National Library of Energy BETA

Sample records for ionizing radiation ir

  1. Biological Effects of Ionizing Radiation

    DOE R&D Accomplishments [OSTI]

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

    1952-04-07

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

  2. Ionizing radiation detector

    DOE Patents [OSTI]

    Thacker, Louis H.

    1990-01-01

    An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

  3. Lesson 4 - Ionizing Radiation | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    4 - Ionizing Radiation Lesson 4 - Ionizing Radiation Lesson Three showed that unstable isotopes emit energy as they become more stable. This energy is known as radiation. This lesson explores forms of radiation, where radiation is found, how we detect and measure radiation, what sources of radiation people are exposed to, whether radiation is harmful, and how we can limit our exposure. Specific topics covered in this lesson include: Types of radiation Non-ionizing Ionizing Forms of ionizing

  4. Down-regulation of PERK enhances resistance to ionizing radiation

    SciTech Connect (OSTI)

    Oommen, Deepu Prise, Kevin M.

    2013-11-08

    Highlights: •PERK enhances the sensitivity of cancer cells to ionizing radiation. •Down-regulation of PERK results in enhanced DNA repair. •Ionizing radiation-induced apoptosis is inhibited in PERK-down regulated cancer cells. -- Abstract: Although, ionizing radiation (IR) has been implicated to cause stress in endoplasmic reticulum (ER), how ER stress signaling and major ER stress sensors modulate cellular response to IR is unclear. Protein kinase RNA-like endoplasmic reticulum kinase (PERK) is an ER transmembrane protein which initiates unfolded protein response (UPR) or ER stress signaling when ER homeostasis is disturbed. Here, we report that down-regulation of PERK resulted in increased clonogenic survival, enhanced DNA repair and reduced apoptosis in irradiated cancer cells. Our study demonstrated that PERK has a role in sensitizing cancer cells to IR.

  5. Evolution of extreme resistance to ionizing radiation via genetic...

    Office of Scientific and Technical Information (OSTI)

    Published Article: Evolution of extreme resistance to ionizing radiation via genetic adaptation of DNA repair Prev Next Title: Evolution of extreme resistance to ionizing ...

  6. Composite scintillators for detection of ionizing radiation

    DOE Patents [OSTI]

    Dai, Sheng [Knoxville, TN; Stephan, Andrew Curtis [Knoxville, TN; Brown, Suree S [Knoxville, TN; Wallace, Steven A [Knoxville, TN; Rondinone, Adam J [Knoxville, TN

    2010-12-28

    Applicant's present invention is a composite scintillator having enhanced transparency for detecting ionizing radiation comprising a material having optical transparency wherein said material comprises nano-sized objects having a size in at least one dimension that is less than the wavelength of light emitted by the composite scintillator wherein the composite scintillator is designed to have selected properties suitable for a particular application.

  7. Genetic variation in resistance to ionizing radiation

    SciTech Connect (OSTI)

    Ayala, F.J.

    1989-01-01

    The very reactive superoxide anion O[sub 2] is generated during cell respiration as well as during exposure to ionizing radiation. Organisms have evolved different mechanisms to protect against the deleterious effects of reduced oxygen species. The copper-zinc superoxide dismutase is a eukaryotic cytoplasmic enzyme that protects the cell by scavenging superoxide radicals and dismutating them to hydrogen peroxide and molecular oxygen: 20[sub 2][sup [minus

  8. Alloy nanoparticle synthesis using ionizing radiation

    DOE Patents [OSTI]

    Nenoff, Tina M.; Powers, Dana A.; Zhang, Zhenyuan

    2011-08-16

    A method of forming stable nanoparticles comprising substantially uniform alloys of metals. A high dose of ionizing radiation is used to generate high concentrations of solvated electrons and optionally radical reducing species that rapidly reduce a mixture of metal ion source species to form alloy nanoparticles. The method can make uniform alloy nanoparticles from normally immiscible metals by overcoming the thermodynamic limitations that would preferentially produce core-shell nanoparticles.

  9. Waveshifters and Scintillators for Ionizing Radiation Detection

    SciTech Connect (OSTI)

    B.Baumgaugh; J.Bishop; D.Karmgard; J.Marchant; M.McKenna; R.Ruchti; M.Vigneault; L.Hernandez; C.Hurlbut

    2007-12-11

    Scintillation and waveshifter materials have been developed for the detection of ionizing radiation in an STTR program between Ludlum Measurements, Inc. and the University of Notre Dame. Several new waveshifter materials have been developed which are comparable in efficiency and faster in fluorescence decay than the standard material Y11 (K27) used in particle physics for several decades. Additionally, new scintillation materials useful for fiber tracking have been developed which have been compared to 3HF. Lastly, work was done on developing liquid scintillators and paint-on scintillators and waveshifters for high radiation environments.

  10. Identifying the Proteins that Mediate the Ionizing Radiation Resistance of Deinococcus Radiodurans R1

    SciTech Connect (OSTI)

    Battista, John R

    2010-02-22

    The primary objectives of this proposal was to define the subset of proteins required for the ionizing radiation (IR) resistance of Deinococcus radiodurans R1, characterize the activities of those proteins, and apply what was learned to problems of interest to the Department of Energy.

  11. Method and apparatus to monitor a beam of ionizing radiation

    SciTech Connect (OSTI)

    Blackburn, Brandon W.; Chichester, David L.; Watson, Scott M.; Johnson, James T.; Kinlaw, Mathew T.

    2015-06-02

    Methods and apparatus to capture images of fluorescence generated by ionizing radiation and determine a position of a beam of ionizing radiation generating the fluorescence from the captured images. In one embodiment, the fluorescence is the result of ionization and recombination of nitrogen in air.

  12. Dwarf Galaxies with Ionizing Radiation Feedback II: Spatially...

    Office of Scientific and Technical Information (OSTI)

    Star Formation Relation Citation Details In-Document Search Title: Dwarf Galaxies with Ionizing Radiation Feedback II: Spatially-resolved Star Formation Relation Authors: Kim, ...

  13. Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation

    SciTech Connect (OSTI)

    Nicolay, Nils H.; Sommer, Eva; Lopez, Ramon; Wirkner, Ute; Trinh, Thuy; Sisombath, Sonevisay; Debus, Jrgen; Ho, Anthony D.; Saffrich, Rainer; Huber, Peter E.

    2013-12-01

    Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression.

  14. Radiation and ionization energy loss simulation for the GDH sum...

    Office of Scientific and Technical Information (OSTI)

    loss simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab Citation Details In-Document Search Title: Radiation and ionization energy loss simulation for the ...

  15. Genetic variation in resistance to ionizing radiation. [Annual report, 1989

    SciTech Connect (OSTI)

    Ayala, F.J.

    1989-12-31

    The very reactive superoxide anion O{sub 2} is generated during cell respiration as well as during exposure to ionizing radiation. Organisms have evolved different mechanisms to protect against the deleterious effects of reduced oxygen species. The copper-zinc superoxide dismutase is a eukaryotic cytoplasmic enzyme that protects the cell by scavenging superoxide radicals and dismutating them to hydrogen peroxide and molecular oxygen: 20{sub 2}{sup {minus}} + 2H {yields} H{sub 2}O{sub 2} + O{sub 2}. SOD had been shown to protect against ionizing radiation damage to DNA, viruses, bacteria, mammalian cells, whole mice, and Drosophila. Evidence that genetic differences may affect sensitivity to ionizing radiation has been shown in Drosophila since differences have been shown to exist between strains and resistance to radiation can evolve under natural selection.

  16. MicroRNA Regulation of Ionizing Radiation-Induced Premature Senescence

    SciTech Connect (OSTI)

    Wang Yong; Scheiber, Melissa N.; Neumann, Carola; Calin, George A.; Zhou Daohong

    2011-11-01

    Purpose: MicroRNAs (miRNAs) have emerged as critical regulators of many cellular pathways. Ionizing radiation (IR) exposure causes DNA damage and induces premature senescence. However, the role of miRNAs in IR-induced senescence has not been well defined. Thus, the purpose of this study was to identify and characterize senescence-associated miRNAs (SA-miRNAs) and to investigate the role of SA-miRNAs in IR-induced senescence. Methods and Materials: In human lung (WI-38) fibroblasts, premature senescence was induced either by IR or busulfan (BU) treatment, and replicative senescence was accomplished by serial passaging. MiRNA microarray were used to identify SA-miRNAs, and real-time reverse transcription (RT)-PCR validated the expression profiles of SA-miRNAs in various senescent cells. The role of SA-miRNAs in IR-induced senescence was characterized by knockdown of miRNA expression, using anti-miRNA oligonucleotides or by miRNA overexpression through the transfection of pre-miRNA mimics. Results: We identified eight SA-miRNAs, four of which were up-regulated (miR-152, -410, -431, and -493) and four which were down-regulated (miR-155, -20a, -25, and -15a), that are differentially expressed in both prematurely senescent (induced by IR or BU) and replicatively senescent WI-38 cells. Validation of the expression of these SA-miRNAs indicated that down-regulation of miR-155, -20a, -25, and -15a is a characteristic miRNA expression signature of cellular senescence. Functional analyses revealed that knockdown of miR-155 or miR-20a, but not miR-25 or miR-15a, markedly enhanced IR-induced senescence, whereas ectopic overexpression of miR-155 or miR-20a significantly inhibited senescence induction. Furthermore, our studies indicate that miR-155 modulates IR-induced senescence by acting downstream of the p53 and p38 mitogen-activated protein kinase (MAPK) pathways and in part via regulating tumor protein 53-induced nuclear protein 1 (TP53INP1) expression. Conclusion: Our

  17. Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells

    SciTech Connect (OSTI)

    Lee, Eun Sang; Lee, Hae-June; Lee, Yoon-Jin; Jeong, Jae-Hoon; Kang, Seongman; Lim, Young-Bin

    2014-07-25

    Highlights: UPR activation precedes caspase activation in irradiated IEC-6 cells. Chemical ER stress inducers radiosensitize IEC-6 cells. siRNAs that targeted ER stress responses ameliorate IR-induced cell death. Chemical chaperons prevent cell death in irradiated IEC-6 cells. - Abstract: Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.

  18. Effects of ionizing radiation on modern ion exchange materials

    SciTech Connect (OSTI)

    Marsh, S.F.; Pillay, K.K.S.

    1993-10-01

    We review published studies of the effects of ionizing radiation on ion exchange materials, emphasizing those published in recent years. A brief overview is followed by a more detailed examination of recent developments. Our review includes styrene/divinylbenzene copolymers with cation-exchange or anion-exchange functional groups, polyvinylpyridine anion exchangers, chelating resins, multifunctional resins, and inorganic exchangers. In general, strong-acid cation exchange resins are more resistant to radiation than are strong-base anion exchange resins, and polyvinylpyridine resins are more resistant than polystyrene resins. Cross-linkage, salt form, moisture content, and the surrounding medium all affect the radiation stability of a specific exchanger. Inorganic exchangers usually, but not always, exhibit high radiation resistance. Liquid ion exchangers, which have been used so extensively in nuclear processing applications, also are included.

  19. Organic materials and devices for detecting ionizing radiation

    DOE Patents [OSTI]

    Doty, F. Patrick; Chinn, Douglas A.

    2007-03-06

    A .pi.-conjugated organic material for detecting ionizing radiation, and particularly for detecting low energy fission neutrons. The .pi.-conjugated materials comprise a class of organic materials whose members are intrinsic semiconducting materials. Included in this class are .pi.-conjugated polymers, polyaromatic hydrocarbon molecules, and quinolates. Because of their high resistivities (.gtoreq.10.sup.9 ohmcm), these .pi.-conjugated organic materials exhibit very low leakage currents. A device for detecting and measuring ionizing radiation can be made by applying an electric field to a layer of the .pi.-conjugated polymer material to measure electron/hole pair formation. A layer of the .pi.-conjugated polymer material can be made by conventional polymer fabrication methods and can be cast into sheets capable of covering large areas. These sheets of polymer radiation detector material can be deposited between flexible electrodes and rolled up to form a radiation detector occupying a small volume but having a large surface area. The semiconducting polymer material can be easily fabricated in layers about 10 .mu.m to 100 .mu.m thick. These thin polymer layers and their associated electrodes can be stacked to form unique multi-layer detector arrangements that occupy small volume.

  20. FT-IR microscopical analysis with synchrotron radiation: The microscope optics and system performance

    SciTech Connect (OSTI)

    Reffner, J.A.; Martoglio, P.A.; Williams, G.P.

    1995-01-01

    When a Fourier transform infrared (FT-IR) microspectrometer was first interfaced with the National Synchrotron Light Source (NSLS) in September 1993, there was an instant realization that the performance at the diffraction limit had increased 40-100 times. The synchrotron source transformed the IR microspectrometer into a true IR microprobe, providing high-quality IR spectra for probe diameters at the diffraction limit. The combination of IR microspectroscopy and synchrotron radiation provides a powerful new tool for molecular spectroscopy. The ability to perform IR microspectroscopy with synchrotron radiation is still under development at Brookhaven National Laboratory, but several initial studies have been completed that demonstrate the broad-ranging applications of this technology and its potential for materials characterization.

  1. Optical remote diagnostics of atmospheric propagating beams of ionizing radiation

    DOE Patents [OSTI]

    Karl, Jr., Robert R. (Los Alamos, NM)

    1990-01-01

    Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

  2. DWARF GALAXIES WITH IONIZING RADIATION FEEDBACK. I. ESCAPE OF IONIZING PHOTONS

    SciTech Connect (OSTI)

    Kim, Ji-hoon; Krumholz, Mark R.; Goldbaum, Nathan J.; Wise, John H.; Turk, Matthew J.; Abel, Tom

    2013-10-01

    We describe a new method for simulating ionizing radiation and supernova feedback in the analogs of low-redshift galactic disks. In this method, which we call star-forming molecular cloud (SFMC) particles, we use a ray-tracing technique to solve the radiative transfer equation for ultraviolet photons emitted by thousands of distinct particles on the fly. Joined with high numerical resolution of 3.8 pc, the realistic description of stellar feedback helps to self-regulate star formation. This new feedback scheme also enables us to study the escape of ionizing photons from star-forming clumps and from a galaxy, and to examine the evolving environment of star-forming gas clumps. By simulating a galactic disk in a halo of 2.3 10{sup 11} M{sub ?}, we find that the average escape fraction from all radiating sources on the spiral arms (excluding the central 2.5 kpc) fluctuates between 0.08% and 5.9% during a ?20 Myr period with a mean value of 1.1%. The flux of escaped photons from these sources is not strongly beamed, but manifests a large opening angle of more than 60 from the galactic pole. Further, we investigate the escape fraction per SFMC particle, f{sub esc}(i), and how it evolves as the particle ages. We discover that the average escape fraction f{sub esc} is dominated by a small number of SFMC particles with high f{sub esc}(i). On average, the escape fraction from an SFMC particle rises from 0.27% at its birth to 2.1% at the end of a particle lifetime, 6 Myr. This is because SFMC particles drift away from the dense gas clumps in which they were born, and because the gas around the star-forming clumps is dispersed by ionizing radiation and supernova feedback. The framework established in this study brings deeper insight into the physics of photon escape fraction from an individual star-forming clump and from a galactic disk.

  3. Modeling of ionizing radiation effects in short-channel MOSFETs

    SciTech Connect (OSTI)

    Wilson, C.L.; Blue, J.L.

    1982-12-01

    The effect of ionizing radiation on short-channel MOSFETs is modeled using a charge-sheet approach. The primary effect of ionizing radiation is the introduction of oxide trapped charge (OTC) and interface trapped charge (ITC). Using a two-dimensional charge-sheet model, transistors with channel lengths between 4.65 ..mu..m and 0.27 ..mu..m were studied. A range of net OTC and ITC values of + 4.0 X 10/sup 11/ cm/sup -2/ corresponding to a dose of approximately 10/sup 6/ rad (SiO/sub 2/) was used to study total dose effects. ITC and OTC cause significant effects in each region of operation. In the subthreshold region, the sensitivity of drain current to these charges is exponential. A more realistic model must include the energy distribution of the ITC charge as well as two-dimensional charge sharing effects. In the triode region, the effects of ITC and OTC are indistinguishable from two-dimensional charge sharing effects.

  4. Review of using gallium nitride for ionizing radiation detection

    SciTech Connect (OSTI)

    Wang, Jinghui; Mulligan, Padhraic; Cao, Lei R.; Brillson, Leonard

    2015-09-15

    With the largest band gap energy of all commercial semiconductors, GaN has found wide application in the making of optoelectronic devices. It has also been used for photodetection such as solar blind imaging as well as ultraviolet and even X-ray detection. Unsurprisingly, the appreciable advantages of GaN over Si, amorphous silicon (a-Si:H), SiC, amorphous SiC (a-SiC), and GaAs, particularly for its radiation hardness, have drawn prompt attention from the physics, astronomy, and nuclear science and engineering communities alike, where semiconductors have traditionally been used for nuclear particle detection. Several investigations have established the usefulness of GaN for alpha detection, suggesting that when properly doped or coated with neutron sensitive materials, GaN could be turned into a neutron detection device. Work in this area is still early in its development, but GaN-based devices have already been shown to detect alpha particles, ultraviolet light, X-rays, electrons, and neutrons. Furthermore, the nuclear reaction presented by {sup 14}N(n,p){sup 14}C and various other threshold reactions indicates that GaN is intrinsically sensitive to neutrons. This review summarizes the state-of-the-art development of GaN detectors for detecting directly and indirectly ionizing radiation. Particular emphasis is given to GaN's radiation hardness under high-radiation fields.

  5. Cardiovascular Risks Associated with Low Dose Ionizing Particle Radiation

    SciTech Connect (OSTI)

    Yan, Xinhua; Sasi, Sharath P.; Gee, Hannah; Lee, JuYong; Yang, Yongyao; Mehrzad, Raman; Onufrak, Jillian; Song, Jin; Enderling, Heiko; Agarwal, Akhil; Rahimi, Layla; Morgan, James; Wilson, Paul F.; Carrozza, Joseph; Walsh, Kenneth; Kishore, Raj; Goukassian, David A.

    2014-10-22

    Previous epidemiologic data demonstrate that cardiovascular (CV) morbidity and mortality may occur decades after ionizing radiation exposure. With increased use of proton and carbon ion radiotherapy and concerns about space radiation exposures to astronauts on future long-duration exploration-type missions, the long-term effects and risks of low-dose charged particle irradiation on the CV system must be better appreciated. Here we report on the long-term effects of whole-body proton (1H; 0.5 Gy, 1 GeV) and iron ion (56Fe; 0.15 Gy, 1GeV/nucleon) irradiation with and without an acute myocardial ischemia (AMI) event in mice. We show that cardiac function of proton-irradiated mice initially improves at 1 month but declines by 10 months post-irradiation. In AMI-induced mice, prior proton irradiation improved cardiac function restoration and enhanced cardiac remodeling. This was associated with increased pro-survival gene expression in cardiac tissues. In contrast, cardiac function was significantly declined in 56Fe ion-irradiated mice at 1 and 3 months but recovered at 10 months. In addition, 56Fe ion-irradiation led to poorer cardiac function and more adverse remodeling in AMI-induced mice, and was associated with decreased angiogenesis and pro-survival factors in cardiac tissues at any time point examined up to 10 months. This is the first study reporting CV effects following low dose proton and iron ion irradiation during normal aging and post-AMI. Finally, understanding the biological effects of charged particle radiation qualities on the CV system is necessary both for the mitigation of space exploration CV risks and for understanding of long-term CV effects following charged particle radiotherapy.

  6. Cardiovascular Risks Associated with Low Dose Ionizing Particle Radiation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yan, Xinhua; Sasi, Sharath P.; Gee, Hannah; Lee, JuYong; Yang, Yongyao; Mehrzad, Raman; Onufrak, Jillian; Song, Jin; Enderling, Heiko; Agarwal, Akhil; et al

    2014-10-22

    Previous epidemiologic data demonstrate that cardiovascular (CV) morbidity and mortality may occur decades after ionizing radiation exposure. With increased use of proton and carbon ion radiotherapy and concerns about space radiation exposures to astronauts on future long-duration exploration-type missions, the long-term effects and risks of low-dose charged particle irradiation on the CV system must be better appreciated. Here we report on the long-term effects of whole-body proton (1H; 0.5 Gy, 1 GeV) and iron ion (56Fe; 0.15 Gy, 1GeV/nucleon) irradiation with and without an acute myocardial ischemia (AMI) event in mice. We show that cardiac function of proton-irradiated mice initiallymore » improves at 1 month but declines by 10 months post-irradiation. In AMI-induced mice, prior proton irradiation improved cardiac function restoration and enhanced cardiac remodeling. This was associated with increased pro-survival gene expression in cardiac tissues. In contrast, cardiac function was significantly declined in 56Fe ion-irradiated mice at 1 and 3 months but recovered at 10 months. In addition, 56Fe ion-irradiation led to poorer cardiac function and more adverse remodeling in AMI-induced mice, and was associated with decreased angiogenesis and pro-survival factors in cardiac tissues at any time point examined up to 10 months. This is the first study reporting CV effects following low dose proton and iron ion irradiation during normal aging and post-AMI. Finally, understanding the biological effects of charged particle radiation qualities on the CV system is necessary both for the mitigation of space exploration CV risks and for understanding of long-term CV effects following charged particle radiotherapy.« less

  7. Ionizing radiation predisposes non-malignant human mammaryepithelial cells to undergo TGF beta-induced epithelial to mesenchymaltransition

    SciTech Connect (OSTI)

    Andarawewa, Kumari L.; Erickson, Anna C.; Chou, William S.; Costes, Sylvain; Gascard, Philippe; Mott, Joni D.; Bissell, Mina J.; Barcellos-Hoff, Mary Helen

    2007-04-06

    Transforming growth factor {beta}1 (TGF{beta}) is a tumor suppressor during the initial stage of tumorigenesis, but it can switch to a tumor promoter during neoplastic progression. Ionizing radiation (IR), both a carcinogen and a therapeutic agent, induces TGF{beta}, activation in vivo. We now show that IR sensitizes human mammary epithelial cells (HMEC) to undergo TGF{beta}-mediated epithelial to mesenchymal transition (EMT). Non-malignant HMEC (MCF10A, HMT3522 S1 and 184v) were irradiated with 2 Gy shortly after attachment in monolayer culture, or treated with a low concentration of TGF{beta} (0.4 ng/ml), or double-treated. All double-treated (IR+TGF{beta}) HMEC underwent a morphological shift from cuboidal to spindle-shaped. This phenotype was accompanied by decreased expression of epithelial markers E-cadherin, {beta}-catenin and ZO-1, remodeling of the actin cytoskeleton, and increased expression of mesenchymal markers N-cadherin, fibronectin and vimentin. Furthermore, double-treatment increased cell motility, promoted invasion and disrupted acinar morphogenesis of cells subsequently plated in Matrigel{trademark}. Neither radiation nor TGF{beta} alone elicited EMT, even though IR increased chronic TGF{beta} signaling and activity. Gene expression profiling revealed that double treated cells exhibit a specific 10-gene signature associated with Erk/MAPK signaling. We hypothesized that IR-induced MAPK activation primes non-malignant HMEC to undergo TGF{beta}-mediated EMT. Consistent with this, Erk phosphorylation were transiently induced by irradiation, persisted in irradiated cells treated with TGF{beta}, and treatment with U0126, a Mek inhibitor, blocked the EMT phenotype. Together, these data demonstrate that the interactions between radiation-induced signaling pathways elicit heritable phenotypes that could contribute to neoplastic progression.

  8. Ionizing radiation post-curing of objects produced by stereolithography and other methods

    DOE Patents [OSTI]

    Howell, David H.; Eberle, Claude C.; Janke, Christopher J.

