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Sample records for solenoidal magnetic field

  1. Solenoid magnetic fields calculated from superposed semi-infinite solenoids

    NASA Technical Reports Server (NTRS)

    Brown, G. V.; Flax, L.

    1966-01-01

    Calculation of a thick solenoid coils magnetic field components is made by a superposition of the fields produced by four solenoids of infinite length and zero inner radius. The field produced by this semi-infinite solenoid is dependent on only two variables, the radial and axial field point coordinates.

  2. MICE Spectrometer Solenoid Magnetic Field Measurements

    SciTech Connect

    Leonova, M.

    2013-09-01

    The Muon Ionization Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with an absolute measurement accuracy of 0.1%. To measure emittances, MICE uses two solenoidal spectrometers, with Solenoid magnets designed to have 4 T fields, uniform at 3 per mil level in the tracking volumes. Magnetic field measurements of the Spectrometer Solenoid magnet SS2, and analysis of coil parameters for input into magnet models will be discussed.

  3. Simulation of Electron Cloud Multipacting in Solenoidal Magnetic Field

    SciTech Connect

    Novokhatski, A

    2004-01-27

    A simulation algorithm is based on a numerical solution of the Vlasov equation for the distribution function of an electron cloud density in a cylindrical vacuum chamber with solenoidal magnetic field. The algorithm takes into consideration space charge effects. This approach improves the simulation of multipacting effects as it is free of statistical fluctuations. Simulation studies were carried for the SLAC B-factory vacuum chamber for different bunch patterns and solenoidal field strength. Space charge and the magnetic field limit the maximum density of the electron cloud. Magnetic resonant damping of multipacting was found in special cases of positron beam parameters and magnetic field amplitude.

  4. Effect of solenoidal magnetic field on drifting laser plasma

    NASA Astrophysics Data System (ADS)

    Takahashi, Kazumasa; Okamura, Masahiro; Sekine, Megumi; Cushing, Eric; Jandovitz, Peter

    2013-04-01

    An ion source for accelerators requires to provide a stable waveform with a certain pulse length appropriate to the application. The pulse length of laser ion source is easy to control because it is expected to be proportional to plasma drifting distance. However, current density decay is proportional to the cube of the drifting distance, so large current loss will occur under unconfined drift. We investigated the stability and current decay of a Nd:YAG laser generated copper plasma confined by a solenoidal field using a Faraday cup to measure the current waveform. It was found that the plasma was unstable at certain magnetic field strengths, so a baffle was introduced to limit the plasma diameter at injection and improve the stability. Magnetic field, solenoid length, and plasma diameter were varied in order to find the conditions that minimize current decay and maximize stability.

  5. Integration of RFQ beam coolers and solenoidal magnetic fields

    NASA Astrophysics Data System (ADS)

    Cavenago, M.; Romé, M.; Maggiore, M.; Porcellato, A. M.; Maero, G.; Chiurlotto, F.; Comunian, M.; Galatà, A.; Cavaliere, F.

    2016-02-01

    Electromagnetic traps are a flexible and powerful method of controlling particle beams, possibly of exotic nuclei, with cooling (of energy spread and transverse oscillations) provided by collisions with light gases as in the Radio Frequency Quadrupole Cooler (RFQC). A RFQC prototype can be placed inside the existing Eltrap solenoid, capable of providing a magnetic flux density component Bz up to 0.2 T, where z is the solenoid axis. Confinement in the transverse plane is provided both by Bz and the rf voltage Vrf (up to 1 kV at few MHz). Transport is provided by a static electric field Ez (order of 100 V/m), while gas collisions (say He at 1 Pa, to be maintained by differential pumping) provide cooling or heating depending on Vrf. The beamline design and the major parameters Vrf, Bz (which affect the beam transmission optimization) are here reported, with a brief description of the experimental setup.

  6. Integration of RFQ beam coolers and solenoidal magnetic fields.

    PubMed

    Cavenago, M; Romé, M; Maggiore, M; Porcellato, A M; Maero, G; Chiurlotto, F; Comunian, M; Galatà, A; Cavaliere, F

    2016-02-01

    Electromagnetic traps are a flexible and powerful method of controlling particle beams, possibly of exotic nuclei, with cooling (of energy spread and transverse oscillations) provided by collisions with light gases as in the Radio Frequency Quadrupole Cooler (RFQC). A RFQC prototype can be placed inside the existing Eltrap solenoid, capable of providing a magnetic flux density component Bz up to 0.2 T, where z is the solenoid axis. Confinement in the transverse plane is provided both by Bz and the rf voltage Vrf (up to 1 kV at few MHz). Transport is provided by a static electric field Ez (order of 100 V/m), while gas collisions (say He at 1 Pa, to be maintained by differential pumping) provide cooling or heating depending on Vrf. The beamline design and the major parameters Vrf, Bz (which affect the beam transmission optimization) are here reported, with a brief description of the experimental setup. PMID:26932057

