WorldWideScience

Sample records for ultrafast radiation detection

  1. Optical Detection in Ultrafast Short Wavelength Science

    International Nuclear Information System (INIS)

    Fullagar, Wilfred K.; Hall, Chris J.

    2010-01-01

    A new approach to coherent detection of ionising radiation is briefly motivated and recounted. The approach involves optical scattering of coherent light fields by colour centres in transparent solids. It has significant potential for diffractive imaging applications that require high detection dynamic range from pulsed high brilliance short wavelength sources. It also motivates new incarnations of Bragg's X-ray microscope for pump-probe studies of ultrafast molecular structure-dynamics.

  2. Ultrafast molecular dynamics illuminated with synchrotron radiation

    International Nuclear Information System (INIS)

    Bozek, John D.; Miron, Catalin

    2015-01-01

    Highlights: • Ultrafast molecular dynamics probed with synchrotron radiation. • Core-excitation as probe of ultrafast dynamics through core-hole lifetime. • Review of experimental and theoretical methods in ultrafast dynamics using core-level excitation. - Abstract: Synchrotron radiation is a powerful tool for studying molecular dynamics in small molecules in spite of the absence of natural matching between the X-ray pulse duration and the time scale of nuclear motion. Promoting core level electrons to unoccupied molecular orbitals simultaneously initiates two ultrafast processes, nuclear dynamics on the potential energy surfaces of the highly excited neutral intermediate state of the molecule on the one hand and an ultrafast electronic decay of the intermediate excited state to a cationic final state, characterized by a core hole lifetime. The similar time scales of these processes enable core excited pump-probe-type experiments to be performed with long duration X-ray pulses from a synchrotron source. Recent results obtained at the PLIEADES beamline concerning ultrafast dissociation of core excited states and molecular potential energy curve mapping facilitated by changes in the geometry of the short-lived intermediate core excited state are reviewed. High brightness X-ray beams combined with state-of-the art electron and ion-electron coincidence spectrometers and highly sophisticated theoretical methods are required to conduct these experiments and to achieve a full understanding of the experimental results.

  3. Ultrafast outflows disappear in high-radiation fields

    Science.gov (United States)

    Pinto, C.; Alston, W.; Parker, M. L.; Fabian, A. C.; Gallo, L. C.; Buisson, D. J. K.; Walton, D. J.; Kara, E.; Jiang, J.; Lohfink, A.; Reynolds, C. S.

    2018-05-01

    Ultrafast outflows (UFOs) are the most extreme winds launched by active galactic nuclei (AGN) due to their mildly relativistic speeds (˜0.1-0.3c) and are thought to significantly contribute to galactic evolution via AGN feedback. Their nature and launching mechanism are however not well understood. Recently, we have discovered the presence of a variable UFO in the narrow-line Seyfert 1 IRAS 13224-3809. The UFO varies in response to the brightness of the source. In this work we perform flux-resolved X-ray spectroscopy to study the variability of the UFO and found that the ionization parameter is correlated with the luminosity. In the brightest states the gas is almost completely ionized by the powerful radiation field and the UFO is hardly detected. This agrees with our recent results obtained with principal component analysis. We might have found the tip of the iceberg: the high ionization of the outflowing gas may explain why it is commonly difficult to detect UFOs in AGN and possibly suggest that we may underestimate their actual feedback. We have also found a tentative correlation between the outflow velocity and the luminosity, which is expected from theoretical predictions of radiation-pressure-driven winds. This trend is rather marginal due to the Fe XXV-XXVI degeneracy. Further work is needed to break such degeneracy through time-resolved spectroscopy.

  4. Detection of Terahertz Radiation

    DEFF Research Database (Denmark)

    2015-01-01

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

  5. Ultrafast electron microscopy integrated with a direct electron detection camera

    Directory of Open Access Journals (Sweden)

    Young Min Lee

    2017-07-01

    Full Text Available In the past decade, we have witnessed the rapid growth of the field of ultrafast electron microscopy (UEM, which provides intuitive means to watch atomic and molecular motions of matter. Yet, because of the limited current of the pulsed electron beam resulting from space-charge effects, observations have been mainly made to periodic motions of the crystalline structure of hundreds of nanometers or higher by stroboscopic imaging at high repetition rates. Here, we develop an advanced UEM with robust capabilities for circumventing the present limitations by integrating a direct electron detection camera for the first time which allows for imaging at low repetition rates. This approach is expected to promote UEM to a more powerful platform to visualize molecular and collective motions and dissect fundamental physical, chemical, and materials phenomena in space and time.

  6. Ultrafast electron microscopy integrated with a direct electron detection camera.

    Science.gov (United States)

    Lee, Young Min; Kim, Young Jae; Kim, Ye-Jin; Kwon, Oh-Hoon

    2017-07-01

    In the past decade, we have witnessed the rapid growth of the field of ultrafast electron microscopy (UEM), which provides intuitive means to watch atomic and molecular motions of matter. Yet, because of the limited current of the pulsed electron beam resulting from space-charge effects, observations have been mainly made to periodic motions of the crystalline structure of hundreds of nanometers or higher by stroboscopic imaging at high repetition rates. Here, we develop an advanced UEM with robust capabilities for circumventing the present limitations by integrating a direct electron detection camera for the first time which allows for imaging at low repetition rates. This approach is expected to promote UEM to a more powerful platform to visualize molecular and collective motions and dissect fundamental physical, chemical, and materials phenomena in space and time.

  7. Counterbalanced radiation detection system

    International Nuclear Information System (INIS)

    Platz, W.

    1987-01-01

    A counterbalanced radiation detection system is described comprising: (a) a stand; (b) a first radiation detector; (c) a first radiation detector arm means for tiltably connecting the first radiation detector with the stand; (d) a second radiation detector; (e) a second radiation detector arm means for tiltably connecting the second radiation detector with the stand, whereby the tilting angles of the radiation detector arm means define a distance between the radiation detectors; and (f) a torque transforming means connected between the first and second radiation detector arm means for transforming the torque created by one of the radiation detectors in a sense opposed to the torque created by the other radiation detector

  8. Photo-conductive detection of continuous THz waves via manipulated ultrafast process in nanostructures

    Science.gov (United States)

    Moon, Kiwon; Lee, Eui Su; Lee, Il-Min; Park, Dong Woo; Park, Kyung Hyun

    2018-01-01

    Time-domain and frequency-domain terahertz (THz) spectroscopy systems often use materials fabricated with exotic and expensive methods that intentionally introduce defects to meet short carrier lifetime requirements. In this study, we demonstrate the development of a nano-photomixer that meets response speed requirements without using defect-incorporated, low-temperature-grown (LTG) semiconductors. Instead, we utilized a thin InGaAs layer grown on a semi-insulating InP substrate by metal-organic chemical vapor deposition (MOCVD) combined with nano-electrodes to manipulate local ultrafast photo-carrier dynamics via a carefully designed field-enhancement and plasmon effect. The developed nano-structured photomixer can detect continuous-wave THz radiation up to a frequency of 2 THz with a peak carrier collection efficiency of 5%, which is approximately 10 times better than the reference efficiency of 0.4%. The better efficiency results from the high carrier mobility of the MOCVD-grown InGaAs thin layer with the coincidence of near-field and plasmon-field distributions in the nano-structure. Our result not only provides a generally applicable methodology for manipulating ultrafast carrier dynamics by means of nano-photonic techniques to break the trade-off relation between the carrier lifetime and mobility in typical LTG semiconductors but also contributes to mass-producible photo-conductive THz detectors to facilitate the widespread application of THz technology.

  9. Detection of coronary calcification in ultrafast CT compared to coronary angiography

    International Nuclear Information System (INIS)

    Koesling, S.; Hoffmann, U.; Rother, T.; Lieberenz, S.; Heywang-Koebrunner, S.H.; Schulz, H.G.

    1994-01-01

    The angiographical findings of 24 patients with coronary artery disease were compared with qualitative and quantitative detection of coronary calcification by ultrafast CT. Doubts concerning the capabilities of the ultrafast CT for a screening of coronary artery disease arise when the results of one third false positive and fase negative findings are considered. Variations in the quantification of coronary calcification were too great to allow a realistic assessment of the degree of stenosis of the coronary arteries. (orig.) [de

  10. Counterbalanced radiation detection device

    International Nuclear Information System (INIS)

    Platz, W.

    1986-01-01

    A counterbalanced radiation detection device is described which consists of: (a) a base; (b) a radiation detector having a known weight; (c) means connected with the radiation detector and the base for positioning the radiation detector in different heights with respect to the base; (d) electronic component means movably mounted on the base for counterbalancing the weight of the radiation detector; (e) means connected with the electronic component means and the radiation detector positioning means for positioning the electronic component means in different heights with respect to the base opposite to the heights of the radiation detector; (f) means connected with the radiation detector and the base for shifting the radiation detector horizontally with respect to the base; and (g) means connected with the electronic component means and the radiation detector shifting means for shifting the electronic component means horizontally with respect to the base in opposite direction to shifting of the radiation detector

  11. Semiconductor radiation detection systems

    CERN Document Server

    2010-01-01

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

  12. 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...

  13. Radiation detection system

    International Nuclear Information System (INIS)

    Haeuszer, F.A.

    1976-01-01

    A circuit is disclosed that detects radiation transients and provides a clamping signal in response to each transient. The clamping signal is present from the time the transient rises above a given threshold level and for a known duration thereafter. The system includes radiation sensors, a blocking oscillator that generates a pulse in response to each sensor signal, and an output pulse duration control circuit. The oscillator pulses are fed simultaneously to the output pulse duration control circuit and to an OR gate, the output of which comprises the system output. The output pulse duration is controlled by the time required to magnetize a magnetic core to saturation in first one direction and then the other

  14. Ultrafast laser based coherent control methods for explosives detection

    Energy Technology Data Exchange (ETDEWEB)

    Moore, David Steven [Los Alamos National Laboratory

    2010-12-06

    The detection of explosives is a notoriously difficult problem, especially at stand-off, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring Optimal Dynamic Detection of Explosives (ODD-Ex), which exploits the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity to explosives signatures while dramatically improving specificity, particularly against matrix materials and background interferences. These goals are being addressed by operating in an optimal non-linear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe subpulses. Recent results will be presented.

  15. Radiation detection and measurement

    International Nuclear Information System (INIS)

    Knoll, G.F.

    1979-01-01

    Introductory material covers radiation sources, radiation interactions, general properties of radiation detectors, and counting statistics and error prediction. This is followed by detailed sections on gas-filled detectors, scintillation counters, semiconductor detectors, neutron detectors and spectroscopy, detector electronics and pulse processing, and miscellaneous radiation detectors and applications

  16. Measurement and detection of radiation

    National Research Council Canada - National Science Library

    Tsoulfanidis, Nicholas; Landsberger, Sheldon

    2011-01-01

    .... With the miniaturization of equipment, increased speed of electronic components, and more sophisticated software, radiation detection systems are now more productively used in many disciplines...

  17. Terahertz radiation from accelerating charge carriers in graphene under ultrafast photoexcitation

    Science.gov (United States)

    Rustagi, Avinash; Stanton, C. J.

    2016-11-01

    We study the generation of terahertz (THz) radiation from the acceleration of ultrafast photoexcited charge carriers in graphene in the presence of a dc electric field. Our model is based on calculating the transient current density from the time-dependent distribution function which is determined using the Boltzmann transport equation (BTE) within a relaxation time approximation. We include the time-dependent generation of carriers by the pump pulse by solving for the carrier generation rate using the optical Bloch equations in the rotating wave approximation (RWA). The linearly polarized pump pulse generates an anisotropic distribution of photoexcited carriers in the kx-ky plane. The collision integral in the Boltzmann equation includes a term that leads to the thermalization of carriers via carrier-carrier scattering to an effective temperature above the lattice temperature, as well as a cooling term, which leads to energy relaxation via inelastic carrier-phonon scattering. The radiated signal is proportional to the time derivative of the transient current density. In spite of the fact that the magnitude of the velocity is the same for all the carriers in graphene, there is still emitted radiation from the photoexcited charge carriers with frequency components in the THz range due to a change in the direction of velocity of the photoexcited carriers in the external electric field as well as cooling of the photoexcited carriers on a subpicosecond time scale.

  18. Ultra-fast low concentration detection of Candida pathogens utilizing high resolution micropore chips.

    Science.gov (United States)

    Mulero, Rafael; Lee, Dong Heun; Kutzler, Michele A; Jacobson, Jeffrey M; Kim, Min Jun

    2009-01-01

    Although Candida species are the fourth most common cause of nosocomial blood stream infections in the United States, early diagnostic tools for invasive candidemia are lacking. Due to an increasing rate of candidemia, a new screening system is needed to detect the Candida species in a timely manner. Here we describe a novel method of detection using a solid-state micro-scale pore similar to the operational principles of a Coulter counter. With a steady electrolyte current flowing through the pore, measurements are taken of changes in the current corresponding to the shape of individual yeasts as they translocate or travel through the pore. The direct ultra-fast low concentration electrical addressing of C. albicans has established criteria for distinguishing individual yeast based on their structural properties, which may reduce the currently used methods' complexity for both identification and quantification capabilities in mixed blood samples.

  19. Ultra-Fast Low Concentration Detection of Candida Pathogens Utilizing High Resolution Micropore Chips

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available Although Candida species are the fourth most common cause of nosocomial blood stream infections in the United States, early diagnostic tools for invasive candidemia are lacking. Due to an increasing rate of candidemia, a new screening system is needed to detect the Candida species in a timely manner. Here we describe a novel method of detection using a solid-state micro-scale pore similar to the operational principles of a Coulter counter. With a steady electrolyte current flowing through the pore, measurements are taken of changes in the current corresponding to the shape of individual yeasts as they translocate or travel through the pore. The direct ultra-fast low concentration electrical addressing of C. albicans has established criteria for distinguishing individual yeast based on their structural properties, which may reduce the currently used methods’ complexity for both identification and quantification capabilities in mixed blood samples

  20. Sensitive and ultra-fast species detection using pulsed cavity ringdown spectroscopy

    KAUST Repository

    Alquaity, Awad

    2015-01-01

    Pulsed cavity ringdown spectroscopy (CRDS) is used to develop a novel, ultra-fast, high-sensitivity diagnostic for measuring species concentrations in shock tube experiments. The diagnostic is demonstrated by monitoring trace concentrations of ethylene in the mid-IR region near 949.47 cm-1. Each ringdown measurement is completed in less than 1 μs and the time period between successive pulses is 10 μs. The high sensitivity diagnostic has a noise-equivalent detection limit of 1.08 x 10-5 cm-1 which enables detection of 15 ppm ethylene at fuel pyrolysis conditions (1845 K and 2 bar) and 294 ppb ethylene under ambient conditions (297 K and 1 bar). To our knowledge, this is the first successful application of the cavity ringdown method to the measurement of species time-histories in a shock tube. © 2015 OSA.

  1. Radiation detection device and a radiation detection method

    International Nuclear Information System (INIS)

    Blum, A.

    1975-01-01

    A radiation detection device is described including at least one scintillator in the path of radiation emissions from a distributed radiation source; a plurality of photodetectors for viewing each scintillator; a signal processing means, a storage means, and a data processing means that are interconnected with one another and connected to said photodetectors; and display means connected to the data processing means to locate a plurality of radiation sources in said distributed radiation source and to provide an image of the distributed radiation sources. The storage means includes radiation emission response data and location data from a plurality of known locations for use by the data processing means to derive a more accurate image by comparison of radiation responses from known locations with radiation responses from unknown locations. (auth)

  2. Measurement and detection of radiation

    CERN Document Server

    Tsoulfanidis, Nicholas

    2015-01-01

    This fourth edition reflects recent major developments that have occurred in radiation detector materials, systems, and applications. It continues to provide the most practical and up-to-date introduction to radiation detector technology, proper measurement techniques, and analysis of results for engineers and scientists using radiation sources. New chapters emphasize the expanded use of radiation detection systems in nuclear non-proliferation, homeland security, and nuclear medicine. The book also discusses the correct ways to perform measurements following current health physics procedures.

  3. Radiation detection and measurement

    International Nuclear Information System (INIS)

    Knoll, G.F.

    1979-01-01

    The book is a complete, clear and up-to-date text that provides a basic review of instruments and methods of ionizing radiation. The text covers detailed discussion of all detector types introductory discussions of radiation sources, interactions, and counting statistics functional analysis of the electronics and pulse processing aspects of radiation detectors in instrumentation systems and consideration of shielding and background potentially vital in low-level counting. A total of 350 figures and approximately 900 references to current scientific literature is included. The book is largely intended as a textbook for a junior/senior or first-year graduate course in nuclear instrumentation and radiation measurements

  4. Electronics for radiation detection

    CERN Document Server

    2011-01-01

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

  5. Measurement and detection of radiation

    CERN Document Server

    Tsoulfanidis, Nicholas

    2011-01-01

    This is an update of the standard textbook for the field of radiation measurement. It includes illustrative examples and new problems. The research and applications of nuclear instrumentation have grown substantially since publication of the previous editions. With the miniaturization of equipment, increased speed of electronic components, and more sophisticated software, radiation detection systems are now more productively used in many disciplines, including nuclear nonproliferation, homeland security, and nuclear medicine. Continuing in the tradition of its bestselling predecessors, "Measurement and Detection of Radiation, Third Edition" illustrates the fundamentals of nuclear interactions and radiation detection with a multitude of examples and problems. It offers a clearly written, accessible introduction to nuclear instrumentation concepts. The following are new to the third edition: a new chapter on the latest applications of radiation detection, covering nuclear medicine, dosimetry, health physics, no...

  6. Detection of coronary artery calcification by ultrafast CT and correlation with angiography

    International Nuclear Information System (INIS)

    Zhang Shaoxiong; Dai Ruping; Lu Bin

    1997-01-01

    To investigate the relationship between coronary calcification and significant coronary stenosis ninety patients including 81 men and 9 women were studied asithage ranging from 27∼72 years (mean, 58 years). All patients had both ultrafast CT (UFCT) examination and coronary angiography within one month. Single slice mode with ECG gating and thickness of 3 mm were used in UFCT scan. Selected coronary angiography was performed by the Judkins technique. Among 160 vessels in which coronary calcifications were identified, 74% had significant coronary stenosis (>50% stenosis), and 77% of 154 vessels with significant coronary stenosis had calcification demonstrable by UFCT. In the younger age group the sensitivity of calcification for evaluating stenosis of coronary artery was lower and the specificity was generally higher than those in the elderly group. UFCT is a promising procedure for detecting coronary arterial disease, since this examination has high sensitivity and specificity, easy to conduct, noninvasive, and widely applicable for screening a large population

  7. Radiation detection system

    Science.gov (United States)

    Whited, R.C.

    A system for obtaining improved resolution in relatively thick semiconductor radiation detectors, such as HgI/sub 2/, which exhibit significant hole trapping. Two amplifiers are used: the first measures the charge collected and the second the contribution of the electrons to the charge collected. The outputs of the two amplifiers are utilized to unfold the total charge generated within the detector in response to a radiation event.

  8. Ultrafast photocurrents and terahertz radiation in gallium arsenide and carbon based nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Prechtel, Hans Leonhard

    2011-08-15

    In this thesis we developed a measurement technique based on a common pump-probe scheme and coplanar stripline circuits that enables time-resolved photocurrent measurements of contacted nanosystems with a micrometer spatial and a picosecond time resolution. The measurement technique was applied to lowtemperature grown gallium arsenide (LT-GaAs), carbon nanotubes (CNTs), graphene, and p-doped gallium arsenide (GaAs) nanowires. The various mechanisms responsible for the generation of current pulses by pulsed laser excitation were reviewed. Furthermore the propagation of the resulting electromagnetic radiation along a coplanar stripline circuit was theoretically and numerically treated. The ultrafast photocurrent response of low-temperature grown GaAs was investigated. We found two photocurrent pulses in the time-resolved response. We showed that the first pulse is consistent with a displacement current pulse. We interpreted the second pulse to result from a transport current process. We further determined the velocity of the photo-generated charge carriers to exceed the drift, thermal and quantum velocities of single charge carriers. Hereby, we interpreted the transport current pulse to stem from an electron-hole plasma excitation. We demonstrated that the photocurrent response of CNTs comprises an ultrafast displacement current and a transport current. The data suggested that the photocurrent is finally terminated by the recombination lifetime of the charge carriers. To the best of our knowledge, we presented in this thesis the first recombination lifetime measurements of contacted, suspended, CVD grown CNT networks. In addition, we studied the ultrafast photocurrent dynamics of freely suspended graphene contacted by metal electrodes. At the graphene-metal interface, we demonstrated that built-in electric fields give rise to a photocurrent with a full-width-half-maximum of a few picoseconds and that a photo-thermoelectric effect generates a current with a decay time

  9. Aerial Radiation Detection

    International Nuclear Information System (INIS)

    Quam, W. M.

    1999-01-01

    An airborne system designed for the detection of radioactive sources on the soil surface from an aircraft normally senses gamma rays emitted by the source. Gamma rays have the longest path length (least attenuation) through the air of any of the common radioactive emissions and will thus permit source detection at large distances. A secondary benefit from gamma rays detection if that nearly all radioactive isotopes can be identified by the spectrum of gammas emitted. Major gaseous emissions from fuel processing plants emit gammas that may be detected and identified. Some types of special nuclear material also emit neutrons which are also useful for detection at a distance

  10. Detection of nuclear radiations

    International Nuclear Information System (INIS)

    Tanarro Sanz, A.

    1959-01-01

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

  11. Detection of nuclear radiations

    International Nuclear Information System (INIS)

    Tanarro Sanz, A.

    1967-01-01

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

  12. Detection of gravitational radiation

    Energy Technology Data Exchange (ETDEWEB)

    Holten, J.W. van [ed.

    1994-12-31

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

  13. Detection of gravitational radiation

    International Nuclear Information System (INIS)

    Holten, J.W. van

    1994-01-01

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

  14. Radiation detecting system

    International Nuclear Information System (INIS)

    1975-01-01

    In spectrophotometry systems, a usual arrangement for modulating the radiation is a rotating disc having one or more sectors removed. A beam of radiation may be blocked by the disc except when a cut-away sector is in the path of the beam. With a double-beam system, a cut-away sector of 180 0 may be used so that when the first path is blocked, the second is allowed through, and vice versa. One or both sides of the disc may be formed as mirrors to facilitate beam switching and to allow use of more than two beams for background compensation purposes or for analysis of more than one substance within a sample. (G.T.H.)

  15. Radiation detection systems

    International Nuclear Information System (INIS)

    Rozsa, Sandor

    1989-01-01

    Principles and operation of radiation detectors used for industrial and laboratory radiometric measurements are reviewed. The discussed detector types are as follows: ionization chamber, proportional counter, Geiger-Mueller counter, semiconductor detectors, scintillation counter and scintillators, photomultiplier tube, scintillation spectrometer and scintillation detector with semiconductor light sensor. A brief overview of the detectors of industrial nuclear instruments is also presented. (R.P.) 32 figs.; 3 tabs

  16. Ultrafast endothermic transfer of non-radiative exciplex state to radiative excitons in polyfluorene random copolymer for blue electroluminescence

    Science.gov (United States)

    Moghe, Dhanashree A.; Dey, Amrita; Johnson, Kerr; Lu, L.-P.; Friend, Richard H.; Kabra, Dinesh

    2018-04-01

    We report a blue-emitting random copolymer (termed modified Aryl-F8) consisting of three repeat units of polydioctylfluorene (F8), Aryl-polydioctylfluorene (Aryl-F8), and an aromatic amine comonomer unit, poly(bis-N,Ν'-(4-butylphenyl)-bis-N,N'-phenyl-1,4 phenylenediamine) chemically linked to get an improved charge carrier balance without compromising on the photoluminescence (PL) quantum yield with respect to the Aryl-F8 homo-polymer. The measured photoluminescence quantum efficiency (˜70%) of the blue-emitting polymer is comparable to or greater than the individual monomer units. The time resolved PL spectra from the modified Aryl-F8 are similar to those of Arylated-poly(9,9'-dioctylfluorene-co-bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-1,4 phenylenediamine) (PFB) even at a time scale of 100-250 ps, indicating an ultrafast energy transfer from the (Aryl-F8 or F8):Arylated-PFB interface to Arylated-PFB, i.e., endothermic transfer of non-radiative exciplex to a radiative molecular exciton. Furthermore, the presence of non-radiative exciplex is confirmed by the photoluminescence decay profile and temperature dependent PL spectra. The luminance efficiency achieved for the modified Aryl-F8 polymer light-emitting diodes is ˜11 cd A-1 with an external quantum efficiency (EQE) of ˜4.5%, whereas it is 0.05 cd/A with an EQE of ˜0.025% for Aryl-F8. Almost two orders of higher efficiency is achieved due to the improved charge carrier balance from the random copolymer without compromising on the photoluminescence yield.

  17. Radiation detection device

    International Nuclear Information System (INIS)

    Peschmann, Kristian.

    1982-01-01

    A radiation detector suitable for use in computer tomography device has an ionization chamber which comprises a high voltage electrode, a collector electrode, a high voltage source having two terminals, one connected to the high voltage electrode, current measuring means having two terminals, one connected to the high voltage source and the other to the collector electrode, and an auxilliary electrode near and parallel to the entrance window of the device, having one adjacent to the high voltage electrode and the other adjacent but not connected to the collector electrode. The auxilliary electrode is connected to the high voltage source. In this way the electric field between the high voltage and collector electrodes is made homogeneous in the vicinity of the auxilliary electrode, improving the measuring speed of the detector

  18. Ultrafast coherent diffractive imaging of nanoparticles using X-ray free-electron laser radiation

    International Nuclear Information System (INIS)

    Kassemeyer, Stephan

    2014-01-01

    Coherent diffractive imaging with X-ray free-electron lasers (X-FEL) promises high-resolution structure determination of single microscopic particles without the need for crystallization. The diffraction signal of small samples can be very weak, a difficulty that can not be countered by merely increasing the number of photons because the sample would be damaged by a high absorbed radiation dose. Traditional X-ray crystallography avoids this problem by bringing many sample particles into a periodic arrangement, which amplifies the individual signals while distributing the absorbed dose. Depending on the sample, however, crystallization can be very difficult or even impossible. This thesis presents algorithms for a new imaging approach using X-FEL radiation that works with single, non-crystalline sample particles. X-FELs can deliver X-rays with a peak brilliance many orders of magnitude higher than conventional X-ray sources, compensating for their weak interaction cross sections. At the same time, FELs can produce ultra-short pulses down to a few femtoseconds. In this way it is possible to perform ultra-fast imaging, essentially ''freezing'' the atomic positions in time and terminating the imaging process before the sample is destroyed by the absorbed radiation. This thesis primarily focuses on the three-dimensional reconstruction of single (and not necessarily crystalline) particles using coherent diffractive imaging at X-FELs: in order to extract three-dimensional information from scattering data, two-dimensional diffraction patterns from many different viewing angles must be combined. Therefore, the diffraction signal of many identical sample copies in random orientations is measured. The main result of this work is a globally optimal algorithm that can recover the sample orientations solely based on the diffraction signal, enabling three-dimensional imaging for arbitrary samples. The problem of finding three-dimensional orientations is

  19. Radiation detection system

    Science.gov (United States)

    Riedel, Richard A [Knoxville, TN; Wintenberg, Alan L [Knoxville, TN; Clonts, Lloyd G [Knoxville, TN; Cooper, Ronald G [Oak Ridge, TN

    2012-02-14

    A preamplifier circuit for processing a signal provided by a radiation detector includes a transimpedance amplifier coupled to receive a current signal from a detector and generate a voltage signal at its output. A second amplification stage has an input coupled to an output of the transimpedance amplifier for providing an amplified voltage signal. Detector electronics include a preamplifier circuit having a first and second transimpedance amplifier coupled to receive a current signal from a first and second location on a detector, respectively, and generate a first and second voltage signal at respective outputs. A second amplification stage has an input coupled to an output of the transimpedance amplifiers for amplifying the first and said second voltage signals to provide first and second amplified voltage signals. A differential output stage is coupled to the second amplification stage for receiving the first and second amplified voltage signals and providing a pair of outputs from each of the first and second amplified voltage signals. Read out circuitry has an input coupled to receive both of the pair of outputs, the read out circuitry having structure for processing each of the pair of outputs, and providing a single digital output having a time-stamp therefrom.

  20. Ultrafast nanolaser device for detecting cancer in a single live cell.

    Energy Technology Data Exchange (ETDEWEB)

    Gourley, Paul Lee; McDonald, Anthony Eugene

    2007-11-01

    Emerging BioMicroNanotechnologies have the potential to provide accurate, realtime, high throughput screening of live tumor cells without invasive chemical reagents when coupled with ultrafast laser methods. These optically based methods are critical to advancing early detection, diagnosis, and treatment of disease. The first year goals of this project are to develop a laser-based imaging system integrated with an in- vitro, live-cell, micro-culture to study mammalian cells under controlled conditions. In the second year, the system will be used to elucidate the morphology and distribution of mitochondria in the normal cell respiration state and in the disease state for normal and disease states of the cell. In this work we designed and built an in-vitro, live-cell culture microsystem to study mammalian cells under controlled conditions of pH, temp, CO2, Ox, humidity, on engineered material surfaces. We demonstrated viability of cell culture in the microsystem by showing that cells retain healthy growth rates, exhibit normal morphology, and grow to confluence without blebbing or other adverse influences of the material surfaces. We also demonstrated the feasibility of integrating the culture microsystem with laser-imaging and performed nanolaser flow spectrocytometry to carry out analysis of the cells isolated mitochondria.

  1. Resonance detection of Moessbauer radiation

    International Nuclear Information System (INIS)

    Morozov, V.V.

    1985-01-01

    The resonance detection method as compared with the usual method of registering Moessbauer spectra has a number of advantages, one of which is the increase of resolution of the Moessbauer spectrum. The method is based on the modulation of a secondary radiation of a converter tuned in the resonance with the Moessbauer gamma-quantum source. The resonance detection method with account of supression, secondary radiation outgoing from the converter is investigated. The converter represents a substrate enriched by the Moessbauer isotope placed either inside the gas counter, or coupled with any other detecting device. Analytical expressions for Moessbauer spectrum parameters: effect, area and width of the spectral line are derived. It is shown that the joint application of usual and resonance detection methods for registering the Moessbauer spectrum allows one to determine parameters of the source, converter and the investigated absorber

  2. Advanced Ultrafast Spectroscopy for Chemical Detection of Nuclear Fuel Cycle Materials

    International Nuclear Information System (INIS)

    Villa-Aleman, E.; Houk, A.; Spencer, W.

    2017-01-01

    The development of new signatures and observables from processes related to proliferation activities are often related to the development of technologies. In our physical world, the intensity of observables is linearly related to the input drivers (light, current, voltage, etc.). Ultrafast lasers with high peak energies, opens the door to a new regime where the intensity of the observables is not necessarily linear with the laser energy. Potential nonlinear spectroscopic applications include chemical detection via remote sensing through filament generation, material characterization and processing, chemical reaction specificity, surface phenomena modifications, X-ray production, nuclear fusion, etc. The National Security Directorate laser laboratory is currently working to develop new tools for nonproliferation research with femtosecond and picosecond lasers. Prior to this project, we could only achieve laser energies in the 5 nano-Joule range, preventing the study of nonlinear phenomena. To advance our nonproliferation research into the nonlinear regime we require laser pulses in the milli-Joule (mJ) energy range. We have procured and installed a 35 fs-7 mJ laser, operating at one-kilohertz repetition rate, to investigate elemental and molecular detection of materials in the laboratory with potential applications in remote sensing. Advanced, nonlinear Raman techniques will be used to study materials of interest that are in a matrix of many materials and currently with these nonlinear techniques we can achieve greater than three orders of magnitude signal enhancement. This work studying nuclear fuel cycle materials with nonlinear spectroscopies will advance SRNL research capabilities and grow a core capability within the DOE complex.

  3. Advanced Ultrafast Spectroscopy for Chemical Detection of Nuclear Fuel Cycle Materials

    Energy Technology Data Exchange (ETDEWEB)

    Villa-Aleman, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Houk, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Spencer, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-29

    The development of new signatures and observables from processes related to proliferation activities are often related to the development of technologies. In our physical world, the intensity of observables is linearly related to the input drivers (light, current, voltage, etc.). Ultrafast lasers with high peak energies, opens the door to a new regime where the intensity of the observables is not necessarily linear with the laser energy. Potential nonlinear spectroscopic applications include chemical detection via remote sensing through filament generation, material characterization and processing, chemical reaction specificity, surface phenomena modifications, X-ray production, nuclear fusion, etc. The National Security Directorate laser laboratory is currently working to develop new tools for nonproliferation research with femtosecond and picosecond lasers. Prior to this project, we could only achieve laser energies in the 5 nano-Joule range, preventing the study of nonlinear phenomena. To advance our nonproliferation research into the nonlinear regime we require laser pulses in the milli-Joule (mJ) energy range. We have procured and installed a 35 fs-7 mJ laser, operating at one-kilohertz repetition rate, to investigate elemental and molecular detection of materials in the laboratory with potential applications in remote sensing. Advanced, nonlinear Raman techniques will be used to study materials of interest that are in a matrix of many materials and currently with these nonlinear techniques we can achieve greater than three orders of magnitude signal enhancement. This work studying nuclear fuel cycle materials with nonlinear spectroscopies will advance SRNL research capabilities and grow a core capability within the DOE complex.

  4. Analog electronics for radiation detection

    CERN Document Server

    2016-01-01

    Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

  5. Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high-intensity ultrasound.

    Science.gov (United States)

    Gateau, Jérôme; Aubry, Jean-François; Pernot, Mathieu; Fink, Mathias; Tanter, Mickaël

    2011-03-01

    The activation of natural gas nuclei to induce larger bubbles is possible using short ultrasonic excitations of high amplitude, and is required for ultrasound cavitation therapies. However, little is known about the distribution of nuclei in tissues. Therefore, the acoustic pressure level necessary to generate bubbles in a targeted zone and their exact location are currently difficult to predict. To monitor the initiation of cavitation activity, a novel all-ultrasound technique sensitive to single nucleation events is presented here. It is based on combined passive detection and ultrafast active imaging over a large volume using the same multi-element probe. Bubble nucleation was induced using a focused transducer (660 kHz, f-number = 1) driven by a high-power electric burst (up to 300 W) of one to two cycles. Detection was performed with a linear array (4 to 7 MHz) aligned with the single-element focal point. In vitro experiments in gelatin gel and muscular tissue are presented. The synchronized passive detection enabled radio-frequency data to be recorded, comprising high-frequency coherent wave fronts as signatures of the acoustic emissions linked to the activation of the nuclei. Active change detection images were obtained by subtracting echoes collected in the unnucleated medium. These indicated the appearance of stable cavitating regions. Because of the ultrafast frame rate, active detection occurred as quickly as 330 μs after the high-amplitude excitation and the dynamics of the induced regions were studied individually.

  6. Radiation Detection Computational Benchmark Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.; McDonald, Ben S.

    2013-09-24

    Modeling forms an important component of radiation detection development, allowing for testing of new detector designs, evaluation of existing equipment against a wide variety of potential threat sources, and assessing operation performance of radiation detection systems. This can, however, result in large and complex scenarios which are time consuming to model. A variety of approaches to radiation transport modeling exist with complementary strengths and weaknesses for different problems. This variety of approaches, and the development of promising new tools (such as ORNL’s ADVANTG) which combine benefits of multiple approaches, illustrates the need for a means of evaluating or comparing different techniques for radiation detection problems. This report presents a set of 9 benchmark problems for comparing different types of radiation transport calculations, identifying appropriate tools for classes of problems, and testing and guiding the development of new methods. The benchmarks were drawn primarily from existing or previous calculations with a preference for scenarios which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22. From a technical perspective, the benchmarks were chosen to span a range of difficulty and to include gamma transport, neutron transport, or both and represent different important physical processes and a range of sensitivity to angular or energy fidelity. Following benchmark identification, existing information about geometry, measurements, and previous calculations were assembled. Monte Carlo results (MCNP decks) were reviewed or created and re-run in order to attain accurate computational times and to verify agreement with experimental data, when present. Benchmark information was then conveyed to ORNL in order to guide testing and development of hybrid calculations. The results of those ADVANTG calculations were then sent to PNNL for

  7. Ionizing radiations, detection, dosimetry, spectrometry

    International Nuclear Information System (INIS)

    Blanc, D.

    1997-10-01

    A few works in French language are devoted to the detection of radiations. The purpose of this book is to fill a gap.The five first chapters are devoted to the properties of ionizing radiations (x rays, gamma rays, leptons, hadrons, nuclei) and to their interactions with matter. The way of classification of detectors is delicate and is studied in the chapter six. In the chapter seven are studied the statistics laws for counting and the spectrometry of particles is treated. The chapters eight to thirteen study the problems of ionization: charges transport in a gas, ionization chambers (theory of Boag), counters and proportional chambers, counters with 'streamers', chambers with derive, spark detectors, ionization chambers in liquid medium, Geiger-Mueller counters. The use of a luminous signal is the object of the chapters 14 to 16: conversion of a luminous signal in an electric signal, scintillators, use of the Cerenkov radiation. Then, we find the neutron detection with the chapter seventeen and the dosimetry of particles in the chapter eighteen. This book does not pretend to answer to specialists questions but can be useful to physicians, engineers or physics teachers. (N.C.)

  8. Cellular telephone-based radiation detection instrument

    Science.gov (United States)

    Craig, William W [Pittsburg, CA; Labov, Simon E [Berkeley, CA

    2011-06-14

    A network of radiation detection instruments, each having a small solid state radiation sensor module integrated into a cellular phone for providing radiation detection data and analysis directly to a user. The sensor module includes a solid-state crystal bonded to an ASIC readout providing a low cost, low power, light weight compact instrument to detect and measure radiation energies in the local ambient radiation field. In particular, the photon energy, time of event, and location of the detection instrument at the time of detection is recorded for real time transmission to a central data collection/analysis system. The collected data from the entire network of radiation detection instruments are combined by intelligent correlation/analysis algorithms which map the background radiation and detect, identify and track radiation anomalies in the region.

  9. Numerical simulation of terahertz generation and detection based on ultrafast photoconductive antennas

    Science.gov (United States)

    Chen, Long-chao; Fan, Wen-hui

    2011-08-01

    The numerical simulation of terahertz generation and detection in the interaction between femtosecond laser pulse and photoconductive material has been reported in this paper. The simulation model based on the Drude-Lorentz theory is used, and takes into account the phenomena that photo-generated electrons and holes are separated by the external bias field, which is screened by the space-charge field simultaneously. According to the numerical calculation, the terahertz time-domain waveforms and their Fourier-transformed spectra are presented under different conditions. The simulation results indicate that terahertz generation and detection properties of photoconductive antennas are largely influenced by three major factors, including photo-carriers' lifetime, laser pulse width and pump laser power. Finally, a simple model has been applied to simulate the detected terahertz pulses by photoconductive antennas with various photo-carriers' lifetimes, and the results show that the detected terahertz spectra are very different from the spectra radiated from the emitter.

  10. Time resolved 3D momentum imaging of ultrafast dynamics by coherent VUV-XUV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, F. P., E-mail: fpsturm@lbl.gov [Ultrafast X-Ray Science Lab, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Institut für Kernphysik, Universität Frankfurt, Max-von-Laue Str. 1, D-60438 Frankfurt (Germany); Wright, T. W.; Ray, D.; Zalyubovskaya, I.; Shivaram, N.; Slaughter, D. S.; Belkacem, A.; Weber, Th. [Ultrafast X-Ray Science Lab, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Ranitovic, P. [Ultrafast X-Ray Science Lab, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); ELI-ALPS, ELI-Hu Nkft, Dugonics ter 13, Szeged H6720 (Hungary)

    2016-06-15

    We present a new experimental setup for measuring ultrafast nuclear and electron dynamics of molecules after photo-excitation and ionization. We combine a high flux femtosecond vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) source with an internally cold molecular beam and a 3D momentum imaging particle spectrometer to measure electrons and ions in coincidence. We describe a variety of tools developed to perform pump-probe studies in the VUV-XUV spectrum and to modify and characterize the photon beam. First benchmark experiments are presented to demonstrate the capabilities of the system.

  11. 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.

  12. Physics and engineering of radiation detection

    CERN Document Server

    Ahmed, Syed Naeem

    2015-01-01

    Physics and Engineering of Radiation Detection presents an overview of the physics of radiation detection and its applications. It covers the origins and properties of different kinds of ionizing radiation, their detection and measurement, and the procedures used to protect people and the environment from their potentially harmful effects. The second edition is fully revised and provides the latest developments in detector technology and analyses software. Also, more material related to measurements in particle physics and a complete solutions manual have been added.

  13. Observing Structure and Motion in Molecules with Ultrafast Strong Field and Short Wavelength Laser Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bucksbaum, Philip H

    2011-04-13

    The term "molecular movie" has come to describe efforts to track and record Angstrom-scale coherent atomic and electronic motion in a molecule. The relevant time scales for this range cover several orders of magnitude, from sub-femtosecond motion associated with electron-electron correlations, to 100-fs internal vibrations, to multi-picosecond motion associated with the dispersion and quantum revivals of molecular reorientation. Conventional methods of cinematography do not work well in this ultrafast and ultrasmall regime, but stroboscopic "pump and probe" techniques can reveal this motion with high fidelity. This talk will describe some of the methods and recent progress in exciting and controlling this motion, using both laboratory lasers and the SLAC Linac Coherent Light Source x-ray free electron laser, and will further try to relate the date to the goal of molecular movies.

  14. Detecting radiation with your smartphone

    CERN Multimedia

    Agnes Szeberenyi

    2014-01-01

    The winners of the CERN EIROforum Prize in the European Union Competition for Young Scientists 2013 (EUCYS), Michał Gumiela and Rafał Tomasz Kozik from Poland, have just spent an exciting week exploring CERN from 1 to 5 September. The students visited several CERN experiments and facilities and had ample time to interact with scientists on how to improve their invention further.   Michał Gumiela (left) and Rafał Tomasz Kozik (right) with their CERN host, Sabrina El Yacoubi (middle) at the ALICE detector. Michał (21) and Rafał (20) both won a young physicist prize in Poland before submitting their work on “Studies of the applicability of CMOS and CCD sensors for detection of ionising radiation” to the EUCYS competition. “It all started with Fukushima,” recalls Michał. The high school students met in 2011 at a physics workshop, where they started discussing digital photos taken around the Fukushima nuclear plant after the radiation leak. &ldqu...

  15. Split energy level radiation detection

    International Nuclear Information System (INIS)

    Barnes, G.T.

    1986-01-01

    This patent describes an energy discriminating radiation detector comprising: (a) a first element comprising a first material of a kind which is preferentially responsive to penetrative radiation of a first energy range; (b) a second element comprising a second material different in kind from the first material and of a kind which is preferentially responsive to penetrative radiation of second energy range extending higher than the first energy range. The element is positioned to receive radiation which has penetrated through a portion of the first element; and (c) a filter of penetrative radiation interposed between the first and second elements

  16. Radiation Detection Center on the Front Lines

    International Nuclear Information System (INIS)

    Hazi, A

    2005-01-01

    Many of today's radiation detection tools were developed in the 1960s. For years, the Laboratory's expertise in radiation detection resided mostly within its nuclear test program. When nuclear testing was halted in the 1990s, many of Livermore's radiation detection experts were dispersed to other parts of the Laboratory, including the directorates of Chemistry and Materials Science (CMS); Physics and Advanced Technologies (PAT); Defense and Nuclear Technologies (DNT); and Nonproliferation, Arms Control, and International Security (NAI). The RDC-- was formed to maximize the benefit of radiation detection technologies being developed in 15 to 20 research and development (R and D) programs. These efforts involve more than 200 Laboratory employees across eight directorates, in areas that range from electronics to computer simulations. The RDC's primary focus is the detection, identification, and analysis of nuclear materials and weapons. A newly formed outreach program within the RDC-- is responsible for conducting radiation detection workshops and seminars across the country and for coordinating university student internships. Simon Labov, director of the RDC, says, ''Virtually all of the Laboratory's programs use radiation detection devices in some way. For example, DNT uses radiation detection to create radiographs for their work in stockpile stewardship and in diagnosing explosives; CMS uses it to develop technology for advancing the detection, diagnosis, and treatment of cancer; and the Energy and Environment Directorate uses radiation detection in the Marshall Islands to monitor the aftermath of nuclear testing in the Pacific. In the future, the National Ignition Facility will use radiation detection to probe laser targets and study shock dynamics.''

  17. Bayesian Methods for Radiation Detection and Dosimetry

    CERN Document Server

    Groer, Peter G

    2002-01-01

    We performed work in three areas: radiation detection, external and internal radiation dosimetry. In radiation detection we developed Bayesian techniques to estimate the net activity of high and low activity radioactive samples. These techniques have the advantage that the remaining uncertainty about the net activity is described by probability densities. Graphs of the densities show the uncertainty in pictorial form. Figure 1 below demonstrates this point. We applied stochastic processes for a method to obtain Bayesian estimates of 222Rn-daughter products from observed counting rates. In external radiation dosimetry we studied and developed Bayesian methods to estimate radiation doses to an individual with radiation induced chromosome aberrations. We analyzed chromosome aberrations after exposure to gammas and neutrons and developed a method for dose-estimation after criticality accidents. The research in internal radiation dosimetry focused on parameter estimation for compartmental models from observed comp...

  18. Graphene Field Effect Transistor for Radiation Detection

    Science.gov (United States)

    Li, Mary J. (Inventor); Chen, Zhihong (Inventor)

    2016-01-01

    The present invention relates to a graphene field effect transistor-based radiation sensor for use in a variety of radiation detection applications, including manned spaceflight missions. The sensing mechanism of the radiation sensor is based on the high sensitivity of graphene in the local change of electric field that can result from the interaction of ionizing radiation with a gated undoped silicon absorber serving as the supporting substrate in the graphene field effect transistor. The radiation sensor has low power and high sensitivity, a flexible structure, and a wide temperature range, and can be used in a variety of applications, particularly in space missions for human exploration.

  19. Radiation, ionization, and detection in nuclear medicine

    International Nuclear Information System (INIS)

    Gupta, Tapan K.

    2013-01-01

    Up-to-date information on a wide range of topics relating to radiation, ionization, and detection in nuclear medicine. In-depth coverage of basic radiophysics relating to diagnosis and therapy. Extensive discussion of instrumentation and radiation detectors. Detailed information on mathematical modelling of radiation detectors. Although our understanding of cancer has improved, the disease continues to be a leading cause of death across the world. The good news is that the recent technological developments in radiotherapy, radionuclide diagnostics and therapy, digital imaging systems, and detection technology have raised hope that cancer will in the future be combatted more efficiently and effectively. For this goal to be achieved, however, safe use of radionuclides and detailed knowledge of radiation sources are essential. Radiation, Ionization, and Detection in Nuclear Medicine addresses these subjects and related issues very clearly and elaborately and will serve as the definitive source of detailed information in the field. Individual chapters cover fundamental aspects of nuclear radiation, including dose and energy, sources, and shielding; the detection and measurement of radiation exposure, with detailed information on mathematical modelling; medical imaging; the different types of radiation detector and their working principles; basic principles of and experimental techniques for deposition of scintillating materials; device fabrication; the optical and electrical behaviors of radiation detectors; and the instrumentation used in nuclear medicine and its application. The book will be an invaluable source of information for academia, industry, practitioners, and researchers.

  20. Radiation, ionization, and detection in nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Tapan K. [Radiation Monitoring Devices Research, Nuclear Medicine, Watertown, MA (United States)

    2013-08-01

    Up-to-date information on a wide range of topics relating to radiation, ionization, and detection in nuclear medicine. In-depth coverage of basic radiophysics relating to diagnosis and therapy. Extensive discussion of instrumentation and radiation detectors. Detailed information on mathematical modelling of radiation detectors. Although our understanding of cancer has improved, the disease continues to be a leading cause of death across the world. The good news is that the recent technological developments in radiotherapy, radionuclide diagnostics and therapy, digital imaging systems, and detection technology have raised hope that cancer will in the future be combatted more efficiently and effectively. For this goal to be achieved, however, safe use of radionuclides and detailed knowledge of radiation sources are essential. Radiation, Ionization, and Detection in Nuclear Medicine addresses these subjects and related issues very clearly and elaborately and will serve as the definitive source of detailed information in the field. Individual chapters cover fundamental aspects of nuclear radiation, including dose and energy, sources, and shielding; the detection and measurement of radiation exposure, with detailed information on mathematical modelling; medical imaging; the different types of radiation detector and their working principles; basic principles of and experimental techniques for deposition of scintillating materials; device fabrication; the optical and electrical behaviors of radiation detectors; and the instrumentation used in nuclear medicine and its application. The book will be an invaluable source of information for academia, industry, practitioners, and researchers.

  1. Principles of nuclear radiation detection

    International Nuclear Information System (INIS)

    Eichholz, G.G.; Poston, J.W.

    1985-01-01

    This book covers the transistorization of equipment and provides an introduction into practice of semiconductor and thermoluminescent detectors. It discusses the principles of radiation detectors most widely used in nuclear technology, medical practice and radiation protection. It stresses the alternative detectors available and discusses practical considerations in choosing and setting up detector systems for actual use. Traditional materials, including semiconductors, TLD's and modern data handling facilities are covered

  2. Indirect detection of radiation sources through direct detection of radiolysis products

    Science.gov (United States)

    Farmer, Joseph C [Tracy, CA; Fischer, Larry E [Los Gatos, CA; Felter, Thomas E [Livermore, CA

    2010-04-20

    A system for indirectly detecting a radiation source by directly detecting radiolytic products. The radiation source emits radiation and the radiation produces the radiolytic products. A fluid is positioned to receive the radiation from the radiation source. When the fluid is irradiated, radiolytic products are produced. By directly detecting the radiolytic products, the radiation source is detected.

  3. Physics and engineering of radiation detection

    CERN Document Server

    Ahmed, Syed Naeem

    2007-01-01

    Physics and Engineering of Radiation Detection presents an overview of basic physics of radiation and its applications and covers the origins and properties of different kinds of ionizing radiation, their detection and measurement, and the procedures used to protect people and the environment from their potentially harmful effects. Covering both the basic physics of radiation and its applications, it will provide an up-to-date and coherent account of the origins and properties of the different kinds of ionizing radiation, and their detection and measurement. This book will illustrate the basic physical principles with an abundance of practical, worked-out examples, numerical problems, real world applications, and data, including biological effects, radon, risk assessment, and statistics.

  4. Asymmetric-detection time-stretch optical microscopy (ATOM) for ultrafast high-contrast cellular imaging in flow

    Science.gov (United States)

    Wong, Terence T. W.; Lau, Andy K. S.; Ho, Kenneth K. Y.; Tang, Matthew Y. H.; Robles, Joseph D. F.; Wei, Xiaoming; Chan, Antony C. S.; Tang, Anson H. L.; Lam, Edmund Y.; Wong, Kenneth K. Y.; Chan, Godfrey C. F.; Shum, Ho Cheung; Tsia, Kevin K.

    2014-01-01

    Accelerating imaging speed in optical microscopy is often realized at the expense of image contrast, image resolution, and detection sensitivity – a common predicament for advancing high-speed and high-throughput cellular imaging. We here demonstrate a new imaging approach, called asymmetric-detection time-stretch optical microscopy (ATOM), which can deliver ultrafast label-free high-contrast flow imaging with well delineated cellular morphological resolution and in-line optical image amplification to overcome the compromised imaging sensitivity at high speed. We show that ATOM can separately reveal the enhanced phase-gradient and absorption contrast in microfluidic live-cell imaging at a flow speed as high as ~10 m/s, corresponding to an imaging throughput of ~100,000 cells/sec. ATOM could thus be the enabling platform to meet the pressing need for intercalating optical microscopy in cellular assay, e.g. imaging flow cytometry – permitting high-throughput access to the morphological information of the individual cells simultaneously with a multitude of parameters obtained in the standard assay. PMID:24413677

  5. Pulse X-radiation in flaw detection

    International Nuclear Information System (INIS)

    Vavilov, S.P.; Gorbunov, V.I.

    1985-01-01

    Principles of physical and engineering application of pulse X-radiation (PXR) of micro- and nanosecond duration for nondestructive testing of processes, materials and devices are given. Methods and devices, aimed at generating X-ray pulses, as well as their radiation and flow detection characteristics, and testing methods by means of PXR are considered

  6. Device for detecting ionizing radiation

    International Nuclear Information System (INIS)

    Anatychuk, L.I.; Kharitonov, J.P.; Kusniruk, V.F.; Meir, V.A.; Melnik, A.P.; Ponomarev, V.S.; Skakodub, V.A.; Sokolov, A.D.; Subbotin, V.G.; Zhukovsky, A.N.

    1980-01-01

    The present invention relates to ionizing radiation sensors, and , more particularly, to semiconductor spectrometers with thermoelectric cooling, and can most advantageously be used in mineral raw material exploration and evaluation under field conditions. The spectrometer comprises a vacuum chamber with an entrance window for passing the radiation therethrough. The vacuum chamber accommodates a thermoelectric cooler formed by a set of peltier elements. A heat conducting plate is mounted on the cold side of the thermoelectric cooler, and its hot side is provided with a radiator. Mounted on the heat conducting plate are sets of peltier elements, integral with the thermoelectric cooler and independent of one another. The peltier elements of these sets are stacked so as to develop the minimum temperature conditions on one set carrying a semiconductor detector and to provide the maximum refrigeration capacity conditions on the other set provided with the field-effect transistor mounted thereon

  7. Assembly for detecting penetrating radiation

    International Nuclear Information System (INIS)

    Froggatt, R.J.

    1978-01-01

    The detector to pick up the X-rays emitted from a cross-sectional plane of a patient (computer tomography) consists of a cadmium sulfide monocrystal, an ultrasonic transmitter, and an ultrasonic receiver. The X-rays hit the crystal at right angle to a d.c. drift field applied on the electrons generated by the X-radiation. The ultrasonic field may strike the crystal parallel or at some angle with respect to this d.c. drift field. The energefically changed sound wave picked up by the ultrasonic receiver respectively its amplitude is a measure for the intensity of the X-radiation. (DG) [de

  8. Radiation Detection for Homeland Security Applications

    Science.gov (United States)

    Ely, James

    2008-05-01

    In the past twenty years or so, there have been significant changes in the strategy and applications for homeland security. Recently there have been significant at deterring and interdicting terrorists and associated organizations. This is a shift in the normal paradigm of deterrence and surveillance of a nation and the `conventional' methods of warfare to the `unconventional' means that terrorist organizations resort to. With that shift comes the responsibility to monitor international borders for weapons of mass destruction, including radiological weapons. As a result, countries around the world are deploying radiation detection instrumentation to interdict the illegal shipment of radioactive material crossing international borders. These efforts include deployments at land, rail, air, and sea ports of entry in the US and in European and Asian countries. Radioactive signatures of concern include radiation dispersal devices (RDD), nuclear warheads, and special nuclear material (SNM). Radiation portal monitors (RPMs) are used as the main screening tool for vehicles and cargo at borders, supplemented by handheld detectors, personal radiation detectors, and x-ray imaging systems. This talk will present an overview of radiation detection equipment with emphasis on radiation portal monitors. In the US, the deployment of radiation detection equipment is being coordinated by the Domestic Nuclear Detection Office within the Department of Homeland Security, and a brief summary of the program will be covered. Challenges with current generation systems will be discussed as well as areas of investigation and opportunities for improvements. The next generation of radiation portal monitors is being produced under the Advanced Spectroscopic Portal program and will be available for deployment in the near future. Additional technologies, from commercially available to experimental, that provide additional information for radiation screening, such as density imaging equipment, will

  9. Silicon solid state devices and radiation detection

    CERN Document Server

    Leroy, Claude

    2012-01-01

    This book addresses the fundamental principles of interaction between radiation and matter, the principles of working and the operation of particle detectors based on silicon solid state devices. It covers a broad scope with respect to the fields of application of radiation detectors based on silicon solid state devices from low to high energy physics experiments including in outer space and in the medical environment. This book covers stateof- the-art detection techniques in the use of radiation detectors based on silicon solid state devices and their readout electronics, including the latest developments on pixelated silicon radiation detector and their application.

  10. Labor security in radiation flaw detection

    International Nuclear Information System (INIS)

    Margulis, U.Ya.; Chistov, E.D.; Partolin, O.F.; Pertsov, V.A.; Momzhiev, B.N.; Sprygaev, I.F.

    1986-01-01

    Problems of ensuring safe labour conditions in radiation flaw detection are considered. Methods for ionizing radiation protection are given calculating techniques for shielding flaw detectors and stationary structures are presented as well. Safe methods of nondestructive testing of items under field conditions, in a shop and special laboratories using gamma- and X-ray flaw detectors, betatrons, electron accelerators are described. Attention is paid to the principles of radiation factor stantardization as well as radiation monitoring. Analysis of accidents and recommendations on their prevention and liquidation of accidental consequences are given

  11. Detection and measurement of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    All detection or measurement of radiation rests in the possibility of recognizing the interactions of radiation with matter. When radiation passes through any kind of material medium, all or a portion of its energy is transferred to this medium. This transferred energy produces an effect in the medium. In principle, the detection of radiation is based on the appearance and the observation of this effect. In theory, all of the effects produced by radiation may be used in detecting it: in practice, the effects most commonly employed are: (1) ionization of gases (gas detectors), or of some chemical substance which is transformed by radiation (photographic or chemical dosimeters); (2) excitations in scintillators or semiconductors (scintillation counters, semiconductor counters); (3) creation of structural defects through the passage of radiation (transparent thermoluminescent and radioluminescent detectors); and (4) raising of the temperature (calorimeters). This study evaluates in detail, instruments based on the ionization of gases and the production of luminescence. In addition, the authors summarize instruments which depend on other forms of interaction, used in radiation medicine and hygiene (radiology, nuclear medicine)

  12. Electrets for beta radiation detection

    International Nuclear Information System (INIS)

    Campos, L.L.; Caldas, L.V.E.; Mascarenhas, S.

    1983-01-01

    Electret dosimetry has been reviewed by Gross. A cylindrical electret ionization-chamber type dosimeter has been studied for X and gamma rays and neutrons. The principle of the dosimeter is electret charge compensation due to ionization in the chamber volume. Electret ionization chambers can be designed with one or more electrets and in various shapes. This study is concerned with a simple system, similar to a cylindrical ionization chamber (sensitive volume: 3,5 cm 3 ) using teflon electrets. Aluminum and lucite were used as wall-materials. Other experiences were performed using chambers without wall, i.e., without defined sensitive volume. The teflon electrets were obtained by Corona discharge in the gas surrounding them. The measurement of the electret charge was made by induction using a co-axial insulated metal chamber connected to an electrometer Keithley 610C. By measuring the charge before and after irradiation it is possible to obtain a calibration curve: charge (Q) versus absorbed dose (D) for the dosimeter. The irradiation setup used was the Beta Secondary Standard System of IPEN calibration laboratory with four beta sources: 90 Sr 90 Y (74 and 1850 MBq), 204 Tl (18,5 MBq) and 147 Pm (518 MBq). In some cases a 85 Kr source was also used. The electrets were tested in different radiation field geometries: electret axis parallel and perpendicular to the field. In conclusion, depending on the wall material and radiation field geometry, the teflon electret detector can be used for different dose interval determinations, using beta radiation

  13. Adaptive search and detection of laser radiation

    International Nuclear Information System (INIS)

    Efendiev, F.A.; Kasimova, F.I.

    2008-01-01

    Formation of cosmic optical line connected with the solving of difficult problems, among which stand out spatial search task, detection and target tracking. Indeed, the main advantage of systems of the optical diapason, high radiation direction leads to a challenging task of entering in communication, consisting in mutual targeting antenna receiving and transmitting systems. Algorithm detection, obtained by solving the corresponding statistical optimal detection test synthesis tasks detector determines the structure and quality of his work which depend on the average characteristics of the signal and the background radiation of the thermal noise require full priori certainty about the conditions of observation. Algorithm of the optimal detector of laser light modulated on a sub carrier frequency of intensity assumes a priori known intensity and efficiency background radiation and internal noise power photo detector

  14. Origin, characteristics and detection of nuclear radiation

    International Nuclear Information System (INIS)

    Goettel, K.

    1975-06-01

    The report is an introduction into the physical principles of radiation protection. After a brief summary of the most significant experimental results and data on the atomic structure of the matter and after explaining the principles of atomic and nuclear structure, radioactive decay and its laws are dealt with. This is followed by a representation of the characteristics of nuclear radiation, its interaction with the matter as well as the biological effects. After a description of the measurement units for radioactivity and doses the most inportant methods for radiation detection and the principles of how detectors function are explained. (ORU/LN) [de

  15. 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.)

