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Sample records for beam techniques coupled

  1. Experience with Kicker Beam Coupling Reduction Techniques

    CERN Document Server

    Gaxiola, Enrique; Caspers, Friedhelm; Ducimetière, Laurent; Kroyer, Tom

    2005-01-01

    SPS beam impedance is still one of the worries for operation with nominal LHC beam over longer periods, once the final configuration will be installed in 2006. Several CERN SPS kickers suffer from significant beam induced ferrite heating. In specific cases, for instance beam scrubbing, the temperature of certain ferrite yokes went beyond the Curie point. Several retrofit impedance reduction techniques have been investigated theoretically and with practical tests. We report on experience gained during the 2004 SPS operation with resistively coated ceramic inserts in terms of kicker heating, pulse rise time, operating voltage, and vacuum behaviour. For another technique using interleaved metallic stripes we observed significant improvements in bench measurements. Advantages and drawbacks of both methods and potential combinations of them are discussed and simulation as well as measured data are shown. Prospects for further improvements beyond 2006 are briefly outlined.

  2. A Retrofit Technique for Kicker Beam-Coupling Impedance Reduction

    CERN Document Server

    Caspers, Friedhelm; Kroyer, T; Timmins, M; Uythoven, J; Kurennoy, S

    2004-01-01

    The reduction of the impedance of operational ferrite kicker structures may be desirable in order to avoid rebuilding such a device. Often resistively coated ceramic plates or tubes are installed for this purpose but at the expense of available aperture. Ceramic U-shaped profiles with a resistive coating fitting between the ellipse of the beam and the rectangular kicker aperture have been used to significantly reduce the impedance of the magnet, while having a limited effect on the available physical aperture. Details of this method, constraints, measurements and simulation results as well as practical aspects are presented and discussed.

  3. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A; Laird, J S; Bardos, R A; Legge, G J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T; Sekiguchi, H [Electrotechnical Laboratory, Tsukuba (Japan).

    1994-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  4. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

    1993-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  5. Advanced electron beam techniques

    International Nuclear Information System (INIS)

    Hirotsu, Yoshihiko; Yoshida, Yoichi

    2007-01-01

    After 100 years from the time of discovery of electron, we now have many applications of electron beam in science and technology. In this report, we review two important applications of electron beam: electron microscopy and pulsed-electron beam. Advanced electron microscopy techniques to investigate atomic and electronic structures, and pulsed-electron beam for investigating time-resolved structural change are described. (author)

  6. Beam Techniques - Beam Control and Manipulation

    International Nuclear Information System (INIS)

    Minty, Michiko G

    2003-01-01

    We describe commonly used strategies for the control of charged particle beams and the manipulation of their properties. Emphasis is placed on relativistic beams in linear accelerators and storage rings. After a brief review of linear optics, we discuss basic and advanced beam control techniques, such as transverse and longitudinal lattice diagnostics, matching, orbit correction and steering, beam-based alignment, and linac emittance preservation. A variety of methods for the manipulation of particle beam properties are also presented, for instance, bunch length and energy compression, bunch rotation, changes to the damping partition number, and beam collimation. The different procedures are illustrated by examples from various accelerators. Special topics include injection and extraction methods, beam cooling, spin transport and polarization

  7. Beam Techniques - Beam Control and Manipulation

    Energy Technology Data Exchange (ETDEWEB)

    Minty, Michiko G

    2003-04-24

    We describe commonly used strategies for the control of charged particle beams and the manipulation of their properties. Emphasis is placed on relativistic beams in linear accelerators and storage rings. After a brief review of linear optics, we discuss basic and advanced beam control techniques, such as transverse and longitudinal lattice diagnostics, matching, orbit correction and steering, beam-based alignment, and linac emittance preservation. A variety of methods for the manipulation of particle beam properties are also presented, for instance, bunch length and energy compression, bunch rotation, changes to the damping partition number, and beam collimation. The different procedures are illustrated by examples from various accelerators. Special topics include injection and extraction methods, beam cooling, spin transport and polarization.

  8. Beam echoes in the presence of coupling

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Axel [Case Western Reserve U.

    2017-10-03

    Transverse beam echoes could provide a new technique of measuring diusion characteristics orders of magnitude faster than the current methods; however, their interaction with many accelerator parameters is poorly understood. Using a program written in C, we explored the relationship between coupling and echo strength. We found that echoes could be generated in both dimensions, even with a dipole kick in only one dimension. We found that the echo eects are not destroyed even when there is strong coupling, falling o only at extremely high coupling values. We found that at intermediate values of skew quadrupole strength, the decoherence time of the beam is greatly increased, causing a destruction of the echo eects. We found that this is caused by a narrowing of the tune width of the particles. Results from this study will help to provide recommendations to IOTA (Integrable Optics Test Accelerator) for their upcoming echo experiment.

  9. Polarization coupling of vector Bessel–Gaussian beams

    International Nuclear Information System (INIS)

    Takeuchi, Ryushi; Kozawa, Yuichi; Sato, Shunichi

    2013-01-01

    We report polarization coupling of radial and azimuthal electric field components of a vector light beam as predicted by the fact that the vector Helmholtz equation is expressed as coupled differential equations in cylindrical coordinates. To clearly observe the polarization variation of a beam as it propagates, higher order transverse modes of a vector Bessel–Gaussian beam were generated by a gain distribution modulation technique, which created a narrow ring-shaped gain region in a Nd:YVO 4 crystal. The polarization coupling was confirmed by the observation that the major polarization component of a vector Bessel–Gaussian beam alternates between radial and azimuthal components along with the propagation. (paper)

  10. Coupled-Beam and Coupled-Bunch Instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Burov, Alexey [Fermilab

    2016-06-23

    A problem of coupled-beam instability is solved for two multibunch beams with slightly different revolution frequencies, as in the Fermilab Recycler Ring (RR). Sharing of the inter-bunch growth rates between the intra-bunch modes is described. The general analysis is applied to the RR; possibilities to stabilize the beams by means of chromaticity, feedback and Landau damping are considered.

  11. Coupling creep and damage in concrete under high sustained loading: Experimental investigation on bending beams and application of Acoustic Emission technique

    Directory of Open Access Journals (Sweden)

    Grondin F.

    2010-06-01

    Full Text Available Creep and damage in concrete govern the long-term deformability of concrete. Thus, it is important to understand the interaction between creep and damage in order to design reliable civil engineering structures subjected to high level loading during a long time. Many investigations have been performed on the influence of concrete mixture, the effect of the bond between the matrix and the aggregates, temperature, aging and the size effect on the cracking mechanism and fracture parameters of concrete. But there is a lack of results on the influence of the creep loading history. In the present paper, an experimental investigation on the fracture properties of concrete beams submitted to three point bending tests with high levels of sustained load that deals with creep is reported. The results aim first to investigate the ranges of variation of the time response due to creep damage coupled effects under constant load and secondly to evaluate the residual capacity after creep. For this purpose a series of tests were carried out on geometrically similar specimens of size 100x200x800mm with notch to depth ratio of 0.2 in all the test specimens. The exchange of moisture was prevented and beams were subjected to a constant load of 70% and 90% of the maximum capacity. Three point bending test were realized on specimen at the age of 28 days to determine the characteristics of concrete and the maximum load so we could load the specimens in creep. Threepoint bend creep tests were performed on frames placed in a climate controlled chamber [1]. Then after four months of loading, the beams subjected to creep were removed from the creep frames and then immediately subjected to three-point bending test loading up to failure with a constant loading rate as per RILEM-FMC 50 recommendations. The residual capacity on the notched beams and the evolution of the characteristics of concrete due to the basic creep was considered. The results show that sustained loading

  12. Coupling creep and damage in concrete under high sustained loading: Experimental investigation on bending beams and application of Acoustic Emission technique

    Science.gov (United States)

    Saliba, J.; Loukili, A.; Grondin, F.

    2010-06-01

    Creep and damage in concrete govern the long-term deformability of concrete. Thus, it is important to understand the interaction between creep and damage in order to design reliable civil engineering structures subjected to high level loading during a long time. Many investigations have been performed on the influence of concrete mixture, the effect of the bond between the matrix and the aggregates, temperature, aging and the size effect on the cracking mechanism and fracture parameters of concrete. But there is a lack of results on the influence of the creep loading history. In the present paper, an experimental investigation on the fracture properties of concrete beams submitted to three point bending tests with high levels of sustained load that deals with creep is reported. The results aim first to investigate the ranges of variation of the time response due to creep damage coupled effects under constant load and secondly to evaluate the residual capacity after creep. For this purpose a series of tests were carried out on geometrically similar specimens of size 100x200x800mm with notch to depth ratio of 0.2 in all the test specimens. The exchange of moisture was prevented and beams were subjected to a constant load of 70% and 90% of the maximum capacity. Three point bending test were realized on specimen at the age of 28 days to determine the characteristics of concrete and the maximum load so we could load the specimens in creep. Threepoint bend creep tests were performed on frames placed in a climate controlled chamber [1]. Then after four months of loading, the beams subjected to creep were removed from the creep frames and then immediately subjected to three-point bending test loading up to failure with a constant loading rate as per RILEM-FMC 50 recommendations. The residual capacity on the notched beams and the evolution of the characteristics of concrete due to the basic creep was considered. The results show that sustained loading had a strengthening

  13. From the coupling between ion beam analysis techniques and physico-chemical characterization methods to the study of irradiation effects on materials behaviour

    International Nuclear Information System (INIS)

    Millard-Pinard, N.

    2003-01-01

    The general purpose of my research work is to follow and to interpret the surface evolution of materials, which have received several treatments. During my PhD and my post-doc work, my field of research was tribology. Since I arrived in the 'Aval du Cycle Electronucleaire' group of the Institut de Physique Nucleaire de Lyon, my research activities are in line with the CNRS program 'PACE ' (Programme sur l'Aval du Cycle Electronucleaire) within the ACTINET network. They are coordinated by the PARIS (Physico-chimie des actinides et autres radioelements en solution et aux interfaces) and NOMADE (NOuveaux MAteriaux pour les DEchets) GDR with ANDRA (Agence Nationale pour la gestion des Dechets RAdioactifs), EDF and IRSN (Institut de Radioprotection et de Surete Nucleaire) as partner organisations. My work focused on the study of fission products and actinides migration in barrier materials, which may be capable of assuring the long term safety of deep geological repositories. Until now, it was necessary to use the coupling of ion beam analysis techniques and physico-chemical characterization techniques. During the last few months, I have became interested in understanding radiolytic effects. This new orientation has led us to use ion beams as an irradiating tool. These irradiation experiments are pursued in three major projects. The study of cobalt sulfide inhibition effects of radiolysis gas production during the irradiation of model organic molecules. This is a collaboration with the IRSN, the Institut de Recherche sur la Catalyse and the Ecole Nationale Superieure des Mines de Saint-Etienne. A PhD, co-directed by M. Pijolat from ENSMSE and myself, concerning this study will start in October 2003. Water radiolysis effects on iron corrosion are also studied in the particular case of vitrified nuclear waste containers, which will be stored in deep geological repositories. One ANDRA financed PhD, co-directed by Nathalie Moncoffre and myself, is dedicated to this study

  14. Beam coupling impedance of fast stripline beam kickers

    International Nuclear Information System (INIS)

    Caporaso, G; Chen, Y J; Nelson, A D; Poole, B R

    1999-01-01

    A fast stripline beam kicker is used to dynamically switch a high current electron beam between two beamlines. The transverse dipole impedance of a stripline beam kicker has been previously determined from a simple transmission line model of the structure. This model did not include effects due to the long axial slots along the structure as well as the cavities and coaxial feed transition sections at the ends of the structure. 3-D time domain simulations show that the simple transmission line model underestimates the low frequency dipole beam coupling impedance by about 20% for our structure. In addition, the end cavities and transition sections can exhibit dipole impedances not included in the transmission line model. For high current beams, these additional dipole coupling terms can provide additional beam-induced steering effects not included in the transmission line model of the structure

  15. Enhanced laser beam coupling to a plasma

    International Nuclear Information System (INIS)

    Steiger, A.D.; Woods, C.H.

    1976-01-01

    Density perturbations are induced in a heated plasma by means of a pair of oppositely directed, polarized laser beams of the same frequency. The wavelength of the density perturbations is equal to one half the wavelength of the laser beams. A third laser beam is linearly polarized and directed at the perturbed plasma along a line that is perpendicular to the direction of the two opposed beams. The electric field of the third beam is oriented to lie in the plane containing the three beams. The frequency of the third beam is chosen to cause it to interact resonantly with the plasma density perturbations, thereby efficiently coupling the energy of the third beam to the plasma. 10 claims, 2 figures

  16. Determination of beam coupling impedance in the frequency domain

    Energy Technology Data Exchange (ETDEWEB)

    Niedermayer, Uwe

    2016-07-01

    The concept of beam coupling impedance describes the electromagnetic interaction of uniformly moving charged particles with their surrounding structures in the Frequency Domain (FD). In synchrotron accelerators, beam coupling impedances can lead to beam induced component heating and coherent beam instabilities. Thus, in order to ensure the stable operation of a synchrotron, its impedances have to be quantified and their effects have to be controlled. Nowadays, beam coupling impedances are mostly obtained by Fourier transform of wake potentials, which are the results of Time Domain (TD) simulations. However, at low frequencies, low beam velocity, or for dispersive materials, TD simulations become unhandy. In this area, analytical calculations of beam coupling impedance in the FD, combined with geometry approximations, are still widely used. This thesis describes the development of two electromagnetic field solvers to obtain the beam coupling impedance directly in the FD, where the beam velocity is only a parameter and dispersive materials can be included easily. One solver is based on the Finite Integration Technique (FIT) on a staircase mesh. It is implemented both in 2D and 3D. However, the staircase mesh is inefficient on curved structures, which is particularly problematic for the modeling of a dipole source, that is required for the computation of the transverse beam coupling impedance. This issue is overcome by the second solver developed in this thesis, which is based on the Finite Element Method (FEM) on an unstructured triangular mesh. It is implemented in 2D and includes an optional Surface Impedance Boundary Condition (SIBC). Thus, it is well suited for the computation of longitudinal and transverse impedances of long beam pipe structures of arbitrary cross-section. Besides arbitrary frequency and beam velocity, also dispersive materials can be chosen, which is crucial for the computation of the impedance of ferrite kicker magnets. Numerical impedance

  17. The Harmonically Coupled 2-Beam FEL

    CERN Document Server

    McNeil, Brian W J

    2004-01-01

    A 1-D model of a 2-beam Free Electron Laser amplifier is presented. The two co-propagating electron beams have different energies, chosen so that the fundamental resonant FEL interaction of the higher energy beam is at an harmonic of the lower energy beam. In this way, a coupling between the FEL interactions of the two beams occurs via the harmonic components of the electron bunching and radiation emission of the lower energy interaction. Such resonantly coupled FEL interactions may offer potential benefits over existing single beam FEL schemes. A simple example is presented where the lower energy FEL interaction only is seeded with radiation at its fundamental resonant wavelength. It is predicted that the coherence properties of this seed field are transfered via the resonantly coupled FEL interaction to the un-seeded higher energy FEL interaction, thereby improving its coherence properties over that of a SASE interaction alone. This method may offer an alternative seeding scheme for FELs operating in the XU...

  18. Ion beam techniques in arts and archaeology

    International Nuclear Information System (INIS)

    Qin Guangyong; Pan Xianjia; Sun Zhongtian; Gao Zhengyao

    1991-01-01

    The ion beam techniques used in studies of arts and archaeology are compared with other analytical techniques. Some examples are specially selected to illustrate the achievements and trends of the techniques in this field

  19. Canonical formalism for coupled beam optics

    International Nuclear Information System (INIS)

    Kheifets, S.A.

    1989-09-01

    Beam optics of a lattice with an inter-plane coupling is treated using canonical Hamiltonian formalism. The method developed is equally applicable both to a circular (periodic) machine and to an open transport line. A solution of the equation of a particle motion (and correspondingly transfer matrix between two arbitrary points of the lattice) are described in terms of two amplitude functions (and their derivatives and corresponding phases of oscillations) and four coupling functions, defined by a solution of the system of the first-order nonlinear differential equations derived in the paper. Thus total number of independent parameters is equal to ten. 8 refs

  20. Techniques to sort Bessel beams

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2013-09-01

    Full Text Available -polar coordinate transformation, translating helically phased beams into a transverse phase gradient. By introducing two cylindrical lenses we can focus each of the azimuthal modes associated with each Bessel beam to a different lateral position in the Fourier...

  1. Compact beam splitters in coupled waveguides using shortcuts to adiabaticity

    Science.gov (United States)

    Chen, Xi; Wen, Rui-Dan; Shi, Jie-Long; Tseng, Shuo-Yen

    2018-04-01

    There are various works on adiabatic (three) waveguide coupler devices but most are focused on the quantum optical analogies and the physics itself. We successfully apply shortcuts to adiabaticity techniques to the coupled waveguide system with a suitable length for integrated optics devices. Especially, the counter-diabatic driving protocol followed by unitary transformation overcomes the previously unrealistic implemention, and is used to design feasible and robust 1 × 2 and 1 × 3 beam splitters for symmetric and asymmetric three waveguide couplers. Numerical simulations with the beam propagation method demonstrate that these shortcut designs for beam splitters are shorter than the adiabatic ones, and also have a better tolerance than parallel waveguides resonant beam splitters with respect to spacing errors and wavelength variation.

  2. New analytical methods for materials characterization using the techniques of nuclear activation reactions induced by thermal neutrons and accelerated ion beams, coupled to gamma-ray spectroscopy

    International Nuclear Information System (INIS)

    Cincu, Emanuela

    1999-01-01

    This thesis is a comprehensive collection of the author's works in the field of 'Nuclear Activation Techniques with accelerated Charged Particles and Thermal Neutrons' carried out within the framework of the research contracts the author initiated and performed in the period 1990 - 1999. The works objective was to achieve a consistent and complete methodological and instrumental assembly for accurate elemental analysis of technological samples of interest for industry, medicine, and monitoring of the environmental radioactivity. The experiments were carried out using the IFIN-HH facilities: U-120 Cyclotron, 8 MV Tandem Van de Graaff accelerator, and the WWR-S nuclear reactor. Part of the reported works were initiated and performed in collaboration with partners from the chemical industry and metallurgic industry, wishing to employ the sensitive nuclear analytical techniques, which are able to put in evidence simultaneously major, minor elements, and impurities in the investigated samples. The impact with the challenging topics and the characteristics of some investigated technological samples, generated the studies having both theoretical and experimental features, presented in this thesis, as well as the original analytical and methodological solutions. The thesis structure has two parts: The 1st part (Chapter 1) is a survey of the literature until 1999, that concerns the theory of nuclear activation reactions with accelerated charged particles (CPAA) and thermal neutrons (NAA), evidencing the analytical performance of both techniques; details are also given about the 'critical' phenomena encountered in CPAA, whose origin is still under discussion in the literature. The 2 nd part of the thesis contains the original contributions of the author in the theoretical, methodological, and software fields (Chapters 2-8), the experimental results obtained, and the nuclear database software based on the 'Fox-Pro' operation system, conceived for processing the experimental

  3. Numerical calculation of beam coupling impedances in synchrotron accelerators

    International Nuclear Information System (INIS)

    Haenichen, Lukas

    2016-01-01

    Beams of charged particles are of interest in various fields of research including particle and nuclear physics, material and medical science and many more. In synchrotron accelerators the accelerating section is passed periodically. A closed loop trajectory is enforced, by increasing the frequency of the accelerating electric field and the magnitude of the dipolar magnetic guide field synchronously. A synchrotron therefore consists of a circular assembly of various beamline elements which serve the purposes of accelerating and guiding the particle beam. For the flawless operation of such a machine it has to be assured that the particles perform a controlled motion along predefined trajectories. Amongst others, the fulfillment of the corresponding stability criteria is in close conjuction with the so-called beam coupling impedances which are an important figure of merit for collective effects in synchrotron accelerators. This work focuses on analytical and numerical methods for the calculation of beam coupling impedances. One of the primary objectives is to gain a better understanding of the electrodynamics related to charged particle beams, furthermore to recapitulate the mathematical description of charged particle beams in both time and frequency domain and finally establish the links between actual physics and numerical modeling. Analytical methods are usually restricted to symmetrical geometry and may solely serve for the approximate determination of the field distribution in real geometries or to validate certain numerical methods. More accurate prognosis is only possible with three-dimensional simulation models. Numerical simulation techniques have been established in the second half of the last century accompanying the evolution of many particle accelerators. Classical time domain codes were the prevailing simulation tools where the actual process of the particle motion sequence is reproduced. For the present case of a heavy ion synchrotron accelerator

  4. Numerical calculation of beam coupling impedances in synchrotron accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Haenichen, Lukas

    2016-07-01

    Beams of charged particles are of interest in various fields of research including particle and nuclear physics, material and medical science and many more. In synchrotron accelerators the accelerating section is passed periodically. A closed loop trajectory is enforced, by increasing the frequency of the accelerating electric field and the magnitude of the dipolar magnetic guide field synchronously. A synchrotron therefore consists of a circular assembly of various beamline elements which serve the purposes of accelerating and guiding the particle beam. For the flawless operation of such a machine it has to be assured that the particles perform a controlled motion along predefined trajectories. Amongst others, the fulfillment of the corresponding stability criteria is in close conjuction with the so-called beam coupling impedances which are an important figure of merit for collective effects in synchrotron accelerators. This work focuses on analytical and numerical methods for the calculation of beam coupling impedances. One of the primary objectives is to gain a better understanding of the electrodynamics related to charged particle beams, furthermore to recapitulate the mathematical description of charged particle beams in both time and frequency domain and finally establish the links between actual physics and numerical modeling. Analytical methods are usually restricted to symmetrical geometry and may solely serve for the approximate determination of the field distribution in real geometries or to validate certain numerical methods. More accurate prognosis is only possible with three-dimensional simulation models. Numerical simulation techniques have been established in the second half of the last century accompanying the evolution of many particle accelerators. Classical time domain codes were the prevailing simulation tools where the actual process of the particle motion sequence is reproduced. For the present case of a heavy ion synchrotron accelerator

  5. A Physical Description of the Response of Coupled Beams

    DEFF Research Database (Denmark)

    Hugin, Claus Thomas

    1997-01-01

    An analytical method is presented for computing the vibrational response and the net transmitted power of bending wave fields in system consisting of coupled finite beams. The method is based on a wave approach that utilises the reflection and transmission coefficients of the different beam joint...... are valid for frequencies above which the influence of the reflected near fields for each of the beam elements is negligible. The method is demonstrated on different configurations of beams coupled in extension of each other....

  6. Techniques for beam impedance measurements above cutoff

    International Nuclear Information System (INIS)

    Lambertson, G.R.; Jacob, A.F.; Rimmer, R.A.; Voelker, F.

    1990-08-01

    Methods for measuring beam impedance above cutoff have been very limited. For design work on the ALS we have developed two techniques that yield data in the frequency domain with high sensitivity. The first is an extension of the wire method; the second utilizes traveling TM waves to simulate the beam's fields at the wall, and thus avoids the mechanical difficulties of mounting the wire. It is also more sensitive than the other method but the interpretation is complicated by the presence of higher order modes. With either method we were able to detect resonant peaks smaller than 1 Ohm at 10 GHz

  7. Compensation techniques in NIRS proton beam radiotherapy

    International Nuclear Information System (INIS)

    Akanuma, A.; Majima, H.; Furukawa, S.

    1982-01-01

    Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods

  8. Compensation techniques in NIRS proton beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Akanuma, A. (Univ. of Tokyo, Japan); Majima, H.; Furukawa, S.

    1982-09-01

    Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods.

  9. Electron beam instrumentation techniques using coherent radiation

    International Nuclear Information System (INIS)

    Wang, D.X.

    1997-01-01

    Much progress has been made on coherent radiation research since coherent synchrotron radiation was first observed in 1989. The use of coherent radiation as a bunch length diagnostic tool has been studied by several groups. In this paper, brief introductions to coherent radiation and far-infrared measurement are given, the progress and status of their beam diagnostic application are reviewed, different techniques are described, and their advantages and limitations are discussed

  10. Radioactive ion beams and techniques for solid state research

    International Nuclear Information System (INIS)

    Correia, J.G.

    1998-01-01

    In this paper we review the most recent and new applications of solid state characterization techniques using radioactive ion beams. For such type ofresearch, high yields of chemically clean ion beams of radioactive isotopesare needed which are provided by the on-line coupling of high resolution isotope separators to particle accelerators, such as the isotope separator on-line (ISOLDE) facility at CERN. These new experiments are performed by an increasing number of solid state groups. They combine nuclear spectroscopic techniques such as Moessbauer, perturbed angular correlations (PAC) and emission channeling with the traditional non-radioactive techniques liked deep level transient spectroscopy (DLTS) and Hall effect measurements. Recently isotopes of elements, not available before, were successfully used in new PAC experiments, and the first photoluminescence (PL) measurements, where the element transmutation plays the essential role on the PL peak identification, have been performed. The scope of applications of radioactive ion beams for research in solid state physics will be enlarged in the near future, with the installation at ISOLDE of a post-accelerator device providing radioactive beams with energies ranging from a few keV up to a few MeV. (orig.)

  11. The modified couple stress functionally graded Timoshenko beam formulation

    International Nuclear Information System (INIS)

    Asghari, M.; Rahaeifard, M.; Kahrobaiyan, M.H.; Ahmadian, M.T.

    2011-01-01

    In this paper, a size-dependent formulation is presented for Timoshenko beams made of a functionally graded material (FGM). The formulation is developed on the basis of the modified couple stress theory. The modified couple stress theory is a non-classic continuum theory capable to capture the small-scale size effects in the mechanical behavior of structures. The beam properties are assumed to vary through the thickness of the beam. The governing differential equations of motion are derived for the proposed modified couple-stress FG Timoshenko beam. The generally valid closed-form analytic expressions are obtained for the static response parameters. As case studies, the static and free vibration of the new model are respectively investigated for FG cantilever and FG simply supported beams in which properties are varying according to a power law. The results indicate that modeling beams on the basis of the couple stress theory causes more stiffness than modeling based on the classical continuum theory, such that for beams with small thickness, a significant difference between the results of these two theories is observed.

  12. All-optical optoacoustic microscopy based on probe beam deflection technique

    OpenAIRE

    Maswadi, Saher M.; Ibey, Bennett L.; Roth, Caleb C.; Tsyboulski, Dmitri A.; Beier, Hope T.; Glickman, Randolph D.; Oraevsky, Alexander A.

    2016-01-01

    Optoacoustic (OA) microscopy using an all-optical system based on the probe beam deflection technique (PBDT) for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i) efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii) undistorted coupling of acoustic waves to the detector without the need for separa...

  13. Moving strip technique of electron beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, Kishio; Wakasa, Hiroyuki; Oguri, Nobuhiro; Kitayama, Takuichi; Nakagiri, Yoshitada; Mikami, Yasutaka; Hashimoto, Keiji; Hiraki, Yoshio; Aono, Kaname

    1984-12-01

    The fieldsize in electron beam therapy is determined by the cone size. In case of skin metastasis of a malignant tumor and so on, which need a large field size and whose area is much larger than the size of the cone, a large field size is usually produced by dividing the portals. However, the dose distribution at the border of the field becomes unequal, and hot and cold dose areas are produced according to the distance between portals. We tried the strip field technique in a large field along the long axis of the body in order to flatten the dose of the border employing the moving strip used for whole abdominal irradiation in ovarian cancer. We set the film in Mix-DP and used the strip field technique with 2.5cm steps. We discussed the relationship between the interval (distance between portals) and the flattening of the dose within the field. Skin movement due to breathing and influences on the flattening of the dose were considered. The proper flatness was obtained at depths of 0,1,2, and 3cm by setting the interval at 0.5cm. When skin movement was produced by breathing in +-1.5mm, the proper flaness was obtained also at a 0.5-cm interval. It seems that smoothing is increased by breathing. An ''electron beam moving strip'' with a 2.5-cm step and 0.5-cm interval was clinically effective in the treatment of patients with skin metastasis of colon cancer. (author).

  14. Efficient shortcut techniques in evanescently coupled waveguides

    Science.gov (United States)

    Paul, Koushik; Sarma, Amarendra K.

    2016-10-01

    Shortcut to Adiabatic Passage (SHAPE) technique, in the context of coherent control of atomic systems has gained considerable attention in last few years. It is primarily because of its ability to manipulate population among the quantum states infinitely fast compared to the adiabatic processes. Two methods in this regard have been explored rigorously, namely the transitionless quantum driving and the Lewis-Riesenfeld invariant approach. We have applied these two methods to realize SHAPE in adiabatic waveguide coupler. Waveguide couplers are integral components of photonic circuits, primarily used as switching devices. Our study shows that with appropriate engineering of the coupling coefficient and propagation constants of the coupler it is possible to achieve efficient and complete power switching. We also observed that the coupler length could be reduced significantly without affecting the coupling efficiency of the system.

  15. On the longitudinal coupling impedance of a toroidal beam tube

    International Nuclear Information System (INIS)

    Hahn, H.; Tepikian, S.

    1990-01-01

    In this paper, the longitudinal coupling impedance of a smooth toroidal beam tube is derived. By treating the torus as a slow-wave structure, the well-known method of describing the impedance in terms of cavity resonances can be used. A simple analytical expression for the coupling impedance of a toroidal beam tube with square cross section valid in the low-frequency limit is obtained. The results from the present study are compared with previously published solutions and qualitative differences are pointed out. 16 refs., 3 figs., 1 tab

  16. Transfer of temporal fluctuations in photorefractive two-beam coupling

    DEFF Research Database (Denmark)

    Juul Jensen, S.; Saffman, M.

    1997-01-01

    Transfer of temporal fluctuations between the signal and pump beams in diffusion dominated photorefractive two-beam coupling is studied experimentally. The dependence on the gain, beam intensity ratio, and frequency of the fluctuations is found to agree well with a linearized analysis, The transf...... of perturbations is frequency dependent at low frequencies, and becomes constant at frequencies large compared to the inverse material time constant. Vde discuss the possibility of pump noise suppression when amplifying weak signals. (C) 1997 American Institute of Physics....

  17. Fiber-optic coupling based on nonimaging expanded-beam optics.

    Science.gov (United States)

    Moslehi, B; Ng, J; Kasimoff, I; Jannson, T

    1989-12-01

    We have fabricated and experimentally tested low-cost and mass-producible multimode fiber-optic couplers and connectors based on nonimaging beam-expanding optics and Liouville's theorem. Analysis indicates that a pair coupling loss of -0.25 dB can be achieved. Experimentally, we measured insertion losses as low as -0.38 dB. The beam expanders can be mass produced owing to the use of plastic injection-molding fabrication techniques and packaged in standard connector housings. This design is compatible with the fiber geometry and can yield highly stable coupling owing to its high tolerance for misalignments.

  18. Electron Beam Polarization Measurement Using Touschek Lifetime Technique

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Changchun; /Duke U., DFELL; Li, Jingyi; /Duke U., DFELL; Mikhailov, Stepan; /Duke U., DFELL; Popov, Victor; /Duke U., DFELL; Wu, Wenzhong; /Duke U., DFELL; Wu, Ying; /Duke U., DFELL; Chao, Alex; /SLAC; Xu, Hong-liang; /Hefei, NSRL; Zhang, Jian-feng; /Hefei, NSRL

    2012-08-24

    Electron beam loss due to intra-beam scattering, the Touschek effect, in a storage ring depends on the electron beam polarization. The polarization of an electron beam can be determined from the difference in the Touschek lifetime compared with an unpolarized beam. In this paper, we report on a systematic experimental procedure recently developed at Duke FEL laboratory to study the radiative polarization of a stored electron beam. Using this technique, we have successfully observed the radiative polarization build-up of an electron beam in the Duke storage ring, and determined the equilibrium degree of polarization and the time constant of the polarization build-up process.

  19. High current density ion beam measurement techniques

    International Nuclear Information System (INIS)

    Ko, W.C.; Sawatzky, E.

    1976-01-01

    High ion beam current measurements are difficult due to the presence of the secondary particles and beam neutralization. For long Faraday cages, true current can be obtained only by negative bias on the target and by summing the cage wall and target currents; otherwise, the beam will be greatly distorted. For short Faraday cages, a combination of small magnetic field and the negative target bias results in correct beam current. Either component alone does not give true current

  20. Emittance and beam size distortion due to linear coupling

    International Nuclear Information System (INIS)

    Parzen, G.

    1993-01-01

    At injection, the presence of linear coupling may result in an increased beam emittance and in increased beam dimensions. Results for the emittance in the presence of linear coupling will be found. These results for the emittance distortion show that the harmonics of the skew quadrupole field close to ν x + ν y are the important harmonics. Results will be found for the important driving terms for the emittance distortion. It will be shown that if these driving terms are corrected, then the total emittance is unchanged, var-epsilon x + var-epsilon y = var-epsilon 1 + var-epsilon 2 . Also, the increase in the beam dimensions will be limited to a factor which is less than 1.414. If the correction is good enough, see below for details, one can achieve var-epsilon 1 = var-epsilon x , var-epsilon 2 = var-epsilon where var-epsilon 1 , var-epsilon 2 are the emittances in the presence of coupling, and the beam dimensions are unchanged. Global correction of the emittance and beam size distortion appears possible

  1. Ultracompact multiway beam splitters using multiple coupled photonic crystal waveguides

    International Nuclear Information System (INIS)

    Yu Tianbao; Zhou Haifeng; Yang Jianyi; Jiang Xiaoqing; Wang Minghua; Gong Zhao

    2008-01-01

    Ultracompact 1 x N (N > 2) beam splitters based on coupling of multiple photonic crystal waveguides (PCWs) are numerically demonstrated. The operation of the devices is on the basis of the self-imaging phenomenon. Variation of the effective index of modified rods induces the transverse redistribution of the N-fold images with the same coupling length, and uniform or free splitting can be achieved. The devices with three and four output channels are discussed in details as examples. Results show that this kind of beam splitters are very short. At the operating wavelength of 1.55 μm, the splitting length of the devices is only 35 μm even if the output channel number reaches 20. It provides a new method and a compact model to export freely the beam to N channels in PCW devices and can find practical applications in future photonic integrated circuits

  2. Ultracompact multiway beam splitters using multiple coupled photonic crystal waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Yu Tianbao; Zhou Haifeng; Yang Jianyi; Jiang Xiaoqing; Wang Minghua [Department of Information Science and Electronic Engineering, Zhejiang University, 310027 Hangzhou (China); Gong Zhao [Zhejiang University City College, 310027 Hangzhou (China)

    2008-05-07

    Ultracompact 1 x N (N > 2) beam splitters based on coupling of multiple photonic crystal waveguides (PCWs) are numerically demonstrated. The operation of the devices is on the basis of the self-imaging phenomenon. Variation of the effective index of modified rods induces the transverse redistribution of the N-fold images with the same coupling length, and uniform or free splitting can be achieved. The devices with three and four output channels are discussed in details as examples. Results show that this kind of beam splitters are very short. At the operating wavelength of 1.55 {mu}m, the splitting length of the devices is only 35 {mu}m even if the output channel number reaches 20. It provides a new method and a compact model to export freely the beam to N channels in PCW devices and can find practical applications in future photonic integrated circuits.

  3. Flush-mounting technique for composite beams

    Science.gov (United States)

    Harman, T. C.; Kay, B. F.

    1980-01-01

    Procedure permits mounting of heavy parts to surface of composite beams without appreciably weakening beam web. Web is split and held apart in region where attachment is to be made by lightweight precast foam filler. Bolt hole penetrates foam rather than web, and is secured by barrelnut in transverse bushing through web.

  4. Coupling Impedance of the CERN SPS beam position monitors

    CERN Document Server

    Salvant, B; Boccard, C; Caspers, Friedhelm; Grudiev, A; Jones, R; Métral, E; Rumolo, G; Zannini, C; Spataro, B; Alesini, D; Migliorati, M; Roncarolo, F; Calaga, R

    2010-01-01

    A detailed knowledge of the beam coupling impedance of the CERN Super Proton Synchrotron (SPS) is required in order to operate this machine with a higher intensity for the foreseen Large Hadron Collider (LHC) luminosity upgrade. A large number of Beam Position Monitors (BPMs) is currently installed in the SPS, and this is why their contribution to the SPS impedance has to be assessed. This paper focuses on electromagnetic (EM) simulations and bench measurements of the longitudinal and transverse impedance generated by the horizontal and vertical BPMs installed in the SPS machine.

  5. LHC MD2877: Beam-beam long range impact on coupling measurements

    CERN Document Server

    Wenninger, Jorg; Carlier, Felix Simon; Coello De Portugal - Martinez Vazquez, Jaime Maria; Fuchsberger, Kajetan; Hostettler, Michi; Persson, Tobias Hakan Bjorn; Tomas Garcia, Rogelio; Valuch, Daniel; Garcia-Tabares Valdivieso, Ana; CERN. Geneva. ATS Department

    2018-01-01

    The LHC is now operating with a tune separation of ∼0.004 in collision. This puts tight constraints on the allowed transverse coupling since a |C−| larger than a fraction of the fractional tune split may lead to beam instabilities. In the last years a new tool based on the ADT used in a similar way as an AC-dipole to excite the beam was developed. The ADT AC-dipole gives coherent oscillations without increasing the beam emittance. These oscillations are analyzed automatically to obtain the value of the coupling. A coupling measurement campaign was done in 2017 and while the correction converged and stayed rather constant over time it was observed that depending on the target bunch and filling scheme the results could vary by Δ|C−| ∼ 0.002. In this MD report we investigated 3 different bunches, one with Long Range Beam-Beam (LRBB) in IPs 1 and 5, one with LRBB in all IPs and one with no LRBB. The results indicate that there are differences in coupling between the bunches experiencing different LR...

  6. A feasibility study of H{sup -} beam extraction technique using YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Meigo, Shin-ichiro; Hasegawa, Kazuo; Ikeda, Yujiro; Oigawa, Hiroyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Aoki, Nobutada [Toshiba Power System Co., Ltd. (Japan); Nakagawa, Satoshi [Toshiba Co., Tokyo (Japan)

    2002-12-01

    Under a framework of JAERI-KEK joint project of high intensity proton accelerator, as for research and develop of the accelerator driven nuclear transmutation of the long lived radioactive nuclide, it is planed to built the Transmutation Physics Experiment Facility (TEF-P) and the Transmutation Engineering Experiment Facility (TEF-E). The TEF-P is used for the experiments for subcritical system coupled with a spallation neutron target bombarded with 600-MeV proton beam accelerated by the LINAC. To limit the maximum thermal power less than 500 W at the TEF-P, an incident beam power should be less than 10 W. On the contrary, at the TEF-E, high power beam of 200 kW is requested. Both high and low power beams are demanded for the transmutation facilities. It is difficult to deliver a low power beam to the TEF-P. Conventional beam extraction technique with a thin foil, is not desirable because the scattering of the beam at the foil requires the massive shield. Therefore, we study a new technique to extract a small portion of the beam precisely from the high intensity beam by using a laser beam. By a laser beam, H{sup -} in the beam from LINAC is partially changed to H{sup 0} beam so that a low current H{sup 0} beam can be obtained. As the cross section of the charge exchange reaction for H{sup -} ions has a peak around at a wave length of 1 {mu}m for photons, YAG laser is suitable for this charge exchange because of its 1.06 {mu}m wave length. It is derived that 10 W beam for 600-MeV proton can be extracted by the YAG laser with power of 2 J for each pulse of 25 Hz. By this technique, the pulse width for the extracted beam can be controlled by changing the time width of laser irradiation. When a charge exchanger having the beam collide point existing in straight section, a background beam current of projectile, however, will be increased due to the interaction with the residual gas in the beam duct. Thus, a charge exchanger is devised having the beam collide point in a

  7. Probe beam deflection technique as acoustic emission directionality sensor with photoacoustic emission source.

    Science.gov (United States)

    Barnes, Ronald A; Maswadi, Saher; Glickman, Randolph; Shadaram, Mehdi

    2014-01-20

    The goal of this paper is to demonstrate the unique capability of measuring the vector or angular information of propagating acoustic waves using an optical sensor. Acoustic waves were generated using photoacoustic interaction and detected by the probe beam deflection technique. Experiments and simulations were performed to study the interaction of acoustic emissions with an optical sensor in a coupling medium. The simulated results predict the probe beam and wavefront interaction and produced simulated signals that are verified by experiment.

  8. Comparison of composite rotor blade models: A coupled-beam analysis and an MSC/NASTRAN finite-element model

    Science.gov (United States)

    Hodges, Robert V.; Nixon, Mark W.; Rehfield, Lawrence W.

    1987-01-01

    A methodology was developed for the structural analysis of composite rotor blades. This coupled-beam analysis is relatively simple to use compared with alternative analysis techniques. The beam analysis was developed for thin-wall single-cell rotor structures and includes the effects of elastic coupling. This paper demonstrates the effectiveness of the new composite-beam analysis method through comparison of its results with those of an established baseline analysis technique. The baseline analysis is an MSC/NASTRAN finite-element model built up from anisotropic shell elements. Deformations are compared for three linear static load cases of centrifugal force at design rotor speed, applied torque, and lift for an ideal rotor in hover. A D-spar designed to twist under axial loading is the subject of the analysis. Results indicate the coupled-beam analysis is well within engineering accuracy.

  9. Beam-plasma coupling physics in support of active experiments

    Science.gov (United States)

    Yakymenko, K.; Delzanno, G. L.; Roytershteyn, V.

    2017-12-01

    The recent development of compact relativistic accelerators might open up a new era of active experiments in space, driven by important scientific and national security applications. Examples include using electron beams to trace magnetic field lines and establish causality between physical processes occurring in the magnetosphere and those in the ionosphere. Another example is the use of electron beams to trigger waves in the near-Earth environment. Waves could induce pitch-angle scattering and precipitation of energetic electrons, acting as an effective radiation belt remediation scheme. In this work, we revisit the coupling between an electron beam and a magnetized plasma in the framework of linear cold-plasma theory. We show that coupling can occur through two different regimes. In the first, a non-relativistic beam radiates through whistler waves. This is well known, and was in fact the focus of many rockets and space-shuttle campaigns aimed at demonstrating whistler emissions in the eighties. In the second regime, the beam radiates through extraordinary (R-X) modes. Nonlinear simulations with a highly-accurate Vlasov code support the theoretical results qualitatively and demonstrate that the radiated power through R-X modes can be much larger than in the whistler regime. Test-particle simulations in the wave electromagnetic field will also be presented to assess the efficiency of these waves in inducing pitch-angle scattering via wave-particle interactions. Finally, the implications of these results for a rocket active experiment in the ionosphere and for a radiation belt remediation scheme will be discussed.

  10. Automation of neutral beam source conditioning with artificial intelligence techniques

    International Nuclear Information System (INIS)

    Johnson, R.R.; Canales, T.W.; Lager, D.L.

    1985-01-01

    This paper describes a system that automates neutral beam source conditioning. The system achieves this with artificial intelligence techniques. The architecture of the system is presented followed by a description of its performance

  11. Automation of neutral beam source conditioning with artificial intelligence techniques

    International Nuclear Information System (INIS)

    Johnson, R.R.; Canales, T.; Lager, D.

    1986-01-01

    This paper describes a system that automates neutral beam source conditioning. The system achieves this with artificial intelligence techniques. The architecture of the system is presented followed by a description of its performance

  12. Electro-mechanical coupling of rotating 3D beams

    Directory of Open Access Journals (Sweden)

    Stoykov S.

    2016-01-01

    Full Text Available A rotating thin-walled beam with piezoelectric element is analysed. The beam is considered to vibrate in space, hence the longitudinal, transverse and torsional deformations are taken into account. The bending deformations of the beam are modelled by assuming Timoshenko's theory. Torsion is included by considering that the cross section rotates as a rigid body but can deform in longitudinal direction due to warping. The warping function is computed preliminary by the finite element method. The equation of motion is derived by the principle of virtual work and discretized in space by the Ritz method. Electro-mechanical coupling is included in the model by considering the internal electrical energy and the electric charge output. The piezo-electric constitutive relations are used in reduced form. The beam is assumed to rotate about a fixed axis with constant speed. The equation of motion is derived in rotating coordinate system, but the influence of the rotation of the coordinate system is taken into account through the inertia forces. Results in time domain are presented for different speeds of rotation and frequencies of vibration. The influence of the speed of rotation and of the frequency of vibration on the electrical output is presented and analysed.

  13. From the coupling between ion beam analysis techniques and physico-chemical characterization methods to the study of irradiation effects on materials behaviour; Du couplage des techniques d'analyse par faisceaux d'ions et des methodes de caracterisation physico-chimique a l'etude des effets d'irradiation sur le comportement des materiaux

    Energy Technology Data Exchange (ETDEWEB)

    Millard-Pinard, N

    2003-07-01

    The general purpose of my research work is to follow and to interpret the surface evolution of materials, which have received several treatments. During my PhD and my post-doc work, my field of research was tribology. Since I arrived in the 'Aval du Cycle Electronucleaire' group of the Institut de Physique Nucleaire de Lyon, my research activities are in line with the CNRS program 'PACE ' (Programme sur l'Aval du Cycle Electronucleaire) within the ACTINET network. They are coordinated by the PARIS (Physico-chimie des actinides et autres radioelements en solution et aux interfaces) and NOMADE (NOuveaux MAteriaux pour les DEchets) GDR with ANDRA (Agence Nationale pour la gestion des Dechets RAdioactifs), EDF and IRSN (Institut de Radioprotection et de Surete Nucleaire) as partner organisations. My work focused on the study of fission products and actinides migration in barrier materials, which may be capable of assuring the long term safety of deep geological repositories. Until now, it was necessary to use the coupling of ion beam analysis techniques and physico-chemical characterization techniques. During the last few months, I have became interested in understanding radiolytic effects. This new orientation has led us to use ion beams as an irradiating tool. These irradiation experiments are pursued in three major projects. The study of cobalt sulfide inhibition effects of radiolysis gas production during the irradiation of model organic molecules. This is a collaboration with the IRSN, the Institut de Recherche sur la Catalyse and the Ecole Nationale Superieure des Mines de Saint-Etienne. A PhD, co-directed by M. Pijolat from ENSMSE and myself, concerning this study will start in October 2003. Water radiolysis effects on iron corrosion are also studied in the particular case of vitrified nuclear waste containers, which will be stored in deep geological repositories. One ANDRA financed PhD, co-directed by Nathalie Moncoffre and myself, is dedicated to this study

  14. From the coupling between ion beam analysis techniques and physico-chemical characterization methods to the study of irradiation effects on materials behaviour; Du couplage des techniques d'analyse par faisceaux d'ions et des methodes de caracterisation physico-chimique a l'etude des effets d'irradiation sur le comportement des materiaux

    Energy Technology Data Exchange (ETDEWEB)

    Millard-Pinard, N

    2003-07-01

    The general purpose of my research work is to follow and to interpret the surface evolution of materials, which have received several treatments. During my PhD and my post-doc work, my field of research was tribology. Since I arrived in the 'Aval du Cycle Electronucleaire' group of the Institut de Physique Nucleaire de Lyon, my research activities are in line with the CNRS program 'PACE ' (Programme sur l'Aval du Cycle Electronucleaire) within the ACTINET network. They are coordinated by the PARIS (Physico-chimie des actinides et autres radioelements en solution et aux interfaces) and NOMADE (NOuveaux MAteriaux pour les DEchets) GDR with ANDRA (Agence Nationale pour la gestion des Dechets RAdioactifs), EDF and IRSN (Institut de Radioprotection et de Surete Nucleaire) as partner organisations. My work focused on the study of fission products and actinides migration in barrier materials, which may be capable of assuring the long term safety of deep geological repositories. Until now, it was necessary to use the coupling of ion beam analysis techniques and physico-chemical characterization techniques. During the last few months, I have became interested in understanding radiolytic effects. This new orientation has led us to use ion beams as an irradiating tool. These irradiation experiments are pursued in three major projects. The study of cobalt sulfide inhibition effects of radiolysis gas production during the irradiation of model organic molecules. This is a collaboration with the IRSN, the Institut de Recherche sur la Catalyse and the Ecole Nationale Superieure des Mines de Saint-Etienne. A PhD, co-directed by M. Pijolat from ENSMSE and myself, concerning this study will start in October 2003. Water radiolysis effects on iron corrosion are also studied in the particular case of vitrified nuclear waste containers, which will be stored in deep geological repositories. One ANDRA financed PhD, co-directed by Nathalie Moncoffre and myself, is

  15. Verification and application of beam steering Phased Array UT technique for complex structures

    International Nuclear Information System (INIS)

    Yamamoto, Setsu; Miura, Takahiro; Semboshi, Jun; Ochiai, Makoto; Mitsuhashi, Tadahiro; Adachi, Hiroyuki; Yamamoto, Satoshi

    2013-01-01

    Phased Array Ultrasonic Testing (PAUT) techniques for complex geometries are greatly progressing. We developed an immersion PAUT which is suitable for complex surface profiles such as nozzles and deformed welded areas. Furthermore, we have developed a shape adaptive beam steering technique for 3D complex surface structures with conventional array probe and flexible coupling gel which makes the immersion beam forming technique usable under dry conditions. This system consists of 3 steps. Step1 is surface profile measurement which based on 3D Synthesis Aperture Focusing Technique (SAFT), Step2 is delay law calculation which could take into account the measured 3D surface profiles and steer a shape adjusted ultrasonic beam, Step3 is shape adjusted B-scope construction. In this paper, verification results of property of this PAUT system using R60 curved specimen and nozzle shaped specimen which simulated actual BWR structure. (author)

  16. Pulsed beam dosimetry using fiber-coupled radioluminescence detectors

    DEFF Research Database (Denmark)

    Andersen, Claus Erik

    2012-01-01

    The objective of this work was to review and discuss the potential application of fiber-coupled radioluminescence detectors for dosimetry in pulsed MV photon beams. Two types of materials were used: carbon-doped aluminium oxide (Al2O3:C) and organic plastic scintillators. Special consideration...... was given to the discrimination between radioluminescence signals from the phosphors and unwanted light induced in the optical fiber cables during irradiation (Cerenkov and fluorescence). New instrumentation for dose-per-pulse measurements with organic plastic scintillators was developed....

  17. Spatiotemporal light-beam compression from nonlinear mode coupling

    Science.gov (United States)

    Krupa, Katarzyna; Tonello, Alessandro; Couderc, Vincent; Barthélémy, Alain; Millot, Guy; Modotto, Daniele; Wabnitz, Stefan

    2018-04-01

    We experimentally demonstrate simultaneous spatial and temporal compression in the propagation of light pulses in multimode nonlinear optical fibers. We reveal that the spatial beam self-cleaning recently discovered in graded-index multimode fibers is accompanied by significant temporal reshaping and up to fourfold shortening of the injected subnanosecond laser pulses. Since the nonlinear coupling among the modes strongly depends on the instantaneous power, we explore the entire range of the nonlinear dynamics with a single optical pulse, where the optical power is continuously varied across the pulse profile.

  18. Normal form analysis of linear beam dynamics in a coupled storage ring

    International Nuclear Information System (INIS)

    Wolski, Andrzej; Woodley, Mark D.

    2004-01-01

    The techniques of normal form analysis, well known in the literature, can be used to provide a straightforward characterization of linear betatron dynamics in a coupled lattice. Here, we consider both the beam distribution and the betatron oscillations in a storage ring. We find that the beta functions for uncoupled motion generalize in a simple way to the coupled case. Defined in the way that we propose, the beta functions remain well behaved (positive and finite) under all circumstances, and have essentially the same physical significance for the beam size and betatron oscillation amplitude as in the uncoupled case. Application of this analysis to the online modeling of the PEP-II rings is also discussed

  19. Applying field mapping refractive beam shapers to improve holographic techniques

    Science.gov (United States)

    Laskin, Alexander; Williams, Gavin; McWilliam, Richard; Laskin, Vadim

    2012-03-01

    Performance of various holographic techniques can be essentially improved by homogenizing the intensity profile of the laser beam with using beam shaping optics, for example, the achromatic field mapping refractive beam shapers like πShaper. The operational principle of these devices presumes transformation of laser beam intensity from Gaussian to flattop one with high flatness of output wavefront, saving of beam consistency, providing collimated output beam of low divergence, high transmittance, extended depth of field, negligible residual wave aberration, and achromatic design provides capability to work with several laser sources with different wavelengths simultaneously. Applying of these beam shapers brings serious benefits to the Spatial Light Modulator based techniques like Computer Generated Holography or Dot-Matrix mastering of security holograms since uniform illumination of an SLM allows simplifying mathematical calculations and increasing predictability and reliability of the imaging results. Another example is multicolour Denisyuk holography when the achromatic πShaper provides uniform illumination of a field at various wavelengths simultaneously. This paper will describe some design basics of the field mapping refractive beam shapers and optical layouts of their applying in holographic systems. Examples of real implementations and experimental results will be presented as well.

  20. A technique for aligning sextupole systems using beam optics

    International Nuclear Information System (INIS)

    Chao, Yu-Chiu.

    1992-03-01

    A technique for beam based alignment of sextupole system is developed exploiting the enhancement effect of orbit differences by the sextupoles. This technique can in principle be applied to sextupole or sextupole strings with controlled orbit pattern and BPM configurations. This paper will discuss the theoretical basis, special optimization considerations and expected accuracy. Application to the SLC final focus is also discussed

  1. Beam dynamics in rf guns and emittance correction techniques

    International Nuclear Information System (INIS)

    Serafini, L.

    1994-01-01

    In this paper we present a general review of beam dynamics in a laser-driven rf gun. The peculiarity of such an accelerating structure versus other conventional multi-cell linac structures is underlined on the basis of the Panofsky-Wenzel theorem, which is found to give a theoretical background for the well known Kim's model. A basic explanation for some proposed methods to correct rf induced emittance growth is also derived from the theorem. We also present three emittance correction techniques for the recovery of space-charge induced emittance growth, namely the optimum distributed disk-like bunch technique, the use of rf spatial harmonics to correct spherical aberration induced by space charge forces and the technique of emittance filtering by clipping the electron beam. The expected performances regarding the beam quality achievable with different techniques, as predicted by scaling laws and simulations, are analyzed, and, where available, compared to experimental results. (orig.)

  2. Proton-beam technique dates fine wine

    Science.gov (United States)

    Dumé, Belle

    2008-10-01

    Nuclear physicists in France have invented a way to authenticate the vintage of rare wine without needing a sommelier's keen nose or even a corkscrew. The technique, which involves firing high-energy protons at wine bottles, can determine how old the bottles are and even where they come from. The new method could help unmask counterfeit wines - a growing problem in the fine-wine industry, where a bottle can sell for thousands of Euros.

  3. Improved beam-energy calibration technique for heavy ion accelerators

    International Nuclear Information System (INIS)

    Ferrero, A.M.J.; Garcia, A.; Gil, Salvador

    1989-01-01

    A simple technique for beam energy calibration of heavy-ion accelerators is presented. A thin hydrogenous target was bombarded with 12 C and 19 F, and the energies of the protons knocked out, elastically were measured at several angles using two detectors placed at equal angles on opposite sides of the beam. The use of these two detectors cancels the largest errors due to uncertainties in the angle and position at which the beam hits the target. An application of this energy calibration method to an electrostatic accelerator is described and the calibration constant of the analyzing magnet was obtained with an estimated error of 0.4 (Author) [es

  4. Magnetically scanned proton therapy beams: rationales and techniques

    International Nuclear Information System (INIS)

    Jones, D.T.L.; Schreuder, A.N.

    2000-01-01

    Perhaps the most important advantages of beam scanning systems for proton therapy in comparison with conventional passive beam spreading systems are: (1) Intensity modulation and inverse planning are possible. (2) There is negligible reduction in the range of the beam. (3) Integral dose is reduced as dose conformation to the proximal edge of the lesion is possible. (4) In principle no field-specific modifying devices are required. (5) There is less activation of the surroundings. (6) Scanning systems axe almost infinitely flexible. The main disadvantages include: (1) Scanning systems are more complicated and therefore potentially less reliable and more dangerous. (2) The development of such systems is more demanding in terms of cost, time and manpower. (3) More stable beams are required. (4) Dose and beam position monitoring are more difficult. (5) The problems associated with patient and organ movement axe more severe. There are several techniques which can be used for scanning. For lateral beam spreading, circular scanning (wobbling) or linear scanning can be done. In the latter case the beam can be scanned continuously or in a discrete fashion (spot scanning). Another possibility is to undertake the fastest scan in one dimension (strip scanning) and translate the patient or the scanning magnet in the other dimension. Depth variation is achieved by interposing degraders in the beam (cyclotrons) or by changing the beam energy (synchrotrons). The aim of beam scanning is to deliver a predetermined dose at any point in the body. Special safety precautions must be taken because of the high instantaneous dose rates. The beam position and the dose delivered at each point must be accurately and redundantly determined. (author)

  5. Techniques for intense-proton-beam profile measurements

    International Nuclear Information System (INIS)

    Gilpatrick, J.D.

    1998-01-01

    In a collaborative effort with industry and several national laboratories, the Accelerator Production of Tritium (APT) facility and the Spallation Neutron Source (SNS) linac are presently being designed and developed at Los Alamos National Laboratory (LANL). The APT facility is planned to accelerate a 100-mA H + cw beam to 1.7 GeV and the SNS linac is planned to accelerate a 1- to 4-mA-average, H - , pulsed-beam to 1 GeV. With typical rms beam widths of 1- to 3-mm throughout much of these accelerators, the maximum average-power densities of these beams are expected to be approximately 30- and 1-MW-per-square millimeter, respectively. Such power densities are too large to use standard interceptive techniques typically used for acquisition of beam profile information. This paper summarizes the specific requirements for the beam profile measurements to be used in the APT, SNS, and the Low Energy Development Accelerator (LEDA)--a facility to verify the operation of the first 20-MeV section of APT. This paper also discusses the variety of profile measurement choices discussed at a recent high-average-current beam profile workshop held in Santa Fe, NM, and will present the present state of the design for the beam profile measurements planned for APT, SNS, and LEDA

  6. Vibration control in smart coupled beams subjected to pulse excitations

    Science.gov (United States)

    Pisarski, Dominik; Bajer, Czesław I.; Dyniewicz, Bartłomiej; Bajkowski, Jacek M.

    2016-10-01

    In this paper, a control method to stabilize the vibration of adjacent structures is presented. The control is realized by changes of the stiffness parameters of the structure's couplers. A pulse excitation applied to the coupled adjacent beams is imposed as the kinematic excitation. For such a representation, the designed control law provides the best rate of energy dissipation. By means of a stability analysis, the performance in different structural settings is studied. The efficiency of the proposed strategy is examined via numerical simulations. In terms of the assumed energy metric, the controlled structure outperforms its passively damped equivalent by over 50 percent. The functionality of the proposed control strategy should attract the attention of practising engineers who seek solutions to upgrade existing damping systems.

  7. Diagnostic studies of ion beam formation in inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Jenee L. [Iowa State Univ., Ames, IA (United States)

    2015-01-01

    This dissertation describes a variety of studies focused on the plasma and the ion beam in inductively coupled plasma mass spectrometry (ICP-MS). The ability to use ICP-MS for measurements of trace elements in samples requires the analytes to be efficiently ionized. Updated ionization efficiency tables are discussed for ionization temperatures of 6500 K and 7000 K with an electron density of 1 x 1015 cm-3. These values are reflective of the current operating parameters of ICP-MS instruments. Calculations are also discussed for doubly charged (M2+) ion formation, neutral metal oxide (MO) ionization, and metal oxide (MO+) ion dissociation for similar plasma temperature values. Ionization efficiency results for neutral MO molecules in the ICP have not been reported previously.

  8. Fastening, coupling and joining technique between diaspora and irredenta

    Science.gov (United States)

    Bauer, C.-O.

    1980-06-01

    The problem of eliminating the present divergence and shattering (diaspora) in the treatment of problems of the fastening, coupling, and joining technique on different technical branches is examined. It is shown that by an appropriate independence the fastening, coupling and joining techniques can recognize and consequently utilize the numerous performance reserves which are concealed by the present organization and action due to the lack of systematically tended works.

  9. Mechanical properties of micro-sized copper bending beams machined by the focused ion beam technique

    International Nuclear Information System (INIS)

    Motz, C.; Schoeberl, T.; Pippan, R.

    2005-01-01

    Micro-sized bending beams with thicknesses, t, from 7.5 down to 1.0 μm were fabricated with the focused ion beam technique from a copper single crystal with an {1 1 1} orientation. The beams were loaded with a nano-indenter and the force vs. displacement curves were recorded. A strong size effect was found where the flow stress reaches almost 1 GPa for the thinnest beams. A common strain gradient plasticity approach was used to explain the size effect. However, the strong t -1.14 dependence of the flow stress could not be explained by this model. Additionally, the combination of two other dislocation mechanisms is discussed: the limitation of available dislocation sources and a dislocation pile-up at the beam centre. The contribution of the pile-up stress to the flow stress gives a t -1 dependence, which is in good agreement with the experimental results

  10. The application of Lie algebra techniques to beam transport design

    International Nuclear Information System (INIS)

    Irwin, J.

    1990-01-01

    Using a final focus system for high-energy linear colliders as an example of a beam transport system, we illustrate for each element, and for the interplay of elements, the connection of Lie algebra techniques with usual optical analysis methods. Our analysis describes, through fourth order, the calculation and compensation of all important aberrations. (orig.)

  11. Ion beam techniques for analyzing polymers irradiated by ions

    International Nuclear Information System (INIS)

    Rickards, J.; Zironi, E.P.; Andrade, E.; Dominguez, B.

    1992-01-01

    In the study of the effects of ion beam irradiation of polymers very large doses can be administered in short times. Thousands of MGy can be produced in a small volume of a sample in a few minutes by bombarding with typical ion beam currents. For instance, in an experiment done to observe the effects of 750 keV proton irradiation PVC, using a collimator of 1 mm diameter, 1 μC of charge integration deposits a dose of 50 MGy. The use of ion beams also opens up the possibility of using the same beam for irradiation and for analysis of the effects, using the well known ion beam analysis techniques. PIXE allows the measurement of chlorine in PVC. Polymers containing fluorine can be measured with the resonant nuclear reaction (RNR) technique, which is specific only to certain elements. The amount of hydrogen in the sample and its profile can be obtained using energy recoil detection analysis (ERDA); carbon, oxygen, and nitrogen can be measured and profiled using Rutherford backscattering (RBS) and also using the (d,p) and (d, α) nuclear reactions (NR). Loss of mass is one effect that can be studied using these techniques. It was studied in two different polymers, PVC and CR-39, in order to determine carbon buildup during ion irradiation. It was concluded that carbon builds up following different mechanisms in these two materials, due to the different possibilities of forming volatile compounds. It is also suggested that CR-39 should be a good material for ion beam lithography. (author)

  12. Development of ion beam sputtering techniques for actinide target preparation

    International Nuclear Information System (INIS)

    Aaron, W.S.; Zevenbergen, L.A.; Adair, H.L.

    1985-01-01

    Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed. (orig.)

  13. Electron beam instabilities in unmagnetized plasmas via the Stieltjes transform (linear theory and nonlinear mode coupling)

    International Nuclear Information System (INIS)

    Krishan, S.

    2007-01-01

    The Stieltjes transform has been used in place of a more common Laplace transform to determine the time evolution of the self-consistent field (SCF) of an unmagnetized semi-infinite plasma, where the plasma electrons together with a primary and a low-density secondary electron beam move perpendicular to the boundary surface. The secondary beam is produced when the primary beam strikes the grid. Such a plasma system has been investigated by Griskey and Stanzel [M. C. Grisky and R. L. Stenzel, Phys. Rev. Lett. 82, 556 (1999)]. The physical phenomenon, observed in their experiment, has been named by them as ''secondary beam instability.'' The character of the instability observed in the experiment is not the same as predicted by the conventional treatments--the field amplitude does not grow with time. In the frequency spectrum, the theory predicts peak values in the amplitude of SCF at the plasma frequency of plasma and secondary beam electrons, decreasing above and below it. The Stieltjes transform for functions, growing exponentially in the long time limit, does not exist, while the Laplace transform technique gives only exponentially growing solutions. Therefore, it should be interesting to know the kind of solutions that an otherwise physically unstable plasma will yield. In the high-frequency limit, the plasma has been found to respond to any arbitrary frequency of the initial field differentiated only by the strength of the resulting SCF. The condition required for exponential growth in the conventional treatments, and the condition for maximum amplitude (with respect to frequency) in the present treatment, have been found to be the same. Nonlinear mode coupling between the modes excited by the plasma electrons and the low-density secondary beam gives rise to two frequency-dependent peaks in the field amplitude, symmetrically located about the much stronger peak due to the plasma electrons, as predicted by the experiment

  14. Source reconstruction using phase space beam summation technique

    International Nuclear Information System (INIS)

    Graubart, Gideon.

