WorldWideScience
1

Development of magnetic separation system of magnetoliposomes  

Energy Technology Data Exchange (ETDEWEB)

The magnetic separation technology using sub-microsized ferromagnetic particle is indispensable in many areas of medical biosciences. For example, ferromagnetic particles (200-500 nm) are widely used for cell sorting in stem cell research with the use of cell surface-specific antigens. Nanosized ferromagnetic particles (10-20 nm) have been suggested as more suitable in drug delivery studies given their efficiency of tissue penetration, however, the magnetic separation method for them has not been established. One of the major reasons is that magnetic force acting on the object particles decreases drastically as a particle diameter becomes small. In this study, magnetic force acting on the targets was enhanced by the combination of superconducting magnet and ...

2009-10-15

2

Anti-cancer drug loaded iron-gold core-shell nanoparticles (Fe@Au) for magnetic drug targeting.  

Science.gov (United States)

Magnetic drug targeting, using core-shell magnetic carrier particles loaded with anti-cancer drugs, is an emerging and significant method of cancer treatment. Gold shell-iron core nanoparticles (Fe@Au) were synthesized by the reverse micelle method with aqueous reactants, surfactant, co-surfactant and oil phase. XRD, XPS, TEM and magnetic property measurements were utilized to characterize these core-shell nanoparticles. Magnetic measurements showed that the particles were superparamagnetic at room temperature and that the saturation magnetization decreased with increasing gold concentration. The anti-cancer drug doxorubicin (DOX) was loaded onto these Fe@Au nanoparticle carriers and the drug release profiles showed that upto 25% of adsorbed drug was released in 80 h. It was found that the amine (-NH2) group of DOX binds ...

2010-09-01

3

Simulation of High Power Deposition on Target Materials: Applications in Magnetic, Inertial Fusion, and High Power Plasma Lithography Devices  

International Nuclear Information System (INIS)

High power and particle deposition on target materials are encountered in many applications including magnetic and inertial fusion devices, nuclear and high energy physics applications, and laser and discharge produced plasma devices. Surface and structural damage to plasma-facing components due to the frequent loss of plasma confinement remains a serious problem for the Tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination.

2006-01-01

4

J* optimization of small aspect ratio stellarator/tokamak hybrid devices  

Energy Technology Data Exchange (ETDEWEB)

A new class of low aspect ratio toroidal hybrid stellarators is found using more general plasma confinement optimization criterion than quasi-symmetrization. The plasma current profile and shape of the outer magnetic flux surface are used as control variables to achieve near constancy of the longitudinal invariant J* on internal flux surfaces (quasi-omnigeneity), in addition to a number of other desirable physics target properties. We find that a range of compact (small aspect ratio A), high {beta} (ratio of thermal energy to magnetic field energy), low plasma current devices exist which have significantly improved confinement both for thermal as well as energetic (collisionless) particle components. With reasonable increases in magnetic field and geometric size, such devices can also be scaled to confine 3.5 MeV alpha particle orbits.

1997-12-31

5

Highly Porous, Water-Soluble, Superparamagnetic, and Biocompatible Magnetite Nanocrystal Clusters for Targeted Drug Delivery.  

Science.gov (United States)

Magnetic particles have become very promising materials for drug delivery. However, preparation of magnetite particles with high surface area, biocompatibility, strong magnetic response, and suitable particle size still remains a major challenge. In this report, magnetite nanocrystal clusters with high surface areas were fabricated through a solvothermal process by introducing ammonium acetate as a porogen and trisodium citrate as a surface modification agent. The porosity, which was controlled by the reactant concentration, has been investigated in detail. The surface area of the nanocrystal clusters was as high as 141?m(2) g(-1) . Ibuprofen, as a model drug, was entrapped into the magnetite carriers. The interfacial interaction between the carboxylic groups on the drug molecules and the carboxylate groups on the carriers enhanced the loading efficiency. Low cytotoxicity in MCF-7 ...

2011-09-27

6

J{sup {asterisk}} optimization of small aspect ratio stellarator/tokamak hybrid devices  

Energy Technology Data Exchange (ETDEWEB)

A new class of low aspect ratio toroidal hybrid stellarators is found using a more general plasma confinement optimization criterion than quasisymmetrization. The plasma current profile and shape of the outer magnetic flux surface are used as control variables to achieve near constancy of the longitudinal invariant J{sup {asterisk}} on internal flux surfaces (quasiomnigeneity), in addition to a number of other desirable physics target properties. A range of compact (small aspect ratio A), low plasma current devices have been found with significantly improved confinement, both for thermal as well as energetic (collisionless) particle components. With reasonable increases in magnetic field and geometric size, such devices can also be scaled to confine 3.5 MeV alpha particle orbits.

1998-05-01

7

Magnetic flocculation and filtration  

Energy Technology Data Exchange (ETDEWEB)

A model is available in predicting flocculation frequencies between particles of various properties under the influence of a magnetic field. This model provides a basic understanding of fundamental phenomena, such as particle-particle and particle-collector interactions, occurring in HGMF (high gradient magnetic field), and will be extended to describe experimental data of particle flocculation and filtration and predict the performance of high- gradient magnetic filters. It is also expected that this model will eventually lead to a tool for design and optimization of magnetic filters for environmental, metallurgical, biochemical, and other applications.

1996-10-01

8

Fragmentation of nuclei by particles and nuclei of intermediate and high energies  

Energy Technology Data Exchange (ETDEWEB)

The present state of investigations into the fragmentation of target nuclei by particles and nuclei of intermediate and high energies is reviewed.

1983-11-01

10

Analysis of the Semileptonic Decay D0 --> anti-K0 pi- mu+ nu  

Energy Technology Data Exchange (ETDEWEB)

This thesis describes the analysis of the semileptonic decay D{sup 0} {yields} {bar K}{sup 0} {pi}{sup -} {mu}{sup +}{nu} using FOCUS data. FOCUS is a fixed target experiment at Fermilab that studies the physics of the charm quark. Particles containing charm are produced by photon-gluon fusion from the collision of a photon beam on a BeO target. The experiment is characterized by excellent vertex resolution and particle identification. The spectrometer consists of three systems for track reconstruction (two silicon systems and one multiwire proportional chamber system) and two magnets of opposite polarity. The polarity of the magnet is such that the events of e{sup +}e{sup -} pairs produced in the target (which constitutes the main background) travel through a central opening in the detectors without interactions. ...

2004-11-01

11

Three-dimensional simulation study of compact toroid plasmoid injection into magnetized plasmas  

Energy Technology Data Exchange (ETDEWEB)

Three-dimensional dynamics of a compact toroid (CT) plasmoid, which is injected into a magnetized target plasma region is investigated by using magnetohydrodynamic (MHD) numerical simulations. It is found that the process of the CT penetration into this region is much more complicated than what has been analyzed so far by using a conducting sphere (CS) model. The injected CT suffers from a tilting instability, which grows with the similar time scale as the CT penetration. The instability is accompanied by magnetic reconnection between the CT magnetic field and the target magnetic field, which disrupts the magnetic configuration of the CT. Magnetic reconnection plays a role to supply the high density plasma initially confined in the CT magnetic field into the target region. Also, ...

1999-04-01

12

Magnetic separation of antibiotics by electrochemical magnetic seeding  

Energy Technology Data Exchange (ETDEWEB)

Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for ...

2009-03-01

13

Study of particles trapped by a magnetic field  

Science.gov (United States)

A new type of radiation which occurs when particles are accelerated in the field of a longitudinal wave and in a transverse magnetic field is studied. The characteristics of such spontaneous radiation are obtained, and the influence of collective effects on the radiation is analyzed. The application of the findings to the theory of free electron lasers is discussed. 8 references.

1986-01-01

14

Energetic constraints on the creation of cell membrane pores by magnetic particles.  

UK PubMed Central (United Kingdom)

Naturally occurring and contaminant ferromagnetic and ferrimagnetic particles have been found within or near cells, and might allow pulsed magnetic fields to create transient cell membrane opening ("pores")....Full Text Available

1996-08-01

15

Direct conversion of fusion energy into the electric one in the 'Dragon' magnetic confinement system  

International Nuclear Information System (INIS)

It is shown that recuperator in which the thermal energy of particles is transformed into electric oue under drift in crossed fields is naturally coupled with dragontype magnetic confinement system, so the recuperation process can be initiated in the dragon magnetic field. A number of questions occuring under analysis of recuperator-dragon system is considered, including the dynamics of particle transfer to the recuperator, the share of particles entering the recuperator, the effect of rotational transform and the recuperation efficiency.

16

Non-linearity and hysteresis of Hall effect in magnetorheological suspensions with conducting carrier  

Energy Technology Data Exchange (ETDEWEB)

In this article a production method of a magnetorheological suspension composed with silicon steel particles of size 0.1-0.15 mm and 4% silicon content is described. Steel particles were dispersed in a conducting carrier of a by mixture of graphite particles with size 2-5 {mu}m and cedar wood oil. The filling factor of the suspension with the silicon steel particles and with graphite particles amounted to 0.25-0.40. Samples of this suspension were placed in a rectangular vessel with electrodes and used for the investigation of the Hall effect in magnetic field with induction 0-8 T, generated by Bitter-type magnet. A non-linear dependence of Hall voltage on the induction of the applied magnetic field and a hysteresis loop of this voltage in the shape of inclined digit eight were found. The causes of the observed effects ...

2003-08-01

17

Formulation development and evaluation of metronidazole magnetic nanosuspension as a magnetic-targeted and polymeric-controlled drug delivery system  

Energy Technology Data Exchange (ETDEWEB)

A nanosuspension of magnetically tagged metronidazole was developed by the solvent displacement method coupled with ultrasonication and was evaluated for its physicochemical properties. The drug release from metronidazole magnetic nanosuspension at pH 1.2 and 7.0 shows maximum correlation coefficient for zero order and Higuchi model, respectively. The anthelmintic activity of the formulated metronidazole magnetic nanosuspension was evaluated on Indian earthworms (Pheretima poi). Metronidazole magnetic nanosuspension at a dose of 10 and 50 mg/ml shortened by 31% and 34%, respectively, the mean time to death of the earthworms when compared against a non-magnetic metronidazole suspension. Thus, the developed metronidazole magnetic nanosuspension showed potent, controlled and targeted drug action and might be a good therapeutic avenue in ...

2009-05-15

18

Loss of light charged particles by nuclear interactions in BaF[sub 2] crystals  

Energy Technology Data Exchange (ETDEWEB)

The nuclear interaction probability of light charged particles in BaF[sub 2] crystals has been studied as a function of the incident particle energy. Light charged particles were identified in charge and mass by measuring their magnetic rigidity and their time-of-flight. The percentage of particles undergoing nuclear interactions has been measured for particles of charge from Z=1 to Z=6 and the experimental data are compared with the results of a model calculation. (orig.)

1993-07-15

19

Magnetic properties of materials  

Energy Technology Data Exchange (ETDEWEB)

A number of interactions between magnetic fields and matter is reviewed. The resulting forces range in magnitude from the very large, obtained in high-energy fields, to the weak ones caused by the magnetostriction of ferromagnets. The fundamentals of these interactions are highlighted, and the examples discussed are forces on dipoles, particle alignment, magnetostrictive forces, magnetic forming, magnetic stirring, levitation melting, and magnetic pulsing of tool steels. (orig.)

2000-08-15

20

Magnetic beam position monitor  

Energy Technology Data Exchange (ETDEWEB)

Many nondestructive beam position monitors are known. However, these devices can not be used for DC particle beam diagnostics. We investigated a method of beam diagnostics applicable for the operative control of DC high power e-beam inside closed waveguide. A design of the detector for determination of{open_quote} center of mass {close_quote} position of DC particle beam was developed. It was shown that the monitor can be used as a nondestructive method for the beam position control in resonators. Magnetic field of the particle beam outside a resonator is used. The detector consists of the steel yokes and magnetic field sensors. The sensors measure magnetic fluxes in the steel yokes fixed outside the resonator. When the particle beam changes its position, these magnetic fluxes also change. Beam displacement sensitivity ...

1995-12-31

21

A principle of charged particle trapping by RF electromagnetic field in the spherical cavity  

Energy Technology Data Exchange (ETDEWEB)

A new principle of particle trapping in the simple spherical cavity using both electric and magnetic components of radiofrequency electromagnetic field is proposed. The electric component of H {sub 12} oscillating mode drives the fast particle oscillations, while the magnetic component synchronously bends the trajectories to the cavity center. A specially developed theory of particle stability predicts dense and energetic electron cluster in the trap. Numerical simulations of particle dynamics in the complete electromagnetic field taking into account both space charge and particle-induced magnetic field are in good agreement with the analytic results, giving a density of 2.6*10{sup 1} electrons/cm{sup 3} and an average kinetic energy of around 30 keV at an operating frequency of 3 GHz. Being used at lower frequency, ...

2005-11-21

22

A He-gas Cooled, Stationary Granular Target  

CERN Document Server

In the CERN approach to the design of a neutrino factory, the repetition frequency of the proton beam is high enough to consider stationary solid targets as a viable solution for multi-MW beams. The target consists of high density tantalum spheres of 2 mm diameter which can efficiently be cooled by passing a high mass flow He-gas stream through the voids between the Ta-granules. Very small thermal shocks and stresses will arise in this fine grained structure due to the relatively long burst of 3.3 ms from the SPL-proton linac. In a quadruple target system where each target receives only one quarter of the total beam power of 4 MW, conservative temperature levels and adequate lifetimes of the target are estimated in its very high radiation environment. A conceptual design of the integration of the target into the magnetic horn-pion-collector ...

2003-01-01

23

Integral cross sections of 50.5 MeV #alpha# particle inelastic scattering on 1p and (2s-1d) shell nuclei and scattering mechanisms  

International Nuclear Information System (INIS)

Obtained experimental data on integral cross sections (ICS) of inelastic scattering of 50.5 MeV #alpha# particles with the excitation of "6","7Li, "9Be, "1"2","1"3C, "1"4C, "1"4N, "2"0Ne, "2"4Mg, "2"8Si nucleus low-lying energy levels are discussed. Regularities, detected in the behaviour of ICS forward scattering for 20-90 deg angles and backscattering for 90-160 deg angles for the target-nucleus under investigation are considered. Effect of reaction open channel number on #alpha#-particle scattering ICS where n,p,d- and #alpha#-channels were considered as the main channels for all the target-nuclei, is discussed. Dependence of #alpha#-particle scattering ICS on the target-nucleus level excitation energy and dependences of reaction open channel number on the channel spin, calculated for 50.5 MeV #alpha# particles and different ...

24

Concept of Plasma Spraying System for Solid Oxide Fuel Cell: Heating Studies of YSZ Particle in Plasma Jet  

International Nuclear Information System (INIS)

One of several methods to build YSZ electrolyte of SOFC is plasma spraying. This system heats particle to a melting point and then pushing them into target and forming a deposition. This paper presents heating studies of YSZ particle in plasma jet. By simple model it is shown that the required time such those YSZ particle with grain size of 50 ?m to be melt is around 12 x 10-4 second. (author)

2006-07-01

25

Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisher"T"M magnetic particle processor prior to genome sequencing  

International Nuclear Information System (INIS)

Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisher"T"M magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisher"T"M magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification.

26

The Baikal Neutrino Telescope: Selected Physics Results  

CERN Document Server

We present results on searches for exotic particles (relativistic magnetic monopoles and WIMPs) and for UHE neutrinos, obtained with the Baikal neutrino telescope NT200.

2007-01-01

27

Introduction to dualities in gauge theories  

Energy Technology Data Exchange (ETDEWEB)

These notes present a pedagogical introduction to magnetic monopoles, supersymmetry and dualities in gauge theories. They are based on lectures given at the X Jorge Andre Swieca Summer School on Particles and Fields. (author)

2000-12-01

28

Anisotropic Nd{endash}Fe{endash}B bonded magnets made from HDDR powders (invited)  

Energy Technology Data Exchange (ETDEWEB)

Anisotropic Nd{endash}Fe{endash}B magnet powders can be produced by the hydrogenationdecomposition-desorption-recombination (HDDR) process from Nd{endash}Fe@ xnB{endash}Co{endash}M ({ital M}=Ga, Zr, Nb, Hf, and Ta) alloys. The present status of those HDDR powders and the bonded magnets made from them are reviewed with regards to the powder particle size dependence of their magnetic properties, their magnetic thermal stability, and their magnetization behavior. The results of a mechanistic study on the recombination step are also presented. The magnetic properties of the anisotropic HDDR powder depend relatively little on the powder particle size. Bonded magnets with a density of {approximately}6.20 g/cm{sup 3} and a BH{sub max} of 18.5{endash}20.5 MGOe can be produced from anisotropic HDDR powders ...

1996-04-01

29

Numerical study of Cosmic Ray Diffusion in MHD turbulence  

CERN Document Server

We study diffusion of Cosmic Rays (CRs) in turbulent magnetic fields using test particle simulations. Electromagnetic fields are produced in direct numerical MHD simulations of turbulence and used as an input for particle tracing, particle feedback on turbulence being ignored. Statistical transport coefficients from the test particle runs are compared with earlier analytical predictions. We find qualitative correspondence between them in various aspects of CR diffusion. In the incompressible case, that we consider in this paper, the dominant scattering mechanism occurs to be the non-resonant mirror interactions with the slow-mode perturbations. Perpendicular transport roughly agrees with being produced by magnetic field wandering.

2010-01-01

30

Coupling of magnetostriction and electrostriction in the porous rheological composite  

Energy Technology Data Exchange (ETDEWEB)

The production method of the elastic composite containing ferrous particles and titanium barium particles dispersed in the porous silicone matrix is described in this article. Since it contains ferrous and titanium barium particles, this composite shows magnetorheological and also electrorheological properties. The electrostriction of composite samples in the electric field with maximal intensity 1.5x10{sup 6} V/m was investigated. The magnetostriction in the magnetic field with maximal induction 1 T was also investigated. It was found that samples elongate with increased electric field intensity, and the magnetic field induction was detected. By increasing the samples' elongation with increase of ferrous particles, titanium barium particles and pores number were also detected. In the investigated division of the electric and ...

2008-08-15

31

Advances in beam physics and technology: Colliders of the future  

International Nuclear Information System (INIS)

Beams may be viewed as directed and focussed flow of energy and information, carried by particles and electromagnetic radiation fields (ie, photons). Often, they interact with each other (eg, in high energy colliders) or with other forms of matter (eg, in fixed targets, sychrotron radiation, neutron scattering, laser chemistry/physics, medical therapy, etc.). The whole art and science of beams revolve around the fundamental quest for, and ultimate implementation of, mechanisms of production, storage, control and observation of beams -- always directed towards studies of the basic structures and processes of the natural world and various practical applications. Tremendous progress has been made in all aspects of beam physics and technology in the last decades -- nonlinear dynamics, superconducting magnets and rf cavities, beam instrumentation and control, novel concepts and collider praradigms, to name a few. We illustrate ...

1994-11-14

32

FEA Analysis of AP-0 Target Hall Collection Lens (Current Design)  

Energy Technology Data Exchange (ETDEWEB)

The AP-0 Target Hall Collection Lens is a pulsed device which focuses anti-protons just downstream of the Target. Since the angles at which the anti-protons depart the Target can be quite large, a very high focusing strength is required to maximize anti-proton capture into the downstream Debuncher Ring. The current design of the Collection Lens was designed to operate with a focusing gradient of 1,000 T/m. However, multiple failures of early devices resulted in lowering the normal operating gradient to about 750 T/m. At this gradient, the Lens design fares much better, lasting several million pulses, but ultimately still fails. A Finite Element Analysis (FEA) has been performed on this Collection Lens design to help determine the cause and/or nature of the failures. The Collection Lens magnetic field is created by passing high current through a central conductor cylinder. A uniform current distribution ...

2001-06-22

33

Particle emission from low energy proton bombardment of TiH{sub 2} and TiD{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

TiH{sub 2} and TiD{sub 2} thick targets were bombarded with 100 to 200 keV protons. Evidence for nuclear reactions was obtained by means of a surface barrier particle detector. Proton irradiation of TiD{sub 2} produced the following observations: {alpha} particle emission identified as (p, {alpha}) reactions from {sup 11}B and {sup 7}Li impurities in the target at ppm concentrations; and {approx}3 MeV proton and {approx}1 MeV triton emission from secondary D-D reactions caused by elastic scattering of the primary proton with a target deuteron. A 3.9 MeV {alpha} particle peak measured by others was not observed. (author)

2002-03-01

34

Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler  

Energy Technology Data Exchange (ETDEWEB)

The centroid and envelope dynamics of a high-intensity charged particle beam are investigated as a beam smoothing technique to achieve uniform illumination over a suitably chosen region of the target for applications to ion-beam-driven high energy density physics and heavy ion fusion. The motion of the beam centroid projected onto the target follows a smooth pattern to achieve the desired illumination, for improved stability properties during the beam-target interaction. The centroid dynamics is controlled by an oscillating "wobbler", a set of electrically-biased plates driven by RF voltage. __________________________________________________

2010-04-28

35

Synthesis of magnetic particles via a cationic-anionic surfactant vesicle method  

Energy Technology Data Exchange (ETDEWEB)

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe{sup 3+} and Fe{sup 2+}) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

2006-10-15

36

Synthesis of magnetic particles via a cationic-anionic surfactant vesicle method  

International Nuclear Information System (INIS)

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe"3"+ and Fe"2"+) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

2006-10-01

37

ISDD: A Computational Model of Particle Sedimentation, Diffusion and Target Cell Dosimetry for In Vitro Toxicity Studies  

Energy Technology Data Exchange (ETDEWEB)

Background: The difficulty of directly measuring cellular dose is a significant obstacle to application of target tissue dosimetry for nanoparticle and microparticle toxicity assessment. As a consequence, the target tissue paradigm for dosimetry and hazard assessment of nanoparticles has largely been ignored in favor of using metrics of exposure (e.g. ?g particle/mL culture medium, particle surface area/mL, particle number/mL). We have developed a computational model of solution particokinetics (sedimentation, diffusion) and dosimetry for non-interacting spherical particles and their agglomerates in monolayer cell culture systems. Particle transport to cells is calculated by simultaneous solution of Stokes Law (sedimentation) and the Stokes-Einstein equation (diffusion). Results: The In vitro Sedimentation, Diffusion and Dosimetry model ...

2010-11-30

38

Development program for magnetically assisted chemical separation: Evaluation of cesium removal from Hanford tank supernatant  

International Nuclear Information System (INIS)

Magnetic particles (MAG*SEP"S"M) coated with various absorbents were evaluated for the separation and recovery of low concentrations of cesium from nuclear waste solutions. The MAG*SEP"S"M particles were coated with (1) clinoptilolite, (2) transylvanian volcanic tuff, (3) resorcinol formaldehyde, and (4) crystalline silico-titanate, and then were contacted with a Hanford supernatant simulant. Particles coated with the crystalline silico-titanate were identified by Bradtec as having the highest capacity for cesium removal under the conditions tested (variation of pH, ionic strength, cesium concentration, and absorbent/solution ratio). The MAG*SEP"S"M particles coated with resorcinol formaldehyde had high distribution ratios values and could also be used to remove cesium from Hanford supernant simulant. Gamma irradiation studies were performed on the MAG*SEP"S"M ...

1994-05-09

39

Experimental and evaluated nuclear plus interference cross sections for light charged particles  

Energy Technology Data Exchange (ETDEWEB)

Experimental and evaluated integral parameters derived from nuclear plus interference differential elastic scattering cross sections are presented for all projectile/target combinations of the particles p, d, t, /sup 3/He, and ..cap alpha... The data include reaction rates, average fractional energy losses per collision and per unit path length, and average laboratory scattering cosines. The resulting parameters are of potential use in analysis of charged-particle transport.

1980-07-04

40

Mechanical variations of diffused plasma parameters in a double plasma device  

International Nuclear Information System (INIS)

Experimentally it is shown that a movable grounded metallic plate placed inside a multi-dipole magnetic cage can vary the diffused plasma parameters such as density, plasma potential and electron temperature. Plasma is solely produced in the source section of a double plasma device by a dc hot filament discharge and a low-density plasma is produced in the target section by local ionization of neutral gas by the high energetic electrons coming from the source section. A grounded movable stainless steel plate is inserted in the target section of the device. The floating potential of the plate also changes depending on the position of the plate inside the magnetic cage.

2007-06-21

41

An identification method of positron production in laser beam interaction with targets  

Energy Technology Data Exchange (ETDEWEB)

A simple electromagnetic transport system was constructed to identify very rare positrons produced in a powerful laser beam interaction with a target. Testing experiments were carried out with CO[sub 2]-laser (10[sup 12] W/cm[sup 2]) beam pulses ([tau] = 50 ns, f = 0.01 Hz) focused on the copper target, as well as with a 96 MeV alpha-particle beam irradiated carbon target. The results showed that the developed system could be effectively used for positron identification and evaluation of their energy by means of a time-of-flight method. The computerized system to deal with this problem, together with others related to the power laser beam interaction with targets, has been constructed. (orig.).

1992-10-01

42

Motion compensation with a scanned ion beam: a technical feasibility study  

UK PubMed Central (United Kingdom)

BackgroundIntrafractional motion results in local over- and under-dosage in particle therapy with a scanned beam. Scanned beam delivery offers the possibility to compensate target...Full Text Available

43

The impact of solar flares and magnetic storms on humans  

International Nuclear Information System (INIS)

Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field ...

44

Radioisotope production in the I.Ph.P.E. cyclotron for medical application  

International Nuclear Information System (INIS)

The production methods for seven radioisotopes, Ga-67, Sr-85, Pd-103, In-111, Tu-167, Hg-197 and Pb-203, by using a classical 1.5m cyclotron in the Institute of Physics and Power Engineering, Obninsk, USSR, are described. At present, more than 50 cyclotrons in different countries are used for the production of radioisotopes applied to medicine. Radioisotopes are produced with the cyclotron in the I.Ph.P.E. in the form of irradiated targets, which are delivered to Moscow radiopharmaceutical factory, where radiopharmaceuticals are produced on the base of these targets. The cyclotron is operated in two regimes providing the acceleration of protons, deuterons and alpha -particles. Two types of target assemblies are used for irradiation, the one is intended for the internal beam, and the other is for the external beam. The reactions used for the production of seven radioisotopes described above, the types of ...

45

Radioisotope production in the I. Ph. P. E. cyclotron for medical application  

Energy Technology Data Exchange (ETDEWEB)

The production methods for seven radioisotopes, Ga-67, Sr-85, Pd-103, In-111, Tm-167, Hg-197 and Pb-203, by using a classical 1.5m cyclotron in the Institute of Physics and Power Engineering, Obninsk, USSR, are described. At present, more than 50 cyclotrons in different countries are used for the production of radioisotopes applied to medicine. Radioisotopes are produced with the cyclotron in the I.Ph.P.E. in the form of irradiated targets, which are delivered to Moscow radiopharmaceutical factory, where radiopharmaceuticals are produced on the base of these targets. The cyclotron is operated in two regimes providing the acceleration of protons, deuterons and alpha -particles. Two types of target assemblies are used for irradiation, the one is intended for the internal beam, and the other is for the external beam. The reactions used for the production of seven radioisotopes described above, the types of ...

1982-01-01

46

The HARP experiment first physics results  

CERN Document Server

The HARP experiment at CERN is performing extensive measurements of hadron production cross sections and secondary particle yields, in the momentum range 1.5-15 GeV/c, over the full solid angle and using a large set of cryogenic and solid targets. First measurements of hadron production cross-sections in the forward region are reported using an aluminium target 5% of an interaction length thick and a proton beam of 12.9 GeV/c. A preliminary analysis in the large angle region of elastic scattering events produced with the cryogenic hydrogen target at 3 GeV/c beam momentum is also presented.

2005-01-01

47

Radiation-hardening of magnet coils  

International Nuclear Information System (INIS)

The first essential before embarking on the radiation-hardening of electrical insulation - mostly magnet coils - in any beam line application is to obtain a reliable estimate of the dose to the components. These are examples ( switchyards at SLAC and LAMPF) where the degree of hardness specified was much higher than was required. Although experience shows that the cost premium for substantial radiation - hardening is of the order of 10%, it has also become clear that well - designed beam line have negligible losses: hardening is required only in the vicinity of targets, collimators or other beam - intercepting devices. Where the beam is deliberately scraped, local shielding will minimize the associated radiation in the surroundings. Electron machines have their own special problems due to synchrotron radiation, so certainly coils and other electrical equipment should be kept away from the beam bend - plane. Because proton beams interact with ...

1989-03-01

48

Precipitation of ions induced by nonadiabatic motion in the outer cusp region  

Science.gov (United States)

The transport of magnetospheric particles in the outer cusp region is examined by means of three-dimensional single particle codes. It is shown that, at high altitudes, particles can experience nonadiabatic motions leading to significant magnetic moment changes. It is demonstrated that this nonadiabatic behavior can be interpreted, at least partly, by the action of an impulsive centrifugal force perturbing the particle gyromotion. Systematic trajectory calculations reveal that plasma sheet ions which ExB convert toward the magnetopause from low L-shells in the dayside sector are subjected to such nonadiabatic motions. As a result of magnetic moment damping, a number of them are injected into the loss cone and subsequently precipitate near the cusp equatorward edge.

49

Critical superparamagnetic/single-domain grain sizes in interacting magnetite particles: implications for magnetosome crystals  

UK PubMed Central (United Kingdom)

Magnetotactic bacteria contain chains of magnetically interacting crystals (magnetosome crystals), which they use for navigation (magnetotaxis). To improve magnetotaxis efficiency, the magnetosome crystals...Full Text Available

2009-12-06

50

The influence of chemically active gas on the light emission of metallic targets bombarded by positive ions  

International Nuclear Information System (INIS)

The introduction of oxygen in the vicinity of a metallic target surface, bombarded with positive argon ions of twenty kiloelectron-volts, increases the number of sputtered atoms in the excited state. This phenomenon of exaltation, very sensitive in the case of nickel and aluminium, is much less marked in the case of molybdenum. Moreover, the emission of excited particles coming from the beam's ions is not modified. A quantum-mechanical model of a kinetic emission process, which permits the interpretation of the clean metallic target's emission phenomena, seems insufficient to explain all of the results obtained in the presence of oxygen. In this last case one can therfore use a thermodynamic model in which excited metallic particles can be formed directly by chemical surface reactions of neutralization or reduction. (orig.).

51

Analysis of neutron emission spectra for 30-50 MeV #alpha#-particle induced reactions in thick targets  

International Nuclear Information System (INIS)

Comparisons of calculated neutron yield distributions from #alpha#-particle induced reactions on thick targets are made with measured data to analyze the initial reaction process in the framework of the exciton (hybrid) model code ALICE91 (M. Blann, Lawrence Livermore National Laboratory Report UCID 19614, 1982). We have considered two reaction mechanisms: dissolution of the #alpha# in the nuclear field, and preequilibrium processes initiated by #alpha#-nucleon collisions. Both these processes seem to contribute to the emitted neutron spectra in varying proportions depending on the incident #alpha# energy and possibly on the target nucleus. Contributions from other processes appear to be non-negligible.

2003-06-01

52

The study of 25 MeV alpha particle elastic scattering from a wide range of targets from "4"4Ca to "9"4Zr  

International Nuclear Information System (INIS)

The elastic scattering angular distributions of 25 MeV alpha particles scattered from "7"3Ge, "8"9Y, "9"0Zr, "9"1Zr"9"4Zr, "9"3Nb, "4"4Ca and "4"5Sc have been measured experimentally, and fitted using a conventional optical model. (author).

53

Dependence of differential cross sections of 100-150 MeV #alpha#-particle elastic scattering on "4"0Ca on character of nucleon density distribution in nucleus  

International Nuclear Information System (INIS)

A theoretical model is proposed for analyzing elastic scattering of 100-150 MeV #alpha#-particles on intermediate mass nuclei. It is shown that, within the scope of this model accounting for inhomogeneous target-nucleus density, an anomalous growth of differential cross section of elastic scattering in the region of average angles can be explained.

54

Blob transport in the plasma edge. A review  

International Nuclear Information System (INIS)

A brief review is presented of transport in the boundary region of magnetized plasmas by blob-like filaments. Such structures have enhanced levels of particles and heat, are elongated along the magnetic field lines and are localized in the drift plane across the field. The motion of an isolated blob structure is described in some detail and the contribution of such filaments to turbulence-driven transport are discussed. Results are presented from numerical simulations and probe measurements in tokamak plasmas. An interpretation is given of the measured dependence of particle density and transport on experimental control parameters in the scrape-off layer. (author)

2009-05-01

55

Novelty, preparation, characterization and enhancement of magnetic properties of Mn nanoferrites using safety binder (egg white)  

British Library Electronic Table of Contents (United Kingdom)

Nanocrystalline MnFe"2O"4 ferrite was prepared by using autocombustion technique (flash). The microstructure and magnetic properties are studied. The results of XRD and TEM clarified that, this ferrite is nanosized with particle size (39 nm). Magnetic measurements showed a ferromagnetic behavior with T"C = 613 K, the saturation magnetization M"s = 13.71 emu/g, remanent magnetization M"r = 0.1694 emu/g and, coercivity H"c = 25.6 Oe. Natural material, egg white used as an aqueous medium to extend prepare nanoparticles better than other chemical interesting materials.

2011-01-01

56

Preparation of a "6"2Zn-"6"2Cu generator and of "6"1Cu following alpha particle irradiation of a nickel target  

International Nuclear Information System (INIS)

The "6"2Zn-"6"2Cu generator system is one of the few which yield a pure positron emitting daughter. The authors have developed a method for the preparation of this generator system following 32 MeV #alpha# particle bombardment of nickel targets. The chemical processing involves two stages: first a hydrous zirconium oxide column is used at pH 4-5 to separate the zinc and copper activities produced in the target nickel, and secondly, a conventional anion exchange column is used to retain the "6"2Zn and remove all copper activities in 2M HCl. This column serves as the "6"2Cu generator which will yield pure "6"2Cu repeatedly, free from "6"2Zn and other impurities, in a mixture of HCl and NaCl. A method is outlined also to obtain a solution of "6"2Zn using the hydrous zirconium oxide (HZO) column. "6"1Cu can be prepared as a by-product in the above procedure, but a method for the preparation of "6"1Cu alone using an 18 MeV ...

57

Prediction of drug particle size and content uniformity in low-dose solid dosage forms  

British Library Electronic Table of Contents (United Kingdom)

Drug particle size distribution has a profound impact to the content uniformity in low-dose solid drug products. We derived theoretically the skewness of potency distribution as a function of particle size distribution and target dose. It was demonstrated that both skewness and coefficient of variation diverge simultaneously with inverse square root of the target dose. This scaling relation was observed in recent experiment and was verified by Monte Carlo (MC) simulation, which was employed for the first time to solve for the full potency distribution from a random retrieving model. When tested against the criteria from USP uniformity of dosage units, MC simulation showed a striking anisotropic distribution of the data. This suggests a full-scale consideration of the potency distribu...