  16. Bayesian Methods for Radiation Detection and Dosimetry

    International Nuclear Information System (INIS)

    Peter G. Groer

    2002-01-01

    We performed work in three areas: radiation detection, external and internal radiation dosimetry. In radiation detection we developed Bayesian techniques to estimate the net activity of high and low activity radioactive samples. These techniques have the advantage that the remaining uncertainty about the net activity is described by probability densities. Graphs of the densities show the uncertainty in pictorial form. Figure 1 below demonstrates this point. We applied stochastic processes for a method to obtain Bayesian estimates of 222Rn-daughter products from observed counting rates. In external radiation dosimetry we studied and developed Bayesian methods to estimate radiation doses to an individual with radiation induced chromosome aberrations. We analyzed chromosome aberrations after exposure to gammas and neutrons and developed a method for dose-estimation after criticality accidents. The research in internal radiation dosimetry focused on parameter estimation for compartmental models from observed compartmental activities. From the estimated probability densities of the model parameters we were able to derive the densities for compartmental activities for a two compartment catenary model at different times. We also calculated the average activities and their standard deviation for a simple two compartment model

  17. Detection of food treated with ionizing radiation

    International Nuclear Information System (INIS)

    Delincee, H.

    1998-01-01

    Treatment of food with ionizing energy-'food irradiation'- is finally becoming reality in many countries. The benefits include an improvement in food hygiene, spoilage reduction and extension of shelf-life. Although properly irradiated food is safe and wholesome, consumers should be able to make their own free choice between irradiated and non-irradiated food. For this purpose labelling is indispensable. In order to check compliance with existing regulations, detection of radiation treatment by analysing the food itself is highly desirable. Significant progress has been made in recent years in developing analytical detection methods utilizing changes in food originating from the radiation treatment

  18. Ultra-Fast Low Concentration Detection of Candida Pathogens Utilizing High Resolution Micropore Chips

    OpenAIRE

    Mulero, Rafael; Lee, Dong Heun; Kutzler, Michele A.; Jacobson, Jeffrey M.; Kim, Min Jun

    2009-01-01

    Although Candida species are the fourth most common cause of nosocomial blood stream infections in the United States, early diagnostic tools for invasive candidemia are lacking. Due to an increasing rate of candidemia, a new screening system is needed to detect the Candida species in a timely manner. Here we describe a novel method of detection using a solid-state micro-scale pore similar to the operational principles of a Coulter counter. With a steady electrolyte current flowing through the...

  19. 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)

  20. Sensitive and ultra-fast species detection using pulsed cavity ringdown spectroscopy

    KAUST Repository

    Alquaity, Awad; Es-sebbar, Et-touhami; Farooq, Aamir

    2015-01-01

    of ethylene in the mid-IR region near 949.47 cm-1. Each ringdown measurement is completed in less than 1 μs and the time period between successive pulses is 10 μs. The high sensitivity diagnostic has a noise-equivalent detection limit of 1.08 x 10-5 cm-1 which

  1. Precision of quantum tomographic detection of radiation

    Energy Technology Data Exchange (ETDEWEB)

    D' Ariano, G.M. (Dipartimento di Fisica ' ' Alessandro Volta' ' , Via A. Bassi 6, I-27100, Pavia (Italy) Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Via A. Bassi 6, I-27100, Pavia (Italy)); Macchiavello, Chiara (Dipartimento di Fisica ' ' Alessandro Volta' ' , Via A. Bassi 6, I-27100, Pavia (Italy)); Paris, M.G.A. (Dipartimento di Fisica ' ' Alessandro Volta' ' , Via A. Bassi 6, I-27100, Pavia (Italy))

    1994-11-21

    Homodyne tomography provides an experimental technique for reconstructing the density matrix of the radiation field. Here we analyze the tomographic precision in recovering observables like the photon number, the quadrature, and the phase. We show that tomographic reconstruction, despite providing a complete characterization of the state of the field, is generally much less efficient than conventional detection techniques. ((orig.))

  2. Precision of quantum tomographic detection of radiation

    International Nuclear Information System (INIS)

    D'Ariano, G.M.; Macchiavello, Chiara; Paris, M.G.A.

    1994-01-01

    Homodyne tomography provides an experimental technique for reconstructing the density matrix of the radiation field. Here we analyze the tomographic precision in recovering observables like the photon number, the quadrature, and the phase. We show that tomographic reconstruction, despite providing a complete characterization of the state of the field, is generally much less efficient than conventional detection techniques. ((orig.))

  3. Nuclear Forensics and Radiochemistry: Radiation Detection

    Energy Technology Data Exchange (ETDEWEB)

    Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-08

    Radiation detection is necessary for isotope identification and assay in nuclear forensic applications. The principles of operation of gas proportional counters, scintillation counters, germanium and silicon semiconductor counters will be presented. Methods for calibration and potential pitfalls in isotope quantification will be described.

  4. Nuclear Forensics and Radiochemistry: Radiation Detection

    International Nuclear Information System (INIS)

    Rundberg, Robert S.

    2017-01-01

    Radiation detection is necessary for isotope identification and assay in nuclear forensic applications. The principles of operation of gas proportional counters, scintillation counters, germanium and silicon semiconductor counters will be presented. Methods for calibration and potential pitfalls in isotope quantification will be described.

  5. Composite scintillators for detection of ionizing radiation

    Science.gov (United States)

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

    2010-12-28

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

  6. Detection of electromagnetic radiation using nonlinear materials

    Science.gov (United States)

    Hwang, Harold Y.; Liu, Mengkun; Averitt, Richard D.; Nelson, Keith A.; Sternbach, Aaron; Fan, Kebin

    2016-06-14

    An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

  7. Ultrafast detection in particle physics and positron emission tomography using SiPMs

    Science.gov (United States)

    Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.

    2017-12-01

    Silicon photomultiplier (SiPM) photodetectors perform well in many particle and medical physics applications, especially where good efficiency, insensitivity to magnetic field and precise timing are required. In Cherenkov time-of-flight positron emission tomography the requirements for photodetector performance are especially high. On average only a couple of photons are available for detection and the best possible timing resolution is needed. Using SiPMs as photodetectors enables good detection efficiency, but the large sensitive area devices needed have somewhat limited time resolution for single photons. We have observed an additional degradation of the timing at very low light intensities due to delayed events in distribution of signals resulting from multiple fired micro cells. In this work we present the timing properties of AdvanSiD ASD-NUV3S-P-40 SiPM at single photon level picosecond laser illumination and a simple modification of the time-walk correction algorithm, that resulted in reduced degradation of timing resolution due to the delayed events.

  8. Radiation sensitive area detection device and method

    Science.gov (United States)

    Carter, Daniel C. (Inventor); Hecht, Diana L. (Inventor); Witherow, William K. (Inventor)

    1991-01-01

    A radiation sensitive area detection device for use in conjunction with an X ray, ultraviolet or other radiation source is provided which comprises a phosphor containing film which releases a stored diffraction pattern image in response to incoming light or other electromagnetic wave. A light source such as a helium-neon laser, an optical fiber capable of directing light from the laser source onto the phosphor film and also capable of channelling the fluoresced light from the phosphor film to an integrating sphere which directs the light to a signal processing means including a light receiving means such as a photomultiplier tube. The signal processing means allows translation of the fluoresced light in order to detect the original pattern caused by the diffraction of the radiation by the original sample. The optical fiber is retained directly in front of the phosphor screen by a thin metal holder which moves up and down across the phosphor screen and which features a replaceable pinhole which allows easy adjustment of the resolution of the light projected onto the phosphor film. The device produces near real time images with high spatial resolution and without the distortion that accompanies prior art devices employing photomultiplier tubes. A method is also provided for carrying out radiation area detection using the device of the invention.

  9. Ultrafast MR Imaging in Pediatric Neuroradiology

    International Nuclear Information System (INIS)

    Singh, R.K.; Smith, J.T.; Wilkinson, I.D.; Griffiths, P.D.

    2003-01-01

    Purpose: To compare the diagnostic information obtained from ultrafast MR imaging with standard MR imaging techniques in pediatric neuroradiology. The goal was to judge whether ultrafast methods can be used to replace standard methods and reduce the need for sedation or general anesthesia as a result of the considerably shorter scan times. Material and Methods: Our prospective study involved 125 patients. Routine clinical imaging was performed along with two ultrafast methods. Single shot fast spin echo (SSFSE) was used to give T2-weighted images and an echo planar imaging (EPI) sequence to provide a T1-weighted images. The ultrafast images were presented to an experienced neuro radiologist who was also given the information present on the initial referral card. These reports based on the ultrafast images were then compared with the formal radiologic report made solely on the basis of the standard imaging. Results: The overall sensitivity and specificity for ultrafast imaging when compared to the reference standard were 78% and 98% with positive and negative predictive values of 98% and 76%. Pathologies characterized by small areas of subtle T2 prolongation were difficult or impossible to see on the ultrafast images but otherwise they provided reliable information. Conclusions: This paper demonstrates that ultrafast MR imaging can diagnose many pediatric intracranial abnormalities as well as standard methods. Anatomic resolution limits its capacity to define subtle developmental anomalies and contrast resolution limitations of the ultrafast methods reduce the detection of pathology characterized by subtle T2 prolongation

  10. Measuring element for the detection and determination of radiation doses of gamma radiation and neutrons

    International Nuclear Information System (INIS)

    Jahn, W.; Piesch, E.

    1975-01-01

    A measuring element detects and proves both gamma and neutron radiation. The element includes a photoluminescent material which stores gamma radiation and particles of arsenic and phosphorus embedded in the photoluminescent material for detecting neutron radiation. (U.S.)

  11. Waveshifters and Scintillators for Ionizing Radiation Detection

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  12. 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.

  13. Ultrafast state detection and 2D ion crystals in a Paul trap

    Science.gov (United States)

    Ip, Michael; Ransford, Anthony; Campbell, Wesley

    2016-05-01

    Projective readout of quantum information stored in atomic qubits typically uses state-dependent CW laser-induced fluorescence. This method requires an often sophisticated imaging system to spatially filter out the background CW laser light. We present an alternative approach that instead uses simple pulse sequences from a mode-locked laser to affect the same state-dependent excitations in less than 1 ns. The resulting atomic fluorescence occurs in the dark, allowing the placement of non-imaging detectors right next to the atom to improve the qubit state detection efficiency and speed. We also study 2D Coulomb crystals of atomic ions in an oblate Paul trap. We find that crystals with hundreds of ions can be held in the trap, potentially offering an alternative to the use of Penning traps for the quantum simulation of 2D lattice spin models. We discuss the classical physics of these crystals and the metastable states that are supported in 2D. This work is supported by the US Army Research Office.

  14. Plasmonically enhanced thermomechanical detection of infrared radiation.

    Science.gov (United States)

    Yi, Fei; Zhu, Hai; Reed, Jason C; Cubukcu, Ertugrul

    2013-04-10

    Nanoplasmonics has been an attractive area of research due to its ability to localize and manipulate freely propagating radiation on the nanometer scale for strong light-matter interactions. Meanwhile, nanomechanics has set records in the sensing of mass, force, and displacement. In this work, we report efficient coupling between infrared radiation and nanomechanical resonators through nanoantenna enhanced thermoplasmonic effects. Using efficient conversion of electromagnetic energy to mechanical energy in this plasmo-thermomechanical platform with a nanoslot plasmonic absorber integrated directly on a nanobeam mechanical resonator, we demonstrate room-temperature detection of nanowatt level power fluctuations in infrared radiation. We expect our approach, which combines nanoplasmonics with nanomechanical resonators, to lead to optically controlled nanomechanical systems enabling unprecedented functionality in biomolecular and toxic gas sensing and on-chip mass spectroscopy.

  15. 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)

  16. Detection of radiation processing in onions

    International Nuclear Information System (INIS)

    Duchacek, V.

    1985-01-01

    Two breeds of onions were used for irradiation. Both breeds were divided into two parts - the first was irradiated with a dose of 80 Gy and the second served as a control. The two parts were stored under the same conditions. Conductometry, liquid chromatography and spectrophotometry were used for detecting the radiation processing of the onions. Only from the spectrophotometric determination of 2-desoxysaccharides it was possible to safely distinguish irradiated onions from non-irradiated controls throughout storage time. (E.S.)

  17. Nuclear radiation detection by a variband semiconductor

    International Nuclear Information System (INIS)

    Volkov, A.S.

    1981-01-01

    Possibilities of using a variband semiconductor for detecting nuclear radiations are considered. It is shown that the variaband quasielectric field effectively collects charges induced by a nuclear particle only at a small mean free path in the semiconductor (up to 100 μm), the luminescence spectrum of the variband semiconductor when a nuclear particle gets into it, in principle, permits to determine both the energy and mean free path in the semiconductor (even at large mean free paths) [ru

  18. Multichannel Digital Emulator of Radiation Detection Systems

    International Nuclear Information System (INIS)

    Abba, A.; Caponio, F.; Geraci, A.

    2013-06-01

    A digital system for emulating in real time signals from generic setups for radiation detection is presented. The instrument is not a pulse generator of recorded shapes but a synthesizer of random pulses compliant to programmable statistics for energy and occurrence time. Completely programmable procedures for emulation of noise, disturbances and reference level variation can be implemented. The instrument has been realized and fully tested. (authors)

  19. Ultrafast biophotonics

    CERN Document Server

    Vasa, P

    2016-01-01

    This book presents emerging contemporary optical techniques of ultrafast science which have opened entirely new vistas for probing biological entities and processes. The spectrum reaches from time-resolved imaging and multiphoton microscopy to cancer therapy and studies of DNA damage. The book displays interdisciplinary research at the interface of physics and biology. Emerging topics on the horizon are also discussed, like the use of squeezed light, frequency combs and terahertz imaging as the possibility of mimicking biological systems. The book is written in a manner to make it readily accessible to researchers, postgraduate biologists, chemists, engineers, and physicists and students of optics, biomedical optics, photonics and biotechnology.

  20. PREFACE: Ultrafast biophotonics Ultrafast biophotonics

    Science.gov (United States)

    Gu, Min; Reid, Derryck; Ben-Yakar, Adela

    2010-08-01

    The use of light to explore biology can be traced to the first observations of tissue made with early microscopes in the mid-seventeenth century, and has today evolved into the discipline which we now know as biophotonics. This field encompasses a diverse range of activities, each of which shares the common theme of exploiting the interaction of light with biological material. With the rapid advancement of ultrafast optical technologies over the last few decades, ultrafast lasers have increasingly found applications in biophotonics, to the extent that the distinctive new field of ultrafast biophotonics has now emerged, where robust turnkey ultrafast laser systems are facilitating cutting-edge studies in the life sciences to take place in everyday laboratories. The broad spectral bandwidths, precision timing resolution, low coherence and high peak powers of ultrafast optical pulses provide unique opportunities for imaging and manipulating biological systems. Time-resolved studies of bio-molecular dynamics exploit the short pulse durations from such lasers, while other applications such as optical coherence tomography benefit from the broad optical bandwidths possible by using super-continuum generation and additionally allowing for high speed imaging with speeds as high as 47 000 scans per second. Continuing progress in laser-system technology is accelerating the adoption of ultrafast techniques across the life sciences, both in research laboratories and in clinical applications, such as laser-assisted in situ keratomileusis (LASIK) eye surgery. Revolutionizing the field of optical microscopy, two-photon excitation fluorescence (TPEF) microscopy has enabled higher spatial resolution with improved depth penetration into biological specimens. Advantages of this nonlinear optical process include: reduced photo-interactions, allowing for extensive imaging time periods; simultaneously exciting multiple fluorescent molecules with only one excitation wavelength; and

  1. Radiation detection technology assessment program (RADTAP)

    International Nuclear Information System (INIS)

    Smith, D.E.

    1998-01-01

    The U.S. Customs Service and the U.S. Department of Energy (DOE) conducted a technical and operational assessment of gamma ray radiation detection equipment during the period May 5-16, 1997 at a testing facility in North Carolina. The effort was entitled, ''Radiation Detection Technology Assessment Program (RADTAP)'', and was conducted for the purpose of assessing the applicability, sensitivity and robustness of a diverse suite of gamma ray detection and identification equipment for possible use by Customs and other law enforcement agencies. Thirteen companies entered 25 instruments into the assessment program. All detection equipment entered had to exhibit a minimum sensitivity of 20 micro-R per hour (background included) from a Cesium-137 point source. Isotope identifying spectrometers entered were man portable and operable at room temperature with read-out that could be interpreted by non-technical personnel. Radioactive sources used in the assessment included special nuclear material, industrial and health isotopes. Evaluators included Customs inspectors and technical experts from DOE and Customs. No conclusions or recommendations were issued based on the quantitative and qualitative test results, however, the results of the program provided law enforcement agencies with the necessary data to select equipment that best meets their operational needs and budgets. (author)

  2. Bubble Radiation Detection: Current and Future Capability

    International Nuclear Information System (INIS)

    Peurrung, A.J.; Craig, R.A.

    1999-01-01

    Despite a number of noteworthy achievements in other fields, superheated droplet detectors (SDDs) and bubble chambers (BCs) have not been used for nuclear nonproliferation and arms control. This report examines these two radiation-detection technologies in detail and answers the question of how they can be or should be ''adapted'' for use in national security applications. These technologies involve closely related approaches to radiation detection in which an energetic charged particle deposits sufficient energy to initiate the process of bubble nucleation in a superheated fluid. These detectors offer complete gamma-ray insensitivity when used to detect neutrons. They also provide controllable neutron-energy thresholds and excellent position resolution. SDDs are extraordinarily simple and inexpensive. BCs offer the promise of very high efficiency (∼75%). A notable drawback for both technologies is temperature sensitivity. As a result of this problem, the temperature must be controlled whenever high accuracy is required, or harsh environmental conditions are encountered. The primary findings of this work are listed and briefly summarized below: (1) SDDs are ready to function as electronics-free neutron detectors on demand for arms-control applications. The elimination of electronics at the weapon's location greatly eases the negotiability of radiation-detection technologies in general. (2) As a result of their high efficiency and sharp energy threshold, current BCs are almost ready for use in the development of a next-generation active assay system. Development of an instrument based on appropriately safe materials is warranted. (3) Both kinds of bubble detectors are ready for use whenever very high gamma-ray fields must be confronted. Spent fuel MPC and A is a good example where this need presents itself. (4) Both kinds of bubble detectors have the potential to function as low-cost replacements for conventional neutron detectors such as 3 He tubes. For SDDs

  3. Cellular telephone-based wide-area radiation detection network

    Science.gov (United States)

    Craig, William W [Pittsburg, CA; Labov, Simon E [Berkeley, CA

    2009-06-09

    A network of radiation detection instruments, each having a small solid state radiation sensor module integrated into a cellular phone for providing radiation detection data and analysis directly to a user. The sensor module includes a solid-state crystal bonded to an ASIC readout providing a low cost, low power, light weight compact instrument to detect and measure radiation energies in the local ambient radiation field. In particular, the photon energy, time of event, and location of the detection instrument at the time of detection is recorded for real time transmission to a central data collection/analysis system. The collected data from the entire network of radiation detection instruments are combined by intelligent correlation/analysis algorithms which map the background radiation and detect, identify and track radiation anomalies in the region.

  4. Measurements with an ultrafast scanning tunnelling microscope on photoexcited semiconductor layers

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Jensen, Jacob Riis; Hvam, Jørn Märcher

    1998-01-01

    Summary form only given. We demonstrate the use of a ultrafast scanning tunnelling microscopes (USTM) for detecting laser-induced field transients on semiconductor layers. In principle, the instrument can detect transient field changes thus far observed as far-field THz radiation in the near......-field regime and resolve small signal sources. For photoexcited low temperature (LT) GaAs we can explain the signal by a diffusion current driven by the laser-induced carrier density gradient...

  5. Detecting solar chameleons through radiation pressure

    CERN Document Server

    Baum, Sebastian

    2014-01-01

    Light scalar fields can drive accelerated expansion of the universe. Hence, scalars are obvious dark energy candidates. To make these models compatible with test of General Relativity in the solar system and fifth force searches on earth, one needs to screen them. One possibility is the chameleon mechanism, which renders an effective mass depending on the local energy density. If chameleons exist, they can be produced in the sun and detected on earth through their radiation pressure. We calculate the solar chameleon spectrum and the sensitivity of an experiment to be carried out at CAST, CERN, utilizing a radiation pressure sensor currently under development at INFN, Trieste. We show that such an experiment will be sensitive to a wide range of model parameters and signifies a pioneering effort searching for chameleons in unprobed paramterspace.

  6. Pencil-shaped radiation detection ionization chamber

    International Nuclear Information System (INIS)

    Suzuki, A.

    1979-01-01

    A radiation detection ionization chamber is described. It consists of an elongated cylindrical pencil-shaped tubing forming an outer wall of the chamber and a center electrode disposed along the major axis of the tubing. The length of the chamber is substantially greater than the diameter. A cable connecting portion at one end of the chamber is provided for connecting the chamber to a triaxial cable. An end support portion is connected at the other end of the chamber for supporting and tensioning the center electrode. 17 claims

  7. Detecting solar chameleons through radiation pressure

    CERN Document Server

    Baum, S.; Hoffmann, D.H.H.; Karuza, M.; Semertzidis, Y.K.; Upadhye, A.; Zioutas, K.

    2014-10-24

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and "fifth force" searches on Earth, one needs to screen them. One possibility is the so-called "chameleon" mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary re...

  8. 2D heterodyne-detected sum frequency generation study on the ultrafast vibrational dynamics of H{sub 2}O and HOD water at charged interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Ken-ichi; Singh, Prashant C. [Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Nihonyanagi, Satoshi; Tahara, Tahei, E-mail: tahei@riken.jp [Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamaguchi, Shoichi [Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Department of Applied Chemistry, Saitama University, 255 Shimo-Okubo, Saitama 338-8570 (Japan)

    2015-06-07

    Two-dimensional heterodyne-detected vibrational sum-frequency generation (2D HD-VSFG) spectroscopy is applied to study the ultrafast vibrational dynamics of water at positively charged aqueous interfaces, and 2D HD-VSFG spectra of cetyltrimethylammonium bromide (CTAB)/water interfaces in the whole hydrogen-bonded OH stretch region (3000 cm{sup −1} ≤ ω{sub pump} ≤ 3600 cm{sup −1}) are measured. 2D HD-VSFG spectrum of the CTAB/isotopically diluted water (HOD-D{sub 2}O) interface exhibits a diagonally elongated bleaching lobe immediately after excitation, which becomes round with a time constant of ∼0.3 ps due to spectral diffusion. In contrast, 2D HD-VSFG spectrum of the CTAB/H{sub 2}O interface at 0.0 ps clearly shows two diagonal peaks and their cross peaks in the bleaching region, corresponding to the double peaks observed at 3230 cm{sup −1} and 3420 cm{sup −1} in the steady-state HD-VSFG spectrum. Horizontal slices of the 2D spectrum show that the relative intensity of the two peaks of the bleaching at the CTAB/H{sub 2}O interface gradually change with the change of the pump frequency. We simulate the pump-frequency dependence of the bleaching feature using a model that takes account of the Fermi resonance and inhomogeneity of the OH stretch vibration, and the simulated spectra reproduce the essential features of the 2D HD-VSFG spectra of the CTAB/H{sub 2}O interface. The present study demonstrates that heterodyne detection of the time-resolved VSFG is critically important for studying the ultrafast dynamics of water interfaces and for unveiling the underlying mechanism.

  9. Radiation detection and measurement concepts, methods and devices

    CERN Document Server

    McGregor, Douglas

    2019-01-01

    This text on radiation detection and measurement is a response to numerous requests expressed by students at various universities, in which the most popularly used books do not provide adequate background material, nor explain matters in understandable terms. This work provides a modern overview of radiation detection devices and radiation measurement methods. The topics selected in the book have been selected on the basis of the author’s many years of experience designing radiation detectors and teaching radiation detection and measurement in a classroom environment.

  10. Recombination emissions and spectral blueshift of pump radiation from ultrafast laser induced plasma in a planar water microjet

    Science.gov (United States)

    Anija, M.; Philip, Reji

    2009-09-01

    We report spectroscopic investigations of an ultrafast laser induced plasma generated in a planar water microjet. Plasma recombination emissions along with the spectral blueshift and broadening of the pump laser pulse contribute to the total emission. The laser pulses are of 100 fs duration, and the incident intensity is around 10 15 W/cm 2. The dominant mechanisms leading to plasma formation are optical tunnel ionization and collisional ionization. Spectrally resolved polarization measurements show that the high frequency region of the emission is unpolarized whereas the low frequency region is polarized. Results indicate that at lower input intensities the emission arises mainly from plasma recombinations, which is accompanied by a weak blueshift of the incident laser pulse. At higher input intensities strong recombination emissions are seen, along with a broadening and asymmetric spectral blueshift of the pump laser pulse. From the nature of the blueshifted laser pulse it is possible to deduce whether the rate of change of free electron density is a constant or variable within the pulse lifetime. Two input laser intensity regimes, in which collisional and tunnel ionizations are dominant respectively, have been thus identified.

  11. Radiation detection technique on the fishery foods

    International Nuclear Information System (INIS)

    Oikawa, Hiroshi; Satomi, Masataka; Nakamura, Koji; Yano, Yutaka

    1999-01-01

    Recently irradiation of fishery products such as sea bream, lobster etc has been spreading in South-east Asia. It is thus necessary to establish a detection technique for irradiated foods . This study aimed to investigate the effects of irradiation on the production of tyrosine isomers with relation to the status of food sample (frozen and cold-storage) and also the stabilities of the isomers in frozen foods after irradiation. Production of tyrosin isomers (meta-tyrosine, ortho-tyrosine) due to γ-ray irradiation (5 kGy) were observed in the muscles of frozen prawns as well as those at room temperature and the contents of these isomers after the irradiation was not different between the two states of the sample. The content increased depending on the radiation dose. The contents of these tyrosine isomers were not changed after storage at -20degC for 120 days. Therefore, it was thought that the tyrosine isomers were available as an effective indicator for detection of an irradiated food. (M.N.)

  12. Detecting solar chameleons through radiation pressure

    International Nuclear Information System (INIS)

    Baum, S.; Cantatore, G.; Hoffmann, D.H.H.; Karuza, M.; Semertzidis, Y.K.; Upadhye, A.; Zioutas, K.

    2014-01-01

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and “fifth force” searches on Earth, one needs to screen them. One possibility is the so-called “chameleon” mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on Earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary results from a force/pressure sensor, currently under development at INFN Trieste, to be mounted in the focal plane of one of the X-Ray telescopes of the CAST experiment at CERN. We show, that such an experiment signifies a pioneering effort probing uncharted chameleon parameter space

  13. Detecting solar chameleons through radiation pressure

    Energy Technology Data Exchange (ETDEWEB)

    Baum, S., E-mail: sebastian.baum@cern.ch [Uppsala Universitet, Box 516, SE 75120, Uppsala (Sweden); European Organization for Nuclear Research (CERN), Gèneve (Switzerland); Cantatore, G. [Università di Trieste, Via Valerio 2, 34127 Trieste (Italy); INFN Trieste, Padriciano 99, 34149 Trieste (Italy); Hoffmann, D.H.H. [Institut für Kernphysik, TU-Darmstadt, Schlossgartenstr. 9, D-64289 Darmstadt (Germany); Karuza, M. [INFN Trieste, Padriciano 99, 34149 Trieste (Italy); Phys. Dept. and CMNST, University of Rijeka, R. Matejcic 2, Rijeka (Croatia); Semertzidis, Y.K. [Center for Axion and Precision Physics Research (IBS), Daejeon 305-701 (Korea, Republic of); Department of Physics, KAIST, Daejeon 305-701 (Korea, Republic of); Upadhye, A. [Physics Department, University of Wisconsin–Madison, 1150 University Avenue, Madison, WI 53706 (United States); Zioutas, K., E-mail: konstantin.zioutas@cern.ch [European Organization for Nuclear Research (CERN), Gèneve (Switzerland); University of Patras, GR 26504 Patras (Greece)

    2014-12-12

    Light scalar fields can drive the accelerated expansion of the universe. Hence, they are obvious dark energy candidates. To make such models compatible with tests of General Relativity in the solar system and “fifth force” searches on Earth, one needs to screen them. One possibility is the so-called “chameleon” mechanism, which renders an effective mass depending on the local matter density. If chameleon particles exist, they can be produced in the sun and detected on Earth exploiting the equivalent of a radiation pressure. Since their effective mass scales with the local matter density, chameleons can be reflected by a dense medium if their effective mass becomes greater than their total energy. Thus, under appropriate conditions, a flux of solar chameleons may be sensed by detecting the total instantaneous momentum transferred to a suitable opto-mechanical force/pressure sensor. We calculate the solar chameleon spectrum and the reach in the chameleon parameter space of an experiment using the preliminary results from a force/pressure sensor, currently under development at INFN Trieste, to be mounted in the focal plane of one of the X-Ray telescopes of the CAST experiment at CERN. We show, that such an experiment signifies a pioneering effort probing uncharted chameleon parameter space.

  14. Radiation detection and diagnosis of breast cancer

    International Nuclear Information System (INIS)

    Dodd, G.D.

    1981-01-01

    The value of mammography in the symptomatic patient has been adequately documented, but its use as a detection procedure remains a question. Risk-benefit ratios, based primarily upon the study carried out by the Health Insurance Plan of Greater New York, have suggested that the technique has little value in individuals under age 50. Emphasis has been placed upon the possible carcinogenic effects of radiation as compared with the efficacy of mammography and the questionable influence of early diagnosis upon end results. Although technical advances have substantially reduced the exposure of the patient to radiation, the possibility of significant information loss as the result of these developments has been considered a potential drawback to their routine use. All of these factors have served to diminish both public and professional acceptance of the examination. Although current data do not allow complete resolution of these problems, certain conclusions may be drawn and trends established. The sum of these may indicate that minimal dose mammography is an accurate, low-risk procedure, capable of significantly altering the natural history of breast cancer. Whether or not the examination should be routinely used in women under age 50 remains open to question since the lack of experimental controls prohibits validation of the technique in terms of reduced mortality rates. Documentation of increased survival rates may partially assist in the established of a reliable risk-benefit ratio, but will not satisfy the statistical requirements of eliminating lead-bias, and self-selection. These questions may be resolved by studies now underway

  15. Undoped poly (phenyl sulfone) for radiation detection

    International Nuclear Information System (INIS)

    Nakamura, Hidehito; Shirakawa, Yoshiyuki; Sato, Nobuhiro; Kitamura, Hisashi; Takahashi, Sentaro

    2015-01-01

    Undoped aromatic ring polymers are potential scintillation materials. Here, we characterise poly (phenyl sulfone) (PPSU) for radiation detection. The amber-coloured transparent resin emits bluish-white fluorescence with 390-nm maximum. It has an excitation maximum of 340 nm, and has a density of 1.29 g/cm 3 . The effective refractive index based on its emission spectrum is 1.75. The light yield is almost equal to that of poly (ethylene terephthalate), which is a transparent resin. These results demonstrate that PPSU can be used as a component substrate in polymer blends for altering optical characteristics. - Highlights: • Poly (phenyl sulfone) (PPSU) has suitable characteristics as a scintillation material. • PPSU is an amber-coloured transparent resin that emits bluish white fluorescence with 390-nm maximum. • The 1.75 effective refractive index over the emission spectrum is relatively high. • The light yield is 0.95 times that of poly (ethylene terephthalate), which is a transparent resin. • PPSU can potentially alter optical characteristics in polymer blends

  16. Recent developments in analytical detection methods for radiation processed foods

    International Nuclear Information System (INIS)

    Wu Jilan

    1993-01-01

    A short summary of the programmes of 'ADMIT' (FAO/IAEA) and the developments in analytical detection methods for radiation processed foods has been given. It is suggested that for promoting the commercialization of radiation processed foods and controlling its quality, one must pay more attention to the study of analytical detection methods of irradiated food

  17. Fugitive methane leak detection using mid-infrared hollow-core photonic crystal fiber containing ultrafast laser drilled side-holes

    Science.gov (United States)

    Karp, Jason; Challener, William; Kasten, Matthias; Choudhury, Niloy; Palit, Sabarni; Pickrell, Gary; Homa, Daniel; Floyd, Adam; Cheng, Yujie; Yu, Fei; Knight, Jonathan

    2016-05-01

    The increase in domestic natural gas production has brought attention to the environmental impacts of persistent gas leakages. The desire to identify fugitive gas emission, specifically for methane, presents new sensing challenges within the production and distribution supply chain. A spectroscopic gas sensing solution would ideally combine a long optical path length for high sensitivity and distributed detection over large areas. Specialty micro-structured fiber with a hollow core can exhibit a relatively low attenuation at mid-infrared wavelengths where methane has strong absorption lines. Methane diffusion into the hollow core is enabled by machining side-holes along the fiber length through ultrafast laser drilling methods. The complete system provides hundreds of meters of optical path for routing along well pads and pipelines while being interrogated by a single laser and detector. This work will present transmission and methane detection capabilities of mid-infrared photonic crystal fibers. Side-hole drilling techniques for methane diffusion will be highlighted as a means to convert hollow-core fibers into applicable gas sensors.

  18. Three-dimensional, position-sensitive radiation detection

    Science.gov (United States)

    He, Zhong; Zhang, Feng

    2010-04-06

    Disclosed herein is a method of determining a characteristic of radiation detected by a radiation detector via a multiple-pixel event having a plurality of radiation interactions. The method includes determining a cathode-to-anode signal ratio for a selected interaction of the plurality of radiation interactions based on electron drift time data for the selected interaction, and determining the radiation characteristic for the multiple-pixel event based on both the cathode-to-anode signal ratio and the electron drift time data. In some embodiments, the method further includes determining a correction factor for the radiation characteristic based on an interaction depth of the plurality of radiation interactions, a lateral distance between the selected interaction and a further interaction of the plurality of radiation interactions, and the lateral positioning of the plurality of radiation interactions.

  19. Ultrafast secondary emission x-ray imaging detectors

    International Nuclear Information System (INIS)

    Akkerman, A.; Gibrekhterman, A.; Majewski, S.

    1991-07-01

    Fast high accuracy, x-ray imaging at high photon flux can be achieved when coupling thin solid convertors to gaseous electron multipliers, operating at low gas pressures. Secondary electron emitted from the convertor foil are multiplied in several successive amplification elements. The obvious advantage of solid x-ray detectors, as compared to gaseous conversion, are the production of parallax-free images and the fast (subnanoseconds) response. These x-ray detectors have many potential applications in basic and applied research. Of particular interest is the possibility of an efficient and ultrafast high resolution imaging of transition radiation,with a reduced dE/dx background. We present experimental results on the operation of the secondary emission x-ray (SEX) detectors, their detection efficiency, localization and time resolution. The experimental work is accompanied by mathematical modelling and computer simulation of transition radiation detectors based on CsI transition radiation convertors. (author)

  20. Obtaining information ultra-fast as-built in areas of high radiation to support decisions in maintenance

    International Nuclear Information System (INIS)

    Sarti Fernandez, F.

    2010-01-01

    One of the problems that arise when studying, planning and assessing a particular maintenance operation has to be performed in high radiation areas, is the determination of the level of reliability of information starting from the one available. For the past several years have been used in nuclear power plants worldwide acquisition systems called 3D laser scanner models.

  1. Semiconductors Under Ion Radiation: Ultrafast Electron-Ion Dynamics in Perfect Crystals and the Effect of Defects

    Science.gov (United States)

    Lee, Cheng-Wei; Schleife, André

    Stability and safety issues have been challenging difficulties for materials and devices under radiation such as solar panels in outer space. On the other hand, radiation can be utilized to modify materials and increase their performance via focused-ion beam patterning at nano-scale. In order to grasp the underlying processes, further understanding of the radiation-material and radiation-defect interactions is required and inevitably involves the electron-ion dynamics that was traditionally hard to capture. By applying Ehrenfest dynamics based on time-dependent density functional theory, we have been able to perform real-time simulation of electron-ion dynamics in MgO and InP/GaP. By simulating a high-energy proton penetrating the material, the energy gain of electronic system can be interpreted as electronic stopping power and the result is compared to existing data. We also study electronic stopping in the vicinity of defects: for both oxygen vacancy in MgO and interface of InP/GaP superlattice, electronic stopping shows strong dependence on the velocity of the proton. To study the energy transfer from electronic system to lattice, simulations of about 100 femto-seconds are performed and we analyze the difference between Ehrenfest and Born-Oppenheimer molecular dynamics.

  2. Ultrafast laser pump/x-ray probe experiments

    International Nuclear Information System (INIS)

    Larsson, J.; Judd, E.; Schuck, P.J.

    1997-01-01

    In an ongoing project aimed at probing solids using x-rays obtained at the ALS synchrotron with a sub-picosecond time resolution following interactions with a 100 fs laser pulse, the authors have successfully performed pump-probe experiments limited by the temporal duration of ALS-pulse. They observe a drop in the diffraction efficiency following laser heating. They can attribute this to a disordering of the crystal. Studies with higher temporal resolution are required to determine the mechanism. The authors have also incorporated a low-jitter streakcamera as a diagnostic for observing time-dependant x-ray diffraction. The streakcamera triggered by a photoconductive switch was operated at kHz repetition rates. Using UV-pulses, the authors obtain a temporal response of 2 ps when averaging 5000 laser pulses. They demonstrate the ability to detect monochromatized x-ray radiation from a bend-magnet with the streak camera by measuring the pulse duration of a x-ray pulse to 70 ps. In conclusion, the authors show a rapid disordering of an InSb crystal. The resolution was determined by the duration of the ALS pulse. They also demonstrate that they can detect x-ray radiation from a synchrotron source with a temporal resolution of 2ps, by using an ultrafast x-ray streak camera. Their set-up will allow them to pursue laser pump/x-ray probe experiments to monitor structural changes in materials with ultrafast time resolution

  3. Preliminary data on the prognostic value of a new protocol of ultra-fast myocardial scintigraphy with less radiation in CZT gamma camera

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Ronaldo; Peclat, Thais; Amaral, Ana Carolina; Nakamoto, Aline; Lavagnoli, Daniel; Oliveira, Felipe; De Lorenzo, Andrea, E-mail: ronlima@hotmail.com [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2016-01-15

    Background: Myocardial perfusion scintigraphy (MPS) is one of the most used imaging methods for the evaluation of patients for coronary artery disease (CAD) due to its diagnostic and prognostic value. Two of its main limitations are radiation use and scan duration. However, CZT cameras (CZT-C) have allowed tracer dose and scan time reductions. However, the prognostic value of these new protocols is not known. Objective: To determine the prognostic value of a new, ultrafast, low dose protocol in a CZT-C. Population: Patients with suspect CAD undergoing MPS from 11/2011 to 6/2012 were studied. Methods: They had a 1-day Tc-99m sestamibi protocol starting with rest study (5 mCi dose) followed by stress (15 mCi). Acquisition times were 6 and 3 minutes respectively. MPS studied were classified as normal or abnormal and perfusion scores (SSS, SRS and SDS) were calculated. Patients were accompanied by 6-month phone calls. Events were defined as death, nonfatal myocardial infarction and late revascularization (> 60 days after MPS) and analyzed with the Cox method. Results: 792 patients were followed for 21.3 ± 3.7 months. Age was 65.2 ± 12.7 years, 50.3% were male and body mass index was 26.9 ± 4.7. Hypertension was the most frequent risk factor (59.5%), followed by hypercholesterolemia (51.9%) and diabetes (23.3%). Exercise was used in 438 (55.3%); 618 (78%) MPS studies were normal. Mean dosimetry was 6 mSv and mean scan time, 48 ± 11 minutes. During follow-up, there were 12 deaths, 4 nonfatal infarctions, 42 angioplasties and 5 coronary artery bypass surgeries. Annual hard event rate was higher in patients with abnormal MPS (3.0% vs. 0.7%, p < 0.01), as well as the frequency of patients undergoing late revascularization (10.8% vs 1.9%, p < 0.001). SSS and SDS were higher in patients with hard events compared to those without events (7.8 ± 8.8 vs 2.9 ± 5.7; 3.3 ± 5.7 vs 0.7 ± 2.2, p < 0.01) and among revascularized patients compared to non-revascularized (7.1 ± 7

  4. Study of the casting speedy radiation-detection system

    International Nuclear Information System (INIS)

    Tan Xiaochun; Huang Junqing; Shi Xianbei; Zhao Gang; Wang Liping

    2001-01-01

    The paper introduces the design of the launching speedy radiation-detection system. It consists of launcher, semiconductor detector, microprocessor and communicator. It can give the intensity, position, time of radiation. The paper discusses the function, composition, principle, speciality and technical problem of this system

  5. Radiation Detection Overview for Nuclear Emergency Response

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Steven Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-16

    This presentation discusses the fundamentals of gamma and neutron detection; presents an overview of the DOE Triage and JTOT Programs, gamma, and neutron signatures in select measurements; and offers a detector demonstration.

  6. Nuclear radiation detection with superconducting tunnel junctions

    International Nuclear Information System (INIS)

    Kurakado, Masahiko

    1984-01-01

    Since the gap energy of superconductors is as small as 1 meV and 1/1000 of that of semiconductors, it is expected that the number of electron-hole pairs produced in superconductors by radiation is several thousands times as many as the pairs in semiconductors. Therefore, high sensitivity and high resolution radiation detectors may be manufactured by using superconductors. A computer simulation of the cascade excitation process of electrons was carried out. The experimental study was performed by using Sn junctions. The variation of transient voltage was measured by the constant current method. The alpha particles from Po-210 were measured, and the generation of quasi particles was confirmed. The relaxation time of signals was measured by using pulsed laser beam. It was found that the superconductors just after the incidence of radiation became nonequilibrium. The typical alpha spectra were obtained by cooling the superconductors to 0.32 K. The detector is still under development. The problem is leakage current. (Kato, T.)

  7. Rubella virus detection by ELISA method in exposed radiation workers

    International Nuclear Information System (INIS)

    Wu Jianmei; Zhu Bo; Zhu Youming; Shao Jinhui; Wu Weiping; Han Jinxiang

    2005-01-01

    Objective: A rapid diagnosis method was developed to detect Rubella virus infection in radiation workers. Methods: Modified ELISA method was used to detect the level of lgG and lgM antibodies in 514 in Jinan district. Results: 90.47% of 514 cases was shown to be resistant against Rubella virus; 6.42% were sensitive type; 0.78% belonged to be reinfected. Conclusion: Detection of Rubella virus in exposed radiation workers was imperative, and vaccine against Rubella virus was also needed to eliminate the infection risk. (authors)

  8. Advanced concepts in multi-dimensional radiation detection and imaging

    International Nuclear Information System (INIS)

    Vetter, Kai; Barnowski, Ross; Pavlovsky, Ryan; Haefner, Andy; Torii, Tatsuo; Shikaze, Yoshiaki; Sanada, Yukihisa

    2016-01-01

    Recent developments in the detector fabrication, signal readout, and data processing enable new concepts in radiation detection that are relevant for applications ranging from fundamental physics to medicine as well as nuclear security and safety. We present recent progress in multi-dimensional radiation detection and imaging in the Berkeley Applied Nuclear Physics program. It is based on the ability to reconstruct scenes in three dimensions and fuse it with gamma-ray image information. We are using the High-Efficiency Multimode Imager HEMI in its Compton imaging mode and combining it with contextual sensors such as the Microsoft Kinect or visual cameras. This new concept of volumetric imaging or scene data fusion provides unprecedented capabilities in radiation detection and imaging relevant for the detection and mapping of radiological and nuclear materials. This concept brings us one step closer to the seeing the world with gamma-ray eyes. (author)

  9. Curcumin-Based "Enhanced SNAr" Promoted Ultrafast Fluorescent Probe for Thiophenols Detection in Aqueous Solution and in Living Cells.

    Science.gov (United States)

    Yue, Yongkang; Huo, Fangjun; Zhang, Yongbin; Chao, Jianbin; Martínez-Máñez, Ramón; Yin, Caixia

    2016-11-01

    We report herein a highly selective and sensitive turn-on fluorescent probe (compound 1) with a fast response time (less than 2 min) for thiophenol detection based on an "enhanced S N Ar" reaction between thiophenols and a sulfonyl-ester moiety covalently attach to curcumin. Reaction of 1 in Hepes-MeOH (1:1, v/v, pH 7.4) in the presence of 4-methylthiophenol (MTP) resulted in a remarkable enhancement of the fluorescence. A linear response in the presence of MTP of the relative fluorescent intensity (F - F 0 ) of 1 at 536 nm in the 0-40 μM MTP concentration range was found. A limit of detection (LOD) for the detection of MTP of 26 nM, based on the definition by IUPAC (C DL = 3 Sb/m), was calculated. Probe 1 was applied to monitor and imaging exogenous MTP in live cells and to the detection of MTP in real water samples.

  10. The EPR detection of radiation treated foodstuffs

    International Nuclear Information System (INIS)

    Stachowicz, W.; Burlinska, G.; Michalik, J.; Ostrowski, K.; Dziedzic-Goclawska, A.

    1993-01-01

    The short paper by a Polish study group describes the results of the use of Electron Paramagnetic Resonance (EPR) Spectroscopy in the detection of irradiation to food. Pultry, fresh-water fish and sea fish as well as various fruits and yellow boletus are dealt with in some detail. (VHE) [de

  11. Development of radiation detection and measurement systems

    Energy Technology Data Exchange (ETDEWEB)

    Moon, B. S.; Ham, C. S.; Chung, C. E. and others

    2000-03-01

    This report contains descriptions on the following six items. The first item is the result of a study on CsI(TI) crystals with their light emitting characteristics and the result of a study on plastic scintillators. The second item is the result of a study on advanced radiation detectors and includes experiments for the effect of using a Compton suppressor with an HPGe detector. For the third item, we describe the results of a design work done using EGS4 for a thickness gauge, a density gauge, and a level gauge. The fourth item contains descriptions on the prototype circuit systems developed for a level gauge, a thickness gauge, and for a survey meter. The fifth part contains the computed tomography algorithm and a prototype scanning system developed for a CT system. As the sixth and the last item, we describe the prototype high precision heat source and the prototype heat-voltage converter which we have designed and fabricated.

  12. Development of radiation detection and measurement systems

    International Nuclear Information System (INIS)

    Moon, B. S.; Ham, C. S.; Chung, C. E. and others

    2000-03-01

    This report contains descriptions on the following six items. The first item is the result of a study on CsI(TI) crystals with their light emitting characteristics and the result of a study on plastic scintillators. The second item is the result of a study on advanced radiation detectors and includes experiments for the effect of using a Compton suppressor with an HPGe detector. For the third item, we describe the results of a design work done using EGS4 for a thickness gauge, a density gauge, and a level gauge. The fourth item contains descriptions on the prototype circuit systems developed for a level gauge, a thickness gauge, and for a survey meter. The fifth part contains the computed tomography algorithm and a prototype scanning system developed for a CT system. As the sixth and the last item, we describe the prototype high precision heat source and the prototype heat-voltage converter which we have designed and fabricated

  13. Optimised mounting conditions for poly (ether sulfone) in radiation detection.

    Science.gov (United States)

    Nakamura, Hidehito; Shirakawa, Yoshiyuki; Sato, Nobuhiro; Yamada, Tatsuya; Kitamura, Hisashi; Takahashi, Sentaro

    2014-09-01

    Poly (ether sulfone) (PES) is a candidate for use as a scintillation material in radiation detection. Its characteristics, such as its emission spectrum and its effective refractive index (based on the emission spectrum), directly affect the propagation of light generated to external photodetectors. It is also important to examine the presence of background radiation sources in manufactured PES. Here, we optimise the optical coupling and surface treatment of the PES, and characterise its background. Optical grease was used to enhance the optical coupling between the PES and the photodetector; absorption by the grease of short-wavelength light emitted from PES was negligible. Diffuse reflection induced by surface roughening increased the light yield for PES, despite the high effective refractive index. Background radiation derived from the PES sample and its impurities was negligible above the ambient, natural level. Overall, these results serve to optimise the mounting conditions for PES in radiation detection. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Assembly of gamma radiation detection with directivity properties

    International Nuclear Information System (INIS)

    Stoica, M.; Talpalariu, C.

    2016-01-01

    An assembly of gamma radiation detection with directivity properties and small size enables the development of portable equipment or robots specialized in finding and signaling radioactively contaminated areas in case of nuclear incidents or decommissioning of nuclear installations. Directivity characteristic of the assembly of gamma radiation detection is very important when aiming to build an equipment for searching radioactively contaminated areas. In order to obtain a suitable directivity characteristics in terms of detection of gamma rays, it was necessary to construct a lead collimator with a cylindrical shape. The detector, preamplifier and amplifier pulse were placed inside the collimator and pulse discriminator circuit and power source were placed beside the collimator, all being disposed within the housing cylindrical experimental. A PIN photodiode type was used as a detector of gamma radiation. (authors)

  15. Development of Quantum Devices and Algorithms for Radiation Detection and Radiation Signal Processing

    International Nuclear Information System (INIS)

    El Tokhy, M.E.S.M.E.S.

    2012-01-01

    The main functions of spectroscopy system are signal detection, filtering and amplification, pileup detection and recovery, dead time correction, amplitude analysis and energy spectrum analysis. Safeguards isotopic measurements require the best spectrometer systems with excellent resolution, stability, efficiency and throughput. However, the resolution and throughput, which depend mainly on the detector, amplifier and the analog-to-digital converter (ADC), can still be improved. These modules have been in continuous development and improvement. For this reason we are interested with both the development of quantum detectors and efficient algorithms of the digital processing measurement. Therefore, the main objective of this thesis is concentrated on both 1. Study quantum dot (QD) devices behaviors under gamma radiation 2. Development of efficient algorithms for handling problems of gamma-ray spectroscopy For gamma radiation detection, a detailed study of nanotechnology QD sources and infrared photodetectors (QDIP) for gamma radiation detection is introduced. There are two different types of quantum scintillator detectors, which dominate the area of ionizing radiation measurements. These detectors are QD scintillator detectors and QDIP scintillator detectors. By comparison with traditional systems, quantum systems have less mass, require less volume, and consume less power. These factors are increasing the need for efficient detector for gamma-ray applications such as gamma-ray spectroscopy. Consequently, the nanocomposite materials based on semiconductor quantum dots has potential for radiation detection via scintillation was demonstrated in the literature. Therefore, this thesis presents a theoretical analysis for the characteristics of QD sources and infrared photodetectors (QDIPs). A model of QD sources under incident gamma radiation detection is developed. A novel methodology is introduced to characterize the effect of gamma radiation on QD devices. The rate

  16. Ionizing radiation source detection by personal TLD

    International Nuclear Information System (INIS)

    Marinkovic, O.; Mirkov, Z.

    2002-01-01

    The Laboratory for personal dosimetry has about 3000 workers under control. The most of them work in medicine. Some institutions, as big health centers, have different ionizing radiation sources. It is usefull to analyze what has been the source of irradiation, special when appears a dosimeter with high dose. Personal dosimetry equipment is Harshaw TLD Reader Model 6600 and dosimeters consist of two chips LiF TLD-100 assembled in bar-coded cards which are wearing in holders with one tissue-equivalent filter (to determine H(10)) and skin-equivalent the other (to determine H(0.07)). The calibration dosimeters have been irradiated in holders by different sources: x-ray (for 80keV and 100keV), 6 0C o, 9 0S r (for different distances from beta source) and foton beem (at radiotherapy accelerator by 6MeV, 10MeV and 18MeV). The dose ratio for two LiF cristals was calculated and represented with graphs. So, it is possible to calculate the ratio H(10)/H(0.07) for a personal TLD and analyze what has been the source of irradiation. Also, there is the calibration for determination the time of irradiation, according to glow curve deconvolution

  17. Ultrafast electron microscopy in materials science, biology, and chemistry

    International Nuclear Information System (INIS)

    King, Wayne E.; Campbell, Geoffrey H.; Frank, Alan; Reed, Bryan; Schmerge, John F.; Siwick, Bradley J.; Stuart, Brent C.; Weber, Peter M.

    2005-01-01

    The use of pump-probe experiments to study complex transient events has been an area of significant interest in materials science, biology, and chemistry. While the emphasis has been on laser pump with laser probe and laser pump with x-ray probe experiments, there is a significant and growing interest in using electrons as probes. Early experiments used electrons for gas-phase diffraction of photostimulated chemical reactions. More recently, scientists are beginning to explore phenomena in the solid state such as phase transformations, twinning, solid-state chemical reactions, radiation damage, and shock propagation. This review focuses on the emerging area of ultrafast electron microscopy (UEM), which comprises ultrafast electron diffraction (UED) and dynamic transmission electron microscopy (DTEM). The topics that are treated include the following: (1) The physics of electrons as an ultrafast probe. This encompasses the propagation dynamics of the electrons (space-charge effect, Child's law, Boersch effect) and extends to relativistic effects. (2) The anatomy of UED and DTEM instruments. This includes discussions of the photoactivated electron gun (also known as photogun or photoelectron gun) at conventional energies (60-200 keV) and extends to MeV beams generated by rf guns. Another critical aspect of the systems is the electron detector. Charge-coupled device cameras and microchannel-plate-based cameras are compared and contrasted. The effect of various physical phenomena on detective quantum efficiency is discussed. (3) Practical aspects of operation. This includes determination of time zero, measurement of pulse-length, and strategies for pulse compression. (4) Current and potential applications in materials science, biology, and chemistry. UEM has the potential to make a significant impact in future science and technology. Understanding of reaction pathways of complex transient phenomena in materials science, biology, and chemistry will provide fundamental

  18. ITRAP. Illicit trafficking radiation detection assessment program

    International Nuclear Information System (INIS)

    Beck, P.

    2001-02-01

    Illicit trafficking in nuclear materials (nuclear criminality) has become more and more a problem, due to the circulation of the a high number of radioactive sources and the big amount of nuclear material, particularly, caused by the changes of the organisational infrastructures to supervise these material within the successor states of the former Soviet Union. The IAEA data base counts at present more than 300 verified cases. The endangering cased thereby ranges from possible health defect for the publication to terrorists activities and production of nuclear weapons. In addition to the primary criminal reasons the illegal deposal of radioactive sources as salvage, scrap and others show a further problem, which has lead to severe accidents and lethal effects in the past (e.g. Goiana, Mexiko). As the study ITRAP (Illicit Trafficking Radiation Assessment Program) can show, also in Austria the cases of partly considerable contaminated scrap transports from neighbouring countries exists. Some countries have already under taken countermeasures (e.g. Monitoring at the Finnish-Russian and German-Polish border, border monitoring in Italy). The International Atomic Energy Agency (IAEA) has reacted on this actual problem by setting up a new program to fight against nuclear criminality and has suggested a pilot study for the practical test of border monitoring systems. Aim of the study was to work out the technical requirements and the practicability of an useful monitoring system at border crossings. The results of the study will be offered by the IAEA to the member states as international recommendations for border monitoring systems. (author)

  19. Radiation detection technique on the fishery foods

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Koji; Yano, Yutaka; Oikawa, Hiroshi [National Research Inst. of Fisheries Science, Yokohama (Japan)

    2000-02-01

    When muscles and myofibril are irradiated by gamma ray, Mg-ATPase activity increased with increasing of dose, but EDTA-ATPase decreased. If dose is very large, Ca-ATPase activity increased. The effects of state of protein on these phenomena were investigated. The muscles, myofibril and myosin B of Tilapia nilotica were used as samples. Change of Ca-ATPase, Mg-ATPase and EDTA-ATPase activity of myosin B by gamma-ray irradiation was the same as myofibril and muscles, but myosin B showed high sensitivity and each ATPase activity was changed by low dose. Accordingly, these values were more difficult to apply to detection technique of irradiation than state of muscle and myofibril. Collagen is known to degenerate and coagulate by gamma-ray irradiation. However, amount of hot water soluble collagen was increased with increasing of dose. (S.Y.)

  20. Conducted and radiated noise in detection devices

    International Nuclear Information System (INIS)

    Moisa, D.

    2001-01-01

    Conducted and radiated noise is an external noise which affects the quality of the signals of the detectors. An external noise can be reduced, usually, by shielding. This was the situation with 'older fashion' devices which uses boxes and coaxial cables. As the devices becomes more complex, the shielding of the detectors is more and more difficult and the transmission lines evolves from coaxial cables to twisted pair cables which are no more shielded. In such situation, the conducted and radiated noise (C and R noise) becomes important. Due to complexity of a real detector, the main work is based on experiments with components and simulations of some specific problems, associated with CDC detector. The first experiment was done to understand how the C and R noise is propagated. The emission device was a set of coils (between 3 and 5 turns with diameter from 10 to 50 mm) feed by an 74S140 driver. A pulse of about 8 ns width was generated. A coil of reception of about the same physical characteristics was used to see the emitted pulse. When the two coils are separated by about 80 cm, the receiver generated no signal. But, if along the two coils, a conductive material is introduced (a wire for instance), the receiver senses a signal. This signal is not changed too much if the wire is or not connected to ground. The explanation is simple: the pulse in the emitting coil produces an EM pulse which spreads in space. If a conductive material is around, the EM energy is received by that conductor and it is propagated at tens of meters with small attenuation. When this energy reaches the end of the conductor, it is radiated in space. If some other conductors are around, the energy is received and propagated by that conductors. This experiment was done for about 20 kinds of conductors (different coax cables, twisted-pair ribbons, power cables, metallic bars) and with many coils (different diameters and numbers of turns). It was measured the pk-to-pk level, decay constant and

  1. Method and circuit for stabilizing conversion gain of radiation detectors of a radiation detection system

    International Nuclear Information System (INIS)

    Stoub, E.W.

    1986-01-01

    A method is described for calibrating the gain of an array of radiation detectors of a radiation detection system comprising the steps of: (a) measuring in parallel for each radiation detector using a predetermined calibration point the energy map status, thereby obtaining an energy response vector whose elements correspond to the individual output of each radiation detector, each predetermined calibration point being a prescribed location corresponding to one of the radiation detectors; (b) multiplying that energy response vector with a predetermined deconvolution matrix, the deconvolution matrix being the inversion of a contribution matrix containing matrix elements C/sub IJ/, each such matrix element C/sub IJ/ of the contribution matrix representing the relative contribution level of a radiation detector j of the detection system for a point radiation source placed at a location i, thereby obtaining a gain vector product for the radiation detectors; (c) adjusting the gains of the radiation detectors with respect to the gain vector product such that a unity gain vector is essentially obtained; (d) measuring again the energy map status according to step (a); and (e) if the energy map status fails to essentially produce a unity gain vector repeat steps (a) to (d) until the energy map status substantially corresponds to unity

  2. Nano-Mole Scale Side-Chain Signal Assignment by 1H-Detected Protein Solid-State NMR by Ultra-Fast Magic-Angle Spinning and Stereo-Array Isotope Labeling

    KAUST Repository

    Wang, Songlin

    2015-04-09

    We present a general approach in 1H-detected 13C solid-state NMR (SSNMR) for side-chain signal assignments of 10-50 nmol quantities of proteins using a combination of a high magnetic field, ultra-fast magic-angle spinning (MAS) at ~80 kHz, and stereo-array-isotope-labeled (SAIL) proteins [Kainosho M. et al., Nature 440, 52–57, 2006]. First, we demonstrate that 1H indirect detection improves the sensitivity and resolution of 13C SSNMR of SAIL proteins for side-chain assignments in the ultra-fast MAS condition. 1H-detected SSNMR was performed for micro-crystalline ubiquitin (~55 nmol or ~0.5mg) that was SAIL-labeled at seven isoleucine (Ile) residues. Sensitivity was dramatically improved by 1H-detected 2D 1H/13C SSNMR by factors of 5.4-9.7 and 2.1-5.0, respectively, over 13C-detected 2D 1H/13C SSNMR and 1D 13C CPMAS, demonstrating that 2D 1H-detected SSNMR offers not only additional resolution but also sensitivity advantage over 1D 13C detection for the first time. High 1H resolution for the SAIL-labeled side-chain residues offered reasonable resolution even in the 2D data. A 1H-detected 3D 13C/13C/1H experiment on SAIL-ubiquitin provided nearly complete 1H and 13C assignments for seven Ile residues only within ~2.5 h. The results demonstrate the feasibility of side-chain signal assignment in this approach for as little as 10 nmol of a protein sample within ~3 days. The approach is likely applicable to a variety of proteins of biological interest without any requirements of highly efficient protein expression systems.