  7. The external magnetic field created by the superposition of identical parallel finite solenoids

    NASA Astrophysics Data System (ADS)

    Lim, Melody Xuan; Greenside, Henry

    2016-08-01

    We use superposition and numerical methods to show that the external magnetic field generated by parallel identical solenoids can be nearly uniform and substantial, even when the solenoids have lengths that are large compared to their radii. We examine both a ring of solenoids and a large hexagonal array of solenoids. In both cases, we discuss how the magnitude and uniformity of the external field depend on the length of and the spacing between the solenoids. We also discuss some novel properties of a single solenoid, e.g., that even for short solenoids the energy stored in the internal magnetic field exceeds the energy stored in the spatially infinite external magnetic field. These results should be broadly interesting to undergraduates learning about electricity and magnetism.

  8. Using Experiment and Computer Modeling to Determine the Off-Axis Magnetic Field of a Solenoid

    ERIC Educational Resources Information Center

    Lietor-Santos, Juan Jose

    2014-01-01

    The study of the ideal solenoid is a common topic among introductory-based physics textbooks and a typical current arrangement in laboratory hands-on experiences where the magnetic field inside a solenoid is determined at different currents and at different distances from its center using a magnetic probe. It additionally provides a very simple…

  9. Behavior of moving plasma in solenoidal magnetic field in a laser ion source.

    PubMed

    Ikeda, S; Takahashi, K; Okamura, M; Horioka, K

    2016-02-01

    In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons. PMID:26931973

  10. Behavior of moving plasma in solenoidal magnetic field in a laser ion source

    NASA Astrophysics Data System (ADS)

    Ikeda, S.; Takahashi, K.; Okamura, M.; Horioka, K.

    2016-02-01

    In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons.

  11. Magnetic Field, Force, and Inductance Computations for an Axially Symmetric Solenoid

    NASA Technical Reports Server (NTRS)

    Lane, John E.; Youngquist, Robert C.; Immer, Christopher D.; Simpson, James C.

    2001-01-01

    The pumping of liquid oxygen (LOX) by magnetic fields (B field), using an array of electromagnets, is a current topic of research and development at Kennedy Space Center, FL. Oxygen is paramagnetic so that LOX, like a ferrofluid, can be forced in the direction of a B field gradient. It is well known that liquid oxygen has a sufficient magnetic susceptibility that a strong magnetic gradient can lift it in the earth's gravitational field. It has been proposed that this phenomenon can be utilized in transporting (i.e., pumping) LOX not only on earth, but on Mars and in the weightlessness of space. In order to design and evaluate such a magnetic pumping system, it is essential to compute the magnetic and force fields, as well as inductance, of various types of electromagnets (solenoids). In this application, it is assumed that the solenoids are air wrapped, and that the current is essentially time independent.

  12. Precise Measurements of a Magnetic Field at the Solenoids for Low Energy Coolers

    SciTech Connect

    Bocharov, V.; Bubley, A.; Konstantinov, S.; Panasyuk, V.; Parkhomchuk, V.

    2006-03-20

    Description of equipment developed at BINP SB RAS for precision solenoid magnetic field measurement is presented in the paper. Transversal field components are measured by small compass-based sensor during its motion along the field line. The sensor sensitivity is a few tenth parts of mG and is limited in this range by external noise sources only. Scope of the device application is illustrated by results obtained at BINP during tests of cooling solenoids for electron coolers built at the Institute recently.

  13. The Magnetic Field inside a Long Solenoid--A New Approach

    ERIC Educational Resources Information Center

    Andrews, David; Carlton, Kevin; Lisgarten, David

    2010-01-01

    This article describes a technique for measuring the magnetic field inside a long solenoid using computer data logging. This is a new approach to a standard student practical. The design and construction of the sensors is described; they significantly reduce the cost of the apparatus. The approach of the practical is for the students to…

  14. Cylindrical magnets and ideal solenoids

    NASA Astrophysics Data System (ADS)

    Derby, Norman; Olbert, Stanislaw

    2010-03-01

    Both wire-wound solenoids and cylindrical magnets can be approximated as ideal azimuthally symmetric solenoids. We present an exact solution for the magnetic field of an ideal solenoid in an easy to use form. The field is expressed in terms of a single function that can be rapidly computed by means of a compact efficient algorithm, which can be coded as an add-in function to a spreadsheet, making field calculations accessible to introductory students. These expressions are not only accurate but are also as fast as most approximate expressions. We demonstrate their utility by simulating the dropping of a cylindrical magnet through a nonmagnetic conducting tube and comparing the calculation with data obtained from experiments suitable for an undergraduate laboratory.

