Trellis and turbo coding iterative and graph-based error control coding

CERN Document Server

Schlegel, Christian B

2015-01-01

This new edition has been extensively revised to reflect the progress in error control coding over the past few years. Over 60% of the material has been completely reworked, and 30% of the material is original. Convolutional, turbo, and low density parity-check (LDPC) coding and polar codes in a unified framework. Advanced research-related developments such as spatial coupling. A focus on algorithmic and implementation aspects of error control coding.

Study on 3D gamma-ray imaging for medical diagnosis with coded aperture

International Nuclear Information System (INIS)

Horiki, Kazunari; Shimazoe, Kenji; Ohno, Masashi; Takahashi, Hiroyuki; Kobashi, Keiji; Moro, Eiji

2014-01-01

The conventional methods for medical imaging have several disadvantages such as restriction on the energy and detection efficiency. Coded aperture imaging can be used for medical imagings without restriction on the energy, which makes it possible to use multiple tracers in diagnosis. The detection efficiency of Coded aperture imaging is ten times better than that of the pinhole collimator. First, simulations of the coded aperture imaging have been done to confirm M-array's effectiveness. Second, two experiments have been done with low-energy gamma-ray (122 keV( 57 Co)) and with high-energy gamma-ray (662 keV( 137 Cs)). In both cases reconstructed image was successfully acquired. The measured spatial resolution in the experiment using 57 Co is 4.3 mm (FWHM). (author)

Tri-code inductance control rod position indicator with several multi-coding-bars

International Nuclear Information System (INIS)

Shi Jibin; Jiang Yueyuan; Wang Wenran

2004-01-01

A control rod position indicator named as tri-code inductance control rod position indicator with multi-coding-bars, which possesses simple structure, reliable operation and high precision, is developed. The detector of the indicator is composed of K coils, a compensatory coil and K coding bars. Each coding bar consists of several sections of strong magnetic cores, several sections of weak magnetic cores and several sections of non-magnetic portions. As the control rod is withdrawn, the coding bars move in the center of the coils respectively, while the constant alternating current passes the coils and makes them to create inductance alternating voltage signals. The outputs of the coils are picked and processed, and the tri-codes indicating rod position can be gotten. Moreover, the coding principle of the detector and its related structure are introduced. The analysis shows that the indicator owns more advantage over the coils-coding rod position indicator, so it can meet the demands of the rod position indicating in nuclear heating reactor (NHR). (authors)

APPLE-2: an improved version of APPLE code for plotting neutron and gamma ray spectra and reaction rates

International Nuclear Information System (INIS)

Kawasaki, Hiromitsu; Seki, Yasushi.

1982-07-01

A computer code APPLE-2 which plots the spatial distribution of energy spectra of multi-group neutron and/or gamma ray fluxes, and reaction rates has been developed. This code is an improved version of the previously developed APPLE code and has the following features: (1) It plots energy spectra of neutron and/or gamma ray fluxes calculated by ANISN, DOT and MORSE. (2) It calculates and plots the spatial distribution of neutron and gamma ray fluxes and various types of reaction rates such as nuclear heating rates, operational dose rates, displacement damage rates. (3) Input data specification is greatly simplified by the use of standard, response libraries and by close coupling with radiation transport calculation codes. (4) Plotting outputs are given in camera ready form. (author)

Modelling plastic scintillator response to gamma rays using light transport incorporated FLUKA code

Energy Technology Data Exchange (ETDEWEB)

Ranjbar Kohan, M. [Physics Department, Tafresh University, Tafresh (Iran, Islamic Republic of); Etaati, G.R. [Department of Nuclear Engineering and Physics, Amir Kabir University of Technology, Tehran (Iran, Islamic Republic of); Ghal-Eh, N., E-mail: ghal-eh@du.ac.ir [School of Physics, Damghan University, Damghan (Iran, Islamic Republic of); Safari, M.J. [Department of Energy Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Afarideh, H. [Department of Nuclear Engineering and Physics, Amir Kabir University of Technology, Tehran (Iran, Islamic Republic of); Asadi, E. [Department of Physics, Payam-e-Noor University, Tehran (Iran, Islamic Republic of)

2012-05-15

The response function of NE102 plastic scintillator to gamma rays has been simulated using a joint FLUKA+PHOTRACK Monte Carlo code. The multi-purpose particle transport code, FLUKA, has been responsible for gamma transport whilst the light transport code, PHOTRACK, has simulated the transport of scintillation photons through scintillator and lightguide. The simulation results of plastic scintillator with/without light guides of different surface coverings have been successfully verified with experiments. - Highlights: Black-Right-Pointing-Pointer A multi-purpose code (FLUKA) and a light transport code (PHOTRACK) have been linked. Black-Right-Pointing-Pointer The hybrid code has been used to generate the response function of an NE102 scintillator. Black-Right-Pointing-Pointer The simulated response functions exhibit a good agreement with experimental data.

Next generation Zero-Code control system UI

CERN Multimedia

CERN. Geneva

2017-01-01

Developing ergonomic user interfaces for control systems is challenging, especially during machine upgrade and commissioning where several small changes may suddenly be required. Zero-code systems, such as *Inspector*, provide agile features for creating and maintaining control system interfaces. More so, these next generation Zero-code systems bring simplicity and uniformity and brake the boundaries between Users and Developers. In this talk we present *Inspector*, a CERN made Zero-code application development system, and we introduce the major differences and advantages of using Zero-code control systems to develop operational UI.

Deciphering the genetic regulatory code using an inverse error control coding framework.

Energy Technology Data Exchange (ETDEWEB)

Rintoul, Mark Daniel; May, Elebeoba Eni; Brown, William Michael; Johnston, Anna Marie; Watson, Jean-Paul

2005-03-01

We have found that developing a computational framework for reconstructing error control codes for engineered data and ultimately for deciphering genetic regulatory coding sequences is a challenging and uncharted area that will require advances in computational technology for exact solutions. Although exact solutions are desired, computational approaches that yield plausible solutions would be considered sufficient as a proof of concept to the feasibility of reverse engineering error control codes and the possibility of developing a quantitative model for understanding and engineering genetic regulation. Such evidence would help move the idea of reconstructing error control codes for engineered and biological systems from the high risk high payoff realm into the highly probable high payoff domain. Additionally this work will impact biological sensor development and the ability to model and ultimately develop defense mechanisms against bioagents that can be engineered to cause catastrophic damage. Understanding how biological organisms are able to communicate their genetic message efficiently in the presence of noise can improve our current communication protocols, a continuing research interest. Towards this end, project goals include: (1) Develop parameter estimation methods for n for block codes and for n, k, and m for convolutional codes. Use methods to determine error control (EC) code parameters for gene regulatory sequence. (2) Develop an evolutionary computing computational framework for near-optimal solutions to the algebraic code reconstruction problem. Method will be tested on engineered and biological sequences.

Development of the neutron-transport code TransRay and studies on the two- and three-dimensional calculation of effective group cross sections; Entwicklung des Neutronentransportcodes TransRay und Untersuchungen zur zwei- und dreidimensionalen Berechnung effektiver Gruppenwirkungsquerschnitte

Energy Technology Data Exchange (ETDEWEB)

Beckert, C.

2007-12-19

Conventionally the data preparation of the neutron cross sections for reactor-core calculations pursues with 2D cell codes. Aim of this thesis was, to develop a 3D cell code, to study with this code 3D effects, and to evaluate the necessarity of a 3D data preparation of the neutron cross sections. For the calculation of the neutron transport the method of the first-collision probabilities, which are calculated with the ray-tracing method, was chosen. The mathematical algorithms were implemented in the 2D/3D cell code TransRay. For the geometry part of the program the geometry module of a Monte Carlo code was used.The ray tracing in 3D was parallelized because of the high computational time. The program TransRay was verified on 2D test problems. For a reference pressured-water reactor following 3D problems were studied: A partly immersed control rod and void (vacuum or steam) around a fuel rod as model of a steam void. All problems were for comparison calculated also with the programs HELIOS(2D) and MCNP(3D). The dependence of the multiplication factor and the averaged two-group cross section on the immersion depth of the control rod respectively of the height of the steam void were studied. The 3D-calculated two-group cross sections were compared with three conventional approximations: Linear interpolation, interpolation with flux weighting, and homogenization, At the 3D problem of the control rod it was shown that the interpolation with flux weighting is a good approximation. Therefore here a 3D data preparation is not necessary. At the test case of the single control rod, which is surrounded by the void, the three approximation for the two-group cross sections were proved as unsufficient. Therefore a 3D data preparation is necessary. The single fuel-rod cell with void can be considered as the limiting case of a reactor, in which a phase interface has been formed. [German] Standardmaessig erfolgt die Datenaufbereitung der Neutronenwirkungsquerschnitte fuer

Modification of an x-ray diffraction unit to comply with the NH and MRC code of practice

International Nuclear Information System (INIS)

Ibbetson, V.J.; Young, J.G.

2004-01-01

X-ray analysis units are commonly used in research and industrial laboratories throughout Australia. Despite a well-established Code of Practice and working protocols for the safe use of such units, there are all too many stories of users by-passing safety features significantly increasing the risk of accidental exposure to the primary X-ray beam. Since the output of such units may be as high as 300 Gy x s 1 , such accidental exposures could have very serious consequences. Australian Radiation Services Pty Ltd undertook a compliance audit of an X-ray diffraction unit with respect to the NH and MRC Code of Practice for protection against ionising radiation emitted from X-ray analysis equipment. This paper discusses the findings from the initial inspection and the modifications recommended for the XRD unit to ensure compliance with the Code, without unnecessarily restricting its use. Copyright (2004) Australasian Radiation Protection Society Inc

Delin and Delog codes for graphic representation of gamma ray spectra

International Nuclear Information System (INIS)

Travesi, A.; Romero, L.

1983-01-01

Two FORTRAN IV Codes have been developed for graphic representation of the gamma-ray spectra obtained with GeLi detectors and multichannel analyzers. The graphic plotting is carried out with the H.P. Graphic Plotter Mod HP-7221 A, using the graphic package software GRAPHICS-1000 from Hewlett-Packard. The codes have a great versatility and the representation of gamma spectra can be done in a lineal, semilog, or log-log scale, as desired. The gamma ray spectra data are fed into the computer through magnetic tape or perforated paper tape. The different output options and complementary data are given in a conversational way through a terminal with TV display. Among the options that can be selected by the user are the following: 1) smoothing the spectra; 2) drawing the spectra point by point or continuous; 3) output drawing in 1, 2 or 4 sheets with automatic division of the energy scale; 4) overlapping of selected spectra regions in γ-scale ampliation with automatic printout of the region limits and ampliation factor; 5) printing spectra data and identifications of selected photopeaks. The codes can be employed with any computer using printing devices, HP-GRAPHICS 1000 software compatible, but are easily modified for another printing software since their modular structure with FORTRAN IV written subroutines. (author)

DELIN and DELOG codes for graphic representation of gamma ray spectra

International Nuclear Information System (INIS)

Romero, L.; Travesi, A.

1983-01-01

Two Fortran IV Codes has been developed for graphic representation of the gamma-ray spectra obtained with Ge Li detectors and multichannel analyzers. The grafic plotting es carried out with the H.P. Graphic Plotter Mod HP-7221 A, using the graphic package software GRAPHICS-1000 from Hewlett-Packard. The codes have a great versatility and the representation of gamma spectra can ba done in a lineal, semi log, or log-log scale, as desired. The gamma ray spectra data are feed into the computer through magnetic tape or perfored paper tape. The different out-put options and complementary data are given in a conversational way through a terminal with T.V. displays. Among the options that can be selected by the user are the following: - smoothing the spectra - drawing the spectra point by point or continuous - out-put drawing an 1, 2, or 4 sheet with automatic division of the energy scale. - overlapping of selected spectra regions in Y scale ampliation with automatic print-out of the region limits and ampliation factor. - Printing spectra data and identifications of selected photo peaks. The codes can be employed with any computer using printing devices, HP-Graphics 1000 software compatible, but are easily modified for another printing software since their modular structure with Fortran IV written

SimProp: a simulation code for ultra high energy cosmic ray propagation

International Nuclear Information System (INIS)

Aloisio, R.; Grillo, A.F.; Boncioli, D.; Petrera, S.; Salamida, F.

2012-01-01

A new Monte Carlo simulation code for the propagation of Ultra High Energy Cosmic Rays is presented. The results of this simulation scheme are tested by comparison with results of another Monte Carlo computation as well as with the results obtained by directly solving the kinetic equation for the propagation of Ultra High Energy Cosmic Rays. A short comparison with the latest flux published by the Pierre Auger collaboration is also presented

A versatile ray-tracing code for studying rf wave propagation in toroidal magnetized plasmas

International Nuclear Information System (INIS)

Peysson, Y; Decker, J; Morini, L

2012-01-01

A new ray-tracing code named C3PO has been developed to study the propagation of arbitrary electromagnetic radio-frequency (rf) waves in magnetized toroidal plasmas. Its structure is designed for maximum flexibility regarding the choice of coordinate system and dielectric model. The versatility of this code makes it particularly suitable for integrated modeling systems. Using a coordinate system that reflects the nested structure of magnetic flux surfaces in tokamaks, fast and accurate calculations inside the plasma separatrix can be performed using analytical derivatives of a spline-Fourier interpolation of the axisymmetric toroidal MHD equilibrium. Applications to reverse field pinch magnetic configuration are also included. The effects of 3D perturbations of the axisymmetric toroidal MHD equilibrium, due to the discreteness of the magnetic coil system or plasma fluctuations in an original quasi-optical approach, are also studied. Using a Runge–Kutta–Fehlberg method for solving the set of ordinary differential equations, the ray-tracing code is extensively benchmarked against analytical models and other codes for lower hybrid and electron cyclotron waves. (paper)

MMAPDNG: A new, fast code backed by a memory-mapped database for simulating delayed γ-ray emission with MCNPX package

Science.gov (United States)

Lou, Tak Pui; Ludewigt, Bernhard

2015-09-01

The simulation of the emission of beta-delayed gamma rays following nuclear fission and the calculation of time-dependent energy spectra is a computational challenge. The widely used radiation transport code MCNPX includes a delayed gamma-ray routine that is inefficient and not suitable for simulating complex problems. This paper describes the code "MMAPDNG" (Memory-Mapped Delayed Neutron and Gamma), an optimized delayed gamma module written in C, discusses usage and merits of the code, and presents results. The approach is based on storing required Fission Product Yield (FPY) data, decay data, and delayed particle data in a memory-mapped file. When compared to the original delayed gamma-ray code in MCNPX, memory utilization is reduced by two orders of magnitude and the ray sampling is sped up by three orders of magnitude. Other delayed particles such as neutrons and electrons can be implemented in future versions of MMAPDNG code using its existing framework.

Computer code for qualitative analysis of gamma-ray spectra

International Nuclear Information System (INIS)

Yule, H.P.

1979-01-01

Computer code QLN1 provides complete analysis of gamma-ray spectra observed with Ge(Li) detectors and is used at both the National Bureau of Standards and the Environmental Protection Agency. It locates peaks, resolves multiplets, identifies component radioisotopes, and computes quantitative results. The qualitative-analysis (or component identification) algorithms feature thorough, self-correcting steps which provide accurate isotope identification in spite of errors in peak centroids, energy calibration, and other typical problems. The qualitative-analysis algorithm is described in this paper

Computer code for shielding calculations of x-rays rooms

International Nuclear Information System (INIS)

Affonso, R.R.W.; Borges, D. da S.; Lava, D.D.; Moreira, M. de L.; Guimarães, A.C.F.

2015-01-01

The building an effective barrier against ionizing radiation present in radiographic rooms requires consideration of many variables. The methodology used for thickness specification of primary and secondary, barrier of a traditional radiographic room, considers the following factors: Use Factor, Occupational Factor, distance between the source and the wall, Workload, Kerma in the air and distance between the patient and the source. With these data it was possible to develop a computer code, which aims to identify and use variables in functions obtained through graphics regressions provided by NCRP-147 (Structural Shielding Design for Medical X-Ray Imaging Facilities) report, for shielding calculation of room walls, and the walls of the dark room and adjacent areas. With the implemented methodology, it was made a code validation by comparison of results with a study case provided by the report. The obtained values for thickness comprise different materials such as concrete, lead and glass. After validation it was made a case study of an arbitrary radiographic room.The development of the code resulted in a user-friendly tool for planning radiographic rooms to comply with the limits established by CNEN-NN-3:01 published in september/2011. (authors)

Comparison of three gamma ray isotopic determination codes: FRAM, MGA, and TRIFID

International Nuclear Information System (INIS)

Cremers, T.L.; Malcom, J.E.; Bonner, C.A.

1994-01-01

The determination of the isotopic distribution of plutonium and the americium concentration is required for the assay of nuclear material by calorimetry or neutron coincidence counting. The isotopic information is used in calorimetric assay to compute the effective specific power from the measured isotopic fractions and the known specific power of each isotope. The effective specific power is combined with the heat measurement to obtain the mass of plutonium in the assayed nuclear material. The response of neutron coincidence counters is determined by the 240 Pu isotopic fraction with contributions from the other even plutonium isotopes. The effect of the 240 Pu isotopic fraction and the other neutron contributing isotopes are combined as 240 Pu effective. This is used to calculate the mass of nuclear material from the neutron counting data in a manner analogous to the effective specific power in calorimeter. Comparisons of the precision and accuracy of calorimetric assay and neutron coincidence counting often focus only on the precision and accuracy of the heat measurement (calorimetry) compared to the precision and accuracy of the neutron coincidence counting statistics. The major source of uncertainty for both calorimetric assay and neutron coincidence counting often lies in the determination of the plutonium isotopic distribution ad determined by gamma ray spectroscopy. Thus, the selection of the appropriate isotopic distribution code is of paramount importance to good calorimetric assay and neutron coincidence counting. Three gamma ray isotopic distribution codes, FRAM, MGA, and TRIFID have been compared at the Los Alamos Plutonium Facility under carefully controlled conditions of similar count rates, count times, and 240 Pu isotopic fraction

Optimum design of a coded mask X-ray telescope for rocket applications

International Nuclear Information System (INIS)

Gunson, J.; Polychronopulos, B.

1976-01-01

A review of the principles of current X-ray telescopes is made with particular emphasis on two-step imaging techniques involving coding masks. The merits and limitations of the various types of coding masks in use are examined in detail. The limitations are shown to arise from the finite nature of practical masks. By postulating periodicity, 'optimum masks' can be constructed with ideal imaging qualities. The theory for the design of such masks and the practical considerations involved in the design of a rocket-borne X-ray telescope system are discussed in full, with particular attention paid to resolution, field of view and image noise. The main emphasis throughout the paper is on one-dimensional masks but two-dimensional masks are also studied. It is concluded that optimum masks could prove very valuable in astronomical applications and also in other fields such as radiography, where high imaging quality coupled with high sensitivity and low cost are of utmost importance. (author)

Design and performance of coded aperture optical elements for the CESR-TA x-ray beam size monitor

Energy Technology Data Exchange (ETDEWEB)

Alexander, J.P.; Chatterjee, A.; Conolly, C.; Edwards, E.; Ehrlichman, M.P. [Cornell University, Ithaca, NY 14853 (United States); Flanagan, J.W. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Department of Accelerator Science, Graduate University for Advanced Studies (SOKENDAI), Tsukuba (Japan); Fontes, E. [Cornell University, Ithaca, NY 14853 (United States); Heltsley, B.K., E-mail: bkh2@cornell.edu [Cornell University, Ithaca, NY 14853 (United States); Lyndaker, A.; Peterson, D.P.; Rider, N.T.; Rubin, D.L.; Seeley, R.; Shanks, J. [Cornell University, Ithaca, NY 14853 (United States)

2014-12-11

We describe the design and performance of optical elements for an x-ray beam size monitor (xBSM), a device measuring e{sup +} and e{sup −} beam sizes in the CESR-TA storage ring. The device can measure vertical beam sizes of 10–100μm on a turn-by-turn, bunch-by-bunch basis at e{sup ±} beam energies of ∼2–5GeV. x-rays produced by a hard-bend magnet pass through a single- or multiple-slit (coded aperture) optical element onto a detector. The coded aperture slit pattern and thickness of masking material forming that pattern can both be tuned for optimal resolving power. We describe several such optical elements and show how well predictions of simple models track measured performances. - Highlights: • We characterize optical element performance of an e{sup ±} x-ray beam size monitor. • We standardize beam size resolving power measurements to reference conditions. • Standardized resolving power measurements compare favorably to model predictions. • Key model features include simulation of photon-counting statistics and image fitting. • Results validate a coded aperture design optimized for the x-ray spectrum encountered.

RADHEAT-V3, a code system for generating coupled neutron and gamma-ray group constants and analyzing radiation transport

International Nuclear Information System (INIS)

Koyama, Kinji; Taji, Yukichi; Miyasaka, Shun-ichi; Minami, Kazuyoshi.

1977-07-01

The modular code system RADHEAT is for producing coupled multigroup neutron and gamma-ray cross section sets, analyzing the neutron and gamma-ray transport, and calculating the energy deposition and atomic displacements due to these radiations in a nuclear reactor or shield. The basic neutron cross sections and secondary gamma-ray production data are taken from ENDF/B and POPOP4 libraries respectively. The system (1) generates multigroup neutron cross sections, energy deposition coefficients and atomic displacement factors due to neutron reactions, (2) generates multigroup gamma-ray cross sections and energy transfer coefficients, (3) generates secondary gamma-ray production cross sections, (4) combines these cross sections into the coupled set, (5) outputs and updates the multigroup cross section libraries in convenient formats for other transport codes, (6) analyzes the neutron and gamma-ray transport and calculates the energy deposition and the number density of atomic displacements in a medium, (7) collapses the cross sections to a broad-group structure, by option, using the weighting functions obtained by one-dimensional transport calculation, and (8) plots, by option, multigroup cross sections, and neutron and gamma-ray distributions. Definitions of the input data required in various options of the code system are also given. (auth.)

Design criteria for small coded aperture masks in gamma-ray astronomy

International Nuclear Information System (INIS)

Sembay, S.; Gehrels, N.

1990-01-01

Most theoretical work on coded aperture masks in X-ray and low-energy γ-ray astronomy has concentrated on masks with large numbers of elements. For γ-ray spectrometers in the MeV range, the detector plane usually has only a few discrete elements, so that masks with small numbers of elements are called for. For this case it is feasible to analyse by computer all the possible mask patterns of given dimension to find the ones that best satisfy the desired performance criteria. In this paper we develop a particular set of performance criteria for comparing the flux sensitivities, source positioning accuracies and transparencies of different mask patterns. We then present the results of such a computer analysis for masks up to dimension 5x5 unit cell and conclude that there is a great deal of flexibility in one's choice of mask pattern for each dimension. (orig.)

An X-ray imager based on silicon microstrip detector and coded mask

International Nuclear Information System (INIS)

Del Monte, E.; Costa, E.; Di Persio, G.; Donnarumma, I.; Evangelista, Y.; Feroci, M.; Frutti, M.; Lapshov, I.; Lazzarotto, F.; Mastropietro, M.; Morelli, E.; Pacciani, L.; Porrovecchio, G.; Rapisarda, M.; Rubini, A.; Soffitta, P.; Tavani, M.; Argan, A.

2007-01-01

SuperAGILE is the X-ray monitor of AGILE, a satellite mission for gamma-ray astronomy, and it is the first X-ray imaging instrument based on the technology of the silicon microstrip detectors combined with a coded aperture imaging technique. The SuperAGILE detection plane is composed of four 1-D silicon microstrip detector modules, mechanically coupled to tungsten coded mask units. The detector strips are separately and individually connected to the input analogue channels of the front-end electronics, composed of low-noise and low-power consumption VLSI ASIC chips. SuperAGILE can produce 1-D images with 6 arcmin angular resolution and ∼2-3 arcmin localisation capability, for intense sources, in a field of view composed of two orthogonal areas of 107 deg. x 68 deg. The time resolution is 2 μs, the overall dead time is ∼5 μs and the electronic noise is ∼7.5 keV full-width at half-maximum. The resulting instrument is very compact (40x40x14 cm 3 ), light (10 kg) and has low power consumption (12 W). AGILE is a mission of the Agenzia Spaziale Italiana and its launch is planned in 2007 in a low equatorial Earth orbit. In this contribution we present SuperAGILE and discuss its performance and scientific objectives

Control of the Low-energy X-rays by Using MCNP5 and Numerical Analysis for a New Concept Intra-oral X-ray Imaging System

Science.gov (United States)

Huh, Jangyong; Ji, Yunseo; Lee, Rena

2018-05-01

An X-ray control algorithm to modulate the X-ray intensity distribution over the FOV (field of view) has been developed by using numerical analysis and MCNP5, a particle transport simulation code on the basis of the Monte Carlo method. X-rays, which are widely used in medical diagnostic imaging, should be controlled in order to maximize the performance of the X-ray imaging system. However, transporting X-rays, like a liquid or a gas is conveyed through a physical form such as pipes, is not possible. In the present study, an X-ray control algorithm and technique to uniformize the Xray intensity projected on the image sensor were developed using a flattening filter and a collimator in order to alleviate the anisotropy of the distribution of X-rays due to intrinsic features of the X-ray generator. The proposed method, which is combined with MCNP5 modeling and numerical analysis, aimed to optimize a flattening filter and a collimator for a uniform distribution of X-rays. Their size and shape were estimated from the method. The simulation and the experimental results both showed that the method yielded an intensity distribution over an X-ray field of 6×4 cm2 at SID (source to image-receptor distance) of 5 cm with a uniformity of more than 90% when the flattening filter and the collimator were mounted on the system. The proposed algorithm and technique are not only confined to flattening filter development but can also be applied for other X-ray related research and development efforts.

RODMOD: a code for control rod positioning

International Nuclear Information System (INIS)

Vondy, D.R.; Fowler, T.B.

1978-11-01

The report documents a computer code which has been implemented to position control rods according to a prescribed schedule during the calculation of a reactor history. Control rods may be represented explicitly with or without internal black absorber conditions in selected energy groups, or fractional insertion may be done, or both, in a problem. There is provision for control rod follower, movement of materials through a series of zones in a closed loop, and shutdown rod insertion and subsequent removal to allow the reactor history calculation to be continued. This code is incorporated in the system containing the VENTURE diffusion theory neutronics and the BURNER exposure codes for routine use. The implemented automated procedures cause the prescribed control rod insertion schedule to be applied without the access of additional user input data during the calculation of a reactor operating history

Measurement control for plutonium isotopic measurements using gamma-ray spectrometry

International Nuclear Information System (INIS)

Fleissner, J.G.

1985-01-01

A measurement control (MC) program should be an integral part of every nondestructive assay measurement system used for the assay of special nuclear materials. This report describes an MC program for plutonium isotopic composition measurements using high-resolution gamma-ray spectroscopy. This MC program emphasizes the standardization of data collection procedures along with the implementation of internal and external measurement control checks to provide the requisite measurement quality assurance. This report also describes the implementation of the MC program in the isotopic analysis code GRPAUT. Recommendations are given concerning the importance and frequency of the various MC checks in order to ensure a successful implementation of the MC procedures for the user's application

An evaluation of the background introduced from the coded aperture mask in the low energy gamma-ray telescope ZEBRA

International Nuclear Information System (INIS)

Butler, R.C.; Caroli, E.; Di Cocco, G.; Maggioli, P.P.; Spizzichino, A.; Charalambous, P.M.; Dean, A.J.; Drane, M.; Gil, A.; Stephen, J.B.; Perotti, F.; Villa, G.; Badiali, M.; La Padula, C.; Polcaro, F.; Ubertini, P.

1984-01-01

The background which arises from the presence of a coded aperture mask is evaluated. The major contributions which have been considered here are the interactions with the mask of the isotropic gamma-ray background, a parallel gamma-ray beam, neutrons and the effect of the mask element profile. It is shown that none of these factors conbribute to a significant excess or modulation in the background counting rate over the detection plane. In this way the use of a passive rather than an active coded aperture mask is seen to be suitable for use in a low energy gamma-ray telescope. (orig.)

A point-kernel shielding code for calculations of neutron and secondary gamma-ray 1cm dose equivalents: PKN

International Nuclear Information System (INIS)

Kotegawa, Hiroshi; Tanaka, Shun-ichi

1991-09-01

A point-kernel integral technique code, PKN, and the related data library have been developed to calculate neutron and secondary gamma-ray dose equivalents in water, concrete and iron shields for neutron sources in 3-dimensional geometry. The comparison between calculational results of the present code and those of the 1-dimensional transport code ANISN = JR, and the 2-dimensional transport code DOT4.2 showed a sufficient accuracy, and the availability of the PKN code has been confirmed. (author)

Coded ultrasonic remote control without batteries

International Nuclear Information System (INIS)

Gerhardy, C; Burlage, K; Schomburg, W K

2009-01-01

A concept for battery-less remote controls has been developed based on mechanically actuated beams and micro whistles generating ultrasound signals. These signals need to be frequency or time coded to increase the number of signals which can be distinguished from each other and environmental ultrasound. Several designs for generating coded ultrasonic signals have been investigated

Micro controller application as x-ray machine's high voltage controller

International Nuclear Information System (INIS)

Wiranto Budi Santoso; Beny Syawaludin

2010-01-01

The micro controller application as x-ray machine's high voltage controller has been carried out. The purpose of this micro controller application is to give an accurate high voltage supply to the x-ray tube so that the x ray machine could produce the result as expected. The micro controller based X-ray machine's high voltage controller receives an input voltage from the keypad. This input value is displayed in the LCD (Liquid Crystal Display) screen. Then micro controller uses this input data to drive the stepper motor. The stepper motor adjusts the high voltage auto transformer's output according to the input value. The micro controller is programmed using BASCOM-B051 compiler. The test results show that the stepper motor could rotate according to an input value. (author)

Calculation of the X-Ray Spectrum of a Mammography System with Various Voltages and Different Anode-Filter Combinations Using MCNP Code

Directory of Open Access Journals (Sweden)

Lida Gholamkar

2016-09-01

Full Text Available Introduction One of the best methods in the diagnosis and control of breast cancer is mammography. The importance of mammography is directly related to its value in the detection of breast cancer in the early stages, which leads to a more effective treatment. The purpose of this article was to calculate the X-ray spectrum in a mammography system with Monte Carlo codes, including MCNPX and MCNP5. Materials and Methods The device, simulated using the MCNP code, was Planmed Nuance digital mammography device (Planmed Oy, Finland, equipped with an amorphous selenium detector. Different anode/filter materials, such as molybdenum-rhodium (Mo-Rh, molybdenum-molybdenum (Mo-Mo, tungsten-tin (W-Sn, tungsten-silver (W-Ag, tungsten-palladium (W-Pd, tungsten-aluminum (W-Al, tungsten-molybdenum (W-Mo, molybdenum-aluminum (Mo-Al, tungsten-rhodium (W-Rh, rhodium-aluminum (Rh-Al, and rhodium-rhodium (Rh-Rh, were simulated in this study. The voltage range of the X-ray tube was between 24 and 34 kV with a 2 kV interval. Results The charts of changing photon flux versus energy were plotted for different types of anode-filter combinations. The comparison with the findings reported by others indicated acceptable consistency. Also, the X-ray spectra, obtained from MCNP5 and MCNPX codes for W-Ag and W-Rh combinations, were compared. We compared the present results with the reported data of MCNP4C and IPEM report No. 78 for Mo-Mo, Mo-Rh, and W-Al combinations. Conclusion The MCNPX calculation outcomes showed acceptable results in a low-energy X-ray beam range (10-35 keV. The obtained simulated spectra for different anode/filter combinations were in good conformity with the finding of previous research.

Comparison of a semi-empirical method with some model codes for gamma-ray spectrum calculation

Energy Technology Data Exchange (ETDEWEB)

Sheng, Fan; Zhixiang, Zhao [Chinese Nuclear Data Center, Beijing, BJ (China)

1996-06-01

Gamma-ray spectra calculated by a semi-empirical method are compared with those calculated by the model codes such as GNASH, TNG, UNF and NDCP-1. The results of the calculations are discussed. (2 tabs., 3 figs.).

Implementation of Energy Code Controls Requirements in New Commercial Buildings

Energy Technology Data Exchange (ETDEWEB)

Rosenberg, Michael I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hart, Philip R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hatten, Mike [Solarc Energy Group, LLC, Seattle, WA (United States); Jones, Dennis [Group 14 Engineering, Inc., Denver, CO (United States); Cooper, Matthew [Group 14 Engineering, Inc., Denver, CO (United States)

2017-03-24

Most state energy codes in the United States are based on one of two national model codes; ANSI/ASHRAE/IES 90.1 (Standard 90.1) or the International Code Council (ICC) International Energy Conservation Code (IECC). Since 2004, covering the last four cycles of Standard 90.1 updates, about 30% of all new requirements have been related to building controls. These requirements can be difficult to implement and verification is beyond the expertise of most building code officials, yet the assumption in studies that measure the savings from energy codes is that they are implemented and working correctly. The objective of the current research is to evaluate the degree to which high impact controls requirements included in commercial energy codes are properly designed, commissioned and implemented in new buildings. This study also evaluates the degree to which these control requirements are realizing their savings potential. This was done using a three-step process. The first step involved interviewing commissioning agents to get a better understanding of their activities as they relate to energy code required controls measures. The second involved field audits of a sample of commercial buildings to determine whether the code required control measures are being designed, commissioned and correctly implemented and functioning in new buildings. The third step includes compilation and analysis of the information gather during the first two steps. Information gathered during these activities could be valuable to code developers, energy planners, designers, building owners, and building officials.

LabVIEW control software for scanning micro-beam X-ray fluorescence spectrometer.

Science.gov (United States)

Wrobel, Pawel; Czyzycki, Mateusz; Furman, Leszek; Kolasinski, Krzysztof; Lankosz, Marek; Mrenca, Alina; Samek, Lucyna; Wegrzynek, Dariusz

2012-05-15

Confocal micro-beam X-ray fluorescence microscope was constructed. The system was assembled from commercially available components - a low power X-ray tube source, polycapillary X-ray optics and silicon drift detector - controlled by an in-house developed LabVIEW software. A video camera coupled to optical microscope was utilized to display the area excited by X-ray beam. The camera image calibration and scan area definition software were also based entirely on LabVIEW code. Presently, the main area of application of the newly constructed spectrometer is 2-dimensional mapping of element distribution in environmental, biological and geological samples with micrometer spatial resolution. The hardware and the developed software can already handle volumetric 3-D confocal scans. In this work, a front panel graphical user interface as well as communication protocols between hardware components were described. Two applications of the spectrometer, to homogeneity testing of titanium layers and to imaging of various types of grains in air particulate matter collected on membrane filters, were presented. Copyright © 2012 Elsevier B.V. All rights reserved.

GAMUT: A computer code for γ-ray energy and intensity analysis

International Nuclear Information System (INIS)

Firestone, R.B.

1991-05-01

GAMUT is a computer code to analyze γ-ray energies and intensities. It does a linear least-squares fit of measured γ-ray energies from one or more experiments to the level scheme. GAMUT also performs a non-linear least-squares analysis of branching intensities. For both energy and intensity data, a statistical Chi-square analysis is performed with an iterative uncertainty adjustment. The uncertainties of outlying measured values and sets of measurements with x 2 /f>1 are increased, and the calculation is repeated until the uncertainties are consistent with the fitted values. GAMUT accepts input from standard or special-format ENSDF data sets. The special-format ENSDF data sets were designed to permit analysis of more than one set of measurements associated with a single ENSDF data set. GAMUT prepares a standard ENSDF format output data set containing the adjusted values. If more than one input ENSDF data set is provided, GAMUT creates an ADOPTED LEVELS, GAMMAS data set containing the adjusted level and γ-ray energies and branching intensities from each level normalized to 100 for the strongest γ-ray. GAMUT also provides a summary of the results and an extensive log of the iterative analysis. GAMUT is interactive prompting the user for input and output file names and for default calculation options. This version of GAMUT has adjustable dimensions so that any maximum number of data sets, levels, and γ-rays can be established at the time of implementation. 6 refs

Cosmic rays exposure during aircraft flight (3). Guideline and dose evaluation

International Nuclear Information System (INIS)

Yasuda, Hiroshi

2007-01-01

Radiation Council of MEXT drew up the Guideline of Cosmic Ray Exposure Control for Air Crew in 2006. The content of the Guideline and evaluation methods of dose are explained. The Guideline stated five items for Airline Company. It consists of 1) exposure dose control for air crew, 2) evaluation methods of cosmic rays exposure dose of air crew, 3) explanation and education of cosmic rays exposure for air crew, 4) reading, record and store of cosmic rays exposure dose of air crew, and 5) health control of air crew. The doses of four airlines were calculated by the Civil Aeromedical Research Institute (CARI) code and the European Program package for the Calculation of Aviation Route Doses (EPCARD) code. The difference of two codes was about 15 to 25%. Japanese Internet System for Calculation of Aviation Route Doses (JISCAED) has been developed by Japan. (S.Y.)

Analysis of visual coding variables on CRT generated displays

International Nuclear Information System (INIS)

Blackman, H.S.; Gilmore, W.E.

1985-01-01

Cathode ray tube generated safety parameter display systems in a nuclear power plant control room situation have been found to be improved in effectiveness when color coding is employed. Research has indicated strong support for graphic coding techniques particularly in redundant coding schemes. In addition, findings on pictographs, as applied in coding schemes, indicate the need for careful application and for further research in the development of a standardized set of symbols

CREME96: A revision of the Cosmic Ray Effects on Micro-Electronics code

International Nuclear Information System (INIS)

Tylka, A.J.; Adams, J.H. Jr.; Boberg, P.R.

1997-01-01

CREME96 is an update of the Cosmic Ray Effects on Micro-Electronics code, a widely-used suite of programs for creating numerical models of the ionizing-radiation environment in near-Earth orbits and for evaluating radiation effects in spacecraft. CREME96, which is now available over the World-Wide Web (WWW) at http://crsp3.nrl.navy.mil/creme96/, has many significant features, including (1) improved models of the galactic cosmic ray, anomalous cosmic ray, and solar energetic particle (flare) components of the near-Earth environment; (2) improved geomagnetic transmission calculations; (3) improved nuclear transport routines; (4) improved single-event upset (SEU) calculation techniques, for both proton-induced and direct-ionization-induced SEUs; and (5) an easy-to-use graphical interface, with extensive on-line tutorial information. In this paper the authors document some of these improvements

BLINDAGE: A neutron and gamma-ray transport code for shieldings with the removal-diffusion technique coupled with the point-kernel technique

International Nuclear Information System (INIS)

Fanaro, L.C.C.B.

1984-01-01

It was developed the BLINDAGE computer code for the radiation transport (neutrons and gammas) calculation. The code uses the removal - diffusion method for neutron transport and point-kernel technique with buil-up factors for gamma-rays. The results obtained through BLINDAGE code are compared with those obtained with the ANISN and SABINE computer codes. (Author) [pt

A computer code for calculation of radioactive nuclide generation and depletion, decay heat and γ ray spectrum. FPGS90

International Nuclear Information System (INIS)

Ihara, Hitoshi; Katakura, Jun-ichi; Nakagawa, Tsuneo

1995-11-01

In a nuclear reactor radioactive nuclides are generated and depleted with burning up of nuclear fuel. The radioactive nuclides, emitting γ ray and β ray, play role of radioactive source of decay heat in a reactor and radiation exposure. In safety evaluation of nuclear reactor and nuclear fuel cycle, it is needed to estimate the number of nuclides generated in nuclear fuel under various burn-up condition of many kinds of nuclear fuel used in a nuclear reactor. FPGS90 is a code calculating the number of nuclides, decay heat and spectrum of emitted γ ray from fission products produced in a nuclear fuel under the various kinds of burn-up condition. The nuclear data library used in FPGS90 code is the library 'JNDC Nuclear Data Library of Fission Products - second version -', which is compiled by working group of Japanese Nuclear Data Committee for evaluating decay heat in a reactor. The code has a function of processing a so-called evaluated nuclear data file such as ENDF/B, JENDL, ENSDF and so on. It also has a function of making figures of calculated results. Using FPGS90 code it is possible to do all works from making library, calculating nuclide generation and decay heat through making figures of the calculated results. (author)

A computer code for calculation of radioactive nuclide generation and depletion, decay heat and {gamma} ray spectrum. FPGS90

Energy Technology Data Exchange (ETDEWEB)

Ihara, Hitoshi; Katakura, Jun-ichi; Nakagawa, Tsuneo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1995-11-01

In a nuclear reactor radioactive nuclides are generated and depleted with burning up of nuclear fuel. The radioactive nuclides, emitting {gamma} ray and {beta} ray, play role of radioactive source of decay heat in a reactor and radiation exposure. In safety evaluation of nuclear reactor and nuclear fuel cycle, it is needed to estimate the number of nuclides generated in nuclear fuel under various burn-up condition of many kinds of nuclear fuel used in a nuclear reactor. FPGS90 is a code calculating the number of nuclides, decay heat and spectrum of emitted {gamma} ray from fission products produced in a nuclear fuel under the various kinds of burn-up condition. The nuclear data library used in FPGS90 code is the library `JNDC Nuclear Data Library of Fission Products - second version -`, which is compiled by working group of Japanese Nuclear Data Committee for evaluating decay heat in a reactor. The code has a function of processing a so-called evaluated nuclear data file such as ENDF/B, JENDL, ENSDF and so on. It also has a function of making figures of calculated results. Using FPGS90 code it is possible to do all works from making library, calculating nuclide generation and decay heat through making figures of the calculated results. (author).

3D-printed coded apertures for x-ray backscatter radiography

Science.gov (United States)

Muñoz, André A. M.; Vella, Anna; Healy, Matthew J. F.; Lane, David W.; Jupp, Ian; Lockley, David

2017-09-01

Many different mask patterns can be used for X-ray backscatter imaging using coded apertures, which can find application in the medical, industrial and security sectors. While some of these patterns may be considered to have a self-supporting structure, this is not the case for some of the most frequently used patterns such as uniformly redundant arrays or any pattern with a high open fraction. This makes mask construction difficult and usually requires a compromise in its design by drilling holes or adopting a no two holes touching version of the original pattern. In this study, this compromise was avoided by 3D printing a support structure that was then filled with a radiopaque material to create the completed mask. The coded masks were manufactured using two different methods, hot cast and cold cast. Hot casting involved casting a bismuth alloy at 80°C into the 3D printed acrylonitrile butadiene styrene mould which produced an absorber with density of 8.6 g cm-3. Cold casting was undertaken at room temperature, when a tungsten/epoxy composite was cast into a 3D printed polylactic acid mould. The cold cast procedure offered a greater density of around 9.6 to 10 g cm-3 and consequently greater X-ray attenuation. It was also found to be much easier to manufacture and more cost effective. A critical review of the manufacturing procedure is presented along with some typical images. In both cases the 3D printing process allowed square apertures to be created avoiding their approximation by circular holes when conventional drilling is used.

An intercomparison of Monte Carlo codes used for in-situ gamma-ray spectrometry

International Nuclear Information System (INIS)

Hurtado, S.; Villa, M.

2010-01-01

In-situ gamma-ray spectrometry is widely used for monitoring of natural as well as man-made radionuclides and corresponding gamma fields in the environment or working places. It finds effective application in the operational and accidental monitoring of nuclear facilities and their vicinity, waste depositories, radioactive contamination measurements and environmental mapping or geological prospecting. In order to determine accurate radionuclide concentrations in these research fields, Monte Carlo codes have recently been used to obtain the efficiency calibration of in-situ gamma-ray detectors. This work presents an inter-comparison between two Monte Carlo codes applied to in-situ gamma-ray spectrometry. On the commercial market, Canberra has its LABSOCS/ISOCS software which is relatively inexpensive. The ISOCS mathematical efficiency calibration software uses a combination of Monte Carlo calculations and discrete ordinate attenuation computations. Efficiencies can be generated in a few minutes in the field and can be modified easily if needed. However, it has been reported in the literature that ISOCS computation method is accurate on average only within 5%, and additionally in order to use LABSOCS/ISOCS it is necessary a previous characterization of the detector by Canberra, which is an expensive process. On the other hand, the multipurpose and open source GEANT4 takes significant computer time and presents a non-friendly but powerful toolkit, independent of the manufacturer of the detector. Different experimental measurements of calibrated sources were performed with a Canberra portable HPGe detector and compared to the results obtained using both Monte Carlo codes. Furthermore, a variety of efficiency calibrations for different radioactive source distributions were calculated and tested, like plane shapes or containers filled with different materials such as soil, water, etc. LabSOCS simulated efficiencies for medium and high energies were given within an

Approximated transport-of-intensity equation for coded-aperture x-ray phase-contrast imaging.

Science.gov (United States)

Das, Mini; Liang, Zhihua

2014-09-15

Transport-of-intensity equations (TIEs) allow better understanding of image formation and assist in simplifying the "phase problem" associated with phase-sensitive x-ray measurements. In this Letter, we present for the first time to our knowledge a simplified form of TIE that models x-ray differential phase-contrast (DPC) imaging with coded-aperture (CA) geometry. The validity of our approximation is demonstrated through comparison with an exact TIE in numerical simulations. The relative contributions of absorption, phase, and differential phase to the acquired phase-sensitive intensity images are made readily apparent with the approximate TIE, which may prove useful for solving the inverse phase-retrieval problem associated with these CA geometry based DPC.

A model of polarized-beam AGS in the ray-tracing code Zgoubi

Energy Technology Data Exchange (ETDEWEB)

Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ahrens, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brown, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dutheil, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Glenn, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roser, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Shoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2016-07-12

A model of the Alternating Gradient Synchrotron, based on the AGS snapramps, has been developed in the stepwise ray-tracing code Zgoubi. It has been used over the past 5 years in a number of accelerator studies aimed at enhancing RHIC proton beam polarization. It is also used to study and optimize proton and Helion beam polarization in view of future RHIC and eRHIC programs. The AGS model in Zgoubi is operational on-line via three different applications, ’ZgoubiFromSnaprampCmd’, ’AgsZgoubiModel’ and ’AgsModelViewer’, with the latter two essentially interfaces to the former which is the actual model ’engine’. All three commands are available from the controls system application launcher in the AGS ’StartUp’ menu, or from eponymous commands on shell terminals. Main aspects of the model and of its operation are presented in this technical note, brief excerpts from various studies performed so far are given for illustration, means and methods entering in ZgoubiFromSnaprampCmd are developed further in appendix.

Adaptive Wavelet Coding Applied in a Wireless Control System.

Science.gov (United States)

Gama, Felipe O S; Silveira, Luiz F Q; Salazar, Andrés O

2017-12-13

Wireless control systems can sense, control and act on the information exchanged between the wireless sensor nodes in a control loop. However, the exchanged information becomes susceptible to the degenerative effects produced by the multipath propagation. In order to minimize the destructive effects characteristic of wireless channels, several techniques have been investigated recently. Among them, wavelet coding is a good alternative for wireless communications for its robustness to the effects of multipath and its low computational complexity. This work proposes an adaptive wavelet coding whose parameters of code rate and signal constellation can vary according to the fading level and evaluates the use of this transmission system in a control loop implemented by wireless sensor nodes. The performance of the adaptive system was evaluated in terms of bit error rate (BER) versus E b / N 0 and spectral efficiency, considering a time-varying channel with flat Rayleigh fading, and in terms of processing overhead on a control system with wireless communication. The results obtained through computational simulations and experimental tests show performance gains obtained by insertion of the adaptive wavelet coding in a control loop with nodes interconnected by wireless link. These results enable the use of this technique in a wireless link control loop.