  3. Nano-Mole Scale Side-Chain Signal Assignment by 1H-Detected Protein Solid-State NMR by Ultra-Fast Magic-Angle Spinning and Stereo-Array Isotope Labeling

    KAUST Repository

    Wang, Songlin; Parthasarathy, Sudhakar; Nishiyama, Yusuke; Endo, Yuki; Nemoto, Takahiro; Yamauchi, Kazuo; Asakura, Tetsuo; Takeda, Mitsuhiro; Terauchi, Tsutomu; Kainosho, Masatsune; Ishii, Yoshitaka

    2015-01-01

    We present a general approach in 1H-detected 13C solid-state NMR (SSNMR) for side-chain signal assignments of 10-50 nmol quantities of proteins using a combination of a high magnetic field, ultra-fast magic-angle spinning (MAS) at ~80 kHz, and stereo-array-isotope-labeled (SAIL) proteins [Kainosho M. et al., Nature 440, 52–57, 2006]. First, we demonstrate that 1H indirect detection improves the sensitivity and resolution of 13C SSNMR of SAIL proteins for side-chain assignments in the ultra-fast MAS condition. 1H-detected SSNMR was performed for micro-crystalline ubiquitin (~55 nmol or ~0.5mg) that was SAIL-labeled at seven isoleucine (Ile) residues. Sensitivity was dramatically improved by 1H-detected 2D 1H/13C SSNMR by factors of 5.4-9.7 and 2.1-5.0, respectively, over 13C-detected 2D 1H/13C SSNMR and 1D 13C CPMAS, demonstrating that 2D 1H-detected SSNMR offers not only additional resolution but also sensitivity advantage over 1D 13C detection for the first time. High 1H resolution for the SAIL-labeled side-chain residues offered reasonable resolution even in the 2D data. A 1H-detected 3D 13C/13C/1H experiment on SAIL-ubiquitin provided nearly complete 1H and 13C assignments for seven Ile residues only within ~2.5 h. The results demonstrate the feasibility of side-chain signal assignment in this approach for as little as 10 nmol of a protein sample within ~3 days. The approach is likely applicable to a variety of proteins of biological interest without any requirements of highly efficient protein expression systems.

  4. Networked gamma radiation detection system for tactical deployment

    Science.gov (United States)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ronald; Smith, Ethan; Guss, Paul; Mitchell, Stephen

    2015-08-01

    A networked gamma radiation detection system with directional sensitivity and energy spectral data acquisition capability is being developed by the National Security Technologies, LLC, Remote Sensing Laboratory to support the close and intense tactical engagement of law enforcement who carry out counterterrorism missions. In the proposed design, three clusters of 2″ × 4″ × 16″ sodium iodide crystals (4 each) with digiBASE-E (for list mode data collection) would be placed on the passenger side of a minivan. To enhance localization and facilitate rapid identification of isotopes, advanced smart real-time localization and radioisotope identification algorithms like WAVRAD (wavelet-assisted variance reduction for anomaly detection) and NSCRAD (nuisance-rejection spectral comparison ratio anomaly detection) will be incorporated. We will test a collection of algorithms and analysis that centers on the problem of radiation detection with a distributed sensor network. We will study the basic characteristics of a radiation sensor network and focus on the trade-offs between false positive alarm rates, true positive alarm rates, and time to detect multiple radiation sources in a large area. Empirical and simulation analyses of critical system parameters, such as number of sensors, sensor placement, and sensor response functions, will be examined. This networked system will provide an integrated radiation detection architecture and framework with (i) a large nationally recognized search database equivalent that would help generate a common operational picture in a major radiological crisis; (ii) a robust reach back connectivity for search data to be evaluated by home teams; and, finally, (iii) a possibility of integrating search data from multi-agency responders.

  5. Development of a novel gamma probe for detecting radiation direction

    Science.gov (United States)

    Pani, R.; Pellegrini, R.; Cinti, M. N.; Longo, M.; Donnarumma, R.; D'Alessio, A.; Borrazzo, C.; Pergola, A.; Ridolfi, S.; De Vincentis, G.

    2016-01-01

    Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security.

  6. The problem of the detection threshold in radiation measurement

    International Nuclear Information System (INIS)

    Rose, E.; Wueneke, C.D.

    1983-01-01

    In all cases encountered in practical radiation measurement, the basic problem is to differentiate between the lowest measured value and the zero value (background, natural background radiation, etc.). For this purpose, on the mathematical side, tests based on hypotheses are to be applied. These will show the probability of differentiation between two values having the same random spread. By means of these tests and the corresponding error theory, a uniform treatment of the subject, applicable to all problems relating to measuring technique alike, can be found. Two basic concepts are found in this process, which have to be defined in terms of semantics and nomenclature: Decision threshold and detection threshold, or 'minimum detectable mean value'. At the decision threshold, one has to decide (with a given statistical error probability) whether a measured value is to be attributed to the background radiation, accepting the zero hypothesis, or whether this value differs significantly from the background radiation (error of 1rst kind). The minimum detectable mean value is the value which, with a given decision threshold, can be determined with sufficient significance to be a measured value and thus cannot be mistaken as background radiation (alternative hypothesis, error of 2nd kind). Normally, the two error types are of equal importance. It may happen, however, that one type of error gains more importance, depending on the approach. (orig.) [de

  7. Development of a novel gamma probe for detecting radiation direction

    International Nuclear Information System (INIS)

    Pani, R.; Pellegrini, R.; Cinti, M.N.; Longo, M.; Donnarumma, R.; Borrazzo, C.; D'Alessio, A.; Pergola, A.; Ridolfi, S.; Vincentis, G. De

    2016-01-01

    Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security

  8. Calibration of a Stereo Radiation Detection Camera Using Planar Homography

    Directory of Open Access Journals (Sweden)

    Seung-Hae Baek

    2016-01-01

    Full Text Available This paper proposes a calibration technique of a stereo gamma detection camera. Calibration of the internal and external parameters of a stereo vision camera is a well-known research problem in the computer vision society. However, few or no stereo calibration has been investigated in the radiation measurement research. Since no visual information can be obtained from a stereo radiation camera, it is impossible to use a general stereo calibration algorithm directly. In this paper, we develop a hybrid-type stereo system which is equipped with both radiation and vision cameras. To calibrate the stereo radiation cameras, stereo images of a calibration pattern captured from the vision cameras are transformed in the view of the radiation cameras. The homography transformation is calibrated based on the geometric relationship between visual and radiation camera coordinates. The accuracy of the stereo parameters of the radiation camera is analyzed by distance measurements to both visual light and gamma sources. The experimental results show that the measurement error is about 3%.

  9. Ultrafast nonlinear optics

    CERN Document Server

    Leburn, Christopher; Reid, Derryck

    2013-01-01

    The field of ultrafast nonlinear optics is broad and multidisciplinary, and encompasses areas concerned with both the generation and measurement of ultrashort pulses of light, as well as those concerned with the applications of such pulses. Ultrashort pulses are extreme events – both in terms of their durations, and also the high peak powers which their short durations can facilitate. These extreme properties make them powerful experiment tools. On one hand, their ultrashort durations facilitate the probing and manipulation of matter on incredibly short timescales. On the other, their ultrashort durations can facilitate high peak powers which can drive highly nonlinear light-matter interaction processes. Ultrafast Nonlinear Optics covers a complete range of topics, both applied and fundamental in nature, within the area of ultrafast nonlinear optics. Chapters 1 to 4 are concerned with the generation and measurement of ultrashort pulses. Chapters 5 to 7 are concerned with fundamental applications of ultrasho...

  10. ANOLE Portable Radiation Detection System Field Test and Evaluation Campaign

    International Nuclear Information System (INIS)

    Hodge, Chris A.

    2007-01-01

    Handheld, backpack, and mobile sensors are elements of the Global Nuclear Detection System for the interdiction and control of illicit radiological and nuclear materials. They are used by the U.S. Department of Homeland Security (DHS) and other government agencies and organizations in various roles for border protection, law enforcement, and nonproliferation monitoring. In order to systematically document the operational performance of the common commercial off-the-shelf portable radiation detection systems, the DHS Domestic Nuclear Detection Office conducted a test and evaluation campaign conducted at the Nevada Test Site from January 18 to February 27, 2006. Named 'Anole', it was the first test of its kind in terms of technical design and test complexities. The Anole test results offer users information for selecting appropriate mission-specific portable radiation detection systems. The campaign also offered manufacturers the opportunity to submit their equipment for independent operationally relevant testing to subsequently improve their detector performance. This paper will present the design, execution, and methodologies of the DHS Anole portable radiation detection system test campaign

  11. Multi-sensor radiation detection, imaging, and fusion

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, Kai [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2016-01-01

    Glenn Knoll was one of the leaders in the field of radiation detection and measurements and shaped this field through his outstanding scientific and technical contributions, as a teacher, his personality, and his textbook. His Radiation Detection and Measurement book guided me in my studies and is now the textbook in my classes in the Department of Nuclear Engineering at UC Berkeley. In the spirit of Glenn, I will provide an overview of our activities at the Berkeley Applied Nuclear Physics program reflecting some of the breadth of radiation detection technologies and their applications ranging from fundamental studies in physics to biomedical imaging and to nuclear security. I will conclude with a discussion of our Berkeley Radwatch and Resilient Communities activities as a result of the events at the Dai-ichi nuclear power plant in Fukushima, Japan more than 4 years ago. - Highlights: • .Electron-tracking based gamma-ray momentum reconstruction. • .3D volumetric and 3D scene fusion gamma-ray imaging. • .Nuclear Street View integrates and associates nuclear radiation features with specific objects in the environment. • Institute for Resilient Communities combines science, education, and communities to minimize impact of disastrous events.

  12. 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.

  13. Organic materials and devices for detecting ionizing radiation

    Science.gov (United States)

    Doty, F Patrick [Livermore, CA; Chinn, Douglas A [Livermore, CA

    2007-03-06

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

  14. Flexible Receiver Radiation Detection System (FRRDS) Users Manual

    International Nuclear Information System (INIS)

    Troyer, G.L.

    1996-01-01

    The Flexible Receiver Radiation Detection System (FRRDS) comprises a control computer, a remote data acquisition subsystem, and three hyperpure germanium gamma radiation detectors. The scope of this document is the description of various steps for the orderly start-up, use, and shutdown of the FRRDS. Only those items necessary for these oprations are included. This document is a companion to WHC-SD-W151-UM-002, 'Operating Instructions for the 42 Inch Flexible Receiver,' WHC-SD-W151-UM-003, 'Operating Instructions for the 4-6 Inch Flexible Receiver,' and the vendor supplied system users guide (Ref. 6)

  15. Development and deployment of the Collimated Directional Radiation Detection System

    Science.gov (United States)

    Guckes, Amber L.; Barzilov, Alexander

    2017-09-01

    The Collimated Directional Radiation Detection System (CDRDS) is capable of imaging radioactive sources in two dimensions (as a directional detector). The detection medium of the CDRDS is a single Cs2LiYCl6:Ce3+ scintillator cell enriched in 7Li (CLYC-7). The CLYC-7 is surrounded by a heterogeneous high-density polyethylene (HDPE) and lead (Pb) collimator. These materials make-up a coded aperture inlaid in the collimator. The collimator is rotated 360° by a stepper motor which enables time-encoded imaging of a radioactive source. The CDRDS is capable of spectroscopy and pulse shape discrimination (PSD) of photons and fast neutrons. The measurements of a radioactive source are carried out in discrete time steps that correlate to the angular rotation of the collimator. The measurement results are processed using a maximum likelihood expectation (MLEM) algorithm to create an image of the measured radiation. This collimator design allows for the directional detection of photons and fast neutrons simultaneously by utilizing only one CLYC-7 scintillator. Directional detection of thermal neutrons can also be performed by utilizing another suitable scintillator. Moreover, the CDRDS is portable, robust, and user friendly. This unit is capable of utilizing wireless data transfer for possible radiation mapping and network-centric applications. The CDRDS was tested by performing laboratory measurements with various gamma-ray and neutron sources.

  16. Current trends in gamma radiation detection for radiological emergency response

    Science.gov (United States)

    Mukhopadhyay, Sanjoy; Guss, Paul; Maurer, Richard

    2011-09-01

    Passive and active detection of gamma rays from shielded radioactive materials, including special nuclear materials, is an important task for any radiological emergency response organization. This article reports on the current trends and status of gamma radiation detection objectives and measurement techniques as applied to nonproliferation and radiological emergencies. In recent years, since the establishment of the Domestic Nuclear Detection Office by the Department of Homeland Security, a tremendous amount of progress has been made in detection materials (scintillators, semiconductors), imaging techniques (Compton imaging, use of active masking and hybrid imaging), data acquisition systems with digital signal processing, field programmable gate arrays and embedded isotopic analysis software (viz. gamma detector response and analysis software [GADRAS]1), fast template matching, and data fusion (merging radiological data with geo-referenced maps, digital imagery to provide better situational awareness). In this stride to progress, a significant amount of inter-disciplinary research and development has taken place-techniques and spin-offs from medical science (such as x-ray radiography and tomography), materials engineering (systematic planned studies on scintillators to optimize several qualities of a good scintillator, nanoparticle applications, quantum dots, and photonic crystals, just to name a few). No trend analysis of radiation detection systems would be complete without mentioning the unprecedented strategic position taken by the National Nuclear Security Administration (NNSA) to deter, detect, and interdict illicit trafficking in nuclear and other radioactive materials across international borders and through the global maritime transportation-the so-called second line of defense.

  17. Out-and-back {sup 13}C-{sup 13}C scalar transfers in protein resonance assignment by proton-detected solid-state NMR under ultra-fast MAS

    Energy Technology Data Exchange (ETDEWEB)

    Barbet-Massin, Emeline; Pell, Andrew J. [University of Lyon, CNRS/ENS Lyon/UCB Lyon 1, Centre de RMN a Tres Hauts Champs (France); Jaudzems, Kristaps [Latvian Institute of Organic Synthesis (Latvia); Franks, W. Trent; Retel, Joren S. [Leibniz-Institut fuer Molekulare Pharmakologie (Germany); Kotelovica, Svetlana; Akopjana, Inara; Tars, Kaspars [Biomedical Research and Study Center (Latvia); Emsley, Lyndon [University of Lyon, CNRS/ENS Lyon/UCB Lyon 1, Centre de RMN a Tres Hauts Champs (France); Oschkinat, Hartmut [Leibniz-Institut fuer Molekulare Pharmakologie (Germany); Lesage, Anne; Pintacuda, Guido, E-mail: guido.pintacuda@ens-lyon.fr [University of Lyon, CNRS/ENS Lyon/UCB Lyon 1, Centre de RMN a Tres Hauts Champs (France)

    2013-08-15

    We present here {sup 1}H-detected triple-resonance H/N/C experiments that incorporate CO-CA and CA-CB out-and-back scalar-transfer blocks optimized for robust resonance assignment in biosolids under ultra-fast magic-angle spinning (MAS). The first experiment, (H)(CO)CA(CO)NH, yields {sup 1}H-detected inter-residue correlations, in which we record the chemical shifts of the CA spins in the first indirect dimension while during the scalar-transfer delays the coherences are present only on the longer-lived CO spins. The second experiment, (H)(CA)CB(CA)NH, correlates the side-chain CB chemical shifts with the NH of the same residue. These high sensitivity experiments are demonstrated on both fully-protonated and 100 %-H{sup N} back-protonated perdeuterated microcrystalline samples of Acinetobacter phage 205 (AP205) capsids at 60 kHz MAS.

  18. Radiation detection using the color changes of lilac spodumene

    International Nuclear Information System (INIS)

    Oliveira, Raquel A.P.; Mello, Ana Carolina S.; Lima, Hestia R.B.R.; Campos, Simara Santos; Souza, Suzana O.

    2009-01-01

    The use of radiation in industrial processes currently offers several advantages in the field of sterilization of medical and pharmaceuticals products, the preservation of food, and a variety of other products widely used in modern society. A dosimetry of confidence is a key parameter for the quality assurance of radiation processing and the irradiated products. This work investigates dosimetric properties in natural spodumene, LiAlSi 2 O 6 , called kunzite, from Minas Gerais State, Brazil. After X irradiation on the samples in powder form was detected a change in color of the crystal where the dose received. This makes a possible viability of this material is applied in research on development of radiation detectors using the change in color of purple spodumene. (author)

  19. Ultrafast gas switching experiments

    International Nuclear Information System (INIS)

    Frost, C.A.; Martin, T.H.; Patterson, P.E.; Rinehart, L.F.; Rohwein, G.J.; Roose, L.D.; Aurand, J.F.; Buttram, M.T.

    1993-01-01

    We describe recent experiments which studied the physics of ultrafast gas breakdown under the extreme overvoltages which occur when a high pressure gas switch is pulse charged to hundreds of kV in 1 ns or less. The highly overvolted peaking gaps produce powerful electromagnetic pulses with risetimes Khz at > 100 kV/m E field

  20. PREFACE: Ultrafast and nonlinear optics in carbon nanomaterials

    Science.gov (United States)

    Kono, Junichiro

    2013-02-01

    Carbon-based nanomaterials—single-wall carbon nanotubes (SWCNTs) and graphene, in particular—have emerged in the last decade as novel low-dimensional systems with extraordinary properties. Because they are direct-bandgap systems, SWCNTs are one of the leading candidates to unify electronic and optical functions in nanoscale circuitry; their diameter-dependent bandgaps can be utilized for multi-wavelength devices. Graphene's ultrahigh carrier mobilities are promising for high-frequency electronic devices, while, at the same time, it is predicted to have ideal properties for terahertz generation and detection due to its unique zero-gap, zero-mass band structure. There have been a large number of basic optical studies on these materials, but most of them were performed in the weak-excitation, quasi-equilibrium regime. In order to probe and assess their performance characteristics as optoelectronic materials under device-operating conditions, it is crucial to strongly drive them and examine their optical properties in highly non-equilibrium situations and with ultrashot time resolution. In this section, the reader will find the latest results in this rapidly growing field of research. We have assembled contributions from some of the leading experts in ultrafast and nonlinear optical spectroscopy of carbon-based nanomaterials. Specific topics featured include: thermalization, cooling, and recombination dynamics of photo-generated carriers; stimulated emission, gain, and amplification; ultrafast photoluminescence; coherent phonon dynamics; exciton-phonon and exciton-plasmon interactions; exciton-exciton annihilation and Auger processes; spontaneous and stimulated emission of terahertz radiation; four-wave mixing and harmonic generation; ultrafast photocurrents; the AC Stark and Franz-Keldysh effects; and non-perturbative light-mater coupling. We would like to express our sincere thanks to those who contributed their latest results to this special section, and the

  1. EPR detection of foods preserved with ionizing radiation

    Science.gov (United States)

    Stachowicz, W.; Burlinska, G.; Michalik, J.

    1998-06-01

    The applicability of the epr technique for the detection of dried vegetables, mushrooms, some spices, flavour additives and some condiments preserved with ionizing radiation is discussed. The epr signals recorded after exposure to gamma rays and to beams of 10 MeV electrons from linac are stable, intense and specific enough as compared with those observed with nonirradiated samples and could be used for the detection of irradiation. However, stability of radiation induced epr signals produced in these foods depends on storage condition. No differences in shapes (spectral parameters) and intensities of the epr spectra recorded with samples exposed to the same doses of gamma rays ( 60Co) and 10 MeV electrons were observed

  2. EPR detection of foods preserved with ionizing radiation

    International Nuclear Information System (INIS)

    Stachowicz, W.; Burlinska, G.; Michalik, J.

    1998-01-01

    The applicability of the epr technique for the detection of dried vegetables, mushrooms, some spices, flavour additives and some condiments preserved with ionizing radiation is discussed. The epr signals recorded after exposure to gamma rays and to the beams of 10 MeV electrons from linac are stable, intense and specific enough as compared with those observed with nonirradiated samples and could be used for the detection of irradiation. However, stability of radiation induced epr signals produced in these foods depends on storage condition. No differences in shapes (spectral parameters) and intensities of the epr spectra recorded with samples exposed to the same doses of gamma rays ( 60 Co) and 10 MeV electrons were observed

  3. Position sensitive detection of neutrons in high radiation background field.

    Science.gov (United States)

    Vavrik, D; Jakubek, J; Pospisil, S; Vacik, J

    2014-01-01

    We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e(-) radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm(2)) spectroscopic Timepix detector adapted for neutron detection utilizing very thin (10)B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10(-4).

  4. EPR detection of foods preserved with ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Stachowicz, W.; Burlinska, G.; Michalik, J

    1998-06-01

    The applicability of the epr technique for the detection of dried vegetables, mushrooms, some spices, flavour additives and some condiments preserved with ionizing radiation is discussed. The epr signals recorded after exposure to gamma rays and to the beams of 10 MeV electrons from linac are stable, intense and specific enough as compared with those observed with nonirradiated samples and could be used for the detection of irradiation. However, stability of radiation induced epr signals produced in these foods depends on storage condition. No differences in shapes (spectral parameters) and intensities of the epr spectra recorded with samples exposed to the same doses of gamma rays ({sup 60}Co) and 10 MeV electrons were observed.

  5. Radiation Detection System for Prevention of Radiological and Nuclear Terrorism

    International Nuclear Information System (INIS)

    Kwak, Sung-Woo; Yoo, Ho-Sik; Jang, Sung-Sun; Kim, Jae-Kwang; Kim, Jung-Soo

    2007-01-01

    After the September 11 terrorist attack, the threat of a potential for a radiological or nuclear terrorist attack became more apparent. The threats relating to radiological or nuclear materials include a Radiological Dispersion Device (RDD), an Improved Nuclear Device (IND) or a State Nuclear Device (such as a Soviet manufactured suitcase nuclear weapon). For more effective countermeasures against the disaster, multilayer protection concept - prevention of smuggling of radioactive or nuclear material into our country through seaports or airports, detection and prevention of the threat materials in transit on a road, and prevention of their entry into a target building - is recommended. Due to different surrounding circumstances of where detection system is deployed, different types of radiation detection systems are required. There have been no studies on characteristics of detection equipment required under Korean specific conditions. This paper provides information on technical requirements of radiation detection system to achieve multi-layer countermeasures for the purpose of protecting the public and environment against radiological and nuclear terrorism

  6. Method for detecting radiation dose utilizing thermoluminescent material

    International Nuclear Information System (INIS)

    Miller, S.D.; McDonald, J.C.; Eichner, F.N.; Durham, J.S.

    1992-01-01

    The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material and then optically stimulating the thermoluminescent material by exposure to light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light. 5 figs

  7. Application of single-chip microcomputer in radiation detection

    International Nuclear Information System (INIS)

    Zhang Songshou

    1993-01-01

    The single-chip microcomputer has some advantages in many aspects for example the strong function, the small volume, the low-power, firmed and reliable. It is used widely in the control of industry, instrument, communication and machine, etc.. The paper introduces that the single-chip microcomputer is used in radiation detection, mostly including the use of control, linear, compensation, calculation, prefabricated change, improving precision and training

  8. Direct Characterization of Ultrafast Energy-Time Entangled Photon Pairs.

    Science.gov (United States)

    MacLean, Jean-Philippe W; Donohue, John M; Resch, Kevin J

    2018-02-02

    Energy-time entangled photons are critical in many quantum optical phenomena and have emerged as important elements in quantum information protocols. Entanglement in this degree of freedom often manifests itself on ultrafast time scales, making it very difficult to detect, whether one employs direct or interferometric techniques, as photon-counting detectors have insufficient time resolution. Here, we implement ultrafast photon counters based on nonlinear interactions and strong femtosecond laser pulses to probe energy-time entanglement in this important regime. Using this technique and single-photon spectrometers, we characterize all the spectral and temporal correlations of two entangled photons with femtosecond resolution. This enables the witnessing of energy-time entanglement using uncertainty relations and the direct observation of nonlocal dispersion cancellation on ultrafast time scales. These techniques are essential to understand and control the energy-time degree of freedom of light for ultrafast quantum optics.

  9. Additive Manufacturing Materials Study for Gaseous Radiation Detection

    Energy Technology Data Exchange (ETDEWEB)

    Steer, C.A.; Durose, A.; Boakes, J. [AWE Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

    2015-07-01

    Additive manufacturing (AM) techniques may lead to improvements in many areas of radiation detector construction; notably the rapid manufacturing time allows for a reduced time between prototype iterations. The additive nature of the technique results in a granular microstructure which may be permeable to ingress by atmospheric gases and make it unsuitable for gaseous radiation detector development. In this study we consider the application of AM to the construction of enclosures and frames for wire-based gaseous radiation tracking detectors. We have focussed on oxygen impurity ingress as a measure of the permeability of the enclosure, and the gas charging and discharging curves of several simplistic enclosure shapes are reported. A prototype wire-frame is also presented to examine structural strength and positional accuracy of an AM produced frame. We lastly discuss the implications of this study for AM based radiation detection technology as a diagnostic tool for incident response scenarios, such as the interrogation of a suspect radiation-emitting package. (authors)

  10. Additive Manufacturing Materials Study for Gaseous Radiation Detection

    International Nuclear Information System (INIS)

    Steer, C.A.; Durose, A.; Boakes, J.

    2015-01-01

    Additive manufacturing (AM) techniques may lead to improvements in many areas of radiation detector construction; notably the rapid manufacturing time allows for a reduced time between prototype iterations. The additive nature of the technique results in a granular microstructure which may be permeable to ingress by atmospheric gases and make it unsuitable for gaseous radiation detector development. In this study we consider the application of AM to the construction of enclosures and frames for wire-based gaseous radiation tracking detectors. We have focussed on oxygen impurity ingress as a measure of the permeability of the enclosure, and the gas charging and discharging curves of several simplistic enclosure shapes are reported. A prototype wire-frame is also presented to examine structural strength and positional accuracy of an AM produced frame. We lastly discuss the implications of this study for AM based radiation detection technology as a diagnostic tool for incident response scenarios, such as the interrogation of a suspect radiation-emitting package. (authors)

  11. Detection and spectral measurements of coherent synchrotron radiation at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Christopher

    2010-02-15

    The operation of high-gain free-electron laser (FEL) underlies tremendous demands on high quality electron beams with high peak currents. At the Free-Electron-Laser in Hamburg (FLASH), two magnetic bunch compressors are used to compress the electron bunches longitudinally. In the bunch compressor magnets, these short electron bunches generate coherent synchrotron radiation (CSR). This CSR contains information on the longitudinal bunch profile, which is relevant for driving an FEL. In order to investigate coherent synchrotron radiation at the second bunch compressor BC3 at FLASH, a new setup behind the last dipole was installed. For the detection of coherent synchrotron radiation, which is emitted in the infrared regime, pyroelectric detectors were used. These pyroelectric detectors have been calibrated at the free-electron laser FELIX in the wavelength range from 5 {mu}m to 110 {mu}m. For characterisation of the emitted radiation, a transverse scanning device was used to measure the transverse intensity distribution. Various transmission filters were used to obtain additional information about the spectral content. In order to get spectral information with high resolution over a wide wavelength range, a rotating mirror spectrometer using reflective blazed gratings was installed. Using this spectrometer, the first spectral measurements of coherent synchrotron radiation at FLASH in a wavelength range from 10 {mu}m to 160 {mu}m were done. (orig.)

  12. Detection and spectral measurements of coherent synchrotron radiation at FLASH

    International Nuclear Information System (INIS)

    Behrens, Christopher

    2010-02-01

    The operation of high-gain free-electron laser (FEL) underlies tremendous demands on high quality electron beams with high peak currents. At the Free-Electron-Laser in Hamburg (FLASH), two magnetic bunch compressors are used to compress the electron bunches longitudinally. In the bunch compressor magnets, these short electron bunches generate coherent synchrotron radiation (CSR). This CSR contains information on the longitudinal bunch profile, which is relevant for driving an FEL. In order to investigate coherent synchrotron radiation at the second bunch compressor BC3 at FLASH, a new setup behind the last dipole was installed. For the detection of coherent synchrotron radiation, which is emitted in the infrared regime, pyroelectric detectors were used. These pyroelectric detectors have been calibrated at the free-electron laser FELIX in the wavelength range from 5 μm to 110 μm. For characterisation of the emitted radiation, a transverse scanning device was used to measure the transverse intensity distribution. Various transmission filters were used to obtain additional information about the spectral content. In order to get spectral information with high resolution over a wide wavelength range, a rotating mirror spectrometer using reflective blazed gratings was installed. Using this spectrometer, the first spectral measurements of coherent synchrotron radiation at FLASH in a wavelength range from 10 μm to 160 μm were done. (orig.)

  13. Exploiting Novel Radiation-Induced Electromagnetic Material Changes for Remote Detection and Monitoring: Final Progress Report

    Science.gov (United States)

    2016-04-01

    Exploiting Novel Radiation -Induced Electromagnetic Material Changes for Remote Detection and Monitoring: Final Progress Report Distribution...assess the effects of ionizing radiation on at least three classes of electromagnetic materials. The proposed approach for radiation detection was...that was desired to be monitored remotely. Microwave or low millimeter wave electromagnetic radiation would be used to interrogate the device

  14. Detection of gravitational radiation by the Doppler tracking of spacecraft

    International Nuclear Information System (INIS)

    Mashhoon, B.

    1979-01-01

    It has been suggested that the residual Doppler shift in the precision electromagnetic tracking of spacecraft be used to search for gravitational radiation that may be incident on the Earth-spacecraft system. The influence of a gravitational wave on the Doppler shift is calculated, and it is found that the residual shift is dominated by two terms: one is due to the passage of electromagnetic waves through the gravitational radiation field, and the other depends on the change in the relative velocity of the Earth and the spacecraft caused by the external wave. A detailed analysis is given of the influence of gravitational radiation on a binary system with an orbital size small compared to the wavelength of the incident radiation. It is shown that, as a consequence of the interaction with the external wave, the system makes a transition from one Keplerian orbit into another which, in general, has a different energy and angular momentum. It is therefore proposed to search for such effects in the solar system. Observations of the orbit of an artificial Earth satellite, the lunar orbit, and especially the planetary orbits offer exciting possibilities for the detection of gravitational waves of various wavelengths. From the results of the lunar laser ranging experiment and the range measurement to Mars, certain interesting limits may be established on the frequency of incidence of gravitational waves of a given flux on the Earth-Moon and the Earth-Mars systems. This is followed by a brief and preliminary analysis of the possibility of detecting gravitational radiation by measuring a residual secular Doppler shift in the satellite-to-satellite Doppler tracking of two counterorbiting drag-free spacecraft around the Earth as in the Van Patten-Everitt experiment

  15. A dual-sided coded-aperture radiation detection system

    International Nuclear Information System (INIS)

    Penny, R.D.; Hood, W.E.; Polichar, R.M.; Cardone, F.H.; Chavez, L.G.; Grubbs, S.G.; Huntley, B.P.; Kuharski, R.A.; Shyffer, R.T.; Fabris, L.; Ziock, K.P.; Labov, S.E.; Nelson, K.

    2011-01-01

    We report the development of a large-area, mobile, coded-aperture radiation imaging system for localizing compact radioactive sources in three dimensions while rejecting distributed background. The 3D Stand-Off Radiation Detection System (SORDS-3D) has been tested at speeds up to 95 km/h and has detected and located sources in the millicurie range at distances of over 100 m. Radiation data are imaged to a geospatially mapped world grid with a nominal 1.25- to 2.5-m pixel pitch at distances out to 120 m on either side of the platform. Source elevation is also extracted. Imaged radiation alarms are superimposed on a side-facing video log that can be played back for direct localization of sources in buildings in urban environments. The system utilizes a 37-element array of 5x5x50 cm 3 cesium-iodide (sodium) detectors. Scintillation light is collected by a pair of photomultiplier tubes placed at either end of each detector, with the detectors achieving an energy resolution of 6.15% FWHM (662 keV) and a position resolution along their length of 5 cm FWHM. The imaging system generates a dual-sided two-dimensional image allowing users to efficiently survey a large area. Imaged radiation data and raw spectra are forwarded to the RadioNuclide Analysis Kit (RNAK), developed by our collaborators, for isotope ID. An intuitive real-time display aids users in performing searches. Detector calibration is dynamically maintained by monitoring the potassium-40 peak and digitally adjusting individual detector gains. We have recently realized improvements, both in isotope identification and in distinguishing compact sources from background, through the installation of optimal-filter reconstruction kernels.

  16. Radiation detection and situation management by distributed sensor networks

    International Nuclear Information System (INIS)

    Jan, Frigo; Mielke, Angela; Cai, D. Michael

    2009-01-01

    Detection of radioactive materials in an urban environment usually requires large, portal-monitor-style radiation detectors. However, this may not be a practical solution in many transport scenarios. Alternatively, a distributed sensor network (DSN) could complement portal-style detection of radiological materials through the implementation of arrays of low cost, small heterogeneous sensors with the ability to detect the presence of radioactive materials in a moving vehicle over a specific region. In this paper, we report on the use of a heterogeneous, wireless, distributed sensor network for traffic monitoring in a field demonstration. Through wireless communications, the energy spectra from different radiation detectors are combined to improve the detection confidence. In addition, the DSN exploits other sensor technologies and algorithms to provide additional information about the vehicle, such as its speed, location, class (e.g. car, truck), and license plate number. The sensors are in-situ and data is processed in real-time at each node. Relevant information from each node is sent to a base station computer which is used to assess the movement of radioactive materials

  17. Ultrafast dynamics of Coulomb correlated excitons in GaAs quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Mycek, M.A. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

    1995-12-01

    The author measures the transient nonlinear optical response of room temperature excitons in gallium arsenide quantum wells via multi-wave mixing experiments. The dynamics of the resonantly excited excitons is directly reflected by the ultrafast decay of the induced nonlinear polarization, which radiates the detected multi-wave mixing signal. She characterizes this ultrafast coherent emission in both amplitude and phase, using time- and frequency-domain measurement techniques, to better understand the role of Coulomb correlation in these systems. To interpret the experimental results, the nonlinear optical response of a dense medium is calculated using a model including Coulomb interaction. She contributes three new elements to previous theoretical and experimental studies of these systems. First, surpassing traditional time-integrated measurements, she temporally resolves the amplitude of the ultrafast coherent emission. Second, in addition to measuring the third-order four-wave mixing signal, she also investigates the fifth-order six-wave mixing response. Third, she characterizes the ultrafast phase dynamics of the nonlinear emission using interferometric techniques with an unprecedented resolution of approximately 140 attoseconds. The author finds that effects arising from Coulomb correlation dominate the nonlinear optical response when the density of excitons falls below 3 {times} 10{sup 11} cm{sup {minus}2}, the saturation density. These signatures of Coulomb correlation are investigated for increasing excitation density to gradually screen the interactions and test the validity of the model for dense media. The results are found to be qualitatively consistent with both the predictions of the model and with numerical solutions to the semiconductor Bloch equations. Importantly, the results also indicate current experimental and theoretical limitations, which should be addressed in future research.

  18. Particle and photon detection for a neutron radiative decay experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gentile, T.R. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)], E-mail: thomas.gentile@nist.gov; Dewey, M.S.; Mumm, H.P.; Nico, J.S.; Thompson, A.K. [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Chupp, T.E. [University of Michigan, Ann Arbor, MI 48109 (United States); Cooper, R.L. [University of Michigan, Ann Arbor, MI 48109 (United States)], E-mail: cooperrl@umich.edu; Fisher, B.M.; Kremsky, I.; Wietfeldt, F.E. [Tulane University, New Orleans, LA 70118 (United States); Kiriluk, K.G.; Beise, E.J. [University of Maryland, College Park, MD 20742 (United States)

    2007-08-21

    We present the particle and photon detection methods employed in a program to observe neutron radiative beta-decay. The experiment is located at the NG-6 beam line at the National Institute of Standards and Technology Center for Neutron Research. Electrons and protons are guided by a 4.6 T magnetic field and detected by a silicon surface barrier detector. Photons with energies between 15 and 750 keV are registered by a detector consisting of a bismuth germanate scintillator coupled to a large area avalanche photodiode. The photon detector operates at a temperature near 80 K in the bore of a superconducting magnet. We discuss CsI as an alternative scintillator, and avalanche photodiodes for direct detection of photons in the 0.1-10 keV range.

  19. Assessment of Radiation Background Variation for Moving Detection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James Christopher [Los Alamos National Laboratory; Rennie, John Alan [Los Alamos National Laboratory; Toevs, James Waldo [Los Alamos National Laboratory; Wallace, Darrin J. [Los Alamos National Laboratory; Abhold, Mark Edward [Los Alamos National Laboratory

    2015-07-13

    The introduction points out that radiation backgrounds fluctuate across very short distances: factors include geology, soil composition, altitude, building structures, topography, and other manmade structures; and asphalt and concrete can vary significantly over short distances. Brief descriptions are given of the detection system, experimental setup, and background variation measurements. It is concluded that positive and negative gradients can greatly reduce the detection sensitivity of an MDS: negative gradients create opportunities for false negatives (nondetection), and positive gradients create a potentially unacceptable FAR (above 1%); the location of use for mobile detection is important to understand; spectroscopic systems provide more information for screening out false alarms and may be preferred for mobile use; and mobile monitor testing at LANL accounts for expected variations in the background.

  20. A novel mobile system for radiation detection and monitoring

    Science.gov (United States)

    Biafore, Mauro

    2014-05-01

    A novel mobile system for real time, wide area radiation surveillance has been developed within the REWARD project, financed within the FP7 programme, theme SEC-2011.1.5-1 (Development of detection capabilities of difficult to detect radioactive sources and nuclear materials - Capability Project). The REWARD sensing units are small, mobile portable units with low energy consumption, which consist of new miniaturized solid-state radiation sensors: a CdZnTe detector for gamma radiation and a high efficiency neutron detector based on novel silicon technologies. The sensing unit is integrated by a wireless communication interface to send the data remotely to a monitoring base station as well as a GPS system to calculate the position of the tag. The system also incorporates middleware and high-level software to provide web-service interfaces for the exchange of information. A central monitoring and decision support system has been designed to process the data from the sensing units and to compare them with historical record in order to generate an alarm when an abnormal situation is detected. A security framework ensures protection against unauthorized access to the network and data, ensuring the privacy of the communications and contributing to the overall robustness and reliability of the REWARD system. The REWARD system has been designed for many different scenarios such as nuclear terrorism threats, lost radioactive sources, radioactive contamination or nuclear accidents. It can be deployed in emergency units and in general in any type of mobile or static equipment, but also inside public/private buildings or infrastructures. The complete system is scalable in terms of complexity and cost and offers very high precision on both the measurement and the location of the radiation. The modularity and flexibility of the system allows for a realistic introduction to the market. Authorities may start with a basic, low cost system and increase the complexity based on their

  1. Geiger-mueller radiation detector with means for detecting and indicating the existence of radiation overload

    International Nuclear Information System (INIS)

    Kovacs, T.; Mills, A.P.; Pfeiffer, L.N.

    1981-01-01

    When subjected to radiation overload existing geiger-mueller counters may give an erroneously low reading, resulting in possible hazard to personnel. The instant invention discloses simple and inexpensive apparatus to remedy this dangerous shortcoming. Depending on the geometry of the detector tube, two possible failure modes have been identified, and circuitry is disclosed to detect the existence of these respective failure modes. The disclosed apparatus indicates the absence of an overload condition, in addition to signaling, by both visible and audible means, the existence of excessive radiation that might result in erroneously low reading of the geiger-mueller counter

  2. Radiation sensitive devices and systems for detection of radioactive materials and related methods

    Science.gov (United States)

    Kotter, Dale K

    2014-12-02

    Radiation sensitive devices include a substrate comprising a radiation sensitive material and a plurality of resonance elements coupled to the substrate. Each resonance element is configured to resonate responsive to non-ionizing incident radiation. Systems for detecting radiation from a special nuclear material include a radiation sensitive device and a sensor located remotely from the radiation sensitive device and configured to measure an output signal from the radiation sensitive device. In such systems, the radiation sensitive device includes a radiation sensitive material and a plurality of resonance elements positioned on the radiation sensitive material. Methods for detecting a presence of a special nuclear material include positioning a radiation sensitive device in a location where special nuclear materials are to be detected and remotely interrogating the radiation sensitive device with a sensor.

  3. Ultrafast laser-semiconductor interactions

    International Nuclear Information System (INIS)

    Schile, L.A.

    1996-01-01

    Studies of the ultrafast (< 100 fs) interactions of infrared, sub-100 fs laser pulses with IR, photosensitive semiconductor materials InGaAs, InSb, and HgCdTe are reported. Both the carrier dynamics and the associated Terahertz radiation from these materials are discussed. The most recent developments of femtosecond (< 100 fs) Optical Parametric Oscillators (OPO) has extended the wavelength range from the visible to 5.2 μm. The photogenerated semiconductor free carrier dynamics are determined in the 77 to 300 degrees K temperature range using the Transmission Correlation Peak (TCP) method. The electron-phonon scattering times are typically 200 - 600 fs. Depending upon the material composition and substrate on which the IR crystalline materials are deposited, the nonlinear TCP absorption gives recombination rates as fast as 10's of picoseconds. For the HgCdTe, there exists a 400 fs electron-phonon scattering process along with a much longer 3600 fs loss process. Studies of the interactions of these ultrashort laser pulses with semiconductors produce Terahertz (Thz) radiative pulses. With undoped InSb, there is a substantial change in the spectral content of this THz radiation between 80 - 260 degrees K while the spectrum of Te-doped InSb remains nearly unchanged, an effect attributed to its mobility being dominated by impurity scattering. At 80 degrees K, the terahertz radiation from undoped InSb is dependent on wavelength, with both a higher frequency spectrum and much larger amplitudes generated at longer wavelengths. No such effect is observed at 260 degrees K. Finally, new results on the dependence of the emitted THz radiation on the InSb crystal's orientation is presented

  4. Radiation and detection of gravitational waves in laboratory conditions

    International Nuclear Information System (INIS)

    Bogolyubov, P.N.; Pisarev, A.F.; Shavokhina, N.S.

    1981-01-01

    Two variants are proposed and analyzed for an experiment on radiation and detection of gravitational waves in laboratory conditions in the optical and superhigh frequency range (band). In the first variant the laser light is parametrically transformed to the gravitational wave in the optical-inhomogeneous medium. The gravitational flux produced is registered by the inverse parametric transformation of the gravitational to light wave. In the second variant the radiation of gravitational waves is realized through hypersonic oscillations in piezocrystals, and the reception of waves is made by the superconducting coaxial resonator in which the gravitational wave resonantly transforms into the electromag= . netic wave. The analysis performed testifies to the possibility of an experiment of this type at the present time [ru

  5. Neutron and/or gamma radiation detecting system

    International Nuclear Information System (INIS)

    Cerff, K.

    1985-01-01

    A large reception surface for the radiation to be detected is formed on a body of scintillation material (ZnS-AG with B matrix) which is adapted to convert neutron or gamma radiation into light energy. A large number of fiber light conductors is embedded in the body of scintillation material such that the fibers extend essentially parallel and fully across the reception surface of the body of scintillation material. The light energy, upon propagation along the fiber light conductors, is coupled into the conductors along the surface of the fibers which are unisotropic. This arrangement permits the use of unisotropic light conductor systems which provide for a separation of light collecting and light transmitting functions which results in a substantial reduction of light absorption losses during light transmission so that most of the light energy coupled into the fiber light conductors reaches the optoelectronic amplifier coupled to the end of the light conductors. (orig./HP) [de

  6. Principles of radiation interaction in matter and detection

    CERN Document Server

    Leroy, Claude

    2016-01-01

    The fourth edition of this book has been widely revised. It includes additional chapters and some sections are complemented with either new ones or an extension of their content. In this latest edition a complete treatment of the physics and properties of semiconductors is presented, covering transport phenomena in semiconductors, scattering mechanisms, radiation effects and displacement damages. Furthermore, this edition presents a comprehensive treatment of the Coulomb scattering on screened nuclear potentials resulting from electrons, protons, light- and heavy-ions — ranging from (very) low up to ultra-relativistic kinetic energies — and allowing one to derive the corresponding NIEL (non-ionizing energy-loss) doses deposited in any material. The contents are organized into two parts: Chapters 1 to 7 cover Particle Interactions and Displacement Damage while the remaining chapters focus on Radiation Environments and Particle Detection. This book can serve as reference for graduate students and final-y...

  7. Ultrafast magnetization dynamics

    OpenAIRE

    Woodford, Simon

    2008-01-01

    This thesis addresses ultrafast magnetization dynamics from a theoretical perspective. The manipulation of magnetization using the inverse Faraday effect has been studied, as well as magnetic relaxation processes in quantum dots. The inverse Faraday effect – the generation of a magnetic field by nonresonant, circularly polarized light – offers the possibility to control and reverse magnetization on a timescale of a few hundred femtoseconds. This is important both for the technological advant...

  8. Detection of electromagnetic radiation using micromechanical multiple quantum wells structures

    Science.gov (United States)

    Datskos, Panagiotis G [Knoxville, TN; Rajic, Slobodan [Knoxville, TN; Datskou, Irene [Knoxville, TN

    2007-07-17

    An apparatus and method for detecting electromagnetic radiation employs a deflectable micromechanical apparatus incorporating multiple quantum wells structures. When photons strike the quantum-well structure, physical stresses are created within the sensor, similar to a "bimetallic effect." The stresses cause the sensor to bend. The extent of deflection of the sensor can be measured through any of a variety of conventional means to provide a measurement of the photons striking the sensor. A large number of such sensors can be arranged in a two-dimensional array to provide imaging capability.

  9. Improvements in or relating to radiation detection arrangements

    International Nuclear Information System (INIS)

    Davis, G.P.

    1977-01-01

    A radiation detection arrangement is described that that comprises a number of scintillator devices, and a single multi-channel photomultiplier tube. Light from the scintillator devices is incident on the photocathode through an entrance window in the tube and multiplier entrance separating means are provided whereby light from each of the devices is made to be incident upon the channel entrances of photomultiplier tube. Various geometrical forms for the scintillator devices are described. This arrangement avoids the use of large number of small photomultiplier tubes, which is expensive and gives rise to difficulties in stacking the tubes in closely spaced side-by-side relationship. (U.K.)

  10. Ultrafast surface-enhanced Raman spectroscopy.

    Science.gov (United States)

    Keller, Emily L; Brandt, Nathaniel C; Cassabaum, Alyssa A; Frontiera, Renee R

    2015-08-07

    Ultrafast surface-enhanced Raman spectroscopy (SERS) with pico- and femtosecond time resolution has the ability to elucidate the mechanisms by which plasmons mediate chemical reactions. Here we review three important technological advances in these new methodologies, and discuss their prospects for applications in areas including plasmon-induced chemistry and sensing at very low limits of detection. Surface enhancement, arising from plasmonic materials, has been successfully incorporated with stimulated Raman techniques such as femtosecond stimulated Raman spectroscopy (FSRS) and coherent anti-Stokes Raman spectroscopy (CARS). These techniques are capable of time-resolved measurement on the femtosecond and picosecond time scale and can be used to follow the dynamics of molecules reacting near plasmonic surfaces. We discuss the potential application of ultrafast SERS techniques to probe plasmon-mediated processes, such as H2 dissociation and solar steam production. Additionally, we discuss the possibilities for high sensitivity SERS sensing using these stimulated Raman spectroscopies.

  11. Ticor-based scintillation detectors for detection of mixed radiation

    CERN Document Server

    Litvinov, L A; Kolner, V B; Ryzhikov, V D; Volkov, V G; Tarasov, V A; Zelenskaya, O V

    2002-01-01

    Detection of mixed radiation of thermal neutrons and gamma-rays have been realized using a new ceramic material based on small-crystalline long-wave scintillator alpha-Al sub 2 O sub 3 :Ti (Ticor) and lithium fluoride. Characteristics are presented for scintillators with Si-PIN-PD type photoreceivers and PMT under sup 2 sup 3 sup 9 Pu alpha-particles, sup 2 sup 0 sup 7 Bi internal conversion electrons,as well as sup 2 sup 4 sup 1 Am and sup 1 sup 3 sup 7 Cs gamma-quanta. Detection efficiency of thermal neutron is estimated for composite materials based on Ticor and lithium fluoride.

  12. Optimal Background Attenuation for Fielded Radiation Detection Systems

    International Nuclear Information System (INIS)

    Robinson, Sean M.; Kaye, William R.; Schweppe, John E.; Siciliano, Edward R.

    2006-01-01

    Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background. This is particularly true in the case of Radiation Portal Monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to terrestrial background from the surrounding area. A low background is desired in most cases, especially when the background noise is of comparable strength to the signal of interest. The problem of shielding a generalized RPM from terrestrial background is considered. Various detector and shielding scenarios are modeled with the Monte-Carlo N Particle (MCNP) computer code. Amounts of nominal-density shielding needed to attenuate the terrestrial background to varying degrees are given, along with optimal shielding geometry to be used in areas where natural shielding is limited, and where radiation detection must occur in the presence of natural background. Common shielding solutions such as steel plating are evaluated based on the signal to noise ratio and the benefits are weighed against the incremental cost.

  13. Radiation transmission type pipe wall thinning detection device and measuring instruments utilizing ionizing radiation

    International Nuclear Information System (INIS)

    Higashi, Yasuhiko

    2009-01-01

    We developed the device to detect thinning of pipe thorough heat insulation in Power Plant, etc, even while the plant is under operation. It is necessary to test many parts of many pipes for pipe wall thinning management, but it is difficult within a limited time of the routine test. This device consists of detector and radiation source, which can detect the pipe (less than 500 mm in external diameter, less than 50 mm in thickness) with 1.6%-reproducibility (in a few-minutes measurement), based on the attenuation rate. Operation is easy and effective without removing the heat insulation. We will expand this thinning detection system, and contribute the safety of the Plant. (author)

  14. Piezoelectric Materials Under Natural and Man-Made Radiation: The Potential for Direct Radiation Detection

    Science.gov (United States)

    Wart, Megan; Simpson, Evan; Flaska, Marek

    2018-01-01

    Radiation detection systems used for monitoring long term waste storage need to be compact, rugged, and have low or no power requirements. By using piezoelectric materials it may be possible to create a reliable self-powered radiation detection system. To determine the feasibility of this approach, the electrical signal response of the piezoelectric materials to radiation must be characterized. To do so, an experimental geometry has been designed and a neutron source has been chosen as described in this paper, which will be used to irradiate a uranium foil for producing fission fragments. These future experiments will be aimed at finding the threshold of exposure of lead zirconate titanate (PZT) plates needed to produce and electrical signal. Based on the proposed experimental geometry the thermal neutron beam-line at the Breazeale Reactor at The Pennsylvania State University will be used as the neutron source. The uranium foil and neutron source will be able to supply a maximum flux of 1.5e5 fission fragments/second*cm2 to each of the PZT plates.

  15. Piezoelectric Materials Under Natural and Man-Made Radiation: The Potential for Direct Radiation Detection

    Directory of Open Access Journals (Sweden)

    Wart Megan

    2018-01-01

    Full Text Available Radiation detection systems used for monitoring long term waste storage need to be compact, rugged, and have low or no power requirements. By using piezoelectric materials it may be possible to create a reliable self-powered radiation detection system. To determine the feasibility of this approach, the electrical signal response of the piezoelectric materials to radiation must be characterized. To do so, an experimental geometry has been designed and a neutron source has been chosen as described in this paper, which will be used to irradiate a uranium foil for producing fission fragments. These future experiments will be aimed at finding the threshold of exposure of lead zirconate titanate (PZT plates needed to produce and electrical signal. Based on the proposed experimental geometry the thermal neutron beam-line at the Breazeale Reactor at The Pennsylvania State University will be used as the neutron source. The uranium foil and neutron source will be able to supply a maximum flux of 1.5e5 fission fragments/second*cm2 to each of the PZT plates.

  16. An ideal scintillator – ZnO:Sc for sub-nanosecond pulsed radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kan, E-mail: zhangkan8414@163.com [Northwest Institute of Nuclear Technology, Xi’an 710024 (China); Ouyang, Xiaoping [Northwest Institute of Nuclear Technology, Xi’an 710024 (China); Xi’an Jiaotong University, Xi’an 710049 (China); Song, Zhaohui; Han, Hetong [Northwest Institute of Nuclear Technology, Xi’an 710024 (China); Zuo, Yanbin [China Nonferrous Metal Guilin Research Institute of Geology for Mineral Resource, Guilin 541004 (China); Guan, Xingyin [Northwest Institute of Nuclear Technology, Xi’an 710024 (China); Xi’an Jiaotong University, Xi’an 710049 (China); Tan, Xinjian; Zhang, Zichuan; Liu, Junhong [Northwest Institute of Nuclear Technology, Xi’an 710024 (China)

    2014-08-21

    ZnO-based scintillators are particularly well suited for use as ultrafast pulsed radiation detectors which have shown broad application prospects in various fields such as the inertial confinement fusion (ICF) diagnosis, the nuclear reaction mechanism, etc. Using the hydro-thermal method, a ZnO single-crystal doped with Scandium (ZnO:Sc) sample was prepared. As a new ZnO-based scintillator, the scintillation characteristics of ZnO:Sc have not been reported previously. In this paper, optical and scintillation characteristics of ZnO:Sc single-crystal were studied. Also a scintillation detector based on ZnO:Sc was designed. Excited by the alpha-particle, the rise time of ZnO:Sc detectors was from 162.5 to 170.7 ps, and the fall time was from 300.4 to 328.8 ps.

  17. An ideal scintillator – ZnO:Sc for sub-nanosecond pulsed radiation detection

    International Nuclear Information System (INIS)

    Zhang, Kan; Ouyang, Xiaoping; Song, Zhaohui; Han, Hetong; Zuo, Yanbin; Guan, Xingyin; Tan, Xinjian; Zhang, Zichuan; Liu, Junhong

    2014-01-01

    ZnO-based scintillators are particularly well suited for use as ultrafast pulsed radiation detectors which have shown broad application prospects in various fields such as the inertial confinement fusion (ICF) diagnosis, the nuclear reaction mechanism, etc. Using the hydro-thermal method, a ZnO single-crystal doped with Scandium (ZnO:Sc) sample was prepared. As a new ZnO-based scintillator, the scintillation characteristics of ZnO:Sc have not been reported previously. In this paper, optical and scintillation characteristics of ZnO:Sc single-crystal were studied. Also a scintillation detector based on ZnO:Sc was designed. Excited by the alpha-particle, the rise time of ZnO:Sc detectors was from 162.5 to 170.7 ps, and the fall time was from 300.4 to 328.8 ps

  18. In-Situ Radiation Detection Demonstration Final Report

    International Nuclear Information System (INIS)

    Mohagheghi, Amir H.; Reese, Robert; Miller, David R.; Miller, Mark Laverne; Duce, Stephen

    2000-01-01

    The Department of Defense (DoD) has hundreds of facilities where radioactive materials have been used or are being used, including firing ranges, low-level radioactive waste disposal areas, and areas where past activities have resulted in environmental contamination. Affected sites range in size from a few acres to square miles. Impact to the DoD comes through military base closure and release to the public. It is important that radioactive contaminants are remediated to levels that result in acceptable risk to the public. Remediation requires characterization studies, e.g., sampling and surveys, to define the affected areas, removal actions, and final confirmatory sampling and surveys. Characterization of surface contamination concentrations has historically been performed using extensive soil sampling programs in conjunction with surface radiation surveys conducted with hand-held radiation monitoring equipment. Sampling is required within the suspect affected area and a large buffer area. Surface soil contaminant characterization using soil sampling and hand held monitoring are costly, time consuming, and result in long delays between submission of samples for analysis and obtaining of final results. This project took an existing, proven radiation survey technology that has had limited exposure and improved its capabilities by documenting correlation factors for various detector/radionuclide geometries that commonly occur in field surveys. With this tool, one can perform characterization and final release surveys much more quickly than is currently possible, and have detection limits that are as good as or better than current technology. This paper will discuss the capabilities of a large area plastic scintillation detector used in conjunction with a global positioning system (GPS) to improve site characterization, remediation, and final clearance surveys of the radioactively contaminated site. Survey results can rapidly identify areas that require remediation as

  19. Drone Detects Hotspots of Radiation and CO2 Outgassing

    Science.gov (United States)

    Takac, M.; Kletetschka, G.

    2016-12-01

    Market availability of environmental sensors and drones allow drones to become part of the education activities promoting environmental science both in high schools and grade schools. Here we provide one mode of drone operation for potential use in educational framework.Drone can carry devices that are capable of measuring various parameters of the environment. Commercial radiation and gas (CO2) sensors can be attached to the commercial drone. Our specific drone acquired data set of CO2 measurements over the natural outgassing of CO2 and another set of measurements over old uranium mine. Measurements of CO2 gave a poor signal to noise ratio. Its sensitivity, however, was enough to detect an increase in CO2 in the closed room with humans present compared to the fresh air outside. We could measure an increase of CO2 when directly over the source of natural CO2 outburst. Our data showed that CO2 concentration quickly dilutes in air few meters from the source to concentrations that are within the noise limit. However, the radiation measurements provided a map that correlates well with radiation survey obtained by ground measurements with more sophisticated instrument. We used the most common conventional drone, which is on the market and highly effective personal dosimeter, which can also be used for fire and rescue for its durability. Experimental field measurements were done at Třebsko site, where a map of radioactivity using standard spot measurements was already done. A field experiment was done in winter months when demand for the drone was higher due to cold and wet weather. We tested profiles and height versus the intensity of the recorded signal measurements. We consulted our results and ability to measure radioactivity with the regional fire-fighting units headquarters and verify the applicability and use of this technology for their needs.

  20. Energy nonlinearity in radiation detection materials: Causes and consequences

    International Nuclear Information System (INIS)

    Jaffe, J.E.; Jordan, D.V.; Peurrung, A.J.

    2007-01-01

    The phenomenology and present theoretical understanding of energy nonlinearity (nonproportionality) in radiation detection materials is reviewed, with emphasis on gamma-ray spectroscopy. Scintillators display varying degrees and patterns of nonlinearity, while semiconductor detectors are extremely linear, and gas detectors show a characteristic form of nonproportionality associated with core levels. The relation between nonlinear response (to both primary particles and secondary electrons) and spectrometer resolution is also discussed. We review the qualitative ideas about the origin of nonlinearity in scintillators that have been proposed to date, with emphasis on transport and recombination of electronic excitations. Recent computational and experimental work on the basic physics of scintillators is leading towards a better understanding of energy nonlinearity and should result in new, more linear scintillator materials in the near future

  1. Present status of fuel motion detection by radiation

    International Nuclear Information System (INIS)

    Sumita, Kenji; Mizuta, Hiroshi; Ishizuka, Makoto; Ara, Katsuyuki; Nakata, Hirokatsu.

    1978-05-01

    In reactor safety research, it is important to know transient fuel behavior under accidental conditions. Transient histories such as temperature and axial expansion of fuel and cladding and internal pressure of fuel rod are thus measured in experiments simulating accidents. If fuel motion could then be observed during and after fuel failure, this would greatly make for fuel behavior research. The present status is reviewed of fuel motion detections by radiations such as neutron, γ-ray and X-ray, including the principle and system. A neutron hodoscope among them is used already with practical results in in-reactor safety experiments of sodium-cooled fast breeder reactor. So, this is described in detail and its conceptual design as applied to the NSRR is presented. (auth.)

  2. 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)

  3. IAEA eLearning Program: The Use of Radiation Detection Instruments

    International Nuclear Information System (INIS)

    2010-01-01

    This CD-ROM contains a computer based training on Radiation Detection Techniques for Nuclear Security Applications. The IAEA Nuclear Security eLearning tool offers computer based training to Frontline Officers to improve their understanding about key elements of the use of radiation detection instruments. The eLearning program prepares Frontline Officers for the IAEA Detection and Response Frontline Officer course

  4. Ultrafast palladium diffusion in germanium

    KAUST Repository

    Tahini, Hassan Ali

    2015-01-01

    The slow transport of dopants through crystal lattices has hindered the development of novel devices. Typically atoms are contained within deep potential energy wells which necessitates multiple attempts to hop between minimum energy positions. This is because the bonds that constrain atoms are strongest at the minimum positions. As they hop between sites the bonds must be broken, only to re-form as the atoms slide into adjacent minima. Here we demonstrate that the Pd atoms introduced into the Ge lattice behave differently. They retain bonds as the atoms shift across so that at the energy maximum between sites Pd still exhibits strong bonding characteristics. This reduces the energy maximum to almost nothing (a migration energy of only 0.03 eV) and means that the transport of Pd through the Ge lattice is ultrafast. We scrutinize the bonding characteristics at the atomic level using quantum mechanical simulation tools and demonstrate why Pd behaves so differently to other metals we investigated (i.e. Li, Cu, Ag, Pt and Au). Consequently, this fundamental understanding can be extended to systems where extremely rapid diffusion is desired, such as radiation sensors, batteries and solid oxide fuel cells.

