Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions

DOE PAGES

Nagayama, T.; Bailey, J. E.; Loisel, G.; ...

2016-02-05

Recently, frequency-resolved iron opacity measurements at electron temperatures of 170–200 eV and electron densities of (0.7 – 4.0) × 10 22 cm –3 revealed a 30–400% disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015)]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulationsmore » that reproduce the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. Furthermore, these simulations bridge the static-uniform picture of the data interpretation and the dynamic-gradient reality of the experiments, and they will allow us to quantitatively assess the impact of effects neglected in the data interpretation.« less

Physics and biophysics experiments needed for improved risk assessment in space

NASA Astrophysics Data System (ADS)

Sihver, L.

To improve the risk assessment of radiation carcinogenesis, late degenerative tissue effects, acute syndromes, synergistic effects of radiation and microgravity or other spacecraft factors, and hereditary effects, on future LEO and interplanetary space missions, the radiobiological effects of cosmic radiation before and after shielding must be well understood. However, cosmic radiation is very complex and includes low and high LET components of many different neutral and charged particles. The understanding of the radiobiology of the heavy ions, from GCRs and SPEs, is still a subject of great concern due to the complicated dependence of their biological effects on the type of ion and energy, and its interaction with various targets both outside and within the spacecraft and the human body. In order to estimate the biological effects of cosmic radiation, accurate knowledge of the physics of the interactions of both charged and non-charged high-LET particles is necessary. Since it is practically impossible to measure all primary and secondary particles from all projectile-target-energy combinations needed for a correct risk assessment in space, accurate particle and heavy ion transport codes might be a helpful instrument to overcome those difficulties. These codes have to be carefully validated to make sure they fulfill preset accuracy criteria, e.g. to be able to predict particle fluence and energy distributions within a certain accuracy. When validating the accuracy of the transport codes, both space and ground-based accelerator experiments are needed. In this paper current and future physics and biophysics experiments needed for improved risk assessment in space will be discussed. The cyclotron HIRFL (heavy ion research facility in Lanzhou) and the new synchrotron CSR (cooling storage ring), which can be used to provide ion beams for space related experiments at the Institute of Modern Physics, Chinese Academy of Sciences (IMP-CAS), will be presented together with the physical and biomedical research performed at IMP-CAS.

Thermal Sensitive Foils in Physics Experiments

ERIC Educational Resources Information Center

Bochnícek, Zdenek; Konecný, Pavel

2014-01-01

The paper describes a set of physics demonstration experiments where thermal sensitive foils are used for the detection of the two dimensional distribution of temperature. The method is used for the demonstration of thermal conductivity, temperature change in adiabatic processes, distribution of electromagnetic radiation in a microwave oven and…

Studying the physical basis of global warming: thermal effects of the interaction between radiation and matter and greenhouse effect

NASA Astrophysics Data System (ADS)

Besson, Ugo; De Ambrosis, Anna; Mascheretti, Paolo

2010-03-01

We present a teaching module dealing with the thermal effects of interaction between radiation and matter, the infrared emission of bodies and the greenhouse effect devoted to university level and teacher education. The module stresses the dependence of the optical properties of materials (transparency, absorptivity and emissivity) on radiation frequency, as a result of interaction between matter and radiation. Multiple experiences are suggested to favour a progressive construction of knowledge on the physical aspects necessary to understand the greenhouse effect and global warming. Some results obtained with university students are briefly reported.

Modeling Laser-Driven Laboratory Astrophysics Experiments Using the CRASH Code

NASA Astrophysics Data System (ADS)

Grosskopf, Michael; Keiter, P.; Kuranz, C. C.; Malamud, G.; Trantham, M.; Drake, R.

2013-06-01

Laser-driven, laboratory astrophysics experiments can provide important insight into the physical processes relevant to astrophysical systems. The radiation hydrodynamics code developed by the Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan has been used to model experimental designs for high-energy-density laboratory astrophysics campaigns on OMEGA and other high-energy laser facilities. This code is an Eulerian, block-adaptive AMR hydrodynamics code with implicit multigroup radiation transport and electron heat conduction. The CRASH model has been used on many applications including: radiative shocks, Kelvin-Helmholtz and Rayleigh-Taylor experiments on the OMEGA laser; as well as laser-driven ablative plumes in experiments by the Astrophysical Collisionless Shocks Experiments with Lasers (ACSEL) collaboration. We report a series of results with the CRASH code in support of design work for upcoming high-energy-density physics experiments, as well as comparison between existing experimental data and simulation results. This work is funded by the Predictive Sciences Academic Alliances Program in NNSA-ASC via grant DEFC52- 08NA28616, by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-FG52-09NA29548, and by the National Laser User Facility Program, grant number DE-NA0000850.

A Radiation Laboratory Curriculum Development at Western Kentucky University

NASA Astrophysics Data System (ADS)

Barzilov, Alexander P.; Novikov, Ivan S.; Womble, Phil C.

2009-03-01

We present the latest developments for the radiation laboratory curriculum at the Department of Physics and Astronomy of Western Kentucky University. During the last decade, the Applied Physics Institute (API) at WKU accumulated various equipment for radiation experimentation. This includes various neutron sources (computer controlled d-t and d-d neutron generators, and isotopic 252 Cf and PuBe sources), the set of gamma sources with various intensities, gamma detectors with various energy resolutions (NaI, BGO, GSO, LaBr and HPGe) and the 2.5-MeV Van de Graaff particle accelerator. XRF and XRD apparatuses are also available for students and members at the API. This equipment is currently used in numerous scientific and teaching activities. Members of the API also developed a set of laboratory activities for undergraduate students taking classes from the physics curriculum (Nuclear Physics, Atomic Physics, and Radiation Biophysics). Our goal is to develop a set of radiation laboratories, which will strengthen the curriculum of physics, chemistry, geology, biology, and environmental science at WKU. The teaching and research activities are integrated into real-world projects and hands-on activities to engage students. The proposed experiments and their relevance to the modern status of physical science are discussed.

IBPRO - A Novel Short-Duration Teaching Course in Advanced Physics and Biology Underlying Cancer Radiotherapy.

PubMed

Joiner, Michael C; Tracey, Monica W; Kacin, Sara E; Burmeister, Jay W

2017-06-01

This article provides a summary and status report of the ongoing advanced education program IBPRO - Integrated course in Biology and Physics of Radiation Oncology. IBPRO is a five-year program funded by NCI. It addresses the recognized deficiency in the number of mentors available who have the required knowledge and skill to provide the teaching and training that is required for future radiation oncologists and researchers in radiation sciences. Each year, IBPRO brings together 50 attendees typically at assistant professor level and upwards, who are already qualified/certified radiation oncologists, medical physicists or biologists. These attendees receive keynote lectures and activities based on active learning strategies, merging together the clinical, biological and physics underpinnings of radiation oncology, at the forefront of the field. This experience is aimed at increasing collaborations, raising the level and amount of basic and applied research undertaken in radiation oncology, and enabling attendees to confidently become involved in the future teaching and training of researchers and radiation oncologists.

IBPRO – a novel short-duration teaching course in advanced physics and biology underlying cancer radiotherapy

PubMed Central

Joiner, Michael C.; Tracey, Monica W.; Kacin, Sara E.; Burmeister, Jay W.

2017-01-01

This article provides a summary and status report of the ongoing advanced education program IBPRO – Integrated course in Biology and Physics of Radiation Oncology. IBPRO is a five-year program funded by NCI. It addresses the recognized deficiency in the number of mentors available who have the required knowledge and skill to provide the teaching and training that is required for future radiation oncologists and researchers in radiation sciences. Each year, IBPRO brings together 50 attendees typically at assistant professor level and upwards, who are already qualified/certified radiation oncologists, medical physicists or biologists. These attendees receive keynote lectures and activities based on active learning strategies, merging together the clinical, biological and physics underpinnings of radiation oncology, at the forefront of the field. This experience is aimed at increasing collaborations, raising the level and amount of basic and applied research undertaken in radiation oncology, and enabling attendees to confidently become involved in the future teaching and training of researchers and radiation oncologists. PMID:28328309

Measurement of energy transitions for the decay radiations of 75Ge and 69Ge in a high purity germanium detector

NASA Astrophysics Data System (ADS)

Aydın, Güral; Usta, Metin; Oktay, Adem

2018-06-01

Photoactivation experiments have a wide range of application areas in nuclear, particle physics, and medical physics such as measuring energy levels and half-lifes of nuclei, experiments for understanding imaging methods in medicine, isotope production for patient treatment, radiation security and transportation, radiation therapy, and astrophysics processes. In this study, some energy transition values of the decay radiations of 75Ge and 69Ge, which are the products of photonuclear reactions (γ, n) with germanium isotopes (75Ge and 69Ge), were measured. The gamma spectrum as a result of atomic transitions were analysed by using a high purity semiconductor germanium detector and the energy transition values which are presented here were compared with the ones which are the best in literature. It was observed that the results presented are in agreement with literature in error range and some results have better precisions.

CERN@school: demonstrating physics with the Timepix detector

NASA Astrophysics Data System (ADS)

Whyntie, T.; Bithray, H.; Cook, J.; Coupe, A.; Eddy, D.; Fickling, R. L.; McKenna, J.; Parker, B.; Paul, A.; Shearer, N.

2015-10-01

This article shows how the Timepix hybrid silicon pixel detector, developed by the Medipix2 Collaboration, can be used by students and teachers alike to demonstrate some key aspects of any well-rounded physics curriculum with CERN@school. After an overview of the programme, the detector's capabilities for measuring and visualising ionising radiation are examined. The classification of clusters - groups of adjacent pixels - is discussed with respect to identifying the different types of particles. Three demonstration experiments - background radiation measurements, radiation profiles and the attenuation of radiation - are described; these can used as part of lessons or as inspiration for independent research projects. Results for exemplar data-sets are presented for reference, as well as details of ongoing research projects inspired by these experiments. Interested readers are encouraged to join the CERN@school Collaboration and so contribute to achieving the programme's aim of inspiring the next generation of scientists and engineers.

Common Problems with Pyrometry at Shock Physics Experiments and How to Avoid Them

NASA Astrophysics Data System (ADS)

Seifter, Achim; Obst, Andrew; Holtkamp, David

2007-06-01

Temperature is not only one of the most prominent parameters in shock physics experiments but also very hard to determine experimentally. Only a few techniques are available because of difficulties due to the short timescale and often very low temperatures. Pyrometry is the most portable of these techniques but has to deal with some problems which give rise to uncertainties. Only if the experiment is designed very carefully some of these difficulties like background radiation from high explosive burn products, muzzle flash or laser light can be avoided. Other problems like spatial temperature non-uniformities or thermal radiation from a transparent anvil are inherent to the experiment and cannot be avoided. By choosing the proper spectral range covered by the pyrometer and fitting the obtained spectral radiance traces with appropriate models meaningful results can be obtained. In this paper we will describe the most important points to be taken into account when designing the experiment, present considerations for choosing the wavelength range of the pyrometer and show data where spatial non uniformities or radiation from hot anvils occurred and temperature data could still be obtained.

Physical-mathematical model of optical radiation interaction with biological tissues

NASA Astrophysics Data System (ADS)

Kozlovska, Tetyana I.; Kolisnik, Peter F.; Zlepko, Sergey M.; Titova, Natalia V.; Pavlov, Volodymyr S.; Wójcik, Waldemar; Omiotek, Zbigniew; Kozhambardiyeva, Miergul; Zhanpeisova, Aizhan

2017-08-01

Remote photoplethysmography (PPG) imaging is an optical technique to remotely assess the local coetaneous microcirculation. In this paper, we present a model and supporting experiments confirming the contribution of skin inhomogeneity to the morphology of PPG waveforms. The physical-mathematical model of distribution of optical radiation in biological tissues was developed. It allows determining the change of intensity of optical radiation depending on such parameters as installation angle of the sensor, biological tissue thickness and the wavelength. We obtained graphics which represent changes of the optical radiation intensity that is registered by photodetector depending on installation angle of the sensor, biological tissue thickness and the extinction coefficient.

Health physics measurement of Princeton Tokamaks, 1977-1987.

PubMed

Stencel, J R; Gilbert, J D; Couch, J G; Griesbach, O A; Fennimore, J J; Greco, J M

1989-06-01

The Princeton Plasma Physics Laboratory (PPPL) began fusion experiments in 1951. In the early years, the major health physics concerns were associated with x radiation produced by energetic electrons in the plasma. Within the past year, neutron and 3H production from 2H-2H (represented hereafter as D-D) reactions has increased significantly on the larger fusion devices. Tritium retention noted in graphite tiles underscores the significance of material selection in present and future 3H-fueled fusion devices. This paper reports on operational health physics radiation measurements made on various PPPL machines over the past 10 y.

Nuclear physics experiments with low cost instrumentation

NASA Astrophysics Data System (ADS)

Oliveira Bastos, Rodrigo; Adelar Boff, Cleber; Melquiades, Fábio Luiz

2016-11-01

One of the difficulties in modern physics teaching is the limited availability of experimental activities. This is particularly true for teaching nuclear physics in high school or college. The activities suggested in the literature generally symbolise real phenomenon, using simulations. It happens because the experimental practices mostly include some kind of expensive radiation detector and an ionising radiation source that requires special care for handling and storage, being subject to a highly bureaucratic regulation in some countries. This study overcomes these difficulties and proposes three nuclear physics experiments using a low-cost ion chamber which construction is explained: the measurement of 222Rn progeny collected from the indoor air; the measurement of the range of alpha particles emitted by the 232Th progeny, present in lantern mantles and in thoriated welding rods, and by the air filter containing 222Rn progeny; and the measurement of 220Rn half-life collected from the emanation of the lantern mantles. This paper presents the experimental procedures and the expected results, indicating that the experiments may provide support for nuclear physics classes. These practices may outreach wide access to either college or high-school didactic laboratories, and the apparatus has the potential for the development of new teaching activities for nuclear physics.

Cosmic Balloons

ERIC Educational Resources Information Center

El Abed, Mohamed

2014-01-01

A team of French high-school students sent a weather balloon into the upper atmosphere to recreate Viktor Hess's historical experiment that demonstrated the existence of ionizing radiation from the sky--later called cosmic radiation. This discovery earned him the Nobel Prize for Physics in 1936.

Inertial confinement fusion ablator physics experiments on Saturn and Nova

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olson, R.E.; Porter, J.L.; Chandler, G.A.

1997-05-01

The Saturn pulsed power accelerator [R. B. Spielman {ital et al.}, in {ital Proceedings of the 2nd International Conference on Dense} Z-{ital pinches}, Laguna Beach, CA, 1989, edited by N. R. Pereira, J. Davis, and N. Rostoker (American Institute of Physics, New York, 1989), p. 3] at Sandia National Laboratories (SNL) and the Nova laser [J. T. Hunt and D. R. Speck, Opt. Eng. {bold 28}, 461 (1989)] at Lawrence Livermore National Laboratory (LLNL) have been used to explore techniques for studying the behavior of ablator material in x-ray radiation environments comparable in magnitude, spectrum, and duration to those thatmore » would be experienced in National Ignition Facility (NIF) hohlraums [J. D. Lindl, Phys. Plasmas {bold 2}, 3933 (1995)]. The large x-ray outputs available from the Saturn pulsed-power-driven z pinch have enabled us to drive hohlraums of full NIF ignition scale size at radiation temperatures and time scales comparable to those required for the low-power foot pulse of an ignition capsule. The high-intensity drives available in the Nova laser have allowed us to study capsule ablator physics in smaller-scale hohlraums at radiation temperatures and time scales relevant to the peak power pulse for an ignition capsule. Taken together, these experiments have pointed the way to possible techniques for testing radiation-hydrodynamics code predictions of radiation flow, opacity, equation of state, and ablator shock velocity over the range of radiation environments that will be encountered in a NIF hohlraum. {copyright} {ital 1997 American Institute of Physics.}« less

New Worlds in Astroparticle Physics: Proceedings of the Fifth International Workshop

NASA Astrophysics Data System (ADS)

Mourão, Ana M.; Pimenta, Mário; Potting, Robertus; Sá, Paulo M.

Preface -- Group photo -- pt. 1. Overviews in astroparticle physics. An overview of the status of work on ultra high energy cosmic rays / A. A. Watson. Gravitational waves from compact sources / K. D. Kokkotas and N. Stergioulas. Neutrino physics and astrophysics / E. Fernandez. Black holes and fundamental physics / J. P. S. Lemos -- pt. 2. Contributions. Cosmic ray physics. Phenomenology of cosmic ray air showers / M. T. Dova. First results from the MAGIC experiment / A. de Angelis. How to select UHECR in EUSO - the trigger system / P. Assis. Pressure and temperature dependence of the primary scintillation in air / M. Fraga ... [et al.]. Overview of the GLAST physics / N. Giglietto ... [et al.]. Velocity and charge reconstruction with the AMS/RICH detector / L. Arruda ... [et al.]. Isotope separation with the RICH detector of the AMS experiment / L. Arruda ... [et al.]. Gravitational waves and compact sources. Gravitational radiation from 3D collapse to rotating black holes / L. Baiotti ... [et al.]. The role of differential rotation in the evolution of the r-mode instability / P. M. Sá and B. Tomé. Analytical r-mode solution with gravitational radiation reaction force / Ó. J. C. Dias and P. M. Sá. Space radiation: effects and monitoring. Particles from the sun / D. Maia. Simulations of space radiation monitors / B. Tomé. GEANT4 detector simulations: radiation interaction simulations for the high-energy astrophysics experiments EUSO and AMS / P. Goncalves. Software for radiological risk assessment in space missions / A. Trindade, P. Rodrigues. Neutrino physics. Results from K2K / S. Andringa. SNO: salt phase results and NCD phase status / J. Maneira. The ICARUS experiment / S. Navas-Concha. Cosmological parameters measurements. High redshift supernova surveys / S. Fabbro. SNFactory: nearby supernova factory / P. Antilogus. A polarized galactic emission mapping experiment at 5-10 GHz / D. Barbosa ... [et al.]. Galaxy clusters as probes of dark energy / P. T. P. Viana. Black hole physics. Acoustic black holes / V. Cardoso. Superradiant instabilities in black hole systems / Á. J. C. Dias ... [et al.]. Microscopic black hole detection in UHECR: the double bang signature / M. Paulos. Generalized uncertainty principle and holography / F. Scardiali and R. Casadio. Testing covariant entropy bounds / S. Gao and J. P. S. Lemos. Dark matter and dark energy. Dark energy - dark matter unification: generalized Chaplygin gas model / O. Bertolami. Cosmology and spacetime symmetries / R. Lehnert. Scalar field models: from the pioneer anomaly to astrophysical constraints / J. Páramos. Braneworlds, conformal fields and dark energy / R. Neves. Sun and stars as cosmological tools: probing supersymmetric dark matter / I. Lopes. ZEPLIN III: xenon detector for WIMP searches / H. Araújo. Dark matter detectability with Čerenkov telescopes -- List of participants.

Workshop summary. Biomedical and Space-Related Research with Heavy Ions at the BEVALAC

NASA Technical Reports Server (NTRS)

Schimmerling, W.; Curtis, S. B.

1989-01-01

The authors provide an overview of papers presented at a workshop on Biomedical and Space-Related Research with Heavy Ions at the BEVALAC at Lawrence Berkeley Laboratory. Goals of the meeting were to determine the critical experiments using heavy ions as probes in radiation physics, radiation chemistry, macromolecular and cellular biology, evolution science, basic neurophysiology, and medical therapies; how beam lines and facilities at Lawrence Berkeley Laboratory can be improved for these experiments; and implications in priorities and funding for national policy. Workshop topics included physics and facilities, cellular and molecular biology, tissue radiobiology, and the future of heavy ion research.

Development of Thermal Radiation Experiments Kit Based on Data Logger for Physics Learning Media

NASA Astrophysics Data System (ADS)

Permana, H.; Iswanto, B. H.

2018-04-01

Thermal Radiation Experiments Kit (TREK) based on data logger for physics learning media was developed. TREK will be used as a learning medium on the subject of Temperature and Heat to explain the concept of emissivity of a material in grade XI so that it can add variations of experiments which are commonly done such as thermal expansion, transfer of thermal energy (conduction, convection, and radiation), and specific heat capacity. DHT11 sensor is used to measure temperature and microcontroller Arduino-uno used as data logger. The object tested are in the form of coated glass thin films and aluminum with different colors. TREK comes with a user manual and student worksheet (LKS) to make it easier for teachers and students to use. TREK was developed using the ADDIE Development Model (Analyze, Design, Development, Implementation, and Evaluation). And validated by experts, physics teachers, and students. Validation instrument is a questionnaire with a five-item Likert response scale with reviewed aspect coverage: appropriate content and concepts, design, and user friendly. The results showed that TREK was excellent (experts 88.13%, science teachers 95.68%, and students 85.77%).

Experiments with a Regional Vector-Vorticity Model, and Comparison with Other Models

NASA Astrophysics Data System (ADS)

Konor, C. S.; Dazlich, D. A.; Jung, J.; Randall, D. A.

2017-12-01

The Vector-Vorticity Model (VVM) is an anelastic model with a unique dynamical core that predicts the three-dimensional vorticity instead of the three-dimensional momentum. The VVM is used in the CRMs of the Global Quasi-3D Multiscale Modeling Framework, which is discussed by Joon-Hee Jung and collaborators elsewhere in this session. We are updating the physics package of the VVM, replacing it with the physics package of the System for Atmosphere Modeling (SAM). The new physics package includes a double-moment microphysics, Mellor-Yamada turbulence, Monin-Obukov surface fluxes, and the RRTMG radiation parameterization. We briefly describe the VVM and show results from standard test cases, including TWP-ICE. We compare the results with those obtained using the earlier physics. We also show results from experiments on convection aggregation in radiative-convective equilibrium, and compare with those obtained using both SAM and the Regional Atmospheric Modeling System (RAMS).

Radiative sky cooling: fundamental physics, materials, structures, and applications

NASA Astrophysics Data System (ADS)

Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang; Alam, Muhammad Ashraful; Bermel, Peter

2017-07-01

Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, such as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.

Basic Nuclear Physics.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

Basic concepts of nuclear structures, radiation, nuclear reactions, and health physics are presented in this text, prepared for naval officers. Applications to the area of nuclear power are described in connection with pressurized water reactors, experimental boiling water reactors, homogeneous reactor experiments, and experimental breeder…

Analytical study of the heat loss attenuation by clothing on thermal manikins under radiative heat loads.

PubMed

Den Hartog, Emiel A; Havenith, George

2010-01-01

For wearers of protective clothing in radiation environments there are no quantitative guidelines available for the effect of a radiative heat load on heat exchange. Under the European Union funded project ThermProtect an analytical effort was defined to address the issue of radiative heat load while wearing protective clothing. As within the ThermProtect project much information has become available from thermal manikin experiments in thermal radiation environments, these sets of experimental data are used to verify the analytical approach. The analytical approach provided a good prediction of the heat loss in the manikin experiments, 95% of the variance was explained by the model. The model has not yet been validated at high radiative heat loads and neglects some physical properties of the radiation emissivity. Still, the analytical approach provides a pragmatic approach and may be useful for practical implementation in protective clothing standards for moderate thermal radiation environments.

Space plasma physics at the Applied Physics Laboratory over the past half-century

NASA Technical Reports Server (NTRS)

Potemra, Thomas A.

1992-01-01

An overview is given of space-plasma experiments conducted at the Applied Physics Laboratory (APL) at Johns Hopkins University including observational campaigns and the instrumentation developed. Specific space-plasma experiments discussed include the study of the radiation environment in the Van Allen radiation belt with solid-state proton detectors. Also described are the 5E-1 satellites which acquired particle and magnetic-field data from earth orbit. The Triad satellite and its magnetometer system were developed for high-resolution studies of the earth's magnetic field, and APL contributions to NASA's Interplanetary Monitoring Platforms are listed. The review mentions the International Ultraviolet Explorer, the Atmosphere Explorer mission, and the Active Magnetic Particle Tracer Explorers mission. Other recent programs reviewed include a high-latitude satellite, contributions to the Voyager mission, and radar studies of space plasmas.

Skylab experiments. Volume 5: Astronomy and space physics. [Skylab observations of galactic radiation, solar energy, and interplanetary composition for high school level education

NASA Technical Reports Server (NTRS)

1973-01-01

The astronomy and space physics investigations conducted in the Skylab program include over 20 experiments in four categories to explore space phenomena that cannot be observed from earth. The categories of space research are as follows: (1) phenomena within the solar system, such as the effect of solar energy on Earth's atmosphere, the composition of interplanetary space, the possibility of an inner planet, and the X-ray radiation from Jupiter, (2) analysis of energetic particles such as cosmic rays and neutrons in the near-earth space, (3) stellar and galactic astronomy, and (4) self-induced environment surrounding the Skylab spacecraft.

Crucial Experiments in Quantum Physics.

ERIC Educational Resources Information Center

Trigg, George L.

The six experiments included in this monography are titled Blackbody Radiation, Collision of Electrons with Atoms, The Photoelectric Effect, Magnetic Properties of Atoms, The Scattering of X-Rays, and Diffraction of Electrons by a Crystal Lattice. The discussion provides historical background by giving description of the original experiments and…

US plant and radiation dosimetry experiments flown on the Soviet satellite Cosmos 1129

NASA Technical Reports Server (NTRS)

Heinrich, M. R. (Editor); Souza, K. A. (Editor)

1981-01-01

Experiments included: 30 young male Wistar SPF rats used for wide range physiological studies; experiments with plants, fungi, insects, and mammalian tissue cultures; radiation physics experiments; a heat convection study; a rat embryology experiment in which an attempt was made to breed 2 male and 5 female rats during the flight; and fertile quail eggs used to determine the effects of spaceflight on avian embryogenesis. Specimens for US experiments were initially prepared at the recovery site or in Moscow and transferred to US laboratories for complete analyses. An overview of the mission focusing on preflight, on orbit, and postflight activities pertinent to the fourteen US experiments aboard Cosmos 1129 is presented.

10 CFR 33.15 - Requirements for the issuance of a Type C specific license of broad scope.

Code of Federal Regulations, 2011 CFR

2011-01-01

... bachelor level, or equivalent training and experience, in the physical or biological sciences or in..., radiation detection instrumentation, and biological hazards of exposure to radiation appropriate to the type... controls and provisions relating to procurement of byproduct material, procedures, record keeping, material...

Review of Nuclear Physics Experiments for Space Radiation

NASA Technical Reports Server (NTRS)

Norbury, John W.; Miller, Jack; Adamczyk, Anne M.; Heilbronn, Lawrence H.; Townsend, Lawrence W.; Blattnig, Steve R.; Norman, Ryan B.; Guetersloh, Stephen B.; Zeitlin, Cary J.

2011-01-01

Human space flight requires protecting astronauts from the harmful effects of space radiation. The availability of measured nuclear cross section data needed for these studies is reviewed in the present paper. The energy range of interest for radiation protection is approximately 100 MeV/n to 10 GeV/n. The majority of data are for projectile fragmentation partial and total cross sections, including both charge changing and isotopic cross sections. The cross section data are organized into categories which include charge changing, elemental, isotopic for total, single and double differential with respect to momentum, energy and angle. Gaps in the data relevant to space radiation protection are discussed and recommendations for future experiments are made.

Computer Model Of Fragmentation Of Atomic Nuclei

NASA Technical Reports Server (NTRS)

Wilson, John W.; Townsend, Lawrence W.; Tripathi, Ram K.; Norbury, John W.; KHAN FERDOUS; Badavi, Francis F.

1995-01-01

High Charge and Energy Semiempirical Nuclear Fragmentation Model (HZEFRG1) computer program developed to be computationally efficient, user-friendly, physics-based program for generating data bases on fragmentation of atomic nuclei. Data bases generated used in calculations pertaining to such radiation-transport applications as shielding against radiation in outer space, radiation dosimetry in outer space, cancer therapy in laboratories with beams of heavy ions, and simulation studies for designing detectors for experiments in nuclear physics. Provides cross sections for production of individual elements and isotopes in breakups of high-energy heavy ions by combined nuclear and Coulomb fields of interacting nuclei. Written in ANSI FORTRAN 77.

Radiative sky cooling: fundamental physics, materials, structures, and applications

DOE PAGES

Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang; ...

2017-07-29

Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, suchmore » as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.« less

Radiative sky cooling: fundamental physics, materials, structures, and applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang

Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, suchmore » as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.« less

Development of a Space Radiation Monte-Carlo Computer Simulation Based on the FLUKE and Root Codes

NASA Technical Reports Server (NTRS)

Pinsky, L. S.; Wilson, T. L.; Ferrari, A.; Sala, Paola; Carminati, F.; Brun, R.

2001-01-01

The radiation environment in space is a complex problem to model. Trying to extrapolate the projections of that environment into all areas of the internal spacecraft geometry is even more daunting. With the support of our CERN colleagues, our research group in Houston is embarking on a project to develop a radiation transport tool that is tailored to the problem of taking the external radiation flux incident on any particular spacecraft and simulating the evolution of that flux through a geometrically accurate model of the spacecraft material. The output will be a prediction of the detailed nature of the resulting internal radiation environment within the spacecraft as well as its secondary albedo. Beyond doing the physics transport of the incident flux, the software tool we are developing will provide a self-contained stand-alone object-oriented analysis and visualization infrastructure. It will also include a graphical user interface and a set of input tools to facilitate the simulation of space missions in terms of nominal radiation models and mission trajectory profiles. The goal of this project is to produce a code that is considerably more accurate and user-friendly than existing Monte-Carlo-based tools for the evaluation of the space radiation environment. Furthermore, the code will be an essential complement to the currently existing analytic codes in the BRYNTRN/HZETRN family for the evaluation of radiation shielding. The code will be directly applicable to the simulation of environments in low earth orbit, on the lunar surface, on planetary surfaces (including the Earth) and in the interplanetary medium such as on a transit to Mars (and even in the interstellar medium). The software will include modules whose underlying physics base can continue to be enhanced and updated for physics content, as future data become available beyond the timeframe of the initial development now foreseen. This future maintenance will be available from the authors of FLUKA as part of their continuing efforts to support the users of the FLUKA code within the particle physics community. In keeping with the spirit of developing an evolving physics code, we are planning as part of this project, to participate in the efforts to validate the core FLUKA physics in ground-based accelerator test runs. The emphasis of these test runs will be the physics of greatest interest in the simulation of the space radiation environment. Such a tool will be of great value to planners, designers and operators of future space missions, as well as for the design of the vehicles and habitats to be used on such missions. It will also be of aid to future experiments of various kinds that may be affected at some level by the ambient radiation environment, or in the analysis of hybrid experiment designs that have been discussed for space-based astronomy and astrophysics. The tool will be of value to the Life Sciences personnel involved in the prediction and measurement of radiation doses experienced by the crewmembers on such missions. In addition, the tool will be of great use to the planners of experiments to measure and evaluate the space radiation environment itself. It can likewise be useful in the analysis of safe havens, hazard migration plans, and NASA's call for new research in composites and to NASA engineers modeling the radiation exposure of electronic circuits. This code will provide an important complimentary check on the predictions of analytic codes such as BRYNTRN/HZETRN that are presently used for many similar applications, and which have shortcomings that are more easily overcome with Monte Carlo type simulations. Finally, it is acknowledged that there are similar efforts based around the use of the GEANT4 Monte-Carlo transport code currently under development at CERN. It is our intention to make our software modular and sufficiently flexible to allow the parallel use of either FLUKA or GEANT4 as the physics transport engine.

Fine-Structure Measurements of Oxygen A Band Absorbance for Estimating the Thermodynamic Average Temperature of the Earth's Atmosphere: An Experiment in Physical and Environmental Chemistry

ERIC Educational Resources Information Center

Myrick, M. L.; Greer, A. E.; Nieuwland, A.; Priore, R. J.; Scaffidi, J.; Andreatta, Daniele; Colavita, Paula

2006-01-01

The experiment describe the measures of the A band transitions of atmospheric oxygen, a rich series of rotation-electronic absorption lines falling in the deep red portion of the optical spectrum and clearly visible owing to attenuation of solar radiation. It combines pure physical chemistry with analytical and environmental science and provides a…

Experiments on Dust Grain Charging

NASA Technical Reports Server (NTRS)

Abbas, M. N.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; West, E. A.

2004-01-01

Dust particles in various astrophysical environments are charged by a variety of mechanisms generally involving collisional processes with other charged particles and photoelectric emission with UV radiation from nearby sources. The sign and the magnitude of the particle charge are determined by the competition between the charging processes by UV radiation and collisions with charged particles. Knowledge of the particle charges and equilibrium potentials is important for understanding of a number of physical processes. The charge of a dust grain is thus a fundamental parameter that influences the physics of dusty plasmas, processes in the interplanetary medium and interstellar medium, interstellar dust clouds, planetary rings, cometary and outer atmospheres of planets etc. In this paper we present some results of experiments on charging of dust grains carried out on a laboratory facility capable levitating micron size dust grains in an electrodynamic balance in simulated space environments. The charging/discharging experiments were carried out by exposing the dust grains to energetic electron beams and UV radiation. Photoelectric efficiencies and yields of micron size dust grains of SiO2, and lunar simulates obtained from NASA-JSC will be presented.

Comparison of resistive MHD simulations and experimental CHI discharges in NSTX

NASA Astrophysics Data System (ADS)

Hooper, E. B.; Sovinec, C. R.; Raman, R.; Fatima, F.

2013-10-01

Resistive MHD simulations using NIMROD simulate CHI discharges for NSTX startup plasmas. Quantitative comparison with experiment ensures that the simulation physics includes a minimal physics set needed to extend the simulations to new experiments, e.g. NSTX-U. Important are time-varying vacuum magnetic field, ohmic heating, thermal transport, impurity radiation, and spatially-varying plasma parameters including density. Equilibria are compared with experimental injector currents, voltages and parameters including toroidal current, photographs of emitted light and measurements of midplane temperature profiles, radiation and surface heating. Initial results demonstrate that adjusting impurity radiation and cross-field transport yields temperatures and injected-current channel widths similar to experiment. These determine the plasma resistance, feeding back to the impedance on the injector power supply. Work performed under the auspices of the U.S. Department of Energy under contracts DE-AC52-07NA27344 at LLNL and DE-AC02-09CH11466 at PPPL, and grants DE-FC02-05ER54813 at PSI Center (U. Wisc.) and DOE-FG02-12ER55115 (at Princeton U.).

Physical Processes and Applications of the Monte Carlo Radiative Energy Deposition (MRED) Code

NASA Astrophysics Data System (ADS)

Reed, Robert A.; Weller, Robert A.; Mendenhall, Marcus H.; Fleetwood, Daniel M.; Warren, Kevin M.; Sierawski, Brian D.; King, Michael P.; Schrimpf, Ronald D.; Auden, Elizabeth C.

2015-08-01

MRED is a Python-language scriptable computer application that simulates radiation transport. It is the computational engine for the on-line tool CRÈME-MC. MRED is based on c++ code from Geant4 with additional Fortran components to simulate electron transport and nuclear reactions with high precision. We provide a detailed description of the structure of MRED and the implementation of the simulation of physical processes used to simulate radiation effects in electronic devices and circuits. Extensive discussion and references are provided that illustrate the validation of models used to implement specific simulations of relevant physical processes. Several applications of MRED are summarized that demonstrate its ability to predict and describe basic physical phenomena associated with irradiation of electronic circuits and devices. These include effects from single particle radiation (including both direct ionization and indirect ionization effects), dose enhancement effects, and displacement damage effects. MRED simulations have also helped to identify new single event upset mechanisms not previously observed by experiment, but since confirmed, including upsets due to muons and energetic electrons.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, S.R.

A comprehensive evaluation was conducted of the radiation protection practices and programs at prototype LMFBRs with long operational experience. Installations evaluated were the Fast Flux Test Facility (FFTF), Richland, Washington; Experimental Breeder Reactor II (EBR-II), Idaho Falls, Idaho; Prototype Fast Reactor (PFR) Dounreay, Scotland; Phenix, Marcoule, France; and Kompakte Natriumgekuhlte Kernreak Toranlange (KNK II), Karlsruhe, Federal Republic of Germany. The evaluation included external and internal exposure control, respiratory protection procedures, radiation surveillance practices, radioactive waste management, and engineering controls for confining radiation contamination. The theory, design, and operating experience at LMFBRs is described. Aspects of LMFBR health physics different frommore » the LWR experience in the United States are identified. Suggestions are made for modifications to the NRC Standard Review Plan based on the differences.« less

US plant and radiation dosimetry experiments flown on the soviet satellite COSMOS 1129. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heinrich, M.R.; Souza, K.A.

1981-05-01

Experiments included: 30 young male Wistar SPF rats used for wide range physiological studies Kosmos Satellites experiments with plants, fungi, insects, and mammalian tissue cultures; radiation physics experiments; a heat convection study; a rat embryology experiment in which an attempt was made to breed 2 male and 5 female rats during the flight; and fertile quail eggs used to determine the effects of spaceflight on avian embryogenesis. Specimens for US experiments were initially prepared at the recovery site or in Moscow and transferred to US laboratories for complete analyses. An overview of the mission focusing on preflight, on orbit, andmore » postflight activities pertinent to the fourteen US experiments aboard Cosmos 1129 is presented.« less

A Computerized Library and Evaluation System for Integral Neutron Experiments.

ERIC Educational Resources Information Center

Hampel, Viktor E.; And Others

A computerized library of references to integral neutron experiments has been developed at the Lawrence Radiation Laboratory at Livermore. This library serves as a data base for the systematic retrieval of documents describing diverse critical and bulk nuclear experiments. The evaluation and reduction of the physical parameters of the experiments…

An investigation of the role of current and future remote sensing data systems in numerical meteorology

NASA Technical Reports Server (NTRS)

Diak, George R.; Smith, William L.

1992-01-01

A flexible system for performing observing system simulation experiments which made contributions to meteorology across all elements of the observing system simulation experiment (OSSE) components was developed. Future work will seek better understanding of the links between satellite-measured radiation and radiative transfer in the clear, cloudy and precipitating atmosphere and investigate how that understanding might be applied to improve the depiction of the initial state and the treatment of physical processes in forecast models of the atmosphere.

Learning Activity Package, Physical Science. LAP Numbers 8, 9, 10, and 11.

ERIC Educational Resources Information Center

Williams, G. J.

These four units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover nuclear reactions, alpha and beta particles, atomic radiation, medical use of nuclear energy, fission, fusion, simple machines, Newton's laws of motion, electricity, currents, electromagnetism, Oersted's experiment, sound, light,…

Mitigated FPGA design of multi-gigabit transceivers for application in high radiation environments of High Energy Physics experiments

DOE PAGES

Brusati, M.; Camplani, A.; Cannon, M.; ...

2017-02-20

SRAM-ba8ed Field Programmable Gate Array (FPGA) logic devices arc very attractive in applications where high data throughput is needed, such as the latest generation of High Energy Physics (HEP) experiments. FPGAs have been rarely used in such experiments because of their sensitivity to radiation. The present paper proposes a mitigation approach applied to commercial FPGA devices to meet the reliability requirements for the front-end electronics of the Liquid Argon (LAr) electromagnetic calorimeter of the ATLAS experiment, located at CERN. Particular attention will be devoted to define a proper mitigation scheme of the multi-gigabit transceivers embedded in the FPGA, which ismore » a critical part of the LAr data acquisition chain. A demonstrator board is being developed to validate the proposed methodology. :!\\litigation techniques such as Triple Modular Redundancy (T:t\\IR) and scrubbing will be used to increase the robustness of the design and to maximize the fault tolerance from Single-Event Upsets (SEUs).« less

Comprehensive Experiments on Subcritical Assemblies of Cascade Reactor Systems

NASA Astrophysics Data System (ADS)

Zavyalov, N. V.; Il'kaev, R. I.; Kolesov, V. F.; Ivanin, I. A.; Zhitnik, A. K.; Kuvshinov, M. I.; Nefedov, Yu. Ya.; Punin, V. T.; Tel'nov, A. V.; Khoruzhi, V. Kh.

2017-12-01

Cascade reactors attract particular attention because of their capability of improving the parameters of pulsed reactors and achieving the feasibility of electronuclear facilities. The paper presents the results of three series of experiments on uranium-neptunium cascade assemblies at the Institute of Nuclear and Radiation Physics of the All-Russian Research Institute of Experimental Physics conducted in 2003-2004. The experiments confirmed theoretical conclusions on positive properties of cascade blankets and effectiveness of using neptunium-237 as a means of creating a one-sided connection between the sections.

Space Radiation and Manned Mission: Interface Between Physics and Biology

NASA Astrophysics Data System (ADS)

Hei, Tom

2012-07-01

The natural radiation environment in space consists of a mixed field of high energy protons, heavy ions, electrons and alpha particles. Interplanetary travel to the International Space Station and any planned establishment of satellite colonies on other solar system implies radiation exposure to the crew and is a major concern to space agencies. With shielding, the radiation exposure level in manned space missions is likely to be chronic, low dose irradiation. Traditionally, our knowledge of biological effects of cosmic radiation in deep space is almost exclusively derived from ground-based accelerator experiments with heavy ions in animal or in vitro models. Radiobiological effects of low doses of ionizing radiation are subjected to modulations by various parameters including bystander effects, adaptive response, genomic instability and genetic susceptibility of the exposed individuals. Radiation dosimetry and modeling will provide conformational input in areas where data are difficult to acquire experimentally. However, modeling is only as good as the quality of input data. This lecture will discuss the interdependent nature of physics and biology in assessing the radiobiological response to space radiation.

Gaseous Electron Multiplier (GEM) Detectors

NASA Astrophysics Data System (ADS)

Gnanvo, Kondo

2017-09-01

Gaseous detectors have played a pivotal role as tracking devices in the field of particle physics experiments for the last fifty years. Recent advances in photolithography and micro processing techniques have enabled the transition from Multi Wire Proportional Chambers (MWPCs) and Drift Chambers to a new family of gaseous detectors refer to as Micro Pattern Gaseous Detectors (MPGDs). MPGDs combine the basic gas amplification principle with micro-structure printed circuits to provide detectors with excellent spatial and time resolution, high rate capability, low material budget and high radiation tolerance. Gas Electron Multiplier (GEMs) is a well-established MPGD technology invented by F. Sauli at CERN in 1997 and deployed various high energy physics (HEP) and nuclear NP experiment for tracking systems of current and future NP experiments. GEM detector combines an exceptional high rate capability (1 MHz / mm2) and robustness against harsh radiation environment with excellent position and timing resolution performances. Recent breakthroughs over the past decade have allowed the possibility for large area GEMs, making them cost effective and high-performance detector candidates to play pivotal role in current and future particle physics experiments. After a brief introduction of the basic principle of GEM technology, I will give a brief overview of the GEM detectors used in particle physics experiments over the past decades and especially in the NP community at Thomas Jefferson National Laboratory (JLab) and Brookhaven National Laboratory (BNL). I will follow by a review of state of the art of the new GEM development for the next generation of colliders such as Electron Ion Collider (EIC) or High Luminosity LHC and future Nuclear Physics experiments. I will conclude with a presentation of the CERN-based RD51 collaboration established in 2008 and its major achievements regarding technological developments and applications of MPGDs.

Boundary layer aerosol size distribution, mass concentration and mineralogical composition in Morocco and at Cape Verde Islands during SAMUM I-II

NASA Astrophysics Data System (ADS)

Kandler, K.; Lieke, K.

2009-04-01

The Saharan Mineral Dust Experiment (SAMUM) is dedicated to the understanding of the radiative effects of mineral dust. Two major field experiments were performed: A first joint field campaign took place at Ouarzazate and near Zagora, southern Morocco, from May 13 to June 7, 2006. Aircraft and ground based measurements of aerosol physical and chemical properties were carried out to collect a data set of surface and atmospheric columnar information within a major dust source. This data set combined with satellite data provides the base of the first thorough columnar radiative closure tests in Saharan dust. A second field experiment was conducted during January-February 2008, in the Cape Verde Islands region, where about 300 Tg of mineral dust are transported annually from Western Africa across the Atlantic towards the Caribbean Sea and the Amazon basin. Along its transport path, the mineral dust is expected to influence significantly the radiation budget - by direct and indirect effects - of the subtropical North Atlantic. We are lacking a radiative closure in the Saharan air plume. One focus of the investigation within the trade wind region is the spatial distribution of mixed dust/biomass/sea salt aerosol and their physical and chemical properties, especially with regard to radiative effects. We report on measurements of size distributions, mass concentrations and mineralogical composition conducted at the Zagora (Morocco) and Praia (Cape Verde islands) ground stations. The aerosol size distribution was measured from 20 nm to 500

Beam-plasma coupling physics in support of active experiments

NASA Astrophysics Data System (ADS)

Yakymenko, K.; Delzanno, G. L.; Roytershteyn, V.

2017-12-01

The recent development of compact relativistic accelerators might open up a new era of active experiments in space, driven by important scientific and national security applications. Examples include using electron beams to trace magnetic field lines and establish causality between physical processes occurring in the magnetosphere and those in the ionosphere. Another example is the use of electron beams to trigger waves in the near-Earth environment. Waves could induce pitch-angle scattering and precipitation of energetic electrons, acting as an effective radiation belt remediation scheme. In this work, we revisit the coupling between an electron beam and a magnetized plasma in the framework of linear cold-plasma theory. We show that coupling can occur through two different regimes. In the first, a non-relativistic beam radiates through whistler waves. This is well known, and was in fact the focus of many rockets and space-shuttle campaigns aimed at demonstrating whistler emissions in the eighties. In the second regime, the beam radiates through extraordinary (R-X) modes. Nonlinear simulations with a highly-accurate Vlasov code support the theoretical results qualitatively and demonstrate that the radiated power through R-X modes can be much larger than in the whistler regime. Test-particle simulations in the wave electromagnetic field will also be presented to assess the efficiency of these waves in inducing pitch-angle scattering via wave-particle interactions. Finally, the implications of these results for a rocket active experiment in the ionosphere and for a radiation belt remediation scheme will be discussed.

Project Physics Handbook 6, The Nucleus.

ERIC Educational Resources Information Center

Harvard Univ., Cambridge, MA. Harvard Project Physics.

Five experiments and nine activities are presented in this Unit 6 handbook. The experiments are related to random events, ranges of alpha and beta particles, half-lives, and radioactive tracers. The activities are concerned with the energy measurement in beta radiation, demonstration with sugar cubes, ionization by radioactivity, magnetic…

PHYSICAL FUNDAMENTALS OF QUANTUM ELECTRONICS: Interaction of a sequence of short broad-band radiation pulses with a diatomic molecule

NASA Astrophysics Data System (ADS)

Oraevsky, Anatolii N.; Kozlovskii, Andrei V.; Chichkov, B. N.

1998-07-01

A theoretical analysis is made of the process in which a molecule undergoes a transition between the ground and excited electronic states under the action of a radiation pulse and then, in the interpulse interval, returns to the ground electronic state. Such a periodic process is important in the cooling of molecules by laser radiation. It is shown that the radiation parameters can be selected so that the CO and CN molecules experience over 1000 excitation—relaxation events without dissociation.

Dimension-dependent stimulated radiative interaction of a single electron quantum wavepacket

NASA Astrophysics Data System (ADS)

Gover, Avraham; Pan, Yiming

2018-06-01

In the foundation of quantum mechanics, the spatial dimensions of electron wavepacket are understood only in terms of an expectation value - the probability distribution of the particle location. One can still inquire how the quantum electron wavepacket size affects a physical process. Here we address the fundamental physics problem of particle-wave duality and the measurability of a free electron quantum wavepacket. Our analysis of stimulated radiative interaction of an electron wavepacket, accompanied by numerical computations, reveals two limits. In the quantum regime of long wavepacket size relative to radiation wavelength, one obtains only quantum-recoil multiphoton sidebands in the electron energy spectrum. In the opposite regime, the wavepacket interaction approaches the limit of classical point-particle acceleration. The wavepacket features can be revealed in experiments carried out in the intermediate regime of wavepacket size commensurate with the radiation wavelength.

On the physics of the pressure and temperature gradients in the edge of tokamak plasmas

NASA Astrophysics Data System (ADS)

Stacey, Weston M.

2018-04-01

An extended plasma fluid theory including atomic physics, radiation, electromagnetic and themodynamic forces, external sources of particles, momentum and energy, and kinetic ion orbit loss is employed to derive theoretical expressions that display the role of the various factors involved in the determination of the pressure and temperature gradients in the edge of tokamak plasmas. Calculations for current experiments are presented to illustrate the magnitudes of various effects including strong radiative and atomic physics edge cooling effects and strong reduction in ion particle and energy fluxes due to ion orbit loss in the plasma edge. An important new insight is the strong relation between rotation and the edge pressure gradient.

Research and Engineering Operation, Irradiation Processing Department monthly record report, May 1965

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ambrose, T.W.

1965-06-04

Process and development activities reported include: depleted uranium irradiations, thoria irradiation, and hot die sizing. Reactor engineering activities include: brittle fracture of 190-C tanks, increased graphite temperature limits for the F reactor, VSR channel caulking, K reactor downcomer flow, zircaloy hydriding, and ribbed zircaloy process tubes. Reactor physics activities include: thoria irradiations, E-D irradiations, boiling protection with the high speed scanner, and in-core flux monitoring. Radiological engineering activities include: radiation control, classification, radiation occurrences, effluent activity data, and well car shielding. Process standards are listed, along with audits, and fuel failure experience. Operational physics and process physics studies are presented.more » Lastly, testing activities are detailed.« less

Calculation of Coherent Radiation from Ultra-short Electron Beams Using a Lienard-Wiechert Based Simulation Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flacco, A.; Fairchild, M.; Reiche, S.

2004-12-07

The coherent radiation emitted by electrons in high brightness beam-based experiments is important from the viewpoints of both radiation source development, and the understanding and diagnosing the basic physical processes important in beam manipulations at high intensity. While much theoretical work has been developed to aid in calculating aspects of this class of radiation, these methods do not often produce accurate information concerning the experimentally relevant aspects of the radiation. At UCLA, we are particularly interested in coherent synchrotron radiation and the related phenomena of coherent edge radiation, in the context of a fs-beam chicane compression experiment at the BNLmore » ATF. To analyze this and related problems, we have developed a program that acts as an extension to the Lienard-Wiechert-based 3D simulation code TREDI, termed FieldEye. This program allows the evaluation of electromagnetic fields in the time and frequency domain in an arbitrary 2D detector planar area. We discuss here the implementation of the FieldEye code, and give examples of results relevant to the case of the ATF chicane compressor experiment.« less

Monochromatic radiography of high energy density physics experiments on the MAGPIE generator.

PubMed

Hall, G N; Burdiak, G C; Suttle, L; Stuart, N H; Swadling, G F; Lebedev, S V; Smith, R A; Patankar, S; Suzuki-Vidal, F; de Grouchy, P; Harvey-Thompson, A J; Bennett, M; Bland, S N; Pickworth, L; Skidmore, J

2014-11-01

A monochromatic X-ray backlighter based on Bragg reflection from a spherically bent quartz crystal has been developed for the MAGPIE pulsed power generator at Imperial College (1.4 MA, 240 ns) [I. H. Mitchell et al., Rev. Sci. Instrum. 67, 1533 (2005)]. This instrument has been used to diagnose high energy density physics experiments with 1.865 keV radiation (Silicon He-α) from a laser plasma source driven by a ∼7 J, 1 ns pulse from the Cerberus laser. The design of the diagnostic, its characterisation and performance, and initial results in which the instrument was used to radiograph a shock physics experiment on MAGPIE are discussed.

Final science results: Spacelab J

NASA Technical Reports Server (NTRS)

Leslie, Fred (Editor)

1995-01-01

This report contains a brief summary of the mission science conducted aboard Spacelab J (SL-J), a joint venture between the National Aeronautics and Space Administration (NASA) and the National Space Development Agency (NASDA) of Japan. The scientific objectives of the mission were to conduct a variety of material and life science experiments utilizing the weightlessness and radiation environment of an orbiting Spacelab. All 43 experiments were activated; 24 in microgravity sciences (material processing, crystal growth, fluid physics, and acceleration measurement) and 19 in life sciences (physiology, developmental biology, radiation effects, separation processes, and enzyme crystal growth). In addition, more than a dozen experiments benefited from the extra day through either additional experiment runs or extended growth time.

More Experiments with Microwave Ovens

ERIC Educational Resources Information Center

Vollmer, Michael; Mollmann, Klaus-Peter; Karstadt, Detlef

2004-01-01

Microwave ovens can be used to perform exciting demonstrations that illustrate a variety of physics topics. Experiments discussed here show superheating, visualize the inhomogeneous heating that takes place in a microwave and also show how to use a mobile phone to detect radiation leaking from the oven. Finally eggs can give some spectacular…

Modeling and Experiments with Carbon Nanotubes for Applications in High Performance Circuits

DTIC Science & Technology

2017-04-06

purchased and installed for experimental characterization of atomic layer deposited graphene on different substrates for radiation-hardened studies...72 3.6 Experimental Research in Graphene for Radiation Hardened Devices……………..73 4 Recommendations...physics for analysis and design of integrated circuits. The developed model is verified from published experimental data. Basic logic gates in

Computer Aided Dosimetry and Verification of Exposure to Radiation

NASA Astrophysics Data System (ADS)

Waller, Edward; Stodilka, Robert Z.; Leach, Karen E.; Lalonde, Louise

2002-06-01

In the timeframe following the September 11th attacks on the United States, increased emphasis has been placed on Chemical, Biological, Radiological and Nuclear (CBRN) preparedness. Of prime importance is rapid field assessment of potential radiation exposure to Canadian Forces field personnel. This work set up a framework for generating an 'expert' computer system for aiding and assisting field personnel in determining the extent of radiation insult to military personnel. Data was gathered by review of the available literature, discussions with medical and health physics personnel having hands-on experience dealing with radiation accident victims, and from experience of the principal investigator. Flow charts and generic data fusion algorithms were developed. Relationships between known exposure parameters, patient interview and history, clinical symptoms, clinical work-ups, physical dosimetry, biological dosimetry, and dose reconstruction as critical data indicators were investigated. The data obtained was examined in terms of information theory. A main goal was to determine how best to generate an adaptive model (i.e. when more data becomes available, how is the prediction improved). Consideration was given to determination of predictive algorithms for health outcome. In addition. the concept of coding an expert medical treatment advisor system was developed (U)

Electroweak radiative corrections for polarized Moller scattering at the future 11 GeV JLab experiment

DOE PAGES

Aleksejevs, Aleksandrs; Barkanova, Svetlana; Ilyichev, Alexander; ...

2010-11-19

We perform updated and detailed calculations of the complete NLO set of electroweak radiative corrections to parity violating e – e – → e – e – (γ) scattering asymmetries at energies relevant for the ultra-precise Moller experiment coming soon at JLab. Our numerical results are presented for a range of experimental cuts and relative importance of various contributions is analyzed. In addition, we also provide very compact expressions analytically free from non-physical parameters and show them to be valid for fast yet accurate estimations.

Characterization of HIRF Susceptibility Threshold for a Prototype Implementation of an Onboard Data Network

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo

2012-01-01

An experiment was conducted to characterize the effects of HIRF-induced upsets on a prototype onboard data network. The experiment was conducted at the NASA Langley Research Center s High Intensity Radiation Field Laboratory and used a generic distributed system prototyping platform to realize the data network. This report presents the results of the hardware susceptibility threshold characterization which examined the dependence of measured susceptibility on factors like the frequency and modulation of the radiation, layout of the physical nodes and position of the nodes in the test chamber. The report also includes lessons learned during the development and execution of the experiment.

TU-A-210-01: HIFU Physics and Delivery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eames, M.

2015-06-15

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis inmore » 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. Summarize existing and emerging clinical applications and manufacturers for HIFU. Understand that thermal ablation with HIFU is likely the first of several applications of the technology Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.« less

Sensitivity Analysis and Optimization of Enclosure Radiation with Applications to Crystal Growth

NASA Technical Reports Server (NTRS)

Tiller, Michael M.

1995-01-01

In engineering, simulation software is often used as a convenient means for carrying out experiments to evaluate physical systems. The benefit of using simulations as 'numerical' experiments is that the experimental conditions can be easily modified and repeated at much lower cost than the comparable physical experiment. The goal of these experiments is to 'improve' the process or result of the experiment. In most cases, the computational experiments employ the same trial and error approach as their physical counterparts. When using this approach for complex systems, the cause and effect relationship of the system may never be fully understood and efficient strategies for improvement never utilized. However, it is possible when running simulations to accurately and efficiently determine the sensitivity of the system results with respect to simulation to accurately and efficiently determine the sensitivity of the system results with respect to simulation parameters (e.g., initial conditions, boundary conditions, and material properties) by manipulating the underlying computations. This results in a better understanding of the system dynamics and gives us efficient means to improve processing conditions. We begin by discussing the steps involved in performing simulations. Then we consider how sensitivity information about simulation results can be obtained and ways this information may be used to improve the process or result of the experiment. Next, we discuss optimization and the efficient algorithms which use sensitivity information. We draw on all this information to propose a generalized approach for integrating simulation and optimization, with an emphasis on software programming issues. After discussing our approach to simulation and optimization we consider an application involving crystal growth. This application is interesting because it includes radiative heat transfer. We discuss the computation of radiative new factors and the impact this mode of heat transfer has on our approach. Finally, we will demonstrate the results of our optimization.

Validation experiments to determine radiation partitioning of heat flux to an object in a fully turbulent fire.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricks, Allen; Blanchat, Thomas K.; Jernigan, Dann A.

2006-06-01

It is necessary to improve understanding and develop validation data of the heat flux incident to an object located within the fire plume for the validation of SIERRA/ FUEGO/SYRINX fire and SIERRA/CALORE. One key aspect of the validation data sets is the determination of the relative contribution of the radiative and convective heat fluxes. To meet this objective, a cylindrical calorimeter with sufficient instrumentation to measure total and radiative heat flux had been designed and fabricated. This calorimeter will be tested both in the controlled radiative environment of the Penlight facility and in a fire environment in the FLAME/Radiant Heatmore » (FRH) facility. Validation experiments are specifically designed for direct comparison with the computational predictions. Making meaningful comparisons between the computational and experimental results requires careful characterization and control of the experimental features or parameters used as inputs into the computational model. Validation experiments must be designed to capture the essential physical phenomena, including all relevant initial and boundary conditions. A significant question of interest to modeling heat flux incident to an object in or near a fire is the contribution of the radiation and convection modes of heat transfer. The series of experiments documented in this test plan is designed to provide data on the radiation partitioning, defined as the fraction of the total heat flux that is due to radiation.« less

A journey from nuclear criticality methods to high energy density radflow experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urbatsch, Todd James

Los Alamos National Laboratory is a nuclear weapons laboratory supporting our nation's defense. In support of this mission is a high energy-density physics program in which we design and execute experiments to study radiationhydrodynamics phenomena and improve the predictive capability of our largescale multi-physics software codes on our big-iron computers. The Radflow project’s main experimental effort now is to understand why we haven't been able to predict opacities on Sandia National Laboratory's Z-machine. We are modeling an increasing fraction of the Z-machine's dynamic hohlraum to find multi-physics explanations for the experimental results. Further, we are building an entirely different opacitymore » platform on Lawrence Livermore National Laboratory's National Ignition Facility (NIF), which is set to get results early 2017. Will the results match our predictions, match the Z-machine, or give us something entirely different? The new platform brings new challenges such as designing hohlraums and spectrometers. The speaker will recount his history, starting with one-dimensional Monte Carlo nuclear criticality methods in graduate school, radiative transfer methods research and software development for his first 16 years at LANL, and, now, radflow technology and experiments. Who knew that the real world was more than just radiation transport? Experiments aren't easy, but they sure are fun.« less

Laboratory Studies of the Optical Properties and Condensation Processes of Cosmic Dust Grains

NASA Technical Reports Server (NTRS)

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

2002-01-01

A laboratory facility for conducting a variety of experiments on single isolated dust particles of astrophysical interest levitated in an electrodynamics balance has been developed at NASA/Marshall Space Flight Center. The objective of the research is to employ this experimental technique for studies of the physical and optical properties of individual cosmic dust grains of 0.1-100 micron size in controlled pressure/temperatures environments simulating astrophysical conditions. The physical and optical properties of the analogs of interstellar and interplanetary dust grains of known composition and size distribution will be investigated by this facility. In particular, we will carry out three classes of experiments to study the micro-physics of cosmic dust grains. (1) Charge characteristics of micron size single dust grains to determine the photoelectric efficiencies, yields, and equilibrium potentials when exposed to UV radiation. (2) Infrared optical properties of dust particles (extinction coefficients and scattering phase functions) in the 1-30 micron region using infrared diode lasers and measuring the scattered radiation. (3) Condensation experiments to investigate the condensation of volatile gases on colder nucleated particles in dense interstellar clouds and lower planetary atmospheres. The condensation experiments will involve levitated nucleus dust grains of known composition and initial mass (or m/q ratio), cooled to a temperature and pressure (or scaled pressure) simulating the astrophysical conditions, and injection of a volatile gas at a higher temperature from a controlled port. The increase in the mass due to condensation on the particle will be monitored as a function of the dust particle temperature and the partial pressure of the injected volatile gas. The measured data will permit determination of the sticking coefficients of volatile gases and growth rates of dust particles of astrophysical interest. Some preliminary results based on measurements of photoelectric emission and radiation pressure on single isolated 0.2 to 6.6 micron size silica particles exposed to UV radiation at 120-200 nm and green laser light at 532 nm are presented.

NONCOHERENT RADIATION DUE TO ELECTRONS IN A SYNCHROTRON AND SOME OF ITS APPLICATION (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ado, Yu.M.

1963-01-01

Experiments are described in which the properties ot noncoherent radiation due to electrons accelerated in a synchrotron are investigated. The experiments were performed at the 280-Mev electron synchrotron of the Lebedeff Institute for Physics. An apparatus was constructed for the determination of optical radiation spectra arising from monoenergetic electrons during the complete acceleration cycle. The energy distribution of the radiation was determined for three electron energies, 150, 225, and 250 Mev. The intensity of various wvavelength radiation was measured as a function of the electron energy from 70 to 280 Mev. The effect of the intensity on the number ofmore » electrons was found to be linear for 250-Mev electrons. Three applications are described for the electron optical radiation: the determination of the number of accelerated electrons, the measurement of the amount of electrons hitting a target during the acceleration process, and the determination of the azimuthal extent of the clots of accelerated electrons. (TTT)« less

Time reversal violation in radiative beta decay: experimental plans

NASA Astrophysics Data System (ADS)

Behr, J. A.; McNeil, J.; Anholm, M.; Gorelov, A.; Melconian, D.; Ashery, D.

2017-01-01

Some explanations for the excess of matter over antimatter in the universe involve sources of time reversal violation (TRV) in addition to the one known in the standard model of particle physics. We plan to search for TRV in a correlation between the momenta of the beta, neutrino, and the radiative gamma sometimes emitted in nuclear beta decay. Correlations involving three (out of four) momenta are sensitive at lowest order to different TRV physics than observables involving spin, such as electric dipole moments and spin-polarized beta decay correlations. Such experiments have been done in radiative kaon decay, but not in systems involving the lightest generation of quarks. An explicit low-energy physics model being tested produces TRV effects in the Fermi beta decay of the neutron, tritium, or some positron-decaying isotopes. We will present plans to measure the TRV asymmetry in radiative beta decay of laser-trapped 38mK at better than 0.01 sensitivity, including suppression of background from positron annihilation. Supported by NSERC, D.O.E., Israel Science Foundation. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada.

[Bio-objects and biological methods of space radiation effects evaluation].

PubMed

Kaminskaia, E V; Nevzgodina, L V; Platova, N G

2009-01-01

The unique conditions of space experiments place austere requirements to bio-objects and biological methods of radiation effects evaluation. The paper discusses suitability of a number of bio-objects varying in stage of evolution and metabolism for space researches aimed to state common patterns of the radiation damage caused by heavy ions (HI), and character of HI-cell interaction. Physical detectors in space experiments of the BIOBLOCK series make it possible to identify bio-objects hit by space HI and to set correlation between HI track topography and biological effect. The paper provides an all-round description of the bio-objects chosen for two BIOBLOCK experiments (population of hydrophyte Wolffia arrhiza (fam. duckweed) and Lactuca sativa seeds) and the method of evaluating effects from single space radiation HI. Direct effects of heavy ions on cells can be determined by the criteria of chromosomal aberrations and delayed morphologic abnormalities. The evaluation results are compared with the data about human blood lymphocytes. Consideration is being given to the procedures of test-objects' treatment and investigation.

Radiative precursors driven by converging blast waves in noble gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burdiak, G. C.; Lebedev, S. V.; Harvey-Thompson, A. J.

