WorldWideScience

Sample records for neutron interrogation signatures

  1. Neutron interrogation system using high gamma ray signature to detect contraband special nuclear materials in cargo

    Science.gov (United States)

    Slaughter, Dennis R [Oakland, CA; Pohl, Bertram A [Berkeley, CA; Dougan, Arden D [San Ramon, CA; Bernstein, Adam [Palo Alto, CA; Prussin, Stanley G [Kensington, CA; Norman, Eric B [Oakland, CA

    2008-04-15

    A system for inspecting cargo for the presence of special nuclear material. The cargo is irradiated with neutrons. The neutrons produce fission products in the special nuclear material which generate gamma rays. The gamma rays are detecting indicating the presence of the special nuclear material.

  2. Novel applications of fast neutron interrogation methods

    International Nuclear Information System (INIS)

    Gozani, Tsahi

    1994-01-01

    The development of non-intrusive inspection methods for contraband consisting primarily of carbon, nitrogen, oxygen, and hydrogen requires the use of fast neutrons. While most elements can be sufficiently well detected by the thermal neutron capture process, some important ones, e.g., carbon and in particular oxygen, cannot be detected by this process. Fortunately, fast neutrons, with energies above the threshold for inelastic scattering, stimulate relatively strong and specific gamma ray lines from these elements. The main lines are: 6.13 for O, 4.43 for C, and 5.11, 2.31 and 1.64 MeV for N. Accelerator-generated neutrons in the energy range of 7 to 15 MeV are being considered as interrogating radiations in a variety of non-intrusive inspection systems for contraband, from explosives to drugs and from coal to smuggled, dutiable goods. In some applications, mostly for inspection of small items such as luggage, the decision process involves a rudimentary imaging, akin to emission tomography, to obtain the localized concentration of various elements. This technique is called FNA - Fast Neutron Analysis. While this approach offers improvements over the TNA (Thermal Neutron Analysis), it is not applicable to large objects such as shipping containers and trucks. For these challenging applications, a collimated beam of neutrons is rastered along the height of the moving object. In addition, the neutrons are generated in very narrow nanosecond pulses. The point of their interaction inside the object is determined by the time of flight (TOF) method, that is measuring the time elapsed from the neutron generation to the time of detection of the stimulated gamma rays. This technique, called PFNA (Pulsed Fast Neutron Analysis), thus directly provides the elemental, and by inference, the chemical composition of the material at every volume element (voxel) of the object. The various neutron-based techniques are briefly described below. ((orig.))

  3. A review of conventional explosives detection using active neutron interrogation

    International Nuclear Information System (INIS)

    Whetstone, Z.D.; Kearfott, K.J.

    2014-01-01

    Conventional explosives are relatively easy to obtain and may cause massive harm to people and property. There are several tools employed by law enforcement to detect explosives, but these can be subverted. Active neutron interrogation is a viable alternative to those techniques, and includes: fast neutron analysis, thermal neutron analysis, pulsed fast/thermal neutron analysis, neutron elastic scatter, and fast neutron radiography. These methods vary based on neutron energy and radiation detected. A thorough review of the principles behind, advantages, and disadvantages of the different types of active neutron interrogation is presented. (author)

  4. Time-dependent delayed signatures from energetic photon interrogations

    International Nuclear Information System (INIS)

    Norman, Daren R.; Jones, James L.; Blackburn, Brandon W.; Haskell, Kevin J.; Johnson, James T.; Watson, Scott M.; Hunt, Alan W.; Spaulding, Randy; Harmon, Frank

    2007-01-01

    Pulsed photonuclear interrogation environments generated by 8-24 MeV electron linac are rich with time-dependent, material-specific, radiation signatures. Nitrogen-based explosives and nuclear materials can be detected by exploiting these signatures in different delayed-time regions. Numerical and experimental results presented in this paper show the unique time and energy dependence of these signatures. It is shown that appropriate delayed-time windows are essential to acquire material-specific signatures in pulsed photonuclear assessment environments. These developments demonstrate that pulsed, high-energy, photon-inspection environments can be exploited for time-dependent, material-specific signatures through the proper operation of specialized detectors and detection methods

  5. Survey of Neutron Generators for Active Interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Moss, Calvin Elroy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, William L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sundby, Gary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chichester, David L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johnson, James P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-05-02

    Some of these commercially available generators meet all of the requirements in Table 1, but there are other concerns. Most generators containing SF6 will be required to have the SF6 gas removed for shipping because of DOT regulations. However, Thermo Fisher has a DOT exemption. The P211 and B211 from Thermo Fisher meet the requirements listed in Table 1, but they are old designs and are no longer offered for sale. Also, they require 15 minutes or more of warmup before neutron output is available, and they lack a modern digital control. The nGen-300C from Starfire Industries is interesting because it is a portable system, but it uses the DD reaction for 2.5 MeV neutrons, which are not as penetrating as the 14 MeV neutrons from the DT reaction. The MP 320 from Thermo Fisher is another portable system, but the minimum pulse rate is 250 Hz, which is too fast for measurement of delayed neutrons and re-interrogation by delayed neutrons between pulses. The Genie 16 from Sodern (from France) probably meets the requirements, but the required power is probably too high for battery operation. The generators from Russia and China may be difficult to purchase, and service may not be available. The power required by some of these generators is low enough that batteries can be used. The portable units, nGen-300C and the MP320, could easily be operated with batteries. Other generators with low power requirements, as specified in the above vendors list, could possibly be operated with reason size batteries. The batteries do not need to be internal to the generator, but can be in a separate package. The availability of high capacity lithium batteries with sophisticated safety circuits makes battery operation more possible now than when lead acid batteries were used. The best path forward probably requires working with vendors of the existing systems. If Starfire Industries could be persuaded to put tritium in their nGen-300C generator, possibly in collaboration with a national

  6. Subthreshold neutron interrogator for detection of radioactive materials

    Science.gov (United States)

    Evans, Michael L.; Menlove, Howard O.; Baker, Michael P.

    1980-01-01

    A device for detecting fissionable material such as uranium in low concentrations by interrogating with photoneutrons at energy levels below 500 keV, and typically about 26 keV. Induced fast neutrons having energies above 500 keV by the interrogated fissionable material are detected by a liquid scintillator or recoil proportional counter which is sensitive to the induced fast neutrons. Since the induced fast neutrons are proportional to the concentration of fissionable material, detection of induced fast neutrons indicate concentration of the fissionable material.

  7. A Kinematically Beamed, Low Energy Pulsed Neutron Source for Active Interrogation

    International Nuclear Information System (INIS)

    Dietrich, D.; Hagmann, C.; Kerr, P.; Nakae, L.; Rowland, M.; Snyderman, N.; Stoeffl, W.; Hamm, R.

    2004-01-01

    We are developing a new active interrogation system based on a kinematically focused low energy neutron beam. The key idea is that one of the defining characteristics of SNM (Special Nuclear Materials) is the ability for low energy or thermal neutrons to induce fission. Thus by using low energy neutrons for the interrogation source we can accomplish three goals, (1) Energy discrimination allows us to measure the prompt fast fission neutrons produced while the interrogation beam is on; (2) Neutrons with an energy of approximately 60 to 100 keV do not fission 238U and Thorium, but penetrate bulk material nearly as far as high energy neutrons do and (3) below about 100keV neutrons lose their energy by kinematical collisions rather than via the nuclear (n,2n) or (n,n') processes thus further simplifying the prompt neutron induced background. 60 keV neutrons create a low radiation dose and readily thermal capture in normal materials, thus providing a clean spectroscopic signature of the intervening materials. The kinematically beamed source also eliminates the need for heavy backward and sideway neutron shielding. We have designed and built a very compact pulsed neutron source, based on an RFQ proton accelerator and a lithium target. We are developing fast neutron detectors that are nearly insensitive to the ever-present thermal neutron and neutron capture induced gamma ray background. The detection of only a few high energy fission neutrons in time correlation with the linac pulse will be a clear indication of the presence of SNM

  8. Detection of SNM by Pulsed Neutron Interrogation

    International Nuclear Information System (INIS)

    Pedersen, Bent; Mayorov, Valeriy; Roesgen, Eric; Mosconi, Marita; Crochemore, Jean-Michel; Ocherashvili, Aharon; Beck, Arie; Ettedgui, Hanania

    2014-01-01

    A method for the detection of special nuclear materials (SNM) in shielded containers which is both sensitive and easily applicable under field conditions is presented. The method applies neutron induced fission in SNM by means of an external pulsed neutron source with subsequent detection of the fast prompt fission neutrons. Liquid scintillation detectors surrounding the container under investigation are able to discriminate gamma rays from fast neutrons by the so-called pulse shape discrimination technique (PSD)

  9. Fissile mass estimation by pulsed neutron source interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Israelashvili, I., E-mail: israelashvili@gmail.com [Nuclear Research Center of the Negev, P.O.B 9001, Beer Sheva 84190 (Israel); Dubi, C.; Ettedgui, H.; Ocherashvili, A. [Nuclear Research Center of the Negev, P.O.B 9001, Beer Sheva 84190 (Israel); Pedersen, B. [Nuclear Security Unit, Institute for Transuranium Elements, Joint Research Centre, Via E. Fermi, 2749, 21027 Ispra (Italy); Beck, A. [Nuclear Research Center of the Negev, P.O.B 9001, Beer Sheva 84190 (Israel); Roesgen, E.; Crochmore, J.M. [Nuclear Security Unit, Institute for Transuranium Elements, Joint Research Centre, Via E. Fermi, 2749, 21027 Ispra (Italy); Ridnik, T.; Yaar, I. [Nuclear Research Center of the Negev, P.O.B 9001, Beer Sheva 84190 (Israel)

    2015-06-11

    Passive methods for detecting correlated neutrons from spontaneous fissions (e.g. multiplicity and SVM) are widely used for fissile mass estimations. These methods can be used for fissile materials that emit a significant amount of fission neutrons (like plutonium). Active interrogation, in which fissions are induced in the tested material by an external continuous source or by a pulsed neutron source, has the potential advantages of fast measurement, alongside independence of the spontaneous fissions of the tested fissile material, thus enabling uranium measurement. Until recently, using the multiplicity method, for uranium mass estimation, was possible only for active interrogation made with continues neutron source. Pulsed active neutron interrogation measurements were analyzed with techniques, e.g. differential die away analysis (DDA), which ignore or implicitly include the multiplicity effect (self-induced fission chains). Recently, both, the multiplicity and the SVM techniques, were theoretically extended for analyzing active fissile mass measurements, made by a pulsed neutron source. In this study the SVM technique for pulsed neutron source is experimentally examined, for the first time. The measurements were conducted at the PUNITA facility of the Joint Research Centre in Ispra, Italy. First promising results, of mass estimation by the SVM technique using a pulsed neutron source, are presented.

  10. Fissile materials in solution concentration measured by active neutron interrogation

    International Nuclear Information System (INIS)

    Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

    1993-01-01

    The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a 252 Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.)

  11. Improved Fission Neutron Data Base for Active Interrogation of Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi, Sara; Czirr, J. Bart; Haight, Robert; Kovash, Michael; Tsvetkov, Pavel

    2013-11-06

    This project will develop an innovative neutron detection system for active interrogation measurements. Many active interrogation methods to detect fissionable material are based on the detection of neutrons from fission induced by fast neutrons or high-energy gamma rays. The energy spectrum of the fission neutrons provides data to identify the fissionable isotopes and materials such as shielding between the fissionable material and the detector. The proposed path for the project is as follows. First, the team will develop new neutron detection systems and algorithms by Monte Carlo simulations and bench-top experiments. Next, They will characterize and calibrate detection systems both with monoenergetic and white neutron sources. Finally, high-fidelity measurements of neutron emission from fissions induced by fast neutrons will be performed. Several existing fission chambers containing U-235, Pu-239, U-238, or Th-232 will be used to measure the neutron-induced fission neutron emission spectra. The challenge for making confident measurements is the detection of neutrons in the energy ranges of 0.01 – 1 MeV and above 8 MeV, regions where the basic data on the neutron energy spectrum emitted from fission is least well known. In addition, improvements in the specificity of neutron detectors are required throughout the complete energy range: they must be able to clearly distinguish neutrons from other radiations, in particular gamma rays and cosmic rays. The team believes that all of these challenges can be addressed successfully with emerging technologies under development by this collaboration. In particular, the collaboration will address the area of fission neutron emission spectra for isotopes of interest in the advanced fuel cycle initiative (AFCI).

  12. Basic concepts underlying fast-neutron-based contraband interrogation technology

    International Nuclear Information System (INIS)

    Fink, C.L.; Guenther, P.T.; Smith, D.L.

    1992-01-01

    All accelerator-based fast-neutron contraband interrogation systems have many closely interrelated subsystems, whose performance parameters will be critically interdependent. For optimal overall performance, a systems analysis design approach is required. This paper provides a general overview of the interrelationships and the tradeoffs to be considered for optimization of nonaccelerator subsystems

  13. Design and characterisation of a pulsed neutron interrogation facility

    International Nuclear Information System (INIS)

    Favalli, A.; Pedersen, B.

    2007-01-01

    The Joint Research Centre recently obtained a license to operate a new experimental device intended for research in the field of nuclear safeguards. The research projects currently being planned for the new device includes mass determination of fissile materials in matrices and detection of contraband non-nuclear materials. The device incorporates a commercial pulsed neutron generator and a large graphite mantle surrounding the sample cavity. In this configuration, a relatively high thermal neutron flux with a long lifetime is achieved inside the sample cavity. By pulsing the neutron generator, a sample may be interrogated by a pure thermal neutron flux during repeated time periods. The paper reports on the design of the new device and the pulsed fast and thermal neutron source. The thermal neutron flux caused by the neutron generator and the graphite structure has been characterised by foil activation, fission chamber and 3 He proportional counter measurements. (authors)

  14. Evaluation of the neutron self-interrogation approach for assay of plutonium in high materials

    International Nuclear Information System (INIS)

    Russo, P.A.; Menlove, H.O.; Fife, K.W.; West, M.H.

    1987-01-01

    The pyrochemical scrap recovery processes, designed to extract impurities from plutonium metal and compounds, generate a variety of plutonium-laden residues consisting of high (α,n) matrices of varying chemical composition, and often containing grams to tens of grams of americium. For such materials, multiplication corrections based on real neutron coincidence count rate, R, and total neutron count rate, T, measurements cannot be applied because of the large, unknown, and variable (α,n) component in the total neutron emission rate. A study of the prototype self-interrogation assay method is in progress at the Los Alamos plutonium facility. In the self-interrogation approach, the assay signature R(IF)/T is a function of effective fissile plutonium content, where R(IF) is the induced fission component of the measured reals rate, and T is the measured, (α,n)-dominated totals rate. The present study includes a calibration effort using standards consisting of mixtures of PuO 2 and PuF 4 in a salt-strip matrix. The neutron measurements of the standards and the process materials have been performed at the Los Alamos Plutonium Facility. The precision and accuracy of the self-interrogation method applied to pyrochemical residues is examined in this study

  15. Thermal neutron imaging in an active interrogation environment

    International Nuclear Information System (INIS)

    Vanier, P.E.; Forman, L.; Norman, D.R.

    2009-01-01

    We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

  16. System design considerations for fast-neutron interrogation systems

    International Nuclear Information System (INIS)

    Micklich, B.J.; Curry, B.P.; Fink, C.L.; Smith, D.L.; Yule, T.J.

    1993-01-01

    Nonintrusive interrogation techniques that employ fast neutrons are of interest because of their sensitivity to light elements such as carbon, nitrogen, and oxygen. The primary requirement of a fast-neutron inspection system is to determine the value of atomic densities, or their ratios, over a volumetric grid superimposed on the object being interrogated. There are a wide variety of fast-neutron techniques that can provide this information. The differences between the various nuclear systems can be considered in light of the trade-offs relative to the performance requirements for each system's components. Given a set of performance criteria, the operational requirements of the proposed nuclear systems may also differ. For instance, resolution standards will drive scanning times and tomographic requirements, both of which vary for the different approaches. We are modelling a number of the fast-neutron interrogation techniques currently under consideration, to include Fast Neutron Transmission Spectroscopy (FNTS), Pulsed Fast Neutron Analysis (PFNA), and its variant, 14-MeV Associated Particle Imaging (API). The goals of this effort are to determine the component requirements for each technique, identify trade-offs that system performance standards impose upon those component requirements, and assess the relative advantages and disadvantages of the different approaches. In determining the component requirements, we will consider how they are driven by system performance standards, such as image resolution, scanning time, and statistical uncertainty. In considering the trade-offs between system components, we concentrate primarily on those which are common to all approaches, for example: source characteristics versus detector array requirements. We will then use the analysis to propose some figures-of-merit that enable performance comparisons between the various fast-neutron systems under consideration. The status of this ongoing effort is presented

  17. Development of active neutron interrogation techniques at Harwell

    International Nuclear Information System (INIS)

    Armitage, B.H.; Chard, P.M.J.; Packer, T.W.; Swinhoe, M.T.; Syme, D.B.

    1990-01-01

    Active neutron interrogation techniques capable of measuring the fissile content of a range of waste drum sizes and contents have been developed at Harwell. This paper describes measurements which have been made to investigate the behaviour of these assay systems for the difficult case of concreted waste in a heterogeneous matrix. The drums have been measured using a Cf shuffler and a differential die-away system, with supporting information obtained from a segmented gamma-scanner. Good correspondence has been observed between the two different neutron interrogation techniques. It was concluded that the measurement of highly heterogeneous wastes is likely to be more effective if calibration can be undertaken with representative artificial matrices. Further measurement and analysis remains to be undertaken

  18. Active Interrogation of Sensitive Nuclear Material Using Laser Driven Neutron Beams

    International Nuclear Information System (INIS)

    Favalli, Andrea; Roth, Markus

    2015-01-01

    An investigation of the viability of a laser-driven neutron source for active interrogation is reported. The need is for a fast, movable, operationally safe neutron source which is energy tunable and has high-intensity, directional neutron production. Reasons for the choice of neutrons and lasers are set forth. Results from the interrogation of an enriched U sample are shown.

  19. INL Neutron Interrogation R and D: FY2010 MPACT End of Year Report

    International Nuclear Information System (INIS)

    Chichester, D.L.; Seabury, E.H.; Wharton, J.; Watson, S.M.

    2010-01-01

    Experiments have been carried out to investigate the feasibility and utility of using neutron interrogation and small-scale, portable prompt gamma-ray neutron activation analysis (PGNAA) instruments for assaying uranium for safeguards applications. Prior work has shown the potential of the PGNAA technique for assaying uranium using reactor-based neutron sources and high-yield electronic neutron generators (ENGs). In this project we adapted Idaho National Laboratory's portable isotopic neutron spectroscopy (PINS) PGNAA system for measuring natural-enrichment uranium yellowcake and metallic depleted uranium and highly enriched uranium. This work used 252Cf as well as deuterium-deuterium (DD) and deuterium-tritium (DT) ENGs. For PGNAA measurements a limiting factor when assaying large objects is the detector dead time due to fast-neutron scattering off of the uranium; this limits the maximum useable neutron source strength to O(107) neutrons per second. Under these conditions the low PGNAA reaction cross sections for uranium prohibited the collection of useful uranium PGNAA signatures from either the yellowcake or metallic uranium samples. Measurement of the decay product activation in these materials following irradiation in the PGNAA geometry similarly did not produce useful uranium activation product - fission product signatures. A customized irradiation geometry tailored to optimally thermalize the interrogation neutron source, intended only for generating long-lived activation products - fission products and not intended for PGNAA measurements, might be possible using small scale ENGs but an application need and a modeling simulation exercise would be recommended before advancing to experiments. Neutron interrogation PGNAA using a DT-ENG was found to be a quick and useful qualitative method for detecting the presence of oxygen in natural-enrichment uranium yellowcake. With a low effort of development work it would be reasonable to expect this measurement could be

  20. Influence of fuel composition on the spent fuel verification by Self‑Interrogation Neutron Resonance Densitometry

    International Nuclear Information System (INIS)

    Rossa, Riccardo; Borella, Alessandro; Van der Meer, Klaas; Labeau, Pierre‑Etienne; Pauly, Nicolas

    2015-01-01

    The Self‑Interrogation Neutron Resonance Densitometry (SINRD) is a passive Non‑Destructive Assay (NDA) that is developed for the safeguards verification of spent nuclear fuel. The main goal of SINRD is the direct quantification of 239Pu by estimating the SINRD signature, which is the ratio between the neutron flux in the fast energy region and in the region close to the 0.3 eV resonance of 239 Pu. The resonance region was chosen because the reduction of the neutron flux within 0.2-0.4 eV is due mainly to neutron absorption from 239 Pu, and therefore the SINRD signature can be correlated to the 239Pu mass in the fuel assembly. This work provides an estimate of the influence of 239 Pu and other nuclides on the SINRD signature. This assessment is performed by Monte Carlo simulations by introducing several nuclides in the fuel material composition and by calculating the SINRD signature for each case. The reference spent fuel library developed by SCK CEN was used for the detailed fuel compositions of PWR 17x17 fuel assemblies with different initial enrichments, burnup, and cooling times. The results from the simulations show that the SINRD signature is mainly correlated to the 239 Pu mass, with significant influence by 235 U. Moreover, the SINRD technique is largely insensitive to the cooling time of the assembly, while it is affected by the burnup and initial enrichment of the fuel. Apart from 239 Pu and 235 U, many other nuclides give minor contributions to the SINRD signature, especially at burnup higher than 20 GWd/tHM.

  1. Signal predictions for a proposed fast neutron interrogation method

    International Nuclear Information System (INIS)

    Sale, K.E.

    1992-12-01

    We have applied the Monte Carlo radiation transport code COG) to assess the utility of a proposed explosives detection scheme based on neutron emission. In this scheme a pulsed neutron beam is generated by an approximately seven MeV deuteron beam incident on a thick Be target. A scintillation detector operating in the current mode measures the neutrons transmitted through the object as a function of time. The flight time of unscattered neutrons from the source to the detector is simply related to the neutron energy. This information along with neutron cross section excitation functions is used to infer the densities of H, C, N and O in the volume sampled. The code we have chosen to use enables us to create very detailed and realistic models of the geometrical configuration of the system, the neutron source and of the detector response. By calculating the signals that will be observed for several configurations and compositions of interrogated object we can investigate and begin to understand how a system that could actually be fielded will perform. Using this modeling capability many early on with substantial savings in time and cost and with improvements in performance. We will present our signal predictions for simple single element test cases and for explosive compositions. From these studies it is dear that the interpretation of the signals from such an explosives identification system will pose a substantial challenge

  2. Scoping studies - photon and low energy neutron interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G.; Harker, Y.; Jones, J. [LMITCo, Idaho Falls, ID (United States); Harmon, F. [Idaho State Univ., Pocatello, ID (United States)

    1997-11-01

    High energy photon interrogation of waste containers, with the aim of producing photo nuclear reactions, in specific materials, holds the potential of good penetration and rapid analysis. Compact high energy ({le} 10 MeV) photon sources in the form of electron linacs producing bremstrahlung radiation are readily available. Work with the Varitron variable energy accelerator at ISU will be described. Advantages and limitations of the technique will be discussed. Using positive ion induced neutron producing reactions, it is possible to generate neutrons in a specific energy range. By this means, variable penetration and specific reactions can be excited in the assayed material. Examples using the {sup 3}H(p,n) and {sup 7}Li(p,n) reactions as neutron sources will be discussed. 4 refs., 7 figs.

  3. Expected total counts for the Self-Interrogation Neutron Resonance Densitometry measurements of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Rossa, Riccardo [Belgian nuclear research centre SCK.CEN (Belgium); Universite Libre de Bruxelles (Belgium); Borella, Alessandro; Van der Meer, Klaas [Belgian nuclear research centre SCK.CEN. Boeretang 200, 2400 Mol (Belgium); Labeau, Pierre-Etienne; Pauly, Nicolas [Universite Libre de Bruxelles. Av. F. D. Roosevelt 50, B1050 Brussels (Belgium)

    2015-07-01

    The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive neutron technique that aims at a direct quantification of {sup 239}Pu in spent fuel assemblies by measuring the attenuation of the neutron flux in the energy region close to the 0.3 eV resonance of {sup 239}Pu. The {sup 239}Pu mass is estimated by calculating the SINRD signature, that is the ratio between the neutron counts in the fast energy region and around the 0.3 eV resonance region. The SINRD measurement approach in this study consisted in introducing a small neutron detector in the central guide tube of a PWR 17x17 fuel assembly. In order to measure the neutron flux in the energy regions defined in the SINRD signature, different detector types were used. The response of a bare {sup 238}U fission chamber is considered for the determination of the fast neutron flux, while other thermal-epithermal detectors wrapped in neutron absorbers are envisaged to measure the neutron flux around the resonance region. This paper provides an estimation of the total neutron counts that can be achieved with the detector types proposed for the SINRD measurement. In the first section a set of detectors are evaluated in terms of total neutron counts and sensitivity to the {sup 239}Pu content, in order to identify the optimal measurement configuration for each detector type. Then a study is performed to increase the total neutron counts by increasing the detector size. The study shows that the highest total neutron counts are achieved by using either {sup 3}He or {sup 10}B proportional counters because of the high neutron efficiency of these detectors. However, the calculations indicate that the biggest contribution to the measurement uncertainty is due to the measurement of the fast neutron flux. Finally, similar sensitivity to the {sup 239}Pu content is obtained by using the different detector types for the measurement of the neutron flux close to the resonance region. Therefore, the total neutron counts

  4. Detection of Special Nuclear Material in Cargo Containers Using Neutron Interrogation

    International Nuclear Information System (INIS)

    Slaughter, D.; Accatino, M.; Bernstein, A.; Candy, J.; Dougan, A.; Hall, J.; Loshak, A.; Manatt, D.; Meyer, A.; Pohl, B.; Prussin, S.; Walling, R.; Weirup, D.

    2003-01-01

    The goal of the work reported here is to develop a concept for an active neutron interrogation system that can detect small targets of SNM contraband in cargo containers, roughly 5 kg HEU or 1 kg Pu, even when well shielded by a thick cargo. It is essential that the concept be reliable and have low false-positive and false-negative error rates. It also must be rapid to avoid interruption of commerce, completing the analysis in minutes. A new radiation signature unique to SNM has been identified that utilizes high-energy (E γ = 3-7 MeV) fission product γ-ray emission. Fortunately, this high-energy γ-ray signature is robust in that it is very distinct compared to normal background radiation where there is no comparable high-energy γ-ray radiation. Equally important, it has a factor of 10 higher yield than delayed neutrons that are the basis of classical interrogation technique normally used on small unshielded specimens of SNM. And it readily penetrates two meters of low-Z and high-Z cargo at the expected density of ∼ 0.5 gm/cm 3 . Consequently, we expect that in most cases the signature flux at the container wall is at least 2-3 decades more intense than delayed neutron signals used historically and facilitates the detection of SNM even when shielded by thick cargo. Experiments have verified this signature and its predicted characteristics. However, they revealed an important interference due to the activation of 16 O by the 16 O(n,p) 16 N reaction that produces a 6 MeV γ-ray following a 7-sec β-decay of the 16 N. This interference is important when irradiating with 14 MeV neutrons but is eliminated when lower energy neutron sources are utilized since the reaction threshold for 16 O(n,p) 16 N is 10 MeV. The signature γ-ray fluxes exiting a thick cargo can be detected in large arrays of scintillation detectors to produce useful signal count rates of 2-4 x 10 4 cps. That is high enough to quickly identify SNM fission by its characteristic high energy

  5. Nondestructive assay of subassemblies of various spent or fresh fuels by active neutron interrogation

    International Nuclear Information System (INIS)

    Ragan, G.L.; Ricker, C.W.; Chiles, M.M.; Ingersoll, D.T.; Slaughter, G.G.

    1979-01-01

    Recent studies show that subassemblies containing various spent fuels could be assayed rapidly and accurately by a nondestructive assay system using active neutron interrogation and prompt-neutron detection. Subassembly penetration is achieved by 24-keV (Sb--Be) interrogation neutrons; the spent-fuel neutron background is overridden by using strong interrogating sources and prompt-neutron signals, and background gammas are absorbed by lead. Experiments have demonstrated the potential for assaying with better than 5% accuracy, three spent plutonium-fueled subassemblies per hour. Calculations, validated by experiments, predict even better performance for fresh or uranium-fueled subassemblies; several performance estimates are given

  6. Passive neutron interrogation in systems with a poorly characterized detection efficiency

    International Nuclear Information System (INIS)

    Dubi, Chen; Oster, Elad; Ocherashvilli, Aharon; Pedersen, Bent; Hutszy, Janus

    2014-01-01

    Passive neutron interrogation for fissile mass estimation, relying on neutrons coming from spontaneous fission events, is considered a standard NDT procedure in the nuclear safeguard and safety community. Since most structure materials are (relatively) transparent to neutron radiation, passive neutron interrogation is considered highly effective in the analysis of dirty, poorly characterized samples. On the other hand, since a typical passive interrogation assembly is based on 3He detectors, neutrons from additional neutron sources (mainly (α,n) reactions and induced fissions in the tested sample) cannot be separated from the main spontaneous fission source through energetic spectral analysis. There for, applying the passive interrogation methods the implementation of Neutron Multiplicity Counting (NMC) methods for separation between the main fission source and the additional sources. Applying NMC methods requires a well characterized system, in the sense that both system die away time and detection efficiency must be well known (and in particular, independent of the tested sample)

  7. Expected count rate for the Self- Interrogation Neutron Resonance Densitometry measurements of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Rossa, Riccardo [SCK.CEN, Belgian Nuclear Research Centre, Boeretang, 200 - B2400 Mol (Belgium); Universite libre de Bruxelles, Ecole polytechnique de Bruxelles - Service de Metrologie Nucleaire, CP 165/84, Avenue F.D. Roosevelt, 50 - B1050 Brussels (Belgium); Borella, Alessandro; Van der Meer, Klaas [SCK.CEN, Belgian Nuclear Research Centre, Boeretang, 200 - B2400 Mol (Belgium); Labeau, Pierre-Etienne; Pauly, Nicolas [Universite libre de Bruxelles, Ecole polytechnique de Bruxelles - Service de Metrologie Nucleaire, CP 165/84, Avenue F.D. Roosevelt, 50 - B1050 Brussels (Belgium)

    2015-07-01

    The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive neutron technique that aims at a direct quantification of {sup 239}Pu in the fuel assemblies by measuring the attenuation of the neutron flux in the energy region close to the 0.3 eV resonance of {sup 239}Pu. The {sup 239}Pu mass is estimated by calculating the SINRD signature, that is the ratio between the neutron flux integrated over the fast energy region and around the 0.3 eV resonance region. The SINRD measurement approach considered in this study consists in introducing a small neutron detector in the central guide tube of a PWR 17x17 fuel assembly. In order to measure the neutron flux in the energy regions defined in the SINRD signature, different detector types are used. The response of a bare {sup 238}U fission chamber is considered for the determination of the fast neutron flux, while other thermal-epithermal detectors wrapped in neutron absorbers are envisaged to measure the neutron flux around the resonance region. This paper provides an estimation of the count rate that can be achieved with the detector types proposed for the SINRD measurement. In the first section a set of detectors are evaluated in terms of count rate and sensitivity to the {sup 239}Pu content, in order to identify the optimal measurement configuration for each detector type. Then a study is performed to increase the count rate by increasing the detector size. The study shows that the highest count rate is achieved by using either {sup 3}He or {sup 10}B proportional counters because of the high neutron efficiency of these detectors. However, the calculations indicate that the biggest contribution to the measurement uncertainty is due to the measurement of the fast neutron flux. Finally, similar sensitivity to the {sup 239}Pu content is obtained by using the different detector types for the measurement of the neutron flux close to the resonance region. Therefore, the count rate associated to each detector type

  8. Neutron interrogation of actinides with a 17 MeV electron accelerator and first results from photon and neutron interrogation non-simultaneous measurements combination

    Energy Technology Data Exchange (ETDEWEB)

    Sari, A., E-mail: adrien.sari@cea.fr [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, 91191 Gif-sur-Yvette Cedex (France); Carrel, F.; Lainé, F. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, 91191 Gif-sur-Yvette Cedex (France); Lyoussi, A. [CEA, DEN, 13108 Saint-Paul-Lez-Durance Cedex (France)

    2013-10-01

    In this article, we demonstrate the feasibility of neutron interrogation using the conversion target of a 17 MeV linear electron accelerator as a neutron generator. Signals from prompt neutrons, delayed neutrons, and delayed gamma-rays, emitted by both uranium and plutonium samples were analyzed. First results from photon and neutron interrogation non-simultaneous measurements combination are also reported in this paper. Feasibility of this technique is shown in the frame of the measurement of uranium enrichment. The latter was carried out by combining detection of prompt neutrons from thermal fission and delayed neutrons from photofission, and by combining delayed gamma-rays from thermal fission and delayed gamma-rays from photofission.

  9. Accelerator requirements for fast-neutron interrogation of luggage and cargo

    International Nuclear Information System (INIS)

    Micklich, B.J.; Fink, C.L.; Yule, T.J.

    1995-01-01

    Several different fast-neutron based techniques are being studied for the detection of contraband substances in luggage and cargo containers. The present work discusses the accelerator requirements for fast-neutron transmission spectroscopy (FNTS), pulsed fast-neutron analysis (PFNA), and 14-MeV neutron interrogation. These requirements are based on the results of Monte-Carlo simulations of neutron or gamma detection rates. Accelerator requirements are driven by count-rate considerations, spatial resolution and acceptable uncertainties in elemental compositions. The authors have limited their analyses to luggage inspection with FNTS and to cargo inspection with PFNA or 14-MeV neutron interrogation

  10. Detection and identification of unexploded ordnance (UXO) by neutron interrogation

    International Nuclear Information System (INIS)

    Caffrey, A.J.; Hartwell, J.K.; Krebs, K.M.; McLaughlin, G.D.

    1998-01-01

    This document reviews the principle of operation and unexploded ordnance (UXO) signatures of the PINS Chemical Assay System, a prompt-gamma-ray neutron activation analysis (PGNAA) for the identification of recovered UXO. Two related low cost methods for buried landmine detection are also suggested. Nuclear methods may compliment existing search techniques to improve the overall probability of detection and to reduce the false positive rate of other technologies. In addition, nuclear methods are a proven method for identification of UXO such as landmines

  11. SIMULATION OF CARGO CONTAINER INTERROGATION BY D-D NEUTRONS

    International Nuclear Information System (INIS)

    Lou, Tak Pui; Antolak, Arlyn

    2007-01-01

    High fidelity, three-dimensional computer models based on a CAD drawing of an intermodal cargo container, representative payload objects, and detector array panels were developed to simulate the underlying physical events taking place during active interrogation. These computer models are used to assess the performance of interrogation systems with different sources and detection schemes. In this presentation, we will show that the use oversimplified models, such as analyzing homogenized payloads only, can lead to errors in determining viable approaches for interrogation

  12. Active-interrogation measurements of fast neutrons from induced fission in low-enriched uranium

    International Nuclear Information System (INIS)

    Dolan, J.L.; Marcath, M.J.; Flaska, M.; Pozzi, S.A.; Chichester, D.L.; Tomanin, A.; Peerani, P.

    2014-01-01

    A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutrons to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials. -- Highlights: • We studied low-enriched uranium using active-interrogation experiments including a deuterium–tritium neutron generator and an americium–lithium isotopic neutron source. • Liquid scintillators measured induced-fission neutrons from the active-interrogation methods. • Fast-neutron (DT) and thermal-neutron (Am–Li) interrogation resulted in the measurement of trends in uranium mass and 235 U enrichment respectively. • MCNPX-PoliMi, the Monte Carlo transport code, simulated the measured induced-fission neutron trends in the liquid scintillators

  13. Active-interrogation measurements of fast neutrons from induced fission in low-enriched uranium

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, J.L., E-mail: jldolan@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Marcath, M.J.; Flaska, M.; Pozzi, S.A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Chichester, D.L. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Tomanin, A.; Peerani, P. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Ispra (Italy)

    2014-02-21

    A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutrons to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials. -- Highlights: • We studied low-enriched uranium using active-interrogation experiments including a deuterium–tritium neutron generator and an americium–lithium isotopic neutron source. • Liquid scintillators measured induced-fission neutrons from the active-interrogation methods. • Fast-neutron (DT) and thermal-neutron (Am–Li) interrogation resulted in the measurement of trends in uranium mass and {sup 235}U enrichment respectively. • MCNPX-PoliMi, the Monte Carlo transport code, simulated the measured induced-fission neutron trends in the liquid scintillators.

  14. Hidden explosives detector employing pulsed neutron and x-ray interrogation

    International Nuclear Information System (INIS)

    Schultz, F.J.; Caldwell, J.T.

    1993-01-01

    Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected

  15. Hidden explosives detector employing pulsed neutron and x-ray interrogation

    Science.gov (United States)

    Schultz, Frederick J.; Caldwell, John T.

    1993-01-01

    Methods and systems for the detection of small amounts of modern, highly-explosive nitrogen-based explosives, such as plastic explosives, hidden in airline baggage. Several techniques are employed either individually or combined in a hybrid system. One technique employed in combination is X-ray imaging. Another technique is interrogation with a pulsed neutron source in a two-phase mode of operation to image both nitrogen and oxygen densities. Another technique employed in combination is neutron interrogation to form a hydrogen density image or three-dimensional map. In addition, deliberately-placed neutron-absorbing materials can be detected.

  16. A l-nCi/g sensitivity transuranic waste assay system using pulsed neutron interrogation

    International Nuclear Information System (INIS)

    Kunz, W.E.; Atencio, J.D.; Caldwell, J.T.

    1980-01-01

    We have developed a pulsed thermal neutron interrogation system and have demonstrated a sub-1-nCi/g assay sensitivity for high density TRU wastes contained in 200-liter barrels. We detect prompt fission neutrons, resulting in greatly enhanced sensitivity compared to techniques in which delayed fission neutrons are detected. We observe a linear assay response over at least three orders of magnitude in 235 U (or 239 Pu) mass. We also have measured a flat (to +-10%) interrogation flux profile throughout the volume of a 200-liter barrel filled with 200 kg of sand and vermiculite, which indicates flatness of response to fissile material at different locations within the barrel

  17. The SVM Method for Fissile Mass Estimation through Passive Neutron Interrogation: Advances and Developments

    International Nuclear Information System (INIS)

    Dubi, C.; Shvili, Israel I.

    2014-01-01

    Fissile mass estimation through passive neutron interrogation is now one of the main techniques for NDT of fissile mass estimation, due to the relative transparency of neutron radiation to structural materials- making it extremely effective in poorly characterized or dirty samples . Passive neutron interrogation relies on the fact that the number of neutrons emitted (per time unit) due to spontaneous fissions from the sample is proportional to the mass of the detected sample. However, since the measurement is effected by additional neutron sources- mainly (D±n) reactions and induced fission chain in the tested sample, a naive estimation, assuming a linear correspondence between the mass of the detected sample and the average number of detections, is bound to give an over estimation of the mass. Since most passive interrogation facilities are based on 3He detectors, the origin of the neutron cannot be determined by analyzing the energy spectrum (as all neutrons arrive at the detector in more or less the same energy), and a mathematical 'filter' is used to evaluate the noise to source ratio in the detection signal. The basic idea behind the mathematical filter is to utilize the fact that the different neutron sources have different statistical attributes- in particular, both the source event rate and the distribution of the number of neutrons released in each event differs between the different sources. There for, by studying the higher moments of the neutron population, new information about the source to noise ration may be obtained

  18. Measurement of uranium and plutonium in solid waste by passive photon or neutron counting and isotopic neutron source interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Crane, T.W.

    1980-03-01

    A summary of the status and applicability of nondestructive assay (NDA) techniques for the measurement of uranium and plutonium in 55-gal barrels of solid waste is reported. The NDA techniques reviewed include passive gamma-ray and x-ray counting with scintillator, solid state, and proportional gas photon detectors, passive neutron counting, and active neutron interrogation with neutron and gamma-ray counting. The active neutron interrogation methods are limited to those employing isotopic neutron sources. Three generic neutron sources (alpha-n, photoneutron, and /sup 252/Cf) are considered. The neutron detectors reviewed for both prompt and delayed fission neutron detection with the above sources include thermal (/sup 3/He, /sup 10/BF/sub 3/) and recoil (/sup 4/He, CH/sub 4/) proportional gas detectors and liquid and plastic scintillator detectors. The instrument found to be best suited for low-level measurements (< 10 nCi/g) is the /sup 252/Cf Shuffler. The measurement technique consists of passive neutron counting followed by cyclic activation using a /sup 252/Cf source and delayed neutron counting with the source withdrawn. It is recommended that a waste assay station composed of a /sup 252/Cf Shuffler, a gamma-ray scanner, and a screening station be tested and evaluated at a nuclear waste site. 34 figures, 15 tables.

  19. Radioactive waste package assay facility. Volume 2. Investigation of active neutron and active gamma interrogation

    International Nuclear Information System (INIS)

    Bailey, M.; Bunce, L.J.; Findlay, D.J.S.; Jolly, J.E.; Parsons, T.V.; Sene, M.R.; Swinhoe, M.T.

    1992-01-01

    Volume 2 of this report describes the theoretical and experimental work carried out at Harwell on active neutron and active gamma interrogation of 500 litre cemented intermediate level waste drums. The design of a suitable neutron generating target in conjunction with a LINAC was established. Following theoretical predictions of likely neutron responses, an experimental assay assembly was built. Responses were measured for simulated drums of ILW, based on CAGR, Magnox and PCM wastes. Good correlations were established between quantities of 235 -U, nat -U and D 2 O contained in the drums, and the neutron signals. Expected sensitivities are -1g of fissile actinide and -100g of total actinide. A measure of spatial distribution is obtainable. The neutron time spectra obtained during neutron interrogation were more complex than expected, and more analysis is needed. Another area of discrepancy is the difference between predicted and measured thermal neutron flux in the drum. Clusters of small 3 He proportional counters were found to be much superior for fast neutron detection than larger diameter counters. It is necessary to ensure constancy of electron beam position relative to target(s) and drum, and prudent to measure the target neutron or gamma output as appropriate. 59 refs., 77 figs., 11 tabs

  20. X-ray and neutron interrogation of air cargo for mobile applications

    Energy Technology Data Exchange (ETDEWEB)

    Van Liew, Seth

    2015-06-01

    A system for scanning break-bulk cargo for mobile applications is presented. This combines a 140 kV multi-view, multi-energy X-ray system with 2.5 MeV neutrons. The system uses dual energy X-ray radiography with neutron radiography. The X-ray and neutron systems were designed to be collocated in a mobile environment. Various materials were interrogated with the intent of distinguishing threat materials such as explosives from similar benign materials. In particular, the identification of threats and bengins with nearly identical effective atomic numbers has been demonstrated.

  1. X-ray and neutron interrogation of air cargo for mobile applications

    International Nuclear Information System (INIS)

    Van Liew, Seth

    2015-01-01

    A system for scanning break-bulk cargo for mobile applications is presented. This combines a 140 kV multi-view, multi-energy X-ray system with 2.5 MeV neutrons. The system uses dual energy X-ray radiography with neutron radiography. The X-ray and neutron systems were designed to be collocated in a mobile environment. Various materials were interrogated with the intent of distinguishing threat materials such as explosives from similar benign materials. In particular, the identification of threats and bengins with nearly identical effective atomic numbers has been demonstrated

  2. Fissile materials in solution concentration measured by active neutron interrogation; Mesure de concentration en matiere fissile dans les liquides par interrogation neutronique active

    Energy Technology Data Exchange (ETDEWEB)

    Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

    1993-12-31

    The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a {sup 252} Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.). 6 refs.

  3. Assay of fissionable isotopes in aqueous solution by pulsed neutron interrogation

    International Nuclear Information System (INIS)

    Campbell, P.; Gardy, E.M.; Boase, D.G.

    1978-04-01

    Non-destructive assay of uranium-235 and thorium-232 in aqueous nitric acid solutions has been accomplished by irradiation with pulses of neutrons from a 14-MeV Cockcroft-Walton neutron generator, and counting of the delayed neutrons emitted from the fissions induced. Design of the delayed neutron detector assemblies is described, together with the neutron pulse timing and counting systems. The effects of irradiation time, counting time, neutron moderation, detector design and sample geometry on the delayed neutron response from uranium-235 and 238 and thorium-232 are discussed. By using polyethylene to moderate the interrogating neutrons, solutions can be analyzed for both uranium-235 and thorium. Comparative analyses with chemical and γ-spectrometric methods show good agreement. The neutron method is rapid and is shown to be unaffected by the presence in solution of impurities such as iron, nickel, chromium, and aluminum. With the experimental equipment described, detection limits of 0.6 mg of 235 U and 9 mg of 232 Th in a sample volume of 25 mL have been achieved. Analyses of highly radioactive samples may be done easily since the measurements are not affected by the presence of large amounts of βγ radiation. Samples can be enclosed in small lead-shielded flasks during analysis to protect the analyst. The potential of the technique to on-line analysis applications is explored briefly. (author)

  4. Design of a novel instrument for active neutron interrogation of artillery shells.

    Science.gov (United States)

    Bélanger-Champagne, Camille; Vainionpää, Hannes; Peura, Pauli; Toivonen, Harri; Eerola, Paula; Dendooven, Peter

    2017-01-01

    The most common explosives can be uniquely identified by measuring the elemental H/N ratio with a precision better than 10%. Monte Carlo simulations were used to design two variants of a new prompt gamma neutron activation instrument that can achieve this precision. The instrument features an intense pulsed neutron generator with precise timing. Measuring the hydrogen peak from the target explosive is especially challenging because the instrument itself contains hydrogen, which is needed for neutron moderation and shielding. By iterative design optimization, the fraction of the hydrogen peak counts coming from the explosive under interrogation increased from [Formula: see text]% to [Formula: see text]% (statistical only) for the benchmark design. In the optimized design variants, the hydrogen signal from a high-explosive shell can be measured to a statistics-only precision better than 1% in less than 30 minutes for an average neutron production yield of 109 n/s.

  5. Design of a novel instrument for active neutron interrogation of artillery shells.

    Directory of Open Access Journals (Sweden)

    Camille Bélanger-Champagne

    Full Text Available The most common explosives can be uniquely identified by measuring the elemental H/N ratio with a precision better than 10%. Monte Carlo simulations were used to design two variants of a new prompt gamma neutron activation instrument that can achieve this precision. The instrument features an intense pulsed neutron generator with precise timing. Measuring the hydrogen peak from the target explosive is especially challenging because the instrument itself contains hydrogen, which is needed for neutron moderation and shielding. By iterative design optimization, the fraction of the hydrogen peak counts coming from the explosive under interrogation increased from [Formula: see text]% to [Formula: see text]% (statistical only for the benchmark design. In the optimized design variants, the hydrogen signal from a high-explosive shell can be measured to a statistics-only precision better than 1% in less than 30 minutes for an average neutron production yield of 109 n/s.

  6. High-fidelity MCNP modeling of a D-T neutron generator for active interrogation of special nuclear material

    International Nuclear Information System (INIS)

    Katalenich, Jeff; Flaska, Marek; Pozzi, Sara A.; Hartman, Michael R.

    2011-01-01

    Fast and robust methods for interrogation of special nuclear material (SNM) are of interest to many agencies and institutions in the United States. It is well known that passive interrogation methods are typically sufficient for plutonium identification because of a relatively high neutron production rate from 240 Pu . On the other hand, identification of shielded uranium requires active methods using neutron or photon sources . Deuterium-deuterium (2.45 MeV) and deuterium-tritium (14.1 MeV) neutron-generator sources have been previously tested and proven to be relatively reliable instruments for active interrogation of nuclear materials . In addition, the newest generators of this type are small enough for applications requiring portable interrogation systems. Active interrogation techniques using high-energy neutrons are being investigated as a method to detect hidden SNM in shielded containers . Due to the thickness of some containers, penetrating radiation such as high-energy neutrons can provide a potential means of probing shielded SNM. In an effort to develop the capability to assess the signal seen from various forms of shielded nuclear materials, University of Michigan Neutron Science Laboratory's D-T neutron generator and its shielding were accurately modeled in MCNP. The generator, while operating at nominal power, produces approximately 1x10 10 neutrons/s, a source intensity which requires a large amount of shielding to minimize the dose rates around the generator. For this reason, the existing shielding completely encompasses the generator and does not include beam ports. Therefore, several MCNP simulations were performed to estimate the yield of uncollided 14.1-MeV neutrons from the generator for active interrogation experiments. Beam port diameters of 5, 10, 15, 20, and 25 cm were modeled to assess the resulting neutron fluxes. The neutron flux outside the beam ports was estimated to be approximately 2x10 4 n/cm 2 s.

  7. APSTNG: Neutron interrogation for detection of nuclear and CW weapons, explosives, and drugs

    International Nuclear Information System (INIS)

    Rhodes, E.; Dickerman, C.E.; De Volpi, A.; Peters, C.W.

    1992-01-01

    A recently developed neutron diagnostic probe system has the potential to satisfy a significant number of van-mobile and fixed- portal requirements for nondestructive verification of sealed munitions and detection of contraband explosives and drugs. The probe is based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutrons generated from the deuterium-tritium reaction and that detects the alpha-particle associated with each neutron. Gamma-ray spectra of resulting neutron inelastic scattering and fission reactions identify nuclides associated with all major chemicals in chemical warfare agents, explosives, and drugs, as well as many pollutants and fissile and fertile special nuclear material. Flight times determined from determined from detection times of the gamma-rays and alpha-particles yield a separate tomographic image of each identified nuclide. The APSTNG also forms the basis for a compact fast-neutron transmission imaging system that can be used along with or instead of the emission imaging system; a collimator is not required since scattered neutrons are removed by ''electronic collimation'' (detected neutrons not having the proper flight time to be uncollided are discarded). The small and relatively inexpensive APSTNG exhibits high reliability and can be quickly replaced. Proof-of-concept experiments have been performed under laboratory conditions for simulated nuclear and chemical warfare munitions and for explosives and drugs

  8. Active interrogation using energetic protons

    International Nuclear Information System (INIS)

    Morris, Christopher L.; Chung, Kiwhan; Greene, Steven J.; Hogan, Gary E.; Makela, Mark; Mariam, Fesseha; Milner, Edward C.; Murray, Matthew; Saunders, Alexander; Spaulding, Randy; Wang, Zhehui; Waters, Laurie; Wysocki, Frederick

    2010-01-01

    Energetic proton beams provide an attractive alternative when compared to electromagnetic and neutron beams for active interrogation of nuclear threats because they have large fission cross sections, long mean free paths and high penetration, and they can be manipulated with magnetic optics. We have measured time-dependent cross sections and neutron yields for delayed neutrons and gamma rays using 800 MeV and 4 GeV proton beams with a set of bare and shielded targets. The results show significant signals from both unshielded and shielded nuclear materials. Measurements of neutron energies yield suggest a signature unique to fissile material. Results are presented in this paper.

  9. Ultraviolet Raman Spectral Signatures in Support of Lisa (Laser Interrogation of Surface Agents)

    National Research Council Canada - National Science Library

    Sedlacek, III, Arthur J; Finfrock, Charles C; Christesen, Steve; Chyba, Tom; Higdon, Scott

    2003-01-01

    ... (Laser Interrogation of Surface Agents). This engineering, testing and evaluation effort uses a novel mini-Raman lidar technique for on-the-move, short-range, non-contact detection and identification of chemical agents on the battlefield...

  10. APSTNG: Neutron interrogation for detection of explosives and drugs and nuclear and CW materials

    International Nuclear Information System (INIS)

    Rhodes, E.; Peters, C.W.

    1993-01-01

    A recently developed neutron diagnostic probe system has the potential to satisfy a significant number of van-mobile and fixed-portal requirements for nondestructive detection, including monitoring of contraband explosives, drugs, and weapon materials, and treaty verification of sealed munitions. The probe is based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutron generated from the deuterium-tritium reaction and that detects the alpha-particle associated with each neutron. Gamma-ray spectra of resulting neutron reactions identify nuclides associated with all major chemicals in explosives, drugs, and chemical warfare agents, as well as many pollutants and fissile and fertile special nuclear material. Flight times determined from detection times of the gamma rays and alpha-particles yield a separate coarse tomographic image of each identified nuclide. The APSTNG also forms the basis for a compact fast-neutron transmission imaging system that can be used along with or instead of the emission imaging system. Proof-of-concept experiments have been performed under laboratory conditions for simulated nuclear and chemical warfare munitions and for explosives and drugs. The small and relatively inexpensive APSTNG exhibits high reliability and can be quickly replaced. Surveillance systems based on APSTNG technology can avoid the large physical size, high capital and operating expenses, and reliability problems associated with complex accelerators

  11. Neutron absorbers and detector types for spent fuel verification using the self-interrogation neutron resonance densitometry

    International Nuclear Information System (INIS)

    Rossa, Riccardo; Borella, Alessandro; Labeau, Pierre-Etienne; Pauly, Nicolas; Meer, Klaas van der

    2015-01-01

    The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive non-destructive assay (NDA) technique that is proposed for the direct measurement of 239 Pu in a spent fuel assembly. The insertion of neutron detectors wrapped with different neutron absorbing materials, or neutron filters, in the central guide tube of a PWR fuel assembly is envisaged to measure the neutron flux in the energy region close to the 0.3 eV resonance of 239 Pu. In addition, the measurement of the fast neutron flux is foreseen. This paper is focused on the determination of the Gd and Cd neutron filters thickness to maximize the detection of neutrons within the resonance region. Moreover, several detector types are compared to identify the optimal condition and to assess the expected total neutron counts that can be obtained with the SINRD measurements. Results from Monte Carlo simulations showed that ranges between 0.1–0.3 mm and 0.5–1.0 mm ensure the optimal conditions for the Gd and Cd filters, respectively. Moreover, a 239 Pu fission chamber is better suited to measure neutrons close to the 0.3 eV resonance and it has the highest sensitivity to 239 Pu, in comparison with a 235 U fission chamber, with a 3 He proportional counter, and with a 10 B proportional counter. The use of a thin Gd filter and a thick Cd filter is suggested for the 239 Pu and 235 U fission chambers to increase the total counts achieved in a measurement, while a thick Gd filter and a thin Cd filter are envisaged for the 3 He and 10 B proportional counters to increase the sensitivity to 239 Pu. We concluded that an optimization process that takes into account measurement time, filters thickness, and detector size is needed to develop a SINRD detector that can meet the requirement for an efficient verification of spent fuel assemblies

  12. Unexploded Ordnance identification—A gamma-ray spectral analysis method for Carbon, Nitrogen and Oxygen signals following tagged neutron interrogation

    International Nuclear Information System (INIS)

    Mitra, S.; Dioszegi, I.

    2012-01-01

    A novel gamma-ray spectral analysis method has been demonstrated to optimally extract the signals of the signature elements of explosives, carbon (C), nitrogen (N) and oxygen (O) from 57–155 mm projectiles following tagged neutron interrogation with 14 MeV neutrons. The method was implemented on Monte Carlo simulated, synthetic spectra of Unexploded Ordnance (UXO) that contained high explosive fillers (Composition B, TNT or Explosive D) within steel casings of appropriate thicknesses. The analysis technique defined three broad regions-of-interest (ROI) between 4–7.5 MeV of a spectrum and from a system of three equations for the three unknowns namely C, N and O, the maximum counts from each of these elements were extracted. Unlike conventional spectral analysis techniques, the present method included the Compton continuum under a spectrum. For a neutron output of ∼2×10 7 ns −1 and using four 12.7 cm diameter×12.7 cm NaI(Tl) detectors, the C/N and C/O gamma-ray counts ratios of the explosive fillers were vastly different from that of an inert substance like sand. Conversion of the counts ratios to elemental ratios could further discriminate the different types of explosive fillers. The interrogation time was kept at ten minutes for each projectile.

  13. Serum microRNA signatures as "liquid biopsies" for interrogating hepatotoxic mechanisms and liver pathogenesis in human.

    Directory of Open Access Journals (Sweden)

    Julian Krauskopf

    Full Text Available MicroRNAs (miRNAs released into the peripheral circulation upon cellular injury have shown a promise as a new class of tissue-specific biomarkers. We were first to demonstrate that next-generation sequencing analysis of serum from human subjects with acetaminophen-induced liver injury revealed a specific signature of circulating miRNAs. We consequently hypothesized that different types of hepatic liver impairments might feature distinct signatures of circulating miRNAs and that this approach might be useful as minimally invasive diagnostic "liquid biopsies" enabling the interrogation of underlying molecular mechanisms of injury in distant tissues. Therefore we examined serum circulating miRNAs in a total of 72 serum samples from a group of 53 subjects that included patients with accidental acetaminophen overdose, hepatitis B infection, liver cirrhosis and type 2 diabetes as well as gender- and age-matched healthy subjects with no evidence of liver disease. The miRNA signatures were identified using next-generation sequencing that provided analysis for the whole miRNome, including miRNA isoforms. Compared to the healthy subjects, a total of 179 miRNAs showed altered serum levels across the diseased subjects. Although many subjects have elevated alanine aminotransferase suggesting liver impairments, we identified distinct miRNA signatures for different impairments with minimum overlap. Furthermore, the bioinformatics analysis of miRNA signatures revealed relevant molecular pathways associated with the mechanisms of toxicity and or pathogenesis of disease. Interestingly, the high proportion of miRNA isoforms present in the respective signatures indicated a new level of complexity in cellular response to stress or disease. Our study demonstrates for the first time that signatures of circulating miRNAs show specificity for liver injury phenotypes and, once validated, might become useful for diagnosis of organ pathologies as "liquid biopsies".

  14. Serum microRNA signatures as "liquid biopsies" for interrogating hepatotoxic mechanisms and liver pathogenesis in human.

    Science.gov (United States)

    Krauskopf, Julian; de Kok, Theo M; Schomaker, Shelli J; Gosink, Mark; Burt, Deborah A; Chandler, Patricia; Warner, Roscoe L; Johnson, Kent J; Caiment, Florian; Kleinjans, Jos C; Aubrecht, Jiri

    2017-01-01

    MicroRNAs (miRNAs) released into the peripheral circulation upon cellular injury have shown a promise as a new class of tissue-specific biomarkers. We were first to demonstrate that next-generation sequencing analysis of serum from human subjects with acetaminophen-induced liver injury revealed a specific signature of circulating miRNAs. We consequently hypothesized that different types of hepatic liver impairments might feature distinct signatures of circulating miRNAs and that this approach might be useful as minimally invasive diagnostic "liquid biopsies" enabling the interrogation of underlying molecular mechanisms of injury in distant tissues. Therefore we examined serum circulating miRNAs in a total of 72 serum samples from a group of 53 subjects that included patients with accidental acetaminophen overdose, hepatitis B infection, liver cirrhosis and type 2 diabetes as well as gender- and age-matched healthy subjects with no evidence of liver disease. The miRNA signatures were identified using next-generation sequencing that provided analysis for the whole miRNome, including miRNA isoforms. Compared to the healthy subjects, a total of 179 miRNAs showed altered serum levels across the diseased subjects. Although many subjects have elevated alanine aminotransferase suggesting liver impairments, we identified distinct miRNA signatures for different impairments with minimum overlap. Furthermore, the bioinformatics analysis of miRNA signatures revealed relevant molecular pathways associated with the mechanisms of toxicity and or pathogenesis of disease. Interestingly, the high proportion of miRNA isoforms present in the respective signatures indicated a new level of complexity in cellular response to stress or disease. Our study demonstrates for the first time that signatures of circulating miRNAs show specificity for liver injury phenotypes and, once validated, might become useful for diagnosis of organ pathologies as "liquid biopsies".