    2000-01-01

    An object comprised of a curable material and formed by stereolithography or another three-dimensional prototyping method, in which the object has undergone initial curing, is subjected to post-curing by ionizing radiation, such as an electron beam having a predetermined beam output energy, which is applied in a predetermined dosage and at a predetermined dose rate. The post-cured object exhibits a property profile which is superior to that which existed prior to the ionizing radiation post-curing.

  9. The susceptibility of TaOx-based memristors to high dose rate ionizing radiation and total ionizing dose

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    McLain, Michael Lee; Sheridan, Timothy J.; Hjalmarson, Harold Paul; Mickel, Patrick R.; Hanson, Donald J.; McDonald, Joseph K.; Hughart, David Russell; Marinella, Matthew J.

    2014-11-11

    This paper investigates the effects of high dose rate ionizing radiation and total ionizing dose (TID) on tantalum oxide (TaOx) memristors. Transient data were obtained during the pulsed exposures for dose rates ranging from approximately 5.0 ×107 rad(Si)/s to 4.7 ×108 rad(Si)/s and for pulse widths ranging from 50 ns to 50 μs. The cumulative dose in these tests did not appear to impact the observed dose rate response. Static dose rate upset tests were also performed at a dose rate of ~3.0 ×108 rad(Si)/s. This is the first dose rate study on any type of memristive memory technology. Inmore » addition to assessing the tolerance of TaOx memristors to high dose rate ionizing radiation, we also evaluated their susceptibility to TID. The data indicate that it is possible for the devices to switch from a high resistance off-state to a low resistance on-state in both dose rate and TID environments. The observed radiation-induced switching is dependent on the irradiation conditions and bias configuration. Furthermore, the dose rate or ionizing dose level at which a device switches resistance states varies from device to device; the enhanced susceptibility observed in some devices is still under investigation. As a result, numerical simulations are used to qualitatively capture the observed transient radiation response and provide insight into the physics of the induced current/voltages.« less

  10. High and Low Doses of Ionizing Radiation Induce Different Secretome Profiles in a Human Skin Model

    SciTech Connect (OSTI)

    Zhang, Qibin; Matzke, Melissa M.; Schepmoes, Athena A.; Moore, Ronald J.; Webb-Robertson, Bobbie-Jo M.; Hu, Zeping; Monroe, Matthew E.; Qian, Weijun; Smith, Richard D.; Morgan, William F.

    2014-03-18

    It is postulated that secreted soluble factors are important contributors of bystander effect and adaptive responses observed in low dose ionizing radiation. Using multidimensional liquid chromatography-mass spectrometry based proteomics, we quantified the changes of skin tissue secretome the proteins secreted from a full thickness, reconstituted 3-dimensional skin tissue model 48 hr after exposure to 3, 10 and 200 cGy of X-rays. Overall, 135 proteins showed statistical significant difference between the sham (0 cGy) and any of the irradiated groups (3, 10 or 200 cGy) on the basis of Dunnett adjusted t-test; among these, 97 proteins showed a trend of downregulation and 9 proteins showed a trend of upregulation with increasing radiation dose. In addition, there were 21 and 8 proteins observed to have irregular trends with the 10 cGy irradiated group either having the highest or the lowest level among all three radiated doses. Moreover, two proteins, carboxypeptidase E and ubiquitin carboxyl-terminal hydrolase isozyme L1 were sensitive to ionizing radiation, but relatively independent of radiation dose. Conversely, proteasome activator complex subunit 2 protein appeared to be sensitive to the dose of radiation, as rapid upregulation of this protein was observed when radiation doses were increased from 3, to 10 or 200 cGy. These results suggest that different mechanisms of action exist at the secretome level for low and high doses of ionizing radiation.

  11. Non-Targeted Effects of Ionizing Radiation: Implications for Risk Assessment and the Radiation Dose Response Profile

    SciTech Connect (OSTI)

    Morgan, William F.; Sowa, Marianne B.

    2009-11-01

    Radiation risks at low doses remain a hotly debated topic. Recent experimental advances in our understanding of effects occurring in the progeny of irradiated cells, and/or the non-irradiated neighbors of irradiated cells, i.e., non-targeted effects associated with exposure to ionizing radiation, have influenced this debate. The goal of this document is to summarize the current status of this debate and speculate on the potential impact of non-targeted effects on radiation risk assessment and the radiation dose response profile.

  12. Measurement of absorbed dose-to-water for an HDR {sup 192}Ir source with ionization chambers in a sandwich setup

    SciTech Connect (OSTI)

    Araki, Fujio; Kouno, Tomohiro; Ohno, Takeshi; Kakei, Kiyotaka; Yoshiyama, Fumiaki; Kawamura, Shinji

    2013-09-15

    Purpose: In this study, a dedicated device for ion chamber measurements of absorbed dose-to-water for a Nucletron microSelectron-v2 HDR {sup 192}Ir brachytherapy source is presented. The device uses two ionization chambers in a so-called sandwich assembly. Using this setup and by taking the average reading of the two chambers, any dose error due to difficulties in absolute positioning (centering) of the source in between the chambers is cancelled to first order. The method's accuracy was examined by comparing measurements with absorbed dose-to-water determination based on the AAPM TG-43 protocol.Methods: The optimal source-to-chamber distance (SCD) for {sup 192}Ir dosimetry was determined from ion chamber measurements in a water phantom. The {sup 192}Ir source was sandwiched between two Exradin A1SL chambers (0.057 cm{sup 3}) at the optimal SCD separation. The measured ionization was converted to the absorbed dose-to-water using a {sup 60}Co calibration factor and a Monte Carlo-calculated beam quality conversion factor, k{sub Q}, for {sup 60}Co to {sup 192}Ir. An uncertainty estimate of the proposed method was determined based on reproducibility of measurements at different institutions for the same type of source.Results: The optimal distance for the A1SL chamber measurements was determined to be 5 cm from the {sup 192}Ir source center, considering the depth dependency of k{sub Q} for {sup 60}Co to {sup 192}Ir and the chamber positioning. The absorbed dose to water measured at (5 cm, 90°) on the transverse axis was 1.3% lower than TG-43 values and its reproducibility and overall uncertainty were 0.8% and 1.7%, respectively. The measurement doses at anisotropic points agreed within 1.5% with TG-43 values.Conclusions: The ion chamber measurement of absorbed dose-to-water with a sandwich method for the {sup 192}Ir source provides a more accurate, direct, and reference dose compared to the dose-to-water determination based on air-kerma strength in the TG-43 protocol

  13. Knockdown of TWIST1 enhances arsenic trioxide- and ionizing radiation-induced cell death in lung cancer cells by promoting mitochondrial dysfunction

    SciTech Connect (OSTI)

    Seo, Sung-Keum; Kim, Jae-Hee; Choi, Ha-Na; Choe, Tae-Boo; Hong, Seok-Il; Yi, Jae-Youn; Hwang, Sang-Gu; Lee, Hyun-Gyu; Lee, Yun-Han; Park, In-Chul

    2014-07-11

    Highlights: • Knockdown of TWIST1 enhanced ATO- and IR-induced cell death in NSCLCs. • Intracellular ROS levels were increased in cells treated with TWIST1 siRNA. • TWIST1 siRNA induced MMP loss and mitochondrial fragmentation. • TWIST1 siRNA upregulated the fission-related proteins FIS1 and DRP1. - Abstract: TWIST1 is implicated in the process of epithelial mesenchymal transition, metastasis, stemness, and drug resistance in cancer cells, and therefore is a potential target for cancer therapy. In the present study, we found that knockdown of TWIST1 by small interfering RNA (siRNA) enhanced arsenic trioxide (ATO)- and ionizing radiation (IR)-induced cell death in non-small-cell lung cancer cells. Interestingly, intracellular reactive oxygen species levels were increased in cells treated with TWIST1 siRNA and further increased by co-treatment with ATO or IR. Pretreatment of lung cancer cells with the antioxidant N-acetyl-cysteine markedly suppressed the cell death induced by combined treatment with TWIST1 siRNA and ATO or IR. Moreover, treatment of cells with TWIST1 siRNA induced mitochondrial membrane depolarization and significantly increased mitochondrial fragmentation (fission) and upregulated the fission-related proteins FIS1 and DRP1. Collectively, our results demonstrate that siRNA-mediated TWIST1 knockdown induces mitochondrial dysfunction and enhances IR- and ATO-induced cell death in lung cancer cells.

  14. Detailed Investigations of Interactions between Ionizing Radiation and Neutral Gases

    SciTech Connect (OSTI)

    Landers, Allen L

    2014-03-31

    We are investigating phenomena that stem from the many body dynamics associated with ionization of an atom or molecule by photon or charged particle. Our program is funded through the Department of Energy EPSCoR Laboratory Partnership Award in collaboration with Lawrence Berkeley National Laboratory. We are using variations on the well established COLTRIMS technique to measure ions and electrons ejected during these interactions. Photoionization measurements take place at the Advanced Light Source at LBNL as part of the ALS-COLTRIMS collaboration with the groups of Reinhard Dörner at Frankfurt and Ali Belkacem at LBNL. Additional experiments on charged particle impact are conducted locally at Auburn University where we are studying the dissociative molecular dynamics following interactions with either ions or electrons over a velocity range of 1 to 12 atomic units.

  15. Effect of focal geometry on radiation from atomic ionization in an ultrastrong and ultrafast laser field

    SciTech Connect (OSTI)

    Ghebregziabher, Isaac; Walker, Barry C.

    2007-08-15

    We use a tunneling-Monte Carlo model to calculate the dynamics and emitted Larmor radiation from electrons ionized in an ultrashort and ultrastrong pulsed laser focus over the intensity range from 10{sup 17} to 10{sup 20} W/cm{sup 2}. We find the spatial variation of a laser field affects the radiation and can no longer be neglected at laser intensities leading to relativistic effects. We identify three regimes for the interaction as a function of the ratio of the single cycle quiver amplitude of the photoelectron to the laser focus waist. Adopting a one-dimensional or plane wave approximation when the laser driven excursion of the photoelectron exceeds the focus waist overestimates the total radiated energy by as much as an order of magnitude. Despite this, the spectral amplitude of the highest-energy photons from ionization in a laser focus is comparable to the plane wave case for excursions up to the beam waist since the laser focus imparts an extra boost of speed for electrons exiting the focus. Full spatial and temporal integration that includes the ionization of charge states before the peak of the pulse do not differ significantly from results that include only the radiation from ionization of the charge state at the peak of the laser field.

  16. Mammalian Tissue Response to Low Dose Ionizing Radiation: The Role of Oxidative Metabolism and Intercellular Communication

    SciTech Connect (OSTI)

    Azzam, Edouard I

    2013-01-16

    The objective of the project was to elucidate the mechanisms underlying the biological effects of low dose/low dose rate ionizing radiation in organs/tissues of irradiated mice that differ in their susceptibility to ionizing radiation, and in human cells grown under conditions that mimic the natural in vivo environment. The focus was on the effects of sparsely ionizing cesium-137 gamma rays and the role of oxidative metabolism and intercellular communication in these effects. Four Specific Aims were proposed. The integrated outcome of the experiments performed to investigate these aims has been significant towards developing a scientific basis to more accurately estimate human health risks from exposures to low doses ionizing radiation. By understanding the biochemical and molecular changes induced by low dose radiation, several novel markers associated with mitochondrial functions were identified, which has opened new avenues to investigate metabolic processes that may be affected by such exposure. In particular, a sensitive biomarker that is differentially modulated by low and high dose gamma rays was discovered.

  17. Apparatus and method for the simultaneous detection of neutrons and ionizing electromagnetic radiation

    DOE Patents [OSTI]

    Bell, Zane W.

    2000-01-01

    A sensor for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising: a sensor for the detection of gamma radiation, the sensor defining a sensing head; the sensor further defining an output end in communication with the sensing head; and an exterior neutron-sensitive material configured to form around the sensing head; wherein the neutron-sensitive material, subsequent to the capture of the neutron, fissions into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the first excited state decaying via the emission of a single gamma ray at 478 keV which can in turn be detected by the sensing head; and wherein the sensing head can also detect the ionizing electromagnetic radiation from an incident radiation field without significant interference from the neutron-sensitive material. A method for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising the steps of: providing a gamma ray sensitive detector comprising a sensing head and an output end; conforming an exterior neutron-sensitive material configured to form around the sensing head of the detector; capturing neutrons by the sensing head causing the neutron-sensitive material to fission into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the state decaying via the emission of a single gamma ray at 478 keV; sensing gamma rays entering the detector through the neutron-sensitive material; and producing an output through a readout device coupled to the output end; wherein the detector provides an output which is proportional to the energy of the absorbed ionizing electromagnetic radiation.

  18. Bikini Atoll ionizing radiation survey, May 1985-May 1986

    SciTech Connect (OSTI)

    Shingleton, K.L.; Cate, J.L.; Trent, M.G.; Robison, W.L.

    1987-10-01

    Between 1946 and 1958, the United States conducted 23 nuclear tests at the Bikini Atoll in the Marshall Islands, which resulted in extensive radioactive contamination of a number of islands in the atoll and prevented the timely resettlement of the native population. Although the external dose rates from beta and gamma radiation have been previously determined by aerial survey and a variety of ground measurement techniques, technical constraints limited the assessment of external beta dose rates that result from the /sup 137/Cs and /sup 90/Sr//sup 90/Y contamination on the islands. Now, because of the recent development of very thin thermoluminescent dosimeters (TLDs), the external beta dose rates can be measured. 18 refs., 7 figs., 5 tabs.

  19. Low dose ionizing radiation detection using conjugated polymers

    SciTech Connect (OSTI)

    Silva, E.A.B.; Borin, J.F.; Nicolucci, P.; Graeff, C.F.O.; Netto, T. Ghilardi; Bianchi, R.F.

    2005-03-28

    In this work, the effect of gamma radiation on the optical properties of poly[2-methoxy-5-(2{sup '}-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) is studied. The samples were irradiated at room temperature with different doses from 0 Gy to 152 Gy using a {sup 60}Co gamma ray source. For thin films, significant changes in the UV-visible spectra were only observed at high doses (>1 kGy). In solution, shifts in absorption peaks are observed at low doses (<10 Gy), linearly dependent on dose. The shifts are explained by conjugation reduction, and possible causes are discussed. Our results indicate that MEH-PPV solution can be used as a dosimeter adequate for medical applications.

  20. Technical specifications manual for the MARK-1 pulsed ionizing radiation detection system. Volume 1

    SciTech Connect (OSTI)

    Lawrence, R.S.; Harker, Y.D.; Jones, J.L.; Hoggan, J.M.

    1993-03-01

    The MARK-1 detection system was developed by the Idaho National Engineering Laboratory for the US Department of Energy Office of Arms Control and Nonproliferation. The completely portable system was designed for the detection and analysis of intense photon emissions from pulsed ionizing radiation sources. This manual presents the technical design specifications for the MARK-1 detection system and was written primarily to assist the support or service technician in the service, calibration, and repair of the system. The manual presents the general detection system theory, the MARK-1 component design specifications, the acquisition and control software, the data processing sequence, and the system calibration procedure. A second manual entitled: Volume 2: Operations Manual for the MARK-1 Pulsed Ionizing Radiation Detection System (USDOE Report WINCO-1108, September 1992) provides a general operational description of the MARK-1 detection system. The Operations Manual was written primarily to assist the field operator in system operations and analysis of the data.

  1. The iQID Camera: An Ionizing-Radiation Quantum Imaging Detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Miller, Brian W.; Gregory, Stephanie J.; Fuller, Erin S.; Barrett, Harrison H.; Barber, Bradford H.; Furenlid, Lars R.

    2014-06-11

    We have developed and tested a novel, ionizing-radiation Quantum Imaging Detector (iQID). This scintillation-based detector was originally developed as a high-resolution gamma-ray imager, called BazookaSPECT, for use in single-photon emission computed tomography (SPECT). Recently, we have investigated the detectors response and imaging potential with other forms of ionizing radiation including alpha, neutron, beta, and fission fragment particles. The detector’s response to a broad range of ionizing radiation has prompted its new title. The principle operation of the iQID camera involves coupling a scintillator to an image intensifier. The scintillation light generated particle interactions is optically amplified by the intensifier andmore » then re-imaged onto a CCD/CMOS camera sensor. The intensifier provides sufficient optical gain that practically any CCD/CMOS camera can be used to image ionizing radiation. Individual particles are identified and their spatial position (to sub-pixel accuracy) and energy are estimated on an event-by-event basis in real time using image analysis algorithms on high-performance graphics processing hardware. Distinguishing features of the iQID camera include portability, large active areas, high sensitivity, and high spatial resolution (tens of microns). Although modest, iQID has energy resolution that is sufficient to discrimate between particles. Additionally, spatial features of individual events can be used for particle discrimination. An important iQID imaging application that has recently been developed is single-particle, real-time digital autoradiography. In conclusion, we present the latest results and discuss potential applications.« less

  2. The iQID Camera: An Ionizing-Radiation Quantum Imaging Detector

    SciTech Connect (OSTI)

    Miller, Brian W.; Gregory, Stephanie J.; Fuller, Erin S.; Barrett, Harrison H.; Barber, Bradford H.; Furenlid, Lars R.

    2014-06-11

    We have developed and tested a novel, ionizing-radiation Quantum Imaging Detector (iQID). This scintillation-based detector was originally developed as a high-resolution gamma-ray imager, called BazookaSPECT, for use in single-photon emission computed tomography (SPECT). Recently, we have investigated the detectors response and imaging potential with other forms of ionizing radiation including alpha, neutron, beta, and fission fragment particles. The detector’s response to a broad range of ionizing radiation has prompted its new title. The principle operation of the iQID camera involves coupling a scintillator to an image intensifier. The scintillation light generated particle interactions is optically amplified by the intensifier and then re-imaged onto a CCD/CMOS camera sensor. The intensifier provides sufficient optical gain that practically any CCD/CMOS camera can be used to image ionizing radiation. Individual particles are identified and their spatial position (to sub-pixel accuracy) and energy are estimated on an event-by-event basis in real time using image analysis algorithms on high-performance graphics processing hardware. Distinguishing features of the iQID camera include portability, large active areas, high sensitivity, and high spatial resolution (tens of microns). Although modest, iQID has energy resolution that is sufficient to discrimate between particles. Additionally, spatial features of individual events can be used for particle discrimination. An important iQID imaging application that has recently been developed is single-particle, real-time digital autoradiography. In conclusion, we present the latest results and discuss potential applications.

  3. The iQID Camera An Ionizing-Radiation Quantum Imaging Detector

    SciTech Connect (OSTI)

    Miller, Brian W.; Gregory, Stephanie J.; Fuller, Erin S.; Barrett, Harrison H.; Barber, Bradford H.; Furenlid, Lars R.

    2014-06-11

    Abstract We have developed and tested a novel, ionizing-radiation Quantum Imaging Detector (iQID). This scintillation-based detector was originally developed as a high-resolution gamma-ray imager, called BazookaSPECT, for use in single-photon emission computed tomography (SPECT). Recently, we have investigated the detectors response and imaging potential with other forms of ionizing radiation including alpha, neutron, beta, and fission fragment particles. The detector’s response to a broad range of ionizing radiation has prompted its new title. The principle operation of the iQID camera involves coupling a scintillator to an image intensifier. The scintillation light generated particle interactions is optically amplified by the intensifier and then re-imaged onto a CCD/CMOS camera sensor. The intensifier provides sufficient optical gain that practically any CCD/CMOS camera can be used to image ionizing radiation. Individual particles are identified and their spatial position (to sub-pixel accuracy) and energy are estimated on an event-by-event basis in real time using image analysis algorithms on high-performance graphics processing hardware. Distinguishing features of the iQID camera include portability, large active areas, high sensitivity, and high spatial resolution (tens of microns). Although modest, iQID has energy resolution that is sufficient to discrimate between particles. Additionally, spatial features of individual events can be used for particle discrimination. An important iQID imaging application that has recently been developed is single-particle, real-time digital autoradiography. We present the latest results and discuss potential applications.

  4. Quantitative Proteomic Profiling of Low Dose Ionizing Radiation Effects in a Human Skin Model

    SciTech Connect (OSTI)

    Hengel, Shawna; Aldrich, Joshua T.; Waters, Katrina M.; Pasa-Tolic, Ljiljana; Stenoien, David L.

    2014-07-29

    To assess molecular responses to low doses of radiation that may be encountered during medical diagnostic procedures, nuclear accidents, or terrorist acts, a quantitative global proteomic approach was used to identify protein alterations in a reconstituted human skin tissue treated with 10 cGy of ionizing radiation. Subcellular fractionation was employed to remove highly abundant structural proteins and provide insight on radiation induced alterations in protein abundance and localization. In addition, peptides were post-fractionated using high resolution 2-dimensional liquid chromatography to increase the dynamic range of detection of protein abundance and translocation changes. Quantitative data was obtained by labeling peptides with 8-plex isobaric iTRAQ tags. A total of 207 proteins were detected with statistically significant alterations in abundance and/or subcellular localization compared to sham irradiated tissues. Bioinformatics analysis of the data indicated that the top canonical pathways affected by low dose radiation are related to cellular metabolism. Among the proteins showing alterations in abundance, localization and proteolytic processing was the skin barrier protein filaggrin which is consistent with our previous observation that ionizing radiation alters profilaggrin processing with potential effects on skin barrier functions. In addition, a large number of proteases and protease regulators were affected by low dose radiation exposure indicating that altered proteolytic activity may be a hallmark of low dose radiation exposure. While several studies have demonstrated altered transcriptional regulation occurs following low dose radiation exposures, the data presented here indicates post-transcriptional regulation of protein abundance, localization, and proteolytic processing play an important role in regulating radiation responses in complex human tissues.

  5. RUNAWAY STARS AND THE ESCAPE OF IONIZING RADIATION FROM HIGH-REDSHIFT GALAXIES

    SciTech Connect (OSTI)

    Conroy, Charlie; Kratter, Kaitlin M.

    2012-08-20

    Approximately 30% of all massive stars in the Galaxy are runaways with velocities exceeding 30 km s{sup -1}. Their high speeds allow them to travel {approx}0.1-1 kpc away from their birthplace before they explode at the end of their several Myr lifetimes. At high redshift, when galaxies were much smaller than in the local universe, runaways could venture far from the dense inner regions of their host galaxies. From these large radii, and therefore low column densities, much of their ionizing radiation is able to escape into the intergalactic medium. Runaways may therefore significantly enhance the overall escape fraction of ionizing radiation, f{sub esc}, from small galaxies at high redshift. We present simple models of the high-redshift runaway population and its impact on f{sub esc} as a function of halo mass, size, and redshift. We find that the inclusion of runaways enhances f{sub esc} by factors of Almost-Equal-To 1.1-8, depending on halo mass, galaxy geometry, and the mechanism of runaway production, implying that runaways may contribute 50%-90% of the total ionizing radiation escaping from high-redshift galaxies. Runaways may therefore play an important role in reionizing the universe.

  6. Dried plum diet protects from bone loss caused by ionizing radiation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schreurs, A. -S.; Shirazi-Fard, Y.; Shahnazari, M.; Alwood, J. S.; Truong, T. A.; Tahimic, C. G. T.; Limoli, C. L.; Turner, N. D.; Halloran, B.; Globus, R. K.

    2016-02-11

    Bone loss caused by ionizing radiation is a potential health concern for radiotherapy patients, radiation workers and astronauts. In animal studies, exposure to ionizing radiation increases oxidative damage in skeletal tissues, and results in an imbalance in bone remodeling initiated by increased bone-resorbing osteoclasts. Therefore, we evaluated various candidate interventions with antioxidant or antiinflammatory activities (antioxidant cocktail, dihydrolipoic acid, ibuprofen, dried plum) both for their ability to blunt the expression of resorption-related genes in marrow cells after irradiation with either gamma rays (photons, 2 Gy) or simulated space radiation (protons and heavy ions, 1 Gy) and to prevent bone loss.more » Dried plum was most effective in reducing the expression of genes related to bone resorption (Nfe2l2, Rankl, Mcp1, Opg, TNF-α) and also preventing later cancellous bone decrements caused by irradiation with either photons or heavy ions. Furthermore, dietary supplementation with DP may prevent the skeletal effects of radiation exposures either in space or on Earth.« less

  7. Bystander effects of ionizing radiation can be modulated by signaling amines

    SciTech Connect (OSTI)

    Poon, R.C.C.; Agnihotri, N.; Seymour, C.; Mothersill, C.

