WorldWideScience

Sample records for radiation grazing-incidence optics

  1. Grazing Incidence Optics Technology

    Science.gov (United States)

    Ramsey, Brian; Smith, W. Scott; Gubarev, Mikhail; McCracken, Jeff

    2015-01-01

    This project is to demonstrate the capability to directly fabricate lightweight, high-resolution, grazing-incidence x-ray optics using a commercially available robotic polishing machine. Typical x-ray optics production at NASA Marshall Space Flight Center (MSFC) uses a replication process in which metal mirrors are electroformed on to figured and polished mandrels from which they are later removed. The attraction of this process is that multiple copies can be made from a single master. The drawback is that the replication process limits the angular resolution that can be attained. By directly fabricating each shell, errors inherent in the replication process are removed. The principal challenge now becomes how to support the mirror shell during all aspects of fabrication, including the necessary metrology to converge on the required mirror performance specifications. This program makes use of a Zeeko seven-axis computer-controlled polishing machine (see fig. 1) and supporting fabrication, metrology, and test equipment at MSFC. The overall development plan calls for proof-of-concept demonstration with relatively thick mirror shells (5-6 mm, fig. 2) which are straightforward to support and then a transition to much thinner shells (2-3 mm), which are an order of magnitude thinner than those used for Chandra. Both glass and metal substrates are being investigated. Currently, a thick glass shell is being figured. This has enabled experience to be gained with programming and operating the polishing machine without worrying about shell distortions or breakage. It has also allowed time for more complex support mechanisms for figuring/ polishing and metrology to be designed for the more challenging thinner shells. These are now in fabrication. Figure 1: Zeeko polishing machine.

  2. Grazing Incidence Neutron Optics

    Science.gov (United States)

    Gubarev, Mikhail V. (Inventor); Ramsey, Brian D. (Inventor); Engelhaupt, Darell E. (Inventor)

    2013-01-01

    Neutron optics based on the two-reflection geometries are capable of controlling beams of long wavelength neutrons with low angular divergence. The preferred mirror fabrication technique is a replication process with electroform nickel replication process being preferable. In the preliminary demonstration test an electroform nickel optics gave the neutron current density gain at the focal spot of the mirror at least 8 for neutron wavelengths in the range from 6 to 20.ANG.. The replication techniques can be also be used to fabricate neutron beam controlling guides.

  3. The current status of grazing incidence optics

    International Nuclear Information System (INIS)

    Aschenbach, B.

    1983-01-01

    The developments in the area of grazing incidence optics with emphasis on telescopes for use in X-ray astronomy are reviewed. The performance of existing high-resolution telescopes is outlined and compared with those expected from future missions like ROSAT and AXAF. Starting from the basic principles of X-ray reflection and scattering, an attempt is made to highlight the current understanding of X-ray mirror physics using new theoretical ideas as well as experimental laboratory results. (author)

  4. Grazing incidence optics; Proceedings of the Meeting, Orlando, FL, Apr. 3, 4, 1986

    Science.gov (United States)

    Osantowski, John F. (Editor); Van Speybroeck, Leon (Editor)

    1986-01-01

    Papers are presented on the diffraction-limited performance of grazing incidence optical systems; transverse ray aberrations of Wolter type 1 telescopes; hybrid X-ray telescope systems; surface characterization of grazing incidence optics in the extreme UV and X-ray regions; and the surface roughness properties of synchrotron radiation optics. Topics discussed include the simulation of free-abrasive grinding of grazing incidence mirrors with vertical-honing and flexible blades; mirrors for the Extreme Ultraviolet Explorer; the design and development of conical X-ray imaging mirrors; thermal loading considerations for synchrotron radiation mirrors; and grazing incidence optics for synchrotron radiation insertion-device beams. Consideration is given to the interpretation of glancing incidence scattering measurements; damage processes in short wavelength coated FEL optics; the replication of grain incidence optics; and the assembly and alignment of the Technology Mirror Assembly.

  5. Active Micro structured Optical Arrays of Grazing Incidence Reflectors

    International Nuclear Information System (INIS)

    Willingale, R.; Feldman, Ch.; Michette, A.; Hart, D.; McFaul, Ch; Morrison, G.R.; Pfauntsch, S.; Powell, A.K.; Sahraei, Sh.; Shand, M.T.; Button, T.; Rodriguez-Sanmartin, D.; Zhang, D.; Dunare, C.; Parkes, W.; Stevenson, T.; Folkard, M.; Vojnovic, B.; Vojnovic, B.

    2011-01-01

    The UK Smart X-Ray Optics (SXO) programme is developing active/adaptive optics for terrestrial applications. One of the technologies proposed is micro structured optical arrays (MOAs), which focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels. Although such arrays are similar in concept to poly capillary and microchannel plate optics, they can be bent and adjusted using piezoelectric actuators providing control over the focusing and inherent aberrations. Custom configurations can be designed, using ray tracing and finite element analysis, for applications from sub-keV to several-keV X-rays, and the channels of appropriate aspect ratios can be made using deep silicon etching. An exemplar application will be in the micro probing of biological cells and tissue samples using Ti Ka radiation (4.5?keV) in studies related to radiation-induced cancers. This paper discusses the optical design, modelling, and manufacture of such optics

  6. Aplanatic grazing incidence diffraction grating: a new optical element

    International Nuclear Information System (INIS)

    Hettrick, M.C.

    1986-01-01

    We present the theory of a grazing incidence reflection grating capable of imaging at submicron resolution. The optic is mechanically ruled on a spherical or cylindrical surface with varied groove spacings, delivering diffraction-limited response and a wide field of view at a selected wavelength. Geometrical aberrations are calculated on the basis of Fermat's principle, revealing significant improvements over a grazing incidence mirror. Aplanatic and quasi-aplanatic versions of the grating have applications in both imaging and scanning microscopes, microprobes, collimators, and telescopes. A 2-D crossed system of such gratings, similar to the grazing incidence mirror geometry of Kirkpatrick and Baez, could potentially provide spatial resolutions of --200 A

  7. Active Full-Shell Grazing-Incidence Optics

    Science.gov (United States)

    Davis, Jacqueline M.; Elsner, Ronald F.; Ramsey, Brian D.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Gubarev, Mikhail V.

    2016-01-01

    MSFC has a long history of developing full-shell grazing-incidence x-ray optics for both narrow (pointed) and wide field (surveying) applications. The concept presented in this paper shows the potential to use active optics to switch between narrow and wide-field geometries, while maintaining large effective area and high angular resolution. In addition, active optics has the potential to reduce errors due to mounting and manufacturing lightweight optics. The design presented corrects low spatial frequency error and has significantly fewer actuators than other concepts presented thus far in the field of active x-ray optics. Using a finite element model, influence functions are calculated using active components on a full-shell grazing-incidence optic. Next, the ability of the active optic to effect a change of optical prescription and to correct for errors due to manufacturing and mounting is modeled.

  8. Adjustable Grazing-Incidence X-Ray Optics

    Science.gov (United States)

    O'Dell, Stephen L.; Reid, Paul B.

    2015-01-01

    With its unique subarcsecond imaging performance, NASA's Chandra X-ray Observatory illustrates the importance of fine angular resolution for x-ray astronomy. Indeed, the future of x-ray astronomy relies upon x-ray telescopes with comparable angular resolution but larger aperture areas. Combined with the special requirements of nested grazing-incidence optics, mass, and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. The goal of this technology research is to enable the cost-effective fabrication of large-area, lightweight grazing-incidence x-ray optics with subarcsecond resolution. Toward this end, the project is developing active x-ray optics using slumped-glass mirrors with thin-film piezoelectric arrays for correction of intrinsic or mount-induced distortions.

  9. An Evaluation of Grazing-Incidence Optics for Neutron Imaging

    Science.gov (United States)

    Gubarev, M. V.

    2007-01-01

    The refractive index for most materials is slightly less than unity, which opens an opportunity to develop the grazing incidence neutron imaging optics. The ideal material for the optics would be natural nickel and its isotopes. Marshall Space Flight Center (MSFC) has active development program on the nickel replicated optics for use in x-ray astronomy. Brief status report on the program is presented. The results of the neutron focusing optic test carried by the MSFC team at National Institute of Standards and Technology (NIST) are also presented. Possible applications of the optics are briefly discussed.

  10. Optical design of grazing incidence toroidal grating monochromator

    International Nuclear Information System (INIS)

    Pouey, M.; Howells, M.R.; Takacs, P.Z.

    1982-01-01

    Design rules using geometrical optics and physical optics associated with the phase balancing method are discussed for stigmatic toroidal grazing incidence monochromators. To determine the optical performance of devices involving mirrirs and/or gratings, ray tracing programs using exact geometry are quite widely used. It is then desirable to have some way to infer the practical performance of an instrument from a spot diagram created by tracing a limited number of rays. We propose a first approach to this problem involving an estimation of the geometrical intensity distribution in the image plane and the corresponding line spread function. (orig.)

  11. Partially coherent X-ray wavefront propagation simulations including grazing-incidence focusing optics.

    Science.gov (United States)

    Canestrari, Niccolo; Chubar, Oleg; Reininger, Ruben

    2014-09-01

    X-ray beamlines in modern synchrotron radiation sources make extensive use of grazing-incidence reflective optics, in particular Kirkpatrick-Baez elliptical mirror systems. These systems can focus the incoming X-rays down to nanometer-scale spot sizes while maintaining relatively large acceptance apertures and high flux in the focused radiation spots. In low-emittance storage rings and in free-electron lasers such systems are used with partially or even nearly fully coherent X-ray beams and often target diffraction-limited resolution. Therefore, their accurate simulation and modeling has to be performed within the framework of wave optics. Here the implementation and benchmarking of a wave-optics method for the simulation of grazing-incidence mirrors based on the local stationary-phase approximation or, in other words, the local propagation of the radiation electric field along geometrical rays, is described. The proposed method is CPU-efficient and fully compatible with the numerical methods of Fourier optics. It has been implemented in the Synchrotron Radiation Workshop (SRW) computer code and extensively tested against the geometrical ray-tracing code SHADOW. The test simulations have been performed for cases without and with diffraction at mirror apertures, including cases where the grazing-incidence mirrors can be hardly approximated by ideal lenses. Good agreement between the SRW and SHADOW simulation results is observed in the cases without diffraction. The differences between the simulation results obtained by the two codes in diffraction-dominated cases for illumination with fully or partially coherent radiation are analyzed and interpreted. The application of the new method for the simulation of wavefront propagation through a high-resolution X-ray microspectroscopy beamline at the National Synchrotron Light Source II (Brookhaven National Laboratory, USA) is demonstrated.

  12. The Development of a Differential Deposition Technique for Figure Correction in Grazing Incidence Optics

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the development of a physical-vapor-deposition coating technique to correct residual figure errors in grazing-incidence optics. The process involves...

  13. Mirror and grating surface figure requirements for grazing incidence synchrotron radiation beamlines: Power loading effects

    Energy Technology Data Exchange (ETDEWEB)

    Hulbert, S.L.; Sharma, S.

    1987-01-01

    At present, grazing incidence mirrors are used almost exclusively as the first optical element in VUV and soft x-ray synchrotron radiation beamlines. The performance of these mirrors is determined by thermal and mechanical stress-induced figure errors as well as by figure errors remaining from the grinding and polishing process. With the advent of VUV and soft x-ray undulators and wigglers has come a new set of thermal stress problems related to both the magnitude and the spatial distribution of power from these devices. In many cases the power load on the entrance slits and gratings in these beamlines is no longer negligible. The dependence of thermally-induced front-end mirror figure errors on various storage ring and insertion device parameters (especially those at the National Synchrotron Light Source) and the effects of these figure errors on two classes of soft x-ray beamlines are presented.

  14. Mark IV 'Grasshopper' grazing incidence mono-chromator for the Canadian Synchrotron Radiation Facility (CSRF)

    International Nuclear Information System (INIS)

    Tan, K.H.; Bancroft, G.M.; Coatsworth, L.L.; Yates, B.W.

    1982-01-01

    The vacuum, mechanical, and optical characteristics of a 'Grasshopper' grazing incidence monochromator for use with a synchrotron radiation source in the 30-300 eV range is described. The monochromator is compatible with ultrahigh vacuum ( -10 Torr throughout), and the motor driven scan mechanism is linear and reliable. The monchromator has been calibrated using several known absorption edges between 36 and 102 eV and a nonlinear least squares fit to the scan equation. These same absorption edges, plus a scan over zero order, show that the present resolution of the monochromator (with 10 and 16 μm exit and entrance slits respectively) is 0.16 A (0.06 eV at the AlLsub(2,3) edge). With 10 μm entrance and exit slits the resolution will be very close to the theoretical Δlambda = 0.083 A

  15. Experiment and application of soft x-ray grazing incidence optical scattering phenomena

    Science.gov (United States)

    Chen, Shuyan; Li, Cheng; Zhang, Yang; Su, Liping; Geng, Tao; Li, Kun

    2017-08-01

    For short wavelength imaging systems,surface scattering effects is one of important factors degrading imaging performance. Study of non-intuitive surface scatter effects resulting from practical optical fabrication tolerances is a necessary work for optical performance evaluation of high resolution short wavelength imaging systems. In this paper, Soft X-ray optical scattering distribution is measured by a soft X-ray reflectometer installed by my lab, for different sample mirrors、wavelength and grazing angle. Then aim at space solar telescope, combining these scattered light distributions, and surface scattering numerical model of grazing incidence imaging system, PSF and encircled energy of optical system of space solar telescope are computed. We can conclude that surface scattering severely degrade imaging performance of grazing incidence systems through analysis and computation.

  16. The role of surface topography in predicting scattering at grazing incidence from optical surfaces

    International Nuclear Information System (INIS)

    Rehn, V.; Jones, V.O.; Elson, J.M.; Bennett, J.M.

    1980-01-01

    Monochromator design and the design of optical experiments at XUV and X-ray wavelengths are frequently limited by scattering from optical components, yet theoretical treatments are few and untested experimentally. This is partly due to the failure of scattering models used in the visible and near UV when the wavelength becomes comparable to, or smaller than, the topographic features on the surface, and partly it is due to the difficulty in measuring the topography on the required size scale. We briefly review the theoretical problems and prospects for accurately predicting both the magnitude and angular distribution of scattering at grazing incidence from optical surfaces. Experimental methods for determining and representing the surface topography are also reviewed, together with their limitations and ranges of applicability. Finally, the first results of our experiments, conducted recently at the Stanford Synchrotron Radiation Laboratory on the angular distribution of scattering by surfaces of known topography are presented and discussed, along with their potential implications for the theory of scattering, and for XUV and X-ray optical components. (orig.)

  17. X-ray microscopy using grazing-incidence reflections optics

    International Nuclear Information System (INIS)

    Price, R.H.

    1983-01-01

    The role of Kirkpatrick-Baez microscopes as the workhorse of the x-ray imaging devices is discussed. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics

  18. X-ray microscopy using grazing-incidence reflection optics

    International Nuclear Information System (INIS)

    Price, R.H.

    1981-01-01

    The Kirkpatrick-Baez microscopes are described along with their role as the workhorse of the x-ray imaging devices. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics

  19. Development of highly polished, grazing incidence mirrors for synchrotron radiation beam lines at SSRL

    Energy Technology Data Exchange (ETDEWEB)

    Tirsell, K.G.; Berglin, E.J.; Fuchs, B.A.; Holdener, F.R.; Humpal, H.H.; Karpenko, V.P.; Kulkarni, S.; Fantone, S.D.

    1987-08-01

    New platinum-coated grazing incidence mirrors with low surface roughnesses have been developed to focus bending magnet radiation from the SSRL/SLAC SPEAR storage ring on the entrance slits of two Beam Line VIII grating monochromators. The first mirror in the toroidal grating monochromator (TGM) branch is a cooled SiC cylinder capable of absorbing synchrotron radiation power levels of up to 260 watts without excessive distortion. This mirror deflects the beam vertically through a 12/degree/ angle and focuses it sagitally on the TGM entrance slit plane. The second TGM optical element is a fused-silica spherical mirror with a large radius of curvature that deflects the beam vertically through an additional 12/degree/ and focuses it tangentially with 3/1 demagnification. The first mirror in our spherical grating branch is a 5/degree/-vertically deflecting, cooled SiC toroid designed to focus tangentially on the monochromator entrance slits and sagitally in the exit slits. A 4/degree/-deflecting fused silica mirror is used after the exit sites in each beam line to refocus on to the sample. For this application a thin cylinder is bent to approximate an ellipsoid. The mirrors are now installed at SSRL and performance measurements are planned. Qualitatively the focus of the TGM optics at the entrance slit plane appears very good. In this paper we discuss considerations leading to the choice of SiC for each of the two first mirrors. We present highlights of the development of these mirrors with some emphasis on SiC polishing techniques. In addition, the specialized metrology developed to produce the more difficult figure of the toroid will be described. Measured surface roughness and figure results will be presented. 19 refs., 11 figs.

  20. Development of highly polished, grazing incidence mirrors for synchrotron radiation beam lines at SSRL

    International Nuclear Information System (INIS)

    Tirsell, K.G.; Berglin, E.J.; Fuchs, B.A.; Holdener, F.R.; Humpal, H.H.; Karpenko, V.P.; Kulkarni, S.; Fantone, S.D.

    1987-08-01

    New platinum-coated grazing incidence mirrors with low surface roughnesses have been developed to focus bending magnet radiation from the SSRL/SLAC SPEAR storage ring on the entrance slits of two Beam Line VIII grating monochromators. The first mirror in the toroidal grating monochromator (TGM) branch is a cooled SiC cylinder capable of absorbing synchrotron radiation power levels of up to 260 watts without excessive distortion. This mirror deflects the beam vertically through a 12/degree/ angle and focuses it sagitally on the TGM entrance slit plane. The second TGM optical element is a fused-silica spherical mirror with a large radius of curvature that deflects the beam vertically through an additional 12/degree/ and focuses it tangentially with 3/1 demagnification. The first mirror in our spherical grating branch is a 5/degree/-vertically deflecting, cooled SiC toroid designed to focus tangentially on the monochromator entrance slits and sagitally in the exit slits. A 4/degree/-deflecting fused silica mirror is used after the exit sites in each beam line to refocus on to the sample. For this application a thin cylinder is bent to approximate an ellipsoid. The mirrors are now installed at SSRL and performance measurements are planned. Qualitatively the focus of the TGM optics at the entrance slit plane appears very good. In this paper we discuss considerations leading to the choice of SiC for each of the two first mirrors. We present highlights of the development of these mirrors with some emphasis on SiC polishing techniques. In addition, the specialized metrology developed to produce the more difficult figure of the toroid will be described. Measured surface roughness and figure results will be presented. 19 refs., 11 figs

  1. Differential Deposition for Surface Figure Corrections in Grazing Incidence X-Ray Optics

    Science.gov (United States)

    Ramsey, Brian D.; Kilaru, Kiranmayee; Atkins, Carolyn; Gubarev, Mikhail V.; Broadway, David M.

    2015-01-01

    Differential deposition corrects the low- and mid- spatial-frequency deviations in the axial figure of Wolter-type grazing incidence X-ray optics. Figure deviations is one of the major contributors to the achievable angular resolution. Minimizing figure errors can significantly improve the imaging quality of X-ray optics. Material of varying thickness is selectively deposited, using DC magnetron sputtering, along the length of optic to minimize figure deviations. Custom vacuum chambers are built that can incorporate full-shell and segmented Xray optics. Metrology data of preliminary corrections on a single meridian of full-shell x-ray optics show an improvement of mid-spatial frequencies from 6.7 to 1.8 arc secs HPD. Efforts are in progress to correct a full-shell and segmented optics and to verify angular-resolution improvement with X-ray testing.

  2. Adaptive grazing incidence optics for the next generation of x-ray observatories

    Science.gov (United States)

    Lillie, C.; Pearson, D.; Plinta, A.; Metro, B.; Lintz, E.; Shropshire, D.; Danner, R.

    2010-09-01

    Advances in X-ray astronomy require high spatial resolution and large collecting area. Unfortunately, X-ray telescopes with grazing incidence mirrors require hundreds of concentric mirror pairs to obtain the necessary collecting area, and these mirrors must be thin shells packed tightly together... They must also be light enough to be placed in orbit with existing launch vehicles, and able to be fabricated by the thousands for an affordable cost. The current state of the art in X-ray observatories is represented by NASA's Chandra X-ray observatory with 0.5 arc-second resolution, but only 400 cm2 of collecting area, and by ESA's XMM-Newton observatory with 4,300 cm2 of collecting area but only 15 arc-second resolution. The joint NASA/ESA/JAXA International X-ray Observatory (IXO), with {15,000 cm2 of collecting area and 5 arc-second resolution which is currently in the early study phase, is pushing the limits of passive mirror technology. The Generation-X mission is one of the Advanced Strategic Mission Concepts that NASA is considering for development in the post-2020 period. As currently conceived, Gen-X would be a follow-on to IXO with a collecting area >= 50 m2, a 60-m focal length and 0.1 arc-second spatial resolution. Gen-X would be launched in {2030 with a heavy lift Launch Vehicle to an L2 orbit. Active figure control will be necessary to meet the challenging requirements of the Gen-X optics. In this paper we present our adaptive grazing incidence mirror design and the results from laboratory tests of a prototype mirror.

  3. X-ray radiation damage of organic semiconductor thin films during grazing incidence diffraction experiments

    Energy Technology Data Exchange (ETDEWEB)

    Neuhold, A., E-mail: alfred.neuhold@tugraz.at [Institute of Solid State Physics, Graz University of Technology, Graz (Austria); Novak, J.; Flesch, H.-G.; Moser, A.; Djuric, T. [Institute of Solid State Physics, Graz University of Technology, Graz (Austria); Grodd, L.; Grigorian, S.; Pietsch, U. [Institute of Physics, University Siegen (Germany); Resel, R. [Institute of Solid State Physics, Graz University of Technology, Graz (Austria)

    2012-08-01

    Since modern synchrotrons with highly intense X-ray beams are in use to investigate organic materials, the stability of soft matter materials during beam exposure is a crucial issue. Grazing incidence X-ray diffraction and specular X-ray reflectivity measurements were performed on thin films of organic semiconducting materials, like poly(3-hexylthiophene) (P3HT), sexithiophene and pentacene. These films were irradiated with an average flux density between 10{sup 15} and 10{sup 16} photons/(s mm{sup 2}) and evidenced a different stability in synchrotron X-ray radiation. The semi-crystalline P3HT showed a clear intensity decrease of the 1 0 0 Bragg peak and 0 2 0 Bragg peak compared to the rather stable diffraction features of the molecular crystals sexithiophene and pentacene. The difference in synchrotron X-ray radiation stability is explained by the interaction of the X-ray beam with the individual chemical components in the molecules as well as by the different crystallinities of the materials. Furthermore, the semi-crystalline P3HT film exhibited an increase of film thickness after irradiation and the surface roughness slightly decreased. To summarize, this study shows a strong influence of synchrotron X-ray radiation to specific organic thin films like e.g. P3HT, while others like pentacene and sexithiophene are observed as quite stable.

  4. Adjustable Grazing Incidence X-ray Optics with 0.5 Arc Second Resolution

    Science.gov (United States)

    Reid, Paul

    We seek to develop adjustable grazing incidence optics for x-ray astronomy. The goal of this development is thin, lightweight mirrors with angular resolution of 0.5 arc seconds, comparable to the Chandra X-ray Observatory. The new mirror design consists of thin segments of a Wolter-I grazing incidence mirror, with piezo-electric material deposited directly on the back surface of the mirror. Depositing a pattern of independently addressable electrodes on top of the piezoelectric material produces an array of independent piezo cells. Energizing a particular cell introduces a localized deformation in the mirror without the need for a reaction structure. By applying the appropriate voltage to the piezo cells, it is possible to correct mirror figure errors that result from mirror fabrication, gravity release, mounting, and thermal effects. Because the thin mirrors segments are lightweight, they can be densely nested to produce collecting area thirty times that of Chandra, on an affordably priced mission. This Supporting Technology program is a follow-on to an existing APRA program. In the existing program we demonstrated the first successful deposition of piezoelectric material on thermally formed glass substrates. We showed that the localized deformations produced by the piezo cells match finite element predictions, and the piezo cell adjustment range meets requirements necessary to achieve the desired figure correction. We have also shown through simulation that representative mirror figure errors can be corrected via modeled influence functions to achieve 0.5 arc sec imaging performance. This provides a firm foundation on which to develop further the technology. We will continue to optimize the deposition of thin piezoelectric films onto thermally formed glass and electroplated metal mirror segments to improve yield and manufacturability. We will deposit piezoelectric material onto conical mirror segments and demonstrate figure correction in agreement with prediction

  5. Mounting for Fabrication, Metrology, and Assembly of Full Shell Grazing Incidence Optics

    Science.gov (United States)

    Roche, Jacqueline M.; Gubarev, Mikhail V.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Ramsey, Brian D.; Elsner, Ronald F.

    2014-01-01

    Future x-ray telescopes will likely require lightweight mirrors to attain the large collecting areas needed to accomplish the science objectives. Understanding and demonstrating processes now is critical to achieving sub-arcsecond performance in the future. Consequently, designs not only of the mirrors but of fixtures for supporting them during fabrication, metrology, handling, assembly, and testing must be adequately modeled and verified. To this end, MSFC is using finite-element modeling to study the effects of mounting on full-shell grazing-incidence mirrors, during all processes leading to flight mirror assemblies. Here we report initial results of this study.

  6. Optical Analysis of Grazing Incidence Ring Resonators for Free-Electron Lasers

    Science.gov (United States)

    Gabardi, David Richard

    1990-08-01

    The design of resonators for free-electron lasers (FELs) which are to operate in the soft x-ray/vacuum ultraviolet (XUV) region of the spectrum is complicated by the fact that, in this wavelength regime, normal incidence mirrors, which would otherwise be used for the construction of the resonators, generally have insufficient reflectivities for this purpose. However, the use of grazing incidence mirrors in XUV resonators offers the possibility of (1) providing sufficient reflectivity, (2) a lessening of the mirrors' thermal loads due to the projection of the laser beam onto an oblique surface, and (3) the preservation of the FEL's tunability. In this work, the behavior of resonators employing grazing incidence mirrors in ring type configurations is explored. In particular, two designs, each utilizing four off-axis conic mirrors and a number of flats, are examined. In order to specify the location, orientation, and surface parameters for the mirrors in these resonators, a design algorithm has been developed based upon the properties of Gaussian beam propagation. Two computer simulation methods are used to perform a vacuum stability analysis of the two resonator designs. The first method uses paraxial ray trace techniques with the resonators' thin lens analogues while the second uses the diffraction-based computer simulation code GLAD (General Laser Analysis and Design). The effects of mirror tilts and deviations in the mirror surface parameters are investigated for a number of resonators designed to propagate laser beams of various Rayleigh ranges. It will be shown that resonator stability decreases as the laser wavelength for which the resonator was designed is made smaller. In addition, resonator stability will also be seen to decrease as the amount of magnification the laser beam receives as it travels around the resonator is increased.

  7. Computer-Controlled Cylindrical Polishing Process for Development of Grazing Incidence Optics for Hard X-Ray Region

    Science.gov (United States)

    Khan, Gufran Sayeed; Gubarev, Mikhail; Speegle, Chet; Ramsey, Brian

    2010-01-01

    The presentation includes grazing incidence X-ray optics, motivation and challenges, mid spatial frequency generation in cylindrical polishing, design considerations for polishing lap, simulation studies and experimental results, future scope, and summary. Topics include current status of replication optics technology, cylindrical polishing process using large size polishing lap, non-conformance of polishin lap to the optics, development of software and polishing machine, deterministic prediction of polishing, polishing experiment under optimum conditions, and polishing experiment based on known error profile. Future plans include determination of non-uniformity in the polishing lap compliance, development of a polishing sequence based on a known error profile of the specimen, software for generating a mandrel polishing sequence, design an development of a flexible polishing lap, and computer controlled localized polishing process.

  8. Grazing incidence beam expander

    Energy Technology Data Exchange (ETDEWEB)

    Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

    1985-01-01

    A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

  9. Grazing Incidence Wavefront Sensing and Verification of X-Ray Optics Performance

    Science.gov (United States)

    Saha, Timo T.; Rohrbach, Scott; Zhang, William W.

    2011-01-01

    Evaluation of interferometrically measured mirror metrology data and characterization of a telescope wavefront can be powerful tools in understanding of image characteristics of an x-ray optical system. In the development of soft x-ray telescope for the International X-Ray Observatory (IXO), we have developed new approaches to support the telescope development process. Interferometrically measuring the optical components over all relevant spatial frequencies can be used to evaluate and predict the performance of an x-ray telescope. Typically, the mirrors are measured using a mount that minimizes the mount and gravity induced errors. In the assembly and mounting process the shape of the mirror segments can dramatically change. We have developed wavefront sensing techniques suitable for the x-ray optical components to aid us in the characterization and evaluation of these changes. Hartmann sensing of a telescope and its components is a simple method that can be used to evaluate low order mirror surface errors and alignment errors. Phase retrieval techniques can also be used to assess and estimate the low order axial errors of the primary and secondary mirror segments. In this paper we describe the mathematical foundation of our Hartmann and phase retrieval sensing techniques. We show how these techniques can be used in the evaluation and performance prediction process of x-ray telescopes.

  10. Figure and finish of grazing incidence mirrors

    International Nuclear Information System (INIS)

    Takacs, P.Z.; Church, E.L.

    1989-08-01

    Great improvement has been made in the past several years in the quality of optical components used in synchrotron radiation (SR) beamlines. Most of this progress has been the result of vastly improved metrology techniques and instrumentation permitting rapid and accurate measurement of the surface finish and figure on grazing incidence optics. A significant theoretical effort has linked the actual performance of components used as x-ray wavelengths to their topological properties as measured by surface profiling instruments. Next-generation advanced light sources will require optical components and systems to have sub-arc second surface figure tolerances. This paper will explore the consequences of these requirements in terms of manufacturing tolerances to see if the present manufacturing state-of-the-art is capable of producing the required surfaces. 15 refs., 14 figs., 2 tabs

  11. Aplanatic telescopes based on Schwarzschild optical configuration: from grazing incidence Wolter-like x-ray optics to Cherenkov two-mirror normal incidence telescopes

    Science.gov (United States)

    Sironi, Giorgia

    2017-09-01

    At the beginning of XX century Karl Schwarzschild defined a method to design large-field aplanatic telescopes based on the use of two aspheric mirrors. The approach was then refined by Couder (1926) who, in order to correct for the astigmatic aberration, introduced a curvature of the focal plane. By the way, the realization of normal-incidence telescopes implementing the Schwarzschild aplanatic configuration has been historically limited by the lack of technological solutions to manufacture and test aspheric mirrors. On the other hand, the Schwarzschild solution was recovered for the realization of coma-free X-ray grazing incidence optics. Wolter-like grazing incidence systems are indeed free of spherical aberration, but still suffer from coma and higher order aberrations degrading the imaging capability for off-axis sources. The application of the Schwarzschild's solution to X-ray optics allowed Wolter to define an optical system that exactly obeys the Abbe sine condition, eliminating coma completely. Therefore these systems are named Wolter-Schwarzschild telescopes and have been used to implement wide-field X-ray telescopes like the ROSAT WFC and the SOHO X-ray telescope. Starting from this approach, a new class of X-ray optical system was proposed by Burrows, Burg and Giacconi assuming polynomials numerically optimized to get a flat field of view response and applied by Conconi to the wide field x-ray telescope (WFXT) design. The Schwarzschild-Couder solution has been recently re-discovered for the application to normal-incidence Cherenkov telescopes, thanks to the suggestion by Vassiliev and collaborators. The Italian Institute for Astrophysics (INAF) realized the first Cherenkov telescope based on the polynomial variation of the Schwarzschild configuration (the so-called ASTRI telescope). Its optical qualification was successfully completed in 2016, demonstrating the suitability of the Schwarzschild-like configuration for the Cherenkov astronomy requirements

  12. Stress measurements by multi-reflection grazing-incidence X-ray diffraction method (MGIXD) using different radiation wavelengths and different incident angles

    International Nuclear Information System (INIS)

    Marciszko, Marianna; Baczmański, Andrzej; Braham, Chedly; Wróbel, Mirosław; Wroński, Sebastian; Cios, Grzegorz

    2017-01-01

    The presented study introduces the development of the multi-reflection grazing-incidence X-ray diffraction method (MGIXD) for residual stress determination. The proposed new methodology is aimed at obtaining more reliable experimental data and increasing the depth of non-destructive stress determination below the sample surface. To verify proposed method measurements were performed on a classical X-ray diffractometer (Cu Kα radiation) and using synchrotron radiation (three different wavelengths: λ = 1.2527 Å, λ = 1.5419 Å and λ = 1.7512 Å). The Al2017 alloy subjected to three different surface treatments was investigated in this study. The obtained results showed that the proposed development of MGIXD method, in which not only different incident angles but also different wavelengths of X-ray are used, can be successfully applied for residual stress determination, especially when stress gradients are present in the sample.

  13. Constellation-X to Generation-X: evolution of large collecting area moderate resolution grazing incidence x-ray telescopes to larger area high-resolution adjustable optics

    Science.gov (United States)

    Reid, Paul B.; Cameron, Robert A.; Cohen, Lester; Elvis, Martin; Gorenstein, Paul; Jerius, Diab; Petre, Robert; Podgorski, William A.; Schwartz, Daniel A.; Zhang, William W.

    2004-10-01

    Large collecting area x-ray telescopes are designed to study the early Universe, trace the evolution of black holes, stars and galaxies, study the chemical evolution of the Universe, and study matter in extreme environments. The Constellation-X mission (Con-X), planned for launch in 2016, will provide ~ 10^4 cm^2 collecting area with 15 arc-sec resolution, with a goal of 5 arc-sec. Future missions require larger collecting area and finer resolution. Generation-X (Gen-X), a NASA Visions Mission, will achieve 100 m^2 effective area at 1 keV and angular resolution of 0.1 arc-sec, half power diameter. We briefly describe the Con-X flowdown of imaging requirements to reflector figure error. To meet requirements beyond Con-X, Gen-X optics will be thinner and more accurately shaped than has ever been accomplished. To meet these challenging goals, we incorporate for the first time active figure control with grazing incidence optics. Piezoelectric material will be deposited in discrete cells directly on the back surface of the optical segments, with the strain directions oriented parallel to the surface. Differential strain between the two layers of the mirror causes localized bending in two directions, enabling local figure control. Adjusting figure on-orbit eases fabrication and metrology. The ability to make changes to mirror figure adds margin by mitigating risk due to launch-induced deformations and/or on-orbit degradation. We flowdown the Gen-X requirements to mirror figure and four telescope designs, and discuss various trades between the designs.

  14. In situ electrochemical impedance spectroscopy/synchrotron radiation grazing incidence X-ray diffraction-A powerful new technique for the characterization of electrochemical surfaces and interfaces

    Energy Technology Data Exchange (ETDEWEB)

    De Marco, Roland [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia)]. E-mail: r.demarco@exchange.curtin.edu.au; Jiang, Z.-T. [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia); Martizano, Jay [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia); Lowe, Alex [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia); Pejcic, Bobby [Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia); Riessen, Arie van [Materials Research Group, Department of Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth, WA 6845 (Australia)

    2006-08-15

    A marriage of electrochemical impedance spectroscopy (EIS) and in situ synchrotron radiation grazing incidence X-ray diffraction (SR-GIXRD) has provided a powerful new technique for the elucidation of the mechanistic chemistry of electrochemical systems. In this study, EIS/SR-GIXRD has been used to investigate the influence of metal ion buffer calibration ligands, along with natural organic ligands in seawater, on the behaviour of the iron chalcogenide glass ion-selective electrode (ISE). The SR-GIXRD data demonstrated that citrate - a previously reported poor iron calibration ligand for the analysis of seawater - induced an instantaneous and total dissolution of crystalline GeSe and Sb{sub 2}Se{sub 3} in the modified surface layer (MSL) of the ISE, while natural organic ligands in seawater and a mixture of ligands in a mimetic seawater ligand system protected the MSL's crystalline inclusions of GeSe and Sb{sub 2}Se{sub 3} from oxidative attack. Expectedly, the EIS data showed that citrate induced a loss in the medium frequency time constant for the MSL of the ISE, while seawater's natural organic ligands and the mimetic ligand system preserved the medium frequency EIS response characteristics of the ISE's MSL. The new EIS/SR-GIXRD technique has provided insights into the suitability of iron calibration ligands for the analysis of iron in seawater.

  15. Hot slumping glass technology for the grazing incidence optics of future missions with particular reference to IXO

    Science.gov (United States)

    Ghigo, M.; Basso, S.; Bavdaz, M.; Conconi, P.; Citterio, O.; Civitani, M.; Friedrich, P.; Gallieni, D.; Guldimann, B.; Martelli, F.; Negri, R.; Pagano, G.; Pareschi, G.; Parodi, G.; Proserpio, L.; Salmaso, B.; Scaglione, F.; Spiga, D.; Tagliaferri, G.; Terzi, L.; Tintori, M.; Vongehr, M.; Wille, E.; Winter, A.; Zambra, A.

    2010-07-01

    The mirrors of the International X-ray Observatory (IXO) consist of a large number of high quality segments delivering a spatial resolution better than 5 arcsec. A study concerning the slumping of thin glass foils for the IXO mirrors is under development in Europe, funded by ESA and led by the Brera Observatory. We are investigating two approaches, the "Direct" and "Indirect" slumping technologies, being respectively based on the use of convex and concave moulds. In the first case during the thermal cycle the optical surface of the glass is in direct contact with the mould surface, while in the second case it is the rear side of the foil which touches the master. Both approaches present pros and cons and aim of this study is also to make an assessment of both processes and to perform a trade-off between the two. The thin plates are made of D263glass produced by Schott. Each plate is 0.4 mm thick, with a reflecting area of 200 mm x 200 mm; the mould are made of Fused Silica. After the thermal cycle the slumped MPs are characterized to define their optical quality and microroughness. The adopted integration process foresees the bonding of the slumped foils to a rigid backplane by means of reinforcing ribs. During the bonding process the plates are constrained to stay in close contact to the surface of the master (i.e. the same mould used for the hot slumping process) by the application of a vacuum pump suction. In this way spring-back deformations and low frequency errors still present on the foil profile after slumping can be corrected. In this paper we present the preliminary results concerning achieved during the first part of the project.

  16. Grazing incidence diffraction : A review

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, B [LTPCM, ENSEEG. St. Martin d` Heres. (France)

    1996-09-01

    Different Grazing Incidence Diffraction (GID) methods for the analysis of thin films and multilayer structures are reviewed in three sections: the reflectivity is developed in the first one, which includes the non-specular diffuse scattering. The second one is devoted to the extremely asymmetric Bragg diffraction and the third one to the in-plane Bragg diffraction. Analytical formulations of the scattered intensities are developed for each geometry, in the framework of the kinetical analysis as well as the dynamical theory. Experimental examples are given to illustrate the quantitative possibility of the GID techniques.

  17. X-ray grazing incidence diffraction from multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tixier, S.; Boeni, P.; Swygenhoven, H. van; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Grazing incidence scattering geometries using synchrotron radiation have been applied in order to characterise the roughness profiles and the structural coherence of multilayers. The lateral correlation length of the roughness profiles was evaluated using diffuse reflectivity in the `out of plane` geometry. This type of measurement is the only diffuse reflectivity technique allowing large lateral momentum transfer. It is typically suitable for correlation lengths smaller than 1000 A. The lateral structural coherence length of Ni{sub 3}Al/Ni multilayers as a function of the layer thickness was obtained by grazing incidence diffraction (GID). 3 figs., 1 ref.

  18. Grazing-incident PIXE Analysis Technology

    International Nuclear Information System (INIS)

    Li Hongri; Wang Guangpu; Liang Kun; Yang Ru; Han Dejun

    2009-01-01

    In the article, the grazing incidence technology is first applied to the PIXE (proton induced X-ray emission) analysis. Three pieces of samples were investigated, including the contaminated aluminium substrate, the SIMOX (separated by oxygen implantation) SOI (Silicon on Insulator) sample and the silicon wafer implanted with Fe + . The results reveal that the grazing-incident proton can improve the sensitivity of PIXE in trace analysis, especially for samples contaminated on surface. With the penetration depth of the proton bean decreased, the ratio of the peak area to the detection limit raised observably and the sensitivity near the sample surface increased. (authors)

  19. Grazing incidence polarized neutron scattering in reflection ...

    Indian Academy of Sciences (India)

    journal of. January 2012 physics pp. 1–58. Grazing incidence polarized ..... atomic distances, the neutron has an energy which is low compared to molecular binding ...... cores and that of the Co ions in the AF oxide coatings. ...... [32] C Leighton, M R Fitzsimmons, P Yashar, A Hoffmann, J Nogus, J Dura, C F Majkrzak and.

  20. Grazing incidence angle based sensing approach integrated with fiber-optic Fourier transform infrared (FO-FTIR) spectroscopy for remote and label-free detection of medical device contaminations

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Moinuddin, E-mail: moinuddin.hassan@fda.hhs.gov; Ilev, Ilko [Optical Therapeutics and Medical Nanophotonics Laboratory, Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States)

    2014-10-15

    Contamination of medical devices has become a critical and prevalent public health safety concern since medical devices are being increasingly used in clinical practices for diagnostics, therapeutics and medical implants. The development of effective sensing methods for real-time detection of pathogenic contamination is needed to prevent and reduce the spread of infections to patients and the healthcare community. In this study, a hollow-core fiber-optic Fourier transform infrared spectroscopy methodology employing a grazing incidence angle based sensing approach (FO-FTIR-GIA) was developed for detection of various biochemical contaminants on medical device surfaces. We demonstrated the sensitivity of FO-FTIR-GIA sensing approach for non-contact and label-free detection of contaminants such as lipopolysaccharide from various surface materials relevant to medical device. The proposed sensing system can detect at a minimum loading concentration of approximately 0.7 μg/cm{sup 2}. The FO-FTIR-GIA has the potential for the detection of unwanted pathogen in real time.

  1. The SSRL ultrahigh vacuum grazing incidence monochromator: design considerations and operating experience

    International Nuclear Information System (INIS)

    Brown, F.C.; Bachrach, R.Z.; Lien, N.

    1978-01-01

    Considerable experience has now accumulated with the 'grasshopper' monochromator installed on the four degree line at the Stanford Synchrotron Radiation Laboratory. This is one of the first bakeable high vacuum instruments for use with a storage ring source in the photon energy range 25 to 1000 eV. The unique features of this instrument will be discussed from a general point of view, including the source emittance and the transforming properties of the beam line plus monochromator. Actual performance figures will be given in order to better appraise the limits of focusing optics and gratings at two degree grazing incidence. Improvements such as post-monochromator optics, isolation valves and provisions for adjustment will be briefly discussed. (Auth.)

  2. The Marshall Grazing Incidence X-ray Spectrometer

    Science.gov (United States)

    Kobayashi, Ken; Winebarger, Amy R.; Savage, Sabrina; Champey, Patrick; Cheimets, Peter N.; Hertz, Edward; Bruccoleri, Alexander R.; Golub, Leon; Ramsey, Brian; Ranganathan, Jaganathan; Marquez, Vanessa; Allured, Ryan; Parker, Theodore; Heilmann, Ralf K.; Schattenburg, Mark L.

    2017-08-01

    The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument designed to obtain spatially resolved soft X-ray spectra of the solar atmosphere in the 6-24 Å (0.5-2.0 keV) range. The instrument consists of a single shell Wolter Type-I telescope, a slit, and a spectrometer comprising a matched pair of grazing incidence parabolic mirrors and a planar varied-line space diffraction grating. The instrument is designed to achieve a 50 mÅ spectral resolution and 5 arcsecond spatial resolution along a +/-4-arcminute long slit, and launch is planned for 2019. We report on the status and our approaches for fabrication and alignment for this novel optical system. The telescope and spectrometer mirrors are replicated nickel shells, and are currently being fabricated at the NASA Marshall Space Flight Center. The diffraction grating is currently under development by the Massachusetts Institute of Technology (MIT); because of the strong line spacing variation across the grating, it will be fabricated through e-beam lithography.

  3. Grazing incidence EUV study of the Alcator tokamaks

    International Nuclear Information System (INIS)

    Castracane, J.

    1982-01-01

    The use of impurity radiation to examine plasma conditions is a well known technique. To gain access, however, to the hot, central portion of the plasma created in the present confinement machines it is necessary to be able to observe radiation from medium and heavy elements such as molybdenum and iron. These impurities radiate primarily in the extreme ultra violet region of the spectrum and can play a role in the power balance of the tokamak. Radiation from highly ionized molybdenum was examined on the Alcator A and C tokamaks using a photometrically calibrated one meter grazing incidence monochromator. On Alcator A, a pseudo-continuum of Mo emissions in the 60 to 100 A ranges were seen to comprise 17% of the radiative losses from the plasma. This value closely matched measurements by a broad band bolometer array. Following these preliminary measurements, the monochromator was transferred to Alcator C for a more thorough examination of EUV emissions. Deviations from predicted scaling laws for energy confinement time vs density were observed on this machine

  4. Properties of grazing-incidence pulsed Ti:sapphire laser oscillator

    International Nuclear Information System (INIS)

    Tamura, Koji

    2008-03-01

    A pulsed operation of a grazing-incidence double-grating Ti:sapphire laser oscillator that consists of a gain medium, back mirror, and a pair of gratings, was studied. A stable single-longitudinal-mode operation was achievable. From the calculation of the optical path trajectories, it can be explained by the increased beam walk-off from the gain medium by the introduction of the second grating compared with the conventional single-grating grazing-incidence cavity geometry. The improved spectral property was also explained by the calculations of increased dispersion. The results indicate that the oscillator configuration was useful for the applications which require stable mode operation and narrow linewidth such as the high resolution spectroscopy or the laser isotope separation. (author)

  5. Opto-mechanical Analyses for Performance Optimization of Lightweight Grazing-incidence Mirrors

    Science.gov (United States)

    Roche, Jacqueline M.; Kolodziejczak, Jeffery J.; Odell, Stephen L.; Elsner, Ronald F.; Weisskopf, Martin C.; Ramsey, Brian; Gubarev, Mikhail V.

    2013-01-01

    New technology in grazing-incidence mirror fabrication and assembly is necessary to achieve subarcsecond optics for large-area x-ray telescopes. In order to define specifications, an understanding of performance sensitivity to design parameters is crucial. MSFC is undertaking a systematic study to specify a mounting approach, mirror substrate, and testing method. Lightweight mirrors are typically flimsy and are, therefore, susceptible to significant distortion due to mounting and gravitational forces. Material properties of the mirror substrate along with its dimensions significantly affect the distortions caused by mounting and gravity. A parametric study of these properties and their relationship to mounting and testing schemes will indicate specifications for the design of the next generation of lightweight grazing-incidence mirrors. Here we report initial results of this study.

  6. Status of Mirror Development for the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS)

    Science.gov (United States)

    Champey, P. R.; Winebarger, A. R.; Kobayashi, K.; Savage, S. L.; Ramsey, B.; Kolodziejczak, J.; Speegle, C.; Young, M.; Kester, T.; Cheimets, P.; Hertz, E.

    2017-12-01

    The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument designed to observe soft X-ray emissions at 0.5 - 2.0 keV energies (24 - 6 Å) from a solar active region. MaGIXS will, for the first time, obtain spatially resolved spectra of high-temperature, low-emission plasma within an active region core. The unique optical design includes a Wolter I telescope and a 3-optic grazing incidence spectrograph. The spectrograph consists of a finite conjugate, stigmatic mirror pair and a planar varied line space grating. The grazing incidence mirrors are being developed at NASA Marshall Space Flight Center (MSFC) and are produced using electroform nickel-replication techniques, employing the same facilities developed for HERO, FOXSI, ART-XC and IXPE. The MaGIXS mirror mandrels have been fabricated, figured, and have completed the first phase of polishing. A set of three test shells were replicated and exposed to X-rays in the Stray Light Facility (SLF) at MSFC. Here we present results from mandrel metrology and X-ray testing at the SLF. We also discuss the development of a new polishing technique for the MaGIXS mirror mandrels, where we plan to use the Zeeko polishing machine.

  7. An X-ray grazing incidence phase multilayer grating

    CERN Document Server

    Chernov, V A; Mytnichenko, S V

    2001-01-01

    An X-ray grazing incidence phase multilayer grating, representing a thin grating placed on a multilayer mirror, is proposed. A high efficiency of grating diffraction can be obtained by the possibility of changing the phase shift of the wave diffracted from the multilayer under the Bragg and total external reflection conditions. A grazing incidence phase multilayer grating consisting of Pt grating stripes on a Ni/C multilayer and optimized for the hard X-ray range was fabricated. Its diffraction properties were studied at photon energies of 7 and 8 keV. The obtained maximum value of the diffraction efficiency of the +1 grating order was 9% at 7 keV and 6.5% at 8 keV. The data obtained are in a rather good accordance with the theory.

  8. Metrology of reflection optics for synchrotron radiation

    International Nuclear Information System (INIS)

    Takacs, P.Z.

    1985-09-01

    Recent years have seen an almost explosive growth in the number of beam lines on new and existing synchrotron radiation facilities throughout the world. The need for optical components to utilize the unique characteristics of synchrotron radiation has increased accordingly. Unfortunately, the technology to manufacture and measure the large, smooth, exotic optical surfaces required to focus and steer the synchrotron radiation beam has not progressed as rapidly as the operational demands on these components. Most companies do not wish to become involved with a project that requires producing a single, very expensive, aspheric optic with surface roughness and figure tolerances that are beyond their capabilities to measure. This paper will review some of the experiences of the National Synchrotron Light Source in procuring grazing incidence optical components over the past several years. We will review the specification process - how it is related to the function of the optic, and how it relates to the metrology available during the manufacturing process and after delivery to the user's laboratory. We will also discuss practical aspects of our experience with new technologies, such as single point diamond turning of metal mirrors and the use of SiC as a mirror material. Recent advances in metrology instrumentation have the potential to move the measurement of surface figure and finish from the research laboratory into the optical shop, which should stimulate growth and interest in the manufacturing of optics to meet the needs of the synchrotron radiation user community

  9. Surface quality inspection of PbWO4 crystals by grazing incidence X-ray diffraction

    International Nuclear Information System (INIS)

    Mengucci, P.; Di Cristoforo, A.; Lebeau, M.; Majni, G.; Paone, N.; Pietroni, P.; Rinaldi, D.

    2005-01-01

    High-quality scintillating crystals are required for applications in radiographic systems and high-energy physics detectors to achieve the specified optical properties. In order to study the state of the single crystals surface we propose the use of the grazing incidence X-ray diffraction (GID) technique. This technique allows performing a depth profiling of the sample by changing the incidence angle of the X-ray beam with respect to the sample surface. In this work, two samples of a large PbWO 4 (PWO) single crystal exhibiting different surface roughness values have been studied. Results have shown that GID is a suitable technique for surface quality inspection

  10. Characterization of X-UV multilayers by grazing incidence X-ray reflectometry

    International Nuclear Information System (INIS)

    Nevot, L.; Pardo, B.; Corno, J.

    1988-01-01

    The performance of multilayers at the X-UV wavelengths depends upon the structural and geometrical imperfections of the deposited materials. These two respective contributions are not easily separated when only one Bragg peak is recorded, as is usually the case in the X-UV range, so a prediction of the performance at other wavelengths appears rather doubtful. We show how grazing incidence X-ray reflectometry (using Cu Kα 1 radiation) allows the precise evaluation of both interfacial roughnesses and thickness errors, as well as their variations through the stacks. As examples, we analyse three (W/C) multilayers with periods between 3 to 6 nm and up to 40 layers

  11. Grazing incidence X-ray fluorescence analysis of buried interfaces in periodically structured crystalline silicon thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhauer, David; Preidel, Veit; Becker, Christiane [Young Investigator Group Nanostructured Silicon for Photovoltaic and Photonic Implementations (Nano-SIPPE), Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Pollakowski, Beatrix; Beckhoff, Burkhard [Physikalisch-Technische Bundesanstalt, Berlin (Germany); Baumann, Jonas; Kanngiesser, Birgit [Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin (Germany); Amkreutz, Daniel; Rech, Bernd [Institut Silizium Photovoltaik, Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Back, Franziska; Rudigier-Voigt, Eveline [SCHOTT AG, Mainz (Germany)

    2015-03-01

    We present grazing incidence X-ray fluorescence (GIXRF) experiments on 3D periodically textured interfaces of liquid phase crystallized silicon thin-film solar cells on glass. The influence of functional layers (SiO{sub x} or SiO{sub x}/SiC{sub x}) - placed between glass substrate and silicon during crystallization - on the final carbon and oxygen contaminations inside the silicon was analyzed. Baring of the buried structured silicon surface prior to GIXRF measurement was achieved by removal of the original nano-imprinted glass substrate by wet-chemical etching. A broad angle of incidence distribution was determined for the X-ray radiation impinging on this textured surface. Optical simulations were performed in order to estimate the incident radiation intensity on the structured surface profile considering total reflection and attenuation effects. The results indicate a much lower contamination level for SiO{sub x} compared to the SiO{sub x}/SiC{sub x} interlayers, and about 25% increased contamination when comparing structured with planar silicon layers, both correlating with the corresponding solar cell performances. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Tests of a grazing-incidence ring resonator free-electron laser

    International Nuclear Information System (INIS)

    Dowell, D.H.; Laucks, M.L.; Lowrey, A.R.; Adamski, J.L.; Pistoresi, D.J.; Shoffstall, D.R.; Bentz, M.P.; Burns, R.H.; Guha, J.; Sun, K.; Tomita, W.

    1991-01-01

    This paper reports on the Boeing free-electron laser (FEL) optical cavity that has been changed from a simple concentric cavity using two spherical mirrors to a larger grazing-incidence ring resonator. The new resonator consists of two mirror telescopes located at each end of the wiggler with a round-trip path length of approximately 133 m. Each telescope is a grazing-incidence hyperboloid followed by a normal-incidence paraboloid. Initial tests showed that poorly positioned ring focus and unreliable pointing alignment resulted in reduced and structured FEL output. (First lasing operation occurred on March 23 and 24, 1990.) Later efforts concentrated on improving the resonator alignment techniques and lowering the single-pass losses. FEL performance and reliability have significantly improved due to better ring alignment. The alignment procedure and recent lasing results are described. The effect the electron beam has on lasing is also discussed. Measurements are presented showing how FEL temporal output and wavelength are sensitive to electron beam energy variations

  13. Image processing for grazing incidence fast atom diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Debiossac, Maxime; Roncin, Philippe, E-mail: philippe.roncin@u-psud.fr

    2016-09-01

    Grazing incidence fast atom diffraction (GIFAD, or FAD) has developed as a surface sensitive technique. Compared with thermal energies helium diffraction (TEAS or HAS), GIFAD is less sensitive to thermal decoherence but also more demanding in terms of surface coherence, the mean distance between defects. Such high quality surfaces can be obtained from freshly cleaved crystals or in a molecular beam epitaxy (MBE) chamber where a GIFAD setup has been installed allowing in situ operation. Based on recent publications by Atkinson et al. (2014) and Debiossac et al. (2014), the paper describes in detail the basic steps needed to measure the relative intensities of the diffraction spots. Care is taken to outline the underlying physical assumptions.

  14. Design of grazing-incidence multilayer supermirrors for hard-X-ray reflectors

    DEFF Research Database (Denmark)

    Joensen, K. D.; Voutov, P.; Szentgyorgyi, A.

    1995-01-01

    Extremely broadband grazing-incidence multilayers for hard-X-ray reflection can be obtained by a gradual change of the layer thicknesses down through the structure. Existing approaches for designing similar neutron optics, called supermirrors, are shown to provide respectable performance when...... applied to X-ray multilayers. However, none of these approaches consider the effects of imperfect layer interfaces and absorption in the overlying layers. Adaptations of neutron designs that take these effects into account are presented, and a thorough analysis of two specific applications (a single hard......-X-ray reflector and a hard-X-ray telescope) shows that an improved performance can be obtained. A multilayer whose bilayer thicknesses are given by a power law expression is found to provide the best solution; however, it is only slightly better than some of the adapted neutron designs...

  15. Nested grazing incidence optics for x ray detection

    Science.gov (United States)

    Li, Lin-Sen; Qiang, Peng-Fei; Sheng, Li-Zhi; Liu, Yong-An; Liu, Zhe; Liu, Duo; Zhao, Bao-Sheng; Zhang, Chun-Min

    2017-09-01

    Not Available Project supported by the National Natural Science Foundation of China (Grant No. 61471357) and the State Key Laboratory of Geo-Information Engineering Foundation (Grant No. SKLGIE2014-M-2-1).

  16. Analysis of buried interfaces in multilayer mirrors using grazing incidence extreme ultraviolet reflectometry near resonance edges.

    Science.gov (United States)

    Sertsu, M G; Nardello, M; Giglia, A; Corso, A J; Maurizio, C; Juschkin, L; Nicolosi, P

    2015-12-10

    Accurate measurements of optical properties of multilayer (ML) mirrors and chemical compositions of interdiffusion layers are particularly challenging to date. In this work, an innovative and nondestructive experimental characterization method for multilayers is discussed. The method is based on extreme ultraviolet (EUV) reflectivity measurements performed on a wide grazing incidence angular range at an energy near the absorption resonance edge of low-Z elements in the ML components. This experimental method combined with the underlying physical phenomenon of abrupt changes of optical constants near EUV resonance edges enables us to characterize optical and structural properties of multilayers with high sensitivity. A major advantage of the method is to perform detailed quantitative analysis of buried interfaces of multilayer structures in a nondestructive and nonimaging setup. Coatings of Si/Mo multilayers on a Si substrate with period d=16.4  nm, number of bilayers N=25, and different capping structures are investigated. Stoichiometric compositions of Si-on-Mo and Mo-on-Si interface diffusion layers are derived. Effects of surface oxidation reactions and carbon contaminations on the optical constants of capping layers and the impact of neighboring atoms' interactions on optical responses of Si and Mo layers are discussed.

  17. Ray-tracing of shape metrology data of grazing incidence x-ray astronomy mirrors

    Science.gov (United States)

    Zocchi, Fabio E.; Vernani, Dervis

    2008-07-01

    A number of future X-ray astronomy missions (e.g. Simbol-X, eROSITA) plan to utilize high throughput grazing incidence optics with very lightweight mirrors. The severe mass specifications require a further optimization of the existing technology with the consequent need of proper optical numerical modeling capabilities for both the masters and the mirrors. A ray tracing code has been developed for the simulation of the optical performance of type I Wolter masters and mirrors starting from 2D and 3D metrology data. In particular, in the case of 2D measurements, a 3D data set is reconstructed on the basis of dimensional references and used for the optical analysis by ray tracing. In this approach, the actual 3D shape is used for the optical analysis, thus avoiding the need of combining the separate contributions of different 2D measurements that require the knowledge of their interactions which is not normally available. The paper describes the proposed approach and presents examples of application on a prototype engineering master in the frame of ongoing activities carried out for present and future X-ray missions.

  18. Grazing incidence x-ray diffraction at free-standing nanoscale islands: fine structure of diffuse scattering

    International Nuclear Information System (INIS)

    Grigoriev, D; Hanke, M; Schmidbauer, M; Schaefer, P; Konovalov, O; Koehler, R

    2003-01-01

    We have investigated the x-ray intensity distribution around 220 reciprocal lattice point in case of grazing incidence diffraction at SiGe nanoscale free-standing islands grown on Si(001) substrate by LPE. Experiments and computer simulations based on the distorted wave Born approximation utilizing the results of elasticity theory obtained by FEM modelling have been carried out. The data reveal fine structure in the distribution of scattered radiation with well-pronounced maxima and complicated fringe pattern. Explanation of the observed diffraction phenomena in their relation to structure and morphology of the island is given. An optimal island model including its shape, size and Ge spatial distribution was elaborated

  19. Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) Slit-Jaw Imaging System

    Science.gov (United States)

    Wilkerson, P.; Champey, P. R.; Winebarger, A. R.; Kobayashi, K.; Savage, S. L.

    2017-12-01

    The Marshall Grazing Incidence X-ray Spectrometer is a NASA sounding rocket payload providing a 0.6 - 2.5 nm spectrum with unprecedented spatial and spectral resolution. The instrument is comprised of a novel optical design, featuring a Wolter1 grazing incidence telescope, which produces a focused solar image on a slit plate, an identical pair of stigmatic optics, a planar diffraction grating and a low-noise detector. When MaGIXS flies on a suborbital launch in 2019, a slit-jaw camera system will reimage the focal plane of the telescope providing a reference for pointing the telescope on the solar disk and aligning the data to supporting observations from satellites and other rockets. The telescope focuses the X-ray and EUV image of the sun onto a plate covered with a phosphor coating that absorbs EUV photons, which then fluoresces in visible light. This 10-week REU project was aimed at optimizing an off-axis mounted camera with 600-line resolution NTSC video for extremely low light imaging of the slit plate. Radiometric calculations indicate an intensity of less than 1 lux at the slit jaw plane, which set the requirement for camera sensitivity. We selected a Watec 910DB EIA charge-coupled device (CCD) monochrome camera, which has a manufacturer quoted sensitivity of 0.0001 lux at F1.2. A high magnification and low distortion lens was then identified to image the slit jaw plane from a distance of approximately 10 cm. With the selected CCD camera, tests show that at extreme low-light levels, we achieve a higher resolution than expected, with only a moderate drop in frame rate. Based on sounding rocket flight heritage, the launch vehicle attitude control system is known to stabilize the instrument pointing such that jitter does not degrade video quality for context imaging. Future steps towards implementation of the imaging system will include ruggedizing the flight camera housing and mounting the selected camera and lens combination to the instrument structure.

  20. Side-pumped Nd:YVO4 cw laser with grazing-incidence small angle configuration

    International Nuclear Information System (INIS)

    Camargo, Fabiola de Almeida

    2006-01-01

    Within the existing variety of laser cavity geometries and gain materials there is one combination that is particularly interesting because of its reduced complexity and high efficiency: the edge-pumped slab-laser using grazing-incidence geometry and a gain media with a very high pump absorption cross-section. In this work we studied a diode side-pumped Nd:YVO 4 cw laser. We describe a single and a multiple bounce laser configurations. We demonstrate 22 W of multimode output power for 35 watts of pump power with a single pass through the gain media. A high optical-to-optical conversion efficiency of 63% and a slope efficiency of 74% with a very compact and simple Nd:YVO 4 cavity that uses joint stability zones was achieved. The beam quality was M 2 = 26 x 11 in the horizontal and vertical direction, respectively. With a double pass configuration we achieved 17 watts with a better beam quality of M 2 = 3,4 x 3,7, in the horizontal and vertical direction, respectively. (author)

  1. Depth distribution of chemical phase concentration determined by grazing incidence X-ray diffraction

    International Nuclear Information System (INIS)

    Novak, P.; Ballo, P.; Dobrocka, E.; Vallo, M.; Lalinsky, T.