2014-03-15

A detailed study of the radiative precursor that develops ahead of converging blast waves in gas-filled cylindrical liner z-pinch experiments is presented. The experiment is capable of magnetically driving 20 km s{sup −1} blast waves through gases of densities of the order 10{sup −5} g cm{sup −3} (see Burdiak et al. [High Energy Density Phys. 9(1), 52–62 (2013)] for a thorough description). Data were collected for Ne, Ar, and Xe gas-fills. The geometry of the setup allows a determination of the plasma parameters both in the precursor and across the shock, along a nominally uniform line of sight that is perpendicularmore » to the propagation of the shock waves. Radiation from the shock was able to excite NeI, ArII, and XeII/XeIII precursor spectral features. It is shown that the combination of interferometry and optical spectroscopy data is inconsistent with upstream plasmas being in LTE. Specifically, electron density gradients do not correspond to any apparent temperature change in the emission spectra. Experimental data are compared to 1D radiation hydrodynamics HELIOS-CR simulations and to PrismSPECT atomic physics calculations to assist in a physical interpretation of the observations. We show that upstream plasma is likely in the process of being radiatively heated and that the emission from a small percentage of ionised atoms within a cool background plasma dominates the emission spectra. Experiments were carried out on the MAGPIE and COBRA pulsed-power facilities at Imperial College London and Cornell University, respectively.« less

Quality of Subjective Experience in a Summer Science Program for Academically Talented Adolescents.

ERIC Educational Resources Information Center

Tuss, Paul

This study utilized the flow theory of intrinsic motivation to evaluate the subjective experience of 78 academically talented high school sophomores participating in an 8-day summer research apprenticeship program in materials and nuclear science. The program involved morning lectures on such topics as physics of electromagnetic radiation, energy…

Detectors for Particle Radiation

NASA Astrophysics Data System (ADS)

Kleinknecht, Konrad

1999-01-01

This textbook provides a clear, concise and comprehensive review of the physical principles behind the devices used to detect charged particles and gamma rays, and the construction and performance of these many different types of detectors. Detectors for high-energy particles and radiation are used in many areas of science, especially particle physics and nuclear physics experiments, nuclear medicine, cosmic ray measurements, space sciences and geological exploration. This second edition includes all the latest developments in detector technology, including several new chapters covering micro-strip gas chambers, silicion strip detectors and CCDs, scintillating fibers, shower detectors using noble liquid gases, and compensating calorimeters for hadronic showers. This well-illustrated textbook contains examples from the many areas in science in which these detectors are used. It provides both a coursebook for students in physics, and a useful introduction for researchers in other fields.

An experiment to measure the one-way velocity of propagation of electromagnetic radiation

NASA Technical Reports Server (NTRS)

Kolen, P.; Torr, D. G.

1982-01-01

An experiment involving commercially available instrumentation to measure the velocity of the earth with respect to absolute space is described. The experiment involves the measurement of the one-way propagation velocity of electromagnetic radiation down a high-quality coaxial cable. It is demonstrated that the experiment is both physically meaningful and exceedingly simple in concept and in implementation. It is shown that with currently available commercial equipment one might expect to detect a threshold value for the component of velocity of the earth's motion with respect to absolute space in the equatorial plane of approximately 10 km/s, which greatly exceeds the velocity resolution required to detect the motion of the solar system with respect to the center of the galaxy.

Cool in the kitchen: Radiation, conduction, and the Newton ``hot block'' experiment

NASA Astrophysics Data System (ADS)

Silverman, Mark P.; Silverman, Christopher R.

2000-02-01

Despite frequent reference to Newton's law of cooling in physics and math books, the paper in which Newton reported this law is quite obscure and rarely cited. We have managed to acquire a copy of this paper and discuss the interesting experiment that Newton did in his kitchen. Surprisingly, the paper contains no procedural details or data of any experiments measuring the rate at which a hot object cools. We have performed our own kitchen experiments to investigate the cooling of (a) the burner of an electric range and (b) a block of Styrofoam. Newton's law provides a poor model for both systems, whose th! ! ermal energy loss we can much better understand by examining closely the effects of radiation and conduction.

Source Physics Experiment: Research in Support of Verification and Nonproliferation

DTIC Science & Technology

2011-09-01

designed to provide a carefully controlled seismic and strong motion data set from buried explosions at the Nevada National Security Site (NNSS). The...deposition partitioned into internal (heat and plastic strain) and kinetic (e.g., radiated seismic ) energy, giving more confidence in predicted free...ample information to study dry and water-saturated fractures, local lithology and topography on the radiated seismic wavefield. Spallation on

Radiation Protection

NASA Astrophysics Data System (ADS)

Grupen, Claus

Radiation protection is a very important aspect for the application of particle detectors in many different fields, like high energy physics, medicine, materials science, oil and mineral exploration, and arts, to name a few. The knowledge of radiation units, the experience with shielding, and information on biological effects of radiation are vital for scientists handling radioactive sources or operating accelerators or X-ray equipment. This article describes the modern radiation units and their conversions to older units which are still in use in many countries. Typical radiation sources and detectors used in the field of radiation protection are presented. The legal regulations in nearly all countries follow closely the recommendations of the International Commission on Radiological Protection (ICRP). Tables and diagrams with relevant information on the handling of radiation sources provide useful data for the researcher working in this field.

The Biostack Experiments I and II aboard Apollo 16 and 17.

PubMed

Bucker, H

1974-01-01

The concept of the Biostack experiment has become practicable through European scientific collaboration and with help of NASA. The objectives of this experiment flown aboard Apollo 16 and 17 are to study the biological effects of individual heavy cosmic particles of high-energy loss (HZE) not available on earth; to study the influence of additional spaceflight factors; to get some knowledge on the mechanism by which HZE particles damage biological materials; to get information on the spectrum of charge and energy of the cosmic ions in the spacecraft; to estimate the radiation hazards for man in space. For this purpose the Biostack experiment comprises a widespread spectrum of biological objects, and various radiobiological end-points are under investigation. Bacterial spores, protozoa cysts, plant seeds, shrimp eggs, and insect eggs were included in the Biostack experiment packages together with different physical radiation detectors (nuclear emulsions, plastics, AgCl crystals, and LiF thermoluminescence dosimeters). By using special arrangements of biological objects and physical track detectors, individual evaluation of tracks was obtained allowing the identification of each penetrating particle in relation to the possible biological effects on its path. The response of the different biological objects to space flight and HZE ions bombardment was of different degree, presumably depending on the ability of the organism to replace the cells damaged by a hit. The results help to estimate the radiation hazard for astronauts during space missions of long duration.

A case study of successful e-learning: a web-based distance course in medical physics held for school teachers of the upper secondary level.

PubMed

Jönsson, Bo-Anders

2005-09-01

Learning activities and course design in the new context of e-learning, such as in web-based courses involves a change both for teachers and students. The paper discusses factors important for e-learning to be successful. The development of an online course in medical physics and technology for high school teachers of physics, details of the course, and experience gained in connection with it are described. The course syllabus includes basics of radiation physics, imaging techniques using ionizing or non-ionizing radiation, and external and internal radiation therapy. The course has a highly didactic approach. The final task is for participants to design a course of their own centered on some topic of medical physics on the basis of the knowledge they have acquired. The aim of the course is to help the teachers integrate medical physics into their own teaching. This is seen as enhancing the interest of high school students in later studying physics, medical physics or some other branch of science at the university level, and as increasing the knowledge that they and people generally have of science. It is suggested that the basic approach taken can also have applicability to the training of medical, nursing or engineering students, and be used for continuing professional development in various areas.

A radiatively pumped CW CO2 laser

NASA Technical Reports Server (NTRS)

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

1984-01-01

A proof of principle experiment to demonstrate the physics of a radiatively pumped laser has been carried out. For the first time, a blackbody cavity has optically pumped a CW CO2 laser. Results are presented from a series of experiments using mixtures of CO2, He, and Ar in which maximum output power was obtained with a 20 percent CO2-15 percent He-65 percent Ar mixture. The dependence of the output power on the blackbody temperature and the cooling gas flow rate is also discussed. By appropriately varying these parameters, continuous output powers of 8-10 mW have been achieved.

Status of diamond particle detectors

NASA Astrophysics Data System (ADS)

Krammer, M.; Adam, W.; Bauer, C.; Berdermann, E.; Bogani, F.; Borchi, E.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; van Eijk, B.; Fallou, A.; Fish, D.; Foulon, F.; Friedl, M.; Gan, K. K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Knöpfle, K. T.; Manfredi, P. F.; Meier, D.; Mishina, M.; LeNormand, F.; Pan, L. S.; Pernegger, H.; Pernicka, M.; Re, V.; Riester, G. L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R. J.; Tesarek, R.; Thomson, G. B.; Trawick, M.; Trischuk, W.; Turchetta, R.; Walsh, A. M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M.

1998-11-01

To continue the exciting research in the field of particle physics new accelerators and experiments are under construction. In some of these experiments, e.g. ATLAS and CMS at the Large Hadron Collider at CERN or HERA-B at DESY, the detectors have to withstand an extreme environment. The detectors must be radiation hard, provide a very fast signal, and be as thin as possible. The properties of CVD diamond allow to fulfill these requirements and make it an ideal material for the detectors close to the interaction region of these experiments, i.e. the vertex detectors or the inner trackers. The RD42 collaboration is developing diamond detectors for these applications. The program of RD42 includes the improvement of the charge collection properties of CVD diamond, the study of the radiation hardness and the development of low-noise radiation hard readout electronics. An overview of the progress achieved during the last years will be given.

Fuego/Scefire MPMD Coupling L2 Milestone Executive Summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, Flint; Tencer, John; Pautz, Shawn D.

2017-09-01

This milestone campaign was focused on coupling Sandia physics codes SIERRA low Mach module Fuego and RAMSES Boltzmann transport code Sceptre(Scefire). Fuego enables simulation of low Mach, turbulent, reacting, particle laden flows on unstructured meshes using CVFEM for abnormal thermal environments throughout SNL and the larger national security community. Sceptre provides simulation for photon, neutron, and charged particle transport on unstructured meshes using Discontinuous Galerkin for radiation effects calculations at SNL and elsewhere. Coupling these ”best of breed” codes enables efficient modeling of thermal/fluid environments with radiation transport, including fires (pool, propellant, composite) as well as those with directed radiantmore » fluxes. We seek to improve the experience of Fuego users who require radiation transport capabilities in two ways. The first is performance. We achieve this through leveraging additional computational resources for Scefire, reducing calculation times while leaving unaffected resources for fluid physics. This approach is new to Fuego, which previously utilized the same resources for both fluid and radiation solutions. The second improvement enables new radiation capabilities, including spectral (banded) radiation, beam boundary sources, and alternate radiation solvers (i.e. Pn). This summary provides an overview of these achievements.« less

Implementing Computer Based Laboratories

NASA Astrophysics Data System (ADS)

Peterson, David

2001-11-01

Physics students at Francis Marion University will complete several required laboratory exercises utilizing computer-based Vernier probes. The simple pendulum, the acceleration due to gravity, simple harmonic motion, radioactive half lives, and radiation inverse square law experiments will be incorporated into calculus-based and algebra-based physics courses. Assessment of student learning and faculty satisfaction will be carried out by surveys and test results. Cost effectiveness and time effectiveness assessments will be presented. Majors in Computational Physics, Health Physics, Engineering, Chemistry, Mathematics and Biology take these courses, and assessments will be categorized by major. To enhance the computer skills of students enrolled in the courses, MAPLE will be used for further analysis of the data acquired during the experiments. Assessment of these enhancement exercises will also be presented.

TU-A-210-00: HIFU Therapies - A Primer

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2015-06-15

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis inmore » 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. Summarize existing and emerging clinical applications and manufacturers for HIFU. Understand that thermal ablation with HIFU is likely the first of several applications of the technology Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.« less

KSC-2013-3906

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities.

Updating the Synchrotron Radiation Monitor at TLS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuo, C. H.; Hsu, S. Y.; Wang, C. J.

2007-01-19

The synchrotron radiation monitor provides useful information to support routine operation and physics experiments using the beam. Precisely knowing the profile of the beam helps to improve machine performance. The synchrotron radiation monitor at the Taiwan Light Source (TLS) was recently upgraded. The optics and modeling were improved to increase the accuracy of measurement in the small beam size. A high-performance IEEE-1394 digital CCD camera was used to improve the quality of images and extend the dynamic range of measurement. The image analysis is also improved. This report summarizes status and results.

Quantitative comparisons between experimentally measured 2D carbon radiation and Monte Carlo impurity (MCI) code simulations

NASA Astrophysics Data System (ADS)

Evans, T. E.; Finkenthal, D. F.; Fenstermacher, M. E.; Leonard, A. W.; Porter, G. D.; West, W. P.

Experimentally measured carbon line emissions and total radiated power distributions from the DIII-D divertor and scrape-off layer (SOL) are compared to those calculated with the Monte Carlo impurity (MCI) model. A UEDGE [T.D. Rognlien et al., J. Nucl. Mater. 196-198 (1992) 347] background plasma is used in MCI with the Roth and Garcia-Rosales (RG-R) chemical sputtering model [J. Roth, C. García-Rosales, Nucl. Fusion 36 (1992) 196] and/or one of six physical sputtering models. While results from these simulations do not reproduce all of the features seen in the experimentally measured radiation patterns, the total radiated power calculated in MCI is in relatively good agreement with that measured by the DIII-D bolometric system when the Smith78 [D.L. Smith, J. Nucl. Mater. 75 (1978) 20] physical sputtering model is coupled to RG-R chemical sputtering in an unaltered UEDGE plasma. Alternatively, MCI simulations done with UEDGE background ion temperatures along the divertor target plates adjusted to better match those measured in the experiment resulted in three physical sputtering models which when coupled to the RG-R model gave a total radiated power that was within 10% of measured value.

Features of Changing Microwave Radiation from Loaded Rock in Elastic Phase

NASA Astrophysics Data System (ADS)

Wu, Lixin; Mao, Wenfei; Huang, Jianwei; Liu, Shanjun; Xu, Zhongying

2017-04-01

Since the discovery of satellite infrared anomaly occurred before some earthquake by Russian geo-scientists in 1980's, both satellite remote sensing on seismic activities and experimental infrared detection on rock physics in process of rock loading were undertaken in many counties including China, Japan, Europe nations and United States. Infrared imager and spectrum instruments were applied to detect the changed infrared radiation from loaded rock to fracturing, which lead to the development of Remote Sensing Rock Mechanics. However, the change of microwave radiation from loaded rock was not so much studied, even if abnormal changes of microwave brightness temperature (MBT) preceding some large earthquakes were observed by satellite sensors such as AMSR-E on boarded Aqua. To monitor rock hazards, seismic activities, and to make earthquake precautions by via of microwave detection or microwave remote sensing, it is fairly demanded to explore the laws of microwave radiation variation with changed stress and to uncover the rock physics. We developed a large scale rock loading system with capability of 500 tons and 10 tons of load, respectively, at two horizontal loading head, and designed a group of microwave detectors in C, K, and Ka bands. To investigate the changed microwave radiation from loaded granite and sandstone in its elastics deformation phase, the first horizontal stress was circularly applied on rock samples of size 10×30×60cm3 at a constant second horizontal stress, and the changes microwave radiation was detected by the detectors hanged overhead the rock sample. The experiments were conducted outdoor at nighttime to keep off environmental radiation and to simulate the satellite observation conditions in background of cool sky. The first horizontal stress and the microwave radiations were synchronically detected and recorded. After reducing the random noise of detected microwave signals with wavelet method, we found the MBT increase with stress rising and decrease with stress dropping, and the correlation factor (R2) of MBT-stress reached 0.88. The experiments and results revealed an important rock physical phenomenon of rock dielectric property changing with stress, which leads to detectable MBT variation.

Analysis of the Radiated Field in an Electromagnetic Reverberation Chamber as an Upset-Inducing Stimulus for Digital Systems

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo

2012-01-01

Preliminary data analysis for a physical fault injection experiment of a digital system exposed to High Intensity Radiated Fields (HIRF) in an electromagnetic reverberation chamber suggests a direct causal relation between the time profile of the field strength amplitude in the chamber and the severity of observed effects at the outputs of the radiated system. This report presents an analysis of the field strength modulation induced by the movement of the field stirrers in the reverberation chamber. The analysis is framed as a characterization of the discrete features of the field strength waveform responsible for the faults experienced by a radiated digital system. The results presented here will serve as a basis to refine the approach for a detailed analysis of HIRF-induced upsets observed during the radiation experiment. This work offers a novel perspective into the use of an electromagnetic reverberation chamber to generate upset-inducing stimuli for the study of fault effects in digital systems.

Nonequilibrium radiation behind a strong shock wave in CO 2-N 2

NASA Astrophysics Data System (ADS)

Rond, C.; Boubert, P.; Félio, J.-M.; Chikhaoui, A.

2007-11-01

This work presents experiments reproducing plasma re-entry for one trajectory point of a Martian mission. The typical facility to investigate such hypersonic flow is shock tube; here we used the free-piston shock tube TCM2. Measurements of radiative flux behind the shock wave are realized thanks to time-resolved emission spectroscopy which is calibrated in intensity. As CN violet system is the main radiator in near UV-visible range, we have focused our study on its spectrum. Moreover a physical model, based on a multi-temperature kinetic code and a radiative code, for calculation of non equilibrium radiation behind a shock wave is developed for CO 2-N 2-Ar mixtures. Comparisons between experiments and calculations show that standard kinetic models (Park, McKenzie) are inefficient to reproduce our experimental results. Therefore we propose new rate coefficients in particular for the dissociation of CO 2, showing the way towards a better description of the chemistry of the mixture.

Observation of a Hydrodynamically Driven, Radiative Precursor Shock

NASA Astrophysics Data System (ADS)

Keiter, P. A.; Drake, R. P.; Perry, T. S.; Robey, H.; Remington, B. A.; Iglesias, C. A.; Turner, N.; Stone, J.; Knauer, J.

2001-10-01

Many astrophysical systems, such as supernova remnants and jets, produce radiative-precursor shock waves. In a radiative-precursor shock, radiation from the shock ionizes and heats the medium ahead of it. The simulation of such systems requires that one treat both the emission and the absorption of the radiation. An important goal of this effort is to produce an experiment that can be modeled by astrophysical codes without implementing laser absorption physics into an astrophysical code. We report here the first measurements of a radiative-precursor shock in such an experiment. The experimental design is based on a past experiment[1,2] that used the Nova laser facility to simulate young supernova remnants. The target consists of a 60 νm CH plastic plug followed by a 150 νm vacuum gap and 2 mm of SiO2 aerogel foam. For the experiment, the density of the components and the laser-irradiation conditions are chosen so that the driven shock will produce an observable radiative precursor. We observed the radiative-precursor by using absorption spectroscopy. By backlighting the silicate aerogel foam with a thulium backlighter, we were able to observe both the 1s-2p and 1s-3p lines. These observations will allow us to determine the temperature profile in the precursor. 1. R.P. Drake, et al, Phys. Rev. Lett. 81, 2068 (1998). 2. R.P. Drake, et al., Phys. Plasmas, 7, 2142 (2000) Work supported by the U.S. Department of Energy both directly and through the Lawrence Livermore National Laboratory

A journey from nuclear criticality methods to high energy density radflow experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urbatsch, Todd James

Los Alamos National Laboratory is a nuclear weapons laboratory supporting our nation's defense. In support of this mission is a high energy-density physics program in which we design and execute experiments to study radiationhydrodynamics phenomena and improve the predictive capability of our largescale multi-physics software codes on our big-iron computers. The Radflow project’s main experimental effort now is to understand why we haven't been able to predict opacities on Sandia National Laboratory's Z-machine. We are modeling an increasing fraction of the Z-machine's dynamic hohlraum to find multi-physics explanations for the experimental results. Further, we are building an entirely different opacitymore » platform on Lawrence Livermore National Laboratory's National Ignition Facility (NIF), which is set to get results early 2017. Will the results match our predictions, match the Z-machine, or give us something entirely different? The new platform brings new challenges such as designing hohlraums and spectrometers. The speaker will recount his history, starting with one-dimensional Monte Carlo nuclear criticality methods in graduate school, radiative transfer methods research and software development for his first 16 years at LANL, and, now, radflow technology and experiments. Who knew that the real world was more than just radiation transport? Experiments aren't easy and they are as saturated with politics as a presidential election, but they sure are fun.« less

Theory of acoustic radiation pressure for actual fluids

NASA Astrophysics Data System (ADS)

Doinikov, Alexander A.

1996-12-01

A body irradiated by a sound field is known to experience a steady force that is called the acoustic radiation pressure. This force plays an important role in many physical phenomena, such as cavitation, sonoluminescence, acoustic levitation, etc. The existing theory of acoustic radiation pressure neglects dissipative effects. The present paper develops a theory that takes these effects into account, both dissipative mechanisms, viscous and thermal, being considered. It is shown that, when they are no longer negligible, the dissipative effects drastically change the radiation pressure. As a result, its magnitude and sign become different from those predicted by the ``classical'' theory neglecting losses.

TU-A-210-02: HIFU: Why Should a Radiation Oncology Physicist Pay Attention?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schlesinger, D.

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis inmore » 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. Summarize existing and emerging clinical applications and manufacturers for HIFU. Understand that thermal ablation with HIFU is likely the first of several applications of the technology Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.« less

Space Environment (Natural and Induced)

NASA Technical Reports Server (NTRS)

Kim, Myung-Hee Y.; George, Kerry A.; Cucinotta, Francis A.

2007-01-01

Considerable effort and improvement have been made in the study of ionizing radiation exposure occurring in various regions of space. Satellites and spacecrafts equipped with innovative instruments are continually refining particle data and providing more accurate information on the ionizing radiation environment. The major problem in accurate spectral definition of ionizing radiation appears to be the detailed energy spectra, especially at high energies, which is important parameter for accurate radiation risk assessment. Magnitude of risks posed by exposure to radiation in future space missions is subject to the accuracies of predictive forecast of event size of SPE, GCR environment, geomagnetic fields, and atmospheric radiation environment. Although heavy ion fragmentations and interactions are adequately resolved through laboratory study and model development, improvements in fragmentation cross sections for the light nuclei produced from HZE nuclei and their laboratory validation are still required to achieve the principal goal of planetary GCR simulation at a critical exposure site. More accurate prediction procedure for ionizing radiation environment can be made with a better understanding of the solar and space physics, fulfillment of required measurements for nuclear/atomic processes, and their validation and verification with spaceflights and heavy ion accelerators experiments. It is certainly true that the continued advancements in solar and space physics combining with physical measurements will strengthen the confidence of future manned exploration of solar system. Advancements in radiobiology will surely give the meaningful radiation hazard assessments for short and long term effects, by which appropriate and effective mitigation measures can be placed to ensure that humans safely live and work in the space, anywhere, anytime.

Structure of "Ventilation and Warming" in Notes on Nursing Written by Florence Nightingale in 19th Century: Introduction of Basic Physics to Nursing Students

NASA Astrophysics Data System (ADS)

Ogoh, Kazutoshi

"Basic Natural Science" for freshmen at Miyazaki Prefectural Nursing University has a component including physics. Here students learn three principles of thermal transfer; conduction, radiation, and convection through a series of experiments. The purpose of these experiments is to understand the structure of a method for the caring of breathing and temperature of patients as written in "Ventilation and Warming", the first chapter of F. Nightingale's Notes on Nursing. Students can then apply this structure to retain fresh air in today's hospital rooms, and can then appreciate studying real physics incorporated into fundamental knowledge for nursing practice.

A note on the contribution of multi-photon processes to radiative opacity

NASA Astrophysics Data System (ADS)

Pain, Jean-Christophe

2018-03-01

Recently, Bailey et al. performed iron opacity measurements on the Z machine at Sandia National Laboratory in conditions close to the ones of the base of the convective zone of the Sun. Such experiments have raised questions about the physical models commonly used in opacity codes. To understand the discrepancy between experiment and theory, More et al. investigated the role of two-photon processes. In the present work we show, by simple estimate and using hydrogenic formulas, that due to the intensity of the backlight radiation seen by the sample, such processes are likely to play an important role only for highly excited states.

Preliminary results of the scientific experiments on the Kosmos-936 biosatellite

NASA Technical Reports Server (NTRS)

1977-01-01

The scientific equipment and experiments on the Kosmos-936 biosatellite are described, including various ground controls and the lab unit for studies at the descent vehicle landing site. Preliminary results are presented of the physiological experiment with rats, biological experiments with drosophila and higher and lower plants, and radiation physics and radiobiology studies for the planning of biological protection on future space flights. The most significant conclusion from the preliminary data is that rats tolerate space flight better with an artificial force of gravity.

An Overview of Regional Experiments on Biomass Burning Aerosols and Related Pollutants in Southeast Asia: From BASE-ASIA and the Dongsha Experiment to 7-SEAS

NASA Technical Reports Server (NTRS)

Lin, Neng-Huei; Tsay, Si-Chee; Maring, Hal B.; Yen, Ming-Cheng; Sheu, Guey-Rong; Wang, Sheng-Hsiang; Chi, Kai Hsien; Chuang, Ming-Tung; Ou-Yang, Chang-Feng; Fu, Joshua S.;

Radiation-induced gene expression in the nematode Caenorhabditis elegans

NASA Technical Reports Server (NTRS)

Nelson, Gregory A.; Jones, Tamako A.; Chesnut, Aaron; Smith, Anna L.

2002-01-01

We used the nematode C. elegans to characterize the genotoxic and cytotoxic effects of ionizing radiation in a simple animal model emphasizing the unique effects of charged particle radiation. Here we demonstrate by RT-PCR differential display and whole genome microarray hybridization experiments that gamma rays, accelerated protons and iron ions at the same physical dose lead to unique transcription profiles. 599 of 17871 genes analyzed (3.4%) showed differential expression 3 hrs after exposure to 3 Gy of radiation. 193 were up-regulated, 406 were down-regulated and 90% were affected only by a single species of radiation. A novel statistical clustering technique identified the regulatory relationships between the radiation-modulated genes and showed that genes affected by each radiation species were associated with unique regulatory clusters. This suggests that independent homeostatic mechanisms are activated in response to radiation exposure as a function of track structure or ionization density.

Deconvolution of acoustic emissions for source localization using time reverse modeling

NASA Astrophysics Data System (ADS)

Kocur, Georg Karl

2017-01-01

Impact experiments on small-scale slabs made of concrete and aluminum were carried out. Wave motion radiated from the epicenter of the impact was recorded as voltage signals by resonant piezoelectric transducers. Numerical simulations of the elastic wave propagation are performed to simulate the physical experiments. The Hertz theory of contact is applied to estimate the force impulse, which is subsequently used for the numerical simulation. Displacements at the transducer positions are calculated numerically. A deconvolution function is obtained by comparing the physical (voltage signal) and the numerical (calculated displacement) experiments. Acoustic emission signals due to pencil-lead breaks are recorded, deconvolved and applied for localization using time reverse modeling.

Effects of infrared-A irradiation on skin: discrepancies in published data highlight the need for an exact consideration of physical and photobiological laws and appropriate experimental settings.

PubMed

Piazena, Helmut; Kelleher, Debra K

2010-01-01

Skin exposure to infrared (IR) radiation should be limited in terms of irradiance, exposure time and frequency in order to avoid acute or chronic damage. Recommendations aimed at protecting humans from the risks of skin exposure to IR (e.g. ICNIRP, ACGIH) are only defined in terms of acute effects (e.g. heat pain and cardiovascular collapse), whereas the actual exposure conditions (e.g. spectral distribution, exposure geometry, frequency and number of exposures, thermal exchange with the environment, metabolic energy production and regulatory responses) are not taken into consideration. Since the IR component of solar radiation reaching the Earth's surface is mainly IR-A, and considering the increased use of devices emitting artificially generated IR-A radiation, this radiation band is of special interest. A number of in vitro and/or in vivo investigations assessing cellular or tissue damage caused by IR-A radiation have been undertaken. While such studies are necessary for the development of safety recommendations, the results of measurements undertaken to examine the interaction between skin and IR radiation emitted from different sources presented in this study, together with the detailed examination of the literature reveals a wide spectrum of contradictory findings, which in some instances may be related to methodological shortcomings or fundamental errors in the application of physical and photobiological laws, thus highlighting the need for physically and photobiologically appropriate experiments.

Future space experiments on cosmic rays and radiation on Russian segments of ISS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panasyuk, Mikhail; Galper, Arkady; Stozhov, Yurii

1999-01-22

The report presents a survey of the Russian space program in the field of radiation and cosmic ray studies. The experimental projects were developed by scientists of different Russian Institutes and are intended for implementation on the future ISS. All the projects mentioned in this report have undergone various expertise stages in the Space Council of the Russian Science Academy ('Cosmic Ray Physics' section); the International Science-Technology Center of the Rocket-Space Corporation 'Energia' ('Astrophysics and radiation Measurements' section); Committee on Science-Technical Co-operation of the Russian Space Agency.

Status of the Siberian synchrotron radiation center

NASA Astrophysics Data System (ADS)

Ancharov, A. I.; Baryshev, V. B.; Chernov, V. A.; Gentselev, A. N.; Goldenberg, B. G.; Kochubei, D. I.; Korchuganov, V. N.; Kulipanov, G. N.; Kuzin, M. V.; Levichev, E. B.; Mezentsev, N. A.; Mishnev, S. I.; Nikolenko, A. D.; Pindyurin, V. F.; Sheromov, M. A.; Tolochko, B. P.; Sharafutdinov, M. R.; Shmakov, A. N.; Vinokurov, N. A.; Vobly, P. D.; Zolotarev, K. V.

2005-05-01

Synchrotron radiation (SR) experiments at the Budker Institute of Nuclear Physics had been started in 1973, and from 1981 the Siberian Synchrotron Radiation Center (SSRC) had an official status as Research Center of the Russian Academy of Sciences. SSRC is the research center, which is open and free of tax for the research teams from Russia and abroad. In this report some technical information about the storage rings—SR sources of the Budker INP, the main directions of activity of SSRC, experimental stations, experimental works and users—is given. Development of the free electron lasers, new SR sources and insertion devices is described.

Medical physics staffing for radiation oncology: a decade of experience in Ontario, Canada

PubMed Central

Battista, Jerry J.; Patterson, Michael S.; Beaulieu, Luc; Sharpe, Michael B.; Schreiner, L. John; MacPherson, Miller S.; Van Dyk, Jacob

2012-01-01

The January 2010 articles in The New York Times generated intense focus on patient safety in radiation treatment, with physics staffing identified frequently as a critical factor for consistent quality assurance. The purpose of this work is to review our experience with medical physics staffing, and to propose a transparent and flexible staffing algorithm for general use. Guided by documented times required per routine procedure, we have developed a robust algorithm to estimate physics staffing needs according to center‐specific workload for medical physicists and associated support staff, in a manner we believe is adaptable to an evolving radiotherapy practice. We calculate requirements for each staffing type based on caseload, equipment inventory, quality assurance, educational programs, and administration. Average per‐case staffing ratios were also determined for larger‐scale human resource planning and used to model staffing needs for Ontario, Canada over the next 10 years. The workload specific algorithm was tested through a survey of Canadian cancer centers. For center‐specific human resource planning, we propose a grid of coefficients addressing specific workload factors for each staff group. For larger scale forecasting of human resource requirements, values of 260, 700, 300, 600, 1200, and 2000 treated cases per full‐time equivalent (FTE) were determined for medical physicists, physics assistants, dosimetrists, electronics technologists, mechanical technologists, and information technology specialists, respectively. PACS numbers: 87.55.N‐, 87.55.Qr PMID:22231223

Medical physics staffing for radiation oncology: a decade of experience in Ontario, Canada.

PubMed

Battista, Jerry J; Clark, Brenda G; Patterson, Michael S; Beaulieu, Luc; Sharpe, Michael B; Schreiner, L John; MacPherson, Miller S; Van Dyk, Jacob

2012-01-05

The January 2010 articles in The New York Times generated intense focus on patient safety in radiation treatment, with physics staffing identified frequently as a critical factor for consistent quality assurance. The purpose of this work is to review our experience with medical physics staffing, and to propose a transparent and flexible staffing algorithm for general use. Guided by documented times required per routine procedure, we have developed a robust algorithm to estimate physics staffing needs according to center-specific workload for medical physicists and associated support staff, in a manner we believe is adaptable to an evolving radiotherapy practice. We calculate requirements for each staffing type based on caseload, equipment inventory, quality assurance, educational programs, and administration. Average per-case staffing ratios were also determined for larger-scale human resource planning and used to model staffing needs for Ontario, Canada over the next 10 years. The workload specific algorithm was tested through a survey of Canadian cancer centers. For center-specific human resource planning, we propose a grid of coefficients addressing specific workload factors for each staff group. For larger scale forecasting of human resource requirements, values of 260, 700, 300, 600, 1200, and 2000 treated cases per full-time equivalent (FTE) were determined for medical physicists, physics assistants, dosimetrists, electronics technologists, mechanical technologists, and information technology specialists, respectively.

BASIC RADIATION PROTECTION EDUCATION AND TRAINING FOR MEDICAL PROFESSIONALS; GEORGIAN EXPERIENCE AND FUTURE PERSPECTIVE.

PubMed

Todua, F; Nadareishvili, D; Ormotsadze, G; Sanikidze, T

2016-06-01

The level of knowledge provided by the Tbilisi State Medical University (TSMU) standard curriculum modules in 'Medical physics' and 'Radiation risk estimates' was assessed as was the learning outcome of modern standards elective course in 'Radiation protection'. Two groups of medical students were examined: Group 1: 5 y students, participants in elective course 'Radiobiology and radiogenic health risk' and Group 2: 1-2 y students, participants in winter and summer schools. Students were tested before and after training courses with the same tests questionnaire. The results of the tests showed the necessity for improvement of the educational curriculum. The changes needed are the inclusion of a basic radiobiological course in the curricula of the faculty of medicine and expansion of the medical physics course through a more detailed presentation of medical imaging methods. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Validation of non-local electron heat conduction model for radiation MHD simulation in magnetized laser plasma

NASA Astrophysics Data System (ADS)

Nagatomo, Hideo; Matsuo, Kazuki; Nicolai, Pilippe; Asahina, Takashi; Fujioka, Shinsuke

2017-10-01

In laser plasma physics, application of an external magnetic field is an attractive method for various research of high energy density physics including fast ignition. Meanwhile, in the high intense laser plasma the behavior of hot electron cannot be ignored. In the radiation hydrodynamic simulation, a classical electron conduction model, Spitzer-Harm model has been used in general. However the model has its limit, and modification of the model is necessary if it is used beyond the application limit. Modified SNB model, which considering the influence of magnetic field is applied to 2-D radiation magnetohydrodynamic code PINOCO. Some experiments related the non-local model are carried out at GXII, Osaka University. In this presentation, these experimental results are shown briefly. And comparison between simulation results considering the non-local electron heat conduction mode are discussed. This study was supported JSPS KAKENHI Grant No. 17K05728.

Modeling Aspects Of Nature Of Science To Preservice Elementary Teachers

NASA Astrophysics Data System (ADS)

Ashcraft, Paul

2007-01-01

Nature of science was modeled using guided inquiry activities in the university classroom with elementary education majors. A physical science content course initially used an Aristotelian model where students discussed the relationship between distance from a constant radiation source and the amount of radiation received based on accepted ``truths'' or principles and concluded that there was an inverse relationship. The class became Galilean in nature, using the scientific method to test that hypothesis. Examining data, the class rejected their hypothesis and concluded that there is an inverse square relationship. Assignments, given before and after the hypothesis testing, show the student's misconceptions and their acceptance of scientifically acceptable conceptions. Answers on exam questions further support this conceptual change. Students spent less class time on the inverse square relationship later when examining electrostatic force, magnetic force, gravity, and planetary solar radiation because the students related this particular experience to other physical relationships.

Determination of the Wavelength of u.h.f. TV Transmissions

ERIC Educational Resources Information Center

Gaskell, D. C.

1973-01-01

Describes an experiment suitable for high school physics classes in which students determine the wavelength of electromagnetic radiation of u.h.f. television transmissions. Elaborate equipment is not required, and details are given for the construction of a dipole. (JR)

Antiparticle cloud temperatures for antihydrogen experiments

NASA Astrophysics Data System (ADS)

Bianconi, A.; Charlton, M.; Lodi Rizzini, E.; Mascagna, V.; Venturelli, L.

2017-07-01

A simple rate-equation description of the heating and cooling of antiparticle clouds under conditions typical of those found in antihydrogen formation experiments is developed and analyzed. We include single-particle collisional, radiative, and cloud expansion effects and, from the modeling calculations, identify typical cooling phenomena and trends and relate these to the underlying physics. Some general rules of thumb of use to experimenters are derived.

Measurements of Photoelectric Yield and Physical Properties of Individual Lunar Dust Grains

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Tankosic, D.; Craven, P. D.; Spann, J. F.; LeClair, A.; West, F. A.; Taylor, L.; Hoover, R.

2005-01-01

Micron size dust grains levitated and transported on the lunar surface constitute a major problem for the robotic and human habitat missions for the Moon. It is well known since the Apollo missions that the lunar surface is covered with a thick layer of micron/sub-micron size dust grains. Transient dust clouds over the lunar horizon were observed by experiments during the Apollo 17 mission. Theoretical models suggest that the dust grains on the lunar surface are charged by the solar UV radiation as well as the solar wind. Even without any physical activity, the dust grains are levitated by electrostatic fields and transported away from the surface in the near vacuum environment of the Moon. The current dust charging and the levitation models, however, do not fully explain the observed phenomena. Since the abundance of dust on the Moon's surface with its observed adhesive characteristics is believed to have a severe impact on the human habitat and the lifetime and operations of a variety of equipment, it is necessary to investigate the phenomena and the charging properties of the lunar dust in order to develop appropriate mitigating strategies. We will present results of some recent laboratory experiments on individual micro/sub-micron size dust grains levitated in electrodynamic balance in simulated space environments. The experiments involve photoelectric emission measurements of individual micron size lunar dust grains illuminated with UV radiation in the 120-160 nm wavelength range. The photoelectric yields are required to determine the charging properties of lunar dust illuminated by solar UV radiation. We will present some recent results of laboratory measurement of the photoelectric yields and the physical properties of individual micron size dust grains from the Apollo and Luna-24 sample returns as well as the JSC-1 lunar simulants.

Radiation protection challenges in the management of radioactive waste from high-energy accelerators.

PubMed

Ulrici, Luisa; Algoet, Yvon; Bruno, Luca; Magistris, Matteo

2015-04-01

The European Laboratory for Particle Physics (CERN) has operated high-energy accelerators for fundamental physics research for nearly 60 y. The side-product of this activity is the radioactive waste, which is mainly generated as a result of preventive and corrective maintenance, upgrading activities and the dismantling of experiments or accelerator facilities. Prior to treatment and disposal, it is common practice to temporarily store radioactive waste on CERN's premises and it is a legal requirement that these storage facilities are safe and secure. Waste treatment typically includes sorting, segregation, volume and size reduction and packaging, which will depend on the type of component, its chemical composition, residual activity and possible surface contamination. At CERN, these activities are performed in a dedicated waste treatment centre under the supervision of the Radiation Protection Group. This paper gives an overview of the radiation protection challenges in the conception of a temporary storage and treatment centre for radioactive waste in an accelerator facility, based on the experience gained at CERN. The CERN approach consists of the classification of waste items into 'families' with similar radiological and physical-chemical properties. This classification allows the use of specific, family-dependent techniques for radiological characterisation and treatment, which are simultaneously efficient and compliant with best practices in radiation protection. The storage was planned on the basis of radiological and other possible hazards such as toxicity, pollution and fire load. Examples are given of technical choices for the treatment and radiological characterisation of selected waste families, which could be of interest to other accelerator facilities. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Workshop Physics Activity Guide, Module 3: Heat Temperature and Nuclear Radiation, Thermodynamics, Kinetic Theory, Heat Engines, Nuclear Decay, and Random Monitoring (Units 16 - 18 & 28)

NASA Astrophysics Data System (ADS)

Laws, Priscilla W.

2004-05-01

The Workshop Physics Activity Guide is a set of student workbooks designed to serve as the foundation for a two-semester calculus-based introductory physics course. It consists of 28 units that interweave text materials with activities that include prediction, qualitative observation, explanation, equation derivation, mathematical modeling, quantitative experiments, and problem solving. Students use a powerful set of computer tools to record, display, and analyze data, as well as to develop mathematical models of physical phenomena. The design of many of the activities is based on the outcomes of physics education research.

Single-electron detection and spectroscopy via relativistic cyclotron radiation

DOE PAGES

Asner, D. M.; Bradley, R. F.; de Viveiros, L.; ...

2015-04-20

Since 1897, we've understood that accelerating charges must emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. We demonstrate single-electron detection in a novel radiofrequency spec- trometer. Here, we observe the cyclotron radiation emitted by individual magnetically-trapped electrons that are produced with mildly-relativistic energies by a gaseous radioactive source. The relativistic shift in the cyclotron frequency permits a precisemore » electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work demonstrates a fundamentally new approach to precision beta spectroscopy for future neutrino mass experiments.« less

Results of a comprehensive atmospheric aerosol-radiation experiment in the southwestern United States. I - Size distribution, extinction optical depth and vertical profiles of aerosols suspended in the atmosphere. II - Radiation flux measurements and

NASA Technical Reports Server (NTRS)

Deluisi, J. J.; Furukawa, F. M.; Gillette, D. A.; Schuster, B. G.; Charlson, R. J.; Porch, W. M.; Fegley, R. W.; Herman, B. M.; Rabinoff, R. A.; Twitty, J. T.

1976-01-01

Results are reported for a field test that was aimed at acquiring a sufficient set of measurements of aerosol properties required as input for radiative-transfer calculations relevant to the earth's radiation balance. These measurements include aerosol extinction and size distributions, vertical profiles of aerosols, and radiation fluxes. Physically consistent, vertically inhomogeneous models of the aerosol characteristics of a turbid atmosphere over a desert and an agricultural region are constructed by using direct and indirect sampling techniques. These results are applied for a theoretical interpretation of airborne radiation-flux measurements. The absorption term of the complex refractive index of aerosols is estimated, a regional variation in the refractive index is noted, and the magnitude of solar-radiation absorption by aerosols and atmospheric molecules is determined.

Experiences of incontinence and pelvic floor muscle training after gynaecologic cancer treatment.

PubMed

Lindgren, Anna; Dunberger, G; Enblom, A

2017-01-01

The purpose of the present study is to describe how gynaecological cancer survivors (GCS) experience incontinence in relation to quality of life, their possibilities for physical activity and exercise and their perceptions and experiences of pelvic floor muscle training. This qualitative interview content analysis study included 13 women (48-82 age) with urinary (n = 10) or faecal (n = 3) incontinence after radiation therapy (n = 2), surgery (n = 5) and surgery and radiation therapy (n = 6) for gynaecological cancer, 0.5-21 years ago. Symptoms related to incontinence and restrictions in daily activities reduced physical quality of life. Emotions related to incontinence reduced psychological quality of life and social and existential quality of life, due to restrictions in activity and feelings of exclusion. Practical and mental strategies for maintaining quality of life were described, such as always bringing a change of clothes and accepting the situation. Possibilities for sexual and physical activity as well as exercise were also restricted by incontinence. The women had little or no experience of pelvic floor muscle training but have a positive attitude towards trying it. They also described a lack of information about the risk of incontinence. The women were willing to spend both money and time on an effective treatment for their incontinence. Nine out of 10 were willing to spend at least 7 h a week. GCS experienced that incontinence reduced quality of life and limited possibilities for sexual and physical activity as well as exercise. Coping strategies, both practical and emotional, facilitated living with incontinence. The women had a positive attitude towards pelvic floor muscle training. Lack of information had a negative impact on their way of dealing with the situation.

A Web 2.0 Interface to Ion Stopping Power and Other Physics Routines for High Energy Density Physics Applications

NASA Astrophysics Data System (ADS)

Stoltz, Peter; Veitzer, Seth

2008-04-01

We present a new Web 2.0-based interface to physics routines for High Energy Density Physics applications. These routines include models for ion stopping power, sputtering, secondary electron yields and energies, impact ionization cross sections, and atomic radiated power. The Web 2.0 interface allows users to easily explore the results of the models before using the routines within other codes or to analyze experimental results. We discuss how we used various Web 2.0 tools, including the Python 2.5, Django, and the Yahoo User Interface library. Finally, we demonstrate the interface by showing as an example the stopping power algorithms researchers are currently using within the Hydra code to analyze warm, dense matter experiments underway at the Neutralized Drift Compression Experiment facility at Lawrence Berkeley National Laboratory.

First results from Spacelab 2

NASA Technical Reports Server (NTRS)

Urban, E. W.

1986-01-01

Preliminary results of physical experiments carried out during the Spacelab 2 Shuttle mission are summarized. Attention is given to experiments in the fields of plasma dynamics; solar physics; high-energy astrophysics; and astronomy. Plasma experiments included an ejectable plasma diagnosics package and measurements of the passive charging of the Shuttle vehicle in the surrounding space plasma. The solar physics instrument package consisted of a solar spectral irradiance monitor; a solar optical universal polarimeter (SOUP); and a solar helium abundance high-resolution telescope and spectrograph (HRTS). Astronomical observations were performed using a scanning infrared telescope (IRT) which consisted of a highly baffled herschelian telescope and 10 detectors covering wavelengths from 2 to 120 microns. Cosmic-ray nuclei were detected and analyzed using gas Cerenkov counters and a transition radiation detector. Addition experiments included a thin film fluid dynamics payload and analysis of blood samples taken from the mission specialists. Complete data records from the experiments have now been distributed for an analysis period which will take at least a year. A table listing the Spacelab 2 experiments and their principal investigators is provided.

Exposure to space radiation of high-performance infrared multilayer filters and materials technology experiment (A0056)

NASA Technical Reports Server (NTRS)

Hawkins, Gary J.; Seeley, John S.; Hunneman, Roger

1992-01-01

Infrared optical multilayer filters and materials were exposed to the space environment of low Earth orbit on LDEF. The effects are summarized of that environment on the physical and optical properties of the filters and materials flown.

Radiation testing campaign results for understanding the suitability of FPGAs in detector electronics

DOE PAGES

Citterio, M.; Camplani, A.; Cannon, M.; ...

2015-11-19

SRAM based Field Programmable Gate Arrays (FPGAs) have been rarely used in High Energy Physics (HEP) due to their sensitivity to radiation. The last generation of commercial FPGAs based on 28 nm feature size and on Silicon On Insulator (SOI) technologies are more tolerant to radiation to the level that their use in front-end electronics is now feasible. FPGAs provide re-programmability, high-speed computation and fast data transmission through the embedded serial transceivers. They could replace custom application specific integrated circuits in front end electronics in locations with moderate radiation field. Finally, the use of a FPGA in HEP experiments ismore » only limited by our ability to mitigate single event effects induced by the high energy hadrons present in the radiation field.« less

Simulation of Plasma Jet Merger and Liner Formation within the PLX- α Project

NASA Astrophysics Data System (ADS)

Samulyak, Roman; Chen, Hsin-Chiang; Shih, Wen; Hsu, Scott

2015-11-01

Detailed numerical studies of the propagation and merger of high Mach number argon plasma jets and the formation of plasma liners have been performed using the newly developed method of Lagrangian particles (LP). The LP method significantly improves accuracy and mathematical rigor of common particle-based numerical methods such as smooth particle hydrodynamics while preserving their main advantages compared to grid-based methods. A brief overview of the LP method will be presented. The Lagrangian particle code implements main relevant physics models such as an equation of state for argon undergoing atomic physics transformation, radiation losses in thin optical limit, and heat conduction. Simulations of the merger of two plasma jets are compared with experimental data from past PLX experiments. Simulations quantify the effect of oblique shock waves, ionization, and radiation processes on the jet merger process. Results of preliminary simulations of future PLX- alpha experiments involving the ~ π / 2 -solid-angle plasma-liner configuration with 9 guns will also be presented. Partially supported by ARPA-E's ALPHA program.

The physics behind a simple demonstration of the greenhouse effect

NASA Astrophysics Data System (ADS)

Buxton, Gavin A.

2014-03-01

A simple, and popular, demonstration of the greenhouse effect involves a higher temperature being observed in a container with an elevated concentration of CO2 inside than in a container with just air enclosed, when subject to direct light. The CO2 absorbs outgoing thermal radiation and causes the air inside the container to be warmer. However, in some variations of this experiment an additional positive effect can arise from artefacts in the experiment, such as the slightly heavier CO2 forming a layer at the bottom of the container and suppressing convection. Therefore, the physics of this demonstration is elucidated in a system that does not suffer from such artefacts. In particular, the absorption of infrared radiation due to the enclosed CO2 is measured, and a one-dimensional model of heat transfer is solved. It is found that the temperature of the enclosed air is significantly higher inside the container with an elevated concentration of CO2 inside, but that the temperature of the container itself is not appreciably higher.

KSC-2013-3908

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Dust particles scatter during an experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The fabricated material is designed to mimic the dust on the lunar surface. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities.

KSC-2013-3907

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. -- Dust particles are readied for an experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The fabricated material is designed to mimic the dust on the lunar surface. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities. CAPE CANAVERAL, Fla. -- Preparations are underway to conduct a dust particle experiment for the Electrodynamic Dust Shield for Dust Mitigation project in the Electrostatics and Surface Physics Laboratory in the SwampWorks at NASA's Kennedy Space Center in Florida. The technology works by creating an electric field that propagates out like the ripples on a pond. This could prevent dust accumulation on spacesuits, thermal radiators, solar panels, optical instruments and view ports for future lunar and Mars exploration activities.

Focusing giga-electronvolt heavy ions to micrometers at the Institute of Modern Physics.

PubMed

Sheng, Lina; Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Song, Mingtao; Yuan, Youjin; Xiao, Guoqing

2013-05-01

To study the radiation effect of cosmic heavy ions of low fluxes in electronics and living samples, a focusing heavy ion microbeam facility, for ions with energies of several MeV/u up to 100 MeV/u, was constructed in the Institute of Modern Physics of the Chinese Academy of Sciences. This facility has a vertical design and an experiment platform for both in-vacuum analysis and in-air irradiation. Recently, microbeam of (12)C(6+) with energy of 80.55 MeV/u was successfully achieved at this interdisciplinary microbeam facility with a full beam spot size of 3 μm × 5 μm on target in air. Different from ions with energy of several MeV/u, the very high ion energy of hundred MeV/u level induces problems in beam micro-collimation, online beam spot diagnosis, radiation protection, etc. This paper presents the microbeam setup, difficulties in microbeam formation, and the preliminary experiments performed with the facility.

Essentials and guidelines for clinical medical physics residency training programs: executive summary of AAPM Report Number 249.

PubMed

Prisciandaro, Joann I; Willis, Charles E; Burmeister, Jay W; Clarke, Geoffrey D; Das, Rupak K; Esthappan, Jacqueline; Gerbi, Bruce J; Harkness, Beth A; Patton, James A; Peck, Donald J; Pizzutiello, Robert J; Sandison, George A; White, Sharon L; Wichman, Brian D; Ibbott, Geoffrey S; Both, Stefan

2014-05-08

There is a clear need for established standards for medical physics residency training. The complexity of techniques in imaging, nuclear medicine, and radiation oncology continues to increase with each passing year. It is therefore imperative that training requirements and competencies are routinely reviewed and updated to reflect the changing environment in hospitals and clinics across the country. In 2010, the AAPM Work Group on Periodic Review of Medical Physics Residency Training was formed and charged with updating AAPM Report Number 90. This work group includes AAPM members with extensive experience in clinical, professional, and educational aspects of medical physics. The resulting report, AAPM Report Number 249, concentrates on the clinical and professional knowledge needed to function independently as a practicing medical physicist in the areas of radiation oncology, imaging, and nuclear medicine, and constitutes a revision to AAPM Report Number 90. This manuscript presents an executive summary of AAPM Report Number 249.

Essentials and guidelines for clinical medical physics residency training programs: executive summary of AAPM Report Number 249

PubMed Central

Willis, Charles E.; Burmeister, Jay W.; Clarke, Geoffrey D.; Das, Rupak K.; Esthappan, Jacqueline; Gerbi, Bruce J.; Harkness, Beth A.; Patton, James A.; Peck, Donald J.; Pizzutiello, Robert J.; Sandison, George A.; White, Sharon L.; Wichman, Brian D.; Ibbott, Geoffrey S.; Both, Stefan

2014-01-01

There is a clear need for established standards for medical physics residency training. The complexity of techniques in imaging, nuclear medicine, and radiation oncology continues to increase with each passing year. It is therefore imperative that training requirements and competencies are routinely reviewed and updated to reflect the changing environment in hospitals and clinics across the country. In 2010, the AAPM Work Group on Periodic Review of Medical Physics Residency Training was formed and charged with updating AAPM Report Number 90. This work group includes AAPM members with extensive experience in clinical, professional, and educational aspects of medical physics. The resulting report, AAPM Report Number 249, concentrates on the clinical and professional knowledge needed to function independently as a practicing medical physicist in the areas of radiation oncology, imaging, and nuclear medicine, and constitutes a revision to AAPM Report Number 90. This manuscript presents an executive summary of AAPM Report Number 249. PACS number: 87.10.‐e PMID:24892354

Radiation-induced insulator discharge pulses in the CRRES internal discharge monitor satellite experiment

NASA Technical Reports Server (NTRS)

Frederickson, A. R.; Mullen, E. G.; Brautigam, D. H.; Kerns, K. J.

1992-01-01

The Internal Discharge Monitor (IDM) was designed to observe electrical pulses from common electrical insulators in space service. The sixteen insulator samples included twelve planar printed circuit boards and four cables. The samples were fully enclosed, mutually isolated, and space radiation penetrated 0.02 cm of aluminum before striking the samples. Pulsing began on the seventh orbit, the maximum pulse rate occurred on the seventeenth orbit when 13 pulses occurred, and the pulses slowly diminished to about one per 3 orbits six months later. After 8 months, the radiation belts abruptly increased and the pulse rates attained a new high. These pulse rates were in agreement with laboratory experience on shorter time scales. Several of the samples never pulsed. If the pulses were not confined within IDM, the physical processes could spread to become a full spacecraft anomaly. The IDM results indicate the rate at which small insulator pulses occur. Small pulses are the seeds of larger satellite electrical anomalies. The pulse rates are compared with space radiation intensities, L shell location, and spectral distributions from the radiation spectrometers on the Combined Release and Radiation Effects Satellite.

SU-F-E-12: Elective International Rotations in Medical Physics Residency Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, D; Mundt, A; Einck, J

Purpose: The purpose of this educational program is to motivate talented, intelligent individuals to become stakeholders in the global effort to improve access to radiotherapy. Methods: The need to improve global access to radiotherapy has been clearly established and several organizations are making substantial progress in securing funding and developing plans to achieve this worthwhile goal. The incorporation of elective international rotations in residency programs may provide one possible mechanism to promote and support this future investment. We recently incorporated an elective 1-month international rotation into our CAMPEP accredited Medical Physics residency program, with our first rotation taking place inmore » Vietnam. A unique aspect of this rotation was that it was scheduled collaboratively with our Radiation Oncology residency program such that Radiation Oncology and Medical Physics residents traveled to the same clinic at the same time. Results: We believe the international rotation substantially enhances the educational experience, providing additional benefits to residents by increasing cross-disciplinary learning and offering a shared learning experience. The combined international rotation may also increase benefit to the host institution by modeling positive multidisciplinary working relationships between Radiation Oncologists and Medical Physicists. Our first resident returned with several ideas designed to improve radiotherapy in resource-limited settings – one of which is currently being pursued in collaboration with a vendor. Conclusion: The elective international rotation provides a unique learning experience that has the potential to motivate residents to become stakeholders in the global effort to improve access to radiotherapy. What better way to prepare the next generation of Medical Physicists to meet the challenges of improving global access to radiotherapy than to provide them with training experiences that motivate them to be socially conscious and equip them with the clinical and problem solving skills required to deliver effective treatments in resource limited settings?.« less

Physics-based modeling of live wildland fuel ignition experiments in the Forced Ignition and Flame Spread Test apparatus

Treesearch

C. Anand; B. Shotorban; S. Mahalingam; S. McAllister; D. R. Weise

2017-01-01

A computational study was performed to improve our understanding of the ignition of live fuel in the forced ignition and flame spread test apparatus, a setup where the impact of the heating mode is investigated by subjecting the fuel to forced convection and radiation. An improvement was first made in the physics-based model WFDS where the fuel is treated as fixed...

From Global to Cloud Resolving Scale: Experiments with a Scale- and Aerosol-Aware Physics Package and Impact on Tracer Transport

NASA Astrophysics Data System (ADS)

Grell, G. A.; Freitas, S. R.; Olson, J.; Bela, M.

2017-12-01

We will start by providing a summary of the latest cumulus parameterization modeling efforts at NOAA's Earth System Research Laboratory (ESRL) will be presented on both regional and global scales. The physics package includes a scale-aware parameterization of subgrid cloudiness feedback to radiation (coupled PBL, microphysics, radiation, shallow and congestus type convection), the stochastic Grell-Freitas (GF) scale- and aerosol-aware convective parameterization, and an aerosol aware microphysics package. GF is based on a stochastic approach originally implemented by Grell and Devenyi (2002) and described in more detail in Grell and Freitas (2014, ACP). It was expanded to include PDF's for vertical mass flux, as well as modifications to improve the diurnal cycle. This physics package will be used on different scales, spanning global to cloud resolving, to look at the impact on scalar transport and numerical weather prediction.

Aerosol physical properties from satellite horizon inversion

NASA Technical Reports Server (NTRS)

Gray, C. R.; Malchow, H. L.; Merritt, D. C.; Var, R. E.; Whitney, C. K.

1973-01-01

The feasibility is investigated of determining the physical properties of aerosols globally in the altitude region of 10 to 100 km from a satellite horizon scanning experiment. The investigation utilizes a horizon inversion technique previously developed and extended. Aerosol physical properties such as number density, size distribution, and the real and imaginary components of the index of refraction are demonstrated to be invertible in the aerosol size ranges (0.01-0.1 microns), (0.1-1.0 microns), (1.0-10 microns). Extensions of previously developed radiative transfer models and recursive inversion algorithms are displayed.

The creation of radiation dominated plasmas using laboratory extreme ultra-violet lasers

NASA Astrophysics Data System (ADS)

Tallents, G. J.; Wilson, S.; West, A.; Aslanyan, V.; Lolley, J.; Rossall, A. K.

2017-06-01

Ionization in experiments where solid targets are irradiated by high irradiance extreme ultra-violet (EUV) lasers is examined. Free electron degeneracy effects on ionization in the presence of a high EUV flux of radiation is shown to be important. Overlap of the physics of such plasmas with plasma material under compression in indirect inertial fusion is explored. The design of the focusing optics needed to achieve high irradiance (up to 1014 Wcm-2) using an EUV capillary laser is presented.

Hadron therapy: history, status, prospects

NASA Astrophysics Data System (ADS)

Klenov, G. I.; Khoroshkov, V. S.

2016-08-01

A brief historical review is given of external radiation therapy (RT), one of the main cancer treatment methods along with surgery and chemotherapy. Cellular mechanisms of radiation damage are described. Special attention is paid to hadron (proton and ion) therapy, its history, results, problems, challenges, current trends, and prospects. Undeniably great contributions to proton therapy have been made by Russian researchers, notably at the experimental centers that have operated since the mid-20th century at the Joint Institute for Nuclear Research, the A I Alikhanov Institute for Theoretical and Experimental Physics (ITEP), and the B P Konstantinov Petersburg Institute of Nuclear Physics. A quarter of the global clinical experience was accumulated by 1990 at the world's largest ITEP-hosted multicabin proton therapy center.

Experiments and Demonstrations in Physics: Bar-Ilan Physics Laboratory (2nd Edition)

NASA Astrophysics Data System (ADS)

Kraftmakher, Yaakov

2014-08-01

The following sections are included: * Data-acquisition systems from PASCO * ScienceWorkshop 750 Interface and DataStudio software * 850 Universal Interface and Capstone software * Mass on spring * Torsional pendulum * Hooke's law * Characteristics of DC source * Digital storage oscilloscope * Charging and discharging a capacitor * Charge and energy stored in a capacitor * Speed of sound in air * Lissajous patterns * I-V characteristics * Light bulb * Short time intervals * Temperature measurements * Oersted's great discovery * Magnetic field measurements * Magnetic force * Magnetic braking * Curie's point I * Electric power in AC circuits * Faraday's law of induction I * Self-inductance and mutual inductance * Electromagnetic screening * LCR circuit I * Coupled LCR circuits * Probability functions * Photometric laws * Kirchhoff's rule for thermal radiation * Malus' law * Infrared radiation * Irradiance and illuminance

Radiation forces and the Abraham-Minkowski problem

NASA Astrophysics Data System (ADS)

Brevik, Iver

2018-04-01

Recent years have witnessed a number of beautiful experiments in radiation optics. Our purpose with this paper is to highlight some developments of radiation pressure physics in general, and thereafter to focus on the importance of the mentioned experiments in regard to the classic Abraham-Minkowski problem. That means, what is the “correct” expression for electromagnetic momentum density in continuous matter. In our opinion, one often sees that authors over-interpret the importance of their experimental findings with respect to the momentum problem. Most of these experiments are actually unable to discriminate between these energy-momentum tensors at all, since they can be easily described in terms of force expressions that are common for Abraham and Minkowski. Moreover, we emphasize the inherent ambiguity in applying the formal conservation principles to the radiation field in a dielectric, the reason being that the electromagnetic field in matter is only a subsystem which has to be supplemented by the mechanical subsystem to be closed. Finally, we make some suggestions regarding the connection between macroscopic electrodynamics and the Casimir effect, suggesting that there is a limit for the magnitudes of the cutoff parameters in QFT related to surface tension in ordinary hydromechanics.

How much can we learn about the physics of inflation?

PubMed

Dodelson, Scott

2014-05-16

The recent BICEP2 measurement of B modes in the polarization of the cosmic microwave background suggests that inflation was driven by a field at an energy scale of 2 × 10(16) GeV. I explore the potential of upcoming cosmic microwave radiation polarization experiments to further constrain the physics underlying inflation. If the signal is confirmed, then two sets of experiments covering a large area will shed light on inflation. Low-resolution measurements can pin down the tensor to scalar ratio at the percent level, thereby distinguishing models from one another. A high angular resolution experiment will be necessary to measure the tilt of the tensor spectrum, testing the consistency relation that relates the tilt to the amplitude.

Heat and moisture fluxes within a nighttime maritime stratus cloud during CASP II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gultepe, I.; Issac, G.

Stratus clouds in the lower part of the atmosphere over the ocean or land can play an important role in boundary layer processes and in climate change. Physical, dynamical, and radiative processes within marine stratus clouds on both cloud and regional scale are studied for the first time during the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE) (Albrecht et al., 1988). These clouds can effect the nowcasting, pollution transfer, and radiative processes (Nicholls and Leighton, 1986). Similar to the FIRE stratus project, the Canadian Atlantic Storms Program (CASP) II field project was planned to obtain a bettermore » understanding of cloud physical, dynamical, radiative characteristics, and mesoscale structure of Canadian east coast storms. Here the dynamical and microphysical data, and a radiative transfer model are used to better understand a developing nighttime stratus cloud over the ocean during CASP II which took place over Atlantic Canada. Observations collected by the Convair aircraft of the National Research Council (NRC) of Canada during the CASP II field project on February 6, 1991 are presented.« less

Radiation Brain Drain? The Impact of Demographic Change on U.S. Radiation Protection.

PubMed

Hricak, Hedvig; Dauer, Lawrence T

2017-02-01

The use of radiation has a substantial beneficial impact, particularly in the areas of medicine, energy production, basic science research, and industrial applications. Radiation protection knowledge and experience are required for acquiring and implementing scientific knowledge to protect workers, members of the public, and the environment from potential harmful effects of ionizing radiation while facilitating the beneficial use and development of radiation-based technologies. However, demographic changes are negatively impacting U.S. radiation protection and response capabilities. The number of radiation professionals continues to decrease even as the demand for such professionals is growing. These concerns are most pronounced in the medical, energy, research, and security arenas. Though the United States has been the world leader in radiation protection and radiation sciences for many years, the country has no strategic plan to ensure the maintenance of expertise in radiobiology, radiation physics, and radiation protection. Solving this problem will require a significant increase in federal and state funding as well as formal partnerships and initiatives among academia, professional societies, government, and the private sector.