  15. Field Prototype of the ENEA Neutron Active Interrogation Device for the Detection of Dirty Bombs

    Directory of Open Access Journals (Sweden)

    Nadia Cherubini

    2016-10-01

    Full Text Available The Italian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA Neutron Active Interrogation (NAI device is a tool designed to improve CBRNE defense. It is designed to uncover radioactive and nuclear threats including those in the form of Improvised Explosive Devices (IEDs, the so-called “dirty bombs”. The NAI device, at its current development stage, allows to detect 6 g of 235U hidden in a package. It is easily transportable, light in weight, and with a real-time response. Its working principle is based on two stages: (1 an “active” stage in which neutrons are emitted by a neutron generator to interact with the item under inspection, and (2 a “passive” stage in which secondary neutrons are detected originating a signal that, once processed, allows recognition of the offence. In particular, a clear indication of the potential threat is obtained by a dedicated software based on the Differential Die-Away Time Analysis method.

  16. Diffuse neutron scattering signatures of rough films

    International Nuclear Information System (INIS)

    Pynn, R.; Lujan, M. Jr.

    1992-01-01

    Patterns of diffuse neutron scattering from thin films are calculated from a perturbation expansion based on the distorted-wave Born approximation. Diffuse fringes can be categorised into three types: those that occur at constant values of the incident or scattered neutron wavevectors, and those for which the neutron wavevector transfer perpendicular to the film is constant. The variation of intensity along these fringes can be used to deduce the spectrum of surface roughness for the film and the degree of correlation between the film's rough surfaces

  17. Development of neutron interrogation techniques for detection of hazardous substances in containers port

    International Nuclear Information System (INIS)

    D’Amico, N. M. B; Mayer, R.E; Tartaglione, A.

    2013-01-01

    This work is aimed at contributing to the effort of nations seeking to control international borders movement of dangerous chemical substances and nuclear material, in accordance with a multitude of agreements signed to that purpose. At this stage, we try to identify the signature of pure substances: chlorine (Cl), nitrogen (N), chromium (Cr), mercury (Hg), cadmium (Cd), uranium (U) y arsenic (As) and, later, to detect their presence in simulated large cargo containers. The technique employed in previous and in current work, consists in the detection of prompt and early decay gammas induced by incident thermal neutrons or fast neutrons thermalized in the cargo array. Uranium has also been detected through the counting of fast neutrons originated in induced fissions. (author)

  18. The Nuclear Car Wash: Neutron interrogation of cargo containers to detect hidden SNM

    Science.gov (United States)

    Hall, J. M.; Asztalos, S.; Biltoft, P.; Church, J.; Descalle, M.-A.; Luu, T.; Manatt, D.; Mauger, G.; Norman, E.; Petersen, D.; Pruet, J.; Prussin, S.; Slaughter, D.

    2007-08-01

    LLNL is actively involved in the development of advanced technologies for use in detecting threats in sea-going cargo containers, particularly the presence of hidden special nuclear materials (SNM). The "Nuclear Car Wash" (NCW) project presented here uses a high-energy (En ≈ 3.5-7.0 MeV) neutron probe to scan a container and then takes high-energy (Eγ ⩾ 2.5 MeV), β-delayed γ-rays emitted during the subsequent decay of any short-lived, neutron-induced fission products as a signature of fissionable material. The components of the proposed system (e.g. neutron source, gamma detectors, etc.) will be discussed along with data processing schemes, possible threat detection metrics and potential interference signals. Results from recent laboratory experiments using a prototype system at LLNL will also be presented.

  19. The Nuclear Car Wash: Neutron interrogation of cargo containers to detect hidden SNM

    International Nuclear Information System (INIS)

    Hall, J.M.; Asztalos, S.; Biltoft, P.; Church, J.; Descalle, M.-A.; Luu, T.; Manatt, D.; Mauger, G.; Norman, E.; Petersen, D.; Pruet, J.; Prussin, S.; Slaughter, D.

    2007-01-01

    LLNL is actively involved in the development of advanced technologies for use in detecting threats in sea-going cargo containers, particularly the presence of hidden special nuclear materials (SNM). The 'Nuclear Car Wash' (NCW) project presented here uses a high-energy (E n ∼ 3.5-7.0 MeV) neutron probe to scan a container and then takes high-energy (E γ ≥ 2.5 MeV), β-delayed γ-rays emitted during the subsequent decay of any short-lived, neutron-induced fission products as a signature of fissionable material. The components of the proposed system (e.g. neutron source, gamma detectors, etc.) will be discussed along with data processing schemes, possible threat detection metrics and potential interference signals. Results from recent laboratory experiments using a prototype system at LLNL will also be presented

  20. Neutron absorbers and detector types for spent fuel verification using the self-interrogation neutron resonance densitometry

    Energy Technology Data Exchange (ETDEWEB)

    Rossa, Riccardo, E-mail: rrossa@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium); Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Borella, Alessandro, E-mail: aborella@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium); Labeau, Pierre-Etienne, E-mail: pelabeau@ulb.ac.be [Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Pauly, Nicolas, E-mail: nipauly@ulb.ac.be [Université libre de Bruxelles, Ecole polytechnique de Bruxelles, Service de Métrologie Nucléaire (CP 165/84), Avenue F.D. Roosevelt, 50, B1050 Brussels (Belgium); Meer, Klaas van der, E-mail: kvdmeer@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang, 200, B2400 Mol (Belgium)

    2015-08-11

    The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive non-destructive assay (NDA) technique that is proposed for the direct measurement of {sup 239}Pu in a spent fuel assembly. The insertion of neutron detectors wrapped with different neutron absorbing materials, or neutron filters, in the central guide tube of a PWR fuel assembly is envisaged to measure the neutron flux in the energy region close to the 0.3 eV resonance of {sup 239}Pu. In addition, the measurement of the fast neutron flux is foreseen. This paper is focused on the determination of the Gd and Cd neutron filters thickness to maximize the detection of neutrons within the resonance region. Moreover, several detector types are compared to identify the optimal condition and to assess the expected total neutron counts that can be obtained with the SINRD measurements. Results from Monte Carlo simulations showed that ranges between 0.1–0.3 mm and 0.5–1.0 mm ensure the optimal conditions for the Gd and Cd filters, respectively. Moreover, a {sup 239}Pu fission chamber is better suited to measure neutrons close to the 0.3 eV resonance and it has the highest sensitivity to {sup 239}Pu, in comparison with a {sup 235}U fission chamber, with a {sup 3}He proportional counter, and with a {sup 10}B proportional counter. The use of a thin Gd filter and a thick Cd filter is suggested for the {sup 239}Pu and {sup 235}U fission chambers to increase the total counts achieved in a measurement, while a thick Gd filter and a thin Cd filter are envisaged for the {sup 3}He and {sup 10}B proportional counters to increase the sensitivity to {sup 239}Pu. We concluded that an optimization process that takes into account measurement time, filters thickness, and detector size is needed to develop a SINRD detector that can meet the requirement for an efficient verification of spent fuel assemblies.

  1. The simultaneous neutron and photon interrogation method for fissile and non-fissile element separation in radioactive waste drums

    International Nuclear Information System (INIS)

    Jallu, F.; Lyoussi, A.; Passard, C.; Payan, E.; Recroix, H.; Nurdin, G.; Buisson, A.; Allano, J.

    2000-01-01

    Measuring α-emitters such as ( 234,235,236,238 U, 238,239,240,242,244 Pu, 237 Np, 241,243 Am, ...), in solid radioactive waste allows us to quantify the α-activity in a drum and then to classify it. The simultaneous photon and neutron interrogation experiment (SIMPHONIE) method dealt with in this paper, combines both active neutron interrogation and induced photofission interrogation techniques simultaneously. Its purpose is to quantify fissile ( 235 U, 239,241 Pu, ...) and non-fissile ( 236,238 U, 238,240 Pu, ...) elements separately in only one measurement. This paper presents the principle of the method, the experimental setup, and the first experimental results obtained using the DGA/ETCA Linac and MiniLinatron pulsed linear electron accelerators located at Arcueil, France. First studies were carried out with U and Pu bare samples

  2. Confirmatory measurements of UF6 using the neutron self-interrogation method

    International Nuclear Information System (INIS)

    Stewart, J.E.; Ensslin, N.; Menlove, H.O.; Cowder, L.R.; Polk, P.J.

    1985-01-01

    A passive neutron counting method has been developed for measurement of the 235 U mass in Model 5A cylinders of UF 6 . The unique neutronic properties of UF 6 containing highly enriched uranium (HEU) permit 235 U assay using only passive neutron counting. The sample effectively assays itself by self-interrogation. Shipped from enrichment plants and received at fuel fabrication and conversion facilities, 5A UF 6 cylinders hold up to approx.17 kg of 235 U each. Field measurements at the Portsmouth Gaseous Diffusion Plant (GDP) showed an average assay accuracy of 6.8% (1sigma) for 44 cylinders with enrichments from 6 to 98% and with a range of fill heights. Further measurements on 38 cylinders containing 97%-enriched material yielded an accuracy of 2.8% (1sigma). Typical counting times for these measurements were less than 5 min. An in-plant instrument for receipts confirmation measurements of 5A UF 6 cylinders has been developed for the Savannah River Plant. The Receipts Assay Monitor (RAM) is currently being tested and calibrated. It is designed to confirm declared fissile mass in all incoming 5A cylinders containing HEU in the form of UF 6 . One of the computer-controlled features is a removable cadmium liner for the sample cavity. The liner allows a sample fill-height correction, which significantly improves assay accuracy

  3. Dose profile modeling of Idaho National Laboratory's active neutron interrogation laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Chichester, D.L. [Idaho National Laboratory, 2525 N. Fremont Avenue, Idaho Falls, ID 83415 (United States)], E-mail: david.chichester@inl.gov; Seabury, E.H.; Zabriskie, J.M.; Wharton, J.; Caffrey, A.J. [Idaho National Laboratory, 2525 N. Fremont Avenue, Idaho Falls, ID 83415 (United States)

    2009-06-15

    A new laboratory has been commissioned at Idaho National Laboratory for performing active neutron interrogation research and development. The facility is designed to provide radiation shielding for deuterium-tritium (DT) fusion (14.1 MeV) neutron generators (2x10{sup 8} n/s), deuterium-deuterium (DD) fusion (2.5 MeV) neutron generators (1x10{sup 7} n/s), and {sup 252}Cf spontaneous fission neutron sources (6.96x10{sup 7} n/s, 30 {mu}g). Shielding at the laboratory is comprised of modular concrete shield blocks 0.76 m thick with tongue-in-groove features to prevent radiation streaming, arranged into one small and one large test vault. The larger vault is designed to allow operation of the DT generator and has walls 3.8 m tall, an entrance maze, and a fully integrated electrical interlock system; the smaller test vault is designed for {sup 252}Cf and DD neutron sources and has walls 1.9 m tall and a simple entrance maze. Both analytical calculations and numerical simulations were used in the design process for the building to assess the performance of the shielding walls and to ensure external dose rates are within required facility limits. Dose rate contour plots have been generated for the facility to visualize the effectiveness of the shield walls and entrance mazes and to illustrate the spatial profile of the radiation dose field above the facility and the effects of skyshine around the vaults.

  4. Classifying threats with a 14-MeV neutron interrogation system.

    Science.gov (United States)

    Strellis, Dan; Gozani, Tsahi

    2005-01-01

    SeaPODDS (Sea Portable Drug Detection System) is a non-intrusive tool for detecting concealed threats in hidden compartments of maritime vessels. This system consists of an electronic neutron generator, a gamma-ray detector, a data acquisition computer, and a laptop computer user-interface. Although initially developed to detect narcotics, recent algorithm developments have shown that the system is capable of correctly classifying a threat into one of four distinct categories: narcotic, explosive, chemical weapon, or radiological dispersion device (RDD). Detection of narcotics, explosives, and chemical weapons is based on gamma-ray signatures unique to the chemical elements. Elements are identified by their characteristic prompt gamma-rays induced by fast and thermal neutrons. Detection of RDD is accomplished by detecting gamma-rays emitted by common radioisotopes and nuclear reactor fission products. The algorithm phenomenology for classifying threats into the proper categories is presented here.

  5. Detection of fission signatures induced by a low-energy neutron source

    International Nuclear Information System (INIS)

    Ocherashvili, A.; Becka, A.; Mayorovb, V.; Roesgen, E.; Crochemoreb, J.-M.; Mosconi, M.; Pedersen, B.; Heger, C.

    2015-01-01

    We present a method for the detection of special nuclear materials (SNM) in shielded containers which is both sensitive and applicable under field conditions. The method uses an external pulsed neutron source to induce fission in SNM and subsequent detection of the fast prompt fission neutrons. The detectors surrounding the container under investigation are liquid scintillation detectors able to distinguish gamma rays from fast neutrons by means of the pulse shape discrimination method (PSD). One advantage of these detectors, besides the ability for PSD analysis, is that the analogue signal from a detection event is of very short duration (typically few tens of nanoseconds). This allows the use of very short coincidence gates for the detection of the prompt fission neutrons in multiple detectors while benefiting from a low accidental (background) coincidence rate yielding a low detection limit. Another principle advantage of this method derives from the fact that the external neutron source is pulsed. By proper time gating the interrogation can be conducted by epithermal and thermal source neutrons only. These source neutrons do not appear in the fast neutron signal following the PSD analysis thus providing a fundamental method for separating the interrogating source neutrons from the sample response in form of fast fission neutrons. The paper describes laboratory tests with a configuration of eight detectors in the Pulsed Neutron Interrogation Test Assembly (PUNITA). The sensitivity of the coincidence signal to fissile mass is investigated for different sample configurations and interrogation regimes.

  6. Performance assessment of self-interrogation neutron resonance densitometry for spent nuclear fuel assay

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jianwei, E-mail: huj1@ornl.gov [Reactor and Nuclear Systems Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, PO Box 2008, MS-6172, Oak Ridge, TN 37831-6172 (United States); Tobin, Stephen J.; LaFleur, Adrienne M.; Menlove, Howard O.; Swinhoe, Martyn T. [Nuclear Engineering and Nonproliferation Division, Los Alamos National Laboratory (United States)

    2013-11-21

    Self-Interrogation Neutron Resonance Densitometry (SINRD) is one of several nondestructive assay (NDA) techniques being integrated into systems to measure spent fuel as part of the Next Generation Safeguards Initiative (NGSI) Spent Fuel Project. The NGSI Spent Fuel Project is sponsored by the US Department of Energy's National Nuclear Security Administration to measure plutonium in, and detect diversion of fuel pins from, spent nuclear fuel assemblies. SINRD shows promising capability in determining the {sup 239}Pu and {sup 235}U content in spent fuel. SINRD is a relatively low-cost and lightweight instrument, and it is easy to implement in the field. The technique makes use of the passive neutron source existing in a spent fuel assembly, and it uses ratios between the count rates collected in fission chambers that are covered with different absorbing materials. These ratios are correlated to key attributes of the spent fuel assembly, such as the total mass of {sup 239}Pu and {sup 235}U. Using count rate ratios instead of absolute count rates makes SINRD less vulnerable to systematic uncertainties. Building upon the previous research, this work focuses on the underlying physics of the SINRD technique: quantifying the individual impacts on the count rate ratios of a few important nuclides using the perturbation method; examining new correlations between count rate ratio and mass quantities based on the results of the perturbation study; quantifying the impacts on the energy windows of the filtering materials that cover the fission chambers by tallying the neutron spectra before and after the neutrons go through the filters; and identifying the most important nuclides that cause cooling-time variations in the count rate ratios. The results of these studies show that {sup 235}U content has a major impact on the SINRD signal in addition to the {sup 239}Pu content. Plutonium-241 and {sup 241}Am are the two main nuclides responsible for the variation in the count

  7. Design of a neutron interrogation cell based on an electron accelerator and performance assessment on 220 liter nuclear waste mock-up drums

    International Nuclear Information System (INIS)

    Sari, A.; Carrel, F.; Laine, F.; Lyoussi, A.

    2013-01-01

    Radiological characterization of nuclear waste drums is an important task for the nuclear industry. The amount of actinides, such as 235 U or 239 Pu, contained in a package can be determined using non-destructive active methods based on the fission process. One of these techniques, known as neutron interrogation, uses a neutron beam to induce fission reactions on the actinides. Optimization of the neutron flux is an important step towards improving this technique. Electron accelerators enable to achieve higher neutron flux intensities than the ones delivered by deuterium-tritium generators traditionally used on neutron interrogation industrial facilities. In this paper, we design a neutron interrogation cell based on an electron accelerator by MCNPX simulation. We carry out photoneutron interrogation measurements on uranium samples placed at the center of 220 liter nuclear waste drums containing different types of matrices. We quantify impact of the matrix on the prompt neutron signal, on the ratio between the prompt and delayed neutron signals, and on the interrogative neutron half-life time. We also show that characteristics of the conversion target of the electron accelerator enable to improve significantly measurement performances. (authors)

  8. Development of the QA/QC Procedures for a Neutron Interrogation System

    Energy Technology Data Exchange (ETDEWEB)

    Obhodas, Jasmina; Sudac, Davorin; Valkovic, Vladivoj [Ruder Boskovic Institute, 10000 Zagreb (Croatia)

    2015-07-01

    In order to perform QA/QC procedures for a system dedicated to the neutron interrogation of objects for the presence of threat materials one needs to perform measurements of reference materials (RM) having the same (or similar) atomic ratios as real materials. It is well known that explosives, drugs, and various other benign materials, contain chemical elements such as hydrogen, oxygen, carbon and nitrogen in distinctly different quantities. For example, a high carbon-to-oxygen ratio (C/O) is characteristic of drugs. Explosives can be differentiated by measurement of both C/O and nitrogen-to-oxygen (N/O) ratios. The C/N ratio of the chemical warfare agents, coupled with the measurement of elements such as fluorine and phosphorus, clearly differentiate them from the conventional explosives. Correlations between theoretical values and experimental results obtained in laboratory conditions for C/O and N/C ratios of simulants of hexogen (RDX), TNT, DLM2, TATP, cocaine, heroin, yperite, tetranitromethane, peroxide methylethyl-ketone, nitromethane and ethyleneglycol dinitrate are presented. (authors)

  9. Correcting the effects of the matrix using capture gamma-ray spectrometry: Application to measurement by Active Neutron Interrogation

    International Nuclear Information System (INIS)

    Baudry, G.

    2003-11-01

    In the field of the measurement of low masses of fissile material ( 235 U, 239 Pu, 241 Pu) in radioactive waste drums, the Active Neutron Interrogation is a non-destructive method achieving good results. It does however remain reliant upon uncertainties related to the matrix effects on interrogation and fission neutrons. The aim of this thesis is to develop a correction method able to take into account these matrix effects by quantifying the amount of absorbent materials (chlorine and hydrogen) in a 118- liter homogeneous matrix. The main idea is to use the gamma-ray spectrometry of gamma emitted by neutron captures to identify and quantify the composition of the matrix. An indicator from its chlorine content is then deduced in order to choose the calibration coefficient which best represents the real composition of the matrix. This document firstly presents the needs of control and characterization of radioactive objects, and the means used in the field of nuclear measurement. Emphases is put in particular on the Active Neutron Interrogation method. The matrices of interest are those made of light technological waste (density ≤ 0,4 g/cm 3 ) containing hydrogenated and chlorinated materials. The advantages of gamma-rays emitted by neutron captures for the determination of a chlorine content indicator of the matrices and the principles of the correction method are then explained. Measurements have been firstly realized with an existing Neutron Interrogation device (PROMETHEE 6). Such measurements have proven its inadequacy: no signal from the matrix hydrogen was detected, due to an intense signal from the polyethylene contained in some cell elements. Moreover, the matrix chlorine content appeared difficult to be measured. A new and specific device, named REGAIN and dedicated to active gamma-rays spectrometry, was defined with the Monte-Carlo N-Particle (MCNP) code. The experiments conducted with this new device made it possible to detect the hydrogen from the

  10. Neutron interrogator assay system for the Idaho Chemical Processing Plant waste canisters and spent fuel: preliminary description and operating procedures manual

    International Nuclear Information System (INIS)

    Menlove, H.O.; Eccleston, G.; Close, D.A.; Speir, L.G.

    1978-05-01

    A neutron interrogation assay system is being designed for the measurement of waste canisters and spent fuel packages at the new Idaho Chemical Processing Plant to be operated by Allied Chemical Corp. The assay samples consist of both waste canisters from the fluorinel dissolution process and spent fuel assemblies. The assay system is a 252 Cf ''Shuffler'' that employs a cyclic sequence of fast-neutron interrogation with a 252 Cf source followed by delayed-neutron counting to determine the 235 U content

  11. Analysis of experimental measurements of PWR fresh and spent fuel assemblies using Self-Interrogation Neutron Resonance Densitometry

    Energy Technology Data Exchange (ETDEWEB)

    LaFleur, Adrienne M., E-mail: alafleur@lanl.gov; Menlove, Howard O., E-mail: hmenlove@lanl.gov

    2015-05-01

    Self-Interrogation Neutron Resonance Densitometry (SINRD) is a new NDA technique that was developed at Los Alamos National Laboratory (LANL) to improve existing nuclear safeguards measurements for LWR fuel assemblies. The SINRD detector consists of four fission chambers (FCs) wrapped with different absorber filters to isolate different parts of the neutron energy spectrum and one ion chamber (IC) to measure the gross gamma rate. As a result, two different techniques can be utilized using the same SINRD detector unit and hardware. These techniques are the Passive Neutron Multiplication Counter (PNMC) method and the SINRD method. The focus of the work described in this paper is the analysis of experimental measurements of fresh and spent PWR fuel assemblies that were performed at LANL and the Korea Atomic Energy Research Institute (KAERI), respectively, using the SINRD detector. The purpose of these experiments was to assess the following capabilities of the SINRD detector: 1) reproducibility of measurements to quantify systematic errors, 2) sensitivity to water gap between detector and fuel assembly, 3) sensitivity and penetrability to the removal of fuel rods from the assembly, and 4) use of PNMC/SINRD ratios to quantify neutron multiplication and/or fissile content. The results from these simulations and measurements provide valuable experimental data that directly supports safeguards research and development (R&D) efforts on the viability of passive neutron NDA techniques and detector designs for partial defect verification of spent fuel assemblies. - Highlights: • Experimental measurements of PWR fresh and spent FAs were performed with SINRD. • Good agreement of MCNPX and measured results confirmed accuracy of SINRD model. • For fresh fuel, SINRD and PNMC ratios were not sensitive to water gaps of ≤5-mm. • Practical use of SINRD would be in Fork detector to reduce systematic uncertainties.

  12. On-line analysis of bulk materials using pulsed neutron interrogation

    International Nuclear Information System (INIS)

    Lebrun, P.; Tourneur, P. Le; Poumarede, B.; Bach, P.; Moeller, H.

    1999-01-01

    On the basis of our joint experience in neutronics for SODERN and in cement plant engineering for KRUPP POLYSIUS, we have developed a new on-line bulk materials analyser for the cement industry. This equipment includes a pulsed neutron generator GENIE 16, some gamma ray and neutron detectors, specially designed electronics with high counting rate, software delivering the mean elemental composition of raw material, and adequate shielding. This material is transported through the equipment on a conveyor belt, the size of which is adapted to the requirements. This paper briefly describes the equipment and some results, as obtained in dynamic test from a demonstrator installed in Germany

  13. On-line analysis of bulk materials using pulsed neutron interrogation

    Science.gov (United States)

    Lebrun, P.; Tourneur, P. Le; Poumarede, B.; Möller, H.; Bach, P.

    1999-06-01

    On the basis of our joint experience in neutronics for SODERN and in cement plant engineering for KRUPP POLYSIUS, we have developed a new on-line bulk materials analyser for the cement industry. This equipment includes a pulsed neutron generator GENIE 16, some gamma ray and neutron detectors, specially designed electronics with high counting rate, software delivering the mean elemental composition of raw material, and adequate shielding. This material is transported through the equipment on a conveyor belt, the size of which is adapted to the requirements. This paper briefly describes the equipment and some results, as obtained in dynamic test from a demonstrator installed in Germany.

  14. Application of active neutronic interrogation method to the line analysis in reprocessing plant

    International Nuclear Information System (INIS)

    Passard, C.

    1993-01-01

    In a reprocessing plant of irradiated spent fuels, the knowledge in real time (line analysis) of uranium and plutonium quantities present in solutions is an extremely important parameter to control the proceeding and for the apparatus safety. The active neutronic analysis give a nondestructive non intrusive and quick measure to know the concentrations. This method consists in inducing fissions in nuclides with a neutron source and then to detect the particles which come from

  15. Neutron interrogation systems using pyroelectric crystals and methods of preparation thereof

    Science.gov (United States)

    Tang, Vincent; Meyer, Glenn A.; Falabella, Steven; Guethlein, Gary; Rusnak, Brian; Sampayan, Stephen; Spadaccini, Christopher M.; Wang, Li-Fang; Harris, John; Morse, Jeff

    2017-08-01

    According to one embodiment, an apparatus includes a pyroelectric crystal, a deuterated or tritiated target, an ion source, and a common support coupled to the pyroelectric crystal, the deuterated or tritiated target, and the ion source. In another embodiment, a method includes producing a voltage of negative polarity on a surface of a deuterated or tritiated target in response to a temperature change of a pyroelectric crystal, pulsing a deuterium ion source to produce a deuterium ion beam, accelerating the deuterium ion beam to the deuterated or tritiated target to produce a neutron beam, and directing the ion beam onto the deuterated or tritiated target to make neutrons using a voltage of the pyroelectric crystal and/or an HGI surrounding the pyroelectric crystal. The directionality of the neutron beam is controlled by changing the accelerating voltage of the system. Other apparatuses and methods are presented as well.

  16. Determination of alpha activity and fissile mass content in solid waste by systems using neutron interrogation

    International Nuclear Information System (INIS)

    Romeyer Dherbey, J.; Lacruche, G.; Berne, R.; Auge, J.; Martin Deidier, L.; Butez, M.

    1990-01-01

    The Quantitative control (determination of heavy nuclides and alpha activity) of alpha radioactive wastes is necessary, particularly to determine if the waste is in accordance with the surface storage limits. In order to reduce the uncertainty on the alpha activity resulting from unknown isotopic composition, inhomogeneity of heavy nuclides in the matrix, combination of several methods is necessary. In the paper we present the Cadarache development work in the NDA of solid waste using the Californium shuffler, 14 Mev neutron generator, and also passive techniques such as neutron emission measurement and gamma spectrometry. Experimental systems combining active and passive methods are presented (COSAC, BANCO, DANAIDE, PROMETHEE)

  17. Dielectric RheoSANS - Simultaneous Interrogation of Impedance, Rheology and Small Angle Neutron Scattering of Complex Fluids.

    Science.gov (United States)

    Richards, Jeffrey J; Gagnon, Cedric V L; Krzywon, Jeffery R; Wagner, Norman J; Butler, Paul D

    2017-04-10

    A procedure for the operation of a new dielectric RheoSANS instrument capable of simultaneous interrogation of the electrical, mechanical and microstructural properties of complex fluids is presented. The instrument consists of a Couette geometry contained within a modified forced convection oven mounted on a commercial rheometer. This instrument is available for use on the small angle neutron scattering (SANS) beamlines at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR). The Couette geometry is machined to be transparent to neutrons and provides for measurement of the electrical properties and microstructural properties of a sample confined between titanium cylinders while the sample undergoes arbitrary deformation. Synchronization of these measurements is enabled through the use of a customizable program that monitors and controls the execution of predetermined experimental protocols. Described here is a protocol to perform a flow sweep experiment where the shear rate is logarithmically stepped from a maximum value to a minimum value holding at each step for a specified period of time while frequency dependent dielectric measurements are made. Representative results are shown from a sample consisting of a gel composed of carbon black aggregates dispersed in propylene carbonate. As the gel undergoes steady shear, the carbon black network is mechanically deformed, which causes an initial decrease in conductivity associated with the breaking of bonds comprising the carbon black network. However, at higher shear rates, the conductivity recovers associated with the onset of shear thickening. Overall, these results demonstrate the utility of the simultaneous measurement of the rheo-electro-microstructural properties of these suspensions using the dielectric RheoSANS geometry.

  18. Polarized X-Ray Emission from Magnetized Neutron Stars: Signature of Strong-Field Vacuum Polarization

    Science.gov (United States)

    Lai, Dong; Ho, Wynn C.

    2003-08-01

    In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

  19. Polarized x-ray emission from magnetized neutron stars: signature of strong-field vacuum polarization.

    Science.gov (United States)

    Lai, Dong; Ho, Wynn C G

    2003-08-15

    In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

  20. Simulated Performance of the Integrated Passive Neutron Albedo Reactivity and Self-Interrogation Neutron Resonance Densitometry Detector Designed for Spent Fuel Measurement at the Fugen Reactor in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, Timothy J. II [Los Alamos National Laboratory; Lafleur, Adrienne M. [Los Alamos National Laboratory; Menlove, Howard O. [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory; Seya, Michio [Los Alamos National Laboratory; Bolind, Alan M. [Los Alamos National Laboratory

    2012-07-16

    An integrated nondestructive assay instrument, which combined the Passive Neutron Albedo Reactivity (PNAR) and the Self-Interrogation Neutron Resonance Densitometry (SINRD) techniques, is the research focus for a collaborative effort between Los Alamos National Laboratory (LANL) and the Japanese Atomic Energy Agency as part of the Next Generation Safeguard Initiative. We will quantify the anticipated performance of this experimental system in two physical environments: (1) At LANL we will measure fresh Low Enriched Uranium (LEU) assemblies for which the average enrichment can be varied from 0.2% to 3.2% and for which Gd laced rods will be included. (2) At Fugen we will measure spent Mixed Oxide (MOX-B) and LEU spent fuel assemblies from the heavy water moderated Fugen reactor. The MOX-B assemblies will vary in burnup from {approx}3 GWd/tHM to {approx}20 GWd/tHM while the LEU assemblies ({approx}1.9% initial enrichment) will vary from {approx}2 GWd/tHM to {approx}7 GWd/tHM. The estimated count rates will be calculated using MCNPX. These preliminary results will help the finalization of the hardware design and also serve a guide for the experiment. The hardware of the detector is expected to be fabricated in 2012 with measurements expected to take place in 2012 and 2013. This work is supported by the Next Generation Safeguards Initiative, Office of Nuclear Safeguards and Security, National Nuclear Security Administration.

  1. Control of radioactive wastes and coupling of neutron/gamma measurements: use of radiative capture for the correction of matrix effects that penalize the fissile mass measurement by active neutron interrogation; Controle des dechets radioactifs et couplage de mesures neutron/gamma: exploitation de la capture radiative pour corriger les effets de matrice penalisant la mesure de la masse fissile par interrogation neutronique active

    Energy Technology Data Exchange (ETDEWEB)

    Loche, F

    2006-10-15

    In the framework of radioactive waste drums control, difficulties arise in the nondestructive measurement of fissile mass ({sup 235}U, {sup 239}Pu..) by Active Neutron Interrogation (ANI), when dealing with matrices containing materials (Cl, H...) influencing the neutron flux. The idea is to use the neutron capture reaction (n,{gamma}) to determine the matrix composition to adjust the ANI calibration coefficient value. This study, dealing with 118 litres, homogeneous drums of density less than 0,4 and composed of chlorinated and/or hydrogenated materials, leads to build abacus linking the {gamma} ray peak areas to the ANI calibration coefficient. Validation assays of these abacus show a very good agreement between the corrected and true fissile masses for hydrogenated matrices (max. relative standard deviation: 23 %) and quite good for chlorinated and hydrogenated matrices (58 %). The developed correction method improves the measured values. It may be extended to 0,45 density, heterogeneous drums. (author)

  2. High-sensitive detection by direct interrogation of 14 MeV Acc neutrons, (1). Uranium-contained metal matrix in a waste dram

    International Nuclear Information System (INIS)

    Haruyama, Mitsuo; Takase, Misao; Tobita, Hiroshi; Mori, Takamasa

    2004-01-01

    Previously, authors reported that the 14 MeV-neutron direct interrogation method has made possible measure for the discrimination of clearance levels of concrete solidification uranium waste. In this paper, applicability of the method to metal waste matrix is discussed based on the results of simulation experiments by the continuation energy Monte Carlo calculation code (MVP). The problem is that self-neutron moderation effect in a waste cannot be expected when a waste matrix is metal. To solve this, a moderator is adopted so as to surround a metal waste drum and to slow down suitably a 14 MeV neutrons. The simulation calculation showed that this effect is satisfactorily large. The detection limit of radioactivity concentration to 4.5% enriched uranium has been found to be 0.0973 Bq/g in the metal waste model of 215.59 kg gross weight, in which 61 pipes are stuffed into its drum. Moreover, the position-dependent sensitivity difference in a metal waste drum can be settled as small as to ±13.5%. In conclusion, it can be said that 14 MeV-neutron direct interrogation method can be applied to the waste of a metal system: the detection sensitivity is high enough and the position-dependent sensitivity difference is small admittedly. Hence the method can be applied also to discrimination measurement of the clearance level of metal uranium waste. (author)

  3. Gamma signatures of the C-BORD Tagged Neutron Inspection System

    Directory of Open Access Journals (Sweden)

    Sardet A.

    2018-01-01

    Full Text Available In the frame of C-BORD project (H2020 program of the EU, a Rapidly relocatable Tagged Neutron Inspection System (RRTNIS is being developed to non-intrusively detect explosives, chemical threats, and other illicit goods in cargo containers. Material identification is performed through gamma spectroscopy, using twenty NaI detectors and four LaBr3 detectors, to determine the different elements composing the inspected item from their specific gamma signatures induced by fast neutrons. This is performed using an unfolding algorithm to decompose the energy spectrum of a suspect item, selected by X-ray radiography and on which the RRTNIS inspection is focused, on a database of pure element gamma signatures. This paper reports on simulated signatures for the NaI and LaBr3 detectors, constructed using the MCNP6 code. First experimental spectra of a few elements of interest are also presented.

  4. Molecular signature of epistatic selection: interrogating genetic interactions in the sex-ratio meiotic drive of Drosophila simulans.

    Science.gov (United States)

    Chevin, Luis-Miguel; Bastide, Héloïse; Montchamp-Moreau, Catherine; Hospital, Frédéric

    2009-06-01

    Fine scale analyses of signatures of selection allow assessing quantitative aspects of a species' evolutionary genetic history, such as the strength of selection on genes. When several selected loci lie in the same genomic region, their epistatic interactions may also be investigated. Here, we study how the neutral polymorphism pattern was shaped by two close recombining loci that cause 'sex-ratio' meiotic drive in Drosophila simulans, as an example of strong selection with potentially strong epistasis. We compare the polymorphism data observed in a natural population with the results of forward stochastic simulations under several contexts of epistasis between the candidate loci for the drive. We compute the likelihood of different possible scenarios, in order to determine which configuration is most consistent with the data. Our results highlight that fine scale analyses of well-chosen candidate genomic regions provide information-rich data that can be used to investigate the genotype-phenotype-fitness map, which can hardly be studied in genome-wide analyses. We also emphasize that initial conditions and time of observation (here, time after the interruption of a partial selective sweep) are crucial parameters in the interpretation of real data, while these are often overlooked in theoretical studies.

  5. Signatures of Heavy Element Production in Neutron Star Mergers

    Science.gov (United States)

    Barnes, Jennifer

    2018-06-01

    Compact object mergers involving at least one neutron star have long been theorized to be sites of astrophysical nucleosynthesis via rapid neutron capture (the r-process). The observation in light and gravitational waves of the first neutron star merger (GW1701817) this past summer provided a stunning confirmation of this theory. Electromagnetic emission powered by the radioactive decay of freshly synthesized nuclei from mergers encodes information about the composition burned by the r-process, including whether a particular merger event synthesized the heaviest nuclei along the r-process path, or froze out at lower mass number. However, efforts to model the emission in detail must still contend with many uncertainties. For instance, the uncertain nuclear masses far from the valley of stability influence the final composition burned by the r-process, as will weak interactions operating in the merger’s immediate aftermath. This in turn can affect the color electromagnetic emission. Understanding the details of these transients’ spectra will also require a detailed accounting the electronic transitions of r-process elements and ions, in order to identify the strong transitions that underlie spectral formation. This talk will provide an overview of our current understanding of radioactive transients from mergers, with an emphasis on the role of experiment in providing critical inputs for models and reducing uncertainty.

  6. Monte carlo feasibility study of an active neutron assay technique for full-volume UF{sub 6} cylinder assay using a correlated interrogation source

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Karen A., E-mail: kamiller@lanl.gov [Los Alamos National Laboratory, Los Alamos, P.O. Box 1663 MS E540, NM 87545 (United States); Menlove, Howard O.; Swinhoe, Martyn T.; Marlow, Johnna B. [Los Alamos National Laboratory, Los Alamos, P.O. Box 1663 MS E540, NM 87545 (United States)

    2013-03-01

    Uranium cylinder assay plays an important role in the nuclear material accounting at gas centrifuge enrichment plants. The Passive Neutron Enrichment Meter (PNEM) was designed to determine uranium mass and enrichment in 30B and 48Y cylinders using total neutron and coincidence counting in the passive mode. 30B and 48Y cylinders are used to hold bulk UF{sub 6} feed, product, and tails at enrichment plants. In this paper, we report the results of a Monte-Carlo-based feasibility study for an active uranium cylinder assay system based on the PNEM design. There are many advantages of the active technique such as a shortened count time and a more direct measure of {sup 235}U content. The active system is based on a modified PNEM design and uses a {sup 252}Cf source as the correlated, active interrogation source. We show through comparison with a random AmLi source of equal strength how the use of a correlated driver significantly boosts the active signal and reduces the statistical uncertainty. We also discuss ways in which an active uranium cylinder assay system can be optimized to minimize background from {sup 238}U fast-neutron induced fission and direct counts from the interrogation source.

  7. Aerial Neutron Detection: Neutron Signatures for Nonproliferation and Emergency Response Applications

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Richard J.; Stampahar, Thomas G.; Smith, Ethan X.; Mukhopadhyay, Sanjoy; Wolff, Ronald S.; Rourke, Timothy J.; LeDonne, Jeffrey P.; Avaro, Emanuele; Butler, D. Andre; Borders, Kevin L.; Stampahar, Jezabel; Schuck, William H.; Selfridge, Thomas L.; McKissack, Thomas M.; Duncan, William W.; Hendricks, Thane J.

    2012-10-17

    From 2007 to the present, the Remote Sensing Laboratory has been conducting a series of studies designed to expand our fundamental understanding of aerial neutron detection with the goal of designing an enhanced sensitivity detection system for long range neutron detection. Over 35 hours of aerial measurements in a helicopter were conducted for a variety of neutron emitters such as neutron point sources, a commercial nuclear power reactor, nuclear reactor spent fuel in dry cask storage, depleted uranium hexafluoride and depleted uranium metal. The goals of the project were to increase the detection sensitivity of our instruments such that a 5.4 × 104 neutron/second source could be detected at 100 feet above ground level at a speed of 70 knots and to enhance the long-range detection sensitivity for larger neutron sources, i.e., detection ranges above 1000 feet. In order to increase the sensitivity of aerial neutron detection instruments, it is important to understand the dynamics of the neutron background as a function of altitude. For aerial neutron detection, studies have shown that the neutron background primarily originates from above the aircraft, being produced in the upper atmosphere by galactic cosmic-ray interactions with air molecules. These interactions produce energetic neutrons and charged particles that cascade to the earth’s surface, producing additional neutrons in secondary collisions. Hence, the neutron background increases as a function of altitude which is an impediment to long-range neutron detection. In order to increase the sensitivity for long range detection, it is necessary to maintain a low neutron background as a function of altitude. Initial investigations show the variation in the neutron background can be decreased with the application of a cosmic-ray shield. The results of the studies along with a representative data set are presented.

  8. Analysis of an indirect neutron signature for enhanced UF_6 cylinder verification

    International Nuclear Information System (INIS)

    Kulisek, J.A.; McDonald, B.S.; Smith, L.E.; Zalavadia, M.A.; Webster, J.B.

    2017-01-01

    The International Atomic Energy Agency (IAEA) currently uses handheld gamma-ray spectrometers combined with ultrasonic wall-thickness gauges to verify the declared enrichment of uranium hexafluoride (UF_6) cylinders. The current method provides relatively low accuracy for the assay of "2"3"5U enrichment, especially for natural and depleted UF_6. Furthermore, the current method provides no capability to assay the absolute mass of "2"3"5U in the cylinder due to the localized instrument geometry and limited penetration of the 186-keV gamma-ray signature from "2"3"5U. Also, the current verification process is a time-consuming component of on-site inspections at uranium enrichment plants. Toward the goal of a more-capable cylinder assay method, the Pacific Northwest National Laboratory has developed the hybrid enrichment verification array (HEVA). HEVA measures both the traditional 186-keV direct signature and a non-traditional, high-energy neutron-induced signature (HEVA_N_T). HEVA_N_T enables full-volume assay of UF_6 cylinders by exploiting the relatively larger mean free paths of the neutrons emitted from the UF_6. In this work, Monte Carlo modeling is used as the basis for characterizing HEVA_N_T in terms of the individual contributions to HEVA_N_T from nuclides and hardware components. Monte Carlo modeling is also used to quantify the intrinsic efficiency of HEVA for neutron detection in a cylinder-assay geometry. Modeling predictions are validated against neutron-induced gamma-ray spectra from laboratory measurements and a relatively large population of Type 30B cylinders spanning a range of enrichments. Implications of the analysis and findings on the viability of HEVA for cylinder verification are discussed, such as the resistance of the HEVA_N_T signature to manipulation by the nearby placement of neutron-conversion materials.

  9. Analysis of an indirect neutron signature for enhanced UF{sub 6} cylinder verification

    Energy Technology Data Exchange (ETDEWEB)

    Kulisek, J.A., E-mail: Jonathan.Kulisek@pnnl.gov; McDonald, B.S.; Smith, L.E.; Zalavadia, M.A.; Webster, J.B.

    2017-02-21

    The International Atomic Energy Agency (IAEA) currently uses handheld gamma-ray spectrometers combined with ultrasonic wall-thickness gauges to verify the declared enrichment of uranium hexafluoride (UF{sub 6}) cylinders. The current method provides relatively low accuracy for the assay of {sup 235}U enrichment, especially for natural and depleted UF{sub 6}. Furthermore, the current method provides no capability to assay the absolute mass of {sup 235}U in the cylinder due to the localized instrument geometry and limited penetration of the 186-keV gamma-ray signature from {sup 235}U. Also, the current verification process is a time-consuming component of on-site inspections at uranium enrichment plants. Toward the goal of a more-capable cylinder assay method, the Pacific Northwest National Laboratory has developed the hybrid enrichment verification array (HEVA). HEVA measures both the traditional 186-keV direct signature and a non-traditional, high-energy neutron-induced signature (HEVA{sub NT}). HEVA{sub NT} enables full-volume assay of UF{sub 6} cylinders by exploiting the relatively larger mean free paths of the neutrons emitted from the UF{sub 6}. In this work, Monte Carlo modeling is used as the basis for characterizing HEVA{sub NT} in terms of the individual contributions to HEVA{sub NT} from nuclides and hardware components. Monte Carlo modeling is also used to quantify the intrinsic efficiency of HEVA for neutron detection in a cylinder-assay geometry. Modeling predictions are validated against neutron-induced gamma-ray spectra from laboratory measurements and a relatively large population of Type 30B cylinders spanning a range of enrichments. Implications of the analysis and findings on the viability of HEVA for cylinder verification are discussed, such as the resistance of the HEVA{sub NT} signature to manipulation by the nearby placement of neutron-conversion materials.

  10. Epithermal interrogation of fissile waste

    International Nuclear Information System (INIS)

    Coop, K.L.; Hollas, C.L.

    1996-01-01

    Self-shielding of interrogating thermal neutrons in lumps of fissile material can be a major source of error in transuranic waste assay using the widely employed differential dieaway technique. We are developing a new instrument, the combined thermal/epithermal neutron (CTEN) interrogation instrument to detect the occurrence of self- shielding and mitigate its effects. Neutrons are moderated in the graphite walls of the CTEN instrument to provide an interrogating flux of epithermal and thermal neutrons. The induced prompt fission neutrons are detected in proportional counters. We report the results of measurements made with the CTEN instrument, using minimal and highly self-shielding plutonium and uranium sources in 55 gallon drums containing a variety of mock waste matrices. Fissile isotopes and waste forms for which the method is most applicable, and limitations associated with the hydrogen content of the waste package/matrix are described

  11. Simultaneous photon and neutron interrogation using an electron accelerator in order to quantify actinides in encapsulated radioactive wastes; Double interrogation simultanee neutrons et photons utilisant un accelerateur d'electrons pour la caracterisation separee des actinides dans les dechets radioactifs enrobes

    Energy Technology Data Exchange (ETDEWEB)

    Jallu, F

    1999-09-24

    Measuring out alpha emitters, such as ({sup 234,235,236,238}U {sup 238,239,240,242,}2{sup 44P}u, {sup 237}Np {sup 241,243}Am...), in solid radioactive waste, allows us to quantify the alpha activity in a drum and then to classify it. The SIMPHONIE (SIMultaneous PHOton and Neutron Interrogation Experiment) method, developed in this Ph.D. work, combines both the Active Neutron Interrogation and the Induced Photofission Interrogation techniques simultaneously. Its purpose is to quantify in only one measurement, fissile ({sup 235}U, {sup 239,241}Pu...) and fertile ({sup 236,238}U, {sup 238,240}Pu...) elements separately. In the first chapter of this Ph.D. report, we present the principle of the Radioactive Waste Management in France. The second chapter deals with the physical properties of neutron fission and of photofission. These two nuclear reactions are the basis of the SIMPHONIE method. Moreover, one of our purposes was to develop the ELEPHANT (ELEctron PHoton And Neutron Transport) code in view to simulate the electron, photon and neutron transport, including the ({gamma}, n), ({gamma}, 2n) and ({gamma}, f) photonuclear reactions that are not taken into account in the MCNP4 (Monte Carlo N-Particle) code. The simulation codes developed and used in this work are detailed in the third chapter. Finally, the fourth chapter gives the experimental results of SIMPHONIE obtained by using the DGA/ETCA electron linear accelerators located at Arcueil, France. Fissile ({sup 235}U, {sup 239}Pu) and fertile ({sup 238}U) samples were studied. Furthermore, comparisons between experimental results and calculated data of photoneutron production in tungsten, copper, praseodymium and beryllium by using an electron LINear Accelerator (LINAC) are given. This allows us to evaluate the validity degree of the ELEPHANT code, and finally the feasibility of the SIMPHONIE method. (author)

  12. Study and development of a method allowing the identification of actinides inside nuclear waste packages, by active neutron or photon interrogation and delayed gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Carrel, F.

    2007-10-01

    An accurate estimation of the alpha-activity of a nuclear waste package is necessary to select the best mode of storage. The main purpose of this work is to develop a non-destructive active method, based on the fission process and allowing the identification of actinides ( 235 U, 238 U, 239 Pu). These three elements are the main alpha emitters contained inside a package. Our technique is based on the detection of delayed gammas emitted by fission products. These latter are created by irradiation with the help of a neutron or photon beam. Performances of this method have been investigated after an Active Photon or Neutron Interrogation (INA or IPA). Three main objectives were fixed in the framework of this thesis. First, we measured many yields of photofission products to compensate the lack of data in the literature. Then, we studied experimental performances of this method to identify a given actinide ( 239 Pu in fission, 235 U in photofission) present in an irradiated mixture. Finally, we assessed the application of this technique on different mock-up packages for both types of interrogation (118 l mock-up package containing EVA in fission, 220 l mock-up package with a wall of concrete in photofission). (author)

  13. A new method to measure the U-235 content in fresh LWR fuel assemblies via fast-neutron passive self-interrogation

    Science.gov (United States)

    Menlove, Howard; Belian, Anthony; Geist, William; Rael, Carlos

    2018-01-01

    The purpose of this paper is to provide a solution to a decades old safeguards problem in the verification of the fissile concentration in fresh light water reactor (LWR) fuel assemblies. The problem is that the burnable poison (e.g. Gd2O3) addition to the fuel rods decreases the active neutron assay for the fuel assemblies. This paper presents a new innovative method for the verification of the 235U linear mass density in fresh LEU fuel assemblies that is insensitive to the burnable poison content. The technique makes use of the 238U atoms in the fuel rods to self-interrogate the 235U mass. The innovation for the new approach is that the 238U spontaneous fission (SF) neutrons from the rods induces fission reactions (IF) in the 235U that are time correlated with the SF source neutrons. Thus, the coincidence gate counting rate benefits from both the nu-bar of the 238U SF (2.07) and the 235U IF (2.44) for a fraction of the IF reactions. Whereas, the 238U SF background has no time-correlation boost. The higher the detection efficiency, the higher the correlated boost because background neutron counts from the SF are being converted to signal doubles. This time-correlation in the IF signal increases signal/background ratio that provides a good precision for the net signal from the 235U mass. The hard neutron energy spectrum makes the technique insensitive to the burnable poison loading where a Cd or Gd liner on the detector walls is used to prevent thermal-neutron reflection back into the fuel assembly from the detector. We have named the system the fast-neutron passive collar (FNPC).

  14. Control of radioactive wastes and coupling of neutron/gamma measurements: use of radiative capture for the correction of matrix effects that penalize the fissile mass measurement by active neutron interrogation

    International Nuclear Information System (INIS)

    Loche, F.

    2006-10-01

    In the framework of radioactive waste drums control, difficulties arise in the nondestructive measurement of fissile mass ( 235 U, 239 Pu..) by Active Neutron Interrogation (ANI), when dealing with matrices containing materials (Cl, H...) influencing the neutron flux. The idea is to use the neutron capture reaction (n,γ) to determine the matrix composition to adjust the ANI calibration coefficient value. This study, dealing with 118 litres, homogeneous drums of density less than 0,4 and composed of chlorinated and/or hydrogenated materials, leads to build abacus linking the γ ray peak areas to the ANI calibration coefficient. Validation assays of these abacus show a very good agreement between the corrected and true fissile masses for hydrogenated matrices (max. relative standard deviation: 23 %) and quite good for chlorinated and hydrogenated matrices (58 %). The developed correction method improves the measured values. It may be extended to 0,45 density, heterogeneous drums. (author)

  15. Detection of chemical explosives using multiple photon signatures

    International Nuclear Information System (INIS)

    Loschke, K.W.; Dunn, W.L.

    2008-01-01

    Full text: A template-matching procedure to aid in rapid detection of improvised explosive devices (IEDs) is being investigated. Multiple photon-scattered and photon-induced positron annihilation radiation responses are being used as part of a photon-neutron signature-based radiation scanning (SBRS) approach (see companion reference for description of the neutron component), in an attempt to detect chemical explosives at safe standoff distances. Many past and present photon interrogation methods are based on imaging. Imaging techniques seek to determine at high special resolution the internal structure of a target of interest. Our technique simply seeks to determine if an unknown target contains a detectable amount of chemical explosives by comparing multiple responses (signatures) that depend on both density and composition of portions of a target. In the photon component, beams of photons are used to create back-streaming signatures, which are dependent on the density and composition of part of the target being interrogated. These signatures are compared to templates, which are collections of the same signatures if the interrogated volume contained a significant amount of explosives. The signature analysis produces a figure-of-merit and a standard deviation of the figure-of-merit. These two metrics are used to filter safe from dangerous targets. Experiments have been conducted that show that explosive surrogates (fertilizers) can be distinguished from several inert materials using these photon signatures, demonstrating that these signatures can be used effectively to help IEDs

  16. INL Active Interrogation Testing In Support of the GNEP Safeguards Campaign

    International Nuclear Information System (INIS)

    David L. Chichester

    2008-01-01

    Active interrogation, a measurement technique which uses a radiation source to probe materials and generate unique signatures useful for characterizing those materials, is a powerful tool for assaying special nuclear material. Work at Idaho National Laboratory (INL) in the area of active interrogation, using neutron and photon sources, has been under way for many years to develop methods for detecting and quantifying nuclear material for national and homeland security research areas. This research knowledge base is now being extended to address nuclear safeguards and process monitoring issues related to the Global Nuclear Energy Partnership (GNEP). As a first step in this area preliminary scoping studies have been performed to investigate the usefulness of using active neutron interrogation, with a low-power electronic neutron generator, to assay Department of Transportation 6M shipping drums containing uranium oxide fuel rodlets from INL's zero power physics reactor. Using the paired-counting technique during the die-away time period of interrogation, a lower detection limit of approximately 4.2 grams of enriched uranium (40% 235U) was calculated for a 40 minute measurement using a field portable 2.5 MeV neutron source and an array of 16 moderated helium-3 neutron tubes. Future work in this area, including the use of a more powerful neutron source and a better tailored detector array, would likely improve this limit to a much lower level. Further development work at INL will explore the applicability of active interrogation in association with the nuclear safeguards and process monitoring needs of the advanced GNEP facilities under consideration. This work, which will include both analyses and field demonstrations, will be performed in collaboration with colleagues at INL and elsewhere that have expertise in nuclear fuel reprocessing as well as active interrogation and its use for nuclear material analyses

  17. Source Correlated Prompt Neutron Activation Analysis for Material Identification and Localization

    Science.gov (United States)

    Canion, Bonnie; McConchie, Seth; Landsberger, Sheldon

    2017-07-01

    This paper investigates the energy spectrum of photon signatures from an associated particle imaging deuterium tritium (API-DT) neutron generator interrogating shielded uranium. The goal is to investigate if signatures within the energy spectrum could be used to indirectly characterize shielded uranium when the neutron signature is attenuated. By utilizing the correlated neutron cone associated with each pixel of the API-DT neutron generator, certain materials can be identified and located via source correlated spectrometry of prompt neutron activation gamma rays. An investigation is done to determine if fission neutrons induce a significant enough signature within the prompt neutron-induced gamma-ray energy spectrum in shielding material to be useful for indirect nuclear material characterization. The signature deriving from the induced fission neutrons interacting with the shielding material was slightly elevated in polyethylene-shielding depleted uranium (DU), but was more evident in some characteristic peaks from the aluminum shielding surrounding DU.

  18. A programme for Euratom safeguards inspectors, used in the assay of high enriched (H.E.U.) and low enriched (L.E.U.) uranium fuel materials by active neutron interrogation

    International Nuclear Information System (INIS)

    Vocino, V.; Farese, N.; Maucq, T.; Nebuloni, M.

    1991-01-01

    The programme AECC (Active Euratom Coincidence Counters) has been developed at the Joint Research Center, Ispra by the Euratom Safeguards Directorate, Luxembourg and the Safety Technology Institute, Ispra for the acquisition, evaluation, management and storage of measurement data originating from active neutron interrogation of HEU and LEU fuel materials. The software accommodates the implementation of the NDA (Non Destructive Assay) procedures for the Active Well Coincidence Counters and Active Neutron Coincidence Counters deployed by the Euratom Safeguards Directorate, Luxembourg

  19. Californium interrogation prompt neutron (CIPN) instrument for non-destructive assay of spent nuclear fuel—Design concept and experimental demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Henzlova, D., E-mail: henzlova@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Menlove, H.O.; Rael, C.D.; Trellue, H.R.; Tobin, S.J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Park, Se-Hwan; Oh, Jong-Myeong; Lee, Seung-Kyu; Ahn, Seong-Kyu; Kwon, In-Chan; Kim, Ho-Dong [Korea Atomic Energy Research Institute, Daejeong (Korea, Republic of)

    2016-01-11

    This paper presents results of the first experimental demonstration of the Californium Interrogation Prompt Neutron (CIPN) instrument developed within a multi-year effort launched by the Next Generation Safeguards Initiative Spent Fuel Project of the United States Department of Energy. The goals of this project focused on developing viable non-destructive assay techniques with capabilities to improve an independent verification of spent fuel assembly characteristics. For this purpose, the CIPN instrument combines active and passive neutron interrogation, along with passive gamma-ray measurements, to provide three independent observables. This paper describes the initial feasibility demonstration of the CIPN instrument, which involved measurements of four pressurized-water-reactor spent fuel assemblies with different levels of burnup and two initial enrichments. The measurements were performed at the Post-Irradiation Examination Facility at the Korea Atomic Energy Institute in the Republic of Korea. The key aim of the demonstration was to evaluate CIPN instrument performance under realistic deployment conditions, with the focus on a detailed assessment of systematic uncertainties that are best evaluated experimentally. The measurements revealed good positioning reproducibility, as well as a high degree of insensitivity of the CIPN instrument's response to irregularities in a radial burnup profile. Systematic uncertainty of individual CIPN instrument signals due to assembly rotation was found to be <4.5%, even for assemblies with fairly extreme gradients in the radial burnup profile. These features suggest that the CIPN instrument is capable of providing a good representation of assembly average characteristics, independent of assembly orientation in the instrument.

  20. Californium interrogation prompt neutron (CIPN) instrument for non-destructive assay of spent nuclear fuel—Design concept and experimental demonstration

    International Nuclear Information System (INIS)

    Henzlova, D.; Menlove, H.O.; Rael, C.D.; Trellue, H.R.; Tobin, S.J.; Park, Se-Hwan; Oh, Jong-Myeong; Lee, Seung-Kyu; Ahn, Seong-Kyu; Kwon, In-Chan; Kim, Ho-Dong

    2016-01-01

    This paper presents results of the first experimental demonstration of the Californium Interrogation Prompt Neutron (CIPN) instrument developed within a multi-year effort launched by the Next Generation Safeguards Initiative Spent Fuel Project of the United States Department of Energy. The goals of this project focused on developing viable non-destructive assay techniques with capabilities to improve an independent verification of spent fuel assembly characteristics. For this purpose, the CIPN instrument combines active and passive neutron interrogation, along with passive gamma-ray measurements, to provide three independent observables. This paper describes the initial feasibility demonstration of the CIPN instrument, which involved measurements of four pressurized-water-reactor spent fuel assemblies with different levels of burnup and two initial enrichments. The measurements were performed at the Post-Irradiation Examination Facility at the Korea Atomic Energy Institute in the Republic of Korea. The key aim of the demonstration was to evaluate CIPN instrument performance under realistic deployment conditions, with the focus on a detailed assessment of systematic uncertainties that are best evaluated experimentally. The measurements revealed good positioning reproducibility, as well as a high degree of insensitivity of the CIPN instrument's response to irregularities in a radial burnup profile. Systematic uncertainty of individual CIPN instrument signals due to assembly rotation was found to be <4.5%, even for assemblies with fairly extreme gradients in the radial burnup profile. These features suggest that the CIPN instrument is capable of providing a good representation of assembly average characteristics, independent of assembly orientation in the instrument.

  1. Discrimination of ex-core neutron noise signatures using artificial neural networks

    International Nuclear Information System (INIS)

    Alguindigue, I.E.; Uhrig, R.E.; Cai, M.; Trenty, A.