2010-01-01

58

On some mechanisms of 27.2 MeV #alpha#-particle interaction with carbon nuclei  

International Nuclear Information System (INIS)

Using U-120 cyclotron in the course of correlation experiment one studied mechanisms of excitation and decay of "1"2C nucleus states resulting from irradiation of deuterium-polyethylene target by 27.2 MeV energy #alpha#-particle beam via recording of #alpha#-#alpha#-coincidence simultaneously with investigations of #alpha# + d-interactions. Production of "1"2C excited states decaying with the escape of #alpha#-particle and "8Be nucleus in the ground and the excited states is the basic mechanism of the studied #alpha# + "1"2C interaction

2001-05-01

59

Alpha-particle scattering from Ca-nuclei  

International Nuclear Information System (INIS)

The possibilities, advantages, and difficulties of determining nuclear matter densities by elastic scattering of alpha-particles are generally discussed. On the basis of particular experimental data - 104 MeV alpha-particle scattering from "4"0,"4"2,"4"4,"4"8Ca - a refined folded potential is introduced using a density-dependent alpha-nucleon-interaction and target nucleus densities described by Fourier-Bessel-series. Thereby, the total nucleon densities of these isotopes were determined with little model dependence. The resulting root-mean-square radii and density differences are compared with other experimental results obtained by different methods. (orig.).

1979-07-01

60

Indirect evidence for the existence of tachyons; a unified approach to the pion #-># muon #-># electron conversion problem  

International Nuclear Information System (INIS)

Using the experimentally determined cutoff energies of the muon-electron and the pion-electron conversion curves in a tachyon-bradyon model of the electron and the muon, the magnetic moments of these particles have been derived and found to be the Bohr magnetons identically. The tachyons, being bound to the bradyons and unable to drop below the speed of light, cause the bradyons to revolve in an orbit. It is this orbital motion of the charged bradyons that generates the magnetic moments.

61

MITL - A 2-D code to investigate electron flow through non-uniform field region of magnetically insulated transmission lines  

Science.gov (United States)

Self-magnetically insulated, high-voltage transmission lines are used in inertial confinement fusion particle accelerators in order to transmit power from the vacuum insulator to the diode. This paper describes a time-dependent 2-D code (MITL) for calculating (for planar or triplate geometries) the motion of test electrons through the tapered input or output convolutes of such lines. MITL results show that the electron canonical momentum in the direction of the flow changes as the electron passes through the convoluted geometry; it is suggested that these electrons lead to losses observed in long self-magnetically insulated lines.

1979-01-01

62

Final technical report for ''Frontiers in Plasma Kinetic Theory''  

International Nuclear Information System (INIS)

This report summarizes the results and activities funded by this three-year award. The principal goal of this project was to determine the thermal conductivity in clusters of galaxies. Intracluster plasmas possess chaotic magnetic fields. Since charged particles are constrained to move primarily along magnetic field lines, the topology of intracluster magnetic fields slows particle diffusion relative to the non-magnetized case, thereby reducing the thermal conductivity. Our first approach to this problem was to employ the static-magnetic-field approximation. In reality, intracluster magnetic field lines are constantly moving, since they are advected by turbulent intracluster motions. The turbulent velocities, however, are much smaller than the rapid speeds of thermal electrons, which make the dominant contribution to the ...

2007-02-01

63

Suppression of the transverse scattering amplitude in /sup 207/Pb  

Energy Technology Data Exchange (ETDEWEB)

Transverse form factors have been extracted for the low-lying neutron hole (particle) states of /sup 207/Pb from inelastic-electron-scattering data. A systematic, multipolarity-and momentum-transfer-independent quenching of approx.55% in the transverse amplitude is observed when compared with single particle predictions for both electric and magnetic transitions. The magnitude of the observed effect is not readily explained by our present theoretical understanding of this nucleus.

1980-07-14

64

Electromagnetic effects in relativistic electron beam plasma interactions  

Energy Technology Data Exchange (ETDEWEB)

Electromagnetic effects excited by intense relativistic electron beams in plasmas are investigated using a two-dimensional particle code. The simulations with dense beams show large magnetic fields excited by the Weibel instability as well as sizeable electromagnetic radiation over a significant range of frequencies. The possible relevance of beam plasma instabilities to the laser acceleration of particles is briefly discussed. 6 refs., 4 figs.

1985-02-13

65

AUTOMATED TECHNOLOGY KNOWLEDGE BASE  

Science.gov (United States)

MAGNETIC FORMING .............. MAGNETIC INDUCTION ............ MAGNETIC MATERIALS ............ MAGNETIC MEASUREMENT .......... MAGNETIC PERMEABILITY . ...

66

The giant linear magnetostriction in elastic ferromagnetic composites within a porous matrix  

Energy Technology Data Exchange (ETDEWEB)

In this article, a method of producing elastic ferromagnetic composite containing particles of chemical pure iron with sizes of 0.10-0.15 mm was described. The particles were dispersed in an elastic matrix of an elastic silicone rubber. The filling factor of composite by ferromagnetic particles and porous factors were changed in the range from 0.15 to 0.45. The samples of the obtained composite were placed in the magnetic field with induction of 0-8 T, produced by the Bitter-type magnet. The longitudinal magnetostriction of samples was measured by using a coaxial capacitor with a movable plate. It was found that the maximal relative elongation of samples was 4.81% and hysteresis of magnetostriction and also remanent magnetostriction amounted to 1.08%. A slow decay of remanent magnetostriction up to 0.14% in 10{sup 5} s was also observed.

2006-06-15

67

A MODEL OF THE SPECTRAL EVOLUTION OF PULSAR WIND NEBULAE  

International Nuclear Information System (INIS)

We study the spectral evolution of pulsar wind nebulae (PWNe) taking into account the energy injected when they are young. We model the evolution of the magnetic field inside a uniformly expanding PWN. Considering time-dependent injection from the pulsar and coolings by radiative and adiabatic losses, we solve the evolution of the particle distribution function. The model is calibrated by fitting the calculated spectrum to the observations of the Crab Nebula at an age of a thousand years. The spectral evolution of the Crab Nebula in our model shows that the flux ratio of TeV #gamma#-rays to X-rays increases with time, which implies that old PWNe are faint in X-rays, but not in TeV #gamma#-rays. The increase of this ratio is because the magnetic field decreases with time and is not because the X-ray emitting particles are cooled more rapidly than the TeV #gamma#-ray emitting ...

2010-06-01

68

Applications of Magnetic PsiDO Techniques to Space-adiabatic Perturbation Theory  

CERN Document Server

In this review, we show how advances in the theory of magnetic pseudodifferential operators (magnetic $\\Psi$DO) can be put to good use in space-adiabatic perturbation theory (SAPT). As a particular example, we extend results of [PST03] to a more general class of magnetic fields: we consider a single particle moving in a periodic potential which is subjectd to a weak and slowly-varying electromagnetic field. In addition to the semiclassical parameter $\\eps \\ll 1$ which quantifies the separation of spatial scales, we explore the influence of additional parameters that allow us to selectively switch off the magnetic field. We find that even in the case of magnetic fields with components in $C_b^{\\infty}(\\R^d)$, e. g. for constant magnetic fields, the results of Panati, Spohn and Teufel hold, i.e. to each isolated family of Bloch bands, ...

2010-01-01

69

Images of very high energy cosmic ray sources in the Galaxy: I. A source towards the galactic centre  

Energy Technology Data Exchange (ETDEWEB)

Recent analyses of the anisotropy of cosmic rays at 10{sup 18} eV (the AGASA and SUGAR data) show significant excesses from regions close to the galactic centre and Cygnus. Our aim is to check whether such anisotropies can be caused by single sources of charged particles. We investigate propagation of protons in two models of the galactic regular magnetic field (with the irregular component included) assuming that the particles are injected by a short-lived discrete source lying in the direction of the galactic centre. We show that apart from a prompt image of the source, the regular magnetic field may cause delayed images at quite large angular distances from the actual source direction. The image is strongly dependent on the time elapsed after ejection of particles and it is also very sensitive to their energy. For the most favourable conditions for particle ...

2002-08-01

70

In vivo magnetic resonance techniques and drug discovery  

International Nuclear Information System (INIS)

The long and resource intensive process of drug discovery and development is confronted with the basic challenge of providing effective and safe therapies at reasonably low costs. The better the mechanism of a disease is known, the higher the probability to find an appropriate therapy. Also, the better and earlier a disease can be diagnosed and characterized, the higher the chance to be able to interfere in this process with a chemical entity. This reasoning sets the framework for the use of imaging in drug discovery. We discuss the relevance of magnetic resonance imaging and spectroscopy to derive anatomical, functional, metabolic and target-related information in the context of pharmacological research in vivo. (author)

2006-03-01

71

Evidence at the 10/sup -18/ probability level against the production of magnetic monopoles in proton interactions at 300 GeV/c  

CERN Document Server

No magnetic monopoles were found in 2.5*10/sup 18/ primary proton- aluminium interactions produced by exposing an aluminium target to the Fermilab 300 GeV/c proton beam. Negative searches have also resulted from exposures of material to electrons at SLAC and from pp interactions at the CERN-ISR. The monopole pair production probability in proton-nucleon collisions is shown to be of order 10/sup -18/ or less, with 95% confidence level, if monopoles have masses less than 12 GeV. (24 refs).

1975-01-01

72

Effects of velocity-dependent force on the magnetic form factors of odd-Z  

International Nuclear Information System (INIS)

We investigate the effects of the velocity-dependent force on the magnetic form factors and magnetic moments of odd-Z nuclei. The form factors are calculated with the harmonic-oscillator wavefunctions. It is found that the contributions of the velocity-dependent force manifest themselves in the very large momentum transfer region (q?4 fm-1). In the low and medium q region the contributions of the velocity-dependent force are very small compared with those without this force. However, in the high-q region the contributions of the velocity-dependent force are larger than the normal form factors. The diffraction structures beyond the existing experimental data are found after the contributions of the velocity-dependent force are included. The formula of the correction to the single particle magnetic moment due to the velocity-dependent force is reproduced exactly in the long-wavelength limit (q=0) of the ...

2008-03-01

73

Introduction  

International Nuclear Information System (INIS)

In the Introduction the history of the cascade probabilistic method development is described. The calculation model for different charged particles cascade probabilistic functions (CPF) was considered. A new analytical expressions for CPF for electrons, protons, alpha-particles and ions are obtained as well. A new results on mathematical analysis, algorithms, and calculation of CPF with taking into account charged particles energy losses on computer are cited. The peculiarities of these functions are analyzed. The detail analysis of these function behavior in relation from flying particles energy, target atomic number, generation and registration depth, and interactions number is carried out. The program packages in the Windows medium is developed on the visual programming languages: Visual Basic 6.0, Delphi 6.0, C++ Builder 6.0.

74

Histological analysis of 70-nm silica particles-induced chronic toxicity in mice  

British Library Electronic Table of Contents (United Kingdom)

Nano-sized silica is a promising material for disease diagnosis, cosmetics and drugs. For the successful application of nano-sized material in bioscience, evaluation of nano-sized material toxicity is important. We previously found that nano-sized silica particles with a diameter of 70nm showed acute liver failure in mice. Here, we performed histological analysis of major organs such as the liver, spleen, lung, kidney, brain and heart in mice, chronically injected with 70-nm silica particles for 4weeks. Histological analysis revealed hepatic microgranulation and splenic megakaryocyte accumulation in these 70-nm silica particles treated mice, while the kidney, lung, brain and heart remained unaffected. Thus, liver and spleen appear to be the major target organs for toxicity by the chronic a...

2009-01-01

75

A Bragg curve counter with an internal production target for the measurement of the double-differential cross-section of fragment production induced by neutrons at energies of tens of MeV  

Energy Technology Data Exchange (ETDEWEB)

A Bragg curve counter equipped with an internal production target was developed for the measurements of double-differential cross-sections of fragment production induced by neutrons at energies of tens of MeV. The internal target permitted a large detection solid angle and thus the registration of processes at low production rates. In this specific geometry, the detection solid angle depends on the emission angle and the range of the particle. Therefore the energy, atomic number, and angle of trajectory of the particle have to be taken into account for the determination of the solid angle. For the selection of events with tracks confined within a defined cylindrical volume around the detector axis, a segmented anode was applied. The double-differential cross-sections for neutron-induced production of lithium, beryllium, and boron fragments from a carbon target were measured at 0 ...

2009-11-11

76

Size and morphology of heavy-duty vehicle particle emissions; Raskaan ajoneuvokannan hiukkaspaeaestoen koko ja morfologia - HD-PM  

Energy Technology Data Exchange (ETDEWEB)

Formation of particles from heavy duty diesel and CNG vehicles was studied in laboratory conditions. PM, nano and soot mode particle emissions formed from buses of Euro 2-5 -emission levels were studied in relation to age and type approval characteristics of the vehicle. Characteristic particle emission factors from city driving were obtained by driving the buses on VTT's heavy duty chassis dynamometer applying the transient Braunschweig city cycle. The vehicles were a representative set of Euro 2 to 3 emission categories, supplemented with Euro 4-5 (EEV) -targeted CRT, CNG and DPF cars. Particle number emissions from Euro 4 to 5 buses were 1/100-1/1000 and mass emissions 1/10-1/100 of those of the current fleet. Particle emission from natural gas buses and after an advanced CRT trap contained almost entirely liquid < 60 nm nano ...

2006-10-15

77

Proton G{sub E}/G{sub M} from beam-target asymmetry  

Science.gov (United States)

The ratio of the proton's electric to magnetic form factor, G{sub E}/G{sub M}, can be extracted in elastic electron-proton scattering by measuring cross sections, beam-target asymmetry, or recoil polarization. Separate determinations of G{sub E}/G{sub M} by cross sections and recoil polarization observables disagree for Q{sup 2}>1 (GeV/c){sup 2}. Measurement by a third technique might uncover an unknown systematic error in either of the previous measurements. The beam-target asymmetry has been measured for elastic electron-proton scattering at Q{sup 2} = 1.51 (GeV/c){sup 2} for target spin orientation aligned perpendicular to the beam momentum direction. This is the largest Q{sup 2} at which G{sub E}/G{sub M} has been determined by a beam-target asymmetry experiment. The result, {mu}G{sub E}/G{sub M}=0.884{+-}0.027{+-}0.029, is compared to previous world data.

2006-09-15

78

Low temperature partly ionized plasma in magnetic fusion devices: Present status and prospects  

Energy Technology Data Exchange (ETDEWEB)

The most striking achievement in magnetic fusion experiments during last few years was the discovery of plasma detachment from material targets, a much needed effect for plasmas with high power fusion parameters. Due to the very low heat loads on the targets observed in these regimes and potentially low erosion of the targets, detached regimes look attractive from the International Thermonuclear Experimental Reactor (ITER) design point of view. Thus the author has experimental proof for the possibility for a co-existence of fusion relevant hot plasma in the core and a low temperature partly ionized plasma at the edge of magnetic fusion device. Although somewhat similar behavior of edge plasma was considered theoretically even before plasma detachment was found experimentally, it was not clear in the beginning how these theoretical and experimental findings would fit together. Now, ...

1998-12-31

79

Real time neutron dosemeter response calculations  

International Nuclear Information System (INIS)

The response of a real time neutron dosemeter using a thin LiF target sandwiched between tow parallel surface barrier semiconductor detectors is studied for different neutron distributions and different angles of incidence. Calculations of the response function defined for a simultaneous detection by the two detectors of the particles emitted when the reaction "6Li(n,t)#alpha# occurs in the target are fulfilled by geometrical considerations of the reaction kinematics and the differential cross section variations. Finally, the efficiency of the studied detection systems is analyzed for dosimetric uses. (author).

1996-04-01

80

Controlling Charge and Current Neutralization of an Ion Beam Pulse in a Background Plasma by Application of a Solenoidal Magnetic Field I: Weak Magnetic Field Limit  

Energy Technology Data Exchange (ETDEWEB)

Propagation of an intense charged particle beam pulse through a background plasma is a common problem in astrophysics and plasma applications. The plasma can effectively neutralize the charge and current of the beam pulse, and thus provides a convenient medium for beam transport. The application of a small solenoidal magnetic field can drastically change the self-magnetic and self- electric fields of the beam pulse, thus allowing effective control of the beam transport through the background plasma. An analytic model is developed to describe the self-magnetic field of a finite- length ion beam pulse propagating in a cold background plasma in a solenoidal magnetic field. The analytic studies show that the solenoidal magnetic field starts to infuence the self-electric and self-magnetic fields when ?ce > ?pe?b, where ?ce = e?/mec is the ...

2008-10-10

81

Synthesis of colloidal silver iron oxide nanoparticles--study of their optical and magnetic behavior.  

Science.gov (United States)

Silver iron oxide nanoparticles of fairly small size (average diameter approximately 1 nm) with narrow size distribution have been synthesized by the interaction of colloidal beta- Fe2O3 and silver nanoparticles. The surface morphology and size of these particles have been analyzed by using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Their structural analysis has been carried out by employing x-ray diffraction (XRD), selected-area electron diffraction (SAED), optical and infrared (IR) spectroscopic techniques. The ageing of these particles exhibits the formation of self-assembly, possibly involving weak supramolecular interactions between Ag(I)O4 and Fe(III)O4 species. These particles display the onset of absorption in the near-infrared region and have higher absorption coefficient in the visible range compared to that of its precursors. ...

2009-07-01

82

Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV  

Energy Technology Data Exchange (ETDEWEB)

Results of an experimental study of the interaction of 140 MeV alpha particles with /sup 90/Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from /sup 90/Zr(..cap alpha..,pp)X reactions, where both of the measured protons have energy ...

1980-01-01

83

Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV  

International Nuclear Information System (INIS)

Results of an experimental study of the interaction of 140 MeV alpha particles with _9_0Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from _9_0Zr(#alpha#,pp)X reactions, where both of the measured protons have energy distributions ...

84

The metrology of the LHC project: what news?  

Energy Technology Data Exchange (ETDEWEB)

The Large Hadron Collider (LHC), under construction at CERN, uses superconducting magnets operating at a temperature of 1.9 K to guide the circulating particles. A specific feature of the main magnets (dipoles and quadrupoles) is the two-in-one design with two magnetic channels in one common retaining structure. Indeed, the accelerator is made of two rings, mechanically linked, that have to be simultaneously aligned during the installation in the already existing LEP tunnel. The assembly tolerances of the LHC main magnets have been reconsidered to take into account the tight constraints on geometry. The dipoles are bent to follow closely the curvature of the circulating particles and to make a larger mechanical aperture available for the circulating particles. In order to minimise the geometrical errors the dipole assembly procedure is ...

1999-07-01

85

Strong fields and recycled accelerator parts as a laboratory for fundamental physics  

International Nuclear Information System (INIS)

Over the last few years it has become increasingly clear that low energy, but high precision experiments provide a powerful and complementary window to physics beyond the Standard Model. In this note we illuminate this by using minicharged particles as an example. We argue that minicharged particles arise naturally in extensions of the Standard Model. Compatibility with charge quantization arguments suggests that minicharged particles typically arise together with a massless hidden sector U(1) gauge field. We present several low energy experiments employing strong lasers, electric and magnetic fields that can be used to search for (light) minicharged particles and their accompanying U(1) gauge boson.

2009-12-01

86

Possible control scenario of radial electric field by loss-cone-particle injection into helical device  

Energy Technology Data Exchange (ETDEWEB)

The possibility of controlling the radial electric field of toroidal plasmas by injecting high energy electrons along the reversible loss cone orbit of the helical magnetic traps is investigated. It is well known that the radial electric field plays an important role in the confinement improvement scenario especially in the low collisional regime under the physics picture of neoclassical theory. For this purpose, it is made clear that the most suitable particles are transit particles, which show a transition from helically trapped orbits to blocked ones. It is also found that a parallel AC electric field launched from outside assists this transition and makes it possible for particles to penetrate deeply into the plasma. In addition we clarify that the viscosity of the plasma coupled with the helical field configuration provide a bifurcation of plasma states and its stable solution results in ...

1999-08-01

87

A novel semidry flue gas desulfurization process with the magnetically fluidized bed reactor.  

Science.gov (United States)

The magnetically fluidized bed (MFB) was used as the reactor in a novel semidry flue gas desulfurization (FGD) process to achieve high desulfurization efficiency. Experiments in a laboratory-scale apparatus were conducted to reveal the effects of approach to adiabatic saturation temperature, Ca/S molar ratio and applied magnetic field intensity on SO(2) removal. Results showed that SO(2) removal efficiency can be obviously enhanced by decreasing approach to adiabatic saturation temperature, increasing Ca/S molar ratio, or increasing applied magnetic field intensity. At a magnetic field intensity of 300Oe and a Ca/S molar ratio of 1.0, the desulfurization efficiency (excluding desulfurization efficiency in the fabric filter) was over 80%, while spent sorbent appeared in the form of dry powder. With the SEM, XRD and EDX research, it can be found that the increase of DC magnetic field ...

2009-03-18

88

Inelastic excitation in the collisions of relativistic heavy ions  

International Nuclear Information System (INIS)

The penumbra of the profile function describing the nuclear collisions of relativistic heavy ions is related to the cross section for their producing a specific target-nucleus #gamma#-ray, sigmasub(#gamma#). The analysis assumes that the diffuse-edge diffraction model suffices to calculate the inelastic cross sections to the particle-stable states of the target nucleus. When the deformation lengths, deltasub(L) = #beta#sub(L)R, characterizing all important excitations are available from other experiments and the #gamma#-branching of these states is also known, the only unknown quantity determining sigmasub(#gamma#) is found to be the ratio of the diffuseness parameter of the profile function, d, to its radius, R. The most reliably determined values of d/R, for the target "4"0Ca, imply a rather wide penumbra, consistent with microscopic calculations. (orig.).

89

Spectroscopy of Neutron-Rich Nuclei with the CLARA-PRISMA Setup  

International Nuclear Information System (INIS)

The CLARA-PRISMA setup, composed of an array of 25 Clover detectors placed at the target position of the magnetic spectrometer PRISMA, has recently concluded its campaign to study the structure of moderately neutron-rich nuclei. In this contribution, results obtained in the vicinity of the doubly-magic nucleus "4"8Ca are presented, together with results obtained for the heavy iron isotopes. The perspectives offered by the forthcoming operation of the AGATA Demonstrator Array coupled to PRISMA are also discussed. (author)

2009-03-01

90

Alpha-particle emission from carbon bombarded with neutrons below 30 MeV  

Energy Technology Data Exchange (ETDEWEB)

Alpha-particle emission induced by neutron bombardment of carbon has been studied from threshold to over 30 MeV using the spallation neutron source at WNR/LAMPF. Targets include thin foils of CH{sub 2} and thicker foils of CH and polycrystalline graphite. Comparisons are made with evaluated data. Values for KERMA (kinetic energy released in materials) based on the results will be presented and compared with those obtained through other experimental approaches.

1994-07-01

91

Neutrino emission in neutron matter from magnetic moment interactions  

CERN Document Server

Neutrino emission drives neutron star cooling for the first several hundreds of years after its birth. Given the low energy ($\\sim$ keV) nature of this process, one expects very few nonstandard particle physics contributions which could affect this rate. Requiring that any new physics contributions involve light degrees of freedom, one of the likely candidates which can affect the cooling process would be a nonzero magnetic moment for the neutrino. To illustrate, we compute the emission rate for neutrino pair bremsstrahlung in neutron-neutron scattering through photon-neutrino magnetic moment coupling. We also present analogous differential rates for neutrino scattering off nucleons and electrons that determine neutrino opacities in supernovae. Employing current upper bounds from collider experiments on the tau magnetic moment, we find that the neutrino emission rate can exceed the rate through neutral ...

2004-01-01

92

Saturation of relativistic Weibel instability and the formation of stationary current sheets in collisionless plasma  

International Nuclear Information System (INIS)

We have studied the features of formation and the possible stationary structures of a self-consistent magnetic field in a relativistic collisionless plasma, which are characteristic of a simple geometry of the Weibel instability that is well known in the nonrelativistic case. The universal condition is established, the growth rate is determined, and the criteria of saturation of the Weibel instability are analyzed for a broad class of anisotropic particle distribution functions (for definiteness, in application to an electron-positron plasma). A nonlinear equation of the Grad-Shafranov type describing the potential current structures is derived and its solutions are analytically studied. Special attention is paid to spatially harmonic, nonlinear current configurations with parameters determined by the properties of the initial homogeneous plasma subject to the Weibel instability. It is demonstrated that the magnetic field ...

2008-12-01

93

Systemic combinatorial peptide selection yields a non-canonical iron-mimicry mechanism for targeting tumors in a mouse model of human glioblastoma  

UK PubMed Central (United Kingdom)

The management of CNS tumors is limited by the blood-brain barrier (BBB), a vascular interface that restricts the passage of most molecules from the blood into the brain. Here we show that phage particles...Full Text Available

2011-01-04

94

Evidence for long-lived isomeric states in neutron-deficient /sup 236/Am and /sup 236/Bk nuclei  

Energy Technology Data Exchange (ETDEWEB)

A 5.76 MeV alpha-particle group has been observed in Am and Bk sources separated from a CERN W target. The data are interpreted due to the production of long-lived isomeric states in /sup 236/Am and /sup 236/Bk which decay to /sup 236/Pu. The possibility of high spin states as well as of shape isomeric states is raised.

1987-06-04

95

Amino-Terminal Region of the Human Immunodeficiency Virus Type 1 Nucleocapsid Is Required for Human APOBEC3G Packaging  

UK PubMed Central (United Kingdom)

APOBEC3G exerts its antiviral activity by targeting to retroviral particles and inducing viral DNA hypermutations in the absence of Vif. However, the mechanism by which APOBEC3G is packaged into virions...Full Text Available

2004-11-01

96

On the validity of the pseudo-spin concept for axially symmetric deformed nuclei  

International Nuclear Information System (INIS)

The average single-particle field shows a very small pseudo-spin-orbit splitting in the pseudo-spin representation. If this splitting is neglected, pseudo-spin becomes a good quantum number and the resulting scheme (the pseudo-Nilsson model) has a very simple interpretation. The pseudo-spin symmetry embodied in the realistic deformed average field is explored by comparing the single-particle energies and wave functions of the deformed Woods-Saxon model with the corresponding results of the pseudo-Nilsson model. The scheme is used to calculate the magnetic moments of deformed odd-A nuclei of the rare-earth region. (orig.).

97

High energy beams of radioactive nuclei and their biomedical applications  

Energy Technology Data Exchange (ETDEWEB)

It is possible to produce energetic beams of radioactive nuclei, as secondary beams, from the heavy-particle compound accelerator called BEVALAC. These beams can be focused into experimental areas without significant contamination using suitable magnetic filters and proper beam-optics. Properly selected high-energy beams of radioactive nuclei (those which defay by positron emission) can provide a truly unique opportunity to evaluate the effectiveness of these beams in localizing the Bragg peak on a tumor volume - necessary in heavy-particle therapy. Preliminary data are presented here to demonstrate the possible use of these beams in radiotherapy treatment-planning verification.

1981-04-01

98

Encapsulated magnetite particles for biomedical application  

International Nuclear Information System (INIS)

The process of miniemulsification allows the generation of small, homogeneous, and stable droplets containing monomer or polymer precursors and magnetite which are then transferred by polymer reactions to the final polymer latexes, keeping their particular identity without serious exchange kinetics involved. It is shown that the miniemulsion process can excellently be used for the formulation of polymer-coated magnetic nanoparticles which can further be used for biomedical applications. The use of high shear, appropriate surfactants, and the addition of a hydrophobe in order to suppress the influence of Ostwald ripening are key factors for the formation of the small and stable droplets in miniemulsion and will be discussed. Two different approaches based on miniemulsion processes for the encapsulation of magnetite into polymer particles will be presented in detail.

2003-04-23

99

Ternary and quaternary fission  

Energy Technology Data Exchange (ETDEWEB)

In a systematic survey of ternary fission induced by thermal neutrons at the Lohengrin spectrometer of the ILL/Grenoble, the target nucleus {sup 249}Cf has recently been added to the list of actinides under study. Special emphasis was put on the search for the heaviest ternary particles. At the limit of detection (some 10{sup -9} per fission), the heaviest isotopes observed for {sup 249}Cf(n{sub th},f) are {sup 37}Si and {sup 37}S. Another rare process in low energy fission is quaternary fission. Here two light charged particles accompany the main fragments. The reaction {sup 233} U(n,f) has been studied at a cold neutron beam of the ILL. Two processess have to be disentangled: simultaneous and sequential quaternary fission. In the simultaneous decay the most probable combination of particles is ({alpha} + {alpha}) with a yield of {approx}10{sup -7}/fission.

2004-04-05

100

Measurement of dose distributions of linear energy transfer in matter irradiated by fast neutrons  

Energy Technology Data Exchange (ETDEWEB)

A detector has been developed and used to measure dose distributions versus linear energy transfer to thin gas targets in spherical geometry from fast neutron irradiation of tissue-equivalent plastic and carbon. The detector is a hemispherical proportional counter with a Cs(T1) scintillator at the center of the hemisphere. The coincidence of the proportional counter signals constrain the measurements to charged particles traversing the radius of the hemisphere. The charged particle energy deposition distributions are directly measured for a known pathlength. The A-150 kerma factor was measured at a neutron energy of 14.8 MeV and is in agreement with tabulated values. The carbon kerma factor measurements are less than the tabulated value at 14.8 MeV. The alpha-particle production in carbon was measured for neutron energies from 14.1 to 14.8 MeV and is compared with existing data.

1990-01-01

101

Highly-sensitive ion selective electrode based on molecularly imprinted polymer particles for determination of tetracycline in aqueous samples  

British Library Electronic Table of Contents (United Kingdom)

In this work, a highly-sensitive polymeric membrane ion selective electrode for determination of tetracycline was constructed by using molecularly imprinted polymer (MIP) particles as quasi-ionophore. The water-compatible MIP particles targeting tetracycline were synthesized with tetracycline as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, 2,2?-azobisisobutyronitrile as an initiator and lanthanum ion as a mediator. Benefited from the distinctive performance of the quasi-ionophore and the optimized composition of the membrane and the inner filling solution, the lower detection limit of the electrode was decreased to about 1 ? 10?8 mol/l. It exhibited a good electrode slope 59.8 mV/decade near the theoretical Nernstian one, ...

2011-01-01

102

A study of the projectile break-up mechanism at intermediate energies by means of the multidetector ARGOS  

Energy Technology Data Exchange (ETDEWEB)

The reaction mechanism underlying the 44 MeV/u {sup 40}Ar projectile break-up process has been studied on different targets, by measuring the coincidences between light particles or intermediate mass fragments detected in a large angular range, and projectile fragments or light charged particles. While the experimental data relative to projectile-like fragments (PLF) with charge close to the one of the projectile can be interpreted in the framework of a three source analysis, the anomalous light fragment production with Z {<=} 10 rather suggests `fission` as one of the possible decay mode of the highly excited projectile or PLF. It is also observed that a great amount of the forward detected light charged particles are correlated, and due to the break-up or decay of light excited ions. (author). 9 refs.

1996-09-01

103

Electron-beam sensitivity study of the Los Alamos Advanced Free-Electron Laser beam line  

Energy Technology Data Exchange (ETDEWEB)

A sensitivity study that used the particle tracking code PARMELA was performed on the Advanced Free-Electron Laser (AFEL). The tolerances on the alignment of the beam-line elements and the magnetic-field strengths were examined. Two base-line configurations were determined at the beginning of the study. The electron beam was then matched into the wiggler. The optimized beam-line parameters were varied independently and their sensitivities were judged with the criterion that the free-electron laser (FEL) effective-detuning parameter should not fluctuate more than 10%. The results of this study set the specifications for the alignment, for the sensitivity of the steering magnets, and for the accuracy of the magnetic field in the quadrupoles and dipoles. 5 figs., 3 figs., 3 tabs.

1991-01-01

104

Size and morphology of fine particle emissions from heavy-duty vehicles; Raskaan ajoneuvokannan hiukkaspaeaestoen koko ja morfologia - HD-PM  

Energy Technology Data Exchange (ETDEWEB)

Exhaust fine and ultra fine particle numbers, particle sizes, mass, shape, structure and density were studied from Euro II - EEV emission level heavy-duty vehicles. For total particle emission factors city buses were run on dynamic conditions simulating city bus driving. The new heavy-duty chassis dynamometer of VTT was used. Vehicles were a comprehensive sample of current city bus fleet, the type approved emission level of which was Euro II - Euro III. Also cleaner engines of Euro IV to EEV targeted emission level were included: CRT, CNG, DPF. Particle emissions of these buses were extremely low; numbers 1/100 - 1/1000 and masses 1/10 - 1/100 of those of the predominating techniques. Morphological properties of fine particle populations that represent majority of particle size distribution (Da < 500 nm) are being analyzed by image ...

2004-07-01

105

Charged particle spectra: 140 MeV #alpha# particle bombardment of "2"7Al, "5"8Ni, "9"0Zr, "2"0"9Bi, and "2"3"2Th  

International Nuclear Information System (INIS)

Complete energy spectra and angular distributions of the light charged particles (A < or = 4) were measured for the bombardment of "2"7Al, "5"8Ni, "9"0Zr, "2"0"9Bi, and "2"3"2Th with 140 MeV #alpha# particles. The spectral shapes of a given emitted particle are very similar for all target nuclei except in the region of the evaporation peak. The slopes of the energy spectra in the forward direction become steeper as the mass of the observed particle decreases and vary very rapidly with angles. The experimental data can be characterized by compound nuclear evaporation processes at low energies, or at backward angles, and by direct reactions, nonequilibrium components and projectile breakup processes at high energies and forward angles. The breakup cross section for #alpha# particles is found to be appreciable. The total yield of light charged ...

106

Intranuclear Cascade and Exciton Model calculation of 100-MeV #alpha#-particle-induced reactions on light nuclei  

International Nuclear Information System (INIS)

Theoretical interpretation of fast-charged-particle spectra, observed in the #alpha#-particle-induced reactions on the s-d shell nuclei (A = 24-28), in terms of the Intranuclear Cascade Model and the GDH exciton model (ALICE) is presented. The de-excitation of the excited residual nuclei is accounted for by the evaporation process. The theoretically predicted fast-proton and #alpha#' spectral shapes compare reasonably well with the corresponding measured spectra. However, the magnitude depends critically (as expected) on the reaction cross section employed by the model. As a first step to improve the model predictability of the reaction products, a closer look at the calculation of the #alpha#-particle reaction cross sections was undertaken. A microscopic approach using the optical theorem of Glauber's theory was employed to estimate the #alpha#-induced reaction cross sections for the light target ...

107

Contribution to the study of sputtering and damage of uranium dioxide by fast heavy ions; Contribution a l'etude de la pulverisation et de l'endommagement du dioxyde d'uranium par les ions lourds rapides  

Energy Technology Data Exchange (ETDEWEB)

Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the ...