Adaptive Wavelet Coding Applied in a Wireless Control System

Directory of Open Access Journals (Sweden)

Felipe O. S. Gama

2017-12-01

Full Text Available Wireless control systems can sense, control and act on the information exchanged between the wireless sensor nodes in a control loop. However, the exchanged information becomes susceptible to the degenerative effects produced by the multipath propagation. In order to minimize the destructive effects characteristic of wireless channels, several techniques have been investigated recently. Among them, wavelet coding is a good alternative for wireless communications for its robustness to the effects of multipath and its low computational complexity. This work proposes an adaptive wavelet coding whose parameters of code rate and signal constellation can vary according to the fading level and evaluates the use of this transmission system in a control loop implemented by wireless sensor nodes. The performance of the adaptive system was evaluated in terms of bit error rate (BER versus E b / N 0 and spectral efficiency, considering a time-varying channel with flat Rayleigh fading, and in terms of processing overhead on a control system with wireless communication. The results obtained through computational simulations and experimental tests show performance gains obtained by insertion of the adaptive wavelet coding in a control loop with nodes interconnected by wireless link. These results enable the use of this technique in a wireless link control loop.

A super-high angular resolution principle for coded-mask X-ray imaging beyond the diffraction limit of a single pinhole

International Nuclear Information System (INIS)

Zhang Chen; Zhang Shuangnan

2009-01-01

High angular resolution X-ray imaging is always useful in astrophysics and solar physics. In principle, it can be performed by using coded-mask imaging with a very long mask-detector distance. Previously, the diffraction-interference effect was thought to degrade coded-mask imaging performance dramatically at the low energy end with its very long mask-detector distance. The diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method (DICC) is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle (SHARP) for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of a single pinhole is demonstrated with simulations. With the specification that the mask element size is 50 x 50 μm 2 and the mask-detector distance is 50 m, the achieved angular resolution is 0.32 arcsec above about 10 keV and 0.36 arcsec at 1.24 keV (λ = 1 nm), where diffraction cannot be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also briefly discussed. (invited reviews)

Controlling Energy Radiations of Electromagnetic Waves via Frequency Coding Metamaterials.

Science.gov (United States)

Wu, Haotian; Liu, Shuo; Wan, Xiang; Zhang, Lei; Wang, Dan; Li, Lianlin; Cui, Tie Jun

2017-09-01

Metamaterials are artificial structures composed of subwavelength unit cells to control electromagnetic (EM) waves. The spatial coding representation of metamaterial has the ability to describe the material in a digital way. The spatial coding metamaterials are typically constructed by unit cells that have similar shapes with fixed functionality. Here, the concept of frequency coding metamaterial is proposed, which achieves different controls of EM energy radiations with a fixed spatial coding pattern when the frequency changes. In this case, not only different phase responses of the unit cells are considered, but also different phase sensitivities are also required. Due to different frequency sensitivities of unit cells, two units with the same phase response at the initial frequency may have different phase responses at higher frequency. To describe the frequency coding property of unit cell, digitalized frequency sensitivity is proposed, in which the units are encoded with digits "0" and "1" to represent the low and high phase sensitivities, respectively. By this merit, two degrees of freedom, spatial coding and frequency coding, are obtained to control the EM energy radiations by a new class of frequency-spatial coding metamaterials. The above concepts and physical phenomena are confirmed by numerical simulations and experiments.

X-ray tube current control

International Nuclear Information System (INIS)

Dupuis, W.A.; Resnick, T.A.

1982-01-01

A closed loop feedback system for controlling the current output of an x-ray tube. The system has circuitry for improving the transient response and stability of the x-ray tube current over a substantial nonlinear portion of the tube current production characteristic. The system includes a reference generator for applying adjustable step function reference signals representing desired tube currents. The system also includes means for instantaneous sensing of actual tube current. An error detector compares the value of actual and reference tube current and produces an error signal as a function of their difference. The system feedback loop includes amplification circuitry for controlling x-ray tube filament dc voltage to regulate tube current as a function of the error signal value. The system also includes compensation circuitry, between the reference generator and the amplification circuitry, to vary the loop gain of the feedback control system as a function of the reference magnitude

Reactor Systems Technology Division code development and configuration/quality control procedures

International Nuclear Information System (INIS)

Johnson, E.C.

1985-06-01

Procedures are prescribed for executing a code development task and implementing the resulting coding in an official version of a computer code. The responsibilities of the project manager, development staff members, and the Code Configuration/Quality Control Group are defined. Examples of forms, logs, computer job control language, and suggested outlines for reports associated with software production and implementation are included in Appendix A. 1 raf., 2 figs

Control console for the X-ray room

International Nuclear Information System (INIS)

Garcia H, J.M.; Aguilar B, M.A.; Torres B, M.A.

1998-01-01

It is presented the design and construction of Control console for the X-ray room of Metrology Center for ionizing radiations at National Institute of Nuclear Research (ININ). This system controls the positioning of 6 different filters for an X-ray beam. Also it controls a shutter which blockades the beam during periods established by user, these periods can be fixed from hours until tenth of second. The shutter opening periods, as well as the X-ray beam filter are establish and monitoring from a Personal computer outside of room. (Author)

Electrical, instrumentation, and control codes and standards

International Nuclear Information System (INIS)

Kranning, A.N.

1978-01-01

During recent years numerous documents in the form of codes and standards have been developed and published to provide design, fabrication and construction rules and criteria applicable to instrumentation, control and power distribution facilities for nuclear power plants. The contents of this LTR were prepared by NUS Corporation under Subcontract K5108 and provide a consolidated index and listing of the documents selected for their application to procurement of materials and design of modifications and new construction at the LOFT facility. These codes and standards should be applied together with the National Electrical Code, the ID Engineering Standards and LOFT Specifications to all LOFT instrument and electrical design activities

Rey: a computer code for the determination of the radionuclides activities from the gamma-ray spectrum data

International Nuclear Information System (INIS)

Palomares, J.; Perez, A.; Travesi, A.

1978-01-01

The Fortran IV computer Code, REY (REsolution and Identification), has been developed for the automatic resolution of the gamma-ray spectra from high resolution Ge-Li detectors. The Code searches the full energy peaks in the spectra background as the base line under the peak and calculates the energy of the statistically significant peaks. Also the Code assigns each peak to the most probable isotope and makes a selection of all the possible radioisotopes of the spectra, according the relative intensities of all the peaks in the whole spectra. Finally, it obtains the activities, in microcuries of each isotope, according the geometry used in the measurement. Although the Code is a general purpose one, their actual library of nuclear data is adapted for the analysis of liquid effluents from nuclear power plants. A computer with a 16 core memory and a hard disk are sufficient for this code.(author)

Adaptation of radiation shielding code to space environment

International Nuclear Information System (INIS)

Okuno, Koichi; Hara, Akihisa

1992-01-01

Recently, the trend to the development of space has heightened. To the development of space, many problems are related, and as one of them, there is the protection from cosmic ray. The cosmic ray is the radiation having ultrahigh energy, and there was not the radiation shielding design code that copes with cosmic ray so far. Therefore, the high energy radiation shielding design code for accelerators was improved so as to cope with the peculiarity that cosmic ray possesses. Moreover, the calculation of the radiation dose equivalent rate in the moon base to which the countermeasures against cosmic ray were taken was simulated by using the improved code. As the important countermeasures for the safety protection from radiation, the covering with regolith is carried out, and the effect of regolith was confirmed by using the improved code. Galactic cosmic ray, solar flare particles, radiation belt, the adaptation of the radiation shielding code HERMES to space environment, the improvement of the three-dimensional hadron cascade code HETCKFA-2 and the electromagnetic cascade code EGS 4-KFA, and the cosmic ray simulation are reported. (K.I.)

Imaging x-ray sources at a finite distance in coded-mask instruments

International Nuclear Information System (INIS)

Donnarumma, Immacolata; Pacciani, Luigi; Lapshov, Igor; Evangelista, Yuri

2008-01-01

We present a method for the correction of beam divergence in finite distance sources imaging through coded-mask instruments. We discuss the defocusing artifacts induced by the finite distance showing two different approaches to remove such spurious effects. We applied our method to one-dimensional (1D) coded-mask systems, although it is also applicable in two-dimensional systems. We provide a detailed mathematical description of the adopted method and of the systematics introduced in the reconstructed image (e.g., the fraction of source flux collected in the reconstructed peak counts). The accuracy of this method was tested by simulating pointlike and extended sources at a finite distance with the instrumental setup of the SuperAGILE experiment, the 1D coded-mask x-ray imager onboard the AGILE (Astro-rivelatore Gamma a Immagini Leggero) mission. We obtained reconstructed images of good quality and high source location accuracy. Finally we show the results obtained by applying this method to real data collected during the calibration campaign of SuperAGILE. Our method was demonstrated to be a powerful tool to investigate the imaging response of the experiment, particularly the absorption due to the materials intercepting the line of sight of the instrument and the conversion between detector pixel and sky direction

Optimization of the Penelope code in F language for the simulation of the X-ray spectrum in radiodiagnosis

International Nuclear Information System (INIS)

Ballon P, C. I.; Quispe V, N. Y.; Vega R, J. L. J.

2017-10-01

The computational simulation to obtain the X-ray spectrum in the range of radio-diagnosis, allows a study and advance knowledge of the transport process of X-rays in the interaction with matter using the Monte Carlo method. With the obtaining of the X-ray spectra we can know the dose that the patient receives when he undergoes a radiographic study or CT, improving the quality of the obtained image. The objective of the present work was to implement and optimize the open source Penelope (Monte Carlo code for the simulation of the transport of electrons and photons in the matter) 2008 version programming extra code in functional language F, managing to double the processing speed, thus reducing the simulation time spent and errors when optimizing the software initially programmed in Fortran 77. The results were compared with those of Penelope, obtaining a good concordance. We also simulated the obtaining of a Pdd curve (depth dose profile) for a Theratron Equinox cobalt-60 teletherapy device, also validating the software implemented for high energies. (Author)

Applications of Monte Carlo codes to a study of gamma-ray buildup factors, skyshine and duct streaming

Energy Technology Data Exchange (ETDEWEB)

Hirayama, H. [High Energy Accelerator Research Organization (KEK), Ibaraki (Japan)

2001-07-01

Many shielding calculations for gamma-rays have continued to rely on point-kernel methods incorporating buildup factor data. Line beam or conical beam response functions, which are calculated using a Monte Carlo code, for skyshine problems are useful to estimate the skyshine dose from various facilities. A simple calculation method for duct streaming was proposed using the parameters calculated by the Monte Carlo code. It is therefore important to study, improve and produce basic parameters related to old, but still important, problems in the fields of radiation shielding using the Monte Carlo code. In this paper, these studies performed by several groups in Japan as applications of the Monte Carlo method are discussed. (orig.)

Comparison of pulsed fluoroscopy by direct control using a grid-controlled x-ray tube with pulsed fluoroscopy by primary control

International Nuclear Information System (INIS)

Chida, Koichi; Zuguchi, Masayuki; Ito, Daisuke; Sato, Kunihiko; Shimura, Hirotaka; Sasaki, Masatoshi

2001-01-01

Interventional radiology (IVR) procedures may involve high radiation doses that are potentially harmful to the patient. In IVR procedures, pulsed fluoroscopy can greatly decrease the radiation that the physician and patient receive. There are two types of pulsed fluoroscopy: direct control and primary (indirect) control. The purpose of this study was to compare pulsed fluoroscopy by direct control, using a grid-controlled x-ray tube, with pulsed fluoroscopy using primary control. For both types of pulsed fluoroscopy, we measured the waveforms (x-ray tube voltage, x-ray tube current, and x-ray output) and the relative radiation dose. In addition, we compared the decrease in radiation during pulsed fluoroscopy using a care filter. The studies were performed using a Siemens Bicor Plus x-ray System (direct control) and a Siemens Multistar Plus x-ray System (primary control). Using primary pulse control, a 50% decrease in the x-ray output waveform took approximately 0.5-1.0 msec, or longer with a lower x-ray tube current. Using direct pulse control, a 50% decrease in the x-ray output waveform took approximately 0.1 msec, and was independent of x-ray tube current. The rate of radiation reduction with primary pulse control using the care filter with a lower x-ray tube current had a slope exceeding 10%. Pulsed fluoroscopy by direct control using a grid-controlled x-ray tube permits an optimal radiation dose. To decrease the radiation in primary pulse control, a care filter must be used, particularly with a lower x-ray tube current. (author)

An analysis of options available for developing a common laser ray tracing package for Ares and Kull code frameworks

Energy Technology Data Exchange (ETDEWEB)

Weeratunga, S K

2008-11-06

Ares and Kull are mature code frameworks that support ALE hydrodynamics for a variety of HEDP applications at LLNL, using two widely different meshing approaches. While Ares is based on a 2-D/3-D block-structured mesh data base, Kull is designed to support unstructured, arbitrary polygonal/polyhedral meshes. In addition, both frameworks are capable of running applications on large, distributed-memory parallel machines. Currently, both these frameworks separately support assorted collections of physics packages related to HEDP, including one for the energy deposition by laser/ion-beam ray tracing. This study analyzes the options available for developing a common laser/ion-beam ray tracing package that can be easily shared between these two code frameworks and concludes with a set of recommendations for its development.

CoCo trial: Color-coded blood pressure Control, a randomized controlled study

Directory of Open Access Journals (Sweden)

Chmiel C

2014-10-01

Full Text Available Corinne Chmiel, Oliver Senn, Thomas Rosemann, Valerio Del Prete, Claudia Steurer-Stey Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland Background: Inadequate blood pressure (BP control is a frequent challenge in general practice. The objective of this study was to determine whether a color-coded BP booklet using a traffic light scheme (red, >180 mmHg systolic BP and/or >110 mmHg diastolic BP; yellow, >140–180 mmHg systolic BP or >90–110 mmHg diastolic BP; green, ≤140 mmHg systolic BP and ≤90 mmHg diastolic BP improves BP control and adherence with home BP measurement.Methods: In this two-group, randomized controlled trial, general practitioners recruited adult patients with a BP >140 mmHg systolic and/or >90 mmHg diastolic. Patients in the control group received a standard BP booklet and the intervention group used a color-coded booklet for daily home BP measurement. The main outcomes were changes in BP, BP control (treatment goal <140/90 mmHg, and adherence with home BP measurement after 6 months.Results: One hundred and twenty-one of 137 included patients qualified for analysis. After 6 months, a significant decrease in systolic and diastolic BP was achieved in both groups, with no significant difference between the groups (16.1/7.9 mmHg in the intervention group versus 13.1/8.6 mmHg in the control group, P=0.3/0.7. BP control (treatment target <140/90 mmHg was achieved significantly more often in the intervention group (43% versus 25%; P=0.037; number needed to treat of 5. Adherence with home BP measurement overall was high, with a trend in favor of the intervention group (98.6% versus 96.2%; P=0.1Conclusion: Color-coded BP self-monitoring significantly improved BP control (number needed to treat of 5, meaning that every fifth patient utilizing color-coded self-monitoring achieved better BP control after 6 months, but no significant between-group difference was

Method for measuring the focal spot size of an x-ray tube using a coded aperture mask and a digital detector.

Science.gov (United States)

Russo, Paolo; Mettivier, Giovanni

2011-04-01

The goal of this study is to evaluate a new method based on a coded aperture mask combined with a digital x-ray imaging detector for measurements of the focal spot sizes of diagnostic x-ray tubes. Common techniques for focal spot size measurements employ a pinhole camera, a slit camera, or a star resolution pattern. The coded aperture mask is a radiation collimator consisting of a large number of apertures disposed on a predetermined grid in an array, through which the radiation source is imaged onto a digital x-ray detector. The method of the coded mask camera allows one to obtain a one-shot accurate and direct measurement of the two dimensions of the focal spot (like that for a pinhole camera) but at a low tube loading (like that for a slit camera). A large number of small apertures in the coded mask operate as a "multipinhole" with greater efficiency than a single pinhole, but keeping the resolution of a single pinhole. X-ray images result from the multiplexed output on the detector image plane of such a multiple aperture array, and the image of the source is digitally reconstructed with a deconvolution algorithm. Images of the focal spot of a laboratory x-ray tube (W anode: 35-80 kVp; focal spot size of 0.04 mm) were acquired at different geometrical magnifications with two different types of digital detector (a photon counting hybrid silicon pixel detector with 0.055 mm pitch and a flat panel CMOS digital detector with 0.05 mm pitch) using a high resolution coded mask (type no-two-holes-touching modified uniformly redundant array) with 480 0.07 mm apertures, designed for imaging at energies below 35 keV. Measurements with a slit camera were performed for comparison. A test with a pinhole camera and with the coded mask on a computed radiography mammography unit with 0.3 mm focal spot was also carried out. The full width at half maximum focal spot sizes were obtained from the line profiles of the decoded images, showing a focal spot of 0.120 mm x 0.105 mm at 35

Procedure and code for calculating black control rods taking into account epithermal absorption, code CAS-1

International Nuclear Information System (INIS)

Martinc, R.; Trivunac, N.; Zivkovic, Z.

1964-12-01

This report describes the computer code CAS-1, calculation method and procedure applied for calculating the black control rods taking into account the epithermal neutron absorption. Results obtained for supercell method applied for regular lattice reflected in the multiplication medium is part of this report in addition to the computer code manual

Principles and applications of gamma-ray imaging for arms control

Science.gov (United States)

Ziock, K. P.

2018-01-01

The ability of gamma-rays to penetrate matter makes them an excellent signature for the detection of nuclear materials-except that this very ability makes their detection difficult. This is particularly true if one wishes to make images, since general-purpose focusing optics do not exist. Various indirect imaging techniques have been successfully applied to obtain gamma-ray images, including Compton and coded-aperture imaging. This paper reviews the different approaches, and discusses their advantages and disadvantages as illustrated with results obtained from different instruments designed for use in nuclear security applications.

Complexity control algorithm based on adaptive mode selection for interframe coding in high efficiency video coding

Science.gov (United States)

Chen, Gang; Yang, Bing; Zhang, Xiaoyun; Gao, Zhiyong

2017-07-01

The latest high efficiency video coding (HEVC) standard significantly increases the encoding complexity for improving its coding efficiency. Due to the limited computational capability of handheld devices, complexity constrained video coding has drawn great attention in recent years. A complexity control algorithm based on adaptive mode selection is proposed for interframe coding in HEVC. Considering the direct proportionality between encoding time and computational complexity, the computational complexity is measured in terms of encoding time. First, complexity is mapped to a target in terms of prediction modes. Then, an adaptive mode selection algorithm is proposed for the mode decision process. Specifically, the optimal mode combination scheme that is chosen through offline statistics is developed at low complexity. If the complexity budget has not been used up, an adaptive mode sorting method is employed to further improve coding efficiency. The experimental results show that the proposed algorithm achieves a very large complexity control range (as low as 10%) for the HEVC encoder while maintaining good rate-distortion performance. For the lowdelayP condition, compared with the direct resource allocation method and the state-of-the-art method, an average gain of 0.63 and 0.17 dB in BDPSNR is observed for 18 sequences when the target complexity is around 40%.

Electronic quality control on dental x-rays equipment

International Nuclear Information System (INIS)

Pomares C, Martin

1996-09-01

A brief description of dental x-ray equipment is done. The non-invasive quality control is treated as than the responsibilities from the dentists to the patient and the equipment. A propose for quality control for dental x-ray equipment, film and developer is include

Code of practice for ionizing radiation

International Nuclear Information System (INIS)

Khoo Boo Huat

1995-01-01

Prior to 1984, the use of ionizing radiation in Malaysia was governed by the Radioactive Substances Act of 1968. After 1984, its use came under the control of Act 304, called the Atomic Energy Licensing Act 1984. Under powers vested by the Act, the Radiation Protection (Basic Safety Standards) Regulations 1988 were formulated to regulate its use. These Acts do not provide information on proper working procedures. With the publication of the codes of Practice by The Standards and Industrial Research Institute of Malaysia (SIRIM), the users are now able to follow proper guidelines and use ionizing radiation safely and beneficially. This paper discusses the relevant sections in the following codes: 1. Code of Practice for Radiation Protection (Medical X-ray Diagnosis) MS 838:1983. 2. Code of Practice for Safety in Laboratories Part 4: Ionizing radiation MS 1042: Part 4: 1992. (author)

The complete mitochondrial genome of the Giant Manta ray, Manta birostris.

Science.gov (United States)

Hinojosa-Alvarez, Silvia; Díaz-Jaimes, Pindaro; Marcet-Houben, Marina; Gabaldón, Toni

2015-01-01

The complete mitochondrial genome of the giant manta ray (Manta birostris), consists of 18,075 bp with rich A + T and low G content. Gene organization and length is similar to other species of ray. It comprises of 13 protein-coding genes, 2 rRNAs genes, 23 tRNAs genes and 1 non-coding sequence, and the control region. We identified an AT tandem repeat region, similar to that reported in Mobula japanica.

Decision n. 2010-DC-0175 made on the 4. of February 2010 by the Nuclear Safety Authority and defining technical modalities and periodicities of controls as prescribed in the R. 4452-12 and R. 4452-13 articles of the Labour Code as well as in the R. 1333-7 et R. 1333-95 articles of the Public Health Code

International Nuclear Information System (INIS)

2010-01-01

This document defines the modalities of technical controls of sources and equipment emitting ionizing radiation, the modalities of technical controls of the surroundings, the modalities of the control of the efficiency of radioprotection organization and technical equipment (management of sealed and non-sealed radioactive sources, elimination of effluents and wastes associated with these sources), and the modalities of control of measurement instruments and of protection devices, altogether in application of the Labour code and of the Public Health code. Requirements defined by these both codes are recalled in appendix. They may depend on the radioactive source type or on the equipment (electric equipment generating X rays, particle accelerator, sealed sources or equipment containing such sources, not-sealed sources)

Computer codes for evaluation of control room habitability (HABIT)

International Nuclear Information System (INIS)

Stage, S.A.

1996-06-01

This report describes the Computer Codes for Evaluation of Control Room Habitability (HABIT). HABIT is a package of computer codes designed to be used for the evaluation of control room habitability in the event of an accidental release of toxic chemicals or radioactive materials. Given information about the design of a nuclear power plant, a scenario for the release of toxic chemicals or radionuclides, and information about the air flows and protection systems of the control room, HABIT can be used to estimate the chemical exposure or radiological dose to control room personnel. HABIT is an integrated package of several programs that previously needed to be run separately and required considerable user intervention. This report discusses the theoretical basis and physical assumptions made by each of the modules in HABIT and gives detailed information about the data entry windows. Sample runs are given for each of the modules. A brief section of programming notes is included. A set of computer disks will accompany this report if the report is ordered from the Energy Science and Technology Software Center. The disks contain the files needed to run HABIT on a personal computer running DOS. Source codes for the various HABIT routines are on the disks. Also included are input and output files for three demonstration runs

Application of X-ray imagery with coded aperture to laser-produced plasmas

International Nuclear Information System (INIS)

Fleurot, N.; Gex, J.P.; Sauneuf, R.; Beaucoudray, N. de.

1981-05-01

The analysis of the phenomena occurring inside microplasmas generated by laser techniques is often performed with images obtained by the X-rays or alpha particles emitted. Pinhole chambers are extensively used for this type of diagnostic. The number of photons or particles collected, however, decreases with increasing resolution as does the signal-to-noise (S/B) ratio. The coding schema shows that the coder and detector are both flat and parallel to one another. Each object point projects the shadow of the coder onto the detector. The coder shadow is a homothetic figure of the coder. The dimensions and the position of this shadow depend on the position of the point in space, which gives three dimensional information [fr

Control rod computer code IAMCOS: general theory and numerical methods

International Nuclear Information System (INIS)

West, G.

1982-11-01

IAMCOS is a computer code for the description of mechanical and thermal behavior of cylindrical control rods for fast breeders. This code version was applied, tested and modified from 1979 to 1981. In this report are described the basic model (02 version), theoretical definitions and computation methods [fr

Quality assurance through constancy control for X-ray film processors

International Nuclear Information System (INIS)

Weberling, R.

1982-01-01

A control method to check the reproduction of X-ray film processors and necessary instruments is presented. The application of a light sensitometer allows the production of test films daily, independent of X-ray exposures, X-ray film cassettes and X-ray intensifying screens. The optical densities on the test films will be read by means of a densitometer and the results are plotted on a special control chart. A limitation through optical densities of +-0,15 for Speed Index and +-0,20 for Contrast Index determines the tolerance variation for X-ray film processors. Targets of this control method are uniform image quality, dose reduction and saving of cost. (orig.) [de

Code of practice for the safe use of ionizing radiation in secondary schools (1986)

International Nuclear Information System (INIS)

1987-01-01

The code of practice is intended for schools and indicates the basic philosophy behind the current approach to the control of hazards associated with the use of ionizing radiation. The purpose of this code is to provide guidance on safe and proper practices in the use of radiation. It covers modes of radiation exposure, shielding, dose limits, responsibility, general rules, x-ray generators, general control of radioactive sources, sealed sources and unsealed sources

CRA Control Logic Realization for MARS 1-D/MASTER coupled Code System

International Nuclear Information System (INIS)

Han, Soonkyoo; Jeong, Sungsu; Lee, Suyong

2013-01-01

Both Multi-dimensional Analysis Reactor Safety (MARS) code and Multi-purpose Analyzer for Static and Transient Effects of Reactors (MASTER) code, developed by Korea Atomic Energy Research Institute (KAERI), can be coupled for various simulations of nuclear reactor system. In the MARS 1-D/MASTER coupled code system, MARS is used for the thermal hydraulic calculations and MASTER is used for reactor core calculations. In case of using this coupled code system, the movements of control rod assembly (CRA) are controlled by MASTER. MASTER, however, has a CRA control function which is inputted by user as a form of time dependent table. When simulations related to sequential CRA insertion or withdrawal which are not ejection or drop are performed, this CRA control function is not sufficient to demonstrate the process of CRA movements. Therefore an alternative way is proposed for realization of CRA control logic in MASTER. In this study, the manually realized CRA control logic was applied by inputting the time dependent CRA positions into MASTER. And the points of CRA movements were decided by iterations. At the end of CRA movement, the reactor power difference and the average coolant temperature difference were not out of the range of their dead bands. Therefore it means that this manually realized CRA control logic works appropriately in the dead bands of the logic. Therefore the proper CRA movement points could be decided by using this manually realized CRA control logic. Based on these results, it is verified that the proper CRA movement points can be chosen by using the proposed CRA control logic in this article. In conclusion, it is expected that this proposed CRA control logic in MASTER can be used to properly demonstrate the process related to CRA sequential movements in the MARS 1-D/MASTER coupled code system

Radiation transport phenomena and modeling - part A: Codes

International Nuclear Information System (INIS)

Lorence, L.J.

1997-01-01

The need to understand how particle radiation (high-energy photons and electrons) from a variety of sources affects materials and electronics has motivated the development of sophisticated computer codes that describe how radiation with energies from 1.0 keV to 100.0 GeV propagates through matter. Predicting radiation transport is the necessary first step in predicting radiation effects. The radiation transport codes that are described here are general-purpose codes capable of analyzing a variety of radiation environments including those produced by nuclear weapons (x-rays, gamma rays, and neutrons), by sources in space (electrons and ions) and by accelerators (x-rays, gamma rays, and electrons). Applications of these codes include the study of radiation effects on electronics, nuclear medicine (imaging and cancer treatment), and industrial processes (food disinfestation, waste sterilization, manufacturing.) The primary focus will be on coupled electron-photon transport codes, with some brief discussion of proton transport. These codes model a radiation cascade in which electrons produce photons and vice versa. This coupling between particles of different types is important for radiation effects. For instance, in an x-ray environment, electrons are produced that drive the response in electronics. In an electron environment, dose due to bremsstrahlung photons can be significant once the source electrons have been stopped

Gamma ray shielding study of barium-bismuth-borosilicate glasses as transparent shielding materials using MCNP-4C code, XCOM program, and available experimental data

Energy Technology Data Exchange (ETDEWEB)

Bagheri, Reza; Yousefinia, Hassan [Nuclear Fuel Cycle Research School (NFCRS), Nuclear Science and Technology Research Institute (NSTRI), Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Moghaddam, Alireza Khorrami [Radiology Department, Paramedical Faculty, Mazandaran University of Medical Sciences, Sari (Iran, Islamic Republic of)

2017-02-15

In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and 10th value layer values of barium-bismuth-borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium-bismuth-borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

A computer code to simulate X-ray imaging techniques

International Nuclear Information System (INIS)

Duvauchelle, Philippe; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

2000-01-01

A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests

A computer code to simulate X-ray imaging techniques

Energy Technology Data Exchange (ETDEWEB)

Duvauchelle, Philippe E-mail: philippe.duvauchelle@insa-lyon.fr; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

2000-09-01

A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests.

C code generation applied to nonlinear model predictive control for an artificial pancreas

DEFF Research Database (Denmark)

Boiroux, Dimitri; Jørgensen, John Bagterp

2017-01-01

This paper presents a method to generate C code from MATLAB code applied to a nonlinear model predictive control (NMPC) algorithm. The C code generation uses the MATLAB Coder Toolbox. It can drastically reduce the time required for development compared to a manual porting of code from MATLAB to C...

UNSPEC: revisited (semaphore code)

International Nuclear Information System (INIS)

Neifert, R.D.

1981-01-01

The UNSPEC code is used to solve the problem of unfolding an observed x-ray spectrum given the response matrix of the measuring system and the measured signal values. UNSPEC uses an iterative technique to solve the unfold problem. Due to experimental errors in the measured signal values and/or computer round-off errors, discontinuities and oscillatory behavior may occur in the iterated spectrum. These can be suppressed by smoothing the results after each iteration. Input/output options and control cards are explained; sample input and output are provided

The performance test of anti-scattering x-ray grid with inclined shielding material by MCNP code simulation

Energy Technology Data Exchange (ETDEWEB)

Bae, Jun Woo; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2016-06-15

The scattered photons cause reduction of the contrast of radiographic image and it results in the degradation of the quality of the image. In order to acquire better quality image, an anti-scattering x-ray gird should be equipped in radiography system. The X-ray anti-scattering grid of the inclined type based on the hybrid concept for that of parallel and focused type was tested by MCNP code. The MCNPX 2.7.0 was used for the simulation based test. The geometry for the test was based on the IEC 60627 which was an international standard for diagnostic X-ray imaging equipment-Characteristics of general purpose and mammographic anti-scatter grids. The performance of grids with four inclined shielding material types was compared with that of the parallel type. The grid with completely tapered type the best performance where there were little performance difference according to the degree of inclination.

Gamma Ray Shielding Study of Barium–Bismuth–Borosilicate Glasses as Transparent Shielding Materials using MCNP-4C Code, XCOM Program, and Available Experimental Data

Directory of Open Access Journals (Sweden)

Reza Bagheri

2017-02-01

Full Text Available In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and 10th value layer values of barium–bismuth–borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium–bismuth–borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

Semi-automated x-ray gauging process control system

International Nuclear Information System (INIS)

Draut, C.F.; Homan, D.A.

1976-01-01

An x-ray gauging method was developed and a production gauging system was subsequently fabricated to control the quality of precision manufactured components. The gauging system measures via x-ray absorption the density of pressed finely divided solids held in a dissimilar container. The two dissimilar materials condition necessitated a ''two scan'' technique: first, the x-ray attenuation (absorption) of the empty container prior to loading and then, the attenuation of the loaded container are measured; that is, four variables. The system provided greatly improved product control via timely data feedback and increased product quality assurance via 100 percent inspection of product. In addition, it reduced labor costs, product cost, and possibilities for human errors

Computer-controlled gamma-ray scanner for irradiated reactor fuel

International Nuclear Information System (INIS)

Mandler, J.W.; Coates, R.A.; Killian, E.W.

1979-01-01

Gamma-ray scanning of irradiated fuel is an important nondestructive technique used in the thermal fuels behavior program currently under way at the Idaho National Engineering Laboratory. This paper is concerned with the computer-controlled isotopic gamma-ray-scanning system developed for postirradiation examination of fuel and includes a brief discussion of some scan results obtained from fuel rods irradiated in the Power-Burst Facility to illustrate gamma-ray spectrometry for this application. Both burnup profiles and information concerning fission-product migration in irradiated fuel are routinely obtained with the computer-controlled system

JAX: a micro-computer based X-ray diffractometer controller

International Nuclear Information System (INIS)

Naval, P.C. Jr.

1987-05-01

This paper describes a micro-computer based X-ray diffractometer controller and explores its possibilities in simplifying acquisition and analysis of X-ray powder diffraction data. The interrupt-driven controller can operate in both present time and present count data acquisition modes and allows a data analysis program to execute concurrently with data collection. (Auth.). 16 figs.; 2 tabs

Microsecond-scale X-ray imaging with Controlled-Drift Detectors

International Nuclear Information System (INIS)

Castoldi, A.; Galimberti, A.; Guazzoni, C.; Rehak, P.; Strueder, L.

2006-01-01

The Controlled-Drift Detector is a fully-depleted silicon detector that allows 2-D position sensing and energy spectroscopy of X-rays in the range 0.5-20keV with excellent time resolution (few tens of μs) and limited readout channels. In this paper we review the Controlled-Drift Detector operating principle and we present the X-ray imaging and spectroscopic capabilities of Controlled Drift Detectors in microsecond-scale experiments and the more relevant applications fields

Power Control and Coding Formulation for State Estimation with Wireless Sensors

DEFF Research Database (Denmark)

Quevedo, Daniel; Østergaard, Jan; Ahlen, Anders

2014-01-01

efficient communication. In this paper, we examine the role of power control and coding for Kalman filtering over wireless correlated channels. Two estimation architectures are considered; initially, the sensors send their measurements directly to a single gateway (GW). Next, wireless relay nodes provide...... additional links. The GW decides on the coding scheme and the transmitter power levels of the wireless nodes. The decision process is carried out online and adapts to varying channel conditions to improve the tradeoff between state estimation accuracy and energy expenditure. In combination with predictive......Technological advances made wireless sensors cheap and reliable enough to be brought into industrial use. A major challenge arises from the fact that wireless channels introduce random packet dropouts. Power control and coding are key enabling technologies in wireless communications to ensure...

Development of a computer model using the EGS4 simulation code to calculate scattered X-rays through some materials

International Nuclear Information System (INIS)

Al-Ghorabie, F.H.H.

2003-01-01

In this paper a computer model based on the use of the well-known Monte Carlo simulation code EGS4 was developed to simulate the scattering of polyenergetic X-ray beams through some materials. These materials are: lucite, polyethylene, polypropylene and aluminium. In particular, the ratio of the scattered to total X-ray fluence (scatter fraction) has been calculated for X-ray beams in the energy region 30-120 keV. In addition scatter fractions have been determined experimentally using a polyenergetic superficial X-ray unit. Comparison of the measured and the calculated results has been performed. The Monte Carlo calculations have also been carried out for water, bakelite and bone to examine the dependence of scatter fraction on the density of the scatterer. Good agreement (estimated statistical error < 5%) was obtained between the measured and the calculated values of the scatter fractions for materials with Z < 20 that were studied in this paper. Copyright (2003) Australasian College of Physical Scientists and Engineers in Medicine

Control system of digital x-ray systems by quality parameters

International Nuclear Information System (INIS)

Balashov, S.V.; Kovalenko, Yu.N.

2013-01-01

The paper proposed a control system of X-ray digital equipment on quality indicators. Two basic parameters were determined: image quality and patients' radiation load. A method for monitoring these indicators is proposed. The criterion of equipment suitability is to obtain control digital X-ray images of diagnostically acceptable quality at a fixed low entrance dose in the plane of the digital detector. It is shown that the control system of X-ray digital equipment based on indicators of quality is the most appropriate in situations of deficit of financial resources, since minimizing the costs for the purchase and running of control systems, does not require highly skilled technical personnel, and reduces the duration of the equipment inspection. (authors)

Method of laser beam coding for control systems

Science.gov (United States)

Pałys, Tomasz; Arciuch, Artur; Walczak, Andrzej; Murawski, Krzysztof

2017-08-01

The article presents the method of encoding a laser beam for control systems. The experiments were performed using a red laser emitting source with a wavelength of λ = 650 nm and a power of P ≍ 3 mW. The aim of the study was to develop methods of modulation and demodulation of the laser beam. Results of research, in which we determined the effect of selected camera parameters, such as image resolution, number of frames per second on the result of demodulation of optical signal, is also shown in the paper. The experiments showed that the adopted coding method provides sufficient information encoded in a single laser beam (36 codes with the effectiveness of decoding at 99.9%).

X-Ray analysis and methods for nondestructive control (On the 100-anniversary of X-ray foundation)

International Nuclear Information System (INIS)

Sosnin, F.R.

1995-01-01

Brief consideration is given to the history of X-ray discovery, formation of domestic X-ray industry. Principles of operation and potentialities of X-ray diffraction analysis, gammagraphy, radioscopy, radiometric analysis are described briefly. Domestic and foreign scientists, institutes and companies who contributed much to development of methods for nondestructive control are listed

Contribution to gamma ray transport calculation in heterogeneous media

International Nuclear Information System (INIS)

Bourdet, L.

1985-04-01

This thesis presents the development of gamma transport calculation codes in three dimension heterogeneous geometries. These codes allow us to define the protection against gamma-rays or verify their efficiency. The laws that govern the interactions of gamma-rays with matters are briefly revised. A library with the all necessary constants for these codes is created. TRIPOLI-2, a code that treats in exact way the neutron transport in matters using Monte-Carlo method, has been adapted to deal with the transport of gamma-rays in matters as well. TRINISHI, a code which considers only one collision, has been realized to treat heterogeneous geometries containing voids. Elaborating a formula that calculates the albedo for gamma-ray reflection (the code ALBANE) allows us to solve the problem of gamma-ray reflection on plane surfaces. NARCISSE-2 deals with gamma-rays that suffer only one reflection on the inner walls of any closed volume (rooms, halls...) [fr

Computer code ANISN multiplying media and shielding calculation II. Code description (input/output)

International Nuclear Information System (INIS)

Maiorino, J.R.

1990-01-01

The user manual of the ANISN computer code describing input and output subroutines is presented. ANISN code was developed to solve one-dimensional transport equation for neutron or gamma rays in slab, sphere or cylinder geometry with general anisotropic scattering. The solution technique is the discrete ordinate method. (M.C.K.)

Plaspp: A New X-Ray Postprocessing Capability for ASCI Codes

International Nuclear Information System (INIS)

Pollak, Gregory

2003-01-01

This report announces the availability of the beta version of a (partly) new code, Plaspp (Plasma Postprocessor). This code postprocesses (graphics) dumps from at least two ASCI code suites: Crestone Project and Shavano Project. The basic structure of the code follows that of TDG, the equivalent postprocessor code for LASNEX. In addition to some new commands, the basic differences between TDG and Plaspp are the following: Plaspp uses a graphics dump instead of the unique TDG dump, it handles the unstructured meshes that the ASCI codes produce, and it can use its own multigroup opacity data. Because of the dump format, this code should be useable by any code that produces Cartesian, cylindrical, or spherical graphics formats. This report details the new commands; the required information to be placed on the dumps; some new commands and edits that are applicable to TDG as well, but have not been documented elsewhere; and general information about execution on the open and secure networks.

Quality control of diagnostic x-ray units

International Nuclear Information System (INIS)

Marinkovic, O.; Milacic, S.; Jovicic, D.; Tanaskovic, I.

2001-01-01

The quality control program for diagnostic x-ray units has started at the Institute of Occupational and Radiological Health during 1990. It includes, among other measurements, reproducibility of dose, high voltage and exposure time. Dose reproducibility was less than 5% for 70% of tested x-ray units. The exposure time and high voltage reproducibility were less than 5% in 60% cases. The cassettes with amplifying foils made from components of rare earth are used in 10% of all x-ray departments. It is very important to work as much as it is possible to modernize general infrastructure as the radiological protection of patients would be better. (author)

Measuring and test equipment control through bar-code technology

International Nuclear Information System (INIS)

Crockett, J.D.; Carr, C.C.

1993-01-01

Over the past several years, the use, tracking, and documentation of measuring and test equipment (M ampersand TE) has become a major issue. New regulations are forcing companies to develop new policies for providing use history, traceability, and accountability of M ampersand TE. This paper discusses how the Fast Flux Test Facility (FFTF), operated by Westinghouse Hanford Company and located at the Hanford site in Rich- land, Washington, overcame these obstacles by using a computerized system exercising bar-code technology. A data base was developed to identify M ampersand TE containing 33 separate fields, such as manufacturer, model, range, bar-code number, and other pertinent information. A bar-code label was attached to each piece of M ampersand TE. A second data base was created to identify the employee using the M ampersand TE. The fields contained pertinent user information such as name, location, and payroll number. Each employee's payroll number was bar coded and attached to the back of their identification badge. A computer program was developed to automate certain tasks previously performed and tracked by hand. Bar-code technology was combined with this computer program to control the input and distribution of information, eliminate common mistakes, electronically store information, and reduce the time required to check out the M ampersand TE for use

Developments in the ray-tracing code Zgoubi for 6-D multiturn tracking in FFAG rings

International Nuclear Information System (INIS)

Lemuet, F.; Meot, F.

2005-01-01

A geometrical method for 3-D modeling of the magnetic field in scaling and non-scaling FFAG magnets has been installed in the ray-tracing code Zgoubi. The method in particular allows a good simulation of transverse non-linearities, of field fall-offs and possible merging fields in configurations of neighboring magnets, while using realistic models of magnetic fields. That yields an efficient tool for FFAG lattice design and optimizations, and for 6-D tracking studies. It is applied for illustration to the simulation of an acceleration cycle in a 150 MeV radial sector proton FFAG

A microcontroller application as X-ray machine's high voltage controller

International Nuclear Information System (INIS)

Wiranto Budi Santoso; Beny Syawaludin

2010-01-01

A micro controller application as x-ray machine's high voltage controller has been carried out. The purpose of this micro controller application is to give an accurate high voltage supply to the x-ray tube so that the x-ray machine could produce the result as expected. The micro controller based X-ray machine's high voltage controller receives an input voltage from the keypad. This input value is displayed in the LCD (Liquid Crystal Display) screen. Then micro controller uses this input data to drive a stepper motor. The stepper motor adjusts the high voltage auto transformer's output according to the input value. The micro controller is programmed using BASCOM-8051 compiler. The test results show that the stepper motor could rotate according to an input value (author)

Mobile, hybrid Compton/coded aperture imaging for detection, identification and localization of gamma-ray sources at stand-off distances

Science.gov (United States)

Tornga, Shawn R.

The Stand-off Radiation Detection System (SORDS) program is an Advanced Technology Demonstration (ATD) project through the Department of Homeland Security's Domestic Nuclear Detection Office (DNDO) with the goal of detection, identification and localization of weak radiological sources in the presence of large dynamic backgrounds. The Raytheon-SORDS Tri-Modal Imager (TMI) is a mobile truck-based, hybrid gamma-ray imaging system able to quickly detect, identify and localize, radiation sources at standoff distances through improved sensitivity while minimizing the false alarm rate. Reconstruction of gamma-ray sources is performed using a combination of two imaging modalities; coded aperture and Compton scatter imaging. The TMI consists of 35 sodium iodide (NaI) crystals 5x5x2 in3 each, arranged in a random coded aperture mask array (CA), followed by 30 position sensitive NaI bars each 24x2.5x3 in3 called the detection array (DA). The CA array acts as both a coded aperture mask and scattering detector for Compton events. The large-area DA array acts as a collection detector for both Compton scattered events and coded aperture events. In this thesis, developed coded aperture, Compton and hybrid imaging algorithms will be described along with their performance. It will be shown that multiple imaging modalities can be fused to improve detection sensitivity over a broader energy range than either alone. Since the TMI is a moving system, peripheral data, such as a Global Positioning System (GPS) and Inertial Navigation System (INS) must also be incorporated. A method of adapting static imaging algorithms to a moving platform has been developed. Also, algorithms were developed in parallel with detector hardware, through the use of extensive simulations performed with the Geometry and Tracking Toolkit v4 (GEANT4). Simulations have been well validated against measured data. Results of image reconstruction algorithms at various speeds and distances will be presented as well as

Field-programmable beam reconfiguring based on digitally-controlled coding metasurface

Science.gov (United States)

Wan, Xiang; Qi, Mei Qing; Chen, Tian Yi; Cui, Tie Jun

2016-02-01

Digital phase shifters have been applied in traditional phased array antennas to realize beam steering. However, the phase shifter deals with the phase of the induced current; hence, it has to be in the path of each element of the antenna array, making the phased array antennas very expensive. Metamaterials and/or metasurfaces enable the direct modulation of electromagnetic waves by designing subwavelength structures, which opens a new way to control the beam scanning. Here, we present a direct digital mechanism to control the scattered electromagnetic waves using coding metasurface, in which each unit cell loads a pin diode to produce binary coding states of “1” and “0”. Through data lines, the instant communications are established between the coding metasurface and the internal memory of field-programmable gate arrays (FPGA). Thus, we realize the digital modulation of electromagnetic waves, from which we present the field-programmable reflective antenna with good measurement performance. The proposed mechanism and functional device have great application potential in new-concept radar and communication systems.

Control console for the X-ray room; Consola de control para la sala de rayos X

Energy Technology Data Exchange (ETDEWEB)

Garcia H, J.M.; Aguilar B, M.A.; Torres B, M.A

1998-07-01

It is presented the design and construction of Control console for the X-ray room of Metrology Center for ionizing radiations at National Institute of Nuclear Research (ININ). This system controls the positioning of 6 different filters for an X-ray beam. Also it controls a shutter which blockades the beam during periods established by user, these periods can be fixed from hours until tenth of second. The shutter opening periods, as well as the X-ray beam filter are establish and monitoring from a Personal computer outside of room. (Author)

Epp: A C++ EGSnrc user code for x-ray imaging and scattering simulations

International Nuclear Information System (INIS)

Lippuner, Jonas; Elbakri, Idris A.; Cui Congwu; Ingleby, Harry R.

2011-01-01

Purpose: Easy particle propagation (Epp) is a user code for the EGSnrc code package based on the C++ class library egspp. A main feature of egspp (and Epp) is the ability to use analytical objects to construct simulation geometries. The authors developed Epp to facilitate the simulation of x-ray imaging geometries, especially in the case of scatter studies. While direct use of egspp requires knowledge of C++, Epp requires no programming experience. Methods: Epp's features include calculation of dose deposited in a voxelized phantom and photon propagation to a user-defined imaging plane. Projection images of primary, single Rayleigh scattered, single Compton scattered, and multiple scattered photons may be generated. Epp input files can be nested, allowing for the construction of complex simulation geometries from more basic components. To demonstrate the imaging features of Epp, the authors simulate 38 keV x rays from a point source propagating through a water cylinder 12 cm in diameter, using both analytical and voxelized representations of the cylinder. The simulation generates projection images of primary and scattered photons at a user-defined imaging plane. The authors also simulate dose scoring in the voxelized version of the phantom in both Epp and DOSXYZnrc and examine the accuracy of Epp using the Kawrakow-Fippel test. Results: The results of the imaging simulations with Epp using voxelized and analytical descriptions of the water cylinder agree within 1%. The results of the Kawrakow-Fippel test suggest good agreement between Epp and DOSXYZnrc. Conclusions: Epp provides the user with useful features, including the ability to build complex geometries from simpler ones and the ability to generate images of scattered and primary photons. There is no inherent computational time saving arising from Epp, except for those arising from egspp's ability to use analytical representations of simulation geometries. Epp agrees with DOSXYZnrc in dose calculation, since

Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, and Human Health and Safety

Science.gov (United States)

Atwell, William; Koontz, Steve; Normand, Eugene

2012-01-01

Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport

Simulation the spatial resolution of an X-ray imager based on zinc oxide nanowires in anodic aluminium oxide membrane by using MCNP and OPTICS Codes

Science.gov (United States)

Samarin, S. N.; Saramad, S.