    1993-01-01

    The vibratory behavior of the internals in a Pressurized Water Reactor, PWR, can be identified and monitored using ex-core neutron noise data from power detectors located at ionization chambers outside the vessel. The signatures collected from these sensors provide information regarding presence of contacts between the core barrel and the pressure vessel, and more importantly, a means of verifying the integrity of components in the system. This report describes a neural-network-based methodology for identifying the vibration mode of the core barrel, and for detecting a particular family of mechanical failures. Features are extracted from the neutron noise spectra and used for training neural network models to identify the different states of vibratory behavior typically exhibited by PWR'S. The technique was tested on data from twenty eight 900MW pressurized water reactors in France, and the results achieved are over 98% accurate

  2. A programme for Euratom safeguards inspectors, used in the assay of plutonium bearing materials by passive neutron interrogation

    International Nuclear Information System (INIS)

    Vocino, V.; Farese, N.; Maucq, T.; Nebuloni, M.

    1991-01-01

    The programme PECC (Passive Euratom Coincidence Counters) has been developed at the Joint Research Center, Ispra by the Euratom Safeguards Directorate, Luxembourg and the Safety Technology Institute, Ispra for the acquisition, evaluation, management and storage of measurements data originating from passive neutron assay of plutonium bearing materials. The software accommodates the implementation of the NDA (Non Destructive Assay) procedures for all types of passive neutron coincidence deployed by the Euratom Safeguards Directorate, Luxembourg

  3. Development of Neutron Energy Spectral Signatures for Passive Monitoring of Spent Nuclear Fuels in Dry Cask Storage

    Science.gov (United States)

    Harkness, Ira; Zhu, Ting; Liang, Yinong; Rauch, Eric; Enqvist, Andreas; Jordan, Kelly A.

    2018-01-01

    Demand for spent nuclear fuel dry casks as an interim storage solution has increased globally and the IAEA has expressed a need for robust safeguards and verification technologies for ensuring the continuity of knowledge and the integrity of radioactive materials inside spent fuel casks. Existing research has been focusing on "fingerprinting" casks based on count rate statistics to represent radiation emission signatures. The current research aims to expand to include neutron energy spectral information as part of the fuel characteristics. First, spent fuel composition data are taken from the Next Generation Safeguards Initiative Spent Fuel Libraries, representative for Westinghouse 17ˣ17 PWR assemblies. The ORIGEN-S code then calculates the spontaneous fission and (α,n) emissions for individual fuel rods, followed by detailed MCNP simulations of neutrons transported through the fuel assemblies. A comprehensive database of neutron energy spectral profiles is to be constructed, with different enrichment, burn-up, and cooling time conditions. The end goal is to utilize the computational spent fuel library, predictive algorithm, and a pressurized 4He scintillator to verify the spent fuel assemblies inside a cask. This work identifies neutron spectral signatures that correlate with the cooling time of spent fuel. Both the total and relative contributions from spontaneous fission and (α,n) change noticeably with respect to cooling time, due to the relatively short half-life (18 years) of the major neutron source 244Cm. Identification of this and other neutron spectral signatures allows the characterization of spent nuclear fuels in dry cask storage.

  4. Applications of the associated-particle neutron-time-of-flight interrogation technique - From sheep to unexploded ordnance

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, S. [Environmental Sciences Department, Brookhaven National Laboratory, Upton, NY 11973 and Nuclear Forensics R and D, Sandia National Laboratories, Albuquerque, NM 87185-0968 (United States)

    2013-04-19

    The associated-particle technique (APT) will be presented for some diverse applications that include on the one hand, analyzing the body composition of live sheep and on the other, identifying the fillers of unexploded ordnance (UXO). What began with proof-of-concept studies using a large laboratory based 14 MeV neutron generator of the 'associated-particle' type, soon became possible for the first time to measure total body protein, fat and water simultaneously in live sheep using a compact field deployable associated-particle sealed-tube neutron generator (APSTNG). This non-invasive technique offered the animal physiologist a tool to monitor the growth of an animal in response to new genetic, nutritional and pharmacologic methods for livestock improvement. While measurement of carbon (C), nitrogen (N) and oxygen (O) determined protein, fat and water because of the fixed stoichiometric proportions of these elements in these body components, the unique C/N and C/O ratios of high explosives revealed their identity in UXO. The algorithm that was developed and implemented to extract C, N and O counts from an APT generated gamma-ray spectrum will be presented together with the UXO investigations that involved preliminary proofof-concept studies and modeling with Monte Carlo produced synthetic spectra of 57-155 mm projectiles.

  5. Correcting the effects of the matrix using capture gamma-ray spectrometry: Application to measurement by Active Neutron Interrogation; Correction des effets de matrice par spectrometrie des rayonnements gamma de capture: Application a la mesure par Interrogation Neutronique Active (I.N.A.)

    Energy Technology Data Exchange (ETDEWEB)

    Baudry, G.

    2003-11-15

    In the field of the measurement of low masses of fissile material ({sup 235}U, {sup 239}Pu, {sup 241}Pu) in radioactive waste drums, the Active Neutron Interrogation is a non-destructive method achieving good results. It does however remain reliant upon uncertainties related to the matrix effects on interrogation and fission neutrons. The aim of this thesis is to develop a correction method able to take into account these matrix effects by quantifying the amount of absorbent materials (chlorine and hydrogen) in a 118- liter homogeneous matrix. The main idea is to use the gamma-ray spectrometry of gamma emitted by neutron captures to identify and quantify the composition of the matrix. An indicator from its chlorine content is then deduced in order to choose the calibration coefficient which best represents the real composition of the matrix. This document firstly presents the needs of control and characterization of radioactive objects, and the means used in the field of nuclear measurement. Emphases is put in particular on the Active Neutron Interrogation method. The matrices of interest are those made of light technological waste (density {<=} 0,4 g/cm{sup 3}) containing hydrogenated and chlorinated materials. The advantages of gamma-rays emitted by neutron captures for the determination of a chlorine content indicator of the matrices and the principles of the correction method are then explained. Measurements have been firstly realized with an existing Neutron Interrogation device (PROMETHEE 6). Such measurements have proven its inadequacy: no signal from the matrix hydrogen was detected, due to an intense signal from the polyethylene contained in some cell elements. Moreover, the matrix chlorine content appeared difficult to be measured. A new and specific device, named REGAIN and dedicated to active gamma-rays spectrometry, was defined with the Monte-Carlo N-Particle (MCNP) code. The experiments conducted with this new device made it possible to detect the

  6. Photon interrogation for bulk measurement of transuranic materials

    International Nuclear Information System (INIS)

    Nieschmidt, E.B.

    1981-01-01

    Investigation and assay of high atomic number materials may be accomplished in near real-time through use of photon interrogation. Photon interrogation, as used here, involves the use of high-energy photons to induce fission and then detect neutrons associated with the fission. This technique has the advantage that the interrogating particle and the detected particle are different. The discussion here will include: (1) neutron production; (2) photon production; (3) neutron counting; (4) sensitivity; and (5) problems associated with large containers. In summary, the attributes and limitations of photon interrogation can be stated as: near real-time accountability; interrogating particle different than detected particle; ability to count prompt or delayed neutrons depending on matrix; radiography or therapy accelerators available; cannot distinguish between fission and fertile material; and interrogated material must be well characterized to obtain safeguards quality results

  7. Quark phases in neutron stars and a third family of compact stars as signature for phase transitions

    International Nuclear Information System (INIS)

    Schertler, K.; Greiner, C.; Schaffner-Bielich, J.; Thoma, M.H.

    2000-01-01

    The appearance of quark phases in the dense interior of neutron stars provides one possibility to soften the equation of state (EOS) of neutron star matter at high densities. This softening leads to more compact equilibrium configurations of neutron stars compared to pure hadronic stars of the same mass. We investigate the question to which amount the compactness of a neutron star can be attributed to the presence of a quark phase. For this purpose we employ several hadronic EOS in the framework of the relativistic mean-field (RMF) model and an extended MIT bag model to describe the quark phase. We find that -- almost independent of the model parameters -- the radius of a pure hadronic neutron star gets typically reduced by 20-30% if a pure quark phase in the center of the star does exist. For some EOS we furthermore find the possibility of a third family of compact stars which may exist besides the two known families of white dwarfs and neutron stars. We show how an experimental proof of the existence of a third family by mass and radius measurements may provide a unique signature for a phase transition inside neutron stars

  8. Ion-induced gammas for photofission interrogation of HEU.

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Barney Lee (Sandia National Laboratories, Albuquerque, NM); Antolak, Arlyn J.; Morse, Daniel H.; Provencio, Paula Polyak (Sandia National Laboratories, Albuquerque, NM)

    2006-03-01

    High-energy photons and neutrons can be used to actively interrogate for heavily shielded special nuclear material (SNM), such as HEU (highly enriched uranium), by detecting prompt and/or delayed induced fission signatures. In this work, we explore the underlying physics for a new type of photon source that generates high fluxes of mono-energetic gamma-rays from low-energy (<500 keV) proton-induced nuclear reactions. The characteristic energies (4- to 18-MeV) of the gamma-rays coincide with the peak of the photonuclear cross section. The source could be designed to produce gamma-rays of certain selected energies, thereby improving the probability of detecting shielded HEU or providing a capability to determine enrichment inside sealed containers. The fundamental physics of such an interrogation source were studied in this LDRD through scaled ion accelerator experiments and radiation transport modeling. The data were used to assess gamma and neutron yields, background, and photofission-induced signal levels from several (p,{gamma}) target materials under consideration.

  9. Study and development of a method allowing the identification of actinides inside nuclear waste packages, by active neutron or photon interrogation and delayed gamma-ray spectrometry; Etude et developpement d'une technique de dosage des actinides dans les colis de dechets radioactifs par interrogation photonique ou neutronique active et spectrometrie des gamma retardes

    Energy Technology Data Exchange (ETDEWEB)

    Carrel, F

    2007-10-15

    An accurate estimation of the alpha-activity of a nuclear waste package is necessary to select the best mode of storage. The main purpose of this work is to develop a non-destructive active method, based on the fission process and allowing the identification of actinides ({sup 235}U, {sup 238}U, {sup 239}Pu). These three elements are the main alpha emitters contained inside a package. Our technique is based on the detection of delayed gammas emitted by fission products. These latter are created by irradiation with the help of a neutron or photon beam. Performances of this method have been investigated after an Active Photon or Neutron Interrogation (INA or IPA). Three main objectives were fixed in the framework of this thesis. First, we measured many yields of photofission products to compensate the lack of data in the literature. Then, we studied experimental performances of this method to identify a given actinide ({sup 239}Pu in fission, {sup 235}U in photofission) present in an irradiated mixture. Finally, we assessed the application of this technique on different mock-up packages for both types of interrogation (118 l mock-up package containing EVA in fission, 220 l mock-up package with a wall of concrete in photofission). (author)

  10. Active interrogation of highly enriched uranium

    Science.gov (United States)

    Fairrow, Nannette Lea

    Safeguarding special nuclear material (SNM) in the Department of Energy Complex is vital to the national security of the United States. Active and passive nondestructive assays are used to confirm the presence of SNM in various configurations ranging from waste to nuclear weapons. Confirmation measurements for nuclear weapons are more challenging because the design complicates the detection of a distinct signal for highly enriched uranium. The emphasis of this dissertation was to investigate a new nondestructive assay technique that provides an independent and distinct signal to confirm the presence of highly enriched uranium (HEU). Once completed and tested this assay method could be applied to confirmation measurements of nuclear weapons. The new system uses a 14-MeV neutron source for interrogation and records the arrival time of neutrons between the pulses with a high efficiency detection system. The data is then analyzed by the Feynman reduced variance method. The analysis determined the amount of correlation in the data and provided a unique signature of correlated fission neutrons. Measurements of HEU spheres were conducted at Los Alamos with the new system. Then, Monte Carlo calculations were performed to verify hypothesis made about the behavior of the neutrons in the experiment. Comparisons of calculated counting rates by the Monte Carlo N-Particle Transport Code (MCNP) were made with the experimental data to confirm that the measured response reflected the desired behavior of neutron interactions in the highly enriched uranium. In addition, MCNP calculations of the delayed neutron build-up were compared with the measured data. Based on the results obtained from this dissertation, this measurement method has the potential to be expanded to include mass determinations of highly enriched uranium. Although many safeguards techniques exist for measuring special nuclear material, the number of assays that can be used to confirm HEU in shielded systems is

  11. Signature splitting in nuclear rotational bands: Neutron i13/2 systematics

    International Nuclear Information System (INIS)

    Mueller, W.F.; Jensen, H.J.; Reviol, W.; Riedinger, L.L.; Yu, C.; Zhang, J.; Nazarewicz, W.; Wyss, R.

    1994-01-01

    Experimental values of signature splitting in νi 13/2 rotational bands in odd-N even-Z nuclei in the Z=62--78 region are collected and presented. A procedure is introduced to calculate signature splitting within the cranked deformed Woods-Saxon model. In the theoretical treatment, deformation parameters are obtained by minimizing the total Routhians of individual νi 13/2 bands, and the procedure accounts for the possibility that the two signatures have different deformations and pairing gaps. Experimental signature splitting data for νi 13/2 bands in Dy, Er, Yb, Hf, W, and Os nuclei are compared with calculated values. The sensitivity of calculated signature splitting to changes in deformation, pairing, and other model parameters is presented

  12. Combined Photoneutron And X Ray Interrogation Of Containers For Nuclear Materials

    Science.gov (United States)

    Gozani, Tsahi; Shaw, Timothy; King, Michael J.; Stevenson, John; Elsalim, Mashal; Brown, Craig; Condron, Cathie

    2011-06-01

    Effective cargo inspection systems for nuclear material detection require good penetration by the interrogating radiation, generation of a sufficient number of fissions, and strong and penetrating detection signatures. Inspection systems need also to be sensitive over a wide range of cargo types and densities encountered in daily commerce. Thus they need to be effective with highly hydrogenous cargo, where neutron attenuation is a major limitation, as well as with dense metallic cargo, where x-ray penetration is low. A system that interrogates cargo with both neutrons and x-rays can, in principle, achieve high performance over the widest range of cargos. Moreover, utilizing strong prompt-neutron (˜3 per fission) and delayed-gamma ray (˜7 per fission) signatures further strengthens the detection sensitivity across all cargo types. The complementary nature of x-rays and neutrons, used as both probing radiation and detection signatures, alleviates the need to employ exceedingly strong sources, which would otherwise be required to achieve adequate performance across all cargo types, if only one type of radiation probe were employed. A system based on the above principles, employing a commercially-available 9 MV linac was developed and designed. Neutrons are produced simultaneously with x-rays by the photonuclear interaction of the x-ray beam with a suitable converter. A total neutron yield on the order of 1011 n/s is achieved with an average electron beam current of 100 μA. If fissionable material is present, fissions are produced both by the high-energy x-ray beam and by the photoneutrons. Photofission and neutron fission dominate in hydrogenous and metallic cargos, respectively. Neutron-capture gamma rays provide information on the cargo composition. The prompt neutrons resulting from fission are detected by two independent detector systems: by very efficient Differential Die Away Analysis (DDAA) detectors, and by direct detection of neutrons with energies higher

  13. Signatures of field induced spin polarization of neutron star matter in seismic vibrations of paramagnetic neutron star

    International Nuclear Information System (INIS)

    Bastrukov, S I; Yang, J; Podgainy, D V; Weber, F

    2003-01-01

    A macroscopic model of the dissipative magneto-elastic dynamics of viscous spin polarized nuclear matter is discussed in the context of seismic activity of a paramagnetic neutron star. The source of the magnetic field of such a star is attributed to Pauli paramagnetism of baryon matter promoted by a seed magnetic field frozen into the star in the process of gravitational collapse of a massive progenitor. Particular attention is given to the effect of shear viscosity of incompressible stellar material on the timing of non-radial torsional magneto-elastic pulsations of the star triggered by starquakes. By accentuating the fact that this kind of vibration is unique to the seismology of a paramagnetic neutron star we show that the high-frequency modes decay faster than the low-frequency modes. The obtained analytic expressions for the period and relaxation time of this mode, in which the magnetic susceptibility and viscosity enter as input parameters, are then quantified by numerical estimates for these parameters taken from early and current works on transport coefficients of dense matter. It is found that the effect of viscosity is crucial for the lifetime of magneto-torsion vibrations but it does not appreciably affect the periods of this seismic mode which fall in the realm of periods of pulsed emission of soft gamma-ray repeaters and anomalous x-ray pulsars - young super-magnetized neutron stars, radiating, according to the magnetar model, at the expense of the magnetic energy release. Finally, we present arguments that the long periodic pulsed emission of these stars in a quiescent regime of radiation can be interpreted as a manifestation of weakly damped seismic magneto-torsion vibrations exhibiting the field induced spin polarization of baryon matter

  14. Reaction-in-flight neutrons as a signature for shell mixing in National Ignition Facility capsules

    International Nuclear Information System (INIS)

    Hayes, A. C.; Bradley, P. A.; Grim, G. P.; Jungman, Gerard; Wilhelmy, J. B.

    2010-01-01

    Analytic calculations and results from computational simulations are presented that suggest that reaction-in-flight (RIF) neutrons can be used to diagnose mixing of the ablator shell material into the fuel in deuterium-tritium (DT) capsules designed for the National Ignition Facility (NIF) [J. A. Paisner, J. D. Boyes, S. A. Kumpan, W. H. Lowdermilk, and M. S. Sorem, Laser Focus World 30, 75 (1994)]. Such mixing processes in NIF capsules are of fundamental physical interest and can have important effects on capsule performance, quenching the total thermonuclear yield. The sensitivity of RIF neutrons to hydrodynamical mixing arises through the dependence of RIF production on charged-particle stopping lengths in the mixture of DT fuel and ablator material. Since the stopping power in the plasma is a sensitive function of the electron temperature and density, it is also sensitive to mix. RIF production scales approximately inversely with the degree of mixing taking place, and the ratio of RIF to down-scattered neutrons provides a measure of the mix fraction and/or the mixing length. For sufficiently high-yield capsules, where spatially resolved RIF images may be possible, neutron imaging could be used to map RIF images into detailed mix images.

  15. Psychological Perspectives on Interrogation.

    Science.gov (United States)

    Vrij, Aldert; Meissner, Christian A; Fisher, Ronald P; Kassin, Saul M; Morgan, Charles A; Kleinman, Steven M

    2017-11-01

    Proponents of "enhanced interrogation techniques" in the United States have claimed that such methods are necessary for obtaining information from uncooperative terrorism subjects. In the present article, we offer an informed, academic perspective on such claims. Psychological theory and research shows that harsh interrogation methods are ineffective. First, they are likely to increase resistance by the subject rather than facilitate cooperation. Second, the threatening and adversarial nature of harsh interrogation is often inimical to the goal of facilitating the retrieval of information from memory and therefore reduces the likelihood that a subject will provide reports that are extensive, detailed, and accurate. Third, harsh interrogation methods make lie detection difficult. Analyzing speech content and eliciting verifiable details are the most reliable cues to assessing credibility; however, to elicit such cues subjects must be encouraged to provide extensive narratives, something that does not occur in harsh interrogations. Evidence is accumulating for the effectiveness of rapport-based information-gathering approaches as an alternative to harsh interrogations. Such approaches promote cooperation, enhance recall of relevant and reliable information, and facilitate assessments of credibility. Given the available evidence that torture is ineffective, why might some laypersons, policymakers, and interrogation personnel support the use of torture? We conclude our review by offering a psychological perspective on this important question.

  16. A Qualitative Analysis of the Neutron Population in Fresh and Spent Fuel Assemblies during Simulated Interrogation using the Differential Die-Away Technique

    International Nuclear Information System (INIS)

    Lundkvista, Niklas; Goodsell, Alison V.; Grapea, Sophie; Hendricksb, John S.; Henzlb, Vladimir; Swinhoe, Martyn T.; Tobin, Stephen J.

    2015-01-01

    Monte Carlo simulations were performed for the differential die-away (DDA) technique to analyse the time-dependent behaviour of the neutron population in fresh and spent nuclear fuel assemblies as part of the Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) Project. Simulations were performed to investigate both a possibly portable as well as a permanent DDA instrument. Taking advantage of a custom made modification to the MCNPX code, the variation in the neutron population, simultaneously in time and space, was examined. The motivation for this research was to improve the design of the DDA instrument, as it is being considered for possible deployment at the Central Storage of Spent Nuclear Fuel and Encapsulation Plant in Sweden (Clab), as well as to assist in the interpretation of the both simulated and measured signals.

  17. Spent fuel measurements. passive neutron albedo reactivity (PNAR) and photon signatures

    Energy Technology Data Exchange (ETDEWEB)

    Eigenbrodt, Julia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Menlove, Howard Olsen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-29

    The International Atomic Energy Agency’s (IAEA) safeguards technical objective is the timely detection of a diversion of a significant quantity of nuclear material from peaceful activities to the manufacture of nuclear weapons or of other nuclear explosive devices or for purposes unknown, and deterrence of such diversion by the risk of early detection. An important IAEA task towards meeting this objective is the ability to accurately and reliably measure spent nuclear fuel (SNF) to verify reactor operating parameters and verify that the fuel has not been removed from reactors or SNF storage facilities. This dissertation analyzes a method to improve the state-of-the-art of nuclear material safeguards measurements using two combined measurement techniques: passive neutron albedo reactivity (PNAR) and passive spectral photon measurements.

  18. Impact of ejecta morphology and composition on the electromagnetic signatures of neutron star mergers

    Science.gov (United States)

    Wollaeger, Ryan T.; Korobkin, Oleg; Fontes, Christopher J.; Rosswog, Stephan K.; Even, Wesley P.; Fryer, Christopher L.; Sollerman, Jesper; Hungerford, Aimee L.; van Rossum, Daniel R.; Wollaber, Allan B.

    2018-04-01

    The electromagnetic transients accompanying compact binary mergers (γ-ray bursts, afterglows and 'macronovae') are crucial to pinpoint the sky location of gravitational wave sources. Macronovae are caused by the radioactivity from freshly synthesised heavy elements, e.g. from dynamic ejecta and various types of winds. We study macronova signatures by using multi-dimensional radiative transfer calculations. We employ the radiative transfer code SuperNu and state-of-the art LTE opacities for a few representative elements from the wind and dynamical ejecta (Cr, Pd, Se, Te, Br, Zr, Sm, Ce, Nd, U) to calculate synthetic light curves and spectra for a range of ejecta morphologies. The radioactive power of the resulting macronova is calculated with the detailed input of decay products. We assess the detection prospects for our most complex models, based on the portion of viewing angles that are sufficiently bright, at different cosmological redshifts (z). The brighter emission from the wind is unobscured by the lanthanides (or actinides) in some of the models, permitting non-zero detection probabilities for redshifts up to z = 0.07. We also find the nuclear mass model and the resulting radioactive heating rate are crucial for the detectability. While for the most pessimistic heating rate (from the FRDM model) no reasonable increase in the ejecta mass or velocity, or wind mass or velocity, can possibly make the light curves agree with the observed nIR excess after GRB130603B, a more optimistic heating rate (from the Duflo-Zuker model) leads to good agreement. We conclude that future reliable macronova observations would constrain nuclear heating rates, and consequently help constrain nuclear mass models.

  19. Interrogation: General vs. Local.

    Science.gov (United States)

    Johnson, Jeannette

    This paper proposes a set of hypotheses on the nature of interrogration as a possible language universal. Examples and phrase structure rules and diagrams are given. Examining Tamazight and English, genetically unrelated languages with almost no contact, the author distinguishes two types of interrogation: (1) general, querying acceptability to…

  20. Interrogating Planar Cyclooctatetraenes

    DEFF Research Database (Denmark)

    Hensel, Thomas

    ]circulenes were established. The antiaromaticity of the formal COT core of the hetero[8]circulenes was interrogated by comparison of the respective 13C-NMR carbon shifts with those of 3,6-dimethoxycarbazole (the starting material), tetrahydroxy intermediate and literature values. No uniform paratropic...

  1. Modeling and Interrogative Strategies.

    Science.gov (United States)

    Denney, Douglas R.

    Three studies to determine the effects of adult models on interrogative strategies of children (ages 6-11) are reviewed. Two issues are analyzed: (1) the comparative effectiveness of various types of modeling procedures for changing rule-governed behaviors, and (2) the interaction between observational learning and the developmental level of the…

  2. Nuclear materials identification by photon interrogation

    International Nuclear Information System (INIS)

    Pozzi, S.A.; Monville, M.; Padovani, E.

    2005-01-01

    We describe a preliminary modification to the Monte Carlo codes MCNP-X and MCNP-PoliMi that is aimed at simulating the neutron and photon field generated by interrogating fissile (and non-fissile) material with a high energy photon source. Photo-atomic and photo-nuclear collisions are modeled, with particular emphasis on the generation of secondary particles that are emitted as a result of these interactions. The simulations can be used to design and analyze measurements that are performed in a wide variety of scenarios. An application of the methodology to the interrogation of packages on a luggage belt conveyor is presented. Preliminary results show that it is possible to detect 5 Kg of highly enriched uranium in a package by measuring the correlation function between 2 detectors. This correlation function is based on the detection of prompt radiation from photonuclear events

  3. Detection of land mines using fast and thermal neutron analysis

    International Nuclear Information System (INIS)

    Bach, P.

    1998-01-01

    The detection of land mines is made possible by using nuclear sensor based on neutron interrogation. Neutron interrogation allows to detect the sensitive elements (C, H, O, N) of the explosives in land mines or in unexploded shells: the evaluation of characteristic ratio N/O and C/O in a volume element gives a signature of high explosives. Fast neutron interrogation has been qualified in our laboratories as a powerful close distance method for identifying the presence of a mine or explosive. This method could be implemented together with a multisensor detection system - for instance IR or microwave - to reduce the false alarm rate by addressing the suspected area. Principle of operation is based on the measurement of gamma rays induced by neutron interaction with irradiated nuclei from the soil and from a possible mine. Specific energy of these gamma rays allows to recognise the elements at the origin of neutron interaction. Several detection methods can be used, depending on nuclei to be identified. Analysis of physical data, computations by simulation codes, and experimentations performed in our laboratory have shown the interest of Fast Neutron Analysis (FNA) combined with Thermal Neutron Analysis (TNA) techniques, especially for detection of nitrogen 14 N, carbon 12 C and oxygen 16 O. The FNA technique can be implemented using a 14 MeV sealed neutron tube, and a set of detectors. The mines detection has been demonstrated from our investigations, using a low power neutron generator working in the 10 8 n/s range, which is reasonable when considering safety rules. A fieldable demonstrator would be made with a detection head including tube and detectors, and with remote electronics, power supplies and computer installed in a vehicle. (author)

  4. Suicidality and interrogative suggestibility.

    Science.gov (United States)

    Pritchard-Boone, Lea; Range, Lillian M

    2005-01-01

    All people are subject to memory suggestibility, but suicidal individuals may be especially so. The link between suicidality and suggestibility is unclear given mixed findings and methodological weaknesses of past research. To test the link between suicidality and interrogative suggestibility, 149 undergraduates answered questions about suicidal thoughts and reasons for living, and participated in a direct suggestibility procedure. As expected, suggestibility correlated with suicidality but accounted for little overall variance (4%). Mental health professionals might be able to take advantage of client suggestibility by directly telling suicidal persons to refrain from suicidal thoughts or actions.

  5. Basics of Neutrons for First Responders

    Energy Technology Data Exchange (ETDEWEB)

    Rees, Brian G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-02-05

    These are slides from a presentation on the basics of neutrons. A few topics covered are: common origins of terrestrial neutron radiation, neutron sources, neutron energy, interactions, detecting neutrons, gammas from neutron interactions, neutron signatures in gamma-ray spectra, neutrons and NaI, neutron fluence to dose (msV), instruments' response to neutrons.

  6. Nuclear Material Detection by One-Short-Pulse-Laser-Driven Neutron Source

    International Nuclear Information System (INIS)

    Favalli, Andrea; Aymond, F.; Bridgewater, Jon S.; Croft, Stephen; Deppert, O.; Devlin, Matthew James; Falk, Katerina; Fernandez, Juan Carlos; Gautier, Donald Cort; Gonzales, Manuel A.; Goodsell, Alison Victoria; Guler, Nevzat; Hamilton, Christopher Eric; Hegelich, Bjorn Manuel; Henzlova, Daniela; Ianakiev, Kiril Dimitrov; Iliev, Metodi; Johnson, Randall Philip; Jung, Daniel; Kleinschmidt, Annika; Koehler, Katrina Elizabeth; Pomerantz, Ishay; Roth, Markus; Santi, Peter Angelo; Shimada, Tsutomu; Swinhoe, Martyn Thomas; Taddeucci, Terry Nicholas; Wurden, Glen Anthony; Palaniyappan, Sasikumar; McCary, E.

    2015-01-01

    Covered in the PowerPoint presentation are the following areas: Motivation and requirements for active interrogation of nuclear material; laser-driven neutron source; neutron diagnostics; active interrogation of nuclear material; and, conclusions, remarks, and future works.

  7. Detection of special nuclear material from delayed neutron emission induced by a dual-particle monoenergetic source

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, M. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Nattress, J.; Jovanovic, I., E-mail: ijov@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2016-06-27

    Detection of unique signatures of special nuclear materials is critical for their interdiction in a variety of nuclear security and nonproliferation scenarios. We report on the observation of delayed neutrons from fission of uranium induced in dual-particle active interrogation based on the {sup 11}B(d,n γ){sup 12}C nuclear reaction. Majority of the fissions are attributed to fast fission induced by the incident quasi-monoenergetic neutrons. A Li-doped glass–polymer composite scintillation neutron detector, which displays excellent neutron/γ discrimination at low energies, was used in the measurements, along with a recoil-based liquid scintillation detector. Time-dependent buildup and decay of delayed neutron emission from {sup 238}U were measured between the interrogating beam pulses and after the interrogating beam was turned off, respectively. Characteristic buildup and decay time profiles were compared to the common parametrization into six delayed neutron groups, finding a good agreement between the measurement and nuclear data. This method is promising for detecting fissile and fissionable materials in cargo scanning applications and can be readily integrated with transmission radiography using low-energy nuclear reaction sources.

  8. 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.

  9. Monte Carlo Simulation for LINAC Standoff Interrogation of Nuclear Material

    International Nuclear Information System (INIS)

    Clarke, Shaun D.; Flaska, Marek; Miller, Thomas Martin; Protopopescu, Vladimir A.; Pozzi, Sara A.

    2007-01-01

    The development of new techniques for the interrogation of shielded nuclear materials relies on the use of Monte Carlo codes to accurately simulate the entire system, including the interrogation source, the fissile target and the detection environment. The objective of this modeling effort is to develop analysis tools and methods-based on a relevant scenario-which may be applied to the design of future systems for active interrogation at a standoff. For the specific scenario considered here, the analysis will focus on providing the information needed to determine the type and optimum position of the detectors. This report describes the results of simulations for a detection system employing gamma rays to interrogate fissile and nonfissile targets. The simulations were performed using specialized versions of the codes MCNPX and MCNP-PoliMi. Both prompt neutron and gamma ray and delayed neutron fluxes have been mapped in three dimensions. The time dependence of the prompt neutrons in the system has also been characterized For this particular scenario, the flux maps generated with the Monte Carlo model indicate that the detectors should be placed approximately 50 cm behind the exit of the accelerator, 40 cm away from the vehicle, and 150 cm above the ground. This position minimizes the number of neutrons coming from the accelerator structure and also receives the maximum flux of prompt neutrons coming from the source. The lead shielding around the accelerator minimizes the gamma-ray background from the accelerator in this area. The number of delayed neutrons emitted from the target is approximately seven orders of magnitude less than the prompt neutrons emitted from the system. Therefore, in order to possibly detect the delayed neutrons, the detectors should be active only after all prompt neutrons have scattered out of the system. Preliminary results have shown this time to be greater than 5 ?s after the accelerator pulse. This type of system is illustrative of a

  10. Signatures of asymmetry in neutron spectra and images predicted by three-dimensional radiation hydrodynamics simulations of indirect drive implosions

    Energy Technology Data Exchange (ETDEWEB)

    Chittenden, J. P., E-mail: j.chittenden@imperial.ac.uk; Appelbe, B. D.; Manke, F.; McGlinchey, K.; Niasse, N. P. L. [Centre for Inertial Fusion Studies, The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom)

    2016-05-15

    We present the results of 3D simulations of indirect drive inertial confinement fusion capsules driven by the “high-foot” radiation pulse on the National Ignition Facility. The results are post-processed using a semi-deterministic ray tracing model to generate synthetic deuterium-tritium (DT) and deuterium-deuterium (DD) neutron spectra as well as primary and down scattered neutron images. Results with low-mode asymmetries are used to estimate the magnitude of anisotropy in the neutron spectra shift, width, and shape. Comparisons of primary and down scattered images highlight the lack of alignment between the neutron sources, scatter sites, and detector plane, which limits the ability to infer the ρr of the fuel from a down scattered ratio. Further calculations use high bandwidth multi-mode perturbations to induce multiple short scale length flows in the hotspot. The results indicate that the effect of fluid velocity is to produce a DT neutron spectrum with an apparently higher temperature than that inferred from the DD spectrum and which is also higher than the temperature implied by the DT to DD yield ratio.

  11. Enhancing the performance of a tensioned metastable fluid detector based active interrogation system for the detection of SNM in interrogation source in moderated/reflected geometries

    Science.gov (United States)

    Grimes, T. F.; Hagen, A. R.; Archambault, B. C.; Taleyarkhan, R. P.

    2018-03-01

    This paper describes the development of a SNM detection system for interrogating 1m3 cargos via the combination of a D-D neutron interrogation source (with and without reflectors) and tensioned metastable fluid detectors (TMFDs). TMFDs have been previously shown (Taleyarkhan et al., 2008; Grimes et al., 2015; Grimes and Taleyarkhan, 2016; Archambault et al., 2017; Hagen et al., 2016) to be capable of using Threshold Energy Neutron Analysis (TENA) techniques to reject the ∼2.45 MeV D-D interrogating neutrons while still remaining sensitive to >2.45 MeV neutrons resulting from fission in the target (HEU) material. In order to enhance the performance, a paraffin reflector was included around the accelerator head. This reflector was used to direct neutrons into the package to increase the fission signal, lower the energy of the interrogating neutrons to increase the fission cross-section with HEU, and, also to direct interrogating neutrons away from the detectors in order to enhance the required discrimination between interrogating and fission neutrons. Experiments performed with a 239 Pu-Be neutron source and MnO2 indicated that impressive performance gains could be made by placing a parabolic paraffin moderator between the interrogation source and an air-filled cargo container with HEU placed at the center. However, experiments with other cargo fillers (as specified in the well-known ANSI N42.41-2007 report), and with HEU placed in locations other than the center of the package indicated that other reflector geometries might be superior due to over-"focusing" and the increased solid angle effects due to the accommodation of the moderator geometry. The best performance for the worst case of source location and box fill was obtained by placing the reflector only behind the D-D neutron source rather than in front of it. Finally, it was shown that there could be significant gains in the ability to detect concealed SNM by operating the system in multiple geometric

  12. Police practices and perceptions regarding juvenile interrogation and interrogative suggestibility.

    Science.gov (United States)

    Meyer, Jessica R; Reppucci, N Dickon

    2007-01-01

    Recent media coverage has highlighted cases in which young suspects were wrongly convicted because they provided interrogation-induced false confessions. Although youth may be more highly suggestible and easily influenced by authority than adults, police are trained to use the same psychologically coercive and deceptive tactics with youth as with adults. This investigation is the first standard documentation of the reported interrogation practices of law enforcement and police beliefs about the reliability of these techniques and their knowledge of child development. Participants were 332 law enforcement officers who completed surveys about interrogation procedures and developmental issues pertaining to youth. Results indicated that, while police acknowledge some developmental differences between youth and adults, there were indications that (1) how police perceive youth in general and how they perceive and treat them in the interrogation context may be contradictory and (2) their general view is that youth can be dealt with in the same manner as adults. Copyright (c) 2007 John Wiley & Sons, Ltd.

  13. Interrogating personhood and dementia

    Science.gov (United States)

    Higgs, Paul; Gilleard, Chris

    2016-01-01

    ABSTRACT Objectives: To interrogate the concept of personhood and its application to care practices for people with dementia. Method: We outline the work of Tom Kitwood on personhood and relate this to conceptualisations of personhood in metaphysics and in moral philosophy. Results: The philosophical concept of personhood has a long history. The metaphysical tradition examines the necessary and sufficient qualities that make up personhood such as agency, consciousness, identity, rationality and second-order reflexivity. Alternative viewpoints treat personhood as a matter of degree rather than as a superordinate category. Within moral philosophy personhood is treated as a moral status applicable to some or to all human beings. Conclusion: In the light of the multiple meanings attached to the term in both metaphysics and moral philosophy, personhood is a relatively unhelpful concept to act as the foundation for developing models and standards of care for people with dementia. Care, we suggest, should concentrate less on ambiguous and somewhat abstract terms such as personhood and focus instead on supporting people's existing capabilities, while minimising the harmful consequences of their incapacities. PMID:26708149

  14. The dynamic nature of interrogation.

    Science.gov (United States)

    Kelly, Christopher E; Miller, Jeaneé C; Redlich, Allison D

    2016-06-01

    Building on a substantial body of literature examining interrogation methods employed by police investigators and their relationship to suspect behaviors, we analyzed a sample of audio and video interrogation recordings of individuals suspected of serious violent crimes. Existing survey research has focused on the tactics reportedly used, at what rate, and under what conditions; observational studies detail which methods are actually employed. With a few notable exceptions, these foundational studies were static examinations of interrogation methods that documented the absence or presence of various approaches. In the present study, we cast interrogation as a dynamic phenomenon and code the recordings in 5-min intervals to examine how interrogation methods and suspect cooperation change over time. Employing the interrogation taxonomy framework, particularly 4 discrete domains-rapport and relationship building, emotion provocation, presentation of evidence, and confrontation/competition-we found that the emphasis of the domains varied across interrogations and were significantly different when suspects confessed versus when they denied involvement. In regression models, suspect cooperation was positively influenced by the rapport and relationship building domain, though it was negatively impacted by presentation of evidence and confrontation/competition. Moreover, we found that the negative effects of confrontation/competition on suspect cooperation lasted for up to 15 min. The implications of the findings for practice and future research include the benefits of a rapport-based approach, the deleterious effects of accusatorial methods, and the importance of studying when, not just if, certain interrogation techniques are employed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Active Interrogation using Photofission Technique for Nuclear Materials Control and Accountability

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Haori [Oregon State Univ., Corvallis, OR (United States)

    2016-03-31

    Innovative systems with increased sensitivity and resolution are in great demand to detect diversion and to prevent misuse in support of nuclear materials management for the U.S. fuel cycle. Nuclear fission is the most important multiplicative process involved in non-destructive active interrogation. This process produces the most easily recognizable signature for nuclear materials. In addition to thermal or high-energy neutrons, high-energy gamma rays can also excite a nucleus and cause fission through a process known as photofission. Electron linear accelerators (linacs) are widely used as the interrogating photon sources for inspection methods involving photofission technique. After photofission reactions, prompt signals are much stronger than the delayed signals, but it is difficult to quantify them in practical measurements. Delayed signals are easily distinguishable from the interrogating radiation. Linac-based, advanced inspection techniques utilizing the delayed signals after photofission have been extensively studied for homeland security applications. Previous research also showed that a unique delayed gamma ray energy spectrum exists for each fissionable isotope. In this work, high-energy delayed γ-rays were demonstrated to be signatures for detection, identification, and quantification of special nuclear materials. Such γ-rays were measured in between linac pulses using independent data acquisition systems. A list-mode system was developed to measure low-energy delayed γ-rays after irradiation. Photofission product yields of 238U and 239Pu were determined based on the measured delayed γ-ray spectra. The differential yields of delayed γ-rays were also proven to be able to discriminate nuclear from non-nuclear materials. The measurement outcomes were compared with Monte Carlo simulation results. It was demonstrated that the current available codes have capabilities and limitations in the simulation of photofission process. A two

  16. Active Interrogation using Photofission Technique for Nuclear Materials Control and Accountability

    International Nuclear Information System (INIS)

    Yang, Haori

    2016-01-01

    Innovative systems with increased sensitivity and resolution are in great demand to detect diversion and to prevent misuse in support of nuclear materials management for the U.S. fuel cycle. Nuclear fission is the most important multiplicative process involved in non-destructive active interrogation. This process produces the most easily recognizable signature for nuclear materials. In addition to thermal or high-energy neutrons, high-energy gamma rays can also excite a nucleus and cause fission through a process known as photofission. Electron linear accelerators (linacs) are widely used as the interrogating photon sources for inspection methods involving photofission technique. After photofission reactions, prompt signals are much stronger than the delayed signals, but it is difficult to quantify them in practical measurements. Delayed signals are easily distinguishable from the interrogating radiation. Linac-based, advanced inspection techniques utilizing the delayed signals after photofission have been extensively studied for homeland security applications. Previous research also showed that a unique delayed gamma ray energy spectrum exists for each fissionable isotope. In this work, high-energy delayed γ-rays were demonstrated to be signatures for detection, identification, and quantification of special nuclear materials. Such γ-rays were measured in between linac pulses using independent data acquisition systems. A list-mode system was developed to measure low-energy delayed γ-rays after irradiation. Photofission product yields of 238 U and 239 Pu were determined based on the measured delayed γ-ray spectra. The differential yields of delayed γ-rays were also proven to be able to discriminate nuclear from non-nuclear materials. The measurement outcomes were compared with Monte Carlo simulation results. It was demonstrated that the current available codes have capabilities and limitations in the simulation of photofission process. A two-fold approach was

  17. Integrated Box Interrogation System (IBIS) Preliminary Design Study

    CERN Document Server

    Croft, S; Chard-Mj, P; Estop, J R; Martancik, D; Sheila-Melton; Young, B

    2003-01-01

    Canberra Industries has won the tendered solicitation, INEEL/EST-99-00121 for boxed waste Nondestructive Assay Development and Demonstration. Canberra will provide the Integrated Box Interrogation System (IBIS) which is a suite of assay instrumentation and a data reduction system that addresses the measurement needs for Boxed Wastes identified in the solicitation and facilitates the associated experimental program and demonstration of system capability. The IBIS system will consist of the next generation CWAM system, i.e. CWAM II, which is a Scanning Passive/Active Neutron interrogation system which we will call a Box Segmented Neutron Scanner (BSNS), combined with a physically separate Box Segmented Gamma-ray Scanning (BSGS) system. These systems are based on existing hardware designs but will be tailored to the large sample size and enhanced to allow the program to evaluate the following measurement criteria:Characterization and correction for matrix heterogeneity Characterization of non-uniform radio-nucli...

  18. Photon interrogation annual report for FY-1980

    International Nuclear Information System (INIS)

    Nieschmidt, E.B.; Tsang, F.Y.; Lawrence, R.S.; Vegors, S.H. Jr.

    1980-12-01

    The Photon Interrogation Technique is being developed for the assay of transuranic materials. A description of source and detector geometry, die-away times and photon flux measurements is given. Considerable effort during FY-1980 was devoted to collimator construction and shielding materials and configurations. Boric acid was found to be a very efficient shielding material for this application. Descriptions and results of these efforts are presented. Results of photon flux determinations, system response to source position and their effects on accuracy are discussed. Changes in the detector system produced a considerable efficiency increase and instrumentation changes brought improved performance. The instrument system with additions can obtain neutron spectral information. A schedule for further development of the system is presented

  19. Interrogative suggestibility in opiate users.

    Science.gov (United States)

    Murakami, A; Edelmann, R J; Davis, P E

    1996-09-01

    The present study investigated interrogative suggestibility in opiate users. A group of patients undergoing a methadone detoxification programme in an in-patient drug treatment unit (Detox group, n = 21), and a group of residents who had come off drugs and were no longer suffering from withdrawal syndrome (Rehab group, n = 19) were compared on interrogative suggestibility and various other psychological factors. Significant differences were found between the two groups, with the Detox group having more physical and psychological problems, and a higher total suggestibility score in comparison with the Rehab group. These findings are discussed in relation to the context of police interrogations and the reliability of confessions made by suspects and witnesses dependent on opiates.

  20. Optimization of combined delayed neutron and differential die-away prompt neutron signal detection for characterization of spent nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Blanc, Pauline; Tobin, Stephen J.; Croft, Stephen; Menlove, Howard O.; Swinhoe, M.; Lee, T.

    2010-01-01

    The Next Generation Safeguards Initiative (NGSI) of the U.S. Department of Energy (DOE) has funded multiple laboratories and universities to develop a means to accurately quantify the Plutonium (Pu) mass in spent nuclear fuel assemblies and ways to also detect potential diversion of fuel pins. Delayed Neutron (DN) counting provides a signature somewhat more sensitive to 235 U than Pu while Differential Die-Away (DDA) is complementary in that it has greater sensitivity to Pu. The two methods can, with care, be combined into a single instrument which also provides passive neutron information. Individually the techniques cannot robustly quantify the Pu content but coupled together the information content in the signatures enables Pu quantification separate to the total fissile content. The challenge of merging DN and DDA, prompt neutron (PN) signal, capabilities in the same design is the focus of this paper. Other possibilities also suggest themselves, such as a direct measurement of the reactivity (multiplication) by either the boost in signal obtained during the active interrogation itself or by the extension of the die-away profile. In an early study, conceptual designs have been modeled using a neutron detector comprising fission chambers or 3He proportional counters and a ∼14 MeV neutron Deuterium-Tritium (DT) generator as the interrogation source. Modeling was performed using the radiation transport code Monte Carlo N-Particles eXtended (MCNPX). Building on this foundation, the present paper quantifies the capability of a new design using an array of 3 He detectors together with fission chambers to optimize both DN and PN detections and active characterization, respectively. This new design was created in order to minimize fission in 238 U (a nuisance DN emitter), to use a realistic neutron generator, to reduce the cost and to achieve near spatial interrogation and detection of the DN and PN, important for detection of diversion, all within the constraints of

  1. Language style matching and police interrogation outcomes

    NARCIS (Netherlands)

    Richardson, Beth H.; Taylor, Paul J; Snook, Brent; Conchie, Stacey M.; Bennell, Craig

    2014-01-01

    This research examined the coordination of interrogator and suspects’ verbal behavior in interrogations. Sixty-four police interrogations were examined at the aggregate and utterance level using a measure of verbal mimicry known as Language Style Matching. Analyses revealed an interaction between

  2. 8 CFR 343b.3 - Interrogation.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Interrogation. 343b.3 Section 343b.3 Aliens... NATURALIZATION FOR RECOGNITION BY A FOREIGN STATE § 343b.3 Interrogation. When Form N-565 presents a prima facie... issuance of the certificate. Interrogation of the applicant shall be conducted before the application is...

  3. Rattling nucleons: New developments in active interrogation of special nuclear material

    International Nuclear Information System (INIS)

    Runkle, Robert C.; Chichester, David L.; Thompson, Scott J.

    2012-01-01

    Active interrogation is a vigorous area of research and development due to its promise of offering detection and characterization capabilities of special nuclear material in environments where passive detection fails. The primary value added by active methods is the capability to penetrate shielding - special nuclear material itself, incidental materials, or intentional shielding - and advocates hope that active interrogation will provide a solution to the problem of detecting shielded uranium, which is at present the greatest obstacle to interdiction efforts. The technique also provides a unique benefit for quantifying nuclear material in high background-radiation environments, an area important for nuclear material safeguards and material accountancy. Progress has been made in the field of active interrogation on several fronts, most notably in the arenas of source development, systems integration, and the integration and exploitation of multiple fission and non-fission signatures. But penetration of interrogating radiation often comes at a cost, not only in terms of finance and dose but also in terms of induced backgrounds, system complexity, and extended measurement times (including set up and acquisition). These costs make the calculus for deciding to implement active interrogation more subtle than may be apparent. The purpose of this review is thus to examine existing interrogation methods, compare and contrast their attributes and limitations, and identify missions where active interrogation may hold the most promise.

  4. Fast digitization and discrimination of prompt neutron and photon signals using a novel silicon carbide detector

    International Nuclear Information System (INIS)

    Brandon W. Blackburn; James T. Johnson; Scott M. Watson; David L. Chichester; James L. Jones; Frank H. Ruddy; John G. Seidel; Robert W. Flammang

    2007-01-01

    Current requirements of some Homeland Security active interrogation projects for the detection of Special Nuclear Material (SNM) necessitate the development of faster inspection and acquisition capabilities. In order to do so, fast detectors which can operate during and shortly after intense interrogation radiation flashes are being developed. Novel silicon carbide (SiC) semiconductor Schottky diodes have been utilized as robust neutron and photon detectors in both pulsed photon and pulsed neutron fields and are being integrated into active inspection environments to allow exploitation of both prompt and delayed emissions. These detectors have demonstrated the capability of detecting both photon and neutron events during intense photon flashes typical of an active inspection environment. Beyond the inherent insensitivity of SiC to gamma radiation, fast digitization and processing has demonstrated that pulse shape discrimination (PSD) in combination with amplitude discrimination can further suppress unwanted gamma signals and extract fast neutron signatures. Usable neutron signals have been extracted from mixed radiation fields where the background has exceeded the signals of interest by >1000:1

  5. AWG Filter for Wavelength Interrogator

    Science.gov (United States)

    Black, Richard J. (Inventor); Costa, Joannes M. (Inventor); Faridian, Fereydoun (Inventor); Moslehi, Behzad (Inventor); Sotoudeh, Vahid (Inventor)

    2015-01-01

    A wavelength interrogator is coupled to a circulator which couples optical energy from a broadband source to an optical fiber having a plurality of sensors, each sensor reflecting optical energy at a unique wavelength and directing the reflected optical energy to an AWG. The AWG has a detector coupled to each output, and the reflected optical energy from each grating is coupled to the skirt edge response of the AWG such that the adjacent channel responses form a complementary pair response. The complementary pair response is used to convert an AWG skirt response to a wavelength.

  6. Signature Balancing

    NARCIS (Netherlands)

    Noordkamp, H.W.; Brink, M. van den

    2006-01-01

    Signatures are an important part of the design of a ship. In an ideal situation, signatures must be as low as possible. However, due to budget constraints it is most unlikely to reach this ideal situation. The arising question is which levels of signatures are optimal given the different scenarios

  7. Interrogative suggestibility in patients with conversion disorders.

    Science.gov (United States)

    Foong, J; Lucas, P A; Ron, M A

    1997-09-01

    We tested the hypothesis that increased interrogative suggestibility may contribute to the shaping and maintaining of conversions symptoms. Interrogative suggestibility was measured in 12 patients with conversion disorder and 10 control patients with confirmed neurological disease matched for age, premorbid intelligence, and as closely as possible in terms of their neurological symptoms to the patients with conversion disorder. Our observations do not support the contention that individual differences in interrogative suggestibility are of importance in the etiology of conversion disorders.

  8. Physical description of nuclear materials identification system (NMIS) signatures

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; Mullens, J.A.; Mattingly, J.K.; Valentine, T.E.

    2000-01-01

    This paper describes all time and frequency analysis parameters measured with a new correlation processor (capability up to 1 GHz sampling rates and up to five input data channels) for three input channels: (1) the 252 Cf source ionization chamber; (2) a detection channel; and (3) a second detection channel. An intuitive and physical description of the various measured quantities is given as well as a brief mathematical description and a brief description of how the data are acquired. If the full five-channel capability is used, the number of measured quantities increases in number but not in type. The parameters provided by this new processor can be divided into two general classes: time analysis signatures and their related frequency analysis signatures. The time analysis signatures include the number of time m pulses occurs in a time interval, that is triggered randomly, upon a detection event, or upon a source fission event triggered. From the number of pulses in a time interval, the moments, factorial moments, and Feynmann variance can be obtained. Recent implementations of third- and fourth-order time and frequency analysis signatures in this processor are also briefly described. Thus, this processor used with a timed source of input neutrons contains all of the information from a pulsed neutron measurement, one and two detector Rossi-α measurements, multiplicity measurements, and third- and fourth-order correlation functions. This processor, although originally designed for active measurements with a 252 Cf interrogating source, has been successfully used passively (without 252 Cf source) for systems with inherent neutron sources such as fissile systems of plutonium. Data from active measurements with an 18.75 kg highly enriched uranium (93.2 wt%, 235 U) metal casting for storage are presented to illustrate some of the various time and frequency analysis parameters. This processor, which is a five-channel time correlation analyzer with time channel widths

  9. Bright Lights and Questions: Using Mutual Interrogation

    Science.gov (United States)

    Adam, Aishikin; Alangui, Willy; Barton, Bill

    2010-01-01

    Mutual Interrogation is a research methodology for ethnomathematics proposed by Alangui in 2006 in an attempt to avoid the potential inequality set up when a restricted cultural practice is viewed through the lens of the near-universal and highly developed research domain of mathematics. Using three significant examples of mutual interrogation in…

  10. Interrogative constructions in Danish Sign Language (DSL)

    DEFF Research Database (Denmark)

    Hansen, Julie

    This study investigates the primary types of interrogative constructions: Polar and content questions. The aim is to identify how and in which types of interrogative constructions the non-manual patterns described by Engberg-Pedersen (1993, 1998)are used. Furthermore, the aim is to identify...

  11. Integrated Box Interrogation System (IBIS) Preliminary Design Study

    Energy Technology Data Exchange (ETDEWEB)

    DR. Stephen Croft; Mr. David Martancik; Dr. Brian Young; Dr. Patrick MJ Chard; Dr. Robert J Estop; Sheila Melton; Gaetano J. Arnone

    2003-01-13

    Canberra Industries has won the tendered solicitation, INEEL/EST-99-00121 for boxed waste Nondestructive Assay Development and Demonstration. Canberra will provide the Integrated Box Interrogation System (IBIS) which is a suite of assay instrumentation and a data reduction system that addresses the measurement needs for Boxed Wastes identified in the solicitation and facilitates the associated experimental program and demonstration of system capability. The IBIS system will consist of the next generation CWAM system, i.e. CWAM II, which is a Scanning Passive/Active Neutron interrogation system which we will call a Box Segmented Neutron Scanner (BSNS), combined with a physically separate Box Segmented Gamma-ray Scanning (BSGS) system. These systems are based on existing hardware designs but will be tailored to the large sample size and enhanced to allow the program to evaluate the following measurement criteria:Characterization and correction for matrix heterogeneity Characterization of non-uniform radio-nuclide and isotopic compositions Assay of high density matrices (both high-Z and high moderator contents)Correction for radioactive material physical form - such as self shielding or multiplication effects due to large accumulations of radioactive materials.Calibration with a minimal set of reference standards and representative matrices.THis document summarizes the conceptual design parameters of the IBIS and indicates areas key to the success of the project where development is to be centered. The work presented here is a collaborative effort between scientific staff within Canberra and within the NIS-6 group at LANL.

  12. Integrated Box Interrogation System (IBIS) Preliminary Design Study

    International Nuclear Information System (INIS)

    Croft, Stephen; Martancik, David; Young, Brian; Chard MJ, Patrick; Estop J, Robert; Sheila Melton; Arnone, Gaetano J.

    2003-01-01

    Canberra Industries has won the tendered solicitation, INEEL/EST-99-00121 for boxed waste Nondestructive Assay Development and Demonstration. Canberra will provide the Integrated Box Interrogation System (IBIS) which is a suite of assay instrumentation and a data reduction system that addresses the measurement needs for Boxed Wastes identified in the solicitation and facilitates the associated experimental program and demonstration of system capability. The IBIS system will consist of the next generation CWAM system, i.e. CWAM II, which is a Scanning Passive/Active Neutron interrogation system which we will call a Box Segmented Neutron Scanner (BSNS), combined with a physically separate Box Segmented Gamma-ray Scanning (BSGS) system. These systems are based on existing hardware designs but will be tailored to the large sample size and enhanced to allow the program to evaluate the following measurement criteria:Characterization and correction for matrix heterogeneity Characterization of non-uniform radio-nuclide and isotopic compositions Assay of high density matrices (both high-Z and high moderator contents)Correction for radioactive material physical form - such as self shielding or multiplication effects due to large accumulations of radioactive materials.Calibration with a minimal set of reference standards and representative matrices.THis document summarizes the conceptual design parameters of the IBIS and indicates areas key to the success of the project where development is to be centered. The work presented here is a collaborative effort between scientific staff within Canberra and within the NIS-6 group at LANL

  13. Description and performance characteristics for the neutron Coincidence Collar for the verification of reactor fuel assemblies

    International Nuclear Information System (INIS)

    Menlove, H.O.

    1981-08-01

    An active neutron interrogation method has been developed for the measurement of 235 U content in fresh fuel assemblies. The neutron Coincidence Collar uses neutron interrogation with an AmLi neutron source and coincidence counting the induced fission reaction neutrons from the 235 U. This manual describes the system components, operation, and performance characteristics. Applications of the Coincidence Collar to PWR and BWR types of reactor fuel assemblies are described

  14. Wireless interrogation of passive antenna sensors

    International Nuclear Information System (INIS)

    Deshmukh, S; Huang, H

    2010-01-01

    Recently, we discovered that the resonant frequency of a microstrip patch antenna is sensitive to mechanical strains or crack presence in the ground plane. Based on this principle, antenna sensors have been demonstrated to measure strain and detect crack in metallic structures. This paper presents a wireless method to remotely interrogate a dual-frequency antenna sensor. An interrogation horn antenna was used to irradiate the antenna sensor with a linear chirp microwave signal. By implementing a light-activated switch at the sensor node and performing signal processing of the backscattered signals, the resonant frequencies of the antenna sensor along both polarizations can be measured remotely. Since the antenna sensor does not need a local power source and can be interrogated wirelessly, electric wiring can be eliminated. The sensor implementation, the signal processing and the experimental setup that validate the remote interrogation of the antenna sensor are presented. A power budget model has also been established to estimate the maximum interrogation range

  15. 32 CFR 637.21 - Recording interviews and interrogations.

    Science.gov (United States)

    2010-07-01

    ... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.21 Recording interviews and interrogations. The recording of interviews and interrogations by military police personnel is...

  16. Contraband detection with fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Buffler, Andy E-mail: abuffler@science.uct.ac.za

    2004-11-01

    Recent terror events and the increase in the trade of illicit drugs have fuelled the exploration of the use of fast neutrons as probes for the detection of hidden contraband, especially explosives, in packages ranging in size from small mail items to cargo containers. The various approaches using fast neutrons for contraband detection, presently under development, are reviewed. The role that a neutron system might play in the non-intrusive interrogation of airline luggage is discussed.

  17. Energy–angle correlation of neutrons and gamma-rays emitted from an HEU source

    Energy Technology Data Exchange (ETDEWEB)

    Miloshevsky, G., E-mail: gennady@purdue.edu; Hassanein, A.

    2014-06-01

    Special Nuclear Materials (SNM) yield very unique fission signatures, namely correlated neutrons and gamma-rays. A major challenge is not only to detect, but also to rapidly identify and recognize SNM with certainty. Accounting for particle multiplicity and correlations is one of standard ways to detect SNM. However, many parameter data such as joint distributions of energy, angle, lifetime, and multiplicity of neutrons and gamma-rays can lead to better recognition of SNM signatures in the background radiation noise. These joint distributions are not well understood. The Monte Carlo simulations of the transport of neutrons and gamma-rays produced from spontaneous and interrogation-induced fission of SNM are carried out using the developed MONSOL computer code. The energy spectra of neutrons and gamma-rays from a bare Highly Enriched Uranium (HEU) source are investigated. The energy spectrum of gamma-rays shows spectral lines by which HEU isotopes can be identified, while those of neutrons do not show any characteristic lines. The joint probability density function (JPDF) of the energy–angle association of neutrons and gamma-rays is constructed. Marginal probability density functions (MPDFs) of energy and angle are derived from JPDF. A probabilistic model is developed for the analysis of JPDF and MPDFs. This probabilistic model is used to evaluate mean values, standard deviations, covariance and correlation between the energy and angle of neutrons and gamma-rays emitted from the HEU source. For both neutrons and gamma-rays, it is found that the energy–angle variables are only weakly correlated.