    2007-10-15

    Actual risk and risk management of exposure to ionizing radiation are among the most controversial areas in environmental health protection. Recent developments in radiobiology especially characterization of bystander effects have called into question established dogmas and are thought to cast doubt on the scientific basis of the risk assessment framework, leading to uncertainty for regulators and concern among affected populations. In this paper we test the hypothesis that small signaling molecules widely used throughout the animal kingdom for signaling stress or environmental change, such as 5-Hydroxytryptamine (5-HT, serotonin), L-DOPA, glycine or nicotine are involved in bystander signaling processes following ionizing radiation exposure. We report data which suggest that nano to micromolar concentrations of these agents can modulate bystander-induced cell death. Depletion of 5-HT present in tissue culture medium, occurred following irradiation of cells. This suggested that 5-HT might be bound by membrane receptors after irradiation. Expression of 5-HT type 3 receptors which are Ca{sup 2+} ion channels was confirmed in the cells using immunocytochemistry and receptor expression could be increased using radiation or 5-HT exposure. Zofran and Kitryl, inhibitors of 5-HT type 3 receptors, and reserpine a generic serotonin antagonist block the bystander effect induced by radiation or by serotonin. The results may be important for the mechanistic understanding of how low doses of radiation interact with cells to produce biological effects.

  8. Non-Targeted Effects Induced by Ionizing Radiation: Mechanisms and Potential Impact on Radiation Induced Health Effects

    SciTech Connect (OSTI)

    Morgan, William F.; Sowa, Marianne B.

    2015-01-01

    Not-targeted effects represent a paradigm shift from the "DNA centric" view that ionizing radiation only elicits biological effects and subsequent health consequences as a result of an energy deposition event in the cell nucleus. While this is likely true at higher radiation doses (> 1Gy), at low doses (< 100mGy) non-targeted effects associated with radiation exposure might play a significant role. Here definitions of non-targeted effects are presented, the potential mechanisms for the communication of signals and signaling networks from irradiated cells/tissues are proposed, and the various effects of this intra- and intercellular signaling are described. We conclude with speculation on how these observations might lead to and impact long-term human health outcomes.

  9. Radiation and ionization energy loss simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab

    SciTech Connect (OSTI)

    Yan, Xin -Hu; Ye, Yun -Xiu; Chen, Jian -Ping; Lu, Hai -Jiang; Zhu, Peng -Jia; Jiang, Feng -Jian

    2015-07-17

    The radiation and ionization energy loss are presented for single arm Monte Carlo simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab. Radiation and ionization energy loss are discussed for $^{12}C$ elastic scattering simulation. The relative momentum ratio $\\frac{\\Delta p}{p}$ and $^{12}C$ elastic cross section are compared without and with radiation energy loss and a reasonable shape is obtained by the simulation. The total energy loss distribution is obtained, showing a Landau shape for $^{12}C$ elastic scattering. This simulation work will give good support for radiation correction analysis of the GDH sum rule experiment.

  10. Radiation and ionization energy loss simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yan, Xin -Hu; Ye, Yun -Xiu; Chen, Jian -Ping; Lu, Hai -Jiang; Zhu, Peng -Jia; Jiang, Feng -Jian

    2015-07-17

    The radiation and ionization energy loss are presented for single arm Monte Carlo simulation for the GDH sum rule experiment in Hall-A at Jefferson Lab. Radiation and ionization energy loss are discussed formore » $$^{12}C$$ elastic scattering simulation. The relative momentum ratio $$\\frac{\\Delta p}{p}$$ and $$^{12}C$$ elastic cross section are compared without and with radiation energy loss and a reasonable shape is obtained by the simulation. The total energy loss distribution is obtained, showing a Landau shape for $$^{12}C$$ elastic scattering. This simulation work will give good support for radiation correction analysis of the GDH sum rule experiment.« less

  11. Epidemiologic Study of One Million American Workers and Military Veterans Exposed to Ionizing Radiation

    SciTech Connect (OSTI)

    Boice, John D.

    2015-02-27

    A pilot study was completed demonstrating the feasibility of conducting an epidemiologic study assessing cancer and other disease mortality among nearly one million US veterans and workers exposed to ionizing radiation, a population 10 times larger than atomic bomb survivor study with high statistical power to evaluate low dose rate effects. Among the groups enumerated and/or studied were: (1) 194,000 Department of Energy Uranium Workers; (2) 6,700 Rocketdyne Radiation Workers; (3) 7,000 Mound Radiation Workers; (4) 156,000 DOE Plutonium Workers; (5) 212,000 Nuclear Power Plant Workers; (6) 130,000 Industrial Radiography Workers; (7) 1.7 million Medical Workers and (8) 135,000 Atomic Veterans.

  12. On the effect of bias on the behavior of MOS structures subjected to ionizing radiation

    SciTech Connect (OSTI)

    Aleksandrov, O. V.

    2015-06-15

    Using a quantitative model [6], the analysis of published data on the effect of the gate bias on the behavior of MOS structure subjected to ionizing radiation is performed. It is shown that, along with hydrogen-containing traps, there are hydrogen-free hole traps in samples with a low content of hydrogen; traps of both types are distributed inhomogeneously over the thickness of the gate insulator. In addition to ionized hydrogen, neutral hydrogen is involved in the formation of surface states and provides the main contribution to this process at negative gate bias. A decrease in the shift of the threshold voltage in the case of high fields is caused by an increase in the drift component of the hole drain to the electrodes.

  13. Genetic Background Modulates lncRNA-Coordinated Tissue Response to Low Dose Ionizing Radiation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tang, Jonathan; Huang, Yurong; Nguyen, David H.; Costes, Sylvain V.; Snijders, Antoine M.; Mao, Jian-Hua

    2015-01-01

    Long noncoding RNAs (lncRNAs) are emerging as key regulators of diverse cell functions and processes. However, the relevance of lncRNAs in the cell and tissue response to ionizing radiation has not yet been characterized. Here we used microarray profiling to determine lncRNA and mRNA expression in mammary glands of BALB/c and SPRET/EiJ mice after low-dose ionizing radiation (LDIR) exposure. We found that unirradiated mammary tissues of these strains differed significantly in baseline expressions of 290 lncRNAs. LDIR exposure (10 cGy) induced a significant change in the expression of many lncRNAs. The vast majority of lncRNAs identified to be differentially expressed aftermore » LDIR in either BALB/c or SPRET/EiJ had a significantly correlated expression pattern with at least one LDIR responsive mRNA. Functional analysis revealed that the response to LDIR in BALB/c mice is highly dynamic with enrichment for genes involved in tissue injury, inflammatory responses, and mammary gland development at 2, 4, and 8 weeks after LDIR, respectively. Our study demonstrates that genetic background strongly influences the expression of lncRNAs and their response to radiation and that lncRNAs may coordinate the tissue response to LDIR exposure via regulation of coding mRNAs.« less

  14. Genetic background modulates lncRNA-coordinated tissue response to low dose ionizing radiation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tang, Jonathan; Huang, Yurong; Nguyen, David H.; Costes, Sylvain V.; Snijders, Antoine M.; Mao, Jian -Hua

    2015-02-04

    Long noncoding RNAs (lncRNAs) are emerging as key regulators of diverse cell functions and processes. However, the relevance of lncRNAs in the cell and tissue response to ionizing radiation has not yet been characterized. Here we used microarray profiling to determine lncRNA and mRNA expression in mammary glands of BALB/c and SPRET/EiJ mice after low-dose ionizing radiation (LDIR) exposure. We found that unirradiated mammary tissues of these strains differed significantly in baseline expressions of 290 lncRNAs. LDIR exposure (10 cGy) induced a significant change in the expression of many lncRNAs. The vast majority of lncRNAs identified to be differentially expressedmoreafter LDIR in either BALB/c or SPRET/EiJ had a significantly correlated expression pattern with at least one LDIR responsive mRNA. Functional analysis revealed that the response to LDIR in BALB/c mice is highly dynamic with enrichment for genes involved in tissue injury, inflammatory responses, and mammary gland development at 2, 4, and 8 weeks after LDIR, respectively. Our study demonstrates that genetic background strongly influences the expression of lncRNAs and their response to radiation and that lncRNAs may coordinate the tissue response to LDIR exposure via regulation of coding mRNAs.less

  15. Low-Dose, Ionizing Radiation and Age-Related Changes in Skeletal Microarchitecture

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Alwood, Joshua S.; Kumar, Akhilesh; Tran, Luan H.; Wang, Angela; Limoli, Charles L.; Globus, Ruth K.

    2012-01-01

    Osteoporosis can profoundly affect the aged as a consequence of progressive bone loss; high-dose ionizing radiation can cause similar changes, although less is known about lower doses (≤100 cGy). We hypothesized that exposure to relatively low doses of gamma radiation accelerates structural changes characteristic of skeletal aging. Mice (C57BL/6J-10 wk old, male) were irradiated (total body; 0-sham, 1, 10 or 100 cGy 137 Cs) and tissues harvested on the day of irradiation, 1 or 4 months later. Microcomputed tomography was used to quantify microarchitecture of high turnover, cancellous bone. Irradiation at 100 cGy caused transient microarchitectural changes over one month that were only evidentmore » at longer times in controls (4 months). Ex vivo bone cell differentiation from the marrow was unaffected by gamma radiation. In conclusion, acute ionizing gamma irradiation at 100 cGy (but not at 1 cGy or 10 cGy) exacerbated microarchitectural changes normally found during progressive, postpubertal aging prior to the onset of age-related osteoporosis.« less

  16. Low doses ionizing radiation enhances the invasiveness of breast cancer cells by inducing epithelial-mesenchymal transition

    SciTech Connect (OSTI)

    Zhang, Xin; Li, Xiaoyan; Zhang, Ning; Yang, Qifeng; Moran, Meena S.

    2011-08-19

    Highlights: {yields} Low doses ionizing irradiation would enhance the invasiveness of breast cancer cells by inducing EMT. {yields} Low doses ionizing radiation induced morphologic changes in breast cancer cells. {yields} Low doses ionizing radiation led to upregulation of mesenchymal markers and down-regulation of epithelial markers. {yields} Low doses ionizing radiation increased migration and invasion of breast cancer cells. -- Abstract: Epithelial-mesenchymal transition (EMT) is a process cellular morphologic and molecular alterations facilitate cell invasion. We hypothesized that low dose ionizing irradiation (LDIR) enhances the invasiveness of breast cancer cells by inducing EMT. The effects of LDIR on cellular morphology and the EMT markers of MCF-7 breast cancer cells were analyzed by western blot/RT-PCR and migration/invasion was examined using the transwell assay. We found that LDIR led to the phenotypic changes of EMT in MCF-7 cells and down-regulation of epithelial differentiation markers and transcriptional induction of mesenchymal markers. Furthermore, the radiated cells demonstrated enhanced migration/invasion MCF-7 cells compared with non-radiated cells. In summary, LDIR promotes the invasiveness of breast cancer cells through epithelial to mesenchymal transition. These findings may ultimately provide a new targeted approach for improving the therapeutic effectiveness of radiation in breast cancer.

  17. RADIATION MONITOR CONTAINING TWO CONCENTRIC IONIZATION CHAMBERS AND MEANS FOR INSULATING THE SEPARATE CHAMBERS

    DOE Patents [OSTI]

    Braestrup, C.B.; Mooney, R.T.

    1964-01-21

    This invention relates to a portable radiation monitor containing two concentric ionization chambers which permit the use of standard charging and reading devices. It is particularly adapted as a personnel x-ray dosimeter and to this end comprises a small thin walled, cylindrical conductor forming an inner energy dependent chamber, a small thin walled, cylindrical conductor forming an outer energy independent chamber, and polymeric insulation means which insulates said chambers from each other and holds the chambers together with exposed connections in a simple, trouble-free, and compact assembly substantially without variation in directional response. (AEC)

  18. Modeling of transient ionizing radiation effects in bipolar devices at high dose-rates

    SciTech Connect (OSTI)

    FJELDLY,T.A.; DENG,Y.; SHUR,M.S.; HJALMARSON,HAROLD P.; MUYSHONDT,ARNOLDO

    2000-04-25

    To optimally design circuits for operation at high intensities of ionizing radiation, and to accurately predict their a behavior under radiation, precise device models are needed that include both stationary and dynamic effects of such radiation. Depending on the type and intensity of the ionizing radiation, different degradation mechanisms, such as photoelectric effect, total dose effect, or single even upset might be dominant. In this paper, the authors consider the photoelectric effect associated with the generation of electron-hole pairs in the semiconductor. The effects of low radiation intensity on p-II diodes and bipolar junction transistors (BJTs) were described by low-injection theory in the classical paper by Wirth and Rogers. However, in BJTs compatible with modem integrated circuit technology, high-resistivity regions are often used to enhance device performance, either as a substrate or as an epitaxial layer such as the low-doped n-type collector region of the device. Using low-injection theory, the transient response of epitaxial BJTs was discussed by Florian et al., who mainly concentrated on the effects of the Hi-Lo (high doping - low doping) epilayer/substrate junction of the collector, and on geometrical effects of realistic devices. For devices with highly resistive regions, the assumption of low-level injection is often inappropriate, even at moderate radiation intensities, and a more complete theory for high-injection levels was needed. In the dynamic photocurrent model by Enlow and Alexander. p-n junctions exposed to high-intensity radiation were considered. In their work, the variation of the minority carrier lifetime with excess carrier density, and the effects of the ohmic electric field in the quasi-neutral (q-n) regions were included in a simplified manner. Later, Wunsch and Axness presented a more comprehensive model for the transient radiation response of p-n and p-i-n diode geometries. A stationary model for high-level injection in p

  19. Review of Department of Energy research on human health effects of low doses of ionizing radiation

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    The Department of Energy research program on the human health effects of low-dose ionizing radiation consists of 16 projects conducted under the sponsorship of the Human Health and Assessments Division of the Office of Health and Environmental Research. Each of these projects was reviewed by the Committee with the project's principal investigators and associated scientific personnel and with the DOE staff and the associate directors of the national laboratories where appropriate. The principal objectives of this research program include the determination of the risks from exposure to external radiation and from internally deposited radionuclides and the use of this information in the development of standards to protect the health of nuclear workers at DOE and related facilities and of the population at large. 5 figs., 5 tabs.

  20. Electron density and temperature measurement by continuum radiation emitted from weakly ionized atmospheric pressure plasmas

    SciTech Connect (OSTI)

    Park, Sanghoo; Choe, Wonho, E-mail: wchoe@kaist.ac.kr [Department of Physics, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Youn Moon, Se [High-enthalpy Plasma Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 561-756 (Korea, Republic of); Park, Jaeyoung [5771 La Jolla Corona Drive, La Jolla, CA 92037 (United States)

    2014-02-24

    The electron-atom neutral bremsstrahlung continuum radiation emitted from weakly ionized plasmas is investigated for electron density and temperature diagnostics. The continuum spectrum in 4501000?nm emitted from the argon atmospheric pressure plasma is found to be in excellent agreement with the neutral bremsstrahlung formula with the electron-atom momentum transfer cross-section given by Popovi?. In 280450?nm, however, a large discrepancy between the measured and the neutral bremsstrahlung emissivities is observed. We find that without accounting for the radiative H{sub 2} dissociation continuum, the temperature, and density measurements would be largely wrong, so that it should be taken into account for accurate measurement.

  1. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    DOE Patents [OSTI]

    Majewski, Stanislaw; Kross, Brian J.; Zorn, Carl J.; Majewski, Lukasz A.

    1996-01-01

    An optimized examination system and method based on the Reverse Geometry X-Ray.RTM. (RGX.RTM.) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging.

  2. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    DOE Patents [OSTI]

    Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

    1996-10-22

    An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

  3. Amifostine, a radioprotectant agent, protects rat brain tissue lipids against ionizing radiation induced damage: An FTIR microspectroscopic imaging study

    SciTech Connect (OSTI)

    Cakmak G.; Miller L.; Zorlu, F.; Severcan, F.

    2012-03-03

    Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH{sub 2} groups of lipids decreased significantly and the carbonyl esters, olefinic=CH and CH{sub 3} groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems.

  4. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stark, Karolina; Scott, David E.; Tsyusko, Olga; Coughlin, Daniel P.; Hinton, Thomas G.; Amendola, Roberto

    2015-04-30

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³⁷Cs at 0.13, 2.4, 21, and 222 mGy d⁻¹, resulting in total doses up to 15.8 Gy. Radiation treatments did notmore » affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d⁻¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.« less

  5. Medical imaging using ionizing radiation: Optimization of dose and image quality in fluoroscopy

    SciTech Connect (OSTI)

    Jones, A. Kyle; Balter, Stephen; Rauch, Phillip; Wagner, Louis K.

    2014-01-15

    The 2012 Summer School of the American Association of Physicists in Medicine (AAPM) focused on optimization of the use of ionizing radiation in medical imaging. Day 2 of the Summer School was devoted to fluoroscopy and interventional radiology and featured seven lectures. These lectures have been distilled into a single review paper covering equipment specification and siting, equipment acceptance testing and quality control, fluoroscope configuration, radiation effects, dose estimation and measurement, and principles of flat panel computed tomography. This review focuses on modern fluoroscopic equipment and is comprised in large part of information not found in textbooks on the subject. While this review does discuss technical aspects of modern fluoroscopic equipment, it focuses mainly on the clinical use and support of such equipment, from initial installation through estimation of patient dose and management of radiation effects. This review will be of interest to those learning about fluoroscopy, to those wishing to update their knowledge of modern fluoroscopic equipment, to those wishing to deepen their knowledge of particular topics, such as flat panel computed tomography, and to those who support fluoroscopic equipment in the clinic.

  6. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    SciTech Connect (OSTI)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.

  7. Tritium: a model for low level long-term ionizing radiation exposure

    SciTech Connect (OSTI)

    Carsten, A.L.

    1984-01-01

    The somatic, cytogenetic and genetic effects of single and chronic tritiated water (HTO) ingestion in mice was investigated. This study serves not only as an evaluation of tritium toxicity (TRITOX) but due to its design involving long-term low concentration ingestion of HTO may serve as a model for low level long-term ionizing radiation exposure in general. Long-term studies involved animals maintained on HTO at concentrations of 0.3 ..mu..Ci/ml, 1.0 ..mu..Ci/ml, 3.0 ..mu..Ci/ml or depth dose equivalent chronic external exposures to /sup 137/Cs gamma rays. Maintenance on 3.0 ..mu..Ci/ml resulted in no effect on growth, life-time shortening or bone marrow cellularity, but did result in a reduction of bone marrow stem cells, an increase in DLM's in second generation animals maintained on this regimen and cytogenetic effects as indicated by increased sister chromatid exchanges (SCE's) in bone marrow cells, increased chromosome aberrations in the regenerating liver and an increase in micronuclei in red blood cells. Biochemical and microdosimetry studies showed that animals placed on the HTO regimen reached tritium equilibrium in the body water in approximately 17 to 21 days with a more gradual increase in bound tritium. When animals maintained for 180 days on 3.0 ..mu..Ci/ml HTO were placed on a tap water regimen, the tritium level in tissue dropped from the equilibrium value of 2.02 ..mu..Ci/ml before withdrawal to 0.001 ..mu..Ci/ml at 28 days. 18 references.

  8. IONIZATION CHAMBER

    DOE Patents [OSTI]

    Redman, W.C.; Shonka, F.R.

    1958-02-18

    This patent describes a novel ionization chamber which is well suited to measuring the radioactivity of the various portions of a wire as the wire is moved at a uniform speed, in order to produce the neutron flux traverse pattern of a reactor in which the wire was previously exposed to neutron radiation. The ionization chamber of the present invention is characterized by the construction wherein the wire is passed through a tubular, straight electrode and radiation shielding material is disposed along the wire except at an intermediate, narrow area where the second electrode of the chamber is located.

  9. Low Dose IR Creates an Oncogenic Microenvironment by Inducing Premature

    SciTech Connect (OSTI)

    Yuan, Zhi-Min

    2013-04-28

    Introduction Much of the work addressing ionizing radiation-induced cellular response has been carried out mainly with the traditional cell culture technique involving only one cell type, how cellular response to IR is influenced by the tissue microenvironment remains elusive. By use of a three-dimensional (3D) co-culture system to model critical interactions of different cell types with their neighbors and with their environment, we recently showed that low-dose IR-induced extracellular signaling via the tissue environment affects profoundly cellular responses. This proposal aims at determining the response of mammary epithelial cells in a tissue-like setting.

  10. Measurement of the radiative cooling rates for high-ionization species of krypton using an electron beam ion trap

    SciTech Connect (OSTI)

    Radtke, R.; Biedermann, C.; Fuchs, T.; Fussmann, G.; Beiersdorfer, P.

    2000-02-01

    We describe a measurement of the radiative cooling rate for krypton made at the Berlin electron beam ion trap (EBIT). The EBIT was tuned to a charge-state distribution approaching the ionization balance of a plasma at a temperature of about 5 keV. To determine the cooling rate, we made use of EBIT's capabilities to sample a wide range of electron-beam energies and distinguish between different radiation channels. We have measured the x-ray emission from bremsstrahlung, radiative recombination, dielectronic recombination, and line radiation following electron-impact excitation. The dominant contribution to the cooling rate is made by the n=3-2, n=4-2,... x rays of the L-shell spectra of krypton, which produce more than 75% of the total radiation loss. A difference with theoretical calculations is noted for the measured total cooling rate. The predicted values are lower by a factor of 1.5-2, depending on the theoretical model. For our measurement of the cooling rate, we estimate an uncertainty interval of 22-30 %. (c) 2000 The American Physical Society.

  11. Oxidative Stress and Skeletal Health with Low-Dose, Low-LET (Linear Energy Transfer) Ionizing Radiation

    SciTech Connect (OSTI)

    Globus, Ruth K.

    2014-11-03

    month after irradiation (IR). At four months post-IR, these animals were comparable to sham-treated controls with regards to the abovementioned structural parameters. Irradation at 1 or 10 cGy did not result in any significant changes in bone structural parameters. (3) Irradiation of 16-wk old male mice with high doses of 56Fe or proton (50 or 200cGy), but not at low doses (5 or 10cGy), showed a similar loss of cancellous BV/TV and trabecular number at five weeks post-IR. (4) Age-related bone loss overtook acute radiation-induced decrements in bone structure within four months post-IR with 100 cGy gamma and 12 months post-IR with 200 cGy iron. Transgenic mice globally overexpressing human catalase gene in mitochondria did not exhibit cancellous bone loss as assessed at four month post-IR with 10 cGy proton, 50 cGy iron, or in combination. (5) The cellular and molecular mechanisms responsible for loss of bone with radiation are mediated primarily through increased osteoclastogenesis. Our data provide evidence that there are increases in gene expression of TNF alpha and MCP1 in the bone marrow cells 24 hours post-IR and of osteoclastogenic differentiation factor RANKL by day 3. These cytokines in the marrow may stimulate mature osteoclasts or drive osteoclastogenesis from precursors. (6) Osteoblastogenesis from marrow progenitors evaluated ex vivo decreased following whole body 56Fe irradiation at a dose threshold between 20 and 50 cGy whereas osteoclastogenesis ex vivo increased with doses as low as 10cGy two days post-IR of mice. However, the latter finding was not observed in more than a single experiment. (7) Gamma irradiation of cells in vitro requires relatively high doses (200cGy) to disturb normal osteoblastogenesis and osteoclastogenesis as evidenced by decrements in mineralized nodule formation, osteoclast counts, and expression of osteoblast related genes such as runx2, col1a1. (8) We also investigated the effect of antioxidants on osteoblastogenesis following

  12. The increase in animal mortality risk following exposure to sparsely ionizing radiation is not linear quadratic with dose

    SciTech Connect (OSTI)

    Haley, Benjamin M.; Paunesku, Tatjana; Grdina, David J.; Woloschak, Gayle E.; Aravindan, Natarajan

    2015-12-09

    The US government regulates allowable radiation exposures relying, in large part, on the seventh report from the committee to estimate the Biological Effect of Ionizing Radiation (BEIR VII), which estimated that most contemporary exposures- protracted or low-dose, carry 1.5 fold less risk of carcinogenesis and mortality per Gy than acute exposures of atomic bomb survivors. This correction is known as the dose and dose rate effectiveness factor for the life span study of atomic bomb survivors (DDREFLSS). As a result, it was calculated by applying a linear-quadratic dose response model to data from Japanese atomic bomb survivors and a limited number of animal studies.