2018-05-01

The spatial resolution of a detector is a very important parameter for x-ray imaging. A bulk scintillation detector because of spreading of light inside the scintillator does't have a good spatial resolution. The nanowire scintillators because of their wave guiding behavior can prevent the spreading of light and can improve the spatial resolution of traditional scintillation detectors. The zinc oxide (ZnO) scintillator nanowire, with its simple construction by electrochemical deposition in regular hexagonal structure of Aluminum oxide membrane has many advantages. The three dimensional absorption of X-ray energy in ZnO scintillator is simulated by a Monte Carlo transport code (MCNP). The transport, attenuation and scattering of the generated photons are simulated by a general-purpose scintillator light response simulation code (OPTICS). The results are compared with a previous publication which used a simulation code of the passage of particles through matter (Geant4). The results verify that this scintillator nanowire structure has a spatial resolution less than one micrometer.

Quality control of diagnostic x-ray equipment and film processing

International Nuclear Information System (INIS)

1993-01-01

According to the section 40 of the Radiation Act (592/92), the licensee is required in Finland to make the arrangements to control the function of the radiation equipment and related facilities used for medical procedures. The guide explains how quality control can be organized for diagnostic x-ray equipment. It also gives recommendations for constancy tests for conventional x-ray radiographic and fluoroscopic equipment and for film processing. The recommendations are based on the publications and statements of the International Committee for Radiation Protection (ICRP) and standardization organizations. The intention is that the operators of x-ray equipment or the maintenance personnel are able to perform the quality control tests presented in the guide

Auto Code Generation for Simulink-Based Attitude Determination Control System

Science.gov (United States)

MolinaFraticelli, Jose Carlos

2012-01-01

This paper details the work done to auto generate C code from a Simulink-Based Attitude Determination Control System (ADCS) to be used in target platforms. NASA Marshall Engineers have developed an ADCS Simulink simulation to be used as a component for the flight software of a satellite. This generated code can be used for carrying out Hardware in the loop testing of components for a satellite in a convenient manner with easily tunable parameters. Due to the nature of the embedded hardware components such as microcontrollers, this simulation code cannot be used directly, as it is, on the target platform and must first be converted into C code; this process is known as auto code generation. In order to generate C code from this simulation; it must be modified to follow specific standards set in place by the auto code generation process. Some of these modifications include changing certain simulation models into their atomic representations which can bring new complications into the simulation. The execution order of these models can change based on these modifications. Great care must be taken in order to maintain a working simulation that can also be used for auto code generation. After modifying the ADCS simulation for the auto code generation process, it is shown that the difference between the output data of the former and that of the latter is between acceptable bounds. Thus, it can be said that the process is a success since all the output requirements are met. Based on these results, it can be argued that this generated C code can be effectively used by any desired platform as long as it follows the specific memory requirements established in the Simulink Model.

Gamma ray attenuation coefficient measurement for neutron-absorbent materials

International Nuclear Information System (INIS)

Jalali, Majid; Mohammadi, Ali

2008-01-01

The compounds Na 2 B 4 O 7 , H 3 BO 3 , CdCl 2 and NaCl and their solutions attenuate gamma rays in addition to neutron absorption. These compounds are widely used in the shielding of neutron sources, reactor control and neutron converters. Mass attenuation coefficients of gamma related to the four compounds aforementioned, in energies 662, 778.9, 867.38, 964.1, 1085.9, 1173, 1212.9, 1299.1,1332 and 1408 keV, have been determined by the γ rays transmission method in a good geometry setup; also, these coefficients were calculated by MCNP code. A comparison between experiments, simulations and Xcom code has shown that the study has potential application for determining the attenuation coefficient of various compound materials. Experiment and computation show that H 3 BO 3 with the lowest average Z has the highest gamma ray attenuation coefficient among the aforementioned compounds

Hydrodynamic evolution of plasma waveguides for soft-x-ray amplifiers

Science.gov (United States)

Oliva, Eduardo; Depresseux, Adrien; Cotelo, Manuel; Lifschitz, Agustín; Tissandier, Fabien; Gautier, Julien; Maynard, Gilles; Velarde, Pedro; Sebban, Stéphane

2018-02-01

High-density, collisionally pumped plasma-based soft-x-ray lasers have recently delivered hundreds of femtosecond pulses, breaking the longstanding barrier of one picosecond. To pump these amplifiers an intense infrared pulse must propagate focused throughout all the length of the amplifier, which spans several Rayleigh lengths. However, strong nonlinear effects hinder the propagation of the laser beam. The use of a plasma waveguide allows us to overcome these drawbacks provided the hydrodynamic processes that dominate the creation and posterior evolution of the waveguide are controlled and optimized. In this paper we present experimental measurements of the radial density profile and transmittance of such waveguide, and we compare them with numerical calculations using hydrodynamic and particle-in-cell codes. Controlling the properties (electron density value and radial gradient) of the waveguide with the help of numerical codes promises the delivery of ultrashort (tens of femtoseconds), coherent soft-x-ray pulses.

DELIN and DELOG codes for graphic representation of gamma ray spectra; Programas DELIN y DELOG para la representacion grafica de espectros gamma

Energy Technology Data Exchange (ETDEWEB)

Romero, L; Travesi, A

1983-07-01

Two Fortran IV Codes has been developed for graphic representation of the gamma-ray spectra obtained with Ge Li detectors and multichannel analyzers. The grafic plotting es carried out with the H.P. Graphic Plotter Mod HP-7221 A, using the graphic package software GRAPHICS-1000 from Hewlett-Packard. The codes have a great versatility and the representation of gamma spectra can ba done in a lineal, semi log, or log-log scale, as desired. The gamma ray spectra data are feed into the computer through magnetic tape or perfored paper tape. The different out-put options and complementary data are given in a conversational way through a terminal with T.V. displays. Among the options that can be selected by the user are the following: - smoothing the spectra - drawing the spectra point by point or continuous - out-put drawing an 1, 2, or 4 sheet with automatic division of the energy scale. - overlapping of selected spectra regions in Y scale ampliation with automatic print-out of the region limits and ampliation factor. - Printing spectra data and identifications of selected photo peaks. The codes can be employed with any computer using printing devices, HP-Graphics 1000 software compatible, but are easily modified for another printing software since their modular structure with Fortran IV written.

Mutual control of X-rays and nuclear transitions

Energy Technology Data Exchange (ETDEWEB)

Gunst, Jonas Friedrich

2015-12-14

In the course of this Thesis the mutual control between X-rays and nuclear transitions is investigated theoretically. In the first Part, we study the nuclear photoexcitation with the highly brilliant and coherent X-ray free-electron lasers (XFELs). Apart from amplifying the direct resonant interaction with nuclear transitions, the super-intense XFEL can produce new states of matter like cold, high-density plasmas where secondary nuclear excitation channels may come into play, e.g., nuclear excitation by electron capture (NEEC). Our results predict that in the case of {sup 57}Fe targets secondary NEEC can be safely neglected, whereas it is surprisingly the dominating contribution (in comparison to the direct photoexcitation) for the XFEL-induced {sup 93m}Mo isomer triggering. Based on these case studies, we elaborate a general set of criteria to identify the prevailing excitation channel for a certain nuclear isotope. These criteria may be most relevant for future nuclear resonance experiments at XFEL facilities. On the opposite frontier, the interplay between single X-ray photons and nuclear transitions offer potential storage and processing applications for information science in their most compact form. In the second Part of this Thesis, we show that nuclear forward scattering off {sup 57}Fe targets can be employed to process polarization-encoded single X-rays via timed magnetic field rotations. Apart from the realization of logical gates with X-rays, the polarization encoding is used to design an X-ray quantum eraser scheme where the interference between scattering paths can be switched off and on in a controlled manner. Such setups may advance time-energy complementarity tests to so far unexplored parameter regimes, e.g., to the domain of X-ray quanta.

Quality control of X-ray irradiator by biological markers

International Nuclear Information System (INIS)

Miura, Miwa; Lukmanul Hakkim, F.; Yoshida, Masahiro; Matsuda, Naoki; Morita, Naoko

2011-01-01

The exposure of animals or cultured cells to radiation is the essential and common step in experimental researches to elucidate biological effects of radiation. When an X-ray generator is used as a radiation source, physical parameters including dose, dose rate, and the energy spectrum of X-ray play crucial roles in biological outcome. Therefore, those parameters are the important points to be checked in quality control and to be carefully considered in advance to the irradiation to obtain the accurate and reproductive results. Here we measured radiation dose emitted from the X-ray irradiator for research purposes by using clonogenic survival of cultured mammalian cells as a biological marker in parallel with physical dosimetry. The results drawn from both methods exhibited good consistency in the dose distribution on the irradiation stage. Furthermore, the close relationship was observed between cell survival and the photon energy spectrum by using different filter components. These results suggest that biological dosimetry is applicable to quality control of X-ray irradiator in adjunct to physical dosimetry and that it possibly helps better understanding of the optimal irradiating condition by X-ray users in life-science field. (author)

Survey of coded aperture imaging

International Nuclear Information System (INIS)

Barrett, H.H.

1975-01-01

The basic principle and limitations of coded aperture imaging for x-ray and gamma cameras are discussed. Current trends include (1) use of time varying apertures, (2) use of ''dilute'' apertures with transmission much less than 50%, and (3) attempts to derive transverse tomographic sections, unblurred by other planes, from coded images

Process-engineering control valves under the EC codes; Steuerventile fuer die Prozesstechnik im Geltungsbereich der EG-Richtlinien

Energy Technology Data Exchange (ETDEWEB)

Gohlke, B. [IMI Norgren Herion Fluidtronic GmbH und Co. KG, Fellbach (Germany)

2003-09-01

The European Parliament and European Council have enacted special codes in order to implement uniform conditions in all countries of the European Community. The manufacturers of technical and commercial products are obliged to adhere to these codes. Harmonized standards, which are to be used as a tool for the implementation of the codes, are embedded at another level of the overall 'European reference literature'. Two EC codes, in particular, are definitive for fluids engineering: On the one hand, the EC Machinery Code, 98/37/EC and, on the other hand, the EC Pressurized Equipment Code, 97/23/EC. These EC codes cover, inter alia, machinery and chemical process-engineering plants, and conventional power generating plants. Norgren-Herion, a manufacturer of fluid engineering components, perceived a necessity for positioning its control valves in the scope of applicability of the EC codes. This article describes experience with the EC codes from the control valve manufacturer's point of view and examines the various qualification procedures for control valves. (orig.)

Gamma ray attenuation coefficient measurement for neutron-absorbent materials

Energy Technology Data Exchange (ETDEWEB)

Jalali, Majid [Isfahan Nuclear Science and Technology Research Institute (NSTRT), Reactor and Accelerators Research and Development School, Atomic Energy Organization (Iran, Islamic Republic of)], E-mail: m_jalali@entc.org.ir; Mohammadi, Ali [Faculty of Science, Department of Physics, University of Kashan, Km. 6, Ravand Road, Kashan (Iran, Islamic Republic of)

2008-05-15

The compounds Na{sub 2}B{sub 4}O{sub 7}, H{sub 3}BO{sub 3}, CdCl{sub 2} and NaCl and their solutions attenuate gamma rays in addition to neutron absorption. These compounds are widely used in the shielding of neutron sources, reactor control and neutron converters. Mass attenuation coefficients of gamma related to the four compounds aforementioned, in energies 662, 778.9, 867.38, 964.1, 1085.9, 1173, 1212.9, 1299.1,1332 and 1408 keV, have been determined by the {gamma} rays transmission method in a good geometry setup; also, these coefficients were calculated by MCNP code. A comparison between experiments, simulations and Xcom code has shown that the study has potential application for determining the attenuation coefficient of various compound materials. Experiment and computation show that H{sub 3}BO{sub 3} with the lowest average Z has the highest gamma ray attenuation coefficient among the aforementioned compounds.

GRay: A MASSIVELY PARALLEL GPU-BASED CODE FOR RAY TRACING IN RELATIVISTIC SPACETIMES

Energy Technology Data Exchange (ETDEWEB)

Chan, Chi-kwan; Psaltis, Dimitrios; Özel, Feryal [Department of Astronomy, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States)

2013-11-01

We introduce GRay, a massively parallel integrator designed to trace the trajectories of billions of photons in a curved spacetime. This graphics-processing-unit (GPU)-based integrator employs the stream processing paradigm, is implemented in CUDA C/C++, and runs on nVidia graphics cards. The peak performance of GRay using single-precision floating-point arithmetic on a single GPU exceeds 300 GFLOP (or 1 ns per photon per time step). For a realistic problem, where the peak performance cannot be reached, GRay is two orders of magnitude faster than existing central-processing-unit-based ray-tracing codes. This performance enhancement allows more effective searches of large parameter spaces when comparing theoretical predictions of images, spectra, and light curves from the vicinities of compact objects to observations. GRay can also perform on-the-fly ray tracing within general relativistic magnetohydrodynamic algorithms that simulate accretion flows around compact objects. Making use of this algorithm, we calculate the properties of the shadows of Kerr black holes and the photon rings that surround them. We also provide accurate fitting formulae of their dependencies on black hole spin and observer inclination, which can be used to interpret upcoming observations of the black holes at the center of the Milky Way, as well as M87, with the Event Horizon Telescope.

LUCID - an optical design and raytrace code

International Nuclear Information System (INIS)

Nicholas, D.J.; Duffey, K.P.

1980-11-01

A 2D optical design and ray trace code is described. The code can operate either as a geometric optics propagation code or provide a scalar diffraction treatment. There are numerous non-standard options within the code including design and systems optimisation procedures. A number of illustrative problems relating to the design of optical components in the field of high power lasers is included. (author)

ARES: automated response function code. Users manual

International Nuclear Information System (INIS)

Maung, T.; Reynolds, G.M.

1981-06-01

This ARES user's manual provides detailed instructions for a general understanding of the Automated Response Function Code and gives step by step instructions for using the complete code package on a HP-1000 system. This code is designed to calculate response functions of NaI gamma-ray detectors, with cylindrical or rectangular geometries

THIDA: code system for calculation of the exposure dose rate around a fusion device

International Nuclear Information System (INIS)

Iida, Hiromasa; Igarashi, Masahito.

1978-12-01

A code system THIDA has been developed for calculation of the exposure dose rates around a fusion device. It consists of the following: one- and two-dimensional discrete ordinate transport codes; induced activity calculation code; activation chain, activation cross section, radionuclide gamma-ray energy/intensity and gamma-ray group constant files; and gamma ray flux to exposure dose rate conversion coefficients. (author)

Software Certification - Coding, Code, and Coders

Science.gov (United States)

Havelund, Klaus; Holzmann, Gerard J.

2011-01-01

We describe a certification approach for software development that has been adopted at our organization. JPL develops robotic spacecraft for the exploration of the solar system. The flight software that controls these spacecraft is considered to be mission critical. We argue that the goal of a software certification process cannot be the development of "perfect" software, i.e., software that can be formally proven to be correct under all imaginable and unimaginable circumstances. More realistically, the goal is to guarantee a software development process that is conducted by knowledgeable engineers, who follow generally accepted procedures to control known risks, while meeting agreed upon standards of workmanship. We target three specific issues that must be addressed in such a certification procedure: the coding process, the code that is developed, and the skills of the coders. The coding process is driven by standards (e.g., a coding standard) and tools. The code is mechanically checked against the standard with the help of state-of-the-art static source code analyzers. The coders, finally, are certified in on-site training courses that include formal exams.

Shield device for controlling the dose of x-rays applied in an x-ray machine

International Nuclear Information System (INIS)

Charrier, P.

1983-01-01

This invention provides an improved shield for use with an x-ray machine. The shield can control the dose of x-rays applied by the machine in different areas without affecting the power of the x-rays. This is achieved with a shield especially designed and positioned to intercept with x-rays for longer or shorter periods in different areas during the taking of the picture, but not for the whole period of time necessary for taking this picture. Each area of the subject being x-rayed is exposed to full power x-rays. However, owing to the shield, the areas that require smaller dose receive these full power x-rays for a shorter portion of the time required to take the picture while the other areas that require larger dose of x-rays, receive the full power x-rays for a longer portion of the full period of time required to take the picture. To ensure this differential exposure, the shield is placed through the path of the x-rays and rotated about an axis which is generally transverse to the direction of travel of the x-rays to cut out some of said x-rays for different portions of the period of time necessary for taking the picture. The shield is preferably shaped to intercept x-rays for a longer period in some areas than in others depending on the required doses. A plurality of differently shaped shields can be provided to suit different picture taking situations

X-ray conditions and response characteristics of automatic dose control in cinematography

International Nuclear Information System (INIS)

Arai, Hiroaki

1997-01-01

X-ray characteristics including subject thickness (copper plate), tube voltage, tube current and irradiation time were measured at stability, with an automatic dose control x-ray generator for cineangiography. Regardless of subject thickness, it is possible that the energy input to the x-ray tube in one frame may be decreased. The automatic control response was measured after rapid fluctuation in subject thickness. Two inverter-type x-ray generators with different automatic control units were studied. The older control unit changes exposure dose by tube voltage and tube current, while the newer one changes exposure dose by tube voltage, tube current and irradiation time. The maximum rate of change in tube voltage is greater with the newer control unit. In addition, the actual tube current response of the newer control unit in increasing nominal value is faster than the older one. In the new control unit, for each pulse, irradiation is cut off by means of a signal that the exposure has reached the proper value. Thus given the same differential in subject thickness, the newer control unit resumed stability faster than the older one. (author)

X-ray conditions and response characteristics of automatic dose control in cinematography

Energy Technology Data Exchange (ETDEWEB)

Arai, Hiroaki [Cardiovascular Institute Hospital, Tokyo (Japan)

1997-11-01

X-ray characteristics including subject thickness (copper plate), tube voltage, tube current and irradiation time were measured at stability, with an automatic dose control x-ray generator for cineangiography. Regardless of subject thickness, it is possible that the energy input to the x-ray tube in one frame may be decreased. The automatic control response was measured after rapid fluctuation in subject thickness. Two inverter-type x-ray generators with different automatic control units were studied. The older control unit changes exposure dose by tube voltage and tube current, while the newer one changes exposure dose by tube voltage, tube current and irradiation time. The maximum rate of change in tube voltage is greater with the newer control unit. In addition, the actual tube current response of the newer control unit in increasing nominal value is faster than the older one. In the new control unit, for each pulse, irradiation is cut off by means of a signal that the exposure has reached the proper value. Thus given the same differential in subject thickness, the newer control unit resumed stability faster than the older one. (author)

Use and regulatory control of dental X-ray installations

International Nuclear Information System (INIS)

1999-01-01

In the guide the safety requirements concerning dental X-ray installations and their use, prerequisities for exemption from a safety licence, and regulatory control are presented. The guide applies to conventional dental X-ray installations, by which an image is created on an X-ray film or other image receptor placed inside the mouth, and panorama tomography installations for dentition and the cephalostats associated with these. The guide does not apply to multitechnique tomography installations intended for the special imaging of the skull or jaws

Achievements in testing of the MGA and FRAM isotopic software codes under the DOE/NNSA-IRSN cooperation of gamma-ray isotopic measurement systems

International Nuclear Information System (INIS)

Vo, Duc; Wang, Tzu-Fang; Funk, Pierre; Weber, Anne-Laure; Pepin, Nicolas; Karcher, Anna

2009-01-01

DOE/NNSA and IRSN collaborated on a study of gamma-ray instruments and analysis methods used to perform isotopic measurements of special nuclear materials. The two agencies agreed to collaborate on the project in response to inconsistencies that were found in the various versions of software and hardware used to determine the isotopic abundances of uranium and plutonium. IRSN used software developed internally to test the MGA and FRAM isotopic analysis codes for criteria used to stop data acquisition. The stop-criterion test revealed several unusual behaviors in both the MGA and FRAM software codes.

Implementing displacement damage calculations for electrons and gamma rays in the Particle and Heavy-Ion Transport code System

Science.gov (United States)

Iwamoto, Yosuke

2018-03-01

In this study, the Monte Carlo displacement damage calculation method in the Particle and Heavy-Ion Transport code System (PHITS) was improved to calculate displacements per atom (DPA) values due to irradiation by electrons (or positrons) and gamma rays. For the damage due to electrons and gamma rays, PHITS simulates electromagnetic cascades using the Electron Gamma Shower version 5 (EGS5) algorithm and calculates DPA values using the recoil energies and the McKinley-Feshbach cross section. A comparison of DPA values calculated by PHITS and the Monte Carlo assisted Classical Method (MCCM) reveals that they were in good agreement for gamma-ray irradiations of silicon and iron at energies that were less than 10 MeV. Above 10 MeV, PHITS can calculate DPA values not only for electrons but also for charged particles produced by photonuclear reactions. In DPA depth distributions under electron and gamma-ray irradiations, build-up effects can be observed near the target's surface. For irradiation of 90-cm-thick carbon by protons with energies of more than 30 GeV, the ratio of the secondary electron DPA values to the total DPA values is more than 10% and increases with an increase in incident energy. In summary, PHITS can calculate DPA values for all particles and materials over a wide energy range between 1 keV and 1 TeV for electrons, gamma rays, and charged particles and between 10-5 eV and 1 TeV for neutrons.

Distinguishing stimulus and response codes in theta oscillations in prefrontal areas during inhibitory control of automated responses.

Science.gov (United States)

Mückschel, Moritz; Dippel, Gabriel; Beste, Christian

2017-11-01

Response inhibition mechanisms are mediated via cortical and subcortical networks. At the cortical level, the superior frontal gyrus, including the supplementary motor area (SMA) and inferior frontal areas, is important. There is an ongoing debate about the functional roles of these structures during response inhibition as it is unclear whether these structures process different codes or contents of information during response inhibition. In the current study, we examined this question with a focus on theta frequency oscillations during response inhibition processes. We used a standard Go/Nogo task in a sample of human participants and combined different EEG signal decomposition methods with EEG beamforming approaches. The results suggest that stimulus coding during inhibitory control is attained by oscillations in the upper theta frequency band (∼7 Hz). In contrast, response selection codes during inhibitory control appear to be attained by the lower theta frequency band (∼4 Hz). Importantly, these different codes seem to be processed in distinct functional neuroanatomical structures. Although the SMA may process stimulus codes and response selection codes, the inferior frontal cortex may selectively process response selection codes during inhibitory control. Taken together, the results suggest that different entities within the functional neuroanatomical network associated with response inhibition mechanisms process different kinds of codes during inhibitory control. These codes seem to be reflected by different oscillations within the theta frequency band. Hum Brain Mapp 38:5681-5690, 2017. © 2017 Wiley-Liss, Inc. © 2017 Wiley Periodicals, Inc.

Code Samples Used for Complexity and Control

Science.gov (United States)

Ivancevic, Vladimir G.; Reid, Darryn J.

2015-11-01

The following sections are included: * MathematicaⓇ Code * Generic Chaotic Simulator * Vector Differential Operators * NLS Explorer * 2C++ Code * C++ Lambda Functions for Real Calculus * Accelerometer Data Processor * Simple Predictor-Corrector Integrator * Solving the BVP with the Shooting Method * Linear Hyperbolic PDE Solver * Linear Elliptic PDE Solver * Method of Lines for a Set of the NLS Equations * C# Code * Iterative Equation Solver * Simulated Annealing: A Function Minimum * Simple Nonlinear Dynamics * Nonlinear Pendulum Simulator * Lagrangian Dynamics Simulator * Complex-Valued Crowd Attractor Dynamics * Freeform Fortran Code * Lorenz Attractor Simulator * Complex Lorenz Attractor * Simple SGE Soliton * Complex Signal Presentation * Gaussian Wave Packet * Hermitian Matrices * Euclidean L2-Norm * Vector/Matrix Operations * Plain C-Code: Levenberg-Marquardt Optimizer * Free Basic Code: 2D Crowd Dynamics with 3000 Agents

The influence of distrubing effects on the performance of a wide field coded mask X-ray camera

International Nuclear Information System (INIS)

Sims, M.R.; Turner, M.J.L.; Willingale, R.

1985-01-01

The coded aperture telescope, or Dicke camera, is seen as an instrument suitable for many applications in X-ray and gamma ray imaging. In this paper the effects of a partially obscuring window mask support or collimator, a detector with limited spatial resolution, and motion of the camera during image integration are considered using a computer simulation of the performance of such a camera. Cross correlation and the Wiener filter are used to deconvolve the data. It is shown that while these effects cause a degradation in performance this is in no case catastrophic. Deterioration of the image is shown to be greatest where strong sources are present in the field of view and is quite small (proportional 10%) when diffuse background is the major element. A comparison between the cyclic mask camera and the single mask camera is made under various conditions and it is shown the single mask camera has a moderate advantage particularly when imaging a wide field of view. (orig.)

High energy gamma ray response of liquid scintillator

International Nuclear Information System (INIS)

Shigyo, N.; Ishibashi, K.; Matsufuji, N.; Nakamoto, T.; Numajiri, M.

1994-01-01

We made the experiment on the spallation reaction. NE213 organic liquid scintillators were used for measuring neutrons and γ rays. To produce the γ ray emission cross section, we used the response functions by EGS4 code. The response functions look like uniform above γ ray energies of 60 MeV. The experimental data of the γ ray emission cross section are different from the data of High Energy Transport Code. (author)

Training and support to improve ICD coding quality: A controlled before-and-after impact evaluation.

Science.gov (United States)

Dyers, Robin; Ward, Grant; Du Plooy, Shane; Fourie, Stephanus; Evans, Juliet; Mahomed, Hassan

2017-05-24

The proposed National Health Insurance policy for South Africa (SA) requires hospitals to maintain high-quality International Statistical Classification of Diseases (ICD) codes for patient records. While considerable strides had been made to improve ICD coding coverage by digitising the discharge process in the Western Cape Province, further intervention was required to improve data quality. The aim of this controlled before-and-after study was to evaluate the impact of a clinician training and support initiative to improve ICD coding quality. To compare ICD coding quality between two central hospitals in the Western Cape before and after the implementation of a training and support initiative for clinicians at one of the sites. The difference in differences in data quality between the intervention site and the control site was calculated. Multiple logistic regression was also used to determine the odds of data quality improvement after the intervention and to adjust for potential differences between the groups. The intervention had a positive impact of 38.0% on ICD coding completeness over and above changes that occurred at the control site. Relative to the baseline, patient records at the intervention site had a 6.6 (95% confidence interval 3.5 - 16.2) adjusted odds ratio of having a complete set of ICD codes for an admission episode after the introduction of the training and support package. The findings on impact on ICD coding accuracy were not significant. There is sufficient pragmatic evidence that a training and support package will have a considerable positive impact on ICD coding completeness in the SA setting.

Sub-atomic dimensional metrology: developments in the control of x-ray interferometers

Science.gov (United States)

Yacoot, Andrew; Kuetgens, Ulrich

2012-07-01

Within the European Metrology Research Programme funded project NANOTRACE, the nonlinearity of the next generation of optical interferometers has been measured using x-ray interferometry. The x-ray interferometer can be regarded as a ruler or translation stage whose graduations or displacement steps are based on the lattice spacing of the crystallographic planes from which the x-rays are diffracted: in this case the graduations are every 192 pm corresponding to the spacing between the (2 2 0) planes in silicon. Precise displacement of the x-ray interferometer's monolithic translation stage in steps corresponding to discrete numbers of x-ray fringes requires servo positioning capability at the picometre level. To achieve this very fine control, a digital control system has been developed which has opened up the potential for advances in metrology using x-ray interferometry that include quadrature counting of x-ray fringes.

Sub-atomic dimensional metrology: developments in the control of x-ray interferometers

International Nuclear Information System (INIS)

Yacoot, Andrew; Kuetgens, Ulrich

2012-01-01

Within the European Metrology Research Programme funded project NANOTRACE, the nonlinearity of the next generation of optical interferometers has been measured using x-ray interferometry. The x-ray interferometer can be regarded as a ruler or translation stage whose graduations or displacement steps are based on the lattice spacing of the crystallographic planes from which the x-rays are diffracted: in this case the graduations are every 192 pm corresponding to the spacing between the (2 2 0) planes in silicon. Precise displacement of the x-ray interferometer's monolithic translation stage in steps corresponding to discrete numbers of x-ray fringes requires servo positioning capability at the picometre level. To achieve this very fine control, a digital control system has been developed which has opened up the potential for advances in metrology using x-ray interferometry that include quadrature counting of x-ray fringes. (paper)

Development of Monte Carlo decay gamma-ray transport calculation system

Energy Technology Data Exchange (ETDEWEB)

Sato, Satoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Kawasaki, Nobuo [Fujitsu Ltd., Tokyo (Japan); Kume, Etsuo [Japan Atomic Energy Research Inst., Center for Promotion of Computational Science and Engineering, Tokai, Ibaraki (Japan)

2001-06-01

In the DT fusion reactor, it is critical concern to evaluate the decay gamma-ray biological dose rates after the reactor shutdown exactly. In order to evaluate the decay gamma-ray biological dose rates exactly, three dimensional Monte Carlo decay gamma-ray transport calculation system have been developed by connecting the three dimensional Monte Carlo particle transport calculation code and the induced activity calculation code. The developed calculation system consists of the following four functions. (1) The operational neutron flux distribution is calculated by the three dimensional Monte Carlo particle transport calculation code. (2) The induced activities are calculated by the induced activity calculation code. (3) The decay gamma-ray source distribution is obtained from the induced activities. (4) The decay gamma-rays are generated by using the decay gamma-ray source distribution, and the decay gamma-ray transport calculation is conducted by the three dimensional Monte Carlo particle transport calculation code. In order to reduce the calculation time drastically, a biasing system for the decay gamma-ray source distribution has been developed, and the function is also included in the present system. In this paper, the outline and the detail of the system, and the execution example are reported. The evaluation for the effect of the biasing system is also reported. (author)

SHOULD ONE USE THE RAY-BY-RAY APPROXIMATION IN CORE-COLLAPSE SUPERNOVA SIMULATIONS?

International Nuclear Information System (INIS)

Skinner, M. Aaron; Burrows, Adam; Dolence, Joshua C.

2016-01-01

We perform the first self-consistent, time-dependent, multi-group calculations in two dimensions (2D) to address the consequences of using the ray-by-ray+ transport simplification in core-collapse supernova simulations. Such a dimensional reduction is employed by many researchers to facilitate their resource-intensive calculations. Our new code (Fornax) implements multi-D transport, and can, by zeroing out transverse flux terms, emulate the ray-by-ray+ scheme. Using the same microphysics, initial models, resolution, and code, we compare the results of simulating 12, 15, 20, and 25 M ⊙ progenitor models using these two transport methods. Our findings call into question the wisdom of the pervasive use of the ray-by-ray+ approach. Employing it leads to maximum post-bounce/pre-explosion shock radii that are almost universally larger by tens of kilometers than those derived using the more accurate scheme, typically leaving the post-bounce matter less bound and artificially more “explodable.” In fact, for our 25 M ⊙ progenitor, the ray-by-ray+ model explodes, while the corresponding multi-D transport model does not. Therefore, in two dimensions, the combination of ray-by-ray+ with the axial sloshing hydrodynamics that is a feature of 2D supernova dynamics can result in quantitatively, and perhaps qualitatively, incorrect results.

Internal Corrosion Control of Water Supply Systems Code of Practice

Science.gov (United States)

This Code of Practice is part of a series of publications by the IWA Specialist Group on Metals and Related Substances in Drinking Water. It complements the following IWA Specialist Group publications: 1. Best Practice Guide on the Control of Lead in Drinking Water 2. Best Prac...

Computing Challenges in Coded Mask Imaging

Science.gov (United States)

Skinner, Gerald

2009-01-01

This slide presaentation reviews the complications and challenges in developing computer systems for Coded Mask Imaging telescopes. The coded mask technique is used when there is no other way to create the telescope, (i.e., when there are wide fields of view, high energies for focusing or low energies for the Compton/Tracker Techniques and very good angular resolution.) The coded mask telescope is described, and the mask is reviewed. The coded Masks for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) instruments are shown, and a chart showing the types of position sensitive detectors used for the coded mask telescopes is also reviewed. Slides describe the mechanism of recovering an image from the masked pattern. The correlation with the mask pattern is described. The Matrix approach is reviewed, and other approaches to image reconstruction are described. Included in the presentation is a review of the Energetic X-ray Imaging Survey Telescope (EXIST) / High Energy Telescope (HET), with information about the mission, the operation of the telescope, comparison of the EXIST/HET with the SWIFT/BAT and details of the design of the EXIST/HET.

A multiplex coding imaging spectrometer for X-ray astronomy

International Nuclear Information System (INIS)

Rocchia, R.; Deschamps, J.Y.; Koch-Miramond, L.; Tarrius, A.

1985-06-01

The paper describes a multiplex coding system associated with a solid state spectrometer Si(Li) designed to be placed at the focus of a grazing incidence telescope. In this instrument the spectrometric and imaging functions are separated. The coding system consists in a movable mask with pseudo randomly distributed holes, located in the focal plane of the telescope. The pixel size lies in the range 100-200 microns. The close association of the coding system with a Si(Li) detector gives an imaging spectrometer combining the good efficiency (50% between 0,5 and 10 keV) and energy resolution (ΔE approximately 90 to 160 eV) of solid state spectrometers with the spatial resolution of the mask. Simulations and results obtained with a laboratory model are presented

Training and support to improve ICD coding quality: A controlled before-and-after impact evaluation

Directory of Open Access Journals (Sweden)

Robin Dyers

2017-06-01

Full Text Available Background. The proposed National Health Insurance policy for South Africa (SA requires hospitals to maintain high-quality International Statistical Classification of Diseases (ICD codes for patient records. While considerable strides had been made to improve ICD coding coverage by digitising the discharge process in the Western Cape Province, further intervention was required to improve data quality. The aim of this controlled before-and-after study was to evaluate the impact of a clinician training and support initiative to improve ICD coding quality. Objective. To compare ICD coding quality between two central hospitals in the Western Cape before and after the implementation of a training and support initiative for clinicians at one of the sites. Methods. The difference in differences in data quality between the intervention site and the control site was calculated. Multiple logistic regression was also used to determine the odds of data quality improvement after the intervention and to adjust for potential differences between the groups. Results. The intervention had a positive impact of 38.0% on ICD coding completeness over and above changes that occurred at the control site. Relative to the baseline, patient records at the intervention site had a 6.6 (95% confidence interval 3.5 - 16.2 adjusted odds ratio of having a complete set of ICD codes for an admission episode after the introduction of the training and support package. The findings on impact on ICD coding accuracy were not significant. Conclusion. There is sufficient pragmatic evidence that a training and support package will have a considerable positive impact on ICD coding completeness in the SA setting.

Controlled dense coding for continuous variables using three-particle entangled states

CERN Document Server

Jing Zhang; Kun Chi Peng; 10.1103/PhysRevA.66.032318

2002-01-01

A simple scheme to realize quantum controlled dense coding with a bright tripartite entangled state light generated from nondegenerate optical parametric amplifiers is proposed in this paper. The quantum channel between Alice and Bob is controlled by Claire. As a local oscillator and balanced homodyne detector are not needed, the proposed protocol is easy to be realized experimentally. (15 refs)

Phototimer for automatic control of x-ray exposure, PT-20A

Energy Technology Data Exchange (ETDEWEB)

Ohno, H; Itoh, K; Ogura, I; Yasuhara, H; Sugimoto, H [Toshiba Corp., Kawasaki, Kanagawa (Japan)

1979-02-01

The phototimer as an exposure control device is now required to have higher accuracy and wider range of control to comply with the recent trends of x-ray diagnosis, such as toward short-time exposure due to increased output power of x-ray apparatus and toward one-man operation. In order to meet the requirement, the x-ray characteristics of the components of the phototimer have been examined, and computer simulation of x-ray spectra and dynamic characteristics of every component have been investigated, in pursuit of the essential characters of phototimers. On the basis of these analytical investigations, the phototimer PT-20A is so designed as to compensate for density deviation under various kVp and object thickness: uniform density has been obtained under practical radiographic conditions.

Systemizers Are Better Code-Breakers: Self-Reported Systemizing Predicts Code-Breaking Performance in Expert Hackers and Naïve Participants

Science.gov (United States)

Harvey, India; Bolgan, Samuela; Mosca, Daniel; McLean, Colin; Rusconi, Elena

2016-01-01

Studies on hacking have typically focused on motivational aspects and general personality traits of the individuals who engage in hacking; little systematic research has been conducted on predispositions that may be associated not only with the choice to pursue a hacking career but also with performance in either naïve or expert populations. Here, we test the hypotheses that two traits that are typically enhanced in autism spectrum disorders—attention to detail and systemizing—may be positively related to both the choice of pursuing a career in information security and skilled performance in a prototypical hacking task (i.e., crypto-analysis or code-breaking). A group of naïve participants and of ethical hackers completed the Autism Spectrum Quotient, including an attention to detail scale, and the Systemizing Quotient (Baron-Cohen et al., 2001, 2003). They were also tested with behavioral tasks involving code-breaking and a control task involving security X-ray image interpretation. Hackers reported significantly higher systemizing and attention to detail than non-hackers. We found a positive relation between self-reported systemizing (but not attention to detail) and code-breaking skills in both hackers and non-hackers, whereas attention to detail (but not systemizing) was related with performance in the X-ray screening task in both groups, as previously reported with naïve participants (Rusconi et al., 2015). We discuss the theoretical and translational implications of our findings. PMID:27242491

Systemizers are better code-breakers:Self-reported systemizing predicts code-breaking performance in expert hackers and naïve participants

Directory of Open Access Journals (Sweden)

India eHarvey

2016-05-01

Full Text Available Studies on hacking have typically focused on motivational aspects and general personality traits of the individuals who engage in hacking; little systematic research has been conducted on predispositions that may be associated not only with the choice to pursue a hacking career but also with performance in either naïve or expert populations. Here we test the hypotheses that two traits that are typically enhanced in autism spectrum disorders - attention to detail and systemizing - may be positively related to both the choice of pursuing a career in information security and skilled performance in a prototypical hacking task (i.e. crypto-analysis or code-breaking. A group of naïve participants and of ethical hackers completed the Autism Spectrum Quotient, including an attention to detail scale, and the Systemizing Quotient (Baron-Cohen et al., 2001; Baron-Cohen et al., 2003. They were also tested with behavioural tasks involving code-breaking and a control task involving security x-ray image interpretation. Hackers reported significantly higher systemizing and attention to detail than non-hackers. We found a positive relation between self-reported systemizing (but not attention to detail and code-breaking skills in both hackers and non-hackers, whereas attention to detail (but not systemizing was related with performance in the x-ray screening task in both groups, as previously reported with naïve participants (Rusconi et al., 2015. We discuss the theoretical and translational implications of our findings.

Systemizers Are Better Code-Breakers: Self-Reported Systemizing Predicts Code-Breaking Performance in Expert Hackers and Naïve Participants.

Science.gov (United States)

Harvey, India; Bolgan, Samuela; Mosca, Daniel; McLean, Colin; Rusconi, Elena

2016-01-01

Studies on hacking have typically focused on motivational aspects and general personality traits of the individuals who engage in hacking; little systematic research has been conducted on predispositions that may be associated not only with the choice to pursue a hacking career but also with performance in either naïve or expert populations. Here, we test the hypotheses that two traits that are typically enhanced in autism spectrum disorders-attention to detail and systemizing-may be positively related to both the choice of pursuing a career in information security and skilled performance in a prototypical hacking task (i.e., crypto-analysis or code-breaking). A group of naïve participants and of ethical hackers completed the Autism Spectrum Quotient, including an attention to detail scale, and the Systemizing Quotient (Baron-Cohen et al., 2001, 2003). They were also tested with behavioral tasks involving code-breaking and a control task involving security X-ray image interpretation. Hackers reported significantly higher systemizing and attention to detail than non-hackers. We found a positive relation between self-reported systemizing (but not attention to detail) and code-breaking skills in both hackers and non-hackers, whereas attention to detail (but not systemizing) was related with performance in the X-ray screening task in both groups, as previously reported with naïve participants (Rusconi et al., 2015). We discuss the theoretical and translational implications of our findings.

EXTRAN: A computer code for estimating concentrations of toxic substances at control room air intakes

International Nuclear Information System (INIS)

Ramsdell, J.V.

1991-03-01

This report presents the NRC staff with a tool for assessing the potential effects of accidental releases of radioactive materials and toxic substances on habitability of nuclear facility control rooms. The tool is a computer code that estimates concentrations at nuclear facility control room air intakes given information about the release and the environmental conditions. The name of the computer code is EXTRAN. EXTRAN combines procedures for estimating the amount of airborne material, a Gaussian puff dispersion model, and the most recent algorithms for estimating diffusion coefficients in building wakes. It is a modular computer code, written in FORTRAN-77, that runs on personal computers. It uses a math coprocessor, if present, but does not require one. Code output may be directed to a printer or disk files. 25 refs., 8 figs., 4 tabs

TASS code topical report. V.1 TASS code technical manual

International Nuclear Information System (INIS)

Sim, Suk K.; Chang, W. P.; Kim, K. D.; Kim, H. C.; Yoon, H. Y.

1997-02-01

TASS 1.0 code has been developed at KAERI for the initial and reload non-LOCA safety analysis for the operating PWRs as well as the PWRs under construction in Korea. TASS code will replace various vendor's non-LOCA safety analysis codes currently used for the Westinghouse and ABB-CE type PWRs in Korea. This can be achieved through TASS code input modifications specific to each reactor type. The TASS code can be run interactively through the keyboard operation. A simimodular configuration used in developing the TASS code enables the user easily implement new models. TASS code has been programmed using FORTRAN77 which makes it easy to install and port for different computer environments. The TASS code can be utilized for the steady state simulation as well as the non-LOCA transient simulations such as power excursions, reactor coolant pump trips, load rejections, loss of feedwater, steam line breaks, steam generator tube ruptures, rod withdrawal and drop, and anticipated transients without scram (ATWS). The malfunctions of the control systems, components, operator actions and the transients caused by the malfunctions can be easily simulated using the TASS code. This technical report describes the TASS 1.0 code models including reactor thermal hydraulic, reactor core and control models. This TASS code models including reactor thermal hydraulic, reactor core and control models. This TASS code technical manual has been prepared as a part of the TASS code manual which includes TASS code user's manual and TASS code validation report, and will be submitted to the regulatory body as a TASS code topical report for a licensing non-LOCA safety analysis for the Westinghouse and ABB-CE type PWRs operating and under construction in Korea. (author). 42 refs., 29 tabs., 32 figs

FERD and FERDOR type unfolding codes

International Nuclear Information System (INIS)

Burrus, W.R.

1976-01-01

FERD and FERDO are unfolding codes which were developed at the Neutron Physics Division of Oak Ridge National Laboratory in 1965 and 1966. FERDO variants such as FERDOR and FORIST have been widely used, and many useful supplementary procedures have been developed for neutron and gamma-ray spectroscopy and other diverse applications. Algorithms for the codes are discussed

Impact of thermoplastic mask on X-ray surface dose calculated with Monte Carlo code

International Nuclear Information System (INIS)

Zhao Yanqun; Li Jie; Wu Liping; Wang Pei; Lang Jinyi; Wu Dake; Xiao Mingyong

2010-01-01

Objective: To calculate the effects of thermoplastic mask on X-ray surface dose. Methods: The BEAMnrc Monte Carlo Code system, designed especially for computer simulation of radioactive sources, was performed to evaluate the effects of thermoplastic mask on X-ray surface dose.Thermoplastic mask came from our center with a material density of 1.12 g/cm 2 . The masks without holes, with holes size of 0.1 cm x 0.1 cm, and with holes size of 0. 1 cm x 0.2 cm, and masks with different depth (0.12 cm and 0.24 cm) were evaluated separately. For those with holes, the material width between adjacent holes was 0.1 cm. Virtual masks with a material density of 1.38 g/cm 3 without holes with two different depths were also evaluated. Results: Thermoplastic mask affected X-rays surface dose. When using a thermoplastic mask with the depth of 0.24 cm without holes, the surface dose was 74. 9% and 57.0% for those with the density of 1.38 g/cm 3 and 1.12 g/cm 3 respectively. When focusing on the masks with the density of 1.12 g/cm 3 , the surface dose was 41.2% for those with 0.12 cm depth without holes; 57.0% for those with 0. 24 cm depth without holes; 44.5% for those with 0.24 cm depth with holes size of 0.1 cm x 0.2 cm;and 54.1% for those with 0.24 cm depths with holes size of 0.1 cm x 0.1 cm.Conclusions: Using thermoplastic mask during the radiation increases patient surface dose. The severity is relative to the hole size and the depth of thermoplastic mask. The surface dose change should be considered in radiation planning to avoid severe skin reaction. (authors)

A Reaction-Diffusion-Based Coding Rate Control Mechanism for Camera Sensor Networks

Directory of Open Access Journals (Sweden)

Naoki Wakamiya

2010-08-01

Full Text Available A wireless camera sensor network is useful for surveillance and monitoring for its visibility and easy deployment. However, it suffers from the limited capacity of wireless communication and a network is easily overflown with a considerable amount of video traffic. In this paper, we propose an autonomous video coding rate control mechanism where each camera sensor node can autonomously determine its coding rate in accordance with the location and velocity of target objects. For this purpose, we adopted a biological model, i.e., reaction-diffusion model, inspired by the similarity of biological spatial patterns and the spatial distribution of video coding rate. Through simulation and practical experiments, we verify the effectiveness of our proposal.

A reaction-diffusion-based coding rate control mechanism for camera sensor networks.

Science.gov (United States)

Yamamoto, Hiroshi; Hyodo, Katsuya; Wakamiya, Naoki; Murata, Masayuki

2010-01-01

A wireless camera sensor network is useful for surveillance and monitoring for its visibility and easy deployment. However, it suffers from the limited capacity of wireless communication and a network is easily overflown with a considerable amount of video traffic. In this paper, we propose an autonomous video coding rate control mechanism where each camera sensor node can autonomously determine its coding rate in accordance with the location and velocity of target objects. For this purpose, we adopted a biological model, i.e., reaction-diffusion model, inspired by the similarity of biological spatial patterns and the spatial distribution of video coding rate. Through simulation and practical experiments, we verify the effectiveness of our proposal.

THE OPTIMAL CONTROL IN THE MODELOF NETWORK SECURITY FROM MALICIOUS CODE

Directory of Open Access Journals (Sweden)

2016-01-01

Full Text Available The paper deals with a mathematical model of network security. The model is described in terms of the nonlinear optimal control. As a criterion of the control problem quality the price of the summary damage inflicted by the harmful codes is chosen, under additional restriction: the number of recovered nodes is maximized. The Pontryagin maximum principle for construction of the optimal decisions is formulated. The number of switching points of the optimal control is found. The explicit form of optimal control is given using the Lagrange multipliers method.

SHOULD ONE USE THE RAY-BY-RAY APPROXIMATION IN CORE-COLLAPSE SUPERNOVA SIMULATIONS?

Energy Technology Data Exchange (ETDEWEB)

Skinner, M. Aaron; Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Dolence, Joshua C., E-mail: burrows@astro.princeton.edu, E-mail: askinner@astro.princeton.edu, E-mail: jdolence@lanl.gov [CCS-2, Los Alamos National Laboratory, P.O. Box 1663 Los Alamos, NM 87545 (United States)

2016-11-01

We perform the first self-consistent, time-dependent, multi-group calculations in two dimensions (2D) to address the consequences of using the ray-by-ray+ transport simplification in core-collapse supernova simulations. Such a dimensional reduction is employed by many researchers to facilitate their resource-intensive calculations. Our new code (Fornax) implements multi-D transport, and can, by zeroing out transverse flux terms, emulate the ray-by-ray+ scheme. Using the same microphysics, initial models, resolution, and code, we compare the results of simulating 12, 15, 20, and 25 M {sub ⊙} progenitor models using these two transport methods. Our findings call into question the wisdom of the pervasive use of the ray-by-ray+ approach. Employing it leads to maximum post-bounce/pre-explosion shock radii that are almost universally larger by tens of kilometers than those derived using the more accurate scheme, typically leaving the post-bounce matter less bound and artificially more “explodable.” In fact, for our 25 M {sub ⊙} progenitor, the ray-by-ray+ model explodes, while the corresponding multi-D transport model does not. Therefore, in two dimensions, the combination of ray-by-ray+ with the axial sloshing hydrodynamics that is a feature of 2D supernova dynamics can result in quantitatively, and perhaps qualitatively, incorrect results.