The HIRLAM fast radiation scheme for mesoscale numerical weather prediction models

NASA Astrophysics Data System (ADS)

Rontu, Laura; Gleeson, Emily; Räisänen, Petri; Pagh Nielsen, Kristian; Savijärvi, Hannu; Hansen Sass, Bent

2017-07-01

This paper provides an overview of the HLRADIA shortwave (SW) and longwave (LW) broadband radiation schemes used in the HIRLAM numerical weather prediction (NWP) model and available in the HARMONIE-AROME mesoscale NWP model. The advantage of broadband, over spectral, schemes is that they can be called more frequently within the model, without compromising on computational efficiency. In mesoscale models fast interactions between clouds and radiation and the surface and radiation can be of greater importance than accounting for the spectral details of clear-sky radiation; thus calling the routines more frequently can be of greater benefit than the deterioration due to loss of spectral details. Fast but physically based radiation parametrizations are expected to be valuable for high-resolution ensemble forecasting, because as well as the speed of their execution, they may provide realistic physical perturbations. Results from single-column diagnostic experiments based on CIRC benchmark cases and an evaluation of 10 years of radiation output from the FMI operational archive of HIRLAM forecasts indicate that HLRADIA performs sufficiently well with respect to the clear-sky downwelling SW and longwave LW fluxes at the surface. In general, HLRADIA tends to overestimate surface fluxes, with the exception of LW fluxes under cold and dry conditions. The most obvious overestimation of the surface SW flux was seen in the cloudy cases in the 10-year comparison; this bias may be related to using a cloud inhomogeneity correction, which was too large. According to the CIRC comparisons, the outgoing LW and SW fluxes at the top of atmosphere are mostly overestimated by HLRADIA and the net LW flux is underestimated above clouds. The absorption of SW radiation by the atmosphere seems to be underestimated and LW absorption seems to be overestimated. Despite these issues, the overall results are satisfying and work on the improvement of HLRADIA for the use in HARMONIE-AROME NWP system is ongoing. In a HARMONIE-AROME 3-D forecast experiment we have shown that the frequency of the call for the radiation parametrization and choice of the parametrization scheme makes a difference to the surface radiation fluxes and changes the spatial distribution of the vertically integrated cloud cover and precipitation.

Zemax simulations describing collective effects in transition and diffraction radiation.

PubMed

Bisesto, F G; Castellano, M; Chiadroni, E; Cianchi, A

2018-02-19

Transition and diffraction radiation from charged particles is commonly used for diagnostics purposes in accelerator facilities as well as THz sources for spectroscopy applications. Therefore, an accurate analysis of the emission process and the transport optics is crucial to properly characterize the source and precisely retrieve beam parameters. In this regard, we have developed a new algorithm, based on Zemax, to simulate both transition and diffraction radiation as generated by relativistic electron bunches, therefore considering collective effects. In particular, unlike other previous works, we take into account electron beam physical size and transverse momentum, reproducing some effects visible on the produced radiation, not observable in a single electron analysis. The simulation results have been compared with two experiments showing an excellent agreement.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Citterio, M.; Camplani, A.; Cannon, M.

SRAM based Field Programmable Gate Arrays (FPGAs) have been rarely used in High Energy Physics (HEP) due to their sensitivity to radiation. The last generation of commercial FPGAs based on 28 nm feature size and on Silicon On Insulator (SOI) technologies are more tolerant to radiation to the level that their use in front-end electronics is now feasible. FPGAs provide re-programmability, high-speed computation and fast data transmission through the embedded serial transceivers. They could replace custom application specific integrated circuits in front end electronics in locations with moderate radiation field. Finally, the use of a FPGA in HEP experiments ismore » only limited by our ability to mitigate single event effects induced by the high energy hadrons present in the radiation field.« less

Radiation Oncology Medical Student Clerkship: Implementation and Evaluation of a Bi-institutional Pilot Curriculum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golden, Daniel W., E-mail: dgolden@radonc.uchicago.edu; Spektor, Alexander; Rudra, Sonali

Purpose: To develop and evaluate a structured didactic curriculum to complement clinical experiences during radiation oncology clerkships at 2 academic medical centers. Methods and Materials: A structured didactic curriculum was developed to teach fundamentals of radiation oncology and improve confidence in clinical competence. Curriculum lectures included: (1) an overview of radiation oncology (history, types of treatments, and basic clinic flow); (2) fundamentals of radiation biology and physics; and (3) practical aspects of radiation treatment simulation and planning. In addition, a hands-on dosimetry session taught students fundamentals of treatment planning. The curriculum was implemented at 2 academic departments in 2012. Studentsmore » completed anonymous evaluations using a Likert scale to rate the usefulness of curriculum components (1 = not at all, 5 = extremely). Likert scores are reported as (median [interquartile range]). Results: Eighteen students completed the curriculum during their 4-week rotation (University of Chicago n=13, Harvard Longwood Campus n=5). All curriculum components were rated as extremely useful: introduction to radiation oncology (5 [4-5]); radiation biology and physics (5 [5-5]); practical aspects of radiation oncology (5 [4-5]); and the treatment planning session (5 [5-5]). Students rated the curriculum as “quite useful” to “extremely useful” (1) to help students understand radiation oncology as a specialty; (2) to increase student comfort with their specialty decision; and (3) to help students with their future transition to a radiation oncology residency. Conclusions: A standardized curriculum for medical students completing a 4-week radiation oncology clerkship was successfully implemented at 2 institutions. The curriculum was favorably reviewed. As a result of completing the curriculum, medical students felt more comfortable with their specialty decision and better prepared to begin radiation oncology residency.« less

Test beam studies of possibilities to separate particles with gamma factors above 103 with straw based Transition Radiation Detector

NASA Astrophysics Data System (ADS)

Belyaev, N.; Cherry, M. L.; Doronin, S. A.; Filippov, K.; Fusco, P.; Konovalov, S.; Krasnopevtsev, D.; Kramarenko, V.; Loparco, F.; Mazziotta, M. N.; Ponomarenko, D.; Pyatiizbyantseva, D.; Radomskii, R.; Rembser, C.; Romaniouk, A.; Savchenko, A.; Shulga, E.; Smirnov, S.; Smirnov, Yu; Sosnovtsev, V.; Spinelli, P.; Teterin, P.; Tikhomirov, V.; Vorobev, K.; Zhukov, K.

2017-12-01

Measurements of hadron production in the TeV energy range are one of the tasks of the future studies at the Large Hadron Collider (LHC). The main goal of these experiments is a study of the fundamental QCD processes at this energy range, which is very important not only for probing of the Standard Model but also for ultrahigh-energy cosmic particle physics. One of the key elements of these experiments measurements are hadron identification. The only detector technology which has a potential ability to separate hadrons in this energy range is Transition Radiation Detector (TRD) technology. TRD prototype based on straw proportional chambers combined with a specially assembled radiator has been tested at the CERN SPS accelerator beam. The test beam results and comparison with detailed Monte Carlo simulations are presented here.

Development of the Code RITRACKS

NASA Technical Reports Server (NTRS)

Plante, Ianik; Cucinotta, Francis A.

2013-01-01

A document discusses the code RITRACKS (Relativistic Ion Tracks), which was developed to simulate heavy ion track structure at the microscopic and nanoscopic scales. It is a Monte-Carlo code that simulates the production of radiolytic species in water, event-by-event, and which may be used to simulate tracks and also to calculate dose in targets and voxels of different sizes. The dose deposited by the radiation can be calculated in nanovolumes (voxels). RITRACKS allows simulation of radiation tracks without the need of extensive knowledge of computer programming or Monte-Carlo simulations. It is installed as a regular application on Windows systems. The main input parameters entered by the user are the type and energy of the ion, the length and size of the irradiated volume, the number of ions impacting the volume, and the number of histories. The simulation can be started after the input parameters are entered in the GUI. The number of each kind of interactions for each track is shown in the result details window. The tracks can be visualized in 3D after the simulation is complete. It is also possible to see the time evolution of the tracks and zoom on specific parts of the tracks. The software RITRACKS can be very useful for radiation scientists to investigate various problems in the fields of radiation physics, radiation chemistry, and radiation biology. For example, it can be used to simulate electron ejection experiments (radiation physics).

The Role of Laboratory-Based Studies of the Physical and Biological Properties of Sea Ice in Supporting the Observation and Modeling of Ice Covered Seas

NASA Astrophysics Data System (ADS)

Light, B.; Krembs, C.

2003-12-01

Laboratory-based studies of the physical and biological properties of sea ice are an essential link between high latitude field observations and existing numerical models. Such studies promote improved understanding of climatic variability and its impact on sea ice and the structure of ice-dependent marine ecosystems. Controlled laboratory experiments can help identify feedback mechanisms between physical and biological processes and their response to climate fluctuations. Climatically sensitive processes occurring between sea ice and the atmosphere and sea ice and the ocean determine surface radiative energy fluxes and the transfer of nutrients and mass across these boundaries. High temporally and spatially resolved analyses of sea ice under controlled environmental conditions lend insight to the physics that drive these transfer processes. Techniques such as optical probing, thin section photography, and microscopy can be used to conduct experiments on natural sea ice core samples and laboratory-grown ice. Such experiments yield insight on small scale processes from the microscopic to the meter scale and can be powerful interdisciplinary tools for education and model parameterization development. Examples of laboratory investigations by the authors include observation of the response of sea ice microstructure to changes in temperature, assessment of the relationships between ice structure and the partitioning of solar radiation by first-year sea ice covers, observation of pore evolution and interfacial structure, and quantification of the production and impact of microbial metabolic products on the mechanical, optical, and textural characteristics of sea ice.

Kinetic and radiation-hydrodynamic modeling of x-ray heating in laboratory photoionized plasmas

NASA Astrophysics Data System (ADS)

Mancini, Roberto

2017-06-01

In experiments performed at the Z facility of Sandia National Laboratories a cm-scale cell filled with neon gas was driven by the burst of broadband x-rays emitted at the collapse of a wire-array z-pinch turning the gas into a photoionized plasma. Transmission spectroscopy of a narrowband portion of the x-ray flux was used to diagnose the plasma. The data show a highly-ionized neon plasma with a rich line absorption spectrum that permits the extraction of the ionization distribution among Be-, Li-, He- and H-like ions. Analysis of the spectra produced atomic ground and low excited state areal densities in these ions, and from the ratio of first-excited to ground state populations in Li-like neon a temperature of 19±4eV was extracted to characterize the x-ray heating of the plasma. To interpret this observation, we have performed data-constrained view-factor calculations of the spectral distribution of the x-ray drive, self-consistent modeling of electron and atomic kinetics, and radiation-hydrodynamic simulations. For the conditions of the experiment, the electron distribution thermalizes quickly, has a negligible high-energy tail, and is very well approximated by a single Maxwellian distribution. Radiation-hydrodynamic simulations with either LTE or NLTE (i.e. non-equilibrium) atomic physics provide a more complete modeling of the experiment. We found that in order to compute electron temperatures consistent with observation inline non-equilibrium collisional-radiative neon atomic kinetics needs to be taken into account. We discuss the details of LTE and NLTE simulations, and the impact of atomic physics on the radiation heating and cooling rates that determine the plasma temperature. This work was sponsored in part by DOE Office of Science Grant DE-SC0014451, and the Z Facility Fundamental Science Program of SNL.

SU-A-210-02: Medical Physics Opportunities at the NRC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abogunde, M.

The purpose of this student annual meeting is to address topics that are becoming more relevant to medical physicists, but are not frequently addressed, especially for students and trainees just entering the field. The talk is divided into two parts: medical billing and regulations. Hsinshun Wu – Why should we learn radiation oncology billing? Many medical physicists do not like to be involved with medical billing or coding during their career. They believe billing is not their responsibility and sometimes they even refuse to participate in the billing process if given the chance. This presentation will talk about a physicist’smore » long career and share his own experience that knowing medical billing is not only important and necessary for every young medical physicist, but that good billing knowledge could provide a valuable contribution to his/her medical physics development. Learning Objectives: The audience will learn the basic definition of Current Procedural Terminology (CPT) codes performed in a Radiation Oncology Department. Understand the differences between hospital coding and physician-based or freestanding coding. Apply proper CPT coding for each Radiation Oncology procedure. Each procedure with its specific CPT code will be discussed in detail. The talk will focus on the process of care and use of actual workflow to understand each CPT code. Example coding of a typical Radiation Oncology procedure. Special procedure coding such as brachytherapy, proton therapy, radiosurgery, and SBRT. Maryann Abogunde – Medical physics opportunities at the Nuclear Regulatory Commission (NRC) The NRC’s responsibilities include the regulation of medical uses of byproduct (radioactive) materials and oversight of medical use end-users (licensees) through a combination of regulatory requirements, licensing, safety oversight including inspection and enforcement, operational experience evaluation, and regulatory support activities. This presentation will explore the career options for medical physicists in the NRC, how the NRC interacts with clinical medical physicists, and a physicist’s experience as a regulator. Learning Objectives: Explore non-clinical career pathways for medical physics students and trainees at the Nuclear Regulatory Commission. Overview of NRC medical applications and medical use regulations. Understand the skills needed for physicists as regulators. Abogunde is funded to attend the meeting by her employer, the NRC.« less

SU-A-210-00: AAPM Medical Physics Student Meeting: Medical Billing and Regulations: Everything You Always Wanted To Know, But Were Too Afraid To Ask

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The purpose of this student annual meeting is to address topics that are becoming more relevant to medical physicists, but are not frequently addressed, especially for students and trainees just entering the field. The talk is divided into two parts: medical billing and regulations. Hsinshun Wu – Why should we learn radiation oncology billing? Many medical physicists do not like to be involved with medical billing or coding during their career. They believe billing is not their responsibility and sometimes they even refuse to participate in the billing process if given the chance. This presentation will talk about a physicist’smore » long career and share his own experience that knowing medical billing is not only important and necessary for every young medical physicist, but that good billing knowledge could provide a valuable contribution to his/her medical physics development. Learning Objectives: The audience will learn the basic definition of Current Procedural Terminology (CPT) codes performed in a Radiation Oncology Department. Understand the differences between hospital coding and physician-based or freestanding coding. Apply proper CPT coding for each Radiation Oncology procedure. Each procedure with its specific CPT code will be discussed in detail. The talk will focus on the process of care and use of actual workflow to understand each CPT code. Example coding of a typical Radiation Oncology procedure. Special procedure coding such as brachytherapy, proton therapy, radiosurgery, and SBRT. Maryann Abogunde – Medical physics opportunities at the Nuclear Regulatory Commission (NRC) The NRC’s responsibilities include the regulation of medical uses of byproduct (radioactive) materials and oversight of medical use end-users (licensees) through a combination of regulatory requirements, licensing, safety oversight including inspection and enforcement, operational experience evaluation, and regulatory support activities. This presentation will explore the career options for medical physicists in the NRC, how the NRC interacts with clinical medical physicists, and a physicist’s experience as a regulator. Learning Objectives: Explore non-clinical career pathways for medical physics students and trainees at the Nuclear Regulatory Commission. Overview of NRC medical applications and medical use regulations. Understand the skills needed for physicists as regulators. Abogunde is funded to attend the meeting by her employer, the NRC.« less

Wave-Particle Interactions in the Radiation Belts, Aurora,and Solar Wind: Opportunities for Lab Experiments

NASA Astrophysics Data System (ADS)

Kletzing, C.

2017-12-01

The physics of the creation, loss, and transport of radiation belt particles is intimately connected to the electric and magnetic fields which mediate these processes. A large range of field and particle interactions are involved in this physics from large-scale ring current ion and magnetic field dynamics to microscopic kinetic interactions of whistler-mode chorus waves with energetic electrons. To measure these kinds of radiation belt interactions, NASA implemented the two-satellite Van Allen Probes mission. As part of the mission, the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) investigation is an integrated set of instruments consisting of a triaxial fluxgate magnetometer (MAG) and a Waves instrument which includes a triaxial search coil magnetometer (MSC). We show a variety of waves thought to be important for wave particle interactionsin the radiation belts: low frequency ULF pulsations, EMIC waves, and whistler mode waves including upper and lower band chorus. Outside ofthe radiation belts, Alfven waves play a key role in both solar wind turbulenceand auroral particle acceleration. Several of these wave modes could benefit (or have benefitted) from laboratory studies to further refineour understanding of the detailed physics of the wave-particle interactionswhich lead to energization, pitch angle scattering, and cross-field transportWe illustrate some of the processes and compare the wave data with particle measurements to show relationships between wave activity and particle processobserved in the inner magnetosphere and heliosphere.

Aerothermal modeling program, phase 1

NASA Technical Reports Server (NTRS)

Sturgess, G. J.

1983-01-01

The physical modeling embodied in the computational fluid dynamics codes is discussed. The objectives were to identify shortcomings in the models and to provide a program plan to improve the quantitative accuracy. The physical models studied were for: turbulent mass and momentum transport, heat release, liquid fuel spray, and gaseous radiation. The approach adopted was to test the models against appropriate benchmark-quality test cases from experiments in the literature for the constituent flows that together make up the combustor real flow.

Microdosimetry in ion-beam therapy

NASA Astrophysics Data System (ADS)

Magrin, Giulio; Mayer, Ramona

2015-06-01

The information of the dose is not sufficiently describing the biological effects of ions on tissue since it does not express the radiation quality, i.e. the heterogeneity of the processes due to the slowing-down and the fragmentation of the particles when crossing a target. Depending on different circumstances, the radiation quality can be determined using measurements, calculations, or simulations. Microdosimeters are the primary tools used to provide the experimental information of the radiation quality and their role is becoming crucial for the recent clinical developments in particular with carbon ion therapy. Microdosimetry is strongly linked to the biological effectiveness of the radiation since it provides the physical parameters which explicitly distinguish the radiation for its capability of damaging cells. In the framework of ion-beam therapy microdosimetry can be used in the preparation of the treatment to complement radiobiological experiments and to analyze the modification of the radiation quality in phantoms. A more ambitious goal is to perform the measurements during the irradiation procedure to determine the non-targeted radiation and, more importantly, to monitor the modification of the radiation quality inside the patient. These procedures provide the feedback of the treatment directly beneficial for the single patient but also for the characterization of the biological effectiveness in general with advantages for all future treatment. Traditional and innovative tools are currently under study and an outlook of present experience and future development is presented here.

Probing Planck's Law at Home

ERIC Educational Resources Information Center

Bonnet, I.; Gabelli, J.

2010-01-01

We report on the physics around an incandescent lamp. Using a consumer-grade digital camera, we combine electrical and optical measurements to explore Planck's law of black-body radiation. This simple teaching experiment is successfully used to measure both Stefan's and Planck's constants. Our measurements lead to a strikingly accurate value for…

Nanoscale TiO₂-coated LPGs as radiation-tolerant humidity sensors for high-energy physics applications.

PubMed

Consales, Marco; Berruti, Gaia; Borriello, Anna; Giordano, Michele; Buontempo, Salvatore; Breglio, Giovanni; Makovec, Alajos; Petagna, Paolo; Cusano, Andrea

2014-07-15

This Letter deals with a feasibility analysis for the development of radiation-tolerant fiber-optic humidity sensors based on long-period grating (LPG) technology to be applied in high-energy physics (HEP) experiments currently running at the European Organization for Nuclear Research (CERN). In particular, here we propose a high-sensitivity LPG sensor coated with a finely tuned titanium dioxide (TiO₂) thin layer (~100 nm thick) through the solgel deposition method. Relative humidity (RH) monitoring in the range 0%-75% and at four different temperatures (in the range -10°C-25°C) was carried out to assess sensor performance in real operative conditions required in typical experiments running at CERN. Experimental results demonstrate the very high RH sensitivities of the proposed device (up to 1.4 nm/% RH in correspondence to very low humidity levels), which turned out to be from one to three orders of magnitude higher than those exhibited by fiber Bragg grating sensors coated with micrometer-thin polyimide overlays. The radiation tolerance capability of the TiO₂-coated LPG sensor is also investigated by comparing the sensing performance before and after its exposure to a 1 Mrad dose of γ-ionizing radiation. Overall, the results collected demonstrate the strong potential of the proposed technology with regard to its future exploitation in HEP applications as a robust and valid alternative to the commercial (polymer-based) hygrometers currently used.

Exposures involving perturbations of the EM field have non-linear effects on radiation response and can alter the expression of radiation induced bystander effects

NASA Astrophysics Data System (ADS)

Mothersill, Carmel; Seymour, Colin

2012-07-01

Our recent data suggest there is a physical component to the bystander signal induced by radiation exposure and that alternative medicine techniques such as Reiki and acupuncture or exposures to weak EM fields alter the response of cells to direct irradiation and either altered bystander signal production or altered the response of cells receiving bystander signals. Our proposed mechanism to explain these findings is that perturbation of electromagnetic (EM) fields is central to the induction of low radiation dose responses especially non-targeted bystander effects. In this presentation we review the alternative medicine data and other data sets from our laboratory which test our hypothesis that perturbation of bio-fields will modulate radiation response in the low dose region. The other data sets include exposure to MRI, shielding using lead and or Faraday cages, the use of physical barriers to bystander signal transmission and the use of membrane channel blockers. The data taken together strongly suggest that EM field perturbation can modulate low dose response and that in fact the EM field rather than the targeted deposition of ionizing energy in the DNA may be the key determinant of dose response in a cell or organism The results also lead us to suspect that at least when chemical transmission is blocked, bystander signals can be transmitted by other means. Our recent experiments suggest light signals and volatiles are not likely. We conclude that alternative medicine and other techniques involving electromagnetic perturbations can modify the response of cells to low doses of ionizing radiation and can induce bystander effects similar to those seen in medium transfer experiments. In addition to the obvious implications for mechanistic studies of low dose effects, this could perhaps provide a novel target to exploit in space radiation protection and in optimizing therapeutic gain during radiotherapy.

SU-A-210-01: Why Should We Learn Radiation Oncology Billing?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, H.

The purpose of this student annual meeting is to address topics that are becoming more relevant to medical physicists, but are not frequently addressed, especially for students and trainees just entering the field. The talk is divided into two parts: medical billing and regulations. Hsinshun Wu – Why should we learn radiation oncology billing? Many medical physicists do not like to be involved with medical billing or coding during their career. They believe billing is not their responsibility and sometimes they even refuse to participate in the billing process if given the chance. This presentation will talk about a physicist’smore » long career and share his own experience that knowing medical billing is not only important and necessary for every young medical physicist, but that good billing knowledge could provide a valuable contribution to his/her medical physics development. Learning Objectives: The audience will learn the basic definition of Current Procedural Terminology (CPT) codes performed in a Radiation Oncology Department. Understand the differences between hospital coding and physician-based or freestanding coding. Apply proper CPT coding for each Radiation Oncology procedure. Each procedure with its specific CPT code will be discussed in detail. The talk will focus on the process of care and use of actual workflow to understand each CPT code. Example coding of a typical Radiation Oncology procedure. Special procedure coding such as brachytherapy, proton therapy, radiosurgery, and SBRT. Maryann Abogunde – Medical physics opportunities at the Nuclear Regulatory Commission (NRC) The NRC’s responsibilities include the regulation of medical uses of byproduct (radioactive) materials and oversight of medical use end-users (licensees) through a combination of regulatory requirements, licensing, safety oversight including inspection and enforcement, operational experience evaluation, and regulatory support activities. This presentation will explore the career options for medical physicists in the NRC, how the NRC interacts with clinical medical physicists, and a physicist’s experience as a regulator. Learning Objectives: Explore non-clinical career pathways for medical physics students and trainees at the Nuclear Regulatory Commission. Overview of NRC medical applications and medical use regulations. Understand the skills needed for physicists as regulators. Abogunde is funded to attend the meeting by her employer, the NRC.« less

History of Medical Physics.

ERIC Educational Resources Information Center

Laughlin, John S.

1983-01-01

Traces the development of basic radiation physics that underlies much of today's medical physics and looks separately at the historical development of two major subfields of medical physics: radiation therapy and nuclear medicine. Indicates that radiation physics has made important contributions to solving biomedical problems in medical…

Utilizing plasma physics to create biomolecular movies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hau-Riege, S

In spring of 2000, the LCLS Scientific Advisory Committee selected the top scientific experiments for LCLS. One of the proposed flagship experiments is atomic-resolution three-dimensional structure determination of isolated biolgical macromolecules and particles, with the ultimate goal of obtaining molecular (snapshot) movies. The key enabling insight was that radiation damage may be overcome by using x-ray pulses that are shorter than the time it takes for damage to manifest itself.

The Physics of Energy

NASA Astrophysics Data System (ADS)

Jaffe, Robert L.; Taylor, Washington

2018-01-01

Part I. Basic Energy Physics and Uses: 1. Introduction; 2. Mechanical energy; 3. Electromagnetic energy; 4. Waves and light; 5. Thermodynamics I: heat and thermal energy; 6. Heat transfer; 7. Introduction to quantum physics; 8. Thermodynamics II: entropy and temperature; 9. Energy in matter; 10. Thermal energy conversion; 11. Internal combustion engines; 12. Phase-change energy conversion; 13. Thermal power and heat extraction cycles; Part II. Energy Sources: 14. The forces of nature; 15. Quantum phenomena in energy systems; 16. An overview of nuclear power; 17. Structure, properties and decays of nuclei; 18. Nuclear energy processes: fission and fusion; 19. Nuclear fission reactors and nuclear fusion experiments; 20. Ionizing radiation; 21. Energy in the universe; 22. Solar energy: solar production and radiation; 23. Solar energy: solar radiation on Earth; 24. Solar thermal energy; 25. Photovoltaic solar cells; 26. Biological energy; 27. Ocean energy flow; 28. Wind: a highly variable resource; 29. Fluids – the basics; 30. Wind turbines; 31. Energy from moving water: hydro, wave, tidal, and marine current power; 32. Geothermal energy; 33. Fossil fuels; Part III. Energy System Issues and Externalities: 34. Energy and climate; 35. Earth's climate: past, present, and future; 36. Energy efficiency, conservation, and changing energy sources; 37. Energy storage; 38. Electricity generation and transmission.

A virtual environment for medical radiation collaborative learning.

PubMed

Bridge, Pete; Trapp, Jamie V; Kastanis, Lazaros; Pack, Darren; Parker, Jacqui C

2015-06-01

A software-based environment was developed to provide practical training in medical radiation principles and safety. The Virtual Radiation Laboratory application allowed students to conduct virtual experiments using simulated diagnostic and radiotherapy X-ray generators. The experiments were designed to teach students about the inverse square law, half value layer and radiation protection measures and utilised genuine clinical and experimental data. Evaluation of the application was conducted in order to ascertain the impact of the software on students' understanding, satisfaction and collaborative learning skills and also to determine potential further improvements to the software and guidelines for its continued use. Feedback was gathered via an anonymous online survey consisting of a mixture of Likert-style questions and short answer open questions. Student feedback was highly positive with 80 % of students reporting increased understanding of radiation protection principles. Furthermore 72 % enjoyed using the software and 87 % of students felt that the project facilitated collaboration within small groups. The main themes arising in the qualitative feedback comments related to efficiency and effectiveness of teaching, safety of environment, collaboration and realism. Staff and students both report gains in efficiency and effectiveness associated with the virtual experiments. In addition students particularly value the visualisation of "invisible" physical principles and increased opportunity for experimentation and collaborative problem-based learning. Similar ventures will benefit from adopting an approach that allows for individual experimentation while visualizing challenging concepts.

SU-A-210-04: Panel Discussion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanford, J.

The purpose of this student annual meeting is to address topics that are becoming more relevant to medical physicists, but are not frequently addressed, especially for students and trainees just entering the field. The talk is divided into two parts: medical billing and regulations. Hsinshun Wu – Why should we learn radiation oncology billing? Many medical physicists do not like to be involved with medical billing or coding during their career. They believe billing is not their responsibility and sometimes they even refuse to participate in the billing process if given the chance. This presentation will talk about a physicist’smore » long career and share his own experience that knowing medical billing is not only important and necessary for every young medical physicist, but that good billing knowledge could provide a valuable contribution to his/her medical physics development. Learning Objectives: The audience will learn the basic definition of Current Procedural Terminology (CPT) codes performed in a Radiation Oncology Department. Understand the differences between hospital coding and physician-based or freestanding coding. Apply proper CPT coding for each Radiation Oncology procedure. Each procedure with its specific CPT code will be discussed in detail. The talk will focus on the process of care and use of actual workflow to understand each CPT code. Example coding of a typical Radiation Oncology procedure. Special procedure coding such as brachytherapy, proton therapy, radiosurgery, and SBRT. Maryann Abogunde – Medical physics opportunities at the Nuclear Regulatory Commission (NRC) The NRC’s responsibilities include the regulation of medical uses of byproduct (radioactive) materials and oversight of medical use end-users (licensees) through a combination of regulatory requirements, licensing, safety oversight including inspection and enforcement, operational experience evaluation, and regulatory support activities. This presentation will explore the career options for medical physicists in the NRC, how the NRC interacts with clinical medical physicists, and a physicist’s experience as a regulator. Learning Objectives: Explore non-clinical career pathways for medical physics students and trainees at the Nuclear Regulatory Commission. Overview of NRC medical applications and medical use regulations. Understand the skills needed for physicists as regulators. Abogunde is funded to attend the meeting by her employer, the NRC.« less

SU-A-210-03: Panel Discussion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodrigues, A.

The purpose of this student annual meeting is to address topics that are becoming more relevant to medical physicists, but are not frequently addressed, especially for students and trainees just entering the field. The talk is divided into two parts: medical billing and regulations. Hsinshun Wu – Why should we learn radiation oncology billing? Many medical physicists do not like to be involved with medical billing or coding during their career. They believe billing is not their responsibility and sometimes they even refuse to participate in the billing process if given the chance. This presentation will talk about a physicist’smore » long career and share his own experience that knowing medical billing is not only important and necessary for every young medical physicist, but that good billing knowledge could provide a valuable contribution to his/her medical physics development. Learning Objectives: The audience will learn the basic definition of Current Procedural Terminology (CPT) codes performed in a Radiation Oncology Department. Understand the differences between hospital coding and physician-based or freestanding coding. Apply proper CPT coding for each Radiation Oncology procedure. Each procedure with its specific CPT code will be discussed in detail. The talk will focus on the process of care and use of actual workflow to understand each CPT code. Example coding of a typical Radiation Oncology procedure. Special procedure coding such as brachytherapy, proton therapy, radiosurgery, and SBRT. Maryann Abogunde – Medical physics opportunities at the Nuclear Regulatory Commission (NRC) The NRC’s responsibilities include the regulation of medical uses of byproduct (radioactive) materials and oversight of medical use end-users (licensees) through a combination of regulatory requirements, licensing, safety oversight including inspection and enforcement, operational experience evaluation, and regulatory support activities. This presentation will explore the career options for medical physicists in the NRC, how the NRC interacts with clinical medical physicists, and a physicist’s experience as a regulator. Learning Objectives: Explore non-clinical career pathways for medical physics students and trainees at the Nuclear Regulatory Commission. Overview of NRC medical applications and medical use regulations. Understand the skills needed for physicists as regulators. Abogunde is funded to attend the meeting by her employer, the NRC.« less

Radiation health research, 1986 - 1990

NASA Technical Reports Server (NTRS)

1991-01-01

A collection of 225 abstracts of radiation research sponsored by NASA during the period 1986 through 1990 is reported. Each abstract was categorized within one of four discipline areas: physics, biology, risk assessment, and microgravity. Topic areas within each discipline were assigned as follows: Physics - atomic physics, nuclear science, space radiation, radiation transport and shielding, and instrumentation; Biology - molecular biology, cellular radiation biology, tissue, organs and organisms, radioprotectants, and plants; Risk assessment - radiation health and epidemiology, space flight radiation health physics, inter- and intraspecies extrapolation, and radiation limits and standards; and Microgravity. When applicable subareas were assigned for selected topic areas. Keywords and author indices are provided.

21 CFR 900.12 - Quality standards.

Code of Federal Regulations, 2014 CFR

2014-04-01

... to mammography. The training shall include instruction in radiation physics, including radiation physics specific to mammography, radiation effects, and radiation protection. The mammographic... ensure that medical physicists certified by the body are competent to perform physics survey; and (B)(1...

21 CFR 900.12 - Quality standards.

Code of Federal Regulations, 2013 CFR

2013-04-01

... to mammography. The training shall include instruction in radiation physics, including radiation physics specific to mammography, radiation effects, and radiation protection. The mammographic... ensure that medical physicists certified by the body are competent to perform physics survey; and (B)(1...

21 CFR 900.12 - Quality standards.

Code of Federal Regulations, 2012 CFR

2012-04-01

... to mammography. The training shall include instruction in radiation physics, including radiation physics specific to mammography, radiation effects, and radiation protection. The mammographic... ensure that medical physicists certified by the body are competent to perform physics survey; and (B)(1...

21 CFR 900.12 - Quality standards.

Code of Federal Regulations, 2011 CFR

2011-04-01

... to mammography. The training shall include instruction in radiation physics, including radiation physics specific to mammography, radiation effects, and radiation protection. The mammographic... ensure that medical physicists certified by the body are competent to perform physics survey; and (B)(1...

Atmospheric Radiation Measurement Madden-Julian Oscillation Investigation Experiment Field Campaign Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Chuck

2016-07-01

Every 30–90 days during the Northern Hemisphere winter, the equatorial tropical atmosphere experiences pulses of extraordinarily strong deep convection and rainfall. This phenomenon is referred to as the Madden–Julian Oscillation, or MJO, named after the scientists who identified this cycle. The MJO significantly affects weather and rainfall patterns around the world (Zhang 2013). To improve predictions of the MJO—especially about how it forms and evolves throughout its lifecycle—an international group of scientists collected an unprecedented set of observations from the Indian Ocean and western Pacific region from October 2011 through March 2012 through several coordinated efforts. The coordinated field campaignsmore » captured six distinct MJO cycles in the Indian Ocean. The rich set of observations capturing several MJO events from these efforts will be used for many years to study the physics of the MJO. Here we highlight early research results using data from the Atmospheric Radiation Measurement (ARM) Madden-Julian Oscillation Investigation Experiment (AMIE), sponsored by the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility.« less

Parametric dependence of density limits in the Tokamak Experiment for Technology Oriented Research (TEXTOR): Comparison of thermal instability theory with experiment

NASA Astrophysics Data System (ADS)

Kelly, F. A.; Stacey, W. M.; Rapp, J.

2001-11-01

The observed dependence of the TEXTOR [Tokamak Experiment for Technology Oriented Research: E. Hintz, P. Bogen, H. A. Claassen et al., Contributions to High Temperature Plasma Physics, edited by K. H. Spatschek and J. Uhlenbusch (Akademie Verlag, Berlin, 1994), p. 373] density limit on global parameters (I, B, P, etc.) and wall conditioning is compared with the predicted density limit parametric scaling of thermal instability theory. It is necessary first to relate the edge parameters of the thermal instability theory to n¯ and the other global parameters. The observed parametric dependence of the density limit in TEXTOR is generally consistent with the predicted density limit scaling of thermal instability theory. The observed wall conditioning dependence of the density limit can be reconciled with the theory in terms of the radiative emissivity temperature dependence of different impurities in the plasma edge. The thermal instability theory also provides an explanation of why symmetric detachment precedes radiative collapse for most low power shots, while a multifaceted asymmetric radiation from the edge MARFE precedes detachment for most high power shots.

Gas Filled RF Resonator Hadron Beam Monitor for Intense Neutrino Beam Experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yonehara, Katsuya; Abrams, Robert; Dinkel, Holly

MW-class beam facilities are being considered all over the world to produce an intense neutrino beam for fundamental particle physics experiments. A radiation-robust beam monitor system is required to diagnose the primary and secondary beam qualities in high-radiation environments. We have proposed a novel gas-filled RF-resonator hadron beam monitor in which charged particles passing through the resonator produce ionized plasma that changes the permittivity of the gas. The sensitivity of the monitor has been evaluated in numerical simulation. A signal manipulation algorithm has been designed. A prototype system will be constructed and tested by using a proton beam at themore » MuCool Test Area at Fermilab.« less

Kak Amerikantsy iskali vetra v pole, a nashli radiatsionnyj poyas i kak Russkie iskali radiatsionnyj poyas, a nashli solnechnyj veter Chast' I %t How Americans looked for "a wind in a field" but found a radiation belt, and how Russians looked for a radiation belt but found a solar wind or physical experiments on the first artificial Earth's satellites and a discovery of radiation belts

NASA Astrophysics Data System (ADS)

Zavidonov, I. V.

The history of the most important scientific discovery of the early space era - the discovery of the inner and outer radiation belts of the Earth in 1958 is reconstructed. The paper uses archival records to bring to light the relative contributions of Soviet and American reseachers to the complex process of discovery. It also shows how misuses of science in mass-media political propaganda led to misrepresentations of the real historical portrayal of early space research.

Surface physics-materials science research possibilities on a lunar base

NASA Astrophysics Data System (ADS)

Ignatiev, A.

1990-03-01

The benefits of experimental investigations are discussed in terms of the vacuum environment and low-gravity conditions which can be made possible by a lunar base. The proposed experiments address the interaction of UV and cosmic radiation with the atomic surfaces and bulk properties of materials, the study of microclusters, and the development of epitaxial films in a lunar environment. The interaction of low- and high-energy charged particles and radiation with materials can potentially be studied to analyze the use of the materials in space.

Check the Lambert-Beer-Bouguer law: a simple trick to boost the confidence of students toward both exponential laws and the discrete approach to experimental physics

NASA Astrophysics Data System (ADS)

Di Capua, R.; Offi, F.; Fontana, F.

2014-07-01

Exponential decay is a prototypical functional behaviour for many physical phenomena, and therefore it deserves great attention in physics courses at an academic level. The absorption of the electromagnetic radiation that propagates in a dissipative medium provides an example of the decay of light intensity, as stated by the law of Lambert-Beer-Bourguer. We devised a very simple experiment to check this law. The experimental setup, its realization, and the data analysis of the experiment are definitely simple. Our main goal was to create an experiment that is accessible to all students, including those in their first year of academic courses and those with poorly equipped laboratories. As illustrated in this paper, our proposal allowed us to develop a deep discussion about some general mathematical and numerical features of exponential decay. Furthermore, the special setup of the absorbing medium (sliced in finite thickness slabs) and the experimental outcomes allow students to understand the transition from the discrete to the continuum approach in experimental physics.

An AMR capable finite element diffusion solver for ALE hydrocodes [An AMR capable diffusion solver for ALE-AMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fisher, A. C.; Bailey, D. S.; Kaiser, T. B.

2015-02-01

Here, we present a novel method for the solution of the diffusion equation on a composite AMR mesh. This approach is suitable for including diffusion based physics modules to hydrocodes that support ALE and AMR capabilities. To illustrate, we proffer our implementations of diffusion based radiation transport and heat conduction in a hydrocode called ALE-AMR. Numerical experiments conducted with the diffusion solver and associated physics packages yield 2nd order convergence in the L 2 norm.

Optimization of the Mu2e Production Solenoid Heat and Radiation Shield

NASA Astrophysics Data System (ADS)

Pronskikh, V. S.; Coleman, R.; Glenzinski, D.; Kashikhin, V. V.; Mokhov, N. V.

2014-03-01

The Mu2e experiment at Fermilab is designed to study the conversion of a negative muon to electron in the field of a nucleus without emission of neutrinos. Observation of this process would provide unambiguous evidence for physics beyond the Standard Model, and can point to new physics beyond the reach of the LHC. The main parts of the Mu2e apparatus are its superconducting solenoids: Production Solenoid (PS), Transport Solenoid (TS), and Detector Solenoid (DS). Being in the vicinity of the beam, PS magnets are most subjected to the radiation damage. In order for the PS superconducting magnet to operate reliably, the peak neutron flux in the PS coils must be reduced by 3 orders of magnitude by means of sophisticatedly designed massive Heat and Radiation Shield (HRS), optimized for the performance and cost. An issue with radiation damage is related to large residual electrical resistivity degradation in the superconducting coils, especially its Al stabilizer. A detailed MARS15 analysis and optimization of the HRS has been carried out both to satisfy the Mu2e requirements to the radiation quantities (such as displacements per atom, peak temperature and power density in the coils, absorbed dose in the insulation, and dynamic heat load) and cost. Results of MARS15 simulations of these radiation quantities are reported and optimized HRS models are presented; it is shown that design levels satisfy all requirements.

Comparing simulations and test data of a radiation damaged charge-coupled device for the Euclid mission

NASA Astrophysics Data System (ADS)

Skottfelt, Jesper; Hall, David J.; Gow, Jason P. D.; Murray, Neil J.; Holland, Andrew D.; Prod'homme, Thibaut

2017-04-01

The visible imager instrument on board the Euclid mission is a weak-lensing experiment that depends on very precise shape measurements of distant galaxies obtained by a large charge-coupled device (CCD) array. Due to the harsh radiative environment outside the Earth's atmosphere, it is anticipated that the CCDs over the mission lifetime will be degraded to an extent that these measurements will be possible only through the correction of radiation damage effects. We have therefore created a Monte Carlo model that simulates the physical processes taking place when transferring signals through a radiation-damaged CCD. The software is based on Shockley-Read-Hall theory and is made to mimic the physical properties in the CCD as closely as possible. The code runs on a single electrode level and takes the three-dimensional trap position, potential structure of the pixel, and multilevel clocking into account. A key element of the model is that it also takes device specific simulations of electron density as a direct input, thereby avoiding making any analytical assumptions about the size and density of the charge cloud. This paper illustrates how test data and simulated data can be compared in order to further our understanding of the positions and properties of the individual radiation-induced traps.

Factors influencing radiation therapy student clinical placement satisfaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bridge, Pete; Carmichael, Mary-Ann

Introduction: Radiation therapy students at Queensland University of Technology (QUT) attend clinical placements at five different clinical departments with varying resources and support strategies. This study aimed to determine the relative availability and perceived importance of different factors affecting student support while on clinical placement. The purpose of the research was to inform development of future support mechanisms to enhance radiation therapy students’ experience on clinical placement. Methods: This study used anonymous Likert-style surveys to gather data from years 1 and 2 radiation therapy students from QUT and clinical educators from Queensland relating to availability and importance of support mechanismsmore » during clinical placements in a semester. Results: The study findings demonstrated student satisfaction with clinical support and suggested that level of support on placement influenced student employment choices. Staff support was perceived as more important than physical resources; particularly access to a named mentor, a clinical educator and weekly formative feedback. Both students and educators highlighted the impact of time pressures. Conclusions: The support offered to radiation therapy students by clinical staff is more highly valued than physical resources or models of placement support. Protected time and acknowledgement of the importance of clinical education roles are both invaluable. Joint investment in mentor support by both universities and clinical departments is crucial for facilitation of effective clinical learning.« less

On The Detection Of Footprints From Strong Electron Acceleration In High-Intensity Laser Fields, Including The Unruh Effect

NASA Astrophysics Data System (ADS)

Thirolf, P. G.; Habs, D.; Homma, K.; Hörlein, R.; Karsch, S.; Krausz, F.; Maia, C.; Osterhoff, J.; Popp, A.; Schmid, K.; Schreiber, J.; Schützhold, R.; Tajima, T.; Veisz, L.; Wulz, J.; Yamazaki, T.

2010-04-01

The ultra-high fields of high-power short-pulse lasers are expected to contribute to understanding fundamental properties of the quantum vacuum and quantum theory in very strong fields. For example, the neutral QED vacuum breaks down at the Schwinger field strength of 1.3 1018V/m, where a virtual e+e- pair gains its rest mass energy over a Compton wavelength and materializes as a real pair. At such an ultra-high field strength, an electron experiences an acceleration of as = 2 1028 g and hence fundamental phenomena such as the long predicted Unruh effect start to play a role. The Unruh effect implies that the accelerated electron experiences the vacuum as a thermal bath with the Unruh temperature. In its accelerated frame the electron scatters photons off the thermal bath, corresponding to the emission of an entangled pair of photons in the laboratory frame. In upcoming experiments with intense accelerating fields, we will encounter a set of opportunities to experimentally study the radiation from electrons under extreme fields. Even before the Unruh radiation detection, we should run into the copious Larmor radiation. The detection of Larmor radiation and its characterization themselves have never been experimentally carried out to the best of our knowledge, and thus this amounts to a first serious study of physics at extreme acceleration. For example, we can study radiation damping effects like the Landau-Lifshitz radiation. Furthermore, the experiment should be able to confirm or disprove whether the Larmor and Landau-Lifshitz radiation components may be enhanced by a collective (N2) radiation, if a tightly clumped cluster of electrons is accelerated. The technique of laser driven dense electron sheet formation by irradiating a thin DLC foil target should provide such a coherent electron cluster with a very high density. If and when such mildly relativistic electron sheets are realized, a counterpropagating second laser can interact with them coherently. Under these conditions enhanced Larmor and Unruh radiation signals may be observed. Detection of the Unruh photons (together with its competing radiation components) is envisaged via Compton polarimetry in a novel highly granular 2D-segmented position-sensitive germanium detector.

A Rat Body Phantom for Radiation Analysis

NASA Technical Reports Server (NTRS)

Qualls, Garry D.; Clowdsley, Martha S.; Slaba, Tony C.; Walker, Steven A.

2010-01-01

To reduce the uncertainties associated with estimating the biological effects of ionizing radiation in tissue, researchers rely on laboratory experiments in which mono-energetic, single specie beams are applied to cell cultures, insects, and small animals. To estimate the radiation effects on astronauts in deep space or low Earth orbit, who are exposed to mixed field broad spectrum radiation, these experimental results are extrapolated and combined with other data to produce radiation quality factors, radiation weighting factors, and other risk related quantities for humans. One way to reduce the uncertainty associated with such extrapolations is to utilize analysis tools that are applicable to both laboratory and space environments. The use of physical and computational body phantoms to predict radiation exposure and its effects is well established and a wide range of human and non-human phantoms are in use today. In this paper, a computational rat phantom is presented, as well as a description of the process through which that phantom has been coupled to existing radiation analysis tools. Sample results are presented for two space radiation environments.

Electrodynamic Dust Shield for Lunar/ISS Experiment Project

NASA Technical Reports Server (NTRS)

Zeitlin, Nancy; Calle, Carlos; Hogue, Michael; Johansen, Michael; Mackey, Paul

2015-01-01

The Electrostatics and Surface Physics Laboratory at Kennedy Space Center is developing a dust mitigation experiment and testing it on the lunar surface and on the International Space Station (ISS). The Electrodynamic Dust Shield (EDS) clears dust off surfaces and prevents accumulation by using a pattern of electrodes to generate a non-uniform electric field over the surface being protected. The EDS experiment will repel dust off materials such as painted Kapton and glass to demonstrate applications for thermal radiators, camera lenses, solar panels, and other hardware and equipment.

Fermilab E1039 Radiation Studies to Optimize the Experimental Layout

NASA Astrophysics Data System (ADS)

McNease, Shannon; SeaQuest Collaboration

2017-09-01

Experiment 1039 at Fermi National Accelerator Lab will use the 120 GeV proton beam from the Main Injector to collide with a polarized target to study the spin structure of the nucleon sea quarks. In particular E1039 will measure the asymmetry in the distribution of the muon pairs produced in the Drell-Yan process. In order to polarize the target of frozen NH3 and ND3 a series of vacuum pumps is needed in the high radiation area near the target. This experiment will use the same spectrometer, beam line, and spill structure as E906 along with same shielding with minor upgrades; therefore measurements made by the Fermilab radiation safety team during SeaQuest run can be used for a radiation study. The measurements of thermoluminescent dosimeter badges, and ion chambers are compared with the MARS simulation of the radiation field in SeaQuest to give the amount of radiation in a particular area outside of the shielding. With these three studies a proposal was made for the best placement of the sensitive electronics that is inside the vacuum pump controller, and to see if more protection is needed. This presentation will cover the process of research and calculations of the radiation study and the proposed best place for the controller electronics. Supported by U.S. D.O.E. Medium Energy Nuclear Physics under Grant DE-FG02-03ER41243.

Pulse - Accelerator Science in Medicine

Science.gov Websites

Emilio Segre D iscoveries in physics have helped forge dramatic advances in cancer treatment for over a century. In 1950-54, according to the National Cancer Institute, the five-year survival rate for treated their mother’s cancer with radiation from their new cyclotron in 1931, they were experimenting

Focusing giga-electronvolt heavy ions to micrometers at the Institute of Modern Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheng Lina; Du Guanghua; Guo Jinlong

2013-05-15

To study the radiation effect of cosmic heavy ions of low fluxes in electronics and living samples, a focusing heavy ion microbeam facility, for ions with energies of several MeV/u up to 100 MeV/u, was constructed in the Institute of Modern Physics of the Chinese Academy of Sciences. This facility has a vertical design and an experiment platform for both in-vacuum analysis and in-air irradiation. Recently, microbeam of {sup 12}C{sup 6+} with energy of 80.55 MeV/u was successfully achieved at this interdisciplinary microbeam facility with a full beam spot size of 3 {mu}m Multiplication-Sign 5 {mu}m on target in air.more » Different from ions with energy of several MeV/u, the very high ion energy of hundred MeV/u level induces problems in beam micro-collimation, online beam spot diagnosis, radiation protection, etc. This paper presents the microbeam setup, difficulties in microbeam formation, and the preliminary experiments performed with the facility.« less

Progress towards experimental realization of extreme-velocity flow-dominated magnetized plasmas

NASA Astrophysics Data System (ADS)

Weber, T. E.; Adams, C. S.; Welch, D. R.; Kagan, G.; Bean, I. A.; Henderson, B. R.; Klim, A. J.

2017-10-01

Interactions of flow-dominated plasmas with other plasmas, neutral gases, magnetic fields, solids etc., take place with sufficient velocity that kinetic energy dominates the dynamics of the interaction (as opposed to magnetic or thermal energy, which dominates in most laboratory plasma experiments). Building upon progress made by the Magnetized Shock Experiment (MSX) at LANL, we are developing the experimental and modeling capability to increase our ultimate attainable plasma velocities well in excess of 1000 km/s. Ongoing work includes designing new pulsed power switches, triggering, and inductive adder topologies; development of novel high-speed optical diagnostics; and exploration of new numerical techniques to specifically model the unique physics of translating/stagnating flow-dominated plasmas. Furthering our understanding of the physical mechanisms of energy conversion from kinetic to other forms, such as thermal energy, non-thermal tails/accelerated populations, enhanced magnetic fields, and radiation (both continuum and line), has wide-ranging significance in basic plasma science, astrophysics, and plasma technology applications such as inertial confinement fusion and intense radiation sources. This work is supported by the U.S. Department of Energy, National Nuclear Security Administration. LA-UR-17-25786.

[Interaction between clinical and research towards venture business].

PubMed

Sumida, Iori

2014-01-01

The author as a medical physicist has supported multiple institutions where the advanced radiation therapies as well as the conventional radiation therapy have been performed. Since the advanced radiation treatment techniques have spread rapidly, the quality assurance (QA) has been more important and complex that results in the increase of QA items. In order to maintain the quality of radiation therapy as accurate as possible, the efficient and objective approach for performing QA should be important. Author has developed some QA software which has solved those approaches based on the experiment. In this paper the background in multiple institutions as a view point of radiation treatment situation is presented and what author contributes to those institutions by a medical physics support is shown, finally it is considered that how the developed software has spread in Japan and used for many institutions via venture business.

Effect of atmospheric scattering and surface reflection on upwelling solar radiation

NASA Technical Reports Server (NTRS)

Suttles, J. T.; Barkstrom, B. R.; Tiwari, S. N.

1981-01-01

A study is presented of the solar radiation transfer in the complete earth-atmosphere system, and numerical results are compared with satellite data obtained during the Earth Radiation Budget Experiment on Nimbus 6, in August, 1975. Emphasis is placed on the upwelling radiance distribution at the top of the atmosphere, assumed to be at 50 km. The numerical technique is based on the finite difference method, which includes azimuth and spectral variations for the entire solar wavelength range. Detailed solar properties, atmospheric physical properties, and optical properties are used. However, since the property descriptions are based on a trade-off between accuracy and computational realities, aerosol and cloud optical properties are treated with simple approximations. The radiative transfer model is in good agreement with the satellite radiance observations. The method provides a valuable tool in analyzing satellite- and ground-based radiation budget measurements and in designing instrumentation.

Health effects of radiation and other health problems in the aftermath of nuclear accidents, with an emphasis on Fukushima.

PubMed

Hasegawa, Arifumi; Tanigawa, Koichi; Ohtsuru, Akira; Yabe, Hirooki; Maeda, Masaharu; Shigemura, Jun; Ohira, Tetsuya; Tominaga, Takako; Akashi, Makoto; Hirohashi, Nobuyuki; Ishikawa, Tetsuo; Kamiya, Kenji; Shibuya, Kenji; Yamashita, Shunichi; Chhem, Rethy K

2015-08-01

437 nuclear power plants are in operation at present around the world to meet increasing energy demands. Unfortunately, five major nuclear accidents have occurred in the past--ie, at Kyshtym (Russia [then USSR], 1957), Windscale Piles (UK, 1957), Three Mile Island (USA, 1979), Chernobyl (Ukraine [then USSR], 1986), and Fukushima (Japan, 2011). The effects of these accidents on individuals and societies are diverse and enduring. Accumulated evidence about radiation health effects on atomic bomb survivors and other radiation-exposed people has formed the basis for national and international regulations about radiation protection. However, past experiences suggest that common issues were not necessarily physical health problems directly attributable to radiation exposure, but rather psychological and social effects. Additionally, evacuation and long-term displacement created severe health-care problems for the most vulnerable people, such as hospital inpatients and elderly people. Copyright © 2015 Elsevier Ltd. All rights reserved.

Life sciences.

PubMed

Martin-Brennan, Cindy; Joshi, Jitendra

2003-12-01

Space life sciences research activities are reviewed for 2003. Many life sciences experiments were lost with the tragic loss of STS-107. Life sciences experiments continue to fly as small payloads to the International Space Station (ISS) via the Russian Progress vehicle. Health-related studies continue with the Martian Radiation Environment Experiment (MARIE) aboard the Odyssey spacecraft, collecting data on the radiation environment in Mars orbit. NASA Ames increased nanotechnology research in all areas, including fundamental biology, bioastronautics, life support systems, and homeland security. Plant research efforts continued at NASA Kennedy, testing candidate crops for ISS. Research included plant growth studies at different light intensities, varying carbon dioxide concentrations, and different growth media. Education and outreach efforts included development of a NASA/USDA program called Space Agriculture in the Classroom. Canada sponsored a project called Tomatosphere, with classrooms across North America exposing seeds to simulated Mars environment for growth studies. NASA's Office of Biological and Physical Research released an updated strategic research plan.

Open inquiry-based learning experiences: a case study in the context of energy exchange by thermal radiation

NASA Astrophysics Data System (ADS)

Pizzolato, Nicola; Fazio, Claudio; Rosario Battaglia, Onofrio

2014-01-01

An open inquiry (OI)-based teaching/learning experience, regarding a scientific investigation of the process of energy exchange by thermal radiation, is presented. A sample of upper secondary school physics teachers carried out this experience at the University of Palermo, Italy, in the framework of ESTABLISH, a FP7 European Project aimed at promoting and developing inquiry-based science education. The teachers had the opportunity to personally experience an OI-based learning activity, with the aim of exploring the pedagogical potentialities of this teaching approach to promote both the understanding of difficult concepts and a deeper view of scientific practices. The teachers were firstly engaged in discussions concerning real-life problematic situations, and then stimulated to design and carry out their own laboratory activities, aimed at investigating the process of energy exchange by thermal radiation. A scientific study on the energy exchange between a powered resistor and its surrounding environment, during the heating and cooling processes, was designed and performed. Here we report the phases of this experiment by following the teachers' perspective. A structured interview conducted both before and after the OI experience allowed us to analyze and point out the teachers' feedback from a pedagogical point of view. The advantages and limits of an OI-based approach to promote the development of more student-centred inquiry-oriented teaching strategies are finally discussed.

Characterization of PbWO4 crystals for high-energy physics experiments

NASA Astrophysics Data System (ADS)

Kim, M. J.; Park, H.; Kim, H. J.

2016-09-01

High-energy physics (HEP) experiments have employed many new types of scintillators. Specifically, bismuth germanate, thallium-doped cesium iodide, and lead tungstate (PbWO4, PWO) have been used for the L3 experiment; CLEO II, Belle and BES-III; and CMS, respectively. PWO has particularly beneficial properties, such as high density, fast decay time, short radiation length and radiation hardness. In this study, we tested the PWO crystals at low temperatures to determine their applicability in future calorimeters. Various crystals from the Proton Antiproton Annihilations at Darmstadt (PANDA) experiment in Giessen, the Bogoroditsk Techno-Chemical Plant (BTCP) in Russia and by Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS) in China were investigated. We studied the scintillation properties of PWO crystals, such as their X-ray luminescence, relative light yields, absolute light yields, energy resolutions, decay times and longitudinal uniformities of their light yields. In addition, we measured the temperature dependences of the light yields and decay times by using a 137Cs γ-ray source. The emission spectra of the PWO crystals consisted of a broad band from 350 nm to 700 nm, and the peak emission wavelength in each spectrum was 420 nm. The emission spectra of the PWO crystals from SICCAS were slightly shifted to longer wavelengths compared with those of the crystals from the other institutions.

Radiation Therapy: Professions in Radiation Therapy

MedlinePlus

... and typically one to two years of clinical physics training. They are certified by the American Board of Radiology or the American Board of Medical Physics . Radiation Therapist Radiation therapists work with radiation oncologists. ...

The origin of neutron biological effectiveness as a function of energy.

PubMed

Baiocco, G; Barbieri, S; Babini, G; Morini, J; Alloni, D; Friedland, W; Kundrát, P; Schmitt, E; Puchalska, M; Sihver, L; Ottolenghi, A

2016-09-22

The understanding of the impact of radiation quality in early and late responses of biological targets to ionizing radiation exposure necessarily grounds on the results of mechanistic studies starting from physical interactions. This is particularly true when, already at the physical stage, the radiation field is mixed, as it is the case for neutron exposure. Neutron Relative Biological Effectiveness (RBE) is energy dependent, maximal for energies ~1 MeV, varying significantly among different experiments. The aim of this work is to shed light on neutron biological effectiveness as a function of field characteristics, with a comprehensive modeling approach: this brings together transport calculations of neutrons through matter (with the code PHITS) and the predictive power of the biophysical track structure code PARTRAC in terms of DNA damage evaluation. Two different energy dependent neutron RBE models are proposed: the first is phenomenological and based only on the characterization of linear energy transfer on a microscopic scale; the second is purely ab-initio and based on the induction of complex DNA damage. Results for the two models are compared and found in good qualitative agreement with current standards for radiation protection factors, which are agreed upon on the basis of RBE data.

The origin of neutron biological effectiveness as a function of energy

NASA Astrophysics Data System (ADS)

Baiocco, G.; Barbieri, S.; Babini, G.; Morini, J.; Alloni, D.; Friedland, W.; Kundrát, P.; Schmitt, E.; Puchalska, M.; Sihver, L.; Ottolenghi, A.

2016-09-01

The understanding of the impact of radiation quality in early and late responses of biological targets to ionizing radiation exposure necessarily grounds on the results of mechanistic studies starting from physical interactions. This is particularly true when, already at the physical stage, the radiation field is mixed, as it is the case for neutron exposure. Neutron Relative Biological Effectiveness (RBE) is energy dependent, maximal for energies ~1 MeV, varying significantly among different experiments. The aim of this work is to shed light on neutron biological effectiveness as a function of field characteristics, with a comprehensive modeling approach: this brings together transport calculations of neutrons through matter (with the code PHITS) and the predictive power of the biophysical track structure code PARTRAC in terms of DNA damage evaluation. Two different energy dependent neutron RBE models are proposed: the first is phenomenological and based only on the characterization of linear energy transfer on a microscopic scale; the second is purely ab-initio and based on the induction of complex DNA damage. Results for the two models are compared and found in good qualitative agreement with current standards for radiation protection factors, which are agreed upon on the basis of RBE data.

In silico nanodosimetry: new insights into nontargeted biological responses to radiation.

PubMed

Kuncic, Zdenka; Byrne, Hilary L; McNamara, Aimee L; Guatelli, Susanna; Domanova, Westa; Incerti, Sébastien

2012-01-01

The long-held view that radiation-induced biological damage must be initiated in the cell nucleus, either on or near DNA itself, is being confronted by mounting evidence to suggest otherwise. While the efficacy of cell death may be determined by radiation damage to nuclear DNA, a plethora of less deterministic biological responses has been observed when DNA is not targeted. These so-called nontargeted responses cannot be understood in the framework of DNA-centric radiobiological models; what is needed are new physically motivated models that address the damage-sensing signalling pathways triggered by the production of reactive free radicals. To this end, we have conducted a series of in silico experiments aimed at elucidating the underlying physical processes responsible for nontargeted biological responses to radiation. Our simulation studies implement new results on very low-energy electromagnetic interactions in liquid water (applicable down to nanoscales) and we also consider a realistic simulation of extranuclear microbeam irradiation of a cell. Our results support the idea that organelles with important functional roles, such as mitochondria and lysosomes, as well as membranes, are viable targets for ionizations and excitations, and their chemical composition and density are critical to determining the free radical yield and ensuing biological responses.

The origin of neutron biological effectiveness as a function of energy

PubMed Central

Baiocco, G.; Barbieri, S.; Babini, G.; Morini, J.; Alloni, D.; Friedland, W.; Kundrát, P.; Schmitt, E.; Puchalska, M.; Sihver, L.; Ottolenghi, A.

2016-01-01

The understanding of the impact of radiation quality in early and late responses of biological targets to ionizing radiation exposure necessarily grounds on the results of mechanistic studies starting from physical interactions. This is particularly true when, already at the physical stage, the radiation field is mixed, as it is the case for neutron exposure. Neutron Relative Biological Effectiveness (RBE) is energy dependent, maximal for energies ~1 MeV, varying significantly among different experiments. The aim of this work is to shed light on neutron biological effectiveness as a function of field characteristics, with a comprehensive modeling approach: this brings together transport calculations of neutrons through matter (with the code PHITS) and the predictive power of the biophysical track structure code PARTRAC in terms of DNA damage evaluation. Two different energy dependent neutron RBE models are proposed: the first is phenomenological and based only on the characterization of linear energy transfer on a microscopic scale; the second is purely ab-initio and based on the induction of complex DNA damage. Results for the two models are compared and found in good qualitative agreement with current standards for radiation protection factors, which are agreed upon on the basis of RBE data. PMID:27654349

CERN-derived analysis of lunar radiation backgrounds

NASA Technical Reports Server (NTRS)

Wilson, Thomas L.; Svoboda, Robert

1993-01-01

The Moon produces radiation which background-limits scientific experiments there. Early analyses of these backgrounds have either failed to take into consideration the effect of charm in particle physics (because they pre-dated its discovery), or have used branching ratios which are no longer strictly valid (due to new accelerator data). We are presently investigating an analytical program for deriving muon and neutrino spectra generated by the Moon, converting an existing CERN computer program known as GEANT which does the same for the Earth. In so doing, this will (1) determine an accurate prompt neutrino spectrum produced by the lunar surface; (2) determine the lunar subsurface particle flux; (3) determine the consequence of charm production physics upon the lunar background radiation environment; and (4) provide an analytical tool for the NASA astrophysics community with which to begin an assessment of the Moon as a scientific laboratory versus its particle radiation environment. This will be done on a recurring basis with the latest experimental results of the particle data groups at Earth-based high-energy accelerators, in particular with the latest branching ratios for charmed meson decay. This will be accomplished for the first time as a full 3-dimensional simulation.

Interactive Soil Dust Aerosol Model in the GISS GCM. Part 1; Sensitivity of the Soil Dust Cycle to Radiative Properties of Soil Dust Aerosols

NASA Technical Reports Server (NTRS)

Perlwitz, Jan; Tegen, Ina; Miller, Ron L.

2000-01-01

The sensitivity of the soil dust aerosol cycle to the radiative forcing by soil dust aerosols is studied. Four experiments with the NASA/GISS atmospheric general circulation model, which includes a soil dust aerosol model, are compared, all using a prescribed climatological sea surface temperature as lower boundary condition. In one experiment, dust is included as dynamic tracer only (without interacting with radiation), whereas dust interacts with radiation in the other simulations. Although the single scattering albedo of dust particles is prescribed to be globally uniform in the experiments with radiatively active dust, a different single scattering albedo is used in those experiments to estimate whether regional variations in dust optical properties, corresponding to variations in mineralogical composition among different source regions, are important for the soil dust cycle and the climate state. On a global scale, the radiative forcing by dust generally causes a reduction in the atmospheric dust load corresponding to a decreased dust source flux. That is, there is a negative feedback in the climate system due to the radiative effect of dust. The dust source flux and its changes were analyzed in more detail for the main dust source regions. This analysis shows that the reduction varies both with the season and with the single scattering albedo of the dust particles. By examining the correlation with the surface wind, it was found that the dust emission from the Saharan/Sahelian source region and from the Arabian peninsula, along with the sensitivity of the emission to the single scattering albedo of dust particles, are related to large scale circulation patterns, in particular to the trade winds during Northern Hemisphere winter and to the Indian monsoon circulation during summer. In the other regions, such relations to the large scale circulation were not found. There, the dependence of dust deflation to radiative forcing by dust particles is probably dominated by physical processes with short time scales. The experiments show that dust radiative forcing can lead to significant changes both in the soil dust cycle and in the climate state. To estimate dust concentration and radiative forcing by dust more accurately, dust size distributions and dust single scattering albedo in the model should be a function of the source region, because dust concentration and climate response to dust radiative forcing are sensitive to dust radiative parameters.