  13. The increase in animal mortality risk following exposure to sparsely ionizing radiation is not linear quadratic with dose

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Haley, Benjamin M.; Paunesku, Tatjana; Grdina, David J.; Woloschak, Gayle E.; Aravindan, Natarajan

    2015-12-09

    The US government regulates allowable radiation exposures relying, in large part, on the seventh report from the committee to estimate the Biological Effect of Ionizing Radiation (BEIR VII), which estimated that most contemporary exposures- protracted or low-dose, carry 1.5 fold less risk of carcinogenesis and mortality per Gy than acute exposures of atomic bomb survivors. This correction is known as the dose and dose rate effectiveness factor for the life span study of atomic bomb survivors (DDREFLSS). As a result, it was calculated by applying a linear-quadratic dose response model to data from Japanese atomic bomb survivors and a limitedmore » number of animal studies.« less

  14. Calculation of laser induced impulse based on the laser supported detonation wave model with dissociation, ionization and radiation

    SciTech Connect (OSTI)

    Gan, Li Mousen, Cheng; Xiaokang, Li

    2014-03-15

    In the laser intensity range that the laser supported detonation (LSD) wave can be maintained, dissociation, ionization and radiation take a substantial part of the incidence laser energy. There is little treatment on the phenomenon in the existing models, which brings obvious discrepancies between their predictions and the experiment results. Taking into account the impact of dissociation, ionization and radiation in the conservations of mass, momentum and energy, a modified LSD wave model is developed which fits the experimental data more effectively rather than the existing models. Taking into consideration the pressure decay of the normal and the radial rarefaction, the laser induced impulse that is delivered to the target surface is calculated in the air; and the dependencies of impulse performance on laser intensity, pulse width, ambient pressure and spot size are indicated. The results confirm that the dissociation is the pivotal factor of the appearance of the momentum coupling coefficient extremum. This study focuses on a more thorough understanding of LSD and the interaction between laser and matter.

  15. Dried plum diet protects from bone loss caused by ionizing radiation

    Office of Scientific and Technical Information (OSTI)

    ... 3-phosphate dehydro- genase (Gapdh, assay ID: Mm99999915g1). tte reactions were ... A. Space Radiation Risks for Astronauts on Multiple International Space Station Missions. ...

  16. ON THE DETECTION OF IONIZING RADIATION ARISING FROM STAR-FORMING GALAXIES AT REDSHIFT z {approx} 3-4: LOOKING FOR ANALOGS OF 'STELLAR RE-IONIZERS'

    SciTech Connect (OSTI)

    Vanzella, Eros; Cristiani, Stefano; Nonino, Mario; Guo Yicheng; Giavalisco, Mauro; Grazian, Andrea; Castellano, Marco; Fontana, Adriano; Giallongo, Emanuele; Pentericci, Laura; Galametz, Audrey; Dickinson, Mark; Faber, S. M.; Newman, Jeffrey; Siana, Brian D.

    2012-05-20

    We use the spatially resolved, multi-band photometry in the GOODS South field acquired by the CANDELS project to constrain the nature of candidate Lyman continuum (LyC) emitters at redshift z {approx} 3.7 identified using ultradeep imaging below the Lyman limit (1{sigma} limit of Almost-Equal-To 30 AB in a 2'' diameter aperture). In 19 candidates out of a sample of 20 with flux detected at >3{sigma} level, the light centroid of the candidate LyC emission is offset from that of the Lyman break galaxy (LBG) by up to 1.''5. We fit the spectral energy distribution of the LyC candidates to spectral population synthesis models to measure photometric redshifts and the stellar population parameters. We also discuss the differences in the UV colors between the LBG and the LyC candidates, and how to estimate the escape fraction of ionizing radiation (f{sub esc}) in cases, like in most of our galaxies, where the LyC emission is spatially offset from the host galaxy. In all but one case we conclude that the candidate LyC emission is most likely due to lower redshift interlopers. Based on these findings, we argue that the majority of similar measurements reported in the literature need further investigation before it can be firmly concluded that LyC emission is detected. Our only surviving LyC candidate is an LBG at z = 3.795, which shows the bluest (B - V) color among LBGs at similar redshift, a stellar mass of M {approx} 2 Multiplication-Sign 10{sup 9} M{sub Sun }, weak interstellar absorption lines, and a flat UV spectral slope with no Ly{alpha} in emission. We estimate its f{sub esc} to be in the range 25%-100%, depending on the dust and intergalactic attenuation.

  17. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    SciTech Connect (OSTI)

    Stark, Karolina; Scott, David E.; Tsyusko, Olga; Coughlin, Daniel P.; Hinton, Thomas G.; Amendola, Roberto

    2015-04-30

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³⁷Cs at 0.13, 2.4, 21, and 222 mGy d⁻¹, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d⁻¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.

  18. Precise method of compensating radiation-induced errors in a hot-cathode-ionization gauge with correcting electrode

    SciTech Connect (OSTI)

    Saeki, Hiroshi Magome, Tamotsu

    2014-10-06

    To compensate pressure-measurement errors caused by a synchrotron radiation environment, a precise method using a hot-cathode-ionization-gauge head with correcting electrode, was developed and tested in a simulation experiment with excess electrons in the SPring-8 storage ring. This precise method to improve the measurement accuracy, can correctly reduce the pressure-measurement errors caused by electrons originating from the external environment, and originating from the primary gauge filament influenced by spatial conditions of the installed vacuum-gauge head. As the result of the simulation experiment to confirm the performance reducing the errors caused by the external environment, the pressure-measurement error using this method was approximately less than several percent in the pressure range from 10{sup ?5} Pa to 10{sup ?8} Pa. After the experiment, to confirm the performance reducing the error caused by spatial conditions, an additional experiment was carried out using a sleeve and showed that the improved function was available.

  19. Ionization chamber

    DOE Patents [OSTI]

    Walenta, Albert H.

    1981-01-01

    An ionization chamber has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionize the gas.

  20. Ionization chamber

    DOE Patents [OSTI]

    Walenta, A.H.

    An ionization chamber is described which has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionizes the gas.

  1. Ionizing radiation from hydrogen recombination strongly suppresses the lithium scattering signature in the CMB

    SciTech Connect (OSTI)

    Switzer, Eric R.; Hirata, Christopher M.

    2005-10-15

    It has been suggested that secondary CMB anisotropies generated by neutral lithium could open a new observational window into the universe around the redshift z{approx}400, and permit a determination of the primordial lithium abundance. The effect is due to resonant scattering in the allowed Li i doublet (2s{sup 2}S{sub 1/2}-2p{sup 2}P{sub 1/2,3/2}), so its observability depends on the formation history of neutral lithium. Here we show that the ultraviolet photons produced during hydrogen recombination are sufficient to keep lithium in the Li ii ionization stage in the relevant redshift range and suppress the neutral fraction by {approx}3 orders of magnitude from previous calculations, making the lithium signature unobservable.

  2. Ionizing radiation induced leakage current on ultra-thin gate oxides

    SciTech Connect (OSTI)

    Scarpa, A.; Paccagnella, A.; Montera, F.; Ghibaudo, G.; Pananakakis, G.; Fuochi, P.G.

    1997-12-01

    MOS capacitors with a 4.4 nm thick gate oxide have been exposed to {gamma} radiation from a Co{sup 60} source. As a result, the authors have measured a stable leakage current at fields lower than those required for Fowler-Nordheim tunneling. This Radiation Induced Leakage Current (RILC) is similar to the usual Stress Induced Leakage Currents (SILC) observed after electrical stresses of MOS devices. They have verified that these two currents share the same dependence on the oxide field, and the RILC contribution can be normalized to an equivalent injected charge for Constant Current Stresses. They have also considered the dependence of the RILC from the cumulative radiation dose, and from the applied bias during irradiation, suggesting a correlation between RILC and the distribution of trapped holes and neutral levels in the oxide layer.

  3. Coherent scattering of monochromatic RF radiation by ionization electrons of an extensive air shower

    SciTech Connect (OSTI)

    Filonenko, A. D.

    2013-10-15

    The possibility of detecting extensive air showers by recording and analyzing the radio pulse produced by the reradiation of a wave moving toward the cascade disk is considered. The coherent amplification of the scattered radiation in the direction of motion of the shower is shown to be due to a relativistic effect. An example of a real facility and its peculiarities are discussed.

  4. FIRST INVESTIGATION OF THE COMBINED IMPACT OF IONIZING RADIATION AND MOMENTUM WINDS FROM A MASSIVE STAR ON A SELF-GRAVITATING CORE

    SciTech Connect (OSTI)

    Ngoumou, Judith; Hubber, David; Dale, James E.; Burkert, Andreas

    2015-01-01

    Massive stars shape the surrounding interstellar matter (ISM) by emitting ionizing photons and ejecting material through stellar winds. To study the impact of the momentum from the wind of a massive star on the surrounding neutral or ionized material, we implemented a new HEALPix-based momentum-conserving wind scheme in the smoothed particle hydrodynamics (SPH) code SEREN. A qualitative study of the impact of the feedback from an O7.5-like star on a self-gravitating sphere shows that on its own, the transfer of momentum from a wind onto cold surrounding gas has both a compressing and dispersing effect. It mostly affects gas at low and intermediate densities. When combined with a stellar source's ionizing ultraviolet (UV) radiation, we find the momentum-driven wind to have little direct effect on the gas. We conclude that during a massive star's main sequence, the UV ionizing radiation is the main feedback mechanism shaping and compressing the cold gas. Overall, the wind's effects on the dense gas dynamics and on the triggering of star formation are very modest. The structures formed in the ionization-only simulation and in the combined feedback simulation are remarkably similar. However, in the combined feedback case, different SPH particles end up being compressed. This indicates that the microphysics of gas mixing differ between the two feedback simulations and that the winds can contribute to the localized redistribution and reshuffling of gas.

  5. Exposure to Ionizing Radiation Causes Long-Term Increase in Serum Estradiol and Activation of PI3K-Akt Signaling Pathway in Mouse Mammary Gland

    SciTech Connect (OSTI)

    Suman, Shubhankar; Johnson, Michael D.; Fornace, Albert J.; Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC ; Datta, Kamal

    2012-10-01

    Purpose: Exposure to ionizing radiation is an established risk factor for breast cancer. Radiation exposure during infancy, childhood, and adolescence confers the highest risk. Although radiation is a proven mammary carcinogen, it remains unclear where it acts in the complex multistage process of breast cancer development. In this study, we investigated the long-term pathophysiologic effects of ionizing radiation at a dose (2 Gy) relevant to fractionated radiotherapy. Methods and Materials: Adolescent (6-8 weeks old; n = 10) female C57BL/6J mice were exposed to 2 Gy total body {gamma}-radiation, the mammary glands were surgically removed, and serum and urine samples were collected 2 and 12 months after exposure. Molecular pathways involving estrogen receptor-{alpha} (ER{alpha}) and phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling were investigated by immunohistochemistry and Western blot. Results: Serum estrogen and urinary levels of the oncogenic estrogen metabolite (16{alpha}OHE1) were significantly increased in irradiated animals. Immunostaining for the cellular proliferative marker Ki-67 and cyclin-D1 showed increased nuclear accumulation in sections of mammary glands from irradiated vs. control mice. Marked increase in p85{alpha}, a regulatory sub-unit of the PI3K was associated with increase in Akt, phospho-Akt, phospho-BAD, phospho-mTOR, and c-Myc in irradiated samples. Persistent increase in nuclear ER{alpha} in mammary tissues 2 and 12 months after radiation exposure was also observed. Conclusions: Taken together, our data not only support epidemiologic observations associating radiation and breast cancer but also, specify molecular events that could be involved in radiation-induced breast cancer.

  6. Ionizing Radiation Detector

    DOE Patents [OSTI]

    Wright, Gomez W.; James, Ralph B.; Burger, Arnold; Chinn, Douglas A.

    2003-11-18

    A CdZnTe (CZT) crystal provided with a native CdO dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals is disclosed. A two step process is provided for forming the dielectric coating which includes etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and passivating the CZT crystal surface with a solution of 10 w/o NH.sub.4 F and 10 w/o H.sub.2 O.sub.2 in water after attaching electrical contacts to the crystal surface.

  7. The inhibitory effect of ionizing radiation on Fc and C3 receptors on mouse and human leukocytes, and the protective potential of human albumin

    SciTech Connect (OSTI)

    Herrera, M.A.; Diaz-Perches, R.; Gutierrez, M.; Gamminio, E.; Liera, C.; Nieto, P.; Weiss-Steider, B. )

    1990-08-01

    The effect that ionizing radiation has in vitro on Fc and C3 receptors was evaluated at various doses and measured by means of erythrocytes coated with antibody (EA) and erythrocytes coated with antibody and complement (EAC) rosettes on human peripheral blood leukocytes (PBL) and on mouse bone marrow cells (BMC) and PBL. We found that the number of cells with either EA and EAC rosettes decreased as the radiation doses increased, and that they were almost absent when the highest doses were employed. We obtained evidence that albumin is a natural source of radio-protection for Fc and C3 receptors, and we showed that by increasing the amount of this molecule we could completely protect receptors for EA and EAC in vitro. Finally, the possible therapeutic value of the administration of human albumin to patients undergoing radiotherapy is discussed.

  8. The effect of low dose ionizing radiation on homeostasis and functional integrity in an organotypic human skin model

    SciTech Connect (OSTI)

    von Neubeck, Claere; Geniza, Matthew; Kauer, Paula M.; Robinson, Joseph E.; Chrisler, William B.; Sowa, Marianne B.

    2015-05-01

    Outside the protection of earth’s atmosphere, astronauts are exposed to low doses of high linear energy transfer (LET) radiation. Future NASA plans for deep space missions or a permanent settlement on the moon are limited by the health risks associated with space radiation exposures. There is a paucity of direct epidemiological data for low dose exposures to space radiation-relevant high LET ions. Health risk models are used to estimate the risk for such exposures, though these models are based on high dose experiments. There is increasing evidence, however, that low and high dose exposures result in different signaling events at the molecular level, and may involve different response mechanisms. Further, despite their low abundance, high LET particles have been identified as the major contributor to health risk during manned space flight. The human skin is exposed in every external radiation scenario, making it an ideal epithelial tissue model in which to study radiation induced effects. Here, we exposed an in vitro three dimensional (3-D) human organotypic skin tissue model to low doses of high LET oxygen (O), silicon (Si) and iron (Fe) ions. We measured proliferation and differentiation profiles in the skin tissue and examined the integrity of the skin’s barrier function. We discuss the role of secondary particles in changing the proportion of cells receiving a radiation dose, emphasizing the possible impact on radiation-induced health issues in astronauts.

  9. The effects of ionizing radiation on Reillex trademark HPQ, a new macroporous polyvinylpyridine resin, and on four conventional polystyrene anion exchange resins

    SciTech Connect (OSTI)

    Marsh, S.F.

    1990-11-01

    This study compares the effects of ionizing radiation on Reillex{trademark} HPQ, a recently available macroporous copolymer of 1-methyl-4-vinylpyridine/divinylbenzene, and on four conventional strong-base polystyrene anion exchange resins. The polystyrene resins investigated included one gel type, Dowex{trademark} 1 {times} 4, and three macroporous resins: Dow{trademark} MSA-1, Amberlite{trademark} IRA-900, and Lewatit{trademark} MP-500-FK. Each resin, in 7 M nitric acid, was subjected to seven different levels of {sup 60}Co gamma radiation ranging from 100 to 1000 megarads. Irradiated resins were measured for changes in dry weight, wet volume, chloride and Pu(IV) exchange capacities, and thermal stability. In separate experiments, each resin was subjected to approximately 340 megarads of in situ alpha particles from sorbed plutonium. Resin damage from alpha particles was less than half that caused by gamma rays, which may be a consequence of different production rates of radiolytic nitrite and nitro radicals in the two systems. Reillex{trademark} HPQ resin provided the greatest radiation stability, whereas Lewatit{trademark} MP-500-FK was the least stable of the resins tested. Thermogravimetric analyses of dry, nitrate-form resin revealed that dry Reillex{trademark} HPQ resin offered the best thermal stability for absorbed gamma doses to 370 megarads, but the worst thermal stability after exposures of 550 megarads or more. 25 refs., 11 figs., 13 tabs.

  10. Ionization detection system for aerosols

    DOE Patents [OSTI]

    Jacobs, Martin E.

    1977-01-01

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system utilizes a measuring ionization chamber which is modified to minimize false alarms and reductions in sensitivity resulting from changes in ambient temperature. In the preferred form of the modification, an annular radiation shield is mounted about the usual radiation source provided to effect ionization in the measuring chamber. The shield is supported by a bimetallic strip which flexes in response to changes in ambient temperature, moving the shield relative to the source so as to vary the radiative area of the source in a manner offsetting temperature-induced variations in the sensitivity of the chamber.

  11. Combination Effect of Regulatory T-Cell Depletion and Ionizing Radiation in Mouse Models of Lung and Colon Cancer

    SciTech Connect (OSTI)

    Son, Cheol-Hun; Bae, Jae-Ho; Shin, Dong-Yeok; Lee, Hong-Rae; Jo, Wol-Soon; Yang, Kwangmo; Park, You-Soo

    2015-06-01

    Purpose: To investigate the potential of low-dose cyclophosphamide (LD-CTX) and anti-CD25 antibody to prevent activation of regulatory T cells (Tregs) during radiation therapy. Methods and Materials: We used LD-CTX and anti-CD25 monoclonal antibody as a means to inhibit Tregs and improve the therapeutic effect of radiation in a mouse model of lung and colon cancer. Mice were irradiated on the tumor mass of the right leg and treated with LD-CTX and anti-CD25 antibody once per week for 3 weeks. Results: Combined treatment of LD-CTX or anti-CD25 antibody with radiation significantly decreased Tregs in the spleen and tumor compared with control and irradiation only in both lung and colon cancer. Combinatorial treatments resulted in a significant increase in the effector T cells, longer survival rate, and suppressed irradiated and distal nonirradiated tumor growth. Specifically, the combinatorial treatment of LD-CTX with radiation resulted in outstanding regression of local and distant tumors in colon cancer, and almost all mice in this group survived until the end of the study. Conclusions: Our results suggest that Treg depletion strategies may enhance radiation-mediated antitumor immunity and further improve outcomes after radiation therapy.

  12. On the possibility of the generation of high harmonics with photon energies greater than 10 keV upon interaction of intense mid-IR radiation with neutral gases

    SciTech Connect (OSTI)

    Emelina, A S; Emelin, M Yu; Ryabikin, M Yu

    2014-05-30

    Based on the analytical quantum-mechanical description in the framework of the modified strong-field approximation, we have investigated high harmonic generation of mid-IR laser radiation in neutral gases taking into account the depletion of bound atomic levels of the working medium and the electron magnetic drift in a high-intensity laser field. The possibility is shown to generate high-order harmonics with photon energies greater than 10 keV under irradiation of helium atoms by intense femtosecond laser pulses with a centre wavelength of 8 – 10.6 μm. (interaction of radiation with matter)

  13. Characterization of radiation beams used to determinate the correction factor for a CyberKnife unit reference field using ionization chambers

    SciTech Connect (OSTI)

    Aragn-Martnez, Nestor Massillon-JL, Guerda; Gmez-Muoz, Arnulfo

    2014-11-07

    This paper aimed to characterize a 6 MV x-ray beam from a Varian iX linear accelerator in order to obtain the correction factors needed by the IAEA/AAPM new formalism{sup 1}. The experiments were performed in a liquid water phantom under different irradiation conditions: a) Calibration of the reference field of 10 cm 10 cm at 90 cm SSD and 10 cm depth was carried out according to the TRS-398 protocol using three ionization chambers (IC) calibrated in different reference laboratory and b) Measurement of the absorbed dose rate at 70 cm SSD and 10 cm depth in a 10 cm 10 cm and 5.4 cm 5.4 cm fields was obtained in order to simulate the CyberKnife conditions where maximum distance between the source and the detector is equal to 80 cm and the maximum field size is 6 cm diameter. Depending where the IC was calibrated, differences between 0.16% and 2.24% in the absorbed dose rate measured in the 10 cm 10 cm field at 90 cm SSD were observed, while for the measurements at 70 cm SSD, differences between 1.27% and 3.88% were obtained. For the 5.4 cm 5.4 cm field, the absorbed dose measured with the three ICs varies between 1.37% and 3.52%. The increase in the difference on the absorbed dose when decreasing the SSD could possibly be associated to scattering radiation generated from the collimators and/or the energy dependence of the ionization chambers to low-energy radiation. The results presented in this work suggest the importance of simulating the CyberKnife conditions using other linear accelerator for obtaining the correction factors as proposed by the IAEA/AAPM new formalism in order to measure the absorbed dose with acceptable accuracy.

  14. Amorphous silicon ionizing particle detectors

    DOE Patents [OSTI]

    Street, R.A.; Mendez, V.P.; Kaplan, S.N.

    1988-11-15

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation. 15 figs.

  15. Amorphous silicon ionizing particle detectors

    DOE Patents [OSTI]

    Street, Robert A.; Mendez, Victor P.; Kaplan, Selig N.

    1988-01-01

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation.

  16. Welding arc gap ionization device

    DOE Patents [OSTI]

    Schweikhardt, George M.

    1976-01-01

    An alpha emitting isotope is positioned near the tip of a TIG welding electrode so that the alpha radiation can provide an ionized path between the electrode and the workpiece.

  17. Activation of eNOS in endothelial cells exposed to ionizing radiation involves components of the DNA damage response pathway

    SciTech Connect (OSTI)

    Nagane, Masaki; Yasui, Hironobu; Sakai, Yuri; Yamamori, Tohru; Niwa, Koichi; Hattori, Yuichi; Kondo, Takashi; Inanami, Osamu

    2015-01-02

    Highlights: eNOS activity is increased in BAECs exposed to X-rays. ATM is involved in this increased eNOS activity. HSP90 modulates the radiation-induced activation of ATM and eNOS. - Abstract: In this study, the involvement of ataxia telangiectasia mutated (ATM) kinase and heat shock protein 90 (HSP90) in endothelial nitric oxide synthase (eNOS) activation was investigated in X-irradiated bovine aortic endothelial cells. The activity of nitric oxide synthase (NOS) and the phosphorylation of serine 1179 of eNOS (eNOS-Ser1179) were significantly increased in irradiated cells. The radiation-induced increases in NOS activity and eNOS-Ser1179 phosphorylation levels were significantly reduced by treatment with either an ATM inhibitor (Ku-60019) or an HSP90 inhibitor (geldanamycin). Geldanamycin was furthermore found to suppress the radiation-induced phosphorylation of ATM-Ser1181. Our results indicate that the radiation-induced eNOS activation in bovine aortic endothelial cells is regulated by ATM and HSP90.

  18. Radiation Protection and Safety Training | Environmental Radiation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiation Protection and Safety Training (3 hrs) Instructors: John Seaman and Neil Miller ... with an introduction to the fundamentals of ionizing radiation protection and safety. ...