2001-03-01

108

Sequential separation of carrier free {sup 52,56}Mn, {sup 55,56,58}Co and {sup 56,57}Ni from {alpha}-particle activated iron with triisooctylamine  

Energy Technology Data Exchange (ETDEWEB)

A radiochemical charged particle activation procedure for production and separation of carrier free {sup 52,56}Mn, {sup 55,56,58}Co and {sup 56,57}Ni has been developed. The radioisotopes produced on bombardment of an iron foil target with a 40 MeV {alpha}-particle beam through the nuclear reactions, Fe({alpha}, {alpha}pxn){sup 52,56}Mn, Fe({alpha}, pxn){sup 55,56,58}Co and Fe({alpha}, nx){sup 56,57}Ni, have been separated by LLX. The target element and the activation products have been sequentially separated from an HCl medium using diethylether and the liquid anion exchanger, TIOA, as extractants. Extent of separation and purity of the carrier free radiotracers at different stages of their LLX separation have been verified by taking recourse to {gamma}-ray spectrometry. (Author).

1996-04-01

109

Quantitative assessment of cancer risk from exposure to diesel engine emissions  

Energy Technology Data Exchange (ETDEWEB)

Quantitative estimates of lung cancer risk from exposure to diesel engine emissions were developed using data from three chronic bioassays with Fischer 344 rats. Human target organ dose was estimated with the aid of a comprehensive dosimetry model. This model accounted for rat-human differences in deposition efficiency, normal particle clearance rates, transport of particles to lung-associated lymph nodes, respiration rates, and lung surface area, as well as high-dose inhibition of particle clearance. Recent evidence indicates that the inert carbon core of the diesel particulate matter is likely to be the primary source of carcinogenicity. The epithelial tissue lining the alveoli and lower airways is the primary target site for induction of lung tumors. Dose was therefore based upon the concentration of carbon particulate matter per unit lung surface area. Unit risk estimates were ...

1993-02-01

110

Measurements of K-shell x-ray production cross sections and K to L and M-shell radiative vacancy transfer probabilities for Nd, Eu, Gd, Dy and Ho at excitation with 59.5 keV photons in an external magnetic field  

International Nuclear Information System (INIS)

The effect of the #+-# 0.75 T external magnetic field on the K_#alpha#_1, K_#alpha#_2, K_#beta#_'_1 and K_#beta#_'_2 x-ray production cross sections and radiative vacancy transfer probabilities from K-shell to L2 and L3 subshells and M-shell for ferromagnetic Nd, Gd and Dy and paramagnetic Eu and Ho have been investigated, using the 59.5 keV incident photons. K-shell fluorescence yields and K x-ray intensity ratios for these elements have been determined in the external magnetic field also. The K x-rays from different targets were detected using a high-resolution Si(Li) semiconductor detector. For B = 0, the present experimental results were compared with the experimental and theoretical data in the literature. The results show that K-shell fluorescence parameters such as photoionization cross section, fluorescence yield, radiation rates, vacancy transfer probabilities and spectral linewidth can change owing to the applied ...

2006-06-19

111

Materials considerations for the National Spallation Neutron Source target  

Energy Technology Data Exchange (ETDEWEB)

The National Spallation Neutron Source (NSNS), in which neutrons are generated by bombarding a liquid mercury target with 1 GeV protons, will place extraordinary demands on materials performance. The target structural material will operate in an aggressive environment, subject to intense fluxes of high energy protons, neutrons, and other particles, while exposed to liquid mercury and to water. Components that require special consideration include the Hg liquid target container and protective shroud, beam windows, support structures, moderator containers, and beam tubes. In response to these demands a materials R and D program has been developed for the NSNS that includes: selection of materials; calculations of radiation damage; irradiations, post irradiation testing, and characterization; compatibility testing and characterization; design and implementation of a plan for monitoring of materials ...

1997-08-01

112

{delta}f simulation of ion neoclassical transport  

Energy Technology Data Exchange (ETDEWEB)

Ion neoclassical transport with finite orbit width dynamics is calculated over whole poloidal cross section by using accurate {delta}f method which employs an improved like-particle collision operator and an accurate weighting scheme to solve drift kinetic equation. Ion thermal transport near magnetic axis shows a great reduction from its conventional neoclassical level due to non-standard orbit topology, like that of previous {delta}f simulation. On other hand, the direct particle loss from confinement region may strongly increase ion energy transport near the edge. It is found that ion parallel flow near the axis is also largely reduced due to non-standard orbit topology. In the presence of steep density gradient, ion thermal conductivity is significantly reduced, and an ion particle flux is driven by self-collision alone. (author)

1999-07-01

113

Transuranic separation using organophophorus extractants adsorbed onto superparamagnetic carriers.  

Energy Technology Data Exchange (ETDEWEB)

Polymeric coated ferromagnetic carriers with an absorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted by tributyl phosphate (TBP) are being evaluated for application in the separation and the recovery of low concentrations of americium, plutonium, and uranium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles and the complexed particles can be recovered from the solution using a magnet. Physical and chemical characterization of the extractant-absorbed particles were performed by gamma and liquid scintillation counting, scanning electron microscopic (SEM) micrograph, and other physical measurements. Plutonium, americium, and uranium separations have been performed at various HNO{sub 3} and HCl concentrations. Parameters were studied to determine the limitations and ...

1998-10-07

114

Three-dimensional particle simulation of plasma instabilities and collisionless reconnection in a current sheet  

Energy Technology Data Exchange (ETDEWEB)

Generation of anomalous resistivity and dynamical development of collisionless reconnection in the vicinity of a magnetically neutral sheet are investigated by means of a three-dimensional particle simulation. For no external driving source, two different types of plasma instabilities are excited in the current layer. The lower hybrid drift instability (LHDI) is observed to grow in the periphery of current layer in an early period, while a drift kink instability (DKI) is triggered at the neutral sheet in a late period as a result of the nonlinear deformation of the current sheet by the LHDI. A reconnection electric field grows at the neutral sheet in accordance with the excitation of the DKI. When an external driving field exists, the convective electric field penetrates into the current layer through the particle kinetic effect and collisionless reconnection is triggered by the convective electric field earlier than the ...

1999-06-01

115

Multi-GeV electron spectrometer  

Energy Technology Data Exchange (ETDEWEB)

The advance in laser-plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular the upcoming experiments with the FLAME laser at LNF will enter the GeV regime with almost 1nC of electrons. From the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need to develop a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV) under still unknown angular divergences. Within the PlasmonX experiment at LNF a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence ...

2010-11-11

116

Behavior of particle-filled polymer composite under static and dynamic loading  

British Library Electronic Table of Contents (United Kingdom)

Experimental results of quasi-static and dynamic fracture of particle-filled polymer composite (PFPCM) "ALTUGLAS EI CH25" with a matrix of polymethylmethacrylate (PMMA) are reported in this paper. PMMA matrix is filled with rubber particles, as result a shock-resistant transparent composite is produced. The main task was to investigate experimentally and theoretically the fracture toughness of this composite under static and dynamic loading. A high-rate loading has been created by impulse magnetic field. Analysis of fracture process and its relation with the load parameters and material microstructure have been established. Application of the original testing method enabled determination of fracture toughness at very short loading times and comparison of the results with material dynamic p...

2008-01-01

117

Particle Swarm Optimization  

CERN Document Server

Particle Swarm Optimization

2006-01-01

118

A concept for the experimental determination of the nucleon electric to magnetic form factor ratio at very low Q{sup 2}  

Energy Technology Data Exchange (ETDEWEB)

Stationary target measurements of the nucleon form factors have been performed with high precision down to Q{sup 2} of {approx} 0.01 GeV{sup 2} for protons (G{sub E}{sup p}) and down to {approx} 0.1 GeV{sup 2} for neutrons (G{sub M}{sup n}). Conventional extraction using cross section and polarization measurement cannot be extended to very low values of Q{sup 2} due to inherent experimental limitations. We present a proposal for a new approach to a measurement, using colliding beams, which will extend the range of possible measurement at low Q{sup 2} by several orders of magnitude over stationary target limits.

2009-05-15

119

A concept for the experimental determination of the nucleon electric to magnetic form factor ratio at very low Q2  

International Nuclear Information System (INIS)

Stationary target measurements of the nucleon form factors have been performed with high precision down to Q2 of ? 0.01 GeV2 for protons (GEp) and down to ? 0.1 GeV2 for neutrons (GMn). Conventional extraction using cross section and polarization measurement cannot be extended to very low values of Q2 due to inherent experimental limitations. We present a proposal for a new approach to a measurement, using colliding beams, which will extend the range of possible measurement at low Q2 by several orders of magnitude over stationary target limits.

2009-05-01

120

P and e identification capabilities CAPRICE  

Energy Technology Data Exchange (ETDEWEB)

The cosmic antiparticle ring imaging Cherenkov experiment (CAPRICE) flew on a stratospheric balloon 8-9 August 1994 over northern Canada and collected data for more than 21 hours with less than 5 g/cm{sup 2} of residual atmosphere. The instrument includes a solid radiator RICH detector and an electromagnetic calorimeter for particle identification in the magnetic spectrometer. Preliminary antiproton and positron identification capabilities are presented.

1995-09-01

121

Interaction region layout of the VLEPP based photon linear collider with ultimate luminosity  

Energy Technology Data Exchange (ETDEWEB)

In the present paper, a possible interaction region layout of the VLEPP based Photon Linear Collider (PLC) with ultimate luminosity is discussed. In order to remove spent electron beams, the crab-crossing scheme is used. The detector is protected from produced pairs and secondary particles by means of the detector magnetic field and a shielding mask. ((orig.)).

1995-02-01

122

Formation of iron oxides during mechanical activation in water  

International Nuclear Information System (INIS)

It has been shown that mechanical milling of iron in water results in formation of nanocrystalline magnetite Fe3O4 with an average particle size of 0.6 ?m, saturation magnetization of 77 Am2/kg and coercivity of ?150 A/cm. Along with magnetite, an antiferromagnetic Fe-O phase (?10 wt%), which is an aggregate of small iron-oxygen clusters forms.

2007-05-21

123

Dimensional metrology and positioning operations: basics for a spatial layout analysis of measurement systems  

CERN Document Server

Dimensional metrology and positioning operations are used in many fields of particle accelerator projects. This lecture gives the basic tools to designers in the field of measure by analysing the spatial layout of measurement systems since it is central to dimensional metrology as well as positioning operations. In a second part, a case study dedicated to a synchrotron storage ring is proposed from the detection of the magnetic centre of quadrupoles to the orbit definition of the ring.

2010-01-01

124

A magneto-electric quantum wheel  

CERN Document Server

Here we show that self-propulsion in quantum vacuum may be achieved by rotating or aggregating magneto-electric nano-particles. The back-action follows from changes in momentum of electro-magnetic zero-point fluctuations, generated in magneto-electric materials. This effect may provide new tools for investigation of the quantum nature of our world. It might also serve in the future as a "quantum wheel" to correct satellite orientation in space.

2009-01-01

125

Roles of bumpy field on collisionless particle confinement in helical-axis heliotrons  

Energy Technology Data Exchange (ETDEWEB)

Roles of bumpy field on collisionless particle confinement in helical-axis heliotrons are investigated with the model magnetic field and particle orbit calculations in the Boozer coordinates. The mod-B{sub min} contours can be shifted in the major radius direction with the control of the bumpy field, where B{sub min} is the minimum value of |B| in the toroidal direction within one field period. The area of closed mod-B{sub min} contours is a useful measure to evaluate global collisionless particle confinement as long as the mod-B{sub min} contours connect toroidally. Negative value of ratio between the bumpy and the helicity components contributes to obtain the largest area of closed mod-B{sub min} contours for finite ratio between the toroidicity and the helicity components. The radial variation of the bumpy field attributes to realize a toroidally localized mod-B{sub min} structure, which is ...

1999-02-01

126

Direct energy conversion for IEC fusion for space applications  

Energy Technology Data Exchange (ETDEWEB)

The paper describes a concept of extracting fusion power from D-{sup 3}He fueled IEC (Inertia Electrostatic Configuration) devices. The fusion system consists of a series of fusion modules and direct energy converters at an end or at both ends. This system of multiple units is linear and is connected by a magnetic field. A pair of coils anti-parallel to the magnetic field yields a field-null domain at the center of each unit as required for IEC operation. A stabilizing coil installed between the coil pairs eliminates the strong attractive force between the anti-parallel coils. Accessible regions for charged particle trajectories are essentially isolated from the coil structure. Thus, charged particles are directed along magnetic field lines to the direct energy converter without appreciable losses. A direct energy converter unit designed to be compatible to this unique system is ...

2000-08-01

127

Gyrokinetic particle simulation model  

Energy Technology Data Exchange (ETDEWEB)

A new type of particle simulation model based on the gyrophase-averaged Vlasov and Poisson equations is presented. The reduced system, in which particle gyrations are removed from the equations of motion while the finite Larmor radius effects are still preserved, is most suitable for studying low frequency microinstabilities in magnetized plasmas. It is feasible to simulate an elongated system (L/sub parallel/ >> L/sub perpendicular/) with a three-dimensional grid using the present model without resorting to the usual mode expansion technique, since there is essentially no restriction on the size of ..delta..x/sub parallel/ in a gyrokinetic plasma. The new approach also enables us to further separate the time and spatial scales of the simulation from those associated with global transport through the use of multiple spatial scale expansion. Thus, the model can be a very efficient tool for studying anomalous transport ...

1986-07-01

128

Assembly of Linear Nano-Chains from Iron Oxide Nanospheres with Asymmetric Surface Chemistry  

Science.gov (United States)

Besides the multifunctionality, another equally important aspect of nanoparticles is their engineerability to control the geometrical and chemical properties during fabrication. In this work, we exploited this aspect to define asymmetric surface chemistry of an iron oxide nanosphere by controlling the topology of ligand expression on its surface resulting in a particle with two faces, one displaying only amines and the other only thiols. Specifically, amine-functionalized iron oxide nanospheres were attached on a solid support via a crosslinker containing a disulfide bridge. Liberation of the nanosphere using thiolytic cleavage created thiols on the portion of the particle's surface that interacted with the solid support. Employing a solid-phase strategy and a step-by-step addition of particles, the two unique faces on the same nanosphere served as fittings to assemble them into linear nano-chains. Assembly of chains with ...

2011-01-06

129

Particle emission from low energy nuclear reactions in solids. Preliminary results  

Energy Technology Data Exchange (ETDEWEB)

TiH{sub 2} and TiD{sub 2} thick targets were bombarded with 100 to 200 keV protons or deuterons. Evidence for nuclear reactions was obtained by means of a surface barrier particle detector. Deuteron irradiation of TiD{sub 2} produced these observations: copious {approx}2.5 MeV neutrons and {approx}3 MeV protons from direct D-D reactions; gamma rays from p,{gamma} and n,{gamma} reactions; {approx}14 MeV protons from the secondary d({sup 3}He, p){alpha} reaction; and a signal between {approx}6-12 MeV that Kasagi et al. has tentatively identified as protons from the fusion of three deuterium nuclei. However, this signal has in it a strong interference signal from either neutrons or gamma rays that directly deposit energy in the detector. This interference spectra was measured by placing a thick absorber in front of the detector that stops up to 20 MeV protons, but not gamma rays or neutrons. More experiments must be done before we can confirm or ...

2000-07-01

131

Twenty Years of Tevatron Operation  

Energy Technology Data Exchange (ETDEWEB)

The superconducting Tevatron accelerator at Fermi National Accelerator Laboratory (Fermilab) has surpassed twenty years of operation. The Tevatron is still the highest energy particle accelerator in the world and will remain so until the commissioning of the LHC in Europe later this decade. The Tevatron has operated in a Fixed Target mode, accelerating a proton beam into stationary targets/detectors, as well as a Colliding Beam mode, continuously colliding counter rotating beams of protons and antiprotons. Upon completion, the Tevatron cryogenic system became the world's largest helium refrigeration system. In 1993, the Tevatron cryogenic system was given the designation of International Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers. The operational history, experiences and statistics of the Tevatron, with an emphasis on the cryogenic system, is presented. Improvements, ...

2004-07-15

132

Photodynamic efficacy of hypericin targeted by two delivery techniques to hepatocellular carcinoma cells  

British Library Electronic Table of Contents (United Kingdom)

The photocytotoxic effect of hypericin (Hyp) targeted by two different delivery techniques, namely, liposomes and anti-hepatocyte specific antigen (anti-HSA) was investigated. Optical absorption and steady-state fluorescence were used to analyze the conjugation of Hyp with anti-HSA model and to evaluate the encapsulation capacity and drug release in a liposome model. Particle size and thermal analysis of the prepared liposomes were performed using laser-light scattering and differential scanning calorimetry (DSC), respectively. Viability study of HepG2 cells exposed to Hyp in the two delivery systems, in the dark and following visible light irradiation, was performed in comparison to free Hyp. The intracellular uptake and localization of Hyp in HepG2 cells were analyzed by means of spectro...

2010-01-01

133

Parameter study of the LIFE engine nuclear design  

British Library Electronic Table of Contents (United Kingdom)

LLNL is developing the nuclear fusion based Laser Inertial Fusion Energy (LIFE) power plant concept. The baseline design uses a depleted uranium (DU) fission fuel blanket with a flowing molten salt coolant (flibe) that also breeds the tritium needed to sustain the fusion energy source. Indirect drive targets, similar to those that will be demonstrated on the National Ignition Facility (NIF), are ignited at 13Hz providing a 500MW fusion source. The DU is in the form of a uranium oxycarbide kernel in modified TRISO-like fuel particles distributed in a carbon matrix forming 2-cm-diameter pebbles. The thermal power is held at 2000MW by continuously varying the 6Li enrichment in the coolants. There are many options to be considered in the engine design including target yield, U-to-C ratio in th...

2010-01-01

134

Cyclotron produced lead-203  

International Nuclear Information System (INIS)

The radioactive isotopes of lead are reviewed with respect to their choice for in vitro tracer studies. The #gamma#-photon energy and absence of particle emission in the decay of "2"0"3Pb makes it particularly suitable for these applications. Reaction yields of "2"0"3Pb using "2"0"3Tl targets and proton, deuteron, "3He and "4He beams are listed. Using the preferred reaction "2"0"3Tl (d, 2n)"2"0"3Pb with a 15 MeV deuteron beam, yields of about 75 #mu#Ci #mu#Ahr"-"1, after chemical separation, are reported. Details of target design and chemical separation are given. (U.K.).

135

Target identification of buried coated objects  

Scientific Electronic Library Online (English)

Abstract in english We consider the three dimensional electromagnetic inverse scattering problem of determining information about a buried coated object from a knowledge of the electric and magnetic fields measured on the surface of the earth corresponding to time harmonic electric dipoles as incident fields. We assume that the buried object is a perfect conductor that is (possibly) partially coated by a thin dielectric layer. No a priori assumption is made on the extent of the coating, i.e. (more) the object can be fully coated, partially coated or not coated at all. We present an algorithm based on the linear sampling method and reciprocity gap functional for reconstructing the shape of the scattering obstacle together with an estimate of the surface impedance of the coating.

2006-01-01

136

Spectroscopy of neutron-rich Fe isotopes populated in the "6"4Ni+"2"3"8U reaction  

International Nuclear Information System (INIS)

The neutron-rich Fe isotopes from A=61 to 66 were studied through multinucleon transfer reactions by bombarding a "2"3"8U target with a 400 MeV "6"4Ni beam. Unambiguous identification of prompt #gamma# rays belonging to each nucleus was achieved using coincidence relationships with the ions detected in a high-acceptance magnetic spectrometer. The new data extend our knowledge of the level structure of Fe isotopes, which is discussed in terms of the systematics of the region and compared with large-scale shell-model calculations.

2007-09-01

137

Physics with Polarized Antiprotons  

Energy Technology Data Exchange (ETDEWEB)

Polarized antiprotons produced by spin filtering with an internal polarized gas target provide access to a wealth of single- and double-spin observables, thereby opening a window to physics uniquely accessible with the HESR at FAIR. This includes a first measurement of the transversity distribution of the valence quarks in the proton, and a first measurement of the moduli and the relative phase of the time-like electric and magnetic form factors G{sub E,M} of the proton. In polarized and unpolarized pp-bar elastic scattering open questions like the contribution from the odd charge-symmetry Landshoff-mechanism at large |t| and spin-effects in the extraction of the forward scattering amplitude at low |t| can be addressed.

2006-04-15

138

Electron collisional detachment processes for a 250 keV D/sup -/ ion beam in a partially ionized hydrogen target  

Energy Technology Data Exchange (ETDEWEB)

Neutral atom beams with energies above 200 keV may be required for various purposes in magnetic fusion devices following TFTR, JET and MFTF-B. These beams can be produced much more efficiently by electron detachment from negative ion beams than by electron capture by positive ions. We have investigated the efficiency with which such neutral atoms can be produced by electron detachment in partially ionized hydrogen plasma neutralizers.

1980-09-01

139

Automatic beam position control at Los Alamos Spallation Radiation Effects Facility (LASREF)  

Energy Technology Data Exchange (ETDEWEB)

Historically the Los Alamos Spallation Radiation Effects Facility (LASREF) has used manual methods to control the position of the 800 kW, 800 MeV proton beam on targets. New experiments, however, require more stringent position control more frequently than can be done manually for long periods of time. Data from an existing harp is used to automatically adjust steering magnets to maintain beam position to required tolerances.

1997-08-01

140

Non-equilibrium reaction mechanism in alpha-particle induced excitation function for sup 209 Bi up to 60 MeV  

Energy Technology Data Exchange (ETDEWEB)

Excitation functions ({alpha},3n) and ({alpha},4n) for {sup 209}Bi have been measured up to 60 MeV {alpha}-particle energy. The excitation functions are measured at 15{alpha}-particle energies by a stack foil technique in two steps. Excitation functions for the above two reactions have been reported for the first time in the energy range from 40 to 60 MeV. The measured experimental values are compared with the geometry-dependent hybrid (GDH) model in which the emission of particles prior to the equilibrium decay is taken into account whenever the interaction of projectile with the target nucleus is considered. It is found that the compound nucleus decay mechanism alone is unable to explain the experimental trend of our data. The initial exciton number 4 with different configurations has been tested and it is concluded that the configuration (2n + 2p + 0h) gives the best fit to the experimental data. ...

1990-01-01

141

Non-equilibrium reaction mechanism in alpha-particle induced excitation function for "2"0"9Bi up to 60 MeV  

International Nuclear Information System (INIS)

Excitation functions (#alpha#,3n) and (#alpha#,4n) for "2"0"9Bi have been measured up to 60 MeV #alpha#-particle energy. The excitation functions are measured at 15#alpha#-particle energies by a stack foil technique in two steps. Excitation functions for the above two reactions have been reported for the first time in the energy range from 40 to 60 MeV. The measured experimental values are compared with the geometry-dependent hybrid (GDH) model in which the emission of particles prior to the equilibrium decay is taken into account whenever the interaction of projectile with the target nucleus is considered. It is found that the compound nucleus decay mechanism alone is unable to explain the experimental trend of our data. The initial exciton number 4 with different configurations has been tested and it is concluded that the configuration (2n + 2p + 0h) gives the best fit to the experimental data. ...

142

Cluster-flucton revelation in nuclear interactions at 4.2 (GeV/c)/N  

International Nuclear Information System (INIS)

Total longitudinal momentum of all registered particles, their total energy and other summary kinematics variables are used for separation of the events with two- and three-quasi-nucleon collisions from the C+C, C+p, d+C, and p+C interactions at 4.2 (GeV/c)/N. The research results on charged particle multiplicity and their momentum spectra lead to the conclusion that nearly 60% of all three-quasi-nucleon events are due to collisions where two nucleons behave like a whole object, called flucton, which has been predicted by D.I.Blokhintsev. Mean values of one-particle longitudinal momenta of the products and their mean multiplicities for the subreactions in which fluctons take part are lower by #approx#30% compared to the subreactions where two nucleons interact not as a whole object, but in a successive way. Production of the cumulative particles is due to flucton interactions, especially when fluctons ...

143

Plasma dynamics in the PF-1000 device under full-scale energy storage: II. Fast electron and ion characteristics versus neutron emission parameters and gun optimization perspectives  

International Nuclear Information System (INIS)

Electron and ion beam dynamics of the PF-1000 facility were investigated for the first time at its upper energy limit (?1 MJ) in relation to neutron emission, the pinch's plasma ('target') characteristics and some other parameters with the help of a number of diagnostics with ns temporal resolution. Special attention was paid to the temporal and the spatial cross correlations of different phenomena. Results of these experiments are in favour of a neutron emission model based on ion beam-plasma interaction with three important features: (1) the plasma target is hot and confined during a few 'inertial confinement times'; (2) the ions of the main part of the beam are magnetized and entrapped around the pinch plasma target for a period longer than the characteristic time of the plasma inductive storage system and (3) ion-ion collisions (both fusion collisions, due to head-on impacts and Coulomb collisions) ...

2007-06-21

144

Preparation and dosimetry of radiotherapeutic particles for arthropaties; Preparacion y dosimetria de particulas radioterapeuticas para artropatias  

Energy Technology Data Exchange (ETDEWEB)

It was developed a new formulation of macro aggregates of Samarium 153 ({sup 153} Sm-MH) for the arthropaties treatment. The radio pharmaceutic was prepared by reaction of Samarium 153 chloride (SmCl{sub 3}) in aqueous environment with sodium boron hydride in NaOH 0.5 N. The microscopic analysis shown that the particles have an average size of 4% m (range 1-14 {mu} m). The velocity of sedimentation was 0.008 cm/min with high stability in vitro in human serum. The biological studies in healthy rabbits, shown that the complex is retained inside the articulation still eight days after of the administration of the radiopharmaceutical. Likewise, it is presented the data of absorbed dose in the different target organs, which was determined by thermoluminescent dosimetry (TLD) through the use of a REMCAL phantom (radiation equivalent manikin calibration). (Author)

1999-07-01

145

K-shell x-ray production cross sections of selected elements from Ti to Y for 0.5- to 2.5-MeV alpha-particle bombardment  

International Nuclear Information System (INIS)

K-shell x-ray production cross sections and K#beta#/K#alpha# ratios have been measured for thin targets of Ti, V, Cr, Fe, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, and Y for 0.5- to 2.5-MeV alpha particles. The experimental values are compared to the nonrelativistic plane-wave Born approximation (PWBA), the binary-encounter approximation, and the PWBA with binding energy and Coulomb deflection corrections. The PWBA with corrections provides the best agreement with the experimental cross sections.

146

High-Performance, Superparamagnetic, Nanoparticle-Based Heavy Metal Sorbents for Removal of Contaminants from Natural Waters  

Energy Technology Data Exchange (ETDEWEB)

We describe the synthesis and characterization of superparamagnetic iron oxide nanoparticle based heavy metal sorbents with various surface chemistries that demonstrate an excellent affinity for the separation of heavy metals in contaminated water systems (i.e. spiked Columbia river water). The magnetic nanoparticle sorbents are prepared from an easy to synthesize iron oxide precursor, followed by a simple, one-step ligand exchange technique to introduce the organic surface functionality of interest chosen to target either specific or broader classes of heavy metals. Functionalized superparamagnetic nanoparticles are excellent sorbent materials for the extraction of heavy metal contaminants from environmental and clinical samples since they are easily removed from the media once bound to the contaminant by simply applying a magnetic field. These engineered magnetic nanoparticle sorbents have an ...

2010-06-01

147

Evaluating the cytotoxicity of palladium/magnetite nano-catalysts intended for wastewater treatment  

International Nuclear Information System (INIS)

Palladium/magnetite nanoparticulate catalysts were developed for efficient elimination of halogenated organic pollutants from contaminated wastewater. Particle recovery from treated water can be ensured via magnetic separation. However, in worst-case scenarios, this catalyst removal step might fail, leading to particle release into the environment. Therefore, a toxicological study was conducted to investigate the impact of both pure magnetite and palladium/magnetite nanoparticle exposure upon human skin (HaCaT) and human colon (CaCo-2) cell lines and a cell line from rainbow trout gills (RTgill-W1). To quantify cell viability after particle exposure, three endpoints were examined for all tested cell lines. Additionally, the formation of reactive oxygen species was studied for the human cells. The results showed only minor effects of the particles on the tested cell systems and ...

2010-01-01

148

Synthesis and characterization of pH-dependent glycol chitosan and dextran sulfate nanoparticles for effective brain cancer treatment.  

Science.gov (United States)

A novel drug delivery system for the treatment of brain tumors was formulated by methotrexate (MTX)-loaded polymeric nanoparticles (NPs) based on Glycol chitosan (GCS) and Dextran sulfate (DS). The physicochemical properties of resulting particles were investigated, evidencing the contribution of these nanoparticles for brain targeting. In vitro release of MTX was also evaluated. The GCS-DS nanoparticles have been developed based on the modulation of ratio show promise as a system for controlled delivery of the drug to the brain. PMID:21782844

2011-07-19

149

Spectroscopy of light exotic nuclei  

International Nuclear Information System (INIS)

Neutron-rich He-, Li-, and Be-isotopes in the vicinity of the drip-line have been studied by "1"2C- and "1"4C-induced multi-nucleon transfer reactions on "1"0Be and "1"3","1"4C-targets. This study revealed unknown excited states in "8","1"0He, "1"0","1"1Li and in "1"3","1"4Be. Both excitation energies and widths have been measured. In some cases most probable spins and parities could be assigned to the particle-unstable states observed. (orig.).

1996-01-15

150

Dynamics of high-energy nucleus-nucleus collisions  

Energy Technology Data Exchange (ETDEWEB)

The authors use a Glauber multiple-collision model to examine the dynamics of nucleus-nucleus collisions. The model introduces a stopping law, which describes how a baryon loses energy in a baryon-baryon collision, and a particle production law, which is based on the baryon energy loss. The model gives results on the longitudinal energy loss which compare well with the recent WA80 experimental data for /sup 16/O on various targets at 60 and 200 GeV per nucleon. The stopping law that is needed to fit the experimental zero-degree spectra reveals that the degree of stopping in these high-energy nuclear collisions is high.

1988-01-01

151

Coherent bremsstrahlung in {alpha}+p reactions at 50 MeV/nucleon  

Energy Technology Data Exchange (ETDEWEB)

Bremsstrahlung emitted in the {alpha}+p reaction at 50 MeV/nucleon was studied using a 200 MeV {alpha}-particle beam and a liquid hydrogen target. Double-differential photon cross sections were measured over a wide range of angles and energies. Coherent bremsstrahlung was found to be strong for all photon energies. The cross section is enhanced at the highest photon energies and is characteristic of direct capture to the unbound {sup 5}Li ground and first excited state. With direct capture as a limiting case of coherent bremsstrahlung a consistent reaction picture can be obtained.

1999-07-26

152

Ion temperature anisotropy in high power helium neutral beam fuelling experiments in JET  

Energy Technology Data Exchange (ETDEWEB)

During helium beam fuelling experiments in JET, distinctive anisotropic features have been observed in the velocity distribution function describing both fast and thermal alpha particle populations. During the initial fuelling phase the central helium ion temperature observed perpendicular to the magnetic field is higher than the central electron temperature, while the central helium ion temperature observed parallel to the magnetic field is lower than or equal to the central electron temperature. In order to verify temperature measurements of both perpendicular and parallel lines of sight, other independent methods of deducing the ion temperature are investigated: deuterium ion temperature, deuterium density, comparison with neutron rates and profiles (influence of a possible metastable population of helium). 6 refs., 7 figs.

1994-07-01

153

Design considerations for the magnetic system of a prototype x-ray free electron laser  

Energy Technology Data Exchange (ETDEWEB)

A number of difficult technical challenges need to be solved in the fields of accelerator and free-electron laser (FEL) technologies in order to build an X-ray FEL. One of the tasks well suited to the Advanced Photon Source Low Energy Undulator Test Line (LEUTL) is to take the intermediate step of solving some of the problems of single-pass FEL operation in the ultraviolet range. The existing Advanced Photon Source (APS) linac, in addition to its role of supply positrons for the APS storage ring, will also be used to generate the particle beam for the LEUTL. Here, the design of the magnetic system for the high gain soft x-ray free electron laser is described.

1997-04-01

154

Collisionless driven reconnection in an open system  

Energy Technology Data Exchange (ETDEWEB)

Particle simulation studies of collisionless driven reconnection in an open system are presented. Collisionless reconnection evolves in two steps in accordance with the formation of two current layers, i.e., an ion current layer in the early ion phase and an electron current layer in the late electron phase. After the electron current layer is formed inside the ion current layer, the system relaxes gradually to a steady state when convergent plasma flow is driven by an external electric field with a narrow input window. On the other hand, when the convergent plasma flow is driven from the wide input window, magnetic reconnection takes place in an intermittent manner, due to the frequent formation of magnetic islands in the vicinity of neutral sheet. (author)

2000-06-01

155

The PAMELA space experiment: first year of operation  

Energy Technology Data Exchange (ETDEWEB)

On the 15th of June 2006 the PAMELA experiment, mounted on the Resurs DK1 satellite, was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. PAMELA is a satellite-borne apparatus designed to study charged particles in the cosmic radiation, to investigate the nature of dark matter, measuring the cosmic-ray antiproton and positron spectra over the largest energy range ever achieved, and to search for antinuclei with unprecedented sensitivity. The apparatus comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. The combination of these devices allows charged particle identification over a wide energy range.

2008-05-15

156

Steady particulate flows in a horizontal rotating cylinder  

Energy Technology Data Exchange (ETDEWEB)

Results of discrete element method (DEM) simulation and magnetic resonance imaging (MRI) experiments are compared for monodisperse granular materials flowing in a half-filled horizontal rotating cylinder. Because opacity is not a problem for MRI, a long cylinder with an aspect ratio {approximately}7 was used and the flow in a thin transverse slice near the center was studied. The particles were mustard seeds and the ratio of cylinder diameter to particle diameter was approximately 50. The parameters compared were dynamic angle of repose, velocity field in a plane perpendicular to the cylinder axis, and velocity fluctuations at rotation rates up to 30 rpm. The agreement between DEM and MRI was good when the friction coefficient and nonsphericity were adjusted in the simulation for the best fit. {copyright} {ital 1998 American Institute of Physics.}

1998-06-01

157

Mechanical Properties of Nanocrystal Supercrystals  

Energy Technology Data Exchange (ETDEWEB)

Colloidal nanocrystals attract significant interest due to their potential applications in electronic, magnetic, and optical devices. Nanocrystal supercrystals (NCSCs) are particularly appealing for their well ordered structure and homogeneity. The interactions between organic ligands that passivate the inorganic nanocrystal cores critically influence their self-organization into supercrystals, By investigating the mechanical properties of supercrystals, we can directly characterize the particle-particle interactions in a well-defined geometry, and gain insight into both the self-assembly process and the potential applications of nanocrystal supercrystals. Here we report nanoindentation studies of well ordered lead-sulfide (Pbs) nanocrystal supercrystals. Their modulus and hardness were found to be similar to soft polymers at 1.7 GPa and 70 MPa respectively and the fractures toughness was 39 KPa/m1/2, revealing the extremely brittle nature of ...