    2013-01-01

    Grazing incidence geometry is widely used in X-ray diffraction analysis of thin films. Penetration depth of radiation can be easily changed by an appropriate selection of the angle of incidence α that enables obtaining information from different depths of the sample. This depth can be decreased up to a nanometer scale by approaching the critical angle α_c for total external reflection. This method therefore provides an efficient tool for the analysis of depth distribution of various structural properties, such as the crystallite size, the amorphous fraction, stress or the concentration of chemical phase. However, absorption of the radiation can be characterized by an average attenuation coefficient μ a special care has to be paid to the last property. Variation of chemical phase concentration with depth usually results in depth dependence on the attenuation coefficient. In this contribution a method for determination of depth distribution of a chemical phase is outlined. The method correctly takes into account the depth variation of the attenuation coefficient. The method is tested on thin oxidized Ir layers. The aim of this paper is a comparison two simple model cases with the experimental results. (authors)

  2. Direct intensity calibration of X-ray grazing-incidence microscopes with home-lab source

    Science.gov (United States)

    Li, Yaran; Xie, Qing; Chen, Zhiqiang; Xin, Qiuqi; Wang, Xin; Mu, Baozhong; Wang, Zhanshan; Liu, Shenye; Ding, Yongkun

    2018-01-01

    Direct intensity calibration of X-ray grazing-incidence microscopes is urgently needed in quantitative studies of X-ray emission from laser plasma sources in inertial confinement fusion. The existing calibration methods for single reflecting mirrors, crystals, gratings, filters, and X-ray detectors are not applicable for such X-ray microscopes due to the specific optical structure and the restrictions of object-image relation. This article presents a reliable and efficient method that can be performed using a divergent X-ray source and an energy dispersive Si-PIN (silicon positive-intrinsic-negative) detector in an ordinary X-ray laboratory. The transmission theory of X-ray flux in imaging diagnostics is introduced, and the quantities to be measured are defined. The calibration method is verified by a W/Si multilayer-coated Kirkpatrick-Baez microscope with a field of view of ˜95 μm at 17.48 keV. The mirror reflectance curve in the 1D coordinate is drawn with a peak value of 20.9% and an uncertainty of ˜6.0%.

  3. X-ray grazing incidence study of inhomogeneous strain relaxation in Si/SiGe wires

    International Nuclear Information System (INIS)

    Hesse, A.; Zhuang, Y.; Holy, V.; Stangl, J.; Zerlauth, S.; Schaeffler, F.; Bauer, G.; Darowski, N.; Pietsch, U.

    2003-01-01

    The elastic strain relaxation in a series of dry-etched periodic multilayer Si/SiGe wire samples with different etching depths was investigated systematically by means of grazing incidence diffraction (GID). The samples were patterned by holographic lithography and reactive ion etching from a Si/SiGe superlattice grown by molecular beam epitaxy. Scanning electron microscopy and atomic force microscopy were employed to obtain information on the shape of the wires. The inhomogeneous strain distribution in the etched wires and in the non-etched part of the multilayers was derived by means of finite element calculations which were used as an input for simulations of the scattered X-ray intensities in depth dependent GID. The theoretical calculations for the scattered intensities are based on distorted-wave Born approximation. The unperturbed scattering potential was chosen with a reduced optical density corresponding to the ratio of wire width and wire period, in order to reflect the main interaction between the incident X-rays and the patterned samples. The calculations are in good agreement with the experimental data demonstrating the variation of strain relaxation with depth

  4. Advanced laser-backlit grazing-incidence x-ray imaging systems for inertial confinement fusion research. II. Tolerance analysis

    International Nuclear Information System (INIS)

    Bennett, Guy R.; Folta, James A.

    2001-01-01

    Two example ultrahigh-spatial resolution laser-backlit grazing-incidence x-ray microscope designs for inertial confinement fusion (ICF) research have been described [Appl. Opt. 40, 4570 (2001)]. Here details of fabrication, assembly, and optical surface errors that are characteristic of present state-of-the-art superpolished multilayer-coated spherical mirrors are given. They indicate that good image qualities can be expected; in particular, <0.5-μm spatial resolution at very high x-ray energies (up to 25 keV) appears to be feasible. Existing ICF imaging diagnostics approach ∼2 μm spatial at low (<2 keV) energy. The improvement in resolution compared with that of other grazing-incidence devices is attributed to a fortuitous residual on-axis aberration dependence on short wavelengths; recent advances in mirror fabrication, including a new thin-film deposition technique to correct figure errors precisely in one dimension; and novel design. For even higher resolution, a means of creating precise aspherical mirrors of spheric-quality microroughness may be possible by use of the same deposition technique

  5. Fluence thresholds for grazing incidence hard x-ray mirrors

    Czech Academy of Sciences Publication Activity Database

    Aquila, A.; Sobierajski, R.; Ozkan, C.; Hájková, Věra; Burian, Tomáš; Chalupský, Jaromír; Juha, Libor; Störmer, M.; Bajt, S.; Klepka, M.T.; Dlužewski, P.; Morawiec, K.; Ohashi, H.; Koyama, T.; Tono, K.; Inubushi, Y.; Yabashi, M.; Sinn, H.; Tschentscher, T.; Mancuso, A.P.; Gaudin, J.

    2015-01-01

    Roč. 106, č. 24 (2015), "241905-1"-"241905-5" ISSN 0003-6951 R&D Projects: GA ČR(CZ) GA14-29772S Grant - others:AVČR(CZ) M100101221 Institutional support: RVO:68378271 Keywords : XFEL * Free Electron Laser * damage threshold * X-ray optics Subject RIV: BH - Optics , Masers, Lasers Impact factor: 3.142, year: 2015

  6. Grazing incidence small angle X-ray scattering study of silver nanoparticles in ion-exchanged glasses

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Weidong, E-mail: 57399942@qq.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Wu, Zhaojun [Department of Practice Teaching and Equipment Management, Qiqihar University, Qiqihar 161006 (China); Gu, Xiaohua [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Xing, Xueqing; Mo, Guang [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wu, Zhonghua, E-mail: wuzh@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-05-15

    The size and distribution of silver nanoparticles in ion-exchanged silicate glass induced by thermal treatments in air at different temperatures were investigated by means of grazing incidence small angle X-ray scattering technique, X-ray diffraction and optical absorption spectra. Silver–sodium ion exchange of soda-lime silicate glasses was done at 350 °C for 240 min, then the samples were treated by thermal annealing in air at different temperatures 400, 500 and 550 °C, respectively, for 1 h. After the annealing treatment above 400 °C for 1 h, smaller Ag nanoparticles occurred, together with bigger ones. Both dissolution of smaller Ag nanoparticles and diffusion of larger ones are discussed in these stages of annealing in this contribution.

  7. Grazing incidence Fe-line telescopes using W/B4C multilayers

    DEFF Research Database (Denmark)

    Joensen, K. D.; Gorenstein, P.; Christensen, Finn Erland

    1995-01-01

    The loss of throughput observed at higher energies for traditional grazing-incidence X-ray telescopes coated with high-Z elements can be partly countered by employing multilayers on the outermost reflectors. Using 8-keV reflectivity data from a periodic W/B4C multilayer, the expected performance...

  8. Multiple scattering in grazing-incidence X-ray diffraction: impact on lattice-constant determination in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Resel, Roland, E-mail: roland.resel@tugraz.at; Bainschab, Markus; Pichler, Alexander [Graz University of Technology, Graz (Austria); Dingemans, Theo [Delft University of Technology, Delft (Netherlands); Simbrunner, Clemens [Johannes Kepler University, Linz (Austria); University of Bremen, Bremen (Germany); Stangl, Julian [Johannes Kepler University, Linz (Austria); Salzmann, Ingo [Humboldt University, Berlin (Germany)

    2016-04-20

    The use of grazing-incidence X-ray diffraction to determine the crystal structure from thin films requires accurate positions of Bragg peaks. Refraction effects and multiple scattering events have to be corrected or minimized. Dynamical scattering effects are observed in grazing-incidence X-ray diffraction experiments using an organic thin film of 2,2′:6′,2′′-ternaphthalene grown on oxidized silicon as substrate. Here, a splitting of all Bragg peaks in the out-of-plane direction (z-direction) has been observed, the magnitude of which depends both on the incidence angle of the primary beam and the out-of-plane angle of the scattered beam. The incident angle was varied between 0.09° and 0.25° for synchrotron radiation of 10.5 keV. This study reveals comparable intensities of the split peaks with a maximum for incidence angles close to the critical angle of total external reflection of the substrate. This observation is rationalized by two different scattering pathways resulting in diffraction peaks at different positions at the detector. In order to minimize the splitting, the data suggest either using incident angles well below the critical angle of total reflection or angles well above, which sufficiently attenuates the contributions from the second scattering path. This study highlights that the refraction of X-rays in (organic) thin films has to be corrected accordingly to allow for the determination of peak positions with sufficient accuracy. Based thereon, a reliable determination of the lattice constants becomes feasible, which is required for crystallographic structure solutions from thin films.

  9. Development of grazing incidence devices for space-borne time of flight mass spectrometry

    Science.gov (United States)

    Cadu, A.; Devoto, P.; Louarn, P.; Sauvaud, J.-A.

    2012-04-01

    Time of flight mass spectrometer is widely used to study space plasmas in planetary and solar missions. This space-borne instrument selects ions in function of their energy through an electrostatic analyzer. Particles are then post-accelerated to energies in the range of 20 keV to cross a carbon foil. At the foil exit, electrons are emitted and separated from ion beam in the time of flight section. A first detector (a Micro-Channel Plate or MCP) emits a start signal at electron arrival and a second one emits a stop signal at incident ion end of path. The time difference gives the speed of the particle and its mass can be calculated, knowing its initial energy. However, current instruments suffer from strong limitations. The post acceleration needs very high voltage power supplies which are heavy, have a high power consumption and imply technical constraints for the development. A typical instrument weighs from 5 to 6 kg, includes a 20 kV power supply, consumes a least 5 W and encounters corona effect and electrical breakdown problems. Moreover, despite the particle high energy range, scattering and straggling phenomena in the carbon foil significantly reduce the instrument overall resolution. Some methods, such as electrostatic focus lenses or reflectrons, really improve mass separation but global system efficiency remains very low because of the charge state dependence of such devices. The main purpose of our work is to replace carbon foil by grazing incidence MCP's - also known as MPO's, for Micro Pore Optics - for electron emission. Thus, incident particles would back-scatter onto the channel inner surface with an angle of a few degrees. With this solution, we can decrease dispersion sources and lower the power supplies to post accelerate ions. The result would be a lighter and simpler instrument with a substantial resolution improvement. We have first simulated MPO's behavior with TRIM and MARLOWE Monte-Carlo codes. Energy scattering and output angle computed

  10. SPRED: a multichannel grazing-incidence spectrometer for plasma impurity diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Fonck, R.J.; Ramsey, A.T.; Yelle, R.V.

    1982-03-01

    A compact vacuum ultraviolet spectrometer system has been developed to provide time-resolved impurity spectra from tokamak plasmas. Two interchangeable aberration-corrected toroidal diffraction gratings with flat focal fields provide simultaneous coverage over the ranges 100 to 1100 A or 160 to 1700 A. The detector is an intensified self-scanning photodiode array. Spectral resolution is 2 A with the higher dispersion grating. Minimum readout time for a full spectrum is 20 ms, but up to 7 individual spectral lines can be measured with a 1 ms time resolution. The sensitivity of the system is comparable to that of a conventional grazing incidence monochromator.

  11. SPRED: a multichannel grazing-incidence spectrometer for plasma impurity diagnosis

    International Nuclear Information System (INIS)

    Fonck, R.J.; Ramsey, A.T.; Yelle, R.V.

    1982-03-01

    A compact vacuum ultraviolet spectrometer system has been developed to provide time-resolved impurity spectra from tokamak plasmas. Two interchangeable aberration-corrected toroidal diffraction gratings with flat focal fields provide simultaneous coverage over the ranges 100 to 1100 A or 160 to 1700 A. The detector is an intensified self-scanning photodiode array. Spectral resolution is 2 A with the higher dispersion grating. Minimum readout time for a full spectrum is 20 ms, but up to 7 individual spectral lines can be measured with a 1 ms time resolution. The sensitivity of the system is comparable to that of a conventional grazing incidence monochromator

  12. Electrochemically adsorbed Pb on Ag (111) studied with grazing- incidence x-ray scattering

    International Nuclear Information System (INIS)

    Kortright, J.B.; Ross, P.N.; Melroy, O.R.; Toney, M.F.; Borges, G.L.; Samant, M.G.

    1989-04-01

    Grazing-incidence x-ray scattering studies of the evolution of electrochemically deposited layers of lead on silver (111) as a function of applied electrochemical potential are presented. Measurements were made with the adsorbed layers in contact with solution in a specially designed sample cell. The observed lead structures are a function of the applied potential and range from an incommensurate monolayer, resulting from underpotential deposition, to randomly oriented polycrystalline bulk lead, resulting from lower deposition potentials. These early experiments demonstrate the ability of in situ x-ray diffraction measurements to determine structures associated with electrochemical deposition. 6 refs., 4 figs

  13. Electron emission induced by resonant coherent ion-surface interaction at grazing incidence

    International Nuclear Information System (INIS)

    Garcia de Abajo, F.J.; Ponce, V.H.; Echenique, P.M.

    1992-01-01

    A new spectroscopy based on the resonant coherently induced electron loss to the continuum in ion-surface scattering under grazing incidence is proposed. A series of peaks, corresponding to the energy differences determined by the resonant interaction with the rows of atoms in the surface, is predicted to appear in the energy distribution of electrons emitted from electronic states bound to the probe. Calculations for MeV He + ions scattered at a W(001) surface along the left-angle 100 right-angle direction with a glancing angle of 0--2 mrad show a total yield close to 1

  14. Radiation optic neuropathy

    International Nuclear Information System (INIS)

    Kline, L.B.; Kim, J.Y.; Ceballos, R.

    1985-01-01

    Following surgery for pituitary adenoma, radiation therapy is an accepted treatment in reducing tumor recurrence. However, a potential therapeutic complication is delayed radionecrosis of perisellar neural structures, including the optic nerves and chiasm. This particular cause of visual loss, radiation optic neuropathy (RON), has not been emphasized in the ophthalmologic literature. Four cases of RON seen in the past five years are reported. Diagnostic criteria include: (1) acute visual loss (monocular or binocular), (2) visual field defects indicating optic nerve or chiasmal dysfunction, (3) absence of optic disc edema, (4) onset usually within three years of therapy (peak: 1-1 1/2 years), and (5) no computed tomographic evidence of visual pathway compression. Pathologic findings, differential diagnosis and therapy will be discussed in outlining the clinical profile of RON

  15. Ion-induced nanopatterns on semiconductor surfaces investigated by grazing incidence x-ray scattering techniques

    Energy Technology Data Exchange (ETDEWEB)

    Carbone, D; Metzger, T H [ID01, ESRF, 6 rue Jules Horowitz, F-38043 Grenoble Cedex (France); Biermanns, A; Pietsch, U [Festkoerperphysik, Universitaet Siegen, D-57068 Siegen (Germany); Ziberi, B; Frost, F [Leibniz-Institut fuer Oberflaechenmodifizierung e.V., D-04318 Leipzig (Germany); Plantevin, O [Universite Paris-Sud, Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, UMR 8609, F-91405 Orsay (France)], E-mail: gcarbone@esrf.fr

    2009-06-03

    In this review we cover and describe the application of grazing incidence x-ray scattering techniques to study and characterize nanopattern formation on semiconductor surfaces by ion beam erosion under various conditions. It is demonstrated that x-rays under grazing incidence are especially well suited to characterize (sub)surface structures on the nanoscale with high spatial and statistical accuracy. The corresponding theory and data evaluation is described in the distorted wave Born approximation. Both ex situ and in situ studies are presented, performed with the use of a specially designed sputtering chamber which allows us to follow the temporal evolution of the nanostructure formation. Corresponding results show a general stabilization of the ordering wavelength and the extension of the ordering as a function of the ion energy and fluence as predicted by theory. The in situ measurements are especially suited to study the early stages of pattern formation, which in some cases reveal a transition from dot to ripple formation. For the case of medium energy ions crystalline ripples are formed buried under a semi-amorphous thick layer with a ripple structure at the surface being conformal with the crystalline/amorphous interface. Here, the x-ray techniques are especially advantageous since they are non-destructive and bulk-sensitive by their very nature. In addition, the GI x-ray techniques described in this review are a unique tool to study the evolving strain, a topic which remains to be explored both experimentally and theoretically.

  16. Image defects from surface and alignment errors in grazing incidence telescopes

    Science.gov (United States)

    Saha, Timo T.

    1989-01-01

    The rigid body motions and low frequency surface errors of grazing incidence Wolter telescopes are studied. The analysis is based on surface error descriptors proposed by Paul Glenn. In his analysis, the alignment and surface errors are expressed in terms of Legendre-Fourier polynomials. Individual terms in the expression correspond to rigid body motions (decenter and tilt) and low spatial frequency surface errors of mirrors. With the help of the Legendre-Fourier polynomials and the geometry of grazing incidence telescopes, exact and approximated first order equations are derived in this paper for the components of the ray intercepts at the image plane. These equations are then used to calculate the sensitivities of Wolter type I and II telescopes for the rigid body motions and surface deformations. The rms spot diameters calculated from this theory and OSAC ray tracing code agree very well. This theory also provides a tool to predict how rigid body motions and surface errors of the mirrors compensate each other.

  17. The epitaxial growth and interfacial strain study of VO{sub 2}/MgF{sub 2} (001) films by synchrotron based grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Fan, L.L. [Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051 (China); National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Chen, S. [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Liu, Q.H. [Science and Technology on Electro-optical Information Security Control Laboratory, Tianjin 300300 (China); Liao, G.M.; Chen, Y.L.; Ren, H. [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zou, C.W., E-mail: czou@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China)

    2016-09-05

    High quality VO{sub 2} films with different thickness were epitaxially grown on MgF{sub 2} (001) substrates by oxide molecular beam epitaxy method. The evolution of interfacial strain was investigated by synchrotron based grazing incidence X-ray diffraction. By adjusting the incidence angles, the penetration depth of X-ray in VO{sub 2} film could be controlled and the thickness-depend lattice distortion in the epitaxial VO{sub 2} film was investigated. Due to the lattice mismatching, the pronounced tensile strain was observed in ultra-thin VO{sub 2} film. As the film thickness increasing, the interfacial strain relaxed gradually and became fully relaxed for thick VO{sub 2} films. Combined with the electric transport measurement, it was revealed that the phase transition temperature of ultra-thin VO{sub 2} film decreased greatly. The effect of interfacial strain induced phase transition modulation and the intrinsic mechanism was systematically discussed. - Highlights: • We prepared high quality VO{sub 2} epitaxial films on MgF{sub 2} (001) substrates by oxide molecular beam epitaxy method. • Synchrotron radiation grazing incidence X-ray diffraction was employed to detect evolution of strain along depth profile. • Based on a classic band structure model, the mechanism of strain controlled phase transition of VO{sub 2} was discussed.

  18. Trapping mechanisms in scattering of beams at grazing incidence from crystals

    International Nuclear Information System (INIS)

    Smith, R.; O'Connor, D.J.; Felsobuki, E.I. von-Nagy

    1993-01-01

    The trajectories of grazing incidence, 1 keV beams of Si incident on Cu{111} are investigated by means of molecular dynamics (MD) simulations and the conditions under which atoms in the beam can be trapped in the surface binding potential are investigated. The binding potentials for the Cu-Si dimers are calculated using ab initio methods for the neutral, anion and cation. These calculations estimate the binding potential and equilibrium separation for the potential used for the MD calculations. It is found that at 4 o incidence to the Cu{111} face, no trapping occurs for a perfect crystal surface undergoing no thermal vibrations. Trapping can occur for the Si neutral if thermal vibrations are included in the model. Trapping is predicted to occur near steps on the Cu{111} face but these are fairly rare events for the Si - particles. (Author)

  19. Proteins on surfaces investigated by microbeam grazing incidence small angle X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gebhardt, Ronald; Riekel, Christian; Burghammer, Manfred [European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex (France); Vendrely, Charlotte [Universite de Cergy-Pontoise, ERRMECE, F-95000, Cergy-Pontoise (France); Mueller-Buschbaum, Peter [TU Muenchen, Physik Department E13, Muenchen (Germany)

    2009-07-01

    Grazing incidence small angle scattering with a 1 micron x-ray beam ({mu}GISAXS) is applied to study structural ordering of casein micelles and fibroin in solution cast films. {mu}GISAXS scans provide the possibility to locate highly ordered areas and to investigate variation in the molecular packing. In the case of the casein micelles, ordered film structures have been generated by decreasing their natural size dispersion. While dynamic light scattering was used to characterize the different size fractions in solution, {mu}GISAXS and roughness are measured on the resulting casein films. GISAXS-Patterns are analyzed by simulations providing the dimension and nearest neighbor distances of casein micelles. In the case of fibroin, ordering of nano-fibers formed during the drying process is investigated. The experimental data are analyzed by simulations and compared to SEM, AFM and Raman scattering experiments.

  20. Grazing incidence diffraction anomalous fine structure of self-assembled semiconductor nanostructures

    International Nuclear Information System (INIS)

    Grenier, S.; Letoublon, A.; Proietti, M.G.; Renevier, H.; Gonzalez, L.; Garcia, J.M.; Priester, C.; Garcia, J.

    2003-01-01

    We have studied self-organized quantum wires of InAs, grown by molecular beam epitaxy onto a InP(0 0 1) substrate, by means of grazing incidence diffraction anomalous fine structure (DAFS). The equivalent quantum wires thickness is 2.5 monolayers. We measured the (4 4 0) and (4 2 0) GIDAFS spectra, at the As K-edge, keeping the incidence and exit angles close to the InP critical angle. The analysis of both the smooth and oscillatory contributions of the DAFS spectrum, provide valuable information about composition and strain inside the quantum wires and close to the interface. We also show preliminary results on InAs wires encapsulated by a 40 A thick InP capping layer, suggesting the DAFS capability of probing different iso-strain regions of the wires

  1. Grazing incidence X-ray absorption characterization of amorphous Zn-Sn-O thin film

    Science.gov (United States)

    Moffitt, S. L.; Ma, Q.; Buchholz, D. B.; Chang, R. P. H.; Bedzyk, M. J.; Mason, T. O.

    2016-05-01

    We report a surface structure study of an amorphous Zn-Sn-O (a-ZTO) transparent conducting film using the grazing incidence X-ray absorption spectroscopy technique. By setting the measuring angles far below the critical angle at which the total external reflection occurs, the details of the surface structure of a film or bulk can be successfully accessed. The results show that unlike in the film where Zn is severely under coordinated (N < 4), it is fully coordinated (N = 4) near the surface while the coordination number around Sn is slightly smaller near the surface than in the film. Despite a 30% Zn doping, the local structure in the film is rutile-like.

  2. Crystallization behavior of polyethylene on silicon wafers in solution casting processes traced by time-resolved measurements of synchrotron grazing-incidence small-angle and wide-angle X-ray scattering

    International Nuclear Information System (INIS)

    Sasaki, S; Masunaga, H; Takata, M; Itou, K; Tashiro, K; Okuda, H; Takahara, A

    2009-01-01

    Crystallization behavior of polyethylene (PE) on silicon wafers in solution casting processes has been successfully traced by time-resolved grazing-incidence small-angle and wide-angle X-ray scattering (GISWAXS) measurements utilizing synchrotron radiation. A p-xylene solution of PE kept at ca. 343 K was dropped on a silicon wafer at ca. 298 K. While the p-xylene evaporated naturally from the dropped solution sample, PE chains crystallized to be a thin film. Raman spectral measurements were performed simultaneously with the GISWAXS measurements to evaluate quantitatively the p-xylene the dropped solution contained. Grazing-incidence wide-angle X-ray scattering (GIWAXS) patterns indicated nucleation and crystal growth in the dropped solution and the following as-cast film. GIWAXS and Raman spectral data revealed that crystallization of PE was enhanced after complete evaporation of the p-xylene from the dropped solution. The [110] and [200] directions of the orthorhombic PE crystal became relatively parallel to the wafer surface with time, which implied that the flat-on lamellae with respect to the wafer surface were mainly formed in the as-cast film. On the other hand, grazing-incidence small-angle X-ray scattering (GISAXS) patterns implied formation of isolated lamellae in the dropped solution. The lamellae and amorphous might alternatively be stacked in the preferred direction perpendicular to the wafer surface. The synchrotron GISWAXS experimental method could be applied for kinetic study on hierarchical structure of polymer thin films.

  3. First combined total reflection X-ray fluorescence and grazing incidence X-ray absorption spectroscopy characterization of aeolian dust archived in Antarctica and Alpine deep ice cores

    Energy Technology Data Exchange (ETDEWEB)

    Cibin, G. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon OX110DE (United Kingdom); IMONT/EIM, Ente Italiano della Montagna, P.za dei Caprettari 70, 00176 Roma (Italy); Universita' degli Studi di Roma Tre, Dipartimento di Scienze Geologiche, L.go S. Leonardo Murialdo 1, 00146 Roma (Italy)], E-mail: giannantonio.cibin@diamond.ac.uk; Marcelli, A. [INFN - Laboratori Nazionali di Frascati, P.O. Box 13, 00044 Frascati (Roma) (Italy); Maggi, V. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Sala, M. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Universita degli Studi di Milano, Dipartimento di Scienze della Terra ' A. Desio' , Sez. Mineralogia, Via Mangiagalli 34, 20133 Milano (Italy); Marino, F.; Delmonte, B. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Albani, S. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Universita degli Studi di Siena, Dottorato in Scienze Polari, via Laterina 8, 53100 Siena (Italy); Pignotti, S. [IMONT/EIM, Ente Italiano della Montagna, P.za dei Caprettari 70, 00176 Roma (Italy)

    2008-12-15

    Aeolian mineral dust archived in polar and mid latitude ice cores represents a precious proxy for assessing environmental and climatic variations at different timescales. In this respect, the identification of dust mineralogy plays a key role. In this work we performed the first preliminary X-ray absorption spectroscopy (XAS) experiments on mineral dust particles extracted from Antarctic and from Alpine firn cores using grazing incidence geometry at the Fe K-edge. A dedicated high vacuum experimental chamber was set up for normal-incidence and total-reflection X-Ray Fluorescence and Absorption Spectroscopy analyses on minor amounts of mineral materials at the Stanford Synchrotron Radiation Laboratory. Results show that this experimental technique and protocol allows recognizing iron inclusion mineral fraction on insoluble dust in the 1-10 {mu}g range.

  4. First combined total reflection X-ray fluorescence and grazing incidence X-ray absorption spectroscopy characterization of aeolian dust archived in Antarctica and Alpine deep ice cores

    International Nuclear Information System (INIS)

    Cibin, G.; Marcelli, A.; Maggi, V.; Sala, M.; Marino, F.; Delmonte, B.; Albani, S.; Pignotti, S.

    2008-01-01

    Aeolian mineral dust archived in polar and mid latitude ice cores represents a precious proxy for assessing environmental and climatic variations at different timescales. In this respect, the identification of dust mineralogy plays a key role. In this work we performed the first preliminary X-ray absorption spectroscopy (XAS) experiments on mineral dust particles extracted from Antarctic and from Alpine firn cores using grazing incidence geometry at the Fe K-edge. A dedicated high vacuum experimental chamber was set up for normal-incidence and total-reflection X-Ray Fluorescence and Absorption Spectroscopy analyses on minor amounts of mineral materials at the Stanford Synchrotron Radiation Laboratory. Results show that this experimental technique and protocol allows recognizing iron inclusion mineral fraction on insoluble dust in the 1-10 μg range

  5. Radiation effects in optical components

    International Nuclear Information System (INIS)

    Friebele, E.J.

    1987-01-01

    This report discusses components of high performance optical devices may be exposed to high energy radiation environments during their lifetime. The effect of these adverse environments depends upon a large number of parameters associated with the radiation (nature, energy, dose, dose rate, etc.) or the system (temperature, optical performance requirements, optical wavelength, optical power, path length, etc.), as well as the intrinsic susceptibility of the optical component itself to degradation

  6. Enhanced radiation resistant fiber optics

    International Nuclear Information System (INIS)

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

    1993-01-01

    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

  7. Enhanced radiation resistant fiber optics

    Science.gov (United States)

    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.

  8. Oxide surfaces and metal/oxide interfaces studied by grazing incidence X-ray scattering

    Science.gov (United States)

    Renaud, Gilles

    Experimental determinations of the atomic structure of insulating oxide surfaces and metal/oxide interfaces are scarce, because surface science techniques are often limited by the insulating character of the substrate. Grazing incidence X-ray scattering (GIXS), which is not subject to charge effects, can provide very precise information on the atomic structure of oxide surfaces: roughness, relaxation and reconstruction. It is also well adapted to analyze the atomic structure, the registry, the misfit relaxation, elastic or plastic, the growth mode and the morphology of metal/oxide interfaces during their growth, performed in situ. GIXS also allows the analysis of thin films and buried interfaces, in a non-destructive way, yielding the epitaxial relationships, and, by variation of the grazing incidence angle, the lattice parameter relaxation along the growth direction. On semi-coherent interfaces, the existence of an ordered network of interfacial misfit dislocations can be demonstrated, its Burger's vector determined, its ordering during in situ annealing cycles followed, and sometimes even its atomic structure can be addressed. Careful analysis during growth allows the modeling of the dislocation nucleation process. This review emphasizes the new information that GIXS can bring to oxide surfaces and metal/oxide interfaces by comparison with other surface science techniques. The principles of X-ray diffraction by surfaces and interfaces are recalled, together with the advantages and properties of grazing angles. The specific experimental requirements are discussed. Recent results are presented on the determination of the atomic structure of relaxed or reconstructed oxide surfaces. A description of results obtained during the in situ growth of metal on oxide surfaces is also given, as well as investigations of thick metal films on oxide surfaces, with lattice parameter misfit relaxed by an array of dislocations. Recent work performed on oxide thin films having

  9. Optical radiation and visual health

    International Nuclear Information System (INIS)

    Waxler, M.; Hitchins, V.M.

    1986-01-01

    This book provides a focus on the parameters of ultraviolet light, visible, and infrared radiation s which could cause long-term visual health problems in humans. It reviews early research on radiation effects on the eye, and gives detailed attention to the hazardous effects of optical radiation on the retinal pigment epithelium and the photoreceptors. These data are further analyzed with regard to five potential long-term visual health problems; retinal degeneration, visual aging, disorder of visual development, ocular drug phototoxicity, and cataracts. Finally, epidemiologic principles for studying the relationships between optical radiation and long-term visual health problems are reviewed, concluding with the implications for future research and radiation protection. The contents include: historical perspectives; optical radiation and cataracts; the involvement of the retinal pigment epithelium (RPE); optical radiation damage to the ocular photoreceptors; possible role of optical radiation in retinal degenerations; optical radiation and the aged eye; optical radiation effects on aging and visual perception; optical radiation effects on visual development; and index

  10. Dynamic grazing incidence fast atom diffraction during molecular beam epitaxial growth of GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, P., E-mail: atkinson@insp.jussieu.fr; Eddrief, M. [Sorbonne Universités, UPMC Univ. Paris 06, UMR 7588, INSP, F-75005 Paris (France); CNRS, UMR 7588, Institut des NanoSciences de Paris, 4 place Jussieu, F-75005 Paris (France); Etgens, V. H. [CNRS, UMR 7588, Institut des NanoSciences de Paris, 4 place Jussieu, F-75005 Paris (France); VeDeCom-Université Versailles Saint-Quentin en Yvelines, Versailles (France); Khemliche, H., E-mail: hocine.khemliche@u-psud.fr; Debiossac, M.; Mulier, M.; Lalmi, B.; Roncin, P. [ISMO UMR8214 CNRS-Université Paris-Sud, Orsay F-91400 (France); Momeni, A. [ISMO UMR8214 CNRS-Université Paris-Sud, Orsay F-91400 (France); Univ. Cergy Pontoise, F-95031 Cergy (France)

    2014-07-14

    A Grazing Incidence Fast Atom Diffraction (GIFAD) system has been mounted on a commercial molecular beam epitaxy chamber and used to monitor GaAs growth in real-time. In contrast to the conventionally used Reflection High Energy Electron Diffraction, all the GIFAD diffraction orders oscillate in phase, with the change in intensity related to diffuse scattering at step edges. We show that the scattered intensity integrated over the Laue circle is a robust method to monitor the periodic change in surface roughness during layer-by-layer growth, with oscillation phase and amplitude independent of incidence angle and crystal orientation. When there is a change in surface reconstruction at the start of growth, GIFAD intensity oscillations show that there is a corresponding delay in the onset of layer-by-layer growth. In addition, changes in the relative intensity of different diffraction orders have been observed during growth showing that GIFAD has the potential to provide insight into the preferential adatom attachment sites on the surface reconstruction during growth.

  11. Electron emission induced by resonant coherent interaction in ion-surface scattering at grazing incidence

    International Nuclear Information System (INIS)

    Garcia de Abajo, F.J.; Ponce, V.H.; Echenique, P.M.

    1994-01-01

    The resonant coherent interaction of an ion with an oriented crystal surface, under grazing-incidence conditions with respect to a special direction of the crystal, gives rise to electron loss to the continuum from electronic bound states of the ion. The calculations presented below predict large probabilities for electron emission due to this mechanism. The electrons are emitted with well defined energies, expressed in terms of the condition of resonance. Furthermore, the emission takes place around certain preferential directions, which are determined by both the latter condition and the symmetry of the surface lattice. Our calculations for MeV He + ions scattered at a W(001) surface along the left-angle 100 right-angle direction with glancing angle of 0--2 mrad indicate a yield of emission close to 1. Using heavier projectiles, one obtains smaller yields, but still large enough to be measurable in some cases (e.g., ∼0.9 for 53 MeV B 4+ and an angle of incidence of 1 mrad). Besides, the initial bound state is energy shifted due to the interaction with both the crystal potential and the velocity-dependent image potential. This results in a slight shift of the peaks of emission, which suggests a possible spectroscopy for analyzing the dynamical interaction of electronic bound states with solid surfaces

  12. HEKATE—A novel grazing incidence neutron scattering concept for the European Spallation Source

    Science.gov (United States)

    Glavic, Artur; Stahn, Jochen

    2018-03-01

    Structure and magnetism at surfaces and buried interfaces on the nanoscale can only be accessed by few techniques, one of which is grazing incidence neutron scattering. While the technique has its strongest limitation in a low signal and large background, due to the low scattering probability and need for high resolution, it can be expected that the high intensity of the European Spallation Source in Lund, Sweden, will make many more such studies possible, warranting a dedicated beamline for this technique. We present an instrument concept, Highly Extended K range And Tunable Experiment (HEKATE), for surface scattering that combines the advantages of two Selene neutron guides with unique capabilities of spatially separated distinct wavelength frames. With this combination, it is not only possible to measure large specular reflectometry ranges, even on free liquid surfaces, but also to use two independent incident beams with tunable sizes and resolutions that can be optimized for the specifics of the investigated samples. Further the instrument guide geometry is tuned for reduction of high energy particle background and only uses low to moderate supermirror coatings for high reliability and affordable cost.

  13. HEKATE-A novel grazing incidence neutron scattering concept for the European Spallation Source.

    Science.gov (United States)

    Glavic, Artur; Stahn, Jochen

    2018-03-01

    Structure and magnetism at surfaces and buried interfaces on the nanoscale can only be accessed by few techniques, one of which is grazing incidence neutron scattering. While the technique has its strongest limitation in a low signal and large background, due to the low scattering probability and need for high resolution, it can be expected that the high intensity of the European Spallation Source in Lund, Sweden, will make many more such studies possible, warranting a dedicated beamline for this technique. We present an instrument concept, Highly Extended K range And Tunable Experiment (HEKATE), for surface scattering that combines the advantages of two Selene neutron guides with unique capabilities of spatially separated distinct wavelength frames. With this combination, it is not only possible to measure large specular reflectometry ranges, even on free liquid surfaces, but also to use two independent incident beams with tunable sizes and resolutions that can be optimized for the specifics of the investigated samples. Further the instrument guide geometry is tuned for reduction of high energy particle background and only uses low to moderate supermirror coatings for high reliability and affordable cost.

  14. Some simple ideas on x-ray reflection and grazing-incidence diffraction from thin surfactant films

    DEFF Research Database (Denmark)

    Kjær, K.

    1994-01-01

    For Langmuir films of long linear amphiphilic molecules at the air-water interface, grazing-incidence diffraction data resolved in terms of both the horizontal and vertical components of the scattering angle can be evaluated to a fair level of detail by means of a slide rule. Specular reflection ...... data require more sophisticated means although some rules of thumb can be formulated.......For Langmuir films of long linear amphiphilic molecules at the air-water interface, grazing-incidence diffraction data resolved in terms of both the horizontal and vertical components of the scattering angle can be evaluated to a fair level of detail by means of a slide rule. Specular reflection...

  15. Surface damage through grazing incidence ions investigated by scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Redinger, Alex

    2009-01-01

    Surface damage, caused by grazing incidence ions, is investigated with variable temperature scanning tunneling microscopy. The experiments are carried out on a Pt(111) crystal. The kinetic energy of noble gas ions is varied between 1-15 keV and the angle of incidence can be adjusted between θ = 78.5 and θ = 90 measured with respect to the surface normal. The damage patterns of single ion impacts, on flat terraces and at step edges of monoatomic height, are investigated at low surface temperatures. Ions hitting a flat terrace are usually specular reflected. The energy transfer from the ion to the crystal atoms is small and only little damage is produced. In contrast, at ascending step edges, which are illuminated by the ion beam, large angle scattering events occur. Sputtering, adatom and vacancy production is induced. However, a significant fraction of the ions, which hit step edges, enter the crystal and are guided in between two atomic layers parallel to the surface via small angle binary collisions. This steering process is denoted as subsurface channeling. The energy loss per length scale of the channeled particles is low, which results in long ion trajectories (up to 1000A). During the steering process, the ions produce surface damage. Depending on the ion species and the ion energy, adatom and vacancies or surface vacancy trenches of monoatomic width are observed. The surface damage can be used to track the path of the ion. This makes the whole trajectory of single ions with keV energy visible. The number of sputtered atoms per incident ion at ascending step edges, i.e. the step edge sputtering yield, is measured experimentally for different irradiation conditions. For θ = 86 , the sputtering yield is determined from the fluence dependent retraction of pre-existing illuminated step edges. An alternative method for the step edge sputtering yield determination, is the analysis of the concentration of ascending steps and of the removed amount of material as a

  16. Surface damage through grazing incidence ions investigated by scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Redinger, Alex

    2009-07-10

    Surface damage, caused by grazing incidence ions, is investigated with variable temperature scanning tunneling microscopy. The experiments are carried out on a Pt(111) crystal. The kinetic energy of noble gas ions is varied between 1-15 keV and the angle of incidence can be adjusted between {theta} = 78.5 and {theta} = 90 measured with respect to the surface normal. The damage patterns of single ion impacts, on flat terraces and at step edges of monoatomic height, are investigated at low surface temperatures. Ions hitting a flat terrace are usually specular reflected. The energy transfer from the ion to the crystal atoms is small and only little damage is produced. In contrast, at ascending step edges, which are illuminated by the ion beam, large angle scattering events occur. Sputtering, adatom and vacancy production is induced. However, a significant fraction of the ions, which hit step edges, enter the crystal and are guided in between two atomic layers parallel to the surface via small angle binary collisions. This steering process is denoted as subsurface channeling. The energy loss per length scale of the channeled particles is low, which results in long ion trajectories (up to 1000A). During the steering process, the ions produce surface damage. Depending on the ion species and the ion energy, adatom and vacancies or surface vacancy trenches of monoatomic width are observed. The surface damage can be used to track the path of the ion. This makes the whole trajectory of single ions with keV energy visible. The number of sputtered atoms per incident ion at ascending step edges, i.e. the step edge sputtering yield, is measured experimentally for different irradiation conditions. For {theta} = 86 , the sputtering yield is determined from the fluence dependent retraction of pre-existing illuminated step edges. An alternative method for the step edge sputtering yield determination, is the analysis of the concentration of ascending steps and of the removed amount

  17. Radiation damage in optical fibers

    International Nuclear Information System (INIS)

    Lyons, P.B.; Looney, L.D.; Ogle, J.W.

    1983-01-01

    Optical fibers provide important advantages over coaxial cables for many data transmission applications. Some of these applications require that the fibers transmit data during a radiation pulse. Other applications utilize the fiber as a radiation-to-light transducer. In either case, radiation-induced luminescence and absorption must be understood. Most studies of radiation effects in fibers have emphasized time scales of interest in telecommunication systems, from the msec to hour range. Few studies have concentrated on response at times below 1 + s. At Los Alamos, both laboratory electron accelerators and nuclear tests have been used as radiation sources to probe this early time region. The use of a fiber (or any optical medium) as a Cerenkov radiation-to-light transducer is discussed. Since the radiation induces attenuation in the medium, the light output is not proportional to the radiation input. The nonlinearity introduced by this attenuation is calculated

  18. Numerical controlled diamond fly cutting machine for grazing incidence X-ray reflection mirrors

    International Nuclear Information System (INIS)

    Uchida, Fumihiko; Moriyama, Shigeo; Seya, Eiiti

    1992-01-01

    Synchrotron radiation has reached the stage of practical use, and the application to the wide fields that support future advanced technologies such as spectroscopy, the structural analysis of matters, semiconductor lithography and medical light source is expected. For the optical system of the equipment utilizing synchrotron radiation, the total reflection mirrors of oblique incidence are used for collimating and collecting X-ray. In order to restrain their optical aberration, nonspherical shape is required, and as the manufacturing method with high precision for nonspherical mirrors, a numerically controlled diamond cutting machine was developed. As for the cutting of soft metals with diamond tools, the high precision machining of any form can be done by numerical control, the machining time can be reduced as compared with grinding, and the cooling effect is large in metals. The construction of the cutting machine, the principle of machining, the control system, the method of calculating numerical control data, the investigation of machinable forms and the result of evaluation are reported. (K.I.)

  19. On the determination of stress profiles in expanded austenite by grazing incidence X-ray diffraction and successive layer removal

    DEFF Research Database (Denmark)

    Fernandes, Frederico Augusto Pires; Christiansen, Thomas L.; Winther, Grethe

    2015-01-01

    Surface layers of expanded austenite resulting from nitriding typically exhibit large gradients in residual stress and composition. Evaluation of residual-stress profiles is explored by means of grazing incidence X-ray diffraction (GI-XRD), probing shallow depths, combined with successive layer...... removal. Several factors complicating the stress determination are analysed and discussed: (1) ghost stresses arising from a small variation in the shallow information depths probed with GI-XRD, (2) selection of the grain interaction model used to calculate the X-ray elastic constants for conversion...

  20. Measuring helium bubble diameter distributions in tungsten with grazing incidence small angle x-ray scattering (GISAXS)

    Science.gov (United States)

    Thompson, M.; Kluth, P.; Doerner, R. P.; Kirby, N.; Riley, D.; Corr, C. S.

    2016-02-01

    Grazing incidence small angle x-ray scattering was performed on tungsten samples exposed to helium plasma in the MAGPIE and Pisces-A linear plasma devices to measure the size distributions of resulting helium nano-bubbles. Nano-bubbles were fitted assuming spheroidal particles and an exponential diameter distribution. These particles had mean diameters between 0.36 and 0.62 nm. Pisces-A exposed samples showed more complex patterns, which may suggest the formation of faceted nano-bubbles or nano-scale surface structures.

  1. On the determination of stress profiles in expanded austenite by grazing incidence X-ray diffraction and successive layer removal

    International Nuclear Information System (INIS)

    Fernandes, Frederico A.P.; Christiansen, Thomas L.; Winther, Grethe; Somers, Marcel A.J.

    2015-01-01

    Surface layers of expanded austenite resulting from nitriding typically exhibit large gradients in residual stress and composition. Evaluation of residual-stress profiles is explored by means of grazing incidence X-ray diffraction (GI-XRD), probing shallow depths, combined with successive layer removal. Several factors complicating the stress determination are analysed and discussed: (1) ghost stresses arising from a small variation in the shallow information depths probed with GI-XRD, (2) selection of the grain interaction model used to calculate the X-ray elastic constants for conversion of lattice strains into residual stress and (3) the composition dependence of these elastic constants

  2. Single mode operation in a pulsed Ti:sapphire laser oscillator with a grazing-incidence four-mirror cavity

    CERN Document Server

    Ko, D K; Binks, D J; Gloster, L A W; King, T A

    1998-01-01

    We demonstrate stable single mode operation in a pulsed Ti:sapphire laser oscillator with a novel grazing-incidence four-mirror coupled cavity. This cavity consists of a grating, a gain medium, and four mirrors and, therefore, has a four-arm interferometer configuration. Through the interferometric effect, we could suppress the adjacent modes and obtain stable single mode operation with a bandwidth of < 200 MHz. We also have developed a general analysis of the laser modes and the threshold conditions for configuration and the experimental results agree well with the theoretical predictions.

  3. Survey of surface roughness properties of synchrotron radiation optics

    International Nuclear Information System (INIS)

    Takacs, P.Z.; Colbert, J.; Church, E.L.

    1986-03-01

    Measurements of surface roughness were made on a large number of grazing incidence mirrors delivered for use at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The measurements were made with a WYKO optical profiler using a 2.5X and a 10X objective and analyzed with our PROFILE code to generate an average periodogram representation for each surface. The data is presented in the form of representative profiles with all of the periodogram curves arranged according to figure type. Analysis of the periodograms allows one to compute bandwidth-limited values for RMS roughness and slope, to provide valuable feedback information to manufacturers regarding compliance with specifications, and to predict the performance of the optic at x-ray wavelengths

  4. In situ x-ray reflectivity and grazing incidence x-ray diffraction study of L 1{sub 0} ordering in {sup 57}Fe/Pt multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Raghavendra Reddy, V; Gupta, Ajay; Gome, Anil [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore-452 017 (India); Leitenberger, Wolfram [Institute of Physics, University of Potsdam, 14469 Potsdam (Germany); Pietsch, U [Physics Department, University of Siegen, D-57068 Siegen (Germany)], E-mail: vrreddy@csr.ernet.in, E-mail: varimalla@yahoo.com

    2009-05-06

    In situ high temperature x-ray reflectivity and grazing incidence x-ray diffraction measurements in the energy dispersive mode are used to study the ordered face-centered tetragonal (fct) L 1{sub 0} phase formation in [Fe(19 A)/Pt(25 A)]{sub x 10} multilayers prepared by ion beam sputtering. With the in situ x-ray measurements it is observed that (i) the multilayer structure first transforms to a disordered FePt and subsequently to an ordered fct L 1{sub 0} phase, (ii) the ordered fct L 1{sub 0} FePt peaks start to appear at 320 deg. C annealing, (iii) the activation energy of the interdiffusion is 0.8 eV and (iv) ordered fct FePt grains have preferential out-of-plane texture. The magneto-optical Kerr effect and conversion electron Moessbauer spectroscopies are used to study the magnetic properties of the as-deposited and 400 deg. C annealed multilayers. The magnetic data for the 400 {sup 0}C annealed sample indicate that the magnetization is at an angle of {approx}50 deg. from the plane of the film.

  5. High-resolution grazing-incidence grating spectrometer for temperature measurements of low-Z ions emitting in the 100-300 Å spectral banda)

    Science.gov (United States)

    Widmann, K.; Beiersdorfer, P.; Magee, E. W.; Boyle, D. P.; Kaita, R.; Majeski, R.

    2014-11-01

    We have constructed a high-resolution grazing-incidence spectrometer designed for measuring the ion temperature of low-Z elements, such as Li+ or Li2 +, which radiate near 199 Å and 135 Å, respectively. Based on measurements at the Livermore Electron Beam Ion Trap we have shown that the instrumental resolution is better than 48 mÅ at the 200 Å setting and better than 40 mÅ for the 135-Å range. Such a high spectral resolution corresponds to an instrumental limit for line-width based temperature measurements of about 45 eV for the 199 Å Li+ and 65 eV for the 135 Å Li2 + lines. Recently obtained survey spectra from the Lithium Tokamak Experiment at the Princeton Plasma Physics Laboratory show the presence of these lithium emission lines and the expected core ion temperature of approximately 70 eV is sufficiently high to demonstrate the feasibility of utilizing our high-resolution spectrometer as an ion-temperature diagnostic.

  6. High-resolution grazing-incidence grating spectrometer for temperature measurements of low-Z ions emitting in the 100–300 Å spectral band

    Energy Technology Data Exchange (ETDEWEB)

    Widmann, K., E-mail: widmann1@llnl.gov; Beiersdorfer, P.; Magee, E. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Boyle, D. P.; Kaita, R.; Majeski, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2014-11-15

    We have constructed a high-resolution grazing-incidence spectrometer designed for measuring the ion temperature of low-Z elements, such as Li{sup +} or Li{sup 2+}, which radiate near 199 Å and 135 Å, respectively. Based on measurements at the Livermore Electron Beam Ion Trap we have shown that the instrumental resolution is better than 48 mÅ at the 200 Å setting and better than 40 mÅ for the 135-Å range. Such a high spectral resolution corresponds to an instrumental limit for line-width based temperature measurements of about 45 eV for the 199 Å Li{sup +} and 65 eV for the 135 Å Li{sup 2+} lines. Recently obtained survey spectra from the Lithium Tokamak Experiment at the Princeton Plasma Physics Laboratory show the presence of these lithium emission lines and the expected core ion temperature of approximately 70 eV is sufficiently high to demonstrate the feasibility of utilizing our high-resolution spectrometer as an ion-temperature diagnostic.

  7. A flow cell for transient voltammetry and in situ grazing incidence X-ray diffraction characterization of electrocrystallized cadmium(II) tetracyanoquinodimethane

    Energy Technology Data Exchange (ETDEWEB)

    Veder, Jean-Pierre [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Nafady, Ayman [School of Chemistry, Monash University, Clayton, Victoria 3800 (Australia); Clarke, Graeme [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Williams, Ross P. [Centre for Materials Research, Department of Imaging and Applied Physics, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); De Marco, Roland, E-mail: r.demarco@curtin.edu.a [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Bond, Alan M. [School of Chemistry, Monash University, Clayton, Victoria 3800 (Australia)

    2011-01-01

    An easy to fabricate and versatile cell that can be used with a variety of electrochemical techniques, also meeting the stringent requirement for undertaking cyclic voltammetry under transient conditions in in situ electrocrystallization studies and total external reflection X-ray analysis, has been developed. Application is demonstrated through an in situ synchrotron radiation-grazing incidence X-ray diffraction (SR-GIXRD) characterization of electrocrystallized cadmium (II)-tetracyanoquinodimethane material, Cd(TCNQ){sub 2}, from acetonitrile (0.1 mol dm{sup -3} [NBu{sub 4}][PF{sub 6}]). Importantly, this versatile cell design makes SR-GIXRD suitable for almost any combination of total external reflection X-ray analysis (e.g., GIXRF and GIXRD) and electrochemical perturbation, also allowing its application in acidic, basic, aqueous, non-aqueous, low and high flow pressure conditions. Nevertheless, the cell design separates the functions of transient voltammetry and SR-GIXRD measurements, viz., voltammetry is performed at high flow rates with a substantially distended window to minimize the IR (Ohmic) drop of the electrolyte, while SR-GIXRD is undertaken using stop-flow conditions with a very thin layer of electrolyte to minimize X-ray absorption and scattering by the solution.

  8. Grazing incidence synchrotron X-ray diffraction of marbles consolidated with diammonium hydrogen phosphate treatments: non-destructive probing of buried minerals

    Science.gov (United States)

    Possenti, Elena; Colombo, Chiara; Conti, Claudia; Gigli, Lara; Merlini, Marco; Plaisier, Jasper Rikkert; Realini, Marco; Gatta, G. Diego

    2018-05-01

    Diammonium hydrogen phosphate (DAP)-based consolidating treatments react with carbonatic stones and form calcium phosphates phases, whose composition depends on the availability of free calcium ions. In this work, an innovative non-destructive approach based on grazing incidence X-ray diffraction (GIXRD) with synchrotron radiation (SR) is used to investigate DAP-treated Carrara marble specimens and to study the influence of the substrate composition on the crystallization of calcium phosphate phases. The outcomes indicate that the presence of compositional micro-heterogeneity of Carrara marble favours the formation of specific phases. Dicalcium phosphate dihydrate, a calcium phosphate with a low Ca/P molar ratio, is formed on carbonatic phases with a low Ca amount, such as dolomite grains and Mg-containing veins. Furthermore, this study highlights the potentialities of SR-GIXRD as a powerful non-destructive tool for the diagnostic of Cultural Heritage objects since it allows investigating the conservation history of stone materials and their interaction with the environment.

  9. A new spectrometer for grazing incidence X-ray fluorescence for the characterization of Arsenic implants and Hf based high-k layers

    International Nuclear Information System (INIS)

    Ingerle, D.; Meirer, F.; Zoeger, N.; Pepponi, G.; Giubertoni, D.; Steinhauser, G.; Wobrauschek, P.; Streli, C.

    2010-01-01

    Grazing Incidence X-ray Fluorescence Analysis (GIXRF) is a powerful technique for depth-profiling and characterization of thin layers in depths up to a few hundred nanometers. By measurement of fluorescence signals at various incidence angles Grazing Incidence X-ray Fluorescence Analysis provides information on depth distribution and total dose of the elements in the layers. The technique is very sensitive even in depths of a few nanometers. As Grazing Incidence X-ray Fluorescence Analysis does not provide unambigous depth profile information and needs a realistic input depth profile for fitting, in the context of the EC funded European Integrated Activity of Excellence and Networking for Nano and Micro-Electronics Analysis (ANNA) Grazing Incidence X-ray Fluorescence Analysis is used as a complementary technique to Secondary Ion Mass Spectrometry (SIMS) for the characterization of Ultra Shallow Junctions (USJ). A measuring chamber was designed, constructed and tested to meet the requirements of Grazing Incidence X-ray Fluorescence Analysis. A measurement protocol was developed and tested. Some results for As implants as well as Hf based high k layers on Silicon are shown. For the determination of the bulk As content of the wafers, Instrumental Neutron Activation Analysis has also been applied for comparison.

  10. Method of lightening radiation darkened optical elements

    International Nuclear Information System (INIS)

    Reich, F.R.; Schwankoff, A.R.

    1980-01-01

    A method of lightening a radiation-darkened optical element in which visible optical energy or electromagnetic radiation having a wavelength in the range of from about 2000 to about 20,000 angstroms is directed into the radiation-darkened optical element; the method may be used to lighten radiation-darkened optical element in-situ during the use of the optical element to transmit data by electronically separating the optical energy from the optical output by frequency filtering, data cooling, or interlacing the optic energy between data intervals

  11. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

    DEFF Research Database (Denmark)

    Kehres, Jan; Pedersen, Thomas; Masini, Federico

    2016-01-01

    at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles.......The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing......-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments...

  12. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

    Science.gov (United States)

    Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole

    2016-01-01

    The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles. PMID:26917133

  13. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering.

    Science.gov (United States)

    Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole; Chorkendorff, Ib

    2016-03-01

    The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles.

  14. Structure of a monolayer of molecular rotors on aqueous subphase from grazing-incidence X-ray diffraction.

    Science.gov (United States)

    Kaleta, Jiří; Wen, Jin; Magnera, Thomas F; Dron, Paul I; Zhu, Chenhui; Michl, Josef

    2018-03-23

    In situ grazing-incidence X-ray scattering shows that a monolayer of artificial rod-shaped dipolar molecular rotors produced on the surface of an aqueous subphase in a Langmuir trough has a structure conducive to a 2D ferroelectric phase. The axes of the rotors stand an average of 0.83 nm apart in a triangular grid, perpendicular to the surface within experimental error. They carry 2,3-dichlorophenylene rotators near rod centers, between two decks of interlocked triptycenes installed axially on the rotor axle. The analysis is based first on simultaneous fitting of observed Bragg rods and second on fitting the reflectivity curve with only three adjustable parameters and the calculated rotor electron density, which also revealed the presence of about seven molecules of water near each rotator. Dependent on preparation conditions, a minor and variable amount of a different crystal phase may also be present in the monolayer.

  15. In situ grazing incidence small-angle X-ray scattering investigation of polystyrene nanoparticle spray deposition onto silicon.

    Science.gov (United States)

    Herzog, Gerd; Benecke, Gunthard; Buffet, Adeline; Heidmann, Berit; Perlich, Jan; Risch, Johannes F H; Santoro, Gonzalo; Schwartzkopf, Matthias; Yu, Shun; Wurth, Wilfried; Roth, Stephan V

    2013-09-10

    We investigated the spray deposition and subsequent self-assembly during drying of a polystyrene nanoparticle dispersion with in situ grazing incidence small-angle X-ray scattering at high time resolution. During the fast deposition of the dispersion and the subsequent evaporation of the solvent, different transient stages of nanoparticle assembly can be identified. In the first stage, the solvent starts to evaporate without ordering of the nanoparticles. During the second stage, large-scale structures imposed by the breakup of the liquid film are observable. In this stage, the solvent evaporates further and nanoparticle ordering starts. In the late third drying stage, the nanoparticles self-assemble into the final layer structure.

  16. Study of the in-plane magnetic structure of a layered system using polarized neutron scattering under grazing incidence geometry

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, R., E-mail: ryuji.maruyama@j-parc.jp [J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Ibaraki 319-1195 (Japan); Bigault, T.; Wildes, A.R.; Dewhurst, C.D. [Institut Laue Langevin, 71 avenue des Martyrs, 38042 Grenoble (France); Soyama, K. [J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Ibaraki 319-1195 (Japan); Courtois, P. [Institut Laue Langevin, 71 avenue des Martyrs, 38042 Grenoble (France)

    2016-05-21

    The in-plane magnetic structure of a layered system with a polycrystalline grain size less than the ferromagnetic exchange length was investigated using polarized neutron off-specular scattering and grazing incidence small angle scattering measurements to gain insight into the mechanism that controls the magnetic properties which are different from the bulk. These complementary measurements with different length scales and the data analysis based on the distorted wave Born approximation revealed the lateral correlation on a length scale of sub- μm due to the fluctuating orientation of the magnetization in the layer. The obtained in-plane magnetic structure is consistent with the random anisotropy model, i.e. competition between the exchange interactions between neighboring spins and the local magnetocrystalline anisotropy.

  17. Reflective optics

    CERN Document Server

    Korsch, Dietrich

    1991-01-01

    This is the first book dedicated exclusively to all-reflective imaging systems. It is a teaching tool as well as a practical design tool for anyone who specializes in optics, particularly for those interested in telescopes, infrared, and grazing-incidence systems. The first part of the book describes a unified geometric optical theory of all-reflective imaging systems (from near-normal to grazing incidence) developed from basic principles. The second part discusses correction methods and a multitude of closed-form solutions of well-corrected systems, supplemented with many conventional and unc

  18. Test facility for astronomical x-ray optics

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Lewis, Robert A.; Bordas, J.

    1990-01-01

    Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earth's atmosphere. These devices require a large collection aperture and the imaging of an x-ray source that is essentially placed at infinity. The ideal testing system for these optical elements has to appro......Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earth's atmosphere. These devices require a large collection aperture and the imaging of an x-ray source that is essentially placed at infinity. The ideal testing system for these optical elements has...... to approximate that encountered under working conditions; however, the testing of these optical elements is notoriously difficult with conventional x-ray generators. Synchrotron radiation (SR) sources are sufficiently brilliant to produce a nearly perfect parallel beam over a large area while still retaining...... a flux considerably higher than that available from conventional x-ray generators. A facility designed for the testing of x-ray optics, particularly in connection with x-ray telescopes, is described. It is proposed that this facility will be accommodated at the Synchrotron Radiation Source...

  19. Capillary optics for radiation focusing

    International Nuclear Information System (INIS)

    Peurrung, A.J.; Reeder, P.L.; Bliss, M.; Craig, R.A.; Lepel, E.A.; Stromswold, D.C.; Stoffels, J.; Sunberg, D.S.; Tenny, H.

    1996-11-01

    Capillary lens technology may ultimately bring benefits to neutron and x-ray-based science like conventional lenses with visible light. Although the technology is not yet 10 years old, these lenses have already had a significant impact in engineering, science, and medicine. Capillary lenses are advantageous when it is desirable to increase the radiation flux at a location without regard to its angular divergence. PNNL has worked to improve the technology in several ways. A single, optimally tapered capillary was manufactured, which allows intensity gains of a factor of 270 for an initially parallel, incident x-ray beam. Feasibility of constructing neutron lenses using 58 Ni (particularly effective at reflecting neutrons) has been explored. Three applications for capillary optics have been identified and studied: neutron telescope, Gandolphi x-ray diffractometry, and neutron radiotherapy. A brief guide is given for determining which potential applications are likely to be helped by capillary optics

  20. Metrology and Alignment of Light Weight Grazing Incidence X-Ray Mirrors

    Science.gov (United States)

    Zhang, William; Content, David; Petre, Robert; Saha, Timo

    2000-01-01

    Metrology and alignment of light weight X-ray optics have been a challenge for two reasons: (1) that the intrinsic mirror quality and distortions caused by handling can not be easily separated, and (2) the diffraction limits of the visible light become a severe problem at the order of one arc-minute. Traditional methods of using a normal incident pencil or small parallel beam which monitors a tiny fraction of the mirror in question at a given time can not adequately monitor those distortions. We are developing a normal incidence setup that monitors a large fraction, if not the whole, of the mirror at any given time. It will allow us to align thin X-ray mirrors to-an accuracy of a few arc seconds or to a limit dominated by the mirror intrinsic quality.

  1. Angle resolved electron spectroscopy of spontaneous ionization processes occurring in doubly charged ion-surface collisions at grazing incidence

    International Nuclear Information System (INIS)

    Wouters, P.A.A.F.; Emmichoven, P.A.Z. van; Niehaus, A.

    1989-01-01

    The experimental setup used to measure electron spectra at well defined detection angles for grazing incidence doubly charged ion-surface collisions at keV-energies is described. Electron spectra are reported for the rare gas ions colliding with a Cu(110)-surface. The spectra are analyzed in terms of various spontaneous ionization processes using a newly developed model. It is found that double capture followed by atomic auto-ionization on the incoming trajectory and Auger-capture processes in which the first and second hole in the doubly charged projectiles are successively filled are the main processes contributing to the electron spectra. From a comparison of model calculations with measured spectra it is concluded that the metal electrons cannot adapt adiabatically to the sudden changes of the charge state of the projectile in front of the surface. A parameter characterizing the partly diabatic behavior is determined. The variation of spectra upon adsorption of a monolayer of oxygen on the surface is reported and discussed. (author)

  2. A Grazing-Incidence Small-Angle X-Ray Scattering View of Vertically Aligned ZnO Nano wires

    International Nuclear Information System (INIS)

    Lavcevic, M.L.; Silovic, L.; Dubcek, P.; Pavlovic, M.; Bernstorff, S.