  19. The carboxyl-terminal of BRCA1 is required for subnuclear assembly of RAD51 after treatment with cisplatin but not ionizing radiation in human breast and ovarian cancer cells

    SciTech Connect (OSTI)

    Zhou Chenyi; Huang Peng; Liu Jinsong . E-mail: jliu@mdanderson.org

    2005-10-28

    BRCA1 plays an important role in maintaining genomic stability through its involvement in DNA repair. Although it is known that BRCA1 and RAD51 form distinct DNA repair subnuclear complexes, or foci, following environmental insults to the DNA, the role of BRCA1 in this process remains to be characterized. The purpose of the study was therefore to determine the role of BRCA1 in the formation of RAD51 foci following treatment with cisplatin and ionizing radiation. We found that although a functional BRCA1 is required for the subnuclear assembly of BRCA1 foci following treatment with either ionizing radiation or cisplatin, a functional BRCA1 is required for RAD51 foci to form following treatment with cisplatin but not with ionizing radiation. Similar results were obtained in SKOV-3 cells when the level of BRCA1 expression was knocked down by stable expression of a retrovirus-mediated small-interfering RNA against BRCA1. We also found that the carboxyl-terminal of BRCA1 contains uncharacterized phosphorylation sites that are responsive to cisplatin. The functional BRCA1 is also required for breast and ovarian cancer cells to mount resistance to cisplatin. These results suggest that the carboxyl-terminal of BRCA1 is required for the cisplatin-induced recruitment of RAD51 to the DNA-damage site, which may contribute to cisplatin resistance.

  20. Hf-irJ

    Office of Legacy Management (LM)

    Hf-irJ jnj,4 States Governmen Department of Energy Inemorandum DOTE: DAY o 1S5a . 7 EPY TO F . O 0 NE-24 SUJEC': Authorization for Remedial Action of Residential Vicinity ...

  1. Hand and shoe monitor using air ionization probes

    DOE Patents [OSTI]

    Fergus, Richard W.

    1981-01-01

    A hand and shoe radiation monitor is provided which includes a probe support body defining a plurality of cells, within each cell there being an ionization probe. The support body provides structural strength for protecting the ionization probes from force applied to the support body during a radiation monitoring event. There is also provided a fast response time amplifier circuit for the output from the ionization probes.

  2. Incorporating Radiation Effects into Edge Plasma Transport Models...

    Office of Scientific and Technical Information (OSTI)

    radiation can significantly affect the ionization and energy balance in these plasmas. ... Subject: 70 PLASMA PHYSICS AND FUSION; DIMENSIONS; ENERGY BALANCE; HYDROGEN; IONIZATION; ...

  3. 10 CFR 835- Occupational Radiation Protection

    Office of Energy Efficiency and Renewable Energy (EERE)

    The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities.

  4. Total ionizing dose effect of γ-ray radiation on the switching characteristics and filament stability of HfOx resistive random access memory

    SciTech Connect (OSTI)

    Fang, Runchen; Yu, Shimeng; Gonzalez Velo, Yago; Chen, Wenhao; Holbert, Keith E.; Kozicki, Michael N.; Barnaby, Hugh

    2014-05-05

    The total ionizing dose (TID) effect of gamma-ray (γ-ray) irradiation on HfOx based resistive random access memory was investigated by electrical and material characterizations. The memory states can sustain TID level ∼5.2 Mrad (HfO{sub 2}) without significant change in the functionality or the switching characteristics under pulse cycling. However, the stability of the filament is weakened after irradiation as memory states are more vulnerable to flipping under the electrical stress. X-ray photoelectron spectroscopy was performed to ascertain the physical mechanism of the stability degradation, which is attributed to the Hf-O bond breaking by the high-energy γ-ray exposure.

  5. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2007-01-09

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  6. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2010-06-15

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

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

    DOE Patents [OSTI]

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

    2011-04-26

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

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

    DOE Patents [OSTI]

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

    2011-05-03

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

  9. I\r'

    Office of Legacy Management (LM)

    r' ( g-.] ic' fz .; w .fl ! : L ' ..j : i ?- z -2"" . 2,-3X-~ Aw23-t 11, 1949 J c. s. ?.%omic ?zaru ccm3ission 7-t i-~n,~-;ra-& 3&-p.Cz' ;"ica P. ' 3. 30x 3 Eacsrs 17, lIaw York :. , ::; /. 1 httetii OP J xl-. P, 3. 2gp C+~t~Sil;lsXl t ?~~$Tly~lf .t: GA.3 L?wjpnaJiQn Of p-3&7:2-Liop 9.0";:7~+50 s' , -ir ,.,,3 iashlla+im it i3 our da3irs 20 be rslia-T.73 of _"\L:t&?T --:wzk&ili* of the SC1298 ' _ _ Zj31Wf end i~i3sio~~31.3 rsskeri31ii izxLi.c~~t&

  10. Risk of Low Dose/Low Dose Rate Ionizing Radiation to Humans Symposium at the EMS 2009 Annual Meeting - September 2006

    SciTech Connect (OSTI)

    Morgan, William F.; von Borstel, Robert C.; Brenner, David; Redpath, J. Leslie; Erickson, Barbra E.; Brooks, Antone L.

    2009-11-12

    The low dose symposium thoughtfully addressed controversy of risk from low dose radiation exposure, hormesis and radon therapy. The stem cell symposium cogently considered the role of DNA damage and repair in hematopoietic stem cells underlying aging and malignancy and provocatively presented evidence that stem cells may have distinct morphologies and replicative properties, as well as special roles in cancer initiation. In the epigenetics symposium, studies illustrated the long range interaction of epigenetic mechanisms, the roles of CTCF and BORIS in region/specific regulation of epigenetic processes, the impact of DNA damage on epigenetic processes as well as links between epigenetic mechanisms and early nutrition and bystander effects.

  11. Poly [1,1'-bis(ethynyl)-4,4'-biphenyl(bis-tributylphosphine)Pt(II)] solutions used as low dose ionizing radiation dosimeter

    SciTech Connect (OSTI)

    Bronze-Uhle, E. S.; Graeff, C. F. O.; Batagin-Neto, A.; Fernandes, D. M.; Fratoddi, I.; Russo, M. V.

    2013-06-17

    In this work, the effect of gamma radiation on the optical properties of polymetallayne poly[1,1'-bis(ethynyl)-4,4'-biphenyl(bis-tributylphosphine)Pt(II)] (Pt-DEBP) in chloroform solution is studied. The samples were irradiated at room temperature with doses from 0.01 Gy to 1 Gy using a {sup 60}Co gamma ray source. A new band at 420 nm is observed in the emission spectra, in superposition to the emission maximum at 398 nm, linearly dependent on dose. We propose to use the ratio of the emission amplitude bands as the dosimetric parameter. This method proved to be robust, accurate, and can be used as a dosimeter in medical applications.

  12. IR Spot Weld Inspect

    Energy Science and Technology Software Center (OSTI)

    2014-01-01

    In automotive industry, destructive inspection of spot welds is still the mandatory quality assurance method due to the lack of efficient non-destructive evaluation (NDE) tools. However, it is costly and time-consuming. Recently at ORNL, a new NDE prototype system for spot weld inspection using infrared (IR) thermography has been developed to address this problem. This software contains all the key functions that ensure the NDE system to work properly: system input/output control, image acquisition, datamore » analysis, weld quality database generation and weld quality prediction, etc.« less

  13. Analytical instruments, ionization sources, and ionization methods

    DOE Patents [OSTI]

    Atkinson, David A.; Mottishaw, Paul

    2006-04-11

    Methods and apparatus for simultaneous vaporization and ionization of a sample in a spectrometer prior to introducing the sample into the drift tube of the analyzer are disclosed. The apparatus includes a vaporization/ionization source having an electrically conductive conduit configured to receive sample particulate which is conveyed to a discharge end of the conduit. Positioned proximate to the discharge end of the conduit is an electrically conductive reference device. The conduit and the reference device act as electrodes and have an electrical potential maintained between them sufficient to cause a corona effect, which will cause at least partial simultaneous ionization and vaporization of the sample particulate. The electrical potential can be maintained to establish a continuous corona, or can be held slightly below the breakdown potential such that arrival of particulate at the point of proximity of the electrodes disrupts the potential, causing arcing and the corona effect. The electrical potential can also be varied to cause periodic arcing between the electrodes such that particulate passing through the arc is simultaneously vaporized and ionized. The invention further includes a spectrometer containing the source. The invention is particularly useful for ion mobility spectrometers and atmospheric pressure ionization mass spectrometers.

  14. Biologically based multistage modeling of radiation effects

    SciTech Connect (OSTI)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of epidemiologic studies using multistage

  15. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1995-10-17

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  16. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1994-08-16

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  17. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H.

    1995-01-01

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  18. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H.

    1994-01-01

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  19. Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION...

    Broader source: Energy.gov (indexed) [DOE]

    rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE ...

  20. ORISE: Advanced Radiation Medicine | REAC/TS Continuing Medical...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Advanced Radiation Medicine Dates Scheduled Register Online August 15-19, 2016 Fee: 275 ... information on the diagnosis and management of ionizing radiation injuries and illnesses. ...

  1. Laser stripping of hydrogen atoms by direct ionization

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Brunetti, E.; Becker, W.; Bryant, H. C.; Jaroszynski, D. A.; Chou, W.

    2015-05-08

    Direct ionization of hydrogen atoms by laser irradiation is investigated as a potential new scheme to generate proton beams without stripping foils. The time-dependent Schrödinger equation describing the atom-radiation interaction is numerically solved obtaining accurate ionization cross-sections for a broad range of laser wavelengths, durations and energies. Parameters are identified where the Doppler frequency up-shift of radiation colliding with relativistic particles can lead to efficient ionization over large volumes and broad bandwidths using currently available lasers.

  2. ARM - Datastreams - goes7ir

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ir Documentation XDC documentation Data Quality Plots ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Datastream : GOES7IR GOES-7: infrared, channels 7, 10, 12

  3. AS-2, a novel inhibitor of p53-dependent apoptosis, prevents apoptotic mitochondrial dysfunction in a transcription-independent manner and protects mice from a lethal dose of ionizing radiation

    SciTech Connect (OSTI)

    Morita, Akinori; Ariyasu, Shinya; Wang, Bing; Asanuma, Tetsuo; Onoda, Takayoshi; Sawa, Akiko; Tanaka, Kaoru; Takahashi, Ippei; Togami, Shotaro; Nenoi, Mitsuru; Inaba, Toshiya; Aoki, Shin

    2014-08-08

    mice that had been exposed to a lethal dose of ionizing radiation. Our findings indicate that some types of bidentate 8HQ chelators could serve as radioprotectors with no substantial toxicity in vivo.

  4. Attosecond control of dissociative ionization of O{sub 2} molecules

    SciTech Connect (OSTI)

    Siu, W.; Kelkensberg, F.; Gademann, G.; Rouzee, A.; Vrakking, M. J. J.; Johnsson, P.; Dowek, D.; Lucchini, M.; Calegari, F.; De Giovannini, U.; Rubio, A.; Lucchese, R. R.; Kono, H.; Lepine, F.

    2011-12-15

    We demonstrate that dissociative ionization of O{sub 2} can be controlled by the relative delay between an attosecond pulse train (APT) and a copropagating infrared (IR) field. Our experiments reveal a dependence of both the branching ratios between a range of electronic states and the fragment angular distributions on the extreme ultraviolet (XUV) to IR time delay. The observations go beyond adiabatic propagation of dissociative wave packets on IR-induced quasistatic potential energy curves and are understood in terms of an IR-induced coupling between electronic states in the molecular ion.

  5. Radiation detector

    DOE Patents [OSTI]

    Fultz, B.T.

    1980-12-05

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

  6. Radiation detector

    DOE Patents [OSTI]

    Fultz, Brent T.

    1983-01-01

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

  7. Ionization Branching Ratio Control with a Resonance Attosecond Clock

    SciTech Connect (OSTI)

    Argenti, Luca; Lindroth, Eva

    2010-07-30

    We investigate the possibility to monitor the dynamics of autoionizing states in real-time and control the yields of different ionization channels in helium by simulating extreme ultraviolet (XUV) pump IR-probe experiments focused on the N=2 threshold. The XUV pulse creates a coherent superposition of doubly excited states which is found to decay by ejecting electrons in bursts. Prominent interference fringes in the photoelectron angular distribution of the 2s and 2p ionization channels are observed, along with significant out-of-phase quantum beats in the yields of the corresponding parent ions.

  8. Alkali metal ionization detector

    DOE Patents [OSTI]

    Bauerle, James E.; Reed, William H.; Berkey, Edgar

    1978-01-01

    Variations in the conventional filament and collector electrodes of an alkali metal ionization detector, including the substitution of helical electrode configurations for either the conventional wire filament or flat plate collector; or, the substitution of a plurality of discrete filament electrodes providing an in situ capability for transferring from an operationally defective filament electrode to a previously unused filament electrode without removing the alkali metal ionization detector from the monitored environment. In particular, the helical collector arrangement which is coaxially disposed about the filament electrode, i.e. the thermal ionizer, provides an improved collection of positive ions developed by the filament electrode. The helical filament design, on the other hand, provides the advantage of an increased surface area for ionization of alkali metal-bearing species in a monitored gas environment as well as providing a relatively strong electric field for collecting the ions at the collector electrode about which the helical filament electrode is coaxially positioned. Alternatively, both the filament and collector electrodes can be helical. Furthermore, the operation of the conventional alkali metal ionization detector as a leak detector can be simplified as to cost and complexity, by operating the detector at a reduced collector potential while maintaining the sensitivity of the alkali metal ionization detector adequate for the relatively low concentration of alkali vapor and aerosol typically encountered in leak detection applications.

  9. IR-2003- | Department of Energy

    Energy Savers [EERE]

    IR-2003- (20.04 KB) More Documents & Publications Fact Sheet: Clean Coal Technology Ushers In New Era in Energy Fact Sheet: Clean Coal Technology Ushers In New Era in Energy ...

  10. Detailed and simplified nonequilibrium helium ionization in the solar atmosphere

    SciTech Connect (OSTI)

    Golding, Thomas Peter; Carlsson, Mats; Leenaarts, Jorrit E-mail: mats.carlsson@astro.uio.no

    2014-03-20

    Helium ionization plays an important role in the energy balance of the upper chromosphere and transition region. Helium spectral lines are also often used as diagnostics of these regions. We carry out one-dimensional radiation-hydrodynamics simulations of the solar atmosphere and find that the helium ionization is set mostly by photoionization and direct collisional ionization, counteracted by radiative recombination cascades. By introducing an additional recombination rate mimicking the recombination cascades, we construct a simplified three-level helium model atom consisting of only the ground states. This model atom is suitable for modeling nonequilibrium helium ionization in three-dimensional numerical models. We perform a brief investigation of the formation of the He I 10830 and He II 304 spectral lines. Both lines show nonequilibrium features that are not recovered with statistical equilibrium models, and caution should therefore be exercised when such models are used as a basis for interpretating observations.

  11. Characterization of the role of Fhit in maintenance of genomic integrity following low dose radiation, in vivo and in vitro

    SciTech Connect (OSTI)

    Ya Wang

    2010-05-31

    The major goal of this study is to determine the effects of the Fhit pathway on low dose ({le} 0.1 Gy) ionizing radiation (IR)-induced genetic instability. Reduction of Fhit protein expression is observed in most solid tumors particularly in those tumors resulting from exposure to environmental carcinogens. Therefore, characterization of the role of the Fhit-dependent pathway in preventing low dose IR-induced genetic instability will provide useful parameters for evaluating the low dose IR-induced risk of mutagenesis and carcinogenesis. We pursued 3 specific aims to study our hypothesis that the Fhit-dependent pathways maintain genomic integrity through adjusting checkpoint response and repair genes expression following low dose IR. Aim 1: Determine whether Fhit interaction with RPA is necessary for Fhit to affect the cellular response to low dose IR. We combined the approaches of in vitro (GST pull-down and site-directed mutagenesis) and in vivo (observing the co-localization and immunoprecipitation of Fhit and RPA in Fhit knock out mouse cells transfected with mutant Fhit which has lost ability to interact with RPA in vitro). Aim 2: Determine the role of genes whose expression is affected by Fhit in low dose irradiated cells. We analyzed the distinct signature of gene expression in low dose irradiated Fhit-/- cells compared with Fhit+/+ cells by combining microarray, gene transfection and siRNA approaches. Aim 3: Determine the role of Fhit in genetic susceptibility to low dose IR in vivo. We compared the gene mutation frequency and the fragile site stability in the cells isolated from the Fhit+/+ and Fhit-/- mice at 1.5 years following low dose IR. These results determine the role of the Fhit-dependent pathway in maintaining genomic integrity in vitro and in vivo, which provide a basis for choosing surrogate markers in the Fhit-dependent pathway to evaluate low dose IR-induced risk of mutagenesis and carcinogenesis.

  12. Characterization of the role of Fhit in maintenance of genomic integrity following low dose radiation, in vivo and in vitro

    SciTech Connect (OSTI)

    Wang, Ya

    2010-05-14

    The major goal of this study is to determine the effects of the Fhit pathway on low dose (< 0.1 Gy) ionizing radiation (IR)-induced genetic instability. Reduction of Fhit protein expression is observed in most solid tumors particularly in those tumors resulting from exposure to environmental carcinogens. Therefore, characterization of the role of the Fhit-dependent pathway in preventing low dose IR-induced genetic instability will provide useful parameters for evaluating the low dose IR-induced risk of mutagenesis and carcinogenesis. We pursued 3 specific aims to study our hypothesis that the Fhit-dependent pathways maintain genomic integrity through adjusting checkpoint response and repair genes expression following low dose IR. Aim 1: Determine whether Fhit interaction with RPA is necessary for Fhit to affect the cellular response to low dose IR. We combined the approaches of in vitro (GST pull-down and site-directed mutagenesis) and in vivo (observing the co-localization and immunoprecipitation of Fhit and RPA in Fhit knock out mouse cells transfected with mutant Fhit which has lost ability to interact with RPA in vitro). Aim 2: Determine the role of genes whose expression is affected by Fhit in low dose irradiated cells. We analyzed the distinct signature of gene expression in low dose irradiated Fhit-/- cells compared with Fhit+/+ cells by combining microarray, gene transfection and siRNA approaches. Aim 3: Determine the role of Fhit in genetic susceptibility to low dose IR in vivo. We compared the gene mutation frequency and the fragile site stability in the cells isolated from the Fhit+/+ and Fhit-/- mice at 1.5 years following low dose IR. These results determine the role of the Fhit-dependent pathway in maintaining genomic integrity in vitro and in vivo, which provide a basis for choosing surrogate markers in the Fhit-dependent pathway to evaluate low dose IR-induced risk of mutagenesis and carcinogenesis.

  13. (Resonance ionization spectroscopy)

    SciTech Connect (OSTI)

    Young, J.P.

    1990-10-11

    J. P. Young attended the Fifth International Symposium on Resonance Ionization Spectroscopy and presented an invited oral presentation on research he and coworkers had carried out in applying diode lasers to resonance ionization mass spectrometry. A summary of the conference is given along with an assessment of some of the presentations that the author found of interest. Young also visited Professor Marassi at the University of Camerino to present a seminar and discuss mutual interests in a new molten salt research project of the author. Some of the studies at Camerino are described. Ideas concerning the author's research that came from private discussions are also presented here.

  14. Alkali ionization detector

    DOE Patents [OSTI]

    Hrizo, John (Monroeville, PA); Bauerle, James E. (Plum Borough, PA); Witkowski, Robert E. (West Mifflin, PA)

    1982-01-01

    A calibration filament containing a sodium-bearing compound is included in combination with the sensing filament and ion collector plate of a sodium ionization detector to permit periodic generation of sodium atoms for the in-situ calibration of the detector.

  15. Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir

    SciTech Connect (OSTI)

    Morris, James R; Averill, Frank; Cooper, Valentino R

    2014-01-01

    Experimentally, it is known that very small amounts of thorium and/or cerium added to iridium metal form a precipitate, Ir5Th / Ir5Ce, which improves the high temperature mechanical properties of the resulting alloys. We demonstrate that there are low-energy configurations for nano-scale precipitates of these phases in Ir, and that these coherent arrangements may assist in producing improved mechanical properties. One precipitate/matrix orientation gives a particularly low interfacial energy, and a low lattice misfit. Nanolayer precipitates with this orientation are found to be likely to form, with little driving force to coarsen. The predicted morphology of the precipitates and their orientation with the matrix phase provide a potential experiment that could be used to test these predictions.

  16. Electrospray Ionization Mass Spectrometry

    SciTech Connect (OSTI)

    Kelly, Ryan T.; Marginean, Ioan; Tang, Keqi

    2014-06-13

    Electrospray Ionization (ESI) is a process whereby gas phase ions are created from molecules in solution. As a solution exits a narrow tube in the presence of a strong electric field, an aerosol of charged droplets are is formed that produces gas phase ions as they it desolvates. ESI-MS comprises the creation of ions by ESI and the determination of their mass to charge ratio (m/z) by MS.

  17. Ionizing Radiation–Inducible miR-27b Suppresses Leukemia Proliferation via Targeting Cyclin A2

    SciTech Connect (OSTI)

    Wang, Bo; Li, Dongping; Kovalchuk, Anna; Litvinov, Dmitry; Kovalchuk, Olga

    2014-09-01

    Purpose: Ionizing radiation is a common carcinogen that is important for the development of leukemia. However, the underlying epigenetic mechanisms remain largely unknown. The goal of the study was to explore microRNAome alterations induced by ionizing radiation (IR) in murine thymus, and to determine the role of IR-inducible microRNA (miRNA/miR) in the development of leukemia. Methods and Materials: We used the well-established C57BL/6 mouse model and miRNA microarray profiling to identify miRNAs that are differentially expressed in murine thymus in response to irradiation. TIB152 human leukemia cell line was used to determine the role of estrogen receptor–α (ERα) in miR-27b transcription. The biological effects of ectopic miR-27b on leukemogenesis were measured by western immunoblotting, cell viability, apoptosis, and cell cycle analyses. Results: Here, we have shown that IR triggers the differential expression of miR-27b in murine thymus tissue in a dose-, time- and sex-dependent manner. miR-27b was significantly down-regulated in leukemia cell lines CCL119 and TIB152. Interestingly, ERα was overexpressed in those 2 cell lines, and it was inversely correlated with miR-27b expression. Therefore, we used TIB152 as a model system to determine the role of ERα in miR-27b expression and the contribution of miR-27b to leukemogenesis. β-Estradiol caused a rapid and transient reduction in miR-27b expression reversed by either ERα-neutralizing antibody or ERK1/2 inhibitor. Ectopic expression of miR-27b remarkably suppressed TIB152 cell proliferation, at least in part, by inducing S-phase arrest. In addition, it attenuated the expression of cyclin A2, although it had no effect on the levels of PCNA, PPARγ, CDK2, p21, p27, p-p53, and cleaved caspase-3. Conclusion: Our data reveal that β-estradiol/ERα signaling may contribute to the down-regulation of miR-27b in acute leukemia cell lines through the ERK1/2 pathway, and that miR-27b may function as a tumor

  18. Semiconductor radiation detector

    SciTech Connect (OSTI)

    Bell, Zane W.; Burger, Arnold

    2010-03-30

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

  19. Scintillator Waveguide For Sensing Radiation

    DOE Patents [OSTI]

    Bliss, Mary; Craig, Richard A.; Reeder; Paul L.