  5. Ultrafast THz saturable absorption in doped semiconductors at room temperature

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hoffmann, M. V.

    2011-01-01

    Ultrafast Phenomena XVII presents the latest advances in ultrafast science, including both ultrafast optical technology and the study of ultrafast phenomena. It covers picosecond, femtosecond and attosecond processes relevant to applications in physics, chemistry, biology, and engineering. Ultraf...

  6. Micronuclei: sensitivity for the detection of radiation induced damage

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Nasazzi, N.B.; Taja, M.R.

    1998-01-01

    The in vitro cytokinesis-block (CB) micronucleus (MN) assay for human peripheral blood has been used extensively for the assessment of chromosomal damage induced by ionizing radiation and chemicals and considered a suitable biological dosimeter for estimating in vivo whole body exposures, particularly in the case of large scale radiation accidents. One of the major drawbacks of the MN assay is its reduced sensitivity for the detection of damage induced by low doses of low LET radiation, due to the high variability among the spontaneous MN frequencies. It is suggested that age, smoking habit and sex are the main confounding factors that contribute to the observed variability. Previous work in our laboratory, shows a significant positive correlation of the spontaneous and radiation induced MN frequencies with age and smoking habit, the latter being the strongest confounder. These findings led to in vitro studies of the dose-response relationships for smoking and non smoking donors evaluated separately, using 60 Co γ rays. The objectives of the present work are: 1-To increase the amount of data of the dose-response relationships, using γ rays from a 60 Co source, for smoking and non smoking donors, in order to find, if applicable, a correction factor for the calibration curve that takes into account the smoking habit of the individual in the case of accidental overexposure dose assessment, particularly in the low dose range. 2-To establish general conclusions on the current state of the technique. The sample for smoking and non smoking calibration curves was enlarged in the range of 0Gy to 2Gy. The fitting of both curves, performed up to the 2Gy dose, resulted in a linear quadratic model. MN distribution among bi nucleated cells was found to be over dispersed with respect to Poisson distribution, the average ratio of variance to mean being 1.13 for non smokers and 1.17 for smokers. Each fitted calibration curve, for smoking and non smoking donors, fell within the 95

  7. Ultrafast scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  8. Ultrafast Graphene Photonics and Optoelectronics

    Science.gov (United States)

    2017-04-14

    AFRL-AFOSR-JP-TR-2017-0032 Ultrafast Graphene Photonics and Optoelectronics Kuang-Hsiung Wu National Chiao Tung University Final Report 04/14/2017...DATES COVERED (From - To) 18 Apr 2013 to 17 Apr 2016 4. TITLE AND SUBTITLE Ultrafast Graphene Photonics and Optoelectronics 5a.  CONTRACT NUMBER 5b...Prescribed by ANSI Std. Z39.18 Final Report for AOARD Grant FA2386-13-1-4022 “Ultrafast Graphene Photonics and Optoelectronics” Date May 23th, 2016

  9. Screening for early detection of radiation-associated thyroid cancer

    International Nuclear Information System (INIS)

    Ron, E.; Modan, B.; Lubin, E.

    1984-01-01

    In the 1950s, approximately 20,000 Israeli children received scalp irradiation as treatment for tinea capitis (ringworm of the scalp). To evaluate the necessity and feasibility of early screening of these individuals for thyroid cancer, a small pilot program was undertaken. The examination consisted of a thorough palpation of the thyroid gland and the surrounding area. A sup(99m)Tc thyroid scan and thyroid function tests were performed on individuals in whom palpation suggested a nodular abnormality. A multidisciplinary committee then made a recommendation for or against surgery. A total of 443 persons were screened, and nodular abnormalities of the thyroid were detected in 24 (5.4%). Of these persons, nine displayed symptomatology or reported knowledge of a thyroid condition; despite this, three of them were not receiving treatment. This left 18 subjects - 15 new cases and 3 previously untreated patients - needing follow-up care. Altogether nine persons were recommended for surgery, but one refused. All eight of the excised lesions were benign: four colloid nodules and four adenomas. While the screening program was feasible, the fact that no cancers were detected suggested that in a population exposed to a very low dose of radiation, thyroid screening may not be justified on a large scale.

  10. Development of radiation detection and measurement system - Development of scintillation radiation sensor

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hee Dong; Kim, Wan [Kyungpook National University, Taegu (Korea); Kim, Do Sung [Taegu University, Taegu (Korea)

    2000-03-01

    We have been fabricated CsI(Tl) scintillation crystals and plastic scintillators for radiation-based measuring equipment. CsI (Tl) single crystals doped with thallium as an activator were grown using the Czochralski method. The crystal structure of grown CsI(Tl) was bcc, and it was confirmed that its lattice constant was 4,568 A. The spectral range of luminescence of CsI(Tl) was 350 {approx} 700 nm independent of thallium concentration, and the fast component of the luminescence was decreased with increasing thallium concentration. The energy resolution of CsI(Tl) scintillator doped with 0.1 mole% thallium was about 9% for 137 Cs {gamma}-rays. The relation formula of {gamma}-ray energy versus energy resolution was ln(FWHM%)=-0.705ln({epsilon})+6.75. The radiation damage of CsI(Tl) increased in proportion to thallium concentration and radiation damage of CsI(Tl) increased in proportion to thallium concentration and radiation dosage, and the irradiated crystals were colored reddish. The radiation induced absorption bands appeared around 355, 425, 520 and 555 nm, and their energy level were about 3.50, 2.88, 2.39 and 2.21 eV. Plastic scintillators were fabricated thermal polymerization method. Those were polymerizing at 120 deg. C, during 72 hours, and annealing at 75 deg. C, during 24 hours. When the concentration of 1st solute was 1.5 wt% and concentration of 2nd solute was 0.01 wt%, the characteristics of scintillation were very excellent. Also 3.0 wt% tetraphenyl lead were loaded to improve the detection efficiency of {gamma}-ray. The range of emission spectrum was 400 {approx} 450nm, and the central peak was 415 nm. The radiation damage was not appear under 1*10{sup 3}Gy, but the color of plastic scintillator was changed to brown, over 1*10{sup 4}Gy exposured. 84 refs., 39 figs. (Author)

  11. Fourteenth International Conference on Ultrafast Phenomena

    CERN Document Server

    Kobayashi, Takayoshi; Kobayashi, Tetsuro; Nelson, Keith A; Silvestri, Sandro; Ultrafast Phenomena XIV

    2005-01-01

    Ultrafast Phenomena XIV presents the latest advances in ultrafast science, including ultrafast laser and measurement technology as well as studies of ultrafast phenomena. Pico-, femto-, and atosecond processes relevant in physics, chemistry, biology and engineering are presented. Ultrafast technology is now having a profound impact within a wide range of applications, among them imaging, material diagnostics, and transformation and high-speed optoelectronics. This book summarizes results presented at the 14th Ultrafast Phenomena Conference and reviews the state of the art in this important and rapidly advancing field.

  12. Sixteenth International Conference on Ultrafast Phenomena

    CERN Document Server

    Corkum, Paul; Nelson, Keith A; Riedle, Eberhard; Schoenlein, Robert W; Ultrafast Phenomena XVI

    2009-01-01

    Ultrafast Phenomena XVI presents the latest advances in ultrafast science, including both ultrafast optical technology and the study of ultrafast phenomena. It covers picosecond, femtosecond and attosecond processes relevant to applications in physics, chemistry, biology, and engineering. Ultrafast technology has a profound impact in a wide range of applications, amongst them biomedical imaging, chemical dynamics, frequency standards, material processing, and ultrahigh speed communications. This book summarizes the results presented at the 16th International Conference on Ultrafast Phenomena and provides an up-to-date view of this important and rapidly advancing field.

  13. Delay-Line Three-Dimensional Position Sensitive Radiation Detection

    Science.gov (United States)

    Jeong, Manhee

    High-resistivity silicon(Si) in large volumes and with good charge carrier transport properties has been produced and achieved success as a radiation detector material over the past few years due to its relatively low cost as well as the availability of well-established processing technologies. One application of that technology is in the fabrication of various position-sensing topologies from which the incident radiation's direction can be determined. We have succeeded in developing the modeling tools for investigating different position-sensing schemes and used those tools to examine both amplitude-based and time-based methods, an assessment that indicates that fine position-sensing can be achieved with simpler readout designs than are conventionally deployed. This realization can make ubiquitous and inexpensive deployment of special nuclear materials (SNM) detecting technology becomes more feasible because if one can deploy position-sensitive semiconductor detectors with only one or two contacts per side. For this purpose, we have described the delay-line radiation detector and its optimized fabrication. The semiconductor physics were simulated, the results from which guided the fabrication of the guard ring structure and the detector electrode, both of which included metal-field-plates. The measured improvement in the leakage current was confirmed with the fabricated devices, and the structures successfully suppressed soft-breakdown. We also demonstrated that fabricating an asymmetric strip-line structure successfully minimizing the pulse shaping and increases the distance through which one can propagate the information of the deposited charge distribution. With fabricated delay-line detectors we can acquire alpha spectra (Am-241) and gamma spectra (Ba-133, Co-57 and Cd-109). The delay-line detectors can therefore be used to extract the charge information from both ion and gamma-ray interactions. Furthermore, standard charge-sensitive circuits yield high SNR

  14. Nuisance Source Population Modeling for Radiation Detection System Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sokkappa, P; Lange, D; Nelson, K; Wheeler, R

    2009-10-05

    A major challenge facing the prospective deployment of radiation detection systems for homeland security applications is the discrimination of radiological or nuclear 'threat sources' from radioactive, but benign, 'nuisance sources'. Common examples of such nuisance sources include naturally occurring radioactive material (NORM), medical patients who have received radioactive drugs for either diagnostics or treatment, and industrial sources. A sensitive detector that cannot distinguish between 'threat' and 'benign' classes will generate false positives which, if sufficiently frequent, will preclude it from being operationally deployed. In this report, we describe a first-principles physics-based modeling approach that is used to approximate the physical properties and corresponding gamma ray spectral signatures of real nuisance sources. Specific models are proposed for the three nuisance source classes - NORM, medical and industrial. The models can be validated against measured data - that is, energy spectra generated with the model can be compared to actual nuisance source data. We show by example how this is done for NORM and medical sources, using data sets obtained from spectroscopic detector deployments for cargo container screening and urban area traffic screening, respectively. In addition to capturing the range of radioactive signatures of individual nuisance sources, a nuisance source population model must generate sources with a frequency of occurrence consistent with that found in actual movement of goods and people. Measured radiation detection data can indicate these frequencies, but, at present, such data are available only for a very limited set of locations and time periods. In this report, we make more general estimates of frequencies for NORM and medical sources using a range of data sources such as shipping manifests and medical treatment statistics. We also identify potential data sources for industrial

  15. Growth and characterization of single-crystal CVD diamond for radiation detection applications

    International Nuclear Information System (INIS)

    Tranchant, N.

    2008-01-01

    This work aimed at the study of the synthesis of single crystal diamond using the Microwave enhanced Chemical Vapour Deposition technique (MPCVD). The work enabled the development and optimisation of the growth conditions, from the study of the crystalline quality, of the material purity, and of its electronic properties. The assessment of the transport properties was the most determinant: the use of the time of flight (TOF) technique has enabled the measurement of the carrier mobilities and of their kinetic properties as a function of the temperature. When coupled with collected charge efficiency measurements, the work led to remarkable carrier mobility values obtained in the synthesised crystals (3000 cm 2 .V-1.s -1 ). Prepared samples were mounted as detection devices and used successfully in real conditions for the monitoring of ultra-fast pulses, as well as for neutron fluency monitoring, and for medical dosimeters for radiotherapy applications. (author)

  16. The All Terrain Bio nano Gear for Space Radiation Detection System

    International Nuclear Information System (INIS)

    Ummat, Ajay; Mavroidis, Constantinos

    2007-01-01

    This paper discusses about the relevance of detecting space radiations which are very harmful and pose numerous health issues for astronauts. There are many ways to detect radiations, but we present a non-invasive way of detecting them in real-time while an astronaut is in the mission. All Terrain Bio-nano (ATB) gear system is one such concept where we propose to detect various levels of space radiations depending on their intensity and warn the astronaut of probable biological damage. A basic framework for radiation detection system which utilizes bio-nano machines is discussed. This radiation detection system is termed as 'radiation-responsive molecular assembly' (RMA) for the detection of space radiations. Our objective is to create a device which could detect space radiations by creating an environment equivalent to human cells within its structure and bio-chemically sensing the effects induced therein. For creating such an environment and further bio-chemically sensing space radiations bio-nano systems could be potentially used. These bio-nano systems could interact with radiations and signal based on the intensity of the radiations their relative biological effectiveness. Based on the energy and kind of radiation encountered, a matrix of signals has to be created which corresponds to a particular biological effect. The key advantage of such a design is its ability to interact with the radiation at e molecular scale; characterize its intensity based on energy deposition and relate it to the relative biological effectiveness based on the correspondence established through molecular structures and bond strengths of the bio-nano system

  17. Detection and measurement of ionizing radiation by the Radioactive Waste Management Centre

    International Nuclear Information System (INIS)

    Mudra, Josef

    2013-01-01

    The following topics are dealt with: Basic properties of radionuclides and selection of suitable detectors; radiation characteristics of sealed sources (radiation detection, dose rate measurement, surface contamination measurement, gamma spectroscopy); non-destructive analysis (segment gamma scanner, digital radiography); destructive analysis; radiation monitoring of humans and workplaces; and dosimetric monitoring of workplace surroundings and discharges. (orig.)

  18. Radiation Detection System for Prevention of Illicit Trafficking of Nuclear and Radioactive Materials

    International Nuclear Information System (INIS)

    Kwak, Sung Woo; Chang, Sung Soon; Yoo, Ho Sik

    2010-01-01

    Fixed radiation portal monitors (RPMs) deployed at border, seaport, airport and key traffic checkpoints have played an important role in preventing the illicit trafficking and transport of nuclear and radioactive materials. However, the RPM is usually large and heavy and can't easily be moved to different locations. These reasons motivate us to develop a mobile radiation detection system. The objective of this paper is to report our experience on developing the mobile radiation detection system for search and detection of nuclear and radioactive materials during road transport. Field tests to characterize the developed detection system were performed at various speeds and distances between the radioactive isotope (RI) transporting car and the measurement car. Results of measurements and detection limits of our system are described in this paper. The mobile radiation detection system developed should contribute to defending public's health and safety and the environment against nuclear and radiological terrorism by detecting nuclear or radioactive material hidden illegally in a vehicle

  19. Development of thin dosemeters of CaSO4: Dy for beta radiation detection

    International Nuclear Information System (INIS)

    Campos, L.L.

    1987-01-01

    Thin pellets of CaSO: Dy (0,20mm) were produced and tested in beta radiation fields. The Thermolumiscent (TL) characteristics studied were sensitivity, reproducibility, lower detection limit, linearity of TL response with absorved dose energy dependence. The results show the usefulness of this thin pellets in beta radiation detection. (Author) [pt

  20. High Density Nano-Electrode Array for Radiation Detection

    International Nuclear Information System (INIS)

    Misra, Mano

    2010-01-01

    Bulk single crystals of Cd 1-x Zn x Te (x=0.04 to x=0.2) compound semiconductor is used for room temperature radiation detection. The production of large volume of Cd 1-x Zn x Te with low defect density is expensive. As a result there is a growing research interest in the production of nanostructured compound semiconductors such as Cd 1-x Zn x Te in an electrochemical route. In this investigation, Cd 1-x Zn x Te ternary compound semiconductor, referred as CZT, was electrodeposited in the form of nanowires onto a TiO 2 nanotubular template from propylene carbonate as the non-aqueous electrolyte, using a pulse-reverse electrodeposition process at 130 C. The template acted as a support in growing ordered nanowire of CZT which acts as a one dimensional conductor. Cyclic Voltammogram (CV) studies were conducted in determining the potentials for the growth of nanowires of uniform stoichiometry. The morphologies and composition of CZT were characterized by using SEM, TEM and XRD. The STEM mapping carried out on the nanowires showed the uniform distribution of Cd, Zn and Te elements. TEM image showed that the nanowires were polycrystalline in nature. The Mott-Schottky analysis carried on the nanowires showed that the nanowires were a p-type semiconductor. The carrier density, band gap and resistivity of the Cd 0.9 Zn 0.1 Te nanowires were 4.29 x 10 13 cm -3 , 1.56 eV and 2.76 x 10 11 (Omega)-cm respectively. The high resistivity was attributed to the presence of deep defect states such as cadmium vacancies or Te antisites which were created by the anodic cycle of the pulse-reverse electrodeposition process. Stacks of series connected CZT nanowire arrays were tested with different bias potentials. The background current was in the order of tens of picoamperes. When exposed to radiation source Amerecium-241 (60 KeV, 4 (micro)Ci), the stacked CZT nanowires arrays showed sensing behavior. The sensitivity of the nanowire arrays increased as the number of stacks increased. The

  1. High Density Nano-Electrode Array for Radiation Detection

    Energy Technology Data Exchange (ETDEWEB)

    Mano Misra

    2010-05-07

    Bulk single crystals of Cd1-xZnxTe (x=0.04 to x=0.2) compound semiconductor is used for room temperature radiation detection. The production of large volume of Cd1-xZnxTe with low defect density is expensive. As a result there is a growing research interest in the production of nanostructured compound semiconductors such as Cd1-xZnxTe in an electrochemical route. In this investigation, Cd1-xZnxTe ternary compound semiconductor, referred as CZT, was electrodeposited in the form of nanowires onto a TiO2 nanotubular template from propylene carbonate as the non-aqueous electrolyte, using a pulse-reverse electrodeposition process at 130 ºC. The template acted as a support in growing ordered nanowire of CZT which acts as a one dimensional conductor. Cyclic Voltammogram (CV) studies were conducted in determining the potentials for the growth of nanowires of uniform stoichiometry. The morphologies and composition of CZT were characterized by using SEM, TEM and XRD. The STEM mapping carried out on the nanowires showed the uniform distribution of Cd, Zn and Te elements. TEM image showed that the nanowires were polycrystalline in nature. The Mott-Schottky analysis carried on the nanowires showed that the nanowires were a p-type semiconductor. The carrier density, band gap and resistivity of the Cd0.9Zn0.1Te nanowires were 4.29x1013 cm-3, 1.56 eV and 2.76x1011Ω-cm respectively. The high resistivity was attributed to the presence of deep defect states such as cadmium vacancies or Te antisites which were created by the anodic cycle of the pulse-reverse electrodeposition process. Stacks of series connected CZT nanowire arrays were tested with different bias potentials. The background current was in the order of tens of picoamperes. When exposed to radiation source Amerecium-241 (60 KeV, 4 μCi), the stacked CZT nanowires arrays showed sensing behavior. The sensitivity of the nanowire arrays increased as the number of stacks increased. The preliminary results indicate that the

  2. Rain-Induced Increase in Background Radiation Detected by Radiation Portal Monitors

    Energy Technology Data Exchange (ETDEWEB)

    Hausladen, Paul [ORNL; Blessinger, Christopher S [ORNL; Guzzardo, Tyler [ORNL; Livesay, Jake [ORNL

    2012-07-01

    A complete understanding of both the steady state and transient background measured by Radiation Portal Monitors (RPMs) is essential to predictable system performance, as well as maximization of detection sensitivity. To facilitate this understanding, a test bed for the study of natural background in RPMs has been established at the Oak Ridge National Laboratory. This work was performed in support of the Second Line of Defense Program's mission to detect the illicit movement of nuclear material. In the present work, transient increases in gamma ray counting rates in RPMs due to rain are investigated. The increase in background activity associated with rain, which has been well documented in the field of environmental radioactivity, originates from the atmospheric deposition of two radioactive daughters of radon-222, namely lead-214 and bismuth-214 (henceforth {sup 222}Rn, {sup 214}Pb and {sup 214}Bi). In this study, rainfall rates recorded by a co-located weather station are compared with RPM count rates and High Purity Germanium spectra. The data verifies these radionuclides are responsible for the dominant transient natural background fluctuations in RPMs. Effects on system performance and potential mitigation strategies are discussed.

  3. Stochastic Radiative Transfer Model for Contaminated Rough Surfaces: A Framework for Detection System Design

    Science.gov (United States)

    2013-11-01

    example for the detection of a potassium chlorate contaminated “car” with a CO2 tunable laser system. 15. SUBJECT TERMS Radiative transfer...detector m-out-of-n detector Potassium chlorate Probability theory System performance Probability of detection and false alarm iii...for the detection of a potassium chlorate contaminated “car” with a CO2 tunable laser system. Subject Terms Radiative transfer, contaminated

  4. Radiation and detectors introduction to the physics of radiation and detection devices

    CERN Document Server

    Cerrito, Lucio

    2017-01-01

    This textbook provides an introduction to radiation, the principles of interaction between radiation and matter, and the exploitation of those principles in the design of modern radiation detectors. Both radiation and detectors are given equal attention and their interplay is carefully laid out with few assumptions made about the prior knowledge of the student. Part I is dedicated to radiation, broadly interpreted in terms of energy and type, starting with an overview of particles and forces, an extended review of common natural and man-made sources of radiation, and an introduction to particle accelerators. Particular attention is paid to real life examples, which place the types of radiation and their energy in context. Dosimetry is presented from a modern, user-led point of view, and relativistic kinematics is introduced to give the basic knowledge needed to handle the more formal aspects of radiation dynamics and interaction. The explanation of the physics principles of interaction between radiation an...

  5. Detection device of dangerous radiation for the living beings

    International Nuclear Information System (INIS)

    Lacoste, F.

    1991-01-01

    This invention is about a portable device able to measure dose rates or doses of gamma, ultraviolet and X radiation or charged particles. This device is composed of a radiation detector, a calculator of the accumulate dose and a memory to store the data. This device has a credit card format

  6. Radiation Protection in the Application of Active Detection Technologies

    Science.gov (United States)

    2013-07-01

    BECKER, S.M. (2004). “Emergency communication and information issues in terrorism events involving radioactive materials,” Biosecur Bioterror. 2(3...National Council on Radiation Protection and Measurements. Considerations Regarding the Unintended Radiation Exposure of the Embryo, Fetus or Nursing

  7. On advisability of developing automatic complexes of radiation flow detection

    International Nuclear Information System (INIS)

    Akopov, V.S.; Voronin, S.A.; Meshalkin, I.A.

    1976-01-01

    On the basis of mathematical treatment of statistical data obtained by inquest of specialists from a number of factories, problems associated with the determination of the most acceptable efficiency of radiation defectoscopy automatized complexes are considered. Production requirements for radiation control sensitivity are generalized. The use of providing the complexes with computer technique is substantiated

  8. Proposal of secure camera-based radiation warning system for nuclear detection

    International Nuclear Information System (INIS)

    Tsuchiya, Ken'ichi; Kurosawa, Kenji; Akiba, Norimitsu; Kakuda, Hidetoshi; Imoto, Daisuke; Hirabayashi, Manato; Kuroki, Kenro

    2016-01-01

    Counter-terrorisms against radiological and nuclear threat are significant issues toward Tokyo 2020 Olympic and Paralympic Games. In terms of cost benefit, it is not easy to build a warning system for nuclear detection to prevent a Dirty Bomb attack (dispersion of radioactive materials using a conventional explosive) or a Silent Source attack (hidden radioactive materials) from occurring. We propose a nuclear detection system using the installed secure cameras. We describe a method to estimate radiation dose from noise pattern in CCD images caused by radiation. Some dosimeters under neutron and gamma-ray irradiations (0.1mSv-100mSv) were taken in CCD video camera. We confirmed amount of noise in CCD images increased in radiation exposure. The radiation detection using CMOS in secure cameras or cell phones has been implemented. However, in this presentation, we propose a warning system including neutron detection to search shielded nuclear materials or radiation exposure devices using criticality. (author)

  9. Application of organic semiconductors for the detection of ionizing radiations

    International Nuclear Information System (INIS)

    Kozelj, M.; Cvikl, B.; Korosak, D.

    2006-01-01

    One year aged organic bilayer Al/PCTDA/CuPc/ITO structure prepared with ICB deposition method has been used to evaluate the influence of ionising radiation to electrical properties of the structure. Small sources of α, β and γ radiation were used for preliminary measurements. Capacitance and current measurements were performed on samples with and without presence of ionising radiation and results compared. Effect of β and γ radiation has not been confirmed due to the limited activity of available sources. Presence of α radiation has noticeably changed the capacitance of reversely biased structure and produced increase of current through the structure. We have tried to explain the capacitance properties using the model previously developed for the organic bilayer structures, but we did not manage to resolve all effects involved. (author)

  10. Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

    International Nuclear Information System (INIS)

    Bero, M A; Abukassem, I

    2009-01-01

    Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

  11. Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

    Science.gov (United States)

    Bero, M. A.; Abukassem, I.

    2009-05-01

    Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

  12. Human Portable Radiation Detection System Communications Package Evaluation

    International Nuclear Information System (INIS)

    Morgen, Gerald P.; Peterson, William W.

    2009-01-01

    Testing and valuation of the Human Portable Radiation Detection System Communications Package for the US Coast Guard. The main components of the HCP field kit are an Archer Field PC(reg s ign) and an Iridium satellite phone, along with various charging components and cables. The Archer Field PC has an Enfora Global System for Mobile/General Packet Radio System (GSM/GPRS) wireless cellular modem installed via the compact flash (CF) port. The Iridium satellite phone has a serial communication interface attached. The Archer Field PC is running Windows Mobile(reg s ign) 5.0 operating system. Included Microsoft products are Excel(reg s ign) Mobile, PowerPoint(reg s ign) Mobile, Word(reg s ign) Mobile, and Internet Explorer(reg s ign) Mobile. There is an Outlook(reg s ign) Email program that can be accessed via sending a file or the Messaging link. The Cambridge Computer Corporation vxHpc program is installed to provide a Hyperterm-like software product. vxHpc supports multiple communication protocols. An AT and T SIM card was provided for the GSM wireless cellular modem. A check with AT and T determined the SIM card was not activated to provide cellular service. The Iridium satellite phone did not have a SIM card and has no service. The Archer Field PC boots into a HCP program, displaying the Main Menu. The following actions can be executed by selecting the appropriate box: Spectrum Download, Spectrum Transfer, and Admin Control. The Spectrum Download function uses the serial communication port to download data files from another device, such as a Radiation Isotope Identification Device (RIID). The Spectrum Transfer function uses either the installed wireless cellular modem or the Iridium satellite phone (attached to the serial communication port) to send data files to a computer modem at the Laboratories and Scientific Services (LSS). The Admin Control function allows entering phone numbers and data file deletion. PNNL recommends that DNDO (and/or CG) contact Sanmina

  13. Alpha radiation detection using silicon memory chips - preliminary studies

    International Nuclear Information System (INIS)

    Pace, R.; Paix, D.; Haskard, M.

    1993-01-01

    Alpha radiation dosage is an important occupational health factor in the mining of uranium and mineral sands. Alpha radiation induced errors in the data of silicon based memory chips provide the foundation for a new type of sensor, with the potential for affordable and prompt measurement of personal alpha doses. With particular reference to Dynamic Random Access Memories (DRAM) this paper introduces the operating principle of a memory based radiation sensor, which is the error mechanism in silicon integrated circuits. 14 refs., 3 figs

  14. Development of Sensor Technology and Its Application for Nuclear Radiation Detection

    International Nuclear Information System (INIS)

    Hiskia

    2007-01-01

    Radiation is energy in the form of waves or moving subatomic particles. Radiation can be ionizing or nonionizing radiation, depending on its effect on atomic matter. Because radiation cannot be seen, felt, tasted, heard or smelled, even at lethal levels, radiations detection devices must be used to alert those exposed to radiation. The measurement of radioactivity in the environment is a regulatory requirement around sites where significant amounts of radioactive materials are used or stored. Recently, advent in microelectronics and material technology has enabled to produce small sensor or microsensor, sensitive, accurate, and integrated in a chip or substrate. Development of radiation sensor technology using thin/thick film and micromachining technique was described in this paper. Indonesian capabilities in radiation sensor research and development and opportunities for commercialization also given. (author)

  15. The Development of Sensor Technology and Application to Detect Nuclear Radiation

    International Nuclear Information System (INIS)

    Hiskia

    2007-01-01

    Radiation is energy in the form of waves or moving subatomic particles. Radiation can be ionizing or non-ionizing radiation, depending on its effect on atomic matter. Because radiation cannot be seen, felt, tasted, heard or smelled, even at lethal levels, radiations detection devices must be used to alert those exposed to radiation. The measurement of radioactivity in the environment is a regulatory requirement around sites where significant amounts of radioactive materials are used or stored. Recently, advent in microelectronics and material technology has enabled to produce small sensor or microsensor, sensitive, accurate, and integrated in a chip or substrate. Development of radiation sensor technology using thin/thick film and micromachining technique was described in this paper. Indonesian capabilities in radiation sensor research and development and opportunities for commercialization also given. (author)

  16. Shining light on radiation detection and energy transfer : Triazole ligands used for detection of radiation and lanthanide binding

    NARCIS (Netherlands)

    Dijkstra, Peter

    2016-01-01

    Some substances, fluorophores, absorb light and then emit that light again as fluorescence. Apart from absorption of light, some of these substances can also emit light after having absorbed energy from radiation. A substance which can absorb radiation and emit the energy as light is called a

  17. Einstein as Armchair Detective: The Case of Stimulated Radiation

    Indian Academy of Sciences (India)

    theory and of gravity in the case of the general theory. It might be argued that the ... the radiation density p at different frequencies through. Planck's law. He assumes .... derive both Planck's law and Bohr's principle based on these hypotheses.

  18. Development of radiation hardened pixel sensors for charged particle detection

    CERN Document Server

    Koziel, Michal

    2014-01-01

    CMOS Pixel Sensors are being developed since a few years to equip vertex detectors for future high-energy physics experiments with the crucial advantages of a low material budget and low production costs. The features simultaneously required are a short readout time, high granularity and high tolerance to radiation. This thesis mainly focuses on the radiation tolerance studies. To achieve the targeted readout time (tens of microseconds), the sensor pixel readout was organized in parallel columns restricting in addition the readout to pixels that had collected the signal charge. The pixels became then more complex, and consequently more sensitive to radiation. Different in-pixel architectures were studied and it was concluded that the tolerance to ionizing radiation was limited to 300 krad with the 0.35- m fabrication process currently used, while the targeted value was several Mrad. Improving this situation calls for implementation of the sensors in processes with a smaller feature size which naturally imp...

  19. Ionizing radiation detection meter systems usability evaluation. Technical memorandum

    International Nuclear Information System (INIS)

    Severs, Y.; Hughes, R.; Tack, D.; Bossi, L.L.M.

    2002-12-01

    In support of the Canadian Forces Nuclear Detection, Identification and Dosimetry project a usability trial of three Ionizing Radiation Detection Meter Systems (IRDMS) was conducted 18-22 June 2001 at Connaught Ranges. The systems evaluated: System 1: ANPDR 77 Operational System with PDR 77 Alpha/Beta probes and GPS (Global Positioning System) Training System; System 2: ADM 300C Operational System with ABP 100 Alpha/Beta probes and GPS Training System, and System 3: RAM R200 Operational System with PA 100M and RG12 Alpha/Beta probes and GPS Training System. Twelve military personnel (Private to Captain) determined compliance with the bid evaluation criteria. The counter-balanced study, based on a Latin square design, was divided into two assessment phases, an operational phase and a training system phase, which rotated three groups (of four participants each) concurrently through each IRDMS. Groups were trained in set-up, maintenance and operation of each bid IRDMS prior to evaluation. The operational evaluation consisted of a test/maintenance stand, an indoor/outdoor operational stand, and an indoor,/outdoor training system stand. Participants rated the utility and usability of each system, by measuring case of use/maintenance under a range of relevant operational and clothing conditions, compatibility with soldier tasks, compatibility with clothing, compatibility with equipment and operational environments, and case of learning (including an assessment of initial and refresher training implications). A 7-point Likert-like acceptability rating scale, which covered a range from completely unacceptable (1) to completely acceptable (7), was used to evaluate the measures. The combined weighted mean scores were 584.3 for System 1 (70 o /b), 682.0 for System 2 (81 %) and 756.9 for System 3 (90%) out of a total possible score of 840. Participants reported mean scores for System 1 between barely unacceptable and borderline for both indoor and outdoor operations. System 2

  20. A Method for Improving Reliability of Radiation Detection using Deep Learning Framework

    International Nuclear Information System (INIS)

    Chang, Hojong; Kim, Tae-Ho; Han, Byunghun; Kim, Hyunduk; Kim, Ki-duk

    2017-01-01

    Radiation detection is essential technology for overall field of radiation and nuclear engineering. Previously, technology for radiation detection composes of preparation of the table of the input spectrum to output spectrum in advance, which requires simulation of numerous predicted output spectrum with simulation using parameters modeling the spectrum. In this paper, we propose new technique to improve the performance of radiation detector. The software in the radiation detector has been stagnant for a while with possible intrinsic error of simulation. In the proposed method, to predict the input source using output spectrum measured by radiation detector is performed using deep neural network. With highly complex model, we expect that the complex pattern between data and the label can be captured well. Furthermore, the radiation detector should be calibrated regularly and beforehand. We propose a method to calibrate radiation detector using GAN. We hope that the power of deep learning may also reach to radiation detectors and make huge improvement on the field. Using improved radiation detector, the reliability of detection would be confident, and there are many tasks remaining to solve using deep learning in nuclear engineering society.

  1. 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.)

  2. Laser-driven ultrafast antiproton beam

    Science.gov (United States)

    Li, Shun; Pei, Zhikun; Shen, Baifei; Xu, Jiancai; Zhang, Lingang; Zhang, Xiaomei; Xu, Tongjun; Yu, Yong; Bu, Zhigang

    2018-02-01

    Antiproton beam generation is investigated based on the ultra-intense femtosecond laser pulse by using two-dimensional particle-in-cell and Geant4 simulations. A high-flux proton beam with an energy of tens of GeV is generated in sequential radiation pressure and bubble regime and then shoots into a high-Z target for producing antiprotons. Both yield and energy of the antiproton beam increase almost linearly with the laser intensity. The generated antiproton beam has a short pulse duration of about 5 ps and its flux reaches 2 × 10 20 s - 1 at the laser intensity of 2.14 × 10 23 W / cm 2 . Compared to conventional methods, this new method based on the ultra-intense laser pulse is able to provide a compact, tunable, and ultrafast antiproton source, which is potentially useful for quark-gluon plasma study, all-optical antihydrogen generation, and so on.

  3. Ultrafast photoconductor detector-laser-diode transmitter

    International Nuclear Information System (INIS)

    Wang, C.L.; Davis, B.A.; Davies, T.J.; Nelson, M.A.; Thomas, M.C.; Zagarino, P.A.

    1987-01-01

    We report the results of an experiment in which we used an ultrafast, photoconductive, radiation detector to drive a fast laser-diode transmitter. When we irradiated the neutron-damaged Cr-doped GaAs detector with 17-MeV electron beams, the temporal response was measured to be less than 30 ps. The pulses from this detector modulated a fast GaAlAs laser diode to transmit the laser output through 30- and 1100-m optical fibers. Preliminary results indicate that 50- and 80-ps time resolutions, respectively, are obtainable with these fibers. We are now working to integrate the photoconductive detector and the laser diode transmitter into a single chip

  4. Ultrafast photoconductive detector-laser-diode transmitter

    International Nuclear Information System (INIS)

    Wang, C.L.; Davies, T.J.; Nelson, M.A.; Thomas, M.C.; Zagarino, P.A.; Davis, B.A.

    1987-01-01

    The authors report the results of an experiment in which they used an ultrafast, photoconductive, radiation detector to drive a fast laser-diode transmitter. When they irradiated the neutron-damaged Cr-doped Ga/As detector with 17-MeV electron beams, the temporal response of was measured to be less than 30 ps. The pulses from this detector modulated a fast GaAlAs laser diode to transmit the laser output through 30- and 1100-m optical fibers. Preliminary results indicate that 50- and 80-ps time resolutions, respectively, are obtainable with these fibers. They are now working to integrate the photoconductive detector and the laser diode transmitter into a single chip

  5. Ultra-fast ipsilateral DPOAE adaptation not modulated by attention?

    Science.gov (United States)

    Dalhoff, Ernst; Zelle, Dennis; Gummer, Anthony W.

    2018-05-01

    Efferent stimulation of outer hair cells is supposed to attenuate cochlear amplification of sound waves and is accompanied by reduced DPOAE amplitudes. Recently, a method using two subsequent f2 pulses during presentation of a longer f1 pulse was introduced to measure fast ipsilateral adaptation effects on separated DPOAE components. Compensating primary-tone onsets for their latencies at the f2-tonotopic place, the average adaptation measured in four normal-hearing subjects was 5.0 dB with a time constant below 5 ms. In the present study, two experiments were performed to determine the origin of this ultra-fast ipsilateral adaptation effect. The first experiment measured ultra-fast ipsilateral adaptation using a two-pulse paradigm at three frequencies in the four subjects, while controlling for visual attention of the subjects. The other experiment also controlled for visual attention, but utilized a sequence of f2 short pulses in the presence of a continuous f1 tone to sample ipsilateral adaptation effects with longer time constants in eight subjects. In the first experiment, no significant change in the ultra-fast adaptation between non-directed attention and visual attention could be detected. In contrast, the second experiment revealed significant changes in the magnitude of the slower ipsilateral adaptation in the visual-attention condition. In conclusion, the lack of an attentional influence indicates that the ultra-fast ipsilateral DPOAE adaptation is not solely mediated by the medial olivocochlear reflex.

  6. Hand-held, mechanically cooled, radiation detection system for gamma-ray spectroscopy

    Science.gov (United States)

    Burks, Morgan Thomas; Eckels, Joel Del

    2010-06-08

    In one embodiment, a radiation detection system is provided including a radiation detector and a first enclosure encapsulating the radiation detector, the first enclosure including a low-emissivity infra-red (IR) reflective coating used to thermally isolate the radiation detector. Additionally, a second enclosure encapsulating the first enclosure is included, the first enclosure being suspension mounted to the second enclosure. Further, a cooler capable of cooling the radiation detector is included. Still yet, a first cooling interface positioned on the second enclosure is included for coupling the cooler and the first enclosure. Furthermore, a second cooling interface positioned on the second enclosure and capable of coupling the first enclosure to a cooler separate from the radiation detection system is included. Other embodiments are also presented.

  7. Non-Destructive Detection and Separation of Radiation Damaged Cells in Miniaturized, Inexpensive Device, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a clear and well-identified need for rapid, efficient, non-destructive detection and isolation of radiation damaged cells. Available commercial technologies...

  8. Ultrafast vibrations of gold nanorings

    DEFF Research Database (Denmark)

    Kelf, T; Tanaka, Y; Matsuda, O

    2011-01-01

    We investigate the vibrational modes of gold nanorings on a silica substrate with an ultrafast optical technique. By comparison with numerical simulations, we identify several resonances in the gigahertz range associated with axially symmetric deformations of the nanoring and substrate. We...

  9. Ultrafast spectroscopy of biological photoreceptors

    NARCIS (Netherlands)

    Kennis, J.T.M.; Groot, M.L.

    2007-01-01

    We review recent new insights on reaction dynamics of photoreceptors proteins gained from ultrafast spectroscopy. In Blue Light sensing Using FAD (BLUF) domains, a hydrogen-bond rearrangement around the flavin chromophore proceeds through a radical-pair mechanism, by which light-induced electron and

  10. Ultrafast Spectroscopy of Semiconductor Devices

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang; Hvam, Jørn Marcher

    1999-01-01

    In this work we present an experimental technique for investigating ultrafast carrier dynamics in semiconductor optical amplifiers at room temperature. These dynamics, influenced by carrier heating, spectral hole-burning and two-photon absorption, are very important for device applications in inf...

  11. Ultrafast vibrations of gold nanorings

    DEFF Research Database (Denmark)

    Kelf, T; Tanaka, Y; Matsuda, O

    2011-01-01

    We investigate the vibrational modes of gold nanorings on a silica substrate with an ultrafast optical technique. By comparison with numerical simulations, we identify several resonances in the gigahertz range associated with axially symmetric deformations of the nanoring and substrate. We elucid...

  12. An investigation of medical radiation detection using CMOS image sensors in smartphones

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Han Gyu [Department of Senior Healthcare, Graduate School of Eulji University, Daejeon 301-746 (Korea, Republic of); Song, Jae-Jun [Department of Otorhinolaryngology-Head & Neck Surgery, Korea University, Guro Hospital,148, Gurodong-ro, Guro-gu, Seoul 152-703 (Korea, Republic of); Lee, Kwonhee [Graduate Program in Bio-medical Science, Korea University, 2511 Sejong-ro, Sejong City 339-770 (Korea, Republic of); Nam, Ki Chang [Department of Medical Engineering, College of Medicine, Dongguk University, 32 Dongguk-ro, Goyang-si, Gyeonggi-do 410-820 (Korea, Republic of); Hong, Seong Jong; Kim, Ho Chul [Department of Radiological Science, Eulji University, 553 Yangji-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do 431-713 (Korea, Republic of)

    2016-07-01

    Medical radiation exposure to patients has increased with the development of diagnostic X-ray devices and multi-channel computed tomography (CT). Despite the fact that the low-dose CT technique can significantly reduce medical radiation exposure to patients, the increasing number of CT examinations has increased the total medical radiation exposure to patients. Therefore, medical radiation exposure to patients should be monitored to prevent cancers caused by diagnostic radiation. However, without using thermoluminescence or glass dosimeters, it is hardly measure doses received by patients during medical examinations accurately. Hence, it is necessary to develop radiation monitoring devices and algorithms that are reasonably priced and have superior radiation detection efficiencies. The aim of this study is to investigate the feasibility of medical dose measurement using complementary metal oxide semiconductor (CMOS) sensors in smartphone cameras with an algorithm to extract the X-ray interacted pixels. We characterized the responses of the CMOS sensors in a smartphone with respect to the X-rays generated by a general diagnostic X-ray system. The characteristics of the CMOS sensors in a smartphone camera, such as dose response linearity, dose rate dependence, energy dependence, angular dependence, and minimum detectable activity were evaluated. The high energy gamma-ray of 662 keV from Cs-137 can be detected using the smartphone camera. The smartphone cameras which employ the developed algorithm can detect medical radiations.

  13. An investigation of medical radiation detection using CMOS image sensors in smartphones

    International Nuclear Information System (INIS)

    Kang, Han Gyu; Song, Jae-Jun; Lee, Kwonhee; Nam, Ki Chang; Hong, Seong Jong; Kim, Ho Chul

    2016-01-01

    Medical radiation exposure to patients has increased with the development of diagnostic X-ray devices and multi-channel computed tomography (CT). Despite the fact that the low-dose CT technique can significantly reduce medical radiation exposure to patients, the increasing number of CT examinations has increased the total medical radiation exposure to patients. Therefore, medical radiation exposure to patients should be monitored to prevent cancers caused by diagnostic radiation. However, without using thermoluminescence or glass dosimeters, it is hardly measure doses received by patients during medical examinations accurately. Hence, it is necessary to develop radiation monitoring devices and algorithms that are reasonably priced and have superior radiation detection efficiencies. The aim of this study is to investigate the feasibility of medical dose measurement using complementary metal oxide semiconductor (CMOS) sensors in smartphone cameras with an algorithm to extract the X-ray interacted pixels. We characterized the responses of the CMOS sensors in a smartphone with respect to the X-rays generated by a general diagnostic X-ray system. The characteristics of the CMOS sensors in a smartphone camera, such as dose response linearity, dose rate dependence, energy dependence, angular dependence, and minimum detectable activity were evaluated. The high energy gamma-ray of 662 keV from Cs-137 can be detected using the smartphone camera. The smartphone cameras which employ the developed algorithm can detect medical radiations.

  14. Highly sensitive detection of ionizing radiations by a photoluminescent uranyl organic framework

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Jian; Wang, Yaxing; Liu, Wei; Yin, Xuemiao; Chen, Lanhua; Diwu, Juan; Chai, Zhifang; Wang, Shuao [School for Radiological and interdisciplinary Sciences (RAD-X) and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou (China); Zou, Youming [High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui (China); Albrecht-Schmitt, Thomas E. [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL (United States); Liu, Guokui [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL (United States)

    2017-06-19

    Precise detection of low-dose X- and γ-radiations remains a challenge and is particularly important for studying biological effects under low-dose ionizing radiation, safety control in medical radiation treatment, survey of environmental radiation background, and monitoring cosmic radiations. We report here a photoluminescent uranium organic framework, whose photoluminescence intensity can be accurately correlated with the exposure dose of X- or γ-radiations. This allows for precise and instant detection of ionizing radiations down to the level of 10{sup -4} Gy, representing a significant improvement on the detection limit of approximately two orders of magnitude, compared to other chemical dosimeters reported up to now. The electron paramagnetic resonance analysis suggests that with the exposure to radiations, the carbonyl double bonds break affording oxo-radicals that can be stabilized within the conjugated uranium oxalate-carboxylate sheet. This gives rise to a substantially enhanced equatorial bonding of the uranyl(VI) ions as elucidated by the single-crystal structure of the γ-ray irradiated material, and subsequently leads to a very effective photoluminescence quenching through phonon-assisted relaxation. The quenched sample can be easily recovered by heating, enabling recycled detection for multiple runs. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Track structure theory in radiobiology and in radiation detection

    International Nuclear Information System (INIS)

    Katz, R.

    1978-01-01

    The response of biological cells, and many physical radiation and track detectors to ionizing radiations and to energetic heavily ionizing particles, results from the secondary and higher generation electrons ejected from the atoms and molecules of the detector by the incident primary radiation. The theory uses a calculation of the radial distribution of local dose deposited by secondary electrons (delta-rays) from an energetic heavy ion as a transfer function, relating the dose-response relation measured (or postulated) for a particular detector in a uniform radiation field (gamma-rays) to obtain the radial distribution in response about the ion's path, and thus the structure of the track of a particle. Subsequent calculations yield the response of the detector to radiation fields of arbitrary quality. The models which have been used for detector response arise from target theory, and are of the form of statistical models called multi-hit or multi-target detectors, in which it is assumed that there are sensitive elements (emulsion grains, or biological cell nuclei) which may require many hits (emulsion grains) or single hits in different targets (say, cellular chromosomes) in order to produce the observed end-point. Recent work has demonstrated that many-hit physical detectors do exist. From both emulsion sensitometry and from the structure of tracks of heavy ions, it can be shown that emulsion-developer combinations exist which yield many-hit response. There is also some evidence that the supralinearity in thermoluminescent dosimeters arises from a mixture of 1-hit and 2-hit response, perhaps of different trap structures within the same TLD crystal. These detectors can be expected to mimic the response of biological cells to radiations of different quality. Their patterns of response may help us to understand better the structure of particle tracks in SSNTD's. (author)

  16. Application of CVD diamond film for radiation detection

    International Nuclear Information System (INIS)

    Zhou Haiyang; Zhu Xiaodong; Zhan Rujuan

    2005-01-01

    With the development of diamond synthesis at low pressure, the CVD diamond properties including electronic characteristics have improved continuously. Now the fabrication of electronic devices based on the CVD diamond has been one of hot research subjects in this field. Due to many unique advantages, such as high signal-noise ratio, fast time response, and normal output in extremely harsh surrounding, the CVD diamond radiation detector has attracted more and more interest. In this paper, we have reviewed the development and status of the CVD diamond radiation detector. The prospect of this detector is described. (authors)

  17. Detection of nuclear radiations; Deteccion de Radiaciones nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Tanarro Sanz, A

    1967-07-01

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

  18. Detection of nuclear radiations; Detectores de radiaciones nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Tanarro Sanz, A

    1959-07-01

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

  19. Thermoluminescence analysis for detection of irradiated food - luminescence characteristics of minerals for different types of radiation and radiation doses

    International Nuclear Information System (INIS)

    Soika, C.; Delincée, H.

    2000-01-01

    Federal Research Centre for Nutrition, Institute of Nutritional Physiology, Haid-und-Neu-Straße 9, 76131 Karlsruhe (Germany) Thermoluminescence analysis is used to detect radiation processing of foods which are contaminated with sand or dust. Silicate minerals are isolated, their radiation-induced luminescence is measured and compared to the thermoluminescence from a second measurement after exposure to a dexned radiation dose (normalization). In the present study, the mineral mixture *sand+ and its main components feldspar and quartz were investigated for their thermoluminescence behaviour using different types of radiation, in order to determine adequate radiation sources for the purpose of normalization. The material was irradiated with types of ionizing radiation commonly used for commercial food irradiation, i.e. accelerated electrons with beam energies of 5 MeV as well as 10 MeV, and 60 Co--rays. After thermoluminescence measurements, samples were re-irradiated using either accelerated electrons with beam energies of 2 MeV, 5 MeV or 10 MeV, or 60 Co--rays, 90 Sr--rays or ultraviolet rays (200}280 nm). Evaluation of the xrst and corresponding second glow curve revealed that their shapes depend on the type of minerals in the mixture. The second radiation treatment (normalization) is satisfactory when accelerated electrons (2, 5 and 10 MeV) as well as 60 Co--rays and 90 Sr--rays are employed. Normalization with ultraviolet rays, however, has only a limited range of use

  20. Nanotechnology-Based Systems for Nuclear Radiation and Chemical Detection

    International Nuclear Information System (INIS)

    Kody Varahramyan; Pedro Derosa; Chester Wilson

    2006-01-01

    This main objectives of this effort are the development and prototyping of a small, sensitive, and low-cost multi-channel nanoparticle scintillation microdevice with integrated waveguides for alpha, beta, gamma, and neutron detection. This research effort has integrated experiments and simulation to determine the combination of process-specific materials for the achievement optimum detection conditions

  1. Standoff alpha radiation detection for hot cell imaging and crime scene investigation

    Science.gov (United States)

    Kerst, Thomas; Sand, Johan; Ihantola, Sakari; Peräjärvi, Kari; Nicholl, Adrian; Hrnecek, Erich; Toivonen, Harri; Toivonen, Juha

    2018-02-01

    This paper presents the remote detection of alpha contamination in a nuclear facility. Alpha-active material in a shielded nuclear radiation containment chamber has been localized by optical means. Furthermore, sources of radiation danger have been identified in a staged crime scene setting. For this purpose, an electron-multiplying charge-coupled device camera was used to capture photons generated by alpha-induced air scintillation (radioluminescence). The detected radioluminescence was superimposed with a regular photograph to reveal the origin of the light and thereby the alpha radioactive material. The experimental results show that standoff detection of alpha contamination is a viable tool in radiation threat detection. Furthermore, the radioluminescence spectrum in the air is spectrally analyzed. Possibilities of camera-based alpha threat detection under various background lighting conditions are discussed.

  2. CaSO4: Dy + Teflon dosimetric pellets for X, beta and gamma radiation detection

    International Nuclear Information System (INIS)

    Campos, L.L.; Lima, M.F.

    1987-08-01

    CaSO 4 : Dy + TEFLON dosimetric pellets with high sensitivity and low cost for X, beta and gamma radiation monitoring were studied and developed by the Dosimetric Material Production Laboratory of the Radiological Protection Departament and are disposable for sale. The thickness of the pellets are suitable for X, beta and gamma radiation measurements. The dosimetric properties of these pellets were determined and presented in this work. The results show the usefulness of 0,20mm thick pellets for beta radiation monitoring and 0,80mm thick pellets for x and gamma radiation detection. (Author) [pt

  3. Apparatus for detecting alpha radiation in difficult access areas

    International Nuclear Information System (INIS)

    Steadman, P.; MacArthur, D.W.

    1997-01-01

    An electrostatic alpha radiation detector for measuring alpha radiation emitted from inside an enclosure comprising an electrically conductive expandable electrode for insertion into the enclosure is disclosed. After insertion, the electrically conductive expandable electrode is insulated from the enclosure and defines a decay cavity between the electrically conductive expandable electrode and the enclosure so that air ions generated in the decay cavity are electrostatically captured by the electrically conductive expandable electrode and the enclosure when an electric potential is applied between the electrically conductive expandable electrode and the enclosure. Indicator means are attached to the electrically conductive expandable electrode for indicating an electrical current produced by generation of the air ions generated in the decay cavity by collisions between air molecules and the alpha particles emitted from the enclosure. A voltage source is connected between the indicator means and the electrically conductive enclosure for creating an electric field between the electrically conductive expandable electrode and the enclosure. 4 figs

  4. 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

  5. InP based semioconductor structures for radiation detection

    Czech Academy of Sciences Publication Activity Database

    Procházková, Olga; Grym, Jan; Pekárek, Ladislav; Zavadil, Jiří; Žďánský, Karel

    2008-01-01

    Roč. 19, 8/9 (2008), s. 700-775 ISSN 0957-4522. [Semiconducting & Insulating Materials Conference - SIMC /14./. Fayetteville, 15.05.2007-20.05.2007] R&D Projects: GA ČR GA102/06/0153 Institutional research plan: CEZ:AV0Z20670512 Keywords : semiconductor technology * rare earth compounds * radiation detectors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.054, year: 2008

  6. Track structure theory in radiobiology and in radiation detection

    International Nuclear Information System (INIS)

    Katz, R.

    1976-01-01

    The response of biological cells, and many physical radiation and track detectors to ionizing radiations, and to energetic heavily ionizing particles results from the secondary and higher generation electrons ejected from the atoms and molecules of the detector by the incident primary radiation. The models which have been used for detector response arise from target theory, and are of the form of statistical models called multi-hit or multi-target detectors, in which it is assumed that there are sensitive elements (emulsion grains, or biological cell nuclei) which may require many hits (emulsion grains) or single hits in different targets (say, cellular chromosomes) in order to produce the observed endpoint. Physically, a hit is interpreted as a 'registered event' caused by an electron passing through the sensitive site, with an efficiency which depends on the electron's speed. Some knowledge of size of the sensitive volume and of the sensitive target is required to make the transition from gamma-ray response to heavy ion response. Recent work has demonstrated that many-hit physical detectors do exist. From both emulsion sensitometry and from the structure of tracks of heavy ions, we are able to show that emulsion-developer combinations exist which yield many-hit response. There is also some evidence that the supralinearity in thermoluminescent dosimeters arises from a trap structures within the same TLD crystal. These detectors can be expected to mimic the response of biological cells to radiations of different quality. Their patterns of response may help us to understand better the structure of particle tracks in SSNTD's. (orig./ORU) [de

  7. UTILIZATION OF PHOSWICH DETECTORS FOR SIMULTANEOUS, MULTIPLE RADIATION DETECTION

    International Nuclear Information System (INIS)

    Miller, William H.; Manuel Diaz de Leon

    2003-01-01

    A phoswich radiation detector is comprised of a phosphor sandwich in which several different phosphors are viewed by a common photomultiplier. By selecting the appropriate phosphors, this system can be used to simultaneously measure multiple radiation types (alpha, beta, gamma and/or neutron) with a single detector. Differentiation between the signals from the different phosphors is accomplished using digital pulse shape discrimination techniques. This method has been shown to result in accurate discrimination with highly reliable and versatile digital systems. This system also requires minimal component count (i.e. only the detector and a computer for signal processing). A variety of detectors of this type have been built and tested including: (1) a triple phoswich system for alpha/beta/gamma swipe counting, (2) two well-type detectors for measuring low levels of low energy photons in the presence of a high energy background, (3) a large area detector for measuring beta contamination in the presence of a photon background, (4) another large area detector for measuring low energy photons from radioactive elements such as uranium in the presence of a photon background. An annular geometry, triple phoswich system optimized for measuring alpha/beta/gamma radiation in liquid waste processing streams is currently being designed

  8. UTILIZATION OF PHOSWICH DETECTORS FOR SIMULTANEOUS, MULTIPLE RADIATION DETECTION

    Energy Technology Data Exchange (ETDEWEB)

    William H. Miller; Manuel Diaz de Leon

    2003-04-15

    A phoswich radiation detector is comprised of a phosphor sandwich in which several different phosphors are viewed by a common photomultiplier. By selecting the appropriate phosphors, this system can be used to simultaneously measure multiple radiation types (alpha, beta, gamma and/or neutron) with a single detector. Differentiation between the signals from the different phosphors is accomplished using digital pulse shape discrimination techniques. This method has been shown to result in accurate discrimination with highly reliable and versatile digital systems. This system also requires minimal component count (i.e. only the detector and a computer for signal processing). A variety of detectors of this type have been built and tested including: (1) a triple phoswich system for alpha/beta/gamma swipe counting, (2) two well-type detectors for measuring low levels of low energy photons in the presence of a high energy background, (3) a large area detector for measuring beta contamination in the presence of a photon background, (4) another large area detector for measuring low energy photons from radioactive elements such as uranium in the presence of a photon background. An annular geometry, triple phoswich system optimized for measuring alpha/beta/gamma radiation in liquid waste processing streams is currently being designed.

  9. System and method for extracting physiological information from remotely detected electromagnetic radiation

    NARCIS (Netherlands)

    2016-01-01

    The present invention relates to a device and a method for extracting physiological information indicative of at least one health symptom from remotely detected electromagnetic radiation. The device comprises an interface (20) for receiving a data stream comprising remotely detected image data

  10. System and method for extracting physiological information from remotely detected electromagnetic radiation

    NARCIS (Netherlands)

    2015-01-01

    The present invention relates to a device and a method for extracting physiological information indicative of at least one health symptom from remotely detected electromagnetic radiation. The device comprises an interface (20) for receiving a data stream comprising remotely detected image data

  11. AN IMAGE-ANALYSIS TECHNIQUE FOR DETECTION OF RADIATION-INDUCED DNA FRAGMENTATION AFTER CHEF ELECTROPHORESIS

    NARCIS (Netherlands)

    ROSEMANN, M; KANON, B; KONINGS, AWT; KAMPINGA, HH

    CHEF-electrophoresis was used as a technique to detect radiation-induced DNA breakage with special emphasis to biological relevant X-ray doses (0-10 Gy). Fluorescence detection of DNA-fragments using a sensitive image analysis system was directly compared with conventional scintillation counting of

  12. On the γ-photon detection processes and the statistics of radiation

    International Nuclear Information System (INIS)

    Bertolotti, M.; Sibilia, C.

    1977-01-01

    The problem of detection of γ-photons is treated in the cases of photoelectric and Compton effects. In both cases the probability of detecting a γ-photon is found proportional to the first-order correlation function of the e.m. field. The statistical properties of the γ-radiation can therefore be determined through the methods developed in quantum optics

  13. Ultrafast 2-dimensional image monitoring and array-based passive cavitation detection for ultrasound contrast agent destruction in a variably sized region.

    Science.gov (United States)

    Xu, Shanshan; Hu, Hong; Jiang, Hujie; Xu, Zhi'an; Wan, Mingxi

    2014-11-01

    A combined approach was proposed, based on programmable ultrasound equipment, to simultaneously monitor surviving microbubbles and detect cavitation activity during microbubble destruction in a variably sized region for use in ultrasound contrast agent (UCA)-enhanced therapeutic ultrasound applications. A variably sized focal region wherein the acoustic pressure was above the UCA fragmentation threshold was synthesized at frequencies of 3, 4, 5, and 6 MHz with a linear broadband imaging probe. The UCAs' temporal and spatial distribution during the microbubbles' destruction was monitored in a 2-dimensional imaging plane at 5 MHz and a frame rate of 400 Hz, and simultaneously, broadband noise emissions during the microbubbles' fragmentation were extracted by using the backscattered signals produced by the focused release bursts (ie, destruction pulses) themselves. Afterward, the temporal evolution of broadband noise emission, the surviving microbubbles in a region of interest (ROI), and the destruction area in a static UCA suspension were computed. Then the inertial cavitation dose, destruction rate of microbubbles in the ROI, and area of the destruction region were determined. It was found that an increasing pulse length and a decreasing transmit aperture and excitation frequency were correlated with an increased inertial cavitation dose, microbubble destruction rate, and destruction area. Furthermore, it was obvious that the microbubble destruction rate was significantly correlated with the inertial cavitation dose (P cavitation dose could be regulated by manipulating the transmission parameters. © 2014 by the American Institute of Ultrasound in Medicine.