    1990-10-01

    In this work, the phase-space beam summation technique (PSBS), is applied to back propagation and inverse source problems. The PSBS expresses the field as a superposition of shifted and tilted beams. This phase space spectrum of beams is matched to the source distribution via an amplitude function which expresses the local spectrum of the source function in terms of a local Fourier transform. In this work, the emphasis is on the phase space processing of the data, on the information content of this data and on the back propagation scheme. More work is still required to combine this back propagation approach in a full, multi experiment inverse scattering scheme. It is shown that the phase space distribution of the data, computed via the local spectrum transform, is localized along lines that define the local arrival direction of the wave data. We explore how the choice of the beam width affects the compactification of this distribution, and derive criteria for choosing a window that optimizes this distribution. It should be emphasized that compact distribution implies fewer beams in the back propagation scheme and therefore higher numerical efficiency and better physical insight. Furthermore it is shown how the local information property of the phase space representation can be used to improve the performance of this simple back propagation problem, in particular with regard to axial resolution; the distance to the source can be determined by back propagating only the large angle phase space beams that focus on the source. The information concerning transverse distribution of the source, on the other hand, is contained in the axial phase space region and can therefore be determined by the corresponding back propagating beams. Because of the global nature of the plane waves propagators the conventional plane wave back propagation scheme does not have the same 'focusing' property, and therefore suffers from lack of information localization and axial resolution. The

  15. Optical fiber sensors fabricated by the focused ion beam technique

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Wang, Fei; Bang, Ole

    2012-01-01

    crystal fiber (PCF). Using this technique we fabricate a highly compact fiber-optic Fabry-Pérot (FP) refractive index sensor near the tip of fiber taper, and a highly sensitive in-line temperature sensor in PCF. We also demonstrate the potential of using FIB to selectively fill functional fluid......Focused ion beam (FIB) is a highly versatile technique which helps to enable next generation of lab-on-fiber sensor technologies. In this paper, we demonstrate the use application of FIB to precisely mill the fiber taper and end facet of both conventional single mode fiber (SMF) and photonic...

  16. Determination of the isomeric fraction in a postaccelerated radioactive ion beam using the coupled decay-chain equations

    CERN Document Server

    Ekstrom, A; Dijulio, D D; Cederkall, J; Van de Walle, J

    2010-01-01

    A method based on the coupled decay-chain equations for extracting the isotopic and the isomeric composition of a postaccelerated radioactive ion beam is presented and demonstrated on a data set from a Coulomb excitation experiment. This is the first attempt of analyzing the content of a postaccelerated radioactive ion beam using this technique. The beam composition is required for an absolute normalization of the measurement. The strength of the method, as compared to present online-based methods, lies in the determination of the isomeric fraction of a partially isomeric beam using all data accumulated during the experiment. We discuss the limitations and sensitivity of the method with respect to the gamma-ray detection efficiency and the accumulated flux. (C) 2010 Elsevier B.V. All rights reserved.

  17. New technique for levitating solid particles using a proton beam

    International Nuclear Information System (INIS)

    Misconi, N.Y.

    1996-01-01

    A new technique for levitating solid particles inside a vacuum chamber is developed using a proton beam. This new technique differs from the classical laser-levitation technique invented by Ashkin in that it does not heat up light-absorbing levitated particles to vaporization. This unique property of the method will make it possible to levitate real interplanetary dust particles in a vacuum chamber and study their spin-up dynamics in a ground-based laboratory. It is found that a flux of protons from a proton gun of ∼ 10 15 cm -2 sec -1 is needed to levitate a 10-mm particle. Confinement of the levitated particle can be achieved by a Z or θ pinch to create a gravity well, or by making the beam profile doughnut in shape. In levitating real interplanetary particles, two spin-up mechanisms can be investigated using this technique: one is the Paddack Effect and the other is a spin-up mechanism by the interaction of F-coronal dust with CMEs (Coronal Mass Ejections). The real interplanetary particles were collected by Brownie and associates (also known as the Brownie Particles) from the earth's upper atmosphere. (author)

  18. Ion beam analysis techniques applied to large scale pollution studies

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, D D; Bailey, G; Martin, J; Garton, D; Noorman, H; Stelcer, E; Johnson, P [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1994-12-31

    Ion Beam Analysis (IBA) techniques are ideally suited to analyse the thousands of filter papers a year that may originate from a large scale aerosol sampling network. They are fast multi-elemental and, for the most part, non-destructive so other analytical methods such as neutron activation and ion chromatography can be performed afterwards. ANSTO in collaboration with the NSW EPA, Pacific Power and the Universities of NSW and Macquarie has established a large area fine aerosol sampling network covering nearly 80,000 square kilometres of NSW with 25 fine particle samplers. This network known as ASP was funded by the Energy Research and Development Corporation (ERDC) and commenced sampling on 1 July 1991. The cyclone sampler at each site has a 2.5 {mu}m particle diameter cut off and runs for 24 hours every Sunday and Wednesday using one Gillman 25mm diameter stretched Teflon filter for each day. These filters are ideal targets for ion beam analysis work. Currently ANSTO receives 300 filters per month from this network for analysis using its accelerator based ion beam techniques on the 3 MV Van de Graaff accelerator. One week a month of accelerator time is dedicated to this analysis. Four simultaneous accelerator based IBA techniques are used at ANSTO, to analyse for the following 24 elements: H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Co, Zn, Br and Pb. The IBA techniques were proved invaluable in identifying sources of fine particles and their spatial and seasonal variations accross the large area sampled by the ASP network. 3 figs.

  19. Ion beam analysis techniques applied to large scale pollution studies

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, D.D.; Bailey, G.; Martin, J.; Garton, D.; Noorman, H.; Stelcer, E.; Johnson, P. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1993-12-31

    Ion Beam Analysis (IBA) techniques are ideally suited to analyse the thousands of filter papers a year that may originate from a large scale aerosol sampling network. They are fast multi-elemental and, for the most part, non-destructive so other analytical methods such as neutron activation and ion chromatography can be performed afterwards. ANSTO in collaboration with the NSW EPA, Pacific Power and the Universities of NSW and Macquarie has established a large area fine aerosol sampling network covering nearly 80,000 square kilometres of NSW with 25 fine particle samplers. This network known as ASP was funded by the Energy Research and Development Corporation (ERDC) and commenced sampling on 1 July 1991. The cyclone sampler at each site has a 2.5 {mu}m particle diameter cut off and runs for 24 hours every Sunday and Wednesday using one Gillman 25mm diameter stretched Teflon filter for each day. These filters are ideal targets for ion beam analysis work. Currently ANSTO receives 300 filters per month from this network for analysis using its accelerator based ion beam techniques on the 3 MV Van de Graaff accelerator. One week a month of accelerator time is dedicated to this analysis. Four simultaneous accelerator based IBA techniques are used at ANSTO, to analyse for the following 24 elements: H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Co, Zn, Br and Pb. The IBA techniques were proved invaluable in identifying sources of fine particles and their spatial and seasonal variations accross the large area sampled by the ASP network. 3 figs.

  20. An x-ray technique for precision laser beam synchronization

    International Nuclear Information System (INIS)

    Landen, O.L.; Lerche, R.A.; Hay, R.G.; Hammel, B.A.; Kalantar, D.; Cable, M.D.

    1994-01-01

    A new x-ray technique for recording the relative arrival times of multiple laser beams at a common target with better than ± 10 ps accuracy has been implemented at the Nova laser facility. 100 ps, 3ω Nova beam are focused to separate locations on a gold ribbon target viewed from the side. The measurement consists of using well characterized re-entrant x-ray streak cameras for 1-dimensional streaked imaging of the > 3 keV x-rays emanating from these isolated laser plasmas. After making the necessary correction for the differential laser, x-ray and electron transit times involved, timing offsets as low as ± 7 ps are resolved, and on subsequent shots, corrected for, verified and independently checked. This level of synchronization proved critical in meeting the power balance requirements for indirectly-driven pulse-shaped Nova implosions

  1. A new technique for ion beam tritium labelling

    International Nuclear Information System (INIS)

    Zhang Nianbao; Sheng Shugang; Yao Fuzeng

    1990-06-01

    An advanced technique, the ion beam tritium labelling method (IBTL), used for labelling proteins, peptides and other nonvolatile organic compounds is introduced. In this method the excited tritium ion beam is accelerated and then bombs a solid sample target in which tritium exchanging for hydrogen is taken place. The IBTL has been used for preparation of tritiated soybean trypsin inhibitor, ribonuclease A, elastin and pachyman etc. After purifing by dialysis, ion exchange chromatography and gel filtration, the tritiated proteins and polysaccharide were obtained with the specific activity over 37 GBq/mmol, the function of tritiated decomposition products was not found. The product was shown to have native biological activity. Amino acid analysis of tritiated protein showed that the relative specific radioactivities were higher for His., Tyr. and Phe. but lower for Val., Ile. and Ser

  2. Introduction to focused ion beams instrumentation, theory, techniques and practice

    CERN Document Server

    Giannuzzi, Lucille A

    2005-01-01

    The focused ion beam (FIB) instrument has experienced an intensive period of maturation since its inception. Numerous new techniques and applications have been brought to fruition, and over the past few years, the FIB has gained acceptance as more than just an expensive sample preparation tool. It has taken its place among the suite of other instruments commonly available in analytical and forensic laboratories, universities, geological, medical and biological research institutions, and manufacturing plants. Although the utility of the FIB is not limited to the preparation of specimens for subsequent analysis by other analytical techniques, it has revolutionized the area of TEM specimen preparation. The FIB has also been used to prepare samples for numerous other analytical techniques, and offers a wide range of other capabilities. While the mainstream of FIB usage remains within the semiconductor industry, FIB usage has expanded to applications in metallurgy, ceramics, composites, polymers, geology, art, bio...

  3. New diagnostic technique for Zeeman-compensated atomic beam slowing: technique and results

    NARCIS (Netherlands)

    Molenaar, P.A.; Straten, P. van der; Heideman, H.G.M.; Metcalf, H.

    1997-01-01

    We have developed a new diagnostic tool for the study of Zeeman-compensated slowing of an alkali atomic beam. Our time-of-flight technique measures the longitudinal veloc- ity distribution of the slowed atoms with a resolution below the Doppler limit of 30 cm/s. Furthermore, it can map

  4. Development of ion beam sputtering techniques for actinide target preparation

    Science.gov (United States)

    Aaron, W. S.; Zevenbergen, L. A.; Adair, H. L.

    1985-06-01

    Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of a minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity actinides in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed.

  5. VOC removal by microwave, electron beam and catalyst technique

    International Nuclear Information System (INIS)

    IghigeanuI, D.; Martin, D.; OproiuI, C.; Manaila, E.; Craciun, G.; Calinescu, I.; Zissulescu, E.

    2007-01-01

    A hybrid technique, developed for VOCs removal using microwave (MW) treatment, electron beam (EB) irradiation and catalyst method, is presented. Two hybrid laboratory installations, developed for the study of air pollution control by combined EB irradiation, MW irradiation and catalyst, are described. Air loaded with toluene was treated at different MW power levels, water content, flow rates, and different irradiation modes, separately and combined with MW and EB. Also, simultaneous EB and MW irradiation method was applied to SO 2 and NO x removal. Real synergy effects between EB induced NTP, MW induced NTP and catalysis can be observed

  6. Development of a micro-tomography technique by ion beams

    International Nuclear Information System (INIS)

    Moretto, Ph.; Michelet, C.

    1997-01-01

    The capability for an ion beam to penetrate easily the matter is an original feature for the nuclear microprobe analysis when compared to other techniques. Information in death of the sample can thus be obtained. Scanning Transmission Ion Microscopy (STIM) takes advantage of this capability to provide two dimensional maps of the sample thickness. Cross-sectional images of an object may be calculated from a set of STIM projections allowing the determination of the three-dimensional structure. This is the principle of STIM-Tomography. When PIXE analysis is carried out rotating the object under investigation, the elemental 3-D chemical distribution may also be elucidated at a microscopic scale. (authors)

  7. Accelerated Electron-Beam Formation with a High Capture Coefficient in a Parallel Coupled Accelerating Structure

    Science.gov (United States)

    Chernousov, Yu. D.; Shebolaev, I. V.; Ikryanov, I. M.

    2018-01-01

    An electron beam with a high (close to 100%) coefficient of electron capture into the regime of acceleration has been obtained in a linear electron accelerator based on a parallel coupled slow-wave structure, electron gun with microwave-controlled injection current, and permanent-magnet beam-focusing system. The high capture coefficient was due to the properties of the accelerating structure, beam-focusing system, and electron-injection system. Main characteristics of the proposed systems are presented.

  8. Rigid-flexible coupling dynamics of three-dimensional hub-beams system

    International Nuclear Information System (INIS)

    Liu Jinyang; Lu Hao

    2007-01-01

    In the previous research of the coupling dynamics of a hub-beam system, coupling between the rotational motion of hub and the torsion deformation of beam is not taken into account since the system undergoes planar motion. Due to the small longitudinal deformation, coupling between the rotational motion of hub and the longitudinal deformation of beam is also neglected. In this paper, rigid-flexible coupling dynamics is extended to a hub-beams system with three-dimensional large overall motion. Not only coupling between the large overall motion and the bending deformation, but also coupling between the large overall motion and the torsional deformation are taken into account. In case of temperature increase, the longitudinal deformation caused by the thermal expansion is significant, such that coupling between the large overall motion and the longitudinal deformation is also investigated. Combining the characteristics of the hybrid coordinate formulation and the absolute nodal coordinate formulation, the system generalized coordinates include the relative nodal displacement and the slope of each beam element with respect to the body-fixed frame of the hub, and the variables related to the spatial large overall motion of the hub and beams. Based on precise strain-displacement relation, the geometric stiffening effect is taken into account, and the rigid-flexible coupling dynamic equations are derived using velocity variational principle. Finite element method is employed for discretization. Simulation of a hub-beams system is used to show the coupling effect between the large overall motion and the torsional deformation as well as the longitudinal deformation. Furthermore, conservation of energy in case of free motion is shown to verify the formulation

  9. New approaches for investigating paintings by ion beam techniques

    International Nuclear Information System (INIS)

    Beck, L.; Viguerie, L. de; Walter, Ph.; Pichon, L.; Gutierrez, P.C.; Salomon, J.; Menu, M.; Sorieul, S.

    2010-01-01

    Up to now, among the IBA techniques, only PIXE has been used for analyzing paintings. However, quantitative PIXE analysis is sometimes difficult to interpret due to the layered structure, the presence of varnish and organic binder and, in some cases, discoloration of the pigments has been observed due to the interaction of the ion beam with the compounds. In order to improve the characterization of paintings, we propose some alternative experimental procedures. First of all, backscattering spectrometry (BS) and PIXE are simultaneously combined in order to collect complementary information such as layer thickness and organic compound quantification. The simultaneous PIXE and BS experiments also have the advantage of being able to analyze the same area in one experiment. This combination, implemented with an external beam, was directly applied on paintings and on painting cross-sections for the study of Italian Renaissance masterpieces. We have obtained valuable results not only on the pigment itself but also, for the first time, on the binder to pigment proportion which is not well documented in the ancient recipes. Moreover, in order to restrain beam damages due to the ion stopping power, we propose to analyze very thin painting cross-sections by a combination of PIXE-RBS and Scanning Transmission Ion Microscopy (STIM).

  10. Beam synchronous detection techniques for X-Ray spectroscopy

    International Nuclear Information System (INIS)

    Goujon, Gérard; Rogalev, Andreï; Goulon, José; Feite, Serge; Wilhelm, Fabrice

    2013-01-01

    The Photo diode detectors combine a set of properties that make them most appropriate, in particular, for X-ray Magnetic Circular Dichroism (XMCD) experiments. Under standard operating conditions, the detection bandwidth is primarily limited by the transimpedance preamplifier that converts the very low ac photocurrent into a voltage. On the other hand, when the photodiode is reverse biased, its finite shunt resistance will cause an undesirable, temperature dependent DC dark current. The best strategy to get rid of it is to use synchronous detection techniques. A classical implementation is based on the use of a chopper modulating the X-ray beam intensity at rather low frequencies (typically below 1 kHz). Here we report on the recent development of a fast Xray detection which has the capability to fully exploit the frequency structure of the ESRF X-ray beam (355 KHz and its harmonics). The availability of new wide band preamplifiers allowed us to extend the working frequency range up to a few MHz. A beam synchronous data processing was implemented in large FPGAs. Performances of the new detection system implemented at the ESRF beamline ID12 are illustrated with detection of the Fe K-edge XMCD spectra in garnets, using 4 bunches operation mode with modulation frequency of 1.4 MHz.

  11. New approaches for investigating paintings by ion beam techniques

    Science.gov (United States)

    Beck, L.; de Viguerie, L.; Walter, Ph.; Pichon, L.; Gutiérrez, P. C.; Salomon, J.; Menu, M.; Sorieul, S.

    2010-06-01

    Up to now, among the IBA techniques, only PIXE has been used for analyzing paintings. However, quantitative PIXE analysis is sometimes difficult to interpret due to the layered structure, the presence of varnish and organic binder and, in some cases, discoloration of the pigments has been observed due to the interaction of the ion beam with the compounds. In order to improve the characterization of paintings, we propose some alternative experimental procedures. First of all, backscattering spectrometry (BS) and PIXE are simultaneously combined in order to collect complementary information such as layer thickness and organic compound quantification. The simultaneous PIXE and BS experiments also have the advantage of being able to analyze the same area in one experiment. This combination, implemented with an external beam, was directly applied on paintings and on painting cross-sections for the study of Italian Renaissance masterpieces. We have obtained valuable results not only on the pigment itself but also, for the first time, on the binder to pigment proportion which is not well documented in the ancient recipes. Moreover, in order to restrain beam damages due to the ion stopping power, we propose to analyze very thin painting cross-sections by a combination of PIXE-RBS and Scanning Transmission Ion Microscopy (STIM).

  12. New approaches for investigating paintings by ion beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Beck, L., E-mail: Lucile.beck@cea.f [Centre de Recherche et de Restauration des Musees de France (C2RMF), CNRS-UMR 171, Palais du Louvre - Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Viguerie, L. de; Walter, Ph.; Pichon, L. [Centre de Recherche et de Restauration des Musees de France (C2RMF), CNRS-UMR 171, Palais du Louvre - Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Gutierrez, P.C. [Centro de Micro-Analisis de Materiales (CMAM), Universidad Autonoma de Madrid, Campus de Cantoblanco, E-28049 Madrid (Spain); Salomon, J.; Menu, M. [Centre de Recherche et de Restauration des Musees de France (C2RMF), CNRS-UMR 171, Palais du Louvre - Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Sorieul, S. [Centre d' Etudes Nucleaires de Bordeaux-Gradignan, IN2P3, UMR 5797, Universite de Bordeaux 1, Chemin du Solarium BP120, 33175 Gradignan Cedex (France)

    2010-06-15

    Up to now, among the IBA techniques, only PIXE has been used for analyzing paintings. However, quantitative PIXE analysis is sometimes difficult to interpret due to the layered structure, the presence of varnish and organic binder and, in some cases, discoloration of the pigments has been observed due to the interaction of the ion beam with the compounds. In order to improve the characterization of paintings, we propose some alternative experimental procedures. First of all, backscattering spectrometry (BS) and PIXE are simultaneously combined in order to collect complementary information such as layer thickness and organic compound quantification. The simultaneous PIXE and BS experiments also have the advantage of being able to analyze the same area in one experiment. This combination, implemented with an external beam, was directly applied on paintings and on painting cross-sections for the study of Italian Renaissance masterpieces. We have obtained valuable results not only on the pigment itself but also, for the first time, on the binder to pigment proportion which is not well documented in the ancient recipes. Moreover, in order to restrain beam damages due to the ion stopping power, we propose to analyze very thin painting cross-sections by a combination of PIXE-RBS and Scanning Transmission Ion Microscopy (STIM).

  13. Longitudinal coupling impedance imposed by a beam feedback in a synchrotron

    International Nuclear Information System (INIS)

    Ivanov, S.

    1997-01-01

    Commonly, a longitudinal beam feedback processes a slowly varying signal at zero intermediate frequency (a phase offset, an amplitude departure). Often, only a portion of the data confined in a picked-up band-pass beam signal is retained (like, say, in a purely phase feedback). Sometimes, a beam feedback employs different RF bands to pick up beam data and return a correction back to the beam. All the manipulations thus involved with signal spectra result in cross-talk between various beam-current and electric-field waves propagating along the orbit, which is shown to be described by an impedance matrix with, at most, three non-trivial elements per row. It is this matrix which gives the intuitive notion that a linear feedback is seen by a beam as an artificial coupling impedance controlled from the outside from a quantitative basis. This (impedance) approach has at least two plain advantages: (i) It allows one to mount the feedback's effect into the well-established theory of longitudinal coherent instabilities to use most of its inventory: beam transfer functions, threshold maps, handling of coupled-bunch motion, etc. (ii) The destabilizing effect of the beam environment, being available in standard terms of coupling impedances, is naturally taken into account since the early stages of feedback R and D. (orig.)

  14. Neutral atom beam technique enhances bioactivity of PEEK

    International Nuclear Information System (INIS)

    Khoury, Joseph; Kirkpatrick, Sean R.; Maxwell, Melissa; Cherian, Raymond E.; Kirkpatrick, Allen; Svrluga, Richard C.

    2013-01-01

    Polyetheretherketone (PEEK) is currently gaining popularity in orthopedic and spinal applications but has potential drawbacks in use. PEEK is biocompatible, similar in elasticity to bone, and radiolucent; however, it has been shown to be inert and does not integrate well with bone. Recent efforts have focused on increasing the bioactivity of PEEK by modifying the surface to improve the bone-implant interface. We have employed a novel Accelerated Neutral Atom Beam technique (ANAB) to enhance the bioactivity of PEEK. ANAB employs an intense beam of cluster-like packets of accelerated unbonded neutral argon (Ar) gas atoms. These beams are created by first producing a highly energetic Gas Cluster Ion Beam (GCIB) comprised of van der Waals bonded Ar atoms, then transferring energy to the clusters so as to cause release of most of the interatomic bonds, and finally deflecting away the remaining electrically charged cluster cores of still bonded atoms. We identified that ANAB treatment of PEEK results in nanometer scale surface modifications as well as increased surface hydrophilicity. Human osteoblasts seeded onto the surface of ANAB-treated PEEK exhibited enhanced growth as compared to control PEEK as evidenced by cell proliferation assays and microscopy. This increase in bioactivity resulted in cell proliferation levels comparable to native titanium. An in vivo study using a rat calvarial critical size defect model revealed enhanced osseointegration where bone tissue formation was evident only on the ANAB treated PEEK. Taken together, these data suggest that ANAB treatment of PEEK has the potential to enhance its bioactivity, resulting in bone formation and significantly decreasing osseointegration time of orthopedic and spinal implants

  15. Brazing techniques for side-coupled electron accelerator structures

    International Nuclear Information System (INIS)

    Hansborough, L.D.; Clark, W.L.; DePaula, R.A.; Martinez, F.A.; Roybal, P.L.; Wilkerson, L.C.; Young, L.M.

    1986-01-01

    The collaboration between the Los Alamos National Laboratory and the National Bureau of Standards (NBS), started in 1979, has led to the development of an advanced c-w microtron accelerator design. The four 2380-MHz NBS accelerating structures, containing a total of 184 accelerating cavities, have been fabricated and delivered. New fabrication methods, coupled with refinements of hydrogen-furnace brazing techniques described in this paper, allow efficient production of side-coupled structures. Success with the NBS RTM led to Los Alamos efforts on similar 2450-MHz accelerators for the microtron accelerator operated by the Nuclear Physics Department of the University of Illinois. Two accelerators (each with 17 cavities) have been fabricated; in 1986, a 45-cavity accelerator is being fabricated by private industry with some assistance from Los Alamos. Further private industry experience and refinement of the described fabrication techniques may allow future accelerators of this type to be completely fabricated by private industry

  16. A dynamic plasmonic manipulation technique assisted by phase modulation of an incident optical vortex beam

    International Nuclear Information System (INIS)

    Yuan, G H; Wang, Q; Tan, P S; Lin, J; Yuan, X-C

    2012-01-01

    A novel phase modulation method for dynamic manipulation of surface plasmon polaritons (SPPs) with a phase engineered optical vortex (OV) beam illuminating on nanoslits is experimentally demonstrated. Because of the unique helical phase carried by an OV beam, dynamic control of SPP multiple focusing and standing wave generation is realized by changing the OV beam’s topological charge constituent with the help of a liquid-crystal spatial light modulator. Measurement of SPP distributions with near-field scanning optical microscopy showed an excellent agreement with numerical predictions. The proposed phase modulation technique for manipulating SPPs features has seemingly dynamic and reconfigurable advantages, with profound potential for development of SPP coupling, routing, multiplexing and high-resolution imaging devices on plasmonic chips. (paper)

  17. Mechanical analysis of non-uniform bi-directional functionally graded intelligent micro-beams using modified couple stress theory

    Science.gov (United States)

    Bakhshi Khaniki, Hossein; Rajasekaran, Sundaramoorthy

    2018-05-01

    This study develops a comprehensive investigation on mechanical behavior of non-uniform bi-directional functionally graded beam sensors in the framework of modified couple stress theory. Material variation is modelled through both length and thickness directions using power-law, sigmoid and exponential functions. Moreover, beam is assumed with linear, exponential and parabolic cross-section variation through the length using power-law and sigmoid varying functions. Using these assumptions, a general model for microbeams is presented and formulated by employing Hamilton’s principle. Governing equations are solved using a mixed finite element method with Lagrangian interpolation technique, Gaussian quadrature method and Wilson’s Lagrangian multiplier method. It is shown that by using bi-directional functionally graded materials in nonuniform microbeams, mechanical behavior of such structures could be affected noticeably and scale parameter has a significant effect in changing the rigidity of nonuniform bi-directional functionally graded beams.

  18. Reducing beam shaper alignment complexity: diagnostic techniques for alignment and tuning

    Science.gov (United States)

    Lizotte, Todd E.

    2011-10-01

    Safe and efficient optical alignment is a critical requirement for industrial laser systems used in a high volume manufacturing environment. Of specific interest is the development of techniques to align beam shaping optics within a beam line; having the ability to instantly verify by a qualitative means that each element is in its proper position as the beam shaper module is being aligned. There is a need to reduce these types of alignment techniques down to a level where even a newbie to optical alignment will be able to complete the task. Couple this alignment need with the fact that most laser system manufacturers ship their products worldwide and the introduction of a new set of variables including cultural and language barriers, makes this a top priority for manufacturers. Tools and methodologies for alignment of complex optical systems need to be able to cross these barriers to ensure the highest degree of up time and reduce the cost of maintenance on the production floor. Customers worldwide, who purchase production laser equipment, understand that the majority of costs to a manufacturing facility is spent on system maintenance and is typically the largest single controllable expenditure in a production plant. This desire to reduce costs is driving the trend these days towards predictive and proactive, not reactive maintenance of laser based optical beam delivery systems [10]. With proper diagnostic tools, laser system developers can develop proactive approaches to reduce system down time, safe guard operational performance and reduce premature or catastrophic optics failures. Obviously analytical data will provide quantifiable performance standards which are more precise than qualitative standards, but each have a role in determining overall optical system performance [10]. This paper will discuss the use of film and fluorescent mirror devices as diagnostic tools for beam shaper module alignment off line or in-situ. The paper will also provide an overview

  19. Modification of PMMA/graphite nanocomposites through ion beam technique

    Science.gov (United States)

    Singhal, Prachi; Rattan, Sunita; Avasthi, Devesh Kumar; Tripathi, Ambuj

    2013-08-01

    Swift heavy ion (SHI) irradiation is a special technique for inducing physical and chemical modifications in bulk materials. In the present work, the SHI hs been used to prepare nanocomposites with homogeneously dispersed nanoparticles. The nanographite was synthesized from graphite using the intercalation-exfoliation method. PMMA Poly(methyl methacrylate)/graphite nanocomposites have been synthesized by in situ polymerization. The prepared PMMA/graphite nanocomposite films were irradiated with SHI irradiation (Ni ion beam, 80 MeV and C ion beam, 50 MeV) at a fluence of 1×1010 to 3×1012 ions/cm2. The nanocomposite films were characterized by scanning electron microscope (SEM) and were evaluated for their electrical and sensor properties. After irradiation, significant changes in surface morphology of nanocomposites were observed as evident from the SEM images, which show the presence of well-distributed nanographite platelets. The irradiated nanocomposites exhibit better electrical and sensor properties for the detection of nitroaromatics with marked improvement in sensitivity as compared with unirradiated nanocomposites.

  20. New diagnostic technique for Zeeman-compensated atomic beam slowing: technique and results

    OpenAIRE

    Molenaar, P.A.; Straten, P. van der; Heideman, H.G.M.; Metcalf, H.

    1997-01-01

    We have developed a new diagnostic tool for the study of Zeeman-compensated slowing of an alkali atomic beam. Our time-of-flight technique measures the longitudinal veloc- ity distribution of the slowed atoms with a resolution below the Doppler limit of 30 cm/s. Furthermore, it can map the position and velocity distribution of atoms in either ground hyperfine level inside the solenoid without any devices inside the solenoid. The technique reveals the optical pumping ef- fects, and shows in de...

  1. A new technique of ion beam tritium labelling

    International Nuclear Information System (INIS)

    Zhang Nianbao; Sheng Shugang; Yao Fuzeng

    1990-01-01

    In this paper a new technique is reported for tritium labelling of proteins, peptides and other nonvolatile organic compounds. A tritium ion beam is accelerated to bombard solid sample target for producing tritium exchange with hydrogen. The tritium labelling method has been applied to tritiated soybean trypsin inhibitor, ribonuclease A, elastin, pachyman and others totalled 11. After purifying by dialysis, ion exchange chromatography and gel filtration, the tritiated proteins and polysaccharide were obtained with specific activity over 37 GBq/mmol, without decomposition and with biological activity well preserved. By amino acid analysis of tritiated protein it was shown that the relative specific radioactivities for His., Tyr. and Phe. residues were higher while those for Val., Ile. and Ser. residues were lower

  2. Optical and mechanical design of beam-target coupling sensor

    International Nuclear Information System (INIS)

    Wang Liquan; Li Tian'en; Feng Bin; Xiang Yong; Li Keyu; Zhong Wei; Liu Guodong

    2012-01-01

    A sensor based on conjugate principle has been designed for matching the light beams and the target in inertial confinement fusion. It can avoid the direct illumination of the simulation collimating light on the target under test in targeting processes. This paper introduces the optical and mechanical design of the sensor, according to its design functions and working principle. The resolution of the optical images obtained in experiments reaches 6 μm and the beam-target matching accuracy is 8.8 μm. The sensor has been successfully applied to the Shenguang-Ⅲ facility. Statistical analyses of the four-hole CH target images derived with pinhole camera shows that the targeting accuracy of the facility is better than 25 μm, satisfying the design requirements. (authors)

  3. Dynamics of beam pair coupled by visco-elastic interlayer

    Czech Academy of Sciences Publication Activity Database

    Náprstek, Jiří; Hračov, Stanislav

    2015-01-01

    Roč. 9, č. 2 (2015), s. 127-140 ISSN 1802-680X R&D Projects: GA ČR(CZ) GP13-41574P; GA ČR(CZ) GA15-01035S Institutional support: RVO:68378297 Keywords : double-beam dynamics * visco-elastic interlayer * kinematic damping Subject RIV: JM - Building Engineering http://www.kme.zcu.cz/acm/acm/article/view/292

  4. Multi-beam backscatter image data processing techniques employed to EM 1002 system

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, W.A.; Chakraborty, B.

    to compensate outer-beam backscatter strength data in such a way that the effect of angular backscatter strength is removed. In this work we have developed backscatter data processing techniques for EM1002 multi-beam system...

  5. Geometric beam coupling impedance of LHC secondary collimators

    Science.gov (United States)

    Frasciello, Oscar; Tomassini, Sandro; Zobov, Mikhail; Salvant, Benoit; Grudiev, Alexej; Mounet, Nicolas

    2016-02-01

    The High Luminosity LHC project is aimed at increasing the LHC luminosity by an order of magnitude. One of the key ingredients to achieve the luminosity goal is the beam intensity increase. In order to keep beam instabilities under control and to avoid excessive power losses a careful design of new vacuum chamber components and an improvement of the present LHC impedance model are required. Collimators are among the major impedance contributors. Measurements with beam have revealed that the betatron coherent tune shifts were higher by about a factor of 2 with respect to the theoretical predictions based on the LHC impedance model up to 2012. In that model the resistive wall impedance has been considered as the dominating impedance contribution for collimators. By carefully simulating also their geometric impedance we have contributed to the update of the LHC impedance model, reaching also a better agreement between the measured and simulated betatron tune shifts. During the just ended LHC Long Shutdown I (LSI), TCS/TCT collimators were replaced by new devices embedding BPMs and TT2-111R ferrite blocks. We present here preliminary estimations of their broad-band impedance, showing that an increase of about 20% is expected in the kick factors with respect to previous collimators without BPMs.

  6. Techniques for heavy-ion coupled-channels calculations. I. Long-range Coulomb coupling

    International Nuclear Information System (INIS)

    Rhoades-Brown, M.; Macfarlane, M.H.; Pieper, S.C.

    1980-01-01

    Direct-reaction calculations for heavy ions require special computational techniques that take advantage of the physical peculiarities of heavy-ion systems. This paper is the first of a series on quantum-mechanical coupled-channels calculations for heavy ions. It deals with the problems posed by the long range of the Coulomb coupling interaction. Our approach is to use the Alder-Pauli factorization whereby the channel wave functions are expressed as products of Coulomb functions and modulating amplitudes. The equations for the modulating amplitudes are used to integrate inwards from infinity to a nuclear matching radius ( approx. = 20 fm). To adequate accuracy, the equations for the amplitudes can be reduced to first order and solved in first Born approximation. The use of the Born approximation leads to rapid recursion relations for the solutions of the Alder-Pauli equations and hence to a great reduction in computational labor. The resulting coupled-channels Coulomb functions can then be matched in the usual way to solutions of the coupled radial equations in the interior region of r space. Numerical studies demonstrate the reliability of the various techniques introduced

  7. An efficient coupled polynomial interpolation scheme for shear mode sandwich beam finite element

    Directory of Open Access Journals (Sweden)

    Litesh N. Sulbhewar

    Full Text Available An efficient piezoelectric sandwich beam finite element is presented here. It employs the coupled polynomial field interpolation scheme for field variables which incorporates electromechanical coupling at interpolation level itself; unlike conventional sandwich beam theory (SBT based formulations available in the literature. A variational formulation is used to derive the governing equations, which are used to establish the relationships between field variables. These relations lead to the coupled polynomial field descriptions of variables, unlike conventional SBT formulations which use assumed independent polynomials. The relative axial displacement is expressed only by coupled terms containing contributions from other mechanical and electrical variables, thus eliminating use of the transverse displacement derivative as a degree of freedom. A set of coupled shape function based on these polynomials has shown the improvement in the convergence characteristics of the SBT based formulation. This improvement in the performance is achieved with one nodal degree of freedom lesser than the conventional SBT formulations.

  8. Ion beam analysis and spectrometry techniques for Cultural Heritage studies

    International Nuclear Information System (INIS)

    Beck, L.

    2013-01-01

    The implementation of experimental techniques for the characterisation of Cultural heritage materials has to take into account some requirements. The complexity of these past materials requires the development of new techniques of examination and analysis, or the transfer of technologies developed for the study of advanced materials. In addition, due to precious aspect of artwork it is also necessary to use the non-destructive methods, respecting the integrity of objects. It is for this reason that the methods using radiations and/or particles play a important role in the scientific study of art history and archaeology since their discovery. X-ray and γ-ray spectrometry as well as ion beam analysis (IBA) are analytical tools at the service of Cultural heritage. This report mainly presents experimental developments for IBA: PIXE, RBS/EBS and NRA. These developments were applied to the study of archaeological composite materials: layered materials or mixtures composed of organic and non-organic phases. Three examples are shown: evolution of silvering techniques for the production of counterfeit coinage during the Roman Empire and in the 16. century, the characterization of composites or mixed mineral/organic compounds such as bone and paint. In these last two cases, the combination of techniques gave original results on the proportion of both phases: apatite/collagen in bone, pigment/binder in paintings. Another part of this report is then dedicated to the non-invasive/non-destructive characterization of prehistoric pigments, in situ, for rock art studies in caves and in the laboratory. Finally, the perspectives of this work are presented. (author) [fr

  9. Effect of transients on the beam in the Superconducting Supercollider Coupled-Cavity Linac

    International Nuclear Information System (INIS)

    Young, L.M.; Nath, S.

    1992-01-01

    Each module of the Superconducting Super Collider (SSC) Coupled-Cavity Linac (CCL) consists of eight tanks (10 accelerating cells each) coupled with bridge couplers. The radio frequency (rf) power drive is in the center of the module at the bridge coupler between the fourth and fifth tanks. In this simulation of the beam dynamics, the rf power is turned on 10 μs before the beam is turned on. This time lapse allows the fields to build up and stabilize before they are required by the beam. When the beam is turned on, the beam loading causes the fields to change. This transient state of the fields together with their effect on the beam is presented. A model has been developed to calculate field distribution throughout the module as a function of time. Beam dynamics simulations were run with the results of this model at several times during the beam pulse. An estimate of the effect of the transients is given by the results of these simulations

  10. Electron beam gun with kinematic coupling for high power RF vacuum devices

    Science.gov (United States)

    Borchard, Philipp

    2016-11-22

    An electron beam gun for a high power RF vacuum device has components joined by a fixed kinematic coupling to provide both precise alignment and high voltage electrical insulation of the components. The kinematic coupling has high strength ceramic elements directly bonded to one or more non-ductile rigid metal components using a high temperature active metal brazing alloy. The ceramic elements have a convex surface that mates with concave grooves in another one of the components. The kinematic coupling, for example, may join a cathode assembly and/or a beam shaping focus electrode to a gun stem, which is preferably composed of ceramic. The electron beam gun may be part of a high power RF vacuum device such as, for example, a gyrotron, klystron, or magnetron.

  11. arXiv Bench Measurements and Simulations of Beam Coupling Impedance

    CERN Document Server

    Niedermayer, Uwe

    After a general introduction, the basic principles of wake-field and beamcoupling- impedance computations are explained. This includes time domain, frequency domain, and methods that do not include excitations by means of a particle beam. The second part of this paper deals with radio frequency bench measurements of beam coupling impedances. The general procedure of the wire measurement is explained, and its features and limitations are discussed.

  12. MODELING AND ANALYSIS OF COUPLED FLEXURAL-TORSIONAL SPINNING BEAMS WITH UNSYMMETRICAL CROSS SECTIONS

    OpenAIRE

    Wang, Jie; Li, Dongxu; Jiang, Jianping

    2017-01-01

    The structural modeling and dynamic properties of a spinning beam with an unsymmetrical cross section are studied. Due to the eccentricity and spinning, transverse deflections along the two principal directions and the torsional motion about the longitudinal axis are coupled. The structural model of the beam is established based on the Hamilton principle and by incorporating the torsional inertia. Moreover, because of its significant influence on characteristics for the non-circular cross-sec...

  13. Effects of underwater turbulence on laser beam propagation and coupling into single-mode optical fiber.

    Science.gov (United States)

    Hanson, Frank; Lasher, Mark

    2010-06-01

    We characterize and compare the effects of turbulence on underwater laser propagation with theory. Measurements of the coupling efficiency of the focused beam into a single-mode fiber are reported. A simple tip-tilt control system, based on the position of the image centroid in the focal plane, was shown to maintain good coupling efficiency for a beam radius equal to the transverse coherence length, r(0). These results are relevant to high bandwidth communication technology that requires good spatial mode quality.

  14. All-optical optoacoustic microscopy based on probe beam deflection technique

    Directory of Open Access Journals (Sweden)

    Saher M. Maswadi

    2016-09-01

    Full Text Available Optoacoustic (OA microscopy using an all-optical system based on the probe beam deflection technique (PBDT for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii undistorted coupling of acoustic waves to the detector without the need for separation of the optical and acoustic paths, (iii high sensitivity and (iv ultrawide bandwidth. Because of the unimpeded optical path in PBDT, diffraction-limited lateral resolution can be readily achieved. The sensitivity of the current PBDT sensor of 22 μV/Pa and its noise equivalent pressure (NEP of 11.4 Pa are comparable with these parameters of the optical micro-ring resonator and commercial piezoelectric ultrasonic transducers. Benefits of the present prototype OA microscope were demonstrated by successfully resolving micron-size details in histological sections of cardiac muscle.

  15. All-optical optoacoustic microscopy based on probe beam deflection technique.

    Science.gov (United States)

    Maswadi, Saher M; Ibey, Bennett L; Roth, Caleb C; Tsyboulski, Dmitri A; Beier, Hope T; Glickman, Randolph D; Oraevsky, Alexander A

    2016-09-01

    Optoacoustic (OA) microscopy using an all-optical system based on the probe beam deflection technique (PBDT) for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i) efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii) undistorted coupling of acoustic waves to the detector without the need for separation of the optical and acoustic paths, (iii) high sensitivity and (iv) ultrawide bandwidth. Because of the unimpeded optical path in PBDT, diffraction-limited lateral resolution can be readily achieved. The sensitivity of the current PBDT sensor of 22 μV/Pa and its noise equivalent pressure (NEP) of 11.4 Pa are comparable with these parameters of the optical micro-ring resonator and commercial piezoelectric ultrasonic transducers. Benefits of the present prototype OA microscope were demonstrated by successfully resolving micron-size details in histological sections of cardiac muscle.

  16. Techniques for slow positron beam generation and the applications

    International Nuclear Information System (INIS)

    Okada, Sohei

    1994-01-01

    Slow positron beams have been expected to be a powerful tool for observation of nature in wide range of research fields from materials science to basic physics, chemistry and biology. In this paper, at first, the beam technology is reviewed, which includes the positron generation, the transformation to slow positron beams and the beam manipulation such as beam stretching, bunching and brightness enhancement. Next, the present status of the slow positron beam applications to a variety of fields is demonstrated in terms of special characteristics of positron, that is, depth controllability, surface sensitivity, unique ionization channels and elemental anti-particle properties. Finally, prospects to produce intense slow positron beams are described. (author) 65 refs

  17. Perturbation treatment of the longitudinal coupling impedance of a toroidal beam tube

    International Nuclear Information System (INIS)

    Hahn, H.; Tepikian, S.

    1991-01-01

    A simple analytical expression for the longitudinal coupling impedance of a toroidal beam tube below the resonance region has been derived by expanding the electromagnetic fields of the toroidal beam tube in a power series in curvature and substituting directly into Maxwell's equations. The resulting expression consists of the impedance of the straight beam pipe plus a correction terms due to the curvature. It has been verified that this result gives excellent agreement to the exact solution below the first resonance. 5 refs., 2 figs., 3 tabs

  18. Measuring a narrow Bessel beam spot by scanning a charge-coupled device (CCD) pixel

    International Nuclear Information System (INIS)

    Tiwari, S K; Ram, S P; Jayabalan, J; Mishra, S R

    2010-01-01

    By scanning a charge-coupled device (CCD) camera transverse to the beam axis and observing the variation in counts on a marked pixel, we demonstrate that we can measure a laser beam spot size smaller than the size of the CCD-pixel. We find this method particularly attractive for measuring the size of central spot of a Bessel beam, for which the established scanning knife-edge method does not work appropriately because of the large contribution of the rings surrounding the central spot to the signal

  19. Analytic modeling, simulation and interpretation of broadband beam coupling impedance bench measurements

    Energy Technology Data Exchange (ETDEWEB)

    Niedermayer, U., E-mail: niedermayer@temf.tu-darmstadt.de [Institut für Theorie Elektromagnetischer Felder (TEMF), Technische Universität Darmstadt, Schloßgartenstraße 8, 64289 Darmstadt (Germany); Eidam, L. [Institut für Theorie Elektromagnetischer Felder (TEMF), Technische Universität Darmstadt, Schloßgartenstraße 8, 64289 Darmstadt (Germany); Boine-Frankenheim, O. [Institut für Theorie Elektromagnetischer Felder (TEMF), Technische Universität Darmstadt, Schloßgartenstraße 8, 64289 Darmstadt (Germany); GSI Helmholzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt (Germany)

    2015-03-11

    First, a generalized theoretical approach towards beam coupling impedances and stretched-wire measurements is introduced. Applied to a circular symmetric setup, this approach allows to compare beam and wire impedances. The conversion formulas for TEM scattering parameters from measurements to impedances are thoroughly analyzed and compared to the analytical beam impedance solution. A proof of validity for the distributed impedance formula is given. The interaction of the beam or the TEM wave with dispersive material such as ferrite is discussed. The dependence of the obtained beam impedance on the relativistic velocity β is investigated and found as material property dependent. Second, numerical simulations of wakefields and scattering parameters are compared. The applicability of scattering parameter conversion formulas for finite device length is investigated. Laboratory measurement results for a circularly symmetric test setup, i.e. a ferrite ring, are shown and compared to analytic and numeric models. The optimization of the measurement process and error reduction strategies are discussed.

  20. Application of a transverse phase-space measurement technique for high-brightness, H- beams to the GTA H- beam

    International Nuclear Information System (INIS)

    Johnson, K.F.; Garcia, R.C.; Rusthoi, D.P.; Sander, O.R.; Sandoval, D.P.; Shinas, M.A.; Smith, M.; Yuan, V.W.; Connolly, R.C.

    1995-01-01

    The Ground Test Accelerator (GTA) had the objective Of Producing a high-brightness, high-current H-beam. The major components were a 35 keV injector, a Radio Frequency Quadrupole (RFQ), an intertank matching section (IMS), and a drift tube linac (DTL), consisting of 10 modules. A technique for measuring the transverse phase-space of high-power density beams has been developed and tested. This diagnostic has been applied to the GTA H-beam. Experimental results are compared to the slit and collector technique for transverse phase-space measurements and to simulations

  1. Probing WWγ and WWγγ couplings with high energy photon beams

    International Nuclear Information System (INIS)

    Choi, S.Y.; Schrempp, F.

    1992-01-01

    The potential of a 500 GeV 'Next Linear e + e - Collider' (NLC) for probing anomalous WWγ and WWγγ couplings in the γ(γ) mode is investigated. The γe - →W - ν and the γγ→W + W - processes are studied. Differential cross sections are given for polarized and unpolarized beams. CP violating couplings are also discussed. (K.A.) 13 refs., 6 figs

  2. Terahertz Quantum Cascade Laser With Efficient Coupling and Beam Profile

    Science.gov (United States)

    Chattopadhyay, Goutam; Kawamura, Jonathan H.; Lin, Robert H.; Williams, Benjamin

    2012-01-01

    Quantum cascade lasers (QCLs) are unipolar semiconductor lasers, where the wavelength of emitted radiation is determined by the engineering of quantum states within the conduction band in coupled multiple-quantum-well heterostructures to have the desired energy separation. The recent development of terahertz QCLs has provided a new generation of solid-state sources for radiation in the terahertz frequency range. Terahertz QCLs have been demonstrated from 0.84 to 5.0 THz both in pulsed mode and continuous wave mode (CW mode). The approach employs a resonant-phonon depopulation concept. The metal-metal (MM) waveguide fabrication is performed using Cu-Cu thermo-compression bonding to bond the GaAs/AlGaAs epitaxial layer to a GaAs receptor wafer.

  3. Single beam collective effects in FCC-ee due to beam coupling impedance

    CERN Document Server

    Belli, Eleonora; Persichelli, Serena; Zobov, Mikhail

    2016-01-01

    The Future Circular Collider study, hosted by CERN to design post-LHC particle accelerator options in a worldwide context, is focused on proton-proton high-energy and electron-positron high-luminosity frontier machines. This new accelerator complex represents a great challenge under several aspects, which involve R&D on beam dynamics and new technologies. One very critical point in this context is represented by collective effects, generated by the interaction of the beam with self-induced electromagnetic fields, called wake fields, which could produce beam instabilities, thus reducing the machines performance and limiting the maximum stored current. It is therefore very important to be able to predict these effects and to study in detail potential solutions to counteract them. In this paper the resistive wall and some other important geometrical sources of impedance for the FCC electron-positron accelerator are identified and evaluated, and their impact on the beam dynamics, which in some cases could lea...

  4. Single beam collective effects in FCC-ee due to beam coupling impedance

    CERN Document Server

    Belli, Eleonora

    2016-01-01

    The Future Circular Collider study, hosted by CERN to design post-LHC particle accelerator options in a worldwide context, is focused on proton-proton high-energy and electron-positron high-luminosity frontier machines. This new accelerator complex represents a great challenge under several aspects, which involve R&D on beam dynamics and new technologies. One very critical point in this context is represented by collective effects, generated by the interaction of the beam with self-induced electromagnetic fields, called wake fields, which could produce beam instabilities, thus reducing the machines performance and limiting the maximum stored current. It is therefore very important to be able to predict these effects and to study in detail potential solutions to counteract them. In this paper the resistive wall and some other important geometrical sources of impedance for the FCC electron-positron accelera- tor are identified and evaluated, and their impact on the beam dynamics, which in some cases could l...

  5. The effect of CFRP on retrofitting of damaged HSRC beams using AE technique

    Science.gov (United States)

    Soffian Noor, M. S.; Noorsuhada, M. N.

    2017-12-01

    This paper presents the effect of carbon fibre reinforced polymer (CFRP) on retrofitted high strength reinforced concrete (HSRC) beams using acoustic emission (AE) technique. Two RC beam parameters were prepared. The first was the control beam which was undamaged HSRC beam. The second was the damaged HSRC beam retrofitted with CFRP on the soffit. The main objective of this study is to assess the crack modes of HSRC beams using AE signal strength. The relationship between signal strength, load and time were analysed and discussed. The crack pattern observed from the visual observation was also investigated. HSRC beam retrofitted with CFRP produced high signal strength compared to control beam. It demonstrates the effect of the AE signal strength for interpretation and prediction of failure modes that might occur in the beam specimens.

  6. Coupling analysis of the target temperature and thermal stress due to pulsed ion beam

    International Nuclear Information System (INIS)

    Yan Jie; Liu Meng; Lin Jufang; An Li; Long Xinggui

    2013-01-01

    Background: Target temperature has an important effect on the target life for the sealed neutron generator without cooling system. Purpose: To carry out the thermal-mechanical coupling analysis of the film-substrate target bombarded by the pulsed ion beam. Methods: The indirect coupling Finite Element Method (FEM) with a 2-dimensional time-space Gaussian axisymmetric power density as heat source was used to simulate the target temperature and thermal stress fields. Results: The effects of the target temperature and thermal stress fields under difference pulse widths and beam sizes were analyzed in terms of the FEM results. Conclusions: Combining with the temperature requirement and the thermal stress inducing film thermal mechanical destruction effect of the sealed neutron generator film-substrate targets, an optimized pulsed ion beam work status was proposed. (authors)

  7. Some techniques to improve time structure of slow extracted beam

    International Nuclear Information System (INIS)

    Shoji, Y.; Sato, H.; Toyama, T.; Marutsuka, K.; Sueno, T.; Mikawa, K.; Ninomiya, S.; Yoshii, M.

    1992-01-01

    In order to improve the time structure of slow extracted beam spill for the KEK 12GeV PS, the spill control system has been upgraded by adding feed forward signal to feedback signal. Further, the wake field in the RF cavity has been cancelled by the beam bunch signal to reduce the re-bunch effect during extraction period. (author)

  8. Novel non-intercepting diagnostic techniques for low-emittance relativistic electron beams

    International Nuclear Information System (INIS)

    Moran, M.J.; Chang, B.

    1988-01-01

    Relativistic electron beams are being generated with emittances low enough that diffraction radiation can be used for beam diagnostics. Techniques based on diffraction radiation can be used to measure the beam transverse momentum distribution and to measure the transverse spatial distribution. The radiation is intense and can be in the visible spectral region where optical diagnostic techniques can be used to maximum advantage. 4 refs. 3 figs

  9. Development of a computerized tomographic system based on the FAN-BEAM technique

    International Nuclear Information System (INIS)

    Junqueira, M.M.; Santos, C.A.C.; Borges, J.C.

    1986-01-01

    The Nuclear Instrumentation Laboratory, at COPPE/UFRJ, concentrates its researches in the development of computerized tomographic systems, looking for applications in industrial and medical non destructive analysing techniques. In this work we have projected and constructed a tomographic prototype, based on the FAN-BEAM technique for irradiating the object under analysis. An algorithm previously developed to analyse parallel beams, was modified and adapted to the FAN-BEAM geometry. (Author) [pt

  10. Coupling between eddy current and deflection in cantilevered beams in magnetic fields

    International Nuclear Information System (INIS)

    Hua, T.Q.

    1986-01-01

    Experiments were performed to investigate the coupling between eddy currents and deflection in cantilevered beams in longitudinal and transverse magnetic fields. This coupling effect reduces the current, deflection, and material stress to levels far less severe than would be predicted if coupling is disregarded. The experiments were conducted using the FELIX (Fusion ELectromagnetic Induction experiment) facility at the Argonne National Laboratory. The beams, which provide a simple model for the limiter blades in a tokamak fusion reactor, are subjected to crossed time-varying and constant magnetic fields. The time-varying field simulates the decaying field during a plasma disruption and the constant field models the toroidal field. Several test pieces are employed to allow variations in thicknesses and mechanical and electrical properties. Various magnetic field levels and decay time constants of time-varying are used to study the extent of the coupling from weak to strong coupling. The ratios of constant field to time-varying field are kept in the range from 10:1 to 20:1 as would be appropriate to tokamak limiters. Major parameters measured as functions of time are beam deflection, measured with an electro-optical device; total circulating current, measured with a Rogowski coil; strain recorded by strain gauges; and magnetic fields measured with Hall probes

  11. The status and new trends of ion beam induced charge technique

    International Nuclear Information System (INIS)

    Lu Rongrong; Qiu Huiyuan; Zhu Dezhang

    2002-01-01

    Ion beam induced charge technique (IBIC) with low beam current (fA level) and high efficiency is a new development of nuclear microscopy. It has been widely applied to the fields of semiconductor and microelectronic materials. The principle and the experimental method of the IBIC technique were described and reviewed its status and new trends were reviewed

  12. A wide band slot-coupled beam sensing electrode for the advanced light source

    International Nuclear Information System (INIS)

    Hinkson, J.; Rex, K.

    1991-05-01

    Stripline electrodes (traveling wave electrodes, directional couplers) are commonly used in particle accelerators as beam pickups and kickers. The longitudinally symmetric stripline has a constant beam coupling impedance as a function of length and has a characteristic magnitude sin(x) amplitude response in the frequency domain. An experimentally tapered stripline provides nearly constant coupling impedance vs. frequency and yields superior frequency-domain performance. In practice it is difficult to construct either of these devices for broad-band performance because of the transition from coaxial to stripline geometry. We report on the construction of an exponentially-tapered, slot-coupled ''stripline'' which was relatively easy to construct and has the desired frequency response. 2 refs., 6 figs

  13. Stability of longitudinal modes in a bunched beam with mode coupling

    International Nuclear Information System (INIS)

    Satoh, K.

    1981-06-01

    In this paper we study a longitudinal coherent bunch instability in which the growth time is comparable to or less than the period of synchrotron oscillations. Both longitudinal and transverse bunch instabilities have been studied. In most treatments, however, the coherent force is assumed to be small and is treated as a perturbation compared with the synchrotron force. This makes the problem simpler because an individual synchrotron mode is decoupled. As bunch current increases, the coherent force is no longer small and the mode frequency shift becomes significant compared with the synchrotron frequency. Therefore in this case it is necessary to include coupling of the synchrotron modes. Recently a fast blow-up instability which comes from mode coupling was studied. Their method is to derive a dispersion relation for a bunched beam using the Vlasov equation and to analyze it as in a coasting beam. They showed that if mode coupling is included the Vlasov equation predicts a fast microwave instability with a stability condition similar to that for a coasting beam. In this paper we will partly follow their method and present a formalism which includes coupling between higher-order radial modes as well as coupling between synchrotron modes. The formalism is considered to be generalization of the Sacherer formalism without mode coupling. This theory predicts that instability is induced not only by coupling between different synchrotron modes, but also by coupling between positive and negative modes, since negative synchrotron modes are included in the theory in a natural manner. This formalism is to be used for a Gaussian bunch and a parabolic bunch, and is also useful for transverse problems

  14. Electromagnetic Coupling Between High Intensity LHC Beams and the Synchrotron Radiation Monitor Light Extraction System

    CERN Document Server

    Andreazza, W; Bravin, E; Caspers, F; Garlasch`e, M; Gras, J; Goldblatt, A; Lefevre, T; Jones, R; Metral, E; Nosych, A; Roncarolo_, F; Salvant, B; Trad, G; Veness, R; Vollinger, C; Wendt, M

    2013-01-01

    The CERN LHC is equipped with two Synchrotron Radiation Monitor (BSRT) systems used to characterise transverse and longitudinal beam distributions. Since the end of the 2011 LHC run the light extraction system, based on a retractable mirror, has suffered deformation and mechanical failure that is correlated to the increase in beam intensity. Temperature probes have associated these observations to a strong heating of the mirror support with a dependence on the longitudinal bunch length and shape, indicating the origin as electromagnetic coupling between the beam and the structure. This paper combines all this information with the aim of characterising and improving the system in view of its upgrade during the current LHC shutdown. Beam-based observations are presented along with electromagnetic and thermomechanical simulations and complemented by laboratory measurements, including the study of the RF properties of different mirror bulk and coating materials.

  15. Characteristic analysis of coupled transmission lines in stripline-type beam position monitor

    International Nuclear Information System (INIS)

    Suwada, T.

    2013-01-01

    Signal transmission characteristics in stripline electrodes of a stripline-type beam position monitor (BPM) are discussed on the basis of a coupled-mode analysis in electromagnetically coupled transmission lines. The physical prospect in the calibration procedure of stripline electrodes is improved in terms of signal transmission characteristics in the frequency domain. It is demonstrated that in the signal transmission with electromagnetic coupling between the stripline electrodes, the magnetic- and electric-coupling parameters play an important role depending upon the spatial configuration and mechanical structure of the stripline electrodes. In this report, a theoretical analysis, and experimental investigation into signal transmission characteristics and performance in a standard stripline-type BPM are described in detail on the basis of a coupled-mode analysis in uniform transmission lines

  16. An isodose shift technique for obliquely incident electron beams

    International Nuclear Information System (INIS)

    Ulin, K.; Sternick, E.S.

    1989-01-01

    It is well known that when an electron beam is incident obliquely on the surface of a phantom, the depth dose curve measured normal to the surface is shifted toward the surface. Based on geometrical arguments alone, the depth of the nth isodose line for an electron beam incident at an angle θ should be equal to the product of cos θ and the depth of the nth isodose line at normal incidence. This method, however, ignores the effects of scatter and can lead to significant errors in isodose placement for beams at large angles of incidence. A semi-empirical functional relationship and a table of isodose shift factors have been developed with which one may easily calculate the depth of any isodose line for beams at incident angles of 0 degree to 60 degree. The isodose shift factors are tabulated in terms of beam energy (6--22 MeV) and isodose line (10%--90%) and are shown to be relatively independent of beam size and incident angle for angles <60 degree. Extensive measurements have been made on a Varian Clinac 2500 linear accelerator with a parallel-plate chamber and polystyrene phantom. The dependence of the chamber response on beam angulation has been checked, and the scaling factor of the polystyrene phantom has been determined to be equal to 1.00

  17. Beam coupling in hybrid photorefractive inorganic-cholesteric liquid crystal cells: Impact of optical rotation

    International Nuclear Information System (INIS)

    Reshetnyak, V. Yu.; Pinkevych, I. P.; Sluckin, T. J.; Cook, G.; Evans, D. R.

    2014-01-01

    We develop a theoretical model to describe two-beam energy exchange in a hybrid photorefractive inorganic-cholesteric cell. A cholesteric layer is placed between two inorganic substrates. One of the substrates is photorefractive (Ce:SBN). Weak and strong light beams are incident on the hybrid cell. The interfering light beams induce a periodic space-charge field in the photorefractive window. This penetrates into the cholesteric liquid crystal (LC), inducing a diffraction grating written on the LC director. In the theory, the flexoelectric mechanism for electric field-director coupling is more important than the LC static dielectric anisotropy coupling. The LC optics is described in the Bragg regime. Each beam induces two circular polarized waves propagating in the cholesteric cell with different velocities. The model thus includes optical rotation in the cholesteric LC. The incident light beam wavelength can fall above, below, or inside the cholesteric gap. The theory calculates the energy gain of the weak beam, as a result of its interaction with the pump beam within the diffraction grating. Theoretical results for exponential gain coefficients are compared with experimental results for hybrid cells filled with cholesteric mixture BL038/CB15 at different concentrations of chiral agent CB15. Reconciliation between theory and experiment requires the inclusion of a phenomenological multiplier in the magnitude of the director grating. This multiplier is cubic in the space-charge field, and we provide a justification of the q-dependence of the multiplier. Within this paradigm, we are able to fit theory to experimental data for cholesteric mixtures with different spectral position of cholesteric gap relative to the wavelength of incident beams, subject to the use of some fitting parameters

  18. PREFACE 12th International Workshop on Slow Positron Beam Techniques

    Science.gov (United States)

    Buckman, Stephen; Sullivan, James; White, Ronald

    2011-01-01

    Preface These proceedings arose from the 12th International Workshop on Slow Positron Beam Techniques (SLOPOS12), which was held on Magnetic Island, North Queensland, Australia, between 1-6th August 2010. Meetings in the SLOPOS series are held (roughly) every three years and have now been held on (almost) all continents, indicating the truly international nature of the field. SLOPOS12 marked the second time that the Workshop had been held in the southern hemisphere, and the first time in Australia. SLOPOS12 attracted 122 delegates from 16 countries. Most encouraging was the attendance of 28 student delegates, and that about half of the overall delegates were early career researchers - a good sign for the future of our field. We also enjoyed the company of more than a dozen partners and families of delegates. In a slight departure from previous SLOPOS meetings, the International Advisory Committee approved a broader scope of scientific topics for inclusion in the program for the 2010 Workshop. This broader scope was intended to capture the applications of positrons in atomic, molecular and biomedical areas and was encapsulated in the byeline for SLOPOS-12: The 12th International Workshop on Slow Positron Beam Techniques for Solids, Surfaces, Atoms and Molecules. The scientific and social program for the meeting ran over 6 days with delegates gathering on Sunday August 1st and departing on August 6th. The scientific program included plenary, invited, contributed and student lectures, the latter being the subject of a student prize. In all there were 53 oral presentations during the week. There were also two poster sessions, with 63 posters exhibited, and a prize was awarded for the best poster by a student delegate. The standard of the student presentations, both oral and posters, was outstanding, so much so that the judging panel recommended an additional number of prizes be awarded. Topics that were the focus of invited presentations and contributed papers at

  19. Beaming teaching application: recording techniques for spatial xylophone sound rendering

    DEFF Research Database (Denmark)

    Markovic, Milos; Madsen, Esben; Olesen, Søren Krarup

    2012-01-01

    BEAMING is a telepresence research project aiming at providing a multimodal interaction between two or more participants located at distant locations. One of the BEAMING applications allows a distant teacher to give a xylophone playing lecture to the students. Therefore, rendering of the xylophon...... to spatial improvements mainly in terms of the Apparent Source Width (ASW). Rendered examples are subjectively evaluated in listening tests by comparing them with binaural recording....