    2013-01-01

    We report a grazing-incidence small-angle X-ray scattering study of ZnO films with vertically aligned and randomly distributed nano wires, grown through a hydrothermal growth process on nano structured ZnO seeding coatings and deposited by electron beam evaporation on silicon and glass, respectively. The comparison of the scattering patterns of seeding coatings and nano wires showed that the scattering of vertically aligned nano wires exhibited a specific feature: the dominant characteristic of their scattering patterns is the appearance of fine structure effects around the specular peak. These effects were clarified by the combined reflection and scattering phenomena, suggested for the aligned nano wires-substrate system. Furthermore, they enabled the calculation of the average gyration radius of nano wires in horizontal direction. The calculated value was in good agreement with the radii of nano wires estimated by surface electron microscopy. Therefore, the observed feature in the scattering pattern can serve as evidence of the aligned growth of nano wires.

  3. Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics

    Science.gov (United States)

    Tracy, Cameron L.; Chen, Chien-Hung; Park, Sulgiye; Davisson, M. Lee; Ewing, Rodney C.

    2018-04-01

    Nuclear forensics involves determination of the origin and history of interdicted nuclear materials based on the detection of signatures associated with their production and trafficking. The surface oxidation undergone by UO2 when exposed to air is a potential signature of its atmospheric exposure during handling and transport. To assess the sensitivity of this oxidation to atmospheric parameters, surface sensitive grazing-incidence x-ray diffraction (GIXRD) measurements were performed on UO2 samples exposed to air of varying relative humidity (34%, 56%, and 95% RH) and temperature (room temperature, 50 °C, and 100 °C). Near-surface unit cell contraction was observed following exposure, indicating oxidation of the surface and accompanying reduction of the uranium cation ionic radii. The extent of unit cell contraction provides a measure of the extent of oxidation, allowing for comparison of the effects of various exposure conditions. No clear influence of relative humidity on the extent of oxidation was observed, with samples exhibiting similar degrees of unit cell contraction at all relative humidities investigated. In contrast, the thickness of the oxidized layers increased substantially with increasing temperature, such that differences on the order of 10 °C yielded readily observable crystallographic signatures of the exposure conditions.

  4. Grazing exit versus grazing incidence geometry for x-ray absorption near edge structure analysis of arsenic traces

    International Nuclear Information System (INIS)

    Meirer, F.; Streli, C.; Wobrauschek, P.; Zoeger, N.; Pepponi, G.

    2009-01-01

    In the presented study the grazing exit x-ray fluorescence was tested for its applicability to x-ray absorption near edge structure analysis of arsenic in droplet samples. The experimental results have been compared to the findings of former analyses of the same samples using a grazing incidence (GI) setup to compare the performance of both geometries. Furthermore, the investigations were accomplished to gain a better understanding of the so called self-absorption effect, which was observed and investigated in previous studies using a GI geometry. It was suggested that a normal incidence-grazing-exit geometry would not suffer from self-absorption effects in x-ray absorption fine structure (XAFS) analysis due to the minimized path length of the incident beam through the sample. The results proved this assumption and in turn confirmed the occurrence of the self-absorption effect for GI geometry. Due to its lower sensitivity it is difficult to apply the GE geometry to XAFS analysis of trace amounts (few nanograms) of samples but the technique is well suited for the analysis of small amounts of concentrated samples

  5. An in situ grazing incidence x-ray scattering study of block copolymer thin films during solvent vapor annealing

    Science.gov (United States)

    Gu, Xiaodan; Gunkel, Ilja; Hexemer, Alexander; Russell, Thomas

    2014-03-01

    Although solvent vapor annealing (SVA) has been widely applied to block copolymer (BCP) thin films to obtain well-ordered microdomains, the mechanism of enhancing lateral order is not well understood. Here, we used real time in situ grazing-incidence small-angle x-ray scattering (in situGISAXS) to study the self-assembly of PS-b-P2VP BCP BCPs with different molecular weights thin films in THF vapor, a near neutral solvent for both blocks. Both swelling and deswelling behavior of BCP thin films were examined. The extent of swellingand the solvent removal rate not only affect the domain spacing of BCPs but also dictate the extent of lateral ordering of the BCP microdomains. Larger grains were observed at higher values of the swelling ratio (close to disordering). To preserve the maximal lateral ordering of the microdomains in the swollen state, the fastest solvent removal rate is required to freeze in the ordered microdomain structure of the swollen BCP film. We thanks support from U.S. Department of Energy BES under contract BES-DE-FG02-96ER45612 and ALS doctoral fellowship.

  6. UltraForm Finisher Optical Mandrel Fabrication, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The requirements for cost effective manufacturing and metrology of normal incidence and grazing incidence X-Ray optical surfaces is instrumental for the success of...

  7. Structural stability of naphthyl end-capped oligothiophenes in organic field-effect transistors measured by grazing-incidence X-ray diffraction in operando

    DEFF Research Database (Denmark)

    Huss-Hansen, Mathias K.; Lauritzen, Andreas E.; Bikondoa, Oier

    2017-01-01

    We report on microstructural durability of 5,5′-bis(naphth-2-yl)-2,2′-bithiophene (NaT2) in organic field-effect transistors (OFETs) in operando monitored by grazing-incidence X-ray diffraction (GIXRD). NaT2 maintains its monoclinic bulk motif in operating OFETs with a=20.31±0.06 Å, b=6.00±0.01 Å...

  8. Radiation cured coatings for fiber optics

    International Nuclear Information System (INIS)

    Ketley, A.D.; Morgan, C.R.

    1978-01-01

    A continuous protective coating is formed on a fiber optic by coating the fiber optic in a bath of a liquid radiation curable composition at a temperature up to 90 0 C and exposing the coated conductor to ultraviolet or high energy ionizing radiation to cure the coating

  9. Magnetic resonance imaging of radiation optic neuropathy

    International Nuclear Information System (INIS)

    Zimmerman, C.F.; Schatz, N.J.; Glaser, J.S.

    1990-01-01

    Three patients with delayed radiation optic neuropathy after radiation therapy for parasellar neoplasms underwent magnetic resonance imaging. The affected optic nerves and chiasms showed enlargement and focal gadopentetate dimeglumine enhancement. The magnetic resonance imaging technique effectively detected and defined anterior visual pathway changes of radionecrosis and excluded the clinical possibility of visual loss because of tumor recurrence

  10. Molecular-beam epitaxy growth and structural characterization of semiconductor-ferromagnet heterostructures by grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Satapathy, D.K.

    2005-12-19

    The present work is devoted to the growth of the ferromagnetic metal MnAs on the semiconductor GaAs by molecular-beam epitaxy (MBE). The MnAs thin films are deposited on GaAs by molecular-beam epitaxy (MBE). Grazing incidence diffraction (GID) and reflection high-energy electron diffraction (RHEED) are used in situ to investigate the nucleation, evolution of strain, morphology and interfacial structure during the MBE growth. Four stages of the nucleation process during growth of MnAs on GaAs(001) are revealed by RHEED azimuthal scans. GID shows that further growth of MnAs films proceed via the formation of relaxed islands at a nominal thickness of 2.5 ML which increase in size and finally coalesce to form a continuous film. Early on, an ordered array of misfit dislocations forms at the interface releasing the misfit strain even before complete coalescence occurs. The fascinating complex nucleation process of MnAs on GaAs(0 0 1) contains elements of both Volmer-Weber and Stranski-Krastanov growth. A nonuniform strain amounting to 0.66%, along the [1 -1 0] direction and 0.54%, along the [1 1 0] direction is demonstrated from x-ray line profile analysis. A high correlation between the defects is found along the GaAs[1 1 0] direction. An extremely periodic array of misfit dislocations with a period of 4.95{+-}0.05 nm is formed at the interface along the [1 1 0] direction which releases the 7.5% of misfit. The inhomogeneous strain due to the periodic dislocations is confined at the interface within a layer of 1.6 nm thickness. The misfit along the [1 -1 0] direction is released by the formation of a coincidence site lattice. (orig.)

  11. Grazing incidence synchrotron X-ray diffraction and Moessbauer spectroscopy analyses of plasma nitrided ASTM F138 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Danilo Olzon Dionysio de; Ardisson, Jose Domingos, E-mail: dolzon@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silva, Edilaine Honorio [Studiecentrum voor Kernenergie (Belgium); Olzon-Dionysio, Maristela; Souza, Sylvio Dionysio de; Fabris, Jose Domingos [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil); Martinez, L.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2016-07-01

    Full text: systematic investigation of samples of plasma-nitriding austenitic stainless steels ASTM F138 and AISI 316L is reported. The surface treatment of the steels through plasma-nitriding was used to improve further the hardness, wear and corrosion resistance of these stainless steels. The resulting layered crystallographic structure actually corresponds to several phases with close cell parameters, making their identification and quantification a real experimental challenge. The ASTM F138 and AISI 316L stainless steel disks were plasma nitrided for 4 h at 400 deg C in a 80% H{sub 2} -20% N2 atmosphere at 6 torr, using plasma current frequencies between 6 and 100 kHz. Data of Moessbauer (CEMS and CXMS) and grazing incidence synchrotron X-ray diffraction (XRD-SR) were systematically collected. The nitrided layer thickness were not in general influenced by the plasma frequency, except at 12 kHz, which produced a layer thickness of approximately 8.0 mm, being in average 40% thicker than for the other samples. CXMS and CEMS Moessbauer spectra for this 12 kHz-sample show a much more pronounced magnetic resonance lines than for the other samples. The Fe{sub 4}N phase presents a single magnetic hyperfine interaction; the other two (Fe{sub 2-3}N and the expanded austenite) present both paramagnetic and magnetic components, even though their hyperfine parameters may not be safely separated. We also present the results of XRD-SR that were probed at several depths. The data from these techniques may be consistently correlated and this leads to an improved model to explain the structure of the nitrided layers. (author)

  12. Output diagnostics of the grazing incidence plane grating monochromator BUMBLE BEE (15 to 1500 eV)

    Energy Technology Data Exchange (ETDEWEB)

    Jark, W.; Kunz, C.

    1985-09-01

    The BUMBLE BEE is a bakeable uhv compatible plane grating monochromator, with a fixed exit beam, and the capability to suppress higher order radiation in a wide energy range. The instrument was built to be used in connection with a uhv reflectometer and has a differential pumping section between the optical components and the sample, allowing a pressure of 10/sup -5/ torr in the experimental chamber without influencing the uhv in the monochromator. The monochromator is not optimized for resolution. Due to its location at a beamline with a short source distance we achieve only medium resolving power in the order of E/..delta..E approx. = 200. The primary goal is the suppression of higher orders, fortunately the thus selected operating parameters for the coupled rotations of the optical components also give nearly the highest available output. The instrument is characterized in great detail. The performance of the instrument is discussed and compared with extensive theoretical calculations.

  13. Radiation effects on optical data transmission systems

    International Nuclear Information System (INIS)

    Leskovar, B.

    1989-01-01

    The state of the art of optical transmitters, low loss fiber waveguides and receivers in both steady state and pulsed radiation environments is reviewed and summarized. Emphasis is placed on the effects of irradiation on the performance of light emitting and laser diodes, optical fiber waveguides and photodiodes. The influence of radiation-induced attenuation of optical fibers due to total dose, dose rate, time after irradiation, temperature, radiation history, photobleaching, OH and impurity content, dopant type and concentration is described. The performance of candidate components of the transmission system intended for deployment in the Superconducting Super Collider Detector and primary beam tunnel nuclear environment is discussed

  14. A Test Facility For Astronomical X-Ray Optics

    DEFF Research Database (Denmark)

    Lewis, R. A.; Bordas, J.; Christensen, Finn Erland

    1989-01-01

    Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earths atmosphere. These devices require a large collection aperture and the imaging of an x-ray source which is essentially placed at infinity. The ideal testing system for these optical elements has...... to approximate that encountered under working conditions, however the testing of these optical elements is notoriously difficult with conventional x-ray generators. Synchrotron Radiation (SR) sources are sufficiently brilliant to produce a nearly perfect parallel beam over a large area whilst still retaining...... a flux considerably higher than that available from conventional x-ray generators. A facility designed for the testing of x-ray optics, particularly in connection with x-ray telescopes is described below. It is proposed that this facility will be accommodated at the Synchrotron Radiation Source...

  15. Grazing incidence x-ray diffraction analysis of zeolite NaA membranes on porous alumina tubes.

    Science.gov (United States)

    Kyotani, Tomohiro

    2006-07-01

    Zeolite NaA-type membranes hydrothermally synthesized on porous alumina tubes, for dehydration process, were characterized by grazing incidence 2 theta scan X-ray diffraction analysis (GIXRD). The fine structure of the membrane was studied fractionally for surface layer and for materials embedded in the porous alumina tube. The thickness of the surface layer on the porous alumina tube in the membranes used in this study was approximately 2-3 microm as determined from transmission electron microscopy with focused ion beam thin-layer specimen preparation technique (FIB-TEM). To discuss the effects of the membrane surface morphology on the GIXRD measurements, CaA-type membrane prepared by ion exchange from the NaA-type membrane and surface-damaged NaA-type membrane prepared by water leaching were also studied. For the original NaA-type membrane, 2 theta scan GIXRD patterns could be clearly measured at X-ray incidence angles (alpha) ranging from 0.1 to 2.0 deg in increments of 0.1 deg. The surface layers of the 2 - 3 microm on the porous alumina tube correspond to the alpha values up to ca. 0.2 deg. For the CaA-type and the surface-damaged NaA-type membranes, however, diffraction patterns from the surface layer could not be successfully detected and the others were somewhat broad. For all the three samples, diffraction intensities of both zeolite and alumina increased with depth (X-ray incidence angle, alpha) in the porous alumina tube region. The depth profile analysis of the membranes based on the GIXRD first revealed that amount of zeolite crystal embedded in the porous alumina tube is much larger than that in the surface layer. Thus, the 2 theta scan GIXRD is a useful method to study zeolite crystal growth mechanism around (both inside and outside) the porous alumina support during hydrothermal synthesis and to study water permeation behavior in the dehydration process.

  16. High-Resolution Detector for At-Wavelength Metrology of X-Ray Optics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Since the launch of the first X-ray focusing telescope in 1963, the development of grazing incidence X-ray optics has been crucial to the development of the field of...

  17. High-Resolution Detector for At-Wavelength Metrology of X-Ray Optics, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Since the launch of the first X-ray focusing telescope in 1963, the development of grazing incidence X-ray optics has been crucial to the development of the field of...

  18. Side-pumped Nd:YVO{sub 4} cw laser with grazing-incidence small angle configuration; Laser de Nd:YVO{sub 4} bombeado transversalmente em configuracao com angulo rasante interno

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Fabiola de Almeida

    2006-07-01

    Within the existing variety of laser cavity geometries and gain materials there is one combination that is particularly interesting because of its reduced complexity and high efficiency: the edge-pumped slab-laser using grazing-incidence geometry and a gain media with a very high pump absorption cross-section. In this work we studied a diode side-pumped Nd:YVO{sub 4} cw laser. We describe a single and a multiple bounce laser configurations. We demonstrate 22 W of multimode output power for 35 watts of pump power with a single pass through the gain media. A high optical-to-optical conversion efficiency of 63% and a slope efficiency of 74% with a very compact and simple Nd:YVO{sub 4} cavity that uses joint stability zones was achieved. The beam quality was M{sup 2} = 26 x 11 in the horizontal and vertical direction, respectively. With a double pass configuration we achieved 17 watts with a better beam quality of M{sup 2} = 3,4 x 3,7, in the horizontal and vertical direction, respectively. (author)

  19. Characterization of radiation within the optical region

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, H [Stuttgart Univ. (TH) (Germany, F.R.). Inst. fuer Physikalische Elektronik

    1977-04-01

    The notions which are used for the characterization of radiation within the optical region of the spectrum (quantities, units) and their temporal and geometric relations have been arranged synoptically. Quantities of the international system (SI-System) are emphasized.

  20. Radiation resistance of optical fibers, (10)

    International Nuclear Information System (INIS)

    Tsunoda, Tsunemi; Ara, Katsuyuki; Morimoto, Naoki; Sanada, Kazuo; Inada, Koichi.

    1991-01-01

    Optical fibers have many excellent characteristics such as the light weight of the material, insulation, the noninductivity of electromagnetic interference noise, the wide band of signal transmission, and small loss. Also in the field of atomic energy, the utilization of optical fibers is positively expanded, and the research on the method of application and so on has been advanced. However in optical fibers, there is the problem that color centers are formed at the relatively low level of radiation, and they are colored. Accordingly, for effectively utilizing optical fibers in radiation environment, it is indispensable to improve their radiation resistance. For the purpose of solving this problem, the authors have carried out the basic research on the effect that radiation exerts to optical fibers and the development of the optical fibers having excellent radiation resistance. For the purpose of expanding the range of application of GeO 2 -doped silica core fibers including GI type in radiation regions, the transmission characteristics of the fibers during irradiation were examined by using the Cl content as the parameter. Therefore, the results are reported. The fibers put to the test, the testing method and the results are described. (K.I.)

  1. Optical fiber-applied radiation detection system

    International Nuclear Information System (INIS)

    Nishiura, Ryuichi; Uranaka, Yasuo; Izumi, Nobuyuki

    2001-01-01

    A technique to measure radiation by using plastic scintillation fibers doped radiation fluorescent (scintillator) to plastic optical fiber for a radiation sensor, was developed. The technique contains some superiority such as high flexibility due to using fibers, relatively easy large area due to detecting portion of whole of fibers, and no electromagnetic noise effect due to optical radiation detection and signal transmission. Measurable to wide range of and continuous radiation distribution along optical fiber cable at a testing portion using scintillation fiber and flight time method, the optical fiber-applied radiation sensing system can effectively monitor space radiation dose or apparatus operation condition monitoring. And, a portable type scintillation optical fiber body surface pollution monitor can measure pollution concentration of radioactive materials attached onto body surface by arranging scintillation fiber processed to a plate with small size and flexibility around a man to be tested. Here were described on outline and fundamental properties of various application products using these plastic scintillation fiber. (G.K.)

  2. Effect of Ar9+ irradiation on Zr-1Nb-1Sn-0.1Fe alloy characterized by Grazing Incidence X-ray diffraction technique

    Science.gov (United States)

    Dutta, Argha; Das, Kalipada; Gayathri, N.; Menon, Ranjini; Nabhiraj, P. Y.; Mukherjee, Paramita

    2018-03-01

    The microstructural parameters such as domain size and microstrain have been estimated from Grazing Incidence X-ray Diffraction (GIXRD) data for Ar9+ irradiated Zr-1Nb-1Sn-0.1Fe sample as a function of dpa (dose). Detail studies using X-ray Diffraction Line Profile Analysis (XRDLPA) from GIXRD data has been carried out to characterize the microstructural parameters like domain size and microstrain. The reorientation of the grains due to effect of irradiation at high dpa (dose) has been qualitatively assessed by the texture parameter P(hkl).

  3. Inner Stucture of Thin Films of Lamellar Poly(styrene-em>b>-butadiene) Diblock Copolymers as revealed by Grazing-Incidence Small-Angle Scattering

    DEFF Research Database (Denmark)

    Busch, Peter; Posselt, Dorthe; Smilgies, Detlef-Matthias

    2007-01-01

    The lamellar orientation in supported, thin films of poly(styrene-b-butadiene) (P(S-b-B)) depends on block copolymer molar mass. We have studied films from nine block copolymer samples with molar masses between 13.9 and 183 kg/mol using grazing-incidence small-angle X-ray scattering (GISAXS) and ...... quantitatively in the framework of our recently developed distorted-wave Born approximation model (Busch, P.; et al. J. Appl. Crystallogr. 2006, 39, 433). The results cannot be explained from enthalpic considerations alone but point to the importance of entropic factors....

  4. Design of a high-efficiency grazing incidence monochromator with multilayer-coated laminar gratings for the 1-6 keV region

    International Nuclear Information System (INIS)

    Koike, Masato; Ishino, Masahiko; Sasai, Hiroyuki

    2006-01-01

    A grazing incidence objective monochromator consisting of a spherical mirror, a varied-line-spacing plane grating with multilayered coating, a movable plane multilayered mirror, and a fixed exit slit for the 1-6 keV region has been designed. The included angle at the grating was chosen to satisfy the grating equation and extended Bragg condition simultaneously. The aberration was corrected by means of a hybrid design method. A spectral resolving power of ∼600-∼6000 and a throughput of ∼2%-∼40% is expected for the monochromator when used in an undulator beamline

  5. Structure of Co-Doped Alq3 thin films investigated by grazing incidence X-ray absorption fine structure and Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Lin, Liang; Pang, Zhiyong; Fang, Shaojie; Wang, Fenggong; Song, Shumei; Huang, Yuying; Wei, Xiangjun; Yu, Haisheng; Han, Shenghao

    2011-02-10

    The structural properties of Co-doped tris(8-hydroxyquinoline)aluminum (Alq(3)) have been studied by grazing incidence X-ray absorption fine structure (GIXAFS) and Fourier transform infrared spectroscopy (FTIR). GIXAFS analysis suggests that there are multivalent Co-Alq(3) complexes and the doped Co atoms tend to locate at the attraction center with respect to N and O atoms and bond with them. The FTIR spectra indicate that the Co atoms interact with the meridional (mer) isomer of Alq(3) rather than forming inorganic compounds.

  6. Grazing incidence X-ray diffraction study of the tilted phases of Langmuir films: Determination of molecular conformations using simulated annealing

    International Nuclear Information System (INIS)

    Pignat, J.; Daillant, J.; Cantin, S.; Perrot, F.; Konovalov, O.

    2007-01-01

    We have analyzed grazing incidence X-ray diffraction (GIXD) data from condensed phases of Langmuir films of long-chain fatty acids at the air-water using a new method consisting in a careful extraction of the structure factors followed by fitting of molecular parameters using simulated annealing. We show that the information contained in GIXD spectra is enough to obtain near-atomic structural information. In particular, we directly determine the orientation of the chain backbone planes and of the carboxylic headgroups, and we evaluate chain conformation defects

  7. Grazing incidence X-ray diffraction study of the tilted phases of Langmuir films: Determination of molecular conformations using simulated annealing

    Energy Technology Data Exchange (ETDEWEB)

    Pignat, J. [LIONS/Service de Chimie Moleculaire, CEA-Saclay bat. 125, F-91191 Gif-sur-Yvette Cedex (France); LPPI, universite de Cergy-Pontoise, 5 mail Gay-Lussac Neuville/Oise, 95031 Cergy-Pontoise Cedex (France); Daillant, J. [LIONS/Service de Chimie Moleculaire, CEA-Saclay bat. 125, F-91191 Gif-sur-Yvette Cedex (France)]. E-mail: jean.daillant@cea.fr; Cantin, S. [LPPI, universite de Cergy-Pontoise, 5 mail Gay-Lussac Neuville/Oise, 95031 Cergy-Pontoise Cedex (France); Perrot, F. [LPPI, universite de Cergy-Pontoise, 5 mail Gay-Lussac Neuville/Oise, 95031 Cergy-Pontoise Cedex (France); Konovalov, O. [ESRF, 6 rue Jules Horowitz, BP220, 38043 Grenoble Cedex (France)

    2007-05-23

    We have analyzed grazing incidence X-ray diffraction (GIXD) data from condensed phases of Langmuir films of long-chain fatty acids at the air-water using a new method consisting in a careful extraction of the structure factors followed by fitting of molecular parameters using simulated annealing. We show that the information contained in GIXD spectra is enough to obtain near-atomic structural information. In particular, we directly determine the orientation of the chain backbone planes and of the carboxylic headgroups, and we evaluate chain conformation defects.

  8. Scattering of H(D) from LiF(1 0 0) under fast grazing incidence conditions: To what extent is classical dynamics a useful tool?

    Energy Technology Data Exchange (ETDEWEB)

    Muzas, A.S. [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Martín, F. [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-nanociencia), Cantoblanco, 28049 Madrid (Spain); Díaz, C., E-mail: cristina.diaz@uam.es [Departamento de Química Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2015-07-01

    Diffraction experiments of atoms and molecules under fast grazing incidence conditions have opened a new field in surface science. This experimental effort calls for complementary theoretical studies, which would allow a detailed analysis of experimental data. Here, we have analyzed the ability of classical dynamics simulations to reproduce experimental results. To perform this study, a DFT (density functional theory) based potential energy surface, describing the interaction between a H atom and a LiF(1 0 0) surface, has been computed. Diffraction probabilities have been simulated by means of a classical binning method. Our results have been found to be in qualitative good agreement with recent experimental measurements.

  9. Radiative properties of optical board embedded with optical black holes

    International Nuclear Information System (INIS)

    Qiu, J.; Liu, L.H.; Hsu, P.-F.

    2011-01-01

    Unique radiative properties, such as wavelength-selective transmission or absorption, have been intensively studied. Historically, geometries for wavelength-selective of light absorption were developed based on metallic periodical structures, which were only applied in the case of TM wave incidence due to the excitation of surface plasmons. In this paper, we develop an alternative approach to selective wavelength of light absorption (both TE and TM waves), based on an optical board periodical embedded with optical black holes. Numerical work was carried out to study such structure's radiative properties within the wavelength range of 1-100 μm. The electromagnetic wave transmission through such a structure is predicted by solving Maxwell's equations using the finite-difference time-domain (FDTD) method. Spectral absorptance varies with the period of optical black holes. When the incidence wavelength is much larger than the inner core radius, most of the light energy will be transmitted through the inner core. Otherwise, the energy will be mainly absorbed. Numerical results of the radiative properties of the optical board with different incidence wavelengths are also obtained. The effect of the oblique incidence wave is investigated. This study helps us gain a better understanding of the radiative properties of an optical board embedded with optical black holes and develop an alternative approach to selective light absorption.

  10. Radiation distribution sensor with optical fibers for high radiation fields

    International Nuclear Information System (INIS)

    Takada, Eiji; Kimura, Atsushi; Hosono, Yoneichi; Takahashi, Hiroyuki; Nakazawa, Masaharu

    1999-01-01

    Radiation distribution sensors with their feasibilities have been described in earlier works. However, due to large radiation induced transmission losses in optical fibers, especially in the visible wavelength region, it has been difficult to apply these techniques to high radiation fields. In this study, we proposed a new concept of optical fiber based radiation distribution measurements with near infrared (IR) emission. Near IR scintillators were attached to the ends of optical fibers, where the fibers were bundled and connected to an N-MOS line sensor or a cooled CCD camera. From the measurements of each area density, the radiation levels at the positions of the scintillators can be known. The linearity between the gamma dose rate at each scintillator and the registered counts has been examined. For correcting the radiation induced loss effects, we applied the Optical Time Domain Reflectometry technique to measure the loss distribution and from the results, a possibility for correction of the loss effect has been demonstrated. The applicable dose rate range was evaluated to be from 0.1 to 10 3 Gy/h. This system can be a promising tool as a flexible dose rate distribution monitor in radiation facilities like nuclear plants and accelerator facilities. (author)

  11. Effects of oxygen partial pressure and annealing temperature on the residual stress of hafnium oxide thin-films on silicon using synchrotron-based grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Debaleen [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Sinha, Anil Kumar [ISU, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Homi Bhabha National Institute, BARC, Mumbai 400 094 (India); Chakraborty, Supratic, E-mail: supratic.chakraborty@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

    2016-10-30

    Highlights: • Residual stress estimation thin hafnium oxide film with thickness of <10 nm. • A mathematical expression is proposed for stress estimation of thin-film using GIXRD. • Residual stress varies with argon content in Ar/O{sub 2} plasma and annealing temperature. • Variation of stress is explained by IL swelling and enhanced structural relaxation. - Abstract: Synchrotron radiation-based grazing incidence X-ray diffraction (GI-XRD) technique is employed here to estimate the residual stress of < 10 nm thin hafnium oxide film deposited on Si (100) substrate at different argon/oxygen ratios using reactive rf sputtering. A decrease in residual stress, tensile in nature, is observed at higher annealing temperature for the samples deposited with increasing argon ratio in the Ar/O{sub 2} plasma. The residual stress of the films deposited at higher p{sub Ar} (Ar:O{sub 2} = 4:1) is also found to be decreased with increasing annealing temperature. But the stress is more or less constant with annealing temperature for the films deposited at lower Ar/O{sub 2} (1:4) ratio. All the above phenomena can be explained on the basis of swelling of the interfacial layer and enhanced structural relaxation in the presence of excess Hf in hafnium oxide film during deposition.

  12. A compact soft x-ray (0.1–1.2 keV) calibration bench for radiometric measurements using an original versatile Rowland circle grazing incidence monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, S., E-mail: sebastien.hubert@cea.fr

    2017-05-21

    This paper describes an original Rowland circle grazing incidence spectrometer used as a monochromator for a soft x-ray Manson source in order to calibrate both the source and detectors over the 0.1–1.2 keV spectral range. The originality of the instrument lies on a patented vacuum manipulator which allows the simultaneous boarding of two detectors, one (reference) for measuring the monochromatic radiation and the second to be calibrated. In order to achieve this, the vacuum manipulator is able to interchange, in vacuum, one detector with the other in front of the exit slit of the monochromatizing stage. One purpose of this apparatus was to completely eliminate the intrinsic bremsstrahlung emission of the x-ray diode source and isolate each characteristic line for quantitative detector calibrations. Obtained spectral resolution (Δλ/λ<10{sup −2}) and spectral purity (>98%) fully meet this objective. Initially dimensioned to perform calibration of bulky x-ray cameras unfolded on the Laser MégaJoule Facility, other kinds of detector can be obviously calibrated using this instrument. A brief presentation of the first calibration of an x-ray CCD through its quantum efficiency (QE) measurement is included in this paper as example. Comparison with theoretical model for QE and previous measurements at higher energy are finally presented and discussed.

  13. Fiber optics in high dose radiation fields

    International Nuclear Information System (INIS)

    Partin, J.K.

    1985-01-01

    A review of the behavior of state-of-the-art optical fiber waveguides in high dose (greater than or equal to 10 5 rad), steady state radiation fields is presented. The influence on radiation-induced transmission loss due to experimental parameters such as dose rate, total dose, irradiation history, temperature, wavelength, and light intensity, for future work in high dose environments are given

  14. Simulation study of transverse optical klystron radiation

    International Nuclear Information System (INIS)

    Xu Hongliang; Diao Caozheng; Liu Jinying; He Duohui; Jia Qika; Wang Xiangqi

    1997-01-01

    The radiation from a transverse optical klystron (TOK) is calculated by far field approximation equation and numerical integration, in which the effects of electron-beam emittance and energy spread are considered. Accurate electron-beam profiles have been experimentally determined and modeled by the Monte Carlo method. The calculated spectra illustrate the emittance of Hefei storage ring imposes on the spontaneous radiation of TOK

  15. Ionizing radiation detector using multimode optical fibers

    International Nuclear Information System (INIS)

    Suter, J.J.; Poret, J.C.; Rosen, M.; Rifkind, J.M.

    1993-01-01

    An optical ionizing radiation detector, based on the attenuation of 850-nm light in 50/125-μm multimode fibers, is described. The detector is especially well suited for application on spacecraft because of its small design. The detection element consists of a section of coiled fibers that has been designed to strip higher-order optical modes. Cylindrical radiation shields with atomic numbers ranging from Z = 13 (aluminum too) Z = 82 (lead) were placed around the ionizing radiation detector so that the effectiveness of the detector could be measured. By exposing the shields and the detector to 1.25-MeV cobalt 60 radiation, the mass attenuation coefficients of the shields were measured. The detector is based on the phenomenon that radiation creates optical color centers in glass fibers. Electron spin resonance spectroscopy performed on the 50/125-μm fibers showed the presence of germanium oxide and phosphorus-based color centers. The intensity of these centers is directly related to the accumulated gamma radiation

  16. Bent approximations to synchrotron radiation optics

    International Nuclear Information System (INIS)

    Heald, S.

    1981-01-01

    Ideal optical elements can be approximated by bending flats or cylinders. This paper considers the applications of these approximate optics to synchrotron radiation. Analytic and raytracing studies are used to compare their optical performance with the corresponding ideal elements. It is found that for many applications the performance is adequate, with the additional advantages of lower cost and greater flexibility. Particular emphasis is placed on obtaining the practical limitations on the use of the approximate elements in typical beamline configurations. Also considered are the possibilities for approximating very long length mirrors using segmented mirrors

  17. Fiber-optic dosimeters for radiation therapy

    Science.gov (United States)

    Li, Enbang; Archer, James

    2017-10-01

    According to the figures provided by the World Health Organization, cancer is a leading cause of death worldwide, accounting for 8.8 million deaths in 2015. Radiation therapy, which uses x-rays to destroy or injure cancer cells, has become one of the most important modalities to treat the primary cancer or advanced cancer. The newly developed microbeam radiation therapy (MRT), which uses highly collimated, quasi-parallel arrays of x-ray microbeams (typically 50 μm wide and separated by 400 μm) produced by synchrotron sources, represents a new paradigm in radiotherapy and has shown great promise in pre-clinical studies on different animal models. Measurements of the absorbed dose distribution of microbeams are vitally important for clinical acceptance of MRT and for developing quality assurance systems for MRT, hence are a challenging and important task for radiation dosimetry. On the other hand, during the traditional LINAC based radiotherapy and breast cancer brachytherapy, skin dose measurements and treatment planning also require a high spatial resolution, tissue equivalent, on-line dosimeter that is both economical and highly reliable. Such a dosimeter currently does not exist and remains a challenge in the development of radiation dosimetry. High resolution, water equivalent, optical and passive x-ray dosimeters have been developed and constructed by using plastic scintillators and optical fibers. The dosimeters have peak edge-on spatial resolutions ranging from 50 to 500 microns in one dimension, with a 10 micron resolution dosimeter under development. The developed fiber-optic dosimeters have been test with both LINAC and synchrotron x-ray beams. This work demonstrates that water-equivalent and high spatial resolution radiation detection can be achieved with scintillators and optical fiber systems. Among other advantages, the developed fiber-optic probes are also passive, energy independent, and radiation hard.

  18. Optical fiber applied to radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Junior, Francisco A.B.; Costa, Antonella L.; Oliveira, Arno H. de; Vasconcelos, Danilo C., E-mail: fanbra@yahoo.com.br, E-mail: antonella@nuclear.ufmg.br, E-mail: heeren@nuclear.ufmg.br, E-mail: danilochagas@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Departamento de Engenharia Nuclear

    2015-07-01

    In the last years, the production of optical fibers cables has make possible the development of a range of spectroscopic probes for in situ analysis performing beyond nondestructive tests, environmental monitoring, security investigation, application in radiotherapy for dose monitoring, verification and validation. In this work, a system using an optical fiber cable to light signal transmission from a NaI(Tl) radiation detector is presented. The innovative device takes advantage mainly of the optical fibers small signal attenuation and immunity to electromagnetic interference to application for radiation detection systems. The main aim was to simplify the detection system making it to reach areas where the conventional device cannot access due to its lack of mobility and external dimensions. Some tests with this innovative system are presented and the results stimulate the continuity of the researches. (author)

  19. Molecular aggregation states of poly{2-(perfluorooctyl)ethyl acrylate} polymer brush thin film analyzed by grazing incidence X-ray diffraction

    International Nuclear Information System (INIS)

    Yamaguchi, H; Honda, K; Takahara, A; Kobayashi, M; Morita, M; Masunaga, H; Sasaki, S; Takata, M; Sakata, O

    2009-01-01

    Fluoropolymer brush with crystalline side chains was prepared by surface-initiated atom transfer radical polymerization of 2-(perfluorooctyl)ethyl acrylate (FA-C 8 ) from a flat silicon substrate. The crystallization and the molecular aggregation structures of polymer side chain at the outermost surface and internal region in the brush film were characterized by grazing incidence X-ray diffraction (GIXD) measurement using two different incident angles of X-ray. At the air interface of PFA-C 8 brush film, the rod-like R f group was oriented perpendicular to the surface forming a hexagonal packing structure to reduce surface energy. In contrast, the oriented R f groups parallel to the substrate coexisted at the internal region in the brush. This unique depth dependence of crystalline state of the fluoropolymer brush was observed by surface-sensitive GIXD measurement.

  20. Phase and Texture of Solution-Processed Copper Phthalocyanine Thin Films Investigated by Two-Dimensional Grazing Incidence X-Ray Diffraction

    Directory of Open Access Journals (Sweden)

    Lulu Deng

    2011-07-01

    Full Text Available The phase and texture of a newly developed solution-processed copper phthalocyanine (CuPc thin film have been investigated by two-dimensional grazing incidence X-ray diffraction. The results show that it has β phase crystalline structure, with crystallinity greater than 80%. The average size of the crystallites is found to be about 24 nm. There are two different arrangements of crystallites, with one dominating the diffraction pattern. Both of them have preferred orientation along the thin film normal. Based on the similarities to the vacuum deposited CuPc thin films, the new solution processing method is verified to offer a good alternative to vacuum process, for the fabrication of low cost small molecule based organic photovoltaics.

  1. Penetration Depth and Defect Image Contrast Formation in Grazing-Incidence X-ray Topography of 4H-SiC Wafers

    Science.gov (United States)

    Yang, Yu; Guo, Jianqiu; Goue, Ouloide Yannick; Kim, Jun Gyu; Raghothamachar, Balaji; Dudley, Michael; Chung, Gill; Sanchez, Edward; Manning, Ian

    2018-02-01

    Synchrotron x-ray topography in grazing-incidence geometry is useful for discerning defects at different depths below the crystal surface, particularly for 4H-SiC epitaxial wafers. However, the penetration depths measured from x-ray topographs are much larger than theoretical values. To interpret this discrepancy, we have simulated the topographic contrast of dislocations based on two of the most basic contrast formation mechanisms, viz. orientation and kinematical contrast. Orientation contrast considers merely displacement fields associated with dislocations, while kinematical contrast considers also diffraction volume, defined as the effective misorientation around dislocations and the rocking curve width for given diffraction vector. Ray-tracing simulation was carried out to visualize dislocation contrast for both models, taking into account photoelectric absorption of the x-ray beam inside the crystal. The results show that orientation contrast plays the key role in determining both the contrast and x-ray penetration depth for different types of dislocation.

  2. Crystalline self-assembly of organic molecules with metal ions at the air-aqueous solution interface. A grazing incidence X-ray scattering study

    DEFF Research Database (Denmark)

    Weissbuch, I.; Buller, R.; Kjær, K.

    2002-01-01

    The advent of intense X-rays from synchrotron sources made possible to probe, at the molecular level, the structural aspects of self-assemblies generated at interfaces. Here we present the two-dimensional (2-D) packing arrangements of two-, three- and multi-component organo-metallic self......-assemblies formed via interfacial reaction at the air-aqueous solution interface, as determined by grazing incidence X-ray diffraction (GIRD) and X-ray specular reflectivity techniques. GIXD yields structural information on the crystalline part of the Langmuir film, including the ions and counterions lateral order...... of metal ions bound to the polar head groups of amphipilic molecules; use of bolaamphiphiles to generate oriented thin films with metal ions arranged in periodic layers; delineation of differences in the lateral organization of metal ions at interfaces as induced by racemates and enantiomerically pure...

  3. Note: Comparison of grazing incidence small angle x-ray scattering of a titania sponge structure at the beamlines BW4 (DORIS III) and P03 (PETRA III)

    International Nuclear Information System (INIS)

    Rawolle, M.; Körstgens, V.; Ruderer, M. A.; Metwalli, E.; Guo, S.; Müller-Buschbaum, P.; Herzog, G.; Benecke, G.; Schwartzkopf, M.; Buffet, A.; Perlich, J.; Roth, S. V.

    2012-01-01

    Grazing incidence small angle x-ray scattering (GISAXS) is a powerful technique for morphology investigation of nanostructured thin films. GISAXS measurements at the newly installed P03 beamline at the storage ring PETRA III in Hamburg, Germany, are compared to the GISAXS data from the beamline BW4 at the storage ring DORIS III, which had been used extensively for GISAXS investigations in the past. As an example, a titania thin film sponge structure is investigated. Compared to BW4, at beamline P03 the resolution of larger structures is slightly improved and a higher incident flux leads to a factor of 750 in scattered intensity. Therefore, the acquisition time in GISAXS geometry is reduced significantly at beamline P03.

  4. Molecular aggregation states of poly{l_brace}2-(perfluorooctyl)ethyl acrylate{r_brace} polymer brush thin film analyzed by grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H; Honda, K; Takahara, A [Graduate School of Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395 (Japan); Kobayashi, M [Institute for Materials Chemistry and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Morita, M [Fundamental Research Department, Chemical Division, Daikin Industries, Ltd., 1-1 Nishi Hitotsuya, Settsu-shi, Osaka 566-8585 (Japan); Masunaga, H; Sasaki, S; Takata, M [Japan Synchrotron Research Institute, Mikazuki Sayo, Hyogo 671-5198 (Japan); Sakata, O, E-mail: takahara@cstf.kyushu-u.ac.j [RIKEN Harima Institute, Mikazuki Sayo, Hyogo 671-5198 (Japan)

    2009-08-01

    Fluoropolymer brush with crystalline side chains was prepared by surface-initiated atom transfer radical polymerization of 2-(perfluorooctyl)ethyl acrylate (FA-C{sub 8}) from a flat silicon substrate. The crystallization and the molecular aggregation structures of polymer side chain at the outermost surface and internal region in the brush film were characterized by grazing incidence X-ray diffraction (GIXD) measurement using two different incident angles of X-ray. At the air interface of PFA-C{sub 8} brush film, the rod-like R{sub f} group was oriented perpendicular to the surface forming a hexagonal packing structure to reduce surface energy. In contrast, the oriented R{sub f} groups parallel to the substrate coexisted at the internal region in the brush. This unique depth dependence of crystalline state of the fluoropolymer brush was observed by surface-sensitive GIXD measurement.

  5. Si Nanoribbons on Ag(110) Studied by Grazing-Incidence X-Ray Diffraction, Scanning Tunneling Microscopy, and Density-Functional Theory: Evidence of a Pentamer Chain Structure.

    Science.gov (United States)

    Prévot, Geoffroy; Hogan, Conor; Leoni, Thomas; Bernard, Romain; Moyen, Eric; Masson, Laurence

    2016-12-30

    We report a combined grazing incidence x-ray diffraction (GIXD), scanning tunneling microscopy (STM), and density-functional theory (DFT) study which clearly elucidates the atomic structure of the Si nanoribbons grown on the missing-row reconstructed Ag(110) surface. Our study allows us to discriminate between the theoretical models published in the literature, including the most stable atomic configurations and those based on a missing-row reconstructed Ag(110) surface. GIXD measurements unambiguously validate the pentamer model grown on the reconstructed surface, obtained from DFT. This pentamer atomistic model accurately matches the high-resolution STM images of the Si nanoribbons adsorbed on Ag(110). Our study closes the long-debated atomic structure of the Si nanoribbons grown on Ag(110) and definitively excludes a honeycomb structure similar to that of freestanding silicene.

  6. Discrimination and quantification of implanted solar wind in Genesis collector shards using grazing incidence synchrotron x-ray techniques: New detector initial results

    International Nuclear Information System (INIS)

    Kitts, K.; Choi, Y.; Sutton, S.R.; Ghose, S.; Burnett, D.; Eng, P.

    2008-01-01

    Accurate knowledge of the composition of the Sun provides a baseline, which allows an understanding of how the solar system has evolved over time and how solar processes and solar wind mechanics behave. Unfortunately, the errors in photospheric abundances are too large for many planetary science problems and this hampers our understanding of these different processes. Analyses of solar wind implanted in meteorites or lunar soils have provided more precise data [e.g. 1 and references therein] but the extent to which alteration processes on these bodies complicate such information is only now being determined. Therefore, in order to obtain pristine solar wind samples, NASA developed and launched the Genesis Discovery Mission. Unfortunately, the probe crash-landed shattering the 300 collector plates into 15,000+ pieces complicating the analysis and necessitating the development of new analytical techniques and equipment. Thus, shards from the Genesis collector array and their appropriate flight spares are currently being characterized via grazing-incidence synchrotron x-ray techniques at the Advanced Photon Source at Argonne National Laboratory. The goals are (1) determine solar wind fluences of the elements Ca-Ge by grazing-incidence angle-resolved x-ray fluorescence (XRF) and x-ray reflectivity, (2) improve data reduction via the development of XRF spectral deconvolution routines and develop modeling algorithms for reflectivity and fluorescence yield analysis in order to determine element specific depth profiles from which absolute concentration may be extracted and (3) designing and developing a new multi-element silicon multi-channel (SMCD) detector system. These improvements will increase our sensitivity by a factor of three or more, reduce measurement time at a given sensitivity to one-eighth and the minimum detection limit would be reduced by a factor of 3 to ∼3 x 10 8 atoms/cm 2 .

  7. Discrimination and quantification of contamination and implanted solar wind in Genesis collector shards using grazing incidence synchrotron x-ray techniques: Initial results

    International Nuclear Information System (INIS)

    Kitts, K.; Sutton, S.; Eng, P.; Ghose, S.; Burnett, D.

    2006-01-01

    Grazing incidence X-ray fluorescence is a non-destructive technique that can differentiate the embedded solar wind component from surface contamination and collector background in the Genesis shards. Initial solar Fe abundance in D30554 is 8 x 10 12 /cm 2 . Accurate knowledge of the composition of the Sun provides a baseline, which allows an understanding of how the solar system has evolved over time and how solar processes and solar wind mechanics behave. Unfortunately, the errors in photospheric abundances are too large for many planetary science problems and this hampers our understanding of these different processes. Analyses of solar wind implanted in meteorites or lunar soils have provided more precise data but alteration processes on these bodies may complicate such information. In response to this need for pristine solar wind samples, NASA developed and launched the Genesis Probe. Unfortunately, the probe smashed into the Utah desert shattering the 300 collector plates into 15,000+ pieces all of which are now coated in a both a fine terrestrial dust and Si and Ge powder from the disrupted collectors themselves. The solar wind penetration depth is 100-200 nm and the superposed contamination layers are typically 40-50 nm. Stringent cleaning regimes have the potential of removing the solar wind itself. The best solution is to have sufficient spatial resolution to separately analyze the surface contamination and penetrated solar wind. To that end, three Genesis collector array shards and their appropriate flight spares were characterized via grazing incidence x-ray fluorescence and x-ray reflectivity. The goals were (1) to evaluate the various cleaning methods used to eliminate contamination, (2) to identify the collector substrates most suited for this technique, (3) to determine whether the solar wind signature could be deconvolved from the collector background signature, and (4) to measure the relative abundances of Ca to Ge in the embedded solar wind.

  8. Therapeutic radiation apparatus having an optical pointer

    International Nuclear Information System (INIS)

    1981-01-01

    This patent specification relates to a therapeutic irradiating apparatus including a radiation source arranged to provide a beam of penetrating radiation and an optical alignment indicator comprising at least two light sources each provided with means to provide a planar divergent beam of light located so that at least two light beams intersect along a line substantially coincident with the central axis of the path of the radiation beam. The claim relates to cylindrical lenses providing the means of providing the divergent beams, and to lasers as the light sources. Claims are also made for the apparatus providing means of supporting and aligning the patient, and for disposing the light sources so that the exit point of the radiation beam is illuminated. (U.K.)

  9. Challenges and opportunities in synchrotron radiation optics

    Science.gov (United States)

    Rehn, V.

    Design necessities germaine to advances in optics for experimentation with synchrotron radiation are explored. Objectives for development include improved beam-line performance using new mirror materials or coatings, filtering and order-sorting enhancement, and lower surface scattering. A summary is presented of optical systems currently in use, together with requirements imposed by storage rings and experimental design. Advances are recommended in intensity, collimation, focus, and spectral purity of synchrotron beam lines. Any new storage ring mirror is noted to be required to dissipate several hundred watts, something which polished Cu is mentioned as being capable of handling, while standard SiO2 mirrors cannot.

  10. Radiation resistant characteristics of optical fibers

    International Nuclear Information System (INIS)

    Nakasuji, Masaaki; Tanaka, Gotaro; Watanabe, Minoru; Kyodo, Tomohisa; Mukunashi, Hiroaki

    1983-01-01

    It is required to develop the optical fibers with good radiation resistivity because the fibers cause the increase of transmission loss due to glass colouring when they are used under the presence of radiation such as γ-ray. Generally, it is known that SI (step index) fibers are more resistive to radiation than GI (graded index) fibers. However, since a wide band can not be obtained with SI fibers, the development of radiation resistive GI optical fibers is desirable. In this report, the production for trial of the GI fibers of fluorine-doped silica core, the examination of radiation effect on their optical transmission loss by exposing them to γ-ray, thermal and fast neutron beams and also of mechanical strength are described. The GI fibers of fluorine-doped silica core show better radiation resistivity than Ge-doped ones. The B- and F-doped GI fibers show small increase of loss due to γ-ray, but large increase of loss due to thermal neutron beam. This is supposed to be caused by the far greater neutron absorption cross-section of boron than that of other elements. Significant increase of loss was not recognized when 14 MeV fast neutrons (8.6 x 10 4 n/cm 2 .s) were applied by 1.8 x 10 9 n/cm 2 . It was found that ETFE-covered fiber cores generated fluorine-containing gas due to γ irradiation, and the strength was remarkably lowered, but the lowering of strength can be prevented by adding titanium-white to the covering material. (Wakatsuki, Y.)

  11. A case of presumed radiation optic neuropathy

    International Nuclear Information System (INIS)

    Atsumi, Osamu; Sakuraba, Tomoki; Kimura, Satoru; Narita, Kiyoharu; Maeda, Syuji

    1991-01-01

    A case of a 37-year-old woman with radiation optic neuropathy was reported. She had undergone subtotal removal of the right orbital tumor (adenoid cystic carcinoma) by frontal craniotomy, followed by radiation therapy (64 Gy). She had been quite well until she noticed a gradual loss of vision in her right eye 18 months later. Her visual acuity was 0.2 in the right eye and 1.5 in the left eye with right relative afferent pupillary defect and dense central scotoma. Funduscopy revealed optic disc swelling with surrounding retinal edema and small hemorrhage in the right eye. Fluorescein angiography revealed a hypoperfusion area and obstruction of the small retinal vessels in the posterior pole, but this was not large enough to explain the dense central scotoma. Although prednisolone therapy gave temporary improvement, the visual function gradually deteriorated. (author)

  12. A case of presumed radiation optic neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Atsumi, Osamu; Sakuraba, Tomoki; Kimura, Satoru; Narita, Kiyoharu; Maeda, Syuji (Hirosaki Univ., Aomori (Japan). School of Medicine)

    1991-05-01

    A case of a 37-year-old woman with radiation optic neuropathy was reported. She had undergone subtotal removal of the right orbital tumor (adenoid cystic carcinoma) by frontal craniotomy, followed by radiation therapy (64 Gy). She had been quite well until she noticed a gradual loss of vision in her right eye 18 months later. Her visual acuity was 0.2 in the right eye and 1.5 in the left eye with right relative afferent pupillary defect and dense central scotoma. Funduscopy revealed optic disc swelling with surrounding retinal edema and small hemorrhage in the right eye. Fluorescein angiography revealed a hypoperfusion area and obstruction of the small retinal vessels in the posterior pole, but this was not large enough to explain the dense central scotoma. Although prednisolone therapy gave temporary improvement, the visual function gradually deteriorated. (author).

  13. Resonant acoustic radiation force optical coherence elastography

    OpenAIRE

    Qi, Wenjuan; Li, Rui; Ma, Teng; Li, Jiawen; Kirk Shung, K.; Zhou, Qifa; Chen, Zhongping

    2013-01-01

    We report on a resonant acoustic radiation force optical coherence elastography (ARF-OCE) technique that uses mechanical resonant frequency to characterize and identify tissues of different types. The linear dependency of the resonant frequency on the square root of Young's modulus was validated on silicone phantoms. Both the frequency response spectrum and the 3D imaging results from the agar phantoms with hard inclusions confirmed the feasibility of deploying the resonant frequency as a mec...

  14. Optical Tracking Technology in Stereotactic Radiation Therapy

    International Nuclear Information System (INIS)

    Wagner, Thomas H.; Meeks, Sanford L.; Bova, Frank J.; Friedman, William A.; Willoughby, Twyla R.; Kupelian, Patrick A.; Tome, Wolfgang

    2007-01-01

    The last decade has seen the introduction of advanced technologies that have enabled much more precise application of therapeutic radiation. These relatively new technologies include multileaf collimators, 3-dimensional conformal radiotherapy planning, and intensity modulated radiotherapy in radiotherapy. Therapeutic dose distributions have become more conformal to volumes of disease, sometimes utilizing sharp dose gradients to deliver high doses to target volumes while sparing nearby radiosensitive structures. Thus, accurate patient positioning has become even more important, so that the treatment delivered to the patient matches the virtual treatment plan in the computer treatment planning system. Optical and image-guided radiation therapy systems offer the potential to improve the precision of patient treatment by providing a more robust fiducial system than is typically used in conventional radiotherapy. The ability to accurately position internal targets relative to the linac isocenter and to provide real-time patient tracking theoretically enables significant reductions in the amount of normal tissue irradiated. This report reviews the concepts, technology, and clinical applications of optical tracking systems currently in use for stereotactic radiation therapy. Applications of radiotherapy optical tracking technology to respiratory gating and the monitoring of implanted fiducial markers are also discussed

  15. Optical fibers and their applications for radiation measurements

    International Nuclear Information System (INIS)

    Kakuta, Tsunemi

    1998-01-01

    As a new method of radiation measurements, several optical methods using optical fiber sensors have been developed. One is the application of 'radio-luminescence' from the optical fiber itself such as plastic scintillating fibers. Other researches are made to develop the 'combined-sensors' by combination of optical fibers and scintillating materials. Using the time domain method of optical fiber sensors, the profile of radiation distribution along the optical fiber can be easily determined. A multi-parameter sensing system for measurement of radiation, temperature, stress, etc, are also expected using these optical fiber sensors. (author)

  16. Superhydrophobic surfaces: from fluid mechanics to optics

    NARCIS (Netherlands)

    Rathgen, H.

    2008-01-01

    In this thesis optical diraction was used to study the static and dynamic properties of microscopic liquid-gas interfaces that span between adjacent ridges of a superhydrophobic surface. An observed interference phenomenon at grazing incident angle led to the development of optical gratings with a

  17. Optical Fibers in Nuclear Reactor Radiation Environments.

    Science.gov (United States)

    Holcomb, David Eugene

    1992-01-01

    A performance evaluation of fiber optics under radiation conditions similar to those encountered in nuclear power plants is reported. The evaluation was accomplished by the creation of an analytical model for atomic scale radiation damage in silica glass and by the execution of an extensive fiber performance measurement program. The analytic model calculates displacement and electronic damage rates for silica glass subjected to a specified nuclear reactor radiation environment. It accomplishes this by first generating the primary charged particle spectrum produced in silica irradiated in a nuclear reactor. The resultant spectra are then applied to the integral equations describing radiation damage in polyatomic solids. The experimental measurements were selected to span the range of fiber types, radiation environments, temperatures, and light powers expected to be used in nuclear power plants. The basic experimental protocol was to expose the optical fibers to either a nuclear reactor or a ^{60}Co radiation environment while simultaneously monitoring fiber light transmission. Experimental temperatures were either ~23 ^circC or ~100 ^circC and light powers were either -30 dBm or -60 dBm. Measurements were made at each of the three standard communications wavelengths (850 nm, 1300 nm, and 1550 nm). Several conclusions are made based on these performance measurements. First, even near the core of a nuclear reactor the vast majority of the dose to silica glass is due to gamma rays. Even with the much lower doses (factor of roughly 40) neutrons cause much more displacement damage than gamma rays (35 times the oxygen displacement rate and 500 times the silicon displacement rate). Even with neutrons having many times the displacement rate as compared with gamma rays, little if any difference is observed in the transmission losses for gamma only as compared to mixed neutron/gamma transmission losses. Therefore, atomic displacement is not a significant damage mechanism for

  18. Combined evaluation of grazing incidence X-ray fluorescence and X-ray reflectivity data for improved profiling of ultra-shallow depth distributions

    Energy Technology Data Exchange (ETDEWEB)

    Ingerle, D., E-mail: dingerle@ati.ac.at [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria); Meirer, F. [Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht (Netherlands); Pepponi, G.; Demenev, E.; Giubertoni, D. [MiNALab, CMM-irst, Fondazione Bruno Kessler, Via Sommarive 18, I-38050 Povo (Italy); Wobrauschek, P.; Streli, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria)

    2014-09-01

    The continuous downscaling of the process size for semiconductor devices pushes the junction depths and consequentially the implantation depths to the top few nanometers of the Si substrate. This motivates the need for sensitive methods capable of analyzing dopant distribution, total dose and possible impurities. X-ray techniques utilizing the external reflection of X-rays are very surface sensitive, hence providing a non-destructive tool for process analysis and control. X-ray reflectometry (XRR) is an established technique for the characterization of single- and multi-layered thin film structures with layer thicknesses in the nanometer range. XRR spectra are acquired by varying the incident angle in the grazing incidence regime while measuring the specular reflected X-ray beam. The shape of the resulting angle-dependent curve is correlated to changes of the electron density in the sample, but does not provide direct information on the presence or distribution of chemical elements in the sample. Grazing Incidence XRF (GIXRF) measures the X-ray fluorescence induced by an X-ray beam incident under grazing angles. The resulting angle dependent intensity curves are correlated to the depth distribution and mass density of the elements in the sample. GIXRF provides information on contaminations, total implanted dose and to some extent on the depth of the dopant distribution, but is ambiguous with regard to the exact distribution function. Both techniques use similar measurement procedures and data evaluation strategies, i.e. optimization of a sample model by fitting measured and calculated angle curves. Moreover, the applied sample models can be derived from the same physical properties, like atomic scattering/form factors and elemental concentrations; a simultaneous analysis is therefore a straightforward approach. This combined analysis in turn reduces the uncertainties of the individual techniques, allowing a determination of dose and depth profile of the implanted

  19. Application of a universal optic data link for radiation measurements

    International Nuclear Information System (INIS)

    Komatsu, T.; Takada, E.

    2002-01-01

    Optic Data Link (ODL) is a device to convert electric and optic signals to each other, which is used for the field of optical communications. We examined the possibility to apply ODLs to radiation measurements. The effect of ODLs on energy and timing resolution has been investigated. From the results, fundamental applicability of ODLs to radiation measurements has been demonstrated. (author)

  20. Optical radiation emissions from compact fluorescent lamps

    International Nuclear Information System (INIS)

    Khazova, M.; O'Hagan, J.B.

    2008-01-01

    There is a drive to energy efficiency to mitigate climate change. To meet this challenge, the UK Government has proposed phasing out incandescent lamps by the end of 2011 and replacing them with energy efficient fluorescent lighting, including compact fluorescent lamps (CFLs) with integrated ballasts. This paper presents a summary of an assessment conducted by the Health Protection Agency in March 2008 to evaluate the optical radiation emissions of CFLs currently available in the UK consumer market. The study concluded that the UV emissions from a significant percentage of the tested CFLs with single envelopes may result in foreseeable overexposure of the skin when these lamps are used in desk or task lighting applications. The optical output of all tested CFLs, in addition to high-frequency modulation, had a 100-Hz envelope with modulation in excess of 15%. This degree of modulation may be linked to a number of adverse effects. (authors)

  1. Optical substrate materials for synchrotron radiation beamlines

    International Nuclear Information System (INIS)

    Howells, M.R.; Paquin, R.A.

    1997-06-01

    The authors consider the materials choices available for making optical substrates for synchrotron radiation beam lines. They find that currently the optical surfaces can only be polished to the required finish in fused silica and other glasses, silicon, CVD silicon carbide, electroless nickel and 17-4 PH stainless steel. Substrates must therefore be made of one of these materials or of a metal that can be coated with electroless nickel. In the context of material choices for mirrors they explore the issues of dimensional stability, polishing, bending, cooling, and manufacturing strategy. They conclude that metals are best from an engineering and cost standpoint while the ceramics are best from a polishing standpoint. They then give discussions of specific materials as follows: silicon carbide, silicon, electroless nickel, Glidcop trademark, aluminum, precipitation-hardening stainless steel, mild steel, invar and superinvar. Finally they summarize conclusions and propose ideas for further research

  2. Mirrors for synchrotron-radiation beamlines

    International Nuclear Information System (INIS)

    Howells, M.R.

    1993-09-01

    The authors consider the role of mirrors in synchrotron-radiation beamlines and discuss the optical considerations involved in their design. They discuss toroidal, spherical, elliptical, and paraboloidal mirrors in detail with particular attention to their aberration properties. They give a treatment of the sine condition and describe its role in correcting the coma of axisymmetric systems. They show in detail how coma is inevitable in single-reflection, grazing-incidence systems but correctable in two-reflection systems such as those of the Wolter type. In an appendix, they give the theory of point aberrations of reflectors of a general shape and discuss the question of correct naming of aberrations. In particular, a strict definition of coma is required if attempts at correction are to be based on the sine condition

  3. Simulations of the azimuthal distribution of low-energy H atoms scattered off Ag(1 1 0) at grazing incidence: DFT many-body versus model pair potentials

    CERN Document Server

    Cafarelli, P; Benazeth, C; Nieuwjaer, N; Lorente, N

    2003-01-01

    We compare the azimuthal distribution of H atoms after scattering off Ag(1 1 0) obtained by molecular dynamics with different H-Ag(1 1 0) potential energy surfaces (PES) and experimental results. We use grazing incident H atoms and low energies (up to 4 keV). Density functional theory (DFT) calculations are performed for the static case of an H atom in front of an Ag(1 1 0) surface. The surface is represented by an 8-atom slab, and the H atoms form 1x1 and 2x2 supercells. The generalized gradient approximation is used. Classical trajectories are evaluated on the obtained PES, and the azimuthal distribution of the scattered atoms is calculated. Good agreement with experiment is obtained which gives us some confidence in the correct description of the system at low energies by the static DFT calculations. These results are also compared with pair-potential calculations. The accuracy of trajectories may be important for the correct evaluation of charge transfer, energy loss and straggling during ion-surface coll...

  4. Heavy-ion induced desorption of a TiZrV coated vacuum chamber bombarded with 5 MeV/u Ar8+ beam at grazing incidence

    International Nuclear Information System (INIS)

    Hedlund, E.; Malyshev, O. B.; Westerberg, L.; Krasnov, A.; Semenov, A. S.; Leandersson, M.; Zajec, B.; Kollmus, H.; Bellachioma, M. C.; Bender, M.; Kraemer, A.; Reich-Sprenger, H.