    2003-04-22

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  20. Recovery From Radiation-induced Bone Marrow Damage by HSP25 Through Tie2 Signaling

    SciTech Connect (OSTI)

    Lee, Hae-June; Kwon, Hee-Chung; Chung, Hee-Yong; Lee, Yoon-Jin; Lee, Yun-Sil

    2012-09-01

    Purpose: Whole-body radiation therapy can cause severe injury to the hematopoietic system, and therefore it is necessary to identify a novel strategy for overcoming this injury. Methods and Materials: Mice were irradiated with 4.5 Gy after heat shock protein 25 (HSP25) gene transfer using an adenoviral vector. Then, peripheral blood cell counts, histopathological analysis, and Western blotting on bone marrow (BM) cells were performed. The interaction of HSP25 with Tie2 was investigated with mouse OP9 and human BM-derived mesenchymal stem cells to determine the mechanism of HSP25 in the hematopoietic system. Results: HSP25 transfer increased BM regeneration and reduced apoptosis following whole-body exposure to ionizing radiation (IR). The decrease in Tie2 protein expression that followed irradiation of the BM was blocked by HSP25 transfer, and Tie2-positive cells were more abundant among the BM cells of HSP25-transferred mice, even after IR exposure. Following systemic RNA interference of Tie2 before IR, HSP25-mediated radioprotective effects were partially blocked in both mice and cell line systems. Stability of Tie2 was increased by HSP25, a response mediated by the interaction of HSP25 with Tie2. IR-induced tyrosine phosphorylation of Tie2 was augmented by HSP25 overexpression; downstream events in the Tie2 signaling pathway, including phosphorylation of AKT and EKR1/2, were also activated. Conclusions: HSP25 protects against radiation-induced BM damage by interacting with and stabilizing Tie2. This may be a novel strategy for HSP25-mediated radioprotection in BM.

  1. High resolution resonance ionization imaging detector and method

    DOE Patents [OSTI]

    Winefordner, James D.; Matveev, Oleg I.; Smith, Benjamin W.

    1999-01-01

    A resonance ionization imaging device (RIID) and method for imaging objects using the RIID are provided, the RIID system including a RIID cell containing an ionizable vapor including monoisotopic atoms or molecules, the cell being positioned to intercept scattered radiation of a resonance wavelength .lambda..sub.1 from the object which is to be detected or imaged, a laser source disposed to illuminate the RIID cell with laser radiation having a wavelength .lambda..sub.2 or wavelengths .lambda..sub.2, .lambda..sub.3 selected to ionize atoms in the cell that are in an excited state by virtue of having absorbed the scattered resonance laser radiation, and a luminescent screen at the back surface of the RIID cell which presents an image of the number and position of charged particles present in the RIID cell as a result of the ionization of the excited state atoms. The method of the invention further includes the step of initially illuminating the object to be detected or imaged with a laser having a wavelength selected such that the object will scatter laser radiation having the resonance wavelength .lambda..sub.1.

  2. IRS Parking Facility Lighting Retrofit Reduces Annual Energy...

    Office of Environmental Management (EM)

    IRS Parking Facility Lighting Retrofit Reduces Annual Energy Use by 76% IRS Parking Facility Lighting Retrofit Reduces Annual Energy Use by 76% IRS Parking Facility Lighting ...

  3. Improved ARM-SGP TOA OLR Fluxes from GOES-8 IR Radiances Based on CERES Data

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ARM-SGP TOA OLR Fluxes from GOES-8 IR Radiances Based on CERES Data D. R. Doelling and M. M. Khaiyer Analytical Services and Materials, Inc. Hampton, Virginia P. Minnis National Aeronautics and Space Administration Langley Research Center Hampton, Virginia Introduction The radiation budget at the top of the atmosphere (TOA) is a quantity of fundamental importance to the Atmospheric Radiation Measurement (ARM) Program. Thus, it is necessary to measure the radiation budget components, broadband

  4. Ionization photophysics and spectroscopy of cyanoacetylene

    SciTech Connect (OSTI)

    Leach, Sydney; Champion, Norbert; Garcia, Gustavo A.; Fray, Nicolas; Gaie-Levrel, François; Mahjoub, Ahmed; Bénilan, Yves; Gazeau, Marie-Claire; Schwell, Martin

    2014-05-07

    Photoionization of cyanoacetylene was studied using synchrotron radiation over the non-dissociative ionization excitation range 11–15.6 eV, with photoelectron-photoion coincidence techniques. The absolute ionization cross-section and spectroscopic aspects of the parent ion were recorded. The adiabatic ionization energy of cyanoacetylene was measured as 11.573 ± 0.010 eV. A detailed analysis of photoelectron spectra of HC{sub 3}N involves new aspects and new assignments of the vibrational components to excitation of the A{sup 2}Σ{sup +} and B{sup 2}Π states of the cation. Some of the structured autoionization features observed in the 11.94 to 15.5 eV region of the total ion yield (TIY) spectrum were assigned to two Rydberg series converging to the B{sup 2}Π state of HC{sub 3}N{sup +}. A number of the measured TIY features are suggested to be vibrational components of Rydberg series converging to the C{sup 2}Σ{sup +} state of HC{sub 3}N{sup +} at ≈17.6 eV and others to valence shell transitions of cyanoacetylene in the 11.6–15 eV region. The results of quantum chemical calculations of the cation electronic state geometries, vibrational frequencies and energies, as well as of the C–H dissociation potential energy profiles of the ground and electronic excited states of the ion, are compared with experimental observations. Ionization quantum yields are evaluated and discussed and the problem of adequate calibration of photoionization cross-sections is raised.

  5. Filamentation of IR and UV femtosecond pulses upon focusing in air

    SciTech Connect (OSTI)

    Dergachev, A A; Ionin, Andrei A; Kandidov, V P; Seleznev, L V; Sinitsyn, D V; Sunchugasheva, E S; Shlenov, Svyatoslav A

    2013-01-31

    The filamentation of IR and UV laser pulses has been studied numerically and experimentally for different initial beam focusing geometries, and linear electron density profiles along the plasma channel of filaments have been obtained. The results demonstrate that changes in laser beam focusing have a stronger effect on filament and plasma channel parameters for UV radiation than for IR radiation. Focusing causes individual high fluence regions produced by refocusing to merge to form a continuous extended filament with a continuous plasma channel. (nonlinear optical phenomena)

  6. Infrared (IR) photon-sensitive spectromicroscopy in a cryogenic environment

    DOE Patents [OSTI]

    Pereverzev, Sergey

    2016-06-14

    A system designed to suppress thermal radiation background and to allow IR single-photon sensitive spectromicroscopy of small samples by using both absorption, reflection, and emission/luminescence measurements. The system in one embodiment includes: a light source; a plurality of cold mirrors configured to direct light along a beam path; a cold or warm sample holder in the beam path; windows of sample holder (or whole sample holder) are transparent in a spectral region of interest, so they do not emit thermal radiation in the same spectral region of interest; a cold monochromator or other cold spectral device configured to direct a selected fraction of light onto a cold detector; a system of cold apertures and shields positioned along the beam path to prevent unwanted thermal radiation from arriving at the cold monochromator and/or the detector; a plurality of optical, IR and microwave filters positioned along the beam path and configured to adjust a spectral composition of light incident upon the sample under investigation and/or on the detector; a refrigerator configured to maintain the detector at a temperature below 1.0K; and an enclosure configured to: thermally insulate the light source, the plurality of mirrors, the sample holder, the cold monochromator and the refrigerator.

  7. High pressure xenon ionization detector

    DOE Patents [OSTI]

    Markey, John K. (New Haven, CT)

    1989-01-01

    A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization. An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0.degree. to 30.degree. C.

  8. High pressure xenon ionization detector

    DOE Patents [OSTI]

    Markey, J.K.

    1989-11-14

    A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization. An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0 to 30 C. 2 figs.

  9. Optical ionization detector

    DOE Patents [OSTI]

    Wuest, Craig R.; Lowry, Mark E.

    1994-01-01

    An optical ionization detector wherein a beam of light is split so that one arm passes through a fiber optics and the other arm passes through a gas-filled region, and uses interferometry to detect density changes in a gas when charged particles pass through it. The gas-filled region of the detector is subjected to a high electric field and as a charged particle traverses this gas region electrons are freed from the cathode and accelerated so as to generate an electron avalanche which is collected on the anode. The gas density is effected by the electron avalanche formation and if the index or refraction is proportional to the gas density the index will change accordingly. The detector uses this index change by modulating the one arm of the split light beam passing through the gas, with respect to the other arm that is passed through the fiber optic. Upon recombining of the beams, interference fringe changes as a function of the index change indicates the passage of charged particles through the gaseous medium.

  10. Optical ionization detector

    DOE Patents [OSTI]

    Wuest, C.R.; Lowry, M.E.

    1994-03-29

    An optical ionization detector wherein a beam of light is split so that one arm passes through a fiber optics and the other arm passes through a gas-filled region, and uses interferometry to detect density changes in a gas when charged particles pass through it. The gas-filled region of the detector is subjected to a high electric field and as a charged particle traverses this gas region electrons are freed from the cathode and accelerated so as to generate an electron avalanche which is collected on the anode. The gas density is effected by the electron avalanche formation and if the index or refraction is proportional to the gas density the index will change accordingly. The detector uses this index change by modulating the one arm of the split light beam passing through the gas, with respect to the other arm that is passed through the fiber optic. Upon recombining of the beams, interference fringe changes as a function of the index change indicates the passage of charged particles through the gaseous medium. 3 figures.

  11. Pulsed helium ionization detection system

    DOE Patents [OSTI]

    Ramsey, R.S.; Todd, R.A.

    1985-04-09

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  12. Pulsed helium ionization detection system

    DOE Patents [OSTI]

    Ramsey, Roswitha S. (Knoxville, TN); Todd, Richard A. (Knoxville, TN)

    1987-01-01

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  13. Radiative Importance of ThinŽ Liquid Water Clouds

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Program Accomplishments of the Instantaneous Radiative Flux (IRF) Working Group August 2006 AERI Observations at Southern Great Plains Improve Infrared Radiative Transfer Models Turner et al., JAS, 2004 * AERI observations used to evaluate clear sky IR radiative transfer models * Long-term comparisons have improved - Spectral line database parameters - Water vapor continuum absorption models * Reduced errors in computation of downwelling radiative IR flux by approx 4; current uncertainty is on

  14. Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks

    SciTech Connect (OSTI)

    Makarova, Kira S.; Omelchenko, Marina V.; Gaidamakova, Elena K.; Matrosova, Vera Y.; Vasilenko, Alexander; Zhai, Min; Lapidus, Alla; Copeland, Alex; Kim, Edwin; Land, Miriam; Mavrommatis, Konstantinos; Pitluck, Samuel; Richardson, Paul M.; Detter, Chris; Brettin, Thomas; Saunders, Elizabeth; Lai, Barry; Ravel, Bruce; Kemner, Kenneth M.; Wolf, Yuri I.; Sorokin, Alexander; Gerasimova, Anna V.; Gelfand, Mikhail S.; Fredrickson, James K.; Koonin, Eugene V.; Daly, Michael J.

    2007-07-24

    Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at itsoptimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stress-resistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the Deinococcus-Thermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to

  15. Final Report of project entitled "A metabolomics and mouse models approach to study inflammatory and immune responses to radiation"

    SciTech Connect (OSTI)

    Fornace, Albert J.; Li, Henghong

    2013-12-02

    The three-year project entitled ?A Metabolomics and Mouse Models Approach to Study Inflammatory and Immune Responses to Radiation? was initiated in September 2009. The overall objectives of this project were to investigate the acute and persistent effects of low dose radiation on T cell lymphocyte function and physiology, as well the contributions of these cells to radiation-induced inflammatory responses. Inflammation after ionizing radiation (IR), even at low doses, may impact a variety of disease processes, including infectious disease, cardiovascular disease, cancer, and other potentially inflammatory disorders. There were three overall specific aims: 1. To investigate acute and persistent effects of low dose radiation on T cell subsets and function; 2. A genetic approach with mouse models to investigate p38 MAPK pathways that are involved in radiation-induced inflammatory signaling; 3. To investigate the effect of radiation quality on the inflammatory response. We have completed the work proposed in these aims. Below are our major accomplishments: ? Our data show that T cells from low dose irradiated animals have lower proliferation potency and cytokine production upon T cell receptor (TCR) stimulation. This effect was observed as early as 4 hours after radiation, and lasted up to two weeks. ? Using our ultraperformance liquid chromatography coupled with highly sensitive time-of-flight mass spectrometry (UPLC-QTOF) metabolomics method, we demonstrated the global changes of metabolites in T cells upon TCR stimulation in a time-dependent pattern. ? We found that the TCR activation induced metabolome changes are remarkably altered in a dose-dependent manner after radiation. At a dose of 0.5 Gy and above, IR mitigated TCR activation induced metabolome changes while at the dose of as low as 0.1Gy IR had a mild stimulatory effect on some of the metabolome changes. ? We revealed the mechanism for how radiation affects T cell activation by showing that the energy

  16. ARM - Datastreams - goes7ir8

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ir8 Documentation XDC documentation Data Quality Plots ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Datastream : GOES7IR8 GOES-7: infrared, channel 8

  17. Resonance ionization for analytical spectroscopy

    DOE Patents [OSTI]

    Hurst, George S.; Payne, Marvin G.; Wagner, Edward B.

    1976-01-01

    This invention relates to a method for the sensitive and selective analysis of an atomic or molecular component of a gas. According to this method, the desired neutral component is ionized by one or more resonance photon absorptions, and the resultant ions are measured in a sensitive counter. Numerous energy pathways are described for accomplishing the ionization including the use of one or two tunable pulsed dye lasers.

  18. Magnetic reconnection in a weakly ionized plasma

    SciTech Connect (OSTI)

    Leake, James E.; Lukin, Vyacheslav S.; Linton, Mark G.

    2013-06-15

    Magnetic reconnection in partially ionized plasmas is a ubiquitous phenomenon spanning the range from laboratory to intergalactic scales, yet it remains poorly understood and relatively little studied. Here, we present results from a self-consistent multi-fluid simulation of magnetic reconnection in a weakly ionized reacting plasma with a particular focus on the parameter regime of the solar chromosphere. The numerical model includes collisional transport, interaction and reactions between the species, and optically thin radiative losses. This model improves upon our previous work in Leake et al.[“Multi-fluid simulations of chromospheric magnetic reconnection in a weakly ionized reacting plasma,” Astrophys. J. 760, 109 (2012)] by considering realistic chromospheric transport coefficients, and by solving a generalized Ohm's law that accounts for finite ion-inertia and electron-neutral drag. We find that during the two dimensional reconnection of a Harris current sheet with an initial width larger than the neutral-ion collisional coupling scale, the current sheet thins until its width becomes less than this coupling scale, and the neutral and ion fluids decouple upstream from the reconnection site. During this process of decoupling, we observe reconnection faster than the single-fluid Sweet-Parker prediction, with recombination and plasma outflow both playing a role in determining the reconnection rate. As the current sheet thins further and elongates, it becomes unstable to the secondary tearing instability, and plasmoids are seen. The reconnection rate, outflows, and plasmoids observed in this simulation provide evidence that magnetic reconnection in the chromosphere could be responsible for jet-like transient phenomena such as spicules and chromospheric jets.

  19. An Improved Daylight Correction for IR Loss in ARM Diffuse SW Measurements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    An Improved Daylight Correction for IR Loss in ARM Diffuse SW Measurements C. N. Long, K. Younkin, and K. L. Gaustad Pacific Northwest National Laboratory Richland, Washington J. A. Augustine National Oceanic and Atmospheric Administration Air Resources Laboratory Surface Radiation Research Branch Boulder, Colorado Introduction A paper by Cess et al. (2000) notes that some clear-sky diffuse shortwave (SW) measurements they were using from the Atmospheric Radiation Measurement (ARM) Southern

  20. Radiative Heating in Underexplored Bands Campaign (RHUBC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Underexplored Bands Campaign (RHUBC) Feb 22 - Mar 14, 2007 Dave Turner, Eli Mlawer RHUBC Breakout Session ARM Science Team Meeting Monterey, California 27 March 2007 Not a Lot of Time Between IOP and STM! RHUBC Motivation * Radiative cooling due to water vapor in mid- to-upper trop contribute significantly to the dynamical processes and radiative balance the regulate Earth's climate * ~40% of the OLR comes from far-IR (wavelengths > 15 µm) * Far-IR has not been well studied because: -

  1. Broadly tunable picosecond IR source

    DOE Patents [OSTI]

    Campillo, Anthony J.; Hyer, Ronald C.; Shapiro, Stanley J.

    1982-01-01

    A picosecond traveling-wave parametric device capable of controlled spectral bandwidth and wavelength in the infrared is reported. Intense 1.064 .mu.m picosecond pulses (1) pass through a 4.5 cm long LiNbO.sub.3 optical parametric oscillator crystal (2) set at its degeneracy angle. A broad band emerges, and a simple grating (3) and mirror (4) arrangement is used to inject a selected narrow-band into a 2 cm long LiNbO.sub.3 optical parametric amplifier crystal (5) along a second pump line. Typical input energies at 1.064 .mu.m along both pump lines are 6-8 mJ for the oscillator and 10 mJ for the amplifier. This yields 1 mJ of tunable output in the range 1.98 to 2.38 .mu.m which when down-converted in a 1 cm long CdSe crystal mixer (6) gives 2 .mu.J of tunable radiation over the 14.8 to 18.5 .mu.m region. The bandwidth and wavelength of both the 2 and 16 .mu.m radiation output are controlled solely by the diffraction grating.

  2. Broadly tunable picosecond ir source

    DOE Patents [OSTI]

    Campillo, A.J.; Hyer, R.C.; Shapiro, S.L.

    1980-04-23

    A picosecond traveling-wave parametric device capable of controlled spectral bandwidth and wavelength in the infrared is reported. Intense 1.064 ..mu..m picosecond pulses (1) pass through a 4.5 cm long LiNbO/sub 3/ optical parametric oscillator crystal (2) set at its degeneracy angle. A broad band emerges, and a simple grating (3) and mirror (4) arrangement is used to inject a selected narrow-band into a 2 cm long LiNbO/sub 3/ optical parametric amplifier crystal (5) along a second pump line. Typical input energies at 1.064 ..mu..m along both pump lines are 6 to 8 mJ for the oscillator and 10 mJ for the amplifier. This yields 1 mJ of tunable output in the range 1.98 to 2.38 ..mu..m which when down-converted in a 1 cm long CdSe crystal mixer (6) gives 2 ..mu..J of tunable radiation over the 14.8 to 18.5 ..mu..m region. The bandwidth and wavelength of both the 2 and 16 ..mu..m radiation output are controlled solely by the diffraction grating.

  3. Life-span effects of ionizing radiation in the beagle dog: A summary account of four decades of research funded by the US Department of Energy and its predecessor agencies

    SciTech Connect (OSTI)

    Thompson, R.C.

    1989-01-01

    Nearly 40 years ago, the US Atomic Energy Commission made a far- reaching commitment to the support of life-span radiation-effects studies in a relatively long-lived animal, the beagle dog. Something in the range of 200 million dollars has already been spent on a group of closely related experiments, many of which are only now coming to fruition. Responsible fiscal management of these studies, directed toward securing an optimum return from past investments, and toward creative planning of future directions, requires a comprehensive view of this total effort. This report is designed to provide that comprehensive view. This is primarily intended as a research management document. Evaluation and interpretation are tasks for those directly involved in conducting these experiments. The limited objective of the present document is to describe what has been done, to give some of the background for why it was done, to describe results already realized and applications that have been made of these results -- all in a manner designed to display the total effort rather than piecemeal details. While proposing no specific answers to the questions ''Where do we go from here.''it is hoped that the document will provide a basis for approaching that question in an informed manner. The maintenance of a continuity of scientific understanding and direction in these experiments, which often continue beyond the initiating investigators' working life, is no small part of the problem involved in conducting these experiments.

  4. Summary of the Optics, IR, Injection, Operations, Reliability...

    Office of Scientific and Technical Information (OSTI)

    Summary of the Optics, IR, Injection, Operations, Reliability and Instrumentation Working Group Citation Details In-Document Search Title: Summary of the Optics, IR, Injection, ...

  5. IR Spectral Bands and Performance | Open Energy Information

    Open Energy Info (EERE)

    2013 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for IR Spectral Bands and Performance Citation Chris Douglass. IR Spectral Bands...

  6. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, James E.

    1989-01-01

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiation events, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible "chirp". The rate of the "chirps" is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field.

  7. Code of Federal Regulations OCCUPATIONAL RADIATION PROTECTION | Department

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of Energy OCCUPATIONAL RADIATION PROTECTION Code of Federal Regulations OCCUPATIONAL RADIATION PROTECTION The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities. Code of Federal Regulations OCCUPATIONAL RADIATION PROTECTION (329.58 KB) More Documents & Publications Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION Subpart A -

  8. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, Peter B.; Looney, Larry D.

    1993-01-01

    A process for producing an optical fiber having enhanced radiation resitance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation.

  9. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, P.B.; Looney, L.D.

    1993-11-30

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  10. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, J.E.

    1988-03-31

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiatonevents, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible ''chirp''. The rate of the ''chirps'' is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field. 2 figs.

  11. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  12. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, Robert A.; Perez-Mendez, Victor; Kaplan, Selig N.

    1992-01-01

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  13. Enhanced radiation detectors using luminescent materials

    DOE Patents [OSTI]

    Vardeny, Zeev V.; Jeglinski, Stefan A.; Lane, Paul A.

    2001-01-01

    A radiation detecting device comprising a radiation sensing element, and a layer of luminescent material to expand the range of wavelengths over which the sensing element can efficiently detect radiation. The luminescent material being selected to absorb radiation at selected wavelengths, causing the luminescent material to luminesce, and the luminescent radiation being detected by the sensing element. Radiation sensing elements include photodiodes (singly and in arrays), CCD arrays, IR detectors and photomultiplier tubes. Luminescent materials include polymers, oligomers, copolymers and porphyrines, Luminescent layers include thin films, thicker layers, and liquid polymers.

  14. One-photon mass-analyzed threshold ionization (MATI) spectroscopy of pyridine: Determination of accurate ionization energy and cationic structure

    SciTech Connect (OSTI)

    Lee, Yu Ran; Kang, Do Won; Kim, Hong Lae E-mail: hlkim@kangwon.ac.kr; Kwon, Chan Ho E-mail: hlkim@kangwon.ac.kr

    2014-11-07

    Ionization energies and cationic structures of pyridine were intensively investigated utilizing one-photon mass-analyzed threshold ionization (MATI) spectroscopy with vacuum ultraviolet radiation generated by four-wave difference frequency mixing in Kr. The present one-photon high-resolution MATI spectrum of pyridine demonstrated a much finer and richer vibrational structure than that of the previously reported two-photon MATI spectrum. From the MATI spectrum and photoionization efficiency curve, the accurate ionization energy of the ionic ground state of pyridine was confidently determined to be 73 570 ± 6 cm{sup −1} (9.1215 ± 0.0007 eV). The observed spectrum was almost completely assigned by utilizing Franck-Condon factors and vibrational frequencies calculated through adjustments of the geometrical parameters of cationic pyridine at the B3LYP/cc-pVTZ level. A unique feature unveiled through rigorous analysis was the prominent progression of the 10 vibrational mode, which corresponds to in-plane ring bending, and the combination of other totally symmetric fundamentals with the ring bending overtones, which contribute to the geometrical change upon ionization. Notably, the remaining peaks originate from the upper electronic state ({sup 2}A{sub 2}), as predicted by high-resolution photoelectron spectroscopy studies and symmetry-adapted cluster configuration interaction calculations. Based on the quantitatively good agreement between the experimental and calculated results, it was concluded that upon ionization the pyridine cation in the ground electronic state should have a planar structure of C{sub 2v} symmetry through the C-N axis.

  15. Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Subpart A - General Provisions | Department of Energy PART 835-OCCUPATIONAL RADIATION PROTECTION Subpart A - General Provisions Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION Subpart A - General Provisions The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities. Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION

  16. Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy PART 835-OCCUPATIONAL RADIATION PROTECTION Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION General. The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities. Code of Federal Regulations PART 835-OCCUPATIONAL RADIATION PROTECTION (127.39 KB) More Documents & Publications Order Module--NNSA OCCUPATIONAL

  17. Measurements of High-Intensity Laser Induced Ionizing Radiation...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  18. Measurements of High-Intensity Laser Induced Ionizing Radiation...