Quality control of the packet of RELAP5/MOD2 code

International Nuclear Information System (INIS)

Pomier Baez, L.E.

1993-01-01

The methodology that should be used to perform the quality control of entrance data set of RELAP5 calculation code is expounded in this work with this control method an extreme reliability is quarantined in the calculation model established to perform the safety thermohydraulic analysis with the help of RELAP5. This makes possible the complex simulation studies of a nuclear power plant with the quality required

Code Development for Control Design Applications: Phase I: Structural Modeling

International Nuclear Information System (INIS)

Bir, G. S.; Robinson, M.

1998-01-01

The design of integrated controls for a complex system like a wind turbine relies on a system model in an explicit format, e.g., state-space format. Current wind turbine codes focus on turbine simulation and not on system characterization, which is desired for controls design as well as applications like operating turbine model analysis, optimal design, and aeroelastic stability analysis. This paper reviews structural modeling that comprises three major steps: formation of component equations, assembly into system equations, and linearization

Moving the Frontier of Quantum Control into the Soft X-Ray Spectrum

Directory of Open Access Journals (Sweden)

A. Aquila

2011-01-01

Full Text Available The femtosecond nature of X-ray free electron laser (FEL pulses opens up exciting research possibilities in time-resolved studies including femtosecond photoemission and diffraction. The recent developments of seeding X-ray FELs extend their capabilities by creating stable, temporally coherent, and repeatable pulses. This in turn opens the possibility of spectral engineering soft X-ray pulses to use as a probe for the control of quantum dynamics. We propose a method for extending coherent control pulse-shaping techniques to the soft X-ray spectral range by using a reflective geometry 4f pulse shaper. This method is based on recent developments in asymmetrically cut multilayer optic technology and piezoelectric substrates.

A Toroidally Symmetric Plasma Simulation code for design of position and shape control on tokamak plasmas

International Nuclear Information System (INIS)

Takase, Haruhiko; Senda, Ikuo

1999-01-01

A Toroidally Symmetric Plasma Simulation (TSPS) code has been developed for investigating the position and shape control on tokamak plasmas. The analyses of three-dimensional eddy currents on the conducting components around the plasma and the two-dimensional magneto-hydrodynamic (MHD) equilibrium are taken into account in this code. The code can analyze the plasma position and shape control during the minor disruption in which the deformation of plasma is not negligible. Using the ITER (International Thermonuclear Experimental Reactor) parameters, some examples of calculations are shown in this paper. (author)

Gamma ray spectrum analysis code: sigmas 1.0

International Nuclear Information System (INIS)

Siangsanan, P.; Dharmavanij, W.; Chongkum, S.

1996-01-01

We have developed Sigmas 1.0 a software package for data reduction and gamma ray spectra evaluation. It is capable of analysing the gamma-ray spectrum in the range of 0-3 MeV by semiconductor detector, i.e. Ge(Li) or HPGe, peak searching, net area determining, plotting and spectrum displaying. There are two methods for calculating the net area under peaks; the Covell method and non-linear fitting by the method of Levenberg and Marquardt which can fit any multiplet peak in the spectrum. The graphic display was rather fast and user friendly

Requirements for industrial x-ray equipment

International Nuclear Information System (INIS)

1987-01-01

This safety code is concerned with the protection of all individuals who may be exposed to radiation emitted by X-ray equipment operating at energies up to 1 MeV as used in industrial radiography. This code presents basic radiation safety information for the protection of personnel operating and servicing X-ray equipment and other workers and the general public in the vicinity of areas where X-ray equipment is in operation. It specifies general safety features of design, construction and functioning of X-ray equipment and facilities; describes the responsibilities of the user, operator and maintenance personnel; contains recommendations to ensure that the X-ray equipment is used and maintained in accordance with the ALARA principle; and describes a program of personnel monitoring and radiation safety surveys. ( 6 refs., 5 tabs., 4 figs.)

Synchronization Control for a Class of Discrete-Time Dynamical Networks With Packet Dropouts: A Coding-Decoding-Based Approach.

Science.gov (United States)

Wang, Licheng; Wang, Zidong; Han, Qing-Long; Wei, Guoliang

2017-09-06

The synchronization control problem is investigated for a class of discrete-time dynamical networks with packet dropouts via a coding-decoding-based approach. The data is transmitted through digital communication channels and only the sequence of finite coded signals is sent to the controller. A series of mutually independent Bernoulli distributed random variables is utilized to model the packet dropout phenomenon occurring in the transmissions of coded signals. The purpose of the addressed synchronization control problem is to design a suitable coding-decoding procedure for each node, based on which an efficient decoder-based control protocol is developed to guarantee that the closed-loop network achieves the desired synchronization performance. By applying a modified uniform quantization approach and the Kronecker product technique, criteria for ensuring the detectability of the dynamical network are established by means of the size of the coding alphabet, the coding period and the probability information of packet dropouts. Subsequently, by resorting to the input-to-state stability theory, the desired controller parameter is obtained in terms of the solutions to a certain set of inequality constraints which can be solved effectively via available software packages. Finally, two simulation examples are provided to demonstrate the effectiveness of the obtained results.

A Computer Library for Ray Tracing in Analytical Media

International Nuclear Information System (INIS)

Miqueles, Eduardo; Coimbra, Tiago A; Figueiredo, J J S de

2013-01-01

Ray tracing technique is an important tool not only for forward but also for inverse problems in Geophysics, which most of the seismic processing steps depends on. However, implementing ray tracing codes can be very time consuming. This article presents a computer library to trace rays in 2.5D media composed by stack of layers. The velocity profile inside each layer is such that the eikonal equation can be analitically solved. Therefore, the ray tracing within such profile is made fast and accurately. The great advantage of an analytical ray tracing library is the numerical precision of the quantities computed and the fast execution of the implemented codes. Although ray tracing programs already exist for a long time, for example the seis package by Cervený, with a numerical approach to compute the ray. Regardless of the fact that numerical methods can solve more general problems, the analytical ones could be part of a more sofisticated simulation process, where the ray tracing time is completely relevant. We demonstrate the feasibility of our codes using numerical examples.

Fast Computation of Pulse Height Spectra Using SGRD Code

Directory of Open Access Journals (Sweden)

Humbert Philippe

2017-01-01

Full Text Available SGRD (Spectroscopy, Gamma rays, Rapid, Deterministic code is used for fast calculation of the gamma ray spectrum produced by a spherical shielded source and measured by a detector. The photon source lines originate from the radioactive decay of the unstable isotopes. The emission rate and spectrum of these primary sources are calculated using the DARWIN code. The leakage spectrum is separated in two parts, the uncollided component is transported by ray-tracing and the scattered component is calculated using a multigroup discrete ordinates method. The pulsed height spectrum is then simulated by folding the leakage spectrum with the detector response functions which are pre-calculated using MCNP5 code for each considered detector type. An application to the simulation of the gamma spectrum produced by a natural uranium ball coated with plexiglass and measured using a NaI detector is presented.

Controlled Use of X-Ray in Dental Practice

Directory of Open Access Journals (Sweden)

Lesbia Rosa Tirado-Amado

2015-01-01

Full Text Available Abstract: Objective: To contribute in an informative and critical way to the promotion of controlled use of X-ray during dental consulting and dental care. Introduction: The practice of dentistry as a health care service requires the use of complementary tools for proper diagnosis, treatment and follow-up in patients with different clinical conditions. For that reason, the use of x-ray by dentists is common and very useful, but it involves radiation exposure to the patient and the dental professional or dental student. Although, often people do not pay attention to this exposition in regard to biological effects, because they are considered too low to generate significant biological effects. Conclusion: It is necessary to consider the risk of accumulative doses for constant exposure in dentist and dental students. Moreover, in patients, because a synergism with other radiations can occur, they can be exposed because of the attention in other areas of health. For these reasons, it is necessary to promote awareness and knowledge on basic aspects of the controlled use of X-ray in the dental care, being also aware of the need to strengthen the knowledge of the basics aspects that lead to decreased risk of biological effects from its proper use in the dental care.

Control rod drop transient analysis with the coupled parallel code pCTF-PARCSv2.7

International Nuclear Information System (INIS)

Ramos, Enrique; Roman, Jose E.; Abarca, Agustín; Miró, Rafael; Bermejo, Juan A.

2016-01-01

Highlights: • An MPI parallel version of the thermal–hydraulic subchannel code COBRA-TF has been developed. • The parallel code has been coupled to the 3D neutron diffusion code PARCSv2.7. • The new codes are validated with a control rod drop transient. - Abstract: In order to reduce the response time when simulating large reactors in detail, a parallel version of the thermal–hydraulic subchannel code COBRA-TF (CTF) has been developed using the standard Message Passing Interface (MPI). The parallelization is oriented to reactor cells, so it is best suited for models consisting of many cells. The generation of the Jacobian matrix is parallelized, in such a way that each processor is in charge of generating the data associated with a subset of cells. Also, the solution of the linear system of equations is done in parallel, using the PETSc toolkit. With the goal of creating a powerful tool to simulate the reactor core behavior during asymmetrical transients, the 3D neutron diffusion code PARCSv2.7 (PARCS) has been coupled with the parallel version of CTF (pCTF) using the Parallel Virtual Machine (PVM) technology. In order to validate the correctness of the parallel coupled code, a control rod drop transient has been simulated comparing the results with the real experimental measures acquired during an NPP real test.

Development and Application of Devices for Remote Monitoring of Gamma-Ray Contamination at RECOM Ltd

International Nuclear Information System (INIS)

Ivanov, O.P.; Stepanov, V.E.; Chesnokov, A.V.; Sudarkin, A.N.; Urutskoev, L.I.

1999-01-01

Devices for remote monitoring of gamma-ray contamination develop at RECOM Ltd. are described and typical examples of their application are show. The following devices are discussed: spectrum-sensitive collimated devices for mapping of radioactivity on contaminated surfaces- scanning collimated Gamma Locator, device for field Cs-137 contamination mapping-CORAD; devices for gamma-ray imaging computer-controlled High-Energy Radiation Visualizer (HERV) and Coded Mask Imager

Improvement of air transport data and wall transmission/reflection data in the SKYSHINE code. 2. Calculation of gamma-ray wall transmission and reflection data

Energy Technology Data Exchange (ETDEWEB)

Hayashida, Yoshihisa [Toshiba Corp., Kawasaki, Kanagawa (Japan); Ishikawa, Satoshi; Harima, Yoshiko [CRC Research Institute Inc., Tokyo (Japan); Hayashi, Katsumi; Tayama, Ryuichi [Hitachi Engineering Co. Ltd., Ibaraki (Japan); Hirayama, Hideo [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nemoto, Makoto [Visible Information Center, Tokai, Ibaraki (Japan); Sato, Osamu [Mitsubishi Research Inst., Inc., Tokyo (Japan)

2000-03-01

Transmission and reflection data of concrete and steel for 6.2 MeV gamma-ray in the SKYSHINE code have been generated using up-to-date data and method with a view to improving an accuracy of results. The transmission and reflection data depend on energy and angle. The invariant embedding method, which has merits of producing no negative angular flux and of taking small computer time, is suitable and adopted to the present purpose. Transmission data were calculated for concrete of 12 {approx} 160 cm thick and steel of 4 {approx} 39 cm thick based on the PHOTX library. Reflection data were calculated for semi-infinite slabs of concrete and steel. Consequently, smooth and consistent differential data over whole angle and energy were obtained compared with the original data calculated by discrete ordinates Sn code and Monte Carlo code. In order to use these data in the SKYSHINE code, further verification is needed using various calculation method or experimental data. (author)

Non-Protein Coding RNAs

CERN Document Server

Walter, Nils G; Batey, Robert T

2009-01-01

This book assembles chapters from experts in the Biophysics of RNA to provide a broadly accessible snapshot of the current status of this rapidly expanding field. The 2006 Nobel Prize in Physiology or Medicine was awarded to the discoverers of RNA interference, highlighting just one example of a large number of non-protein coding RNAs. Because non-protein coding RNAs outnumber protein coding genes in mammals and other higher eukaryotes, it is now thought that the complexity of organisms is correlated with the fraction of their genome that encodes non-protein coding RNAs. Essential biological processes as diverse as cell differentiation, suppression of infecting viruses and parasitic transposons, higher-level organization of eukaryotic chromosomes, and gene expression itself are found to largely be directed by non-protein coding RNAs. The biophysical study of these RNAs employs X-ray crystallography, NMR, ensemble and single molecule fluorescence spectroscopy, optical tweezers, cryo-electron microscopy, and ot...

Results from the coded aperture neutron imaging system

International Nuclear Information System (INIS)

Brubaker, Erik; Steele, John T.; Brennan, James S.; Marleau, Peter

2010-01-01

Because of their penetrating power, energetic neutrons and gamma rays (∼1 MeV) offer the best possibility of detecting highly shielded or distant special nuclear material (SNM). Of these, fast neutrons offer the greatest advantage due to their very low and well understood natural background. We are investigating a new approach to fast-neutron imaging - a coded aperture neutron imaging system (CANIS). Coded aperture neutron imaging should offer a highly efficient solution for improved detection speed, range, and sensitivity. We have demonstrated fast neutron and gamma ray imaging with several different configurations of coded masks patterns and detectors including an 'active' mask that is composed of neutron detectors. Here we describe our prototype detector and present some initial results from laboratory tests and demonstrations.

Advantages of Westinghouse BWR control rod drop accidents methodology utilizing integrated POLCA-T code

International Nuclear Information System (INIS)

Panayotov, Dobromir

2008-01-01

The paper focuses on the activities pursued by Westinghouse in the development and licensing of POLCA-T code Control Rod Drop Accident (CRDA) Methodology. The comprehensive CRDA methodology that utilizes PHOENIX4/POLCA7/POLCA-T calculation chain foresees complete cycle-specific analysis. The methodology consists of determination of candidates of control rods (CR) that could cause a significant reactivity excursion if dropped throughout the entire fuel cycle, selection of limiting initial conditions for CRDA transient simulation and transient simulation itself. The Westinghouse methodology utilizes state-of-the-art methods. Unnecessary conservatisms in the methodology have been avoided to allow the accurate prediction of margin to design bases. This is mainly achieved by using the POLCA-T code for dynamic CRDA evaluations. The code belongs to the same calculation chain that is used for core design. Thus the very same reactor, core, cycle and fuel data base is used. This allows also reducing the uncertainties of input data and parameters that determine the energy deposition in the fuel. Uncertainty treatment, very selective use of conservatisms, selection of the initial conditions for limiting case analyses, incorporation into POLCA-T code models of the licensed fuel performance code are also among the means of performing realistic CRDA transient analyses. (author)

Performance of an Error Control System with Turbo Codes in Powerline Communications

Directory of Open Access Journals (Sweden)

Balbuena-Campuzano Carlos Alberto

2014-07-01

Full Text Available This paper reports the performance of turbo codes as an error control technique in PLC (Powerline Communications data transmissions. For this system, computer simulations are used for modeling data networks based on the model classified in technical literature as indoor, and uses OFDM (Orthogonal Frequency Division Multiplexing as a modulation technique. Taking into account the channel, modulation and turbo codes, we propose a methodology to minimize the bit error rate (BER, as a function of the average received signal noise ratio (SNR.

Spatial resolution in depth-controlled surface sensitive x-ray techniques

International Nuclear Information System (INIS)

Yun, W.B.; Viccaro, P.J.

1992-01-01

The spatial resolution along the surface normal and the total depth probed are two important parameters in depth-controlled surface sensitive X-ray techniques employing grazing incidence geometry. The two parameters are analyzed in terms of optical properties (refractive indices) of the media involved and parameters of the incident X-ray beam: beam divergence, X-ray energy, and spectral bandwidth. We derive analytical expressions of the required beam divergence and spectral bandwidth of the incident beam as a function of the two parameters. Sample calculations are made for X-ray energies between 0.1 and 100 keV and for solid Be, Cu, and Au, representing material matrices consisting of low, medium, and high atomic number elements. A brief discussion on obtaining the required beam divergence and spectral bandwidth from present X-ray sources and optics is given

Diagnosing and mapping pulmonary emphysema on X-ray projection images: incremental value of grating-based X-ray dark-field imaging.

Science.gov (United States)

Meinel, Felix G; Schwab, Felix; Schleede, Simone; Bech, Martin; Herzen, Julia; Achterhold, Klaus; Auweter, Sigrid; Bamberg, Fabian; Yildirim, Ali Ö; Bohla, Alexander; Eickelberg, Oliver; Loewen, Rod; Gifford, Martin; Ruth, Ronald; Reiser, Maximilian F; Pfeiffer, Franz; Nikolaou, Konstantin

2013-01-01

To assess whether grating-based X-ray dark-field imaging can increase the sensitivity of X-ray projection images in the diagnosis of pulmonary emphysema and allow for a more accurate assessment of emphysema distribution. Lungs from three mice with pulmonary emphysema and three healthy mice were imaged ex vivo using a laser-driven compact synchrotron X-ray source. Median signal intensities of transmission (T), dark-field (V) and a combined parameter (normalized scatter) were compared between emphysema and control group. To determine the diagnostic value of each parameter in differentiating between healthy and emphysematous lung tissue, a receiver-operating-characteristic (ROC) curve analysis was performed both on a per-pixel and a per-individual basis. Parametric maps of emphysema distribution were generated using transmission, dark-field and normalized scatter signal and correlated with histopathology. Transmission values relative to water were higher for emphysematous lungs than for control lungs (1.11 vs. 1.06, pemphysema provides color-coded parametric maps, which show the best correlation with histopathology. In a murine model, the complementary information provided by X-ray transmission and dark-field images adds incremental diagnostic value in detecting pulmonary emphysema and visualizing its regional distribution as compared to conventional X-ray projections.

Transmission imaging with a coded source

International Nuclear Information System (INIS)

Stoner, W.W.; Sage, J.P.; Braun, M.; Wilson, D.T.; Barrett, H.H.

1976-01-01

The conventional approach to transmission imaging is to use a rotating anode x-ray tube, which provides the small, brilliant x-ray source needed to cast sharp images of acceptable intensity. Stationary anode sources, although inherently less brilliant, are more compatible with the use of large area anodes, and so they can be made more powerful than rotating anode sources. Spatial modulation of the source distribution provides a way to introduce detailed structure in the transmission images cast by large area sources, and this permits the recovery of high resolution images, in spite of the source diameter. The spatial modulation is deliberately chosen to optimize recovery of image structure; the modulation pattern is therefore called a ''code.'' A variety of codes may be used; the essential mathematical property is that the code possess a sharply peaked autocorrelation function, because this property permits the decoding of the raw image cast by th coded source. Random point arrays, non-redundant point arrays, and the Fresnel zone pattern are examples of suitable codes. This paper is restricted to the case of the Fresnel zone pattern code, which has the unique additional property of generating raw images analogous to Fresnel holograms. Because the spatial frequency of these raw images are extremely coarse compared with actual holograms, a photoreduction step onto a holographic plate is necessary before the decoded image may be displayed with the aid of coherent illumination

Ray Tracing for Ocean Acoustic Tomography

National Research Council Canada - National Science Library

Dushaw, Brian

1998-01-01

.... The Numerical Recipes software package provided the basis for much of this computer code. The ray equations are reviewed, and ray equations that include the effects of ocean current are derived...

Controlling X-ray beam trajectory with a flexible hollow glass fibre

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Yoshihito, E-mail: yotanaka@riken.jp [RIKEN, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan); Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337 (Japan); Nakatani, Takashi; Onitsuka, Rena [Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337 (Japan); Sawada, Kei [RIKEN, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan); Takahashi, Isao [Kwansei Gakuin University, Gakuen, Sanda, Hyogo 669-1337 (Japan)

2014-01-01

X-ray beam trajectory control has been performed by using a 1.5 m-long flexible hollow glass fibre. A two-dimensional scan of a synchrotron radiation beam was demonstrated for X-ray absorption mapping. A metre-length flexible hollow glass fibre with 20 µm-bore and 1.5 mm-cladding diameters for transporting a synchrotron X-ray beam and controlling the trajectory has been examined. The large cladding diameter maintains a moderate curvature to satisfy the shallow glancing angle of total reflection. The observed transmission efficiency was more than 20% at 12.4 keV. As a demonstration, a wide-area scan of a synchrotron radiation beam was performed to identify the elements for a fixed metal film through its absorption spectra.

Project of decree relative to the licensing and statement system of nuclear activities and to their control and bearing various modifications of the public health code and working code; Projet de decret relatif au regime d'autorisation et de declaration des activites nucleaires et a leur controle et portant diverses modifications du code de la sante publique et du code du travail

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This decree concerns the control of high level sealed radioactive sources and orphan sources. It has for objective to introduce administrative simplification, especially the radiation sources licensing and statement system, to reinforce the control measures planed by the public health code and by the employment code, to bring precision and complements in the editing of several already existing arrangements. (N.C.)

Modelling of the Rod Control System in the coupled code RELAP5-QUABOX/CUBBOX

International Nuclear Information System (INIS)

Bencik, V.; Feretic, D.; Grgic, D.

1999-01-01

There is a general agreement that for many light water reactor transient calculations, it is necessary to use a multidimensional neutron kinetics model coupled to sophisticated thermal-hydraulic models in order to obtain satisfactory results. These calculations are needed for a variety of applications for licensing safety analyses, probabilistic risk assessment, operational support, and training. At FER, Zagreb, a coupling of 3D neutronics code QUABOX/CUBBOX and system code RELAP5 was performed. In the paper the Rod Control System model in the RELAP5 part of the coupled code is presented. A first testing of the model was performed by calculation of reactor trip from full power for NPP Krsko. Results of 3D neutronics calculation obtained by coupled code QUABOX/CUBBOX were compared with point kinetics calculation performed with RELAP5 stand alone code.(author)

The FRAM code: Description and some comparisons with MGA

International Nuclear Information System (INIS)

Sampson, T.E.; Kelley, T.A.

1994-01-01

The authors describe the initial development of the FRAM gamma-ray spectrometry code for analyzing plutonium isotopics, discuss its methodology, and present some comparisons with MGA on identical items. They also present some of the features of a new Windows 3.1-based version (PC/FRAM) and describe some current measurement problems. Development of the FRAM code began in about 1985, growing out of the need at the Los Alamos TA-55 Plutonium Facility for an isotopic analysis code to give accurate results for the effective specific power of heterogeneous (Am/Pu) pyrochemical residues. These residues present a difficult challenge because the americium is present mostly in a low-Z salt matrix (AmCl 3 ) with fines and small pieces of plutonium metal dispersed throughout the salt. Plutonium gamma rays suffer different attenuation than americium gamma rays of the same energy; this makes conventional analysis with a single relative efficiency function inaccurate for Am/Pu ratios and affects the analysis in other subtle ways

Multi-rate control over AWGN channels via analog joint source-channel coding

KAUST Repository

Khina, Anatoly; Pettersson, Gustav M.; Kostina, Victoria; Hassibi, Babak

2017-01-01

We consider the problem of controlling an unstable plant over an additive white Gaussian noise (AWGN) channel with a transmit power constraint, where the signaling rate of communication is larger than the sampling rate (for generating observations and applying control inputs) of the underlying plant. Such a situation is quite common since sampling is done at a rate that captures the dynamics of the plant and which is often much lower than the rate that can be communicated. This setting offers the opportunity of improving the system performance by employing multiple channel uses to convey a single message (output plant observation or control input). Common ways of doing so are through either repeating the message, or by quantizing it to a number of bits and then transmitting a channel coded version of the bits whose length is commensurate with the number of channel uses per sampled message. We argue that such “separated source and channel coding” can be suboptimal and propose to perform joint source-channel coding. Since the block length is short we obviate the need to go to the digital domain altogether and instead consider analog joint source-channel coding. For the case where the communication signaling rate is twice the sampling rate, we employ the Archimedean bi-spiral-based Shannon-Kotel'nikov analog maps to show significant improvement in stability margins and linear-quadratic Gaussian (LQG) costs over simple schemes that employ repetition.

Multi-rate control over AWGN channels via analog joint source-channel coding

KAUST Repository

Khina, Anatoly

2017-01-05

We consider the problem of controlling an unstable plant over an additive white Gaussian noise (AWGN) channel with a transmit power constraint, where the signaling rate of communication is larger than the sampling rate (for generating observations and applying control inputs) of the underlying plant. Such a situation is quite common since sampling is done at a rate that captures the dynamics of the plant and which is often much lower than the rate that can be communicated. This setting offers the opportunity of improving the system performance by employing multiple channel uses to convey a single message (output plant observation or control input). Common ways of doing so are through either repeating the message, or by quantizing it to a number of bits and then transmitting a channel coded version of the bits whose length is commensurate with the number of channel uses per sampled message. We argue that such “separated source and channel coding” can be suboptimal and propose to perform joint source-channel coding. Since the block length is short we obviate the need to go to the digital domain altogether and instead consider analog joint source-channel coding. For the case where the communication signaling rate is twice the sampling rate, we employ the Archimedean bi-spiral-based Shannon-Kotel\\'nikov analog maps to show significant improvement in stability margins and linear-quadratic Gaussian (LQG) costs over simple schemes that employ repetition.

Calculation of gamma ray dose buildup factors in water for isotropic point, plane mono directional and line sources using MCNP code

International Nuclear Information System (INIS)

Atak, H.; Celikten, O. S.; Tombakoglu, M.

2009-01-01

Gamma ray dose buildup factors in water for isotropic point, plane mono directional and infinite/finite line sources were calculated using the MCNP code. The buildup factors are determined for gamma ray energies of 1, 2, 3 and 4 Mev and for shield thicknesses of 1, 2, 4 and 7 mean free paths. The calculated buildup factors were then fitted in the Taylor and Berger forms. For the line sources a buildup factor table was also constructed using the Sievert function and the constants in Taylor form derived in this study to compare with the Monte Carlo results. All buildup factors were compared with the tabulated data given in literature. In order to reduce the statistical errors on buildup factors, 'forced collision' option was used in the MCNP calculations.

Radiation Protection Control Area Around Baggage Control X-ray Units

International Nuclear Information System (INIS)

Prlic, I.; Radalj, Z.; Milkovic-Kraus, S.; Cerovac, Z.

2003-01-01

The importance of prompt occupational dose reporting rises when dose is received within a short-time interval or when the radiation source suffers any technical failures. Radiation exposure is to be recognized as a private/or group hazard of each person alone. Actual radiation quality of the source is to be taken into account. To optimize the radiological radiation protection Quality Control measurements of the source are done. We have developed digital dosemeters of type ALARA OD2 for external dosimetry to be used for establishing the real pattern of occupational dose delivered to the workers or/and as the (Ort) professional environmental measuring station. We are using dosemeter to define the control areas and areas of concern - point (Ort) around the source. This upgrade to legal obligatory external (film badge) dosimetry will help us to ease defining the professional stuff and working places which are actually exposed to ionising radiation of concern and for which it is necessary to provide legally required, or even additional, occupational health care programme. This means the analysis of exposure situations for specific jobs near the X-ray equipment used for baggage control in the context of carrying out a detailed study for the optimisation of radiation protection. PC data readout from device forms a real time exposure dose rate pattern that proves that any worker or other employee working nearby the baggage X-ray unit is not obliged to undergo any legal occupational monitoring (dosimetry or health) hence the total dose per year will not exceed 1 mSv under the worst working conditions. (author)

Rate Control for Network-Coded Multipath Relaying with Time-Varying Connectivity

Science.gov (United States)

2010-12-10

Armen Babikyan, Nathaniel M. Jones, Thomas H. Shake, and Andrew P. Worthen MIT Lincoln Laboratory 244 Wood Street Lexington, MA 02420 DDRE, 1777...delay U U U U SAR 11 Zach Sweet 781-981-5997 1 Rate Control for Network-Coded Multipath Relaying with Time-Varying Connectivity Brooke Shrader, Armen

High Resolution Adjustable Mirror Control for X-ray Astronomy

Science.gov (United States)

Trolier-McKinstry, Susan

We propose to build and test thin film transistor control circuitry for a new highresolution adjustable X-ray mirror technology. This control circuitry will greatly simplify the wiring scheme to address individual actuator cells. The result will be a transformative improvement for the X-ray Surveyor mission concept: mathematical models, which fit the experimental data quite well, indicate that 0.5 arcsecond imaging is feasible through this technique utilizing thin slumped glass substrates with uncorrected angular resolution of order 5-10 arcseconds. In order to correct for figures errors in a telescope with several square meters of collecting area, millions of actuator cells must be set and held at specific voltages. It is clearly not feasible to do this via millions of wires, each one connected to an actuator. Instead, we propose to develop and test thin-film technology that operates on the same principle as megapixel computer screens. We will develop the technologies needed to build thin film piezoelectric actuators, controlled by thin film ZnO transistors, on flexible polyimide films, and to connect those films to the back surfaces of X-ray mirrors on thin glass substrates without deforming the surface. These technologies represent a promising avenue of the development of mirrors for the X-Ray Surveyor mission concept. Such a telescope will make possible detailed studies of a wide variety of astrophysical sources. One example is the Warm-Hot Intergalactic Medium (WHIM), which is thought to account for a large fraction of the normal matter in the universe but which has not been detected unambiguously to date. Another is the growth of supermassive black holes in the early universe. This proposal supports NASA's goals of technical advancement of technologies suitable for future missions, and training of graduate students.

Coding in pigeons: Multiple-coding versus single-code/default strategies.

Science.gov (United States)

Pinto, Carlos; Machado, Armando

2015-05-01

To investigate the coding strategies that pigeons may use in a temporal discrimination tasks, pigeons were trained on a matching-to-sample procedure with three sample durations (2s, 6s and 18s) and two comparisons (red and green hues). One comparison was correct following 2-s samples and the other was correct following both 6-s and 18-s samples. Tests were then run to contrast the predictions of two hypotheses concerning the pigeons' coding strategies, the multiple-coding and the single-code/default. According to the multiple-coding hypothesis, three response rules are acquired, one for each sample. According to the single-code/default hypothesis, only two response rules are acquired, one for the 2-s sample and a "default" rule for any other duration. In retention interval tests, pigeons preferred the "default" key, a result predicted by the single-code/default hypothesis. In no-sample tests, pigeons preferred the key associated with the 2-s sample, a result predicted by multiple-coding. Finally, in generalization tests, when the sample duration equaled 3.5s, the geometric mean of 2s and 6s, pigeons preferred the key associated with the 6-s and 18-s samples, a result predicted by the single-code/default hypothesis. The pattern of results suggests the need for models that take into account multiple sources of stimulus control. © Society for the Experimental Analysis of Behavior.

Using Automatic Code Generation in the Attitude Control Flight Software Engineering Process

Science.gov (United States)

McComas, David; O'Donnell, James R., Jr.; Andrews, Stephen F.

1999-01-01

This paper presents an overview of the attitude control subsystem flight software development process, identifies how the process has changed due to automatic code generation, analyzes each software development phase in detail, and concludes with a summary of our lessons learned.

Results from the Coded Aperture Neutron Imaging System (CANIS)

International Nuclear Information System (INIS)

Brubaker, Erik; Steele, John T.; Brennan, James S.; Hilton, Nathan R.; Marleau, Peter

2010-01-01

Because of their penetrating power, energetic neutrons and gamma rays (∼1 MeV) offer the best possibility of detecting highly shielded or distant special nuclear material (SNM). Of these, fast neutrons offer the greatest advantage due to their very low and well understood natural background. We are investigating a new approach to fast-neutron imaging- a coded aperture neutron imaging system (CANIS). Coded aperture neutron imaging should offer a highly efficient solution for improved detection speed, range, and sensitivity. We have demonstrated fast neutron and gamma ray imaging with several different configurations of coded masks patterns and detectors including an 'active' mask that is composed of neutron detectors. Here we describe our prototype detector and present some initial results from laboratory tests and demonstrations.

User's guide for vectorized code EQUIL for calculating equilibrium chemistry on Control Data STAR-100 computer

Science.gov (United States)

Kumar, A.; Graves, R. A., Jr.; Weilmuenster, K. J.

1980-01-01

A vectorized code, EQUIL, was developed for calculating the equilibrium chemistry of a reacting gas mixture on the Control Data STAR-100 computer. The code provides species mole fractions, mass fractions, and thermodynamic and transport properties of the mixture for given temperature, pressure, and elemental mass fractions. The code is set up for the electrons H, He, C, O, N system of elements. In all, 24 chemical species are included.

Design of a microcomputer-based X-ray diffractometer controller

International Nuclear Information System (INIS)

Naval, P.C. Jr.

1988-01-01

This work describes the design of an Apple II-based X-ray diffractometer controller capable of acquiring and analyzing X-ray powder diffraction data. The controller's interrupt-drivers hardware includes an on-based scaler for counting X-ray pulses, a closed-loop stepper motor driver for Philips PW 1050 Vertical Goniometer, and circuits for present data collection and safety. ACQUIRE - data acquisition program for the controller coordinates its various devices so that it can perform sample scanning in any of the following modes: continuous, present tome or present count scanning. This program watches over the scanning process and will try to correct any error it detects. Any fault monitored is logged on disk. The collected diffraction data are stored on disk together with its data acquisition parameters and may be transported to another computer. Data analysis is done by ANALYZE a program that operates on the output file generated by ACQUIRE. Its 15 single-keystroke commands permit panning and zooming of the sample's diffractogram, data smoothing, data peak search, peak report generation, and digital plotting. Data smoothing uses a third-degree Savitzky-Golay Convoluting Filter of user defined width. For peak detection, the peak search algorithm examines the diffractograms second derivative for any Gaussian resemblance and checks the peaks' area for statistical significance. The hard copy plot is available from any on-line digital plotted supporting EPSON's Mode D Plotter Commands. (Author). 15 refs. Appendixes p. 85-163

Computational techniques in gamma-ray skyshine analysis

International Nuclear Information System (INIS)

George, D.L.

1988-12-01

Two computer codes were developed to analyze gamma-ray skyshine, the scattering of gamma photons by air molecules. A review of previous gamma-ray skyshine studies discusses several Monte Carlo codes, programs using a single-scatter model, and the MicroSkyshine program for microcomputers. A benchmark gamma-ray skyshine experiment performed at Kansas State University is also described. A single-scatter numerical model was presented which traces photons from the source to their first scatter, then applies a buildup factor along a direct path from the scattering point to a detector. The FORTRAN code SKY, developed with this model before the present study, was modified to use Gauss quadrature, recent photon attenuation data and a more accurate buildup approximation. The resulting code, SILOGP, computes response from a point photon source on the axis of a silo, with and without concrete shielding over the opening. Another program, WALLGP, was developed using the same model to compute response from a point gamma source behind a perfectly absorbing wall, with and without shielding overhead. 29 refs., 48 figs., 13 tabs

ARES: automated response function code. Users manual. [HPGAM and LSQVM

Energy Technology Data Exchange (ETDEWEB)

Maung, T.; Reynolds, G.M.

1981-06-01

This ARES user's manual provides detailed instructions for a general understanding of the Automated Response Function Code and gives step by step instructions for using the complete code package on a HP-1000 system. This code is designed to calculate response functions of NaI gamma-ray detectors, with cylindrical or rectangular geometries.

Project of decree relative to the licensing and statement system of nuclear activities and to their control and bearing various modifications of the public health code and working code

International Nuclear Information System (INIS)

2005-01-01

This decree concerns the control of high level sealed radioactive sources and orphan sources. It has for objective to introduce administrative simplification, especially the radiation sources licensing and statement system, to reinforce the control measures planed by the public health code and by the employment code, to bring precision and complements in the editing of several already existing arrangements. (N.C.)

Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground Based Computation and Control Systems and Human Health and Safety

Science.gov (United States)

Atwell, William; Koontz, Steve; Normand, Eugene

2012-01-01

In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).

Quality control procedure for dental x-ray film processing

International Nuclear Information System (INIS)

Tingey, D.R.C.

1983-08-01

Methods of obtaining the optimum processing from dental films are discussed. A method of quality control of developing conditions for dental x-ray films has been developed. It is relatively easy to maintain and is sufficiently accurate for practical purposes

Ways with Data: Understanding Coding as Writing

Science.gov (United States)

Lindgren, Chris

2017-01-01

In this dissertation, I report findings from an exploratory case-study about Ray, a web developer, who works on a data-driven news team that finds and tells compelling stories with large sets of data. I implicate this case of Ray's coding on a data team in a writing studies epistemology, which is guided by the following question: "What might…

Cosmic ray effect on the X-ray Trigger Telescope of UFFO/Lomonosov using YSO scintillation crystal array in space

DEFF Research Database (Denmark)

Kim, M. B.; Jeong, S.; Jeong, H. M.

2017-01-01

UFFO Burst Alert and Trigger telescope (UBAT) is the X-ray trigger telescope of UFFO/Lomonosov to localize X-ray source with coded mask method and X-ray detector. Its X-ray detector is made up of 36 8×8 pixels Yttrium OxyorthoSilicate (Y2SiO5:Ce, YSO) scintillation crystal arrays and 36 64-channe...

New challenges in ray tracing simulations of X-ray optics

International Nuclear Information System (INIS)

Río, M Sánchez del

2013-01-01

The construction of new synchrotron sources and the refurbishment and upgrade of existing ones has boosted in the last years the interest in X-ray optics simulations for beamline design and optimization. In the last years we conducted a full renewal of the well established SHADOW ray tracing code, ending with a modular version SHADOW3 interfaced to multiple programming languages (C, C++, IDL, Python). Some of the new features of SHADOW3 are presented. From the physics point of view, SHADOW3 has been upgraded for dealing with lens systems. X-ray partial coherence applications demand an extension of traditional ray tracing methods into a hybrid ray-tracing wave-optics approach. The software development is essential for fulfilling the requests of the ESRF Upgrade Programme, and some examples of calculations are also presented.

The symbol coding language for the BUTs processor of in-core reactor control systems

International Nuclear Information System (INIS)

Vorob'ev, D.M.; Golovanov, M.N.; Levin, G.L.; Parfenova, T.K.; Filatov, V.P.

1978-01-01

A symbolic coding language is described; it has been developed for automation of making up programs for in-core control systems. The systems use the ideology of the CAMAC-VECTOR system and include the BUTs-20 processor. The symbolic coding language has been developed as a programming language of the ASSEMBLER type. Operators of instructions and pseudo-instructions, the rules of reading in the text of the source program, and operator record formats are considered

Code of practice for the design and safe operation of non-medical irradiation facilities (1988)

International Nuclear Information System (INIS)

1988-01-01

This Code establishes requirements for the design and operation of irradiation facilities which use X-rays, electrons or gamma radiation for non-medical purposes such as the sterilisation of therapeutic goods. These requirements aim to ensure that exposure of workers and members of the public to ionizing and non-ionizing radiation as well as to noxious gases and radioactive contamination of the environment and facilities are controlled through the design of engineering safety features, approved administrative controls and appropriate radiation monitoring [fr

Quality control test solutions for diagnostic radiology, nuclear medicine and health physics with PTW equipment

International Nuclear Information System (INIS)

Froescher, Olga

2007-01-01

Complete test of publication follows. In 1922 PTW-Freiburg was founded to produce and market a revolutionary new electromechanical component for measuring very small electrical charges. Today PTW is the specialist and one of the global market leaders for manufacturing and supplying high-quality products in diagnostic radiology, nuclear medicine, radiation therapy and health physics. The quality control of X-ray images is influenced by a number of parameters. To maintain a consistent performance of X-ray installations, quality checks have to be conducted regularly. PTW offers a variety of diagnostic test tools for different X-ray devices, and therefore to reduce patient exposure and costs for X-ray departments. PTW's 'Code of Practice' defines in an easy and compact way how to perform quality control measurements on different diagnostic X-ray installations. The necessary equipment for measuring main parameters as well as acceptable limits are mentioned accordingly. The 'Code of Practice' bases on actual standards.

Controller routines for the DECsystem-10 with application to a tandem-mirror plasma code

International Nuclear Information System (INIS)

Faul, D.R.; Devoto, R.S.

1979-01-01

FORTRAN-callable subroutines have been written to enable controller--controllee interaction on the LLL DECsystem-10. These subroutines have been used to construct a controller (XTCTMR) for a tandem-mirror physics code (CTCTMR). A description of the subroutines and their use is presented. Also, sample results are given

Computer-supported quality control in X-ray diagnosis

International Nuclear Information System (INIS)

Maier, W.; Klotz, E.

1989-01-01

Quality control of X-ray facilities in radiological departments of large hospitals is possible only if the instrumentation used for measurements is interfaced to a computer. The central computer helps to organize the measurements as well as analyse and record the results. It can also be connected to a densitometer and camera for evaluating radiographs of test devices. Other quality control tests are supported by a mobile station with equipment for non-invasive dosimetry measurements. Experience with a computer-supported system in quality control of film and film processing is described and the evaluation methods of ANSI and the German industrial standard DIN are compared. The disadvantage of these methods is the exclusion of film quality parameters, which can make processing control almost worthless. (author)

Nuclear Physics Meets the Sources of the Ultra-High Energy Cosmic Rays.

Science.gov (United States)

Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

2017-07-07

The determination of the injection composition of cosmic ray nuclei within astrophysical sources requires sufficiently accurate descriptions of the source physics and the propagation - apart from controlling astrophysical uncertainties. We therefore study the implications of nuclear data and models for cosmic ray astrophysics, which involves the photo-disintegration of nuclei up to iron in astrophysical environments. We demonstrate that the impact of nuclear model uncertainties is potentially larger in environments with non-thermal radiation fields than in the cosmic microwave background. We also study the impact of nuclear models on the nuclear cascade in a gamma-ray burst radiation field, simulated at a level of complexity comparable to the most precise cosmic ray propagation code. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions in cosmic ray sources and propagation.

Achievable Performance of Zero-Delay Variable-Rate Coding in Rate-Constrained Networked Control Systems with Channel Delay

DEFF Research Database (Denmark)

Barforooshan, Mohsen; Østergaard, Jan; Stavrou, Fotios

2017-01-01

This paper presents an upper bound on the minimum data rate required to achieve a prescribed closed-loop performance level in networked control systems (NCSs). The considered feedback loop includes a linear time-invariant (LTI) plant with single measurement output and single control input. Moreover......, in this NCS, a causal but otherwise unconstrained feedback system carries out zero-delay variable-rate coding, and control. Between the encoder and decoder, data is exchanged over a rate-limited noiseless digital channel with a known constant time delay. Here we propose a linear source-coding scheme...

Automation of an X-ray diffractometer using a manually preset control system

International Nuclear Information System (INIS)

Berry, T.; Prentice, P.C.

1978-11-01

The measurements of lattice parameters of beta silicon carbide nuclear reactor temperature monitors at Dounreay were formerly carried out using an X-ray diffractometer connected to a simple step scan control system with an analysis time of 8 hours per specimen. A system is described whereby the step scan throughout of the X-ray diffractometer is increased by using an automatic sample charger and additional control electronics, allowing round-the-clock analysis. The original system which used Harwell 2000 series electronic units has been expanded to include an AERE designed goniometer control unit, a Philips sample changer with control unit, and a Honeywell chart recorder. The integrated circuit logic used, interconnections of modules, and operating instructions are given in appendices. (UK)

Manually operated coded switch

International Nuclear Information System (INIS)

Barnette, J.H.

1978-01-01

The disclosure related to a manually operated recodable coded switch in which a code may be inserted, tried and used to actuate a lever controlling an external device. After attempting a code, the switch's code wheels must be returned to their zero positions before another try is made

Nuclear data libraries for Tripoli-3.5 code; Bibliotheques de donnees nucleaires pour le code tripoli-3.5

Energy Technology Data Exchange (ETDEWEB)

Vergnaud, Th

2001-07-01

The TRIPOLI-3 code uses multigroup nuclear data libraries generated using the NJOY-THEMIS suite of modules: for neutrons, they are produced from the ENDF/B-VI evaluations and cover the range between 20 MeV and 10{sup -5} eV, either in 315 groups and for one temperature, or in 3209 groups and for five temperatures; for gamma-rays, they are from JEF2 and are processed in groups between 14 MeV and keV. The probability tables used for the neutron transport calculations have been derived from the ENDF/B-VI evaluations using the CALENDF code. Cross sections for gamma production by neutron interaction (fission, capture or inelastic scattering) have been derived from ENDF/B-VI in 315 neutron groups and 75 gamma groups. The code also uses two response function libraries: for neutrons; based on several sources, in particular the dosimetry libraries IRDF/85 and IRDF/90; for gamma-rays it is based on the JEF2 evaluation and contains the kerma factors for all the elements and cross sections for all interactions. (author)

Quality control assessment of diagnostic x-ray facilities in Ghana

International Nuclear Information System (INIS)

Amoako, J.K.; Charles, D.F.; Oppong-Adu, C.; Schandorf, C.

2009-01-01

Twenty-three X-ray machines located at 20 different hospitals in Ghana were assessed for quality assurance and control. The radiographic parameters evaluated were tube voltage and current, tube output consistency variation with kilovoltage (kV) and current-time (mAs) factor, exposure time accuracy and beam quality as measured by half-value layer. The photographic parameters assessed were type of films, level of film fogging, film speed, contrast index and film processing temperature. Twenty two of the machines were ∼ 99 % output consistency with standard kVp and mAs. Twelve of the machines had output linearity deviation of less than the acceptable 5 %, while 22 machines were within the accepted kVp deviation of 5 %. The film processing temperature at most hospitals exceeded the required level, due to the absence of air conditioners in the darkrooms. The darkroom quality control at all the facilities was very high. Fogging of films was minimal as indicated by the Base + Fog value of 0.3, speed index of film was ∼ 1.65 and contrast index was comparable to the acceptable value of 1.5. The level of timer accuracy was greater than 95 % for all the X-ray machines with the exception of one. The general quality control status of all the X-ray machines and darkrooms assessed were acceptable and within the quality assurance standards. (au)

Spatially coded backscatter radiography

International Nuclear Information System (INIS)

Thangavelu, S.; Hussein, E.M.A.

2007-01-01

Conventional radiography requires access to two opposite sides of an object, which makes it unsuitable for the inspection of extended and/or thick structures (airframes, bridges, floors etc.). Backscatter imaging can overcome this problem, but the indications obtained are difficult to interpret. This paper applies the coded aperture technique to gamma-ray backscatter-radiography in order to enhance the detectability of flaws. This spatial coding method involves the positioning of a mask with closed and open holes to selectively permit or block the passage of radiation. The obtained coded-aperture indications are then mathematically decoded to detect the presence of anomalies. Indications obtained from Monte Carlo calculations were utilized in this work to simulate radiation scattering measurements. These simulated measurements were used to investigate the applicability of this technique to the detection of flaws by backscatter radiography

Design of scanning motion control system for high-energy X-ray industrial CT

International Nuclear Information System (INIS)

Duan Liming

2008-01-01

A scanning motion control system was developed for the high-energy X-ray industrial computerized tomography (CT). The system consists of an industrial control computer, a counter card, a control card, servo drivers, servo motors, working platforms, gratings and control software. Based on windows driver model(WDM) mode, the composition of the driver pro- gram for the system was studied. Took the motor control card as an example, the method to develop the driver program was researched, and the intercourse process between the device driver program and the user-program was analyzed. The real-time control of the system was implemented using the WDM driver. The real-time performance and reliability of the system can satisfy the requirement of high-energy X-ray industrial CT. (authors)

Computer code FIT

International Nuclear Information System (INIS)

Rohmann, D.; Koehler, T.