  18. Incorporation of Photon Analysis into an Active Interrogation System for Shielded Uranium Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Canion, Bonnie E. [Univ. of Texas, Austin, TX (United States)

    2016-02-01

    The main goal of this project is to investigate how photon and neutron signatures from an Associated Particle Imaging (API) Deuterium-Tritium (DT) neutron generator detector system can be used to non-destructively predict the enrichment of uranium in an unknown configuration of shielded uranium.

  19. Catching the Cyber Spy: ARL's Interrogator

    National Research Council Canada - National Science Library

    Long, Kerry S

    2004-01-01

    The U.S. Army Research Laboratory has designed a network-based intrusion detection framework, Interrogator, which addresses the constantly changing threat environment that Department of Defense networks...

  20. Police interrogations through the prism of science

    Directory of Open Access Journals (Sweden)

    Igor Areh

    2016-03-01

    Full Text Available Several approaches can be employed for information gathering from human sources, differing in their theoretical basis, goals, realisation, and ethical acceptability. The paper critically presents and compares two prevalent approaches to suspect interrogation used by the police. The older, prevalent interrogation approach focuses on obtaining suspects’ incriminating statements and admissions, which severely elevates the risk of false confessions. Consequently, this interrogation approach is termed accusatorial or coercive since suspects are forced to admit to a crime. The newer interrogation approach is the information-gathering approach, also known as the investigative interview. It focuses on gathering accurate information in order to exclude or accuse a suspect in a criminal investigation. In comparison with coercive interrogation models, the information-gathering approach has a lower probability of false confessions since suspects are exposed to significantly lower levels of psychological pressure. Moreover, it is ethically more acceptable, has scientific grounds, enables the gathering of more accurate information, and has been found to be at least as effective as the coercive approach in criminal investigations. The investigative interview relies mainly on findings from social psychology. An analysis of coercive interrogation models reveals that they have no scientific basis and as such rely mainly on uncorroborated common-sense assumptions from authorities. In developed countries, coercive interrogation models are increasingly being replaced by the information-gathering approach, a trend connected with the enforcement of high human rights standards and a higher awareness of risks associated with coercive interrogation methods by the general public, academia, and professionals alike.

  1. Prototype Stilbene Neutron Collar

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shumaker, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Snyderman, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Verbeke, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wong, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-26

    A neutron collar using stilbene organic scintillator cells for fast neutron counting is described for the assay of fresh low enriched uranium (LEU) fuel assemblies. The prototype stilbene collar has a form factor similar to standard He-3 based collars and uses an AmLi interrogation neutron source. This report describes the simulation of list mode neutron correlation data on various fuel assemblies including some with neutron absorbers (burnable Gd poisons). Calibration curves (doubles vs 235U linear mass density) are presented for both thermal and fast (with Cd lining) modes of operation. It is shown that the stilbene collar meets or exceeds the current capabilities of He-3 based neutron collars. A self-consistent assay methodology, uniquely suited to the stilbene collar, using triples is described which complements traditional assay based on doubles calibration curves.

  2. Investigation of Active Interrogation Techniques to Detect Special Nuclear Material in Maritime Environments

    International Nuclear Information System (INIS)

    Miller, Thomas Martin; Patton, Bruce W.

    2010-01-01

    The detection and interdiction of special nuclear material (SNM) is still a high-priority focus area for many organizations around the world. One method that is commonly considered a leading candidate in the detection of SNM is active interrogation (AI). AI is different from its close relative, passive interrogation, in that an active source is used to enhance or create a detectable signal (usually fission) from SNM, particularly in shielded scenarios or scenarios where the SNM has a low activity. The use of AI thus makes the detection of SNM easier or, in some scenarios, even enables previously impossible detection. In this work the signal from prompt neutrons and photons as well as delayed neutrons and photons will be combined, as is typically done in AI. In previous work AI has been evaluated experimentally and computationally. However, for the purposes of this work, past scenarios are considered lightly shielded and tightly coupled spatially. At most, the previous work interrogated the contents of one standard cargo container (2.44 x 2.60 x 6.10 m) and the source and detector were both within a few meters of the object being interrogated. A few examples of this type of previous work can be found in references 1 and 2. Obviously, more heavily shielded AI scenarios will require larger source intensities, larger detector surface areas (larger detectors or more detectors), greater detector efficiencies, longer count times, or some combination of these.

  3. Electronics system for transuranic waste assays using a photon interrogation technique

    International Nuclear Information System (INIS)

    Johnson, L.O.; Lawrence, R.S.

    1979-12-01

    This report documents the development of electronics for a neutron detection system used in experiments to demonstrate the feasibility of a photon interrogation technique for transuranic (TRU) waste assays. The system consists of the neutron detection and signal conditioning circuits, variable time-gate generators, and a data acquisition system. The data acquisition system is configured using commercially available scalers, timers, teletype, and control components. The remainder of the system, with the exception of the neutron detectors, uses components designed in-house. The neutron detection system consists of 3 He proportional counters installed in a polyethylene moderator assembly. The counters are direct-coupled to a high-count-rate, current-sensitive preamplifier. The preamplifier and an additional two-stage amplifier are also installed in the moderator assembly. Signal conditioning includes baseline restoration and fast discrimination. A variable time-gate generator with logic gates allows for separation of prompt and delayed neutron counts, and generation of prompt and delayed deadtimes. The 3 He proportional counters will detect not only the neutrons from the TRU waste sample, but also the high-energy photons used to induce fission in the sample. The burst of photons (gamma flash) tends to overload and paralyze the electronics. This system has been designed to recover from a worst-case gamma flash overload within 10 microseconds. The system has met all the requirements generated for the photon interrogation experiments

  4. New electronically black neutron detectors

    International Nuclear Information System (INIS)

    Drake, D.M.; Feldman, W.C.; Hurlbut, C.

    1986-03-01

    Two neutron detectors are described that can function in a continuous radiation background. Both detectors identify neutrons by recording a proton recoil pulse followed by a characteristic capture pulse. This peculiar signature indicates that the neutron has lost all its energy in the scintillator. Resolutions and efficiencies have been measured for both detectors

  5. Micro elements for interrogating magnetoelastic sensors

    KAUST Repository

    Liang, Cai

    2011-11-01

    This paper reports a new approach for interrogating a magnetoelastic sensor\\'s resonant frequency. Previously, the frequency of a magnetoelastic sensor was measured by using a large-scale solenoid coil of at least some millimeters both in diameter and length. Planar structures of straight-line and rectangular spiral coil are designed, fabricated and tested to interrogate the resonant frequency of a magnetoelastic sensor. A sensor of 4 mm length is measured to have a resonant frequency of 551 kHz in air. The ability to interrogate a magnetoelastic sensor with such microscale elements is a step towards the miniaturization of a magnetoelastic sensor system and integration of such a system in a microfluidics device. © 2011 IEEE.

  6. Fissile and fertile nuclear material measurements using a new differential die-away self-interrogation technique

    International Nuclear Information System (INIS)

    Menlove, H.O.; Menlove, S.H.; Tobin, S.J.

    2009-01-01

    This paper presents a new technique for the measurement of fissile and fertile nuclear materials in spent fuel and plutonium-laden materials such as mixed oxide (MOX) fuel. The technique, called differential die-away self-interrogation, is similar to traditional differential die-away analysis, but it does not require a pulsed neutron generator or pulsed beam accelerator, and it can measure the fertile mass in addition to the fissile mass. The new method uses the spontaneous fission neutrons from 244 Cm in spent fuel and 240 Pu effective neutrons in MOX as the 'pulsed' neutron source, with an average of ∼2.7 neutrons per pulse. The time-correlated neutrons from the spontaneous fission and the subsequent induced fissions are analyzed as a function of time to determine the spontaneous fission rate, the induced fast-neutron fissions, and the induced thermal-neutron fissions. The fissile mass is determined from the induced thermal-neutron fissions that are produced by reflected thermal neutrons that originated from the spontaneous fission reaction. The sensitivity of the fissile mass measurement is enhanced by the use of two measurements, with and without a cadmium liner between the sample and a hydrogenous moderator that surrounds the sample. The fertile mass is determined from the multiplicity analysis of the neutrons detected soon after the initial triggering neutron is detected. The method obtains good sensitivity by the optimal design of two different neutron die-away regions: a short die-away for the neutron detector region and a longer die-away for the sample interrogation region.

  7. Radiation signatures

    International Nuclear Information System (INIS)

    McGlynn, S.P.; Varma, M.N.

    1992-01-01

    A new concept for modelling radiation risk is proposed. This concept is based on the proposal that the spectrum of molecular lesions, which we dub ''the radiation signature'', can be used to identify the quality of the causal radiation. If the proposal concerning radiation signatures can be established then, in principle, both prospective and retrospective risk determination can be assessed on an individual basis. A major goal of biophysical modelling is to relate physical events such as ionization, excitation, etc. to the production of radiation carcinogenesis. A description of the physical events is provided by track structure. The track structure is determined by radiation quality, and it can be considered to be the ''physical signature'' of the radiation. Unfortunately, the uniqueness characteristics of this signature are dissipated in biological systems in ∼10 -9 s. Nonetheless, it is our contention that this physical disturbance of the biological system eventuates later, at ∼10 0 s, in molecular lesion spectra which also characterize the causal radiation. (author)

  8. Detection of actinides with an electron accelerator by active photoneutron interrogation measurements

    International Nuclear Information System (INIS)

    Sari, A.; Carrel, F.; Gmar, M.; Laine, F.; Normand, S.; Lyoussi, A.

    2012-01-01

    The solution for management of a nuclear waste package is chosen according to its radiological characteristics. One of the most important of these features is the α-activity which is due to actinides ( 235 U, 238 U, 239 Pu, etc.) If non-destructive passive methods are not sufficient to quantify the latter, non-destructive active methods based on the fission process represent a solution of interest. First, these methods consist in irradiating a package in order to induce fission reactions on the actinides, and then, to detect the prompt and delayed particles which are emitted following these reactions. Our aim is to conduct neutron interrogation measurements on nuclear waste packages using an electron accelerator as a photoneutron generator. One of the main interests of this approach is that the intensity of the neutron flux can be one or two orders of magnitude higher than the one delivered by a deuterium-tritium generator. With the objective of improving nuclear waste characterization, the development of this method could enable the integration of three complementary techniques on a single measurement cell (active neutron interrogation, active photon interrogation, and high-energy imaging). In this paper, simulation and experimental results are presented. A simulation study using MCNPX has been conducted in order to determine the characteristics of the photoneutron flux emitted by the electron accelerator of the SAPHIR facility owned by CEA LIST. Energy spectra, angular distribution and intensity of the photoneutron flux have been obtained. A photoneutron interrogation measurement cell based on this accelerator has been built and assessed by carrying out measurements on uranium samples. Delayed gamma-ray spectra have been acquired and enabled to confirm the experimental feasibility of our method. (authors)

  9. Advanced FBG sensing through rapid spectral interrogation

    Science.gov (United States)

    Kunzler, Wesley; Newman, Jason; Wilding, Daniel; Zhu, Zixu; Lowder, Tyson; Selfridge, Richard; Schultz, Stephen; Wirthlin, Michael

    2008-03-01

    A fiber Brag grating sensor interrogator has been developed which is capable of gathering vectors of information from individual fiber Bragg gratings by capturing the full optical spectrum 3 kHz. Using a field programmable gate array with high speed digital-to-analog converters and analog-to-digital components, plus a kilohertz rate MEMS optical filter, the optical spectrum can be scanned at rates in excess of 10 million nanometers per second, allowing sensor sampling rates of many kilohertz while maintaining the necessary resolution to understand sensor changes. The autonomous system design performs all necessary detection and processing of multiple sensors and allows spectral measurements to be exported as fast as Ethernet, USB, or RS232 devices can receive it through a memory mapped interface. The high speed - full spectrum - fiber Bragg grating sensor interrogator enables advanced interrogation of dynamic strain and temperature gradients along the length of a sensor, as well as the use of each sensor for multiple stimuli, such as in temperature compensation. Two examples are described, showing interrogation of rapid laser heating in an optical fiber, as well as complex strain effects in a beam that had an engineered defect.

  10. Interrogative Suggestibility in an Adolescent Forensic Occupation.

    Science.gov (United States)

    Richardson, G.; And Others

    1995-01-01

    Sixty-five juvenile offenders in residential care completed the Gudjonsson Suggestibility Scale, and their scores were matched for IQ and memory with those of 60 adult offenders. The juveniles gave in significantly more to interrogative pressure through negative feedback but were no more yielding to leading questions than adults. (JPS)

  11. Interrogative suggestibility and perceptual motor performance.

    Science.gov (United States)

    Gudjonsson, G H

    1984-04-01

    This study investigates the relationship between interrogative suggestibility, as measured by the Gudjonsson Suggestibility Scale, and Arrow-Dot scores. The tendency of subjects (25 men and 25 women, mean age 30.2 yr.) to alter their answers once interpersonal pressure had been applied correlated significantly with poor Arrow-Dot Ego functioning.

  12. Photon interrogation annual report for FY 1979

    International Nuclear Information System (INIS)

    Nieschmidt, E.B.; Johnson, L.O.; Lawrence, R.S.; Vegors, S.H. Jr.

    1980-03-01

    Summaries of experimental information and information from vendors is presented to show the adequacy of the photon interrogation technique for transuranic waste assay. An instrument system is described which has high immunity to gamma flash and has good high count rate capabilities. Comparison of the progress of the program with a schedule presented at its inception is presented

  13. Micro elements for interrogating magnetoelastic sensors

    KAUST Repository

    Liang, Cai; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen; Mathison, Leslie C.; Chin, Bryan

    2011-01-01

    and length. Planar structures of straight-line and rectangular spiral coil are designed, fabricated and tested to interrogate the resonant frequency of a magnetoelastic sensor. A sensor of 4 mm length is measured to have a resonant frequency of 551 kHz in air

  14. Rheo: Japanese Sound Art Interrogating Digital Mediality

    DEFF Research Database (Denmark)

    Vandsø, Anette

    2014-01-01

    THe article asks in what way the Japanese sound artist Ryoichi Kurokawa's audiovisual installation Rheo 5 Horisonz (2010) is 'digital'. Using Professor Lars Elleströms concept of 'mediality, the main claim in this article is that Rheo no only uses digital tehcnology, but also interrogates digital...

  15. Effect of External Vibration on PZT Impedance Signature

    Directory of Open Access Journals (Sweden)

    Yaowen Yang

    2008-11-01

    Full Text Available Piezoelectric ceramic Lead Zirconate Titanate (PZT transducers, working on the principle of electromechanical impedance (EMI, are increasingly applied for structural health monitoring (SHM in aerospace, civil and mechanical engineering. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in the electromechanical admittance (inverse of EMI signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the monitored structure is only excited by the PZT transducers for the interrogating of EMI signature, while the vibration of the structure caused by the external excitations other than the PZT actuation is not considered. However, many structures work under vibrations in practice. To monitor such structures, issues related to the effects of vibration on the EMI signature need to be addressed because these effects may lead to misinterpretation of the structural health. This paper develops an EMI model for beam structures, which takes into account the effect of beam vibration caused by the external excitations. An experimental study is carried out to verify the theoretical model. A lab size specimen with different external excitations is tested and the effect of vibration on EMI signature is discussed.

  16. Effect of External Vibration on PZT Impedance Signature.

    Science.gov (United States)

    Yang, Yaowen; Miao, Aiwei

    2008-11-01

    Piezoelectric ceramic Lead Zirconate Titanate (PZT) transducers, working on the principle of electromechanical impedance (EMI), are increasingly applied for structural health monitoring (SHM) in aerospace, civil and mechanical engineering. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in the electromechanical admittance (inverse of EMI) signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the monitored structure is only excited by the PZT transducers for the interrogating of EMI signature, while the vibration of the structure caused by the external excitations other than the PZT actuation is not considered. However, many structures work under vibrations in practice. To monitor such structures, issues related to the effects of vibration on the EMI signature need to be addressed because these effects may lead to misinterpretation of the structural health. This paper develops an EMI model for beam structures, which takes into account the effect of beam vibration caused by the external excitations. An experimental study is carried out to verify the theoretical model. A lab size specimen with different external excitations is tested and the effect of vibration on EMI signature is discussed.

  17. Adaptive interrogation for 3D-PIV

    International Nuclear Information System (INIS)

    Novara, Matteo; Scarano, Fulvio; Ianiro, Andrea

    2013-01-01

    A method to adapt the shape and orientation of interrogation volumes for 3D-PIV motion analysis is introduced, aimed to increase the local spatial resolution. The main application of this approach is the detailed analysis of complex 3D and vortex-dominated flows that exhibit high vorticity in confined regions like shear layers and vortex filaments. The adaptive criterion is based on the analysis of the components of the local velocity gradient tensor, which returns the level of anisotropy of velocity spatial fluctuations. The principle to increase the local spatial resolution is based on the deformation of spherical isotropic interrogation regions, obtained by means of Gaussian weighting, into ellipsoids, with free choice of the principal axes and their directions. The interrogation region is contracted in the direction of the maximum velocity variation and elongated in the minimum one in order to maintain a constant interrogation volume. The adaptivity technique for three-dimensional PIV data takes advantage of the 3D topology of the flow, allowing increasing the spatial resolution not only in the case of shear layers, but also for vortex filaments, which is not possible for two-dimensional measurement in the plane normal to the vortex axis. The definition of the ellipsoidal interrogation region semi-axes is based on the singular values and singular directions of the local velocity gradient tensor as obtained by the singular values decomposition technique (SVD). The working principle is verified making use of numerical simulations of a shear layer and of a vortex filament. The application of the technique to data from a Tomo-PIV experiment conducted on a round jet, shows that the resolution of the shear layer at the jet exit can be considerably improved and an increase of about 25% in the vorticity peak is attained when the adaptive approach is applied. On the other hand, the peak vorticity description in the core of vortex rings is only slightly improved with

  18. Development and application of a hybrid transport methodology for active interrogation systems

    Energy Technology Data Exchange (ETDEWEB)

    Royston, K.; Walters, W.; Haghighat, A. [Nuclear Engineering Program, Department of Mechanical Engineering, Virginia Tech., 900 N Glebe Rd., Arlington, VA 22203 (United States); Yi, C.; Sjoden, G. [Nuclear and Radiological Engineering, Georgia Tech, 801 Ferst Drive, Atlanta, GA 30332 (United States)

    2013-07-01

    A hybrid Monte Carlo and deterministic methodology has been developed for application to active interrogation systems. The methodology consists of four steps: i) neutron flux distribution due to neutron source transport and subcritical multiplication; ii) generation of gamma source distribution from (n, 7) interactions; iii) determination of gamma current at a detector window; iv) detection of gammas by the detector. This paper discusses the theory and results of the first three steps for the case of a cargo container with a sphere of HEU in third-density water cargo. To complete the first step, a response-function formulation has been developed to calculate the subcritical multiplication and neutron flux distribution. Response coefficients are pre-calculated using the MCNP5 Monte Carlo code. The second step uses the calculated neutron flux distribution and Bugle-96 (n, 7) cross sections to find the resulting gamma source distribution. In the third step the gamma source distribution is coupled with a pre-calculated adjoint function to determine the gamma current at a detector window. The AIMS (Active Interrogation for Monitoring Special-Nuclear-Materials) software has been written to output the gamma current for a source-detector assembly scanning across a cargo container using the pre-calculated values and taking significantly less time than a reference MCNP5 calculation. (authors)

  19. Dual Neutral Particle Beam Interrogation of Intermodal Shipping Containers for Special Nuclear Material

    Science.gov (United States)

    Keith, Rodney Lyman

    Intermodal shipping containers entering the United States provide an avenue to smuggle unsecured or stolen special nuclear material (SNM). The only direct method fielded to indicate the presence of SNM is by passive photon/neutron radiation detection. Active interrogation using neutral particle beams to induce fission in SNM is a method under consideration. One by-product of fission is the creation of fragments that undergo radioactive decay over a time period on the order of tens of seconds after the initial event. The "delayed" gamma-rays emitted from these fragments over this period are considered a hallmark for the presence of SNM. A fundamental model is developed using homogenized cargos with a SNM target embedded at the center and computationally interrogated using simultaneous neutron and photon beams. Findings from analysis of the delayed gamma emissions from these experiments are intended to mitigate the effects of poor quality information about the composition and disposition of suspect cargo before examination in an active interrogation portal.

  20. Notes on SAW Tag Interrogation Techniques

    Science.gov (United States)

    Barton, Richard J.

    2010-01-01

    We consider the problem of interrogating a single SAW RFID tag with a known ID and known range in the presence of multiple interfering tags under the following assumptions: (1) The RF propagation environment is well approximated as a simple delay channel with geometric power-decay constant alpha >/= 2. (2) The interfering tag IDs are unknown but well approximated as independent, identically distributed random samples from a probability distribution of tag ID waveforms with known second-order properties, and the tag of interest is drawn independently from the same distribution. (3) The ranges of the interfering tags are unknown but well approximated as independent, identically distributed realizations of a random variable rho with a known probability distribution f(sub rho) , and the tag ranges are independent of the tag ID waveforms. In particular, we model the tag waveforms as random impulse responses from a wide-sense-stationary, uncorrelated-scattering (WSSUS) fading channel with known bandwidth and scattering function. A brief discussion of the properties of such channels and the notation used to describe them in this document is given in the Appendix. Under these assumptions, we derive the expression for the output signal-to-noise ratio (SNR) for an arbitrary combination of transmitted interrogation signal and linear receiver filter. Based on this expression, we derive the optimal interrogator configuration (i.e., transmitted signal/receiver filter combination) in the two extreme noise/interference regimes, i.e., noise-limited and interference-limited, under the additional assumption that the coherence bandwidth of the tags is much smaller than the total tag bandwidth. Finally, we evaluate the performance of both optimal interrogators over a broad range of operating scenarios using both numerical simulation based on the assumed model and Monte Carlo simulation based on a small sample of measured tag waveforms. The performance evaluation results not only

  1. BRIGHT 'MERGER-NOVA' FROM THE REMNANT OF A NEUTRON STAR BINARY MERGER: A SIGNATURE OF A NEWLY BORN, MASSIVE, MILLISECOND MAGNETAR

    International Nuclear Information System (INIS)

    Yu, Yun-Wei; Zhang, Bing; Gao, He

    2013-01-01

    A massive millisecond magnetar may survive the merger of a neutron star (NS) binary, which would continuously power the merger ejecta. We develop a generic dynamic model for the merger ejecta with energy injection from the central magnetar. The ejecta emission (the m erger-nova ) powered by the magnetar peaks in the UV band and the peak of the light curve, progressively shifts to an earlier epoch with increasing frequency. A magnetar-powered merger-nova could have an optical peak brightness comparable to a supernova, which is a few tens or hundreds times brighter than the radioactive-powered merger-novae (the so-called macro-nova or kilo-nova). On the other hand, such a merger-nova would peak earlier and have a significantly shorter duration than that of a supernova. An early collapse of the magnetar could suppress the brightness of the optical emission and shorten its duration. Such millisecond-magnetar-powered merger-novae may be detected from NS-NS merger events without an observed short gamma-ray burst, and could be a bright electromagnetic counterpart for gravitational wave bursts due to NS-NS mergers. If detected, it suggests that the merger leaves behind a massive NS, which has important implications for the equation-of-state of nuclear matter

  2. Signature of protein adaptation to warm deep sea environments: the case of Initiation Factor 6 studied by molecular simulation and neutron scattering

    International Nuclear Information System (INIS)

    Calligari, Paolo

    2008-01-01

    The protein Initiation Factor 6 (IF6) takes part in the protein synthesis regulation of several organisms. It was also found in archeaebacteria such as Methanococcus jannaschii which lives in deep-seas near hydrothermal vents where temperature reaches 80 C and pressure is between 250 bar and 500 bar. The aim of this work was to study for the first time dynamical and structural properties of IF6 produced by M. jannaschii and comparing them with those of the IF6 homologue present in Saccharomyces cerevisiae which lives at 'normal' environmental conditions (27 C and 1 bar). Molecular simulation gave here new insights into the adaptation of these two proteins to their respective physiological conditions and showed that the latter induced similar dynamical and structural properties: in their respective 'natural' conditions, IF6s show very similar structural fluctuations and the characteristic relaxation times which define their dynamical properties shows similar changes when comparing unfavorable conditions to physiological ones. The creation of these corresponding states between the two homologues has been interpreted by the fractional Brownian dynamics model and by a novel method for the characterization of protein secondary structures. The latter is presented here in detail together with some examples of other applications. Experimental data obtained from quasi-elastic neutron scattering seemed to support the results obtained by molecular simulations. (author) [fr

  3. Natural syntax : English interrogative main clauses

    Directory of Open Access Journals (Sweden)

    Janez Oresnik

    2007-12-01

    Full Text Available Natural Syntax is a developing deductive theory, a branch of Naturalness Theory. The naturalnessjudgements are couched in naturalness scales, whichfollow from the basic parameters (or «axioms» listed at the beginning of the paper. The predictions of the theory are calculated in deductions, whose chief components are apair of naturalness scales and the rules governing the alignment of corresponding naturalness values. Parallel and chiastic alignments are distinguished, in complementary distribution. Chiastic alignment is mandatory in deductions limited to unnatural environments. The paper deals with English interrogative main clauses. Within these, only the interrogatives containing wh-words exclusively insitu constitute an extremely unnatural environment and require chiastic alignment. Otherwiseparallel alignment is used. Earlier publications on Natural Syntax: Kavcic 2005a,b, Oresnik 1999, 2000a,b, 200la-f   2002, 2003a-c, 2002/03, 2004. This list cites only works written in English.

  4. Wirelessly Interrogated Wear or Temperature Sensors

    Science.gov (United States)

    Woodard, Stanley E.; Taylor, Bryant D.

    2010-01-01

    Sensors for monitoring surface wear and/or temperature without need for wire connections have been developed. Excitation and interrogation of these sensors are accomplished by means of a magnetic-field-response recorder. In a sensor of the present type as in the previously reported ones, the capacitance and, thus, the resonance frequency, varies as a known function of the quantity of interest that one seeks to determine. Hence, the resonance frequency is measured and used to calculate the quantity of interest.

  5. Revenge versus rapport: Interrogation, terrorism, and torture.

    Science.gov (United States)

    Alison, Laurence; Alison, Emily

    2017-04-01

    This review begins with the historical context of harsh interrogation methods that have been used repeatedly since the Second World War. This is despite the legal, ethical and moral sanctions against them and the lack of evidence for their efficacy. Revenge-motivated interrogations (Carlsmith & Sood, 2009) regularly occur in high conflict, high uncertainty situations and where there is dehumanization of the enemy. These methods are diametrically opposed to the humanization process required for adopting rapport-based methods-for which there is an increasing corpus of studies evidencing their efficacy. We review this emerging field of study and show how rapport-based methods rely on building alliances and involve a specific set of interpersonal skills on the part of the interrogator. We conclude with 2 key propositions: (a) for psychologists to firmly maintain the Hippocratic Oath of "first do no harm," irrespective of perceived threat and uncertainty, and (b) for wider recognition of the empirical evidence that rapport-based approaches work and revenge tactics do not. Proposition (a) is directly in line with fundamental ethical principles of practice for anyone in a caring profession. Proposition (b) is based on the requirement for psychology to protect and promote human welfare and to base conclusions on objective evidence. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. Quantum prisoners' dilemma under enhanced interrogation

    Science.gov (United States)

    Siopsis, George; Balu, Radhakrishnan; Solmeyer, Neal

    2018-06-01

    In the quantum version of prisoners' dilemma, each prisoner is equipped with a single qubit that the interrogator can entangle. We enlarge the available Hilbert space by introducing a third qubit that the interrogator can entangle with the other two. We discuss an enhanced interrogation technique based on tripartite entanglement and analyze Nash equilibria. We show that for tripartite entanglement approaching a W-state, we calculate the Nash equilibria numerically and show that they coincide with the Pareto-optimal choice where both prisoners cooperate. Upon continuous variation between a W-state and a pure bipartite entangled state, the game is shown to have a surprisingly rich structure. The role of bipartite and tripartite entanglement is explored to explain that structure. As an application, we consider an evolutionary game based on our quantum game with a network of agents on a square lattice with periodic boundary conditions and show that the strategy corresponding to Nash equilibrium completely dominates without placing any restrictions on the initial set of strategies.

  7. Compact neutron generator

    Science.gov (United States)

    Leung, Ka-Ngo; Lou, Tak Pui

    2005-03-22

    A compact neutron generator has at its outer circumference a toroidal shaped plasma chamber in which a tritium (or other) plasma is generated. A RF antenna is wrapped around the plasma chamber. A plurality of tritium ion beamlets are extracted through spaced extraction apertures of a plasma electrode on the inner surface of the toroidal plasma chamber and directed inwardly toward the center of neutron generator. The beamlets pass through spaced acceleration and focusing electrodes to a neutron generating target at the center of neutron generator. The target is typically made of titanium tubing. Water is flowed through the tubing for cooling. The beam can be pulsed rapidly to achieve ultrashort neutron bursts. The target may be moved rapidly up and down so that the average power deposited on the surface of the target may be kept at a reasonable level. The neutron generator can produce fast neutrons from a T-T reaction which can be used for luggage and cargo interrogation applications. A luggage or cargo inspection system has a pulsed T-T neutron generator or source at the center, surrounded by associated gamma detectors and other components for identifying explosives or other contraband.

  8. Detection of explosives by neutron scattering

    International Nuclear Information System (INIS)

    Brooks, F.D.; Buffler, A.; Allie, M.S.; Nchodu, M.R.; Bharuth-Ram, K.

    1998-01-01

    For non-intrusive detection of hidden explosives or other contraband such as narcotics a fast neutron scattering analysis (FNSA) technique is proposed. An experimental arrangement uses a collimated, pulsed beam of neutrons directed at the sample. Scattered neutrons are detected by liquid scintillation counters at different scattering angles. A scattering signature is derived from two-parameter data, counts vs pulse height and time-of-flight measured for each element (H, C, N or O) at each of two scattering angles and two neutron energies. The elemental signatures are very distinctive and constitute a good response matrix for unfolding elemental components from the scattering signatures measured for different compounds

  9. Investigations of active interrogation techniques to detect special nuclear material in maritime environments: Standoff interrogation of small- and medium-sized cargo ships

    International Nuclear Information System (INIS)

    Miller, Thomas M.; Patton, Bruce W.; Grogan, Brandon R.; Henkel, James J.; Murphy, Brian D.; Johnson, Jeffrey O.; Mihalczo, John T.

    2013-01-01

    In this work, several active interrogation (AI) sources are evaluated to determine their usefulness in detecting the presence of special nuclear material (SNM) in fishing trawlers, small cargo transport ships, and luxury yachts at large standoff distances from the AI source and detector. This evaluation is performed via computational analysis applying Monte Carlo methods with advanced variance reduction techniques. The goal is to determine the AI source strength required to detect the presence of SNM. The general conclusion of this study is that AI is not reliable when SNM is heavily shielded and not tightly coupled geometrically with the source and detector, to the point that AI should not be considered a via interrogation option in these scenarios. More specifically, when SNM is shielded by hydrogenous material large AI source strengths are required if detection is based on neutrons, which is not surprising. However, if the SNM is shielded by high-Z material the required AI source strengths are not significantly different if detection is based on neutrons or photons, which is somewhat surprising. Furthermore, some of the required AI source strengths that were calculated are very large. These results coupled with the realities of two ships moving independently at sea and other assumptions made during this analysis make the use of standoff AI in the maritime environment impractical

  10. Investigations of active interrogation techniques to detect special nuclear material in maritime environments: Standoff interrogation of small- and medium-sized cargo ships

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Thomas M., E-mail: millertm@ornl.gov; Patton, Bruce W.; Grogan, Brandon R.; Henkel, James J.; Murphy, Brian D.; Johnson, Jeffrey O.; Mihalczo, John T.

    2013-12-01

    In this work, several active interrogation (AI) sources are evaluated to determine their usefulness in detecting the presence of special nuclear material (SNM) in fishing trawlers, small cargo transport ships, and luxury yachts at large standoff distances from the AI source and detector. This evaluation is performed via computational analysis applying Monte Carlo methods with advanced variance reduction techniques. The goal is to determine the AI source strength required to detect the presence of SNM. The general conclusion of this study is that AI is not reliable when SNM is heavily shielded and not tightly coupled geometrically with the source and detector, to the point that AI should not be considered a via interrogation option in these scenarios. More specifically, when SNM is shielded by hydrogenous material large AI source strengths are required if detection is based on neutrons, which is not surprising. However, if the SNM is shielded by high-Z material the required AI source strengths are not significantly different if detection is based on neutrons or photons, which is somewhat surprising. Furthermore, some of the required AI source strengths that were calculated are very large. These results coupled with the realities of two ships moving independently at sea and other assumptions made during this analysis make the use of standoff AI in the maritime environment impractical.

  11. "Enhanced" interrogation of detainees: do psychologists and psychiatrists participate?

    OpenAIRE

    Halpern, Abraham L; Halpern, John H; Doherty, Sean B

    2008-01-01

    Abstract After revelations of participation by psychiatrists and psychologists in interrogation of prisoners at Guantánamo Bay and Central Intelligence Agency secret detention centers, the American Psychiatric Association and the American Psychological Association adopted Position Statements absolutely prohibiting their members from participating in torture under any and all circumstances, and, to a limited degree, forbidding involvement in interrogations. Some interrogations utilize very agg...

  12. A Methodology for Calculating Radiation Signatures

    Energy Technology Data Exchange (ETDEWEB)

    Klasky, Marc Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilcox, Trevor [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bathke, Charles G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); James, Michael R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-01

    A rigorous formalism is presented for calculating radiation signatures from both Special Nuclear Material (SNM) as well as radiological sources. The use of MCNP6 in conjunction with CINDER/ORIGEN is described to allow for the determination of both neutron and photon leakages from objects of interest. In addition, a description of the use of MCNP6 to properly model the background neutron and photon sources is also presented. Examinations of the physics issues encountered in the modeling are investigated so as to allow for guidance in the user discerning the relevant physics to incorporate into general radiation signature calculations. Furthermore, examples are provided to assist in delineating the pertinent physics that must be accounted for. Finally, examples of detector modeling utilizing MCNP are provided along with a discussion on the generation of Receiver Operating Curves, which are the suggested means by which to determine detectability radiation signatures emanating from objects.

  13. Infrared signatures for remote sensing

    International Nuclear Information System (INIS)

    McDowell, R.S.; Sharpe, S.W.; Kelly, J.F.

    1994-04-01

    PNL's capabilities for infrared and near-infrared spectroscopy include tunable-diode-laser (TDL) systems covering 300--3,000 cm -1 at 2 laser. PNL also has a beam expansion source with a 12-cm slit, which provides a 3-m effective path for gases at ∼10 K, giving a Doppler width of typically 10 MHz; and long-path static gas cells (to 100 m). In applying this equipment to signatures work, the authors emphasize the importance of high spectral resolution for detecting and identifying atmospheric interferences; for identifying the optimum analytical frequencies; for deriving, by spectroscopic analysis, the molecular parameters needed for modeling; and for obtaining data on species and/or bands that are not in existing databases. As an example of such spectroscopy, the authors have assigned and analyzed the C-Cl stretching region of CCl 4 at 770--800 cm -1 . This is an important potential signature species whose IR absorption has remained puzzling because of the natural isotopic mix, extensive hot-band structure, and a Fermi resonance involving a nearby combination band. Instrument development projects include the IR sniffer, a small high-sensitivity, high-discrimination (Doppler-limited) device for fence-line or downwind monitoring that is effective even in regions of atmospheric absorption; preliminary work has achieved sensitivities at the low-ppb level. Other work covers trace species detection with TDLs, and FM-modulated CO 2 laser LIDAR. The authors are planning a field experiment to interrogate the Hanford tank farm for signature species from Rattlesnake Mountain, a standoff of ca. 15 km, to be accompanied by simultaneous ground-truthing at the tanks

  14. Apparatus and method for identification of matrix materials in which transuranic elements are embedded using thermal neutron capture gamma-ray emission

    Science.gov (United States)

    Close, D.A.; Franks, L.A.; Kocimski, S.M.

    1984-08-16

    An invention is described that enables the quantitative simultaneous identification of the matrix materials in which fertile and fissile nuclides are embedded to be made along with the quantitative assay of the fertile and fissile materials. The invention also enables corrections for any absorption of neutrons by the matrix materials and by the measurement apparatus by the measurement of the prompt and delayed neutron flux emerging from a sample after the sample is interrogated by simultaneously applied neutrons and gamma radiation. High energy electrons are directed at a first target to produce gamma radiation. A second target receives the resulting pulsed gamma radiation and produces neutrons from the interaction with the gamma radiation. These neutrons are slowed by a moderator surrounding the sample and bathe the sample uniformly, generating second gamma radiation in the interaction. The gamma radiation is then resolved and quantitatively detected, providing a spectroscopic signature of the constituent elements contained in the matrix and in the materials within the vicinity of the sample. (LEW)

  15. Fissile interrogation using gamma rays from oxygen

    Science.gov (United States)

    Smith, Donald; Micklich, Bradley J.; Fessler, Andreas

    2004-04-20

    The subject apparatus provides a means to identify the presence of fissionable material or other nuclear material contained within an item to be tested. The system employs a portable accelerator to accelerate and direct protons to a fluorine-compound target. The interaction of the protons with the fluorine-compound target produces gamma rays which are directed at the item to be tested. If the item to be tested contains either a fissionable material or other nuclear material the interaction of the gamma rays with the material contained within the test item with result in the production of neutrons. A system of neutron detectors is positioned to intercept any neutrons generated by the test item. The results from the neutron detectors are analyzed to determine the presence of a fissionable material or other nuclear material.

  16. Neutron stars

    International Nuclear Information System (INIS)

    Irvine, J.M.

    1978-01-01

    The subject is covered in chapters entitled: introduction (resume of stellar evolution, gross characteristics of neutron stars); pulsars (pulsar characteristics, pulsars as neutron stars); neutron star temperatures (neutron star cooling, superfluidity and superconductivity in neutron stars); the exterior of neutron stars (the magnetosphere, the neutron star 'atmosphere', pulses); neutron star structure; neutron star equations of state. (U.K.)

  17. Fission signal detection using helium-4 gas fast neutron scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, J. M., E-mail: lewisj@ufl.edu; Kelley, R. P.; Jordan, K. A. [Nuclear Engineering Program, University of Florida, Gainesville, Florida 32611 (United States); Murer, D. [Arktis Radiation Detectors Ltd., 8045 Zurich (Switzerland)

    2014-07-07

    We demonstrate the unambiguous detection of the fission neutron signal produced in natural uranium during active neutron interrogation using a deuterium-deuterium fusion neutron generator and a high pressure {sup 4}He gas fast neutron scintillation detector. The energy deposition by individual neutrons is quantified, and energy discrimination is used to differentiate the induced fission neutrons from the mono-energetic interrogation neutrons. The detector can discriminate between different incident neutron energies using pulse height discrimination of the slow scintillation component of the elastic scattering interaction between a neutron and the {sup 4}He atom. Energy histograms resulting from this data show the buildup of a detected fission neutron signal at higher energies. The detector is shown here to detect a unique fission neutron signal from a natural uranium sample during active interrogation with a (d, d) neutron generator. This signal path has a direct application to the detection of shielded nuclear material in cargo and air containers. It allows for continuous interrogation and detection while greatly minimizing the potential for false alarms.

  18. Neutronic measurements of radioactive waste; Les mesures neutroniques des dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Perot, B

    1997-12-31

    This document presents the general matters involved in the radioactive waste management and the different non destructive assays of radioactivity. The neutronic measurements used in the characterization of waste drums containing emitters are described with more details, especially the active neutronic interrogation assays with prompt or delayed neutron detection: physical principle, signal processing and evaluation of the detection limit. (author).

  19. FY09 Advanced Instrumentation and Active Interrogation Research for Safeguards

    International Nuclear Information System (INIS)

    Chichester, D.L.; Pozzi, S.A.; Seabury, E.H.; Dolan, J.L.; Flaska, M.; Johnson, J.T.; Watson, S.M.; Wharton, J.

    2009-01-01

    Multiple small-scale projects have been undertaken to investigate advanced instrumentation solutions for safeguard measurement challenges associated with advanced fuel cycle facilities and next-generation fuel reprocessing installations. These activities are in support of the U.S. Department of Energy's Fuel Cycle Research and Development program and its Materials Protection, Accounting, and Control for Transmutation (MPACT) campaign. (1) Work was performed in a collaboration with the University of Michigan (Prof. Sara Pozzi, co-PI) to investigate the use of liquid-scintillator radiation detectors for assaying mixed-oxide (MOX) fuel, to characterize its composition and to develop advanced digital pulse-shape discrimination algorithms for performing time-correlation measurements in the MOX fuel environment. This work included both simulations and experiments and has shown that these techniques may provide a valuable approach for use within advanced safeguard measurement scenarios. (2) Work was conducted in a collaboration with Oak Ridge National Laboratory (Dr. Paul Hausladen, co-PI) to evaluate the strengths and weaknesses of the fast-neutron coded-aperture imaging technique for locating and characterizing fissile material, and as a tool for performing hold-up measurements in fissile material handling facilities. This work involved experiments at Idaho National Laboratory, using MOX fuel and uranium metal, in both passive and active interrogation configurations. A complete analysis has not yet been completed but preliminary results suggest several potential uses for the fast neutron imaging technique. (3) Work was carried out to identify measurement approaches for determining nitric acid concentration in the range of 1-4 M and beyond. This work included laboratory measurements to investigate the suitability of prompt-gamma neutron activation analysis for this measurement and product reviews of other commercial solutions. Ultrasonic density analysis appears to be

  20. Observation of Neutron Skyshine from an Accelerator Based Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Franklyn, C. B. [Radiation Science Department, Necsa, PO Box 582, Pretoria 0001 (South Africa)

    2011-12-13

    A key feature of neutron based interrogation systems is the need for adequate provision of shielding around the facility. Accelerator facilities adapted for fast neutron generation are not necessarily suitably equipped to ensure complete containment of the vast quantity of neutrons generated, typically >10{sup 11} n{center_dot}s{sup -1}. Simulating the neutron leakage from a facility is not a simple exercise since the energy and directional distribution can only be approximated. Although adequate horizontal, planar shielding provision is made for a neutron generator facility, it is sometimes the case that vertical shielding is minimized, due to structural and economic constraints. It is further justified by assuming the atmosphere above a facility functions as an adequate radiation shield. It has become apparent that multiple neutron scattering within the atmosphere can result in a measurable dose of neutrons reaching ground level some distance from a facility, an effect commonly known as skyshine. This paper describes a neutron detection system developed to monitor neutrons detected several hundred metres from a neutron source due to the effect of skyshine.

  1. Some Semantic Properties of Romanian Interrogatives: "Care" and "Cine."

    Science.gov (United States)

    Vasiliu, E.

    The aim of this paper is to account for some semantic properties of Romanian interrogatives "ce" and "cine" by establishing some definite correlations between various contextual restrictions governing the use of these interrogative particles and the "meaning" which might be assigned to each of these particles in any…

  2. Optimization of periodical interrogation of transducers of radioisotope measuring systems

    International Nuclear Information System (INIS)

    Ivashchenko, A.S.; Kaznakov, V.P.; Korolev, V.M.

    1978-01-01

    Certain methods are examined of optimizing periodic interrogation of sensors connected in a definite sequence to device for data processing in a system for controlling production processes. It is shown that in designing multiinput radioisotope measurement systems with a centralized data processing, the choice of the method of organizing periodic interrogation should be made with account for the conditions existing in each specific case

  3. Laser interrogation of latent vehicle registration number

    Energy Technology Data Exchange (ETDEWEB)

    Russo, R.E. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.]|[Lawrence Livermore National Lab., CA (United States). Forensic Science Center; Pelkey, G.E. [City of Livermore Police Dept., CA (United States); Grant, P.; Whipple, R.E.; Andresen, B.D. [Lawrence Livermore National Lab., CA (United States). Forensic Science Center

    1994-09-01

    A recent investigation involved automobile registration numbers as important evidentiary specimens. In California, as in most states, small, thin metallic decals are issued to owners of vehicles each year as the registration is renewed. The decals are applied directly to the license plate of the vehicle and typically on top of the previous year`s expired decal. To afford some degree of security, the individual registration decals have been designed to tear easily; they cannot be separated from each other, but can be carefully removed intact from the metal license plate by using a razor blade. In September 1993, the City of Livermore Police Department obtained a blue 1993 California decal that had been placed over an orange 1992 decal. The two decals were being investigated as possible evidence in a case involving vehicle registration fraud. To confirm the suspicion and implicate a suspect, the department needed to known the registration number on the bottom (completely covered) 1992 decal. The authors attempted to use intense and directed light to interrogate the colored stickers. Optical illumination using a filtered white-light source partially identified the latent number. However, the most successful technique used a tunable dye laser pumped by a pulsed Nd:YAG laser. By selectively tuning the wavelength and intensity of the dye laser, backlit illumination of the decals permitted visualization of the underlying registration number through the surface of the top sticker. With optimally-tuned wavelength and intensity, 100% accuracy was obtained in identifying the sequence of latent characters. The advantage of optical techniques is their completely nondestructive nature, thus preserving the evidence for further interrogation or courtroom presentation.

  4. Infra-red signature neutron detector

    Science.gov (United States)

    Bell, Zane William [Oak Ridge, TN; Boatner, Lynn Allen [Oak Ridge, TN

    2009-10-13

    A method of detecting an activator, the method including impinging with an activator a receptor material that includes a photoluminescent material that generates infrared radiation and generation a by-product of a nuclear reaction due to the activator impinging the receptor material. The method further includes generating light from the by-product via the Cherenkov effect, wherein the light activates the photoluminescent material so as to generate the infrared radiation. Identifying a characteristic of the activator based on the infrared radiation.

  5. High reliability - low noise radionuclide signature identification algorithms for border security applications

    Science.gov (United States)

    Lee, Sangkyu

    Illicit trafficking and smuggling of radioactive materials and special nuclear materials (SNM) are considered as one of the most important recent global nuclear threats. Monitoring the transport and safety of radioisotopes and SNM are challenging due to their weak signals and easy shielding. Great efforts worldwide are focused at developing and improving the detection technologies and algorithms, for accurate and reliable detection of radioisotopes of interest in thus better securing the borders against nuclear threats. In general, radiation portal monitors enable detection of gamma and neutron emitting radioisotopes. Passive or active interrogation techniques, present and/or under the development, are all aimed at increasing accuracy, reliability, and in shortening the time of interrogation as well as the cost of the equipment. Equally important efforts are aimed at advancing algorithms to process the imaging data in an efficient manner providing reliable "readings" of the interiors of the examined volumes of various sizes, ranging from cargos to suitcases. The main objective of this thesis is to develop two synergistic algorithms with the goal to provide highly reliable - low noise identification of radioisotope signatures. These algorithms combine analysis of passive radioactive detection technique with active interrogation imaging techniques such as gamma radiography or muon tomography. One algorithm consists of gamma spectroscopy and cosmic muon tomography, and the other algorithm is based on gamma spectroscopy and gamma radiography. The purpose of fusing two detection methodologies per algorithm is to find both heavy-Z radioisotopes and shielding materials, since radionuclides can be identified with gamma spectroscopy, and shielding materials can be detected using muon tomography or gamma radiography. These combined algorithms are created and analyzed based on numerically generated images of various cargo sizes and materials. In summary, the three detection

  6. Understanding the Signature Pedagogy of the Design Studio and the Opportunities for Its Technological Enhancement

    Science.gov (United States)

    Crowther, Phillip

    2013-01-01

    This paper presents an analysis of the studio as the signature pedagogy of design education. A number of theoretical models of learning, pedagogy, and education are used to interrogate the studio for its advantages and shortcomings, and to identify opportunities for the integration of new technologies and to explore the affordances that they…

  7. 76 FR 44282 - Defense Federal Acquisition Regulation Supplement; Prohibition on Interrogation of Detainees by...

    Science.gov (United States)

    2011-07-25

    ...-AG88 Defense Federal Acquisition Regulation Supplement; Prohibition on Interrogation of Detainees by... prescribes policies prohibiting interrogation of detainees by contractor personnel, as required by section... ancillary positions, including as trainers of, and advisors to, interrogations, if the contractor personnel...

  8. Neutron detection technique

    International Nuclear Information System (INIS)

    Oblath, N.S.; Poon, A.W.P.

    2000-01-01

    The Sudbury Neutrino Observatory (SNO) has the ability to measure the total flux of all active flavors of neutrinos using the neutral current reaction, whose signature is a neutron. By comparing the rates of the neutral current reaction to the charged current reaction, which only detects electron neutrinos, one can test the neutrino oscillation hypothesis independent of solar models. It is necessary to understand the neutron detection efficiency of the detector to make use of the neutral current reaction. This report demonstrates a coincidence technique to identify neutrons emitted from the 252 Cf neutron calibration source. The source releases on average four neutrons when a 252 Cf nucleus spontaneously fissions. Each neutron is detected as a separate event when the neutron is captured by a deuteron, releasing a gamma ray of approximately 6.25 MeV. This gamma ray is in turn detected by the photomultiplier tube (PMT) array. By investigating the time and spatial separation between neutron-like events, it is possible to obtain a pure sample of neutrons for calibration study. Preliminary results of the technique applied to two calibration runs are presented

  9. Signature-based User Authentication

    OpenAIRE

    Hámorník, Juraj

    2015-01-01

    This work aims on missing handwritten signature authentication in Windows. Result of this work is standalone software that allow users to log into Windows by writing signature. We focus on security of signature authentification and best overall user experience. We implemented signature authentification service that accept signature and return user access token if signature is genuine. Signature authentification is done by comparing given signature to signature patterns by their similarity. Si...

  10. Safety and efficiency of emergency department interrogation of cardiac devices.

    Science.gov (United States)

    Neuenschwander, James F; Peacock, W Frank; Migeed, Madgy; Hunter, Sara A; Daughtery, John C; McCleese, Ian C; Hiestand, Brian C

    2016-12-01

    Patients with implanted cardiac devices may wait extended periods for interrogation in emergency departments (EDs). Our purpose was to determine if device interrogation could be done safely and faster by ED staff. Prospective randomized, standard therapy controlled, trial of ED staff device interrogation vs. standard process (SP), with 30-day follow-up. Eligibility criteria: ED presentation with a self-report of a potential device related complaint, with signed informed consent. SP interrogation was by company representative or hospital employee. Of 60 patients, 42 (70%) were male, all were white, with a median (interquartile range) age of 71 (64 to 82) years. No patient was lost to follow up. Of all patients, 32 (53%) were enrolled during business hours. The overall median (interquartile range) ED vs. SP time to interrogation was 98.5 (40 to 260) vs. 166.5 (64 to 412) minutes (P=0.013). While ED and SP interrogation times were similar during business hours, 102 (59 to 138) vs. 105 (64 to 172) minutes (P=0.62), ED interrogation times were shorter vs. SP during non-business hours; 97 (60 to 126) vs. 225 (144 to 412) minutes, P=0.002, respectively. There was no difference in ED length of stay between the ED and SP interrogation, 249 (153 to 390) vs. 246 (143 to 333) minutes (P=0.71), regardless of time of presentation. No patient in any cohort suffered an unplanned medical contact or post-discharge adverse device related event. ED staff cardiac device interrogations are faster, and with similar 30-day outcomes, as compared to SP.

  11. An adaptive sampling and windowing interrogation method in PIV

    Science.gov (United States)

    Theunissen, R.; Scarano, F.; Riethmuller, M. L.

    2007-01-01

    This study proposes a cross-correlation based PIV image interrogation algorithm that adapts the number of interrogation windows and their size to the image properties and to the flow conditions. The proposed methodology releases the constraint of uniform sampling rate (Cartesian mesh) and spatial resolution (uniform window size) commonly adopted in PIV interrogation. Especially in non-optimal experimental conditions where the flow seeding is inhomogeneous, this leads either to loss of robustness (too few particles per window) or measurement precision (too large or coarsely spaced interrogation windows). Two criteria are investigated, namely adaptation to the local signal content in the image and adaptation to local flow conditions. The implementation of the adaptive criteria within a recursive interrogation method is described. The location and size of the interrogation windows are locally adapted to the image signal (i.e., seeding density). Also the local window spacing (commonly set by the overlap factor) is put in relation with the spatial variation of the velocity field. The viability of the method is illustrated over two experimental cases where the limitation of a uniform interrogation approach appears clearly: a shock-wave-boundary layer interaction and an aircraft vortex wake. The examples show that the spatial sampling rate can be adapted to the actual flow features and that the interrogation window size can be arranged so as to follow the spatial distribution of seeding particle images and flow velocity fluctuations. In comparison with the uniform interrogation technique, the spatial resolution is locally enhanced while in poorly seeded regions the level of robustness of the analysis (signal-to-noise ratio) is kept almost constant.

  12. Electronic Signature Policy

    Science.gov (United States)

    Establishes the United States Environmental Protection Agency's approach to adopting electronic signature technology and best practices to ensure electronic signatures applied to official Agency documents are legally valid and enforceable

  13. Lesson 6: Signature Validation

    Science.gov (United States)

    Checklist items 13 through 17 are grouped under the Signature Validation Process, and represent CROMERR requirements that the system must satisfy as part of ensuring that electronic signatures it receives are valid.

  14. Exotic signatures from supersymmetry

    International Nuclear Information System (INIS)

    Hall, L.J.

    1989-08-01

    Minor changes to the standard supersymmetric model, such as soft flavor violation and R parity violation, cause large changes in the signatures. The origin of these changes and the resulting signatures are discussed. 15 refs., 7 figs., 2 tabs

  15. Dual reference point temperature interrogating method for distributed temperature sensor

    International Nuclear Information System (INIS)

    Ma, Xin; Ju, Fang; Chang, Jun; Wang, Weijie; Wang, Zongliang

    2013-01-01

    A novel method based on dual temperature reference points is presented to interrogate the temperature in a distributed temperature sensing (DTS) system. This new method is suitable to overcome deficiencies due to the impact of DC offsets and the gain difference in the two signal channels of the sensing system during temperature interrogation. Moreover, this method can in most cases avoid the need to calibrate the gain and DC offsets in the receiver, data acquisition and conversion. An improved temperature interrogation formula is presented and the experimental results show that this method can efficiently estimate the channel amplification and system DC offset, thus improving the system accuracy. (letter)

  16. Transcriptomic signatures in cartilage ageing

    Science.gov (United States)

    2013-01-01

    Introduction Age is an important factor in the development of osteoarthritis. Microarray studies provide insight into cartilage aging but do not reveal the full transcriptomic phenotype of chondrocytes such as small noncoding RNAs, pseudogenes, and microRNAs. RNA-Seq is a powerful technique for the interrogation of large numbers of transcripts including nonprotein coding RNAs. The aim of the study was to characterise molecular mechanisms associated with age-related changes in gene signatures. Methods RNA for gene expression analysis using RNA-Seq and real-time PCR analysis was isolated from macroscopically normal cartilage of the metacarpophalangeal joints of eight horses; four young donors (4 years old) and four old donors (>15 years old). RNA sequence libraries were prepared following ribosomal RNA depletion and sequencing was undertaken using the Illumina HiSeq 2000 platform. Differentially expressed genes were defined using Benjamini-Hochberg false discovery rate correction with a generalised linear model likelihood ratio test (P ageing cartilage. Conclusion There was an age-related dysregulation of matrix, anabolic and catabolic cartilage factors. This study has increased our knowledge of transcriptional networks in cartilage ageing by providing a global view of the transcriptome. PMID:23971731

  17. Rheo: Japanese sound art interrogating digital mediality

    Directory of Open Access Journals (Sweden)

    Vandsø Anette

    2014-12-01

    Full Text Available The article asks in what way the Japanese sound artist, Ryoichi Kurokawa’s audiovisual installation, Rheo: 5 Horisonz (2010, is “digital.” Using professor Lars Elleström’s concept of “mediality,” the main claim in this article is that Rheo not only uses digital technology but also interrogates digital mediality as such. This argument is pursued in an analysis of Rheo that draws in various descriptions of digital media by N. Catherine Hayles, Lev Manovic, Bolter, and Grusin among other. The article will show how the critical potential in Rheo is directed both towards digital media as a language (Meyrowitz (or a place for representation and towards the digital as a milieu (Meyrowitz or as our culture (Gere. The overall goal of the article is not just analyse this singular art work, but also to show how such a sound art work can contribute to our understanding of our own contemporary culture as a digital culture.

  18. Repetitive Interrogation of 2-Level Quantum Systems

    Science.gov (United States)

    Prestage, John D.; Chung, Sang K.

    2010-01-01

    Trapped ion clocks derive information from a reference atomic transition by repetitive interrogations of the same quantum system, either a single ion or ionized gas of many millions of ions. Atomic beam frequency standards, by contrast, measure reference atomic transitions in a continuously replenished "flow through" configuration where initial ensemble atomic coherence is zero. We will describe some issues and problems that can arise when atomic state selection and preparation of the quantum atomic system is not completed, that is, optical pumping has not fully relaxed the coherence and also not fully transferred atoms to the initial state. We present a simple two-level density matrix analysis showing how frequency shifts during the state-selection process can cause frequency shifts of the measured clock transition. Such considerations are very important when a low intensity lamp light source is used for state selection, where there is relatively weak relaxation and re-pumping of ions to an initial state and much weaker 'environmental' relaxation of the atomic coherence set-up in the atomic sample.

  19. Interrogative Utterances in Surah Al-Baqarah

    Directory of Open Access Journals (Sweden)

    Aly Bayoumy AIi Oteify

    1993-11-01

    Full Text Available The Qur’an is singularly distinctive in its style compared to any human composition. Human eloquence, with its remarkable history in the composition of poetry, has failed to compose even a single verse like that of the Qur'an. The Qur'anic composition is a living challenge for human beings to imitate its miraculous style. This inimitable aspect of the Qur'an, among other things, proves that it was revealed by Allah (SWT to Prophet Muhammad (SAAS. In addition, the miracle of its linguistic composition was a means to declare the faith based on monotheism and the introduction of a new order and a theo-centric guidance that was meant to unite humanity. Adopting the monotheistic faith gave rise to a new community, the Muslim ummah that was able to bridge the differences between human beings in culture, race, colour and geographical boundaries. Consequently, the unique style of the Qur’an deserves a careful study. The present study investigates the use of interrogative utterances in surah al-Baqarah and their contribution to the Qur'an's rhetorical style. Hopefully, the results of this study will be useful in later investigations of other parts of the Qur' an...

  20. Blinding for unanticipated signatures

    NARCIS (Netherlands)

    D. Chaum (David)

    1987-01-01

    textabstractPreviously known blind signature systems require an amount of computation at least proportional to the number of signature types, and also that the number of such types be fixed in advance. These requirements are not practical in some applications. Here, a new blind signature technique

  1. Fair quantum blind signatures

    International Nuclear Information System (INIS)

    Tian-Yin, Wang; Qiao-Yan, Wen

    2010-01-01

    We present a new fair blind signature scheme based on the fundamental properties of quantum mechanics. In addition, we analyse the security of this scheme, and show that it is not possible to forge valid blind signatures. Moreover, comparisons between this scheme and public key blind signature schemes are also discussed. (general)

  2. Design Concept for the Microwave Interrogation Structure in PARCS

    National Research Council Canada - National Science Library

    Dick, G. J; Klipstein, W. M; Heavner, T. P; Jefferts, S. R

    2002-01-01

    In this paper we will describe key aspects of the conceptual design of the microwave interrogation structure in the laser-cooled cesium frequency standard that is part of the Primary Atomic Reference Clock in Space (PARCS) experiment...