    Office of Scientific and Technical Information (OSTI)

    APA Chicago Bibtex Export Metadata Endnote Excel CSV XML Save to My Library Send to Email Send to Email Email address: Content: Close Send Cite: MLA Format Close Cite: APA ...

  19. Dwarf Galaxies with Ionizing Radiation Feedback II: Spatially...

    Office of Scientific and Technical Information (OSTI)

    Astrophys. ; Goldbaum, Nathan J. ; UC, Santa Cruz, Astron. Astrophys. ; Abel, Tom ; KIPAC, Menlo Park Publication Date: 2013-10-21 OSTI Identifier: 1097423 Report Number(s): ...

  20. Review of using gallium nitride for ionizing radiation detection...

    Office of Scientific and Technical Information (OSTI)

    Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210, USA, Department of Radiology, Stanford University, ...

  1. Alpha Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Basics of Radiation Gamma Radiation and X-Rays Beta Radiation Alpha Radiation Irradiation Radioactive Contamination Definitions Detection Measurement Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Basics of Radiation Characteristics of Alpha Radiation 1. Alpha radiation is not able to penetrate skin. 2. Alpha-emitting materials can be harmful to humans if the materials are inhaled, swallowed, or absorbed through open wounds. 3. A variety of instruments

  2. Radiative Heating in Underexplored Bands Campaign (RHUBC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bands Campaign (RHUBC) D. Turner and E. Mlawer RHUBC Breakout Session 2008 ARM Science Team Meeting 13 March, 2008 Norfolk, Virginia Motivation * Radiative heating/cooling in the mid-troposphere modulate the vertical motions of the atmosphere - This heating/cooling occurs primarily in water vapor absorption bands that are opaque at the surface * Approximately 40% of the OLR comes from the far-IR * Until recently, the observational tools were not available to evaluate the accuracy of the far-IR

  3. RADIATION DETECTING AND TELEMETERING SYSTEM

    DOE Patents [OSTI]

    Richards, H.K.

    1959-12-15

    A system is presented for measuring ionizing radiation at several remote stations and transmitting the measured information by radio to a central station. At each remote station a signal proportioned to the counting rate is applied across an electrical condenser made of ferroelectric material. The voltage across the condenser will vary as a function of the incident radiation and the capacitance of the condenser will vary accordingly. This change in capacitance is used to change the frequency of a crystalcontrolled oscillator. The output of the oscillator is coupled to an antenna for transmitting a signal proportional to the incident radiation.

  4. Ultraviolet radiation induced discharge laser

    DOE Patents [OSTI]

    Gilson, Verle A.; Schriever, Richard L.; Shearer, James W.

    1978-01-01

    An ultraviolet radiation source associated with a suitable cathode-anode electrode structure, disposed in a gas-filled cavity of a high pressure pulsed laser, such as a transverse electric atmosphere (TEA) laser, to achieve free electron production in the gas by photoelectric interaction between ultraviolet radiation and the cathode prior to the gas-exciting cathode-to-anode electrical discharge, thereby providing volume ionization of the gas. The ultraviolet radiation is produced by a light source or by a spark discharge.

  5. Atmospheric sampling glow discharge ionization source

    DOE Patents [OSTI]

    McLuckey, S.A.; Glish, G.L.

    1989-07-18

    An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above. 3 figs.

  6. Atmospheric sampling glow discharge ionization source

    DOE Patents [OSTI]

    McLuckey, Scott A. (Oak Ridge, TN); Glish, Gary L. (Oak Ridge, TN)

    1989-01-01

    An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above.

  7. Audible radiation monitor

    DOE Patents [OSTI]

    Odell, Daniel M. C.

    1993-01-01

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

  8. High-resolution ionization detector and array of such detectors

    DOE Patents [OSTI]

    McGregor, Douglas S. (Ypsilanti, MI); Rojeski, Ronald A. (Pleasanton, CA)

    2001-01-16

    A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.

  9. Atmospheric Ionization Mass Spectrometry Capabilities at Sandia...

    Office of Scientific and Technical Information (OSTI)

    Mass Spectrometry Capabilities at Sandia National Labs. Citation Details In-Document Search Title: Atmospheric Ionization Mass Spectrometry Capabilities at Sandia National Labs. ...

  10. Ionization probes of molecular structure and chemistry

    SciTech Connect (OSTI)

    Johnson, P.M.

    1993-12-01

    Various photoionization processes provide very sensitive probes for the detection and understanding of the spectra of molecules relevant to combustion processes. The detection of ionization can be selective by using resonant multiphoton ionization or by exploiting the fact that different molecules have different sets of ionization potentials. Therefore, the structure and dynamics of individual molecules can be studied even in a mixed sample. The authors are continuing to develop methods for the selective spectroscopic detection of molecules by ionization, and to use these methods for the study of some molecules of combustion interest.

  11. Identification of a Previously Unobserved Dissociative Ionization...

    Office of Scientific and Technical Information (OSTI)

    Identification of a Previously Unobserved Dissociative Ionization Pathway in Time-Resolved Photospectroscopy of the Deuterium Molecule Not Available Temp HTML Storage 2: Cao, Wei; ...

  12. Theory of multiphoton and tunnel ionization in a bichromatic field

    SciTech Connect (OSTI)

    Bagulov, D. S.; Kotelnikov, I. A.

    2013-01-15

    The imaginary-time method [6, 7] is used to calculate the multiphoton and tunnel ionization probabilities for atoms in a laser radiation field part of which is converted into the second harmonic. We assume that the first harmonic has a linear or elliptical polarization and the second harmonic is polarized linearly, with its polarization vector making an arbitrary angle with that of the first harmonic. The mean momentum of the photoelectrons knocked out from atoms is shown to depend on the phase shift between the first and second harmonics and their mutual polarization and to be identically equal to zero for a monochromatic field. An important difference between the case of elliptical polarization and the case of linear polarization of both harmonics is the absence of conditions under which the conditions for dominance of one of the two generation mechanisms considered here can be identified during the generation of terahertz radiation from the region of optical breakdown in a gas.

  13. Comparative study of ionization chamber detectors vis-a-vis a CCD detector for dispersive XAS measurement in transmission geometry

    SciTech Connect (OSTI)

    Poswal, A. K.; Agrawal, A.; Bhattachryya, D.; Jha, S. N.; Sahoo, N. K.

    2013-02-05

    We have designed and fabricated parallel plate ionization chamber detectors and voltage vs. current characteristics (V-I curve) of the detectors were recorded with synchrotron radiation to qualify for use in X-ray Absorption Spectroscopy (XAS) measurements. After qualifying the ionization chambers, the detectors were used in the dispersive EXAFS beamline (BL-08) at INDUS-2 SRS in Turbo-XAS geometry. Using the same setup and under the same setting, XAS spectra were also recorded with a CCD detector and the observation on relative performance of the ionization chamber vis-a-vis the CCD detector is presented in this paper.

  14. Method for the depth corrected detection of ionizing events from a co-planar grids sensor

    DOE Patents [OSTI]

    De Geronimo, Gianluigi; Bolotnikov, Aleksey E.; Carini, Gabriella

    2009-05-12

    A method for the detection of ionizing events utilizing a co-planar grids sensor comprising a semiconductor substrate, cathode electrode, collecting grid and non-collecting grid. The semiconductor substrate is sensitive to ionizing radiation. A voltage less than 0 Volts is applied to the cathode electrode. A voltage greater than the voltage applied to the cathode is applied to the non-collecting grid. A voltage greater than the voltage applied to the non-collecting grid is applied to the collecting grid. The collecting grid and the non-collecting grid are summed and subtracted creating a sum and difference respectively. The difference and sum are divided creating a ratio. A gain coefficient factor for each depth (distance between the ionizing event and the collecting grid) is determined, whereby the difference between the collecting electrode and the non-collecting electrode multiplied by the corresponding gain coefficient is the depth corrected energy of an ionizing event. Therefore, the energy of each ionizing event is the difference between the collecting grid and the non-collecting grid multiplied by the corresponding gain coefficient. The depth of the ionizing event can also be determined from the ratio.

  15. Los Alamos Science: Number 23, 1995. Radiation protection and the human radiation experiments

    SciTech Connect (OSTI)

    Cooper, N.G.

    1995-12-31

    There are a variety of myths and misconceptions about the ionizing radiation that surrounds and penetrates us all. Dispel a few of these by taking a leisurely tour of radiation and its properties, of the natural and man-made sources of ionizing radiation, and of the way doses are calculated. By damaging DNA and inducing genetic mutations, ionizing radiation can potentially initiate a cell on the road to cancer. The authors review what is currently known about regulation of cellular reproduction, DNA damage and repair, cellular defense mechanisms, and the specific cancer-causing genes that are susceptible to ionizing radiation. A rapid survey of the data on radiation effects in humans shows that high radiation doses increase the risk of cancer, whereas the effects of low doses are very difficult to detect. The hypothetical risks at low doses, which are estimated from the atomic-bomb survivors, are compared to the low-dose data so that the reader can assess the present level of uncertainty. As part of the openness initiative, ten individuals who have worked with plutonium during various periods in the Laboratory`s history were asked to share their experiences including their accidental intakes. The history and prognosis of people who have had plutonium exposures is discussed by the Laboratory`s leading epidemiologist.

  16. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, R.F. Jr.

    1994-12-13

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

  17. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  18. Gated IR Images of Shocked Surfaces

    SciTech Connect (OSTI)

    S. S. Lutz; W. D. Turley; P. M. Rightley; L. E. Primas

    2001-06-01

    Gated infrared (IR) images have been taken of a series of shocked surface geometries in tin. Metal coupons machined with steps and flats were mounted directly to the high explosive. The explosive was point-initiated and 500-ns to 1-microsecond-wide gated images of the target were taken immediately following shock breakout using a Santa Barbara Focalplane InSb camera (SBF-134). Spatial distributions of surface radiance were extracted from the images of the shocked samples and found to be non-single-valued. Several geometries were modeled using CTH, a two-dimensional Eulerian hydrocode.

  19. Spin orientations of the spin-half Ir4+ ions in Sr3NiIrO6, Sr2IrO4 and Na2IrO3: Density functional, perturbation theory and Madelung potential analyses

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gordon, Elijah E.; Xiang, Hongjun; Koehler, Jurgen; Whangbo, Myung -Hwan

    2016-03-01

    The spins of the low-spin Ir4+ (S = 1/2, d5) ions at the octahedral sites of the oxides Sr3NiIrO6, Sr2IrO4 and Na2IrO3 exhibit preferred orientations with respect to their IrO6 octahedra. We evaluated the magnetic anisotropies of these S = 1/2 ions on the basis of DFT calculations including spin-orbit coupling (SOC), and probed their origin by performing perturbation theory analyses with SOC as perturbation within the LS coupling scheme. The observed spin orientations of Sr3NiIrO6 and Sr2IrO4 are correctly predicted by DFT calculations, and are accounted for by the perturbation theory analysis. As for the spin orientation of Na2IrO3,more » both experimental studies and DFT calculations have not been unequivocal. Our analysis reveals that the Ir4+ spin orientation of Na2IrO3 should have nonzero components along the c- and a-axes directions. The spin orientations determined by DFT calculations are sensitive to the accuracy of the crystal structures employed, which is explained by perturbation theory analyses when interactions between adjacent Ir4+ ions are taken into consideration. There are indications implying that the 5d electrons of Na2IrO3 are less strongly localized compared with those of Sr3NiIrO6 and Sr2IrO4. This implication was confirmed by showing that the Madelung potentials of the Ir4+ ions are less negative in Na2IrO3 than in Sr3NiIrO6, Sr2IrO4. Most transition-metal S = 1/2 ions do have magnetic anisotropies because the SOC induces interactions among their crystal-field split d-states, and the associated mixing of the states modifies only the orbital parts of the states. This finding cannot be mimicked by a spin Hamiltonian because this model Hamiltonian lacks the orbital degree of freedom, thereby leading to the spin-half syndrome. As a result, the spin-orbital entanglement for the 5d spin-half ions Ir4+ is not as strong as has been assumed lately.« less

  20. Final Report: Ionization chemistry of high temperature molecular...

    Office of Scientific and Technical Information (OSTI)

    Final Report: Ionization chemistry of high temperature molecular fluids Citation Details In-Document Search Title: Final Report: Ionization chemistry of high temperature molecular ...

  1. Laser Ionized Preformed Plasma at FACET (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Conference: Laser Ionized Preformed Plasma at FACET Citation Details In-Document Search Title: Laser Ionized Preformed Plasma at FACET You are accessing a document from the ...

  2. Remote radiation dosimetry

    DOE Patents [OSTI]

    Braunlich, P.F.; Tetzlaff, W.; Hegland, J.E.; Jones, S.C.

    1991-03-12

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via a transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission. 8 figures.

  3. AREA RADIATION MONITOR

    DOE Patents [OSTI]

    Manning, F.W.; Groothuis, S.E.; Lykins, J.H.; Papke, D.M.

    1962-06-12

    S>An improved area radiation dose monitor is designed which is adapted to compensate continuously for background radiation below a threshold dose rate and to give warning when the dose integral of the dose rate of an above-threshold radiation excursion exceeds a selected value. This is accomplished by providing means for continuously charging an ionization chamber. The chamber provides a first current proportional to the incident radiation dose rate. Means are provided for generating a second current including means for nulling out the first current with the second current at all values of the first current corresponding to dose rates below a selected threshold dose rate value. The second current has a maximum value corresponding to that of the first current at the threshold dose rate. The excess of the first current over the second current, which occurs above the threshold, is integrated and an alarm is given at a selected integrated value of the excess corresponding to a selected radiation dose. (AEC)

  4. Remote radiation dosimetry

    DOE Patents [OSTI]

    Braunlich, Peter F.; Tetzlaff, Wolfgang; Hegland, Joel E.; Jones, Scott C.

    1991-01-01

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission.

  5. RADIATION DOSIMETER AND DOSIMETRIC METHODS

    DOE Patents [OSTI]

    Taplin, G.V.

    1958-10-28

    The determination of ionizing radiation by means of single fluid phase chemical dosimeters of the colorimetric type is presented. A single fluid composition is used consisting of a chlorinated hydrocarbon, an acidimetric dye, a normalizer and water. Suitable chlorinated hydrocarbons are carbon tetrachloride, chloroform, trichloroethylene, trichlorethane, ethylene dichioride and tetracbloroethylene. Suitable acidimetric indicator dyes are phenol red, bromcresol purple, and creosol red. Suitable normallzers are resorcinol, geraniol, meta cresol, alpha -tocopberol, and alpha -naphthol.

  6. Nevada Test Site Radiation Protection Program

    SciTech Connect (OSTI)

    Radiological Control Managers' Council, Nevada Test Site

    2007-08-09

    Title 10 Code of Federal Regulations (CFR) 835, 'Occupational Radiation Protection', establishes radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of U.S. Department of Energy (DOE) activities. 10 CFR 835.101(a) mandates that DOE activities be conducted in compliance with a documented Radiation Protection Program (RPP) as approved by DOE. This document promulgates the RPP for the Nevada Test Site (NTS), related (onsite or offsite) DOE National Nuclear Security Administration Nevada Site Office (NNSA/NSO) operations, and environmental restoration offsite projects.

  7. Ionization of Rb Rydberg atoms in the attractive nsnp dipole-dipole potential

    SciTech Connect (OSTI)

    Park, Hyunwook; Shuman, E. S.; Gallagher, T. F.

    2011-11-15

    We have observed the ionization of a cold gas of Rb Rydberg atoms which occurs when nsns van der Waals pairs of ns atoms of n{approx_equal} 40 on a weakly repulsive potential are transferred to an attractive dipole-dipole nsnp potential by a microwave transition. Comparing the measurements to a simple model shows that the initial 300-{mu}K thermal velocity of the atoms plays an important role. Excitation to a repulsive dipole-dipole potential does not lead to more ionization on a 15-{mu}s time scale than leaving the atoms in the weakly repulsive nsns state. This observation is slightly surprising since a radiative transition must occur to allow ionization in the latter case. Finally, by power broadening of the microwave transition, to allow transitions from the initial nsns state to the nsnp state over a broad range of internuclear spacings, it is possible to accelerate markedly the evolution to a plasma.

  8. Pigments which reflect infrared radiation from fire

    DOE Patents [OSTI]

    Berdahl, Paul H.

    1998-01-01

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer (.mu.m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 .mu.m or, for cool smoky fires, about 2 .mu.m to about 16 .mu.m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 .mu.m to about 2 .mu.m and thin leafing aluminum flake pigments.

  9. Pigments which reflect infrared radiation from fire

    DOE Patents [OSTI]

    Berdahl, P.H.

    1998-09-22

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer ({micro}m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 {micro}m or, for cool smoky fires, about 2 {micro}m to about 16 {micro}m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 {micro}m to about 2 {micro}m and thin leafing aluminum flake pigments. 4 figs.

  10. IY:ILrnr IR-rl?l'

    Office of Legacy Management (LM)

    IY:ILrnr IR-rl?l' w&m PadmmmTuJ tmml' aIs~#l!REm m-t, - 188kwxm BYI alahard 0. cr*rrror cy- r' , ' .~ -' - -' ^ , /' cs< 4. .c :' ; *. .h,- ' (z&&y .' ,/ ;f. .* &J >l a. L \' P" ,,,' ,.' I * :{' \ !' l t ..b c&~ tf ~ , r ,, r. ,* .;;;., k J ;, b $y$' Lrmprrw)rlt&tmxJ- a@. Frqrr at t&i8 raoLli:.y SC\ daummiI~Luualndr8rr~lfCUIf@@?~~oy-~ d )I t rq ,i .* 1 Virium~~bUrlJlOgarspvlr at ma rdutw. (500 p-4 3) i" 1 ) ,ip" 2. rt A8 - u %I* mm

  11. (Resonance ionization spectroscopy and its applications)

    SciTech Connect (OSTI)

    Ramsey, J.M.

    1990-10-11

    The Fifth International Symposium in Resonance Ionization Spectroscopy and Its Applications was attended. The Joint Research Centre of the European Communities at Ispra, Italy was also visited. The traveler presented an invited talk, chaired a meeting session and gave an impromptu presentation on how current laser technology limits the development of commercial instrumentation based upon Resonance Ionization Spectroscopy. The conference was truely international with scientists from 19 countries and less than 1/4 from the US. The meeting also provided a health mixture of experimentalists and theoreticians. Technical developments reported included the use of electric field ionization from laser prepared Rydberg states as a way to reduce background signals and commercial development of an optical parametric oscillator for replacing pulsed dye laser. A speaker from the Soviet Union suggested their willingness to market hardware they have developed based upon the resonance ionization technique.

  12. Gas amplified ionization detector for gas chromatography

    DOE Patents [OSTI]

    Huston, Gregg C.

    1992-01-01

    A gas-amplified ionization detector for gas chromatrography which possesses increased sensitivity and a very fast response time. Solutes eluding from a gas chromatographic column are ionized by UV photoionization of matter eluting therefrom. The detector is capable of generating easily measured voltage signals by gas amplification/multiplication of electron products resulting from the UV photoionization of at least a portion of each solute passing through the detector.

  13. Graphene oxide/carbon nanoparticle thin film based IR detector: Surface properties and device characterization

    SciTech Connect (OSTI)

    Chowdhury, Farzana Aktar; Hossain, Mohammad Abul; Uchida, Koji; Tamura, Takahiro; Sugawa, Kosuke; Mochida, Tomoaki; Otsuki, Joe; Mohiuddin, Tariq; Boby, Monny Akter; Alam, Mohammad Sahabul

    2015-10-15

    This work deals with the synthesis, characterization, and application of carbon nanoparticles (CNP) adorned graphene oxide (GO) nanocomposite materials. Here we mainly focus on an emerging topic in modern research field presenting GO-CNP nanocomposite as a infrared (IR) radiation detector device. GO-CNP thin film devices were fabricated from liquid phase at ambient condition where no modifying treatments were necessary. It works with no cooling treatment and also for stationary objects. A sharp response of human body IR radiation was detected with time constants of 3 and 36 sec and radiation responsivity was 3 mAW{sup −1}. The current also rises for quite a long time before saturation. This work discusses state-of-the-art material developing technique based on near-infrared photon absorption and their use in field deployable instrument for real-world applications. GO-CNP-based thin solid composite films also offer its potentiality to be utilized as p-type absorber material in thin film solar cell, as well.

  14. Medical Applications of Synchrotron Radiation

    DOE R&D Accomplishments [OSTI]

    Thomlinson, W.

    1991-10-01

    Ever since the first diagnostic x-ray was done in the United States on February 3, 1896, the application of ionizing radiation to the field of medicine has become increasingly important. Both in clinical medicine and basic research the use of x-rays for diagnostic imaging and radiotherapy is now widespread. Radiography, angiography, CAT and PETT scanning, mammography, and nuclear medicine are all examples of technologies developed to image the human anatomy. In therapeutic applications, both external and internal sources of radiation are applied to the battle against cancer. The development of dedicated synchrotron radiation sources has allowed exciting advances to take place in many of these applications. The new sources provide tunable, high-intensity monochromatic beams over a wide range of energies which can be tailored to specific programmatic needs. This paper surveys those areas of medical research in which synchrotron radiation facilities are actively involved.

  15. Photodetectors with passive thermal radiation control

    DOE Patents [OSTI]

    Lin, Shawn-Yu; Fleming, James G.; Dodson, Brian W.

    2001-10-02

    A new class of photodetectors which include means for passive shielding against undesired thermal radiation is disclosed. Such devices can substitute in applications currently requiring cooled optical sensors, such as IR detection and imaging. This description is included for purposes of searching, and is not intended to limit or otherwise influence the interpretation of the present invention.

  16. Summary of the Optics, IR, Injection, Operations, Reliability...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Summary of the Optics, IR, Injection, Operations, Reliability and Instrumentation Working Group Citation Details In-Document Search Title: Summary of the Optics, ...

  17. Ir-based alloys for ultra-high temperature applications

    DOE Patents [OSTI]

    Liu, Chain T.; George, Easo P.; Bloom, Everett E.

    2006-01-03

    An alloy composition includes, in atomic percent: about 1 to about 10% of at least one element selected from the group consisting of Zr and Hf, balance Ir.

  18. X-ray transient absorption and picosecond IR spectroscopy of...

    Office of Scientific and Technical Information (OSTI)

    X-ray transient absorption and picosecond IR spectroscopy of fulvalene(tetracarbonyl)diruthenium on photoexcitation Citation Details In-Document Search Title: X-ray transient ...

  19. NEAR-IR TWO PHOTON MICROSCOPY IMAGING OF SILICA NANOPARTICLES...

    Office of Scientific and Technical Information (OSTI)

    NANOPARTICLES FUNCTIONALIZED WITH ISOLATED SENSITIZED Yb(III) CENTERS Citation Details In-Document Search Title: NEAR-IR TWO PHOTON MICROSCOPY IMAGING OF SILICA NANOPARTICLES ...

  20. Graphene-silicon layered structures on single-crystalline Ir...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Graphene-silicon layered structures on single-crystalline Ir(111) thin films Prev Next Title: Graphene-silicon layered structures on single-crystalline...

  1. Radiation Counters

    DOE Patents [OSTI]

    Simpson, Jr, J A

    1950-01-31

    Geiger-Mueller and proportional counters operating at low potentials (about 125-300 v) obtained by utilizing certain ratios of diameters of the electrodes and particular mixtures of noble gases as the ionizing medium are covered in this application.

  2. Beta Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Beta Radiation 1. Beta radiation may travel meters in air and is moderately penetrating. 2. Beta radiation can penetrate human skin to the "germinal layer," where new skin cells ...

  3. Radiation Tolerance of 65nm CMOS Transistors

    SciTech Connect (OSTI)

    Krohn, M.; Bentele, B.; Christian, D. C.; Cumalat, J. P.; Deptuch, G.; Fahim, F.; Hoff, J.; Shenai, A.; Wagner, S. R.