    2009-01-01

    TiZrV nonevaporable getter (NEG) coated vacuum chambers is a new vacuum technology which is already used in many particle accelerators worldwide. This coating is also of interest for heavy-ion accelerator vacuum chambers. Heavy-ion desorption yields from an activated as well as a CO saturated NEG coated tube have been measured with 5 MeV/u Ar 8+ beam. The sticking probability of the NEG film was obtained by using the partial pressure ratios on two sides of the NEG coated tube. These ratios were compared to results of modeling of the experimental setup with test particle Monte Carlo and angular coefficient methods. The partial pressures inside the saturated NEG coated tube bombarded with heavy ions were up to 20 times larger than those inside the activated one. However, the partial pressure of methane remained the same. The value of the total desorption yield from the activated NEG coated tube is 2600 molecules/ion. The desorption yields after saturation for CH 4 , H 2 , and CO 2 were found to be very close to the yields measured after the activation, while CO increased by up to a factor of 5. The total desorption yield for the saturated tube is up to 7000 molecules/ion. The large value of the desorption yield of the activated NEG coated tube, an order of magnitude higher than the desorption yield from a stainless steel tube at normal incident angle, could be explained by the grazing incident angle

  5. Evaluation of Poisson's ratio and Young's modulus of nitride films by combining grazing incidence X-ray diffraction and laser curvature techniques

    International Nuclear Information System (INIS)

    Chen, H.-Y.; Chen, J.-H.; Lu, F.-H.

    2007-01-01

    Measurements of Poisson's ratio and the Young's modulus of thin films have been problematic. In this work, evaluation of both Poisson's ratio and Young's modulus is conducted using grazing incidence X-ray diffraction combined with measurement of the induced stress. Poisson's ratio was evaluated from analysis of the X-ray diffraction data to obtain a strain-cos 2 α.sin 2 ψ plot. Moreover, the Young's modulus of the films could be also calculated from that plot as well as from the residual stress, which could be determined by a measurement of stress induced substrate curvature. The ternary nitride TiAlN is used as a model system for the evaluation. The films, prepared by cathodic arc plasma deposition, exhibited a strong (111) preferred orientation and a composition corresponding to Ti 0.6 Al 0.4 N. The measured Poisson's ratio and the Young's modulus of the films were 0.143 ± 0.003 and 310 ± 20 GPa, respectively, which are comparable to those reported in the literature

  6. Temperature-Dependent Change of Packing Structure of Condensed-Phase in a Micro-Phase Separated Langmuir Monolayer Studied by Grazing-Incidence X-ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Iimura, Ken-ichi [Department of Applied Chemisty, Faculty of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585, Utsunomiya (Japan); Kato, Teiji [Department of Applied Chemisty, Faculty of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585, Utsunomiya (Japan); Brezesinski, Gerald [Max-Planck Instutite of Colloids and Interfaces, Research Campus Golm, D-14476 Potsdam (Germany)

    2007-10-15

    Packing structure of condensed-phase in a binary mixed Langmuir monolayer of behenic acid (C22) and perfluoro-2,5,8-trimethyl-3,6,9-trioxadodecanoic acid (PFPE) on a cadmium acetate aqueous solution was studied by grazing incidence X-ray diffraction (GIXD) as a function of the subphase temperature. The measurements were made during temperature scan at a fixed molecular area to explain the morphological change of the condensed-phase domains due to a thermal treatment reported previously. Analysis of GIXD data implies that the condensed-phase domains are composed of only the C22 molecules perpendicularly oriented and very closely packed in a centered rectangular unit cell with orthorhombic distortion at low temperatures. As the temperature increases the area occupied by molecule increases, and above 25 deg. C the lattice becomes disordered, which would allow morphological transformation of the condensed-phase domains. The process of packing structure change is almost reversible except for non-equilibrium phases observed for the monolayer spread at a low temperature, 5.5 deg. C.

  7. Packing stress reduction in polymer-lipid monolayers at the air-water interface: An X-ray grazing-incidence diffraction and reflectivity study

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, T.L.; Majewski, J.; Howes, P.B.; Kjaer, K.; Nahmen, A. von; Lee, K.Y.C.; Ocko, B.; Israelachvili, J.N.; Smith, G.S.

    1999-08-25

    Using synchrotron grazing-incidence X-ray diffraction (GIXD) and reflectivity (XR), the authors have determined the in-plane and out-of-plane structure of phospholipid monolayers at the air-water interface as a function of hydrophilic lipid headgroup size. Di-stearoyl-phosphatidyl-ethanolamine (DSPE) lipid monolayers were systematically modified by chemically grafting hydrophilic poly(ethylene glycol) (PEG) chains of MW = 90 g/mol (2 ethylene oxide, EO, units), MW = 350 g/mol (8 EO units), and MW = 750 g/mol (17 EO units) to the lipid headgroups. The monolayers were studied in the solid phase at a surface pressure of 42 mN/m. At these high lipid packing densities, the PEG chains are submerged in the water subphase. The increased packing stresses from these bulky polymer headgroups distort the unit cell and the in-plane packing modes of the monolayers, leading to large out-of-plane alterations and staggering of the lipid molecules. Surprisingly, a change in the molecular packing of the monolayer toward higher packing densities (lower area per molecule) was observed on increasing the PEG MW to 750 g/mol (17 EO units). This rearrangement of the monolayer structure may be due to a conformational change in the PEG chains.

  8. In-situ grazing incidence X-ray diffraction measurements of relaxation in Fe/MgO/Fe epitaxial magnetic tunnel junctions during annealing

    Energy Technology Data Exchange (ETDEWEB)

    Eastwood, D.S. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Ali, M.; Hickey, B.J. [Department of Physics and Astronomy, University of Leeds, Leeds LS2 1JT (United Kingdom); Tanner, B.K., E-mail: b.k.tanner@dur.ac.uk [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2013-12-15

    The relaxation of Fe/MgO/Fe tunnel junctions grown epitaxially on (001) MgO substrates has been measured by in-situ grazing incidence in-plane X-ray diffraction during the thermal annealing cycle. We find that the Fe layers are fully relaxed and that there are no irreversible changes during annealing. The MgO tunnel barrier is initially strained towards the Fe but on annealing, relaxes and expands towards the bulk MgO value. The strain dispersion is reduced in the MgO by about 40% above 480 K post-annealing. There is no significant change in the “twist” mosaic. Our results indicate that the final annealing stage of device fabrication, crucial to attainment of high TMR, induces substantial strain relaxation at the MgO barrier/lower Fe electrode interface. - Highlights: • Lattice relaxation of Fe/MgO/Fe epitaxial magnetic tunnel junctions measured. • In-plane lattice parameter of Fe equal to bulk value; totally relaxed. • MgO barrier initially strained towards the Fe but relaxes on annealing. • Reduction in strain dispersion in the MgO barrier by 40% above about 470 K. • No change in the in-plane “twist” mosaic throughout the annealing cycle.

  9. Crystal and electronic structures of pentacene thin films from grazing-incidence x-ray diffraction and first-principles calculations

    International Nuclear Information System (INIS)

    Nabok, Dmitrii; Puschnig, Peter; Ambrosch-Draxl, Claudia; Werzer, Oliver; Resel, Roland; Smilgies, Detlef-M.

    2007-01-01

    Combined experimental and theoretical investigations on thin films of pentacene are performed in order to determine the structure of the pentacene thin film phase. Grazing incidence x-ray diffraction is used for studying a pentacene thin film with a nominal thickness of 180 nm. The crystal structure is found to exhibit the lattice parameters a=0.592 nm, b=0.754 nm, c=1.563 nm, α=81.5 deg. , β=87.2 deg. , and γ=89.9 deg. . These crystallographic unit cell dimensions are used as the only input parameters for ab initio total-energy calculations within the framework of density functional theory revealing the molecular packing within the crystal structure. Moreover, we calculate the electronic band structure of the thin film phase and compare it to that of the bulk phase. We find the intermolecular bandwidths of the thin film phase to be significantly larger compared to the bulk structure, e.g., the valence bandwidth is twice as large. This remarkable effect is traced back to an enhanced intermolecular π-π overlap due to the upright standing molecules in the thin film phase

  10. Temperature-Dependent Change of Packing Structure of Condensed-Phase in a Micro-Phase Separated Langmuir Monolayer Studied by Grazing-Incidence X-ray Diffraction

    International Nuclear Information System (INIS)

    Iimura, Ken-ichi; Kato, Teiji; Brezesinski, Gerald

    2007-01-01

    Packing structure of condensed-phase in a binary mixed Langmuir monolayer of behenic acid (C22) and perfluoro-2,5,8-trimethyl-3,6,9-trioxadodecanoic acid (PFPE) on a cadmium acetate aqueous solution was studied by grazing incidence X-ray diffraction (GIXD) as a function of the subphase temperature. The measurements were made during temperature scan at a fixed molecular area to explain the morphological change of the condensed-phase domains due to a thermal treatment reported previously. Analysis of GIXD data implies that the condensed-phase domains are composed of only the C22 molecules perpendicularly oriented and very closely packed in a centered rectangular unit cell with orthorhombic distortion at low temperatures. As the temperature increases the area occupied by molecule increases, and above 25 deg. C the lattice becomes disordered, which would allow morphological transformation of the condensed-phase domains. The process of packing structure change is almost reversible except for non-equilibrium phases observed for the monolayer spread at a low temperature, 5.5 deg. C

  11. Chirality and angular momentum in optical radiation

    Science.gov (United States)

    Coles, Matt M.; Andrews, David L.

    2012-06-01

    This paper develops, in precise quantum electrodynamic terms, photonic attributes of the “optical chirality density,” one of several measures long known to be conserved quantities for a vacuum electromagnetic field. The analysis lends insights into some recent interpretations of chiroptical experiments, in which this measure, and an associated chirality flux, have been treated as representing physically distinctive “superchiral” phenomena. In the fully quantized formalism the chirality density is promoted to operator status, whose exploration with reference to an arbitrary polarization basis reveals relationships to optical angular momentum and helicity operators. Analyzing multimode beams with complex wave-front structures, notably Laguerre-Gaussian modes, affords a deeper understanding of the interplay between optical chirality and optical angular momentum. By developing theory with due cognizance of the photonic character of light, it emerges that only the spin-angular momentum of light is engaged in such observations. Furthermore, it is shown that these prominent measures of the helicity of chiral electromagnetic radiation have a common basis in differences between the populations of optical modes associated with angular momenta of opposite sign. Using a calculation of the rate of circular dichroism as an example, with coherent states to model the electromagnetic field, it is discovered that two terms contribute to the differential effect. The primary contribution relates to the difference in left- and right-handed photon populations; the only other contribution, which displays a sinusoidal distance dependence corresponding to the claim of nodal enhancements, is connected with the quantum photon number-phase uncertainty relation. From the full analysis, it appears that the term “superchiral” can be considered redundant.

  12. Remote Optical Detection of Alpha Radiation

    International Nuclear Information System (INIS)

    Sand, J.; Hannuksela, V.; Toivonen, J.; Ihantola, S.; Peraejaervi, K.; Toivonen, H.

    2010-01-01

    Alpha emitting radiation sources are typically hard to detect with conventional detectors due to the short range of alpha particles in the air. However, previous studies have shown that remote detection of alpha radiation is possible by measuring the ionization-induced fluorescence of air molecules. The alpha-induced ultraviolet (UV) light is mainly emitted by molecular nitrogen and its fluorescence properties are well known. The benefit of this method is the long range of UV photons in the air. Secondly, the detection is possible also under a strong beta and gamma radiation backgrounds as they do not cause localized molecular excitation. In this work, the optical detection was studied using two different detection schemes; spectral separation of fluorescence from the background lighting and coincidence detection of UV photons originating from a single radiative decay event. Our spectrally integrated measurements have shown that one alpha decay event yields up to 400 fluorescence photons in the air and all these UV photons are induced in a 5 ns time-window. On the other hand, the probability of a background coincidence event in 5 ns scale is very rare compared to the number of background photons. This information can be applied in fluorescence coincidence filtering to discriminate the alpha radiation initiated fluorescence signal from much more intense background lighting. A device called HAUVA (Handheld Alpha UV Application) was built during this work for demonstration purposes. HAUVA utilizes spectral filtering and it is designed to detect alpha emitters from a distance of about 40 cm. Using specially selected room lighting, the device is able to separate 1 kBq alpha emitter from the background lighting with 1 second integration time. (author)

  13. Radiation distribution sensing with normal optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Kawarabayashi, Jun; Mizuno, Ryoji; Naka, Ryotaro; Uritani, Akira; Watanabe, Ken-ichi; Iguchi, Tetsuo [Nagoya Univ., Dept. of Nuclear Engineering, Nagoya, Aichi (Japan); Tsujimura, Norio [Japan Nuclear Cycle Development Inst., Tokai Works, Tokai, Ibaraki (Japan)

    2002-12-01

    The purpose of this study is to develop a radiation distribution monitor using a normal plastic optical fiber. The monitor has a long operating length (10m-100m) and can obtain continuous radiation distributions. A principle of the position sensing is based on a time-of-flight technique. The characteristics of this monitor to beta particles, gamma rays and fast neutrons were obtained. The spatial resolutions for beta particles ({sup 90}Sr{sup -90}Y), gamma rays ({sup 137}Cs) and D-T neutrons were 30 cm, 37 cm and 13 cm, respectively. The detection efficiencies for the beta rays, the gamma rays and D-T neutrons were 0.11%, 1.6x10{sup -5}% and 5.4x10{sup -4}%, respectively. The effective attenuation length of the detection efficiency was 18m. New principle of the position sensing based on spectroscopic analysis was also proposed. A preliminary test showed that the spectrum observed at the end of the fiber depended on the position of the irradiated point. This fact shows that the radiation distributions were calculated from the spectrum by mathematical deconvolution technique. (author)

  14. Radiation distribution sensing with normal optical fiber

    International Nuclear Information System (INIS)

    Kawarabayashi, Jun; Mizuno, Ryoji; Naka, Ryotaro; Uritani, Akira; Watanabe, Ken-ichi; Iguchi, Tetsuo; Tsujimura, Norio

    2002-01-01

    The purpose of this study is to develop a radiation distribution monitor using a normal plastic optical fiber. The monitor has a long operating length (10m-100m) and can obtain continuous radiation distributions. A principle of the position sensing is based on a time-of-flight technique. The characteristics of this monitor to beta particles, gamma rays and fast neutrons were obtained. The spatial resolutions for beta particles ( 90 Sr -90 Y), gamma rays ( 137 Cs) and D-T neutrons were 30 cm, 37 cm and 13 cm, respectively. The detection efficiencies for the beta rays, the gamma rays and D-T neutrons were 0.11%, 1.6x10 -5 % and 5.4x10 -4 %, respectively. The effective attenuation length of the detection efficiency was 18m. New principle of the position sensing based on spectroscopic analysis was also proposed. A preliminary test showed that the spectrum observed at the end of the fiber depended on the position of the irradiated point. This fact shows that the radiation distributions were calculated from the spectrum by mathematical deconvolution technique. (author)

  15. X-ray optics for axion helioscopes

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Pivovaroff, Michael J.; Christensen, Finn Erland

    2013-01-01

    A method of optimizing grazing incidence x-ray coatings in ground based axion helioscopes is presented. Software has been been developed to find the optimum coating when taking both axion spectrum and Micromegas detector quantum efficiency into account. A comparison of the relative effective area...... of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only....

  16. Optical radiation, with particular reference to lasers

    International Nuclear Information System (INIS)

    Goldman, L.; Michaelson, S.M.; Rockwell, R.J.; Sliney, D.H.; Tengroth, B.M.; Wolbarsht, M.L.

    1989-01-01

    Laser emissions cover wavelengths from 10 nm to 1 mm and are used in a wide variety of applications. The interactions between biological tissues and laser radiation depend on irradiance and radiant exposure, exposure duration and wavelength. Because of the relatively superficial absorption, the major biological effects are on the skin and the eye. The health hazards to the skin are both acute (thermal burns, sunburn, photosensitized reactions) and chronic (accelerated aging and photocarcinogenesis). The main health hazards to the eye are photokeratitis, corneal burns, photochemical and thermal cataract, ocular inflammation, and photo-chemical, thermal and thermo-acoustic retinal injury and optical breakdown within the eye. Secondary haemorrhage in the vitreous humour with complete loss of vision could be produced by severe damage to the retina. 59 refs, 6 figs, 8 tabs

  17. Study of interface correlation in W/C multilayer structure by specular and non-specular grazing incidence X-ray reflectivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, A., E-mail: arupb@barc.gov.in; Bhattacharyya, D.; Sahoo, N. K. [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Maidul Haque, S.; Tripathi, S.; De, Rajnarayan [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, VIZAG Centre, Visakhapatnam 530012 (India); Rai, S. [Indus Synchrotron Utilization Division, Raja Raman Centre for Advanced Technology, Indore 452013 (India)

    2015-10-28

    W/C/W tri-layer thin film samples have been deposited on c-Si substrates in a home-built Ion Beam Sputtering system at 1.5 × 10{sup −3} Torr Ar working pressure and 10 mA grid current. The tri-layer samples have been deposited at different Ar{sup +} ion energies between 0.6 and 1.2 keV for W layer deposition and the samples have been characterized by specular and non-specular grazing incidence X-ray reflectivity (GIXR) measurements. By analyzing the GIXR spectra, various interface parameters have been obtained for both W-on-C and C-on-W interfaces and optimum Ar{sup +} ion energy for obtaining interfaces with low imperfections has been found. Subsequently, multilayer W/C samples with 5-layer, 7-layer, 9-layer, and 13-layer have been deposited at this optimum Ar{sup +} ion energy. By fitting the specular and diffused GIXR data of the multilayer samples with the parameters of each interface as fitting variables, different interface parameters, viz., interface width, in-plane correlation length, interface roughness, and interface diffusion have been estimated for each interface and their variation across the depth of the multilayers have been obtained. The information would be useful in realizing W/C multilayers for soft X-ray mirror application in the <100 Å wavelength regime. The applicability of the “restart of the growth at the interface” model in the case of these ion beam sputter deposited W/C multilayers has also been investigated in the course of this study.

  18. Relationship between electrical properties and crystallization of indium oxide thin films using ex-situ grazing-incidence wide-angle x-ray scattering

    Science.gov (United States)

    González, G. B.; Okasinski, J. S.; Buchholz, D. B.; Boesso, J.; Almer, J. D.; Zeng, L.; Bedzyk, M. J.; Chang, R. P. H.

    2017-05-01

    Grazing-incidence, wide-angle x-ray scattering measurements were conducted on indium oxide thin films grown on silica substrates via pulsed laser deposition. Growth temperatures (TG) in this study ranged from -50 °C to 600 °C, in order to investigate the thermal effects on the film structure and its spatial homogeneity, as well as their relationship to electrical properties. Films grown below room temperature were amorphous, while films prepared at TG = 25 °C and above crystallized in the cubic bixbyite structure, and their crystalline fraction increased with deposition temperature. The electrical conductivity (σ) and electrical mobility (μ) were strongly enhanced at low deposition temperatures. For TG = 25 °C and 50 °C, a strong ⟨100⟩ preferred orientation (texture) occurred, but it decreased as the deposition temperature, and consequential crystallinity, increased. Higher variations in texture coefficients and in lattice parameters were measured at the film surface compared to the interior of the film, indicating strong microstructural gradients. At low crystallinity, the in-plane lattice spacing expanded, while the out-of-plane spacing contracted, and those values merged at TG = 400 °C, where high μ was measured. This directional difference in lattice spacing, or deviatoric strain, was linear as a function of both deposition temperature and the degree of crystallinity. The crystalline sample with TG = 100 °C had the lowest mobility, as well as film diffraction peaks which split into doublets. The deviatoric strains from these doublet peaks differ by a factor of four, supporting the presence of both a microstructure and strain gradient in this film. More isotropic films exhibit larger μ values, indicating that the microstructure directly correlates with electrical properties. These results provide valuable insights that can help to improve the desirable properties of indium oxide, as well as other transparent conducting oxides.

  19. Optical camera system for radiation field

    International Nuclear Information System (INIS)

    Maki, Koichi; Senoo, Makoto; Takahashi, Fuminobu; Shibata, Keiichiro; Honda, Takuro.

    1995-01-01

    An infrared-ray camera comprises a transmitting filter used exclusively for infrared-rays at a specific wavelength, such as far infrared-rays and a lens used exclusively for infrared rays. An infrared ray emitter-incorporated photoelectric image converter comprising an infrared ray emitting device, a focusing lens and a semiconductor image pick-up plate is disposed at a place of low gamma-ray dose rate. Infrared rays emitted from an objective member are passed through the lens system of the camera, and real images are formed by way of the filter. They are transferred by image fibers, introduced to the photoelectric image converter and focused on the image pick-up plate by the image-forming lens. Further, they are converted into electric signals and introduced to a display and monitored. With such a constitution, an optical material used exclusively for infrared rays, for example, ZnSe can be used for the lens system and the optical transmission system. Accordingly, it can be used in a radiation field of high gamma ray dose rate around the periphery of the reactor container. (I.N.)

  20. Radiation distribution sensing with normal optical fiber

    CERN Document Server

    Kawarabayashi, J; Naka, R; Uritani, A; Watanabe, K I; Iguchi, T; Tsujimura, N

    2002-01-01

    The purpose of this study is to develop a radiation distribution monitor using a normal plastic optical fiber. The monitor has a long operating length (10m-100m) and can obtain continuous radiation distributions. A principle of the position sensing is based on a time-of-flight technique. The characteristics of this monitor to beta particles, gamma rays and fast neutrons were obtained. The spatial resolutions for beta particles ( sup 9 sup 0 Sr sup - sup 9 sup 0 Y), gamma rays ( sup 1 sup 3 sup 7 Cs) and D-T neutrons were 30 cm, 37 cm and 13 cm, respectively. The detection efficiencies for the beta rays, the gamma rays and D-T neutrons were 0.11%, 1.6x10 sup - sup 5 % and 5.4x10 sup - sup 4 %, respectively. The effective attenuation length of the detection efficiency was 18m. New principle of the position sensing based on spectroscopic analysis was also proposed. A preliminary test showed that the spectrum observed at the end of the fiber depended on the position of the irradiated point. This fact shows that t...

  1. Mechanical reliability assessment of optical fibres in Radiation environments

    International Nuclear Information System (INIS)

    Van Uffelen, M.

    2006-01-01

    After more than two decades of intensive research and even some pioneering applications in space, optical fibres are now finding their way in various radiation environments, including both fission and future fusion nuclear-power plants, and high-energy physics experiments. For example, next to distributed monitoring applications of large nuclear infrastructures, fibre-optics can also be used for data communications during maintenance operations in the reactor vessel of the future ITER (International Thermonuclear Experimental Reactor), or for plasma diagnostics applications during operation of the reactor. These maintenance and diagnostics tasks require the optical fibres to withstand extremely high doses of radiation, up to MGy dose levels and temperatures above 150 degrees Celsius. The reliability assessment of fibre-optic systems for their qualification in nuclear environments often requires to meet stringent radiation tolerance levels. The majority of (usually accelerated) radiation assessments have so far focused on optical properties, such as wavelength-dependent radiation induced attenuation and radio-luminescence. The relation of these radiation effects with the fabrication methods and other environmental parameters has been the subject of years of research. Only a few results are available on the long-term evolution of mechanical properties of irradiated optical fibres. As a first step towards understanding the long-term reliability of fibre-optic composite cables in hostile radiation environments, we therefore performed dynamic fatigue tests with different commercial-grade optical fibres, both multi-mode and single-mode types

  2. Radiation optic neuropathy after external beam radiation therapy for acromegaly: report of two cases

    International Nuclear Information System (INIS)

    Bergh, Alfons C.M. van den; Hoving, Marjanke A.; Links, Thera P.; Dullaart, Robin P.F.; Ranchor, Adelita V.; Weeme, Cees A. ter; Canrinus, Alof A.; Szabo, Ben G.; Pott, Jan-Willem R.

    2003-01-01

    For diagnosing radiation optic neuropathy (RON) ophthalmological and imaging data were evaluated from 63 acromegalic patients, irradiated between 1967 and 1998. Two patients developed RON: one patient in one optic nerve 10 years and another patient in both optic nerves 5 months after radiation therapy. RON is a rare complication after external beam radiation therapy for acromegaly, which can occur after a considerable latency period

  3. Optical Imaging of Ionizing Radiation from Clinical Sources.

    Science.gov (United States)

    Shaffer, Travis M; Drain, Charles Michael; Grimm, Jan

    2016-11-01

    Nuclear medicine uses ionizing radiation for both in vivo diagnosis and therapy. Ionizing radiation comes from a variety of sources, including x-rays, beam therapy, brachytherapy, and various injected radionuclides. Although PET and SPECT remain clinical mainstays, optical readouts of ionizing radiation offer numerous benefits and complement these standard techniques. Furthermore, for ionizing radiation sources that cannot be imaged using these standard techniques, optical imaging offers a unique imaging alternative. This article reviews optical imaging of both radionuclide- and beam-based ionizing radiation from high-energy photons and charged particles through mechanisms including radioluminescence, Cerenkov luminescence, and scintillation. Therapeutically, these visible photons have been combined with photodynamic therapeutic agents preclinically for increasing therapeutic response at depths difficult to reach with external light sources. Last, new microscopy methods that allow single-cell optical imaging of radionuclides are reviewed. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  4. Future metrology needs for FEL reflective optics

    International Nuclear Information System (INIS)

    Assoufid, L.

    2000-01-01

    An International Workshop on Metrology for X-ray and Neutron Optics has been held March 16-17, 2000, at the Advanced Photon Source, Argonne National Laboratory, near Chicago, Illinois (USA). The workshop gathered engineers and scientists from both the U.S. and around the world to evaluate metrology instrumentation and methods used to characterize surface figure and finish for long grazing incidence optics used in beamlines at synchrotrons radiation sources. This two-day workshop was motivated by the rapid evolution in the performance of x-ray and neutron sources along with requirements in optics figure and finish. More specifically, the performance of future light sources, such as free-electron laser (FEL)-based x-ray sources, is being pushed to new limits in term of both brilliance and coherence. As a consequence, tolerances on surface figure and finish of the next generation of optics are expected to become tighter. The timing of the workshop provided an excellent opportunity to study the problem, evaluate the state of the art in metrology instrumentation, and stimulate innovation on future metrology instruments and techniques to be used to characterize these optics. This paper focuses on FEL optics and metrology needs. (A more comprehensive summary of the workshop can be found elsewhere.) The performance and limitations of current metrology instrumentation will be discussed and recommendations from the workshop on future metrology development to meet the FEL challenges will be detailed

  5. Future metrology needs for FEL reflective optics.

    Energy Technology Data Exchange (ETDEWEB)

    Assoufid, L.

    2000-09-21

    An International Workshop on Metrology for X-ray and Neutron Optics has been held March 16-17, 2000, at the Advanced Photon Source, Argonne National Laboratory, near Chicago, Illinois (USA). The workshop gathered engineers and scientists from both the U.S. and around the world to evaluate metrology instrumentation and methods used to characterize surface figure and finish for long grazing incidence optics used in beamlines at synchrotrons radiation sources. This two-day workshop was motivated by the rapid evolution in the performance of x-ray and neutron sources along with requirements in optics figure and finish. More specifically, the performance of future light sources, such as free-electron laser (FEL)-based x-ray sources, is being pushed to new limits in term of both brilliance and coherence. As a consequence, tolerances on surface figure and finish of the next generation of optics are expected to become tighter. The timing of the workshop provided an excellent opportunity to study the problem, evaluate the state of the art in metrology instrumentation, and stimulate innovation on future metrology instruments and techniques to be used to characterize these optics. This paper focuses on FEL optics and metrology needs. (A more comprehensive summary of the workshop can be found elsewhere.) The performance and limitations of current metrology instrumentation will be discussed and recommendations from the workshop on future metrology development to meet the FEL challenges will be detailed.

  6. Four cases of radiation retinopathy and optic neuropathy

    International Nuclear Information System (INIS)

    Konari, Kenji; Suzuki, Jun-ichi; Nakagawa, Takashi

    1996-01-01

    We observed retinopathy and optic neuropathy in 4 patients after radiation for malignancies in the paranasal sinus or the brain. The dosis ranged from 56 Gy for 14 days to 64 Gy for 32 days. The interval between the termination of radiation and onset of fundus lesions ranged from 1 to 36 months, average 16.6 months. The retinopathy appeared as retinal hemorrhage, soft exudates and vitreous hemorrhage. Neovascular glaucoma developed in one eye. The optic neuropathy appeared as pallor of optic disc, disc edema or optic papillitis. Histological studies of one eye with retinopathy showed thickening of retinal capillary walls and rubeosis iridis with angle closure. (author)

  7. Four cases of radiation retinopathy and optic neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Konari, Kenji; Suzuki, Jun-ichi; Nakagawa, Takashi [Sapporo Medical Coll. (Japan)

    1996-03-01

    We observed retinopathy and optic neuropathy in 4 patients after radiation for malignancies in the paranasal sinus or the brain. The dosis ranged from 56 Gy for 14 days to 64 Gy for 32 days. The interval between the termination of radiation and onset of fundus lesions ranged from 1 to 36 months, average 16.6 months. The retinopathy appeared as retinal hemorrhage, soft exudates and vitreous hemorrhage. Neovascular glaucoma developed in one eye. The optic neuropathy appeared as pallor of optic disc, disc edema or optic papillitis. Histological studies of one eye with retinopathy showed thickening of retinal capillary walls and rubeosis iridis with angle closure. (author).

  8. Program description of FIBRAM (Fiber Optic Radiation Attenuation Model): a radiation attenuation model for optical fibers

    International Nuclear Information System (INIS)

    Ingram, W.J.

    1987-06-01

    The report describes a fiber-optics system model and its computer implementation. This implementation can calculate the bit error ratio (BER) versus time for optical fibers that have been exposed to gamma radiation. The program is designed so that the user may arbitrarily change any or all of the system input variables and produce separate outputs. The primary output of the program is a table of the BER as a function of time. This table may be stored on magnetic media and later incorporated into computer graphic programs. The program was written in FORTRAN 77 for the IBM PC/AT/XT computers. Flow charts and program listings are included in the report

  9. Optical fibers and their applications for radiation measurements

    International Nuclear Information System (INIS)

    Kakuta, Tsunemi

    1998-01-01

    When optical fibers are used in a strong radiation field, it is necessary to increase the radiation-resistant capacity. Aiming at the improvement of such property, the characteristics of recent optical fibers made from quartz-glass were reviewed and the newly developed techniques for radiation measurement using those fibers were summarized in this report. Since optical fibers became able to use in the levels near the core conditions, their applications have started in various fields of technologies related to radiation. By combining the optical fibers and a small sensor, it became possible to act as 'Key Component' for measuring wide range radioactivity from a trace activity to a strong radiation field in the reactor core. Presently, the fibers are utilized for investigation of the optical mechanisms related in radiation, evaluation of their validities so on. Further, the optical fibers are expected to utilize in a multi-parametric measuring system which allows to concomitantly determine the radiation, temperature, pressure, flow amount etc. as an incore monitor. (M.N.)

  10. Optical fibers and their applications for radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kakuta, Tsunemi [Japan Atomic Energy Research Inst., Tokyo (Japan)

    1998-07-01

    When optical fibers are used in a strong radiation field, it is necessary to increase the radiation-resistant capacity. Aiming at the improvement of such property, the characteristics of recent optical fibers made from quartz-glass were reviewed and the newly developed techniques for radiation measurement using those fibers were summarized in this report. Since optical fibers became able to use in the levels near the core conditions, their applications have started in various fields of technologies related to radiation. By combining the optical fibers and a small sensor, it became possible to act as `Key Component` for measuring wide range radioactivity from a trace activity to a strong radiation field in the reactor core. Presently, the fibers are utilized for investigation of the optical mechanisms related in radiation, evaluation of their validities so on. Further, the optical fibers are expected to utilize in a multi-parametric measuring system which allows to concomitantly determine the radiation, temperature, pressure, flow amount etc. as an incore monitor. (M.N.)

  11. Serial Diffusion Tensor Imaging of the Optic Radiations after Acute Optic Neuritis

    Directory of Open Access Journals (Sweden)

    Scott C. Kolbe

    2016-01-01

    Full Text Available Previous studies have reported diffusion tensor imaging (DTI changes within the optic radiations of patients after optic neuritis (ON. We aimed to study optic radiation DTI changes over 12 months following acute ON and to study correlations between DTI parameters and damage to the optic nerve and primary visual cortex (V1. We measured DTI parameters [fractional anisotropy (FA, axial diffusivity (AD, radial diffusivity (RD, and mean diffusivity (MD] from the optic radiations of 38 acute ON patients at presentation and 6 and 12 months after acute ON. In addition, we measured retinal nerve fibre layer thickness, visual evoked potential amplitude, optic radiation lesion load, and V1 thickness. At baseline, FA was reduced and RD and MD were increased compared to control. Over 12 months, FA reduced in patients at an average rate of −2.6% per annum (control = −0.51%; p=0.006. Change in FA, RD, and MD correlated with V1 thinning over 12 months (FA: R=0.450, p=0.006; RD: R=-0.428, p=0.009; MD: R=-0.365, p=0.029. In patients with no optic radiation lesions, AD significantly correlated with RNFL thinning at 12 months (R=0.489, p=0.039. In conclusion, DTI can detect optic radiation changes over 12 months following acute ON that correlate with optic nerve and V1 damage.

  12. Review of high bandwidth fiber optics radiation sensors

    International Nuclear Information System (INIS)

    Lyons, P.B.

    1985-01-01

    This paper summarizes the use of fiber optics or guided optical systems for radiation sensors. It is limited a passive systems wherein electrical is not required at the sensor location. However, electrically powered light sources, receivers and/or recorders may still be required for detection and data storage in sensor system operation. This paper emphasizes sensor technologies that permit high bandwidth measurements of transient radiation levels, and will also discuss several low bandwidth applications. 60 refs

  13. Effect of gamma radiation on optical and electrical properties of ...

    Indian Academy of Sciences (India)

    Wintec

    Tellurium dioxide; thin films; optical bandgap; gamma radiation dose; dosimeter. 1. Introduction. It is now ... material to ionizing radiations (such as X-rays, gamma rays, beta ..... Mag. 19 19. Mott N F and Davis E 1979 Electronic process in non-.

  14. Normal and grazing incidence pulsed laser deposition of nanostructured MoSx hydrogen evolution catalysts from a MoS2 target

    Science.gov (United States)

    Fominski, V. Yu.; Romanov, R. I.; Fominski, D. V.; Dzhumaev, P. S.; Troyan, I. A.

    2018-06-01

    Pulsed laser ablation of a MoS2 target causes enhanced splashing of the material. So, for MoSx films obtained by pulsed laser deposition (PLD) in the conventional normal incidence (NI) configuration, their typical morphology is characterized by an underlying granular structure with an overlayer of widely dispersed spherical Mo and MoSx particles possessing micro-, sub-micro- and nanometer sizes. We investigated the possibility of using high surface roughness, which occurs due to particle deposition, as a support with a large exposed surface area for thin MoSx catalytic layers for the hydrogen evolution reaction (HER). For comparison, the HER performance of MoSx layers formed by grazing incidence (GI) PLD was studied. During GI-PLD, a substrate was placed along the direction of laser plume transport and few large particles loaded the substrate. The local structure and composition of thin MoSx layers formed by the deposition of the vapor component of the laser plume were varied by changing the pressure of the buffer gas (argon, Ar). In the case of NI-PLD, an increase in Ar pressure caused the formation of quasi-amorphous MoSx (x ≥ 2) films that possessed highly active catalytic sites on the edges of the layered MoS2 nanophase. At the same time, a decrease in the deposition rate of the MoSx film appeared due to the scattering of the vapor flux by Ar molecules during flux transport from the target to the substrate. This effect prevented uniform deposition of the MoSx catalytic film on the surface of most particles, whose deposition rate was independent of Ar pressure. The scattered vapor flux containing Mo and S atoms was a dominant source for MoSx film growth during GI-PLD. The thickness and composition distribution of the MoSx film on the substrate depended on both the pressure of the buffer gas and the distance from the target. For 1.0-2.5 cm from the target, the deposition rate was quite sufficient to form S-enriched quasi-amorphous MoSx (2.5 < x < 6) catalytic

  15. Optical fibres in the radiation environment of CERN

    Science.gov (United States)

    Guillermain, E.

    2017-11-01

    CERN, the European Organization for Nuclear Research (in Geneva, Switzerland), is home to a complex scientific instrument: the 27-kilometre Large Hadron Collider (LHC) collides beams of high-energy particles at close to the speed of light. Optical fibres are widely used at CERN, both in surface areas (e.g. for inter-building IT networks) and in the accelerator complex underground (e.g. for cryogenics, vacuum, safety systems). Optical fibres in the accelerator are exposed to mixed radiation fields (mainly composed of protons, pions, neutrons and other hadrons, gamma rays and electrons), with dose rates depending on the particular installation zone, and with radiation levels often significantly higher than those encountered in space. In the LHC and its injector chain radiation levels range from relatively low annual doses of a few Gy up to hundreds of kGy. Optical fibres suffer from Radiation Induced Attenuation (RIA, expressed in dB per unit length) that affect light transmission and which depends on the irradiation conditions (e.g. dose rate, total dose, temperature). In the CERN accelerator complex, the failure of an optical link can affect the proper functionality of control or monitoring systems and induce the interruption of the accelerator operation. The qualification of optical fibres for installation in critical radiation areas is therefore crucial. Thus, all optical fibre types installed in radiation areas at CERN are subject to laboratory irradiation tests, in order to evaluate their RIA at different total dose and dose rates. This allows the selection of the appropriate optical fibre type (conventional or radiation resistant) compliant with the requirements of each installation. Irradiation tests are performed in collaboration with Fraunhofer INT (irradiation facilities and expert team in Euskirchen, Germany). Conventional off-the-shelf optical fibres can be installed for optical links exposed to low radiation levels (i.e. annual dose typically below few

  16. Glaucoma severity affects diffusion tensor imaging (DTI) parameters of the optic nerve and optic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sidek, S. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Medical Imaging Unit, Faculty of Medicine, Universiti Teknologi MARA, Selangor (Malaysia); Ramli, N. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Rahmat, K., E-mail: katt_xr2000@yahoo.com [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Ramli, N.M.; Abdulrahman, F. [Department of Ophthalmology, Faculty of Medicine, University Malaya, Kuala Lumpur (Malaysia); Tan, L.K. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia)

    2014-08-15

    Objectives: To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness. Methods: 3-Tesla DTI was performed on 90 subjects (30 normal, 30 mild glaucoma and 30 severe glaucoma subjects) and the FA and MD of the optic nerve and optic radiation were measured. The categorisation into mild and severe glaucoma was done using the Hodapp–Parrish–Anderson (HPA) classification. RNFL thickness was also assessed on all subjects using OCT. Receiver operating characteristic (ROC) analysis and Spearman's correlation coefficient was carried out. Results: FA and MD values in the optic nerve and optic radiation decreased and increased respectively as the disease progressed. FA at the optic nerve had the highest sensitivity (87%) and specificity (80%). FA values displayed the strongest correlation with RNFL thickness in the optic nerve (r = 0.684, p ≤ 0.001) while MD at the optic radiation showed the weakest correlation with RNFL thickness (r = −0.360, p ≤ 0.001). Conclusions: The high sensitivity and specificity of DTI-derived FA values in the optic nerve and the strong correlation between DTI-FA and RNFL thickness suggest that these parameters could serve as indicators of disease severity.

  17. Glaucoma severity affects diffusion tensor imaging (DTI) parameters of the optic nerve and optic radiation

    International Nuclear Information System (INIS)

    Sidek, S.; Ramli, N.; Rahmat, K.; Ramli, N.M.; Abdulrahman, F.; Tan, L.K.

    2014-01-01

    Objectives: To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness. Methods: 3-Tesla DTI was performed on 90 subjects (30 normal, 30 mild glaucoma and 30 severe glaucoma subjects) and the FA and MD of the optic nerve and optic radiation were measured. The categorisation into mild and severe glaucoma was done using the Hodapp–Parrish–Anderson (HPA) classification. RNFL thickness was also assessed on all subjects using OCT. Receiver operating characteristic (ROC) analysis and Spearman's correlation coefficient was carried out. Results: FA and MD values in the optic nerve and optic radiation decreased and increased respectively as the disease progressed. FA at the optic nerve had the highest sensitivity (87%) and specificity (80%). FA values displayed the strongest correlation with RNFL thickness in the optic nerve (r = 0.684, p ≤ 0.001) while MD at the optic radiation showed the weakest correlation with RNFL thickness (r = −0.360, p ≤ 0.001). Conclusions: The high sensitivity and specificity of DTI-derived FA values in the optic nerve and the strong correlation between DTI-FA and RNFL thickness suggest that these parameters could serve as indicators of disease severity

  18. Spectral and kinetic analysis of radiation induced optical attenuation in silica: towards intrinsic fibre optic dosimetry?

    International Nuclear Information System (INIS)

    Borgermans, P.

    2002-01-01

    The document is an abstract of a PhD thesis. The PhD work concerns the detailed investigation of the behaviour of optical fibres in radiation fields such as is the case for various nuclear and space application,s. The core of the work concerns the spectral and kinetic analysis of the radiation induced optical attenuation. Models describing underlying physical phenomena, both for the spectral and the time dimensions, have been developed. The potential of silica optical fibre waveguides for intrinsic dosimetry has been assessed by employing specific properties of radiation induced defects in the silica waveguide material

  19. Measurement of radiation damage on an optical reflector

    International Nuclear Information System (INIS)

    Peng, K.C.; Sahu, S.K.; Huang, H.C.; Ueno, K.; Chang, Y.H.; Wang, C.H.; Hou, W.S.

    1997-01-01

    We measured the radiation damage on an optical white fluorocarbon reflector called Goretex, which is to be used for aerogel threshold counters and crystal calorimeters of the BELLE detector of the KEK B-factory. Reflectance of the Goretex surface was monitored to see any effect of the radiation damage. Maximum equivalent dose was 8.6 Mrad. No radiation damage is observed within measurement errors. (orig.)

  20. Integration of optical fibers in radiative environments: Advantages and limitations

    International Nuclear Information System (INIS)

    Girard, S.; Ouerdane, Y.; Boukenter, A.; Marcandella, C.; Bisutti, J.; Baggio, J.; Meunier, J. P.

    2011-01-01

    We review the advantages and limitations for the integration of optical fibers in radiative environments. Optical fibers present numerous advantages for applications in harsh environments such as their electromagnetic immunity. This explains the increasing interest of the radiation effects community to evaluate their vulnerability for future facilities. However, it is also well-known that optical fibers suffer from a degradation of their macroscopic properties under irradiation. We illustrate the major mechanisms and parameters that govern the degradation mechanism, mainly the radiation-induced attenuation phenomena. We focus on the fiber transient radiation responses when exposed to the pulsed and mixed environment associated with the Megajoule class lasers devoted to the fusion by inertial confinement study. (authors)

  1. Diffusion tensor imaging of occult injury of optic radiation following optic neuritis in multiple sclerosis.

    Science.gov (United States)

    Chen, Jiafeng; Zhu, Lijun; Li, He; Lu, Ziwen; Chen, Xin; Fang, Shaokuan

    2016-10-01

    Multiple sclerosis (MS) is easily detected by routine magnetic resonance imaging (MRI). However, it is not possible to detect early or occult lesions in MS by routine MRI, and this may explain the inconsistency between the severity of the lesions found by MRI and the degree of clinical disability of patients with MS. The present study included 10 patients with relapsing-remitting MS and 10 healthy volunteers. Each patient underwent routine 3.0 T MRI, diffusion tensor imaging (DTI), and diffusion tensor tractography (DTT). Optic nerve and optic radiation were analyzed by DTI and DTT. The fractional anisotropy (FA), mean diffusivity (MD), λ // , and λ ┴ values were measured. In the 10 patients with MS, 7 optic nerves were affected, and 13 optic nerves were not affected. Cranial MRI showed that optic nerve thickening and hyperintensity occurred in 2 patients with MS. In the directionally encoded color maps, a hypointensive green signal in the optic nerve was observed in 3 patients with MS. The FA values were significantly lower and the MD, λ // , and λ ┴ values were significantly higher in the affected and unaffected optic nerves and optic radiations in patients with MS in comparison with controls (P0.05). Diffusion tensor imaging is sensitive in the detection of occult injury of the optic nerve and optic radiation following optic neuritis. Diffusion tensor imaging may be a useful tool for the early diagnosis, treatment and management of MS.

  2. Surface morphology and in-plane-epitaxy of SmBa2Cu3O7-δ films on SrTiO3 (001) substrates studied by STM and grazing incidence x-ray diffraction

    DEFF Research Database (Denmark)

    Jiang, Q.D.; Smilgies, D.M.; Feidenhans'l, R.

    1996-01-01

    The surface morphology and in-plane epitaxy of thin films of SmBa(2)Cu3O(7-delta) (Sm-BCO) grown on SrTiO3 (001) substrates with various thicknesses have been investigated by scanning tunneling microscopy (STM) and grazing incidence x-ray diffraction (GIXRD). As revealed by GIXRD, SmBCO films as ...... films above h(c2), introduction of screw dislocations leads to spiral growth.......The surface morphology and in-plane epitaxy of thin films of SmBa(2)Cu3O(7-delta) (Sm-BCO) grown on SrTiO3 (001) substrates with various thicknesses have been investigated by scanning tunneling microscopy (STM) and grazing incidence x-ray diffraction (GIXRD). As revealed by GIXRD, SmBCO films...... substrate. Three different types of surface morphology were observed by STM with increasing film thickness h: a) 2D growth for hh(c2). With GIXRD, a density modulation is observed in the films with a thickness below h(c2). For thicker...

  3. Strain, size and composition of InAs quantum sticks, embedded in InP, determined via X-ray anomalous diffraction and diffraction anomalous fine structure in grazing incidence

    International Nuclear Information System (INIS)

    Letoublon, A.; Favre-Nicolin, V.; Renevier, H.; Proietti, M.G.; Monat, C.; Gendry, M.; Marty, O.; Priester, C.

    2005-01-01

    We report on the study of strain, size and composition of small-size encapsulated semiconductor nanostructures. We show that the partial structure factor of As atoms in InAs stick-like nanostructures (quantum sticks), embedded in InP, can be directly extracted from grazing incidence anomalous X-ray diffraction maps at the As K-edge. We have recovered the average height and strain of the islands and determined their composition. The average height of the quantum sticks (QSs), as deduced from the width of the structure factor profile is 2.54 nm. The InAs out of plane deformation, relative to InP, is equal to 6.1%. Fixed-Q anomalous diffraction spectra, measured at the As K-edge, in grazing incidence provide clear evidence of pure InAs QSs. This is confirmed by the analysis of the diffraction anomalous fine structure (DAFS) that also gives a direct way to recover the strain accomodation inside the quantum sticks. Finite difference method calculations reproduce well the diffraction data. Chemical mixing at interfaces is at most 1 ML. This paper shows that ultimate application of anomalous diffraction and DAFS together with reciprocal space maps is a powerful method to sudy the structural properties of nanostructures

  4. A zone plate soft x-ray microscope using monochromatized undulator radiation at the beamline NE1B of the TRISTAN Accumulation Ring

    International Nuclear Information System (INIS)

    Wang, J.; Kagoshima, Y.; Miyahara, T.; Ando, M.; Aoki, S.; Anderson, E.; Attwood, D.; Kern, D.

    1995-01-01

    A soft x-ray microscope has been developed at the beamline NE1B of the 6.5-GeV TRISTAN Accumulation Ring (AR). It makes use of undulator radiation as its source and a zone plate with the outermost zone width of 50 nm as its imaging element. It has two main features. First, the undulator radiation is monochromatized by a grazing incidence grating monochromator to match to the monochromaticity requirement of the zone plate. Second, a visible light prefocus unit consisting of two objectives has been designed and installed in the x-ray microscope. The x-ray optical system of the microscope can be adjusted easily, quickly, and precisely by using this unit. The microscope can resolve 55-nm lines and spaces in a zone plate test pattern

  5. Optical systems for synchrotron radiation. Lecture 1. Introductory topics. Revision

    International Nuclear Information System (INIS)

    Howells, M.R.

    1986-02-01

    Various fundamental topics are considered which underlie the design and use of optical systems for synchrotron radiation. The point of view of linear system theory is chosen which acts as a unifying concept throughout the series. In this context the important optical quantities usually appear as either impulse response functions (Green's functions) or frequency transfer functions (Fourier Transforms of the Green's functions). Topics include the damped harmonic oscillator, free-space optical field propagation, optical properties of materials, dispersion, and the Kramers-Kronig relations

  6. Hard X-ray Optics Technology Development for Astronomy at the Marshall Space Flight Center

    Science.gov (United States)

    Gubarev, Mikhail; Ramsey, Brian; Kilaru, Kiranmayee

    2009-01-01

    Grazing-incidence telescopes based on Wolter 1 geometry have delivered impressive advances in astrophysics at soft-x-ray wavelengths, while the hard xray region remains relatively unexplored at fine angular resolution and high sensitivities. The ability to perform ground-breaking science in the hard-x-ray energy range had been the motivation for technology developments aimed at fabricating low-cost, light-weight, high-quality x-ray mirrors. Grazing-incidence x-ray optics for high-energy astrophysical applications is being developed at MSFC using the electroform-nickel replication process.

  7. Optical fiber composition and radiation hardness

    International Nuclear Information System (INIS)

    Wall, J.A.; Loretz, T.J.

    1982-01-01

    Germanium phosphosilicate and germanium borosilicate fibers doped with cerium were fabricated and tested for their responses to steady-state Co-60 radiation at -55 C, +20 C and +125 C. A fiber with germanium, boron and phosphorous in the silicate core and doped with antimony in the core and clad was similarly tested. All of the fibers showed significant improvements in radiation hardness at 20 C compared to undoped fibers of the same base composition. At -55 C, however, all except the cerium doped germanium phosphosilicate were very radiation sensitive and also showed increases in the rate of induced loss at +125 C. The cerium doped germanium phosphosilicate fiber showed virtually no change in radiation sensitivity at the temperature extremes and could prove useful in applications requiring relatively short lengths of fiber

  8. Radiation-induced optic neuropathy: A magnetic resonance imaging study

    International Nuclear Information System (INIS)

    Guy, J.; Mancuso, A.; Beck, R.; Moster, M.L.; Sedwick, L.A.; Quisling, R.G.; Rhoton, A.L. Jr.; Protzko, E.E.; Schiffman, J.

    1991-01-01

    Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain

  9. Radiation damage in commercial optical fibers

    International Nuclear Information System (INIS)

    Bertolotti, M.; Franceschini, F.A.; Serra, A.

    1978-01-01

    Experimental results obtained by exposure of commercial optical fibers to 60 Co γ-ray irradiation, are reported. The possibility of utilizing these fibers as far as a total dose of 6000 rad in the light spectrum is shown. It is also shown that it is possible to obtain total recovery of irradiated fibers by annealing at 500 0 C. (author)

  10. Convenient models of the atmosphere: optics and solar radiation

    Science.gov (United States)

    Alexander, Ginsburg; Victor, Frolkis; Irina, Melnikova; Sergey, Novikov; Dmitriy, Samulenkov; Maxim, Sapunov

    2017-11-01

    Simple optical models of clear and cloudy atmosphere are proposed. Four versions of atmospheric aerosols content are considered: a complete lack of aerosols in the atmosphere, low background concentration (500 cm-3), high concentrations (2000 cm-3) and very high content of particles (5000 cm-3). In a cloud scenario, the model of external mixture is assumed. The values of optical thickness and single scattering albedo for 13 wavelengths are calculated in the short wavelength range of 0.28-0.90 µm, with regard to the molecular absorption bands, that is simulated with triangle function. A comparison of the proposed optical parameters with results of various measurements and retrieval (lidar measurement, sampling, processing radiation measurements) is presented. For a cloudy atmosphere models of single-layer and two-layer atmosphere are proposed. It is found that cloud optical parameters with assuming the "external mixture" agrees with retrieved values from airborne observations. The results of calculating hemispherical fluxes of the reflected and transmitted solar radiation and the radiative divergence are obtained with the Delta-Eddington approach. The calculation is done for surface albedo values of 0, 0.5, 0.9 and for spectral values of the sandy surface. Four values of solar zenith angle: 0°, 30°, 40° and 60° are taken. The obtained values are compared with data of radiative airborne observations. Estimating the local instantaneous radiative forcing of atmospheric aerosols and clouds for considered models is presented together with the heating rate.

  11. Heavy irradiation effects in radiation-resistant optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Shikama, Tatsuo [Tohoku Univ., Oarai, Ibaraki (Japan). Oarai Branch, Inst. for Materials Research

    1998-07-01

    Development of a system for optical measurements in a nuclear reactor has been progressing to investigate dynamic changes in a material caused by heavy irradiation. In such system, transfer of optical signals to out-pile measuring systems is being attempted by the use of optical fibers. In this report, the characteristics of optical fibers in the heavy irradiation field were summarized. It has been known that amorphous silica might produce radiolysis and structural defects by the exposure to ionizing radiation. The effects of heavy irradiation on molten silica were extremely complicated. A large intensity of visible light absorption occurred from an early time during start-up of the reactor. The absorption range was limited below 700 nm for the radiation associating fast neutron and the absorption was mostly attributed to non-bridging oxygen hole center. The depletion of optical transferring capacity under the radiation might be related to the internal stress. Therefore, it seems desirable to use optical fibers in the conditions without leading too much stress. (M.N.)

  12. Radiation hardness of new Kuraray double cladded optical fibers

    International Nuclear Information System (INIS)

    Bedeschi, F.; Menzione, A.; Budagov, Yu.; Chirikov-Zorin, I.; Solov'ev, A.; Turchanovich, L.; Vasil'chenko, V.

    1996-01-01

    The radiation hardness of the new plastic scintillating and clear fibers irradiated by 137 Cs γ-flux and by pulsed reactor fast neutrons were investigated. All the studied fibers were of S-type (with S=70) and had a double cladding. Optical fibers degradation study after irradiation shows that the level of radiation hardness lower that what is expected from results of previous studies. 9 refs., 6 figs

  13. Radiation Effects on Ytterbium-doped Optical Fibers

    Science.gov (United States)

    2014-06-02

    conducted on Er- doped fiber amplifiers (Lezius, et al., 2012; Ahrens, et al., 1999; Ahrens, Jaques , LuValle, DiGiovanni, & Windeler, 2001; Ott, 2004...Ahrens, R. G., Abate, J. A., Jaques , J. J., Presby, H. M., Fields, A. B., DiGiovanni, D. J., LuValle, M. J. (1999). Radiation reliability of rare... Jaques , J. J., LuValle, M. J., DiGiovanni, D. J., & Windeler, R. S. (2001). Radiation effects on optical fibers and amplifiers. Testing, Reliability

  14. Effects of angular misalignment on optical klystron undulator radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, G., E-mail: gmishra_dauniv@yahoo.co.in; Prakash, Bramh; Gehlot, Mona

    2015-11-21

    In this paper ,we analyze the important effects of optical klystron undulator radiation with an angular offset of the relativistic electron beam in the second undulator section. An anlytical expression for the undulator radiation is obtained through a transparent and simple procedure.It is shown that the effects of the angular offset is more severe for longer undulator lengths and with higher dispersive field strengths.Both these effects are less pronounced for undulators with large K values.

  15. Basic study on radiation distribution sensing with normal optical fiber

    International Nuclear Information System (INIS)

    Naka, R.; Kawarabayashi, J.; Uritani, A.; Iguchi, T.; Kaneko, J.; Takeuchi, H.; Kakuta, T.

    2000-01-01

    Recently, some methods of radiation distribution sensing with optical fibers have been proposed. These methods employ scintillating fibers or scintillators with wavelength-shifting fibers. The positions of radiation interactions are detected by applying a time-of-flight (TOF) technique to the scintillation photon propagation. In the former method, the attenuation length for the scintillation photons in the scintillating fiber is relatively short, so that the operating length of the sensor is limited to several meters. In the latter method, a radiation distribution cannot continuously be obtained but discretely. To improve these shortcomings, a normal optical fiber made of polymethyl methacrylate (PMMA) is used in this study. Although the scintillation efficiency of PMMA is very low, several photons are emitted through interaction with a radiation. The fiber is transparent for the emitted photons to have a relatively long operating length. A radiation distribution can continuously be obtained. This paper describes a principle of the position sensing method based on the time of flight technique and preliminary results obtained for 90 Sr- 90 Y beta rays, 137 Cs gamma rays, and 14 MeV neutrons. The spatial resolutions for the above three kinds of radiations are 0.30 m, 0.37 m, 0.13 m, and the detection efficiencies are 1.1 x 10 -3 , 1.6 x 10 -7 , 5.4 x 10 -6 , respectively, with 10 m operation length. The results of a spectroscopic study on the optical property of the fiber are also described. (author)

  16. Study of optical radiation from SiO2 during reactor irradiation

    International Nuclear Information System (INIS)

    Shikama, Tatsuo; Narui, Minoru; Kakuta, Tsunemi; Kayano, Hideo; Sagawa, Tsutomu; Sanada, Kazuo

    1994-01-01

    Optical radiations were observed from optical fibers under irradiation in a fission reactor, JMTR. A major part of the observed optical radiations is thought to be composed of broad optical radiation in the whole wavelength range studied in the present experiment. This broad optical radiation will be generated by the process of so-called Cherenkov radiation. Also, a sharp optical radiation peak was found at 1270 nm on a F-doped fiber. This peak is thought to relate with doped fluorine ions and ionizing gamma-ray irradiation. ((orig.))

  17. Radiation-hard/high-speed parallel optical links

    Energy Technology Data Exchange (ETDEWEB)

    Gan, K.K., E-mail: gan@mps.ohio-state.edu [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Buchholz, P.; Heidbrink, S. [Fachbereich Physik, Universität Siegen, Siegen (Germany); Kagan, H.P.; Kass, R.D.; Moore, J.; Smith, D.S. [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Vogt, M.; Ziolkowski, M. [Fachbereich Physik, Universität Siegen, Siegen (Germany)

    2016-09-21

    We have designed and fabricated a compact parallel optical engine for transmitting data at 5 Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) array in an optical package. The ASIC is designed using only core transistors in a 65 nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modulation currents of the individual channels in the VCSEL array. The performance of the optical engine up at 5 Gb/s is satisfactory.

  18. Optical systems for synchrotron radiation. Lecture 2. Mirror systems

    International Nuclear Information System (INIS)

    Howells, M.R.

    1986-02-01

    The process of reflection of VUV and x-radiation is summarized. The functions of mirrors in synchrotron beamlines are described, which include deflection, filtration, power absorption, formation of a real image, focusing, and collimation. Fabrication of optical surfaces for synchrotron radiation beamlines are described, and include polishing of a near spherical surface as well as bending a cylindrical surface to toroidal shape. The imperfections present in mirrors, aberrations and surface figure inaccuracy, are discussed. Calculation of the thermal load of a mirror in a synchrotron radiation beam and the cooling of the mirror are covered briefly. 50 refs., 7 figs

  19. Survey Talk--New Laser and Optical Radiation Diagnostics

    International Nuclear Information System (INIS)

    Leemans, W.P.

    1998-01-01

    New techniques am reported for electron beam monitoring, that rely either on the analysis of the properties of wiggler radiation (from static magnetic fields as well as from laser ''undulators'', also referred to as Thomson scattering) or on the non-linear mixing of laser radiation with electron beam radiation. The different techniques reviewed are capable of providing information on femtosecond time scales and micron or even sub-micron spatial scales. The laser undulator is also proposed as a useful tool for non- destructive measurement of high power electron beams. An example is given of measuring electron beam energy and energy spread through spectral filtering of spontaneous wiggler radiation [1]. A novel technique based on fluctuational characteristics of radiation is described, for single shot, nondestructive measurement of the electron beam bunch length [2,3]. Thomson scattering based beam monitoring techniques are discussed which, through analysis of the radiated beam properties, allow non-destructive detailed measurement of transverse and longitudinal distributions of relativistic electron beams [4]. Two new techniques are discussed which rely on non-linear optical mixing of laser radiation with electron bunch emission: differential optical gating (DOG) [5] and electron bunch length measurement in a storage ring based on sum-frequency generation [6

  20. Fiber-optic multipoint radiation sensing system using waveguide scintillators

    International Nuclear Information System (INIS)

    Maekawa, Tatsuyuki; Yoda, Masaki; Tanaka, Koutarou; Masumaru, Tarou; Morimoto, Souichirou.

    1996-01-01

    Novel fiber-optic radiation sensors and a multipoint measurement method that takes advantage of them have been developed. The new sensor design, which we call a 'waveguide scintillator', consists of a scintillating material and a wavelength-shifting fiber (WLSF). The WLSF is embedded in the scintillating material, and each end is connected to a transparent optical fiber. These waveguide scintillators can be connected in series along an optical fiber loop to form a radiation monitoring system, and each end of the fiber loop is terminated with a photodetector. This new radiation monitoring arrangement dispenses with the need for electronic apparatus at each measuring point and consequently improves resistance to noise. Furthermore, it offers the advantages of multipoint monitoring - meaning that radiation intensity can be measured at multiple sensors - using only two photodetectors. We have examined the light output characteristics and time resolution of a prototype arrangement of these new waveguide scintillators, thus confirming the feasibility of multipoint measurements using a system of multiple waveguide scintillators connected in series in an optical fiber loop. (author)

  1. Atomic, molecular, and optical physics electromagnetic radiation

    CERN Document Server

    Dunning, F B; Lucatorto, Thomas

    1997-01-01

    Combined with Volumes 29A and 29B, this volume is a comprehensive treatment of the key experimental methods of atomic, molecular, and optical physics, as well as an excellent experimental handbook for the field. Thewide availability of tunable lasers in the past several years has revolutionized the field and lead to the introduction of many new experimental methods that are covered in these volumes. Traditional methods are also included to ensure that the volumes will be a complete reference source for the field.

  2. Electron cascades in sensors for optical detection of ionizing radiation

    International Nuclear Information System (INIS)

    London, Richard A.; Lowry, Mark E.; Vernon, Stephen P.; Stewart, Richard E.

    2013-01-01

    A new class of high-speed detectors, called RadOptic detectors, measures ionizing radiation incident on a transparent semiconductor by sensing changes in the refractive index with an optical probe beam. We describe the role of radiation-initiated electron cascades in setting the sensitivity and the spatial and temporal resolution of RadOptic detectors. We model electron cascades with both analytical and Monte Carlo computational methods. We find that the timescale for the development of an electron cascade is less than of order 100 fs and is not expected to affect the time response of a detector. The characteristic size of the electron cloud is typically less than 2 μm, enabling high spatial resolution in imaging systems. The electron-hole pair density created by single x-rays is much smaller than the saturation density and, therefore, single events should not saturate the detector

  3. Development and characterization of coatings on Silicon Pore Optics substrates for the ATHENA mission

    DEFF Research Database (Denmark)

    Ferreira, Desiree Della Monica; Jakobsen, Anders Clemen; Christensen, Finn Erland

    2012-01-01

    roughness in the coatings. Both processes show promising results. Measurements of the coatings were carried out at the 8 keV X-ray facility at DTU Space and with synchrotron radiation in the laboratory of PTB at BESSY II to determine re ectivity at the grazing incidence angles and energies of ATHENA...