  14. Simulation and modeling for the stand-off radiation detection system (SORDS) using GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, Andrew S [Los Alamos National Laboratory; Wallace, Mark [Los Alamos National Laboratory; Galassi, Mark [Los Alamos National Laboratory; Mocko, Michal [Los Alamos National Laboratory; Palmer, David [Los Alamos National Laboratory; Schultz, Larry [Los Alamos National Laboratory; Tornga, Shawn [Los Alamos National Laboratory

    2009-01-01

    A Stand-Off Radiation Detection System (SORDS) is being developed through a joint effort by Raytheon, Los Alamos National Laboratory, Bubble Technology Industries, Radiation Monitoring Devices, and the Massachusetts Institute of Technology, for the Domestic Nuclear Detection Office (DNDO). The system is a mobile truck-based platform performing detection, imaging, and spectroscopic identification of gamma-ray sources. A Tri-Modal Imaging (TMI) approach combines active-mask coded aperture imaging, Compton imaging, and shadow imaging techniques. Monte Carlo simulation and modeling using the GEANT4 toolkit was used to generate realistic data for the development of imaging algorithms and associated software code.

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

    International Nuclear Information System (INIS)

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

    1993-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-03-01

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

  17. Direct detection of darkmatter in radiative seesaw model

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Daniel; Schwetz, Thomas [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Toma, Takashi [Institute for Theoretical Physics, Kanazawa University (Japan)

    2012-07-01

    In the radiative seesaw model proposed by Ma, we assume that the lightest right-handed neutrino is the Dark Matter candidate and almost degenerated with the second lightest right-handed neutrino. Thus, elastic Dark Matter-nucleus scattering is suppressed. Inelastic scattering is induced by a lepton-loop coupled to the photon. Effectively, there are charge-charge, dipole-charge and dipole-dipole interactions. We present the event rate of the model and compare it with existing data. Moreover, monochromatic photons from the decay of the excited Dark Matter state are discussed.

  18. Ultrafast Thermal Transport at Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Cahill, David [Univ. of Illinois, Champaign, IL (United States); Murphy, Catherine [Univ. of Illinois, Champaign, IL (United States); Martin, Lane [Univ. of Illinois, Champaign, IL (United States)

    2014-10-21

    Our research program on Ultrafast Thermal Transport at Interfaces advanced understanding of the mesoscale science of heat conduction. At the length and time scales of atoms and atomic motions, energy is transported by interactions between single-particle and collective excitations. At macroscopic scales, entropy, temperature, and heat are the governing concepts. Key gaps in fundamental knowledge appear at the transitions between these two regimes. The transport of thermal energy at interfaces plays a pivotal role in these scientific issues. Measurements of heat transport with ultrafast time resolution are needed because picoseconds are the fundamental scales where the lack of equilibrium between various thermal excitations becomes a important factor in the transport physics. A critical aspect of our work has been the development of experimental methods and model systems that enabled more precise and sensitive investigations of nanoscale thermal transport.

  19. Development of mobile radiation detection system against nuclear terrorism in Korea

    International Nuclear Information System (INIS)

    Kwak, Sung-Woo; Chang, Sung-Soon; Yoo, Ho-Sik

    2011-01-01

    A fixed radiation portal monitors (RPM) deployed at border, seaport, airport or key traffic checkpoints has played an important role in preventing the illicit trafficking and transport of nuclear and radioactive materials. However, the RPM usually is large and heavy and can't easily be moved to a different location. An intelligent terrorist may also circumvent the fixed RPM to avoid being detected. These reasons motivate us to develop a mobile radiation detection system. The objective of this paper is to report our experience on developing the mobile radiation detection system for the search and detection of nuclear and radioactive materials during road transport. Measurements were performed at various speeds and distances between the radioactive isotope (RI) transporting car and the measurement car. Results of our measurements and the detection limits of the system is described in this paper. The mobile radiation detection system developed should contribute to defending public's health and safety and the environment against nuclear and radiological terrorism by detecting nuclear or radioactive material hidden illegally in a vehicle. (author)

  20. Large single-crystal diamond substrates for ionizing radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Girolami, Marco; Bellucci, Alessandro; Calvani, Paolo; Trucchi, Daniele M. [Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Sede Secondaria di Montelibretti, Monterotondo Stazione, Roma (Italy)

    2016-10-15

    The need for large active volume detectors for ionizing radiations and particles, with both large area and thickness, is becoming more and more compelling in a wide range of applications, spanning from X-ray dosimetry to neutron spectroscopy. Recently, 8.0 x 8.0 mm{sup 2} wide and 1.2 mm thick single-crystal diamond plates have been put on the market, representing a first step to the fabrication of large area monolithic diamond detectors with optimized charge transport properties, obtainable up to now only with smaller samples. The more-than-double thickness, if compared to standard plates (typically 500 μm thick), demonstrated to be effective in improving the detector response to highly penetrating ionizing radiations, such as γ-rays. Here we report on the first measurements performed on large active volume single-crystal diamond plates, both in the dark and under irradiation with optical wavelengths (190-1100 nm), X-rays, and radioactive γ-emitting sources ({sup 57}Co and {sup 22}Na). (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Design of autotrack detecting instrument for solar UV radiation

    Science.gov (United States)

    Xia, Jiangtao; Mao, Xiaoli; Zhao, Jing

    2009-11-01

    In order to autotrack the object and detect the solar UV index, a reliable real-time high-precise instrument is proposed in this paper. This instrument involves two subsystems: the autotrack and detecting modules. The autotrack module consists of four-quadrant photo detector, multi-channel signal processing circuit and precise stepping system. The detecting module designed for dada measurement and acquisition is made up of the ultraviolet sensor UV460 and high precision A/D converter MAX1162. The key component of the entire instrument is ultralow-power microprocessor MSP430 which is used for entire system controlling and data processing. The lower system of autotracking and measurement is communicated with upper PC computer by RS232 module. In the experiment, the tracking precision of two-dimensional motion revolving stage is calibrated to be less than 0.05°. Experimental results indicate that the system designed could realize the precise autotracking and detecting function well, and the measure precision of system has reached the desirable target.

  2. Detection of radiation-induced apoptosis using the comet assay

    International Nuclear Information System (INIS)

    Wada, Seiichi; Kobayashi, Yasuhiko; Funayama, Tomoo; Yamamoto, Kazuo; Khoa, Tran Van; Natsuhori, Masahiro; Ito, Nobuhiko

    2003-01-01

    The electrophoresis pattern of apoptotic cells detected by the comet assay has a characteristic small head and spread tail. This image has been referred to as an apoptotic comet, but it has not been previously proven to be apoptotic cells by any direct method. In order to identify this image obtained by the comet assay as corresponding to an apoptotic cell, the frequency of appearance of apoptosis was examined using CHO-K1 and L5178Y cells which were exposed to gamma irradiation. As a method for detecting apoptosis, the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay was used. When the frequency of appearance of apoptotic cells following gamma irradiation was observed over a period of time, there was a significant increase in appearance of apoptosis when using the TUNEL assay. However, there was only a slight increase when using the comet assay. In order to verify the low frequency of appearance of apoptosis when using the comet assay, we attempted to use the TUNEL assay to satin the apoptotic comets detected in the comet assay. The apoptotic comets were TUNEL positive and the normal comets were TUNEL negative. This indicates that the apoptotic comets were formed from DNA fragments with 3'-hydroxy ends that are generated as cells undergo apoptosis. Therefore, it was understood that the characteristic pattern of apoptotic comets detected by the comet assay corresponds to cells undergoing apoptosis. (author)

  3. Analysis of Scattered Radiation Influence on Detectability in Diagnostic Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Gurvich, V [ALVIM R and D Ltd., P.O.B. 801 Jerusalem 91007 (Israel); Manevich, I [Jerusalem College of Technology, 21 Havaad Haleumi St. P.O.B. 16031, Jerusalem 91160 (Israel)

    1994-12-31

    The calculation of holes detectability in tissue equivalent materials on a X-ray image is implemented. In the calculation various values of scatter accumulation factor are used. The obtained results confirmed by experimental data may be useful for choice of physics-technical conditions of X-ray examination. (authors). 7 refs, 1 fig, 1 tab.

  4. Ultrafast comparison of personal genomes

    OpenAIRE

    Mauldin, Denise; Hood, Leroy; Robinson, Max; Glusman, Gustavo

    2017-01-01

    We present an ultra-fast method for comparing personal genomes. We transform the standard genome representation (lists of variants relative to a reference) into 'genome fingerprints' that can be readily compared across sequencing technologies and reference versions. Because of their reduced size, computation on the genome fingerprints is fast and requires little memory. This enables scaling up a variety of important genome analyses, including quantifying relatedness, recognizing duplicative s...

  5. An integrated circuit/microsystem/nano-enhanced four species radiation sensor for inexpensive fissionable material detection

    Science.gov (United States)

    Waguespack, Randy Paul

    2011-12-01

    Small scale radiation detectors sensitive to alpha, beta, electromagnetic, neutron radiation are needed to combat the threat of nuclear terrorism and maintain national security. There are many types of radiation detectors on the market, and the type of detector chosen is usually determined by the type of particle to be detected. In the case of fissionable material, an ideal detector needs to detect all four types of radiation, which is not the focus of many detectors. For fissionable materials, the two main types of radiation that must be detected are gamma rays and neutrons. Our detector uses a glass or quartz scintillator doped with 10B nanoparticles to detect all four types of radiation particles. Boron-10 has a thermal neutron cross section of 3,840 barns. The interaction between the neutron and boron results in a secondary charge particle in the form of an alpha particle to be emitted, which is detectable by the scintillator. Radiation impinging on the scintillator matrix produces varying optical pulses dependent on the energy of the particles. The optical pulses are then detected by a photomultiplier (PM) tube, creating a current proportional to the energy of the particle. Current pulses from the PM tube are differentiated by on-chip pulse height spectroscopy, allowing for source discrimination. The pulse height circuitry has been fabricated with discrete circuits and designed into an integrated circuit package. The ability to replace traditional PM tubes with a smaller, less expensive photomultiplier will further reduce the size of the device and enhance the cost effectiveness and portability of the detector.

  6. Simulating and Detecting Radiation-Induced Errors for Onboard Machine Learning

    Science.gov (United States)

    Wagstaff, Kiri L.; Bornstein, Benjamin; Granat, Robert; Tang, Benyang; Turmon, Michael

    2009-01-01

    Spacecraft processors and memory are subjected to high radiation doses and therefore employ radiation-hardened components. However, these components are orders of magnitude more expensive than typical desktop components, and they lag years behind in terms of speed and size. We have integrated algorithm-based fault tolerance (ABFT) methods into onboard data analysis algorithms to detect radiation-induced errors, which ultimately may permit the use of spacecraft memory that need not be fully hardened, reducing cost and increasing capability at the same time. We have also developed a lightweight software radiation simulator, BITFLIPS, that permits evaluation of error detection strategies in a controlled fashion, including the specification of the radiation rate and selective exposure of individual data structures. Using BITFLIPS, we evaluated our error detection methods when using a support vector machine to analyze data collected by the Mars Odyssey spacecraft. We found ABFT error detection for matrix multiplication is very successful, while error detection for Gaussian kernel computation still has room for improvement.

  7. Development of Remote Control Laboratory for Radiation Detection via Internet

    International Nuclear Information System (INIS)

    Park, Sang Tae; Lee, Hee Bok; Yuk, Keun Chul

    2002-01-01

    The role of experiments in science education is essential for understanding the natural phenomena and principle related to a subject. Therefore, the remote control experiment via Internet is one of key solution for distance learners in science education. The remote experiments are also necessary for the time-consuming experiment which takes several days, collaborative experiment between distance learners, expensive laboratory equipment which is not usually available to students, experimental procedure which is dangerous, etc. In this study, we have developed a general method for a remote control laboratory system using internet and interface techniques. It is possible for students to learn the nuclear physics to control the real instruments and conduct physics experimentation with internet techniques. We proposed the remote control radiation measurement system as a sample application. This system could be useful for the monitoring near a nuclear power plants in order to improve the environment data credibility to the public

  8. Calibration of ratemeters used for gamma radiation detection

    International Nuclear Information System (INIS)

    Hantanirina, P.A.

    2017-01-01

    The Secondary Standard Dosimetry Laboratory (SSDL) of INSTN-Madagascar is in charge of the calibration of every dosimetry measurement instrument in hospitals and companies using radioactive sources in Madagascar. It has a secondary standard delivered and calibrated by a Primary Standard Laboratory in Dosimetry (PSLD). This standard is used to compare its reference values with those displayed on the instruments to be calibrated. During our training period, three (3) ratemeters were calibrated, the Graetz X5DE, the Graetz X5C and the Identifinder 2. We have determined the calibration factor for every ratemeter by doing calculation with the reference value. By using the three surveymeters for direct radiations measurements, it has been found that the difference between the displayed values and the real values for every ratemeter does not exceed the tolerance limit which is 20 %. Then we can conclude that these ratemeters are still in good condition of functioning. Concerning the calibration factor curve N_k with the K_a_i_r , we can observe that for the Graetz X5C ratemeter, this curve is almost constant. As well as for the linearity, it is still the Graetz X5C ratemeter which is linear almost integrally for the measured and calculated dose rate values. So we can say that this ratemeter is the most recommended for the radiations measurements.This work which has been carried within the framework of collaboration between the section PNAE (Physique Nucléaire Appliquée et Environnement) of the University of Antananarivo and INSTN-Madagascar has been a good and rewarding experience which allowed us to put into practice all knowledges acquired during our years of studies. [fr

  9. GaN heterostructures for biosensing and radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Howgate, John D.

    2012-12-11

    In this thesis I show the results from our investigation of the interface between gallium nitride wide bandgap semiconductor heterostructures and (bio)molecular systems on their surfaces for biosensing, bioelectronics, and photoelectric applications, with a large emphasis on the processes arising from high energy ionizing irradiation, including heterostructure photoelectric gain mechanisms. Wide bandgap semiconductors, such as gallium nitride, have received increasing attention as potential components in advanced organic/inorganic hybrid systems. Working to further this topic, we determine a new semiconductor alignment required for low energy photo-induced charge transfer ionization of alkyl chains well below the energy normally required for molecular cleavage, show original results of the influence of binding methods on enzyme functionality in conjunction with a novel electrochemical and environmental control system and demonstrate new possibilities to significantly improve upon pH measurements through the use of high sensitivity devices. Furthermore, based on the extension of this work to support future studies of radiation effects on cell systems, we present a detailed characterization of new simultaneous chemical sensing and ionizing radiation dosimetry using single devices. We found that their pH sensitivity was retained during X-ray irradiation and that the fundamental characteristics can be used to separate the irradiation signal from the pH response without compromising operational stability. These data provide clear indications of the separate response mechanism tied to the presence of a two-dimensional electron gas channel. Here, we found new results exhibiting exceptionally high gains and independence of the well-known persistent photoconductivity for soft X-rays and high energy particles in the ultralow dose-rate regime. This material system provides the capability for high sensitivity and resolution real time monitoring, which is competitive with and

  10. GaN heterostructures for biosensing and radiation detection

    International Nuclear Information System (INIS)

    Howgate, John D.

    2012-01-01

    In this thesis I show the results from our investigation of the interface between gallium nitride wide bandgap semiconductor heterostructures and (bio)molecular systems on their surfaces for biosensing, bioelectronics, and photoelectric applications, with a large emphasis on the processes arising from high energy ionizing irradiation, including heterostructure photoelectric gain mechanisms. Wide bandgap semiconductors, such as gallium nitride, have received increasing attention as potential components in advanced organic/inorganic hybrid systems. Working to further this topic, we determine a new semiconductor alignment required for low energy photo-induced charge transfer ionization of alkyl chains well below the energy normally required for molecular cleavage, show original results of the influence of binding methods on enzyme functionality in conjunction with a novel electrochemical and environmental control system and demonstrate new possibilities to significantly improve upon pH measurements through the use of high sensitivity devices. Furthermore, based on the extension of this work to support future studies of radiation effects on cell systems, we present a detailed characterization of new simultaneous chemical sensing and ionizing radiation dosimetry using single devices. We found that their pH sensitivity was retained during X-ray irradiation and that the fundamental characteristics can be used to separate the irradiation signal from the pH response without compromising operational stability. These data provide clear indications of the separate response mechanism tied to the presence of a two-dimensional electron gas channel. Here, we found new results exhibiting exceptionally high gains and independence of the well-known persistent photoconductivity for soft X-rays and high energy particles in the ultralow dose-rate regime. This material system provides the capability for high sensitivity and resolution real time monitoring, which is competitive with and

  11. Enhancing international radiation/nuclear detection training opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Thomas L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bersell, Bridget M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Booker, Paul M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, Gerald E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leitch, Rosalyn M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Meagher, John B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Siefken, Rob R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Spracklen, James L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-23

    The United States has worked domestically to develop and provide radiological and nuclear detection training and education initiatives aimed at interior law enforcement, but the international community has predominantly focused efforts at border and customs officials. The interior law enforcement officials of a State play a critical role in maintaining an effective national-level nuclear detection architecture. To meet this vital need, DNDO was funded by the U.S. Department of State (DOS) to create and deliver a 1-week course at the International Law Enforcement Academy (ILEA) in Budapest, Hungary to inform interior law enforcement personnel of the overall mission, and to provide an understanding of how the participants can combat the threats of radiological and nuclear terrorism through detection efforts. Two courses, with approximately 20 students in each course, were delivered in fiscal year (FY) 2013, two were delivered in FY 2014 and FY 2015, and as of this report’s writing more are planned in FY 2016. However, while the ILEA courses produced measurable success, DNDO requested Pacific Northwest National Laboratory (PNNL) research potential avenues to further increase the course impact.In a multi-phased approach, PNNL researched and analyzed several possible global training locations and venues, and other possible ways to increase the impact of the course using an agreed-to data-gathering format.

  12. Ultrafast quantum control of ionization dynamics in krypton.

    Science.gov (United States)

    Hütten, Konrad; Mittermair, Michael; Stock, Sebastian O; Beerwerth, Randolf; Shirvanyan, Vahe; Riemensberger, Johann; Duensing, Andreas; Heider, Rupert; Wagner, Martin S; Guggenmos, Alexander; Fritzsche, Stephan; Kabachnik, Nikolay M; Kienberger, Reinhard; Bernhardt, Birgitta

    2018-02-19

    Ultrafast spectroscopy with attosecond resolution has enabled the real time observation of ultrafast electron dynamics in atoms, molecules and solids. These experiments employ attosecond pulses or pulse trains and explore dynamical processes in a pump-probe scheme that is selectively sensitive to electronic state of matter via photoelectron or XUV absorption spectroscopy or that includes changes of the ionic state detected via photo-ion mass spectrometry. Here, we demonstrate how the implementation of combined photo-ion and absorption spectroscopy with attosecond resolution enables tracking the complex multidimensional excitation and decay cascade of an Auger auto-ionization process of a few femtoseconds in highly excited krypton. In tandem with theory, our study reveals the role of intermediate electronic states in the formation of multiply charged ions. Amplitude tuning of a dressing laser field addresses different groups of decay channels and allows exerting temporal and quantitative control over the ionization dynamics in rare gas atoms.

  13. Ultrafast optical ranging using microresonator soliton frequency combs

    Science.gov (United States)

    Trocha, P.; Karpov, M.; Ganin, D.; Pfeiffer, M. H. P.; Kordts, A.; Wolf, S.; Krockenberger, J.; Marin-Palomo, P.; Weimann, C.; Randel, S.; Freude, W.; Kippenberg, T. J.; Koos, C.

    2018-02-01

    Light detection and ranging is widely used in science and industry. Over the past decade, optical frequency combs were shown to offer advantages in optical ranging, enabling fast distance acquisition with high accuracy. Driven by emerging high-volume applications such as industrial sensing, drone navigation, or autonomous driving, there is now a growing demand for compact ranging systems. Here, we show that soliton Kerr comb generation in integrated silicon nitride microresonators provides a route to high-performance chip-scale ranging systems. We demonstrate dual-comb distance measurements with Allan deviations down to 12 nanometers at averaging times of 13 microseconds along with ultrafast ranging at acquisition rates of 100 megahertz, allowing for in-flight sampling of gun projectiles moving at 150 meters per second. Combining integrated soliton-comb ranging systems with chip-scale nanophotonic phased arrays could enable compact ultrafast ranging systems for emerging mass applications.

  14. Detection of the strange bodies on the conveyor belt using gamma radiation technique

    International Nuclear Information System (INIS)

    Barna, A.; Ochiana, G.; Oncescu, M.

    1990-01-01

    The aim of this paper is to present a method for the computation of the activity of a gamma radiation source used in a radiometric assembly designed to detect the strange bodies (iron, stone or wood-made granules) within the textile material on the conveyor belt. The mathematical modelling method based on the Monte Carlo procedure has been used, with different values of the errors of types I and II; the investigation method is the transmission of gamma radiations. (Author)

  15. Detection of gamma-neutron radiation by solid-state scintillation detectors. Detection of gamma-neutron radiation by novel solid-state scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhikov, V.; Grinyov, B.; Piven, L.; Onyshchenko, G.; Sidletskiy, O. [Institute for Scintillation Materials of the NAS of Ukraine, Kharkov, (Ukraine); Naydenov, S. [Institute for Single Crystals of the National Academy of Sciences of Ukraine, Kharkov, (Ukraine); Pochet, T. [DETEC-Europe, Vannes (France); Smith, C. [Naval Postgraduate School, Monterey, CA (United States)

    2015-07-01

    It is known that solid-state scintillators can be used for detection of both gamma radiation and neutron flux. In the past, neutron detection efficiencies of such solid-state scintillators did not exceed 5-7%. At the same time it is known that the detection efficiency of the gamma-neutron radiation characteristic of nuclear fissionable materials is by an order of magnitude higher than the efficiency of detection of neutron fluxes alone. Thus, an important objective is the creation of detection systems that are both highly efficient in gamma-neutron detection and also capable of exhibiting high gamma suppression for use in the role of detection of neutron radiation. In this work, we present the results of our experimental and theoretical studies on the detection efficiency of fast neutrons from a {sup 239}Pu-Be source by the heavy oxide scintillators BGO, GSO, CWO and ZWO, as well as ZnSe(Te, O). The most probable mechanism of fast neutron interaction with nuclei of heavy oxide scintillators is the inelastic scattering (n, n'γ) reaction. In our work, fast neutron detection efficiencies were determined by the method of internal counting of gamma-quanta that emerge in the scintillator from (n, n''γ) reactions on scintillator nuclei with the resulting gamma energies of ∼20-300 keV. The measured efficiency of neutron detection for the scintillation crystals we considered was ∼40-50 %. The present work included a detailed analysis of detection efficiency as a function of detector and area of the working surface, as well as a search for new ways to create larger-sized detectors of lower cost. As a result of our studies, we have found an unusual dependence of fast neutron detection efficiency upon thickness of the oxide scintillators. An explanation for this anomaly may involve the competition of two factors that accompany inelastic scattering on the heavy atomic nuclei. The transformation of the energy spectrum of neutrons involved in the (n, n

  16. Ultrafast and ultrasensitive dielectric liquids/mixtures: Basic measurements and applications

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Faidas, H.; McCorkle, D.L.; Tennessee Univ., Knoxville, TN

    1989-01-01

    Basic properties of cryogenic and room temperature dielectric liquids/mixtures with high electron yields (under irradiation by ionizing particles) and high excess electron drift velocities are discussed. A number of ultrafast and ultrasensitive liquid media -- appropriate for possible use in liquid-filled radiation detectors and other applications -- are identified. 44 refs., 12 figs

  17. 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.

  18. Using Thermal Radiation in Detection of Negative Obstacles

    Science.gov (United States)

    Rankin, Arturo L.; Matthies, Larry H.

    2009-01-01

    A method of automated detection of negative obstacles (potholes, ditches, and the like) ahead of ground vehicles at night involves processing of imagery from thermal-infrared cameras aimed at the terrain ahead of the vehicles. The method is being developed as part of an overall obstacle-avoidance scheme for autonomous and semi-autonomous offroad robotic vehicles. The method could also be applied to help human drivers of cars and trucks avoid negative obstacles -- a development that may entail only modest additional cost inasmuch as some commercially available passenger cars are already equipped with infrared cameras as aids for nighttime operation.

  19. Detection limits by EPR spectroscopy of cumulated doses ionizing radiations in molluscs shells

    International Nuclear Information System (INIS)

    Ostrowski, K.; Burlinska, G.; Dziedzic-Goclawska, A.; Stachowicz, W.; Michalik, J.; Sadlo, J.

    1997-01-01

    The exposure of waters to ionizing radiation from radionuclides stored in concrete containers or freed in nuclear accidents or underwater eruption might be difficult to be proved, when currents, rains, exchange of water displace sand soils or rocks in the bottom. Ionizing radiation evokes stable paramagnetic centers in the crystalline lattice of mineral components in bones as well as in exoskeletons of most molluscs, which are detected by the EPR spectroscopy and could be used as an indicator of the exposure to the action of radiation during prolonged period of time. (authors)

  20. Ultrafast Hierarchical OTDM/WDM Network

    Directory of Open Access Journals (Sweden)

    Hideyuki Sotobayashi

    2003-12-01

    Full Text Available Ultrafast hierarchical OTDM/WDM network is proposed for the future core-network. We review its enabling technologies: C- and L-wavelength-band generation, OTDM-WDM mutual multiplexing format conversions, and ultrafast OTDM wavelengthband conversions.

  1. Avant-Garde Ultrafast Laser Writing

    Directory of Open Access Journals (Sweden)

    Kazansky P. G.

    2013-11-01

    Full Text Available Ultrafast laser processing of transparent materials reveals new phenomena. Reviewed, are recent demonstrations of 5D optical memory, vortex polarization and Airy beam converters employing self-assembled nanostructuring, ultrafast laser calligraphy and polarization writing control using pulses with tilted front.

  2. Power supply connection for ionizing radiation detection probes

    International Nuclear Information System (INIS)

    Zajic, J.

    1990-01-01

    One wire of the supply line is connected, through a diode in the forward direction, to the input terminal of the voltage stabilizer, and through the first resistor to the current limiter terminal of the voltage stabilizer, and also directly to the pulse separator terminal. The current limiter terminal of the voltage stabilizer is connected, through the second resistor, to the output terminal of the voltage stabilizer, and through the first capacitor to the voltage stabilizer earthing terminal, the earthing terminal of the pulse separator and through the other wire of the supply line to the earthing terminal of the detection probe. Furthermore, the input terminal of the voltage stabilizer is connected to a parallel combination of the third resistor with the second capacitor, whose other end is connected to the earthing terminal of the voltage stabilizer. The main asset of this connection consists in the high-frequency matching of the supply line being accomplished by a suitable choice of the resistor value without affecting the voltage for the detection probe. (M.D.)

  3. Detection of radiation-induced hydrocarbons in baked sponge cake prepared with irradiated liquid egg

    International Nuclear Information System (INIS)

    Schulzki, G.; Spiegelberg, A.; Boegl, K.W.; Schreiber, G.A.

    1995-01-01

    For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of this fast and efficient technique is demonstrated by the example of detection of radiation-induced HC in fat isolated from baked sponge cake which had been prepared with irradiated liquid egg. (Author)

  4. Detection of radiation-induced hydrocarbons in baked sponged cake prepared with irradiated liquid egg

    Science.gov (United States)

    Schulzki, G.; Spiegelberg, A.; Bögl, K. W.; Schreiber, G. A.

    1995-02-01

    For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of this fast and efficient technique is demonstrated by the example of detection of radiation-induced HC in fat isolated from baked sponge cake which had been prepared with irradiated liquid egg.

  5. Radiation detection with Nb/Al-AlOx/Al/Nb superconducting tunnel junctions

    International Nuclear Information System (INIS)

    Matsumura, Atsuki; Takahashi, Toru; Kurakado, Masahiko

    1992-01-01

    Superconductor radiation detectors have the possibility of 20-30 times better energy resolution than that of a high resolution Si detector. We fabricated Nb/Al-AlOx/Al/Nb superconducting tunnel junctions with low leakage current. X rays were detected with large area junctions of 178x178 μm 2 . High energy resolution of 160 eV for 5.9 keV was obtained. We also fabricated series connected junctions which covers a rather large area of 4x4 mm 2 . α particles injected into the rear substrate were detected using nonthermal phonons induced by the radiations in the substrate. (author)

  6. Detection capabilities and accuracy requirements of concentrations of radioactive material in air for radiation protection purposes

    International Nuclear Information System (INIS)

    Brodsky, A.

    1987-01-01

    Recent developments in the formulation of detection capability and accuracy criteria for bioassay measurements will be interpreted and adapted to provide similar criteria for the measurement of air concentrations of radioactive material for radiation protection purposes. Considerations of accuracy will be related to the known variability of measurement processes, as well as the uncertainties in the calculated limits of intake that serve as the basis of regulatory and voluntary standards of practice. Formulations and criteria will be presented for minimum detection amounts (MDA) and precision and bias of measurements for radiation protection purposes. 17 references

  7. Transient photoconductive gain in a-Si:H devices and its applications in radiation detection

    International Nuclear Information System (INIS)

    Lee, H.K.; Suh, T.S.; Choe, B.Y.; Shinn, K.S.; Perez-Mendez, V.

    1997-01-01

    Using the transient behavior of the photoconductive-gain mechanism, a signal gain in radiation detection with a-Si:H devices may be possible. The photoconductive gain mechanism in two types of hydrogenated amorphous silicon devices, p-i-n and n-i-n configurations, was investigated in connection with applications to radiation detection. Photoconductive gain was measured in two time scales: one for short pulses of visible light ( 2 . Various gain results are discussed in terms of the device structure, applied bias and dark-current density. (orig.)

  8. Detection matrix of an electromagnetic radiation and radiological image intensifier comprising such a matrix

    International Nuclear Information System (INIS)

    Fraleux, Jean.

    1982-01-01

    This invention concerns a detection matrix comprising, in an electrode lattice of lines and columns, addressing means constituted of thin film technology MOS transistors and photoconductances which enable the number of unit module crossings to be halved and to bring about an increase in the effective detection area. This detection matrix is employed in radiological image intensifiers where it ensures the conversion of incident X photons into reading electric signals or only the detection of a visible radiation in the case where the incident X photons are converted into lesser energy photons by a scintillator. The scintillator is then formed of a panel brought into contact with the detector mosaic [fr

  9. Ultrafast Science Opportunities with Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    DURR, HERMANN; Wang, X.J., ed.

    2016-04-28

    X-rays and electrons are two of the most fundamental probes of matter. When the Linac Coherent Light Source (LCLS), the world’s first x-ray free electron laser, began operation in 2009, it transformed ultrafast science with the ability to generate laser-like x-ray pulses from the manipulation of relativistic electron beams. This document describes a similar future transformation. In Transmission Electron Microscopy, ultrafast relativistic (MeV energy) electron pulses can achieve unsurpassed spatial and temporal resolution. Ultrafast temporal resolution will be the next frontier in electron microscopy and can ideally complement ultrafast x-ray science done with free electron lasers. This document describes the Grand Challenge science opportunities in chemistry, material science, physics and biology that arise from an MeV ultrafast electron diffraction & microscopy facility, especially when coupled with linac-based intense THz and X-ray pump capabilities.

  10. Ultrafast, laser-based, x-ray science: the dawn of atomic-scale cinematography

    International Nuclear Information System (INIS)

    Barty, C.P.J.

    2000-01-01

    The characteristics of ultrafast chirped pulse amplification systems are reviewed. Application of ultrafast chirped pulse amplification to the generation of femtosecond, incoherent, 8-keV line radiation is outlined and the use of femtosecond laser-based, x-rays for novel time-resolved diffraction studies of crystalline dynamics with sub-picosecond temporal resolution and sub-picometer spatial resolution is reviewed in detail. Possible extensions of laser-based, x-ray technology and evaluation of alternative x-ray approaches for time-resolved studies of the atomic scale dynamics are given. (author)

  11. Ultrafast, laser-based, x-ray science: the dawn of atomic-scale cinematography

    Energy Technology Data Exchange (ETDEWEB)

    Barty, C.P.J. [University of California, Department of Applied Mechanics and Engineering Science, Urey Hall, Mali Code 0339, San Diego, La Jolla, CA (United States)

    2000-03-01

    The characteristics of ultrafast chirped pulse amplification systems are reviewed. Application of ultrafast chirped pulse amplification to the generation of femtosecond, incoherent, 8-keV line radiation is outlined and the use of femtosecond laser-based, x-rays for novel time-resolved diffraction studies of crystalline dynamics with sub-picosecond temporal resolution and sub-picometer spatial resolution is reviewed in detail. Possible extensions of laser-based, x-ray technology and evaluation of alternative x-ray approaches for time-resolved studies of the atomic scale dynamics are given. (author)

  12. Current state of commercial radiation detection equipment for homeland security applications

    International Nuclear Information System (INIS)

    Klann, R.T.; Shergur, J.; Mattesich, G.

    2009-01-01

    With the creation of the U.S. Department of Homeland Security (DHS) came the increased concern that terrorist groups would attempt to manufacture and use an improvised nuclear device or radiological dispersal device. As such, a primary mission of DHS is to protect the public against the use of these devices and to assist state and local responders in finding, locating, and identifying these types of devices and materials used to manufacture these devices. This assistance from DHS to state and local responders comes in the form of grant money to procure radiation detection equipment. In addition to this grant program, DHS has supported the development of American National Standards Institute standards for radiation detection equipment and has conducted testing of commercially available instruments. This paper identifies the types and kinds of commercially available equipment that can be used to detect and identify radiological material - for use in traditional search applications as well as primary and secondary screening of personnel, vehicles, and cargo containers. In doing so, key considerations for the conduct of operations are described as well as critical features of the instruments for specific applications. The current state of commercial instruments is described for different categories of detection equipment including personal radiation detectors, radioisotope identifiers, man-portable detection equipment, and radiation portal monitors. In addition, emerging technologies are also discussed, such as spectroscopic detectors and advanced spectroscopic portal monitors

  13. Performance test of SKIROC II ASIC chip for the radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Jun, W. J.; Namgoong, H.; Kim, B. K.; Song, H. S.; Kim, H. S.; Lee, S. H.; Choi, H. J.; Ghergherehchi, M.; Chai, J. S. [Sungkyunkwan University, Suwon (Korea, Republic of)

    2017-04-15

    There is a PCB board called FEV8 board which can readout analog signal from any energy source, and amplify it for signal processing. For precise detection, the board had been designed to operate in wide range of energy condition, with high-resolutive detection performance. This function has the possibility of the utilization for the radiation detection. The channels of the prototype board must be evaluated to make sure that the board is perfect or not. This research had made an progress for the radiation detection as well as the electronics of the intricate combination of the measurement instrumentations. The number of the noisy channels had been measured for threshold scan, and every channels in the board had been evaluated. By improving the experimental conditions such as test script in Linux system or well designed ground condition of the test bench, much more clean data will be able to be acquisited.

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

    Science.gov (United States)

    Bell, Zane W.

    2000-01-01

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

  15. Radiation Detection and Classification of Heavy Oxide Inorganic Scintillator Crystals for Detection of Fast Neutrons

    Science.gov (United States)

    2016-06-01

    response, diffuse source, collimated source 15. NUMBER OF PAGES 101 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18...protecting the homeland, building security globally, and projecting power and winning decisively [1]. Nuclear material detection is embedded in two...detection. According to Glasstone and Dolan [4] as well as numerous other experts, there are fundamentally three isotopes that could practically be used

  16. Echo detected EPR as a tool for detecting radiation-induced defect signals in pottery

    International Nuclear Information System (INIS)

    Zoleo, Alfonso; Bortolussi, Claudia; Brustolon, Marina

    2011-01-01

    Archaeological fragments of pottery have been investigated by using CW-EPR and Echo Detected EPR (EDEPR). EDEPR allows to remove the CW-EPR dominant Fe(III) background spectrum, hiding much weaker signals potentially useful for dating purpose. EDEPR spectra attributed to a methyl radical and to feldspar defects have been recorded at room and low temperature for an Iron Age cooking ware (700 B.C.). A study on the dependence of EDEPR intensity over absorbed dose on a series of γ-irradiated brick samples (estimated age of 562 ± 140 B.C.) has confirmed the potential efficacy of the proposed method for spotting defect signals out of the strong iron background. - Highlights: → Fe(III) CW-EPR signals cover CW-EPR-detectable defects in ceramics. → Echo detected EPR gets rid of Fe(III) signals, disclosing defect signals. → Echo detected EPR detects defect signals even at relatively low doses.

  17. Solving Inverse Detection Problems Using Passive Radiation Signatures

    International Nuclear Information System (INIS)

    Favorite, Jeffrey A.; Armstrong, Jerawan C.; Vaquer, Pablo A.

    2012-01-01

    The ability to reconstruct an unknown radioactive object based on its passive gamma-ray and neutron signatures is very important in homeland security applications. Often in the analysis of unknown radioactive objects, for simplicity or speed or because there is no other information, they are modeled as spherically symmetric regardless of their actual geometry. In these presentation we discuss the accuracy and implications of this approximation for decay gamma rays and for neutron-induced gamma rays. We discuss an extension of spherical raytracing (for uncollided fluxes) that allows it to be used when the exterior shielding is flat or cylindrical. We revisit some early results in boundary perturbation theory, showing that the Roussopolos estimate is the correct one to use when the quantity of interest is the flux or leakage on the boundary. We apply boundary perturbation theory to problems in which spherically symmetric systems are perturbed in asymmetric nonspherical ways. We apply mesh adaptive direct search (MADS) algorithms to object reconstructions. We present a benchmark test set that may be used to quantitatively evaluate inverse detection methods.

  18. Detection of a stochastic background of gravitational radiation by the Doppler tracking of spacecraft

    International Nuclear Information System (INIS)

    Mashhoon, B.; Grishchuk, L.P.

    1980-01-01

    The possibility of detection of an isotropic background gravitational radiation of a stochastic nature by the method of Doppler tracking of spacecraft is considered. In the geometrical optics limit, the general formula for the frequency shift of an electromagnetic signal in the gravitational radiation field is discussed, and it is shown to be gauge (or rather Lie) independent. A detailed examination of the propagation of a free electromagnetic wave in a gravitational radiation field shows that no resonance phenomena can be expected. Thus, the results valid in the geometrical optics limit are also approximately valid for any gravitational radiation spectrum dominated by wavelengths large compared to that of the electromagnetic signal. The ''Doppler noise'' due to a stochastic background is evaluated, and it is shown to depend on the total energy density of the background and a parameter that is a characteristic of the aradiation spectrum and the detection system used. A background gravitational radiation with an energy density comparable to the electromagnetic (approx.3 K) background and a spectrum dominated by wavelengths > or approx. =1 AU may be detectable in the near future by the Doppler tracking of interplanetary spacecraft

  19. Nitrogen deficiency detection using reflected shortwave radiation from irrigated corn canopies

    International Nuclear Information System (INIS)

    Blackmer, T.M.; Schepers, J.S.; Varvel, G.E.; Walter-Shea, E.A.

    1996-01-01

    Techniques that measure the N status of corn (Zea mays L.) can aid in management decisions that have economic and environmental implications. This study was conducted to identify reflected electromagnetic wavelengths most sensitive to detecting N deficiencies in a corn canopy with the possibility for use as a management tool. Reflected shortwave radiation was measured from an irrigated corn N response trial with four hybrids and five N rates at 0, 40, 80, 120, and 160 kg N ha -1 in 1992 and 0, 50, 100, 150, and 200 kg N ha -1 in 1993. A portable spectroradiometer was used to measure reflected radiation (400-1100 nm in 1992, 350-1050 nm in 1993) from corn canopies at approximately the R5 growth stage. Regression analyses revealed that reflected radiation near 550 and 710 nm was superior to reflected radiation near 450 or 650 nm for detecting N deficiencies. The ratio of light reflectance between 550 and 600 nm to light reflectance between 800 and 900 nm also provided sensitive detection of N stress. In 1993, an inexpensive photometric cell, which has peak sensitivity to light centered at 550 nm, was also used to measure reflected radiation from a corn canopy. Photometric cell readings correlated with relative grain yield (P < 0.001, r 2 = 0.74), but more research will be required to develop procedures to account for varying daylight conditions. These results provide information needed for the development of variable-rate fertilizer N application technology. (author)

  20. 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

  1. Electronic and structural response of nanomaterials to ultrafast and ultraintense laser pulses.

    Science.gov (United States)

    Jiang, Chen-Wei; Zhou, Xiang; Lin, Zhibin; Xie, Rui-Hua; Li, Fu-Li; Allen, Roland E

    2014-02-01

    The interaction of materials with ultrafast and ultraintense laser pulses is a current frontier of science both experimentally and theoretically. In this review, we briefly discuss some recent theoretical studies by the present authors with our method of semiclassical electron-radiation-ion dynamics (SERID). In particular, Zhou et al. and Jiang et al. respectively, determined the optimal duration and optimal timing for a series of femtosecond scale laser pulses to excite a specific vibrational mode in a general chemical system. A set of such modes can be used as a "fingerprint" for characterizing a particular molecule or a complex in a solid. One can therefore envision many applications, ranging from fundamental studies to detection of chemical or biological agents. Allen et al. proved that dimers are preferentially emitted during photofragmentation of C60 under an ultrafast and ultraintense laser pulse. For interactions between laser pulses and semiconductors, e.g., GaAs, Si and InSb, besides experimentally accessible optical properties--epsilon(omega) and chi(2)-Allen et al. offered many other indicators to confirm the nonthermal nature of structural changes driven by electronic excitations and occurring during the first few hundred femtoseconds. Lin et al. found that, after the application of a femtosecond laser pulse, excited electrons in materials automatically equilibrate to a Fermi-Dirac distribution within roughly 100 fs, solely because of their coupling to the nuclear motion, even though the resulting electronic temperature is one to two orders of magnitude higher than the kinetic temperature defined by the nuclear motion.

  2. Magnetic resonance urography in pediatrics: utilization of ultrafast single-shot spin echo sequences

    International Nuclear Information System (INIS)

    Martin, C.; Martin, J.; Duran, C.; Rigol, S.; Rojo, J. C.

    1999-01-01

    To determine the value of magnetic resonance urography (MRU) using ultrafast single-shot (SS) rapid acquisition with relaxation enhancement (RARE) and half-Fourier (HF) SS-RARE (SS-HF-RARE or HASTE) in the evaluation of congenital urinary tract anomalies in pediatric patients, and their possible application as alternatives to intravenous urography (IVU). Eighteen children (11 boys and 7 girls) aged 2 months to 15 years (mean: 5 years) with a total of 19 congenital urinary tract anomalies were studies by MU using SS-RARE and HASTE sequences in a 1 Tesla scanner. All the patients had previously been studies by ultrasound (US) and IVU. Twelve patients required anesthesia. The images were acquired by means of a HASTE sequence with multisection technique (TR, infinite; TE e f, 87 msec; echo train, 128; interval between echoes, 10.9 msec; total acquisition time, 13 sections/12 seconds), and SS-RARE (TR, infinite; TE e f, 1.100 msec; echo train, 240, and acquisition time, 7 seconds). Four radiologists evaluated the images independently; two who reviewed the IV images in consensus and two who reviewed the MRU images in consensus. The images were evaluated to assess the dilatation of the urinary tract and their utility in detecting the level and cause of the obstruction. MRU images revealed the urinary tract dilation, the level of the obstruction and the type of anomaly in 18 patients (100%), while IVU provided this information in only 10 [ sensitivity, 53%, 95% confidence interval (29%, 76%)]. The mean time required for MRU was 20 minutes (range: 7 to 30 minutes), while that of IVU was 1,242 minutes (range: 45 to 1,440 minutes). MRU using ultrafast single-short spin echo sequences is a rapid and effective technique that permits and excellent evaluation of congenital urinary tract anomalies in pediatric patients and does not require the administration of contrast media or ionizing radiation. (Author) 10 refs

  3. High speed fluorescence imaging with compressed ultrafast photography

    Science.gov (United States)

    Thompson, J. V.; Mason, J. D.; Beier, H. T.; Bixler, J. N.

    2017-02-01

    Fluorescent lifetime imaging is an optical technique that facilitates imaging molecular interactions and cellular functions. Because the excited lifetime of a fluorophore is sensitive to its local microenvironment,1, 2 measurement of fluorescent lifetimes can be used to accurately detect regional changes in temperature, pH, and ion concentration. However, typical state of the art fluorescent lifetime methods are severely limited when it comes to acquisition time (on the order of seconds to minutes) and video rate imaging. Here we show that compressed ultrafast photography (CUP) can be used in conjunction with fluorescent lifetime imaging to overcome these acquisition rate limitations. Frame rates up to one hundred billion frames per second have been demonstrated with compressed ultrafast photography using a streak camera.3 These rates are achieved by encoding time in the spatial direction with a pseudo-random binary pattern. The time domain information is then reconstructed using a compressed sensing algorithm, resulting in a cube of data (x,y,t) for each readout image. Thus, application of compressed ultrafast photography will allow us to acquire an entire fluorescent lifetime image with a single laser pulse. Using a streak camera with a high-speed CMOS camera, acquisition rates of 100 frames per second can be achieved, which will significantly enhance our ability to quantitatively measure complex biological events with high spatial and temporal resolution. In particular, we will demonstrate the ability of this technique to do single-shot fluorescent lifetime imaging of cells and microspheres.

  4. Intensified CCD for ultrafast diagnostics

    International Nuclear Information System (INIS)

    Cheng, J.; Tripp, G.; Coleman, L.

    1978-01-01

    Many of the present laser fusion diagnostics are recorded on either ultrafast streak cameras or on oscilloscopes. For those experiments in which a large volume of data is accumulated, direct computer processing of the information becomes important. We describe an approach which uses a RCA 52501 back-thinned CCD sensor to obtain direct electron readouts for both the streak camera and the CRT. Performance of the 100 GHz streak camera and the 4 GHz CRT are presented. Design parameters and computer interfacing for both systems are described in detail

  5. Compression of Ultrafast Laser Beams

    Science.gov (United States)

    2016-03-01

    Copyright 2003, AIP Publishing LLC. DOI: http://dx.doi.org/10.1063/1.1611998.) When designing the pulse shaper, the laser beam must completely fill the...for the design of future versions of this device. The easiest way to align the pulse shaper is to use the laser beam that will be shaped, without...Afterward, an ultrafast thin beam splitter is placed into the system after the diameter of the laser beam is reduced; this is done to monitor the beam

  6. WE-B-210-02: The Advent of Ultrafast Imaging in Biomedical Ultrasound

    International Nuclear Information System (INIS)

    Tanter, M.

    2015-01-01

    In the last fifteen years, the introduction of plane or diverging wave transmissions rather than line by line scanning focused beams has broken the conventional barriers of ultrasound imaging. By using such large field of view transmissions, the frame rate reaches the theoretical limit of physics dictated by the ultrasound speed and an ultrasonic map can be provided typically in tens of micro-seconds (several thousands of frames per second). Interestingly, this leap in frame rate is not only a technological breakthrough but it permits the advent of completely new ultrasound imaging modes, including shear wave elastography, electromechanical wave imaging, ultrafast doppler, ultrafast contrast imaging, and even functional ultrasound imaging of brain activity (fUltrasound) introducing Ultrasound as an emerging full-fledged neuroimaging modality. At ultrafast frame rates, it becomes possible to track in real time the transient vibrations – known as shear waves – propagating through organs. Such “human body seismology” provides quantitative maps of local tissue stiffness whose added value for diagnosis has been recently demonstrated in many fields of radiology (breast, prostate and liver cancer, cardiovascular imaging, …). Today, Supersonic Imagine company is commercializing the first clinical ultrafast ultrasound scanner, Aixplorer with real time Shear Wave Elastography. This is the first example of an ultrafast Ultrasound approach surpassing the research phase and now widely spread in the clinical medical ultrasound community with an installed base of more than 1000 Aixplorer systems in 54 countries worldwide. For blood flow imaging, ultrafast Doppler permits high-precision characterization of complex vascular and cardiac flows. It also gives ultrasound the ability to detect very subtle blood flow in very small vessels. In the brain, such ultrasensitive Doppler paves the way for fUltrasound (functional ultrasound imaging) of brain activity with unprecedented

  7. WE-B-210-02: The Advent of Ultrafast Imaging in Biomedical Ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Tanter, M. [Laboratoire Ondes et Acoustique (France)

    2015-06-15

    In the last fifteen years, the introduction of plane or diverging wave transmissions rather than line by line scanning focused beams has broken the conventional barriers of ultrasound imaging. By using such large field of view transmissions, the frame rate reaches the theoretical limit of physics dictated by the ultrasound speed and an ultrasonic map can be provided typically in tens of micro-seconds (several thousands of frames per second). Interestingly, this leap in frame rate is not only a technological breakthrough but it permits the advent of completely new ultrasound imaging modes, including shear wave elastography, electromechanical wave imaging, ultrafast doppler, ultrafast contrast imaging, and even functional ultrasound imaging of brain activity (fUltrasound) introducing Ultrasound as an emerging full-fledged neuroimaging modality. At ultrafast frame rates, it becomes possible to track in real time the transient vibrations – known as shear waves – propagating through organs. Such “human body seismology” provides quantitative maps of local tissue stiffness whose added value for diagnosis has been recently demonstrated in many fields of radiology (breast, prostate and liver cancer, cardiovascular imaging, …). Today, Supersonic Imagine company is commercializing the first clinical ultrafast ultrasound scanner, Aixplorer with real time Shear Wave Elastography. This is the first example of an ultrafast Ultrasound approach surpassing the research phase and now widely spread in the clinical medical ultrasound community with an installed base of more than 1000 Aixplorer systems in 54 countries worldwide. For blood flow imaging, ultrafast Doppler permits high-precision characterization of complex vascular and cardiac flows. It also gives ultrasound the ability to detect very subtle blood flow in very small vessels. In the brain, such ultrasensitive Doppler paves the way for fUltrasound (functional ultrasound imaging) of brain activity with unprecedented

  8. Process and devices of detection of hard electromagnetic or particle radiations using a superconducting element

    International Nuclear Information System (INIS)

    Drukier, A.K.; Valette, Claude; Waysand, Georges.

    1975-01-01

    The invention relates to processes and systems for the detection of hard electromagnetic or particle radiations and the sensors fitted to these systems. 'Hard radiations' means those whose energy is greater than a variable threshold, depending on the applications, but always more than 5 keV. The use of these sensors and the associated systems can therefore be envisaged in radiography and also in emission gammagraphy in the biological, anatomic and medical fields. In these processes, in order to detect a photon or a radiation particle, use is made of the transition phenomenon of a homogeneous grain of superconducting material of the first kind, from the metastable superconducting state to the normal state, under the effect of a photoelectron ejected by the impact of the photon or of the particle on the grain of superconducting material [fr

  9. Polarization sensitive detection of 100 GHz radiation by high mobility field-effect transistors

    International Nuclear Information System (INIS)

    Sakowicz, M.; Lusakowski, J.; Karpierz, K.; Grynberg, M.; Knap, W.; Gwarek, W.

    2008-01-01

    Detection of 100 GHz electromagnetic radiation by a GaAs/AlGaAs high electron mobility field-effect transistor was investigated at 300 K as a function of the angle α between the direction of linear polarization of the radiation and the symmetry axis of the transistor. The angular dependence of the detected signal was found to be A 0 cos 2 (α-α 0 )+C with A 0 , α 0 , and C dependent on the electrical polarization of the transistor gate. This dependence is interpreted as due to excitation of two crossed phase-shifted oscillators. A response of the transistor chip (including bonding wires and the substrate) to 100 GHz radiation was numerically simulated. Results of calculations confirmed experimentally observed dependencies and showed that the two oscillators result from an interplay of 100 GHz currents defined by the transistor impedance together with bonding wires and substrate related modes

  10. Performance Analysis of Si-Based Ultra-Shallow Junction Photodiodes for UV Radiation Detection

    NARCIS (Netherlands)

    Shi, L.

    2013-01-01

    This thesis presents a performance investigation of newly-developed ultra-shallow junction photodiodes (PureB-diodes) for ultraviolet (UV) radiation detection. The photodiodes are fabricated by pure boron chemical vapor deposition (PureB CVD) technology, which can provide nanometer-thin boron

  11. Detecting part of the transition radiation detector for the GINES installation at UNK

    International Nuclear Information System (INIS)

    Shikhliarov, K.K.; Gavalian, V.G.; Aginian, M.A.

    1995-01-01

    The detecting part of an X-ray transition radiation detector based on thin-walled mylar straws is considered in this paper. The performance of xenon-filled straws in the self-quenching mode is studied in detail. The measurements have been carried out both with radioactive sources and under the electron beam of the Yerevan synchrotron. (orig.)

  12. Development of front-end ASIC for radiation detection and measurement

    International Nuclear Information System (INIS)

    Shimazoe, K.

    2014-01-01

    For realizing the multichannel spectroscopy of gamma rays, the technology of integrated circuits is necessary. Multi-channel gamma ray spectroscopy is very important for many applications including the medical imaging and the environmental monitoring. The current progress in the development of application specific integrated circuit (ASIC) for multi-channel radiation detection is introduced and reviewed. (author)

  13. Operating a Microwave Radiation Detection Monitor. Module 10. Vocational Education Training in Environmental Health Sciences.

    Science.gov (United States)

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on operating a microwave radiation detection monitor. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) testing the…

  14. Design and construction of tank robot for detection and searching of radiation sources

    International Nuclear Information System (INIS)

    Rio Isman; Djiwo Harsono; Adi Abimanyu

    2016-01-01

    Developments of robotics technology can be implemented for searching the lost radiation source. Radiation source lost case allows the radiation dose exceeding NBD received by radiation worker when security precautions are taken. This research propose a robot tank that can help in detection and searching radiation sources. The robot consists of a micro controller board Arduino Mega 2560, XBee Pro S radio frequency modules, Gaps receiver U-B lox Neo-Mn-0-01, a servo motor and two DC motors. In this research, the amount of radiation is calculated in 0-5 volt analog voltage that is simulated using a potentiometer and then converted to a digital voltage value (0-1023) using ADC 10 bit Arduino Mega 2560. Results of the research show that the robot has a size of 28.7 cm x 24.8 cm x 11 cm, able to move forward with a speed of 0.477 m/s and are capable to rotate in 24 angles. Data transmission can be performed wireless up to 113 m in an open area without any changes of format and length of the data. Robot capable to rotate and move towards the angle which has the largest voltage readings so can predict the location of the radiation source. (author)

  15. MRI-alone radiation therapy planning for prostate cancer: Automatic fiducial marker detection

    International Nuclear Information System (INIS)

    Ghose, Soumya; Mitra, Jhimli; Rivest-Hénault, David; Fazlollahi, Amir; Fripp, Jurgen; Dowling, Jason A.; Stanwell, Peter; Pichler, Peter; Sun, Jidi; Greer, Peter B.

    2016-01-01

    Purpose: The feasibility of radiation therapy treatment planning using substitute computed tomography (sCT) generated from magnetic resonance images (MRIs) has been demonstrated by a number of research groups. One challenge with an MRI-alone workflow is the accurate identification of intraprostatic gold fiducial markers, which are frequently used for prostate localization prior to each dose delivery fraction. This paper investigates a template-matching approach for the detection of these seeds in MRI. Methods: Two different gradient echo T1 and T2* weighted MRI sequences were acquired from fifteen prostate cancer patients and evaluated for seed detection. For training, seed templates from manual contours were selected in a spectral clustering manifold learning framework. This aids in clustering “similar” gold fiducial markers together. The marker with the minimum distance to a cluster centroid was selected as the representative template of that cluster during training. During testing, Gaussian mixture modeling followed by a Markovian model was used in automatic detection of the probable candidates. The probable candidates were rigidly registered to the templates identified from spectral clustering, and a similarity metric is computed for ranking and detection. Results: A fiducial detection accuracy of 95% was obtained compared to manual observations. Expert radiation therapist observers were able to correctly identify all three implanted seeds on 11 of the 15 scans (the proposed method correctly identified all seeds on 10 of the 15). Conclusions: An novel automatic framework for gold fiducial marker detection in MRI is proposed and evaluated with detection accuracies comparable to manual detection. When radiation therapists are unable to determine the seed location in MRI, they refer back to the planning CT (only available in the existing clinical framework); similarly, an automatic quality control is built into the automatic software to ensure that all gold

  16. MRI-alone radiation therapy planning for prostate cancer: Automatic fiducial marker detection

    Energy Technology Data Exchange (ETDEWEB)

    Ghose, Soumya, E-mail: soumya.ghose@case.edu; Mitra, Jhimli [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 and CSIRO Health and Biosecurity, The Australian e-Health & Research Centre, Herston, QLD 4029 (Australia); Rivest-Hénault, David; Fazlollahi, Amir; Fripp, Jurgen; Dowling, Jason A. [CSIRO Health and Biosecurity, The Australian e-Health & Research Centre, Herston, QLD 4029 (Australia); Stanwell, Peter [School of health sciences, The University of Newcastle, Newcastle, NSW 2308 (Australia); Pichler, Peter [Department of Radiation Oncology, Cavalry Mater Newcastle Hospital, Newcastle, NSW 2298 (Australia); Sun, Jidi; Greer, Peter B. [School of Mathematical and Physical Sciences, The University of Newcastle, Newcastle, NSW 2308, Australia and Department of Radiation Oncology, Cavalry Mater Newcastle Hospital, Newcastle, NSW 2298 (Australia)

    2016-05-15

    Purpose: The feasibility of radiation therapy treatment planning using substitute computed tomography (sCT) generated from magnetic resonance images (MRIs) has been demonstrated by a number of research groups. One challenge with an MRI-alone workflow is the accurate identification of intraprostatic gold fiducial markers, which are frequently used for prostate localization prior to each dose delivery fraction. This paper investigates a template-matching approach for the detection of these seeds in MRI. Methods: Two different gradient echo T1 and T2* weighted MRI sequences were acquired from fifteen prostate cancer patients and evaluated for seed detection. For training, seed templates from manual contours were selected in a spectral clustering manifold learning framework. This aids in clustering “similar” gold fiducial markers together. The marker with the minimum distance to a cluster centroid was selected as the representative template of that cluster during training. During testing, Gaussian mixture modeling followed by a Markovian model was used in automatic detection of the probable candidates. The probable candidates were rigidly registered to the templates identified from spectral clustering, and a similarity metric is computed for ranking and detection. Results: A fiducial detection accuracy of 95% was obtained compared to manual observations. Expert radiation therapist observers were able to correctly identify all three implanted seeds on 11 of the 15 scans (the proposed method correctly identified all seeds on 10 of the 15). Conclusions: An novel automatic framework for gold fiducial marker detection in MRI is proposed and evaluated with detection accuracies comparable to manual detection. When radiation therapists are unable to determine the seed location in MRI, they refer back to the planning CT (only available in the existing clinical framework); similarly, an automatic quality control is built into the automatic software to ensure that all gold

  17. Graphene Field Effect Transistor-Based Detectors for Detection of Ionizing Radiation

    International Nuclear Information System (INIS)

    Jovanovic, Igor; Cazalas, Edward; Childres, I.; Patil, A.; Koybasi, O.; Chen, Y-P.

    2013-06-01

    We present the results of our recent efforts to develop novel ionizing radiation sensors based on the nano-material graphene. Graphene used in the field effect transistor architecture could be employed to detect the radiation-induced charge carriers produced in undoped semiconductor absorber substrates, even without the need for charge collection. The detection principle is based on the high sensitivity of graphene to ionization-induced local electric field perturbations in the electrically biased substrate. We experimentally demonstrated promising performance of graphene field effect transistors for detection of visible light, X-rays, gamma-rays, and alpha particles. We propose improved detector architectures which could result in a significant improvement of speed necessary for pulsed mode operation. (authors)

  18. A method to detect ultra high energy electrons using earth's magnetic field as a radiator

    Science.gov (United States)

    Stephens, S. A.; Balasubrahmanyan, V. K.

    1983-01-01

    It is pointed out that the detection of electrons with energies exceeding a few TeV, which lose energy rapidly through synchrotron and inverse Compton processes, would provide valuable information on the distribution of sources and on the propagation of cosmic rays in the solar neighborhood. However, it would not be possible to measure the energy spectrum beyond a few TeV with any of the existing experimental techniques. The present investigation is, therefore concerned with the possibility of detecting electrons with energies exceeding a few TeV on the basis of the photons emitted through synchrotron radiation in the earth's magnetic field. Attention is given to the synchrotron radiation of electrons in the earth's magnetic field, detector response and energy estimation, and the characteristics of an ideal detector, capable of detecting photons with energies equal to or greater than 20 keV.