  20. Multigroup and coupled forward-adjoint Monte Carlo calculation efficiencies for secondary neutron doses from proton beams

    International Nuclear Information System (INIS)

    Kelsey IV, Charles T.; Prinja, Anil K.

    2011-01-01

    We evaluate the Monte Carlo calculation efficiency for multigroup transport relative to continuous energy transport using the MCNPX code system to evaluate secondary neutron doses from a proton beam. We consider both fully forward simulation and application of a midway forward adjoint coupling method to the problem. Previously we developed tools for building coupled multigroup proton/neutron cross section libraries and showed consistent results for continuous energy and multigroup proton/neutron transport calculations. We observed that forward multigroup transport could be more efficient than continuous energy. Here we quantify solution efficiency differences for a secondary radiation dose problem characteristic of proton beam therapy problems. We begin by comparing figures of merit for forward multigroup and continuous energy MCNPX transport and find that multigroup is 30 times more efficient. Next we evaluate efficiency gains for coupling out-of-beam adjoint solutions with forward in-beam solutions. We use a variation of a midway forward-adjoint coupling method developed by others for neutral particle transport. Our implementation makes use of the surface source feature in MCNPX and we use spherical harmonic expansions for coupling in angle rather than solid angle binning. The adjoint out-of-beam transport for organs of concern in a phantom or patient can be coupled with numerous forward, continuous energy or multigroup, in-beam perturbations of a therapy beam line configuration. Out-of-beam dose solutions are provided without repeating out-of-beam transport. (author)

  1. Probing WWγ and WWγγ couplings with high energy photon beams

    International Nuclear Information System (INIS)

    Choi, S.Y.; Schrempp, F.

    1991-12-01

    We examine the potential of a future 500 GeV linear e + e - collider for probing anomalous WW γ and WW γγ couplings in the so-called γ(γ)model, corresponding to colliding γe and γγ beams from Compton backscattering of laser light. We consider in detail the 'minimal' set (k γ , λ γ ) of CP conserving anomalous couplings and present first results for the CP violating 'partner' couplings (anti K γ , anti l γ ) as well. The reactions under consideration are γe → Wν, γγ → W + W - and, as a reference, also e + e - → W + W - . We discuss the impact of both circular polarization of laser photons and polarized e(anti e) beams. Photon 'beams' due to classical Bremsstrahlung are also studied for comparison. We analyze in detail, how changes of the assumed machine parameters, cuts and systematic errors affect the sensitivity to the anomalous couplings. (orig.)

  2. Beam-based alignment technique for the SLC [Stanford Linear Collider] linac

    International Nuclear Information System (INIS)

    Adolphsen, C.E.; Lavine, T.L.; Atwood, W.B.

    1989-03-01

    Misalignment of quadrupole magnets and beam position monitors (BPMs) in the linac of the SLAC Linear Collider (SLC) cause the electron and positron beams to be steered off-center in the disk-loaded waveguide accelerator structures. Off-center beams produce wakefields which limit the SLC performance at high beam intensities by causing emittance growth. Here, we present a general method for simultaneously determining quadrupole magnet and BPM offsets using beam trajectory measurements. Results from the application of the method to the SLC linac are described. The alignment precision achieved is approximately 100 μm, which is significantly better than that obtained using optical surveying techniques. 2 refs., 4 figs

  3. Longitudinal coupling impedance of step discontinuities in a circular beam tube

    International Nuclear Information System (INIS)

    Hahn, H.; Zatz, S.

    1979-01-01

    The longitudinal coupling impedance presented by a single wall discontinuity to the circulating beam in a circular accelerator or storage ring is usually analyzed by considering a developed periodic structure. However, the typical parameters are often such that it becomes adequate to treat the discontinuity as a nonperiodic problem. Using modal field matching methods, solutions were derived for the cases of a single as well as a double-step discontinuity in a circular beam tube. Numerical results are presented in this paper and the typical behavior at low frequency, at reasonance, and above cut-off is discussed

  4. Development of plant mutation techniques using ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Si Yong; Park, In Sook; Song, Hi Sup; Kim, Dong Sub; Kim, Soo Yeon

    2006-06-15

    It has been reported that ion beam with high liner energy transfer (LET) show relative high biological effectiveness (RBE) and more effective for induced plant mutation than low LET radiation i.e., X-rays, gamma rays and electrons. This study was conducted to induce mutation of in vitro cultured orchid and Chrysanthemum using proton beam of the MC-50 cyclotron (50 MeV) at the Korea Institute of Radiological and Medical Science. In vitro cultured stems of chrysanthemum(cv. Migok) and protocom-like bodies(PLBs) of Dendrobium orchid (cv. Kingianum) placed in the plastic petridish (5.5cm in diameter) with agar medium were irradiated by the proton beam with various dose ranges of 10, 25, 50, 100 Gy under the condition of 5nA beam current. Those irradiated plants were transferred to subculture media and then investigated growth characteristics. Shoot growth of chrysanthemum and orchid was decreased by increase of irradiation dose. In particular, new shoot formation was hardly founded over 50Gy in chrysanthemum and 100 Gy in orchid. Some leaf mutants were observed at the 25 Gy and 50 Gy irradiated PLBs of the orchid. The dry seeds of hot pepper, rapeseed, rice and perilla also were irradiated with proton beam of MC-50 cyclotron and then measured germination rate and early growth of M1 plants compared with gamma ray irradiation.

  5. Development of plant mutation techniques using ion beam

    International Nuclear Information System (INIS)

    Kang, Si Yong; Park, In Sook; Song, Hi Sup; Kim, Dong Sub; Kim, Soo Yeon

    2006-06-01

    It has been reported that ion beam with high liner energy transfer (LET) show relative high biological effectiveness (RBE) and more effective for induced plant mutation than low LET radiation i.e., X-rays, gamma rays and electrons. This study was conducted to induce mutation of in vitro cultured orchid and Chrysanthemum using proton beam of the MC-50 cyclotron (50 MeV) at the Korea Institute of Radiological and Medical Science. In vitro cultured stems of chrysanthemum(cv. Migok) and protocom-like bodies(PLBs) of Dendrobium orchid (cv. Kingianum) placed in the plastic petridish (5.5cm in diameter) with agar medium were irradiated by the proton beam with various dose ranges of 10, 25, 50, 100 Gy under the condition of 5nA beam current. Those irradiated plants were transferred to subculture media and then investigated growth characteristics. Shoot growth of chrysanthemum and orchid was decreased by increase of irradiation dose. In particular, new shoot formation was hardly founded over 50Gy in chrysanthemum and 100 Gy in orchid. Some leaf mutants were observed at the 25 Gy and 50 Gy irradiated PLBs of the orchid. The dry seeds of hot pepper, rapeseed, rice and perilla also were irradiated with proton beam of MC-50 cyclotron and then measured germination rate and early growth of M1 plants compared with gamma ray irradiation

  6. Direct coupling of a dense (supercritical) gas chromatograph to a mass spectrometer using a supersonic molecular beam interface

    International Nuclear Information System (INIS)

    Randall, L.G.; Wahrhaftig, A.L.

    1981-01-01

    A detecting mass spectrometer has been successfully coupled to a dense gas (supercritical fluid) chromatograph to produce an instrument (DGC/MS) that may be an alternative to high performance liquid chromatograph/mass spectrometer instruments (HPLC/MS) and gas chromatograph/mass spectrometer instruments (GC/MS) for analysis of involatile and/or thermally labile compounds. The mobile phase in DGC is a gas held at temperatures above the critical temperature and at pressures sufficient to obtain nearly liquid-like densities. DGC combines advantages of GC and HPLC: rapid separations, moderate operating temperatures, and analysis of involatile compounds. An advantage unique to DGC is the solvent power dependence upon pressure. While several groups have studied DGC, its development has been limited by the lack of a sensitive and selective detector. Hence, work has been directed towards the design and construction of a DGC/MS resulting in a trial instrument capable of chromatographic pressures of at least 300 atm and temperatures from 10 0 to 60 0 C. The DGC/MS coupling has been accomplished by the use of a supersonic molecular beam interface. This application of molecular beam formation appears to be unique in its requirements of a large pressure ratio (approx.10 8 ), low flow rates, and low final pressures. The authors outline characteristics of supersonic jets and molecular beams pertinent to the design of such an instrument. The interface which uses pumping speeds of 2400 and 1200 l/s in the beam forming chambers is described in detail, while the other components: the detecting mass spectrometer, the dense gas supply, and the DGC: are briefly described. Preliminary work with this instrument has established the feasibility of DGC/MS as an analytical technique and further development is recommended

  7. Longitudinal coupling impedance of a hole in the accelerator beam pipe

    International Nuclear Information System (INIS)

    Chae, Yong-Chul.

    1993-12-01

    In the design of modern accelerators, an accurate estimate of coupling impedance is very important. The sources which give rise to coupling impedance are the geometric discontinuities in the accelerator beam pipe. In various discontinuities such as RF cavities, bellows, and collimators, the coupling impedance of the holes has not been well understood. Although coupling impedance can be obtained in general from the Fourier transform of the corresponding wake potential which may be obtained numerically, this is time consuming and requires a large amount of computer storage when applied to a small dimension of a discontinuity in a typical beam pipe, often imposing a fundamental limitation of the numerical approach. More fundamentally, however, numerical calculation does not have the predictive power because of limited understanding of how the coupling impedance of a hole should behave over a wide frequency range. This question was studied by developing a theoretical analysis based on a variational method. An analytical formula for the coupling impedance of a hole is developed in this work using a variational method. The result gives good qualitative agreements with the coupling impedances evaluated numerically from the Fourier transform of the wake potential which is obtained from the computer code MAFIA-T3. The author shows that the coupling impedance of a hole behaves quite similar to the impedance of an RLC-resonator circuit. Important parameters used to describe such a resonator circuit are the resonant frequency and bandwidth. The author provides a theoretical insight on how to parameterize properly the numerical impedance of a hole when data exhibit complicated dependence on frequency. This is possible because one can show that the parameters are a function of the dimensionless quantity kd alone, with k the free-space wave number and d the radius of hole

  8. Recirculating beam-breakup thresholds for polarized higher-order modes with optical coupling

    Directory of Open Access Journals (Sweden)

    Georg H. Hoffstaetter

    2007-04-01

    Full Text Available Here we will derive the general theory of the beam-breakup (BBU instability in recirculating linear accelerators with coupled beam optics and with polarized higher-order dipole modes. The bunches do not have to be at the same radio-frequency phase during each recirculation turn. This is important for the description of energy recovery linacs (ERLs where beam currents become very large and coupled optics are used on purpose to increase the threshold current. This theory can be used for the analysis of phase errors of recirculated bunches, and of errors in the optical coupling arrangement. It is shown how the threshold current for a given linac can be computed and a remarkable agreement with tracking data is demonstrated. General formulas are then analyzed for several analytically solvable problems: (a Why can different higher order modes (HOM in one cavity couple and why can they then not be considered individually, even when their frequencies are separated by much more than the resonance widths of the HOMs? For the Cornell ERL as an example, it is noted that optimum advantage is taken of coupled optics when the cavities are designed with an x-y HOM frequency splitting of above 50 MHz. The simulated threshold current is then far above the design current of this accelerator. To justify that the simulation can represent an actual accelerator, we simulate cavities with 1 to 8 modes and show that using a limited number of modes is reasonable. (b How does the x-y coupling in the particle optics determine when modes can be considered separately? (c How much of an increase in threshold current can be obtained by coupled optics and why does the threshold current for polarized modes diminish roughly with the square root of the HOMs’ quality factors. Because of this square root scaling, polarized modes with coupled optics increase the threshold current more effectively for cavities that have rather large HOM quality factors, e.g. those without very

  9. Numerical Verification of the Power Transfer and Wakefield Coupling in the CLIC Two-Beam Accelerator

    CERN Document Server

    Candel, Arno; NG, C; Rawat, V; Schussman, G; Ko, K; Syratchev, I; Grudiev, A; Wuensch, W

    2011-01-01

    The Compact Linear Collider (CLIC) provides a path to a multi-TeV accelerator to explore the energy frontier of High Energy Physics. Its two-beam accelerator (TBA) concept envisions complex 3D structures, which must be modeled to high accuracy so that simulation results can be directly used to prepare CAD drawings for machining. The required simulations include not only the fundamental mode properties of the accelerating structures but also the Power Extraction and Transfer Structure (PETS), as well as the coupling between the two systems. Time-domain simulations will be performed to understand pulse formation, wakefield damping, fundamental power transfer and wakefield coupling in these structures. Applying SLAC’s parallel finite element code suite, these large-scale problems will be solved on some of the largest supercomputers available. The results will help to identify potential issues and provide new insights on the design, leading to further improvements on the novel two-beam accelerator scheme.

  10. Techniques to produce and accelerate radioactive ion beams

    CERN Document Server

    Penescu, Liviu Constantin; Lettry, Jacques; Cata-Danil, Gheorghe

    The production and acceleration of the Radioactive Ion Beams (RIB) continues the long line of nuclear investigations started in the XIXth century by Pierre and Marie Curie, Henri Becquerel and Ernest Rutherford. The contemporary applications of the RIBs span a wide range of physics fields: nuclear and atomic physics, solid-state physics, life sciences and material science. ISOLDE is a world-leading Isotope mass-Separation On-Line (ISOL) facility hosted at CERN in Geneva for more than 40 years, offering the largest variety of radioactive ion beams with, until now, more than 1000 isotopes of more than 72 elements (with Z ranging from 2 to 88), with half-lives down to milliseconds and intensities up to 1011 ions/s. The post acceleration of the full variety of beams allows reaching final energies between 0.8 and 3.0 MeV/u. This thesis describes the development of a new series of FEBIAD (“Forced Electron Beam Induced Arc Discharge”) ion sources at CERN-ISOLDE. The VADIS (“Versatile Arc Discharge Ion Source�...

  11. Damage identification in beams by a response surface based technique

    Directory of Open Access Journals (Sweden)

    Teidj S.

    2014-01-01

    Full Text Available In this work, identification of damage in uniform homogeneous metallic beams was considered through the propagation of non dispersive elastic torsional waves. The proposed damage detection procedure consisted of the following sequence. Giving a localized torque excitation, having the form of a short half-sine pulse, the first step was calculating the transient solution of the resulting torsional wave. This torque could be generated in practice by means of asymmetric laser irradiation of the beam surface. Then, a localized defect assumed to be characterized by an abrupt reduction of beam section area with a given height and extent was placed at a known location of the beam. Next, the response in terms of transverse section rotation rate was obtained for a point situated afterwards the defect, where the sensor was positioned. This last could utilize in practice the concept of laser vibrometry. A parametric study has been conducted after that by using a full factorial design of experiments table and numerical simulations based on a finite difference characteristic scheme. This has enabled the derivation of a response surface model that was shown to represent adequately the response of the system in terms of the following factors: defect extent and severity. The final step was performing the inverse problem solution in order to identify the defect characteristics by using measurement.

  12. Convergent beam electron diffraction – A novel technique for ...

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    The subsequent development of STEM units made it possible to obtain finer probes with ... inability to identify the position of atoms in a unit cell, was completely eliminated by ... CBED patterns in the first attempt to measure structural factors using ... Gjonnes & Hoier (1971) analysed this effect based on the three-beam theory.

  13. Ultrafast directional beam switching in coupled vertical-cavity surface-emitting lasers

    International Nuclear Information System (INIS)

    Ning, C. Z.; Goorjian, P.

    2001-01-01

    We propose a strategy to performing ultrafast directional beam switching using two coupled vertical-cavity surface-emitting lasers (VCSELs). The proposed strategy is demonstrated for two VCSELs of 5.6 μm in diameter placed about 1 μm apart from the edges, showing a switching speed of 42 GHz with a maximum far-field angle span of about 10 degree. [copyright] 2001 American Institute of Physics

  14. New Meta and Nanomaterials for Photorefractive Enhancement and Photorefractive Two-Beam Coupling

    Science.gov (United States)

    2010-03-12

    Centro de Investigacion de Quimica Aplicada Blvd. Enrique reyna, No. 140 Saltillo, Coahuila, Mexico 25253 AFOSR FA9550-09-1-0023 12 March 2010...ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER CENTRO DE INVESTIGACION EN QUIMICA APLICADA BLVD ENRIQUE REYNA NO 140 SALTILLO 25253...Photorefractive Two-Beam Coupling Ronald F. Ziolo Centro de Investigacion de Quimica Aplicada Saltillo, Coahuila, Mexico 25253 Grant

  15. Arrays of Size-Selected Metal Nanoparticles Formed by Cluster Ion Beam Technique

    DEFF Research Database (Denmark)

    Ceynowa, F. A.; Chirumamilla, Manohar; Zenin, Volodymyr

    2018-01-01

    Deposition of size-selected copper and silver nanoparticles (NPs) on polymers using cluster beam technique is studied. It is shown that ratio of particle embedment in the film can be controlled by simple thermal annealing. Combining electron beam lithography, cluster beam deposition, and heat...... with required configurations which can be applied for wave-guiding, resonators, in sensor technologies, and surface enhanced Raman scattering....

  16. High-flux cold rubidium atomic beam for strongly-coupled cavity QED

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Basudev [Indian Institute of Science Education and Research, Kolkata (India); University of Maryland, MD (United States); Scholten, Michael [University of Maryland, MD (United States)

    2012-08-15

    This paper presents a setup capable of producing a high-flux continuous beam of cold rubidium atoms for cavity quantum electrodynamics experiments in the region of strong coupling. A 2D{sup +} magneto-optical trap (MOT), loaded with rubidium getters in a dry-film-coated vapor cell, fed a secondary moving-molasses MOT (MM-MOT) at a rate greater than 2 x 10{sup 10} atoms/s. The MM-MOT provided a continuous beam with a tunable velocity. This beam was then directed through the waist of a cavity with a length of 280 μm, resulting in a vacuum Rabi splitting of more than ±10 MHz. The presence of a sufficient number of atoms in the cavity mode also enabled splitting in the polarization perpendicular to the input. The cavity was in the strong coupling region, with an atom-photon dipole coupling coefficient g of 7 MHz, a cavity mode decay rate κ of 3 MHz, and a spontaneous emission decay rate γ of 6 MHz.

  17. Equilibrium beam distribution in an electron storage ring near linear synchrobetatron coupling resonances

    Directory of Open Access Journals (Sweden)

    Boaz Nash

    2006-03-01

    Full Text Available Linear dynamics in a storage ring can be described by the one-turn map matrix. In the case of a resonance where two of the eigenvalues of this matrix are degenerate, a coupling perturbation causes a mixing of the uncoupled eigenvectors. A perturbation formalism is developed to find eigenvalues and eigenvectors of the one-turn map near such a linear resonance. Damping and diffusion due to synchrotron radiation can be obtained by integrating their effects over one turn, and the coupled eigenvectors can be used to find the coupled damping and diffusion coefficients. Expressions for the coupled equilibrium emittances and beam distribution moments are then derived. In addition to the conventional instabilities at the sum, integer, and half-integer resonances, it is found that the coupling can cause an instability through antidamping near a sum resonance even when the symplectic dynamics are stable. As one application of this formalism, the case of linear synchrobetatron coupling is analyzed where the coupling is caused by dispersion in the rf cavity, or by a crab cavity. Explicit closed-form expressions for the sum/difference resonances are given along with the integer/half-integer resonances. The integer and half-integer resonances caused by coupling require particular care. We find an example of this with the case of a crab cavity for the integer resonance of the synchrotron tune. Whether or not there is an instability is determined by the value of the horizontal betatron tune, a unique feature of these coupling-caused integer or half-integer resonances. Finally, the coupled damping and diffusion coefficients along with the equilibrium invariants and projected emittances are plotted as a function of the betatron and synchrotron tunes for an example storage ring based on PEP-II.

  18. Beam shaping optics to enhance performance of interferometry techniques in grating manufacture

    Science.gov (United States)

    Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei

    2018-02-01

    Improving of industrial holographic and interferometry techniques is of great importance in interference lithography, computer-generated holography, holographic data storage, interferometry recording of Bragg gratings as well as gratings of various types in semiconductor industry. Performance of mentioned techniques is essentially enhanced by providing a light beam with flat phase front and flat-top irradiance distribution. Therefore, transformation of Gaussian distribution of a TEM00 laser to flat-top (top hat, uniform) distribution is an important optical task. There are different refractive and diffractive beam shaping approaches used in laser industrial and scientific applications, but only few of them are capable to fulfil the optimum conditions for beam quality demanding holography and interferometry. As a solution it is suggested to apply refractive field mapping beam shaping optics πShaper, which operational principle presumes almost lossless transformation of Gaussian to flat-top beam with flatness of output wavefront, conserving of beam consistency, providing collimated low divergent output beam, high transmittance, extended depth of field, negligible wave aberration, and achromatic design provides capability to work with several lasers with different wavelengths simultaneously. High optical quality of resulting flat-top beam allows applying additional optical components to build various imaging optical systems for variation of beam size and shape to fulfil requirements of a particular application. This paper will describe design basics of refractive beam shapers and optical layouts of their applying in holography and laser interference lithography. Examples of real implementations and experimental results will be presented as well.

  19. Beam manipulation techniques, nonlinear beam dynamics, and space charge effect in high energy high power accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. Y. [Indiana Univ., Bloomington, IN (United States)

    2014-04-07

    We had carried out a design of an ultimate storage ring with beam emittance less than 10 picometer for the feasibility of coherent light source at X-ray wavelength. The accelerator has an inherent small dynamic aperture. We study method to improve the dynamic aperture and collective instability for an ultimate storage ring. Beam measurement and accelerator modeling are an integral part of accelerator physics. We develop the independent component analysis (ICA) and the orbit response matrix method for improving accelerator reliability and performance. In collaboration with scientists in National Laboratories, we also carry out experimental and theoretical studies on beam dynamics. Our proposed research topics are relevant to nuclear and particle physics using high brightness particle and photon beams.

  20. Applied dosimetry to ionization techniques by electron beams

    International Nuclear Information System (INIS)

    Kuntz, F.

    1991-12-01

    After a general introduction about electron beam dosimetry, the second part is about the determination of treatment parameter for an electron ionization: are treated the problems of electron path determination, treatment depth of a product and finally, the radiation dose heterogeneities in all the volume of a treated product. The third part describes a process that greatly reduces radiation dose heterogeneity and then industrial interest is analyzed. The fourth part describes 2 applications of diffusion screen utilization. 66 figs

  1. Direct Coupling of Electron Beam Irradiation and Polymer Extrusion for a Continuous Polymer Modification in Molten State

    International Nuclear Information System (INIS)

    Stephan, M.

    2006-01-01

    The new approach of an e-beam initiating of chemical reactions in polymers in molten state results in some innovative results. High temperature, intensive macromolecular mobility and the absence of any crystallinity are some reasons for achieving unexpected structures, processing behaviour and properties changes in such treated thermoplastics and rubbers. Examples are a much more effective crosslinking of polyethylene and special rubbers, long chain branching of polypropylene or a partial crosslinking of polysulfone. Additionally, most of these modification effects are also achievable by a direct coupling of electron beam irradiation and conventional polymer extrusion processing for a continuous polymer modification in molten state. For realizing this unique processing technique a special MOBILE RADIATION FACILITY (MOBRAD1/T) was designed, constructed and manufactured in the IPF Dresden at which a lab-scale single screw extruder was adapted direct to an electron beam accelerator to realize a prompt irradiation of extruded polymer melt profiles before there solidification. Surprisingly, as a result of these short-time-melt reactions some effective and new polymer modification effects were found and will be presented

  2. Development of Focused Ion Beam technique for high speed steel 3D-SEM artefact fabrication

    DEFF Research Database (Denmark)

    Carli, Lorenzo; MacDonald, A. Nicole; De Chiffre, Leonardo

    2009-01-01

    The work describes preliminary manufacture by grinding, followed by machining on a Focused Ion Beam (FIB), of a high speed steel step artefact for 3D-SEM calibration. The FIB is coupled with a SEM in the so called dual beam instrument. The milling capabilities of FIB were checked from a qualitative...... point of view, using the dual beam SEM imaging, and quantitatively using a reference stylus instrument, to establish traceability. A triangular section having a depth of about 10 μm was machined, where the 50 μm curvature radius due to grinding was reduced to about 2 μm by FIB milling...

  3. Couplings

    Science.gov (United States)

    Stošić, Dušan; Auroux, Aline

    Basic principles of calorimetry coupled with other techniques are introduced. These methods are used in heterogeneous catalysis for characterization of acidic, basic and red-ox properties of solid catalysts. Estimation of these features is achieved by monitoring the interaction of various probe molecules with the surface of such materials. Overview of gas phase, as well as liquid phase techniques is given. Special attention is devoted to coupled calorimetry-volumetry method. Furthermore, the influence of different experimental parameters on the results of these techniques is discussed, since it is known that they can significantly influence the evaluation of catalytic properties of investigated materials.

  4. Fiber coupled diode laser beam parameter product calculation and rules for optimized design

    Science.gov (United States)

    Wang, Zuolan; Segref, Armin; Koenning, Tobias; Pandey, Rajiv

    2011-03-01

    The Beam Parameter Product (BPP) of a passive, lossless system is a constant and cannot be improved upon but the beams may be reshaped for enhanced coupling performance. The function of the optical designer of fiber coupled diode lasers is to preserve the brightness of the diode sources while maximizing the coupling efficiency. In coupling diode laser power into fiber output, the symmetrical geometry of the fiber core makes it highly desirable to have symmetrical BPPs at the fiber input surface, but this is not always practical. It is therefore desirable to be able to know the 'diagonal' (fiber) BPP, using the BPPs of the fast and slow axes, before detailed design and simulation processes. A commonly used expression for this purpose, i.e. the square root of the sum of the squares of the BPPs in the fast and slow axes, has been found to consistently under-predict the fiber BPP (i.e. better beam quality is predicted than is actually achievable in practice). In this paper, using a simplified model, we provide the proof of the proper calculation of the diagonal (i.e. the fiber) BPP using BPPs of the fast and slow axes as input. Using the same simplified model, we also offer the proof that the fiber BPP can be shown to have a minimum (optimal) value for given diode BPPs and this optimized condition can be obtained before any detailed design and simulation are carried out. Measured and simulated data confirms satisfactory correlation between the BPPs of the diode and the predicted fiber BPP.

  5. An evaluation testing technique of single event effect using Beam Blanking SEM

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, J; Hada, T; Pesce, A; Akutsu, T; Matsuda, S [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Igarashi, T; Baba, S

    1997-03-01

    Beam Blanking SEM (Scanning Electron Microscope) testing technique has been applied to CMOS SRAM devices to evaluate the occurence of soft errors on memory cells. Cross-section versus beam current and LET curves derived from BBSEM and heavy ion testing technique, respectively, have been compared. A linear relation between BBSEM current and heavy ion LET has been found. The purpose of this study was to demonstrate that the application of focused pulsed electron beam could be a reliable, convenient and inexpensive tool to investigate the effects of heavy ions and high energy particles on memory devices for space application. (author)

  6. A new crossed molecular beam apparatus using time-sliced ion velocity imaging technique

    International Nuclear Information System (INIS)

    Wu Guorong; Zhang Weiqing; Pan Huilin; Shuai Quan; Jiang Bo; Dai Dongxu; Yang Xueming

    2008-01-01

    A new crossed molecular beam apparatus has been constructed for investigating polyatomic chemical reactions using the time-sliced ion velocity map imaging technique. A unique design is adopted for one of the two beam sources and allows us to set up the molecular beam source either horizontally or vertically. This can be conveniently used to produce versatile atomic or radical beams from photodissociation and as well as electric discharge. Intensive H-atom beam source with high speed ratio was produced by photodissociation of the HI molecule and was reacted with the CD 4 molecule. Vibrational-state resolved HD product distribution was measured by detecting the CD 3 product. Preliminary results were also reported on the F+SiH 4 reaction using the discharged F atom beam. These results demonstrate that this new instrument is a powerful tool for investigating chemical dynamics of polyatomic reactions.

  7. Soft X-ray beam induced current technique

    Energy Technology Data Exchange (ETDEWEB)

    Watts, B; Ade, H [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Queen, D; Hellman, F [Department of Physics, University of California, Berkeley, CA 94720 (United States); Kilcoyne, A L D; Tyliszczak, T, E-mail: benjamin.watts@gmail.co [Advanced Light Source, Lawrence Berkeley Nat. Lab., Berkeley, CA 94720 (United States)

    2009-09-01

    Direct mapping of the charge transport efficiency of polymer solar cell devices using a soft X-ray beam induced current (SoXBIC) method is described. By fabricating a polymer solar cell on an x-ray transparent substrate, we demonstrate the ability to map polymer composition and nanoscale structure within an operating solar cell device and to simultaneously measure the local charge transport efficiency via the short-circuit current. A simple model is calculated and compared to experimental SoXBIC data of a PFB:F8BT bulk-heterojunction device in order to gain greater insight into the device operation and physics.

  8. The beam based alignment technique for the measurements of beam position monitors offsets and beam offsets from quadrupoles in the Pohang Light Source

    International Nuclear Information System (INIS)

    Kim, K.H.; Huang, J.Y.; Ko, I.S.

    1999-01-01

    The beam based alignment (BBA) technique is applied to the 2-GeV storage ring of the Pohang Light Source to measure the offsets of beam position monitors. This measurement is particularly necessary for beam position monitors (BPMs) plugged into a long (∼10 m) aluminum chamber, since the mechanical deformation of the vacuum chamber is experienced after repeated heating for the outgassing process, and the BPM positions are changed accordingly. A part of the excitation current of each quadrupole magnet is shunted through an electronic shunt circuit. Then, the closed orbit receives a perturbation due to the current reduction. Using two quadrupole magnets, we can measure the offset of each BPM. Also, the BBA technique is applied to measure the beam offsets from the center of quadrupole magnets, and gives information to the survey team about which quadrupole magnets should be aligned mostly. In this process, we introduce the merit function to reduce various errors such as BPM characteristic changes and the lattice imperfection. By minimizing the merit function, we can get the beam offset as the maximized expectation value. This paper presents the BBA technique used and experimental results taken from the 2-GeV Pohang Light Source (PLS) storage ring. When the BPM offset is measured, it is observed that a 3% of the shunt current is suitable. (author)

  9. Experimental investigation of coupling between widely spaced modes of a beam using higher-order spectra

    International Nuclear Information System (INIS)

    Khan, K.A.

    2001-01-01

    Experimental studies related to a thin isotropic steel beam are presented. The beam was harmonically excited along its axis creating a situation of parametric excitation. A possible two-to-one internal resonance was considered between the third and fourth modes of the beam with an external resonance of its fourth mode. The coupling phenomenon responsible for transfer of energy from high frequency modes to a widely spaced low frequency mode was studied by using conventional tools and higher-order spectra (third-order spectrum (bispectrum) and fourth-order spectrum (trispectrum)). Pointwise dimensions of the attractors were examined to ascertain their chaotic character. The potential of higher-order spectra in detecting the quadratic and cubic phase couplings among the participating modes during bifurcations, periodically modulated motions, and chaotically modulated motions was also examined. The experimental results are provided in the form of power spectra, fractal dimensions, bispectra, bicoherence spectra, and trispectrum. Experimental observations of transitions from periodic to periodically modulated to chaotically-modulated motions are also presented. (author)

  10. Techniques for evaluation of E-beam evaporative processes

    International Nuclear Information System (INIS)

    Meier, T.C.; Nelson, C.M.

    1996-01-01

    High dynamic range video imaging of the molten pool surface has provided insight regarding process responses at the melt pool liquid-vapor interface. A water-cooled video camera provides continuous high resolution imaging of the pool surface from a low angle position within 20 cm of the liquid-vapor interface. From the vantage point, the e-beam footprint is clearly defined and melt pool free surface shape can be observed. Effects of changes in a beam footprint, power distribution, and sweep frequency on pool surface shape and stability of vaporization are immediately shown. Other events observed and recorded include: formation of the pool and dissipation of ''rafts'' on the pool surface during startup, behavior of feed material as it enters the pool, effects of feed configuration changes on mixing of feed entering the pool volume and behaviors of co-evaporated materials of different vapor pressures at the feed/pool boundary. When used in conjunction with laser vapor monitoring, correlation between pool surface phenomena and vaporizer performance has been identified. This video capability was used in verifying the titanium evaporation model results presented at this conference by confirming the calculated melt pool surface deformations caused by vapor pressure of the departing evaporant at the liquid-vapor interface

  11. Techniques for evaluation of E-beam evaporative processes

    Energy Technology Data Exchange (ETDEWEB)

    Meier, T.C.; Nelson, C.M.

    1996-10-01

    High dynamic range video imaging of the molten pool surface has provided insight regarding process responses at the melt pool liquid-vapor interface. A water-cooled video camera provides continuous high resolution imaging of the pool surface from a low angle position within 20 cm of the liquid-vapor interface. From the vantage point, the e-beam footprint is clearly defined and melt pool free surface shape can be observed. Effects of changes in a beam footprint, power distribution, and sweep frequency on pool surface shape and stability of vaporization are immediately shown. Other events observed and recorded include: formation of the pool and dissipation of ``rafts`` on the pool surface during startup, behavior of feed material as it enters the pool, effects of feed configuration changes on mixing of feed entering the pool volume and behaviors of co-evaporated materials of different vapor pressures at the feed/pool boundary. When used in conjunction with laser vapor monitoring, correlation between pool surface phenomena and vaporizer performance has been identified. This video capability was used in verifying the titanium evaporation model results presented at this conference by confirming the calculated melt pool surface deformations caused by vapor pressure of the departing evaporant at the liquid-vapor interface.

  12. An efficient coupled polynomial interpolation scheme to eliminate material-locking in the Euler-Bernoulli piezoelectric beam finite element

    Directory of Open Access Journals (Sweden)

    Litesh N. Sulbhewar

    Full Text Available The convergence characteristic of the conventional two-noded Euler-Bernoulli piezoelectric beam finite element depends on the configuration of the beam cross-section. The element shows slower convergence for the asymmetric material distribution in the beam cross-section due to 'material-locking' caused by extension-bending coupling. Hence, the use of conventional Euler-Bernoulli beam finite element to analyze piezoelectric beams which are generally made of the host layer with asymmetrically surface bonded piezoelectric layers/patches, leads to increased computational effort to yield converged results. Here, an efficient coupled polynomial interpolation scheme is proposed to improve the convergence of the Euler-Bernoulli piezoelectric beam finite elements, by eliminating ill-effects of material-locking. The equilibrium equations, derived using a variational formulation, are used to establish relationships between field variables. These relations are used to find a coupled quadratic polynomial for axial displacement, having contributions from an assumed cubic polynomial for transverse displacement and assumed linear polynomials for layerwise electric potentials. A set of coupled shape functions derived using these polynomials efficiently handles extension-bending and electromechanical couplings at the field interpolation level itself in a variationally consistent manner, without increasing the number of nodal degrees of freedom. The comparison of results obtained from numerical simulation of test problems shows that the convergence characteristic of the proposed element is insensitive to the material configuration of the beam cross-section.

  13. Beam transfer between the coupled cavity linac and the low energy booster synchrotron for the SSC [Superconducting Super Collider

    International Nuclear Information System (INIS)

    Bhandari, R.K.; Penner, S.

    1990-09-01

    Ion optical design of the transfer line, which will be used to inject H - beam at 600 MeV from the Coupled Cavity Linac (CCL) into the Low Energy Booster (LEB) synchrotron, is described. Space charge effects of up to 50 mA average beam current have been taken into account

  14. Study on power coupling of annular vortex beam propagating through a two-Cassegrain-telescope optical system in turbulent atmosphere.

    Science.gov (United States)

    Wu, Huiyun; Sheng, Shen; Huang, Zhisong; Zhao, Siqing; Wang, Hua; Sun, Zhenhai; Xu, Xiegu

    2013-02-25

    As a new attractive application of the vortex beams, power coupling of annular vortex beam propagating through a two- Cassegrain-telescope optical system in turbulent atmosphere has been investigated. A typical model of annular vortex beam propagating through a two-Cassegrain-telescope optical system is established, the general analytical expression of vortex beams with limited apertures and the analytical formulas for the average intensity distribution at the receiver plane are derived. Under the H-V 5/7 turbulence model, the average intensity distribution at the receiver plane and power coupling efficiency of the optical system are numerically calculated, and the influences of the optical topological charge, the laser wavelength, the propagation path and the receiver apertures on the power coupling efficiency are analyzed. These studies reveal that the average intensity distribution at the receiver plane presents a central dark hollow profile, which is suitable for power coupling by the Cassegrain telescope receiver. In the optical system with optimized parameters, power coupling efficiency can keep in high values with the increase of the propagation distance. Under the atmospheric turbulent conditions, great advantages of vortex beam in power coupling of the two-Cassegrain-telescope optical system are shown in comparison with beam without vortex.

  15. Radiation therapy for retinoblastoma: comparison of results with lens-sparing versus lateral beam techniques

    International Nuclear Information System (INIS)

    McCormick, B.; Ellsworth, R.; Abramson, D.; Haik, B.; Tome, M.; Grabowski, E.; LoSasso, T.

    1988-01-01

    From 1979 through 1986, 170 children were seen at our institution diagnosed with retinoblastoma. Sixty-six of the children with involvement of 121 eyes, were referred for definitive external beam radiation to one or both eyes. During the study period, two distinct radiation techniques were used. From 1980 through mid-1984, a lens-sparing technique included an anterior electron beam with a contact lens mounted lead shield, combined with a lateral field, was used. Since mid-1984, a modified lateral beam technique has been used, mixing lateral electrons and superior and inferior lateral oblique split beam wedged photons. Doses prescribed were similar for both techniques, ranging from 3,850 to 5,000 cGy in 4 to 5 weeks. The lens-sparing and the modified lateral techniques are compared for local control. For eyes with Group I through III disease, the lens-sparing technique resulted in local control in 33% of the eyes treated, where the modified lateral technique controlled 83% of the eyes treated (p = .006). Mean time to relapse was identical in both groups, that is 24 and 26 months respectively. Most relapses were successfully treated with further local therapy, including laser or cryosurgery, or 60Co plaques. Five eyes required enucleation following initial treatment with the lens-sparing technique, but none thus far with the lateral beam technique. For eyes with Group IV and V disease, no significant differences were found between the two techniques in terms of local control or eventual need for enucleation. With a mean follow-up time of 33 months for the entire group, the 4-year survival is 93%. Two of the 4 deaths are due to second primary tumor, and all 4 have occurred in the lens-sparing group. Because follow-up time is more limited in the lateral beam group, this is not statistically significant and direct survival comparisons are premature

  16. ACE3P Computations of Wakefield Coupling in the CLIC Two-Beam Accelerator

    International Nuclear Information System (INIS)

    Candel, Arno

    2010-01-01

    The Compact Linear Collider (CLIC) provides a path to a multi-TeV accelerator to explore the energy frontier of High Energy Physics. Its novel two-beam accelerator concept envisions rf power transfer to the accelerating structures from a separate high-current decelerator beam line consisting of power extraction and transfer structures (PETS). It is critical to numerically verify the fundamental and higher-order mode properties in and between the two beam lines with high accuracy and confidence. To solve these large-scale problems, SLAC's parallel finite element electromagnetic code suite ACE3P is employed. Using curvilinear conformal meshes and higher-order finite element vector basis functions, unprecedented accuracy and computational efficiency are achieved, enabling high-fidelity modeling of complex detuned structures such as the CLIC TD24 accelerating structure. In this paper, time-domain simulations of wakefield coupling effects in the combined system of PETS and the TD24 structures are presented. The results will help to identify potential issues and provide new insights on the design, leading to further improvements on the novel CLIC two-beam accelerator scheme.

  17. Stability of higher-order longitudinal modes in a bunched beam without mode coupling

    International Nuclear Information System (INIS)

    Satoh, K.

    1981-05-01

    The theory of longitudinal instabilities of bunched beams was proposed by F. Sacherer. Starting from the Vlasov equation, he derived the integral equation for the perturbed distribution function. While the general method to solve the integral equation was given by Sacherer, a number of other papers discussing longitudinal bunched beam instability have also been published. Here we want to propose another formalism with which we can treat the integral equation without mode coupling for the case of a Gaussian bunch. We then generalize the formalism for the other bunch distributions, and derive a practical method to analyze the instability for the case of a parabolic bunch. While the solution of the Sacherer equation that we find is not new, we present another approach to solve it. Since the integral equation for the transverse instability is similar to that for the longitudinal instability, this formalism is also useful for the transverse case. 12 figs., 4 figs

  18. Dosimetric evaluations and comparisons between different techniques (Fan beam, Cone beam, OPT) in the dental industry and not

    International Nuclear Information System (INIS)

    Rampado, O.

    2014-01-01

    In recent years there has been an impressive evolution and spread of cone beam tomographic equipment, in particular in the dental and maxillofacial surgery. These devices exhibit unique characteristics both from the point of view of the geometric parameters of exposure than the quality of the beams radiating employed. In parallel to this technological development it was dealt with the quantification of the dose to the patient, with a discussion between experts to define what are the variables most appropriate to use and the appropriate ways of measuring. And it is of interest also the discussion on the comparison of the risks associated with the use of this method as an alternative to traditional techniques or other tomographic techniques, both on the criteria of optimization in the realization of the tests.

  19. Technique for measuring charged particle distribution in a pulsed beam. Sposob izmereniya raspredeleniya zaryazhennykh chastits v impul'snom puchke

    Energy Technology Data Exchange (ETDEWEB)

    Zakutin, V V; Shenderovich, A M

    1988-11-07

    Technique for measuring charged particle distribution in a pulsed beam by producing beam imprint on a target is described. In order to measure beam particle distribution in longitudinal direction, all beam particles are deflected simultaneously to the target, located in parallel with initial direction of beam motion, by transverse pulse magnetic field, homogeneous in the field of trajectories of beam particle motion in the field. The invention enables to conduct measurements of longitudinal distribution of particle density in beams of 10{sup -9}-10{sup -11}s duration, this corresponds to longitudinal beam dimensions from 30 cm down to 3 mm. 1 fig.

  20. Generalized Kapchinskij-Vladimirskij Distribution and Envelope Equation for High-intensity Beams in a Coupled Transverse Focusing Lattice

    International Nuclear Information System (INIS)

    Qin, Hong; Chung, Moses; Davidson, Ronald C.

    2009-01-01

    In an uncoupled lattice, the Kapchinskij-Vladimirskij (KV) distribution function first analyzed in 1959 is the only known exact solution of the nonlinear Vlasov-Maxwell equations for high- intensity beams including self-fields in a self-consistent manner. The KV solution is generalized here to high-intensity beams in a coupled transverse lattice using the recently developed generalized Courant-Snyder invariant for coupled transverse dynamics. This solution projects to a rotating, pulsating elliptical beam in transverse configuration space, determined by the generalized matrix envelope equation.

  1. Ion beam induced defects in solids studied by optical techniques

    International Nuclear Information System (INIS)

    Comins, J.D.; Amolo, G.O.; Derry, T.E.; Connell, S.H.; Erasmus, R.M.; Witcomb, M.J.

    2009-01-01

    Optical methods can provide important insights into the mechanisms and consequences of ion beam interactions with solids. This is illustrated by four distinctly different systems. X- and Y-cut LiNbO 3 crystals implanted with 8 MeV Au 3+ ions with a fluence of 1 x 10 17 ions/cm 2 result in gold nanoparticle formation during high temperature annealing. Optical extinction curves simulated by the Mie theory provide the average nanoparticle sizes. TEM studies are in reasonable agreement and confirm a near-spherical nanoparticle shape but with surface facets. Large temperature differences in the nanoparticle creation in the X- and Y-cut crystals are explained by recrystallisation of the initially amorphised regions so as to recreate the prior crystal structure and to result in anisotropic diffusion of the implanted gold. Defect formation in alkali halides using ion beam irradiation has provided new information. Radiation-hard CsI crystals bombarded with 1 MeV protons at 300 K successfully produce F-type centres and V-centres having the I 3 - structure as identified by optical absorption and Raman studies. The results are discussed in relation to the formation of interstitial iodine aggregates of various types in alkali iodides. Depth profiling of I 3 - and I 5 - aggregates created in RbI bombarded with 13.6 MeV/A argon ions at 300 K is discussed. The recrystallisation of an amorphous silicon layer created in crystalline silicon bombarded with 100 keV carbon ions with a fluence of 5 x 10 17 ions/cm 2 during subsequent high temperature annealing is studied by Raman and Brillouin light scattering. Irradiation of tin-doped indium oxide (ITO) films with 1 MeV protons with fluences from 1 x 10 15 to 250 x 10 15 ions/cm -2 induces visible darkening over a broad spectral region that shows three stages of development. This is attributed to the formation of defect clusters by a model of defect growth and also high fluence optical absorption studies. X-ray diffraction studies show

  2. Ion beam induced defects in solids studied by optical techniques

    Science.gov (United States)

    Comins, J. D.; Amolo, G. O.; Derry, T. E.; Connell, S. H.; Erasmus, R. M.; Witcomb, M. J.

    2009-08-01

    Optical methods can provide important insights into the mechanisms and consequences of ion beam interactions with solids. This is illustrated by four distinctly different systems. X- and Y-cut LiNbO 3 crystals implanted with 8 MeV Au 3+ ions with a fluence of 1 × 10 17 ions/cm 2 result in gold nanoparticle formation during high temperature annealing. Optical extinction curves simulated by the Mie theory provide the average nanoparticle sizes. TEM studies are in reasonable agreement and confirm a near-spherical nanoparticle shape but with surface facets. Large temperature differences in the nanoparticle creation in the X- and Y-cut crystals are explained by recrystallisation of the initially amorphised regions so as to recreate the prior crystal structure and to result in anisotropic diffusion of the implanted gold. Defect formation in alkali halides using ion beam irradiation has provided new information. Radiation-hard CsI crystals bombarded with 1 MeV protons at 300 K successfully produce F-type centres and V-centres having the I3- structure as identified by optical absorption and Raman studies. The results are discussed in relation to the formation of interstitial iodine aggregates of various types in alkali iodides. Depth profiling of I3- and I5- aggregates created in RbI bombarded with 13.6 MeV/A argon ions at 300 K is discussed. The recrystallisation of an amorphous silicon layer created in crystalline silicon bombarded with 100 keV carbon ions with a fluence of 5 × 10 17 ions/cm 2 during subsequent high temperature annealing is studied by Raman and Brillouin light scattering. Irradiation of tin-doped indium oxide (ITO) films with 1 MeV protons with fluences from 1 × 10 15 to 250 × 10 15 ions/cm -2 induces visible darkening over a broad spectral region that shows three stages of development. This is attributed to the formation of defect clusters by a model of defect growth and also high fluence optical absorption studies. X-ray diffraction studies show

  3. An improved optical flow tracking technique for real-time MR-guided beam therapies in moving organs

    Science.gov (United States)

    Zachiu, C.; Papadakis, N.; Ries, M.; Moonen, C.; de Senneville, B. Denis

    2015-12-01

    Magnetic resonance (MR) guided high intensity focused ultrasound and external beam radiotherapy interventions, which we shall refer to as beam therapies/interventions, are promising techniques for the non-invasive ablation of tumours in abdominal organs. However, therapeutic energy delivery in these areas becomes challenging due to the continuous displacement of the organs with respiration. Previous studies have addressed this problem by coupling high-framerate MR-imaging with a tracking technique based on the algorithm proposed by Horn and Schunck (H and S), which was chosen due to its fast convergence rate and highly parallelisable numerical scheme. Such characteristics were shown to be indispensable for the real-time guidance of beam therapies. In its original form, however, the algorithm is sensitive to local grey-level intensity variations not attributed to motion such as those that occur, for example, in the proximity of pulsating arteries. In this study, an improved motion estimation strategy which reduces the impact of such effects is proposed. Displacements are estimated through the minimisation of a variation of the H and S functional for which the quadratic data fidelity term was replaced with a term based on the linear L1norm, resulting in what we have called an L2-L1 functional. The proposed method was tested in the livers and kidneys of two healthy volunteers under free-breathing conditions, on a data set comprising 3000 images equally divided between the volunteers. The results show that, compared to the existing approaches, our method demonstrates a greater robustness to local grey-level intensity variations introduced by arterial pulsations. Additionally, the computational time required by our implementation make it compatible with the work-flow of real-time MR-guided beam interventions. To the best of our knowledge this study was the first to analyse the behaviour of an L1-based optical flow functional in an applicative context: real-time MR

  4. Cutting technique for reactor internals by laser beam

    International Nuclear Information System (INIS)

    Matsumoto, O.; Sugihara, M.; Matsuda, K.; Miya, K.

    1990-01-01

    At present in Japan the verification tests on the commercial nuclear power reactor decommissioning technology are being conducted as the project of The Ministry of International Trade and Industry by Nuclear Power Engineering Test Center. This paper summarizes the interim results of the verification test for the reactor core internals decommissioning technology, which is being conducted from 1986 as a theme of the above project. All core internals to be studied here are made of stainless steel, and the maximum wall thickness is about 500mm (the maximum one to be cut is about 300mm) for the PWR's, and about 100mm for the BWR's. Though the plasma cutting, arc saw cutting method, etc. have been studied u p to now as the cutting technology for decommissioning these core internals, the authors are carrying out the development and verification test of the cutting technology with the laser beam, which is expected to increase its power in future and can be applied to various materials

  5. Effect of dipole-quadrupole Robinson mode coupling upon the beam response to radio-frequency phase noise

    Directory of Open Access Journals (Sweden)

    R. A. Bosch

    2006-09-01

    Full Text Available In an electron storage ring, coupling between dipole and quadrupole Robinson oscillations modifies the spectrum of longitudinal beam oscillations driven by radio-frequency (rf generator phase noise. In addition to the main peak at the resonant frequency of the coupled dipole Robinson mode, another peak occurs at the resonant frequency of the coupled quadrupole mode. To describe these peaks analytically for a quadratic synchrotron potential, we include the dipole and quadrupole modes when calculating the beam response to generator noise. We thereby obtain the transfer function from generator-noise phase modulation to beam phase modulation with and without phase feedback. For Robinson-stable bunches confined in a synchrotron potential with a single minimum, the calculated transfer function agrees with measurements at the Aladdin 800-MeV electron storage ring. The transfer function is useful in evaluating phase feedback that suppresses Robinson oscillations in order to obtain quiet operation of an infrared beam line.

  6. A calculation technique of passing of a powerful relativistic beam through substance

    International Nuclear Information System (INIS)

    Pobitko, A.I.; Sal'nikov, L.I.; Sukhovitskij, E.Sh.

    1995-01-01

    The calculation algorithm of passing powerful relativistic beam through substance is developed. Algorithm of calculation is separated on the following problems: 1) a trial charge movement in electromagnetic field of the cylindrical geometry; 2) a computing of own electromagnetic field arising at movement of a particle heavy-current beam in a target; 3) accounting of an interaction of a beam with target atoms; 4) accounting of change of the target properties in a time; 5) geometry and construction of an iterative procedure of calculation. The calculation of passing heavy-current beams of charged particles for transient case is carried out by Monte Carlo method. A conclusion of equations of movement trial charge and technique of calculation own electromagnetic field of the powerful relativistic beam at passing through substance are resulted. 6 refs

  7. Nuclear techniques using radioactive beams for biophysical studies

    CERN Document Server

    Stachura, Monika Kinga

    Perturbed angular correlation of "-rays (PAC) spectroscopy and nuclear magnetic resonance measured by !-decay (betaNMR) spectroscopy are two very sensitive and, among life-scientists, infrequently encountered nuclear techniques. Both of them belong to the family of hyperfine techniques, which allow for measurements of the interactions of extra-nuclear electromagnetic fields with the nuclear moments. In this way - they can provide useful information about the local structure of the investigated systems. The first part of the work presented here focuses on investigating the fundamental chemistry of heavy metal ion - protein interactions mainly with PAC spectroscopy. A variety of questions concerning both the function of metal ions in natural systems and in synthetic biomolecules on the one hand and the toxic effects of some metal ions on the other were addressed, the results of which are described in four different papers. Paper I is a review article entitled ”Selected applications of perturbed angular correl...

  8. Rf transfer in the Coupled-Cavity Free-Electron Laser Two-Beam Accelerator

    International Nuclear Information System (INIS)

    Makowski, M.A.

    1991-01-01

    A significant technical problem associated with the Coupled-Cavity Free-Electron Laser Two-Beam Accelerator is the transfer of RF energy from the drive accelerator to the high-gradient accelerator. Several concepts have been advanced to solve this problem. This paper examines one possible solution in which the drive and high-gradient cavities are directly coupled to one another by means of holes in the cavity walls or coupled indirectly through a third intermediate transfer cavity. Energy cascades through the cavities on a beat frequency time scale which must be made small compared to the cavity skin time but large compared to the FEL pulse length. The transfer is complicated by the fact that each of the cavities in the system can support many resonant modes near the chosen frequency of operation. A generalized set of coupled-cavity equations has been developed to model the energy transfer between the various modes in each of the cavities. For a two cavity case transfer efficiencies in excess of 95% can be achieved. 3 refs., 2 figs

  9. Automation techniques applied to systematic studies of moderator coupling

    International Nuclear Information System (INIS)

    Ansell, S.; Garcia, J.F.; Bennington, S.M.; Picton, D.J.; Broome, T.

    2004-01-01

    We present new computation methods in which the geometry management of MCNPX input files can be automated. We demonstrate this method with respect to the target station 2 design at ISIS. The method presented is not a mathematically robust method, but by starting from a valid baseline model allows this model to be mutated in a reliable way. Those features that still need to be improved and added are discussed at the end. We use this method to show that a mixed lead/water pre-moderator gives a better neutron flux to radiation damage ratio for the coupled moderator. (orig.)

  10. Automation techniques applied to systematic studies of moderator coupling

    Energy Technology Data Exchange (ETDEWEB)

    Ansell, S; Garcia, J F; Bennington, S M; Picton, D J; Broome, T [Rutherford Appleton Lab, Chilton (United Kingdom)

    2004-03-01

    We present new computation methods in which the geometry management of MCNPX input files can be automated. We demonstrate this method with respect to the target station 2 design at ISIS. The method presented is not a mathematically robust method, but by starting from a valid baseline model allows this model to be mutated in a reliable way. Those features that still need to be improved and added are discussed at the end. We use this method to show that a mixed lead/water pre-moderator gives a better neutron flux to radiation damage ratio for the coupled moderator. (orig.)

  11. Phase aberrations and beam cleanup techniques in carbon-dioxide laser fusion systems

    International Nuclear Information System (INIS)

    Viswanathan, V.K.

    1981-01-01

    This paper describes the various carbon dioxide laser fusion systems at Los Alamos from the point of view of an optical designer. The types of phase aberrations present in these systems, as well as the beam cleanup techniques that can be used to improve the beam optical quality, are discussed. As this is a review article, some previously published results are also used where relevant

  12. Possible applications of the ion beams technique for investigations in the field of equation of state

    International Nuclear Information System (INIS)

    Kanel, G.I.; Fortov, V.E.; Baumung, K.; Bluhm, H.

    1998-01-01

    The shock wave generation through the interaction of a high-power ion beam with condensed targets is considered with a goal to reveal possible ways to study the equations of state of matter using ion beams. The equation of state is thought about in an extended interpretation including the relaxation processes, such as phase transitions, chemical reactions, and stress relaxation. Advantages of the beam-driven generation of the high-energy states and possible areas of competition with more conventional technique are discussed. (orig.)

  13. Vietnam Project For Production Of Radioactive Beam Based On ISOL Technique With The Dalat Reactor

    International Nuclear Information System (INIS)

    Le Hong Khiem; Phan Viet Cuong; Fadi Ibrahim

    2011-01-01

    The presence in Vietnam of Dalat nuclear reactor dedicated to fundamental studies is a unique opportunity to produce Radioactive Ion (RI) Beams with the fission of a 235 U induced by the thermal neutrons produced by the reactor. We propose to produce RI beams at the Dalat nuclear reactor using ISOL (Isotope Separation On-Line) technique. This project should be a unique opportunity for Vietnamese nuclear physics community to use its own facilities to produce RI beams for studying nuclear physics at an international level. (author)

  14. Coupled-Multiplier Accelerator Produces High-Power Electron Beams for Industrial Applications

    International Nuclear Information System (INIS)

    Hatridge, M.; McIntyre, P.; Roberson, S.; Sattarov, A.; Thomas, E.; Meitzler, Charles

    2003-01-01

    The coupled multiplier is a new approach to efficient generation of MeV d.c. power for accelerator applications. High voltage is produced by a series of modules, each of which consists of a high-power alternator, step-up transformer, and 3-phase multiplier circuit. The alternators are connected mechanically along a rotating shaft, and connected by insulating flexible couplers. This approach differs from all previous d.c. technologies in that power is delivered to the various stages of the system mechanically, rather than through capacitive or inductive electrical coupling. For this reason the capital cost depends linearly on required voltage and power, rather than quadratically as with conventional technologies. The CM technology enables multiple electron beams to be driven within a common supply and insulating housing. MeV electron beam is extremely effective in decomposing organic contaminants in water. A 1 MeV, 100 kW industrial accelerator using the CM technology has been built and is being installed for treatment of wastewater at a petrochemical plant

  15. Modulation Instability of Copropagating Optical Beams in Fractional Coupled Nonlinear Schrödinger Equations

    Science.gov (United States)

    Zhang, Jinggui

    2018-06-01

    In this paper, we investigate the dynamical behaviors of the modulation instability (MI) of copropagating optical beams in fractional coupled nonlinear Schrödinger equations (NLSE) with the aim of revealing some novel properties different from those in the conventional coupled NLSE. By applying the standard linear stability method, we first derive an expression for the gain resulting from the instability induced by cross-phase modulation (CPM) in the presence of the Lévy indexes related to fractional effects. It is found that the modulation instability of copropagating optical beams still occurs even in the fractional NLSE with self-defocusing nonlinearity. Then, the analysis of our results further reveals that such Lévy indexes increase the fastest growth frequency and the bandwidth of conventional instability not only for the self-focusing case but also for the self-defocusing case, but do not influence the corresponding maximum gain. Numerical simulations are performed to confirm theoretical predictions. These findings suggest that the novel fractional physical settings may open up new possibilities for the manipulation of MI and nonlinear waves.

  16. Arrays of suspended silicon nanowires defined by ion beam implantation: mechanical coupling and combination with CMOS technology

    Science.gov (United States)

    Llobet, J.; Rius, G.; Chuquitarqui, A.; Borrisé, X.; Koops, R.; van Veghel, M.; Perez-Murano, F.

    2018-04-01

    We present the fabrication, operation, and CMOS integration of arrays of suspended silicon nanowires (SiNWs). The functional structures are obtained by a top-down fabrication approach consisting in a resistless process based on focused ion beam irradiation, causing local gallium implantation and silicon amorphization, plus selective silicon etching by tetramethylammonium hydroxide, and a thermal annealing process in a boron rich atmosphere. The last step enables the electrical functionality of the irradiated material. Doubly clamped silicon beams are fabricated by this method. The electrical readout of their mechanical response can be addressed by a frequency down-mixing detection technique thanks to an enhanced piezoresistive transduction mechanism. Three specific aspects are discussed: (i) the engineering of mechanically coupled SiNWs, by making use of the nanometer scale overhang that it is inherently-generated with this fabrication process, (ii) the statistical distribution of patterned lateral dimensions when fabricating large arrays of identical devices, and (iii) the compatibility of the patterning methodology with CMOS circuits. Our results suggest that the application of this method to the integration of large arrays of suspended SiNWs with CMOS circuitry is interesting in view of applications such as advanced radio frequency band pass filters and ultra-high-sensitivity mass sensors.

  17. Transverse to longitudinal phase space coupling in an electron beam for suppression of microbunching instability

    Directory of Open Access Journals (Sweden)

    Dazhang Huang

    2016-10-01

    Full Text Available The microbunching instability developed during the beam compression process in the linear accelerator (LINAC of a free-electron laser (FEL facility has always been a problem that degrades the lasing performance, and even no FEL is able to be produced if the beam quality is destroyed too much by the instability. A common way to suppress the microbunching instability is to introduce extra uncorrelated energy spread by the laser heater that heats the beam through the interaction between the electron and laser beam, as what has been successfully implemented in the Linac Coherent Light Source and Fermi@Elettra. In this paper, a simple and effective scheme is proposed to suppress the microbunching instability by adding two transverse gradient undulators (TGU before and after the magnetic bunch compressor. The additional uncorrelated energy spread and the density mixing from the transverse spread brought up by the first TGU results in significant suppression of the instability. Meanwhile, the extra slice energy spread and the transverse emittance can also be effectively recovered by the second TGU. The magnitude of the suppression can be easily controlled by varying the strength of the magnetic fields of the TGUs. Theoretical analysis and numerical simulations demonstrate the capability of the proposed technique in the LINAC of an x-ray free-electron laser facility.

  18. Diffractive beam shaping, tracking and coupling for wave-guided optical waveguides (WOWs)

    DEFF Research Database (Denmark)

    Villangca, Mark Jayson; Bañas, Andrew Rafael; Aabo, Thomas

    2014-01-01

    techniques to create multiple focal spots that can be coupled into light manipulated WOWs. This is done by using a spatial light modulator to project the necessary phase to generate the multiple coupling light spots. We incorporate a diffractive setup in our Biophotonics Workstation (BWS) and demonstrate......We have previously proposed and demonstrated the targeted-light delivery capability of wave-guided optical waveguides (WOWs). The full strength of this structure-mediated paradigm can be harnessed by addressing multiple WOWs and manipulating them to work in tandem. We propose the use of diffractive...

  19. Coupling between shear and bending in the analysis of beam problems: Planar case

    Science.gov (United States)

    Shabana, Ahmed A.; Patel, Mohil

    2018-04-01

    The interpretation of invariants, such as curvatures which uniquely define the bending and twist of space curves and surfaces, is fundamental in the formulation of the beam and plate elastic forces. Accurate representations of curve and surface invariants, which enter into the definition of the strain energy equations, is particularly important in the case of large displacement analysis. This paper discusses this important subject in view of the fact that shear and bending are independent modes of deformation and do not have kinematic coupling; this is despite the fact that kinetic coupling may exist. The paper shows, using simple examples, that shear without bending and bending without shear at an arbitrary point and along a certain direction are scenarios that higher-order finite elements (FE) can represent with a degree of accuracy that depends on the order of interpolation and/or mesh size. The FE representation of these two kinematically uncoupled modes of deformation is evaluated in order to examine the effect of the order of the polynomial interpolation on the accuracy of representing these two independent modes. It is also shown in this paper that not all the curvature vectors contribute to bending deformation. In view of the conclusions drawn from the analysis of simple beam problems, the material curvature used in several previous investigations is evaluated both analytically and numerically. The problems associated with the material curvature matrix, obtained using the rotation of the beam cross-section, and the fundamental differences between this material curvature matrix and the Serret-Frenet curvature matrix are discussed.

  20. Quantification of EFTEM elemental maps using ion beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, J.K.N. [Institut fuer Physik, Universitaet Augsburg, 86135 Augsburg (Germany)]. E-mail: lindner@physik.uni-augsburg.de; Haeberlen, M. [Institut fuer Physik, Universitaet Augsburg, 86135 Augsburg (Germany); Schwarz, F. [Institut fuer Physik, Universitaet Augsburg, 86135 Augsburg (Germany); AxynTeC Duennschichttechnik GmbH, Am Mittleren Moos 49, 86167 Augsburg (Germany); Thorwarth, G. [Institut fuer Physik, Universitaet Augsburg, 86135 Augsburg (Germany); AxynTeC Duennschichttechnik GmbH, Am Mittleren Moos 49, 86167 Augsburg (Germany); Stritzker, B. [Institut fuer Physik, Universitaet Augsburg, 86135 Augsburg (Germany); Hammerl, C. [AxynTeC Duennschichttechnik GmbH, Am Mittleren Moos 49, 86167 Augsburg (Germany); Assmann, W. [Sektion Physik der LMU Muenchen, Am Coulombwall 6, 85748 Garching (Germany)

    2006-08-15

    In this paper the nanometric spatial resolution capabilities of energy filtered cross-sectional transmission electron microscopy (EFTEM) element mapping are complemented with the ability of elastic recoil detection analysis (ERDA) and Rutherford backscattering spectroscopy (RBS) to perform absolute and standardless composition analysis of light and heavy elements. The strength of this combination of techniques is examplified by means of several {mu}m thick multielemental wear protection multilayer stacks of diamond-like carbon (DLC) and silicon compounds with individual sublayers of few ten nanometer thickness, which were analysed with respect to their composition. The result are quantitative high-resolution 2-dimensional distributions of different elements in the several {mu}m thick film sandwiches.