  4. Report on the Radiation Effects Testing of the Infrared and Optical Transition Radiation Camera Systems

    Energy Technology Data Exchange (ETDEWEB)

    Holloway, Michael Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-20

    Presented in this report are the results tests performed at Argonne National Lab in collaboration with Los Alamos National Lab to assess the reliability of the critical 99Mo production facility beam monitoring diagnostics. The main components of the beam monitoring systems are two cameras that will be exposed to radiation during accelerator operation. The purpose of this test is to assess the reliability of the cameras and related optical components when exposed to operational radiation levels. Both X-ray and neutron radiation could potentially damage camera electronics as well as the optical components such as lenses and windows. This report covers results of the testing of component reliability when exposed to X-ray radiation. With the information from this study we provide recommendations for implementing protective measures for the camera systems in order to minimize the occurrence of radiation-induced failure within a ten month production run cycle.

  5. Optical emission behavior and radiation resistance of epoxy resins

    International Nuclear Information System (INIS)

    Kawanishi, Shunichi; Udagawa, Akira; Hagiwara, Miyuki

    1987-11-01

    To make clear a mechanism of radiation resistance of epoxy resin systems, a role of energy trapping site induced in bisphenol A type epoxy resins cured with 4 kinds of aromatic amines (Φ N ) was studied in comparison with the case of aliphatic amine curing system through a measurement of optical emission. In the system of the epoxy resin cured with DETA, the optical emission from an excited state of bisphenol A unit of epoxy resin and a charge transfer complex was observed. On the other hand, the optical emission from Φ N was observed in the aromatic amine curing system. Their excitation spectrum consists of peaks of absorption spectrum of BA and those of Φ N , showing that the excited state of Φ N is formed through the excitation of both BA and Φ N . Therefore, the excited energy of BA transfers to the excited state of Φ N . Emission intensity of Φ N band was 20 ∼ 100 times as large as that of BA. These results indicate that the radiation energy is effectively released as an optical emission from excited state of Φ N in the epoxy resin when cured with aromatic amine. It can be concluded from the above results that aromatic amine hardeners contribute to enhancement of the radiation resistance of epoxy resin by acting as an energy transfer agent. (author)

  6. Radiation resistance characteristics of optical communication system for single mode

    International Nuclear Information System (INIS)

    Ohe, Masamoto; Chigusa, Yoshiki; Kyodo, Tomohisa; Tanaka, Gohtaro; Watanabe, Hajime; Okamoto, Shin-ichi; Yamamoto, Takao.

    1988-01-01

    Optical communication has been utilized also for nuclear power stations and fuel reporocessing plants. As the sufficient safety countermeasures are required there, the amount of information becomes enormous, therefore, optical communication, by which the required space is expected to be reduced, becomes more important. Also in the application to submarine cables, attention must be paid to the radiation resistance as there are the effects of potassium contained in large amount in seawater and uranium deposits in sea bottom. Therefore, the reliability of the components of optical communication systems against radiation becomes a problem. In this study, single mode optical fibers and transmission and receipt modules were selected, and high dose rate irradiation supposing the case of using in a cell and low dose rate, long time irradiation supposing the case of submarine cables were carried out to evaluate the radiation resistance characteristics. The fibers tested were SiO 2 core/F-SiO 2 clad type and GeO 2 -SiO 2 core/SiO 2 clad type. The characteristics of increasing loss in irradiation and restoration after irradiation of the former type were superior to those of the latter type. The output of a receipt module was normal during irradiation, and the output power of a transmission module decreases, but other problems did not arise. (K.I.)

  7. The cloud radiation impact from optics simulation and airborne observation

    Science.gov (United States)

    Melnikova, Irina; Kuznetsov, Anatoly; Gatebe, Charles

    2017-02-01

    The analytical approach of inverse asymptotic formulas of the radiative transfer theory is used for solving inverse problems of cloud optics. The method has advantages because it does not impose strict constraints, but it is tied to the desired solution. Observations are accomplished in extended stratus cloudiness, above a homogeneous ocean surface. Data from NASA`s Cloud Absorption Radiometer (CAR) during two airborne experiments (SAFARI-2000 and ARCTAS-2008) were analyzed. The analytical method of inverse asymptotic formulas was used to retrieve cloud optical parameters (optical thickness, single scattering albedo and asymmetry parameter of the phase function) and ground albedo in all 8 spectral channels independently. The method is free from a priori restrictions and there is no links to parameters, and it has been applied to data set of different origin and geometry of observations. Results obtained from different airborne, satellite and ground radiative experiments appeared consistence and showed common features of values of cloud parameters and its spectral dependence (Vasiluev, Melnikova, 2004; Gatebe et al., 2014). Optical parameters, retrieved here, are used for calculation of radiative divergence, reflected and transmitted irradiance and heating rates in cloudy atmosphere, that agree with previous observational data.

  8. Radiation-induced attenuation in integrated optical materials

    International Nuclear Information System (INIS)

    Evans, B.D.

    1989-01-01

    This paper reports that three materials commonly employed in opto-electronic integrated circuits evaluated for radiation-induced optical attenuation in the range 300 nm to 3000 nm. These include optically clear epoxy and crystalline lithium niobate after Co-60 exposure and crystalline tellurium dioxide after mixed gamma/fast-neutron exposure. In all these materials, however, induced loss was restricted to shorter wavelengths; attenuation induced at the telecommunications windows near 850, 1300 and 1550 nm was <0.1 dB/cm

  9. Radiation resistance of electro-optic polymer-based modulators

    International Nuclear Information System (INIS)

    Taylor, Edward W.; Nichter, James E.; Nash, Fazio D.; Haas, Franz; Szep, Attila A.; Michalak, Richard J.; Flusche, Brian M.; Cook, Paul R.; McEwen, Tom A.; McKeon, Brian F.; Payson, Paul M.; Brost, George A.; Pirich, Andrew R.; Castaneda, Carlos; Tsap, Boris; Fetterman, Harold R.

    2005-01-01

    Mach-Zehnder interferometric electro-optic polymer modulators composed of highly nonlinear phenyltetraene bridge-type chromophores within an amorphous polycarbonate host matrix were investigated for their resistance to gamma rays and 25.6 MeV protons. No device failures were observed and the majority of irradiated modulators exhibited decreases in half-wave voltage and optical insertion losses compared to nonirradiated control samples undergoing aging processes. Irradiated device responses were attributed to scission, cross-linking, and free volume processes. The data suggests that strongly poled devices are less likely to de-pole under the influence of ionizing radiation

  10. Fiber optic components compatibility with the PWR containment radiation field

    International Nuclear Information System (INIS)

    Breuze, G.; Serre, J.

    1990-01-01

    Present and future applications of fiber optics transmission in the nuclear industrial field are emphasized. Nuclear acceptance criteria for relevant electronic equipments in terms of radiation dose rate, integrated dose and required reliability are given. Ambient conditions of PWR containment are especially considered in the present paper. Experimental results of optical fibers and end-components exposed to 60 Co gamma rays are successively shown. Main radiation response characteristics up to 10 4 Gy (with dose rates of about 100 Gy.h -1 ) of both multimodal fiber families (step index and gradient index fibers) are compared. Predominant features of pure silica core fibers are: * an efficient photobleaching with near IR light from LED and LD commonly used in transmission data links, * a radiation hardening reducing induced losses down to 10 dB.km -1 in fine fibers up to date with latest developments. Dose rate effect on induced losses is also outlined for these fibers. Optoelectronic fiber-end components radiation response is good only for special LED (AsGa) and PD (Si). Radiation behavior of complex pigtailed LDM (laser diode + photodiode + Peltier element + thermistor) is not fully acceptable and technological improvements were made. Preliminary results are given. Two applications of fiber links transmitting data in a PWR containment and a hot cell are described. Hardening levels obtained and means required are given

  11. Modeling silica aerogel optical performance by determining its radiative properties

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2016-02-01

    Full Text Available Silica aerogel has been known as a promising candidate for high performance transparent insulation material (TIM. Optical transparency is a crucial metric for silica aerogels in many solar related applications. Both scattering and absorption can reduce the amount of light transmitted through an aerogel slab. Due to multiple scattering, the transmittance deviates from the Beer-Lambert law (exponential attenuation. To better understand its optical performance, we decoupled and quantified the extinction contributions of absorption and scattering separately by identifying two sets of radiative properties. The radiative properties are deduced from the measured total transmittance and reflectance spectra (from 250 nm to 2500 nm of synthesized aerogel samples by solving the inverse problem of the 1-D Radiative Transfer Equation (RTE. The obtained radiative properties are found to be independent of the sample geometry and can be considered intrinsic material properties, which originate from the aerogel’s microstructure. This finding allows for these properties to be directly compared between different samples. We also demonstrate that by using the obtained radiative properties, we can model the photon transport in aerogels of arbitrary shapes, where an analytical solution is difficult to obtain.

  12. Modeling silica aerogel optical performance by determining its radiative properties

    Science.gov (United States)

    Zhao, Lin; Yang, Sungwoo; Bhatia, Bikram; Strobach, Elise; Wang, Evelyn N.

    2016-02-01

    Silica aerogel has been known as a promising candidate for high performance transparent insulation material (TIM). Optical transparency is a crucial metric for silica aerogels in many solar related applications. Both scattering and absorption can reduce the amount of light transmitted through an aerogel slab. Due to multiple scattering, the transmittance deviates from the Beer-Lambert law (exponential attenuation). To better understand its optical performance, we decoupled and quantified the extinction contributions of absorption and scattering separately by identifying two sets of radiative properties. The radiative properties are deduced from the measured total transmittance and reflectance spectra (from 250 nm to 2500 nm) of synthesized aerogel samples by solving the inverse problem of the 1-D Radiative Transfer Equation (RTE). The obtained radiative properties are found to be independent of the sample geometry and can be considered intrinsic material properties, which originate from the aerogel's microstructure. This finding allows for these properties to be directly compared between different samples. We also demonstrate that by using the obtained radiative properties, we can model the photon transport in aerogels of arbitrary shapes, where an analytical solution is difficult to obtain.

  13. Phase control effects in optical diffraction radiation from a slit

    International Nuclear Information System (INIS)

    Castellano, M.; Chiadroni, E.; Cianchi, A.

    2010-01-01

    Optical Diffraction Radiation (ODR) from a slit is becoming a real promising instrument for measuring the transverse beam size, or even the emittance of the very high brightness linacs driving SASE FELs or the future ILC which require non-intercepting diagnostic devices. But to correctly explain experimental data it is necessary to further develop the theory of this radiation emission. In this paper we discuss in particular the effects of a non-perfect coplanarity of the two halves of a slit, that introduces a phase difference in the field produced by the two half-planes. Such non-coplanarity can result from mechanical stress for instance.

  14. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation) at Thessaloniki, Greece

    OpenAIRE

    Lindfors, A. V.; Kouremeti, N.; Arola, A.; Kazadzis, S.; Bais, A. F.; Laaksonen, A.

    2013-01-01

    Pyranometer measurements of the solar surface radiation (SSR) are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD) using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, w...

  15. Optical Fibre Temperature Sensor Based On A Blackbody Radiation

    Science.gov (United States)

    Hypszer, Ryszard; Plucinski, Jerzy; Wierzba, Henryk J.

    1990-01-01

    The principle of operation of the fibre optical temperature sensor based on a blackbody radiation and its construction model is given in the paper. A quartz rod of 0.6 mm diameter and 20 cm length with a blackbody cavity at the one end was used to construct the sensor. The cavity was made by vacuum evaporation of a chromium layer and a silicone monooxide layer was used as a protection. Infrared radiation is transmitted by the fibre optic to the detection circuit. This sensor enables temperature measurement from 400 to 1200°C. The range of measurement is determined by the detection sensitivity and by rod softening. The resolution is of the order of 10-2°C. The sensor calibration was done by using PtRh1O-Pt thermocouple.

  16. Optical components and systems for synchrotron radiation: an introduction

    International Nuclear Information System (INIS)

    Howells, M.R.

    1981-01-01

    A brief description of the nature and origins of synchrotron radiation is given with special reference to its geometrical optical properties and the use of storage rings as light souces. The geographical distribution of SR sources in the world is reviewed and some discussion of the level of experimental activity is given. Estimates of future levels of experimental activity are also made both for existing storage rings and those planned for the future. Calculations of the approximate number of mirrors and gratings that will be required are offered. Some general considerations are outlined showing how synchrotron radiation optical systems couple to the light source and indicating which parameters need to be maximized for best overall performance

  17. Grazing incidence infrared reflectivity of La1.85Sr0.15CuO4 and NbN

    NARCIS (Netherlands)

    Somal, HS; Feenstra, BJ; Schutzmann, J; Kim, JH; Barber, ZH; Duijn, VHM; Hien, NT; Menovsky, AA; Palumbo, M; vanderMarel, D

    1996-01-01

    Infrared reflectivity measurements, using p-polarized light at a grazing angle of incidence, show an increased sensitivity to the optical conductivity of highly reflecting superconducting materials. We demonstrate that when this measurement technique is applied to the conventional s-wave

  18. A Radiation Dosimetry Method Using Pulsed Optically Stimulated Luminescence

    International Nuclear Information System (INIS)

    Akselrod, M.S.; McKeever, S.W.S.

    1999-01-01

    A method for the determination of absorbed radiation dose is described based on pulsed optically stimulated luminescence (POSL). The method relies upon the stimulation of an irradiated sample with a train of light pulses from a suitable light source (e.g. a laser) using a wavelength which is within the range of wavelengths corresponding to the radiation-induced optical absorption in the irradiated sample. The subsequent emitted light, due to the detrapping of trapped charges and their subsequent recombination with charge of the opposite sign, is synchronously detected in the period between each stimulation pulse. The total luminescence is summed over the desired number of stimulation pulses and this forms the measured POSL signal. By monitoring the emitted light only in the period between stimulation pulses one can reduce the optical filtering required to discriminate between the stimulation light and the emission light; in this way a high measurement efficiency, and, therefore, a high radiation sensitivity (luminescence intensity per unit absorbed dose) is achieved. Key parameters in the method are the intrinsic luminescence lifetime for the material being used as the luminescent detector, the width of the optical stimulation pulse, and the period between pulses. For optimum operation the measurement parameters should be such that both the pulse width and the time between pulses are much less than the luminescence lifetime. By appropriate choice of the power of the optical stimulation, the frequency of the stimulation pulses, and the total stimulation period, one can also re-measure the absorbed dose several times. In this way, a re-read capability is available with the procedure. The method is illustrated using light from a 2nd-harmonic Nd:YAG laser, with irradiated, anion-deficient aluminium oxide as the luminescent detector material. (author)

  19. Optical properties of the PANDA barrel DIRC radiator bars

    Energy Technology Data Exchange (ETDEWEB)

    Kalicy, Grzegorz; Krebs, Marvin; Peters, Klaus [GSI, Darmstadt (Germany); Goethe Universitaet, Frankfurt (Germany); Schwarz, Carsten; Schwiening, Jochen [GSI, Darmstadt (Germany); Collaboration: PANDA-Collaboration

    2015-07-01

    The PANDA experiment at the Facility for Antiproton and Ion Research in Europe (FAIR) at GSI, Darmstadt, will study fundamental questions of hadron physics and QCD. A fast focusing DIRC (Detection of Internally Reflected Cherenkov light) counter will provide hadronic particle identification (PID) in the barrel region of the PANDA detector. To meet the PID requirements, the Barrel DIRC has to provide precise measurements of the Cherenkov angle, which is conserved for Cherenkov photons propagating through the radiator by total internal reflection. The radiators, rectangular bars made from fused silica, have to fulfill very strict optical and mechanical requirements. This includes the squareness and parallelism of the sides of the bars, sharp corners, and a very smooth surface polish, ensuring that the Cherenkov photons reach the optical sensors without angular distortions. Currently the Barrel DIRC is at the final design stage and several different bar shapes and fabrication methods are being considered for the final detector. An optical setup, consisting of a computer-controlled positioning and a multi-wavelength laser system, is used to evaluate the radiator bars to obtain critical values like transmittance and reflectivity. The current results and techniques are presented on this poster.

  20. Modulatable optical radiators and metasurfaces based on quantum nanoantennas

    KAUST Repository

    Chen, Pai-Yen; Farhat, Mohamed

    2015-01-01

    We investigate the tunable and switchable optical radiators and metamaterials formed by metallic nanodipole antennas with submicroscopic gaps (1.2 nm), of which linear and third-order nonlinear quantum conductivities are observed due to the photon-assisted tunneling effect. The quantum conductivities induced at the nanogap are relevant to power dissipations, which can be enhanced by the strongly localized optical fields associated with the plasmonic resonance. We demonstrate that the scattering property of an individual quantum nanoantenna and the transparency of a metamasurface constituted of it can be tuned by electrostatically controlling the linear conductivity (electronic tuning) or by adjusting the irradiation intensity that varies the nonlinear quantum conductivity (all-optical tuning).

  1. Modulatable optical radiators and metasurfaces based on quantum nanoantennas

    KAUST Repository

    Chen, Pai-Yen

    2015-01-20

    We investigate the tunable and switchable optical radiators and metamaterials formed by metallic nanodipole antennas with submicroscopic gaps (1.2 nm), of which linear and third-order nonlinear quantum conductivities are observed due to the photon-assisted tunneling effect. The quantum conductivities induced at the nanogap are relevant to power dissipations, which can be enhanced by the strongly localized optical fields associated with the plasmonic resonance. We demonstrate that the scattering property of an individual quantum nanoantenna and the transparency of a metamasurface constituted of it can be tuned by electrostatically controlling the linear conductivity (electronic tuning) or by adjusting the irradiation intensity that varies the nonlinear quantum conductivity (all-optical tuning).

  2. Fiber-optic-coupled dosemeter for remote optical sensing of radiation

    International Nuclear Information System (INIS)

    Justus, B.L.; Huston, A.L.

    1996-01-01

    Remote sensing technologies for the detection and measurement of ionizing radiation exposure are of current interest for applications such as patient dose verification during radiotherapy and the monitoring of environmental contaminants. Fiberoptic-based sensing is attractive due to the advantages of small size, low cost, long life and freedom from electromagnetic interference. Several fiberoptic-based radiation sensing systems have been described that utilize radiation induced changes in the optical characteristics of the fiber such as reduced transmission as a result of darkening of the glass, optical phase shifts due to heating, or changes in the birefringence of a polarization-maintaining fiber. The measurement of radiation induced darkening is limited in both sensitivity and dynamic range and requires long fiber lengths. Phase shift measurements require the use of single-mode lasers, phase sensitive interferometric detection, long fiber lengths and complex signal processing techniques. Alternatively, thermoluminescent (TL) phosphor powders have been coated onto fiberoptic cables and remote dosimetry measurements performed using traditional laser heating techniques. The sensitivity is limited by the requirement for a very thin layer of phosphor material, due to problems associated with light scattering and efficient heating by thermal diffusion. In this paper we report the development of an all-optical, fiber-optic-coupled, thermoluminescence dosemeter for remote radiation sensing that offers significant advantages compared to previous technologies. We recently reported the development of an optically transparent, TL glass material having exceptionally good characteristics for traditional dosimetry applications. We also reported a modified TL glass incorporating a rare earth ion dopant in order to absorb light from a semiconductor laser and utilize the absorbed light energy to internally heat the glass and release the trapped electrons. (author)

  3. X-ray grazing incidence studies of the 2D crystallization of monolayers of 1-alcohols at the air water interface

    DEFF Research Database (Denmark)

    Legrand, J.F.; Renault, A.; Konovalov, O.

    1994-01-01

    A new undulator producing an X-ray beam of high brilliance has been used at the European Synchrotron Radiation Facility (ESRF, Beamline-9, Troika) for investigating the structure of two-dimensional crystals of 1-tetradecanol, 1-dodecanol, 1-decanol and 1-nonanol. These fatty alcohols with relativ...

  4. Development of a distributed radiation detection system using optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, F; Inouchi, Goro; Takada, Eiji; Takahashi, Hiroyuki; Iguchi, Tetsuo; Nakazawa, Masaharu [Tokyo Univ. (Japan). Faculty of Engineering; Kakuta, Tsunemi

    1996-07-01

    We have confirmed the importance of temperature and dose rate for the response of Ge-doped fibers to radiation. A phenomenological model have been found to account for temperature and dose rate effects. From this model it is possible to make dose predictions from attenuation measurements when the temperature and dose rate are known. Ge-doped fibers have been found to have a relatively low sensitivity to both neutron and gamma radiation. In addition, temperature and dose rate dependencies complicate the analysis. However we point out that these problems may all be solved if we use fibers, such as P-doped fibers, which contain color centers of long lifetime. This would remove both the temperature and dose rate dependencies that complicate the use of Ge-doped fibers, in addition the radiation sensitivity is increased. Finally OTDR has been investigated as a possible read-out method for distributed radiation measurements. For our system the minimum pulse length was 3ns, giving a spatial resolution in the meter range and a response length to radiation of about 10 m if accurate dose values where to be obtained. We found OTDR to be a suitable method for radiation induced attenuation measurements in optical fibers, especially for long fiber lengths and long time scales where questions of light source stability becomes important for other systems. (S.Y.)

  5. High power beam profile monitor with optical transition radiation

    International Nuclear Information System (INIS)

    Denard, J.C.; Piot, P.; Capek, K.; Feldl, E.

    1997-01-01

    A simple monitor has been built to measure the profile of the high power beam (800 kW) delivered by the CEBAF accelerator at Jefferson Lab. The monitor uses the optical part of the forward transition radiation emitted from a thin carbon foil. The small beam size to be measured, about 100 μm, is challenging not only for the power density involved but also for the resolution the instrument must achieve. An important part of the beam instrumentation community believes the radiation being emitted into a cone of characteristic angle 1/γ is originated from a region of transverse dimension roughly λγ; thus the apparent size of the source of transition radiation would become very large for highly relativistic particles. This monitor measures 100 μm beam sizes that are much smaller than the 3.2 mm λγ limit; it confirms the statement of Rule and Fiorito that optical transition radiation can be used to image small beams at high energy. The present paper describes the instrument and its performance. The authors tested the foil in, up to 180 μA of CW beam without causing noticeable beam loss, even at 800 MeV, the lowest CEBAF energy

  6. Radiation - induced changes in the optical properties of hemoglobin molecule

    International Nuclear Information System (INIS)

    Selim, N.S; El-Marakby, S.M.

    2009-01-01

    Adult male albino rats were exposed to different doses of gamma radiation from Cs-137 source. Hemoglobin samples were analyzed 24 hrs after irradiation. The UV-visible spectrum of hemoglobin molecule was measured in the range 200 to 700 nm. The overall spectrum of the hemoglobin molecule showed hypochromicity that increased with dose increase. To investigate the effect of radiation on the hemoglobin molecule, different parameters of the spectrum were calculated: molar absorption coefficient, absorption cross section, transition dipole moment , dipole length, the optical energy gap and activation energy for each characteristic peak. The obtained results revealed that the radiation effect can induce rearrangement of the transition dipole moments and change molecular energy levels of the hemoglobin molecule

  7. Radiation imaging with optically read out GEM-based detectors

    Science.gov (United States)

    Brunbauer, F. M.; Lupberger, M.; Oliveri, E.; Resnati, F.; Ropelewski, L.; Streli, C.; Thuiner, P.; van Stenis, M.

    2018-02-01

    Modern imaging sensors allow for high granularity optical readout of radiation detectors such as MicroPattern Gaseous Detectors (MPGDs). Taking advantage of the high signal amplification factors achievable by MPGD technologies such as Gaseous Electron Multipliers (GEMs), highly sensitive detectors can be realised and employing gas mixtures with strong scintillation yield in the visible wavelength regime, optical readout of such detectors can provide high-resolution event representations. Applications from X-ray imaging to fluoroscopy and tomography profit from the good spatial resolution of optical readout and the possibility to obtain images without the need for extensive reconstruction. Sensitivity to low-energy X-rays and energy resolution permit energy resolved imaging and material distinction in X-ray fluorescence measurements. Additionally, the low material budget of gaseous detectors and the possibility to couple scintillation light to imaging sensors via fibres or mirrors makes optically read out GEMs an ideal candidate for beam monitoring detectors in high energy physics as well as radiotherapy. We present applications and achievements of optically read out GEM-based detectors including high spatial resolution imaging and X-ray fluorescence measurements as an alternative readout approach for MPGDs. A detector concept for low intensity applications such as X-ray crystallography, which maximises detection efficiency with a thick conversion region but mitigates parallax-induced broadening is presented and beam monitoring capabilities of optical readout are explored. Augmenting high resolution 2D projections of particle tracks obtained with optical readout with timing information from fast photon detectors or transparent anodes for charge readout, 3D reconstruction of particle trajectories can be performed and permits the realisation of optically read out time projection chambers. Combining readily available high performance imaging sensors with compatible

  8. Thin film and multilayer optics for XUV spectral domain (1 nm to 60 nm)

    International Nuclear Information System (INIS)

    Delmotte, Franck

    2010-02-01

    The XUV spectral domain (1-60 nm wavelength range) has experienced rapid growth in recent years. On one side, the sources (synchrotron radiation, harmonic generation, x-ray laser, free-electron laser...) require ever more efficient optics, on the other hand, applications (diagnostics of hot plasma, solar physics, x-ray microscopy, EUV lithography, x-ray analysis...) provide new constraints on the design of multilayer stacks. The multilayer mirrors are the only way to achieve efficient optics operating at non-grazing incidence angles in this spectral range. Our work within the team XUV Optics at Laboratoire Charles Fabry de l'Institut d'Optique focuses on the study of materials in thin layers correlated to the study of optical properties of multilayers. The objective is to achieve new multilayer components previously unavailable in the XUV domain, through a better understanding of physical phenomena in these nano-layer stacks. We show through several examples of how we have managed both to improve the performance of multilayer mirrors in a broad spectral range, and secondly, to develop new optical functions: beam splitters, broadband mirrors, dual-band mirrors or phase compensation mirrors. (author)

  9. Irradiation behavior of developed radiation resistance optical-fibers and observed optical radiation from their SiO2 cores under reactor irradiation

    International Nuclear Information System (INIS)

    Shikama, Tatsuo; Narui, Minoru; Kayano, Hideo; Kakuta, Tsunemi; Sagawa, Tsutomu; Sanada, Kazuo; Shamoto, Naoki; Uramoto, Toshimasa.

    1994-01-01

    Two kinds of optical fibers were irradiated in a fission reactor, JMTR(Japan Materials Testing Reactor), up to a 1.55x10 19 n/cm 2 fast neutron fluence and a 3.3x10 9 Gy ionizing dose at 370K. Optical transmission spectra were measured in the wavelength range of 450-1750nm, in-situ. Growth of strong optical absorption bands were observed in the range of wavelength shorter than 750nm. In the meantime, the fibers showed good radiation-resistance in the range of wavelength longer than 750nm. Optical radiations were observed from SiO 2 optical fibers under irradiation. A major part of the observed optical radiations is thought to be composed of broad optical radiation in the whole wavelength range studied in the present experiment. This broad optical radiation will be generated by the process of so-called Cerenkov radiation. Also, a sharp optical radiation peak was found at 1270nm on a F-doped fiber. This peak is thought to relate with doped Fluorine ions and ionizing gamma-ray irradiation. (author)

  10. Feasibility Study on Fiber-optic Radiation Sensor for Remote Gamma-ray Spectroscopy

    International Nuclear Information System (INIS)

    Jeon, Hyesu; Jang, Kyoung Won; Shin, Sang Hun and others

    2014-01-01

    In this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors. As a result, the BGO was suitable for the sensing probe of fiber-optic radiation sensor due to its high scintillation output and exact photoelectric peak for the gamma-ray energy. The basic principle of radiation detection is to detect the signals caused by interactions between radiations and materials. There are various types of radiation detectors depending on types of radiation to be detected and physical quantities to be measured. As one of the radiation detectors, a fiber-optic radiation sensor using a scintillator and an optical fiber has two advantages such as no space restraint and remote sensing. Moreover, in nuclear environments, this kind of sensor has immunities for electromagnetic field, temperature, and pressure. Thus, the fiber-optic radiation sensor can be used in various fields including nondestructive inspection, radioactive waste management, nuclear safety, radiodiagnosis and radiation therapy. As a fundamental study of the fiber-optic radiation sensor for remote gamma-ray spectroscopy, in this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors

  11. Nuclear radiation detected optical pumping of neutron deficient Hg isotopes

    International Nuclear Information System (INIS)

    Bonn, J.

    1975-01-01

    The extension of the Nuclear Radiation Detected Optical Pumping method to mass-separated samples of isotopes far off stability is presented for a series of light Hg isotopes produced at the ISOLDE facility at CERN. The isotope under investigation is transferred by an automatic transfer system into the optical pumping apparatus. Zeeman scanning of an isotopically pure Hg spectral lamp is used to reach energetic coincidence with the hyperfine structure components of the 6s 2 1 S 0 -6s6p 3 P 1 (lambda = 2537 A) resonance line of the investigated isotope and the Hg lamp. The orientation build up by optical pumping is monitored via the asymmetry or anisotropy of the nuclear radiation. Nuclear spins, magnetic moments, electric quadrupole moments and isotopic shift are obtained for 181 Hg- 191 Hg using the β-asymmetry as detector. The extension of the method using the γ-anisotropy is discussed and measurements on 193 Hg are presented. (orig./HK)

  12. Optical transition radiation interferometry for A0 photoinjector

    International Nuclear Information System (INIS)

    Kazakevich, G.; Novosibirsk, IYF; Edwards, H.; Fliller, R.; Lebedev, V.; Nagaitsev, S.; Santucci, J.; Thurman-Keup, R.; Fermilab; Piot, P.; Fermilab; Northern Illinois U.; Li, J.; Tikhoplav, R.; UCLA

    2007-01-01

    A charged particle passing through the boundary of two medias with different permittivity values generates Transition Radiation (TR), [1]. The TR is caused by a variation of the particle electric field with variation of the permittivity. The TR for relativistic particles has a wide spectrum with a significant portion in the optical range. The Optical Transition Radiation (OTR) is widely used for a beam profile monitoring and measurements of a beam size. Moreover, OTR can be used to characterize the energy, energy spread and transverse angles in the beam by employing the interference of the OTR from two thin films [2] inserted in the beam trajectory. This method has been applied in number of works [3-5] demonstrating high results and good coincidence in measurements and calculations. In this paper we present and discuss in details a simulation of the interference pattern in several experimental setups. We consider the main optical effects, for diagnostics for the beam properties at A0 Photoinjector and the ILC module test area (NML) in a wide range of electron beam energy. In this paper, we first derive the OTR intensity formula for a single film at 90 degrees to the beam, then for two films at normal incidence, and finally with films at 45 degree incidence to the beam. The last section illustrates application with beam parameters like those at the A0 Photoinjector (electron energy 15 MeV)

  13. Early bilateral radiation-induced optic neuropathy with follow-up MRI

    International Nuclear Information System (INIS)

    McClellan, R.L.; El Gammal, T.; Kline, L.B.

    1995-01-01

    Most documented cases of radiation-induced optic neuropathy are unilateral and occur more than 1 year after radiotherapy to the sellar region. We describe a patient with bilateral radiation optic neuropathy 3 months following the completion of radiotherapy. MRI 13 months after the onset of visual failure showed bilateral optic atrophy with residual gadolinium enhancement. (orig.)

  14. Early bilateral radiation-induced optic neuropathy with follow-up MRI

    Energy Technology Data Exchange (ETDEWEB)

    McClellan, R.L. [Alabama Univ., Birmingham (United States). Dept. of Radiology; El Gammal, T. [Alabama Univ., Birmingham (United States). Dept. of Radiology; Kline, L.B. [Alabama Univ., Birmingham (United States). Dept. of Radiology

    1995-02-01

    Most documented cases of radiation-induced optic neuropathy are unilateral and occur more than 1 year after radiotherapy to the sellar region. We describe a patient with bilateral radiation optic neuropathy 3 months following the completion of radiotherapy. MRI 13 months after the onset of visual failure showed bilateral optic atrophy with residual gadolinium enhancement. (orig.)

  15. Evaluation of acute radiation optic neuropathy by B-scan ultrasonography

    International Nuclear Information System (INIS)

    Lovato, A.A.; Char, D.H.; Quivey, J.M.; Castro, J.R.

    1990-01-01

    We studied the accuracy of B-scan ultrasonography to diagnose radiation-induced optic neuropathy in 15 patients with uveal melanoma. Optic neuropathy was diagnosed by an observer masked as to clinical and photographic data. We analyzed planimetry area measurements of the retrobulbar nerve before and after irradiation. The retrobulbar area of the optic nerve shadow on B-scan was quantitated with a sonic digitizer. Increased optic nerve shadow area was confirmed in 13 of 15 patients who had radiation optic neuropathy (P less than .004). The correct diagnosis was confirmed when the results of ultrasound were compared to fundus photography and fluorescein angiography. In 13 patients there was acute radiation optic neuropathy. Two patients did not show an enlarged retrobulbar optic nerve, and the clinical appearance suggested early progression to optic atrophy. Ultrasonography documents the enlargement of the optic nerve caused by acute radiation changes

  16. Studies on strain relaxation of La{sub 0.5}Ba{sub 0.5}MnO{sub 3} film by normal and grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haiou [Hangzhou Dianzi University, Institute of Materials Physics, Hangzhou (China); Tan, Weishi [Hunan City University, College of Communication and Electronic Engineering, Yiyang (China); Nanjing University of Science and Technology, Key Laboratory of Soft Chemistry and Functional Materials, Department of Applied Physics, Ministry of Education, Nanjing (China); Liu, Hao [Suzhou Institute of Industrial Technology, Department of Electronic and Communication Engineering, Suzhou (China); Cao, Mengxiong; Wang, Xingyu; Ma, Chunlin [Nanjing University of Science and Technology, Key Laboratory of Soft Chemistry and Functional Materials, Department of Applied Physics, Ministry of Education, Nanjing (China); Jia, Quanjie [The Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China)

    2017-03-15

    Perovskite manganite La{sub 0.5}Ba{sub 0.5}MnO{sub 3} (LBMO) films were deposited on (001)-oriented single-crystal SrTiO{sub 3} (STO) substrates by pulsed laser deposition. High-resolution X-ray diffraction and grazing incidence X-ray diffraction techniques were applied to characterize the crystal structure and lattice strain of LBMO films. The in-plane and out-of-plane growth orientations of LBMO films with respect to substrate surface have been studied. The epitaxial orientation relationship LBMO (001) [100] //STO (001) [100] exists at the LBMO/STO interface. The lattice strain of LBMO film begins to relax with the thickness of LBMO film up to 12 nm. When the thickness is further increased up to 43 nm, the film is in fully strain-relaxed state. Jahn-Teller strain plays an important role in LBMO/STO system. The mechanism for strain relaxation is in accordance with that of tetragonal distortion. (orig.)

  17. Impact of Lipid Oxidization on Vertical Structures and Electrostatics of Phospholipid Monolayers Revealed by Combination of Specular X-ray Reflectivity and Grazing-Incidence X-ray Fluorescence.

    Science.gov (United States)

    Korytowski, Agatha; Abuillan, Wasim; Makky, Ali; Konovalov, Oleg; Tanaka, Motomu

    2015-07-30

    The influence of phospholipid oxidization of floating monolayers on the structure perpendicular to the global plane and on the density profiles of ions near the lipid monolayer has been investigated by a combination of grazing incidence X-ray fluorescence (GIXF) and specular X-ray reflectivity (XRR). Systematic variation of the composition of the floating monolayers unravels changes in the thickness, roughness and electron density of the lipid monolayers as a function of molar fraction of oxidized phospholipids. Simultaneous GIXF measurements enable one to qualitatively determine the element-specific density profiles of monovalent (K(+) or Cs(+)) and divalent ions (Ca(2+)) in the vicinity of the interface in the presence and absence of two types of oxidized phospholipids (PazePC and PoxnoPC) with high spatial accuracy (±5 Å). We found the condensation of Ca(2+) near carboxylated PazePC was more pronounced compared to PoxnoPC with an aldehyde group. In contrast, the condensation of monovalent ions could hardly be detected even for pure oxidized phospholipid monolayers. Moreover, pure phospholipid monolayers exhibited almost no ion specific condensation near the interface. The quantitative studies with well-defined floating monolayers revealed how the elevation of lipid oxidization level alters the structures and functions of cell membranes.

  18. Surface morphology of vacuum-evaporated pentacene film on Si substrate studied by in situ grazing-incidence small-angle X-ray scattering: I. The initial stage of formation of pentacene film

    Science.gov (United States)

    Hirosawa, Ichiro; Watanabe, Takeshi; Koganezawa, Tomoyuki; Kikuchi, Mamoru; Yoshimoto, Noriyuki

    2018-03-01

    The progress of the surface morphology of a growing sub-monolayered pentacene film on a Si substrate was studied by in situ grazing-incidence small angle X-ray scattering (GISAXS). The observed GISAXS profiles did not show sizes of pentacene islands but mainly protuberances on the boundaries around pentacene film. Scattering of X-ray by residual pits in the pentacene film was also detected in the GISAXS profiles of an almost fully covered film. The average radius of pentacene protuberances increased from 13 to 24 nm as the coverage increased to 0.83 monolayer, and the most frequent radius was almost constant at approximately 9 nm. This result suggests that the population of larger protuberances increase with increasing lengths of boundaries of the pentacene film. It can also be considered that the detected protuberances were crystallites of pentacene, since the average size of protuberances was nearly equal to crystallite sizes of pentacene films. The almost constant characteristic distance of 610 nm and amplitudes of pair correlation functions at low coverages suggest that the growth of pentacene films obeyed the diffusion-limited aggregation (DLA) model, as previously reported. It is also considered that the sites of islands show a triangular distribution for small variations of estimated correlation distances.

  19. Nanofocusing optics for synchrotron radiation made from polycrystalline diamond.

    Science.gov (United States)

    Fox, O J L; Alianelli, L; Malik, A M; Pape, I; May, P W; Sawhney, K J S

    2014-04-07

    Diamond possesses many extreme properties that make it an ideal material for fabricating nanofocusing x-ray optics. Refractive lenses made from diamond are able to focus x-ray radiation with high efficiency but without compromising the brilliance of the beam. Electron-beam lithography and deep reactive-ion etching of silicon substrates have been used in a transfer-molding technique to fabricate diamond optics with vertical and smooth sidewalls. Latest generation compound refractive lenses have seen an improvement in the quality and uniformity of the optical structures, resulting in an increase in their focusing ability. Synchrotron beamline tests of two recent lens arrays, corresponding to two different diamond morphologies, are described. Focal line-widths down to 210 nm, using a nanocrystalline diamond lens array and a beam energy of E = 11 keV, and 230 nm, using a microcrystalline diamond lens at E = 15 keV, have been measured using the Diamond Light Source Ltd. B16 beamline. This focusing prowess is combined with relatively high transmission through the lenses compared with silicon refractive designs and other diffractive optics.

  20. How to obtain traceability on optical radiation measurements?

    Science.gov (United States)

    Matamoros García, Carlos H.

    2006-02-01

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

  1. Cloud-radiation interactions - Effects of cirrus optical thickness feedbacks

    Science.gov (United States)

    Somerville, Richard C. J.; Iacobellis, Sam

    1987-01-01

    The paper is concerned with a cloud-radiation feedback mechanism which may be an important component of the climate changes expected from increased atmospheric concentrations of carbon dioxide and other trace greenhouse gases. A major result of the study is that cirrus cloud optical thickness feedbacks may indeed tend to increase the surface warming due to trace gas increases. However, the positive feedback from cirrus appears to be generally weaker than the negative effects due to lower clouds. The results just confirm those of earlier research indicating that the net effect of cloud optical thickness feedbacks may be a negative feedback which may substantially (by a factor of about 2) reduce the surface warming due to the doubling of CO2, even in the presence of cirrus clouds.

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

    Science.gov (United States)

    Karl JR., Robert R.

    1990-03-06

    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.

  3. [Occupational risk related to optical radiation exposure in construction workers].

    Science.gov (United States)

    Gobba, F; Modenese, A

    2012-01-01

    Optical Radiation is a relevant occupational risk in construction workers, mainly as a consequence of the exposure to the ultraviolet (UV) component of solar radiation (SR). Available data show that UV occupational limits are frequently exceeded in these workers, resulting in an increased occupational risk of various acute and chronic effects, mainly to skin and to the eye. One of the foremost is the carcinogenic effect: SR is indeed included in Group 1 IARC (carcinogenic to humans). UV exposure is related to an increase of the incidence of basal cell carcinoma, squamous cell carcinoma of the skin and cutaneous malignant melanoma (CMM). The incidence of these tumors, especially CMM, is constantly increasing in Caucasians in the last 50 years. As a conclusion, an adequate evaluation of the occupational risk related to SR, and adequate preventive measures are essential in construction workers. The role of occupational physicians in prevention is fundamental.

  4. Passive radiation detection using optically active CMOS sensors

    Science.gov (United States)

    Dosiek, Luke; Schalk, Patrick D.

    2013-05-01

    Recently, there have been a number of small-scale and hobbyist successes in employing commodity CMOS-based camera sensors for radiation detection. For example, several smartphone applications initially developed for use in areas near the Fukushima nuclear disaster are capable of detecting radiation using a cell phone camera, provided opaque tape is placed over the lens. In all current useful implementations, it is required that the sensor not be exposed to visible light. We seek to build a system that does not have this restriction. While building such a system would require sophisticated signal processing, it would nevertheless provide great benefits. In addition to fulfilling their primary function of image capture, cameras would also be able to detect unknown radiation sources even when the danger is considered to be low or non-existent. By experimentally profiling the image artifacts generated by gamma ray and β particle impacts, algorithms are developed to identify the unique features of radiation exposure, while discarding optical interaction and thermal noise effects. Preliminary results focus on achieving this goal in a laboratory setting, without regard to integration time or computational complexity. However, future work will seek to address these additional issues.

  5. Evaluation of a digital optical ionizing radiation particle track detector

    International Nuclear Information System (INIS)

    Hunter, S.R.

    1987-06-01

    An ionizing radiation particle track detector is outlined which can, in principle, determine the three-dimensional spatial distribution of all the secondary electrons produced by the passage of ionizing radiation through a low-pressure (0.1 to 10 kPa) gas. The electrons in the particle track are excited by the presence of a high-frequency AC electric field, and two digital cameras image the optical radiation produced in electronic excitation collisions of the surroundings gas by the electrons. The specific requirements of the detector for neutron dosimetry and microdosimetry are outlined (i.e., operating conditions of the digital cameras, high voltage fields, gas mixtures, etc.) along with an estimate of the resolution and sensitivity achievable with this technique. The proposed detector is shown to compare favorable with other methods for obtaining the details of the track structure, particularly in the quality of the information obtainable about the particle track and the comparative simplicity and adaptability of the detector for measuring the secondary electron track structure for many forms of ionizing radiation over a wide range of energies

  6. Tuning optical radiation for visual and nonvisual impact

    Science.gov (United States)

    Royer, Michael P.

    2011-12-01

    Spectral tuning---the allocation of radiant energy emitted by a lamp---is a fundamental element of illuminating engineering. Proper placement of optical radiation allows for reduced energy consumption, increased brightness perception, and improved color rendition. It can also result in lamps that have a greater impact on nonvisual human functions such as circadian rhythms, sleep, mood, and cognition. For an architectural lighting system, careful consideration must be given to all of these areas; recent advancements in understanding nonvisual photoreception must be balanced with the traditional emphasis on visual quality and energy efficiency. The three research projects described herein investigated spectral tuning by examining the effects of optical radiation or seeking ideal spectral power distributions. In all three cases, emphasis was placed on developing an architectural lighting system based on red, green, and blue (RGB) light emitting diodes (LEDs) that is capable of providing maximum stimulation to nonvisual systems while maintaining visual quality standards. In particular, the elderly were considered as a target population because they have an increased risk of developing disorders linked to illumination deficits. The three endeavors can be summarized as follows: Light Therapy for Seniors in Long-term Care AIM: To examine the effect of optical radiation on circadian rhythms, sleep, mood, and cognition for frail elderly in a long-term care environment. METHODOLOGY: A double-blind, placebo-controlled clinical trial of light therapy was conducted using circadian-effective short-wavelength (blue) optical radiation to treat a sample of residents recruited for participation without bias for existing medical diagnoses. KEY FINDINGS: Light therapy treatment improved cognitive functioning compared to placebo but no changes were detected in nighttime sleep statistics, reports of daytime sleepiness, circadian rhythms, or depression inventory parameters. Perceived

  7. Study of optically stimulated luminescence (OSL) for radiation detection. Application to an optical fibre γ-radiation sensor

    International Nuclear Information System (INIS)

    Roy, O.

    1998-01-01

    This work shows up the usefulness of the Optically Stimulated Luminescence (OSL) to resolve radioprotection problems. We study the use of OSL as a gamma dosimetric technique with respect to the ALARA's concept (As Low As Reasonably Achievable). A new approach based on optical fibers and luminescent materials showing OSL properties (closely related to Thermoluminescence phenomena) is presented in order to improve the remote real time dosimetry monitoring. Like thermoluminescent materials (TLD), OSL materials can trap charges under an irradiation (UV, X, γ,...). Instead of heating, the charges trapped are released by light stimulation and produce a visible luminescence which amount is proportional to trap the 'data stored' left by irradiation, enabling the dose measurement. The OSL phenomenon offers the same advantages as TLD plus the interesting possibility of a remote optical stimulation. The end-user objective deals with the development of a γ-radiation Optical FIber Sensor (OFS) for dose measurement which can offer new functionalities based on OSL materials coupled with an optical fiber. Rare earth doped Alkaline Earth Sulphides (AES), BAFX:EU 2+ (X = Cl, Br, I) and halogen alkaline have been studied (crystalline form, synthesis techniques, influence of dopants and color centers). Their characteristics are presented and extensively discussed. A specific experimental set-up to characterise various OSL phosphors has been developed. It allows the study of sensitivity, linearity, time decay behaviour of OSL signal and zeroing time. A joint study of OSL and TL has shown the technical limitations as well as the thermal fading and the origin of the long zeroing time. An Optical Fiber Sensor (OFS) based on OSL and using MgS:Sm has been developed for practical applications on nuclear fields. Its specifications are presented and discussed, moreover improvements are proposed. (author)

  8. Advances in thin film diffraction instrumentation by X-ray optics

    International Nuclear Information System (INIS)

    Haase, A.

    1996-01-01

    The structural characterisation of thin films requires a parallel X-ray beam of high intensity. Parallel beam geometry is commonly used in high resolution and single crystal experiments, but also in the field of X-ray diffraction for polycrystalline material (e.g. in phase, texture and stress analysis). For grazing incidence diffraction (GID), the use of small slits on the primary side and of long soller slits with a flat monochromator on the secondary side is standard. New optical elements have been introduced with polychromatic or monochromatic radiation. By means of different applications the results are compared with those of classical beam optics. X-ray fiber optics utilize total external reflection of X-rays on smooth surfaces. Effects of monochromatization are presented. In many fields of application, fiber optics may replace conventional collimators. The use of primary and secondary channel cut crystals can also produce a high parallel monochromatic X-ray beam. A parabolically bent graded multilayer produces a monochromatic parallel beam of high intensity. Compared with classical Bragg-Brentano (focussing) geometry, excellent results have been obtained, especially for samples with an irregular shape. In combination with a channel cut monochromator there is a substantial gain in intensity leading to an increase of the dynamic intensity range of rocking curves

  9. Advances in thin film diffraction instrumentation by X-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    Haase, A [Rich. Seifert and Co., Analytical X-ray Systems, Ahrensburg (Germany)

    1996-09-01

    The structural characterisation of thin films requires a parallel X-ray beam of high intensity. Parallel beam geometry is commonly used in high resolution and single crystal experiments, but also in the field of X-ray diffraction for polycrystalline material (e.g. in phase, texture and stress analysis). For grazing incidence diffraction (GID), the use of small slits on the primary side and of long soller slits with a flat monochromator on the secondary side is standard. New optical elements have been introduced with polychromatic or monochromatic radiation. By means of different applications the results are compared with those of classical beam optics. X-ray fiber optics utilize total external reflection of X-rays on smooth surfaces. Effects of monochromatization are presented. In many fields of application, fiber optics may replace conventional collimators. The use of primary and secondary channel cut crystals can also produce a high parallel monochromatic X-ray beam. A parabolically bent graded multilayer produces a monochromatic parallel beam of high intensity. Compared with classical Bragg-Brentano (focussing) geometry, excellent results have been obtained, especially for samples with an irregular shape. In combination with a channel cut monochromator there is a substantial gain in intensity leading to an increase of the dynamic intensity range of rocking curves.

  10. Optical characterization of OLED emitter properties by radiation pattern analyses

    Energy Technology Data Exchange (ETDEWEB)

    Flaemmich, Michael

    2011-09-08

    Researches in both, academia and industry are investigating optical loss channels in OLED layered systems by means of optical simulation tools in order to derive promising concepts for a further enhancement of the overall device performance. Besides other factors, the prospects of success of such optimization strategies rely severely on the credibility of the optical input data. The present thesis provides a guideline to measure the active optical properties of OLED emitter materials in situ by radiation pattern analyses. Reliable and widely applicable methods are introduced to determine the internal electroluminescence spectrum, the profile of the emission zone, the dipole emitter orientation, and the internal luminescence quantum efficiency of emissive materials from the optical far field emission of OLEDs in electrical operation. The proposed characterization procedures are applied to sets of OLEDs containing both, fluorescent polymeric materials as well as phosphorescent small-molecular emitters, respectively. On the one hand, quite expected results are obtained. On the other hand, several novel and truly surprising results are found. Most importantly, this thesis contains the first report of a non-isotropic, mainly parallel emitter orientation in a phosphorescent small-molecular guest-host system (Ir(MDQ)2(acac) in a-NPD). Due to the latter result, emitter orientation based optimization of phosphorescent OLEDs seems to be within reach. Since parallel dipoles emit preferably into air, the utilization of smart emissive materials with advantageous molecular orientation is capable to boost the efficiency of phosphorescent OLEDs by 50%. Materials design, the influence of the matrix material and the substrate, as well as film deposition conditions are just a few parameters that need to be studied further in order to exploit the huge potential of the dipole emitter orientation in phosphorescent OLEDs.

  11. Analysis of the selected optical parameters of filters protecting against hazardous infrared radiation

    OpenAIRE

    Gralewicz, Grzegorz; Owczarek, Grzegorz

    2016-01-01

    The paper analyses the selected optical parameters of protective optic filters used for protection of the eyes against hazardous radiation within the visible (VIS) and near infrared (NIR) spectrum range. The indexes characterizing transmission and reflection of optic radiation incident on the filter are compared. As it follows from the completed analysis, the newly developed interference filters provide more effective blocking of infrared radiation in comparison with the currently used protec...

  12. Predicting thermal distortion of synchrotron radiation mirrors with finite element analysis

    International Nuclear Information System (INIS)

    DiGennaro, R.; Edwards, W.R.; Hoyer, E.

    1985-10-01

    High power and high power densities due to absorbed radiation are significant design considerations which can limit performance of mirrors receiving highly collimated synchrotron radiation from insertion devices and bending magnet sources. Although the grazing incidence angles needed for x-ray optics spread the thermal load, localized, non-uniform heating can cause distortions which exceed allowable surface figure errors and limit focusing resolution. This paper discusses the suitability of numerical approximations using finite element methods for heat transfer, deformation, and stress analysis of optical elements. The primary analysis objectives are (1) to estimate optical surface figure under maximum heat loads, (2) to correctly predict thermal stresses in order to select suitable materials and mechanical design configurations, and (3) to minimize fabrication costs by specifying appropriate tolerances for surface figure. Important factors which determine accuracy of results include finite element model mesh refinement, accuracy of boundary condition modeling, and reliability of material property data. Some methods to verify accuracy are suggested. Design analysis for an x-ray mirror is presented. Some specific configurations for internal water-cooling are evaluated in order to determine design sensitivity with respect to structural geometry, material properties, fabrication tolerances, absorbed heat magnitude and distribution, and heat transfer approximations. Estimated accuracy of these results is discussed

  13. Evaluation of optical fibres as gamma radiation dosimeter

    International Nuclear Information System (INIS)

    Bohra, Dinesh; Chaudhary, H.S.; Panwar, Lalit; Vaijapurkar, S.G.; Bhatnagar, P.K.; Dasgupta, K.

    2005-01-01

    Semiconductor base gamma and neutron sensors are the fastest and popular dosimeters and are in competition with Thermoluminescence (TL) and Radio photoluminescence (RPL) dosimeters. All over the world armed forces require a dosimeter which records cumulative doses of ionizing radiations from mcGy to 10 Gy and is readable repeatedly without loss of dose information. TL dosimeters do not meet the criteria and RPL dosimeter meet the expectations and are in use by armed forces. Technologists have used laser as an excitation source to stimulate the glass and have achieved success in recording gamma doses of occupational/accidental span (mcGy to 10 Gy). However synthesizing RPL glass batches with exactly same characteristics predoses is a difficult task. Silicon base phosphorous doped step index multimode optical fibre can be made in a significant quantity and large number of dosimeters from it can be achieved with uniform predose. The radiation induced transmission loss gives a measure of gamma dose which is cumulative, readable repeatedly without loss of information. Assorted composition, core dia optical fibres have been synthesized and evaluated for dose linearity, dose rate independence, fading, length optimization. Here in is described some results of recent experiments and sensitivities achieved. (author)

  14. Fibre optics compatibility with radiative environment inside PWR containment

    International Nuclear Information System (INIS)

    Breuze, G.; Jucker, P.; Serre, J.

    1993-01-01

    Fibre optic links operating with multiplexed sensors data are potentially attractive for nuclear power plant applications. It hence became essential to test for radiation vulnerability not only transmission support -fibres- but also fibre-end electro-optical components which could be exposed to hostile environment, perhaps in worse conditions than fibres. Present paper gives results of multimode silica-based fibre behaviour during long-term steady-state low dose-rate gamma ray exposure - one year under 0.1 to 0.2 Gy/h. Studies concerned radiation-induced loss (ΔL) measurement of eight different commercially available fibres and bit error-rate (BER) recording of four 1 100 m length data links operating with a 100 m part exposed to gamma-rays. Main result is the good behaviour of pure silica-core fibres, especially a step-index polymer-clad fibre transmitting 850 nm light but also a graded-index fluorine-clad fibre for 1 300 nm window. Mean ΔL values are respectively 3 dB/km and 4.5 dB/km at the exposure end. Complementary result is no influence of gamma-ray exposure upon data link initial 10 -9 BER. (authors). 9 figs., 7 tabs., 26 refs

  15. Optical Protection Filters for Harmful Laser Beams and UV Radiation

    Science.gov (United States)

    Azim M., Osama A.

    2007-02-01

    Due to the rapid growth of radiation protection applications in various devices and instruments, it is essential to use suitable filters for eye protection of the personal working in the radiation field. Different protection filters were produced to protect from four laser beam wavelengths (at 532nm, 632.8nm, 694nm and 1064nm) and block three UV bands (UVA, UVB, and UVC). The design structure of the required dielectric multilayer filters used optical thin film technology. The computer analyses of the multilayer filter formulas were prepared using Macleod Software for the production filter processes. The deposition technique was achieved on optical substrates (Glass BK-7 and Infrasil 301) by dielectric material combinations including Dralo (mixture of oxides TiO2/Al2O3), and Lima (mixture of oxides SiO2/Al2O3); deposition by an electron beam gun. The output transmittance curves for both theoretical and experimental values of all filters are presented. To validate the suitability for use in a `real world', rather than laboratory test application, full environmental assessment was also carried out. These filters exhibited high endurance after exposing them to the durability tests (adhesion, abrasion resistance and humidity) according to military standards MIL-C-675C and MIL-C-48497A.

  16. Optical Protection Filters for Harmful Laser Beams and UV Radiation

    International Nuclear Information System (INIS)

    Azim M, Osama A.

    2007-01-01

    Due to the rapid growth of radiation protection applications in various devices and instruments, it is essential to use suitable filters for eye protection of the personal working in the radiation field. Different protection filters were produced to protect from four laser beam wavelengths (at 532nm, 632.8nm, 694nm and 1064nm) and block three UV bands (UVA, UVB, and UVC). The design structure of the required dielectric multilayer filters used optical thin film technology. The computer analyses of the multilayer filter formulas were prepared using Macleod Software for the production filter processes. The deposition technique was achieved on optical substrates (Glass BK-7 and Infrasil 301) by dielectric material combinations including Dralo (mixture of oxides TiO2/Al2O3), and Lima (mixture of oxides SiO2/Al2O3); deposition by an electron beam gun. The output transmittance curves for both theoretical and experimental values of all filters are presented. To validate the suitability for use in a 'real world', rather than laboratory test application, full environmental assessment was also carried out. These filters exhibited high endurance after exposing them to the durability tests (adhesion, abrasion resistance and humidity) according to military standards MIL-C-675C and MIL-C-48497A

  17. Assessment of personal exposures to optical radiation in large entertainment venues

    International Nuclear Information System (INIS)

    Bonner, R.; O'Hagan, J. B.; Khazova, M.

    2012-01-01

    Workplace exposure to optical radiation from artificial sources is regulated in Europe under the Artificial Optical Radiation Directive 2006/25/EC implemented in the UK as The Control of Artificial Optical Radiation at Work Regulations 2010. The entertainment environment often presents an extremely complex situation for the assessment of occupational exposures. Multiple illumination sources, continuously changing illumination conditions and people moving during performances add further complexity to the assessment. This document proposes a methodology for assessing the risks arising from exposure to optical radiation and presents detailed case studies of practical assessment for two large entertainment venues. (authors)

  18. Evaluation of material dispersion using a nanosecond optical pulse radiator.

    Science.gov (United States)

    Horiguchi, M; Ohmori, Y; Miya, T

    1979-07-01

    To study the material dispersion effects on graded-index fibers, a method for measuring the material dispersion in optical glass fibers has been developed. Nanosecond pulses in the 0.5-1.7-microm region are generated by a nanosecond optical pulse radiator and grating monochromator. These pulses are injected into a GeO(2)-P(2)0(5)-doped silica graded-index fiber. Relative time delay changes between different wavelengths are used to determine material dispersion, core glass refractive index, material group index, and optimum profile parameter of the graded-index fiber. From the measured data, the optimum profile parameter on the GeO(2)-P(2)O(5)-doped silica graded-index fiber could be estimated to be 1.88 at 1.27 microm of the material dispersion free wavelength region and 1.82 at 1.55 microm of the lowest-loss wavelength region in silica-based optical fiber waveguides.

  19. Earth cloud, aerosol, and radiation explorer optical payload development status

    Science.gov (United States)

    Hélière, A.; Wallace, K.; Pereira do Carmo, J.; Lefebvre, A.

    2017-09-01

    The European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) are co-operating to develop as part of ESA's Living Planet Programme, the third Earth Explorer Core Mission, EarthCARE, with the ojective of improving the understanding of the processes involving clouds, aerosols and radiation in the Earth's atmosphere. EarthCARE payload consists of two active and two passive instruments: an ATmospheric LIDar (ATLID), a Cloud Profiling Radar (CPR), a Multi-Spectral Imager (MSI) and a Broad-Band Radiometer (BBR). The four instruments data are processed individually and in a synergetic manner to produce a large range of products, which include vertical profiles of aerosols, liquid water and ice, observations of cloud distribution and vertical motion within clouds, and will allow the retrieval of profiles of atmospheric radiative heating and cooling. MSI is a compact instrument with a 150 km swath providing 500 m pixel data in seven channels, whose retrieved data will give context to the active instrument measurements, as well as providing cloud and aerosol information. BBR measures reflected solar and emitted thermal radiation from the scene. Operating in the UV range at 355 nm, ATLID provides atmospheric echoes from ground to an altitude of 40 km. Thanks to a high spectral resolution filtering, the lidar is able to separate the relative contribution of aerosol and molecular scattering, which gives access to aerosol optical depth. Co-polarised and cross-polarised components of the Mie scattering contribution are measured on dedicated channels. This paper will provide a description of the optical payload implementation, the design and characterisation of the instruments.

  20. Hybrid formulation of radiation transport in optically thick divertor plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rosato, J.; Marandet, Y.; Bufferand, H.; Stamm, R. [PIIM, UMR 7345 Aix-Marseille Universite / CNRS, Centre de St-Jerome, Marseille (France); Reiter, D. [IEK-4 Plasmaphysik, Forschungszentrum Juelich GmbH, Juelich (Germany)

    2016-08-15

    Kinetic Monte Carlo simulations of coupled atom-radiation transport in optically thick divertor plasmas can be computationally very demanding, in particular in ITER relevant conditions or even larger devices, e.g. for power plant divertor studies. At high (∝ 10{sup 15} cm{sup -3}) atomic densities, it can be shown that sufficiently large divertors behave in certain areas like a black body near the first resonance line of hydrogen (Lyman α). This suggests that, at least in part, the use of continuum model (radiation hydrodynamics) can be sufficiently accurate, while being less time consuming. In this work, we report on the development of a hybrid model devoted to switch automatically between a kinetic and a continuum description according to the plasma conditions. Calculations of the photo-excitation rate in a homogeneous slab are performed as an illustration. The outlined hybrid concept might be also applicable to neutral atom transport, due to mathematical analogy of transport equations for neutrals and radiation. (copyright 2016 The Authors. Contributions to Plasma Physics published by Wiley-VCH Verlag GmbH and Co. KGaA Weinheim. This)

  1. VCSEL-based radiation tolerant optical data links

    CERN Document Server

    Gregor, I M; Dowell, J; Jovanovic, P; Kootz, A; Mahout, G; Mandic, I; Weidberg, T

    2000-01-01

    The Large Hadron Collider (LHC) will become operational in 2005 at The European Laboratory for Particle Physics (CERN). The LHC will be the highest energy proton-proton collider in the world. One of the electronic particle detectors which will operate at the LHC is called ATLAS. The environment for electronics placed within ATLAS is extremely hostile due to the high levels of radiation and the general lack of access to components during the expected 10 year lifetime of the experiment. It is planned to use custom radiation tolerant VCSEL- based optical links to transfer data from the ATLAS inner detector to remote data acquisition electronics. A low mass, non-magnetic and radiation tolerant VCSEL packaging has been developed for the most hostile region in the center of ATLAS where the inner detector is located. The performance of the package is reported on. Qualification tests of commercial VCSELs are also described. The VCSELs were irradiated with neutrons (up to 8.10/sup 14/ n(1 MeV)/cm/sup 2/) and annealing...