  15. Effect of high solenoidal magnetic fields on breakdown voltages of high vacuum 805 MHz cavities

    SciTech Connect

    Moretti, A.; Bross, A.; Geer, S.; Qian, Z.; Norem, J.; Li, D.; Zisman, M.; Torun, Y.; Rimmer, R.; Errede, D.; /Illinois U., Urbana

    2005-10-01

    There is an on going international collaboration studying the feasibility and cost of building a muon collider or neutrino factory [1,2]. An important aspect of this study is the full understanding of ionization cooling of muons by many orders of magnitude for the collider case. An important muon ionization cooling experiment, MICE [3], has been proposed to demonstrate and validate the technology that could be used for cooling. Ionization cooling is accomplished by passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF Cavities within a multi-Tesla solenoidal field. To determine the effect of very large solenoidal magnetic fields on the generation of dark current, x-rays and on the breakdown voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station and a large warm bore 5 T solenoidal superconducting magnet containing a pill box type cavity with thin removable window apertures. This system allows dark current and breakdown studies of different window configurations and materials. The results of this study will be presented. The study has shown that the peak achievable accelerating gradient is reduced by a factor greater than 2 when solenoidal field of greater than 2 T are applied to the cavity.

  16. Magnetic latching solenoid

    DOEpatents

    Marts, Donna J.; Richardson, John G.; Albano, Richard K.; Morrison, Jr., John L.

    1995-01-01

    This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized.

  17. Magnetic latching solenoid

    DOEpatents

    Marts, D.J.; Richardson, J.G.; Albano, R.K.; Morrison, J.L. Jr.

    1995-11-28

    This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized. 2 figs.

  18. SolCalc: A Suite for the Calculation and the Display of Magnetic Fields Generated by Solenoid Systems

    SciTech Connect

    Lopes, M. L.

    2014-07-01

    SolCalc is a software suite that computes and displays magnetic fields generated by a three dimensional (3D) solenoid system. Examples of such systems are the Mu2e magnet system and Helical Solenoids for muon cooling systems. SolCalc was originally coded in Matlab, and later upgraded to a compiled version (called MEX) to improve solving speed. Matlab was chosen because its graphical capabilities represent an attractive feature over other computer languages. Solenoid geometries can be created using any text editor or spread sheets and can be displayed dynamically in 3D. Fields are computed from any given list of coordinates. The field distribution on the surfaces of the coils can be displayed as well. SolCalc was benchmarked against a well-known commercial software for speed and accuracy and the results compared favorably.

  19. Charge and Current Neutralization of an Ion-Beam Pulse Propagating in a Background Plasma along a Solenoidal Magnetic Field

    SciTech Connect

    Kaganovich, I. D.; Startsev, E. A.; Sefkow, A. B.; Davidson, R. C.

    2007-12-07

    The analytical studies show that the application of a small solenoidal magnetic field can drastically change the self-magnetic and self-electric fields of the beam pulse propagating in a background plasma. Theory predicts that when {omega}{sub ce}{approx}{omega}{sub pe}{beta}{sub b}, where {omega}{sub ce} is the electron gyrofrequency, {omega}{sub pe} is the electron plasma frequency, and {beta}{sub b} is the ion-beam velocity relative to the speed of light, there is a sizable enhancement of the self-electric and self-magnetic fields due to the dynamo effect. Furthermore, the combined ion-beam-plasma system acts as a paramagnetic medium; i.e., the solenoidal magnetic field inside the beam pulse is enhanced.

  20. Controlling charge and current neutralization of an ion beam pulse in a background plasma by application of a solenoidal magnetic field: Weak magnetic field limit

    SciTech Connect

    Kaganovich, I. D.; Startsev, E. A.; Sefkow, A. B.; Davidson, R. C.

    2008-10-15

    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 influence the self-electric and self-magnetic fields when {omega}{sub ce} > or approx. {omega}{sub pe}{beta}{sub b}, where {omega}{sub ce}=eB/m{sub e}c is the electron gyrofrequency, {omega}{sub pe} is the electron plasma frequency, and {beta}{sub b}=V{sub b}/c is the ion beam velocity relative to the speed of light. This condition typically holds for relatively small magnetic fields (about 100 G). Analytical formulas are derived for the effective radial force acting on the beam ions, which can be used to minimize beam pinching. The results of analytic theory have been verified by comparison with the simulation results obtained from two particle-in-cell codes, which show good agreement.