2009-12-30

158

Low-lying states of {sup 109}Sn from the {sup 106}Cd({alpha},n{gamma}) reaction  

Energy Technology Data Exchange (ETDEWEB)

Measurements of {gamma}-ray, {gamma}{gamma}-coincidence and internal conversion electron spectra from the {sup 106}Cd({alpha},n{gamma}){sup 109}Sn reaction were carried out at 15-20 MeV {alpha}-particle bombarding energies with Ge(HP) {gamma}-ray and superconducting magnetic lens plus Si(Li) electron spectrometers. The energies, relative intensities, internal conversion coefficients and coincidence relations of the {sup 109}Sn transitions were determined, and a more complete, consistent level scheme has been deduced. Spin and parity values have been determined from the internal conversion coefficients, the bombarding-energy dependence of the side-feeding intensities of the states and the available {gamma}-ray angular distribution data. The level scheme was interpreted in the framework of the quasi-particle shell model.

1999-02-01

159

Enzyme-induced growth of silver nanoparticles studied on single particle level  

Energy Technology Data Exchange (ETDEWEB)

Based on their interesting properties, metal nanoparticles show the potential as an analytical tool in electronic (Burmeister et al. 2004), optical (Yguerabide and Yguerabide 1998), and catalytic applications (Liu 2006). Their characteristics depend on the composition, shape, and size of the single particles. These various properties are utilized in many different approaches such as optics, magnetics (Lang et al. 2007), and laser technology (Csaki et al. 2007). We investigated an alternative method for the synthesis of nanoparticles. In this case, an enzyme, horseradish peroxidase, induces a silver deposition and replaces a metal nanoparticle as the reaction seed. Depending on the reaction time, we could obtain particles in a range of few nanometers up to more than 250 nm. For a better understanding of the enzymatic silver deposition process, the silver particles produced by this process were analyzed ...

2009-05-15

160

Development of large-capacity refrigeration at 1.8 K for the Large Hadron Collider at CERN  

CERN Document Server

CERN, the European Laboratory for Particle Physics, is working towards the construction of the Large Hadron Collider (LHC), a high-energy, high-luminosity particle accelerator and collider [1] of 26.7 km circumference, due to start producing frontier physics, by bringing into collision intense proton and ion beams with centre-of-mass energies in the TeV-per-constituent range, at the beginning of the next century. The key technology for achieving this ambitious scientific goal at economically acceptable cost is the use of high-field superconducting magnets using Nb-Ti conductor operating in superfluid helium [2]. To maintain the some 25 km of bending and focusing magnets at their operating temperature of 1.9 K, the LHC cryogenic system will have to produce an unprecedented total refrigeration capacity of about 20 kW at 1.8 K, in eight cryogenic plants distributed around the machine circumference [3]. ...

1996-01-01

162

Structure and magnetic properties of nanostructural strontium ferrite prepared by mechanochemical treatment  

International Nuclear Information System (INIS)

Full text: It was recently-established for hexagonal barium ferrite-industrially important magnetically hard material that refinement of the crystallite dimensions into the nanoscale regime, typically #<=# 10 nm, leads after heat treatment at temperatures 800-1000 deg C to significant coercivity increase of up to 6.5 kOe (#approx#3-4 times) with saturation magnetisation values of 50-55 emu/g (#approx#95% of bulk at room temperature). High-energy mechanochemical processing has been applied to prepare nanostructural (nanocrystalline-amorphous) composites. High resolution electron microscopy studies reveal that the enhancement of the final magnetic properties was due to formation of magnetically noninteracting #approx#l,#mu#m Ba-ferrite particles with 5-10 nm amorphous surface layer - depending on annealing parameters. Similar situation was established also for ball milled strontium ferrite ...

163

Energy and angular distributions of neutrons from 90 MeV proton and 140 MeV alpha-particle bombardment of nuclei  

International Nuclear Information System (INIS)

We measured neutron time-of-flight spectra from 90 MeV protons and 140 MeV alpha particles bombarding thin targets of Al, Ni, Zr, and Bi at laboratory angles between 20_0 and 135_0. The low-energy (5 to 45 MeV) portions of the spectra were measured with 5 cm diameter by 5 cm deep NE-213 counters at 1 m flight paths with n-#betta# pulse-shape discrimination. The high-energy (35 to 150 MeV) portions of the spectra were measured with 12.7 cm diameter by 10.2 cm deep NE-102 counters at flight paths of 2.0 to 5.0 m. The proton-induced measured neutron spectra reveal three distinct energy regions: a low-energy evaporation region, a high-energy region dominated by the quasifree scattering process, and an intermediate-energy region dominated by multistep, preequilibrium processes. In the latter two regions, the spectra show strong angular dependence. The alpha-particle induced neutron spectra show these same distinct energy regions ...

164

Target fabrication of low-density and nano porous materials to generate extreme ultraviolet (EUV)  

Energy Technology Data Exchange (ETDEWEB)

Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has a merit to mitigate heat effect of the first EUV mirror. The ...

2006-06-15

165

Target fabrication of low-density and nano porous materials to generate extreme ultraviolet (EUV)  

International Nuclear Information System (INIS)

Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has a merit to mitigate heat effect of the first EUV mirror. The ...

2006-06-01

166

Stimulated radiation of high - current relativistic electron beams  

International Nuclear Information System (INIS)

The most propagated mechanisms of stimulated radiation of electron beam such as Cherenkov one-particle and collective effects, ondulator and magnetic bremsshrahlung radiations, Doppler anomalous effect, Thompson and Raman scattering and radiation are discussed. Relation of spontaneous radiation mechanisms of individual electron and stimulated radiation effects in electron beams has been elucidated, grounds of linear electrodynamics of radiative beam instabilities are stated, and main mechanisms of their nonlinear stabilization are elucidated as well. Various simulated processes in electron beams are considered from the unique point of view using a simple mathematical apparatus and such physical laws as conservation and Newton laws.

1987-01-01

167

Nondestructive Technique Survey for Assessing Integrity of Composite Firing Vessel  

Energy Technology Data Exchange (ETDEWEB)

The repeated use and limited lifetime of a composite tiring vessel compel a need to survey techniques for monitoring the structural integrity of the vessel in order to determine when it should be retired. Various nondestructive techniques were researched and evaluated based on their applicability to the vessel. The methods were visual inspection, liquid penetrant testing, magnetic particle testing, surface mounted strain gauges, thermal inspection, acoustic emission, ultrasonic testing, radiography, eddy current testing, and embedded fiber optic sensors. It was determined that embedded fiber optic sensor is the most promising technique due to their ability to be embedded within layers of composites and their immunity to electromagnetic interference.

2000-08-01

168

Neutrinos produced by nuclei injected by young pulsars inside compact massive binaries  

Energy Technology Data Exchange (ETDEWEB)

We consider propagation of relativistic heavy nuclei injected by a young pulsar into the radiation field of a massive companion. If the binary system (BS) is compact enough, then the nuclei suffer multiple photodisintegrations in collisions with thermal photons coming from the massive star (MS). Due to the propagation effects of charged particles in the magnetic field of the MS some hadrons can impinge onto the MS surface at large angles. We calculate the fluxes of produced neutrinos as a function of the viewing angle measured from the plane of the BS. It is found that significant fluxes of neutrinos should be also expected in the case of non-eclipsing BSs.

2005-06-15

169

Expansion Rate Measurements at Moderate Pressure of Nonneutral Electron Plasmas in the Electron Diffusion Gauge (EDG) Experiment  

Energy Technology Data Exchange (ETDEWEB)

Measurements of the expansion rate of pure-electron plasmas have been performed on the Electron Diffusion Gauge (EDG) device at background helium gas pressures in the 5 x 10(superscript -8) Torr to 1 x 10(superscript -5) Torr range, where plasma expansion due to electron-neutral collisions dominates over plasma expansion due to trap asymmetries. It is found that the expansion rate, defined as the time rate of change of the particles' mean-square radius, scales approximately linearly with pressure and inversely as the square of the magnetic field strength in this regime, in agreement with classical predictions.

2001-05-18

170

Enriched lithium collection from lithium plasma flow  

International Nuclear Information System (INIS)

In order to understand the physical processes concerned with the selective heating by ion cyclotron resonance and with the subsequent collection of heated particles, experiments were carried out with the extraction of lithium samples, enriched with "6Li isotopes. Probe and integral extractors allow to collect enriched Li at the end of the selective heating region. Surface density distribution on the collector and local isotopic content of lithium are measured, as a function of the screen height and the retarding potential. Dependence of the collected amount of lithium and of its isotopic content on the value of the magnetic field is also measured. 4 figs., 2 tabs., 5 refs.

171

Decontamination of Johnston Island Coral: a preliminary study  

International Nuclear Information System (INIS)

A preliminary investigation was completed on the characterization and decontamination of coral samples from Johnston Island. These samples were found to contain individual particles (2 to 0.25 mm) of contaminated coral as well as a piece of contaminated magnetic metal. They ranged in activity from about 70 to 811 nCi Am-241. The decontamination methods investigated were froth flotation, ferrite treatment, attrition scrubbing, ultrasonic treatment and dry sieving. Dry sieving, the more effective technique, separated about 42 wt % of the coral into a decontaminated fraction. This fraction (>4 mm) contained about 0.5% of the total activity. 7 refs., 3 tabs.

172

Asymmetric rotor model for decoupled bands in transitional odd-mass nuclei  

International Nuclear Information System (INIS)

The high-spin states in transitional odd-mass nuclei are studied in terms of an odd quasi-particle coupled to an asymmetric rotor with a variable moment of inertia (VMI). In order to take into account the VMI, the basis states are expanded in terms of the core eigenfunctions. Excitation energies, quadrupole moments, magnetic moments, B(E2) values and B(M1) values are calculated and compared with the experimental data for nuclei in Au and La regions. On comparison with other descriptions it is found that the treatment with VMI provides a more satisfactory explanation of the data. (Auth.).

173

Measurement and analysis of alpha particle induced reactions on praseodymium  

International Nuclear Information System (INIS)

Excitation functions (EFs) for the reaction "1"4"1Pr(#alpha#, n)"1"4"4Pm and "1"4"1Pr(#alpha#, 2n)"1"4"3Pm have been measured using "1"4"1Pr as a target up to 50 MeV #alpha#-particle energy. Stacked foil activation technique and #gamma#-ray spectroscopy using 100 cm"3 Ge (Li) detector, has been used. Excitation functions are also calculated theoretically using Blann's geometry dependent hybrid (GDH) model code ALICE-91, with and without inclusion of pre-equilibrium particle emission. It has been observed that high-energy tails of the EFs are dominated by pre-equilibrium reaction mechanism. With the accepted set of input parameter, initial exciton number n_0=4 (2p + 2n + 0h), a good qualitative agreement is found. However, quantitative agreement for this magic nucleus"1"4"1Pr is also good when theoretical calculations are normalized by a multiple factor of 0.5. (author)

2005-04-01

174

Negative ion source electrode  

Energy Technology Data Exchange (ETDEWEB)

The present invention concerns a negative ion source electrode which can be preferably used in a neutral particle injection device using negative ions for a thermonuclear reactor. Negative ion beams are deflected to the direction opposite to the deflecting direction by magnetic fields by using an electron suppression electrode having electrode holes with the position previously displaced before negative ion beams are accelerated to have a high energy by an accelerator thereby correcting the orbit of the negative ion beams easily. In addition, since the deflection correction electrode having the electrode holes is disposed, a proper voltage is applied to the deflection correction electrode to correct the orbit of the negative ion beams conveniently. Since the deflection correction electrode has a simple structure of a thin flat plate having electrode holes, the orbit of negative ion beams can be corrected efficiently by an extremely simple ...

1997-01-17

175

Microstructure and magnetic properties of nanocrystalline Fe75Si20M5 (M = Al, B, Cr) powders  

International Nuclear Information System (INIS)

Nanocrystalline Fe75Si20M5 (M = Al, B and Cr) powders were synthesized by mechanical alloying in a planetary ball mill from high purity elemental powders. Evolution of non-equilibrium solid solutions of ?-Fe[Si,(Al, B, Cr)] with a nanocrystalline structure was accompanied by the introduction of a large number of dislocation defects in the course of the milling process. Fe sites get substituted by Si and M (M = Al, B, Cr) atoms during the milling process. The structural change and the resulting disorder are reflected in the changes in the lattice parameter and average magnetic moment of the powders milled for various time periods. The effective magnetic anisotropy increases linearly with the milling time. An increase in coercivity with increasing milling time was observed which could be attributed to the introduction of dislocations and the reduction in the powder particle size during milling. The presence of dislocations ...

2008-08-21

176

Complete suppression of Pfirsch-Schlueter current in a toroidal l=3 stellarator  

Energy Technology Data Exchange (ETDEWEB)

Pfirsch-Schlueter (P-S) current is an inherent property of a finite pressure toroidal equilibrium of tokamak and stellarator. However, it was pointed out recently (V.D. Pustovitov, Nuclear Fusion 36 (1996) 583) that the P-S current would be suppressed completely if the external vertical field could be adjusted to satisfy the condition {omega}=<{omega}> in an l=3 stellarator. Here {omega}=<B tilde{sup 2}>/B{sub 0}{sup 2}-2{epsilon} cos{theta}, l is a pole number, |B tilde| the vacuum helical magnetic field, B{sub 0} the toroidal field, {epsilon} the inverse aspect ratio, {theta} the poloidal angle and <...> denotes the average over the toroidal angle. An example of such a stellarator equilibrium is presented in this paper. For this stellarator equilibrium, behavior of rotational transform and Boozer magnetic spectrum is clarified when the pressure is increased. Both formation of helical ...

1999-10-01

177

Hybrid Simulations of Mini Magnetospheres in the Laboratory  

Science.gov (United States)

We use a massively parallel 3D hybrid particle code, dHybrid, to simulate the deflection of plasma beams by a dipole like magnetic field in a laboratory environment. Dipole magnetic fields, along with a plasma injection source to inflate the magnetic field, are now being studied as means of deflecting solar wind and Energetic Particles away from spacecrafts [1,2,3]. We have considered three setups, consistent with the experiments, with a plasma beam fired at i) a dipole field with no plasma injection, ii) a plasma injection source with no dipole field and iii) a dipole field with a plasma injection source. The hybrid simulations help understand the relevant physical phenomena, and enable extrapolation to space plasma scenarios, where setups are similar but plasma parameters differ significantly. The simulation results consistently show the plasma beam being deflected by the dipole ...

2007-11-01

179

Constraints on target chamber first wall and target designs that will enable NIF debris shields to survive  

CERN Document Server

Constraints on target chamber first wall and target designs that will enable NIF debris shields to survive

1999-01-01

180

Quasi-ternary nanoparticle superlattices through nanoparticle design  

Energy Technology Data Exchange (ETDEWEB)

Individual nanoscale building blocks exhibit a wide range of size-dependent properties, since their size can be tuned over known characteristic length scales of bulk materials. In the last several years, the possibility of combining different materials in the form of two and three component nanoparticles (NPs) has been extensively explored. Also multi-component materials can be obtained via self-assembly of NPs from their binary colloidal mixtures. These new nanocrystal solids may possess tunable collective properties that originate from interactions between size and composition controlled building blocks. Exchange coupling between neighboring NPs of magnetically soft and hard materials enhances the magnetic energy product of the nanocomposite material. Randomly mixed solids of small and large semiconducting CdSe NPs revealed enhancement of photoluminescence intensity of large semiconductor particles accompanied by ...

2007-06-19

181

Quantum molecular dynamics and molecular interactions studied by NMR and INS[Nuclear magnetic resonance; Proton tunnelling; Hydrogen bond  

Energy Technology Data Exchange (ETDEWEB)

The wavefunction of a particle extends into the classically forbidden barrier region of the potential energy surface. The consequence of this partial delocalisation is the phenomenon of quantum tunnelling, an effect which enables a particle to penetrate a potential barrier of magnitude greater than the energy of the particle. The tunnelling probability is an exponential function of the particle mass. The effect is therefore an important contribution to the behaviour of light atoms, in particular the proton. The hydrogen bond has long been appreciated to be an essential component of many biological and chemical systems, and the proton transfer reaction in the hydrogen bond is fundamental to many of these processes. The proton behaviour in the hydrogen bonds of benzoic acid, acetylacetone and calix-4-arene has been studied. A variety of techniques, both experimental and computational, were adopted for the ...

2002-07-01

182

Crystalline beam ground state  

Energy Technology Data Exchange (ETDEWEB)

In order to employ molecular dynamics (MD) methods, commonly used in condensed matter physics, we have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. We include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations using MD methods has been performed to obtain the equilibrium crystalline beam structure. The effect of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time dependent. The ground ...

1993-06-11

183

Particle Detection with drift Chambers  

CERN Document Server

Particle Detection with drift Chambers

2008-01-01

184

Apoferritin-Templated Yttrium Phosphate Nanoparticle Conjugates for Radioimmunotherapy of Cancers  

Energy Technology Data Exchange (ETDEWEB)

We report a templated-synthetic approach based on apoferritin to prepare radionuclide nanoparticle (NP) conjugates. Non-radioactive yttrium (89Y) was used as model target and surrogate for radioyttrium (90Y) to prepare the nanoparticle conjugate. The center cavity and multiple channel structure of apoferritin offer a fast and facile method to precipitate yttrium phosphate by diffusing yttrium and phosphate ions into the cavity of apofrritin, resulting a core-shell nanocomposite. The yttrium phosphate/apoferritin nanoparticle was functionalized with biotin for further application. The synthesized nanoparticle was characterized by transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS). We found that the resulting nanoparticles were uniform in size, with a diameter of around 8 nm. We tested the pre-targeting capability of the biotin-modified yttrium phosphate/apoferritin nanoparticle (yttrium phosphate/apoferritin ...

2008-05-01

185

Energy and angular distributions of neutrons from 90-MeV proton and 140-MeV alpha-particle bombardment of nuclei  

Energy Technology Data Exchange (ETDEWEB)

Neutron time-of flight spectra were measured from 90 MeV protons and 140 MeV alpha-particle bombardment of Al, Ni, Zr, and Bi at laboratory angles between 20/sup 0/ and 130/sup 0/. The proton induced neutron spectra reveal three distinct energy regions; a low energy evaporation region, a high-energy region dominated by quasi-free scattering processes and an intermediate-energy region dominated by multi-step, pre-equilibrium processes. In the latter two regions, the spectra show strong angular dependence. The alpha-induced neutron spectra show these same distinct energy regions plus an exponential fall-off above the beam energy per nucleon. The high-energy portions of the forward-angle neutron and proton cross sections are in ratios consistent with the assumption that single nucleon-nucleon scattering dominates. For heavy-mass targets, the low-energy evaporation regions show neutron yields larger than proton yields. The proton-to-neutron ratios ...

1982-01-01

186

Energy and angular distributions of neutrons from 90-MeV proton and 140-MeV alpha-particle bombardment of nuclei  

International Nuclear Information System (INIS)

Neutron time-of flight spectra were measured from 90 MeV protons and 140 MeV alpha-particle bombardment of Al, Ni, Zr, and Bi at laboratory angles between 20"0 and 130"0. The proton induced neutron spectra reveal three distinct energy regions; a low energy evaporation region, a high-energy region dominated by quasi-free scattering processes and an intermediate-energy region dominated by multi-step, pre-equilibrium processes. In the latter two regions, the spectra show strong angular dependence. The alpha-induced neutron spectra show these same distinct energy regions plus an exponential fall-off above the beam energy per nucleon. The high-energy portions of the forward-angle neutron and proton cross sections are in ratios consistent with the assumption that single nucleon-nucleon scattering dominates. For heavy-mass targets, the low-energy evaporation regions show neutron yields larger than proton yields. The proton-to-neutron ratios observed ...

187

Field-effect research at the High Voltage Transmission Research Center  

Energy Technology Data Exchange (ETDEWEB)

This report presents information obtained during five different studies of field effects from high voltage transmission lines performed at EPRI's High Voltage Transmission Research Center. The first study is the development of a methodology for the evaluation of the expected frequency of occurrence of specific short-term effects of spark discharges and induced currents caused by overhead high voltage transmission lines. The methodology is divided into the analysis of the expected frequency of occurrence of situations in which induction effects may occur, and the analysis of the expected severity of the effect. The second study is of the electric field in the surface and on the immediate proximity of the strands of stranded conductors used for overhead high voltage lines. In particular, the cases of deformations of stranded conductors, caused by air expansion or by popped out strands, are analyzed for the purpose of determining the conditions for occurrence of corona in fair ...

1991-02-01

188

Spectroscopy of neutron-rich {sup 59-63}Mn isotopes  

Science.gov (United States)

The neutron-rich Mn isotopes from A=59 to 63 have been studied through multi-nucleon transfer reactions by bombarding a {sup 238}U target with a beam of {sup 70}Zn at an energy of E{sub lab}=460 MeV. Prompt {gamma} rays measured by the CLARA array have been identified unambiguously for each nucleus, using coincidence relationships with ions detected in the high-acceptance magnetic spectrometer PRISMA. The new data extends the knowledge of the low-lying level structure of Mn isotopes, which is discussed in terms of the systematics of the region. Results are compared with large-scale shell-model calculations using different effective interactions and valence spaces.

2008-08-15

189

Spectroscopy of neutron-rich "5"9"-"6"3Mn isotopes  

International Nuclear Information System (INIS)

The neutron-rich Mn isotopes from A=59 to 63 have been studied through multi-nucleon transfer reactions by bombarding a "2"3"8U target with a beam of "7"0Zn at an energy of E_l_a_b=460 MeV. Prompt #gamma# rays measured by the CLARA array have been identified unambiguously for each nucleus, using coincidence relationships with ions detected in the high-acceptance magnetic spectrometer PRISMA. The new data extends the knowledge of the low-lying level structure of Mn isotopes, which is discussed in terms of the systematics of the region. Results are compared with large-scale shell-model calculations using different effective interactions and valence spaces.

2008-08-01

190

PET and MRI in cardiac imaging: from validation studies to integrated applications  

International Nuclear Information System (INIS)

Positron emission tomography (PET) is the gold standard for non-invasive assessment of myocardial viability and allows accurate detection of coronary artery disease by assessment of myocardial perfusion. Magnetic resonance imaging (MRI) provides high resolution anatomical images that allow accurate evaluation of ventricular structure and function together with detection of myocardial infarction. Potential hybrid PET/MR tomography may potentially facilitate the combination of information from these imaging modalities in cardiology. Furthermore, the combination of anatomical MRI images with the high sensitivity of PET for detecting molecular targets may extent the application of these modalities to the characterization of atherosclerotic plaques and to the evaluation of angiogenetic or stem cell therapies, for example. This article reviews studies using MRI and PET in parallel to compare their performance in cardiac applications together with the ...

2009-03-01

191

New neutron-rich isotopes in the scandium-to-nickel region, produced by fragmentation of a 500 MeV/u {sup 86}Kr beam  

Energy Technology Data Exchange (ETDEWEB)

We have measured production cross-sections of the new neutron-rich isotopes {sup 58}Ti, {sup 61}V, {sup 63}Cr, {sup 66}Mn, {sup 69}Fe, {sup 71}Co and neighbouring isotopes that have been identified as projectile fragments from reactions between a 500 MeV/u {sup 86}Kr beam and a beryllium target. The isotope identification was performed with the zero-degree magnetic spectrometer FRS at GSI, using in addition time-of-flight and energy-loss mesurements. The experimental production cross-sections for the new nuclides and neighbouring isotopes are compared with an empirical parameterization. The resulting prospects for reaching even more neutron-rich isotopes, such as the doubly-magic nuclide {sup 78}Ni, are discussed. (orig.).

1991-10-01

192

New neutron-rich isotopes in the scandium-to-nickel region, produced by fragmentation of a 500 MeV/u sup 86 Kr beam  

Energy Technology Data Exchange (ETDEWEB)

We have measured production cross-sections of the new neutron-rich isotopes {sup 58}Ti, {sup 61}V, {sup 63}Cr, {sup 66}Mn, {sup 69}Fe, {sup 71}Co and neighbouring isotopes that have been identified as projectile fragments from reactions between a 500 MeV/u {sup 86}Kr beam and a beryllium target. The isotope identification was performed with the zero-degree magnetic spectrometer FRS at GSI, using in addition time-of-flight and energy-loss measurements. The experimental production cross-sections for the new nuclides and neighbouring isotopes are compared with an empirical parametrization. The resulting prospects for reaching even more neutronrich isotopes, such as the doubly-magic nuclide {sup 78}Ni, are discussed. (orig.).

1992-07-01

193

New neutron-rich isotopes in the scandium-to-nickel region, produced by fragmentation of a 500 MeV/u "8"6Kr beam  

International Nuclear Information System (INIS)

We have measured production cross-sections of the new neutron-rich isotopes "5"8Ti, "6"1V, "6"3Cr, "6"6Mn, "6"9Fe, "7"1Co and neighbouring isotopes that have been identified as projectile fragments from reactions between a 500 MeV/u "8"6Kr beam and a beryllium target. The isotope identification was performed with the zero-degree magnetic spectrometer FRS at GSI, using in addition time-of-flight and energy-loss measurements. The experimental production cross-sections for the new nuclides and neighbouring isotopes are compared with an empirical parametrization. The resulting prospects for reaching even more neutronrich isotopes, such as the doubly-magic nuclide "7"8Ni, are discussed. (orig.).

194

Nano photonic sensors for microdamage detection : an exploratory simulation.  

Energy Technology Data Exchange (ETDEWEB)

Nano photonic materials are synthetically manufactured crystals at the nano scale with the target of creating a microstructure with a special electro-magnetic periodicity. Such nano photonic materials have the ability to control light propagation and thus are capable of creating photonic bandgaps in the frequency domain. We propose using nano photonic crystals as sensors to detect microdamage in composite materials. We demonstrate using a simulation model that a nano photonic sensor attached to a composite bar experiences a significant change in its bandgap profile when damage is induced in the composite bar. The model predicts the frequency response of the nano photonic sensor using the transfer matrix method. A damage metric to evaluate the change in the frequency response is developed. Successful developments of nano photonic sensors allow damage identification at scales not attainable using current sensing technologies.

2005-04-01

195

Milling materials using CO{sub 2} clusters; Materialbearbeitung durch Clusterionenbeschuss  

Energy Technology Data Exchange (ETDEWEB)

The Sputter coefficient of accelerated CO{sub 2} cluster ions hitting surfaces of various materials is investigated. For copper it varies proportional to the 2nd power of the energy between 155 and 260 keV. The rate of erosion for different target materials varies by two orders of magnitude from tungsten to PMMA. Diamond is eroded fairly quickly, while aluminum is eroded less than corundum (Al{sub 2}O{sub 3}). No simple correlation of the sputter coefficient on the bulk material properties is found. For copper the angular distribution of sputtered material is measured and found to be following roughly a cosine distribution. By using masks different microstructures have been produced in cobalt-samarium magnets, diamond and glass. (orig.)

1993-10-01

196

Designing engineering upgradability into magnetic resonance imagers: Impact on future costs  

Energy Technology Data Exchange (ETDEWEB)

MRI is a powerful diagnostic modality of expanding availability. Equipment and installation amount to nearly $2M per site. An important component of diagnostic efficacy is not just equipment costs but also replacement costs, which for x-ray CT amount to 14-20% of the purchase cost per year; and in the early years of that technology reached 30-50%. The authors show how design choices made during the RandD stages of MRI development have allowed them to improve system performance parameters such as data reconstruction, archiving and display speeds, computational capabilities, operator interfaces, imaging sequence flexibility and signal-to-noise levels. Over the last four years these improvements have been made at a retrofit cost well below the target of 6-7% of the purchase price per year.

1987-02-01

197

Programmed improvements of the alternating gradient synchrotron complex at Brookhaven National Laboratory, Upton, New York. Environmental assessment  

Energy Technology Data Exchange (ETDEWEB)

The purpose and need for DOE to undertake the actions described in this document are to improve the efficiency of the Alternating Gradient Synchrotron (AGS) complex. Benefits would include optimization of the AGS scientific program, increased high-energy and nuclear physics experimentation, improved health and safety conditions for workers and users, reduced impact on the environment and the general public, energy conservation, decreased generation of hazardous and radioactive wastes, and completion of actions required to permit the AGS to be the injector to the Relativistic Heavy Ion Collider (RHIC)., Improved efficiency is defined as increasing the AGS`s capabilities to capture and accelerate the proton intensity transferred to the AGS from the AGS booster. Improved capture of beam intensity would reduce the beam losses which equate to lost scientific opportunity for study and increased potential for radiation doses to workers and the general public. The action would also refurbish ...

1994-03-01

198

A shockproof container for the transport and storage of fragile or reactive target foils  

CERN Document Server

A shockproof container for the transport and storage of fragile or reactive target foils

1971-01-01

199

The pisa experiment: spallation products identified by bragg curve spectroscopy  

International Nuclear Information System (INIS)

In the framework of spallation neutron sources and accelerator-driven systems, the international PISA (Proton-induced Spallation) collaboration has initiated measurements of total- and double-differential cross-sections for products of spallation reactions in a wide range of target nuclei (GU) at the COSY proton accelerator in Julich (Germany). The purpose is to study secondary particle production created in structural, window and target materials via proton beams up to 2.5 GeV of incident kinetic energy. Residual nuclei [H, He up to intermediate mass fragment (IMF)] production cross-sections are of great importance for estimating the damage to target and structure materials involving the planned spallation neutron sources, given that the lifetime of window and target materials is directly associated to those cross-sections. The demand for reliable theoretical predictions on ...

2004-05-17

200

Magnetic Levitation of MC3T3 Osteoblast Cells as a Ground-Based Simulation of Microgravity  

UK PubMed Central (United Kingdom)

Diamagnetic samples placed in a strong magnetic field and a magnetic field gradient experience a magnetic force. Stable magnetic levitation occurs when the magnetic force exactly counter balances...Full Text Available

2009-11-01

201

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering  

Energy Technology Data Exchange (ETDEWEB)

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or ...

1994-01-01

202

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering  

Energy Technology Data Exchange (ETDEWEB)

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or ...

1994-11-22

203

The SysMES framework: System management for networked embedded systems and clusters  

Energy Technology Data Exchange (ETDEWEB)

The ALICE heavy-ion particle physics experiment is currently being built at CERN near Geneva. It will use a PC cluster of 900 dual-processor machines for the last stages of the data readout process and a network of 400 microcomputers for the configuration and control of the cluster nodes. One of the most important objectives to be achieved in such experiments is to guarantee the utilized devices are running correctly during the experiment life-time. A second aspect is the extremely high availability and reliability requirements of the applications being run, the so called high level trigger (HLT). The SysMES framework is a scalable, decentralized, fault tolerant, dynamic, rule based tool set for the monitoring of networks of target systems and applications. The management algorithms consist of the following steps: system and application monitoring, recognition of undesirable states, event (message) generation, local event handling on the ...

2008-07-01

204

Parameter study of the LIFE engine nuclear design  

International Nuclear Information System (INIS)

LLNL is developing the nuclear fusion based Laser Inertial Fusion Energy (LIFE) power plant concept. The baseline design uses a depleted uranium (DU) fission fuel blanket with a flowing molten salt coolant (flibe) that also breeds the tritium needed to sustain the fusion energy source. Indirect drive targets, similar to those that will be demonstrated on the National Ignition Facility (NIF), are ignited at #approx#13 Hz providing a 500 MW fusion source. The DU is in the form of a uranium oxycarbide kernel in modified TRISO-like fuel particles distributed in a carbon matrix forming 2-cm-diameter pebbles. The thermal power is held at 2000 MW by continuously varying the "6Li enrichment in the coolants. There are many options to be considered in the engine design including target yield, U-to-C ratio in the fuel, fission blanket thickness, etc. Here we report results of design variations and compare them in terms of various ...

2010-09-01

205

PIXE analysis of GaAs and ZnSe  

Energy Technology Data Exchange (ETDEWEB)

The optoelectronic compounds of GaAs and ZnSe are difficult to analyze by PIXE (particle-induced X-ray emission) due to the strong absorption of the As and Se K{sub {alpha}} X-rays. As part of a program to investigate optoelectronic materials using ion beam techniques, we have explored the possibility of using the high sensitivity of PIXE to check these materials for stoichiometry and dopant concentrations. The K{sub {alpha}} X-ray intensity ratios of Ga to As and Zn to Se have been investigated using H beams of 0.5 to 2.5 MeV and He beams of 1.0 to 2.5 MeV. The variation in the X-ray intensity ratio with beam energy and target thickness is modelled in terms of the cross section for X-ray production and the absorption coefficients of the X-rays in the target. The results of this model show the experimental conditions that must be satisfied in order that the X-ray intensity ratios are not strongly affected by X-ray ...

1990-01-01

206

PIXE analysis of GaAs and ZnSe  

International Nuclear Information System (INIS)

The optoelectronic compounds of GaAs and ZnSe are difficult to analyze by PIXE (particle-induced X-ray emission) due to the strong absorption of the As and Se K_#alpha# X-rays. As part of a program to investigate optoelectronic materials using ion beam techniques, we have explored the possibility of using the high sensitivity of PIXE to check these materials for stoichiometry and dopant concentrations. The K_#alpha# X-ray intensity ratios of Ga to As and Zn to Se have been investigated using H beams of 0.5 to 2.5 MeV and He beams of 1.0 to 2.5 MeV. The variation in the X-ray intensity ratio with beam energy and target thickness is modelled in terms of the cross section for X-ray production and the absorption coefficients of the X-rays in the target. The results of this model show the experimental conditions that must be satisfied in order that the X-ray intensity ratios are not strongly affected by X-ray absorption; and ...

1989-06-01

207

Construction of a open-quotes black neutron detectorclose quotes at the University of Massachusetts-Lowell Accelerator Laboratory  

International Nuclear Information System (INIS)

In many experiments involving fast neutrons generated in nuclear reactions initiated by accelerator produced charged particle beams, it is important to be able to determine accurately the neutron yield from the target. A detector suitable for such applications should have: a constant efficiency over a large energy range; a fast time response; and the ability to discriminate between gamma rays and neutrons. The authors have constructed a open-quotes black neutron detectorclose quotes based on the design of Poenitz that has these characteristics. At the Lowell Van de Graaff accelerator laboratory neutrons are produced via the "7Li(p,n)"7Be reaction using a pulsed proton beam which impinges on metallic lithium targets. The pulsed beam enables the detector to be used in a time-of-flight spectrometer. Use of BC501 liquid scintillator permits neutron-gamma discrimination. The scintillator is viewed by five RCA 48796 photo tubes. ...

1992-03-16

208

Refining the Magnetic Forming Capability.  

Science.gov (United States)

... Title : Refining the Magnetic Forming Capability. ... Abstract : The purpose of this project was to refine the in-house magnetic forming capability. ...

1972-04-01

210

BIOMAGNETIC RESPONSE OF SIMPLE BIOLOGICAL ...  

Science.gov (United States)

... Examples include magnetic forming tools, magnetic shielding, magnetohydrodynamic propulsion systems, and various magnetic containment ...

1970-01-01

211

/22k : - NASA Technical Reports Server  

Science.gov (United States)

in pulse applications such as magnetic forming. ... In magnetic-forming electric circuitry, the ..... Aspects of Electrohydraulic land Magnetic Forming. ...