  2. Structural modifications of spinels under radiation

    International Nuclear Information System (INIS)

    Quentin, A.

    2010-12-01

    This work is devoted to the study of spinel structure materials under radiation. For that purpose, samples of polycrystalline ZnAl 2 O 4 and monocrystalline MgAl 2 O 4 were irradiated by different heavy ions with different energies. Samples of ZnAl 2 O 4 were studied par electron transmission microscopy, and by grazing incidence X-Ray diffraction and Rietveld analysis. Samples of MgAl 2 O 4 were studied by optical spectroscopy. Most of the results concern amorphization and crystalline structure modification of ZnAl 2 O 4 especially the inversion. We were able to determine a stopping power threshold for amorphization, between 11 keV/nm and 12 keV/nm, and also the amorphization process, which is a multiple impacts process. We studied the evolution of the amorphous phase by TEM and showed a nano-patterning phenomenon. Concerning the inversion, we determined that it did happen by a single impact process, and the saturation value did not reach the random cation distribution value. Inversion and amorphization have different, but close, stopping power threshold. However, amorphization seems to be conditioned by a pre-damage of the material which consists in inversion. (author)

  3. A study on the real-time radiation dosimetry measurement system based on optically stimulated luminescence

    International Nuclear Information System (INIS)

    Liu Yanping; Du Yanzhao; Chen Zhaoyang; Ba Weizhen; Fan Yanwei; Pan Shilie; Guo Qi

    2008-01-01

    The optically stimulated luminescent (OSL) radiation dosimeter technically surveys a wide dynamic measurement range and a high sensitivity. Optical fiber dosimeters provide capability for remote monitoring of the radiation in the locations which are difficult-to-access and hazardous. In addition, optical fiber dosimeters are immune to electrical and radio-frequency interference. In this paper, a novel remote optical fiber radiation dosimeter is described. The optical fiber dosimeter takes advantage of the charge trapping materials CaS:Ce, Sm that exhibit OSL. The measuring range of the dosimeter is from 0.1 to 100 Gy. The equipment is relatively simple and small in size, and has low power consumption. This device is suitable for measuring the space radiation dose and also can be used in high radiation dose condition and other dangerous radiation occasions. (authors)

  4. Thin Film Structure of Tetraceno(2,3-B)thiophene Characterized By Grazing Incidence X-Ray Scattering And Near-Edge X-Ray Absorption Fine Structure Analysis

    International Nuclear Information System (INIS)

    Yuan, Q.; Mannsfeld, S.C.B.; Tang, M.L.; Toney, M.F.; Luening, J.; Bao, Z.A.

    2008-01-01

    Understanding the structure-property relationship for organic semiconductors is crucial in rational molecular design and organic thin film process control. Charge carrier transport in organic field-effect transistors predominantly occurs in a few semiconductor layers close to the interface in contact with the dielectric layer, and the transport properties depend sensitively on the precise molecular packing. Therefore, a better understanding of the impact of molecular packing and thin film morphology in the first few monolayers above the dielectric layer on charge transport is needed to improve the transistor performance. In this Article, we show that the detailed molecular packing in thin organic semiconductor films can be solved through a combination of grazing incidence X-ray diffraction (GIXD), near-edge X-ray absorption spectra fine structure (NEXAFS) spectroscopy, energy minimization packing calculations, and structure refinement of the diffraction data. We solve the thin film structure for 2 and 20 nm thick films of tetraceno(2,3-b)thiophene and detect only a single phase for these thicknesses. The GIXD yields accurate unit cell dimensions, while the precise molecular arrangement in the unit cell was found from the energy minimization and structure refinement; the NEXAFS yields a consistent molecular tilt. For the 20 nm film, the unit cell is triclinic with a = 5.96 A, b = 7.71 A, c = 15.16 A, alpha = 97.30 degrees, beta = 95.63 degrees, gamma = 90 degrees; there are two molecules per unit cell with herringbone packing (49-59 degree angle) and tilted about 7 degrees from the substrate normal. The thin film structure is significantly different from the bulk single-crystal structure, indicating the importance of characterizing thin film to correlate with thin film device performance. The results are compared to the corresponding data for the chemically similar and widely used pentacene. Possible effects of the observed thin film structure and morphology on

  5. Grazing incidence collisions of ions and atoms with surfaces: from charge exchange to atomic diffraction; Collisions rasantes d'ions ou d'atomes sur les surfaces: de l'echange de charge a la diffraction atomique

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, P

    2006-09-15

    This thesis reports two studies about the interaction with insulating surfaces of keV ions or atoms under grazing incidence. The first part presents a study of charge exchange processes occurring during the interaction of singly charged ions with the surface of NaCl. In particular, by measuring the scattered charge fraction and the energy loss in coincidence with electron emission, the neutralization mechanism is determined for S{sup +}, C{sup +}, Xe{sup +}, H{sup +}, O{sup +}, Kr{sup +}, N{sup +}, Ar{sup +}, F{sup +}, Ne{sup +} and He{sup +}. These results show the importance of the double electron capture as neutralization process for ions having too much potential energy for resonant capture and not enough for Auger neutralization. We have also studied the ionisation of the projectile and of the surface, and the different Auger-like neutralization processes resulting in electron emission, population of conduction band or excited state. For oxygen scattering, we have measured an higher electron yield in coincidence with scattered negative ion than with scattered atom suggesting the transient formation above the surface of the oxygen doubly negative ion. The second study deals with the fast atom diffraction, a new phenomenon observed for the first time during this work. Due to the large parallel velocity, the surface appears as a corrugated wall where rows interfere. Similarly to the Thermal Atom Scattering the diffraction pattern corresponds to the surface potential and is sensitive to vibrations. We have study the H-NaCl and He-LiF atom-surface potentials in the 20 meV - 1 eV range. This new method offers interesting perspectives for surface characterisation. (author)

  6. Direct quantification of TiO{sub 2} nanoparticles in suspension by grazing-incidence X-ray fluorescence spectrometry: Influence of substrate pre-treatment in the deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Motellier, S., E-mail: Sylvie.motellier@cea.fr [Commissariat à l' Energie Atomique et aux Energies alternatives, DRT/LITEN/DTNM/LCSN, 17 rue des martyrs, F-38054 GRENOBLE CEDEX (France); Derrough, S.; Locatelli, D. [Commissariat à l’Energie Atomique et aux Energies alternatives, DRT/NanoSafety Plateform, 17 rue des martyrs, F-38054 GRENOBLE CEDEX (France); Amdaoud, M.; Lhaute, K. [Commissariat à l' Energie Atomique et aux Energies alternatives, DRT/LITEN/DTNM/LCSN, 17 rue des martyrs, F-38054 GRENOBLE CEDEX (France)

    2013-10-01

    X-ray fluorescence at grazing incidence (GIXRF) was investigated as a method for the quantification of TiO{sub 2} nanoparticles in aqueous suspensions. One of the major advantages of this technique is the possibility to analyze the particles without pre-treatment, like harsh acid digestion, as required by most other conventional methods. However, reliable quantitative measurements require a number of precautions. Particularly, the deposition process of the sample on the flat reflecting substrate must maintain homogeneity in composition and concentration over the entire surface of the deposition residue once dried. Scanning electron microscopy showed that using an adhesive coating of the substrate significantly improves the morphology and chemical homogeneity of the residue, hence leading to better performance of the method from a quantitative point of view. Linear calibration curves using internal standardization were established with ionic Ti and with two different types of TiO{sub 2} nanoparticles. Low limits of detections of 18 μg L{sup −1} and 52 μg L{sup −1} at incident angles of 0.20° and 0.75°, respectively, were obtained. It was found that correlation factors of the calibration linear fits were particle-size dependent, which was assigned to sampling problems due to possible incomplete dispersion of the particles in suspensions. The measured fluorescence of the dried deposits changed within a 4-month timespan for both types of TiO{sub 2} nanoparticles, demonstrating the very peculiar behavior of these particulate samples. - Highlights: • Suspensions of TiO{sub 2} nanoparticles were quantitatively analyzed by GIXRF. • The substrate was coated with an adhesive film prior to sample deposition. • Improved spatial homogeneity of the dry spot residue was confirmed by SEM/EDX. • Linear calibration curves were obtained with ionic Cr as internal standard. • Ti low limits of detections were in the 20–50 μg L{sup −1}.

  7. Proposal for the development of ICNIRP guidelines on limits for optical radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Siekmann, H. [Berufsgenossenschaftliches Institut fuer Arbeitsschutz - FIA, Sankt Augustin (Germany); Reidenbach, H.D. [Fachhochschule Koeln (Germany)

    2004-07-01

    Guidelines on limits of exposure to incoherent ultraviolet radiation, to incoherent visible and infrared radiation and to laser radiation have been published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are accepted globally and form the basis for risk assessment procedures for optical radiation in many countries. With the appearance of new scientific cognition the ICNIRP guidelines will be revised from time to time. A revision may also concern more formal aspects. Some proposals for the development of the ICNIRP limit value recommendations for optical radiation exposures follow. (orig.)

  8. Optical Cherenkov radiation in ultrafast cascaded second-harmonic generation

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Zhou, Binbin

    2010-01-01

    -matching point is located in the absorption region of the crystal, effectively absorbing the generated dispersive wave. By calculating the phase-matching curves for typically used frequency conversion crystals, we point out that the mid-IR absorption in the crystal in many cases automatically will filter away....... The beating between the dispersive wave and the soliton generates trailing temporal oscillations on the compressed soliton. Insertion of a simple short-wave pass filter after the crystal can restore a clean soliton. On the other hand, bandpass filtering around the dispersive wave peak results in near......We show through theory and numerics that when few-cycle femtosecond solitons are generated through cascaded (phase-mismatched) second-harmonic generation, these broadband solitons can emit optical Cherenkov radiation in the form of linear dispersive waves located in the red part of the spectrum...

  9. Optical transition radiation interferometry for the A0 photoinjector

    International Nuclear Information System (INIS)

    Kazakevich, G.; Novosibirsk, IYF; Edwards, H.; Fliller, R.; Nagaitsev, S.; Ruan, J.; Thurman-Keup, R.; Fermilab

    2008-01-01

    Optical Transition Radiation Interferometry (OTRI) is a promising diagnostic technique and has been successfully developed and used for investigation of relativistic beams. For mid-energy accelerators the technique is traditionally based on thin polymer films (the first one is being transparent for visible light), which causes beam multiple scattering of about 1 mrad. A disadvantage of those films is unacceptable vacuum properties for photoinjectors and accelerators using superconducting cavities. We have studied the application of thin mica sheets for the OTRI diagnostics at the A0 Photoinjector in comparison with 2.5 (micro)m thick Mylar films. This diagnostic is also applicable for the ILCTA-NML accelerator test facility that is planned at Fermilab. This report discusses the experimental setups of the OTR interferometer for the A0 Photoinjector and presents comparisons of simulations and measurements obtained using Mylar and mica-based interferometers

  10. A general purpose fiber optic link with radiation resistance

    International Nuclear Information System (INIS)

    Beadle, E.R.

    1995-01-01

    In some applications it is necessary to send wide-band analog data, with good fidelity, between two stations separated by several hundred feet. This is particularly true for instrumentation in an accelerator environment, where the sensing equipment can be inside the tunnel, and the processing equipment outside. Aside from the distortion and loss introduced by low cost coaxial cables, this case is further complicated by the possibility of pick-up from environmental noise, and the possible radiation damage of the transmitting electronics. Fiber optics is be a viable alternative to the standard coaxial driver, particularly where video bandwidths are concerned. This paper discusses basic design, trade-offs, and performance of one such link developed primarily for the AGS-to-RHIC (ATR) Transfer line profile monitors

  11. Film thickness determination by grazing incidence diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Battiston, G A; Gerbasi, R [CNR, Padua (Italy). Istituto di Chimica e Tecnologie Inorganiche e dei Materiali Avanzati

    1996-09-01

    Thin films deposited via MOCVD (Metal Organic Chemical Vapour Deposition) are layers in the thickness range of a few manometers to about ten micrometers. An understanding of the physics and chemistry of films is necessary for a better comprehension of the phenomena involved in the film deposition procedure and its optimisation. Together with the crystalline phase a parameter that must be determined is the thickness of the layer. In this work the authors present a method for the measurement of the film thickness. This procedure, based on diffraction intensity absorption of the X-rays, both incident and diffracted in passing through the layers, resulted quite simple, rapid and non-destructive.

  12. Film thickness determination by grazing incidence diffraction

    International Nuclear Information System (INIS)

    Battiston, G. A.; Gerbasi, R.

    1996-01-01

    Thin films deposited via MOCVD (Metal Organic Chemical Vapour Deposition) are layers in the thickness range of a few manometers to about ten micrometers. An understanding of the physics and chemistry of films is necessary for a better comprehension of the phenomena involved in the film deposition procedure and its optimisation. Together with the crystalline phase a parameter that must be determined is the thickness of the layer. In this work the authors present a method for the measurement of the film thickness. This procedure, based on diffraction intensity absorption of the X-rays, both incident and diffracted in passing through the layers, resulted quite simple, rapid and non-destructive

  13. On the formation of TW Crv optical radiation

    Science.gov (United States)

    Shimansky, V. V.; Mitrofanova, A. A.; Borisov, N. V.; Fabrika, S. N.; Galeev, A. I.

    2016-10-01

    We present the analysis of the optical radiation of the young pre-cataclysmic variable TW Crv. Spectroscopic and photometric observations were obtained at the SAO RAS 6-m BTA telescope and at the Russian-Turkish RTT-150 telescope. The light curves of the system posses nearly sinusoidal shapes with the amplitudes of Δ m > 0.m7, what is typical for young pre-cataclysmic variables with sdO-subdwarfs and orbit inclinations of less than 45◦. The optical spectrum contains dominant radiation of the hot subdwarf with the HI and He II absorption lines and strong emission lines, which are formed in the atmosphere of the secondary owing to the reflection effects. Radial velocities of the cool star were measured by analyzing the λλ 4630-4650 Å Bowen blend, which for the first time allowed to determine the component masses. A numerical simulation of the light curves and spectra of TW Crv, obtaining a complete set of systems fundamental parameters was carried out. The hot star parameters prompt its belonging to the sdOsubdwarf class at the stage of transition to the cooling white dwarf sequence. The absence of its observable planetary nebula is caused by a long-lasting evolution of the system after the common envelope state. The secondary component has a luminosity excess, which is typical for other young sdO-subdwarf precataclysmic variables. Its position on the " age-luminosity excess" diagram points at the accuracy of the obtained set of TW Crv fundamental parameters and at the similarity of its evolutionary and physical conditions with that of other BE UMa-type objects.

  14. Optics

    CERN Document Server

    Mathieu, Jean Paul

    1975-01-01

    Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

  15. Radiation-optical properties of the glasses for the space application

    International Nuclear Information System (INIS)

    Akishin, A.I.; Tseplyaev, L.I.

    2006-01-01

    The data are presented and generalized on variations of optical properties of glass and light guides under simulative cosmic ionizing radiation. It is shown that changes in optical properties (coloration, bleaching, opacity, luminescence) under ionizing radiation are associated with color centers formation and annealing [ru

  16. Multi Optical Transition Radiation System for ATF2

    International Nuclear Information System (INIS)

    Alabau-Gonzalvo, Javier

    2012-01-01

    In this paper we describe the design, installation and first calibration tests of a Multi Optical Transition Radiation System in the beam diagnostic section of the Extraction (EXT) line of ATF2, close to the multi wire scanner system. This system will be a valuable tool for measuring beam sizes and emittances coming from the ATF Damping Ring. With an optical resolution of about 2 (micro)m an original OTR design (OTR1X) located after the septum at the entrance of the EXT line demonstrated the ability to measure a 5.5 (micro)m beam size in one beam pulse and to take many fast measurements. This gives the OTR the ability to measure the beam emittance with high statistics, giving a low error and a good understanding of emittance jitter. Furthermore the nearby wire scanners will be a definitive test of the OTR as a beam emittance diagnostic device. The multi-OTR system design proposed here is based on the existing OTR1X.

  17. Optical response of thin amorphous films to infrared radiation

    Science.gov (United States)

    Orosco, J.; Coimbra, C. F. M.

    2018-03-01

    We briefly review the electrical-optical response of materials to radiative forcing within the formalism of the Kramers-Kronig relations. A commensurate set of criteria is described that must be met by any frequency-domain model representing the time-domain response of a real (i.e., physically possible) material. The criteria are applied to the Brendel-Bormann (BB) oscillator, a model that was originally introduced for its fidelity at reproducing the non-Lorentzian peak broadening experimentally observed in the infrared absorption by thin amorphous films but has since been used for many other common materials. We show that the BB model fails to satisfy the established physical criteria. Taking an alternative approach to the model derivation, a physically consistent model is proposed. This model provides the appropriate line-shape broadening for modeling the infrared optical response of thin amorphous films while adhering strictly to the Kramers-Kronig criteria. Experimental data for amorphous alumina (Al2O3 ) and amorphous quartz silica (SiO2) are used to obtain model parametrizations for both the noncausal BB model and the proposed causal model. The proposed model satisfies consistency criteria required by the underlying physics and reproduces the experimental data with better fidelity (and often with fewer parameters) than previously proposed permittivity models.

  18. Optical breakdown of helium in Bessel laser radiation beams

    International Nuclear Information System (INIS)

    Andreev, N E; Pleshanov, I V; Margolin, L Ya; Pyatnitskii, Lev N

    1998-01-01

    Numerical simulation is used to investigate the dynamics of formation of a helium plasma in Bessel beams, shaped by an axicon and a phase converter from a laser radiation pulse with Gaussian temporal and radial intensity profiles. The beam intensities at the breakdown threshold are determined as a function of the pulse duration for various radial field distributions in a beam characterised by Bessel functions of order m (m = 0 - 5). It is shown that in the investigated range of parameters the threshold intensity is independent of m. The temporal and spatial evolution of the resultant plasma, and the dependence of the plasma characteristics on the pulse parameters are considered. Conditions are found for the formation of tubular plasma channels in beams of orders m≥1. The adopted model of the optical breakdown of helium is shown to be satisfactory because of a good agreement between the results of calculations of the moment of breakdown in a zeroth-order Bessel beam and experimental results. (interaction of laser radiation with matter. laser plasma)

  19. Acoustical and optical radiation pressure and the development of single beam acoustical tweezers

    Science.gov (United States)

    Thomas, Jean-Louis; Marchiano, Régis; Baresch, Diego

    2017-07-01

    Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and position micron size particles, biological samples or even atoms with subnanometer accuracy in three dimensions. One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. Acoustical tweezers overcome this limitation since the radiation pressure scales as the field intensity divided by the speed of propagation of the wave. However, the feasibility of single beam acoustical tweezers was demonstrated only recently. In this paper, we propose a historical review of the strong similarities but also the specificities of acoustical and optical radiation pressures, from the expression of the force to the development of single-beam acoustical tweezers.

  20. ALL-OPTICAL CONTROL OF THZ RADIATION IN PARALLEL PLATE WAVEGUIDES

    DEFF Research Database (Denmark)

    2010-01-01

    The invention relates to control of THz radiation in parallel plate waveguides (PPWG) by forming components in the waveguide by use of optical radiation pulses. Patterns of excited regions induced in the PPWG by an optical excitation pulses changes the electromagnetic properties of the waveguide...... medium in the THz regime, thereby forming transient passive and active components for controlling THz radiation signals. The excitation can be generation of free charge carriers in a semiconductor material in the PPWG, to create metallic regions that form mirrors, lenses or photonic crystal structures......-on-a-chip applications. The optical and THz radiation can be ultrashort pulses with picosecond or femtosecond pulse durations. L...

  1. The transition radiation. 2. experimental study of the optical transition radiation

    International Nuclear Information System (INIS)

    Couillaud, Ch.; Haouat, G.; Seguin, S.; Striby, S.

    1999-01-01

    Optical-transition-radiation-based diagnostics have been widely used for many years on electron accelerators in order to measure beam energy and transverse and longitudinal emittances. These diagnostics are very attractive for high brightness electron beams used as drivers for radiation sources. Such diagnostics have been performed on the ELSA facility (18 MeV electron energy, 100 A peak current) using both a single interface and an OTR-Wartski interferometer. We present the accelerator, the experimental set-up and the method for analyzing the OTR angular distribution. Then, the experimental results are described and compared with those from the three gradient method. In addition, we present a beam energy measurement using OTR interferogram analysis. (author)

  2. Aerosol optical properties and direct radiative forcing at Taihu.

    Science.gov (United States)

    Lü, Rui; Yu, Xingna; Jia, Hailing; Xiao, Sihan

    2017-09-01

    Ground-based characteristics (optical, type, size, and radiative properties) of aerosols measured between 2005 and 2012 were investigated over the Taihu rim region, which encompasses the cities of Shanghai, Suzhou, Wuxi, and Changzhou. The aerosol optical depth (AOD) showed a distinct seasonal variation with the highest value in summer and the lowest AOD in winter. There was broadest frequency distribution with a multimodal structure in summer. The Ångström exponent (AE) showed high values during spring; the relative frequency of AE in the range of 0-0.8 was 5-10 times greater than that of other seasons. The samples with high AOD 440 and low AE 440-870 were mainly observed in spring, which is attributed to the relative abundance of coarse particles. The monthly aerosol volume size distributions presented a bimodal structure (fine and coarse modes). The coarse mode was dominant during spring, while the fine mode was predominant in other seasons. The main aerosol type over Taihu during all the seasons was the mixed small-particle category, followed by the urban/industrial category. The minimum single scattering albedo (SSA) occurred in winter, suggesting that atmosphere aerosol had a higher absorption. All monthly averaged asymmetry factors (ASY) had positive values and no distinct seasonal variation. Both high real (Re) and imaginary (Im) parts of the refractive index occurred in winter. The atmospheric warming effect of aerosol was more significant in winter compared with other seasons, with the averaged atmosphere aerosol radiative forcing (ARF) and the corresponding atmospheric heating rate up to +69.46  W·m -2 and 1.95  K·day -1 , respectively. There existed a significant positive correlation between AOD and ARF (absolute value), and the correlation coefficients (r) exceeded 0.86 in each season with maximum r in summer. Along with the increasing of the SSA, the aerosol radiative forcing efficiency (absolute value) showed a decreasing trend at the

  3. Acoustical and optical radiation pressures and the development of single beam acoustical tweezers

    OpenAIRE

    Thomas , Jean-Louis; Marchiano , Régis; Baresch , Diego

    2017-01-01

    International audience; Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and positioned micron size particles, biological samples or even atoms with subnanometer accuracy in three dimens...

  4. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation at Thessaloniki, Greece

    Directory of Open Access Journals (Sweden)

    A. V. Lindfors

    2013-04-01

    Full Text Available Pyranometer measurements of the solar surface radiation (SSR are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, was developed and tested using recent data from Thessaloniki, Greece. The effective AOD calculated using this method was found to agree well with co-located AERONET measurements, exhibiting a correlation coefficient of 0.9 with 2/3 of the data found within ±20% or ±0.05 of the AERONET AOD. This is similar to the performance of current satellite aerosol methods. Differences in the AOD as compared to AERONET can be explained by variations in the aerosol properties of the atmosphere that are not accounted for in the idealized settings used in the radiative transfer simulations, such as variations in the single scattering albedo and Ångström exponent. Furthermore, the method is sensitive to calibration offsets between the radiative transfer simulations and the pyranometer SSR. The method provides an opportunity of extending our knowledge of the atmospheric aerosol load to locations and times not covered by dedicated aerosol measurements.

  5. A novel DC Magnetron sputtering facility for space research and synchrotron radiation optics

    DEFF Research Database (Denmark)

    Hussain, A.M.; Christensen, Finn Erland; Pareschi, G.

    1998-01-01

    A new DC magnetron sputtering facility has been build up at the Danish Space Research Institute (DSRI), specially designed to enable uniform coatings of large area curved optics, such as Wolter-I mirror optics used in space telescopes and curved optics used in synchrotron radiation facilities...

  6. X-Ray Optics at NASA Marshall Space Flight Center

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Broadway, David M.; Elsner, Ronald F.; Gaskin, Jessica A.; Gubarev, Mikhail V.; Kilaru, Kiranmayee; Kolodziejczak, Jeffery J.; Ramsey, Brian D.; Roche, Jacqueline M.; hide

    2015-01-01

    NASA's Marshall Space Flight Center (MSFC) engages in research, development, design, fabrication, coating, assembly, and testing of grazing-incidence optics (primarily) for x-ray telescope systems. Over the past two decades, MSFC has refined processes for electroformed-nickel replication of grazing-incidence optics, in order to produce high-strength, thin-walled, full-cylinder x-ray mirrors. In recent years, MSFC has used this technology to fabricate numerous x-ray mirror assemblies for several flight (balloon, rocket, and satellite) programs. Additionally, MSFC has demonstrated the suitability of this technology for ground-based laboratory applications-namely, x-ray microscopes and cold-neutron microscopes and concentrators. This mature technology enables the production, at moderately low cost, of reasonably lightweight x-ray telescopes with good (15-30 arcsecond) angular resolution. However, achieving arcsecond imaging for a lightweight x-ray telescope likely requires development of other technologies. Accordingly, MSFC is conducting a multi-faceted research program toward enabling cost-effective production of lightweight high-resolution x-ray mirror assemblies. Relevant research topics currently under investigation include differential deposition for post-fabrication figure correction, in-situ monitoring and control of coating stress, and direct fabrication of thin-walled full-cylinder grazing-incidence mirrors.

  7. Optical imaging of oral pathological tissue using optical coherence tomography and synchrotron radiation computed microtomography

    Science.gov (United States)

    Cânjǎu, Silvana; Todea, Carmen; Sinescu, Cosmin; Negrutiu, Meda L.; Duma, Virgil; Mǎnescu, Adrian; Topalǎ, Florin I.; Podoleanu, Adrian Gh.

    2013-06-01

    The efforts aimed at early diagnosis of oral cancer should be prioritized towards developing a new screening instrument, based on optical coherence tomography (OCT), to be used directly intraorally, able to perform a fast, real time, 3D and non-invasive diagnosis of oral malignancies. The first step in this direction would be to optimize the OCT image interpretation of oral tissues. Therefore we propose plastination as a tissue preparation method that better preserves three-dimensional structure for study by new optical imaging techniques. The OCT and the synchrotron radiation computed microtomography (micro-CT) were employed for tissue sample analyze. For validating the OCT results we used the gold standard diagnostic procedure for any suspicious lesion - histopathology. This is a preliminary study of comparing features provided by OCT and Micro-CT. In the conditions of the present study, OCT proves to be a highly promising imaging modality. The use of x-ray based topographic imaging of small biological samples has been limited by the low intrinsic x-ray absorption of non-mineralized tissue and the lack of established contrast agents. Plastination can be used to enhance optical imagies of oral soft tissue samples.

  8. Large arrays of discrete ionizing radiation detectors multiplexed using fluorescent optical converters

    International Nuclear Information System (INIS)

    Koslow, E.E.; Edelman, R.R.

    1985-01-01

    This invention provides a radiation imaging system employing arrays of scintillators. An object of the invention is to produce a detector with high spatial resolution, high gamma-photon absorption efficiency, excellent source and detector scatter rejection, and utilizing low-cost solid state opto-electronic devices. In one embodiment, it provides a radiation detection and conversion apparatus having an array of optically isolated radiation sensitive elements that emit optical radiation upon absorption of ionizing radiation. An array of channels, comprising a material that absorbs and traps the radiation emitted and transports it or radiation that has been shifted to longer wavelengths, is placed near the radiation-sensitive elements. Electro-optical detectors that convert the transported radiation into electrical signals are coupled to the channels. The activation of one of the electro-optical devices by radiation from one of the channels indicates that at least one of the radiation-sensitive elements near that channel has absorbed a quantity of radiation

  9. Acoustical and optical radiation pressure and the development of single beam acoustical tweezers

    International Nuclear Information System (INIS)

    Thomas, Jean-Louis; Marchiano, Régis; Baresch, Diego

    2017-01-01

    Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and position micron size particles, biological samples or even atoms with subnanometer accuracy in three dimensions. One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. Acoustical tweezers overcome this limitation since the radiation pressure scales as the field intensity divided by the speed of propagation of the wave. However, the feasibility of single beam acoustical tweezers was demonstrated only recently. In this paper, we propose a historical review of the strong similarities but also the specificities of acoustical and optical radiation pressures, from the expression of the force to the development of single-beam acoustical tweezers. - Highlights: • Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. • Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. • However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. • Optical tweezers can trap, move and positioned micron size particles with subnanometer accuracy in three dimensions. • One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. • Acoustical tweezers overcome this limitation since the force scales as the field intensity divided by its propagation speed. • However, the feasibility of single beam acoustical tweezers was demonstrated only recently. • We propose a review of the strong similarities but also the specificities of acoustical

  10. Astronomical optics and elasticity theory

    CERN Document Server

    Lemaitre, Gerard Rene

    2008-01-01

    Astronomical Optics and Elasticity Theory provides a very thorough and comprehensive account of what is known in this field. After an extensive introduction to optics and elasticity, the book discusses variable curvature and multimode deformable mirrors, as well as, in depth, active optics, its theory and applications. Further, optical design utilizing the Schmidt concept and various types of Schmidt correctors, as well as the elasticity theory of thin plates and shells are elaborated upon. Several active optics methods are developed for obtaining aberration corrected diffraction gratings. Further, a weakly conical shell theory of elasticity is elaborated for the aspherization of grazing incidence telescope mirrors. The very didactic and fairly easy-to-read presentation of the topic will enable PhD students and young researchers to actively participate in challenging astronomical optics and instrumentation projects.

  11. Kirkpatrick-Baez (KB) and Lobster Eye (LE) Optics for Astronomical and Laboratory Applications

    International Nuclear Information System (INIS)

    Hudec, R.; Hudec, R.

    2010-01-01

    Most of grazing incidence (reflective) X-ray imaging systems used in astronomy and in other (laboratory) applications are based on the Wolter 1 (or modified) arrangement. But there were proposed also other designs and configurations, which are considered for future applications for both in laboratory and (finitely) in space. The Kirkpatrick-Baez (KB) lenses as well as various types of Lobster-Eye (LE) optics and MCP/Micropore optics serve as an example. Analogously to Wolter lenses, the X-rays are mostly reflected twice in these systems to create focal images. The KB systems have already found wide usage in laboratory and synchrotron, both application are reviewed and discussed in detail in this paper. While this paper focuses on future possible applications of non-Wolter grazing incidence systems in space and astronomy, we also discuss in detail applications in other areas of science, where (in contrary to astronomy) some of these systems have demonstrated their advantages

  12. Radiation-resistance test on optical fiber for artificial satellite

    International Nuclear Information System (INIS)

    Morita, Yosuke; Seguchi, Tadao; Mori, Tatsuo; Miyaji, Yuji.

    1985-01-01

    Radiation resistance of a prototype optical fiber for use in artificial satellites is investigated under a long-term irradiation of gamma rays at relatively low dose rates. The optical fiber tested is composed of a pure silica core and an F-doped cladding. Various aspects of the relations between induced loss and irradiation time are observed and results obtained are discussed. It is generally accepted that a satellite and its equipment should be resistant to a total dose of about 1 x 10 6 rad. In the present test, accordingly, gamma ray irradiation is performed up to a total dose of 1 x 10 6 rad at a dose rate of 1 x 10 4 rad/h (for 100 h), 3 x 10 3 rad/h (333 h) and 1 x 10 3 rad/h (1000 h), and it is shown that the loss induced in this fiber at these dose rates is 23.6 - 27.2, 16.9 - 21.6 and 12.5 - 13.5 dB/km, respectively. On the other hand, it has been reported that the loss induced at the dose rate of 1 x 10 6 rad/h (1 h) is about 600 dB/km, which is much larger than the above values. From these results, the loss at a dose rate of 100 rad/h, which would be expected in a satellite, is estimated at about 10 dB/km. It is concluded that this prototype fiber has a sufficient capability for satellite use with respect to induced loss. (Nogami, K.)

  13. Radiation Dosimetry Using Three-Dimensional Optical Random Access Memories

    International Nuclear Information System (INIS)

    Moscovitch, M.

    2001-01-01

    The ability to determine particle type and energy plays an important role in the dosimetry of heavy charged particles (HCP) and neutrons. A new approach to radiation dosimetry is presented, which is shown to be capable of particle type and energy discrimination. This method is based on utilizing radiation induced changes in the digital information stored on three-dimensional optical random access memories (3D ORAM). 3D ORAM is a small cube (a few mm 3 ) composed of poly(methyl methacrylate) doped with a photochromic dye, and it was originally proposed as a memory device in high speed parallel computers. A Nd:YAG laser system is used to write and read binary information (bits) on the ORAM, which functions as a charged particle detector. Both the read and the write processes use two laser beams that simultaneously strike the material to cause a color change at their intersection (similar to the darkening of light-sensitive sunglasses when exposed to sunlight.) The laser produces color changes in the ORAM, which then reverts to the original color (''bit-flips'') at sites where energy is deposited from interaction with incident HCP or neutron-recoil protons. The feasibility of this approach was demonstrated both theoretically and experimentally. Calculations based on track structure theory (TST) predict that when HCP interact with the ORAM material, the local energy deposition is capable of inducing measurable ''bit-flips''. These predictions were recently confirmed experimentally using two types of ORAM systems, one based on spirobenzopyran and the other on anthracene, as the photochromic dyes

  14. Radiation dosimetry using three-dimensional optical random access memories

    International Nuclear Information System (INIS)

    Moscovitch, M.; Phillips, G.W.; Cullum, B.M.; Mobley, J.; Bogard, J.S.; Emfietzoglou, D.; Vo-Dinh, T.

    2002-01-01

    The ability to determine particle type and energy plays an important role in the dosimetry of heavy charged particles (HCP) and neutrons. A new approach to radiation dosimetry is presented, which is shown to be capable of particle type and energy discrimination. This method is based on utilising radiation induced changes in the digital information stored on three-dimensional optical random access memories (3D ORAM). 3D ORAM is a small cube (a few mm 3 ) composed of poly(methyl methacrylate) doped with a photochromic dye, and it was originally proposed as a memory device in high speed parallel computers. A Nd:YAG laser system is used to write and read binary information (bits) on the ORAM, which functions as a charged particle detector. Both the read and the write processes use two laser beams that simultaneously strike the material to cause a colour change at their intersection (similar to the darkening of light-sensitive sunglasses when exposed to sunlight). The laser produces colour changes in the ORAM, which then reverts to the original colour ('bit-flips') at sites where energy is deposited from interaction with incident HCP or neutron-recoil protons. The feasibility of this approach was demonstrated both theoretically and experimentally. Calculations based on track structure theory predict that when HCP interact with the ORAM material, the local energy deposition is capable of inducing measurable 'bit-flips'. These predictions were recently confirmed experimentally using two types of ORAM systems, one based on spirobenzopyran and the other on anthracene, as the photochromic dyes. (author)

  15. Radiation effects on radiation-hardened KU and KS-4V optical fibres

    International Nuclear Information System (INIS)

    Ivanov, A.A.; Tugarinov, S.N.; Kaschuck, Y.A.; Krasilnikov, A.V.; Bender, S.E.

    1999-01-01

    The aim of this work was to test the un-pretreated and the hardened (H 2 -loaded and pre-irradiated) KS-4V and KU optical fibres in reactor environment by in-situ measurements of both the radiation-induced loss and the luminescence in the visible spectral region. Both the radio-luminescent and the transmission spectra were in-situ detected during irradiation by charge-coupled-device (CCD) linear detector in the visible spectral region of 400 to 700 nm. The radiation induced loss spectra at the fast neutron fluence of 2*10 6 n/cm 2 shows the hardened, H 2 -loading and pre-irradiating effects in the both KU and KS-4V fibres. KU un-pretreated fibre shows a big radiation absorption band of non-bridging oxygen centered at the wavelength of 630 nm. It appears that the KS-4V hardened fibre has a specific point in the loss spectrum in the vicinity of 460 nm. Other measurements were performed, particularly after reactor shutdown and at 3 different neutron fluences with constant neutron flux after restarting

  16. Radiation-hard/high-speed parallel optical links

    International Nuclear Information System (INIS)

    Gan, K.K.; Buchholz, P.; Kagan, H.P.; Kass, R.D.; Moore, J.; Smith, D.S.; Wiese, A.; Ziolkowski, M.

    2014-01-01

    We have designed an ASIC for use in a parallel optical engine for a new layer of the ATLAS pixel detector in the initial phase of the LHC luminosity upgrade. The ASIC is a 12-channel VCSEL (Vertical Cavity Surface Emitting Laser) array driver capable of operating up to 5 Gb/s per channel. The ASIC is designed using a 130 nm CMOS process to enhance the radiation-hardness. A scheme for redundancy has also been implemented to allow bypassing of a broken VCSEL. The ASIC also contains a power-on reset circuit that sets the ASIC to a default configuration with no signal steering. In addition, the bias and modulation currents of the individual channels are programmable. The performance of the first prototype ASIC up to 5 Gb/s is satisfactory. Furthermore, we are able to program the bias and modulation currents and to bypass a broken VCSEL channel. We are currently upgrading our design to allow operation at 10 Gb/s per channel yielding an aggregated bandwidth of 120 Gb/s. Some preliminary results of the design will be presented

  17. LCLS-S1 optical transition radiation monitor

    International Nuclear Information System (INIS)

    Berg, W.J.; Yang, B.; Erwin, L.L.; Shoaf, S.E.

    2008-01-01

    Argonne National Laboratory has developed a high- resolution optical transition radiation (OTR) imaging monitor for the Linac Coherent Light Source (LCLS) injection linac at SLAC. The imaging station,OTR-S1, will be located at the S1 spectrometer with a beam energy of 135 MeV. The system will be used to acquire 2-D transverse beam distributions of the accelerated photocathode-gun-generated electron beam. We anticipate an average beam current of 0.2 to 1 nC and nominal beam spot size of 130 mum (sigmax), 100 mum (sigmay). The imaging system was designed for a field of view x/y: 10 times 7.5 mm. The spatial resolution of ∼12 microns was verified over the central 5times4 mm region in the visible. A 12-bit digital camera acquires the image and a Mac-based digital frame-capturing system was employed for the initial lab-based performance testing of the device. We report on system development, testing methods, and data analysis.

  18. Ionizing Radiation Detectors Based on Ge-Doped Optical Fibers Inserted in Resonant Cavities

    Directory of Open Access Journals (Sweden)

    Saverio Avino

    2015-02-01

    Full Text Available The measurement of ionizing radiation (IR is a crucial issue in different areas of interest, from environmental safety and industrial monitoring to aerospace and medicine. Optical fiber sensors have recently proven good candidates as radiation dosimeters. Here we investigate the effect of IR on germanosilicate optical fibers. A piece of Ge-doped fiber enclosed between two fiber Bragg gratings (FBGs is irradiated with gamma radiation generated by a 6 MV medical linear accelerator. With respect to other FBG-based IR dosimeters, here the sensor is only the bare fiber without any special internal structure. A near infrared laser is frequency locked to the cavity modes for high resolution measurement of radiation induced effects on the fiber optical parameters. In particular, we observe a variation of the fiber thermo-optic response with the radiation dose delivered, as expected from the interaction with Ge defect centers, and demonstrate a detection limit of 360 mGy. This method can have an impact in those contexts where low radiation doses have to be measured both in small volumes or over large areas, such as radiation therapy and radiation protection, while bare optical fibers are cheap and disposable.

  19. Radiation Hard Multi-Layer Optical Coatings, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Next generation space telescopes require advanced optical coatings to provide low loss transmission of light in a variety of spectral ranges and protect optical...

  20. All-optical switching of the transmission of electromagnetic radiation through subwavelength apertures

    NARCIS (Netherlands)

    Janke, C.; Gómez Rivas, J.; Haring Bolivar, P.; Kurz, H.

    2005-01-01

    Unprecedented optical control of the surface plasmon polariton assisted transmission of terahertz radiation through subwavelength apertures is rendered possible by carrier-induced changes to the dielectric properties of a semiconductor grating. Although the study presented is static, the extension

  1. Optical absorption study of radiation and thermal effects in Brazilian samples of spodumene

    International Nuclear Information System (INIS)

    Isotani, S.; Fujii, A.T.; Antonini, R.; Furtado, W.

    1988-03-01

    A detailed analysis of the optical absorption spectra of five varieties of Brazilian spodumene is presented. The samples were submitted to heat treatments and irradiated with gamma rays, x radiation, electrons and ultraviolet light. (M.C.K.) [pt

  2. Directional Radiometry and Radiative Transfer: the Convoluted Path From Centuries-old Phenomenology to Physical Optics

    Science.gov (United States)

    Mishchenko, Michael I.

    2014-01-01

    This Essay traces the centuries-long history of the phenomenological disciplines of directional radiometry and radiative transfer in turbid media, discusses their fundamental weaknesses, and outlines the convoluted process of their conversion into legitimate branches of physical optics.

  3. Spectroscopic and bolometric measurements of radiation loss in DIVA

    International Nuclear Information System (INIS)

    Shiho, Makoto; Odajima, Kazuo; Sugie, Tatsuo; Maeda, Hikosuke; Kasai, Satoshi

    1977-11-01

    Radiation loss due to low- and high-z impurities in DIVA (JFT-2a) was measured by means of a calibrated 3m grazing incidence vacuum monochromater and a calibrated pyroelectric detector. The following results were obtained: 1) Radiation loss power due to low-z impurities becomes insignificant by using clean surfaces for the vacuum wall. 2) Radiation loss power due to pseudo continuum from high-z impurities has influence on the energy balance of the confined plasma. 3) The divertor reduces the radiation loss by a factor of about 3. (auth.)

  4. The effects of wallerian degeneration of the optic radiations demonstrated by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Savoiardo, M.; Grisoli, M.; Forester, M.; D' Incerti, L.; Farina, L. (Dept. of Neuroradiology, Ist. Nazionale Neurologico C. Besta, Milan (Italy)); Pareyson, D. (Dept. of Neurology, Ist. Nazionale Neurologico C. Besta, Milan (Italy))

    1992-08-01

    The effects of wallerian degeneration can be demonstrated by MRI as abnormal signal along the course of the degenerate fibres; they have previously been reported in the corticospinal tract. We report two cases of wallerian degeneration of the right optic radiations due to lesions of the right lateral geniculate body. The anatomy and the MRI visibility of the normal optic radiations are briefly discussed. (orig.).

  5. Directional radiometry and radiative transfer: The convoluted path from centuries-old phenomenology to physical optics

    International Nuclear Information System (INIS)

    Mishchenko, Michael I.

    2014-01-01

    This Essay traces the centuries-long history of the phenomenological disciplines of directional radiometry and radiative transfer in turbid media, discusses their fundamental weaknesses, and outlines the convoluted process of their conversion into legitimate branches of physical optics. - Highlights: • History of phenomenological radiometry and radiative transfer is described. • Fundamental weaknesses of these disciplines are discussed. • The process of their conversion into legitimate branches of physical optics is summarized

  6. The effects of wallerian degeneration of the optic radiations demonstrated by MRI

    International Nuclear Information System (INIS)

    Savoiardo, M.; Grisoli, M.; Forester, M.; D'Incerti, L.; Farina, L.; Pareyson, D.

    1992-01-01

    The effects of wallerian degeneration can be demonstrated by MRI as abnormal signal along the course of the degenerate fibres; they have previously been reported in the corticospinal tract. We report two cases of wallerian degeneration of the right optic radiations due to lesions of the right lateral geniculate body. The anatomy and the MRI visibility of the normal optic radiations are briefly discussed. (orig.)

  7. Electro-optical and Magneto-optical Sensing Apparatus and Method for Characterizing Free-space Electromagnetic Radiation

    Science.gov (United States)

    Zhang, Xi-Cheng; Riordan, Jenifer Ann; Sun, Feng-Guo

    2000-08-29

    Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric (or magnetic) field and a laser beam in an electro-optic (or magnetic-optic) crystal. In addition to a practical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field-optical beam interaction length, thereby making imaging applications practical.

  8. Depth-of-field effects in wiggler radiation sources: Geometrical versus wave optics

    Directory of Open Access Journals (Sweden)

    Richard P. Walker

    2017-02-01

    Full Text Available A detailed analysis is carried out of the optical properties of synchrotron radiation emitted by multipole wigglers, concentrating on the effective source size and brightness and the so-called “depth of field” effects, concerning which there has been some controversy in the literature. By comparing calculations made with both geometrical optics and wave optics methods we demonstrate that the two approaches are not at variance, and that the wave optics results tend towards those of geometrical optics under well-defined conditions.

  9. Radiation-induced optic neuropathy 4 years after radiation: report of a case followed up with MRI

    International Nuclear Information System (INIS)

    Piquemal, R.; Renard, J.P.; Cottier, J.P.; Herbreteau, D.; Arsene, S.; Rospars, C.; Lioret, E.; Jan, M.

    1998-01-01

    We report a case of radiation-induced optic neuropathy in a 32-year-old man with Cushing's disease and a recurrent tumour of the left cavernous sinus. The patient experienced rapid, painless loss of vision 4 years after treatment without recurrence of tumour or other visual disorder. MRI showed enlargement and contrast enhancement of the optic chiasm. A year later the patient was almost blind and MRI showed atrophy and persistent contrast enhancement of the chiasm. (orig.)

  10. X-ray diffraction and imaging with a coherent beam: application to X-ray optical elements and to crystals exhibiting phase inhomogeneities

    International Nuclear Information System (INIS)

    Masiello, F.

    2011-05-01

    The exceptional properties of synchrotron light sources have been exploited in very different disciplines, from archaeology to chemistry, from material science to biology, from medicine to physics. Among these properties it is important to mention the high brilliance, continuum spectrum, high degree of polarization, time structure, small source size and divergence of the beam, the last resulting in a high transversal coherence of the produced radiation. This high transversal coherence of the synchrotron sources has permitted the development of new techniques, e.g. phase contrast imaging, X-ray photon correlation spectroscopy and coherent X-ray diffraction imaging (CXDI). This thesis work will consist essentially of three parts. In the first part it will be presented the work done as a member of the X-ray Optics Group of ESRF in the characterization of high quality diamond crystals foreseen as X-ray optical elements. The characterization has been done using different complementary X-ray techniques, such as high resolution diffraction, topography, grazing incidence diffraction, reflectivity and measurements of the coherence preservation using the Talbot effect. In the second part, I will show the result obtained in the study of the temperature behaviours of the domain in periodically poled ferroelectrics crystals. This type of measurements, based on Bragg-Fresnel diffraction, are possible only thanks to the high degree of coherence of the beam. In the third part, I will present the results obtained in the characterization of diamonds foreseen for applications other than X-ray optical elements. (author)

  11. Importance of representing optical depth variability for estimates of global line-shaped contrail radiative forcing.

    Science.gov (United States)

    Kärcher, Bernd; Burkhardt, Ulrike; Ponater, Michael; Frömming, Christine

    2010-11-09

    Estimates of the global radiative forcing by line-shaped contrails differ mainly due to the large uncertainty in contrail optical depth. Most contrails are optically thin so that their radiative forcing is roughly proportional to their optical depth and increases with contrail coverage. In recent assessments, the best estimate of mean contrail radiative forcing was significantly reduced, because global climate model simulations pointed at lower optical depth values than earlier studies. We revise these estimates by comparing the probability distribution of contrail optical depth diagnosed with a climate model with the distribution derived from a microphysical, cloud-scale model constrained by satellite observations over the United States. By assuming that the optical depth distribution from the cloud model is more realistic than that from the climate model, and by taking the difference between the observed and simulated optical depth over the United States as globally representative, we quantify uncertainties in the climate model's diagnostic contrail parameterization. Revising the climate model results accordingly increases the global mean radiative forcing estimate for line-shaped contrails by a factor of 3.3, from 3.5 mW/m(2) to 11.6 mW/m(2) for the year 1992. Furthermore, the satellite observations and the cloud model point at higher global mean optical depth of detectable contrails than often assumed in radiative transfer (off-line) studies. Therefore, we correct estimates of contrail radiative forcing from off-line studies as well. We suggest that the global net radiative forcing of line-shaped persistent contrails is in the range 8-20 mW/m(2) for the air traffic in the year 2000.

  12. Implementation of European Directive on Optical Radiation Safety takes place in May 2010

    NARCIS (Netherlands)

    Wieringa, F.P.

    2009-01-01

    At the latest by May 10th 2010, Directive 2006/25/EC regarding the exposure of workers to risks arising from artificial optical radiation must be implemented by all EU-member states, thus legally adopting ICNIRP limit values for ultraviolet, visible and infrared radiation. For IUVA-members the

  13. Reflected Sunlight Reduction and Characterization for a Deep-Space Optical Receiver Antenna (DSORA)

    Science.gov (United States)

    Clymer, B. D.

    1990-01-01

    A baffle system for the elimination of first-order specular and diffuse reflection of sunlight from the sunshade of a deep-space optical receiver telescope is presented. This baffle system consists of rings of 0.5cm blades spaced 2.5 cm apart on the walls of GO hexagonal sunshade tubes that combine to form the telescope sunshade. The shadow cast by the blades, walls, and rims of the tubes prevent all first-order reflections of direct sunlight from reaching the primary mirror of the telescope. A reflection model of the sunshade without baffles is also presented for comparison. Since manufacturers of absorbing surfaces do not measure data near grazing incidence, the reflection properties at anticipated angles of incidence must be characterized. A description of reflection from matte surfaces in term of bidirectional reflection distribution function (BRDF) is presented along with a discussion of measuring BRDF near grazing incidence.

  14. Radiation effects on optical components of a laser radar sensor designed for remote metrology in ITER

    International Nuclear Information System (INIS)

    Menon, M.M.; Grann, E.B.; Slotwinski, A.

    1997-09-01

    A frequency modulated laser radar is being developed for in-vessel metrology and viewing of plasma-facing surfaces. Some optical components of this sensor must withstand intense gamma radiation (3 x 10 6 rad/h) during operation. The authors have tested the effect of radiation on a silica core polarization maintaining optical fiber and on TeO 2 crystals at doses up to ∼ 10 9 rad. Additional tests are planned for evaluating the performance of a complete acousto-optic (AO) scanning device. The progress made in these tests is also described

  15. Measurement of radiation damage on an epoxy-based optical glue

    International Nuclear Information System (INIS)

    Huang, H.C.; Peng, K.C.; Sahu, S.K.; Ueno, K.; Chang, Y.H.; Wang, C.H.; Hou, W.S.

    1997-01-01

    We measured the radiation damage on an optical glue called Eccobond-24, which is a candidate for CsI and BGO crystal calorimeters of the BELLE detector of the KEK B-factory. Absorption spectrophotometry in the range 300-800 nm was used to monitor the radiation damage. The maximum equivalent dose was 1.64 Mrad. The glue shows effects of damage, but is acceptable for the radiation level in the above-mentioned experiment. (orig.)

  16. Nonlinear-optical generation of short-wavelength radiation controlled by laser-induced interference structures

    International Nuclear Information System (INIS)

    Popov, A K; Kimberg, V V

    1998-01-01

    A study is reported of the combined influence of laser-induced resonances in the energy continuum, of splitting of discrete resonances in the field of several strong radiations, and of absorption of the initial and generated radiations on totally resonant parametric conversion to the short-wavelength range. It is shown that the radiation power can be increased considerably by interference processes involving quantum transitions. (nonlinear optical phenomena and devices)

  17. Optical radiation emitted by a silver surface bombarded by low-energy electrons

    International Nuclear Information System (INIS)

    Miserey, F.; Lebon, P.; Septier, A.; Trehin, F.; Beaugrand, C.

    1975-01-01

    Thick silver targets are obtained on flat glass discs by evaporation in a UHV cell (p -10 torr) and their optical coefficients measured by ellipsometry. A field-emission electron gun bombards a limited region of the target, corresponding to the entry pupil of a light spectrometer. Radiation emitted in the domain 250-600nm is analyzed for both normal and parallel polarizations. Spectral distributions of photons are obtained by using a very sensitive counting device including a multi channel analyzer. First experimental results concerning optical radiation generated by 6keV electrons are reported and compared to Transition Radiation and Bremsstrahlung theoretical spectra [fr

  18. Objective evaluation of improvement in optic neuropathy following radiation therapy for thyroid eye disease

    International Nuclear Information System (INIS)

    Rush, Stephen; Winterkorn, Jacqueline; Zak, Rochelle

    2000-01-01

    Purpose: While the literature supports the use of radiation therapy for thyroid eye disease, it does not sufficiently describe in detail the results of radiation therapy for optic neuropathy associated with thyroid eye disease. The objective of this study is to quantify the changes in parameters of optic neuropathy after orbital irradiation for thyroid eye disease. Methods and Materials: Twelve consecutive patients with optic neuropathy from thyroid eye disease were followed by a single neuro-ophthalmology practice and treated by one radiation oncologist with radiation therapy from 1991 through 1995. All cases were prospectively followed for visual acuity, color vision, mean deviation, and/or foveal sensitivity and afferent pupillary defect. All patients received 2000 cGy in 10 fractions with megavoltage irradiation to the orbits. Results: Ten of 12 patients were evaluated for follow-up (one moved out of this country and one had a stroke, which confounded interpretation of examination results). An analysis was performed retrospectively while treatment and evaluation remained uniform. Five men and five women formed the basis of this study with a median age of 60 years (35-76 years). Nineteen eyes were evaluated for thyroid optic neuropathy. Improvement in optic nerve function occurred in eight of ten patients. Improvement was seen either during radiotherapy or within 2 weeks of completion. No long-term adverse effects were noted. Conclusion: This study objectively demonstrates improvement in optic neuropathy from radiation therapy for thyroid eye disease

  19. Effects of Polarization–Maintaining Fibre Degrading on Precision of Fibre Optic Gyroscopes in Radiation Environment

    International Nuclear Information System (INIS)

    Wen, Xiao; De-Wen, Liu; Yang, Liu; Xiao-Su, Yi; Lin, Cong

    2008-01-01

    In the space environment, the precision of fibre optic gyroscopes (FOGs) degrades because of space radiation. Photonic components of FOGs are affected by radiation, especially the polarization-maintaining (PM) fibre coil. In relation to the space radiation environment characteristic, we have carried out a series of radiation experiments on a PM fibre coil with 60 Co radiation source at different dose rates. Based on the experimental results, the formula between the PM-fibre loss and radiation dose rate is built, and the relation between the precision of FOG and radiation dose is obtained accordingly. The results strongly show that the precision of our FOG degrades owing to the attenuation of the polarization-maintaining fibre, which provides theoretical foundation for the radiation-resistant design of the FOG

  20. Multi-dimensional fiber-optic radiation sensor for ocular proton therapy dosimetry

    International Nuclear Information System (INIS)

    Jang, K.W.; Yoo, W.J.; Moon, J.; Han, K.T.; Park, B.G.; Shin, D.; Park, S-Y.; Lee, B.

    2012-01-01

    In this study, we fabricated a multi-dimensional fiber-optic radiation sensor, which consists of organic scintillators, plastic optical fibers and a water phantom with a polymethyl methacrylate structure for the ocular proton therapy dosimetry. For the purpose of sensor characterization, we measured the spread out Bragg-peak of 120 MeV proton beam using a one-dimensional sensor array, which has 30 fiber-optic radiation sensors with a 1.5 mm interval. A uniform region of spread out Bragg-peak using the one-dimensional fiber-optic radiation sensor was obtained from 20 to 25 mm depth of a phantom. In addition, the Bragg-peak of 109 MeV proton beam was measured at the depth of 11.5 mm of a phantom using a two-dimensional sensor array, which has 10×3 sensor array with a 0.5 mm interval.

  1. Long term bleaching of optical glasses darkened by Co60 ionizing radiation

    International Nuclear Information System (INIS)

    Wirtenson, G.R.; White, R.H.

    1997-01-01

    Typical camera designs include optical glass elements that may be affected by the ionizing radiation present in the natural space environment. Ordinary optical glasses darken at low (10(to the 3rd power) rad) dose levels when exposed to ionizing radiation. This darkening decreases the sensitivity of optical sensors. Optical glass flats of FK 51, LaK 0, PK 51A, and ZK Ny were exposed to a 10.6 krad dose of ionizing radiation. Spectrophotometer traces determined the transmittance of the samples as a function of wavelength in the range 350 to 850 nm before and at various time intervals after the irradiation. These measured values were then use to evaluate the rate of recovery or ''bleaching'' of the exposed samples. To prevent accelerated bleaching, the samples were kept at room temperature and away from light, except during measurement. Tables of the measured data and plots of the transmissivity vs. wavelength at various times after irradiation are presented

  2. Radiation-induced transient attenuation of optical fibers at 800 and 1300 nm

    International Nuclear Information System (INIS)

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

    1987-01-01

    Radiation-induced absorption in optical fibers has been a subject of considerable interest throughout the world. As availability and applications of fibers have evolved from ''first window'' systems operating near 850 nm to ''second window'' systems near 1300 nm, interest in wavelength dependence of radiation effects in optical fibers has similarly evolved. The present work summarizes second-window, radiation-induced transient absorption measurements in optical fibers for times shorter than 5 μs. Comparisons to first window data for these fibers are also presented. Only high purity silica fibers with low-OH concentrations were used in the present study to avoid the large OH absorption band in this region. This paper also collects first window data on several high-OH optical fibers

  3. Advanced lightweight optics development for space applications

    International Nuclear Information System (INIS)

    Bilbro, James W.

    1998-01-01

    A considerable amount of effort over the past year has been devoted to exploring ultra-lightweight optics for two specific NASA programs, the Next Generation Space Telescope (NGST), and the High Throughput X-ray Spectrometer (HTXS). Experimental investigations have been undertaken in a variety of materials including glass, composites, nickel, beryllium, Carbon fiber reinforced Silicon Carbide (CSiC), Reaction Bonded Silicon Carbide, Chemical Vapor Deposited Silicon Carbide, and Silicon. Overall results of these investigations will be summarized, and specific details will be provided concerning the in-house development of ultra-lightweight nickel replication for both grazing incidence and normal incidence optics. This will include x-ray test results of the grazing incidence optic and cryogenic test results of the normal incidence optic. The status of two 1.5 meter diameter demonstration mirrors for NGST will also be presented. These two demonstrations are aimed at establishing the capability to manufacture and test mirrors that have an areal density of 15 kilograms per square meter. Efforts in thin membrane mirrors and Fresnel lenses will also be briefly discussed

  4. Fused Silica Final Optics for Inertial Fusion Energy: Radiation Studies and System-Level Analysis

    International Nuclear Information System (INIS)

    Latkowski, Jeffery F.; Kubota, Alison; Caturla, Maria J.; Dixit, Sham N.; Speth, Joel A.; Payne, Stephen A.

    2003-01-01

    The survivability of the final optic, which must sit in the line of sight of high-energy neutrons and gamma rays, is a key issue for any laser-driven inertial fusion energy (IFE) concept. Previous work has concentrated on the use of reflective optics. Here, we introduce and analyze the use of a transmissive final optic for the IFE application. Our experimental work has been conducted at a range of doses and dose rates, including those comparable to the conditions at the IFE final optic. The experimental work, in conjunction with detailed analysis, suggests that a thin, fused silica Fresnel lens may be an attractive option when used at a wavelength of 351 nm. Our measurements and molecular dynamics simulations provide convincing evidence that the radiation damage, which leads to optical absorption, not only saturates but that a 'radiation annealing' effect is observed. A system-level description is provided, including Fresnel lens and phase plate designs

  5. Monochromatization of synchrotron radiation for studies in photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Murty, P.S.

    1981-01-01

    Synchrotron radiation provides a tunable photon source which bridges the wavelength gap between HeI and AlKsub(α) radiation sources in photoelectron spectroscopy. The essential component for using synchrotron radiation is a monochromator. Some design features of the monochromators fabricated at Stanford, U.S.A., and Orsay, France, are described. The Stanford monochromator is a silicon crystal monochromator yielding 8 keV X-ray beam and is used with SPEAR storage ring facility, while the Orsay monochromator is a grazing incidence grating monochromator used for UPS studies. (M.G.B.)

  6. Geometric characteristics of aberrations of plane-symmetric optical systems

    International Nuclear Information System (INIS)

    Lu Lijun; Deng Zhiyong

    2009-01-01

    The geometric characteristics of aberrations of plane-symmetric optical systems are studied in detail with a wave-aberration theory. It is dealt with as an extension of the Seidel aberrations to realize a consistent aberration theory from axially symmetric to plane-symmetric systems. The aberration distribution is analyzed with the spot diagram of a ray and an aberration curve. Moreover, the root-mean-square value and the centroid of aberration distribution are discussed. The numerical results are obtained with the focusing optics of a toroidal mirror at grazing incidence.

  7. Fiber optics in the BNL Booster radiation environment

    International Nuclear Information System (INIS)

    Beadle, E.R.

    1991-01-01

    The Booster instrumentation uses analog and digital fiber optic links, designed to withstand at least 50 krads without performance degradation. The links use inexpensive and commercially available components that operate at a center wavelength of 820 nm. The analog link operates to 30 MHz over a 200 m fiber and can provide insertion gain. The digital link provides 60 ns timing pulses without the dispersive effects of coaxial cables. The optical fiber is a step-index hard clad silica type with a 200 micron core. This paper presents the component selection criteria, link design, installation, testing and performance for the optical links in the Booster instrumentation systems

  8. Eye exposure to optical radiation in the glassblowing industry: an investigation in southern Ontario.

    Science.gov (United States)

    Oriowo, O M; Chou, B R; Cullen, A P

    2000-01-01

    To investigate if the levels of optical radiation hazards in glassblowing are well classified according to the hazard types defined in the Canadian Standards Association (CSA) standard for industrial eye protectors. We carried out radiometric measurements, and questionnaire survey in 4 university glassblowing laboratories, and 3 private studios. There is exposure to low levels of UV and IR radiation in all glassblowing operations. A supra-threshold IR radiation level exists in the craft glassblowing. The use of eye protectors is based on past experience regardless of the level of ocular exposure. Optical radiation hazards exist in both craft and scientific glassblowing. There seems to be an inadequate understanding about radiation types encountered by glassblowers.

  9. Radiation hardening of optical fibers and fiber sensors for space applications: recent advances

    Science.gov (United States)

    Girard, S.; Ouerdane, Y.; Pinsard, E.; Laurent, A.; Ladaci, A.; Robin, T.; Cadier, B.; Mescia, L.; Boukenter, A.