  1. Discharge source coupled to a deceleration unit for anion beam generation: Application to H{sub 2}{sup −} photodetachment

    Energy Technology Data Exchange (ETDEWEB)

    Rudnev, V.; Ureña, A. González [Unidad de Láseres y Haces Moleculares, Instituto Pluridisciplinar, Universidad Complutense, Juan XXIII-1, Madrid 28040 (Spain)

    2013-12-15

    A cathode discharge source coupled to a deceleration unit for anion beam generation is described. The discharge source, made of stainless steel or duralumin electrodes and Macor insulators, is attached to the exit nozzle valve plate at one end, and to an Einzel lens to the other end. Subsequently, a cylindrical retardation unit is attached to the Einzel lens to decelerate the ions in order to optimize the laser beam interaction time required for spectroscopic investigations. The compact device is able to produce beam intensities of the order of 2 × 10{sup 12} anions/cm{sup 2} s and 20 μrad of angular divergence with kinetic energies ranging from 30 to 120 eV. Using distinct gas mixtures for the supersonic expansion together with a linear time-of-flight spectrometer, anions of great relevance in molecular astrophysics like, for example, H{sub 2}{sup −}, C{sub 3}H{sup −}, C{sub 2}{sup −}, C{sub 2}H{sup −}, HCN{sub 2}{sup −}, CO{sub 2}{sup −}, CO{sub 2}H{sup −}, C{sub 4}{sup −}, C{sub 4}H{sup −}, C{sub 5}H{sub 4}{sup −}, C{sub 5}H{sub 6}{sup −}, C{sub 7}N{sup −}, and C{sub 10}N{sup −} were produced. Finally, in order to demonstrate the capability of the experimental technique the photodetachment cross-section of the metastable H{sub 2}{sup −}, predominantly in the (v = 0, J = 26) state, was measured following laser excitation at λ{sub exc}= 565 nm obtaining a value of σ{sub ph}= 0.04 Å. To the best of our knowledge, it is the first time that this anion cross-section has been measured.

  2. Improvements in technique for determining the surfactant penetration in hair fibres using scanning ion beam analyses

    International Nuclear Information System (INIS)

    Hollands, R.; Clough, A.S.; Meredith, P.

    1999-01-01

    The penetration abilities of surfactants need to be known by companies manufacturing hair-care products. In this work three complementary techniques were used simultaneously - PIXE, NRA and RBS - to measure the penetration of a surfactant, which had been deuterated, into permed hair fibres. Using a scanning micro-beam of 2 MeV 3 He ions 2-dimensional concentration maps were obtained which showed whether the surfactant penetrated the fibre or just stayed on the surface. This is the first report of the use of three simultaneous scattering techniques with a scanning micro-beam. (author)

  3. A beam-based alignment technique for correction of accelerator structure misalignments

    International Nuclear Information System (INIS)

    Kubo, K.; Raubenheimer, T.O.

    1994-08-01

    This paper describes a method of reducing the transverse emittance dilution in linear colliders due to transverse wakefields arising-from misaligned accelerator structures. The technique is a generalization of the Wake-Free correction algorithm. The structure alignment errors are measured locally by varying the bunch charge and/or bunch length and measuring the change in the beam trajectory. The misalignments can then be corrected by varying the beam trajectory or moving structures. The results of simulations are presented demonstrating the viability of the technique

  4. Extending the reach of strong-coupling: an iterative technique for Hamiltonian lattice models

    International Nuclear Information System (INIS)

    Alberty, J.; Greensite, J.; Patkos, A.

    1983-12-01

    The authors propose an iterative method for doing lattice strong-coupling-like calculations in a range of medium to weak couplings. The method is a modified Lanczos scheme, with greatly improved convergence properties. The technique is tested on the Mathieu equation and on a Hamiltonian finite-chain XY model, with excellent results. (Auth.)

  5. The edge transient-current technique (E-TCT) with high energy hadron beam

    Energy Technology Data Exchange (ETDEWEB)

    Gorišek, Andrej; Cindro, Vladimir; Kramberger, Gregor; Mandić, Igor [J. Stefan Institute, Ljubljana (Slovenia); Mikuž, Marko [J. Stefan Institute, Ljubljana (Slovenia); University of Ljubljana (Slovenia); Muškinja, Miha; Zavrtanik, Marko [J. Stefan Institute, Ljubljana (Slovenia)

    2016-09-21

    We propose a novel way to investigate the properties of silicon and CVD diamond detectors for High Energy Physics experiments complementary to the already well-established E-TCT technique using laser beam. In the proposed setup the beam of high energy hadrons (MIPs) is used instead of laser beam. MIPs incident on the detector in the direction parallel to the readout electrode plane and perpendicular to the edge of the detector. Such experiment could prove very useful to study CVD diamond detectors that are almost inaccessible for the E-TCT measurements with laser due to large band-gap as well as to verify and complement the E-TCT measurements of silicon. The method proposed is being tested at CERN in a beam of 120 GeV hadrons using a reference telescope with track resolution at the DUT of few μm. The preliminary results of the measurements are presented.

  6. A control technique of oxygen contamination by Ga beam irradiation in InN MOMBE growth

    International Nuclear Information System (INIS)

    Isamoto, K.; Uesaka, Y.; Yamamoto, A.; Hashimoto, A.

    2006-01-01

    We have investigated about a control technique of oxygen contamination into the InN layers by simultaneous irradiation of Ga beam during RF-MOMBE growth using the combination of the TMIn and the RF-plasma nitrogen sources. Red shifts of the band gap energy and the improvement of the electrical properties have been achieved by the Ga beam irradiation. The suppression mechanism of the oxygen contamination has been discussed from the experimental results of the InN growth by the RF-MOMBE with the Ga beam irradiation. The present results strongly indicate that the simultaneous irradiation of the Ga beam would be useful to suppress the oxygen contamination into the InN layers during the growth. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. An analytical simulation technique for cone-beam CT and pinhole SPECT

    International Nuclear Information System (INIS)

    Zhang Xuezhu; Qi Yujin

    2011-01-01

    This study was aimed at developing an efficient simulation technique with an ordinary PC. The work involved derivation of mathematical operators, analytic phantom generations, and effective analytical projectors developing for cone-beam CT and pinhole SPECT imaging. The computer simulations based on the analytical projectors were developed by ray-tracing method for cone-beam CT and voxel-driven method for pinhole SPECT of degrading blurring. The 3D Shepp-Logan, Jaszczak and Defrise phantoms were used for simulation evaluations and image reconstructions. The reconstructed phantom images were of good accuracy with the phantoms. The results showed that the analytical simulation technique is an efficient tool for studying cone-beam CT and pinhole SPECT imaging. (authors)

  8. Silicon-on-insulator-based polarization-independent 1×3 broadband beam splitter with adiabatic coupling

    Science.gov (United States)

    Gong, Yuanhao; Liu, Lei; Chang, Limin; Li, Zhiyong; Tan, Manqing; Yu, Yude

    2017-10-01

    We propose and numerically simulate a polarization-independent 1×3 broadband beam splitter based on silicon-on-insulator (SOI) technology with adiabatic coupling. The designed structure is simulated by beam-propagation-method (BPM) and gets simulated transmission uniformity of three outputs better than 0.3dB for TE-polarization and 0.8dB for TM-polarization in a broadband of 180nm.

  9. Optimized coupling of cold atoms into a fiber using a blue-detuned hollow-beam funnel

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, Jerome; Light, Philip S.; Kashyap, Raman; Luiten, Andre N. [Frequency Standards and Metrology Group, School of Physics, University of Western Australia, Western Australia 6009, Perth (Australia); Department of Engineering Physics, Ecole Polytechnique de Montreal, Montreal, Quebec, Canada H3C 3A7 (Canada); Frequency Standards and Metrology, School of Physics, University of Western Australia, Western Australia 6009, Perth (Australia)

    2011-11-15

    We theoretically investigate the process of coupling cold atoms into the core of a hollow-core photonic-crystal optical fiber using a blue-detuned Laguerre-Gaussian beam. In contrast to the use of a red-detuned Gaussian beam to couple the atoms, the blue-detuned hollow beam can confine cold atoms to the darkest regions of the beam, thereby minimizing shifts in the internal states and making the guide highly robust to heating effects. This single optical beam is used as both a funnel and a guide to maximize the number of atoms into the fiber. In the proposed experiment, Rb atoms are loaded into a magneto-optical trap (MOT) above a vertically oriented optical fiber. We observe a gravito-optical trapping effect for atoms with high orbital momentum around the trap axis, which prevents atoms from coupling to the fiber: these atoms lack the kinetic energy to escape the potential and are thus trapped in the laser funnel indefinitely. We find that by reducing the dipolar force to the point at which the trapping effect just vanishes, it is possible to optimize the coupling of atoms into the fiber. Our simulations predict that by using a low-power (2.5 mW) and far-detuned (300 GHz) Laguerre-Gaussian beam with a 20-{mu}m-radius core hollow fiber, it is possible to couple 11% of the atoms from a MOT 9 mm away from the fiber. When the MOT is positioned farther away, coupling efficiencies over 50% can be achieved with larger core fibers.

  10. Characterization of the Plasma Edge for Technique of Atomic Helium Beam in the CIEMAT Fusion Device

    International Nuclear Information System (INIS)

    Hidalgo, A.

    2003-01-01

    In this report, the measurement of Electron Temperature and Density in the Boundary Plasma of TJ-II with a Supersonic Helium Beam Diagnostic and work devoted to the upgrading of this technique are described. Also, simulations of Laser Induced Fluorescence (LIF) studies of level populations of electronically excited He atoms are shown. This last technique is now being installed in the CIEMAT fusion device. (Author )

  11. Implementation of intra-cavity beam shaping technique to enhance pump efficiency

    CSIR Research Space (South Africa)

    Litvin, IA

    2012-02-01

    Full Text Available In this work the author proposes an implementation of a new intra-cavity beam shaping technique to vary the intensity distribution of the fundamental mode in a resonator cavity while maintaining a constant intensity distribution at the output...

  12. Instability and dynamics of two nonlinearly coupled intense laser beams in a quantum plasma

    International Nuclear Information System (INIS)

    Wang Yunliang; Shukla, P. K.; Eliasson, B.

    2013-01-01

    We consider nonlinear interactions between two relativistically strong laser beams and a quantum plasma composed of degenerate electron fluids and immobile ions. The collective behavior of degenerate electrons is modeled by quantum hydrodynamic equations composed of the electron continuity, quantum electron momentum (QEM) equation, as well as the Poisson and Maxwell equations. The QEM equation accounts the quantum statistical electron pressure, the quantum electron recoil due to electron tunneling through the quantum Bohm potential, electron-exchange, and electron-correlation effects caused by electron spin, and relativistic ponderomotive forces (RPFs) of two circularly polarized electromagnetic (CPEM) beams. The dynamics of the latter are governed by nonlinear wave equations that include nonlinear currents arising from the relativistic electron mass increase in the CPEM wave fields, as well as from the beating of the electron quiver velocity and electron density variations reinforced by the RPFs of the two CPEM waves. Furthermore, nonlinear electron density variations associated with the driven (by the RPFs) quantum electron plasma oscillations obey a coupled nonlinear Schrödinger and Poisson equations. The nonlinearly coupled equations for our purposes are then used to obtain a general dispersion relation (GDR) for studying the parametric instabilities and the localization of CPEM wave packets in a quantum plasma. Numerical analyses of the GDR reveal that the growth rate of a fastest growing parametrically unstable mode is in agreement with the result that has been deduced from numerical simulations of the governing nonlinear equations. Explicit numerical results for two-dimensional (2D) localized CPEM wave packets at nanoscales are also presented. Possible applications of our investigation to intense laser-solid density compressed plasma experiments are highlighted.

  13. Squids, snakes, and polarimeters: A new technique for measuring the magnetic moments of polarized beams

    International Nuclear Information System (INIS)

    Cameron, P.R.; Luccio, A.U.; Shea, T.J.; Tsoupas, N.; Goldberg, D.A.

    1997-01-01

    Effective polarimetry at high energies in hadron and lepton synchrotrons has been a long-standing and difficult problem. In synchrotrons with polarized beams it is possible to cause the direction of the polarization vector of a given bunch to alternate at a frequency which is some subharmonic of the rotation frequency. This can result in the presence of lines in the beam spectrum which are due only to the magnetic moment of the beam and which are well removed from the various lines due to the charge of the beam. The magnitude of these lines can be calculated from first principles. They are many orders of magnitude weaker than the Schottky signals. Measurement of the magnitude of one of these lines would be an absolute measurement of beam polarization. For measuring magnetic field, the Superconducting Quantum Interference Device, or squid, is about five orders of magnitude more sensitive than any other transducer. Using a squid, such a measurement might be accomplished with the proper combination of shielding, pickup loop design, and filtering. The resulting instrument would be fast, non-destructive, and comparatively cheap. In addition, techniques developed in the creation of such an instrument could be used to measure the Schottky spectrum in unprecedented detail. We present specifics of a polarimeter design for the Relativistic Heavy Ion Collider (RHIC) and briefly discuss the possibility of using this technique to measure polarization at high-energy electron machines like LEP and HERA. copyright 1997 American Institute of Physics

  14. Statistical signal processing techniques for coherent transversal beam dynamics in synchrotrons

    Energy Technology Data Exchange (ETDEWEB)

    Alhumaidi, Mouhammad

    2015-03-04

    identifying and analyzing the betatron oscillation sourced from the kick based on its mixing and temporal patterns. The accelerator magnets can generate unwanted spurious linear and non-linear fields due to fabrication errors or aging. These error fields in the magnets can excite undesired resonances leading together with the space charge tune spread to long term beam losses and reducing dynamic aperture. Therefore, the knowledge of the linear and non-linear magnets errors in circular accelerator optics is very crucial for controlling and compensating resonances and their consequent beam losses and beam quality deterioration. This is indispensable, especially for high beam intensity machines. Fortunately, the relationship between the beam offset oscillation signals recorded at the BPMs is a manifestation of the accelerator optics, and can therefore be exploited in the determination of the optics linear and non-linear components. Thus, beam transversal oscillations can be excited deliberately for purposes of diagnostics operation of particle accelerators. In this thesis, we propose a novel method for detecting and estimating the optics lattice non-linear components located in-between the locations of two BPMs by analyzing the beam offset oscillation signals of a BPMs-triple containing these two BPMs. Depending on the non-linear components in-between the locations of the BPMs-triple, the relationship between the beam offsets follows a multivariate polynomial accordingly. After calculating the covariance matrix of the polynomial terms, the Generalized Total Least Squares method is used to find the model parameters, and thus the non-linear components. A bootstrap technique is used to detect the existing polynomial model orders by means of multiple hypothesis testing, and determine confidence intervals for the model parameters.

  15. RF photo-injector beam energy distribution studies by slicing technique

    Science.gov (United States)

    Filippetto, D.; Bellaveglia, M.; Musumeci, P.; Ronsivalle, C.

    2009-07-01

    The SPARC photo-injector is an R&D facility dedicated to the production of high brightness electron beams for radiation generation via FEL or Thomson scattering processes. It is the prototype injector for the recently approved SPARX project, aiming at the construction in the Frascati/University of Rome Tor Vergata area of a new high brightness electron linac for the generation of SASE-FEL radiation in the 1-10 nm wavelength range. The first phase of the SPARC project has been dedicated to the e-beam source characterization; the beam transverse and longitudinal parameters at the exit of the gun have been measured, and the photo-injector settings optimized to achieve best performance. Several beam dynamics topics have been experimentally studied in this first phase of operation, as, for example, the effect of photocathode driver laser beam shaping and the evolution of the beam transverse emittance. These studies have been made possible by the use of a novel diagnostic tool, the " emittance-meter" which enables the measurement of the transverse beam parameters at different positions along the propagation axis in the very interesting region at the exit of the RF gun. The new idea of extending the e-meter capabilities came out more recently. Information on the beam longitudinal phase space and correlations with the transverse planes can be retrieved by the slicing technique. In this paper, we illustrate the basic concept of the measurement together with simulations that theoretically validate the methodology. Some preliminary results are discussed and explained with the aid of code simulations.

  16. Introduction to analytical techniques of beam-target interactions and resolutions

    International Nuclear Information System (INIS)

    Ruste, J.

    1995-08-01

    For several years, new analysis and observation techniques have been developed, which have considerably improved material research. Almost all these techniques are based on the interaction of a beam of 'primary particles' (electrons, photons, ions, particles, etc) with target. Correct and appropriate use of these techniques requires a good knowledge of these interactions and their consequences (emissions of 'secondary particles', modifications of the primary beam and target, etc). The first part of this report deals with the radiation/material interactions according to the nature of the radiation and its energy. The nature and consequences of the interaction of an electromagnetic wave, a beam of electrons, ions and neutrons are examined over an extended range of energy from MeV to MeV. Certain notions such as the analysis area, spatial resolutions or limits of detection can also be defined. In the second part, some of the most important and widespread techniques of analysis and observation are compared in terms of properties and performance. In particular, there is a brief principle of the technique, nature of the data obtained, spatial resolution, and the limits of detection with today's methods permit. (author). 5 refs., 23 figs., 9 tabs

  17. A novel efficient coupled polynomial field interpolation scheme for higher order piezoelectric extension mode beam finite elements

    International Nuclear Information System (INIS)

    Sulbhewar, Litesh N; Raveendranath, P

    2014-01-01

    An efficient piezoelectric smart beam finite element based on Reddy’s third-order displacement field and layerwise linear potential is presented here. The present formulation is based on the coupled polynomial field interpolation of variables, unlike conventional piezoelectric beam formulations that use independent polynomials. Governing equations derived using a variational formulation are used to establish the relationship between field variables. The resulting expressions are used to formulate coupled shape functions. Starting with an assumed cubic polynomial for transverse displacement (w) and a linear polynomial for electric potential (φ), coupled polynomials for axial displacement (u) and section rotation (θ) are found. This leads to a coupled quadratic polynomial representation for axial displacement (u) and section rotation (θ). The formulation allows accommodation of extension–bending, shear–bending and electromechanical couplings at the interpolation level itself, in a variationally consistent manner. The proposed interpolation scheme is shown to eliminate the locking effects exhibited by conventional independent polynomial field interpolations and improve the convergence characteristics of HSDT based piezoelectric beam elements. Also, the present coupled formulation uses only three mechanical degrees of freedom per node, one less than the conventional formulations. Results from numerical test problems prove the accuracy and efficiency of the present formulation. (paper)

  18. Neutron Spectroscopy for pulsed beams with frame overlap using a double time-of-flight technique

    Science.gov (United States)

    Harrig, K. P.; Goldblum, B. L.; Brown, J. A.; Bleuel, D. L.; Bernstein, L. A.; Bevins, J.; Harasty, M.; Laplace, T. A.; Matthews, E. F.

    2018-01-01

    A new double time-of-flight (dTOF) neutron spectroscopy technique has been developed for pulsed broad spectrum sources with a duty cycle that results in frame overlap, where fast neutrons from a given pulse overtake slower neutrons from previous pulses. Using a tunable beam at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory, neutrons were produced via thick-target breakup of 16 MeV deuterons on a beryllium target in the cyclotron vault. The breakup spectral shape was deduced from a dTOF measurement using an array of EJ-309 organic liquid scintillators. Simulation of the neutron detection efficiency of the scintillator array was performed using both GEANT4 and MCNP6. The efficiency-corrected spectral shape was normalized using a foil activation technique to obtain the energy-dependent flux of the neutron beam at zero degrees with respect to the incoming deuteron beam. The dTOF neutron spectrum was compared to spectra obtained using HEPROW and GRAVEL pulse height spectrum unfolding techniques. While the unfolding and dTOF results exhibit some discrepancies in shape, the integrated flux values agree within two standard deviations. This method obviates neutron time-of-flight spectroscopy challenges posed by pulsed beams with frame overlap and opens new opportunities for pulsed white neutron source facilities.

  19. A novel technique for tuning of co-axial cavity of multi-beam klystron

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Sukalyan, E-mail: sstechno18@gmail.com; Bandyopadhyay, Ayan Kumar; Pal, Debashis; Kant, Deepender; Joshi, Lalit Mohan; Kumar, Bijendra; Meena, Rakesh; Rawat, Vikram [Microwave Tubes Division, CSIR-CEERI, Pilani, Rajasthan-333031 (India)

    2016-03-09

    Multi-beam Klystrons (MBKs) have gained wide acceptances in the research sector for its inherent advantages. But developing a robust tuning technique for an MBK cavity of coaxial type has still remained a challenge as these designs are very prone to suffer from asymmetric field distribution with inductive tuning of the cavity. Such asymmetry leads to inhomogeneous beam-wave interaction, an undesirable phenomenon. Described herein is a new type of coaxial cavity that has the ability to suppress the asymmetry, thereby allowing tuning of the cavity with a single tuning post.

  20. Site control technique for quantum dots using electron beam induced deposition

    Energy Technology Data Exchange (ETDEWEB)

    Iizuka, Kanji; Jung, JaeHun; Yokota, Hiroshi [Nippon Institute of Technology, 4-1 Gakuendai, Miyashiro, Minami-saitama, Saitama 3458501 (Japan)

    2014-05-15

    To develop simple and high throughput sit definition technique for quantum dots (QDs), the electron beam induced deposition (EBID) method was used as desorption guide of phosphorus atoms form InP substrate. As the results one or a few indium (In) droplets (DLs) were created in the carbon grid pattern by thermal annealing at a temperature of 450°C for 10 min in the ultra high vacuum condition. The size of In DLs was larger than QDs, but arsenide DLs by molecular beam in growth chamber emitted wavelength of 1.028μm at 50K by photoluminescence measurement.

  1. Site control technique for quantum dots using electron beam induced deposition

    International Nuclear Information System (INIS)

    Iizuka, Kanji; Jung, JaeHun; Yokota, Hiroshi

    2014-01-01

    To develop simple and high throughput sit definition technique for quantum dots (QDs), the electron beam induced deposition (EBID) method was used as desorption guide of phosphorus atoms form InP substrate. As the results one or a few indium (In) droplets (DLs) were created in the carbon grid pattern by thermal annealing at a temperature of 450°C for 10 min in the ultra high vacuum condition. The size of In DLs was larger than QDs, but arsenide DLs by molecular beam in growth chamber emitted wavelength of 1.028μm at 50K by photoluminescence measurement

  2. Nuclear analytical techniques with neutron beams at the Univ. of Texas at Austin

    International Nuclear Information System (INIS)

    Uenlue, K.; Wehring, B.W.

    1996-01-01

    Neutron beams produced by nuclear research reactors can be used for analytical chemical analysis by measuring nuclear radiation produced by neutron capture. Prompt gamma activation analysis (PGAA) and neutron depth profiling (NDP) are two such analytical techniques. For the last three decades, these techniques have been applied at a number of research reactors around the world. Within the last 4 yr, we have developed NDP and PGAA facilities at The University of Texas at Austin research reactor, a 1-MW TRIGA Mark II reactor. Brief descriptions of the facilities and summaries of activities for these analytical techniques at the University of Texas at Austin are provided in this paper

  3. Comparison of Techniques to Reduce Bremsstrahlung Background Radiation from Monoenergetic Photon Beams

    International Nuclear Information System (INIS)

    Johnson, M; McNabb, D

    2006-01-01

    An important applied technology is a tunable mono-energetic photon source [1]. These sources are made of relativistic electron accelerators coupled to low-energy lasers, which produce high-energy, mono-energetic-rays. One challenge associated with systems such as this is a continuum of bremsstrahlung background created when an electron beam passes through an aperture of some sort and the electron bunch or its halo impinges on the aperture pictured in figure 1. For instance, in the current T-REX [1] design for the interaction point between the laser- and electron-beam, the electron-beam passes through the center of a mirror used to reflect the laser. There is a potential with this design that bremsstrahlung radiation may be produced at the edges of the mirror openings and contaminate the mono-energetic photon beam. Certain applications [2] may be sensitive to this contamination. To reduce the bremsstrahlung contaminate a collimator (thickness ∼24in. (calculated from XCOM database [3]) to attenuate by a factor of 10 -3 the 112MeV photons expected in the T-REX demonstration [1]) is situated between the aperture and target. To maximize the brightness of the photon-beam, the collimator opening must be no less than the size of the photon-beam spot size expected to be about 1mm. This fixes the collimator opening. a priori the aperture size must be greater than the collimator opening and is a function distance between the aperture and collimator. In this paper we focus on two approaches to estimate the aperture size, given a collimator and a target whose sizes and distances from the aperture are given. In the next section we will discuss these approaches

  4. Beam profile measurements on the advanced test accelerator using optical techniques

    International Nuclear Information System (INIS)

    Chong, Y.P.; Kalibjian, R.; Cornish, J.P.; Kallman, J.S.; Donnelly, D.

    1986-01-01

    Beam current density profiles of ATA have been measured both spatially and temporally using a number of diagnostics. An extremely important technique involves measuring optical emissions from either a target foil inserted into the beam path or gas atoms and molecules excited by beam electrons. This paper describes the detection of the optical emission. A 2-D gated television camera with a single or dual micro-channel-plate (MCP) detector for high gain provides excellent spatial and temporal resolution. Measurements are routinely made with resolutions of 1 mm and 5 ns respectively. The optical line of sight allows splitting part of the signal to a streak camera or photometer for even higher time resolution

  5. Characterization of beam dynamics in the APS injector rings using time-resolved imaging techniques

    International Nuclear Information System (INIS)

    Yang, B.X.; Lumpkin, A.H.; Borland, M.

    1997-01-01

    Images taken with streak cameras and gated intensified cameras with both time (longitudinal) and spatial (transverse) resolution reveal a wealth of information about circular accelerators. The authors illustrate a novel technique by a sequence of dual-sweep streak camera images taken at a high dispersion location in the booster synchrotron, where the horizontal coordinate is strongly correlated with the particle energy and the open-quotes top-viewclose quotes of the beam gives a good approximation to the particle density distribution in the longitudinal phase space. A sequence of top-view images taken fight after injection clearly shows the beam dynamics in the phase space. We report another example from the positron accumulator ring for the characterization of its beam compression bunching with the 12th harmonic rf

  6. Estimating the vibration level of an L-shaped beam using power flow techniques

    Science.gov (United States)

    Cuschieri, J. M.; Mccollum, M.; Rassineux, J. L.; Gilbert, T.

    1986-01-01

    The response of one component of an L-shaped beam, with point force excitation on the other component, is estimated using the power flow method. The transmitted power from the source component to the receiver component is expressed in terms of the transfer and input mobilities at the excitation point and the joint. The response is estimated both in narrow frequency bands, using the exact geometry of the beams, and as a frequency averaged response using infinite beam models. The results using this power flow technique are compared to the results obtained using finite element analysis (FEA) of the L-shaped beam for the low frequency response and to results obtained using statistical energy analysis (SEA) for the high frequencies. The agreement between the FEA results and the power flow method results at low frequencies is very good. SEA results are in terms of frequency averaged levels and these are in perfect agreement with the results obtained using the infinite beam models in the power flow method. The narrow frequency band results from the power flow method also converge to the SEA results at high frequencies. The advantage of the power flow method is that detail of the response can be retained while reducing computation time, which will allow the narrow frequency band analysis of the response to be extended to higher frequencies.

  7. Z-transform description of feedback acting on a coupled beam

    International Nuclear Information System (INIS)

    Talman, R.

    1993-01-01

    The power of the formalism of digital control systems for the analysis and cure of accelerator instabilities is demonstrated. The Z-transform can be said to be even more appropriate for accelerators than it is for digital control circuits because a beam position monitor (BPM) is inherently restricted to sampling once per turn and there is no possibility of obtaining more nearly continuous-time performance by increasing the sampling rate. Also interactions of a beam bunch with a fixed structure in the accelerator can most accurately be described as a sampling process. The traditional formalisms of accelerator physics and digital control systems contain numerous results which can be seen to be the same after having deciphered the differences of terminology, but once that is done standard results from the theory of control system can be applied to accelerator problems. An important requirement is to describe the betatron motion by a difference equation-coupled motion requires a fourth order difference equation. These equations are handled easily by the Z-transform. In the analysis of servomechanisms with sampling elements the Z-transform plays the same role as does the Laplace transform L in the analysis of time-continuous servomechanisms. Just as feedback stabilization of analog circuits against instability can be achieved by adjusting the positions in the complex s plane of the poles of L(s), so also do the poles in the complex z plane of Z(z) have a similar interpretation in accelerators. An incidental dividend accompanying this approach is the mathematically satisfactory generalization of ''Courant-Snyder formalism'' to include damping

  8. TOF technique for laser-driven proton beam diagnostics for the ELIMED beamline

    International Nuclear Information System (INIS)

    Milluzzo, G.; Scuderi, V.; Amico, A.G.; Cirrone, G.A.P.; Cuttone, G.; Larosa, G.; Leanza, R.; Petringa, G.; Pipek, J.; Romano, F.; Napoli, M. De; Dostal, J.; Margarone, D.; Schillaci, F.; Velyhan, A.

    2017-01-01

    The Time of Flight (TOF) method for laser-driven ion beam diagnostics has been extensively investigated so far for low energy ion diagnostics and several works, reported in literature [1,2], have shown its efficiency in the measurement of particle beam characteristics such as ion species, energy spectrum and current. Moreover, such technique allows obtaining a shot-to-shot on-line monitoring of optically accelerated particles, necessary to control the reproducibility of the accelerated beam and to deliver a beam suitable for any kind of applications. For this reason, the ELIMED beamline [3,4], which will be entirely developed at INFN-LNS and installed in 2017 within the ion beamline ELIMAIA (ELI Multidisciplinary Applications of laser-Ion Acceleration) experimental hall at ELI-Beamlines in Prague, will be equipped with an on-line diagnostics system composed by silicon carbide and diamond detectors, using the TOF technique. In this contribution, the procedure developed for TOF signal analysis will be briefly reported.

  9. Minimal interference beam size/profile measurement techniques applicable to the Collider

    International Nuclear Information System (INIS)

    Nexsen, W.; Dutt, S.; Kauffmann, S.; Lebedev, V.; Maschke, A.; Mokhov, N.; Richardson, R.; Tsyganov, E.; Zinchenko, A.

    1993-05-01

    The imaging of synchrotron radiation (SR) has been suggested as a technique for providing a continuous, non-interfering monitor of the beam profile in the Collider rings at the Superconducting Super Collider. A closer examination has raised questions concerning the applicability of SR imaging in this case because of the diffraction broadening of the image, the requirements for axial space and location in the lattice, and the complexity of the system. We have surveyed the known, alternative, minimal interference techniques for measuring beam size and have evaluated them for possible Collider usage. We conclude that of the approaches that appear feasible, all require at least some development for our usage and that the development of an electron beam probe offers the best promise. We recommend that flying wires be used for cross-checking and calibrating the electron beam probe diagnostic and for luminosity measurements when the highest accuracy is required, but flying wires should not be used as the primary diagnostic because of their limited lifetime

  10. On beam shaping of the field radiated by a line source coupled to finite or infinite photonic crystals.

    Science.gov (United States)

    Ceccuzzi, Silvio; Jandieri, Vakhtang; Baccarelli, Paolo; Ponti, Cristina; Schettini, Giuseppe

    2016-04-01

    Comparison of the beam-shaping effect of a field radiated by a line source, when an ideal infinite structure constituted by two photonic crystals and an actual finite one are considered, has been carried out by means of two different methods. The lattice sums technique combined with the generalized reflection matrix method is used to rigorously investigate the radiation from the infinite photonic crystals, whereas radiation from crystals composed of a finite number of rods along the layers is analyzed using the cylindrical-wave approach. A directive radiation is observed with the line source embedded in the structure. With an increased separation distance between the crystals, a significant edge diffraction appears that provides the main radiation mechanism in the finite layout. Suitable absorbers are implemented to reduce the above-mentioned diffraction and the reflections at the boundaries, thus obtaining good agreement between radiation patterns of a localized line source coupled to finite and infinite photonic crystals, when the number of periods of the finite structure is properly chosen.

  11. Aeroelastic simulation of multi-MW wind turbines using a free vortex model coupled to a geometrically exact beam model

    International Nuclear Information System (INIS)

    Saverin, Joseph; Peukert, Juliane; Marten, David; Pechlivanoglou, George; Paschereit, Christian Oliver; Greenblatt, David

    2016-01-01

    The current paper investigates the aeroelastic modelling of large, flexible multi- MW wind turbine blades. Most current performance prediction tools make use of the Blade Element Momentum (BEM) model, based upon a number of simplifying assumptions that hold only under steady conditions. This is why a lifting line free vortex wake (LLFVW) algorithm is used here to accurately resolve unsteady wind turbine aerodynamics. A coupling to the structural analysis tool BeamDyn, based on geometrically exact beam theory, allows for time-resolved aeroelastic simulations with highly deflected blades including bend-twist, coupling. Predictions of blade loading and deformation for rigid and flexible blades are analysed with reference to different aerodynamic and structural approaches. The emergency shutdown procedure is chosen as an examplary design load case causing large deflections to place emphasis on the influence of structural coupling and demonstrate the necessity of high fidelity structural models. (paper)

  12. Fiber-coupling efficiency of Gaussian-Schell model beams through an ocean to fiber optical communication link

    Science.gov (United States)

    Hu, Beibei; Shi, Haifeng; Zhang, Yixin

    2018-06-01

    We theoretically study the fiber-coupling efficiency of Gaussian-Schell model beams propagating through oceanic turbulence. The expression of the fiber-coupling efficiency is derived based on the spatial power spectrum of oceanic turbulence and the cross-spectral density function. Our work shows that the salinity fluctuation has a greater impact on the fiber-coupling efficiency than temperature fluctuation does. We can select longer λ in the "ocean window" and higher spatial coherence of light source to improve the fiber-coupling efficiency of the communication link. We also can achieve the maximum fiber-coupling efficiency by choosing design parameter according specific oceanic turbulence condition. Our results are able to help the design of optical communication link for oceanic turbulence to fiber sensor.

  13. The analysis of composite laminated beams using a 2D interpolating meshless technique

    Science.gov (United States)

    Sadek, S. H. M.; Belinha, J.; Parente, M. P. L.; Natal Jorge, R. M.; de Sá, J. M. A. César; Ferreira, A. J. M.

    2018-02-01

    Laminated composite materials are widely implemented in several engineering constructions. For its relative light weight, these materials are suitable for aerospace, military, marine, and automotive structural applications. To obtain safe and economical structures, the modelling analysis accuracy is highly relevant. Since meshless methods in the recent years achieved a remarkable progress in computational mechanics, the present work uses one of the most flexible and stable interpolation meshless technique available in the literature—the Radial Point Interpolation Method (RPIM). Here, a 2D approach is considered to numerically analyse composite laminated beams. Both the meshless formulation and the equilibrium equations ruling the studied physical phenomenon are presented with detail. Several benchmark beam examples are studied and the results are compared with exact solutions available in the literature and the results obtained from a commercial finite element software. The results show the efficiency and accuracy of the proposed numeric technique.

  14. The kick-out mass selection technique for ions stored in an Electrostatic Ion Beam Trap

    International Nuclear Information System (INIS)

    Toker, Y; Altstein, N; Aviv, O; Rappaport, M L; Heber, O; Schwalm, D; Strasser, D; Zajfman, D

    2009-01-01

    A simple mass selection technique which allows one to clean a keV ion beam of undesirable masses while stored in an Electrostatic Ion Beam Trap (EIBT) is described. The technique is based on the time-of-flight principle and takes advantage of the long storage times and self-bunching that are possible in this type of traps (self bunching being the effect that keeps ions of the same mass bunched in spite of their finite distributions of velocities and trajectories). As the oscillation period is proportional to the square root of the ion mass, bunches containing ions of different masses will separate in space with increasing storage time and can be kicked out by a pulsed deflector mounted inside the trap. A mass selector of this type has been implemented successfully in an EIBT connected to an Even-Lavie supersonic expansion source and is routinely used in ongoing cluster experiments.

  15. Active Vibration damping of Smart composite beams based on system identification technique

    Science.gov (United States)

    Bendine, Kouider; Satla, Zouaoui; Boukhoulda, Farouk Benallel; Nouari, Mohammed

    2018-03-01

    In the present paper, the active vibration control of a composite beam using piezoelectric actuator is investigated. The space state equation is determined using system identification technique based on the structure input output response provided by ANSYS APDL finite element package. The Linear Quadratic (LQG) control law is designed and integrated into ANSYS APDL to perform closed loop simulations. Numerical examples for different types of excitation loads are presented to test the efficiency and the accuracy of the proposed model.

  16. A Technique for Temperature and Ultimate Load Calculations of Thin Targets in a Pulsed Electron Beam

    DEFF Research Database (Denmark)

    Hansen, Jørgen-Walther; Lundsager, Per

    1979-01-01

    A technique is presented for the calculation of transient temperature distributions and ultimate load of rotationally symmetric thin membranes with uniform lateral load and exposed to a pulsed electron beam from a linear accelerator. Heat transfer by conduction is considered the only transfer...... mechanism. The ultimate load is calculated on the basis of large plastic strain analysis. Analysis of one aluminum and one titanium membrane is shown....

  17. Compositional analysis of YBaCuO superconducting films with ion beam analysis techniques

    International Nuclear Information System (INIS)

    Jones, S.; Timmers, H.; Ophel, T.R.; Elliman, R.G.

    1999-01-01

    High-T c YBa x Cu y O 7-δ superconducting films are being developed for applications such as superconducting quantum interference devices. The carrier concentration, critical current density J c and critical temperature T c of these films depend sensitively on the oxygen content . Stoichiometry, uniformity with depth, homogeneity across the sample and film thickness are also important quantities for their characterisation. It has been shown, for example, that the stoichiometry of the metallic elements affects the growth characteristics and surface morphology of the films. With the deposit ion techniques used, reproducibility of film properties is difficult. The characterisation of YBa x Cu y O 7-δ films with ion beam analysis techniques is complex. Whereas the three metallic elements can be detected with helium beams and Rutherford Backscattering (RBS), the oxygen signal is generally obscured by that from substrate elements. It can be better detected using resonant backscattering with 3.04MeV 4 He ions or nuclear reaction analysis. Elastic Recoil Detection (ERD) with high-energetic (1MeV/amu), heavy beams (Z > 120), enables all elements to be detected and separated in a single experiment. It is well established that ion bombardment induces vacancies in the oxygen sub-lattice, driving the material to change from crystalline to amorphous, the latter phase having a reduced oxygen content. In previous heavy ion ERD measurements of YBa x Cu yO z films with 200MeV 127 I beams, the opaque films became transparent in the beam spot area, indicative of the amorphous phase. The accuracy of the oxygen measurement is therefore questionable. Indeed, using Raman spectroscopy, distortions of the crystalline structure above a fluence of 5 x 10 11 ion/cm 2 and for higher doses some signatures of a reduction in oxygen content have been observed for such beams. It appears therefore that a correct determination of the oxygen content requires either a drastic reduction in fluence or a

  18. Nanosecond and femtosecond mass spectroscopic analysis of a molecular beam produced by the spray-jet technique

    International Nuclear Information System (INIS)

    Yamada, Toshiki; Shinohara, Hidenori; Kamikado, Toshiya; Okuno, Yoshishige; Suzuki, Hitoshi; Mashiko, Shinro; Yokoyama, Shiyoshi

    2008-01-01

    The spray-jet molecular beam apparatus enabled us to produce a molecular beam of non-volatile molecules under high vacuum from a sprayed mist of sample solutions. The apparatus has been used in spectroscopic studies and as a means of molecular beam deposition. We analyzed the molecular beam, consisting of non-volatile, solvent, and carrier-gas molecules, by using femtosecond- and nanosecond- laser mass spectroscopy. The information thus obtained provided insight into the molecular beam produced by the spray-jet technique

  19. Overview of Alternative Bunching and Current-shaping Techniques for Low-Energy Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Piot, Philippe [Northern Illinois U.

    2015-12-01

    Techniques to bunch or shape an electron beam at low energies (E <15 MeV) have important implications toward the realization of table-top radiation sources [1] or to the design of compact multi-user free-electron lasers[2]. This paper provides an overview of alternative methods recently developed including techniques such as wakefield-based bunching, space-charge-driven microbunching via wave-breaking [3], ab-initio shaping of the electron-emission process [4], and phase space exchangers. Practical applications of some of these methods to foreseen free-electron-laser configurations are also briefly discussed [5].

  20. A novel calorimetry technique for monitoring electron beam curing of polymer resins

    International Nuclear Information System (INIS)

    Chen, J.H.; Johnston, A.; Petrescue, L.; Hojjati, M.

    2006-01-01

    This paper describes the development of a calorimetry-based technique for monitoring of the curing of electron beam (EB) curable resins, including design of the calorimeter hardware and the development of an analytical model for calculating resin cure rates and radiation dose. Factors affecting the performance of the calorimeter were investigated. Experimental trials monitoring the curing of epoxy resin were conducted under single pass and multiple passes of EB irradiation. Results show that the developed calorimeter is a simple, inexpensive and reasonably accurate technique for monitoring the EB curing of cationic epoxies

  1. The Experimental Verification of Gaussian Beam Coupling for ECH Transmission Line at 400 GHz

    Directory of Open Access Journals (Sweden)

    Choe Mun Seok

    2017-01-01

    Full Text Available We design a quasi-optical transmission line system for a 400 GHz gyrotron beam. The 400GHz Gaussian beam is injected to a corrugated waveguide bounced from a quasi-optical mirror. From detailed 2D field patterns of the output beam emitted from the corrugated waveguide, we analyze the mode contents and the source of non-ideal beam expansion

  2. Geometric phase in a split-beam experiment measured with coupled neutron interference loops

    International Nuclear Information System (INIS)

    Hasegawa, Yuji; Zawisky, M.; Rauch, H.; Ioffe, A.

    1996-01-01

    A geometric phase factor is derived for a split-beam experiment as an example of cyclic evolutions. The geometric phase is given by one half of the solid angle independent of the spin of the beam. We observe this geometric phase with a two-loop neutron interferometer, where a reference beam can be added to the beam from one interference loop. All the experimental results show complete agreement with our theoretical treatment. (author)

  3. Position sensitive detection coupled to high-resolution time-of-flight mass spectrometry: Imaging for molecular beam deflection experiments

    International Nuclear Information System (INIS)

    Abd El Rahim, M.; Antoine, R.; Arnaud, L.; Barbaire, M.; Broyer, M.; Clavier, Ch.; Compagnon, I.; Dugourd, Ph.; Maurelli, J.; Rayane, D.

    2004-01-01

    We have developed and tested a high-resolution time-of-flight mass spectrometer coupled to a position sensitive detector for molecular beam deflection experiments. The major achievement of this new spectrometer is to provide a three-dimensional imaging (X and Y positions and time-of-flight) of the ion packet on the detector, with a high acquisition rate and a high resolution on both the mass and the position. The calibration of the experimental setup and its application to molecular beam deflection experiments are discussed

  4. 14th International Workshop on Slow Positron Beam Techniques and Applications

    International Nuclear Information System (INIS)

    2017-01-01

    These proceedings arose from the 14th International Workshop on Slow Positron Beam Techniques (SLOPOS14), which was held at Kunibiki Messe, Matsue, Shimane prefecture, Japan, from the 22nd—27th May 2016. Meetings in the SLOPOS series are held every three years. The SLOPOS workshop series has traditionally been devoted to investigations on the production of positron and positronium beams, their fundamental physics and chemistry, and their applications to materials such as metals, semiconductors and soft matter. During the workshop numerous applications using positron and positronium beams were also presented, clearly demonstrating the usefulness of such beams to the determination of surface structure, defect characterization as well as to fundamental scientific studies. For SLOPOS14 the main subjects of the workshop included the following: • Positron transport and beam technology • Pulsed positron beams and positron traps • Defect profiling in bulk and layered structures • Nano structures, porous materials and thin films • Surface and interface analysis • Positronium formation, emission and beams • Positron and positronium interactions with atoms and molecules • Many positrons and anti-hydrogen • Improvement of experimental techniques 106 delegates from 14 countries participated in the SLOPOS14, including 31 student delegates, which was a most encouraging sign for the future. The scientific program comprised 5 plenary talks, 22 invited talks, 32 contributed talks and 46 posters presented during two poster sessions. Student prizes were awarded for the best presented scientific contributions by 4 students from University of College London, Universität der Bundeswehr München and The University of Tokyo. On a sad note, delegates paid tribute to the contributions of our recently deceased colleagues, Prof. A. Seeger, Prof. R.N. West, Prof. T.C. Griffith, and Prof. Z. Tang. Memorial talks were given and a one minute silence was observed before the

  5. In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Caitlin; Bufford, Daniel; Muntifering, Brittany; Senor, David; Steckbeck, Mackenzie; Davis, Justin; Doyle, Barney; Buller, Daniel; Hattar, Khalid

    2017-09-29

    Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2.

  6. In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

    Directory of Open Access Journals (Sweden)

    Caitlin Anne Taylor

    2017-09-01

    Full Text Available Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM. This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs: zirconium alloys and LiAlO2.

  7. Investigate the electrical and thermal properties of the low temperature resistant silver nanowire fabricated by two-beam laser technique

    Science.gov (United States)

    He, Gui-Cang; Dong, Xian-Zi; Liu, Jie; Lu, Heng; Zhao, Zhen-Sheng

    2018-05-01

    A two-beam laser fabrication technique is introduced to fabricate the single silver nanowire (AgNW) on polyethylene terephthalate (PET) substrate. The resistivity of the AgNW is (1.31 ± 0.05) × 10-7 Ω·m, which is about 8 times of the bulk silver resistivity (1.65 × 10-8 Ω·m). The AgNW electrical resistance is measured in temperature range of 10-300 K and fitted with the Bloch-Grüneisen formula. The fitting results show that the residue resistance is 153 Ω, the Debye temperature is 210 K and the electron-phonon coupling constant is (5.72 ± 0.24) × 10-8 Ω·m. Due to the surface scattering, the Debye temperature and the electron-phonon coupling constant are lower than those of bulk silver, and the residue resistance is bigger than that of bulk silver. Thermal conductivity of the single AgNW is calculated in the corresponding temperature range, which is the biggest at the temperature approaching the Debye temperature. The AgNW on PET substrate is the low temperature resistance material and is able to be operated stably at such a low temperature of 10 K.

  8. Remarks on the derivation of the governing equations for the dynamics of a nonlinear beam to a non ideal shaft coupling

    Energy Technology Data Exchange (ETDEWEB)

    Fenili, André; Lopes Rebello da Fonseca Brasil, Reyolando Manoel [Universidade Federal do ABC (UFABC), Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas (CECS) / Aerospace Engineering Santo André, São Paulo (Brazil); Balthazar, José M., E-mail: jmbaltha@gmail.com [Universidade Federal do ABC (UFABC), Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas (CECS) / Aerospace Engineering Santo André, São Paulo, Brazil and Universidade Estadual Paulista, Faculdade de Engenharia Mec and #x00E (Brazil); Francisco, Cayo Prado Fernandes [Universidade Federal do ABC (UFABC), Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas (CECS) / Aerospace Engineering Santo André, São Paulo, Brazil and Instituto de Aeronáutica e Espaço, Departamento de (Brazil)

    2014-12-10

    We derive nonlinear governing equations without assuming that the beam is inextensible. The derivation couples the equations that govern a weak electric motor, which is used to rotate the base of the beam, to those that govern the motion of the beam. The system is considered non-ideal in the sense that the response of the motor to an applied voltage and the motion of the beam must be obtained interactively. The moment that the motor exerts on the base of the beam cannot be determined without solving for the motion of the beam.

  9. Remarks on the derivation of the governing equations for the dynamics of a nonlinear beam to a non ideal shaft coupling

    International Nuclear Information System (INIS)

    Fenili, André; Lopes Rebello da Fonseca Brasil, Reyolando Manoel; Balthazar, José M.; Francisco, Cayo Prado Fernandes

    2014-01-01

    We derive nonlinear governing equations without assuming that the beam is inextensible. The derivation couples the equations that govern a weak electric motor, which is used to rotate the base of the beam, to those that govern the motion of the beam. The system is considered non-ideal in the sense that the response of the motor to an applied voltage and the motion of the beam must be obtained interactively. The moment that the motor exerts on the base of the beam cannot be determined without solving for the motion of the beam

  10. Authenticity study of Phyllanthus species by NMR and FT-IR techniques coupled with chemometric methods

    International Nuclear Information System (INIS)

    Santos, Maiara S.; Pereira-Filho, Edenir R.; Ferreira, Antonio G.; Boffo, Elisangela F.; Figueira, Glyn M.

    2012-01-01

    The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as 'quebra-pedras' in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, 1 H HR-MAS NMR and 1 H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques. (author)

  11. Authenticity study of Phyllanthus species by NMR and FT-IR Techniques coupled with chemometric methods

    Directory of Open Access Journals (Sweden)

    Maiara S. Santos

    2012-01-01

    Full Text Available The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as "quebra-pedras" in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, ¹H HR-MAS NMR and ¹H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques.

  12. Authenticity study of Phyllanthus species by NMR and FT-IR techniques coupled with chemometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maiara S.; Pereira-Filho, Edenir R.; Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica; Boffo, Elisangela F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Figueira, Glyn M., E-mail: maiarassantos@yahoo.com.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro Pluridisciplinar de Pesquisas Quimicas, Biologicas e Agricolas

    2012-07-01

    The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as 'quebra-pedras' in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, {sup 1}H HR-MAS NMR and {sup 1}H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques. (author)

  13. Authenticity study of Phyllanthus species by NMR and FT-IR techniques coupled with chemometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maiara S.; Pereira-Filho, Edenir R.; Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica; Boffo, Elisangela F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Figueira, Glyn M., E-mail: maiarassantos@yahoo.com.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro Pluridisciplinar de Pesquisas Quimicas, Biologicas e Agricolas

    2012-07-01

    The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as 'quebra-pedras' in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, {sup 1}H HR-MAS NMR and {sup 1}H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques. (author)

  14. A Computational Study on the Magnetic Resonance Coupling Technique for Wireless Power Transfer

    Directory of Open Access Journals (Sweden)

    Zakaria N.A.

    2017-01-01

    Full Text Available Non-radiative wireless power transfer (WPT system using magnetic resonance coupling (MRC technique has recently been a topic of discussion among researchers. This technique discussed more scenarios in mid-range field of wireless power transmission reflected to the distance and efficiency. The WPT system efficiency varies when the coupling distance between two coils involved changes. This could lead to a decisive issue of high efficient power transfer. This paper presents case studies on the relationship of operating range with the efficiency of the MRC technique. Demonstrative WPT system operates at two different frequencies are projected in order to verify performance. The resonance frequencies used are less than 100MHz within range of 10cm to 20cm.

  15. Studies on post weld heat treatment of dissimilar aluminum alloys by laser beam welding technique

    Science.gov (United States)

    Srinivas, B.; Krishna, N. Murali; Cheepu, Muralimohan; Sivaprasad, K.; Muthupandi, V.

    2018-03-01

    The present study mainly focuses on post weld heat treatment (PWHT) of AA5083 and AA6061 alloys by joining these using laser beam welding at three different laser power and two different beam spot sizes and three different welding speeds. Effects of these parameters on microstructural and mechanical properties like hardness, tensile strength were studied at PWHT condition and significant changes had been observed. The PWHT used was artificial aging technique. The microstructural observations revealed that there was a appreciable changes were taken place in the grain size. The microhardness observations proven that the change in the hardness profile in AA6061 was appreciable than in the AA5083. The tensile strength of 246 MPa was recorded as highest. The fractured surfaces observed are predominantly ductile in nature.

  16. Application of object oriented techniques in the TRIUMF beam line 2C control system

    International Nuclear Information System (INIS)

    Wilkinson, N.A.; Ludgate, G.A.

    1992-07-01

    The KAON Factory central control system study employed a uniform approach to requirements analysis, architectural design and programming based on well established object oriented principles. These principles were applied to the successful analysis, design and implementation of the control system for the TRIUMF Beam Line 2C Solid Target Facility. The specification for this control system was created in collaboration with Beam Line 2C equipment management experts and, once the analysis models were validated, an approach was developed for the direct translation of these models into C code. A commercial real time database was central to this translation, as inter-object data and control flows are implemented by channels in the database. This paper focuses on the experience gained in the use of object oriented techniques during the complete analysis-design-implementation cycle of a working control system and on the utility of implementing such a system using a commercial real time database and graphical interface. (author)

  17. The comparison of Co-60 and 4MV photons matching dosimetry during half-beam technique

    International Nuclear Information System (INIS)

    Cakir, Aydin; Bilge, Hatice; Dadasbilge, Alpar; Kuecuecuek, Halil; Okutan, Murat; Merdan Fayda, Emre

    2005-01-01

    In this phantom study, we tried to compare matching dosimetry differences between half-blocking of Co-60 and asymmetric collimation of the 4MV photons during craniospinal irradiation. The dose distributions are compared and discussed. Firstly, some gaps with different sizes are left between cranial and spinal field borders. Secondly, the fields are overlapped in the same sizes. We irradiate the films located in water-equivalent solid phantoms with Co-60 and 4MV photon beams. This study indicates that the field placement errors in +/- 1mm are acceptable for both Co-60 and 4MV photon energies during craniospinal irradiation with half-beam block technique. Within these limits the dose variations are specified in +/- 5%. However, the setup errors that are more than 1mm are unacceptable for both asymmetric collimation of 4MV photon and half-blocking of Co-60

  18. A new analysis technique to measure fusion excitation functions with large beam energy dispersions

    Science.gov (United States)

    Figuera, P.; Di Pietro, A.; Fisichella, M.; Lattuada, M.; Shotter, A. C.; Ruiz, C.; Zadro, M.

    2018-01-01

    Peculiar nuclear structures of two colliding nuclei such has clustering, neutron halo/skin or very low breakup thresholds can affect the reaction dynamics below the Coulomb barrier and this may also have astrophysical consequences. In order to have a better understanding of this topic, in the last decade, several experiments were performed. A typical experimental challenge of such studies is the need to measure excitation functions below the Coulomb barrier, having a strong energy dependence, with rather large beam energy dispersions inside the target. This may easily lead to ambiguities in associating the measured cross section with a proper beam energy. In this paper a discussion on this topic is reported and a new technique to deal with the above problem will be proposed.

  19. Gas Source Techniques for Molecular Beam Epitaxy of Highly Mismatched Ge Alloys

    Directory of Open Access Journals (Sweden)

    Chad A. Stephenson

    2016-12-01

    Full Text Available Ge and its alloys are attractive candidates for a laser compatible with silicon integrated circuits. Dilute germanium carbide (Ge1−xCx offers a particularly interesting prospect. By using a precursor gas with a Ge4C core, C can be preferentially incorporated in substitutional sites, suppressing interstitial and C cluster defects. We present a method of reproducible and upscalable gas synthesis of tetrakis(germylmethane, or (H3Ge4C, followed by the design of a hybrid gas/solid-source molecular beam epitaxy system and subsequent growth of defect-free Ge1−xCx by molecular beam epitaxy (MBE. Secondary ion mass spectroscopy, transmission electron microscopy and contactless electroreflectance confirm the presence of carbon with very high crystal quality resulting in a decrease in the direct bandgap energy. This technique has broad applicability to growth of highly mismatched alloys by MBE.

  20. Interlayer exchange coupling, crystalline and magnetic structure in Fe/CsCl-FeSi multilayers grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Dekoster, J.; Degroote, S.; Meersschaut, J.; Moons, R.; Vantomme, A. [K.U. Leuven, Instituut voor Kern- en Stralingsfysica (Belgium); Bottyan, L.; Deak, L.; Szilagyi, E.; Nagy, D.L. [KFKI Research Institute for Particle and Nuclear Physics (Hungary); Baron, A.Q.R. [European Synchrotron Radiation Facility (France); Langouche, G. [K.U. Leuven, Instituut voor Kern- en Stralingsfysica (Belgium)

    1999-09-15

    Crystalline and magnetic structure as well as the interlayer exchange coupling in MBE grown Fe/FeSi multilayers are investigated. From conversion electron Moessbauer spectroscopy and ion beam channeling measurements the spacer FeSi material is found to be stabilized in a crystalline metastable metallic FeSi phase with the CsCl structure. Strong non-oscillatory interlayer exchange coupling is identified with magnetometry and synchrotron Moessbauer reflectometry. From the fits of the time spectrum and the resonant {phi}-{phi} scans a model for the sublayer magnetization of the multilayer is deduced.

  1. Evaluation of Temporal Diagnostic Techniques for Two-Bunch Facet Beam

    Energy Technology Data Exchange (ETDEWEB)

    Litos, M.D.; Bionta, M.R.; Dolgashev, V.A.; England, R.J.; Fritz, D.; Gilevich, S.; Hering, Ph.; Hogan, M.J.; /SLAC

    2011-08-19

    Three temporal diagnostic techniques are considered for use in the FACET facility at SLAC, which will incorporate a unique two-bunch beam for plasma wakefield acceleration experiments. The results of these experiments will depend strongly on the the inter-bunch spacing as well as the longitudinal profiles of the two bunches. A reliable, singleshot, high resolution measurement of the beam's temporal profile is necessary to fully quantify the physical mechanisms underlying the beam driven plasma wakefield acceleration. In this study we show that a transverse deflecting cavity is the diagnostic which best meets our criteria. Based on our laboratory testing, numerical calculations, and simulations of the three single-shot temporal diagnostic devices, the X-band TCAV system is the best candidate for resolving FACET's two-bunch beam, with an estimated resolution of 7 {micro}m. Both the S-band TCAV system and the EO system could resolve the peak-to-peak separation of the two bunches in the FACET beam with estimated resolutions of 25 {micro}m and 30 {micro}m, respectively, but would be unable to resolve the temporal profiles of the individual bunches themselves. Because the TCAV signal is more easily interpreted and because the reliability of the EO system is less well known, however, the S-band TCAV system would be the next preferred option after the X-band TCAV system. The Fesca-200 streak camera, though simple, compact, and reliable, is unable to achieve a resolution that would be of use to FACET.

  2. Development of Plant Mutation Breeding Techniques and Mutants Using by Ion Beam

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Si Yong; Song, Hi Sup; Park, In Sook; Kim, Dong Sub; Lee, Hye Jeong

    2005-06-15

    In recent, Japanese scientists have revealed that high liner energy transfer (LET) heavy-ion beams have relative high biological effectiveness (RBE) and seem to be more effective for induced plant mutation than low LET radiation i.e., X-rays, gamma rays and electrons. This study was conducted to develop basic induced mutation techniques of ion-beam using the MC-50 cyclotron (50MeV) at the Korea Institute of Radiological and Medical Science. For the irradiation of ion-beam, not only dry seeds of Arabidopsis, tabacco, Zosiagrass, radish, rice and perilla were packed with thin plastic film to be a monolayer of seeds for homogenous irradiation, but also calli of Zosiagrass and Chrysanthemum were placed in the plastic petridish (diameter 5.5cm) with agar medium. They were irradiated with a proton beam of MC-50 cyclotron with various dose ranges of 10 to 5000Gy depend on plant materials and then measured germination rate and early growth of M1 plants. Arabidopsis, tabacco, and Zosiagrass showed little inhibition of germination and early growth at doses tested over than 1000 Gy. In particular, Arabidopsis showed less growth inhibition than 50 % even at dose of 5000Gy. On the other hand, radish, perilla and rice were not only sensitively inhibited at the lower doses, but also linearly decreased with accordance with the increasing irradiation dose. The lethal dose 50 (LD50) for two cultivars of perilla was estimated to be at approximately 25-30Gy. All M1 plants of rice did not growth over than 500Gy. These results indicate that the significant difference in sensitivity or in LD50 to irradiation of MC-50 proton beam was observed among plant species and materials.

  3. Metallographic techniques for evaluation of Thermal Barrier Coatings produced by Electron Beam Physical Vapor Deposition

    International Nuclear Information System (INIS)

    Kelly, Matthew; Singh, Jogender; Todd, Judith; Copley, Steven; Wolfe, Douglas

    2008-01-01

    Thermal Barrier Coatings (TBC) produced by Electron Beam Physical Vapor Deposition (EB-PVD) are primarily applied to critical hot section turbine components. EB-PVD TBC for turbine applications exhibit a complicated structure of porous ceramic columns separated by voids that offers mechanical compliance. Currently there are no standard evaluation methods for evaluating EB-PVD TBC structure quantitatively. This paper proposes a metallographic method for preparing samples and evaluating techniques to quantitatively measure structure. TBC samples were produced and evaluated with the proposed metallographic technique and digital image analysis for columnar grain size and relative intercolumnar porosity. Incorporation of the proposed evaluation technique will increase knowledge of the relation between processing parameters and material properties by incorporating a structural link. Application of this evaluation method will directly benefit areas of quality control, microstructural model development, and reduced development time for process scaling

  4. Characterization of the Teotihuacan mural painting: application of the external particle beam as non destructive technique

    International Nuclear Information System (INIS)

    Martinez, C.; Manzanilla, L.; Ruvalcaba, J.L.; Ontalba, M.A.

    2005-01-01

    The characterization of technical indicators contained in the painting mural should follow a minim methodology from their discovery in the archaeological excavations until their analysis in the laboratory, with the purpose of rescuing diagnostic elements that mark the stages of socio cultural development in the towns. With this spirit it was carried out the present study analyzing some fragments of the Teotihuacan mural painting. The analysis consisted on applying some of the analytical techniques with particle beams used for archaeometry like the Proton induced X-ray emission (PIXE) and the particle elastic backscattering (RBS), due to it is treated of complementary techniques, very sensitive, of multielemental character, but mainly because its are non destructive analytical techniques. (Author)

  5. Accuracy of image-guided radiotherapy of prostate cancer based on the BeamCath urethral catheter technique

    DEFF Research Database (Denmark)

    Poulsen, Per Rugaard; Fokdal, Lars; Petersen, Jørgen B.B.

    2007-01-01

    BACKGROUND AND PURPOSE: To examine the accuracy of the BeamCath urethral catheter technique for prostate localization during radiotherapy. MATERIALS AND METHODS: Sixty-four patients were CT scanned twice with the BeamCath catheter, and once without the catheter. The catheter contains radiopaque...

  6. A large capacity time division multiplexed (TDM) laser beam combining technique enabled by nanosecond speed KTN deflector

    Science.gov (United States)

    Yin, Stuart (Shizhuo); Chao, Ju-Hung; Zhu, Wenbin; Chen, Chang-Jiang; Campbell, Adrian; Henry, Michael; Dubinskiy, Mark; Hoffman, Robert C.

    2017-08-01

    In this paper, we present a novel large capacity (a 1000+ channel) time division multiplexing (TDM) laser beam combining technique by harnessing a state-of-the-art nanosecond speed potassium tantalate niobate (KTN) electro-optic (EO) beam deflector as the time division multiplexer. The major advantages of TDM approach are: (1) large multiplexing capability (over 1000 channels), (2) high spatial beam quality (the combined beam has the same spatial profile as the individual beam), (3) high spectral beam quality (the combined beam has the same spectral width as the individual beam, and (4) insensitive to the phase fluctuation of individual laser because of the nature of the incoherent beam combining. The quantitative analyses show that it is possible to achieve over one hundred kW average power, single aperture, single transverse mode solid state and/or fiber laser by pursuing this innovative beam combining method, which represents a major technical advance in the field of high energy lasers. Such kind of 100+ kW average power diffraction limited beam quality lasers can play an important role in a variety of applications such as laser directed energy weapons (DEW) and large-capacity high-speed laser manufacturing, including cutting, welding, and printing.