  1. 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

    SciTech Connect

    Kaganovich, I. D., Startsev, E. A., Sefkow, A. B., Davidson, R. C.

    2008-10-10

    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 ωce > ωpeβb, where ωce = eβ/mec is the electron gyrofrequency, ωpe is the electron plasma frequency, and βb = Vb/c is the ion beam velocity relative to the speed of light. This condition typically holds for relatively small magnetic fields (about 100G). Analytical formulas are derived for the effective radial force acting on the beam ions, which can be used to minimize beam pinching. The results of analytic theory have been verified by comparison with the simulation results obtained from two particle-in-cell codes, which show good agreement.

  2. Development of a MHD code satisfying solenoidal magnetic field condition and its application to Mercury's magnetosphere

    NASA Astrophysics Data System (ADS)

    Yagi, M.; Seki, K.; Matsumoto, Y.

    2007-12-01

    The MHD simulation is one of the powerful methods to understand global structure of the magnetosphere. However, in the Mercury's magnetosphere, kinetic effects of plasma might not be negligible because of its small scale. Statistical trajectory tracing of test particles is an important scheme to investigate the kinetic effects of particles. Previous studies by Delcourt et al. [2003; 2005] used analytical models of electric and magnetic fields that are obtained by rescaling the Earth's magnetosphere and calculated the motion of planetary sodium ions. While this approach is efficient to see the dynamics of heavy ions, resultant properties largely depend on the field models. In order to verify the particle dynamics in the more realistic global configuration of the Mercury's magnetosphere, a self-consistent electric and magnetic field configuration such as that obtained from MHD simulations is required. For studies of the kinetic effects, it is important that the resultant magnetic field (B) satisfies solenoidal condition, i.e., divB=0, to avoid artificial acceleration/deceleration. Aiming at global simulation of the Mercury's magnetosphere, we developed a MHD simulation code that automatically satisfies solenoidal condition for B. To implement the condition, we used vector potential (A) instead of magnetic field itself in the MHD equations. The usage of A automatically guaranteed divB=div(rotA)=0. For an accurate simulation of high Reynolds number magnetofluid, we adopted R-CIP algorithm [Yabe et al., 1991; Xiao et al., 1996] to solve the advection term in the simulation code. The non-advection terms are solved by 4th order Runge-Kutta method or 3rd order Adams-Moulton predictor-corrector method. The code assessment by comparison with previous simulations with TVD algorithm or analytical solutions shows reasonably good ability of energy and mass conservation, and description of MHD discontinuities. A remarkable feature of the new code with A is the precise description

  3. Photon production from the scattering of axions out of a solenoidal magnetic field

    SciTech Connect

    Guendelman, Eduardo I.; Shilon, Idan; Cantatore, Giovanni; Zioutas, Konstantin E-mail: silon@bgu.ac.il E-mail: Konstantin.Zioutas@cern.ch

    2010-06-01

    We calculate the total cross section for the production of photons from the scattering of axions by a strong inhomogeneous magnetic field in the form of a 2D δ-function, a cylindrical step function and a 2D Gaussian distribution, which can be approximately produced by a solenoidal current. The theoretical result is used to estimate the axion-photon conversion probability which could be expected in a reasonable experimental situation. Comparison between the 2D conversion probabilities for QCD inspired axions and those derived by applying the celebrated 1D calculation of the (inverse) coherent Primakoff effect is made using an averaging prescription procedure of the 1D case. We also consider scattering at a resonance E{sub axion} ∼ m{sub axion}, which corresponds to the scattering from a δ-function and gives the most enhanced results. Finally, we analyze the results of this work in the astrophysical extension to suggest a way in which they may be directed to a solution to some basic solar physics problems and, in particular, the coronal heating problem.

  4. The superconducting solenoid magnets for MICE

    SciTech Connect

    Green, Michael A.

    2002-12-22

    The Muon Ionization Cooling Experiment (MICE) is a channel of superconducting solenoid magnets. The magnets in MICE are around the RF cavities, absorbers (liquid or solid) and the primary particle detectors [1], [2]. The MICE superconducting solenoid system consists of eighteen coils that are grouped in three types of magnet assemblies. The cooling channel consists of two complete cell of an SFOFO cooling channel. Each cell consists of a focusing coil pair around an absorber and a coupling coil around a RF cavity that re-accelerates the muons to their original momentum. At the ends of the experiment are uniform field solenoids for the particle detectors and a set of matching coils used to match the muon beam to the cooling cells. Three absorbers are used instead of two in order to shield the detectors from dark currents generated by the RF cavities at high operating acceleration gradients.