    2017-11-01

    In these ICSO proceedings, we review recent advances from our group concerning the radiation hardening of optical fiber and fiber-based sensors for space applications and compare their benefits to state-of-the-art results. We focus on the various approaches we developed to enhance the radiation tolerance of two classes of optical fibers doped with rare-earths: the erbium (Er)-doped ones and the ytterbium/erbium (Er/Yb)-doped ones. As a first approach, we work at the component level, optimizing the fiber structure and composition to reduce their intrinsically high radiation sensitivities. For the Erbium-doped fibers, this has been achieved using a new structure for the fiber that is called Hole-Assisted Carbon Coated (HACC) optical fibers whereas for the Er/Ybdoped optical fibers, their hardening was successfully achieved adding to the fiber, the Cerium element, that prevents the formation of the radiation-induced point defects responsible for the radiation induced attenuation in the infrared part of the spectrum. These fibers are used as part of more complex systems like amplifiers (Erbium-doped Fiber Amplifier, EDFA or Yb-EDFA) or source (Erbium-doped Fiber Source, EDFS or Yb- EDFS), we discuss the impact of using radiation-hardened fibers on the system radiation vulnerability and demonstrate the resistance of these systems to radiation constraints associated with today and future space missions. Finally, we will discuss another radiation hardening approach build in our group and based on a hardening-by-system strategy in which the amplifier is optimized during its elaboration for its future mission considering the radiation effects and not in-lab.

  10. Retinal, optic nerve and chiasmal function following radiation therapy demonstrated by visual evoked response testing

    International Nuclear Information System (INIS)

    Soni, A.B.; Constine, L.S.; Smith, D.; Palisca, M.; Ojomo, K.; Muhs, A.

    1997-01-01

    Purpose: To evaluate the tolerance of the retina, optic nerve, and optic chiasm to radiation doses conventionally used to treat patients with primary brain or pituitary tumors and to explore the character of detectable radiation effects. Visual evoked response (VER) testing is a noninvasive and sensitive method for identifying radiation injury to the visual system due to alterations in small vessel or myelin integrity. Such evaluations may increase our understanding of the threshold for and the pathogenesis of radiation injury. Materials and Methods: Twenty-four patients irradiated for brain or pituitary tumors between 1972 and 1996 had VER testing. Patients were included in study if the retina, optic nerves or chiasm were in the radiation (RT) field. At the time of RT patients ranged in age from 1.5 to 55 years (median 33). Mean doses were as follows: right retina, 29 Gy (range 10 - 60 Gy); left retina, 29.5 Gy (range 10 - 60 Gy); right optic nerve, 42.9 Gy (range 10 - 60 Gy); left optic nerve, 42.6 Gy (range 10 - 60 Gy); and optic chiasm, 48.2 Gy (range 10 - 65 Gy). Daily fractionation ranged from 1.5 to 1.8 Gy. Pattern VER testing distinguishes compressive or ischemic effects of tumor on the visual system from radiation retinopathy or optic neuropathy on the basis of the conduction amplitude and delay pattern. Prechiasm, chiasm, and postchiasm injuries are distinguishable by analyzing VER changes. Four evoked responses were obtained for each eye, each representing the average of 100 stimulus reversals. Results: VER was normal in 11 patients and abnormal in 13 patients. Only 2 patients (8%) had VER evidence of radiation injury to the visual system, one of whom had visual compromise. The other 11 abnormal patients had characteristic VER changes attributable to tumor or surgical damage. There was no significant difference in the radiation doses given to any subgroup. The one patient with radiation retinopathy had received 55-60 Gy to the posterior globe. Ten years

  11. Radiation resistance of GeO2-doped silica core optical fibers

    International Nuclear Information System (INIS)

    Shibata, Shuichi; Nakahara, Motohiro; Omori, Yasuharu

    1985-01-01

    Effects of hlogen addition to silica glass on the loss in optical fibers are examined by using halogen-free, chlorine-containing and fluorine-containing GeO 2 -doped silica core optical fibers. Measurements are made for dependence of induced loss in these optical fibers on various factors such as wavelength and total dose of gamma radiation as well as GeO 2 content. Ultraviolet absorption spectra are also observed. In addition, effects of halogens added to pure silica fibers are considered on the basis of Raman spectra of three different optical fibers (pure, F-doped, and F- and GeO 2 -codoped silica core). Thus, it is concluded that (1) addition of halogens (F and Cl) serves to decrease GeO defects and Ge(3) defects in GeO 2 -doped silica optical fibers ; (2) addition of halogens suppresses the increase in loss in GeO 2 -doped silica optical fibers induced by gamma radiation ; and (3) there are close relations between the increase in loss induced by gamma radiation and defects originally existing in the fibers. Effects of halogens added to GeO 2 -doped and pure silica optical fibers can be explained on the basis of the latter relations. (Nogami, K.)

  12. Irradiation tests of radiation resistance optical fibers for fusion diagnostic application

    Science.gov (United States)

    Kakuta, Tsunemi; Shikama, Tatsuo; Nishitani, Takeo; Yamamoto, Shin; Nagata, Shinji; Tsuchiya, Bun; Toh, Kentaro; Hori, Junichi

    2002-11-01

    To promote development of radiation-resistant core optical fibers, the ITER-EDA (International Thermonuclear Experimental Reactor-Engineering Design Activity) recommended carrying out international round-robin irradiation tests of optical fibers to establish a reliable database for their applications in the ITER plasma diagnostics. Ten developed optical fibers were irradiation-tested in a Co-60 gamma cell, a Japan Materials Testing Reactor (JMTR). Also, some of them were irradiation tested in a fast neutron irradiation facility of FNS (Fast Neutron Source), especially to study temperature dependence of neutron-associated irradiation effects. Included were several Japanese fluorine doped fibers and one Japanese standard fiber (purified and undoped silica core), as well as seven Russian fibers. Some of Russian fibers were drawn by Japanese manufactures from Russian made pre-form rods to study effects of manufacturing processes to radiation resistant properties. The present paper will describe behaviors of growth of radiation-induced optical transmission loss in the wavelength range of 350-1750nm. Results indicate that role of displacement damages by fast neutrons are very important in introducing permanent optical transmission loss. Spectra of optical transmission loss in visible range will depend on irradiation temperatures and material parameters of optical fibers.

  13. Effect of ionizing radiation on in situ Raman scattering and photoluminescence of silica optical fibers

    International Nuclear Information System (INIS)

    Bilodeau, T.G.; Ewing, K.J.; Nau, G.M.; Aggarwal, I.D.

    1995-01-01

    Raman fiber optic chemical sensors provide remote situ characterization capability. One application of Raman fiber optic chemical sensors is the characterization of the contents of nuclear waste tanks. In these tanks it is expected that approximately 20 meters of optical fiber will be exposed to radiation levels between 100 and 1,000 rads/hour. In support of this work two silica optical fiber types (one a communications grade fiber and the other nominally radiation resistant) have been tested at the radiation levels expected in the tanks. Luminescence and Raman scattering measurements have been performed in situ with 488-nm excitation on two types of silica optical fiber exposed to a constant low to moderate dose rate of gamma radiation of 880 rads(Si)/hour from a 60 Co source for a total dose of greater than 45 krads. The nominally radiation-resistant fiber was also excited with 514.5-nm and near-infrared 830-nm laser radiation. The rate of the silica Raman signal decrease is more than three times greater for the visible excitation wavelengths than for the 830-nm excitation for the radiation resistant fiber. The behavior of the 650-nm photoluminescence line upon irradiation was different for the two fibers studied, both in terms of the shift of the 650-nm line and rate of increase of the normalized photoluminescence intensity. In all cases the photoluminescence from the fibers was less than the Raman intensity. No radioluminescence was observed in either fiber. The radiation resistant fiber exhibited photo bleaching effects on the Raman transmission when photoannealed with 488-nm laser light

  14. Effect of ionizing radiation on in situ Raman scattering and photoluminescence of silica optical fibers

    Science.gov (United States)

    Bilodeau, T. G.; Ewing, K. J.; Nau, G. M.; Aggarwai, I. D.

    1995-02-01

    Raman fiber optic chemical sensors provide remote in situ characterization capability. One application of Raman fiber optic chemical sensors is the characterization of the contents of nuclear waste tanks. In these tanks it is expected that approximately 20 meters of optical fiber will be exposed to radiation levels between 100 and 1000 rads/hour. In support of this work two silica optical fiber types (one a communications grade fiber and the other nominally radiation resistant) have been tested at the radiation levels expected in the tanks. Luminescence and Raman scattering measurements have been performed in situ with 488-nm excitation on two types of silica optical fiber exposed to a constant low to moderate dose rate of gamma radiation of 880 rads(Si)/hour from a /sup 60/Co source for a total dose of greater than 45 krads. The nominally radiation-resistant fiber was also excited with 514.5-nm and near-infrared 830-nm laser radiation. The rate of the silica Raman signal decrease is more than three times greater for the visible excitation wavelengths than for the 830-nm excitation for the radiation resistant fiber. The behavior of the 650-nm photoluminescence line upon irradiation was different for the two fibers studied, both in terms of the shift of the 650-nm line and rate of increase of the normalized photoluminescence intensity. In all cases the photoluminescence from the fibers was less than the Raman intensity. No radioluminescence was observed in either fiber. The radiation resistant fiber exhibited photobleaching effects on the Raman transmission when photoannealed with 488-nm laser light.

  15. A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi [Soonchunhyang Univ., Asan (Korea, Republic of)

    2016-10-15

    In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research.

  16. A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

    International Nuclear Information System (INIS)

    Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi

    2016-01-01

    In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research

  17. Optical Real-Time Space Radiation Monitor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Real-time dosimetry is needed to provide immediate feedback, so astronauts can minimize their exposure to ionizing radiation during periods of high solar activity....

  18. Application of Faraday rotator to suppression of target-reflected radiation in the optical path of a laser installation

    International Nuclear Information System (INIS)

    Bykovskiy, N.E.; Denus, S.; Dubik, A.; Ovsik, Y.; Lisunov, V.V.; Senatskiy, Y.V.; Fedotov, S.I.

    1988-01-01

    The interaction conditions between powerful laser radiation and a target are examined together with the Faraday rotators designed for suppressing target-reflected backward radiation in the neodymium glass laser optical path

  19. Active control of electromagnetic radiation through an enhanced thermo-optic effect

    Science.gov (United States)

    Sheng, Chong; Liu, Hui; Zhu, Shining; Genov, Dentcho A.

    2015-01-01

    The control of electromagnetic radiation in transformation optical metamaterials brings the development of vast variety of optical devices. Of a particular importance is the possibility to control the propagation of light with light. In this work, we use a structured planar cavity to enhance the thermo-optic effect in a transformation optical waveguide. In the process, a control laser produces apparent inhomogeneous refractive index change inside the waveguides. The trajectory of a second probe laser beam is then continuously tuned in the experiment. The experimental results agree well with the developed theory. The reported method can provide a new approach toward development of transformation optical devices where active all-optical control of the impinging light can be achieved. PMID:25746689

  20. Revisiting Bragg's X-ray microscope: scatter based optical transient grating detection of pulsed ionising radiation.

    Science.gov (United States)

    Fullagar, Wilfred K; Paganin, David M; Hall, Chris J

    2011-06-01

    Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Measurement of Sub-Picosecond Electron Bunches via Electro-Optic Sampling of Coherent Transition Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Timothy John [Northern Illinois U.

    2012-01-01

    Future collider applications as well as present high-gradient laser plasma wakefield accelerators and free-electron lasers operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation or the bunch wakefields with sub-picosecond time resolution. We present results on the single-shot electro-optic spectral decoding of coherent transition radiation from bunches generated at the Fermilab A0 photoinjector laboratory. A longitudinal double-pulse modulation of the electron beam is also realized by transverse beam masking followed by a transverse-to-longitudinal phase-space exchange beamline. Live profile tuning is demonstrated by upstream beam focusing in conjunction with downstream monitoring of single-shot electro-optic spectral decoding of the coherent transition radiation.

  2. A radiometric model of an earth radiation budget radiometer optical system with diffuse-specular surfaces

    Science.gov (United States)

    Luther, M. R.

    1981-01-01

    The Earth Radiation Budget Experiment (ERBE) is to fly on NASA's Earth Radiation Budget Satellite (ERBS) and on NOAA F and NOAA G. Large spatial scale earth energy budget data will be derived primarily from measurements made by the ERBE nonscanning instrument (ERBE-NS). A description is given of a mathematical model capable of simulating the radiometric response of any of the ERBE-NS earth viewing channels. The model uses a Monte Carlo method to accurately account for directional distributions of emission and reflection from optical surfaces which are neither strictly diffuse nor strictly specular. The model computes radiation exchange factors among optical system components, and determines the distribution in the optical system of energy from an outside source. Attention is also given to an approach for implementing the model and results obtained from the implementation.

  3. The optical properties of equatorial cirrus in the pilot radiation observation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Platt, C.M.R.; Young, S.A.; Manson, P.; Patterson, G.R. [CSIRO, Victoria (Australia)] [and others

    1996-04-01

    The development of a sensitive filter radiometer for the Atmospheric Radiation Measurement (ARM) Program has been reported. The aim was to develop a reliable and fast instrument that could be used alongside a lidar to obtain near realtime optical properties of clouds, particularly high ice clouds, as they drifted over an ARM Cloud and Radiation Testbed (CART) site allowing calculation of the radiation divergence in the atmosphere over the site. Obtaining cloud optical properties by the lidar/radiometer, or LIRAD, method was described by Platt et al.; the latter paper also describes a year`s data on mid-latitude cirrus. The optical properties of equatorial cirrus (i.e., cirrus within a few degrees of the equator) have hardly been studied at all. The same is true of tropical cirrus, although a few observations have been reported by Davis and Platt et al.This paper describes obersvations performed on cirrus clouds, analysis methods used, and results.

  4. Hyperbaric oxygen in the treatment of radiation-induced optic neuropathy

    International Nuclear Information System (INIS)

    Guy, J.; Schatz, N.J.

    1986-01-01

    Four patients with radiation-induced optic neuropathies were treated with hyperbaric oxygen. They had received radiation therapy for treatment of pituitary tumors, reticulum cell sarcoma, and meningioma. Two presented with amaurosis fugax before the onset of unilateral visual loss and began hyperbaria within 72 hours after development of unilateral optic neuropathy. Both had return of visual function to baseline levels. The others initiated treatment two to six weeks after visual loss occurred in the second eye and had no significant improvement of vision. Treatment consisted of daily administration of 100% oxygen under 2.8 atmospheres of pressure for 14-28 days. There were no medical complications of hyperbaria. While hyperbaric oxygen is effective in the treatment of radiation-induced optic neuropathy, it must be instituted within several days of deterioration in vision for restoration of baseline function

  5. Radiation tolerant fiber optic humidity sensors for High Energy Physics applications

    CERN Document Server

    Berruti, Gaia Maria; Cusano, Andrea

    This work is devoted to the development of fiber optic humidity sensors to be applied in high-energy physics applications and in particular in experiments currently running at CERN. The high radiation level resulting from the operation of the accelerator at full luminosity can cause serious performance deterioration of the silicon sensors which are responsible for the particle tracking. To increase their lifetime, the sensors must be kept cold at temperatures below 0 C. At such low temperatures, any condensation risk has to be prevented and a precise thermal and hygrometric control of the air filling and surrounding the tracker detector cold volumes is mandatory. The technologies proposed at CERN for relative humidity monitoring are mainly based on capacitive sensing elements which are not designed with radiation resistance characteristic. In this scenario, fiber optic sensors seem to be perfectly suitable. Indeed, the fiber itself, if properly selected, can tolerate a very high level of radiation, optical fi...

  6. Synchrotron radiation and precision mirror metrology with a long trace profiler

    International Nuclear Information System (INIS)

    Qian, S.; Takacs, P.Z.

    1997-08-01

    The Long Trace Profiler (LTP) is in use at several synchrotron radiation (SR) laboratories throughout the world and by a number of manufacturers who specialize in making grazing incidence mirrors for SR customers. Recent improvements in the design and operation of the LTP system have reduced the slope profile error bar to the level of 0.3 microradians RMS over measurement lengths of 0.5 meter. This corresponds to a height error bar on the order of 20 nanometers. This level of performance allows one to measure with confidence the shape of large cylinders and spheres that have kilometer radii of curvature in the axial direction. The LTP is versatile enough to make measurements of a mirror in the face up, sideways, and face down configurations. The authors will illustrate the versatility of the current version of the instrument, the LTP II, and present results from two new versions of the instrument: the in-situ LTP (ISLTP) and the Vertical Scan LTP (VSLTP). Both of them are based on the penta-prism LTP (ppLTP) principle with a stationary optical head and moving penta-prism. The ISLTP is designed to measure the distortion of high heat load mirrors during actual operation in SR beam lines. The VSLTP is designed to measure the complete 3-dimensional shape of x-ray telescope cylinder mirrors and mandrels in a vertical configuration. Scans are done both in the axial direction and in the azimuthal direction

  7. The history and principles of optical computed tomography for scanning 3-D radiation dosimeters: 2008 update

    Energy Technology Data Exchange (ETDEWEB)

    Doran, Simon J [CRUK Clinical Magnetic Resonance Research Group, Institute of Cancer Research, Sutton, Surrey (United Kingdom); Department of Physics, University of Surrey, Surrey (United Kingdom)], E-mail: Simon.Doran@icr.ac.uk

    2009-05-01

    The current status of optical CT for 3-D radiation dosimetry is reviewed. The technique is first placed in its historical context, pointing out the relationship with other methods of optical imaging and showing how optical-CT has emerged independently in several different fields and under different names. The theoretical background of the method is described briefly and this provides the foundation for an explanation of the different types of scanner. The relative advantages and disadvantages of instruments based on scanned lasers and pixelated (area) detectors are presented. The latest generation of 'fast laser scanners' is described and the review is concluded with a discussion of the different radiation-sensitive materials used as samples in optical CT.

  8. Radiation-induced optic neuropathy 4 years after radiation: report of a case followed up with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Piquemal, R.; Renard, J.P. [Service de Medecine Interne A, Hopital Bretonneau, Tours (France); Cottier, J.P.; Herbreteau, D. [Service de Neuroradiologie, Hopital Bretonneau, Tours (France); Arsene, S.; Rospars, C. [Service d`Ophthalmologie, Hopital Bretonneau, Tpurs (France); Lioret, E.; Jan, M. [Service de Neurochirurgie, Hopital Bretonneau, Tours (France)

    1998-07-01

    We report a case of radiation-induced optic neuropathy in a 32-year-old man with Cushing`s disease and a recurrent tumour of the left cavernous sinus. The patient experienced rapid, painless loss of vision 4 years after treatment without recurrence of tumour or other visual disorder. MRI showed enlargement and contrast enhancement of the optic chiasm. A year later the patient was almost blind and MRI showed atrophy and persistent contrast enhancement of the chiasm. (orig.) With 3 figs., 13 refs.

  9. Mixed optical Cherenkov–Bremsstrahlung radiation in vicinity of the Cherenkov cone from relativistic heavy ions: Unusual dependence of the angular distribution width on the radiator thickness

    Energy Technology Data Exchange (ETDEWEB)

    Rozhkova, E.I., E-mail: elenafiks@gmail.com; Pivovarov, Yu.L.

    2016-07-15

    The Cherenkov radiation (ChR) angular distribution is usually described by the Tamm–Frank (TF) theory, which assumes that relativistic charged particle moves uniformly and rectilinearly in the optically transparent radiator. According to the TF theory, the full width at half maximum (FWHM) of the ChR angular distribution inversely depends on the radiator thickness. In the case of relativistic heavy ions (RHI) a slowing-down in the radiator may sufficiently change the angular distribution of optical radiation in vicinity of the Cherenkov cone, since there appears a mixed ChR–Bremsstrahlung radiation. As a result, there occurs a drastic transformation of the FWHM of optical radiation angular distribution in dependence on the radiator thickness: from inversely proportional (TF theory) to the linearly proportional one. In our paper we present the first analysis of this transformation taking account of the gradual velocity decrease of RHI penetrating through a radiator. - Highlights: • Stopping of relativistic heavy ions leads to appearance of a Cherenkov–Bremsstrahlung radiation near the Cherenkov cone. • Mixed Cherenkov–Bremsstrahlung optical radiation FWHM differs from the standard one determined by the Tamm–Frank theory. • The Cherenkov–Bremsstrahlung radiation angular distribution FWHM linearly depends on the radiator thickness.

  10. Radiation tolerant optical links for the readout of the ATLAS experiment

    CERN Document Server

    Pearce, M

    2000-01-01

    The ATLAS experiment will use radiation tolerant optical links to transfer data to and from sub-detector systems. The link specifications can be broadly divided into two classes, represented by the inner tracking detectors and the electromagnetic calorimeter. A feature common to all the readout links is the use of vertical cavity surface emitting laser diodes coupled to multimode optical fibres. Results from the development for both of these environments are reviewed with particular attention bring paid to irradiation studies. (8 refs).

  11. Single interval shortwave radiation scheme with parameterized optical saturation and spectral overlaps

    Czech Academy of Sciences Publication Activity Database

    Mašek, Jan; Geleyn, J.- F.; Brožková, Radmila; Giot, O.; Achom, H. O.; Kuma, P.

    2016-01-01

    Roč. 142, č. 659 (2016), s. 304-326 ISSN 0035-9009 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : shortwave radiative transfer * delta-two stream system * broadband approach * Malkmus band model * optical saturation * idealized optical paths * spectral overlap Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.444, year: 2016

  12. Management of optic pathway and chiasmatic-hypothalamic gliomas in children with radiation therapy

    International Nuclear Information System (INIS)

    Erkal, Haldun Suekrue; Serin, Meltem; Cakmak, Ahmet

    1997-01-01

    Background and purpose: Optic pathway and chiasmatic-hypothalamic gliomas are rare childhood tumors. This study presents the experience in management of these tumors with radiation therapy. Materials and methods: Thirty-three children with the diagnosis of optic pathway and chiasmatic-hypothalamic gliomas were treated with radiation therapy from 1973 through 1994 in the Department of Radiation Oncology at Ankara University Faculty of Medicine. Twenty-four children had optic pathway gliomas and nine had chiasmatic-hypothalamic gliomas. Evidence of neurofibromatosis was present in six children. Subtotal resection was performed in 22 children and a biopsy in seven. The most common prescription for total tumor dose was 50 Gy, delivered in 2 Gy daily fractions. Follow-up ranged from 0.5 to 16.1 years (mean, 13.6 years). Results: Overall, progression-free and cause-specific survival probabilities for the entire group were 93%, 82% and 93%, respectively, at 5 years and 79%, 77% and 88%, respectively, at 10 years. Differences in overall, progression-free and cause-specific survival probabilities between optic pathway and chiasmatic-hypothalamic gliomas were not statistically significant. Absence of evidence of neurofibromatosis correlated with significantly better progression-free and cause-specific survival probabilities. Conclusion: Radiation therapy is effective in stabilization or improvement of vision and prevention of tumor progression in both optic pathway and chiasmatic-hypothalamic gliomas

  13. Hyperbaric oxygenation was effective in a case of radiation-induced optic neuropathy

    International Nuclear Information System (INIS)

    Saitoh, Ayumi; Dake, Yoshinori; Amemiya, Tsugio

    1995-01-01

    A 68-year-old female underwent radiation treatment followed by surgical extirpation for olfactory neuroblastoma in the left ethmoidal sinus. Acute optic neuropathy developed 16 months later in her left eye. The visual acuity was reduced to finger counting at 30 cm. Treatment with systemic corticosteroid and hyperbaric oxygenation for 2 months resulted in improvement in fundus findings and improvement of visual acuity to 0.5. The findings show the potential effectiveness of hyperbaric oxygen therapy for radiation-induced optic neuropathy. (author)

  14. Hyperbaric oxygenation was effective in a case of radiation-induced optic neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, Ayumi; Dake, Yoshinori; Amemiya, Tsugio [Nagasaki Univ. (Japan). School of Medicine

    1995-03-01

    A 68-year-old female underwent radiation treatment followed by surgical extirpation for olfactory neuroblastoma in the left ethmoidal sinus. Acute optic neuropathy developed 16 months later in her left eye. The visual acuity was reduced to finger counting at 30 cm. Treatment with systemic corticosteroid and hyperbaric oxygenation for 2 months resulted in improvement in fundus findings and improvement of visual acuity to 0.5. The findings show the potential effectiveness of hyperbaric oxygen therapy for radiation-induced optic neuropathy. (author).

  15. Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

    Science.gov (United States)

    Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

    2016-06-01

    A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

  16. Dynamics of moving interacting atoms in a laser radiation field and optical size resonances

    International Nuclear Information System (INIS)

    Gadomskii, O.N.; Glukhov, A.G.

    2005-01-01

    The forces acting on interacting moving atoms exposed to resonant laser radiation are calculated. It is shown that the forces acting on the atoms include the radiation pressure forces as well as the external and internal bias forces. The dependences of the forces on the atomic spacing, polarization, and laser radiation frequency are given. It is found that the internal bias force associated with the interaction of atomic dipoles via the reemitted field may play an important role in the dynamics of dense atomic ensembles in a light field. It is shown that optical size resonances appear in the system of interacting atoms at frequencies differing substantially from transition frequencies in the spectrum of atoms. It is noted that optical size resonances as well as the Doppler frequency shift in the spectrum of interacting atoms play a significant role in the processes of laser-radiation-controlled motion of the atoms

  17. Optically pumped carbon dioxide laser mixtures. [using solar radiation

    Science.gov (United States)

    Yesil, O.; Christiansen, W. H.

    1979-01-01

    This work explores the concept of blackbody radiation pumping of CO2 gas as a step toward utilization of solar radiation as a pumping source for laser action. To demonstrate this concept, an experiment was performed in which laser gas mixtures were exposed to 1500 K thermal radiation for brief periods of time. A gain of 2.8 x 10 to the -3rd reciprocal centimeters has been measured at 10.6 microns in a CO2-He gas mixture of 1 Torr pressure. A simple analytical model is used to describe the rate of change of energy of the vibrational modes of CO2 and to predict the gain. Agreement between the prediction and experiment is good.

  18. Gamma radiation effect study in polycarbonate optical and mechanics properties

    International Nuclear Information System (INIS)

    Araujo, E.S. de.

    1991-02-01

    Polycarbonates (PC) are used in different industrial applications due to their excellent dielectric characteristics, impact resistance, and high temperature resistance. In some of these applications, the polycarbonates are exposed to gamma radiation which produces molecular scissions, causing changes in the polycarbonate properties. To estimate the radiation effects in the Durolon polycarbonate, samples were irradiated with 60 Co gamma rays with doses between 0,2 kGy and 300 kGy. The results obtained showed that the PC mechanical properties are not changed due to the gamma radiation. However the results showed an expressive variation in the yellowness index for doses above 1 kGy. The results showed that it is possible to use the gamma sterilization of PC in applications where the coloration of PC is not critical. (author). 21 refs, 25 figs, 3 tabs

  19. Optical materials

    International Nuclear Information System (INIS)

    Poker, D.B.; Ortiz, C.

    1989-01-01

    This book reports on: Diamond films, Synthesis of optical materials, Structure related optical properties, Radiation effects in optical materials, Characterization of optical materials, Deposition of optical thin films, and Optical fibers and waveguides

  20. Distributed Optical Fiber Radiation and Temperature Sensing at High Energy Accelerators and Experiments

    CERN Document Server

    AUTHOR|(CDS)2090137; Brugger, Markus

    The aim of this Thesis is to investigate the feasibility of a distributed optical fiber radiation sensing system to be used at high energy physics accelerators and experiments where complex mixed-field environments are present. In particular, after having characterized the response of a selection of radiation sensitive optical fibers to ionizing radiation coming from a 60Co source, the results of distributed optical fiber radiation measurements in a mixed-field environment are presented along with the method to actually estimate the dose variation. This study demonstrates that distributed optical fiber dosimetry in the above mentioned mixed-field radiation environment is feasible, allowing to detect dose variations of about 10-15 Gy with a 1 m spatial resolution. The proof of principle has fully succeeded and we can now tackle the challenge of an industrial installation taking into account that some optimizations need to be done both on the control unit of the system as well as on the choice of the sensing f...

  1. Evaluation of the Detection Efficiency of LYSO Scintillator in the Fiber-Optic Radiation Sensor

    Directory of Open Access Journals (Sweden)

    Chan Hee Park

    2014-01-01

    Full Text Available The aim of this study was to develop and evaluate fiber-optic sensors for the remote detection of gamma rays in areas that are difficult to access, such as a spent fuel pool. The fiber-optic sensor consists of a light-generating probe, such as scintillators for radiation detection, plastic optical fibers, and light-measuring devices, such as PMT. The (Lu,Y2SiO5:Ce(LYSO:Ce scintillator was chosen as the light-generating probe. The (Lu,Y2SiO5:Ce(LYSO:Ce scintillator has higher scintillation efficiency than the others and transmits light well through an optical fiber because its refraction index is similar to the refractive index of the optical fiber. The fiber-optic radiation sensor using the (Lu,Y2SiO5:Ce(LYSO:Ce scintillator was evaluated in terms of the detection efficiency and reproducibility for examining its applicability as a radiation sensor.

  2. Thermoluminescence characteristics of Ge-doped optical fibers with different dimensions for radiation dosimetry

    International Nuclear Information System (INIS)

    Begum, Mahfuza; Rahman, A.K.M. Mizanur; Abdul-Rashid, H.A.; Yusoff, Z.; Begum, Mahbuba; Mat-Sharif, K.A.; Amin, Y.M.; Bradley, D.A.

    2015-01-01

    Important thermoluminescence (TL) properties of five (5) different core sizes Ge-doped optical fibers have been studied to develop new TL material with better response. These are drawn from same preform applying different speed and tension during drawing phase to produce Ge-doped optical fibers with five (5) different core sizes. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge-doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (SEM) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in Secondary Standard Dosimetry Lab (SSDL) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are TL linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 °C for 1 h period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 h at 400 °C and subsequently 2 h at 100 °C to yield the highest sensitivity. TL responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z eff ) is found in the range (13.25–13.69) which is higher than soft tissue (7.5) however within the range of human-bone (11.6–13.8). All the fibers can also be re-used several times as a detector after annealing. TL properties of the Ge-doped optical fibers indicate promising applications in

  3. A guide to radiation protection in the use of X-ray optics equipment

    International Nuclear Information System (INIS)

    Bines, W.P.

    1986-01-01

    A booklet has been produced by a Working Group convened by the Health and Safety Executive to provide practical guidance for all who might be involved in work with X-ray optics equipment, such as designers, manufacturers, users, maintenance workers, inspectors, radiation protection advisers and supervisors. The particular radiation protection aspects described include those in connection with enclosure design and inspection, inter locks, tube shields, shutters and cover plates, administrative controls, monitoring and repair and maintenance of equipment. (UK)

  4. Determining optical and radiation characteristics of cathode ray tubes' glass to be reused as radiation shielding glass

    International Nuclear Information System (INIS)

    Zughbi, A.; Kharita, M.H.; Shehada, A.M.

    2017-01-01

    A new method of recycling glass of Cathode Ray Tubes (CRTs) has been presented in this paper. The glass from CRTs suggested being used as raw materials for the production of radiation shielding glass. Cathode ray tubes glass contains considerable amounts of environmentally hazardous toxic wastes, namely heavy metal oxides such as lead oxide (PbO). This method makes CRTs glass a favorable choice to be used as raw material for Radiation Shielding Glass and concrete. The heavy metal oxides increase its density, which make this type of glass nearly equivalent to commercially available shielding glass. CRTs glass have been characterized to determine heavy oxides content, density, refractive index, and radiation shielding properties for different Gamma-Ray energies. Empirical methods have been used by using the Gamma-Ray source cobalt-60 and computational method by using the code XCOM. Measured and calculated values were in a good compatibility. The effects of irradiation by gamma rays of cobalt-60 on the optical transparency for each part of the CRTs glass have been studied. The Results had shown that some parts of CRTs glass have more resistant to Gamma radiation than others. The study had shown that the glass of cathode ray tubes could be recycled to be used as radiation shielding glass. This proposed use of CRT glass is only limited to the available quantity of CRT world-wide. - Highlights: • A new method of recycling glass of Cathode Ray Tubes (CRTs) has been presented. • The glass from CRTs used as raw materials for radiation shielding glass. • The resulted glass have good optical properties and stability against radiations.

  5. Radiation Pressure in a Rubidium Optical Lattice: An Atomic Analog to the Photorefractive Effect

    International Nuclear Information System (INIS)

    Guibal, S.; Mennerat-Robilliard, C.; Larousserie, D.; Triche, C.; Courtois, J.; Grynberg, G.

    1997-01-01

    Probe gain in a rubidium optical lattice is observed when the probe and lattice beams have identical frequencies. This effect is shown to arise from the radiation pressure that shifts the atomic density distribution with respect to the optical potential. This effect is compared with two-beam coupling in photorefractive materials. The experimental results obtained by changing the parameters of the optical lattice (intensity, detuning, periodicity) are in reasonable agreement with numerical simulations based on the model case of a 1/2→3/2 atomic transition. copyright 1997 The American Physical Society

  6. Summary of radiation-induced transient absorption and recovery in fiber optic waveguides

    International Nuclear Information System (INIS)

    Skoog, C.D.

    1976-11-01

    The absorption induced in fiber optic waveguides by pulsed electron and X-ray radiation has been measured as a function of optical wavelength from 450 to 950 nm, irradiation temperature from -54 to 71 0 C, and dose from 1 to 500 krads. The fibers studied are Ge-doped silica core fibers (Corning Low Loss), ''pure'' vitreous silica core fibers (Schott, Bell Laboratories, Fiberoptic Cable Corp., and Valtec Fiberoptics), polymethyl-methacrylate core fibers (DuPont CROFON and PFX), and polystyrene core fibers (International Fiber Optics and Polyoptics). Models that have been developed to account for the observed absorption recovery are also summarized

  7. Optical roughness BRDF model for reverse Monte Carlo simulation of real material thermal radiation transfer.

    Science.gov (United States)

    Su, Peiran; Eri, Qitai; Wang, Qiang

    2014-04-10

    Optical roughness was introduced into the bidirectional reflectance distribution function (BRDF) model to simulate the reflectance characteristics of thermal radiation. The optical roughness BRDF model stemmed from the influence of surface roughness and wavelength on the ray reflectance calculation. This model was adopted to simulate real metal emissivity. The reverse Monte Carlo method was used to display the distribution of reflectance rays. The numerical simulations showed that the optical roughness BRDF model can calculate the wavelength effect on emissivity and simulate the real metal emissivity variance with incidence angles.

  8. Optical properties behavior of three optical filters and a mirror used in the internal optical head of a Raman laser spectrometer after exposed to proton radiation

    Science.gov (United States)

    Guembe, V.; Alvarado, C. G.; Fernández-Rodriguez, M.; Gallego, P.; Belenguer, T.; Díaz, E.

    2017-11-01

    The Raman Laser Spectrometer is one of the ExoMars Pasteur Rover's payload instruments that is devoted to the analytical analysis of the geochemistry content and elemental composition of the observed minerals provided by the Rover through Raman spectroscopy technique. One subsystem of the RLS instrument is the Internal Optical Head unit (IOH), which is responsible for focusing the light coming from the laser onto the mineral under analysis and for collecting the Raman signal emitted by the excited mineral. The IOH is composed by 4 commercial elements for Raman spectroscopy application; 2 optical filters provided by Iridian Spectral Technologies Company and 1 optical filter and 1 mirror provided by Semrock Company. They have been exposed to proton radiation in order to analyze their optical behaviour due to this hostile space condition. The proton irradiation test was performed following the protocol of LINES lab (INTA). The optical properties have been studied through transmittance, reflectance and optical density measurements, the final results and its influence on optical performances are presented.

  9. Effect of radiation on the optical properties of some ferroelectrics

    International Nuclear Information System (INIS)

    Pirogova, G.N.; Kritskaya, V.E.; Malov, N.A.; Ryabov, A.I.; Voronin, Y.V.

    1986-01-01

    This paper studies the effect of gamma-irradiation and impulsive irradiation with electrons on the optical properties of crystals used in nonlinear optics: potassium dihydrophosphate KH 2 PO 4 , and cesium dihydroarsenate CsH 2 AsO 4 . The authors used two types of crystals obtained by extraction of the condensate, lowering of the temperature and recirculation. The content of iron-group impurity atoms (A1, Cu, and Mg) were determined with the help of atomic absorption spectrometry and was less than 1.10 -3 mole %. The samples were irradiated with a Co 60 gamma-ray source and impulsive irradiation with electrons was performed with a U-12 linear accelerator. A comparison of the spectra of gamma-irradiated single crystals and crystals irradiated with electrons shows that they are identical in the UV region. The impulse technique, however, enables observing the absorption bands which under gamma-irradiation are lost owing to the large increment of the optical density in the ultraviolet region and the shift of the absorption edge into the long-wavelength region

  10. Development Of Robust IFE Laser Mirrors and Multi-Scale Modeling Of Pulsed Radiation Effects. Final Report

    International Nuclear Information System (INIS)

    Ghoniem, Nasr M.

    2009-01-01

    The following has been achieved: (1) Final design of a Deformable Grazing Incidence Mirror, (2) Formulation of a new approach to model surface roughening under laser illumination, and (3) Modeling of radiation hardening under IFE conditions. We discuss here progress made in each one of these areas. The objectives of the Grazing Incidence Metal Mirror (GIMM) are: (1) to reflect the incident laser beam into the direction of the target; (2) to focus the incident beam directly onto the target (3) to withstand the thermomechanical and damage induced by laser beams; (4) to correct the reflective surface so that the focus is permanently on the target; (5) to have a full range of motion so it can be placed anywhere relative to the target. The design was described in our progress report of the period August 15, 2003 through April 15, 2004. In the following, we describe further improvements of the final design.

  11. Radiation optic neuropathy after megavoltage external-beam irradiation: Analysis of time-dose factors

    International Nuclear Information System (INIS)

    Parsons, J.T.; Bova, F.J.; Million, R.R.

    1994-01-01

    To investigate the risk of radiation-induced optic neuropathy according to total radiotherapy dose and fraction size, based on both retrospective and prospectively collected data. Between October 1964 and May 1989, 215 optic nerves in 131 patients received fractionated external-beam irradiation during the treatment of primary extracranial head and neck tumors. All patients had a minimum of 3 years of ophthalmologic follow-up (range, 3 to 21 years). The clinical end point was visual acuity of 20/100 or worse as a result of optic nerve injury. Anterior ischemic optic neuropathy developed in five nerves (at mean and median times of 32 and 30 months, respectively, and a range of 2-4 years). Retrobulbar optic neuropathy developed in 12 nerves (at mean and median times of 47 and 28 months, respectively, and a range of 1-14 years). No injuries were observed in 106 optic nerves that received a total dose of <59 Gy. Among nerves that received doses of ≥ 60 Gy, the dose per fraction was more important than the total dose in producing optic neuropathy. The 15-year actuarial risk of optic compared with 47% when given in fraction sizes ≥1.9 Gy. The data also suggest an increased risk of optic nerve injury with increasing age. As there is no effective treatment of radiation-induced optic neuropathy, efforts should be directed at its prevention by minimizing the total dose, paying attention to the dose per fraction to the nerve, and using reduced field techniques where appropriate to limit the volume of tissues that receive high-dose irradiation. 32 refs., 5 figs., 5 tabs

  12. Development of wide-area radiation monitor using an optical fiber

    International Nuclear Information System (INIS)

    Kawata, Naoki; Kato, Masatoshi; Baba, Mamoru; Yamadera, Akira; Miura, Takako

    2002-01-01

    We have developed a method for radiation distribution measurement by combining an optical fiber of wave-length shift type with a plastic scintillator, and studied its properties to apply as a wide-area radiation monitor. The detector employs two photomultipliers in both ends of the fiber and locate the radiation position by using the difference of light arrival time from scintillators. We tested the detector with gamma-rays and neutrons concerning with the position-response and pulse-height response of the detector. From the experiment, we confirmed the proper operation of the detector and position response with spatial resolution of 30-60 cm

  13. EC-directive optical radiation - present state of consultation; EG-Richtlinie optische Strahlung - aktueller Beratungsstand

    Energy Technology Data Exchange (ETDEWEB)

    Pipke, R. [Bundesanstalt fuer Arbeitschutz und Arbeitsmedizin, Dortmund (Germany)

    2004-07-01

    The draft of a directive on the protection of workers from risks related to radiation in the range from 100 nm to 1 mm (Laser, UV-radiation) is discussed on EC-level. The European concept of regulations on occupational safety and health is outlined and put into reference with other directives on the protection against physical agents (vibrations, noise, electromagnetic fields). Building up on this the present state of consultation of a directive on optical radiation is represented, including major points of consideration. (orig.)

  14. Radiation-induced transient absorption in single mode optical fibers

    International Nuclear Information System (INIS)

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

    1988-01-01

    This paper reviews the measurements conducted by the Los Alamos National Laboratory in support of these NATO efforts wherein radiation-induced transient absorption was measured over time ranges from a few ns to several μs for two single mode fibers. Experimental conditions were varied to provide data for future development of standarized test conditions for single mode fibers. 8 refs., 11 figs

  15. Interlaboratory comparison of radiation-induced attenuation in optical fibers

    International Nuclear Information System (INIS)

    Friebele, E.J.; Lyons, P.B.; Blackburn, J.C.

    1989-08-01

    A comparison of the losses induced in step index multimode, graded index multimode and single mode fibers by pulsed radiation exposure has been made among 12 laboratories over a period of 5 years. The recoveries of the incremental attenuations from 10 -9 to 10 1 s are reported. Although a standard set of measurement parameters was attempted, differences between the laboratories are evident; possible origins for these are discussed. 18 refs., 18 figs., 7 tabs

  16. A new XUV optical end-station to characterize compact and flexible photonic devices using synchrotron radiation

    Science.gov (United States)

    Marcelli, A.; Mazuritskiy, M. I.; Dabagov, S. B.; Hampai, D.; Lerer, A. M.; Izotova, E. A.; D'Elia, A.; Turchini, S.; Zema, N.; Zuccaro, F.; de Simone, M.; Javad Rezvani, S.; Coreno, M.

    2018-03-01

    In this contribution we present the new experimental end-station to characterize XUV diffractive optics, such as Micro Channel Plates (MCPs) and other polycapillary optics, presently under commission at the Elettra synchrotron radiation laboratory (Trieste, Italy). To show the opportunities offered by these new optical devices for 3rd and 4th generation radiation sources, in this work we present also some patterns collected at different energies of the primary XUV radiation transmitted by MCP optical devices working in the normal incidence geometry.

  17. Proton radiation effects on the optical properties of vertically aligned carbon nanotubes

    Science.gov (United States)

    Kuhnhenn, J.; Khavrus, V.; Leonhardt, A.; Eversheim, D.; Noll, C.; Hinderlich, S.; Dahl, A.

    2017-11-01

    This paper discusses proton-induced radiation effects in vertically aligned carbon nanotubes (VA-CNT). VACNTs exhibit extremely low optical reflectivity which makes them interesting candidates for use in spacecraft stray light suppression. Investigating their behavior in space environment is a precondition for the implementation on a satellite.

  18. Measurement of the optical fiber numeric aperture exposed to thermal and radiation aging

    Science.gov (United States)

    Vanderka, Ales; Bednarek, Lukas; Hajek, Lukas; Latal, Jan; Poboril, Radek; Zavodny, Petr; Vasinek, Vladimir

    2016-12-01

    This paper deals with the aging of optical fibers influenced by temperature and radiation. There are analyzed changes in the structure of the optical fiber, related to the propagation of light in the fiber structure. In this case for numerical aperture. For experimental measurement was used MM fiber OM1 with core diameter 62.5 μm, cladding diameter 125 μm in 2.8 mm secondary coating. Aging of the optical fiber was achieved with dry heat and radiation. For this purpose, we were using a temperature chamber with a stable temperature of 105 °C where the cables after two months. Cables were then irradiated with gamma radiation 60Co in doses of 1.5 kGy and then 60 kGy. These conditions simulated 50 years aging process of optical cables. According to European Standard EN 60793-1-43:2015 was created the automatic device for angular scan working with LabVIEW software interface. Numerical aperture was tested at a wavelength of 850 nm, with an output power 1 mW. Scanning angle was set to 50° with step 0.25°. Numerical aperture was calculated from the position where power has fallen from maximal power at e2 power. The measurement of each sample was performed 10 hours after thermal and radiation aging. The samples were subsequently tested after six months from the last irradiation. In conclusion, the results of the experiment were analyzed and compared.

  19. Computer simulation of the spatial distribution of optical radiation arising from knocked-out excited particles

    International Nuclear Information System (INIS)

    Gokov, S.P.; Gritsyna, V.V.; Koval', A.G.; Kovtunenko, Yu.I.; Shevchenko, D.I.

    2004-01-01

    The new approach for the explanation of the spatial distribution of the optical radiation arising from knocked-out excited particles is given. Calculated and experimental data for Al (λ=396.1 nm) and Mg (λ=383.8 nm) knocked-out by Ar + (20 keV) beam from MgAl 2 O 4 surface are compared [ru

  20. The chemistry of two-component fluoride crystalline optical media for heavy, fast, radiation hard scintillators

    International Nuclear Information System (INIS)

    Sobolev, B.P.; Krivandina, E.A.; Fedorov, P.P.; Vasilchenko, V.G.

    1994-01-01

    Prospects for preparation of two-component dense optical materials for scintillators are shown, using data on phase diagrams of about 300 MF m - RF n (m, n ≤ 4) type systems, formed by metal fluorides. Primary characteristics (decay time and light output of luminescence, radiation hardness, etc.) of some multicomponent crystals are reported

  1. Control of relative radiation pressure in optical traps : application to phagocytic membrane binding studies

    NARCIS (Netherlands)

    Kress, H.; Stelzer, E.H.K.; Griffiths, G.; Rohrbach, A.

    2005-01-01

    We show how to control the relative radiation pressure and thereby the stable trap position of an optically trapped bead by variation of the mean incident axial photon momentum. The thermal position fluctuations of a trapped bead are recorded by a three-dimensional back focal plane interferometry.

  2. Ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate.

    Science.gov (United States)

    Yamamoto, Seiichi; Kamada, Kei; Yoshikawa, Akira

    2018-02-16

    High resolution imaging of radiation is required for such radioisotope distribution measurements as alpha particle detection in nuclear facilities or high energy physics experiments. For this purpose, we developed an ultrahigh resolution radiation imaging system using an optical fiber structure scintillator plate. We used a ~1-μm diameter fiber structured GdAlO 3 :Ce (GAP) /α-Al 2 O 3 scintillator plate to reduce the light spread. The fiber structured scintillator plate was optically coupled to a tapered optical fiber plate to magnify the image and combined with a lens-based high sensitivity CCD camera. We observed the images of alpha particles with a spatial resolution of ~25 μm. For the beta particles, the images had various shapes, and the trajectories of the electrons were clearly observed in the images. For the gamma photons, the images also had various shapes, and the trajectories of the secondary electrons were observed in some of the images. These results show that combining an optical fiber structure scintillator plate with a tapered optical fiber plate and a high sensitivity CCD camera achieved ultrahigh resolution and is a promising method to observe the images of the interactions of radiation in a scintillator.

  3. A new mechanism of ionizing radiation detection for positron emission tomography: modulation of optical properties

    Science.gov (United States)

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-10-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) annihilation photon pair coincidence time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit of around 100 ps. On the other hand, modulation mechanisms of a material's optical properties as exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to study whether ionizing radiation can also produce fast modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5x10-6 is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the radiation source flux rate and average photon energy.

  4. A promising new mechanism of ionizing radiation detection for positron emission tomography: modulation of optical properties

    Science.gov (United States)

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-11-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit for the coincidence time resolution of around 100 ps. On the other hand, modulation mechanisms of the optical properties of a material exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to for the first time study whether ionizing radiation can produce modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5× {{10}-6} is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the detected event rate and average photon energy of the radiation source.

  5. Optical design of a high radiative flux solar furnace for Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Riveros-Rosas, D.; Perez-Rabago, C.A.; Arancibia-Bulnes, C.A.; Jaramillo, O.A.; Estrada, C.A. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Av. Xochicalco s/n, A.P. 34, Temixco, 62580 Morelos (Mexico); Herrera-Vazquez, J.; Vazquez-Montiel, S.; Granados-Agustin, F. [Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro 1, Tonantzintla, A.P. 216, 72000 Puebla (Mexico); Sanchez-Gonzalez, M. [Centro Nacional de Energias Renovables, Calle Somera 7-9, 28026 Madrid (Spain)

    2010-05-15

    In the present work, the optical design of a new high radiative flux solar furnace is described. Several optical configurations for the concentrator of the system have been considered. Ray tracing simulations were carried out in order to determine the concentrated radiative flux distributions in the focal zone of the system, for comparing the different proposals. The best configuration was chosen in terms of maximum peak concentration, but also in terms of economical and other practical considerations. It consists of an arrangement of 409 first surface spherical facets with hexagonal shape, mounted on a spherical frame. The individual orientation of the facets is corrected in order to compensate for aberrations. The design considers an intercepted power of 30 kW and a target peak concentration above 10,000 suns. The effect of optical errors was also considered in the simulations. (author)

  6. A unified approach for radiative losses and backscattering in optical waveguides

    International Nuclear Information System (INIS)

    Melati, D; Morichetti, F; Melloni, A

    2014-01-01

    Sidewall roughness in optical waveguides represents a severe impairment for the proper functionality of photonic integrated circuits. The interaction between the propagating mode and the roughness is responsible for both radiative losses and distributed backscattering. In this paper, a unified vision on these extrinsic loss phenomena is discussed, highlighting the fundamental role played by the sensitivity of the effective index n eff of the optical mode to waveguide width variations. The n w model presented applies to both 2D slab waveguides and 3D laterally confined waveguides and is in very good agreement with existing models that individually describe radiative loss or backscattering only. Experimental results are presented, demonstrating the validity of the n w model for arbitrary waveguide geometries and technologies. This approach enables an accurate description of realistic optical waveguides and provides simple design rules for optimization of the waveguide geometry in order to reduce the propagation losses generated by sidewall roughness. (paper)

  7. Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide

    Science.gov (United States)

    Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Jeong Kim, Un; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

    2015-07-01

    We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a “plasmonic via” in plasmonic nanocircuits.

  8. Babinet-Inverted Optical Yagi-Uda Antenna for Unidirectional Radiation to Free Space

    Science.gov (United States)

    Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Choe, Jong-Ho; Lee, Jongcheon; Lee, Jaesoong; Jeong, Heejeong; Kim, Un Jeong; Park, Yeonsang; Song, In Yong; Park, Q.-Han; Hwang, Sung Woo; Kim, Kinam; Lee, Chang-Won

    2014-06-01

    Plasmonic nanoantennas are key elements in nanophotonics capable of directing radiation or enhancing the transition rate of a quantum emitter. Slot-type magnetic-dipole nanoantennas, which are complementary structures of typical electric-dipole-type antennas, have received little attention, leaving their antenna properties largely unexplored. Here we present a novel magnetic-dipole-fed multi-slot optical Yagi-Uda antenna. By engineering the relative phase of the interacting surface plasmon polaritons between the slot elements, we demonstrate that the optical antenna exhibits highly unidirectional radiation to free space. The unique features of the slot-based magnetic nanoantenna provide a new possibility of achieving integrated features such as energy transfer from one waveguide to another by working as a future optical via.

  9. Distribution measurement of radiation intensity with optical fiber at narrow space

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Chizuo [Nagoya Univ. (Japan). School of Engineering

    1998-07-01

    Recently, in the field or radiation measurement, optical fiber and scintillation fiber are also begun to use. In order to investigate a new application method of the optical fiber to radiation measurement, a lithium compound for neutron converter and a ZnS(Ag) scintillator are kneaded with epoxy type adhesives, and much few weight of them is coated at an end of optical fiber with 1 to 2 mm in diameter, which is further overcoated with black paint or an aluminum cap for its shielding light to produce a thermal neutron detector. The thermal neutron detector is found to be measurable to neutron flux distribution very rapidly and in high position resolution by moving with computer automatically. This method can be measured selctively aimed radiation such as thermal neutron, rapid neutron, {gamma}-ray, and so forth by means of changing the neutron converter. And, the developed fiber method could be widely used for measurement of neutron and {gamma}-ray intensity distribution at fine interval in the nuclear radiation facilities such as neighbors of accelerator facilities, medical radiation facilities. (G.K.)

  10. Optical solar energy adaptations and radiative temperature control of green leaves and tree barks

    Energy Technology Data Exchange (ETDEWEB)

    Henrion, Wolfgang; Tributsch, Helmut [Department of Si-Photovoltaik and Solare Energetik, Hahn-Meitner-Institut Berlin, 14109 Berlin (Germany)

    2009-01-15

    Trees have adapted to keep leaves and barks cool in sunshine and can serve as interesting bionic model systems for radiative cooling. Silicon solar cells, on the other hand, loose up to one third of their energy efficiency due to heating in intensive sunshine. It is shown that green leaves minimize absorption of useful radiation and allow efficient infrared thermal emission. Since elevated temperatures are detrimental for tensile water flow in the Xylem tissue below barks, the optical properties of barks should also have evolved so as to avoid excessive heating. This was tested by performing optical studies with tree bark samples from representative trees. It was found that tree barks have optimized their reflection of incoming sunlight between 0.7 and 2 {mu}m. This is approximately the optical window in which solar light is transmitted and reflected by green vegetation. Simultaneously, the tree bark is highly absorbing and thus radiation emitting between 6 and 10 {mu}m. These two properties, mainly provided by tannins, create optimal conditions for radiative temperature control. In addition, tannins seem to have adopted a function as mediators for excitation energy towards photo-antioxidative activity for control of radiation damage. The results obtained are used to discuss challenges for future solar cell optimization. (author)

  11. Variation of the optical energy gap with {gamma}-radiation and thickness in Bi-thin films

    Energy Technology Data Exchange (ETDEWEB)

    Al-Houty, L.; Kassem, M.E.; Abdel Kader, H.I. [Qatar Univ., Doha (Qatar). Dept. of Physics

    1995-02-01

    The effect of {gamma}-radiation and thickness on the optical energy gap of Bi-thin films has been investigated by measuring their optical absorbance. The measurements were carried out on thermally evaporated films having thicknesses in the range 5-20 nm. Different {gamma}-radiation doses were used ranging from 0-300 Mrad. The optical energy gap as well as the absorption coefficient were found to be {gamma}-dose dependent. (author).

  12. Variation of the optical energy gap with γ-radiation and thickness in Bi-thin films

    International Nuclear Information System (INIS)

    Al-Houty, L.; Kassem, M.E.; Abdel Kader, H.I.

    1995-01-01

    The effect of γ-radiation and thickness on the optical energy gap of Bi-thin films has been investigated by measuring their optical absorbance. The measurements were carried out on thermally evaporated films having thicknesses in the range 5-20 nm. Different γ-radiation doses were used ranging from 0-300 Mrad. The optical energy gap as well as the absorption coefficient were found to be γ-dose dependent. (author)

  13. Effect of the geometrical parameters of an optical integrator on the unformity of the radiation flux distribution

    International Nuclear Information System (INIS)

    Vishnyakova, T.P.; Klychev, Sh.I.

    1992-01-01

    The use of optical mixers in the optical irradiators of simulators of direct and concentrated solar radiation has been proposed. In this paper, the parameters of an optical mixer are calculated geometrically, and the effect of the parameters of the optical mixer on the unformity of the irradiance distribution η of the radiation flux on the detector is investigated. These investigations show that the light distribution from an optical mixer is close to the characteristics of an ideal uniform emitter within the region from 0 to the limit of α. 5 refs., 4 figs

  14. Spatial resolution in optical transition radiation (OTR) beam diagnostics

    International Nuclear Information System (INIS)

    Castellano, M.; Verzilov, V. A.

    1998-06-01

    An evaluation of the OTR single particle image dimension is obtained using diffraction theory based on a realistic description of the radiation source. This approach allows the analysis of the effect of the finite size of the emitting screen and of the imaging system. The role of practical experimental conditions in treating the intensity tail problem is estimated. It is shown that by exploiting the polarization properties of OTR, a considerable enhancement in the spatial resolution can be achieved, which becomes very similar to that of a standard point source

  15. Electrical Versus Optical: Comparing Methods for Detecting Terahertz Radiation Using Neon Lamps

    Science.gov (United States)

    Slocombe, L. L.; Lewis, R. A.

    2018-05-01

    Terahertz radiation impinging on a lit neon tube causes additional ionization of the encapsulated gas. As a result, the electrical current flowing between the electrodes increases and the glow discharge in the tube brightens. These dual phenomena suggest two distinct modes of terahertz sensing. The electrical mode simply involves measuring the electrical current. The optical mode involves monitoring the brightness of the weakly ionized plasma glow discharge. Here, we directly compare the two detection modes under identical experimental conditions. We measure 0.1-THz radiation modulated at frequencies in the range 0.1-10 kHz, for lamp currents in the range 1-10 mA. We find that electrical detection provides a superior signal-to-noise ratio while optical detection has a faster response. Either method serves as the basis of a compact, robust, and inexpensive room-temperature detector of terahertz radiation.

  16. Fibre optics cabling design for LHC detectors upgrade using variable radiation induced attenuation model

    CERN Document Server

    Shoaie, Mohammad Amin; Machado, Simao; Ricci, Daniel

    2018-01-01

    Foreseen upgrades over the next decades enable LHC to operate at a higher luminosity (HL-LHC). Accordingly, the optical links designed to transmit particle collision data need to be hardened against increased radiation level, allowing for a reliable communication. In this paper we study the fibre cabling design of a link between the transceiver optical front-end and the data control room. The radiation penalty calculation takes temperature drop down to ‒30°C into account. The proposed solution concatenates radiation-resistance and conventional fibres using multi-fibre interconnections. The end-to-end link loss during HL-LHC lifetime is estimated strictly less than 3.5 dB complying with predefined margin.

  17. Transient radiation effects in D.O.I. optical materials: Schott filter glass

    International Nuclear Information System (INIS)

    Simmons-Potter, K.

    1998-07-01

    Department of Energy and Defense Programs systems are becoming increasingly reliant on the use of optical technologies that must perform under a range of ionizing radiation environments. In particular, the radiation response of materials under consideration for applications in direct optical initiation (D.O.I.) schemes must be well characterized. In this report, transient radiation effects observed in Schott filter glass S-7010 are characterized. Under gamma exposure with 2 MeV photons in a 20--30 nsec pulse, the authors observe strong initial induced fluorescence in the red region of the spectrum followed by significant induced absorption over the same spectral region. Peak induced absorption coefficients of 0.113 cm -1 and 0.088 cm -1 were calculated at 800 nm and 660 nm respectively

  18. Radiation damage studies on the optical and mechanical properties of plastic scintillators

    International Nuclear Information System (INIS)

    Mizue Hamada, Margarida; Roberto Rela, Paulo; Eduardo da Costa, Fabio; Henrique de Mesquita, Carlos

    1999-01-01

    This paper describes the radiation damage studies on a large volume plastic scintillator based in polystyrene doped with PPO and POPOP. The consequences on their mechanical and scintillation properties were evaluated before and after irradiation with different dose rates of 60 Co gamma radiation, in several doses. The optical results show a significant difference in the radiation susceptibility, when the plastic scintillator is irradiated at low rate (0.1 kGy/h) with that irradiated at high dose rate (85 kGy/h). The losses in the optical and mechanical properties increase as the irradiation dose is increased. The damage evaluated by the transmittance, emission intensity, pulse height and tensile strength was normalized as a damage fraction and fitted by a bi-exponential function. It was observed that the damage for irradiation is not permanent and it obeys a bi-exponential function

  19. Transient radiation effects in D.O.I. optical materials: KD*P

    International Nuclear Information System (INIS)

    Simmons-Potter, K.

    1998-07-01

    Department of Energy and Defense Programs systems are becoming increasingly reliant on the use of optical technologies that must perform under a range of ionizing radiation environments. In particular, the radiation response of materials under consideration for applications in direct optical initiation (D.O.I.) schemes must be well characterized. In this report, transient radiation effects observed in a KD*P crystal are characterized. Under gamma exposure with 2 MeV photons in a 20--30 nsec pulse, the authors observe induced absorption at 1.06 microm that causes a peak decrease in overall sample transmittance of only 10%. This induced loss is seen to recover fully within the first 30 microsec

  20. Revisiting Bragg's X-ray microscope: Scatter based optical transient grating detection of pulsed ionising radiation

    International Nuclear Information System (INIS)

    Fullagar, Wilfred K.; Paganin, David M.; Hall, Chris J.

    2011-01-01

    Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. -- Research highlights: → It is timely that the concept of Bragg's X-ray microscope be revisited. → Transient gratings can be used for X-ray all-optical information processing. → Applications to optical real-time X-ray phase-retrieval are considered.

  1. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    Energy Technology Data Exchange (ETDEWEB)

    Debus, Alexander

    2012-09-06

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  2. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    International Nuclear Information System (INIS)

    Debus, Alexander

    2012-01-01

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  3. Modeling the behavior of optical elements in radiation environments

    International Nuclear Information System (INIS)

    Barlow, T.A.; Rhoades, C.E. Jr.; Merker, M.; Triplett, J.R.

    1986-01-01

    Calculation of heating caused by the deposition of x-rays in thin film optical elements is complicated because the mean free path of photo and autoionization electrons is comparable to the thin film thickness and thus the electron deposition cannot be considered local. This paper describes the modeling in a 1-D code of: (a) x-ray deposition and transport; (b) electron production, deposition and transport; and (c) thermal conduction and transport. X-ray transport is handled by multigroup discrete ordinates, electron transport is done by the method of characteristics, applied to the two term spherical harmonics expansion approximation (P1) to the Spencer-Lewis transport equation, and thermal transport is computed by a simple Richardson extrapolation of a backward Euler solution to the heat conduction equations. Results of a few test cases are presented. 8 refs., 26 figs., 2 tabs

  4. Optical measurement of thermal deformation of multilayer optics under synchrotron radiation

    International Nuclear Information System (INIS)

    Revesz, P.; Kazimirov, A.; Bazarov, I.

    2007-01-01

    An in situ optical technique to visualize surface distortions of the first monochromator crystal under synchrotron beam heat loading has been developed and applied to measure surface profiles of multilayer optics under white wiggler beam at the CHESS A2 beamline. Two identical multilayer structures deposited on Si and SiC substrates have been tested. Comparison of the reconstructed 3D heatbump profiles showed the surface distortions of the multilayer on SiC a factor of two smaller than the same multilayer on a Si substrate

  5. Optical measurement of thermal deformation of multilayer optics under synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Revesz, P. [Cornell University, CHESS, Ithaca, NY 14850 (United States)], E-mail: pr20@cornell.edu; Kazimirov, A.; Bazarov, I. [Cornell University, CHESS, Ithaca, NY 14850 (United States)

    2007-11-11

    An in situ optical technique to visualize surface distortions of the first monochromator crystal under synchrotron beam heat loading has been developed and applied to measure surface profiles of multilayer optics under white wiggler beam at the CHESS A2 beamline. Two identical multilayer structures deposited on Si and SiC substrates have been tested. Comparison of the reconstructed 3D heatbump profiles showed the surface distortions of the multilayer on SiC a factor of two smaller than the same multilayer on a Si substrate.