  7. New technique of skin embedded wire double-sided laser beam welding

    Science.gov (United States)

    Han, Bing; Tao, Wang; Chen, Yanbin

    2017-06-01

    In the aircraft industry, double-sided laser beam welding is an approved method for producing skin-stringer T-joints on aircraft fuselage panels. As for the welding of new generation aluminum-lithium alloys, however, this technique is limited because of high hot cracking susceptibility and strengthening elements' uneven distributions within weld. In the present study, a new technique of skin embedded wire double-sided laser beam welding (LBW) has been developed to fabricate T-joints consisting of 2.0 mm thick 2060-T8/2099-T83 aluminum-lithium alloys using eutectic alloy AA4047 filler wire. Necessary dimension parameters of the novel groove were reasonably designed for achieving crack-free welds. Comparisons were made between the new technique welded T-joint and conventional T-joint mainly on microstructure, hot crack, elements distribution features and mechanical properties within weld. Excellent crack-free microstructure, uniform distribution of silicon and superior tensile properties within weld were found in the new skin embedded wire double-sided LBW T-joints.

  8. Measurement of Gaussian laser beam radius using the knife-edge technique: improvement on data analysis

    International Nuclear Information System (INIS)

    Araujo, Marcos A. de; Silva, Rubens; Lima, Emerson de; Pereira, Daniel P.; Oliveira, Paulo C. de

    2009-01-01

    We revisited the well known Khosrofian and Garetz inversion algorithm [Appl. Opt.22, 3406-3410 (1983)APOPAI0003-6935] that was developed to analyze data obtained by the application of the traveling knife-edge technique. We have analyzed the approximated fitting function that was used for adjusting their experimental data and have found that it is not optimized to work with a full range of the experimentally-measured data. We have numerically calculated a new set of coefficients, which makes the approximated function suitable for a full experimental range, considerably improving the accuracy of the measurement of a radius of a focused Gaussian laser beam

  9. Poly(methyl methacrylate) Composites with Size-selected Silver Nanoparticles Fabricated Using Cluster Beam Technique

    DEFF Research Database (Denmark)

    Muhammad, Hanif; Juluri, Raghavendra R.; Chirumamilla, Manohar

    2016-01-01

    based on cluster beam technique allowing the formation of monocrystalline size-selected silver nanoparticles with a ±5–7% precision of diameter and controllable embedment into poly (methyl methacrylate). It is shown that the soft-landed silver clusters preserve almost spherical shape with a slight...... tendency to flattening upon impact. By controlling the polymer hardness (from viscous to soft state) prior the cluster deposition and annealing conditions after the deposition the degree of immersion of the nanoparticles into polymer can be tuned, thus, making it possible to create composites with either...

  10. Measurements of low density, high velocity flow by electron beam fluorescence technique

    International Nuclear Information System (INIS)

    Soga, Takeo; Takanishi, Masaya; Yasuhara, Michiru

    1981-01-01

    A low density chamber with an electron gun system was made for the measurements of low density, high velocity (high Mach number) flow. This apparatus is a continuous running facility. The number density and the rotational temperature in the underexpanding free jet of nitrogen were measured along the axis of the jet by the electron beam fluorescence technique. The measurements were carried out from the vicinity of the exit of the jet to far downstream of the first Mach disk. Rotational nonequilibrium phenomena were observed in the hypersonic flow field as well as in the shock wave (Mach disk). (author)

  11. Vibroacoustic Modeling of Mechanically Coupled Structures: Artificial Spring Technique Applied to Light and Heavy Mediums

    Directory of Open Access Journals (Sweden)

    L. Cheng

    1996-01-01

    Full Text Available This article deals with the modeling of vibrating structures immersed in both light and heavy fluids, and possible applications to noise control problems and industrial vessels containing fluids. A theoretical approach, using artificial spring systems to characterize the mechanical coupling between substructures, is extended to include fluid loading. A structure consisting of a plate-ended cylindrical shell and its enclosed acoustic cavity is analyzed. After a brief description of the proposed technique, a number of numerical results are presented. The analysis addresses the following specific issues: the coupling between the plate and the shell; the coupling between the structure and the enclosure; the possibilities and difficulties regarding internal soundproofing through modifications of the joint connections; and the effects of fluid loading on the vibration of the structure.

  12. Measurement techniques for low emittance tuning and beam dynamics at CESR

    Science.gov (United States)

    Billing, M. G.; Dobbins, J. A.; Forster, M. J.; Kreinick, D. L.; Meller, R. E.; Peterson, D. P.; Ramirez, G. A.; Rendina, M. C.; Rider, N. T.; Sagan, D. C.; Shanks, J.; Sikora, J. P.; Stedinger, M. G.; Strohman, C. R.; Williams, H. A.; Palmer, M. A.; Holtzapple, R. L.; Flanagan, J.

    2018-03-01

    After operating as a High Energy Physics electron-positron collider, the Cornell Electron-positron Storage Ring (CESR) has been converted to become a dedicated synchrotron light source for the Cornell High Energy Synchrotron Source (CHESS). Over the course of several years CESR was adapted for accelerator physics research as a test accelerator, capable of studying topics relevant to future damping rings, colliders and light sources. Initially some specific topics were targeted for accelerator physic research with the storage ring in this mode, labeled CesrTA. These topics included 1) tuning techniques to produce low emittance beams, 2) the study of electron cloud (EC) development in a storage ring and 3) intra-beam scattering effects. The complete conversion of CESR to CesrTA occurred over a several year period, described elsewhere [1–3]. A number of specific instruments were developed for CesrTA. Much of the pre-existing instrumentation was modified to accommodate the scope of these studies and these are described in a companion paper [4]. To complete this research, a number of procedures were developed or modified, often requiring coordinated measurements among different instruments [5]. This paper provides an overview of types of measurements employed for the study of beam dynamics during the operation of CesrTA.

  13. Development of small scale mechanical testing techniques on ion beam irradiated 304 SS

    International Nuclear Information System (INIS)

    Reichardt, A.; Abad, M.D.; Hosemann, P.; Lupinacci, A.; Kacher, J.; Minor, A.; Jiao, Z; Chou, P.

    2015-01-01

    Austenitic stainless steels are widely used for structural components in light water reactors, however uncertainty in their susceptibility to irradiation assisted stress corrosion cracking (IASCC) has made long term performance predictions difficult. In addition, the testing of reactor irradiated materials has proven challenging due to the long irradiation times required, limited sample availability, and unwanted activation. To address these problems, we apply recently developed techniques in nano-indentation and micro-compression testing to small volume samples of 10 dpa proton-beam irradiated 304 stainless steel. Cross sectional nano-indentation was performed on both proton beam irradiated and non-irradiated samples at temperatures ranging from 22 to 300 C. degrees to determine the effects of irradiation and operating temperature on hardening. Micro-compression tests using 2 μm x 2 μm x 5 μm focused-ion beam milled pillars were then performed in situ in an electron microscope to allow for a more accurate look at stress-strain behavior along with real-time observations of localized mechanical deformation. Large sudden slip events and significant increase in yield strength are observed in irradiated micro-compression samples at room temperature. Elevated temperature nano-indentation results reveal the possibility of thermally-activated changes in deformation mechanism for irradiated specimens. Since the deformation mechanism information provided by micro-compression testing can provide valuable information about IASCC susceptibility, future work will involve ex situ micro-compression tests at reactor operating temperature

  14. Searches for the Anomalous FCNC Top-Higgs Couplings with Polarized Electron Beam at the LHeC

    Directory of Open Access Journals (Sweden)

    XiaoJuan Wang

    2017-01-01

    Full Text Available We study the single top and Higgs associated production e-p→νet-→νehq-(h→bb- in the top-Higgs FCNC couplings at the LHeC with the electron beam energy of Ee=60 GeV and Ee=120 GeV and combination of a 7 TeV and 50 TeV proton beam. With the possibility of e-beam polarization (pe=0, ±0.6, we distinct the cut-based method and the multivariate analysis- (MVA- based method and compare with the current experimental and theoretical limits. It is shown that the branching ratio Br(t→uh can be probed to 0.113 (0.093%, 0.071 (0.057%, 0.030 (0.022%, and 0.024 (0.019% with the cut-based (MVA-based analysis at (Ep, Ee = (7 TeV, 60 GeV, (Ep, Ee = (7 TeV, 120 GeV, (Ep, Ee = (50 TeV, 60 GeV, and (Ep, Ee = (50 TeV, 120 GeV beam energy and 1σ level. With the possibility of e-beam polarization, the expected limits can be probed down to 0.090 (0.073%, 0.056 (0.045%, 0.024 (0.018%, and 0.019 (0.015%, respectively.

  15. Further studies on beam breakup growth reduction by cavity cross-couplings in recirculating accelerators: Effects of long pulse length and multiturn recirculation

    International Nuclear Information System (INIS)

    Colombant, D.; Lau, Y.Y.

    1992-01-01

    Cavity cross-coupling was recently found to reduce beam breakup (BBU) growth in a recirculating accelerator known as the Spiral Line Induction Accelerator (SLIA). Here, we extend the analysis in two prespects: ong beam pulse lengths and a SLIA upgrade geometry which accelerates a 10 kA, 35 ns beam to 25 MeV via a 70 cavity, 7 turn recirculation. We found that when the beam pulse length τ exceeds the beam's transit time τ' between cross-coupled cavities, BBU growth may be worsened as a result of the cross-coupling among cavities. This situation is not unlike other long pulse recirculating accelerators where beam recirculation leads to beam breakup of a regenerative type. Thus, the advantage of BBU reduction by cavity cross-coupling is restricted primarily to beams with τ<τ', a condition envisioned for all SLIA geometries. For the 70 gap, 7 turn SLIA upgrade, we found that cavity cross-coupling may reduce BBU growth up to factors of a thousand when the quality factor Q of the deflecting modes are relatively high (like 100). In these high Q cases, the amount of growth reduction depends on the arrangement and sequence of beam recirculation. For Q < or approx. 20, BBU growth reduction by factors of hundreds is observed, but this reduction is insensitive to the sequence of beam recirculation. The above conclusions were based on simple models of cavity coupling that have been used in conventional microwave literature. Not addressed is the detail design consideration that leads to the desired degree of cavity coupling. (orig.)

  16. Design and experimental investigation of a magnetically coupled vibration energy harvester using two inverted piezoelectric cantilever beams for rotational motion

    International Nuclear Information System (INIS)

    Zou, Hong-Xiang; Zhang, Wen-ming; Li, Wen-Bo; Wei, Ke-Xiang; Gao, Qiu-Hua; Peng, Zhi-Ke; Meng, Guang

    2017-01-01

    Highlights: • A magnetically coupled two-degree-of-freedom harvester for rotation is proposed. • The electromechanical coupling model is developed and validated experimentally. • The harvester can generate high voltage at low rotating speeds. • The harvester can harvest vibration energy in multiple frequency bands. - Abstract: Energy can be harvested from rotational motion for powering wireless autonomous electronic devices. The paper presents a magnetically coupled two-degree-of-freedom vibration energy harvester for rotary motion applications. The design consists of two inverted piezoelectric cantilever beams whose free ends point to the rotating shaft. The centrifugal force of the inverted cantilever beam is beneficial to producing large amplitude in a low speed range. The electromechanical coupling dynamical model is developed by the energy method from Hamilton’s principle and validated experimentally. The experimental results indicate that the presented harvester is suitable for low speed rotation and can harvest vibration energy in multiple frequency bands. The first and second resonant behaviors of voltage can be obtained at 420 r/min and 550 r/min, and the average output powers are 564 μW and 535.3 μW, respectively.

  17. A technique for measuring an electron beam close-quote s longitudinal phase space with sub-picosecond resolution

    International Nuclear Information System (INIS)

    Crosson, E.R.; Berryman, K.W.; Richman, B.A.; Smith, T.I.; Swent, R.L.

    1996-01-01

    We have developed a technique for measuring the longitudinal phase space distribution of the Stanford Superconducting Accelerator close-quote s (SCA) electron beam which involves applying tomographic techniques to energy spectra taken as a function of the relative phase between the beam and the accelerating field, and optionally, as a function of the strength of a variable dispersion section in the system. The temporal profile of the beam obtained by projecting the inferred distribution onto the time axis is compared with that obtained from interferometric transition radiation measurements. copyright 1996 American Institute of Physics

  18. Current medical research with the application of coupled techniques with mass spectrometry

    OpenAIRE

    Ka?u?na-Czapli?ska, Joanna

    2011-01-01

    Summary The most effective methods of analysis of organic compounds in biological fluids are coupled chromatographic techniques. Capillary gas chromatography/mass spectrometry (GC-MS) allows the most efficient separation, identification and quantification of volatile metabolites in biological fluids. Liquid chromatography-mass spectrometry (LC-MS) is especially suitable for the analysis of non-volatile and/or thermally unstable compounds. A major drawback of liquid chromatography-mass spectro...

  19. Neutron therapy coupling brachytherapy and boron neutron capture therapy (BNCT) techniques

    International Nuclear Information System (INIS)

    Chaves, Iara Ferreira.

    1994-12-01

    In the present dissertation, neutron radiation techniques applied into organs of the human body are investigated as oncologic radiation therapy. The proposal treatment consists on connecting two distinct techniques: Boron Neutron Capture Therapy (BNCT) and irradiation by discrete sources of neutrons, through the brachytherapy conception. Biological and radio-dosimetrical aspects of the two techniques are considered. Nuclear aspects are discussed, presenting the nuclear reactions occurred in tumoral region, and describing the forms of evaluating the dose curves. Methods for estimating radiation transmission are reviewed through the solution of the neutron transport equation, Monte Carlo methodology, and simplified analytical calculation based on diffusion equation and numerical integration. The last is computational developed and presented as a quickly way to neutron transport evaluation in homogeneous medium. The computational evaluation of the doses for distinct hypothetical situations is presented, applying the coupled techniques BNTC and brachytherapy as an possible oncologic treatment. (author). 78 refs., 61 figs., 21 tabs

  20. Laser cooled ion beams and strongly coupled plasmas for precision experiments

    International Nuclear Information System (INIS)

    Bussmann, Michael

    2008-01-01

    This cumulative thesis summarizes experimental and theoretical results on cooling of ion beams using single-frequency, single-mode tabletop laser systems. It consists of two parts. One deals with experiments on laser-cooling of ion beams at relativistic energies, the other with simulations of stopping and sympathetic cooling of ions for precision in-trap experiments. In the first part, experimental results are presented on laser-cooling of relativistic C 3+ ion beams at a beam energy of 122 MeV/u, performed at the Experimental Storage Ring (ESR) at GSI. The main results presented in this thesis include the first attainment of longitudinally space-charge dominated relativistic ion beams using pure laser-cooling. The second part lists theoretical results on stopping and sympathetic cooling of ions in a laser-cooled one-component plasma of singly charged 24 Mg ions, which are confined in a three-dimensional harmonic trap potential. (orig.)

  1. Review of online coupling of sample preparation techniques with liquid chromatography.

    Science.gov (United States)

    Pan, Jialiang; Zhang, Chengjiang; Zhang, Zhuomin; Li, Gongke

    2014-03-07

    Sample preparation is still considered as the bottleneck of the whole analytical procedure, and efforts has been conducted towards the automation, improvement of sensitivity and accuracy, and low comsuption of organic solvents. Development of online sample preparation techniques (SP) coupled with liquid chromatography (LC) is a promising way to achieve these goals, which has attracted great attention. This article reviews the recent advances on the online SP-LC techniques. Various online SP techniques have been described and summarized, including solid-phase-based extraction, liquid-phase-based extraction assisted with membrane, microwave assisted extraction, ultrasonic assisted extraction, accelerated solvent extraction and supercritical fluids extraction. Specially, the coupling approaches of online SP-LC systems and the corresponding interfaces have been discussed and reviewed in detail, such as online injector, autosampler combined with transport unit, desorption chamber and column switching. Typical applications of the online SP-LC techniques have been summarized. Then the problems and expected trends in this field are attempted to be discussed and proposed in order to encourage the further development of online SP-LC techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. A coupled piezoelectric–electromagnetic energy harvesting technique for achieving increased power output through damping matching

    International Nuclear Information System (INIS)

    Challa, Vinod R; Prasad, M G; Fisher, Frank T

    2009-01-01

    Vibration energy harvesting is being pursued as a means to power wireless sensors and ultra-low power autonomous devices. From a design standpoint, matching the electrical damping induced by the energy harvesting mechanism to the mechanical damping in the system is necessary for maximum efficiency. In this work two independent energy harvesting techniques are coupled to provide higher electrical damping within the system. Here the coupled energy harvesting device consists of a primary piezoelectric energy harvesting device to which an electromagnetic component is added to better match the total electrical damping to the mechanical damping in the system. The first coupled device has a resonance frequency of 21.6 Hz and generates a peak power output of ∼332 µW, compared to 257 and 244 µW obtained from the optimized, stand-alone piezoelectric and electromagnetic energy harvesting devices, respectively, resulting in a 30% increase in power output. A theoretical model has been developed which closely agrees with the experimental results. A second coupled device, which utilizes the d 33 piezoelectric mode, shows a 65% increase in power output in comparison to the corresponding stand-alone, single harvesting mode devices. This work illustrates the design considerations and limitations that one must consider to enhance device performance through the coupling of multiple harvesting mechanisms within a single energy harvesting device

  3. New imaging technique based on diffraction of a focused x-ray beam

    Energy Technology Data Exchange (ETDEWEB)

    Kazimirov, A [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); Kohn, V G [Russian Research Center ' Kurchatov Institute, 123182 Moscow (Russian Federation); Cai, Z-H [Advanced Photon Source, 9700 S. Cass Avenue, Argonne, IL 60439 (United States)], E-mail: ayk7@cornell.edu

    2009-01-07

    We present first experimental results from a new diffraction depth-sensitive imaging technique. It is based on the diffraction of a focused x-ray beam from a crystalline sample and recording the intensity pattern on a high-resolution CCD detector positioned at a focal plane. Structural non-uniformity inside the sample results in a region of enhanced intensity in the diffraction pattern. The technique was applied to study silicon-on-insulator thin layers of various thicknesses which revealed a complex strain profile within the layers. A circular Fresnel zone plate was used as a focusing optic. Incoherent diffuse scattering spreads out of the diffraction plane and results in intensity recorded outside of the focal spot providing a new approach to separately register x-rays scattered coherently and incoherently from the sample. (fast track communication)

  4. Future strategy and puzzles of heavy ion beam mediated technique in genetic improvement of biological bodies

    International Nuclear Information System (INIS)

    Huang Qunce

    2007-01-01

    The 7 research puzzles in the genetic improvement of biological bodies made by ion beam mediated technique, are worth noticed. The technical ideas, including one mediated technique in physics, 2 significant subjects, 3 effective changes, the mediated evidences of 4 aspects and 5 biological characteristics, were particularly put forward according to the existing states in the field. The 2 significant subjects consist of the mechanics of the allogenetic materials entering into the acceptor and they being to be recombined. The 3 effective changes include from studying morphology to genetic laws, from researching M1 generation to the next generations, from determining the single character to the synthetic traits. The mediated evidences of 4 aspects come from morphology, physiology and biochemistry, molecule biology. The 5 biological characteristics are mainly reproduction, development, photosynthesis, bad condition-resistant and quality. (authors)

  5. Initial experience of using an active beam delivery technique at PSI

    International Nuclear Information System (INIS)

    Pedroni, E.; Boehringer, T.; Coray, A.; Egger, E.; Grossmann, M.; Lin Shixiong; Lomax, A.; Goitein, G.; Roser, W.; Schaffner, B.

    1999-01-01

    At PSI a new proton therapy facility has been assembled and commissioned. The major features of the facility are the spot scanning technique and the very compact gantry. The operation of the facility was started in 1997 and the feasibility of the spot scanning technique has been demonstrated in practice with patient treatments. In this report we discuss the usual initial difficulties encountered in the commissioning of a new technology, the very positive preliminary experience with the system and the optimistic expectations for the future. The long range goal of this project is to parallel the recent developments regarding inverse planning for photons with a similar advanced technology optimized for a proton beam. (orig.)

  6. A technique for transferring a patient's smile line to a cone beam computed tomography (CBCT) image.

    Science.gov (United States)

    Bidra, Avinash S

    2014-08-01

    Fixed implant-supported prosthodontic treatment for patients requiring a gingival prosthesis often demands that bone and implant levels be apical to the patient's maximum smile line. This is to avoid the display of the prosthesis-tissue junction (the junction between the gingival prosthesis and natural soft tissues) and prevent esthetic failures. Recording a patient's lip position during maximum smile is invaluable for the treatment planning process. This article presents a simple technique for clinically recording and transferring the patient's maximum smile line to cone beam computed tomography (CBCT) images for analysis. The technique can help clinicians accurately determine the need for and amount of bone reduction required with respect to the maximum smile line and place implants in optimal positions. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  7. Analysis and modification of blue sapphires from Rwanda by ion beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bootkul, D., E-mail: mo_duangkhae@hotmail.com [Department of General Science - Gems & Jewelry, Faculty of Science, Srinakharinwirot University, Bangkok 10110 (Thailand); Chaiwai, C.; Tippawan, U. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wanthanachaisaeng, B. [Gems Enhancement Research Unit, Faculty of Gems, Burapha University, Chanthaburi Campus, Chanthaburi 22170 (Thailand); Intarasiri, S., E-mail: saweat@gmail.com [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-12-15

    Highlights: • Ion beam analysis is an effective method for detecting trace elements. • Ion beam treatment is able to improve optical and color appearances of the blue sapphire from Rwanda. • These alternative methods can be extended to jewelry industry for large scale application. - Abstract: Blue sapphire is categorised in a corundum (Al{sub 2}O{sub 3}) group. The gems of this group are always amazed by their beauties and thus having high value. In this study, blue sapphires from Rwanda, recently came to Thai gemstone industry, are chosen for investigations. On one hand, we have applied Particle Induced X-ray Emission (PIXE), which is a highly sensitive and precise analytical technique that can be used to identify and quantify trace elements, for chemical analysis of the sapphires. Here we have found that the major element of blue sapphires from Rwanda is Al with trace elements such as Fe, Ti, Cr, Ga and Mg as are commonly found in normal blue sapphire. On the other hand, we have applied low and medium ion implantations for color improvement of the sapphire. It seems that a high amount of energy transferring during cascade collisions have altered the gems properties. We have clearly seen that the blue color of the sapphires have been intensified after nitrogen ion bombardment. In addition, the gems were also having more transparent and luster. The UV–Vis–NIR measurement detected the modification of their absorption properties, implying of the blue color increasing. Here the mechanism of these modifications is postulated and reported. In any point of view, the bombardment by using nitrogen ion beam is a promising technique for quality improvement of the blue sapphire from Rwanda.

  8. Analysis and modification of blue sapphires from Rwanda by ion beam techniques

    International Nuclear Information System (INIS)

    Bootkul, D.; Chaiwai, C.; Tippawan, U.; Wanthanachaisaeng, B.; Intarasiri, S.

    2015-01-01

    Highlights: • Ion beam analysis is an effective method for detecting trace elements. • Ion beam treatment is able to improve optical and color appearances of the blue sapphire from Rwanda. • These alternative methods can be extended to jewelry industry for large scale application. - Abstract: Blue sapphire is categorised in a corundum (Al_2O_3) group. The gems of this group are always amazed by their beauties and thus having high value. In this study, blue sapphires from Rwanda, recently came to Thai gemstone industry, are chosen for investigations. On one hand, we have applied Particle Induced X-ray Emission (PIXE), which is a highly sensitive and precise analytical technique that can be used to identify and quantify trace elements, for chemical analysis of the sapphires. Here we have found that the major element of blue sapphires from Rwanda is Al with trace elements such as Fe, Ti, Cr, Ga and Mg as are commonly found in normal blue sapphire. On the other hand, we have applied low and medium ion implantations for color improvement of the sapphire. It seems that a high amount of energy transferring during cascade collisions have altered the gems properties. We have clearly seen that the blue color of the sapphires have been intensified after nitrogen ion bombardment. In addition, the gems were also having more transparent and luster. The UV–Vis–NIR measurement detected the modification of their absorption properties, implying of the blue color increasing. Here the mechanism of these modifications is postulated and reported. In any point of view, the bombardment by using nitrogen ion beam is a promising technique for quality improvement of the blue sapphire from Rwanda.

  9. Novel technique for injecting and extracting beams in a circular hadron accelerator without using septum magnets

    Directory of Open Access Journals (Sweden)

    Andrea Franchi

    2015-07-01

    Full Text Available With a few exceptions, all on-axis injection and extraction schemes implemented in circular particle accelerators, synchrotrons, and storage rings, make use of magnetic and electrostatic septa with systems of slow-pulsing dipoles acting on tens of thousands of turns and fast-pulsing dipoles on just a few. The dipoles create a closed orbit deformation around the septa, usually referred to as an orbit bump. A new approach is presented which obviates the need for the septum deflectors. Fast-pulsing elements are still required, but their strength can be minimized by choosing appropriate local accelerator optics. This technique should increase the beam clearance and reduce the usually high radiation levels found around the septa and also reduce the machine impedance introduced by the fast-pulsing dipoles. The basis of the technique is the creation of stable islands around stable fixed points in horizontal phase space. The trajectories of these islands may then be adjusted to match the position and angle of the incoming or outgoing beam.

  10. Recoil separators for radiative capture using radioactive ion beams. Recent advances and detection techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Chris [TRIUMF, Vancouver, BC (Canada); Greife, Uwe; Hager, Ulrike [Colorado School of Mines, Golden, CO (United States)

    2014-06-15

    Radiative capture reactions involving the fusion of hydrogen or helium are ubiquitous in the stellar history of the universe, and are some of the most important reactions in the processes that govern nucleosynthesis and energy generation in both static and explosive scenarios. However, radiative capture reactions pose some of the most difficult experimental challenges due to extremely small cross sections. With the advent of recoil separators and techniques in inverse kinematics, it is now possible to measure radiative capture reactions on very short-lived radioactive nuclei, and in the presence of high experimental backgrounds. In this paper we review the experimental needs for making measurements of astrophysical importance on radiative capture reactions. We also review some of the important historical advances in the field of recoil separators as well as describe current techniques and performance milestones, including descriptions of some of the separators most recently working at radioactive ion beam facilities, such as DRAGON at TRIUMF and the DRS at the Holifield Radioactive Ion Beam Facility. We will also summarize some of the scientific highlight measurements at the RIB facilities. (orig.)

  11. Modeling and control of sound radiation by simply supported and cantilever beam coupled with smart material

    Directory of Open Access Journals (Sweden)

    Vitaly Makarenko

    2007-03-01

    Full Text Available  In this paper forced vibration of the beam due to bonded piezoelectric patch is considered. When an external excitation is applied to the beam, it starts to vibrate, and the resulting acoustic response is predicted from the analytical model, which is based on Bernoulli-Euler theory of beam vibration. Analytical research of the sound radiation by a finite elastic beam is done for criteria based on minimal total sound power level. Helmholtz equation and inhomogeneous differential equation for beam transverse motion defines the solution to this problem. Such solutions were found for boundary conditions of simply supported and cantilever beams. In order to solve the task two analytical methods were used for simply supported beam. The solutions received by Fourier transform and Green functions approach give the very similar results, thus, proving methods reliability. At the case studies the exerted voltage, phase, location and piezoelectric actuator length are varied in order to establish their influence on noise attenuation.

  12. Using the in situ lift-out technique to prepare TEM specimens on a single-beam FIB instrument

    International Nuclear Information System (INIS)

    Lekstrom, M; McLachlan, M A; Husain, S; McComb, D W; Shollock, B A

    2008-01-01

    Transmission electron microscope (TEM) specimens are today routinely prepared using focussed ion beam (FIB) instruments. Specifically, the lift-out method has become an increasingly popular technique and involves removing thin cross-sections from site-specific locations and transferring them to a TEM grid. This lift-out process can either be performed ex situ or in situ. The latter is mainly carried out on combined dual-beam FIB and scanning electron microscope (SEM) systems whereas conventional single-beam instruments often are limited to the traditional ex situ method. It is nevertheless desirable to enhance the capabilities of existing single-beam instruments to allow for in situ lift-out preparation to be performed since this technique offers a number of advantages over the older ex situ method. A single-beam FIB instrument was therefore modified to incorporate an in situ micromanipulator fitted with a tungsten needle, which can be attached to a cut-out FIB section using ion beam induced platinum deposition. This article addresses the issues of using an ion beam to monitor the in situ manipulation process as well as approaches that can be used to create stronger platinum welds between two objects, and finally, views on how to limit the extent of ion beam damage to the specimen surface.

  13. Fundamental studies of the plasma extraction and ion beam formation processes in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Niu, Hongsen.

    1995-01-01

    The fundamental and practical aspects are described for extracting ions from atmospheric pressure plasma sources into an analytical mass spectrometer. Methodologies and basic concepts of inductively coupled plasma mass spectrometry (ICP-MS) are emphasized in the discussion, including ion source, sampling interface, supersonic expansion, slumming process, ion optics and beam focusing, and vacuum considerations. Some new developments and innovative designs are introduced. The plasma extraction process in ICP-MS was investigated by Langmuir measurements in the region between the skimmer and first ion lens. Electron temperature (T e ) is in the range 2000--11000 K and changes with probe position inside an aerosol gas flow. Electron density (n e ) is in the range 10 8 --10 10 -cm at the skimmer tip and drops abruptly to 10 6 --10 8 cm -3 near the skimmer tip and drops abruptly to 10 6 --10 8 cm -3 downstream further behind the skimmer. Electron density in the beam leaving the skimmer also depends on water loading and on the presence and mass of matrix elements. Axially resolved distributions of electron number-density and electron temperature were obtained to characterize the ion beam at a variety of plasma operating conditions. The electron density dropped by a factor of 101 along the centerline between the sampler and skimmer cones in the first stage and continued to drop by factors of 10 4 --10 5 downstream of skimmer to the entrance of ion lens. The electron density in the beam expansion behind sampler cone exhibited a 1/z 2 intensity fall-off (z is the axial position). An second beam expansion originated from the skimmer entrance, and the beam flow underwent with another 1/z 2 fall-off behind the skimmer. Skimmer interactions play an important role in plasma extraction in the ICP-MS instrument

  14. MODELLING THE DELAMINATION FAILURE ALONG THE CFRP-CFST BEAM INTERACTION SURFACE USING DIFFERENT FINITE ELEMENT TECHNIQUES

    Directory of Open Access Journals (Sweden)

    AHMED W. AL-ZAND

    2017-01-01

    Full Text Available Nonlinear finite element (FE models are prepared to investigate the behaviour of concrete-filled steel tube (CFST beams strengthened by carbon fibre reinforced polymer (CFRP sheets. The beams are strengthened from the bottom side only by varied sheet lengths (full and partial beam lengths and then subjected to ultimate flexural loads. Three surface interaction techniques are used to implement the bonding behaviour between the steel tube and the CFRP sheet, namely, full tie interaction (TI, cohesive element (CE and cohesive behaviour (CB techniques using ABAQUS software. Results of the comparison between the FE analysis and existing experimental study confirm that the FE models with the TI technique could be applicable for beams strengthened by CFRP sheets with a full wrapping length; the technique could not accurately implement the CFRP delamination failure, which occurred for beams with a partial wrapping length. Meanwhile, the FE models with the CE and CB techniques are applicable in the implementation of both CFRP failures (rapture and delamination for both full and partial wrapping lengths, respectively. Where, the ultimate loads' ratios achieved by the FE models using TI, CE and CB techniques about 1.122, 1.047 and 1.045, respectively, comparing to the results of existing experimental tests.

  15. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    International Nuclear Information System (INIS)

    Sánchez, Raquel; Todolí, José Luis; Lienemann, Charles-Philippe; Mermet, Jean-Michel

    2013-01-01

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques. - Highlights: • Analysis of petroleum products by inductively coupled plasma techniques is revisited. • Fundamental studies are included together with reports dealing with applications. • Conventional and non-conventional sample introduction methods are considered. • Sample preparation methods are critically compared and described

  16. Air-coupled ultrasound: a novel technique for monitoring the curing of thermosetting matrices.

    Science.gov (United States)

    Lionetto, Francesca; Tarzia, Antonella; Maffezzoli, Alfonso

    2007-07-01

    A custom-made, air-coupled ultrasonic device was applied to cure monitoring of thick samples (7-10 mm) of unsaturated polyester resin at room temperature. A key point was the optimization of the experimental setup in order to propagate compression waves during the overall curing reaction by suitable placement of the noncontact transducers, placed on the same side of the test material, in the so-called pitch-catch configuration. The progress of polymerization was monitored through the variation of the time of flight of the propagating longitudinal waves. The exothermic character of the polymerization was taken into account by correcting the measured value of time of flight with that one in air, obtained by sampling the air velocity during the experiment. The air-coupled ultrasonic results were compared with those obtained from conventional contact ultrasonic measurements. The good agreement between the air-coupled ultrasonic results and those obtained by the rheological analysis demonstrated the reliability of air-coupled ultrasound in monitoring the changes of viscoelastic properties at gelation and vitrification. The position of the transducers on the same side of the sample makes this technique suitable for on-line cure monitoring during several composite manufacturing technologies.

  17. Reconstruction of emission coefficients for a non-axisymmetric coupling arc by algebraic reconstruction technique

    International Nuclear Information System (INIS)

    Zhang Guangjun; Xiong Jun; Gao Hongming; Wu Lin

    2011-01-01

    A preliminary investigation of tomographic reconstruction of an asymmetric arc plasma has been carried out. The objective of this work aims at reconstructing emission coefficients of a non-axisymmetric coupling arc from measured intensities by means of an algebraic reconstruction technique (ART). In order to define the optimal experimental scheme for good quality with limited views, the dependence of the reconstruction quality on three configurations (four, eight, ten projection angles) are presented and discussed via a displaced Gaussian model. Then, the emission coefficients of a free burning arc are reconstructed by the ART with the ten-view configuration and an Abel inversion, respectively, and good agreement is obtained. Finally, the emission coefficient profiles of the coupling arc are successfully achieved with the ten-view configuration. The results show that the distribution of emission coefficient for the coupling arc is different from centrosymmetric shape. The ART is perfectly suitable for reconstructing emission coefficients of the coupling arc with the ten-view configuration, proving the feasibility and utility of the ART to characterize an asymmetric arc.

  18. Dynamic pull-in instability of geometrically nonlinear actuated micro-beams based on the modified couple stress theory

    Directory of Open Access Journals (Sweden)

    Hamid M. Sedighi

    Full Text Available This paper investigates the dynamic pull-in instability of vibrating micro-beams undergoing large deflection under electrosatically actuation. The governing equation of motion is derived based on the modified couple stress theory. Homotopy Perturbation Method is employed to produce the high accuracy approximate solution as well as the second-order frequency- amplitude relationship. The nonlinear governing equation of micro beam vibrations predeformed by an electric field includes both even and odd nonlinearities. The influences of basic non-dimensional parameters on the pull-in instability as well as the natural frequency are studied. It is demonstrated that two terms in series expansions are sufficient to produce high accuracy solution of the micro-structure. The accuracy of proposed asymptotic approach is validated via numerical results. The phase portrait of the system exhibits periodic and homoclinic orbits.

  19. Vane coupling rings: a simple technique for stabilizing a four-vane radiofrequency quadrupole structure

    International Nuclear Information System (INIS)

    Howard, D.; Lancaster, H.

    1983-01-01

    The benefits of stabilized accelerating structures, with regard to the manufacture and operation, have been well documented. The four-vane radiofrequency quadrupoles (RFQ) presently being designed and constructed in many laboratories are not stabilized because of the weak electromagnetic coupling between the quadrant resonators. This paper presents a simple technique developed at the Lawrence Berkeley Laboratory using vane coupling rings (VCR's) which azimuthally stabilize the RFQ structure and greatly enhance its use as a practical accelerator. In particular, the VCR's: Completely eliminate the dipole modes in the frequency range of interest; Provide adequate quadrant balance with an initial precision mechanical alignment of the vanes; Enhance axial balance and simplify end tuners. Experimental verification tests on a scale model will be discussed

  20. Vane coupling rings: a simple technique for stabilizing a four-vane radiofrequency quadrupole structure

    International Nuclear Information System (INIS)

    Howard, D.; Lancaster, H.

    1982-11-01

    The benefits of stabilized accelerating structures, with regard to the manufacture and operation, have been well documented. The four-vane radiofrequency quadrupoles (RFQ) presently being designed and constructed in many laboratories are not stabilized because of the weak electromagnetic coupling between the quadrant resonators. This paper presents a simple technique developed at the Lawrence Berkeley Laboratory using vane coupling rings (VCR's) which azimuthally stabilize the RFQ structure and greatly enhance its use as a practical accelerator. In particular, the VCR's: completely eliminate the dipole modes in the frequency range of interest; provide adequate quadrant balance with an initial precision mechanical alignment of the vanes; and enhance axial balance and simplify end tuners. Experimental verification tests on a scale model are discussed

  1. Characterization techniques for the high-brightness particle beams of the Advanced Photon Source (APS)

    International Nuclear Information System (INIS)

    Lumpkin, A.H.

    1993-01-01

    The Advanced Photon Source (APS) will be a third-generation synchrotron radiation (SR) user facility in the hard x-ray regime (10--100 keV). The design objectives for the 7-GeV storage ring include a positron beam natural emittance of 8 x 10 -9 m-rad at an average current of 100 mA. Proposed methods for measuring the transverse and longitudinal profiles will be described. Additionally, a research and development effort using an rf gun as a low-emittance source of electrons for injection into the 200- to 650-MeV linac subsystem is underway. This latter system is projected to produce electron beams with a normalized, rms emittance of ∼2 π mm-mrad at peak currents of near one hundred amps. This interesting characterization problem will also be briefly discussed. The combination of both source types within one laboratory facility will stimulate the development of diagnostic techniques in these parameter spaces

  2. Reliability study of a prestressed concrete beam by Monte Carlo techniques

    International Nuclear Information System (INIS)

    Floris, C.; Migliacci, A.

    1987-01-01

    The safety of a prestressed beam is studied at the third probabilistic level and so calculating the probability of failure (P f ) under known loads. Since the beam is simply supported and subject only to loads perpendicular to its axis, only bending and shear loads are present. Since the ratio between the span and the clear height is over 20 with thus a very considerable shear span, it can be assumed that failure occurs entirely due to the bending moment, with shear having no effect. In order to calculate P f the probability density function (p.d.f.) have to be known both for the stress moment and the resisting moment. Attention here is focused on the construction of the latter. It is shown that it is practically impossible to find the required function analytically. On the other hand, numerical simulation with the help of a computer is particularly convenient. The so-called Monte Carlo techniques were chosen: they are based on the extraction of random numbers and are thus very suitable for simulating random events and quantities. (orig./HP)

  3. Optimisation of 12 MeV electron beam simulation using variance reduction technique

    International Nuclear Information System (INIS)

    Jayamani, J; Aziz, M Z Abdul; Termizi, N A S Mohd; Kamarulzaman, F N Mohd

    2017-01-01

    Monte Carlo (MC) simulation for electron beam radiotherapy consumes a long computation time. An algorithm called variance reduction technique (VRT) in MC was implemented to speed up this duration. This work focused on optimisation of VRT parameter which refers to electron range rejection and particle history. EGSnrc MC source code was used to simulate (BEAMnrc code) and validate (DOSXYZnrc code) the Siemens Primus linear accelerator model with the non-VRT parameter. The validated MC model simulation was repeated by applying VRT parameter (electron range rejection) that controlled by global electron cut-off energy 1,2 and 5 MeV using 20 × 10 7 particle history. 5 MeV range rejection generated the fastest MC simulation with 50% reduction in computation time compared to non-VRT simulation. Thus, 5 MeV electron range rejection utilized in particle history analysis ranged from 7.5 × 10 7 to 20 × 10 7 . In this study, 5 MeV electron cut-off with 10 × 10 7 particle history, the simulation was four times faster than non-VRT calculation with 1% deviation. Proper understanding and use of VRT can significantly reduce MC electron beam calculation duration at the same time preserving its accuracy. (paper)

  4. Comparison of the NPL water calorimeter with other dosimetric techniques for high energy photon beams

    International Nuclear Information System (INIS)

    Rosser, K.E.; Williams, A.J.

    1999-01-01

    At present, the primary standard of absorbed dose to water at NPL in high energy photon beams is a graphite calorimeter. However the quantity of interest in radiation dosimetry is absorbed dose to water. Therefore, a new absorbed dose to water standard based on water calorimetry is being developed at NPL. The calorimeter operates at 4 deg. C, with temperature control being provided by a combination of liquid and air cooling. The sealed glass inner vessel of the calorimeter has been designed to minimise the effect of non-water materials on the measurement of absorbed dose. Measurements of absorbed dose to water made in 6, 10 and 19 MV photon beams agreed within the measurement uncertainties with those determined using the primary standard graphite calorimeter. Also the absorbed dose to water measured using the water calorimeter agrees with that based on the air kerma standards for 60 Co γ-radiation within the uncertainties. The development of the water calorimeter will lead to a very robust dosimetry system at NPL, where the absorbed dose to water can be determined using three independent techniques. (author)

  5. Laser cooled ion beams and strongly coupled plasmas for precision experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bussmann, Michael

    2008-03-17

    This cumulative thesis summarizes experimental and theoretical results on cooling of ion beams using single-frequency, single-mode tabletop laser systems. It consists of two parts. One deals with experiments on laser-cooling of ion beams at relativistic energies, the other with simulations of stopping and sympathetic cooling of ions for precision in-trap experiments. In the first part, experimental results are presented on laser-cooling of relativistic C{sup 3+} ion beams at a beam energy of 122 MeV/u, performed at the Experimental Storage Ring (ESR) at GSI. The main results presented in this thesis include the first attainment of longitudinally space-charge dominated relativistic ion beams using pure laser-cooling. The second part lists theoretical results on stopping and sympathetic cooling of ions in a laser-cooled one-component plasma of singly charged {sup 24}Mg ions, which are confined in a three-dimensional harmonic trap potential. (orig.)

  6. FEM Analysis of Beam-coupling Impedance and RF Contacts Criticality on the LHC UA9 Piezo Goniometer

    CERN Document Server

    Danisi, A; Passarelli, A; Masi, A; Losito, R; Salvant, B

    2014-01-01

    The UA9 piezo-goniometer has been designed to guarantee micro-radians-accuracy angular positioning of a silicon crystal for a crystal collimation experiment in the LHC, and to minimize the impact on the LHC beam coupling impedance. This paper presents a Finite Element Method (FEM) study of the device, in both parking and operational positions, to evaluate its impact on the LHC impedance budget. In addition, the shielding contribution of the RF gaskets has been carefully evaluated, with the objective to assess the consequences for operation in case of their failure. A final word is drawn on the overall device impedance criticality.

  7. Application of wire beam electrode technique to investigate initiation and propagation of rebar corrosion

    International Nuclear Information System (INIS)

    Shi, Wei; Dong, Ze Hua; Kong, De Jie; Guo, Xing Peng

    2013-01-01

    Multi-electrode technique named as wire beam electrode (WBE) was used to study pitting corrosion of rebar under concrete cover. When WBE embedded mortar sample was immersed in NaCl solution, uneven distributions of galvanic current and open circuit potential (OCP) on the WBE were observed due to the initiation of pitting corrosion. The following oxygen depletion in mortar facilitated the negative shift of the OCP and the smoothing of the current and potential distributions. Wetting–drying cycle experiments showed that corrosion products instead of oxygen in wet mortar specimen sustained the propagation of pitting corrosion due to Fe (III) taking part in cathodic depolarization during oxygen-deficient wet period, which was confirmed by micro-Raman spectroscopy. In addition, new pitting corrosion occurred mainly near the corrosion products, leading to preferentially horizontal propagation of rust layer on the WBE. A localized corrosion factor was further presented to quantify the localised corrosion based on galvanic current maps

  8. Application of wire beam electrode technique to investigate initiation and propagation of rebar corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Wei; Dong, Ze Hua, E-mail: zehua.dong@gmail.com; Kong, De Jie; Guo, Xing Peng

    2013-06-15

    Multi-electrode technique named as wire beam electrode (WBE) was used to study pitting corrosion of rebar under concrete cover. When WBE embedded mortar sample was immersed in NaCl solution, uneven distributions of galvanic current and open circuit potential (OCP) on the WBE were observed due to the initiation of pitting corrosion. The following oxygen depletion in mortar facilitated the negative shift of the OCP and the smoothing of the current and potential distributions. Wetting–drying cycle experiments showed that corrosion products instead of oxygen in wet mortar specimen sustained the propagation of pitting corrosion due to Fe (III) taking part in cathodic depolarization during oxygen-deficient wet period, which was confirmed by micro-Raman spectroscopy. In addition, new pitting corrosion occurred mainly near the corrosion products, leading to preferentially horizontal propagation of rust layer on the WBE. A localized corrosion factor was further presented to quantify the localised corrosion based on galvanic current maps.

  9. Characterization of natural and modified zeolites using ion beam analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, E. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico)], E-mail: andrade@fisica.unam.mx; Solis, C. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico); Aceves, J.M.; Miranda, R. [Facultad de Estudios Superiores Cuautitlan Itzcalli, Departamento de Quimica, Universidad Nacional Autonoma de Mexico, 1 de Mayo S/N, Cuatitlan Itzcalli, Edo. de Mexico, C.P. 74540 (Mexico); Cruz, J. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico); Rocha, M.F. [Escuela Superior de Ingenieria Mecanica y Electrica, Instituto Politecnico Nacional, U.P. ' Adolfo Lopez Mateos' , Zacatenco, Del. Gustavo A. Madero, Mexico D.F. 07738 (Mexico); Zavala, E.P. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico)

    2008-05-15

    Zeolites are very important materials in catalytic and industrial processes. Natural, modified and synthetic zeolites have a wide range of uses because of their good adsorption, ion exchange capacity and catalytic properties. Mexico is an import source of natural zeolites, however their utilization in the natural form is limited due to the presence of trace metallic impurities. For example, metals such as vanadium and chromium inhibit the elimination of sulfur in hydrocarbons. Therefore, it is important to know the precise composition of the zeolite material. In this work, we report the elemental characterization of zeolites using various IBA techniques. {sup 3}He{sup +} and {sup 2}H{sup +} beams were used to measure the major element concentrations (Si, Al, O, C) by RBS and NRA. PIXE and SEM-EDS were used to measure the total trace element content (V, Cr, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Pb, etc). Additionally, XRD was used to study the zeolite crystal structure.

  10. Applications of factor analysis to electron and ion beam surface techniques

    International Nuclear Information System (INIS)

    Solomon, J.S.

    1987-01-01

    Factor analysis, a mathematical technique for extracting chemical information from matrices of data, is used to enhance Auger electron spectroscopy (AES), core level electron energy loss spectroscopy (EELS), ion scattering spectroscopy (ISS), and secondary ion mass spectroscopy (SIMS) in studies of interfaces, thin films, and surfaces. Several examples of factor analysis enhancement of chemical bonding variations in thin films and at interfaces studied with AES and SIMS are presented. Factor analysis is also shown to be of great benefit in quantifying electron and ion beam doses required to induce surface damage. Finally, examples are presented of the use of factor analysis to reconstruct elemental profiles when peaks of interest overlap each other during the course of depth profile analysis. (author)

  11. Novel method for the production of spin-aligned RI beams in projectile fragmentation reaction with the dispersion matching technique

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Y., E-mail: yuichikawa@phys.titech.ac.jp [Tokyo Institute of Technology, Department of Physics (Japan); Ueno, H. [RIKEN Nishina Center (Japan); Ishii, Y. [Tokyo Institute of Technology, Department of Physics (Japan); Furukawa, T. [Tokyo Metropolitan University, Department of Physics (Japan); Yoshimi, A. [Okayama University, Research Core for Extreme Quantum World (Japan); Kameda, D.; Watanabe, H.; Aoi, N. [RIKEN Nishina Center (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan); Balabanski, D. L. [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria); Chevrier, R.; Daugas, J. M. [CEA, DAM, DIF (France); Fukuda, N. [RIKEN Nishina Center (Japan); Georgiev, G. [CSNSM, IN2P3-CNRS, Universite Paris-sud (France); Hayashi, H.; Iijima, H. [Tokyo Institute of Technology, Department of Physics (Japan); Inabe, N. [RIKEN Nishina Center (Japan); Inoue, T. [Tokyo Institute of Technology, Department of Physics (Japan); Ishihara, M.; Kubo, T. [RIKEN Nishina Center (Japan); and others

    2013-05-15

    A novel method to produce spin-aligned rare-isotope (RI) beam has been developed, that is the two-step projectile fragmentation method with a technique of dispersion matching. The present method was verified in an experiment at the RIKEN RIBF, where an RI beam of {sup 32}Al with spin alignment of 8(1) % was successfully produced from a primary beam of {sup 48}Ca, with {sup 33}Al as an intermediate nucleus. Figure of merit of the present method was found to be improved by a factor larger than 50 compared with a conventional method employing single-step projectile fragmentation.

  12. The longitudinal offset technique for apodization of coupled resonator optical waveguide devices: concept and fabrication tolerance analysis.

    Science.gov (United States)

    Doménech, José David; Muñoz, Pascual; Capmany, José

    2009-11-09

    In this paper, a novel technique to set the coupling constant between cells of a coupled resonator optical waveguide (CROW) device, in order to tailor the filter response, is presented. The technique is demonstrated by simulation assuming a racetrack ring resonator geometry. It consists on changing the effective length of the coupling section by applying a longitudinal offset between the resonators. On the contrary, the conventional techniques are based in the transversal change of the distance between the ring resonators, in steps that are commonly below the current fabrication resolution step (nm scale), leading to strong restrictions in the designs. The proposed longitudinal offset technique allows a more precise control of the coupling and presents an increased robustness against the fabrication limitations, since the needed resolution step is two orders of magnitude higher. Both techniques are compared in terms of the transmission esponse of CROW devices, under finite fabrication resolution steps.

  13. Numerical Calculation of the Phase Space Density for the Strong-Strong Beam-Beam Interaction

    International Nuclear Information System (INIS)

    Sobol, A.; Ellison, J.A.

    2003-01-01

    We developed a parallel code to calculate the evolution of the 4D phase space density of two colliding beams, which are coupled via the collective strong-strong beam-beam interaction, in the absence of diffusion and damping, using the Perron-Frobenius (PF) operator technique

  14. Probing Anomalous WW γ and WWZ Couplings with Polarized Electron Beam at the LHeC and FCC-Ep Collider

    CERN Document Server

    Turk Cakir, I; Tasci, A T; Cakir, O

    2016-01-01

    We study the anomalous WWγ and WWZ couplings by calculating total cross sections of two processes at the LHeC with electron beam energy Ee=140 GeV and the proton beam energy Ep=7 TeV, and at the FCC-ep collider with the polarized electron beam energy Ee=80 GeV and the proton beam energy Ep=50 TeV. At the LHeC with electron beam polarization, we obtain the results for the difference of upper and lower bounds as (0.975, 0.118) and (0.285, 0.009) for the anomalous (∆κγ, λγ) and (∆κz, λz) couplings, respectively. As for FCC-ep collider, these bounds are obtained as (1.101, 0.065) and (0.320, 0.002) at an integrated luminosity of Lint=100 fb-1.

  15. On the choice of beam polarization in e{sup +}e{sup -} → ZZ/Zγ and anomalous triple gauge-boson couplings

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, Rafiqul; Singh, Ritesh K. [Indian Institute of Science Education and Research Kolkata, Department of Physical Sciences, Mohanpur (India)

    2017-08-15

    The anomalous trilinear gauge couplings of Z and γ are studied in e{sup +}e{sup -} → ZZ/Zγ with longitudinal beam polarizations using a complete set of polarization asymmetries for the Z boson. We quantify the goodness of the beam polarization in terms of the likelihood and find the best choice of e{sup -} and e{sup +} polarizations to be (+0.16, -0.16), (+0.09, -0.10) and (+0.12, -0.12) for ZZ, Zγ and combined processes, respectively. Simultaneous limits on anomalous couplings are obtained for these choices of beam polarizations using Markov-Chain-Monte-Carlo (MCMC) for an e{sup +}e{sup -} collider running at √(s) = 500 GeV and L = 100 fb{sup -1}. We find the simultaneous limits for these beam polarizations to be comparable with each other and also comparable with the unpolarized beam case. (orig.)

  16. Triply coupled vibrational band gap in a periodic and nonsymmetrical axially loaded thin-walled Bernoulli-Euler beam including the warping effect

    International Nuclear Information System (INIS)

    Yu Dianlong; Fang Jianyu; Cai Li; Han Xiaoyun; Wen Jihong

    2009-01-01

    The propagation of triply coupled vibrations in a periodic, nonsymmetrical and axially loaded thin-walled Bernoulli-Euler beam composed of two kinds of materials is investigated with the transfer matrix method. The cross-section of the beam lacks symmetrical axes, and bending vibrations in the two perpendicular directions are coupled with torsional vibrations. Furthermore, the effect of warping stiffness is included. The band structures of the periodic beam, both including and excluding the warping effect, are obtained. The frequency response function of the finite periodic beam is simulated with the finite element method. These simulations show large vibration-based attenuation in the frequency range of the gap, as expected. By comparing the band structure of the beam with plane wave expansion method calculations that are available in the literature, one finds that including the warping effect leads to a more accurate simulation. The effects of warping stiffness and axial force on the band structure are also discussed.

  17. Characteristics of a laser beam produced by using thermal lensing effect compensation in a fiber-coupled laser-diode-pumped Nd:YAG ceramic laser

    International Nuclear Information System (INIS)

    Kim, Duck-Lae; Kim, Byung-Tai

    2010-01-01

    The characteristics of a laser beam produced by using thermal lensing effect compensation in a fiber-coupled laser-diode Nd:YAG ceramic laser were investigated. The thermal lensing effect was compensated for by using a compensator, which was 25 mm away from the laser rod, with a focal length of 30 mm and an effective clear aperture of 22 mm. Using a compensator, the divergence and the beam propagation factor M 2 of the output beam were 5.5 mrad and 2.4, respectively, under a pump power of 12W. The high-frequency components in the compensated laser beam were removed.

  18. High resolution spectroscopy of 1,2-difluoroethane in a molecular beam: A case study of vibrational mode-coupling

    Science.gov (United States)

    Mork, Steven W.; Miller, C. Cameron; Philips, Laura A.

    1992-09-01

    The high resolution infrared spectrum of 1,2-difluoroethane (DFE) in a molecular beam has been obtained over the 2978-2996 cm-1 spectral region. This region corresponds to the symmetric combination of asymmetric C-H stretches in DFE. Observed rotational fine structure indicates that this C-H stretch is undergoing vibrational mode coupling to a single dark mode. The dark mode is split by approximately 19 cm-1 due to tunneling between the two identical gauche conformers. The mechanism of the coupling is largely anharmonic with a minor component of B/C plane Coriolis coupling. Effects of centrifugal distortion along the molecular A-axis are also observed. Analysis of the fine structure identifies the dark state as being composed of C-C torsion, CCF bend, and CH2 rock. Coupling between the C-H stretches and the C-C torsion is of particular interest because DFE has been observed to undergo vibrationally induced isomerization from the gauche to trans conformer upon excitation of the C-H stretch.

  19. A new strategy for wear and corrosion measurements using ion beam based techniques

    International Nuclear Information System (INIS)

    Dudu, D.; Popa, V.; Racolta, P.M.; Voiculescu, Dana

    2001-01-01

    An efficient and precise method for wear testing is Thin Layer Activation (TLA), which is based on the production of a thin layer of radioisotopes in the component surface by bombardment with a charged particle beam. These radioisotopes decay by emitting a characteristic gamma radiation that can be detected with thallium activated sodium iodide NaI(Tl) detectors. Since the material loss due to wear or corrosion is directly proportional to the loss in radioactivity of the activated surface, the wear/corrosion can be monitored in real time. Alternatively, the increase of the activity of the removed material debris collected in an oil bath of engine or in a filter also gives a measure of wear. The application of TLA and UTLA (ultra TLA - by recoil implantation) techniques presupposes establishing the optimum working and measuring conditions for the following steps: irradiation, post irradiation, and 'in situ' measurements. Having in view the diversity of components subjected to wear or corrosion to TLA-based investigations, dedicated beam lines for in-air or vacuum irradiation and translating/rotating target holders were developed by the U-120 Cyclotron of IFIN-HH. The modified IFIN-HH U-120 cyclotron from Bucharest is a classical variable energy machine that can accelerate protons up to 14 MeV, deuterons up to 13.5 MeV, and alpha particles up to 27 MeV. At this machine, TLA has mainly been used for studies of various parts of running machines on test benches such as piston - rings and linear cylinders. Also lubricant characterization studies were conducted here. The main advantage of TLA compared to conventional techniques for wear measurements is its ability to perform continuous in situ wear measurements of engine components, such as cylinder liners and piston rings, without the need to dismantle the components investigated. In addition high wear sensitivity and resolution of wear down to nano meters dimensions is guaranteed. Although the level of activity used in

  20. On the (Frequency) Modulation of Coupled Oscillator Arrays in Phased Array Beam Control

    Science.gov (United States)

    Pogorzelski, R.; Acorn, J.; Zawadzki, M.

    2000-01-01

    It has been shown that arrays of voltage controlled oscillators coupled to nearest neighbors can be used to produce useful aperture phase distributions for phased array antennas. However, placing information of the transmitted signal requires that the oscillations be modulated.

  1. Development of a Fast Fluid-Structure Coupling Technique for Wind Turbine Computations

    DEFF Research Database (Denmark)

    Sessarego, Matias; Ramos García, Néstor; Shen, Wen Zhong

    2015-01-01

    Fluid-structure interaction simulations are routinely used in the wind energy industry to evaluate the aerodynamic and structural dynamic performance of wind turbines. Most aero-elastic codes in modern times implement a blade element momentum technique to model the rotor aerodynamics and a modal......, multi-body, or finite-element approach to model the turbine structural dynamics. The present paper describes a novel fluid-structure coupling technique which combines a threedimensional viscous-inviscid solver for horizontal-axis wind-turbine aerodynamics, called MIRAS, and the structural dynamics model...... used in the aero-elastic code FLEX5. The new code, MIRASFLEX, in general shows good agreement with the standard aero-elastic codes FLEX5 and FAST for various test cases. The structural model in MIRAS-FLEX acts to reduce the aerodynamic load computed by MIRAS, particularly near the tip and at high wind...

  2. Determination of Rare Earth Elements in Thai Monazite by Inductively Coupled Plasma and Nuclear Analytical techniques

    International Nuclear Information System (INIS)

    Busamongkol, Arporn; Ratanapra, Dusadee; Sukharn, Sumalee; Laoharojanaphand, Sirinart

    2003-10-01

    The inductively coupled plasma atomic emission spectroscopy (ICP-AES) for the determination of individual rare-earth elements (REE) was evaluated by comparison with instrumental neutron activation analysis (INAA) and x-ray fluorescence spectrometry (XRF). The accuracy and precision of INAA and ICP-AES were evaluated by using standard reference material IGS-36, a monazite concentrate. For INAA, the results were close to the certified value while ICP-AES were in good agreement except for some low concentration rare earth. The techniques were applied for the analysis of some rare earth elements in two Thai monazite samples preparing as the in-house reference material for the Rare Earth Research and Development Center, Chemistry Division, Office of Atoms for Peace. The analytical results obtained by these techniques were in good agreement with each other

  3. Chaotic synchronization of vibrations of a coupled mechanical system consisting of a plate and beams

    Directory of Open Access Journals (Sweden)

    J. Awrejcewicz

    Full Text Available In this paper mathematical model of a mechanical system consisting of a plate and either one or two beams is derived. Obtained PDEs are reduced to ODEs, and then studied mainly using the fast Fourier and wavelet transforms. A few examples of the chaotic synchronizations are illustrated and discussed.

  4. Probing anomalous Higgs couplings at an eγ collider using unpolarized beams

    International Nuclear Information System (INIS)

    Choudhury, Debajyoti; Mamta

    2007-01-01

    We examine the sensitivity of e γ colliders (based on e + e - linear colliders of c.m. energy 500 GeV) to the anomalous couplings of the Higgs to W-boson via the process e - γ → νWH. This has the advantage over e + e - collider in being able to dissociate WWH vertex from ZZH. We are able to construct several dynamical variables which may be used to constrain the various couplings in the WWH vertex. (author)

  5. Robust breathing signal extraction from cone beam CT projections based on adaptive and global optimization techniques

    International Nuclear Information System (INIS)

    Chao, Ming; Yuan, Yading; Rosenzweig, Kenneth E; Lo, Yeh-Chi; Wei, Jie; Li, Tianfang

    2016-01-01

    We present a study of extracting respiratory signals from cone beam computed tomography (CBCT) projections within the framework of the Amsterdam Shroud (AS) technique. Acquired prior to the radiotherapy treatment, CBCT projections were preprocessed for contrast enhancement by converting the original intensity images to attenuation images with which the AS image was created. An adaptive robust z-normalization filtering was applied to further augment the weak oscillating structures locally. From the enhanced AS image, the respiratory signal was extracted using a two-step optimization approach to effectively reveal the large-scale regularity of the breathing signals. CBCT projection images from five patients acquired with the Varian Onboard Imager on the Clinac iX System Linear Accelerator (Varian Medical Systems, Palo Alto, CA) were employed to assess the proposed technique. Stable breathing signals can be reliably extracted using the proposed algorithm. Reference waveforms obtained using an air bellows belt (Philips Medical Systems, Cleveland, OH) were exported and compared to those with the AS based signals. The average errors for the enrolled patients between the estimated breath per minute (bpm) and the reference waveform bpm can be as low as  −0.07 with the standard deviation 1.58. The new algorithm outperformed the original AS technique for all patients by 8.5% to 30%. The impact of gantry rotation on the breathing signal was assessed with data acquired with a Quasar phantom (Modus Medical Devices Inc., London, Canada) and found to be minimal on the signal frequency. The new technique developed in this work will provide a practical solution to rendering markerless breathing signal using the CBCT projections for thoracic and abdominal patients. (paper)

  6. Measurement of g factors of excited states in radioactive beams by the transient field technique: 132Te

    International Nuclear Information System (INIS)

    Benczer-Koller, N.; Kumbartzki, G.; Gurdal, G; Gross, Carl J; Krieger, B; Hatarik, Robert; O'Malley, Patrick; Pain, S. D.; Segen, L.; Baktash, Cyrus; Bingham, C. R.; Danchev, M.; Grzywacz, R.; Mazzocchi, C.

    2008-01-01

    The g factor of the 2 1 + state in 52 132 Te, E(2 1 + ) = 0.9739 MeV, r = 2.6 ps, was measured by the transient field technique applied to a radioactive beam. The development of an experimental approach necessary for work in radioactive beam environments is described. The result g = 0.28(15) agrees with the previous measurement by the recoil-in-vacuum technique, but here the sign of the g factor is measured as well

  7. The Use of Coupled Code Technique for Best Estimate Safety Analysis of Nuclear Power Plants

    International Nuclear Information System (INIS)

    Bousbia Salah, A.; D'Auria, F.

    2006-01-01

    Issues connected with the thermal-hydraulics and neutronics of nuclear plants still challenge the design, safety and the operation of Light Water nuclear Reactors (LWR). The lack of full understanding of complex mechanisms related to the interaction between these issues imposed the adoption of conservative safety limits. Those safety margins put restrictions on the optimal exploitation of the plants and consequently reduced economic profit of the plant. In the light of the sustained development in computer technology, the possibilities of code capabilities have been enlarged substantially. Consequently, advanced safety evaluations and design optimizations that were not possible few years ago can now be performed. In fact, during the last decades Best Estimate (BE) neutronic and thermal-hydraulic calculations were so far carried out following rather parallel paths with only few interactions between them. Nowadays, it becomes possible to switch to new generation of computational tools, namely, Coupled Code technique. The application of such method is mandatory for the analysis of accident conditions where strong coupling between the core neutronics and the primary circuit thermal-hydraulics, and more especially when asymmetrical processes take place in the core leading to local space-dependent power generation. Through the current study, a demonstration of the maturity level achieved in the calculation of 3-D core performance during complex accident scenarios in NPPs is emphasized. Typical applications are outlined and discussed showing the main features and limitations of this technique. (author)

  8. Technique for Extension of Small Antenna Array Mutual-Coupling Data to Larger Antenna Arrays

    Science.gov (United States)

    Bailey, M. C.