  19. Design of a spreader bar crane-mounted gamma-ray radiation detection system

    Energy Technology Data Exchange (ETDEWEB)

    Grypp, Matthew D., E-mail: iglowgreen@neo.tamu.edu; Marianno, Craig M., E-mail: marianno@tamu.edu; Poston, John W., E-mail: j-poston@tamu.edu; Hearn, Gentry C., E-mail: ghearn@riacc.com

    2014-04-11

    Over 95% of imports entering the United States from outside North America arrive by sea at 329 ports of entry. These imports are packaged in more than 11 million cargo containers. Radiation portals monitors routinely scan cargo containers leaving port on specially-designed trucks. To accelerate the process, some commercial entities have placed detection systems on the spreader-bar cranes (SBCs) used to offload. Little is known about the radiation background profiles of systems operating on these cranes. To better understand the operational characteristics of these radiation detection systems; a research team from Texas A and M University (TAMU) mounted three thallium-doped sodium iodide [NaI(Tl)] detectors on an SBC at the Domestic Nuclear Detection Office's (DNDO) test track facility at the Port of Tacoma (PoT). These detectors were used to monitor background radiation levels and continuously recorded data during crane operations using a custom-built software package. Count rates and spectral data were recorded for various crane heights over both land and water. The results of this research created a background profile in which count rate was heavily dependent on position demonstrating how detector readings changed in the operational environment.

  20. Destruction of Raman biosignatures by ionising radiation and the implications for life detection on Mars.

    Science.gov (United States)

    Dartnell, Lewis R; Page, Kristian; Jorge-Villar, Susana E; Wright, Gary; Munshi, Tasnim; Scowen, Ian J; Ward, John M; Edwards, Howell G M

    2012-04-01

    Raman spectroscopy has proven to be a very effective approach for the detection of microorganisms colonising hostile environments on Earth. The ExoMars rover, due for launch in 2018, will carry a Raman laser spectrometer to analyse samples of the martian subsurface collected by the probe's 2-m drill in a search for similar biosignatures. The martian surface is unprotected from the flux of cosmic rays, an ionising radiation field that will degrade organic molecules and so diminish and distort the detectable Raman signature of potential martian microbial life. This study employs Raman spectroscopy to analyse samples of two model organisms, the cyanobacterium Synechocystis sp. PCC 6803 and the extremely radiation resistant polyextremophile Deinococcus radiodurans, that have been exposed to increasing doses of ionising radiation. The three most prominent peaks in the Raman spectra are from cellular carotenoids: deinoxanthin in D. radiodurans and β-carotene in Synechocystis. The degradative effect of ionising radiation is clearly seen, with significant diminishment of carotenoid spectral peak heights after 15 kGy and complete erasure of Raman biosignatures by 150 kGy of ionising radiation. The Raman signal of carotenoid in D. radiodurans diminishes more rapidly than that of Synechocystis, believed to be due to deinoxanthin acting as a superior scavenger of radiolytically produced reactive oxygen species, and so being destroyed more quickly than the less efficient antioxidant β-carotene. This study highlights the necessity for further experimental work on the manner and rate of degradation of Raman biosignatures by ionising radiation, as this is of prime importance for the successful detection of microbial life in the martian near subsurface.

  1. Instrumentation measurement and testing complex for detection and identification of radioactive materials using the emitted radiation

    International Nuclear Information System (INIS)

    Samossadny, V.T.; Dmitrenko, V.V.; Kadlin, V.V.; Kolesnikov, S.V.; Ulin, S.E.; Grachev, V.M.; Vlasik, K.F.; Dedenko, G.L.; Novikov, D.V.; Uteshev, Z.M.

    2006-01-01

    Simultaneous measurement of neutron and gamma radiation is a very usefull method for effective nuclear materials identification and control. The gamma-ray-neutron complex described in the paper is based on two multi-layer 3 He neutrons detectors and two High Pressure Xenon gamma-ray spectrometers assembled in one unit. All these detectors were callibrated on neutron and gamma-ray sources. The main characteristics of the instrumentation , its testing results and gamma-ray and neutron radiation parameters, which have been measured are represented in the paper. The gamma-neutron sources and fissile materials reliable detection and identification capability was demonstrated

  2. Accuracy and detection limits for bioassay measurements in radiation protection. Statistical considerations

    International Nuclear Information System (INIS)

    Brodsky, A.

    1986-04-01

    This report provides statistical concepts and formulas for defining minimum detectable amount (MDA), bias and precision of sample analytical measurements of radioactivity for radiobioassay purposes. The defined statistical quantities and accuracy criteria were developed for use in standard performance criteria for radiobioassay, but are also useful in intralaboratory quality assurance programs. This report also includes a literature review and analysis of accuracy needs and accuracy recommendations of national and international scientific organizations for radiation or radioactivity measurements used for radiation protection purposes. Computer programs are also included for calculating the probabilities of passing or failing multiple analytical tests for different acceptable ranges of bias and precision

  3. Fast MR imaging and ultrafast MR imaging of fetal central nervous system abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Shakudo, Miyuki; Manabe, Takao; Murata, Katsuko; Matsuo, Ryoichi; Oda, Junro [Osaka City General Hospital (Japan); Inoue, Yuichi; Mochizuki, Kunizo; Yamada, Ryusaku

    2001-12-01

    The aims of this study were two: to compare the efficacy of fast MRI (breath-hold fast spin-echo T2-weighted and fast gradient-echo T1-weighted sequence) and ultrafast MRI (half-Fourier acquisition single-shot turbo spin-echo sequence) in evaluation of fetal central nervous system (CNS) abnormalities at late gestational age, and to compare the capability of fast MRI and ultrafast MRI to assess fetal CNS abnormalities with that of prenatal ultrasonography (US). Forty-nine women with fetuses at gestational ages of 26-39 weeks underwent fast MRI (29 patients) or ultrafast MRI (20 patients). In detection of motion artifact, visualization of the lateral and 4th ventricles, and differentiation between gray and white matter in cerebral hemispheres, ultrafast MRI was significantly superior to fast MRI (p<0.0001, Mann-Whitney U test). In 25 of 43 cases, US and MR diagnoses were the same and consistent with postnatal diagnosis. In 10 of 43 cases, MRI demonstrated findings additional to or different from those of US, and MR findings were confirmed postnatally. MRI, particularly ultrafast MRI, is useful for demonstrating CNS abnormalities in situations in which US is suggestive but not definitive. (author)

  4. Biochemical and Radiobiological Factors in the Early Detection of Radiation Injury in Mammals

    Energy Technology Data Exchange (ETDEWEB)

    Cole, L. J. [Life Sciences Division, Stanford Research Institute, Menlo Park, CA (United States)

    1971-03-15

    In considering the body of radiobiological knowledge upon which the present possibilities for the development of an objective quantitative laboratory procedure for early detection of radiation injury depend, it is evident that there are at least three general categories of radiation effects which are relevant to this objective: (1) Products of the enzymatic-chemical breakdown of macromolecules, and lysis of killed or dying cells from radiosensitive tissues, for example deoxypolynucleotides from lymphoid tissues and bone marrow; (2) Radiation-induced inhibition of synthesis of deoxyribonucleic acid (DNA) and/or other macromolecules, eliciting alterations in tissue and blood concentrations and pool size of metabolic intermediates in the synthesis, for example, deoxycytidine; (3) Radiation-induced alterations, suppression, or cessation of specialized cell function; of particular interest here is the immunological functions of lymphocytes, including those in the circulating blood. For rodents, the exquisite radiosensitivity of bone-marrow-stem cells as well as of lymphocytes has been precisely measured by modern cellular radiobiological techniques: the colony-forming technique of Till and McCulloch, yielding a D{sub 0} for bone-marrow cells of about 80 R; and the graft-versus-host reactivity of transplanted lymphocytes yielding a similar D{sub 0} value. In our own hands, a modified colony-formation technique for dog bone-marrow cells irradiated in.vitro and in vivo give D{sub 0} values of {approx}100 R. Thus, on the basis of radiation sensitivity and the time-relationships for interphase cell death for lymphocytes, it appears that this cell class is probably the best ''candidate'' source for an early radiation-injury detection system. However,- the important report by Zicha and Buric indicates that extrapolation of biochemical data on radiation dosimetry from rodents to man is not necessarily feasible, at least in the. case of the urinary excretion of deoxycytidine

  5. Detecting ship targets in spaceborne infrared image based on modeling radiation anomalies

    Science.gov (United States)

    Wang, Haibo; Zou, Zhengxia; Shi, Zhenwei; Li, Bo

    2017-09-01

    Using infrared imaging sensors to detect ship target in the ocean environment has many advantages compared to other sensor modalities, such as better thermal sensitivity and all-weather detection capability. We propose a new ship detection method by modeling radiation anomalies for spaceborne infrared image. The proposed method can be decomposed into two stages, where in the first stage, a test infrared image is densely divided into a set of image patches and the radiation anomaly of each patch is estimated by a Gaussian Mixture Model (GMM), and thereby target candidates are obtained from anomaly image patches. In the second stage, target candidates are further checked by a more discriminative criterion to obtain the final detection result. The main innovation of the proposed method is inspired by the biological mechanism that human eyes are sensitive to the unusual and anomalous patches among complex background. The experimental result on short wavelength infrared band (1.560 - 2.300 μm) and long wavelength infrared band (10.30 - 12.50 μm) of Landsat-8 satellite shows the proposed method achieves a desired ship detection accuracy with higher recall than other classical ship detection methods.

  6. Radiation anomaly detection algorithms for field-acquired gamma energy spectra

    Science.gov (United States)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ron; Guss, Paul; Mitchell, Stephen

    2015-08-01

    The Remote Sensing Laboratory (RSL) is developing a tactical, networked radiation detection system that will be agile, reconfigurable, and capable of rapid threat assessment with high degree of fidelity and certainty. Our design is driven by the needs of users such as law enforcement personnel who must make decisions by evaluating threat signatures in urban settings. The most efficient tool available to identify the nature of the threat object is real-time gamma spectroscopic analysis, as it is fast and has a very low probability of producing false positive alarm conditions. Urban radiological searches are inherently challenged by the rapid and large spatial variation of background gamma radiation, the presence of benign radioactive materials in terms of the normally occurring radioactive materials (NORM), and shielded and/or masked threat sources. Multiple spectral anomaly detection algorithms have been developed by national laboratories and commercial vendors. For example, the Gamma Detector Response and Analysis Software (GADRAS) a one-dimensional deterministic radiation transport software capable of calculating gamma ray spectra using physics-based detector response functions was developed at Sandia National Laboratories. The nuisance-rejection spectral comparison ratio anomaly detection algorithm (or NSCRAD), developed at Pacific Northwest National Laboratory, uses spectral comparison ratios to detect deviation from benign medical and NORM radiation source and can work in spite of strong presence of NORM and or medical sources. RSL has developed its own wavelet-based gamma energy spectral anomaly detection algorithm called WAVRAD. Test results and relative merits of these different algorithms will be discussed and demonstrated.

  7. Improvements to a neutral radiation detection and position sensitive process and devices

    International Nuclear Information System (INIS)

    Charpak, Georges; Nguyen, N.H.; Policarpo, Armando.

    1977-01-01

    This invention aims to provide a neutral radiation position sensitive process and device providing a spatial radiation satisfactory for most medical applications and an energy radiation that cannot be reached by gas detectors based on proportional counters or by scintillation counters. Only solid state detectors can compete with respect to energy resolution. The detector described enables large areas to be covered which cannot be reached at accessible costs by solid state detectors. With this aim in view, the invention suggests an incident neutral radiation and position sensitive process, particularly soft gamma and X radiations, whereby photoelectrons are made to form by incident radiation action on gas atoms contained in an enclosure. By means of an electric field, the electrons are diverted towards a space undergoing an electric field high enough in value to create photons by exciting gas atoms and returning them to the de-excited state. The photons are collected, through a transparent window, on a layer of a material for converting such photons into scintillations in the near or visible UV spectrum and the barycentre of the scintillations is positioned on the layer, for instance by photomultipliers or ionization detectors. According to another aspect of the invention, it suggests a detection and position sensitive device comprising (generally downstream of a collimator with a grid of inlet holes) a leak tight containment fitted with an inlet window transparent to incident radiations, filled with a gas producing electrons by interaction with the incident radiation, and fitted with electrodes for generating an electric field to divert the electrons to a space for creating secondary photons [fr

  8. Temporal evaluation of radiation detection system, used by the division of radiation protection of the Navy Technological Centre in Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Gontijo, Rodrigo Modesto Gadelha; Acosta, Clarice de Freitas; Ikari, Andreza Iris R.; Ferreira, Marcio de Oliveira; Alves, Henrique da Silva; Duarte, Marcelo Antonio

    2011-01-01

    This work presents a temporal evaluation of the radiation detection system used by in division of radiation protection of the CTMSP, Sao Paulo, Brazil. About fifty efficiencies results of the system were compiled over the last two years for this purpose. Less than 1% of the standard deviation was found for both portable and fixed detectors, which indicates a significant stability of the detection system used in CTMSP over the period analyzed. (author)

  9. Ultrafast THz Saturable Absorption in Doped Semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hoffmann, Matthias C.

    2011-01-01

    We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields.......We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields....

  10. Systems for detecting and recording hard corpuscular and electromagnetic radiations using a superconducting element

    International Nuclear Information System (INIS)

    Drukier, A.K.; Valette, Claude; Waysand, Georges.

    1975-01-01

    The invention relates to systems for detecting hard X ray or gamma radiations above 5 keV in energy, intended, for example, for gammagraphy by emission in the biological, anatomic and medical fields. It describes systems of the above type which directly give the image of a radiation distribution, that is to say without intermediate processing. Another purpose of the invention is to provide the devices with main memory measuring the radiation distribution, in other words systems that display the said data for as long as the operator deems necessary and that can be reset, that is to say returned to measuring conditions, immediately. The invention makes use of the properties of type I superconductors [fr

  11. Radiation pneumonitis: generalised lung changes detected by radionuclide imaging following focal lung irradiation

    International Nuclear Information System (INIS)

    Ball, D.; Sephton, R.; Irving, L.; Crennan, E.

    1992-01-01

    The usefulness of a nuclear imaging technique as a means of detecting radiation-induced lung injury is examined. The technique involves the patient inhaling modified technegas TM , a gas-like radiotracer which is an ultra fine particulate dispersion. This crosses the alveolar-capillary membrane and the clearance rate of the tracer from the lungs is presumed to reflect membrane permeability. A case of a patient who, after receiving localised radiotherapy and chemotherapy for lung cancer, developed symptoms and signs of radiation pneumonitis is reported. Pre- and post-radiotherapy investigations using the nuclear technique showed acceleration of rates of tracer clearance from both lungs, consistent with generalised changes in alveolar-capillary membrane permeability. It is suggested that the symptoms of radiation pneumonitis may in part result from pathophysiologic changes in nonirradiated lung which may appear radiologically normal. 4 refs., 2 figs

  12. Detection of radiation from a heated and modulated equatorial electrojet current system

    International Nuclear Information System (INIS)

    Lunnen, R.J.; Lee, H.S.; Ferraro, A.J.; Collins, T.W.

    1984-01-01

    In May 1983, ionospheric heating experiments were conducted using the very high frequency radar facility at Lima, Peru. Experiments involving high frequency heating of the ionosphere were successfully conducted during 1982 at Islote, Puerto Rico. These local experiments had characterized the signal radiated from a heated and modulated ionospheric current system near the mid-latitudes. A long-path signal had also been received in September 1982 at Salinas, Puerto Rico from a mid-day equatorial electrojet, heated and modulated by the Jicamarca facility. The authors have investigated the characteristics of the local signal that would be radiated from a strong equatorial electrojet when heated and modulated, and report here that at the geomagnetic equator they were similar to, but less intense than, those observed at Arecibo, Puerto Rico due to parameter differences. This radiation is believed to be the first detected from a heated and modulated equatorial electrojet current system in the Western Hemisphere. (author)

  13. Nick translation detection in situ of cellular DNA strand break induced by radiation

    International Nuclear Information System (INIS)

    Maehara, Y.; Anai, H.; Kusumoto, T.; Sakaguchi, Y.; Sugimachi, K.

    1989-01-01

    DNA strand break in HeLa cells induced by radiation was detected using the in situ nick translation method. The cells were exposed to radiation of 3, 6, 12, 18, and 24 Gy in Lab-Tek tissue culture chamber/slides and were fixed with ethanol/acetic acid on the slide glass. The break sites in DNA were translated artificially in the presence of Escherichia coli DNA polymerase I and [ 3 H]-labeled dTTP. Autoradiographic observation was made of the level of break sites in the DNA. The DNA strand break appeared even with a 3 Gy exposure, increased 8.6 times at 24 Gy compared with the control cells, and this level correlated reciprocally to change in cell viability. This nick translation method provides a rapid in situ assay for determining radiation-induced DNA damage of cultured cells, in a semi-quantitative manner

  14. Measuring proton shift tensors with ultrafast MAS NMR.

    Science.gov (United States)

    Miah, Habeeba K; Bennett, David A; Iuga, Dinu; Titman, Jeremy J

    2013-10-01

    A new proton anisotropic-isotropic shift correlation experiment is described which operates with ultrafast MAS, resulting in good resolution of isotropic proton shifts in the detection dimension. The new experiment makes use of a recoupling sequence designed using symmetry principles which reintroduces the proton chemical shift anisotropy in the indirect dimension. The experiment has been used to measure the proton shift tensor parameters for the OH hydrogen-bonded protons in tyrosine·HCl and citric acid at Larmor frequencies of up to 850 MHz. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. High speed preamplifier circuit, detection electronics, and radiation detection systems therefrom

    Science.gov (United States)

    Riedel, Richard A [Knoxville, TN; Wintenberg, Alan L [Knoxville, TN; Clonts, Lloyd G [Knoxville, TN; Cooper, Ronald G [Oak Ridge, TN

    2010-09-21

    A preamplifier circuit for processing a signal provided by a radiation detector includes a transimpedance amplifier coupled to receive a current signal from a detector and generate a voltage signal at its output. A second amplification stage has an input coupled to an output of the transimpedance amplifier for providing an amplified voltage signal. Detector electronics include a preamplifier circuit having a first and second transimpedance amplifier coupled to receive a current signal from a first and second location on a detector, respectively, and generate a first and second voltage signal at respective outputs. A second amplification stage has an input coupled to an output of the transimpedance amplifiers for amplifying the first and said second voltage signals to provide first and second amplified voltage signals. A differential output stage is coupled to the second amplification stage for receiving the first and second amplified voltage signals and providing a pair of outputs from each of the first and second amplified voltage signals. Read out circuitry has an input coupled to receive both of the pair of outputs, the read out circuitry having structure for processing each of the pair of outputs, and providing a single digital output having a time-stamp therefrom.

  16. Methods for radiation detection and characterization using a multiple detector probe

    Science.gov (United States)

    Akers, Douglas William; Roybal, Lyle Gene

    2014-11-04

    Apparatuses, methods, and systems relating to radiological characterization of environments are disclosed. Multi-detector probes with a plurality of detectors in a common housing may be used to substantially concurrently detect a plurality of different radiation activities and types. Multiple multi-detector probes may be used in a down-hole environment to substantially concurrently detect radioactive activity and contents of a buried waste container. Software may process, analyze, and integrate the data from the different multi-detector probes and the different detector types therein to provide source location and integrated analysis as to the source types and activity in the measured environment. Further, the integrated data may be used to compensate for differential density effects and the effects of radiation shielding materials within the volume being measured.

  17. Summary Report for the Radiation Detection for Nuclear Security Summer School 2012

    Energy Technology Data Exchange (ETDEWEB)

    Runkle, Robert C.; Baciak, James E.; Stave, Jean A.

    2012-08-22

    The Pacific Northwest National Laboratory (PNNL) hosted students from across the United States at the inaugural Radiation Detection for Nuclear Security Summer School from June 11 – 22, 2012. The summer school provided students with a unique understanding of nuclear security challenges faced in the field and exposed them to the technical foundations, analyses, and insight that will be required by future leaders in technology development and implementation. The course heavily emphasized laboratory and field demonstrations including direct measurements of special nuclear material. The first week of the summer school focused on the foundational knowledge required by technology practitioners; the second week focused on contemporary applications. Student evaluations and feedback from student advisors indicates that the summer school achieved its objectives of 1) exposing students to the range of nuclear security applications for which radiation detection is necessary, 2) articulating the relevance of student research into the broader context, and 3) exciting students about the possibility of future careers in nuclear security.

  18. FISH as A method for detection of radiation Induced genetic damage

    International Nuclear Information System (INIS)

    Lakatosova, M.; Holeckova, B.

    2006-01-01

    Fluorescence in situ hybridization (FISH) has been considered as a suitable method for rapid and easy detection of chromosome aberrations. In contrast to the standard conventional staining procedure, this technique enables the detection and specification of stable chromosomal re-arrangements, which are compatible with cellular division and thus, they could be transmitted from common ancestral to next cell generations. FISH chromosome - specific painting probes have been effectively applied for the detection of chromosomal damage after exposure to radiation. During last years, several specific fluorescent labeled probes were performed that allowed precise detection of centromeres, sub-telomeres or other regions (sequences) in genome. Our paper deals with describing of different types of FISH probes and their possibilities for application in radiobiology. (authors)

  19. Possible standoff detection of ionizing radiation using high-power THz electromagnetic waves

    Science.gov (United States)

    Nusinovich, Gregory S.; Sprangle, Phillip; Romero-Talamas, Carlos A.; Rodgers, John; Pu, Ruifeng; Kashyn, Dmytro G.; Antonsen, Thomas M., Jr.; Granatstein, Victor L.

    2012-06-01

    Recently, a new method of remote detection of concealed radioactive materials was proposed. This method is based on focusing high-power short wavelength electromagnetic radiation in a small volume where the wave electric field exceeds the breakdown threshold. In the presence of free electrons caused by ionizing radiation, in this volume an avalanche discharge can then be initiated. When the wavelength is short enough, the probability of having even one free electron in this small volume in the absence of additional sources of ionization is low. Hence, a high breakdown rate will indicate that in the vicinity of this volume there are some materials causing ionization of air. To prove this concept a 0.67 THz gyrotron delivering 200-300 kW power in 10 microsecond pulses is under development. This method of standoff detection of concealed sources of ionizing radiation requires a wide range of studies, viz., evaluation of possible range, THz power and pulse duration, production of free electrons in air by gamma rays penetrating through container walls, statistical delay time in initiation of the breakdown in the case of low electron density, temporal evolution of plasma structure in the breakdown and scattering of THz radiation from small plasma objects. Most of these issues are discussed in the paper.

  20. Ionizing radiation-induced DNA injury and damage detection in patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Borrego-Soto, Gissela; Ortiz-Lopez, Rocio; Rojas-Martinez, Augusto, E-mail: arojasmtz@gmail.com, E-mail: augusto.rojasm@uanl.mx [Departamento de Bioquímica y Medicina Molecular, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León (Mexico)

    2015-10-15

    Breast cancer is the most common malignancy in women. Radiotherapy is frequently used in patients with breast cancer, but some patients may be more susceptible to ionizing radiation, and increased exposure to radiation sources may be associated to radiation adverse events. This susceptibility may be related to deficiencies in DNA repair mechanisms that are activated after cell-radiation, which causes DNA damage, particularly DNA double strand breaks. Some of these genetic susceptibilities in DNA-repair mechanisms are implicated in the etiology of hereditary breast/ovarian cancer (pathologic mutations in the BRCA 1 and 2 genes), but other less penetrant variants in genes involved in sporadic breast cancer have been described. These same genetic susceptibilities may be involved in negative radiotherapeutic outcomes. For these reasons, it is necessary to implement methods for detecting patients who are susceptible to radiotherapy-related adverse events. This review discusses mechanisms of DNA damage and repair, genes related to these functions, and the diagnosis methods designed and under research for detection of breast cancer patients with increased radiosensitivity. (author)

  1. Fast microwave detection system for coherent synchrotron radiation study at KEK: Accelerator test facility

    International Nuclear Information System (INIS)

    Aryshev, A.; Araki, S.; Karataev, P.; Naito, T.; Terunuma, N.; Urakawa, J.

    2007-01-01

    A fast room temperature microwave detection system based on the Schottky Barrier-diode detector was created at the KEK ATF (Accelerator Test Facility). It was tested using Coherent Synchrotron Radiation (CSR) generated by the 1.28 GeV electron beam in the damping ring. The speed performance of the detection system was checked by observing the CSR from a multi-bunch (2.8 ns bunch separation time) beam. The theoretical estimations of CSR power yield from an edge of bending magnet as well as new injection tuning method are presented. A very high sensitivity of CSR power yield to the longitudinal electron distribution in a bunch is discussed

  2. [Detection of endotoxins of Gram-negative bacteria on the basis of electromagnetic radiation frequency spectrum].

    Science.gov (United States)

    Likhoded, V G; Kuleshova, N V; Sergieva, N V; Konev, Iu V; Trubnikova, I A; Sudzhian, E V

    2007-01-01

    Method of Gram-negative bacteria endotoxins detection on the basis of their own spectrum of electromagnetic radiation frequency was developed. Frequency spectrum typical for chemotype Re glycolipid, which is a part of lypopolysaccharides in the majority of Gram-negative bacteria, was used. Two devices--"Mini- Expert-DT" (manufactured by IMEDIS, Moscow) and "Bicom" (manufactured by Regumed, Germany)--were used as generators of electromagnetic radiation. Detection of endotoxin using these devices was performed by electropuncture vegetative resonance test. Immunoenzyme reaction with antibodies to chemotype Re glycolipid was used during analysis of preparations for assessment of resonance-frequency method specificity. The study showed that resonance-frequency method can detect lypopolysaccharides of different enterobacteria in quantities up to 0.1 pg as well as bacteria which contain lypopolysaccharides. At the same time, this method does not detect such bacteria as Staphylococcus aureus, Bifidobacterium spp., Lactobacillus spp., and Candida albicans. The method does not require preliminary processing of blood samples and can be used for diagnostics of endotoxinemia, and detection of endotoxins in blood samples or injection solutions.

  3. Photostimulated luminescence detection and radiation effects on cinnamon (Cinnamomum zeylanicum) spice

    International Nuclear Information System (INIS)

    Marcazzó, J.; Sanchez-Barrera, C.E.; Urbina-Zavala, A.; Cruz-Zaragoza, E.

    2015-01-01

    The increase of disease borne pathogens in foods has promoted the use of new technologies in order to eliminate these pathogen microorganisms and extend the shelf-life of the foodstuffs. In particular, Cinnamon (Cinnamomum zeylanicum) contains an important number of pathogen microorganisms and it is frequently sterilized by gamma radiation. However, it is important to develop the detection methods for irradiated food in order to keep the dose control and also to analyze the radiation effects in their chemical property. This work reports (i) the photostimulated luminescence (PSL) detection of irradiated cinnamon and thermoluminescence (TL) detection of the inorganic polymineral fraction separated from this spice, and (ii) the proximate chemical analysis carried out on fat, protein and dietetic fiber contents. The detection limits using the PSL and TL methods were 500 Gy and 10 Gy, respectively, and the fat content was increased significantly with the gamma dose that could be related to the lipid oxidation in the cinnamon. - Highlights: • Samples of cinnamon (Cinnamomum zeylanicum) were studied by TL and PSL methods. • The cinnamon was detected as irradiated at a dose of 500 Gy using PSL. • TL method shows an excellent linear response for doses lesser than 500 Gy. • A proximate chemical analysis was carried out on fat, protein and dietetic fiber. • The TL and PSL responses can be used for dose control in commercial cinnamon

  4. Utilization of photoconductive gain in a-Si:H devices for radiation detection

    International Nuclear Information System (INIS)

    Lee, H.K.; Drewery, J.S.; Hong, W.S.; Jing, T.; Kaplan, S.N.; Perez-Mendez, V.

    1995-05-01

    The photoconductive gain mechanism in a-Si:H was investigated in connection with applications to radiation detection. Various device types such as p-i-n, n-i-n and n-i-p-i-n structures were fabricated and tested. Photoconductive gain was measured in two time scales: one for short pulses of visible light ( 2 . Various gain results are discussed in terms of the device structure, applied bias and dark current

  5. The EPR detection of foods preserved with the use of ionizing radiation

    Science.gov (United States)

    Stachowicz, W.; Burlińska, G.; Michalik, J.; Dziedzic-Gocławska, A.; Ostrowski, K.

    1995-02-01

    Solid constituents extracted from irradiated foods have been examined by the epr (esr) spectroscopy. It has been proved that some epr active species produced by radiation in foods are specific and stable enough to be used for the detection of irradiation treatment. The most promising results have been obtained with bones extracted from frozen raw meat (beef, pork, poultry and fish), with seeds of fruits (dates and figs), with dried mushrooms, gelatin and macaroni.

  6. EPR spectroscopy for the detection of foods treated with ionising radiation

    International Nuclear Information System (INIS)

    Stachowicz, W.; Burlinska, G.; Michalik, J.; Dziedzic-Goclawska, A.; Ostrowski, K.

    1996-01-01

    The advantage of electron paramagnetic resonance spectroscopy (EPR or ESR) as a tool for the control of irradiated food lies in its sensitivity and accuracy. Ionising radiation produces, in irradiated materials, paramagnetic species of different kinds, i.e. radicals, radical-ions and paramagnetic centres, which can be measured by EPR but most of them are not stable enough to be used for the detection of irradiation. It is because radiation-induced paramagnetic species are thermodynamically less stable than surrounding molecules and take part in fast radiolytic reactions leading to the formation of final diamagnetic products that they are not detectable by the EPR method. Most of organic radicals produced by radiation in the liquid phase ae unstable but if the unpaired electron is incorporated into the complex polymeric system as in peptides and polysaccharides and is structurally isolated from the water, its stability is markedly increased. Since 1954 it is known that ionising radiation produces paramagnetic entities in biological materials, cells and tissues and some are stable enough to be observed by EPR spectroscopy at room temperature. The present paper describes and discusses that part of results obtained by this group during the period of ADMIT activity (1989-94) which are original and may be useful to those who will be working in the near future on the development of uniform control systems for the detection of irradiated food. The intention was to focus attention on these facts and data which influence the certainty of the detection in both positive and negative manner. (author)

  7. Discrete Event Simulation Model of the Polaris 2.1 Gamma Ray Imaging Radiation Detection Device

    Science.gov (United States)

    2016-06-01

    release; distribution is unlimited DISCRETE EVENT SIMULATION MODEL OF THE POLARIS 2.1 GAMMA RAY IMAGING RADIATION DETECTION DEVICE by Andres T...ONLY (Leave blank) 2. REPORT DATE June 2016 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE DISCRETE EVENT SIMULATION MODEL...modeled. The platform, Simkit, was utilized to create a discrete event simulation (DES) model of the Polaris. After carefully constructing the DES

  8. Method of detection of transition radiation by wire chambers operating in self-quenching streamer mode

    International Nuclear Information System (INIS)

    Akopdzhanov, G.A.; Bityukov, S.I.; Dzhelyadin, R.I.; Zaitsev, A.M.; Lapin, V.V.; Saraikin, A.I.

    1984-01-01

    A method for detecting X-ray transition radiation against the background of the signal from relativistic charged particles is suggested that is based on the use of peculiarities of the development of self-queenching streamer mode. The self-qunching streamer discharge in the Xe + isobutane mixture is experimentally registered. The effect of separation of signals from the relativistic particle and from soft X-ray, is obtained

  9. New silicon photodiodes for detection of the 1064nm wavelength radiation

    Science.gov (United States)

    Wegrzecki, Maciej; Piotrowski, Tadeusz; Puzewicz, Zbigniew; Bar, Jan; Czarnota, Ryszard; Dobrowolski, Rafal; Klimov, Andrii; Kulawik, Jan; Kłos, Helena; Marchewka, Michał; Nieprzecki, Marek; Panas, Andrzej; Seredyński, Bartłomiej; Sierakowski, Andrzej; Słysz, Wojciech; Synkiewicz, Beata; Szmigiel, Dariusz; Zaborowski, Michał

    2016-12-01

    In this paper a concept of a new bulk structure of p+-υ-n+ silicon photodiodes optimized for the detection of fast-changing radiation at the 1064 nm wavelength is presented. The design and technology for two types of quadrant photodiodes, the 8-segment photodiode and the 32-element linear photodiode array that were developed according to the concept are described. Electric and photoelectric parameters of the photodiodes mentioned above are presented.

  10. Highly Sensitive Detection of UV Radiation Using a Uranium Coordination Polymer.

    Science.gov (United States)

    Liu, Wei; Dai, Xing; Xie, Jian; Silver, Mark A; Zhang, Duo; Wang, Yanlong; Cai, Yawen; Diwu, Juan; Wang, Jian; Zhou, Ruhong; Chai, Zhifang; Wang, Shuao

    2018-02-07

    The accurate detection of UV radiation is required in a wide range of chemical industries and environmental or biological related applications. Conventional methods taking advantage of semiconductor photodetectors suffer from several drawbacks such as sophisticated synthesis and manufacturing procedure, not being able to measure the accumulated UV dosage as well as high defect density in the material. Searching for new strategies or materials serving as precise UV dosage sensor with extremely low detection limit is still highly desirable. In this work, a radiation resistant uranium coordination polymer [UO 2 (L)(DMF)] (L = 5-nitroisophthalic acid, DMF = N,N-dimethylformamide, denoted as compound 1) was successfully synthesized through mild solvothermal method and investigated as a unique UV probe with the detection limit of 2.4 × 10 -7 J. On the basis of the UV dosage dependent luminescence spectra, EPR analysis, single crystal structure investigation, and the DFT calculation, the UV-induced radical quenching mechanism was confirmed. Importantly, the generated radicals are of significant stability which offers the opportunity for measuring the accumulated UV radiation dosage. Furthermore, the powder material of compound 1 was further upgraded into membrane material without loss in luminescence intensity to investigate the real application potentials. To the best of our knowledge, compound 1 represents the most sensitive coordination polymer based UV dosage probe reported to date.

  11. 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.

  12. 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.

  13. Radiation protection program for early detection of breast cancer in a mammography facility

    International Nuclear Information System (INIS)

    Mariana, Villagomez Casimiro; Cesar, Ruiz Trejo; Ruby, Espejo Fonseca

    2014-01-01

    Mammography is the best tool for early detection of Breast Cancer. In this diagnostic radiology modality it is necessary to establish the criteria to ensure the proper use and operation of the equipment used to obtain mammographic images in order to contribute to the safe use of ionizing radiation. The aim of the work was to implement at FUCAM-AC the radiation protection program which must be established for patients and radiation workers according to Mexican standards [1–4]. To achieve this goal, radiation protection and quality control manuals were elaborated [5]. Furthermore, a quality control program (QCP) in the mammography systems (analog/digital), darkroom included, has been implemented. Daily sensitometry, non-variability of the image quality, visualizing artifacts, revision of the equipment mechanical stability, compression force and analysis of repetition studies are some of the QCP routine tests that must be performed by radiological technicians of this institution as a set of actions to ensure the protection of patients. Image quality and patients dose assessment were performed on 4 analog equipment installed in 2 mobile units. In relation to dose assessment, all equipment passed the acceptance criteria (<3 mGy per projection). The image quality test showed that most images (70%)– presented artifacts. A brief summary of the results of quality control tests applied to the equipment and film processor are presented. To maintain an adequate level of quality and safety at FUCAM-AC is necessary that the proposed radiation protection program in this work is applied

  14. Radiation protection program for early detection of breast cancer in a mammography facility

    Energy Technology Data Exchange (ETDEWEB)

    Mariana, Villagomez Casimiro, E-mail: marjim10-66@ciencias.unam.mx, E-mail: cesar@fisica.unam.mx; Cesar, Ruiz Trejo, E-mail: marjim10-66@ciencias.unam.mx, E-mail: cesar@fisica.unam.mx [Instituto de Física, UNAM. Cd. Universitaria, CP 04510 (Mexico); Ruby, Espejo Fonseca [Instituto de Enfermedades de la Mama FUCAM-AC, CP 04980 (Mexico)

    2014-11-07

    Mammography is the best tool for early detection of Breast Cancer. In this diagnostic radiology modality it is necessary to establish the criteria to ensure the proper use and operation of the equipment used to obtain mammographic images in order to contribute to the safe use of ionizing radiation. The aim of the work was to implement at FUCAM-AC the radiation protection program which must be established for patients and radiation workers according to Mexican standards [1–4]. To achieve this goal, radiation protection and quality control manuals were elaborated [5]. Furthermore, a quality control program (QCP) in the mammography systems (analog/digital), darkroom included, has been implemented. Daily sensitometry, non-variability of the image quality, visualizing artifacts, revision of the equipment mechanical stability, compression force and analysis of repetition studies are some of the QCP routine tests that must be performed by radiological technicians of this institution as a set of actions to ensure the protection of patients. Image quality and patients dose assessment were performed on 4 analog equipment installed in 2 mobile units. In relation to dose assessment, all equipment passed the acceptance criteria (<3 mGy per projection). The image quality test showed that most images (70%)– presented artifacts. A brief summary of the results of quality control tests applied to the equipment and film processor are presented. To maintain an adequate level of quality and safety at FUCAM-AC is necessary that the proposed radiation protection program in this work is applied.

  15. Radiation protection program for early detection of breast cancer in a mammography facility

    Science.gov (United States)

    Villagomez Casimiro, Mariana; Ruiz Trejo, Cesar; Espejo Fonseca, Ruby

    2014-11-01

    Mammography is the best tool for early detection of Breast Cancer. In this diagnostic radiology modality it is necessary to establish the criteria to ensure the proper use and operation of the equipment used to obtain mammographic images in order to contribute to the safe use of ionizing radiation. The aim of the work was to implement at FUCAM-AC the radiation protection program which must be established for patients and radiation workers according to Mexican standards [1-4]. To achieve this goal, radiation protection and quality control manuals were elaborated [5]. Furthermore, a quality control program (QCP) in the mammography systems (analog/digital), darkroom included, has been implemented. Daily sensitometry, non-variability of the image quality, visualizing artifacts, revision of the equipment mechanical stability, compression force and analysis of repetition studies are some of the QCP routine tests that must be performed by radiological technicians of this institution as a set of actions to ensure the protection of patients. Image quality and patients dose assessment were performed on 4 analog equipment installed in 2 mobile units. In relation to dose assessment, all equipment passed the acceptance criteria (radiation protection program in this work is applied.

  16. Radiation

    International Nuclear Information System (INIS)

    2013-01-01

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  17. Radiation-related caries assessment through the International Caries Detection and Assessment System and the Post-Radiation Dental Index.

    Science.gov (United States)

    Palmier, Natalia Rangel; Ribeiro, Ana Carolina Prado; Fonsêca, Jéssica Montenegro; Salvajoli, João Victor; Vargas, Pablo Agustin; Lopes, Marcio Ajudarte; Brandão, Thaís Bianca; Santos-Silva, Alan Roger

    2017-12-01

    Although radiation-related caries (RRC) are a well-known toxicity of head and neck radiotherapy, a clinical classification system for RRC has not yet been clinically validated. Therefore, the aim of this study was to assess whether the International Caries Detection and Assessment System (ICDAS) and the Post-Radiation Dental Index (PRDI) were viable methods for the assessment of RRC. Clinicopathologic data and intraoral digital photographs of 60 patients (833 teeth) affected by RRC were assessed and classified according to the ICDAS and PRDI criteria. A total of 814 (97.7%) teeth presented RRC lesions ranging from early stage to complete tooth destruction. Mean scores for the whole sample were 5 for ICDAS and 3 for PRDI, indicating that RRC were diagnosed predominately in late stages. ICDAS and PRDI criteria underestimate the clinical expressivity of RRC by not including the whole qualitative clinical spectrum of RRC, such as enamel cracks, delamination, dental crown amputation, surface color alterations, and atypical lesions topography (incisal/cuspal caries). ICDAS and PRDI may not be considered viable for the assessment of RRC. The development of a specific clinical classification system is urgently needed to help clinicians recognize the peculiar patterns of RRC, particularly in incipient cases. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Fluorescence in situ hybridisation in chromosome aberration detection in subjects occupationally exposed to ionising radiation

    International Nuclear Information System (INIS)

    Zeljezic, D.; Garaj-Vrhovac, V.

    2005-01-01

    For more than two decades, chromosomal aberration analysis has been used to detect structural chromosomal aberrations as sensitive biodosimeters of occupational exposure to ionising radiation. Its use is also recommended by the World Health Organisation. Changes in chromosome structure detected by that method are considered to be early biomarkers of a possible malignant disease. Aberrations detected by the method are unstable and can be found in the lymphocytes of irradiated personnel only within a limited time after exposure. To detect stable chromosomal aberrations, which persist after exposure, multicolour fluorescent in situ hybridisation has to be used. Using DNA probes labelled with different fluorochromes, it dyes each pair of chromosomes with different colour. Due to the dynamic of unstable aberration formation, chromosomal aberration analysis is more suitable in genome damage assessment of recent exposures. On the other hand, fluorescence in situ hybridisation gives the information on chromosome instability caused by long-term occupational exposure to ionising radiation. Considering the high costs of fluorescence in situ hybridisation and the uncertainty of the result, it should be used in biodosimetry only when it is absolutely necessary.(author)

  19. Role of electroweak radiation in predictions for dark matter indirect detection

    Energy Technology Data Exchange (ETDEWEB)

    Ali Cavasonza, Leila; Pellen, Mathieu; Kraemer, Michael [RWTH Aachen, Aachen (Germany)

    2015-07-01

    A very exciting challenge in particle and astroparticle physics is the exploration of the nature of dark matter. The evidences of the existence of dark matter are also the strongest phenomenological indications for physics beyond the Standard Model. A huge experimental effort is currently made at colliders and via astrophysical experiments to shed light on the nature of dark matter: dark matter may be produced at colliders or detected through direct and indirect detection experiments. The interplay and complementarity between these different approaches offers extraordinary opportunities to improve our understanding of the nature of dark matter or to set constraints on dark matter models. In indirect detection one searches for dark matter annihilation products, that produce secondary antimatter particles like positrons and antiprotons. Such antimatter particles propagate through the Galaxy and can be detected at Earth by astrophysical experiments. Particularly interesting is the importance of electroweak corrections to the predictions for the expected fluxes at Earth. The inclusion of EW radiation from the primary dark matter annihilation products can significantly affect the spectra of the secondary SM particles. The EW radiation can be described using fragmentation functions, as done for instance in QCD. We study the quality of this approximation in a simplified SUSY model and in a UED model.

  20. System for visualizing a body by detecting the radiation of a tracer contained therein

    International Nuclear Information System (INIS)

    Vacher, Jacques.

    1980-01-01

    This invention concerns a device for visualizing a body by detecting the radiation from a tracer composed of positron emitters contained in this body. This system has a particular application in tomography and hence for the visualization of a group of organs in a given cross-section. It includes: - detection cells positioned on both sides of the body to detect the gamma particles delivered by each positron emitter, in two opposite directions, - devices for localizing cells opposed in pairs, on both sides of the body, each opposed pair of cells being located on a straight line passing through a positron emitter, - systems for coding the localization of these pairs of opposed cells, - systems for memorizing these coded localization signals, - facilities for processing these stored signals, - visual displays controlled by the data processing units, to show the image of the body as from the various coded and memorized signals [fr

  1. Feasibility of OCT to detect radiation-induced esophageal damage in small animal models (Conference Presentation)

    Science.gov (United States)

    Jelvehgaran, Pouya; Alderliesten, Tanja; Salguero, Javier; Borst, Gerben; Song, Ji-Ying; van Leeuwen, Ton G.; de Boer, Johannes F.; de Bruin, Daniel M.; van Herk, Marcel B.

    2016-03-01

    Lung cancer survival is poor and radiotherapy patients often suffer serious treatment side effects. The esophagus is particularly sensitive leading to reduced food intake or even fistula formation. Only few direct techniques exist to measure radiation-induced esophageal damage, for which knowledge is needed to improve the balance between risk of tumor recurrence and complications. Optical coherence tomography (OCT) is a minimally-invasive imaging technique that obtains cross-sectional, high-resolution (1-10µm) images and is capable of scanning the esophageal wall up to 2-3mm depth. In this study we investigated the feasibility of OCT to detect esophageal radiation damage in mice. In total 30 mice were included in 4 study groups (1 main and 3 control groups). Mice underwent cone-beam CT imaging for initial setup assessment and dose planning followed by single-fraction dose delivery of 4, 10, 16, and 20Gy on 5mm spots, spaced 10mm apart. Mice were repeatedly imaged using OCT: pre-irradiation and up to 3 months post-irradiation. The control groups received either OCT only, irradiation only, or were sham-operated. We used histopathology as gold standard for radiation-induced damage diagnosis. The study showed edema in both the main and OCT-only groups. Furthermore, radiation-induced damage was primarily found in the highest dose region (distal esophagus). Based on the histopathology reports we were able to identify the radiation-induced damage in the OCT images as a change in tissue scattering related to the type of induced damage. This finding indicates the feasibility and thereby the potentially promising role of OCT in radiation-induced esophageal damage assessment.

  2. Spherical transceivers for ultrafast optical wireless communications

    Science.gov (United States)

    Jin, Xian; Hristovski, Blago A.; Collier, Christopher M.; Geoffroy-Gagnon, Simon; Born, Brandon; Holzman, Jonathan F.

    2016-02-01

    Optical wireless communications (OWC) offers the potential for high-speed and mobile operation in indoor networks. Such OWC systems often employ a fixed transmitter grid and mobile transceivers, with the mobile transceivers carrying out bi-directional communication via active downlinks (ideally with high-speed signal detection) and passive uplinks (ideally with broad angular retroreflection and high-speed modulation). It can be challenging to integrate all of these bidirectional communication capabilities within the mobile transceivers, however, as there is a simultaneous desire for compact packaging. With this in mind, the work presented here introduces a new form of transceiver for bi-directional OWC systems. The transceiver incorporates radial photoconductive switches (for high-speed signal detection) and a spherical retro-modulator (for broad angular retroreflection and high-speed all-optical modulation). All-optical retromodulation are investigated by way of theoretical models and experimental testing, for spherical retro-modulators comprised of three glasses, N-BK7, N-LASF9, and S-LAH79, having differing levels of refraction and nonlinearity. It is found that the spherical retro-modulator comprised of S-LAH79, with a refractive index of n ≍ 2 and a Kerr nonlinear index of n2 ≍ (1.8 ± 0.1) × 10-15 cm2/W, yields both broad angular retroreflection (over a solid angle of 2π steradians) and ultrafast modulation (over a duration of 120 fs). Such transceivers can become important elements for all-optical implementations in future bi-directional OWC systems.

  3. Ultrafast dynamics of correlated electrons

    International Nuclear Information System (INIS)

    Rettig, Laurenz

    2012-01-01

    This work investigates the ultrafast electron dynamics in correlated, low-dimensional model systems using femtosecond time- and angle-resolved photoemission spectroscopy (trARPES) directly in the time domain. In such materials, the strong electron-electron (e-e) correlations or coupling to other degrees of freedom such as phonons within the complex many-body quantum system lead to new, emergent properties that are characterized by phase transitions into broken-symmetry ground states such as magnetic, superconducting or charge density wave (CDW) phases. The dynamical processes related to order like transient phase changes, collective excitations or the energy relaxation within the system allow deeper insight into the complex physics governing the emergence of the broken-symmetry state. In this work, several model systems for broken-symmetry ground states and for the dynamical charge balance at interfaces have been studied. In the quantum well state (QWS) model system Pb/Si(111), the charge transfer across the Pb/Si interface leads to an ultrafast energetic stabilization of occupied QWSs, which is the result of an increase of the electronic confinement to the metal film. In addition, a coherently excited surface phonon mode is observed. In antiferromagnetic (AFM) Fe pnictide compounds, a strong momentum-dependent asymmetry of electron and hole relaxation rates allows to separate the recovery dynamics of the AFM phase from electron-phonon (e-ph) relaxation. The strong modulation of the chemical potential by coherent phonon modes demonstrates the importance of e-ph coupling in these materials. However, the average e-ph coupling constant is found to be small. The investigation of the excited quasiparticle (QP) relaxation dynamics in the high-T c 4 superconductor Bi 2 Sr 2 CaCu 2 O 8+δ reveals a striking momentum and fluence independence of the QP life times. In combination with the momentum-dependent density of excited QPs, this demonstrates the suppression of momentum

  4. Ultrafast dynamics of correlated electrons

    Energy Technology Data Exchange (ETDEWEB)

    Rettig, Laurenz

    2012-07-09

    This work investigates the ultrafast electron dynamics in correlated, low-dimensional model systems using femtosecond time- and angle-resolved photoemission spectroscopy (trARPES) directly in the time domain. In such materials, the strong electron-electron (e-e) correlations or coupling to other degrees of freedom such as phonons within the complex many-body quantum system lead to new, emergent properties that are characterized by phase transitions into broken-symmetry ground states such as magnetic, superconducting or charge density wave (CDW) phases. The dynamical processes related to order like transient phase changes, collective excitations or the energy relaxation within the system allow deeper insight into the complex physics governing the emergence of the broken-symmetry state. In this work, several model systems for broken-symmetry ground states and for the dynamical charge balance at interfaces have been studied. In the quantum well state (QWS) model system Pb/Si(111), the charge transfer across the Pb/Si interface leads to an ultrafast energetic stabilization of occupied QWSs, which is the result of an increase of the electronic confinement to the metal film. In addition, a coherently excited surface phonon mode is observed. In antiferromagnetic (AFM) Fe pnictide compounds, a strong momentum-dependent asymmetry of electron and hole relaxation rates allows to separate the recovery dynamics of the AFM phase from electron-phonon (e-ph) relaxation. The strong modulation of the chemical potential by coherent phonon modes demonstrates the importance of e-ph coupling in these materials. However, the average e-ph coupling constant is found to be small. The investigation of the excited quasiparticle (QP) relaxation dynamics in the high-T{sub c}4 superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ} reveals a striking momentum and fluence independence of the QP life times. In combination with the momentum-dependent density of excited QPs, this demonstrates the

  5. Ultrafast laser spectroscopy in complex solid state materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tianqi [Iowa State Univ., Ames, IA (United States)

    2014-12-01

    This thesis summarizes my work on applying the ultrafast laser spectroscopy to the complex solid state materials. It shows that the ultrafast laser pulse can coherently control the material properties in the femtosecond time scale. And the ultrafast laser spectroscopy can be employed as a dynamical method for revealing the fundamental physical problems in the complex material systems.

  6. Development of a homogeneous pulse shape discriminating flow-cell radiation detection system

    International Nuclear Information System (INIS)

    Hastie, K.H.; DeVol, T.A.; Fjeld, R.A.

    1999-01-01

    A homogeneous flow-cell radiation detection system which utilizes coincidence counting and pulse shape discrimination circuitry was assembled and tested with five commercially available liquid scintillation cocktails. Two of the cocktails, Ultima Flo (Packard) and Mono Flow 5 (National Diagnostics) have low viscosities and are intended for flow applications; and three of the cocktails, Optiphase HiSafe 3 (Wallac), Ultima Gold AB (Packard), and Ready Safe (Beckman), have higher viscosities and are intended for static applications. The low viscosity cocktails were modified with 1-methylnaphthalene to increase their capability for alpha/beta pulse shape discrimination. The sample loading and pulse shape discriminator setting were optimized to give the lowest minimum detectable concentration for methylnaphthalenein a 30 s count time. Of the higher viscosity cocktails, Optiphase HiSafe 3 had the lowest minimum detectable activities for alpha and beta radiation, 0.2 and 0.4 Bq/ml for 233 U and 90 Sr/ 90 Y, respectively, for a 30 s count time. The sample loading was 70% and the corresponding alpha/beta spillover was 5.5%. Of the low viscosity cocktails, Mono Flow 5 modified with 2.5% (by volume) 1-methylnaphthalene resulted in the lowest minimum detectable activities for alpha and beta radiation; 0.3 and 0.5 Bq/ml for 233 U and 90 Sr/ 90 Y, respectively, for a 30 s count time. The sample loading was 50%, and the corresponding alpha/beta spillover was 16.6%. HiSafe 3 at a 10% sample loading was used to evaluate the system under simulated flow conditions

  7. Detection of dark-matter-radiation of stars during visible sun eclipses

    International Nuclear Information System (INIS)

    Volkamer, Klaus

    2003-01-01

    Recently a so-far unknown form of quantized, cold dark matter was detected on a laboratory scale which shows a complementary structure as compared to known forms of matter. From the experiments results that the observed quanta of the new type of matter as integer multiples of the Planck mass (mp = n · √((h·c)/((2 · π · G))) = n 0 21.77 μg, with n = 1, 2, 3 etc.) exhibit a spatially extended 'field-like' structure ranging over distances of centimetres or more, opposite to the 'point-like' structure of the known elementary particles of the standard model. Association of quanta of the new form of 'soft' (or subtle) matter to clusters was observed, as well as re-clustering after absorption. Thus, between such quanta a physical interaction must exist. In addition, the new form of matter shows at least two interactions with normal matter, a gravitational one due to its real mass content and a so-far unknown 'topological', i.e. form-specific, interaction at phase borders. Additional indications for a weak electromagnetic interaction exist. Furthermore, the experimental results reveal that some types of quanta of the new form of 'field-like' matter exhibit positive mass, as normal matter, but others exhibit a negative mass content, both in the order of magnitude of the Planck mass. Memory effects in normal matter were detected after absorption of quanta of the new form of soft matter. In general, the findings characterize the quanta of 'fieldlike' matter as WIMP candidates of a cosmic background radiation of cold dark matter (quanta with positive mass) as well as of a cosmic background radiation of dark energy (quanta with negative mass). During visible sun eclipses in 1989, 1996 and. 1999, as well as during full moon of 6 January 2001, a so-far unknown form of dark-matter-radiation ('dark radiation') was detected. The quanta of this 'dark radiation' travel with the speed of light, but reveal macroscopic real mass, with positive and with negative mass content. The

  8. Bayesian-statistical decision threshold, detection limit, and confidence interval in nuclear radiation measurement

    International Nuclear Information System (INIS)

    Weise, K.

    1998-01-01

    When a contribution of a particular nuclear radiation is to be detected, for instance, a spectral line of interest for some purpose of radiation protection, and quantities and their uncertainties must be taken into account which, such as influence quantities, cannot be determined by repeated measurements or by counting nuclear radiation events, then conventional statistics of event frequencies is not sufficient for defining the decision threshold, the detection limit, and the limits of a confidence interval. These characteristic limits are therefore redefined on the basis of Bayesian statistics for a wider applicability and in such a way that the usual practice remains as far as possible unaffected. The principle of maximum entropy is applied to establish probability distributions from available information. Quantiles of these distributions are used for defining the characteristic limits. But such a distribution must not be interpreted as a distribution of event frequencies such as the Poisson distribution. It rather expresses the actual state of incomplete knowledge of a physical quantity. The different definitions and interpretations and their quantitative consequences are presented and discussed with two examples. The new approach provides a theoretical basis for the DIN 25482-10 standard presently in preparation for general applications of the characteristic limits. (orig.) [de

  9. 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.

  10. How Can Synchrotron Radiation Techniques Be Applied for Detecting Microstructures in Amorphous Alloys?

    Directory of Open Access Journals (Sweden)

    Gu-Qing Guo

    2015-11-01

    Full Text Available In this work, how synchrotron radiation techniques can be applied for detecting the microstructure in metallic glass (MG is studied. The unit cells are the basic structural units in crystals, though it has been suggested that the co-existence of various clusters may be the universal structural feature in MG. Therefore, it is a challenge to detect microstructures of MG even at the short-range scale by directly using synchrotron radiation techniques, such as X-ray diffraction and X-ray absorption methods. Here, a feasible scheme is developed where some state-of-the-art synchrotron radiation-based experiments can be combined with simulations to investigate the microstructure in MG. By studying a typical MG composition (Zr70Pd30, it is found that various clusters do co-exist in its microstructure, and icosahedral-like clusters are the popular structural units. This is the structural origin where there is precipitation of an icosahedral quasicrystalline phase prior to phase transformation from glass to crystal when heating Zr70Pd30 MG.

  11. Sensor and method for measurment of select components of a material based on detection of radiation after interaction with the material

    International Nuclear Information System (INIS)

    Chase, L.M.; Anderson, L.M.; Norton, M.K.

    1993-01-01

    A sensor is described for measuring one or more select components of a sheet, comprising: a radiation source for emitting radiation toward the sheet; a plurality of detecting means, wherein at least one detecting means is offset from the source, for detecting radiation after interaction with the sheet; means for directing the radiation so that the radiation makes multiple interactions with the sheet in moving from the source to the detecting means, wherein the directing means includes a first reflector and second reflector defining a sheet space for the sheet to occupy; means for computing a ratio of the intensity of the detected radiation when the sheet is absent from the sheet space and the intensity of the detected radiation when the sheet occupies the sheet space; and means for computing the absorption power of the sheet from the intensity of the detected radiation

  12. Detection of the Level of Reactive Oxygen Species Induced by Ionizing Radiation in Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Chung, Dong Min; Kim, Jin-Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    By definition, the direct effect is referred to interaction between photon and DNA molecule, whereas the indirect effect is mediated by the reactive oxygen species (ROS) generated by radiolysis and subsequent reaction. It has been reported that ROS produced after exposure to IR can react with cellular materials such as DNA, proteins, carbohydrates and lipids. ROS is free radicals such as the superoxide anion, hydroxyl radicals and the non-radical hydrogen peroxide. Cells generate ROS during aerobic metabolism. Excessive production of ROS can lead to oxidative stress, genetic alteration and even cell death. It has been reported that ROS plays a critical role in radiation-induced cell injury. Thus, it is of great interest to determine the radiation-induced ROS level. Many kinds of methods to detect the level of ROS have been developed so far. There were random changes of fluorescence intensity in the treatment after irradiation. This result meant that this protocol was not appropriate for determination of radiation-induced ROS. On the other hand, the fluorescence intensity was increased in a dose-dependent manner when the cells were treated with the DCFH-DA solution before irradiation. Conclusions can be drawn from the experimental results of this study. In order to properly measure the ROS level in the cells exposed to ionizing radiation, the cells should be treated with the DCFH-DA solution before irradiation.

  13. Ultrasound-Detected Thyroid Nodule Prevalence and Radiation Dose from Fallout

    Science.gov (United States)

    Land, C. E.; Zhumadilov, Z.; Gusev, B. I.; Hartshorne, M. H.; Wiest, P. W.; Woodward, P. W.; Crooks, L. A.; Luckyanov, N. K.; Fillmore, C. M.; Carr, Z.; Abisheva, G.; Beck, H. L.; Bouville, A.; Langer, J.; Weinstock, R.; Gordeev, K. I.; Shinkarev, S.; Simon, S. L.

    2014-01-01

    Settlements near the Semipalatinsk Test Site (SNTS) in northeastern Kazakhstan were exposed to radioactive fallout during 1949–1962. Thyroid disease prevalence among 2994 residents of eight villages was ascertained by ultrasound screening. Malignancy was determined by cytopathology. Individual thyroid doses from external and internal radiation sources were reconstructed from fallout deposition patterns, residential histories and diet, including childhood milk consumption. Point estimates of individual external and internal dose averaged 0.04 Gy (range 0–0.65) and 0.31 Gy (0–9.6), respectively, with a Pearson correlation coefficient of 0.46. Ultrasound-detected thyroid nodule prevalence was 18% and 39% among males and females, respectively. It was significantly and independently associated with both external and internal dose, the main study finding. The estimated relative biological effectiveness of internal compared to external radiation dose was 0.33, with 95% confidence bounds of 0.09–3.11. Prevalence of papillary cancer was 0.9% and was not significantly associated with radiation dose. In terms of excess relative risk per unit dose, our dose–response findings for nodule prevalence are comparable to those from populations exposed to medical X rays and to acute radiation from the Hiroshima and Nagasaki atomic bombings. PMID:18363427

  14. Time Resolved Detection of Infrared Synchrotron Radiation at DAΦNE

    International Nuclear Information System (INIS)

    Bocci, A.; Marcelli, A.; Drago, A.; Guidi, M. Cestelli; Pace, E.; Piccinini, M.; Sali, D.; Morini, P.; Piotrowski, J.

    2007-01-01

    Synchrotron radiation is characterized by a very wide spectral emission from IR to X-ray wavelengths and a pulsed structure that is a function of the source time structure. In a storage ring, the typical temporal distance between two bunches, whose duration is a few hundreds of picoseconds, is on the nanosecond scale. Therefore, synchrotron radiation sources are a very powerful tools to perform time-resolved experiments that however need extremely fast detectors. Uncooled IR devices optimized for the mid-IR range with sub-nanosecond response time, are now available and can be used for fast detection of intense IR sources such as synchrotron radiation storage rings. We present here different measurements of the pulsed synchrotron radiation emission at DAΦNE (Double Annular Φ-factory for Nice Experiments), the collider of the Laboratori Nazionali of Frascati (LNF) of the Istituto Nazionale di Fisica Nucleare (INFN), performed with very fast uncooled infrared detectors with a time resolution of a few hundreds of picoseconds. We resolved the emission time structure of the electron bunches of the DAΦNE collider when it works in a normal condition for high energy physics experiments with both photovoltaic and photoconductive detectors. Such a technology should pave the way to new diagnostic methods in storage rings, monitoring also source instabilities and bunch dynamics

  15. Radiation monitors of new generation - New methodology of detection of nuclear and radioactive materials

    International Nuclear Information System (INIS)

    Kagan, L.; Stavrov, A.

