslinking, also with hydrophilic polymers. However, hydrogels were analyzed mainly from the point of view of phenomena associated with mechanism of reactions, topology of network, and relations between radiation parameters of the processes. Fundamental monographs on radiation polymer physics and chemistry written by Charlesby (1960) and Chapiro (1962) proceed from this time. The noticeable interest in application of radiation to obtain hydrogels for biomedical purposes began in the late sixties as a result of the papers and patents published by Japanese and American scientists. Among others, the team of the Takasaki Radiation Chemistry Research Establishment headed by Kaetsu as well as Hoffman and his colleagues from the Center of Bioengineering, University of Washington have created the base for spreading interest in the field of biomaterials formed by means of

  9. Radiative forcing by contrails

    Energy Technology Data Exchange (ETDEWEB)

    Meerkoetter, R.; Schumann, U. [DLR Oberpfaffenhofen, Wessling (Germany). Inst. fuer Phys. der Atmosphaere; Doelling, D.R.; Minnis, P. [National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center; Nakajima, T.; Tsushima, Y. [Tokyo Univ. (Japan). Center for Climate System Research

    1999-08-01

    A parametric study of the instantaneous radiative impact of contrails is presented using three different radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treated as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmosphere. The ice water content is varied as a function of ambient temperature. The model atmospheres include tropical, midlatitude, and subarctic summer and winter atmospheres. Optically thin contrails cause a positive net forcing at top of the atmosphere. At the surface the radiative forcing is negative during daytime. The forcing increases with the optical depth and the amount of contrail cover. At the top of the atmosphere, a mean contrail cover of 0.1% with average optical depth of 0.2 to 0.5 causes about 0.01 to 0.03 Wm{sup -2} daily mean instantaneous radiative forcing. Contrails cool the surface during the day and heat the surface during the night, and hence reduce the daily temperature amplitude. The net effect depends strongly on the daily variation of contrail cloud cover. The indirect radiative forcing due to particle changes in natural cirrus clouds may be of the same magnitude as the direct one due to additional cover. (orig.) 78 refs.

  10. Mankind, radiations and radioprotection

    International Nuclear Information System (INIS)

    After a brief recall of the historic knowledge on natural radioactivity, of the first developments of nuclear medicine and of the emergence of a necessary regulation of the use of these radiations, the author first proposes an overview of the relationship between radioactivity and exposure: sources of natural irradiation, sources of natural origin but modified by technology (medical exposure, professional exposure). Then, the author recalls the origin of radioprotection rules: the International Commission on Radiation Units and Measurements (ICRU), the International Commission on Radiological Protection (ICRP), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). He addresses the notion of dose with its different types: absorbed dose, equivalent dose, effective dose, specific case of internal exposure with the notion of engaged dose. He gives an overview of the effects of ionizing radiations: deterministic effects, global external irradiation, partial irradiations, and stochastic effects. The next part addresses the radiological protection system: scope of application, the three principles (justification, optimisation, and limitation), and dose limitations. Some matters of debate are reviewed: consequences of accidents of reactors, of Chernobyl and Fukushima (mortality by acute radiation syndrome, thyroid cancers, other cancers, leukaemia, non cancerous diseases, projections and conclusions after the Chernobyl accident), the notions of collective dose and of radio-toxicity, radio-induced cancers and genetic predisposition

  11. Ultraviolet radiation in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P.; Koskela, T.; Damski, J.; Supperi, A. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E. [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

    1996-12-31

    Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

  12. Surprising radiation detectors

    CERN Document Server

    Fleischer, Robert

    2003-01-01

    Radiation doses received by the human body can be measured indirectly and retrospectively by counting the tracks left by particles in ordinary objects like pair of spectacles, glassware, compact disks...This method has been successfully applied to determine neutron radiation doses received 50 years ago on the Hiroshima site. Neutrons themselves do not leave tracks in bulk matter but glass contains atoms of uranium that may fission when hurt by a neutron, the recoil of the fission fragments generates a track that is detectable. The most difficult is to find adequate glass items and to evaluate the radiation shield they benefited at their initial place. The same method has been used to determine the radiation dose due to the pile-up of radon in houses. In that case the tracks left by alpha particles due to the radioactive decay of polonium-210 have been counted on the superficial layer of the window panes. Other materials like polycarbonate plastics have been used to determine the radiation dose due to heavy io...

  13. SKIN RADIATION IN PANORAMIC

    Directory of Open Access Journals (Sweden)

    Herry Irawan

    2015-06-01

    Full Text Available Dental panoramic radiograph in Indonesia has been widely used. Modern diagnostic imaging equipment with minimum radiation is still very limited. One of the conditions in nuclear safety law, UU 10/1997, is an optimization of all radiation sources with DRL through skin dose measurements. In Indonesia, the national DRL has not been established yet, and there were no reports on the study of panoramic skin dose in Indonesia. The aim of this preliminary study was to obtain a panoramic skin dose radiation as reference to establish DRL in Indonesia. Panoramic radiographs of sixteen female and fifteen male patients, aged 4 – 48 years, were taken using the standard conventional method, with TLD chips attached in location groups. The chips were then read with the detector and integrator of BATAN, in high and low temperature condition at the same time. It was revealed that behind the right and left ear were the regions with the highest radiation dose received, followed by the back of the neck, left jaw, right jaw, and chin. The result of this study has shown the importance of DRL in Indonesia since the use of modern diagnostic imaging equipement that limits radiation dose to the minimum level is still very limited.

  14. Measurement of gravitational radiation

    International Nuclear Information System (INIS)

    The present article first describes some possible principles and mechanisms for detecting the gravitational radiation, and then outlines measuring techniques required for its detection. Some major issues concerned, present status of research and future prospects are also discussed. There are two possible detectors. One is the resonance type detector, which uses an elastic body with a considerable mass as antenna to catch the gravitational radiation. Gravitational radiation entering the elastic body causes an internal stress, resulting in vibration. Thus, a resonance type detector consists of an elastic body acting as antenna to catch gravitational radiation, and a transducer that converts the mechanical vibration of the antenna into electrical signals. The antenna and transducer should be contained in a vacuum highly protected from external acoustic and electromagnetic noise as well as external vibrations. Another possible detector uses a laser interferometer to detect a change in the distance between two bodies caused by gravitational radiation. Some techniques that could provide a tool for measuring such extremely small vibrations are also described and discussed. (N.K.)