    1996-01-01

    A technique is presented whereby the mutual interaction between a small number of elements in a planar array can be interpolated and extrapolated to accurately predict the combined interactions in a much larger array of many elements. An approximate series expression is developed, based upon knowledge of the analytical characteristic behavior of the mutual admittance between small aperture antenna elements in a conducting ground plane. This expression is utilized to analytically extend known values for a few spacings and orientations to other element configurations, thus eliminating the need to numerically integrate a large number of highly oscillating and slowly converging functions. This paper shows that the technique can predict very accurately the mutual coupling between elements in a very large planar array with a knowledge of the self-admittance of an isolated element and the coupling between only two-elements arranged in eight different pair combinations. These eight pair combinations do not necessarily have to correspond to pairs in the large array, although all of the individual elements must be identical.

  9. Determining mode I cohesive law of Pinus pinaster by coupling double cantilever beam test with digital image correlation

    Directory of Open Access Journals (Sweden)

    J. Xavier

    2015-01-01

    Full Text Available The direct identification of the cohesive law in pure mode I of Pinus pinaster is addressed. The approach couples the double cantilever beam (DCB test with digital image correlation (DIC. Wooden beam specimens loaded in the radial-longitudinal (RL fracture propagation system are used. The strain energy release rate in mode I ( is uniquely determined from the load-displacement ( curve by means of the compliance-based beam method (CBBM. This method relies on the concept of equivalent elastic crack length ( and therefore does not require the monitoring of crack propagation during test. The crack tip opening displacement in mode I is determined from the displacement field at the initial crack tip. The cohesive law in mode I is then identified by numerical differentiation of the relationship. Moreover, the proposed procedure is validated by finite element analyses including cohesive zone modelling. It is concluded that the proposed data reduction scheme is adequate for assessing the cohesive law in pure mode I of P. pinaster

  10. Signal processing techniques for lithium beam polarimetry on DIII-D

    International Nuclear Information System (INIS)

    Thomas, D. M.; Leonard, A. W.

    2006-01-01

    On the DIII-D tokamak the LIBEAM diagnostic provides precise measurements of the local magnetic field direction by combined polarimetry/ spectroscopy of the Zeeman-split 2S-2P lithium resonance line. Using these measurements we are able to determine the behavior of the edge toroidal current density j φ (r), a parameter of critical interest for edge stability and performance. For a successful measurement, analysis of the polarization state of the spectrally filtered fluorescence must be done with high precision in the presence of nonideal filtering, beam intensity evolution, and dynamically varying background light. This is accomplished by polarization modulation of the collected emission, followed by digital demodulation at various harmonics of the modulation frequency. Either lock-in or fast Fourier transform techniques can be used to determine the various Stokes parameters and reconstruct the field directions based on accurate spatial and polarization efficiency calibrations. Details of the specific techniques used to analyze various DIII-D discharges are described, along with a discussion of the present limitations and some possible avenues towards improving the analysis

  11. Fabrication of superconducting MgB2 nanostructures by an electron beam lithography-based technique

    Science.gov (United States)

    Portesi, C.; Borini, S.; Amato, G.; Monticone, E.

    2006-03-01

    In this work, we present the results obtained in fabrication and characterization of magnesium diboride nanowires realized by an electron beam lithography (EBL)-based method. For fabricating MgB2 thin films, an all in situ technique has been used, based on the coevaporation of B and Mg by means of an e-gun and a resistive heater, respectively. Since the high temperatures required for the fabrication of good quality MgB2 thin films do not allow the nanostructuring approach based on the lift-off technique, we structured the samples combining EBL, optical lithography, and Ar milling. In this way, reproducible nanowires 1 μm long have been obtained. To illustrate the impact of the MgB2 film processing on its superconducting properties, we measured the temperature dependence of the resistance on a nanowire and compared it to the original magnesium diboride film. The electrical properties of the films are not degraded as a consequence of the nanostructuring process, so that superconducting nanodevices may be obtained by this method.

  12. Fabrication of high-transmission microporous membranes by proton beam writing-based molding technique

    Science.gov (United States)

    Wang, Liping; Meyer, Clemens; Guibert, Edouard; Homsy, Alexandra; Whitlow, Harry J.

    2017-08-01

    Porous membranes are widely used as filters in a broad range of micro and nanofluidic applications, e.g. organelle sorters, permeable cell growth substrates, and plasma filtration. Conventional silicon fabrication approaches are not suitable for microporous membranes due to the low mechanical stability of thin film substrates. Other techniques like ion track etching are limited to the production of randomly distributed and randomly orientated pores with non-uniform pore sizes. In this project, we developed a procedure for fabricating high-transmission microporous membranes by proton beam writing (PBW) with a combination of spin-casting and soft lithography. In this approach, focused 2 MeV protons were used to lithographically write patterns consisting of hexagonal arrays of high-density pillars of few μm size in a SU-8 layer coated on a silicon wafer. After development, the pillars were conformably coated with a thin film of poly-para-xylylene (Parylene)-C release agent and spin-coated with polydimethylsiloxane (PDMS). To facilitate demolding, a special technique based on the use of a laser-cut sealing tape ring was developed. This method facilitated the successful delamination of 20-μm thick PDMS membrane with high-density micropores from the mold without rupture or damage.

  13. Analysis and modification of blue sapphires from Rwanda by ion beam techniques

    Science.gov (United States)

    Bootkul, D.; Chaiwai, C.; Tippawan, U.; Wanthanachaisaeng, B.; Intarasiri, S.

    2015-12-01

    Blue sapphire is categorised in a corundum (Al2O3) group. The gems of this group are always amazed by their beauties and thus having high value. In this study, blue sapphires from Rwanda, recently came to Thai gemstone industry, are chosen for investigations. On one hand, we have applied Particle Induced X-ray Emission (PIXE), which is a highly sensitive and precise analytical technique that can be used to identify and quantify trace elements, for chemical analysis of the sapphires. Here we have found that the major element of blue sapphires from Rwanda is Al with trace elements such as Fe, Ti, Cr, Ga and Mg as are commonly found in normal blue sapphire. On the other hand, we have applied low and medium ion implantations for color improvement of the sapphire. It seems that a high amount of energy transferring during cascade collisions have altered the gems properties. We have clearly seen that the blue color of the sapphires have been intensified after nitrogen ion bombardment. In addition, the gems were also having more transparent and luster. The UV-Vis-NIR measurement detected the modification of their absorption properties, implying of the blue color increasing. Here the mechanism of these modifications is postulated and reported. In any point of view, the bombardment by using nitrogen ion beam is a promising technique for quality improvement of the blue sapphire from Rwanda.

  14. A simple technique for treating age-related macular degeneration with external beam radiotherapy

    International Nuclear Information System (INIS)

    Roos, Daniel E.; Francis, J. Winston; Newnham, W. John

    1999-01-01

    Purpose: To develop a simple external beam photon radiotherapy technique to treat age-related macular degeneration without the need for simulation, planning computed tomography (CT) or computer dosimetry. Methods and Materials: The goal was to enable the treatment to be set up reliably on the treatment machine on Day 1 with the patient supine in a head cast without any prior planning. Using measurements of ocular globe topography from Karlsson et al. (Int J Radiat Oncol Biol Phys 1996; 33: 705-712), we chose a point 1.5 cm behind the anterior surface of the upper eyelid (ASUE) as the isocentre of a half-beam, blocked, 5.0 x 3.0-cm, angled lateral field to treat the involved eye. This would position the isocentre about 0.5 cm behind the posterior surface of the lens, and a little over 1 cm in front of the macula, according to Karlsson et al. The setup requires initial adjustment of the gantry from horizontal (to account for any asymmetry of position of the eyes), then angling 15 deg. posteriorly to avoid the contralateral eye. Finally, the couch is raised to position the isocentre 1.5 cm behind the ASUE. Results: To verify the applicability of the technique, we performed CT and computer dosimetry on the first 11 eyes so treated. Our CT measurements were in good agreement with Karlsson et al. The lens dose was < 5% and the macula was within the 95% isodose curve in each case (6-MV linac). Treatment setup time is approximately 10 min each day. The 11 patients were treated with 5 x 2.00 Gy (2 patients) or 5 x 3.00 Gy (9 patients), and subjective response on follow-up over 1 to 12 months (median 4 months) was comparable to previously reported results, with no significant acute side effects. Conclusion: Our technique is easy to set up and reliably treats the macula, with sparing of the lens and contralateral eye. It enables treatment to commence rapidly and cost-effectively without the need for simulation or CT computer planning

  15. Designed-seamless irradiation technique for extended whole mediastinal proton-beam irradiation for esophageal cancer

    Directory of Open Access Journals (Sweden)

    Okonogi Noriyuki

    2012-10-01

    Full Text Available Abstract Background Proton-beam therapy (PBT provides therapeutic advantages over conformal x-ray therapy in sparing organs at risk when treating esophageal cancer because of the fundamental physical dose distribution of the proton-beam. However, cases with extended esophageal lesions are difficult to treat with conventional PBT with a single isocentric field, as the length of the planning target volume (PTV is longer than the available PBT field size in many facilities. In this study, the feasibility of a practical technique to effectively match PBT fields for esophageal cancer with a larger regional field beyond the available PBT field size was investigated. Methods Twenty esophageal cancer patients with a larger regional field than the available PBT single-field size (15 cm in our facility were analyzed. The PTV was divided into two sections to be covered by a single PBT field. Subsequently, each PTV isocenter was aligned in a cranial-caudal (CC axis to rule out any influence by the movement of the treatment couch in anterior-posterior and left-right directions. To obtain the appropriate dose distributions, a designed-seamless irradiation technique (D-SLIT was proposed. This technique requires the following two adjustments: (A blocking a part of the PTV by multi-leaf collimator(s (MLCs; and (B fine-tuning the isocenter distance by the half-width of the MLC leaf (2.5 mm in our facility. After these steps, the inferior border of the cranial field was designed to match the superior border of the caudal field. Dose distributions along the CC axis around the field junction were evaluated by the treatment-planning system. Dose profiles were validated with imaging plates in all cases. Results The average and standard deviation of minimum dose, maximum dose, and dose range between maximum and minimum doses around the field junction by the treatment-planning system were 95.9 ± 3.2%, 105.3 ± 4.1%, and 9.4 ± 5.2%. The dose profile validated by the

  16. NUMERICAL TECHNIQUES TO SOLVE CONDENSATIONAL AND DISSOLUTIONAL GROWTH EQUATIONS WHEN GROWTH IS COUPLED TO REVERSIBLE REACTIONS (R823186)

    Science.gov (United States)

    Noniterative, unconditionally stable numerical techniques for solving condensational anddissolutional growth equations are given. Growth solutions are compared to Gear-code solutions forthree cases when growth is coupled to reversible equilibrium chemistry. In all cases, ...

  17. A coupled bunch instability due to beam-photoelectron interactions in KEKB-LER

    Energy Technology Data Exchange (ETDEWEB)

    Ohmi, Kazuhito [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1996-08-01

    LER of KEKB is designed to storage the positron beam of 2.6 A with multibunch operation. Nb = 3.3 x 10{sup 10} positrons are filled in a bunch and the bunch passes every 2ns through a beam chamber. The photoelectron instability may be serious for KEKB-LER. We consider a motion of photoelectrons produced by a bunch with a computer simulation technic. A cylindrical chamber with a diameter of 10 cm was used as a model chamber. About 15 times of the photoelectrons were produced by a bunch. The wake force was calculated for the loading bunches with displacements of 0.5 mm and 1 mm. The wake characteristics seems to be caused by the trapped electrons kicked by the loading bunch. The wake was saturated with the loading displacement of 0.5 mm. We obtained a growth rate by the wake force. It is very high rate, 2500s{sup -1} which exceeds damping rates of various mechanism, radiation, head-tail and feedback. Perhaps it is essential to remove the photoelectrons around the positron beam explicitly. If we apply magnetic field fo about 20 G, the growth rate will be reduced. (S.Y.)

  18. Bonding techniques for flexural strengthening of R.C. beams using CFRP laminates

    Directory of Open Access Journals (Sweden)

    Alaa Morsy

    2013-09-01

    Full Text Available This paper presents an experimental study of an alternative method of attaching FRP laminates to reinforced concrete beams by the way of fasting steel rivets through the FRP laminate and concrete substrate. Five full scale R.C. beams were casted and strengthened in flexural using FRP laminate bonded with conventional epoxy and compared with other beams strengthened with FRP laminate and bonded with fastener “steel rivets” of 50 mm length and 10 mm diameter. Based on experimental evidence the beam strengthened with conventional bonding methods failed due to de-bonding with about 13% increase over the un-strengthened beam. On the other hand, the beams strengthened with FRP laminate and bonded by four steel fastener rivets only failed by de-bonding also but at higher flexural capacity with increase 19% over the un-strengthened beam.

  19. Efficient coupling of 527 nm laser beam power to a long scale-length plasma

    International Nuclear Information System (INIS)

    Moody, J.D.; Divol, L.; Glenzer, S.H.; MacKinnon, A.J.; Froula, D.H.; Gregori, G.; Kruer, W.L.; Meezan, N.B.; Suter, L.J.; Williams, E.A.; Bahr, R.; Seka, W.

    2006-01-01

    We experimentally demonstrate that application of laser smoothing schemes including smoothing by spectral dispersion (SSD) and polarization smoothing (PS) increases the intensity range for efficient coupling of frequency doubled (527 nm) laser light to a long scale-length plasma with n e /n cr equals 0.14 and T e equals 2 keV. (authors)

  20. Lung stereotactic body radiotherapy using a coplanar versus a non-coplanar beam technique: a comparison of clinical outcomes

    Science.gov (United States)

    Stauder, Michael C.; Miller, Robert C.; Garces, Yolanda I.; Foote, Robert L.; Sarkaria, Jann N.; Bauer, Heather J.; Mayo, Charles S.; Olivier, Kenneth R.

    2013-01-01

    Objectives To determine if lung stereotactic body radiotherapy (SBRT) using a coplanar beam technique was associated with similar outcomes as lung SBRT using a non-coplanar beam technique. Methods A retrospective review was performed of patients undergoing lung SBRT between January 2008 and April 2011. SBRT was initially delivered with multiple non-coplanar, non-overlapping beams; however, starting in December 2009, SBRT was delivered predominantly with all coplanar beams in order to reduce treatment time and complexity. Results This analysis included 149 patients; the median follow-up was 21 months. SBRT was delivered for primary (n = 90) or recurrent (n = 17) non-small cell lung cancer, or lung oligometastasis (n = 42). The most common dose (Gy)/fraction (fx) regimens were 48 Gy/4 fx (39%), 54 Gy/3 fx (37%), and 50 Gy/5 fx (17%). The beam arrangement was coplanar in 61 patients (41%) and non-coplanar in 88 patients (59%). In patients treated with 54 Gy/3 fx, the mean treatment times per fraction for the coplanar and non-coplanar cohorts were 10 and 14 minutes (p < 0.0001). Kaplan-Meier 2-year estimates of overall survival (OS), progression-free survival, and local control (LC) for the coplanar and non-coplanar cohorts were 65% vs. 56% (p = 0.30), 47% vs. 39% (p = 0.71), and 92% and 92% (p = 0.94), respectively. The 1-year estimates of grade 2-5 pulmonary toxicity for the coplanar and non-coplanar cohorts were 11% and 17%, respectively (p = 0.30). On multivariate analysis, beam arrangement was not significantly associated with OS, LC or pulmonary toxicity. Conclusions Patients treated with lung SBRT using a coplanar technique had similar outcomes as those treated with a non-coplanar technique. PMID:29296365

  1. Advanced Integration Techniques on Broadband Millimeter-Wave Beam Steering for 5G Wireless Networks and Beyond

    NARCIS (Netherlands)

    Cao, Zizheng; Ma, Qian; Smolders, Bart; Jiao, Yuqing; Wale, Mike; Oh, Joanne; wu, hequan; Koonen, Ton

    2015-01-01

    Recently, the desired very high throughput of 5G wireless networks drives millimeter-wave (mm-wave) communication into practical applications. A phased array technique is required to increase the effective antenna aperture at mm-wave frequency. Integrated solutions of beamforming/beam steering are

  2. Characterisation of lipid fraction of marine macroalgae by means of chromatography techniques coupled to mass spectrometry.

    Science.gov (United States)

    Ragonese, Carla; Tedone, Laura; Beccaria, Marco; Torre, Germana; Cichello, Filomena; Cacciola, Francesco; Dugo, Paola; Mondello, Luigi

    2014-02-15

    In this work the characterisation of the lipid fraction of several species of marine macro algae gathered along the eastern coast of Sicily is reported. Two species of green marine algae (Chloropyceae), two species of red marine algae (Rhodophyceae) and four species of brown marine algae (Pheophyceae) were evaluated in terms of fatty acids, triacylglycerols, pigments and phospholipids profile. Advanced analytical techniques were employed to fully characterise the lipid profile of these Mediterranean seaweeds, such as GC-MS coupled to a novel mass spectra database supported by the simultaneous use of linear retention index (LRI) for the identification of fatty acid profile; LC-MS was employed for the identification of triacylglycerols (TAGs), carotenoids and phospholipids; the determination of accurate mass was carried out on carotenoids and phospholipids. Quantitative data are reported on fatty acids and triacylglycerols as relative percentage of total fraction. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. THE MISSING FATHER FUNCTION IN PSYCHOANALYTIC THEORY AND TECHNIQUE: THE ANALYST'S INTERNAL COUPLE AND MATURING INTIMACY.

    Science.gov (United States)

    Diamond, Michael J

    2017-10-01

    This paper argues that recovering the "missing" paternal function in analytic space is essential for the patient's achievement of mature object relations. Emerging from the helpless infant's contact with primary caregivers, mature intimacy rests on establishing healthy triadic functioning based on an infant-with-mother-and-father. Despite a maternocentric bias in contemporary clinical theory, the emergence of triangularity and the inclusion of the paternal third as a separating element is vital in the analytic dyad. Effective technique requires the analyst's balanced interplay between the paternal, investigative and the maternal, maximally receptive modes of functioning-the good enough analytic couple within the analyst-to serve as the separating element that procreatively fertilizes the capacity for intimacy with a differentiated other. A clinical example illustrates how treatment is limited when the paternal function is minimized within more collusive, unconsciously symbiotic dyads. © 2017 The Psychoanalytic Quarterly, Inc.

  4. Ion source techniques for high-speed processing of material surface by ion beams

    International Nuclear Information System (INIS)

    Ishikawa, Junzo

    1990-01-01

    The present paper discusses some key or candidate techniques for future ion source development and such ion sources developed by the author. Several types of microwave ion sources for producing low charge state ions have been developed in Japan. When a microwave plasma cathode developed by the author is adapted to a Kaufman type ion source, the electron emission currents are found to be 2.5 A for argon gas and 0.5-0.9 A for oxygen gas. An alternative ionization method for metal atoms is strongly required for high-speed processing of material surface by metal-ion beams. Detailed discussion is made of collisional ionization of vaporized atoms, and negative-ion production (secondary negative-ion emission by sputtering). An impregnated electrode type liquid-metal ion source developed by the author, which has a porous tip structure, is described. The negative-ion production efficiency is quite high. The report also presents a neutral and ionized alkaline-metal bombardment type heavy negative-ion source, which consists of a cesium plasma ion source, suppressor, target electrode, negative-ion extraction electrode, and einzel lens. (N.K.)

  5. Cure and mechanical behaviors of cycloaliphatic/DGEBA epoxy blend system using electron-beam technique

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.R.; Heo, G.Y.; Park, S.J. [Korea Research Institute of Chemical Technology, Taejeon (Korea)

    2002-05-01

    4-Vinyl-1- cyclohexene diepoxide (VCE)/ diglycidyl ether of bisphenol -A(DGEBA) epoxy blends with benzylquinoxalinium hexafluoroanti-monate were cured using an electron-beam technique. the effect of DGEBA content to VCE on cure behavior, thermal stabilities, and mechanical properties was investigated. The composition of VCE/DGEBA blend system varied within 100:0, 80:20, 60:40. 40:60 20:80, and 0:100wt%. The cure behavior and thermal stability of the cured specimens was monited by near-infrared spectroscopy and thermogravimetric analysis, respectively. Also, the critical stress intensity factor (K{sub 1C}) test of the cured specimens was performed to study the mechanical interfacial properties. As a result, the decreases of short side-chide structure and chain scission were observed in NIR measurements as the DGEBA content increases, resulting in varying the hydroxyl and carbonyl groups. And, the initial decomposition temperature (IDT), temperature of maximum weight loss (T{sub max}), and decomposition activation energy (E{sub d}) as thermal stability factors were increased with increasing the DGEBA content. These results could be explained by mean of decreasing viscosity, stable aromatic ring structure, and grafted interpenetrating polymer network with increasing of DGEBA content. Also, the maximum K{sub 1C} value showed at mixing ratio of 40:60 wt% in this blend system. (author). 22 refs., 2 tabs., 6 figs.

  6. Characterization of ITO/CdO/glass thin films evaporated by electron beam technique

    Directory of Open Access Journals (Sweden)

    Hussein Abdel-Hafez Mohamed and Hazem Mahmoud Ali

    2008-01-01

    Full Text Available A thin buffer layer of cadmium oxide (CdO was used to enhance the optical and electrical properties of indium tin oxide (ITO films prepared by an electron-beam evaporation technique. The effects of the thickness and heat treatment of the CdO layer on the structural, optical and electrical properties of ITO films were carried out. It was found that the CdO layer with a thickness of 25 nm results in an optimum transmittance of 70% in the visible region and an optimum resistivity of 5.1×10−3 Ω cm at room temperature. The effect of heat treatment on the CdO buffer layer with a thickness of 25 nm was considered to improve the optoelectronic properties of the formed ITO films. With increasing annealing temperature, the crystallinity of ITO films seemed to improve, enhancing some physical properties, such as film transmittance and conductivity. ITO films deposited onto a CdO buffer layer heated at 450 °C showed a maximum transmittance of 91% in the visible and near-infrared regions of the spectrum associated with the highest optical energy gap of 3.61 eV and electrical resistivity of 4.45×10−4 Ω cm at room temperature. Other optical parameters, such as refractive index, extinction coefficient, dielectric constant, dispersion energy, single effective oscillator energy, packing density and free carrier concentration, were also studied.

  7. Transparent conducting ZnO-CdO thin films deposited by e-beam evaporation technique

    Science.gov (United States)

    Mohamed, H. A.; Ali, H. M.; Mohamed, S. H.; Abd El-Raheem, M. M.

    2006-04-01

    Thin films of Zn{1-x} Cd{x}O with x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5 at.% were deposited by electron-beam evaporation technique. It has been found that, for as-deposited films, both the transmittance and electrical resistivity decreased with increasing the Cd content. To improve the optical and electrical properties of these films, the effect of annealing temperature and time were taken into consideration for Zn{1-x} Cd{x}O film with x = 0.2. It was found that, the optical transmittance and the electrical conductivity were improved significantly with increasing the time of annealing. At fixed temperature of 300 °C, the transmittance increased with increasing the time of annealing and reached its maximum values of 81% in the visible region and 94% in the NIR region at annealing time of 120 min. The low electrical resistivity of 3.6 × 10-3 Ω cm was achieved at the same conditions. Other parameters named free carrier concentrations, refractive index, extinction coefficient, plasma frequency, and relaxation time were studied as a function of annealing temperature and time for 20% Cd content.

  8. Optical and Electrical Properties of Tin-Doped Cadmium Oxide Films Prepared by Electron Beam Technique

    Science.gov (United States)

    Ali, H. M.; Mohamed, H. A.; Wakkad, M. M.; Hasaneen, M. F.

    2009-04-01

    Tin-doped cadmium oxide films were deposited by electron beam evaporation technique. The structural, optical and electrical properties of the films were characterized. The X-ray diffraction (XRD) study reveals that the films are polycrystalline in nature. As composition and structure change due to the dopant ratio and annealing temperature, the carrier concentration was varied around 1020 cm-3, and the mobility increased from less than 10 to 45 cm2 V-1 s-1. A transmittance value of ˜83% and a resistivity value of 4.4 ×10-4 Ω cm were achieved for (CdO)0.88(SnO2)0.12 film annealed at 350 °C for 15 min., whereas the maximum value of transmittance ˜93% and a resistivity value of 2.4 ×10-3 Ω cm were obtained at 350 °C for 30 min. The films exhibited direct band-to-band transitions, which corresponded to optical band gaps of 3.1-3.3 eV.

  9. Fault Diagnosis of Beam-Like Structure Using Modified Fuzzy Technique

    Directory of Open Access Journals (Sweden)

    Dhirendranath Thatoi

    2014-01-01

    Full Text Available This paper presents a novel hybrid fuzzy logic based artificial intelligence (AI technique applicable to diagnosis of the crack parameters in a fixed-fixed beam by using the vibration signatures as input. The presence of damage in engineering structures leads to changes in vibration signatures like natural frequency and mode shapes. In the first part of this work, a structure with a failure crack has been analyzed using finite element method (FEM and retrospective changes in the vibration signatures have been recorded. In the second part of the research work, these deviations in the vibration signatures for the first three mode shapes have been taken as input parameters for a fuzzy logic based controller for calculation of crack location and its severity as output parameters. In the proposed fuzzy controller, hybrid membership functions have been taken. Several fuzzy rules have been identified for prediction of crack depth and location and the results have been compared with finite element analysis. A database of experimental results has also been considered to check the robustness of the fuzzy controller. The results show that predictions for the nondimensional crack location, α, deviate ~2.4% from experimental values and for the nondimensional crack depth, δ, are less than ~−2%.

  10. Microstructure and surface morphology of YSZ thin films deposited by e-beam technique

    International Nuclear Information System (INIS)

    Laukaitis, G.; Dudonis, J.; Milcius, D.

    2008-01-01

    In present study yttrium-stabilized zirconia (YSZ) thin films were deposited on optical quartz (amorphous SiO 2 ), porous Ni-YSZ and crystalline Alloy 600 (Fe-Ni-Cr) substrates using e-beam deposition technique and controlling technological parameters: substrate temperature and electron gun power which influence thin-film deposition mechanism. X-ray diffraction, scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to investigate how thin-film structure and surface morphology depend on these parameters. It was found that the crystallite size, roughness and growth mechanism of YSZ thin films are influenced by electron gun power. To clarify the experimental results, YSZ thin-film formation as well evolution of surface roughness at its initial growing stages were analyzed. The evolution of surface roughness could be explained by the processes of surface mobility of adatoms and coalescence of islands. The analysis of these experimental results explain that surface roughness dependence on substrate temperature and electron gun power non-monotonous which could result from diffusivity of adatoms and the amount of atomic clusters in the gas stream of evaporated material

  11. Improved Understanding of Implosion Symmetry through New Experimental Techniques Connecting Hohlraum Dynamics with Laser Beam Deposition

    Science.gov (United States)

    Ralph, Joseph; Salmonson, Jay; Dewald, Eduard; Bachmann, Benjamin; Edwards, John; Graziani, Frank; Hurricane, Omar; Landen, Otto; Ma, Tammy; Masse, Laurent; MacLaren, Stephen; Meezan, Nathan; Moody, John; Parrilla, Nicholas; Pino, Jesse; Sacks, Ryan; Tipton, Robert

    2017-10-01

    Understanding what affects implosion symmetry has been a challenge for scientists designing indirect drive inertial confinement fusion experiments on the National Ignition Facility (NIF). New experimental techniques and data analysis have been employed aimed at improving our understanding of the relationship between hohlraum dynamics and implosion symmetry. Thin wall imaging data allows for time-resolved imaging of 10 keV Au l-band x-rays providing for the first time on the NIF, a spatially resolved measurement of laser deposition with time. In the work described here, we combine measurements from the thin wall imaging with time resolved views of the interior of the hohlraum. The measurements presented are compared to hydrodynamic simulations as well as simplified physics models. The goal of this work is to form a physical picture that better explains the relationship of the hohlraum dynamics and capsule ablator on laser beam propagation and implosion symmetry. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  12. Augmenting the bioactivity of polyetheretherketone using a novel accelerated neutral atom beam technique.

    Science.gov (United States)

    Ajami, S; Coathup, M J; Khoury, J; Blunn, G W

    2017-08-01

    Polyetheretherketone (PEEK) is an alternative to metallic implants in orthopedic applications; however, PEEK is bioinert and does not osteointegrate. In this study, an accelerated neutral atom beam technique (ANAB) was employed to improve the bioactivity of PEEK. The aim was to investigate the growth of human mesenchymal stem cells (hMSCs), human osteoblasts (hOB), and skin fibroblasts (BR3G) on PEEK and ANAB PEEK. The surface roughness and contact angle of PEEK and ANAB PEEK was measured. Cell metabolic activity, proliferation and alkaline phosphatase (ALP) was measured and cell attachment was determined by quantifying adhesion plaques with cells. ANAB treatment increased the surface hydrophilicity [91.74 ± 4.80° (PEEK) vs. 74.82 ± 2.70° (ANAB PEEK), p PEEK compared to PEEK (p PEEK surfaces. MSCs seeded on ANAB PEEK in the presence of osteogenic media, expressed increased levels of ALP compared to untreated PEEK (p PEEK. ANAB treatment may improve the osteointegration of PEEK implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1438-1446, 2017. © 2016 Wiley Periodicals, Inc.

  13. Computer simulation model of reflex e-beam systems coupled to an external circuit

    International Nuclear Information System (INIS)

    Jungwirth, K.; Stavinoha, P.

    1982-01-01

    Dynamics of ions and relativistic electrons in various high-voltage reflexing systems (reflex diodes and triodes) was investigated numerically by means of 1 1/2-dimensional PIC simulation model OREBIA. Its perfected version OREBIA-REX also accounts for system coupling to an external power source circuit, thus yielding the currents and applied voltage self-consistently. Various modes of operation of reflex diode and triode were studied using both models. It is shown that neglecting the influence of the external circuit can lead to seve--re overestimation of both ion currents and electron accumulation rates. In coupled systems with ions repeated collapses of impedance due to electron-ion relaxation processes are observed. The current and voltage pulses calculated for several reflex diodes and triodes with and without ions are presented. (J.U.)

  14. Optical techniques for electron-beam characterizations on the APS SASE FEL project

    International Nuclear Information System (INIS)

    Lumpkin, A.H.; Yang, B.X.; Berg, W.J.; White, M.; Lewellen, J.W.; Milton, S.V.

    1998-01-01

    At the Advanced Photon Source (APS) the injector linac's DC thermionic gun is being supplemented by a low-emittance rf thermionic gun that will support the SASE FEL project. To address the anticipated smaller beam sizes, the standard Chromox beam-profiling screens are being complemented by optical transition radiation (OTR) and Ce-doped YAG single-crystal converters. Direct comparisons of the effective conversion efficiency, spatial resolution, and time response of the three converter screen types have been performed using the DC thermionic gun's beam accelerated to 400 to 650 MeV. An apparent blurring of observed beam size with increasing incident charge areal density in the YAG crystal was observed for the first time. Only the OTR was prompt enough for the few-ps domain micropulse bunch length measurements performed with a stream camera. Initial beam images of the rf-thermionic gun beam have also been obtained

  15. Shapes of leaves with parallel venation. Modelling of the Epipactis sp. (Orchidaceae) leaves with the help of a system of coupled elastic beams

    OpenAIRE

    Jakubska-Busse, Anna; Janowicz, Maciej; Ochnio, Luiza; Jackowska-Zduniak, Beata

    2016-01-01

    Static properties of leaves with parallel venation, with particular emphasis on the genus EpipactisZinn, 1757 (Orchidaceae, Neottieae) have been modelled with coupled quasi-parallel elastic “beams.” The non-linear theory of strongly bended beams have been employed. The resulting boundary-value problem has been solved numerically with the help of the finite-difference method. Possible dislocations resulting in additional Dirac-delta like forces have been take into account. Morphological simila...

  16. Orthogonal image pairs coupled with OSMS for noncoplanar beam angle, intracranial, single-isocenter, SRS treatments with multiple targets on the Varian Edge radiosurgery system

    Directory of Open Access Journals (Sweden)

    Jasmine A. Oliver, PhD

    2017-07-01

    Conclusion: Based on our study, CR-induced shifts with the Varian Edge radiosurgery system will not produce noticeable dosimetric effects for SRS treatments. Thus, replacing cone beam CT with orthogonal kV/kV pairs coupled with OSMS at the treatment couch angle could reduce the number of cone beam CT scans that are acquired during a standard SRS treatment while providing an accurate and safe treatment with negligible dosimetric effects on the treatment plan.

  17. Spatial Control of Photoemitted Electron Beams using a Micro-Lens-Array Transverse-Shaping Technique

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, A. [Northern Illinois U.; Qiang, G. [Tsinghua U., Beijing, Dept. Eng. Phys.; Ha, G. [POSTECH; Wisniewski, E. [Argonne (main); Piot, P. [NIU, DeKalb; Power, J. G. [Argonne (main); Gai, W. [Argonne (main)

    2017-07-24

    A common issue encountered in photoemission electron sources used in electron accelerators is the transverse inhomogeneity of the laser distribution resulting from the laser-amplification process and often use of frequency up conversion in nonlinear crystals. A inhomogeneous laser distribution on the photocathode produces charged beams with lower beam quality. In this paper, we explore the possible use of microlens arrays (fly-eye light condensers) to dramatically improve the transverse uniformity of the drive laser pulse on UV photocathodes. We also demonstrate the use of such microlens arrays to generate transversely-modulated electron beams and present a possible application to diagnose the properties of a magnetized beam.

  18. Inhibited-coupling HC-PCF based beam-delivery-system for high power green industrial lasers

    Science.gov (United States)

    Chafer, M.; Gorse, A.; Beaudou, B.; Lekiefs, Q.; Maurel, M.; Debord, B.; Gérôme, F.; Benabid, F.

    2018-02-01

    We report on an ultra-low loss Hollow-Core Photonic Crystal Fiber (HC-PCF) beam delivery system (GLO-GreenBDS) for high power ultra-short pulse lasers operating in the green spectral range (including 515 nm and 532 nm). The GLOBDS- Green combines ease-of-use, high laser-coupling efficiency, robustness and industrial compatible cabling. It comprises a pre-aligned laser-injection head, a sheath-cable protected HC-PCF and a modular fiber-output head. It enables fiber-core gas loading and evacuation in a hermetic fashion. A 5 m long GLO-BDS were demonstrated for a green short pulse laser with a transmission coefficient larger than 80%, and a laser output profile close to single-mode (M2 <1.3).

  19. Investigation of chemical vapour deposition diamond detectors by X-ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

    International Nuclear Information System (INIS)

    Olivero, P.; Manfredotti, C.; Vittone, E.; Fizzotti, F.; Paolini, C.; Lo Giudice, A.; Barrett, R.; Tucoulou, R.

    2004-01-01

    Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the large hadron collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of 'detector grade' artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro-beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitative study of the inhomogeneity of the charge transport parameter defined as the product of mobility and lifetime for both electron and holes. XBIL represents a technique complementary to ion beam induced luminescence (IBIL), which has already been used by our group, since X-ray energy loss profile in the material is different from that of MeV ions. X-ray induced luminescence maps have been performed simultaneously with induced photocurrent maps, to correlate charge transport and induced luminescence properties of diamond. Simultaneous XBICC and XBIL maps exhibit features of partial complementarity that have been interpreted on the basis of considerations on radiative and non-radiative recombination processes which compete with charge transport efficiency

  20. Dosimetric characterization of BeO samples in alpha, beta and X radiation beams using luminescent techniques

    International Nuclear Information System (INIS)

    Groppo, Daniela Piai

    2013-01-01

    In the medical field, the ionizing radiation is used both for therapeutic and diagnostic purposes, in a wide range of radiation doses. In order to ensure that the objective is achieved in practice, detailed studies of detectors and devices in different types of radiations beams are necessary. In this work a dosimetric characterization of BeO samples was performed using the techniques of thermoluminescence (TL) and optically stimulated luminescence (OSL) by a comparison of their response for alpha, beta and X radiations and the establishment of an appropriated system for use in monitoring of these radiations beams. The main results are: the high sensitivity to beta radiation for both techniques, good reproducibility of TL and OSL response (coefficients of variation lower than 5%), maximum energy dependence of the X radiation of 28% for the TL technique, and only 7% for the OSL technique, within the studied energy range. The dosimetric characteristics obtained in this work show the possibility of applying BeO samples to dosimetry of alpha, beta and X radiations, considering the studied dose ranges, using the TL and OSL techniques. From the results obtained, the samples of BeO showed their potential use for beam dosimetry in diagnostic radiology and radiotherapy. (author)

  1. Progress in ETA-II magnetic field alignment using stretched wire and low energy electron beam techniques

    International Nuclear Information System (INIS)

    Griffith, L.V.; Deadrick, F.J.

    1991-01-01

    Flux line alignment of the solenoidal focus magnets used on the ETA-II linear induction accelerator is a key element leading to a reduction of beam corkscrew motion. Two techniques have been used on the ETA-II accelerator to measure and establish magnet alignment. A low energy electron beam has been used to directly map magnetic field lines, and recent work has utilized a pulsed stretched wire technique to measure magnet tilts and offsets with respect to a reference axis. This paper reports on the techniques used in the ETA-II accelerator alignment, and presents results from those measurements which show that accelerator is magnetically aligned to within ∼ ± 200 microns

  2. Artificial intelligence techniques coupled with seasonality measures for hydrological regionalization of Q90 under Brazilian conditions

    Science.gov (United States)

    Beskow, Samuel; de Mello, Carlos Rogério; Vargas, Marcelle M.; Corrêa, Leonardo de L.; Caldeira, Tamara L.; Durães, Matheus F.; de Aguiar, Marilton S.

    2016-10-01

    Information on stream flows is essential for water resources management. The stream flow that is equaled or exceeded 90% of the time (Q90) is one the most used low stream flow indicators in many countries, and its determination is made from the frequency analysis of stream flows considering a historical series. However, stream flow gauging network is generally not spatially sufficient to meet the necessary demands of technicians, thus the most plausible alternative is the use of hydrological regionalization. The objective of this study was to couple the artificial intelligence techniques (AI) K-means, Partitioning Around Medoids (PAM), K-harmonic means (KHM), Fuzzy C-means (FCM) and Genetic K-means (GKA), with measures of low stream flow seasonality, for verification of its potential to delineate hydrologically homogeneous regions for the regionalization of Q90. For the performance analysis of the proposed methodology, location attributes from 108 watersheds situated in southern Brazil, and attributes associated with their seasonality of low stream flows were considered in this study. It was concluded that: (i) AI techniques have the potential to delineate hydrologically homogeneous regions in the context of Q90 in the study region, especially the FCM method based on fuzzy logic, and GKA, based on genetic algorithms; (ii) the attributes related to seasonality of low stream flows added important information that increased the accuracy of the grouping; and (iii) the adjusted mathematical models have excellent performance and can be used to estimate Q90 in locations lacking monitoring.

  3. Perpendicular diffusion of a dilute beam of charged dust particles in a strongly coupled dusty plasma

    Science.gov (United States)

    Liu, Bin; Goree, J.

    2014-06-01

    The diffusion of projectiles drifting through a target of strongly coupled dusty plasma is investigated in a simulation. A projectile's drift is driven by a constant force F. We characterize the random walk of the projectiles in the direction perpendicular to their drift. The perpendicular diffusion coefficient Dp⊥ is obtained from the simulation data. The force dependence of Dp⊥ is found to be a power law in a high force regime, but a constant at low forces. A mean kinetic energy Wp for perpendicular motion is also obtained. The diffusion coefficient is found to increase with Wp with a linear trend at higher energies, but an exponential trend at lower energies.

  4. Study of the light emission from hydrogen atoms excited by the beam-foil technique

    International Nuclear Information System (INIS)

    Broll, Norbert.

    1976-01-01

    Zero-field and Stark-induced quantum beat measurements have been performed for beam foil excited hydrogen (H + and H 2 + beam). Experimental evidence of coherent excitation of S and P states of Lyman α line has been demonstrated [fr

  5. An intense lithium ion beam source using vacuum baking and discharge cleaning techniques

    International Nuclear Information System (INIS)

    Moschella, J.J.; Kusse, B.R.; Longfellow, J.P.; Olson, J.C.

    1991-01-01

    We have developed a high-purity, intense, lithium ion beam source which operates at 500 kV and 120 A/cm 2 with pulse widths of 125 ns full width half maximum. The beams were generated using a lithium chloride anode in planar magnetically insulated geometry. We have found that the combination of vacuum baking of the anode at 250 degree C followed by the application of 100 W of pure argon, steady-state, glow discharge cleaning reduced the impurity concentration in the beam to approximately 10% (components other than chlorine or lithium were considered impurities). Although the impurities were low, the concentration of chlorine in the 1+ and 2+ charge states was significant (∼25%). The remaining 65% of the beam consisted of Li + ions. Without the special cleaning process, over half the beam particles were impurities. It was determined that these impurities entered the beam at the anode surface but came originally from material in the vacuum chamber. After the cleaning process, recontamination was observed to occur in approximately 6 min. This long recontamination time, which was much greater than the expected monolayer formation time, was attributed to the elevated temperature of the anode. We also compared the electrical characteristics of the beams produced by LiCl anodes to those generated by a standard polyethylene proton source. In contrast to the polyethylene anode, the LiCl source exhibited a higher impedance, produced beams of lower ion current efficiency and had longer turn on times

  6. Five second helium neutral beam injection using argon-frost cryopumping techniques

    International Nuclear Information System (INIS)

    Phillips, J.C.; Kellman, D.H.; Hong, R.; Kim, J.; Laughon, G.M.

    1995-01-01

    High power helium neutral beams for the heating of tokamak discharges can now be provided for 5 s by using argon cryopumping (of the helium gas) in the beamlines. The DIII-D neutral beam system has routinely provided up to 20 MW of deuterium neutral beam heating in support of experiments on the DIII-D tokamak. Operation of neutral beams with helium has historically presented a problem in that pulse lengths have been limited to 500 ms due to reliance solely on volume pumping of the helium gas. Helium is not condensed on the cryopanels. A system has now been installed to deposit a layer of argon frost on the DIII-D neutral beam cryopanels, between tokamak injection pulses. The layer serves to trap helium on the cryopanels providing sufficient pumping speed for 5 s helium beam extraction. The argon frosting hardware is now present on two of four DIII-D neutral beamlines, allowing injection of up to 6 MW of helium neutral beams per discharge, with pulse lengths of up to 5 s. The argon frosting system is described, along with experimental results demonstrating its effectiveness as a method of economically extending the capabilities of cryogenic pumping panels to allow multi-second helium neutral beam injection

  7. Five second helium neutral beam injection using argon-frost cryopumping techniques

    International Nuclear Information System (INIS)

    Phillips, J.C.; Kellman, D.H.; Hong, R.; Kim, J.; Laughon, G.M.

    1995-10-01

    High power helium neutral beams for the heating of tokamak discharges can now be provided for 5 s by using argon cryopumping (of the helium gas) in the beamlines. A system has now been installed to deposit a layer of argon frost on the DIII-D neutral beam cryopanels, between tokamak injection pulses. The layer serves to trap helium on the cryopanels providing sufficient pumping speed for 5 s helium beam extraction. The argon frosting hardware is now present on two of four DIII-D neutral beamlines, allowing injection of up to 6 MW of helium neutral beams per discharge, with pulse lengths of up to 5 s. The argon frosting system is described, along with experimental results demonstrating its effectiveness as a method of economically extending the capabilities of cryogenic pumping panels to allow multi-second helium neutral beam injection

  8. A coupled analysis of fluid flow, heat transfer and deformation behavior of solidifying shell in continuously cast beam blank

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Eui; Yeo, Tae Jung; Oh, Kyu Hwan; Yoon, Jong Kyu [School of Materials Science and Engineering, Seoul Nat` l Univ., Seoul (Korea, Republic of); Han, Heung Nam [Oxford Center for Advanced Materials and Composites, Department of Materials, Univ. of Oxford (United Kingdom)

    1998-12-31

    A mathematical model for a coupled analysis of fluid flow, heat transfer and deformation behavior in the continuously cast beam blank has been developed. The fluid flow, heat transfer and solidification in the mold region were analyzed with 3-dimensional finite difference method (FDM) based on control volume method. A body fitted coordinate system was introduced for the complex geometry of the beam blank. The effects of turbulence and natural convection of molten steel were taken into account in determining the fluid flow in the strand. The thermo-elasto-plastic deformation behavior in the cast strand and the formation of air gap between the solidifying shell and the mold were analyzed by the finite element method (FEM) using the 2-dimensional slice temperature profile calculated by the FDM. The heat flow between the strand and the mold was evaluated by the coupled analysis between the fluid flow-heat transfer analysis and the thermo-elasto-plastic stress analysis. In order to determine the solid fraction in the mushy zone, the microsegregation of solute element was assessed. The effects of fluid flow on the heat transfer, the solidification of steel and the distribution of shell thickness during the casting of the beam blank were simulated. The deformation behavior of the solidifying shell and the possibility of cracking of the strand were also investigated. The recirculating flows were developed in the regions of the web and the flange tip. The impinging of the inlet flow from the nozzle retarded the growing of solidifying shell in the regions of the fillet and the flange. The air gap between the strand and the mold was formed near the region of the corner of the flange tip. At the initial stage of casting, the probability of the surface cracking was high in the regions of the fillet and the flange tip. After the middle stage of casting, the internal cracking was predicted in the regions of the flange tip, and between the fillet and the flange tip. (author) 38

  9. A coupled analysis of fluid flow, heat transfer and deformation behavior of solidifying shell in continuously cast beam blank

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Eui; Yeo, Tae Jung; Oh, Kyu Hwan; Yoon, Jong Kyu [School of Materials Science and Engineering, Seoul Nat`l Univ., Seoul (Korea, Republic of); Han, Heung Nam [Oxford Center for Advanced Materials and Composites, Department of Materials, Univ. of Oxford (United Kingdom)

    1997-12-31

    A mathematical model for a coupled analysis of fluid flow, heat transfer and deformation behavior in the continuously cast beam blank has been developed. The fluid flow, heat transfer and solidification in the mold region were analyzed with 3-dimensional finite difference method (FDM) based on control volume method. A body fitted coordinate system was introduced for the complex geometry of the beam blank. The effects of turbulence and natural convection of molten steel were taken into account in determining the fluid flow in the strand. The thermo-elasto-plastic deformation behavior in the cast strand and the formation of air gap between the solidifying shell and the mold were analyzed by the finite element method (FEM) using the 2-dimensional slice temperature profile calculated by the FDM. The heat flow between the strand and the mold was evaluated by the coupled analysis between the fluid flow-heat transfer analysis and the thermo-elasto-plastic stress analysis. In order to determine the solid fraction in the mushy zone, the microsegregation of solute element was assessed. The effects of fluid flow on the heat transfer, the solidification of steel and the distribution of shell thickness during the casting of the beam blank were simulated. The deformation behavior of the solidifying shell and the possibility of cracking of the strand were also investigated. The recirculating flows were developed in the regions of the web and the flange tip. The impinging of the inlet flow from the nozzle retarded the growing of solidifying shell in the regions of the fillet and the flange. The air gap between the strand and the mold was formed near the region of the corner of the flange tip. At the initial stage of casting, the probability of the surface cracking was high in the regions of the fillet and the flange tip. After the middle stage of casting, the internal cracking was predicted in the regions of the flange tip, and between the fillet and the flange tip. (author) 38

  10. Modification of PTFE nanopowder by controlled electron beam irradiation: A useful approach for the development of PTFE coupled EPDM compounds

    Directory of Open Access Journals (Sweden)

    2008-04-01

    Full Text Available Low-temperature reactive mixing of controlled electron beam modified Polytetrafluoroethylene (PTFE nanopowder with Ethylene-Propylene-Diene-Monomer (EPDM rubber produced PTFE coupled EPDM rubber compounds with desired physical properties. The radiation-induced chemical alterations in PTFE nanopowder, determined by electron spin resonance (ESR and Fourier transform infrared (FTIR spectroscopy, showed increasing concentration of radicals and carboxylic groups (–COOH with increasing irradiation dose. The morphological variations of the PTFE nanopowder including its decreasing mean agglomerate size with the absorbed dose was investigated by particle size and scanning electron microscopy (SEM analysis. With increasing absorbed dose the wettability of the modified PTFE nanopowder determined by contact angle method increased in accordance with the (–COOH concentration. Transmission electron microscopy (TEM showed that modified PTFE nanopowder is obviously enwrapped by EPDM. This leads to a characteristic compatible interphase around the modified PTFE. Crystallization studies by differential scanning calorimetry (DSC also revealed the existence of a compatible interphase in the modified PTFE coupled EPDM.

  11. Formation of scandium nitride (ScN) layer on gallium arsenide (GaAs) substrate using a combined technique of e-beam evaporator and ammonia annealing treatment

    International Nuclear Information System (INIS)

    Yong Shee Meng, Alvin; Zainal, Norzaini; Hassan, Zainuriah; Ibrahim, Kamarulazizi

    2015-01-01

    Graphical abstract: - Highlights: • Forming ScN layer using electron e-beam evaporator with successive NH_3 annealing thermal has been successfully demonstrated. • NH_3 annealing played the role in changing the grain structure of the ScN layer. • The existence of Sc−N bonds was confirmed by XPS measurement. • The 900 °C annealed ScN layer showed the best structural and optical characteristics. • ScN layer annealed at 980 °C exhibited poor structural and optical characteristics. - Abstract: A demonstration on a new technique of growing ScN using electron beam (e-beam) evaporator, coupled with successive ammonia (NH_3) annealing treatment is presented in this paper. The annealing temperature was varied at 750, 800, 850, 900 and 980 °C in order to obtain the best ScN layer. It was found that as the annealing temperature increased, the surface morphology of the ScN layer changed and ScN grains formed abundantly on the surface. The best surface of ScN layer was found in the 900 °C annealed sample. However, the roughness of the ScN increased with temperature. The photoluminescence (PL) peak of the near-to-band-edge (NBE) of ScN was observable in all samples and its intensity was the highest in the 900 °C annealed sample. Note that when the annealing treatment was conducted at 980 °C, the GaN PL peak is observable. Raman peaks of TO(X) of ScN were much evident at the annealing temperature above 900 °C. The formation of Sc−N bonds was confirmed by X-ray spectroscopy (XPS) measurement. In the end of this work, we propose that the formation of ScN using the above techniques was successful, with thermal annealing at the temperature of 900 °C.

  12. Congestive heart failure, spouses' support and the couple's sleep situation: a critical incident technique analysis.

    Science.gov (United States)

    Broström, Anders; Strömberg, Anna; Dahlström, Ulf; Fridlund, Bengt

    2003-03-01

    Sleep related breathing disorders are common as well as a poor prognostic sign associated with higher mortality in patients with congestive heart failure (CHF). These patients often have a shorter total duration of sleep, disturbed sleep structure and increased daytime sleepiness, which can negatively affect all dimensions of the life situation. The spouse has an important role in supporting the patient in relation to sleep disorders, but this role may be adversely affected by the sleep situation of the couple. The aim of this study was to describe decisive situations that influence spouses' support to patients with CHF in relation to the couple's sleep situation. A qualitative descriptive design using critical incident technique was employed. Incidents were collected by means of interviews with 25 spouses of patients with CHF, strategically selected from two hospital-based specialist clinics in southern Sweden. Two main areas emerged in the analysis: support stimulating situations and support inhibiting situations. Support stimulating situations described how spouses' support was positively affected by their own adaptation in psychosocial or practical situations, and receiving help from others. Support inhibiting situations described how the spouses' support was negatively affected by sleep disturbances as a result of the patient's symptoms, anxiety in relation to the disease, limitations as a result of the sleeping habits, dissatisfaction with care related to the sleep situation, and being left to cope alone with the problems. An increased understanding of the stimulating and inhibiting situations influencing spouses' support for patients with CHF can guide health care personnel in deciding if an intervention is needed to improve the sleep situation for patient and spouse.

  13. Discriminating Z' from anomalous trilinear gauge coupling signatures in e+e-→W+W- at ILC with polarized beams

    International Nuclear Information System (INIS)

    Andreev, V.V.; Moortgat-Pick, G.; Osland, P.; Pankov, A.A.; Paver, N.

    2012-01-01

    New heavy neutral gauge bosons Z' are predicted by many models of physics beyond the Standard Model. It is quite possible that Z's are heavy enough to lie beyond the discovery reach of the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z' exchanges may emerge at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We discuss in this context the foreseeable sensitivity to Z's of W ± -pair production cross sections at the e + e - International Linear Collider (ILC), especially as regards the potential of distinguishing observable effects of the Z' from analogous ones due to competitor models with anomalous trilinear gauge couplings (AGC) that can lead to the same or similar new physics experimental signatures at the ILC. The sensitivity of the ILC for probing the Z-Z' mixing and its capability to distinguish these two new physics scenarios is substantially enhanced when the polarization of the initial beams and the produced W ± bosons are considered. A model-independent analysis of the Z' effects in the process e + e - →W + W - allows to differentiate the full class of vector Z' models from those with anomalous trilinear gauge couplings, with one notable exception: the sequential SM (SSM)-like models can in this process not be distinguished from anomalous gauge couplings. Results of model-dependent analysis of a specific Z' are expressed in terms of discovery and identification reaches on the Z-Z' mixing angle and the Z' mass. (orig.)

  14. Size constraints on a Majorana beam-splitter interferometer: Majorana coupling and surface-bulk scattering

    Science.gov (United States)

    Røising, Henrik Schou; Simon, Steven H.

    2018-03-01

    Topological insulator surfaces in proximity to superconductors have been proposed as a way to produce Majorana fermions in condensed matter physics. One of the simplest proposed experiments with such a system is Majorana interferometry. Here we consider two possibly conflicting constraints on the size of such an interferometer. Coupling of a Majorana mode from the edge (the arms) of the interferometer to vortices in the center of the device sets a lower bound on the size of the device. On the other hand, scattering to the usually imperfectly insulating bulk sets an upper bound. From estimates of experimental parameters, we find that typical samples may have no size window in which the Majorana interferometer can operate, implying that a new generation of more highly insulating samples must be explored.

  15. Monte Carlo simulation for scanning technique with scattering foil free electron beam: A proof of concept study.

    Directory of Open Access Journals (Sweden)

    Wonmo Sung

    Full Text Available This study investigated the potential of a newly proposed scattering foil free (SFF electron beam scanning technique for the treatment of skin cancer on the irregular patient surfaces using Monte Carlo (MC simulation. After benchmarking of the MC simulations, we removed the scattering foil to generate SFF electron beams. Cylindrical and spherical phantoms with 1 cm boluses were generated and the target volume was defined from the surface to 5 mm depth. The SFF scanning technique with 6 MeV electrons was simulated using those phantoms. For comparison, volumetric modulated arc therapy (VMAT plans were also generated with two full arcs and 6 MV photon beams. When the scanning resolution resulted in a larger separation between beams than the field size, the plan qualities were worsened. In the cylindrical phantom with a radius of 10 cm, the conformity indices, homogeneity indices and body mean doses of the SFF plans (scanning resolution = 1° vs. VMAT plans were 1.04 vs. 1.54, 1.10 vs. 1.12 and 5 Gy vs. 14 Gy, respectively. Those of the spherical phantom were 1.04 vs. 1.83, 1.08 vs. 1.09 and 7 Gy vs. 26 Gy, respectively. The proposed SFF plans showed superior dose distributions compared to the VMAT plans.

  16. Monte Carlo simulation for scanning technique with scattering foil free electron beam: A proof of concept study.

    Science.gov (United States)

    Sung, Wonmo; Park, Jong In; Kim, Jung-In; Carlson, Joel; Ye, Sung-Joon; Park, Jong Min

    2017-01-01

    This study investigated the potential of a newly proposed scattering foil free (SFF) electron beam scanning technique for the treatment of skin cancer on the irregular patient surfaces using Monte Carlo (MC) simulation. After benchmarking of the MC simulations, we removed the scattering foil to generate SFF electron beams. Cylindrical and spherical phantoms with 1 cm boluses were generated and the target volume was defined from the surface to 5 mm depth. The SFF scanning technique with 6 MeV electrons was simulated using those phantoms. For comparison, volumetric modulated arc therapy (VMAT) plans were also generated with two full arcs and 6 MV photon beams. When the scanning resolution resulted in a larger separation between beams than the field size, the plan qualities were worsened. In the cylindrical phantom with a radius of 10 cm, the conformity indices, homogeneity indices and body mean doses of the SFF plans (scanning resolution = 1°) vs. VMAT plans were 1.04 vs. 1.54, 1.10 vs. 1.12 and 5 Gy vs. 14 Gy, respectively. Those of the spherical phantom were 1.04 vs. 1.83, 1.08 vs. 1.09 and 7 Gy vs. 26 Gy, respectively. The proposed SFF plans showed superior dose distributions compared to the VMAT plans.

  17. Technique using axicons for generating flat-top laser-beam profiles

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Woodfin, G.L.; Stahl, D.; Carpenter, J.P.; Kyrala, G.

    1983-01-01

    In certain fusion experiments using CO 2 lasers, like Helios, it is desired to produce a focal spot several times larger than the nominal focal spot, with a flat beam profile. The typical focal spot in Helios is roughly 70 μm and just defocussing the beam produces beam breakup, with several hot spots with roughly the original diameter, and a gaussian distribution. A number of schemes were tried to achieve a large spot with desired characteristics. These are described in the article. Axicons were found to produce spots with desired characteristics. Axicons are lenses or mirrors having a cone-shaped surface. The various schemes are described, as well as an experiment in Helios which confirmed that axicons produced the spots with desirable characteristics. Helios is an 8-beam CO 2 laser which produces 10 kJ at power in excess of 20 TW. It is currently being used for Laser Fusion studies at the Los Alamos National Laboratory

  18. Novel imaging and quality assurance techniques for ion beam therapy a Monte Carlo study

    CERN Document Server

    Rinaldi, I; Jäkel, O; Mairani, A; Parodi, K

    2010-01-01

    Ion beams exhibit a finite and well defined range in matter together with an “inverted” depth-dose profile, the so-called Bragg peak. These favourable physical properties may enable superior tumour-dose conformality for high precision radiation therapy. On the other hand, they introduce the issue of sensitivity to range uncertainties in ion beam therapy. Although these uncertainties are typically taken into account when planning the treatment, correct delivery of the intended ion beam range has to be assured to prevent undesired underdosage of the tumour or overdosage of critical structures outside the target volume. Therefore, it is necessary to define dedicated Quality Assurance procedures to enable in-vivo range verification before or during therapeutic irradiation. For these purposes, Monte Carlo transport codes are very useful tools to support the development of novel imaging modalities for ion beam therapy. In the present work, we present calculations performed with the FLUKA Monte Carlo code and pr...

  19. Design technique for all-dielectric non-polarizing beam splitter plate

    Science.gov (United States)

    Rizea, A.

    2012-03-01

    There are many situations when, for the proper working, an opto-electronic device requiring optical components does not change the polarization state of light after a reflection, splitting or filtering. In this paper, a design for a non-polarizing beam splitter plate is proposed. Based on certain optical properties of homogeneous dielectric materials we will establish a reliable thin film package formula, excellent for the start of optimization to obtain a 20-nm bandwidth non-polarizing beam splitter.

  20. Reliability techniques and Coupled BEM/FEM for interaction pile-soil

    Directory of Open Access Journals (Sweden)

    Ahmed SAHLI

    2017-06-01

    Full Text Available This paper deals with the development of a computational code for the modelling and verification of safety in relation to limit states of piles found in foundations of current structures. To this end, it makes use of reliability techniques for the probabilistic analysis of piles modelled with the finite element method (FEM coupled to the boundary element method (BEM. The soil is modelled with the BEM employing Mindlin's fundamental solutions, suitable for the consideration of a three-dimensional infinite half-space. The piles are modelled as bar elements with the MEF, each of which is represented in the BEM as a loading line. The finite element of the employed bar has four nodes and fourteen nodal parameters, three of which are displacements for each node plus two rotations for the top node. The slipping of the piles in relation to the mass is carried out using adhesion models to define the evolution of the shaft tensions during the transfer of load to the soil. The reliability analysis is based on three methods: first order second moment (FOSM, first order reliability method and Monte Carlo method.

  1. The coupling technique: A two-wave acoustic method for the study of dislocation dynamics

    Science.gov (United States)

    Gremaud, G.; Bujard, M.; Benoit, W.

    1987-03-01

    Progress in the study of dislocation dynamics has been achieved using a two-wave acoustic method, which has been called the coupling technique. In this method, the attenuation α and the velocity v of ultrasonic waves are measured in a sample submitted simultaneously to a harmonic stress σ of low frequency. Closed curves Δα(σ) and Δv/v(σ) are drawn during each cycle of the applied stress. The shapes of these curves and their evolution are characteristic of each dislocation motion mechanism which is activated by the low-frequency applied stress. For this reason, the closed curves Δα(σ) and Δv/v(σ) can be considered as signatures of the interaction mechanism which controls the low-frequency dislocation motion. In this paper, the concept of signature is presented and explained with some experimental examples. It will also be shown that theoretical models can be developed which explain very well the experimental results.

  2. Calculation of light delay for coupled microrings by FDTD technique and Padé approximation.

    Science.gov (United States)

    Huang, Yong-Zhen; Yang, Yue-De

    2009-11-01

    The Padé approximation with Baker's algorithm is compared with the least-squares Prony method and the generalized pencil-of-functions (GPOF) method for calculating mode frequencies and mode Q factors for coupled optical microdisks by FDTD technique. Comparisons of intensity spectra and the corresponding mode frequencies and Q factors show that the Padé approximation can yield more stable results than the Prony and the GPOF methods, especially the intensity spectrum. The results of the Prony method and the GPOF method are greatly influenced by the selected number of resonant modes, which need to be optimized during the data processing, in addition to the length of the time response signal. Furthermore, the Padé approximation is applied to calculate light delay for embedded microring resonators from complex transmission spectra obtained by the Padé approximation from a FDTD output. The Prony and the GPOF methods cannot be applied to calculate the transmission spectra, because the transmission signal obtained by the FDTD simulation cannot be expressed as a sum of damped complex exponentials.

  3. Composition and stratigraphy of the paint layers: investigation on the Madonna dei Fusi by ion beam analysis techniques

    Science.gov (United States)

    Grassi, N.

    2005-06-01

    In the framework of the extensive study on the wood painting "Madonna dei fusi" attributed to Leonardo da Vinci, Ion Beam Analysis (IBA) techniques were used at the Florence accelerator laboratory to get information about the elemental composition of the paint layers. After a brief description of the basic principle and the general features of IBA techniques, we will illustrate in detail how the analysis allowed us to characterise the pigments of original and restored areas and the substrate composition, and to obtain information about the stratigraphy of the painting, also providing an estimate of the paint layer thickness.

  4. Determination of boron in aqueous solutions by solid state nuclear track detectors technique, using a filtered neutron beam

    International Nuclear Information System (INIS)

    Moraes, M.A.P.V. de; Pugliesi, R.; Khouri, M.T.F.C.

    1985-11-01

    The solid state nuclear track detectors technique has been used for determination of boron in aqueous solutions, using a filtered neutron beam. The particles tracks from the 10 B(n,α)Li 7 reaction were registered in the CR-39 film, chemically etched in a (30%) KOH solution 70 0 C during 90 minutes. The obtained results showed the usefulness of this technique for boron determination in the ppm range. The inferior detectable limit was 9 ppm. The combined track registration efficiency factor K has been evaluated in the solutions, for the CR-39 detector and its values is K= (4,60 - + 0,06). 10 -4 cm. (Author) [pt

  5. Transmission and group-delay characterization of coupled resonator optical waveguides apodized through the longitudinal offset technique.

    Science.gov (United States)

    Doménech, J D; Muñoz, P; Capmany, J

    2011-01-15

    In this Letter, the amplitude and group delay characteristics of coupled resonator optical waveguides apodized through the longitudinal offset technique are presented. The devices have been fabricated in silicon-on-insulator technology employing deep ultraviolet lithography. The structures analyzed consisted of three racetracks resonators uniform (nonapodized) and apodized with the aforementioned technique, showing a delay of 5 ± 3 ps and 4 ± 0.5 ps over 1.6 and 1.4 nm bandwidths, respectively.

  6. Accurate technique for complete geometric calibration of cone-beam computed tomography systems

    International Nuclear Information System (INIS)

    Cho Youngbin; Moseley, Douglas J.; Siewerdsen, Jeffrey H.; Jaffray, David A.