Prospective Physics Teachers' Awareness of Radiation and Radioactivity

ERIC Educational Resources Information Center

Tasoglu, Aslihan Kartal; Ates, Özlem; Bakaç, Mustafa

2015-01-01

The purpose of this study is to investigate prospective physics teachers' knowledge of and attitude towards radiation and radioactivity. Participants of this study are 56 prospective physics teachers. A questionnaire related with the knowledge about radiation and radiation fear was conducted. The results of this study showed that most of the…

Sirepo: a web-based interface for physical optics simulations - its deployment and use at NSLS-II

NASA Astrophysics Data System (ADS)

Rakitin, Maksim S.; Chubar, Oleg; Moeller, Paul; Nagler, Robert; Bruhwiler, David L.

2017-08-01

"Sirepo" is an open source cloud-based software framework which provides a convenient and user-friendly web-interface for scientific codes such as Synchrotron Radiation Workshop (SRW) running on a local machine or a remote server side. SRW is a physical optics code allowing to simulate the synchrotron radiation from various insertion devices (undulators and wigglers) and bending magnets. Another feature of SRW is a support of high-accuracy simulation of fully- and partially-coherent radiation propagation through X-ray optical beamlines, facilitated by so-called "Virtual Beamline" module. In the present work, we will discuss the most important features of Sirepo/SRW interface with emphasis on their use for commissioning of beamlines and simulation of experiments at National Synchrotron Light Source II. In particular, "Flux through Finite Aperture" and "Intensity" reports, visualizing results of the corresponding SRW calculations, are being routinely used for commissioning of undulators and X-ray optical elements. Material properties of crystals, compound refractive lenses, and some other optical elements can be dynamically obtained for the desired photon energy from the databases publicly available at Argonne National Lab and at Lawrence Berkeley Lab. In collaboration with the Center for Functional Nanomaterials (CFN) of BNL, a library of samples for coherent scattering experiments has been implemented in SRW and the corresponding Sample optical element was added to Sirepo. Electron microscope images of artificially created nanoscale samples can be uploaded to Sirepo to simulate scattering patterns created by synchrotron radiation in different experimental schemes that can be realized at beamlines.

Development of radiation tolerant monolithic active pixel sensors with fast column parallel read-out

NASA Astrophysics Data System (ADS)

Koziel, M.; Dorokhov, A.; Fontaine, J.-C.; De Masi, R.; Winter, M.

2010-12-01

Monolithic active pixel sensors (MAPS) [1] (Turchetta et al., 2001) are being developed at IPHC—Strasbourg to equip the EUDET telescope [2] (Haas, 2006) and vertex detectors for future high energy physics experiments, including the STAR upgrade at RHIC [3] (T.S. Collaboration, 2005) and the CBM experiment at FAIR/GSI [4] (Heuser, 2006). High granularity, low material budget and high read-out speed are systematically required for most applications, complemented, for some of them, with high radiation tolerance. A specific column-parallel architecture, implemented in the MIMOSA-22 sensor, was developed to achieve fast read-out MAPS. Previous studies of the front-end architecture integrated in this sensor, which includes in-pixel amplification, have shown that the fixed pattern noise increase consecutive to ionizing radiation can be controlled by means of a negative feedback [5] (Hu-Guo et al., 2008). However, an unexpected rise of the temporal noise was observed. A second version of this chip (MIMOSA-22bis) was produced in order to search for possible improvements of the radiation tolerance, regarding this type of noise. In this prototype, the feedback transistor was tuned in order to mitigate the sensitivity of the pixel to ionizing radiation. The performances of the pixels after irradiation were investigated for two types of feedback transistors: enclosed layout transistor (ELT) [6] (Snoeys et al., 2000) and "standard" transistor with either large or small transconductance. The noise performance of all test structures was studied in various conditions (expected in future experiments) regarding temperature, integration time and ionizing radiation dose. Test results are presented in this paper. Based on these observations, ideas for further improvement of the radiation tolerance of column parallel MAPS are derived.

Critical experiments at Sandia National Laboratories : technical meeting on low-power critical facilities and small reactors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harms, Gary A.; Ford, John T.; Barber, Allison Delo

2010-11-01

Sandia National Laboratories (SNL) has conducted radiation effects testing for the Department of Energy (DOE) and other contractors supporting the DOE since the 1960's. Over this period, the research reactor facilities at Sandia have had a primary mission to provide appropriate nuclear radiation environments for radiation testing and qualification of electronic components and other devices. The current generation of reactors includes the Annular Core Research Reactor (ACRR), a water-moderated pool-type reactor, fueled by elements constructed from UO2-BeO ceramic fuel pellets, and the Sandia Pulse Reactor III (SPR-III), a bare metal fast burst reactor utilizing a uranium-molybdenum alloy fuel. The SPR-IIImore » is currently defueled. The SPR Facility (SPRF) has hosted a series of critical experiments. A purpose-built critical experiment was first operated at the SPRF in the late 1980's. This experiment, called the Space Nuclear Thermal Propulsion Critical Experiment (CX), was designed to explore the reactor physics of a nuclear thermal rocket motor. This experiment was fueled with highly-enriched uranium carbide fuel in annular water-moderated fuel elements. The experiment program was completed and the fuel for the experiment was moved off-site. A second critical experiment, the Burnup Credit Critical Experiment (BUCCX) was operated at Sandia in 2002. The critical assembly for this experiment was based on the assembly used in the CX modified to accommodate low-enriched pin-type fuel in water moderator. This experiment was designed as a platform in which the reactivity effects of specific fission product poisons could be measured. Experiments were carried out on rhodium, an important fission product poison. The fuel and assembly hardware for the BUCCX remains at Sandia and is available for future experimentation. The critical experiment currently in operation at the SPRF is the Seven Percent Critical Experiment (7uPCX). This experiment is designed to provide benchmark reactor physics data to support validation of the reactor physics codes used to design commercial reactor fuel elements in an enrichment range above the current 5% enrichment cap. A first set of critical experiments in the 7uPCX has been completed. More experiments are planned in the 7uPCX series. The critical experiments at Sandia National Laboratories are currently funded by the US Department of Energy Nuclear Criticality Safety Program (NCSP). The NCSP has committed to maintain the critical experiment capability at Sandia and to support the development of a critical experiments training course at the facility. The training course is intended to provide hands-on experiment experience for the training of new and re-training of practicing Nuclear Criticality Safety Engineers. The current plans are for the development of the course to continue through the first part of fiscal year 2011 with the development culminating is the delivery of a prototype of the course in the latter part of the fiscal year. The course will be available in fiscal year 2012.« less

Researche of the Earth's crust structure with powerful vibrational controlled sources

NASA Astrophysics Data System (ADS)

Alekseev, A.; Glinsky, B.; Kovalevsky, V.

2003-04-01

The paper presents the results of experimental researches of the Earth's structure, geodynamic processes and physical phenomena carried out using vibrational sources in Institutes of Siberian Branch RAS. Powerful seismic vibrators are the large mechanical devises and are installed stationary on the vibroseismic test site near Novosibirsk (Russia). The vibro-DSS experiments were carried out on 100 km-long profile from Novosibirsk to Kuzbass region and on 620 km profile between Novosibirsk and Semipalatinsk test site. Specially developed field recording systems based on multichannel three component seismic arrays were used. It allowed us to observe the main crustal waves and waves refracted on Moho boundary. In the experiments on the 620 km profile the comparison of the seismic vibrator and special 100 tons calibration explosion wave fields was made. The possibility to detect small changes of wave velocities by vibroseismic methods were shown in the experiments on the setoff 356 and 430 km, where the relative variations of velocities of seismic waves about 10-5 - 10-6 caused by the Earth's tides deformations of the crust were defined. Some new physical phenomena connected with resonance mechanism of radiation of seismic energy in low-frequency range, the radiation of acoustic waves simultaneously with seismic waves and their interaction on long distances from vibrators were detected.

Laboratory Investigation of Astrophysical Collimated Jets with Intense Lasers

NASA Astrophysics Data System (ADS)

Yuan, Dawei; Li, Yutong; Tao, Tao; Wei, Huigang; Zhong, Jiayong; Zhu, Baojun; Li, Yanfei; Zhao, Jiarui; Li, Fang; Han, Bo; Zhang, Zhe; Liang, Guiyun; Wang, Feilu; Hu, Guangyue; Zheng, Jian; Jiang, Shaoen; Du, Kai; Ding, Yongkun; Zhou, Shenlei; Zhu, Baoqiang; Zhu, Jianqiang; Zhao, Gang; Zhang, Jie

2018-06-01

One of the remarkable dynamic features of the Herbig–Haro (HH) object is its highly collimated propagation far away from the accretion disk. Different factors are proposed to give us a clearly physical explanation behind these fascinating phenomena, including magnetic field, radiation cooling, surrounding medium, and so on. Laboratory astrophysics, as a new complementary method of studying astrophysical issues, can provide an insight into these behaviors in a similar and controllable laboratory environment. Here we report the scaled laboratory experiments that a well-collimated radiative jet with high Mach number is successfully created to mimic the evolution of HH objects. According to our results, we find that the radiation cooling effect within the jet and the outer rare surrounding plasmas from the X-ray (>keV) photoionized target contribute to the jet collimation. The local nonuniform density structures along the collimated radiative jet axis are caused by the pressure competition between the inner jet and the outer plasmas. The corresponding simulations performed with radiation-hydrodynamic codes FLASH reveal how the radiative jet evolves.

Spinning projectile's attitude measurement with LW infrared radiation under sea-sky background

NASA Astrophysics Data System (ADS)

Xu, Miaomiao; Bu, Xiongzhu; Yu, Jing; He, Zilu

2018-05-01

With the further development of infrared radiation research in sea-sky background and the requirement of spinning projectile's attitude measurement, the sea-sky infrared radiation field is used to carry out spinning projectile's attitude angle instead of inertial sensors. Firstly, the generation mechanism of sea-sky infrared radiation is analysed. The mathematical model of sea-sky infrared radiation is deduced in LW (long wave) infrared 8 ∼ 14 μm band by calculating the sea surface and sky infrared radiation. Secondly, according to the movement characteristics of spinning projectile, the attitude measurement model of infrared sensors on projectile's three axis is established. And the feasibility of the model is analysed by simulation. Finally, the projectile's attitude calculation algorithm is designed to improve the attitude angle estimation accuracy. The results of semi-physical experiments show that the segmented interactive algorithm estimation error of pitch and roll angle is within ±1.5°. The attitude measurement method is effective and feasible, and provides accurate measurement basis for the guidance of spinning projectile.

Effects of exposure to ultraviolet light on the development of Rana pipiens, the northern leopard frog

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, J.J.; Wofford, H.W.

1996-10-01

The increase in ultraviolet light intensity levels due to ozone depletion recently has been linked to the decline in amphibian population. In this experiment, eggs and larvae of Rana pipiens were subjected to differing amounts of ultraviolet radiation to determine the effects of ultraviolet light on the development of amphibian tadpoles. The total length, length of body without tail, and maximum width of each specimen was recorded for a month of the tadpoles` development, including several measurements after the ultraviolet exposures were concluded. It was found that ultraviolet exposure significantly reduced the size of the organisms in comparison with themore » control group in all three measured areas. Ultraviolet radiation altered the health and appearance of the exposed organisms and was lethal at large amounts. This experiment showed that ultraviolet radiation could cause many problems in developing amphibians. By slowing their development and physically weakening predation, thus contributing to a decline in overall population levels.« less

Photon Tagger Timing Calibration for the Rad Phi Experiment

NASA Astrophysics Data System (ADS)

Russell, Mammei; Smith, Elton

2000-10-01

Vector mesons provide a rich laboratory for the study of fundamental physics and radiative decays probe the very nature of the internal structure of these mesons, which possess the same quantum numbers of photons. Experiment E94-016, which collected data this past summer in Hall B of the Thomas Jefferson National Accelerator Facility (JLab), has measured the the branching ratios for rare radiative decays of the phi meson, i.e. φarrow f_0(975)γ arrow π^0π^0γ, φ arrow a_0(980)γ arrow π0 η γ, and φ arrow η'γ. A lead glass calorimeter, in concert with several detectors, measured these decays. A tagged beam of bremsstrahlung photons was directed upon a solid Beryllium target. A three-level trigger was then employed to preferentially select radiative decays of the φ meson. We calibrated timing of each detector by referencing individual detectors to one another. Tight timing will enhance signal relative to background.

Basic and Applied Materials Science Research Efforts at MSFC Germane to NASA Goals

NASA Technical Reports Server (NTRS)

2003-01-01

Presently, a number of investigations are ongoing that blend basic research with engineering applications in support of NASA goals. These include (1) "Pore Formation and Mobility (PFMI) " An ISS Glovebox Investigation" NASA Selected Project - 400-34-3D; (2) "Interactions Between Rotating Bodies" Center Director's Discretionary Fund (CDDF) Project - 279-62-00-16; (3) "Molybdenum - Rhenium (Mo-Re) Alloys for Nuclear Fuel Containment" TD Collaboration - 800-11-02; (4) "Fabrication of Alumina - Metal Composites for Propulsion Components" ED Collaboration - 090-50-10; (5) "Radiation Shielding for Deep-Space Missions" SD Effort; (6) "Other Research". In brief, "Pore Formation and Mobility" is an experiment to be conducted in the ISS Microgravity Science Glovebox that will systematically investigate the development, movement, and interactions of bubbles (porosity) during the controlled directional solidification of a transparent material. In addition to promoting our general knowledge of porosity physics, this work will serve as a guide to future ISS experiments utilizing metal alloys. "Interactions Between Rotating Bodies" is a CDDF sponsored project that is critically examining, through theory and experiment, claims of "new" physics relating to gravity modification and electric field effects. "Molybdenum - Rhenium Alloys for Nuclear Fuel Containment" is a TD collaboration in support of nuclear propulsion. Mo-Re alloys are being evaluated and developed for nuclear fuel containment. "Fabrication of Alumina - Metal Composites for Propulsion Components" is an ED collaboration with the intent of increasing strength and decreasing weight of metal engine components through the incorporation of nanometer-sized alumina fibers. "Radiation Shielding for Deep-Space Missions" is an SD effort aimed at minimizing the health risk from radiation to human space voyagers; work to date has been primarily programmatic but experiments to develop hydrogen-rich materials for shielding are planned. "Other Research" includes: BUNDLE (Bridgman Unidirectional Dendrite in a Liquid Experiment) activities (primarily crucible development), vibrational float-zone processing (with Vanderbilt University), use of ultrasonics in materials processing (with UAH), rotational effects on microstructural development, and application of magnetic fields for mixing.

Experiments on aerosol-induced cooling in the nocturnal boundary layer

NASA Astrophysics Data System (ADS)

Sreenivas, K.; Singh, D. K.; Vk, P.; Mukund, V.; Subramanian, G.

2012-12-01

In the nocturnal boundary layer (NBL), under calm & clear-sky conditions, radiation is the principal mode of heat transfer & it determines the temperature distribution close to the ground. Radiative processes thus influence the surface energy budget, & play a decisive role in many micro-meteorological processes including the formation of radiation-fog & inversion layer. Here, we report hyper-cooling of air layers close to the ground that has a radiative origin. Resulting vertical temperature distribution has an anomalous profile with an elevated minimum few decimetres above the ground (known as Lifted Temperature Minimum; LTM). Even though the first observation of this type of profile dates back to 1930s, its origin has not been explained till recently. We report field experiments to elucidate effects of emissivity and other physical properties of the ground on the LTM profile. Field observations clearly indicate that LTM-profiles are observed as a rule in the lowest meter of the NBL. We also demonstrate that the air-layer near the ground, rather than the ground itself, leads the post sunset cooling. This fact changes the very nature of the sensible heat-flux boundary condition. A laboratory experimental setup has been developed that can reproduce LTM. Lab-experiments demonstrate that the high cooling rates observed in the field experiments arise from the presence of aerosols & the intensity of cooling is proportional to aerosol concentration (Fig-1). We have also captured penetrative convection cells in the field experiments (Fig-2). Results presented here thus help in parameterizing transport processes in the NBL.

Hands-on Physics Education of Residents in Diagnostic Radiology.

PubMed

Zhang, Jie; Hardy, Peter A; DiSantis, David J; Oates, M Elizabeth

2017-06-01

The American Board of Radiology Core Examination integrates assessment of physics knowledge into its overall testing of clinical radiology, with an emphasis on understanding image quality and artifacts, radiation dose, and patient safety for each modality or subspecialty organ system. Accordingly, achieving a holistic approach to physics education of radiology residents is a huge challenge. The traditional teaching of radiological physics-simply through didactic lectures-was not designed for such a holistic approach. Admittedly, time constraints and clinical demands can make incorporation of physics teaching into clinical practice problematic. We created and implemented a week-long, intensive physics rotation for fledgling radiology residents and evaluated its effectiveness. The dedicated physics rotation is held for 1 week during the first month of radiology residency. It comprises three components: introductory lectures, hands-on practical clinical physics operations, and observation of clinical image production. A brief introduction of the physics pertinent to each modality is given at the beginning of each session. Hands-on experimental demonstrations are emphasized, receiving the greatest allotment of time. The residents perform experiments such as measuring radiation dose, studying the relationship between patient dose and clinical practice (eg, fluoroscopy technique), investigating the influence of acquisition parameters (kV, mAs) on radiographs, and evaluating image quality using computed tomography, magnetic resonance imaging, ultrasound, and gamma camera/single-photon emission computed tomography/positron emission tomography phantoms. Quantitative assessment of the effectiveness of the rotation is based on an examination that tests the residents' grasp of basic medical physics concepts along with written course evaluations provided by each resident. The pre- and post-rotation tests show that after the physics rotation, the average correct score of 25 questions improved from 13.6 ± 2.4 to 19 ± 1.2. The survey shows that the physics rotation during the first week of residency is favored by all residents and that 1 week's duration is appropriate. All residents are of the opinion that the intensive workshop would benefit them in upcoming clinical rotations. Residents acknowledge becoming more comfortable regarding the use of radiation and providing counsel regarding radiation during pregnancy. An immersive, short-duration, clinically oriented physics rotation is well received by new or less experienced radiology trainees, correlates basic physics concepts with their relevance to clinical imaging, and more closely parallels expectations of the American Board of Radiology Core Examination. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Remote Sensor Application Studies Progress Report, July L, 1968 to June 30, 1969. Controlled Field Experiments

USGS Publications Warehouse

Rowan, L.C.; Offield, T.W.; Watson, R.D.; Cannon, P.J.; Grolier, H.J.; Pohn, H.A.; Watson, Kenneth

1970-01-01

Field Sites have been selected for controlled experiments to analyze physical and chemical parameters affecting the response of electromagnetic radiation to geological materials. Considerations in the selection of the sites are the availability of good exposures of nearly monomineralic rocks, level of geologic understanding, and ease of access. Seven sites, where work is underway or planned, contain extensive outcrops of the following rocks: stanstone, limestone, dolomite, and gypsum. Field measurement of quartz have been conducted at four sites.

Department of Defense Report on Search for Human Radiation Experiment Records, 1944 - 1994, Volume 1

DTIC Science & Technology

1997-06-01

CID93-027 1993 60MG035 1993 CID92-221 1993 CID92-272 Regional cerebral blood flow and glucose rate in patients with complex partial seizures ...34 illnesses or injuries in the body whose diagnosis previously required exploratory surgery or educated guesses. In industrial uses, x-ray machines...all unnecessary physical and mental suffering and injury . f. -No experiment should be conducted where there is an a priori reason to believe that

Entangled γ-photons—classical laboratory exercise with modern detectors

NASA Astrophysics Data System (ADS)

Hetfleiš, Jakub; Lněnička, Jindřich; Šlégr, Jan

2018-03-01

This paper describes the application of modern semiconductor detectors of γ and β radiation, which can be used in undergraduate laboratory experiments and lecture demonstrations as a replacement for Geiger-Müller (GM) tubes. Unlike GM tubes, semiconductor detectors do not require a high voltage power source or shaping circuits. The principle of operation of semiconductor detectors is discussed briefly, and classical experiments from nuclear physics are described, ranging from the measurements of linear and mass attenuation coefficient to a demonstration of entangled γ-photons.

ISCCP CX observations during the FIRE/SRB Wisconsin Experiment from October 14 through November 2, 1986

NASA Technical Reports Server (NTRS)

Whitlock, Charles H.; Lecroy, Stuart R.; Rossow, William B.; Bell, Ken L.

1989-01-01

Maps and tables are presented which show 45 satellite derived physical, radiation, or cloud parameters from ISCCP CX tapes during the FIRE/SRB Wisconsin experiment region from October 14 through November 2, 1986. Pixel locations selected for presentation are for an area which coincided with a 100 x 100 km array of evenly spaced ground truth sites. Area-averaged parameters derived from the ISSCP data should be consistent with area averages from the groundtruth stations.

Final Report: High Energy Physics at the Energy Frontier at Louisiana Tech

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sawyer, Lee; Wobisch, Markus; Greenwood, Zeno D.

The Louisiana Tech University High Energy Physics group has developed a research program aimed at experimentally testing the Standard Model of particle physics and searching for new phenomena through a focused set of analyses in collaboration with the ATLAS experiment at the Large Hadron Collider (LHC) at the CERN laboratory in Geneva. This research program includes involvement in the current operation and maintenance of the ATLAS experiment and full involvement in Phase 1 and Phase 2 upgrades in preparation for future high luminosity (HL-LHC) operation of the LHC. Our focus is solely on the ATLAS experiment at the LHC, withmore » some related detector development and software efforts. We have established important service roles on ATLAS in five major areas: Triggers, especially jet triggers; Data Quality monitoring; grid computing; GPU applications for upgrades; and radiation testing for upgrades. Our physics research is focused on multijet measurements and top quark physics in final states containing tau leptons, which we propose to extend into related searches for new phenomena. Focusing on closely related topics in the jet and top analyses and coordinating these analyses in our group has led to high efficiency and increased visibility inside the ATLAS collaboration and beyond. Based on our work in the DØ experiment in Run II of the Fermilab Tevatron Collider, Louisiana Tech has developed a reputation as one of the leading institutions pursuing jet physics studies. Currently we are applying this expertise to the ATLAS experiment, with several multijet analyses in progress.« less

Calculation and Measurement of Low-Energy Radiative Moller Scattering

NASA Astrophysics Data System (ADS)

Epstein, Charles; DarkLight Collaboration

2017-09-01

A number of current nuclear physics experiments have come to rely on precise knowledge of electron-electron (Moller) and positron-electron (Bhabha) scattering. Some of these experiments, having lepton beams on targets containing atomic electrons, use these purely-QED processes as normalization. In other scenarios, with electron beams at low energy and very high intensity, Moller scattering and radiative Moller scattering have such enormous cross-sections that the backgrounds they produce must be understood. In this low-energy regime, the electron mass is also not negligible in the calculation of the cross section. This is important, for example, in the DarkLight experiment (100 MeV). As a result, we have developed a new event generator for the radiative Moller and Bhabha processes, with new calculations that keep all terms of the electron mass. The MIT High Voltage Research Laboratory provides us a unique opportunity to study this process experimentally and compare it with our work, at a low beam energy of 2.5 MeV where the effects of the electron mass are significant. We are preparing a dedicated apparatus consisting of a magnetic spectrometer in order to directly measure this process. An overview of the calculation and the status of the experiment will be presented.

A crops and soils data base for scene radiation research

NASA Technical Reports Server (NTRS)

Biehl, L. L.; Bauer, M. E.; Robinson, B. F.; Daughtry, C. S. T.; Silva, L. F.; Pitts, D. E.

1982-01-01

Management and planning activities with respect to food production require accurate and timely information on crops and soils on a global basis. The needed information can be obtained with the aid of satellite-borne sensors, if the relations between the spectral properties and the important biological-physical parameters of crops and soils are known. In order to obtain this knowledge, the development of a crops and soils scene radiation research data base was initiated. Work related to the development of this data base is discussed, taking into account details regarding the conducted experiments, the performed measurements, the calibration of spectral data, questions of data base access, and the expansion of the crops and soils scene radiation data base for 1982.

The DOSIS and DOSIS 3D Experiments onboard the International Space Station - Results from the Active DOSTEL Instruments

NASA Astrophysics Data System (ADS)

Burmeister, Soenke; Berger, Thomas; Reitz, Guenther; Beaujean, Rudolf; Boehme, Matthias; Haumann, Lutz; Labrenz, Johannes; Kortmann, Onno

2012-07-01

Besides the effects of the microgravity environment, and the psychological and psychosocial problems experienced in confined spaces, radiation is the main health detriment for long duration human space missions. The radiation environment encountered in space differs in nature from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones present on earth for occupational radiation workers. Accurate knowledge of the physical characteristics of the space radiation field in dependence on the solar activity, the orbital parameters and the different shielding configurations of the International Space Station ISS is therefore needed. For the investigation of the spatial and temporal distribution of the radiation field inside the European COLUMBUS module the experiment DOSIS (Dose Distribution Inside the ISS) under the lead of DLR was launched on July 15th 2009 with STS-127 to the ISS. The experimental package was transferred from the Space Shuttle into COLUMBUS on July 18th. It consists of a combination of passive detector packages (PDP) distributed at 11 locations inside the European Columbus Laboratory and two active radiation detectors (DOSTELs) with a DDPU (DOSTEL Data and Power Unit) in a nomex pouch (DOSIS MAIN BOX) mounted at a fixed location beneath the European Physiology Module rack (EPM) inside COLUMBUS. The DOSTELs measured during the lowest solar minimum conditions in the space age from July 18th 2009 to June 16th 2011. In July 2011 the active hardware was transferred to ground for refurbishment and preparation for the DOSIS-3D experiment. The hardware will be launched with the Soyuz 30S flight to the ISS on May 15th 2012 and activated approximately ten days later. Data will be transferred from the DOSTEL units to ground via the EPM rack which is activated approximately every four weeks for this action. First Results for the active DOSIS-3D measurements such as count rate profiles, dose rates and LET spectra will be presented in comparison to the data of the DOSIS experiment as well as the DOSMAP experiment which has been performed during solar maximum in 2001.

Sensitivity of Regional Climate to Deforestation in the Amazon Basin

NASA Technical Reports Server (NTRS)

Eltahir, Elfatih A. B.; Bras, Rafael L.

1994-01-01

The deforestation results in several adverse effect on the natural environment. The focus of this paper is on the effects of deforestation on land-surface processes and regional climate of the Amazon basin. In general, the effect of deforestation on climate are likely to depend on the scale of the defrosted area. In this study, we are interested in the effects due to deforestation of areas with a scale of about 250 km. Hence, a meso-scale climate model is used in performing numerical experiments on the sensitivity of regional climate to deforestation of areas with that size. It is found that deforestation results in less net surface radiation, less evaporation, less rainfall, and warmer surface temperature. The magnitude of the of the change in temperature is of the order 0.5 C, the magnitudes of the changes in the other variables are of the order of IO%. In order to verify some of he results of the numerical experiments, the model simulations of net surface radiation are compared to recent observations of net radiation over cleared and undisturbed forest in the Amazon. The results of the model and the observations agree in the following conclusion: the difference in net surface radiation between cleared and undisturbed forest is, almost, equally partioned between net solar radiation and net long-wave radiation. This finding contributes to our understanding of the basic physics in the deforestation problem.

Skylab experiments. Volume 1: Physical science, solar astronomy

NASA Technical Reports Server (NTRS)

1973-01-01

The basic subject of this volume is the solar astronomy program conducted on Skylab. In addition to descriptions of the individual experiments and the principles involved in their performance, a brief description is included of the sun and the energy characteristics associated with each zone. Wherever possible, related classroom activities have been identified and discussed in some detail. It will be apparent that the relationships rest not only in the field of solar astronomy, but also in the following subjects: (1) physics - optics, electromagnetic spectrum, atomic structure, etc.; (2) chemistry - emission spectra, kinetic theory, X-ray absorption, etc.; (3) biology - radiation and dependence on the sun; (4) electronics - cathode ray tubes, detectors, photomultipliers, etc.; (5) photography; (6) astronomy; and (7) industrial arts.

Fundamentals of health physics for the radiation-protection officer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, B.L.; Traub, R.J.; Gilchrist, R.L.

1983-03-01

The contents of this book on health physics include chapters on properties of radioactive materials, radiation instrumentation, radiation protection programs, radiation survey programs, internal exposure, external exposure, decontamination, selection and design of radiation facilities, transportation of radioactive materials, radioactive waste management, radiation accidents and emergency preparedness, training, record keeping, quality assurance, and appraisal of radiation protection programs. (ACR)

Human radiation studies: Remembering the early years: Oral history of health physicist Karl Z. Morgan, Ph.D., conducted January 7, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-06-01

This report provided a transcript of an interview of Dr. Karl. Z. Morgan by representatives of the DOE Office of Human Radiation Experiments. Dr. Morgan was selected for this interview because of his research for the Manhattan Project at the Metallurgical Laboratory in Chicago and his work at the Oak Ridge National Laboratory (ORNL). The oral history covers Dr. Morgan`s work as a pioneer in the field of Health Physics, his research at ORNL and his work since he retired from ORNL.

Careers in Medical Physics and the American Association of Physicists in Medicine

NASA Astrophysics Data System (ADS)

Amols, Howard

2006-03-01

The American Association of Physicists in Medicine (AAPM), a member society of the AIP is the largest professional society of medical physicists in the world with nearly 5700 members. Members operate in medical centers, university and community hospitals, research laboratories, industry, and private practice. Medical physics specialties include radiation therapy physics, medical diagnostic and imaging physics, nuclear medicine physics, and medical radiation safety. The majority of AAPM members is based in hospital departments of radiation oncology or radiology and provide technical support for patient diagnosis and treatment in a clinical environment. Job functions include support of clinical care, calibration and quality assurance of medical devices such as linear accelerators for cancer therapy, CT, PET, MRI, and other diagnostic imaging devices, research, and teaching. Pathways into a career in medical physics require an advanced degree in medical physics, physics, engineering, or closely related field, plus clinical training in one or more medical physics specialties (radiation therapy physics, imaging physics, or radiation safety). Most clinically based medical physicists also obtain certification from the American Board of Radiology, and some states require licensure as well.

Long term dose monitoring onboard the European Columbus module of the International Space Station (ISS) in the frame of the DOSIS and DOSIS 3D project

NASA Astrophysics Data System (ADS)

Berger, Thomas

The radiation environment encountered in space differs in nature from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones present on earth for occupational radiation workers. Accurate knowledge of the physical characteristics of the space radiation field in dependence on the solar activity, the orbital parameters and the different shielding configurations of the International Space Station (ISS) is therefore needed. For the investigation of the spatial and temporal distribution of the radiation field inside the European Columbus module the experiment “Dose Distribution Inside the ISS” (DOSIS), under the project and science lead of the German Aerospace Center (DLR), was launched on July 15th 2009 with STS-127 to the ISS. The DOSIS experiment consists of a combination of “Passive Detector Packages” (PDP) distributed at eleven locations inside Columbus for the measurement of the spatial variation of the radiation field and two active Dosimetry Telescopes (DOSTELs) with a Data and Power Unit (DDPU) in a dedicated nomex pouch mounted at a fixed location beneath the European Physiology Module rack (EPM) for the measurement of the temporal variation of the radiation field parameters. The DOSIS experiment suite measured during the lowest solar minimum conditions in the space age from July 2009 to June 2011. In July 2011 the active hardware was transferred to ground for refurbishment and preparation for the follow up DOSIS 3D experiment. The hardware for DOSIS 3D was launched with Soyuz 30S to the ISS on May 15th 2012. The PDPs are replaced with each even number Soyuz flight starting with Soyuz 30S. Data from the active detectors is transferred to ground via the EPM rack which is activated once a month for this action. The presentation will give an overview of the DOSIS and DOSIS 3D experiment and focus on the results from the passive radiation detectors from the DOSIS 3D experiment (2012 - 2014) in comparison to the data of the DOSIS experiment (2009 - 2011). The Polish contribution was supported by the National Science Centre (No DEC-2012/06/M/ST9/00423). The CAU contributions to DOSIS and DOSIS 3D are financially supported by BMWi under Grants 50WB0826, 50WB1026 and 50WB1232.

The MCART radiation physics core: the quest for radiation dosimetry standardization.

PubMed

Kazi, Abdul M; MacVittie, Thomas J; Lasio, Giovanni; Lu, Wei; Prado, Karl L

2014-01-01

Dose-related radiobiological research results can only be compared meaningfully when radiation dosimetry is standardized. To this purpose, the National Institute of Allergy and Infectious Diseases (NIAID)-sponsored Medical Countermeasures Against Radiological Threats (MCART) consortium recently created a Radiation Physics Core (RPC) as an entity to assume responsibility of standardizing radiation dosimetry practices among its member laboratories. The animal research activities in these laboratories use a variety of ionizing photon beams from several irradiators such as 250-320 kVp x-ray generators, Cs irradiators, Co teletherapy machines, and medical linear accelerators (LINACs). In addition to this variety of sources, these centers use a range of irradiation techniques and make use of different dose calculation schemes to conduct their experiments. An extremely important objective in these research activities is to obtain a Dose Response Relationship (DRR) appropriate to their respective organ-specific models of acute and delayed radiation effects. A clear and unambiguous definition of the DRR is essential for the development of medical countermeasures. It is imperative that these DRRs are transparent between centers. The MCART RPC has initiated the establishment of standard dosimetry practices among member centers and is introducing a Remote Dosimetry Monitoring Service (RDMS) to ascertain ongoing quality assurance. This paper will describe the initial activities of the MCART RPC toward implementing these standardization goals. It is appropriate to report a summary of initial activities with the intent of reporting the full implementation at a later date.

Radiation Exposure and Pregnancy

MedlinePlus

Fact Sheet Adopted: June 2010 Updated: June 2017 Health Physics Society Specialists in Radiation Safety Radiation Exposure and ... radiation and pregnancy can be found on the Health Physics Society " Ask the Experts" Web site. she should ...

Radiation Hardness tests with neutron flux on different Silicon photomultiplier devices

NASA Astrophysics Data System (ADS)

Cattaneo, P. W.; Cervi, T.; Menegolli, A.; Oddone, M.; Prata, M.; Prata, M. C.; Rossella, M.

2017-07-01

Radiation hardness is an important requirement for solid state readout devices operating in high radiation environments common in particle physics experiments. The MEG II experiment, at PSI, Switzerland, investigates the forbidden decay μ+ → e+ γ. Exploiting the most intense muon beam of the world. A significant flux of non-thermal neutrons (kinetic energy Ek>= 0.5 MeV) is present in the experimental hall produced along the beam-line and in the hall itself. We present the effects of neutron fluxes comparable to the MEG II expected doses on several Silicon Photomultiplier (SiPMs). The tested models are: AdvanSiD ASD-NUV3S-P50 (used in MEG II experiment), AdvanSiD ASD-NUV3S-P40, AdvanSiD ASD-RGB3S-P40, Hamamatsu and Excelitas C30742-33-050-X. The neutron source is the thermal Sub-critical Multiplication complex (SM1) moderated with water, located at the University of Pavia (Italy). We report the change of SiPMs most important electric parameters: dark current, dark pulse frequency, gain, direct bias resistance, as a function of the integrated neutron fluency.

Acoustic properties of supersonic helium/air jets at low Reynolds numbers

NASA Technical Reports Server (NTRS)

Mclaughlin, Dennis K.; Barron, W. D.; Vaddempudi, Appa R.

1992-01-01

Experiments have been performed with the objective of developing a greater understanding of the physics of hot supersonic jet noise. Cold helium/air jets are used to easily and inexpensively simulate the low densities of hot air jets. The experiments are conducted at low Reynolds numbers in order to facilitate study of the large-scale turbulent structures (instability waves) that cause most of the radiated noise. Experiments have been performed on Mach 1.5 and 2.1 jets of pure air, pure helium and 10 percent helium by mass. Helium/air jets are shown to radiate more noise than pure air jets due to the increased exit velocity. Microphone spectra are usually dominated by a single spectral component at a predictable frequency. Increasing the jet's helium concentration is shown to increase the dominant frequency. The helium concentration in the test chamber is determined by calculating the speed of sound from the measured phase difference between two microphone signals. Bleeding outside air into the test chamber controls the accumulation of helium so that the hot jet simulation remains valid. The measured variation in the peak radiated noise frequency is in good agreement with the predictions of the hot jet noise theory of Tam et al.

A survey of the Australasian clinical medical physics and biomedical engineering workforce.

PubMed

Round, W H

2007-03-01

A survey of the medical physics and biomedical engineering workforce was carried out in 2006. 495 positions (equivalent to 478 equivalent full time (EFT) positions) were captured by the survey. Of these 268 EFT were in radiation oncology physics, 36 EFT were in radiology physics, 44 were in nuclear medicine physics, 101 EFT were in biomedical engineering and 29 EFT were attributed to other activities. The survey reviewed the experience profile, the salary levels and the number of vacant positions in the workforce for the different disciplines in each Australian state and in New Zealand. Analysis of the data identifies staffing shortfalls in the various disciplines and demonstrates the difficulties that will occur in trying to train sufficient physicists to raise staffing to an acceptable level.

A 2009 survey of the Australasian clinical medical physics and biomedical engineering workforce.

PubMed

Round, W Howell

2010-06-01

A survey of the Australasian clinical medical physics and biomedical engineering workforce was carried out in 2009 following on from a similar survey in 2006. 621 positions (equivalent to 575 equivalent full time (EFT) positions) were captured by the survey. Of these 330 EFT were in radiation oncology physics, 45 EFT were in radiology physics, 42 EFT were in nuclear medicine physics, 159 EFT were in biomedical engineering and 29 EFT were attributed to other activities. The survey reviewed the experience profile, the salary levels and the number of vacant positions in the workforce for the different disciplines in each Australian state and in New Zealand. Analysis of the data shows the changes to the workforce over the preceding 3 years and identifies shortfalls in the workforce.

Applications of Accelerators and Radiation Sources in the Field of Space Research and Industry.

PubMed

Campajola, Luigi; Di Capua, Francesco

2016-12-01

Beyond their important economic role in commercial communications, satellites in general are critical infrastructure because of the services they provide. In addition to satellites providing information which facilitates a better understanding of the space environment and improved performance of physics experiments, satellite observations are also used to actively monitor weather, geological processes, agricultural development and the evolution of natural and man-made hazards. Defence agencies depend on satellite services for communication in remote locations, as well as for reconnaissance and intelligence. Both commercial and government users rely on communication satellites to provide communication in the event of a disaster that damages ground-based communication systems, provide news, education and entertainment to remote areas and connect global businesses. The space radiation environment is an hazard to most satellite missions and can lead to extremely difficult operating conditions for all of the equipment travelling in space. Here, we first provide an overview of the main components of space radiation environment, followed by a description of the basic mechanism of the interaction of radiation with matter. This is followed by an introduction to the space radiation hardness assurance problem and the main effects of natural radiation to the microelectronics (total ionizing dose, displacement damage and the single-event effect and a description of how different effects occurring in the space can be tested in on-ground experiments by using particle accelerators and radiation sources. We also discuss standards and the recommended procedures to obtain reliable results.

FROM THE HISTORY OF PHYSICS: The extraordinarily beautiful physical principle of thermonuclear charge design (on the occasion of the 50th anniversary of the test of RDS-37 — the first Soviet two-stage thermonuclear charge)

NASA Astrophysics Data System (ADS)

Goncharov, German A.

2005-11-01

On 22 November 1955, the Semipalatinsk test site saw the test of the first domestic two-stage thermonuclear RDS-37 charge. The charge operation was based on the principle of radiation implosion. The kernel of the principle consists in the radiation generated in a primary A-bomb explosion and confined by the radiation-opaque casing propagating throughout the interior casing volume and flowing around the secondary thermonuclear unit. The secondary unit experiences a strong compression under the irradiation, with a resulting nuclear and thermonuclear explosion. The RDS-37 explosion was the strongest of all those ever realized at the Semipalatinsk test site. It produced an indelible impression on the participants in the test. This document-based paper describes the genesis of the ideas underlying the RDS-37 design and reflects the critical moments in its development. The advent of RDS-37 was an outstanding accomplishment of the scientists and engineers of our country.

A parallel multi-domain solution methodology applied to nonlinear thermal transport problems in nuclear fuel pins

DOE PAGES

Philip, Bobby; Berrill, Mark A.; Allu, Srikanth; ...

2015-01-26

We describe an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors are described. The details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstratingmore » the achieved efficiency of the algorithm are presented. Moreover, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods. Finally, we demonstrate the power of the coupling methodology by considering problems with couplings between surface and volume physics and coupling of nonlinear thermal transport in fuel rods to an external radiation transport code.« less

The biological effects of space radiation during long stays in space.

PubMed

Ohnishi, Ken; Ohnishi, Takeo

2004-12-01

Many space experiments are scheduled for the International Space Station (ISS). Completion of the ISS will soon become a reality. Astronauts will be exposed to low-level background components from space radiation including heavy ions and other high-linear energy transfer (LET) radiation. For long-term stay in space, we have to protect human health from space radiation. At the same time, we should recognize the maximum permissible doses of space radiation. In recent years, physical monitoring of space radiation has detected about 1 mSv per day. This value is almost 150 times higher than that on the surface of the Earth. However, the direct effects of space radiation on human health are currently unknown. Therefore, it is important to measure biological dosimetry to calculate relative biological effectiveness (RBE) for human health during long-term flight. The RBE is possibly modified by microgravity. In order to understand the exact RBE and any interaction with microgravity, the ISS centrifugation system will be a critical tool, and it is hoped that this system will be in operation as soon as possible.

Radiation research society 1952-2002. Physics as an element of radiation research.

PubMed

Inokuti, Mitio; Seltzer, Stephen M

2002-07-01

Since its inception in 1954, Radiation Research has published an estimated total of about 8700 scientific articles up to August 2001, about 520, or roughly 6%, of which are primarily related to physics. This average of about 11 articles per year indicates steadily continuing contributions by physicists, though there are appreciable fluctuations from year to year. These works of physicists concern radiation sources, dosimetry, instrumentation for measurements of radiation effects, fundamentals of radiation physics, mechanisms of radiation actions, and applications. In this review, we have selected some notable accomplishments for discussion and present an outlook for the future.

Factors influencing radiation therapy student clinical placement satisfaction

PubMed Central

Bridge, Pete; Carmichael, Mary-Ann

2014-01-01

Introduction: Radiation therapy students at Queensland University of Technology (QUT) attend clinical placements at five different clinical departments with varying resources and support strategies. This study aimed to determine the relative availability and perceived importance of different factors affecting student support while on clinical placement. The purpose of the research was to inform development of future support mechanisms to enhance radiation therapy students’ experience on clinical placement. Methods: This study used anonymous Likert-style surveys to gather data from years 1 and 2 radiation therapy students from QUT and clinical educators from Queensland relating to availability and importance of support mechanisms during clinical placements in a semester. Results: The study findings demonstrated student satisfaction with clinical support and suggested that level of support on placement influenced student employment choices. Staff support was perceived as more important than physical resources; particularly access to a named mentor, a clinical educator and weekly formative feedback. Both students and educators highlighted the impact of time pressures. Conclusions: The support offered to radiation therapy students by clinical staff is more highly valued than physical resources or models of placement support. Protected time and acknowledgement of the importance of clinical education roles are both invaluable. Joint investment in mentor support by both universities and clinical departments is crucial for facilitation of effective clinical learning. PMID:26229635

Recent developments in Geant4

DOE PAGES

Allison, J.; Amako, K.; Apostolakis, J.; ...

2016-07-01

Geant4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. In conclusion, the adaptation of Geant4 to multithreading, advances in physics, detector modeling and visualization, extensions tomore » the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here.« less

Transversality of electromagnetic waves in the calculus-based introductory physics course

NASA Astrophysics Data System (ADS)

Burko, Lior M.

2008-11-01

Introductory calculus-based physics textbooks state that electromagnetic waves are transverse and list many of their properties, but most such textbooks do not bring forth arguments why this is so. Both physical and theoretical arguments are at a level appropriate for students of courses based on such books, and could be readily used by instructors of such courses. Here, we discuss two physical arguments (based on polarization experiments and on lack of monopole electromagnetic radiation) and the full argument for the transversality of (plane) electromagnetic waves based on the integral Maxwell equations. We also show, at a level appropriate for the introductory course, why the electric and magnetic fields in a wave are in phase and the relation of their magnitudes.

21 CFR 900.12 - Quality standards.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MAMMOGRAPHY... to mammography. The training shall include instruction in radiation physics, including radiation physics specific to mammography, radiation effects, and radiation protection. The mammographic...

The physical basis and future of radiation therapy.

PubMed

Bortfeld, T; Jeraj, R

2011-06-01

The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued "fuelling" of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more "professionalism" in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics.

The physical basis and future of radiation therapy

PubMed Central

Bortfeld, T; Jeraj, R

2011-01-01

The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued “fuelling” of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more “professionalism” in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics. PMID:21606068

Medical Physicists and AAPM

NASA Astrophysics Data System (ADS)

Amols, Howard

2006-03-01

The American Association of Physicists in Medicine (AAPM), a member society of the AIP is the largest professional society of medical physicists in the world with nearly 5700 members. Members operate in medical centers, university and community hospitals, research laboratories, industry, and private practice. Medical physics specialties include radiation therapy physics, medical diagnostic and imaging physics, nuclear medicine physics, and medical radiation safety. The majority of AAPM members are based in hospital departments of radiation oncology or radiology and provide technical support for patient diagnosis and treatment in a clinical environment. Job functions include support of clinical care, calibration and quality assurance of medical devices such as linear accelerators for cancer therapy, CT, PET, MRI, and other diagnostic imaging devices, research, and teaching. Pathways into a career in medical physics require an advanced degree in medical physics, physics, engineering, or closely related field, plus clinical training in one or more medical physics specialties (radiation therapy physics, imaging physics, or radiation safety). Most clinically based medical physicists also obtain certification from the American Board of Radiology, and some states require licensure as well.

Prejudice and Health Anxiety about Radiation Exposure from Second-Generation Atomic Bomb Survivors: Results from a Qualitative Interview Study

PubMed Central

Kamite, Yuka

2017-01-01

The effect of atomic bomb radiation exposure on the survivors and their children has been a worrisome problem since soon after the 1945 Hiroshima and Nagasaki bombings. Researchers have examined physical and genetic effects; however, no research has focused on second-generation survivors’ (SGS) psychological effects. Consequently, this study shed light on the SGS’ experience of discrimination and prejudice and their anxiety concerning the genetic effects of radiation exposure. This study utilized semi-structured interviews with 14 SGS (10 women, mean age = 56 ± 6.25 years, range = 46–68 years). Data were analyzed using a modified version of the grounded theory approach. Three categories were extracted: low awareness as an SGS, no health anxiety regarding the effect of radiation, and health anxiety regarding the effect of radiation. The results did not reveal that SGS who grew up in the bombed areas experienced discrimination or prejudice. They had little health anxiety from childhood to adolescence. In this study, some of the SGS developed health anxiety about their third-generation children, but only among female participants. Perhaps the transgenerational transmission of anxiety concerning the genetic effects of radiation exposure causes stress, particularly among women with children. However, a change was seen in adulthood health anxiety regarding the effects of radiation, suggesting the possibility that changes in the psychological experiences of SGS can be observed throughout their lifetimes and that their own health status, and that of their children, the third-generation survivors, affects their health anxiety regarding radiation. PMID:28912738

Prejudice and Health Anxiety about Radiation Exposure from Second-Generation Atomic Bomb Survivors: Results from a Qualitative Interview Study.

PubMed

Kamite, Yuka

2017-01-01

The effect of atomic bomb radiation exposure on the survivors and their children has been a worrisome problem since soon after the 1945 Hiroshima and Nagasaki bombings. Researchers have examined physical and genetic effects; however, no research has focused on second-generation survivors' (SGS) psychological effects. Consequently, this study shed light on the SGS' experience of discrimination and prejudice and their anxiety concerning the genetic effects of radiation exposure. This study utilized semi-structured interviews with 14 SGS (10 women, mean age = 56 ± 6.25 years, range = 46-68 years). Data were analyzed using a modified version of the grounded theory approach. Three categories were extracted: low awareness as an SGS, no health anxiety regarding the effect of radiation, and health anxiety regarding the effect of radiation. The results did not reveal that SGS who grew up in the bombed areas experienced discrimination or prejudice. They had little health anxiety from childhood to adolescence. In this study, some of the SGS developed health anxiety about their third-generation children, but only among female participants. Perhaps the transgenerational transmission of anxiety concerning the genetic effects of radiation exposure causes stress, particularly among women with children. However, a change was seen in adulthood health anxiety regarding the effects of radiation, suggesting the possibility that changes in the psychological experiences of SGS can be observed throughout their lifetimes and that their own health status, and that of their children, the third-generation survivors, affects their health anxiety regarding radiation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprawls, P

Purpose: To enhance the understanding of medical physics concepts and develop higher levels of learning relating to invisible physics phenomena such as radiation. To provide medical physics educators in all countries of the world with understanding of knowledge structures in the human brain, the different levels of learning, and the types of knowledge required for higher level functions such as problem solving, creative innovations, and applied clinical applications. To provide medical physics educators with an open access resource (tool) that they can use in their teaching activities to enrich and elevate the level of learning for their students, residents, etc.more » with respect to the invisible realm of medical physics. Methods: An experienced clinical medical physicist and educator has created and provided with open access three complementary web-based resources to achieve the purposes described above. One is a module focusing on the medical physics learning process with respect to mental knowledge structures, how they relate to outcomes and applications, and learning activities that are required to develop the required knowledge structures. The second is an extensive set of visuals that educators can use in their activities (classes, small group discussions, etc.) to visualize the invisible. The third is an interactive online simulation where learners can adjust factors and visually observe changes in x-radiation.These resources are available online at www.BLINDED FOR REVIEW . Results: Medical physics education, especially for non-physicists, is becoming much more interesting and useful especially with respect to invisible radiation. The global impact is that medical imaging professionals can be more effective in optimizing x-ray imaging procedures and risk management when they have knowledge levels that enhance problem solving, innovation, and creativity. Conclusion: Medical physics educators in all institutions can be much more effective and efficient in the sharing of their knowledge and experience when enhanced with high-quality visuals.« less

Radiation Oncology Physics and Medical Physics Education

NASA Astrophysics Data System (ADS)

Bourland, Dan

2011-10-01

Medical physics, an applied field of physics, is the applications of physics in medicine. Medical physicists are essential professionals in contemporary healthcare, contributing primarily to the diagnosis and treatment of diseases through numerous inventions, advances, and improvements in medical imaging and cancer treatment. Clinical service, research, and teaching by medical physicists benefits thousands of patients and other individuals every day. This talk will cover three main topics. First, exciting current research and development areas in the medical physics sub-specialty of radiation oncology physics will be described, including advanced oncology imaging for treatment simulation, image-guided radiation therapy, and biologically-optimized radiation treatment. Challenges in patient safety in high-technology radiation treatments will be briefly reviewed. Second, the educational path to becoming a medical physicist will be reviewed, including undergraduate foundations, graduate training, residency, board certification, and career opportunities. Third, I will introduce the American Association of Physicists in Medicine (AAPM), which is the professional society that represents, advocates, and advances the field of medical physics (www.aapm.org).

The Sao Paulo Microtron: Equipment and Planned Experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martins, M. N.; Maidana, N. L.; Vanin, V. R.

2007-10-26

The Linear Accelerator Laboratory (LAL) of the Instituto de Fisica da Universidade de Sao Paulo (IFUSP) is building a two-stage racetrack microtron, which will generate continuous wave electron beams with energies up to 38 MeV. This paper describes the characteristics of the accelerator, and reports on the experimental equipment that will be available in order to pursue the photonuclear physics research program. Operation will begin with the first stage (5 MeV), and concentrate on NRF (Nuclear Resonance Fluorescence) measurements and radiation physics studies. Planned experiments for the second stage explore the cw character of the beam on coincidence experiments. Amore » photon tagger has been already tested with radioactive sources and is ready to be installed. Gamma and neutron detector arrays are being developed for the detailed study of photoneutron reactions. Plans include the study of NRF and pygmy resonances, near the neutron binding energy.« less

Heat transfer from nanoparticles: a corresponding state analysis.

PubMed

Merabia, Samy; Shenogin, Sergei; Joly, Laurent; Keblinski, Pawel; Barrat, Jean-Louis

2009-09-08

In this contribution, we study situations in which nanoparticles in a fluid are strongly heated, generating high heat fluxes. This situation is relevant to experiments in which a fluid is locally heated by using selective absorption of radiation by solid particles. We first study this situation for different types of molecular interactions, using models for gold particles suspended in octane and in water. As already reported in experiments, very high heat fluxes and temperature elevations (leading eventually to particle destruction) can be observed in such situations. We show that a very simple modeling based on Lennard-Jones (LJ) interactions captures the essential features of such experiments and that the results for various liquids can be mapped onto the LJ case, provided a physically justified (corresponding state) choice of parameters is made. Physically, the possibility of sustaining very high heat fluxes is related to the strong curvature of the interface that inhibits the formation of an insulating vapor film.

Benchmarking Geant4 for simulating galactic cosmic ray interactions within planetary bodies

DOE PAGES

Mesick, K. E.; Feldman, W. C.; Coupland, D. D. S.; ...

2018-06-20

Galactic cosmic rays undergo complex nuclear interactions with nuclei within planetary bodies that have little to no atmosphere. Radiation transport simulations are a key tool used in understanding the neutron and gamma-ray albedo coming from these interactions and tracing these signals back to geochemical composition of the target. In this paper, we study the validity of the code Geant4 for simulating such interactions by comparing simulation results to data from the Apollo 17 Lunar Neutron Probe Experiment. Different assumptions regarding the physics are explored to demonstrate how these impact the Geant4 simulation results. In general, all of the Geant4 resultsmore » over-predict the data, however, certain physics lists perform better than others. Finally, in addition, we show that results from the radiation transport code MCNP6 are similar to those obtained using Geant4.« less

Benchmarking Geant4 for simulating galactic cosmic ray interactions within planetary bodies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mesick, K. E.; Feldman, W. C.; Coupland, D. D. S.

Galactic cosmic rays undergo complex nuclear interactions with nuclei within planetary bodies that have little to no atmosphere. Radiation transport simulations are a key tool used in understanding the neutron and gamma-ray albedo coming from these interactions and tracing these signals back to geochemical composition of the target. In this paper, we study the validity of the code Geant4 for simulating such interactions by comparing simulation results to data from the Apollo 17 Lunar Neutron Probe Experiment. Different assumptions regarding the physics are explored to demonstrate how these impact the Geant4 simulation results. In general, all of the Geant4 resultsmore » over-predict the data, however, certain physics lists perform better than others. Finally, in addition, we show that results from the radiation transport code MCNP6 are similar to those obtained using Geant4.« less

Lanthanide/Actinide Opacities

NASA Astrophysics Data System (ADS)

Hungerford, Aimee; Fontes, Christopher J.

2018-06-01

Gravitational wave observations benefit from accompanying electromagnetic signals in order to accurately determine the sky positions of the sources. The ejecta of neutron star mergers are expected to produce such electromagnetic transients, called macronovae (e.g. the recent and unprecedented observation of GW170817). Characteristics of the ejecta include large velocity gradients and the presence of heavy r-process elements, which pose significant challenges to the accurate calculation of radiative opacities and radiation transport. Opacities include a dense forest of bound-bound features arising from near-neutral lanthanide and actinide elements. Here we present an overview of current theoretical opacity determinations that are used by neutron star merger light curve modelers. We will touch on atomic physics and plasma modeling codes that are used to generate these opacities, as well as the limited body of laboratory experiments that may serve as points of validation for these complex atomic physics calculations.

An overview of η and η‧ decays at BESIII

NASA Astrophysics Data System (ADS)

Fang, Shuang-shi; Kupsc, Andrzej; Wei, Dai-hui

2018-04-01

The world’s largest sample of J/ψ events, 1.31 billion events accumulated at the BESIII detector, provides a unique opportunity to investigate η and η‧ physics via two-body J/ψ radiative or hadronic decays. For many η‧ decay channels the low background data samples are up to three orders of magnitude larger than collected in any previous experiment. Here we review the most significant results on η and η‧ obtained at BESIII so far. The analyses range from detailed studies of common decay dynamics, observations of new radiative and Dalitz decays, and searches for rare/forbidden decays with sensitivity up to ℬ ∼ 10‑5. Finally, prospects of forthcoming runs at the J/ψ peak for η and η‧ physics are discussed. Supported by National Natural Science Foundation of China (NSFC) (11565006, 11675184, 11735014)

Radiation-driven hydrodynamics of long pulse hohlraums on the National Ignition Facility*,**

NASA Astrophysics Data System (ADS)

Dewald, Eduard

2005-10-01

The first hohlraum experiments have been performed at the National Ignition Facility (NIF) in support of indirect drive Inertial Confinement Fusion (ICF) and High Energy Density Physics. Vacuum hohlraums have been irradiated with laser powers up to 8 TW, 1-9 ns pulse lengths and energies up to 17 kJ to activate several hohlraum drive diagnostics, to study the radiation temperature scaling with the laser power and hohlraum size, and to make contact with hohlraum experiments performed at the NOVA and Omega laser facilities. The vacuum hohlraums yield low laser backscattering and hot electron fractions, and the hohlraum radiation temperature measured with a newly activated 18 channel Dante soft x-ray power diagnostic agrees well with two-dimensional LASNEX calculations. Using the unique feature of NIF to deliver long steady laser drives, these hohlraum experiments have also validated analytical models and LASNEX calculations of hohlraum plasma filling as evidenced by time-resolved hard x-ray imaging and coronal hohlraum radiation production measured by Dante. Analytical modeling used to estimate hohlraum radiation limits due to plasma filling is in agreement with measurements and predicts for full NIF system with peak powers up to 500 TW peak radiation temperatures that are considerably higher than required in ICF designs. * Work performed in collaboration with L.J. Suter, O.L. Landen, J. Schein, K. Campbell, M.S. Schneider, J. Holder, S.H. Glenzer, J.W. McDonald, C. Niemann, A.J. Mackinnon, D.H. Kalantar, C. Haynam, S. Dixit **This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.

The PEREGRINETM program: using physics and computer simulation to improve radiation therapy for cancer

NASA Astrophysics Data System (ADS)

Hartmann Siantar, Christine L.; Moses, Edward I.

1998-11-01

When using radiation to treat cancer, doctors rely on physics and computer technology to predict where the radiation dose will be deposited in the patient. The accuracy of computerized treatment planning plays a critical role in the ultimate success or failure of the radiation treatment. Inaccurate dose calculations can result in either insufficient radiation for cure, or excessive radiation to nearby healthy tissue, which can reduce the patient's quality of life. This paper describes how advanced physics, computer, and engineering techniques originally developed for nuclear weapons and high-energy physics research are being used to predict radiation dose in cancer patients. Results for radiation therapy planning, achieved in the Lawrence Livermore National Laboratory (LLNL) 0143-0807/19/6/005/img2 program show that these tools can give doctors new insights into their patients' treatments by providing substantially more accurate dose distributions than have been available in the past. It is believed that greater accuracy in radiation therapy treatment planning will save lives by improving doctors' ability to target radiation to the tumour and reduce suffering by reducing the incidence of radiation-induced complications.

Galactic Cosmic Ray Event-Based Risk Model (GERM) Code

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.; Plante, Ianik; Ponomarev, Artem L.; Kim, Myung-Hee Y.

2013-01-01

This software describes the transport and energy deposition of the passage of galactic cosmic rays in astronaut tissues during space travel, or heavy ion beams in patients in cancer therapy. Space radiation risk is a probability distribution, and time-dependent biological events must be accounted for physical description of space radiation transport in tissues and cells. A stochastic model can calculate the probability density directly without unverified assumptions about shape of probability density function. The prior art of transport codes calculates the average flux and dose of particles behind spacecraft and tissue shielding. Because of the signaling times for activation and relaxation in the cell and tissue, transport code must describe temporal and microspatial density of functions to correlate DNA and oxidative damage with non-targeted effects of signals, bystander, etc. These are absolutely ignored or impossible in the prior art. The GERM code provides scientists data interpretation of experiments; modeling of beam line, shielding of target samples, and sample holders; and estimation of basic physical and biological outputs of their experiments. For mono-energetic ion beams, basic physical and biological properties are calculated for a selected ion type, such as kinetic energy, mass, charge number, absorbed dose, or fluence. Evaluated quantities are linear energy transfer (LET), range (R), absorption and fragmentation cross-sections, and the probability of nuclear interactions after 1 or 5 cm of water equivalent material. In addition, a set of biophysical properties is evaluated, such as the Poisson distribution for a specified cellular area, cell survival curves, and DNA damage yields per cell. Also, the GERM code calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle in a selected material. The GERM code makes the numerical estimates of basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at the NASA Space Radiation Laboratory (NSRL) for the purpose of simulating space radiation biological effects. In the first option, properties of monoenergetic beams are treated. In the second option, the transport of beams in different materials is treated. Similar biophysical properties as in the first option are evaluated for the primary ion and its secondary particles. Additional properties related to the nuclear fragmentation of the beam are evaluated. The GERM code is a computationally efficient Monte-Carlo heavy-ion-beam model. It includes accurate models of LET, range, residual energy, and straggling, and the quantum multiple scattering fragmentation (QMSGRG) nuclear database.

CubeSat: Colorado Student Space Weather Experiment

NASA Astrophysics Data System (ADS)

Li, X.; Palo, S. E.; Turner, D. L.; Gerhardt, D.; Redick, T.; Tao, J.

2009-12-01

Energetic particles, electrons and protons either directly associated with solar flares or trapped in the terrestrial radiation belt, have a profound space weather impact. A 3U CubeSat mission with a single instrument, Relativistic Electrons and Proton Telescope integrated little experiment (REPTile), is proposed to address fundamental questions relating to the relationship between solar flares and energetic particles and the acceleration and loss mechanism of outer radiation belt electrons. REPTile, in a highly inclined low earth orbit, will measure differential fluxes of relativistic electrons in the energy range of 0.5-3.5 MeV and protons in 10-40 MeV. This project is a collaborative effort between the Laboratory for Atmospheric and Space Physics and the Department of Aerospace Engineering Sciences at the University of Colorado, which includes the integration of students, faculty, and professional engineers.

On the Determination of the Emission Wavelength of an Infrared LED with Common Laboratory Instruments

ERIC Educational Resources Information Center

RayChaudhuri, Barun

2011-01-01

This work demonstrates an experiment on the optoelectronic properties of a p-n junction suitable for students of undergraduate physics. It investigates, from an educational point of view, the origin of the wavelength of radiation emitted by a light emitting diode (LED) and determines the emission wavelength of an infrared LED without using…

Dosimetry in small-animal CT using Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Lee, C.-L.; Park, S.-J.; Jeon, P.-H.; Jo, B.-D.; Kim, H.-J.

2016-01-01

Small-animal computed tomography (micro-CT) imaging devices are increasingly being used in biological research. While investigators are mainly interested in high-contrast, low-noise, and high-resolution anatomical images, relatively large radiation doses are required, and there is also growing concern over the radiological risk from preclinical experiments. This study was conducted to determine the radiation dose in a mouse model for dosimetric estimates using the GEANT4 application for tomographic emission simulations (GATE) and to extend its techniques to various small-animal CT applications. Radiation dose simulations were performed with the same parameters as those for the measured micro-CT data, using the MOBY phantom, a pencil ion chamber and an electrometer with a CT detector. For physical validation of radiation dose, absorbed dose of brain and liver in mouse were evaluated to compare simulated results with physically measured data using thermoluminescent dosimeters (TLDs). The mean difference between simulated and measured data was less than 2.9% at 50 kVp X-ray source. The absorbed doses of 37 brain tissues and major organs of the mouse were evaluated according to kVp changes. The absorbed dose over all of the measurements in the brain (37 types of tissues) consistently increased and ranged from 42.4 to 104.0 mGy. Among the brain tissues, the absorbed dose of the hypothalamus (157.8-414.30 mGy) was the highest for the beams at 50-80 kVp, and that of the corpus callosum (11.2-26.6 mGy) was the lowest. These results can be used as a dosimetric database to control mouse doses and preclinical targeted radiotherapy experiments. In addition, to accurately calculate the mouse-absorbed dose, the X-ray spectrum, detector alignment, and uncertainty in the elemental composition of the simulated materials must be accurately modeled.