  15. Project Radiation Protection - East

    International Nuclear Information System (INIS)

    The Swedish Government has allocated SEK 37.1 million for cooperation projects in radiation protection with countries in Central and Eastern Europe, particularly the Baltic states (Estonia, Latvia, Lithuania) and Russia. The Swedish Radiation Protection Inst. (SSI) is in charge of this program, which is often referred to as Radiation Protection - East. The general background of this cooperation program, its objectives, practical organization of the work etc. have been presented in the following reports: SSI Report No.93-08: Projekt Straalskydd Oest - Laegesrapport (March 1993); SSI Report No.93-29: Swedish Cooperation Program for Radiation Protection in Eastern and Central Europe (November 1993). The present report summarizes the work carried out up to and including September 1994. The more than 70 cooperation projects have been divided into the following categories: Upgrading of national authorities; Emergency preparedness, early warning; Nuclear power and research reactors; Instrumentation; Decommissioning, waste, environmental control; General radiation protection; Other projects; Project management and administrative support. Project criteria and a simple program for quality assurance and follow-up are presented briefly. A status report, including an economic overview, is given for all ongoing or already finished projects, together with future plans and a suggested budget for the next fiscal year

  16. Application of radiation-induced apoptosis in radiation oncology and radiation protection

    International Nuclear Information System (INIS)

    A rapid assay of the ability of lymphocytes to respond to radiation-induced damage is presented. Age and genetic dependence of radiation response have been quantified. The assay is sensitive to low doses of radiation. Its ability to assess the cytotoxic response of blood capillaries to radiation has been evaluated. (author)

  17. New Insights into White-Light Flare Emission from Radiative-Hydrodynamic Modeling of a Chromospheric Condensation

    CERN Document Server

    Kowalski, Adam F; Carlsson, Mats; Allred, Joel C; Uitenbroek, Han; Osten, Rachel A; Holman, Gordon

    2015-01-01

    (abridged) The heating mechanism at high densities during M dwarf flares is poorly understood. Spectra of M dwarf flares in the optical and near-ultraviolet wavelength regimes have revealed three continuum components during the impulsive phase: 1) an energetically dominant blackbody component with a color temperature of T $\\sim$ 10,000 K in the blue-optical, 2) a smaller amount of Balmer continuum emission in the near-ultraviolet at lambda $<$ 3646 Angstroms and 3) an apparent pseudo-continuum of blended high-order Balmer lines. These properties are not reproduced by models that employ a typical "solar-type" flare heating level in nonthermal electrons, and therefore our understanding of these spectra is limited to a phenomenological interpretation. We present a new 1D radiative-hydrodynamic model of an M dwarf flare from precipitating nonthermal electrons with a large energy flux of $10^{13}$ erg cm$^{-2}$ s$^{-1}$. The simulation produces bright continuum emission from a dense, hot chromospheric condensat...

  18. The impact of Dust Storms on both Solar Radiation and Sky temperature in Tabouk Saudi Arabia, theoretical Investigations

    Science.gov (United States)

    Maghrabi, Abdullrahman

    2016-04-01

    Dust particles affect both solar and terrestrial radiation by scattering and absorption and are therefore considered to be a significant climate-forcing factor. Dust storms are a very frequent phenomenon in Saudi Arabia. Several dust storm events occurred in Tabouk, northern region of Saudi Arabia, during the period between 2014-2015. In this study, simulations using the SMART model were conducted to investigate how the dusty conditions affected the solar irradiances during these events. Additionally, theoretical simulations were carried out using MODTRAN program to examine the changes in the infrared sky temperature during dusty conditions. The Atmospheric Optical Depth (AOD) measurements at (500 nm) were used as an input into both programs. The analysis showed that the dusty conditions significantly decrease the global and direct irradiances and increase the diffuse component compared with clear sky days. Also it was found that the dust storms increase the sky temperature in the atmospheric window (8-14 μm) such that the window emissions resembled those of a blackbody and the atmospheric window was almost closed.

  19. Detailed Radiative Transport Modeling of a Radiative Divertor

    CERN Document Server

    Wan, A S; Scott, H A; Post, D; Rognlien, T D

    1995-01-01

    An effective radiative divertor maximizes the utilization of atomic processes to spread out the energy deposition to the divertor chamber walls and to reduce the peak heat flux. Because the mixture of neutral atoms and ions in the divertor can be optically thick to a portion of radiated power, it is necessary to accurately model the magnitude and distribution of line radiation in this complex region. To assess their importance we calculate the effects of radiation transport using CRETIN, a multi-dimensional, non-local thermodynamic equilibrium simulation code that includes the atomic kinetics and radiative transport processes necessary to model the complex environment of a radiative divertor. We also include neutral transport to model radiation from recycling neutral atoms. This paper presents a case study of a high-recycling radiative divertor with a typical large neutral pressure at the divertor plate to estimate the impact of H line radiation on the overall power balance in the divertor region with conside...

  20. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    An important event of the year was the designation of our Laboratory as a Center for Radiological Research by the Dean of the Faculty of Medicine and Vice-President for Health Sciences. Center status acknowledges the size and importance of the research efforts in this area, and allows a greater measure of independence in administrative matters. While the name has changed from a Laboratory to a Center within the Medical School, the mission and charge remain the same. The efforts of the Center are a multidisciplinary mix of physics, chemistry, and biology, mostly at a basic level, with the admixture of a small proportion of pragmatic or applied research in support of radiation protection or radiation therapy. About a quarter of our funding, mostly individual research awards, could be regarded as in direct support of radiotherapy, with the remainder (an NCI program project grant and DOE grants) being in support of research addressing more basic issues. An important effort currently underway concerns ab-initio calculations of the dielectric response function of condensed water. This investigation has received the coveted designation, ''Grand Challenge Project,'' awarded by DOE to research work which represents ''distinct advance on a major scientific or engineering problem that is broadly recognized as important within the mission of the Department.''