1987-02-01

This is a description of the computer code FIT, written in FORTRAN-77 for a PDP 11/34. FIT is an interactive program to decude position, width and intensity of lines of X-ray spectra (max. length of 4K channels). The lines (max. 30 lines per fit) may have Gauss- or Voigt-profile, as well as exponential tails. Spectrum and fit can be displayed on a Tektronix terminal. (orig.) [de

Physical-technical quality control for medical x-ray apparatus

International Nuclear Information System (INIS)

Aalbers, A.H.L.

1989-01-01

The technical aspects of quality control in medial x-ray diagnostics are discussed. It is recommended to hurry, also in the Netherlands, on the basis of already existing starting-up's abroad, with drawing up quality standards and judgement criteria. (author). 6 refs.; 2 figs.; 1 tab

Dental x-rays and the risk of thyroid cancer: A case-control study

International Nuclear Information System (INIS)

Memon, Anjum; Godward, Sara; Williams, Dillwyn; Siddique, Iqbal; Al-Saleh, Khalid

2010-01-01

The thyroid gland is highly susceptible to radiation carcinogenesis and exposure to high-dose ionising radiation is the only established cause of thyroid cancer. Dental radiography, a common source of low-dose diagnostic radiation exposure in the general population, is often overlooked as a radiation hazard to the gland and may be associated with the risk of thyroid cancer. An increased risk of thyroid cancer has been reported in dentists, dental assistants, and x-ray workers; and exposure to dental x-rays has been associated with an increased risk of meningiomas and salivary tumours. Methods. To examine whether exposure to dental x-rays was associated with the risk of thyroid cancer, we conducted a population-based case-control interview study among 313 patients with thyroid cancer and a similar number of individually matched (year of birth ± three years, gender, nationality, district of residence) control subjects in Kuwait. Results. Conditional logistic regression analysis, adjusted for other upper-body x-rays, showed that exposure to dental x-rays was significantly associated with an increased risk of thyroid cancer (odds ratio = 2.1, 95% confidence interval: 1.4, 3.1) (p=0.001) with a dose-response pattern (p for trend <0.0001). The association did not vary appreciably by age, gender, nationality, level of education, or parity. Discussion. These findings, based on self-report by cases/controls, provide some support to the hypothesis that exposure to dental x-rays, particularly multiple exposures, may be associated with an increased risk of thyroid cancer; and warrant further study in settings where historical dental x-ray records may be available.

Dental x-rays and the risk of thyroid cancer: A case-control study

Energy Technology Data Exchange (ETDEWEB)

Memon, Anjum (Div. of Primary Care and Public Health, Brighton and Sussex Medical School (United Kingdom)), E-mail: a.memon@bsms.ac.uk; Godward, Sara (Dept. of Public Health and Primary Care, Univ. of Cambridge (United Kingdom)); Williams, Dillwyn (Thyroid Carcinogenesis Research Group, Strangeways Research Laboratories, Univ. of Cambridge (United Kingdom)); Siddique, Iqbal (Dept. of Medicine, Faculty of Medicine, Kuwait Univ. (Kuwait)); Al-Saleh, Khalid (Kuwait Cancer Control Centre, Ministry of Health (Kuwait))

2010-05-15

The thyroid gland is highly susceptible to radiation carcinogenesis and exposure to high-dose ionising radiation is the only established cause of thyroid cancer. Dental radiography, a common source of low-dose diagnostic radiation exposure in the general population, is often overlooked as a radiation hazard to the gland and may be associated with the risk of thyroid cancer. An increased risk of thyroid cancer has been reported in dentists, dental assistants, and x-ray workers; and exposure to dental x-rays has been associated with an increased risk of meningiomas and salivary tumours. Methods. To examine whether exposure to dental x-rays was associated with the risk of thyroid cancer, we conducted a population-based case-control interview study among 313 patients with thyroid cancer and a similar number of individually matched (year of birth +- three years, gender, nationality, district of residence) control subjects in Kuwait. Results. Conditional logistic regression analysis, adjusted for other upper-body x-rays, showed that exposure to dental x-rays was significantly associated with an increased risk of thyroid cancer (odds ratio = 2.1, 95% confidence interval: 1.4, 3.1) (p=0.001) with a dose-response pattern (p for trend <0.0001). The association did not vary appreciably by age, gender, nationality, level of education, or parity. Discussion. These findings, based on self-report by cases/controls, provide some support to the hypothesis that exposure to dental x-rays, particularly multiple exposures, may be associated with an increased risk of thyroid cancer; and warrant further study in settings where historical dental x-ray records may be available.

Imaging X-Ray Polarimetry Explorer Mission Attitude Determination and Control Concept

Science.gov (United States)

Bladt, Jeff; Deininger, William D.; Kalinowski, William C.; Boysen, Mary; Bygott, Kyle; Guy, Larry; Pentz, Christina; Seckar, Chris; Valdez, John; Wedmore, Jeffrey;

MED101: a laser-plasma simulation code. User guide

International Nuclear Information System (INIS)

Rodgers, P.A.; Rose, S.J.; Rogoyski, A.M.

1989-12-01

Complete details for running the 1-D laser-plasma simulation code MED101 are given including: an explanation of the input parameters, instructions for running on the Rutherford Appleton Laboratory IBM, Atlas Centre Cray X-MP and DEC VAX, and information on three new graphics packages. The code, based on the existing MEDUSA code, is capable of simulating a wide range of laser-produced plasma experiments including the calculation of X-ray laser gain. (author)

Clinical application of radiation dosimetry on X-ray radiotherapy

International Nuclear Information System (INIS)

Mizutani, Takeo

1995-01-01

In the case of radiotherapy, it is important to give proper dose for a tumor, to be treated with the objective of therapy, and to evaluate the dose, considering dose for other organs at risk to a sufficient extent. To provide an exposure dose at the target volume of tumor parts, it should be required to get a good understanding of the correct dosimetric method and also to apply this to clinical application in practice. All over the country, so as not to produce any difference in the given dose, 'A practical code for the dosimetry of high energy X-rays in radiotherapy' was issued by the Japanese Associations of radiological physicists in 1972. In 1986, it was revised. At about 85% of therapeutic facilities in the country, radiation engineers perform dose measurements and controls. Therefore, I have explained the process of measurement and dose calculation, with the main objective directed at the engineers in charge of the radiotherapy so as to easily radiation dosimetry of X-ray with dosemeters and phantom used at each facility according to the 'practical code'. (author)

Modeling IrisCode and its variants as convex polyhedral cones and its security implications.

Science.gov (United States)

Kong, Adams Wai-Kin

2013-03-01

IrisCode, developed by Daugman, in 1993, is the most influential iris recognition algorithm. A thorough understanding of IrisCode is essential, because over 100 million persons have been enrolled by this algorithm and many biometric personal identification and template protection methods have been developed based on IrisCode. This paper indicates that a template produced by IrisCode or its variants is a convex polyhedral cone in a hyperspace. Its central ray, being a rough representation of the original biometric signal, can be computed by a simple algorithm, which can often be implemented in one Matlab command line. The central ray is an expected ray and also an optimal ray of an objective function on a group of distributions. This algorithm is derived from geometric properties of a convex polyhedral cone but does not rely on any prior knowledge (e.g., iris images). The experimental results show that biometric templates, including iris and palmprint templates, produced by different recognition methods can be matched through the central rays in their convex polyhedral cones and that templates protected by a method extended from IrisCode can be broken into. These experimental results indicate that, without a thorough security analysis, convex polyhedral cone templates cannot be assumed secure. Additionally, the simplicity of the algorithm implies that even junior hackers without knowledge of advanced image processing and biometric databases can still break into protected templates and reveal relationships among templates produced by different recognition methods.

pyXSIM: Synthetic X-ray observations generator

Science.gov (United States)

ZuHone, John A.; Hallman, Eric. J.

2016-08-01

pyXSIM simulates X-ray observations from astrophysical sources. X-rays probe the high-energy universe, from hot galaxy clusters to compact objects such as neutron stars and black holes and many interesting sources in between. pyXSIM generates synthetic X-ray observations of these sources from a wide variety of models, whether from grid-based simulation codes such as FLASH (ascl:1010.082), Enzo (ascl:1010.072), and Athena (ascl:1010.014), to particle-based codes such as Gadget (ascl:0003.001) and AREPO, and even from datasets that have been created “by hand”, such as from NumPy arrays. pyXSIM can also manipulate the synthetic observations it produces in various ways and export the simulated X-ray events to other software packages to simulate the end products of specific X-ray observatories. pyXSIM is an implementation of the PHOX (ascl:1112.004) algorithm and was initially the photon_simulator analysis module in yt (ascl:1011.022); it is dependent on yt.

Upgrade of the JET gamma-ray cameras

International Nuclear Information System (INIS)

Soare, S.; Curuia, M.; Anghel, M.; Constantin, M.; David, E.; Craciunescu, T.; Falie, D.; Pantea, A.; Tiseanu, I.; Kiptily, V.; Prior, P.; Edlington, T.; Griph, S.; Krivchenkov, Y.; Loughlin, M.; Popovichev, S.; Riccardo, V; Syme, B.; Thompson, V.; Lengar, I.; Murari, A.; Bonheure, G.; Le Guern, F.

2007-01-01

Full text: The JET gamma-ray camera diagnostics have already provided valuable information on the gamma-ray imaging of fast ion in JET plasmas. The applicability of gamma-ray imaging to high performance deuterium and deuterium-tritium JET discharges is strongly dependent on the fulfilment of rather strict requirements for the characterisation of the neutron and gamma-ray radiation fields. These requirements have to be satisfied within very stringent boundary conditions for the design, such as the requirement of minimum impact on the co-existing neutron camera diagnostics. The JET Gamma-Ray Cameras (GRC) upgrade project deals with these issues with particular emphasis on the design of appropriate neutron/gamma-ray filters ('neutron attenuators'). Several design versions have been developed and evaluated for the JET GRC neutron attenuators at the conceptual design level. The main design parameter was the neutron attenuation factor. The two design solutions, that have been finally chosen and developed at the level of scheme design, consist of: a) one quasi-crescent shaped neutron attenuator (for the horizontal camera) and b) two quasi-trapezoid shaped neutron attenuators (for the vertical one). The second design solution has different attenuation lengths: a short version, to be used together with the horizontal attenuator for deuterium discharges, and a long version to be used for high performance deuterium and DT discharges. Various neutron-attenuating materials have been considered (lithium hydride with natural isotopic composition and 6 Li enriched, light and heavy water, polyethylene). Pure light water was finally chosen as the attenuating material for the JET gamma-ray cameras. The neutron attenuators will be steered in and out of the detector line-of-sight by means of an electro-pneumatic steering and control system. The MCNP code was used for neutron and gamma ray transport in order to evaluate the effect of the neutron attenuators on the neutron field of the

JEM-X: The X-ray monitor on INTEGRAL

DEFF Research Database (Denmark)

Lund, Niels; Budtz-Jørgensen, Carl; Westergaard, Niels Jørgen Stenfeldt

1999-01-01

and identification of gamma ray sources as well as in the analysis and scientific interpretation of the combined X-ray and gamma ray data. JEM-X is a coded aperture X-ray telescope consisting of two identical detectors. Each detector has a sensitive area of 500 cm(2), and views the sky (6.6 deg FOV, FWHM) through...

A Brain Computer Interface for Robust Wheelchair Control Application Based on Pseudorandom Code Modulated Visual Evoked Potential

DEFF Research Database (Denmark)

Mohebbi, Ali; Engelsholm, Signe K.D.; Puthusserypady, Sadasivan

2015-01-01

In this pilot study, a novel and minimalistic Brain Computer Interface (BCI) based wheelchair control application was developed. The system was based on pseudorandom code modulated Visual Evoked Potentials (c-VEPs). The visual stimuli in the scheme were generated based on the Gold code...

Applications of FLUKA Monte Carlo code for nuclear and accelerator physics

CERN Document Server

Battistoni, Giuseppe; Brugger, Markus; Campanella, Mauro; Carboni, Massimo; Empl, Anton; Fasso, Alberto; Gadioli, Ettore; Cerutti, Francesco; Ferrari, Alfredo; Ferrari, Anna; Lantz, Matthias; Mairani, Andrea; Margiotta, M; Morone, Christina; Muraro, Silvia; Parodi, Katerina; Patera, Vincenzo; Pelliccioni, Maurizio; Pinsky, Lawrence; Ranft, Johannes; Roesler, Stefan; Rollet, Sofia; Sala, Paola R; Santana, Mario; Sarchiapone, Lucia; Sioli, Maximiliano; Smirnov, George; Sommerer, Florian; Theis, Christian; Trovati, Stefania; Villari, R; Vincke, Heinz; Vincke, Helmut; Vlachoudis, Vasilis; Vollaire, Joachim; Zapp, Neil

2011-01-01

FLUKA is a general purpose Monte Carlo code capable of handling all radiation components from thermal energies (for neutrons) or 1keV (for all other particles) to cosmic ray energies and can be applied in many different fields. Presently the code is maintained on Linux. The validity of the physical models implemented in FLUKA has been benchmarked against a variety of experimental data over a wide energy range, from accelerator data to cosmic ray showers in the Earth atmosphere. FLUKA is widely used for studies related both to basic research and to applications in particle accelerators, radiation protection and dosimetry, including the specific issue of radiation damage in space missions, radiobiology (including radiotherapy) and cosmic ray calculations. After a short description of the main features that make FLUKA valuable for these topics, the present paper summarizes some of the recent applications of the FLUKA Monte Carlo code in the nuclear as well high energy physics. In particular it addresses such top...

X-ray diagnostic device with an X-ray image amplifier, whose output image is fed into a movie camera, as well as a brightness control

Energy Technology Data Exchange (ETDEWEB)

Lutz, H

1978-02-09

The X-ray relief appearing behind a patient is immediately or with amplificating foils converted into a latent film image. By using a X-ray image amplifier the X-ray relief is then converted into a reduced and brighter optical image and fed into a photographic or movie camera and shot. To avoid a reduction in the image quality by quantum noise and a too large patient and physician dose a brightness control is provided for the X-ray diagnostic device. The control only dims as far as a brightness per image is produced that avoids quantum noise. On the other side it opens more by strongly beam absorbing patients or a smaller imaging ratio of the X-ray image amplifier to obtain a desired irradiation.

BERMUDA-1DG: a one-dimensional photon transport code

International Nuclear Information System (INIS)

Suzuki, Tomoo; Hasegawa, Akira; Nakashima, Hiroshi; Kaneko, Kunio.

1984-10-01

A one-dimensional photon transport code BERMUDA-1DG has been developed for spherical and infinite slab geometries. The purpose of development is to equip the function of gamma rays calculation for the BERMUDA code system, which was developed by 1983 only for neutron transport calculation as a preliminary version. A group constants library has been prepared for 30 nuclides, and it now consists of the 36-group total cross sections and secondary gamma ray yields by the 120-group neutron flux. For the Compton scattering, group-angle transfer matrices are accurately obtained by integrating the Klein-Nishina formula taking into account the energy and scattering angle correlation. The pair production cross sections are now calculated in the code from atomic number and midenergy of each group. To obtain angular flux distribution, the transport equation is solved in the same way as in case of neutron, using the direct integration method in a multigroup model. Both of an independent gamma ray source problem and a neutron-gamma source problem are possible to be solved. This report is written as a user's manual with a brief description of the calculational method. (author)

Controlled area for mobile medical X-ray equipment

Energy Technology Data Exchange (ETDEWEB)

Menzel, B; Taschner, P; Koenig, W [Staatliches Amt fuer Atomsicherheit und Strahlenschutz, Berlin (German Democratic Republic); Fuehr, K P; Kucharz, R [Rostock Univ. (German Democratic Republic). Radiologische Klinik

1976-10-01

On the basis of dose rate measurements the radiation protection situation during operation of mobile X-ray machines is described. According to these results, the controlled area has been definitely fixed by the National Board of Nuclear Safety and Radiation Protection with respect to the following fields of application: stomatology, mobile radiography of patients confined to bed as well as performing radiological examinations in the operating theatre.

High-resolution imaging gamma-ray spectroscopy with externally segmented germanium detectors

Science.gov (United States)

Callas, J. L.; Mahoney, W. A.; Varnell, L. S.; Wheaton, W. A.

1993-01-01

Externally segmented germanium detectors promise a breakthrough in gamma-ray imaging capabilities while retaining the superb energy resolution of germanium spectrometers. An angular resolution of 0.2 deg becomes practical by combining position-sensitive germanium detectors having a segment thickness of a few millimeters with a one-dimensional coded aperture located about a meter from the detectors. Correspondingly higher angular resolutions are possible with larger separations between the detectors and the coded aperture. Two-dimensional images can be obtained by rotating the instrument. Although the basic concept is similar to optical or X-ray coded-aperture imaging techniques, several complicating effects arise because of the penetrating nature of gamma rays. The complications include partial transmission through the coded aperture elements, Compton scattering in the germanium detectors, and high background count rates. Extensive electron-photon Monte Carlo modeling of a realistic detector/coded-aperture/collimator system has been performed. Results show that these complicating effects can be characterized and accounted for with no significant loss in instrument sensitivity.

Development of a new EMP code at LANL

Science.gov (United States)

Colman, J. J.; Roussel-Dupré, R. A.; Symbalisty, E. M.; Triplett, L. A.; Travis, B. J.

2006-05-01

A new code for modeling the generation of an electromagnetic pulse (EMP) by a nuclear explosion in the atmosphere is being developed. The source of the EMP is the Compton current produced by the prompt radiation (γ-rays, X-rays, and neutrons) of the detonation. As a first step in building a multi- dimensional EMP code we have written three kinetic codes, Plume, Swarm, and Rad. Plume models the transport of energetic electrons in air. The Plume code solves the relativistic Fokker-Planck equation over a specified energy range that can include ~ 3 keV to 50 MeV and computes the resulting electron distribution function at each cell in a two dimensional spatial grid. The energetic electrons are allowed to transport, scatter, and experience Coulombic drag. Swarm models the transport of lower energy electrons in air, spanning 0.005 eV to 30 keV. The swarm code performs a full 2-D solution to the Boltzmann equation for electrons in the presence of an applied electric field. Over this energy range the relevant processes to be tracked are elastic scattering, three body attachment, two body attachment, rotational excitation, vibrational excitation, electronic excitation, and ionization. All of these occur due to collisions between the electrons and neutral bodies in air. The Rad code solves the full radiation transfer equation in the energy range of 1 keV to 100 MeV. It includes effects of photo-absorption, Compton scattering, and pair-production. All of these codes employ a spherical coordinate system in momentum space and a cylindrical coordinate system in configuration space. The "z" axis of the momentum and configuration spaces is assumed to be parallel and we are currently also assuming complete spatial symmetry around the "z" axis. Benchmarking for each of these codes will be discussed as well as the way forward towards an integrated modern EMP code.

The FLUKA code for space applications Recent developments

CERN Document Server

Andersen, V; Battistoni, G; Campanella, M; Carboni, M; Cerutti, F; Empl, A; Fassò, A; Ferrari, A; Gadioli, E; Garzelli, M V; Lee, K; Ottolenghi, A; Pelliccioni, M; Pinsky, L S; Ranft, J; Roesler, S; Sala, P R; Wilson, T L

2004-01-01

The FLUKA Monte Carlo transport code is widely used for fundamental research, radioprotection and dosimetry, hybrid nuclear energy system and cosmic ray calculations. The validity of its physical models has been benchmarked against a variety of experimental data over a wide range of energies, ranging from accelerator data to cosmic ray showers in the earth atmosphere. The code is presently undergoing several developments in order to better fit the needs of space applications. The generation of particle spectra according to up-to- date cosmic ray data as well as the effect of the solar and geomagnetic modulation have been implemented and already successfully applied to a variety of problems. The implementation of suitable models for heavy ion nuclear interactions has reached an operational stage. At medium/high energy FLUKA is using the DPMJET model. The major task of incorporating heavy ion interactions from a few GeV/n down to the threshold for inelastic collisions is also progressing and promising results h...

Dose Distribution Calculation Using MCNPX Code in the Gamma-ray Irradiation Cell

International Nuclear Information System (INIS)

Kim, Yong Ho

1991-02-01

60 Co-gamma irradiators have long been used for foods sterilization, plant mutation and development of radio-protective agents, radio-sensitizers and other purposes. The Applied Radiological Science Research Institute of Cheju National University has a multipurpose gamma irradiation facility loaded with a MDS Nordin standard 60 Co source (C188), of which the initial activity was 400 TBq (10,800 Ci) on February 19, 2004. This panoramic gamma irradiator is designed to irradiate in all directions various samples such as plants, cultured cells and mice to administer given radiation doses. In order to give accurate doses to irradiation samples, appropriate methods of evaluating, both by calculation and measurement, the radiation doses delivered to the samples should be set up. Computational models have been developed to evaluate the radiation dose distributions inside the irradiation chamber and the radiation doses delivered to typical biolological samples which are frequently irradiated in the facility. The computational models are based on using the MCNPX code. The horizontal and vertical dose distributions has been calculated inside the irradiation chamber and compared the calculated results with measured data obtained with radiation dosimeters to verify the computational models. The radiation dosimeters employed are a Famer's type ion chamber and MOSFET dosimeters. Radiation doses were calculated by computational models, which were delivered to cultured cell samples contained in test tubes and to a mouse fixed in a irradiation cage, and compared the calculated results with the measured data. The computation models are also tested to see if they can accurately simulate the case where a thick lead shield is placed between the source and detector. Three tally options of the MCNPX code, F4, F5 and F6, are alternately used to see which option produces optimum results. The computation models are also used to calculate gamma ray energy spectra of a BGO scintillator at

Safety assessment and quality control of medical x-ray facilities in some hospitals in Ghana

International Nuclear Information System (INIS)

Darko, E.O.; Charles, D.F.

1998-01-01

Safety assessment and quality control measurements of diagnostic x-ray installations were carried out in five hospitals in Ghana. The study was focused on the siting, design and construction of the buildings housing the x-ray units, assessment of safety systems and devices and measurements of the technical performance, and film processing conditions. The location, inadequacies in the design/construction, unavailability of relevant safety systems and devices, violation of basic safety principles and poor performance of some of the x-ray facilities indicate the need to improve quality control programmes, safety culture and enforcement of regulatory standards in diagnostic x-ray examinations in Ghana. (author). 8 refs., 11 tabs., 8 figs

Accidental over-exposure from dental X-ray equipment

Energy Technology Data Exchange (ETDEWEB)

Phillips, B G [National Radiological Protection Board, Harwell (UK)

1976-07-01

A description is given of an unusual dental X-ray procedure which resulted in accidental over-exposure both to the dentist and to several of his patients when a short-circuit was present in newly-installed equipment. The short-circuit by-passed the exposure control and energized the tube for certain orientations of the X-ray tube. The dentist left the patients, who wore protective aprons, to initiate the exposure themselves, using the control button. Although the warning lights were on, the dentist was not present in the room during the exposure, and the over-exposures were only detected when the developed X-ray films were found to be completely blackened. A reconstruction of the procedure enabled estimates to be made of the dose equivalents to the dentist's body and to the skin of the head, the eyes and the gonads of the patients. The dentist had overlooked several of basic principles recommended in the Code of Practice for the Protection of Persons against Ionizing Radiations from Medical and Dental Use (1972). It is pointed out that incidents involving failure of dental equipment (usually the timer mechanism) are not infrequent.

Testing efficiency transfer codes for equivalence

International Nuclear Information System (INIS)

Vidmar, T.; Celik, N.; Cornejo Diaz, N.; Dlabac, A.; Ewa, I.O.B.; Carrazana Gonzalez, J.A.; Hult, M.; Jovanovic, S.; Lepy, M.-C.; Mihaljevic, N.; Sima, O.; Tzika, F.; Jurado Vargas, M.; Vasilopoulou, T.; Vidmar, G.

2010-01-01

Four general Monte Carlo codes (GEANT3, PENELOPE, MCNP and EGS4) and five dedicated packages for efficiency determination in gamma-ray spectrometry (ANGLE, DETEFF, GESPECOR, ETNA and EFFTRAN) were checked for equivalence by applying them to the calculation of efficiency transfer (ET) factors for a set of well-defined sample parameters, detector parameters and energies typically encountered in environmental radioactivity measurements. The differences between the results of the different codes never exceeded a few percent and were lower than 2% in the majority of cases.

MatLab script to C code converter for embedded processors of FLASH LLRF control system

Science.gov (United States)

Bujnowski, K.; Siemionczyk, A.; Pucyk, P.; Szewiński, J.; Pożniak, K. T.; Romaniuk, R. S.

2008-01-01

The low level RF control system (LLRF) of FEL serves for stabilization of the electromagnetic (EM) field in the superconducting niobium, resonant, microwave cavities and for controlling high power (MW) klystron. LLRF system of FLASH accelerator bases on FPGA technology and embedded microprocessors. Basic and auxiliary functions of the systems are listed as well as used algorithms for superconductive cavity parameters identification. These algorithms were prepared originally in Matlab. The main part of the paper presents implementation of the cavity parameters identification algorithm in a PowerPC processor embedded in the FPGA circuit VirtexIIPro. A construction of a very compact Matlab script converter to C code was presented, referred to as M2C. The application is designed specifically for embedded systems of very confined resources. The generated code is optimized for the weight. The code should be transferable between different hardware platforms. The converter generates a code for Linux and for stand-alone applications. Functional structure of the program was described and the way it is acting. FLEX and BIZON tools were used for construction of the converter. The paper concludes with an example of the M2C application to convert a complex identification algorithm for superconductive cavities in FLASH laser.

A study on enforcement effects of radiation safety control regulations for diagnostic X-ray equipment

International Nuclear Information System (INIS)

Sung, Mo IL; Park, Myeong Hwan; Kwon, Duk Moon; Lee, Joon IL

1999-01-01

The purposes of this study are to analyze the realities after enforcements of safety control regulations for diagnostic X-ray equipment and to suggest means for an improvement of low radiation safety control. A questionnaire survey for medical radiologic technologists was carried out to determine enforcement effects of the safety control regulations. The results of analysis from the survey are as follows. That is, most of he respondents realized the importance of the radiation safety control system, but about a half of them revealed that regulations were not well observed in accordance with their purposes. Only 43.9 percent of the respondents took an active part in quality control of radiation. And responsibility, sex, age, and knowledge for safety control were important indicators for observations of the regulations. Training for the safety control regulations are needed to ensure safety control and proper usage of diagnostic X-ray equipment. And management of organizations using diagnostic X-ray equipment have to understand and stress the importance of radiation safety control system. (author)

Benchmark of the non-parametric Bayesian deconvolution method implemented in the SINBAD code for X/γ rays spectra processing

Energy Technology Data Exchange (ETDEWEB)

Rohée, E. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette (France); Coulon, R., E-mail: romain.coulon@cea.fr [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette (France); Carrel, F. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette (France); Dautremer, T.; Barat, E.; Montagu, T. [CEA, LIST, Laboratoire de Modélisation et Simulation des Systèmes, F-91191 Gif-sur-Yvette (France); Normand, S. [CEA, DAM, Le Ponant, DPN/STXN, F-75015 Paris (France); Jammes, C. [CEA, DEN, Cadarache, DER/SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France)

2016-11-11

Radionuclide identification and quantification are a serious concern for many applications as for in situ monitoring at nuclear facilities, laboratory analysis, special nuclear materials detection, environmental monitoring, and waste measurements. High resolution gamma-ray spectrometry based on high purity germanium diode detectors is the best solution available for isotopic identification. Over the last decades, methods have been developed to improve gamma spectra analysis. However, some difficulties remain in the analysis when full energy peaks are folded together with high ratio between their amplitudes, and when the Compton background is much larger compared to the signal of a single peak. In this context, this study deals with the comparison between a conventional analysis based on “iterative peak fitting deconvolution” method and a “nonparametric Bayesian deconvolution” approach developed by the CEA LIST and implemented into the SINBAD code. The iterative peak fit deconvolution is used in this study as a reference method largely validated by industrial standards to unfold complex spectra from HPGe detectors. Complex cases of spectra are studied from IAEA benchmark protocol tests and with measured spectra. The SINBAD code shows promising deconvolution capabilities compared to the conventional method without any expert parameter fine tuning.

X-ray diagnostic device with an X-ray image amplifier, whose output image is fed into a movie camera, as well as a brightness control

International Nuclear Information System (INIS)

Lutz, H.

1978-01-01

The X-ray relief appearing behind a patient is immediately or with amplificating foils converted into a latent film image. By using a X-ray image amplifier the X-ray relief is then converted into a reduced and brighter optical image and fed into a photographic or movie camera and shot. To avoid a reduction in the image quality by quantum noise and a too large patient and physician dose a brightness control is provided for the X-ray diagnostic device. The control only dims as far as a brightness per image is produced that avoids quantum noise. On the other side it opens more by strongly beam absorbing patients or a smaller imaging ratio of the X-ray image amplifier to obtain a desired irradiation. (DG) [de

Qualitative and quantitative validation of the SINBAD code on complex HPGe gamma-ray spectra

Energy Technology Data Exchange (ETDEWEB)

Rohee, E.; Coulon, R.; Normand, S.; Carrel, F. [CEA, LIST, Laboratoire Capteurs et Architectures electroniques, F-91191 Gif-sur-Yvette, (France); Dautremer, T.; Barat, E.; Montagu, T. [CEA, LIST, Laboratoire Modelisation, Simulation et Systemes, F-91191 Gif-sur-Yvette, (France); Jammes, C. [CEA/DEN/SPEx/LDCI, Centre de Cadarache, F-13109 Saint-Paul-lez-Durance, (France)

2015-07-01

Radionuclides identification and quantification is a serious concern for many applications as safety or security of nuclear power plant or fuel cycle facility, CBRN risk identification, environmental radioprotection and waste measurements. High resolution gamma-ray spectrometry based on HPGe detectors is a performing solution for all these topics. During last decades, a great number of software has been developed to improve gamma spectra analysis. However, some difficulties remain in the analysis when photoelectric peaks are folded together with a high ratio between theirs amplitudes, when the Compton background is much larger compared to the signal of a single peak and when spectra are composed of a great number of peaks. This study deals with the comparison between conventional methods in radionuclides identification and quantification and the code called SINBAD ('Spectrometrie par Inference Non parametrique Bayesienne Deconvolutive'). For many years, SINBAD has been developed by CEA LIST for unfolding complex spectra from HPGe detectors. Contrary to conventional methods using fitting procedures, SINBAD uses a probabilistic approach with Bayesian inference to describe spectrum data. This conventional fitting method founded for example in Genie 2000 is compared with the nonparametric SINBAD approach regarding some key figures of merit as the peak centroid evaluation (identification) and peak surface evaluation (quantification). Unfriendly cases are studied for nuclides detection with closed gamma-rays energies and high photoelectric peak intensity differences. Tests are performed with spectra from the International Atomic Energy Agency (IAEA) for gamma spectra analysis software benchmark and with spectra acquired at the laboratory. Results show that SINBAD and Genie 2000 performances are quite similar with sometimes best results for SINBAD with the important difference that to achieve same performances the nonparametric method is user-friendly compared

Quantum control using genetic algorithms in quantum communication: superdense coding

International Nuclear Information System (INIS)

Domínguez-Serna, Francisco; Rojas, Fernando

2015-01-01

We present a physical example model of how Quantum Control with genetic algorithms is applied to implement the quantum superdense code protocol. We studied a model consisting of two quantum dots with an electron with spin, including spin-orbit interaction. The electron and the spin get hybridized with the site acquiring two degrees of freedom, spin and charge. The system has tunneling and site energies as time dependent control parameters that are optimized by means of genetic algorithms to prepare a hybrid Bell-like state used as a transmission channel. This state is transformed to obtain any state of the four Bell basis as required by superdense protocol to transmit two bits of classical information. The control process protocol is equivalent to implement one of the quantum gates in the charge subsystem. Fidelities larger than 99.5% are achieved for the hybrid entangled state preparation and the superdense operations. (paper)

Governance codes: facts or fictions? a study of governance codes in colombia1,2

Directory of Open Access Journals (Sweden)

Julián Benavides Franco

2010-10-01

Full Text Available This article studies the effects on accounting performance and financing decisions of Colombian firms after issuing a corporate governance code. We assemble a database of Colombian issuers and test the hypotheses of improved performance and higher leverage after issuing a code. The results show that the firms’ return on assets after the code introduction improves in excess of 1%; the effect is amplified by the code quality. Additionally, the firms leverage increased, in excess of 5%, when the code quality was factored into the analysis. These results suggest that controlling parties commitment to self restrain, by reducing their private benefits and/or the expropriation of non controlling parties, through the code introduction, is indeed an effective measure and that the financial markets agree, increasing the supply of funds to the firms.

Cable control and take-up mechanisms and x-ray scanning apparatus incorporating such mechanisms

International Nuclear Information System (INIS)

Braden, A.B.; Lekan, J.J.; Taylor, S.K.; Richey, J.B.

1977-01-01

In this patent, an invention for cable control and take-up mechanisms for elongated, flexible cables is described. Such cables are used in X-ray scanner apparatus to provide power, electronic signals and fluids. A detailed design and description is given of the cable harness, control and take-up mechanism that would be used in conjunction with an X-ray scanner. As a result of this invention, the cables are prevented from becoming prematurely worn or entangled in the X-ray apparatus during the rotational and translational movements necessary in tomographic examinations. This invention is also applicable to other types of apparatus and environments where a number of different positions is required and where it is necessary to control the take-up of elongated, flexible, cable-like members. (U.K.)

Joint Machine Learning and Game Theory for Rate Control in High Efficiency Video Coding.

Science.gov (United States)

Gao, Wei; Kwong, Sam; Jia, Yuheng

2017-08-25

In this paper, a joint machine learning and game theory modeling (MLGT) framework is proposed for inter frame coding tree unit (CTU) level bit allocation and rate control (RC) optimization in High Efficiency Video Coding (HEVC). First, a support vector machine (SVM) based multi-classification scheme is proposed to improve the prediction accuracy of CTU-level Rate-Distortion (R-D) model. The legacy "chicken-and-egg" dilemma in video coding is proposed to be overcome by the learning-based R-D model. Second, a mixed R-D model based cooperative bargaining game theory is proposed for bit allocation optimization, where the convexity of the mixed R-D model based utility function is proved, and Nash bargaining solution (NBS) is achieved by the proposed iterative solution search method. The minimum utility is adjusted by the reference coding distortion and frame-level Quantization parameter (QP) change. Lastly, intra frame QP and inter frame adaptive bit ratios are adjusted to make inter frames have more bit resources to maintain smooth quality and bit consumption in the bargaining game optimization. Experimental results demonstrate that the proposed MLGT based RC method can achieve much better R-D performances, quality smoothness, bit rate accuracy, buffer control results and subjective visual quality than the other state-of-the-art one-pass RC methods, and the achieved R-D performances are very close to the performance limits from the FixedQP method.

Does a colour-coded blood pressure diary improve blood pressure control for patients in general practice: the CoCo trial.

Science.gov (United States)

Steurer-Stey, Claudia; Zoller, Marco; Chmiel Moshinsky, Corinne; Senn, Oliver; Rosemann, Thomas

2010-04-14

Insufficient blood pressure control is a frequent problem despite the existence of effective treatment. Insufficient adherence to self-monitoring as well as to therapy is a common reason. Blood pressure self-measurement at home (Home Blood Pressure Measurement, HBPM) has positive effects on treatment adherence and is helpful in achieving the target blood pressure. Only a few studies have investigated whether adherence to HBPM can be improved through simple measures resulting also in better blood pressure control. Improvement of self-monitoring and improved blood pressure control by using a new colour-coded blood pressure diary. Change in systolic and/or diastolic blood pressure 6 months after using the new colour-coded blood pressure diary.Secondary outcome: Adherence to blood pressure self-measurement (number of measurements/entries). Randomised controlled study. 138 adult patients in primary care with uncontrolled hypertension despite therapy. The control group uses a conventional blood pressure diary; the intervention group uses the new colour-coded blood pressure diary (green, yellow, red according a traffic light system). EXPECTED RESULTS/CONCLUSION: The visual separation and entries in three colour-coded areas reflecting risk (green: blood pressure in the target range 140/>90 mmHg, red: blood pressure in danger zone > 180 mmHg/>110 mmHg) lead to better self-monitoring compared with the conventional (non-colour-coded) blood pressure booklet. The colour-coded, visualised information supports improved perception (awareness and interpretation) of blood pressure and triggers correct behaviour, in the means of improved adherence to the recommended treatment as well as better communication between patients and doctors resulting in improved blood pressure control. ClinicalTrials.gov ID NCT01013467.

Introduction of thermal-hydraulic analysis code and system analysis code for HTGR

International Nuclear Information System (INIS)

Tanaka, Mitsuhiro; Izaki, Makoto; Koike, Hiroyuki; Tokumitsu, Masashi

1984-01-01

Kawasaki Heavy Industries Ltd. has advanced the development and systematization of analysis codes, aiming at lining up the analysis codes for heat transferring flow and control characteristics, taking up HTGR plants as the main object. In order to make the model of flow when shock waves propagate to heating tubes, SALE-3D which can analyze a complex system was developed, therefore, it is reported in this paper. Concerning the analysis code for control characteristics, the method of sensitivity analysis in a topological space including an example of application is reported. The flow analysis code SALE-3D is that for analyzing the flow of compressible viscous fluid in a three-dimensional system over the velocity range from incompressibility limit to supersonic velocity. The fundamental equations and fundamental algorithm of the SALE-3D, the calculation of cell volume, the plotting of perspective drawings and the analysis of the three-dimensional behavior of shock waves propagating in heating tubes after their rupture accident are described. The method of sensitivity analysis was added to the analysis code for control characteristics in a topological space, and blow-down phenomena was analyzed by its application. (Kako, I.)

Test of Effective Solid Angle code for the efficiency calculation of volume source

Energy Technology Data Exchange (ETDEWEB)

Kang, M. Y.; Kim, J. H.; Choi, H. D. [Seoul National Univ., Seoul (Korea, Republic of); Sun, G. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

It is hard to determine a full energy (FE) absorption peak efficiency curve for an arbitrary volume source by experiment. That's why the simulation and semi-empirical methods have been preferred so far, and many works have progressed in various ways. Moens et al. determined the concept of effective solid angle by considering an attenuation effect of γ-rays in source, media and detector. This concept is based on a semi-empirical method. An Effective Solid Angle code (ESA code) has been developed for years by the Applied Nuclear Physics Group in Seoul National University. ESA code converts an experimental FE efficiency curve determined by using a standard point source to that for a volume source. To test the performance of ESA Code, we measured the point standard sources and voluminous certified reference material (CRM) sources of γ-ray, and compared with efficiency curves obtained in this study. 200∼1500 KeV energy region is fitted well. NIST X-ray mass attenuation coefficient data is used currently to check for the effect of linear attenuation only. We will use the interaction cross-section data obtained from XCOM code to check the each contributing factor like photoelectric effect, incoherent scattering and coherent scattering in the future. In order to minimize the calculation time and code simplification, optimization of algorithm is needed.

DISP1 code

International Nuclear Information System (INIS)

Vokac, P.

1999-12-01

DISP1 code is a simple tool for assessment of the dispersion of the fission product cloud escaping from a nuclear power plant after an accident. The code makes it possible to tentatively check the feasibility of calculations by more complex PSA3 codes and/or codes for real-time dispersion calculations. The number of input parameters is reasonably low and the user interface is simple enough to allow a rapid processing of sensitivity analyses. All input data entered through the user interface are stored in the text format. Implementation of dispersion model corrections taken from the ARCON96 code enables the DISP1 code to be employed for assessment of the radiation hazard within the NPP area, in the control room for instance. (P.A.)

Novel x-ray imaging methods at the Nova Laser Facility

International Nuclear Information System (INIS)

Ress, D.; DaSilva, L.B.; London, R.A.; Trebes, J.E.; Lerche, R.A.; Bradley, D.K.

1994-01-01

We are pursuing several novel x-ray imaging schemes to measure plasma parameters in inertial-confinement fusion experiments. This paper will review two quite successful approaches, the soft x-ray moire deflectometer, and the annular (ring) coded-aperture microscope. The deflectometer is the newer diagnostic, and this paper will concentrate on this topic. We will describe the operating principles of moire deflectometry, give the motivations for soft x-ray probing, describe the physical apparatus in detail, and present some sample images and results. The ring coded-aperture microscope has been described previously, so here we will only briefly review the principle of the instrument. We will concentrate on the signal-to-noise ratio calculations that motivate the use of annular coded apertures, and describe recent work to predict and measure the resolution of the instrument

UNICOS CPC6: Automated Code Generation for Process Control Applications

CERN Document Server

Fernandez Adiego, B; Prieto Barreiro, I

2011-01-01

The Continuous Process Control package (CPC) is one of the components of the CERN Unified Industrial Control System framework (UNICOS) [1]. As a part of this framework, UNICOS-CPC provides a well defined library of device types, amethodology and a set of tools to design and implement industrial control applications. The new CPC version uses the software factory UNICOS Application Builder (UAB) [2] to develop CPC applications. The CPC component is composed of several platform oriented plugins PLCs and SCADA) describing the structure and the format of the generated code. It uses a resource package where both, the library of device types and the generated file syntax, are defined. The UAB core is the generic part of this software, it discovers and calls dynamically the different plug-ins and provides the required common services. In this paper the UNICOS CPC6 package is introduced. It is composed of several plug-ins: the Instance generator and the Logic generator for both, Siemens and Schneider PLCs, the SCADA g...

Container for waste, identification code reading device thereof, method and system for controlling waste by using them

International Nuclear Information System (INIS)

Kikuchi, Takashi; Yoshida, Tomiji; Omote, Tatsuyuki.

1991-01-01

In the conventional method of controlling waste containers by labels attached thereto, the data relevant to wastes contained in the waste containers are limited. Further, if the label should be peeled off, there is a possibility that the wastes therein can no more be identified. Then, in the present invention, an identification plate is previously attached, to which mechanically readable codes or visually readable letters or numerical figures are written. Then, the identification codes can be read in a remote control manner at high speed and high reliability and the waste containers can be managed only by the identification codes of the containers. Further, the identification codes on the container are made so as to be free from aging degradation, thereby enabling to manage waste containers for long time storage. With such a constitution, since data can be inputted from an input terminal and a great amount of data such as concerning the source of wastes can be managed collectively on a software, the data can be managed easily. (T.M.)

Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B.W.; Firestone, Richard B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

2010-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF has been used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy an is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We use CASINO, a version of DICEBOX that is modified for this purpose. This can be used to simulate the neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modelling of unknown assemblies.

Contributions of Sensory Coding and Attentional Control to Individual Differences in Performance in Spatial Auditory Selective Attention Tasks.

Science.gov (United States)

Dai, Lengshi; Shinn-Cunningham, Barbara G

2016-01-01

Listeners with normal hearing thresholds (NHTs) differ in their ability to steer attention to whatever sound source is important. This ability depends on top-down executive control, which modulates the sensory representation of sound in the cortex. Yet, this sensory representation also depends on the coding fidelity of the peripheral auditory system. Both of these factors may thus contribute to the individual differences in performance. We designed a selective auditory attention paradigm in which we could simultaneously measure envelope following responses (EFRs, reflecting peripheral coding), onset event-related potentials (ERPs) from the scalp (reflecting cortical responses to sound) and behavioral scores. We performed two experiments that varied stimulus conditions to alter the degree to which performance might be limited due to fine stimulus details vs. due to control of attentional focus. Consistent with past work, in both experiments we find that attention strongly modulates cortical ERPs. Importantly, in Experiment I, where coding fidelity limits the task, individual behavioral performance correlates with subcortical coding strength (derived by computing how the EFR is degraded for fully masked tones compared to partially masked tones); however, in this experiment, the effects of attention on cortical ERPs were unrelated to individual subject performance. In contrast, in Experiment II, where sensory cues for segregation are robust (and thus less of a limiting factor on task performance), inter-subject behavioral differences correlate with subcortical coding strength. In addition, after factoring out the influence of subcortical coding strength, behavioral differences are also correlated with the strength of attentional modulation of ERPs. These results support the hypothesis that behavioral abilities amongst listeners with NHTs can arise due to both subcortical coding differences and differences in attentional control, depending on stimulus characteristics

Contributions of sensory coding and attentional control to individual differences in performance in spatial auditory selective attention tasks

Directory of Open Access Journals (Sweden)

Lengshi Dai

2016-10-01

Full Text Available Listeners with normal hearing thresholds differ in their ability to steer attention to whatever sound source is important. This ability depends on top-down executive control, which modulates the sensory representation of sound in cortex. Yet, this sensory representation also depends on the coding fidelity of the peripheral auditory system. Both of these factors may thus contribute to the individual differences in performance. We designed a selective auditory attention paradigm in which we could simultaneously measure envelope following responses (EFRs, reflecting peripheral coding, onset event-related potentials from the scalp (ERPs, reflecting cortical responses to sound, and behavioral scores. We performed two experiments that varied stimulus conditions to alter the degree to which performance might be limited due to fine stimulus details vs. due to control of attentional focus. Consistent with past work, in both experiments we find that attention strongly modulates cortical ERPs. Importantly, in Experiment I, where coding fidelity limits the task, individual behavioral performance correlates with subcortical coding strength (derived by computing how the EFR is degraded for fully masked tones compared to partially masked tones; however, in this experiment, the effects of attention on cortical ERPs were unrelated to individual subject performance. In contrast, in Experiment II, where sensory cues for segregation are robust (and thus less of a limiting factor on task performance, inter-subject behavioral differences correlate with subcortical coding strength. In addition, after factoring out the influence of subcortical coding strength, behavioral differences are also correlated with the strength of attentional modulation of ERPs. These results support the hypothesis that behavioral abilities amongst listeners with normal hearing thresholds can arise due to both subcortical coding differences and differences in attentional control, depending on

Does a colour-coded blood pressure diary improve blood pressure control for patients in general practice: The CoCo trial

Directory of Open Access Journals (Sweden)

Senn Oliver

2010-04-01

Full Text Available Abstract Background Insufficient blood pressure control is a frequent problem despite the existence of effective treatment. Insufficient adherence to self-monitoring as well as to therapy is a common reason. Blood pressure self-measurement at home (Home Blood Pressure Measurement, HBPM has positive effects on treatment adherence and is helpful in achieving the target blood pressure. Only a few studies have investigated whether adherence to HBPM can be improved through simple measures resulting also in better blood pressure control. Objective Improvement of self-monitoring and improved blood pressure control by using a new colour-coded blood pressure diary. Outcome Primary outcome: Change in systolic and/or diastolic blood pressure 6 months after using the new colour-coded blood pressure diary. Secondary outcome: Adherence to blood pressure self-measurement (number of measurements/entries. Methods/Design Randomised controlled study. Population: 138 adult patients in primary care with uncontrolled hypertension despite therapy. The control group uses a conventional blood pressure diary; the intervention group uses the new colour-coded blood pressure diary (green, yellow, red according a traffic light system. Expected results/conclusion The visual separation and entries in three colour-coded areas reflecting risk (green: blood pressure in the target range ≤ 140/≤ 90 mmHg, yellow: blood pressure >140/>90 mmHg, red: blood pressure in danger zone > 180 mmHg/>110 mmHg lead to better self-monitoring compared with the conventional (non-colour-coded blood pressure booklet. The colour-coded, visualised information supports improved perception (awareness and interpretation of blood pressure and triggers correct behaviour, in the means of improved adherence to the recommended treatment as well as better communication between patients and doctors resulting in improved blood pressure control. Trial registration ClinicalTrials.gov ID NCT01013467

Applications for X-ray detectors in astrophysics

International Nuclear Information System (INIS)

Remillard, R.A.