Select strengths and biases of models in representing the Arctic winter boundary layer over sea ice: the Larcform 1 single column model intercomparison

PubMed Central

Pithan, Felix; Ackerman, Andrew; Angevine, Wayne M.; Hartung, Kerstin; Ickes, Luisa; Kelley, Maxwell; Medeiros, Brian; Sandu, Irina; Steeneveld, Gert-Jan; Sterk, HAM; Svensson, Gunilla; Vaillancourt, Paul A.; Zadra, Ayrton

2017-01-01

Weather and climate models struggle to represent lower tropospheric temperature and moisture profiles and surface fluxes in Arctic winter, partly because they lack or misrepresent physical processes that are specific to high latitudes. Observations have revealed two preferred states of the Arctic winter boundary layer. In the cloudy state, cloud liquid water limits surface radiative cooling, and temperature inversions are weak and elevated. In the radiatively clear state, strong surface radiative cooling leads to the build-up of surface-based temperature inversions. Many large-scale models lack the cloudy state, and some substantially underestimate inversion strength in the clear state. Here, the transformation from a moist to a cold dry air mass is modelled using an idealized Lagrangian perspective. The trajectory includes both boundary layer states, and the single-column experiment is the first Lagrangian Arctic air formation experiment (Larcform 1) organized within GEWEX GASS (Global atmospheric system studies). The intercomparison reproduces the typical biases of large-scale models: Some models lack the cloudy state of the boundary layer due to the representation of mixed-phase micro-physics or to the interaction between micro-and macrophysics. In some models, high emissivities of ice clouds or the lack of an insulating snow layer prevent the build-up of surface-based inversions in the radiatively clear state. Models substantially disagree on the amount of cloud liquid water in the cloudy state and on turbulent heat fluxes under clear skies. Observations of air mass transformations including both boundary layer states would allow for a tighter constraint of model behaviour. PMID:28966718

Select strengths and biases of models in representing the Arctic winter boundary layer over sea ice: the Larcform 1 single column model intercomparison.

PubMed

Pithan, Felix; Ackerman, Andrew; Angevine, Wayne M; Hartung, Kerstin; Ickes, Luisa; Kelley, Maxwell; Medeiros, Brian; Sandu, Irina; Steeneveld, Gert-Jan; Sterk, Ham; Svensson, Gunilla; Vaillancourt, Paul A; Zadra, Ayrton

2016-09-01

Weather and climate models struggle to represent lower tropospheric temperature and moisture profiles and surface fluxes in Arctic winter, partly because they lack or misrepresent physical processes that are specific to high latitudes. Observations have revealed two preferred states of the Arctic winter boundary layer. In the cloudy state, cloud liquid water limits surface radiative cooling, and temperature inversions are weak and elevated. In the radiatively clear state, strong surface radiative cooling leads to the build-up of surface-based temperature inversions. Many large-scale models lack the cloudy state, and some substantially underestimate inversion strength in the clear state. Here, the transformation from a moist to a cold dry air mass is modelled using an idealized Lagrangian perspective. The trajectory includes both boundary layer states, and the single-column experiment is the first L agrangian Arc tic air form ation experiment (Larcform 1) organized within GEWEX GASS (Global atmospheric system studies). The intercomparison reproduces the typical biases of large-scale models: Some models lack the cloudy state of the boundary layer due to the representation of mixed-phase micro-physics or to the interaction between micro-and macrophysics. In some models, high emissivities of ice clouds or the lack of an insulating snow layer prevent the build-up of surface-based inversions in the radiatively clear state. Models substantially disagree on the amount of cloud liquid water in the cloudy state and on turbulent heat fluxes under clear skies. Observations of air mass transformations including both boundary layer states would allow for a tighter constraint of model behaviour.

Radiation protection and environmental management at the relativistic heavy ion collider.

PubMed

Musolino, S V; Briggs, S L; Stevens, A J

2001-01-01

The Relativistic Heavy Ion Collider (RHIC) is a high energy hadron accelerator built to study basic nuclear physics. It consists of two counter-rotating beams of fully stripped gold ions that are accelerated in two rings to an energy of 100 GeV/nucleon or protons at 250 GeV/c. The beams can be stored for a period of five to ten hours and brought into collision for experiments during that time. The first major physics objective is to recreate a state of matter, the quark-gluon plasma, that has been predicted to have existed at a short time after the creation of the universe. Because there are only a few other high energy particle accelerators like RHIC in the world, the rules promulgated in the US Code of Federal Regulations under the Atomic Energy Act, State regulations, or international guidance documents do not cover prompt radiation from accelerators to govern directly the design and operation of a superconducting collider. Special design criteria for prompt radiation were developed to provide guidance tor the design of radiation shielding. Environmental Management at RHIC is accomplished through the ISO 14001 Environmental Management System. The applicability, benefits, and implementation of ISO 14001 within the framework of a large research accelerator complex are discussed in the paper.

Particle Radiation Therapy for Gastrointestinal Malignancies

PubMed Central

Meyer, Jeffrey J.; Willett, Christopher G.

2007-01-01

Treatment-related toxicity is common in the radiotherapeutic management of cancers of the gastrointestinal tract. These toxicities can diminish treatment efficacy by necessitating treatment breaks, limiting the radiation dose that can be delivered, and hindering concomitant use of chemotherapy and targeted drug agents. Many efforts have focused on widening the gap between the likelihood of tumor control and the likelihood of toxicities associated with radiation. Use of particles that exhibit a Bragg peak phenomenon in their interactions with tissue, such as protons, heavier ions like carbon ions, and pions, is one means of concentrating radiation dose in tumors and away from normal tissues. Neutron beams have also been used in the treatment of gastrointestinal cancers in an effort to take advantage of their potent biologic effects. This report reviews basic particle radiation physics and biology, as well as the clinical experience with protons, heavier ions, pions, and neutrons in the treatment of various gastrointestinal malignancies. Potential future directions in clinical research with particle therapy are discussed. PMID:19360149

Management of ionizing radiation injuries and illnesses, part 1: physics, radiation protection, and radiation instrumentation.

PubMed

Christensen, Doran M; Jenkins, Mark S; Sugarman, Stephen L; Glassman, Erik S

2014-03-01

Ionizing radiation injuries and illnesses are exceedingly rare; therefore, most physicians have never managed such conditions. When confronted with a possible radiation injury or illness, most physicians must seek specialty consultation. Protection of responders, health care workers, and patients is an absolute priority for the delivery of medical care. Management of ionizing radiation injuries and illnesses, as well as radiation protection, requires a basic understanding of physics. Also, to provide a greater measure of safety when working with radioactive materials, instrumentation for detection and identification of radiation is needed. Because any health care professional could face a radiation emergency, it is imperative that all institutions have emergency response plans in place before an incident occurs. The present article is an introduction to basic physics, ionizing radiation, radiation protection, and radiation instrumentation, and it provides a basis for management of the consequences of a radiologic or nuclear incident.

WE-D-303-00: Computational Phantoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, John; Brigham and Women’s Hospital and Dana-Farber Cancer Institute, Boston, MA

2015-06-15

Modern medical physics deals with complex problems such as 4D radiation therapy and imaging quality optimization. Such problems involve a large number of radiological parameters, and anatomical and physiological breathing patterns. A major challenge is how to develop, test, evaluate and compare various new imaging and treatment techniques, which often involves testing over a large range of radiological parameters as well as varying patient anatomies and motions. It would be extremely challenging, if not impossible, both ethically and practically, to test every combination of parameters and every task on every type of patient under clinical conditions. Computer-based simulation using computationalmore » phantoms offers a practical technique with which to evaluate, optimize, and compare imaging technologies and methods. Within simulation, the computerized phantom provides a virtual model of the patient’s anatomy and physiology. Imaging data can be generated from it as if it was a live patient using accurate models of the physics of the imaging and treatment process. With sophisticated simulation algorithms, it is possible to perform virtual experiments entirely on the computer. By serving as virtual patients, computational phantoms hold great promise in solving some of the most complex problems in modern medical physics. In this proposed symposium, we will present the history and recent developments of computational phantom models, share experiences in their application to advanced imaging and radiation applications, and discuss their promises and limitations. Learning Objectives: Understand the need and requirements of computational phantoms in medical physics research Discuss the developments and applications of computational phantoms Know the promises and limitations of computational phantoms in solving complex problems.« less

Fruit Flies Provide New Insights in Low-Radiation Background Biology at the INFN Underground Gran Sasso National Laboratory (LNGS).

PubMed

Morciano, Patrizia; Cipressa, Francesca; Porrazzo, Antonella; Esposito, Giuseppe; Tabocchini, Maria Antonella; Cenci, Giovanni

2018-06-04

Deep underground laboratories (DULs) were originally created to host particle, astroparticle or nuclear physics experiments requiring a low-background environment with vastly reduced levels of cosmic-ray particle interference. More recently, the range of science projects requiring an underground experiment site has greatly expanded, thus leading to the recognition of DULs as truly multidisciplinary science sites that host important studies in several fields, including geology, geophysics, climate and environmental sciences, technology/instrumentation development and biology. So far, underground biology experiments are ongoing or planned in a few of the currently operating DULs. Among these DULs is the Gran Sasso National Laboratory (LNGS), where the majority of radiobiological data have been collected. Here we provide a summary of the current scenario of DULs around the world, as well as the specific features of the LNGS and a summary of the results we obtained so far, together with other findings collected in different underground laboratories. In particular, we focus on the recent results from our studies of Drosophila melanogaster, which provide the first evidence of the influence of the radiation environment on life span, fertility and response to genotoxic stress at the organism level. Given the increasing interest in this field and the establishment of new projects, it is possible that in the near future more DULs will serve as sites of radiobiology experiments, thus providing further relevant biological information at extremely low-dose-rate radiation. Underground experiments can be nicely complemented with above-ground studies at increasing dose rate. A systematic study performed in different exposure scenarios provides a potential opportunity to address important radiation protection questions, such as the dose/dose-rate relationship for cancer and non-cancer risk, the possible existence of dose/dose-rate threshold(s) for different biological systems and/or end points and the possible role of radiation quality in triggering the biological response.

Simulations of radiation pressure experiments narrow down the energy and momentum of light in matter

NASA Astrophysics Data System (ADS)

Bethune-Waddell, Max; Chau, Kenneth J.

2015-12-01

Consensus on a single electrodynamic theory has yet to be reached. Discord was seeded over a century ago when Abraham and Minkowski proposed different forms of electromagnetic momentum density and has since expanded in scope with the gradual introduction of other forms of momentum and force densities. Although degenerate sets of electrodynamic postulates can be fashioned to comply with global energy and momentum conservation, hope remains to isolate a single theory based on detailed comparison between force density predictions and radiation pressure experiments. This comparison is two-fold challenging because there are just a handful of quantitative radiation pressure measurements over the past century and the solutions developed from different postulates, which consist of approximate expressions and inferential deductions, are scattered throughout the literature. For these reasons, it is appropriate to conduct a consolidated and comprehensive re-analysis of past experiments under the assumption that the momentum and energy of light in matter are degenerate. We create a combined electrodynamic/fluid dynamic simulation testbed that uses five historically significant sets of electrodynamic postulates, including those by Abraham and Minkowski, to model radiation pressure under diverse configurations with minimal assumptions. This leads to new interpretations of landmark investigations of light momentum, including the Balazs thought experiment, the Jones-Richards and Jones-Leslie measurements of radiation pressure on submerged mirrors, observations of laser-deformed fluid surfaces, and experiments on optical trapping and tractor beaming of dielectric particles. We discuss the merits and demerits of each set of postulates when compared to available experimental evidence and fundamental conservation laws. Of the five sets of postulates, the Abraham and Einstein-Laub postulates provide the greatest consistency with observations and the most physically plausible descriptions of electrodynamic interactions. Force density predictions made by these two postulates are unique under many conditions and their experimental isolation is potentially within reach.

The Space Experiment PAMELA

NASA Astrophysics Data System (ADS)

Boezio, M.; Bonvicini, V.; Mocchiutti, E.; Schiavon, P.; Vacchi, A.; Zampa, G.; Zampa, N.; Bakaldin, A.; Galper, A. M.; Koldashov, S. V.; Korotkov, M. G.; Mikhailov, V. V.; Voronov, S. A.; Yurkin, Y.; Basili, A.; Bencardino, R.; Bongiorno, L.; Casolino, M.; de Pascale, M. P.; Furano, G.; Menicucci, A.; Minori, M.; Morselli, A.; Picozza, P.; Sparvoli, R.; Wischnewski, R.; Adriani, O.; Bonechi, L.; Bongi, M.; Giambi, F.; Papini, P.; Ricciarini, S. B.; Spillantini, P.; Straulino, S.; Taccetti, F.; Vannuccini, E.; Castellini, G.; Carlson, P.; Lund, J.; Lundquist, J.; Orsi, S.; Pearce, M.; Barbarino, G. C.; Campana, D.; Osteria, G.; Rossi, G.; Russo, S.; Boscherini, M.; Menn, W.; Simon, M.; Ricci, M.; Ambriola, M.; Bellotti, R.; Cafagna, F.; Circella, M.; de Marzo, C.; Giglietto, N.; Mirizzi, N.; Romita, M.; Spinelli, P.; Bogomolov, E.; Krutkov, S.; Vasiljev, G.; Bazilevskaja, G.; Grigorjeva, A.; Mukhametshin, R.; Stozhkov, Y.; Mitchell, J. W.; Streitmatter, R. E.; Stochaj, S. J.

2004-09-01

We present in this paper a status report of the space experiment PAMELA. PAMELA is a satellite-borne experiment which primarily aims to measure the antiproton and positron spectra in the cosmic radiation over a large energy range (from 80 MeV up to 190 GeV for antiprotons and from 50 MeV up to 270 GeV for positrons) and to search for antinuclei with a sensitivity of the order of 10-8 in the antihelium/helium ratio. In addition, it will measure the light nuclear component of cosmic rays and investigate phenomena connected with Solar and Earth physics. The apparatus will be installed onboard the polar orbiting Resurs DK1 satellite, which will be launched into space by a Soyuz TM2 rocket in 2004 from Baikonur cosmodrome in Kazakhstan, for a 3 year long mission. PAMELA consists of: a time of flight system, a transition radiation detector, a magnetic spectrometer, an anticoincidence detector, an electromagnetic imaging calorimeter, a shower tail catcher scintillator and a neutron detector.

Using VISAR to assess the M-band isotropy in hohlraums

DOE PAGES

Lanier, Nicholas Edward; Kline, John L.; Morton, John

2016-09-27

In laser based radiation flow experiments, drive variability can often overwhelm the physics sensitivity that one seeks to quantify. Hohlraums can help by providing a more symmetrized, Planckian-like source. However, at higher temperatures, the hohlraum’s actual emission can deviate significantly from a truly blackbody, Lambertian source. At the National Ignition Facility (NIF), Dante provides the best quantification of hohlraum output. Unfortunately, limited diagnostic access coupled with NIF’s natural symmetry does not allow for Dante measurements at more than two angles. As part of the CEPHEUS campaign on NIF, proof-of-principle experiments to better quantify the gold M-band isotropy were conducted. Thesemore » experiments positioned beryllium/aluminum mirrors at differing angles, offset from the hohlraum. Filtering removes the thermal emission of the hohlraum and the remaining M-band radiation is preferentially absorbed in the aluminum layer. The subsequent hydrodynamic motion is measured via VISAR. Although indirect, this M-band measurement can be made at any angle.« less

Characterization, performance and optimization of PVDF as a piezoelectric film for advanced space mirror concepts.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Gary D.; Assink, Roger Alan; Dargaville, Tim Richard

2005-11-01

Piezoelectric polymers based on polyvinylidene fluoride (PVDF) are of interest for large aperture space-based telescopes as adaptive or smart materials. Dimensional adjustments of adaptive polymer films depend on controlled charge deposition. Predicting their long-term performance requires a detailed understanding of the piezoelectric material features, expected to suffer due to space environmental degradation. Hence, the degradation and performance of PVDF and its copolymers under various stress environments expected in low Earth orbit has been reviewed and investigated. Various experiments were conducted to expose these polymers to elevated temperature, vacuum UV, {gamma}-radiation and atomic oxygen. The resulting degradative processes were evaluated. Themore » overall materials performance is governed by a combination of chemical and physical degradation processes. Molecular changes are primarily induced via radiative damage, and physical damage from temperature and atomic oxygen exposure is evident as depoling, loss of orientation and surface erosion. The effects of combined vacuum UV radiation and atomic oxygen resulted in expected surface erosion and pitting rates that determine the lifetime of thin films. Interestingly, the piezo responsiveness in the underlying bulk material remained largely unchanged. This study has delivered a comprehensive framework for material properties and degradation sensitivities with variations in individual polymer performances clearly apparent. The results provide guidance for material selection, qualification, optimization strategies, feedback for manufacturing and processing, or alternative materials. Further material qualification should be conducted via experiments under actual space conditions.« less

Influence of cirrus clouds on weather and climate processes A global perspective

NASA Technical Reports Server (NTRS)

Liou, K.-N.

1986-01-01

Current understanding and knowledge of the composition and structure of cirrus clouds are reviewed and documented in this paper. In addition, the radiative properties of cirrus clouds as they relate to weather and climate processes are described in detail. To place the relevance and importance of cirrus composition, structure and radiative properties into a global perspective, pertinent results derived from simulation experiments utilizing models with varying degrees of complexity are presented; these have been carried out for the investigation of the influence of cirrus clouds on the thermodynamics and dynamics of the atmosphere. In light of these reviews, suggestions are outlined for cirrus-radiation research activities aimed toward the development and improvement of weather and climate models for a physical understanding of cause and effect relationships and for prediction purposes.

Attenuation of radiation from distributed gamma sources as a function of wall thickness of a concrete blockhouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmoke, M. A.; Rexroad, R. E.; Tiller, H. J.

1963-06-15

The experiment described constitutes part of the shielding program conducted by Army Nuclear Defense Laboratory and was designed to experimentally verify theoretical calculations used to predict the amount of radiation protection afforded by above-ground structures in a fallout radiation field. This method requires the knowledge of some physical parameters of a structure such as mass thickness of the walls and the geometric orientation of the detectors within the structure. From this information, a reduction factor for any given structure may be calculated. This Laboratory's experimental program was initially begun by measuring the attenuation of a simple structure with no complicatingmore » internal or external geometries and will proceed to more complex structures with basements, interior partitions, and upper floors. (auth)« less

KSC-02pd1655

NASA Image and Video Library

2002-10-26

KENNEDY SPACE CENTER, FLA. -- A truck containing the Solar Radiation and Climate Experiment (SORCE) spacecraft arrives at KSC. The spacecraft will undergo final processing for launch. SORCE is equipped with four instruments that will measure variations in solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. The SORCE project is managed by NASA's Goddard Space Flight Center. The instruments on the SORCE spacecraft are built by the Laboratory for Atmospheric and Space Physics (LASP). Launch of SORCE aboard a Pegasus XL rocket is scheduled for mid-December 2002. Launch site is Cape Canaveral Air Force Station, Fla.

SPECT3D - A multi-dimensional collisional-radiative code for generating diagnostic signatures based on hydrodynamics and PIC simulation output

NASA Astrophysics Data System (ADS)

MacFarlane, J. J.; Golovkin, I. E.; Wang, P.; Woodruff, P. R.; Pereyra, N. A.

2007-05-01

SPECT3D is a multi-dimensional collisional-radiative code used to post-process the output from radiation-hydrodynamics (RH) and particle-in-cell (PIC) codes to generate diagnostic signatures (e.g. images, spectra) that can be compared directly with experimental measurements. This ability to post-process simulation code output plays a pivotal role in assessing the reliability of RH and PIC simulation codes and their physics models. SPECT3D has the capability to operate on plasmas in 1D, 2D, and 3D geometries. It computes a variety of diagnostic signatures that can be compared with experimental measurements, including: time-resolved and time-integrated spectra, space-resolved spectra and streaked spectra; filtered and monochromatic images; and X-ray diode signals. Simulated images and spectra can include the effects of backlighters, as well as the effects of instrumental broadening and time-gating. SPECT3D also includes a drilldown capability that shows where frequency-dependent radiation is emitted and absorbed as it propagates through the plasma towards the detector, thereby providing insights on where the radiation seen by a detector originates within the plasma. SPECT3D has the capability to model a variety of complex atomic and radiative processes that affect the radiation seen by imaging and spectral detectors in high energy density physics (HEDP) experiments. LTE (local thermodynamic equilibrium) or non-LTE atomic level populations can be computed for plasmas. Photoabsorption rates can be computed using either escape probability models or, for selected 1D and 2D geometries, multi-angle radiative transfer models. The effects of non-thermal (i.e. non-Maxwellian) electron distributions can also be included. To study the influence of energetic particles on spectra and images recorded in intense short-pulse laser experiments, the effects of both relativistic electrons and energetic proton beams can be simulated. SPECT3D is a user-friendly software package that runs on Windows, Linux, and Mac platforms. A parallel version of SPECT3D is supported for Linux clusters for large-scale calculations. We will discuss the major features of SPECT3D, and present example results from simulations and comparisons with experimental data.

A 2012 survey of the Australasian clinical medical physics and biomedical engineering workforce.

PubMed

Round, W H

2013-06-01

A survey of the medical physics and biomedical engineering workforce in Australia and New Zealand was carried out in 2012 following on from similar surveys in 2009 and 2006. 761 positions (equivalent to 736 equivalent full time (EFT) positions) were captured by the survey. Of these, 428 EFT were in radiation oncology physics, 63 EFT were in radiology physics, 49 EFT were in nuclear medicine physics, 150 EFT were in biomedical engineering and 46 EFT were attributed to other activities. The survey reviewed the experience profile, the salary levels and the number of vacant positions in the workforce for the different disciplines in each Australian state and in New Zealand. Analysis of the data shows the changes to the workforce over the preceding 6 years and identifies shortfalls in the workforce.

21 CFR 361.1 - Radioactive drugs for certain research uses.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., hematology, endocrinology, radiation therapy, radiation physics, radiation biophysics, health physics, and... Section 361.1 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... on radiation health matters. Joint committees involving more than one medical institution which have...

Three- and two-dimensional simulations of counter-propagating shear experiments at high energy densities at the National Ignition Facility

DOE PAGES

Wang, Ping; Zhou, Ye; MacLaren, Stephan A.; ...

2015-11-06

Three- and two-dimensional numerical studies have been carried out to simulate recent counter-propagating shear flow experiments on the National Ignition Facility. A multi-physics three-dimensional, time-dependent radiation hydrodynamics simulation code is used. Using a Reynolds Averaging Navier-Stokes model, we show that the evolution of the mixing layer width obtained from the simulations agrees well with that measured from the experiments. A sensitivity study is conducted to illustrate a 3D geometrical effect that could confuse the measurement at late times, if the energy drives from the two ends of the shock tube are asymmetric. Implications for future experiments are discussed.

Synchrotron Radiation Workshop (SRW)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chubar, O.; Elleaume, P.

2013-03-01

"Synchrotron Radiation Workshop" (SRW) is a physical optics computer code for calculation of detailed characteristics of Synchrotron Radiation (SR) generated by relativistic electrons in magnetic fields of arbitrary configuration and for simulation of the radiation wavefront propagation through optical systems of beamlines. Frequency-domain near-field methods are used for the SR calculation, and the Fourier-optics based approach is generally used for the wavefront propagation simulation. The code enables both fully- and partially-coherent radiation propagation simulations in steady-state and in frequency-/time-dependent regimes. With these features, the code has already proven its utility for a large number of applications in infrared, UV, softmore » and hard X-ray spectral range, in such important areas as analysis of spectral performances of new synchrotron radiation sources, optimization of user beamlines, development of new optical elements, source and beamline diagnostics, and even complete simulation of SR based experiments. Besides the SR applications, the code can be efficiently used for various simulations involving conventional lasers and other sources. SRW versions interfaced to Python and to IGOR Pro (WaveMetrics), as well as cross-platform library with C API, are available.« less

Depth dose distribution study within a phantom torso after irradiation with a simulated Solar Particle Event at NSRL

NASA Astrophysics Data System (ADS)

Berger, Thomas; Matthiä, Daniel; Koerner, Christine; George, Kerry; Rhone, Jordan; Cucinotta, Francis A.; Reitz, Guenther

The adequate knowledge of the radiation environment and the doses incurred during a space mission is essential for estimating an astronaut's health risk. The space radiation environment is complex and variable, and exposures inside the spacecraft and the astronaut's body are com-pounded by the interactions of the primary particles with the atoms of the structural materials and with the body itself. Astronauts' radiation exposures are measured by means of personal dosimetry, but there remains substantial uncertainty associated with the computational extrap-olation of skin dose to organ dose, which can lead to over-or under-estimation of the health risk. Comparisons of models to data showed that the astronaut's Effective dose (E) can be pre-dicted to within about a +10In the research experiment "Depth dose distribution study within a phantom torso" at the NASA Space Radiation Laboratory (NSRL) at BNL, Brookhaven, USA the large 1972 SPE spectrum was simulated using seven different proton energies from 50 up to 450 MeV. A phantom torso constructed of natural bones and realistic distributions of human tissue equivalent materials, which is comparable to the torso of the MATROSHKA phantom currently on the ISS, was equipped with a comprehensive set of thermoluminescence detectors and human cells. The detectors are applied to assess the depth dose distribution and radiation transport codes (e.g. GEANT4) are used to assess the radiation field and interactions of the radiation field with the phantom torso. Lymphocyte cells are strategically embedded at selected locations at the skin and internal organs and are processed after irradiation to assess the effects of shielding on the yield of chromosome damage. The first focus of the pre-sented experiment is to correlate biological results with physical dosimetry measurements in the phantom torso. Further on the results of the passive dosimetry using the anthropomorphic phantoms represent the best tool to generate reliable to benchmark computational radiation transport models in a radiation field of interest. The presentation will give first results of the physical dose distribution, the comparison with GEANT4 computer simulations, based on a Voxel model of the phantom, and a comparison with the data from the chromosome aberration study. The help and support of Adam Russek and Michael Sivertz of the NASA Space Radiation Laboratory (NSRL), Brookhaven, USA during the setup and the irradiation of the phantom are highly appreciated. The Voxel model describing the human phantom used for the GEANT4 simulations was kindly provided by Monika Puchalska (CHALMERS, Gothenburg, Sweden).

A one-dimensional interactive soil-atmosphere model for testing formulations of surface hydrology

NASA Technical Reports Server (NTRS)

Koster, Randal D.; Eagleson, Peter S.

1990-01-01

A model representing a soil-atmosphere column in a GCM is developed for off-line testing of GCM soil hydrology parameterizations. Repeating three representative GCM sensitivity experiments with this one-dimensional model demonstrates that, to first order, the model reproduces a GCM's sensitivity to imposed changes in parameterization and therefore captures the essential physics of the GCM. The experiments also show that by allowing feedback between the soil and atmosphere, the model improves on off-line tests that rely on prescribed precipitation, radiation, and other surface forcing.

PHITS simulations of the Protective curtain experiment onboard the Service module of ISS: Comparison with absorbed doses measured with TLDs

NASA Astrophysics Data System (ADS)

Ploc, Ondřej; Sihver, Lembit; Kartashov, Dmitry; Shurshakov, Vyacheslav; Tolochek, Raisa

2013-12-01

"Protective curtain" was the physical experiment onboard the International Space Station (ISS) aimed on radiation measurement of the dose - reducing effect of the additional shielding made of hygienic water-soaked wipes and towels placed on the wall in the crew cabin of the Service module Zvezda. The measurements were performed with 12 detector packages composed of thermoluminescent detectors (TLDs) and plastic nuclear track detectors (PNTDs) placed at the Protective curtain, so that they created pairs of shielded and unshielded detectors.

Penetration of Solar Radiation into Solid Carbon Dioxide

NASA Astrophysics Data System (ADS)

Chinnery, H. E.; Hagermann, A.; Kaufmann, E.; Lewis, S. R.; Grady, M. M.

2017-09-01

Carbon dioxide ice exists naturally on the surface of Mars. This is a unique environment, with no Earth analogues, and so determining the properties of such a surface is important to further our understanding of the Martian environment. Laboratory experiments have determined the e-folding scale, or absorption scale length, for carbon dioxide slab ice, granular ice and snow. This is a universal measure of how transparent a material is to visible light, and so has implications for the radiative budget of carbon dioxide ice covered surfaces, as well as physical processes, such as the so-called spider formations in the cryptic region near the Martian south pole.

Gamma-Ray Detectors: From Homeland Security to the Cosmos (443rd Brookhaven Lecture)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolotnikov, Aleksey

2008-12-03

Many radiation detectors are first developed for homeland security or industrial applications. Scientists, however, are continuously realizing new roles that these detectors can play in high-energy physics and astrophysics experiments. On Wednesday, December 3, join presenter Aleksey Bolotnikov, a physicist in the Nonproliferation and National Security Department (NNSD) and a co-inventor of the cadmium-zinc-telluride Frisch-ring (CdZnTe) detector, for the 443rd Brookhaven Lecture, entitled Gamma-Ray Detectors: From Homeland Security to the Cosmos. In his lecture, Bolotnikov will highlight two primary radiation-detector technologies: CdZnTe detectors and fluid-Xeon (Xe) detectors.

Demonstration of Flying Mirror with Improved Efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pirozhkov, Alexander S.; Kando, Masaki; Fukuda, Yuji

2009-07-25

A strongly nonlinear wake wave driven by an intense laser pulse can act as a partially reflecting relativistic mirror (the flying mirror)[S. V. Bulanov, et al., Bulletin of the Lebedev Physics Institute, No. 6, 9 (1991); S. V. Bulanov, et al., Phys. Rev. Lett. 91, 085001 (2003)]. Upon reflection from such mirror, a counter-propagating optical-frequency laser pulse is directly converted into high-frequency radiation, with a frequency multiplication factor approx4gamma{sup 2}(the double Doppler effect). We present the results of recent experiment in which the photon number in the reflected radiation was at least several thousand times larger than in our proof-of-principlemore » experiment [M. Kando, et al., Phys. Rev. Lett. 99, 135001 (2007); A. S. Pirozhkov, et al., Phys. Plasmas 14, 123106 (2007)]. The flying mirror holds promise of generating intense coherent ultrashort XUV and x-ray pulses that inherit their temporal shape and polarization from the original optical-frequency (laser) pulses. Furthermore, the reflected radiation bears important information about the reflecting wake wave itself, which can be used for its diagnostics.« less

Evaluation of commercial ADC radiation tolerance for accelerator experiments

DOE PAGES

Chen, K.; Chen, H.; Kierstead, J.; ...

2015-08-17

Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detectormore » front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on radiation effects tests conducted on 17 commercially available analog to digital converters and extensive single event effect measurements on specific twelve and fourteen bit ADCs that presented high tolerance to ionizing dose. We discuss mitigation strategies for single event effects (SEE) for their use in the large hadron collider environment.« less

Survey of current situation in radiation belt modeling

NASA Technical Reports Server (NTRS)

Fung, Shing F.

2004-01-01

The study of Earth's radiation belts is one of the oldest subjects in space physics. Despite the tremendous progress made in the last four decades, we still lack a complete understanding of the radiation belts in terms of their configurations, dynamics, and detailed physical accounts of their sources and sinks. The static nature of early empirical trapped radiation models, for examples, the NASA AP-8 and AE-8 models, renders those models inappropriate for predicting short-term radiation belt behaviors associated with geomagnetic storms and substorms. Due to incomplete data coverage, these models are also inaccurate at low altitudes (e.g., <1000 km) where many robotic and human space flights occur. The availability of radiation data from modern space missions and advancement in physical modeling and data management techniques have now allowed the development of new empirical and physical radiation belt models. In this paper, we will review the status of modern radiation belt modeling. Published by Elsevier Ltd on behalf of COSPAR.

A Numerical Study of Cirrus Clouds. Part I: Model Description.

NASA Astrophysics Data System (ADS)

Liu, Hui-Chun; Wang, Pao K.; Schlesinger, Robert E.

2003-04-01

This article, the first of a two-part series, presents a detailed description of a two-dimensional numerical cloud model directed toward elucidating the physical processes governing the evolution of cirrus clouds. The two primary scientific purposes of this work are (a) to determine the evolution and maintenance mechanisms of cirrus clouds and try to explain why some cirrus can persist for a long time; and (b) to investigate the influence of certain physical factors such as radiation, ice crystal habit, latent heat, ventilation effects, and aggregation mechanisms on the evolution of cirrus. The second part will discuss sets of model experiments that were run to address objectives (a) and (b), respectively.As set forth in this paper, the aforementioned two-dimensional numerical model, which comprises the research tool for this study, is organized into three modules that embody dynamics, microphysics, and radiation. The dynamic module develops a set of equations to describe shallow moist convection, also parameterizing turbulence by using a 1.5-order closure scheme. The microphysical module uses a double-moment scheme to simulate the evolution of the size distribution of ice particles. Heterogeneous and homogeneous nucleation of haze particles are included, along with other ice crystal processes such as diffusional growth, sedimentation, and aggregation. The radiation module uses a two-stream radiative transfer scheme to determine the radiative fluxes and heating rates, while the cloud optical properties are determined by the modified anomalous diffraction theory (MADT) for ice particles. One of the main advantages of this cirrus model is its explicit formulation of the microphysical and radiative properties as functions of ice crystal habit.

Editorial

NASA Astrophysics Data System (ADS)

Bruzzi, Mara; Pace, Emanuele; Talamonti, Cinzia

2013-12-01

The 9th edition of the International Conference on Radiation Effects on Semiconductor Materials, Detectors and Devices (RESMDD), held in Florence, at Dipartimento di Fisica ed Astronomia on October 9-12, 2012, was aimed at discussing frontier research activities in several application fields as in nuclear and particle physics, astrophysics, medical and solid-state physics. Main topics discussed in this conference are tracking performance of heavily irradiated silicon detectors, developments required for the luminosity upgrade of the Large Hadron Collider (HL-LHC), radiation effects on semiconductor materials for medical (radiotherapy dosimeters, imaging devices), astrophysics (UV, X- and γ-ray detectors) and environmental applications, microscopic defect analysis of irradiated semiconductor materials and related radiation hardening technologies. On the first day the conference hosted a short course intended to introduce fundamentals in the development of semiconductor detectors for medical applications to graduate and PhD students, post-docs and young researchers, both engineers and physicists. Directors of the School were Prof. Marta Bucciolini of the University of Florence and INFN, Italy and Dr. Carlo Civinini, INFN Firenze, Italy. Emphasis was placed on the underlying physical principles, instrument design, factors affecting performance, and applications in both the clinical and preclinical applications. The School was attended by nearly 40 students/ young researchers. We warmly thank the Directors for organizing this interesting event and the professors and researchers who gave lessons, for sharing their experience and knowledge with the students.

Global Observations of Aerosols and Clouds from Combined Lidar and Passive Instruments to Improve Radiation Budget and Climate Studies

NASA Technical Reports Server (NTRS)

Winker, David M.

1999-01-01

Current uncertainties in the effects of clouds and aerosols on the Earth radiation budget limit our understanding of the climate system and the potential for global climate change. Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations - Climatologie Etendue des Nuages et des Aerosols (PICASSO-CENA) is a recently approved satellite mission within NASA's Earth System Science Pathfinder (ESSP) program which will address these uncertainties with a unique suite of active and passive instruments. The Lidar In-space Technology Experiment (LITE) demonstrated the potential benefits of space lidar for studies of clouds and aerosols. PICASSO-CENA builds on this experience with a payload consisting of a two-wavelength polarization-sensitive lidar, an oxygen A-band spectrometer (ABS), an imaging infrared radiometer (IIR), and a wide field camera (WFC). Data from these instruments will be used to measure the vertical distributions of aerosols and clouds in the atmosphere, as well as optical and physical properties of aerosols and clouds which influence the Earth radiation budget. PICASSO-CENA will be flown in formation with the PM satellite of the NASA Earth Observing System (EOS) to provide a comprehensive suite of coincident measurements of atmospheric state, aerosol and cloud optical properties, and radiative fluxes. The mission will address critical uncertainties iin the direct radiative forcing of aerosols and clouds as well as aerosol influences on cloud radiative properties and cloud-climate radiation feedbacks. PICASSO-CENA is planned for a three year mission, with a launch in early 2003. PICASSO-CENA is being developed within the framework of a collaboration between NASA and CNES.

On the contribution of circumferential resonance modes in acoustic radiation force experienced by cylindrical shells

NASA Astrophysics Data System (ADS)

Rajabi, Majid; Behzad, Mehdi

2014-10-01

A body insonified by a constant (time-varying) intensity sound field is known to experience a steady (oscillatory) force that is called the steady-state (dynamic) acoustic radiation force. Using the classical resonance scattering theorem (RST) which suggests the scattered field as a superposition of a resonance field and a background (non-resonance) component, we show that the radiation force acting on a cylindrical shell may be synthesized as a composition of three components: background part, resonance part and their interaction. The background component reveals the pure geometrical reflection effects and illustrates a regular behavior with respect to frequency, while the others demonstrate a singular behavior near the resonance frequencies. The results illustrate that the resonance effects associated to partial waves can be isolated by the subtraction of the background component from the total (steady-state or dynamic) radiation force function (i.e., residue component). In the case of steady-state radiation force, the components are exerted on the body as static forces. For the case of oscillatory amplitude excitation, the components are exerted at the modulation frequency with frequency-dependant phase shifts. The results demonstrate the dominant contribution of the non-resonance component of dynamic radiation force at high frequencies with respect to the residue component, which offers the potential application of ultrasound stimulated vibro-acoustic spectroscopy technique in low frequency resonance spectroscopy purposes. Furthermore, the proposed formulation may be useful essentially due to its intrinsic value in physical acoustics. In addition, it may unveil the contribution of resonance modes in the dynamic radiation force experienced by the cylindrical objects and its underlying physics.

High School Teachers' Understanding of Blackbody Radiation

ERIC Educational Resources Information Center

Balta, Nuri

2018-01-01

This study is a detailed look at the level of understanding of fundamental ideas about blackbody radiation (BBR) among physics teachers. The aim is to explore associations and ideas that teachers have regarding blackbody radiation: a concept used routinely in physics and chemistry, which is necessary to understand fundamentals of quantum physics.…

Medical Physics Panel Discussion

NASA Astrophysics Data System (ADS)

Guèye, Paul; Avery, Steven; Baird, Richard; Soares, Christopher; Amols, Howard; Tripuraneni, Prabhakar; Majewski, Stan; Weisenberger, Drew

2006-03-01

The panel discussion will explore opportunities and vistas in medical physics research and practice, medical imaging, teaching medical physics to undergraduates, and medical physics curricula as a recruiting tool for physics departments. Panel members consist of representatives from NSBP (Paul Guèye and Steven Avery), NIH/NIBIB (Richard Baird), NIST (Christopher Soares), AAPM (Howard Amols), ASTRO (Prabhakar Tripuraneni), and Jefferson Lab (Stan Majewski and Drew Weisenberger). Medical Physicists are part of Departments of Radiation Oncology at hospitals and medical centers. The field of medical physics includes radiation therapy physics, medical diagnostic and imaging physics, nuclear medicine physics, and medical radiation safety. It also ranges from basic researcher (at college institutions, industries, and laboratories) to applications in clinical environments.

Long term dose monitoring onboard the European Columbus module of the international space station (ISS) in the frame of DOSIS and DOSIS 3D project - results from the active instruments

NASA Astrophysics Data System (ADS)

Burmeister, Soenke; Berger, Thomas; Reitz, Guenther; Boehme, Matthias; Haumann, Lutz; Labrenz, Johannes

Besides the effects of the microgravity environment, and the psychological and psychosocial problems encountered in confined spaces, radiation is the main health detriment for long duration human space missions. The radiation environment encountered in space differs in nature from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones encountered on earth for occupational radiation workers. Accurate knowledge of the physical characteristics of the space radiation field in dependence on the solar activity, the orbital parameters and the different shielding configurations of the International Space Station ISS is therefore needed. For the investigation of the spatial and temporal distribution of the radiation field inside the European COLUMBUS module the experiment DOSIS (Dose Distribution Inside the ISS) under the lead of DLR has been launched on July 15 (th) 2009 with STS-127 to the ISS. The experimental package was transferred from the Space Shuttle into COLUMBUS on July 18 (th) . It consists of a combination of passive detector packages (PDP) distributed at 11 locations inside the European Columbus Laboratory and two active radiation detectors (Dosimetry Telescopes = DOSTELs) with a DDPU (DOSTEL Data and Power Unit) in a Nomex pouch (DOSIS MAIN BOX) mounted at a fixed location beneath the European Physiology Module rack (EPM) inside COLUMBUS. The active components of the DOSIS experiment were operational from July 18 (th) 2009 to June 16 (th) 2011. After refurbishment the hardware has been reactivated on May 15 (th) 2012 as active part of the DOSIS 3D experiment and provides continuous data since this activation. The presentation will focus on the latest results from the two DOSTEL instruments as absorbed dose, dose equivalent and the related LET spectra gathered within the DOSIS (2009 - 2011) and DOSIS 3D (2012 - 2014) experiment. The CAU contributions to DOSIS and DOSIS 3D are financially supported by BMWi under Grants 50WB0826, 50WB1026 and 50WB1232

Semi-Autonomous Rodent Habitat for Deep Space Exploration

NASA Technical Reports Server (NTRS)

Alwood, J. S.; Shirazi-Fard, Y.; Pletcher, D.; Globus, R.

2018-01-01

NASA has flown animals to space as part of trailblazing missions and to understand the biological responses to spaceflight. Mice traveled in the Lunar Module with the Apollo 17 astronauts and now mice are frequent research subjects in LEO on the ISS. The ISS rodent missions have focused on unravelling biological mechanisms, better understanding risks to astronaut health, and testing candidate countermeasures. A critical barrier for longer-duration animal missions is the need for humans-in-the-loop to perform animal husbandry and perform routine tasks during a mission. Using autonomous or telerobotic systems to alleviate some of these tasks would enable longer-duration missions to be performed at the Deep Space Gateway. Rodent missions performed using the Gateway as a platform could address a number of critical risks identified by the Human Research Program (HRP), as well as Space Biology Program questions identified by NRC Decadal Survey on Biological and Physical Sciences in Space, (2011). HRP risk areas of potentially greatest relevance that the Gateway rodent missions can address include those related to visual impairment (VIIP) and radiation risks to central nervous system, cardiovascular disease, as well as countermeasure testing. Space Biology focus areas addressed by the Gateway rodent missions include mechanisms and combinatorial effects of microgravity and radiation. The objectives of the work proposed here are to 1) develop capability for semi-autonomous rodent research in cis-lunar orbit, 2) conduct key experiments for testing countermeasures against low gravity and space radiation. The hardware and operations system developed will enable experiments at least one month in duration, which potentially could be extended to one year in duration. To gain novel insights into the health risks to crew of deep space travel (i.e., exposure to space radiation), results obtained from Gateway flight rodents can be compared to ground control groups and separate groups of mice exposed to simulated Galactic Cosmic Radiation (at the NASA Space Radiation Lab). Results can then be compared to identical experiments conducted on the ISS. Together results from Gateway, ground-based, and ISS rodent experiments will provide novel insight into the effects of space radiation.

Report from the Integrated Modeling Panel at the Workshop on the Science of Ignition on NIF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marinak, M; Lamb, D

2012-07-03

This section deals with multiphysics radiation hydrodynamics codes used to design and simulate targets in the ignition campaign. These topics encompass all the physical processes they model, and include consideration of any approximations necessary due to finite computer resources. The section focuses on what developments would have the highest impact on reducing uncertainties in modeling most relevant to experimental observations. It considers how the ICF codes should be employed in the ignition campaign. This includes a consideration of how the experiments can be best structured to test the physical models the codes employ.

Validating solar and solar-like star opacities

NASA Astrophysics Data System (ADS)

Le Pennec, Maëlle; TURCK-CHIEZE, Sylvaine; RIBEYRE, Xavier; DUCRET, Jean-Eric; BLANCARD, Christophe; COSSE, Philippe; MONDET, Guillaume; FAUSSURIER, Gérald

2015-08-01

The Sun is, as being our closest star, a privilege place to test and validate physics. However, the solar physics is not yet completely understood. Indeed, since the recent update of the solar composition, there are differences between solar models and seismic data, visible on the solar sound speed profile comparison. This well established large discrepancy (Turck-Chièze et al. 2001, 2004, 2011, Christensen-Dalsgaard et al. 2009, Basu et al. 2015) could be linked to radiative transfer issue.Two directions of investigation are proposed. One possibility to explain this gap could be that the Sun produces slightly more energy that it liberates on its surface (around 5%). This energy could be transformed into macroscopic motions in the radiative zone, which are not taken into account in the solar standard model. Another explanation could be that the calculations of energy transport are not correctly taken into account either on the calculation of the Rosseland mean values or in the treatment of the radiative acceleration. This could have an impact on the determination of the internal solar abundances.Unfortunately, there are very few experiments to validate these calculations (Bailey et al. 2014). That's why we are proposing an opacity experiment on a high-energy laser like LMJ, in the conditions of the radiative zone (T=[2 - 15.106 K] and ρ=[0.2 - 150 g/cm3]). The aim is to measure the opacity of the most important contributors to the global opacity in this solar area : iron, oxygen and silicon. We are exploiting in that purpose a technical approach called the Double Ablation Front. During the laser-plasma interaction, the plasma radiative effects allow to reach these high temperatures and densities at LTE and validate or not plasma effects and line widths. We will show the principle of this technique and the results of our simulations on several elements.In the mean time, we are also exploiting new opacity calculations thanks to the OPAS code (Blancard et al. 2012) at the conditions of the solar radiative zone. We will show the impact of these calculations on the solar model.

Ras Labs.-CASIS-ISS NL experiment for synthetic muscle: resistance to ionizing radiation

NASA Astrophysics Data System (ADS)

Rasmussen, Lenore; Sandberg, Eric; Albers, Leila N.; Rodriguez, Simone; Gentile, Charles A.; Meixler, Lewis D.; Ascione, George; Hitchner, Robert; Taylor, James; Hoffman, Dan; Cylinder, David; Moy, Leon; Mark, Patrick S.; Prillaman, Daniel L.; Nordarse, Robert; Menegus, Michael J.; Ratto, Jo Ann; Thellen, Christopher; Froio, Danielle; Furlong, Cosme; Razavi, Payam; Valenza, Logan; Hablani, Surbhi; Fuerst, Tyler; Gallucci, Sergio; Blocher, Whitney; Liffland, Stephanie

2016-04-01

In anticipation of deep space travel, new materials are being explored to assist and relieve humans in dangerous environments, such as high radiation, extreme temperature, and extreme pressure. Ras Labs Synthetic Muscle - electroactive polymers (EAPs) that contract and expand at low voltages - which mimic the unique gentle-yet-strong nature of human tissue, is a potential asset to manned space travel through protective gear and human assist robotics and for unmanned space exploration through deep space. Generation 3 Synthetic Muscle was proven to be resistant to extreme temperatures, and there were indications that these materials may also be radiation resistant. The purpose of the Ras Labs-CASIS-ISS Experiment is to test the radiation resistivity of the third and fourth generation of these EAPs, as well as to make them even more radiation resistant or radiation hardened. On Earth, exposure of the Generation 3 and Generation 4 EAPs to a Cs-137 radiation source for 47.8 hours with a total dose of 305.931 kRad of gamma radiation was performed at the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL) at Princeton University, followed by pH, peroxide, Shore Hardness Durometry, and electroactivity testing to determine the inherent radiation resistivity of these contractile EAPs and to determine whether the EAPs could be made even more radiation resistant through the application of appropriate additives and coatings. The on Earth preliminary tests determined that selected Ras Labs EAPs were not only inherently radiation resistant, but with the appropriate coatings and additives, could be made even more radiation resistant. Gforce testing to over 10 G's was performed at US Army's ARDEC Labs, with excellent results, in preparation for space flight to the International Space Station National Laboratory (ISS-NL). Selected samples of Generation 3 and Generation 4 Synthetic Muscle™, with various additives and coatings, were launched to the ISS-NL on April, 14 2015 on the SpaceX-6 payload, and will return to Earth in 2016. The most significant change from the on Earth radiation exposure was color change in the irradiated EAP samples, which in polymers can be indicative of accelerated aging. There was visible yellowing in the irradiated samples compared to the control samples, which were not irradiated and were clear and colorless. While the Synthetic Muscle Experiment is in orbit on the ISS-NL, photo events occur every 4 to 6 weeks to observe any changes, such as color, in the samples. The bulk of the testing will occur when these EAP samples return back to Earth, and will be compared to the duplicate experiment that remains on Earth (the control experiment). Smart electroactive polymer based materials and actuators promise to transform prostheses and robots, allowing for the treatment, reduction, and prevention of debilitating injury and fatalities, and to further our exploration by land, sea, air, and space.

Radiative neutron capture as a counting technique at pulsed spallation neutron sources: a review of current progress

NASA Astrophysics Data System (ADS)

Schooneveld, E. M.; Pietropaolo, A.; Andreani, C.; Perelli Cippo, E.; Rhodes, N. J.; Senesi, R.; Tardocchi, M.; Gorini, G.

2016-09-01

Neutron scattering techniques are attracting an increasing interest from scientists in various research fields, ranging from physics and chemistry to biology and archaeometry. The success of these neutron scattering applications is stimulated by the development of higher performance instrumentation. The development of new techniques and concepts, including radiative capture based neutron detection, is therefore a key issue to be addressed. Radiative capture based neutron detectors utilize the emission of prompt gamma rays after neutron absorption in a suitable isotope and the detection of those gammas by a photon counter. They can be used as simple counters in the thermal region and (simultaneously) as energy selector and counters for neutrons in the eV energy region. Several years of extensive development have made eV neutron spectrometers operating in the so-called resonance detector spectrometer (RDS) configuration outperform their conventional counterparts. In fact, the VESUVIO spectrometer, a flagship instrument at ISIS serving a continuous user programme for eV inelastic neutron spectroscopy measurements, is operating in the RDS configuration since 2007. In this review, we discuss the physical mechanism underlying the RDS configuration and the development of associated instrumentation. A few successful neutron scattering experiments that utilize the radiative capture counting techniques will be presented together with the potential of this technique for thermal neutron diffraction measurements. We also outline possible improvements and future perspectives for radiative capture based neutron detectors in neutron scattering application at pulsed neutron sources.

Summary of: radiation protection in dental X-ray surgeries--still rooms for improvement.

PubMed

Walker, Anne

2013-03-01

To illustrate the authors' experience in the provision of radiation protection adviser (RPA)/medical physics expert (MPE) services and critical examination/radiation quality assurance (QA) testing, to demonstrate any continuing variability of the compliance of X-ray sets with existing guidance and of compliance of dental practices with existing legislation. Data was collected from a series of critical examination and routine three-yearly radiation QA tests on 915 intra-oral X-ray sets and 124 panoramic sets. Data are the result of direct measurements on the sets, made using a traceably calibrated Unfors Xi meter. The testing covered the measurement of peak kilovoltage (kVp); filtration; timer accuracy and consistency; X-ray beam size; and radiation output, measured as the entrance surface dose in milliGray (mGy) for intra-oral sets and dose-area product (DAP), measured in mGy.cm(2) for panoramic sets. Physical checks, including mechanical stability, were also included as part of the testing process. The Health and Safety Executive has expressed concern about the poor standards of compliance with the regulations during inspections at dental practices. Thirty-five percent of intra-oral sets exceeded the UK adult diagnostic reference level on at least one setting, as did 61% of those with child dose settings. There is a clear advantage of digital radiography and rectangular collimation in dose terms, with the mean dose from digital sets 59% that of film-based sets and a rectangular collimator 76% that of circular collimators. The data shows the unrealised potential for dose saving in many digital sets and also marked differences in dose between sets. Provision of radiation protection advice to over 150 general dental practitioners raised a number of issues on the design of surgeries with X-ray equipment and critical examination testing. There is also considerable variation in advice given on the need (or lack of need) for room shielding. Where no radiation protection adviser (RPA) or medical physics expert (MPE) appointment has been made, there is often a very low level of compliance with legislative requirements. The active involvement of an RPA/MPE and continuing education on radiation protection issues has the potential to reduce radiation doses significantly further in many dental practices.

Radiation protection in dental X-ray surgeries--still rooms for improvement.

PubMed

Hart, G; Dugdale, M

2013-03-01

To illustrate the authors' experience in the provision of radiation protection adviser (RPA)/medical physics expert (MPE) services and critical examination/radiation quality assurance (QA) testing, to demonstrate any continuing variability of the compliance of X-ray sets with existing guidance and of compliance of dental practices with existing legislation. Data was collected from a series of critical examination and routine three-yearly radiation QA tests on 915 intra-oral X-ray sets and 124 panoramic sets. Data are the result of direct measurements on the sets, made using a traceably calibrated Unfors Xi meter. The testing covered the measurement of peak kilovoltage (kVp); filtration; timer accuracy and consistency; X-ray beam size; and radiation output, measured as the entrance surface dose in milliGray (mGy) for intra-oral sets and dose-area product (DAP), measured in mGy.cm(2) for panoramic sets. Physical checks, including mechanical stability, were also included as part of the testing process. The Health and Safety Executive has expressed concern about the poor standards of compliance with the regulations during inspections at dental practices. Thirty-five percent of intra-oral sets exceeded the UK adult diagnostic reference level on at least one setting, as did 61% of those with child dose settings. There is a clear advantage of digital radiography and rectangular collimation in dose terms, with the mean dose from digital sets 59% that of film-based sets and a rectangular collimator 76% that of circular collimators. The data shows the unrealised potential for dose saving in many digital sets and also marked differences in dose between sets. Provision of radiation protection advice to over 150 general dental practitioners raised a number of issues on the design of surgeries with X-ray equipment and critical examination testing. There is also considerable variation in advice given on the need (or lack of need) for room shielding. Where no radiation protection adviser (RPA) or medical physics expert (MPE) appointment has been made, there is often a very low level of compliance with legislative requirements. The active involvement of an RPA/MPE and continuing education on radiation protection issues has the potential to reduce radiation doses significantly further in many dental practices.

The physics of volume rendering

NASA Astrophysics Data System (ADS)

Peters, Thomas

2014-11-01

Radiation transfer is an important topic in several physical disciplines, probably most prominently in astrophysics. Computer scientists use radiation transfer, among other things, for the visualization of complex data sets with direct volume rendering. In this article, I point out the connection between physical radiation transfer and volume rendering, and I describe an implementation of direct volume rendering in the astrophysical radiation transfer code RADMC-3D. I show examples for the use of this module on analytical models and simulation data.

Evaluation of the biological effects of police radar RAMER 7F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rotkovska, D.; Kautska, J.; Bartonickova, A.

1993-06-01

This paper presents results of experiments on the effects of electromagnetic radiation in the millimeter range (frequency 34.0 [+-] 0.1 GHz, power density 20 [mu]W/cm[sup 2]) emitted by a police radar device. Considering the physical properties of the radiation in millimeter range (skin effects), the experiments were carried out on hairless mice. The main physiological parameters tested were body mass, body temperature, peripheral blood, and mass and cellularity of several important organs. Critical organs, the skin, and cornea were examined by electron microscopy. Differentiation ability of hematopoietic cells, progenitors of granulocytes and macrophages, and DNA synthesis in the cornea weremore » compared in irradiated and nonirradiated animals. None of the parameters tested was affected to an extent that would indicate the start of a pathological process or the risk of damage to genetic material.« less

User's Guide for ERB 7 Matrix. Volume 1: Experiment Description and Quality Control Report for Year 1

NASA Technical Reports Server (NTRS)

Tighe, R. J.; Shen, M. Y. H.

1984-01-01

The Nimbus 7 ERB MATRIX Tape is a computer program in which radiances and irradiances are converted into fluxes which are used to compute the basic scientific output parameters, emitted flux, albedo, and net radiation. They are spatially averaged and presented as time averages over one-day, six-day, and monthly periods. MATRIX data for the period November 16, 1978 through October 31, 1979 are presented. Described are the Earth Radiation Budget experiment, the Science Quality Control Report, Items checked by the MATRIX Science Quality Control Program, and Science Quality Control Data Analysis Report. Additional material from the detailed scientific quality control of the tapes which may be very useful to a user of the MATRIX tapes is included. Known errors and data problems and some suggestions on how to use the data for further climatologic and atmospheric physics studies are also discussed.

Twenty years of space radiation physics at the BNL AGS and NASA Space Radiation Laboratory.

PubMed

Miller, J; Zeitlin, C

2016-06-01

Highly ionizing atomic nuclei HZE in the GCR will be a significant source of radiation exposure for humans on extended missions outside low Earth orbit. Accelerators such as the LBNL Bevalac and the BNL AGS, designed decades ago for fundamental nuclear and particle physics research, subsequently found use as sources of GCR-like particles for ground-based physics and biology research relevant to space flight. The NASA Space Radiation Laboratory at BNL was constructed specifically for space radiation research. Here we review some of the space-related physics results obtained over the first 20 years of NASA-sponsored research at Brookhaven. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Mental Health Consequences and Social Issues After the Fukushima Disaster.

PubMed

Maeda, Masaharu; Oe, Misari

2017-03-01

The Great East Japan Earthquake and subsequent nuclear power plant accident caused multidimensional and long-term effects on the mental health condition of people living in Fukushima. In this article, focusing on the influence of the nuclear disaster, we present an overview of studies regarding the psychosocial consequences of people in Fukushima. Studies revealed that the experiences of the explosions at the plant as well as the tsunami are deeply embedded in their memory, leading to posttraumatic responses. Chronic physical diseases, worries about livelihood, lost jobs, lost social ties, and concerns about compensation were also associated with posttraumatic responses. Furthermore, the radioactive fallout brought chronic anxiety regarding physical risks of radiation exposure to people, especially young mothers. People often have different opinions about the radiation risk and their own future plans, resulting in a reduction in the resilience that communities and families had before the disaster. In addition, such weakened community resilience may produce a significant increase in disaster-related suicide in Fukushima. Specific social issues, such as "radiation stigma" among the public and self-stigma among evacuees, that are never seen with other natural disasters also increased in Fukushima.

Physics prospects of the Jinping neutrino experiment

NASA Astrophysics Data System (ADS)

Beacom, John F.; Chen, Shaomin; Cheng, Jianping; Doustimotlagh, Sayed N.; Gao, Yuanning; Gong, Guanghua; Gong, Hui; Guo, Lei; Han, Ran; He, Hong-Jian; Huang, Xingtao; Li, Jianmin; Li, Jin; Li, Mohan; Li, Xueqian; Liao, Wei; Lin, Guey-Lin; Liu, Zuowei; McDonough, William; Šrámek, Ondřej; Tang, Jian; Wan, Linyan; Wang, Yuanqing; Wang, Zhe; Wang, Zongyi; Wei, Hanyu; Xi, Yufei; Xu, Ye; Xu, Xun-Jie; Yang, Zhenwei; Yao, Chunfa; Yeh, Minfang; Yue, Qian; Zhang, Liming; Zhang, Yang; Zhao, Zhihong; Zheng, Yangheng; Zhou, Xiang; Zhu, Xianglei; Zuber, Kai

2017-02-01

The China Jinping Underground Laboratory (CJPL), which has the lowest cosmic-ray muon flux and the lowest reactor neutrino flux of any laboratory, is ideal to carry out low-energy neutrino experiments. With two detectors and a total fiducial mass of 2000 tons for solar neutrino physics (equivalently, 3000 tons for geo-neutrino and supernova neutrino physics), the Jinping neutrino experiment will have the potential to identify the neutrinos from the CNO fusion cycles of the Sun, to cover the transition phase for the solar neutrino oscillation from vacuum to matter mixing, and to measure the geo-neutrino flux, including the Th/U ratio. These goals can be fulfilled with mature existing techniques. Efforts on increasing the target mass with multi-modular neutrino detectors and on developing the slow liquid scintillator will increase the Jinping discovery potential in the study of solar neutrinos, geo-neutrinos, supernova neutrinos, and dark matter. Supported by the National Natural Science Foundation of China (11235006, 11475093, 11135009, 11375065, 11505301, and 11620101004), the Tsinghua University Initiative Scientific Research Program (20121088035, 20131089288, and 20151080432), the Key Laboratory of Particle & Radiation Imaging (Tsinghua University), the CAS Center for Excellence in Particle Physics (CCEPP), U.S. National Science Foundation Grant PHY-1404311 (Beacom), and U.S. Department of Energy under contract DE-AC02-98CH10886 (Yeh).

Nuclear physics research at the University of Richmond. Progress report, November 1, 1994--October 31, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vineyard, M.F.; Gilfoyle, G.P.; Major, R.W.

Summarized in this report is the progress achieved during the period from November 1, 1994 to October 31, 1995. The experimental work described in this report is in electromagnetic and heavy-ion nuclear physics. The effort in electromagnetic nuclear physics is in preparation for the research program at the Continuous Electron Beam Accelerator Facility (CEBAF) and is focused on the construction and use of the CEBAF Large Acceptance Spectrometer (CLAS). The heavy-ion experiments were performed at the Argonne National Laboratory ATLAS facility and SUNY, Stony Brook. The physics interests driving these efforts at CEBAF are in the study of the structure,more » interactions, and nuclear-medium modifications of mesons and baryons. This year, an extension of the experiment to measure the magnetic form factor of the neutron was approved by the CEBAF Program Advisory Committee Nine (PAC9) for beam at 6 GeV. The authors also submitted updates to PAC9 on the experiments to measure inclusive {eta} photoproduction in nuclei and electroproduction of the {Lambda}, {Lambda}*(1520), and f{sub 0}(975). In addition to these experiments, the authors collaborated on a proposal to measure rare radiative decays of the {phi} meson which was also approved by PAC9. Their contributions to the construction of the CLAS include the development of the drift-chamber gas system, drift-chamber software, and controls software. Major has been leading the effort in the construction of the gas system. In the last year, the Hall B gas shed was constructed and the installation of the gas system components built at the University of Richmond has begun. Over the last six years, the efforts in low-energy heavy-ion physics have decreased due to the change in focus to electromagnetic nuclear physics at CEBAF. Most of the heavy-ion work is completed and there are now new experiments planned. Included in this report are two papers resulting from collaborations on heavy-ion experiments.« less

Frequency-independent approach to calculate physical optics radiations with the quadratic concave phase variations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Yu Mao, E-mail: yumaowu@fudan.edu.cn; Teng, Si Jia, E-mail: sjteng12@fudan.edu.cn

In this work, we develop the numerical steepest descent path (NSDP) method to calculate the physical optics (PO) radiations with the quadratic concave phase variations. With the surface integral equation method, the physical optics (PO) scattered fields are formulated and further reduced to the surface integrals. The high frequency physical critical points contributions, including the stationary phase points, the boundary resonance points and the vertex points are comprehensively studied via the proposed NSDP method. The key contributions of this work are twofold. One is that together with the PO integrals taking the quadratic parabolic and hyperbolic phase terms, this workmore » makes the NSDP theory be complete for treating the PO integrals with quadratic phase variations. Another is that, in order to illustrate the transition effect of the high frequency physical critical points, in this work, we consider and further extend the NSDP method to calculate the PO integrals with the coalescence of the high frequency critical points. Numerical results for the highly oscillatory PO integral with the coalescence of the critical points are given to verify the efficiency of the proposed NSDP method. The NSDP method could achieve the frequency independent computational workload and error controllable accuracy in all the numerical experiments, especially for the case of the coalescence of the high frequency critical points.« less

Design Considerations of a Virtual Laboratory for Advanced X-ray Sources

NASA Astrophysics Data System (ADS)

Luginsland, J. W.; Frese, M. H.; Frese, S. D.; Watrous, J. J.; Heileman, G. L.