    2005-01-01

    Cone-beam computed tomography systems have been developed to provide in situ imaging for the purpose of guiding radiation therapy. Clinical systems have been constructed using this approach, a clinical linear accelerator (Elekta Synergy RP) and an iso-centric C-arm. Geometric calibration involves the estimation of a set of parameters that describes the geometry of such systems, and is essential for accurate image reconstruction. We have developed a general analytic algorithm and corresponding calibration phantom for estimating these geometric parameters in cone-beam computed tomography (CT) systems. The performance of the calibration algorithm is evaluated and its application is discussed. The algorithm makes use of a calibration phantom to estimate the geometric parameters of the system. The phantom consists of 24 steel ball bearings (BBs) in a known geometry. Twelve BBs are spaced evenly at 30 deg in two plane-parallel circles separated by a given distance along the tube axis. The detector (e.g., a flat panel detector) is assumed to have no spatial distortion. The method estimates geometric parameters including the position of the x-ray source, position, and rotation of the detector, and gantry angle, and can describe complex source-detector trajectories. The accuracy and sensitivity of the calibration algorithm was analyzed. The calibration algorithm estimates geometric parameters in a high level of accuracy such that the quality of CT reconstruction is not degraded by the error of estimation. Sensitivity analysis shows uncertainty of 0.01 deg. (around beam direction) to 0.3 deg. (normal to the beam direction) in rotation, and 0.2 mm (orthogonal to the beam direction) to 4.9 mm (beam direction) in position for the medical linear accelerator geometry. Experimental measurements using a laboratory bench Cone-beam CT system of known geometry demonstrate the sensitivity of the method in detecting small changes in the imaging geometry with an uncertainty of 0.1 mm in

  7. Influence of external beam technique and brachytherapy quality assurance on the side effects in the combined external beam- and brachytherapy treatment of local advanced prostate cancer

    International Nuclear Information System (INIS)

    Kovacs, G.; Galalae, R.; Wirth, B.; Bertermann, H.; Wilhelm, R.; Kohr, P.; Kimmig, B.

    1996-01-01

    Transrectal ultrasound(TRUS) guided HDR implantation of the prostate has been established at the Kiel University by Bertermann and Brix in 1986 and there are to date 179 (T1b-T3 No Mo) patients treated in a combined modality. The dose for the implant was 2x 15 Gy on the capsule of the prostate in 14-20 days. For local and regional lymph nodes 20 Gy external beam therapy (AP-PA pelvic portals), 20 Gy with an individual transmission block (100% for subclinical disease, 70% and 50% according to the implant dosimetry for the prostate) and 10 Gy small volume irradiation for the prostate was applied, conventional fractioned. Total dose after the therapy 70 Gy for the prostate and 50 Gy for the subclinical disease in 6-7 weeks. As a quality control method we use since 1991 in vivo dosimetry on the medial rectum wall as well as in the prostatic part of the urethra. Regular follow-up 3-118 months after therapy (median 55) with PSA, digital rectal examination, control TRUS with volumetry (after one year with biopsy) and bone scan. There were no major early side effects within the first three months. Proctitis till 1991 with a duration up to 12 months 49%, prolonging more than one year in 23 %, (total proctitis 72.6%). Dysuria in up to 12 months 30 %, long lasting 30% (total number of dysuria 60 %). Erectile dysfunction in 56 %. Because of the number of the side effects 1991 we changed the external beam technique: instead of the biaxial arch therapy the AP-PA portals, and reduced irradiated volume (from 6480 cm 3 to 5040 cm 3 ). We introduced instead of the small volume arch therapy for 10 Gy external boost the box-technique with shielding the back part of the rectum and the upper part of the bladder resulting additional volume reduction. Through the 15 Gy HDR brachytherapy dose on the prostate capsule there are up to 8 Gy on the medial rectal wall, measured by in vivo dosimetry. This dose could not be responsible for the high number of side effects (see gynecological

  8. Exploring the Spatial Resolution of the Photothermal Beam Deflection Technique in the Infrared Region

    CERN Document Server

    Seidel, Wolfgang

    2004-01-01

    In photothermal beam deflection spectroscopy (PTBD) generating and detection of thermal waves occur generally in the sub-millimeter length scale. Therefore, PTBD provides spatial information about the surface of the sample and permits imaging and/or microspectrometry. Recent results of PTBD experiments are presented with a high spatial resolution which is near the diffraction limit of the infrared pump beam (CLIO-FEL). We investigated germanium substrates showing restricted O+-doped regions with an infrared absorption line at a wavelength around 11.6 microns. The spatial resolution was obtained by strongly focusing the probe beam (i.e. a HeNe laser) on a sufficiently small spot. The strong divergence makes it necessary to refocus the probe beam in front of the position detector. The influence of the focusing elements on spatial resolution and signal-to-noise ratio is discussed. In future studies we expect an enhanced spatial resolution due to an extreme focusing of the probe beam leading to a highly sensitive...

  9. Initial Imaging of 7-GeV Electron Beams with OTR/ODR Techniques at APS

    CERN Document Server

    Lumpkin, Alex H; Sereno, Nicholas S; Yao, Chihyuan

    2005-01-01

    The development of nonintercepting (NI) diagnostics continues to be of interest at the Advanced Photon Source (APS) as well as elsewhere. In the three rings of the APS facility we use optical synchrotron radiation generated as the electron beam transits the dipole magnetic fields as an NI mechanism to image the beam during top-up operations. However, in the straight transport lines an alternative method is needed. Optical diffraction radiation (ODR) is under investigation to monitor 7-GeV beam trajectory and potentially transverse shape in the booster-to-storage ring (BTS) beamline during top-up operations. We have performed our initial measurements with an Al blade/mirror that served as an optical transition radiation (OTR) monitor when fully inserted into the beam and as an ODR monitor when the beam passed near the edge. In the case of ODR, appreciable signal is emitted by the metal when gamma times the reduced ODR wavelength is comparable to the impact parameter, where gamma is the Lorentz factor. Visible ...

  10. A layer correlation technique for pion energy calibration at the 2004 ATLAS Combined Beam Test

    International Nuclear Information System (INIS)

    Abat, E; Arik, E; Abdallah, J M; Addy, T N; Adragna, P; Aharrouche, M; Ahmad, A; Akesson, T P A; Aleksa, M; Anghinolfi, F; Baron, S; Alexa, C; Anderson, K; Andreazza, A; Banfi, D; Antonaki, A; Arabidze, G; Atkinson, T; Baines, J; Baker, O K

    2011-01-01

    A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of energy deposits in the calorimeter layers, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Geant4 Monte Carlo events and used to reconstruct the energy of pions impinging on the calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. For pion beams with energies between 20GeV and 180GeV, the particle energy is reconstructed within 3% and the energy resolution is improved by between 11% and 25% compared to the resolution at the electromagnetic scale.

  11. A layer correlation technique for pion energy calibration at the 2004 ATLAS Combined Beam Test

    Energy Technology Data Exchange (ETDEWEB)

    Abat, E; Arik, E [Bogazici University, Faculty of Sciences, Department of Physics, TR - 80815 Bebek-Istanbul (Turkey); Abdallah, J M [Institut de Fisica d' Altes Energies, IFAE, Universitat Autonoma de Barcelona, Edifici Cn, ES - 08193 Bellaterra (Barcelona) Spain (Spain); Addy, T N [Hampton University, Department of Physics, Hampton, VA 23668 (United States); Adragna, P [Queen Mary, University of London, Mile End Road, E1 4NS, London (United Kingdom); Aharrouche, M [Universitaet Mainz, Institut fuer Physik, Staudinger Weg 7, DE 55099 (Germany); Ahmad, A [Insitute of Physics, Academia Sinica, TW - Taipei 11529, Taiwan (China); Akesson, T P A [Lunds universitet, Naturvetenskapliga fakulteten, Fysiska institutionen, Box 118, SE - 221 00, Lund (Sweden); Aleksa, M; Anghinolfi, F; Baron, S [European Laboratory for Particle Physics CERN, CH-1211 Geneva 23 (Switzerland); Alexa, C [National Institute of Physics and Nuclear Engineering (Bucharest -IFIN-HH), P.O. Box MG-6, R-077125 Bucharest (Romania); Anderson, K [University of Chicago, Enrico Fermi Institute, 5640 S. Ellis Avenue, Chicago, IL 60637 (United States); Andreazza, A; Banfi, D [INFN Sezione di Milano, via Celoria 16, IT - 20133 Milano (Italy); Antonaki, A; Arabidze, G [University of Athens, Nuclear and Particle Physics Department of Physics, Panepistimiopouli Zografou, GR 15771 Athens (Greece); Atkinson, T [School of Physics, University of Melbourne, AU - Parkvill, Victoria 3010 (Australia); Baines, J [Rutherford Appleton Laboratory, Science and Technology Facilities Council, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Baker, O K, E-mail: kjg@particle.kth.se [Yale University, Department of Physics , PO Box 208121, New Haven, CT06520-8121 (United States)

    2011-06-15

    A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of energy deposits in the calorimeter layers, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Geant4 Monte Carlo events and used to reconstruct the energy of pions impinging on the calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. For pion beams with energies between 20GeV and 180GeV, the particle energy is reconstructed within 3% and the energy resolution is improved by between 11% and 25% compared to the resolution at the electromagnetic scale.

  12. Contribution of the Acoustic Emission technique in the understanding and the modelling of the coupling between creep and damage in concrete

    International Nuclear Information System (INIS)

    Saliba, J.

    2012-01-01

    In order to design reliable concrete structures, prediction of long term behaviour of concrete is important. In fact, creep deformation can cause mechanical deterioration and cracking, stress redistribution, loss in prestressed members and rarely ruin the structure. The aim of this research is to have a better understanding of the interaction between creep and crack growth in concrete. An experimental investigation on the fracture properties of concrete beams submitted to creep bending tests with high levels of sustained load is reported. The influence of creep on residual capacity and fracture energy of concrete is studied. In parallel, the acoustic emission technique (AE) was used to monitor crack development. The results give wealth information on damage evolution and show a decrease in the width of the fracture process zone (FPZ) characterizing a more brittle behaviour for beams subjected to creep. The AE shows that this may be due to the development of microcracking detected under creep. Based on those experimental results, a mesoscopic numerical study was proposed by coupling a damage model based on the micro-plan theory and a viscoelastic creep model defined by several Kelvin-voigt chains. The numerical results on concrete specimens in tension and in bending confirm the development of microcracks during creep at the mortar-aggregate interface. (author)

  13. Ionizing radiation effects in Acai oil analysed by gas chromatography coupled to mass spectrometry technique

    International Nuclear Information System (INIS)

    Valli, Felipe; Fernandes, Carlos Eduardo; Moura, Sergio; Machado, Ana Carolina; Furasawa, Helio Akira; Pires, Maria Aparecida Faustino; Bustillos, Oscar Vega

    2007-01-01

    The Acai fruit is a well know Brazilian seed plant used in large scale as a source of feed stock, specially in the Brazilian North-east region. The Acai oil is use in many purposes from fuel sources to medicine. The scope of this paper is to analyzed the chemical structures modification of the acai oil after the ionizing radiation. The radiation were set in the range of 10 to 25 kGy in the extracted Acai oil. The analyses were made by gas chromatography coupled to mass spectrometry techniques. A GC/MS Shimatzu QP-5000 equipped with 30 meters DB-5 capillary column with internal diameter of 0.25 mm and 0.25 μm film thickness was used. Helium was used as carried gas and gave a column head pressure of 12 p.s.i. (1 p.s.i. = 6894.76 Pa) and an average flux of 1 ml/min. The temperature program for the GC column consisted of a 4-minutes hold at 75 deg C, a 15 deg C /min ramp to 200 deg C, 8 minutes isothermal. 20 deg C/min ramp to 250 deg C, 2 minutes isothermal. The extraction of the fatty acids was based on liquid-liquid method using chloroform as solvent. The chromatograms resulted shows the presences of the oleic acid and others fatty acids identify by the mass spectra library (NIST-92). The ionization radiation deplete the fatty acids presents in the Acai oil. Details on the chemical qualitative analytical is present as well in this work. (author)

  14. Beam loading

    OpenAIRE

    Boussard, Daniel

    1987-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superco...

  15. High-current electron beam coupling to hybrid waveguide and plasma modes in a dielectric Cherenkov maser with a plasma layer

    International Nuclear Information System (INIS)

    Shlapakovski, Anatoli S.

    2002-01-01

    The linear theory of a dielectric Cherenkov maser with a plasma layer has been developed. The dispersion relation has been derived for the model of infinitely thin, fully magnetized, monoenergetic hollow electron beam, in the axisymmetric case. The results of the numerical solution of the dispersion relation and the analysis of the beam coupling to hybrid waves, both hybrid waveguide and hybrid plasma modes, are presented. For the hybrid waveguide mode, spatial growth rate dependences on frequency at different plasma densities demonstrate improvement in gain for moderate densities, but strong shifting the amplification band and narrowing the bandwidth. For the hybrid plasma mode, the case of mildly relativistic, 200-250 keV beams is of interest, so that the wave phase velocity is just slightly greater than the speed of light in a dielectric medium. It has been shown that depending on beam and plasma parameters, the hybrid plasma mode can be separated from the hybrid waveguide mode, or be coupled to it through the beam resulting in strong gain increase, or exhibit a flat gain vs frequency dependence over a very broad band. The parameters, at which the -3 dB bandwidth calculated for 30 dB peak gain exceeds an octave, have been found

  16. A Multi-Model Reduction Technique for Optimization of Coupled Structural-Acoustic Problems

    DEFF Research Database (Denmark)

    Creixell Mediante, Ester; Jensen, Jakob Søndergaard; Brunskog, Jonas

    2016-01-01

    Finite Element models of structural-acoustic coupled systems can become very large for complex structures with multiple connected parts. Optimization of the performance of the structure based on harmonic analysis of the system requires solving the coupled problem iteratively and for several frequ....... Several methods are compared in terms of accuracy and size of the reduced systems for optimization of simple models....

  17. Combustion Chemistry of Fuels: Quantitative Speciation Data Obtained from an Atmospheric High-temperature Flow Reactor with Coupled Molecular-beam Mass Spectrometer.

    Science.gov (United States)

    Köhler, Markus; Oßwald, Patrick; Krueger, Dominik; Whitside, Ryan

    2018-02-19

    This manuscript describes a high-temperature flow reactor experiment coupled to the powerful molecular beam mass spectrometry (MBMS) technique. This flexible tool offers a detailed observation of chemical gas-phase kinetics in reacting flows under well-controlled conditions. The vast range of operating conditions available in a laminar flow reactor enables access to extraordinary combustion applications that are typically not achievable by flame experiments. These include rich conditions at high temperatures relevant for gasification processes, the peroxy chemistry governing the low temperature oxidation regime or investigations of complex technical fuels. The presented setup allows measurements of quantitative speciation data for reaction model validation of combustion, gasification and pyrolysis processes, while enabling a systematic general understanding of the reaction chemistry. Validation of kinetic reaction models is generally performed by investigating combustion processes of pure compounds. The flow reactor has been enhanced to be suitable for technical fuels (e.g. multi-component mixtures like Jet A-1) to allow for phenomenological analysis of occurring combustion intermediates like soot precursors or pollutants. The controlled and comparable boundary conditions provided by the experimental design allow for predictions of pollutant formation tendencies. Cold reactants are fed premixed into the reactor that are highly diluted (in around 99 vol% in Ar) in order to suppress self-sustaining combustion reactions. The laminar flowing reactant mixture passes through a known temperature field, while the gas composition is determined at the reactors exhaust as a function of the oven temperature. The flow reactor is operated at atmospheric pressures with temperatures up to 1,800 K. The measurements themselves are performed by decreasing the temperature monotonically at a rate of -200 K/h. With the sensitive MBMS technique, detailed speciation data is acquired and

  18. Studies on the dose distribution and treatment technique of high energy electron beams

    International Nuclear Information System (INIS)

    Lee, D.H.; Chu, S.S.

    1978-01-01

    Some important properties of high energy electron beams from the linear accelerator, LMR-13, installed in the Yonsei Cancer Center were studied. The results of experimental studies on the problems associated with the 8, 10, and 12 MeV electron beam therapy were as followings; The ionization type dosemeters calibrated by 90 Sr standard source were suitable to the measurements of the outputs and the obsorbed doses in accuracy point of view, and dose measurements using ionization chambers were difficult when measuring doses in small field size and the regions of rapid fall off. The electron energies were measured precisely with an energy spectrometer, and the practical electron energy was calculated within 5% error in the maximum range of the high energy electron beam in water. The correcting factors of perturbated dose distributions owing to radiation field, energy, and materials of the treatment cone were checked and described systematically and thus the variation of dose distributions due to the non-homogeneities of tissues and slopping skin surfaces were completely compensated. The electron beams were adequately diffused using the scatterers, and minimized the bremsstrahlung, irradiation field size, and materials of scatterers. Thus, the therapeutic capacity with the limited electron energy could be extended by improving the dose distributions. (author)

  19. Heterogeneous chemical kinetics by modulated molecular beam mass spectrometry: limitations of technique

    International Nuclear Information System (INIS)

    Olander, D.R.

    1977-01-01

    The advantages and limitations of modulated molecular beam, mass spectrometry as applied to the study of heterogeneous chemical kinetics are reviewed. The process of deducing a model of the surface reaction from experimental data is illustrated by analysis of the hydrogen reduction of uranium dioxide

  20. Stacking fault energy measurements in WSe2 single crystals using weak-beam techniques

    International Nuclear Information System (INIS)

    Agarwal, M.K.; Patel, J.V.; Patel, N.G.

    1981-01-01

    The weak-beam method of electron microscopy is used to observe threefold dislocations in WSe 2 single crystals grown by direct vapour transport method. The widths of the three fold ribbons are used to determine the stacking fault energy in these crystals. Variation of the width of the ribbons with temperature are also studied and discussed. (author)

  1. Glass Fiber Reinforced Polymer (GFRP Bars for Enhancing the Flexural Performance of RC Beams Using Side-NSM Technique

    Directory of Open Access Journals (Sweden)

    Md. Akter Hosen

    2017-05-01

    Full Text Available Reinforced concrete (RC structures require strengthening for numerous factors, such as increased load, modification of the structural systems, structural upgrade or errors in the design and construction stages. The side near-surface mounted (SNSM strengthening technique with glass fiber-reinforced polymer (GFRP bars is a relatively new emerging technique for enhancing the flexural capacities of existing RC elements. Nine RC rectangular beams were flexurally strengthened with this technique and tested under four-point bending loads until failure. The main goal of this study is to optimize the structural capacity of the RC beams by varying the amount of strengthening reinforcement and bond length. The experimental test results showed that strengthening with SNSM GFRP bars significantly enhanced the flexural responses of the specimens compared with the control specimen. The first cracking and ultimate loads, energy absorption capacities, ductility and stiffness were remarkably enhanced by the SNSM technique. It was also confirmed that the bond length of the strengthened reinforcement greatly influences the energy absorption capacities, ductility and stiffness. The effect of the bond length on these properties is more significant compared to the amount of strengthening reinforcement.

  2. Friction of self-lubricating surfaces by ion beam techniques. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, R.S.; Rai, A.K.

    1992-05-01

    UES, Inc. conducted a research and development program designed to establish conditions for ion implantation/mixing of suitable additives into the surfaces of bulk ceramics and metals for obtaining self-lubricating low friction and wear characteristics. The substrates considered were ZrO{sub 2}, Al{sub 2}O{sub 3}, Si{sub 3}N{sub 4}, steel and Ni-base superalloy. The lubricant additives chosen were BaF{sub 2}/CaF{sub 2}Ag, MoS{sub 2}, WS{sub 2}and B{sub 2}O{sub 3}. The initial tasks of the program were to synthesis these lubricant compounds by co-implantation of constituent elements if sufficient beams of desired elements were obtained. The final tasks were to investigate high energy (MeV) ion mixing of deposited coatings as well as to investigate ion beam assisted deposition using low energy ion beams. It was shown that MoS{sub 2} can be synthesized by co-implantation of Mo{sup +} and S{sup +} in ceramic materials with appropriate choice of energies to obtain nearly overlapping depth profiles. The sliding life of DC magnetron sputtered MoS{sub 2} films of thicknesses {approximately}7500{Angstrom} on ceramic materials such as sapphire, Si{sub 3}N{sub 4} and ZrO{sub 3} were improved by ten to thousand fold after 2 Mev Ag{sup +} ion mixing. Ion beam assisted deposition (IBAD) and ion beam mixing were utilized to fabricate self-lubricating coatings of CaF{sub 2}/Ag and BaF/CaF{sub 2}/Ag composites.

  3. Shapes of leaves with parallel venation. Modelling of the Epipactis sp. (Orchidaceae leaves with the help of a system of coupled elastic beams

    Directory of Open Access Journals (Sweden)

    Anna Jakubska-Busse

    2016-06-01

    Full Text Available Static properties of leaves with parallel venation, with particular emphasis on the genus EpipactisZinn, 1757 (Orchidaceae, Neottieae have been modelled with coupled quasi-parallel elastic “beams.” The non-linear theory of strongly bended beams have been employed. The resulting boundary-value problem has been solved numerically with the help of the finite-difference method. Possible dislocations resulting in additional Dirac-delta like forces have been take into account. Morphological similarity of the model and real leaves has been obtained. In particular, the concentrated forces have been shown to cause undulation in the leaves.

  4. Application of the Ta liner technique to produce Ca beams at INFN-Legnaro National Laboratories (INFN-LNL)

    Energy Technology Data Exchange (ETDEWEB)

    Galatà, A., E-mail: alessio.galata@lnl.infn.it; Sattin, M.; Manzolaro, M.; Martini, D.; Facco, A. [INFN-Legnaro National Laboratories, Legnaro (Pd) (Italy); Tinschert, K.; Spaedtke, P.; Lang, R. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Kulevoy, T. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

    2014-02-15

    The ECR ion sources are able to produce a wide variety of highly charged metallic ion beams thanks to the development of different techniques (ovens, sputtering, direct insertion, metal ions from volatile compounds (MIVOC)). In the case of the ovens, the sticking of the hot vapors on the surface of the plasma chamber leads to high material consumption rates. For elements like Ca, a tantalum liner inserted inside the chamber can be used to limit this phenomenon. The modeling of temperature distribution inside the chamber with and without the liner was carried out with COMSOL-multiphysics code. Results of simulation and the comparison with experiments performed at INFN-Legnaro National Laboratories with Ca beams are discussed.

  5. Conventional and conformal technique of external beam radiotherapy in locally advanced cervical cancer: Dose distribution, tumor response, and side effects

    Science.gov (United States)

    Mutrikah, N.; Winarno, H.; Amalia, T.; Djakaria, M.

    2017-08-01

    The objective of this study was to compare conventional and conformal techniques of external beam radiotherapy (EBRT) in terms of the dose distribution, tumor response, and side effects in the treatment of locally advanced cervical cancer patients. A retrospective cohort study was conducted on cervical cancer patients who underwent EBRT before brachytherapy in the Radiotherapy Department of Cipto Mangunkusumo Hospital. The prescribed dose distribution, tumor response, and acute side effects of EBRT using conventional and conformal techniques were investigated. In total, 51 patients who underwent EBRT using conventional techniques (25 cases using Cobalt-60 and 26 cases using a linear accelerator (LINAC)) and 29 patients who underwent EBRT using conformal techniques were included in the study. The distribution of the prescribed dose in the target had an impact on the patient’s final response to EBRT. The complete response rate of patients to conformal techniques was significantly greater (58%) than that of patients to conventional techniques (42%). No severe acute local side effects were seen in any of the patients (Radiation Therapy Oncology Group (RTOG) grades 3-4). The distribution of the dose and volume to the gastrointestinal tract affected the proportion of mild acute side effects (RTOG grades 1-2). The urinary bladder was significantly greater using conventional techniques (Cobalt-60/LINAC) than using conformal techniques at 72% and 78% compared to 28% and 22%, respectively. The use of conformal techniques in pelvic radiation therapy is suggested in radiotherapy centers with CT simulators and 3D Radiotherapy Treatment Planning Systems (RTPSs) to decrease some uncertainties in radiotherapy planning. The use of AP/PA pelvic radiation techniques with Cobalt-60 should be limited in body thicknesses equal to or less than 18 cm. When using conformal techniques, delineation should be applied in the small bowel, as it is considered a critical organ according to RTOG

  6. Novel Electro-Optical Coupling Technique for Magnetic Resonance-Compatible Positron Emission Tomography Detectors

    Directory of Open Access Journals (Sweden)

    Peter D. Olcott

    2009-03-01

    Full Text Available A new magnetic resonance imaging (MRI-compatible positron emission tomography (PET detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

  7. Novel electro-optical coupling technique for magnetic resonance-compatible positron emission tomography detectors.

    Science.gov (United States)

    Olcott, Peter D; Peng, Hao; Levin, Craig S

    2009-01-01

    A new magnetic resonance imaging (MRI)-compatible positron emission tomography (PET) detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL) diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

  8. SU-F-T-188: A Robust Treatment Planning Technique for Proton Pencil Beam Scanning Cranial Spinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, M; Mehta, M; Badiyan, S; Young, K; Malyapa, R; Regine, W; Langen, K [University of Maryland School of Medicine, Baltimore, MD (United States); Yam, M [University of Florida Proton Therapy Institute, Jacksonville, FL (United States)

    2016-06-15

    Purpose: To propose a proton pencil beam scanning (PBS) cranial spinal irradiation (CSI) treatment planning technique robust against patient roll, isocenter offset and proton range uncertainty. Method: Proton PBS plans were created (Eclipse V11) for three previously treated CSI patients to 36 Gy (1.8 Gy/fractions). The target volume was separated into three regions: brain, upper spine and lower spine. One posterior-anterior (PA) beam was used for each spine region, and two posterior-oblique beams (15° apart from PA direction, denoted as 2PO-15) for the brain region. For comparison, another plan using one PA beam for the brain target (denoted as 1PA) was created. Using the same optimization objectives, 98% CTV was optimized to receive the prescription dose. To evaluate plan robustness against patient roll, the gantry angle was increased by 3° and dose was recalculated without changing the proton spot weights. On the re-calculated plan, doses were then calculated using 12 scenarios that are combinations of isocenter shift (±3mm in X, Y, and Z directions) and proton range variation (±3.5%). The worst-case-scenario (WCS) brain CTV dosimetric metrics were compared to the nominal plan. Results: For both beam arrangements, the brain field(s) and upper-spine field overlap in the T2–T5 region depending on patient anatomy. The maximum monitor unit per spot were 48.7%, 47.2%, and 40.0% higher for 1PA plans than 2PO-15 plans for the three patients. The 2PO-15 plans have better dose conformity. At the same level of CTV coverage, the 2PO-15 plans have lower maximum dose and higher minimum dose to the CTV. The 2PO-15 plans also showed lower WCS maximum dose to CTV, while the WCS minimum dose to CTV were comparable between the two techniques. Conclusion: Our method of using two posterior-oblique beams for brain target provides improved dose conformity and homogeneity, and plan robustness including patient roll.

  9. A cone beam CT-guided online plan modification technique to correct interfractional anatomic changes for prostate cancer IMRT treatment

    International Nuclear Information System (INIS)

    Fu Weihua; Yang Yong; Yue, Ning J; Heron, Dwight E; Huq, M Saiful

    2009-01-01

    The purpose of this work is to develop an online plan modification technique to compensate for the interfractional anatomic changes for prostate cancer intensity-modulated radiation therapy (IMRT) treatment based on daily cone beam CT (CBCT) images. In this proposed technique, pre-treatment CBCT images are acquired after the patient is set up on the treatment couch using an in-room laser with the guidance of the setup skin marks. Instead of moving the couch to rigidly align the target or re-planning using the CBCT images, we modify the original IMRT plan to account for the interfractional target motion and deformation based on the daily CBCT image feedback. The multileaf collimator (MLC) leaf positions for each subfield are automatically adjusted in the proposed algorithm based on the position and shape changes of target projection in the beam's eye view (BEV). Three typical prostate cases were adopted to evaluate the proposed technique, and the results were compared with those obtained with bony-structure-based rigid translation correction, prostate-based correction and CBCT-based re-planning strategies. The study revealed that the proposed modification technique is superior to the bony-structure-based and prostate-based correction techniques, especially when interfractional target deformation exists. Its dosimetric performance is closer to that of the re-planned strategy, but with much higher efficiency, indicating that the introduced online CBCT-guided plan modification technique may be an efficient and practical method to compensate for the interfractional target position and shape changes for prostate IMRT.

  10. Cone beam computed tomography in veterinary dentistry: description and standardization of the technique

    International Nuclear Information System (INIS)

    Roza, Marcello R.; Silva, Luiz A.F.; Fioravanti, Maria C. S.; Barriviera, Mauricio

    2009-01-01

    Eleven dogs and four cats with buccodental alterations, treated in the Centro Veterinario do Gama, in Brasilia, DF, Brazil, were submitted to cone beam computed tomography. The exams were carried out in a i-CAT tomograph, using for image acquisition six centimeters height, 40 seconds time, 0.2 voxel, 120 kilovolts and 46.72 milli amperes per second. The ideal positioning of the animal for the exam was also determined in this study and it proved to be fundamental for successful examination, which required a simple and safe anesthetic protocol due to the relatively short period of time necessary to obtain the images. Several alterations and diseases were identified with accurate imaging, demonstrating that cone beam computed tomography is a safe, accessible and feasible imaging method which could be included in the small animal dentistry routine diagnosis. (author)

  11. Development of the techniques for food processing with low-energy electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Todoroki, Setsuko; Hayashi, Toru [National Food Research Inst., Tsukuba, Ibaraki (Japan)

    1999-02-01

    This study aimed to construct a new electron beam irradiation apparatus which allows to perform homogeneous irradiation up to a certain depth of a spherical or granular material through rotating it. And the sterilizing effects of this apparatus on various kinds of spices such as black and white peppers (grains), turmeric (root), coriander (seed), basil (leaves) were investigated to compare with the effects of {gamma}-ray irradiation. Electron beam irradiation was made changing the energy form 200 keV for 15 min to 500 keV for 5 min and a dose-depth curve was drawn for each electron energy. Indicator balls were used to examine the radiation effects. It became possible to make homogeneous irradiation onto a spherical surface of food by using the rotary system of the apparatus. It was demonstrated that satisfactory sterilizing effects as much as those of {gamma}-ray were obtainable by superficial treatments with low-energy electron. (M.N.)

  12. Development of the techniques for food processing with low-energy electron beam

    International Nuclear Information System (INIS)

    Todoroki, Setsuko; Hayashi, Toru

    1999-01-01

    This study aimed to construct a new electron beam irradiation apparatus which allows to perform homogeneous irradiation up to a certain depth of a spherical or granular material through rotating it. And the sterilizing effects of this apparatus on various kinds of spices such as black and white peppers (grains), turmeric (root), coriander (seed), basil (leaves) were investigated to compare with the effects of γ-ray irradiation. Electron beam irradiation was made changing the energy form 200 keV for 15 min to 500 keV for 5 min and a dose-depth curve was drawn for each electron energy. Indicator balls were used to examine the radiation effects. It became possible to make homogeneous irradiation onto a spherical surface of food by using the rotary system of the apparatus. It was demonstrated that satisfactory sterilizing effects as much as those of γ-ray were obtainable by superficial treatments with low-energy electron. (M.N.)

  13. POLYMER COMPOSITE FILMS WITH SIZE-SELECTED METAL NANOPARTICLES FABRICATED BY CLUSTER BEAM TECHNIQUE

    DEFF Research Database (Denmark)

    Ceynowa, F. A.; Chirumamilla, Manohar; Popok, Vladimir

    2017-01-01

    Formation of polymer films with size-selected silver and copper nanoparticles (NPs) is studied. Polymers are prepared by spin coating while NPs are fabricated and deposited utilizing a magnetron sputtering cluster apparatus. The particle embedding into the films is provided by thermal annealing...... after the deposition. The degree of immersion can be controlled by the annealing temperature and time. Together with control of cluster coverage the described approach represents an efficient method for the synthesis of thin polymer composite layers with either partially or fully embedded metal NPs....... Combining electron beam lithography, cluster beam deposition and thermal annealing allows to form ordered arrays of metal NPs on polymer films. Plasticity and flexibility of polymer host and specific properties added by coinage metal NPs open a way for different applications of such composite materials...

  14. A layer correlation technique for pion energy calibration at the 2004 ATLAS Combined Beam Test

    OpenAIRE

    Kovalenko, S.; Khoriauli, G.; C. Driouchi; J. D. Peso; L. Santi; Soloviev, I.; Arik, E.; Bernabeu, J; M. V. Castillo; Atkinson, T; Tegenfeldt, F.; Weidberg, A.R.; Røhne, O.; F. Anghinolfi; S. Chouridou

    2016-01-01

    A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of energy deposits in the calorimeter layers, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Gea...

  15. Depth profile analysis of thin TiOxNy films using standard ion beam analysis techniques and HERDA

    International Nuclear Information System (INIS)

    Markwitz, A.; Dytlewski, N.; Cohen, D.

    1999-01-01

    Ion beam assisted deposition is used to fabricate thin titanium oxynitride films (TiO x N y ) at Industrial Research (typical film thickness 100nm). At the Institute of Geological and Nuclear Sciences, the thin films are analysed using non-destructive standard ion beam analysis (IBA) techniques. High-resolution titanium depth profiles are measured with RBS using 1.5MeV 4 He + ions. Non-resonant nuclear reaction analysis (NRA) is performed for investigating the amounts of O and N in the deposited films using the reactions 16 O(d,p) 17 O at 920 keV and 14 N(d,α) 12 C at 1.4 MeV. Using a combination of these nuclear techniques, the stoichiometry as well as the thickness of the layers is revealed. However, when oxygen and nitrogen depth profiles are required for investigating stoichiometric changes in the films, additional nuclear analysis techniques such as heavy ion elastic recoil detection (HERDA) have to be applied. With HERDA, depth profiles of N, O, and Ti are measured simultaneously. In this paper comparative IBA measurement s of TiO x N y films with different compositions are presented and discussed

  16. Modified electron beam induced current technique for in(Ga)As/InAsSb superlattice infrared detectors

    Science.gov (United States)

    Yoon, N.; Reyner, C. J.; Ariyawansa, G.; Duran, J. M.; Scheihing, J. E.; Mabon, J.; Wasserman, D.

    2017-08-01

    Electron beam induced current (EBIC) measurements provide a powerful tool for characterizing semiconductor based materials and devices. By measuring the current generated by the electron beam of a scanning electron microscope (SEM), EBIC allows us to extract the minority carrier diffusion length (L) and the surface recombination velocity to diffusivity ratio (S/D) of a material. When combined with information on minority carrier lifetime (τ), for instance from time-resolved photoluminescence measurements, the minority carrier mobility of the material can be extracted. However, the EBIC technique relies heavily on the accurate modeling of the carrier generation and collection process. Traditionally, this was achieved using a combination of empirical analytical expressions (and later Monte Carlo simulations) for carrier generation and analytical diffusion/recombination expressions for carrier collection. This approach introduces significant uncertainties into the extracted material parameters. Here, we present a numerical approach to EBIC modeling which improves the spatial resolution of our model, while also retaining information regarding the relative EBIC signal as a function of incident beam energies and currents. We apply this technique to investigate the temperature dependent minority carrier mobility of InAs/InAsSb and InGaAs/InAsSb strained layer superlattice infrared detectors and compare our results to the values obtained using external quantum efficiency measurements of the same samples. Our approach not only allows for an improvement in the uncertainty of the extracted material parameters, but also offers insight into the material and device behavior as a function of nonequilibrium carrier concentration. The technique presented here offers potentially improved characterization of not only infrared detectors, but a range of semiconductor-based devices.

  17. Synthesis of dynamic phase profile by the correlation technique for spatial control of optical beams in multiplexing and switching

    Science.gov (United States)

    Bugaychuk, Svitlana A.; Gnatovskyy, Vladimir O.; Sidorenko, Andrey V.; Pryadko, Igor I.; Negriyko, Anatoliy M.

    2015-11-01

    New approach for the correlation technique, which is based on multiple periodic structures to create a controllable angular spectrum, is proposed and investigated both theoretically and experimentally. The transformation of an initial laser beam occurs due to the actions of consecutive phase periodic structures, which may differ by their parameters. Then, after the Fourier transformation of a complex diffraction field, the output diffraction orders will be changed both by their intensities and by their spatial position. The controllable change of output angular spectrum is carried out by a simple control of the parameters of the periodic structures. We investigate several simple examples of such management.

  18. Pulse radiolysis based on a femtosecond electron beam and a femtosecond laser light with double-pulse injection technique

    International Nuclear Information System (INIS)

    Yang Jinfeng; Kondoh, Takafumi; Kozawa, Takahiro; Yoshida, Youichi; Tagawa, Seiichi

    2006-01-01

    A new pulse radiolysis system based on a femtosecond electron beam and a femtosecond laser light with oblique double-pulse injection was developed for studying ultrafast chemical kinetics and primary processes of radiation chemistry. The time resolution of 5.2 ps was obtained by measuring transient absorption kinetics of hydrated electrons in water. The optical density of hydrated electrons was measured as a function of the electron charge. The data indicate that the double-laser-pulse injection technique was a powerful tool for observing the transient absorptions with a good signal to noise ratio in pulse radiolysis

  19. Dynamic characterization, monitoring and control of rotating flexible beam-mass structures via piezo-embedded techniques

    Science.gov (United States)

    Lai, Steven H.-Y.

    1992-01-01

    A variational principle and a finite element discretization technique were used to derive the dynamic equations for a high speed rotating flexible beam-mass system embedded with piezo-electric materials. The dynamic equation thus obtained allows the development of finite element models which accommodate both the original structural element and the piezoelectric element. The solutions of finite element models provide system dynamics needed to design a sensing system. The characterization of gyroscopic effect and damping capacity of smart rotating devices are addressed. Several simulation examples are presented to validate the analytical solution.

  20. Solitary-wave emission fronts, spectral chirping, and coupling to beam acoustic modes in RPIC simulation of SRS backscatter.

    Energy Technology Data Exchange (ETDEWEB)

    DuBois, D. F. (Donald F.); Yin, L. (Lin); Daughton, W. S. (William S.); Bezzerides, B. (Bandel); Dodd, E. S. (Evan S.); Vu, H. X. (Hoanh X.)

    2004-01-01

    Detailed diagnostics of quasi-2D RPIC simulations of backward stimulated Raman scattering (BSRS), from single speckles under putative NIF conditions, reveal a complex spatio-temporal behavior. The scattered light consists of localized packets, tens of microns in width, traveling toward the laser at an appreciable fraction of the speed of light. Sub pico-second reflectivity pulses occur as these packets leave the system. The LW activity consists of a front traveling with the light packets with a wake of free LWs traveling in the laser direction. The parametric coupling occurs in the front where the scattered light and LW overlap and are strongest. As the light leaves the plasma the LW quickly decays, liberating its trapped electrons. The high frequency part of the |n{sub e}(k,{omega})|{sup 2} spectrum, where n{sub e} is the electron density fluctuation, consists of a narrow streak or straight line with a slope that is the velocity of the parametric front. The time dependence of |n{sub e}(k,t)|{sup 2}, shows that during each pulse the most intense value of k also 'chirps' to higher values, consistent with the k excursions seen in the |n{sub e}(k,{omega})|{sup 2} spectrum. But k does not always return, in the subsequent pulses, to the original parametrically matched value, indicating that, in spite of side loss, the electron distribution function does not return to its original Maxwellian form. Liberated pulses of hot electrons result in down-stream, bump on tail distributions that excite LWs and beam acoustic modes deeper in the plasma. The frequency broadened spectra are consistent with Thomson scatter spectra observed in TRIDENT single-hot-spot experiments in the high k{lambda}{sub D}, trapping regime. Further details including a comparison of results from full PIC simulations, and movies of the spatio-temporal behavior, will be given in the poster by L Yin et al.

  1. Modal Analysis in Periodic, Time-Varying Systems with emphasis to the Coupling between Flexible Rotating Beams and Non-Rotating Flexible Structures

    DEFF Research Database (Denmark)

    Saracho, C. M.; Santos, Ilmar

    2003-01-01

    The analysis of dynamical response of a system built by a non-rotating structure coupled to flexible rotating beams is the purpose of this work. The effect of rotational speed upon the beam natural frequencies is well-known, so that an increase in the angular speeds leads to an increase in beam...... natural frequencies, the so-called centrifugal stiffening. The equations of motion of such a global system present matrices with time-depending coefficients, which vary periodically with the angular rotor speed, and introduce parametric vibrations into the system response. The principles of modal analysis...... for time-invariant linear systems are expanded to investigate time-varying systems. Concepts as eigenvalues and eigenvectors, which in this special case are also time-varying, are used to analyse the dynamical response of global system. The time-varying frequencies and modes are also illustrated....

  2. Assembling of a low energy ion beam analysis facility and use of Nuclear Microprobe techniques in geological studies

    Energy Technology Data Exchange (ETDEWEB)

    Utui, R

    1996-11-01

    In this work, both PIXE and ion beam induced luminescence, or just Ionoluminescence (IL) were used for geochemical studies. The possibility of rapid absolute quantification of elements in the ppm level by PIXE combined with the yet higher sensitivity of IL to transition metals and Rare Earth Elements (REE) activators, in the absence of quenching phenomena, allow for a synergic use of the two methods in geological applications with enhanced sensitivity. IL and PIXE were combined for studying REE distribution in apatite minerals and ion beam induced damage in inorganic material in general with emphasis to synthetically grown zircon crystals doped with REE. Due to the sensitivity of IL to changes in chemical bonding in the material, beam damage effects can be studied even at low integrated doses, through wavelength shift or fading of the induced light. Micro PIXE technique was used for studying profile concentrations of trace elements in pyrite grains and of elements used as geothermometers. Geothermometry allowed to assess the cooling rates in iron meteorites and the mineralization conditions in metamorphic rocks, attempting to describe the tectonic history of the terranes, with application in petrologic studies and geological prospecting. 148 refs.

  3. Assembling of a low energy ion beam analysis facility and use of Nuclear Microprobe techniques in geological studies

    International Nuclear Information System (INIS)

    Utui, R.

    1996-11-01

    In this work, both PIXE and ion beam induced luminescence, or just Ionoluminescence (IL) were used for geochemical studies. The possibility of rapid absolute quantification of elements in the ppm level by PIXE combined with the yet higher sensitivity of IL to transition metals and Rare Earth Elements (REE) activators, in the absence of quenching phenomena, allow for a synergic use of the two methods in geological applications with enhanced sensitivity. IL and PIXE were combined for studying REE distribution in apatite minerals and ion beam induced damage in inorganic material in general with emphasis to synthetically grown zircon crystals doped with REE. Due to the sensitivity of IL to changes in chemical bonding in the material, beam damage effects can be studied even at low integrated doses, through wavelength shift or fading of the induced light. Micro PIXE technique was used for studying profile concentrations of trace elements in pyrite grains and of elements used as geothermometers. Geothermometry allowed to assess the cooling rates in iron meteorites and the mineralization conditions in metamorphic rocks, attempting to describe the tectonic history of the terranes, with application in petrologic studies and geological prospecting. 148 refs

  4. Pulsed and monoenergetic beams for neutron cross-section measurements using activation and scattering techniques at Triangle Universities Nuclear Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Hutcheson, A. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States)]. E-mail: hutch@tunl.duke.edu; Angell, C.T. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Becker, J.A. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Boswell, M. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Crowell, A.S. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Dashdorj, D. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Fallin, B. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Fotiades, N. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Howell, C.R.; Karwowski, H.J.; Kelley, J.H.; Kiser, M. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Macri, R.A. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Nelson, R.O. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Pedroni, R.S. [NC A and T State University, 1601 East Market Street, Greensboro, NC 27411 (United States); Tonchev, A.P.; Tornow, W. [Triangle Universities Nuclear Laboratory, P.O. Box 90308, Durham, NC 27708 (United States); Vieira, D.J. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Weisel, G.J. [Penn State Altoona, 3000 Ivyside Park, Altoona, PA 16601 (United States); Wilhelmy, J.B. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

    2007-08-15

    In support of the Stewardship Science Academic Alliances initiative, an experimental program has been developed at Triangle Universities Nuclear Laboratory (TUNL) to measure (n,xn) cross-sections with both in-beam and activation techniques with the goal of improving the partial cross-section database for the NNSA Stockpile Stewardship Program. First experimental efforts include excitation function measurements on {sup 235,238}U and {sup 241}Am using pulsed and monoenergetic neutron beams with E {sub n} = 5-15 MeV. Neutron-induced partial cross-sections were measured by detecting prompt {gamma} rays from the residual nuclei using various combinations of clover and planar HPGe detectors in the TUNL shielded neutron source area. Complimentary activation measurements using DC neutron beams have also been performed in open geometry in our second target area. The neutron-induced activities were measured in the TUNL low-background counting area. In this presentation, we include detailed information about the irradiation procedures and facilities and preliminary data on first measurements using this capability.

  5. Complex Interaction Mechanisms between Dislocations and Point Defects Studied in Pure Aluminium by a Two-Wave Acoustic Coupling Technique

    Science.gov (United States)

    Bremnes, O.; Progin, O.; Gremaud, G.; Benoit, W.

    1997-04-01

    Ultrasonic experiments using a two-wave coupling technique were performed on 99.999% pure Al in order to study the interaction mechanisms occurring between dislocations and point defects. The coupling technique consists in measuring the attenuation of ultrasonic waves during low-frequency stress cycles (t). One obtains closed curves () called signatures whose shape and evolution are characteristic of the interaction mechanism controlling the low-frequency dislocation motion. The signatures observed were attributed to the interaction of the dislocations with extrinsic point defects. A new interpretation of the evolution of the signatures measured below 200 K with respect to temperature and stress frequency had to be established: they are linked to depinning of immobile point defects, whereas a thermally activated depinning mechanism does not fit the observations. The signatures measured between 200 and 370 K were interpreted as dragging and depinning of extrinsic point defects which are increasingly mobile with temperature.

  6. Implementation of a secondary-ion tritium beam by means of the associated particle technique and its test on a gold target

    Energy Technology Data Exchange (ETDEWEB)

    Policroniades, R.; Fernández-Arnáiz, J.; Murillo, G.; Moreno, E.; Villaseñor, P.; Méndez, B. [Departamento de Aceleradores, Instituto Nacional de Investigaciones Nucleares, Carr. México-Toluca S/N, Ocoyoacac, Estado de México 52750 (Mexico); Chávez, E.; Ortíz-Salazar, M.E.; Huerta, A. [Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México, D.F. 01000 (Mexico); Varela-González, A. [Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, A.P. 20-364, México, D.F. 01000 (Mexico)

    2014-05-21

    In this work we present the implementation and characterization of a (secondary ion) tritium beam generated through the D(d,t)p reaction, at deuteron energies of 2.0 and 1.88 MeV, tagging the tritium ions with the associated particle technique. In order to prove its utility as a projectile for scientific applications, this beam was made to impinge on a thin gold target to observe expected elastic scattering events. - Highlights: • A new secondary ion tritium beam obtained through the D(d,t)3He reaction. • Tritium beam tagging by the associated particle technique. • A low energy Tritium beam without radiation contamination of equipment. • Tritium elastic scattering on gold.

  7. Implementation of a secondary-ion tritium beam by means of the associated particle technique and its test on a gold target

    International Nuclear Information System (INIS)

    Policroniades, R.; Fernández-Arnáiz, J.; Murillo, G.; Moreno, E.; Villaseñor, P.; Méndez, B.; Chávez, E.; Ortíz-Salazar, M.E.; Huerta, A.; Varela-González, A.

    2014-01-01

    In this work we present the implementation and characterization of a (secondary ion) tritium beam generated through the D(d,t)p reaction, at deuteron energies of 2.0 and 1.88 MeV, tagging the tritium ions with the associated particle technique. In order to prove its utility as a projectile for scientific applications, this beam was made to impinge on a thin gold target to observe expected elastic scattering events. - Highlights: • A new secondary ion tritium beam obtained through the D(d,t)3He reaction. • Tritium beam tagging by the associated particle technique. • A low energy Tritium beam without radiation contamination of equipment. • Tritium elastic scattering on gold

  8. Micro-beam X-ray fluorescence and absorption imaging techniques at the IAEA Laboratories

    International Nuclear Information System (INIS)

    Wegrzynek, Dariusz; Markowicz, A.; Bamford, S.; Chinea-Cano, E.; Bogovac, M.

    2005-01-01

    X-ray tube based, micro-beam X-ray fluorescence scanning spectrometer has been equipped with two energy dispersive X-ray detectors. The two-detector configuration allows for simultaneous collection of X-ray fluorescence (XRF) and transmitted X-ray beam signals with a spatial resolution in the range of 10-50 μm, depending on the X-ray focussing element in use. The XRF signal is collected with a standard, liquid nitrogen cooled Si(Li) detector. The X-ray beam transmitted through the sample is acquired with a thermoelectrically cooled, silicon drift (SD) detector. The data acquisition is carried out in a fully automatic way under control of the SPECTOR-LOCATOR software. The software controls the scanning procedure and X-ray spectra acquisition during the scan. The energy dispersive X-ray spectra collected at every 'pixel' are stored for off-line processing. For selected regions of interest (ROI's), the element maps are constructed and displayed on-line. The spectrometer has been used for mapping elemental distributions and for performing 2D- and 3D-tomograpic imaging of minute objects in X-ray absorption and in X-ray fluorescence mode. A unique feature of the described system is simultaneous utilization of the two detectors, Si(Li) and SD, which adds new options for quantitative analysis and data interpretation. Examples of elemental mapping and 3D tomographic imaging as well as the advanced features of the SPECTOR-LOCATOR measurement control and data acquisition software are presented in this work

  9. Physicochemical Study of Irradiated polypropylene/Organo :Modified Montmorillonite Composites by Using Electron Beam Irradiation Technique

    International Nuclear Information System (INIS)

    Hassan, M.S.

    2008-01-01

    Polypropylene/ Organo modified montmorillonite composites (PP/ OMMT) were prepared by melt blending with a twin screw extruder. The thermal properties by thermo gravimetric analysis (TGA), the dispersion of OMMT of macromolecules by X-ray diffraction (XRD), mechanical properties and the morphology by scanning electron microscopy (SEM) were investigated. The effect of electron beam irradiation on these properties was also studied. The results showed an intercalation between the silicate layers and the PP polymer matrix. The (PP/ OMMT) composites exhibit higher thermal stability and lower mechanical properties than pure polypropylene

  10. Analyses of inks and papers in historical documents through external beam PIXE techniques

    International Nuclear Information System (INIS)

    Cahill, T.A.; Kusko, B.; California Univ., Davis; Schwab, R.N.

    1981-01-01

    PIXE analyses of documents can be carried out to high senstitivty in an external beam configuration designed to protect historical materials from damage. Test runs have shown that a properbly designed system with high solid angle can operate at less than 1% of the flux necessary to cause any discoloration whatsoever on papers of the 17th and 18th centuries. The composition of these papers is suprisingly complex, yet retains distinct association with the historical period, paper source, and even the individual sheets of paper that are folded and cut to make groups of pages. Early studies are planned on historical forgeries. (orig.)

  11. Scanning ion micro-beam techniques for measuring diffusion in heterogeneous materials

    International Nuclear Information System (INIS)

    Jenneson, P.M.; Clough, A.S.

    1998-01-01

    A raster scanning MeV micro-beam of 1 H + or 3 He + ions was used to study the diffusion of small molecules in heterogeneous materials. The location of elemental contaminants (heavier than Lithium) in polymer insulated cables was studied with 1 H micro-Particle Induced X-ray Emission (μPIXE). Concentration profiles of a deuterated molecule in a hair fibre were determined with 3 He micro-Nuclear Reaction Analysis (μNRA). Chlorine and heavy water (D 2 0) diffusion into cement pastes were profiled using a combination of 3 He μPIXE and μNRA. (authors)

  12. Prestressed CFRP Fabrics for Flexural Strengthening of Concrete Beams with an Easy Prestressing Technique

    Science.gov (United States)

    Şakar, G.; Tanarslan, H. M.

    2014-09-01

    It is proposed to use prestressed CFRP plates for strengthening in order to prevent their debonding and thus to increase their strengthening efficiency. For this purpose, and easy-to-use piece of equipment was created. To determine the effectiveness of this method, an experimental program was carried out, and the effect of prestressed CFRP on the behavior and ultimate strength of reinforced concrete beams was examined in threepoint bending tests. A remarkable increase in their strength with debonding was seen for every specimen to which a prestressed CFRP plate had been applied.

  13. Liquid separation techniques coupled with mass spectrometry for chiral analysis of pharmaceuticals compounds and their metabolites in biological fluids.

    OpenAIRE

    Erny, Guillaume L.; Cifuentes, Alejandro

    2006-01-01

    Determination of the chiral composition of drugs is nowadays a key step in order to determine purity, activity, bioavailability, biodegradation, etc, of pharmaceuticals. In this manuscript, works published for the last 5 years on the analysis of chiral drugs by liquid separation techniques coupled with mass spectrometry are reviewed. Namely, chiral analysis of pharmaceuticals including e.g., antiinflammatories, antihypertensives, relaxants, etc, by liquid chromatography-mass spectrometry and ...

  14. Application of a Coupled Eulerian-Lagrangian Technique on Constructability Problems of Site on Very Soft Soil

    Directory of Open Access Journals (Sweden)

    Junyoung Ko

    2017-10-01

    Full Text Available This paper presents the application of the Coupled Eulerian–Lagrangian (CEL technique on the constructability problems of site on very soft soil. The main objective of this study was to investigate the constructability and application of two ground improvement methods, such as the forced replacement method and the deep mixing method. The comparison between the results of CEL analyses and field investigations was performed to verify the CEL modelling. The behavior of very soft soil and constructability with methods can be appropriately investigated using the CEL technique, which would be useful tools for comprehensive reviews in preliminary design.

  15. Formation of scandium nitride (ScN) layer on gallium arsenide (GaAs) substrate using a combined technique of e-beam evaporator and ammonia annealing treatment

    Energy Technology Data Exchange (ETDEWEB)

    Yong Shee Meng, Alvin [Institute of Nano Optoelectronics Research and Technology (INOR), sains@usm, Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang (Malaysia); Zainal, Norzaini, E-mail: norzaini@usm.my [Nano Optoelectronics Research and Laboratory, Universiti Sains Malaysia, sains@usm, Persiaran Bukit Jambul, 11900, Bayan Lepas, Penang (Malaysia); Hassan, Zainuriah; Ibrahim, Kamarulazizi [Institute of Nano Optoelectronics Research and Technology (INOR), sains@usm, Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang (Malaysia)

    2015-12-30

    Graphical abstract: - Highlights: • Forming ScN layer using electron e-beam evaporator with successive NH{sub 3} annealing thermal has been successfully demonstrated. • NH{sub 3} annealing played the role in changing the grain structure of the ScN layer. • The existence of Sc−N bonds was confirmed by XPS measurement. • The 900 °C annealed ScN layer showed the best structural and optical characteristics. • ScN layer annealed at 980 °C exhibited poor structural and optical characteristics. - Abstract: A demonstration on a new technique of growing ScN using electron beam (e-beam) evaporator, coupled with successive ammonia (NH{sub 3}) annealing treatment is presented in this paper. The annealing temperature was varied at 750, 800, 850, 900 and 980 °C in order to obtain the best ScN layer. It was found that as the annealing temperature increased, the surface morphology of the ScN layer changed and ScN grains formed abundantly on the surface. The best surface of ScN layer was found in the 900 °C annealed sample. However, the roughness of the ScN increased with temperature. The photoluminescence (PL) peak of the near-to-band-edge (NBE) of ScN was observable in all samples and its intensity was the highest in the 900 °C annealed sample. Note that when the annealing treatment was conducted at 980 °C, the GaN PL peak is observable. Raman peaks of TO(X) of ScN were much evident at the annealing temperature above 900 °C. The formation of Sc−N bonds was confirmed by X-ray spectroscopy (XPS) measurement. In the end of this work, we propose that the formation of ScN using the above techniques was successful, with thermal annealing at the temperature of 900 °C.

  16. Instruments and techniques for analysing the time-resolved transverse phase space distribution of high-brightness electron beams

    International Nuclear Information System (INIS)

    Rudolph, Jeniffa

    2012-01-01

    This thesis deals with the instruments and techniques used to characterise the transverse phase space distribution of high-brightness electron beams. In particular, methods are considered allowing to measure the emittance as a function of the longitudinal coordinate within the bunch (slice emittance) with a resolution in the ps to sub-ps range. The main objective of this work is the analysis of techniques applicable for the time-resolved phase space characterisation for future high-brightness electron beam sources and single-pass accelerators based on these. The competence built up by understanding and comparing different techniques is to be used for the design and operation of slice diagnostic systems for the Berlin Energy Recovery Linac Project (BERLinPro). In the framework of the thesis, two methods applicable for slice emittance measurements are considered, namely the zero-phasing technique and the use of a transverse deflector. These methods combine the conventional quadrupole scan technique with a transfer of the longitudinal distribution into a transverse distribution. Measurements were performed within different collaborative projects. The experimental setup, the measurement itself and the data analysis are discussed as well as measurement results and simulations. In addition, the phase space tomography technique is introduced. In contrast to quadrupole scan-based techniques, tomography is model-independent and can reconstruct the phase space distribution from simple projected measurements. The developed image reconstruction routine based on the Maximum Entropy algorithm is introduced. The quality of the reconstruction is tested using different model distributions, simulated data and measurement data. The results of the tests are presented. The adequacy of the investigated techniques, the experimental procedures as well as the developed data analysis tools could be verified. The experimental and practical experience gathered during this work, the

  17. Growth of CdTe on Si(100) surface by ionized cluster beam technique: Experimental and molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Araghi, Houshang, E-mail: araghi@aut.ac.ir [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Zabihi, Zabiholah [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Nayebi, Payman [Department of Physics, College of Technical and Engineering, Saveh Branch, Islamic Azad University, Saveh (Iran, Islamic Republic of); Ehsani, Mohammad Mahdi [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2016-10-15

    II–VI semiconductor CdTe was grown on the Si(100) substrate surface by the ionized cluster beam (ICB) technique. In the ICB method, when vapors of solid materials such as CdTe were ejected through a nozzle of a heated crucible into a vacuum region, nanoclusters were created by an adiabatic expansion phenomenon. The clusters thus obtained were partially ionized by electron bombardment and then accelerated onto the silicon substrate at 473 K by high potentials. The cluster size was determined using a retarding field energy analyzer. The results of X-ray diffraction measurements indicate the cubic zinc blende (ZB) crystalline structure of the CdTe thin film on the silicon substrate. The CdTe thin film prepared by the ICB method had high crystalline quality. The microscopic processes involved in the ICB deposition technique, such as impact and coalescence processes, have been studied in detail by molecular dynamics (MD) simulation.

  18. Titanium carbide coatings on molybdenum by means of reactive sputtering and electron beam techniques

    International Nuclear Information System (INIS)

    Obata, T.; Aida, H.; Hirohata, Y.; Mohri, M.; Yamashina, T.

    1982-01-01

    This study is an experimental investigation of TiC coatings on Mo substrate by means of a reactive r.f. sputtering in the presence of CH 4 and a chemical reaction with interdiffusion in the sandwich structure of Ti/C/Mo by electron beam evaporation and heating. Using the reactive sputtering method, a homogeneous TiC coating with stoichiometric composition and good adhesion could be produced in the conditions of the partial pressure range of CH 4 , 2 approx. equal to 5 x 10 -4 Torr (total pressure, Psub(Ar) + Psub(CH) 4 = 5.6 x 10 -2 Torr) at 300 0 C (substrate). By using the electron beams, successively evaporated carbon and Ti on a Mo substrate was heated to 700 0 C to form a TiC surface layer on the top which then remained stable during further heating to 1000 0 C. Godd adhesion was brought about by interdiffusion to produce Mo 2 C layer between TiC layer and Mo substrate. It was also found that further heating of the coating layers subsequent to Ti evaporation on the TiC layer produced thicker TiC layer due to a chemical reaction between Ti and inner carbon layers. This could be a promising method of in situ replenishment for TiC coatings on the first wall and the limiter materials. (orig.)

  19. Two Methods For Simulating the Strong-Strong Beam-Beam Interaction in Hadron Colliders

    International Nuclear Information System (INIS)

    Warnock, Robert L.

    2002-01-01

    We present and compare the method of weighted macro particle tracking and the Perron-Frobenius operator technique for simulating the time evolution of two beams coupled via the collective beam-beam interaction in 2-D and 4-D (transverse) phase space. The coherent dipole modes, with and without lattice nonlinearities and external excitation, are studied by means of the Vlasov-Poisson system

  20. Ion beam analysis techniques for the elemental fingerprinting of fine particle smoke from vegetation burning in NSW

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, D. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accelerator based ion beam analysis (IBA) techniques, including PIXE, PIGME, RBS and PESA, have been used to analyse elemental compositions of airborne particles covering a 60,000 square kilometres area of Wollongong, Sydney and Newcastle. These IBA techniques provide elemental concentrations for over 20 different elements from hydrogen to lead, they include H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Zn, Br and Pb. The four ion beam techniques are performed simultaneously on the 3MV Van de Graaff accelerator at ANSTO and have been described in detail elsewhere. They are sufficiently sensitive to analyse for many of these elements to levels around 10 ng/m{sup 3} or less in about five minutes of accelerator running time per filter. This is more than adequate for aerosol analyses as most filters contain around 150 {mu}g/cm{sup 2} of material which corresponds to about 10{mu}g/m{sup 3} of fine particles in the atmosphere. For this work fine particles are those with diameters less than 2.5{mu}m. Fine particle data has been collected twice a week and analysed for each of the above elements by ANSTO since 1991 at more than 25 different sites throughout NSW. This large dataset set allows us to not only determine the composition of fine particles and to look for signature elements for particular sources but also to use multivariate statistics to define elemental source fingerprints and then to determine the percentage contributions of these fingerprints to the total fine particle mass in the atmosphere. This paper describes the application of these techniques to the study of domestic wood fires and vegetation burning in NSW over a two year period from 1992-93. It also presents, for the first time, fine particle data related to the January 1994 bushfires in NSW. 6 refs., 1 tab., 5 figs.

  1. Ion beam analysis techniques for the elemental fingerprinting of fine particle smoke from vegetation burning in NSW

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, D [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1997-12-31

    Accelerator based ion beam analysis (IBA) techniques, including PIXE, PIGME, RBS and PESA, have been used to analyse elemental compositions of airborne particles covering a 60,000 square kilometres area of Wollongong, Sydney and Newcastle. These IBA techniques provide elemental concentrations for over 20 different elements from hydrogen to lead, they include H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Zn, Br and Pb. The four ion beam techniques are performed simultaneously on the 3MV Van de Graaff accelerator at ANSTO and have been described in detail elsewhere. They are sufficiently sensitive to analyse for many of these elements to levels around 10 ng/m{sup 3} or less in about five minutes of accelerator running time per filter. This is more than adequate for aerosol analyses as most filters contain around 150 {mu}g/cm{sup 2} of material which corresponds to about 10{mu}g/m{sup 3} of fine particles in the atmosphere. For this work fine particles are those with diameters less than 2.5{mu}m. Fine particle data has been collected twice a week and analysed for each of the above elements by ANSTO since 1991 at more than 25 different sites throughout NSW. This large dataset set allows us to not only determine the composition of fine particles and to look for signature elements for particular sources but also to use multivariate statistics to define elemental source fingerprints and then to determine the percentage contributions of these fingerprints to the total fine particle mass in the atmosphere. This paper describes the application of these techniques to the study of domestic wood fires and vegetation burning in NSW over a two year period from 1992-93. It also presents, for the first time, fine particle data related to the January 1994 bushfires in NSW. 6 refs., 1 tab., 5 figs.

  2. Ion beam analysis techniques for the elemental fingerprinting of fine particle smoke from vegetation burning in NSW

    International Nuclear Information System (INIS)

    Cohen, D.