212

Particle simulation of edge pedestal formation and plasma rotation dynamics  

International Nuclear Information System (INIS)

Gyrokinetic particle simulation of edge pedestal formation and plasma rotation dynamics will be presented, and compared with experimental observations. Realistic tokamak edge geometry is used which include separatrix/X-point and material wall from EFIT g-eqdsk data. In order to handle adequately the spatially inhomogeneous electric potential in the scrape-off region, the full-f electron technique is used, in addition to the full-f ions. Monte Carlo neutral particles with wall recycling coefficient will be included self-consistently with the plasma kinetics. Ion-ion Coulomb collisions will be particle, momentum and energy conserving. Energy source for the pedestal and scrape-off plasmas is the heat flow from the core plasma, and the particle source is the ionization of the neutral atoms which are either wall recycled and/or gas puffed. The simulation will be self-consistent with the first principles ...

2007-03-26

213

Feasibility study of iron mineral separation from red mud by high gradient superconducting magnetic separation  

International Nuclear Information System (INIS)

Research highlights: #-># Red mud residues (RM) were disposed in alumina production. #-># Utilization of Red mud residues was affected by its iron content. #-># Superconducting magnetic separation (HGSMS) was used in iron separation from RM. #-># RM with high and low iron contents were separated in HGSMS. - Abstract: The disposal of bayer red mud tailings now seriously threats the environment safety. Reduction and recycling of red mud is now an urgent work in aluminum industry. High gradient superconducting magnetic separation (HGSMS) system was applied to separate the extreme fine RM particles (<100 #mu#m) into high iron content part and low iron content part. Two sorts of RM were fed in the HGSMS. The iron oxide contents in concentrates were about 65% and 45% when RM 1 and RM 2 were fed respectively. Meanwhile, the residues contained 52.0% or 14.1% iron oxide in residues after eight separation stages when ...

2011-02-01

214

MAGNETIC RESONANCE IMAGING DEVICE  

J-STORE (Japan)

Full Text Available

2010-08-31

215

Study of the reaction {sup 22}Ne(131 MeV) + {sup 208}Pb with a PIAVE-ALPI test beam and the PRISMA-CLARA set-up  

Energy Technology Data Exchange (ETDEWEB)

An opportunity to study the system {sup 22}Ne+{sup 208}Pb in the proximity of the Coulomb barrier with the PRISMACLARA apparatus was given by a test of the PIAVE-ALPI accelerator in mid-December 2005. The {sup 22}Ne projectiles, having the kinetic energy of 131 MeV, collided with a {sup 208}Pb target 300 {mu}g/cm{sup 2} thick. (The beam was run for {approx}20 hours with a current of {approx}6 particle-nA). The reaction products, mainly originated by scattering or transfer processes, were detected by the PRISMA spectrometer (positioned in the proximity of the grazing angle, {approx}70 degrees), coupled to the CLARA array of germanium detectors.

2005-07-01

216

Spectroscopy of {sup 25}Al and {sup 26,27,28}P using high-energy stripping reactions  

Science.gov (United States)

We report here results of an application of single-nucleon stripping reactions at high energies (65 MeV/u) in inverse kinematics to obtain spectroscopic factors. From measurements of the partial cross-sections for ground and excited states in residual nuclei formed in one-proton stripping reactions, single particle orbits and occupancies of light nuclei have been studied in the s-d shell. Single proton stripping cross-sections of {sup 25}Al and {sup 26,27,28}P on a Be target have been measured using the S800 spectrograph and the NaI(Tl) array at the NSCL. These results indicate that this technique may provide a general tool for the intermediate energy range analogous to transfer (pick-up) reactions at low-energy.

1998-12-21

217

Spectroscopy of "2"5Al and "2"6","2"7","2"8P using high-energy stripping reactions  

International Nuclear Information System (INIS)

We report here results of an application of single-nucleon stripping reactions at high energies (65 MeV/u) in inverse kinematics to obtain spectroscopic factors. From measurements of the partial cross-sections for ground and excited states in residual nuclei formed in one-proton stripping reactions, single particle orbits and occupancies of light nuclei have been studied in the s-d shell. Single proton stripping cross-sections of "2"5Al and "2"6","2"7","2"8P on a Be target have been measured using the S800 spectrograph and the NaI(Tl) array at the NSCL. These results indicate that this technique may provide a general tool for the intermediate energy range analogous to transfer (pick-up) reactions at low-energy.

1998-12-21

218

Polymeric nanosponges as an alternative carrier for improved retention of econazole nitrate onto the skin through topical hydrogel formulation  

British Library Electronic Table of Contents (United Kingdom)

The present study was carried out to exploit the feasibility of using polymeric nanosponges as an alternative carrier for targeting econazole nitrate (EN) to the skin through topical hydrogel formulation. Nanosponges prepared by emulsion solvent diffusion method were evaluated for various physicochemical parameters and in vitro drug release. The nanosponges of EN were discrete free flowing nanosized particles with perforated orange peel like morphology as visualized by SEM. The nanosponge formulated using PVA:EC (3:2) displayed highest in vitro release after 12 ?h in phosphate buffer (pH 6.8) that fitted matrix model. Selected nanosponge was formulated as Carbopol 934 NF hydrogel using varying concentrations of permeation enhancers propylene glycol and N-methyl-2-pyrrolidone. The EN nanosp...

2011-01-01

219

PHOTON-HADRON INTERACTIONS AT RHIC AND LHC ENERGIES.  

Energy Technology Data Exchange (ETDEWEB)

Heavy Ion Collisions at RHIC and LHC energies are potentially an interesting laboratory for the study of QED. In these collisions, a Heavy Ion in one beam sees a highly Lorentz contracted electric field due to an oncoming beam particle. The Electric field reaches a maximum value of E {approx_equal} {gamma}{sub eff} {center_dot} Z {center_dot} e/b{sup 2}, where the apparent Lorentz factor, {gamma}{sub eff} = 2 {center_dot} {gamma}{sub beam}{sup 2} - 1. The collision may be viewed in terms of a flux of photons colliding with a stationary ion target using the equivalent photon approximation, originally introduced by Fermi in 1924. We show that the cross section for Inelastic Electromagnetic Interactions of Heavy Ions are both calculable and have been measured in the first RHIC running period.

2002-03-01

220

Momentum transfer in 30-200 MeV/sup 4/He induced reaction with /sup 59/Co  

Energy Technology Data Exchange (ETDEWEB)

Thick-target recoil ranges of radioactive nuclei produced in 30-200 MeV alpha-particle bombardment of /sup 59/Co have been used to deduce the longitudinal momentum transfer per projectile nucleon (psub(parallel)/A) as a function of residue mass and bombarding energy. The average value of psub(parallel)/A increases monotonically with bombarding energy and reaches a maximum value of proportional160 MeV/c at proportional23 MeV/u, and decreases thereafter. The maximum value of psub(parallel)/A is equal to the incident momentum up to proportional23 MeV/u and saturates at a value of proportional220 MeV/c beyond this energy.

1984-03-01

221

Fast PIN-diode beam loss monitors at Tevatron  

Energy Technology Data Exchange (ETDEWEB)

The article is devoted to results of fine time structure of particle losses in Tevatron with use of fast beam loss monitors (BLM) based on PIN-diodes. An ultimate goal of the new BLMs is to distinguish losses of protons and antiprotons from neighbor bunches with 132 ns bunch spacing in the Tevatron collider upgrade. The devices studied fit well to the goal as they can recognize even seven times closer - 18.9 ns - spaced bunches` losses in the Tevatron fixed target operation regime. We have measured main characteristics of the BLM as well as studied the proton losses over 10 decades of time scale - from dozen of minutes to dozen of nanoseconds. Power spectral density of the losses is compared with spectra of the proton beam motion.

1997-07-01

222

Annihilation of antiprotons in light nuclei  

CERN Document Server

CR-39 detectors have been exposed to a 5.9-MeV antiproton beam using the low energy antiproton ring (LEAR) facility at CERN. At this energy, tracks of antiprotons appear in a CR-39 detector after 135 min of etching in 6 M NaOH at 70C. Fluence of the antiproton beam has been determined using track density. We have also found tracks in the etched CR-39 detector at different depths (250-500 mum). These tracks have resulted from the annihilation of antiprotons with the constituents (H, C and O) of the CR-39 detector. The goal of the experiment is to develop a simple and low-cost method to study properties of antiparticles and those formed after annihilation of these particles with the target matter.

2006-01-01

223

Alpha particles for treatment of disseminated melanoma  

International Nuclear Information System (INIS)

Invading melanoma spreads to local and unpredictable distant location at the early stages of its development. It is justifiable, therefore, to classify the disease as a systemic disorder. This requires a systemic treatment that reaches all melanoma cells irrespective of whether they are singly dispersed and in circulation or already forming solid tumours of various sizes. Targeted radiotherapy affects directly and selectively cancer cells provided an appropriate radionuclide and its carrier are chosen. Melanoma is a pigmented tumour. Methylene blue (MTB)) accumulates selectively in melanoma cells due to its exceptionally high affinity to melanin. MTB serves, therefore, as a carrier for radionuclides. "2"1"1At-MTB has proved to be particularly effective in treating disseminated melanoma when administered systemically and, at the same time, non-toxic to normal non-pigmented and pigmented organs. (authors)

224

CAA broadband noise prediction for aeroacoustic design  

Science.gov (United States)

The current status of a computational aeroacoustics (CAA) approach to simulate broadband noise is reviewed. The method rests on the use of steady Reynolds averaged Navier-Stokes (RANS) simulation to describe the time-averaged motion of turbulent flow. By means of synthetic turbulence the steady one-point statistics (e.g. turbulence kinetic energy) and turbulent length- and time-scales of RANS are translated into fluctuations having statistics that very accurately reproduce the initial RANS target-setting. The synthetic fluctuations are used to prescribe sound sources which drive linear perturbation equations. The whole approach represents a methodology to solve statistical noise theory with state-of-the-art CAA tools in the time-domain. A brief overview of the synthetic turbulence model and its numerical discretization in terms of the random particle-mesh (RPM) and fast random particle-mesh (FRPM) method is given. Results ...

2011-08-01

225

Magnetic properties of FePt nanodots formed by a self-assembled nanodot deposition method  

International Nuclear Information System (INIS)

Fe_5_0Pt_5_0 nanodots dispersed in a SiO_2 film (Fe_5_0Pt_5_0 nanodot film) were formed by a self-assembled nanodot deposition (SAND) method in which Fe_5_0Pt_5_0 and SiO_2 are cosputtered in a high vacuum rf magnetron sputtering equipment. Fe_5_0Pt_5_0 pellets are laid on a SiO_2 target in a sputtering chamber to form the Fe_5_0Pt_5_0 nanodot film in the SAND method. The size and density of Fe_5_0Pt_5_0 nanodot were controlled by changing the ratio of the total area of Fe_5_0Pt_5_0 pellets to that of SiO_2 target. The Fe_5_0Pt_5_0 nanodot size decreases and its density increases when the ratio decreases. As-deposited Fe_5_0Pt_5_0 nanodots self-assembled to a face-centered-cubic phase of single-crystal structure. The Fe_5_0Pt_5_0 nanodot films were annealed to evaluate the nanodot size controllability, the magnetic anisotropy, and the thermal stability. Fully ordered L1_0 face-centered-tetragonal Fe_5_0Pt_5_0 nanodots with ...

2006-08-07

226

Dependence of integral cross sections of the 24 MeV #alpha#-particle inelastic scattering on "1"2C, "1"6O, "1"8O, "1"9F, "2"0Ne and "2"2Ne nuclei on level excitation energy  

International Nuclear Information System (INIS)

Inelastic scattering of #alpha#-particles in 22-24 MeV energy range on "1"8o o, "1"9f, "2"0Ne, "2"2Ne nuclei is investigated. Measurements of excitation functions were conducted for the beam of Leningrad University cyclo otron at several angles in 15-165 deg range of laboratory system with 2.5 deg spacing. The error of determining absolute cross sections equals +-20% for "2"2Ne and +-12% for other nuclei. Angular distributions have the differaction character, are similar in form for all nuclei, the values of differential cross- -sections don't exceed the rutherford values. The dependence of integral cross-sections on the energy of level excitation is similar to the exponential d dependence of cross-sections of production of the given element isotopes on the gergy difference of masses of final nuclear products in the reactions of deeply inelastic transfers with heavy ions. The observed isotopic effect in the value of cross-sections of elastic and inelastic ...

1983-04-01

227

Van Der Pol model of a Cerenkov maser  

Energy Technology Data Exchange (ETDEWEB)

A non-linear analysis of a Cerenkov maser is presented. The system consists of a ring configuration of a cylindrical waveguide filled with a dielectric material. A single transverse-magnetic mode is assumed to propagate in the system. A low-density pencil electron beam travels in part of the ring, confined by a strong axial magnetic field. Using the single-particle description for the beam and the wave equation for the field, we obtain a set of two coupled non-linear differential equations describing the slowly varying amplitude and phase of the electromagnetic mode. The gain per path is assumed to be small and the spatial growth of the field is neglected. The resulting time dependent amplitude includes the exponential gain of the linear stage and the saturation to its maximum value. The time dependent frequency is also calculated. The two equations are combined to a single Van Der Pol equation with a non-linear restoring ...

1995-12-31

228

The magnetic spectrometer PAMELA for the study of cosmic antimatter in space  

Energy Technology Data Exchange (ETDEWEB)

In the framework of the RIM (Russian Italian mission) program, PAMELA is the experiment devoted to the accurate measurement of the positron and antiproton spectra from the very low energy thresh-old of 100 MeV up to more than 50 GeV, and to hunt antinuclei with sensitivity better than 10{sup -7} in the helium/helium ratio. A permanent magnet equipped by microstrip silicon sensors, measures the particle momentum with MDR=400 GV/c on GF=25 cm{sup 2} sr. An accurate ToF system, a 19 X{sub o} deep imaging calorimeter, an aerogel Cherenkov counter and a TRD detector complement the spectrometer in order an efficient e{sup +-}/p{sup +-} separation and some light isotope identification capability. The PAMELA experiment will be carried out on a 700 km high polar orbit, on board of the Earth-observation meteor-3A satellite, to be launched at the end of 1988.

1995-09-01

229

Structure and magnetic properties of polymer matrix nanocomposites  

International Nuclear Information System (INIS)

Structure and magnetic properties of the thermal decomposition products of Fe(III(Co(II) acrylate complex were analysed. The crystalline phases, which were found in the fully processed material, at 643 K, were Fe_3O_4, CoFe_2O_4 and CoO and had a mean particle size of about 30 nm. In the intermediate stages of the thermolysis iron was present in a form of Fe"I"I"I (trivalent low-spin iron), Fe"2"+ (divalent high-spin iron), and Fe_3O_4. The coercivity and remanence were measured versus temperature in the range of 5-300 K, in 1.1 T applied field. Both _MH_c and M_r, decreased showing room temperature values of 0.038 T and 7.49 mT, for coercivity and remanence, respectively. At temperatures below 200 K the hysteresis loops were asymmetrical, opened and shifted towards negative field values. (author)

2001-09-23

230

Observation of the limit cycle in the asymmetric plasma divided by the magnetic filter  

Energy Technology Data Exchange (ETDEWEB)

Asymmetric plasma divided by the magnetic filter (MF) is numerically simulated by the one-dimensional particle-in-cell code VSIM1D. Depending on the asymmetry, the system behaves static or dynamic. In the static state, the potentials of the main plasma and the sub-plasma are given by the sheath potentials, {phi}{sub M} - 3T{sub Me}/e and {phi}{sub S} - 3T{sub Se}/e, respectively, with e being an electron charge and T{sub Me} and T{sub Se} being electron temperatures (T{sub Me} > T{sub Se}). In the dynamics state, while {phi}{sub M} - 3T{sub Me}/e, {phi}{sub S} oscillates periodically between {phi}{sub S,min} - 3T{sub Se}/e and {phi}{sub S,max} - 3T{sub Me}/e. The ions accelerated by the time varying potential gap get into the sub-plasma and excite the laminar shock waves. This periodic phenomenon can be understood as a limit cycle due to transitions between two bifurcated states of {phi}{sub S,min} and {phi}{sub S,max}. (author)

2000-08-01

231

Milliampere class Si{sup -} or B{sup -} negative ion extraction from RF plasma sputter type heavy negative ion source  

Energy Technology Data Exchange (ETDEWEB)

An RF plasma sputter type heavy negative ion source, which can deliver mA-class negative ion beams (12.1 mA, 1.6 mA and 2.3 mA for Cu{sup -}, C{sup -} and C{sub 2}{sup -} currents, respectively) in dc-mode operation, has been developed. In ion source, a dense plasma of 10{sup 11} cm{sup -3} order was generated in the xenon gas pressure of 10{sup -3}-10{sup -2} Pa with an rf (13.56 MHz) power of 200 - 300 W by using an RF coil, and a relatively large sputtering target of 42 mm in diameter was used. As for intense negative ion beams of silicon or boron which are important dopants for semiconductor fabrication, negative ion extraction properties of the negative ion source was investigated. The extracted total negative ion currents of 4.4 mA for a silicon target and 2.8 mA for a LaB{sub 6} target were obtained after electrons were eliminated by magnetic field near the extraction hole. From results of ...

1993-12-31

232

Experimental Study of Hypernuclei Electroproduction by High Precision Spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Jlab experiment E01-011, carried out in 2005 in JLab Hall C, is the second generation of the hypernuclear spectroscopy experiments by the (e,e{prime}K{sup +}) reaction. The (e,e{prime}K{sup +}) reaction is complimentary to the associated production reactions (K{sup -},{pi}{sup -}), ({pi}{sup +},K{sup +}) since, due to a larger momentum transfer to a hyperon, excitations of both spin-non-flip and spin-flip states are possible. The experiment uses high quality and continuous primary electron beam to produce neutron rich hypernuclei on various targets by the electroproduction. The experimental setup consists of splitter magnet, high resolution kaon spectrometer (HKS) and electron spectrometer (Enge) implemented in new configuration, the so called 'Tilt Method'. Production data was taken on multiple targets: CH{sub 2}, {sup 6}Li, {sup 7}Li, {sup 9}Be, {sup 10}B, {sup 12}C and {sup 28}Si. In present study the ...

2009-12-01

233

Waves in pulsar winds  

International Nuclear Information System (INIS)

The radio, optical, x-ray and gamma-ray nebulae that surround many pulsars are thought to arise from synchrotron and inverse Compton emission. The energy powering this emission as well as the magnetic fields and relativistic particles are supplied by a 'wind' driven by the central object. The inner parts of the wind can be described using the equations of MHD, but these break down in the outer parts, when the density of charge carriers drops below a critical value. This paper reviews the wave properties of the inner part (striped wind), and uses a relativistic two-fluid model (cold electrons and positrons) to re-examine the nonlinear electromagnetic modes that propagate in the outer parts. It is shown that in a radial wind, two solutions exist for circularly polarized electromagnetic modes. At large distances one of them turns into a freely expanding flow containing a vacuum wave, whereas the other decelerates, corresponding to a confined flow.

2010-12-01

234

Thermal loads on tokamak plasma-facing components during normal operation and disruptions  

Energy Technology Data Exchange (ETDEWEB)

Power loadings experienced by tokamak plasma-facing components during normal operation and during off-normal events are discussed. A model for power and particle flow in the tokamak boundary layer is presented and model predictions are compared to infrared measurements of component heating. The inclusion of the full three-dimensional geometry of the components and of the magnetic flux surface is very important in the modeling. Experimental measurements show that misalignment of component armour tile surfaces by only a millimeter can lead to significant localized heating. An application to the design of plasma-facing components for future machines is presented. Finally, thermal loads expected during tokamak disruptions are discussed. The primary problems are surface melting and vaporization due to localized intense heating during the disruption thermal quench and volumetric heating of the component armour and structure due to localised impact of ...

1990-01-01

235

Stabilizing effect of the electron-beam self-fields on the phase-space trajectory in a self-amplified spontaneous emission free-electron laser operating in ultraviolet and x-ray spectral ranges  

International Nuclear Information System (INIS)

A detailed treatment is introduced to measure the dynamic stability of the relativistic electrons in a self-amplified spontaneous emission free-electron laser (FEL) system, which includes the numerical approach of the Kolmogorov entropy (entropy-like quantity), the general equations of motion for a charged particle and the method of monitoring the simulation accuracy. Numerical experiments reveal a new phenomenon that there exists the possibility of the transition from chaotic to non-chaotic phase-space trajectories of the strongly relativistic electrons due to the effect of their self-fields. The adiabatic magnetic field of a one-dimensional wiggler may have a slight influence on the electron transportation in the absence of the FEL fields, but substantially affects the dynamic stability of the electrons in the process of the FEL interaction. Moreover, the laser fields diminish the dynamic stability of the electrons as the FEL interaction ...

2004-02-28

236

Selected topics in particle accelerators: Proceedings of the CAP meetings. Volume 5  

Energy Technology Data Exchange (ETDEWEB)

This Report includes copies of transparencies and notes from the presentations made at the Center for Accelerator Physics at Brookhaven National Laboratory Editing and changes to the authors` contributions in this Report were made only to fulfill the publication requirements. This volume includes notes and transparencies on nine presentations: ``The Energy Exchange and Efficiency Consideration in Klystrons``, ``Some Properties of Microwave RF Sources for Future Colliders + Overview of Microwave Generation Activity at the University of Maryland``, ``Field Quality Improvements in Superconducting Magnets for RHIC``, ``Hadronic B-Physics``, ``Spiking Pulses from Free Electron Lasers: Observations and Computational Models``, ``Crystalline Beams in Circular Accelerators``, ``Accumulator Ring for AGS & Recent AGS Performance``, ``RHIC Project Machine Status``, and ``Gamma-Gamma Colliders.``

1995-10-01

237

Database for thermal and mechanical properties of REBaCuO bulks  

International Nuclear Information System (INIS)

The thermal properties (thermal conductivity, thermal diffusivity, thermoelectric power, thermal dilatation, etc.) and the mechanical properties (Young's modulus, strength, hardness, fracture toughness, etc.) have been measured at low temperatures (4-300K) and under a high magnetic field (0-10T) for about 50 REBaCuO bulks (RE=Y, Gd, Nd, Sm, Dy, etc.). We have constructed the database of these properties and opened it on the Web site (thermal properties: http://ikebehp.mat.iwate-u.ac.jp/database.html and mechanical properties: http://paris.mech.iwate-u.ac.jp/sc-bulk/database.html). The influence of the species of RE ions, the content, size and dispersion of the RE211 (or Nd422) phase and Ag particles and the defects distribution on these properties is characterized.

2005-10-01

238

Cancer-cell-specific cytotoxicity of non-oxidized iron elements in iron core-gold shell NPs  

British Library Electronic Table of Contents (United Kingdom)

Gold-coated iron nanoparticles (NPs) selectively and significantly (P <0.0001) inhibit proliferation of oral- and colorectal-cancer cells in vitro at doses as low as 5 mg/mL, but have little adverse effect on normal healthy control cells. The particle treatment caused delay in cell-cycle progression, especially in the S-phase. There was no significant difference in the NP uptake between cancer and control cells, and cytotoxicity resulted primarily from the iron core, before oxidation, rather than from the Fe ions released from the core. In contrast with magnetic NPs that usually serve as drug carriers, diagnostic probes or hyperthermia media, the iron, before oxidation, in the NPs selectively suppressed cancer cell growth and left healthy control cells unaffected in vitro and in vivo. This...

2011-01-01

239

Basic mechanisms of radiation effects in the natural space radiation environment  

Energy Technology Data Exchange (ETDEWEB)

Four general topics are covered in respect to the natural space radiation environment: (1) particles trapped by the earth`s magnetic field, (2) cosmic rays, (3) radiation environment inside a spacecraft, (4) laboratory radiation sources. The interaction of radiation with materials is described by ionization effects and displacement effects. Total-dose effects on MOS devices is discussed with respect to: measurement techniques, electron-hole yield, hole transport, oxide traps, interface traps, border traps, device properties, case studies and special concerns for commercial devices. Other device types considered for total-dose effects are SOI devices and nitrided oxide devices. Lastly, single event phenomena are discussed with respect to charge collection mechanisms and hard errors. (GHH)

1994-06-01

240

Paul Trap Simulator Experiment to Model Intense Beam Propagation in Alternating-gradient Transport Systems  

Energy Technology Data Exchange (ETDEWEB)

The results presented here demonstrate that the Paul Trap Simulator Experiment (PTSX) simulates the propagation of intense charged particle beams over distances of many kilometers through magnetic alternating-gradient (AG) transport systems by making use of the similarity between the transverse dynamics of particles in the two systems. Plasmas have been trapped that correspond to normalized intensity parameters s = wp2 (0)/2wq2 * 0.8, where wp(r) is the plasmas frequency and wq is the average transverse focusing frequency in the smooth-focusing approximation. The measured root-mean-squared (RMS) radius of the beam is consistent with a model, equally applicable to both PTSX and AG systems that balances the average inward confining force against the outward pressure-gradient and space-charge forces. The PTSX device confines one-component cesium ion plasmas for hundreds of milliseconds, which is equivalent to over 10 km of ...

2004-01-29

241

Construction and Calibration of the Laser Alignment System for the CMS Tracker  

CERN Document Server

The CMS detector (Compact Muon Solenoid) is under construction at one of the four proton-proton interaction points of the LHC (Large Hadron Collider) at CERN, the European Organization for Nuclear Research (Geneva, Switzerland). The inner tracking system of the CMS experiment consisting of silicon detectors will have a diameter of 2.4 m and a length of 5.4 m representing the largest silicon tracker ever. About 15000 silicon strip modules create an active silicon area of 200 m2 to detect charged particles from proton collisions. They are placed on a rigid carbon fibre structure, providing stability within the working conditions of a 4 T solenoid magnetic field at ?10oC. Knowledge of the position of the silicon detectors at the level of 100 ?m is needed for an efficient pattern recognition of charged particle tracks. Metrology methods are used to survey tracker subdetectors and the integrated Laser Alignment System (LAS) ...

2006-01-01

242

Application of realistic meson-exchange forces in the broken-pair model  

Energy Technology Data Exchange (ETDEWEB)

A G-matrix, derived from a meson-exchange potential in nuclear matter, is applied to finite, semi-magic nuclei. For the open shell the broken-pair model, which can accommodate many single-particle levels, is used. The excitations of the closed shell are treated as particle-hole states. Energy spectra and electromagnetic transition densities are calculated for /sup 88/Sr and /sup 58/Ni. The energies of the non-collective states are well described. Pairing correlations in the ground state have almost the correct strength in a multishell model space. To improve the energies of the collective 2/sup +/ and 3/sup -/ states the inclusion of core-polarisation effects in the force is required. Transition charge densities for collective states become strongly surface-peaked by core-polarisation effects, as is observed in experiments. The effects of pairing correlations and core polarisation on the magnetic form factor of the 3.486 ...

1985-03-11

243

Application of realistic meson-exchange forces in the broken-pair model  

International Nuclear Information System (INIS)

A G-matrix, derived from a meson-exchange potential in nuclear matter, is applied to finite, semi-magic nuclei. For the open shell the broken-pair model, which can accommodate many single-particle levels, is used. The excitations of the closed shell are treated as particle-hole states. Energy spectra and electromagnetic transition densities are calculated for "8"8Sr and "5"8Ni. The energies of the non-collective states are well described. Pairing correlations in the ground state have almost the correct strength in a multishell model space. To improve the energies of the collective 2"+ and 3"- states the inclusion of core-polarisation effects in the force is required. Transition charge densities for collective states become strongly surface-peaked by core-polarisation effects, as is observed in experiments. The effects of pairing correlations and core polarisation on the magnetic form factor of the 3.486 MeV 1"+ state in ...

244

Specification of the steel sheet for the 300 GeV magnet system  

CERN Document Server

Specification of the steel sheet for the 300 GeV magnet system

1971-01-01

245

Radial Halbach Magnetic Bearings  

Science.gov (United States)

Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly

2009-01-01

246

Magnetic phase transition in UPd_2Si_2  

International Nuclear Information System (INIS)

... fields magnetic moments neel temperature neutron diffraction order-disorder

247

Magnetic forming of resistive materials  

Science.gov (United States)

Necessary theoretical foundation is given for the treatment of magnetic stresses applied to

1969-01-01

248

Magnetic forming coil design and development summary report  

Science.gov (United States)

Magnetic forming coil design and development

1964-01-01

250

Large scale magnetic field measurements and mapping  

CERN Document Server

Large scale magnetic field measurements and mapping

1984-01-01

251

ELECTRICAL AND DIAGNOSTIC ASPECTS OF ELECTROHYDRAULIC AND MAGNETIC FORMING  

Science.gov (United States)

Discussion of an electrohydraulic and magnetic forming process

1963-01-01

253

Input deuteron states in Mo even isotopes  

International Nuclear Information System (INIS)

An attempt is taken to explain anomalies in "9"2Mo(d, n)"9"3Tc, "9"2Mo(d, #alpha#)"9"0Nb, "9"4Mo(d, n)"9"5Tc, "9"8Mo(d, n)"9"9Tc, "9"8Mo(d, p)"9"9Mo, "9"8Mo(d, #alpha#)"9"6Nb, "1"0"0Mo(d, p)"1"0"1Mo and "1"0"0Mo(d, n)"1"0"1Tc reactions with input states having a one-particle nature. Thin films saturated with molybdenum isotopes at the approximately 1 mgxcm"-"2 surface density are used as targets. The targets are irradiated by the extracted cyclotron beam. The deuteron energy is 5-12 MeV. The reaction cross sections are determined by the activation analysis method. Quasi-stationary levels of the nucleus-deuteron system are calculated. Weak anomalies revealing in a smooth (d, #alpha#) reaction cross section on sup(92, 98)Mo nuclei, which do not necessarily correlate with anomalies in the (d, n) and (d, p) channels, are observed. The ground states of the (d, #alpha#) reaction products "9"0Nb and "9"6Nb have (8"+) and (6"+) ...

254

Metal Nanoparticles Preparation In Supercritical Carbon Dioxide Solutions  

Energy Technology Data Exchange (ETDEWEB)

The novel optical, electronic, and/or magnetic properties of metal and semiconductor nanoparticles have resulted in extensive research on new methods for their preparation. An ideal preparation method would allow the particle size, size distribution, crystallinity, and particle shape to be easily controlled, and would be applicable to a wide variety of material systems. Numerous preparation methods have been reported, each with its inherent advantages and disadvantages; however, an ideal method has yet to emerge. The most widely applied methods for nanoparticle preparation include the sonochemical reduction of organometallic reagents,(1&2) the solvothermal method of Alivisatos,(3) reactions in microemulsions,(4-6) the polyol method (reduction by alcohols),(7-9) and the use of polymer and solgel materials as hosts.(10-13) In addition to these methods, there are a variety of methods that take advantage of the unique ...

2004-04-01

255

Lubricant wear particle analysis by filter patch extraction  

Energy Technology Data Exchange (ETDEWEB)

Lubricating Oil Analysis (LOA) has become an important part of a comprehensive Reliability Centered Maintenance (RCM) program. However, knowing the condition of the lubricant alone does not provide a complete description of equipment reliability. Condition monitoring for equipment can be accomplished through Wear Particle Analysis (WPA). This usually involves separating suspended materials and wear products from the lubricant by magnetic (ferrographic) means. This paper will present a simple, low-cost, alternate method of particle acquisition called Filter Patch Extraction (FPE). This method removes solids, regardless of their composition, from the lubricant by vacuum filtration and deposits them onto a filter for microscopic examination similar to that of analytical ferrography. A large filter pore size retains suspended materials and permits rapid filtration of large volumes of lubricant thereby increasing the accuracy of ...

1996-07-01

256

European Space Agency announces contest to "Name the Cluster Quartet"  

Science.gov (United States)

1. Contest rules The European Space Agency (ESA) is launching a public competition to find the most suitable names for its four Cluster II space weather satellites. The quartet, which are currently known as flight models 5, 6, 7 and 8, are scheduled for launch from Baikonur Space Centre in Kazakhstan in June and July 2000. Professor Roger Bonnet, ESA Director of Science Programme, announced the competition for the first time to the European Delegations on the occasion of the Science Programme Committee (SPC) meeting held in Paris on 21-22 February 2000. The competition is open to people of all the ESA member states (*). Each entry should include a set of FOUR names (places, people, or things from history, mythology, or fiction, but NOT living persons). Contestants should also describe in a few sentences why their chosen names would be appropriate for the four Cluster II satellites. The winners will be those which are considered most suitable and relevant for the Cluster II mission. ...

2000-02-01

258
260

Computational Challenges in miRNA Target Predictions: To Be or Not to Be a True Target?  

UK PubMed Central (United Kingdom)

All microRNA (miRNA) target—finder algorithms return lists of candidate target genes. How valid is that output in a biological setting? Transcriptome analysis has proven to be a useful approach...Full Text Available

2009-01-01

261
262

Correlation between particle size, in vivo particle persistence, and lung injury.  

UK PubMed Central (United Kingdom)

Dosimetry parameters such as deposition, clearance, retention, and translocation and dissolution of inhaled particles in and to different lung compartments may be important for the persistence of particles...Full Text Available

1994-10-01

263

Comparison and Physical Interpretation of MCNP and TART Neutron and Gamma Monte Carlo Shielding Calculations for a Heavy-Ion ICF System  

Energy Technology Data Exchange (ETDEWEB)

For heavy-ion beam driven inertial fusion ''liquid-protected'' reactor designs such as HYLIFE-II, a mixture of molten salts made of F{sup 10}, Li{sup -6}, Li{sup 7} and Be{sup 9} (called flibe) allows small chambers and final-focus magnets closer to the target with superconducting coils suffering higher radiation damage, though they can stand only a certain amount of energy deposited before quenching. This work has been primarily focusing on verifying that total energy deposited by fusion neutrons and induced gamma rays remain under such limit values and the final purpose is the optimization of the shielding of the magnetic lens system from the points of view of the geometrical configuration and of the physical nature of the materials adopted. The system is analyzed in terms of six geometrical models going from simplified up to much more realistic representations of a system of 192 beam ...

2002-07-01

264

Cellular dosimetry: Absorbed fractions for monoenergetic electron and alpha particle sources and S-values for radionuclides uniformly distributed in different cell compartments  

Energy Technology Data Exchange (ETDEWEB)

The importance of cellular dosimetry in both diagnostic and therapeutic nuclear medicine is becoming increasingly recognized. Experimental range-energy relations for electrons and alpha particles, along with derived geometric reduction factors, are used to calculate cellular absorbed fractions for these radiations. The resulting absorbed fractions are employed to calculate cellular S-values for several radionuclides. Cellular absorbed fractions for monoenergetic electron sources with energies ranging from 0.1 keV to 1 MeV, distributed uniformly in the source region, are calculated for several target {l_arrow} source combinations including cell{l_arrow}cell, cell{l_arrow}cell surface, nucleus{l_arrow}nucleus, nucleus {l_arrow}cytoplasm and nucleus {l_arrow}cell surface. Similar data are also provided for monoenergetic alpha particle sources with energies ranging from 3 to 10 MeV. S-values are also conveniently tabulated for ...