  5. Bent Solenoids with Superimposed Dipole Fields

    SciTech Connect

    Meinke, Rainer, B.; Goodzeit, Carl, L.

    2000-03-21

    A conceptual design and manufacturing technique were developed for a superconducting bent solenoid magnet with a superimposed dipole field that would be used as a dispersion device in the cooling channel of a future Muon Collider. The considered bent solenoid is equivalent to a 180° section of a toroid with a major radius of ~610 mm and a coil aperture of ~416 mm. The required field components of this magnet are 4 tesla for the solenoid field and 1 tesla for the superimposed dipole field. A magnet of this size and shape, operating at these field levels, has to sustain large Lorentz forces resulting in a maximum magnetic pressure of about 2,000 psi. A flexible round mini-cable with 37 strands of Cu-NbTi was selected as the superconductor. Detailed magnetic analysis showed that it is possible to obtain the required superimposed dipole field by tilting the winding planes of the solenoid by ~25°. A complete structural analysis of the coil support system and the helium containment vessel under thermal, pressure, and Lorentz force loads was carried out using 3D finite element models of the structures. The main technical issues were studied and solutions were worked out so that a highly reliable magnet of this type can be produced at an affordable cost.

  6. Superconducting solenoid model magnet test results

    SciTech Connect

    Carcagno, R.; Dimarco, J.; Feher, S.; Ginsburg, C.M.; Hess, C.; Kashikhin, V.V.; Orris, D.F.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; /Fermilab

    2006-08-01

    Superconducting solenoid magnets suitable for the room temperature front end of the Fermilab High Intensity Neutrino Source (formerly known as Proton Driver), an 8 GeV superconducting H- linac, have been designed and fabricated at Fermilab, and tested in the Fermilab Magnet Test Facility. We report here results of studies on the first model magnets in this program, including the mechanical properties during fabrication and testing in liquid helium at 4.2 K, quench performance, and magnetic field measurements. We also describe new test facility systems and instrumentation that have been developed to accomplish these tests.

  7. Enhanced collective focusing of intense neutralized ion beam pulses in the presence of weak solenoidal magnetic fields

    SciTech Connect

    Dorf, Mikhail A.; Davidson, Ronald C.; Kaganovich, Igor D.; Startsev, Edward A.

    2012-05-31

    In this study, the design of ion drivers for warm dense matter and high energy density physics applications and heavy ion fusion involves transverse focusing and longitudinal compression of intense ion beams to a small spot size on the target. To facilitate the process, the compression occurs in a long drift section filled with a dense background plasma, which neutralizes the intense beam self-fields. Typically, the ion bunch charge is better neutralized than its current, and as a result a net self-pinching (magnetic) force is produced. The self-pinching effect is of particular practical importance, and is used in various ion driver designs in order to control the transverse beam envelope. In the present work we demonstrate that this radial self-focusing force can be significantly enhanced if a weak (B~100 G) solenoidal magnetic field is applied inside the neutralized drift section, thus allowing for substantially improved transport. It is shown that in contrast to magnetic self-pinching, the enhanced collective self-focusing has a radial electric field component and occurs as a result of the overcompensation of the beam charge by plasmaelectrons, whereas the beam current becomes well-neutralized. As the beam leaves the neutralizing drift section, additional transverse focusing can be applied. For instance, in the neutralized drift compression experiments (NDCX) a strong (several Tesla) final focus solenoid is used for this purpose. In the present analysis we propose that the tight final focus in the NDCX experiments may possibly be achieved by using a much weaker (few hundred Gauss) magnetic lens, provided the ion beam carries an equal amount of co-moving neutralizing electrons from the preceding drift section into the lens. In this case the enhanced focusing is provided by the collective electrondynamics strongly affected by a weak applied magnetic field.

  8. Enhanced collective focusing of intense neutralized ion beam pulses in the presence of weak solenoidal magnetic fields

    SciTech Connect

    Dorf, Mikhail A.; Davidson, Ronald C.; Kaganovich, Igor D.; Startsev, Edward A.