  3. Lawfulness of Interrogation Techniques under the Geneva Conventions

    National Research Council Canada - National Science Library

    Elsea, Jennifer K

    2004-01-01

    Allegations of abuse of Iraqi prisoners by U.S. soldiers at the Abu Ghraib prison in Iraq have raised questions about the applicability of the law of war to interrogations for military intelligence purposes...

  4. Technology for Polymer Optical Fiber Bragg Grating Fabrication and Interrogation

    DEFF Research Database (Denmark)

    Ganziy, Denis

    The aim of this project is to develop a new, high-quality interrogator for FBG sensor systems, which combines high performance with costeffectiveness. The work includes the fields of optical system design, signal processing, and algorithm investigation. We present an efficient and fast peak...... analyze and investigate errors and drawbacks, which are typical for spectrometer-based interrogators: undersampling, grating internal reflection, photo response nonuniformity, pixel crosstalk and temperature and long term drift. We propose a novel type of multichannel Digital Micromirror Device (DMD......) based interrogator, where the linear detector is replaced with a commercially available DMD, which leads to cost reduction and better performance. Original optical design, which utilizes advantages of a retro-reflect optical scheme, has been developed in Zemax. We test the presented interrogator...

  5. The role of abusive states of being in interrogation.

    Science.gov (United States)

    Putnam, Frank W

    2013-01-01

    Interrogation, the questioning of persons detained by police, military, or intelligence organizations, is designed to extract information that a subject may resist disclosing. Interrogation techniques are frequently predicated on inducing mental states of despair, dread, dependency, and debility that weaken an individual's resistance. Descriptions of techniques from 2 Central Intelligence Agency training manuals are illustrated by examples from interviews of and writings by Murat Kurnaz, who was held at Guantánamo Bay Detention Camp for 5 years. Interrogation techniques are designed to create a destabilizing sense of shock; undermine an individual's grasp on reality; and provoke internal psychological division, self-conflict, and confusion. The long-term effects of interrogation often include posttraumatic stress disorder as well as states of anxiety, depression, and depersonalization.

  6. Long period grating based refractometer with polarization-sensitive interrogation

    International Nuclear Information System (INIS)

    Eftimov, T; Bock, W; Mikulic, P; Nikolova, K

    2010-01-01

    We propose a new scheme for the interrogation of long-period fiber gratings (LPGs) which makes use of their polarization properties. Polarization-sensitive interrogation was applied to detect changes due to changes of the external refractive index by using three wavelengths on the International Telecommunication Union (ITU) grid. We show that the new approach can allow for a greater sensitivity and can be used in combination with spectral multiplexing schemes

  7. Interrogation of an object for dimensional and topographical information

    Science.gov (United States)

    McMakin, Doug L [Richland, WA; Severtsen, Ronald H [Richland, WA; Hall, Thomas E [Richland, WA; Sheen, David M [Richland, WA

    2003-01-14

    Disclosed are systems, methods, devices, and apparatus to interrogate a clothed individual with electromagnetic radiation to determine one or more body measurements at least partially covered by the individual's clothing. The invention further includes techniques to interrogate an object with electromagnetic radiation in the millimeter and/or microwave range to provide a volumetric representation of the object. This representation can be used to display images and/or determine dimensional information concerning the object.

  8. Real Traceable Signatures

    Science.gov (United States)

    Chow, Sherman S. M.

    Traceable signature scheme extends a group signature scheme with an enhanced anonymity management mechanism. The group manager can compute a tracing trapdoor which enables anyone to test if a signature is signed by a given misbehaving user, while the only way to do so for group signatures requires revealing the signer of all signatures. Nevertheless, it is not tracing in a strict sense. For all existing schemes, T tracing agents need to recollect all N' signatures ever produced and perform RN' “checks” for R revoked users. This involves a high volume of transfer and computations. Increasing T increases the degree of parallelism for tracing but also the probability of “missing” some signatures in case some of the agents are dishonest.

  9. Interrogating resilience in health systems development.

    Science.gov (United States)

    van de Pas, Remco; Ashour, Majdi; Kapilashrami, Anuj; Fustukian, Suzanne

    2017-11-01

    The Fourth Global Symposium on Health Systems Research was themed around 'Resilient and responsive health systems for a changing world.' This commentary is the outcome of a panel discussion at the symposium in which the resilience discourse and its use in health systems development was critically interrogated. The 2014-15 Ebola outbreak in West-Africa added momentum for the wider adoption of resilient health systems as a crucial element to prepare for and effectively respond to crisis. The growing salience of resilience in development and health systems debates can be attributed in part to development actors and philanthropies such as the Rockefeller Foundation. Three concerns regarding the application of resilience to health systems development are discussed: (1) the resilience narrative overrules certain democratic procedures and priority setting in public health agendas by 'claiming' an exceptional policy space; (2) resilience compels accepting and maintaining the status quo and excludes alternative imaginations of just and equitable health systems including the socio-political struggles required to attain those; and (3) an empirical case study from Gaza makes the case that resilience and vulnerability are symbiotic with each other rather than providing a solution for developing a strong health system. In conclusion, if the normative aim of health policies is to build sustainable, universally accessible, health systems then resilience is not the answer. The current threats that health systems face demand us to imagine beyond and explore possibilities for global solidarity and justice in health. © The Author 2017. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. 29 CFR 18.614 - Calling and interrogation of witnesses by judge.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Calling and interrogation of witnesses by judge. 18.614... interrogation of witnesses by judge. (a) Calling by the judge. The judge may, on the judge's own motion or at... thus called. (b) Interrogation by the judge. The judge may interrogate witnesses, whether called by the...

  11. Base neutron noise in PWRs

    International Nuclear Information System (INIS)

    Kosaly, G.; Albrecht, R.W.; Dailey, D.J.; Fry, D.N.

    1981-01-01

    Considerable activity has been devoted in recent years to the use of neutron noise for investigation of problems in pressurized-water reactors (PWRs). The investigators have found that neutron noise provides an effective way to monitor reactor internal vibrations such as vertical and lateral core motion; core support barrel and thermal shield shell modes, bending modes of fuel assemblies, and control rod vibrations. However, noise analysts have also concluded that diagnosis of a problem is easier if baseline data for normal plant operation is available. Therefore, the authors have obtained ex-core neutron noise signatures from eight PWRs to determine the similarity of signatures between plants and to build a base of data to determine the sources of neutron noise and thus the potential diagnostic information contained in the data. It is concluded that: (1) ex-core neutron noise contains information about the vibration of components in the pressure vessel; (2) baseline signature acquisition can aid understanding of plant specific vibration frequencies and provide a bases for diagnosis of future problems if they occur; and (3) abnormal core support barrel vibration can most likely be detected over and above the plant-to-plant signature variation observed thus far

  12. Development of a Liquid Scintillator-Based Active Interrogation System for LEU Fuel Assemblies

    International Nuclear Information System (INIS)

    Lavietes, Anthony D.; Plenteda, Romano; Mascahrenas, Nicholas; Cronholm, L. Marie; Aspinall, Michael; Joyce, Malcolm; Tomanin, Alice; Peerani, Paolo

    2013-06-01

    The IAEA, in collaboration with the Joint Research Center (Ispra, IT) and Hybrid Instruments (Lancaster, UK), has developed a full scale, liquid scintillator-based active interrogation system to determine uranium (U) mass in fresh fuel assemblies. The system implements an array of moderate volume (∼1000 ml) liquid scintillator detectors, a multichannel pulse shape discrimination (PSD) system, and a high-speed data acquisition and signal processing system to assess the U content of fresh fuel assemblies. Extensive MCNPX-PoliMi modelling has been carried out to refine the system design and optimize the detector performance. These measurements, traditionally performed with 3 He-based assay systems (e.g., Uranium Neutron Coincidence Collar [UNCL], Active Well Coincidence Collar [AWCC]), can now be performed with higher precision in a fraction of the acquisition time. The system uses a high-flash point, non-hazardous scintillating fluid (EJ309) enabling their use in commercial nuclear facilities and achieves significantly enhanced performance and capabilities through the combination of extremely short gate times, adjustable energy detection threshold, real-time PSD electronics, and high-speed, FPGA-based data acquisition. Given the possible applications, this technology is also an excellent candidate for the replacement of select 3 He-based systems. Comparisons to existing 3 He-based active interrogation systems are presented where possible to provide a baseline performance reference. This paper will describe the laboratory experiments and associated modelling activities undertaken to develop and initially test the prototype detection system. (authors)

  13. Polarized neutrons

    International Nuclear Information System (INIS)

    Williams, W.G.

    1988-01-01

    The book on 'polarized neutrons' is intended to inform researchers in condensed matter physics and chemistry of the diversity of scientific problems that can be investigated using polarized neutron beams. The contents include chapters on:- neutron polarizers and instrumentation, polarized neutron scattering, neutron polarization analysis experiments and precessing neutron polarization. (U.K.)

  14. Neutron--neutron logging

    International Nuclear Information System (INIS)

    Allen, L.S.

    1977-01-01

    A borehole logging tool includes a steady-state source of fast neutrons, two epithermal neutron detectors, and two thermal neutron detectors. A count rate meter is connected to each neutron detector. A first ratio detector provides an indication of the porosity of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two epithermal neutron detectors. A second ratio detector provides an indication of both porosity and macroscopic absorption cross section of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two thermal neutron detectors. By comparing the signals of the two ratio detectors, oil bearing zones and salt water bearing zones within the formation being logged can be distinguished and the amount of oil saturation can be determined. 6 claims, 2 figures

  15. Unconditionally Secure Quantum Signatures

    Directory of Open Access Journals (Sweden)

    Ryan Amiri

    2015-08-01

    Full Text Available Signature schemes, proposed in 1976 by Diffie and Hellman, have become ubiquitous across modern communications. They allow for the exchange of messages from one sender to multiple recipients, with the guarantees that messages cannot be forged or tampered with and that messages also can be forwarded from one recipient to another without compromising their validity. Signatures are different from, but no less important than encryption, which ensures the privacy of a message. Commonly used signature protocols—signatures based on the Rivest–Adleman–Shamir (RSA algorithm, the digital signature algorithm (DSA, and the elliptic curve digital signature algorithm (ECDSA—are only computationally secure, similar to public key encryption methods. In fact, since these rely on the difficulty of finding discrete logarithms or factoring large primes, it is known that they will become completely insecure with the emergence of quantum computers. We may therefore see a shift towards signature protocols that will remain secure even in a post-quantum world. Ideally, such schemes would provide unconditional or information-theoretic security. In this paper, we aim to provide an accessible and comprehensive review of existing unconditionally securesecure signature schemes for signing classical messages, with a focus on unconditionally secure quantum signature schemes.

  16. Radar Signature Calculation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The calculation, analysis, and visualization of the spatially extended radar signatures of complex objects such as ships in a sea multipath environment and...

  17. Calculated NWIS signatures for enriched uranium metal

    International Nuclear Information System (INIS)

    Valentine, T.E.; Mihalczo, J.T.; Koehler, P.E.

    1995-01-01

    Nuclear Weapons Identification System (NWIS) signatures have been calculated using a Monte Carlo transport code for measurement configurations of a 252 Cf source, detectors, and a uranium metal casting. NWIS signatures consist of a wide variety of time-and frequency-analysis signatures such as the time distribution of neutrons after californium fission, the time distribution of counts in a detector after a previous count, the number of times n pulses occur in a time interval, and various frequency-analysis signatures, such as auto-power and cross-power spectral densities, coherences, and a ratio of spectral densities. This ratio is independent of detection efficiency. The analysis presented here, using the MCNP-DSP code, evaluates the applicability of this method for measurement of the 235 U content of 19-kg castings of depleted uranium and uranium with enrichments of 20, 40, 60, 80, 90, and 93.2 wt % 235 U. The dependence of the wide variety of NWIS signatures on 235 U content and possible configurations of a measurement system are presented. These preliminary calculations indicate short measurement times. Additional calculations are being performed to optimize the source-detector-moderator-casting configuration for the shortest measurement time. Although the NWIS method was developed for nuclear weapons identification, the development of a small processor now allows it to be also applied in a practical way to subcriticality measurements, nuclear fuel process monitoring and qualitative nondestructive assay of special nuclear material

  18. Improved fission neutron energy discrimination with {sup 4}He detectors through pulse filtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Ting, E-mail: ting.zhu@ufl.edu [University of Florida, Gainesville, FL (United States); Liang, Yinong; Rolison, Lucas; Barker, Cathleen; Lewis, Jason; Gokhale, Sasmit [University of Florida, Gainesville, FL (United States); Chandra, Rico [Arktis Radiation Detectors Ltd., Räffelstrasse 11, Zürich (Switzerland); Kiff, Scott [Sandia National Laboratories, CA (United States); Chung, Heejun [Korean Institute for Nuclear Nonproliferation and Control, 1534 Yuseong-daero, Yuseong-gu, Daejeon (Korea, Republic of); Ray, Heather; Baciak, James E.; Enqvist, Andreas; Jordan, Kelly A. [University of Florida, Gainesville, FL (United States)

    2017-03-11

    This paper presents experimental and computational techniques implemented for {sup 4}He gas scintillation detectors for induced fission neutron detection. Fission neutrons are produced when natural uranium samples are actively interrogated by 2.45 MeV deuterium-deuterium fusion reaction neutrons. Fission neutrons of energies greater than 2.45 MeV can be distinguished by their different scintillation pulse height spectra since {sup 4}He detectors retain incident fast neutron energy information. To enable the preferential detection of fast neutrons up to 10 MeV and suppress low-energy event counts, the detector photomultiplier gain is lowered and trigger threshold is increased. Pile-up and other unreliable events due to the interrogating neutron flux and background radiation are filtered out prior to the evaluation of pulse height spectra. With these problem-specific calibrations and data processing, the {sup 4}He detector's accuracy at discriminating fission neutrons up to 10 MeV is improved and verified with {sup 252}Cf spontaneous fission neutrons. Given the {sup 4}He detector's ability to differentiate fast neutron sources, this proof-of-concept active-interrogation measurement demonstrates the potential of special nuclear materials detection using a {sup 4}He fast neutron detection system.

  19. Innocence and resisting confession during interrogation: effects on physiologic activity.

    Science.gov (United States)

    Guyll, Max; Madon, Stephanie; Yang, Yueran; Lannin, Daniel G; Scherr, Kyle; Greathouse, Sarah

    2013-10-01

    Innocent suspects may not adequately protect themselves during interrogation because they fail to fully appreciate the danger of the situation. This experiment tested whether innocent suspects experience less stress during interrogation than guilty suspects, and whether refusing to confess expends physiologic resources. After experimentally manipulating innocence and guilt, 132 participants were accused and interrogated for misconduct, and then pressured to confess. Systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), respiratory sinus arrhythmia (RSA), and preejection period (PEP) responses quantified stress reactions. As hypothesized, the innocent evidenced smaller stress responses to interrogation for SBP, DBP, HR, and RSA than did the guilty. Furthermore, innocents who refused to confess exhibited greater sympathetic nervous system activation, as evidenced by shorter PEPs, than did innocent or guilty confessors. These findings suggest that innocent suspects underestimate the threat of interrogation and that resisting pressures to confess can diminish suspects' physiologic resources and lead to false confessions. PsycINFO Database Record (c) 2013 APA, all rights reserved

  20. A novel method for active fissile mass estimation with a pulsed neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Dubi, C., E-mail: chendb331@gmail.com [Physics Department, Nuclear Research Center of the Negev, POB 9001, Beer Sheva (Israel); Ridnik, T.; Israelashvili, I. [Physics Department, Nuclear Research Center of the Negev, POB 9001, Beer Sheva (Israel); Pedersen, B. [Nuclear Security Unit, Institute for Transuranium Elements, Via E. Fermi, 2749 JRC, Ispra (Italy)

    2013-07-01

    Neutron interrogation facilities for mass evaluation of Special Nuclear Materials (SNM) samples are divided into two main categories: passive interrogation, where all neutron detections are due to spontaneous events, and active interrogation, where fissions are induced on the tested material by an external neutron source. While active methods are, in general, faster and more effective, their analysis is much harder to carry out. In the paper, we will introduce a new formalism for analyzing the detection signal generated by a pulsed source active interrogation facility. The analysis is aimed to distinct between fission neutrons from the main neutron source in the system, and the surrounding “neutron noise”. In particular, we derive analytic expressions for the first three central moments of the number of detections in a given time interval, in terms of the different neutron sources. While the method depends on exactly the same physical assumptions as known models, the simplicity of the suggested formalism allows us to take into account the variance of the external neutron source—an effect that was so far neglected.

  1. A novel method for active fissile mass estimation with a pulsed neutron source

    International Nuclear Information System (INIS)

    Dubi, C.; Ridnik, T.; Israelashvili, I.; Pedersen, B.

    2013-01-01

    Neutron interrogation facilities for mass evaluation of Special Nuclear Materials (SNM) samples are divided into two main categories: passive interrogation, where all neutron detections are due to spontaneous events, and active interrogation, where fissions are induced on the tested material by an external neutron source. While active methods are, in general, faster and more effective, their analysis is much harder to carry out. In the paper, we will introduce a new formalism for analyzing the detection signal generated by a pulsed source active interrogation facility. The analysis is aimed to distinct between fission neutrons from the main neutron source in the system, and the surrounding “neutron noise”. In particular, we derive analytic expressions for the first three central moments of the number of detections in a given time interval, in terms of the different neutron sources. While the method depends on exactly the same physical assumptions as known models, the simplicity of the suggested formalism allows us to take into account the variance of the external neutron source—an effect that was so far neglected

  2. Signature scheme for the microscopic description of nuclear collective excitations

    International Nuclear Information System (INIS)

    Ogawa, K.

    1980-04-01

    The symmetries between the proton and neutron systems in a nucleus are described in terms of the signatures. Three kinds of signatures (i.e. the pn-, p anti n- and p anti p- (or n anti n-) signatures) are introduced and they are related to the appearance of various collective motions such as rotations or vibrations. It is shown that the pn-signature scheme provides a band-like structure of deformed nuclei, while the features associated with the quadrupole vibration are obtained in the p anti n- and p anti p-signature scheme. From the detail investigation of the p anti n-symmetric wave functions, it is concluded that the reguralities provided by the present shell model are more analogous to those of the γ-unstable surface vibration model (Wilets-Jean model) than to those of harmonic phonon model. (author)

  3. Development of fiber optic sensing interrogators for launchers

    Science.gov (United States)

    Plattner, M. P.; Buck, T. C.; Eder, B.; Reutlinger, A.; McKenzie, I.

    2017-11-01

    We present our work about the development of two complementary interrogation schemes based on fiber optic sensing for the use of structural and thermal monitoring of Ariane launchers. The advantages of fiber optic sensing in particular light-weight, immunity to electromagnetic interferences and the possibility of sensor distribution along optical fibers are driving factors for utilization of this technology in space crafts [1]. The edge-filter (EF) and scanning-laser (SL) interrogators for determination of the mean wavelength of fiber Bragg grating (FBG) sensors have been implemented as two separate demonstrators. Within this paper we describe the functional principles of both interrogators. Furthermore we present test results where the developed systems have been used for readout of FBG sensors which are implemented in an Ariane structural demonstrator during thermal, thermal-vacuum and vibration tests. Functionality of both systems is demonstrated and their potential for further development towards space qualified systems is shown. Since the performance characteristics of the two systems are different from each other, they are dedicated for different sensing applications on a launcher. The EF sensor interrogator provides a sample rate of 20 kHz at a number of 4 connected sensors and supports parallel readout and aliasing free operation. Therefore it is best suited for high priority measurement. Structural monitoring which requires the acquisition of real time sensor information in order to support control of the launcher is one operation area for a future EF system. The SL interrogator provides an overall measurement rate of 1 kHz at a number of 24 connected sensors distributed on three sensor channels. It can be adapted to any sensors that have design wavelengths lying within the output spectrum of the laser diode. Furthermore the number of overall sensors to be read out with this system can be adapted easily. Thermal mapping of satellite panels is one possible

  4. Ultracold neutrons

    International Nuclear Information System (INIS)

    Steenstrup, S.

    Briefly surveys recent developments in research work with ultracold neutrons (neutrons of very low velocity, up to 10 m/s at up to 10 -7 eV and 10 -3 K). Slow neutrons can be detected in an ionisation chamber filled with B 10 F 3 . Very slow neutrons can be used for investigations into the dipole moment of neutrons. Neutrons of large wave length have properties similar to those of light. The limit angle for total reflection is governed by the wave length and by the material. Total reflection can be used to filter ultracold neutrons out of the moderator material of a reactor. Total reflection can also be used to store ultracold neutrons but certain problems with storage have not yet been clarified. Slow neutrons can be made to lose speed in a neutron turbine, and come out as ultracold neutrons. A beam of ultracold neutrons could be used in a neutron microscope. (J.S.)

  5. A semi-classical approach to signature splitting and signature inversion in odd–odd nuclei

    International Nuclear Information System (INIS)

    Kumar, Vinod; Kumar, Suresh; Kumar, Sushil; Hasan, Zafrul; Koranga, B.S.; Kumar, Deepak; Negi, D.; Angus, Lee

    2011-01-01

    The signature inversion observed in rotational bands belonging to high-j configurations of odd–odd deformed nuclei has been analyzed within the framework of an axially symmetric rotor plus two-particle model. The Coriolis and n–p interaction are considered the main cause of energy staggering. However, γ-triaxial deformation and the numbers of valence protons, N p , and neutrons, N n also contribute to the energy staggering between odd- and even-spin states. (author)

  6. Interrogative suggestibility, confabulation, and acquiescence in people with mild learning disabilities (mental handicap): implications for reliability during police interrogations.

    Science.gov (United States)

    Clare, I C; Gudjonsson, G H

    1993-09-01

    In order to assess a criminal suspect's ability to make a reliable statement, performance on three measures--interrogative suggestibility, confabulation and acquiescence--may be used. This paper presents preliminary data on these measures for people with mild learning disabilities (Full Scale IQ [FSIQ]: 57-75). It was found that they were more suggestible than their average ability counterparts (FSIQ: 83-111) because they were much more susceptible to 'leading questions'. They also confabulated more and were more acquiescent. Overall, the data emphasized their potential vulnerability to giving erroneous testimony during interrogations.

  7. Signatures of Extended Storage of Used Nuclear Fuel in Casks

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-28

    As the amount of used nuclear fuel continues to grow, more and more used nuclear fuel will be transferred to storage casks. A consolidated storage facility is currently in the planning stages for storing these casks, where at least 10,000 MTHM of fuel will be stored. This site will have potentially thousands of casks once it is operational. A facility this large presents new safeguards and nuclear material accounting concerns. A new signature based on the distribution of neutron sources and multiplication within casks was part of the Department of Energy Office of Nuclear Energy’s Material Protection, Account and Control Technologies (MPACT) campaign. Under this project we looked at fingerprinting each cask's neutron signature. Each cask has a unique set of fuel, with a unique spread of initial enrichment, burnup, cooling time, and power history. The unique set of fuel creates a unique signature of neutron intensity based on the arrangement of the assemblies. The unique arrangement of neutron sources and multiplication produces a reliable and unique identification of the cask that has been shown to be relatively constant over long time periods. The work presented here could be used to restore from a loss of continuity of knowledge at the storage site. This presentation will show the steps used to simulate and form this signature from the start of the effort through its conclusion in September 2016.

  8. Threshold Signature Schemes Application

    Directory of Open Access Journals (Sweden)

    Anastasiya Victorovna Beresneva

    2015-10-01

    Full Text Available This work is devoted to an investigation of threshold signature schemes. The systematization of the threshold signature schemes was done, cryptographic constructions based on interpolation Lagrange polynomial, elliptic curves and bilinear pairings were examined. Different methods of generation and verification of threshold signatures were explored, the availability of practical usage of threshold schemes in mobile agents, Internet banking and e-currency was shown. The topics of further investigation were given and it could reduce a level of counterfeit electronic documents signed by a group of users.

  9. Interrogating Your Wisdom of Practice to Improve Classroom Practices

    Science.gov (United States)

    Chappell, Philip

    2017-01-01

    This article presents a heuristic for language teachers to articulate and explore their fundamental theories of and philosophical stances towards language, language learning, and language teaching. It includes tools with which teachers can interrogate those theories, weighing them up against their actual classroom practices. Through presenting…

  10. Learning about Posterior Probability: Do Diagrams and Elaborative Interrogation Help?

    Science.gov (United States)

    Clinton, Virginia; Alibali, Martha W.; Nathan, Mitchell J.

    2016-01-01

    To learn from a text, students must make meaningful connections among related ideas in that text. This study examined the effectiveness of two methods of improving connections--elaborative interrogation and diagrams--in written lessons about posterior probability. Undergraduate students (N = 198) read a lesson in one of three questioning…

  11. Postmortem ICD interrogation in mode of death classification.

    Science.gov (United States)

    Nikolaidou, Theodora; Johnson, Miriam J; Ghosh, Justin M; Marincowitz, Carl; Shah, Saumil; Lammiman, Michael J; Schilling, Richard J; Clark, Andrew L

    2018-04-01

    The definition of sudden death due to arrhythmia relies on the time interval between onset of symptoms and death. However, not all sudden deaths are due to arrhythmia. In patients with an implantable cardioverter defibrillator (ICD), postmortem device interrogation may help better distinguish the mode of death compared to a time-based definition alone. This study aims to assess the proportion of "sudden" cardiac deaths in patients with an ICD that have confirmed arrhythmia. We conducted a literature search for studies using postmortem ICD interrogation and a time-based classification of the mode of death. A modified QUADAS-2 checklist was used to assess risk of bias in individual studies. Outcome data were pooled where sufficient data were available. Our search identified 22 studies undertaken between 1982 and 2015 with 23,600 participants. The pooled results (excluding studies with high risk of bias) suggest that ventricular arrhythmias are present at the time of death in 76% of "sudden" deaths (95% confidence interval [CI] 67-85; range 42-88). Postmortem ICD interrogation identifies 24% of "sudden" deaths to be nonarrhythmic. Postmortem device interrogation should be considered in all cases of unexplained sudden cardiac death. © 2018 Wiley Periodicals, Inc.

  12. "Enhanced" interrogation of detainees: do psychologists and psychiatrists participate?

    Science.gov (United States)

    Halpern, Abraham L; Halpern, John H; Doherty, Sean B

    2008-09-25

    After revelations of participation by psychiatrists and psychologists in interrogation of prisoners at Guantánamo Bay and Central Intelligence Agency secret detention centers, the American Psychiatric Association and the American Psychological Association adopted Position Statements absolutely prohibiting their members from participating in torture under any and all circumstances, and, to a limited degree, forbidding involvement in interrogations. Some interrogations utilize very aggressive techniques determined to be torture by many nations and organizations throughout the world. This paper explains why psychiatrists and psychologists involved in coercive interrogations violate the Geneva Conventions and the laws of the United States. Whether done with ignorance of professional ethical obligations or not, these psychiatrists and psychologists have crossed an ethical barrier that may best be averted from re-occurring by teaching medical students and residents in all medical specialties about the ethics principles stemming from the 1946-1947 Nuremberg trials and the Geneva Conventions, together with the Ethics Codes of the World Medical Association and the American Medical Association; and, with regard to psychiatric residents and psychological trainees, by the teaching about The Principles of Medical Ethics With Annotations Especially Applicable to Psychiatry and the Ethical Principles of Psychologists and Code of Conduct, respectively. In this way, all physicians and psychologists will clearly understand that they have an absolute moral obligation to "First, do no harm" to the human beings they professionally encounter.

  13. "Enhanced" interrogation of detainees: do psychologists and psychiatrists participate?

    Directory of Open Access Journals (Sweden)

    Halpern John H

    2008-09-01

    Full Text Available Abstract After revelations of participation by psychiatrists and psychologists in interrogation of prisoners at Guantánamo Bay and Central Intelligence Agency secret detention centers, the American Psychiatric Association and the American Psychological Association adopted Position Statements absolutely prohibiting their members from participating in torture under any and all circumstances, and, to a limited degree, forbidding involvement in interrogations. Some interrogations utilize very aggressive techniques determined to be torture by many nations and organizations throughout the world. This paper explains why psychiatrists and psychologists involved in coercive interrogations violate the Geneva Conventions and the laws of the United States. Whether done with ignorance of professional ethical obligations or not, these psychiatrists and psychologists have crossed an ethical barrier that may best be averted from re-occurring by teaching medical students and residents in all medical specialties about the ethics principles stemming from the 1946–1947 Nuremberg trials and the Geneva Conventions, together with the Ethics Codes of the World Medical Association and the American Medical Association; and, with regard to psychiatric residents and psychological trainees, by the teaching about The Principles of Medical Ethics With Annotations Especially Applicable to Psychiatry and the Ethical Principles of Psychologists and Code of Conduct, respectively. In this way, all physicians and psychologists will clearly understand that they have an absolute moral obligation to "First, do no harm" to the human beings they professionally encounter.

  14. On the aesthetics of mimicry and proliferation: interrogations of ...

    African Journals Online (AJOL)

    This article examines innovative modes of interrogating spectacles of State power in postcolonial dictatorship novels. Authoritarian power in the postcolonial public sphere perpetuates itself through practices that reiterate the prerogatives of State reason, national progress, national unity and the indispensability of the ...

  15. Interrogating Infanticide/ Child Euthanasia in the Roman Christian ...

    African Journals Online (AJOL)

    The purpose of this paper is an attempt to examine infanticide practices in the Roman Christian era and interrogate infanticide and child euthanasia in the same era. It also attempts to point out infanticide practices in Abuja and makes a distinction between infanticide and child euthanasia in Abuja. The study employed ...

  16. Interrogating Public Sphere and Popular Culture as Theoretical ...

    African Journals Online (AJOL)

    Because of its theoretical roots in Western liberal thinking, scholars in African studies such as Comaroffs, Mamdani and Ekeh have vigorously debated the extent to which the concept of civil society is useful in explaining and interrogating developments in Africa. However, the concept of the public sphere has been subjected ...

  17. System to detect contraband in cargo containers using fast and slow neutron irradiation and collimated gamma detectors

    International Nuclear Information System (INIS)

    Smith, R.C.; Hurwitz, M.J.; Tran, K.C.

    1995-01-01

    We have produced a product design concept for an automatic, shipping-container inspection system to be used for detection of contraband, including illicit drugs, and for trade regulation enforcement via shipping manifest confirmation. Using nondestructive nuclear techniques the system can see deeply into the cargo and generate a 3-D spatial image of an entire container's contents automatically and in real time. A pulsed, sealed-tube, neutron generator is employed. The approach divides a container into numerous, small, volume elements that are individually interrogated using concurrent fast and slow neutron activation and gamma detection by collimated scintillators. We have designed, built, and operated a laboratory apparatus which has demonstrated the attractiveness of this approach. Experimental data were found to agree with design expectations derived from computer modeling. By combining selected element signatures and phenomenological measures, together with discrimination algorithms, we have demonstrated that a full-scale inspection system would need from less than 5 min to 30 min (depending on cargo type) to process an 8 ftx8 ftx40 ft container in order to detect hidden contraband. (orig.)

  18. Methods and systems using encapsulated tracers and chemicals for reservoir interrogation and manipulation

    Science.gov (United States)

    Roberts, Jeffery; Aines, Roger D; Duoss, Eric B; Spadaccini, Christopher M

    2014-11-04

    An apparatus, method, and system of reservoir interrogation. A tracer is encapsulating in a receptacle. The receptacle containing the tracer is injected into the reservoir. The tracer is analyzed for reservoir interrogation.

  19. Advanced Missile Signature Center

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Missile Signature Center (AMSC) is a national facility supporting the Missile Defense Agency (MDA) and other DoD programs and customers with analysis,...

  20. THE ELECTRONIC SIGNATURE

    Directory of Open Access Journals (Sweden)

    Voiculescu Madalina Irena

    2009-05-01

    Full Text Available Article refers to significance and the digital signature in electronic commerce. Internet and electronic commerce open up many new opportunities for the consumer, yet, the security (or perceived lack of security of exchanging personal and financial data

  1. Digital signature feasibility study

    Science.gov (United States)

    2008-06-01

    The purpose of this study was to assess the advantages and disadvantages of using digital signatures to assist the Arizona Department of Transportation in conducting business. The Department is evaluating the potential of performing more electronic t...

  2. Physics Signatures at CLIC

    CERN Document Server

    Battaglia, Marco

    2001-01-01

    A set of signatures for physics processes of potential interests for the CLIC programme at = 1 - 5 TeV are discussed. These signatures, that may correspond to the manifestation of different scenarios of new physics as well as to Standard Model precision tests, are proposed as benchmarks for the optimisation of the CLIC accelerator parameters and for a first definition of the required detector response.

  3. A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Material and High Explosives

    International Nuclear Information System (INIS)

    Seabury, E. H.; Chichester, D. L.; Wharton, C. J.; Caffrey, A. J.

    2009-01-01

    Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory's PINS Chemical Assay System has traditionally used a 252 Cf isotopic neutron source, but recently a deuterium-tritium (DT) electronic neutron generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM) and high explosive (HE) filled munitions.

  4. Active neutron and gamma-ray imaging of highly enriched uranium for treaty verification.

    Science.gov (United States)

    Hamel, Michael C; Polack, J Kyle; Ruch, Marc L; Marcath, Matthew J; Clarke, Shaun D; Pozzi, Sara A

    2017-08-11

    The detection and characterization of highly enriched uranium (HEU) presents a large challenge in the non-proliferation field. HEU has a low neutron emission rate and most gamma rays are low energy and easily shielded. To address this challenge, an instrument known as the dual-particle imager (DPI) was used with a portable deuterium-tritium (DT) neutron generator to detect neutrons and gamma rays from induced fission in HEU. We evaluated system response using a 13.7-kg HEU sphere in several configurations with no moderation, high-density polyethylene (HDPE) moderation, and tungsten moderation. A hollow tungsten sphere was interrogated to evaluate the response to a possible hoax item. First, localization capabilities were demonstrated by reconstructing neutron and gamma-ray images. Once localized, additional properties such as fast neutron energy spectra and time-dependent neutron count rates were attributed to the items. For the interrogated configurations containing HEU, the reconstructed neutron spectra resembled Watt spectra, which gave confidence that the interrogated items were undergoing induced fission. The time-dependent neutron count rate was also compared for each configuration and shown to be dependent on the neutron multiplication of the item. This result showed that the DPI is a viable tool for localizing and confirming fissile mass and multiplication.

  5. Directed Neutron Beams From Inverse Kinematic Reactions

    Science.gov (United States)

    Vanhoy, J. R.; Guardala, N. A.; Glass, G. A.

    2011-06-01

    Kinematic focusing of an emitted fairly mono-energetic neutron beam by the use of inverse-kinematic reactions, i.e. where the projectile mass is greater than the target atom's mass, can provide for the utilization of a significant fraction of the fast neutron yield and also provide for a safer radiation environment. We examine the merit of various neutron production reactions and consider the practicalities of producing the primary beam using the suitable accelerator technologies. Preliminary progress at the NSWC-Carderock Positive Ion Accelerator Facility is described. Possible important applications for this type of neutron-based system can be both advanced medical imaging techniques and active "stand-off" interrogation of contraband items.

  6. Used Fuel Cask Identification through Neutron Profile

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-20

    Currently, most spent fuel is stored near reactors. An interim consolidated fuel storage facility would receive fuel from multiple sites and store it in casks on site for decades. For successful operation of such a facility there is need for a way to restore continuity of knowledge if lost as well as a method that will indicate state of fuel inside the cask. Used nuclear fuel is identifiable by its radiation emission, both gamma and neutron. Neutron emission from fission products, multiplication from remaining fissile material, and the unique distribution of both in each cask produce a unique neutron signature. If two signatures taken at different times do not match, either changes within the fuel content or misidentification of a cask occurred. It was found that identification of cask loadings works well through the profile of emitted neutrons in simulated real casks. Even casks with similar overall neutron emission or average counts around the circumference can be distinguished from each other by analyzing the profile. In conclusion, (1) identification of unaltered casks through neutron signature profile is viable; (2) collecting the profile provides insight to the condition and intactness of the fuel stored inside the cask; and (3) the signature profile is stable over time.

  7. 25 CFR 11.303 - Notification of rights prior to custodial interrogation.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Notification of rights prior to custodial interrogation. 11.303 Section 11.303 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER... to custodial interrogation. Prior to custodial interrogation, the suspect shall be advised of the...

  8. 75 FR 67632 - Defense Federal Acquisition Regulation Supplement; Prohibition on Interrogation of Detainees by...

    Science.gov (United States)

    2010-11-03

    ...-AG88 Defense Federal Acquisition Regulation Supplement; Prohibition on Interrogation of Detainees by... National Defense Authorization Act for Fiscal Year 2010 (Pub. L. 111-84) prohibits the interrogation of..., to add DFARS 237.173, Prohibition on Interrogation of Detainees by Contractor Personnel, adding a...

  9. 29 CFR 18.611 - Mode and order of interrogation and presentation.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Mode and order of interrogation and presentation. 18.611... of interrogation and presentation. (a) Control by judge. The judge shall exercise reasonable control... interrogation and presentation effective for the ascertainment of the truth, (2) Avoid needless consumption of...

  10. From third degree to third generation interrogation strategies: putting science into the art of criminal interviewing

    Science.gov (United States)

    2017-03-01

    tacitly suggest that a confession is the fastest and best way to end the interrogation .73 71 Ibid...Kelly, and Miller found approximately 45 percent of civilian interrogators use it as well.292 Because this percentage suggests the technique is...TO THIRD-GENERATION INTERROGATION STRATEGIES: PUTTING SCIENCE INTO THE ART OF CRIMINAL INTERVIEWING by Desmond S. O’Neill March 2017

  11. Improving Reasoning and Recall: The Differential Effects of Elaborative Interrogation and Mnemonic Elaboration.

    Science.gov (United States)

    Scruggs, Thomas E.; And Others

    1993-01-01

    Fifty-three adolescents with learning disabilities or mild mental retardation were taught reasons for dinosaur extinction. Those taught in a mnemonic elaborative interrogation condition recalled more reasons than did students who received direct teaching. Students in elaborative interrogation and mnemonic elaborative interrogation groups recalled…

  12. Neutron reflectometry

    International Nuclear Information System (INIS)

    Van Well, A.A.

    1999-01-01

    Neutron research where reflection, refraction, and interference play an essential role is generally referred to as 'neutron optics'. The neutron wavelength, the scattering length density and the magnetic properties of the material determine the critical angle for total reflection. The theoretical background of neutron reflection, experimental methods and the interpretation of reflection data are presented. (K.A.)

  13. Experimental signatures of gravitational wave bursters

    International Nuclear Information System (INIS)

    Dubath, Florian; Foffa, Stefano; Gasparini, Maria Alice; Maggiore, Michele; Sturani, Riccardo

    2005-01-01

    Gravitational wave bursters are sources which emit repeatedly bursts of gravitational waves, and have been recently suggested as potentially interesting candidates for gravitational wave (GW) detectors. Mechanisms that could give rise to a GW burster can be found for instance in highly magnetized neutron stars (the 'magnetars' which explain the phenomenon of soft gamma repeaters), in accreting neutron stars and in hybrid stars with a quark core. We point out that these sources have very distinctive experimental signatures. In particular, as already observed in the γ-ray bursts from soft gamma repeaters, the energy spectrum of the events is a power-law, dN∼E -γ dE with γ≅1.6, and they have a distribution of waiting times (the times between one outburst and the next) significantly different from the distribution of uncorrelated events. We discuss possible detection strategies that could be used to search for these events in existing gravitational wave detectors

  14. The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. IV. Detection of Near-infrared Signatures of r -process Nucleosynthesis with Gemini-South

    Energy Technology Data Exchange (ETDEWEB)

    Chornock, R. [Astrophysical Institute, Department of Physics and Astronomy, 251B Clippinger Lab, Ohio University, Athens, OH 45701 (United States); Berger, E.; Cowperthwaite, P. S.; Nicholl, M.; Villar, V. A.; Alexander, K. D.; Blanchard, P. K.; Eftekhari, T.; Williams, P. K. G. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kasen, D. [Departments of Physics and Astronomy, and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720-7300 (United States); Fong, W.; Margutti, R. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Annis, J.; Frieman, J. A. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Brout, D. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Brown, D. A. [Department of Physics, Syracuse University, Syracuse NY 13224 (United States); Chen, H.-Y. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Drout, M. R. [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Farr, B. [Department of Physics, University of Oregon, Eugene, OR 97403 (United States); Foley, R. J., E-mail: chornock@ohio.edu [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); and others

    2017-10-20

    We present a near-infrared spectral sequence of the electromagnetic counterpart to the binary neutron star merger GW170817 detected by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo. Our data set comprises seven epochs of J + H spectra taken with FLAMINGOS-2 on Gemini-South between 1.5 and 10.5 days after the merger. In the initial epoch, the spectrum is dominated by a smooth blue continuum due to a high-velocity, lanthanide-poor blue kilonova component. Starting the following night, all of the subsequent spectra instead show features that are similar to those predicted in model spectra of material with a high concentration of lanthanides, including spectral peaks near 1.07 and 1.55 μ m. Our fiducial model with 0.04 M {sub ⊙} of ejecta, an ejection velocity of v = 0.1 c , and a lanthanide concentration of X {sub lan} = 10{sup −2} provides a good match to the spectra taken in the first five days, although it over-predicts the late-time fluxes. We also explore models with multiple fitting components, in each case finding that a significant abundance of lanthanide elements is necessary to match the broad spectral peaks that we observe starting at 2.5 days after the merger. These data provide direct evidence that binary neutron star mergers are significant production sites of even the heaviest r -process elements.

  15. Neutron radiography with ultracold neutrons

    International Nuclear Information System (INIS)

    Bates, J.C.

    1981-01-01

    The neutron transmission factor of very thin films may be low if the neutron energy is comparable to the pseudo-potential of the film material. Surprisingly, perhaps, it is relatively easy to obtain neutrons with such low energies in sufficient numbers to produce neutron radiographs. (orig.)

  16. Noncontact power/interrogation system for smart structures

    Science.gov (United States)

    Spillman, William B., Jr.; Durkee, S.

    1994-05-01

    The field of smart structures has been largely driven by the development of new high performance designed materials. Use of these materials has been generally limited due to the fact that they have not been in use long enough for statistical data bases to be developed on their failure modes. Real time health monitoring is therefore required for the benefits of structures using these materials to be realized. In this paper a non-contact method of powering and interrogating embedded electronic and opto-electronic systems is described. The technique utilizes inductive coupling between external and embedded coils etched on thin electronic circuit cards. The technique can be utilized to interrogate embedded sensors and to provide > 250 mW for embedded electronics. The system has been successfully demonstrated with a number of composite and plastic materials through material thicknesses up to 1 cm. An analytical description of the system is provided along with experimental results.

  17. The development of enabling technologies for producing active interrogation beams.

    Science.gov (United States)

    Kwan, Thomas J T; Morgado, Richard E; Wang, Tai-Sen F; Vodolaga, B; Terekhin, V; Onischenko, L M; Vorozhtsov, S B; Samsonov, E V; Vorozhtsov, A S; Alenitsky, Yu G; Perpelkin, E E; Glazov, A A; Novikov, D L; Parkhomchuk, V; Reva, V; Vostrikov, V; Mashinin, V A; Fedotov, S N; Minayev, S A

    2010-10-01

    A U.S./Russian collaboration of accelerator scientists was directed to the development of high averaged-current (∼1 mA) and high-quality (emittance ∼15 πmm mrad; energy spread ∼0.1%) 1.75 MeV proton beams to produce active interrogation beams that could be applied to counterterrorism. Several accelerator technologies were investigated. These included an electrostatic tandem accelerator of novel design, a compact cyclotron, and a storage ring with energy compensation and electron cooling. Production targets capable of withstanding the beam power levels were designed, fabricated, and tested. The cyclotron/storage-ring system was theoretically studied and computationally designed, and the electrostatic vacuum tandem accelerator at BINP was demonstrated for its potential in active interrogation of explosives and special nuclear materials.

  18. Fiber Bragg grating sensor interrogators on chip: challenges and opportunities

    Science.gov (United States)

    Marin, Yisbel; Nannipieri, Tiziano; Oton, Claudio J.; Di Pasquale, Fabrizio

    2017-04-01

    In this paper we present an overview of the current efforts towards integration of Fiber Bragg Grating (FBG) sensor interrogators. Different photonic integration platforms will be discussed, including monolithic planar lightwave circuit technology, silicon on insulator (SOI), indium phosphide (InP) and gallium arsenide (GaAs) material platforms. Also various possible techniques for wavelength metering and methods for FBG multiplexing will be discussed and compared in terms of resolution, dynamic performance, multiplexing capabilities and reliability. The use of linear filters, array waveguide gratings (AWG) as multiple linear filters and AWG based centroid signal processing techniques will be addressed as well as interrogation techniques based on tunable micro-ring resonators and Mach-Zehnder interferometers (MZI) for phase sensitive detection. The paper will also discuss the challenges and perspectives of photonic integration to address the increasing requirements of several industrial applications.

  19. Simulation and preliminary experimental results for an active neutron counter using a neutron generator for a fissile material accounting

    International Nuclear Information System (INIS)

    Ahn, Seong-Kyu; Lee, Tae-Hoon; Shin, Hee-Sung; Kim, Ho-Dong

    2009-01-01

    An active neutron coincidence counter using a neutron generator as an interrogation source has been suggested. Because of the high energy of the interrogation neutron source, 2.5 MeV, the induced fission rate is strongly affected by the moderator design. MCNPX simulation has been performed to evaluate the performance achieved with these moderators. The side- and bottom-moderator are significantly important to thermalize neutrons to induce fission. Based on the simulation results, the moderators are designed to be adapted to the experimental system. Their preliminary performance has been tested by using natural uranium oxide powder samples. For a sample of up to 3.5 kg, which contains 21.7 g of 235 U, 2.64 cps/g- 235 U coincidence events have been measured. Mean background error was 9.57 cps and the resultant coincidence error was 13.8 cps. The experimental result shows the current status of an active counting using a neutron generator which still has some challenges to overcome. However, the controllability of an interrogation source makes this system more applicable for a variety of combinations with other non-destructive methods like a passive coincidence counting especially under a harsh environment such as a hot cell. More precise experimental setup and tests with higher enriched samples will be followed to develop a system to apply it to an active measurement for the safeguards of a spent fuel treatment process.

  20. Interrogation of Detainees: Requirements of the Detainee Treatment Act

    Science.gov (United States)

    2009-08-26

    providing legal protections and assistance to U.S. personnel subjected to legal action on account of their involvement in the authorized interrogation of...types of actions prohibited by the U.S. Constitution. There is some legal dispute as to whether CAT Article 16, as read in light of U.S. reservations... unconstitutionally harsh than it would use to assess whether those same techniques were unconstitutional if employed against an enemy combatant in a war zone

  1. Educing Information - Interrogation: Science and Art, Foundations for the Future

    Science.gov (United States)

    2006-12-01

    imprisonment as an integral component of the inquisitor’s interrogation strategy…. [C]oupled if necessary, with hunger , shackles, and torture…[it...computer science with a concentration in machine intelligence and cognition, and minors in neuropsychology and developmental psychology, from The George...a solid theoretical base, then a signifi cant research investment into the underlying neuropsychological mechanisms of deception must be made before

  2. The synchronous active neutron detection assay system

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Kendall, P.K.

    1994-01-01

    We have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit a 14-MeV neutron generator developed by Schlumberger. The technique, termed synchronous active neutron detection (SAND), follows a method used routinely in other branches of physics to detect very small signals in presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ''lock-in'' amplifiers. We have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. Results are preliminary but promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly; it also appears resilient to background neutron interference. The interrogating neutrons appear to be non-thermal and penetrating. Work remains to fully explore relevant physics and optimize instrument design

  3. Uncertainty in hydrological signatures

    Science.gov (United States)

    McMillan, Hilary; Westerberg, Ida

    2015-04-01

    Information that summarises the hydrological behaviour or flow regime of a catchment is essential for comparing responses of different catchments to understand catchment organisation and similarity, and for many other modelling and water-management applications. Such information types derived as an index value from observed data are known as hydrological signatures, and can include descriptors of high flows (e.g. mean annual flood), low flows (e.g. mean annual low flow, recession shape), the flow variability, flow duration curve, and runoff ratio. Because the hydrological signatures are calculated from observed data such as rainfall and flow records, they are affected by uncertainty in those data. Subjective choices in the method used to calculate the signatures create a further source of uncertainty. Uncertainties in the signatures may affect our ability to compare different locations, to detect changes, or to compare future water resource management scenarios. The aim of this study was to contribute to the hydrological community's awareness and knowledge of data uncertainty in hydrological signatures, including typical sources, magnitude and methods for its assessment. We proposed a generally applicable method to calculate these uncertainties based on Monte Carlo sampling and demonstrated it for a variety of commonly used signatures. The study was made for two data rich catchments, the 50 km2 Mahurangi catchment in New Zealand and the 135 km2 Brue catchment in the UK. For rainfall data the uncertainty sources included point measurement uncertainty, the number of gauges used in calculation of the catchment spatial average, and uncertainties relating to lack of quality control. For flow data the uncertainty sources included uncertainties in stage/discharge measurement and in the approximation of the true stage-discharge relation by a rating curve. The resulting uncertainties were compared across the different signatures and catchments, to quantify uncertainty

  4. Practical quantum digital signature

    Science.gov (United States)

    Yin, Hua-Lei; Fu, Yao; Chen, Zeng-Bing

    2016-03-01

    Guaranteeing nonrepudiation, unforgeability as well as transferability of a signature is one of the most vital safeguards in today's e-commerce era. Based on fundamental laws of quantum physics, quantum digital signature (QDS) aims to provide information-theoretic security for this cryptographic task. However, up to date, the previously proposed QDS protocols are impractical due to various challenging problems and most importantly, the requirement of authenticated (secure) quantum channels between participants. Here, we present the first quantum digital signature protocol that removes the assumption of authenticated quantum channels while remaining secure against the collective attacks. Besides, our QDS protocol can be practically implemented over more than 100 km under current mature technology as used in quantum key distribution.

  5. Microwave Wire Interrogation Method Mapping Pressure under High Temperatures

    Directory of Open Access Journals (Sweden)

    Xiaoyong Chen

    2017-12-01

    Full Text Available It is widely accepted that wireless reading for in-situ mapping of pressure under high-temperature environments is the most feasible method, because it is not subject to frequent heterogeneous jointing failures and electrical conduction deteriorating, or even disappearing, under heat load. However, in this article, we successfully demonstrate an in-situ pressure sensor with wire interrogation for high-temperature applications. In this proof-of-concept study of the pressure sensor, we used a microwave resonator as a pressure-sensing component and a microwave transmission line as a pressure characteristic interrogation tunnel. In the sensor, the line and resonator are processed into a monolith, avoiding a heterogeneous jointing failure; further, microwave signal transmission does not depend on electrical conduction, and consequently, the sensor does not suffer from the heat load. We achieve pressure monitoring under 400 °C when employing the sensor simultaneously. Our sensor avoids restrictions that exist in wireless pressure interrogations, such as environmental noise and interference, signal leakage and security, low transfer efficiency, and so on.

  6. On Functional Potential of Interrogative Structures in Academic Linguistic Discourse

    Directory of Open Access Journals (Sweden)

    Sergey Trofimovich Nefedov

    2015-11-01

    Full Text Available The paper deals with the language of scientific communication in the field of linguistics, namely, with the functional potential of the interrogative structures in the form of direct and embedded questions. From a pragmatic perspective the interrogative structures does not seem to be compatible with the contexts of scientific interaction: scientists do not ask for information, but they offer their own solutions for the problem situations. This is reflected in the extremely low frequency of questions in academic research articles and monographs. Their text frequency works out a little over 2 % of the total number of the text predications and that of direct questions is about 1 %. Therefore, their place in verbalization of scientific knowledge in linguistics is metaphorically characterized in this article as «interrogative prohibition» by analogy with the «prohibitions» of Harald Weinrich who introduced several notions point to rarely used linguistic units: «prohibition of authorization» – das «Ich-Verbot», «narrative prohibition» – das «Erzähl-Verbot»; «prohibition of metaphors»– das «MetaphernVerbot». In its turn, low frequency makes the analyzed structures an effective tool to formulate the discussed problems, enables further argumentation, integrate the current text into overall linguistic discourse, control the development of the argumentation in scientific text and finally to draw the recipient's attention to a crucial or unexpected argument.

  7. Neutron Skins and Neutron Stars

    OpenAIRE

    Piekarewicz, J.

    2013-01-01

    The neutron-skin thickness of heavy nuclei provides a fundamental link to the equation of state of neutron-rich matter, and hence to the properties of neutron stars. The Lead Radius Experiment ("PREX") at Jefferson Laboratory has recently provided the first model-independence evidence on the existence of a neutron-rich skin in 208Pb. In this contribution we examine how the increased accuracy in the determination of neutron skins expected from the commissioning of intense polarized electron be...

  8. Radiography with polarised neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael L.

    2010-08-20

    different ordering temperatures. This procedure was tested on one Pd{sub 1-x}Ni{sub x} sample and the results were compared with simulations of the temperature dependence of the neutron beam depolarisation by an inhomogeneous sample. As a result from these simulations a criterion was developed to assess the amount of heterogeneity in a sample from the shape of the temperature dependence of the beam polarisation after transmission of the sample. It is found from simulations that increasing the heterogeneity in the sample leads to a rounding of the signature of the phase transition in the depolarisation data. (orig.)

  9. Radiography with polarised neutrons

    International Nuclear Information System (INIS)

    Schulz, Michael L.

    2010-01-01

    procedure was tested on one Pd 1-x Ni x sample and the results were compared with simulations of the temperature dependence of the neutron beam depolarisation by an inhomogeneous sample. As a result from these simulations a criterion was developed to assess the amount of heterogeneity in a sample from the shape of the temperature dependence of the beam polarisation after transmission of the sample. It is found from simulations that increasing the heterogeneity in the sample leads to a rounding of the signature of the phase transition in the depolarisation data. (orig.)

  10. Recent advances in fast neutron radiography for cargo inspection

    International Nuclear Information System (INIS)

    Sowerby, B.D.; Tickner, J.R.

    2007-01-01

    Fast neutron radiography techniques are attractive for screening cargo for contraband such as narcotics and explosives. Neutrons have the required penetration, they interact with matter in a manner complementary to X-rays and they can be used to determine elemental composition. Compared to neutron interrogation techniques that measure secondary radiation (neutron or gamma-rays), neutron radiography systems are much more efficient and rapid and they are much more amenable to imaging. However, for neutron techniques to be successfully applied to cargo screening, they must demonstrate significant advantages over well-established X-ray techniques. This paper reviews recent developments and applications of fast neutron radiography for cargo inspection. These developments include a fast neutron and gamma-ray radiography system that utilizes a 14 MeV neutron generator as well as fast neutron resonance radiography systems that use variable energy quasi-monoenergetic neutrons and pulsed broad energy neutron beams. These systems will be discussed and compared with particular emphasis on user requirements, sources, detector systems, imaging ability and performance

  11. Neutron Dosimetry

    International Nuclear Information System (INIS)

    Vanhavere, F.

    2001-01-01

    The objective of SCK-CEN's R and D programme on neutron dosimetry is to improve the determination of neutron doses by studying neutron spectra, neutron dosemeters and shielding adaptations. In 2000, R and D focused on the contiued investigation of the bubble detectors type BD-PND and BDT, in particular their sensitivity and temperature dependence; the updating of SCK-CEN's criticality dosemeter, the investigation of the characteristics of new thermoluminescent materials and their use in neutron dosemetry; and the investigation of neutron shielding

  12. Neutron Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Vanhavere, F

    2001-04-01

    The objective of SCK-CEN's R and D programme on neutron dosimetry is to improve the determination of neutron doses by studying neutron spectra, neutron dosemeters and shielding adaptations. In 2000, R and D focused on the contiued investigation of the bubble detectors type BD-PND and BDT, in particular their sensitivity and temperature dependence; the updating of SCK-CEN's criticality dosemeter, the investigation of the characteristics of new thermoluminescent materials and their use in neutron dosemetry; and the investigation of neutron shielding.

  13. Signature inversion in doubly odd 124La

    International Nuclear Information System (INIS)

    Chantler, H.J.; Paul, E.S.; Boston, A.J.; Choy, P.T.W.; Nolan, P.J.; Carpenter, M.P.; Davids, C.N.; Seweryniak, D.; Charity, R.; Devlin, M.; Sarantites, D.G.; Chiara, C.J.; Fossan, D.B.; Koike, T.; LaFosse, D.R.; Starosta, K.; Fletcher, A.M.; Smith, J.F.; Jenkins, D.G.; Kelsall, N.S.

    2002-01-01

    High-spin states have been studied in neutron-deficient 57 124 La 67 , populated through the 64 Zn( 64 Zn,3pn) reaction at 260 MeV. The Gammasphere γ-ray spectrometer has been used in conjunction with the Microball charged-particle detector, the Neutron Shell, and the Argonne Fragment Mass Analyzer, in order to select evaporation residues of interest. The known band structures have been extended and new bands found. Most of the bands are linked together, allowing more consistent spin and parity assignments. Comparison of band properties to cranking calculations has allowed configuration assignments to be made and includes the first identification of the g 9/2 proton-hole in an odd-odd lanthanum isotope. Two bands have been assigned a πh 11/2 xνh 11/2 structure; the yrast one exhibits a signature inversion in its level energies below I=18.5(ℎ/2π), while the excited one exhibits a signature inversion above I=18.5(ℎ/2π)

  14. Signatures of the Invisible

    CERN Multimedia

    Strom, D

    2003-01-01

    On the Net it is possible to take a look at art from afar via Virtual Museums. One such exhibition was recently in the New York Museum of Modern Art's branch, PS1. Entitled 'Signatures of the Invisible' it was a collaborative effort between artists and physicists (1/2 page).

  15. Evolution of Neutron Stars and Observational Constraints

    Directory of Open Access Journals (Sweden)

    Lattimer J.

    2010-10-01

    Full Text Available The structure and evolution of neutron stars is discussed with a view towards constraining the properties of high density matter through observations. The structure of neutron stars is illuminated through the use of several analytical solutions of Einstein’s equations which, together with the maximally compact equation of state, establish extreme limits for neutron stars and approximations for binding energies, moments of inertia and crustal properties as a function of compactness. The role of the nuclear symmetry energy is highlighted and constraints from laboratory experiments such as nuclear masses and heavy ion collisions are presented. Observed neutron star masses and radius limits from several techniques, such as thermal emissions, X-ray bursts, gammaray flares, pulsar spins and glitches, spin-orbit coupling in binary pulsars, and neutron star cooling, are discussed. The lectures conclude with a discusson of proto-neutron stars and their neutrino signatures.

  16. Neutron radiography

    International Nuclear Information System (INIS)

    Hrdlicka, Z.