    2015-12-11

    We report on the effects of ionizing radiation on 65 nm CMOS transistors held at approximately -20C during irradiation. The pattern of damage observed after a total dose of 1 Grad is similar to damage reported in room temperature exposures, but we observe less damage than was observed at room temperature.

  4. Radiation Tolerance of 65nm CMOS Transistors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Krohn, M.; Bentele, B.; Christian, D. C.; Cumalat, J. P.; Deptuch, G.; Fahim, F.; Hoff, J.; Shenai, A.; Wagner, S. R.

    2015-12-11

    We report on the effects of ionizing radiation on 65 nm CMOS transistors held at approximately -20°C during irradiation. The pattern of damage observed after a total dose of 1 Grad is similar to damage reported in room temperature exposures, but we observe less damage than was observed at room temperature.

  5. IR keeps coal miners safe and reduces downtime

    SciTech Connect (OSTI)

    Massey, L.G.

    2009-01-15

    Infrared (IR) cameras can inspect the direct current trolley system that powers mantrips and locomotives that transport men and supplies to an underground mine. If trolley insulators become shorted or electrically leaky they can heat the roof and cause a fire or cave-in. The article explains how IR inspection works and describes typical problems that can be identified by thermograms. 8 figs.

  6. Simultaneous multi-beam planar array IR (pair) spectroscopy

    DOE Patents [OSTI]

    Elmore, Douglas L.; Rabolt, John F.; Tsao, Mei-Wei

    2005-09-13

    An apparatus and method capable of providing spatially multiplexed IR spectral information simultaneously in real-time for multiple samples or multiple spatial areas of one sample using IR absorption phenomena requires no moving parts or Fourier Transform during operation, and self-compensates for background spectra and degradation of component performance over time. IR spectral information and chemical analysis of the samples is determined by using one or more IR sources, sampling accessories for positioning the samples, optically dispersive elements, a focal plane array (FPA) arranged to detect the dispersed light beams, and a processor and display to control the FPA, and display an IR spectrograph. Fiber-optic coupling can be used to allow remote sensing. Portability, reliability, and ruggedness is enhanced due to the no-moving part construction. Applications include determining time-resolved orientation and characteristics of materials, including polymer monolayers. Orthogonal polarizers may be used to determine certain material characteristics.

  7. NaIrO3A Pentavalent Post-perovskite

    SciTech Connect (OSTI)

    M Bremholm; S Dutton; P Stephens; R Cava

    2011-12-31

    Sodium iridium (V) oxide, NaIrO{sub 3}, was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO{sub 3}, the much-studied structural analog of the high-pressure post-perovskite phase of MgSiO{sub 3}. Among the oxide post-perovskites, NaIrO{sub 3} is the first example with a pentavalent cation. The structure consists of layers of corner- and edge-sharing IrO{sub 6} octahedra separated by layers of NaO{sub 8} bicapped trigonal prisms. NaIrO{sub 3} shows no magnetic ordering and resistivity measurements show non-metallic behavior. The crystal structure, electrical and magnetic properties are discussed and compared to known post-perovskites and pentavalent perovskite metal oxides.

  8. Multiphoton ionization of large water clusters

    SciTech Connect (OSTI)

    Apicella, B.; Li, X.; Passaro, M.; Spinelli, N.; Wang, X.

    2014-05-28

    Water clusters are multimers of water molecules held together by hydrogen bonds. In the present work, multiphoton ionization in the UV range coupled with time of flight mass spectrometry has been applied to water clusters with up to 160 molecules in order to obtain information on the electronic states of clusters of different sizes up to dimensions that can approximate the bulk phase. The dependence of ion intensities of water clusters and their metastable fragments produced by laser ionization at 355 nm on laser power density indicates a (3+1)-photon resonance-enhanced multiphoton ionization process. It also explains the large increase of ionization efficiency at 355 nm compared to that at 266 nm. Indeed, it was found, by applying both nanosecond and picosecond laser ionization with the two different UV wavelengths, that no water cluster sequences after n = 9 could be observed at 266 nm, whereas water clusters up to m/z 2000 Th in reflectron mode and m/z 3000 Th in linear mode were detected at 355 nm. The agreement between our findings on clusters of water, especially true in the range with n > 10, and reported data for liquid water supports the hypothesis that clusters above a critical dimension can approximate the liquid phase. It should thus be possible to study clusters just above 10 water molecules, for getting information on the bulk phase structure.

  9. Synchrotron IR microspectroscopy for protein structure analysis: Potential and questions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yu, Peiqiang

    2006-01-01

    Synchrotron radiation-based Fourier transform infrared microspectroscopy (S-FTIR) has been developed as a rapid, direct, non-destructive, bioanalytical technique. This technique takes advantage of synchrotron light brightness and small effective source size and is capable of exploring the molecular chemical make-up within microstructures of a biological tissue without destruction of inherent structures at ultra-spatial resolutions within cellular dimension. To date there has been very little application of this advanced technique to the study of pure protein inherent structure at a cellular level in biological tissues. In this review, a novel approach was introduced to show the potential of the newly developed, advancedmore » synchrotron-based analytical technology, which can be used to localize relatively “pure“ protein in the plant tissues and relatively reveal protein inherent structure and protein molecular chemical make-up within intact tissue at cellular and subcellular levels. Several complex protein IR spectra data analytical techniques (Gaussian and Lorentzian multi-component peak modeling, univariate and multivariate analysis, principal component analysis (PCA), and hierarchical cluster analysis (CLA) are employed to relatively reveal features of protein inherent structure and distinguish protein inherent structure differences between varieties/species and treatments in plant tissues. By using a multi-peak modeling procedure, RELATIVE estimates (but not EXACT determinations) for protein secondary structure analysis can be made for comparison purpose. The issues of pro- and anti-multi-peaking modeling/fitting procedure for relative estimation of protein structure were discussed. By using the PCA and CLA analyses, the plant molecular structure can be qualitatively separate one group from another, statistically, even though the spectral assignments are not known. The synchrotron-based technology provides a new approach for protein structure research in

  10. Radiation Emergency Assistance Center / Training Site | National Nuclear

    National Nuclear Security Administration (NNSA)

    Security Administration | (NNSA) Radiation Emergency Assistance Center / Training Site NNSA's Radiation Emergency Assistance Center / Training Site (REAC/TS) is on-call 24 hours a day, to provide medical REACTS logo care or consultative assistance involving the exposure to ionizing radiation or radiological contamination. REAC/TS, located in Methodist Medical Center of Oak Ridge in Oak Ridge, Tennessee, was established in 1976 and has assisted in more than 2,400 calls for assistance

  11. Capillary electrophoresis electrospray ionization mass spectrometry interface

    DOE Patents [OSTI]

    Smith, Richard D.; Severs, Joanne C.

    1999-01-01

    The present invention is an interface between a capillary electrophoresis separation capillary end and an electrospray ionization mass spectrometry emitter capillary end, for transporting an anolyte sample from a capillary electrophoresis separation capillary to a electrospray ionization mass spectrometry emitter capillary. The interface of the present invention has: (a) a charge transfer fitting enclosing both of the capillary electrophoresis capillary end and the electrospray ionization mass spectrometry emitter capillary end; (b) a reservoir containing an electrolyte surrounding the charge transfer fitting; and (c) an electrode immersed into the electrolyte, the electrode closing a capillary electrophoresis circuit and providing charge transfer across the charge transfer fitting while avoiding substantial bulk fluid transfer across the charge transfer fitting. Advantages of the present invention have been demonstrated as effective in providing high sensitivity and efficient analyses.

  12. Memory in Nonlinear Ionization of Transparent Solids

    SciTech Connect (OSTI)

    Rajeev, P. P.; Simova, E.; Hnatovsky, C.; Taylor, R. S.; Rayner, D. M.; Corkum, P. B.; Gertsvolf, M.; Bhardwaj, V. R.

    2006-12-22

    We demonstrate a shot-to-shot reduction in the threshold laser intensity for ionization of bulk glasses illuminated by intense femtosecond pulses. For SiO{sub 2} the threshold change serves as positive feedback reenforcing the process that produced it. This constitutes a memory in nonlinear ionization of the material. The threshold change saturates with the number of pulses incident at a given spot. Irrespective of the pulse energy, the magnitude of the saturated threshold change is constant ({approx}20%). However, the number of shots required to reach saturation does depend on the pulse energy. Recognition of a memory in ionization is vital to understand multishot optical or electrical breakdown phenomena in dielectrics.

  13. Resonance ionization spectroscopy of zirconium atoms

    SciTech Connect (OSTI)

    Page, R.H.; Dropinski, S.C.; Worden, E.F. Jr.; Stockdale, J.A.D.

    1992-05-01

    We have examined the stepwise-resonant three-photon-ionization spectrum of neutral zirconium atoms using three separately-tunable pulsed visible dye lasers. Lifetimes of even-parity levels (measured with delayed-photoionization technique) range from 10 to 100 nsec. Direct ionization cross sections appear to be less than 10{sup {minus}17} cm{sup 2}; newly-detected autoionizing levels give peak ionization cross sections (inferred from saturation fluences) up to 10{sup {minus}15} cm{sup 2}. Members of Rydberg series converging to the 315 and 1323 cm{sup {minus}1} levels of Zr{sup +} were identified. ``Clumps`` of autoionizing levels are thought to be due to Rydberg-valence mixing.

  14. Ionization-chamber smoke detector system

    DOE Patents [OSTI]

    Roe, Robert F.

    1976-10-19

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system is designed to reduce false alarms caused by fluctuations in ambient temperature. Means are provided for periodically firing the gas discharge triode and each time recording the triggering voltage required. A computer compares each triggering voltage with its predecessor. The computer is programmed to energize an alarm if the difference between the two compared voltages is a relatively large value indicative of particulates in the measuring chamber and to disregard smaller differences typically resulting from changes in ambient temperature.

  15. Ionized cluster beam technology for material science

    SciTech Connect (OSTI)

    Takagi, Toshinori

    1997-06-20

    The most suitable kinetic energy range of ionized materials in film formation and epitaxial growth is from a few eV to a few hundreds eV, especially, less than about 100eV, when ions are used as a host. The main roles of ions in film formation are the effects due to their kinetic energy and the electronic charge effects which involve the effect to active film formation and the effect acceleration of chemical reactions. Therefore, it is important to develope the technology to transport large volume of a flux of ionized particles with an extremely low incident energy without any troubles due to the space charge effects and charge up problems on the surface. This is the exact motivation for us to have been developing the Ionized Cluster Beam (ICB) technology since 1972. By ICB technology materials (actually wide varieties of materials such as metal, semiconductor, magnetic material, insulator, organic material, etc.) are vaporized and ejected through a small hole nozzle into a high vacuum, where the vaporized material condenses into clusters with loosely coupled atoms with the sizes about from 100 to a few 1000 atoms (mainly 100-2000 atoms) by supercondensation phenomena due to the adiabatic expansion in this evaporation process through a small hole nozzle. In the ICB technology an atom in each cluster is ionized by irradiated by electron shower, and the ionized clusters are accelerated by electric field onto a substrate. The ionized clusters with neutral clusters impinged onto a substrate are spreaded separately into atoms migrating over the substrate, so that the surface migration energy of the impinged atoms, that is, surface diffusion energy are controlled by an incident energy of a cluster. In this report the theoretical and also experimental results of ICB technology are summarized.

  16. Infrared Radiation Filament And Metnod Of Manufacture

    DOE Patents [OSTI]

    Johnson, Edward A.

    1998-11-17

    An improved IR radiation source is provided by the invention. A radiation filament has a textured surface produced by seeded ion bombardment of a metal foil which is cut to a serpentine shape and mounted in a windowed housing. Specific ion bombardment texturing techniques tune the surface to maximize emissions in the desired wavelength range and to limit emissions outside that narrow range, particularly at longer wavelengths. A combination of filament surface texture, thickness, material, shape and power circuit feedback control produce wavelength controlled and efficient radiation at much lower power requirements than devices of the prior art.

  17. (Basic radiation protection criteria). Final report

    SciTech Connect (OSTI)

    Ney, W.R.

    1982-12-03

    Progress in the following areas directly related to nuclear waste management is summarized: (1) a radiation protection system based on risk per rad of dose; (2) assessment of the accumulation and biological significance of industrial waste discharges and estimation of concentrations present in the environment; (3) assessment of exposure resulting from nuclear power; (4) internal emitter standards; (5) human radiation exposure experience; (6) the identification of national needs related to the estimation of exposure of the public from ionizing radiation; and (7) acceptable risk for management of radioactive waste. (ACR)

  18. Effect of L1{sub 2} ordering in antiferromagnetic Ir-Mn epitaxial layer on exchange bias of FePd films

    SciTech Connect (OSTI)

    Chang, Y. C.; Duh, J. G. E-mail: lin.yg@nsrrc.org.tw; Hsiao, S. N. E-mail: lin.yg@nsrrc.org.tw; Liu, S. H.; Su, S. H.; Chiu, K. F.; Hsieh, W. C.; Chen, S. K.; Lin, Y. G. E-mail: lin.yg@nsrrc.org.tw; Lee, H. Y.; Sung, C. K.

    2015-05-07

    Two series of samples of single-layer IrMn and IrMn/FePd bilayer films, deposited on a single-crystal MgO substrate at different IrMn deposition temperatures (T{sub s} = 300–700 °C), were investigated using magnetron sputtering. L1{sub 2} ordering was revealed for the 30 nm-thick IrMn epitaxial (001) films with T{sub s} ≥ 400 °C, determined by synchrotron radiation x-ray diffractometry (XRD). XRD results also provide evidence of the epitaxial growth of the IrMn films on MgO substrate. Increasing T{sub s} from 400 to 700 °C monotonically increases the ordering parameter of L1{sub 2} phases from 0.17 to 0.81. An in-plane exchange bias field (H{sub eb}) of 22 Oe is obtained in a 10 nm-thick FePd film that is deposited on the disordered IrMn films. As the L1{sub 2} ordering of the IrMn layers increases, the H{sub eb} gradually decreases to 0 Oe, meaning that the exchange bias behavior vanishes. The increased surface roughness, revealed by atomic force microscopy, of the epitaxial IrMn layers with increasing T{sub s} cannot be the main cause of the decrease in H{sub eb} due to the compensated surface spins regardless of the disordered and ordered (001) IrMn layers. The change of antiferromagnetic structure from the A1 to the L1{sub 2} phase was correlated with the evolution of H{sub eb}.

  19. Ionization of cytosine monomer and dimer studied by VUV photoionization and electronic structure calculations

    SciTech Connect (OSTI)

    Kostko, Oleg; Bravaya, Ksenia; Krylov, Anna; Ahmed, Musahid

    2009-12-14

    We report a combined theoretical and experimental study of ionization of cytosine monomers and dimers. Gas-phase molecules are generated by thermal vaporization of cytosine followed by expansion of the vapor in a continuous supersonic jet seeded in Ar. The resulting species are investigated by single photon ionization with tunable vacuum-ultraviolet (VUV) synchrotron radiation and mass analyzed using reflectron mass spectrometry. Energy onsets for the measured photoionization efficiency (PIE) spectra are 8.60+-0.05 eV and 7.6+-0.1 eV for the monomer and the dimer, respectively, and provide an estimate for the adiabatic ionization energies (AIE). The first AIE and the ten lowest vertical ionization energies (VIEs) for selected isomers of cytosine dimer computed using equation-of-motion coupled-cluster (EOM-IP-CCSD) method are reported. The comparison of the computed VIEs with the derivative of the PIE spectra, suggests that multiple isomers of the cytosine dimer are present in the molecular beam. The calculations reveal that the large red shift (0.7 eV) of the first IE of the lowest-energy cytosine dimer is due to strong inter-fragment electrostatic interactions, i.e., the hole localized on one of the fragments is stabilized by the dipole moment of the other. A sharp rise in the CH+ signal at 9.20+-0.05 eV is ascribed to the formation of protonated cytosine by dissociation of the ionized dimers. The dominant role of this channel is supported by the computed energy thresholds for the CH+ appearance and the barrierless or nearly barrierless ionization-induced proton transfer observed for five isomers of the dimer.

  20. Spitzer mid-IR spectroscopy of powerful 2Jy and 3CRR radio galaxies. II. AGN power indicators and unification

    SciTech Connect (OSTI)

    Dicken, D.; Tadhunter, C.; Morganti, R.; Axon, D.; Robinson, A.; Magagnoli, M.; Kharb, P.; Ramos Almeida, C.; Hardcastle, M.; Nesvadba, N. P. H.; Singh, V.; Kouwenhoven, M. B. N.; Rose, M.; Spoon, H.; Inskip, K. J.; Holt, J.

    2014-06-20

    It remains uncertain which continuum and emission line diagnostics best indicate the bolometric powers of active galactic nuclei (AGNs), especially given the attenuation caused by the circumnuclear material and the possible contamination by components related to star formation. Here we use mid-IR spectra along with multiwavelength data to investigate the merit of various diagnostics of AGN radiative power, including the mid-IR [Ne III] ?25.89 ?m and [O IV] ?25.89 ?m fine-structure lines, the optical [O III] ?5007 forbidden line, and mid-IR 24 ?m, 5 GHz radio, and X-ray continuum emission, for complete samples of 46 2Jy radio galaxies (0.05 < z < 0.7) and 17 3CRR FRII radio galaxies (z < 0.1). We find that the mid-IR [O IV] line is the most reliable indicator of AGN power for powerful radio-loud AGNs. By assuming that the [O IV] is emitted isotropically, and comparing the [O III] and 24 ?m luminosities of the broad- and narrow-line AGNs in our samples at fixed [O IV] luminosity, we show that the [O III] and 24 ?m emission are both mildly attenuated in the narrow-line compared to the broad-line objects by a factor of ?2. However, despite this attenuation, the [O III] and 24 ?m luminosities are better AGN power indicators for our sample than either the 5 GHz radio or the X-ray continuum luminosities. We also detect the mid-IR 9.7 ?m silicate feature in the spectra of many objects but not ubiquitously: at least 40% of the sample shows no clear evidence for these features. We conclude that, for the majority of powerful radio galaxies, the mid-IR lines are powered by AGN photoionization.

  1. Method and apparatus for generating radiation utilizing DC to AC conversion with a conductive front

    DOE Patents [OSTI]

    Dawson, J.M.; Mori, W.B.; Lai, C.H.; Katsouleas, T.C.

    1998-07-14

    Method and apparatus ar disclosed for generating radiation of high power, variable duration and broad tunability over several orders of magnitude from a laser-ionized gas-filled capacitor array. The method and apparatus convert a DC electric field pattern into a coherent electromagnetic wave train when a relativistic ionization front passes between the capacitor plates. The frequency and duration of the radiation is controlled by the gas pressure and capacitor spacing. 4 figs.

  2. Method and apparatus for generating radiation utilizing DC to AC conversion with a conductive front

    DOE Patents [OSTI]

    Dawson, John M.; Mori, Warren B.; Lai, Chih-Hsiang; Katsouleas, Thomas C.

    1998-01-01

    Method and apparatus for generating radiation of high power, variable duration and broad tunability over several orders of magnitude from a laser-ionized gas-filled capacitor array. The method and apparatus convert a DC electric field pattern into a coherent electromagnetic wave train when a relativistic ionization front passes between the capacitor plates. The frequency and duration of the radiation is controlled by the gas pressure and capacitor spacing.

  3. WARPED IONIZED HYDROGEN IN THE GALAXY

    SciTech Connect (OSTI)

    Cersosimo, J. C.; Figueroa, N. Santiago; Velez, S. Figueroa; Soto, C. Lozada; Mader, S.; Azcarate, D.

    2009-07-01

    We report observations of the H166{alpha} ({nu} = 1424.734 MHz) radio recombination line (RRL) emission from the Galactic plane in the longitude range l = 267 deg. - 302 deg. and latitude range b = -3.{sup 0}0 to +1.{sup 0}5. The line emission observed describes the Carina arm in the Galactic azimuth range from {theta} = 260 deg. to 190 deg. The structure is located at negative latitudes with respect to the formal Galactic plane. The observations are combined with RRL data from the first Galactic quadrant. Both quadrants show the signature of the warp for the ionized gas, but an asymmetry of the distribution is noted. In the fourth quadrant, the gas is located between Galactic radii R {approx} 7 and 10 kpc, and the amplitude of the warp is seen from the midplane to z {approx} -150 pc. In the first quadrant, the gas is found between R {approx} 8 and 13-16 kpc, and flares to z {approx} +350 pc. We confirm the warp of the ionized gas near the solar circle. The distribution of the ionized gas is compared with the maximum intensity H I emission (0.30 < n{sub HI} < 0.45 cm{sup -3}) at intervals of the Galactic ring. The ionized material is correlated with the H I maximum intensity in both quadrants, and both components show the same tilted behavior with respect to the mid-Galactic plane.

  4. Theory of multiphoton ionization of atoms

    SciTech Connect (OSTI)

    Szoeke, A.

    1986-03-01

    A non-perturbative approach to the theory of multiphoton ionization is reviewed. Adiabatic Floquet theory is its first approximation. It explains qualitatively the energy and angular distribution of photoelectrons. In many-electron atoms it predicts collective and inner shell excitation. 14 refs.

  5. Danger radiations

    ScienceCinema (OSTI)

    None

    2011-04-25

    Le conférencier Mons.Hofert parle des dangers et risques des radiations, le contrôle des zones et les précautions à prendre ( p.ex. film badge), comment mesurer les radiations etc.

  6. The MICE Demonstration of Ionization Cooling

    SciTech Connect (OSTI)

    Pasternak, J.; Blackmore, V.; Hunt, C.; Lagrange, J-B.; Long, K.; Collomb, N.; Snopok, P.

    2015-05-01

    Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams necessary to elucidate the physics of flavour at the Neutrino Factory and to provide lepton-antilepton collisions at energies of up to several TeV at the Muon Collider. The International Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization cooling channel, the muon beam passes through a material (the absorber) in which it loses energy. The energy lost is then replaced using RF cavities. The combined effect of energy loss and re-acceleration is to reduce the transverse emittance of the beam (transverse cooling). A major revision of the scope of the project was carried out over the summer of 2014. The revised project plan, which has received the formal endorsement of the international MICE Project Board and the international MICE Funding Agency Committee, will deliver a demonstration of ionization cooling by September 2017. In the revised configuration a central lithium-hydride absorber provides the cooling effect. The magnetic lattice is provided by the two superconducting focus coils and acceleration is provided by two 201 MHz single-cavity modules. The phase space of the muons entering and leaving the cooling cell will be measured by two solenoidal spectrometers. All the superconducting magnets for the ionization cooling demonstration are available at the Rutherford Appleton Laboratory and the first single-cavity prototype is under test in the MuCool Test Area at Fermilab. The design of the cooling demonstration experiment will be described together with a summary of the performance of each of its components. The cooling performance of the revised configuration will also be presented.

  7. New IRS Rules for Small and Medium Wind Turbines

    Broader source: Energy.gov [DOE]

    The Small Wind Certification Council (SWCC) will host a webinar on how certification is being used to meet the new Internal Revenue Service (IRS) requirements for small and medium wind turbines...

  8. DWEA Webinar: IRS Guidance for Small Wind Turbines

    Broader source: Energy.gov [DOE]

    The U.S. Internal Revenue Service (IRS) has issued Notice 2015-4 providing new performance and quality standards of small wind turbines – defined as having a nameplate capacity of up to 100 kW – in...

  9. IRS Announces New Tribal Economic Development Bond Allocation Guidance

    Broader source: Energy.gov [DOE]

    Treasury and the IRS published new guidance today allocating Tribal Economic Development Bonds (TEDBs) for Tribes that have projects that are in the final stages of going to the market to receive financing.

  10. ARM - Field Campaign - IR Cloud Camera Feasibility Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    govCampaignsIR Cloud Camera Feasibility Study ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send...