    2001-01-01

    Full text: In recent few years the world community has faced a problem which was considered before as an almost theoretical one - a possibility of illicit trafficking of nuclear and radioactive materials due to their partially controlled or even completely uncontrolled proliferation. Organization of the first conference entitled 'Safety of Radiation Sources and Security of Radioactive Materials', Dijon, France, 14-18 September 1998, is particularly a witness of the world community's concern about these issues. The conference was held under the aegis of the IAEA, European Commission, INTERPOL and World Customs Organization. The conference covered the whole range of problems concerned with both the elaboration of legal regulations of radiation control, development of equipment and training of personnel. Since 1997 till 2000 the international ITRAP program (Illicit Trafficking Radiation Detection Assessment Program) was held under the aegis of the IAEA, WCO and INTERPOL. The task of the program was to work out the common requirements to the equipment, to test the equipment against the program requirements and to elaborate recommendations for the IAEA member-countries. In the course of this program realization the modern devices of the world leading manufacturers of the equipment for radiation control at state borders had been tested. The equipment to be tested is designed to fulfil the following main tasks: alarming about the presence of radioactive source in the controlled area; detection and location of the source, as well as its identification, personnel radiation protection being necessarily provided. To fulfil each of the above tasks essentially different specialized instruments are used: from large fixed installed systems to portable instruments, 'pager' type pocket search instruments and personal dosimeters. Consequently numerous different instruments have to be used during the radiation control at borders. It creates considerable difficulties for border guard

  16. Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes

    Science.gov (United States)

    Zhai, Zhao-Hui; Zhong, Sen-Cheng; Li, Jun; Zhu, Li-Guo; Meng, Kun; Li, Jiang; Liu, Qiao; Peng, Qi-Xian; Li, Ze-Ren; Zhao, Jian-Heng

    2016-09-01

    Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study of irreversible or single shot ultrafast events requires ability to record transient properties at multiple time delays, i.e., time resolved at single shot level, which is not available currently. Here by angular multiplexing use of femtosecond laser pulses, we developed and demonstrated a time resolved, transient terahertz time domain spectroscopy technique, where burst mode THz pulses were generated and then detected in a single shot measurement manner. The burst mode THz pulses contain 2 sub-THz pulses, and the time gap between them is adjustable up to 1 ns with picosecond accuracy, thus it can be used to probe the single shot event at two different time delays. The system can detect the sub-THz pulses at 0.1 THz-2.5 THz range with signal to noise ratio (SNR) of ˜400 and spectrum resolution of 0.05 THz. System design was described here, and optimizations of single shot measurement of THz pulses were discussed in detail. Methods to improve SNR were also discussed in detail. A system application was demonstrated where pulsed THz signals at different time delays of the ultrafast process were successfully acquired within single shot measurement. This time resolved transient terahertz time domain spectroscopy technique provides a new diagnostic tool for irreversible or single shot ultrafast events where dynamic information can be extracted at terahertz range within one-shot experiment.

  17. Embedded Detection and Correction of SEU Bursts in SRAM Memories Used as Radiation Detectors

    CERN Document Server

    Secondo, R.; Danzeca, S.; Losito, R.; Peronnard, P.; Masi, A.; Brugger, M.; Dusseau, L.

    2016-01-01

    SRAM memories are widely used as particle fluence detectors in high radiation environments, such as in the Radiation Monitoring System (RadMon) currently in operation in the CERN accelerator complex. Multiple Cell Upsets (MCUs), arising from micro-latchup events, are characterized by a large number of SEUs, ultimately affecting the measurement of particle fluxes and resulting in corrupted data and accuracy losses. A study of the generation of this type of SEU bursts was performed on an 8 Mbit 90-nm SRAM memory. Experimental tests were carried out with a focused beam of protons on target as well as in a mixed field environment dominated by high energy hadrons. A solution approach using an on-line detection and correction algorithm embedded on an FPGA was investigated and evaluated for use on a RadMon device.

  18. Radiation Detection and Dual-Energy X-Ray Imaging for Port Security

    Energy Technology Data Exchange (ETDEWEB)

    Pashby, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glenn, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Divin, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martz, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-08-09

    Millions of cargo containers are transported across the United States border annually and are inspected for illicit radioactive material and contraband using a combination of passive radiation portal monitors (RPM) and high energy X-ray non-intrusive inspection (NII) systems. As detection performance is expected to vary with the material composition of cargo, characterizing the types of material present in cargo is important to national security. This work analyzes the passive radiation and dual energy radiography signatures from on RPM and two NII system, respectively. First, the cargos were analyzed to determine their ability to attenuate emissions from an embedded radioactive source. Secondly, dual-energy X-ray discrimination was used to determine the material composition and density of the cargos.

  19. Microfabricated electrochemical sensor for the detection of radiation-induced DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.; Rivas, G.; Ozsoz, M.; Grant, D.H.; Cai, X.; Parrado, C. [New Mexico State Univ., Las Cruces, NM (United States)

    1997-04-01

    An electrochemical biosensor protocol for the detection of radiation-induced DNA damage is described. The procedure employs a dsDNA-coated screen-printed electrode and relies on changes in the guanine-DNA oxidation signal upon exposure to ultraviolet radiation. The decreased signal is ascribed primarily to conformational changes in the DNA and to the photoconversion of the guanine-DNA moiety to a nonelectroactive monomeric base product. Factors influencing the response of these microfabricated DNA sensors, such as irradiation time, wavelength, and distance, are explored, and future prospects are discussed. Similar results are given for the use of bare strip electrodes in connection with irradiated DNA solutions. 8 refs., 4 figs.

  20. Study and characterization of III-V semiconductor materials for applications in ionizing radiation detection

    International Nuclear Information System (INIS)

    Moulin, H.

    1989-11-01

    The photoconduction in the bulk of the gallium arsenide (GaAs) and of the indium phosphide doped with iron (InP:Fe) is investigated. These semiconductor materials are to be applied in X rays detection. The photoconduction theory and the physical characteristics of those materials are reviewed. The computer simulation models for studying the photoconductor responses to the radiation pulses are described. The experimental results are discussed. They include the following aspects: the characterization of the GaAs and InP:Fe, in the obscurity, as a function of the polarized electric field and of the neutrons dose; the characterization under X ray. Continuous X rays and pulsed synchrotron radiation are applied [fr

  1. Measuring element for detection and dose measurement of gamma radiation and neutrons and manufacturing method for the measuring element

    International Nuclear Information System (INIS)

    Piesch, E.; John, W.

    1979-01-01

    The measuring element consists of a bubble-free glass composed on the basis of metaphosphate material. The detection of the γ-radiation takes place through the photoluminescence of the element, and detection of the neutrons by means of resulting β particles producing Cerenkov radiation in the radioluminescence material, that can be measured. For this purpose in addition to Ag the glass contains As as a second excitable element. (DG) [de

  2. Sensitivity of radiation monitoring systems in Manila Ports in detecting contamination in foodstuff shipments

    International Nuclear Information System (INIS)

    Romallosa, Kristine Marie D.; Caseria, Estrella S.; Piquero, Ronald E.; Agustin, Jan Aldrich A.

    2011-01-01

    During the Fukushima Nuclear Power Plant accident in Japan, one of the Philippines' measures to protect the public from radiological hazards of the accident is by monitoring agricultural and food imports for radioactive contamination. In this study, the sensitivity of the mobile Radiation Monitoring System (RM) in Manila Ports in detecting contamination in incoming foodstuff shipments was determined. Large volume synthetic 137 Cs reference sources were used to determine the minimum detectable concentration (MDC) of the RMS. The reference sources have radioactivity concentrations that are comparable to the PNRI guidance level of 1000 Bg/kg for 137 Cs that is destined for general consumption. Results of the MDC measurements show that the RMS units are sensitive enough to detect radioactivity levels that are within the guidance levels provided that a) the minimum package lot is approximately 200 kg, b) the package is positioned at the detector side, and c) the alarm setting of RMS is as calibrated. It was therefore established that the RMS can be used to initially screen incoming foodstuff shipments of possible contamination and thereby help minimize potential radiation exposures to the public. (author)

  3. The signature-based radiation-scanning approach to standoff detection of improvised explosive devices

    International Nuclear Information System (INIS)

    Brewer, R.L.; Dunn, W.L.; Heider, S.; Matthew, C.; Yang, X.

    2012-01-01

    The signature-based radiation-scanning technique for detection of improvised explosive devices is described. The technique seeks to detect nitrogen-rich chemical explosives present in a target. The technology compares a set of “signatures” obtained from a test target to a collection of “templates”, sets of signatures for a target that contain an explosive in a specific configuration. Interrogation of nitrogen-rich fertilizer samples, which serve as surrogates for explosives, is shown experimentally to be able to discriminate samples of 3.8 L and larger. - Highlights: ► Signature-based radiation-scanning techniques applied to detection of explosives. ► Nitrogen-rich fertilizer samples served as surrogate explosive samples. ► Signatures of a target compared to collections of templates of surrogate explosives. ► Figure-of-merit determined for neutron and neutron-induced gamma-ray signatures. ► Discrimination of surrogate explosive from inert samples of 3.8 L and larger.

  4. Multi-channel Waveform Sampling ASIC for radiation detection and measurement

    International Nuclear Information System (INIS)

    Shimazoe, K.; Takahashi, H.; Yeom, J.Y.; Furumiya, T.; Ohi, J.

    2013-01-01

    We have designed and fabricated a 16-channel Waveform Sampling ASIC for radiation detection and measurement. Waveform sampling is very important for the pulse shape analysis and discrimination, which is often used in radiation detection to discriminate different radiations such as alpha, beta and gamma rays. One channel of the fabricated ASIC consists of a charge-sensitive preamplifier, a VGA (Variable Gain Amplifier), an ADC (Analog to Digital Converter) and digital circuits. The preamplifier converts the current signal to the voltage signal, and the VGA amplifies the signal to appropriate level for the ADC. The ADC was designed to digitize the waveform with a frequency of 100 MHz and a resolution of 6bits. Digital circuits consist of a free-running ADC and a multiplexer which were designed to convert a digitized 100 MHz/6bit signal to a 200 MHz/3bit one, which is effective for the reduction of the number and for the achievement of the high integration in one chip. This chip was designed and fabricated with 0.35 μm CMOS technology by ROHM and the size of the ASIC is 4.9 mm by 4.9 mm. The design concept and some experimental results are shown in this paper. -- Highlights: ► Waveform sampling (WS) ASIC is newly developed for pulse shape discrimination. ► WS ASIC can be used for radiation measurement and discrimination. ► WS ASIC is fabricated by submicron CMOS technology for 5 mm × 5 mm area. ► WS ASIC achieves high integration and can be used in very limited space

  5. Ultrafast disk lasers and amplifiers

    Science.gov (United States)

    Sutter, Dirk H.; Kleinbauer, Jochen; Bauer, Dominik; Wolf, Martin; Tan, Chuong; Gebs, Raphael; Budnicki, Aleksander; Wagenblast, Philipp; Weiler, Sascha

    2012-03-01

    Disk lasers with multi-kW continuous wave (CW) output power are widely used in manufacturing, primarily for cutting and welding applications, notably in the automotive industry. The ytterbium disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency, and high reliability with low investment and operating costs. Fundamental mode picosecond disk lasers are well established in micro machining at high throughput and perfect precision. Following the world's first market introduction of industrial grade 50 W picosecond lasers (TruMicro 5050) at the Photonics West 2008, the second generation of the TruMicro series 5000 now provides twice the average power (100 W at 1030 nm, or 60 W frequency doubled, green output) at a significantly reduced footprint. Mode-locked disk oscillators achieve by far the highest average power of any unamplified lasers, significantly exceeding the 100 W level in laboratory set-ups. With robust long resonators their multi-microjoule pulse energies begin to compete with typical ultrafast amplifiers. In addition, significant interest in disk technology has recently come from the extreme light laser community, aiming for ultra-high peak powers of petawatts and beyond.

  6. Ultra-Fast Hadronic Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, Dmitri [Fermilab; Lukić, Strahinja [VINCA Inst. Nucl. Sci., Belgrade; Mokhov, Nikolai [Fermilab; Striganov, Sergei [Fermilab; Ujić, Predrag [VINCA Inst. Nucl. Sci., Belgrade

    2017-12-18

    Calorimeters for particle physics experiments with integration time of a few ns will substantially improve the capability of the experiment to resolve event pileup and to reject backgrounds. In this paper time development of hadronic showers induced by 30 and 60 GeV positive pions and 120 GeV protons is studied using Monte Carlo simulation and beam tests with a prototype of a sampling steel-scintillator hadronic calorimeter. In the beam tests, scintillator signals induced by hadronic showers in steel are sampled with a period of 0.2 ns and precisely time-aligned in order to study the average signal waveform at various locations w.r.t. the beam particle impact. Simulations of the same setup are performed using the MARS15 code. Both simulation and test beam results suggest that energy deposition in steel calorimeters develop over a time shorter than 3 ns providing opportunity for ultra-fast calorimetry. Simulation results for an "ideal" calorimeter consisting exclusively of bulk tungsten or copper are presented to establish the lower limit of the signal integration window.

  7. Detection of mitochondrial DNA deletions in human cells induced by ionizing radiation

    International Nuclear Information System (INIS)

    Liu, Qing-Jie; Feng, Jiang-Bin; Lu, Xue; Li, Yu-Wen; Chen, De-Qing

    2008-01-01

    Full text: Purpose: To screen the novel mitochondrial DNA (mt DNA) deletions induced by ionizing radiation, and analyze the several kinds of mt DNA deletions, known as 3895 bp, 889 bp, 7436 bp or 4934 bp deletions. Methods: Long-range PCR with two pairs of primers, which could amplify the whole human mitochondrial genome, was used to analyze the lymphoblastoid cell line before and after exposed to 10 Gy 60 Co γ-rays. The limited condition PCR was used to certify the possible mt DNA deletion showed by long-range PCR. The PCR products were purified, cloned, sequenced and the sequence result were BLASTed. Regular PCR or nest-PCR were used to analyze the 3895 bp, 889 bp, 7436 bp or 4934 bp deletions before and after radiation exposure. The final PCR products were purified, sequenced and BALSTed on standard human mitochondrial genome sequence database. Results: (1) The predicted bands of mt DNA were observed on the control cell lines, and the possible mt DNA deletions were also detected on the irradiated cell lines. The deletions were certified by the limited condition PCR. The sequence BLAST results of the cloned PCR products showed that two kinds of deletions, 7455 bp deletion (nt 475-7929 in heavy strand) and 9225 bp deletion (nt 7714-369 in heavy strand), which were between two 8 bp direct repeats. Further bioinformatics analysis showed that the two deletions were novel deletions. (2) The 889 bp and 3895 bp deletion were not detected for the cell line samples not exposed to 60 Co γ-rays. The 889 bp and 3895 bp deletions were detected on samples exposed to 10 Gy 60 Co γ-rays. The BALST results showed that the 889 bp and 3895 deletions flanked nt 11688 bp-12576, nt 548 bp-4443, respectively. The 7436 bp deletion levels were not changed much before and after irradiation. (3) The 4934 bp deletions had the same pattern as 7436 bp deletion, but it could induced by radiation. Conclusions: Ionizing radiation could induce the human lymphoblastoid two novel mt DNA

  8. Effect of radiation dose level on the detectability of pulmonary nodules in chest tomosynthesis.

    Science.gov (United States)

    Asplund, Sara A; Johnsson, Åse A; Vikgren, Jenny; Svalkvist, Angelica; Flinck, Agneta; Boijsen, Marianne; Fisichella, Valeria A; Månsson, Lars Gunnar; Båth, Magnus

    2014-07-01

    To investigate the detectability of pulmonary nodules in chest tomosynthesis at reduced radiation dose levels. Eighty-six patients were included in the study and were examined with tomosynthesis and computed tomography (CT). Artificial noise was added to simulate that the tomosynthesis images were acquired at dose levels corresponding to 12, 32, and 70% of the default setting effective dose (0.12 mSv). Three observers (with >20, >20 and three years of experience) read the tomosynthesis cases for presence of nodules in a free-response receiver operating characteristics (FROC) study. CT served as reference. Differences between dose levels were calculated using the jack-knife alternative FROC (JAFROC) figure of merit (FOM). The JAFROC FOM was 0.45, 0.54, 0.55, and 0.54 for the 12, 32, 70, and 100% dose levels, respectively. The differences in FOM between the 12% dose level and the 32, 70, and 100% dose levels were 0.087 (p = 0.006), 0.099 (p = 0.003), and 0.093 (p = 0.004), respectively. Between higher dose levels, no significant differences were found. A substantial reduction from the default setting dose in chest tomosynthesis may be possible. In the present study, no statistically significant difference in detectability of pulmonary nodules was found when reducing the radiation dose to 32%. • A substantial radiation dose reduction in chest tomosynthesis may be possible. • Pulmonary nodule detectability remained unchanged at 32% of the effective dose. • Tomosynthesis might be performed at the dose of a lateral chest radiograph.

  9. A catheter-based radiation detector for endovascular detection of atheromatous plaques

    International Nuclear Information System (INIS)

    Mukai, Takahiro; Konishi, Junji; Nohara, Ryuji; Ogawa, Mikako; Ishino, Seigo; Saji, Hideo; Kambara, Naoshige; Kataoka, Kazuaki; Kanoi, Toru; Saito, Kazuhiro; Motomura, Hiroshi

    2004-01-01

    Although various radiopharmaceuticals have been developed for the detection of atheromas, external imaging techniques have limitations when it comes to the detection of small plaques. In this study, we developed a charged particle-sensitive detector for the endovascular detection of small plaques. The device consists of a probe, an automatic pullback unit and a controller. The probe, which consists of a plastic scintillator and flexible optical fibres, is 1.0 mm in diameter. The probe was inserted into a catheter placed on 18 F point sources, and then the radioactivity was measured as the probe was pulled out stepwise. The sensitivity for 18 F was 9.3 cps/kBq, and there was a close linear correlation between the peak counts and source dose until at least 0.8 MBq. Furthermore, this device showed low background counts ( 18 F point sources were set on the ball's surface. Even though 298 MBq of 18 F-fluorodeoxyglucose was injected into the ball, the point sources located every 10 mm on the ball's surface were detectable separately. The data gathered suggest that a catheter-based radiation detector in combination with charged particle-emitting radiopharmaceuticals is useful for the endovascular detection of small lesions such as coronary plaques. (orig.)

  10. Radiation detection at very low temperature. DRTBT 1996 Aussois - Course collection

    International Nuclear Information System (INIS)

    Bouchiat, Helene; Chardin, Gabriel; Cribier, Michel; L'Hote, Denis; Lamarre, Jean-Michel; Broniatowski, Alexandre; Feautrier, Philippe; Benoit, A.; Chapellier, Maurice; Torre, Jean-Pierre

    1996-11-01

    This publication gathers several courses which propose or address: Examples of studies of fundamental noises, Electronics of bolometers for the measurement of a radiation power, Digital processing of a signal, Kapitza resistance - thermal resistance between two solids, Ionisation-heat bolometers, Space projects using bolometers at very low temperature, Application of bolometric detection to sub-millimetre astrophysics (the SPM photometer on PRONAOS), The neutrino which came in from the cold, Application of bolometers to the analysis by ion beams, Counting of photons in visible and near infrared light - applications in astronomy

  11. Influence of surface active agents on the detection of beta radiation

    International Nuclear Information System (INIS)

    Mesquita, T.B.; Ruegg, E.F.

    1984-01-01

    It has been studied the efficiency of beta irradiation detection by liquid scintillation counting using the pesticide 14 C-lindane as radiation source and scientillation cocktails containing Triton-X, Arkopal, Tinoventin, Extravon-200, Oswalmida, Bigral, ethanol and methanol. Excepting the last 5 products, which led to a phase formation in the mixture, all other compounds, that are easily available in the local market, proved to be good substitute products for the well known Triton-X, an expensive and restrict emulsifier used for liquid scintillation measurement of aqueous solutions. (Author) [pt

  12. Asymmetric devices based on carbon nanotubes for terahertz-range radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, G. E., E-mail: gefedorov@mail.ru; Stepanova, T. S.; Gazaliev, A. Sh.; Gaiduchenko, I. A.; Kaurova, N. S.; Voronov, B. M.; Goltzman, G. N. [Moscow State Pedagogical University (Russian Federation)

    2016-12-15

    Various asymmetric detecting devices based on carbon nanotubes (CNTs) are studied. The asymmetry is understood as inhomogeneous properties along the conducting channel. In the first type of devices, an inhomogeneous morphology of the CNT grid is used. In the second type of devices, metals with highly varying work functions are used as the contact material. The relation between the sensitivity and detector configuration is analyzed. Based on the data obtained, approaches to the development of an efficient detector of terahertz radiation, based on carbon nanotubes are proposed.

  13. Method of shaping of direction-characterization of sensitivity of ionizing radiation detection probe

    International Nuclear Information System (INIS)

    Czarnecki, J.; Jaszczuk, J.; Kruczyk, M.; Slapa, M.; Wroblewski, T.

    1986-01-01

    A method of shaping of direction-characterization of sensitivity of the ionizing radiation detection probe, especially equipped with small gamma detectors is described. Two detectors are placed coaxially in the bases of the cylindrical shield. One of them is uncovered in the highest degree and the second is not covered to a maximum. The signals from them are processed on the standarized sequences of electrical impulses (taking into account the heights and the widths of the amplitude). 2 figs., 1 tab. (A.S.)

  14. A fast high-voltage current-peak detection system for the ALICE transition radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Verclas, Robert [Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg (Germany); Collaboration: ALICE-Collaboration

    2016-07-01

    During LHC operation in run 1, the gaseous detectors of ALICE occasionally experienced simultaneous trips in their high voltage which affected the majority of the high voltage channels. These trips are caused by large anode currents in the detector and are potentially related to LHC machine operations. We developed and installed a fast current-peak detection system for the ALICE Transition Radiation Detector. This system is based on FPGA technology and monitors 144 out 522 high voltage channels minimally invasively at a maximum readout rate of 2 MHz. It is an integral part of the LHC beam monitoring system. We report on the latest status.

  15. Detection by EPR method of radiation treatment in dried fruits containing crystalline sugar

    International Nuclear Information System (INIS)

    Lehner, K.; Stachowicz, W.

    2006-01-01

    The results of EPR (electron paramagnetic resonance) measurements are presented on the detection ability and stability of radiation induced sugar-born radicals in the samples of dried (dehydrated) fruits available in the market and related to doses of 0.5, 1 and 3 kGy, respectively. The experiments have been conducted during 12 months of storage. Measurements were done with an EPR - 10 MINI spectrometer in X band (frequency of microwaves 9.5 GHz), St. Petersburg Instruments Ltd. The aim of the work was to prove the reliability of acceptability of the method in routine control of irradiated food. (author)

  16. Detection of radiation deformation in crystalline polymers using the speckle photography technique

    International Nuclear Information System (INIS)

    El-Ghandoor, H.; Hashem, A.A.; Sharaf, F.

    1995-01-01

    In order to measure the resulting deformation due to gamma irradiation of polymers, a new optical technique, namely speckle-photography, was established and used. Thin films of tetrafluoroethene, with constant thickness were irradiated by different doses of gamma rays and the diffraction patterns of a laser beam passing through these films were recorded using the speckle photography technique. This technique has been applied to detect the radiation deformation in (Teflon) TFE, which is a crystalline polymer. A diffraction pattern due to the TFE thin layer is obtained and superimposed on the interference pattern displaying the speckle pattern pairs recorded on the same emulsion. (author)

  17. Electric field detection of coherent synchrotron radiation in a storage ring generated using laser bunch slicing

    International Nuclear Information System (INIS)

    Katayama, I.; Shimosato, H.; Bito, M.; Furusawa, K.; Adachi, M.; Zen, H.; Kimura, S.; Katoh, M.; Shimada, M.; Yamamoto, N.; Hosaka, M.; Ashida, M.

    2012-01-01

    The electric field of coherent synchrotron radiation (CSR) generated by laser bunch slicing in a storage ring has been detected by an electro-optic sampling method. The gate pulses for sampling are sent through a large-mode-area photonic-crystal fiber. The observed electric field profile of the CSR is in good agreement with the spectrum of the CSR observed using Fourier transform far-infrared spectrometry, indicating good phase stability in the CSR. The longitudinal density profiles of electrons modulated by laser pulses were evaluated from the electric field profile.

  18. The effectiveness of pretreatment physics plan review for detecting errors in radiation therapy

    International Nuclear Information System (INIS)

    Gopan, Olga; Zeng, Jing; Novak, Avrey; Nyflot, Matthew; Ford, Eric

    2016-01-01

    Purpose: The pretreatment physics plan review is a standard tool for ensuring treatment quality. Studies have shown that the majority of errors in radiation oncology originate in treatment planning, which underscores the importance of the pretreatment physics plan review. This quality assurance measure is fundamentally important and central to the safety of patients and the quality of care that they receive. However, little is known about its effectiveness. The purpose of this study was to analyze reported incidents to quantify the effectiveness of the pretreatment physics plan review with the goal of improving it. Methods: This study analyzed 522 potentially severe or critical near-miss events within an institutional incident learning system collected over a three-year period. Of these 522 events, 356 originated at a workflow point that was prior to the pretreatment physics plan review. The remaining 166 events originated after the pretreatment physics plan review and were not considered in the study. The applicable 356 events were classified into one of the three categories: (1) events detected by the pretreatment physics plan review, (2) events not detected but “potentially detectable” by the physics review, and (3) events “not detectable” by the physics review. Potentially detectable events were further classified by which specific checks performed during the pretreatment physics plan review detected or could have detected the event. For these events, the associated specific check was also evaluated as to the possibility of automating that check given current data structures. For comparison, a similar analysis was carried out on 81 events from the international SAFRON radiation oncology incident learning system. Results: Of the 356 applicable events from the institutional database, 180/356 (51%) were detected or could have been detected by the pretreatment physics plan review. Of these events, 125 actually passed through the physics review; however

  19. The effectiveness of pretreatment physics plan review for detecting errors in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gopan, Olga; Zeng, Jing; Novak, Avrey; Nyflot, Matthew; Ford, Eric, E-mail: eford@uw.edu [Department of Radiation Oncology, University of Washington Medical Center, 1959 NE Pacific Street, Box 356043, Seattle, Washington 98195 (United States)

    2016-09-15

    Purpose: The pretreatment physics plan review is a standard tool for ensuring treatment quality. Studies have shown that the majority of errors in radiation oncology originate in treatment planning, which underscores the importance of the pretreatment physics plan review. This quality assurance measure is fundamentally important and central to the safety of patients and the quality of care that they receive. However, little is known about its effectiveness. The purpose of this study was to analyze reported incidents to quantify the effectiveness of the pretreatment physics plan review with the goal of improving it. Methods: This study analyzed 522 potentially severe or critical near-miss events within an institutional incident learning system collected over a three-year period. Of these 522 events, 356 originated at a workflow point that was prior to the pretreatment physics plan review. The remaining 166 events originated after the pretreatment physics plan review and were not considered in the study. The applicable 356 events were classified into one of the three categories: (1) events detected by the pretreatment physics plan review, (2) events not detected but “potentially detectable” by the physics review, and (3) events “not detectable” by the physics review. Potentially detectable events were further classified by which specific checks performed during the pretreatment physics plan review detected or could have detected the event. For these events, the associated specific check was also evaluated as to the possibility of automating that check given current data structures. For comparison, a similar analysis was carried out on 81 events from the international SAFRON radiation oncology incident learning system. Results: Of the 356 applicable events from the institutional database, 180/356 (51%) were detected or could have been detected by the pretreatment physics plan review. Of these events, 125 actually passed through the physics review; however

  20. Progress in Ultrafast Intense Laser Science II

    CERN Document Server

    Yamanouchi, Kaoru; Agostini, Pierre; Ferrante, Gaetano

    2007-01-01

    This book series addresses a newly emerging interdisciplinary research field, Ultrafast Intense Laser Science, spanning atomic and molecular physics, molecular science, and optical science. Its progress is being stimulated by the recent development of ultrafast laser technologies. Highlights of this second volume include Coulomb explosion and fragmentation of molecules, control of chemical dynamics, high-order harmonic generation, propagation and filamentation, and laser-plasma interaction. All chapters are authored by foremost experts in their fields and the texts are written at a level accessible to newcomers and graduate students, each chapter beginning with an introductory overview.

  1. Progress in ultrafast intense laser science XI

    CERN Document Server

    Yamanouchi, Kaoru; Martin, Philippe

    2014-01-01

    The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance

  2. Progress in ultrafast intense laser science

    CERN Document Server

    Yamanouchi, Kaoru; Mathur, Deepak

    2014-01-01

    The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance

  3. Ultrafast Nonlinear Signal Processing in Silicon Waveguides

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen; Hu, Hao

    2012-01-01

    We describe recent demonstrations of exploiting highly nonlinear silicon waveguides for ultrafast optical signal processing. We describe wavelength conversion and serial-to-parallel conversion of 640 Gbit/s data signals and 1.28 Tbit/s demultiplexing and all-optical sampling.......We describe recent demonstrations of exploiting highly nonlinear silicon waveguides for ultrafast optical signal processing. We describe wavelength conversion and serial-to-parallel conversion of 640 Gbit/s data signals and 1.28 Tbit/s demultiplexing and all-optical sampling....

  4. Detection of helium atoms in irradiated metals using positron annihilation radiation

    International Nuclear Information System (INIS)

    Xu, Q.; Sato, K.; Yoshiie, T.; Ishizaki, T.; Nagata, S.

    2007-01-01

    Iron alloys are used widely in the nuclear industry. The production of He atoms induced by nuclear reaction increases with increasing neutron energy, and the interaction between He and defects becomes important in the fusion reactor. A new composition analysis method, coincidence Doppler broadening (CDB) of positron annihilation radiation, was employed to detect He atoms in ion irradiated Fe. The results of positron lifetime showed that the microvoids and voids were formed in ion irradiated Fe. The results of CDB measurement indicated that He atoms exited in the microvoids, and they exited in the microvoids even after annealing at 1223 K in ion irradiated Fe. CDB measurement, which is a nondestructive technique for testing materials, is an available method to detect He atoms. (authors)

  5. Design of Zigbee-Based Wireless Sensor suitable for Radiation Detection and Monitoring

    International Nuclear Information System (INIS)

    Madian, A.A.

    2012-01-01

    This paper presents a design for a wireless sensor nuclear radiation monitoring and detection based on Zigbee. The system consists of transmitter and receiver modules. The wireless sensor installed at transmitter whiles the receiver processing data. The communication between Tx and Rx done through Zigbee module using the protocol of CSMA/CA. The Zigbee has the advantages of reliable, power-efficient, and low-latency communications between low-cost Tx/Rx.The wireless sensor implementation can easily be deployed to discover unusual or abnormal radioactivity. The sensors are convenient to be installed indoors or outdoors, as well as to be mounted on mobile equipment's. All wireless nuclear detection sensors are designed using micro controller and other integrated systems

  6. Hybrid emergency radiation detection: a wireless sensor network application for consequence management of a radiological release

    Science.gov (United States)

    Kyker, Ronald D.; Berry, Nina; Stark, Doug; Nachtigal, Noel; Kershaw, Chris

    2004-08-01

    The Hybrid Emergency Radiation Detection (HERD) system is a rapidly deployable ad-hoc wireless sensor network for monitoring the radiation hazard associated with a radiation release. The system is designed for low power, small size, low cost, and rapid deployment in order to provide early notification and minimize exposure. The many design tradeoffs, decisions, and challenges in the implementation of this wireless sensor network design will be presented and compared to the commercial systems available. Our research in a scaleable modular architectural highlights the need and implementation of a system level approach that provides flexibility and adaptability for a variety of applications. This approach seeks to minimize power, provide mission specific specialization, and provide the capability to upgrade the system with the most recent technology advancements by encapsulation and modularity. The implementation of a low power, widely available Real Time Operating System (RTOS) for multitasking with an improvement in code maintenance, portability, and reuse will be presented. Finally future design enhancements technology trends affecting wireless sensor networks will be presented.

  7. Lower limits of detection in using carbon nanotubes as thermoluminescent dosimeters of beta radiation

    Science.gov (United States)

    Alanazi, Abdulaziz; Jurewicz, Izabela; Alalawi, Amani I.; Alyahyawi, Amjad; Alsubaie, Abdullah; Hinder, Steven; Bañuls-Ciscar, Jorge; Alkhorayef, Mohammed; Bradley, D. A.

    2017-11-01

    World-wide, on-going intensive research is being seen in adaptation of carbon nanotubes (CNTs) for a wide variety of applications, particular interest herein being in the thermoluminescent (TL) properties of CNTs and their sensitivity towards energetic radiations. Using beta radiation delivering dose levels of a few Gy it has been observed in previous study that strain and impurity defects in CNTs give rise to significant TL yields, providing an initial measure of the extent to which electron trapping centres exist in various qualities of CNT, from super-pure to raw. This in turn points to the possibility that there may be considerable advantage in using such media for radiation dosimetry applications, including for in vivo dosimetry. CNTs also have an effective atomic number similar to that of adipose tissue, making them suitable for soft tissue dosimetry. In present investigations various single-wall carbon nanotubes (SWCNT) samples in the form of buckypaper have been irradiated to doses in the range 35-1.3 Gy, use being made of a 90Sr beta source, the response of the CNTs buckypaper with dose showing a trend towards linearity. It is shown for present production methodology for buckypaper samples that the raw SWCNT buckypaper offer the greatest sensitivity, detecting doses down to some few tens of mGy.

  8. Detection of coherent X-ray transition radiation and its application to beam diagnostics

    International Nuclear Information System (INIS)

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.I.; Li Qiang; Moran, M.J.; Bergstrom, J.C.; Caplan, H.S.; Silzer, R.M.; Skopik, D.M.; Rothbart, G.B.

    1989-01-01

    We investigate the use of coherent X-ray transition radiation to measure the energy of ultra-relativistic charged particles. This can be used for beam diagnostics for both high-repetition-rate and single-pulse, high-current accelerators. The research also has possible applications for the detection and identification of these particles. By selecting foil thickness and spacing, it is possible to design radiators whose angle of emission varies radically over a range of charged particle energies. We have constructed three coherent radiators and tested them at two accelerators using electron beam energies ranging from 50 to 228 MeV. Soft X-ray emission (1-3 keV) was emitted in a circularly symmetrical annulus with half-angle divergence of 2.5-9.0 mrad. The angle of peak emission was found to increase with electron-beam energy, in contrast to the incoherent case for which the angle of emission varies inversely with electron-beam energy. (orig.)

  9. Quality control of radiation counting systems and measurement of minimum detectable activity

    International Nuclear Information System (INIS)

    Song, Byoung Chul; Han, Sung Sim; Kim, Young Bok; Jee, Kwang Yong; Sohn, Se Chul

    2004-01-01

    Various radiation counters have been using to determine radioactivity of radwastes for disposal. A radiation counting system was set up using a radiation detector chosen in this study and its stability was investigated through the periodic determination of background and counting efficiencies in accordance with a quality control program to increase the confidence level. The average background level for the γ-spectrometer was 1.59 cps and the average counting level for the standard sample was 45248 dps within 20 confidence levels. The average alpha background level for the low background α/β counting system was 0.31 cpm and the efficiency for alpha counting was 34.38 %. The average beta background level for the α/β counting system was 1.30 cpm and the efficiency for beta counting was 46.5%. The background level in the region of 3H and 14C for the liquid scintillation counting system was 2.52 and 3.31 cpm and the efficiency for alpha counting was 58.5 and 95.6%, respectively. The minimum detectable activity for the γ-spectrometer was found to be 3.2 Bq/mL and 3.8 Bq/mL for the liquid scintillation counter, and 20.5 and 23.0 Bq/mL, respectively for the α and β counting system

  10. High peak power THz source for ultrafast electron diffraction

    Directory of Open Access Journals (Sweden)

    Shengguang Liu

    2018-01-01

    Full Text Available Terahertz (THz science and technology have already become the research highlight at present. In this paper, we put forward a device setup to carry out ultrafast fundamental research. A photocathode RF gun generates electron bunches with ∼MeV energy, ∼ps bunch width and about 25pC charge. The electron bunches inject the designed wiggler, the coherent radiation at THz spectrum emits from these bunches and increases rapidly until the saturation at ∼MW within a short wiggler. THz pulses can be used as pump to stimulate an ultra-short excitation in some kind of sample. Those electron bunches out of wiggler can be handled into bunches with ∼1pC change, small beam spot and energy spread to be probe. Because the pump and probe comes from the same electron source, synchronization between pump and probe is inherent. The whole facility can be compacted on a tabletop.

  11. Cascaded nonlinearities for ultrafast nonlinear optical science and applications

    DEFF Research Database (Denmark)

    Bache, Morten

    the cascading nonlinearity is investigated in detail, especially with focus on femtosecond energetic laser pulses being subjected to this nonlinear response. Analytical, numerical and experimental results are used to understand the cascading interaction and applications are demonstrated. The defocusing soliton...... observations with analogies in fiber optics are observed numerically and experimentally, including soliton self-compression, soliton-induced resonant radiation, supercontinuum generation, optical wavebreaking and shock-front formation. All this happens despite no waveguide being present, thanks...... is of particular interest here, since it is quite unique and provides the solution to a number of standing challenges in the ultrafast nonlinear optics community. It solves the problem of catastrophic focusing and formation of a filaments in bulk glasses, which even under controlled circumstances is limited...

  12. Anapole nanolasers for mode-locking and ultrafast pulse generation

    KAUST Repository

    Gongora, J. S. Totero; Miroshnichenko, Andrey E.; Kivshar, Yuri S.; Fratalocchi, Andrea

    2017-01-01

    Nanophotonics is a rapidly developing field of research with many suggestions for a design of nanoantennas, sensors and miniature metadevices. Despite many proposals for passive nanophotonic devices, the efficient coupling of light to nanoscale optical structures remains a major challenge. In this article, we propose a nanoscale laser based on a tightly confined anapole mode. By harnessing the non-radiating nature of the anapole state, we show how to engineer nanolasers based on InGaAs nanodisks as on-chip sources with unique optical properties. Leveraging on the near-field character of anapole modes, we demonstrate a spontaneously polarized nanolaser able to couple light into waveguide channels with four orders of magnitude intensity than classical nanolasers, as well as the generation of ultrafast (of 100 fs) pulses via spontaneous mode locking of several anapoles. Anapole nanolasers offer an attractive platform for monolithically integrated, silicon photonics sources for advanced and efficient nanoscale circuitry.

  13. Anapole nanolasers for mode-locking and ultrafast pulse generation

    KAUST Repository

    Gongora, J. S. Totero

    2017-05-31

    Nanophotonics is a rapidly developing field of research with many suggestions for a design of nanoantennas, sensors and miniature metadevices. Despite many proposals for passive nanophotonic devices, the efficient coupling of light to nanoscale optical structures remains a major challenge. In this article, we propose a nanoscale laser based on a tightly confined anapole mode. By harnessing the non-radiating nature of the anapole state, we show how to engineer nanolasers based on InGaAs nanodisks as on-chip sources with unique optical properties. Leveraging on the near-field character of anapole modes, we demonstrate a spontaneously polarized nanolaser able to couple light into waveguide channels with four orders of magnitude intensity than classical nanolasers, as well as the generation of ultrafast (of 100 fs) pulses via spontaneous mode locking of several anapoles. Anapole nanolasers offer an attractive platform for monolithically integrated, silicon photonics sources for advanced and efficient nanoscale circuitry.

  14. Applications in Bioastronautics and Bioinformatics: Early Radiation Cataracts Detected by Noninvasive, Quantitative, and Remote Means

    Science.gov (United States)

    Ansari, Rafat R.; King, James F.; Giblin, Frank J.

    2000-01-01

    Human exploration of Mars is a key goal in NASA's exploration planning in the next 20 years. Maintaining crew health and good vision is certainly an important aspect of achieving a successful mission. Continuous radiation exposure is a risk factor for radiation-induced cataracts in astronauts because radiation exposure in space travel has the potential of accelerating the aging process (ref. 1). A patented compact device (ref. 2) based on the technique of dynamic light scattering (DLS) was designed for monitoring an astronaut's ocular health during long-duration space travel. This capability of early diagnosis, unmatched by any other clinical technique in use today, may enable prompt initiation of preventive/curative therapy. An Internet web-based system integrating photon correlation data and controlling the hardware to monitor cataract development in vivo at a remote site in real time (teleophthalmology) is currently being developed. The new technology detects cataracts very early (at the molecular level). Cataract studies onboard the International Space Station will be helpful in quantifying any adverse effect of radiation to ocular health. The normal lens in a human eye, situated behind the cornea, is a transparent tissue. It contains 35 wt % protein and 65 wt % water. Aging, disease (e.g., diabetes), smoking, dehydration, malnutrition, and exposure to ultraviolet light and ionizing radiation can cause agglomeration of the lens proteins. Protein aggregation can take place anywhere in the lens, causing lens opacity. The aggregation and opacification could produce nuclear (central portion of the lens) or cortical (peripheral) cataracts. Nuclear and posterior subcapsular (the membrane's capsule surrounds the whole lens) cataracts, being on the visual optical axis of the eye, cause visual impairment that can finally lead to blindness. The lens proteins, in their native state, are small in size. As a cataract develops, this size grows from a few nanometers

  15. Ultra-Fast Image Reconstruction of Tomosynthesis Mammography Using GPU.

    Science.gov (United States)

    Arefan, D; Talebpour, A; Ahmadinejhad, N; Kamali Asl, A

    2015-06-01

    Digital Breast Tomosynthesis (DBT) is a technology that creates three dimensional (3D) images of breast tissue. Tomosynthesis mammography detects lesions that are not detectable with other imaging systems. If image reconstruction time is in the order of seconds, we can use Tomosynthesis systems to perform Tomosynthesis-guided Interventional procedures. This research has been designed to study ultra-fast image reconstruction technique for Tomosynthesis Mammography systems using Graphics Processing Unit (GPU). At first, projections of Tomosynthesis mammography have been simulated. In order to produce Tomosynthesis projections, it has been designed a 3D breast phantom from empirical data. It is based on MRI data in its natural form. Then, projections have been created from 3D breast phantom. The image reconstruction algorithm based on FBP was programmed with C++ language in two methods using central processing unit (CPU) card and the Graphics Processing Unit (GPU). It calculated the time of image reconstruction in two kinds of programming (using CPU and GPU).

  16. Ultrafast photon counting applied to resonant scanning STED microscopy.

    Science.gov (United States)

    Wu, Xundong; Toro, Ligia; Stefani, Enrico; Wu, Yong

    2015-01-01

    To take full advantage of fast resonant scanning in super-resolution stimulated emission depletion (STED) microscopy, we have developed an ultrafast photon counting system based on a multigiga sample per second analogue-to-digital conversion chip that delivers an unprecedented 450 MHz pixel clock (2.2 ns pixel dwell time in each scan). The system achieves a large field of view (∼50 × 50 μm) with fast scanning that reduces photobleaching, and advances the time-gated continuous wave STED technology to the usage of resonant scanning with hardware-based time-gating. The assembled system provides superb signal-to-noise ratio and highly linear quantification of light that result in superior image quality. Also, the system design allows great flexibility in processing photon signals to further improve the dynamic range. In conclusion, we have constructed a frontier photon counting image acquisition system with ultrafast readout rate, excellent counting linearity, and with the capacity of realizing resonant-scanning continuous wave STED microscopy with online time-gated detection. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  17. TERA-MIR radiation: materials, generation, detection and applications III (Conference Presentation)

    Science.gov (United States)

    Pereira, Mauro F.

    2016-10-01

    This talk summarizes the achievements of COST ACTION MP1204 during the last four years. [M.F. Pereira, Opt Quant Electron 47, 815-820 (2015).]. TERA-MIR main objectives are to advance novel materials, concepts and device designs for generating and detecting THz and Mid Infrared radiation using semiconductor, superconductor, metamaterials and lasers and to beneficially exploit their common aspects within a synergetic approach. We used the unique networking and capacity-building capabilities provided by the COST framework to unify these two spectral domains from their common aspects of sources, detectors, materials and applications. We created a platform to investigate interdisciplinary topics in Physics, Electrical Engineering and Technology, Applied Chemistry, Materials Sciences and Biology and Radio Astronomy. The main emphasis has been on new fundamental material properties, concepts and device designs that are likely to open the way to new products or to the exploitation of new technologies in the fields of sensing, healthcare, biology, and industrial applications. End users are: research centres, academic, well-established and start-up Companies and hospitals. Results are presented along our main lines of research: Intersubband materials and devices with applications to fingerprint spectroscopy; Metamaterials, photonic crystals and new functionalities; Nonlinearities and interaction of radiation with matter including biomaterials; Generation and Detection based on Nitrides and Bismides. The talk is closed by indicating the future direction of the network that will remain active beyond the funding period and our expectations for future joint research.

  18. Chemical vapor deposition diamond based multilayered radiation detector: Physical analysis of detection properties

    International Nuclear Information System (INIS)

    Almaviva, S.; Marinelli, Marco; Milani, E.; Prestopino, G.; Tucciarone, A.; Verona, C.; Verona-Rinati, G.; Angelone, M.; Pillon, M.; Dolbnya, I.; Sawhney, K.; Tartoni, N.

    2010-01-01

    Recently, solid state photovoltaic Schottky diodes, able to detect ionizing radiation, in particular, x-ray and ultraviolet radiation, have been developed at the University of Rome 'Tor Vergata'. We report on a physical and electrical properties analysis of the device and a detailed study of its detection capabilities as determined by its electrical properties. The design of the device is based on a metal/nominally intrinsic/p-type diamond layered structure obtained by microwave plasma chemical vapor deposition of homoepitaxial single crystal diamond followed by thermal evaporation of a metallic contact. The device can operate in an unbiased mode by using the built-in potential arising from the electrode-diamond junction. We compare the expected response of the device to photons of various energies calculated through Monte Carlo simulation with experimental data collected in a well controlled experimental setup i.e., monochromatic high flux x-ray beams from 6 to 20 keV, available at the Diamond Light Source synchrotron in Harwell (U.K.).

  19. Effect of radiation dose level on the detectability of pulmonary nodules in chest tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, Sara A.; Svalkvist, Angelica; Maansson, Lars Gunnar; Baath, Magnus [University of Gothenburg, Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Medical Physics and Biomedical Engineering, Gothenburg (Sweden); Johnsson, Aase A.; Vikgren, Jenny; Flinck, Agneta; Boijsen, Marianne; Fisichella, Valeria A. [University of Gothenburg, Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Radiology, Gothenburg (Sweden)

    2014-07-15

    To investigate the detectability of pulmonary nodules in chest tomosynthesis at reduced radiation dose levels. Eighty-six patients were included in the study and were examined with tomosynthesis and computed tomography (CT). Artificial noise was added to simulate that the tomosynthesis images were acquired at dose levels corresponding to 12, 32, and 70 % of the default setting effective dose (0.12 mSv). Three observers (with >20, >20 and three years of experience) read the tomosynthesis cases for presence of nodules in a free-response receiver operating characteristics (FROC) study. CT served as reference. Differences between dose levels were calculated using the jack-knife alternative FROC (JAFROC) figure of merit (FOM). The JAFROC FOM was 0.45, 0.54, 0.55, and 0.54 for the 12, 32, 70, and 100 % dose levels, respectively. The differences in FOM between the 12 % dose level and the 32, 70, and 100 % dose levels were 0.087 (p = 0.006), 0.099 (p = 0.003), and 0.093 (p = 0.004), respectively. Between higher dose levels, no significant differences were found. A substantial reduction from the default setting dose in chest tomosynthesis may be possible. In the present study, no statistically significant difference in detectability of pulmonary nodules was found when reducing the radiation dose to 32 %. (orig.)

  20. Effect of radiation dose level on the detectability of pulmonary nodules in chest tomosynthesis

    International Nuclear Information System (INIS)

    Asplund, Sara A.; Svalkvist, Angelica; Maansson, Lars Gunnar; Baath, Magnus; Johnsson, Aase A.; Vikgren, Jenny; Flinck, Agneta; Boijsen, Marianne; Fisichella, Valeria A.

    2014-01-01

    To investigate the detectability of pulmonary nodules in chest tomosynthesis at reduced radiation dose levels. Eighty-six patients were included in the study and were examined with tomosynthesis and computed tomography (CT). Artificial noise was added to simulate that the tomosynthesis images were acquired at dose levels corresponding to 12, 32, and 70 % of the default setting effective dose (0.12 mSv). Three observers (with >20, >20 and three years of experience) read the tomosynthesis cases for presence of nodules in a free-response receiver operating characteristics (FROC) study. CT served as reference. Differences between dose levels were calculated using the jack-knife alternative FROC (JAFROC) figure of merit (FOM). The JAFROC FOM was 0.45, 0.54, 0.55, and 0.54 for the 12, 32, 70, and 100 % dose levels, respectively. The differences in FOM between the 12 % dose level and the 32, 70, and 100 % dose levels were 0.087 (p = 0.006), 0.099 (p = 0.003), and 0.093 (p = 0.004), respectively. Between higher dose levels, no significant differences were found. A substantial reduction from the default setting dose in chest tomosynthesis may be possible. In the present study, no statistically significant difference in detectability of pulmonary nodules was found when reducing the radiation dose to 32 %. (orig.)

  1. Application of random-point processes to the detection of radiation sources

    International Nuclear Information System (INIS)

    Woods, J.W.

    1978-01-01

    In this report the mathematical theory of random-point processes is reviewed and it is shown how use of the theory can obtain optimal solutions to the problem of detecting radiation sources. As noted, the theory also applies to image processing in low-light-level or low-count-rate situations. Paralleling Snyder's work, the theory is extended to the multichannel case of a continuous, two-dimensional (2-D), energy-time space. This extension essentially involves showing that the data are doubly stochastic Poisson (DSP) point processes in energy as well as time. Further, a new 2-D recursive formulation is presented for the radiation-detection problem with large computational savings over nonrecursive techniques when the number of channels is large (greater than or equal to 30). Finally, some adaptive strategies for on-line ''learning'' of unknown, time-varying signal and background-intensity parameters and statistics are present and discussed. These adaptive procedures apply when a complete statistical description is not available a priori

  2. Summary Report for the Radiation Detection for Nuclear Security Summer School 2014

    Energy Technology Data Exchange (ETDEWEB)

    Runkle, Robert C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baciak, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Woodring, Mitchell L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jenno, Diana M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-01

    Executive Summary The Pacific Northwest National Laboratory (PNNL) hosted students from across the United States at the 3rd Radiation Detection for Nuclear Security Summer School from 16 – 27 June 2014. The summer school provided students with a unique understanding of nuclear security challenges faced in the field and exposed them to the technical foundations, analyses, and insight that will be required by future leaders in technology development and implementation. The course heavily emphasized laboratory and field demonstrations including direct measurements of special nuclear material. Student evaluations and feedback from student advisors indicates that the summer school achieved its objectives of 1) exposing students to the range of nuclear security applications for which radiation detection is necessary, 2) articulating the relevance of student research into the broader context, and 3) exciting students about the possibility of future careers in nuclear security. In fact, we are beginning to see previous students both enroll in graduate programs (former undergraduates) and complete internships at agencies like the National Nuclear Security Administration.

  3. Effect of ionizing radiation on the quantitative detection of Salmonella using real-time PCR

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sangyong; Jung, Jinwoo [Radiation Research Center for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kim, Minjeong; Ryu, Sangryeol [Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921 (Korea, Republic of); Kim, Dongho [Radiation Research Center for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: fungikim@kaeri.re.kr

    2008-09-15

    Food irradiation is an economically viable technology for inactivating foodborne pathogens, but irradiation can mask pathogens in unhygienically prepared food. The aim of this study was to investigate the effect of irradiation treatment on the detection of Salmonella using real-time PCR. Three commercially available kits were tested, of which the InstaGene Matrix procedure was most effective in preparing template DNA from Salmonella exposed to radiation in broth culture. The minimum level of detection by real-time PCR combined with InstaGene Matrix was 3 log units of Salmonella per milliliter. However, when pure cultures of Salmonella were irradiated at 3 and 5 kGy, the cycle threshold (C{sub T}) increased 1-1.5-fold compared to irradiation at 0 and 1 kGy. This indicated that irradiation treatment may result in an underestimation of bacterial counts due to radiation-induced DNA lesions. We also compared C{sub T} values in inoculated chicken homogenates before and after irradiation, which in this model caused a 1.3-3.3-fold underestimation of bacterial counts with respect to irradiation dose.

  4. Effects of Ionizing Radiation on Biological Molecules—Mechanisms of Damage and Emerging Methods of Detection

    Science.gov (United States)

    Reisz, Julie A.; Bansal, Nidhi; Qian, Jiang; Zhao, Weiling

    2014-01-01

    Abstract Significance: The detrimental effects of ionizing radiation (IR) involve a highly orchestrated series of events that are amplified by endogenous signaling and culminating in oxidative damage to DNA, lipids, proteins, and many metabolites. Despite the global impact of IR, the molecular mechanisms underlying tissue damage reveal that many biomolecules are chemoselectively modified by IR. Recent Advances: The development of high-throughput “omics” technologies for mapping DNA and protein modifications have revolutionized the study of IR effects on biological systems. Studies in cells, tissues, and biological fluids are used to identify molecular features or biomarkers of IR exposure and response and the molecular mechanisms that regulate their expression or synthesis. Critical Issues: In this review, chemical mechanisms are described for IR-induced modifications of biomolecules along with methods for their detection. Included with the detection methods are crucial experimental considerations and caveats for their use. Additional factors critical to the cellular response to radiation, including alterations in protein expression, metabolomics, and epigenetic factors, are also discussed. Future Directions: Throughout the review, the synergy of combined “omics” technologies such as genomics and epigenomics, proteomics, and metabolomics is highlighted. These are anticipated to lead to new hypotheses to understand IR effects on biological systems and improve IR-based therapies. Antioxid. Redox Signal. 21: 260–292. PMID:24382094

  5. Detection of radiation treatment of meat by novel techniques of DNA comet assay

    International Nuclear Information System (INIS)

    Khan, A.A.; Khan, H.M.

    2002-01-01

    Treatment of food to ionizing radiation is being progressively used in many countries to inactivate food pathogens, to eradicate pests and to extend shelf life; thereby contributing to safer and more plentiful food supply. Food control agencies throughout the world need some reliable, simple and rapid methods for detection of irradiated foods to ensure free choice of consumer and to enforce labeling. The DNA comet assay offers great potential as a rapid tool to screen irradiated and unirradiated samples of several kinds of foods. In the present study, frozen beef has been investigated for detection of irradiation treatment. The samples were subjected to radiation doses of 0,4,5 and 7.0 kGy and were stored in freezer before analysis. The cells were extracted into cold PBS solutions, embedded into the agarose gel on microscope slides, lysed and electrophoressed at a voltage of 2v/cm for 2 min. The fragmented DNA as a result of irradiation treatment was stretched in the gel producing the dose dependent comets. These comets were visible using a simple transmission microscope after silver staining. The controlled and irradiated samples of meat were clearly distinguishable on the basis of the stained patterns of DNA in form of round or conical intact cells for unirradiated samples or in form of comets for irradiated samples. It is therefore, concluded that 'DNA Comet Assay' offers a potential to screen unirradiated and irradiated meat samples. (author)

  6. Fourier Transform Infrared Radiation Spectroscopy Applied for Wood Rot Decay and Mould Fungi Growth Detection

    Directory of Open Access Journals (Sweden)

    Bjørn Petter Jelle

    2012-01-01

    Full Text Available Material characterization may be carried out by the attenuated total reflectance (ATR Fourier transform infrared (FTIR radiation spectroscopical technique, which represents a powerful experimental tool. The ATR technique may be applied on both solid state materials, liquids, and gases with none or only minor sample preparations, also including materials which are nontransparent to IR radiation. This facilitation is made possible by pressing the sample directly onto various crystals, for example, diamond, with high refractive indices, in a special reflectance setup. Thus ATR saves time and enables the study of materials in a pristine condition, that is, the comprehensive sample preparation by pressing thin KBr pellets in traditional FTIR transmittance spectroscopy is hence avoided. Materials and their ageing processes, both ageing by natural and accelerated climate exposure, decomposition and formation of chemical bonds and products, may be studied in an ATR-FTIR analysis. In this work, the ATR-FTIR technique is utilized to detect wood rot decay and mould fungi growth on various building material substrates. An experimental challenge and aim is to be able to detect the wood rot decay and mould fungi growth at early stages when it is barely visible to the naked eye. Another goal is to be able to distinguish between various species of fungi and wood rot.

  7. Hypothesis tests for the detection of constant speed radiation moving sources

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan; Coulon, Romain; Kondrasovs, Vladimir; Boudergui, Karim; Sannie, Guillaume; Gameiro, Jordan; Normand, Stephane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 99 Gif-sur-Yvette, (France); Mechin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 4050 Caen, (France)

    2015-07-01

    Radiation Portal Monitors are deployed in linear network to detect radiological material in motion. As a complement to single and multichannel detection algorithms, inefficient under too low signal to noise ratios, temporal correlation algorithms have been introduced. Test hypothesis methods based on empirically estimated mean and variance of the signals delivered by the different channels have shown significant gain in terms of a tradeoff between detection sensitivity and false alarm probability. This paper discloses the concept of a new hypothesis test for temporal correlation detection methods, taking advantage of the Poisson nature of the registered counting signals, and establishes a benchmark between this test and its empirical counterpart. The simulation study validates that in the four relevant configurations of a pedestrian source carrier under respectively high and low count rate radioactive background, and a vehicle source carrier under the same respectively high and low count rate radioactive background, the newly introduced hypothesis test ensures a significantly improved compromise between sensitivity and false alarm, while guaranteeing the stability of its optimization parameter regardless of signal to noise ratio variations between 2 to 0.8. (authors)

  8. Ruggedization of CdZnTe detectors and detector assemblies for radiation detection applications

    Energy Technology Data Exchange (ETDEWEB)

    Lu, P.H., E-mail: pinghe.lu@redlen.com; Gomolchuk, P.; Chen, H.; Beitz, D.; Grosser, A.W.

    2015-06-01

    This paper described improvements in the ruggedization of CdZnTe detectors and detector assemblies for use in radiation detection applications. Research included experimenting with various conductive and underfill adhesive material systems suitable for CZT substrates. A detector design with encapsulation patterning was developed to protect detector surfaces and to control spacing between CZT anode and PCB carrier. Robustness of bare detectors was evaluated through temperature cycling and metallization shear testing. Attachment processes using well-chosen adhesives and PCB carrier materials were optimized to improve reliability of detector assemblies, resulted in Improved Attachment Detector Assembly. These detector assemblies were subjected to aggressive temperature cycling, and varying levels of drop/shock and vibration, in accordance with modified JEDEC, ANSI and FedEx testing standards, to assess their ruggedness. Further enhanced detector assembly ruggedization methods were investigated involving adhesive conformal coating, potting and dam filling on detector assemblies, which resulted in the Enhanced Ruggedization Detector Assembly. Large numbers of CZT detectors and detector assemblies with 5 mm and 15 mm thick, over 200 in total, were tested. Their performance was evaluated by exposure to various radioactive sources using comprehensive predefined detector specifications and testing protocols. Detector assemblies from improved attachment and enhanced ruggedization showed stable performances during the harsh environmental condition tests. In conclusion, significant progress has been made in improving the reliability and enhancing the ruggedness of CZT detector assemblies for radiation detection applications deployed in operational environments. - Highlights: • We developed ruggedization methods to enhance reliability of CZT detector assemblies. • Attachment of CZT radiation detectors was improved through comparative studies. • Bare detector metallization

  9. Europa's surface radiation environment and considerations for in-situ sampling and biosignature detection

    Science.gov (United States)

    Nordheim, T.; Paranicas, C.; Hand, K. P.