2003-01-01

Full text: Position-sensitive X-Ray detectors continue to playa central role in high-energy astrophysics. The current science goals are reviewed with emphasis on requirements in terms of camera performance. Wide-field imaging techniques, including coded mask cameras, are an essential part of space programs because of the transient nature of high-priority targets, e.g. eruptions from black-hole binaries and cosmic explosions such as gamma ray bursts. Pointing X-ray telescopes are being planned with a wide range of photon energies and with collection designs that include both mirrors and coded masks. Requirements for high spectral resolution and high time resolution are driven by diverse types of X-ray sources such as msec pulsars, quasars with emission-line profiles shaped by general relativity, and X-ray binaries that exhibit quasi-periodic oscillations in the range of 40-1300 Hz. Many laboratories and universities are involved in space-qualification of new detector technologies, e.g. CZT cameras, X-ray calorimeters, new types of CCDs, and GEM detectors. Even X-ray interferometry is on the horizon of NASA's science roadmap. The difficulties in advancing new technologies for space science applications require careful coordinations between industry and science groups in order to solve science problems while minimizing risk

Optimization of parameters affecting LSM performance as diffractors of x rays: Final technical report, 13 May 1986-31 October 1987

International Nuclear Information System (INIS)

Knight, L.V.

1987-10-01

Our efforts during this contract period were directed toward a deeper understanding of several important issues related to multilayer x-ray mirrors. The results have important practical applications. The topics studied included: Basic Stress-Strain-Curvature Theory for Thin Silicon Wafers with Oxide and Nitride Films; this theory and accompanying experimental verification could form the basis for development of a code that will be able to predict the final figure of a silicon substrate that has been etched and treated with oxide or nitride films; this code will allow the design and fabrication of sophisticated curved multilayers; we have applied our theoretical understanding of multilayers to the design of multilayer x-ray optics; Multilayer X-ray Data Analysis Codes; these codes allow the massaging and display of x-ray multilayer characterization data in a wide variety of graphical ways; the code is user friendly; simulation of multilayers behavior in a high x-ray flux environment; this code combines an x-ray input code (BUCKL) with a 1-D hydrodynamic code (Chart-D) and our own iterative multilayer design code to determine the reflectivity of multilayers as a function of time when the multilayer is in a region of high x-ray flux; BUCKL and Chart-D are from Sandia Labs.; and we have completed the first series of experimental measurements of multilayer reflectivity while subjected to a pulse of intense x-ray flux; the experiments were done with the Phoenix laser at LLNL; the results are included. 48 refs., 29 figs

Nuclear data libraries for Tripoli-3.5 code

International Nuclear Information System (INIS)

Vergnaud, Th.

2001-01-01

The TRIPOLI-3 code uses multigroup nuclear data libraries generated using the NJOY-THEMIS suite of modules: for neutrons, they are produced from the ENDF/B-VI evaluations and cover the range between 20 MeV and 10 -5 eV, either in 315 groups and for one temperature, or in 3209 groups and for five temperatures; for gamma-rays, they are from JEF2 and are processed in groups between 14 MeV and keV. The probability tables used for the neutron transport calculations have been derived from the ENDF/B-VI evaluations using the CALENDF code. Cross sections for gamma production by neutron interaction (fission, capture or inelastic scattering) have been derived from ENDF/B-VI in 315 neutron groups and 75 gamma groups. The code also uses two response function libraries: for neutrons; based on several sources, in particular the dosimetry libraries IRDF/85 and IRDF/90; for gamma-rays it is based on the JEF2 evaluation and contains the kerma factors for all the elements and cross sections for all interactions. (author)

Coded aperture imaging system for nuclear fuel motion detection

International Nuclear Information System (INIS)

Stalker, K.T.; Kelly, J.G.

1980-01-01

A Coded Aperature Imaging System (CAIS) has been developed at Sandia National Laboratories to image the motion of nuclear fuel rods undergoing tests simulating accident conditions within a liquid metal fast breeder reactor. The tests require that the motion of the test fuel be monitored while it is immersed in a liquid sodium coolant precluding the use of normal optical means of imaging. However, using the fission gamma rays emitted by the fuel itself and coded aperture techniques, images with 1.5 mm radial and 5 mm axial resolution have been attained. Using an electro-optical detection system coupled to a high speed motion picture camera a time resolution of one millisecond can be achieved. This paper will discuss the application of coded aperture imaging to the problem, including the design of the one-dimensional Fresnel zone plate apertures used and the special problems arising from the reactor environment and use of high energy gamma ray photons to form the coded image. Also to be discussed will be the reconstruction techniques employed and the effect of various noise sources on system performance. Finally, some experimental results obtained using the system will be presented

X-RAYS SEPARATOR: FORWARD STEP IN TECHNOLOGY OF OPTICAL SEPARATION

Directory of Open Access Journals (Sweden)

N. N. Potrakhov

2017-01-01

Full Text Available Presently the X-ray separation is used not only for research program, but it is also elaborated and applied for different sectors of economy. The seeds as biological objects that possess the complicated microstructure are very difficult to be exanimated by x-ray technology. The application of x-rays and further elaboration of optical  separators, principle  of action, basic specifications, way of their use and their efficiency was shown in the article. The x-ray separator may distinguish all hidden seed defects as it was described by a programmer, where owing to the use of the optical separating block in visual range it is possible to add some more details as a shape, brightness and a color of object surface being exanimated. The elaboration of such separation equipment is scientifically hard work requiring time and expenses. Last year researchers of ‘LETI’ developed the working model of industrial x-ray separator for examination of grains and nuts in different crops. This model was made on the basis of photoseparator F-5 manufactured at OAO ‘Voronezhselmash’. The instrument state and its mechanism operation are highlighted on monitor. In the regime of processing (separation and examination of each controlled batch, the passport is produced with  following  information on identification  code,  time of material receiving, time of test passed, number of grains or seeds tested. The code of receiver of material is given to each of established characteristics when working the regime of separation, determination of number of objects with characteristics tested and number of unidentified objects. The application of x-ray separators constructed on the basis of photoseparator F-5 enables to carry out the complex estimation on seed quality and separation in only instrument with the development of electronic protocol with many characteristics.

Experimental benchmark of non-local-thermodynamic-equilibrium plasma atomic physics codes; Validation experimentale des codes de physique atomique des plasmas hors equilibre thermodynamique local

Energy Technology Data Exchange (ETDEWEB)

Nagels-Silvert, V

2004-09-15

The main purpose of this thesis is to get experimental data for the testing and validation of atomic physics codes dealing with non-local-thermodynamical-equilibrium plasmas. The first part is dedicated to the spectroscopic study of xenon and krypton plasmas that have been produced by a nanosecond laser pulse interacting with a gas jet. A Thomson scattering diagnostic has allowed us to measure independently plasma parameters such as electron temperature, electron density and the average ionisation state. We have obtained time integrated spectra in the range between 5 and 10 angstroms. We have identified about one hundred xenon rays between 8.6 and 9.6 angstroms via the use of the Relac code. We have discovered unknown rays for the krypton between 5.2 and 7.5 angstroms. In a second experiment we have extended the wavelength range to the X UV domain. The Averroes/Transpec code has been tested in the ranges from 9 to 15 angstroms and from 10 to 130 angstroms, the first range has been well reproduced while the second range requires a more complex data analysis. The second part is dedicated to the spectroscopic study of aluminium, selenium and samarium plasmas in femtosecond operating rate. We have designed an interferometry diagnostic in the frequency domain that has allowed us to measure the expanding speed of the target's backside. Via the use of an adequate isothermal model this parameter has led us to know the plasma electron temperature. Spectra and emission times of various rays from the aluminium and selenium plasmas have been computed satisfactorily with the Averroes/Transpec code coupled with Film and Multif hydrodynamical codes. (A.C.)

Experimental benchmark of non-local-thermodynamic-equilibrium plasma atomic physics codes; Validation experimentale des codes de physique atomique des plasmas hors equilibre thermodynamique local

Energy Technology Data Exchange (ETDEWEB)

Nagels-Silvert, V

2004-09-15

The main purpose of this thesis is to get experimental data for the testing and validation of atomic physics codes dealing with non-local-thermodynamical-equilibrium plasmas. The first part is dedicated to the spectroscopic study of xenon and krypton plasmas that have been produced by a nanosecond laser pulse interacting with a gas jet. A Thomson scattering diagnostic has allowed us to measure independently plasma parameters such as electron temperature, electron density and the average ionisation state. We have obtained time integrated spectra in the range between 5 and 10 angstroms. We have identified about one hundred xenon rays between 8.6 and 9.6 angstroms via the use of the Relac code. We have discovered unknown rays for the krypton between 5.2 and 7.5 angstroms. In a second experiment we have extended the wavelength range to the X UV domain. The Averroes/Transpec code has been tested in the ranges from 9 to 15 angstroms and from 10 to 130 angstroms, the first range has been well reproduced while the second range requires a more complex data analysis. The second part is dedicated to the spectroscopic study of aluminium, selenium and samarium plasmas in femtosecond operating rate. We have designed an interferometry diagnostic in the frequency domain that has allowed us to measure the expanding speed of the target's backside. Via the use of an adequate isothermal model this parameter has led us to know the plasma electron temperature. Spectra and emission times of various rays from the aluminium and selenium plasmas have been computed satisfactorily with the Averroes/Transpec code coupled with Film and Multif hydrodynamical codes. (A.C.)

A Novel Optical Morse Code-Based Electronic Lock Using the Ambient Light Sensor and Fuzzy Controller

Directory of Open Access Journals (Sweden)

Chin-Tan Lee

2017-02-01

Full Text Available In this work, a novel electronic lock that can encode and decode optical signals, modulated using Morse code conventions, was developed to build a smart home security system based on the Internet of Things (IoT. There are five topics of interest in this research: (1 optical Morse code encoder; (2 optical Morse code decoder; (3 ambient light sensor circuit; (4 fuzzy controller; (5 cloud monitoring system. We take advantage of the light-emitting components as the encoder, which are readily available in hand-held mobile devices (e.g., Smart phones and photoresistors and a microcontroller as the decoder. By Wi-Fi transferring, even without a personal computer, real-time information about this lock can be uploaded to the cloud service platform, and helps users to ensure home safety on the remote monitoring system. By using the ambient light sensor and fuzzy controller in this novel optical Morse code-based electronic lock, experimental results show that the reliability of this system is much improved from 65% to 100%. That means that it is highly resistant to different illumination conditions in the work environment, and therefore all functions, including coding, emitting, receiving, decoding, uploading and cloud monitoring, can work well. Furthermore, besides the convenience and cost reduction, by incorporating traditional keys into smart phones, as a consumer electronics, our proposed system is suitable for users of all ages because of a user-friendly operation interface.

X-ray detector for automatic exposure control using ionization chamber filled with xenon gas

CERN Document Server

Nakagawa, A; Yoshida, T

2003-01-01

This report refers to our newly developed X-ray detector for reliable automatic X-ray exposure control, which is to be widely used for X-ray diagnoses in various clinical fields. This new detector utilizes an ionization chamber filled with xenon gas, in contrast to conventional X-ray detectors which use ionization chambers filled with air. Use of xenon gas ensures higher sensitivity and thinner design of the detector. The xenon gas is completely sealed in the chamber, so that the influence of the changes in ambient environments is minimized. (author)

Line shape and ray trace calculations in saturated X-ray lasers: Application to Ni-like silver

International Nuclear Information System (INIS)

Benredjem, D.; Guilbaud, O.; Moeller, C.; Klisnick, A.; Ros, D.; Dubau, J.; Calisti, A.; Talin, B.

2006-01-01

Longitudinal coherence length in X-ray lasers depends strongly on the shape of the amplified line. We have modelled an experiment performed at the LULI facility of Ecole Polytechnique. The experiment was devoted to the study of the temporal (longitudinal) coherence of the transient Ni-like silver 4d-4p transition X-ray laser at 13.9 nm. Accurate line shape calculations using PPP, a spectral line shape code, confirm that the Voigt profile is a good approximation for this X-ray laser line. This allows us to extensively use the Voigt shape in conditions where the amplifier, i.e. the plasma produced by the interaction of a high intensity laser with a slab target, is neither stationary nor homogeneous. Our calculations involve a ray trace code which is a post-processor to the hydrodynamic simulation EHYBRID. As the effect of saturation is important for the level populations and gains we include the interaction between the amplified beam and the medium using the Maxwell-Bloch formalism. While the FWHM of the spontaneous emission profile is ∼10 mA, the amplified X-ray line exhibits gain narrowing leading to the smaller width ∼3 mA. Comparison with experiment is discussed

X-ray metrology and performance of a 45-cm long x-ray deformable mirror

Energy Technology Data Exchange (ETDEWEB)

Poyneer, Lisa A., E-mail: poyneer1@llnl.gov; Brejnholt, Nicolai F.; Hill, Randall; Jackson, Jessie; Hagler, Lisle [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Celestre, Richard; Feng, Jun [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

2016-05-15

We describe experiments with a 45-cm long x-ray deformable mirror (XDM) that have been conducted in End Station 2, Beamline 5.3.1 at the Advanced Light Source. A detailed description of the hardware implementation is provided. We explain our one-dimensional Fresnel propagation code that correctly handles grazing incidence and includes a model of the XDM. This code is used to simulate and verify experimental results. Initial long trace profiler metrology of the XDM at 7.5 keV is presented. The ability to measure a large (150-nm amplitude) height change on the XDM is demonstrated. The results agree well with the simulated experiment at an error level of 1 μrad RMS. Direct imaging of the x-ray beam also shows the expected change in intensity profile at the detector.

Analysis of the variation of the attenuation curve in function of the radiation field size for k Vp X-ray beams using the MCNP-5C code

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Marco A.R., E-mail: marco@cetea.com.b, E-mail: marfernandes@fmb.unesp.b [Universidade Estadual Paulista Julio de Mesquita Filho (FMB/UNESP), Botucatu, SP (Brazil). Fac. de Medicina; Ribeiro, Victor A.B. [Universidade Estadual Paulista Julio de Mesquita Filho (IBB/UNESP), Botucatu, SP (Brazil). Inst. de Biociencias; Viana, Rodrigo S.S.; Coelho, Talita S. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

The paper illustrates the use of the Monte Carlo method, MCNP-5C code, to analyze the attenuation curve behavior of the 50 kVp radiation beam from superficial radiotherapy equipment as Dermopan2 model. The simulations seek to verify the MCNP-5C code performance to study the variation of the attenuation curve - percentage depth dose (PDD) curve - in function of the radiation field dimension used at radiotherapy of skin tumors with 50 kVp X-ray beams. The PDD curve was calculated for six different radiation field sizes with circular geometry of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 cm in diameter. The radiation source was modeled considering a tungsten target with inclination 30 deg, focal point of 6.5 mm in diameter and energy beam of 50 kVp; the X-ray spectrum was calculated with the MCNP-5C code adopting total filtration (beryllium window of 1 mm and aluminum additional filter of 1 mm). The PDD showed decreasing behavior with the attenuation depth similar what is presented on the literature. There was not significant variation at the PDD values for the radiation field between 1.0 and 4.0 cm in diameter. The differences increased for fields of 5.0 and 6.0 cm and at attenuation depth higher than 1.0 cm. When it is compared the PDD values for fields of 3.0 and 6.0 cm in diameter, it verifies the greater difference (12.6 %) at depth of 5.7 cm, proving the scattered radiation effect. The MCNP-5C code showed as an appropriate procedure to analyze the attenuation curves of the superficial radiotherapy beams. (author)

GOTHIC: Gravitational oct-tree code accelerated by hierarchical time step controlling

Science.gov (United States)

Miki, Yohei; Umemura, Masayuki

2017-04-01

The tree method is a widely implemented algorithm for collisionless N-body simulations in astrophysics well suited for GPU(s). Adopting hierarchical time stepping can accelerate N-body simulations; however, it is infrequently implemented and its potential remains untested in GPU implementations. We have developed a Gravitational Oct-Tree code accelerated by HIerarchical time step Controlling named GOTHIC, which adopts both the tree method and the hierarchical time step. The code adopts some adaptive optimizations by monitoring the execution time of each function on-the-fly and minimizes the time-to-solution by balancing the measured time of multiple functions. Results of performance measurements with realistic particle distribution performed on NVIDIA Tesla M2090, K20X, and GeForce GTX TITAN X, which are representative GPUs of the Fermi, Kepler, and Maxwell generation of GPUs, show that the hierarchical time step achieves a speedup by a factor of around 3-5 times compared to the shared time step. The measured elapsed time per step of GOTHIC is 0.30 s or 0.44 s on GTX TITAN X when the particle distribution represents the Andromeda galaxy or the NFW sphere, respectively, with 224 = 16,777,216 particles. The averaged performance of the code corresponds to 10-30% of the theoretical single precision peak performance of the GPU.

Sub-Transport Layer Coding

DEFF Research Database (Denmark)

Hansen, Jonas; Krigslund, Jeppe; Roetter, Daniel Enrique Lucani

2014-01-01

Packet losses in wireless networks dramatically curbs the performance of TCP. This paper introduces a simple coding shim that aids IP-layer traffic in lossy environments while being transparent to transport layer protocols. The proposed coding approach enables erasure correction while being...... oblivious to the congestion control algorithms of the utilised transport layer protocol. Although our coding shim is indifferent towards the transport layer protocol, we focus on the performance of TCP when ran on top of our proposed coding mechanism due to its widespread use. The coding shim provides gains...

SHADOW3: a new version of the synchrotron X-ray optics modelling package

International Nuclear Information System (INIS)

Sanchez del Rio, Manuel; Canestrari, Niccolo; Jiang, Fan; Cerrina, Franco

2011-01-01

SHADOW3, a new version of the X-ray tracing code SHADOW, is introduced. A new version of the popular X-ray tracing code SHADOW is presented. An important step has been made in restructuring the code following new computer engineering standards, ending with a modular Fortran 2003 structure and an application programming interface (API). The new code has been designed to be compatible with the original file-oriented SHADOW philosophy, but simplifying the compilation, installation and use. In addition, users can now become programmers using the newly designed SHADOW3 API for creating scripts, macros and programs; being able to deal with optical system optimization, image simulation, and also low transmission calculations requiring a large number of rays (>10 6 ). Plans for future development and questions on how to accomplish them are also discussed

Temporal coding of brain patterns for direct limb control in humans

Directory of Open Access Journals (Sweden)

Gernot Mueller-Putz

2010-06-01

Full Text Available For individuals with a high spinal cord injury (SCI not only the lower limbs, but also the upper extremities are paralyzed. A neuroprosthesis can be used to restore the lost hand and arm function in those tetraplegics. The main problem for this group of individuals, however, is the reduced ability to voluntarily operate device controllers. A Brain-Computer Interface provides a non-manual alternative to conventional input devices by translating brain activity patterns into control commands. We show that the temporal coding of individual mental imagery pattern can be used to control two independent degrees of freedom – grasp and elbow function - of an artificial robotic arm by utilizing a minimum number of EEG scalp electrodes. We describe the procedure from the initial screening to the final application. From eight naïve subjects participating on-line feedback experiments, four were able to voluntarily control an artificial arm by inducing one motor imagery pattern derived from one EEG derivation only.

Description of EMX computer code. System for measuring soft X rays

International Nuclear Information System (INIS)

Marty, D.A.; Smeulders, P.; Launois, D.

1978-07-01

After briefly describing the system for measuring soft X rays implanted in TFR 600, the objectives and principles of the E.M.X calculation programme are presented. This model is divided into two distinct parts. The ultimate aim of EMX 1, the first part, is to build the soft X ray photo of a plasma with varied characteristics, seen through a certain collimation system (in this case a slit). That of EMX 2, the second part, is to filter the previously built soft X ray photo, by means of the system of absorbents belonging to the measuring system and to calculate the currents generated by each detector aimed at a plasma chord. The first calculation results are commented and discussed [fr

Code of practice for radiation protection in veterinary medicine

International Nuclear Information System (INIS)

Duffy, J.; Fenton, D.; McGarry, A.; McAllister, H.; Skelly, C

2002-11-01

This Code of Practice updates the Code of Practice on Radiation Protection in Veterinary Radiology prepared by the Nuclear Energy Board in June 1989. The Code is designed to give guidance to veterinary surgeons to ensure that they, their employees and members of the public are adequately protected from the hazards of ionising radiation arising from the use of X-ray equipment and radioactive substances in the practice of veterinary medicine. It reflects the regulations as specified in the Radiological Protection Act, 1991, (Ionising Radiation) Order, 2000 (S.I. No. 125 of 2000)

Quality control for dental X-rays equipment and film developers

International Nuclear Information System (INIS)

Pomares C, Martin

1998-01-01

Quality control in five dental X-ray equipments, film and film developers was done. It was for evaluating the radiologic practices in the odontologic services too. This work was made based on international standards, the results will be used for future works in quality assurance in dental radiology

NPTFit: A Code Package for Non-Poissonian Template Fitting

International Nuclear Information System (INIS)

Mishra-Sharma, Siddharth; Rodd, Nicholas L.; Safdi, Benjamin R.

2017-01-01

We present NPTFit, an open-source code package, written in Python and Cython, for performing non-Poissonian template fits (NPTFs). The NPTF is a recently developed statistical procedure for characterizing the contribution of unresolved point sources (PSs) to astrophysical data sets. The NPTF was first applied to Fermi gamma-ray data to provide evidence that the excess of ∼GeV gamma-rays observed in the inner regions of the Milky Way likely arises from a population of sub-threshold point sources, and the NPTF has since found additional applications studying sub-threshold extragalactic sources at high Galactic latitudes. The NPTF generalizes traditional astrophysical template fits to allow for the ability to search for populations of unresolved PSs that may follow a given spatial distribution. NPTFit builds upon the framework of the fluctuation analyses developed in X-ray astronomy, thus it likely has applications beyond those demonstrated with gamma-ray data. The NPTFit package utilizes novel computational methods to perform the NPTF efficiently. The code is available at http://github.com/bsafdi/NPTFit and up-to-date and extensive documentation may be found at http://nptfit.readthedocs.io.

NPTFit: A Code Package for Non-Poissonian Template Fitting

Energy Technology Data Exchange (ETDEWEB)

Mishra-Sharma, Siddharth [Department of Physics, Princeton University, Princeton, NJ 08544 (United States); Rodd, Nicholas L.; Safdi, Benjamin R., E-mail: smsharma@princeton.edu, E-mail: nrodd@mit.edu, E-mail: bsafdi@mit.edu [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2017-06-01

We present NPTFit, an open-source code package, written in Python and Cython, for performing non-Poissonian template fits (NPTFs). The NPTF is a recently developed statistical procedure for characterizing the contribution of unresolved point sources (PSs) to astrophysical data sets. The NPTF was first applied to Fermi gamma-ray data to provide evidence that the excess of ∼GeV gamma-rays observed in the inner regions of the Milky Way likely arises from a population of sub-threshold point sources, and the NPTF has since found additional applications studying sub-threshold extragalactic sources at high Galactic latitudes. The NPTF generalizes traditional astrophysical template fits to allow for the ability to search for populations of unresolved PSs that may follow a given spatial distribution. NPTFit builds upon the framework of the fluctuation analyses developed in X-ray astronomy, thus it likely has applications beyond those demonstrated with gamma-ray data. The NPTFit package utilizes novel computational methods to perform the NPTF efficiently. The code is available at http://github.com/bsafdi/NPTFit and up-to-date and extensive documentation may be found at http://nptfit.readthedocs.io.

A library for X-ray-matter interaction cross sections for X-ray fluorescence applications

Energy Technology Data Exchange (ETDEWEB)

Brunetti, A. [Istituto di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy) and INFN, Sezione di Cagliari (Italy)]. E-mail: brunetti@uniss.it; Sanchez del Rio, M. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Golosio, B. [INFN, Sezione di Cagliari (Italy); European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Simionovici, A. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Laboratoire de Sciences de la Terre, Ecole Normale Superieure, Lyon, F-69364 (France); Somogyi, A. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France)

2004-10-08

Quantitative estimate of elemental composition by spectroscopic and imaging techniques using X-ray fluorescence requires the availability of accurate data of X-ray interaction with matter. Although a wide number of computer codes and data sets are reported in literature, none of them is presented in the form of freely available library functions which can be easily included in software applications for X-ray fluorescence. This work presents a compilation of data sets from different published works and an xraylib interface in the form of callable functions. Although the target applications are on X-ray fluorescence, cross sections of interactions like photoionization, coherent scattering and Compton scattering, as well as form factors and anomalous scattering functions, are also available.

TRACK The New Beam Dynamics Code

CERN Document Server

Mustapha, Brahim; Ostroumov, Peter; Schnirman-Lessner, Eliane

2005-01-01

The new ray-tracing code TRACK was developed* to fulfill the special requirements of the RIA accelerator systems. The RIA lattice includes an ECR ion source, a LEBT containing a MHB and a RFQ followed by three SC linac sections separated by two stripping stations with appropriate magnetic transport systems. No available beam dynamics code meet all the necessary requirements for an end-to-end simulation of the RIA driver linac. The latest version of TRACK was used for end-to-end simulations of the RIA driver including errors and beam loss analysis.** In addition to the standard capabilities, the code includes the following new features: i) multiple charge states ii) realistic stripper model; ii) static and dynamic errors iii) automatic steering to correct for misalignments iv) detailed beam-loss analysis; v) parallel computing to perform large scale simulations. Although primarily developed for simulations of the RIA machine, TRACK is a general beam dynamics code. Currently it is being used for the design and ...

Control area around dental x-ray units - dosimetric study I

International Nuclear Information System (INIS)

Suric Mihic, M.; Prlic, I.; Milkovic-Kraus, S.; Mestrovic, T.; Rojnica, F.

2005-01-01

The issue of prompt professional occupational dose reporting is raised when the interval between doses is short or when the radiation source suffers a technical failure. Every involved person should be able to recognised individual or group radiation exposure. Actual radiation quality of the source is to be taken into account. To optimise radiation protection of dental radiologists, dental x-ray units were subject to Quality Control measurements. Scattering radiation from the patient's dental structures was measured in order to prove the results published by S. Tabakov, but using the modern RVG dental mode and several classical diagnostic positions. We used a special head phantom (real scull + Perspex + crown glass) and common dental x-ray units of various brands and types. The radiation quality was measured using standard QA/QC equipment. We measured the radiation scattered from the phantom in the horizontal plane (at thyroid height) at 0.5 m distance from the centre of the phantom. The measurement were done for a number of standard dental x-ray procedures, but this paper presents only the scattering caused by the upper premolars. The attenuation in the facial tissue was minimal and the majority of incidental radiation passes through the open mouth of a patient directly into the room area causing occupational exposure. The results we obtained are consistent with earlier reports on patient dosimetry. Occupational exposure is much lower if a modern RVG technique is used and no radiation protection threshold is exceeded in relation to Croatian laws. Much more important is the fact that the need for protective equipment and shielding is smaller if QA warrants proper technical operation of the x-ray tube. The maintenance of dental units is essential and so is a proper training of staff using modern diagnostic techniques. The control area around the x-ray unit is to be calculated and established for every standard dental unit (this does not apply for panoramic x-rays

Quality control assessment of diagnostic X-ray facilities in Ghana ...

African Journals Online (AJOL)

Twenty-three X-ray machines located at 20 different hospitals in Ghana were assessed for quality assurance and control. The radiographic parameters evaluated were tube voltage and current, tube output consistency variation with kilovoltage (kV) and current-time (mAs) factor, exposure time accuracy and beam quality as ...

Study of salinity in aqueous medium using X-Ray beam with MCNP-X code

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Caroline M.; Braz, Delson [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Salgado, César M., E-mail: cbarbosa@nuclear.ufrj.br, E-mail: delson@nuclear.ufrj.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

In offshore production, it is possible that the produced water presents geochemical characteristics that correspond to the mixture of formation water (connate water) and the sea water (injection water), and the physical-chemical behavior of the injected water allows a considerable variation in the index of salinity altering the water/oil ratio during transportation and/or extraction. Injection water is generally used to raise the reservoir pressure, increasing the percentage of extracted oil. This water has a significant amount of salts that generate some difficulties, such as measuring fractions of volume in multiphase systems. One way to check the effects of salinity would be to regularly measure the amount of salt present in the water. In this way, this work presents a methodology to measure the concentration and the types of salts using nuclear techniques through the MCNP-X computational code. The measurement geometry uses an X-ray beam (40-100 keV) and NaI(Tl) scintillation detector positioned diametrically opposed to the source. The studied samples were the NaCl, KCl and MgCl{sub 2} salts in aqueous solution. The results present the possibility of differentiating the formation and injection waters due to differences in the salt concentrations. (author)

Characterization and control of femtosecond electron and X-ray beams at free-electron lasers

International Nuclear Information System (INIS)

Behrens, Christopher

2012-11-01

X-ray free-electron lasers (FELs) open up new frontiers in photon science, and in order to take full advantage of these unique accelerator-based light sources, the characterization and control of the femtosecond electron and X-ray beams is essential. Within this cumulative thesis, recent results achieved within the active research field of femtosecond electron and X-ray beams at FELs are reported.The basic principles of X-ray FELs are described, and concepts of longitudinal electron beam diagnostics with femtosecond accuracy are covered. Experimental results obtained with a transverse deflecting structure (TDS) and spectroscopy of coherent terahertz radiation are presented, and the suppression of coherent optical radiation effects, required for diagnostics utilizing a TDS, is demonstrated. Control of the longitudinal phase space by using multiple radio frequencies for longitudinal electron beam tailoring is presented, and a new technique of reversible electron beam heating with two TDSs is described. For the characterization of femtosecond X-ray pulses, a novel method based on dedicated longitudinal phase space diagnostics for electron beams is introduced, and recent measurements with a streaking technique using external terahertz fields are presented.

Characterization and control of femtosecond electron and X-ray beams at free-electron lasers

Energy Technology Data Exchange (ETDEWEB)

Behrens, Christopher

2012-11-15

X-ray free-electron lasers (FELs) open up new frontiers in photon science, and in order to take full advantage of these unique accelerator-based light sources, the characterization and control of the femtosecond electron and X-ray beams is essential. Within this cumulative thesis, recent results achieved within the active research field of femtosecond electron and X-ray beams at FELs are reported.The basic principles of X-ray FELs are described, and concepts of longitudinal electron beam diagnostics with femtosecond accuracy are covered. Experimental results obtained with a transverse deflecting structure (TDS) and spectroscopy of coherent terahertz radiation are presented, and the suppression of coherent optical radiation effects, required for diagnostics utilizing a TDS, is demonstrated. Control of the longitudinal phase space by using multiple radio frequencies for longitudinal electron beam tailoring is presented, and a new technique of reversible electron beam heating with two TDSs is described. For the characterization of femtosecond X-ray pulses, a novel method based on dedicated longitudinal phase space diagnostics for electron beams is introduced, and recent measurements with a streaking technique using external terahertz fields are presented.

Neutron Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B. W.; Summers, N.; Escher, J.; Firestone, R. B.; Basunia, S.; Hurst, A.; Krticka, M.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H. D.

2011-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

Neutron Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B.W.; Firestone, R.B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

2010-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. this can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. They are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

A microcomputer controlled sample changer system for γ-ray spectroscopy

International Nuclear Information System (INIS)

Jost, D.T.; Kraehenbuehl, U.; Gunten, H.R. von

1982-01-01

A Z-80 based microcomputer is used to control a sample changer system connected to two γ-ray spectrometers. Samples are changed according to preselected counting criteria (maximum time and/or desired precision). Special precautions were taken to avoid the loss of information and of samples in case of a power failure. (orig.)

SHADOW3: a new version of the synchrotron X-ray optics modelling package

Energy Technology Data Exchange (ETDEWEB)

Sanchez del Rio, Manuel, E-mail: srio@esrf.eu [European Synchrotron Radiation Facility, 6 Jules Horowitz, 38000 Grenoble (France); Canestrari, Niccolo [CNRS, Grenoble (France); European Synchrotron Radiation Facility, 6 Jules Horowitz, 38000 Grenoble (France); Jiang, Fan; Cerrina, Franco [Boston University, 8 St Mary’s Street, Boston, MA 02215 (United States)

2011-09-01

SHADOW3, a new version of the X-ray tracing code SHADOW, is introduced. A new version of the popular X-ray tracing code SHADOW is presented. An important step has been made in restructuring the code following new computer engineering standards, ending with a modular Fortran 2003 structure and an application programming interface (API). The new code has been designed to be compatible with the original file-oriented SHADOW philosophy, but simplifying the compilation, installation and use. In addition, users can now become programmers using the newly designed SHADOW3 API for creating scripts, macros and programs; being able to deal with optical system optimization, image simulation, and also low transmission calculations requiring a large number of rays (>10{sup 6}). Plans for future development and questions on how to accomplish them are also discussed.

Development of Mathematical Model and Analysis Code for Estimating Drop Behavior of the Control Rod Assembly in the Sodium Cooled Fast Reactor

International Nuclear Information System (INIS)

Oh, Se-Hong; Kang, SeungHoon; Choi, Choengryul; Yoon, Kyung Ho; Cheon, Jin Sik

2016-01-01

On receiving the scram signal, the control rod assemblies are released to fall into the reactor core by its weight. Thus drop time and falling velocity of the control rod assembly must be estimated for the safety evaluation. There are three typical ways to estimate the drop behavior of the control rod assembly in scram action: Experimental, numerical and theoretical methods. But experimental and numerical(CFD) method require a lot of cost and time. Thus, these methods are difficult to apply to the initial design process. In this study, mathematical model and theoretical analysis code have been developed in order to estimate drop behavior of the control rod assembly to provide the underlying data for the design optimization. Mathematical model and theoretical analysis code have been developed in order to estimate drop behavior of the control rod assembly to provide the underlying data for the design optimization. A simplified control rod assembly model is considered to minimize the uncertainty in the development process. And the hydraulic circuit analysis technique is adopted to evaluate the internal/external flow distribution of the control rod assembly. Finally, the theoretical analysis code(named as HEXCON) has been developed based on the mathematical model. To verify the reliability of the developed code, CFD analysis has been conducted. And a calculation using the developed analysis code was carried out under the same condition, and both results were compared

A study on feasibility of insect-control with γ-ray

International Nuclear Information System (INIS)

Huifen Feng; Jingren Li; Xin Hu

1993-01-01

Insect-control with Co-γ-ray is a method for conserving archives, books, cotton textiles, historical relics, wood structured houses and furniture. The temporary and residual effects of γ-ray on irradiated objects and the biological effects on insects are presented in this report. Our study shows that there is no obvious harmful effect on irradiated objects when the radiation dose is below 870 Gy, while there is obvious deterioration to the objects when the dose is above 870 Gy. On the other hand, a dose below 870 Gy is strong enough for the insects to be affected. At the dose of 43.5 - 130.5 Gy, the irradiated insects' reproductive function could be damaged or insects killed. (author)

Using computational modeling to compare X-ray tube Practical Peak Voltage for Dental Radiology

International Nuclear Information System (INIS)

Holanda Cassiano, Deisemar; Arruda Correa, Samanda Cristine; Monteiro de Souza, Edmilson; Silva, Ademir Xaxier da; Pereira Peixoto, José Guilherme; Tadeu Lopes, Ricardo

2014-01-01

The Practical Peak Voltage-PPV has been adopted to measure the voltage applied to an X-ray tube. The PPV was recommended by the IEC document and accepted and published in the TRS no. 457 code of practice. The PPV is defined and applied to all forms of waves and is related to the spectral distribution of X-rays and to the properties of the image. The calibration of X-rays tubes was performed using the MCNPX Monte Carlo code. An X-ray tube for Dental Radiology (operated from a single phase power supply) and an X-ray tube used as a reference (supplied from a constant potential power supply) were used in simulations across the energy range of interest of 40 kV to 100 kV. Results obtained indicated a linear relationship between the tubes involved. - Highlights: • Computational Model was developed to X-ray tube Practical Peak Voltage for Dental Radiology. • The calibration of X-rays tubes was performed using the MCNPX Monte Carlo code. • The energy range was 40–100 kV. • Results obtained indicated a linear relationship between the Dental Radiology and reference X-ray tubes

Time-resolved suprathermal x-rays

International Nuclear Information System (INIS)

Lee, P.H.Y.; Rosen, M.D.

1978-01-01

Temporally resolved x-ray spectra in the range of 1 to 20 keV have been obtained from gold disk targets irradiated by 1.06 μm laser pulses from the Argus facility. The x-ray streak camera used for the measurement has been calibrated for streak speed and dynamic range by using an air-gap Fabry-Perot etalon, and the instrument response has been calibrated using a multi-range monoenergetic x-ray source. The experimental results indicate that we are able to observe the ''hot'' x-ray temperature evolve in time and that the experimentally observed values can be qualitatively predicted by LASNEX code computations when the inhibited transport model is used

Low Complexity List Decoding for Polar Codes with Multiple CRC Codes

Directory of Open Access Journals (Sweden)

Jong-Hwan Kim

2017-04-01

Full Text Available Polar codes are the first family of error correcting codes that provably achieve the capacity of symmetric binary-input discrete memoryless channels with low complexity. Since the development of polar codes, there have been many studies to improve their finite-length performance. As a result, polar codes are now adopted as a channel code for the control channel of 5G new radio of the 3rd generation partnership project. However, the decoder implementation is one of the big practical problems and low complexity decoding has been studied. This paper addresses a low complexity successive cancellation list decoding for polar codes utilizing multiple cyclic redundancy check (CRC codes. While some research uses multiple CRC codes to reduce memory and time complexity, we consider the operational complexity of decoding, and reduce it by optimizing CRC positions in combination with a modified decoding operation. Resultingly, the proposed scheme obtains not only complexity reduction from early stopping of decoding, but also additional reduction from the reduced number of decoding paths.

Development of the super high angular resolution principle for X-ray imaging

International Nuclear Information System (INIS)

Zhang Chen; Zhang Shuangnan

2011-01-01

Development of the Super High Angular Resolution Principle (SHARP) for coded-mask X-ray imaging is presented. We prove that SHARP can be considered as a generalized coded mask imaging method with a coding pattern comprised of diffraction-interference fringes in the mask pattern. The angular resolution of SHARP can be improved by detecting the fringes more precisely than the mask's element size, i.e. by using a detector with a pixel size smaller than the mask's element size. The proposed mission SHARP-X for solar X-ray observations is also briefly discussed. (research papers)

Monte Carlo simulations of plutonium gamma-ray spectra

International Nuclear Information System (INIS)

Koenig, Z.M.; Carlson, J.B.; Wang, Tzu-Fang; Ruhter, W.D.

1993-01-01

Monte Carlo calculations were investigated as a means of simulating the gamma-ray spectra of Pu. These simulated spectra will be used to develop and evaluate gamma-ray analysis techniques for various nondestructive measurements. Simulated spectra of calculational standards can be used for code intercomparisons, to understand systematic biases and to estimate minimum detection levels of existing and proposed nondestructive analysis instruments. The capability to simulate gamma-ray spectra from HPGe detectors could significantly reduce the costs of preparing large numbers of real reference materials. MCNP was used for the Monte Carlo transport of the photons. Results from the MCNP calculations were folded in with a detector response function for a realistic spectrum. Plutonium spectrum peaks were produced with Lorentzian shapes, for the x-rays, and Gaussian distributions. The MGA code determined the Pu isotopes and specific power of this calculated spectrum and compared it to a similar analysis on a measured spectrum

Recent improvements of the TNG statistical model code

International Nuclear Information System (INIS)

Shibata, K.; Fu, C.Y.

1986-08-01

The applicability of the nuclear model code TNG to cross-section evaluations has been extended. The new TNG is capable of using variable bins for outgoing particle energies. Moreover, three additional quantities can now be calculated: capture gamma-ray spectrum, the precompound mode of the (n,γ) reaction, and fission cross section. In this report, the new features of the code are described together with some sample calculations and a brief explanation of the input data. 15 refs., 6 figs., 2 tabs

Optomechanical Design of a Hard X-ray Nanoprobe Instrument with Nanometer-Scale Active Vibration Control

International Nuclear Information System (INIS)

Shu, D.; Preissner, C.; Smolyanitskiy, A.; Maser, J.; Winarski, R.; Holt, M.; Lai, B.; Vogt, S.; Stephenson, G. B.

2007-01-01

We are developing a new hard x-ray nanoprobe instrument that is one of the centerpieces of the characterization facilities of the Center for Nanoscale Materials being constructed at Argonne National Laboratory. This new probe will cover an energy range of 3-30 keV with 30-nm spacial resolution. The system is designed to accommodate x-ray optics with a resolution limit of 10 nm, therefore, it requires staging of x-ray optics and specimens with a mechanical repeatability of better than 5 nm. Fast feedback for differential vibration control between the zone-plate x-ray optics and the sample holder has been implemented in the design using a digital-signal-processor-based real-time closed-loop feedback technique. A specially designed, custom-built laser Doppler displacement meter system provides two-dimensional differential displacement measurements with subnanometer resolution between the zone-plate x-ray optics and the sample holder. The optomechanical design of the instrument positioning stage system with nanometer-scale active vibration control is presented in this paper

Cosmic ray transport in heliospheric magnetic structures. I. Modeling background solar wind using the CRONOS magnetohydrodynamic code

Energy Technology Data Exchange (ETDEWEB)

Wiengarten, T.; Kleimann, J.; Fichtner, H. [Institut für Theoretische Physik IV, Ruhr-Universität Bochum (Germany); Kühl, P.; Kopp, A.; Heber, B. [Institut für Experimentelle und Angewandte Physik, Christian-Albrecht-Universität zu Kiel (Germany); Kissmann, R. [Institut für Astro- und Teilchenphysik, Universität Innsbruck (Austria)

2014-06-10

The transport of energetic particles such as cosmic rays is governed by the properties of the plasma being traversed. While these properties are rather poorly known for galactic and interstellar plasmas due to the lack of in situ measurements, the heliospheric plasma environment has been probed by spacecraft for decades and provides a unique opportunity for testing transport theories. Of particular interest for the three-dimensional (3D) heliospheric transport of energetic particles are structures such as corotating interaction regions, which, due to strongly enhanced magnetic field strengths, turbulence, and associated shocks, can act as diffusion barriers on the one hand, but also as accelerators of low energy CRs on the other hand as well. In a two-fold series of papers, we investigate these effects by modeling inner-heliospheric solar wind conditions with a numerical magnetohydrodynamic (MHD) setup (this paper), which will serve as an input to a transport code employing a stochastic differential equation approach (second paper). In this first paper, we present results from 3D MHD simulations with our code CRONOS: for validation purposes we use analytic boundary conditions and compare with similar work by Pizzo. For a more realistic modeling of solar wind conditions, boundary conditions derived from synoptic magnetograms via the Wang-Sheeley-Arge (WSA) model are utilized, where the potential field modeling is performed with a finite-difference approach in contrast to the traditional spherical harmonics expansion often utilized in the WSA model. Our results are validated by comparing with multi-spacecraft data for ecliptical (STEREO-A/B) and out-of-ecliptic (Ulysses) regions.

A new Monte Carlo code for simulation of the effect of irregular surfaces on X-ray spectra

Energy Technology Data Exchange (ETDEWEB)

Brunetti, Antonio, E-mail: brunetti@uniss.it; Golosio, Bruno

2014-04-01

Generally, quantitative X-ray fluorescence (XRF) analysis estimates the content of chemical elements in a sample based on the areas of the fluorescence peaks in the energy spectrum. Besides the concentration of the elements, the peak areas depend also on the geometrical conditions. In fact, the estimate of the peak areas is simple if the sample surface is smooth and if the spectrum shows a good statistic (large-area peaks). For this reason often the sample is prepared as a pellet. However, this approach is not always feasible, for instance when cultural heritage or valuable samples must be analyzed. In this case, the sample surface cannot be smoothed. In order to address this problem, several works have been reported in the literature, based on experimental measurements on a few sets of specific samples or on Monte Carlo simulations. The results obtained with the first approach are limited by the specific class of samples analyzed, while the second approach cannot be applied to arbitrarily irregular surfaces. The present work describes a more general analysis tool based on a new fast Monte Carlo algorithm, which is virtually able to simulate any kind of surface. At the best of our knowledge, it is the first Monte Carlo code with this option. A study of the influence of surface irregularities on the measured spectrum is performed and some results reported. - Highlights: • We present a fast Monte Carlo code with the possibility to simulate any irregularly rough surfaces. • We show applications to multilayer measurements. • Real time simulations are available.

Rod behaviour under base load, load follow and frequency control operation: CYRANO 2 code predictions versus experimental results

International Nuclear Information System (INIS)

Gautier, B.; Raybaud, A.

1984-01-01

The French PWR reactors are now currently operating under load follow and frequency control. In order to demonstrate that these operating conditions were not able to increase the fuel failure rate, fuel rod behaviour calculations have been performed by E.D.F. with CYRANO 2 code. In parallel with these theoretical calculations, code predictions have been compared to experimental results. The paper presents some of the comparisons performed on 17x17 fuel irradiated in FESSENHEIM 2 up to 30 GWd/tU under base load operation and in the CAP reactor under load follow and frequency control conditions. It is shown that experimental results can be predicted with a reasonable accuracy by CYRANO 2 code. The experimental work was carried out under joint R and D programs by EDF, FRAGEMA, CEA, and WESTINGHOUSE (CAP program by French partners only). (author)

Evaluation of control room habitability in case of LOCA for Maanshan NPP using codes RADTRAD, HABIT and ALOHA

International Nuclear Information System (INIS)

Hsu, Wen-Sheng; Wang, Jong-Rong; Chen, Hsiung-Chih; Chiang, Yu; Chen, Shao-Wen; Shih, Chunkuan

2018-01-01

The method for the evaluation of the control room habitability is presented in this paper with focus on Maanshan PWR nuclear power plant (NPP) using the codes RADTRAD, HABIT, and ALOHA. Therefore, this paper is divided into two parts: The first part is the evaluation of the cumulative dose at the control room, the exclusion area boundary (EAB) and the low population zone (LPZ) in case of an design basis loss of coolant accident (DBA/LOCA). For this first part, the Maanshan NPP models of the code RADTRAD/SNAP were used for the analysis. The second part is the evaluation of the control room habitability under the assumption of CO 2 storage burst. For this part, the HABIT and ALOHA codes were used. As result it was seen that the RADTRAD calculation results are below the failure criteria of standard review plan (SRP) and 10 CFR 100.11. The HABIT and ALOHA results are below the R.G. 1.78 failure criteria. These results indicate that Maanshan NPP' habitability can be maintained under the above conditions.

Pair production from nuclear collisions and cosmic ray transport

International Nuclear Information System (INIS)

Norbury, John W

2006-01-01

Modern cosmic ray transport codes, that are capable of use for a variety of applications, need to include all significant atomic, nuclear and particle reactions at a variety of energies. Lepton pair production from nucleus-nucleus collisions has not been included in transport codes to date. Using the methods of Baur, Bertulani and Baron, the present report provides estimates of electron-positron pair production cross sections for nuclei and energies relevant to cosmic ray transport. It is shown that the cross sections are large compared to other typical processes such as single neutron removal due to strong or electromagnetic interactions. Therefore, lepton pair production may need to be included in some transport code applications involving MeV electrons. (brief report)

ACE - Manufacturer Identification Code (MID)

Data.gov (United States)

Department of Homeland Security — The ACE Manufacturer Identification Code (MID) application is used to track and control identifications codes for manufacturers. A manufacturer is identified on an...

Optimization of the Penelope code in F language for the simulation of the X-ray spectrum in radiodiagnosis; Optimizacion del codigo PENELOPE en lenguage F para la simulacion del espectro de rayos X en radiodiagnostico

Energy Technology Data Exchange (ETDEWEB)

Ballon P, C. I.; Quispe V, N. Y.; Vega R, J. L. J., E-mail: cballon@scifreelancer.com [Universidad Nacional de San Agustin de Arequipa, Av. Independencia s/n, 04000 Arequipa (Peru)

2017-10-15

The computational simulation to obtain the X-ray spectrum in the range of radio-diagnosis, allows a study and advance knowledge of the transport process of X-rays in the interaction with matter using the Monte Carlo method. With the obtaining of the X-ray spectra we can know the dose that the patient receives when he undergoes a radiographic study or CT, improving the quality of the obtained image. The objective of the present work was to implement and optimize the open source Penelope (Monte Carlo code for the simulation of the transport of electrons and photons in the matter) 2008 version programming extra code in functional language F, managing to double the processing speed, thus reducing the simulation time spent and errors when optimizing the software initially programmed in Fortran 77. The results were compared with those of Penelope, obtaining a good concordance. We also simulated the obtaining of a Pdd curve (depth dose profile) for a Theratron Equinox cobalt-60 teletherapy device, also validating the software implemented for high energies. (Author)

Theory of epigenetic coding.