    1996-01-01

    Accelerator based ion beam analysis (IBA) techniques, including PIXE, PIGME, RBS and PESA, have been used to analyse elemental compositions of airborne particles covering a 60,000 square kilometres area of Wollongong, Sydney and Newcastle. These IBA techniques provide elemental concentrations for over 20 different elements from hydrogen to lead, they include H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Zn, Br and Pb. The four ion beam techniques are performed simultaneously on the 3MV Van de Graaff accelerator at ANSTO and have been described in detail elsewhere. They are sufficiently sensitive to analyse for many of these elements to levels around 10 ng/m 3 or less in about five minutes of accelerator running time per filter. This is more than adequate for aerosol analyses as most filters contain around 150 μg/cm 2 of material which corresponds to about 10μg/m 3 of fine particles in the atmosphere. For this work fine particles are those with diameters less than 2.5μm. Fine particle data has been collected twice a week and analysed for each of the above elements by ANSTO since 1991 at more than 25 different sites throughout NSW. This large dataset set allows us to not only determine the composition of fine particles and to look for signature elements for particular sources but also to use multivariate statistics to define elemental source fingerprints and then to determine the percentage contributions of these fingerprints to the total fine particle mass in the atmosphere. This paper describes the application of these techniques to the study of domestic wood fires and vegetation burning in NSW over a two year period from 1992-93. It also presents, for the first time, fine particle data related to the January 1994 bushfires in NSW. 6 refs., 1 tab., 5 figs

  3. Study of Sb/SnO{sub 2} bi-layer films prepared by ion beam sputtering deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chun-Min [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC (China); Huang, Chun-Chieh [Department of Electrical Engineering, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Township, Kaohsiung 833, Taiwan, ROC (China); Kuo, Jui-Chao [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC (China); Huang, Jow-Lay, E-mail: jlh888@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC (China); Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan, ROC (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan, ROC (China)

    2014-11-03

    In the present work, bi-layer thin films of Sb/SnO{sub 2} were produced on unheated glass substrates using ion beam sputtering (IBS) technique without post annealing treatment. The thickness of Sb layers was varied from 2 to 10 nm and the Sb layers were deposited on SnO{sub 2} layers having thicknesses of 40 nm to 115 nm. The effect of thickness was studied on the morphological, electrical and optical properties. The Sb/SnO{sub 2} bi-layer resulted in lowering the electrical resistivity as well as reducing the optical transmittance. However, the optical and electrical properties of the bi-layer films were mainly influenced by the thickness of Sb layers due to progressive transfer in structures from aggregate to continuous films. The bi-layer films show the electrical resistivity of 1.4 × 10{sup −3} Ω cm and an optical transmittance of 26% for Sb film having 10 nm thickness. - Highlights: • Bi-layer Sb/SnO{sub 2} structures were synthesized by ion beam sputtering (IBS) technique. • The 6 nm-thick Sb film is a transition region in this study. • The conductivity of the bi-layer films is increased as Sb thickness increases. • The transmittance of the bi-layer films is decreased as Sb thickness increases.

  4. Determining the stereochemical structures of molecular ions by ''Coulomb-explosion'' techniques with fast (MeV) molecular ion beams

    International Nuclear Information System (INIS)

    Gemmell, D.S.

    1980-01-01

    Recent studies on the dissociation of fast (MeV) molecular ion beams in thin foils suggest a novel alternative approach to the determination of molecular ion structures. In this article we review some recent high-resolution studies on the interactions of fast molecular ion beams with solid and gaseous targets and indicate how such studies may be applied to the problem of determining molecular ion structures. The main features of the Coulomb explosion of fast-moving molecular ion projectiles and the manner in which Coulomb-explosion techniques may be applied to the problem (difficult to attack by more conventional means) of determining the stereochemical structures of molecular ions has been described in this paper. Examples have been given of early experiments designed to elicit structure information. The techniques are still in their infancy, and it is to be expected that as both the technology and the analysis are refined, the method will make valuable contributions to the determination of molecular ion structures

  5. A technique for simultaneous detection of individual vortex states of Laguerre-Gaussian beams transmitted through an aqueous suspension of microparticles

    Science.gov (United States)

    Khonina, S. N.; Karpeev, S. V.; Paranin, V. D.

    2018-06-01

    A technique for simultaneous detection of individual vortex states of the beams propagating in a randomly inhomogeneous medium is proposed. The developed optical system relies on the correlation method that is invariant to the beam wandering. The intensity distribution formed at the optical system output does not require digital processing. The proposed technique based on a multi-order phase diffractive optical element (DOE) is studied numerically and experimentally. The developed detection technique is used for the analysis of Laguerre-Gaussian vortex beams propagating under conditions of intense absorption, reflection, and scattering in transparent and opaque microparticles in aqueous suspensions. The performed experimental studies confirm the relevance of the vortex phase dependence of a laser beam under conditions of significant absorption, reflection, and scattering of the light.

  6. The creation of strongly coupled plasmas using an intense heavy ion beam: low-entropy compression of hydrogen and the problem of hydrogen metallization

    CERN Document Server

    Tahir, N A; Shutov, A; Varentsov, D; Udrea, S; Hoffmann, Dieter H H; Juranek, H; Redmer, R; Portugues, R F; Lomonosov, I V; Fortov, V E

    2003-01-01

    Intense heavy ion beams deposit energy very efficiently over extended volumes of solid density targets, thereby creating large samples of strongly coupled plasmas. Intense beams of energetic heavy ions are therefore an ideal tool to research this interesting field. It is also possible to design experiments using special beam-target geometries to achieve low-entropy compression of samples of matter. This type of experiments is of particular interest for studying the problem of hydrogen metallization. In this paper we present a design study of such a proposed experiment that will be carried out at the future heavy ion synchrotron facility SIS100, at the Gesellschaft fuer Schwerionenforschung, Darmstadt. This study has been done using a two-dimensional hydrodynamic computer code. The target consists of a solid hydrogen cylinder that is enclosed in a thick shell of lead whose one face is irradiated with an ion beam which has an annular (ring shaped) focal spot. The beam intensity and other parameters are consider...

  7. Residual dipolar couplings : a new technique for structure determination of proteins in solution

    NARCIS (Netherlands)

    van Lune, Frouktje Sapke

    2004-01-01

    The aim of the work described in this thesis was to investigate how residual dipolar couplings can be used to resolve or refine the three-dimensional structure of one of the proteins of the phosphoenol-pyruvate phosphotransferase system (PTS), the main transport system for carbohydrates in

  8. Laser vaporization/ionization interface for coupling microscale separation techniques with mass spectrometry

    Science.gov (United States)

    Yeung, E.S.; Chang, Y.C.

    1999-06-29

    The present invention provides a laser-induced vaporization and ionization interface for directly coupling microscale separation processes to a mass spectrometer. Vaporization and ionization of the separated analytes are facilitated by the addition of a light-absorbing component to the separation buffer or solvent. 8 figs.

  9. Fiber‐free coupling between bulk laser beams and on‐chip polymer‐based multimode waveguides

    DEFF Research Database (Denmark)

    Jensen, Thomas Glasdam; Nielsen, Lars Bue; Kutter, Jörg Peter

    2011-01-01

    light from a bulk beam to on‐chip waveguides and back into a bulk beam again. Using this setup, as much as 20% of the light coming from the source can be retrieved after passing through the on‐chip waveguides. The proposed setup is based on a pin‐aided alignment system that makes it possible to change...

  10. Beam based measurement of beam position monitor electrode gains

    Directory of Open Access Journals (Sweden)

    D. L. Rubin

    2010-09-01

    Full Text Available Low emittance tuning at the Cornell Electron Storage Ring (CESR test accelerator depends on precision measurement of vertical dispersion and transverse coupling. The CESR beam position monitors (BPMs consist of four button electrodes, instrumented with electronics that allow acquisition of turn-by-turn data. The response to the beam will vary among the four electrodes due to differences in electronic gain and/or misalignment. This variation in the response of the BPM electrodes will couple real horizontal offset to apparent vertical position, and introduce spurious measurements of coupling and vertical dispersion. To alleviate this systematic effect, a beam based technique to measure the relative response of the four electrodes has been developed. With typical CESR parameters, simulations show that turn-by-turn BPM data can be used to determine electrode gains to within ∼0.1%.

  11. Beam based measurement of beam position monitor electrode gains

    Science.gov (United States)

    Rubin, D. L.; Billing, M.; Meller, R.; Palmer, M.; Rendina, M.; Rider, N.; Sagan, D.; Shanks, J.; Strohman, C.

    2010-09-01

    Low emittance tuning at the Cornell Electron Storage Ring (CESR) test accelerator depends on precision measurement of vertical dispersion and transverse coupling. The CESR beam position monitors (BPMs) consist of four button electrodes, instrumented with electronics that allow acquisition of turn-by-turn data. The response to the beam will vary among the four electrodes due to differences in electronic gain and/or misalignment. This variation in the response of the BPM electrodes will couple real horizontal offset to apparent vertical position, and introduce spurious measurements of coupling and vertical dispersion. To alleviate this systematic effect, a beam based technique to measure the relative response of the four electrodes has been developed. With typical CESR parameters, simulations show that turn-by-turn BPM data can be used to determine electrode gains to within ˜0.1%.

  12. Cu-Fe welding techniques by electromagnetic and electron beam welding processes

    International Nuclear Information System (INIS)

    Kumar, Satendra; Saroj, P.C.; Kulkarni, M.R.; Sharma, A.; Rajawat, R.K.; Saha, T.K.

    2015-01-01

    Electromagnetic welding being a solid state welding process has been found suitable for welding Copper and Iron which are conventionally very tricky. Owing to good electrical conductivity of both copper and iron, they are best suited combination for EM welding. For the experimental conditions presented above, 1.0 mm wall thickness of Cu tube was lap welded to Fe disc. A heavy duty four disc stainless steel coil was used for electromagnetic welding of samples. MSLD of the welded samples indicated leak proof joints. Metallographic examination of the welds also revealed defect free interfaces. Electron beam welding is also a non-conventional welding process used for joining dissimilar materials. Autogenous welding of the above specimen was carried out by EBW method for the sake of comparison. A characterization analysis of the above mentioned joining processes will be discussed in the paper. (author)

  13. Implementation techniques and acceleration of DBPF reconstruction algorithm based on GPGPU for helical cone beam CT

    International Nuclear Information System (INIS)

    Shen Le; Xing Yuxiang

    2010-01-01

    The derivative back-projection filtered algorithm for a helical cone-beam CT is a newly developed exact reconstruction method. Due to its large computational complexity, the reconstruction is rather slow for practical use. General purpose graphic processing unit (GPGPU) is an SIMD paralleled hardware architecture with powerful float-point operation capacity. In this paper,we propose a new method for PI-line choice and sampling grid, and a paralleled PI-line reconstruction algorithm implemented on NVIDIA's Compute Unified Device Architecture (CUDA). Numerical simulation studies are carried out to validate our method. Compared with conventional CPU implementation, the CUDA accelerated method provides images of the same quality with a speedup factor of 318. Optimization strategies for the GPU acceleration are presented. Finally, influence of the parameters of the PI-line samples on the reconstruction speed and image quality is discussed. (authors)

  14. Determination of neutron beam quality and evaluation of image quality (neutron radiography technique)

    International Nuclear Information System (INIS)

    Wan Muhammad Saridan Wan Hassan; Manan Munhamad Jaib; Ng Sook Kien; Lai Zhong Yuan; Azali Muhammad; Abd Aziz Mohamed; Mohd Rawi Abdullah

    2005-01-01

    The following topics were presented: beam purity Indicator (BPI) and sensitivity indicator (SI) test objects (ASTM E545-91); No Numbra (NU) test object (ASTM E803-91); MTF and Noise; parameters used in calculation; results of the experiments; summary of analysis. The resulting data consisted exposure contributors and sensitivity levels for films that were radiographed along with 0.25 and 0.5 mm Gd converters; visibility of holes and gaps on the image of the sensitivity indicator using both 0.25 and 0.5 mm Gd converters; qualitative data obtained from observation of the blurring effect on the lower boron nitride disc for both 0.25 and 0.5 mm Gd converters

  15. Metal Artifact Suppression in Dental Cone Beam Computed Tomography Images Using Image Processing Techniques.

    Science.gov (United States)

    Johari, Masoumeh; Abdollahzadeh, Milad; Esmaeili, Farzad; Sakhamanesh, Vahideh

    2018-01-01

    Dental cone beam computed tomography (CBCT) images suffer from severe metal artifacts. These artifacts degrade the quality of acquired image and in some cases make it unsuitable to use. Streaking artifacts and cavities around teeth are the main reason of degradation. In this article, we have proposed a new artifact reduction algorithm which has three parallel components. The first component extracts teeth based on the modeling of image histogram with a Gaussian mixture model. Striking artifact reduction component reduces artifacts using converting image into the polar domain and applying morphological filtering. The third component fills cavities through a simple but effective morphological filtering operation. Finally, results of these three components are combined into a fusion step to create a visually good image which is more compatible to human visual system. Results show that the proposed algorithm reduces artifacts of dental CBCT images and produces clean images.

  16. Chemical intermediate detection following corona discharge on volatile organic compounds: general method using molecular beam techniques

    International Nuclear Information System (INIS)

    He Luning; Sulkes, Mark

    2011-01-01

    Nonthermal plasma (NTP)-based treatments of volatile organic compounds (VOCs) have potential for effective environmental remediation. Theory and experiment that consider the basic science pertaining to discharge events have helped improve NTP remediation outcomes. If direct information on early post-discharge chemical intermediates were also available, it would likely lead to additional improvement in NTP remediation outcomes. To this point, however, experiments yielding direct information on post-NTP VOC intermediates have been limited. An approach using supersonic expansion molecular beam methods offers general promise for detection of post-discharge VOC intermediates. To illustrate the potential utility of these methods, we present mass spectra showing the growth of early products formed when pulsed corona discharges were carried out on toluene in He and then in He with added O 2 . Good general detection of neutral post-discharge species was obtained using 800 nm 150 fs photoionization pulses.

  17. A Monte Carlo code to optimize the production of Radioactive Ion Beams by the ISOL technique

    CERN Document Server

    Santana-Leitner, M

    2005-01-01

    Currently the nuclear chart includes around 3000 nuclides, distributed as ${\\beta}^+$, ${\\beta}^-$ and $\\alpha$-emitters, stable and spontaneously fissioning isotopes. A similar amount of unknown nuclei belongs to the so-called \\textit{terra incognita}, the uncertain region contained also within the proton, neutron and (fast) fission driplines and thereby stable against nucleon emission. The exploration of this zone is to be assisted by the use of radioactive ion beams (RIB) and could provide a new understanding of several nuclear properties. Moreover, besides pointing at crucial questions such as the validity of the shell model, the dilute matter and the halo structure, challenging experiments outside nuclear physics are also attended, e.g., explanations of the nucleosythesis processes that may justify why the matter in the universe has evolved to present proportions of elements, and which represents a major challenge to nuclear physics. These, together with other fascinating research lines in particle physi...

  18. Techniques for fabricating an infrared optical pyrometry system for pulsed electron beam diagnostics

    International Nuclear Information System (INIS)

    Ouellette, A.L.

    1976-01-01

    A description is given of an infrared optical pyrometry system which was designed to make fast time resolved temperature measurements. The purpose of this equipment is to determine the amount of energy from an electron beam or some other type of pulsed energy deposition that is absorbed in a target. The system is capable of measuring energy deposition levels up to 4000 J/g in carbon, which corresponds to a graphite target temperature of 2200 0 C. Methods of fabrication, alignment, and calibration are presented. The measurement of absorbed energy in a target as a function of position and depth is discussed as a possible application, and several measurements are described which permit a comparison of results from this system with those taken by other methods

  19. Two-beam laser fabrication technique and the application for fabricating conductive silver nanowire on flexible substrate

    Directory of Open Access Journals (Sweden)

    Gui-Cang He

    2017-03-01

    Full Text Available In this study, a two-beam laser fabrication technique is proposed to fabricate silver nanowire (AgNW on the polyethylene terephthalate (PET substrate. The femtosecond pulse laser in the technique plays a role in generating Ag nanoparticles from the silver aqueous solution by multiphoton photoreduction. The continuous wave (CW laser of the technique works as optical tweezers, and make the Ag nanoparticles gather to a continuous AgNW by the optical trapping force. The optical trapping force of the CW laser was calculated under our experimental condition. The flexibility and the resistance stability of the AgNW that fabricated by this technique are very excellent. Compared to the resistance of the AgNW without bending, the decreasing rate of the AgNW resistance is about 16% under compressed bending condition at the radius of 1 mm, and the increasing rate of the AgNW resistance is only 1.3% after the AgNW bended about 3500 times at the bending radius of 1 mm. The study indicates that the AgNW is promising for achieving flexible device and would promote the development of the flexible electronics.

  20. TH-EF-207A-04: A Dynamic Contrast Enhanced Cone Beam CT Technique for Evaluation of Renal Functions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z; Shi, J; Yang, Y [University of Miami School of Medicine, Miami, FL (United States)

    2016-06-15

    Purpose: To develop a simple but robust method for the early detection and evaluation of renal functions using dynamic contrast enhanced cone beam CT technique. Methods: Experiments were performed on an integrated imaging and radiation research platform developed by our lab. Animals (n=3) were anesthetized with 20uL Ketamine/Xylazine cocktail, and then received 200uL injection of iodinated contrast agent Iopamidol via tail vein. Cone beam CT was acquired following contrast injection once per minute and up to 25 minutes. The cone beam CT was reconstructed with a dimension of 300×300×800 voxels of 130×130×130um voxel resolution. The middle kidney slices in the transvers and coronal planes were selected for image analysis. A double exponential function was used to fit the contrast enhanced signal intensity versus the time after contrast injection. Both pixel-based and region of interest (ROI)-based curve fitting were performed. Four parameters obtained from the curve fitting, namely the amplitude and flow constant for both contrast wash in and wash out phases, were investigated for further analysis. Results: Robust curve fitting was demonstrated for both pixel based (with R{sup 2}>0.8 for >85% pixels within the kidney contour) and ROI based (R{sup 2}>0.9 for all regions) analysis. Three different functional regions: renal pelvis, medulla and cortex, were clearly differentiated in the functional parameter map in the pixel based analysis. ROI based analysis showed the half-life T1/2 for contrast wash in and wash out phases were 0.98±0.15 and 17.04±7.16, 0.63±0.07 and 17.88±4.51, and 1.48±0.40 and 10.79±3.88 minutes for the renal pelvis, medulla and cortex, respectively. Conclusion: A robust method based on dynamic contrast enhanced cone beam CT and double exponential curve fitting has been developed to analyze the renal functions for different functional regions. Future study will be performed to investigate the sensitivity of this technique in the detection

  1. Characterization of thin films and surfaces by ion-beam analytical techniques

    International Nuclear Information System (INIS)

    Pelicon, P.; Budnar, M.; Zorko, B.; Razpet, A.

    1999-01-01

    The optimization of Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA) at the tandetron facility of J. Stefan Inst.e is reported. The most recent applications of these techniques for the analysis of thin films and surfaces are presented. The construction of the isotope - resolved Time-Of-Flight ERDA telescope for depth profiling of light elements is reviewed.(author)

  2. The application of DECnet TTT technique in beam diagnostical system of SSC central region

    International Nuclear Information System (INIS)

    Zhang Guixu; Huang Tuanhua

    1997-01-01

    The DECnet TTT technique and the real time network communication based on DECnet TTT are presented. Information can be transferred between console and diagnostical system via DECnet communication, so all kinds of operation can be done on console. The working computer of HIRFL console is VAX8350

  3. Combining Acceleration Techniques for Low-Dose X-Ray Cone Beam Computed Tomography Image Reconstruction.

    Science.gov (United States)

    Huang, Hsuan-Ming; Hsiao, Ing-Tsung

    2017-01-01

    Over the past decade, image quality in low-dose computed tomography has been greatly improved by various compressive sensing- (CS-) based reconstruction methods. However, these methods have some disadvantages including high computational cost and slow convergence rate. Many different speed-up techniques for CS-based reconstruction algorithms have been developed. The purpose of this paper is to propose a fast reconstruction framework that combines a CS-based reconstruction algorithm with several speed-up techniques. First, total difference minimization (TDM) was implemented using the soft-threshold filtering (STF). Second, we combined TDM-STF with the ordered subsets transmission (OSTR) algorithm for accelerating the convergence. To further speed up the convergence of the proposed method, we applied the power factor and the fast iterative shrinkage thresholding algorithm to OSTR and TDM-STF, respectively. Results obtained from simulation and phantom studies showed that many speed-up techniques could be combined to greatly improve the convergence speed of a CS-based reconstruction algorithm. More importantly, the increased computation time (≤10%) was minor as compared to the acceleration provided by the proposed method. In this paper, we have presented a CS-based reconstruction framework that combines several acceleration techniques. Both simulation and phantom studies provide evidence that the proposed method has the potential to satisfy the requirement of fast image reconstruction in practical CT.

  4. Simple technique to achieve a natural position of the head for cone beam computed tomography

    NARCIS (Netherlands)

    Damstra, Janalt; Fourie, Zacharias; Ren, Yijin

    We developed a modified laser level technique to record the natural position of the head in all three planes of space. This is a simple method for use with three-dimensional images and may be valuable in routine craniofacial assessment.

  5. Comparison between intensity modulated radiotherapy (IMRT) and 3D tangential beams technique used in patients with early-stage breast cancer who received breast-conserving therapy

    International Nuclear Information System (INIS)

    Sas-Korczynska, B.; Kokoszka, A.; Korzeniowski, S.; Sladowska, A.; Rozwadowska-Bogusz, B.; Lesiak, J.; Dyczek, S.

    2010-01-01

    Background: The most often found complications in patients with breast cancer who received radiotherapy are cardiac and pulmonary function disorders and development of second malignancies. Aim: To compare the intensity modulated radiotherapy with the 3D tangential beams technique in respect of dose distribution in target volume and critical organs they generate in patients with early-stage breast cancer who received breast-conserving therapy. Materials and methods: A dosimetric analysis was performed to assess the three radiotherapy techniques used in each of 10 consecutive patients with early-stage breast cancer treated with breast-conserving therapy. Radiotherapy was planned with the use of all the three techniques: 3D tangential beams with electron boost, IMRT with electron boost, and intensity modulated radiotherapy with simultaneous integrated boost. Results: The use of the IMRT techniques enables more homogenous dose distribution in target volume. The range of mean and median dose to the heart and lung was lower with the IMRT techniques in comparison to the 3D tangential beams technique. The range of mean dose to the heart amounted to 0.3 - 3.5 Gy for the IMRT techniques and 0.4 - 4.3 for the tangential beams technique. The median dose to the lung on the irradiated side amounted to 4.9 - 5 Gy for the IMRT techniques and 5.6 Gy for the 3D tangential beams technique. Conclusion: The application of the IMRT techniques in radiotherapy patients with early-stage breast cancer allows to obtain more homogenous dose distribution in target volume, while permitting to reduce the dose to critical organs. (authors)

  6. Development of low energy electron beam irradiation techniques. Application to sticking adhesive

    International Nuclear Information System (INIS)

    Ito, Hisashi; Enomoto, Ichiro

    1997-01-01

    Sticking adhesives were developed by use of blend with electron beam crosslinked type stylene - isoprene block copolymer (SIS) as a basic component. The sticking adhesive has object to change from sticking to adhesion and peeling by irradiation. SIS was blended with reactive monomer and resins or alicyclic hydrocarbon as tackifier and investigated. The results showed change of peel force by irradiation was influenced by compatibility, composition and the quality of objective materials. SIS such as Kraton D1320X (Shell Co. Ltd.) and tackifier such as rosin (ROSIN) and arcone P100 (ARP) were used at the basic ratio SIS/tackifier=64. Modified urethane acrylate (UA306H), isobornyl acrylate (IBXA), epoxy ester (3002M), lauryl methacrylate (LM) and lauryl acrylate (LA) were used as monomer. The large changes of peel force were observed by blends with UA306H or 3002M of which properties were incompatibility. These results indicated that we made possible to control the peel force by irradiation by means of adding the specific incompatibility monomer to the mixture of SIS and tackifier. (S.Y.)

  7. The creation of strongly coupled plasmas using an intense heavy ion beam: low-entropy compression of hydrogen and the problem of hydrogen metallization

    Energy Technology Data Exchange (ETDEWEB)

    Tahir, N A [Institut fuer Theoretische Physik, Universitaet Frankfurt, Postfach 11 19 32, 60054 Frankfurt (Germany); Piriz, A R [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Shutov, A [Institute for Problems in Chemical Physics Research, Chernogolovka, Russia (Russian Federation); Varentsov, D [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgarten Str. 9, 64289 Darmstadt (Germany); Udrea, S [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgarten Str. 9, 64289 Darmstadt (Germany); Hoffmann, D H H [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgarten Str. 9, 64289 Darmstadt (Germany); Juranek, H [Fachbereich Physik, Universitaet Rostock, 18051 Rostock (Germany); Redmer, R [Fachbereich Physik, Universitaet Rostock, 18051 Rostock (Germany); Portugues, R F [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Lomonosov, I [Institute for Problems in Chemical Physics Research, Chernogolovka, Russia (Russian Federation); Fortov, V E [Institute for Problems in Chemical Physics Research, Chernogolovka, Russia (Russian Federation)

    2003-06-06

    Intense heavy ion beams deposit energy very efficiently over extended volumes of solid density targets, thereby creating large samples of strongly coupled plasmas. Intense beams of energetic heavy ions are therefore an ideal tool to research this interesting field. It is also possible to design experiments using special beam-target geometries to achieve low-entropy compression of samples of matter. This type of experiments is of particular interest for studying the problem of hydrogen metallization. In this paper we present a design study of such a proposed experiment that will be carried out at the future heavy ion synchrotron facility SIS100, at the Gesellschaft fuer Schwerionenforschung, Darmstadt. This study has been done using a two-dimensional hydrodynamic computer code. The target consists of a solid hydrogen cylinder that is enclosed in a thick shell of lead whose one face is irradiated with an ion beam which has an annular (ring shaped) focal spot. The beam intensity and other parameters are considered to be the same as expected at the future SIS100 facility. The simulations show that due to multiple shock reflection between the cylinder axis and the lead-hydrogen boundary, one can achieve up to 20 times solid density in hydrogen while keeping the temperature as low as a few thousand K. The corresponding pressure is of the order of 10 Mbar. These values of the physical parameters lie within the range of theoretically predicted values for hydrogen metallization. We have also carried out a parameter study of this problem by varying the target and beam parameters over a wide range. It has been found that the results are very insensitive to such changes in the input parameters.

  8. The creation of strongly coupled plasmas using an intense heavy ion beam: low-entropy compression of hydrogen and the problem of hydrogen metallization

    International Nuclear Information System (INIS)

    Tahir, N A; Piriz, A R; Shutov, A; Varentsov, D; Udrea, S; Hoffmann, D H H; Juranek, H; Redmer, R; Portugues, R F; Lomonosov, I; Fortov, V E

    2003-01-01

    Intense heavy ion beams deposit energy very efficiently over extended volumes of solid density targets, thereby creating large samples of strongly coupled plasmas. Intense beams of energetic heavy ions are therefore an ideal tool to research this interesting field. It is also possible to design experiments using special beam-target geometries to achieve low-entropy compression of samples of matter. This type of experiments is of particular interest for studying the problem of hydrogen metallization. In this paper we present a design study of such a proposed experiment that will be carried out at the future heavy ion synchrotron facility SIS100, at the Gesellschaft fuer Schwerionenforschung, Darmstadt. This study has been done using a two-dimensional hydrodynamic computer code. The target consists of a solid hydrogen cylinder that is enclosed in a thick shell of lead whose one face is irradiated with an ion beam which has an annular (ring shaped) focal spot. The beam intensity and other parameters are considered to be the same as expected at the future SIS100 facility. The simulations show that due to multiple shock reflection between the cylinder axis and the lead-hydrogen boundary, one can achieve up to 20 times solid density in hydrogen while keeping the temperature as low as a few thousand K. The corresponding pressure is of the order of 10 Mbar. These values of the physical parameters lie within the range of theoretically predicted values for hydrogen metallization. We have also carried out a parameter study of this problem by varying the target and beam parameters over a wide range. It has been found that the results are very insensitive to such changes in the input parameters

  9. A novel potential/viscous flow coupling technique for computing helicopter flow fields

    Science.gov (United States)

    Summa, J. Michael; Strash, Daniel J.; Yoo, Sungyul

    1993-01-01

    The primary objective of this work was to demonstrate the feasibility of a new potential/viscous flow coupling procedure for reducing computational effort while maintaining solution accuracy. This closed-loop, overlapped velocity-coupling concept has been developed in a new two-dimensional code, ZAP2D (Zonal Aerodynamics Program - 2D), a three-dimensional code for wing analysis, ZAP3D (Zonal Aerodynamics Program - 3D), and a three-dimensional code for isolated helicopter rotors in hover, ZAPR3D (Zonal Aerodynamics Program for Rotors - 3D). Comparisons with large domain ARC3D solutions and with experimental data for a NACA 0012 airfoil have shown that the required domain size can be reduced to a few tenths of a percent chord for the low Mach and low angle of attack cases and to less than 2-5 chords for the high Mach and high angle of attack cases while maintaining solution accuracies to within a few percent. This represents CPU time reductions by a factor of 2-4 compared with ARC2D. The current ZAP3D calculation for a rectangular plan-form wing of aspect ratio 5 with an outer domain radius of about 1.2 chords represents a speed-up in CPU time over the ARC3D large domain calculation by about a factor of 2.5 while maintaining solution accuracies to within a few percent. A ZAPR3D simulation for a two-bladed rotor in hover with a reduced grid domain of about two chord lengths was able to capture the wake effects and compared accurately with the experimental pressure data. Further development is required in order to substantiate the promise of computational improvements due to the ZAPR3D coupling concept.

  10. Determination of rare earth elements in tomato plants by inductively coupled plasma mass spectrometry techniques.

    Science.gov (United States)

    Spalla, S; Baffi, C; Barbante, C; Turetta, C; Turretta, C; Cozzi, G; Beone, G M; Bettinelli, M

    2009-10-30

    In recent years identification of the geographical origin of food has grown more important as consumers have become interested in knowing the provenance of the food that they purchase and eat. Certification schemes and labels have thus been developed to protect consumers and genuine producers from the improper use of popular brand names or renowned geographical origins. As the tomato is one of the major components of what is considered to be the healthy Mediterranean diet, it is important to be able to determine the geographical origin of tomatoes and tomato-based products such as tomato sauce. The aim of this work is to develop an analytical method to determine rare earth elements (RRE) for the control of the geographic origin of tomatoes. The content of REE in tomato plant samples collected from an agricultural area in Piacenza, Italy, was determined, using four different digestion procedures with and without HF. Microwave dissolution with HNO3 + H2O2 proved to be the most suitable digestion procedure. Inductively coupled plasma quadrupole mass spectrometry (ICPQMS) and inductively coupled plasma sector field plasma mass spectrometry (ICPSFMS) instruments, both coupled with a desolvation system, were used to determine the REE in tomato plants in two different laboratories. A matched calibration curve method was used for the quantification of the analytes. The detection limits (MDLs) of the method ranged from 0.03 ng g(-1) for Ho, Tm, and Lu to 2 ng g(-1) for La and Ce. The precision, in terms of relative standard deviation on six replicates, was good, with values ranging, on average, from 6.0% for LREE (light rare earth elements) to 16.5% for HREE (heavy rare earth elements). These detection limits allowed the determination of the very low concentrations of REE present in tomato berries. For the concentrations of REE in tomato plants, the following trend was observed: roots > leaves > stems > berries. Copyright 2009 John Wiley & Sons, Ltd.

  11. Neutron beam applications; development of texture measuring technique using 1-dimensional PSD

    Energy Technology Data Exchange (ETDEWEB)

    Park, No Jin; Lee, Moon Kyu; Joung, Tae Won; Lee, In Sung [Kumoh National University of Technology, Kumi (Korea)

    2002-03-01

    The new developed materials have often a low crystal symmetry or/and multi-phase state. Because the diffraction patterns of those materials are very complex and some peaks are overlapped, the measured pole figures with a conventional detector (0-dimensional detector) are not sufficient to use for the texture analysis. And also the widely broaden diffraction patterns caused by sever deformation, can only measured with lots of measuring errors using 0-dimensional detector. In this study the 1-dimensional and 2-dimensional position sensitive detector(PSD) is used such pattern to analyse. With PSD the more accurate pole figures can be measured, and the texture analysis, the estimation of the properties are determined more precisely. The measurement using PSD needs special technique for the analysis of the measured pattern. In this study the measuring and analysing technique is developed and compared with the conventional detector. 11 refs., 92 figs., 21 tabs. (Author)

  12. Analysis of heat and mass transfers in two-phase flow by coupling optical diagnostic techniques

    International Nuclear Information System (INIS)

    Lemaitre, P.; Porcheron, E.

    2008-01-01

    During the course of a hypothetical accident in a nuclear power plant, spraying might be actuated to reduce static pressure in the containment. To acquire a better understanding of the heat and mass transfers between a spray and the surrounding confined gas, non-intrusive optical measurements have to be carried out simultaneously on both phases. The coupling of global rainbow refractometry with out-of-focus imaging and spontaneous Raman scattering spectroscopy allows us to calculate the local Spalding parameter B M , which is useful in describing heat transfer associated with two-phase flow. (orig.)

  13. Analysis of heat and mass transfers in two-phase flow by coupling optical diagnostic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lemaitre, P.; Porcheron, E. [Institut de Radioprotection et de Surete Nucleaire, Saclay (France)

    2008-08-15

    During the course of a hypothetical accident in a nuclear power plant, spraying might be actuated to reduce static pressure in the containment. To acquire a better understanding of the heat and mass transfers between a spray and the surrounding confined gas, non-intrusive optical measurements have to be carried out simultaneously on both phases. The coupling of global rainbow refractometry with out-of-focus imaging and spontaneous Raman scattering spectroscopy allows us to calculate the local Spalding parameter B{sub M}, which is useful in describing heat transfer associated with two-phase flow. (orig.)

  14. Techniques used in CAPRI for the dosimetry of γ radiations and electron beams

    International Nuclear Information System (INIS)

    Laizier, J.

    1980-01-01

    The radiation sources of CAPRI are: Pagure - 60 Co - 20Kcie, Poseidon - 60 Co - 1MCie (presently the activity is 200 Kcie), Vulcain - e - - 3MeV (variable from 0.5 MeV) - 1mA, Promethee - e - - 300 kV - 100 mA. The activities of CAPRI are research and development in industrial applications of irradiation, pilot and small scale production, irradiation (sterilization), nuclear qualification. Dosimetry techniques are: plastic dosimetry, chemical dosimetry, films [fr

  15. Thermoelastic and Pyroelectric Couplings Effects on Dynamics and Active Control of Smart Piezolaminated Beam Modeled by Finite Element Method

    OpenAIRE

    Sanbi, M.; Saadani, R.; Sbai, K.; Rahmoune, M.

    2014-01-01

    Smart structures with integrated sensors, actuators, and control electronics are of importance to the next generation high-performance structural systems. In this study, thermopiezoelastic characteristics of piezoelectric beam continua are studied and applications of the theory to active structures in sensing and optimal control are discussed. Using linear thermopiezoelastic theory and Timoshenko assumptions, a generic thermopiezoelastic theory for piezolaminated composite beam is derived. Fi...

  16. Depth profiling of residual activity of ^{237}U fragments as a range verification technique for ^{238}U primary ion beam

    Directory of Open Access Journals (Sweden)

    I. Strašík

    2012-07-01

    Full Text Available Experimental and simulation data concerning fragmentation of ^{238}U ion beam in aluminum, copper, and stainless-steel targets with the initial energy 500 and 950  MeV/u are collected in the paper. A range-verification technique based on depth profiling of residual activity is presented. The irradiated targets were constructed in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. One of the purposes of these experiments was depth profiling of residual activity of induced nuclides and projectile fragments. Among the projectile fragments, special attention is paid to the ^{237}U isotope that has a range very close to the range of the primary ^{238}U ions. Therefore, the depth profiling of the ^{237}U isotope can be utilized for experimental verification of the ^{238}U primary-beam range, which is demonstrated and discussed in the paper. The experimental data are compared with computer simulations by FLUKA, SRIM, and ATIMA, as well as with complementary experiments.

  17. Development of accurate techniques for controlling polarization of a long wavelength neutron beam in very low magnetic fields. I

    International Nuclear Information System (INIS)

    Kawai, Takeshi; Ebisawa, Toru; Tasaki, Seiji; Akiyoshi, Tsunekazu; Eguchi, Yoshiaki; Hino, Masahiro; Achiwa, Norio.

    1995-01-01

    The purpose of our study is to develop accurate techniques for controlling polarization of a long wavelength neutron beam and to make a thin-film dynamical spin-flip device operated in magnetizing fields less than 100 gauss and in a shorter switching time up to 20 kHz. The device would work as a chopper for a polarized neutron beam and as a magnetic switching device for a multilayer neutron interferometer. We have started to develop multilayer polarizing mirrors functioning under magnetizing fields less than 100 gauss. The multilayers of Permalloy-Ge and Fe-Ge have been produced using the evaporation method under magnetizing fields of about 100 gauss parallel to the Si-wafer substrate surface. The hysteresis loop for in-plane magnetization of the multilayers were measured to discuss their feasibilities for the polarizing device functioning under very low magnetizing fields. The polarizing efficiencies of Fe-Ge and Permalloy-Ge multilayers were 95 % and 91 % with reflectivities of 50 % and 66 % respectively under magnetizing fields of 80 gauss. The report also discusses problems in applying these multilayer polarizing mirrors to ultracold neutrons. (author)

  18. Direct Trace Element Analysis of Liquid Blood Samples by In-Air Ion Beam Analytical Techniques (PIXE-PIGE).

    Science.gov (United States)

    Huszank, Robert; Csedreki, László; Török, Zsófia

    2017-02-07

    There are various liquid materials whose elemental composition is of interest in various fields of science and technology. In many cases, sample preparation or the extraction can be complicated, or it would destroy the original environment before the analysis (for example, in the case of biological samples). However, multielement direct analysis of liquid samples can be realized by an external PIXE-PIGE measurement system. Particle-induced X-ray and gamma-ray emission spectroscopy (PIXE, PIGE) techniques were applied in external (in-air) microbeam configuration for the trace and main element determination of liquid samples. The direct analysis of standard solutions of several metal salts and human blood samples (whole blood, blood serum, blood plasma, and formed elements) was realized. From the blood samples, Na, P, S, Cl, K, Ca, Fe, Cu, Zn, and Br elemental concentrations were determined. The focused and scanned ion beam creates an opportunity to analyze very small volume samples (∼10 μL). As the sample matrix consists of light elements, the analysis is possible at ppm level. Using this external beam setup, it was found that it is possible to determine elemental composition of small-volume liquid samples routinely, while the liquid samples do not require any preparation processes, and thus, they can be analyzed directly. In the case of lower concentrations, the method is also suitable for the analysis (down to even ∼1 ppm level) but with less accuracy and longer measurement times.

  19. Atmospheric pressure surface sampling/ionization techniques for direct coupling of planar separations with mass spectrometry.

    Science.gov (United States)

    Pasilis, Sofie P; Van Berkel, Gary J

    2010-06-18

    Planar separations, which include thin layer chromatography and gel electrophoresis, are in widespread use as important and powerful tools for conducting separations of complex mixtures. To increase the utility of planar separations, new methods are needed that allow in situ characterization of the individual components of the separated mixtures. A large number of atmospheric pressure surface sampling and ionization techniques for use with mass spectrometry have emerged in the past several years, and several have been investigated as a means for mass spectrometric read-out of planar separations. In this article, we review the atmospheric pressure surface sampling and ionization techniques that have been used for the read-out of planar separation media. For each technique, we briefly explain the operational basics and discuss the analyte type for which it is appropriate and some specific applications from the literature. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  20. Efficiency assessment of runoff harvesting techniques using a 3D coupled surface-subsurface hydrological model

    International Nuclear Information System (INIS)

    Verbist, K.; Cronelis, W. M.; McLaren, R.; Gabriels, D.; Soto, G.

    2009-01-01

    In arid and semi-arid zones runoff harvesting techniques are often applied to increase the water retention and infiltration on steep slopes. Additionally, they act as an erosion control measure to reduce land degradation hazards. Both in literature and in the field, a large variety of runoff collecting systems are found, as well as large variations in design and dimensions. Therefore, detailed measurements were performed on a semi-arid slope in central Chile to allow identification of the effect of a simple water harvesting technique on soil water availability. For this purpose, twenty two TDR-probes were installed and were monitored continuously during and after a simulated rainfall event. These data were used to calibrate the 3D distributed flow model HydroGeoSphere, to assess the runoff components and soil water retention as influenced by the water harvesting technique, both under simulated and natural rainfall conditions. (Author) 6 refs.

  1. Fatigue life estimation of a 1D aluminum beam under mode-I loading using the electromechanical impedance technique

    International Nuclear Information System (INIS)

    Lim, Yee Yan; Soh, Chee Kiong

    2011-01-01

    Structures in service are often subjected to fatigue loads. Cracks would develop and lead to failure if left unnoticed after a large number of cyclic loadings. Monitoring the process of fatigue crack propagation as well as estimating the remaining useful life of a structure is thus essential to prevent catastrophe while minimizing earlier-than-required replacement. The advent of smart materials such as piezo-impedance transducers (lead zirconate titanate, PZT) has ushered in a new era of structural health monitoring (SHM) based on non-destructive evaluation (NDE). This paper presents a series of investigative studies to evaluate the feasibility of fatigue crack monitoring and estimation of remaining useful life using the electromechanical impedance (EMI) technique employing a PZT transducer. Experimental tests were conducted to study the ability of the EMI technique in monitoring fatigue crack in 1D lab-sized aluminum beams. The experimental results prove that the EMI technique is very sensitive to fatigue crack propagation. A proof-of-concept semi-analytical damage model for fatigue life estimation has been developed by incorporating the linear elastic fracture mechanics (LEFM) theory into the finite element (FE) model. The prediction of the model matches closely with the experiment, suggesting the possibility of replacing costly experiments in future

  2. Fatigue life estimation of a 1D aluminum beam under mode-I loading using the electromechanical impedance technique

    Science.gov (United States)

    Lim, Yee Yan; Kiong Soh, Chee

    2011-12-01

    Structures in service are often subjected to fatigue loads. Cracks would develop and lead to failure if left unnoticed after a large number of cyclic loadings. Monitoring the process of fatigue crack propagation as well as estimating the remaining useful life of a structure is thus essential to prevent catastrophe while minimizing earlier-than-required replacement. The advent of smart materials such as piezo-impedance transducers (lead zirconate titanate, PZT) has ushered in a new era of structural health monitoring (SHM) based on non-destructive evaluation (NDE). This paper presents a series of investigative studies to evaluate the feasibility of fatigue crack monitoring and estimation of remaining useful life using the electromechanical impedance (EMI) technique employing a PZT transducer. Experimental tests were conducted to study the ability of the EMI technique in monitoring fatigue crack in 1D lab-sized aluminum beams. The experimental results prove that the EMI technique is very sensitive to fatigue crack propagation. A proof-of-concept semi-analytical damage model for fatigue life estimation has been developed by incorporating the linear elastic fracture mechanics (LEFM) theory into the finite element (FE) model. The prediction of the model matches closely with the experiment, suggesting the possibility of replacing costly experiments in future.

  3. Experimental study of laser ablation as sample introduction technique for inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Van Winckel, S.

    2001-01-01

    The contribution consists of an abstract of a PhD thesis. In the PhD study, several complementary applications of laser-ablation were investigated in order to characterise experimentally laser ablation (LA) as a sample introduction technique for ICP-MS. Three applications of LA as a sample introduction technique are discussed: (1) the microchemical analysis of the patina of weathered marble; (2) the possibility to measure isotope ratios (in particular Pb isotope ratios in archaeological bronze artefacts); and (3) the determination of Si in Al as part of a dosimetric study of the BR2 reactor vessel

  4. Mapping the Galvanic Corrosion of Three Metals Coupled with a Wire Beam Electrode: The Influence of Temperature and Relative Geometrical Position

    Science.gov (United States)

    Liu, Yun-Fei; Liu, Shu-Fa; Duan, Jin-Zhuo

    2018-01-01

    The local electrochemical properties of galvanic corrosion for three coupled metals in a desalination plant were investigated with three wire-beam electrodes as wire sensors: aluminum brass (HAl77-2), titanium (TA2), and 316L stainless steel (316L SS). These electrodes were used with artificial seawater at different temperatures. The potential and current–density distributions of the three-metal coupled system are inhomogeneous. The HAl77-2 wire anodes were corroded in the three-metal coupled system. The TA2 wires acted as cathodes and were protected; the 316L SS wires acted as secondary cathodes. The temperature and electrode arrangement have important effects on the galvanic corrosion of the three-metal coupled system. The corrosion current of the HAl77-2 increased with temperature indicating enhanced anode corrosion at higher temperature. In addition, the corrosion of HAl77-2 was more significant when the HAl77-2 wires were located in the middle of the coupled system than with the other two metal arrangement styles. PMID:29495617

  5. Mapping the Galvanic Corrosion of Three Metals Coupled with a Wire Beam Electrode: The Influence of Temperature and Relative Geometrical Position.

    Science.gov (United States)

    Ju, Hong; Yang, Yuan-Feng; Liu, Yun-Fei; Liu, Shu-Fa; Duan, Jin-Zhuo; Li, Yan

    2018-02-28

    The local electrochemical properties of galvanic corrosion for three coupled metals in a desalination plant were investigated with three wire-beam electrodes as wire sensors: aluminum brass (HAl77-2), titanium (TA2), and 316L stainless steel (316L SS). These electrodes were used with artificial seawater at different temperatures. The potential and current-density distributions of the three-metal coupled system are inhomogeneous. The HAl77-2 wire anodes were corroded in the three-metal coupled system. The TA2 wires acted as cathodes and were protected; the 316L SS wires acted as secondary cathodes. The temperature and electrode arrangement have important effects on the galvanic corrosion of the three-metal coupled system. The corrosion current of the HAl77-2 increased with temperature indicating enhanced anode corrosion at higher temperature. In addition, the corrosion of HAl77-2 was more significant when the HAl77-2 wires were located in the middle of the coupled system than with the other two metal arrangement styles.

  6. Mapping the Galvanic Corrosion of Three Metals Coupled with a Wire Beam Electrode: The Influence of Temperature and Relative Geometrical Position

    Directory of Open Access Journals (Sweden)

    Hong Ju

    2018-02-01

    Full Text Available The local electrochemical properties of galvanic corrosion for three coupled metals in a desalination plant were investigated with three wire-beam electrodes as wire sensors: aluminum brass (HAl77-2, titanium (TA2, and 316L stainless steel (316L SS. These electrodes were used with artificial seawater at different temperatures. The potential and current–density distributions of the three-metal coupled system are inhomogeneous. The HAl77-2 wire anodes were corroded in the three-metal coupled system. The TA2 wires acted as cathodes and were protected; the 316L SS wires acted as secondary cathodes. The temperature and electrode arrangement have important effects on the galvanic corrosion of the three-metal coupled system. The corrosion current of the HAl77-2 increased with temperature indicating enhanced anode corrosion at higher temperature. In addition, the corrosion of HAl77-2 was more significant when the HAl77-2 wires were located in the middle of the coupled system than with the other two metal arrangement styles.

  7. Real-time kinetic modeling of YSZ thin film roughness deposited by e-beam evaporation technique

    International Nuclear Information System (INIS)

    Galdikas, A.; Cerapaite-Trusinskiene, R.; Laukaitis, G.; Dudonis, J.

    2008-01-01

    In the present study, the process of yttrium-stabilized zirconia (YSZ) thin films deposition on optical quartz (SiO 2 ) substrates using e-beam deposition technique controlling electron gun power is analyzed. It was found that electron gun power influences the non-monotonous kinetics of YSZ film surface roughness. The evolution of YSZ thin film surface roughness was analyzed by a kinetic model. The model is based on the rate equations and includes processes of surface diffusion of the adatoms and the clusters, nucleation, growth and coalescence of islands in the case of thin film growth in Volmer-Weber mode. The analysis of the experimental results done by modeling explains non-monotonous kinetics and dependence of the surface roughness on the electron gun power. A good quantitative agreement with experimental results is obtained taking into account the initial roughness of the substrate surface and the amount of the clusters in the flux of evaporated material.

  8. External beam techniques to boost cervical cancer when brachytherapy is not an option—theories and applications

    Science.gov (United States)

    Kilic, Sarah; Khan, Atif J.; Beriwal, Sushil; Small, William

    2017-01-01

    The management of locally advanced cervical cancer relies on brachytherapy (BT) as an integral part of the radiotherapy delivery armamentarium. Occasionally, intracavitary BT is neither possible nor available. In these circumstances, post-external beam radiotherapy (EBRT) interstitial brachytherapy and/or hysterectomy may represent viable options that must be adequately executed in a timely manner. However, if these options are not applicable due to patient related or facility related reasons, a formal contingency plan should be in place. Innovative EBRT techniques such as intensity modulated and stereotactic radiotherapy may be considered for patients unable to undergo brachytherapy. Relying on provocative arguments and recent data, this review explores the rationale for and limitations of non-brachytherapy substitutes in that setting aiming to establish a formal process for the optimal execution of this alternative plan. PMID:28603722

  9. Steel research using neutron beam techniques. In-situ neutron diffraction, small-angle neutron scattering and residual stress analysis

    International Nuclear Information System (INIS)

    Sueyoshi, Hitoshi; Ishikawa, Nobuyuki; Yamada, Katsumi; Sato, Kaoru; Nakagaito, Tatsuya; Matsuda, Hiroshi; Arakaki, Yu; Tomota, Yo

    2014-01-01

    Recently, the neutron beam techniques have been applied for steel researches and industrial applications. In particular, the neutron diffraction is a powerful non-destructive method that can analyze phase transformation and residual stress inside the steel. The small-angle neutron scattering is also an effective method for the quantitative evaluation of microstructures inside the steel. In this study, in-situ neutron diffraction measurements during tensile test and heat treatment were conducted in order to investigate the deformation and transformation behaviors of TRIP steels. The small-angle neutron scattering measurements of TRIP steels were also conducted. Then, the neutron diffraction analysis was conducted on the high strength steel weld joint in order to investigate the effect of the residual stress distribution on the weld cracking. (author)

  10. Corrosion characterisation of laser beam and tungsten inert gas weldment of nickel base alloys: Micro-cell technique

    International Nuclear Information System (INIS)

    Abraham, Geogy J.; Kain, V.; Dey, G.K.; Raja, V.S.

    2015-01-01

    Highlights: • Grain matrix showed better corrosion resistance than grain boundary. • Microcell studies showed distinct corrosion behaviour of individual regions of weldment. • TIG welding resulted in increased stable anodic current density on weld fusion zone. • LB welding resulted in high stable anodic current density for heat affected zone. - Abstract: The electrochemical studies using micro-cell technique gave new understanding of electrochemical behaviour of nickel base alloys in solution annealed and welded conditions. The welding simulated regions depicted varied micro structural features. In case of tungsten inert gas (TIG) weldments, the weld fusion zone (WFZ) showed least corrosion resistance among all other regions. For laser beam (LB) weldments it was the heat-affected zone (HAZ) that showed comparatively high stable anodic current density. The high heat input of TIG welding resulted in slower heat dissipation hence increased carbide precipitation and segregation in WFZ resulting in high stable anodic current density

  11. Temperature dependence of InN film deposition by an RF plasma-assisted reactive ion beam sputtering deposition technique

    International Nuclear Information System (INIS)

    Shinoda, Hiroyuki; Mutsukura, Nobuki

    2005-01-01

    Indium nitride (InN) films were deposited on Si(100) substrates using a radiofrequency (RF) plasma-assisted reactive ion beam sputtering deposition technique at various substrate temperatures. The X-ray diffraction patterns of the InN films suggest that the InN films deposited at substrate temperatures up to 370 deg C were cubic crystalline InN; and at 500 deg C, the InN film was hexagonal crystalline InN. In a scanning electron microscope image of the InN film surface, facets of cubic single-crystalline InN grains were clearly observed on the InN film deposited at 370 deg C. The inclusion of metallic indium appeared on the InN film deposited at 500 deg C

  12. A technique for on-board CT reconstruction using both kilovoltage and megavoltage beam projections for 3D treatment verification

    International Nuclear Information System (INIS)

    Yin Fangfang; Guan Huaiqun; Lu Wenkai

    2005-01-01

    The technologies with kilovoltage (kV) and megavoltage (MV) imaging in the treatment room are now available for image-guided radiation therapy to improve patient setup and target localization accuracy. However, development of strategies to efficiently and effectively implement these technologies for patient treatment remains challenging. This study proposed an aggregated technique for on-board CT reconstruction using combination of kV and MV beam projections to improve the data acquisition efficiency and image quality. These projections were acquired in the treatment room at the patient treatment position with a new kV imaging device installed on the accelerator gantry, orthogonal to the existing MV portal imaging device. The projection images for a head phantom and a contrast phantom were acquired using both the On-Board Imager TM kV imaging device and the MV portal imager mounted orthogonally on the gantry of a Varian Clinac TM 21EX linear accelerator. MV projections were converted into kV information prior to the aggregated CT reconstruction. The multilevel scheme algebraic-reconstruction technique was used to reconstruct CT images involving either full, truncated, or a combination of both full and truncated projections. An adaptive reconstruction method was also applied, based on the limited numbers of kV projections and truncated MV projections, to enhance the anatomical information around the treatment volume and to minimize the radiation dose. The effects of the total number of projections, the combination of kV and MV projections, and the beam truncation of MV projections on the details of reconstructed kV/MV CT images were also investigated

  13. Liquid separation techniques coupled with mass spectrometry for chiral analysis of pharmaceuticals compounds and their metabolites in biological fluids.

    Science.gov (United States)

    Erny, G L; Cifuentes, A

    2006-02-24

    Determination of the chiral composition of drugs is nowadays a key step in order to determine purity, activity, bioavailability, biodegradation, etc., of pharmaceuticals. In this article, works published for the last 5 years on the analysis of chiral drugs by liquid separation techniques coupled with mass spectrometry are reviewed. Namely, chiral analysis of pharmaceuticals including, e.g., antiinflammatories, antihypertensives, relaxants, etc., by liquid chromatography-mass spectrometry and capillary electrophoresis-mass spectrometry are included. The importance and interest of the analysis of the enantiomers of the active compound and its metabolites in different biological fluids (plasma, urine, cerebrospinal fluid, etc.) are also discussed.

  14. Atomic and nuclear analytical methods. XRF, Moessbauer, XPS, NAA and ion-beam spectroscopic techniques

    International Nuclear Information System (INIS)

    Verma, H.R.

    2007-01-01

    This book is a blend of analytical methods based on the phenomenon of atomic and nuclear physics. It comprises comprehensive presentations about X-ray Fluorescence (XRF), Moessbauer Spectroscopy (MS), X-ray Photoelectron Spectroscopy (XPS), Neutron- Activation Analysis (NAA), Particle Induced X-ray Emission Analysis (PIXE), Rutherford Backscattering Analysis (RBS), Elastic Recoil Detection (ERD), Nuclear Reaction Analysis (NRA), Particle Induced Gamma-ray Emission Analysis (PIGE), and Accelerator Mass Spectrometry (AMS). These techniques are commonly applied in the fields of medicine, biology, environmental studies, archaeology or geology et al. and pursued in major international research laboratories. (orig.)

  15. The evaluation of properties for radiation therapy techniques with flattening filter-free beam and usefulness of time and economy to a patient with the radiation therapy

    International Nuclear Information System (INIS)

    Goo, Jang Hyeon; Won, Hui Su; Hong, Joo Wan; Chang, Nam Jun; Park, Jin Hong

    2014-01-01

    The aim of this study was to appraise properties for radiation therapy techniques and effectiveness of time and economy to a patient in the case of applying flattening filter-free (3F) and flattening filter (2F) beam to the radiation therapy. Alderson rando phantom was scanned for computed tomography image. Treatment plans for intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) and stereotactic body radiation therapy (SBRT) with 3F and 2F beam were designed for prostate cancer. To evaluate the differences between the 3F and 2F beam, total monitor units (MUs), beam on time (BOT) and gantry rotation time (GRT) were used and measured with TrueBeam TM STx and Surveillance And Measurement (SAM) 940 detector was used for photoneutron emitted by using 3F and 2F. To assess temporal and economical aspect for a patient, total treatment periods and medical fees were estimated. In using 3F beam, total MUs in IMRT plan increased the highest up to 34.0% and in the test of BOT, GRT and photoneutron, the values in SBRT plan decreased the lowest 39.8, 38.6 and 48.1%, respectively. In the temporal and economical aspect, there were no differences between 3F and 2F beam in all of plans and the results showed that 10 days and 169,560 won was lowest in SBRT plan. According as the results, total MUs increased by using 3F beam than 2F beam but BOT, GRT and photoneutron decreased. From above the results, using 3F beam can decrease intra-fraction setup error and risk of radiation-induced secondary malignancy. But, using 3F beam did not make the benefits of temporal and economical aspect for a patient with the radiation therapy

  16. The evaluation of properties for radiation therapy techniques with flattening filter-free beam and usefulness of time and economy to a patient with the radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Jang Hyeon; Won, Hui Su; Hong, Joo Wan; Chang, Nam Jun; Park, Jin Hong [Dept. of Radiation Oncology, Seoul national university Bundang hospital, Sungnam (Korea, Republic of)

    2014-12-15

    The aim of this study was to appraise properties for radiation therapy techniques and effectiveness of time and economy to a patient in the case of applying flattening filter-free (3F) and flattening filter (2F) beam to the radiation therapy. Alderson rando phantom was scanned for computed tomography image. Treatment plans for intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) and stereotactic body radiation therapy (SBRT) with 3F and 2F beam were designed for prostate cancer. To evaluate the differences between the 3F and 2F beam, total monitor units (MUs), beam on time (BOT) and gantry rotation time (GRT) were used and measured with TrueBeam{sup TM} STx and Surveillance And Measurement (SAM) 940 detector was used for photoneutron emitted by using 3F and 2F. To assess temporal and economical aspect for a patient, total treatment periods and medical fees were estimated. In using 3F beam, total MUs in IMRT plan increased the highest up to 34.0% and in the test of BOT, GRT and photoneutron, the values in SBRT plan decreased the lowest 39.8, 38.6 and 48.1%, respectively. In the temporal and economical aspect, there were no differences between 3F and 2F beam in all of plans and the results showed that 10 days and 169,560 won was lowest in SBRT plan. According as the results, total MUs increased by using 3F beam than 2F beam but BOT, GRT and photoneutron decreased. From above the results, using 3F beam can decrease intra-fraction setup error and risk of radiation-induced secondary malignancy. But, using 3F beam did not make the benefits of temporal and economical aspect for a patient with the radiation therapy.

  17. Optimization of the design of thick, segmented scintillators for megavoltage cone-beam CT using a novel, hybrid modeling technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Langechuan; Antonuk, Larry E., E-mail: antonuk@umich.edu; El-Mohri, Youcef; Zhao, Qihua; Jiang, Hao [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-06-15

    Purpose: Active matrix flat-panel imagers (AMFPIs) incorporating thick, segmented scintillators have demonstrated order-of-magnitude improvements in detective quantum efficiency (DQE) at radiotherapy energies compared to systems based on conventional phosphor screens. Such improved DQE values facilitate megavoltage cone-beam CT (MV CBCT) imaging at clinically practical doses. However, the MV CBCT performance of such AMFPIs is highly dependent on the design parameters of the scintillators. In this paper, optimization of the design of segmented scintillators was explored using a hybrid modeling technique which encompasses both radiation and optical effects. Methods: Imaging performance in terms of the contrast-to-noise ratio (CNR) and spatial resolution of various hypothetical scintillator designs was examined through a hybrid technique involving Monte Carlo simulation of radiation transport in combination with simulation of optical gain distributions and optical point spread functions. The optical simulations employed optical parameters extracted from a best fit to measurement results reported in a previous investigation of a 1.13 cm thick, 1016μm pitch prototype BGO segmented scintillator. All hypothetical designs employed BGO material with a thickness and element-to-element pitch ranging from 0.5 to 6 cm and from 0.508 to 1.524 mm, respectively. In the CNR study, for each design, full tomographic scans of a contrast phantom incorporating various soft-tissue inserts were simulated at a total dose of 4 cGy. Results: Theoretical values for contrast, noise, and CNR were found to be in close agreement with empirical results from the BGO prototype, strongly supporting the validity of the modeling technique. CNR and spatial resolution for the various scintillator designs demonstrate complex behavior as scintillator thickness and element pitch are varied—with a clear trade-off between these two imaging metrics up to a thickness of ∼3 cm. Based on these results, an

  18. Laser ablation inductively coupled plasma mass spectrometry. An alternative technique for monitoring 90Sr

    International Nuclear Information System (INIS)

    TsingHai Wang; Yan-Chen Lai; Yi-Kong Hsieh; Chu-Fang Wang

    2017-01-01

    Developing a rapid detection method for monitoring released 90 Sr remains a challenge to analytical chemists, particularly considering its low concentration and significant interferences in environmental samples. We proposed a concept as an alternative to detect 90 Sr on the surface of fish scales using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The high affinity of fish scales to Sr is capable of preconcentrating 90 Sr that minimizes isobaric interferences from 90 Zr + or 89 YH + , while tailing effect by abundant 88 Sr can be effectively reduced by adjusting the forward power of ICP-MS component. Adopting dried droplets of internal standards further allows a semiquantification of 90 Sr content on the surface of fish scales, which also arises an opportunity to monitoring the bioaccumulation of 90 Sr after Fukushima Daiichi nuclear disaster. (author)

  19. Hyperspectral fluorescence imaging coupled with multivariate image analysis techniques for contaminant screening of leafy greens

    Science.gov (United States)

    Everard, Colm D.; Kim, Moon S.; Lee, Hoyoung

    2014-05-01

    The production of contaminant free fresh fruit and vegetables is needed to reduce foodborne illnesses and related costs. Leafy greens grown in the field can be susceptible to fecal matter contamination from uncontrolled livestock and wild animals entering the field. Pathogenic bacteria can be transferred via fecal matter and several outbreaks of E.coli O157:H7 have been associated with the consumption of leafy greens. This study examines the use of hyperspectral fluorescence imaging coupled with multivariate image analysis to detect fecal contamination on Spinach leaves (Spinacia oleracea). Hyperspectral fluorescence images from 464 to 800 nm were captured; ultraviolet excitation was supplied by two LED-based line light sources at 370 nm. Key wavelengths and algorithms useful for a contaminant screening optical imaging device were identified and developed, respectively. A non-invasive screening device has the potential to reduce the harmful consequences of foodborne illnesses.

  20. Coupled neutronic-thermal-hydraulics analysis in a coolant subchannel of a PWR using CFD techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Felipe P.; Su, Jian, E-mail: sujian@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-07-01

    The high capacity of Computational Fluid Dynamics code to predict multi-dimensional thermal-hydraulics behaviour and the increased availability of capable computer systems are making that method a good tool to simulate phenomena of thermal-hydraulics nature in nuclear reactors. However, since there are no neutron kinetics models available in commercial CFD codes to the present day, the application of CFD in the nuclear reactor safety analyses is still limited. The present work proposes the implementation of the point kinetics model (PKM) in ANSYS - Fluent to predict the neutronic behaviour in a Westinghouse Sequoyah nuclear reactor, coupling with the phenomena of heat conduction in the rod and thermal-hydraulics in the cooling fluid, via the reactivity feedback. Firstly, a mesh convergence and turbulence model study was performed, using the Reynolds-Average Navier-Stokes method, with square arrayed rod bundle featuring pitch to diameter ratio of 1:32. Secondly, simulations using the k-! SST turbulence model were performed with an axial distribution of the power generation in the fuel to analyse the heat transfer through the gap and cladding, and its in fluence on the thermal-hydraulics behaviour of the cooling fluid. The wall shear stress distribution for the centre-line rods and the dimensionless velocity were evaluated to validate the model, as well as the in fluence of the mass flow rate variation on the friction factor. The coupled model enabled to perform a dynamic analysis of the nuclear reactor during events of insertion of reactivity and shutdown of primary coolant pumps. (author)