    1977-01-01

    Neutron radiography is a radiographic method using a neutron beam of a defined geometry. The neutron source usually consists of a research reactor, a specialized neutron radiography reactor or the 252 Cf radioisotope source. There are two types of the neutron radiography display system, viz., a system producing neutron radiography images by a photographic process or a system allowing a visual display, eg., using a television monitor. The method can be used wherever X-ray radiography is used except applications in the radiography of humans. The neutron radiography unit at UJV uses the WWR-S reactor as the neutron source and both types of the above mentioned display system. (J.P.)

  17. New Organic Scintillators for Neutron Detection

    Science.gov (United States)

    2016-03-01

    gamma rays. For heterogeneous or dense materials such as samples of metals , oxides , and nuclear waste, gamma ray attenuation can be too high to...highly enriched uranium and weapons grade plutonium. Neutrons and gamma rays are two signatures of these materials. Gamma ray detection techniques are... uranium ). Thus, neutron detection is an important component of the overall detection techniques used in identifying SNMs. Important requirements for

  18. Sealed operation of a rf driven ion source for a compact neutron generator to be used for associated particle imaging.

    Science.gov (United States)

    Wu, Y; Hurley, J P; Ji, Q; Kwan, J W; Leung, K N

    2010-02-01

    We present the recent development of a prototype compact neutron generator to be used in conjunction with the method of associated particle imaging for the purpose of active neutron interrogation. In this paper, the performance and device specifications of these compact generators that employ rf driven ion sources will be discussed. Initial measurements of the generator performance include a beam spot size of 1 mm in diameter and a neutron yield of 2x10(5) n/s with air cooling.

  19. The neutron

    International Nuclear Information System (INIS)

    Kredov, B.M.

    1979-01-01

    The history of the neutron is displayed on the basis of contributions by scientists who produced outstanding results in neutron research (part 1), of summarizing discoveries and theories which led to the discovery of the neutron and the resulting development of nuclear physics (part 2), and of fundamental papers written by Rutherford, Chadwick, Iwanenko, and others (appendix). Of interest to physicists, historians, and students

  20. Neutron techniques

    International Nuclear Information System (INIS)

    Charlton, J.S.

    1986-01-01

    The way in which neutrons interact with matter such as slowing-down, diffusion, neutron absorption and moderation are described. The use of neutron techniques in industry, in moisture gages, level and interface measurements, the detection of blockages, boron analysis in ore feedstock and industrial radiography are discussed. (author)

  1. High energy cosmic ray signature of quark nuggets

    Science.gov (United States)

    Audouze, J.; Schaeffer, R.; Silk, J.

    1985-01-01

    It has been recently proposed that dark matter in the Universe might consist of nuggets of quarks which populate the nuclear desert between nucleons and neutron star matter. It is further suggested that the Centauro events which could be the signature of particles with atomic mass A approx. 100 and energy E approx. 10 to 15th power eV might also be related to debris produced in the encounter of two neutron stars. A further consequence of the former proposal is examined, and it is shown that the production of relativistic quark nuggets is accompanied by a substantial flux of potentially observable high energy neutrinos.

  2. Metabolic interrogation as a tool to optimize chemotherapeutic regimens.

    Science.gov (United States)

    Sandulache, Vlad C; Chen, Yunyun; Feng, Lei; William, William N; Skinner, Heath D; Myers, Jeffrey N; Meyn, Raymond E; Li, Jinzhong; Mijiti, Ainiwaer; Bankson, James A; Fuller, Clifton D; Konopleva, Marina Y; Lai, Stephen Y

    2017-03-14

    Platinum-based (Pt) chemotherapy is broadly utilized in the treatment of cancer. Development of more effective, personalized treatment strategies require identification of novel biomarkers of treatment response. Since Pt compounds are inactivated through cellular metabolic activity, we hypothesized that metabolic interrogation can predict the effectiveness of Pt chemotherapy in a pre-clinical model of head and neck squamous cell carcinoma (HNSCC).We tested the effects of cisplatin (CDDP) and carboplatin (CBP) on DNA damage, activation of cellular death cascades and tumor cell metabolism, specifically lactate production. Pt compounds induced an acute dose-dependent, transient drop in lactate generation in vitro, which correlated with effects on DNA damage and cell death. Neutralization of free radical stress abrogated these effects. The magnitude of this effect on lactate production correlated with the differential sensitivity of HNSCC cells to Pt compounds (CDDP vs CBP) and p53-driven Pt chemotherapy resistance. Using dual flank xenograft tumors, we demonstrated that Pt-driven effects on lactate levels correlate with effects on tumor growth delay in a dose-dependent manner and that lactate levels can define the temporal profile of Pt chemotherapy-induced metabolic stress. Lactate interrogation also predicted doxorubicin effects on cell death in both solid tumor (HNSCC) and acute myelogenous leukemia (AML) cell lines.Real-time metabolic interrogation of acute changes in cell and tumor lactate levels reflects chemotherapy effects on DNA damage, cell death and tumor growth delay. We have identified a real-time biomarker of chemotherapy effectiveness which can be used to develop adaptive, iterative and personalized treatment regimens against a variety of solid and hematopoietic malignancies.

  3. Study of the neutron decays of giant resonances excited by the inelastic scattering of 36 Ar on 90 Zr and 94 Zr targets at 44 MeV/u: a signature of multiphonon states

    International Nuclear Information System (INIS)

    Pascalon-Rozier, V.

    1997-01-01

    In inelastic heavy ion scattering, to angles near to the grazing angle, giant resonances (GR) are excited with very large differential cross sections. It has been shown that multiphonon states, states built with several GR quanta, can also been excited. These states can be revealed through the measurement of their decay by light particle emission. In this thesis, we report on the study of inelastic scattering of 36 Ar at 44 MeV/u on target of 90 Zr and 94 Zr, measured in coincidence with neutrons detected with the EDEN multidetector. The analysis of the inelastic spectra show evidence for a structure at high excitation energy, exhibiting characteristics compatible with a two-photon excitation. The construction of missing energy spectra allows us to the study of the GR and the high energy structure. In both nuclei, the GR presents a direct decay branch of 8%, which yields informations on the microscopic structure of the resonance. A two phonon state, interpreted as two weakly coupled GR's, built on one top of the other, and each phonon is expected to exhibit the same direct decay pattern as the GR. Such a simple decay is observed in the data, proving that the structure observed is due to the excitation of the two phonon state in both nuclei studied. Finally, we present a theoretical development based on Random Phase Approximation calculation, predicting that the two phonon state should be very harmonic. This result is in agreement with experimental studies of double phonon states over a large range of nuclei (from A = 12 to 208) carried out with several different probes. (author)

  4. Neutron-based portable drug probe

    International Nuclear Information System (INIS)

    Womble, P. C.; Vourvopoulos, G.; Ball Howard, J.; Paschal, J.

    1999-01-01

    Based on previous measurements, a probe prototype for contraband detection utilizing the neutron technique of Pulsed Fast-Thermal Neutron Analysis (PFTNA) is being constructed. The prototype weighs less than 45 kg and is composed of a probe (5 cm diameter), a power pack and a data acquisition and display system. The probe is designed to be inserted in confined spaces such as the boiler of a ship or a tanker truck filled with liquid. The probe provides information on a) the elemental content, and b) the density variations of the interrogated object. By measuring elemental content, the probe can differentiate between innocuous materials and drugs. Density variations can be found through fast neutron transmission. In all cases, hidden drugs are identified through the measurement of the elemental content of the object, and the comparison of expected and measured elemental ratios

  5. Determination of total plutonium content in spent nuclear fuel assemblies with the differential die-away self-interrogation instrument

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Alexis C. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 500 S State St., Ann Arbor, MI 48109 (United States); Henzl, Vladimir; Menlove, Howard O.; Swinhoe, Martyn T.; Belian, Anthony P. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544 (United States); Flaska, Marek; Pozzi, Sara A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 500 S State St., Ann Arbor, MI 48109 (United States)

    2014-11-11

    As a part of the Next Generation Safeguards Initiative Spent Fuel project, we simulate the response of the Differential Die-away Self-Interrogation (DDSI) instrument to determine total elemental plutonium content in an assayed spent nuclear fuel assembly (SFA). We apply recently developed concepts that relate total plutonium mass with SFA multiplication and passive neutron count rate. In this work, the multiplication of the SFA is determined from the die-away time in the early time domain of the Rossi-Alpha distributions measured directly by the DDSI instrument. We utilize MCNP to test the method against 44 pressurized water reactor SFAs from a simulated spent fuel library with a wide dynamic range of characteristic parameters such as initial enrichment, burnup, and cooling time. Under ideal conditions, discounting possible errors of a real world measurement, a root mean square agreement between true and determined total Pu mass of 2.1% is achieved.

  6. Determination of spent nuclear fuel assembly multiplication with the differential die-away self-interrogation instrument

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Alexis C. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Henzl, Vladimir; Menlove, Howard O.; Swinhoe, Martyn T.; Belian, Anthony P. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Flaska, Marek; Pozzi, Sara A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2014-09-01

    We present a novel method for determining the multiplication of a spent nuclear fuel assembly with a Differential Die-Away Self-Interrogation (DDSI) instrument. The signal, which is primarily created by thermal neutrons, is measured with four {sup 3}He detector banks surrounding a spent fuel assembly. The Rossi-alpha distribution (RAD) at early times reflects coincident events from single fissions as well as fission chains. Because of this fact, the early time domain contains information about both the fissile material and spontaneous fission material in the assembly being measured. A single exponential function fit to the early time domain of the RAD has a die-away time proportional to the spent fuel assembly (SFA) multiplication. This correlation was tested by simulating assay of 44 different SFAs with the DDSI instrument. The SFA multiplication was determined with a variance of 0.7%.

  7. Lawfulness of Interrogation Techniques under the Geneva Conventions

    Science.gov (United States)

    2004-09-08

    on Interrogation Process (June 22, 2004), available at [http://www.defenselink.mil/releases/2004/ nr20040622-0930.html]. 2 See A. J . BARKER, PRISONERS...U.S. ARMY JUDGE ADVOCATE SCHOOL, LAW OF WAR WORKSHOP DESKBOOK 83 (CDR Brian J . Bill, ed. 2000) [hereinafter “ L O W D E S K B O O K ” ] , a v a i l...or purpose behind the conduct is a prohibited purpose. See Prosecutor v. Kunarac, Kovac and Vukovic , Nos. IT-96-23 and IT-96-23/11, para. 486 (ITCY

  8. A Directed Signature Scheme and its Applications

    OpenAIRE

    Lal, Sunder; Kumar, Manoj

    2004-01-01

    This paper presents a directed signature scheme with the property that the signature can be verified only with the help of signer or signature receiver. We also propose its applications to share verification of signatures and to threshold cryptosystems.

  9. Fiber-MZI-based FBG sensor interrogation: comparative study with a CCD spectrometer.

    Science.gov (United States)

    Das, Bhargab; Chandra, Vikash

    2016-10-10

    We present an experimental comparative study of the two most commonly used fiber Bragg grating (FBG) sensor interrogation techniques: a charge-coupled device (CCD) spectrometer and a fiber Mach-Zehnder interferometer (F-MZI). Although the interferometric interrogation technique is historically known to offer the highest sensitivity measurements, very little information exists regarding how it compares with the current commercially available spectral-characteristics-based interrogation systems. It is experimentally established here that the performance of a modern-day CCD spectrometer interrogator is very close to a F-MZI interrogator with the capability of measuring Bragg wavelength shifts with sub-picometer-level accuracy. The results presented in this research study can further be used as a guideline for choosing between the two FBG sensor interrogator types for small-amplitude dynamic perturbation measurements down to nano-level strain.

  10. R-process signatures

    International Nuclear Information System (INIS)

    Kratz, K.L.; Pfeiffer, B.

    2003-01-01

    We compare r-process calculations with recent astronomical observations from the solar system and from ultra-metal-poor, neutron-capture-rich halo stars. These measurements include elemental as well as isotopic r-abundances. We deduce astrophysical conditions under which the observed r-patterns can be obtained, and derive criteria to determine Th/U chronometric ages. (orig.)

  11. Elemental analysis using temporal gating of a pulsed neutron generator

    Energy Technology Data Exchange (ETDEWEB)

    Mitra, Sudeep

    2018-02-20

    Technologies related to determining elemental composition of a sample that comprises fissile material are described herein. In a general embodiment, a pulsed neutron generator periodically emits bursts of neutrons, and is synchronized with an analyzer circuit. The bursts of neutrons are used to interrogate the sample, and the sample outputs gamma rays based upon the neutrons impacting the sample. A detector outputs pulses based upon the gamma rays impinging upon the material of the detector, and the analyzer circuit assigns the pulses to temporally-based bins based upon the analyzer circuit being synchronized with the pulsed neutron generator. A computing device outputs data that is indicative of elemental composition of the sample based upon the binned pulses.

  12. Accelerating fissile material detection with a neutron source

    Science.gov (United States)

    Rowland, Mark S.; Snyderman, Neal J.

    2018-01-30

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly to count neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. The system includes a Poisson neutron generator for in-beam interrogation of a possible fissile neutron source and a DC power supply that exhibits electrical ripple on the order of less than one part per million. Certain voltage multiplier circuits, such as Cockroft-Walton voltage multipliers, are used to enhance the effective of series resistor-inductor circuits components to reduce the ripple associated with traditional AC rectified, high voltage DC power supplies.

  13. NELIS - a Neutron Inspection System for Detection of Illicit Drugs

    International Nuclear Information System (INIS)

    Barzilov, Alexander P.; Womble, Phillip C.; Vourvopoulos, George

    2003-01-01

    NELIS (Neutron ELemental Inspection System) is currently being developed to inspect cargo pallets for illicit drugs. NELIS must be used in conjunction with an x-ray imaging system to optimize the inspection capabilities at ports of entry. Pulsed fast-thermal neutron analysis is utilized to measure the major and minor chemical elements in a non-destructive and non-intrusive manner. Fourteen-MeV neutrons produced with a pulsed d-T neutron generator are the interrogating particles. NELIS analyzes the characteristic gamma rays emitted from the object that are produced by nuclear reactions from fast and thermal neutrons. These gamma rays have different energies for each chemical element, and act as their fingerprints. Since the elemental composition of illicit drugs is quite different from that of innocuous materials, drugs hidden in pallets are identified through the comparison of expected and measured elemental composition and ratios. Results of tests of the system will be discussed

  14. On the anti-neutron bomb movement in the Netherlands

    International Nuclear Information System (INIS)

    Hoek, T. van.

    1978-01-01

    The author reports on activities of the Dutch activists group Stop the neutron bomb in his country: Collection of signatures, statements made by about a hundred well-known theologians, two-thirds majority in parliament against the production and emplacement of the neutron bomb, International Forum 1978 in Amsterdam with mass demonstrations. President Carter is said to have been forced to delay the production of the neutron bomb temporarily by means of this international pressure. (HSCH) [de

  15. Real time interrogation technique for fiber Bragg grating enhanced fiber loop ringdown sensors array.

    Science.gov (United States)

    Zhang, Yunlong; Li, Ruoming; Shi, Yuechun; Zhang, Jintao; Chen, Xiangfei; Liu, Shengchun

    2015-06-01

    A novel fiber Bragg grating aided fiber loop ringdown (FLRD) sensor array and the wavelength-time multiplexing based interrogation technique for the FLRD sensors array are proposed. The interrogation frequency of the system is formulated and the interrelationships among the parameters of the system are analyzed. To validate the performance of the proposed system, a five elements array is experimentally demonstrated, and the system shows the capability of real time monitoring every FLRD element with interrogation frequency of 125.5 Hz.

  16. Police interviewing and interrogation of juvenile suspects: a descriptive examination of actual cases.

    Science.gov (United States)

    Cleary, Hayley M D

    2014-06-01

    Although empirical attention to police interrogation has gained traction in recent years, comparatively few studies have examined interrogation of juvenile suspects, and virtually none have examined actual interrogations. Despite a growing literature on youths' interrogation-related capacities, we still know very little about what actually transpires when police question youth. The present study examines electronically recorded police interviews with juveniles to describe the characteristics, processes, and outcomes that occur in actual juvenile interrogations, including interview duration, individuals present, and confessions. Fifty-seven electronic recordings from 17 police departments were analyzed using observational research software. The median juvenile interrogation lasted 46 min, though the range was extensive (6 min to nearly 5 hr). Youth frequently submitted to questioning without a parent or advocate present, and disruptions to the interview process were common. Interrogation outcomes varied and included full confessions, partially incriminating admissions, and denials of guilt. Results from this study provide context for interrogation research using other methods and suggest that youth may frequently consent to interrogation in the absence of important legal protections.

  17. Determination of Interrogating Frequencies to Maximize Electromagnetic Backscatter from Objects with Material Coatings

    National Research Council Canada - National Science Library

    Banks, H. T; Ito, K; Toivanen, J

    2005-01-01

    .... Based on the radar cross section and a reflection coefficient, optimization problems are formulated for evaders and interrogators leading to optimal material parameters for the coating and optimal...

  18. Remotely Interrogated Passive Polarizing Dosimeter (RIPPeD).

    Energy Technology Data Exchange (ETDEWEB)

    Kemme, Shanalyn A.; Buller, Daniel L.; Dirk, Shawn M.; Boye, Robert R.; Samora, Sally; Washburn, Cody M.; Wheeler, David Roger

    2008-09-01

    Conductive polymers have become an extremely useful class of materials for many optical applications. We have developed an electrochemical growth method for depositing highly conductive ({approx}100 S/cm) polypyrrole. Additionally, we have adapted advanced fabrication methods for use with the polypyrrole resulting in gratings with submicron features. This conductive polymer micro-wire grid provides an optical polarizer with unique properties. When the polymer is exposed to ionizing radiation, its conductivity is affected and the polarization properties of the device, specifically the extinction ratio, change in a corresponding manner. This change in polarization properties can be determined by optically interrogating the device, possibly from a remote location. The result is a passive radiation-sensitive sensor with very low optical visibility. The ability to interrogate the device from a safe standoff distance provides a device useful in potentially dangerous environments. Also, the passive nature of the device make it applicable in applications where external power is not available. We will review the polymer deposition, fabrication methods and device design and modeling. The characterization of the polymer's sensitivity to ionizing radiation and optical testing of infrared polarizers before and after irradiation will also be presented. These experimental results will highlight the usefulness of the conductive infrared polarizer to many security and monitoring applications.

  19. Performance of an optical identification and interrogation system

    Science.gov (United States)

    Venugopalan, A.; Ghosh, A. K.; Verma, P.; Cheng, S.

    2008-04-01

    A free space optics based identification and interrogation system has been designed. The applications of the proposed system lie primarily in areas which require a secure means of mutual identification and information exchange between optical readers and tags. Conventional RFIDs raise issues regarding security threats, electromagnetic interference and health safety. The security of RF-ID chips is low due to the wide spatial spread of radio waves. Malicious nodes can read data being transmitted on the network, if they are in the receiving range. The proposed system provides an alternative which utilizes the narrow paraxial beams of lasers and an RSA-based authentication scheme. These provide enhanced security to communication between a tag and the base station or reader. The optical reader can also perform remote identification and the tag can be read from a far off distance, given line of sight. The free space optical identification and interrogation system can be used for inventory management, security systems at airports, port security, communication with high security systems, etc. to name a few. The proposed system was implemented with low-cost, off-the-shelf components and its performance in terms of throughput and bit error rate has been measured and analyzed. The range of operation with a bit-error-rate lower than 10-9 was measured to be about 4.5 m. The security of the system is based on the strengths of the RSA encryption scheme implemented using more than 1024 bits.

  20. Remotely Interrogated Passive Polarizing Dosimeter (RIPPeD)

    International Nuclear Information System (INIS)

    Kemme, Shanalyn A.; Buller, Daniel L.; Dirk, Shawn M.; Boye, Robert R.; Samora, Sally; Washburn, Cody M.; Wheeler, David Roger

    2008-01-01

    Conductive polymers have become an extremely useful class of materials for many optical applications. We have developed an electrochemical growth method for depositing highly conductive (∼100 S/cm) polypyrrole. Additionally, we have adapted advanced fabrication methods for use with the polypyrrole resulting in gratings with submicron features. This conductive polymer micro-wire grid provides an optical polarizer with unique properties. When the polymer is exposed to ionizing radiation, its conductivity is affected and the polarization properties of the device, specifically the extinction ratio, change in a corresponding manner. This change in polarization properties can be determined by optically interrogating the device, possibly from a remote location. The result is a passive radiation-sensitive sensor with very low optical visibility. The ability to interrogate the device from a safe standoff distance provides a device useful in potentially dangerous environments. Also, the passive nature of the device make it applicable in applications where external power is not available. We will review the polymer deposition, fabrication methods and device design and modeling. The characterization of the polymer's sensitivity to ionizing radiation and optical testing of infrared polarizers before and after irradiation will also be presented. These experimental results will highlight the usefulness of the conductive infrared polarizer to many security and monitoring applications

  1. The captive brain: torture and the neuroscience of humane interrogation.

    Science.gov (United States)

    O'Mara, S

    2018-02-01

    Despite it being abhorrent and illegal, torture is sometimes employed for information gathering. However, the extreme stressors employed during torture force the brain away from the relatively narrow, adaptive range of function it operates within. Torture degrades signal-to-noise ratios of information yield and increases false positive discovery rates. As a discovery methodology, torture fails basic tests of veridical, reliable and replicable information discovery. Torture fails during interrogation because it is an assault on our core integrated, social, psychological and neural functioning. There is a need for a profound cultural shift regarding torture, recognizing that torture impairs, rather than facilitates, investigations and truth-finding. Rising to this challenge will increase operational effectiveness, eliminate prisoner abuse and torment, and aid veridical and actionable information gathering. Policy regarding prisoner and detainee interrogation need to be refocused as a behavioural and brain sciences problem, and not simply treated as a legal, ethical or philosophical problem. Getting the science, ethics and practice in line is a challenge, but it can and should be done.

  2. Optical Stabilization of a Microwave Oscillator for Fountain Clock Interrogation.

    Science.gov (United States)

    Lipphardt, Burghard; Gerginov, Vladislav; Weyers, Stefan

    2017-04-01

    We describe an optical frequency stabilization scheme of a microwave oscillator that is used for the interrogation of primary cesium fountain clocks. Because of its superior phase noise properties, this scheme, which is based on an ultrastable laser and a femtosecond laser frequency comb, overcomes the frequency instability limitations of fountain clocks given by the previously utilized quartz-oscillator-based frequency synthesis. The presented scheme combines the transfer of the short-term frequency instability of an optical cavity and the long-term frequency instability of a hydrogen maser to the microwave oscillator and is designed to provide continuous long-term operation for extended measurement periods of several weeks. The utilization of the twofold stabilization scheme on the one hand ensures the referencing of the fountain frequency to the hydrogen maser frequency and on the other hand results in a phase noise level of the fountain interrogation signal, which enables fountain frequency instabilities at the 2.5 ×10 -14 (τ/s) -1/2 level that are quantum projection noise limited.

  3. Age and interviewer behavior as predictors of interrogative suggestibility.

    Science.gov (United States)

    Dukala, Karolina; Polczyk, Romuald

    2014-05-01

    The main objective was to explore the influence of interviewer behavior-abrupt versus friendly-and the age of participants on interrogative suggestibility. The study involved 42 young adults and 50 elderly participants. The Gudjonsson Suggestibility Scale 2 was used. Data analysis involved a 2-factor between-subjects design (interviewer behavior × age) and mediation analysis. The scores of elderly participants were significantly lower than younger adults on memory indices and significantly higher on some suggestibility indexes. Some suggestibility indices in the abrupt experimental condition were higher than those in the friendly experimental condition. Elderly participants who were interviewed under the abrupt condition were more likely to change their answers after receiving negative feedback than younger adults. Memory quality was a mediator of the relationship between age and the tendency to yield to suggestive questions. Self-appraisal of memory was a mediator between both age and interviewer behavior and the tendency to change answers after negative feedback. Mechanisms of the relationship between age, interviewer behavior, and suggestibility are discussed on the basis of the mediational analyses. The findings suggest that a friendly manner should be adopted when interrogating witnesses.

  4. Neutron radiography

    International Nuclear Information System (INIS)

    Hiraoka, Eiichi

    1988-01-01

    The thermal neutron absorption coefficient is essentially different from the X-ray absorption coefficient. Each substance has a characteristic absorption coefficient regardless of its density. Neutron deams have the following features: (1) neutrons are not transmitted efficiently by low molecular weight substances, (2) they are transmitted efficiently by heavy metals, and (3) the transmittance differs among isotopes. Thus, neutron beams are suitable for cheking for foreign matters in heavy metals and testing of composites consisting of both heavy and light materials. A neutron source generates fast neutrons, which should be converted into thermal neutrons by reducing their energy. Major neutron souces include nuclear reactors, radioisotopes and particle accelerators. Photographic films and television systems are mainly used to observe neutron transmission images. Computers are employed for image processing, computerized tomography and three-dimensional analysis. The major applications of neutron radiography include inspection of neclear fuel; evaluation of material for airplane; observation of fuel in the engine and oil in the hydraulic systems in airplanes; testing of composite materials; etc. (Nogami, K.)

  5. System and plastic scintillator for discrimination of thermal neutron, fast neutron, and gamma radiation

    Science.gov (United States)

    Zaitseva, Natalia P.; Carman, M. Leslie; Faust, Michelle A.; Glenn, Andrew M.; Martinez, H. Paul; Pawelczak, Iwona A.; Payne, Stephen A.

    2017-05-16

    A scintillator material according to one embodiment includes a polymer matrix; a primary dye in the polymer matrix, the primary dye being a fluorescent dye, the primary dye being present in an amount of 3 wt % or more; and at least one component in the polymer matrix, the component being selected from a group consisting of B, Li, Gd, a B-containing compound, a Li-containing compound and a Gd-containing compound, wherein the scintillator material exhibits an optical response signature for thermal neutrons that is different than an optical response signature for fast neutrons and gamma rays. A system according to one embodiment includes a scintillator material as disclosed herein and a photodetector for detecting the response of the material to fast neutron, thermal neutron and gamma ray irradiation.

  6. Identification of neutron noise sources in a boiling water reactor

    International Nuclear Information System (INIS)

    Sides, W.H. Jr.; Mathis, M.V.; Smith, C.M.

    1977-01-01

    Measurements were made at units 2 and 3 of the Browns Ferry Nuclear Power Plant in order to characterize the noise signatures of the neutron and process signals and to determine the usefulness of such signatures for anomaly detection in BWR-4s. Previous measurements and theoretical analyses of BWR noise by others were concerned with the determination of steam velocity and void fraction (using the local component of neutron noise) and with the sources of global noise. The work described is under a five-part program to develop a complete and systematic analysis and representation of BWR neutron and process noise through complementary measurements and stochastic model developments. The parts are: (1) recording as many neutron detector and process noise signals as are available in a BWR-4; (2) reducing these data to noise signatures in order to perform an empirical analysis of these signatures, and documenting the relationships between the signals from spatially separated neutron detectors and between neutron and process variables; (3) developing spatially dependent neutronic models coupled with thermal-hydraulic models to aid in interpreting the observed relationships among the measured noise signatures, (4) comparing measured noise signatures with model predictions to obtain additional insight into BWR-4 dynamic behavior and to validate the models; and (5) using these models to predict the sensitivity of noise monitoring for detection, surveillance, and diagnosis of postulated in-core anomalies in BWRs. The paper describes the procedures used to obtain the noise recordings and presents initial empirical analysis and observations pertaining to the noise signatures and the relationships between several noise variables in the 0.01- to 1-Hz range. The mathematical models have not been developed sufficiently to report theoretical results or to compare measured spectra with model predictions at this time

  7. Radioisotopes produced by neutron irradiation of food

    International Nuclear Information System (INIS)

    Albright, S.; Seviour, R.

    2016-01-01

    The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of "2"4Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total activity and the ingestion dose we show that a variety of isotopes contribute and that "2"4Na is only dominant under certain conditions. The composition of the foods has a strong influence on the resulting activity and ingestion dose suggesting that the pharmaceuticals and medical devices considered initially are not a viable analogue for foodstuffs. There is an energy dependence to the isotopes produced due to the cross-sections of different reactions varying with neutron energy. We show that this results in different isotopes dominating the ingestion dose at different energies, which has not been considered in the previous literature. - Highlights: • We show that neutron interrogation of food can produce many radioisotopes. • We show a strong dependance between food and certain radioisotopes. • Some isotopes are shown to have an energy dependence. • Previous claims that 24Na is the main threat is shown to only apply in special cases.

  8. Neutron detector

    Science.gov (United States)

    Stephan, Andrew C [Knoxville, TN; Jardret,; Vincent, D [Powell, TN

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  9. Fusion neutronics

    CERN Document Server

    Wu, Yican

    2017-01-01

    This book provides a systematic and comprehensive introduction to fusion neutronics, covering all key topics from the fundamental theories and methodologies, as well as a wide range of fusion system designs and experiments. It is the first-ever book focusing on the subject of fusion neutronics research. Compared with other nuclear devices such as fission reactors and accelerators, fusion systems are normally characterized by their complex geometry and nuclear physics, which entail new challenges for neutronics such as complicated modeling, deep penetration, low simulation efficiency, multi-physics coupling, etc. The book focuses on the neutronics characteristics of fusion systems and introduces a series of theories and methodologies that were developed to address the challenges of fusion neutronics, and which have since been widely applied all over the world. Further, it introduces readers to neutronics design’s unique principles and procedures, experimental methodologies and technologies for fusion systems...

  10. Neutron spectometers

    International Nuclear Information System (INIS)

    Poortmans, F.

    1977-01-01

    Experimental work in the field of low-energy neutron physics can be subdivided into two classes: 1)Study of the decay process of the compound-nucleus state as for example the study of the capture gamma rays and of the neutron induced fission process; 2)Study of the reaction mechanism, mainly by measuring the reaction cross-sections and resonance parameters. These neutron cross-sections and resonance parameters are also important data required for many technological applications especially for reactor development programmes. In general, the second class of experiments impose other requirements on the neutron spectrometer than the first class. In most cases, a better neutron energy resolution and a broader neutron energy range are required for the study of the reaction mechanism than for the study of various aspects of the decay process. (author)

  11. Signatures of topological superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Yang

    2017-07-19

    The prediction and experimental discovery of topological insulators brought the importance of topology in condensed matter physics into the limelight. Topology hence acts as a new dimension along which more and more new states of matter start to emerge. One of these topological states of matter, namely topological superconductors, comes into the focus because of their gapless excitations. These gapless excitations, especially in one dimensional topological superconductors, are Majorana zero modes localized at the ends of the superconductor and exhibit exotic nonabelian statistics, which can be potentially applied to fault-tolerant quantum computation. Given their highly interesting physical properties and potential applications to quantum computation, both theorists and experimentalists spend great efforts to realize topological supercondoctors and to detect Majoranas. In two projects within this thesis, we investigate the properties of Majorana zero modes in realistic materials which are absent in simple theoretical models. We find that the superconducting proximity effect, an essential ingredient in all existing platforms for topological superconductors, plays a significant role in determining the localization property of the Majoranas. Strong proximity coupling between the normal system and the superconducting substrate can lead to strongly localized Majoranas, which can explain the observation in a recent experiment. Motivated by experiments in Molenkamp's group, we also look at realistic quantum spin Hall Josephson junctions, in which charge puddles acting as magnetic impurities are coupled to the helical edge states. We find that with this setup, the junction generically realizes an exotic 8π periodic Josephson effect, which is absent in a pristine Josephson junction. In another two projects, we propose more pronounced signatures of Majoranas that are accessible with current experimental techniques. The first one is a transport measurement, which uses

  12. Modem Signature Analysis.

    Science.gov (United States)

    1982-10-01

    AD-A127 993 MODEM SIGNATURE ANALISIS (U) PAR TECHNOLOGY CORP NEW / HARTFORD NY V EDWARDS ET AL. OCT 82 RADC-TR-82-269 F30602-80-C-0264 NCLASSIFIED F/G...as an indication of the class clustering and separation between different classes in the modem data base. It is apparent from the projection that the...that as the clusters disperse, the likelihood of a sample crossing the boundary into an adjacent region and causing a symbol decision error increases. As

  13. Neutron exposure

    International Nuclear Information System (INIS)

    Prillinger, G.; Konynenburg, R.A. van

    1998-01-01

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. In chapter 6, LWR-PV neutron transport calculations and dosimetry methods and how they are combined to evaluate the neutron exposure of the steel of pressure vessels are discussed. An effort to correlate neutron exposure parameters with damage is made

  14. Atmospheric neutrons

    International Nuclear Information System (INIS)

    Preszler, A.M.; Moon, S.; White, R.S.

    1976-01-01

    Additional calibrations of the University of California double-scatter neutron and additional analysis corrections lead to the slightly changed neutron fluxes reported here. The theoretical angular distributions of Merker (1975) are in general agreement with our experimental fluxes but do not give the peaks for vertical upward and downward moving neutrons. The theoretical neutron escape current J 2 /sub pi/ (Merker, 1972; Armstrong et al., 1973) is in agreement with the experimental values from 10 to 100 MeV. Our experimental fluxes agree with those of the Kanbach et al. (1974) in the overlap region from 70 to 100 MeV

  15. Neutron Albedo

    CERN Document Server

    Ignatovich, V K

    2005-01-01

    A new, algebraic, method is applied to calculation of neutron albedo from substance to check the claim that use of ultradispersive fuel and moderator of an active core can help to gain in size and mass of the reactor. In a model of isotropic distribution of incident and reflected neutrons it is shown that coherent scattering on separate grains in the case of thermal neutrons increases transport cross section negligibly, however it decreases albedo from a wall of finite thickness because of decrease of substance density. A visible increase of albedo takes place only for neutrons with wave length of the order of the size of a single grain.

  16. Measure of uranium enrichment by 14 MeV neutron irradiation

    International Nuclear Information System (INIS)

    Rezende, H.R.

    1987-01-01

    A non-destructive technique for the determination of uranium in UO 2 samples was developed, marking use of the change in the fission cross of a nuclide with the neutron energy. The active interrogation method was used by irradiating the samples with pulsed 14 MeV neutrons and furtherdetection of delayed fission neutrons. In order to descriminated U-238 from U-235 the neutron energy was tailored by means of two concentric cylinders of lead and paraffin/poliethylene, 11 and 4 cm thick. Between neutron pulses, delayed neutrons from fission were detected by a long counter built with five BF 3 proportional counters. Calibration curves for enrichment and total mass versus delayed neutron response were obtained using available UO 2 pellets of Known enrichment. Enrichment detection limit, obtained with 95% confidence level by the the Student distribution was estimated to be 0.33%. The minimal detectable mass was estimated to be 4.4 g. (Author) [pt

  17. Measurement of uranium enrichment by 14 MeV neutron irradiation

    International Nuclear Information System (INIS)

    Rezende, H.R.

    1987-01-01

    a non-destructive technique for the determination of uranium in UO 2 samples was developed, making use of the change in the fission cross section of a nuclide with the neutron energy. The active interrogation method was used by irradiating the samples with pulsed 14 MeV neutrons and further detection of delayed fission neutrons. In order to discriminate U-238 from U-235 the neutron energy was tailored by means of two concentric cylinders of lead and paraffin/poliethylene, 11 and 4 cm thick. Between neutron pulses, delayed neutrons from fission were detected by a long counter built with five BF 3 proportional counters. Calibration curves for enrichment and total mass versus delayed neutron response were obtained using available UO 2 pellets of known enrichment. Enrichment detection limit, obtained with 95% confidence level by the Student distribution was estimated to be 0.33%. The minimal detectable mass was estimated to be 4.4 g. (author) [pt

  18. Improving differential die-away analysis via the use of neutron poisons in detectors

    International Nuclear Information System (INIS)

    Jordan, Kelly A.; Vujic, Jasmina; Phillips, Emmanuel; Gozani, Tsahi

    2007-01-01

    Differential Die-Away Analysis (DDAA) is an active interrogation technique to detect special nuclear material (SNM). In DDAA, a pulsed neutron generator produces pulses of neutrons that are directed into a cargo to be interrogated. As each pulse passes through the cargo, the neutrons are thermalized and absorbed. If SNM is present, the thermalized neutrons from the source will cause fissions that produce a new source of neutrons. The number of thermal neutrons decay exponentially with the diffusion decay time of the inspected medium, on the order of hundreds of μs. An external neutron detector which is designed to detect only epithermal neutrons, will measure only a single decaying exponential when there is no SNM present, and two exponentials when SNM is present. This paper shows that in many cases, a gain in detection sensitivity can be realized by introducing a thermal neutron poison (such as boron) into the detector. This poison will reduce the efficiency of the detector, but decrease its decay time. A decreased decay time will cause the separation between the detector and fission signal exponentials to occur at an earlier time. There is a balance between efficiency and time constant for a detector. The boron concentration to achieve the maximum sensitivity, and its magnitude, will be different for different detector designs

  19. Psychologists abandon the Nuremberg ethic: concerns for detainee interrogations.

    Science.gov (United States)

    Pope, Kenneth S; Gutheil, Thomas G

    2009-01-01

    In the aftermath of 9-11, the American Psychological Association, one of the largest U.S. health professions, changed its ethics code so that it now runs counter to the Nuremberg Ethic. This historic post-9-11 change allows psychologists to set aside their ethical responsibilities whenever they are in irreconcilable conflict with military orders, governmental regulations, national and local laws, and other forms of governing legal authority. This article discusses the history, wording, rationale, and implications of the ethical standard that U.S. psychologists adopted 7 years ago, particularly in light of concerns over health care professionals' involvement in detainee interrogations and the controversy over psychologists' prominent involvement in settings like the Guantánamo Bay Detainment Camp and the Abu Ghraib prison. It discusses possible approaches to the complex dilemmas arising when ethical responsibilities conflict with laws, regulations, or other governing legal authority.

  20. Genome interrogation for novel salinity tolerant Arabidopsis mutants.

    Science.gov (United States)

    van Tol, Niels; Pinas, Johan; Schat, Henk; Hooykaas, Paul J J; van der Zaal, Bert J

    2016-12-01

    Soil salinity is becoming an increasingly large problem in agriculture. In this study, we have investigated whether a capacity to withstand salinity can be induced in the salinity sensitive plant species Arabidopsis thaliana, and whether it can be maintained in subsequent generations. To this end, we have used zinc finger artificial transcription factor (ZF-ATFs) mediated genome interrogation. Already within a relatively small collection Arabidopsis lines expressing ZF-ATFs, we found 41 lines that were tolerant to 100 mM NaCl. Furthermore, ZF-ATF encoding gene constructs rescued from the most strongly salinity tolerant lines were indeed found to act as dominant and heritable agents for salinity tolerance. Altogether, our data provide evidence that a silent capacity to withstand normally lethal levels of salinity exists in Arabidopsis and can be evoked relatively easily by in trans acting transcription factors like ZF-ATFs. © 2016 John Wiley & Sons Ltd.

  1. Queering marriage: an ideographic interrogation of heteronormative subjectivity.

    Science.gov (United States)

    Grindstaff, Davin

    2003-01-01

    Recent debates on same-sex marriage mark the institution, practice, and concept of marriage as a significant site of power and resistance within American culture. Adopting Michel Foucault's conception of "discipline," this essay examines how marriage discourse reinforces heteronormative power relations through its rhetorical constitution of gay male identity. Supplementing "ideographic" critique with Judith Butler's theory of performative speech acts enables us to better interrogate and resist these operations of power. This essay maps the contemporary scene of heteronormative power and resistance through two rhetorical performances of gay male identity. The marriage debates, in the first instance, demonstrate how a conventional desire for masculine agency influences the heteronormative production of gay male identity. In the second instance, gay male SM [sadomasochism] performs a concept of "relational agency," which potentially resists heteronormativity.

  2. The Sociocultural Psychology as a Postformal Theory of Academic Achievement: Interrogating Formal Education

    Science.gov (United States)

    Sinha, Chetan

    2013-01-01

    The present paper interrogates the dominance of formal education. As formal education system relies on ability based academic achievement as a goal, exploring post-formal approaches, such as sociocultural notion of academic achievement is the hallmark of present paper. An attempt is made to interrogate the existing cultural dominance in formal…

  3. Using Elaborative Interrogation Enhanced Worked Examples to Improve Chemistry Problem Solving

    Science.gov (United States)

    Pease, Rebecca Simpson

    2012-01-01

    Elaborative interrogation, which prompts students to answer why-questions placed strategically within informational text, has been shown to increase learning comprehension through reading. In this study, elaborative interrogation why-questions requested readers to explain why paraphrased statements taken from a reading were "true."…

  4. Diagnostic yield of device interrogation in the evaluation of syncope in an elderly population.

    Science.gov (United States)

    D'Angelo, Robert N; Pickett, Christopher C

    2017-06-01

    Device interrogation has become a standard part of the syncope evaluation for patients admitted with permanent pacemakers (PPM) or implantable cardiac defibrillators (ICD), although few studies have shown interrogation yields clinically useful data. The purpose of this study is to determine the diagnostic yield of device interrogation as well as other commonly performed tests in the workup of unexplained syncope in patients with previously implanted PPMs or ICDs. We retrospectively reviewed records of 88 patients admitted to our medical center for syncope with previously implanted pacemakers between January 1, 2005 and January 1, 2015 using ICD-9 billing data. Pacemaker interrogation demonstrated an arrhythmia as the cause for syncope in 4 patients (4%) and evidence of device failure secondary to perforation in 1 patient (1%). The cause of syncope was unknown in 34 patients (39%). Orthostatic hypotension was the most commonly identified cause of syncope (26%), followed by vasovagal syncope (13%), autonomic dysfunction (5%), ventricular arrhythmia (3%), atrial arrhythmia (2%), congestive heart failure (2%), stroke (2%), and other less common causes (8%). History was the most important determinant of syncope (36%), followed by orthostatic vital signs (14%), device interrogations (4%), head CT (2%), and transthoracic echocardiogram (1%). Device interrogation is rarely useful for elucidating a cause of syncope without concerning physical exam, telemetry, or EKG findings. Interrogation may occasionally yield paroxysmal arrhythmias responsible for syncopal episode, but these rarely alter clinical outcomes. Interrogation appears to be more useful in patients with syncope after recent device placement. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  5. Interrogating "Belonging" in Belonging, Being and Becoming: The Early Years Learning Framework for Australia

    Science.gov (United States)

    Sumsion, Jennifer; Wong, Sandie

    2011-01-01

    In this article, the authors interrogate the use of "belonging" in "Belonging, Being and Becoming: the Early Years Learning Framework for Australia" (EYLF), Australia's first national curriculum for early childhood education and care settings and, from the authors' interrogation, possibilities are offered for thinking about and…

  6. PELAN - a transportable, neutron-based UXO identification technique

    International Nuclear Information System (INIS)

    Vourvopoulos, G.

    1998-01-01

    An elemental characterization method is used to differentiate between inert projectiles and UXO's. This method identifies in a non-intrusive, nondestructive manner, the elemental composition of the projectile contents. Most major and minor chemical elements within the interrogated object (hydrogen, carbon, nitrogen, oxygen, fluorine, phosphorus, chlorine, arsenic, etc.) are identified and quantified. The method is based on PELAN - Pulsed Elemental Analysis with Neutrons. PELAN uses pulsed neutrons produced from a compact, sealed tube neutron generator. Using an automatic analysis computer program, the quantities of each major and minor chemical element are determined. A decision-making tree identifies the object by comparing its elemental composition with stored elemental composition libraries of substances that could be contained within the projectile. In a series of blind tests, PELAN was able to identify without failure, the contents of each shell placed in front of it. The PELAN probe does not need to be in contact with the interrogated projectile. If the object is buried, the interrogation can take place in situ provided the probe can be inserted a few centimeters from the object's surface. (author)

  7. Interrogated with Intellectual Disabilities: The Risks of False Confession.

    Science.gov (United States)

    Schatz, Samson J

    2018-02-01

    False confessions happen. At least 245 people have been exonerated from convictions in cases featuring confessions that were simply not true. Confessions offer a narrative that allows law enforcement, and society in general, to neatly resolve cases with apparent clarity and closure. And yet the pressures officers place on suspects to provide that closure weigh disproportionately on the vulnerable, including individuals with intellectual disabilities. These individuals are disadvantaged at every step of the custodial interrogation, and they face heightened risks of falsely confessing. Moreover, the principal judicial safeguards against false confessions--assessing a suspect's Miranda waiver and determining whether a confession was voluntarily given within the bounds of the Fourteenth Amendment’s Due Process Clause--provide little protection for the innocent with intellectual disabilities. Few pieces of scholarship focus specifically on the heightened risks faced by individuals with intellectual disabilities throughout the process of police interrogation. This Note describes the various ways these individuals are disadvantaged. And it offers an additional data point illustrating the vulnerability of people with intellectual disabilities. This Note analyzes the 245 individuals (as of June 2, 2017) on the National Registry of Exonerations who have falsely confessed. Over one-quarter of them display indicia of intellectual disability. This percentage dwarfs the prevalence of people with intellectual disabilities in the general population and even exceeds most estimates of the proportion of the prison population suffering from intellectual disabilities. This Note concludes with several policy and doctrinal suggestions to better protect individuals with intellectual disabilities from the risks of false confession.

  8. Coaxial Mono-Energetic Gamma Generator for Active Interrogation

    International Nuclear Information System (INIS)

    Ludewigt, Bernhard A.; Antolak, A.J.; Henestroza, E.; Leitner, M.; Leung, K.-N.; Waldron, W.; Wilde, S.; Kwan, J.W.

    2008-01-01

    Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,gamma)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the 11B(p,gamma)12C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB6 tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with 20 mu s long pulses, and a 1percent duty factor by pulsing the ion source rf-power. A first-generation coaxial gamma source has been built for low duty factor experiments and testing.

  9. Miniature fiber Bragg grating sensor interrogator (FBG-Transceiver) system

    Science.gov (United States)

    Mendoza, Edgar A.; Kempen, Cornelia; Lopatin, Craig

    2007-04-01

    This paper describes recent progress conducted towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-Transceiver TM) system based on multi-channel integrated optic sensor (InOSense TM) microchip technology. The hybrid InOSense TM microchip technology enables the integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogator systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation. The FBG-Transceiver system uses active optoelectronic components monolithically integrated to the InOSense TM microchip, a microprocessor controlled signal processing electronics board capable of processing the FBG sensors signals related to stress-strain and temperature as well as vibration and acoustics. The FBG-Transceiver TM system represents a new, reliable, highly robust technology that can be used to accurately monitor the status of an array of distributed fiber optic Bragg grating sensors installed in critical infrastructures. Its miniature package, low power operation, and state-of-the-art data communications architecture, all at a very affordable price makes it a very attractive solution for a large number of SHM/NDI applications in aerospace, naval and maritime industry, civil structures like bridges, buildings and dams, the oil and chemical industry, and for homeland security applications. The miniature, cost-efficient FBG-Transceiver TM system is poised to revolutionize the field of structural health monitoring and nondestructive inspection market. The sponsor of this program is NAVAIR under a DOD SBIR contract.

  10. Electronic Signature (eSig)

    Data.gov (United States)

    Department of Veterans Affairs — Beginning with the Government Paperwork Elimination Act of 1998 (GPEA), the Federal government has encouraged the use of electronic / digital signatures to enable...

  11. Expressiveness considerations of XML signatures

    DEFF Research Database (Denmark)

    Jensen, Meiko; Meyer, Christopher

    2011-01-01

    XML Signatures are used to protect XML-based Web Service communication against a broad range of attacks related to man-in-the-middle scenarios. However, due to the complexity of the Web Services specification landscape, the task of applying XML Signatures in a robust and reliable manner becomes...... more and more challenging. In this paper, we investigate this issue, describing how an attacker can still interfere with Web Services communication even in the presence of XML Signatures. Additionally, we discuss the interrelation of XML Signatures and XML Encryption, focussing on their security...

  12. Electronic Warfare Signature Measurement Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Electronic Warfare Signature Measurement Facility contains specialized mobile spectral, radiometric, and imaging measurement systems to characterize ultraviolet,...

  13. Neutron dosimetry; Dosimetria de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Fratin, Luciano

    1993-12-31

    A neutron irradiation facility was designed and built in order to establish a procedure for calibrating neutron monitors and dosemeters. A 185 GBq {sup 241} Am Be source of known is used as a reference source. The irradiation facility using this source in the air provides neutron dose rates between 9 nSv s{sup -1} and 0,5 {sup {mu}}Sv s{sup -1}. A calibrated 50 nSv s{sup -1} thermal neutron field is obtained by using a specially designed paraffin block in conjunction with the {sup 241} Am Be source. A Bonner multisphere spectrometer was calibrated, using a procedure based on three methods proposed by international standards. The unfold {sup 241} Am Be neutron spectrum was determined from the Bonner spheres data and resulted in a good agreement with expected values for fluence rate, dose rate and mean energy. A dosimetric system based on the electrochemical etching of CR-39 was developed for personal dosimetry. The dosemeter badge using a (n,{alpha}) converter, the etching chamber and high frequency power supply were designed and built specially for this project. The electrochemical etching (ECE) parameters used were: a 6N KOH solution, 59 deg C, 20 kV{sub pp} cm{sup -1}, 2,0 kHz, 3 hours of ECE for thermal and intermediate neutrons and 6 hours for fast neutrons. The calibration factors for thermal, intermediate and fast neutrons were determined for this personal dosemeter. The sensitivities determined for the developed dosimetric system were (1,46{+-} 0,09) 10{sup 4} tracks cm{sup -2} mSv{sup -1} for thermal neutrons, (9{+-}3) 10{sup 2} tracks cm{sup -2} mSV{sup -1} for intermediate neutrons and (26{+-}4) tracks cm{sup -2} mSv{sup -1} for fast neutrons. The lower and upper limits of detection were respectively 0,002 mSv and 0,6 mSv for thermal neutrons, 0,04 mSv and 8 mSv for intermediate neutrons and 1 mSv and 12 mSv for fast neutrons. In view of the 1990`s ICRP recommendations, it is possible to conclude that the personal dosemeter described in this work is

  14. Neutron dosimetry; Dosimetria de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Fratin, Luciano

    1994-12-31

    A neutron irradiation facility was designed and built in order to establish a procedure for calibrating neutron monitors and dosemeters. A 185 GBq {sup 241} Am Be source of known is used as a reference source. The irradiation facility using this source in the air provides neutron dose rates between 9 nSv s{sup -1} and 0,5 {sup {mu}}Sv s{sup -1}. A calibrated 50 nSv s{sup -1} thermal neutron field is obtained by using a specially designed paraffin block in conjunction with the {sup 241} Am Be source. A Bonner multisphere spectrometer was calibrated, using a procedure based on three methods proposed by international standards. The unfold {sup 241} Am Be neutron spectrum was determined from the Bonner spheres data and resulted in a good agreement with expected values for fluence rate, dose rate and mean energy. A dosimetric system based on the electrochemical etching of CR-39 was developed for personal dosimetry. The dosemeter badge using a (n,{alpha}) converter, the etching chamber and high frequency power supply were designed and built specially for this project. The electrochemical etching (ECE) parameters used were: a 6N KOH solution, 59 deg C, 20 kV{sub pp} cm{sup -1}, 2,0 kHz, 3 hours of ECE for thermal and intermediate neutrons and 6 hours for fast neutrons. The calibration factors for thermal, intermediate and fast neutrons were determined for this personal dosemeter. The sensitivities determined for the developed dosimetric system were (1,46{+-} 0,09) 10{sup 4} tracks cm{sup -2} mSv{sup -1} for thermal neutrons, (9{+-}3) 10{sup 2} tracks cm{sup -2} mSV{sup -1} for intermediate neutrons and (26{+-}4) tracks cm{sup -2} mSv{sup -1} for fast neutrons. The lower and upper limits of detection were respectively 0,002 mSv and 0,6 mSv for thermal neutrons, 0,04 mSv and 8 mSv for intermediate neutrons and 1 mSv and 12 mSv for fast neutrons. In view of the 1990`s ICRP recommendations, it is possible to conclude that the personal dosemeter described in this work is

  15. Are the American Psychological Association's Detainee Interrogation Policies Ethical and Effective?: Key Claims, Documents, and Results.

    Science.gov (United States)

    Pope, Kenneth S

    2011-01-01

    After 9-11, the United States began interrogating detainees at settings such as Abu Ghraib, Bagram, and Guantanamo. The American Psychological Association (APA) supported psychologists' involvement in interrogations, adopted formal policies, and made an array of public assurances. This article's purpose is to highlight key APA decisions, policies, procedures, documents, and public statements in urgent need of rethinking and to suggest questions that may be useful in a serious assessment, such as, "However well intended, were APA's interrogation policies ethically sound?"; "Were they valid, realistic, and able to achieve their purpose?"; "Were other approaches available that would address interrogation issues more directly, comprehensively, and actively, that were more ethically and scientifically based, and that would have had a greater likelihood of success?"; and "Should APA continue to endorse its post-9-11 detainee interrogation policies?"

  16. Are the American Psychological Association’s Detainee Interrogation Policies Ethical and Effective?

    Science.gov (United States)

    Pope, Kenneth S.

    2011-01-01

    After 9–11, the United States began interrogating detainees at settings such as Abu Ghraib, Bagram, and Guantanamo. The American Psychological Association (APA) supported psychologists’ involvement in interrogations, adopted formal policies, and made an array of public assurances. This article’s purpose is to highlight key APA decisions, policies, procedures, documents, and public statements in urgent need of rethinking and to suggest questions that may be useful in a serious assessment, such as, “However well intended, were APA’s interrogation policies ethically sound?”; “Were they valid, realistic, and able to achieve their purpose?”; “Were other approaches available that would address interrogation issues more directly, comprehensively, and actively, that were more ethically and scientifically based, and that would have had a greater likelihood of success?”; and “Should APA continue to endorse its post-9–11 detainee interrogation policies?” PMID:22096660

  17. On velocity space interrogation regions of fast-ion collective Thomson scattering at ITER

    DEFF Research Database (Denmark)

    Salewski, Mirko; Nielsen, Stefan Kragh; Bindslev, Henrik

    2011-01-01

    the collective scattering in well-defined regions in velocity space, here dubbed interrogation regions. Since the CTS instrument measures entire spectra of scattered radiation, many different interrogation regions are probed simultaneously. We here give analytic expressions for weight functions describing...... the interrogation regions, and we show typical interrogation regions of the proposed ITER CTS system. The backscattering system with receivers on the low-field side is sensitive to fast ions with pitch |p| = |v/v| ... scattering system with receivers on the high-field side would be sensitive to co- and counter-passing fast ions in narrow interrogation regions with pitch |p| > 0.6–0.8. Additionally, we use weight functions to reconstruct 2D fast-ion distribution functions, given two projected 1D velocity distribution...

  18. Lies and coercion: why psychiatrists should not participate in police and intelligence interrogations.

    Science.gov (United States)

    Janofsky, Jeffrey S

    2006-01-01

    Police interrogators routinely use deceptive techniques to obtain confessions from criminal suspects. The United States Executive Branch has attempted to justify coercive interrogation techniques in which physical or mental pain and suffering may be used during intelligence interrogations of persons labeled unlawful combatants. It may be appropriate for law enforcement, military, or intelligence personnel who are not physicians to use such techniques. However, forensic psychiatry ethical practice requires honesty, striving for objectivity, and respect for persons. Deceptive and coercive interrogation techniques violate these moral values. When a psychiatrist directly uses, works with others who use, or trains others to use deceptive or coercive techniques to obtain information in police, military, or intelligence interrogations, the psychiatrist breaches basic principles of ethics.

  19. Neutronic reactor

    International Nuclear Information System (INIS)

    Wende, C.W.J.

    1976-01-01

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield

  20. Neutron polarization

    International Nuclear Information System (INIS)

    Firk, F.W.K.

    1976-01-01

    Some recent experiments involving polarized neutrons are discussed; they demonstrate how polarization studies provide information on fundamental aspects of nuclear structure that cannot be obtained from more traditional neutron studies. Until recently, neutron polarization studies tended to be limited either to very low energies or to restricted regions at higher energies, determined by the kinematics of favorable (p, vector n) and (d, vector n) reactions. With the advent of high intensity pulsed electron and proton accelerators and of beams of vector polarized deuterons, this is no longer the case. One has entered an era in which neutron polarization experiments are now being carried out, in a routine way, throughout the entire range from thermal energies to tens-of-MeV. The significance of neutron polarization studies is illustrated in discussions of a wide variety of experiments that include the measurement of T-invariance in the β-decay of polarized neutrons, a search for the effects of meson exchange currents in the photo-disintegration of the deuteron, the determination of quantum numbers of states in the fission of aligned 235 U and 237 Np induced by polarized neutrons, and the double- and triple-scattering of fast neutrons by light nuclei

  1. Neutron holography

    International Nuclear Information System (INIS)

    Beynon, T.D.

    1986-01-01

    the paper concerns neutron holography, which allows an image to be constructed of the surfaces, as well as the interiors, of objects. The technique of neutron holography and its applications are described. Present and future use of the method is briefly outlined. (U.K.)

  2. Utilization of the Differential Die-Away Self-Interrogation Technique for Characterization and Verification of Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Trahan, Alexis Chanel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-27

    New nondestructive assay techniques are sought to better characterize spent nuclear fuel. One of the NDA instruments selected for possible deployment is differential die-away self-interrogation (DDSI). The proposed DDSI approach for spent fuel assembly assay utilizes primarily the spontaneous fission and (α, n) neutrons in the assemblies as an internal interrogating radiation source. The neutrons released in spontaneous fission or (α,n) reactions are thermalized in the surrounding water and induce fission in fissile isotopes, thereby creating a measurable signal from isotopes of interest that would be otherwise difficult to measure. The DDSI instrument employs neutron coincidence counting with 3He tubes and list-mode-based data acquisition to allow for production of Rossi-alpha distributions (RADs) in post-processing. The list-mode approach to data collection and subsequent construction of RADs has expanded the analytical possibilities, as will be demonstrated throughout this thesis. One of the primary advantages is that the measured signal in the form of a RAD can be analyzed in its entirety including determination of die-away times in different time domains. This capability led to the development of the early die-away method, a novel leakage multiplication determination method which is tested throughout the thesis on different sources in simulation space and fresh fuel experiments. The early die-away method is a robust, accurate, improved method of determining multiplication without the need for knowledge of the (α,n) source term. The DDSI technique and instrument are presented along with the many novel capabilities enabled by and discovered through RAD analysis. Among the new capabilities presented are the early die-away method, total plutonium content determination, and highly sensitive missing pin detection. Simulation of hundreds of different spent and fresh fuel assemblies were used to develop the analysis algorithms and the techniques were tested on a

  3. A pilot study of implantable cardiac device interrogation by emergency department personnel.

    Science.gov (United States)

    Neuenschwander, James F; Hiestand, Brian C; Peacock, W Frank; Billings, John M; Sondrup, Cole; Hummel, John D; Abraham, William T

    2014-03-01

    Implanted devices (eg, pacemakers and defibrillators) provide valuable information and may be interrogated to obtain diagnostic information and to direct management. During admission to an emergency department (ED), significant time and cost are spent waiting for device manufacturer representatives or cardiologists to access the data. If ED personnel could safely interrogate implanted devices, more rapid disposition could occur, thus leading to potentially better outcomes at a reduced cost. This was a pilot study examining the feasibility of ED device interrogation. This was a prospective convenience sample study of patients presenting to the ED with any chief complaint and who had an implantable device capable of being interrogated by a Medtronic reader. After obtaining informed consent, study patients underwent device interrogation by ED research personnel. After reviewing the device data, the physician documented their opinions of the value of data in aiding care. Patients were followed up at intervals ranging from 30 days out to 1 year to determine adverse events relating to interrogation. Forty-four patients underwent device interrogation. Their mean age was 56 ± 14.7 years (range, 28-83), 75% (33/44) were male and 75% (33/44) were hospitalized from the ED. The interrogations took less than 10 minutes 89% of the time. In 60% of the cases, ED physicians reported the data-assisted patient care. No adverse events were reported relating to the ED interrogations. In this pilot study, we found that ED personnel can safely and quickly interrogate implantable devices to obtain potentially useful clinical data.