Science.gov (United States)

Elder, D

1984-06-07

The logic of genetic control of development may be based on a binary epigenetic code. This paper revises the author's previous scheme dealing with the numerology of annelid metamerism in these terms. Certain features of the code had been deduced to be combinatorial, others not. This paradoxical contrast is resolved here by the interpretation that these features relate to different operations of the code; the combinatiorial to coding identity of units, the non-combinatorial to coding production of units. Consideration of a second paradox in the theory of epigenetic coding leads to a new solution which further provides a basis for epimorphic regeneration, and may in particular throw light on the "regeneration-duplication" phenomenon. A possible test of the model is also put forward.

Near edge x-ray spectroscopy theory

International Nuclear Information System (INIS)

1994-01-01

We propose to develop a quantitative theory of x-ray spectroscopies in the near edge region, within about 100 eV of threshold. These spectroscopies include XAFS (X-ray absorption fine structure), photoelectron diffraction (PD), and diffraction anomalous fine structure (DAFS), all of which are important tools for structural studies using synchrotron radiation x-ray sources. Of primary importance in these studies are many-body effects, such as the photoelectron self-energy, and inelastic losses. A better understanding of these quantities is needed to obtain theories without adjustable parameters. We propose both analytical and numerical calculations, the latter based on our x-ray spectroscopy codes FEFF

Experimental benchmark of non-local-thermodynamic-equilibrium plasma atomic physics codes

International Nuclear Information System (INIS)

Nagels-Silvert, V.

2004-09-01

The main purpose of this thesis is to get experimental data for the testing and validation of atomic physics codes dealing with non-local-thermodynamical-equilibrium plasmas. The first part is dedicated to the spectroscopic study of xenon and krypton plasmas that have been produced by a nanosecond laser pulse interacting with a gas jet. A Thomson scattering diagnostic has allowed us to measure independently plasma parameters such as electron temperature, electron density and the average ionisation state. We have obtained time integrated spectra in the range between 5 and 10 angstroms. We have identified about one hundred xenon rays between 8.6 and 9.6 angstroms via the use of the Relac code. We have discovered unknown rays for the krypton between 5.2 and 7.5 angstroms. In a second experiment we have extended the wavelength range to the X UV domain. The Averroes/Transpec code has been tested in the ranges from 9 to 15 angstroms and from 10 to 130 angstroms, the first range has been well reproduced while the second range requires a more complex data analysis. The second part is dedicated to the spectroscopic study of aluminium, selenium and samarium plasmas in femtosecond operating rate. We have designed an interferometry diagnostic in the frequency domain that has allowed us to measure the expanding speed of the target's backside. Via the use of an adequate isothermal model this parameter has led us to know the plasma electron temperature. Spectra and emission times of various rays from the aluminium and selenium plasmas have been computed satisfactorily with the Averroes/Transpec code coupled with Film and Multif hydrodynamical codes. (A.C.)

Microstructures for high-energy x-ray and particle-imaging applications

International Nuclear Information System (INIS)

Ceglio, N.M.; Stone, G.F.; Hawryluk, A.M.

1981-05-01

Coded imaging techniques using thick, micro-Fresnel zone plates as coded apertures have been used to image x-ray emissions (2-20 keV) and 3.5 MeV Alpha particle emissions from laser driven micro-implosions. Image resolution in these experiments was 3-8 μm. Extension of this coded imaging capability to higher energy x-rays (approx. 100 keV) and more penetrating charged particles (e.g. approx. 15 MeV protons) requires the fabrication of very thick (50-200 μm), high aspect ratio (10:1), gold Fresnel zone plates with narrow linewidths (5-25 μm) for use as coded aperatures. A reactive ion etch technique in oxygen has been used to produce thick zone plate patterns in polymer films. The polymer patterns serve as electroplating molds for the subsequent fabrication of the free-standing gold zone plate structures

A Distributed Flow Rate Control Algorithm for Networked Agent System with Multiple Coding Rates to Optimize Multimedia Data Transmission

Directory of Open Access Journals (Sweden)

Shuai Zeng

2013-01-01

Full Text Available With the development of wireless technologies, mobile communication applies more and more extensively in the various walks of life. The social network of both fixed and mobile users can be seen as networked agent system. At present, kinds of devices and access network technology are widely used. Different users in this networked agent system may need different coding rates multimedia data due to their heterogeneous demand. This paper proposes a distributed flow rate control algorithm to optimize multimedia data transmission of the networked agent system with the coexisting various coding rates. In this proposed algorithm, transmission path and upload bandwidth of different coding rate data between source node, fixed and mobile nodes are appropriately arranged and controlled. On the one hand, this algorithm can provide user nodes with differentiated coding rate data and corresponding flow rate. On the other hand, it makes the different coding rate data and user nodes networked, which realizes the sharing of upload bandwidth of user nodes which require different coding rate data. The study conducts mathematical modeling on the proposed algorithm and compares the system that adopts the proposed algorithm with the existing system based on the simulation experiment and mathematical analysis. The results show that the system that adopts the proposed algorithm achieves higher upload bandwidth utilization of user nodes and lower upload bandwidth consumption of source node.

QUIC: a chemical kinetics code for use with the chemical equilibrium code QUIL

International Nuclear Information System (INIS)

Lunsford, J.L.

1977-10-01

A chemical rate kinetics code QUIC is described, along with a support code RATE. QUIC is designed to allow chemical kinetics calculations on a wide variety of chemical environments while operating in the overlay environment of the chemical equilibrium code QUIL. QUIC depends upon a rate-data library called LIBR. This library is maintained by RATE. RATE enters into the library all reactions in a standardized format. The code QUIC, operating in conjunction with QUIL, is interactive and written to be used from a remote terminal, with paging control provided. Plotted output is also available

A wide field X-ray camera

International Nuclear Information System (INIS)

Sims, M.; Turner, M.J.L.; Willingale, R.

1980-01-01

A wide field of view X-ray camera based on the Dicke or Coded Mask principle is described. It is shown that this type of instrument is more sensitive than a pin-hole camera, or than a scanning survey of a given region of sky for all wide field conditions. The design of a practical camera is discussed and the sensitivity and performance of the chosen design are evaluated by means of computer simulations. The Wiener Filter and Maximum Entropy methods of deconvolution are described and these methods are compared with each other and cross-correlation using data from the computer simulations. It is shown that the analytic expressions for sensitivity used by other workers are confirmed by the simulations, and that ghost images caused by incomplete coding can be substantially eliminated by the use of the Wiener Filter and the Maximum Entropy Method, with some penalty in computer time for the latter. The cyclic mask configuration is compared with the simple mask camera. It is shown that when the diffuse X-ray background dominates, the simple system is more sensitive and has the better angular resolution. When sources dominate the simple system is less sensitive. It is concluded that the simple coded mask camera is the best instrument for wide field imaging of the X-ray sky. (orig.)

Coding and decoding for code division multiple user communication systems

Science.gov (United States)

Healy, T. J.

1985-01-01

A new algorithm is introduced which decodes code division multiple user communication signals. The algorithm makes use of the distinctive form or pattern of each signal to separate it from the composite signal created by the multiple users. Although the algorithm is presented in terms of frequency-hopped signals, the actual transmitter modulator can use any of the existing digital modulation techniques. The algorithm is applicable to error-free codes or to codes where controlled interference is permitted. It can be used when block synchronization is assumed, and in some cases when it is not. The paper also discusses briefly some of the codes which can be used in connection with the algorithm, and relates the algorithm to past studies which use other approaches to the same problem.

Procedure and code for calculating black control rods taking into account epithermal absorption, code CAS-1; Postupak i program za proracun crnih kontrolnih sipki, uzimajuci u obzir i epitermalnu apsorpciju, CAS-1

Energy Technology Data Exchange (ETDEWEB)

Martinc, R; Trivunac, N; Zivkovic, Z [Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

1964-12-15

This report describes the computer code CAS-1, calculation method and procedure applied for calculating the black control rods taking into account the epithermal neutron absorption. Results obtained for supercell method applied for regular lattice reflected in the multiplication medium is part of this report in addition to the computer code manual.

Current aspects in the development of the quality control in the conventional X-ray diagnostic radiology

International Nuclear Information System (INIS)

Stoeva, M.; Velkova, K.

2004-01-01

The role of the X-ray diagnostic radiology as one of the main factors forming the general public dose is indisputable. Following the requirement for justification of the application of X-rays for medical purposes, certain criteria for assessment of the parameters of the X-ray diagnostic equipment are formed and maximum permissible values defined. The latter are developed by the international and national radiation protection organizations and introduced both in the international and national legislation. The importance of the quality assurance concept for the radiation protection of the patient and staff in diagnostic radiology turned the quality control into main toll for obtaining high quality images with minimum dose to the patient and staff. X-ray diagnostics is one of the most common methods used in the medical practice. This is the main reason for the increase of the quality control protocols, winch makes their handling difficult. The latest developments in this area bring forward the idea for the development of specialized quality control software, which is capable of: 1) full or semi-automated calculation and assessment of the parameters of the X-ray diagnostic units; 2) tools for data handling and access; 3) tools for data analysis based on predefined procedures

Controlled agglomeration of Tb-doped Y2O3 nanocrystals studied by x-ray absorption fine structure, x-ray excited luminescence, and photoluminescence

International Nuclear Information System (INIS)

Soo, Y.L.; Huang, S.W.; Kao, Y.H.; Chhabra, V.; Kulkarni, B.; Veliadis, J.V.; Bhargava, R.N.

1999-01-01

Local environment surrounding Y atoms in Y 2 O 3 :Tb nanocrystals under various heat treatment conditions has been investigated by using the extended x-ray absorption fine structure (EXAFS) technique. X-ray excited luminescence (XEL) with the incident x-ray energy near Y K edge and Tb L edges has also been measured to investigate the mechanisms of x-ray-to-visible down conversion in these doped nanoparticles. The observed changes in EXAFS, XEL, and photoluminescent data can be explained on the basis of increased average size of the nanoparticles as confirmed by transmission electron microscopy studies. Our results thus demonstrate that the doped nanoparticles can agglomerate to a controllable degree by varying the heat treatment temperature. At higher temperatures, the local environment surrounding Y atoms in the nanoparticles is found to become similar to that in bulk Y 2 O 3 while the XEL output still shows the characteristics of nanocrystals. These results indicate that appropriate heat treatment can afford an effective means to control the intensity and signal-to-background ratio of green luminescence output of these doped nanocrystal phosphors, potentially useful for some device applications. copyright 1999 American Institute of Physics

Motion control system of MAX IV Laboratory soft x-ray beamlines

International Nuclear Information System (INIS)

Sjöblom, Peter; Lindberg, Mirjam; Forsberg, Johan; Persson, Andreas G.; Urpelainen, Samuli; Såthe, Conny

2016-01-01

At the MAX IV Laboratory, five new soft x-ray beamlines are under development. The first is Species and it will be used to develop and set the standard of the control system, which will be common across the facility. All motion axes at MAX IV will be motorized using stepper motors steered by the IcePAP motion controller and a mixture of absolute and incremental encoders following a predefined coordinate system. The control system software is built in Tango and uses the Python-based Sardana framework. The user controls the entire beamline through a synoptic overview and Sardana is used to run the scans.

Motion control system of MAX IV Laboratory soft x-ray beamlines

Energy Technology Data Exchange (ETDEWEB)

Sjöblom, Peter, E-mail: peter.sjoblom@maxlab.lu.se; Lindberg, Mirjam, E-mail: mirjam.lindberg@maxlab.lu.se; Forsberg, Johan, E-mail: johan.forsberg@maxlab.lu.se; Persson, Andreas G., E-mail: andreas-g.persson@maxlab.lu.se; Urpelainen, Samuli, E-mail: samuli.urpelainen@maxlab.lu.se; Såthe, Conny, E-mail: conny.sathe@maxlab.lu.se [MAX IV Laboratory, Photongatan 2, 225 92 Lund (Sweden)

2016-07-27

At the MAX IV Laboratory, five new soft x-ray beamlines are under development. The first is Species and it will be used to develop and set the standard of the control system, which will be common across the facility. All motion axes at MAX IV will be motorized using stepper motors steered by the IcePAP motion controller and a mixture of absolute and incremental encoders following a predefined coordinate system. The control system software is built in Tango and uses the Python-based Sardana framework. The user controls the entire beamline through a synoptic overview and Sardana is used to run the scans.

Developments of HTGR thermofluid dynamic analysis codes and HTGR plant dynamic simulation code

International Nuclear Information System (INIS)

Tanaka, Mitsuhiro; Izaki, Makoto; Koike, Hiroyuki; Tokumitsu, Masashi

1983-01-01

In nuclear power plants as well as high temperature gas-cooled reactor plants, the design is mostly performed on the basis of the results after their characteristics have been grasped by carrying out the numerical simulation using the analysis code. Also in Kawasaki Heavy Industries Ltd., on the basis of the system engineering accumulated with gas-cooled reactors since several years ago, the preparation and systematization of analysis codes have been advanced, aiming at lining up the analysis codes for heat transferring flow and control characteristics, taking up HTGR plants as the main object. In this report, a part of the results is described. The example of the analysis applying the two-dimensional compressible flow analysis codes SOLA-VOF and SALE-2D, which were developed by Los Alamos National Laboratory in USA and modified for use in Kawasaki, to HTGR system is reported. Besides, Kawasaki has developed the control characteristics analyzing code DYSCO by which the change of system composition is easy and high versatility is available. The outline, fundamental equations, fundamental algorithms and examples of application of the SOLA-VOF and SALE-2D, the present status of system characteristic simulation codes and the outline of the DYSCO are described. (Kako, I.)

Certification plan for safety and PRA codes

International Nuclear Information System (INIS)

Toffer, H.; Crowe, R.D.; Ades, M.J.

1990-05-01

A certification plan for computer codes used in Safety Analyses and Probabilistic Risk Assessment (PRA) for the operation of the Savannah River Site (SRS) reactors has been prepared. An action matrix, checklists, and a time schedule have been included in the plan. These items identify what is required to achieve certification of the codes. A list of Safety Analysis and Probabilistic Risk Assessment (SA ampersand PRA) computer codes covered by the certification plan has been assembled. A description of each of the codes was provided in Reference 4. The action matrix for the configuration control plan identifies code specific requirements that need to be met to achieve the certification plan's objectives. The checklist covers the specific procedures that are required to support the configuration control effort and supplement the software life cycle procedures based on QAP 20-1 (Reference 7). A qualification checklist for users establishes the minimum prerequisites and training for achieving levels of proficiency in using configuration controlled codes for critical parameter calculations

X-ray Spectroscopy for Quality Control of Chemotherapy Drugs

International Nuclear Information System (INIS)

Greaves, E. D.; Barros, H.; Bermudez, J.; Sajo-Bohus, L.; Angeli-Greaves, M.

2007-01-01

We develop a method, employing Compton peak standardization and the use of matrix-matched spiked samples with Total Reflection X-ray Fluorescence (TXRF), for the determination of platinum plasma concentrations of patients undergoing chemotherapy with Pt-bearing drugs. Direct blood plasma analysis attains Pt detection limits of 70 ng/ml. Measurement results of prescribed drug doses are compared to achieved blood Pt concentrations indicating a lack of expected correlations. Direct analysis of Pt-containing infused drugs from a variety of suppliers indicates cases of abnormal concentrations which raises quality control issues. We demonstrate the potential usefulness of the method for pharmacokinetic studies or for routine optimization and quality control of Pt chemotherapy treatments

Aztheca Code

International Nuclear Information System (INIS)

Quezada G, S.; Espinosa P, G.; Centeno P, J.; Sanchez M, H.

2017-09-01

This paper presents the Aztheca code, which is formed by the mathematical models of neutron kinetics, power generation, heat transfer, core thermo-hydraulics, recirculation systems, dynamic pressure and level models and control system. The Aztheca code is validated with plant data, as well as with predictions from the manufacturer when the reactor operates in a stationary state. On the other hand, to demonstrate that the model is applicable during a transient, an event occurred in a nuclear power plant with a BWR reactor is selected. The plant data are compared with the results obtained with RELAP-5 and the Aztheca model. The results show that both RELAP-5 and the Aztheca code have the ability to adequately predict the behavior of the reactor. (Author)

Obtaining a radiation beam poly energy using the code Penelope 2006

International Nuclear Information System (INIS)

Andrade, Lucio das Chagas; Peixoto, Jose Guilherme Pereira

2013-01-01

Obtaining a spectrum X-ray is not a very easy task, one of the techniques used is the simulation by Monte Carlo method. The Penelope code is a code based on this method that simulates the transport of particles such as electrons, positrons and photons in different media and materials. The versions of this program in 2003 and 2006 show significant differences for facilitating the use of the code. The program allows the construction of the desired geometry and definitions of simulation parameters. (author)

ComboCoding: Combined intra-/inter-flow network coding for TCP over disruptive MANETs

Directory of Open Access Journals (Sweden)

Chien-Chia Chen

2011-07-01

Full Text Available TCP over wireless networks is challenging due to random losses and ACK interference. Although network coding schemes have been proposed to improve TCP robustness against extreme random losses, a critical problem still remains of DATA–ACK interference. To address this issue, we use inter-flow coding between DATA and ACK to reduce the number of transmissions among nodes. In addition, we also utilize a “pipeline” random linear coding scheme with adaptive redundancy to overcome high packet loss over unreliable links. The resulting coding scheme, ComboCoding, combines intra-flow and inter-flow coding to provide robust TCP transmission in disruptive wireless networks. The main contributions of our scheme are twofold; the efficient combination of random linear coding and XOR coding on bi-directional streams (DATA and ACK, and the novel redundancy control scheme that adapts to time-varying and space-varying link loss. The adaptive ComboCoding was tested on a variable hop string topology with unstable links and on a multipath MANET with dynamic topology. Simulation results show that TCP with ComboCoding delivers higher throughput than with other coding options in high loss and mobile scenarios, while introducing minimal overhead in normal operation.

DynamiX, numerical tool for design of next-generation x-ray telescopes.

Science.gov (United States)

Chauvin, Maxime; Roques, Jean-Pierre

2010-07-20

We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

DynamiX, numerical tool for design of next-generation x-ray telescopes

International Nuclear Information System (INIS)

Chauvin, Maxime; Roques, Jean-Pierre

2010-01-01

We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

DynamiX, numerical tool for design of next-generation x-ray telescopes

Energy Technology Data Exchange (ETDEWEB)

Chauvin, Maxime; Roques, Jean-Pierre

2010-07-20

We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

Monte Carlo simulation of gamma ray tomography for image reconstruction

Energy Technology Data Exchange (ETDEWEB)

Guedes, Karlos A.N.; Moura, Alex; Dantas, Carlos; Melo, Silvio; Lima, Emerson, E-mail: karlosguedes@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Meric, Ilker [University of Bergen (Norway)

2015-07-01

The Monte Carlo simulations of known density and shape object was validate with Gamma Ray Tomography in static experiments. An aluminum half-moon piece placed inside a steel pipe was the MC simulation test object that was also measured by means of gamma ray transmission. Wall effect of the steel pipe due to irradiation geometry in a single pair source-detector tomography was evaluated by comparison with theoretical data. MCNPX code requires a defined geometry to each photon trajectory which practically prevents this usage for tomography reconstruction simulation. The solution was found by writing a program in Delphi language to create input files automation code. Simulations of tomography data by automated MNCPX code were carried out and validated by experimental data. Working in this sequence the produced data needed a databank to be stored. Experimental setup used a Cesium-137 isotopic radioactive source (7.4 × 109 Bq), and NaI(Tl) scintillation detector of (51 × 51) × 10−3 m crystal size coupled to a multichannel analyzer. A stainless steel tubes of 0,154 m internal diameter, 0.014 m thickness wall. The results show that the MCNPX simulation code adapted to automated input file is useful for generating a matrix data M(θ,t), of a computerized gamma ray tomography for any known density and regular shape object. Experimental validation used RMSE from gamma ray paths and from attenuation coefficient data. (author)

Control and acquisition system of a space instrument for cosmic ray measurement

Science.gov (United States)

Prieto, M.; Martín, C.; Quesada, M.; Meziat, D.; Medina, J.; Sánchez, S.; Rodríguez-Frías, M. D.

2000-04-01

The PESCA Instrument Control and Acquisition System (PICAS) design, building and tests are presented. The purpose of the PESCA instrument is the study of the Solar Energetic Particles and the Anomalous Cosmic Rays. It is, therefore, a satellite on-board instrument. The PICAS is basically a computer, composed of a microprocessor with a memory block and a set of interfaces for the communication with the rest of the instrument and the satellite. The PICAS manages all the comunication processes with the satellite, that comprises the order reception from the ground station, and the telemetry sending, that includes scientific data and housekeeping data. By means of telecommands, the PICAS is completely controllable from the ground. The PICAS is also a reliable data acquisition system that guarantees the correct reception of the Cosmic Rays data collected in the ground.

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

Science.gov (United States)

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

2004-11-01

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

27 CFR 73.12 - What security controls must I use for identification codes and passwords?

Science.gov (United States)

2010-04-01

... Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURES AND PRACTICES ELECTRONIC SIGNATURES; ELECTRONIC SUBMISSION OF FORMS Electronic Signatures § 73.12 What security controls must I use for identification codes and passwords? If you use electronic signatures based upon use...

SolTrace: A Ray-Tracing Code for Complex Solar Optical Systems

Energy Technology Data Exchange (ETDEWEB)

Wendelin, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dobos, Aron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lewandowski, Allan [Allan Lewandowski Solar Consulting LLC, Evergreen, CO (United States)

2013-10-01

SolTrace is an optical simulation tool designed to model optical systems used in concentrating solar power (CSP) applications. The code was first written in early 2003, but has seen significant modifications and changes since its inception, including conversion from a Pascal-based software development platform to C++. SolTrace is unique in that it can model virtually any optical system utilizingthe sun as the source. It has been made available for free and as such is in use worldwide by industry, universities, and research laboratories. The fundamental design of the code is discussed, including enhancements and improvements over the earlier version. Comparisons are made with other optical modeling tools, both non-commercial and commercial in nature. Finally, modeled results are shownfor some typical CSP systems and, in one case, compared to measured optical data.

Plan for PLEX X-Ray Ablation Experiments and Analysis

Energy Technology Data Exchange (ETDEWEB)

Latkowski, J F; Reyes, S

2001-09-27

PLEX is a Z-pinch based x-ray source that can produce x-rays with fluences (0.3-18 J/cm{sup 2}), pulselengths (10-30 ns), repetition rates (<10 Hz), and energies (50-500 eV) of interest for IFE chambers and optics. It provides an affordable, dedicated method to advance our understanding of x-ray damage to materials. The PLEX x-ray source will be used to experimentally validate and further develop the ABLATOR x-ray ablation code for use in inertial fusion energy (IFE) studies.

X-ray fluorescence control of chemical composition of cast iron

International Nuclear Information System (INIS)

Prekina, I.M.; Rozova, O.F.; Loran, A.V.; Teplitskaya, G.A.; Smagunova, A.N.

1995-01-01

A method of x-ray fluorescence analysis developed for analytical set (KRF-18 diffractometer/DVK-3 computer) is used to control cast iron composition. A quantitative evaluation of errors attributed to the violation of conditions of cast iron sampling from the flow and to the quality of preparing samples for XFA is obtained. It is shown that the main component of the integral experimental error is attributed to nonuniformity of chemical composition of cast iron. Metrological studies show that reproductibility, convergence, accuracy, and sensitivity of the method match the requirements characteristic of the control process. 4 refs.; 2 tabs

LabVIEW interface with Tango control system for a multi-technique X-ray spectrometry IAEA beamline end-station at Elettra Sincrotrone Trieste

Energy Technology Data Exchange (ETDEWEB)

Wrobel, P.M. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Bogovac, M. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); Sghaier, H. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); Institut Superieur d’Informatique et de Mathematiques de Monastir (ISIMM), Departement de technologie, 5000 Monastir (Tunisia); Leani, J.J. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); IFEG – CONICET, Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina); Migliori, A.; Padilla-Alvarez, R. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); Czyzycki, M. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Osan, J. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); Environmental Physics Department, Hungarian Academy of Sciences Centre for Energy Research, Konkoly-Thege M. út 29-33., H-1121 Budapest (Hungary); Kaiser, R.B. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); and others

2016-10-11

A new synchrotron beamline end-station for multipurpose X-ray spectrometry applications has been recently commissioned and it is currently accessible by end-users at the XRF beamline of Elettra Sincrotrone Trieste. The end-station consists of an ultra-high vacuum chamber that includes as main instrument a seven-axis motorized manipulator for sample and detectors positioning, different kinds of X-ray detectors and optical cameras. The beamline end-station allows performing measurements in different X-ray spectrometry techniques such as Microscopic X-Ray Fluorescence analysis (µXRF), Total Reflection X-Ray Fluorescence analysis (TXRF), Grazing Incidence/Exit X-Ray Fluorescence analysis (GI-XRF/GE-XRF), X-Ray Reflectometry (XRR), and X-Ray Absorption Spectroscopy (XAS). A LabVIEW Graphical User Interface (GUI) bound with Tango control system consisted of many custom made software modules is utilized as a user-friendly tool for control of the entire end-station hardware components. The present work describes this advanced Tango and LabVIEW software platform that utilizes in an optimal synergistic manner the merits and functionality of these well-established programming and equipment control tools. - Highlights: • A new methodology for control of a synchrotron beamline end-station is shown. • The new control system comprises a novel binding of Tango control system with LabVIEW interface. • The reliability of the control system is demonstrated by examples of analytical applications.

Measurement of angular distribution of cosmic-ray muon fluence rate

International Nuclear Information System (INIS)

Lin, Jeng-Wei; Chen, Yen-Fu; Sheu, Rong-Jiun; Jiang, Shiang-Huei

2010-01-01

In this work a Berkeley Lab cosmic ray detector was used to measure the angular distribution of the cosmic-ray muon fluence rate. Angular response functions of the detector at each measurement orientation were calculated by using the FLUKA Monte Carlo code, where no energy attenuation was taken into account. Coincidence counting rates were measured at ten orientations with equiangular intervals. The muon angular fluence rate spectrum was unfolded from the measured counting rates associated with the angular response functions using both the MAXED code and the parameter adjusting method.

Microfocus x-ray imaging of traceable pointlike {sup 22}Na sources for quality control

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, T.; Oda, K.; Sato, Y.; Ito, H.; Masuda, S.; Yamada, T.; Matsumoto, M.; Murayama, H.; Takei, H. [Allied Health Sciences, Kitasato University Kitasato 1-15-1, Minami-ku, Sagamihara-shi, Kanagawa 252-0373 (Japan); Positron Medical Center, Tokyo Metropolitan Institute of Gerontology Sakaecho 35-2, Itabashi-ku, Tokyo 173-0015 (Japan); Advanced Industrial Science and Technology (AIST) Central 2, Umezono 1-1-1, Tsukuba-shi, Ibaraki 305-8568 (Japan); Kanagawa Industrial Technology Center (KITC) Shimoimazumi 705-1, Ebina-shi, Kanagawa 243-0435 (Japan); Japan Radioisotope Association (JRIA) Komagome 2-28-45, Bunkyo-ku, Tokyo 113-8941 (Japan); Molecular Imaging Center, National Institute of Radiological Sciences Anagawa 4-9-1, Inage, Chiba 263-8555 (Japan); Graduate School of Medical Sciences, Kitasato University Kitasato 1-15-1, Minami-ku, Sagamihara-shi, Kanagawa 252-0373 (Japan)

2012-07-15

Purpose: The purpose of this study is to propose a microfocus x-ray imaging technique for observing the internal structure of small radioactive sources and evaluating geometrical errors quantitatively, and to apply this technique to traceable pointlike {sup 22}Na sources, which were designed for positron emission tomography calibration, for the purpose of quality control of the pointlike sources. Methods: A microfocus x-ray imaging system with a focus size of 0.001 mm was used to obtain projection x-ray images and x-ray CT images of five pointlike source samples, which were manufactured during 2009-2012. The obtained projection and tomographic images were used to observe the internal structure and evaluate geometrical errors quantitatively. Monte Carlo simulation was used to evaluate the effect of possible geometrical errors on the intensity and uniformity of 0.511 MeV annihilation photon pairs emitted from the sources. Results: Geometrical errors were evaluated with sufficient precision using projection x-ray images. CT images were used for observing the internal structure intuitively. As a result, four of the five examined samples were within the tolerance to maintain the total uncertainty below {+-}0.5%, given the source radioactivity; however, one sample was found to be defective. Conclusions: This quality control procedure is crucial and offers an important basis for using the pointlike {sup 22}Na source as a basic calibration tool. The microfocus x-ray imaging approach is a promising technique for visual and quantitative evaluation of the internal geometry of small radioactive sources.

Design of the nickel-like tin x-ray laser at 12.0 nm

International Nuclear Information System (INIS)

Yan Fei; Zhang Jie; Lu Xin; Zhong, Jia Y.

2005-01-01

The effects of the drive laser intensity, pulse duration, and pulse configuration on the performance of the Ni-like Sn x-ray laser at 12.0 nm (4d→4p, J=0→1) are investigated with use of a one-dimensional hydrodynamic code coupled with an atomic physics code. High gain operation is predicted for the optimized drive pulse configuration. The effects of refraction and saturation on the propagation of the x-ray laser in the plasma medium are also investigated by use of a two-dimensional ray-tracing code. The results show that the refraction plays an important role. The saturated output with an effective gain product length of 17.88 can be obtained for an ∼0.40-cm-long plasma column by use of optimized parameters

Optomechanical design of a hard x-ray nanoprobe instrument with active vibration control in nanometer scale

International Nuclear Information System (INIS)

Shu, D.; Maser, J.; Holt, M.; Winarski, R.; Preissner, C.; Smolyanitskiy, A.; Lai, B.; Vogt, S.; Stephenson, G.

2007-01-01

We are developing a new hard x-ray nanoprobe instrument that is one of the centerpieces of the characterization facilities of the Center for Nanoscale Materials being constructed at Argonne National Laboratory. This new probe will cover an energy range of 3-30 keV with 30-nm spatial resolution. The system is designed to accommodate x-ray optics with a resolution limit of 10 nm, therefore, it requires staging of x-ray optics and specimens with a mechanical repeatability of better than 5 nm. Fast feedback for differential vibration control between the zone-plate x-ray optics and the sample holder has been implemented in the design using a digital-signal-processor-based real-time closed-loop feedback technique. A specially designed, custom-built laser Doppler displacement meter system provides two-dimensional differential displacement measurements with subnanometer resolution between the zone-plate x-ray optics and the sample holder. The optomechanical design of the instrument positioning stage system with nanometer-scale active vibration control is presented in this paper.

UNICOS CPC6: automated code generation for process control applications

International Nuclear Information System (INIS)

Fernandez Adiego, B.; Blanco Vinuela, E.; Prieto Barreiro, I.

2012-01-01

The Continuous Process Control package (CPC) is one of the components of the CERN Unified Industrial Control System framework (UNICOS). As a part of this framework, UNICOS-CPC provides a well defined library of device types, a methodology and a set of tools to design and implement industrial control applications. The new CPC version uses the software factory UNICOS Application Builder (UAB) to develop CPC applications. The CPC component is composed of several platform oriented plug-ins (PLCs and SCADA) describing the structure and the format of the generated code. It uses a resource package where both, the library of device types and the generated file syntax, are defined. The UAB core is the generic part of this software, it discovers and calls dynamically the different plug-ins and provides the required common services. In this paper the UNICOS CPC6 package is introduced. It is composed of several plug-ins: the Instance generator and the Logic generator for both, Siemens and Schneider PLCs, the SCADA generator (based on PVSS) and the CPC wizard as a dedicated plug-in created to provide the user a friendly GUI (Graphical User Interface). A tool called UAB Bootstrap will manage the different UAB components, like CPC, and its dependencies with the resource packages. This tool guides the control system developer during the installation, update and execution of the UAB components. (authors)

ETR/ITER systems code

Energy Technology Data Exchange (ETDEWEB)

Barr, W.L.; Bathke, C.G.; Brooks, J.N.; Bulmer, R.H.; Busigin, A.; DuBois, P.F.; Fenstermacher, M.E.; Fink, J.; Finn, P.A.; Galambos, J.D.; Gohar, Y.; Gorker, G.E.; Haines, J.R.; Hassanein, A.M.; Hicks, D.R.; Ho, S.K.; Kalsi, S.S.; Kalyanam, K.M.; Kerns, J.A.; Lee, J.D.; Miller, J.R.; Miller, R.L.; Myall, J.O.; Peng, Y-K.M.; Perkins, L.J.; Spampinato, P.T.; Strickler, D.J.; Thomson, S.L.; Wagner, C.E.; Willms, R.S.; Reid, R.L. (ed.)

1988-04-01

A tokamak systems code capable of modeling experimental test reactors has been developed and is described in this document. The code, named TETRA (for Tokamak Engineering Test Reactor Analysis), consists of a series of modules, each describing a tokamak system or component, controlled by an optimizer/driver. This code development was a national effort in that the modules were contributed by members of the fusion community and integrated into a code by the Fusion Engineering Design Center. The code has been checked out on the Cray computers at the National Magnetic Fusion Energy Computing Center and has satisfactorily simulated the Tokamak Ignition/Burn Experimental Reactor II (TIBER) design. A feature of this code is the ability to perform optimization studies through the use of a numerical software package, which iterates prescribed variables to satisfy a set of prescribed equations or constraints. This code will be used to perform sensitivity studies for the proposed International Thermonuclear Experimental Reactor (ITER). 22 figs., 29 tabs.

ETR/ITER systems code

International Nuclear Information System (INIS)

Barr, W.L.; Bathke, C.G.; Brooks, J.N.

1988-04-01

A tokamak systems code capable of modeling experimental test reactors has been developed and is described in this document. The code, named TETRA (for Tokamak Engineering Test Reactor Analysis), consists of a series of modules, each describing a tokamak system or component, controlled by an optimizer/driver. This code development was a national effort in that the modules were contributed by members of the fusion community and integrated into a code by the Fusion Engineering Design Center. The code has been checked out on the Cray computers at the National Magnetic Fusion Energy Computing Center and has satisfactorily simulated the Tokamak Ignition/Burn Experimental Reactor II (TIBER) design. A feature of this code is the ability to perform optimization studies through the use of a numerical software package, which iterates prescribed variables to satisfy a set of prescribed equations or constraints. This code will be used to perform sensitivity studies for the proposed International Thermonuclear Experimental Reactor (ITER). 22 figs., 29 tabs

Electromagnetic reprogrammable coding-metasurface holograms.

Science.gov (United States)

Li, Lianlin; Jun Cui, Tie; Ji, Wei; Liu, Shuo; Ding, Jun; Wan, Xiang; Bo Li, Yun; Jiang, Menghua; Qiu, Cheng-Wei; Zhang, Shuang

2017-08-04

Metasurfaces have enabled a plethora of emerging functions within an ultrathin dimension, paving way towards flat and highly integrated photonic devices. Despite the rapid progress in this area, simultaneous realization of reconfigurability, high efficiency, and full control over the phase and amplitude of scattered light is posing a great challenge. Here, we try to tackle this challenge by introducing the concept of a reprogrammable hologram based on 1-bit coding metasurfaces. The state of each unit cell of the coding metasurface can be switched between '1' and '0' by electrically controlling the loaded diodes. Our proof-of-concept experiments show that multiple desired holographic images can be realized in real time with only a single coding metasurface. The proposed reprogrammable hologram may be a key in enabling future intelligent devices with reconfigurable and programmable functionalities that may lead to advances in a variety of applications such as microscopy, display, security, data storage, and information processing.Realizing metasurfaces with reconfigurability, high efficiency, and control over phase and amplitude is a challenge. Here, Li et al. introduce a reprogrammable hologram based on a 1-bit coding metasurface, where the state of each unit cell of the coding metasurface can be switched electrically.

Study of lower hybrid wave propagation and absorption in a tokamak plasma using hard X-Ray tomography

International Nuclear Information System (INIS)

Imbeaux, F.

1999-01-01

Control of the current density profile is a critical issue in view to obtain high fusion performances in tokamak plasmas? It is therefore important to be able to control the power deposition profile of the lower hybrid wave, which has the highest current drive efficiency among all other non-inductive additional methods. Propagation and absorption of this wave are investigated in the Tore Supra tokamak using a new hard x-ray tomographic system and a new ray-tracing/Fokker-Planck code. These tools are described in detail and allow to analyse the lower hybrid power deposition profile dependence as a function of various plasma parameters (density, magnetic field, current) and of the injected wave spectrum. A good agreement between the code and the measurements found when the central electron temperature is greater than about 3 keV, that is in regimes where the wave undergoes only a few reflections before being absorbed. The simulations are then used to interpret the experimental trends. The lower hybrid power deposition profile is in nearly all discharges localised at a normalised minor radius of 0.2-0.3, and is weakly sensitive to variations of plasma parameters. It is hence difficult to perform an efficient control of the current profile generated by the lower hybrid wave in Tore Supra. This goal may nevertheless be reached by using an original method, which uses an auxiliary lower hybrid wave injected by a vertical port of the torus. This method is investigated by means of the simulation code. (author)

Distributed control and data acquisition for the EUROGAM gamma ray spectrometer

International Nuclear Information System (INIS)

Owen, E.C.G.

1992-01-01

EUROGAM is an Anglo/French Gamma Ray Detector which will alternate between the Tandem Van der Graaf at Daresbury and the Vivitron at Strasbourg. Because of the need to conform to the standards of Laboratories in two different countries, and the very sensitive nature of electronics for Germanium Gamma Ray telescopes, the newly emerging VXlbus (VMEbus EXtensions for Instrumentation) was chosen as the basis for control and data acquisition. This entailed a major programme of development for both the signal processing front end modules for Germanium and Bismuth Germanate detectors, and also for the hardware and software management of resources from within the VXI environment. The paper will concentrate mainly on the latter areas. (author)

REgolith X-Ray Imaging Spectrometer (REXIS) Aboard NASA’s OSIRIS-REx Mission

Science.gov (United States)

Hong, JaeSub; Allen, Branden; Grindlay, Jonathan E.; Binzel, Richard P.; Masterson, Rebecca; Inamdar, Niraj K; Chodas, Mark; Smith, Matthew W; Bautz, Mark W.; Kissel, Steven E; Villasenor, Jesus Noel; Oprescu, Antonia

2014-06-01

The REgolith X-Ray Imaging Spectrometer (REXIS) is a student-led instrument being designed, built, and operated as a collaborative effort involving MIT and Harvard. It is a part of NASA's OSIRIS-REx mission, which is scheduled for launch in September of 2016 for a rendezvous with, and collection of a sample from the surface of the primitive carbonaceous chondrite-like asteroid 101955 Bennu in 2019. REXIS will determine spatial variations in elemental composition of Bennu's surface through solar-induced X-ray fluorescence. REXIS consists of four X-ray CCDs in the detector plane and an X-ray mask. It is the first coded-aperture X-ray telescope in a planetary mission, which combines the benefit of high X-ray throughput of wide-field collimation with imaging capability of a coded-mask, enabling detection of elemental surface distributions at approximately 50-200 m scales. We present an overview of the REXIS instrument and the expected performance.

A point kernel shielding code, PKN-HP, for high energy proton incident

Energy Technology Data Exchange (ETDEWEB)

Kotegawa, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1996-06-01

A point kernel integral technique code PKN-HP, and the related thick target neutron yield data have been developed to calculate neutron and secondary gamma-ray dose equivalents in ordinary concrete and iron shields for fully stopping length C, Cu and U-238 target neutrons produced by 100 MeV-10 GeV proton incident in a 3-dimensional geometry. The comparisons among calculation results of the present code and other calculation techniques, and measured values showed the usefulness of the code. (author)

Programming Arduino to Control Bias Voltages to Temperature-Depedndent Gamma-ray Detectors aboard TRYAD Mission

Science.gov (United States)

Stevons, C. E.; Jenke, P.; Briggs, M. S.

2016-12-01

Terrestrial Gamma-ray Flashes (TGFs) are sub-millisecond gamma-ray flashes that are correlated with lightning have been observed with numerous satellites since their discovery in the early 1990s. Although substantial research has been conducted on TGFs, puzzling questions regarding their origin are still left unanswered. Consequently, the Terrestrial RaYs Analysis and Detection (TRYAD) mission is designed to solve many issues about TGFs by measuring the beam profile and orientation of TGFs in low Earth orbit. This project consists of sending two CubeSats into low-Earth orbit where they will independently sample TGF beams. Both of the TRYAD CubeSats will contain a gamma-ray detector composed of lead doped plastic scintillator coupled to silicon photomultiplier (SiPM) arrays. The gain readings of the SiPMs vary with temperature and the bias voltage must be corrected to compensate. Using an Arduino micro-controller, circuitry and software was developed to control the gain in response to the resistance of a thermistor. I will present the difficulties involved with this project along with our solutions.

Analysis of NEA-NSC PWR Uncontrolled Control Rod Withdrawal at Zero Power Benchmark Cases with NODAL3 Code

Directory of Open Access Journals (Sweden)

Tagor Malem Sembiring

2017-01-01

Full Text Available The in-house coupled neutronic and thermal-hydraulic (N/T-H code of BATAN (National Nuclear Energy Agency of Indonesia, NODAL3, based on the few-group neutron diffusion equation in 3-dimensional geometry using the polynomial nodal method, has been verified with static and transient PWR benchmark cases. This paper reports the verification of NODAL3 code in the NEA-NSC PWR uncontrolled control rods withdrawal at zero power benchmark. The objective of this paper is to determine the accuracy of NODAL3 code in solving the continuously slow and fast reactivity insertions due to single and group of control rod bank withdrawn while the power and temperature increment are limited by the Doppler coefficient. The benchmark is chosen since many organizations participated using various methods and approximations, so the calculation results of NODAL3 can be compared to other codes’ results. The calculated parameters are performed for the steady-state, transient core averaged, and transient hot pellet results. The influence of radial and axial nodes number was investigated for all cases. The results of NODAL3 code are in very good agreement with the reference solutions if the radial and axial nodes number is 2 × 2 and 2 × 18 (total axial layers, respectively.

Two-dimensional sensitivity calculation code: SENSETWO

International Nuclear Information System (INIS)

Yamauchi, Michinori; Nakayama, Mitsuo; Minami, Kazuyoshi; Seki, Yasushi; Iida, Hiromasa.

1979-05-01

A SENSETWO code for the calculation of cross section sensitivities with a two-dimensional model has been developed, on the basis of first order perturbation theory. It uses forward neutron and/or gamma-ray fluxes and adjoint fluxes obtained by two-dimensional discrete ordinates code TWOTRAN-II. The data and informations of cross sections, geometry, nuclide density, response functions, etc. are transmitted to SENSETWO by the dump magnetic tape made in TWOTRAN calculations. The required input for SENSETWO calculations is thus very simple. The SENSETWO yields as printed output the cross section sensitivities for each coarse mesh zone and for each energy group, as well as the plotted output of sensitivity profiles specified by the input. A special feature of the code is that it also calculates the reaction rate with the response function used as the adjoint source in TWOTRAN adjoint calculation and the calculated forward flux from the TWOTRAN forward calculation. (author)

Spectrum unfolding in X-ray spectrometry using the maximum entropy method

International Nuclear Information System (INIS)

Fernandez, Jorge E.; Scot, Viviana; Di Giulio, Eugenio

2014-01-01

The solution of the unfolding problem is an ever-present issue in X-ray spectrometry. The maximum entropy technique solves this problem by taking advantage of some known a priori physical information and by ensuring an outcome with only positive values. This method is implemented in MAXED (MAXimum Entropy Deconvolution), a software code contained in the package UMG (Unfolding with MAXED and GRAVEL) developed at PTB and distributed by NEA Data Bank. This package contains also the code GRAVEL (used to estimate the precision of the solution). This article introduces the new code UMESTRAT (Unfolding Maximum Entropy STRATegy) which applies a semi-automatic strategy to solve the unfolding problem by using a suitable combination of MAXED and GRAVEL for applications in X-ray spectrometry. Some examples of the use of UMESTRAT are shown, demonstrating its capability to remove detector artifacts from the measured spectrum consistently with the model used for the detector response function (DRF). - Highlights: ► A new strategy to solve the unfolding problem in X-ray spectrometry is presented. ► The presented strategy uses a suitable combination of the codes MAXED and GRAVEL. ► The applied strategy provides additional information on the Detector Response Function. ► The code UMESTRAT is developed to apply this new strategy in a semi-automatic mode

Uncertainties of exposure-related quantities in mammographic x-ray unit quality control

International Nuclear Information System (INIS)

Gregory, Kent J.; Pattison, John E.; Bibbo, Giovanni

2006-01-01

Breast screening programs operate in many countries with mammographic x-ray units subject to stringent quality control tests. These tests include the evaluation of quantities based on exposure measurements, such as half value layer, automatic exposure control reproducibility, average glandular dose, and radiation output rate. There are numerous error sources that contribute to the uncertainty of these exposure-related quantities, some of which are unique to the low energy x-ray spectrum produced by mammographic x-ray units. For each of these exposure-related quantities, the applicable error sources and their magnitudes vary, depending on the test equipment used to make the measurement, and whether or not relevant corrections have been applied. This study has identified and quantified a range of error sources that may be used to estimate the combined uncertainty of these exposure-related quantities, given the test equipment used and corrections applied. The uncertainty analysis uses methods described by the International Standards Organization's Guide to the Expression of Uncertainty in Measurement. Examples of how these error sources combine to give the uncertainty of the exposure-related quantities are presented. Using the best test equipment evaluated in this study, uncertainties of the four exposure-related quantities at the 95% confidence interval were found to be ±1.6% (half value layer), ±0.0008 (automatic exposure control reproducibility), ±2.3% (average glandular dose), and ±2.1% (radiation output rate). In some cases, using less precise test equipment or failing to apply corrections, resulted in uncertainties more than double in magnitude

Control code for laboratory adaptive optics teaching system

Science.gov (United States)

Jin, Moonseob; Luder, Ryan; Sanchez, Lucas; Hart, Michael

2017-09-01

By sensing and compensating wavefront aberration, adaptive optics (AO) systems have proven themselves crucial in large astronomical telescopes, retinal imaging, and holographic coherent imaging. Commercial AO systems for laboratory use are now available in the market. One such is the ThorLabs AO kit built around a Boston Micromachines deformable mirror. However, there are limitations in applying these systems to research and pedagogical projects since the software is written with limited flexibility. In this paper, we describe a MATLAB-based software suite to interface with the ThorLabs AO kit by using the MATLAB Engine API and Visual Studio. The software is designed to offer complete access to the wavefront sensor data, through the various levels of processing, to the command signals to the deformable mirror and fast steering mirror. In this way, through a MATLAB GUI, an operator can experiment with every aspect of the AO system's functioning. This is particularly valuable for tests of new control algorithms as well as to support student engagement in an academic environment. We plan to make the code freely available to the community.