    2012-05-15

    The design of ion drivers for warm dense matter and high energy density physics applications and heavy ion fusion involves transverse focusing and longitudinal compression of intense ion beams to a small spot size on the target. To facilitate the process, the compression occurs in a long drift section filled with a dense background plasma, which neutralizes the intense beam self-fields. Typically, the ion bunch charge is better neutralized than its current, and as a result a net self-pinching (magnetic) force is produced. The self-pinching effect is of particular practical importance, and is used in various ion driver designs in order to control the transverse beam envelope. In the present work we demonstrate that this radial self-focusing force can be significantly enhanced if a weak (B {approx} 100 G) solenoidal magnetic field is applied inside the neutralized drift section, thus allowing for substantially improved transport. It is shown that in contrast to magnetic self-pinching, the enhanced collective self-focusing has a radial electric field component and occurs as a result of the overcompensation of the beam charge by plasma electrons, whereas the beam current becomes well-neutralized. As the beam leaves the neutralizing drift section, additional transverse focusing can be applied. For instance, in the neutralized drift compression experiments (NDCX) a strong (several Tesla) final focus solenoid is used for this purpose. In the present analysis we propose that the tight final focus in the NDCX experiments may possibly be achieved by using a much weaker (few hundred Gauss) magnetic lens, provided the ion beam carries an equal amount of co-moving neutralizing electrons from the preceding drift section into the lens. In this case the enhanced focusing is provided by the collective electron dynamics strongly affected by a weak applied magnetic field.

  9. Enhanced collective focusing of intense neutralized ion beam pulses in the presence of weak solenoidal magnetic fields

    DOE PAGESBeta

    Dorf, Mikhail A.; Davidson, Ronald C.; Kaganovich, Igor D.; Startsev, Edward A.

    2012-05-31

    In this study, the design of ion drivers for warm dense matter and high energy density physics applications and heavy ion fusion involves transverse focusing and longitudinal compression of intense ion beams to a small spot size on the target. To facilitate the process, the compression occurs in a long drift section filled with a dense background plasma, which neutralizes the intense beam self-fields. Typically, the ion bunch charge is better neutralized than its current, and as a result a net self-pinching (magnetic) force is produced. The self-pinching effect is of particular practical importance, and is used in various ionmore » driver designs in order to control the transverse beam envelope. In the present work we demonstrate that this radial self-focusing force can be significantly enhanced if a weak (B~100 G) solenoidal magnetic field is applied inside the neutralized drift section, thus allowing for substantially improved transport. It is shown that in contrast to magnetic self-pinching, the enhanced collective self-focusing has a radial electric field component and occurs as a result of the overcompensation of the beam charge by plasmaelectrons, whereas the beam current becomes well-neutralized. As the beam leaves the neutralizing drift section, additional transverse focusing can be applied. For instance, in the neutralized drift compression experiments (NDCX) a strong (several Tesla) final focus solenoid is used for this purpose. In the present analysis we propose that the tight final focus in the NDCX experiments may possibly be achieved by using a much weaker (few hundred Gauss) magnetic lens, provided the ion beam carries an equal amount of co-moving neutralizing electrons from the preceding drift section into the lens. In this case the enhanced focusing is provided by the collective electrondynamics strongly affected by a weak applied magnetic field.« less

  10. Solenoid Magnet System for the Fermilab Mu2e Experiment

    SciTech Connect

    Lamm, M. J.; Andreev, N.; Ambrosio, G.; Brandt, J.; Coleman, R.; Evbota, D.; Kashikhin, V. V.; Lopes, M.; Miller, J.; Nicol, T.; Ostojic, R.; Page, T.; Peterson, T.; Popp, J.; Pronskikh, V.; Tang, Z.; Tartaglia, M.; Wake, M.; Wands, R.; Yamada, R.

    2011-12-14

    The Fermilab Mu2e experiment seeks to measure the rare process of direct muon to electron conversion in the field of a nucleus. Key to the design of the experiment is a system of three superconducting solenoids; a muon production solenoid (PS) which is a 1.8 m aperture axially graded solenoid with a peak field of 5 T used to focus secondary pions and muons from a production target located in the solenoid aperture; an 'S shaped' transport solenoid (TS) which selects and transports the subsequent muons towards a stopping target; a detector solenoid (DS) which is an axially graded solenoid at the upstream end to focus transported muons to a stopping target, and a spectrometer solenoid at the downstream end to accurately measure the momentum of the outgoing conversion elections. The magnetic field requirements, the significant magnetic coupling between the solenoids, the curved muon transport geometry and the large beam induced energy deposition into the superconducting coils pose significant challenges to the magnetic, mechanical, and thermal design of this system. In this paper a conceptual design for the magnetic system which meets the Mu2e experiment requirements is presented.