1994-02-01

265

Basics of Ion Scattering in Nanoscale Materials  

Science.gov (United States)

Energetic ions interact with materials by collisions with the nuclei and electrons of the atoms that make up the material. In these collisions energy and momentum is transferred from the projectile particle which is a moving atom or ion, to the target particles (atomic nucleus or electron). Each collision leads to a slowing down of the moving projectile and also a deflection of the trajectory which gives rise to the term scattering which is often used synonymously to describe the energy transfer process. In this chapter, we introduce from an experimental viewpoint the underlying theory for interaction of ions for analysis and modification of nanometer scale materials. A more detailed theoretical overview of the topic can be found in the recent monographs by Sigmund. Detailed derivations of the formulae introduced will not be given here but can be found in standard texts that are indicated by references. The treatment here ...

2010-01-01

266

Revisit to the helicity and the generalized self-organization theory  

Energy Technology Data Exchange (ETDEWEB)

It is clarified that the so-caned 'helicity conservation law' is never the conservation equation of the helicity K itself', but is merely 'the time change rate equation of K', which is passively and resultantly determined by the mutually independent volume and surface integral terms. It is shown that since the total helicity K can never be conserved in the real experimental systems, the conjecture of the total helicity invariance is not physically available to real magnetized plasmas in an exact sense. The well-known relaxation theory by Dr. J. B. Taylor is clarified to be neither the variational principle nor the energy principle, but be merely a mathematical calculation, using the variational calculus in order to find the minimum magnetic energy solution from the set of solutions having the same value of K. With the use of auto-correlations for physical quantities, it is presented that a novel ...

2000-09-01

267

Separation Science and Technology. Semiannual progress report, April 1993--September 1993  

Energy Technology Data Exchange (ETDEWEB)

This document reports on the work done by the Separations Science and Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April-September 1993. This effort is mainly concerned with developing the TRUEX process for removing and concentrating actinides from acidic waste streams contaminated with transuranic (TRU) elements. The objectives of TRUEX processing are to recover valuable TRU elements and to lower disposal costs for the nonTRU waste product of the process. Other projects are underway with the objective of developing (1) evaporation technology for concentrating radioactive waste and product streams such as those generated by the TRUEX process, (2) treatment schemes for liquid wastes stored or being generated at Argonne, (3) a process based on sorbing modified TRUEX solvent on magnetic beads to be used for separation of contaminants from radioactive and hazardous waste streams, and (4) a process that uses ...

1996-01-01

268

New real-time MR image-guided surgical robotic system for minimally invasive precision surgery  

Energy Technology Data Exchange (ETDEWEB)

To investigate the usefulness of a newly developed magnetic resonance (MR) image-guided surgical robotic system for minimally invasive laparoscopic surgery. The system consists of MR image guidance [interactive scan control (ISC) imaging, three-dimensional (3-D) navigation, and preoperative planning], an MR-compatible operating table, and an MR-compatible master-slave surgical manipulator that can enter the MR gantry. Using this system, we performed in vivo experiments with MR image-guided laparoscopic puncture on three pigs. We used a mimic tumor made of agarose gel and with a diameter of approximately 2 cm. All procedures were successfully performed. The operator only advanced the probe along the guidance device of the manipulator, which was adjusted on the basis of the preoperative plan, and punctured the target while maintaining the operative field using robotic forceps. The position of the probe was monitored continuously with 3-D ...

2008-04-15

269

Neutron magnetic form factor G{sub M}{sup n}(Q{sup 2}) from quasielastic inclusive scattering data on D and {sup 4}He  

Science.gov (United States)

We analyze cross sections for quasielastic inclusive scattering of electrons on nuclei and show that the observed isolated peaks for relatively low Q{sup 2} are unique for the lightest targets. Focusing, in particular, on D and {sup 4}He, we investigate in two ways to what measure the above peaks can be allocated to nucleon-elastic processes. We first compute approximate upper limits for the nucleon-inelastic background in the quasielastic region due to inclusive {delta} excitation, and find those to be small. Far more precise is a semiphenomenological approach, where the dominance of nucleon-elastic processes is translated into a set of stringent requirements. We show that those are very well fulfilled for recent D data, and to a somewhat lesser extent for older D and {sup 4}He data. With knowledge of G{sub E,M}{sup p} and information on G{sub E}{sup n}, we then extract G{sub M}{sup n} and find agreement with values obtained by alternative methods. We discuss the ...

2004-07-01

270

Neutron magnetic form factor G_M"n(Q"2) from quasielastic inclusive scattering data on D and "4He  

International Nuclear Information System (INIS)

We analyze cross sections for quasielastic inclusive scattering of electrons on nuclei and show that the observed isolated peaks for relatively low Q"2 are unique for the lightest targets. Focusing, in particular, on D and "4He, we investigate in two ways to what measure the above peaks can be allocated to nucleon-elastic processes. We first compute approximate upper limits for the nucleon-inelastic background in the quasielastic region due to inclusive #DELTA# excitation, and find those to be small. Far more precise is a semiphenomenological approach, where the dominance of nucleon-elastic processes is translated into a set of stringent requirements. We show that those are very well fulfilled for recent D data, and to a somewhat lesser extent for older D and "4He data. With knowledge of G_E_,_M"p and information on G_E"n, we then extract G_M"n and find agreement with values obtained by alternative methods. We discuss the sensitivity of the extraction method and ...

2004-07-01

271

Natural killer cell activity influences outcome after T cell depleted stem cell transplantation from matched unrelated and haploidentical donors  

British Library Electronic Table of Contents (United Kingdom)

Lytic activity and recovery of natural killer (NK) cells was monitored in pediatric patients with leukemias (ALL, AML, CML, JMML) and myelodysplastic syndromes after transplantation of T cell depleted stem cells from matched unrelated (n = 18) and mismatched related (haploidentical, n = 29) donors. CD34 + selection with magnetic microbeads resulted in 8 x 10^3/kg residual T cells. No post-transplant immune suppression was given. NK cells recovered rapidly after transplantation (300 CD56+/@mL at day 30, median), whereas T cell recovery was delayed (median: 12 CD3+/@mL at day 90). NK activity was measured as specific lysis of K 562 targets several times (mean: 3 assays per patient). Four temporal patterns of lytic activity could be differentiated: consistently low, consistently high, decreas...

2011-01-01

272

Large area electron beam pumped krypton fluoride laser amplifier  

International Nuclear Information System (INIS)

Nike is a recently completed multi-kilojoule krypton fluoride (KrF) laser that has been built to study the physics of direct drive inertial confinement fusion. This paper describes in detail both the pulsed power and optical performance of the largest amplifier in the Nike laser, the 60 cm amplifier. This is a double pass, double sided, electron beam-pumped system that amplifies the laser beam from an input of 50 J to an output of up to 5 kJ. It has an optical aperture of 60 cm x 60 cm and a gain length of 200 cm. The two electron beams are 60 cm high x 200 cm wide, have a voltage of 640 kV, a current of 540 kA, and a flat top power pulse duration of 250 ns. A 2 kG magnetic field is used to guide the beams and prevent self-pinching. Each electron beam is produced by its own Marx/pulse forming line system. The amplifier has been fully integrated into the Nike system and is used on a daily basis for laser-target experiments. copyright 1997 ...

273

Consideration of some fundamental erosion processes encountered in hypervelocity electromagnetic propulsion  

Energy Technology Data Exchange (ETDEWEB)

Experimental and theoretical research has been conducted jointly at the Livermore and Los Alamos National laboratories on dc electromagnetic railgun Lorentz accelerators. Pellets weighing a few grams to tens of grams have been launched at velocities up to better than 11 km/s. The research is addressed to attaining repeated launches of samples at hypervelocity in target impact experiments. In these experiments, shock-induced pressures in the tens of megabars range are obtained for high pressure equation-of-state research. Primary energy sources of the order of several hundred kJ to a MJ and induction currents of the order of 1 or more MA are necessary for these launches. Erosion and deformation of the conductor rails and the accelerated sample material are continuing problems. The heating, stress, and erosion resulting from simultaneous imposition of rail induction current, dense plasma (armature) interaction, current distribution, magnetic ...

1982-09-30

274

Stability and disturbance of large dc superconducting magnets  

Energy Technology Data Exchange (ETDEWEB)

This paper addresses the stability aspects of several successful dc superconducting magnets such as large bubble chamber magnets, and magnets for the Mirror Fusion Test Facility and MHD Research Facility. Specifically, it will cover Argonne National Laboratory 12-Foot Bubble Chamber magnets, the 15-foot Bubble Chamber magnets at Fermi National Laboratory, the MFTF-B Magnet System at Lawrence Livermore National Laboratory, the U-25B Bypass MHD Magnet, and the CFFF Superconducting MHD magnet built by Argonne National Laboratory. All of these magnets are cooled in pool-boiling mode. Magnet design is briefly reviewed. Discussed in detail are the adopted stability critera, analyses of stability and disturbance, stability simulation, and the final results of magnet ...

1981-11-11

276

Magnetic braking of the rotation of molecular cloud cores  

International Nuclear Information System (INIS)

We investigate the magnetic braking of the core of an axisymmetric cloud whose rotation axis is parallel to the mean direction of the magnetic field. (author).

277

LHC magnet alignment  

CERN Document Server

Checks are performed on the alignment of the magnets in the LHC tunnel. It is vital that each magnet is placed exactly where it has been designed so that the path of the beam is precisely controlled.

2007-01-01

278

Density separation of materials by using magnetic fluids  

Energy Technology Data Exchange (ETDEWEB)

The magnetic fluid is a colloidal suspension of magnetite in kerosene, prepared by a low-cost process. Separation is accomplished in an open trough filled with magnetic fluid. A magnetic field is established in the fluid, by energizing an electromagnet having poles on each side of the trough. Due to the design of the magnet poles and air gaps, the magnetic field is strongest at the bottom, about 10,000 oersteds, and uniformly decreases in strength to about 2000 oersteds at the top of the fluid. Therefore, the magnetic field gradient increases with depth. The magnetic force attracts the entire separation medium (magnetic fluid) creating a reaction force of equal magnitude and acting in the opposite direction. This reaction created within a magnetic fluid/magnetic field combination ...

1980-03-01

279

Theory of mirror machines at high beta  

Science.gov (United States)

The kinetic and guiding center fluid theories of high-..beta.. plasma containment in mirror machines have been developed in a number of self-consistent models. The geometrical effects of magnetic field and ambipolar potential variation have been incorporated in a bounce-averaged Fokker-Planck code which shows that the square-well model somewhat overestimates the n tau and ..beta.. achievable in a mirror field. Simple analytic approximations to the resulting pressure profiles have been incorporated in three-dimensional fluid-equilibrium codes which show the effect of coil geometry on the maximum ..beta... Strongly curved vacuum fields allow higher ..beta.., but short plasmas in weakly curved fields tend to reverse the curvature locally before the mirror-mode limit is reached. Adiabaticity of particle orbits is described in terms of general formulas, applicable in high-..beta.. plasma equilibria, and is shown to break down close to the ...

1976-08-06

280

Precious Metals in Municipal Solid Waste Incineration Bottom Ash  

Energy Technology Data Exchange (ETDEWEB)

Municipal solid waste incineration (MSWI) bottom ash contains economically significant levels of silver and gold. Bottom ashes from incinerators at Amsterdam and Ludwigshafen were sampled, processed, and analyzed to determine the composition, size, and mass distribution of the precious metals. In order to establish accurate statistics of the gold particles, a sample of heavy non-ferrous metals produced from 15 tons of wet processed Amsterdam ash was analyzed by a new technology called magnetic density separation (MDS). Amsterdam's bottom ash contains approximately 10 ppm of silver and 0.4 ppm of gold, which was found in particulate form in all size fractions below 20 mm. The sample from Ludwigshafen was too small to give accurate values on the gold content, but the silver content was found to be identical to the value measured for the Amsterdam ash. Precious metal value in particles smaller than 2 mm seems to ...

2009-04-15

281

Methods and results for calibration and track separation of a GEM based TPC using an UV-laser  

Energy Technology Data Exchange (ETDEWEB)

In the last 30 years high energy physics could write an impressive story of success. Since the introduction of the Standard Model (SM), it has met every experimental test. However the final confirmation has to prove the mechanism of electroweak symmetry breaking, which could not be confirmed yet. The most favored theory, which includes the introduction of a Higgs field, could not be verified experimentally. Furthermore there is clear evidence, that the SM is only a low energy description of nature and its principles, as the SM describes only 4 % of the known matter in the universe. There are two different approaches in accelerator driven high energy physics to clarify the open questions. The Large Hadron Collider (LHC) have a good opportunity to measure some of the missing pieces with its high center of mass energy. The International Linear Collider (ILC) will then measure their parameters with high precision. To guarantee this high precision the detectors have to be able to identify ...

2008-12-15

282

Extension of improved particle and energy confinement regime in the core of LHD plasma  

International Nuclear Information System (INIS)

Recent two major topics of Large Helical Device (LHD) towards fusion relevant conditions, high-density operation and high-ion-temperature operation, are reported. Super dense core plasma was obtained by the combination of repetitive hydrogen ice pellet injection and high power neutral beam injection (NBI) heating. A very peaked density profile with the highest central density of 1.1x1021 m-3 was produced showing that the particle transport was suppressed very well in the plasma core. The spatial density varies as the position of magnetic axis (Rax), and the steepest profile is obtained at Rax=3.95 m. The highest central ion temperature of 5.6 keV was obtained in hydrogen plasma at electron density of 1.6 x 1019 m-3 by NBI, where a peaked ion-temperature profile with internal ion energy transport barrier was observed. The profile of electron temperature did not change much and was broad even when the ion temperature had a peaked profile. The ...

2009-06-01

283

Experimental estimation of the hot spot size in Nb-based Josephson tunnel junctions using Abrikosov vortices  

Energy Technology Data Exchange (ETDEWEB)

We report on a new experimental approach to the size estimation of the hot spot induced by ionizing particles in a Josephson tunnel junction. Here, in contrast to the case of a superconducting strip, it is possible to investigate the hot spot dynamics in absence of effects due to the heating induced by the bias current. The reported experiment is based on the motion of Abrikosov vortices, trapped in the thin films constituting the junction electrodes, under 5.6 MeV {alpha}-particle irradiation. The fast time evolution of a hot spot, combined with the presence of Abrikosov vortices, produces a change of the static magnetic field in the junction area and thus a change of the critical current value, I{sub c}. Measurements of I{sub c} during the {alpha}-particle irradiation and in presence of trapped Abrikosov vortices allow to determine the rate of appearance of those I{sub c} changes. The behavior of the ...

1997-11-01

284

Space Radiation Detector with Spherical Geometry  

Science.gov (United States)

A particle detector is provided, the particle detector including a spherical Cherenkov detector, and

2011-01-01

285

Flawless start for world's mightiest particle collider  

CERN Document Server

Flawless start for world's mightiest particle collider

2008-01-01

287

Neutron observables from inclusive lepton scattering on nuclei  

Science.gov (United States)

We analyze new data from Thomas Jefferson National Accelerator Facility (JLab) for inclusive electron scattering on various targets. Computed and measured total inclusive cross sections in the range 0.3 < or approx. x < or approx. 0.95 show reasonable agreement on a logarithmic scale for all targets. However, closer inspection of the quasielastic components reveals serious discrepancies. European Muon Collaboration (EMC) ratios with conceivably smaller systematic errors fare the same. As a consequence, the new data do not enable the extraction of the magnetic form factor G{sub M}{sup n} and the structure function F{sub 2}{sup n} of the neutron, although the application of exactly the same analysis to older data had been successful. We incorporate in the above analysis older CLAS Collaboration data on F{sub 2}{sup 2H}. Removal of some scattered points from those makes it appear possible to obtain the desired neutron ...

2010-07-15

288

Transport in a toroidally confined pure electron plasma  

International Nuclear Information System (INIS)

O close-quote Neil and Smith [T.M. O close-quote Neil and R.A. Smith, Phys. Plasmas 1, 8 (1994)] have argued that a pure electron plasma can be confined stably in a toroidal magnetic field configuration. This paper shows that the toroidal curvature of the magnetic field of necessity causes slow cross-field transport. The transport mechanism is similar to magnetic pumping and may be understood by considering a single flux tube of plasma. As the flux tube of plasma undergoes poloidal ExB drift rotation about the center of the plasma, the length of the flux tube and the magnetic field strength within the flux tube oscillate, and this produces corresponding oscillations in T_p_a_r_a_l_l_e_l and T_p_e_r_p_e_n_d_i_c_u_l_a_r. The collisional relaxation of T_p_a_r_a_l_l_e_l toward T_p_e_r_p_e_n_d_i_c_u_l_a_r produces a slow dissipation of electrostatic energy into heat and a consequent expansion (cross-field ...

289

Physical and optical properties of rare earth cobalt magnets  

Energy Technology Data Exchange (ETDEWEB)

Rare Earth Cobalt (REC) permanent magnets have unique properties that permit solutions to some optical tasks that cannot be accomplished with conventional magnets. A review of design and of performance characteristics of these magnets includes an analytical description of the three dimensional fringe fields of REC quadrupoles.

1980-08-01

295

METHOD OF FORMING THIN MAGNETIC FILM  

J-STORE (Japan)

Full Text Available

2007-10-04

301

{beta}-decay half-lives of very neutron-rich isotopes of elements from Ti to Ni  

Energy Technology Data Exchange (ETDEWEB)

The unknown {beta}-decay half-lives of 22 isotopes far off stability (5 < T{sub Z} < 10) in the region from Ti to Ni were measured at GSI, Darmstadt. The nuclei were produced in a fragmentation reaction of 500 A.MeV {sup 86}Kr-projectile impinging on a thick Be target. The isotopes of interest were separated and identified with the fragment separator, FRS, by a combination of B{rho},Z, and ToF techniques. An additional range separation was performed by a selective implantation into granular detectors. The spatial and time correlations of the implant with the consecutively detected {beta}-particles were used to determine the unknown half-lives. For nuclei far off stability, {beta}-decay chains were measured and analyzed as well, leading to an even more reliable evaluation of the lifetimes. The large discrepancies found between the measured and the theoretical values emphasize that most recent theoretical work is not an improvement over ...

1998-03-01

302

T=(5/2) "2"7Na from "1"4C+"1"4C, and the N=16 shell gap  

International Nuclear Information System (INIS)

For the first time a comprehensive level and decay scheme has been obtained for a T=(5/2) nucleus in the s-d shell ("2"7Na) by using a radioactive beam and target. Particle-#gamma# and p-#gamma#-#gamma# coincidences were measured following the "1"4C("1"4C,p#gamma#)"2"7Na reaction at E_l_a_b=22 MeV. The results do not support an inversion of the 2s_1_/_2 and 1d_5_/_2 orbitals, as previously proposed for T_z#>=#3, but they do suggest an increased N=16 gap between the 2s_1_/_2 and 1d_3_/_2 orbitals due to the neutron excess. A consistent interpretation of the level scheme in terms of the s-d shell model using the USD Hamiltonian is possible below 4 MeV, but differences increase at higher excitation energies. Another interpretation is that the influences of both the p_1_/_2 and f_7_/_2 intruder orbitals increase simultaneously with increasing T, an effect not included in the USD Hamiltonian.

2002-05-01

303

Shock characterization of TOAD pins  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this program was to characterize Time Of Arrival Detectors (TOAD) pins response to shock loading with respect to risetime, amplitude, repeatability and consistency. TOAD pins were subjected to impacts of 35 to 420 kilobars amplitude and approximately 1 ms pulse width to investigate the timing spread of four pins and the voltage output profile of the individual pins. Sets of pins were also aged at 45{degrees}, 60{degrees}, and 80{degrees}C for approximately nine weeks before shock testing at 315 kilobars impact stress. Four sets of pins were heated to 50.2{degrees}C (125{degrees}F) for approximately two hours and then impacted at either 50 or 315 kilobars. Also, four sets of pins were aged at 60{degrees}C for nine weeks and then heated to 50.2{degrees}C before shock testing at 50 and 315 kilobars impact stress, respectively. Particle velocity measurements at the contact point between the stainless steel targets and TOAD pins were ...

1995-08-01

304

Progress at LAMPF, 1992--1993  

Energy Technology Data Exchange (ETDEWEB)

This Progress Report describes the operation of the Los Alamos Meson Physics Facility (LAMPF) and the research programs carried out there for the years 1992 and 1993. The accelerator operated for over 100 days in 1992, providing beams of H{sup +}, H{sup {minus}}, and polarized H{sup {minus}} for a rich and varied research program in nuclear physics. The accelerator had only fair beam availability in 1992 (for example, the average H{sup +} beam availability was 72%), caused largely by problems in the 201-MHz rf system. A major effort was expended to address these problems before the 1993 run. These efforts were rewarded by good beam availability in 1993 and few problems with the 201-MHz system. LAMPF operated remarkably smoothly during 1993, in the midst of a period of great uncertainty in the future of the facility and the downsizing of MP Division, which led to the loss of a large number of key people to positions elsewhere in the Laboratory. The H{sup +} intensity had to be held to ...

1994-07-25

305

OPTIMIZATION OF COMMINUTION CIRCUIT THROUGHPUT AND PRODUCT SIZE DISTRIBUTION BY SIMULATION AND CONTROL  

Energy Technology Data Exchange (ETDEWEB)

The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This is being accomplished by mathematical modeling of the grinding circuits to determine how to correct this problem. The approaches taken included (1) Modeling of the circuit to determine process bottlenecks that restrict flowrates in one area while forcing other parts of the circuit to overgrind the material; (2) Modeling of hydrocyclones to determine the mechanisms responsible for retaining fine, ...

2004-10-01

306

Coulomb and photo cross sections for nucleon emission by relativistic heavy ions and application to "4"0Ar on "8"9Y  

International Nuclear Information System (INIS)

The Coulomg-induced emission of nucleons by relativistic heavy ions is studied with respect to partial cross sections related to the various multipole orders of the electromagnetic field. Since the partial Coulomb cross sections can be factorized into the numbers of virtual photons and the photo cross sections, we first calculate the photo cross sections using the oscillator shell model and 1-particle-1-hole configurations. Then the Coulomb cross sections are obtained by folding the photo cross sections with the numbers of virtual photons. We apply the calculations to the Coulomb scattering of "4"0Ar ions on "8"9Y targets, where experiments at E_l_a_b=1.8 GeV/nucleon were carried out by Mercier et al. The contributions of the various multipole orders are discussed as functions of the projectile energy and the energy range of the emitted nucleons. Also methods for the separation of the most contributing multipole orders are developed. (orig.).

307

Chromosome aberrations in human lymphocytes from the plateau region of the Bragg curve for a carbon-ion beam  

Energy Technology Data Exchange (ETDEWEB)

Radiotherapy with high-energy carbon ion beams can be more advantageous compared to photons because of better physical dose distribution and higher biological efficiency in tumour cell sterilization. Despite enhanced normal tissue sparing, damage incurred by normal cells at the beam entrance is unavoidable and may affect the progeny of surviving cells in the form of inheritable cytogenetic alterations. Furthermore, the quality of the beam along the Bragg curve is modified by nuclear fragmentation of projectile and target nuclei in the body. We present an experimental approach based on the use of a polymethylmethacrylate (PMMA) phantom that allows the simultaneous exposure to a particle beam of several biological samples positioned at various depths along the beam path. The device was used to measure the biological effectiveness of a 60 MeV/amu carbon-ion beam at inducing chromosomal aberrations in G{sub 0}-human peripheral blood lymphocytes. ...

2007-06-15

308

Bimodality in binary Au + Au collisions from 60 to 100 MeV/u  

Energy Technology Data Exchange (ETDEWEB)

The deexcitation of quasi-projectiles (QP) released in binary Au on Au collisions as been studied from 60 to 100 MeV/u. Bimodality between two different decay patterns has been observed for intermediate violence collisions. The main experimental result is that the system jumps from one mode to the other on a narrow range of energy deposit and/or impact parameter. The sorting of the events (according to the violence of the collision) has been provided by the perpendicular energy of the light charged particles emitted on the quasi-target side. Such a sorting prevents spurious autocorrelation effects between the sorting variable and the observed mechanism. The two modes of the QP decay correspond on the one side to residue or fission fragments production, and on the other side to the multifragmentation channel. A detailed study has been performed in order to try to establish the origin of the observed bimodality in disentangling dynamical or ...

2003-03-01

309

Actinides produced by /sup 12/C + /sup 242/Pu and /sup 16/O + /sup 238/U reactions  

Energy Technology Data Exchange (ETDEWEB)

The cross sections for /sup 250/Fm, /sup 244-246/Cf, /sup 242-244/Cm, and /sup 242/Am/sup g-italic/ produced by the /sup 12/C+ /sup 242/Pu and the /sup 16/O+ /sup 238/U reactions leading to the same compound nucleus of /sup 254/Fm have been measured by using radiochemical methods. The excitation functions show that the difference between the /sup 12/C+ /sup 242/Pu and the /sup 16/O+ /sup 238/U reactions can be attributed mainly to the Coulomb barriers. Our results were compared with others reported previously for /sup 22/Ne+ /sup 232/Th, /sup 12/C+ /sup 238/U, /sup 12/C+ /sup 240,241/Pu, /sup 13/C+ /sup 241/Pu, /sup 16/O+ /sup 233/U, and /sup 16/O+ /sup 242/Pu reaction systems, and support a mechanism involving transfer of ..cap alpha..-particle clusters (C,Be,He) from projectile to target for the production of Cf and Cm isotopes.

1986-09-01

310

Actinides produced by /sup 12/C + /sup 242/Pu and /sup 16/O + /sup 238/U reactions  

International Nuclear Information System (INIS)

The cross sections for /sup 250/Fm, /sup 244-246/Cf, /sup 242-244/Cm, and /sup 242/Am/sup g/ produced by the /sup 12/C+ /sup 242/Pu and the /sup 16/O+ /sup 238/U reactions leading to the same compound nucleus of /sup 254/Fm have been measured by using radiochemical methods. The excitation functions show that the difference between the /sup 12/C+ /sup 242/Pu and the /sup 16/O+ /sup 238/U reactions can be attributed mainly to the Coulomb barriers. Our results were compared with others reported previously for /sup 22/Ne+ /sup 232/Th, /sup 12/C+ /sup 238/U, /sup 12/C+ /sup 240,241/Pu, /sup 13/C+ /sup 241/Pu, /sup 16/O+ /sup 233/U, and /sup 16/O+ /sup 242/Pu reaction systems, and support a mechanism involving transfer of #alpha#-particle clusters (C,Be,He) from projectile to target for the production of Cf and Cm isotopes.

311

A critical survey of experimental cross section data, comparison with nuclear model calculations and estimation of production yields of "7"7Br and "7"7Kr in no-carrier-added form via various nuclear processes  

International Nuclear Information System (INIS)

Experimentally investigated nuclear reactions for production of no-carrier-added "7"7Br and "7"7Kr were critically surveyed. The survey covered nine reactions for the formation of "7"7Br and six reactions for "7"7Kr. Both radionuclides are simultaneously produced in many of the studied nuclear processes. The experimental data were compared with the results of nuclear model calculations based on the computer code ALICE-IPPE and the third version of TALYS-based Evaluated Nuclear Data Library, TENDL-2010. Good agreement was found over extended energy regions for the p-, "3He- and #alpha#-particle induced reactions on several target materials. In case of d-induced reactions, however, considerable discrepancies were noted between the experimental and theoretical data. The concordant sets of experimental cross section data for each reaction were fitted by a polynomial function to obtain a trend curve. From the thus obtained trend curves the yields of ...

2011-05-15

312

#beta#-decay half-lives of very neutron-rich isotopes of elements from Ti to Ni  

International Nuclear Information System (INIS)

The unknown #beta#-decay half-lives of 22 isotopes far off stability (5 < T_Z < 10) in the region from Ti to Ni were measured at GSI, Darmstadt. The nuclei were produced in a fragmentation reaction of 500 A.MeV "8"6Kr-projectile impinging on a thick Be target. The isotopes of interest were separated and identified with the fragment separator, FRS, by a combination of B#rho#,Z, and ToF techniques. An additional range separation was performed by a selective implantation into granular detectors. The spatial and time correlations of the implant with the consecutively detected #beta#-particles were used to determine the unknown half-lives. For nuclei far off stability, #beta#-decay chains were measured and analyzed as well, leading to an even more reliable evaluation of the lifetimes. The large discrepancies found between the measured and the theoretical values emphasize that most recent theoretical work is not an improvement over calculations ...

313

NASA TECH BRIEF  

Science.gov (United States)

Magnetic Forming Studies. The use of transient high magnetic-field devices has made possible the generation of very large accurately ...

315

Magnetic properties of single crystalline RE_2PdSi_3 intermetallic compounds  

International Nuclear Information System (INIS)

... susceptibility magnetization magnetoresistance monocrystals order-disorder

316

Finite Element Analysis of Magnetoelastic Plate Problems.  

Science.gov (United States)

... in the design of such devices as fusion reactors, magnetohydrodynamic generators, magnetically levitated vehicles, magnetic forming devices, and ...

1981-08-01

317

Design of a kW, DC Magnetically Contained Electrothermal ...  

Science.gov (United States)

... magnetic containment field lines which is zero on the center line of the toroidal containment tube and increases in magnitude with ...

1988-07-01

318

An investigation of the decoupling effects in a magnetic forming beryllium coil assembly.  

Science.gov (United States)

Decoupling force exerted by magnetic forming Be coil assembly on metallic plate during forming

1968-01-01

320

Progress of magnetic-suspension systems and magnetic bearings in the USSR  

International Nuclear Information System (INIS)

This paper traces the development and progress of magnetic suspension systems and magnetic bearings in the USSR. The paper describes magnetic bearings for turbomachines, magnetic suspension systems for vibration isolation, some special measuring devices, wind tunnels, and other applications. The design, principles of operation, and dynamic characteristics of the system are presented.

1992-05-01

321

International Symposium on Magnetic Suspension Technology. Part 2  

International Nuclear Information System (INIS)

In order to examine the state of technology of all areas of magnetic suspension and to review related recent developments in sensors and controls approaches, superconducting magnet technology, and design/implementation practices, a symposium was held. The proceedings are presented. The sessions covered the areas of bearings, sensors and controls, microgravity and vibration isolation, superconductivity, manufacturing applications, wind tunnel magnetic suspension systems, magnetically levitated trains (MAGLEV), space applications, and large gap magnetic suspension systems.

1991-08-19

322

Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1995--31 August 1996  

Energy Technology Data Exchange (ETDEWEB)

The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers parts of the second and third year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas: precision test of parity-invariance violation in resonance neutron scattering at LANSCE/LANL; parity violation measurements using charged-particle resonances in A = 20--40 targets and the A = 4 system at TUNL; chaotic behavior in the nuclei {sup 30}P and {sup 34}Cl from studies of eigenvalue fluctuations in nuclear level schemes; search for anomalies in the level density (pairing phase transition) in 1f-2p shell nuclei using GEANIE at LANSCE/LANL; parity-conserving time-reversal noninvariance tests using {sup 166}Ho resonances at ...

1996-09-01

323

Pre-oxidized and nitrided stainless steel alloy foil for proton exchange membrane fuel cell bipolar plates: Part 1. Corrosion, interfacial contact resistance, and surface structure  

Energy Technology Data Exchange (ETDEWEB)

Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2 x the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride ...

2010-09-01

324

Optimizing the radiosensitive liquid-core microcapsules for the targeting of chemotherapeutic agents  

Energy Technology Data Exchange (ETDEWEB)

Microcapsules consisting of alginate and hyaluronic acid that can be decomposed by radiation are currently under development. In this study, the composition of the microcapsule material was optimized by changing the amounts of alginate and hyaluronic acid. Solutions of 0.025%, 0.05%, 0.1%, 0.2%, or 0.4% (wt./vol.) hyaluronic acid were mixed into a 0.2% alginate solution. To these mixtures, carboplatin (0.2 mmol) was added and the resulting material was used for the capsule preparation. The capsules were prepared by spraying the material into a CaCl{sub 2} solution (0.34 mol/l) using a microatomizer. These capsules were irradiated by a single dose of 2, 5, or 10 Gy {sup 60}Co {gamma}-ray radiation. Immediately after irradiation, the releasing of core content of microcapsule was determined, using a micro particle induced X-ray emission (PIXE) camera. The average diameter of the microcapsules was 22.3 {+-} 3.3 {mu}m, and that of the liquid core was 10.2 {+-} 4.3 ...

2007-07-15

325

New oil exploration play in Florida: The upper Fredericksberg Dollar Bay Formation  

Energy Technology Data Exchange (ETDEWEB)

The Fredericksberg of South Florida may have a great oil potential that has been overlooked as a primary target in past decades. Previous exploration in the area has targeted the Lower Cretaceous oil-producing Sunniland Formation lower in the stratigraphic section. The Fredericksberg Dollar Bay Formation has hydrocarbon shows in many wells occurring in limestone biohermal deposits as well as in an upper dolomitic section. The Dollar Bay Formation is part of the Big Cypress Group of the Comanchean Series of the Lower Cretaceous. The Lower Cretaceous lithology is composed of evaporitic-carbonate cycles consisting of anhydrites, dolomites, and limestones. There are also present some calcareous shales, mudstones, salt, lignitic material, and carbonaceous material, especially in the anhydrite and limestone intervals. The limestones are usually micritic, chalky, calcarenitic, sometimes argillaceous, containing skeletal particles ...

1990-09-01

326

NATURAL GAS VARIABILITY IN CALIFORNIA: ENVIRONMENTAL IMPACTS AND DEVICE PERFORMANCE EXPERIMENTAL EVALUATION OF POLLUTANT EMISSIONS FROM RESIDENTIAL APPLIANCES  

Science.gov (United States)

The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens, 5 broiler burners, 5 storage water heaters, 4 forced air furnaces, 1 wall furnace, and 6 tankless water heaters. Air-free concentrations and fuel-based emission factors were determined for carbon monoxide, nitrogen oxides, nitrogen dioxide, and the number of (predominantly ultrafine) particles over complete burns?including transient effects (device warm-up and intermittent firing of burners) following ignition--and during more stable end-of-burn conditions. Formaldehyde was measured over multi-burn cycles. ...

2009-12-01

327

ANALYSIS OF ACCELERATOR BASED NEUTRON SPECTRA FOR BNCT USING PROTON RECOIL SPECTROSCOPY  

Energy Technology Data Exchange (ETDEWEB)

Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase I/II clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra alternative neutron sources are being contemplated for wider ...