  1. Radiation protection aspects of calibration laboratory for radiation monitoring instruments

    International Nuclear Information System (INIS)

    Radiation sources are widely used in various fields such as Medical, Industrial and Research etc. It is inevitable that radiation exposures will be received by the users of these radiation sources while handling the sources. It is essential to keep these exposures within the prescribed dose limits by the Atomic Energy Regulatory Board (AERB) to safe guard the radiation workers from the hazardous effects of radiation. Hence, the user institutions need to measure the radiation levels in and around the radiation installations using appropriate radiation monitoring instruments. There are several hundreds of Radiation Monitoring Instruments (RMIs) such as hand held radiation survey meters (RSM), area monitors, direct reading dosimeters (DRDs), secondary standard dosimeters (SSD) are being used by radiation facilities. Properly calibrated RMIs will provide the necessary confidence to the users of radiation sources in assessing the hazard potential. Periodic calibration of RMIs is a requirement under the Atomic Energy (Radiation Protection) Rules. As the number of users and in turn RMIs has been continuously increasing, AERB has initiated several regulatory measures in ensuring safe handling of radiation sources as well as establishment of calibration facilities

  2. Determination of the thermal radiation effect on an optical strontium lattice clock; Bestimmung des Einflusses thermischer Strahlung auf eine optische Strontium-Gitteruhr

    Energy Technology Data Exchange (ETDEWEB)

    Middelmann, Thomas

    2013-05-31

    Optical clocks have the potential to be 100 times more accurate than current best cesium atomic clocks within a fraction of the averaging time. This corresponds to a fractional uncertainty of the clock frequency on the level of 10{sup -18} and requires highaccuracy knowledge of systematic frequency shifts, such that they can be avoided or corrected for. In strontium optical lattice clocks an ensemble of ultracold strontium atoms is confined in an optical lattice, to allow for spectroscopy of the reference transition 5s{sup 2} {sup 1}S{sub 0}-5s5p {sup 3}P{sub 0} in the Lamb-Dicke regime. The by far largest systematic frequency shift of the strontium clock transition is caused by its high sensitivity to blackbody radiation (BBR). The knowledge of the resulting frequency shift limited the achievable clock uncertainty to about 1 x 10{sup -16}. In this thesis for the first time an experimental approach was followed, to determine the sensitivity of the strontium clock transition to blackbody radiation. At an environmental temperature of 300 K the resulting frequency shift corresponds to 2.277 8(23) Hz. The achieved uncertainty contributes with 5 x 10{sup -18} to the fractional systematic uncertainty of the clock frequency. The determination is based on a precision measurement of the difference of static polarizabilities of the two clock states {Delta}{alpha}{sub dc} = {alpha}(5s5p {sup 3}P{sub 0})-{alpha}(5s{sup 2} {sup 1}S{sub 0}) = 4.078 73(11) x 10{sup -39} Cm{sup 2} /V. For this the de Stark shift of the clock transition has been measured in the accurately known electric field of a precision plate capacitor, which has been developed in this work. The attained static polarizability difference {Delta}{alpha}{sub dc} corresponds to the first term of a power series of the sensitivity to BBR. Higher orders are accumulated as dynamic part of the BBR shift. Which has been modelled using {Delta}{alpha}{sub dc} and experimental data for other atomic properties. To

  3. Radiation techniques for acromegaly

    Directory of Open Access Journals (Sweden)

    Minniti Giuseppe

    2011-12-01

    Full Text Available Abstract Radiotherapy (RT remains an effective treatment in patients with acromegaly refractory to medical and/or surgical interventions, with durable tumor control and biochemical remission; however, there are still concerns about delayed biochemical effect and potential late toxicity of radiation treatment, especially high rates of hypopituitarism. Stereotactic radiotherapy has been developed as a more accurate technique of irradiation with more precise tumour localization and consequently a reduction in the volume of normal tissue, particularly the brain, irradiated to high radiation doses. Radiation can be delivered in a single fraction by stereotactic radiosurgery (SRS or as fractionated stereotactic radiotherapy (FSRT in which smaller doses are delivered over 5-6 weeks in 25-30 treatments. A review of the recent literature suggests that pituitary irradiation is an effective treatment for acromegaly. Stereotactic techniques for GH-secreting pituitary tumors are discussed with the aim to define the efficacy and potential adverse effects of each of these techniques.

  4. Radiative accidental matter

    CERN Document Server

    Sierra, D Aristizabal; Wegman, D

    2016-01-01

    Accidental matter models are scenarios where the beyond-the-standard model physics preserves all the standard model accidental and approximate symmetries up to a cutoff scale related with lepton number violation. We study such scenarios assuming that the new physics plays an active role in neutrino mass generation, and show that this unavoidably leads to radiatively induced neutrino masses. We systematically classify all possible models and determine their viability by studying electroweak precision data, big bang nucleosynthesis and electroweak perturbativity, finding that the latter places the most stringent constraints on the mass spectra. These results allow the identification of minimal radiative accidental matter models for which perturbativity is lost at high scales. We calculate radiative charged-lepton flavor violating processes in these setups, and show that $\\mu\\to e \\gamma$ has a rate well within MEG sensitivity provided the lepton-number violating scale is at or below $10^6\\,$ GeV, a value (natur...

  5. Radiation induced pesticidal microbes

    International Nuclear Information System (INIS)

    To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants

  6. Radiation emitting devices regulations

    International Nuclear Information System (INIS)

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  7. Digital Radiation image

    Directory of Open Access Journals (Sweden)

    Abou-Bakr Ramadan

    2012-03-01

    Full Text Available This work introduces a new way for data visualization. Its name is Digital Application name' Image. Normal digital image is created by digital camera or digital scanner but digital application name image is created by measurements of monitoring data. This work uses the data which is measured by radiation monitoring station and classifies it using fuzzy logic rules to create digital radiation image. The main unique advantage of digital radiation image is that it expresses thousands of measurements in a very clear form through only one picture while the maximum number of measurements does not exceed 100 with other conventional visualization methods. This feature gives a facility to view one year of all recorded measurements in only one photo. This picture helps the user to observe the behavior of thousands of measurements in few minutes instead of spending few hours for reviewing hundreds of charts for the same measurements.

  8. Radiation Protection. Chapter 3

    International Nuclear Information System (INIS)

    Medical exposure is the largest human-made source of radiation exposure, accounting for more than 95% of radiation exposure. Furthermore, the use of radiation in medicine continues to increase worldwide — more machines are accessible to more people, the continual development of new technologies and new techniques adds to the range of procedures available in the practice of medicine, and the role of imaging is becoming increasingly important in day to day clinical practice. The introduction of hybrid imaging technologies, such as positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography (SPECT)/CT, means that the boundaries between traditional nuclear medicine procedures and X ray technologies are becoming blurred. Worldwide, the total number of nuclear medicine examinations is estimated to be about 35 million per year

  9. Audible radiation monitor

    Energy Technology Data Exchange (ETDEWEB)

    Odell, D.M.C.