    2017-12-01

    Jupiter's moon Europa is embedded deep within the Jovian magnetosphere and is thus exposed to bombardment by charged particles, from thermal plasma to more energetic particles at radiation belt energies. In particular, energetic charged particles are capable of affecting the uppermost layer of surface material on Europa, in some cases down to depths of several meters (Johnson et al., 2004; Paranicas et al., 2009, 2002). Examples of radiation-induced surface alteration include sputtering, radiolysis and grain sintering; processes that are capable of significantly altering the physical properties of surface material. Radiolysis of surface ices containing sulfur-bearing contaminants from Io has been invoked as a possible explanation for hydrated sulfuric acid detected on Europa's surface (Carlson et al., 2002, 1999) and radiolytic production of oxidants represents a potential source of energy for life that could reside within Europa's sub-surface ocean (Chyba, 2000; Hand et al., 2007; Johnson et al., 2003; Vance et al., 2016). Accurate knowledge of Europa's surface radiation environment is essential to the interpretation of space and Earth-based observations of Europa's surface and exosphere. Furthermore, future landed missions may seek to sample endogenic material emplaced on Europa's surface to investigate its chemical composition and to search for biosignatures contained within. Such material would likely be sampled from the shallow sub-surface, and thus, it becomes crucial to know to which degree this material is expected to have been radiation processed.Here we will present modeling results of energetic electron and proton bombardment of Europa's surface, including interactions between these particles and surface material. In addition, we will present predictions for biosignature destruction at different geographical locations and burial depths and discuss the implications of these results for surface sampling by future missions to Europa's surface.

  10. Radiative corrections for the direct detection of neutralino dark matter and its relic density

    Energy Technology Data Exchange (ETDEWEB)

    Steppeler, Patrick Norbert

    2016-07-01

    In this thesis we calculate supersymmetric one-loop corrections of the strong interaction to elastic neutralino-nucleon scattering. The calculation is described in detail and performed in full generality within the Minimal Supersymmetric Standard Model (MSSM). In order to benefit from the well-established tensor reduction method, we have to stabilise the latter for vanishing Gram determinants. Afterwards the radiative corrections are matched onto an effective field theory based on the scalar operator anti χχ anti qq and the axial-vector operator anti χγ{sub 5}γ{sub μ}χ anti qγ{sub 5}γ{sup μ}q. This matching procedure is performed at the high scale μ{sub high}∝1000 GeV, whereas the associated nuclear matrix elements are defined at the low scale μ{sub low}∝5 GeV. To link both scales, the running of the effective operators and their corresponding Wilson coefficients is taken into account via renormalisation group equations. The lightest neutralino can be considered as a canonical example for a weakly interacting, massive particle which could constitute dark matter. To verify the existence of such particles, so-called direct detection experiments are conducted currently. These are based on the interaction between dark matter and nucleons. The leading contributions to the spin-independent and spin-dependent neutralino-nucleon cross sections are governed by the effective operators mentioned above, respectively. The calculation of the associated radiative corrections corresponds to a reduction of the theoretical uncertainty and permits to identify neutralino properties more reliably in case of positive findings and to set more robust exclusion bounds in case of negative findings. Furthermore, we calculate radiative corrections to annihilation and coannihilation processes of gauginos into quarks, where we focus again on supersymmetric one-loop corrections of the strong interaction. These processes contribute dominantly to the (co)annihilation cross section

  11. Quantum Computation with Ultrafast Laser Pulse Shaping

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 6. Quantum Computation with Ultrafast Laser Pulse Shaping. Debabrata Goswami. General Article Volume 10 Issue 6 June 2005 pp 8-14. Fulltext. Click here to view fulltext PDF. Permanent link:

  12. Ultrafast spectroscopy of model biological membranes

    NARCIS (Netherlands)

    Ghosh, Avishek

    2009-01-01

    In this PhD thesis, I have described the novel time-resolved sum-frequency generation (TR-SFG) spectroscopic technique that I developed during the course of my PhD research and used it study the ultrafast vibrational, structural and orientational dynamics of water molecules at model biological

  13. Photonic-assisted ultrafast THz wireless access

    DEFF Research Database (Denmark)

    Yu, Xianbin; Chen, Ying; Galili, Michael

    THz technology has been considered feasible for ultrafast wireless data communi- cation, to meet the increasing demand on next-generation fast wireless access, e.g., huge data file transferring and fast mobile data stream access. This talk reviews recent progress in high-speed THz wireless...

  14. Open-Source Radiation Exposure Extraction Engine (RE3) with Patient-Specific Outlier Detection.

    Science.gov (United States)

    Weisenthal, Samuel J; Folio, Les; Kovacs, William; Seff, Ari; Derderian, Vana; Summers, Ronald M; Yao, Jianhua

    2016-08-01

    We present an open-source, picture archiving and communication system (PACS)-integrated radiation exposure extraction engine (RE3) that provides study-, series-, and slice-specific data for automated monitoring of computed tomography (CT) radiation exposure. RE3 was built using open-source components and seamlessly integrates with the PACS. RE3 calculations of dose length product (DLP) from the Digital imaging and communications in medicine (DICOM) headers showed high agreement (R (2) = 0.99) with the vendor dose pages. For study-specific outlier detection, RE3 constructs robust, automatically updating multivariable regression models to predict DLP in the context of patient gender and age, scan length, water-equivalent diameter (D w), and scanned body volume (SBV). As proof of concept, the model was trained on 811 CT chest, abdomen + pelvis (CAP) exams and 29 outliers were detected. The continuous variables used in the outlier detection model were scan length (R (2)  = 0.45), D w (R (2) = 0.70), SBV (R (2) = 0.80), and age (R (2) = 0.01). The categorical variables were gender (male average 1182.7 ± 26.3 and female 1047.1 ± 26.9 mGy cm) and pediatric status (pediatric average 710.7 ± 73.6 mGy cm and adult 1134.5 ± 19.3 mGy cm).

  15. Results of conservative surgery and radiation for mammographically detected ductal carcinoma in situ (DCIS)

    International Nuclear Information System (INIS)

    Fowble, B.; Hanlon, A.L.; Fein, D.A.; Hoffman, J.P.; Sigurdson, E.R.; Patchefsky, A.; Kessler, H.

    1996-01-01

    Purpose: The role of conservative surgery and radiation for mammographically detected DCIS is controversial. In particular, there is a paucity of data for outcome with radiation in a group of patients comparable to those treated with local excision and surveillance (mammographically detected DCIS ≤2.5 cm, negative resection margins, negative post-biopsy mammogram). The purpose of this study is to report long term outcome of conservative surgery and radiation for mammographically detected DCIS with emphasis on the results in patients (pts.) considered candidates for excision alone. Materials and Methods: From 1983 to 1992, 110 women with mammographically detected DCIS (calcifications 72%, mass ± calcifications 27%) and no prior history of breast cancer underwent needle localization biopsy followed by radiation. The median age of the patient population was 56 yrs. (range 37-81). The median followup was 5.3 yrs. (range .5-12). Re-excision was performed in 55%. Final margins of resection were negative in 62%, positive 7%, close 11%, and unknown 20%. Axillary dissection was performed in 31 pts. and all had negative nodes. 31% had a positive family history of breast cancer (1 affected relative-25 pts., two-7 pts., three-2 pts.). The most common predominant histologic subtype was comedo (54%) followed by cribriform (22%). The median pathologic tumor size was 8 mm (range 2 mm to 5 cm). A post-biopsy mammogram prior to radiation was performed in 46% of the patients. Radiation consisted of treatment to the entire breast (median 5000 cGy) with a boost to the primary site (97%) of an additional 1000 cGy. The median total dose to the primary site was 6040 cGy (range 5000 to 6660). Results: Three patients developed a recurrence in the treated breast at 52, 106, and 107 months. All 3 recurrences were invasive ductal cancers and all were treated with mastectomy. The location of the recurrence was in the same quadrant as the primary in 1 pt. and in a separate quadrant in 2 pts

  16. Perspective: Ultrafast magnetism and THz spintronics

    Energy Technology Data Exchange (ETDEWEB)

    Walowski, Jakob; Münzenberg, Markus [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

    2016-10-14

    This year the discovery of femtosecond demagnetization by laser pulses is 20 years old. For the first time, this milestone work by Bigot and coworkers gave insight directly into the time scales of microscopic interactions that connect the spin and electron system. While intense discussions in the field were fueled by the complexity of the processes in the past, it now became evident that it is a puzzle of many different parts. Rather than providing an overview that has been presented in previous reviews on ultrafast processes in ferromagnets, this perspective will show that with our current depth of knowledge the first applications are developed: THz spintronics and all-optical spin manipulation are becoming more and more feasible. The aim of this perspective is to point out where we can connect the different puzzle pieces of understanding gathered over 20 years to develop novel applications. Based on many observations in a large number of experiments. Differences in the theoretical models arise from the localized and delocalized nature of ferromagnetism. Transport effects are intrinsically non-local in spintronic devices and at interfaces. We review the need for multiscale modeling to address the processes starting from electronic excitation of the spin system on the picometer length scale and sub-femtosecond time scale, to spin wave generation, and towards the modeling of ultrafast phase transitions that altogether determine the response time of the ferromagnetic system. Today, our current understanding gives rise to the first usage of ultrafast spin physics for ultrafast magnetism control: THz spintronic devices. This makes the field of ultrafast spin-dynamics an emerging topic open for many researchers right now.

  17. Perspective: Ultrafast magnetism and THz spintronics

    International Nuclear Information System (INIS)

    Walowski, Jakob; Münzenberg, Markus

    2016-01-01

    This year the discovery of femtosecond demagnetization by laser pulses is 20 years old. For the first time, this milestone work by Bigot and coworkers gave insight directly into the time scales of microscopic interactions that connect the spin and electron system. While intense discussions in the field were fueled by the complexity of the processes in the past, it now became evident that it is a puzzle of many different parts. Rather than providing an overview that has been presented in previous reviews on ultrafast processes in ferromagnets, this perspective will show that with our current depth of knowledge the first applications are developed: THz spintronics and all-optical spin manipulation are becoming more and more feasible. The aim of this perspective is to point out where we can connect the different puzzle pieces of understanding gathered over 20 years to develop novel applications. Based on many observations in a large number of experiments. Differences in the theoretical models arise from the localized and delocalized nature of ferromagnetism. Transport effects are intrinsically non-local in spintronic devices and at interfaces. We review the need for multiscale modeling to address the processes starting from electronic excitation of the spin system on the picometer length scale and sub-femtosecond time scale, to spin wave generation, and towards the modeling of ultrafast phase transitions that altogether determine the response time of the ferromagnetic system. Today, our current understanding gives rise to the first usage of ultrafast spin physics for ultrafast magnetism control: THz spintronic devices. This makes the field of ultrafast spin-dynamics an emerging topic open for many researchers right now.

  18. Impact of precursor purity on optical properties and radiation detection of CsI:Tl scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Saengkaew, Phannee; Cheewajaroen, Kulthawat; Yenchai, Chadet; Thong-aram, Decho [Chulalongkorn University, Department of Nuclear Engineering, Faculty of Engineering, Bangkok (Thailand); Sanorpim, Sakuntam [Chulalongkorn University, Department of Physics, Faculty of Science, Bangkok (Thailand); Jitpukdee, Manit [Kasetsart University, Department of Applied Radiation and Isotope, Faculty of Science, Bangkok (Thailand); Yordsri, Visittapong; Thanachayanont, Chanchana [Ministry of Science and Technology, National Metal and Materials Technology Center, National Science and Technology Development Agency, Pathumthani (Thailand); Nuntawong, Noppadon [Ministry of Science and Technology, National Electronic and Computer Technology Center, National Science and Technology Development Agency, Pathumthani (Thailand)

    2016-08-15

    Cesium iodide doped with thallium (CsI:Tl) crystals was grown to develop the gamma-ray detectors by using low-cost raw materials. Effect of impurities on optical properties and radiation detection performance was investigated. By a modified homemade Bridgman-Stockbarger technique, CsI:Tl samples were grown in two levels of CsI and TlI reactant materials, i.e., having as a very high purity of 99.999 % and a high purity of 99.9 %. XRD measurements indicate CsI:Tl crystals having a good quality with a dominant (110) plane. Having a cubic structure, a lattice constant of CsI crystals of 0.4574 nm and a crystallite size of 43.539 nm were obtained. From the lower-purity raw materials, calcite was found in an orange crystal with a lattice constant of 0.4560 nm and a crystallite size of 43.089 nm. By PL measurements, the optical properties of the CsI:Tl crystals were analyzed. ∝540-nm-wavelength PL peak was observed from the colorless high-purity crystal, and ∝600-nm-wavelength PL peak was observed from the orange crystal. The brighter PL emission was obtained from the orange crystals suggesting impurities. CsI:Tl surface morphology by SEM exhibited a smooth surface with some parallel crystal facets. For electrical properties of high-quality CsI:Tl crystals, the electrical resistances were 230 ± 16 MΩ in cross-sectional direction and 714 ± 136 MΩ in vertical direction with respect to more homogeneous crystal quality in cross-sectional direction than that in vertical direction. TEM measurement was applied to evaluate the microstructure of colorless CsI:Tl crystal with different patterns of a cubic structure. Both CsI:Tl crystals show good efficiencies and good resolutions. Maintaining the same electronic conditions and amplifications, the colorless CsI:Tl scintillators represented a higher detection efficiency at 122 keV of Co-57 of 78.4 % and the energy resolution of 23.3 % compared to the detection efficiency of 75.9 % and the energy resolution of 34.6 % of the

  19. Prospects of detecting gravitational background radiation by Doppler tracking interplanetary spacecraft

    International Nuclear Information System (INIS)

    Bertotti, B.; Carr, B.J.

    1980-01-01

    We examine the theoretical and experimental prospects of detecting a low-frequency, continuous, stochastic background of gravitational waves by Doppler tracking interplanetary spacecraft. From a theoretical standpoint, such a background may have been generated by various postgalactic processes or by pregalactic black hole formation; there could also exist a primordial background which goes back to the beginning of the universe. We review the characteristic frequency and density ranges which one might anticipate for these backgrounds. From an experimental standpoint, one's ability to detect a background is limited by the finite length of the record available and by an imperfect knowledge of the spectrum of various sources of noise. The fundamental contribution to the noise comes from the clock which regulates the frequency of the tracking waves. If one uses a hydrogen maser clock, this noise becomes progressively less important with decreasing frequency: one might hope to detect a critical density of background radiation at frequencies below 10 -2 Hz and a background with 10 -4 times the critical density at frequencies below 10 -5 Hz. It is encouraging that some of the sorts of background which we anticipate from theoretical considerations fall within the observable regime. We discuss the extent to which other sources of noise may exceed the clock noise and the degree to which they can be eliminated

  20. Evaluation of phase sensitive detection method and Si avalanche photodiode for radiation thermometry

    International Nuclear Information System (INIS)

    Hobbs, M J; Tan, C H; Willmott, J R

    2013-01-01

    We report the evaluation of Si avalanche photodiodes (APDs) for use in radiation thermometry as an alternative to Si photodiodes. We compared their performance when operated under phase sensitive detection (PSD), where the signal is modulated, and direct detection (DD) methods. A Si APD was compared with a Si photodiode with reference black body temperatures of 275 to 600°C, in terms of the mean output voltage and signal-to-noise ratio (SNR), measured at different APD gain values. We found that using both PSD and DD methods, the high internal gain of the Si APD achieved a lower minimum detection temperature in order to satisfy a specific minimum output voltage of the detector-preamplifier combination employed. The use of PSD over DD for the Si APD allowed for improved performance of the thermometer, with a lower minimum measurable temperature, as well as improvement in the SNR. For instance we found that at 350°C, the Si APD biased at 150 V using PSD can provide ∼ 88 times enhancement in the system SNR over that of a Si photodiode using DD. A corresponding temperature error of ±0.05°C was achieved using the APD with PSD compared to an error of ±2.75°C measured using the Si photodiode with DD.

  1. Detection limits of absorbed dose of ionizing radiation in molluscan shells as determined by e.p.r. spectroscopy

    International Nuclear Information System (INIS)

    Stachowicz, W.; Michalik, J.; Burlinska, G.; Sadlo, J.; Dziedzic-Goclawska, A.; Ostrowski, K.

    1995-01-01

    The exposure of waters to ionizing radiation from radionuclides imprisoned in dumped nuclear waste containers, freed in nuclear submarine accidents or released in underwater magma eruptions are difficult to be evaluated by conventional radiometric methods. Ionizing radiation evokes stable paramagnetic centers in crystalline lattice of mineral components in bone skeletons of mammals and fishes as well as in exoskeletons of mollusca. They give rise in e.p.r. to specific, extremely stable signals which are proposed to be applied as indicators of radiation exposure levels. In the present study the e.p.r. detection limits of the dose of ionizing radiation absorbed in shells of fresh water and marine mollusca (selected species) have been estimated. It has been found that with fresh water mollusca the dose of 1-2 Gy can be detected, while the sea water mollusca by one order of magnitude lower, i.e. about 0.1 Gy. (author)

  2. Study of material properties important for an optical property modulation-based radiation detection method for positron emission tomography

    OpenAIRE

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2017-01-01

    We compare the performance of two detector materials, cadmium telluride (CdTe) and bismuth silicon oxide (BSO), for optical property modulation-based radiation detection method for positron emission tomography (PET), which is a potential new direction to dramatically improve the annihilation photon pair coincidence time resolution. We have shown that the induced current flow in the detector crystal resulting from ionizing radiation determines the strength of optical modulation signal. A large...

  3. Dynamic CT for Parathyroid Adenoma Detection: How Does Radiation Dose Compare With Nuclear Medicine?

    Science.gov (United States)

    Czarnecki, Caroline A; Einsiedel, Paul F; Phal, Pramit M; Miller, Julie A; Lichtenstein, Meir; Stella, Damien L

    2018-05-01

    Dynamic CT is increasingly used for preoperative localization of parathyroid adenomas, but concerns remain about the radiation effective dose of CT compared with that of 99m Tc-sestamibi scintigraphy. The purpose of this study was to compare the radiation dose delivered by three-phase dynamic CT with that delivered by 99m Tc-sestamibi SPECT/CT performed in accordance with our current protocols and to assess the possible reduction in effective dose achieved by decreasing the scan length (i.e., z-axis) of two phases of the dynamic CT protocol. The effective dose of a 99m Tc-sestamibi nuclear medicine parathyroid study performed with and without coregistration CT was calculated and compared with the effective dose of our current three-phase dynamic CT protocol as well as a proposed protocol involving CT with reduced scan length. The median effective dose for a 99m Tc-sestamibi nuclear medicine study was 5.6 mSv. This increased to 12.4 mSv with the addition of coregistration CT, which is higher than the median effective dose of 9.3 mSv associated with the dynamic CT protocol. Reducing the scan length of two phases in the dynamic CT protocol could reduce the median effective dose to 6.1 mSv, which would be similar to that of the dose from the 99m Tc-sestamibi study alone. Dynamic CT used for the detection of parathyroid adenoma can deliver a lower radiation dose than 99m Tc-sestamibi SPECT/CT. It may be possible to reduce the dose further by decreasing the scan length of two of the phases, although whether this has an impact on accuracy of the localization needs further investigation.

  4. Detection of Radiation-Exposure Biomarkers by Differential Mobility Prefiltered Mass Spectrometry (DMS-MS).

    Science.gov (United States)

    Coy, Stephen L; Krylov, Evgeny V; Schneider, Bradley B; Covey, Thomas R; Brenner, David J; Tyburski, John B; Patterson, Andrew D; Krausz, Kris W; Fornace, Albert J; Nazarov, Erkinjon G

    2010-04-15

    Technology to enable rapid screening for radiation exposure has been identified as an important need, and, as a part of a NIH / NIAD effort in this direction, metabolomic biomarkers for radiation exposure have been identified in a recent series of papers. To reduce the time necessary to detect and measure these biomarkers, differential mobility spectrometry - mass spectrometry (DMS-MS) systems have been developed and tested. Differential mobility ion filters preselect specific ions and also suppress chemical noise created in typical atmospheric-pressure ionization sources (ESI, MALDI, and others). Differential-mobility-based ion selection is based on the field dependence of ion mobility, which, in turn, depends on ion characteristics that include conformation, charge distribution, molecular polarizability, and other properties, and on the transport gas composition which can be modified to enhance resolution. DMS-MS is able to resolve small-molecule biomarkers from nearly-isobaric interferences, and suppresses chemical noise generated in the ion source and in the mass spectrometer, improving selectivity and quantitative accuracy. Our planar DMS design is rapid, operating in a few milliseconds, and analyzes ions before fragmentation. Depending on MS inlet conditions, DMS-selected ions can be dissociated in the MS inlet expansion, before mass analysis, providing a capability similar to MS/MS with simpler instrumentation. This report presents selected DMS-MS experimental results, including resolution of complex test mixtures of isobaric compounds, separation of charge states, separation of isobaric biomarkers (citrate and isocitrate), and separation of nearly-isobaric biomarker anions in direct analysis of a bio-fluid sample from the radiation-treated group of a mouse-model study. These uses of DMS combined with moderate resolution MS instrumentation indicate the feasibility of field-deployable instrumentation for biomarker evaluation.

  5. A rapid and simple screening test to detect the radiation treatment of fat-containing foods

    International Nuclear Information System (INIS)

    Delincee, H.

    1993-01-01

    In recent years several international efforts have been made to develop analytical detection methods for the radiation treatment of foods. A number of methods has indeed been developed. Particularly, for fat-containing foods several methods are already in an advanced stage. In addition to the sophisticated techniques such as gas chromatography/mass spectrometry which require relatively expensive equipment and/or extended sample preparation time, it would be desirable to have quick and simple screening tests, which immediately on-the-spot give some indication whether a food product has been irradiated or not. A solution to this problem for lipid-containing foods has been put forward by Furuta and co-workers (1991, 1992), who estimated the amount of carbon monoxide originating from the lipid fraction in poultry meat after irradiation. The carbon monoxide was expelled from the frozen meat by quick microwave heating and in the head space of the sample, the formed carbon monoxide was determined by gas chromatography. In order to speed up time of analysis, we have used an electrochemical CO sensor, as also is being used to estimate CO in ambient air in workplaces, to determine the CO content in the vapor expelled from the irradiated samples. This CO test is very simple, cheap and easy to perform. It takes only a few minutes to screen food samples for evidence of their having been radiation processed. If doubts concerning the radiation treatment of a sample arise, the more sophisticated - and expensive -methods for analyzing lipid-containing foods can be applied. Certainly the test is limited to food products which contain a certain amount of fat. A preliminary test with lean shrimps showed practically no difference between irradiated (2.5 and 5 kGy) and non-irradiated samples. By relating CO production to the fat content, possibly a better parameter for classification can be obtained. (orig./vhe)

  6. Instrumentation For Multiple Radiation Detection Based On Novel Mercurous Halides For Nuclear Planetology, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Radiation detectors that sense gamma and neutron radiation are critical to the exploration of planetary surface composition. Among the key technological challenges...

  7. Position sensitive detection of nuclear radiation mediated by non equilibrium phonons at low temperatures

    Science.gov (United States)

    Pröbst, F.; Peterreins, Th.; Feilitzsch, F. v.; Kraus, H.

    1990-03-01

    Many experiments in nuclear and particle physics would benefit from the development of a device capable of detecting non-ionizing events with a low energy threshold. In this context, we report on experimental tests of a detector based on the registration of nonequilibrium phonons. The device is composed of a silicon single crystal (size: 20×10×3 mm 3) and of an array of superconducting tunnel junctions evaporated onto the surface of the crystal. The junctions serve as sensors for phonons created by absorption of nuclear radiation in the crystal. We show how pulse height analysis and the investigation of time differences between correlated pulses in different junctions can be used to obtain information about the point of absorption.

  8. Attempt to detection of laser radiation effect on the neutron interaction with 139La nuclei

    International Nuclear Information System (INIS)

    Vertebnyj, V.P.; Razbudej, V.F.; Sidorov, S.V.; Muravitskij, A.V.; Vorona, P.N.

    1982-01-01

    Phenomenon predicted theoretically was attempted to discover at the WWR-M nuclear reactor. Transmission of a 139 La sample in the radiation field of a CO 2 laser was measured with a neutron spectrometer by means of the time-of-flight method. No satellite resonances near the 0.734 eV resonance, expected according to the Zaretsky-Lomonosov theory, were detected. Causes of disagreement between experiment and theory are not clear yet. The following possible causes can be suggested: 1) neutron resonance at 0.734 eV energy is not p resonance in fact; 2) atom electron shells screen nuclei and considerably weaken external electric field; 3) R=1.2xAsup(1/3)=6.216 and R'=4.9 fermi used values are not exact. Really the value (R-R') can be much less

  9. Formation of hydrocarbons in irradiated Brazilian beans: gas chromatographic analysis to detect radiation processing

    International Nuclear Information System (INIS)

    Villavicencio, A.L.C.H.; Mancini-Filho, J.; Hartmann, M.; Ammon, J.; Delincee, H.

    1997-01-01

    Radiation processing of beans, which are a major source of dietary protein in Brazil, is a valuable alternative to chemical fumigation to combat postharvest losses due to insect infestation. To ensure free consumer choice, irradiated food will be labeled as such, and to enforce labeling, analytical methods to detect the irradiation treatment in the food product itself are desirable. In two varieties of Brazilian beans, Carioca and Macacar beans, the radiolytic formation of hydrocarbons formed after alpha and beta cleavage, with regard to the carbonyl group in triglycerides, have been studied. Using gas chromatographic analysis of these radiolytic hydrocarbons, different yields per precursor fatty acid are observed for the two types of beans. However, the typical degradation pattern allows the identification of the irradiation treatment in both bean varieties, even after 6 months of storage

  10. HgI2 nanostructures obtained hydrothermally for application in ionizing radiation detection

    International Nuclear Information System (INIS)

    Pérez Barthaburu, María; Bentos Pereira, Heinkel; Fornaro, Laura; Galain, Isabel; Aguiar, Ivana

    2016-01-01

    The compound semiconductor HgI 2 has been widely studied and employed as a material for ionizing radiation detection. Monocrystal growth is an intricate method for obtaining materials for this application. With the aim of finding a simpler and more effective way to develop ionizing radiation detectors, we employed HgI 2 nanostructures subjected to a hydrothermal treatment and then pressed for this purpose. In the synthesis procedure, aqueous solutions of Hg(NO 3 ) 2 and NaI were mixed until their reaction completed and the suspension obtained was then placed in a homemade autoclave and heated at 120 °C for 2, 10 or 24 h. We confirmed the HgI 2 tetragonal phase by powder XRD in all cases, independently of the synthesis conditions employed. Nanoparticles were characterized by their size and morphology by TEM. We used the HgI 2 nanostructures to obtain a pellet by applying 0.7 GPa of pressure at room temperature. The pellet was then used to construct the detector, and we studied the electrical properties of the detector and its response to 241 Am sources of different exposure rates. The resistivity and signal-to-noise ratio obtained are of the order of those reported for HgI 2 detectors assembled with monocrystals. The results obtained in this work encourage us to work further on this topic, improving the method, scaling the detector’s size and studying its spectrometric grade. (paper)

  11. Development of new photon detection device for Cherenkov and fluorescence radiation

    Directory of Open Access Journals (Sweden)

    Tinti A.

    2013-06-01

    Full Text Available Recent progress on the development of a new solid state detector allowed the use of finely pixelled photocathodes obtained from silicon semiconductors. SiPM detectors seem to be an ideal tool for the detection of Cherenkov and fluorescence light in spite of their not yet resolved criticism for operating temperature and intrinsic noise. The main disadvantage of SiPM in this case is the poor sensitivity in the wavelength range 300-400 nm, where the Cherenkov light and fluorescence radiation are generated. We report on the possibility to realize a new kind of pixelled photodetector based on the use of silicon substrate with carbon nanotube compounds, more sensitive to the near UV radiation. Also if at the very beginning, the development of such detector appears very promising and useful for astroparticle physics, both in the ground based arrays and in the space experiments. The detectors are ready to be operated in conditions of measurements without signal amplification.

  12. Thermoluminescence of contaminating minerals for the detection of radiation treatment of dried fruits

    International Nuclear Information System (INIS)

    Khan, H.M.; Bhatti, Ijaz A.; Delincee, Henry

    2002-01-01

    Several types of dry fruits (pistachio nut, dried apricot, almond and raisins) have been investigated for detection of their radiation treatment by gamma rays or electron beam using thermoluminescence (TL) measurements. These samples were irradiated to 1.0-3.0 kGy (gamma rays) or 0.75-3.9 kGy (10 MeV electron beam). Thermoluminescence glow curves for the contaminating minerals separated from the dry fruits were recorded between the temperature range of 50 deg. C and 500 deg. C. In all the cases, the intensity of TL signal for the irradiated dry fruits was 1-3 orders of magnitudes higher than the TL intensity of the corresponding unirradiated control samples allowing clear distinction between the irradiated and unirradiated samples. These results were normalized by re-irradiating the mineral grains with a gamma-ray dose of 1.0 kGy, and a second glow curve was recorded. The ratio of intensity of the first glow curve (TL 1 ) to that after the normalization dose (TL 2 ), i.e. (TL 1 /TL 2 ) was determined and compared with the recommended threshold values. These parameters, together with comparison of the shape of the first glow curve, gave unequivocal results about the radiation treatment of the dry fruit samples

  13. Thermoluminescence of contaminating minerals for the detection of radiation treatment of dried fruits

    Energy Technology Data Exchange (ETDEWEB)

    Khan, H M; Bhatti, Ijaz A; Delincee, Henry

    2002-03-01

    Several types of dry fruits (pistachio nut, dried apricot, almond and raisins) have been investigated for detection of their radiation treatment by gamma rays or electron beam using thermoluminescence (TL) measurements. These samples were irradiated to 1.0-3.0 kGy (gamma rays) or 0.75-3.9 kGy (10 MeV electron beam). Thermoluminescence glow curves for the contaminating minerals separated from the dry fruits were recorded between the temperature range of 50 deg. C and 500 deg. C. In all the cases, the intensity of TL signal for the irradiated dry fruits was 1-3 orders of magnitudes higher than the TL intensity of the corresponding unirradiated control samples allowing clear distinction between the irradiated and unirradiated samples. These results were normalized by re-irradiating the mineral grains with a gamma-ray dose of 1.0 kGy, and a second glow curve was recorded. The ratio of intensity of the first glow curve (TL{sub 1}) to that after the normalization dose (TL{sub 2}), i.e. (TL{sub 1}/TL{sub 2}) was determined and compared with the recommended threshold values. These parameters, together with comparison of the shape of the first glow curve, gave unequivocal results about the radiation treatment of the dry fruit samples.

  14. Thyroid scintigraphy for the detection of radiation-induced thyroid cancer

    International Nuclear Information System (INIS)

    Puylaert, J.B.; Pauwels, E.K.; Goslings, B.M.; Van Daal, W.A.

    1985-01-01

    Thyroid scintigraphy with Tc-99m pertechnetate was performed in 249 patients who received radiation therapy for abnormalities in the head or neck in order to determine the role of this examination in the detection of abnormal nodules arising from cancer. These patients received a mean total dose of about 10.1 Gy. The mean follow-up period was 39 years. All patients underwent physical examination without prior knowledge of the scintigram. Scintigrams were evaluated without prior knowledge of the physical examination. In 158 cases, both the physical examination and scintigraphy were negative. In 64 cases, both examinations were positive. In ten patients, the physical examination was positive and scintigraphy was negative and vice versa in 17 patients. Of 249 patients, 28 ultimately underwent thyroid surgery; a total of four had carcinoma. A cost-benefit relationship as to routine scintigraphy as a screening procedure is presented. If patients are first screened by palpation, a number of abnormal nodules will be missed. In addition, a considerable number with positive palpation would probably undergo surgery unnecessarily. From a clinical and financial point of view, it is believed that scintigraphy is the examination of choice for screening for radiation-induced thyroid malignancies

  15. The SOS chromotest: bacterial cells to detect and characterize genotoxic products and radiations

    International Nuclear Information System (INIS)

    Quillardet, P.; Hofnung, M.

    1994-01-01

    The advanced knowledge we have on the bacterium Escherichia coli has facilitated the development of the colorimetric and fast assay, the SOS chromotest, which involves a single tester strain and gives a qualitative and a quantitative assay of the action of a genotoxic agent. We discuss a number of possibilities opened by this test in order to make a genetic diagnosis of the chemical nature of the damages caused in the genetic material by means of a battery of strains which have been genetically modified for that purpose. In order to give an idea of the accuracy of the bacterial responses and of the way they can be used to characterize the DNA damage by a genetic approach, the case of alkylating agents is described in a relatively detailed fashion, and the case of oxidative agents is rapidly mentioned. The sensitivity to ionizing radiation is such that the test is able to detect doses of the order of 1 Gy. We discuss briefly how it could be possible to increase this sensitivity by genetically inactivating repair systems which process the injuries caused by these agents, and how the use of a battery of tester strains could also give information on the nature of injuries caused by various types of ionizing radiation. (authors). 39 refs. 4 figs. 1 tab

  16. First Satellite-detected Perturbations of Outgoing Longwave Radiation Associated with Blowing Snow Events over Antarctica

    Science.gov (United States)

    Yang, Yuekui; Palm, Stephen P.; Marshak, Alexander; Wu, Dong L.; Yu, Hongbin; Fu, Qiang

    2014-01-01

    We present the first satellite-detected perturbations of the outgoing longwave radiation (OLR) associated with blowing snow events over the Antarctic ice sheet using data from Cloud-Aerosol Lidar with Orthogonal Polarization and Clouds and the Earth's Radiant Energy System. Significant cloud-free OLR differences are observed between the clear and blowing snow sky, with the sign andmagnitude depending on season and time of the day. During nighttime, OLRs are usually larger when blowing snow is present; the average difference in OLRs between without and with blowing snow over the East Antarctic Ice Sheet is about 5.2 W/m2 for the winter months of 2009. During daytime, in contrast, the OLR perturbation is usually smaller or even has the opposite sign. The observed seasonal variations and day-night differences in the OLR perturbation are consistent with theoretical calculations of the influence of blowing snow on OLR. Detailed atmospheric profiles are needed to quantify the radiative effect of blowing snow from the satellite observations.

  17. X-ray spectral determination by detection of radiation scattered at different angles

    International Nuclear Information System (INIS)

    Barrea, Raul; Mainardi, R.T.

    1987-01-01

    A precise knowledge of the spectral content of an X-ray beam is of fundamental importance in areas such as X-ray fluorescence analysis by absolute methods, radiodiagnosis, radiotherapy, computed tomography, etc. A simple practical method was developed to determine X-ray spectra emitted by X-ray tubes. It is based on the scattering of the beam on a solid target and detection of this radiation at different angles. This methodology can easily be adapted to the successive attenuation of the beam procedure. Numerical parameter values of a proposed analytical function for the energy spectrum are found measuring the radiation intensity with a suitable detector (ionization chamber or plastic scintillation detector) and equating it with the convolution integral of the proposed spectrum with the incoherent scattering function. This procedure of spectra determination is enclosed in the same group of those generically referred as successive modifications of the irradiation set up used in absolute methods of X-ray fluorescence analysis. (Author) [es

  18. Detection of some irradiated spices on the basis of radiation induced damage of starch

    International Nuclear Information System (INIS)

    Farkas, J.; Sharif, M.M.; Koncz, A.

    1990-01-01

    Untreated and irradiated samples of spices were suspended in water, alkalized, and after heat-gelatinization, the apparent viscosity was determined by a rotational viscometer. Several spices, i.e. white pepper, black pepper, nutmeg and ginger showed considerable loss of viscosity as a function of γ radiation dose in the dose range required for microbial decontamination of natural spices. Less promising results were obtained with spices such as allspice, garlic powder, and onion powder forming low-viscosity heat-treated suspensions even when unirradiated viscometric studies were also performed with a number of pepper samples of various origin to estimate the ''natural'' variation of rheological properties. Irradiation and storage studies were performed with ground black pepper samples of moisture contents in equilibrium with air of 25%, 50% and 75% R.H., respectively, either untreated or irradiated with 4, 8, 16 or 32 kGy, to study the effect of equilibrium relative humidity and storage time on detectability of radiation treatment. During the entire storage period of 100 days, statistically significant differences of the apparent viscosities of heat-gelatinized suspensions remained detectable between untreated samples and those irradiated with 8 kGy or higher doses. The apparent viscosity of high-moisture (75% E.R.H.) untreated samples was decreasing during long-term storage. Differences between viscosities of untreated and irradiated samples were enlarged when measured at elevated temperatures such as 50 0 C in the rotational viscometer, or in the boiling-water bath of a falling number apparatus. Other analytical indices such as onset and peak temperatures of gelatinization endotherms by DSC (damaged starch content), by colorimetry, reducing sugar content, alcohol-induced turbidity of hot water extracts of pepper samples, have been changed less dramatically by irradiation than the apparent viscosity of the gelatinized suspensions. (author)

  19. The DNA comet assay and the germination test in detection of food treated by ionizing radiation

    International Nuclear Information System (INIS)

    Huachaca, Nelida Simona Marin

    2002-01-01

    Two methods of irradiated food detection, one biochemical, the comet assay and, other biological, the germination test, were applied in bovine meat and fruit samples. The comet assay detects the damage on DNA caused by ionizing radiation. The germination test evaluates the sensitivity to radiation of seeds as for germination ability, shooting and, rooting. The samples were irradiated in gamma font and electron accelerator. For bovine meat samples, the doses were 0.0; 2.5; 4.5 e 7.0 kGy at chilled condition and, 0.0; 2.5; 4.5; 7.0 e 8.5 kGy at frozen conditions. For fruit samples such as melon, watermelon, apple, orange, papaya and, tomato, the doses were: 0.0; 0.5; 0.75; 1.0; 2.0 e 4.0 kGy. The differences between the gamma rays and the electron beam effects on extent of DNA migration and, on shooting and rooting, showed to be similar. The comet assay, under neutral conditions, permitted to discriminate between irradiated and unirradiated bovine meat samples, until one month of storage. Also, it was possible to distinguish, by the comet assay, the control sample with regard to irradiated fruit, at doses as low as 0,5 kGy. In the germination test, the root length was the best parameter to discriminate irradiated and unirradiated samples of melon, watermelon and tomato, while the germination percent was the best parameter for apple and orange. (author)

  20. Ultrafast Time-Resolved Photoluminescence Studies of Gallium-Arsenide

    Science.gov (United States)

    Johnson, Matthew Bruce

    This thesis concerns the study of ultrafast phenomena in GaAs using time-resolved photoluminescence (PL). The thesis consists of five chapters. Chapter one is an introduction, which discusses the study of ultrafast phenomena in semiconductors. Chapter two is a description of the colliding-pulse mode-locked (CPM) ring dye laser, which is at the heart of the experimental apparatus used in this thesis. Chapter three presents a detailed experimental and theoretical investigation of photoluminescence excitation correlation spectroscopy (PECS), the novel technique which is used to time-resolve ultrafast PL phenomena. Chapters 4 and 5 discuss two applications of the PECS technique. In Chapter 4 the variation of PL intensity in In-alloyed GaAs substrate material is studied, while Chapter 5 discusses the variation of carrier lifetimes in ion-damaged GaAs used in photo-conductive circuit elements (PCEs). PECS is a pulse-probe technique that measures the cross correlation of photo-excited carrier populations. The theoretical model employed in this thesis is based upon the rate equation for a simple three-level system consisting of valence and conduction bands and a single trap level. In the limit of radiative band-to-band dominated recombination, no PECS signal should be observed; while in the capture -dominated recombination limit, the PECS signal from the band-to-band PL measures the cross correlation of the excited electron and hole populations and thus, the electron and hole lifetimes. PECS is experimentally investigated using a case study of PL in semi-insulating (SI) GaAs and In -alloyed GaAs. At 77 K, the PECS signal is characteristic of a capture-dominated system, yielding an electron-hole lifetime of about 200 ps. However, at 5 K the behavior is more complicated and shows saturation effects due to the C acceptor level, which is un-ionized at 5 K. As a first application, PECS is used to investigate the large band-to-band PL contrast observed near dislocations in In

  1. Temporal behavior of hydrated electron studied up to 400 deg. C by ultrafast pulse radiolysis and Monte Carlo calculation

    International Nuclear Information System (INIS)

    Katsumura, Yosuke; Muroya, Yusa; Lin, Mingzhang; Yu, Yan; Mehran, Mostafavi; Sanguanmith, Sunuchakan; Meesungnoen, Jintana; Jay-Gerin, Jean-Paul

    2012-09-01

    Pulse radiolysis is a very powerful and unique method to observe the transient species and to determine their yields and has been widely used up to now. Since the radiation-induced reactions at elevated temperatures are accelerated, precise measurement becomes difficult by the conventional pulse radiolysis systems. Then, a higher time resolved pulse radiolysis system is highly expected. Recently, an ultrafast pulse radiolysis system has been developed in the University of Tokyo and applied to water radiolysis at elevated temperatures [1]. Temporal behavior of the hydrated electron at elevated temperatures up to 400 deg C has been detected. The time dependent behavior of hydrated electron at elevated temperatures were detected and the latest version of the Monte Carlo simulation code developed at University of Sherbrooke was applied to reproduce the experimental results. From the simulation, it was made clear that the thermalization distance becomes smaller with increasing temperature. In addition, in supercritical water, the initial yield is significantly dependent on density (pressure), which is consistent with our previous evaluation. (authors)

  2. Transient measurements with an ultrafast scanning tunneling microscope

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Jensen, Jacob Riis; Hvam, Jørn Märcher

    1998-01-01

    We use a photoconductively gated ultrafast scanning tunneling microscope to resolve laser-induced transients on transmission lines and photoconductors. The photoconductive switch on the tunneling probe is illuminated through a rigidly attached fiber. The use of the fiber enables us to scan across...... the transmission line while the change in delay time between pump beam (on the sample) and probe beam (on the probe) provides the temporal information. The investigated photoconductor sample is a low-temperature-grown GaAs layer placed on a sapphire substrate with a thin, semitransparent gold layer. In tunneling...... mode the probe is sensitive to laser-induced field changes in the semiconductor layer. Laser-induced transient signals of 2.2 ps widths are detected. As for the transmission lines, the signals can be explained by a capacitive coupling across the tunneling gap....

  3. Ultrafast quantum random number generation based on quantum phase fluctuations.

    Science.gov (United States)

    Xu, Feihu; Qi, Bing; Ma, Xiongfeng; Xu, He; Zheng, Haoxuan; Lo, Hoi-Kwong

    2012-05-21

    A quantum random number generator (QRNG) can generate true randomness by exploiting the fundamental indeterminism of quantum mechanics. Most approaches to QRNG employ single-photon detection technologies and are limited in speed. Here, we experimentally demonstrate an ultrafast QRNG at a rate over 6 Gbits/s based on the quantum phase fluctuations of a laser operating near threshold. Moreover, we consider a potential adversary who has partial knowledge on the raw data and discuss how one can rigorously remove such partial knowledge with postprocessing. We quantify the quantum randomness through min-entropy by modeling our system and employ two randomness extractors--Trevisan's extractor and Toeplitz-hashing--to distill the randomness, which is information-theoretically provable. The simplicity and high-speed of our experimental setup show the feasibility of a robust, low-cost, high-speed QRNG.

  4. Ultrafast probing of core hole localization in N2.

    Science.gov (United States)

    Schöffler, M S; Titze, J; Petridis, N; Jahnke, T; Cole, K; Schmidt, L Ph H; Czasch, A; Akoury, D; Jagutzki, O; Williams, J B; Cherepkov, N A; Semenov, S K; McCurdy, C W; Rescigno, T N; Cocke, C L; Osipov, T; Lee, S; Prior, M H; Belkacem, A; Landers, A L; Schmidt-Böcking, H; Weber, Th; Dörner, R

    2008-05-16

    Although valence electrons are clearly delocalized in molecular bonding frameworks, chemists and physicists have long debated the question of whether the core vacancy created in a homonuclear diatomic molecule by absorption of a single x-ray photon is localized on one atom or delocalized over both. We have been able to clarify this question with an experiment that uses Auger electron angular emission patterns from molecular nitrogen after inner-shell ionization as an ultrafast probe of hole localization. The experiment, along with the accompanying theory, shows that observation of symmetry breaking (localization) or preservation (delocalization) depends on how the quantum entangled Bell state created by Auger decay is detected by the measurement.

  5. Detection of reciprocal chromosome translocations as an indicator of organism exposure to ionizing radiation by FISH-WCP method

    International Nuclear Information System (INIS)

    Holeckova, B.; Sivikova, K.; Dianovsky, J.; Piesova, E.; Lakatosova, M.

    2006-01-01

    Chromosome translocations are considered to be the gold standard for assessing ionizing radiation exposure. Because translocations are inherently more stable through cell division than dicentrics, translocations have become the aberration of choice for evaluating many types of exposure. Fluorescence in situ hybridization with whole chromosome painting probes (FISH-WCP) has been shown to be a rapid method of detecting chromosomal rearrangements, and appears to be especially useful for analysis of induced translocations. The present paper shortly describes FISH-WCP method for detection of reciprocal translocations as indicators of exposure to ionizing radiation. (authors)

  6. Ultra-fast low-angle rapid acquisition and relaxation enhancement (UFLARE) in patients with epilepsy

    International Nuclear Information System (INIS)

    Eriksson, S.H.; Symms, M.R.; Woermann, F.G.; Kendall, B.; Stevens, J.M.; Stepney, A.; Barker, G.J.; Niendorf, T.

    2001-01-01

    MRI is an important diagnostic tool in patients with epilepsy, but patient motion during long scans may result in image artefacts. We studied the utility of an ultra-fast MR sequence in patients with epilepsy. Ultra-fast low-angle rapid acquisition and relaxation enhancement (UFLARE) images were acquired for 100 consecutive patients and nine control subjects. Scans were compared with routine T2-weighted spin echo images for signal-to-noise ratio, contrast, and conspicuity, followed by a blind review of lesion detectability. UFLARE scans were also acquired for 15 patients who moved during conventional scans. All UFLARE scans had lower signal-to-noise ratios and lower contrast than the T2-weighted images. Compared with T1- and T2-weighted, PD and FLAIR images, 86% of hippocampal sclerosis (HS), 92% of large but only 24% of small white-matter lesions were detected on the blind review of the UFLARE images. Reduced motion artefacts were seen on the UFLARE images in all 15 patients who moved during the conventional scans, and in three patients UFLARE was the only sequence we were able to obtain. Despite the lower lesion detectability for smaller lesions, the use of an ultra-fast MRI sequence such as UFLARE may be very useful in patients who are not able to co-operate during conventional MRI examinations, if a general anaesthetic is to be avoided. (orig.)

  7. Experimental applications for the MARK-1 and MARK-1A pulsed ionizing radiation detection systems. Volume 3

    International Nuclear Information System (INIS)

    Harker, Y.D.; Lawrence, R.S.; Yoon, W.Y.; Lones, J.L.

    1993-12-01

    This report is the third volume in a three volume set describing the MARK series of pulsed ionizing radiation detection systems. This volume describes the MARK-1A detection system, compares it with the MARK-1 system, and describes the experimental testing of the detection systems. Volume 1 of this set presents the technical specifications for the MARK-1 detection system. Volume 2 is an operations manual specifically for the MARK-1 system, but it generally applies to the MARK-1A system as well. These detection systems operate remotely and detect photon radiation from a single or a multiple pulsed source. They contain multiple detector (eight in the MARK-1 and ten in the MARK-1A) for determination of does and incident photon effective energy. The multiple detector arrangement, having different detector sizes and shield thicknesses, provides the capability of determining the effective photon energy of the radiation spectrum. Dose measurements using these units are consistent with TLD measurements. The detection range is from 3 nanorads to 90 microrads per source burst; the response is linear over that range. Three units were built and are ready for field deployment

  8. Detection of radiation induced lung injury in rats using dynamic hyperpolarized 129Xe magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Fox, Matthew S.; Ouriadov, Alexei; Hegarty, Elaine; Thind, Kundan; Wong, Eugene; Hope, Andrew; Santyr, Giles E.

    2014-01-01

    .6 ± 9.6 ms) that were not significantly different from baseline. Conclusions: Whole-lung tissue transfer time constants for 129 Xe (T Tr-tissue ) can be used to detect the early phase of RILI in a rat model involving 14 Gy thoracic 60 Co exposure as early as two weeks post-irradiation. This knowledge combined with more sophisticated models of gas exchange and imaging techniques, may allow functional lung avoidance radiation therapy planning to be achievable, providing more beneficial treatment plans and improved quality of life for recovering lung cancer patients

  9. Synthesis and characterization of lanthanide based nanomaterials for radiation detection and biomedical applications

    Science.gov (United States)

    Yao, Mingzhen

    2011-12-01

    Lanthanide based nanomaterials have shown a great potential in various areas such as luminescence imaging, luminescent labels, and detection of cellular functions. Due to the f-f transitions of the metal ion, luminescence of lanthanide ions is characterized by sharp and narrow emissions. In this dissertation lanthanide based nanoparticles such as Ce3+, Eu3+ and other lanthanide ions doped LaF3 were synthesized, their characterization, encapsulation and embedding into hybrid matrix were investigated and some of their biomedical and radiological applications were studied. DMSO is a common solvent which has been used widely for biological applications. LaF3:Ce nanoparticles were synthesized in DMSO and it was found that their fluorescent emission originates from the metal-to-ligand charge-transfer excited states. After conjugation with PpIX and then encapsulation within PLGA, the particles show efficient uptake by cancer cells and great cytotoxicity, which is promising for applications in cancer treatments. However, the emission of Eu3+ in DMSO is totally different from LaF3:Ce, very strong characteristic luminescence is observed but no emissions from metal-to-ligand charge-transfer excited states as observed in LaF3:Ce in DMSO. Besides, it is very interesting to see that the coupling of Eu 3+ with O-H oscillations after water was introduced has an opposite effect on emission peaks at 617 nm and its shoulder peak at 613 nm. As a result, the intensity ratio of these two emissions has a nearly perfect linear dependence on increasing water concentration in Eu-DMSO, which provides a very convenient and valuable method for water determination in DMSO. Ce3+ has been well known as an emitter for radiation detection due to its very short decay lifetime. However, its emission range limited the environment in which the detection system works. Whereas, Quantum dots have high luminescence quantum efficiency but their low stopping power results in very weak scintillation

  10. Enhanced plasma wave detection of terahertz radiation using multiple high electron-mobility transistors connected in series

    KAUST Repository

    Elkhatib, Tamer A.; Kachorovskiǐ, Valentin Yu; Stillman, William J.; Veksler, Dmitry B.; Salama, Khaled N.; Zhang, Xicheng; Shur, Michael S.

    2010-01-01

    We report on enhanced room-temperature detection of terahertz radiation by several connected field-effect transistors. For this enhanced nonresonant detection, we have designed, fabricated, and tested plasmonic structures consisting of multiple InGaAs/GaAs pseudomorphic high electron-mobility transistors connected in series. Results show a 1.63-THz response that is directly proportional to the number of detecting transistors biased by a direct drain current at the same gate-to-source bias voltages. The responsivity in the saturation regime was found to be 170 V/W with the noise equivalent power in the range of 10-7 W/Hz0.5. The experimental data are in agreement with the detection mechanism based on the rectification of overdamped plasma waves excited by terahertz radiation in the transistor channel. © 2010 IEEE.

  11. Enhanced plasma wave detection of terahertz radiation using multiple high electron-mobility transistors connected in series

    KAUST Repository

    Elkhatib, Tamer A.

    2010-02-01

    We report on enhanced room-temperature detection of terahertz radiation by several connected field-effect transistors. For this enhanced nonresonant detection, we have designed, fabricated, and tested plasmonic structures consisting of multiple InGaAs/GaAs pseudomorphic high electron-mobility transistors connected in series. Results show a 1.63-THz response that is directly proportional to the number of detecting transistors biased by a direct drain current at the same gate-to-source bias voltages. The responsivity in the saturation regime was found to be 170 V/W with the noise equivalent power in the range of 10-7 W/Hz0.5. The experimental data are in agreement with the detection mechanism based on the rectification of overdamped plasma waves excited by terahertz radiation in the transistor channel. © 2010 IEEE.

  12. Detection, characterization and measure of a new radiation-induced damage in isolated and cellular DNA

    International Nuclear Information System (INIS)

    Regulus, P.

    2006-10-01

    Deoxyribonucleic acid (DNA) contains the genetic information and chemical injury to this macromolecule may have severe biological consequences. We report here the detection of 4 new radiation-induced DNA lesions by using a high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) approach. For that purpose, the characteristic fragmentation of most 2'-deoxy-ribo nucleosides, the loss of 116 Da corresponding to the loss of the 2-deoxyribose moiety, was used in the so-called neutral loss mode of the HPLC-MS/MS. One of the newly detected lesions, named dCyd341 because it is a 2'-deoxycytidine modification exhibiting a molecular weight of 341 Da, was also detected in cellular DNA. Characterization of this modified nucleoside was performed using NMR and exact mass determination of the product obtained by chemical synthesis. A mechanism of formation was then proposed, in which the first event is the H-abstraction at the C4 position of a 2-deoxyribose moiety. Then, the sugar modification produced exhibits a reactive aldehyde that, through reaction with a vicinal cytosine base, gives rise to dCyd341. dCyd341 could be considered as a complex damage since its formation involves a DNA strand break and a cross-link between a damaged sugar residue and a vicinal cytosine base located most probably on the complementary DNA strand. In addition to its characterization, preliminary biological studies revealed that cells are able to remove the lesion from DNA. Repair studies have revealed the ability of cells to excise the lesion. Identification of the repair systems involved could represent an interesting challenge. (author)

  13. Detection of embedded radiation sources using temporal variation of gamma spectral data.

    Energy Technology Data Exchange (ETDEWEB)

    Shokair, Isaac R.

    2011-09-01

    Conventional full spectrum gamma spectroscopic analysis has the objective of quantitative identification of all the isotopes present in a measurement. For low energy resolution detectors, when photopeaks alone are not sufficient for complete isotopic identification, such analysis requires template spectra for all the isotopes present in the measurement. When many isotopes are present it is difficult to make the correct identification and this process often requires many trial solutions by highly skilled spectroscopists. This report investigates the potential of a new analysis method which uses spatial/temporal information from multiple low energy resolution measurements to test the hypothesis of the presence of a target spectrum of interest in these measurements without the need to identify all the other isotopes present. This method is referred to as targeted principal component analysis (TPCA). For radiation portal monitor applications, multiple measurements of gamma spectra are taken at equally spaced time increments as a vehicle passes through the portal and the TPCA method is directly applicable to this type of measurement. In this report we describe the method and investigate its application to the problem of detection of a radioactive localized source that is embedded in a distributed source in the presence of an ambient background. Examples using simulated spectral measurements indicate that this method works very well and has the potential for automated analysis for RPM applications. This method is also expected to work well for isotopic detection in the presence of spectrally and spatially varying backgrounds as a result of vehicle-induced background suppression. Further work is needed to include effects of shielding, to understand detection limits, setting of thresholds, and to estimate false positive probability.

  14. Characterization of Nanostructured Semiconductors by Ultrafast Luminescence Imaging

    Science.gov (United States)

    Blake, Jolie

    Single nanostructures are predicted to be the building blocks of next generation devices and have already been incorporated into prototypes for solar cells, biomedical devices and lasers. Their role in such applications requires a fundamental understanding of their opto-electronic properties and in particular the charge carrier dynamics occurring on an ultrafast timescale. Luminescence detection is a common approach used to investigate electronic properties of nanostructures because of the contact-less nature of these methods. They are, however, often not equipped to efficiently measure multiple single nanostructures nor do they have the temporal resolution necessary for observing femtosecond dynamics. This dissertation intends to address this paucity of techniques available for the contact-less measurement of single nanostructures through the development of an ultrafast wide-field Kerr-gated microscope system and measurement technique. The setup, operational in both the steady state and transient mode and capable of microscopic and spectroscopic measurements, was developed to measure the transient luminescence of single semiconductor nanostructures. With sub micron spatial resolution and the potential to achieve a temporal resolution greater than 90 fs, the system was used to probe the charge carrier dynamics at multiple discrete locations on single nanowires exhibiting amplified spontaneous emission. Using a rate model for amplified spontaneous emission, the transient emission data was fitted to extract the values of the competing Shockley-Read-Hall, non-geminate and Auger recombination constants. The capabilities of the setup were first demonstrated in the visible detection range, where single nanowires of the ternary alloy CdS x Se1-x were measured. The temporal emission dynamics at two separate locations were compared and calculation of the Langevin mobility revealed that the large carrier densities generated in the nanowire allows access to non

  15. Progress in ultrafast intense laser science XIII

    CERN Document Server

    III, Wendell; Paulus, Gerhard

    2017-01-01

    This thirteenth volume covers a broad range of topics from this interdisciplinary research field, focusing on atoms, molecules, and clusters interacting in intense laser field and high-order harmonics generation and their applications. The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, the interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance and attractions of the research topic at hand; these are followed by reports of cutting-edge discoveries.   .

  16. Progress in Ultrafast Intense Laser Science

    CERN Document Server

    Yamanouchi, Kaoru; Li, Ruxin; Chin, See Leang

    2009-01-01

    The PUILS series presents Progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science. PUILS has been stimulated by the recent development of ultrafast laser technologies. Each volume contains approximately 15 chapters, authored by researchers at the forefront. Each chapter opens with an overview of the topics to be discussed, so that researchers, who are not experts in the specific topics, as well as graduate students can grasp the importance and attractions of this sub-field of research, and these are followed by reports of cutting-edge discoveries. This fourth volume covers a broad range of topics from this interdisciplinary research field, focusing on strong field ionization of atoms; excitation, ionization and fragmentation of molecules; nonlinear intense optical phenomena and attosecond pulses; and laser - solid interactions and photoemission.

  17. Ultrafast magnetodynamics with free-electron lasers

    Science.gov (United States)

    Malvestuto, Marco; Ciprian, Roberta; Caretta, Antonio; Casarin, Barbara; Parmigiani, Fulvio

    2018-02-01

    The study of ultrafast magnetodynamics has entered a new era thanks to the groundbreaking technological advances in free-electron laser (FEL) light sources. The advent of these light sources has made possible unprecedented experimental schemes for time-resolved x-ray magneto-optic spectroscopies, which are now paving the road for exploring the ultimate limits of out-of-equilibrium magnetic phenomena. In particular, these studies will provide insights into elementary mechanisms governing spin and orbital dynamics, therefore contributing to the development of ultrafast devices for relevant magnetic technologies. This topical review focuses on recent advancement in the study of non-equilibrium magnetic phenomena from the perspective of time-resolved extreme ultra violet (EUV) and soft x-ray spectroscopies at FELs with highlights of some important experimental results.

  18. Progress in Ultrafast Intense Laser Science III

    CERN Document Server

    Yamanouchi, Kaoru; Agostini, Pierre; Ferrante, Gaetano

    2008-01-01

    The PUILS series presents Progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science. PUILS has been stimulated by the recent development of ultrafast laser technologies. Each volume contains approximately 15 chapters, authored by researchers at the forefront. Each chapter opens with an overview of the topics to be discussed, so that researchers, who are not experts in the specific topics, as well as graduate students can grasp the importance and attractions of this sub-field of research, and these are followed by reports of cutting-edge discoveries. This third volume covers a diverse range of disciplines, focusing on such topics as strong field ionization of atoms, ionization and fragmentation of molecules and clusters, generation of high-order harmonics and attosecond pulses, filamentation and laser plasma interaction, and the development of ultrashort and ultrahigh-intensity light sources.

  19. Ultra-fast framing camera tube

    Science.gov (United States)

    Kalibjian, Ralph

    1981-01-01

    An electronic framing camera tube features focal plane image dissection and synchronized restoration of the dissected electron line images to form two-dimensional framed images. Ultra-fast framing is performed by first streaking a two-dimensional electron image across a narrow slit, thereby dissecting the two-dimensional electron image into sequential electron line images. The dissected electron line images are then restored into a framed image by a restorer deflector operated synchronously with the dissector deflector. The number of framed images on the tube's viewing screen is equal to the number of dissecting slits in the tube. The distinguishing features of this ultra-fast framing camera tube are the focal plane dissecting slits, and the synchronously-operated restorer deflector which restores the dissected electron line images into a two-dimensional framed image. The framing camera tube can produce image frames having high spatial resolution of optical events in the sub-100 picosecond range.

  20. Progress in Ultrafast Intense Laser Science VIII

    CERN Document Server

    Nisoli, Mauro; Hill, Wendell; III, III

    2012-01-01

    The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science and optical science which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield as well as graduate students can grasp the importance and attractions of the research topic at hand. These are followed by reports of cutting-edge discoveries. This eighth volume covers a broad range of topics from this interdisciplinary research field, focusing on molecules interacting with ultrashort and intense laser fields, advanced technologies for the characterization of ultrashort laser pulses and their applications, laser plasma formation and laser acceleration.