  11. Magnetic design constraints of helical solenoids

    SciTech Connect

    Lopes, M. L.; Krave, S. T.; Tompkins, J. C.; Yonehara, K.; Flanagan, G.; Kahn, S. A.; Melconian, K.

    2015-01-30

    Helical solenoids have been proposed as an option for a Helical Cooling Channel for muons in a proposed Muon Collider. Helical solenoids can provide the required three main field components: solenoidal, helical dipole, and a helical gradient. In general terms, the last two are a function of many geometric parameters: coil aperture, coil radial and longitudinal dimensions, helix period and orbit radius. In this paper, we present design studies of a Helical Solenoid, addressing the geometric tunability limits and auxiliary correction system.

  12. Solenoid Magnet System for the Fermilab Mu2e Experiment

    DOE PAGESBeta

    Lamm, M. J.; Andreev, N.; Ambrosio, G.; Brandt, J.; Coleman, R.; Evbota, D.; Kashikhin, V. V.; Lopes, M.; Miller, J.; Nicol, T.; et al

    2011-12-14

    The Fermilab Mu2e experiment seeks to measure the rare process of direct muon to electron conversion in the field of a nucleus. Key to the design of the experiment is a system of three superconducting solenoids; a muon production solenoid (PS) which is a 1.8 m aperture axially graded solenoid with a peak field of 5 T used to focus secondary pions and muons from a production target located in the solenoid aperture; an 'S shaped' transport solenoid (TS) which selects and transports the subsequent muons towards a stopping target; a detector solenoid (DS) which is an axially graded solenoidmore » at the upstream end to focus transported muons to a stopping target, and a spectrometer solenoid at the downstream end to accurately measure the momentum of the outgoing conversion elections. The magnetic field requirements, the significant magnetic coupling between the solenoids, the curved muon transport geometry and the large beam induced energy deposition into the superconducting coils pose significant challenges to the magnetic, mechanical, and thermal design of this system. In this paper a conceptual design for the magnetic system which meets the Mu2e experiment requirements is presented.« less

  13. Modified Solenoid Coil That Efficiently Produces High Amplitude AC Magnetic Fields With Enhanced Uniformity for Biomedical Applications

    PubMed Central

    Bordelon, David E.; Goldstein, Robert C.; Nemkov, Valentin S.; Kumar, Ananda; Jackowski, John K.; DeWeese, Theodore L.; Ivkov, Robert

    2014-01-01

    In this paper, we describe a modified solenoid coil that efficiently generates high amplitude alternating magnetic fields (AMF) having field uniformity (≤10%) within a 125-cm3 volume of interest. Two-dimensional finite element analysis (2D-FEA) was used to design a coil generating a targeted peak AMF amplitude along the coil axis of ~100 kA/m (peak-to-peak) at a frequency of 150 kHz while maintaining field uniformity to >90% of peak for a specified volume. This field uniformity was realized by forming the turns from cylindrical sections of copper plate and by adding flux concentrating rings to both ends of the coil. Following construction, the field profile along the axes of the coil was measured. An axial peak field value of 95.8 ± 0.4 kA/m was measured with 650 V applied to the coil and was consistent with the calculated results. The region of axial field uniformity, defined as the distance over which field ≥90% of peak, was also consistent with the simulated results. We describe the utility of such a device for calorimetric measurement of nanoparticle heating for cancer therapy and for magnetic fluid hyperthermia in small animal models of human cancer. PMID:25392562

  14. Electron motion in solenoidal magnetic fields using a first order symplectic integration algorithm

    SciTech Connect

    Fraser, J.S.

    1984-05-07

    The use of nonsymplectic procedures in particle tracing codes for relativistic electrons leads to errors that can be reduced only at the expense of using very small integration steps. More accurate results are obtained with symplectic transformations for position and momentum. A first-order symplectic integration procedure requires an iterative calculation of the new position coordinates using the old momenta, but the process usually converges in three or four steps. A first-order symplectic algorithm has been coded for cylindrical as well as Cartesian coordinates using the relativistic equations of motion with Hamiltonian variables. The procedure is applied to the steering of a beam of 80-keV electrons by a weak transverse magnetic field superposed on a strong magnetic field in the axial direction. The steering motion is shown to be parallel to the transverse field rather than perpendicular as would be the case without the strong axial field.

  15. Controlling Charge and Current Neutralization of an Ion Beam Pulse in a Background Plasma by Application of a Small Solenoidal Magnetic Field

    SciTech Connect

    Kaganovich, I. D.; Startsev, E. A.; Sefkow, A. B.; Davidson, R. C.