2004-11-01

The field of scientific computation has greatly advanced in the last few years, resulting in the ability to perform complex computer simulations that can predict the performance of real-world experiments in a number of fields of study. Among the forces driving this new computational capability is the advent of parallel algorithms, allowing calculations in three-dimensional space with realistic time scales. Electromagnetic radiation sources driven by high-voltage, high-current electron beams offer an area to further push the state-of-the-art in high fidelity, first-principles simulation tools. The physics of these x-ray sources combine kinetic plasma physics (electron beams) with dense fluid-like plasma physics (anode plasmas) and x-ray generation (bremsstrahlung). There are a number of mature techniques and software packages for dealing with the individual aspects of these sources, such as Particle-In-Cell (PIC), Magneto-Hydrodynamics (MHD), and radiation transport codes. The current effort is focused on developing an object-oriented software environment using the Rational© Unified Process and the Unified Modeling Language (UML) to provide a framework where multiple 3D parallel physics packages, such as a PIC code (ICEPIC), a MHD code (MACH), and a x-ray transport code (ITS) can co-exist in a system-of-systems approach to modeling advanced x-ray sources. Initial software design and assessments of the various physics algorithms' fidelity will be presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caillet, V; Colvill, E; Royal North Shore Hospital, Sydney, NSW

Purpose: The objective of this study was to investigate the dosimetric benefits of multi-leaf collimator (MLC) tracking for lung SABR treatments in end-to-end clinically realistic planning and delivery scenarios. Methods: The clinical benefits of MLC tracking were assessed using previously delivered treatment plans and physical experiments. The 10 most recent single lesion lung SABR patients were re-planned following a 4D-GTV-based real-time adaptive protocol (PTV defined as the end-of-exhalation GTV plus 5.0 mm margins). The plans were delivered on a Trilogy Varian linac. Electromagnetic transponders (Calypso, Varian Medical Systems, USA) were embedded into a programmable moving phantom (HexaMotion platform) tracked withmore » the Varian Calypso system. For each physical experiment, the MLC positions were collected and used as input for dose reconstruction. For both planned and physical experiments, the OAR dose metrics from the conventional and real-time adaptive SABR plans (Mean Lung Dose (MLD), V20 for lung, and near-maximum dose (D2%) for spine and heart) were statistically compared. The Wilcoxon test was used to compare plan and physical experiment dose metrics. Results: While maintaining target coverage, percentage reductions in dose metrics to the OARs were observed for both planned and physical experiments. Comparing the two plans showed MLD percentage reduction (MLDr) of 25.4% (absolute differences of 1.41 Gy) and 28.9% (1.29%) for the V20r. D2% percentage reduction for spine and heart were respectively 27.9% (0.3 Gy) and 20.2% (0.3 Gy). For the physical experiments, MLDr was 23.9% (1.3 Gy), and V20r 37.4% (1.6%). D2% reduction for spine and heart were respectively 27.3% (0.3 Gy) and 19.6% (0.3 Gy). For both plans and physical experiments, significant OAR dose differences (p<0.05) were found between the conventional SABR and real-time adaptive plans. Conclusion: Application of MLC tracking for lung SABR patients has the potential to reduce the dose to OARs during radiation therapy.« less

Editorial

NASA Astrophysics Data System (ADS)

Musilek, L.; Dunn, W. L.

2017-08-01

The selected proceedings of the 13th International Symposium on Radiation Physics (ISRP-13) are presented here across a broad range of important topics including: Fundamental processes in radiation physics, Theoretical investigations, New radiation sources, techniques & detectors, Absorption and fluorescence spectroscopy (XAFS, XANES, XRF Spectroscopy, Raman, Infrared …), Applications of radiation in material science, nano-science & nanotechnology, Applications of radiation in biology & medical science, Applications of radiation in space, earth, energy & environmental sciences, Applications of radiation in cultural heritage & art and Applications of radiation in industry. In total, 48 papers have been accepted for these proceedings.

KSC-02pd1657

NASA Image and Video Library

2002-10-26

KENNEDY SPACE CENTER, FLA. -- A container with the Solar Radiation and Climate Experiment (SORCE) spacecraft inside is offloaded at the Multi-Purpose Processing Facility at KSC. The spacecraft will undergo final processing for launch. SORCE is equipped with four instruments that will measure variations in solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. The SORCE project is managed by NASA's Goddard Space Flight Center. The instruments on the SORCE spacecraft are built by the Laboratory for Atmospheric and Space Physics (LASP). Launch of SORCE aboard a Pegasus XL rocket is scheduled for mid-December 2002. Launch site is Cape Canaveral Air Force Station, Fla.

KSC-02pd1659

NASA Image and Video Library

2002-10-28

KENNEDY SPACE CENTER, FLA. - In the Multi-Purpose Processing Facility at KSC, workers unpack the Solar Radiation and Climate Experiment (SORCE) spacecraft. SORCE arrived at Kennedy Space Center Oct. 26 to begin final processing. SORCE is equipped with four instruments that will measure variations in solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. The SORCE project is managed by NASA's Goddard Space Flight Center. The instruments on the SORCE spacecraft are built by the Laboratory for Atmospheric and Space Physics (LASP). Launch of SORCE aboard a Pegasus XL rocket is scheduled for mid-December 2002. Launch site is Cape Canaveral Air Force Station, Fla.

KSC-02pd1662

NASA Image and Video Library

2002-10-28

KENNEDY SPACE CENTER, FLA. -- Workers in the Multi-Purpose Processing Facility at KSC help guide the Solar Radiation and Climate Experiment (SORCE) spacecraft onto a workstand. SORCE arrived at Kennedy Space Center Oct. 26 to begin final processing. SORCE is equipped with four instruments that will measure variations in solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. The SORCE project is managed by NASA's Goddard Space Flight Center. The instruments on the SORCE spacecraft are built by the Laboratory for Atmospheric and Space Physics (LASP). Launch of SORCE aboard a Pegasus XL rocket is scheduled for mid-December 2002. Launch site is Cape Canaveral Air Force Station, Fla.

KSC-02pd1665

NASA Image and Video Library

2002-10-28

KENNEDY SPACE CENTER, FLA. - Workers in the Multi-Purpose Processing Facility at KSC look over the Solar Radiation and Climate Experiment (SORCE) spacecraft. SORCE arrived at Kennedy Space Center Oct. 26 to begin final processing. SORCE is equipped with four instruments that will measure variations in solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. The SORCE project is managed by NASA's Goddard Space Flight Center. The instruments on the SORCE spacecraft are built by the Laboratory for Atmospheric and Space Physics (LASP). Launch of SORCE aboard a Pegasus XL rocket is scheduled for mid-December 2002. Launch site is Cape Canaveral Air Force Station, Fla.

Cavity Optomechanics: Coherent Coupling of Light and Mechanical Oscillators

NASA Astrophysics Data System (ADS)

Kippenberg, Tobias J.

2012-06-01

The mutual coupling of optical and mechanical degrees of freedom via radiation pressure has been a subject of interest in the context of quantum limited displacements measurements for Gravity Wave Detection for many decades, however light forces have remained experimentally unexplored in such systems. Recent advances in nano- and micro-mechanical oscillators have for the first time allowed the observation of radiation pressure phenomena in an experimental setting and constitute the expanding research field of cavity optomechanics [1]. These advances have allowed achieving to enter the quantum regime of mechanical systems, which are now becoming a third quantum technology after atoms, ions and molecules in a first and electronic circuits in a second wave. In this talk I will review these advances. Using on-chip micro-cavities that combine both optical and mechanical degrees of freedom in one and the same device [2], radiation pressure back-action of photons is shown to lead to effective cooling [3-6]) of the mechanical oscillator mode using dynamical backaction, which has been predicted by Braginsky as early as 1969 [4]. This back-action cooling exhibits many close analogies to atomic laser cooling. With this novel technique the quantum mechanical ground state of a micromechanical oscillator has been prepared with high probability using both microwave and optical fields. In our research this is reached using cryogenic precooling to ca. 800 mK in conjunction with laser cooling, allowing cooling of micromechanical oscillator to only motional 1.7 quanta, implying that the mechanical oscillator spends about 40% of its time in the quantum ground state. Moreover it is possible in this regime to observe quantum coherent coupling in which the mechanical and optical mode hybridize and the coupling rate exceeds the mechanical and optical decoherence rate [7]. This accomplishment enables a range of quantum optical experiments, including state transfer from light to mechanics using the phenomenon of optomechanically induced transparency [8]. From a broader perspective the described experiments that exploit optomechanical coupling are motivated both by the effort to realize quantum measurement schemes on mechanical systems in an experimental setting as well as to explore the behavior of nanomechanical systems at low temperatures.[0pt] [1] T. J. Kippenberg, K. J. Vahala, Cavity Optomechanics: Backaction at the mesoscale. Science 321, 1172 (2008, 2008); [2] T. J. Kippenberg, H. Rokhsari, T. Carmon, A. Scherer, K. J. Vahala, Analysis of Radiation-Pressure Induced Mechanical Oscillation of an Optical Microcavity. Physical Review Letters 95, 033901 (2005); [3] V. B. Braginsky, S. P. Vyatchanin, Low quantum noise tranquilizer for Fabry-Perot interferometer. Physics Letters A 293, 228 (Feb 4, 2002); [4] V. B. Braginsky, Measurement of Weak Forces in Physics Experiments. (University of Chicago Press, Chicago, 1977); [5] A. Schliesser, P. Del'Haye, N. Nooshi, K. J. Vahala, T. J. Kippenberg, Radiation pressure cooling of a micromechanical oscillator using dynamical backaction. Physical Review Letters 97, 243905 (Dec 15, 2006); [6] A. Schliesser, R. Riviere, G. Anetsberger, O. Arcizet, T. J. Kippenberg, Resolved-sideband cooling of a micromechanical oscillator. Nature Physics 4, 415 (May, 2008); [7] E. Verhagen, S. Deleglise, S. Weis, A. Schliesser, T.J. Kippenberg, Nature (in press, 2012); [8] S. Weis et al., Optomechanically Induced Transparency. Science 330, 1520 (Dec, 2010).

Transversality of Electromagnetic Waves in the Calculus--Based Introductory Physics Course

NASA Astrophysics Data System (ADS)

Burko, Lior M.

2009-05-01

Introductory calculus--based physics textbooks state that electromagnetic waves are transverse and list many of their properties, but most such textbooks do not bring forth arguments why this is so. Both physical and theoretical arguments are at a level appropriate for students of courses based on such books, and could be readily used by instructors of such courses. Here, we discuss two physical arguments (based on polarization experiments and on lack of monopole electromagnetic radiation), and the full argument for the transversality of (plane) electromagnetic waves based on the integral Maxwell equations. We also show, at a level appropriate for the introductory course, why the electric and magnetic fields in a wave are in phase and the relation of their magnitudes. We have successfully integrated this approach in the calculus--based introductory physics course at the University of Alabama in Huntsville.

Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter (in Chinese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Chuyu

2012-12-31

Beam diagnostics is an essential constituent of any accelerator, so that it is named as "organs of sense" or "eyes of the accelerator." Beam diagnostics is a rich field. A great variety of physical effects or physical principles are made use of in this field. Some devices are based on electro-magnetic influence by moving charges, such as faraday cups, beam transformers, pick-ups; Some are related to Coulomb interaction of charged particles with matter, such as scintillators, viewing screens, ionization chambers; Nuclear or elementary particle physics interactions happen in some other devices, like beam loss monitors, polarimeters, luminosity monitors; Some measuremore » photons emitted by moving charges, such as transition radiation, synchrotron radiation monitors and diffraction radiation-which is the topic of the first part of this thesis; Also, some make use of interaction of particles with photons, such as laser wire and Compton polarimeters-which is the second part of my thesis. Diagnostics let us perceive what properties a beam has and how it behaves in a machine, give us guideline for commissioning, controlling the machine and indispensable parameters vital to physics experiments. In the next two decades, the research highlight will be colliders (TESLA, CLIC, JLC) and fourth-generation light sources (TESLA FEL, LCLS, Spring 8 FEL) based on linear accelerator. These machines require a new generation of accelerator with smaller beam, better stability and greater efficiency. Compared with those existing linear accelerators, the performance of next generation linear accelerator will be doubled in all aspects, such as 10 times smaller horizontal beam size, more than 10 times smaller vertical beam size and a few or more times higher peak power. Furthermore, some special positions in the accelerator have even more stringent requirements, such as the interaction point of colliders and wigglor of free electron lasers. Higher performance of these accelerators increases the difficulty of diagnostics. For most cases, intercepting measurements are no longer acceptable, and nonintercepting method like synchrotron radiation monitor can not be applied to linear accelerators. The development of accelerator technology asks for simutanous diagnostics innovations, to expand the performance of diagnostic tools to meet the requirements of the next generation accelerators. Diffraction radiation and inverse Compton scattering are two of the most promising techniques, their nonintercepting nature avoids perturbance to the beam and damage to the instrumentation. This thesis is divided into two parts, beam size measurement by optical diffraction radiation and Laser system for Compton polarimeter. Diffraction radiation, produced by the interaction between the electric field of charged particles and the target, is related to transition radiation. Even though the theory of diffraction radiation has been discussed since 1960s, there are only a few experimental studies in recent years. The successful beam size measurement by optical diffraction radiation at CEBAF machine is a milestone: First of all, we have successfully demonstrated diffraction radiation as an effective nonintercepting diagnostics; Secondly, the simple linear relationship between the diffraction radiation image size and the actual beam size improves the reliability of ODR measurements; And, we measured the polarized components of diffraction radiation for the first time and I analyzed the contribution from edge radiation to diffraction radiation.« less

Depth Dose Distribution Study within a Phantom Torso after Irradiation with a Simulated Solar Particle Event at NSRL

NASA Technical Reports Server (NTRS)

Berger, Thomas; Matthiae, Daniel; Koerner, Christine; George, Kerry; Rhone, Jordan; Cucinotta, Francis; Reitz, Guenther

2010-01-01

The adequate knowledge of the radiation environment and the doses incurred during a space mission is essential for estimating an astronaut's health risk. The space radiation environment is complex and variable, and exposures inside the spacecraft and the astronaut's body are compounded by the interactions of the primary particles with the atoms of the structural materials and with the body itself Astronauts' radiation exposures are measured by means of personal dosimetry, but there remains substantial uncertainty associated with the computational extrapolation of skin dose to organ dose, which can lead to over- or underestimation of the health risk. Comparisons of models to data showed that the astronaut's Effective dose (E) can be predicted to within about a +10% accuracy using space radiation transport models for galactic cosmic rays (GCR) and trapped radiation behind shielding. However for solar particle event (SPE) with steep energy spectra and for extra-vehicular activities on the surface of the moon where only tissue shielding is present, transport models predict that there are large differences in model assumptions in projecting organ doses. Therefore experimental verification of SPE induced organ doses may be crucial for the design of lunar missions. In the research experiment "Depth dose distribution study within a phantom torso" at the NASA Space Radiation Laboratory (NSRL) at BNL, Brookhaven, USA the large 1972 SPE spectrum was simulated using seven different proton energies from 50 up to 450 MeV. A phantom torso constructed of natural bones and realistic distributions of human tissue equivalent materials, which is comparable to the torso of the MATROSHKA phantom currently on the ISS, was equipped with a comprehensive set of thermoluminescence detectors and human cells. The detectors are applied to assess the depth dose distribution and radiation transport codes (e.g. GEANT4) are used to assess the radiation field and interactions of the radiation field with the phantom torso. Lymphocyte cells are strategically embedded at selected locations at the skin and internal organs and are processed after irradiation to assess the effects of shielding on the yield of chromosome damage. The initial focus of the present experiment is to correlate biological results with physical dosimetry measurements in the phantom torso. Further on, the results of the passive dosimetry within the anthropomorphic phantoms represent the best tool to generate reliable data to benchmark computational radiation transport models in a radiation field of interest. The presentation will give first results of the physical dose distribution, the comparison with GEANT4 computer simulations based on a Voxel model of the phantom, and a comparison with the data from the chromosome aberration study.

WE-D-303-01: Development and Application of Digital Human Phantoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segars, P.

2015-06-15

Modern medical physics deals with complex problems such as 4D radiation therapy and imaging quality optimization. Such problems involve a large number of radiological parameters, and anatomical and physiological breathing patterns. A major challenge is how to develop, test, evaluate and compare various new imaging and treatment techniques, which often involves testing over a large range of radiological parameters as well as varying patient anatomies and motions. It would be extremely challenging, if not impossible, both ethically and practically, to test every combination of parameters and every task on every type of patient under clinical conditions. Computer-based simulation using computationalmore » phantoms offers a practical technique with which to evaluate, optimize, and compare imaging technologies and methods. Within simulation, the computerized phantom provides a virtual model of the patient’s anatomy and physiology. Imaging data can be generated from it as if it was a live patient using accurate models of the physics of the imaging and treatment process. With sophisticated simulation algorithms, it is possible to perform virtual experiments entirely on the computer. By serving as virtual patients, computational phantoms hold great promise in solving some of the most complex problems in modern medical physics. In this proposed symposium, we will present the history and recent developments of computational phantom models, share experiences in their application to advanced imaging and radiation applications, and discuss their promises and limitations. Learning Objectives: Understand the need and requirements of computational phantoms in medical physics research Discuss the developments and applications of computational phantoms Know the promises and limitations of computational phantoms in solving complex problems.« less

Magnetospheric and solar physics observations with the PAMELA experiment

NASA Astrophysics Data System (ADS)

Casolino, M.; Adriani, O.; Ambriola, M.; Barbarino, G. C.; Basili, A.; Bazilevskaja, G. A.; Boezio, M.; Bogomolov, E. A.; Bonechi, L.; Bongi, M.; Bonvicini, V.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Castellini, G.; de Marzo, C.; de Pascale, M. P.; de Rosa, G.; de Simone, N.; di Felice, V.; Fedele, D.; Galper, A. M.; Hofverberg, P.; Koldashov, S. V.; Krutkov, S. Yu.; Kvashnin, A. N.; Lundquist, J.; Maksumov, O.; Malvezzi, V.; Marcelli, L.; Menn, W.; Mikhailov, V. V.; Minori, M.; Misin, S.; Mocchiutti, E.; Morselli, A.; Nikonov, N. N.; Orsi, S.; Osteria, G.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Runtso, M. F.; Russo, S.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Yu. I.; Taddei, E.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Zverev, V. G.

2008-04-01

PAMELA is a satellite-borne experiment designed to make long duration measurements of the cosmic radiation in Low Earth Orbit. It is devoted to the detection of the cosmic-ray spectra in the 100 MeV 300 GeV range with primary scientific goal the measurement of antiproton and positron spectra over the largest energy range ever achieved. Other tasks include the search for antinuclei with unprecedented sensitivity and the measurement of the light nuclear component of cosmic rays. In addition, PAMELA can investigate phenomena connected with solar and Earth physics. The apparatus consists of: a Time of Flight system, a magnetic spectrometer, an electromagnetic imaging calorimeter, a shower tail catcher scintillator, a neutron detector and an anticoincidence system. In this work we present some measurements of galactic, secondary and trapped particles performed in the first months of operation.

Simulating Extraterrestrial Ices in the Laboratory

NASA Astrophysics Data System (ADS)

Berisford, D. F.; Carey, E. M.; Hand, K. P.; Choukroun, M.

2017-12-01

Several ongoing experiments at JPL attempt to simulate the ice environment for various regimes associated with icy moons. The Europa Penitent Ice Experiment (EPIX) simulates the surface environment of an icy moon, to investigate the physics of ice surface morphology growth. This experiment features half-meter-scale cryogenic ice samples, cryogenic radiative sink environment, vacuum conditions, and diurnal cycling solar simulation. The experiment also includes several smaller fixed-geometry vacuum chambers for ice simulation at Earth-like and intermediate temperature and vacuum conditions for development of surface morphology growth scaling relations. Additionally, an ice cutting facility built on a similar platform provides qualitative data on the mechanical behavior of cryogenic ice with impurities under vacuum, and allows testing of ice cutting/sampling tools relevant for landing spacecraft. A larger cutting facility is under construction at JPL, which will provide more quantitative data and allow full-scale sampling tool tests. Another facility, the JPL Ice Physics Laboratory, features icy analog simulant preparation abilities that range icy solar system objects such as Mars, Ceres and the icy satellites of Saturn and Jupiter. In addition, the Ice Physics Lab has unique facilities for Icy Analog Tidal Simulation and Rheological Studies of Cryogenic Icy Slurries, as well as equipment to perform thermal and mechanical properties testing on icy analog materials and their response to sinusoidal tidal stresses.

A survey of residents' experience with patient safety and quality improvement concepts in radiation oncology.

PubMed

Spraker, Matthew B; Nyflot, Matthew; Hendrickson, Kristi; Ford, Eric; Kane, Gabrielle; Zeng, Jing

The safety and quality of radiation therapy have recently garnered increased attention in radiation oncology (RO). Although patient safety guidelines expect physicians and physicists to lead clinical safety and quality improvement (QI) programs, trainees' level of exposure to patient safety concepts during training is unknown. We surveyed active medical and physics RO residents in North America in February 2016. Survey questions involved demographics and program characteristics, exposure to patient safety topics, and residents' attitude regarding their safety education. Responses were collected from 139 of 690 (20%) medical and 56 of 248 (23%) physics RO residents. More than 60% of residents had no exposure or only informal exposure to incident learning systems (ILS), root cause analysis, failure mode and effects analysis (FMEA), and the concepts of human factors engineering. Medical residents had less exposure to FMEA than physics residents, and fewer medical than physics residents felt confident in leading FMEA in clinic. Only 27% of residents felt that patient safety training was adequate in their program. Experiential learning through practical workshops was the most desired educational modality, preferred over web-based learning. Residents training in departments with ILS had greater exposure to patient safety concepts and felt more confident leading clinical patient safety and QI programs than residents training in departments without an ILS. The survey results show that most residents have no or only informal exposure to important patient safety and QI concepts and do not feel confident leading clinical safety programs. This represents a gaping need in RO resident education. Educational programs such as these can be naturally developed as part of an incident learning program that focuses on near-miss events. Future research should assess the needs of RO program directors to develop effective RO patient safety and QI training programs. Copyright © 2016 American Society of Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Scientific Assessment Group for Experiments in Non-Accelerator Physics (SAGENAP)

DTIC Science & Technology

1997-03-01

sources cannot be distant cosmological sources because of the energy loss resulting from interactions with the cosmic microwave background radiation...least as importantly, it appears necessary for the development of a consistent picture of cosmology e.g. primordial nucleosynthesis) that there is a...Goldstone boson associated with this symmetry breaking is called the axion. This process is analogous to the mechanism leading to the Higgs particle

Effects of sterilization treatments on the analysis of TOC in water samples.

PubMed

Shi, Yiming; Xu, Lingfeng; Gong, Dongqin; Lu, Jun

2010-01-01

Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants. However, the effects of biological pretreatment (sterilization) on organic matter often have a negative impact on such experiments. Based on the principle of water total organic carbon (TOC) analysis, the effects of physical sterilization treatments on determination of TOC and other water quality parameters were investigated. The results revealed that two conventional physical sterilization treatments, autoclaving and 60Co gamma-radiation sterilization, led to the direct decomposition of some organic pollutants, resulting in remarkable errors in the analysis of TOC in water samples. Furthermore, the extent of the errors varied with the intensity and the duration of sterilization treatments. Accordingly, a novel sterilization method for water samples, 0.45 microm micro-filtration coupled with ultraviolet radiation (MCUR), was developed in the present study. The results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality parameters. Before and after sterilization treatments, the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.

Physical Characteristics of Arctic Clouds from Ground-based Remote-sensing with a Polarized Micro-Pulse Lidar and a 95-GHz Cloud Radar in Ny-Ålesund, Svalbard

NASA Astrophysics Data System (ADS)

Shiobara, M.; Takano, T.; Okamoto, H.; Yabuki, M.

2015-12-01

Clouds and aerosols are key elements having a potential to change climate by their radiative effects on the energy balance in the global climate system. In the Arctic, we have been continuing ground-based remote-sensing measurements for clouds and aerosols using a sky-radiometer, a micro-pulse lidar (MPL) and an all-sky camera in Ny-Ålesund (78.9N, 11.9E), Svalbard since early 2000's. In addition to such regular operations, several new measurements have been performed with a polarization MPL since August 2013, a 95GHz Doppler cloud radar since September 2013, and a dual frequency microwave radiometer since June 2014. An intensive field experiment for cloud-aerosol-radiation interaction study named A-CARE (PI: J. Ukita) was conducted for water clouds in the period of 23 June - 13 July 2014 and for mixed phase clouds in the period of 30 March - 23 April 2015 in Ny-Alesund. The experiment consisted of ground-based remote-sensing and in-situ cloud microphysics measurements. In this paper, preliminary results from these remote-sensing measurements will be presented, particularly in regard to physical characteristics of Arctic clouds based on radar-lidar collocated observation in Ny-Ålesund.

The proceedings of the 1st international workshop on laboratory astrophysics experiments with large lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Remington, B.A.; Goldstein, W.H.

1996-08-09

The world has stood witness to the development of a number of highly sophisticated and flexible, high power laser facilities (energies up to 50 kJ and powers up to 50 TW), driven largely by the world-wide effort in inertial confinement fusion (ICF). The charter of diagnosing implosions with detailed, quantitative measurements has driven the ICF laser facilities to be exceedingly versatile and well equipped with diagnostics. Interestingly, there is considerable overlap in the physics of ICF and astrophysics. Both typically involve compressible radiative hydrodynamics, radiation transport, complex opacities, and equations of state of dense matter. Surprisingly, however, there has beenmore » little communication between these two communities to date. With the recent declassification of ICF in the USA, and the approval to commence with construction of the next generation ``superlasers``, the 2 MJ National Ignition Facility in the US, and its equivalent, the LMJ laser in France, the situation is ripe for change. . Given the physics similarities that exist between ICF and astrophysics, one strongly suspects that there should exist regions of overlap where supporting research on the large lasers could be beneficial to the astrophysics community. As a catalyst for discussions to this end, Lawrence Livermore National Laboratory sponsored this workshop. Approximately 100 scientists attended from around the world, representing eight countries: the USA, Canada, UK, France, Germany, Russia, Japan, and Israel. A total of 30 technical papers were presented. The two day workshop was divided into four sessions, focusing on nonlinear hydrodynamics, radiative hydrodynamics, radiation transport, and atomic physics-opacities. Copies of the presentations are contained in these proceedings.« less

Laser-plasma interaction experiments and diagnostics at NRL (Naval Research Laboratory). Memorandum report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ripin, B.H.; Grun, J.; Herbst, M.J.

Laser plasma interaction experiments have now advanced to the point where very quantitative measurements are required to elucidate the physic issues important for laser fusion and other applications. Detailed time-resolved knowledge of the plasma density, temperature, velocity gradients, spatial structure, heat flow characteristics, radiation emission, etc, are needed over tremendou ranges of plasma density and temperature. Moreover, the time scales are very short, aggrevating the difficulty of the measurements further. Nonetheless, such substantial progress has been made in diagnostic development during the past few years that we are now able to do well diagnosed experiments. In this paper the authorsmore » review recent diagnostic developments for laser-plasma interactions, outline their regimes of applicability, and show examples of their utility. In addition to diagnostics for the high densities and temperature characteristic of laser fusion physics studies, diagnostics designed to study the two-stream interactions of laser created plasma flowing through an ambient low density plasma will be described.« less

Heat transfer from nanoparticles: A corresponding state analysis

PubMed Central

Merabia, Samy; Shenogin, Sergei; Joly, Laurent; Keblinski, Pawel; Barrat, Jean-Louis

2009-01-01

In this contribution, we study situations in which nanoparticles in a fluid are strongly heated, generating high heat fluxes. This situation is relevant to experiments in which a fluid is locally heated by using selective absorption of radiation by solid particles. We first study this situation for different types of molecular interactions, using models for gold particles suspended in octane and in water. As already reported in experiments, very high heat fluxes and temperature elevations (leading eventually to particle destruction) can be observed in such situations. We show that a very simple modeling based on Lennard–Jones (LJ) interactions captures the essential features of such experiments and that the results for various liquids can be mapped onto the LJ case, provided a physically justified (corresponding state) choice of parameters is made. Physically, the possibility of sustaining very high heat fluxes is related to the strong curvature of the interface that inhibits the formation of an insulating vapor film. PMID:19571000

Between Industry and Academia: A Physicist's Experiences at The Aerospace Corporation

NASA Astrophysics Data System (ADS)

Camparo, James

2005-03-01

The Aerospace Corporation is a nonprofit company whose purposes are exclusively scientific: to provide research, development, and advisory services for space programs that serve the national interest, primarily the Air Force's Space and Missile Systems Center and the National Reconnaissance Office. The corporation's laboratory has a staff of about 150 scientists who conduct research in fields ranging from Space Sciences to Material Sciences and from Analytical Chemistry to Atomic Physics. As a consequence, Aerospace stands midway between an industrial research laboratory, focused on product development, and academic/national laboratories focused on basic science. Drawing from Dr. Camparo's personal experiences, the presentation will discuss advantages and disadvantages of a career at Aerospace, including the role of publishing in peer-reviewed journals and the impact of work on family life. Additionally, the presentation will consider the balance between basic physics, applied physics, and engineering in the work at Aerospace. Since joining Aerospace in 1981, Dr. Camparo has worked as an atomic physicist specializing in the area of atomic clocks, and has had the opportunity to experiment and publish on a broad range of research topics including: the stochastic-field/atom interaction, radiation effects on semiconductor materials, and stellar scintillation.

Study of shock waves and related phenomena motivated by astrophysics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drake, R. P.; Keiter, P. A.; Kuranz, C. C.

This study discusses the recent research in High-Energy-Density Physics at our Center. Our work in complex hydrodynamics is now focused on mode coupling in the Richtmyer-Meshkov process and on the supersonic Kelvin-Helmholtz instability. These processes are believed to occur in a wide range of astrophysical circumstances. In radiation hydrodynamics, we are studying radiative reverse shocks relevant to cataclysmic variable stars. Our work on magnetized flows seeks to produce magnetized jets and study their interactions. We build the targets for all these experiments, and simulate them using our CRASH code. We also conduct diagnostic research, focused primarily on imaging x-ray spectroscopymore » and its applications to scattering and fluorescence.« less

Spectroscopy of X-ray Photoionized Plasmas in the Laboratory

NASA Astrophysics Data System (ADS)

Liedahl, Duane A.; Loisel, Guillaume; Bailey, James E.; Nagayama, Taisuke; Hansen, Stephanie B.; Rochau, Gregory; Fontes, Christopher J.; Mancini, Roberto; Kallman, Timothy R.

2018-06-01

The physical processes operating in astrophysical plasmas --- heating, cooling, ionization, recombination, level population kinetics, and radiation transport --- are all accessible to observation in the laboratory. What distinguishes X-ray photoionized plasmas from the more common case of high-temperature collisionally-ionized plasmas is the elevated level of importance of the radiation/matter interaction. The advent of laboratory facilities with the capability to generate high-powered X-ray sources has provided the means by which to study this interaction, which is also fundamental to active galactic nuclei and other accretion-powered objects. We discuss recent and ongoing experiments, with an emphasis on X-ray spectroscopic measurements of silicon plasmas obtained at the Sandia Z Pulsed Power Facility.

The Majorana Parts Tracking Database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abgrall, N.; Aguayo, E.; Avignone, F. T.

2015-04-01

The MAJORANA DEMONSTRATOR is an ultra-low background physics experiment searching for the neutrinoless double beta decay of 76Ge. The MAJORANA Parts Tracking Database is used to record the history of components used in the construction of the DEMONSTRATOR. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provides a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation. A web application for data entry and a radiation exposure calculator have been developedmore » as tools for achieving the extreme radiopurity required for this rare decay search.« less

Study of shock waves and related phenomena motivated by astrophysics

DOE PAGES

Drake, R. P.; Keiter, P. A.; Kuranz, C. C.; ...

2016-04-01

This study discusses the recent research in High-Energy-Density Physics at our Center. Our work in complex hydrodynamics is now focused on mode coupling in the Richtmyer-Meshkov process and on the supersonic Kelvin-Helmholtz instability. These processes are believed to occur in a wide range of astrophysical circumstances. In radiation hydrodynamics, we are studying radiative reverse shocks relevant to cataclysmic variable stars. Our work on magnetized flows seeks to produce magnetized jets and study their interactions. We build the targets for all these experiments, and simulate them using our CRASH code. We also conduct diagnostic research, focused primarily on imaging x-ray spectroscopymore » and its applications to scattering and fluorescence.« less

Radiation resistance of acetal copolymers (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolters, E.; Roesinger, S.

1973-01-01

For the radiation sterilization of equipment and containers made from plastic material, a dose of 2.5 x 10/sup 4/ J/kg (2.5 Mrad) is normally used. Experiments are described which show the influence of the sterilization doses applied in practice on the physical properties of the acetal copolymer Hostaform. Although a certain destruction and simultaneously a reduction in viscous properties are observed as a result of irradiations with gamma rays up to 2.5 x 10/sup 4/ J/kg, the tensile strength remains practically unchanged. Hence gamma -ray sterilization can be applied if there are no special requirements as to the mechanical propertiesmore » of the sterile equipment. (GE)« less

SESAME: science for intercultural dialogue

NASA Astrophysics Data System (ADS)

Paolucci, Giorgio

2015-04-01

SESAME is an international research organization located in Jordan, in the Middle-East. Based on a synchrotron radiation source, it will allow scientist from the region to access a world-class research infrastructure to boost their research and scientific knowledge. At the same time its international nature will allow scientists with different cultures, different religions and different experiences to interact with each other. It is therefore an excellent opportunity for the regional development. The talk will introduce synchrotron radiation as a method to study matter, with examples in various disciplines, from physics to life sciences. The organisational structure of SESAME will be described, emphasising how this project is expected to enhance cooperation and mutual comprehension in the Middle East.

Using cosmic microwave background radiation analysis tools for flow anisotropies in relativistic heavy-ion collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Ananta P.; Mohapatra, Ranjita K.; Saumia, P. S.

2010-03-15

Recently we have shown that there are crucial similarities in the physics of cosmic microwave background radiation (CMBR) anisotropies and the flow anisotropies in relativistic heavy-ion collision experiments (RHICE). We also argued that, following CMBR anisotropy analysis, a plot of root-mean-square values of the flow coefficients, calculated in a laboratory-fixed frame for RHICE, can yield important information about the nature of initial state anisotropies and their evolution. Here we demonstrate the strength of this technique by showing that elliptic flow for noncentral collisions can be directly determined from such a plot without any need for the determination of the eventmore » plane.« less

Solar and terrestrial physics. [effects of solar activities on earth environment

NASA Technical Reports Server (NTRS)

1975-01-01

The effects of solar radiation on the near space and biomental earth, the upper atmosphere, and the magnetosphere are discussed. Data obtained from the OSO satellites pertaining to the solar cycle variation of extreme ultraviolet (EUV) radiation are analyzed. The effects of solar cycle variation of the characteristics of the solar wind are examined. The fluid mechanics of shock waves and the specific relationship to the characteristics of solar shock waves are investigated. The solar and corpuscular heating of the upper atmosphere is reported based on the findings of the AEROS and NATE experiments. Seasonal variations of the upper atmosphere composition are plotted based on OGO-6 mass spectrometer data.

ROENTGEN: case-based reasoning and radiation therapy planning.

PubMed Central

Berger, J.

1992-01-01

ROENTGEN is a design assistant for radiation therapy planning which uses case-based reasoning, an artificial intelligence technique. It learns both from specific problem-solving experiences and from direct instruction from the user. The first sort of learning is the normal case-based method of storing problem solutions so that they can be reused. The second sort is necessary because ROENTGEN does not, initially, have an internal model of the physics of its problem domain. This dependence on explicit user instruction brings to the forefront representational questions regarding indexing, failure definition, failure explanation and repair. This paper presents the techniques used by ROENTGEN in its knowledge acquisition and design activities. PMID:1482869

A numerical modeling study of the physical mechanisms causing radiation to promote the genesis of a tropical cyclone

NASA Astrophysics Data System (ADS)

Nicholls, M.; Pielke, R., Sr.; Smith, W. H.; Saleeby, S. M.; Wood, N.

2016-12-01

Several cloud-resolving numerical modeling results indicate that radiative forcing significantly accelerates tropical cyclogenesis. The primary mechanism appears to be differential radiative forcing between a relatively cloud-free environment and a developing tropical disturbance that generates circulations that influence convective activity in the core of the system, a mechanism first suggested by Gray and Jacobson. A dynamical perspective of this mechanism is taken by viewing it in terms of the lateral propagation of thermally driven gravity wave circulations. Numerical model experiments indicate that as an expansive stratiform cloud layer forms aloft the long wave cooling is reduced at low and mid levels. During the daytime there is not a very large differential radiative forcing between the environment and the cloud system, but it becomes significant at night when there is strong radiative clear sky cooling of the environment. Thermally driven circulations, are induced characterized by relatively weak subsidence in the environment but considerably stronger upward motion in the system core. This leads to a cooling tendency and increased relative humidity at night which appears to be a major factor in enhancing convective activity thereby leading in the mean to an increased rate of genesis. The increased upward motion and relative humidity that occurs throughout a deep layer is likely to aid in the triggering of convection, and provide a more favorable local environment at mid-levels for maintenance of buoyancy in convective cells due to a reduction of the detrimental effects of dry air entrainment. In order to clarify the effects of radiation the radiative forcing occurring in a fully physics simulation is imposed as a forcing term on the thermodynamic equation in a simulation without microphysics or radiation included to examine the induced circulations and the resultant thermodynamic changes that can influence convective development.

The role of obesity and physical activity in non-specific and radiating low back pain: the Young Finns study.

PubMed

Shiri, Rahman; Solovieva, Svetlana; Husgafvel-Pursiainen, Kirsti; Telama, Risto; Yang, Xiaolin; Viikari, Jorma; Raitakari, Olli T; Viikari-Juntura, Eira

2013-06-01

To study the effects of obesity, physical activity, and change in physical activity on the incidence of low back pain and explore whether obesity modifies the effects of physical activity. As part of the ongoing Young Finns Study, 1224 subjects aged 24-39 years free from low back pain during the preceding 12 months at baseline in 2001 were included. Obesity was defined based on the body mass index (BMI) and waist circumference, and physical activity was assessed by the metabolic equivalent of task (MET) index in 2001 and 2007. Abdominal obesity, defined by an increased waist circumference, was associated with an increased incidence of radiating low back pain (adjusted odds ratio (OR) = 1.7 and 95% confidence interval (CI) 1.1-2.7), while it had no effect on non-specific low back pain. BMI was associated neither with the incidence of radiating low back pain nor with non-specific low back pain. Compared with subjects who stayed active during follow-up, those with a low level of physical activity (adjusted OR = 2.0 and 95% CI 1.1-3.5) and active subjects who further increased their physical activity during follow-up (OR = 3.1 and 95% CI 1.5-6.7) had a higher incidence of radiating low back pain. Low level of physical activity was associated with an increased incidence of radiating low back pain in obese (OR = 3.3 and 95% 1.1-10.4), but not in non-overweight subjects (OR = 1.1 and 95% CI 0.6-1.9). Physical activity was not associated with non-specific low back pain. Our findings indicate that both obesity and low level of physical activity are independent risk factors of radiating low back pain. The current findings propose a U-shaped relation between physical activity and radiating low back pain. Moderate level of physical activity is recommended for the prevention of low back pain, especially in obese individuals. In all, our findings imply that obese individuals should stay physically active, even if they may not lose weight. Copyright © 2013 Elsevier Inc. All rights reserved.

Courses in Physics in Medical Colleges

ERIC Educational Resources Information Center

Physics Education, 1975

1975-01-01

Provides information concerning programs in medical physics, radiation biology, and radiation physics at eight British medical colleges. Each institution is separately listed, and the provided information typically includes program descriptions, graduate programs, and main branches of research. (MLH)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arimura, Hidetaka, E-mail: arimurah@med.kyushu-u.ac.jp; Kamezawa, Hidemi; Jin, Ze

Good relationships between computational image analysis and radiological physics have been constructed for increasing the accuracy of medical diagnostic imaging and radiation therapy in radiological physics. Computational image analysis has been established based on applied mathematics, physics, and engineering. This review paper will introduce how computational image analysis is useful in radiation therapy with respect to radiological physics.

Gravity and decoherence: the double slit experiment revisited

NASA Astrophysics Data System (ADS)

Samuel, Joseph

2018-02-01

The double slit experiment is iconic and widely used in classrooms to demonstrate the fundamental mystery of quantum physics. The puzzling feature is that the probability of an electron arriving at the detector when both slits are open is not the sum of the probabilities when the slits are open separately. The superposition principle of quantum mechanics tells us to add amplitudes rather than probabilities and this results in interference. This experiment defies our classical intuition that the probabilities of exclusive events add. In understanding the emergence of the classical world from the quantum one, there have been suggestions by Feynman, Diosi and Penrose that gravity is responsible for suppressing interference. This idea has been pursued in many different forms ever since, predominantly within Newtonian approaches to gravity. In this paper, we propose and theoretically analyse two ‘gedanken’ or thought experiments which lend strong support to the idea that gravity is responsible for decoherence. The first makes the point that thermal radiation can suppress interference. The second shows that in an accelerating frame, Unruh radiation does the same. Invoking the Einstein equivalence principle to relate acceleration to gravity, we support the view that gravity is responsible for decoherence.

Study of The Non-linear Uv Dosimetry In Simulated Extraterrestrial Conditions

NASA Astrophysics Data System (ADS)

Berces, A.; Kerekgyarto, T.; Ronto, G.; Lammer, H.; Kargl, G.; Komle, N. I.

In UV biological dosimetry the UV dose scale is additive starting at a value of zero ac- cording to the definition of CIE (Technical Report TC-6-18). The biological dose can be defined by a measured end-effect. In our dosimeters (phage T7 and uracil dosime- ter) exposed to natural (terrestrial) UV radiation the proportion of pyrimidin photo- products among the total photoproducts is smaller than 10 and the linear correlation between the biological and physical dose is higher than 0.9. According to the experi- mental data this linear relationship is often not valid. We observed that UV radiation did not only induce dimerisation but shorter wavelengths caused monomerisation of pyrimidin dimers. Performing the irradiation in oxygen free environment and using a Deuterium lamp as UV source, we could increase monomerisation against dimerisa- tion thus the DNA-based dosimetrySs additivity rule is not fulfilled in these conditions. In this study we will demonstrate those non-linear experiments which constitute the basis of our biological experiments on the International Space Station.

On physical and numerical instabilities arising in simulations of non-stationary radiatively cooling shocks

NASA Astrophysics Data System (ADS)

Badjin, D. A.; Glazyrin, S. I.; Manukovskiy, K. V.; Blinnikov, S. I.

2016-06-01

We describe our modelling of the radiatively cooling shocks and their thin shells with various numerical tools in different physical and calculational setups. We inspect structure of the dense shell, its formation and evolution, pointing out physical and numerical factors that sustain its shape and also may lead to instabilities. We have found that under certain physical conditions, the circular shaped shells show a strong bending instability and successive fragmentation on Cartesian grids soon after their formation, while remain almost unperturbed when simulated on polar meshes. We explain this by physical Rayleigh-Taylor-like instabilities triggered by corrugation of the dense shell surfaces by numerical noise. Conditions for these instabilities follow from both the shell structure itself and from episodes of transient acceleration during re-establishing of dynamical pressure balance after sudden radiative cooling onset. They are also easily excited by physical perturbations of the ambient medium. The widely mentioned non-linear thin shell instability, in contrast, in tests with physical perturbations is shown to have only limited chances to develop in real radiative shocks, as it seems to require a special spatial arrangement of fluctuations to be excited efficiently. The described phenomena also set new requirements on further simulations of the radiatively cooling shocks in order to be physically correct and free of numerical artefacts.

A Review of Hypersonics Aerodynamics, Aerothermodynamics and Plasmadynamics Activities within NASA's Fundamental Aeronautics Program

NASA Technical Reports Server (NTRS)

Salas, Manuel D.

2007-01-01

The research program of the aerodynamics, aerothermodynamics and plasmadynamics discipline of NASA's Hypersonic Project is reviewed. Details are provided for each of its three components: 1) development of physics-based models of non-equilibrium chemistry, surface catalytic effects, turbulence, transition and radiation; 2) development of advanced simulation tools to enable increased spatial and time accuracy, increased geometrical complexity, grid adaptation, increased physical-processes complexity, uncertainty quantification and error control; and 3) establishment of experimental databases from ground and flight experiments to develop better understanding of high-speed flows and to provide data to validate and guide the development of simulation tools.

Early work-related physical exposures and low back pain in midlife: the Cardiovascular Risk in Young Finns Study.

PubMed

Lallukka, T; Viikari-Juntura, E; Viikari, J; Kähönen, M; Lehtimäki, T; Raitakari, O T; Solovieva, S

2017-03-01

To examine whether heavy physical workload in young adulthood increases the risk of local and radiating low back pain (LBP) in midlife. Longitudinal nationally representative Young Finns Study data among women (n=414) and men (n=324), aged 18-24 years in 1986 (baseline), were used. Physical heaviness of work was reported at baseline and follow-up (2007), and local and radiating LBP at follow-up. Covariates were age, smoking and body mass index. Logistic regression was used to examine the associations between physical heaviness of work and LBP. Additionally, the mediating effect of back pain at baseline was examined (the Sobel test). After adjustment for the covariates, and as compared with sedentary/light physical workload, heavy physical workload was associated with radiating LBP among women (OR 4.09, 95% CI 1.62 to 10.31) and men (OR 2.01, 95% CI 1.06 to 3.82). Among men, early back pain mediated the association (p value from the Sobel test=0.006). Among women, early exposure to physically heavy work showed the most consistent associations, while early and late exposures were associated with radiating and local LBP among men. Persistently heavy physical work was associated with radiating LBP among women and men. Physically heavy work at a young age can have a long-lasting effect on the risk of LBP, radiating LBP in particular. These results highlight the need to consider early and persistent exposures to prevent the adverse consequences of physical workload for the low back. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Phase transformation and microstructural evolution of nanostructured oxides and nitrides under ion irradiations

NASA Astrophysics Data System (ADS)

Lu, Fengyuan

Material design at the nanometer scale is an effective strategy for developing advanced materails with enhanced radiation tolerance for advanced nuclear energy systems as high densities of surfaces and interfaces of the nanostructured materials may behave as effective sinks for defect recovery. However, nanostructured materials may not be intrinsically radiation tolerant, and the interplay among the factors of crystal size, temperature, chemical composition, surface energy and radiation conditions may eventually determine material radiation behaviors. Therefore, it is necessary to understand the radiation effects of nanostructured materials and the underlying physics for the design of advanced nanostructured nuclear materials. The main objective of this doctoral thesis is to study the behavior of nanostructured oxides and nitrides used as fuel matrix and waste forms under extreme radiation conditions with the focus of phase transformation, microstructural evolution and damage mechanisms. Radiation experiments were performed using energetic ion beam techniques to simulate radiation damage resulting from energetic neutrons, alpha-decay events and fission fragments, and various experimental approaches were employed to characterize materials’ microstructural evolution and phase stability upon intense radiation environments including transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. Thermal annealing experiments indicated that nanostructured ZrO2 phase stability is strongly affected by the grain size. Radiation results on nanostructured ZrO2 indicated that thermodynamically unstable or metastable high temperature phases can be induced by energetic beam irradiation at room temperature. Various phase transformation among different polymorphs of monoclinic, tetragonal and amorphous states can be induced, and different mechanisms are responsible for structural transformations including oxygen vacancies accumulation upon displacive damage, radiation-assistant recrystallization and thermal spike by ionization radiation. The radiation response of nanosized pyrochlores indicated that the radiation tolerance of nanoceramics is highly dependent on the composition and size. Nanosized tantalate pyrochlores KxLnyTa2O 7-v (Ln = Gd, Y, Lu) with the average grain size around 10 - 15 nm are highly sensitive to radiation-induced amorphization. The pyrochlore A to B site ionic radius ratio rA/rB is crucial in determining the radiation tolerance of pyrochlores, and a minimum rA/rB of 1.605 exists for the occurring of radiation induced amorphization. The interplay among chemical compositions, structural deviation and grain size eventually determines the phase stability and structural transformation processes of tantalate pyrochlores under intense radiation environments. ZrN shows extremely high phase stability under both displacive ion irradiation and ionizing swift heavy ion irradiation. However, a contraction in lattice constant up to ~ 1.42 % can be induced in nanocrystalline ZrN irradiated with displacive ion beams. In contrast, the strongly ionizing swift heavy ions cannot induce any lattice contraction. Such lattice contractions may be due to a negative strain field in the ZrN nanograins related to N vacancies built up upon displacive radiation. Ion irradiations also lead to the formation of orthorhombic ZrSi phase at the interface between ZrN and Si substrate, resulting from atom mixing and precipitation upon ion irradiations. The fundamental knowledge provides critical data for assessing and quantifying nanostructured ceramics as fuel matrix and waste forms utilized in the extreme environments of advanced nuclear energy systems. Further possibilities are being pursued in manipulating microstructure at the nano-scale, controlling phase stability and tailoring the physical properties of materials for various important engineering applications.

Constitutive expression of tdTomato protein as a cytotoxicity and proliferation marker for space radiation biology

NASA Astrophysics Data System (ADS)

Chishti, Arif A.; Hellweg, Christine E.; Berger, Thomas; Baumstark-Khan, Christa; Feles, Sebastian; Kätzel, Thorben; Reitz, Günther

2015-01-01

The radiation risk assessment for long-term space missions requires knowledge on the biological effectiveness of different space radiation components, e.g. heavy ions, on the interaction of radiation and other space environmental factors such as microgravity, and on the physical and biological dose distribution in the human body. Space experiments and ground-based experiments at heavy ion accelerators require fast and reliable test systems with an easy readout for different endpoints. In order to determine the effect of different radiation qualities on cellular proliferation and the biological depth dose distribution after heavy ion exposure, a stable human cell line expressing a novel fluorescent protein was established and characterized. tdTomato, a red fluorescent protein of the new generation with fast maturation and high fluorescence intensity, was selected as reporter of cell proliferation. Human embryonic kidney (HEK/293) cells were stably transfected with a plasmid encoding tdTomato under the control of the constitutively active cytomegalovirus (CMV) promoter (ptdTomato-N1). The stably transfected cell line was named HEK-ptdTomato-N1 8. This cytotoxicity biosensor was tested by ionizing radiation (X-rays and accelerated heavy ions) exposure. As biological endpoints, the proliferation kinetics and the cell density reached 100 h after irradiation reflected by constitutive expression of the tdTomato were investigated. Both were reduced dose-dependently after radiation exposure. Finally, the cell line was used for biological weighting of heavy ions of different linear energy transfer (LET) as space-relevant radiation quality. The relative biological effectiveness of accelerated heavy ions in reducing cellular proliferation peaked at an LET of 91 keV/μm. The results of this study demonstrate that the HEK-ptdTomato-N1 reporter cell line can be used as a fast and reliable biosensor system for detection of cytotoxic damage caused by ionizing radiation.

Sperm quality and DNA damage in men from Jilin Province, China, who are occupationally exposed to ionizing radiation.

PubMed

Zhou, D D; Hao, J L; Guo, K M; Lu, C W; Liu, X D

2016-03-22

Long-term radiation exposure affects human health. Ionizing radiation has long been known to raise the risk of cancer. In addition to high doses of radiation, low-dose ionizing radiation might increase the risk of cardiovascular disease, lens opacity, and some other non-cancerous diseases. Low- and high-dose exposures to ionizing radiation elicit different signaling events at the molecular level, and may involve different response mechanisms. The health risks arising from exposure to low doses of ionizing radiation should be re-evaluated. Health workers exposed to ionizing radiation experience low-dose radiation and have an increased risk of hematological malignancies. Reproductive function is sensitive to changes in the physical environment, including ionizing radiation. However, data is scarce regarding the association between occupational radiation exposure and risk to human fertility. Sperm DNA integrity is a functional parameter of male fertility evaluation. Hence, we aimed to report sperm quality and DNA damage in men from Jilin Province, China, who were occupationally exposed to ionizing radiation. Sperm motility and normal morphology were significantly lower in the exposed compared with the non-exposed men. There was no statistically significant difference in sperm concentration between exposed and non-exposed men. The sperm DNA fragmentation index was significantly higher in the exposed than the non-exposed men. Chronic long-term exposure to low doses of ionizing radiation could affect sperm motility, normal morphology, and the sperm DNA fragmentation index in the Chinese population. Sperm quality and DNA integrity are functional parameters that could be used to evaluate occupational exposure to ionizing radiation.

Radiation protection aspects of EMITEL Encyclopaedia of Medical Physics.

PubMed

Stoeva, M; Tabakov, S; Lewis, C; Tabakova, V; Thurston, J; Smith, P

2015-07-01

The Encyclopaedia of Medical Physics EMITEL was developed under the EU pilot project European Medical Imaging Technology e-Encyclopaedia for Lifelong Learning. This large reference material includes 3400 articles on 2100 pages supported by thousands of illustrations. All materials are available free at the website, www.emitel2.eu. The articles are grouped in seven categories--physics of: X-ray diagnostic radiology, nuclear medicine, radiotherapy, magnetic resonance imaging, ultrasound imaging, radiation protection and general terms. The radiation protection part of EMITEL includes 450 articles. These were organised in several sub-groups including: nuclear and atomic physics; ionizing radiation interactions and biological effects; radiation detection and measurement; dosimetric quantities and units; and general radiation protection and international bodies. EMITEL project was developed over 3 y and attracted as contributors 250+ senior specialists from 35 countries. After its successful launching, EMITEL is actively used by thousands of professionals around the world. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Operational health physics.

PubMed

Miller, Kenneth L

2005-06-01

A review of the operational health physics papers published in Health Physics and Operational Radiation Safety over the past fifteen years indicated seventeen general categories or areas into which the topics could be readily separated. These areas include academic research programs, use of computers in operational health physics, decontamination and decommissioning, dosimetry, emergency response, environmental health physics, industrial operations, medical health physics, new procedure development, non-ionizing radiation, radiation measurements, radioactive waste disposal, radon measurement and control, risk communication, shielding evaluation and specification, staffing levels for health physics programs, and unwanted or orphan sources. That is not to say that there are no operational papers dealing with specific areas of health physics, such as power reactor health physics, accelerator health physics, or governmental health physics. On the contrary, there have been a number of excellent operational papers from individuals in these specialty areas and they are included in the broader topics listed above. A listing and review of all the operational papers that have been published is beyond the scope of this discussion. However, a sampling of the excellent operational papers that have appeared in Health Physics and Operational Radiation Safety is presented to give the reader the flavor of the wide variety of concerns to the operational health physicist and the current areas of interest where procedures are being refined and solutions to problems are being developed.

Operational health physics.

PubMed

Miller, Kenneth L

2005-01-01

A review of the operational health physics papers published in Health Physics and Operational Radiation Safety over the past fifteen years indicated seventeen general categories or areas into which the topics could be readily separated. These areas include academic research programs, use of computers in operational health physics, decontamination and decommissioning, dosimetry, emergency response, environmental health physics, industrial operations, medical health physics, new procedure development, non-ionizing radiation, radiation measurements, radioactive waste disposal, radon measurement and control, risk communication, shielding evaluation and specification, staffing levels for health physics programs, and unwanted or orphan sources. That is not to say that there are no operational papers dealing with specific areas of health physics, such as power reactor health physics, accelerator health physics, or governmental health physics. On the contrary, there have been a number of excellent operational papers from individuals in these specialty areas and they are included in the broader topics listed above. A listing and review of all the operational papers that have been published is beyond the scope of this discussion. However, a sampling of the excellent operational papers that have appeared in Health Physics and Operational Radiation Safety is presented to give the reader the flavor of the wide variety of concerns to the operational health physicist and the current areas of interest where procedures are being refined and solutions to problems are being developed.

Astronomy and Cancer Research: X-Rays and Nanotechnology from Black Holes to Cancer Therapy

NASA Astrophysics Data System (ADS)

Pradhan, Anil K.; Nahar, Sultana N.

It seems highly unlikely that any connection is to be found between astronomy and medicine. But then it also appears to be obvious: X-rays. However, that is quite superficial because the nature of X-rays in the two disciplines is quite different. Nevertheless, we describe recent research on exactly that kind of link. Furthermore, the linkage lies in atomic physics, and via spectroscopy which is a vital tool in astronomy and may also be equally valuable in biomedical research. This review begins with the physics of black hole environments as viewed through X-ray spectroscopy. It is then shown that similar physics can be applied to spectroscopic imaging and therapeutics using heavy-element (high-Z) moieties designed to target cancerous tumors. X-ray irradiation of high-Z nanomaterials as radiosensitizing agents should be extremely efficient for therapy and diagnostics (theranostics). However, broadband radiation from conventional X-ray sources (such as CT scanners) results in vast and unnecessary radiation exposure. Monochromatic X-ray sources are expected to be considerably more efficient. We have developed a new and comprehensive methodology—Resonant Nano-Plasma Theranostics (RNPT)—that encompasses the use of monochromatic X-ray sources and high-Z nanoparticles. Ongoing research entails theoretical computations, numerical simulations, and in vitro and in vivo biomedical experiments. Stemming from basic theoretical studies of Kα resonant photoabsorption and fluorescence in all elements of the Periodic Table, we have established a comprehensive multi-disciplinary program involving researchers from physics, chemistry, astronomy, pathology, radiation oncology and radiology. Large-scale calculations necessary for theory and modeling are done at a variety of computational platforms at the Ohio Supercomputer Center. The final goal is the implementation of RNPT for clinical applications.

Advances in target design for heavy ion fusion

NASA Astrophysics Data System (ADS)

Callahan, D. A.; Tabak, M.; Bennett, G. R.; Cuneo, M. E.; Vesey, R. A.; Nikroo, A.; Czechowicz, D.; Steinman, D.

2005-12-01

Over the past few years, the emphasis in heavy ion target design has moved from the distributed radiator target to the 'hybrid' target because the hybrid target allows a larger beam focal spot than the distributed radiator (~5 mm radius rather than ~2 mm radius). The larger spot relaxes some of the requirements on the driver, but introduces some new target physics issues. Most notable is the use of shine shields and shims in the hohlraum to achieve symmetry rather than achieving symmetry by beam placement. The shim is a thin layer of material placed on or near the capsule surface to block a small amount of excess radiation. While we have been developing this technique for the heavy ion hybrid target, the technique can also be used in any indirect drive target. We have begun testing the concept of a shim to improve symmetry using a double-ended z-pinch hohlraum on the Sandia Z-machine. Experiments using shimmed thin wall capsules have shown that we can reverse the sign of a P2 asymmetry and significantly reduce the size of a P4 asymmetry. These initial experiments demonstrate the concept of a shim as another method for controlling early time asymmetries in ICF capsules.

Shielded Heavy-Ion Environment Linear Detector (SHIELD): an experiment for the Radiation and Technology Demonstration (RTD) Mission.

PubMed

Shavers, M R; Cucinotta, F A; Miller, J; Zeitlin, C; Heilbronn, L; Wilson, J W; Singleterry, R C

2001-01-01

Radiological assessment of the many cosmic ion species of widely distributed energies requires the use of theoretical transport models to accurately describe diverse physical processes related to nuclear reactions in spacecraft structures, planetary atmospheres and surfaces, and tissues. Heavy-ion transport models that were designed to characterize shielded radiation fields have been validated through comparison with data from thick-target irradiation experiments at particle accelerators. With the RTD Mission comes a unique opportunity to validate existing radiation transport models and guide the development of tools for shield design. For the first time, transport properties will be measured in free-space to characterize the shielding effectiveness of materials that are likely to be aboard interplanetary space missions. Target materials composed of aluminum, advanced composite spacecraft structure and other shielding materials, helium (a propellant) and tissue equivalent matrices will be evaluated. Large solid state detectors will provide kinetic energy and charge identification for incident heavy-ions and for secondary ions created in the target material. Transport calculations using the HZETRN model suggest that 8 g cm -2 thick targets would be adequate to evaluate the shielding effectiveness during solar minimum activity conditions for a period of 30 days or more.

International Conference on Vacuum Ultraviolet Radiation Physics, 8th, Lunds Universitet, Sweden, Aug. 4-8, 1986, Proceedings

NASA Technical Reports Server (NTRS)

Nilsson, Per-Olof (Editor); Nordgren, Joseph (Editor)

1987-01-01

The interactions of VUV radiation with solids are explored in reviews and reports of recent theoretical and experimental investigations from the fields of atomic and molecular physics, solid-state physics, and VUV instrumentation. Topics examined include photoabsorption and photoionization, multiphoton processes, plasma physics, VUV lasers, time-resolved spectroscopy, synchrotron radiation centers, solid-state spectroscopy, and dynamical processes involving localized levels. Consideration is given to the fundamental principles of photoemission, spin-polarized photoemission, inverse photoemission, semiconductors, organic materials, and adsorbates.

European organization for nuclear research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schoenbacher, H.; Tavlet, M.

1987-09-10

The CERN Intersecting Storage Rings (ISR) operated from 1971 to 1984. During that time high-energy physics experiments were carried out with 30 GeV colliding proton beams. At the end of this period the machine was decommissioned and dismantled. This involved the movement of about 1000 machine elements, e.g., magnets, vacuum pumps, rf cavities, etc., 2500 racks, 7000 shielding blocks, 3500 km of cables and 7 km of beam piping. All these items were considered to be radioactive until the contrary was proven. They were then sorted, either for storage and reuse or for radioactive or non-radioactive waste. The paper describesmore » the radiation protection surveillance of this project which lasted for five months. It includes the radiation protection standards, the control of personnel and materials, typical radioactivity levels and isotopes, as well as final cleaning and decommissioning of an originally restricted radiation area to a free accessible area.« less

Fluorescence dynamics of biological systems using synchrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gratton, E.; Mantulin, W.W.; Weber, G.

1996-09-01

A beamline for time-resolved fluorescence spectroscopy of biological systems is under construction at the Synchrotron Radiation Center. The fluorometer, operating in the frequency domain, will take advantage of the time structure of the synchrotron radiation light pulses to determine fluorescence lifetimes. Using frequency-domain techniques, the instrument can achieve an ultimate time resolution on the order of picoseconds. Preliminary experiments have shown that reducing the intensity of one of the fifteen electron bunches in the storage ring allows measurement of harmonic frequencies equivalent to the single-bunch mode. This mode of operation of the synchrotron significantly extends the range of lifetimes thatmore » can be measured. The wavelength range (encompassing the visible and ultraviolet), the range of measurable lifetimes, and the stability and reproducibility of the storage ring pulses should make this beamline a versatile tool for the investigation of the complex fluorescence decay of biological systems. {copyright} {ital 1996 American Institute of Physics.}« less

Preface: Solar energetic particles, solar modulation and space radiation: New opportunities in the AMS-02 Era

NASA Astrophysics Data System (ADS)

Bindi, Veronica

2017-08-01

Solar Energetic Particle (SEP) acceleration at high energies and their propagation through the heliosphere and into the magnetosphere are not well understood and are still a matter of debate. Our understanding of solar modulation and transport of different species of galactic cosmic rays (GCR) inside the heliosphere has been significantly improved; however, a lot of work still needs to be done. GCR and SEPs pose a significant radiation risk for people and technology in space, and thus it is becoming increasingly important to understand the space radiation environment. AMS-02 will provide brand new information with unprecedented statistics about GCR and SEPs. Both GCR and heliophysics experiments will contribute to the increased understanding of acceleration physics, and transport of particles in space with improved models. This will inevitably lead to better predictions of space weather and safer operations in space.

Multi-spectral pyrometer for gas turbine blade temperature measurement

NASA Astrophysics Data System (ADS)

Gao, Shan; Wang, Lixin; Feng, Chi

2014-09-01

To achieve the highest possible turbine inlet temperature requires to accurately measuring the turbine blade temperature. If the temperature of blade frequent beyond the design limits, it will seriously reduce the service life. The problem for the accuracy of the temperature measurement includes the value of the target surface emissivity is unknown and the emissivity model is variability and the thermal radiation of the high temperature environment. In this paper, the multi-spectral pyrometer is designed provided mainly for range 500-1000°, and present a model corrected in terms of the error due to the reflected radiation only base on the turbine geometry and the physical properties of the material. Under different working conditions, the method can reduce the measurement error from the reflect radiation of vanes, make measurement closer to the actual temperature of the blade and calculating the corresponding model through genetic algorithm. The experiment shows that this method has higher accuracy measurements.

KSC-02pd1661

NASA Image and Video Library

2002-10-28

KENNEDY SPACE CENTER, FLA. -- Workers in the Multi-Purpose Processing Facility at KSC lift the Solar Radiation and Climate Experiment (SORCE) spacecraft to move it to a workstand. SORCE arrived at Kennedy Space Center Oct. 26 to begin final processing. SORCE is equipped with four instruments that will measure variations in solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. The SORCE project is managed by NASA's Goddard Space Flight Center. The instruments on the SORCE spacecraft are built by the Laboratory for Atmospheric and Space Physics (LASP). Launch of SORCE aboard a Pegasus XL rocket is scheduled for mid-December 2002. Launch site is Cape Canaveral Air Force Station, Fla.