  4. Neutron source

    International Nuclear Information System (INIS)

    Cason, J.L. Jr.; Shaw, C.B.

    1975-01-01

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap

  5. Neutron transport

    International Nuclear Information System (INIS)

    Berthoud, Georges; Ducros, Gerard; Feron, Damien; Guerin, Yannick; Latge, Christian; Limoge, Yves; Santarini, Gerard; Seiler, Jean-Marie; Vernaz, Etienne; Coste-Delclaux, Mireille; M'Backe Diop, Cheikh; Nicolas, Anne; Andrieux, Catherine; Archier, Pascal; Baudron, Anne-Marie; Bernard, David; Biaise, Patrick; Blanc-Tranchant, Patrick; Bonin, Bernard; Bouland, Olivier; Bourganel, Stephane; Calvin, Christophe; Chiron, Maurice; Damian, Frederic; Dumonteil, Eric; Fausser, Clement; Fougeras, Philippe; Gabriel, Franck; Gagnier, Emmanuel; Gallo, Daniele; Hudelot, Jean-Pascal; Hugot, Francois-Xavier; Dat Huynh, Tan; Jouanne, Cedric; Lautard, Jean-Jacques; Laye, Frederic; Lee, Yi-Kang; Lenain, Richard; Leray, Sylvie; Litaize, Olivier; Magnaud, Christine; Malvagi, Fausto; Mijuin, Dominique; Mounier, Claude; Naury, Sylvie; Nicolas, Anne; Noguere, Gilles; Palau, Jean-Marc; Le Pallec, Jean-Charles; Peneliau, Yannick; Petit, Odile; Poinot-Salanon, Christine; Raepsaet, Xavier; Reuss, Paul; Richebois, Edwige; Roque, Benedicte; Royer, Eric; Saint-Jean, Cyrille de; Santamarina, Alain; Serot, Olivier; Soldevila, Michel; Tommasi, Jean; Trama, Jean-Christophe; Tsilanizara, Aime; Behar, Christophe; Provitina, Olivier; Lecomte, Michael; Forestier, Alain; Bender, Alexandra; Parisot, Jean-Francois; Finot, Pierre

    2013-10-01

    This bibliographical note presents a reference book which addresses the study of neutron transport in matter, the study of conditions for a chain reaction and the study of modifications of matter composition due to nuclear reactions. This book presents the main nuclear data, their measurement, assessment and processing, and the spallation. It proposes an overview of methods applied for the study of neutron transport: basic equations and their derived forms, deterministic methods and Monte Carlo method of resolution of the Boltzmann equation, methods of resolution of generalized Bateman equations, methods of time resolution of space kinetics coupled equations. It presents the main calculation codes, discusses the qualification and experimental aspects, and gives an overview of neutron transport applications: neutron transport calculation of reactors, neutron transport coupled with other disciplines, physics of fuel cycle, criticality

  6. Influence of triaxiality on the signature inversion in odd-odd nuclei

    International Nuclear Information System (INIS)

    Zheng Renrong; Zhu Shunquan; Luo Xiangdong; Gizon, A.; Gizon, J.; Paul, E.S.

    2004-01-01

    The nature of signature inversion in the πg 9/2 νh 11/2 bands of odd-odd 98,102 Rh nuclei is studied. Calculations are performed by using a triaxial rotor plus two-quasiparticle model and are compared with the experimentally observed signature inversions. The calculations reproduce well the observations and suggest that, in these bands, the signature inversion can be interpreted mainly as a competition between the Coriolis and the proton-neutron residual interactions in low K space. The triaxiality applied in the Hamiltonian enlarges the amplitudes of high spin signature zigzags at small triaxial deformation and might push the signature inversion point to higher spin at large triaxial deformation

  7. Signatures of Mechanosensitive Gating.

    Science.gov (United States)

    Morris, Richard G

    2017-01-10

    The question of how mechanically gated membrane channels open and close is notoriously difficult to address, especially if the protein structure is not available. This perspective highlights the relevance of micropipette-aspirated single-particle tracking-used to obtain a channel's diffusion coefficient, D, as a function of applied membrane tension, σ-as an indirect assay for determining functional behavior in mechanosensitive channels. While ensuring that the protein remains integral to the membrane, such methods can be used to identify not only the gating mechanism of a protein, but also associated physical moduli, such as torsional and dilational rigidity, which correspond to the protein's effective shape change. As an example, three distinct D-versus-σ "signatures" are calculated, corresponding to gating by dilation, gating by tilt, and gating by a combination of both dilation and tilt. Both advantages and disadvantages of the approach are discussed. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  8. Research opportunities with compact accelerator-driven neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, I.S. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Andreani, C., E-mail: carla.andreani@uniroma2.it [Università degli Studi di Roma “Tor Vergata”, Physics Department and NAST Centre, Via della Ricerca Scientifica 1, 00133 Roma (Italy); CNR-IPCF Sezione di Messina, Messina (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma (Italy); Carpenter, J.M. [Argonne National Laboratory, Argonne, IL (United States); Festa, G., E-mail: giulia.festa@uniroma2.it [Università degli Studi di Roma “Tor Vergata”, Physics Department and NAST Centre, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma (Italy); Gorini, G. [Università degli Studi di Milano—Bicocca, Milano (Italy); Loong, C.-K. [Università degli Studi di Roma “Tor Vergata”, Centro NAST, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Senesi, R. [Università degli Studi di Roma “Tor Vergata”, Physics Department and NAST Centre, Via della Ricerca Scientifica 1, 00133 Roma (Italy); CNR-IPCF Sezione di Messina, Messina (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma (Italy)

    2016-10-13

    Since the discovery of the neutron in 1932 neutron beams have been used in a very broad range of applications, As an aging fleet of nuclear reactor sources is retired the use of compact accelerator-driven neutron sources (CANS) is becoming more prevalent. CANS are playing a significant and expanding role in research and development in science and engineering, as well as in education and training. In the realm of multidisciplinary applications, CANS offer opportunities over a wide range of technical utilization, from interrogation of civil structures to medical therapy to cultural heritage study. This paper aims to provide the first comprehensive overview of the history, current status of operation, and ongoing development of CANS worldwide. The basic physics and engineering regarding neutron production by accelerators, target–moderator systems, and beam line instrumentation are introduced, followed by an extensive discussion of various evolving applications currently exploited at CANS.

  9. Research opportunities with compact accelerator-driven neutron sources

    Science.gov (United States)

    Anderson, I. S.; Andreani, C.; Carpenter, J. M.; Festa, G.; Gorini, G.; Loong, C.-K.; Senesi, R.

    2016-10-01

    Since the discovery of the neutron in 1932 neutron beams have been used in a very broad range of applications, As an aging fleet of nuclear reactor sources is retired the use of compact accelerator-driven neutron sources (CANS) is becoming more prevalent. CANS are playing a significant and expanding role in research and development in science and engineering, as well as in education and training. In the realm of multidisciplinary applications, CANS offer opportunities over a wide range of technical utilization, from interrogation of civil structures to medical therapy to cultural heritage study. This paper aims to provide the first comprehensive overview of the history, current status of operation, and ongoing development of CANS worldwide. The basic physics and engineering regarding neutron production by accelerators, target-moderator systems, and beam line instrumentation are introduced, followed by an extensive discussion of various evolving applications currently exploited at CANS.

  10. Research opportunities with compact accelerator-driven neutron sources

    International Nuclear Information System (INIS)

    Anderson, I.S.; Andreani, C.; Carpenter, J.M.; Festa, G.; Gorini, G.; Loong, C.-K.; Senesi, R.

    2016-01-01

    Since the discovery of the neutron in 1932 neutron beams have been used in a very broad range of applications, As an aging fleet of nuclear reactor sources is retired the use of compact accelerator-driven neutron sources (CANS) is becoming more prevalent. CANS are playing a significant and expanding role in research and development in science and engineering, as well as in education and training. In the realm of multidisciplinary applications, CANS offer opportunities over a wide range of technical utilization, from interrogation of civil structures to medical therapy to cultural heritage study. This paper aims to provide the first comprehensive overview of the history, current status of operation, and ongoing development of CANS worldwide. The basic physics and engineering regarding neutron production by accelerators, target–moderator systems, and beam line instrumentation are introduced, followed by an extensive discussion of various evolving applications currently exploited at CANS.

  11. Signatures de l'invisible

    CERN Multimedia

    CERN Press Office. Geneva

    2000-01-01

    "Signatures of the Invisible" is an unique collaboration between contemporary artists and contemporary physicists which has the potential to help redefine the relationship between science and art. "Signatures of the Invisible" is jointly organised by the London Institute - the world's largest college of art and design and CERN*, the world's leading particle physics laboratory. 12 leading visual artists:

  12. An interpretation of signature inversion

    International Nuclear Information System (INIS)

    Onishi, Naoki; Tajima, Naoki

    1988-01-01

    An interpretation in terms of the cranking model is presented to explain why signature inversion occurs for positive γ of the axially asymmetric deformation parameter and emerges into specific orbitals. By introducing a continuous variable, the eigenvalue equation can be reduced to a one dimensional Schroedinger equation by means of which one can easily understand the cause of signature inversion. (author)

  13. Cell short circuit, preshort signature

    Science.gov (United States)

    Lurie, C.

    1980-01-01

    Short-circuit events observed in ground test simulations of DSCS-3 battery in-orbit operations are analyzed. Voltage signatures appearing in the data preceding the short-circuit event are evaluated. The ground test simulation is briefly described along with performance during reconditioning discharges. Results suggest that a characteristic signature develops prior to a shorting event.

  14. Ship Signature Management System : Functionality

    NARCIS (Netherlands)

    Arciszewski, H.F.R.; Lier, L. van; Meijer, Y.G.S.; Noordkamp, H.W.; Wassenaar, A.S.

    2010-01-01

    A signature of a platform is the manner in which the platform manifests itself to a certain type of sensor and how observable it is when such a sensor is used to detect the platform. Because many military platforms use sensors in different media, it is the total of its different signatures that

  15. A Point Kinetics Model for Estimating Neutron Multiplication of Bare Uranium Metal in Tagged Neutron Measurements

    International Nuclear Information System (INIS)

    Tweardy, Matthew C.; McConchie, Seth; Hayward, Jason P.

    2017-01-01

    An extension of the point kinetics model is developed in this paper to describe the neutron multiplicity response of a bare uranium object under interrogation by an associated particle imaging deuterium-tritium (D-T) measurement system. This extended model is used to estimate the total neutron multiplication of the uranium. Both MCNPX-PoliMi simulations and data from active interrogation measurements of highly enriched and depleted uranium geometries are used to evaluate the potential of this method and to identify the sources of systematic error. The detection efficiency correction for measured coincidence response is identified as a large source of systematic error. If the detection process is not considered, results suggest that the method can estimate total multiplication to within 13% of the simulated value. Values for multiplicity constants in the point kinetics equations are sensitive to enrichment due to (n, xn) interactions by D-T neutrons and can introduce another significant source of systematic bias. This can theoretically be corrected if isotopic composition is known a priori. Finally, the spatial dependence of multiplication is also suspected of introducing further systematic bias for high multiplication uranium objects.

  16. A Point Kinetics Model for Estimating Neutron Multiplication of Bare Uranium Metal in Tagged Neutron Measurements

    Science.gov (United States)

    Tweardy, Matthew C.; McConchie, Seth; Hayward, Jason P.

    2017-07-01

    An extension of the point kinetics model is developed to describe the neutron multiplicity response of a bare uranium object under interrogation by an associated particle imaging deuterium-tritium (D-T) measurement system. This extended model is used to estimate the total neutron multiplication of the uranium. Both MCNPX-PoliMi simulations and data from active interrogation measurements of highly enriched and depleted uranium geometries are used to evaluate the potential of this method and to identify the sources of systematic error. The detection efficiency correction for measured coincidence response is identified as a large source of systematic error. If the detection process is not considered, results suggest that the method can estimate total multiplication to within 13% of the simulated value. Values for multiplicity constants in the point kinetics equations are sensitive to enrichment due to (n, xn) interactions by D-T neutrons and can introduce another significant source of systematic bias. This can theoretically be corrected if isotopic composition is known a priori. The spatial dependence of multiplication is also suspected of introducing further systematic bias for high multiplication uranium objects.

  17. Neutron therapy

    International Nuclear Information System (INIS)

    Riesler, Rudi

    1995-01-01

    Standard radiotherapy uses Xrays or electrons which have low LET (linear energy transfer); in contrast, particles such as neutrons with high LET have different radiobiological responses. In the late 1960s, clinical trials by Mary Catterall at the Hammersmith Hospital in London indicated that fast neutron radiation had clinical advantages for certain malignant tumours. Following these early clinical trials, several cyclotron facilities were built in the 1980s for fast neutron therapy, for example at the University of Washington, Seattle, and at UCLA. Most of these newer machines use extracted cyclotron proton beams in the range 42 to 66 MeV with beam intensities of 15 to 60 microamps. The proton beams are transported to dedicated therapy rooms, where neutrons are produced from beryllium targets. Second-generation clinical trials showed that accurate neutron beam delivery to the tumour site is more critical than for photon therapy. In order to achieve precise beam geometries, the extracted proton beams have to be transported through a gantry which can rotate around the patient and deliver beams from any angle; also the neutron beam outline (''field shape'') must be adjusted to extremely irregular shapes using a flexible collimation system. A therapy procedure has to be appropriately organized, with physicians, radiotherapists, nurses, medical physicists and other staff in attendance; other specialized equipment, such as CT or MRI scanners and radiation simulators must be made available. Neutron therapy is usually performed only in radiation oncology departments of major medical centres

  18. Assay of low-enriched uranium using spontaneous fission neutrons

    International Nuclear Information System (INIS)

    Zucker, M.S.; Fainberg, A.

    1980-01-01

    Low-enriched uranium oxide in bulk containers can be assayed for safeguards purposes, using the neutrons from spontaneous fission of 238 U as a signature, to complement enrichment and mass measurement. The penetrability of the fast fission neutrons allows the inner portion of bulk samples to register. The measurement may also be useful for measuring moisture content, of significance in process control. The apparatus used can be the same as for neutron correlation counting for Pu assay. The neutron multiplication observed in 238 U is of intrinsic interest

  19. Measurement of actinide neutron cross sections

    International Nuclear Information System (INIS)

    Firestone, Richard B.; Nitsche, Heino; Leung, Ka-Ngo; Perry, DaleL.; English, Gerald

    2003-01-01

    The maintenance of strong scientific expertise is critical to the U.S. nuclear attribution community. It is particularly important to train students in actinide chemistry and physics. Neutron cross-section data are vital components to strategies for detecting explosives and fissile materials, and these measurements require expertise in chemical separations, actinide target preparation, nuclear spectroscopy, and analytical chemistry. At the University of California, Berkeley and the Lawrence Berkeley National Laboratory we have trained students in actinide chemistry for many years. LBNL is a leader in nuclear data and has published the Table of Isotopes for over 60 years. Recently, LBNL led an international collaboration to measure thermal neutron capture radiative cross sections and prepared the Evaluated Gamma-ray Activation File (EGAF) in collaboration with the IAEA. This file of 35, 000 prompt and delayed gamma ray cross-sections for all elements from Z=1-92 is essential for the neutron interrogation of nuclear materials. LBNL has also developed new, high flux neutron generators and recently opened a 1010 n/s D+D neutron generator experimental facility

  20. Neutron radiography

    International Nuclear Information System (INIS)

    Alaa eldin, M.T.

    2011-01-01

    The digital processing of the neutron radiography images gives the possibility for data quantification. In this case an exact relation between the measured neutron attenuation and the real macroscopic attenuation coefficient for every point of the sample is required. The assumption that the attenuation of the neutron beam through the sample is exponential is valid only in an ideal case where a monochromatic beam, non scattering sample and non background contribution are assumed. In the real case these conditions are not fulfilled and in dependence on the sample material we have more or less deviation from the exponential attenuation law. Because of the high scattering cross-sections of hydrogen (σs=80.26 barn) for thermal neutrons, the problem with the scattered neutrons at quantitative radiography investigations of hydrogenous materials (as PE, Oil, H 2 O, etc) is not trivial. For these strong scattering materials the neutron beam attenuation is no longer exponential and a dependence of the macroscopic attenuation coefficient on the material thickness and on the distance between the sample and the detector appears. When quantitative radiography (2 D) or tomography investigations (3 D) are performed, some image correction procedures for a description of the scattering effect are required. This thesis presents a method that can be used to enhance the neutron radiography image for objects with high scattering materials like hydrogen, carbon and other light materials. This method uses the Monte Carlo code, MCNP5, to simulate the neutron radiography process and get the flux distribution for each pixel of the image and determine the scattered neutrons distribution that causes the image blur and then subtract it from the initial image to improve its quality.

  1. Neutronics codes

    International Nuclear Information System (INIS)

    Buckel, G.

    1983-01-01

    The objectives are the development, testing and cultivation of reliable, efficient and user-optimized neutron-physical calculation methods and conformity with users' requirements concerning design of power reactors, planning and analysis of experiments necessary for their protection as well as research on physical key problems. A short outline of available computing programmes for the following objectives is given: - Provision of macroscopic group constants, - Calculation of neutron flux distribution in transport theory and diffusion approximation, - Evaluation of neutron flux-distribution, - Execution of disturbance calculations for the determination reactivity coefficients, and - graphical representation of results. (orig./RW) [de

  2. Radioisotopes produced by neutron irradiation of food.

    Science.gov (United States)

    Albright, S; Seviour, R

    2016-04-01

    The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of (24)Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total activity and the ingestion dose we show that a variety of isotopes contribute and that (24)Na is only dominant under certain conditions. The composition of the foods has a strong influence on the resulting activity and ingestion dose suggesting that the pharmaceuticals and medical devices considered initially are not a viable analogue for foodstuffs. There is an energy dependence to the isotopes produced due to the cross-sections of different reactions varying with neutron energy. We show that this results in different isotopes dominating the ingestion dose at different energies, which has not been considered in the previous literature. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Development of SiC Neutron Detector Assembly to Measure the Neutron Flux of the Reactor Core

    Energy Technology Data Exchange (ETDEWEB)

    Park, Se Hwan; Park, June Sic; Shin, Hee Sung; Kim, Ho Dong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Yong Kyun [Hanyang University, Seoul (Korea, Republic of)

    2012-05-15

    At present, the conventional detector to measure the neutron at harsh environment is a Self Powered Neutron Detector (SPND). Rhodium(Rh)-103 is in the SPND. When neutron is incident on the Rhodium, the neutron capture reaction occurs, and the Rh-103 is converted to Rh-104. The Rh-104 is decayed to Pd-104 by {beta}-decay, and electrons are generated as the decay products. Because of the half life of Rh-104, approximately 5 minutes are required for the SPND output to reach the equilibrium condition. Therefore the on-line monitoring of the nuclear reactor state is limited if the neutron flux in the reactor core is monitored with the SPND. Silicon carbide (SiC) has the possibility to be developed as neutron detector at harsh environment, because the SiC can be operative at high temperature and high neutron flux conditions. Previously, the basic operation properties of the SiC detector were studied. Also, the radiation response of the SiC detector was studied at high neutron and gamma dose rate. The measurement results for an ex-core neutron flux monitor or a neutron flux monitor of the spent fuel were published. The SiC detector was also developed as neutron detector to measure the fissile material with active interrogation method. However, the studies about the development of SiC detector are still limited. In the present work, the radiation damage effect of the SiC detector was studied. The detector structure was determined based on the study, and a neutron detector assembly was made with the SiC detectors. The neutron and gamma-ray response of the detector assembly is presented in this paper. The detector assembly was positioned in the HANARO research reactor core, the performance test was done. The preliminary results are also included in this paper

  4. A SYSTEMATIC APPROACH TO THE PSYCHOLOGICAL IMPACT OF THE INVESTIGATOR ON A PERSON BEING INTERROGATED

    Directory of Open Access Journals (Sweden)

    Ivan Cherevko

    2017-03-01

    Full Text Available The subject of the research is an interaction with a person being interrogated organized by an investigator with the use of his interests, needs and other individual-mental features, his reinforcement, which must be done through secretive, invisible influence in an organized situation encouraging to do deeds desirable for investigation. The object of the research is interrogation as the most psychologized investigative action. The methodological basis of the research is made by the systematic and logical approach aimed at neutralization of watchfulness of the interrogated, penetration into his inner world influencing both rational and irrational spheres of mental make-up, actualization of the unity of understanding and experience. In this research general scientific and specific scientific methods of cognition are used. General scientific methods of the research are represented by systemic structural, comparative, formal and legal, statistical methods. The approach to the psychological impact on a person being interrogated as a systemic phenomenon has enabled to develop a conceptual model presented in the form of a diagram made up of four blocks reflecting emotional background sources of interrogation procedures, the interrogated case, interaction and basic methods of psychological influence, the leading of which is persuasion. Suggestion is purposeful influence on feelings and volitional pressure acts as pressure maintenance, complementary, used depending on the situational behaviour of the interrogated. Methods of implementation of each of these methods of psychological influence are also considered in this article.

  5. What do potential jurors know about police interrogation techniques and false confessions?

    Science.gov (United States)

    Leo, Richard A; Liu, Brittany

    2009-01-01

    Psychological police interrogation methods in America inevitably involve some level of pressure and persuasion to achieve their goal of eliciting confessions of guilt from custodial suspects. In this article, we surveyed potential jurors about their perceptions of a range of psychological interrogation techniques, the likelihood that such techniques would elicit a true confession from guilty suspects, and the likelihood that such techniques could elicit a false confession from innocent suspects. Participants recognized that these interrogation techniques may be psychologically coercive and may elicit true confessions, but believed that psychologically coercive interrogation techniques are not likely to elicit false confessions. The findings from this survey study indicate that potential jurors believe that false confessions are both counter- intuitive and unlikely, even in response to psychologically coercive interrogation techniques that have been shown to lead to false confessions from the innocent. This study provides empirical support for the idea that expert witnesses may helpfully inform jurors about the social science research on psychologically coercive interrogation methods and how and why such interrogation techniques can lead to false confessions. (c) 2009 John Wiley & Sons, Ltd.

  6. Neutron induced gamma spectrometry for on-line compositional analysis in coal conversion and fluidized-bed combustion plants

    International Nuclear Information System (INIS)

    Herzenberg, C.L.; O'Fallon, N.M.; Yarlagadda, B.S.; Doering, R.W.; Cohn, C.E.; Porges, K.G.; Duffey, D.

    1977-01-01

    Nuclear techniques involving relatively penetrating radiation may offer the possibility of non-invasive, continuous on-line instrumental monitoring which is representative of the full process stream. Prompt gamma rays following neutron capture are particularly attractive because the penetrating power of the neutrons and the, typically several MeV, capture gammas makes possible interrogation of material within a pipe. We are evaluating neutron capture gamma techniques for this application, both for elemental composition monitoring and for mass-flow measurement purposes, and this paper will present some recent work on composition analysis by neutron induced gamma spectrometry

  7. Neutron reflectometry

    DEFF Research Database (Denmark)

    Klösgen-Buchkremer, Beate Maria

    2014-01-01

    of desired information. In the course, an introduction into the method and an overview on selected instruments at large scale facilities will be presented. Examples will be given that illustrate the potential of the method, mostly based on organic films. Results from the investigation of layered films......Neutron (and X-ray) reflectometry constitute complementary interfacially sensitive techniques that open access to studying the structure within thin films of both soft and hard condensed matter. Film thickness starts oxide surfaces on bulk substrates, proceeding to (pauci-)molecular layers and up...... films or films with magnetic properties. The reason is the peculiar property of neutron light since the mass of a neutron is close to the one of a proton, and since it bears a magnetic moment. The optical properties of matter, when interacting with neutrons, are described by a refractive index...

  8. Neutron scattering

    International Nuclear Information System (INIS)

    Furrer, A.

    1993-01-01

    This report contains the text of 16 lectures given at the Summer School and the report on a panel discussion entitled ''the relative merits and complementarities of x-rays, synchrotron radiation, steady- and pulsed neutron sources''. figs., tabs., refs

  9. Design of Interrogation Protocols for Radiation Dose Measurements Using Optically-Stimulated Luminescent Dosimeters.

    Science.gov (United States)

    Abraham, Sara A; Kearfott, Kimberlee J; Jawad, Ali H; Boria, Andrew J; Buth, Tobias J; Dawson, Alexander S; Eng, Sheldon C; Frank, Samuel J; Green, Crystal A; Jacobs, Mitchell L; Liu, Kevin; Miklos, Joseph A; Nguyen, Hien; Rafique, Muhammad; Rucinski, Blake D; Smith, Travis; Tan, Yanliang

    2017-03-01

    Optically-stimulated luminescent dosimeters are capable of being interrogated multiple times post-irradiation. Each interrogation removes a fraction of the signal stored within the optically-stimulated luminescent dosimeter. This signal loss must be corrected to avoid systematic errors in estimating the average signal of a series of optically-stimulated luminescent dosimeter interrogations and requires a minimum number of consecutive readings to determine an average signal that is within a desired accuracy of the true signal with a desired statistical confidence. This paper establishes a technical basis for determining the required number of readings for a particular application of these dosimeters when using certain OSL dosimetry systems.

  10. Simulation of path delay multiplexing-based Fourier transform spectrometer for fiber Bragg grating interrogation.

    Science.gov (United States)

    Chelliah, Pandian; Sahoo, Trilochan; Singh, Sheela; Sujatha, Annie

    2015-10-20

    A Fourier transform spectrometer (FTS) used for interrogating a fiber Bragg grating (FBG) consists of a scanning-type interferometer. The FTS has a broad wavelength range of operation and good multiplexing capability. However, it has poor wavelength resolution and interrogation speed. We propose a modification to the FTS using path delay multiplexing to improve the same. Using this method, spatial resolution and interrogation time can be improved by n times by using n path delays. In this paper, simulation results for n=2, 5 are shown.

  11. Neutron storage

    International Nuclear Information System (INIS)

    Strelkov, A.V.

    2004-01-01

    The report is devoted to neutron storage (NS) and describes the history of experiments on the NS development. Great attention is paid to ultracold neutron (UCN) storage. The experiments on the UCN generation, transport, spectroscopy, storage and detection are described. Experiments on searching the UCN electric-dipole moment and electric charge are continued. Possible using of UCN for studying the nanoparticles is discussed [ru

  12. Neutron radiography

    International Nuclear Information System (INIS)

    Bayon, G.

    1989-01-01

    Neutronography or neutron radiography, a non-destructive test method which is similar in its principle to conventional X-ray photography, presently occupies a marginal position among non-destructive test methods (NDT) (no source of suitable performance or cost). Neutron radiography associated with the ORPHEE reactor permits industrial testing; it can very quickly meet a cost requirement comparable to that of conventional test methods. In 1988, 2500 parts were tested on this unit [fr

  13. Multiplicity Analysis during Photon Interrogation of Fissionable Material

    International Nuclear Information System (INIS)

    Clarke, Shaun D.; Pozzi, Sara A.; Padovani, Enrico; Downar, Thomas J.

    2007-01-01

    Simulation of multiplicity distributions with the Monte Carlo method is difficult because each history is treated individually. In order to accurately model the multiplicity distribution, the intensity and time width of the interrogation pulse must be incorporated into the calculation. This behavior dictates how many photons arrive at the target essentially simultaneously. In order to model the pulse width correctly, a Monte Carlo code system consisting of modified versions of the codes MCNPX and MCNP-PoliMi has been developed in conjunction with a post-processing algorithm to operate on the MCNP-PoliMi output file. The purpose of this subroutine is to assemble the interactions into groups corresponding to the number of interactions which would occur during a given pulse. The resulting multiplicity distributions appear more realistic and capture the higher-order multiplets which are a product of multiple reactions occurring during a single accelerator pulse. Plans are underway to gather relevant experimental data to verify and validate the methodology developed and presented here. This capability will enable the simulation of a large number of materials and detector geometries. Analysis of this information will determine the feasibility of using multiplicity distributions as an identification tool for special nuclear material.

  14. The synchronous active neutron detection system for spent fuel assay

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Kendall, P.K.

    1994-01-01

    The authors have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit the unique operating features of a 14-MeV neutron generator developed by Schlumberger. This generator and a novel detection system will be applied to the direct measurement of the fissile material content in spent fuel in place of the indirect measures used at present. The technique they are investigating is termed synchronous active neutron detection (SAND). It closely follows a method that has been used routinely in other branches of physics to detect very small signals in the presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed open-quotes lock-inclose quotes amplifiers. The authors have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. This approach is possible because the Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. The results to date are preliminary but quite promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly. It also appears to be quite resilient to background neutron interference. The interrogating neutrons appear to be nonthermal and penetrating. Although a significant amount of work remains to fully explore the relevant physics and optimize the instrument design, the underlying concept appears sound

  15. Neutron detector

    International Nuclear Information System (INIS)

    Endo, Hiroshi.

    1993-01-01

    The device of the present invention detects neutrons in a reactor container under a high temperature and reduces the noise level in an FBR type reactor. That is, the detection section comprises a high heat resistant vessel containing a scintillator therein for detecting neutrons. Neutron signals sent from the detection section are inputted to a neutron measuring section by way of a signal transmission section. The detection section is disposed at the inside of the reactor container. Further, the signal transmission section is connected optically to the detection section. With such a constitution, since the detection section comprising the high temperature resistant vessel is disposed at the inside of the reactor container, neutron fluxes can be detected and measured at high sensitivity even under a high temperature circumstance. Since the signal transmission section is optically connected to the detection section, influence of radiation rays upon transmission of the neutron detection signals can be reduced. Accordingly, the noise level can be kept low. (I.S.)

  16. Neutron Scattering

    International Nuclear Information System (INIS)

    Fayer, Michael J.; Gee, Glendon W.

    2005-01-01

    The neutron probe is a standard tool for measuring soil water content. This article provides an overview of the underlying theory, describes the methodology for its calibration and use, discusses example applications, and identifies the safety issues. Soil water makes land-based life possible by satisfying plant water requirements, serving as a medium for nutrient movement to plant roots and nutrient cycling, and controlling the fate and transport of contaminants in the soil environment. Therefore, a successful understanding of the dynamics of plant growth, nutrient cycling, and contaminant behavior in the soil requires knowledge of the soil water content as well as its spatial and temporal variability. After more than 50 years, neutron probes remain the most reliable tool available for field monitoring of soil water content. Neutron probes provide integrated measurements over relatively large volumes of soil and, with proper access, allow for repeated sampling of the subsurface at the same locations. The limitations of neutron probes include costly and time-consuming manual operation, lack of data automation, and costly regulatory requirements. As more non-radioactive systems for soil water monitoring are developed to provide automated profiling capabilities, neutron-probe usage will likely decrease. Until then, neutron probes will continue to be a standard for reliable measurements of field water contents in soils around the globe

  17. A gamma/neutron-discriminating, Cooled, Optically Stimulated Luminescence (COSL) dosemeter

    International Nuclear Information System (INIS)

    Eschbach, P.A.; Miller, S.D.

    1992-07-01

    The Cooled Optically Stimulated Luminescence (COSL) of CaF 2 :Mn (grain sizes from 0.1 to 100 microns) powder embedded in a hydrogenous matrix is reported as a function of fast-neutron dose. When all the CaF 2 :Mn grains are interrogated at once, the COSL plastic dosemeters have a minimum detectable limit of 1 cSv fast neutrons; the gamma component from the bare 252 cf exposure was determined with a separate dosemeter. We report here on a proton-recoil-based dosemeter that generates pulse height spectra, much like the scintillator of Hornyak, (2) to provide information on both the neutron and gamma dose

  18. Neutron-neutron probe for uranium exploration

    International Nuclear Information System (INIS)

    Smith, R.C.

    1979-01-01

    A neutron activation probe for assaying the amount of fissionable isotopes in an ore body is described which comprises a casing which is movable through a borehole in the ore body, a neutron source and a number of delayed neutron detectors arranged colinearly in the casing below the neutron source for detecting delayed neutrons

  19. CVD polycrystalline diamond. A novel neutron detector and applications

    International Nuclear Information System (INIS)

    Mongkolnavin, R.

    1998-01-01

    Chemical Vapour Deposition (CVD) Polycrystalline Diamond film has been investigated as a low noise sensor for beta particles, gammas and neutrons using High Energy Physics technologies. Its advantages and disadvantages have been explored in comparison with other particle detectors such as silicon detector and other plastic scintillators. The performance and characteristic of the diamond detector have been fully studied and discussed. These studies will lead to a better understanding of how CVD diamonds perform as a detector and how to improve their performance under various conditions. A CVD diamond detector model has been proposed which is an attempt to explain the behaviour of such an extreme detector material. A novel neutron detector is introduced as a result of these studies. A good thermal and fast neutron detector can be fabricated with CVD diamond with new topologies. This detector will perform well without degradation in a high neutron radiation environment, as diamond is known to be radiation hard. It also offers better neutrons and gammas discrimination for high gamma background applications compared to other semiconductor detectors. A full simulation of the detector has also been done using GEANT, a Monte-Carlo simulation program for particle detectors. Simulation results show that CVD diamond detectors with this novel topology can detect neutrons with great directionality. Experimental work has been done on this detector in a nuclear reactor environment and accelerator source. A novel neutron source which offers a fast pulse high-energy neutrons has also been studied. With this detector, applications in neutron spectrometer for low-Z material have been pursued with various neutron detection techniques. One of these is a low-Z material identification system. The system has been designed and simulated for contraband luggage interrogation using the detector and the novel neutron source. Also other neutron related applications have been suggested. (author)

  20. Interrogating the Spatiotemporal Landscape of Neuromodulatory GPCR Signaling by Real-Time Imaging of cAMP in Intact Neurons and Circuits

    Directory of Open Access Journals (Sweden)

    Brian S. Muntean

    2018-01-01

    Full Text Available Summary: Modulation of neuronal circuits is key to information processing in the brain. The majority of neuromodulators exert their effects by activating G-protein-coupled receptors (GPCRs that control the production of second messengers directly impacting cellular physiology. How numerous GPCRs integrate neuromodulatory inputs while accommodating diversity of incoming signals is poorly understood. In this study, we develop an in vivo tool and analytical suite for analyzing GPCR responses by monitoring the dynamics of a key second messenger, cyclic AMP (cAMP, with excellent quantitative and spatiotemporal resolution in various neurons. Using this imaging approach in combination with CRISPR/Cas9 editing and optogenetics, we interrogate neuromodulatory mechanisms of defined populations of neurons in an intact mesolimbic reward circuit and describe how individual inputs generate discrete second-messenger signatures in a cell- and receptor-specific fashion. This offers a resource for studying native neuronal GPCR signaling in real time. : Muntean et al. develop an in vivo reagent to study processing of neurotransmitter GPCR signals by monitoring real-time dynamics of cAMP responses. They demonstrate application of this approach, in combination with CRISPR/Cas9 gene editing and optogenetics, to interrogate the functional organization of a striatal circuit. Keywords: cAMP, GPCR, neuromodulation, dopamine, striatum, imaging, optogenetics

  1. Promotion COPERNIC Energy and Society the interrogations on the world demand evolution; Promotion COPERNIC Energie et Societe les interrogations sur l'evolution de la demande mondiale

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-15

    In the framework of a prospective reflexion emergence on the energy demand, this document presents an analysis of the prospective approach and of recent studies: challenges, interests, limits, validity of the models and hypothesis and results relevance. With this analysis, the authors aim to identify the main interrogations bond to the world energy demand evolution. They then analyse these interrogations in the framework of a sectoral approach (agriculture, industry, transports, residential) in order to detail the demand and to forecast the evolution. Facing the consumption attitudes, they also suggest some new action avenues to favor a sustainable growth. (A.L.B.)

  2. Promotion COPERNIC Energy and Society the interrogations on the world demand evolution; Promotion COPERNIC Energie et Societe les interrogations sur l'evolution de la demande mondiale

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-15

    In the framework of a prospective reflexion emergence on the energy demand, this document presents an analysis of the prospective approach and of recent studies: challenges, interests, limits, validity of the models and hypothesis and results relevance. With this analysis, the authors aim to identify the main interrogations bond to the world energy demand evolution. They then analyse these interrogations in the framework of a sectoral approach (agriculture, industry, transports, residential) in order to detail the demand and to forecast the evolution. Facing the consumption attitudes, they also suggest some new action avenues to favor a sustainable growth. (A.L.B.)

  3. The phase interrogation method for optical fiber sensor by analyzing the fork interference pattern

    Science.gov (United States)

    Lv, Riqing; Qiu, Liqiang; Hu, Haifeng; Meng, Lu; Zhang, Yong

    2018-02-01

    The phase interrogation method for optical fiber sensor is proposed based on the fork interference pattern between the orbital angular momentum beam and plane wave. The variation of interference pattern with phase difference between the two light beams is investigated to realize the phase interrogation. By employing principal component analysis method, the features of the interference pattern can be extracted. Moreover, the experimental system is designed to verify the theoretical analysis, as well as feasibility of phase interrogation. In this work, the Mach-Zehnder interferometer was employed to convert the strain applied on sensing fiber to the phase difference between the reference and measuring paths. This interrogation method is also applicable for the measurements of other physical parameters, which can produce the phase delay in optical fiber. The performance of the system can be further improved by employing highlysensitive materials and fiber structures.

  4. Low-Cost Interrogation Technique for Dynamic Measurements with FBG-Based Devices.

    Science.gov (United States)

    Díaz, Camilo A R; Leitão, Cátia; Marques, Carlos A; Domingues, M Fátima; Alberto, Nélia; Pontes, Maria José; Frizera, Anselmo; Ribeiro, Moisés R N; André, Paulo S B; Antunes, Paulo F C

    2017-10-23

    Fiber Bragg gratings are widely used optical fiber sensors for measuring temperature and/or mechanical strain. Nevertheless, the high cost of the interrogation systems is the most important drawback for their large commercial application. In this work, an in-line Fabry-Perot interferometer based edge filter is explored in the interrogation of fiber Bragg grating dynamic measurements up to 5 kHz. Two devices an accelerometer and an arterial pulse wave probe were interrogated with the developed approach and the results were compared with a commercial interrogation monitor. The data obtained with the edge filter are in agreement with the commercial device, with a maximum RMSE of 0.05 being able to meet the requirements of the measurements. Resolutions of 3.6 pm and 2.4 pm were obtained, using the optical accelerometer and the arterial pulse wave probe, respectively.

  5. Pulsed THZ Interrogation of Sofi With Knit Lines in 2D

    National Research Council Canada - National Science Library

    Banks, H. T; Gibson, N. L; Winfree, W. P

    2006-01-01

    This paper examines the scattering effect of knit lines and voids in SOFI through simulations of THz interrogation at normal and non-normal angles of incidence and using focused and non-focused single-cycle plane waves...

  6. The History of MIS-Y: U.S. Strategic Interrogation During World War II

    National Research Council Canada - National Science Library

    Kleinman, Steven M

    2002-01-01

    As World War II unfolded, the strategic interrogation programs established by the British, German, and American forces evolved into robust collection entities that proved to be a unique source of critical intelligence...

  7. Adaptive image interrogation for PIV : Application to compressible flows and interfaces

    NARCIS (Netherlands)

    Theunissen, R.

    2010-01-01

    As an experimental tool, Particle Image Velocimetry has quickly superseded traditional point-wise measurements. The inherent image processing has become standardized though the performances are strongly dependent on user experience. Moreover, the arduously selected image interrogation parameters are

  8. Initial Semantics for Strengthened Signatures

    Directory of Open Access Journals (Sweden)

    André Hirschowitz

    2012-02-01

    Full Text Available We give a new general definition of arity, yielding the companion notions of signature and associated syntax. This setting is modular in the sense requested by Ghani and Uustalu: merging two extensions of syntax corresponds to building an amalgamated sum. These signatures are too general in the sense that we are not able to prove the existence of an associated syntax in this general context. So we have to select arities and signatures for which there exists the desired initial monad. For this, we follow a track opened by Matthes and Uustalu: we introduce a notion of strengthened arity and prove that the corresponding signatures have initial semantics (i.e. associated syntax. Our strengthened arities admit colimits, which allows the treatment of the λ-calculus with explicit substitution.

  9. Retail applications of signature verification

    Science.gov (United States)

    Zimmerman, Thomas G.; Russell, Gregory F.; Heilper, Andre; Smith, Barton A.; Hu, Jianying; Markman, Dmitry; Graham, Jon E.; Drews, Clemens

    2004-08-01

    The dramatic rise in identity theft, the ever pressing need to provide convenience in checkout services to attract and retain loyal customers, and the growing use of multi-function signature captures devices in the retail sector provides favorable conditions for the deployment of dynamic signature verification (DSV) in retail settings. We report on the development of a DSV system to meet the needs of the retail sector. We currently have a database of approximately 10,000 signatures collected from 600 subjects and forgers. Previous work at IBM on DSV has been merged and extended to achieve robust performance on pen position data available from commercial point of sale hardware, achieving equal error rates on skilled forgeries and authentic signatures of 1.5% to 4%.

  10. Magnetic Signature Analysis & Validation System

    National Research Council Canada - National Science Library

    Vliet, Scott

    2001-01-01

    The Magnetic Signature Analysis and Validation (MAGSAV) System is a mobile platform that is used to measure, record, and analyze the perturbations to the earth's ambient magnetic field caused by object such as armored vehicles...

  11. Illicit substance detection using fast-neutron transmission spectroscopy

    International Nuclear Information System (INIS)

    Micklich, B.J.; Harper, M.K.; Novick, A.H.; Smith, D.L.

    1994-01-01

    Fast-neutron interrogation techniques are of interest for detecting illicit substances such as explosives and drugs because of their ability to identify light elements such as carbon, nitrogen, and oxygen. Fast-Neutron Transmission Spectroscopy (FNTS) uses standard time-of-flight techniques to measure the energy spectrum of neutrons emitted from a collimated continuum source before and after transmission through the interrogated sample. The Monte Carlo transport code MCNP is used to model fast-neutron transmission experiments using a 9 Be(d, n) source (E d =5 MeV). The areal densities (number of atoms per cm 2 ), and the uncertainties, of various elements present in the sample are determined by an unfolding algorithm which includes the effects of cross-section errors and correlations. Results are displayed in the form of normalized densities, including their errors and correlations, which are then compared to the values for explosives and benign substances. Probabilistic interpretations of the results are discussed in terms of substance detection and identification. ((orig.))

  12. Illicit substance detection using Fast-Neutron Transmission Spectroscopy

    International Nuclear Information System (INIS)

    Micklich, B.J.; Harper, M.K.; Novick, A.H.; Smith, D.L.

    1994-01-01

    Fast-neutron interrogation techniques are of interest for detecting illicit substances such as explosives and drugs because of their ability to identify light elements such as carbon, nitrogen, and oxygen. Fast-Neutron Transmission Spectroscopy (FNTS) uses standard time-of-flight techniques to measure the energy spectrum of neutrons emitted from a collimated continuum source before and after transmission through the interrogated sample. The Monte Carlo transport code MCNP is used to model fast-neutron transmission experiments using a 9 Be(d,n) source [E d = 5 MeV]. The areal densities (number of atoms per cm 2 ), and the uncertainties, of various elements present in the sample are determined by an unfolding algorithm which includes the effects of cross-section errors and correlations. Results are displayed in the form of normalized densities, including their errors and correlations, which are then compared to the values for explosives and benign substances. Probabilistic interpretations of the results are discussed in terms of substance detection and identification

  13. Intelligence, previous convictions and interrogative suggestibility: a path analysis of alleged false-confession cases.

    Science.gov (United States)

    Sharrock, R; Gudjonsson, G H

    1993-05-01

    The main purpose of this study was to investigate the relationship between interrogative suggestibility and previous convictions among 108 defendants in criminal trials, using a path analysis technique. It was hypothesized that previous convictions, which may provide defendants with interrogative experiences, would correlate negatively with 'shift' as measured by the Gudjonsson Suggestibility Scale (Gudjonsson, 1984a), after intelligence and memory had been controlled for. The hypothesis was partially confirmed and the theoretical and practical implications of the findings are discussed.

  14. Interrogating the topological robustness of gene regulatory circuits by randomization.

    Directory of Open Access Journals (Sweden)

    Bin Huang

    2017-03-01

    Full Text Available One of the most important roles of cells is performing their cellular tasks properly for survival. Cells usually achieve robust functionality, for example, cell-fate decision-making and signal transduction, through multiple layers of regulation involving many genes. Despite the combinatorial complexity of gene regulation, its quantitative behavior has been typically studied on the basis of experimentally verified core gene regulatory circuitry, composed of a small set of important elements. It is still unclear how such a core circuit operates in the presence of many other regulatory molecules and in a crowded and noisy cellular environment. Here we report a new computational method, named random circuit perturbation (RACIPE, for interrogating the robust dynamical behavior of a gene regulatory circuit even without accurate measurements of circuit kinetic parameters. RACIPE generates an ensemble of random kinetic models corresponding to a fixed circuit topology, and utilizes statistical tools to identify generic properties of the circuit. By applying RACIPE to simple toggle-switch-like motifs, we observed that the stable states of all models converge to experimentally observed gene state clusters even when the parameters are strongly perturbed. RACIPE was further applied to a proposed 22-gene network of the Epithelial-to-Mesenchymal Transition (EMT, from which we identified four experimentally observed gene states, including the states that are associated with two different types of hybrid Epithelial/Mesenchymal phenotypes. Our results suggest that dynamics of a gene circuit is mainly determined by its topology, not by detailed circuit parameters. Our work provides a theoretical foundation for circuit-based systems biology modeling. We anticipate RACIPE to be a powerful tool to predict and decode circuit design principles in an unbiased manner, and to quantitatively evaluate the robustness and heterogeneity of gene expression.

  15. Epistemic interrogatives in events anchored in the temporal anteriority

    Directory of Open Access Journals (Sweden)

    Vesela Chergova

    2012-12-01

    Full Text Available The present study attempts to analyse the epistemic modal functionality of temporal posteriority grammemes, referred to the “non-inactual plan”, i. e. the discourse plan measured directly from the moment of enunciation. In our opinion, the invariant category values of a verbal grameme predetermine the development of their complementary and contextual functions. Therefore, the analysis focuses also on the oppositional relations and neutralizations between the categories of verb tense, plan and perspective, on the temporal semantics and the aspectual values which maintain the oppositions between the nominal forms of the verb in accordance with the interpretation of verb categories proposed by Coseriu (1976. In this particular case, the complementary values which outline the scope of our interest fall into the parameters of the possibility and the probability (Veiga, 1991; Kitova-Vasileva, 2000, i.e. conjecture and conclusion in the field of epistemic semantics, yet with an orientation to the temporal anteriority epoch i.e. there is a conjecture regarding actions marked as prior to the moment of enunciation. The syntactic realisation of the epistemic values of conjecture is outlined in the sentence patterns of epistemic interrogatives of the type [Será que + V(P.P.S.] and [Ter(F.S. do Ind.+ V(Part.Pass.]. The study in this way goes beyond the semantic interpretation of the modal, temporal and aspectual values of the morphological instruments of conjecture, and follows the syntactic structure (the modus–dictum relations also in its discourse and pragmatic value.

  16. Massively Parallel Interrogation of Aptamer Sequence, Structure and Function

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, N O; Tok, J B; Tarasow, T M

    2008-02-08

    Optimization of high affinity reagents is a significant bottleneck in medicine and the life sciences. The ability to synthetically create thousands of permutations of a lead high-affinity reagent and survey the properties of individual permutations in parallel could potentially relieve this bottleneck. Aptamers are single stranded oligonucleotides affinity reagents isolated by in vitro selection processes and as a class have been shown to bind a wide variety of target molecules. Methodology/Principal Findings. High density DNA microarray technology was used to synthesize, in situ, arrays of approximately 3,900 aptamer sequence permutations in triplicate. These sequences were interrogated on-chip for their ability to bind the fluorescently-labeled cognate target, immunoglobulin E, resulting in the parallel execution of thousands of experiments. Fluorescence intensity at each array feature was well resolved and shown to be a function of the sequence present. The data demonstrated high intra- and interchip correlation between the same features as well as among the sequence triplicates within a single array. Consistent with aptamer mediated IgE binding, fluorescence intensity correlated strongly with specific aptamer sequences and the concentration of IgE applied to the array. The massively parallel sequence-function analyses provided by this approach confirmed the importance of a consensus sequence found in all 21 of the original IgE aptamer sequences and support a common stem:loop structure as being the secondary structure underlying IgE binding. The microarray application, data and results presented illustrate an efficient, high information content approach to optimizing aptamer function. It also provides a foundation from which to better understand and manipulate this important class of high affinity biomolecules.

  17. Interrogating resilience: toward a typology to improve its operationalization

    Directory of Open Access Journals (Sweden)

    Julie L. Davidson

    2016-06-01

    Full Text Available In the context of accelerated global change, the concept of resilience, with its roots in ecological theory and complex adaptive systems, has emerged as the favored framework for understanding and responding to the dynamics of change. Its transfer from ecological to social contexts, however, has led to the concept being interpreted in multiple ways across numerous disciplines causing significant challenges for its practical application. The aim of this paper is to improve conceptual clarity within resilience thinking so that resilience can be interpreted and articulated in ways that enhance its utility and explanatory power, not only theoretically but also operationally. We argue that the current confusion and ambiguity within resilience thinking is problematic for operationalizing the concept within policy making. To achieve our aim, we interrogate resilience interpretations used within a number of academic and practice domains in the forefront of contending with the disruptive and sometimes catastrophic effects of global change (primarily due to climate change on ecological and human-nature systems. We demonstrate evolution and convergence among disciplines in the interpretations and theoretical underpinnings of resilience and in engagement with cross-scale considerations. From our analysis, we identify core conceptual elements to be considered in policy responses if resilience is to fulfill its potential in improving decision making for change. We offer an original classification of resilience definitions in current use and a typology of resilience interpretations. We conclude that resilience thinking must be open to alternative traditions and interpretations if it is to become a theoretically and operationally powerful paradigm.

  18. The interrogative particle zar - from syntax and semantics to etymology

    Directory of Open Access Journals (Sweden)

    Vlajić-Popović Jasna B.

    2016-01-01

    Full Text Available This paper deals with the Serbian interrogative particle zar/zar/zar ‘num, forsan’, typically positioned at the beginning of a sentence (expressing surprise, wonder, disbelief, dissent, etc. or at its end, coupled with ne and separated by a comma (in guided questions, affirmative and negative alike: Ti ga (ne voliš, zar ne?, yet also broadly attested in obsolete use (in the 19-20th-century literature in modal function, where it is synonymous to valjda, možda ‘perhaps, maybe’. After a review of the ways zar is treated in modern Serbian grammars and descriptive dictionaries (including several dialectal dictionaries, and following research of Macedonian, Bulgarian and Turkish dictionaries, its etymology is discussed: Skok’s unconvincing idioglottal interpretation is refuted, and Rešetar’s idea is reintroduced (prevoiusly rejected by Skok, questioned by Elezović, accepted in the RJA that zar, along with its obliterated forms zaer, zajer, zaher, should be traced back to Turkish zahir adv. ‘apparently, clearly, evidently’, ‘seemingly, perhaps, maybe’. The semantic-syntactic evolution of the loanword within the Serbian language is illustrated, and hence the alloglottal etymology corroborated, by a selection of quotes from folklore and eminent 19-20th-century writers. And finally, as the most likely, the paper offers the interpretation of this particle as a hybrid formation resulting from contamination by the Turkisms of an idioglottal zar, which could be related to archaic Polish zaż < PSl. *za-že. [Projekat Ministarstva nauke Republike Srbije, br. 178007: Etimološka istraživanja srpskog jezika i izrada Etimološkog rečnika srpskog jezika

  19. Toward multi-area distributed network of implanted neural interrogators

    Science.gov (United States)

    Powell, Marc P.; Hou, Xiaoxiao; Galligan, Craig; Ashe, Jeffrey; Borton, David A.

    2017-08-01

    As we aim to improve our understanding of the brain, it is critical that researchers have simultaneous multi-area, large-scale access to the brain. Information processing in the brain occurs through close and distant coupling of functional sub-domains, as opposed to within isolated single neurons. However, commercially available neural interfaces capable of sensing electrophysiology of single neurons, currently allow access to only a small, mm3 volume of cortical cells, are not scalable to recording from orders of magnitude more neurons, and leverage bulky, skull mounted hardware and cabling sensitive to relative movements of the skull and brain. In this work, we propose a system capable of recording from many individual distributed neural interrogator nodes, untethered from any external electronics. Using an array of epidural inductive coils to wirelessly power the implanted electronics, the system is intended to be agnostic to the surgical placement of any individual node. Here, we demonstrate the ability to transmit nearly 15mW of power with greater than 50% power transfer efficiency, benchtop testing of individual subcircuit system components showing successful digitization of neural signals, and wireless transmission currently supporting a data rate of 3.84Mbps. We leverage a software defined radio based RF receiver to demodulate the data which can be stored in memory for later retrieval. Finally, we introduce a packaging technology capable of isolating active electronics from the surrounding tissue while providing capability for electrical feed-through assemblies for external neural interfacing. We expect, based on the presented preliminary findings, that the system can be integrated into a platform technology for the study of the intricate interactions between cortical domains.

  20. Massively parallel interrogation of aptamer sequence, structure and function.

    Directory of Open Access Journals (Sweden)

    Nicholas O Fischer

    Full Text Available BACKGROUND: Optimization of high affinity reagents is a significant bottleneck in medicine and the life sciences. The ability to synthetically create thousands of permutations of a lead high-affinity reagent and survey the properties of individual permutations in parallel could potentially relieve this bottleneck. Aptamers are single stranded oligonucleotides affinity reagents isolated by in vitro selection processes and as a class have been shown to bind a wide variety of target molecules. METHODOLOGY/PRINCIPAL FINDINGS: High density DNA microarray technology was used to synthesize, in situ, arrays of approximately 3,900 aptamer sequence permutations in triplicate. These sequences were interrogated on-chip for their ability to bind the fluorescently-labeled cognate target, immunoglobulin E, resulting in the parallel execution of thousands of experiments. Fluorescence intensity at each array feature was well resolved and shown to be a function of the sequence present. The data demonstrated high intra- and inter-chip correlation between the same features as well as among the sequence triplicates within a single array. Consistent with aptamer mediated IgE binding, fluorescence intensity correlated strongly with specific aptamer sequences and the concentration of IgE applied to the array. CONCLUSION AND SIGNIFICANCE: The massively parallel sequence-function analyses provided by this approach confirmed the importance of a consensus sequence found in all 21 of the original IgE aptamer sequences and support a common stem:loop structure as being the secondary structure underlying IgE binding. The microarray application, data and results presented illustrate an efficient, high information content approach to optimizing aptamer function. It also provides a foundation from which to better understand and manipulate this important class of high affinity biomolecules.

  1. Battery-less wireless interrogation of microstrip patch antenna for strain sensing

    International Nuclear Information System (INIS)

    Xu, X; Huang, H

    2012-01-01

    This paper presents a battery-less wireless interrogation system that can measure the resonant frequency of a microstrip patch antenna with a fine resolution. Since the antenna resonant frequency is sensitive to strain-induced deformations, wireless interrogation of the antenna sensor for strain measurement was demonstrated. By implementing a microwatt impedance switching circuit at the sensor node, the antenna backscattering is amplitude modulated at the sensor node so that it can be separated from the structural backscattering at the interrogator. The sensor node can be powered by a small photocell and thus achieve battery-less operation. The operating principle of the wireless interrogation system is first described, followed by the implementation and characterization of the wireless interrogation system. The antenna resonant frequency shifts were correlated to the applied strains through a static tensile experiment. An excellent agreement between the experimental results and the analytical prediction was obtained. A power transmission model was established and validated with experimental measurements. Based on this power transmission model, we estimated that the maximum interrogation distance of the wireless strain measurement system is 26 m. (paper)

  2. Multi-Wavelength Polarimetry of Isolated Neutron Stars

    Directory of Open Access Journals (Sweden)

    Roberto P. Mignani

    2018-03-01

    Full Text Available Isolated neutron stars are known to be endowed with extreme magnetic fields, whose maximum intensity ranges from 10 12 – 10 15 G, which permeates their magnetospheres. Their surrounding environment is also strongly magnetized, especially in the compact nebulae powered by the relativistic wind from young neutron stars. The radiation from isolated neutron stars and their surrounding nebulae is, thus, supposed to bring a strong polarization signature. Measuring the neutron star polarization brings important information about the properties of their magnetosphere and of their highly magnetized environment. Being the most numerous class of isolated neutron stars, polarization measurements have been traditionally carried out for radio pulsars, hence in the radio band. In this review, I summarize multi-wavelength linear polarization measurements obtained at wavelengths other than radio both for pulsars and other types of isolated neutron stars and outline future perspectives with the upcoming observing facilities.

  3. 21 CFR 11.50 - Signature manifestations.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Signature manifestations. 11.50 Section 11.50 Food... RECORDS; ELECTRONIC SIGNATURES Electronic Records § 11.50 Signature manifestations. (a) Signed electronic...: (1) The printed name of the signer; (2) The date and time when the signature was executed; and (3...

  4. 76 FR 30542 - Adult Signature Services

    Science.gov (United States)

    2011-05-26

    ... POSTAL SERVICE 39 CFR Part 111 Adult Signature Services AGENCY: Postal Service\\TM\\. ACTION: Final..., Domestic Mail Manual (DMM[supreg]) 503.8, to add a new extra service called Adult Signature. This new service has two available options: Adult Signature Required and Adult Signature Restricted Delivery. DATES...

  5. 1 CFR 18.7 - Signature.

    Science.gov (United States)

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false Signature. 18.7 Section 18.7 General Provisions... PREPARATION AND TRANSMITTAL OF DOCUMENTS GENERALLY § 18.7 Signature. The original and each duplicate original... stamped beneath the signature. Initialed or impressed signatures will not be accepted. Documents submitted...

  6. Attribute-Based Digital Signature System

    NARCIS (Netherlands)

    Ibraimi, L.; Asim, Muhammad; Petkovic, M.

    2011-01-01

    An attribute-based digital signature system comprises a signature generation unit (1) for signing a message (m) by generating a signature (s) based on a user secret key (SK) associated with a set of user attributes, wherein the signature generation unit (1) is arranged for combining the user secret

  7. Shell gap reduction in neutron-rich N=17 nuclei

    International Nuclear Information System (INIS)

    Obertelli, A.; Gillibert, A.; Alamanos, N.; Alvarez, M.; Auger, F.; Dayras, R.; Drouart, A.; France, G. de; Jurado, B.; Keeley, N.; Lapoux, V.; Mittig, W.; Mougeot, X.; Nalpas, L.; Pakou, A.; Patronis, N.; Pollacco, E.C.; Rejmund, F.; Rejmund, M.; Roussel-Chomaz, P.; Savajols, H.; Skaza, F.; Theisen, Ch.