    1992-12-31

    This invention consists of a method and apparatus for monitoring ionizing radiation comprising radiation detectors in electrical connection with an isotopic analyzer and a device for producing chords to which each isotope is mapped so that the device produces a unique chord for each isotope. Preferably the chords are pleasing to the ear, except for chords representing unexpected isotopes, and are louder or softer depending on the level of radioactivity produced by each isotope, and musical instrument voices may be simulated in producing the chords as an aid to distinguishing similar-sounding chords. Because of the representation by chords, information regarding the level and composition of the radiation in an area can be conveyed to workers in that area more effectively and yet without distracting them.

  10. Radiation Protection Research: Radiobiology

    Energy Technology Data Exchange (ETDEWEB)

    Desaintes, C

    2000-07-01

    The main objectives of research in the field of radiobiology and epidemiology performed at the Belgian Nuclear Research Centre SCK-CEN are (1) to study cancer mortality in nuclear workers in Belgium; to document the feasibility of retrospective cohort studies in Belgium; (2) to participate in the IARC study; (3) to elucidate the molecular basis of the effects of ionising radiation in the mammalian embryo during the early phases of its development; (4) to assess the genetic risk of maternal exposure to ionizing radiation; (5) to elucidate the cellular mechanisms leading to brain damage after prenatal irradiation; (6) to advise authorities and to provide the general population with adequate information concerning the health risk arising from radiation exposure. Progress and major achievements in these topical areas in 1999 are reported.

  11. RF radiation safety handbook

    International Nuclear Information System (INIS)

    Radio frequency radiation can be dangerous in a number of ways. Hazards include electromagnetic compatibility and interference, electro-explosive vapours and devices, and direct effects on the human body. This book is a general introduction to the sources and nature of RF radiation. It describes the ways in which our current knowledge, based on relevant safety standards, can be used to safeguard people from any harmful effects of RF radiation. The book is designed for people responsible for, or concerned with, safety. This target audience will primarily be radio engineers, but includes those skilled in other disciplines including medicine, chemistry or mechanical engineering. The book covers the problems of RF safety management, including the use of measuring instruments and methods, and a review of current safety standards. The implications for RF design engineers are also examined. (Author)

  12. Transition Radiation Detectors

    CERN Document Server

    Andronic, A

    2012-01-01

    We review the basic features of transition radiation and how they are used for the design of modern Transition Radiation Detectors (TRD). The discussion will include the various realizations of radiators as well as a discussion of the detection media and aspects of detector construction. With regard to particle identification we assess the different methods for efficient discrimination of different particles and outline the methods for the quantification of this property. Since a number of comprehensive reviews already exist, we predominantly focus on the detectors currently operated at the LHC. To a lesser extent we also cover some other TRDs, which are planned or are currently being operated in balloon or space-borne astro-particle physics experiments.

  13. Properties of undulator radiation

    International Nuclear Information System (INIS)

    Properties of the radiation emitted by a plane sinusoidal undulator are calculated in the far field approximation. Software has been developed to calculate the spectral distribution and polarization of the radiated intensity I(E) at a point on (or integrated over) a cross sectional observation plane of the photon beam. Spatial distribution of monochromatic radiation and power density contours are also calculated. Spectral broadening caused by an electron beam of finite spatial distribution is considered. Dispersive properties of the photon beam, including the dependence on deflection parameter, are analyzed. It is shown that reasonably constant intensity distribution I(E) can be obtained by properly shaping the beam acceptance aperture. 5 refs., 11 figs

  14. Radiation induced pesticidal microbes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Yup; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.; Lim, D. S

    2001-01-01

    To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants.

  15. Radiation induced oral mucositis

    Directory of Open Access Journals (Sweden)

    P S Satheesh Kumar

    2009-01-01

    Full Text Available Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii who also received concomitant chemotherapy; (iii who received a total dose over 5,000 cGy; and (iv who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene

  16. Semiconductor radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Zane W. (Oak Ridge, TN); Burger, Arnold (Knoxville, TN)

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  17. Solar cell radiation handbook

    Science.gov (United States)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  18. Small Active Radiation Monitor

    Science.gov (United States)

    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

  19. Radiation Hazard Detector

    Science.gov (United States)

    1978-01-01

    NASA technology has made commercially available a new, inexpensive, conveniently-carried device for protection, of people exposed to potentially dangerous levels of microwave radiation. Microwaves are radio emissions of extremely high frequency. They can be hazardous but the degree of hazard is not yet well understood. Generally, it is believed that low intensity radiation of short duration is not harmful but that exposure to high levels can induce deep internal burns, affecting the circulatory and nervous systems, and particularly the eyes. The Department of Labor's Occupational Safety and Health Administration (OSHA) has established an allowable safe threshold of exposure. However, people working near high intensity sources of microwave energy-for example, radar antennas and television transmitters-may be unknowingly exposed to radiation levels beyond the safe limit. This poses not only a personal safety problem but also a problem for employers in terms of productivity loss, workman's compensation claims and possible liability litigation. Earlier-developed monitoring devices which warn personnel of dangerous radiation levels have their shortcomings. They can be cumbersome and awkward to use while working. They also require continual visual monitoring to determine if a person is in a dangerous area of radiation, and they are relatively expensive, another deterrent to their widespread adoption. In response to the need for a cheaper and more effective warning system, Jet Propulsion Laboratory developed, under NASA auspices, a new, battery-powered Microwave Radiation Hazard Detector. To bring the product to the commercial market, California Institute Research Foundation, the patent holder, granted an exclusive license to Cicoil Corporation, Chatsworth, California, an electronic components manufacturer.