KSC-02pd1664

NASA Image and Video Library

2002-10-28

KENNEDY SPACE CENTER, FLA. -- In the Multi-Purpose Processing Facility at KSC, the Solar Radiation and Climate Experiment (SORCE) spacecraft rests in a horizontal position on a workstand after rotation and removal of its outer covering. SORCE arrived at Kennedy Space Center Oct. 26 to begin final processing. SORCE is equipped with four instruments that will measure variations in solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. The SORCE project is managed by NASA's Goddard Space Flight Center. The instruments on the SORCE spacecraft are built by the Laboratory for Atmospheric and Space Physics (LASP). Launch of SORCE aboard a Pegasus XL rocket is scheduled for mid-December 2002. Launch site is Cape Canaveral Air Force Station, Fla.

Optimization of the scan protocols for CT-based material extraction in small animal PET/CT studies

NASA Astrophysics Data System (ADS)

Yang, Ching-Ching; Yu, Jhih-An; Yang, Bang-Hung; Wu, Tung-Hsin

2013-12-01

We investigated the effects of scan protocols on CT-based material extraction to minimize radiation dose while maintaining sufficient image information in small animal studies. The phantom simulation experiments were performed with the high dose (HD), medium dose (MD) and low dose (LD) protocols at 50, 70 and 80 kVp with varying mA s. The reconstructed CT images were segmented based on Hounsfield unit (HU)-physical density (ρ) calibration curves and the dual-energy CT-based (DECT) method. Compared to the (HU;ρ) method performed on CT images acquired with the 80 kVp HD protocol, a 2-fold improvement in segmentation accuracy and a 7.5-fold reduction in radiation dose were observed when the DECT method was performed on CT images acquired with the 50/80 kVp LD protocol, showing the possibility to reduce radiation dose while achieving high segmentation accuracy.

Radiation and Health: A Workshop for Science Educators

NASA Astrophysics Data System (ADS)

Krieger, Kenneth

2010-03-01

This workshop covers nuclear science and technology topics suitable for science teachers to use in grade 4-12 classes. Subjects included are Fundamentals of Radiation, Exposure to natural and man- made Radiation, Cellular Biology and Radiation Effects, Radioactive Waste Management, Health Physics and Radiation Physics, and Career possibilities in Nuclear Technology. Schools of participants will receive a working Geiger Counter. Workshop presenter is a TEA-approved CPE Provider. Limited to 20 participants - 3 hours - Cost 2.00

Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff

NASA Astrophysics Data System (ADS)

Stephens, D. L.; Townsend, L. W.; Miller, J.; Zeitlin, C.; Heilbronn, L.

Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71 st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R 2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R 2 respectively.

Using the FLUKA Monte Carlo Code to Simulate the Interactions of Ionizing Radiation with Matter to Assist and Aid Our Understanding of Ground Based Accelerator Testing, Space Hardware Design, and Secondary Space Radiation Environments

NASA Technical Reports Server (NTRS)

Reddell, Brandon

2015-01-01

Designing hardware to operate in the space radiation environment is a very difficult and costly activity. Ground based particle accelerators can be used to test for exposure to the radiation environment, one species at a time, however, the actual space environment cannot be duplicated because of the range of energies and isotropic nature of space radiation. The FLUKA Monte Carlo code is an integrated physics package based at CERN that has been under development for the last 40+ years and includes the most up-to-date fundamental physics theory and particle physics data. This work presents an overview of FLUKA and how it has been used in conjunction with ground based radiation testing for NASA and improve our understanding of secondary particle environments resulting from the interaction of space radiation with matter.

Preparation of Greenberger-Horne-Zeilinger Entangled States in the Atom-Cavity Systems

NASA Astrophysics Data System (ADS)

Xu, Nan

2018-02-01

We present a new simple scheme for the preparation of Greenberger-Horne-Zeilinger maximally entangled states of two two-level atoms. The distinct feature of the effective Hamiltonian is that there is no energy exchange between the atoms and the cavity.. Thus the scheme is insensitive to the effect of cavity field and the atom radiation.This protocol may be realizable in the realm of current physical experiment.

A final look at LDEF electro-optic systems components

NASA Technical Reports Server (NTRS)

Blue, M. D.

1995-01-01

Postrecovery characteristics of LDEF electro-optic components from the GTRI tray are compared with their prelaunch characteristics and with the characteristics of similar components from related experiments. Components considered here include lasers, light-emitting diodes, semiconducting radiation detectors and arrays, optical substrates, filters, and mirrors, and specialized coatings. Our understanding of the physical effects resulting from low earth orbit are described, and guidelines and recommendations for component and materials choices are presented.

The physics of cellular synthesis, growth and division

NASA Technical Reports Server (NTRS)

Pollard, E. C.

1974-01-01

Three areas of research in NASA'S University Program are described. Primitive terrestrial living cells were studied as a guide to the kind of cells to look for in extraterrestrial life. Experiments in zero gravity conditions are described with emphasis upon effects on small organisms. The effects of ionizing radiation on cells are studied so that it will be possible to predict dosages which can be tolerated by humans with no permanent damage.

Implementation of Remote 3-Dimensional Image Guided Radiation Therapy Quality Assurance for Radiation Therapy Oncology Group Clinical Trials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui Yunfeng; Galvin, James M.; Radiation Therapy Oncology Group, American College of Radiology, Philadelphia, Pennsylvania

2013-01-01

Purpose: To report the process and initial experience of remote credentialing of three-dimensional (3D) image guided radiation therapy (IGRT) as part of the quality assurance (QA) of submitted data for Radiation Therapy Oncology Group (RTOG) clinical trials; and to identify major issues resulting from this process and analyze the review results on patient positioning shifts. Methods and Materials: Image guided radiation therapy datasets including in-room positioning CT scans and daily shifts applied were submitted through the Image Guided Therapy QA Center from institutions for the IGRT credentialing process, as required by various RTOG trials. A centralized virtual environment is establishedmore » at the RTOG Core Laboratory, containing analysis tools and database infrastructure for remote review by the Physics Principal Investigators of each protocol. The appropriateness of IGRT technique and volumetric image registration accuracy were evaluated. Registration accuracy was verified by repeat registration with a third-party registration software system. With the accumulated review results, registration differences between those obtained by the Physics Principal Investigators and from the institutions were analyzed for different imaging sites, shift directions, and imaging modalities. Results: The remote review process was successfully carried out for 87 3D cases (out of 137 total cases, including 2-dimensional and 3D) during 2010. Frequent errors in submitted IGRT data and challenges in the review of image registration for some special cases were identified. Workarounds for these issues were developed. The average differences of registration results between reviewers and institutions ranged between 2 mm and 3 mm. Large discrepancies in the superior-inferior direction were found for megavoltage CT cases, owing to low spatial resolution in this direction for most megavoltage CT cases. Conclusion: This first experience indicated that remote review for 3D IGRT as part of QA for RTOG clinical trials is feasible and effective. The magnitude of registration discrepancy between institution and reviewer was presented, and the major issues were investigated to further improve this remote evaluation process.« less

What Threats to Human Health Does Space Radiation Pose in Orbit

NASA Technical Reports Server (NTRS)

Wu, Honglu; Semones, Eddie; Weyland, Mark; Zapp, Neal; Cucinotta, Francis A.

2011-01-01

The Space Shuttle program spanned more than the entire length of a solar cycle. Investigations aimed towards understanding the health risks of the astronauts from exposures to space radiation involved mostly physical measurements of the dose and the linear energy transfer (LET) spectrum. Measurement of the dose rate on the Shuttle provided invariable new data for different periods of the solar cycle, whereas measurement of the LET spectrum using the tissue equivalent proportional counter (TEPC) produced the most complete mapping of the radiation environment of the low Earth orbits (LEO). Exposures to the Shuttle astronauts were measured by the personal dosimeter worn by the crewmembers. Analysis of over 300 personal dosimeter readings indicated a dependence on the mission duration, the altitude and inclination of the orbit, and the solar cycle, with the crewmembers on the launch and repair of the Hubble telescope receiving the highest doses due to the altitude of the mission. Secondary neutrons inside the Shuttle were determined by recoil protons or with Bonner spheres, and may contribute significantly to the risks of the crewmembers. In addition, the skin dose and the doses received at different organs were compared using a human phantom onboard a Shuttle mission. A number of radiobiology investigations wer e also performed. The biological doses were determined on six astronauts/cosmonauts on long-duration Shuttle/Mir missions and on two crewmembers on a Hubble repair mission by analyzing the damages in the chromosomes of the crewmembers? white blood cells. Several experiments were also conducted to address the question of possible synergistic effects of spaceflight, microgravity in particular, on the repair of radiation-induced DNA damages. The experimental design included exposure of cells before launch, during flight, or after landing. These physical and biological studies were invaluable in predicting the health risks for astronauts on ISS and future exploration missions. Educational Objectives: A group of high school students flew color negative films on tw o Shuttle missions to detect the radiation environment in orbit. This and other experiments onboard of the Shuttle were aimed at educating the general public of the space program.

ReactorHealth Physics operations at the NIST center for neutron research.

PubMed

Johnston, Thomas P

2015-02-01

Performing health physics and radiation safety functions under a special nuclear material license and a research and test reactor license at a major government research and development laboratory encompasses many elements not encountered by industrial, general, or broad scope licenses. This article reviews elements of the health physics and radiation safety program at the NIST Center for Neutron Research, including the early history and discovery of the neutron, applications of neutron research, reactor overview, safety and security of radiation sources and radioactive material, and general health physics procedures. These comprise precautions and control of tritium, training program, neutron beam sample processing, laboratory audits, inventory and leak tests, meter calibration, repair and evaluation, radioactive waste management, and emergency response. In addition, the radiation monitoring systems will be reviewed including confinement building monitoring, ventilation filter radiation monitors, secondary coolant monitors, gaseous fission product monitors, gas monitors, ventilation tritium monitor, and the plant effluent monitor systems.

Fifteen symposia on microdosimetry: implications for modern particle-beam cancer radiotherapy.

PubMed

Wambersie, A; Menzel, H; Gueulette, J; Pihet, P

2015-09-01

The objective of microdosimetry was, and still is, to identify physical descriptions of the initial physical processes of ionising radiation interacting with biological matter which correlate with observed radiobiological effects with a view to improve the understanding of radiobiological mechanisms and effects. The introduction of therapy with particles starting with fast neutrons followed by negative pions, protons and light ions necessitated the application of biological weighting factors for absorbed dose in order to account for differences of the relative biological effectiveness (RBE). Dedicated radiobiological experiments in therapy beams with mammalian cells and with laboratory animals provided sets of RBE values which are used to evaluate empirical 'clinical RBE values'. The combination of such experiments with microdosimetric measurements in identical conditions offered the possibility to establish semi-empirical relationships between microdosimetric parameters and results of RBE studies. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Physical Interpretation of the Schott Energy of An Accelerating Point Charge and the Question of Whether a Uniformly Accelerating Charge Radiates

ERIC Educational Resources Information Center

Rowland, David R.

2010-01-01

A core topic in graduate courses in electrodynamics is the description of radiation from an accelerated charge and the associated radiation reaction. However, contemporary papers still express a diversity of views on the question of whether or not a uniformly accelerating charge radiates suggesting that a complete "physical" understanding of the…

The MoEDAL Experiment at the LHC - a New Light on the Terascale Frontier

NASA Astrophysics Data System (ADS)

Pinfold, J. L.

2015-07-01

MoEDAL is a pioneering experiment designed to search for highly ionizing avatars of new physics such as magnetic monopoles or massive (pseudo-)stable charged particles. Its groundbreaking physics program defines a number of scenarios that yield potentially revolutionary insights into such foundational questions as: are there extra dimensions or new symmetries; what is the mechanism for the generation of mass; does magnetic charge exist; what is the nature of dark matter; and, how did the big-bang develop. MoEDAL's purpose is to meet such far-reaching challenges at the frontier of the field. The innovative MoEDAL detector employs unconventional methodologies tuned to the prospect of discovery physics. The largely passive MoEDAL detector, deployed at Point 8 on the LHC ring, has a dual nature. First, it acts like a giant camera, comprised of nuclear track detectors - analyzed offline by ultra fast scanning microscopes - sensitive only to new physics. Second, it is uniquely able to trap the particle messengers of physics beyond the Standard Model for further study. MoEDAL's radiation environment is monitored by a state-of-the-art real-time TimePix pixel detector array. A new MoEDAL sub-detector to extend MoEDAL's reach to millicharged, minimally ionizing, particles (MMIPs) is under study.

A potent approach for the development of FPGA based DAQ system for HEP experiments

NASA Astrophysics Data System (ADS)

Khan, Shuaib Ahmad; Mitra, Jubin; David, Erno; Kiss, Tivadar; Nayak, Tapan Kumar

2017-10-01

With ever increasing particle beam energies and interaction rates in modern High Energy Physics (HEP) experiments in the present and future accelerator facilities, there has always been the demand for robust Data Acquisition (DAQ) schemes which perform in the harsh radiation environment and handle high data volume. The scheme is required to be flexible enough to adapt to the demands of future detector and electronics upgrades, and at the same time keeping the cost factor in mind. To address these challenges, in the present work, we discuss an efficient DAQ scheme for error resilient, high speed data communication on commercially available state-of-the-art FPGA with optical links. The scheme utilises GigaBit Transceiver (GBT) protocol to establish radiation tolerant communication link between on-detector front-end electronics situated in harsh radiation environment to the back-end Data Processing Unit (DPU) placed in a low radiation zone. The acquired data are reconstructed in DPU which reduces the data volume significantly, and then transmitted to the computing farms through high speed optical links using 10 Gigabit Ethernet (10GbE). In this study, we focus on implementation and testing of GBT protocol and 10GbE links on an Intel FPGA. Results of the measurements of resource utilisation, critical path delays, signal integrity, eye diagram and Bit Error Rate (BER) are presented, which are the indicators for efficient system performance.

Response of biological uv dosimeters to the simulated extraterrestrial uv radiation

NASA Astrophysics Data System (ADS)

Bérces, A.; Rontó, G.; Kerékgyártó, T.; Kovács, G.; Lammer, H.

In the Laboratory polycrystalline uracil thin layer and bacteriophage T7 detectors have been developed for UV dosimetry on the EarthSs surface. Exponential response of the uracil polycrystal has been detected both by absorption spectroscopy and measurements of the refractive index under the influence of terrestrial solar radiation or using UV-C sources. In UV biological dosimetry the UV dose scale is additive starting at a value of zero according to the definition of CIE (Technical Report TC-6-18). The biological dose can be defined by a measured end-effect. In our dosimeters (phage T7 and uracil dosimeter) exposed to natural (terrestrial) UV radiation the proportion of pyrimidin photoproducts among the total photoproducts is smaller than 0.1 and the linear correlation between the biological and physical dose is higher than 0.9. According to the experimental data this linear relationship is often not valid. We observed that UV radiation did not only induce dimerisation but shorter wavelengths caused monomerisation of pyrimidin dimers. Performing the irradiation in oxygen free environment and using a Deuterium lamp as UV source, we could increase monomerisation against dimerisation thus the DNA-based dosimetrySs additivity rule is not fulfilled in these conditions. In this study we will demonstrate those non-linear experiments which constitute the basis of our biological experiments on the International Space Station.

Editorial

NASA Astrophysics Data System (ADS)

Al-Sheikhly, Mohamad; Varca, Gustavo H. C.

2018-02-01

We are very proud and delighted to introduce this special issue of Radiation Physics and Chemistry (RPC). It is indeed the fruit of an outstanding, collective effort by radiation chemists and physicists, as well as radiation processing and nuclear engineers, who presented their research at the 18th International Meeting of Radiation Processing (IMRP) 2016 in Vancouver, Canada. This valuable issue covers a wide range of reported new results in the field of radiation chemistry, physics, and processing. Eminent scientists carefully selected these invited papers, followed by a thorough reviewing process. This issue presents the selected sixteen invited papers. These papers cover fundamental radiation chemistry mechanisms and kinetics, radiation-induced polymerization and kinetics, radiation effects on synthetic and natural polymers, radiation processing control and quality assurances, radiation-induced preservation of food, radiation sterilization, radiation dosimetry, and radiation synthesis of various fabrics for remediation of nuclear isotopes such as cesium.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Langer, Steven H.; Karlin, Ian; Marinak, Marty M.

HYDRA is used to simulate a variety of experiments carried out at the National Ignition Facility (NIF) [4] and other high energy density physics facilities. HYDRA has packages to simulate radiation transfer, atomic physics, hydrodynamics, laser propagation, and a number of other physics effects. HYDRA has over one million lines of code and includes both MPI and thread-level (OpenMP and pthreads) parallelism. This paper measures the performance characteristics of HYDRA using hardware counters on an IBM BlueGene/Q system. We report key ratios such as bytes/instruction and memory bandwidth for several different physics packages. The total number of bytes read andmore » written per time step is also reported. We show that none of the packages which use significant time are memory bandwidth limited on a Blue Gene/Q. HYDRA currently issues very few SIMD instructions. The pressure on memory bandwidth will increase if high levels of SIMD instructions can be achieved.« less

10 CFR 835.901 - Radiation safety training.

Code of Federal Regulations, 2012 CFR

2012-01-01

... DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Radiation Safety Training § 835.901 Radiation safety... radiation exposure; (2) Basic radiological fundamentals and radiation protection concepts; (3) Physical... comply with the documented radiation protection program. (e) Radiation safety training shall be provided...

10 CFR 835.901 - Radiation safety training.

Code of Federal Regulations, 2014 CFR

2014-01-01

... DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Radiation Safety Training § 835.901 Radiation safety... radiation exposure; (2) Basic radiological fundamentals and radiation protection concepts; (3) Physical... comply with the documented radiation protection program. (e) Radiation safety training shall be provided...

10 CFR 835.901 - Radiation safety training.

Code of Federal Regulations, 2013 CFR

2013-01-01

... DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Radiation Safety Training § 835.901 Radiation safety... radiation exposure; (2) Basic radiological fundamentals and radiation protection concepts; (3) Physical... comply with the documented radiation protection program. (e) Radiation safety training shall be provided...

Development of countermeasures for medical problems encountered in space flight.

PubMed

Nicogossian, A E; Rummel, J D; Leveton, L; Teeter, R

1992-01-01

By the turn of this century, long-duration space missions, either in low Earth orbit or for got early planetary missions, will become commonplace. From the physiological standpoint, exposure to the weightless environment results in changes in body function, some of which are adaptive in nature and some of which can be life threatening. Important issues such as environmental health, radiation protection, physical deconditioning, and bone and muscle loss are of concern to life scientists and mission designers. Physical conditioning techniques such as exercise are not sufficient to protect future space travellers. A review of past experience with piloted missions has shown that gradual breakdown in bone and muscle tissue, together with fluid losses, despite a vigorous exercise regimen can ultimately lead to increased evidence of renal stones, musculoskeletal injuries, and bone fractures. Biological effects of radiation can, over long periods of time increase the risk of cancer development. Today, a vigorous program of study on the means to provide a complex exercise regimen to the antigravity muscles and skeleton is under study. Additional evaluation of artificial gravity as a mechanism to counteract bone and muscle deconditioning and cardiovascular asthenia is under study. New radiation methods are being developed. This paper will deal with the results of these studies.

Development of countermeasures for medical problems encountered in space flight

NASA Astrophysics Data System (ADS)

Nicogossian, Arnauld E.; Rummel, John D.; Leveton, Lauren; Teeter, Ron

1992-08-01

By the turn of this century, long-duration space missions, either in low Earth orbit or for got early planetary missions, will become commonplace. From the physiological standpoint, exposure to the weightless environment results in changes in body function, some of which are adaptive in nature and some of which can be life threatening. Important issues such as environmental health, radiation protection, physical deconditioning, and bone and muscle loss are of concern to life scientists and mission designers. Physical conditioning techniques such as exercise are not sufficient to protect future space travellers. A review of past experience with piloted missions has shown that gradual breakdown in bone and muscle tissue, together with fluid losses, despite a vigorous exercise regimen can ultimately lead to increased evidence of renal stones, musculoskeletal injuries, and bone fractures. Biological effects of radiation can, over long periods of time increase the risk of cancer development. Today, a vigorous program of study on the means to provide a complex exercise regimen to the antigravity muscles and skeleton is under study. Additional evaluation of artificial gravity as a mechanism to counteract bone and muscle deconditioning and cardiovascular asthenia is under study. New radiation methods are being developed. This paper will deal with the results of these studies.

Absolute becoming, relational becoming and the arrow of time: Some non-conventional remarks on the relationship between physics and metaphysics

NASA Astrophysics Data System (ADS)

Dorato, Mauro

The literature on the compatibility between the time of our experience-characterized by passage or becoming-and time as is represented within spacetime theories has been affected by a persistent failure to get a clear grasp of the notion of becoming, both in its relation to an ontology of events "spread" in a four-dimensional manifold, and in relation to temporally asymmetric physical processes. In the first part of my paper I try to remedy this situation by offering what I consider a clear and faithful explication of becoming, valid independently of the particular spacetime setting in which we operate. Along the way, I will show why the metaphysical debate between the so-called "presentists" and "eternalists" is completely irrelevant to the question of becoming, as the debate itself is generated by a failure to distinguish between a tensed and a tenseless sense of "existence". After a much needed distinction between absolute and relational becoming, I then show in what sense classical (non-quantum) spacetime physics presupposes both types of becoming, for the simple reason that spacetime physics presupposes an ontology of (timelike-separated) events. As a consequence, not only does it turn out that using physics to try to provide empirical evidence for the existence of becoming amounts to putting the cart before the horses, but also that the order imposed by "the arrow of becoming" is more fundamental than any other physical arrow of time, despite the fact that becoming cannot be used to explain why entropy grows, or retarded electromagnetic radiation prevails versus advanced radiation.

Linearized Flux Evolution (LiFE): A technique for rapidly adapting fluxes from full-physics radiative transfer models

NASA Astrophysics Data System (ADS)

Robinson, Tyler D.; Crisp, David

2018-05-01

Solar and thermal radiation are critical aspects of planetary climate, with gradients in radiative energy fluxes driving heating and cooling. Climate models require that radiative transfer tools be versatile, computationally efficient, and accurate. Here, we describe a technique that uses an accurate full-physics radiative transfer model to generate a set of atmospheric radiative quantities which can be used to linearly adapt radiative flux profiles to changes in the atmospheric and surface state-the Linearized Flux Evolution (LiFE) approach. These radiative quantities describe how each model layer in a plane-parallel atmosphere reflects and transmits light, as well as how the layer generates diffuse radiation by thermal emission and by scattering light from the direct solar beam. By computing derivatives of these layer radiative properties with respect to dynamic elements of the atmospheric state, we can then efficiently adapt the flux profiles computed by the full-physics model to new atmospheric states. We validate the LiFE approach, and then apply this approach to Mars, Earth, and Venus, demonstrating the information contained in the layer radiative properties and their derivatives, as well as how the LiFE approach can be used to determine the thermal structure of radiative and radiative-convective equilibrium states in one-dimensional atmospheric models.

Developing snowflake divertor physics basis in the DIII-D, NSTX and NSTX-U tokamaks aimed at the divertor power exhaust solution [Snowflake divertor experiments in the DIII-D, NSTX and NSTX-U tokamaks aimed at the development of the divertor power exhaust solution

DOE PAGES

Soukhanovskii, V. A.; Allen, S. L.; Fenstermacher, M. E.; ...

2016-06-02

Experimental results from the National Spherical Torus Experiment (NSTX), a medium-size spherical tokamak with a compact divertor, and DIII-D, a large conventional aspect ratio tokamak, demonstrate that the snowflake (SF) divertor configuration may provide a promising solution for mitigating divertor heat loads and target plate erosion compatible with core H-mode confinement in future fusion devices, where the standard radiative divertor solution may be inadequate. In NSTX, where the initial high-power SF experiment were performed, the SF divertor was compatible with H-mode confinement, and led to the destabilization of large ELMs. However, a stable partial detachment of the outer strike pointmore » was also achieved where inter-ELM peak heat flux was reduced by factors 3-5, and peak ELM heat flux was reduced by up to 80% (cf. standard divertor). The DIII-D studies show the SF divertor enables significant power spreading in attached and radiative divertor conditions. Results include: compatibility with the core and pedestal, peak inter-ELM divertor heat flux reduction due to geometry at lower n e, and ELM energy and divertor peak heat flux reduction, especially prominent in radiative D 2-seeded SF divertor, and nearly complete power detachment and broader radiated power distribution in the radiative D 2-seeded SF divertor at P SOL = 3 - 4 MW. A variety of SF configurations can be supported by the divertor coil set in NSTX Upgrade. Edge transport modeling with the multi-fluid edge transport code UEDGE shows that the radiative SF divertor can successfully reduce peak divertor heat flux for the projected P SOL ≃9 MW case. In conclusion, the radiative SF divertor with carbon impurity provides a wider n e operating window, 50% less argon is needed in the impurity-seeded SF configuration to achieve similar q peak reduction factors (cf. standard divertor).« less

Coherent operation of detector systems and their readout electronics in a complex experiment control environment

NASA Astrophysics Data System (ADS)

Koestner, Stefan

2009-09-01

With the increasing size and degree of complexity of today's experiments in high energy physics the required amount of work and complexity to integrate a complete subdetector into an experiment control system is often underestimated. We report here on the layered software structure and protocols used by the LHCb experiment to control its detectors and readout boards. The experiment control system of LHCb is based on the commercial SCADA system PVSS II. Readout boards which are outside the radiation area are accessed via embedded credit card sized PCs which are connected to a large local area network. The SPECS protocol is used for control of the front end electronics. Finite state machines are introduced to facilitate the control of a large number of electronic devices and to model the whole experiment at the level of an expert system.

Validating an operational physical method to compute surface radiation from geostationary satellites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sengupta, Manajit; Dhere, Neelkanth G.; Wohlgemuth, John H.

We developed models to compute global horizontal irradiance (GHI) and direct normal irradiance (DNI) over the last three decades. These models can be classified as empirical or physical based on the approach. Empirical models relate ground-based observations with satellite measurements and use these relations to compute surface radiation. Physical models consider the physics behind the radiation received at the satellite and create retrievals to estimate surface radiation. Furthermore, while empirical methods have been traditionally used for computing surface radiation for the solar energy industry, the advent of faster computing has made operational physical models viable. The Global Solar Insolation Projectmore » (GSIP) is a physical model that computes DNI and GHI using the visible and infrared channel measurements from a weather satellite. GSIP uses a two-stage scheme that first retrieves cloud properties and uses those properties in a radiative transfer model to calculate GHI and DNI. Developed for polar orbiting satellites, GSIP has been adapted to NOAA's Geostationary Operation Environmental Satellite series and can run operationally at high spatial resolutions. Our method holds the possibility of creating high quality datasets of GHI and DNI for use by the solar energy industry. We present an outline of the methodology and results from running the model as well as a validation study using ground-based instruments.« less

The DOSIS -Experiment onboard the Columbus Laboratory of the International Space Station -Overview and first mission results

NASA Astrophysics Data System (ADS)

Reitz, Guenther; Berger, Thomas; Kürner, Christine; Burmeister, Sünke; Hajek, Michael; Bilski, Pawel; Horwacik, Tomasz; Vanhavere, Filip; Spurny, Frantisek; Jadrnickova, Iva; Pálfalvi, József K.; O'Sullivan, Denis; Yasuda, Nakahiro; Uchihori, Yukio; Kitamura, Hisashi; Kodaira, Satoshi; Yukihara, Eduardo; Benton, Eric; Zapp, Neal; Gaza, Ramona; Zhou, Dazhuang; Semones, Edward; Roed, Yvonne; Boehme, Matthias; Haumann, Lutz

Besides the effects of the microgravity environment, and the psychological and psychosocial problems encountered in confined spaces, radiation is the main health detriment for long dura-tion human space missions. The radiation environment encountered in space differs in nature from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones encountered on earth for occupational radiation workers. Accurate knowledge of the physical characteristics of the space radiation field in dependence on the solar activity, the orbital parameters and the different shielding configurations of the International Space Station ISS is therefore needed. The DOSIS (Dose Distribution inside the ISS) experiment, under the project and science lead of DLR, aims for the spatial and tempo-ral measurement of the radiation field parameters inside the European Columbus laboratory onboard the International Space Station. This goal is achieved by applying a combination of passive (Thermo-and Optical luminescence detectors and Nuclear track etch detectors) and active (silicon telescope) radiation detectors. The passive radiation detectors -so called pas-sive detector packages (PDP) are mounted at eleven positions within the Columbus laboratory -aiming for a spatial dose distribution measurement of the absorbed dose, the linear energy transfer spectra and the dose equivalent with an average exposure time of six months. Two active silicon telescopes -so called Dosimetry Telescopes (DOSTEL 1 and DOSTEL 2) together with a Data and Power Unit (DDPU) are mounted within the DOSIS Main Box at a fixed loca-tion beneath the European Physiology Module (EPM) rack. The DOSTEL 1 and DOSTEL 2 detectors are positioned at a 90 angle to each other for a precise measurement of the temporal and spatial variation of the radiation field, especially during crossing of the South Atlantic Anomaly (SAA). The DOSIS hardware was launched with the Space Shuttle Endeavour to the International Space Station on 15 July 2009 and installed by European Astronaut Frank de Winne on 18 July 2009. The first PDP set was downloaded after an exposure time of 124 days in November 2009 and a second PDP set was installed in November 2009. The active part of the instrument suit is working since July 2009. The presentation will give an overview about the DOSIS experiment as well as first results from the passive and active radiation detector measurements. The Austrian activities within this experiment were supported by the Austrian Space Appli-cations Programme (ASAP) of the Federal Ministry for Transport, Innovation and Technology under contract no. 819643. The Polish contribution to this work was supported by the Min-istry of Science and Higher Education, grant No. DWM/N118/ESA/2008. The Hungarian contribution was supported by the ESA PECS grant No. C98066.

International Scientific Conference on "Radiation-Thermal Effects and Processes in Inorganic Materials"

NASA Astrophysics Data System (ADS)

2015-04-01

The International Scientific Conference on "Radiation-Thermal Effects and Processes in Inorganic Materials" is a traditional representative forum devoted to the discussion of fundamental problems of radiation physics and its technical applications. The first nine conferences were held four times in Tomsk, then in Ulan-Ude (Russia), Bishkek (Kyrgyzstan), Tashkent (Uzbekistan), Sharm El Sheikh (Egypt), and the island of Cyprus. The tenth conference was held in Tomsk, Russia. The program of the Conference covers a wide range of technical areas and modern aspects of radiation physics, its applications and related matters. Topics of interest include, but are not limited to: • Physical and chemical phenomena in inorganic materials in radiation, electrical and thermal fields; • Research methods and equipment modification states and properties of materials; • Technologies and equipment for their implementation; • The use of radiation-thermal processes in nanotechnology; • Adjacent to the main theme of the conference issues The conference was attended by leading scientists from countries near and far abroad who work in the field of radiation physics of solid state and of radiation material science. The School-Conference of Young Scientists was held during the conference. The event was held with the financial support of the Russian Foundation for Basic Research, projects No. 14-38-10210 and No. 14-02-20376.

PREFACE: International Scientific Conference on Radiation-Thermal Effects and Processes in Inorganic Materials 2015 (RTEP2015)

NASA Astrophysics Data System (ADS)

2016-02-01

The International Scientific Conference "Radiation-Thermal Effects and Processes in Inorganic Materials" is a traditional representative forum devoted to the discussion of fundamental problems of radiation physics and its technical applications. The first nine conferences were held fourfold in Tomsk, Ulan-Ude (Russia), Bishkek (Kyrgyzstan), Tashkent (Uzbekistan), Sharm El Sheikh (Egypt), the island of Cyprus. The XI conference was held in Tomsk, Russia. The program of the Conference covers a wide range of technical areas and modern aspects of radiation physics, its applications and related matters. Topics of interest include, but are not limited to: • Physical and chemical phenomena in inorganic materials in radiation, electrical and thermal fields; • Research methods and equipment modification states and properties of materials; • Technologies and equipment for their implementation; • The use of radiation-thermal processes in nanotechnology; • Adjacent to the main theme of the conference issues The conference was attended by leading scientists from countries near and far abroad who work in the field of radiation physics of solid state and of radiation material science. The School-Conference of Young Scientists was also held during the conference. The event was held with the financial support of the Russian Foundation for Basic Research, projects No. 15-02-20616.

New calorimeters for space experiments: physics requirements and technological challenges

NASA Astrophysics Data System (ADS)

Marrocchesi, Pier Simone

2015-07-01

Direct measurements of charged cosmic radiation with instruments in Low Earth Orbit (LEO), or flying on balloons above the atmosphere, require the identification of the incident particle, the measurement of its energy and possibly the determination of its sign-of-charge. The latter information can be provided by a magnetic spectrometer together with a measurement of momentum. However, magnetic deflection in space experiments is at present limited to values of the Maximum Detectable Rigidity (MDR) hardly exceeding a few TV. Advanced calorimetric techniques are, at present, the only way to measure charged and neutral radiation at higher energies in the multi-TeV range. Despite their mass limitation, calorimeters may achieve a large geometric factor and provide an adequate proton background rejection factor, taking advantage of a fine granularity and imaging capabilities. In this lecture, after a brief introduction on electromagnetic and hadronic calorimetry, an innovative approach to the design of a space-borne, large acceptance, homogeneous calorimeter for the detection of high energy cosmic rays will be described.

Studies of Coherent Synchrotron Radiation with the Discontinuous Galerkin Method

NASA Astrophysics Data System (ADS)

Bizzozero, David A.

In this thesis, we present methods for integrating Maxwell's equations in Frenet-Serret coordinates in several settings using discontinuous Galerkin (DG) finite element method codes in 1D, 2D, and 3D. We apply these routines to the study of coherent synchrotron radiation, an important topic in accelerator physics. We build upon the published computational work of T. Agoh and D. Zhou in solving Maxwell's equations in the frequency-domain using a paraxial approximation which reduces Maxwell's equations to a Schrodinger-like system. We also evolve Maxwell's equations in the time-domain using a Fourier series decomposition with 2D DG motivated by an experiment performed at the Canadian Light Source. A comparison between theory and experiment has been published (Phys. Rev. Lett. 114, 204801 (2015)). Lastly, we devise a novel approach to integrating Maxwell's equations with 3D DG using a Galilean transformation and demonstrate proof-of-concept. In the above studies, we examine the accuracy, efficiency, and convergence of DG.

Cirrus clouds. I - A cirrus cloud model. II - Numerical experiments on the formation and maintenance of cirrus

NASA Technical Reports Server (NTRS)

Starr, D. OC.; Cox, S. K.

1985-01-01

A simplified cirrus cloud model is presented which may be used to investigate the role of various physical processes in the life cycle of a cirrus cloud. The model is a two-dimensional, time-dependent, Eulerian numerical model where the focus is on cloud-scale processes. Parametrizations are developed to account for phase changes of water, radiative processes, and the effects of microphysical structure on the vertical flux of ice water. The results of a simulation of a thin cirrostratus cloud are given. The results of numerical experiments performed with the model are described in order to demonstrate the important role of cloud-scale processes in determining the cloud properties maintained in response to larger scale forcing. The effects of microphysical composition and radiative processes are considered, as well as their interaction with thermodynamic and dynamic processes within the cloud. It is shown that cirrus clouds operate in an entirely different manner than liquid phase stratiform clouds.

Neutron/ γ-ray digital pulse shape discrimination with organic scintillators

NASA Astrophysics Data System (ADS)

Kaschuck, Y.; Esposito, B.

2005-10-01

Neutrons and γ-rays produce light pulses with different shapes when interacting with organic scintillators. This property is commonly used to distinguish between neutrons (n) and γ-rays ( γ) in mixed n/ γ fields as those encountered in radiation physics experiments. Although analog electronic pulse shape discrimination (PSD) modules have been successfully used for many years, they do not allow data reprocessing and are limited in count rate capability (typically up to 200 kHz). The performance of a n/ γ digital pulse shape discrimination (DPSD) system by means of a commercial 12-bit 200 MSamples/s transient recorder card is investigated here. Three organic scintillators have been studied: stilbene, NE213 and anthracene. The charge comparison method has been used to obtain simultaneous n/ γ discrimination and pulse height analysis. The importance of DPSD for high-intensity radiation field measurements and its advantages with respect to analog PSD are discussed. Based on post-experiment simulations with acquired data, the requirements for fast digitizers to provide DPSD with organic scintillators are also analyzed.

Plasmon-controlled fluorescence: a new paradigm in fluorescence spectroscopy

PubMed Central

Lakowicz, Joseph R.; Ray, Krishanu; Chowdhury, Mustafa; Szmacinski, Henryk; Fu, Yi; Zhang, Jian; Nowaczyk, Kazimierz

2009-01-01

Fluorescence spectroscopy is widely used in biological research. Until recently, essentially all fluorescence experiments were performed using optical energy which has radiated to the far-field. By far-field we mean at least several wavelengths from the fluorophore, but propagating far-field radiation is usually detected at larger macroscopic distances from the sample. In recent years there has been a growing interest in the interactions of fluorophores with metallic surfaces or particles. Near-field interactions are those occurring within a wavelength distance of an excited fluorophore. The spectral properties of fluorophores can be dramatically altered by near-field interactions with the electron clouds present in metals. These interactions modify the emission in ways not seen in classical fluorescence experiments. In this review we provide an intuitive description of the complex physics of plasmons and near-field interactions. Additionally, we summarize the recent work on metal–fluorophore interactions and suggest how these effects will result in new classes of experimental procedures, novel probes, bioassays and devices. PMID:18810279

Accelerator-based techniques for the support of senior-level undergraduate physics laboratories

NASA Astrophysics Data System (ADS)

Williams, J. R.; Clark, J. C.; Isaacs-Smith, T.

2001-07-01

Approximately three years ago, Auburn University replaced its aging Dynamitron accelerator with a new 2MV tandem machine (Pelletron) manufactured by the National Electrostatics Corporation (NEC). This new machine is maintained and operated for the University by Physics Department personnel, and the accelerator supports a wide variety of materials modification/analysis studies. Computer software is available that allows the NEC Pelletron to be operated from a remote location, and an Internet link has been established between the Accelerator Laboratory and the Upper-Level Undergraduate Teaching Laboratory in the Physics Department. Additional software supplied by Canberra Industries has also been used to create a second Internet link that allows live-time data acquisition in the Teaching Laboratory. Our senior-level undergraduates and first-year graduate students perform a number of experiments related to radiation detection and measurement as well as several standard accelerator-based experiments that have been added recently. These laboratory exercises will be described, and the procedures used to establish the Internet links between our Teaching Laboratory and the Accelerator Laboratory will be discussed.

Analyzing non-LTE Kr plasmas produced in high energy density experiments: from the Z machine to the National Ignition Facility

NASA Astrophysics Data System (ADS)

Dasgupta, Arati

2015-11-01

Designing high fluence photon sources above 10 keV are a challenge for High Energy Density plasmas. This has motivated radiation source development investigations of Kr with K-shell energies around 13 keV. Recent pulsed power driven gas-puff experiments on the refurbished Z machine at Sandia have produced intense X-rays in the multi-keV photon energy range. K-shell radiative yields and efficiencies are very high for Ar, but rapidly decrease for higher atomic number (ZA) elements such as Kr. It has been suggested that an optimum exists corresponding to a trade-off between the increase of photon energy for higher ZA elements and the corresponding fall off in radiative power. However the conversion efficiency on NIF, where the drive, energy deposition process, and target dynamics are different, does not fall off with higher ZA as rapidly as on Z. We have developed detailed atomic structure and collisional data for the full K-, L- and partial M-shell of Kr using the Flexible Atomic Code (FAC). Our non-LTE atomic model includes all collisional and recombination processes, including state-specific dielectronic recombination (DR), that significantly affect ionization balance and spectra of Kr plasmas at the temperatures and densities of concern. The model couples ionization physics, radiation production and transport, and magnetohydrodynamics. In this talk, I will give a detailed description of the model and discuss 1D Kr simulations employing a multifrequency radiation transport scheme. Synthetic K- and L-shell spectra will be compared with available experimental data. This talk will analyze experimental data indicative of the differences between Z and NIF experimental data and discuss how they affect the K-shell radiative output of Kr plasma. Work supported by DOE/NNSA.

Hawking-like radiation does not require a trapped region.

PubMed

Barceló, Carlos; Liberati, Stefano; Sonego, Sebastiano; Visser, Matt

2006-10-27

We discuss the issue of quasiparticle production by "analogue black holes" with particular attention paid to the possibility of reproducing Hawking radiation in a laboratory. By constructing simple geometric acoustic models, we obtain a somewhat unexpected result: We show that, in order to obtain a stationary and Planckian emission of quasiparticles, it is not necessary to create a trapped region in the acoustic spacetime (corresponding to a supersonic regime in the fluid flow). It is sufficient to set up a dynamically changing flow asymptotically approaching a sonic regime with sufficient rapidity in laboratory time. This result is generic to curved-space quantum field theory, the "analogue spacetimes" we consider providing a guide to physical intuition, and a possible route to laboratory experiments.

Human radiation studies: Remembering the early years. Oral history of biophysicist Cornelius A. Tobias, Ph.D., January 16, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-07-01

Dr. Cornelius A. Tobias was interviewed by representatives of US DOE Office of Human Radiation Experiments (OHRE). He was chosen for this interview because of his extensive biophysics and medical physics research activities while he was employed by the University of California, Berkeley and San Francisco and at the Donner Laboratory. He discusses his involvement in wartime studies of effects of high altitude on aviators, carbon monoxide with radioactive tracers, blood studies with radioactive iron, human use committees, heavy-ion research with the Bevatron, boron isotope research, classified research involving human subjects, heavy-particle radiography, heavy- particle beams and medical research, andmore » pituitary irradiation studies,.« less

Position sensitive detection of nuclear radiation mediated by non equilibrium phonons at low temperatures

NASA Astrophysics Data System (ADS)

Pröbst, F.; Peterreins, Th.; Feilitzsch, F. v.; Kraus, H.

1990-03-01

Many experiments in nuclear and particle physics would benefit from the development of a device capable of detecting non-ionizing events with a low energy threshold. In this context, we report on experimental tests of a detector based on the registration of nonequilibrium phonons. The device is composed of a silicon single crystal (size: 20×10×3 mm 3) and of an array of superconducting tunnel junctions evaporated onto the surface of the crystal. The junctions serve as sensors for phonons created by absorption of nuclear radiation in the crystal. We show how pulse height analysis and the investigation of time differences between correlated pulses in different junctions can be used to obtain information about the point of absorption.

Anthropogenic Space Weather

NASA Astrophysics Data System (ADS)

Gombosi, T. I.; Baker, D. N.; Balogh, A.; Erickson, P. J.; Huba, J. D.; Lanzerotti, L. J.

2017-11-01

Anthropogenic effects on the space environment started in the late 19th century and reached their peak in the 1960s when high-altitude nuclear explosions were carried out by the USA and the Soviet Union. These explosions created artificial radiation belts near Earth that resulted in major damages to several satellites. Another, unexpected impact of the high-altitude nuclear tests was the electromagnetic pulse (EMP) that can have devastating effects over a large geographic area (as large as the continental United States). Other anthropogenic impacts on the space environment include chemical release experiments, high-frequency wave heating of the ionosphere and the interaction of VLF waves with the radiation belts. This paper reviews the fundamental physical process behind these phenomena and discusses the observations of their impacts.

Impact Flash Physics: Modeling and Comparisons With Experimental Results

NASA Astrophysics Data System (ADS)

Rainey, E.; Stickle, A. M.; Ernst, C. M.; Schultz, P. H.; Mehta, N. L.; Brown, R. C.; Swaminathan, P. K.; Michaelis, C. H.; Erlandson, R. E.

2015-12-01

Hypervelocity impacts frequently generate an observable "flash" of light with two components: a short-duration spike due to emissions from vaporized material, and a long-duration peak due to thermal emissions from expanding hot debris. The intensity and duration of these peaks depend on the impact velocity, angle, and the target and projectile mass and composition. Thus remote sensing measurements of planetary impact flashes have the potential to constrain the properties of impacting meteors and improve our understanding of impact flux and cratering processes. Interpreting impact flash measurements requires a thorough understanding of how flash characteristics correlate with impact conditions. Because planetary-scale impacts cannot be replicated in the laboratory, numerical simulations are needed to provide this insight for the solar system. Computational hydrocodes can produce detailed simulations of the impact process, but they lack the radiation physics required to model the optical flash. The Johns Hopkins University Applied Physics Laboratory (APL) developed a model to calculate the optical signature from the hot debris cloud produced by an impact. While the phenomenology of the optical signature is understood, the details required to accurately model it are complicated by uncertainties in material and optical properties and the simplifications required to numerically model radiation from large-scale impacts. Comparisons with laboratory impact experiments allow us to validate our approach and to draw insight regarding processes that occur at all scales in impact events, such as melt generation. We used Sandia National Lab's CTH shock physics hydrocode along with the optical signature model developed at APL to compare with a series of laboratory experiments conducted at the NASA Ames Vertical Gun Range. The experiments used Pyrex projectiles to impact pumice powder targets with velocities ranging from 1 to 6 km/s at angles of 30 and 90 degrees with respect to horizontal. High-speed radiometer measurements were made of the time-dependent impact flash at wavelengths of 350-1100 nm. We will present comparisons between these measurements and the output of APL's model. The results of this validation allow us to determine basic relationships between observed optical signatures and impact conditions.

The experience of relocation for specialist treatment for Indigenous women diagnosed with vulvar cancer in East Arnhem Land.

PubMed

McGrath, Pam; Rawson, Nicole

2013-01-01

Vulvar cancer is a serious condition that requires a range of specialist treatments including surgery, chemotherapy, and radiation. In Australia, such treatments are only available in major metropolitan hospitals. Thus, women diagnosed with this condition in rural and remote areas must relocate to the metropolitan specialist centers for treatment. The focus of this article is on the experience of relocation for specialist care for Indigenous women diagnosed with vulvar cancer from East Arnhem Land, Northern Territory, Australia. The findings presented in this article explore a range of issues that affect the experience of relocation such as community concerns, cultural distress, loneliness, fear, worry, and physical concerns associated with the condition.

Analysis of Radiation Impact on White Mice through Radiation Dose Mapping in Medical Physics Laboratory

NASA Astrophysics Data System (ADS)

Sutikno, Madnasri; Susilo; Arya Wijayanti, Riza

2016-08-01

A study about X-ray radiation impact on the white mice through radiation dose mapping in Medical Physic Laboratory is already done. The purpose of this research is to determine the minimum distance of radiologist to X-ray instrument through treatment on the white mice. The radiation exposure doses are measured on the some points in the distance from radiation source between 30 cm up to 80 with interval of 30 cm. The impact of radiation exposure on the white mice and the effects of radiation measurement in different directions are investigated. It is founded that minimum distance of radiation worker to radiation source is 180 cm and X-ray has decreased leukocyte number and haemoglobin and has increased thrombocyte number in the blood of white mice.

Methods of teaching the physics of climate change in undergraduate physics courses

NASA Astrophysics Data System (ADS)

Sadler, Michael

2015-04-01

Although anthropogenic climate change is generally accepted in the scientific community, there is considerable skepticism among the general population and, therefore, in undergraduate students of all majors. Students are often asked by their peers, family members, and others, whether they ``believe'' climate change is occurring and what should be done about it (if anything). I will present my experiences and recommendations for teaching the physics of climate change to both physics and non-science majors. For non-science majors, the basic approach is to try to develop an appreciation for the scientific method (particularly peer-reviewed research) in a course on energy and the environment. For physics majors, the pertinent material is normally covered in their undergraduate courses in modern physics and thermodynamics. Nevertheless, it helps to review the basics, e.g. introductory quantum mechanics (discrete energy levels of atomic systems), molecular spectroscopy, and blackbody radiation. I have done this in a separate elective topics course, titled ``Physics of Climate Change,'' to help the students see how their knowledge gives them insight into a topic that is very volatile (socially and politically).

[Staffing levels in medical radiation physics in radiation therapy in Germany. Summary of a questionnaire].

PubMed

Leetz, Hans-Karl; Eipper, Hermann Hans; Gfirtner, Hans; Schneider, Peter; Welker, Klaus

2003-10-01

To get a general idea of the actual staffing level situation in medical radiation physics in 1999 a survey was carried out by the task-group "Personalbedarf" of Deutsche Gesellschaft für Medizinische Physik (DGMP) among all DGMP-members who are active in this field. Main components for equipment and activities are defined in Report 8 and 10 of DGMP for staffing requirements in medical radiation physics. 322 forms were sent out, 173 of them have been evaluated. From the answers regarding equipment and activities numbers for staff are calculated by the methods given in Report 8 and 10 for this spot check target and compared with effective staffing levels. The data of the spot check are then extrapolated on total Germany. The result is a calculated deficit of 865 medical physicists for the whole physics staff, 166 of them in radiation therapy. From the age distribution of DGMP-members and the calculated deficit resulted a training capacity of about 100 medical physicists at all per year (19 in radiation therapy) if the deficit shall be cut back in 10 years.

Convective Aggregation, Climate Sensitivity, and the Importance of Radiation Physics in Weather and Climate

NASA Astrophysics Data System (ADS)

Emanuel, K.

2015-12-01

Since the revolutionary work of Vilhelm Bjerknes, Jule Charney, and Eric Eady, geophysical fluid dynamics has dominated weather research and continues to play an important in climate dynamics. Although the physics of radiative transfer is central to understanding climate, it has played a far smaller role in weather research and is given only rudimentary attention in most educational programs in meteorology. Yet key contemporary problems in atmospheric science, such as the Madden-Julian Oscillation and the self-aggregation of moist convection, do not appear to have been solved by approaches based strictly on fluid dynamics and moist adiabatic thermodynamics. Here I will argue that many outstanding problems in meteorology and climate science involve a nontrivial coupling of circulation and radiation physics. In particular, the phenomenon of self-aggregation of moist convection depends on the interaction of radiation with time-varying water vapor and clouds, with strong implications for such diverse problems as the Madden-Julian Oscillation, tropical cyclones, and the relative insensitivity of tropical climate to radiative forcing. This argues for an augmentation of radiative transfer physics in graduate curricula in atmospheric sciences.

G. E. M. Jauncey and the Compton Effect

NASA Astrophysics Data System (ADS)

Jenkin, John

In late 1922 Arthur Holly Compton (1892-1962) discovered that an X-ray quantum of radiation undergoes a discrete change in wavelength when it experiences a billiard-ball collision with a single atomic electron, a phenomenon that became known as the Compton effect and for which he shared the Nobel Prize in Physics for 1927. But for more than five years before he made his discovery, Compton had analyzed X-ray scattering in terms of classical electrodynamics. I suggest that his colleague at Washington University in St. Louis, G. E. M. Jauncey (1888-1947), helped materially to persuade him to embrace the quantum interpretation of his X-ray scattering experiments.

EDITORIAL: Focus on Heavy Ions in Biophysics and Medical Physics FOCUS ON HEAVY IONS IN BIOPHYSICS AND MEDICAL PHYSICS

NASA Astrophysics Data System (ADS)

Durante, Marco

2008-07-01

Interest in energetic heavy ions is rapidly increasing in the field of biomedicine. Heavy ions are normally excluded from radiation protection, because they are not normally experienced by humans on Earth. However, knowledge of heavy ion biophysics is necessary in two fields: charged particle cancer therapy (hadrontherapy), and radiation protection in space missions. The possibility to cure tumours using accelerated heavy charged particles was first tested in Berkeley in the sixties, but results were not satisfactory. However, about 15 years ago therapy with carbon ions was resumed first in Japan and then in Europe. Heavy ions are preferable to photons for both physical and biological characteristics: the Bragg peak and limited lateral diffusion ensure a conformal dose distribution, while the high relative biological effectiveness and low oxygen enhancement ration in the Bragg peak region make the beam very effective in treating radioresistant and hypoxic tumours. Recent results coming from the National Institute of Radiological Sciences in Chiba (see the paper by Dr Tsujii and co-workers in this issue) and GSI (Germany) provide strong clinical evidence that heavy ions are indeed an extremely effective weapon in the fight against cancer. However, more research is needed in the field, especially on optimization of the treatment planning and risk of late effects in normal tissue, including secondary cancers. On the other hand, high-energy heavy ions are present in galactic cosmic radiation and, although they are rare as compared to protons, they give a major contribution in terms of equivalent dose to the crews of manned space exploratory-class missions. Exploration of the Solar System is now the main goal of the space program, and the risk caused by exposure to galactic cosmic radiation is considered a serious hindrance toward this goal, because of the high uncertainty on late effects of energetic heavy nuclei, and the lack of effective countermeasures. Risks include carcinogenesis, late degenerative tissue effects (including damage to the central nervous system), and hereditary effects. For these studies, microbeams represent an essential tool, considering that in space each cell in the human body will not experience more than one heavy-ion traversal. Both NASA and ESA are investing important resources in ground-based space radiation research programs, to reduce risk uncertainty and to develop countermeasures. For both cancer therapy and space radiation protection a better understanding of the effects of energetic heavy ions is needed. Physics should be improved, especially the measurements of nuclear fragmentation cross-sections, and the transport calculations. Biological effects need to be studied in greater detail, and clearly only understanding the mechanisms of heavy-ion induced biological damage will reduce the uncertainty on late effects in humans. This focus issue of New Journal of Physics aims to provide the state-of-the-art of the biophysics of energetic heavy ions and to highlight the areas where more research is urgently needed for therapy and the space program. Focus on Heavy Ions in Biophysics and Medical Physics Contents Heavy ion microprobes: a unique tool for bystander research and other radiobiological applications K O Voss, C Fournier and G Taucher-Scholz Heavy ions light flashes and brain functions: recent observations at accelerators and in spaceflight L Narici Clinical advantages of carbon-ion radiotherapy Hirohiko Tsujii, Tadashi Kamada, Masayuki Baba, Hiroshi Tsuji, Hirotoshi Kato, Shingo Kato, Shigeru Yamada, Shigeo Yasuda, Takeshi Yanagi, Hiroyuki Kato, Ryusuke Hara, Naotaka Yamamoto and Junetsu Mizoe Heavy-ion effects: from track structure to DNA and chromosome damage F Ballarini, D Alloni, A Facoetti and A Ottolenghi Shielding experiments with high-energy heavy ions for spaceflight applications C Zeitlin, S Guetersloh, L Heilbronn, J Miller, N Elkhayari, A Empl, M LeBourgeois, B W Mayes, L Pinsky, M Christl and E Kuznetsov Heavy charged particles in radiation biology and biophysics H Nikjoo, S Uehara, D Emfietzoglou and A Brahme Impact of track structure calculations on biological treatment planning in ion radiotherapy Thilo Elsässer, Richard Cunrath, Michael Krämer and Michael Scholz The physical basis for the biological action of heavy ions Jürgen Kiefer Secondary beam fragments produced by 200 MeV u-1 12C ions in water and their dose contributions in carbon ion radiotherapy K Gunzert-Marx, H Iwase, D Schardt and R S Simon

Synchrotron radiation based beam diagnostics at the Fermilab Tevatron

DOE PAGES

Thurman-Keup, R.; Cheung, H. W. K.; Hahn, A.; ...

2011-09-16

Synchrotron radiation has been used for many years as a beam diagnostic at electron accelerators. It is not normally associated with proton accelerators as the intensity of the radiation is too weak to make detection practical. Therefore, if one utilizes the radiation originating near the edge of a bending magnet, or from a short magnet, the rapidly changing magnetic field serves to enhance the wavelengths shorter than the cutoff wavelength, which for more recent high energy proton accelerators such as Fermilab's Tevatron, tends to be visible light. This paper discusses the implementation at the Tevatron of two devices. A transversemore » beam profile monitor images the synchrotron radiation coming from the proton and antiproton beams separately and provides profile data for each bunch. A second monitor measures the low-level intensity of beam in the abort gaps which poses a danger to both the accelerator's superconducting magnets and the silicon detectors of the high energy physics experiments. Comparisons of measurements from the profile monitor to measurements from the flying wire profile systems are presented as are a number of examples of the application of the profile and abort gap intensity measurements to the modelling of Tevatron beam dynamics.« less

An Assessment of ECMWF Analyses and Model Forecasts over the North Slope of Alaska Using Observations from the ARM Mixed-Phase Arctic Cloud Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Shaocheng; Klein, Stephen A.; Yio, J. John

2006-03-11

European Centre for Medium-Range Weather Forecasts (ECMWF) analysis and model forecast data are evaluated using observations collected during the Atmospheric Radiation Measurement (ARM) October 2004 Mixed-Phase Arctic Cloud Experiment (M-PACE) at its North Slope of Alaska (NSA) site. It is shown that the ECMWF analysis reasonably represents the dynamic and thermodynamic structures of the large-scale systems that affected the NSA during M-PACE. The model-analyzed near-surface horizontal winds, temperature, and relative humidity also agree well with the M-PACE surface measurements. Given the well-represented large-scale fields, the model shows overall good skill in predicting various cloud types observed during M-PACE; however, themore » physical properties of single-layer boundary layer clouds are in substantial error. At these times, the model substantially underestimates the liquid water path in these clouds, with the concomitant result that the model largely underpredicts the downwelling longwave radiation at the surface and overpredicts the outgoing longwave radiation at the top of the atmosphere. The model also overestimates the net surface shortwave radiation, mainly because of the underestimation of the surface albedo. The problem in the surface albedo is primarily associated with errors in the surface snow prediction. Principally because of the underestimation of the surface downwelling longwave radiation at the times of single-layer boundary layer clouds, the model shows a much larger energy loss (-20.9 W m-2) than the observation (-9.6 W m-2) at the surface during the M-PACE period.« less

[Personnel requirements of medical radiation physics in radiotherapy in comparison to the current guidelines "radiation protection in medicine" : Special consideration of intensity-modulated radiation therapy].

PubMed

Leetz, H-K; Eipper, H H; Gfirtner, H; Schneider, P; Welker, K

2014-08-01

In 1994 and 1998 reports on staffing levels in medical radiation physics for radiation therapy were published by the "Deutsche Gesellschaft für Medizinische Physik" (DGMP, German Society for Medical Physics). Because of the technical and methodological progress, changes in recommended qualifications of staff and new governmental regulations, it was necessary to establish new staffing levels. The data were derived from a new survey in clinics. Some of the previously established results from the old reports were adapted to the new conditions by conversion.The staffing requirements were normalized to main components as in the earlier reports resulting in a simple method for calculation of staffing levels. The results were compared with the requirements in the "Richtlinie Strahlenschutz in der Medizin" (guidelines on radiation protection in medicine) and showed satisfactory agreement.

Space Radiation Risk Assessment

NASA Astrophysics Data System (ADS)

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

Development of a Remote Sensing and Microgravity Student GAS Payload

NASA Technical Reports Server (NTRS)

Branly, Rolando; Ritter, Joe; Friedfeld, Robert; Ackerman, Eric; Carruthers, Carl; Faranda, Jon

1999-01-01

The G-781 Terrestrial and Atmospheric Multi-Spectral Explorer payload (TAMSE) is the result of an educational partnership between Broward and Brevard Community Colleges with the Association of Small Payload Researchers (ASPR) and the Florida Space Institute, University of Central Florida. The effort focuses on flying nine experiments, including three earth viewing remote sensing experiments, three microgravity experiments involving crystal growth, and three radiation measurement experiments. The G-781 science team, composed of both student and faculty members, has been working on this payload since 1995. The dream of flying the first Florida educational GAS experiment led to the flight of a passive Radiation dosimetry experiment on STS-91 (ASPR-GraDEx-I), which will be reflown as part of TAMSE. This project has lead to the development of a mature space science program within the schools. Many students have been positively touched by direct involvement with NASA and the GAS program as well as with other flight programs e.g. the KC-135 flight program. Several students have changed majors, and selected physics, engineering, and other science career paths as a result of the experience. The importance of interdisciplinary training is fundamental to this payload and to the teaching of the natural sciences. These innovative student oriented projects will payoff not only in new science data, but also in accomplishing training for the next generation of environmental and space scientists. The details the TAMSE payload design are presented in this paper.

Higher energy: is it necessary, is it worth the cost for radiation oncology?

PubMed

Das, I J; Kase, K R

1992-01-01

The physical characteristics of the interactions of megavoltage photons and electrons with matter provide distinct advantages, relative to low-energy (orthovoltage) x rays, that lead to better radiation dose distributions in patients. Use of these high-energy radiations has resulted in better patient care, which has been reflected in improved radiation treatment outcome in recent years. But, as the desire for higher energy radiation beams increases, it becomes important to determine whether the physical characteristics that make megavoltage beams beneficial continue to provide a net advantage. It is demonstrated that, in fact, there is an energy range from 4 to 15 MV for photons and 4 to 20 MeV for electrons that is optimally suited for the treatment of cancer in humans. Radiation beams that exceed these maximum energies were found to add no advantage. This is because the costs (price of unit, installation, maintenance, shielding for neutron and photons) are not justified by either improved physical characteristics of the radiation (penetration, skin sparing, dose distribution) or treatment outcome. In fact, for photon beams some physical characteristics result in less desirable dose distributions, less accurate dosimetry, and increased safety problems as the energy increases for example, increasingly diffuse beam edges, loss of electron equilibrium, uncertainty in dose perturbations at interfaces, increased neutron contamination, and potential for higher personnel dose. The special features that make electron beams useful at lower energies, for example, skin sparing and small penetration, are lost at high energies. These physical factors are analyzed together with the economic factors related to radiation therapy patient care using megavoltage beams.

A radiation and energy budget algorithm for forest canopies

NASA Astrophysics Data System (ADS)

Tunick, A.

2006-01-01

Previously, it was shown that a one-dimensional, physics-based (conservation-law) computer model can provide a useful mathematical representation of the wind flow, temperatures, and turbulence inside and above a uniform forest stand. A key element of this calculation was a radiation and energy budget algorithm (implemented to predict the heat source). However, to keep the earlier publication brief, a full description of the radiation and energy budget algorithm was not given. Hence, this paper presents our equation set for calculating the incoming total radiation at the canopy top as well as the transmission, reflection, absorption, and emission of the solar flux through a forest stand. In addition, example model output is presented from three interesting numerical experiments, which were conducted to simulate the canopy microclimate for a forest stand that borders the Blossom Point Field Test Facility (located near La Plata, Maryland along the Potomac River). It is anticipated that the current numerical study will be useful to researchers and experimental planners who will be collecting acoustic and meteorological data at the Blossom Point Facility in the near future.

A 0.18 μm CMOS low-power radiation sensor for asynchronous event-driven UWB wireless transmission

NASA Astrophysics Data System (ADS)

Bastianini, S.; Crepaldi, M.; Demarchi, D.; Gabrielli, A.; Lolli, M.; Margotti, A.; Villani, G.; Zhang, Z.; Zoccoli, G.

2013-12-01

The paper describes the design of a readout element, proposed as a radiation monitor, which implements an embedded sensor based on a floating-gate transistor. The paper shows the design of a microelectronic circuit composed of a sensor, an oscillator, a modulator, a transmitter and an integrated antenna. A prototype chip has recently been fabricated and tested exploiting a commercial 180 nm, four metal CMOS technology. Simulation results of the entire behavior of the circuit before submission are presented along with some measurements of the actual chip response. In addition, preliminary tests of the performance of the Ultra-Wide Band transmission via the integrated antenna are summarized. As the complete chip prototype area is less than 1 mm2, the chip fits a large variety of applications, from spot radiation monitoring systems in medicine to punctual measurements of radiation level in High-Energy Physics experiments. A sensitivity of 1 mV/rad was estimated within an absorbed dose range up to 10 krad and a total power consumption of about 165 μW.

Space experiment "Rad Gene"-report 1; p53-Dependent gene expression in human cultured cells exposed to space environment

NASA Astrophysics Data System (ADS)

Takahashi, Akihisa; Ohnishi, Takeo; Suzuki, Hiromi; Omori, Katsunori; Seki, Masaya; Hashizume, Toko; Shimazu, Toru; Ishioka, Noriaki

The space environment contains two major biologically significant influences: space radiations and microgravity. A p53 tumor suppressor protein plays a role as a guardian of the genome through the activity of p53-centered signal transduction pathways. The aim of this study was to clarify the biological effects of space radiations, microgravity and a space environment on the gene and protein expression of p53-dependent regulated genes. Space experiments were performed with two human cultured lymphoblastoid cell lines: one cells line (TSCE5) bears a wild-type p53 gene status, and another cells line (WTK1) bears a mutated p53 gene status. Un-der one gravity or microgravity condition, the cells were grown in the cell biology experimental facility (CBEF) of the International Space Station (ISS) for 8 days without experiencing the stress during launching and landing because the cells were frozen during these periods. Ground control samples also were cultured for 8 days in the CBEF on the ground during the same periods as space flight. Gene and protein expression was analyzed by using DNA chip (a 44k whole human genome microarray, Agilent Technologies Inc.) and protein chip (PanoramaTM Ab MicroArray, Sigma-Aldrich Co.), respectively. In addition, we analyzed the gene expression in cultured cells after space flight during 133 days with frozen condition. We report the results and discussion from the viewpoint of the functions of the up-regulated and down-regulated genes after an exposure to space radiations and/or microgravity. The initial goal of this space experiment was completely achieved. It is expected that data from this type of work will be helpful in designing physical protection from the deleterious effects of space radiations during long term stays in space.