(Almost) practical tree codes

KAUST Repository

Khina, Anatoly

2016-08-15

We consider the problem of stabilizing an unstable plant driven by bounded noise over a digital noisy communication link, a scenario at the heart of networked control. To stabilize such a plant, one needs real-time encoding and decoding with an error probability profile that decays exponentially with the decoding delay. The works of Schulman and Sahai over the past two decades have developed the notions of tree codes and anytime capacity, and provided the theoretical framework for studying such problems. Nonetheless, there has been little practical progress in this area due to the absence of explicit constructions of tree codes with efficient encoding and decoding algorithms. Recently, linear time-invariant tree codes were proposed to achieve the desired result under maximum-likelihood decoding. In this work, we take one more step towards practicality, by showing that these codes can be efficiently decoded using sequential decoding algorithms, up to some loss in performance (and with some practical complexity caveats). We supplement our theoretical results with numerical simulations that demonstrate the effectiveness of the decoder in a control system setting.

Simulations of Laboratory Astrophysics Experiments using the CRASH code

Science.gov (United States)

Trantham, Matthew; Kuranz, Carolyn; Fein, Jeff; Wan, Willow; Young, Rachel; Keiter, Paul; Drake, R. Paul

2015-11-01

Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, magnetized flows, jets, and laser-produced plasmas. This work is funded by the following grants: DEFC52-08NA28616, DE-NA0001840, and DE-NA0002032.

Coded aperture detector: an image sensor with sub 20-nm pixel resolution.

Science.gov (United States)

Miyakawa, Ryan; Mayer, Rafael; Wojdyla, Antoine; Vannier, Nicolas; Lesser, Ian; Aron-Dine, Shifrah; Naulleau, Patrick

2014-08-11

We describe the coded aperture detector, a novel image sensor based on uniformly redundant arrays (URAs) with customizable pixel size, resolution, and operating photon energy regime. In this sensor, a coded aperture is scanned laterally at the image plane of an optical system, and the transmitted intensity is measured by a photodiode. The image intensity is then digitally reconstructed using a simple convolution. We present results from a proof-of-principle optical prototype, demonstrating high-fidelity image sensing comparable to a CCD. A 20-nm half-pitch URA fabricated by the Center for X-ray Optics (CXRO) nano-fabrication laboratory is presented that is suitable for high-resolution image sensing at EUV and soft X-ray wavelengths.

Control of an X-ray cine radiography apparatus

International Nuclear Information System (INIS)

Nishio, K.

1982-01-01

This patent application describes an X-ray cine radiography apparatus comprising an X-ray tube, an image intensifier for converting the X-rays transmitted through an object into a visual image and a cine camera for picking up the visual image, a photomultiplier detects the brightness of the visual image to produce a brightness signal and a potentiometer detects the actual tube voltage of said X-ray tube. (author)

X-ray diagnostic installation for X-ray tomographic images

International Nuclear Information System (INIS)

Haendle, J.; Sklebitz, H.

1984-01-01

An exemplary embodiment includes at least one x-ray tube for the generation of an x-ray beam, a patient support, an image detector, and a control generator-connected with the x-ray tube and the image detector-for the purpose of moving the x-ray beam, and in opposition thereto, the image field of the image detector. There is connected to the control generator a layer height computer which calculates the enlargement from the geometric data for the tomogram. The image detector has a circuit-connected with the layer height computer-for the purpose of fading-in a marking for the dimensions in the layer plane

Course control in rheumatic arthritis by means of X-ray and scintiscanning examinations

International Nuclear Information System (INIS)

Grebe, S.F.; Dreher, R.; Hanheide, H.; Virian, M.; Faengewisch, G.L.; Mueller, H.; Altaras, J.; Federlin, K.

In contact to the X-ray examinations, the scintiscanning permits the recognition of the probable rheumatic arthritis. Furthermore, the quantitative scintiscanning values show the activity of a process and hence are a control of the therapy. This is not possible with X-rays. The latter merely show the advance of the degenerative process. The increase of the inflammation index in some cases does not always run parallel to the dose of both radiopharmaceuticals. These problems must be clarified in further investigations. (orig./AJ) [de

Transient calculation performance of the MASTER code for control rod ejection problem

International Nuclear Information System (INIS)

Cho, B. O.; Joo, H. G.; Yoo, Y. J.; Park, S. Y.; Zee, S. Q.

1999-01-01

The accuracy and the effectiveness of the solution methods of the MASTER code for reactor transient problems were analyzed with a set of NEACRP PWR control rod ejection benchmark problems. A series of sensitivity study for the effects on the solution by the neutronic solution methods and the neutronic and thermal-hydraulic model parameters were thus investigated. The MASTER results were then compared with the reference PANTHER results. This indicates that the MASTER solution is sufficiently accurate and the computing time is fast enough for nuclear design application

Transient calculation performance of the MASTER code for control rod ejection problem

Energy Technology Data Exchange (ETDEWEB)

Cho, B. O.; Joo, H. G.; Yoo, Y. J.; Park, S. Y.; Zee, S. Q. [KAERI, Taejon (Korea, Republic of)

1999-10-01

The accuracy and the effectiveness of the solution methods of the MASTER code for reactor transient problems were analyzed with a set of NEACRP PWR control rod ejection benchmark problems. A series of sensitivity study for the effects on the solution by the neutronic solution methods and the neutronic and thermal-hydraulic model parameters were thus investigated. The MASTER results were then compared with the reference PANTHER results. This indicates that the MASTER solution is sufficiently accurate and the computing time is fast enough for nuclear design application.

Cosmic Ray Background Analysis For A Cargo Container Counter

International Nuclear Information System (INIS)

Ensslin, Norbert; Geist, W.H.; Lestone, J.P.; Mayo, D.R.; Menlove, Howard O.

2001-01-01

We have developed a new model for calculating the expected yield of cosmic-ray spallation neutrons in a Cargo Container Counter, and we have benchmarked the model against measurements made with several existing large neutron counters. We also developed two versions of a new measurement uncertainty prediction code based on Microsoft Excel spreadsheets. The codes calculate the minimum detectability limit for the Cargo Container Counter for either neutron singles or doubles counting, and also propagate the uncertainties associated with efficiency normalization flux monitors and cosmic ray flux monitors. This paper will describe the physics basis for this analysis, and the results obtained for several different counter designs.

Optimal codes as Tanner codes with cyclic component codes

DEFF Research Database (Denmark)

Høholdt, Tom; Pinero, Fernando; Zeng, Peng

2014-01-01

In this article we study a class of graph codes with cyclic code component codes as affine variety codes. Within this class of Tanner codes we find some optimal binary codes. We use a particular subgraph of the point-line incidence plane of A(2,q) as the Tanner graph, and we are able to describe ...

Deficiency in Monte Carlo simulations of coupled neutron-gamma-ray fields

NARCIS (Netherlands)

Maleka, Peane P.; Maucec, Marko; de Meijer, Robert J.

2011-01-01

The deficiency in Monte Carlo simulations of coupled neutron-gamma-ray field was investigated by benchmarking two simulation codes with experimental data. Simulations showed better correspondence with the experimental data for gamma-ray transport only. In simulations, the neutron interactions with

Using a tandem ionization chamber for quality control of X-ray beams

International Nuclear Information System (INIS)

Yoshizumi, Maira T.; Caldas, Linda V.E.

2011-01-01

X-ray beam qualities are defined by both the mean energies and by the half-value layers (HVL). Many international protocols use the half-value layer and the beam voltage to characterize the X-ray beam quality. A quality control program for X-ray equipment includes the constancy check of beam qualities, i.e., the periodical verification of the half-value layer, which can be a time consumable procedure. A tandem ionization chamber, developed at Instituto de Pesquisas Energeticas e Nucleares, was used to determine the HVL and its constancy for five radiotherapy standard beam qualities. This ionization chamber is composed by two sensitive volumes with inner electrodes made of different materials: aluminum and graphite. The beam quality constancy check test was performed during two months and the maximum variation obtained was 1.24% for the radiation beam quality T-10. This result is very satisfactory according to national recommendations. (author)

All-sky x-ray ampersand gamma-ray monitor (AXGAM)

International Nuclear Information System (INIS)

Tuemer, T.O.; O'Neill, T.J.; Hurley, K.

1996-01-01

A wide field-of-view, arcsecond imaging, high energy resolution x-ray and low energy gamma ray detector is proposed for a future space mission. It is specifically designed to detect and find counterparts at other wavelengths for Gamma Ray Bursts (GRBs). Detection of GRBs require wide field-of-view (π to 2 π field-of-view) and high sensitivity. This will be achieved by using high quantum efficiency CdZnTe pixel detectors, low energy threshold (few keV) to observe larger flux levels that may be possible at lower energies and large effective area (625 to 1,000 cd) per coded aperture imaging module. Counterpart searches can only be done with ultra high angular resolution (10 to 30 arcsecond FWHM) which gives 1 to 5 arcsecond position determination especially for strong GRBs. A few arcsecond resolution error box is expected to contain only one counterpart observed at another wavelength. This will be achieved by using ultra high spatial resolution pixel detectors (50 x 50 to 100 X 100 micron) and a similar resolution coded aperture to achieve the required angular resolution. AXGAM also has two other important advantages over similar detectors: (1) excellent low energy response (> 1 keV) and (2) high energy resolution (<6% at sign 5.9 keV, <3% at sign 14 keV, <4% at sign 122 keV). The low energy range may provide important new information on their cause and the high energy resolution is expected to help in the observation and identification of emission and absorption lines in the GRB spectrum. The effective energy range is planned to be 2 to 200 keV which is exceptionally wide for such a detector. AXGAM will be built in the form of a open-quotes Bucky Ballclose quotes using a coded aperture mask in a semi geodesic dome arrangement placed over a two-dimensional, high resolution CdZnTe pixel detector array using newly developed p-i-n detector technology. The p-i-n structure decreases the electron and hole trapping effect and increases energy resolution significantly

On ray stochasticity during lower hybrid current drive in tokamaks

International Nuclear Information System (INIS)

Bizarro, J.P.; Moreau, D.

1992-08-01

A comprehensive and detailed analysis is presented on the importance of toroidally induced ray stochasticity for the modelling of lower hybrid current drive and for the dynamics of the launched power spectrum. A combined ray tracing and Fokker-Planck code is used and the injected lower hybrid power distribution in poloidal angle and in parallel wave index is accurately represented by taking into account the poloidal extent of the antenna ad by efficiently covering the full range of its radiated spectrum. The importance of the balance between the wave damping and the exponential divergence of nearby ray trajectories in determining the shape of the predicted lower hybrid power deposition profiles is emphasized. When a sufficiently large number of rays is used to densely cover the region of the launched power spectrum which is affected by stochastic effects, code predictions are shown to be stable with respect to small changes in initial conditions and plasma parameters and to be consistent with experimental data

MODLIB, library of Fortran modules for nuclear reaction codes

International Nuclear Information System (INIS)

Talou, Patrick

2006-01-01

1 - Description of program or function: ModLib is a library of Fortran (90-compatible) modules to be used in existing and future nuclear reaction codes. The development of the library is an international effort being undertaken under the auspices of the long-term Subgroup A of the OECD/NEA Working Party on Evaluation and Cooperation. The aim is to constitute a library of well-tested and well-documented pieces of codes that can be used with confidence in all our coding efforts. This effort will undoubtedly help avoid the duplication of work, and most certainly facilitate the very important inter-comparisons between existing codes. 2 - Methods: - Width f luctuations [Talou, Chadwick]: calculates width fluctuation correction factors (output) for a set of transmission coefficients (input). Three methods are available: HRTW, Moldauer, and Verbaarschot (also called GOE approach). So far, no distinction is made according to the type of the coefficients channels (particle emission, gamma-ray emission, fission). - Gamma s trength [Herman]: calculates gamma-ray transmission coefficients using a Giant Resonance formalism. - Level d ensity [Koning]: computes the Gilbert-Cameron-Ignatyuk formalism for the continuum nuclear level density. - CHECKR, FIZCON, INTER, PSYCHE, STANEF [Dunford]: these modules are used in the MODLIB project but are not included in this package. They are available from the NEA Data Bank Computer Program Service under Package Ids: CHECKR (USCD1208), FIZCON (USCD1209), INTER (USCD1212), PSYCHE (USCD1216), STANEF (USCD1218)

Neutron flux distribution inside the cylindrical core of minor excess of reactivity in the IPEN/MB-01 reactor and comparison with citation code and MCNP- 5 code

International Nuclear Information System (INIS)

Aredes, Vitor Ottoni; Bitelli, Ulysses d'Utra; Mura, Luiz Ernesto C.; Santos, Diogo Feliciano dos; Lima, Ana Cecilia de Souza

2015-01-01

This study aims to determine the distribution of thermal neutron flux in the IPEN/MB-01 nuclear reactor core assembled with cylindrical core configuration of minor excess of reactivity with 568 fuel rods (28 fuel rods in diameter). The thermal neutron flux at the positions of irradiation derive from the method of reaction rate using gold foils. The experiment consists in inserting gold activations foils with and without cadmium coverage (cadmium boxes with 0.0502 cm thickness) in several positions throughout the active core. After irradiation, activity induced by nuclear reaction rates over gold foils is assessed by gamma ray spectrometry using a high-purity germanium (HPGe) detector. Experimental results are compared to those derived from calculations performed using a three dimensional CITATION diffusion code and MCNP-5 code and a proper nuclear data library. While calculated neutron flux data shows good agreement with experimental values in regions with little disturbance in the neutron flux, also showing that in the region of the reflectors of neutrons and near the control rods, the diffusion theory is not very precise. The average value of thermal neutron flux obtained experimentally compared to the calculated value by CITATION code and MCNP-5 code respectively show a difference of 1.18% and 0.84% at a nuclear power level of 74.65 ± 3.28 % watts. The average measured value of thermal neutron flux is 4.10 10 8 ± 5.25% n/cm 2 s. (author)

Neutron flux distribution inside the cylindrical core of minor excess of reactivity in the IPEN/MB-01 reactor and comparison with citation code and MCNP- 5 code

Energy Technology Data Exchange (ETDEWEB)

Aredes, Vitor Ottoni; Bitelli, Ulysses d' Utra; Mura, Luiz Ernesto C.; Santos, Diogo Feliciano dos; Lima, Ana Cecilia de Souza, E-mail: ubitelli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

This study aims to determine the distribution of thermal neutron flux in the IPEN/MB-01 nuclear reactor core assembled with cylindrical core configuration of minor excess of reactivity with 568 fuel rods (28 fuel rods in diameter). The thermal neutron flux at the positions of irradiation derive from the method of reaction rate using gold foils. The experiment consists in inserting gold activations foils with and without cadmium coverage (cadmium boxes with 0.0502 cm thickness) in several positions throughout the active core. After irradiation, activity induced by nuclear reaction rates over gold foils is assessed by gamma ray spectrometry using a high-purity germanium (HPGe) detector. Experimental results are compared to those derived from calculations performed using a three dimensional CITATION diffusion code and MCNP-5 code and a proper nuclear data library. While calculated neutron flux data shows good agreement with experimental values in regions with little disturbance in the neutron flux, also showing that in the region of the reflectors of neutrons and near the control rods, the diffusion theory is not very precise. The average value of thermal neutron flux obtained experimentally compared to the calculated value by CITATION code and MCNP-5 code respectively show a difference of 1.18% and 0.84% at a nuclear power level of 74.65 ± 3.28 % watts. The average measured value of thermal neutron flux is 4.10 10{sup 8} ± 5.25% n/cm{sup 2}s. (author)

Coded Splitting Tree Protocols

DEFF Research Database (Denmark)

Sørensen, Jesper Hemming; Stefanovic, Cedomir; Popovski, Petar

2013-01-01

This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree splitting protocol are initiated, each...... instance is terminated prematurely and subsequently iterated. The combined set of leaves from all the tree instances can then be viewed as a graph code, which is decodable using belief propagation. The main design problem is determining the order of splitting, which enables successful decoding as early...

Development of the ANL plant dynamics code and control strategies for the supercritical carbon dioxide Brayton cycle and code validation with data from the Sandia small-scale supercritical carbon dioxide Brayton cycle test loop.

Energy Technology Data Exchange (ETDEWEB)

Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

2011-11-07

Significant progress has been made in the ongoing development of the Argonne National Laboratory (ANL) Plant Dynamics Code (PDC), the ongoing investigation and development of control strategies, and the analysis of system transient behavior for supercritical carbon dioxide (S-CO{sub 2}) Brayton cycles. Several code modifications have been introduced during FY2011 to extend the range of applicability of the PDC and to improve its calculational stability and speed. A new and innovative approach was developed to couple the Plant Dynamics Code for S-CO{sub 2} cycle calculations with SAS4A/SASSYS-1 Liquid Metal Reactor Code System calculations for the transient system level behavior on the reactor side of a Sodium-Cooled Fast Reactor (SFR) or Lead-Cooled Fast Reactor (LFR). The new code system allows use of the full capabilities of both codes such that whole-plant transients can now be simulated without additional user interaction. Several other code modifications, including the introduction of compressor surge control, a new approach for determining the solution time step for efficient computational speed, an updated treatment of S-CO{sub 2} cycle flow mergers and splits, a modified enthalpy equation to improve the treatment of negative flow, and a revised solution of the reactor heat exchanger (RHX) equations coupling the S-CO{sub 2} cycle to the reactor, were introduced to the PDC in FY2011. All of these modifications have improved the code computational stability and computational speed, while not significantly affecting the results of transient calculations. The improved PDC was used to continue the investigation of S-CO{sub 2} cycle control and transient behavior. The coupled PDC-SAS4A/SASSYS-1 code capability was used to study the dynamic characteristics of a S-CO{sub 2} cycle coupled to a SFR plant. Cycle control was investigated in terms of the ability of the cycle to respond to a linear reduction in the electrical grid demand from 100% to 0% at a rate of 5

RELAP5/MOD3 code manual: Code structure, system models, and solution methods. Volume 1

International Nuclear Information System (INIS)

1995-08-01

The RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents, and operational transients, such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling, approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems. RELAP5/MOD3 code documentation is divided into seven volumes: Volume I provides modeling theory and associated numerical schemes

3D Scan-Based Wavelet Transform and Quality Control for Video Coding

Directory of Open Access Journals (Sweden)

Parisot Christophe

2003-01-01

Full Text Available Wavelet coding has been shown to achieve better compression than DCT coding and moreover allows scalability. 2D DWT can be easily extended to 3D and thus applied to video coding. However, 3D subband coding of video suffers from two drawbacks. The first is the amount of memory required for coding large 3D blocks; the second is the lack of temporal quality due to the sequence temporal splitting. In fact, 3D block-based video coders produce jerks. They appear at blocks temporal borders during video playback. In this paper, we propose a new temporal scan-based wavelet transform method for video coding combining the advantages of wavelet coding (performance, scalability with acceptable reduced memory requirements, no additional CPU complexity, and avoiding jerks. We also propose an efficient quality allocation procedure to ensure a constant quality over time.

Verification of ONED90 code

International Nuclear Information System (INIS)

Chang, Jong Hwa; Lee, Ki Bog; Zee, Sung Kyun; Lee, Chang Ho

1993-12-01

ONED90 developed by KAERI is a 1-dimensional 2-group diffusion theory code. For nuclear design and reactor simulation, the usage of ONED90 encompasses core follow calculation, load follow calculation, plant power control simulation, xenon oscillation simulation and control rod maneuvering, etc. In order to verify the validity of ONED90 code, two well-known benchmark problems are solved by ONED90 shows very similar result to reference solution. (Author) 11 refs., 5 figs., 13 tabs

A manual to the MAXRAY program library for reflective and dispersive ray tracing

International Nuclear Information System (INIS)

Svensson, S.; Nyholm, R.

1985-07-01

A general ray tracing program package for reflective and dispersive X-ray optics is described. The package consists of a number of subroutines written in FORTRAN 77 code giving the necessary tools for ray tracing. The program package is available on request from the authors. (authors)

X-Ray, EUV, UV and Optical Emissivities of Astrophysical Plasmas

Science.gov (United States)

Raymond, John C.; West, Donald (Technical Monitor)

2000-01-01

This grant primarily covered the development of the thermal X-ray emission model code called APEC, which is meant to replace the Raymond and Smith (1977) code. The new code contains far more spectral lines and a great deal of updated atomic data. The code is now available (http://hea-www.harvard.edu/APEC), though new atomic data is still being added, particularly at longer wavelengths. While initial development of the code was funded by this grant, current work is carried on by N. Brickhouse, R. Smith and D. Liedahl under separate funding. Over the last five years, the grant has provided salary support for N. Brickhouse, R. Smith, a summer student (L. McAllister), an SAO predoctoral fellow (A. Vasquez), and visits by T. Kallman, D. Liedahl, P. Ghavamian, J.M. Laming, J. Li, P. Okeke, and M. Martos. In addition to the code development, the grant supported investigations into X-ray and UV spectral diagnostics as applied to shock waves in the ISM, accreting black holes and white dwarfs, and stellar coronae. Many of these efforts are continuing. Closely related work on the shock waves and coronal mass ejections in the solar corona has grown out of the efforts supported by the grant.

An improved version of the HULLAC code

Energy Technology Data Exchange (ETDEWEB)

Busquet, M.; Bar-Shalom, A.; Klapisch, M.; Oreg, J. [ARTEPARTEP is a contractor to the Naval Research Lab., Washington, DC (United States)

2006-06-15

Accurate and detailed atomic structure codes are needed for simulation of spectrally resolved X-ray output of laser driven target. As such, the HULLAC code has already been presented several times. First of all, an overhaul was performed, modernizing many parts to make them easier to understand and adding many comments. The source, in Fortran-77, was compiled and checked on many different systems with different compilers. In the new version, we have added the possibility to directly compute the relativistic configuration averages, skipping the fine structure. However in this case configuration interactions can be accounted for only within each non-relativistic configuration. Therefore we added the possibility of a mixed description, where not all configurations are described at the fine structure level. Recently, cooperation was proposed to anyone interested in extending or developing the code. HULLAC is now ready to be distributed on a basis of collaboration.

An improved version of the HULLAC code

International Nuclear Information System (INIS)

Busquet, M.; Bar-Shalom, A.; Klapisch, M.; Oreg, J.

2006-01-01

Accurate and detailed atomic structure codes are needed for simulation of spectrally resolved X-ray output of laser driven target. As such, the HULLAC code has already been presented several times. First of all, an overhaul was performed, modernizing many parts to make them easier to understand and adding many comments. The source, in Fortran-77, was compiled and checked on many different systems with different compilers. In the new version, we have added the possibility to directly compute the relativistic configuration averages, skipping the fine structure. However in this case configuration interactions can be accounted for only within each non-relativistic configuration. Therefore we added the possibility of a mixed description, where not all configurations are described at the fine structure level. Recently, cooperation was proposed to anyone interested in extending or developing the code. HULLAC is now ready to be distributed on a basis of collaboration

Development of plant dynamic analysis code for integrated self-pressurized water reactor (ISPDYN), and comparative study of pressure control methods

International Nuclear Information System (INIS)

Kusunoki, Tsuyoshi; Yokomura, Takeyoshi; Nabeshima, Kunihiko; Shimazaki, Junya; Shinohara, Yoshikuni.

1988-01-01

This report describes the development of plant dynamic analysis code (ISPDYN) for integrated self-pressurized water reactor, and comparative study of pressure control methods with this code. ISPDYN is developed for integrated self-pressurized water reactor, one of the trial design by JAERI. In the transient responses, the calculated results by ISPDYN are in good agreement with the DRUCK calculations. In addition, this report presents some sensitivity studies for selected cases. Computing time of this code is very short so as about one fifth of real time. The comparative study of self-pressurized system with forced-pressurized system by this code, for rapid load decrease and increase cases, has provided useful informations. (author)

Wire array z-pinch insights for high X-ray power generation

International Nuclear Information System (INIS)

Sanford, T.W.L.; Marder, B.M.; Desjarlais, M.P.

1998-01-01

The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn and Z. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X-ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays

Wire array z-pinch insights for high X-ray power generation

Energy Technology Data Exchange (ETDEWEB)

Sanford, T.W.L.; Marder, B.M.; Desjarlais, M.P. [and others

1998-12-31

The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn and Z. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X-ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays.

Wire array z-pinch insights for high x-ray power generation

Energy Technology Data Exchange (ETDEWEB)

Sanford, T.W.L.; Mock, R.C.; Marder, B.M. [and others

1997-12-31

The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn and Z. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X-ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays.

Wire array z-pinch insights for high x-ray power generation

Energy Technology Data Exchange (ETDEWEB)

Sanford, T.W.L.; Mock, R.C.; Nash, T.J. [and others

1998-08-01

The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X=ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays.

Wire array z-pinch insights for high x-ray power generation

International Nuclear Information System (INIS)

Sanford, T.W.L.; Mock, R.C.; Marder, B.M.

1998-08-01

The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn and Z. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X=ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays

Analysis of the burnup of the control rods with the COREMASTER-Presto code

International Nuclear Information System (INIS)

Hernandez, J.L.; Alonso, G.; Perusquia, R.; Montes, J.L.; Hernandez, H.

2003-01-01

An evaluation of the capacity of the COREMASTER-Presto code, to evaluate generically the burnt of the control bars in the Laguna Verde reactors plant (CLV) is made. It was found that the code only reports burnt values of the control rods in MWD/TM, in spite of having with a second order polynomial model, for the conversion to remainder of the Boron-10 (B-10). It was observed that said model is adequate only for burnt smaller to 45,000 MWD/TM. To evaluate the burnt of the control rods it was reproduced the balance cycle of 18 months for the CLV, executing Cm-Presto during 13 consecutive cycles. First without rod burnt, taking this as the base case. Later on, cases with 1, 2 and up to 13 cycles with rod burnt were generated. When comparing results it was observed that the control rods pattern it loses reactivity lineally with the burnt one. By each 10 G Wd/T of burnt of the nucleus it is decreased the reactivity of the pattern rods ∼ 1 pcm in hot condition and of ∼ 20 pcm in cold condition. When burning three cycles those rods more burnt reached the 13,900 MWD/TM, equivalent to 36% of B-10 reduction, near value to 34% proposed by aging in the one lost study of B-10. It was observed that Cm-Presto it doesn't burn the superior node of the control rods when these are completely extracted. A one big lost of B-10, of the order of 50%, it represents only a decrease of 11% of the reactivity value of the rod. One can affirm that even when it is strongly decreased the content of B-10, the rod is continue considering as a black absorber, that is to say, thermal neutron that enters in the neutron rod that is absorbed. (Author)

Calibrating the Regolith X-ray Imaging Spectrometer (REXIS)

OpenAIRE

McIntosh, Missy; Hong, Jaesub; Allen, Branden; Grindlay, Jonathan

2014-01-01

This paper describes the onboard calibration process of REXIS (the Regolith X-ray Imaging Spectrometer), an instrument on OSIRIS-REx. OSIRIS-REx, scheduled to be launched in 2016, is a planetary mission intending to return a regolith sample from a near Earth asteroid called Bennu. REXIS, a student-led collaboration between Harvard and MIT, is a soft X-ray (0.5-7.5 keV) coded-aperture telescope with four X-ray CCDs and a gold coated stainless steel mask. REXIS will measure the surface elementa...

Solar Proton Transport Within an ICRU Sphere Surrounded by a Complex Shield: Ray-trace Geometry

Science.gov (United States)

Slaba, Tony C.; Wilson, John W.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

2015-01-01

A computationally efficient 3DHZETRN code with enhanced neutron and light ion (Z is less than or equal to 2) propagation was recently developed for complex, inhomogeneous shield geometry described by combinatorial objects. Comparisons were made between 3DHZETRN results and Monte Carlo (MC) simulations at locations within the combinatorial geometry, and it was shown that 3DHZETRN agrees with the MC codes to the extent they agree with each other. In the present report, the 3DHZETRN code is extended to enable analysis in ray-trace geometry. This latest extension enables the code to be used within current engineering design practices utilizing fully detailed vehicle and habitat geometries. Through convergence testing, it is shown that fidelity in an actual shield geometry can be maintained in the discrete ray-trace description by systematically increasing the number of discrete rays used. It is also shown that this fidelity is carried into transport procedures and resulting exposure quantities without sacrificing computational efficiency.

A special ionisation chamber for quality control of diagnostic and mammography X ray equipment

International Nuclear Information System (INIS)

Costa, A.M.; Caldas, L.V.E.

2003-01-01

A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy responses of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities. (author)

A special ionisation chamber for quality control of diagnostic and mammography X ray equipment.

Science.gov (United States)

Costa, A M; Caldas, L V E

2003-01-01

A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy response of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities.

Function and Application Areas in Medicine of Non-Coding RNA

Directory of Open Access Journals (Sweden)

Figen Guzelgul

2009-06-01

Full Text Available RNA is the genetic material converting the genetic code that it gets from DNA into protein. While less than 2 % of RNA is converted into protein , more than 98 % of it can not be converted into protein and named as non-coding RNAs. 70 % of noncoding RNAs consists of introns , however, the rest part of them consists of exons. Non-coding RNAs are examined in two classes according to their size and functions. Whereas they are classified as long non-coding and small non-coding RNAs according to their size , they are grouped as housekeeping non-coding RNAs and regulating non-coding RNAs according to their function. For long years ,these non-coding RNAs have been considered as non-functional. However, today, it has been proved that these non-coding RNAs play role in regulating genes and in structural, functional and catalitic roles of RNAs converted into protein. Due to its taking a role in gene silencing mechanism, particularly in medical world , non-coding RNAs have led to significant developments. RNAi technolgy , which is used in designing drugs to be used in treatment of various diseases , is a ray of hope for medical world. [Archives Medical Review Journal 2009; 18(3.000: 141-155

The elimination of ray tracing in Monte Carlo shielding programs

International Nuclear Information System (INIS)

Bendall, D.E.

1988-01-01

The MONK6 code has clearly demonstrated the advantages of hole tracking, which was devised by Woodcock et at. for use in criticality codes from earlier work by Von Neumann. Hole tracking eliminates ray tracing by introducing, for all materials present in the problem, a pseudo scattering reaction that forward scatters without energy loss. The cross section for this reaction is chosen so that the total cross sections for all the materials are equal at a given energy. By this means, tracking takes place with a constant total cross section everywhere, so there is now no need to ray trace. The present work extends hole tracking to shielding codes, where it functions in tandem with Russian roulette and splitting. An algorithm has been evolved and its performance is compared with the ray-tracking code McBEND. A disadvantage with hole tracking occurs when there is a wide variation in total cross section for materials present. As the tracking uses the total cross section of the material that has the maximum cross section, there can be a large number of pseudo collisions in the materials with low total cross sections. In extreme cases, the advantages of hole tracking can be lost by the by the extra time taken in servicing these pseudo collisions; however, techniques for eliminating this problem are under consideration

Improvement of air transport data and wall transmission/reflection data in the SKYSHINE code. (1) Calculation of line beam response function for gamma-ray skyshine analysis

Energy Technology Data Exchange (ETDEWEB)

Nemoto, Makoto [Visible Information Center, Tokai, Ibaraki (Japan); Harima, Yoshiko; Ishikawa, Satoshi [CRC Research Inst. Inc., Tokyo (Japan); Hirayama, Hideo [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Hayashi, Katsumi; Tayama, Ryuichi [Hitachi Engineering Co. Ltd., Ibaraki (Japan); Hayashida, Yoshihisa [Toshiba Corp., Yokohama, Kanagawa (Japan); Sato, Osamu [Mitsubishi Research Inst., Tokyo (Japan)

2000-03-01

The line-beam response functions (LBRFs) of a key component of a computationally simple gamma-ray skyshine analysis are generated using an electron-photon cascade Monte Carlo code EGS4. The LBRFs R(E{sub 0}, {phi}, x) are given with the air-kerma (Gy per photon), 7 photon source energies ranging from 0.5 to 10 MeV, for source-detector distances between 10 and 2,000 meters, and at 19 emission angles from 0 - 170 degrees, as measured from the source-detector axis. Especially, the values of R(E{sub 0}, {phi}=0.0 and 0.1, x) are extremely larger than the ones of LBRFs produced by the point kernel model or the COHORT code. The LBRF is accurately approximated by a four-parameter formula. Values of four parameters for the approximate LBRF are described by monotonic and smooth curves with respect to the energy E{sub 0} and the emitted angle {phi}. (author)

Analyze for the Quality Control of General X-ray Systems in Capital region

International Nuclear Information System (INIS)

Kang, Byung Sam; Lee, Kang Min; Shin, Woo Yong; Park, Soon Chul; Choi, Hak Dong; Cho, Yong Kwon

2012-01-01

Thanks to the rapid increase of the interest in the quality control of the General X-ray systems, this research proposes the direction of the quality control through comparing and inspecting the actual condition of the respective quality control in the Clinic, the educational institution and the hospital. The subjects of the investigation are diagnostic radiation equipment's in the clinic, the educational institution and the hospital around the capital. A test of kVp, mR/mAs out put test and reproducibility of the exposure dose, half value layer, an accordance between the light field and the beam alignment test, and lastly reproducibility of the exposure time. Then the mean difference of the percentage, the CV (Coefficient of Variation, CV) and the attenuated curve which are respectively resulted from the above tests are computed. After that we have evaluated the values according to the regulations on the Diagnostic Radiation Equipment Safety Administration regulations. In the case of the clinic and the educational institution, there were 22 general X-ray devices. And 18.2% of the kVp test, 13.6% of the reproducibility of exposure dose test, 9.1% of the mR/mAs out put test, and 13.6% of the HVL (Half Value Layer) test appeared to be improper. In the case of the hospital, however, there were 28 devices. And 7.1% of the reproducibility of exposure dose, 7.1% of the difference in the light field/ beam alignment, and 7.1% of the reproducibility of the exposure time appeared to be improper. According to the investigation, the hospital's quality control condition is better than the condition in the clinic and the educational institution. The quality control condition of the general X-ray devices in the clinic is unsatisfactory compared to the hospital. Thus, it is considered that realizing the importance of the quality control is necessary.

Comparison of MCNP4C and experimental results on neutron and gamma ray shielding effects for materials

Energy Technology Data Exchange (ETDEWEB)

Cha, Kyoon Ho; Lee, Eun Ki [KEPRI, Taejon (Korea, Republic of)

2004-07-01

MCNP code is a general-purpose Monte Carlo radiation transport code that can numerically simulate neutron, photon, and electron transport. Increasing the speed of computing machine is making numerical transport simulation more attractive and has led to the widespread use of such code. This code can be used for general radiation shielding and criticality accident alarm system related dose calculations, so that the version 4C2 of this code was used to evaluate the shielding effect against neutron and gamma ray experiments. The Ueki experiments were used for neutron shielding effects for materials, and the Kansas State University (KSU) photon skyshine experiments of 1977 were tested for gamma ray shielding effects.

Compliance and quality control monitoring of diagnostic X-ray facilities in Dar es Salaam city, Tanzania

Energy Technology Data Exchange (ETDEWEB)

Nkuba, Leonid L.; Nyanda, Pendo B., E-mail: leonid.nkuba@taec.or.tz [Tanzania Atomic Energy Commission, Radiation Control Directorate, Dar es Salaam (Tanzania, United Republic of)

2017-09-01

The compliance evaluation and quality control measurements on 60 diagnostic X-ray units were performed. The results on legal compliance show that 25 % of X-ray facilities operated without or with an expired license. The rest of the centers were new and had already applied for license and others had valid licenses. For basic requirements compliance, 47 % of X-ray facilities did not have the changing cubicles, 37 % of X-ray facilities did not post radiation warning sign and symbols also 46 % of units were found either without protective gear or operated by unqualified personnel. The QC test results showed that 93 % had X-ray tube voltage within the tolerance limit of 10 % and HVL ≥ 2.3 mmAl, at 80 kV was observed in 98.2 % of the units, whereas 98 % of exposure had acceptable kV reproducibility within the tolerance limit of 5 %. Of the X-ray generators assessed, 93 % had tolerable mAs linearity. 93 % and 97 % had acceptable beam alignment and light beam diaphragm. Of the assessed units, 13 (93 %) had tube leakage < 1000 μGy/hr at 1m. For shielding tests, 47 % of units had radiation levels above 0.5 μSv/hr at the main door leading to the X-ray rooms and the registration area. The dose rates > 10 μSv/hr were recorded at viewing windows, walls and doors of control cubicles and behind the doors of changing cubicles. These dose rates indicating higher health risk to workers and member of public. (author)

Controlled quantum secure direct communication using a non-symmetric quantum channel with quantum superdense coding

International Nuclear Information System (INIS)

Xia, Yan; Song, He-Shan

2007-01-01

We present a controlled quantum secure direct communication protocol that uses a 2-dimensional Greenberger-Horne-Zeilinger (GHZ) entangled state and a 3-dimensional Bell-basis state and employs the high-dimensional quantum superdense coding, local collective unitary operations and entanglement swapping. The proposed protocol is secure and of high source capacity. It can effectively protect the communication against a destroying-travel-qubit-type attack. With this protocol, the information transmission is greatly increased. This protocol can also be modified, so that it can be used in a multi-party control system

Technology Needs for Gamma Ray Astronomy

Science.gov (United States)

Gehrels, Neil

2011-01-01

Gamma ray astronomy is currently in an exciting period of multiple missions and a wealth of data. Results from INTEGRAL, Fermi, AGILE, Suzaku and Swift are making large contributions to our knowledge of high energy processes in the universe. The advances are due to new detector and imaging technologies. The steps to date have been from scintillators to solid state detectors for sensors and from light buckets to coded aperture masks and pair telescopes for imagers. A key direction for the future is toward focusing telescopes pushing into the hard X-ray regime and Compton telescopes and pair telescopes with fine spatial resolution for medium and high energy gamma rays. These technologies will provide finer imaging of gamma-ray sources. Importantly, they will also enable large steps forward in sensitivity by reducing background.

Benchmark studies of BOUT++ code and TPSMBI code on neutral transport during SMBI

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.H. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China); Wang, Z.H., E-mail: zhwang@swip.ac.cn [Southwestern Institute of Physics, Chengdu 610041 (China); Guo, W., E-mail: wfguo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China); Ren, Q.L. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Sun, A.P.; Xu, M.; Wang, A.K. [Southwestern Institute of Physics, Chengdu 610041 (China); Xiang, N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China)

2017-06-09

SMBI (supersonic molecule beam injection) plays an important role in tokamak plasma fuelling, density control and ELM mitigation in magnetic confinement plasma physics, which has been widely used in many tokamaks. The trans-neut module of BOUT++ code is the only large-scale parallel 3D fluid code used to simulate the SMBI fueling process, while the TPSMBI (transport of supersonic molecule beam injection) code is a recent developed 1D fluid code of SMBI. In order to find a method to increase SMBI fueling efficiency in H-mode plasma, especially for ITER, it is significant to first verify the codes. The benchmark study between the trans-neut module of BOUT++ code and the TPSMBI code on radial transport dynamics of neutral during SMBI has been first successfully achieved in both slab and cylindrical coordinates. The simulation results from the trans-neut module of BOUT++ code and TPSMBI code are consistent very well with each other. Different upwind schemes have been compared to deal with the sharp gradient front region during the inward propagation of SMBI for the code stability. The influence of the WENO3 (weighted essentially non-oscillatory) and the third order upwind schemes on the benchmark results has also been discussed. - Highlights: • A 1D model of SMBI has developed. • Benchmarks of BOUT++ and TPSMBI codes have first been finished. • The influence of the WENO3 and the third order upwind schemes on the benchmark results has also been discussed.

A controlled evaluation of case clinical effect coding by poison center specialists for detection of WMD scenarios.

Science.gov (United States)

Beuhler, Michael C; Wittler, Mary A; Ford, Marsha; Dulaney, Anna R

2011-08-01

Many public health entities employ computer-based syndromic surveillance to monitor for aberrations including possible exposures to weapons of mass destruction (WMD). Often, this is done by screening signs and symptoms reported for cases against syndromic definitions. Poison centers (PCs) may offer significant contributions to public health surveillance because of their detailed clinical effect data field coding and real-time data entry. Because improper clinical effect coding may impede syndromic surveillance, it is important to assess this accuracy for PCs. An AAPCC-certified regional PC assessed the accuracy of clinical effect coding by specialists in poison information (SPIs) listening to audio recordings of standard cases. Eighteen different standardized cases were used, consisting of six cyanide, six botulism, and six control cases. Cases were scripted to simulate clinically relevant telephone conversations and converted to audio recordings. Ten SPIs were randomly selected from the center's staff to listen to and code case information from the recorded cases. Kappa scores and the percentage of correctly coding a present clinical effect were calculated for individual clinical effects summed over all test cases along with corresponding 95% confidence intervals. The rate of the case coding by the SPIs triggering the PC's automated botulism and cyanide alerts was also determined. The kappa scores and the percentage of correctly coding a present clinical effect varied depending on the specific clinical effect, with greater accuracy observed for the clinical effects of vomiting and agitation/irritability, and poor accuracy observed for the clinical effects of visual defect and anion gap increase. Lack of correct coding resulted in only 60 and 86% of the cases that met the botulism and cyanide surveillance definitions, respectively, triggering the corresponding alert. There was no difference observed in the percentage of coding a present clinical effect between

Quality control of aluminium casting: X ray radiography or tomography?

International Nuclear Information System (INIS)

Munier, B.; Tamziti, J.; Grignard, A.; Peix, G.; Kaftandjian, V.

2007-01-01

Full text of publication follows: X ray radiography has been for years a well known method commonly used for controlling parts either on line or off line. The purpose is to detect internal defects or to achieve reverse engineering on the parts. More recently two-dimensional or three-dimensional Computed Tomography has been introduced and provides key advantages over standard X ray radiography, such as dimensional measurement of complex objects with hidden structures and 3D defect localisation. However, from the user point of view, despite the clear advantages of tomography, the time consuming drawback is predominant, and thus, it is worth assessing the added value of tomography with respect to several radioscopic images. It is clear that there is no unique response to that question. If unacceptable defects are already detected in one radioscopic image, then the sample can be rejected and 3D tomography is useless. On another hand, 3D tomography cannot be replaced if internal structures such as holes must be measured with accuracy. The paper will present a comparison between radiography and tomography for controlling parts in the aluminium casting industry. Advantages and drawbacks of both methods will be reviewed. Performance features in both cases will be assessed in this specific industrial case by estimating the defect detection efficiency and image quality parameters. (authors)

Instrument for x-ray absorption spectroscopy with in situ electrical control characterizations

International Nuclear Information System (INIS)

Huang, Chun-Chao; Chang, Shu-Jui; Yang, Chao-Yao; Tseng, Yuan-Chieh; Chou, Hsiung

2013-01-01

We report a synchrotron-based setup capable of performing x-ray absorption spectroscopy and x-ray magnetic circular dichroism with simultaneous electrical control characterizations. The setup can enable research concerning electrical transport, element- and orbital-selective magnetization with an in situ fashion. It is a unique approach to the real-time change of spin-polarized electronic state of a material/device exhibiting magneto-electric responses. The performance of the setup was tested by probing the spin-polarized states of cobalt and oxygen of Zn 1-x Co x O dilute magnetic semiconductor under applied voltages, both at low (∼20 K) and room temperatures, and signal variations upon the change of applied voltage were clearly detected

A broad band X-ray imaging spectrophotometer for astrophysical studies

Science.gov (United States)

Lum, Kenneth S. K.; Lee, Dong Hwan; Ku, William H.-M.

1988-01-01

A broadband X-ray imaging spectrophotometer (BBXRIS) has been built for astrophysical studies. The BBXRIS is based on a large-imaging gas scintillation proportional counter (LIGSPC), a combination of a gas scintillation proportional counter and a multiwire proportional counter, which achieves 8 percent (FWHM) energy resolution and 1.5-mm (FWHM) spatial resolution at 5.9 keV. The LIGSPC can be integrated with a grazing incidence mirror and a coded aperture mask to provide imaging over a broad range of X-ray energies. The results of tests involving the LIGSPC and a coded aperture mask are presented, and possible applications of the BBXRIS are discussed.

The MCNP simulation of the X-ray leakage of X-ray security inspection equipment

International Nuclear Information System (INIS)

Wang Kai; Liu Bin; Hu Wenchao; Zhao Wei

2011-01-01

Objective: To simulate the radiation leakage of the X-ray security inspection equipment used in the subways stations. Methods: We use the MCNP4C code to simulate the X-ray leakage of the equipment during the working process. Result: the biggest amount of radiation received by the body is 8.26 μSv/a, however, if the Lead screens of the X-ray security equipment is intact, the amount of radiation received by the body is only 0.0727 μSv/a. The final. Conclusions: When the baggage get in /out the X-ray security inspection equipment, the gas in Lead screens was made, and then the amount of radiation received by human body increased; The amount of radiation received by the body is close to but still below 10 μSv/a which is the exemption criteria set by the 'safety of radiation sources of ionizing radiation protection and basic standards'(GB18871-2002). (authors)

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ...

SAVLOC, computer program for automatic control and analysis of X-ray fluorescence experiments

Science.gov (United States)

Leonard, R. F.

1977-01-01

A program for a PDP-15 computer is presented which provides for control and analysis of trace element determinations by using X-ray fluorescence. The program simultaneously handles data accumulation for one sample and analysis of data from previous samples. Data accumulation consists of sample changing, timing, and data storage. Analysis requires the locating of peaks in X-ray spectra, determination of intensities of peaks, identification of origins of peaks, and determination of a real density of the element responsible for each peak. The program may be run in either a manual (supervised) mode or an automatic (unsupervised) mode.

TIM, a ray-tracing program for METATOY research and its dissemination

Science.gov (United States)

Lambert, Dean; Hamilton, Alasdair C.; Constable, George; Snehanshu, Harsh; Talati, Sharvil; Courtial, Johannes

2012-03-01

TIM (The Interactive METATOY) is a ray-tracing program specifically tailored towards our research in METATOYs, which are optical components that appear to be able to create wave-optically forbidden light-ray fields. For this reason, TIM possesses features not found in other ray-tracing programs. TIM can either be used interactively or by modifying the openly available source code; in both cases, it can easily be run as an applet embedded in a web page. Here we describe the basic structure of TIM's source code and how to extend it, and we give examples of how we have used TIM in our own research. Program summaryProgram title: TIM Catalogue identifier: AEKY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License No. of lines in distributed program, including test data, etc.: 124 478 No. of bytes in distributed program, including test data, etc.: 4 120 052 Distribution format: tar.gz Programming language: Java Computer: Any computer capable of running the Java Virtual Machine (JVM) 1.6 Operating system: Any; developed under Mac OS X Version 10.6 RAM: Typically 145 MB (interactive version running under Mac OS X Version 10.6) Classification: 14, 18 External routines: JAMA [1] (source code included) Nature of problem: Visualisation of scenes that include scene objects that create wave-optically forbidden light-ray fields. Solution method: Ray tracing. Unusual features: Specifically designed to visualise wave-optically forbidden light-ray fields; can visualise ray trajectories; can visualise geometric optic transformations; can create anaglyphs (for viewing with coloured "3D glasses") and random-dot autostereograms of the scene; integrable into web pages. Running time: Problem-dependent; typically seconds for a simple scene.

Completion time reduction in instantly decodable network coding through decoding delay control

KAUST Repository

Douik, Ahmed S.; Sorour, Sameh; Alouini, Mohamed-Slim; Al-Naffouri, Tareq Y.

2014-01-01

For several years, the completion time and the decoding delay problems in Instantly Decodable Network Coding (IDNC) were considered separately and were thought to completely act against each other. Recently, some works aimed to balance the effects of these two important IDNC metrics but none of them studied a further optimization of one by controlling the other. In this paper, we study the effect of controlling the decoding delay to reduce the completion time below its currently best known solution. We first derive the decoding-delay-dependent expressions of the users' and their overall completion times. Although using such expressions to find the optimal overall completion time is NP-hard, we use a heuristic that minimizes the probability of increasing the maximum of these decoding-delay-dependent completion time expressions after each transmission through a layered control of their decoding delays. Simulation results show that this new algorithm achieves both a lower mean completion time and mean decoding delay compared to the best known heuristic for completion time reduction. The gap in performance becomes significant for harsh erasure scenarios.