  20. Proposed Radiation Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Davey, C. S.

    2004-07-01

    Current scientific evidence is that radiation at low levels is not harmful, but beneficial. This is borne out by both radiobiology and epidemiology. The ICRP 26 recommended limits of 50 mSv and 5 mSv per annum are comparable with the average natural background levels in Iran and Norway, respectively, and levels five times higher than that quoted for Iran are to be found in some populated parts of this world. The new limits proposed for ionising radiation are generated by comparison to existing recommended limits for essential minerals. There is a range of acceptable exposures to radiation, just as there is for minerals. The replacement for the ICRP 60 recommendations (20 mSv and 1 mSv for radiation workers and public respectively) should be higher limits of 200 mSv and 50 mSv. There should also be minimum recommended annual levels of 10 mSv, for both radiation workers and the public. The consequences of not proposing this change are continuing huge negative impacts to society. In cancer therapy, even the older guidelines caused unnecessary expense and delays. The cost to Canada is astronomical, when one considers the effect of the existing limits on the use of nuclear power, and the resulting use of hydrocarbons and the consequent increase in acid rain, etc. Of course, the same thing can be said of the entire world limited funds are diverted from areas where they would be better applied, and alternative solutions to societal needs are implemented, solutions which increase pollution and cause injury and death. It is time to reverse the current, expensive trend into misapplied ALARA, based on the paranoia about all things nuclear, which has developed since the linear no-threshold hypothesis was first proposed.propose the transition to a realistic and balanced approach to ionising radiation. (Author)

  1. Radiation-Ethionine Carcinogenesis

    International Nuclear Information System (INIS)

    This paper presents data on the possible co-carcinogenic effects of radiation and ethionine on the induction of liver tumours in female white rats, and data on the liver enzyme, tryptophan pyrrolase. Rats were divided into the following groups of approximately 100 animals each: two control groups; two groups given whole-body X-ray (200 and 400 rads); two groups given ethionine; and two groups given radiation-plus-ethionine. Ethionine was placed in the diet at a concentration of 0.25 per cent by weight. The radiation groups were exposed two weeks before being placed on the ethionine diet. Ten rats from each group were sacrified at 6-week intervals. After 54 weeks a total of 57 tumours had been observed in the rats receiving radiation-plus-ethionine, while only 17 liver tumours were found in the rats which received ethionine only. Of the rats receiving ethionine and 400 R, 38 developed liver tumours while 19 tumours were seen in rats given ethionine and 200 R. No liver tumours were found in control rats or in rats given radiation only. Statistical evaluation of.the data showed that radiation did not accelerate the rate of development of liver tumours but acted by decreasing the latent period of tumour appearance. Also, the latent period was shorter in the rats receiving 400 R plus ethionine than in those receiving 200 R and ethionine. The tryptophan pyrrolase studies indicated that the levels in the liver were not altered at any time during the study once the animals were placed on ethionine. The hepatomas had low basal enzyme levels and almost no inducible enzyme, while adjacent liver tissue had normal enzyme levels and responded to hydrocortisone. induction. (author)

  2. Comptonization in Ultra-Strong Magnetic Fields: Numerical Solution to the Radiative Transfer Problem

    Science.gov (United States)

    Ceccobello, C.; Farinelli, R.; Titarchuk, L.

    2014-01-01

    We consider the radiative transfer problem in a plane-parallel slab of thermal electrons in the presence of an ultra-strong magnetic field (B approximately greater than B(sub c) approx. = 4.4 x 10(exp 13) G). Under these conditions, the magnetic field behaves like a birefringent medium for the propagating photons, and the electromagnetic radiation is split into two polarization modes, ordinary and extraordinary, that have different cross-sections. When the optical depth of the slab is large, the ordinary-mode photons are strongly Comptonized and the photon field is dominated by an isotropic component. Aims. The radiative transfer problem in strong magnetic fields presents many mathematical issues and analytical or numerical solutions can be obtained only under some given approximations. We investigate this problem both from the analytical and numerical point of view, provide a test of the previous analytical estimates, and extend these results with numerical techniques. Methods. We consider here the case of low temperature black-body photons propagating in a sub-relativistic temperature plasma, which allows us to deal with a semi-Fokker-Planck approximation of the radiative transfer equation. The problem can then be treated with the variable separation method, and we use a numerical technique to find solutions to the eigenvalue problem in the case of a singular kernel of the space operator. The singularity of the space kernel is the result of the strong angular dependence of the electron cross-section in the presence of a strong magnetic field. Results. We provide the numerical solution obtained for eigenvalues and eigenfunctions of the space operator, and the emerging Comptonization spectrum of the ordinary-mode photons for any eigenvalue of the space equation and for energies significantly lesser than the cyclotron energy, which is on the order of MeV for the intensity of the magnetic field here considered. Conclusions. We derived the specific intensity of the

  3. Radiation monitoring at Belle

    CERN Document Server

    Zontar, D

    2003-01-01

    High beam currents at the KEK B factory lead to high radiation background (order of 100 krad/y, consisting mostly of spent electrons/positrons) around the interaction point where the silicon vertex detector is located. In order to monitor the background conditions close to the interaction point a radiation monitoring system has been developed and installed. It is based on 16 monitoring modules containing RadFET chip (containing 4 sensors) for measurement of total accumulated dose and PIN diodes for measurement of instantaneous dose rate.

  4. Detection of nuclear radiations

    International Nuclear Information System (INIS)

    A summary of the lectures about the ordinary detectors of nuclear radiations given by the author in the Courses of Introduction to Nuclear Engineering held at the JEN up to the date of publication is given. Those lectures are considered to be a necessary introduction to Nuclear Instrumentation and Applied electronics to Nuclear Engineering so it has been intent to underline those characteristics of radiation detectors that must be taken in consideration in choosing or designing the electronic equipment associated to them in order to take advantage of each detector possibilities. (Author) 8 refs

  5. Detection of nuclear radiations

    International Nuclear Information System (INIS)

    A summary of the lectures about the ordinary detectors of nuclear radiations explained by the author in the courses of Nuclear Engineering held at the J.E.N. up to the date of publication is given. Those lectures are considered to be a necessary introduction to Nuclear Instrumentation and Applied Electronics to Nuclear Engineering so it has been intended to underline those characteristics of radiation detectors that must be taken in consideration in choosing or designing the electronic equipment associated to them in order to take advantage of each detector possibilities. (Author)

  6. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    New measurements of the Σ+ and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K-p → Yπ where Y = Σ+ or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ+ → pγ to Σ+ → pπ0 and Λ → nγ to Λ → nπ0. The photons from weak radiative decays and from π0 decays were detected with modular NaI arrays. (orig.)