Photoionized Plasma and Opacity Experiments on the Z Machine

NASA Astrophysics Data System (ADS)

Bailey, James

2008-04-01

Laboratory experiments at Z use high energy density to create plasma conditions similar to extreme astrophysical environments, including stellar interiors and accretion powered objects. The importance of radiation unifies these topics, even though the plasmas involved are very different. Understanding stellar interiors requires knowledge of radiation transport in dense, hot, collision-dominated plasma. A Z x-ray source was used to measure iron plasma transmission at 156 eV electron temperature, 2x higher than in prior work. The data provide the first experimental tests of absorption features critical for stellar interior opacity models and may provide insight into whether the present discrepancy between solar models and helioseismology originates in opacity model deficiencies or in some other aspect of the solar model. In contrast, accretion physics requires interpretation of x-ray spectra from lower density photoionization-dominated plasma. Exploiting astrophysical spectra requires a spectral model that connects the observations with a model that describes the overall picture of the astrophysical object. However, photoionized plasma spectral models are largely untested. Z-pinch radiation was used to create photoionized iron and neon plasmas with photoionization parameter 5-25 erg cm /s. Comparisons with the data improve x-ray photoionization models and promote more accurate interpretation of spectra acquired with astrophysical observatories. The prospects for new experiments at the higher radiation powers provided by the recently upgraded Z facility will be described.* In collaboration with scientists from CEA, LANL, LLNL, Oxford, Prism, Queens University, Swarthmore College, U. Nevada Reno, and Sandia ++Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

The shock/shear platform for planar radiation-hydrodynamics experiments on the National Ignition Facility

DOE PAGES

Doss, F. W.; Kline, J. L.; Flippo, K. A.; ...

2015-04-17

An indirectly-driven shock tube experiment fielded on the National Ignition Facility (NIF) was used to create a high-energy-density hydrodynamics platform at unprecedented scale. Scaling up a shear-induced mixing experiment previously fielded at OMEGA, the NIF shear platform drives 130 μm/ns shocks into a CH foam-filled shock tube (~ 60 mg/cc) with interior dimensions of 1.5 mm diameter and 5 mm length. The pulse-shaping capabilities of the NIF are used to extend the drive for >10 ns, and the large interior tube volumes are used to isolate physics-altering edge effects from the region of interest. The scaling of the experiment tomore » the NIF allows for considerable improvement in maximum driving time of hydrodynamics, in fidelity of physics under examination, and in diagnostic clarity. Details of the experimental platform and post-shot simulations used in the analysis of the platform-qualifying data are presented. Hydrodynamic scaling is used to compare shear data from OMEGA with that from NIF, suggesting a possible change in the dimensionality of the instability at late times from one platform to the other.« less

High Resolution Integrated Hohlraum-Capsule Simulations for Virtual NIF Ignition Campaign

NASA Astrophysics Data System (ADS)

Jones, O. S.; Marinak, M. M.; Cerjan, C. J.; Clark, D. S.; Edwards, M. J.; Haan, S. W.; Langer, S. H.; Salmonson, J. D.

2009-11-01

We have undertaken a virtual campaign to assess the viability of the sequence of NIF experiments planned for 2010 that will experimentally tune the shock timing, symmetry, and ablator thickness of a cryogenic ignition capsule prior to the first ignition attempt. The virtual campaign consists of two teams. The ``red team'' creates realistic simulated diagnostic data for a given experiment from the output of a detailed radiation hydrodynamics calculation that has physics models that have been altered in a way that is consistent with probable physics uncertainties. The ``blue team'' executes a series of virtual experiments and interprets the simulated diagnostic data from those virtual experiments. To support this effort we have developed a capability to do very high spatial resolution integrated hohlraum-capsule simulations using the Hydra code. Surface perturbations for all ablator layer surfaces and the DT ice layer are calculated explicitly through mode 30. The effects of the fill tube, cracks in the ice layer, and defects in the ablator are included in models extracted from higher resolution calculations. Very high wave number mix is included through a mix model. We will show results from these calculations in the context of the ongoing virtual campaign.

Laser absorption, power transfer, and radiation symmetry during the first shock of inertial confinement fusion gas-filled hohlraum experiments

NASA Astrophysics Data System (ADS)

Pak, A.; Dewald, E. L.; Landen, O. L.; Milovich, J.; Strozzi, D. J.; Berzak Hopkins, L. F.; Bradley, D. K.; Divol, L.; Ho, D. D.; MacKinnon, A. J.; Meezan, N. B.; Michel, P.; Moody, J. D.; Moore, A. S.; Schneider, M. B.; Town, R. P. J.; Hsing, W. W.; Edwards, M. J.

2015-12-01

Temporally resolved measurements of the hohlraum radiation flux asymmetry incident onto a bismuth coated surrogate capsule have been made over the first two nanoseconds of ignition relevant laser pulses. Specifically, we study the P2 asymmetry of the incoming flux as a function of cone fraction, defined as the inner-to-total laser beam power ratio, for a variety of hohlraums with different scales and gas fills. This work was performed to understand the relevance of recent experiments, conducted in new reduced-scale neopentane gas filled hohlraums, to full scale helium filled ignition targets. Experimental measurements, matched by 3D view factor calculations, are used to infer differences in symmetry, relative beam absorption, and cross beam energy transfer (CBET), employing an analytic model. Despite differences in hohlraum dimensions and gas fill, as well as in laser beam pointing and power, we find that laser absorption, CBET, and the cone fraction, at which a symmetric flux is achieved, are similar to within 25% between experiments conducted in the reduced and full scale hohlraums. This work demonstrates a close surrogacy in the dynamics during the first shock between reduced-scale and full scale implosion experiments and is an important step in enabling the increased rate of study for physics associated with inertial confinement fusion.

Medical physics: some recollections in diagnostic X-ray imaging and therapeutic radiology.

PubMed

Gray, J E; Orton, C G

2000-12-01

Medical physics has changed dramatically since 1895. There was a period of slow evolutionary change during the first 70 years after Roentgen's discovery of x rays. With the advent of the computer, however, both diagnostic and therapeutic radiology have undergone rapid growth and changes. Technologic advances such as computed tomography and magnetic resonance imaging in diagnostic imaging and three-dimensional treatment planning systems, stereotactic radiosurgery, and intensity modulated radiation therapy in radiation oncology have resulted in substantial changes in medical physics. These advances have improved diagnostic imaging and radiation therapy while expanding the need for better educated and experienced medical physics staff.

In situ photoacoustic characterization for porous silicon growing: Detection principles

NASA Astrophysics Data System (ADS)

Ramirez-Gutierrez, C. F.; Castaño-Yepes, J. D.; Rodriguez-García, M. E.

2016-05-01

There are a few methodologies for monitoring the in-situ formation of Porous Silicon (PS). One of the methodologies is photoacoustic. Previous works that reported the use of photoacoustic to study the PS formation do not provide the physical explanation of the origin of the signal. In this paper, a physical explanation of the origin of the photoacoustic signal during the PS etching is provided. The incident modulated radiation and changes in the reflectance are taken as thermal sources. In this paper, a useful methodology is proposed to determine the etching rate, porosity, and refractive index of a PS film by the determination of the sample thickness, using scanning electron microscopy images. This method was developed by carrying out two different experiments using the same anodization conditions. The first experiment consisted of growth of the samples with different etching times to prove the periodicity of the photoacoustic signal, while the second one considered the growth samples using three different wavelengths that are correlated with the period of the photoacoustic signal. The last experiment showed that the period of the photoacoustic signal is proportional to the laser wavelength.

Low-background Gamma Spectroscopy at Sanford Underground Laboratory

NASA Astrophysics Data System (ADS)

Chiller, Christopher; Alanson, Angela; Mei, Dongming

2014-03-01

Rare-event physics experiments require the use of material with unprecedented radio-purity. Low background counting assay capabilities and detectors are critical for determining the sensitivity of the planned ultra-low background experiments. A low-background counting, LBC, facility has been built at the 4850-Level Davis Campus of the Sanford Underground Research Facility to perform screening of material and detector parts. Like many rare event physics experiments, our LBC uses lead shielding to mitigate background radiation. Corrosion of lead brick shielding in subterranean installations creates radon plate-out potential as well as human risks of ingestible or respirable lead compounds. Our LBC facilities employ an exposed lead shield requiring clean smooth surfaces. A cleaning process of low-activity silica sand blasting and borated paraffin hot coating preservation was employed to guard against corrosion due to chemical and biological exposures. The resulting lead shield maintains low background contribution integrity while fully encapsulating the lead surface. We report the performance of the current LBC and a plan to develop a large germanium well detector for PMT screening. Support provided by Sd governors research center-CUBED, NSF PHY-0758120 and Sanford Lab.

Radioactivity teaching: Environmental consequences of the radiological accident in Goiânia (Brazil)

NASA Astrophysics Data System (ADS)

Anjos, R. M.; Facure, A.; Lima, E. L. N.; Gomes, P. R. S.; Santos, M. S.; Brage, J. A. P.; Okuno, E.; Yoshimura, E. M.; Umisedo, N. K.

2001-03-01

Ionizing radiation and its effects on human beings, radiation protection, and radiological accident prevention are topics usually not included in the physics courses at the Brazilian universities. As a consequence, high school teachers are not able to enlighten their students when radiological or nuclear accidents occur. This paper presents a teaching program on ionizing radiation physics, to be applied to undergraduate physics students and to physics high school teachers. It is based on the environmental consequences of the 1987 radiological accident in Goiânia. This program was applied to two undergraduate physics students, in 1999, at the Universidade Federal Fluminense, Brazil. Results of the gamma ray spectrometry measurements of samples collected in Goiânia by the students are presented.

Nonrelativistic grey S n -transport radiative-shock solutions

DOE PAGES

Ferguson, J. M.; Morel, J. E.; Lowrie, R. B.

2017-06-01

We present semi-analytic radiative-shock solutions in which grey Sn-transport is used to model the radiation, and we include both constant cross sections and cross sections that depend on temperature and density. These new solutions solve for a variable Eddington factor (VEF) across the shock domain, which allows for interesting physics not seen before in radiative-shock solutions. Comparisons are made with the grey nonequilibrium-diffusion radiative-shock solutions of Lowrie and Edwards [1], which assumed that the Eddington factor is constant across the shock domain. It is our experience that the local Mach number is monotonic when producing nonequilibrium-diffusion solutions, but that thismore » monotonicity may disappear while integrating the precursor region to produce Sn-transport solutions. For temperature- and density-dependent cross sections we show evidence of a spike in the VEF in the far upstream portion of the radiative-shock precursor. We show evidence of an adaptation zone in the precursor region, adjacent to the embedded hydrodynamic shock, as conjectured by Drake [2, 3], and also confirm his expectation that the precursor temperatures adjacent to the Zel’dovich spike take values that are greater than the downstream post-shock equilibrium temperature. We also show evidence that the radiation energy density can be nonmonotonic under the Zel’dovich spike, which is indicative of anti-diffusive radiation flow as predicted by McClarren and Drake [4]. We compare the angle dependence of the radiation flow for the Sn-transport and nonequilibriumdiffusion radiation solutions, and show that there are considerable differences in the radiation flow between these models across the shock structure. Lastly, we analyze the radiation flow to understand the cause of the adaptation zone, as well as the structure of the Sn-transport radiation-intensity solutions across the shock structure.« less

Nonrelativistic grey S n -transport radiative-shock solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferguson, J. M.; Morel, J. E.; Lowrie, R. B.

We present semi-analytic radiative-shock solutions in which grey Sn-transport is used to model the radiation, and we include both constant cross sections and cross sections that depend on temperature and density. These new solutions solve for a variable Eddington factor (VEF) across the shock domain, which allows for interesting physics not seen before in radiative-shock solutions. Comparisons are made with the grey nonequilibrium-diffusion radiative-shock solutions of Lowrie and Edwards [1], which assumed that the Eddington factor is constant across the shock domain. It is our experience that the local Mach number is monotonic when producing nonequilibrium-diffusion solutions, but that thismore » monotonicity may disappear while integrating the precursor region to produce Sn-transport solutions. For temperature- and density-dependent cross sections we show evidence of a spike in the VEF in the far upstream portion of the radiative-shock precursor. We show evidence of an adaptation zone in the precursor region, adjacent to the embedded hydrodynamic shock, as conjectured by Drake [2, 3], and also confirm his expectation that the precursor temperatures adjacent to the Zel’dovich spike take values that are greater than the downstream post-shock equilibrium temperature. We also show evidence that the radiation energy density can be nonmonotonic under the Zel’dovich spike, which is indicative of anti-diffusive radiation flow as predicted by McClarren and Drake [4]. We compare the angle dependence of the radiation flow for the Sn-transport and nonequilibriumdiffusion radiation solutions, and show that there are considerable differences in the radiation flow between these models across the shock structure. Lastly, we analyze the radiation flow to understand the cause of the adaptation zone, as well as the structure of the Sn-transport radiation-intensity solutions across the shock structure.« less

Some physics from 550 BC to AD 1948.

PubMed

Ganz, Jeremy C

2014-01-01

This chapter outlines terminology and its origins. It traces the development of physics ideas from Thales of Miletus, via Isaac Newton, to the nuclear physics investigations at the beginning of the twentieth century. It also outlines the evolving technology required to make the discoveries that would form the basis of radiosurgery. Up to the 1920s, all experiments on atomic structure and radioactivity had involved the use of vacuum tubes and naturally occurring radioactive substances. There was a need to make useable subatomic particles to obtain better understanding of the interior structure of atoms. Because of this, machines that could make atoms move at high speed were invented, known as particle accelerators. A new era had dawned. There is a brief mention of the effect of radiation on living tissue and of the units used to measure it.

The DOSIS -Experiment onboard the Columbus Laboratory of the International Space Station -First Mission Results from the Active DOSTEL Instruments

NASA Astrophysics Data System (ADS)

Burmeister, Soenke; Berger, Thomas; Beaujean, Rudolf; Boehme, Matthias; Haumann, Lutz; Kortmann, Onno; Labrenz, Johannes; Reitz, Guenther

Besides the effects of the microgravity environment, and the psychological and psychosocial problems encountered in confined spaces, radiation is the main health detriment for long dura-tion human space missions. The radiation environment encountered in space differs in nature from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones encountered on earth for occupational radiation workers. Accurate knowledge of the physical characteristics of the space radiation field in dependence on the solar activity, the orbital parameters and the different shielding configurations of the International Space Station ISS is therefore needed. For the investigation of the spatial and temporal distribution of the radiation field inside the European COLUMBUS module the DLR experiment DOSIS (Dose Distribution Inside the ISS) was launched on July 15th 2009 with STS-127 to the ISS. The experimental package was transferred from the Space Shuttle into COLUMBUS on July 18th. It consists in a first part of a combination of passive detector packages (PDP) distributed at 11 locations inside the European Columbus Laboratory. The second part are two active radiation detectors (DOSTELs) with a DDPU (DOSIS Data and Power Unit) in a nomex pouch (DOSIS MAIN BOX) mounted at a fixed location beneath the European Physiology Module (EPM) inside COLUMBUS. After the successful installation the active part has been activated on the 18th July 2009. Each of the DOSTEL units consists of two 6.93 cm PIPS silicon detectors forming a telescope with an opening angle of 120. The two DOSTELs are mounted with their telescope axis perpendicular to each other to investigate anisotropies of the radiation field inside the COLUMBUS module especially during the passes through the South Atlantic Anomaly (SAA) and during Solar Particle Events (SPEs). The data from the DOSTEL units are transferred to ground via the EPM rack which is activated approximately every four weeks for this action. The first data downlink was performed on July 31st 2009. First Results for the DOSTEL measurements such as count rate profiles, dose rates and LET spectra will be presented in comparison to the data obtained by other experiments.

1987 Nuclear Science Symposium, 34th, and 1987 Symposium on Nuclear Power Systems, 19th, San Francisco, CA, Oct. 21-23, 1987, Proceedings

NASA Astrophysics Data System (ADS)

Armantrout, Guy A.

1988-02-01

The present conference consideres topics in radiation detectors, advanced electronic circuits, data acquisition systems, radiation detector systems, high-energy and nuclear physics radiation detection, spaceborne instrumentation, health physics and environmental radiation detection, nuclear medicine, nuclear well logging, and nuclear reactor instrumentation. Attention is given to the response of scintillators to heavy ions, phonon-mediated particle detection, ballistic deficits in pulse-shaping amplifiers, fast analog ICs for particle physics, logic cell arrays, the CERN host interface, high performance data buses, a novel scintillating glass for high-energy physics applications, background events in microchannel plates, a tritium accelerator mass spectrometer, a novel positron tomograph, advancements in PET, cylindrical positron tomography, nuclear techniques in subsurface geology, REE borehole neutron activation, and a continuous tritium monitor for aqueous process streams.

Interference with electrons: from thought to real experiments

NASA Astrophysics Data System (ADS)

Matteucci, Giorgio

2013-11-01

The two-slit interference experiment is usually adopted to discuss the superposition principle applied to radiation and to show the peculiar wave behaviour of material particles. Diffraction and interference of electrons have been demonstrated using, as interferometry devices, a hole, a slit, double hole, two-slits, an electrostatic biprism etc. A number of books, short movies and lectures on the web try to popularize the mysterious behaviour of electrons on the basis of Feynman thought experiment which consists of a Young two-hole interferometer equipped with a detector to reveal single electrons. A short review is reported regarding, i) the pioneering attempts carried out to demonstrate that interference patterns could be obtained with single electrons through an interferometer and, ii) recent experiments, which can be considered as the realization of the thought electron interference experiments adopted by Einstein-Bohr and subsequently by Feynman to discuss key features of quantum physics.

The US/USSR Biological Satellite Program: COSMOS 936 Mission Overview

NASA Technical Reports Server (NTRS)

Souza, K. A.

1978-01-01

On August 3, 1977, the Soviet Union launched Cosmos 936, an unmanned spacecraft carrying biology and physics experiments from 9 countries, including both the Soviet Union and U.S. The launch marked the second time the Soviet Union has flown U.S. experiments aboard one of its spacecraft, the first being Cosmos 782 launched Nov. 25, 1975, which remained in orbit 19.5 days. Aboard Cosmos 936 were: 30 young male Wistar SPF rats, 20 of which was exposed to hypogravity during flight while the remainder were subjected to a l x g acceleration by continuous configuration; 2) experiments with plants and fruit flies; 3) radiation physics experiments; and 4) a heat convection experiment. After 18.5 days in orbit, the spacecraft landed in central Asia where a Soviet recovery team began experiment operations, including animal autopsies, within 4.5 hr of landing. Half of the animals were autopsied at the recovery site and the remainder returned to Moscow and allowed to readapt to terrestrial gravity for 25 days after which they, too, were autopsied. Specimens for U.S. were initially prepared at the recovery site or Soviet laboratories and transferred to U.S. laboratories for complete analyses. An overview of the mission focusing on preflight, on-orbit, and postflight activities pertinent to the seven U.S. experiments aboard Cosmos 936 will be presented.

Solar Radiation Transport in the Cloudy Atmosphere: A 3D Perspective on Observations and Climate Impacts

NASA Technical Reports Server (NTRS)

Davis, Anthony B.; Marshak, Alexander

2010-01-01

The interplay of sunlight with clouds is a ubiquitous and often pleasant visual experience, but it conjures up major challenges for weather, climate, environmental science and beyond. Those engaged in the characterization of clouds (and the clear air nearby) by remote sensing methods are even more confronted. The problem comes, on the one hand, from the spatial complexity of real clouds and, on the other hand, from the dominance of multiple scattering in the radiation transport. The former ingredient contrasts sharply with the still popular representation of clouds as homogeneous plane-parallel slabs for the purposes of radiative transfer computations. In typical cloud scenes the opposite asymptotic transport regimes of diffusion and ballistic propagation coexist. We survey the three-dimensional (3D) atmospheric radiative transfer literature over the past 50 years and identify three concurrent and intertwining thrusts: first, how to assess the damage (bias) caused by 3D effects in the operational 1D radiative transfer models? Second, how to mitigate this damage? Finally, can we exploit 3D radiative transfer phenomena to innovate observation methods and technologies? We quickly realize that the smallest scale resolved computationally or observationally may be artificial but is nonetheless a key quantity that separates the 3D radiative transfer solutions into two broad and complementary classes: stochastic and deterministic. Both approaches draw on classic and contemporary statistical, mathematical and computational physics.

21 CFR 201.80 - Specific requirements on content and format of labeling for human prescription drug and...

Code of Federal Regulations, 2012 CFR

2012-04-01

... important nuclear physical characteristics, such as the principal radiation emission data, external radiation, and physical decay characteristics. (2) If appropriate, other important chemical or physical...; and/or (iii) The drug is indicated for the relief of symptoms associated with a disease or syndrome, e...

21 CFR 201.80 - Specific requirements on content and format of labeling for human prescription drug and...

Code of Federal Regulations, 2013 CFR

2013-04-01

... important nuclear physical characteristics, such as the principal radiation emission data, external radiation, and physical decay characteristics. (2) If appropriate, other important chemical or physical...; and/or (iii) The drug is indicated for the relief of symptoms associated with a disease or syndrome, e...

21 CFR 201.80 - Specific requirements on content and format of labeling for human prescription drug and...

Code of Federal Regulations, 2010 CFR

2010-04-01

... important nuclear physical characteristics, such as the principal radiation emission data, external radiation, and physical decay characteristics. (2) If appropriate, other important chemical or physical...; and/or (iii) The drug is indicated for the relief of symptoms associated with a disease or syndrome, e...

21 CFR 201.80 - Specific requirements on content and format of labeling for human prescription drug and...

Code of Federal Regulations, 2014 CFR

2014-04-01

... important nuclear physical characteristics, such as the principal radiation emission data, external radiation, and physical decay characteristics. (2) If appropriate, other important chemical or physical...; and/or (iii) The drug is indicated for the relief of symptoms associated with a disease or syndrome, e...

21 CFR 201.80 - Specific requirements on content and format of labeling for human prescription drug and...

Code of Federal Regulations, 2011 CFR

2011-04-01

... important nuclear physical characteristics, such as the principal radiation emission data, external radiation, and physical decay characteristics. (2) If appropriate, other important chemical or physical...; and/or (iii) The drug is indicated for the relief of symptoms associated with a disease or syndrome, e...

Out-of-Body Experience During Awake Craniotomy.

PubMed

Bos, Eelke M; Spoor, Jochem K H; Smits, Marion; Schouten, Joost W; Vincent, Arnaud J P E

2016-08-01

The out-of-body experience (OBE), during which a person feels as if he or she is spatially removed from the physical body, is a mystical phenomenon because of its association with near-death experiences. Literature implicates the cortex at the temporoparietal junction (TPJ) as the possible anatomic substrate for OBE. We present a patient who had an out-of-body experience during an awake craniotomy for resection of low-grade glioma. During surgery, stimulation of subcortical white matter in the left TPJ repetitively induced OBEs, in which the patient felt as if she was floating above the operating table looking down on herself. We repetitively induced OBE by subcortical stimulation near the left TPJ during awake craniotomy. Diffusion tensor imaging tractography implicated the posterior thalamic radiation as a possible substrate for autoscopic phenomena. Copyright © 2016 Elsevier Inc. All rights reserved.

Remote sensing of smoke, clouds, and radiation using AVIRIS during SCAR experiments

NASA Technical Reports Server (NTRS)

Gao, Bo-Cai; Remer, Lorraine; Kaufman, Yorman J.

1995-01-01

During the past two years, researchers from several institutes joined together to take part in two SCAR experiments. The SCAR-A (Sulfates, Clouds And Radiation - Atlantic) took place in the mid-Atlantic region of the United States in July, 1993. remote sensing data were acquired with the Airborne Visible Infrared Imaging Spectrometer (AVIRIS), the MODIS Airborne Simulator (MAS), and a RC-10 mapping camera from an ER-2 aircraft at 20 km. In situ measurements of aerosol and cloud microphysical properties were made with a variety of instruments equipped on the University of Washington's C-131A research aircraft. Ground based measurements of aerosol optical depths and particle size distributions were made using a network of sunphotometers. The main purpose of SCAR-A experiment was to study the optical, physical and chemical properties of sulfate aerosols and their interaction with clouds and radiation. Sulfate particles are believed to affect the energy balance of the earth by directly reflecting solar radiation back to space and by increasing the cloud albedo. The SCAR-C (Smoke, Clouds And Radiation - California) took place on the west coast areas during September - October of 1994. Sets of aircraft and ground-based instruments, similar to those used during SCAR-A, were used during SCAR-C. Remote sensing of fires and smoke from AVIRIS and MAS imagers on the ER-2 aircraft was combined with a complete in situ characterization of the aerosol and trace gases from the C-131A aircraft of the University of Washington and the Cesna aircraft from the U.S. Forest Service. The comprehensive data base acquired during SCAR-A and SCAR-C will contribute to a better understanding of the role of clouds and aerosols in global change studies. The data will also be used to develop satellite remote sensing algorithms from MODIS on the Earth Observing System.

Medical health physics: a review.

PubMed

Vetter, Richard J

2004-05-01

Medical health physics is the profession dedicated to the protection of healthcare providers, members of the public, and patients from unwarranted radiation exposure. Medical health physicists must be knowledgeable in the principles of health physics and in the applications of radiation in medicine. Advances in medical health physics require the definition of problems, testing of hypotheses, and gathering of evidence to defend changes in health physics practice and to assist medical practitioners in making changes in their practices as appropriate. Advances in radiation medicine have resulted in new modalities and procedures, some of which have significant potential to cause serious harm. Examples included in this review include radiologic procedures that require very long fluoroscopy times, radiolabeled monoclonal antibodies, and intravascular brachytherapy. This review summarizes evidence that supports changes in consensus recommendations, regulations, and health physics practices associated with recent advances in radiology, nuclear medicine, and radiation oncology. Medical health physicists must continue to gather evidence to support intelligent but practical methods for protection of personnel, the public, and patients as modalities and applications evolve in the practice of medicine.

Medical health physics: a review.

PubMed

Vetter, Richard J

2005-06-01

Medical health physics is the profession dedicated to the protection of healthcare providers, members of the public, and patients from unwarranted radiation exposure. Medical health physicists must be knowledgeable in the principles of health physics and in the applications of radiation in medicine. Advances in medical health physics require the definition of problems, testing of hypotheses, and gathering of evidence to defend changes in health physics practice and to assist medical practitioners in making changes in their practices as appropriate. Advances in radiation medicine have resulted in new modalities and procedures, some of which have significant potential to cause serious harm. Examples included in this review include radiologic procedures that require very long fluoroscopy times, radiolabeled monoclonal antibodies, and intravascular brachytherapy. This review summarizes evidence that supports changes in consensus recommendations, regulations, and health physics practices associated with recent advances in radiology, nuclear medicine, and radiation oncology. Medical health physicists must continue to gather evidence to support intelligent but practical methods for protection of personnel, the public, and patients as modalities and applications evolve in the practice of medicine.

Quality assurance for gamma knives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, E.D.; Banks, W.W.; Fischer, L.E.

1995-09-01

This report describes and summarizes the results of a quality assurance (QA) study of the Gamma Knife, a nuclear medical device used for the gamma irradiation of intracranial lesions. Focus was on the physical aspects of QA and did not address issues that are essentially medical, such as patient selection or prescription of dose. A risk-based QA assessment approach was used. Sample programs for quality control and assurance are included. The use of the Gamma Knife was found to conform to existing standards and guidelines concerning radiation safety and quality control of external beam therapies (shielding, safety reviews, radiation surveys,more » interlock systems, exposure monitoring, good medical physics practices, etc.) and to be compliant with NRC teletherapy regulations. There are, however, current practices for the Gamma Knife not covered by existing, formalized regulations, standards, or guidelines. These practices have been adopted by Gamma Knife users and continue to be developed with further experience. Some of these have appeared in publications or presentations and are slowly finding their way into recommendations of professional organizations.« less

2009 Annual Health Physics Report for the HEU Transparency Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radev, R

2010-04-14

During the 2009 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. LLNL also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2009, there were 159 person-trips that required dose monitoring of the U.S. monitors. Of the 159 person-trips, 149 person-trips were SMVs and 10 person-trips were Transparency Monitoring Office (TMO) trips. There were 4 monitoring visits by TMO monitors to facilities other than UEIE and 10 to UEIE itself. LLNL's Hazard Control Departmentmore » laboratories provided the dosimetry services for the HEU Transparency monitors. In 2009, the HEU Transparency activities in Russia were conducted in a radiologically safe manner for the HEU Transparency monitors in accordance with the expectations of the HEU Transparency staff, NNSA and DOE. The HEU Transparency Program now has over fifteen years of successful experience in developing and providing health and safety support in meeting its technical objectives.« less

Beam-dynamic effects at the CMS BRIL van der Meer scans

NASA Astrophysics Data System (ADS)

Babaev, A.

2018-03-01

The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is responsible for the simulation and measurement of luminosity, beam conditions and radiation fields in the CMS experiment. The project is engaged in operating and developing new detectors (luminometers), adequate for the experimental conditions associated with high values of instantaneous luminosity delivered by the CERN LHC . BRIL operates several detectors based on different physical principles and technologies. Precise and accurate measurements of the delivered luminosity is of paramount importance for the CMS physics program. The absolute calibration of luminosity is achieved by the van der Meer method, which is carried out under specially tailored conditions. This paper presents models used to simulate of beam-dynamic effects arising due to the electromagnetic interaction of colliding bunches. These effects include beam-beam deflection and dynamic-β effect. Both effects are important to luminosity measurements and influence calibration constants at the level of 1-2%. The simulations are carried out based on 2016 CMS van der Meer scan data for proton-proton collisions at a center-of-mass energy of 13 TeV.

Cosmic rays: a review for astrobiologists.

PubMed

Ferrari, Franco; Szuszkiewicz, Ewa

2009-05-01

Cosmic rays represent one of the most fascinating research themes in modern astronomy and physics. Significant progress is being made toward an understanding of the astrophysics of the sources of cosmic rays and the physics of interactions in the ultrahigh-energy range. This is possible because several new experiments in these areas have been initiated. Cosmic rays may hold answers to a great number of fundamental questions, but they also shape our natural habitat and influence the radiation environment of our planet Earth. The importance of the study of cosmic rays has been acknowledged in many fields, including space weather science and astrobiology. Here, we concentrate on the astrobiological aspects of cosmic rays with regard to the enormous amount of new data available, some of which may, in fact, improve our knowledge about the radiation of cosmic origin on Earth. We focus on fluxes arriving at Earth and doses received, and will guide the reader through the wealth of scientific literature on cosmic rays. We have prepared a concise and self-contained source of data and recipes useful for performing interdisciplinary research in cosmic rays and their effects on life on Earth.

Short-pulse, compressed ion beams at the Neutralized Drift Compression Experiment

DOE PAGES

Seidl, P. A.; Barnard, J. J.; Davidson, R. C.; ...

2016-05-01

We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory, with 1-mm beam spot size within 2.5 ns full-width at half maximum. The ion kinetic energy is 1.2 MeV. To enable the short pulse duration and mm-scale focal spot radius, the beam is neutralized in a 1.5-meter-long drift compression section following the last accelerator cell. A short-focal-length solenoid focuses the beam in the presence of the volumetric plasma that is near the target. In the accelerator, the line-charge density increases due to the velocity ramp imparted onmore » the beam bunch. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including select topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Below the transition to melting, the short beam pulses offer an opportunity to study the multi-scale dynamics of radiation-induced damage in materials with pump-probe experiments, and to stabilize novel metastable phases of materials when short-pulse heating is followed by rapid quenching. First experiments used a lithium ion source; a new plasma-based helium ion source shows much greater charge delivered to the target.« less

Operational health physics training

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1992-06-01

The initial four sections treat basic information concerning atomic structure and other useful physical quantities, natural radioactivity, the properties of {alpha}, {beta}, {gamma}, x rays and neutrons, and the concepts and units of radiation dosimetry (including SI units). Section 5 deals with biological effects and the risks associated with radiation exposure. Background radiation and man-made sources are discussed next. The basic recommendations of the ICRP concerning dose limitations: justification, optimization (ALARA concepts and applications) and dose limits are covered in Section seven. Section eight is an expanded version of shielding, and the internal dosimetry discussion has been extensively revised tomore » reflect the concepts contained in the MIRD methodology and ICRP 30. The remaining sections discuss the operational health physics approach to monitoring radiation. Individual sections include radiation detection principles, instrument operation and counting statistics, health physics instruments and personnel monitoring devices. The last five sections deal with the nature of, operation principles of, health physics aspects of, and monitoring approaches to air sampling, reactors, nuclear safety, gloveboxes and hot cells, accelerators and x ray sources. Decontamination, waste disposal and transportation of radionuclides are added topics. Several appendices containing constants, symbols, selected mathematical topics, and the Chart of the Nuclides, and an index have been included.« less

The Mixed-Phase Arctic Cloud Experiment (M-PACE)

NASA Technical Reports Server (NTRS)

Verlinde, J.; Harrington, J. Y.; McFarquhar, G. M.; Yannuzzi, V. T.; Avramov, A.; Greenberg, S.; Johnson, N.; Zhang, G.; Poellot, M. R.; Mather, J. H.;

Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff

NASA Technical Reports Server (NTRS)

Stephens, D. L. Jr; Townsend, L. W.; Miller, J.; Zeitlin, C.; Heilbronn, L.

2002-01-01

Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R2 respectively. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff.

PubMed

Stephens, D L; Townsend, L W; Miller, J; Zeitlin, C; Heilbronn, L

2002-01-01

Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R2 respectively. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Radiation Exposure from Medical Exams and Procedures

MedlinePlus

Fact Sheet Adopted: January 2010 Health Physics Society Specialists in Radiation Safety Radiation Exposure from Medical Exams and Procedures Ionizing radiation is used daily in hospitals and clinics ...

Research and development program, fiscal year 1966

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1964-04-01

The biomedical program of the Laboratory of Nuclear Medicine and Radiation Biology for FY 1966 is conducted within the scope of the following categories: Somatic Effects of Radiation; Combating Detrimental Effects of Radiation; Molecular and Cellular Level Studies; Environmental Radiation Studies; Radiological and Health Physics and Instrumentation; Chemical Toxicity; Cancer Research; and Selected Beneficial Applications. The overall objectives of the Laboratory within these areas of the Biology and Medicine program may be summarized as follows: (1) investigation of the effects of ionizing radiation on living organisms and systems of biological significance; (2) investigation of the dynamic aspects of physiological andmore » biochemical processes in man, animals and plants and how these processes are modified by radiation and related pathological states; (3) the assessment and study of the immediate and long term consequences of the operation or detonation of nuclear devices on the fauna, and flora in man's environment and on man; (4) the development of methods of minimizing or preventing the detrimental effects of ionizing radiation; (5) research in, and development of, beneficial uses of ionizing radiation and radioactive substances in medicine and biology; (6) research in the development of new and more efficient radiation detection devices; (7) research, including field studies, as mutually agreed upon by the Commission and the University, in connection with the conduct of weapon tests and biomedical and civil effects experiments at such tests conducted at continental and overseas test sites; and (8) the conduct of training and educational activities in the biological and medical aspects of radiation and related fields.« less

First Experiments with Planar Wire Arrays on U Michigan's Linear Transformer Driver

NASA Astrophysics Data System (ADS)

Safronova, A. S.; Kantsyrev, V. L.; Weller, M. E.; Shrestha, I. K.; Shlyaptseva, V. V.; Cooper, M. C.; Lorance, M.; Stafford, A.; Patel, S. G.; Steiner, A. M.; Yager-Elorriaga, D. A.; Jordan, N. M.; Gilgenbach, R. M.

2014-10-01

For petawatt-class Z-pinch accelerators, a Linear Transformer Driver (LTD)-driven accelerator promises to be (at a given pinch current and implosion time) more efficient than the conventionally used Marx-driven accelerator. Because there exists almost no data on how wire arrays radiate on LTD-based machines in the USA, it is very important to perform radiation and plasma physics studies on this new type of generator. We report on the first outcome of the new partnership with University of Michigan (UM), which resulted in successful UNR-UM experiments on the low-impedance MAIZE generator with planar wire arrays (PWA). PWA is a novel wire array load that was introduced and tested in detail on high-impedance Zebra at UNR during the last years and found to be the most efficient radiator. Implosion of Al Double PWAs of different configurations were achieved on MAIZE, observed with a set of various diagnostics which include x-ray diode detectors, x-ray spectroscopy and imaging, and shadowgraphy. Al and Mg plasmas of more than 450 eV were studied in detail. Research supported by NNSA under DOE Cooperative Agreement DE-NA0001984. S. G. Patel and A. M. Steiner supported by Sandia National Laboratories. D. A. Yager-Elorriaga supported by NSF GF.

Herbert M. Parker: Publications and other contributions to radiological and health physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kathren, R.L.; Baalman, R.W.; Bair, W.J.

For more than a half century, Herbert M. Parker was a leading force in radiological physics. This book brings together all of Parker's published and unpublished papers and is divided into six parts. The second edition is on his work in medical physics. The third part is on his contribution to the evolution of radiological units. The fourth and largest portion of the book is on radiation protection: the Manhattan Project and beyond. There are no less than 31 subsections to this part of the book, and it includes: possible hazards of repeated fluoroscopy in infants, health protection, health physicsmore » implementation and radiation protection, radiation protection in the atomic energy industry, radiation exposure from environmental hazards, personnel dosimetry for radiation accidents, and an article on the dilemma of lung dosimetry.« less

Multiscale approach to the physics of radiation damage with ions

NASA Astrophysics Data System (ADS)

Surdutovich, Eugene; Solov'yov, Andrey V.

2013-04-01

We review a multiscale approach to the physics of ion-beam cancer therapy, an approach suggested in order to understand the interplay of a large number of phenomena involved in radiation damage scenario occurring on a range of temporal, spatial, and energy scales. We briefly overview its history and present the current stage of its development. The differences of the multiscale approach from other methods of understanding and assessment of radiation damage are discussed as well as its relationship to other branches of physics, chemistry and biology.

Exploring Rotations Due to Radiation Pressure: 2-D to 3-D Transition Is Interesting!

ERIC Educational Resources Information Center

Waxman, Michael A.

2010-01-01

Radiation pressure is an important topic within a standard physics course (see, in particular, Refs. 1 and 2). The physics of radiation pressure is described, the magnitude of it is derived, both for the case of a perfectly absorbing surface and of a perfect reflector, and various applications of this interesting effect are discussed, such as…

Methylglyoxal-bis(guanylhydrazone), a polyamine analogue, sensitized γ-radiation-induced cell death in HL-60 leukemia cells Sensitizing effect of MGBG on γ-radiation-induced cell death.

PubMed

Kim, Jin Sik; Lee, Jin; Chung, Hai Won; Choi, Han; Paik, Sang Gi; Kim, In Gyu

2006-09-01

Methylglyoxal-bis(guanylhydrazone) (MGBG), a polyamine analogue, has been known to inhibit the biosynthesis of polyamines, which are important in cell proliferation. We showed that MGBG treatment significantly affected γ-radiation-induced cell cycle transition (G(1)/G(0)→S→G(2)/M) and thus γ-radiation-induced cell death. As determined by micronuclei and comet assay, we showed that it sensitized the cytotoxic effect induced by γ-radiation. One of the reasons is that polyamine depletion by MGBG treatment did not effectively protect against the chemical (OH) or physical damage to DNA caused by γ-radiation. Through in vitro experiment, we confirmed that DNA strand breaks induced by γ-radiation was prevented more effectively in the presence of polyamines (spermine and spermidine) than in the absence of polyamines. MGBG also blocks the cell cycle transition caused by γ-radiation (G(2) arrest), which helps protect cells by allowing time for DNA repair before entry into mitosis or apoptosis, via the down regulation of cyclin D1, which mediates the transition from G(1) to S phase of cell cycle, and ataxia telangiectasia mutated, which is involved in the DNA sensing, repair and cell cycle check point. Therefore, the abrogation of G(2) arrest sensitizes cells to the effect of γ-radiation. As a result, γ-radiation-induced cell death increased by about 2.5-3.0-fold in cells treated with MGBG. However, exogenous spermidine supplement partially relieved this γ-radiation-induced cytotoxicity and cell death. These findings suggest a potentially therapeutic strategy for increasing the cytotoxic efficacy of γ-radiation.

WE-A-207-01: Memorial Lecturer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muller-Runkel, R

The Medical Physics community lost one of its early pioneers in radiation oncology physics, Jacques Ovadia, who passed away in April of 2014 at the age of 90. Jacques received his Ph.D. in Nuclear Physics from the University of Illinois at Urbana in 1951. Subsequently, under the guidance of John Laughlin, he was introduced to the field of Medical Physics. When John moved to Memorial Sloan Kettering, Jacques followed him. There he gained clinical experience and expertise in the then cutting-edge field of high energy electron beam therapy. In 1956, Jacques joined Dr. Erich Uhlmann at Michael Reese Hospital inmore » Chicago where one of the country’s first high energy medical linear accelerators had just been installed. During his 35 year tenure, Dr. Ovadia built a strong Medical Physics department that merged in 1984 with that of the University of Chicago. Jacques pioneered the use of high energy electron beams to treat deep seated tumors, multiple-field chest wall irradiation with variable electron energies, and even anticipated the current interest in high energy electron beam grid-therapy. At an early stage, he introduced a simulator, computerized treatment planning and in-house developed record and verify software. He retired in 1990 as Professor emeritus in Radiation and Cellular Biology at the University of Chicago. Dr. Ovadia was an early and strong supporter of AAPM. He was present at the Chicago ROMPS meeting where the decision was made to form an independent professional society for medical physics. He served as AAPM president in 1976. Jacques Ovadia is survived by his wife of 58 years, Florence, their daughter Corinne Graefe and son Marc Ovadia, MD, as well as four grandchildren and one great-grandchild. Jacques’ dynamic and ever enthusiastic personality inspired all who collaborated with him. He will be greatly missed.« less

An Experimental Concept for Probing Nonlinear Physics in Radiation Belts

NASA Astrophysics Data System (ADS)

Crabtree, C. E.; Ganguli, G.; Tejero, E. M.; Amatucci, B.; Siefring, C. L.

2017-12-01

A sounding rocket experiment, Space Measurement of Rocket-Released Turbulence (SMART), can be used to probe the nonlinear response to a known stimulus injected into the radiation belt. Release of high-speed neutral barium atoms (8- 10 km/s) generated by a shaped charge explosion in the ionosphere can be used as the source of free energy to seed weak turbulence in the ionosphere. The Ba atoms are photo-ionized forming a ring velocity distribution of heavy Ba+ that is known to generate lower hybrid waves. Induced nonlinear scattering will convert the lower hybrid waves into EM whistler/magnetosonic waves. The escape of the whistlers from the ionospheric region into the radiation belts has been studied and their observable signatures quantified. The novelty of the SMART experiment is to make coordinated measurement of the cause and effect of the turbulence in space plasmas and from that to deduce the role of nonlinear scattering in the radiation belts. Sounding rocket will carry a Ba release module and an instrumented daughter section that includes vector wave magnetic and electric field sensors, Langmuir probes and energetic particle detectors. The goal of these measurements is to determine the whistler and lower hybrid wave amplitudes and spectrum in the ionospheric source region and look for precipitated particles. The Ba release may occur at 600-700 km near apogee. Ground based cameras and radio diagnostics can be used to characterize the Ba and Ba+ release. The Van Allen Probes can be used to detect the propagation of the scattering-generated whistler waves and their effects in the radiation belts. By detecting whistlers and measuring their energy density in the radiation belts the SMART mission will confirm the nonlinear generation of whistlers through scattering of lower hybrid along with other nonlinear responses of the radiation belts and their connection to weak turbulence.

Characterizing Quality Factor of Niobium Resonators Using a Markov Chain Monte Carlo Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu Thakur, Ritoban; Tang, Qing Yang; McGeehan, Ryan

The next generation of radiation detectors in high precision Cosmology, Astronomy, and particle-astrophysics experiments will rely heavily on superconducting microwave resonators and kinetic inductance devices. Understanding the physics of energy loss in these devices, in particular at low temperatures and powers, is vital. We present a comprehensive analysis framework, using Markov Chain Monte Carlo methods, to characterize loss due to two-level system in concert with quasi-particle dynamics in thin-film Nb resonators in the GHz range.

SiPM timing characteristics under conditions of a large background for lidars

NASA Astrophysics Data System (ADS)

Antonova, A. M.; Kaplin, V. A.

2018-01-01

Silicon photomultipliers (SiPM) have found their use in various fields of industry and scientific experiments. This paper considers study of the SiPM possibility to detect low-intensity light pulses (down to single photons) under high-intensity background illumination. This may be useful for the development of laser rangefinders operating under natural light using SiPM as crucial photosensor. Moreover, the presented data describes some physical properties of LIDAR with SiPM under radiation exposure, which always affects its intrinsic noise.

Testing general relativity in space-borne and astronomical laboratories

NASA Technical Reports Server (NTRS)

Will, Clifford M.

1989-01-01

The current status of space-based experiments and astronomical observations designed to test the theory of general relativity is surveyed. Consideration is given to tests of post-Newtonian gravity, searches for feeble short-range forces and gravitomagnetism, improved measurements of parameterized post-Newtonian parameter values, explorations of post-Newtonian physics, tests of the Einstein equivalence principle, observational tests of post-Newtonian orbital effects, and efforts to detect quadrupole and dipole radiation damping. Recent numerical results are presented in tables.

A journey into medical physics as viewed by a physicist

NASA Astrophysics Data System (ADS)

Gueye, Paul

2007-03-01

The world of physics is usually linked to a large variety of subjects spanning from astrophysics, nuclear/high energy physics, materials and optical sciences, plasma physics etc. Lesser is known about the exciting world of medical physics that includes radiation therapy physics, medical diagnostic and imaging physics, nuclear medicine physics, and medical radiation safety. These physicists are typically based in hospital departments of radiation oncology or radiology, and provide technical support for patient diagnosis and treatment in a clinical environment. This talk will focus on providing a bridge between selected areas of physics and their medical applications. The journey will first start from our understanding of high energy beam production and transport beamlines for external beam treatment of diseases (e.g., electron, gamma, X-ray and proton machines) as they relate to accelerator physics. We will then embrace the world of nuclear/high energy physics where detectors development provide a unique tool for understanding low energy beam distribution emitted from radioactive sources used in Brachytherapy treatment modality. Because the ultimate goal of radiation based therapy is its killing power on tumor cells, the next topic will be microdosimetry where responses of biological systems can be studied via electromagnetic systems. Finally, the impact on the imaging world will be embraced using tools heavily used in plasma physics, fluid mechanics and Monte Carlo simulations. These various scientific areas provide unique opportunities for faculty and students at universities, as well as for staff from research centers and laboratories to contribute in this field. We will conclude with the educational training related to medical physics programs.

Screening for thyroid cancer in survivors of childhood and young adult cancer treated with neck radiation.

PubMed

Tonorezos, Emily S; Barnea, Dana; Moskowitz, Chaya S; Chou, Joanne F; Sklar, Charles A; Elkin, Elena B; Wong, Richard J; Li, Duan; Tuttle, R Michael; Korenstein, Deborah; Wolden, Suzanne L; Oeffinger, Kevin C

2017-06-01

The optimal method of screening for thyroid cancer in survivors of childhood and young adult cancer exposed to neck radiation remains controversial. Outcome data for a physical exam-based screening approach are lacking. We conducted a retrospective review of adult survivors of childhood and young adult cancer with a history of neck radiation followed in the Adult Long-Term Follow-Up Clinic at Memorial Sloan Kettering between November 2005 and August 2014. Eligible patients underwent a physical exam of the thyroid and were followed for at least 1 year afterwards. Ineligible patients were those with prior diagnosis of benign or malignant thyroid nodules. During a median follow-up of 3.1 years (range 0-9.4 years), 106 ultrasounds and 2277 physical exams were performed among 585 patients. Forty survivors had an abnormal thyroid physical exam median of 21 years from radiotherapy; 50% of those with an abnormal exam were survivors of Hodgkin lymphoma, 60% had radiation at ages 10-19, and 53% were female. Ultimately, 24 underwent fine needle aspiration (FNA). Surgery revealed papillary carcinoma in seven survivors; six are currently free of disease and one with active disease is undergoing watchful waiting. Among those with one or more annual visits, representing 1732 person-years of follow-up, no cases of thyroid cancer were diagnosed within a year of normal physical exam. These findings support the application of annual physical exam without routine ultrasound for thyroid cancer screening among survivors with a history of neck radiation. Survivors with a history of neck radiation may not require routine thyroid ultrasound for thyroid cancer screening. Among adult survivors of childhood and young adult cancer with a history of radiation therapy to the neck, annual physical exam is an acceptable thyroid cancer screening strategy.

Radiation sources with planar wire arrays and planar foils for inertial confinement fusion and high energy density physics research

NASA Astrophysics Data System (ADS)

Kantsyrev, V. L.; Chuvatin, A. S.; Safronova, A. S.; Rudakov, L. I.; Esaulov, A. A.; Velikovich, A. L.; Shrestha, I.; Astanovitsky, A.; Osborne, G. C.; Shlyaptseva, V. V.; Weller, M. E.; Keim, S.; Stafford, A.; Cooper, M.

2014-03-01

This article reports on the joint success of two independent lines of research, each of them being a multi-year international effort. One of these is the development of innovative sources, such as planar wire arrays (PWAs). PWAs turned out to be a prolific radiator, which act mainly as a resistor, even though the physical mechanism of efficient magnetic energy conversion into radiation still remains unclear. We review the results of our extensive studies of PWAs. We also report the new results of the experimental comparison PWAs with planar foil liners (another promising alternative to wire array loads at multi-mega-ampere generators). Pioneered at UNR, the PWA Z-pinch loads have later been tested at the Sandia National Laboratories (SNL) on the Saturn generator, on GIT-12 machine in Russia, and on the QiangGuang-1 generator in China, always successfully. Another of these is the drastic improvement in energy efficiency of pulsed-power systems, which started in early 1980s with Zucker's experiments at Naval Research Laboratory (NRL). Successful continuation of this approach was the Load Current Multiplier (LCM) proposed by Chuvatin in collaboration with Rudakov and Weber from NRL. The 100 ns LCM was integrated into the Zebra generator, which almost doubled the plasma load current, from 0.9 to 1.7 MA. The two above-mentioned innovative approaches were used in combination to produce a new compact hohlraum radiation source for ICF, as jointly proposed by SNL and UNR [Jones et al., Phys. Rev. Lett. 104, 125001 (2010)]. The first successful proof-of-the-principle experimental implementation of new hohlraum concept at university-scale generator Zebra/LCM is demonstrated. A numerical simulation capability with VisRaD code (from PRISM Co.) established at UNR allowed for the study of hohlraum coupling physics and provides the possibility of optimization of a new hohlraum. Future studies are discussed.

Strong-field physics with mid-infrared lasers

NASA Astrophysics Data System (ADS)

Pogorelsky, I. V.

2002-04-01

Mid-infrared gas laser technology promises to become a unique tool for research in strong-field relativistic physics. The degree to which physics is relativistic is determined by a ponderomotive potential. At a given intensity, a 10 μm wavelength CO2 laser reaches a 100 times higher ponderomotive potential than the 1 μm wavelength solid state lasers. Thus, we can expect a proportional increase in the throughput of such processes as laser acceleration, x-ray production, etc. These arguments have been confirmed in proof-of-principle Thomson scattering and laser acceleration experiments conducted at BNL and UCLA where the first terawatt-class CO2 lasers are in operation. Further more, proposals for the 100 TW, 100 fs CO2 lasers based on frequency-chirped pulse amplification have been conceived. Such lasers can produce physical effects equivalent to a hypothetical multi-petawatt solid state laser. Ultra-fast mid-infrared lasers will open new routes to the next generation electron and ion accelerators, ultra-bright monochromatic femtosecond x-ray and gamma sources, allow to attempt the study of Hawking-Unruh radiation, and explore relativistic aspects of laser-matter interactions. We review the present status and experiments with terawatt-class CO2 lasers, sub-petawatt projects, and prospective applications in strong-field science. .

STRONG FIELD PHYSICS WITH MID INFRARED LASERS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

POGORELSKY,I.V.

2001-08-27

Mid-infrared gas laser technology promises to become a unique tool for research in strong-field relativistic physics. The degree to which physics is relativistic is determined by a ponderomotive potential. At a given intensity, a 10 {micro}m wavelength CO{sub 2} laser reaches a 100 times higher ponderomotive potential than the 1 {micro}m wavelength solid state lasers. Thus, we can expect a proportional increase in the throughput of such processes as laser acceleration, x-ray production, etc. These arguments have been confirmed in proof-of-principle Thomson scattering and laser acceleration experiments conducted at BNL and UCLA where the first terawatt-class CO{sub 2} lasers aremore » in operation. Further more, proposals for the 100 TW, 100 fs CO{sub 2} lasers based on frequency-chirped pulse amplification have been conceived. Such lasers can produce physical effects equivalent to a hypothetical multi-petawatt solid state laser. Ultra-fast mid-infrared lasers will open new routes to the next generation electron and ion accelerators, ultra-bright monochromatic femtosecond x-ray and gamma sources, allow to attempt the study of Hawking-Unruh radiation, and explore relativistic aspects of laser-matter interactions. We review the present status and experiments with terawatt-class CO{sub 2} lasers, sub-petawatt projects, and prospective applications in strong-field science.« less

11th International Conference of Radiation Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1999-07-18

Topics discussed in the conference included the following: Radiation Physics, Radiation Chemistry and modelling--Radiation physics and dosimetry; Electron transfer in biological media; Radiation chemistry; Biophysical and biochemical modelling; Mechanisms of DNA damage; Assays of DNA damage; Energy deposition in micro volumes; Photo-effects; Special techniques and technologies; Oxidative damage. Molecular and cellular effects-- Photobiology; Cell cycle effects; DNA damage: Strand breaks; DNA damage: Bases; DNA damage Non-targeted; DNA damage: other; Chromosome aberrations: clonal; Chromosomal aberrations: non-clonal; Interactions: Heat/Radiation/Drugs; Biochemical effects; Protein expression; Gene induction; Co-operative effects; ``Bystander'' effects; Oxidative stress effects; Recovery from radiation damage. DNA damage and repair -- DNAmore » repair genes; DNA repair deficient diseases; DNA repair enzymology; Epigenetic effects on repair; and Ataxia and ATM.« less

Protection against radiation (biological, pharmacological, chemical, physical)

NASA Technical Reports Server (NTRS)

Saksonov, P. P.

1975-01-01

Physical, chemical, and biological protection for astronauts from penetrating radiation on long-term space flights is discussed. The status of pharmacochemical protection, development of protective substances, medical use of protective substances, protection for spacecraft ecologic systems, adaptogens and physical conditioning, bone marrow transplants and local protection are discussed. Combined use of local protection and pharmacochemical substances is also briefly considered.

The MAJORANA Parts Tracking Database

NASA Astrophysics Data System (ADS)

Abgrall, N.; Aguayo, E.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Combs, D. C.; Cuesta, C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Esterline, J.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V. E.; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J. Diaz; Leviner, L. E.; Loach, J. C.; MacMullin, J.; Martin, R. D.; Meijer, S. J.; Mertens, S.; Miller, M. L.; Mizouni, L.; Nomachi, M.; Orrell, J. L.; O`Shaughnessy, C.; Overman, N. R.; Petersburg, R.; Phillips, D. G.; Poon, A. W. P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Soin, A.; Suriano, A. M.; Tedeschi, D.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C.-H.; Yumatov, V.; Zhitnikov, I.

2015-04-01

The MAJORANA DEMONSTRATOR is an ultra-low background physics experiment searching for the neutrinoless double beta decay of 76Ge. The MAJORANA Parts Tracking Database is used to record the history of components used in the construction of the DEMONSTRATOR. The tracking implementation takes a novel approach based on the schema-free database technology CouchDB. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provide a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation. A web application for data entry and a radiation exposure calculator have been developed as tools for achieving the extreme radio-purity required for this rare decay search.

Enabling the Discovery of Gravitational Radiation

NASA Astrophysics Data System (ADS)

Isaacson, Richard

2017-01-01

The discovery of gravitational radiation was announced with the publication of the results of a physics experiment involving over a thousand participants. This was preceded by a century of theoretical work, involving a similarly large group of physicists, mathematicians, and computer scientists. This huge effort was enabled by a substantial commitment of resources, both public and private, to develop the different strands of this complex research enterprise, and to build a community of scientists to carry it out. In the excitement following the discovery, the role of key enablers of this success has not always been adequately recognized in popular accounts. In this talk, I will try to call attention to a few of the key ingredients that proved crucial to enabling the successful discovery of gravitational waves, and the opening of a new field of science.

Construction of the radiation oncology teaching files system for charged particle radiotherapy.

PubMed

Masami, Mukai; Yutaka, Ando; Yasuo, Okuda; Naoto, Takahashi; Yoshihisa, Yoda; Hiroshi, Tsuji; Tadashi, Kamada

2013-01-01

Our hospital started the charged particle therapy since 1996. New institutions for charged particle therapy are planned in the world. Our hospital are accepting many visitors from those newly planned medical institutions and having many opportunities to provide with the training to them. Based upon our experiences, we have developed the radiation oncology teaching files system for charged particle therapy. We adopted the PowerPoint of Microsoft as a basic framework of our teaching files system. By using our export function of the viewer any physician can create teaching files easily and effectively. Now our teaching file system has 33 cases for clinical and physics contents. We expect that we can improve the safety and accuracy of charged particle therapy by using our teaching files system substantially.

DAGON: a 3D Maxwell-Bloch code

NASA Astrophysics Data System (ADS)

Oliva, Eduardo; Cotelo, Manuel; Escudero, Juan Carlos; González-Fernández, Agustín.; Sanchís, Alberto; Vera, Javier; Vicéns, Sergio; Velarde, Pedro

2017-05-01

The amplification of UV radiation and high order harmonics (HOH) in plasmas is a subject of raising interest due to its different potential applications in several fields like environment and security (detection at distance), biology, materials science and industry (3D imaging) and atomic and plasma physics (pump-probe experiments). In order to develop these sources, it is necessary to properly understand the amplification process. Being the plasma an inhomogeneous medium which changes with time, it is desirable to have a full time-dependent 3D description of the interaction of UV and XUV radiation with plasmas. For these reasons, at the Instituto de Fusíon Nuclear we have developed DAGON, a 3D Maxwell-Bloch code capable of studying the full spationtemporal structure of the amplification process abovementioned.

The RICH detector of the CBM experiment

NASA Astrophysics Data System (ADS)

Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H.; Belogurov, S.; Bendarouach, J.; Boldyreva, N.; Deveaux, C.; Dobyrn, V.; Dürr, M.; Eschke, J.; Förtsch, J.; Heep, J.; Höhne, C.; Kampert, K.-H.; Kochenda, L.; Kopfer, J.; Kravtsov, P.; Kres, I.; Lebedev, S.; Lebedeva, E.; Leonova, E.; Linev, S.; Mahmoud, T.; Michel, J.; Miftakhov, N.; Niebur, W.; Ovcharenko, E.; Patel, V.; Pauly, C.; Pfeifer, D.; Querchfeld, S.; Rautenberg, J.; Reinecke, S.; Riabov, Y.; Roshchin, E.; Samsonov, V.; Schetinin, V.; Tarasenkova, O.; Traxler, M.; Ugur, C.; Vznuzdaev, E.; Vznuzdaev, M.

2017-12-01

The CBM-RICH detector is designed to identify electrons with momenta up to 8 GeV/c and high purity as this is essential for the CBM physics program. The detector consist of a CO2-gaseous radiator, a spherical mirror system, and Multi-Anode PhotoMultiplier Tubes (MAPMT) of type H12700 from Hamamatsu as photon detectors. The detector concept was verified through R&D studies and a laterally scaled prototype. The results were summarized in a TDR, in which open issues were defined concerning the readout electronics, the shielding of the magnetic stray field in the MAPMT region, the radiation hardness of the MAPMT sensors, and the mechanical holding structure of the mirror system. In this article an overview is given on the CBM RICH development with focus on those open issues.

Quality Assurance on Undoped CsI Crystals for the Mu2e Experiment

NASA Astrophysics Data System (ADS)

Atanov, N.; Baranov, V.; Budagov, J.; Davydov, Yu. I.; Glagolev, V.; Tereshchenko, V.; Usubov, Z.; Cervelli, F.; Di Falco, S.; Donati, S.; Morescalchi, L.; Pedreschi, E.; Pezzullo, G.; Raffaelli, F.; Spinella, F.; Colao, F.; Cordelli, M.; Corradi, G.; Diociaiuti, E.; Donghia, R.; Giovannella, S.; Happacher, F.; Martini, M.; Miscetti, S.; Ricci, M.; Saputi, A.; Sarra, I.; Echenard, B.; Hitlin, D. G.; Hu, C.; Miyashita, T.; Porter, F.; Zhang, L.; Zhu, R.-Y.; Grancagnolo, F.; Tassielli, G.; Murat, P.

2018-02-01

The Mu2e experiment is constructing a calorimeter consisting of 1,348 undoped CsI crystals in two disks. Each crystal has a dimension of 34 x 34 x 200 mm, and is readout by a large area silicon PMT array. A series of technical specifications was defined according to physics requirements. Preproduction CsI crystals were procured from three firms: Amcrys, Saint-Gobain and Shanghai Institute of Ceramics. We report the quality assurance on crystal's scintillation properties and their radiation hardness against ionization dose and neutrons. With a fast decay time of 30 ns and a light output of more than 100 p.e./MeV measured with a bi-alkali PMT, undoped CsI crystals provide a cost-effective solution for the Mu2e experiment.

Single Bubble Sonoluminescence in Low Gravity and Optical Radiation Pressure Positioning of the Bubble

NASA Technical Reports Server (NTRS)

Thiessen, D. B.; Young, J. E.; Marr-Lyon, M. J.; Richardson, S. L.; Breckon, C. D.; Douthit, S. G.; Jian, P. S.; Torruellas, W. E.; Marston, P. L.

1999-01-01

Several groups of researchers have demonstrated that high frequency sound in water may be used to cause the regular repeated compression and luminescence of a small bubble of gas in a flask. The phenomenon is known as single bubble sonoluminescence (SBSL). It is potentially important because light emitted by the bubble appears to be associated with a significant concentration of energy within the volume of the bubble. Unfortunately, the detailed physical mechanisms causing the radiation of light by oscillating bubbles are poorly understood and there is some evidence that carrying out experiments in a weightless environment may provide helpful clues. In addition, the radiation pressure of laser beams on the bubble may provide a way of simulating weightless experiments in the laboratory. The standard model of SBSL attributes the light emission to heating within the bubble by a spherically imploding shock wave to achieve temperatures of 50,000 K or greater. In an alternative model, the emission is attributed to the impact of a jet of water which is required to span the bubble and the formation of the jet is linked to the buoyancy of the bubble. The coupling between buoyancy and jet formation is a consequence of the displacement of the bubble from a velocity node (pressure antinode) of the standing acoustic wave that drives the radial bubble oscillations. One objective of this grant is to understand SBSL emission in reduced buoyancy on KC-135 parabolic flights. To optimize the design of those experiments and for other reasons which will help resolve the role of buoyancy, laboratory experiments are planned in simulated low gravity in which the radiation pressure of laser light will be used to position the bubble at the acoustic velocity node of the ultrasonic standing wave. Laser light will also be used to push the bubble away from the velocity node, increasing the effective buoyancy. The original experiments on the optical levitation and radiation pressure on bubbles in water by Unger and Marston noted above were carried out using a continuous wave (CW) beam of an Argon laser. For lateral stability the beam had a intensity minimum along its axis. Calculations of the optical radiation force on an SBSL bubble indicate that ion laser technology is a poor choice for providing the magnitude of the average optical radiation force required. Consequently it is necessary to examine various diode-pumped solid state laser technologies. The approach for this part of the research will be to achieve optical levitation of a quiescent bubble based on contemporary laser technology and then to strobe the laser synchronously with the SBSL bubble oscillations.