  6. Determining optical and radiation characteristics of cathode ray tubes' glass to be reused as radiation shielding glass

    Science.gov (United States)

    Zughbi, A.; Kharita, M. H.; Shehada, A. M.

    2017-07-01

    A new method of recycling glass of Cathode Ray Tubes (CRTs) has been presented in this paper. The glass from CRTs suggested being used as raw materials for the production of radiation shielding glass. Cathode ray tubes glass contains considerable amounts of environmentally hazardous toxic wastes, namely heavy metal oxides such as lead oxide (PbO). This method makes CRTs glass a favorable choice to be used as raw material for Radiation Shielding Glass and concrete. The heavy metal oxides increase its density, which make this type of glass nearly equivalent to commercially available shielding glass. CRTs glass have been characterized to determine heavy oxides content, density, refractive index, and radiation shielding properties for different Gamma-Ray energies. Empirical methods have been used by using the Gamma-Ray source cobalt-60 and computational method by using the code XCOM. Measured and calculated values were in a good compatibility. The effects of irradiation by gamma rays of cobalt-60 on the optical transparency for each part of the CRTs glass have been studied. The Results had shown that some parts of CRTs glass have more resistant to Gamma radiation than others. The study had shown that the glass of cathode ray tubes could be recycled to be used as radiation shielding glass. This proposed use of CRT glass is only limited to the available quantity of CRT world-wide.

  7. Cerenkov light spectrum in an optical fiber exposed to a photon or electron radiation therapy beam

    International Nuclear Information System (INIS)

    Lambert, Jamil; Yin Yongbai; McKenzie, David R.; Law, Sue; Suchowerska, Natalka

    2009-01-01

    A Cerenkov signal is generated when energetic charged particles enter the core of an optical fiber. The Cerenkov intensity can be large enough to interfere with signals transmitted through the fiber. We determine the spectrum of the Cerenkov background signal generated in a poly(methyl methacrylate) optical fiber exposed to photon and electron therapeutic beams from a linear accelerator. This spectral measurement is relevant to discrimination of the signal from the background, as in scintillation dosimetry using optical fiber readouts. We find that the spectrum is approximated by the theoretical curve after correction for the wavelength dependent attenuation of the fiber. The spectrum does not depend significantly on the angle between the radiation beam and the axis of the fiber optic but is dependent on the depth in water at which the fiber is exposed to the beam.

  8. Extending the possibilities in phase space analysis of synchrotron radiation x-ray optics.

    Science.gov (United States)

    Ferrero, Claudio; Smilgies, Detlef-Matthias; Riekel, Christian; Gatta, Gilles; Daly, Peter

    2008-08-01

    A simple analytical approach to phase space analysis of the performance of x-ray optical setups (beamlines) combining several elements in position-angle-wavelength space is presented. The mathematical description of a large class of optical elements commonly used on synchrotron beamlines has been reviewed and extended with respect to the existing literature and is reported in a revised form. Novel features are introduced, in particular, the possibility to account for imperfections on mirror surfaces and to incorporate nanofocusing devices like refractive lenses in advanced beamline setups using the same analytical framework. Phase space analysis results of the simulation of an undulator beamline with focusing optics at the European Synchrotron Radiation Facility compare favorably with results obtained by geometric ray-tracing methods and, more importantly, with experimental measurements. This approach has been implemented into a simple and easy-to-use program toolkit for optical calculations based on the Mathematica software package.

  9. Statistical optics approach to the design of beamlines for synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, G.; Saldin, E.; Schneidmiller, E.; Yurkov, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-04-15

    In this paper we analyze the image formation problem for undulator radiation through an optical system, accounting for the influence of the electron beam emittance. On the one hand, image formation with Synchrotron Radiation is governed by the laws of Statistical Optics. On the other hand, the widely used Gaussian-Shell model cannot be applied to describe the coherence properties of X-ray beams from third generation Synchrotron Radiation sources. As a result, a more rigorous analysis of coherence properties is required. We propose a technique to explicitly calculate the cross-spectral density of an undulator source, that we subsequently propagate through an optical imaging system. At first we focus on the case of an ideal lens with a non-limiting pupil aperture. Our theory, which makes consistent use of dimensionless analysis, also allows treatment and physical understanding of many asymptotes of the parameter space, together with their applicability region. Particular emphasis is given to the asymptotic situation when the horizontal emittance is much larger than the radiation wavelength, which is relevant for third generation Synchrotron Radiation sources. First principle calculations of undulator radiation characteristics (i.e. ten-dimensional integrals) are then reduced to one-dimensional convolutions of analytical functions with universal functions specific for undulator radiation sources. We also consider the imaging problem for a non-ideal lens in presence of abberations and a limiting pupil aperture, which increases the dimension of the convolution from one to three. In particular we give emphasis to cases when the intensity at the observation plane can be presented as a convolution of an impulse response function and the intensity from an ideal lens. Our results may be used in practical cases as well as in benchmarks for numerical methods.

  10. In situ visualization of thermal distortions of synchrotron radiation optics

    International Nuclear Information System (INIS)

    Revesz, P.; Kazimirov, A.; Bazarov, I.

    2007-01-01

    We have developed a new in situ method to measure heating-induced distortions of the surface of the first monochromator crystal exposed to high-power white synchrotron radiation beam. The method is based on recording the image of a stationary grid of dots captured by a CCD camera as reflected from the surface of a crystal with and without a heat load. The three-dimensional surface profile (heat bump) is then reconstructed from the distortions of the original pattern. In experiments performed at the CHESS A2 wiggler beam line we measured the heat bumps with the heights of up to 600 nm produced by a wiggler beam with total power in the range of 15-60 W incident on the (1 1 1) Si crystal at various angles between 3 deg. and 15 deg

  11. Development of radiation-hard optical links for the CMS tracker at CERN

    International Nuclear Information System (INIS)

    Vasey, F.; Arbet-Engels, V.; Cervelli, G.; Gill, K.; Grabit, R.; Mommaert, C.; Stefanini, G.

    1998-01-01

    A radiation-hard optical link is under development for readout and control of the tracking detector in the future CMS experiment at the CERN Large Hadron Collider. The authors present the optical system architecture based on edge-emitting InGaAsP laser-diode transmitters operating at a wavelength of 1.3 microm, single mode fiber ribbons, multi-way connectors and InGaAsP in photodiode receivers. They report on radiation hardness tests of lasers, photodiodes, fibers and connectors. Increases of laser threshold and pin leakage currents with hadron fluence have been observed together with decreases in laser slope-efficiency and photodiode responsivity. Short lengths of single-mode optical fiber and multi-way connectors have been found to be little affected by radiation damage. They analyze the analog and digital performance of prototype optical links transmitting data generated at a 40 MSample/s rate. Distortion, settling time, bandwidth, noise, dynamic range and bit-error-rate results are discussed

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

    International Nuclear Information System (INIS)

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

    1999-01-01

    Z-pinches created using the Z accelerator generate approximately220 TW, 1.7 MJ radiation pulses that heat large (approximately10 cm 3 ) hohlraums to 100-150 eV temperatures for times of order 10 nsec. We are performing experiments exploiting this intense radiation to drive shock waves for equation of state studies. The shock pressures are typically 1-10 Mbar with 10 nsec duration in 6-mm-diameter samples. In this paper we demonstrate the ability to perform optical spectroscopy measurements on shocked samples located in close proximity to the z-pinch. These experiments are particularly well suited to optical spectroscopy measurements because of the relatively large sample size and long duration. The optical emission is collected using fiber optics and recorded with a streaked spectrograph. Other diagnostics include VISAR and active shock breakout measurements of the shocked sample and a suite of diagnostics that characterize the radiation drive. Our near term goal is to use the spectral emission to obtain the temperature of the shocked material. Longer term objectives include the examination of deviations of the spectrum from blackbody, line emission from lower density regions, determination of kinetic processes in molecular systems, evaluation of phase transitions such as the onset of metalization in transparent materials, and characterization of the plasma formed when the shock exits the rear surface. An initial set of data illustrating both the potential and the challenge of these measurements is described

  13. Investigation of thermo-optical characteristics of the interaction processes of laser radiation with silver nanoparticles

    International Nuclear Information System (INIS)

    Pustovalov, V K; Astafyeva, L G

    2013-01-01

    Metallic nanoparticles have been actively investigated in recent years by different optical and laser methods with the purpose of their applications in optoelectronics and photonics, chemistry, laser nanobiomedicine, optical diagnostics, and other fields. A major role among metallic nanoparticles is played by nanoparticles from the noble metals (silver, gold, etc). These particles have unique plasmonic properties (resonances in the range of wavelength 400–540 nm), which can be used for the absorption, scattering and transformation of laser energy. Analysis of the thermo-optical characteristics of the interaction processes of laser radiation with silver nanoparticles is carried out, taking into account absorption, scattering and extinction of laser radiation by nanoparticles, as well as the thermo-optical and other properties of nanoparticles. Estimations are made of the influence of these nanoparticle properties on the possible results of laser radiation interaction with silver nanoparticles, including heating, heat exchange, possible melting and evaporation, and processes in the ambient media. These results can be used in laser processing of silver nanoparticles and their applications in laser nanomedicine. (paper)

  14. Mounting and Alignment of Full-Shell Replicated X-Ray Optics

    Science.gov (United States)

    Gubarev, Mikhail; Arnold, William; Kester, Thomas; Ramsey, Brian; Smithers, Martin

    2007-01-01

    We are developing grazing-incidence x-ray optics for astronomy. The optics are full-cylinder mirror shells fabricated using electroformed-nickel replication off super-polished mandrels. For space-based applications where weight is at a premium, very-thin-walled, light-weight mirrors are required. Such shells have been fabricated at MSFC with greater than 15 arcsec resolution. The challenge, however, is to preserve this resolution during mounting and assembly. We present here a status report on a mounting and alignment system currently under development at Marshall Space Flight Center to meet this challenge.

  15. Defect testing of large aperture optics based on high resolution CCD camera

    International Nuclear Information System (INIS)

    Cheng Xiaofeng; Xu Xu; Zhang Lin; He Qun; Yuan Xiaodong; Jiang Xiaodong; Zheng Wanguo

    2009-01-01

    A fast testing method on inspecting defects of large aperture optics was introduced. With uniform illumination by LED source at grazing incidence, the image of defects on the surface of and inside the large aperture optics could be enlarged due to scattering. The images of defects were got by high resolution CCD camera and microscope, and the approximate mathematical relation between viewing dimension and real dimension of defects was simulated. Thus the approximate real dimension and location of all defects could be calculated through the high resolution pictures. (authors)

  16. Radiation-resistant optical sensors and cameras; Strahlungsresistente optische Sensoren und Kameras

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, G. [Imaging and Sensing Technology, Bonn (Germany)

    2008-02-15

    Introducing video technology, i.e. 'TV', specifically in the nuclear field was considered at an early stage. Possibilities to view spaces in nuclear facilities by means of radiation-resistant optical sensors or cameras are presented. These systems are to enable operators to monitor and control visually the processes occurring within such spaces. Camera systems are used, e.g., for remote surveillance of critical components in nuclear power plants and nuclear facilities, and thus contribute also to plant safety. A different application of optical systems resistant to radiation is in the visual inspection of, e.g., reactor pressure vessels and in tracing small parts inside a reactor. Camera systems are also employed in remote disassembly of radioactively contaminated old plants. Unfortunately, the niche market of radiation-resistant camera systems hardly gives rise to the expectation of research funds becoming available for the development of new radiation-resistant optical systems for picture taking and viewing. Current efforts are devoted mainly to improvements of image evaluation and image quality. Other items on the agendas of manufacturers are the reduction in camera size, which is limited by the size of picture tubes, and the increased use of commercial CCD cameras together with adequate shieldings or improved lenses. Consideration is also being given to the use of periphery equipment and to data transmission by LAN, WAN, or Internet links to remote locations. (orig.)

  17. Investigation of radiative effects of the optically thick dust layer over the Indian tropical region

    Directory of Open Access Journals (Sweden)

    S. K. Das

    2013-04-01

    Full Text Available Optical and physical properties of aerosols derived from multi-satellite observations (MODIS-Aqua, OMI-Aura, MISR-Terra, CALIOP-CALIPSO have been used to estimate radiative effects of the dust layer over southern India. The vertical distribution of aerosol radiative forcing and heating rates are calculated with 100 m resolution in the lower atmosphere, using temperature and relative humidity data from balloon-borne radiosonde observations. The present study investigates the optically thick dust layer of optical thickness 0.18 ± 0.06 at an altitude of 2.5 ± 0.7 km over Gadanki, transported from the Thar Desert, producing radiative forcing and heating rate of 11.5 ± 3.3 W m−2 and 0.6 ± 0.26 K day−1, respectively, with a forcing efficiency of 43 W m−2 and an effective heating rate of 4 K day−1 per unit dust optical depth. Presence of the dust layer increases radiative forcing by 60% and heating rate by 60 times at that altitude compared to non-dusty cloud-free days. Calculation shows that the radiative effects of the dust layer strongly depend on the boundary layer aerosol type and mass loading. An increase of 25% of heating by the dust layer is found over relatively cleaner regions than urban regions in southern India and further 15% of heating increases over the marine region. Such heating differences in free troposphere may have significant consequences in the atmospheric circulation and hydrological cycle over the tropical Indian region.

  18. Noninvasive diffuse optical monitoring of head and neck tumor blood flow and oxygenation during radiation delivery

    Science.gov (United States)

    Dong, Lixin; Kudrimoti, Mahesh; Cheng, Ran; Shang, Yu; Johnson, Ellis L.; Stevens, Scott D.; Shelton, Brent J.; Yu, Guoqiang

    2012-01-01

    This study explored using a novel diffuse correlation spectroscopy (DCS) flow-oximeter to noninvasively monitor blood flow and oxygenation changes in head and neck tumors during radiation delivery. A fiber-optic probe connected to the DCS flow-oximeter was placed on the surface of the radiologically/clinically involved cervical lymph node. The DCS flow-oximeter in the treatment room was remotely operated by a computer in the control room. From the early measurements, abnormal signals were observed when the optical device was placed in close proximity to the radiation beams. Through phantom tests, the artifacts were shown to be caused by scattered x rays and consequentially avoided by moving the optical device away from the x-ray beams. Eleven patients with head and neck tumors were continually measured once a week over a treatment period of seven weeks, although there were some missing data due to the patient related events. Large inter-patient variations in tumor hemodynamic responses were observed during radiation delivery. A significant increase in tumor blood flow was observed at the first week of treatment, which may be a physiologic response to hypoxia created by radiation oxygen consumption. Only small and insignificant changes were found in tumor blood oxygenation, suggesting that oxygen utilizations in tumors during the short period of fractional radiation deliveries were either minimal or balanced by other effects such as blood flow regulation. Further investigations in a large patient population are needed to correlate the individual hemodynamic responses with the clinical outcomes for determining the prognostic value of optical measurements. PMID:22312579

  19. Observation and resonant x-ray optical interpretation of multi-atom resonant photoemission effects in O 1s emission from NiO

    International Nuclear Information System (INIS)

    Mannella, N.; Yang, S.-H.; Mun, B.S.; Garcia de Abajo, F.J.; Kay, A.W.; Sell, B.C.; Watanabe, M.; Ohldag, H.; Arenholz, E.; Young, A.T.; Hussain, Z.; Van Hove, M.A.; Fadley, C.S.

    2006-01-01

    We present experimental and theoretical results for the variation of the O 1s intensity from a NiO(001) surface as the excitation energy is varied through the Ni 2p1/2,3/2 absorption resonances, and as the incidence angle of the radiation is varied from grazing to larger values. For grazing incidence, a strong multi-atom resonant photoemission(MARPE) effect is seen on the O 1s intensity as the Ni 2p resonances are crossed, but its magnitude decreases rapidly as the incidence angle is increased. Resonant x-ray optical (RXRO) calculations are found to predict these effects very well, although the experimental effects are found to decrease at higher incidence angles faster than those in theory. The potential influence of photoelectron diffraction effects on such measurements are also considered, including experimental data with azimuthal-angle variation and corresponding multiple-scattering-diffraction calculations, but we conclude that they do not vary beyond what is expected on the basis of the change in photoelectron kinetic energy. Varying from linear polarization to circular polarization is found to enhance these effects in NiO considerably, although the reasons are not clear. We also discuss the relationship of these measurements to other related interatomic resonance experiments and theoretical developments, and make some suggestions for future studies in this area

  20. Radiation-induced bilateral optic neuropathy in cancer of the nasopharynx. Case failure analysis and a review of the literature

    International Nuclear Information System (INIS)

    Wijers, O.B.; Levendag, P.C.; Klesman-Bradley, J.; Woudstra, E.; Luyten, G.P.M.; Bakker, B.A.; Freling, N.J.M.

    1999-01-01

    Case Report: A case history of unanticipated radiation-induced bilateral optic neuropathy, 18 months after induction chemotherapy and radiation therapy for a locally advanced nasopharyngeal carcinoma, is presented. Retrospective reanalysis of the radiation therapy technique, with emphasis on the doses received by the optic pathway structures, was performed. These re-calculations revealed unexpectedly high doses in the range 79 and 82 Gy (cumulative external and brachytherapy dose) at the level of the optic nerves, which explained the observed radiation injury. Conclusion: Routine implementation of computed tomography for 3D dose planning purposes is therefore advocated. Review of the current literature confirms the importance of 3D dose planning in avoiding this complication and highlights the role of MRI in establishing the diagnosis of radiation-induced optic neuropathy. (orig.) [de

  1. Materials for Concentrator Photovoltaic Systems: Optical Properties and Solar Radiation Durability

    Science.gov (United States)

    French, R. H.; Rodríguez-Parada, J. M.; Yang, M. K.; Lemon, M. F.; Romano, E. C.; Boydell, P.

    2010-10-01

    Concentrator photovoltaic (CPV) systems are designed to operate over a wide range of solar concentrations, from low concentrations of ˜1 to 12 Suns to medium concentrations in the range from 12 to 200 Suns, to high concentration CPV systems going up to 2000 Suns. Many transparent optical materials are used for a wide variety of functions ranging from refractive and reflective optics to homogenizers, encapsulants and even thermal management. The classes of materials used also span a wide spectrum from hydrocarbon polymers (HCP) and fluoropolymers (FP) to silicon containing polymers and polyimides (PI). The optical properties of these materials are essential to the optical behavior of the system. At the same time radiation durability of these materials under the extremely wide range of solar concentrations is a critical performance requirement for the required lifetime of a CPV system. As part of our research on materials for CPV we are evaluating the optical properties and solar radiation durability of various polymeric materials to define the optimum material combinations for various CPV systems.

  2. Solar radiative heating of fiber-optic cables used to monitor temperatures in water

    Science.gov (United States)

    Neilson, Bethany T.; Hatch, Christine E.; Ban, Heng; Tyler, Scott W.

    2010-08-01

    In recent years, applications of distributed temperature sensing (DTS) have increased in number and diversity. Because fiber-optic cables used for DTS are typically sheathed in dark UV-resistant materials, the question arises as to how shortwave solar radiation penetrating a water column influences the accuracy of absolute DTS-derived temperatures in aquatic applications. To quantify these effects, we completed a modeling effort that accounts for the effects of radiation and convection on a submersed cable to predict when solar heating may be important. Results indicate that for cables installed at shallow depths in clear, low-velocity water bodies, measurable heating of the cable is likely during peak solar radiation. However, at higher velocities, increased turbidity and/or greater depths, the effects of solar heating are immeasurable. A field study illustrated the effects of solar radiation by installing two types of fiber-optic cable at multiple water depths (from 0.05 to 0.8 m) in the center and along the sidewall of a trapezoidal canal. Thermistors were installed at similar depths and shielded from solar radiation to record absolute water temperatures. During peak radiation, thermistor data showed small temperature differences (˜0.003°C-0.04°C) between depths suggesting minor thermal stratification in the canal center. DTS data from cables at these same depths show differences of 0.01°C-0.17°C. The DTS differences cannot be explained by stratification alone and are likely evidence of additional heating from solar radiation. Sidewall thermistor strings also recorded stratification. However, corresponding DTS data suggested that bed conduction overwhelmed the effects of solar radiation.

  3. Sensitive Detection: Photoacoustics, Thermography, and Optical Radiation Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Diebold, Gerald J. [Brown Univ., Providence, RI (United States)

    2017-04-21

    Research during the granting period has been carried out in several areas concerned with sensitive detection. An infrared pyrometer based on the photoacoustic effect has been developed. The sensitivity of this instrument to temperature differentials has been shown to be 50 mK. An investigation of transients that accompany photoacoustic waves generated by pulsed lasers has been carried out. Experiments have shown the existence of the transients, and a theory based on rapid heat diffusion has been developed. The photoacoustic effect in one dimension is known to increase without bound (in the linear acoustics regime) when an optical beam moves in a fluid at the sound speed. A solution to the wave equation for pressure has been found that describes the photoacoustic effect in a cell where an infrared optical grating moves at the sound speed. It was shown that the amplification effect exists along with a cavity resonance that can be used to great advantage in trace gas detection. The theory of the photoacoustic effect in a structure where the acoustic properties periodically vary in a one-dimensional based has been formulated based on solutions to a Mathieu equation. It was found that it is possible to excite photoacoustic waves within the band gaps to produce large amplitude acoustic waves. The idea of self-oscillation in a photoacoustic cell using a continuous laser has been investigated. A theory has been completed showing that in a compressive wave, the absorption increases as a result of the density increase leading to further absorption and hence an increased amplitude photoacoustic effect with the result that in a resonator, self-oscillation can place. Experiments have been carried out where irradiation of a suspension of absorbing carbon particles with a high power laser has been shown to result in cavitation luminescence. That is, following generation of CO and H2 from the carbon particles through the carbon-steam reaction, an expanding gas bubble is

  4. Electro-Optical Sensing Apparatus and Method for Characterizing Free-Space Electromagnetic Radiation

    Science.gov (United States)

    Zhang, Xi-Cheng; Libelo, Louis Francis; Wu, Qi

    1999-09-14

    Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric field and a laser beam in an electro-optic crystal. In addition to a practical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field--optical beam interaction length, thereby making imaging applications practical.

  5. Development of optical thin film technology for lasers and synchrotron radiation

    International Nuclear Information System (INIS)

    Apparao, K.V.S.R.; Bagchi, T.C.; Sahoo, N.K.

    1985-01-01

    Dielectric multilayer optical thin film devices play an important role not only in the working of lasers but also in different front line research activities using high power lasers and high intensity synchrotron radiation sources. Facilities are set up recently in the Spectroscopy Division to develop the optical thin film design and fabrication technologies indigeneously. Using the facilities thin film devices for different laser applications working in the wavelength range from 300 nm to 1064 nm were developed. Different technical aspects involved in the technology development are briefly described. (author)

  6. On the structural-optical correlations in radiation-modified chalcogenide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kavetskyy, T; Tsmots, V [Solid State Microelectronics Laboratory, Drohobych Ivan Franko State Pedagogical University, 24 I. Franko Str., Drohobych, 82100 (Ukraine); Kaban, I; Hoyer, W [Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz (Germany); Shpotyuk, O, E-mail: kavetskyy@yahoo.com [Institute of Materials, Scientific Research Company ' Carat' , 202 Stryjska Str., Lviv, 79031 (Ukraine)

    2011-04-01

    In this work, we report our recent results on the gamma-irradiation-induced structural transformations in the Ge-Sb-S glasses as observed from the structural studies using high-energy synchrotron x-ray diffraction and extended x-ray absorption fine structure spectroscopy in comparison with the optical measurements using VIS/IR spectroscopy techniques. The structural-optical correlations in the radiation-induced effects are established. The structural changes upon irradiation are explained in the frames of the concept of coordination topological defects formation.

  7. On the structural-optical correlations in radiation-modified chalcogenide glasses

    International Nuclear Information System (INIS)

    Kavetskyy, T; Tsmots, V; Kaban, I; Hoyer, W; Shpotyuk, O

    2011-01-01

    In this work, we report our recent results on the gamma-irradiation-induced structural transformations in the Ge-Sb-S glasses as observed from the structural studies using high-energy synchrotron x-ray diffraction and extended x-ray absorption fine structure spectroscopy in comparison with the optical measurements using VIS/IR spectroscopy techniques. The structural-optical correlations in the radiation-induced effects are established. The structural changes upon irradiation are explained in the frames of the concept of coordination topological defects formation.

  8. A case of radiation optic neuropathy after irradiation for pituitary adenoma

    International Nuclear Information System (INIS)

    Ohta, Masahiro; Sasaki, Ushio; Shinohara, Nobuya; Takeda, Tetsuji; Chaki, Takanori; Nishigakiuchi, Keiji; Kusunoki, Katsusuke

    1992-01-01

    A 60-year-old woman with radiation optic neuropathy 21 months after irradiation is reported. The patient received a total dose of 50 Gy in 25 fractions for 39 days for pituitary adenoma. She presented with bitemporal hemianopsia and loss of recent memory. Gadolinium-enhanced T1-weighted imaging was very useful for detecting lesions in the optic nerves and chiasm to the hypothalamus including mamillary bodies. Two-month steroid therapy was effective in preventing the disease progression, although visual loss and loss of recent memory were not improved. (N.K.)

  9. A case of radiation optic neuropathy after irradiation for pituitary adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Masahiro; Sasaki, Ushio; Shinohara, Nobuya; Takeda, Tetsuji; Chaki, Takanori; Nishigakiuchi, Keiji; Kusunoki, Katsusuke (Ehime Prefectural Central Hospital, Matsuyama (Japan))

    1992-05-01

    A 60-year-old woman with radiation optic neuropathy 21 months after irradiation is reported. The patient received a total dose of 50 Gy in 25 fractions for 39 days for pituitary adenoma. She presented with bitemporal hemianopsia and loss of recent memory. Gadolinium-enhanced T1-weighted imaging was very useful for detecting lesions in the optic nerves and chiasm to the hypothalamus including mamillary bodies. Two-month steroid therapy was effective in preventing the disease progression, although visual loss and loss of recent memory were not improved. (N.K.).

  10. Program description of FIBRAM: a radiation attenuation model for optical fibers

    International Nuclear Information System (INIS)

    Ingram, W.J.

    1987-06-01

    The report describes a fiber optics system model and its computer implementation. This implementation can calculate the bit error ratio (BER) versus time for optical fibers that have been exposed to gamma radiation. The program is designed so that the user may arbitrarily change any or all of the system input variables and produce separate output calculations. The primary output of the program is a table of the BER as a function of time. This table may be stored on magnetic media and later incorporated into computer graphics programs

  11. Development of optical spectrum acquisition with spectrophotometer for characterization of optical radiation sources

    International Nuclear Information System (INIS)

    Solano Vargas, Alvaro

    2013-01-01

    An improved process of the data acquisition system is developed with Pasco 750 interface and Pasco OS-8539 spectrophotometer. The optical spectrum and color temperature of incandescent sources available are obtained from the Laboratorio de Fotonica y Tecnologia Laser Aplicada. The procedures developed in the project are recommended to collect data and analyze results. The purchase of a new Software and the interface of Pasco is recommended to have a better operation and update [es

  12. Radiation impact on the characteristics of optical glasses test results on a selected set of materials

    Science.gov (United States)

    Fruit, Michel; Gussarov, Andrei; Berghmans, Francis; Doyle, Dominic; Ulbrich, Gerd

    2017-11-01

    It is well known within the Space optics community that radiation may significantly affect transmittance of glasses. To overcome this drawback, glass manufacturers have developed Cerium doped counterparts of classical glasses. This doped glasses display much less transmittance sensitivity to radiation. Still, the impact of radiation on refractive index is less known and may affect indifferently classical or Cerium doped glasses. ESTEC has initialised an R&D program with the aim of establishing a comprehensive data base gathering radiation sensitivity data, called Dose coefficients, for all the glass optical parameters (transmittance / refractive index / compaction……). The first part of this study, to define the methodology for such a data base, is run by ASTRIUM SAS in co-operation with SCK CEN. This covers theoretical studies associated to testing of a selected set of classical and "radiation hardened" glasses. It is proposed here to present first the theoretical backgrounds of this study and then to give results which have been obtained so far.

  13. Optical radiation measurements II; Proceedings of the Meeting, Orlando, FL, Mar. 27, 28, 1989

    Science.gov (United States)

    Palmer, James M.

    1989-09-01

    The present conference discusses topics in the characterization of imaging radiometers, laboratory instrumentation, field and spacecraft instrumentation, and quantum and thermal standard detectors. Attention is given to UV radiometric imaging, dual-color radiometer imagery, a novel diode-array radiometer, a novel reference spectrophotometer, radiance calibration of spherical integrators, instrumentation for measurement of spectral goniometric reflectance, and a real-time IR background discrimination radiometer. Also discussed are a multichannel radiometer for atmosphere optical property measurements, the UV spectroradiometric output of a turbojet, characterizations of the Earth Radiation Budget Experiment scanning radiometers, total-radiation thermometry, future directions in Si photodiode self-calibration, and radiometric quality Ge photodiodes.

  14. Tuning characteristics of narrowband THz radiation generated via optical rectification in periodically poled lithium niobate.

    Science.gov (United States)

    Weiss, C; Torosyan, G; Meyn, J P; Wallenstein, R; Beigang, R; Avetisyan, Y

    2001-04-23

    The tuning properties of pulsed narrowband THz radiation generated via optical rectification in periodically poled lithium niobate have been investigated. Using a disk-shaped periodically poled crystal tuning was easily accomplished by rotating the crystal around its axis and observing the generated THz radiation in forward direction. In this way no beam deflection during tuning was observed. The total tuning range extended from 180 GHz up to 830 GHz and was limited by the poling period of 127 microm which determines the maximum THz frequency in forward direction.

  15. Space radiation effects in high performance fiber optic data links for satellite data management

    International Nuclear Information System (INIS)

    Marshall, P.W.; Dale, C.J.; LaBel, K.A.

    1996-01-01

    Fiber optic based technologies are relatively new to satellite applications, and are receiving considerable attention for planned applications in NASA, DOD, and commercial space sectors. The authors review various activities in recent years aimed at understanding and mitigating radiation related risk in deploying fiber based data handling systems on orbit. Before concluding that there are no critical barriers to designing survivable and reliable systems, the authors analyze several possible types of radiation effects. Particular attention is given to the subject of particle-induced bit errors in InGaAs p-i-n photodiodes, including a discussion of error mitigation and upset rate prediction methods

  16. Wave like signatures in aerosol optical depth and associated radiative impacts over the central Himalayan region

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, K. K.; Phanikumar, D. V.; Kumar, K.  Niranjan; Reddy, Kishore; Kotamarthi, V. R.; Newsom, Rob K.; Ouarda, Taha B. M. J.

    2015-10-01

    Doppler Lidar and Multi-Filter Rotating Shadowband Radiometer (MFRSR) observations are utilized to show wave like signatures in aerosol optical depth (AOD) during daytime boundary layer evolution over the Himalayan region. Fourier analysis depicted 60–80 min periods dominant during afternoon hours, implying that observed modulations could be plausible reason for the AOD forenoon–afternoon asymmetry which was previously reported. Inclusion of wave amplitude in diurnal variation of aerosol radiative forcing estimates showed ~40% additional warming in the atmosphere relative to mean AOD. The present observations emphasize the importance of wave induced variations in AOD and radiation budget over the site.

  17. System tests of radiation hard optical links for the ATLAS semiconductor tracker

    International Nuclear Information System (INIS)

    Charlton, D.G.; Dowell, J.D.; Homer, R.J.; Jovanovic, P.; Kenyon, I.R.; Mahout, G.; Shaylor, H.R.; Wilson, J.A.; Rudge, A.; Fopma, J.; Mandic, I.; Nickerson, R.B.; Shield, P.; Wastie, R.; Weidberg, A.R.; Eek, L.-O.; Go, A.; Lund-Jensen, B.; Pearce, M.; Soederqvist, J.; Morrissey, M.; White, D.J.

    2000-01-01

    A prototype optical data and Timing, Trigger and Control transmission system based on LEDs and PIN-diodes has been constructed. The system would be suitable in terms of radiation hardness and radiation length for use in the ATLAS SemiConductor Tracker. Bit error rate measurements were performed for the data links and for the links distributing the Timing, Trigger and Control data from the counting room to the front-end modules. The effects of cross-talk between the emitters and receivers were investigated. The advantages of using Vertical Cavity Surface Emitting Lasers (VCSELs) instead of LEDs are discussed

  18. Radiation distribution measurement using plastic scintillating optical fibers for survey of radioactive contamination in wide area

    International Nuclear Information System (INIS)

    Ito, Chikara; Ito, Keisuke; Ishikawa, Takashi; Yoshida, Akihiro; Sanada, Yukihisa; Torii, Tatsuo; Nohtomi, Akihiro; Wakabayashi, Genichiro; Miyazaki, Nobuyuki

    2013-01-01

    It is important to examine distribution of environmental contamination due to the accident of Fukushima Daiichi Nuclear Power Station and to confirm the effect of decontamination works. We have applied radiation distribution measurement using plastic scintillating optical fibers (PSFs) in the survey of contamination in wide area including residential, farmland, forests, etc. In the measurements system, two scintillation lights that emitted at an incidence of a radiation transmit to photomultiplier tubes at the both end of PSFs. The position where scintillation light emitted is obtained from the detection time difference of each photomultiplier tube. The distribution of light emission quantity indicates the distribution of radiation incident in a PSF which is corresponds to the distribution of dose-rate. The radiation detection system using the PSFs has been applied to the radiation distribution measurement on grounds, trees, etc. The results show a good agreement with point data measured by survey meters using sodium iodide scintillators. As the PSFs which have water resistance, they have been successfully applied to the radiation distribution measurement in the river. We have also succeeded in measuring two-dimensional distribution of radiation by measuring the count rate while moving to the fiber at a constant speed. (author)

  19. Changes of Radial Diffusivity and Fractional Anisotopy in the Optic Nerve and Optic Radiation of Glaucoma Patients

    Directory of Open Access Journals (Sweden)

    Tobias Engelhorn

    2012-01-01

    Full Text Available Purpose of this study was to evaluate with diffusion-tensor imaging (DTI changes of radial diffusivity (RD and fractional anisotropy (FA in the optic nerve (ON and optic radiation (OR in glaucoma and to determine whether changes in RD and FA correlate with disease severity. Therefore, glaucoma patients and controls were examined using 3T. Regions of interest were positioned on RD and FA maps, and mean values were calculated for ON and OR and correlated with optic nerve atrophy and reduced spatial-temporal contrast sensitivity (STCS of the retina. We found, that RD in glaucoma patients was significantly higher in the ON (0.74 ± 0.21 versus 0.58 ± 0.17⋅10−3 mm2 s−1; P0.77. In conclusion, DTI at 3 Tesla allows robust RD and FA measurements in the ON and OR. Hereby, the extent of RD increase and FA decrease in glaucoma correlate with established ophthalmological examinations.

  20. Real-time synchrotoron radiation X-ray diffraction and abnormal temperature dependence of photoluminescence from erbium silicates on SiO2/Si substrates

    Directory of Open Access Journals (Sweden)

    H. Omi

    2012-03-01

    Full Text Available The erbium silicate formation processes during annealing in Ar gas were monitored by synchrotron radiation grazing incidence X-ray diffraction (GIXD in real time and the optical properties of the silicates were investigated by photoluminescence measurements in spectral and time-resolved domains. The GIXD measurements show that erbium silicates and erbium oxide are formed by interface reactions between silicon oxide and erbium oxides deposited on silicon oxide by reactive sputtering in Ar gas and O2/Ar mixture gas ambiences. The erbium silicates are formed above 1060 °C in Ar gas ambience and above 1010 °C in O2/Ar gas ambience, and erbium silicides are dominantly formed above 1250 °C. The I15/2-I13/2 Er3+ photoluminescence from the erbium oxide and erbium silicate exhibits abnormal temperature dependence, which can be explained by the phonon-assisted resonant absorption of the 532-nm excitation photons into the 2H11/2 levels of Er3+ ions of the erbium compounds.

  1. Gamma-Ray Dosimetry System Using Radiation-Resistant Optical Fibers and a Luminescent Material

    International Nuclear Information System (INIS)

    Toh, K.; Nakamura, T.; Yamagishi, H.; Sakasai, K.; Soyama, K.; Shikama, T.; Nagata, S.

    2013-06-01

    Gamma-ray dosimetry system using radiation-resistant optical fibers and a luminescent material was developed for use in a damaged Fukushima Dai-ichi nuclear power plant. The system was designed to be compact and unnecessary of an external supply of electricity to a radiation sensor head with a contaminated working environment and restricted through-holes to a measurement point in the damaged reactor. The system can detect a gamma-ray dose rate at a measurement point using a couple of optical fibers and a luminescent material with a coincidence method. This system demonstrated a linear response with respect to the gamma-ray dose rate from 0.5 mGy/h to 0.1 Gy/h and the system had a capability to measure the dose rate of more than 10 2 Gy/h. (authors)

  2. Thermoluminescence characteristics of different dimensions of Ge-doped optical fibers in radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Begum, M.; Mizanur R, A. K. M.; Abdul R, H. A.; Yusoff, Z. [Multimedia University, Faculty of Engineering, 63100 Cyberjaya, Selangor Darul Ehsan (Malaysia); Begum, M. [Bangladesh Atomic Energy Commission, E-12/A, Agargaon, Sher-e-Blanga Nagar Dhaka-1207 (Bangladesh); Mat-Sharif, K. A. [Lingkaran Teknokrat Timur, Telekom Research and Development, 63000 Cyberjaya, Selangor Darul Ehsan (Malaysia); Amin, Y. M. [University of Malaya, Faculty of Science, Depatment of Physics, 50603 Kuala Lumpur (Malaysia); Bradley, D. A., E-mail: go2munmun@yahoo.com [University of Surrey, Department of Physics, Guildford GU2 7XH (United Kingdom)

    2014-08-15

    Important thermoluminescence (Tl) properties of five (5) different core sizes Ge doped optical fibers have been studied to develop new Tl material with better response. These are drawn from same preform applying different speed and tension during drawing phase. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (Sem) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in SSDL (Secondary Standard Dosimetry Lab) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are Tl linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 grades C for 1 hour period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 hour at 400 grades C and subsequently 2 hours at 100 grades C to yield the highest sensitivity. Tl responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z{sub eff}) is found in the range (13.25 to 13.69) that is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. Tl properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry. (author)

  3. The influence of different black carbon and sulfate mixing methods on their optical and radiative properties

    International Nuclear Information System (INIS)

    Zhang, Hua; Zhou, Chen; Wang, Zhili; Zhao, Shuyun; Li, Jiangnan

    2015-01-01

    Three different internal mixing methods (Core–Shell, Maxwell-Garnett, and Bruggeman) and one external mixing method are used to study the impact of mixing methods of black carbon (BC) with sulfate aerosol on their optical properties, radiative flux, and heating rate. The optical properties of a mixture of BC and sulfate aerosol particles are considered for three typical bands. The results show that mixing methods, the volume ratio of BC to sulfate, and relative humidity have a strong influence on the optical properties of mixed aerosols. Compared to internal mixing, external mixing underestimates the particle mass absorption coefficient by 20–70% and the particle mass scattering coefficient by up to 50%, whereas it overestimates the particle single scattering albedo by 20–50% in most cases. However, the asymmetry parameter is strongly sensitive to the equivalent particle radius, but is only weakly sensitive to the different mixing methods. Of the internal methods, there is less than 2% difference in all optical properties between the Maxwell-Garnett and Bruggeman methods in all bands; however, the differences between the Core–Shell and Maxwell-Garnett/Bruggeman methods are usually larger than 15% in the ultraviolet and visible bands. A sensitivity test is conducted with the Beijing Climate Center Radiation transfer model (BCC-RAD) using a simulated BC concentration that is typical of east-central China and a sulfate volume ratio of 75%. The results show that the internal mixing methods could reduce the radiative flux more effectively because they produce a higher absorption. The annual mean instantaneous radiative force due to BC–sulfate aerosol is about –3.18 W/m 2 for the external method and –6.91 W/m 2 for the internal methods at the surface, and –3.03/–1.56/–1.85 W/m 2 for the external/Core–Shell/(Maxwell-Garnett/Bruggeman) methods, respectively, at the tropopause. - Highlights: • The aerosol optical properties with different mixing

  4. Thermoluminescence characteristics of different dimensions of Ge-doped optical fibers in radiation dosimetry

    International Nuclear Information System (INIS)

    Begum, M.; Mizanur R, A. K. M.; Abdul R, H. A.; Yusoff, Z.; Begum, M.; Mat-Sharif, K. A.; Amin, Y. M.; Bradley, D. A.

    2014-08-01

    Important thermoluminescence (Tl) properties of five (5) different core sizes Ge doped optical fibers have been studied to develop new Tl material with better response. These are drawn from same preform applying different speed and tension during drawing phase. The results of the investigations are also compared with most commonly used standard TLD-100 chips (LiF:Mg,Ti) and commercial multimode Ge doped optical fiber (Yangtze Optical Fiber, China). Scanning Electron Microscope (Sem) and EDX analysis of the fibers are also performed to map Ge distribution across the deposited region. Standard Gamma radiation source in SSDL (Secondary Standard Dosimetry Lab) was used for irradiation covering dose range from 1 Gy to 10 Gy. The essential dosimetric parameters that have been studied are Tl linearity, reproducibility and fading. Prior to irradiation all samples ∼0.5 cm length are annealed at temperature of 400 grades C for 1 hour period to standardize their sensitivities and background. Standard TLD-100 chips are also annealed for 1 hour at 400 grades C and subsequently 2 hours at 100 grades C to yield the highest sensitivity. Tl responses of these fibers show linearity over a wide gamma radiation dose that is an important property for radiation dosimetry. Among all fibers used in this study, 100 μm core diameter fiber provides highest response that is 2.6 times than that of smallest core (20 μm core) optical fiber. These fiber-samples demonstrate better response than commercial multi-mode optical fiber and also provide low degree of fading about 20% over a period of fifteen days for gamma radiation. Effective atomic number (Z eff ) is found in the range (13.25 to 13.69) that is higher than soft tissue (7.5) however within the range of human-bone (11.6-13.8). All the fibers can also be re-used several times as a detector after annealing. Tl properties of the Ge-doped optical fibers indicate promising applications in ionizing radiation dosimetry. (author)

  5. Optical radiative properties of ablating polymers exposed to high-power arc plasmas

    Science.gov (United States)

    Becerra, Marley; Pettersson, Jonas

    2018-03-01

    The radiative properties of polymers exposed to high-intensity radiation are of importance for the numerical simulation of arc-induced ablation. The paper investigates the optical properties of polymethylmethacrylate PMMA and polyamide PA6 films exposed to high-power arc plasmas, which can cause ablation of the material. A four-flux radiative approximation is first used to estimate absorption and scattering coefficients of the tested materials in the ultraviolet (UV) and in the visible (VIS) ranges from spectrophotometric measurements. The temperature-induced variation of the collimated transmissivity of the polymers is also measured from room temperature to the glass temperature of PMMA and the melting temperature of PA6. Furthermore, band-averaged absorption and scattering coefficients of non-ablating and ablating polymers are estimated from the UV to the short-wavelength infrared (SWIR), covering the range of interest for the simulation of arc-induced ablation. These estimates are obtained from collimated transmissivities measured with an additional in situ photometric system that uses a high-power, transient arc plasma to both illuminate the samples and to induce ablation. It is shown that the increase in the bulk temperature of PA6 leads to a strong reversible increase in collimated transmissivity, significantly reducing the absorption and scattering coefficients of the material. A weaker but opposite effect of temperature on the optical properties is found in PMMA. As a consequence, it is suggested that the absorption coefficient of polymers used for arc-induced ablation estimates should not be taken directly from direct collimated transmissivity measurements at room temperature. The band-averaged radiation measurements also show that the layer of products released by ablation of PMMA produces scattering radiation losses mainly in the VIS-SWIR ranges, which are only a small fraction of the total incident arc radiation. In a similar manner, the ablation layer

  6. Radiation-induced defects in chalcogenide glasses characterized by combined optical spectroscopy, XPS and PALS methods

    International Nuclear Information System (INIS)

    Shpotyuk, O.; Kovalskiy, A.; Jain, H.; Golovchak, R.; Zurawska, A.

    2007-01-01

    Temperature-dependent optical absorption spectroscopy, high-resolution X-ray photoelectron spectroscopy and positron annihilation lifetimes spectroscopy are utilized to understand radiation-induced changes in Ge-Sb-S chalcogenide glasses. Theoretically predicted topological scheme of γ-induced coordination defect formation in stoichiometric Ge 23.5 Sb 11.8 S 64.7 glass composition is supported by these measurements. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Optical vortices and singularities due to interference in atomic radiation near a mirror.

    Science.gov (United States)

    Li, Xin; Shu, Jie; Arnoldus, Henk F

    2009-11-15

    We consider radiation emitted by an electric dipole close to a mirror. We have studied the field lines of the Poynting vector, representing the flow lines of the electromagnetic energy, and we show that numerous singularities and subwavelength optical vortices appear in this energy flow pattern. We also show that the field line pattern in the plane of the mirror contains a singular circle across which the field lines change direction.

  8. Optical transport and statistics of radiative losses in disordered chains of microspheres

    International Nuclear Information System (INIS)

    Deng Chaosheng; Xu Hui; Deych, Lev

    2010-01-01

    Optical transport in a one-dimensional chain of microspherical resonators with size disorder is studied in the spectral range of high-Q whispering gallery modes. An ab initio approach is used to develop a theoretical framework for analysis of steady-state transport parameters with main emphasis on properly defined radiative loss coefficient. Probability distribution and scaling properties of the latter are established and explained.

  9. The influence of different black carbon and sulfate mixing methods on their optical and radiative properties

    Science.gov (United States)

    Zhang, Hua; Zhou, Chen; Wang, Zhili; Zhao, Shuyun; Li, Jiangnan

    2015-08-01

    Three different internal mixing methods (Core-Shell, Maxwell-Garnett, and Bruggeman) and one external mixing method are used to study the impact of mixing methods of black carbon (BC) with sulfate aerosol on their optical properties, radiative flux, and heating rate. The optical properties of a mixture of BC and sulfate aerosol particles are considered for three typical bands. The results show that mixing methods, the volume ratio of BC to sulfate, and relative humidity have a strong influence on the optical properties of mixed aerosols. Compared to internal mixing, external mixing underestimates the particle mass absorption coefficient by 20-70% and the particle mass scattering coefficient by up to 50%, whereas it overestimates the particle single scattering albedo by 20-50% in most cases. However, the asymmetry parameter is strongly sensitive to the equivalent particle radius, but is only weakly sensitive to the different mixing methods. Of the internal methods, there is less than 2% difference in all optical properties between the Maxwell-Garnett and Bruggeman methods in all bands; however, the differences between the Core-Shell and Maxwell-Garnett/Bruggeman methods are usually larger than 15% in the ultraviolet and visible bands. A sensitivity test is conducted with the Beijing Climate Center Radiation transfer model (BCC-RAD) using a simulated BC concentration that is typical of east-central China and a sulfate volume ratio of 75%. The results show that the internal mixing methods could reduce the radiative flux more effectively because they produce a higher absorption. The annual mean instantaneous radiative force due to BC-sulfate aerosol is about -3.18 W/m2 for the external method and -6.91 W/m2 for the internal methods at the surface, and -3.03/-1.56/-1.85 W/m2 for the external/Core-Shell/(Maxwell-Garnett/Bruggeman) methods, respectively, at the tropopause.

  10. Monthly and seasonal variations of aerosol optical properties and direct radiative forcing over Zanjan, Iran

    Science.gov (United States)

    Gharibzadeh, Maryam; Alam, Khan; Abedini, Yousefali; Bidokhti, Abbasali Aliakbari; Masoumi, Amir

    2017-11-01

    Aerosol optical properties and radiative forcing over Zanjan in northwest of Iran has been analyzed during 2010-2013. The aerosol optical and radiative properties are less studied over Zanjan, and therefore, require a careful and in depth analysis. The optical properties like Aerosol Optical Depth (AOD), Ångström Exponent (AE), ASYmmetry parameter (ASY), Single Scattering Albedo (SSA), and Aerosol Volume Size Distribution (AVSD) have been evaluated using the ground-based AErosol RObotic NETwork (AERONET) data. Higher AOD while relatively lower AE were observed in the spring and summer, which showed the presence of coarse mode particles in these seasons. An obvious increase of coarse mode particles in AVSD distribution, as well as a higher value of SSA represented considerable addition of coarse mode particles like dust into the atmosphere of Zanjan in these two seasons. Increase in AE, while a decrease in AOD was detected in the winter and fall. The presence of fine particles indicates the dominance of particles like urban-industrial aerosols from local sources especially in the winter. The Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model was utilized to calculate the Aerosol Radiative Forcing (ARF) at the Top of the Atmosphere (TOA), earth's surface and within the atmosphere. The annual averaged ARF values were -13.47 W m-2 and -36.1 W m-2 at the TOA and earth's surface, respectively, which indicate a significant cooling effect. Likewise, the ARF efficiencies at the TOA and earth's surface were -65.08 W m-2 and -158.43 W m-2, respectively. The annual mean atmospheric ARF and heating rate within the atmosphere were 22.63 W m-2 and 0.27 Kday-1 respectively, represented the warming effect within the atmosphere. Finally, a good agreement was found between AERONET retrieved ARF and SBDART simulated ARF.

  11. Does altered fractionation influence the risk of radiation-induced optic neuropathy?

    International Nuclear Information System (INIS)

    Bhandare, Niranjan; Monroe, Alan T.; Morris, Christopher G.; Bhatti, M. Tariq; Mendenhall, William M.

    2005-01-01

    Purpose: To analyze the parameters that influence the risk of radiation-induced optic neuropathy (RION) after radiotherapy for head-and-neck tumors. Methods and Materials: Between 1964 and 2000, 273 patients with tumors of the nasopharynx, paranasal sinuses, nasal cavity, and hard palate adenoid cystic carcinomas were treated with curative intent and had radiation fields that included the optic nerves and/or chiasm. Patients were followed for at least 1 year after radiotherapy. Results: Radiation-induced optic neuropathy developed in 32 eyes of 24 patients (9%). The 5-year rates of freedom from RION according to the total dose and once- vs. twice-daily fractionation were as follows: ≤63 Gy once daily, 95%; ≤63 Gy twice daily, 98%; >63 Gy once daily, 78%; and >63 Gy twice daily, 91%. Multivariate analysis revealed that the total dose affected the risk of RION (p = 0.0047), with patient age (p = 0.0909), once-daily vs. twice-daily fractionation (p = 0.0684), and overall treatment time (p = 0.0972) were marginally significant. The use of adjuvant chemotherapy did not significantly influence the likelihood of developing RION. Conclusion: The likelihood of developing RION is primarily influenced by the total dose. Hyperfractionation may reduce the risk of experiencing this complication

  12. Evaluating contextual processing in diffusion MRI: application to optic radiation reconstruction for epilepsy surgery.

    Directory of Open Access Journals (Sweden)

    Chantal M W Tax

    Full Text Available Diffusion MRI and tractography allow for investigation of the architectural configuration of white matter in vivo, offering new avenues for applications like presurgical planning. Despite the promising outlook, there are many pitfalls that complicate its use for (clinical application. Amongst these are inaccuracies in the geometry of the diffusion profiles on which tractography is based, and poor alignment with neighboring profiles. Recently developed contextual processing techniques, including enhancement and well-posed geometric sharpening, have shown to result in sharper and better aligned diffusion profiles. However, the research that has been conducted up to now is mainly of theoretical nature, and so far these techniques have only been evaluated by visual inspection of the diffusion profiles. In this work, the method is evaluated in a clinically relevant application: the reconstruction of the optic radiation for epilepsy surgery. For this evaluation we have developed a framework in which we incorporate a novel scoring procedure for individual pathways. We demonstrate that, using enhancement and sharpening, the extraction of an anatomically plausible reconstruction of the optic radiation from a large amount of probabilistic pathways is greatly improved in three healthy controls, where currently used methods fail to do so. Furthermore, challenging reconstructions of the optic radiation in three epilepsy surgery candidates with extensive brain lesions demonstrate that it is beneficial to integrate these methods in surgical planning.

  13. Test and Evaluation of Fiber Optic Sensors for High-Radiation Space Nuclear Power Applications

    International Nuclear Information System (INIS)

    Klemer, Daniel; Fielder, Robert S.; Stinson-Bagby, Kelly L.

    2004-01-01

    Fiber optic sensors can be used to measure a number of parameters, including temperature, strain, pressure and flow, for instrumentation and control of space nuclear power systems. In the past, this technology has often been rejected for use in such a high-radiation environment based on early experiments that revealed a number of degradation phenomena, including radiation-induced fiber attenuation, or 'graying', and Fiber Bragg Grating (FBG) fading and wavelength shift. However, this paper reports the results of recent experimental testing that demonstrates readability of fiber optic sensors to extremely high levels of neutron and gamma radiation. Both distributed Fiber Bragg Grating (FBG) sensors and single-point Extrinsic Fabry Perot Interferometer (EFPI) sensors were continuously monitored over a 2-month period, during which they were exposed to combined neutron and gamma radiation in both in-core and ex-core positions within a nuclear reactor. Total exposure reached approximately 2 x 10 19 cm -2 fast neutron (E > 1 MeV) fluence and 8.7 x 10 8 Gy gamma for in-core sensors. FBG sensors were interrogated using a standard Luna Innovations FBG measurement system, which is based on optical frequency-domain reflectometer (OFDR) technology. Approximately 74% of the 19 FBG sensors located at the core centerline in the in-core position exhibited sufficient signal-to-noise ratio (SNR) to remain readable even after receiving the maximum dose. EFPI sensors were spectrally interrogated using a broadband probe source operating in the 830 nm wavelength region. While these single-point sensors failed early in the test, important additional fiber spectral transmission data was collected, which indicates that interrogation of EFPI sensors in alternate wavelength regions may allow significant improvement in sensor longevity for operation in high-radiation environments. This work was funded through a Small Business Innovative Research (SBIR) contract with the Nasa Glenn Research

  14. Contrasting aerosol optical and radiative properties between dust and urban haze episodes in megacities of Pakistan

    Science.gov (United States)

    Iftikhar, Muhammad; Alam, Khan; Sorooshian, Armin; Syed, Waqar Adil; Bibi, Samina; Bibi, Humera

    2018-01-01

    Satellite and ground based remote sensors provide vital information about aerosol optical and radiative properties. Analysis of aerosol optical and radiative properties during heavy aerosol loading events in Pakistan are limited and, therefore, require in-depth examination. This work examines aerosol properties and radiative forcing during Dust Episodes (DE) and Haze Episodes (HE) between 2010 and 2014 over mega cities of Pakistan (Karachi and Lahore). Episodes having the daily averaged values of Aerosol Optical Depth (AOD) exceeding 1 were selected. DE were associated with high AOD and low Ångström Exponent (AE) over Karachi and Lahore while high AOD and high AE values were associated with HE over Lahore. Aerosol volume size distributions (AVSD) exhibited a bimodal lognormal distribution with a noticeable coarse mode peak at a radius of 2.24 μm during DE, whereas a fine mode peak was prominent at a radius 0.25 μm during HE. The results reveal distinct differences between HE and DE for spectral profiles of several parameters including Single Scattering Albedo (SSA), ASYmmetry parameter (ASY), and the real and imaginary components of refractive index (RRI and IRI). The AOD-AE correlation revealed that dust was the dominant aerosol type during DE and that biomass burning and urban/industrial aerosol types were pronounced during HE. Aerosol radiative forcing (ARF) was estimated using the Santa Barbra DISORT Atmospheric Radiative Transfer (SBDART) model. Calculations revealed a negative ARF at the Top Of the Atmosphere (ARFTOA) and at the Bottom Of the Atmosphere (ARFBOA), with positive ARF within the Atmosphere (ARFATM) during both DE and HE over Karachi and Lahore. Furthermore, estimations of ARFATM by SBDART were shown to be in good agreement with values derived from AERONET data for DE and HE over Karachi and Lahore.

  15. Optical properties reconstruction using the adjoint method based on the radiative transfer equation

    Science.gov (United States)

    Addoum, Ahmad; Farges, Olivier; Asllanaj, Fatmir

    2018-01-01

    An efficient algorithm is proposed to reconstruct the spatial distribution of optical properties in heterogeneous media like biological tissues. The light transport through such media is accurately described by the radiative transfer equation in the frequency-domain. The adjoint method is used to efficiently compute the objective function gradient with respect to optical parameters. Numerical tests show that the algorithm is accurate and robust to retrieve simultaneously the absorption μa and scattering μs coefficients for lowly and highly absorbing medium. Moreover, the simultaneous reconstruction of μs and the anisotropy factor g of the Henyey-Greenstein phase function is achieved with a reasonable accuracy. The main novelty in this work is the reconstruction of g which might open the possibility to image this parameter in tissues as an additional contrast agent in optical tomography.

  16. Development of a synchrotron radiation beam monitor for the Integrable Optics Test Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Scarpelli, Andrea [Univ. of Ferrara (Italy)

    2016-01-01

    Nonlinear integrable optics applied to beam dynamics may mitigate multi-particle instabilities, but proof of principle experiments have never been carried out. The Integrable Optics Test Accelerator (IOTA) is an electron and proton storage ring currently being built at Fermilab, which addresses tests of nonlinear lattice elements in a real machine in addition to experiments on optical stochastic cooling and on the single-electron wave function. These experiments require an outstanding control over the lattice parameters, achievable with fast and precise beam monitoring systems. This work describes the steps for designing and building a beam monitor for IOTA based on synchrotron radiation, able to measure intensity, position and transverse cross-section beam.

  17. Development of novel imaging probe for optical/acoustic radiation imaging (OARI).

    Science.gov (United States)

    Ejofodomi, O'tega A; Zderic, Vesna; Zara, Jason M

    2013-11-01

    Optical/acoustic radiation imaging (OARI) is a novel imaging modality being developed to interrogate the optical and mechanical properties of soft tissues. OARI uses acoustic radiation force to generate displacement in soft tissue. Optical images before and after the application of the force are used to generate displacement maps that provide information about the mechanical properties of the tissue under interrogation. Since the images are optical images, they also represent the optical properties of the tissue as well. In this paper, the authors present the first imaging probe that uses acoustic radiation force in conjunction with optical coherence tomography (OCT) to provide information about the optical and mechanical properties of tissues to assist in the diagnosis and staging of epithelial cancers, and in particular bladder cancer. The OARI prototype probe consisted of an OCT probe encased in a plastic sheath, a miniaturized transducer glued to a plastic holder, both of which were encased in a 10 cm stainless steel tube with an inner diameter of 10 mm. The transducer delivered an acoustic intensity of 18 W/cm(2) and the OCT probe had a spatial resolution of approximately 10-20 μm. The tube was filled with deionized water for acoustic coupling and covered by a low density polyethylene cap. The OARI probe was characterized and tested on bladder wall phantoms. The phantoms possessed Young's moduli ranging from 10.2 to 12 kPa, mass density of 1.05 g/cm(3), acoustic attenuation coefficient of 0.66 dB/cm MHz, speed of sound of 1591 m/s, and optical scattering coefficient of 1.80 mm(-1). Finite element model (FEM) theoretical simulations were performed to assess the performance of the OARI probe. The authors obtained displacements of 9.4, 8.7, and 3.4 μm for the 3%, 4%, and 5% bladder wall phantoms, respectively. This shows that the probe is capable of generating optical images, and also has the ability to generate and track displacements in tissue. This will

  18. Circular heat and momentum flux radiated by magneto-optical nanoparticles

    Science.gov (United States)

    Ott, A.; Ben-Abdallah, P.; Biehs, S.-A.

    2018-05-01

    In the present article we investigate the heat and momentum fluxes radiated by a hot magneto-optical nanoparticle in its surroundings under the action of an external magnetic field. We show that the flux lines circulate in a confined region at a nanometric distance from the particle around the axis of the magnetic field in a vortexlike configuration. Moreover we prove that the spatial orientation of these vortices (clockwise or counterclockwise) is associated with the contribution of optical resonances with topological charges m =+1 or m =-1 to the thermal emission. This work paves the way for a geometric description of heat and momentum transport in lattices of magneto-optical particles. Moreover it could have important applications in the field of energy storage as well as in thermal management at nanoscale.

  19. Radiation hardening techniques for rare-earth based optical fibers and amplifiers

    International Nuclear Information System (INIS)

    Girard, Sylvain; Marcandella, Claude; Vivona, Marilena; Prudenzano, Luciano Mescia F.; Laurent, Arnaud; Robin, Thierry; Cadier, Benoit; Pinsard, Emmanuel; Ouerdane, Youcef; Boukenter, Aziz; Cannas, Marco; Boscaino, Roberto

    2012-01-01

    Er/Yb doped fibers and amplifiers have been shown to be very radiation sensitive, limiting their integration in space. We present an approach including successive hardening techniques to enhance their radiation tolerance. The efficiency of our approach is demonstrated by comparing the radiation responses of optical amplifiers made with same lengths of different rare-earth doped fibers and exposed to gamma-rays. Previous studies indicated that such amplifiers suffered significant degradation for doses exceeding 10 krad. Applying our techniques significantly enhances the amplifier radiation resistance, resulting in a very limited degradation up to 50 krad. Our optimization techniques concern the fiber composition, some possible pre-treatments and the interest of simulation tools used to harden by design the amplifiers. We showed that adding cerium inside the fiber phospho-silicate-based core strongly decreases the fiber radiation sensitivity compared to the standard fiber. For both fibers, a pre-treatment with hydrogen permits to enhance again the fiber resistance. Furthermore, simulations tools can also be used to improve the tolerance of the fiber amplifier by helping identifying the best amplifier configuration for operation in the radiative environment. (authors)

  20. Optical fiber radiation sensors: first in vivo measurements during orbital irradiation

    International Nuclear Information System (INIS)

    Gripp, S.; Bannach, B.; Muskalla, K.; Haesing, F.; Bueker, H.; Schmitt, G.

    1995-01-01

    Purpose: To investigate the applicability of doped optical fiber radiation sensors in clinical dosimetry. Methods: Ionizing radiation causes a dose depending discoloring in silica. When proper impurities (doping agents) are added, the radiation sensitivity may be increased to a range suited for clinical dosimetry. We performed in-vivo-measurements using a lead doped silica fiber (d TM ) in comparison to thermoluminescence detectors (TLDs). Results: The scattered radiation is easily detected with this sensor fiber. In contrast to TLDs the dose and doserate values are obtained immediately and setup errors can be recognized before irradiation is completed. The SD clearly depends on setup modifications due to the extent of disease. Other doping agents (GeP) provide better tissue equivalence and less energy dependence. Conclusions: Optical fibers are suitable for in vivo dosimetry purposes. Fiber sensors provide real time dose values, and the readout procedure is much easier compared to TLDs. These features may gain significance in quality assurance, conformal therapy, and intraoperative radiotherapy (IORT)