  7. Radiation dependent ionization model

    International Nuclear Information System (INIS)

    For laser created plasma simulation, hydrodynamics codes need a non-LTE atomic physics package for both EOS and optical properties (emissivity and opacity). However in XRL targets as in some ICF targets, high Z material can be found. In these cases radiation trapping can induce a significant departure from the optically thin ionization description. The authors present a method to change an existing LTE code into a non-LTE code with coupling of ionization to radiation. This method has very low CPU cost and can be used in 2D simulations

  8. Stimulated Resonant Radiation

    CERN Document Server

    Clerici, M; Rubino, E; Moss, D; Couairon, A; Légaré, F; Morandotti, R; Faccio, D

    2014-01-01

    Resonant radiation (RR) is emitted by solitons propagating in a waveguide or by filamenting pulses in bulk media. Recent studies have highlighted the possibility to stimulate RR also in weaker pulses that co-propogate with a pump pulse. We numerically and experimentally demonstrate that RR radiation can be stimulated employing a THz seed co-propagating in diamond with an intense 800 nm pulse. This way we predict and observe the stimulated emission of RR at 425 nm, thus bridging a spectral gap of more than six octaves and allowing the detection of THz pulses by means of a silicon-based device.

  9. The synchrotron radiation

    International Nuclear Information System (INIS)

    Synchrotron Radiation is a fantastic source of electromagnetic radiation the energy spectrum of which spreads continuously from the far infrared to hard X-rays. For this reason a wide part of the scientific community, fundamentalists as well as industry, is concerned by its use. We shall describe here the main properties of this light source and give two examples of application in the field of characterization of materials: EXAFS (Extended X-Ray Absorption Fine Structure) and X-ray fluorescence. (author). 8 figs., 21 refs

  10. Radiation and health. Benefit and risks

    International Nuclear Information System (INIS)

    The book on radiation and health covers the following topics: The world of radiation and waves; a sight into biology; if radiation hits the body; a sight into the internal radiation diagnostics; radiation hazards; the not always beloved sun; mobile phones, microwave ovens and power poles; healing with and due to radiation; radiation and food; radiation in the environment; generation and interactions of radiation in more detail; radiation effects in the cell - closer insight; radiation doses and measurement; epidemiology and its pitfalls; the system of radiation protection radiation accidents.

  11. Effects of radiation; Effets des radiations

    Energy Technology Data Exchange (ETDEWEB)

    Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France)

    2006-07-01

    The medical consequences of a whole-body irradiation come from the destruction of cells and inflammatory reactions it provokes. The most sensitive organs are the tissues that actively split. The embryo is particularly sensitive, from 200 mSv for the effects on the brain development. The reproduction functions are reached for man from 2000 mSv, the ovary sensitivity is less, the oocytes do not split after the fetus life. For adult the bone marrow outrage leads to the disappearing of blood cells (4000 mSv). The doses from 6000 to 10000 mSv lead the failure of the digestive system and lung. for the upper doses every tissue is reached, particularly by the effects on cells of blood vessels. Important brain dysfunctions appear beyond 10000 mSv. As regards the delayed effects of overexposures the epidemiology brings to light sanitary consequences of the exposure of the population to the ionizing radiations and requires that all the possible factors associated for that purpose are considered. About hereditary effects, it appears that moderate acute radiation exposures of even a relatively large human population must have little impact, in spite of the rate of spontaneous congenital deformations is of the order of 6 %. For the induction of cancers, it is not observed excess for doses lower than 200 mSv for adults and 100 mSv for children (the populations studied are survival people of hiroshima and Nagasaki, patients treated by irradiation, uranium miners, children exposed to radioactive iodine after Chernobylsk accident). To simplify an expression of the risk has been fixed to 5% of induced cancer by Sv for population and 4% by Sv for workers, the different being explained by the demography and the sensitivity of the youngest age groups. As regards the low doses of radiations, a bundle of convergent epidemiological observations notices the absence of effects of the low doses rates. Biological mechanisms, notably of repair are approached, then certain accidents (Goiania

  12. Radiation sterilization of livestock feeds

    International Nuclear Information System (INIS)

    The radiation sterilization of livestock feeds is not much used presently because the process is not known well, and the cost is relatively high. However, its effect of sterilization is absolute, the radiation-sterilized feeds are safe in both nutrition and toxicity, and do not affect the appetite of livestocks, and the radiation energy required is small. In the future, as in the sterilization of medical supplies, feed radiation sterilization plants should be established, to stabilize livestock industry and to contribute to the health control of experimental animals. The following matters are described: radiation, comparison between radiation sterilization and other sterilization methods, the practice of feed radiation sterilization, the adverse effects of radiation sterilization, economic aspect, and the situation of feed radiation sterilization in various countries. (Mori, K.)

  13. Radiative Magnetic Reconnection in Astrophysics

    CERN Document Server

    Uzdensky, Dmitri A

    2015-01-01

    I review a new rapidly growing area of high-energy plasma astrophysics --- radiative magnetic reconnection, i.e., a reconnection regime where radiation reaction influences reconnection dynamics, energetics, and nonthermal particle acceleration. This influence be may be manifested via a number of astrophysically important radiative effects, such as radiation-reaction limits on particle acceleration, radiative cooling, radiative resistivity, braking of reconnection outflows by radiation drag, radiation pressure, viscosity, and even pair creation at highest energy densities. Self-consistent inclusion of these effects in magnetic reconnection theory and modeling calls for serious modifications to our overall theoretical approach to the problem. In addition, prompt reconnection-powered radiation often represents our only observational diagnostic tool for studying remote astrophysical systems; this underscores the importance of developing predictive modeling capabilities to connect the underlying physical condition...

  14. 红外辐射测温仪检定装置不确定度评定%The uncertainties appraisement for the verification device of infrared radiation thermometer

    Institute of Scientific and Technical Information of China (English)

    张吉玲; 王惠霞

    2011-01-01

    为了保证量值传递的一致性,通过对红外辐射测温仪的感温器黑体炉进行不确定度的评定(误差分析与计算),确定其重复性、半年稳定性和不确定度验证等指标符合国家标准规范的要求,以便建立红外辐射测温仪检定装置,开展红外辐射测温仪的量值传递工作。%In order to ensuring the consistency of the quantitative value transfer,by the uncertainties appraisement for the temperature sensor of black-body furnace in infrared radiation thermometer,confirms the indexes of repeatability,half yearly stability and uncertainties to meet the needs of the national standard,so that establishes the verification device of infrared radiation thermometer,carries out the quantitative value transfer of the infrared radiation thermometer.