    2006-01-01

    The spectroscopy of 27 Ne has been investigated through the one-neutron transfer reaction 26 Ne(d,p) 27 Ne in inverse kinematics at 9.7 MeV/nucleon. The results strongly support the existence of a low-lying negative parity state in 27 Ne, which is a signature of a reduced sd-fp shell gap in the N=16 neutron-rich region, at variance with stable nuclei

  8. neutron radiography

    International Nuclear Information System (INIS)

    Barton, J.P.

    1993-01-01

    Neutron radiography (or radiology) is a diverse filed that uses neutrons of various energies, subthermal, thermal, epithermal or fast in either steady state or pulsed mode to examine objects for industrial, medical, or other purposes, both microscopic and macroscopic. The applications include engineering design, biological studies, nondestructive inspection and materials evaluation. In the past decade, over 100 different centers in some 30 countries have published reports of pioneering activities using reactors, accelerators and isotopic neutron sources. While film transparency and electronic video are most common imaging methods for static or in motion objects respectively, there are other important data gathering techniques, including track etch, digital gauging and computed tomography. A survey of the world-wide progress shows the field to be gaining steadily in its diversity, its sophistication and its importance. (author)

  9. Neutron kinetics in moderators and SNM detection through epithermal-neutron-induced fissions

    Energy Technology Data Exchange (ETDEWEB)

    Gozani, Tsahi, E-mail: tgmaven@gmail.com [1050 Harriet St., Palo Alto, CA 94301 (United States); King, Michael J. [Rapiscan Laboratories Inc., 520 Almanor Ave., Sunnyvale, CA 94085 (United States)

    2016-01-01

    Extension of the well-established Differential Die Away Analysis (DDAA) into a faster time domain, where more penetrating epithermal neutrons induce fissions, is proposed and demonstrated via simulations and experiments. In the proposed method the fissions stimulated by thermal, epithermal and even higher-energy neutrons are measured after injection of a narrow pulse of high-energy 14 MeV (d,T) or 2.5 MeV (d,D) source neutrons, appropriately moderated. The ability to measure these fissions stems from the inherent correlation of neutron energy and time (“E–T” correlation) during the process of slowing down of high-energy source neutrons in common moderating materials such as hydrogenous compounds (e.g., polyethylene), heavy water, beryllium and graphite. The kinetic behavior following injection of a delta-function-shaped pulse (in time) of 14 MeV neutrons into such moderators is studied employing MCNPX simulations and, when applicable, some simple “one-group” models. These calculations served as a guide for the design of a source moderator which was used in experiments. Qualitative relationships between slowing-down time after the pulse and the prevailing neutron energy are discussed. A laboratory system consisting of a 14 MeV neutron generator, a polyethylene-reflected Be moderator, a liquid scintillator with pulse-shape discrimination (PSD) and a two-parameter E–T data acquisition system was set up to measure prompt neutron and delayed gamma-ray fission signatures in a 19.5% enriched LEU sample. The measured time behavior of thermal and epithermal neutron fission signals agreed well with the detailed simulations. The laboratory system can readily be redesigned and deployed as a mobile inspection system for SNM in, e.g., cars and vans. A strong pulsed neutron generator with narrow pulse (<75 ns) at a reasonably high pulse frequency could make the high-energy neutron induced fission modality a realizable SNM detection technique.

  10. A dense plasma focus-based neutron source for a single-shot detection of illicit materials and explosives by a nanosecond neutron pulse

    International Nuclear Information System (INIS)

    Gribkov, V A; Latyshev, S V; Miklaszewski, R A; Chernyshova, M; Drozdowicz, K; Wiacek, U; Tomaszewski, K; Lemeshko, B D

    2010-01-01

    Recent progress in a single-pulse Nanosecond Impulse Neutron Investigation System (NINIS) intended for interrogation of hidden objects by means of measuring elastically scattered neutrons is presented in this paper. The method uses very bright neutron pulses having duration of the order of 10 ns only, which are generated by dense plasma focus (DPF) devices filled with pure deuterium or DT mixture as a working gas. The small size occupied by the neutron bunch in space, number of neutrons per pulse and mono-chromaticity (ΔE/E∼1%) of the neutron spectrum provides the opportunity to use a time-of-flight (TOF) technique with flying bases of about a few metres. In our researches we used DPF devices having bank energy in the range 2-7 kJ. The devices generate a neutron yield of the level of 10 8 -10 9 2.45 MeV and 10 10 -10 11 14 MeV neutrons per pulse with pulse duration ∼10-20 ns. TOF base in the tests was 2.2-18.5 m. We have demonstrated the possibility of registering of neutrons scattered by the substances under investigation-1 litre bottles with methanol (CH 3 OH), phosphoric (H 2 PO 4 ) and nitric (HNO 3 ) acids as well as a long object-a 1 m gas tank filled with deuterium at high pressure. It is shown that the above mentioned short TOF bases and relatively low neutron yields are enough to distinguish different elements' nuclei composing the substance under interrogation and to characterize the geometry of lengthy objects in some cases. The wavelet technique was employed to 'clean' the experimental data registered. The advantages and restrictions of the proposed and tested NINIS technique in comparison with other methods are discussed.

  11. CVD polycrystalline diamond. A novel neutron detector and applications

    International Nuclear Information System (INIS)

    Mongkolnavin, R.

    1998-07-01

    Chemical Vapour Deposition (CVD) Polycrystalline Diamond film has been investigated as a low noise sensor for beta particles, gammas and neutrons using High Energy Physics technologies. Its advantages and disadvantages have been explored in comparison with other particle detectors such as silicon detector and other plastic scintillators. The performance and characteristic of the diamond detector have been fully studied and discussed. These studies will lead to a better understanding of how CVD diamonds perform as a detector and how to improve their performance under various conditions. A CVD diamond detector model has been proposed which is an attempt to explain the behaviour of such an extreme detector material. A novel neutron detector is introduced as a result of these studies. A good thermal and fast neutron detector can be fabricated with CVD diamond with new topologies. This detector will perform well without degradation in a high neutron radiation environment, as diamond is known to be radiation-hard. It also offers better neutrons and gammas discrimination for high gamma background applications compared to other semiconductor detectors. A full simulation of the detector has also been done using GEANT, a Monte Carlo simulation program for particle detectors. Simulation results show that CVD diamond detectors with this novel topology can detect neutrons with great directionality. Experimental work has been done on this detector in a nuclear reactor environment and accelerator source. A novel neutron source which offers a fast pulse high-energy neutrons has also been studied. With this detector, applications in neutron spectrometry for low-Z material have been pursued with various neutron detection techniques. One of these is a low-Z material identification system. The system has been designed and simulated for contraband luggage interrogation using the detector and the novel neutron source. (author)

  12. Quantum messages with signatures forgeable in arbitrated quantum signature schemes

    International Nuclear Information System (INIS)

    Kim, Taewan; Choi, Jeong Woon; Jho, Nam-Su; Lee, Soojoon

    2015-01-01

    Even though a method to perfectly sign quantum messages has not been known, the arbitrated quantum signature scheme has been considered as one of the good candidates. However, its forgery problem has been an obstacle to the scheme becoming a successful method. In this paper, we consider one situation, which is slightly different from the forgery problem, that we use to check whether at least one quantum message with signature can be forged in a given scheme, although all the messages cannot be forged. If there are only a finite number of forgeable quantum messages in the scheme, then the scheme can be secured against the forgery attack by not sending forgeable quantum messages, and so our situation does not directly imply that we check whether the scheme is secure against the attack. However, if users run a given scheme without any consideration of forgeable quantum messages, then a sender might transmit such forgeable messages to a receiver and in such a case an attacker can forge the messages if the attacker knows them. Thus it is important and necessary to look into forgeable quantum messages. We show here that there always exists such a forgeable quantum message-signature pair for every known scheme with quantum encryption and rotation, and numerically show that there are no forgeable quantum message-signature pairs that exist in an arbitrated quantum signature scheme. (paper)

  13. SIGNATURE: A workbench for gene expression signature analysis

    Directory of Open Access Journals (Sweden)

    Chang Jeffrey T

    2011-11-01

    Full Text Available Abstract Background The biological phenotype of a cell, such as a characteristic visual image or behavior, reflects activities derived from the expression of collections of genes. As such, an ability to measure the expression of these genes provides an opportunity to develop more precise and varied sets of phenotypes. However, to use this approach requires computational methods that are difficult to implement and apply, and thus there is a critical need for intelligent software tools that can reduce the technical burden of the analysis. Tools for gene expression analyses are unusually difficult to implement in a user-friendly way because their application requires a combination of biological data curation, statistical computational methods, and database expertise. Results We have developed SIGNATURE, a web-based resource that simplifies gene expression signature analysis by providing software, data, and protocols to perform the analysis successfully. This resource uses Bayesian methods for processing gene expression data coupled with a curated database of gene expression signatures, all carried out within a GenePattern web interface for easy use and access. Conclusions SIGNATURE is available for public use at http://genepattern.genome.duke.edu/signature/.

  14. NEUTRONIC REACTOR

    Science.gov (United States)

    Wigner, E.P.; Weinberg, A.W.; Young, G.J.

    1958-04-15

    A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

  15. Neutron dosimeter

    International Nuclear Information System (INIS)

    Bartko, J.; Schoch, K.F. Jr.; Congedo, T.V.; Anderson, S.L. Jr.

    1989-01-01

    This patent describes a nuclear reactor. It comprises a reactor core; a thermal shield surrounding the reactor core; a pressure vessel surrounding the thermal shield; a neutron dosimeter positioned outside of the thermal shield, the neutron dosimeter comprising a layer of fissile material and a second layer made of a material having an electrical conductivity which permanently varies as a function of its cumulative ion radiation dose; and means, outside the pressure vessel and electrically connected to the layer of second material, for measuring electrical conductivity of the layer of second material

  16. Quantitative neutron radiography using neutron absorbing honeycomb

    International Nuclear Information System (INIS)

    Tamaki, Masayoshi; Oda, Masahiro; Takahashi, Kenji; Ohkubo, Kohei; Tasaka, Kanji; Tsuruno, Akira; Matsubayashi, Masahito.

    1993-01-01

    This investigation concerns quantitative neutron radiography and computed tomography by using a neutron absorbing honeycomb collimator. By setting the neutron absorbing honeycomb collimator between object and imaging system, neutrons scattered in the object were absorbed by the honeycomb material and eliminated before coming to the imaging system, but the neutrons which were transmitted the object without interaction could reach the imaging system. The image by purely transmitted neutrons gives the quantitative information. Two honeycombs were prepared with coating of boron nitride and gadolinium oxide and evaluated for the quantitative application. The relation between the neutron total cross section and the attenuation coefficient confirmed that they were in a fairly good agreement. Application to quantitative computed tomography was also successfully conducted. The new neutron radiography method using the neutron-absorbing honeycomb collimator for the elimination of the scattered neutrons improved remarkably the quantitativeness of the neutron radiography and computed tomography. (author)

  17. Neutronics of pulsed spallation neutron sources

    CERN Document Server

    Watanabe, N

    2003-01-01

    Various topics and issues on the neutronics of pulsed spallation neutron sources, mainly for neutron scattering experiments, are reviewed to give a wide circle of readers a better understanding of these sources in order to achieve a high neutronic performance. Starting from what neutrons are needed, what the spallation reaction is and how to produce slow-neutrons more efficiently, the outline of the target and moderator neutronics are explained. Various efforts with some new concepts or ideas have already been devoted to obtaining the highest possible slow-neutron intensity with desired pulse characteristics. This paper also reviews the recent progress of such efforts, mainly focused on moderator neutronics, since moderators are the final devices of a neutron source, which determine the source performance. Various governing parameters for neutron-pulse characteristics such as material issues, geometrical parameters (shape and dimensions), the target-moderator coupling scheme, the ortho-para-hydrogen ratio, po...

  18. Signature molecular descriptor : advanced applications.

    Energy Technology Data Exchange (ETDEWEB)

    Visco, Donald Patrick, Jr. (Tennessee Technological University, Cookeville, TN)

    2010-04-01

    In this work we report on the development of the Signature Molecular Descriptor (or Signature) for use in the solution of inverse design problems as well as in highthroughput screening applications. The ultimate goal of using Signature is to identify novel and non-intuitive chemical structures with optimal predicted properties for a given application. We demonstrate this in three studies: green solvent design, glucocorticoid receptor ligand design and the design of inhibitors for Factor XIa. In many areas of engineering, compounds are designed and/or modified in incremental ways which rely upon heuristics or institutional knowledge. Often multiple experiments are performed and the optimal compound is identified in this brute-force fashion. Perhaps a traditional chemical scaffold is identified and movement of a substituent group around a ring constitutes the whole of the design process. Also notably, a chemical being evaluated in one area might demonstrate properties very attractive in another area and serendipity was the mechanism for solution. In contrast to such approaches, computer-aided molecular design (CAMD) looks to encompass both experimental and heuristic-based knowledge into a strategy that will design a molecule on a computer to meet a given target. Depending on the algorithm employed, the molecule which is designed might be quite novel (re: no CAS registration number) and/or non-intuitive relative to what is known about the problem at hand. While CAMD is a fairly recent strategy (dating to the early 1980s), it contains a variety of bottlenecks and limitations which have prevented the technique from garnering more attention in the academic, governmental and industrial institutions. A main reason for this is how the molecules are described in the computer. This step can control how models are developed for the properties of interest on a given problem as well as how to go from an output of the algorithm to an actual chemical structure. This report

  19. Methods for Characterization of Batteries Using Acoustic Interrogation

    Science.gov (United States)

    Bhadra, Shoham

    Batteries are a ubiquitous form of electrochemical energy storage, but thus far the methods for measuring the mechanical properties of batteries and their component materials in operando have lagged far behind the methods for measuring the corresponding electrical properties. In this thesis, I demonstrate methods for determining the changes in materials properties of an electrochemical energy storage cell both ex situ and in operando.. I begin by establishing the impact of micro-scale morphology changes on the macro-scale dynamic mechanical response in commercial alkaline AA cells. Using a bounce test, the coefficient of restitution (COR) of the cell is shown to increase non-linearly as a function of state of charge (SOC). I show that the reason for the increase in the COR stems from the spatially-dependent oxidation of the Zn anode, with an initial increase corresponding to the formation of a percolation pathway of ZnO-clad Zn particles spanning the radius of the anode. The subsequent saturation of the COR is shown to result from the ultimate solidification and desiccation of the Zn anode. Building from this, I present a generalized in operando solution for materials characterization in batteries using ultrasonic interrogation. The materials properties of battery components change during charge and discharge, resulting in a change in the sound speed of the materials. By attaching transducers to a battery during cycling and sending ultrasonic pulses through each cell I observe the changes in the time of flight (ToF) of the pulses, both in reflection and transmission. I show that the changes in ToF correspond to both SOC and state of health (SOH) in a variety of battery chemistries and geometries, and detail a corresponding acoustic conservation law model framework. Finally, I perform these electrochemical acoustic time of flight (EAToF) experiments on commercial alkaline AA cells. By correlating the results with energy dispersive x-ray diffraction (EDXRD) data and

  20. Material classification by fast neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Buffler, A. E-mail: abuffler@physci.uct.ac.za; Brooks, F.D. E-mail: brooks@physci.uct.ac.za; Allie, M.S.; Bharuth-Ram, K.; Nchodu, M.R

    2001-02-01

    The scattering of a beam of fast monoenergetic neutrons is used to determine elemental compositions of bulk samples (0.2-0.8 kg) of materials composed from one or more of the elements H, C, N, O, Al, S, Fe and Pb. Scattered neutrons are detected by liquid scintillators placed at forward and at backward angles. Different elements are identified by their characteristic scattering signatures derived either from a combination of time-of-flight and pulse height measurements, or from pulse height measurements alone. Scattering signatures measured for multi-element samples are analysed to determine atom fractions for H, C, N, O and other elements in the sample. Atom fractions determined from scattering signatures are insensitive to neutron interactions in material surrounding the scattering sample, provided the amount of material is not excessive. The atom fraction data are used to classify scattering material into categories including 'explosives', 'illicit drugs' and 'other materials' for the purpose of contraband detection.

  1. Neutronic reactor

    International Nuclear Information System (INIS)

    Wende, C.W.J.

    1976-01-01

    The method of operating a water-cooled neutronic reactor having a graphite moderator is described which comprises flowing a gaseous mixture of carbon dioxide and helium, in which the helium comprises 40--60 volume percent of the mixture, in contact with the graphite moderator. 2 claims, 4 figures

  2. Neutron reflectivity

    Directory of Open Access Journals (Sweden)

    Cousin Fabrice

    2015-01-01

    Full Text Available The specular neutron reflectivity is a technique enabling the measurement of neutron scattering length density profile perpendicular to the plane of a surface or an interface, and thereby the profile of chemical composition. The characteristic sizes that are probed range from around 5 Å up 5000 Å. It is a scattering technique that averages information on the entire surface and it is therefore not possible to obtain information within the plane of the interface. The specific properties of neutrons (possibility of tuning the contrast by isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons makes it particularly interesting in the fields of soft matter, biophysics and magnetic thin films. This course is a basic introduction to the technique and does not address the magnetic reflectivity. It is composed of three parts describing respectively its principle and its formalism, the experimental aspects of the method (spectrometers, samples and two examples related to the materials for energy.

  3. Methods for absorbing neutrons

    Science.gov (United States)

    Guillen, Donna P [Idaho Falls, ID; Longhurst, Glen R [Idaho Falls, ID; Porter, Douglas L [Idaho Falls, ID; Parry, James R [Idaho Falls, ID

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  4. Neutron stars as cosmic neutron matter laboratories

    International Nuclear Information System (INIS)

    Pines, D.

    1986-01-01

    Recent developments which have radically changed our understanding of the dynamics of neutron star superfluids and the free precession of neutron stars are summarized, and the extent to which neutron stars are cosmic neutron matter laboratories is discussed. 17 refs., 1 tab

  5. Compact deuterium-tritium neutron generator using a novel field ionization source

    Energy Technology Data Exchange (ETDEWEB)

    Ellsworth, J. L., E-mail: ellsworth7@llnl.gov; Falabella, S.; Sanchez, J.; Tang, V. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Wang, H. [Department of Computer Science, Stanford University, Stanford, California 94305 (United States)

    2014-11-21

    Active interrogation using neutrons is an effective method for detecting shielded nuclear material. A lightweight, lunch-box-sized, battery-operated neutron source would enable new concepts of operation in the field. We have developed at-scale components for a highly portable, completely self-contained, pulsed Deuterium-Tritium (DT) neutron source producing 14 MeV neutrons with average yields of 10{sup 7} n/s. A gated, field ionization ion source using etched electrodes has been developed that produces pulsed ion currents up to 500 nA. A compact Cockcroft-Walton high voltage source is used to accelerate deuterons into a metal hydride target for neutron production. The results of full scale DT tests using the field ionization source are presented.

  6. Operational status and future plans for the Los Alamos Neutron Science Center

    International Nuclear Information System (INIS)

    Jones, Kevin W.; Schoenberg, Kurt F.

    2008-01-01

    The Los Alamos Neutron Science Center (LANSCE) continues to be a signature experimental science facility at Los Alamos National Laboratory (LANL). The 800 MeV linear proton accelerator provides multiplexed beams to five unique target stations to produce medical radioisotopes, ultra-cold neutrons, thermal and high energy neutrons for material and nuclear science, and to conduct proton radiography of dynamic events. Recent operating experience will be reviewed and the role of an enhanced LANSCE facility in LANL's new signature facility initiative, Matter and Radiation in Extremes (MaRIE) will be discussed.

  7. Basic of Neutron NDA

    Energy Technology Data Exchange (ETDEWEB)

    Trahan, Alexis Chanel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-15

    The objectives of this presentation are to introduce the basic physics of neutron production, interactions and detection; identify the processes that generate neutrons; explain the most common neutron mechanism, spontaneous and induced fission and (a,n) reactions; describe the properties of neutron from different sources; recognize advantages of neutron measurements techniques; recognize common neutrons interactions; explain neutron cross section measurements; describe the fundamental of 3He detector function and designs; and differentiate between passive and active assay techniques.

  8. Five Guidelines for Selecting Hydrological Signatures

    Science.gov (United States)

    McMillan, H. K.; Westerberg, I.; Branger, F.

    2017-12-01

    Hydrological signatures are index values derived from observed or modeled series of hydrological data such as rainfall, flow or soil moisture. They are designed to extract relevant information about hydrological behavior, such as to identify dominant processes, and to determine the strength, speed and spatiotemporal variability of the rainfall-runoff response. Hydrological signatures play an important role in model evaluation. They allow us to test whether particular model structures or parameter sets accurately reproduce the runoff generation processes within the watershed of interest. Most modeling studies use a selection of different signatures to capture different aspects of the catchment response, for example evaluating overall flow distribution as well as high and low flow extremes and flow timing. Such studies often choose their own set of signatures, or may borrow subsets of signatures used in multiple other works. The link between signature values and hydrological processes is not always straightforward, leading to uncertainty and variability in hydrologists' signature choices. In this presentation, we aim to encourage a more rigorous approach to hydrological signature selection, which considers the ability of signatures to represent hydrological behavior and underlying processes for the catchment and application in question. To this end, we propose a set of guidelines for selecting hydrological signatures. We describe five criteria that any hydrological signature should conform to: Identifiability, Robustness, Consistency, Representativeness, and Discriminatory Power. We describe an example of the design process for a signature, assessing possible signature designs against the guidelines above. Due to their ubiquity, we chose a signature related to the Flow Duration Curve, selecting the FDC mid-section slope as a proposed signature to quantify catchment overall behavior and flashiness. We demonstrate how assessment against each guideline could be used to

  9. Scalable interrogation: Eliciting human pheromone responses to deception in a security interview setting.

    Science.gov (United States)

    Stedmon, Alex W; Eachus, Peter; Baillie, Les; Tallis, Huw; Donkor, Richard; Edlin-White, Robert; Bracewell, Robert

    2015-03-01

    Individuals trying to conceal knowledge from interrogators are likely to experience raised levels of stress that can manifest itself across biological, physiological, psychological and behavioural factors, providing an opportunity for detection. Using established research paradigms an innovative scalable interrogation was designed in which participants were given a 'token' that represented information they had to conceal from interviewers. A control group did not receive a token and therefore did not have to deceive the investigators. The aim of this investigation was to examine differences between deceivers and truth-tellers across the four factors by collecting data for cortisol levels, sweat samples, heart-rate, respiration, skin temperature, subjective stress ratings and video and audio recordings. The results provided an integrated understanding of responses to interrogation by those actively concealing information and those acting innocently. Of particular importance, the results also suggest, for the first time in an interrogation setting, that stressed individuals may secrete a volatile steroid based marker that could be used for stand-off detection. The findings are discussed in relation to developing a scalable interrogation protocol for future research in this area. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  10. Ultrafast Fiber Bragg Grating Interrogation for Sensing in Detonation and Shock Wave Experiments.

    Science.gov (United States)

    Rodriguez, George; Gilbertson, Steve M

    2017-01-27

    Chirped fiber Bragg grating (CFBG) sensors coupled to high speed interrogation systems are described as robust diagnostic approaches to monitoring shock wave and detonation front propagation tracking events for use in high energy density shock physics applications. Taking advantage of the linear distributed spatial encoding of the spectral band in single-mode CFBGs, embedded fiber systems and associated photonic interrogation methodologies are shown as an effective approach to sensing shock and detonation-driven loading processes along the CFBG length. Two approaches, one that detects spectral changes in the integrated spectrum of the CFBG and another coherent pulse interrogation approach that fully resolves its spectral response, shows that 100-MHz-1-GHz interrogation rates are possible with spatial resolution along the CFBG in the 50 µm to sub-millimeter range depending on the combination of CFBG parameters (i.e., length, chirp rate, spectrum) and interrogator design specifics. Results from several dynamic tests are used to demonstrate the performance of these high speed systems for shock and detonation propagation tracking under strong and weak shock pressure loading: (1) linear detonation front tracking in the plastic bonded explosive (PBX) PBX-9501; (2) tracking of radial decaying shock with crossover to non-destructive CFBG response; (3) shock wave tracking along an aluminum cylinder wall under weak loading accompanied by dynamic strain effects in the CFBG sensor.

  11. Progress in miniaturization of a multichannel optical fiber Bragg grating sensor interrogator

    Science.gov (United States)

    Lopatin, Craig M.; Mahmood, Shah; Mendoza, Edgar; Moslehi, Behzad; Black, Richard; Chau, Kelvin; Oblea, Levy

    2007-07-01

    An effort to develop a miniaturized multichannel optical fiber Bragg grating sensor interrogator was initiated in 2006 under the Small Business Innovative Research (SBIR) program. The goal was to develop an interrogator that would be sufficiently small and light to be incorporated into a health monitoring system for use on tactical missiles. Two companies, Intelligent Fiber Optic Systems Corporation (IFOS) and Redondo Optics, were funded in Phase I, and this paper describes the prototype interrogators that were developed. The two companies took very different approaches: IFOS focused on developing a unit that would have a high channel count and high resolution, using off-the-shelf components, while Redondo Optics chose to develop a unit that would be very small and lightweight, using custom designed integrated optical chips. It is believed that both approaches will result in interrogators that will be significantly small, lighter, and possibly even more precise than what is currently commercially available. This paper will also briefly describe some of the sensing concepts that may be used to interrogate the health of the solid rocket motors used in many missile systems. The sponsor of this program was NAVAIR PMA 280.

  12. Sequential interrogation of multiple FBG sensors using LPG modulation and an artificial neural network

    International Nuclear Information System (INIS)

    Basu, Mainak; Ghorai, S K

    2015-01-01

    Interrogating multiple fiber Bragg gratings (FBG) requires highly sensitive spectrum scanning equipment such as optical spectrum analyzers, tunable filters, acousto-optic tunable filters etc, which are expensive, bulky and time consuming. In this paper, we present a new approach for multiple FBG sensor interrogation using long-period gratings and an artificial neural network. The reflection spectra of the multiplexed FBGs are modulated by two long period gratings separately and the modulated optical intensities were detected by two photodetectors. The outputs of the detectors are then used as input in a previously trained artificial neural network to interrogate the FBG sensors. Simulations have been performed to determine the strain and wavelength shift using two and four sensors. The interrogation system has also been demonstrated experimentally for two sensors using simply supported beams in the range of 0–350 μstrain. The proposed interrogation scheme has been found to identify the perturbed FBG, and to determine strain and wavelength shift with reasonable accuracy. (paper)

  13. Narrowband interrogation of plasmonic optical fiber biosensors based on spectral combs

    Science.gov (United States)

    González-Vila, Álvaro; Kinet, Damien; Mégret, Patrice; Caucheteur, Christophe

    2017-11-01

    Gold-coated tilted fiber Bragg gratings can probe surface Plasmon polaritons with high resolution and sensitivity. In this work, we report two configurations to interrogate such plasmonic biosensors, with the aim of providing more efficient alternatives to the widespread spectrometer-based techniques. To this aim, the interrogation is based on measuring the optical power evolution of the cladding modes with respect to surrounding refractive index changes instead of computing their wavelength shift. Both setups are composed of a broadband source and a photodiode and enable a narrowband interrogation around the cladding mode that excites the surface Plasmon resonance. The first configuration makes use of a uniform fiber Bragg grating to filter the broadband response of the source in a way that the final interrogation is based on an intensity modulation measured in transmission. The second setup uses a uniform fiber grating too, but located beyond the sensor and acting as a selective optical mirror, so the interrogation is carried out in reflection. Both configurations are compared, showing interesting differential features. The first one exhibits a very high sensitivity while the second one has an almost temperature-insensitive behavior. Hence, the choice of the most appropriate method will be driven by the requirements of the target application.

  14. Sharpening Precision Medicine by a Thorough Interrogation of Metabolic Individuality

    Directory of Open Access Journals (Sweden)

    Kirk Beebe

    2016-01-01

    Full Text Available Precision medicine is an active component of medical practice today, but aspirations are to both broaden its reach to a greater diversity of individuals and improve its “precision” by enhancing the ability to define even more disease states in combination with associated treatments. Given complexity of human phenotypes, much work is required. In this review, we deconstruct this challenge at a high level to define what is needed to move closer toward these aspirations. In the context of the variables that influence the diverse array of phenotypes across human health and disease – genetics, epigenetics, environmental influences, and the microbiome – we detail the factors behind why an individual's biochemical (metabolite composition is increasingly regarded as a key element to precisely defining phenotypes. Although an individual's biochemical (metabolite composition is generally regarded, and frequently shown, to be a surrogate to the phenotypic state, we review how metabolites (and therefore an individual's metabolic profile are also functionally related to the myriad of phenotypic influencers like genetics and the microbiota. We describe how using the technology to comprehensively measure an individual's biochemical profile – metabolomics – is integrative to defining individual phenotypes and how it is currently being deployed in efforts to continue to elaborate on human health and disease in large population studies. Finally, we summarize instances where metabolomics is being used to assess individual health in instances where signatures (i.e. biomarkers have been defined.

  15. Digital Signature Schemes with Complementary Functionality and Applications

    OpenAIRE

    S. N. Kyazhin

    2012-01-01

    Digital signature schemes with additional functionality (an undeniable signature, a signature of the designated confirmee, a signature blind, a group signature, a signature of the additional protection) and examples of their application are considered. These schemes are more practical, effective and useful than schemes of ordinary digital signature.

  16. Neutron activation autoradiography of paintings by Rembrandt and his time

    International Nuclear Information System (INIS)

    Fischer, C.O.; Leuther, W.; Laurenze, C.; Slusallek, K.

    1988-01-01

    As part of a Rembrandt Research Project, 19 paintings of the Dahlem gallery in Berlin have been investigated by neutron activation autoradiography. The autoradiographs make visible underlying structures such as preparatory sketches, conceptional changes, signatures, and the individual brush-work of the artist. (author)

  17. Neutron scattering studies of low dimensional magnetic systems

    DEFF Research Database (Denmark)

    Hansen, Ursula Bengård

    investigated at low temperaturesand in a longitudinal magnetic eld using neutron spectroscopy. Here we observe thehybridisation of the magnon bound states, inherent to the low dimensional nature ofCoCl2 · 2D2O.At higher temperature, signatures which can be attributed to Magnetic Bloch Oscillationsis observed...

  18. Magnetic Nanotweezers for Interrogating Biological Processes in Space and Time.

    Science.gov (United States)

    Kim, Ji-Wook; Jeong, Hee-Kyung; Southard, Kaden M; Jun, Young-Wook; Cheon, Jinwoo

    2018-04-17

    The ability to sense and manipulate the state of biological systems has been extensively advanced during the past decade with the help of recent developments in physical tools. Unlike standard genetic and pharmacological perturbation techniques-knockdown, overexpression, small molecule inhibition-that provide a basic on/off switching capability, these physical tools provide the capacity to control the spatial, temporal, and mechanical properties of the biological targets. Among the various physical cues, magnetism offers distinct advantages over light or electricity. Magnetic fields freely penetrate biological tissues and are already used for clinical applications. As one of the unique features, magnetic fields can be transformed into mechanical stimuli which can serve as a cue in regulating biological processes. However, their biological applications have been limited due to a lack of high-performance magnetism-to-mechanical force transducers with advanced spatiotemporal capabilities. In this Account, we present recent developments in magnetic nanotweezers (MNTs) as a useful tool for interrogating the spatiotemporal control of cells in living tissue. MNTs are composed of force-generating magnetic nanoparticles and field generators. Through proper design and the integration of individual components, MNTs deliver controlled mechanical stimulation to targeted biomolecules at any desired space and time. We first discuss about MNT configuration with different force-stimulation modes. By modulating geometry of the magnetic field generator, MNTs exert pulling, dipole-dipole attraction, and rotational forces to the target specifically and quantitatively. We discuss the key physical parameters determining force magnitude, which include magnetic field strength, magnetic field gradient, magnetic moment of the magnetic particle, as well as distance between the field generator and the particle. MNTs also can be used over a wide range of biological time scales. By simply

  19. Optical measuring system with an interrogator and a polymer-based single-mode fibre optic sensor system

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to an optical measuring system comprising a polymer-based single-mode fibre-optic sensor system (102), an optical interrogator (101), and an optical arrangement (103) interconnecting the optical interrogator (101) and the polymer-based single-mode fibre-optic sensor...... system (102). The invention further relates to an optical interrogator adapted to be connected to a polymer-based single-mode fibre-optic sensor system via an optical arrangement. The interrogator comprises a broadband light source arrangement (104) and a spectrum analysing arrangement which receives...

  20. Associated-particle sealed-tube neutron generators and hodoscopes for NDA applications

    International Nuclear Information System (INIS)

    Rhodes, E.; Peters, C.W.

    1991-01-01

    With radioisotope sources, gamma-ray transmission hodoscopes can inspect canisters and railcars to monitor rocket motors, can detect nuclear warheads by their characteristic strong gamma-ray absorption, or can count nuclear warheads inside a missile by low-resolution tomography. Intrinsic gamma-ray radiation from warheads can also be detected in a passive mode. Neutron hodoscopes can use neutron transmission, intrinsic neutron emission, or reactions stimulated by a neutron source, in treaty verification roles. Gamma-ray and neutron hodoscopes can be combined with a recently developed neutron diagnostic probe system, based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutrons, and that uses flight-time to electronically collimate transmitted neutrons and to tomographically image nuclides identified by reaction gamma-rays. Gamma-ray spectra of resulting neutron reactions identify nuclides associated with all major chemicals in chemical warfare agents, explosives, and drugs, as well as many pollutants and fissile and fertile special nuclear material. 5 refs., 12 figs

  1. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2013-01-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, nanostructures investigated by small-angle neutron scattering, structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic neutron scattering, strongly correlated electrons, polymer dynamics, applications of neutron scattering. (HSI)

  2. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2012-01-01

    The following topics are dealt with: Neutron scattering in contemporary research, neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  3. Pulsed neutron generator

    International Nuclear Information System (INIS)

    Bespalov, D.F.; Bykovskii, Yu.A.; Vergun, I.I.; Kozlovskii, K.I.; Kozyrev, Yu.P.; Leonov, R.K.; Simagin, B.I.; Tsybin, A.S.; Shikanov, A.Ie.

    1986-03-01

    The paper describes a new device for generating pulsed neutron fields, utilized in nuclear geophysics for carrying out pulsed neutron logging and activation analysis under field conditions. The invention employs a sealed-off neutron tube with a laser ion source which increases neutron yield to the level of 10 neutrons per second or higher. 2 refs., 1 fig

  4. Signature Pedagogy in Theatre Arts

    Science.gov (United States)

    Kornetsky, Lisa

    2017-01-01

    Critique in undergraduate theatre programs is at the heart of training actors at all levels. It is accepted as the signature pedagogy and is practiced in multiple ways. This essay defines critique and presents the case for why it is used as the single most important way that performers come to understand the language, values, and discourse of the…

  5. Motif signatures of transcribed enhancers

    KAUST Repository

    Kleftogiannis, Dimitrios

    2017-09-14

    In mammalian cells, transcribed enhancers (TrEn) play important roles in the initiation of gene expression and maintenance of gene expression levels in spatiotemporal manner. One of the most challenging questions in biology today is how the genomic characteristics of enhancers relate to enhancer activities. This is particularly critical, as several recent studies have linked enhancer sequence motifs to specific functional roles. To date, only a limited number of enhancer sequence characteristics have been investigated, leaving space for exploring the enhancers genomic code in a more systematic way. To address this problem, we developed a novel computational method, TELS, aimed at identifying predictive cell type/tissue specific motif signatures. We used TELS to compile a comprehensive catalog of motif signatures for all known TrEn identified by the FANTOM5 consortium across 112 human primary cells and tissues. Our results confirm that distinct cell type/tissue specific motif signatures characterize TrEn. These signatures allow discriminating successfully a) TrEn from random controls, proxy of non-enhancer activity, and b) cell type/tissue specific TrEn from enhancers expressed and transcribed in different cell types/tissues. TELS codes and datasets are publicly available at http://www.cbrc.kaust.edu.sa/TELS.

  6. Quark-Gluon Plasma Signatures

    CERN Document Server

    Vogt, Ramona

    1998-01-01

    Aspects of quark-gluon plasma signatures that can be measured by CMS are discussed. First the initial conditions of the system from minijet production are introduced, including shadowing effects. Color screening of the Upsilon family is then presented, followed by energy loss effects on charm and bottom hadrons, high Pt jets and global observables.

  7. Galaxy interactions : The HI signature

    NARCIS (Netherlands)

    Sancisi, R; Barnes, JE; Sanders, DB

    1999-01-01

    HI observations are an excellent tool for investigating tidal interactions. Ongoing major and minor interactions which can lead to traumatic mergers or to accretion and the triggering of star formation, show distinct HI signatures. Interactions and mergers in the recent past can also be recognized

  8. Neutron scattering

    International Nuclear Information System (INIS)

    1991-02-01

    The annual report on hand gives an overview of the research work carried out in the Laboratory for Neutron Scattering (LNS) of the ETH Zuerich in 1990. Using the method of neutron scattering, it is possible to examine in detail the static and dynamic properties of the condensed material. In accordance with the multidisciplined character of the method, the LNS has for years maintained a system of intensive co-operation with numerous institutes in the areas of biology, chemistry, solid-state physics, crystallography and materials research. In 1990 over 100 scientists from more than 40 research groups both at home and abroad took part in the experiments. It was again a pleasure to see the number of graduate students present, who were studying for a doctorate and who could be introduced into the neutron scattering during their stay at the LNS and thus were in the position to touch on central ways of looking at a problem in their dissertation using this modern experimental method of solid-state research. In addition to the numerous and interesting ways of formulating the questions to explain the structure, nowadays the scientific programme increasingly includes particularly topical studies in connection with high temperature-supraconductors and materials research

  9. Neutron radiotherapy

    International Nuclear Information System (INIS)

    Thomas, F.J.

    1987-01-01

    The rationale for the application of neutron radiation for the treatment of malignancies is well established based on radiobiological studies. These factors include the presence of tissue hypoxia, radiation response as a function of cell cycle kinetics, the repair capacity of the malignant cells and the regeneration of malignant cells during a fractionated course of radiation. Despite the constraints under which the clinical trials to date have been conducted, promising results have been obtained. Randomized trials have demonstrated that neutron therapy is the treatment of choice for inoperable salivary gland carcinomas. A randomized trial of the RTOG has demonstrated a probable advantage for neutron radiation in the treatment of advanced prostate carcinomas but is yet to be confirmed. An improvement in local control has also been observed for selected sarcomas. Equivocal or contradictory results have been obtained for squamous cell carcinomas of the head and neck, bronchogenic carcinomas, advanced rectal, transitional cell carcinomas of the bladder and cervical carcinomas. The practical consequences of these radiobiological and clinical observations on the current generation of clinical trials is discussed

  10. Signatures of Extended Storage of Used Nuclear Fuel Comprehensive Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-21

    This report serves as a comprehensive overview of the Extended Storage of Used Nuclear Fuel work performed for the Material Protection, Accounting and Control Technologies campaign under the Department of Energy Office of Nuclear Energy. This paper describes a signature based on the source and fissile material distribution found within a population of used fuel assemblies combined with the neutron absorbers found within cask design that is unique to a specific cask with its specific arrangement of fuel. The paper describes all the steps used in producing and analyzing this signature from the beginning to the project end.

  11. High-Speed Interrogation for Large-Scale Fiber Bragg Grating Sensing.

    Science.gov (United States)

    Hu, Chenyuan; Bai, Wei

    2018-02-24

    A high-speed interrogation scheme for large-scale fiber Bragg grating (FBG) sensing arrays is presented. This technique employs parallel computing and pipeline control to modulate incident light and demodulate the reflected sensing signal. One Electro-optic modulator (EOM) and one semiconductor optical amplifier (SOA) were used to generate a phase delay to filter reflected spectrum form multiple candidate FBGs with the same optical path difference (OPD). Experimental results showed that the fastest interrogation delay time for the proposed method was only about 27.2 us for a single FBG interrogation, and the system scanning period was only limited by the optical transmission delay in the sensing fiber owing to the multiple simultaneous central wavelength calculations. Furthermore, the proposed FPGA-based technique had a verified FBG wavelength demodulation stability of ±1 pm without average processing.

  12. Wavelength interrogation of fiber Bragg grating sensors using tapered hollow Bragg waveguides.

    Science.gov (United States)

    Potts, C; Allen, T W; Azar, A; Melnyk, A; Dennison, C R; DeCorby, R G

    2014-10-15

    We describe an integrated system for wavelength interrogation, which uses tapered hollow Bragg waveguides coupled to an image sensor. Spectral shifts are extracted from the wavelength dependence of the light radiated at mode cutoff. Wavelength shifts as small as ~10  pm were resolved by employing a simple peak detection algorithm. Si/SiO₂-based cladding mirrors enable a potential operational range of several hundred nanometers in the 1550 nm wavelength region for a taper length of ~1  mm. Interrogation of a strain-tuned grating was accomplished using a broadband amplified spontaneous emission (ASE) source, and potential for single-chip interrogation of multiplexed sensor arrays is demonstrated.

  13. Characterization of a FBG sensor interrogation system based on a mode-locked laser scheme.

    Science.gov (United States)

    Madrigal, Javier; Fraile-Peláez, Francisco Javier; Zheng, Di; Barrera, David; Sales, Salvador

    2017-10-02

    This paper is focused on the characterization of a fiber Bragg grating (FBG) sensor interrogation system based on a fiber ring laser with a semiconductor optical amplifier as the gain medium, and an in-loop electro-optical modulator. This system operates as a switchable active (pulsed) mode-locked laser. The operation principle of the system is explained theoretically and validated experimentally. The ability of the system to interrogate an array of different FBGs in wavelength and spatial domain is demonstrated. Simultaneously, the influence of several important parameters on the performance of the interrogation technique has been investigated. Specifically, the effects of the bandwidth and the reflectivity of the FBGs, the SOA gain, and the depth of the intensity modulation have been addressed.

  14. Interrogation in Teacher-Student Interaction in Bahasa Indonesia Learning at Elementary School

    Directory of Open Access Journals (Sweden)

    Akmal Hamsa

    2014-08-01

    Full Text Available Interrogation in Teacher-Student Interaction in Bahasa Indonesia Learning at Elementary School. This study aimed to describe the form, function, and questioning strategies teachers in teacher-student interrogation in Bahasa Indonesia learning in elementary school. Data sourced from four teacher of elementary school, SDN Tamangapa and SD Inpres Tamangapa. Data were obtained by (1 recording, (2 documentation, (3 field notes, (4 interview. The results showed that: (1 the form of questioning the teacher in the teacher-student interaction in Bahasa Indonesia learning in primary schools generally examined the low-level thinking skills, (2 functions of teacher questions are generally intended to check student understanding, and (3 teachers utilize a variety of strategies in addressing student answers correctly and the apparent hesitation. Some disadvantages are indicated teachers in providing interrogation.

  15. Prosodic differences between declaratives and interrogatives in infant-directed speech.

    Science.gov (United States)

    Geffen, Susan; Mintz, Toben H

    2017-07-01

    In many languages, declaratives and interrogatives differ in word order properties, and in syntactic organization more broadly. Thus, in order to learn the distinct syntactic properties of the two sentence types, learners must first be able to distinguish them using non-syntactic information. Prosodic information is often assumed to be a useful basis for this type of discrimination, although no systematic studies of the prosodic cues available to infants have been reported. Analysis of maternal speech in three Standard American English-speaking mother-infant dyads found that polar interrogatives differed from declaratives on the patterning of pitch and duration on the final two syllables, but wh-questions did not. Thus, while prosody is unlikely to aid discrimination of declaratives from wh-questions, infant-directed speech provides prosodic information that infants could use to distinguish declaratives and polar interrogatives. We discuss how learners could leverage this information to identify all question forms, in the context of syntax acquisition.

  16. The interrogation decision-making model: A general theoretical framework for confessions.

    Science.gov (United States)

    Yang, Yueran; Guyll, Max; Madon, Stephanie

    2017-02-01

    This article presents a new model of confessions referred to as the interrogation decision-making model . This model provides a theoretical umbrella with which to understand and analyze suspects' decisions to deny or confess guilt in the context of a custodial interrogation. The model draws upon expected utility theory to propose a mathematical account of the psychological mechanisms that not only underlie suspects' decisions to deny or confess guilt at any specific point during an interrogation, but also how confession decisions can change over time. Findings from the extant literature pertaining to confessions are considered to demonstrate how the model offers a comprehensive and integrative framework for organizing a range of effects within a limited set of model parameters. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. Promotion COPERNIC Energy and Society the interrogations on the world demand evolution

    International Nuclear Information System (INIS)

    2001-12-01

    In the framework of a prospective reflexion emergence on the energy demand, this document presents an analysis of the prospective approach and of recent studies: challenges, interests, limits, validity of the models and hypothesis and results relevance. With this analysis, the authors aim to identify the main interrogations bond to the world energy demand evolution. They then analyse these interrogations in the framework of a sectoral approach (agriculture, industry, transports, residential) in order to detail the demand and to forecast the evolution. Facing the consumption attitudes, they also suggest some new action avenues to favor a sustainable growth. (A.L.B.)

  18. Perioperative Interrogation of St. Jude Cardiovascular Implantable Electronic Devices: A Guide for Anesthesiologists.

    Science.gov (United States)

    Cronin, Brett; Essandoh, Michael K

    2018-04-01

    Feelings of trepidation or uncertainty regarding cardiovascular implantable electronic devices (CIEDs) in the perioperative period can often be mitigated by a thorough knowledge of societal recommendations, recommended management options, and familiarity with CIEDs. Given that effective interpretation of an interrogation report is vital to determining perioperative management options and applying societal recommendations, the creation and interpretation of St. Jude CIED interrogation reports are discussed. In an effort to increase the familiarity with St. Jude transvenous CIEDs amongst anesthesiologists, basic programming of a St. Jude pacemaker and implantable cardioverter defibrillator (ICD) also are described. Published by Elsevier Inc.

  19. Compact, low-cost, and high-resolution interrogation unit for optical sensors

    International Nuclear Information System (INIS)

    Kiesel, Peter; Schmidt, Oliver; Mohta, Setu; Johnson, Noble; Malzer, Stefan

    2006-01-01

    Compact wavelength detectors that resolve wavelength changes in the subpicometer range over a broad spectral range are presented. A photodiode array or position sensor device is coated with a linear variable filter that converts the wavelength of the incident light into a spatial intensity distribution. The centroid of the spatial distribution is determined by a differential readout of the two elements of the photodiode array or the position sensor device. The device can interrogate any optical sensor that produces a wavelength shift in response to a stimulus. The potential of this device was tested by interrogating fiber-Bragg-grating sensors

  20. Interrogation of weak Bragg grating sensors based on dual-wavelength differential detection.

    Science.gov (United States)

    Cheng, Rui; Xia, Li

    2016-11-15

    It is shown that for weak Bragg gratings the logarithmic ratio of reflected intensities at any two wavelengths within the spectrum follows a linear relationship with the Bragg wavelength shift, with a slope proportional to their wavelength spacing. This finding is exploited to develop a flexible, efficient, and cheap interrogation solution of weak fiber Bragg grating (FBGs), especially ultra-short FBGs, in distributed sensing based on dual-wavelength differential detection. The concept is experimentally studied in both single and distributed sensing systems with ultra-short FBG sensors. The work may form the basis of new and promising FBG interrogation techniques based on detecting discrete rather than continuous spectra.

  1. Spectral Doppler interrogation of the patent foramen ovale-a window to left heart hemodynamics.

    Science.gov (United States)

    Fadel, Bahaa M; Husain, Aysha; Bakarman, Hatem; Dahdouh, Ziad; Salvo, Giovanni Di; Mohty, Dania

    2015-02-01

    Spectral Doppler interrogation of flow across a patent foramen ovale (PFO) allows recording of the instantaneous pressure gradient between left and right atrium (RA). The assessment of RA pressure using the size and collapsibility of the inferior vena cava would thus allow estimation of left atrial (LA) pressure. In this article, we illustrate the value of spectral Doppler interrogation of flow across the PFO by transthoracic echocardiography as a novel and simple tool for the assessment of LA pressure and left cardiac hemodynamics in addition to the conventional noninvasive parameters. © 2014, Wiley Periodicals, Inc.

  2. High-Efficiency Quantum Interrogation Measurements via the Quantum Zeno Effect

    International Nuclear Information System (INIS)

    Kwiat, P. G.; White, A. G.; Mitchell, J. R.; Nairz, O.; Weihs, G.; Weinfurter, H.; Zeilinger, A.

    1999-01-01

    The phenomenon of quantum interrogation allows one to optically detect the presence of an absorbing object, without the measuring light interacting with it. In an application of the quantum Zeno effect, the object inhibits the otherwise coherent evolution of the light, such that the probability that an interrogating photon is absorbed can in principle be arbitrarily small. We have implemented this technique, achieving efficiencies of up to 73% , and consequently exceeding the 50% theoretical maximum of the original ''interaction-free'' measurement proposal. We have also predicted and experimentally verified a previously unsuspected dependence on loss. (c) 1999 The American Physical Society

  3. The relationship between criminal conviction and interrogative suggestibility among delinquent boys.

    Science.gov (United States)

    Gudjonsson, G H; Singh, K K

    1984-03-01

    This study investigates the relationship between interrogative suggestibility, as measured by the Gudjonsson Suggestibility Scale (GSS), and number of previous convictions among 35 delinquent boys. The GSS measures two independent aspects of suggestibility. First, the extent to which subjects give in to suggestive questions. Second, the extent to which subjects give in to interpersonal pressure given in the form of critical feedback about test performance. The number of convictions were found to correlate negatively with the latter aspect of interrogative suggestibility, but not significantly with the former.

  4. Long fiber Bragg grating sensor interrogation using discrete-time microwave photonic filtering techniques.

    Science.gov (United States)

    Ricchiuti, Amelia Lavinia; Barrera, David; Sales, Salvador; Thevenaz, Luc; Capmany, José

    2013-11-18

    A novel technique for interrogating photonic sensors based on long fiber Bragg gratings (FBGs) is presented and experimentally demonstrated, dedicated to detect the presence and the precise location of several spot events. The principle of operation is based on a technique used to analyze microwave photonics (MWP) filters. The long FBGs are used as quasi-distributed sensors. Several hot-spots can be detected along the FBG with a spatial accuracy under 0.5 mm using a modulator and a photo-detector (PD) with a modest bandwidth of less than 1 GHz. The proposed interrogation system is intrinsically robust against environmental changes.

  5. On the actual bandwidth of some dynamic fiber optic strain/temperature interrogators

    Science.gov (United States)

    Preizler, Rotem R.; Davidi, R.; Motil, Avi; Botsev, Yakov; Hahami, Meir; Tur, Moshe

    2017-04-01

    The measurement accuracy of dynamic fiber-optic sensing interrogators, which use frequency scanning to determine the value of the measured, err as either the event bandwidth approaches half the instrument sampling frequency or when the event dynamic range comes close to the instrument designed value. One main source of error is the common practice of assigning sampling at a non-uniform grid to a uniform one. Harmonics higher than -20 dB are observed for signal frequencies exceeding 25% of the sampling rate and/or for signal amplitudes higher than 15% of the instrument dynamic range. These findings have applications to fiber-Bragg-grating and Brillouin interrogators.

  6. A metabolic signature of long life in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Viney Jonathan M

    2010-02-01

    Full Text Available Abstract Background Many Caenorhabditis elegans mutations increase longevity and much evidence suggests that they do so at least partly via changes in metabolism. However, up until now there has been no systematic investigation of how the metabolic networks of long-lived mutants differ from those of normal worms. Metabolomic technologies, that permit the analysis of many untargeted metabolites in parallel, now make this possible. Here we use one of these, 1H nuclear magnetic resonance spectroscopy, to investigate what makes long-lived worms metabolically distinctive. Results We examined three classes of long-lived worms: dauer larvae, adult Insulin/IGF-1 signalling (IIS-defective mutants, and a translation-defective mutant. Surprisingly, these ostensibly different long-lived worms share a common metabolic signature, dominated by shifts in carbohydrate and amino acid metabolism. In addition the dauer larvae, uniquely, had elevated levels of modified amino acids (hydroxyproline and phosphoserine. We interrogated existing gene expression data in order to integrate functional (metabolite-level changes with transcriptional changes at a pathway level. Conclusions The observed metabolic responses could be explained to a large degree by upregulation of gluconeogenesis and the glyoxylate shunt as well as changes in amino acid catabolism. These responses point to new possible mechanisms of longevity assurance in worms. The metabolic changes observed in dauer larvae can be explained by the existence of high levels of autophagy leading to recycling of cellular components. See associated minireview: http://jbiol.com/content/9/1/7

  7. Unique proteomic signatures distinguish macrophages and dendritic cells.

    Directory of Open Access Journals (Sweden)

    Lev Becker

    Full Text Available Monocytes differentiate into heterogeneous populations of tissue macrophages and dendritic cells (DCs that regulate inflammation and immunity. Identifying specific populations of myeloid cells in vivo is problematic, however, because only a limited number of proteins have been used to assign cellular phenotype. Using mass spectrometry and bone marrow-derived cells, we provided a global view of the proteomes of M-CSF-derived macrophages, classically and alternatively activated macrophages, and GM-CSF-derived DCs. Remarkably, the expression levels of half the plasma membrane proteins differed significantly in the various populations of cells derived in vitro. Moreover, the membrane proteomes of macrophages and DCs were more distinct than those of classically and alternatively activated macrophages. Hierarchical cluster and dual statistical analyses demonstrated that each cell type exhibited a robust proteomic signature that was unique. To interrogate the phenotype of myeloid cells in vivo, we subjected elicited peritoneal macrophages harvested from wild-type and GM-CSF-deficient mice to mass spectrometric and functional analysis. Unexpectedly, we found that peritoneal macrophages exhibited many features of the DCs generated in vitro. These findings demonstrate that global analysis of the membrane proteome can help define immune cell phenotypes in vivo.

  8. Spallation Neutron Source (SNS)

    Data.gov (United States)

    Federal Laboratory Consortium — The SNS at Oak Ridge National Laboratory is a next-generation spallation neutron source for neutron scattering that is currently the most powerful neutron source in...

  9. Bulk media assay using backscattered Pu-Be neutrons

    CERN Document Server

    Csikai, J

    1999-01-01

    Spectral yields of elastically backscattered Pu-Be neutrons measured for graphite, water, polyethylene, liquid nitrogen, paraffin oil, SiO sub 2 , Al, Fe, and Pb slabs show a definite correlation with the energy dependence of the elastic scattering cross sections, sigma sub E sub L (E sub n). The C, N and O can be identified by the different structures in their sigma sub E sub L (E sub n) functions. The integrated spectral yields versus thickness exhibit saturation for each sample. The interrogated volume is limited by the presence of hydrogen in the sample. (author)

  10. Online Signature Verification on MOBISIG Finger-Drawn Signature Corpus

    Directory of Open Access Journals (Sweden)

    Margit Antal

    2018-01-01

    Full Text Available We present MOBISIG, a pseudosignature dataset containing finger-drawn signatures from 83 users captured with a capacitive touchscreen-based mobile device. The database was captured in three sessions resulting in 45 genuine signatures and 20 skilled forgeries for each user. The database was evaluated by two state-of-the-art methods: a function-based system using local features and a feature-based system using global features. Two types of equal error rate computations are performed: one using a global threshold and the other using user-specific thresholds. The lowest equal error rate was 0.01% against random forgeries and 5.81% against skilled forgeries using user-specific thresholds that were computed a posteriori. However, these equal error rates were significantly raised to 1.68% (random forgeries case and 14.31% (skilled forgeries case using global thresholds. The same evaluation protocol was performed on the DooDB publicly available dataset. Besides verification performance evaluations conducted on the two finger-drawn datasets, we evaluated the quality of the samples and the users of the two datasets using basic quality measures. The results show that finger-drawn signatures can be used by biometric systems with reasonable accuracy.

  11. Unsupervised signature extraction from forensic logs

    NARCIS (Netherlands)

    Thaler, S.M.; Menkovski, V.; Petkovic, M.; Altun, Y.; Das, K.; Mielikäinen, T.; Malerba, D.; Stefanowski, J.; Read, J.; Žitnik, M.; Ceci, M.

    2017-01-01

    Signature extraction is a key part of forensic log analysis. It involves recognizing patterns in log lines such that log lines that originated from the same line of code are grouped together. A log signature consists of immutable parts and mutable parts. The immutable parts define the signature, and

  12. 7 CFR 718.9 - Signature requirements.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Signature requirements. 718.9 Section 718.9... MULTIPLE PROGRAMS General Provisions § 718.9 Signature requirements. (a) When a program authorized by this chapter or Chapter XIV of this title requires the signature of a producer; landowner; landlord; or tenant...

  13. 42 CFR 424.36 - Signature requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Signature requirements. 424.36 Section 424.36... (CONTINUED) MEDICARE PROGRAM CONDITIONS FOR MEDICARE PAYMENT Claims for Payment § 424.36 Signature requirements. (a) General rule. The beneficiary's own signature is required on the claim unless the beneficiary...

  14. 17 CFR 12.12 - Signature.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Signature. 12.12 Section 12.12... General Information and Preliminary Consideration of Pleadings § 12.12 Signature. (a) By whom. All... document on behalf of another person. (b) Effect. The signature on any document of any person acting either...

  15. 25 CFR 213.10 - Lessor's signature.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Lessor's signature. 213.10 Section 213.10 Indians BUREAU... MEMBERS OF FIVE CIVILIZED TRIBES, OKLAHOMA, FOR MINING How to Acquire Leases § 213.10 Lessor's signature... thumbprint which shall be designated as “right” or “left” thumbmark. Such signatures must be witnessed by two...

  16. Signature effects in 2-qp rotational bands

    International Nuclear Information System (INIS)

    Jain, A.K.; Goel, A.

    1992-01-01

    The authors briefly review the progress in understanding the 2-qp rotational bands in odd-odd nuclei. Signature effects and the phenomenon of signature inversion are discussed. The Coriolis coupling appears to have all the ingredients to explain the inversion. Some recent work on signature dependence in 2-qp bands of even-even nuclei is also discussed; interesting features are pointed out

  17. 27 CFR 17.6 - Signature authority.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Signature authority. 17.6... PRODUCTS General Provisions § 17.6 Signature authority. No claim, bond, tax return, or other required... other proper notification of signature authority has been filed with the TTB office where the required...

  18. High-speed high-security signatures

    NARCIS (Netherlands)

    Bernstein, D.J.; Duif, N.; Lange, T.; Schwabe, P.; Yang, B.Y.

    2011-01-01

    This paper shows that a $390 mass-market quad-core 2.4GHz Intel Westmere (Xeon E5620) CPU can create 108000 signatures per second and verify 71000 signatures per second on an elliptic curve at a 2128 security level. Public keys are 32 bytes, and signatures are 64 bytes. These performance figures

  19. High energy neutron radiography

    International Nuclear Information System (INIS)

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-01-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos

  20. Neutron scattering. Lectures

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: Neutron sources, neutron properties and elastic scattering, correlation functions measured by scattering experiments, symmetry of crystals, applications of neutron scattering, polarized-neutron scattering and polarization analysis, structural analysis, magnetic and lattice excitation studied by inelastic neutron scattering, macromolecules and self-assembly, dynamics of macromolecules, correlated electrons in complex transition-metal oxides, surfaces, interfaces, and thin films investigated by neutron reflectometry, nanomagnetism. (HSI)