1998-11-06

328

Pretargeted radioimmunotherapy in tumored mice using an in vivo {sup 212}Pb/{sup 212}Bi generator  

Energy Technology Data Exchange (ETDEWEB)

Objective: Pretargeting is the concept that combines optimal delivery of the antibody and rapid capture and elimination of the radioactivity. In this study, we evaluated the potential of antibody pretargeting to enable the tumor-targeting {sup 212}Pb for in vivo generation of {sup 212}Bi for {alpha} particle radiotherapy. Methods: The {sup 212}Pb/{sup 212}Bi chelate of DOTA-biotin, as well as their {gamma}-emitting analogues, {sup 203}Pb and {sup 205}Bi, was prepared and characterized. The radiolabeled compounds were injected in animals for evaluation of tumor targeting and normal tissue uptake and retention. In the pretargeting protocol, injection of 400 {mu}g of NR-LU-10 antibody-streptavidin conjugate was given at t=0 h, then 100 {mu}g of N-acetyl-galatosamine-biotin clearing agent was injected at t=20-24 h; finally, 1 {mu}g of {sup 212}Pb/{sup 212}Bi-DOTA-biotin was injected 6 h later. Results: Both {sup 203}Pb and {sup ...

2005-10-01

329

Pulsars as the Sources of High Energy Cosmic Ray Positrons  

CERN Document Server

Recent preliminary results from the PAMELA satellite indicate the presence of a large flux of positrons (relative to electrons) in the cosmic ray spectrum between approximately 10 and 50 GeV. As annihilating dark matter particles in many models are predicted to contribute to the cosmic ray positron spectrum in this energy range, a great deal of interest has resulted from this observation. Here, we consider pulsars (rapidly spinning, magnetized neutron stars) as an alternative source of this signal. After calculating the contribution to the cosmic ray positron and electron spectra from pulsars, we find that the spectrum observed by PAMELA could plausibly originate from such sources. In particular, a significant contribution is expected from the sum of all mature pulsars throughout the Milky Way, as well as from the most nearby mature pulsars (such as Geminga and B0656+14). The signal from nearby pulsars is expected to generate a small but ...

2009-01-01

330

Preparation of a high-J sub c YBCO bulk superconductor by the platinum doped melt growth method  

Energy Technology Data Exchange (ETDEWEB)

Recently we have found a highly effective additive for the melt growth processings attaining high critical currents in YBCO superconductor. It is platinum and it behaves as an effective grain growth inhibitor for the Y{sub 2}BaCuO{sub 5} phase. Even with less than 1 wt.% doping, Y{sub 2}BaCuO{sub 5} particles becomes less than one micron in size and distribute themselves to become homogeneously embedded in the large grown YBa{sub 2}Cu{sub 3}O{sub y} grains. The sample shows large magnetic hysteresis and a typical J{sub c} value estimated by using Bean's model critical state model is 18000 A/cm{sup 2} at 77 K and 1 T. We found that rhodium has a similar remarkable effect. (orig.).

1991-06-15

331

Consolidated silica glass from nanoparticles  

International Nuclear Information System (INIS)

A dense silica glass was prepared by consolidating a highly dispersed silicic acid powder (particle size 1H magic-angle spinning (MAS) NMR confirmed an increase in hydroxyl groups in the sample prepared by SPS relative to that of the conventional SiO2 reference glass. Aside from the comparably high water content, we conclude from the similarity of the IR-reflectance and the 29Si MAS NMR spectra of the SPS sample and the corresponding spectra of the conventionally prepared silica glass, that the short- and medium-range order is virtually the same in both materials. Raman spectroscopy, however, suggests that the number of three- and four-membered rings is significantly smaller in the SPS sample compared to the conventionally prepared sample. Based on these results we conclude that it is possible to prepare glasses by compacting amorphous powders by the SPS process. The SPS process may therefore enable the preparation of glasses with compositions inaccessible by ...

2008-09-01

332

Beam-breakup calculations for the Los Alamos free-electron laser (FEL) linac  

International Nuclear Information System (INIS)

In addition to the usual circularly symmetric TM/sub 010/ mode used to accelerate particles in an rf linac, there is a large number of modes with cos phi or sin phi dependence, for example the TM/sub 1xx/ modes. These latter modes possess a uniform magnetic (dipole) field near the axis of symmetry and therefore can deflect the beam away from the axis. Any portion of an accelerated beam that is off-axis will drive these modes, so that subsequent portions of the beam will be deflected. This deflected beam will then resonantly drive the same modes in downstream cavities, so that still later portions of the beam will be more severely deflected, and so on. In this paper are reported the results of numerical simulations of this so-called cumulative beam-breakup instability. The simulation assumes that only the TM/sub 110/ mode acts to deflect the beam, and further assumes that this mode does not couple from one accelerating cavity to the next.

333

Aspects of Stability Related to the Colliding Beam Fusion = Reactor  

Science.gov (United States)

Recent experiments with TFTR, D-III-D and JET involving the injection and trapping of low density beams of high energy large orbit ions indicate that large orbit non-adiabatic ions slow down and diffuse classically in the presence of anomalous fluctuations and transport of adiabatic majority particles. Accordingly, we consider conceptual fusion reactors(N. Rostoker, M.W. Binderbauer and H.J. Monkhorst, Science) 278, 1419 (1997). based on classical confinement of fuel ions and fusion products(M.W. Binderbauer and N. Rostoker, J. Plasma Phys.) 56, 451 (1996).. The magnetic confinement geometry of the proposed designs is a Field Reversed Configuration. A survey of experimental results on instabilities and their characteristics as related to these reactor concepts is presented. Particular focus will be given to long wavelength (as compared to gyro-radius) and low frequency (?<< c/r_o, r_o=3D major radius of annular current ring) instabilities ...

1998-11-01

334

A superconducting solenoidal spectrometer for a balloon-borne experiment  

Energy Technology Data Exchange (ETDEWEB)

The BESS detector is a new type of balloon-borne spectrometer which utilizes various technologies recently developed for collider experiments. The principal scientific objectives include a measurement of cosmic-ray antiproton spectrum, search for anti-nuclei in cosmic radiation, and precise measurements of cosmic-ray primaries. A thin superconducting solenoidal coil produces a uniform magnetic field of 1 T. Cylindrical drift chambers are located inside and outside the coil and perform continuous tracking. The momentum resolution is 0.5% at 1 GeV/c. i.e., the maximum detectable rigidity is 200 GV. Scintillation counter hodoscopes, placed above and below the solenoid, provide timing and dE/dx measurements and trigger generation. The timing resolution is 80 ps/counter. This cylindrical configuration achieves a large geometrical acceptance of 0.35 m{sup 2} sr which is essential to detect rare cosmic-ray particles. In order to cope with high trigger ...

2000-03-21

335

A study of the effects of scattered radiation on radiographic quality and methods of elimination of such radiation  

International Nuclear Information System (INIS)

Many mechanical parts are subjected to stresses and strains that may eventually lead to their failure. In order to prevent the costly delays associated with equipment down-time, many parts have to be tested for weaknesses and defects when machinery is constructed or dismantled for maintenance. These procedures are known as Non-Destructive Testing (NDT) methods. Five types of non-destructive testing methods routinely used are radiographic testing, ultrasonic testing, magnetic particle inspection, liquid penetrant testing and eddy current testing. Out of these five techniques industrial radiography plays an important role in non-destructive testing to reveal interior defects in materials. In radiography almost two-thirds of the radiation reaching the film is scattered radiation which does not form the image of defects. Scattered radiation generated inside and outside a material has a very large effect on sensitivity of flaw detection since it ...

1998-02-01

336

A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation  

CERN Document Server

A new measurement of the cosmic ray antiproton-to-proton flux ratio between 1 and 100 GeV is presented. The results were obtained with the PAMELA experiment, which was launched into low-earth orbit on-board the Resurs-DK1 satellite on June 15th 2006. PAMELA is equipped with a silicon-microstrip magnetic spectrometer and a silicon-tungsten imaging calorimeter and has been collecting data since July 2006. During 500 days of data collection a total of about 1000 antiprotons have been identified, including 100 above an energy of 20 GeV. The high-energy results are a ten-fold improvement in statistics with respect to all previously published data. The antiproton-to-proton flux ratio increases smoothly with energy up to about 10 GeV, in agreement with previous experiments, and then levels off. The data follow the trend expected from secondary production calculations and significantly constrain contributions from exotic sources, e.g. dark matter ...

2008-01-01

337

Design of a magnetic braking system  

International Nuclear Information System (INIS)

A non-contact method, using magnetic drag force principle, was proposed to design the braking systems to improve the shortcomings of the conventional braking systems. The extensive literature detailing all aspects of the magnetic braking is briefly reviewed, however little of this refers specifically to upright magnetic braking system, which is useful for industries. One of the major issues to design upright magnetic system is to find out the magnetic flux. The changing magnetic flux induces eddy currents in the conductor. These currents dissipate energy in the conductor and generate drag force to slow down the motion. Therefore, a finite element model is developed to analyze the phenomena of magnetic flux density when air gap and materials of track are varied. The verification shows the predicted magnetic flux is within ...

2006-09-01

338

Status of lead and bismuth for radioimmunoimaging and radioimmunotherapy  

International Nuclear Information System (INIS)

Tumor-targeted monoclonal antibodies (mAb) might be useful as diagnostic or therapeutic agents when linked to cytotoxic or imaging reagents. Our group is working to test this hypothesis by linking cytocidal and image-producing isotopes to mAb and testing the utility of the radioimmunoconjugates formed in animal model systems. Radioiodines were first employed for these purposes,but unfavorable nuclear properties (half-lives, #gamma#-ray and #beta#-particle energies) and chemical reactivity (deiodination in vivo) limit their utility. Labeling immunoproteins with metallic radionuclides offers more versatility in that the selection of potentially useful radiometals spans the periodic table.Of the metallic radionuclides with physical properties most suited for use with mAb in nuclear medicine, few are more available or desirable than those of bismuth ("2"1"2Bi) and lead ("2"0"3Pb, "2"1"2Pb), as listed in Table 1. "2"1"2Bi or "2"1"2Pb could serve as ...

1990-08-26

339

Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh  

Energy Technology Data Exchange (ETDEWEB)

Several reactions producing odd-Z transactinide compound nuclei were studiedwith the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the LawrenceBerkeley National Laboratory. The goal was to produce the same compound nucleus ator near the same excitation energy with similar values of angular momentum via differentnuclear reactions. In doing so, it can be determined if there is a preference in entrancechannel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's"Fusion By Diffusion" model is nearly identical forthe two reactions. Additionally, because the same compound nucleus is produced, theexit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. ...

2008-05-14

340

Targeting Prostate Cancer Cells In Vivo Using a Rapidly Internalizing Novel Human Single-Chain Antibody Fragment  

UK PubMed Central (United Kingdom)

Human antibodies targeting prostate cancer cell surface epitopes may be useful for imaging and therapy. The objective of this study was to evaluate the tumor targeting of an internalizing human...Full Text Available

2010-03-01

342

Isoform-level microRNA-155 target prediction using RNA-seq  

UK PubMed Central (United Kingdom)

Computational prediction of microRNA targets remains a challenging problem. The existing rule-based, data-driven and expression profiling approaches to target prediction are mostly approached from the...Full Text Available

2011-05-01

343

Delineating Bacteriostatic and Bactericidal Targets in Mycobacteria Using IPTG Inducible Antisense Expression  

UK PubMed Central (United Kingdom)

In order to identify novel high value antibacterial targets it is desirable to delineate whether the inactivation of the target enzyme will lead to bacterial death or stasis. This knowledge is particularly...Full Text Available

344

A thermal hydraulic investigation on ADSR liquid lead target  

Energy Technology Data Exchange (ETDEWEB)

Computational fluid dynamics(CFD) code FLUENT was used to simulate the thermal hydraulic processes occurring in conceptual design of the accelerator-driven subcritical reactor(ADSR) liquid lead target. The purpose of the analysis is to investigate the thermal hydraulic characteristics of liquid lead as ADSR target material with various target geometries and injection locations of proton beam. In the calculation analysis, the local temperature of the liquid lead target rises to the boiling temperature very rapidly. When the proton beam is injected from the bottom of the target system, the duration time to reach the boiling temperature is longer and the temperature distribution is flatter than other cases.

1998-05-01

345

Magnetic resonance imaging. Handbook and atlas; Kernspintomographie. Kompendium und Atlas  

Energy Technology Data Exchange (ETDEWEB)

Magnetic resonance imaging (MRI) as a diagnostic imaging tool relies on the generation of magnetic fields, whereas the computerized tomography (CT) uses X-radiation. The fundamental principle of MRI is the magnetic resonance of paramagnetic atomic nuclei. These nuclei, as e.g. protons (= hydrogen nuclei), are aligned in required orientation by application of a strong magnetic field. Upon simultaneous application of an electromagnetic high-frequency field perpendicular to the axis of the basic magnetic field, and in response to periodical changing of the electromagnetic field at a given frequency, the originally aligned paramagnetic nuclei are forced into a movement similar to that of a ``whipping top``. When the resonance frequency is shut off, the nuclei return to their former, aligned positions, inducing a weak signal in a coil. The series of signals generated by multiple ...

1999-10-01

346

Dayside auroral activity and magnetospheric boundary layer phenomena  

Energy Technology Data Exchange (ETDEWEB)

Selected case studies of auroral structure/activity observed at different local times on the dayside are presented and discussed in the context of electrodynamic coupling between the different magnetospheric boundary regions and the ionosphere. The first case addresses the question of the auroral signatures of the two boundary regions referred to as cusp and cleft/LLBL. Combined ground-based and satellite data reveal the different latitudinal zones of auroral forms/particle precipitation/field-aligned current and the relationship with the respective magnetospheric plasma populations, i.e. CPS, BPS, LLBL, and the plasma mantle. Midday auroral breakup events and the related ionospheric ion drift and magnetic observations show many of the features that have been predicted to be ionospheric signatures of flux transfer events. An alternative explanation that has been proposed by others, i.e. ionospheric effect of magnetopause perturbations excited ...

1990-07-01

347

The response of small scale rigid targets to shallow buried explosive detonations  

British Library Electronic Table of Contents (United Kingdom)

Experimental and computational investigations were performed in order to better understand the mechanical response of rigid targets with various geometries to the detonation of shallow buried explosives. The motion of the targets was measured by use of high-speed digital video photography. This work involved flat targets, targets that were downwardly convex, and targets that were downwardly concave with explosive charges located at various positions beneath the targets. It was observed that, in general, angled hulls - whether downwardly concave or convex - tended to reduce the amount of momentum imparted to the center of mass of the targets. Computations were performed by use of an arbitrary Langrangian-Eulerian treatment in a nonlinear finite element code. A model based on quasi-static te...

2011-01-01

348

Targeting a Ruthenium Complex to the Nucleus with Short Peptides  

UK PubMed Central (United Kingdom)

In an effort to develop octahedral metal complexes as chemotherapeutic and diagnostic agents targeted to DNA, it is critical to optimize the properties of their cellular uptake. Appending d-octaarginine...Full Text Available

2010-05-15

349

Target stations and beam dumps for the CERN SPS  

International Nuclear Information System (INIS)

The design of the absorber blocks for internal and external dumping of the SPS proton beam is discussed. In addition, the external target stations for slow and fast extracted proton beams are described.

1977-03-16

350

Suitability of a New Plant Invader as a Target for Biological Control in Florida  

Science.gov (United States)

... L. Sutton. 2000. Is the aquatic weed hygrophila, Hygrophila polysperma (Polemoniales: Acanthaceae), a suitable target for classical biological ... ...

351

Nato SCI-12 on Camouflage Evaluation Workshop on Search and Target ...  

Science.gov (United States)

Nato SCI-12 on Camouflage Evaluation Workshop on Search and Target Acquisition The Netherlands, June 1999. Image Discrimination Models for Object Detection ...

352

FOR THIN AND THICK TARGETS - NASA Technical Report Server (NTRS)  

Science.gov (United States)

By W. Wayne Scott. Langley Research Center. SUMMARY. Thin- and thick-target bremsstrahlung spectra are presented for electron energies up to 7.0 MeV. ...

353

Magnetization reversal phenomena and domain wall behaviours in nanostructured magnetic systems  

International Nuclear Information System (INIS)

Several recent experiments on micro- (or nano-) structured samples of ferromagnetic materials are introduced. Magnetization reversal phenomena are investigated on submicron wire samples of trilayer structure using the giant magnetoresistance effect. Domain wall movements are sensitively monitored by resistivity measurements and the velocity of propagation is determined. The contribution of domain wall to the resistivity is argued from the results on artificially designed samples of a spring-magnet system. In circular dots of permalloy, the existence of vortex magnetization is confirmed and the reversal of the vortex core magnetization is studied from magnetic force microscopy measurements. (author)

2001-09-23

354

Magnetic fluctuation measurement in Sino United Spherical Tokamak plasma  

International Nuclear Information System (INIS)

To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10 kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape-off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge. (authors)

2007-07-01

355

Accuracy of patient dose calculation for lung IMRT: A comparison of Monte Carlo, convolution/superposition, and pencil beam computations  

International Nuclear Information System (INIS)

The accuracy of dose computation within the lungs depends strongly on the performance of the calculation algorithm in regions of electronic disequilibrium that arise near tissue inhomogeneities with large density variations. There is a lack of data evaluating the performance of highly developed analytical dose calculation algorithms compared to Monte Carlo computations in a clinical setting. We compared full Monte Carlo calculations (performed by our Monte Carlo dose engine MCDE) with two different commercial convolution/superposition (CS) implementations (Pinnacle-CS and Helax-TMS's collapsed cone model Helax-CC) and one pencil beam algorithm (Helax-TMS's pencil beam model Helax-PB) for 10 intensity modulated radiation therapy (IMRT) lung cancer patients. Treatment plans were created for two photon beam qualities (6 and 18 MV). For each dose calculation algorithm, patient, and beam quality, the following set of clinically relevant dose-volume values was reported: (i) minimal, median, ...

2006-09-01

361

Neutron magnetic scattering studies on ferromagnetism in potassium nanoclusters arrayed in zeolite A-Trial experiments  

Energy Technology Data Exchange (ETDEWEB)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be ...

2009-02-21

362

Neutron magnetic scattering studies on ferromagnetism in potassium nanoclusters arrayed in zeolite A-Trial experiments  

International Nuclear Information System (INIS)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be ...

2009-02-21

363

Target area chamber system design for the National Ignition Facility  

International Nuclear Information System (INIS)

The National Ignition Facility (NIF) is a proposed Department of Energy facility which will contribute to the resolution of important Defense Program and inertial fusion energy issues for energy production in the future. The NIF will consist of a laser system with 192 independent beamlets transported to a target chamber. The target chamber is a multi-purpose structure that provides the interface between the target and the laser optics. The chamber must be capable of achieving moderate vacuum levels in reasonable times; it must remain dimensionally stable within micron tolerances, provide support for the optics, diagnostics, and target positioner; it must minimize the debris from the x-ray and laser light environments; and it must be capable of supporting external neutron shielding. The chamber must also be fabricated from a low neutron activation material. The fusion reaction in the ...

1994-06-19

364

Spin-resolved magnetic studies of focused ion beam etched nano-sized magnetic structures  

International Nuclear Information System (INIS)

Scanning ion microscopy with polarization analysis (SIMPA) is used to study the spin-resolved surface magnetic structure of nano-sized magnetic systems. SIMPA is utilized for in situ topographic and spin-resolved magnetic domain imaging as well as for focused ion beam (FIB) etching of desired structures in magnetic or non-magnetic systems. Ultra-thin Co films are deposited on surfaces of Si(1 0 0) substrates, and ultra-thin, tri-layered, bct Fe(1 0 0)/Mn/bct Fe(1 0 0) wedged magnetic structures are deposited on fcc Pd(1 0 0) substrates. SIMPA experiments clearly show that ion-induced electrons emitted from magnetic surfaces exhibit non-zero electron spin polarization (ESP), whereas electrons emitted from non-magnetic surfaces such as Si and Pd exhibit zero ESP, which can be used to calibrate sputtering rates in situ. We ...

2005-04-01

365

Solid particle receiver experiments: velocity measurements  

Energy Technology Data Exchange (ETDEWEB)

Laser Doppler velocimetry and other photometric techniques are evaluated for measuring the average particle velocity in an ensemble of free-falling particles. The ability to obtain measurements in the presence of a radiant flux as high as 0.6 MW/m/sup 2/ was part of the evaluation. Optically dissimilar particles with diameters ranging from 0.1 mm to 1 mm were used in the study. Experimental results indicate that ensembles of particles do not behave as single isolated particles. The particle motion is dependent on particle volume fraction, and is quite unstable for falls greater than one meter.

1984-10-01

366

Solid particle receiver experiments: velocity measurements  

Science.gov (United States)

Laser Doppler velocimetry and other photometric techniques are evaluated for measuring the average particle velocity in an ensemble of free-falling particles. The ability to obtain measurements in the presence of a radiant flux as high as 0.6 MW/m/sup 2/ was part of the evaluation. Optically dissimilar particles with diameters ranging from 0.1 mm to 1 mm were used in the study. Experimental results indicate that ensembles of particles do not behave as single isolated particles. The particle motion is dependent on particle volume fraction, and is quite unstable for falls greater than one meter.

1984-10-01

367

Small world when building a particle detector prototype, the devil is in the tiny details  

CERN Multimedia

Small world when building a particle detector prototype, the devil is in the tiny details

2004-01-01

368

Particle-Sizing System for Scanning Electron Microscope ...  

Science.gov (United States)

... THESIS PARTICLE-SIZING SYSTEM FOR SCANNING ELECTRON MICROSCOPE IMAGES OF SOLID-PROPELLANT COMBUSTION EXHAUST ...

1991-03-01

369

Kootenai River Nutrient Dosing System and N-P Consumption: Year 2008.  

Science.gov (United States)

In early 2006 we designed and built low energy consumption, pump-operated system, for dosing of the liquid nutrient in the summer 2006 season. This operated successfully, and the system was used again during the 2007 and 2008 seasons for dosing. During the early winter period, 2008, laboratory tests were made of the liquid nutrient pump system, and it was noted that small amounts of air were being entrained on the suction side of the pump, during conditions when the inlet pressure was low. It was believed that this was the cause of diurnal fluctuations in the flow supplied, characteristic of the 2007 year flow data. Replacement of '0' rings on the inlet side of the pumps was the solution to this problem, and when tested in the field during the summer season, the flow supplied was found to be stable. A decision was made by the IKERT committee at the meeting of 20th to 21st May 2008 (held in Coeur d'Alene, Idaho) to use an injection flow rate of liquid ...

2009-02-19

370

Monthly report of activities: APRIL 1, 1969  

Science.gov (United States)

This is the first of a series of monthly reports summarizing the status of the work of the National Accelerator Laboratory. This first report will cover developments since the publication of the Design Report in January. Authorization hearings were held before the Joint Committee on Atomic Energy on February 21, 1968. Dr. Wilson described the plans and designs of the Laboratory. The present plan of the Laboratory is that the Village of Weston will be utilized for office, laboratory, and shop space during construction. The Laboratory business office is already occupying several houses. The linac section is occupying three houses for offices and construction of an 8,000 sq ft laboratory building for linac work is almost complete. Another house is being used and a 4,500 sq ft inflatable building is being constructed for model-magnet and vacuum testing. Other temporary buildings will be constructed for use by other sections. We plan to move into the village as rapidly ...

1968-04-01

371

Target R and D at JAERI  

Energy Technology Data Exchange (ETDEWEB)

We proposed a solid and a mercury target concepts through the preliminary conceptual design. To feasible these concepts, analysis and experimental works are being carried out. This paper introduces an outline of present status of target R and D such as heat transfer augmentation experiments for the solid target, mercury flow tests with a loop of maximum flow rate of 15L/min, flow pattern measurements for a cold source moderator etc. as well as preliminary conceptual design works. (author)

1999-03-01

376

Concepts of radiotherapy treatment planning  

International Nuclear Information System (INIS)

Full text: Radiotherapy treatment planning (RTP) relies heavily on medical imaging. Until recently, the most important planning tool was the treatment simulator. The kilovoltage radiographic capabilities in a treatment simulator enabled the boundaries of treatment fields to be visualized with respect to bony anatomic landmarks. Perhaps the most important advance in treatment planning in recent years is the ability to visualize the passage of the beams with respect to a more accurate geometrical representation of the tumor and other soft tissue structures. This 'virtual simulation' uses a computer-based representation of a patient to determine the extent of the disease and the location of radiation sensitive normal tissue. Computer tomographic (CT) imaging produces a high-resolution three-dimensional representation of anatomy that can be correlated with other image sets such as magnetic resonance images (MRI) of function. Positron emission tomographic (PET) imaging ...

2000-12-01

377

The effective longitudinal dielectric constant for plasmas in inhomogeneous magnetic fields  

Scientific Electronic Library Online (English)

Abstract in english We present a detailed derivation of the effective dielectric constant to be used in the dispersion relation for electrostatic waves in the case of a plasma immersed in a inhomogeneous magnetic field, with inhomogeneity perpendicular to the direction of the magnetic field.

2004-09-01

378

Magnetic mirror fusion systems: Characteristics and distinctive features  

Energy Technology Data Exchange (ETDEWEB)

A tutorial account is given of the main characteristics and distinctive features of conceptual magnetic fusion systems employing the magnetic mirror principle. These features are related to the potential advantages that mirror-based fusion systems may exhibit for the generation of economic fusion power.

1987-08-10

379

Magnetic fields of x-ray pulsars  

Energy Technology Data Exchange (ETDEWEB)

An analytic model of magnetic torques applied to an accreting neutron star is employed to evaluate the magnetic dipole moments of x-ray pulsars. A new type of close binary system containing a neutron star is suggested.

1982-09-01

380

Magnetic excitations studied with time-of-flight spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

An introduction to time-of-flight neutron spectroscopy is presented in the context of the study of magnetic materials. Examples are taken from the class of rare earth and actinide magnetic materials known as `strongly correlated electron` systems. (author) 11 figs., 24 refs.

1996-11-01

381

Eddy Current Inspection of Mildly Ferromagnetic Tubing.  

Science.gov (United States)

The past decade has seen the development of eddy current probes for inspection of the mildly ferro-magnetic alloy Monel 400. Due to the rapid advances in permanent magnet technology similar probes have been upgraded to magnetically saturate, and hence ins...

1984-01-01

382

Active magnetic regenerator  

Energy Technology Data Exchange (ETDEWEB)

The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

1982-01-01

383

Nanocrystalline permanent magnets with enhanced properties  

International Nuclear Information System (INIS)

Parameters of permanent magnets result from the combination of intrinsic properties such as saturation magnetization, magnetic exchange, and magnetocrystalline energy, as well as microstructural parameters such as phase structure, grain size, and orientation. Reduction of grain size into nanocrystalline regime (#approx# 50 nm) leads to the enhanced remanence which derives from ferromagnetic exchange coupling between highly refined grains. In this study the fundamental phenomena, quantities, and structure parameters, which define nanophase permanent magnets are presented and discussed. The theoretical considerations are confronted with experimental data for nanocrystalline Sm-Fe-N type permanent magnets. (author)

2001-09-23

384

Untitled - NASA Technical Report Server (NTRS)  

Science.gov (United States)

Principle advantages of magnetic forming for part manufacture appear to lie ... to be an area of great potential for the magnetic forming process. We have a ...

385

Symptoms of the musculoskeletal system and exposure to magnetic fields in an aluminium plant.  

UK PubMed Central (United Kingdom)

OBJECTIVE--The study was performed to examine the influence of the exposure to magnetic fields in the potrooms of an electrolysis plant on the occurrence of musculoskeletal symptoms among the employees....Full Text Available

1995-08-01

386

Refrigerator operating experience on whole body MRI magnet systems  

International Nuclear Information System (INIS)

Several refrigerators for liquid helium and liquid nitrogen systems have been integrated successfully into IGC manufactured whole body Magnetic Resonance Imaging (MRI) magnet systems. The refrigerators have been tested in systems with magnetic fields of 0.6T to 1.5T. Tests were performed to study the effectiveness of the refrigerators, the magnetic field effects on the refrigerators, the effect of the refrigerators on the field uniformity and magnetic resonance image quality. The interface between the refrigerator and the whole body MRI magnet system cryostat was specifically designed to allow retrofit to the existing IGC magnet systems, while ensuring good heat transfer characteristics and good vibration isolation from the cryostat. The interface between the refrigerator and the cryostat and the refrigerator test results are presented.

1985-08-01

387

Progress on the Design and Fabrication of the MICE Focusing Magnets  

Energy Technology Data Exchange (ETDEWEB)

The Muon Ionization Cooling Experiment (MICE) focusing solenoid magnets focus the muon beam within the MICE cooling channel on a liquid or solid absorber that is within the warm bore of solenoid. The focusing magnet has a warm bore of 470 mm. his magnet consists of two coils 210-mm long that is separated by an aluminum mandrel that is 200 mm long. Each of the coils has its own leads. The coils may be operated in either the non-flip mode (solenoid mode with both coils at the same polarity) or the lip mode (quadrupole focusing mode where both coils are at opposite polarity). This report describes the focusing solenoid magnet design that will be built by the vendor. The progress on the construction of the first of the focusing magnets will also be discussed in this report. Ultimately three of these magnets will be built. These magnets will be ...

2009-10-19

388

Possible observation of the coexistence of superconductivity and long-range magnetic order in NdRh_4B_4  

International Nuclear Information System (INIS)

The ternary rare earth compound NdRh_4B_4 has been studied by means of critical field, low temperature heat capacity, and static magnetic susceptibility measurements. Features in the upper critical field and heat capacity data at 1.31 K and 0.89 K suggest the occurrence of long-range magnetic order in the superconducting state. The temperature dependence of the static magnetic susceptibility follows a Curie-Weiss law with an effective magnetic moment #mu#sub(eff) = 3.58 +- 0.05 #mu#sub(B) and a Curie-Weiss temperature thetasub(p) = -6.2 +- 1.0 K between 20 K and room temperature. However, magnetization vs. applied magnetic field isotherms suggest the development of a ferromagnetic component in the Nd"3"+ magnetization at low temperatures. (author).

1979-01-01

389

PLASMA JET WELDING, COATING, AND CUTTING: AN ...  

Science.gov (United States)

... 31. New electric forming methods offer potentials for light metals; magnetic forming and plasma forming. ... 3, 25 Magnetic Forming ..... ...

1963-02-01

390

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates  

Energy Technology Data Exchange (ETDEWEB)

Highly ordered arrays of Ni nanoholes and Fe{sub 20}Ni{sub 80} antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density ...

2008-07-15

391

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates  

International Nuclear Information System (INIS)

Highly ordered arrays of Ni nanoholes and Fe20Ni80 antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density ...

2008-07-01

392

Mechanism of viscosity effect on magnetic island rotation  

Energy Technology Data Exchange (ETDEWEB)

It is shown that plasma viscosity does not influence the magnetic island rotation directly. Nevertheless, it leads to nonstationarity of the plasma velocity. This nonstationarity is the reason of the viscosity effect on island rotation. (author)

2000-04-01

393

Magnetic Properties of Ni Nanoparticles Embedded in ...  

Science.gov (United States)

... M(TH) in applied magnetic fields up to ± 7 T and for temperatures ranging from 2 to 300 K. The superparamagnetic (SPM) behavior of these metallic ...

2011-05-14

394

Localization of small magnets against a noisy background  

Science.gov (United States)

Effective localization of small magnets against a noisy, real world background can involve various methods to first identify the magnetic fields produced by the magnet of interest, then to filter out background noise, and then to analyze the available magnetic field data to localize the magnet. Here we discuss low cost techniques which allow localization of small magnets with field strengths in the milliGauss range against real world background fields in the range of hundreds of mG, which may be fluctuating by up to tens of mG. Such techniques allow magnet tracking to be used to localize catheters in place of more invasive and expensive methods, e.g. fluoroscopy, for a variety of applications, including drug infusion with peripherally inserted central catheters (PICCs), laser ablation (TMR, PTMR) and introduction of pacemaker leads.

2001-05-01

395

Hypoxia and Magnetic Therapy for Personnel Radiation Protection  

International Science & Technology Center (ISTC)

Development of Portable Normobaric Hypoxia and Pulsed Magnetic Field Firmware System for Enhancement of Radio- and Non-specific Resistance in Workers of Environmentally Hazardous Industries

396

Geometry effects in the pulsed magnetization of high-temperature superconductor bulk parts  

International Nuclear Information System (INIS)

The dynamic response of cylindrical and ring-shaped YBaCuO bulk parts to pulsed magnetic fields is calculated by using small sets of finite elements. Some comparisons with experimental results are provided, and they give confidence in the modelling of the superconducting properties. Transient magnetizations as a function of time and space as well as shapes and absolute values of trapped magnetic flux profiles are presented. The influence of the sample geometry is investigated for different millisecond pulsed magnetization processes. Results are reported for different radial thicknesses and heights, different pulse durations, peak magnetic fields and pulse sequences with and without stepwise cooling. Comparisons concerning the achievable trapped magnetic field and flux are made, and implications for the use of high-temperature superconductor bulk parts as ...

2005-02-01

397
398

Evaluation of Commercial Magnetic Descalers.  

Science.gov (United States)

With the increased costs of maintaining boilers and chillers entrepreneurs around the country have offered magnetic and similar devices to facilities as viable alternatives to their maintenance program. This report gives a brief history of some of the pre...

1984-01-01

399

Develop Magnetic Coil Design and Manufacturing Capability.  

Science.gov (United States)

... design, and manufacturing knowledge have been acquired and used to develop an 'in-house' capability for the fabrication of magnetic forming coils ...

1974-11-01

401

CONTRACT: NAS 8-11811 DESIGN, DEVELOPMENT, MANUFACTURE, AND ...  

Science.gov (United States)

has been generally related to magnetic forming. One of the methods suggested was the following: A "pancake" magnetic coil is placed over a thin aluminum ...

402

Application of the grazing angle polarized neutron reflectometry to study the magnetism in thin films and stratified media  

Energy Technology Data Exchange (ETDEWEB)

From optical point of view and due to the magnetic interaction of the cold neutrons with the unpaired electron shell, magnetic materials hae a neutron spin-dependent refractive index n[sup +] [spin up] and n[sup -] [spin down]. Magnetic media such as Fe, Co and Ni react like birefringent uniaxial crystals in ordinary optica. n[sup +] and n[sup -] are the equivalent of the ordinary and extraordinary refractive indices. The specular reflection of spin polarized neutrons which is due to the discontinuity of the magnetic induction at the surface of the ferromagnet is a sensitive probe of surface and interface magnetism. We shall first give the background of the art of polarized neutron optics. Secondly, some recent examples from surface and interface magnetism will be given to illustrate the power of this technique such as the magnetic coupling ...

1992-12-01

403

Anisotropic forming of magnetic powders mixed with ultraviolet resin; Shigaisen koka jushi wo mochiita jisei funmatsu no haiko seikei  

Energy Technology Data Exchange (ETDEWEB)

For the purpose of solving the limitations such as shape and dimension for magnetic compact fabricated by conventional anisotropic forming under magnetic orienting field, the feasibility of a new magnetic forming process was studied. Ferrite powder mixed with UV resin was compacted in the die mold and followed by alignment under the magnetic field. Effects of viscosity of UV resin and forming condition on magnetic characteristics of the compact was investigated. Maximum degree of alignment for the ferrite powder reached to 0.826. It was predicted that the proposed method had make it possible to fabricate a high performance magnet having the anisotropic alignment of the magnetic powder. The UV resin is desirable to have low viscosity, good properties such as formability and configuration stability for the compact and also parting- ability ...