  15. Problems in astrophysical radiation hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Castor, J.I.

    1983-09-14

    The basic equations of radiation hydrodynamics are discussed in the regime that the radiation is dynamically as well as thermally important. Particular attention is paid to the question of what constitutes an acceptable approximate non-relativistic system of dynamical equations for matter and radiation in this regime. Further discussion is devoted to two classes of application of these ideas. The first class consists of problems dominated by line radiation, which is sensitive to the velocity field through the Doppler effect. The second class is of problems in which the advection of radiation by moving matter dominates radiation diffusion.

  16. Problems in astrophysical radiation hydrodynamics

    International Nuclear Information System (INIS)

    The basic equations of radiation hydrodynamics are discussed in the regime that the radiation is dynamically as well as thermally important. Particular attention is paid to the question of what constitutes an acceptable approximate non-relativistic system of dynamical equations for matter and radiation in this regime. Further discussion is devoted to two classes of application of these ideas. The first class consists of problems dominated by line radiation, which is sensitive to the velocity field through the Doppler effect. The second class is of problems in which the advection of radiation by moving matter dominates radiation diffusion

  17. Calculation codes in radiation protection, radiation physics and dosimetry

    International Nuclear Information System (INIS)

    These scientific days had for objective to draw up the situation of calculation codes of radiation transport, of sources estimation, of radiation doses managements and to draw the future perspectives. (N.C.)

  18. Detection of gravitational radiation

    Energy Technology Data Exchange (ETDEWEB)

    Holten, J.W. van [ed.

    1994-12-31

    In this report the main contributions presented at the named symposium are collected. These concern astrophysical sources of gravitational radiation, ultracryogenic gravitational wave experiments, read out and data analysis of gravitational wave antennas, cryogenic aspects of large mass cooling to mK temperatures, and metallurgical and engineering aspects of large Cu structure manufacturing. (HSI).

  19. Detection of gravitational radiation

    International Nuclear Information System (INIS)

    In this report the main contributions presented at the named symposium are collected. These concern astrophysical sources of gravitational radiation, ultracryogenic gravitational wave experiments, read out and data analysis of gravitational wave antennas, cryogenic aspects of large mass cooling to mK temperatures, and metallurgical and engineering aspects of large Cu structure manufacturing. (HSI)

  20. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  1. International Conference Medical Radiations

    International Nuclear Information System (INIS)

    Full text : The second edition of the international conference Medical radiation : research and applications which took place in Marrakech (Morocco) from 7 to 9 April 2010, was designed to bring together researchers and physicians from different countries who dedicated their talents and time to this endeavour. The conference's program defined goals were is to identify the most reliable techniques among the several tested so far and to establish the most practical standardized methodologies, taking into account such recent technological development in radiation medical research. The scientific objectives of this conference are as follows : present the state of the art of the various topics of the congress, give a progress report on the impact of the interaction of the various scientific and technical disciplinary fields (Medicine, Biology, Mathematics, Physics,..) on the applications of radiations in medicine, promote the interdisciplinary efforts of research among researchers, present new technologies and research and development tasks prepared in the field of medical radiations, contribute to the emergence of new ideas of research and development of new collaborations

  2. Mammography and radiation risk

    International Nuclear Information System (INIS)

    Breast cancer is the most frequent malignant neoplasia among women in Germany. The use of mammography as the most relevant diagnostic procedure has increased rapidly over the last decade. Radiation risks associated with mammography may be estimated from the results of numerous epidemiological studies providing risk coefficients for breast cancer in relation to age at exposure. Various calculations can be performed using the risk coefficients. For instance, a single mammography examination (bilateral, two views of each breast) of a women aged 45 may enhance the risk of developing breast cancer during her lifetime numerically from about 12% of 12.0036%. This increase in risk is lower by a factor of 3,300 as compared to the risk of developing breast cancer in the absence of radiation exposure. At the age of 40 or more, the benefit of mammography exceeds the radiation risk by a factor of about 100. At higher ages this factor increases further. Finally, the dualism of individual risk and collective risk is considered. It is shown that the individual risk of a patient, even after multiple mammography examinations, is vanishingly small. Nevertheless, the basic principle of minimising radiation exposure must be followed to keep the collective risk in the total population as low as reasonably achievable. (orig.)

  3. The acute radiation syndrome

    International Nuclear Information System (INIS)

    Symptoms and signs from medical aspects resulting from whole body exposure, or in the main part, to ionizing radiation are described. The dose-response relationship is studied and the exposure is divided in three parts: central nervous system syndrome, gastrointestinal syndrome and hematopoietic syndrome. Brief comments about the treatment are reported. (M.A.C.)

  4. Insects, isotopes and radiations

    International Nuclear Information System (INIS)

    The IAEA activity on coordinating the IAEA member-state efforts in the field of pest control is considered. A complex program of agricultural pest control (IPM), applied in many parts of the world is developed. The program provides for the use of natural means of control and cases of critical pest numbers-the use of insecticides. When controlling certain types of insects it is advisable to apply the 'large area control' methods which provide for the insect destruction in places of their concentration prior to migration. Methods of pest control over large areas also include radiation sexual sterilization method (SSM), application of insect phoromons (sexual attractants) to prevent mating, other types of chemical attractants, traps, mass cultivation and reproduction of parasite plants and animals, destroying insects, as well as improvement of host-plant resistance. A great attention is paid to isotope and radiation application in pest control (labelling, sexual sterilization using ionising radiation, radiation application in genetic engineering, mutant plant cultivation)

  5. Natural radiation environment III

    International Nuclear Information System (INIS)

    Separate abstracts were prepared for the 57 research papers presented at this symposium in April 1978 at Houston, Texas. This symposium provided a common forum for scientists in several disciplines that deal with natural radiation because there is an increasing interest in the environment as it pertains to human health and the competition for scarce energy and material resources

  6. Radiation risk estimation models.

    OpenAIRE

    Hoel, D. G.

    1987-01-01

    Cancer risk models and their relationship to ionizing radiation are discussed. There are many model assumptions and risk factors that have a large quantitative impact on the cancer risk estimates. Other health end points such as mental retardation may be an even more serious risk than cancer for those with in utero exposures.

  7. Thermodynamics of Radiation Modes

    Science.gov (United States)

    Pina, Eduardo; de la Selva, Sara Maria Teresa

    2010-01-01

    We study the equilibrium thermodynamics of the electromagnetic radiation in a cavity of a given volume and temperature. We found three levels of description, the thermodynamics of one mode, the thermodynamics of the distribution of frequencies in a band by summing over the frequencies in it and the global thermodynamics by summing over all the…

  8. Radiative accidental matter

    Science.gov (United States)

    Sierra, D. Aristizabal; Simoes, C.; Wegman, D.