1999-01-15

404

An Advance in Superconducting Magnet Technology Opens the Door...  

Science.gov (United States)

magnet research at several national laboratories through its Advanced Accelerator Technology Program. The HEP Conductor Development Program, a collaboration among national...

2011-08-20

405

Development of a geometrically accurate imaging protocol at 3 Tesla MRI for stereotactic radiosurgery treatment planning  

International Nuclear Information System (INIS)

The purpose of this study is to develop a geometrically accurate imaging protocol at 3 T magnetic resonance imaging (MRI) for stereotactic radiosurgery (SRS) treatment planning. In order to achieve this purpose, a methodology is developed to investigate the geometric accuracy and stability of 3 T MRI for SRS in phantom and patient evaluations. Forty patients were enrolled on a prospective clinical trial. After frame placement prior to SRS, each patient underwent 3 T MRI after 1.5 T MRI and CT. MR imaging protocols included a T1-weighted gradient echo sequence and a T2-weighted spin echo sequence. Phantom imaging was performed on 3 T prior to patient imaging using the same set-up and imaging protocols. Geometric accuracy in patients and phantoms yielded comparable results for external fiducial reference deviations and internal landmarks between 3 T and 1.5 T MRI (mean ?0.6 mm; standard deviation ?0.3 mm). Mean stereotactic reference deviations between phantoms and ...

2010-11-21

406

Chemistry of transuranium elements and compounds  

International Nuclear Information System (INIS)

Studies are made in this program to enhance our understanding of the role of 5f electrons in chemical bonding. Most of our studies on the macroscopic scale emphasize certain isotopes available from the National Transplutonium Production Program centered at HFIR/TRU -namely, _9_6"2"4"8Cm, _9_7"2"4"9Bk, _9_8"2"4"9Cf, _9_9"2"5"3Es, and _9_9"2"5"4Es. Particular classes of compounds, such as hydrides, chalcogenides, and pnictides are often selected for study on the basis of their utility in bringing out significant chemical differences between the lanthanides and the actinides. High temperature/high pressure experiments on actinide metals and compounds reveal characteristics about the degree of 5f electron localization as a function of atomic number in the series. Magnetic properties of metals and compounds are investigated using ultra-sensitive methods and hydration numbers of ions in solution are investigated by neutron scattering at HFIR. As a result of a recently ...

1986-05-01

407

Magnetic properties of a SmNiSn single crystal  

Energy Technology Data Exchange (ETDEWEB)

The magnetic properties of a single crystal of SmNiSn with the orthorhombic {epsilon}-TiNiSi-type crystal structure have been investigated by magnetic susceptibility, magnetization and electrical resistivity measurements from 1.5 K to room temperature. Two anomalies have been found in the magnetic susceptibility, indicating an antiferromagnetic phase transition at T{sub N}=9.4 K and a second transition at 4.4 K. A large magnetic anisotropy has been found at low temperatures in the temperature and field dependencies of magnetic susceptibility and magnetization. Below 80 K, the easy axis of the magnetization is the c-axis. At T=2.0 K, the c-axis magnetization curve exhibits metamagnetic-like behavior at H{sub c}=42 kOe and reaches 0.54 emu/g at H=55 kOe, whereas for the a- and b-axis the ...

2003-04-01

408

Development of magnetic drive packless valves for commercial purpose  

Energy Technology Data Exchange (ETDEWEB)

A study on development of magnetic drive packless valves for commercial purpose showed the results as follows; 1. Study on the radial rays effecting to the permanent magnets -Measurement of the strength of Nd-magnets according to irradiation of radial rays. 2. Effects of temperature on the magnetic driving device -Temperature dependency of the Nd-casting magnets. -Effects of temperature on the heat releasing fins of high-temperature valve. 3. Optimization of torque -Arranging method of permanent magnets -Measuring method and results of torque. 4. Design, manufacture and test for the pressure-resisting structure of magnetic power transmitting device -Calculation and design for the flat circular plates under pressure of the magnetic power transmitting device -Design, manufacture and test for the pressure-resisting ...

1995-09-01

409

Challenges in fabrication of 180deg magnet chamber  

International Nuclear Information System (INIS)

180 deg magnet chamber is used in Folded Tandem Ion Accelerator for passage and 180 deg bending of ion beam. The chamber is placed between 180 deg terminal magnet (Electro-magnet), which is used for bending, and analysing the beams. Magnet with a particular magnetic field strength bends ions of only specified mass energy product through a precise path. There is also a space limitation in the direction of magnetic field. Both of them require the magnet chamber to be of a close tolerance. Accuracy of center distance between inlet and outlet port of the magnet chamber has to be at par with the concentricity of high energy and low energy beam line. To achieve this we started the fabrication of magnet chamber by following two methods: a) Circular rolling and bending of rectangular tube for 180 deg sector ...

2006-11-01

410

AC loss measurements of model and full size 50mm SSC collider dipole magnets at Fermilab  

Energy Technology Data Exchange (ETDEWEB)

Tests have recently been performed at Fermilab in order to measure the energy losses due to eddy currents and iron and superconductor magnetization. These measurements were performed on six 1.5m long model magnets and eight 15m long full scale collider dipole magnets. AC losses were measured as a function of ramp rate using sawtooth ramps from 500, to 5000 Amps for both types of magnets, while bipolar studies were additionally performed on some of the short magnets. The measured magnet voltage and current for a complete cycle are digitally integrated to yield the energy loss per cycle. Measurement reproducibility is typically 5%, with good agreement between long magnet measurements and extrapolations from short magnet measurement results. Magnetization loss measurements among similar ...

1992-09-01

411

Formation of particles in combustion of biofuels  

International Nuclear Information System (INIS)

Biomass combustion is an important part in a sustainable energy system, but as well a source of submicron (particles < 1 #mu#m) particles in the air. Consequently, to obtain a good air quality together with increased biomass combustion there is a need for a better understanding of particle formation. This work is a part of a larger project about formation and emissions of particles from biofuel combustion. The report includes the work performed in the project during the year 2004. The aim of the project is to describe the release of inorganic components, which cause particle emissions, during combustion of single fuel particles of biofuel, e.g. wood pellets. The work is carried out by emission measurements, systematic combustion experiments and modelling work. The results are expected to contribute to the understanding of which parameters that influence the ...

412

X-RAY MICROANALYSIS OF A RADIOACTIVE PARTICLE WITH THE AID OF THE ELECTRON MICROSCOPE  

Science.gov (United States)

A radioactive particle was analyzed to discover the composition of the inactive material of the particle. The method uses the x-ray line spectrum of the K series caused by electron irradiation of the particle in the electron microscope. Iron and aluminum or silicon (the last two could not be distinguished) were found as inactive components in the particle. (D.L.C.)

1962-07-28

413

Method of removing entrained particles from flue gas and composition of matter  

Energy Technology Data Exchange (ETDEWEB)

A composition of matter to treat particles entrained in flue gas, is described comprising: a caustic liquid used to adjust resistivity of the entrained particles; and inert particulate matter supporting the caustic liquid for inhibiting chemical action of the caustic liquid until used to adjust the resistivity of the entrained particles, the inert particulate matter supporting sufficient caustic liquid to adjust the resistivity of the entrained particles.

1988-04-19

414

Metal nanoparticle inks  

Energy Technology Data Exchange (ETDEWEB)

Stabilized silver particles comprise particles comprising silver, a short-chain capping agent adsorbed on the particles, and a long-chain capping agent adsorbed on the particles. The short-chain capping agent is a first anionic polyelectrolyte having a molecular weight (Mw) of at most 10,000, and the long-chain capping agent is a second anionic polyelectrolyte having a molecular weight (Mw) of at least 25,000. The stabilized silver particles have a solid loading of metallic silver of at least 50 wt %.

2011-04-12

415

Continuous flow dielectrophoretic particle concentrator  

Energy Technology Data Exchange (ETDEWEB)

A continuous-flow filter/concentrator for separating and/or concentrating particles in a fluid is disclosed. The filter is a three-port device an inlet port, an filter port and a concentrate port. The filter separates particles into two streams by the ratio of their dielectrophoretic mobility to their electrokinetic, advective, or diffusive mobility if the dominant transport mechanism is electrokinesis, advection, or diffusion, respectively.Also disclosed is a device for separating and/or concentrating particles by dielectrophoretic trapping of the particles.

2007-04-17

418

The Effect of Static Magnetic Forces on Water Contents and Photosynthetic Pigments in Sweet Basil Ocimum basilicum L. (Lamiaceae)  

International Nuclear Information System (INIS)

Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but ...

419

THE APPLICATION OF STEEP PULSE CURRENTS TO THE ...  

Science.gov (United States)

... Title : THE APPLICATION OF STEEP PULSE CURRENTS TO THE ELECTROHYDRAULIC AND MAGNETIC FORMING OF METALS. ...

1966-04-01

425

Recovery Effects of a 180?mT Static Magnetic Field on Bone Mineral Density of Osteoporotic Lumbar Vertebrae in Ovariectomized Rats  

UK PubMed Central (United Kingdom)

The effects of a moderate-intensity static magnetic field (SMF) on osteoporosis of the lumbar vertebrae were studied in ovariectomized rats. A small disc magnet (maximum magnetic flux density 180 mT)...Full Text Available

2011-01-01

426

QCCM - Center for NMR Quantum Information Processing  

Science.gov (United States)

... decoherence. Descriptors : *QUANTUM COMPUTING, NUCLEAR MAGNETIC RESONANCE, JOSEPHSON JUNCTIONS. Subject ...

2011-02-16

427

Perpendicular magnetic anisotropy of ultrathin FeCo alloy films on Pd(0 0 1) surface: First principles study  

International Nuclear Information System (INIS)

Using the full potential linearized augmented plane wave (FLAPW) method, thickness dependent magnetic anisotropy of ultrathin FeCo alloy films in the range of 1 monolayer (ML) to 5 ML coverage on Pd(0 0 1) surface has been explored. We have found that the FeCo alloy films have close to half metallic state and well-known surface enhancement in thin film magnetism is observed in Fe atom, whereas the Co has rather stable magnetic moment. However, the largest magnetic moment in Fe and Co is found at 1 ML thickness. Interestingly, it has been observed that the interface magnetic moments of Fe and Co are almost the same as those of surface elements. The similar trend exists in orbital magnetic moment. This indicates that the strong hybridization between interface FeCo alloy and Pd gives rise to the large magnetic moment. Theoretically calculated ...

2009-06-01

429

Optimization of soft magnetic properties in Fe-B and Fe-B-Si amorphous alloys obtained by melt spinning method  

International Nuclear Information System (INIS)

In the present paper the progress of optimization of soft magnetic properties have been studied by applying different experimental techniques (magnetic measurements, electric measurements, X-ray analysis, and high-resolution electron microscopy observation). It has been shown that an increase in magnetic permeability after optimization annealing can be mainly attributed to annealing out of microvoids. (author)

2001-09-23

430

NASA Technical Reports Server - Magnetic forming coil design and ...  

Science.gov (United States)

Site Error There's a problem with your browser or settings. ...

435

Magnetic forming studies  

Science.gov (United States)

Elastodynamic approach to measuring stress-strain relationship of uniaxially stressed wire, and

1967-01-01

437

Magnetic excitations in amorphous ferromagnets  

Science.gov (United States)

Neutron scattering techniques have been used to measure the static structure and magnetic excitations in amorphous magnets. Sum rules and computer models are used to discuss the relationship between the static disorder and the shape of the excitation spectrum. Polarized beam measurements of chi''(Q,E) are compared to analytical theories and computer calculations for the magnetic excitations in amorphous ferromagnets.

1978-03-01

438

Magnetic electronic lenses, quadrupole and octupole for microsystem electron beam techniques  

International Nuclear Information System (INIS)

The MOS-technology allows to make tiny electronic lenses for multibeam electron systems. In the paper results of research and principles of designing of tiny magnetic electron lenses are submitted. Electronic lenses with a nonconventional configuration of tiny magnetic circuit and electronic lenses with coincident electric and magnetic fields in nonconventional tiny performance are considered

2006-09-01

442

Influence of rotation and magnetic field on the minimum mass of a main-sequence star  

Energy Technology Data Exchange (ETDEWEB)

The influence of rigid-body and differential rotation and of a fine-scale chaotic magnetic field and a poloidal magnetic field on the minimum mass of a main-sequence star is investigated. It is shown that rotation and a magnetic field with an energy equal to 10--20% of the star's gravitational energy increase the minimum mass of a main-sequence star by 1.5--2 times.

1980-11-01

459

A STUDY TO DETERMINE THE DEFORMATION ...  

Science.gov (United States)

... crystals and polycrystals. Nevertheless, explosive forming, magnetic forming, etc., are all high-strain-rate processes that ...

1963-04-01

460

A HELICAL MAGNET DESIGN FOR RHIC.  

Energy Technology Data Exchange (ETDEWEB)

Helical dipole magnets are required in a project for the Relativistic Heavy Ion Collider (RHIC) to control and preserve the beam polarization in order to allow the collision of polarized proton beams. Specifications are for low current superconducting magnets with a 100 mm coil aperture and a 4 Tesla field in which the field rotates 360 degrees over a distance of 2.4 meters. A magnet meeting the requirements has been developed that uses a small diameter cable wound into helical grooves machined into a thick-walled aluminum cylinder.

1997-05-12

461

Research and development on inhalation toxicologic evaluation of red phosphorus/butyl rubber combustion products  

Energy Technology Data Exchange (ETDEWEB)

Combinations of exposure concentrations, durations and frequencies were tested in four-week inhalation exposures followed by two weeks of recovery to define the interactive effects of these variables on biologic responses and to select the most-sensitive biologic response parameters for the subsequent subchronic studies. Response surface modeling was used for the experimental design and statistical analysis of the data. Results of preliminary testing suggested that exposure duration and frequency did not have major effects. Subsequently, male and female Sprague-Dawley rats were exposed in separate studies to RP/BR aerosols ranging from 0.40 to 1.20 mg/1 or to filtered air for 2.25 hr/day on four days/week for four weeks. Test-atmosphere monitoring data demonstrated that aerosol concentrations were consistently within 4% of the target values and mean particle size ranged from 0.44-0.64 ..mu..m with mean sigma g's of 1.66-1.97. During ...

1984-12-01

462

Reaction cross-section and reduced strong absorption radius measurements of neutron-rich nuclei in the vicinity of closed shells N=20 and N=28  

Energy Technology Data Exchange (ETDEWEB)

The energy-integrated reaction cross-sections of several neutron-rich nuclei ({sup 17-22}N, {sup 19-24}O, {sup 21-27}F, {sup 23-30}Ne, {sup 26-33}Na, {sup 28-35}Mg, {sup 31-38}Al, {sup 33-40}Si, {sup 36-42}P, {sup 39-44}S, {sup 42-45}Cl, {sup 45,46}Ar), measured at intermediate energy (30-65 A-bar MeV), via direct method, are presented. Silicon detectors have been used as the active target as well as for particles identification. The reduced strong absorption radii r{sub 0}{sup 2} are extracted and compared to the data available from the literature. New measurements for 19 nuclei ({sup 27}F, {sup 27,30}Ne, {sup 33}Na, {sup 28,34-35}Mg, {sup 36-38}Al, {sup 38-40}Si, {sup 41-42}P, {sup 42-44}S, {sup 45}Cl) are revealed. From the study of the isospin dependence of the reduced strong absorption radius, a new quadratic parameterisation of the nuclear radii in the closed shell regions N=8 and N=28, is proposed. According to this parameterisation, the ...

2006-12-11

463

Evaluation of Beta-Absorbed Fractions in a Mouse Model for 90Y, 188Re, 166Ho, 149Pm, 64Cu, and 177Lu Radionuclides  

Energy Technology Data Exchange (ETDEWEB)

Several short-lived, high-energy beta emitters are being proposed as the radionuclide components for molecular-targeted potential cancer therapeutic agents. The laboratory mice used to determine the efficacy of these new agents have organs that are relatively small compared to the ranges of these high-energy particles. The dosimetry model developed by Hui et al. was extended to provide realistic beta-dose estimates for organs in mice that received therapeutic radiopharmaceuticals containing 90Y, 188Re, 166Ho, 149Pm, 64Cu, and 177 Lu. Major organs in this model included the liver, spleen, kidneys, lungs, heart, stomach, small and large bowel, thyroid, pancreas, bone, marrow, carcass, and a 0.025-g tumor. The study as reported in this paper verifies their results for 90Y and extends them by using their organ geometry factors combined with newly calculated organ self-absorbed fractions from PEREGRINE and MCNP. PEREGRINE and MCNP agree to within 8% ...

2005-08-01

464

Activation cross sections of deuteron-induced nuclear reactions on hafnium  

International Nuclear Information System (INIS)

Experimental excitation functions for deuteron-induced reactions up to 20 MeV on high purity natural hafnium were measured with the activation method using a stacked foil irradiation technique. Metallic hafnium foils with thickness of 10 #mu#m were stacked together with 50 #mu#m thick aluminium and 12 #mu#m thick titanium foils. The aluminium foils served as energy absorber while the titanium foils were used to monitor the energy and intensity of the bombarding deuteron beam. From a detailed remeasurement of the complete excitation function of the "n"a"tTi(d,x)"4"8V monitor reaction it was possible to adopt the proper incident energy and beam intensity by comparing the results with the recommended values. High resolution off-line gamma-ray spectrometry was applied to assess the activity of each foil. From the measured activity independent and/or cumulative elemental or isotopic cross section data for production of Ta, Hf and Lu radioisotopes by (d,x) reactions were determined. No ...

2010-11-15

465

Magnetocaloric and magnetoresistance studies of GdPd{sub 2}Si  

Energy Technology Data Exchange (ETDEWEB)

The compound GdPd{sub 2}Si, which is reported to order antiferromagnetically at 13 K, has been investigated by heat capacity and electrical resistivity measurement in the presence of external magnetic fields. In contrast to an earlier report, the zero-field heat capacity and resistivity data indicate two magnetic transitions at 13 and 17 K. The external magnetic field substantially influences the resistivity and heat capacity of the compound around the magnetic ordering temperature. The magnetocaloric effect, which is calculated from in-field heat capacity data, is quite large around the magnetic transition temperature. The magnetoresistance is also large near the magnetic ordering temperature. The metamagnetic transition is observed for 10 kOe magnetic field both in magnetocaloric and in magnetoresistance data. The metamagnetic transition ...

2001-01-22

466

Magnetocaloric and magnetoresistance studies of GdPd_2Si  

International Nuclear Information System (INIS)

The compound GdPd_2Si, which is reported to order antiferromagnetically at 13 K, has been investigated by heat capacity and electrical resistivity measurement in the presence of external magnetic fields. In contrast to an earlier report, the zero-field heat capacity and resistivity data indicate two magnetic transitions at 13 and 17 K. The external magnetic field substantially influences the resistivity and heat capacity of the compound around the magnetic ordering temperature. The magnetocaloric effect, which is calculated from in-field heat capacity data, is quite large around the magnetic transition temperature. The magnetoresistance is also large near the magnetic ordering temperature. The metamagnetic transition is observed for 10 kOe magnetic field both in magnetocaloric and in magnetoresistance data. The metamagnetic transition ...

2001-01-22

467

Magnetic separation anxiety  

International Nuclear Information System (INIS)

This paper reports that only a few years ago superconducting magnetic separation was viewed as the next major market for superconducting magnets. The first commercial units had been installed, worked flawlessly, and demonstrated real economic viability. The potential market was seen as quite large, and many people believed that superconducting magnetic separation would soon show the same rapid growth that MRI had demonstrated after its initial success. These hopes even prompted IGC, one of the top MRI magnet builders, to form a separate division devoted to magnetic separation. Despite the existence of Magstream, IGC has not been overly active in the market. As a technology that has applications from the clay on the Earth to the soil on the moon, superconducting magnetic separation has yet to become widely used.

1992-01-01

468

High-mode-number ballooning modes in a heliotron/torsatron system: 1, Local magnetic shear  

Energy Technology Data Exchange (ETDEWEB)

The characteristics of the local magnetic shear, a quantity associated with high-mode-number ballooning mode stability, are considered in heliotron/torsatron devices that have a large Shafranov shift. The local magnetic shear is shown to vanish even in the stellarator-like region in which the global magnetic shear is positive. The reason for this is that the degree of the local compression of the poloidal magnetic field on the outer side of the torus, which maintains the toroidal force balance, is reduced in the stellarator-like region of global magnetic shear because the global rotational transform in heliotron/torsatron systems is a radially increasing function. This vanishing of the local magnetic shear is a universal property in heliotron/torsatron systems with a large Shafranov shift since it results from toroidal force balance in the stellarator-like ...

1996-05-01

469

Effect of the induced magnetic field on peristaltic flow of a couple stress fluid  

Science.gov (United States)

We have analyzed the MHD flow of a conducting couple stress fluid in a slit channel with rhythmically contracting walls. In this analysis we are taking into account the induced magnetic field. Analytical expressions for the stream function, the magnetic force function, the axial pressure gradient, the axial induced magnetic field and the distribution of the current density across the channel are obtained using long wavelength approximation. The results for the pressure rise, the frictional force per wave length, the axial induced magnetic field and distribution of the current density across the channel have been computed numerically and the results were studied for various values of the physical parameters of interest, such as the couple stress parameter ?, the Hartmann number M, the magnetic Reynolds number R and the time averaged mean flow rate ?. Contour plots for the stream and ...

2008-06-01

470

Eddy current probe development based on a magnetic sensor array; Developpement d'un imageur magnetique pour le controle non destructif par courants de Foucault  

Energy Technology Data Exchange (ETDEWEB)

This research deals with in the study of the use of innovating magnetic sensors in eddy current non destructive inspection. The author reports an analysis survey of magnetic sensor performances. This survey enables the selection of magnetic sensor technologies used in non destructive inspection. He presents the state-of-the-art of eddy current probes exploiting the qualities of innovating magnetic sensors, and describes the methods enabling the use of these magnetic sensors in non destructive testing. Two main applications of innovating magnetic sensors are identified: the detection of very small defects by means of magneto-resistive sensors, and the detection of deep defects by means of giant magneto-impedances. Based on the use of modelling, optimization, signal processing tools, probes are manufactured for these both applications.

2007-06-15

471

On the temperature dependence of the magnetic excitations  

International Nuclear Information System (INIS)

We compare experimental data for temperature dependence of the magnetic order parameter and the magnetic excitations (spin waves) in materials with a quenched orbital moment and a well-defined spin quantum number. It is observed that the thermal decrease of the two quantities proceeds according to the same analytical function of the type y(T)=1-cT"#epsilon# with an identical exponent #epsilon#. This power function applies not only asymptotically for T->0 but holds over a wide temperature range. The exponent #epsilon# is universal, i.e. independent of spin order type and lattice symmetry and depends only on the dimensionality of the relevant interactions and on whether the spin quantum number is integer or half-integer. The different T"#epsilon# functions are identified as representations of stable universality classes. The fact that order parameter and magnetic excitations follow the same T"#epsilon# function shows that ...

2005-07-15

472

Theory of zwitterionic molecular-based organic magnets  

British Library Electronic Table of Contents (United Kingdom)

We describe a class of organic molecular magnets based on zwitterionic molecules (betaine derivatives) possessing donor, p bridge, and acceptor groups. Using extensive electronic structure calculations we show the electronic ground-state in these systems is magnetic. In addition, we show that the large energy differences computed for the various magnetic states indicate a high Neel temperature. The quantum mechanical nature of the magnetic properties originates from the conjugated p bridge (only p electrons) in cooperation with the molecular donor-acceptor character. The exchange interactions between electron spin are strong, local, and independent on the length of the p bridge.

2011-01-01

473

Occurrence of magnetism in superconductors  

Science.gov (United States)

We discuss how magnetic phenomena affect superconductivity in simple metals, transition metals and alloys thereof, and dilute Rare-Earth alloys. It is shown both qualitatively and quantitatively that superconductors are sensitive probes for studying itinerant spin excitations, local spin excitations associated with nearly magnetic impurities, the effect of the atomic environment on the stability of local magnetic moments, and the nature of the spin order in Rare-Earth alloys. Also, we discuss how magnetic impurities can be used to study the electronic configuration which is responsible for superconductivity in Laves-phase crystals like A-15 compounds and ..beta..-W crystals, for example.

1970-12-14

474

Magnetic response of ultrathin Fe on MgO: A polarized neutron reflectometry study  

Energy Technology Data Exchange (ETDEWEB)

The magnetization of ultrathin bcc Fe films (two and three monolayers) on MgO was measured and compared with the behavior predicted for a two-dimensional ferromagnet. The experiment indicated that no hysteresis was present in the magnetization. Instead, the magnetization at low temperature was affected by a marked field cooling effect. These observations lead to the conclusion that films of Fe on MgO of such thickness exhibit superparamagnetic behavior as if they were not entirely continuous. In contrast, films thicker than five monolayers exhibit a magnetic response close to that of bulk iron.

1994-11-15

475

Magnetic properties of glasses from geothite industrial wastes recycling (FeOOH)  

International Nuclear Information System (INIS)

It has been carried out the magnetic properties determination for high iron oxide content glasses series obtained from a geothite red mud waste from the zinc hydrometallurgy and dolomite and glass cullet as main raw materials. It has been determined the magnetic susceptibility and magnetization values for the glasses here investigated. The results suggest that the magnetic behaviour are depending on the glass chemical composition, so that glasses can be differently classified like ferrimagnetic, ferromagnetic, superparamagnetic and paramagnetic. (Author) 6 refs.

476

Magnetic fluctuations in paramagnetic Mn{sub 0.81}Ni{sub 0.19}  

Energy Technology Data Exchange (ETDEWEB)

Magnetic fluctuations present in the paramagnetic Mn{sub 0.81}Ni{sub 0.19} system have been investigated by measuring inelastic magnetic neutron scattering from a single crystal at temperatures of 450, 585 and 700 K. Antiferromagnetic correlations are observed to be present at all the temperatures studied. The spectral width of the magnetic scattering has been observed to increase with temperature, while the spatial range of the magnetic correlations is seen to decrease as the temperature is raised. The wave-vector-dependent susceptibility is found to follow a Curie-Weiss law near the (1 0 0) position, in agreement with theoretical predictions.

2006-11-15

477

Hydromagnetic rotational braking of magnetic stars  

International Nuclear Information System (INIS)

It is suggested that the magnetic Ap stars can be rotationally decelerated to long periods by the braking action of the associated magnetic field on time scales of order 10"7--10"1"0 years depending on whether the star's dipole field is aligned perpendicular or parallel to the rotation axis. Rotation includes a toroidal magnetic field in the plasma surrounding a star, and the accompanying magnetic stresses produce a net torque acting to despin the star. These results indicate that it is not necessary to postulate mass loss or mass accretion for this purely hydromagnetic braking effect.

478

Correlation between Magnetic Field Quality and mechanical components of the Large Hadron Collider Main Dipoles  

CERN Document Server

The homogeneity of the magnetic field in the LHC dipoles strongly depends on the correct position of the superconducting cables: this is related to the quality of the dipole components, such as the dimension of the coil spacers (copper wedges), of the cable and of the collars. The performance in operational conditions is also affected by the magnetization of the cables. In this work, we analyse the measurements of these quantities during the production of the 1276 LHC dipoles, their trends, and the relation to the measured magnetic field. A novel mtehod to locate electrical shorts based on the analysis of magnetic measurements is also presented, and applications to 15 dipoles reascued during the production is given.

2006-01-01

479

U of C site vies for new particle accelerator  

CERN Multimedia

"American dominance in the study and development of high-energy particle physics may be seriously compromised, according to a report issued by the National Academy of Sciences, unless efforts are made to ensure that the next high-energy particle accelerator - the International Linear Collider (ILC) - will be constructed in the U.S.

2006-01-01

480

Search for free quarks at PEP  

Energy Technology Data Exchange (ETDEWEB)

The results of a search for fractionally charged particles produced in e/sup +/e/sup -/ annihilation at 29 GeV/c/sup 2/ are discussed. Results from cosmic-ray searches for fractionally charged particles, tachyons, and massive particles using the same detector are also presented.

1982-01-01

481

Particle creation if a cosmic string snaps  

CERN Document Server

We calculate the Bogolubov coefficients for a metric which describes the snapping of a cosmic string. If we insist on a matching condition for all times {\\it and} a particle interpretation, we find no particle creation.

1994-01-01

482

Entropic effects in channel-facilitated transport: Inter-particle interactions break the flux symmetry  

UK PubMed Central (United Kingdom)

We analyze transport through conical channels due to the difference in particle concentration on the two sides of the membrane. Because of the detailed balance, fluxes of non-interacting particles...Full Text Available

2009-08-01

483

Characterization of Two Unique Cholesterol-Rich Lipid Particles Isolated from Human Atherosclerotic Lesions  

UK PubMed Central (United Kingdom)

The authors' laboratory, using histochemicalmethods, previously identified two types of cholesterol-containing lipid particles in the extracellular spaces of human atherosclerotic lesions, one particle...Full Text Available

1990-01-01

484

A new method for quantifiable and controlled dosage of particulate matter for in vitro studies: the electrostatic particulate dosage and exposure system (EPDExS).  

Science.gov (United States)

An exposure chamber is described for the quantifiable addition of fine and ultrafine aerosol particulate matter directly to cells and used to demonstrate the in vitro cytotoxicity of fine 1,4-naphthoquinone particles to murine lung epithelial cells. The electrostatic particulate dosage and exposure system (EPDExS) operates on the principle of electrostatic precipitation and is shown to deposit fine and ultrafine aerosol particles directly to cells with 100% efficiency for particle diameters in the range of 40-530nm. This range is not limited by the EPDExS, but rather by the aerosolization method used for this study. Numbers of particles deposited onto the cells are counted with a condensation particle counter, negating any need to calculate or estimate particle exposure. The process of particle introduction, assessed using Trypan blue dye ...

2008-06-08

485

How the Performance of a Superconducting Magnet is affected by theConnection between a small cooler and the Magnet  

Energy Technology Data Exchange (ETDEWEB)

As low temperature cryocoolers become more frequently used to cool superconducting magnets, it becomes increasingly apparent that the connection between the cooler and the magnet has an effect on the design and performance of the magnet. In general, the use of small coolers can be considered in two different temperature ranges; (1) from 3.8 to 4.8 K for magnet fabricated with LTS conductor and (2) from 18 to 35 K for magnets fabricated using HTS conductor. In general, both temperature ranges call for the use of a two-stage cooler. The best method for connecting a cooler to the magnet depends on a number of factors. The factors include: (1) whether the cooler must be used to cool down the magnet from room temperature, (2) whether the magnet must have one or more reservoirs of liquid cryogen to keep the ...

2005-09-08

486

Wear particle equilibrium measurements and their significance  

Energy Technology Data Exchange (ETDEWEB)

Ferrography is a technique for isolating wear particle debris from lubricating and hydraulic oils, the presence of which carry with them a history of the wear processes in the machine. Thus, the technique has fundamental applications in machine condition monitoring and failure prevention. The wear particles are significant in the metal types that are present in the particle distribution as an indication of the wearing machine components and in the particle size distribution and morphology which indicates the severity of wear in the system. In this paper, the fundamental principles which describe the working of the ferrograph, concentrating on the working of the on-line ferrograph are discussed. The significance of equilibrium particle concentration in the oil system and its measurement using the ferrograph are also discussed.

1980-11-01

487

Thermal performance and design of a solid particle cavity receiver  

Energy Technology Data Exchange (ETDEWEB)

A model for energy transport in a solid particle cavity receiver is developed and applied to the design and analysis of a receiver for the Central Receiver Test Facility (CRTF), Albuquerque, New Mexico. The model gives thermal performance results - including particle temperatures, cavity efficiencies, and wall temperatures - which directly affect the economic and technical feasibility of a solid particle receiver. In addition, design criteria relevant to the configuration of a solid particle cavity receiver are developed. Results for CRTF indicate that at design conditions particle temperatures will exceed 1200/sup 0/K with cavity efficiencies on the order of 75%.

1985-04-01

488

Variation in the Definition of Clinical Target Volumes for Pelvic Nodal Conformal Radiation Therapy for Prostate Cancer  

UK PubMed Central (United Kingdom)

PurposeWe conducted a comparative study of Clinical Target Volume (CTV) definition of pelvic lymph nodes by multiple GU radiation oncologists looking at the levels...Full Text Available

2009-06-01

489

Targeted Deletion of Somatotroph Insulin-Like Growth Factor-I Signaling in a Cell-Specific Knockout Mouse Model  

UK PubMed Central (United Kingdom)

The role of IGF-I in the negative regulation of GH expression and release is demonstrated by in vitro and in vivo models; however, the targets and mechanisms of IGF-I...Full Text Available

2010-05-01

490

Specific genetic modifications of domestic animals by gene targeting and animal cloning  

UK PubMed Central (United Kingdom)

The technology of gene targeting through homologous recombination has been extremely useful for elucidating gene functions in mice. The application of this technology was thought impossible in the large...Full Text Available

491

National Newborn Screening Status Reports  

Science.gov (United States)

... detected (and reported) as a by-product of MRM screening (MS/MS) targeted by Law or Rule ... detected (and reported) as a by-product of MRM screening (MS/MS) targeted by Law or Rule ...

492

How DNA coiling enhances target localization by proteins  

UK PubMed Central (United Kingdom)

Many genetic processes depend on proteins interacting with specific sequences on DNA. Despite the large excess of nonspecific DNA in the cell, proteins can locate their targets rapidly. After initial...Full Text Available

2008-10-14

493

Evolutionary conservation of a microbody targeting signal that targets proteins to peroxisomes, glyoxysomes, and glycosomes  

UK PubMed Central (United Kingdom)

Peroxisomes, glyoxysomes, glycosomes, and hydrogenosomes have each been classified as microbodies, i.e., subcellular organelles with an electron-dense matrix that is bound by a single membrane. We investigated...Full Text Available

1991-09-01

494

Efficient use of accessibility in microRNA target prediction  

UK PubMed Central (United Kingdom)

Considering accessibility of the 3′UTR is believed to increase the precision of microRNA target predictions. We show that, contrary to common belief, ranking by the hybridization energy or by...Full Text Available

2011-01-01

495

Concurrent schedule control of human visual target fixations1  

UK PubMed Central (United Kingdom)

Operant conditioning techniques were applied to the study of how target fixations are controlled by the probability of signal occurrence. In a standard vigilance setting, gaze at three illuminable...Full Text Available

1973-11-01

496

Biphasic targeting and cleavage furrow ingression directed by the tail of a myosin II  

UK PubMed Central (United Kingdom)

Cytokinesis in animal and fungal cells utilizes a contractile actomyosin ring (AMR). However, how myosin II is targeted to the division site and promotes AMR assembly, and how the AMR coordinates with...Full Text Available

2010-12-27