    2016-07-01

    Accidental matter models are scenarios where the beyond-the-standard model physics preserves all the standard model accidental and approximate symmetries up to a cutoff scale related with lepton number violation. We study such scenarios assuming that the new physics plays an active role in neutrino mass generation, and show that this unavoidably leads to radiatively induced neutrino masses. We systematically classify all possible models and determine their viability by studying electroweak precision data, big bang nucleosynthesis and electroweak perturbativity, finding that the latter places the most stringent constraints on the mass spectra. These results allow the identification of minimal radiative accidental matter models for which perturbativity is lost at high scales. We calculate radiative charged-lepton flavor violating processes in these setups, and show that μ → eγ has a rate well within MEG sensitivity provided the lepton-number violating scale is at or below 5×105 GeV, a value (naturally) assured by the radiative suppression mechanism. Sizeable τ → μγ branching fractions within SuperKEKB sensitivity are possible for lower lepton-number breaking scales. We thus point out that these scenarios can be tested not only in direct searches but also in lepton flavor-violating experiments.

  9. Microwave Radiation Hazards

    Directory of Open Access Journals (Sweden)

    G. Subrahmanian

    1973-07-01

    Full Text Available Excessive exposure to microwave radiation could lead to biological damage. The criteria for maximum permissible exposure limits derived from experiments by several countries are discussed. Recommendations made for safety of operating personnel based on a recent protection survey are also presented.

  10. Hyperon Radiative Decay

    OpenAIRE

    Kaxiras, Efthimios; Soyeur, Madeleine; Moniz, Ernest J.

    1985-01-01

    The radiative decay widths of the low-lying strange baryons are calculated both within the relativistic quark bag model and the nonrelativistic potential model. These widths are found to depend sensitively upon the quark-model dynamics through multiplet mixing and q4¯q admixtures. The comparison between our calculated results and the very limited experimental data is discussed.

  11. Pregnancy and ionizing radiation

    International Nuclear Information System (INIS)

    Full text: In this report there will be presented the effects of ionizing radiation at the fetus and the necessary radioprotection. The biological results on the fetus, caused by the irradiation, depend on the dose of ionizing radiation that it receives and the phase of its evolution. The imminent effects of the irradiation can cause the fetus death, abnormalities and mental retardation, which are the result of overdose. The effects are carcinogenesis and leukemia, which are relative to the acceptable irradiating dose at the fetus and accounts about 0,015 % per 1 mSv. The effects of ionizing radiation depend on the phase of the fetus evolution: 1st phase (1st - 2nd week): presence of low danger; 2nd phase (3rd - 8th week): for doses >100 mSv there is the possibility of dysplasia; 3rd phase (8th week - birth): this phase concerns the results with a percentage 0,015 % per 1 mSv. We always must follow some rules of radioprotection and especially at Classical radiation use of necessary protocols (low dose), at Nuclear Medicine use of the right radioisotope and the relative field of irradiation for the protection of the adjacent healthy tissues and at Radiotherapy extreme caution is required regarding the dose and the treatment. In any case, it is forbidden to end a pregnancy when the pregnant undergoes medical exams, in which the uterus is in the beam of irradiation. The radiographer must always discuss the possibility of pregnancy. (author)

  12. Evidence for extra radiation?

    DEFF Research Database (Denmark)

    Hamann, J.

    2012-01-01

    during the marginalisation process, and we demonstrate that the effect is related to the fact that cosmic microwave background (CMB) data constrain N_eff only indirectly via the redshift of matter-radiation equality. Once present CMB data are combined with external information about, e.g., the Hubble...

  13. Radiation Therapy for Cancer

    Science.gov (United States)

    ... Cancers by Body Location Childhood Cancers Adolescent & Young Adult Cancers Metastatic Cancer Recurrent Cancer Research NCI’s Role in ... the affected area). Damage to the bowels, causing diarrhea and ... a second cancer caused by radiation exposure. Second cancers that develop ...

  14. Paradoxes of Thermal Radiation

    Science.gov (United States)

    Besson, U.

    2009-01-01

    This paper presents an analysis of the thermal behaviour of objects exposed to a solar-type flux of thermal radiation. It aims to clarify certain apparent inconsistencies between theory and observation, and to give a detailed exposition of some critical points that physics textbooks usually treat in an insufficient or incorrect way. In particular,…

  15. Genetic effects of radiation

    International Nuclear Information System (INIS)

    Data are reviewed from studies on the genetic effects of x radiation in mice and the extrapolation of the findings for estimating genetic hazards in man is discussed. Data are included on the frequency of mutation induction following acute or chronic irradiation of male or female mice at various doses and dose rates

  16. VDT Emissions Radiate Debate.

    Science.gov (United States)

    Morgan, Bill

    1990-01-01

    Discusses the possible health effects of electromagnetic fields of radiation that are emitted from video display terminals (VDTs). Responses from vendors in the computer industry are related, steps to reduce possible risks are suggested, and additional sources of information on VDTs are listed. (LRW)

  17. Nanofocusing of electromagnetic radiation

    DEFF Research Database (Denmark)

    Gramotnev, D. K.; Bozhevolnyi, Sergey I.

    2014-01-01

    Nanofocusing of electromagnetic radiation, that is, reducing the cross sections of propagating optical modes far beyond the diffraction limit in dielectric media, can be achieved in tapered metal-dielectric waveguides that support surface plasmon-polariton modes. Although the main principles...

  18. External Radiation Therapy

    Medline Plus

    Full Text Available Narrator: When the cancer is not completely contained in the prostate or when the patient is older the treatment that is frequently used ... There are different forms of radiation for prostate cancer. They really boil down to two different types. ...

  19. Radiation Induced Fermion Resonance

    OpenAIRE

    Esposito, S.; M. W. Evans; Recami, E.

    1998-01-01

    The Dirac equation is solved for two novel terms which describe the interaction energy between the half integral spin of a fermion and the classical, circularly polarized, electromagnetic field. A simple experiment is suggested to test the new terms and the existence of radiation induced fermion resonance.

  20. Thermostatic Radiator Valve Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J.; Ansanelli, E.

    2015-01-01

    A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market.