    2007-08-01

    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 analytical 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 analytical studies show that the solenoidal magnetic field starts to influence the self-electric and self-magnetic fields when ωce ≥ ωpeβb, where ωce = eΒ/mec is the electron gyrofrequency, ωpe is the electron plasma frequency, and βb = Vb/c is the ion beam velocity relative to the speed of light. This condition typically holds for relatively small magnetic fields (about 100G). Analytical formulas are derived for the effective radial force acting on the beam ions, which can be used to minimize beam pinching. The results of analytical theory have been verified by comparison with the simulation results obtained from two particle-in-cell codes, which show good agreement.

  16. Analysis of off-axis solenoid fields using the magnetic scalar potential: An application to a Zeeman-slower for cold atoms

    NASA Astrophysics Data System (ADS)

    Muniz, Sérgio R.; Bagnato, Vanderlei S.; Bhattacharya, M.

    2015-06-01

    In a region free of currents, magnetostatics can be described by the Laplace equation of a scalar magnetic potential, and one can apply the same methods commonly used in electrostatics. Here, we show how to calculate the general vector field inside a real (finite) solenoid, using only the magnitude of the field along the symmetry axis. Our method does not require integration or knowledge of the current distribution and is presented through practical examples, including a nonuniform finite solenoid used to produce cold atomic beams via laser cooling. These examples allow educators to discuss the nontrivial calculation of fields off-axis using concepts familiar to most students, while offering the opportunity to introduce themes of current modern research.

  17. Design and characterization of permanent magnetic solenoids for REGAE

    NASA Astrophysics Data System (ADS)

    Hachmann, M.; Flöttmann, K.; Gehrke, T.; Mayet, F.

    2016-09-01

    REGAE is a small electron linear accelerator at DESY. In order to focus short and low charged electron bunches down to a few μm permanent magnetic solenoids were designed, assembled and field measurements were done. Due to a shortage of space close to the operation area an in-vacuum solution has been chosen. Furthermore a two-ring design made of wedges has been preferred in terms of beam dynamic issues. To keep the field quality of a piecewise built magnet still high a sorting algorithm for the wedge arrangement including a simple magnetic field model has been developed and used for the construction of the magnets. The magnetic field of these solenoids has been measured with high precision and compared to simulations.

  18. Study of high field superconducting solenoids for muon beam cooling

    SciTech Connect

    Kashikhin, V.V.; Barzi, E.; Kashikhin, V.S.; Lamm, Michael J.; Sadovskiy, Y.; Zlobin, Alexander V; /Fermilab

    2007-08-01

    The final beam cooling stages of a possible Muon Collider may require DC solenoid magnets with magnetic fields of 40-50 T in an aperture of 40-50 mm. In this paper we study possible solutions towards creating DC fields of that order using available superconductors. Several magnetic and mechanical designs, optimized for the maximum performance are presented and compared in terms of cost and size.

  19. Whistler Wave Excitation and Effects of Self-Focusing on Ion Beam Propagation through a Background Plasma along a Solenoidal Magnetic Field

    SciTech Connect

    Mikhail, Dorf A.; Kaganovich, Igor D.; Startsev, Edward A.; Davidson, Ronald C.

    2010-02-02

    This paper extends studies of ion beam transport through a background plasma along a solenoidal magnetic field [I. Kaganovich et al., Phys. Plasmas 15, 103108 (2008)] to the important regime of moderate magnetic field strength satisfying ωce > 2βbωpe . Here, ωce and ω pe are the electron cyclotron frequency and electron plasma frequency, respectively, and βb = vb/ c is the directed ion beam velocity normalized to the speed of light. The electromagnetic field perturbations excited by the ion beam pulse in this regime are calculated analytically, and verified by comparison with the numerical simulations. The degrees of beam charge neutralization and current neutralization are estimated, and the transverse component of the Lorentz force associated with the excited electromagnetic field is calculated. It is found that the plasma response to the ion beam pulse is significantly different depending on whether the value of the solenoidal magnetic field is below or above the threshold value specified by ω cr ce = 2βbωpe, and corresponding to the resonant excitation of large-amplitude whistler waves. The use of intense whistler wave excitations for diagnostic purposes is also discussed.

  20. Experimental results of a single emittance compensation solenoidal magnet

    SciTech Connect

    Palmer, D.T.; Miller, R.H.; Wang, X.J.; Ben-Zvi, I.; Skaritka, J.

    1997-07-01

    A new iron dominated single emittance compensation solenoidal magnet was designed to be integrated with the BNL/SLAC/UCLA 1.6 cell S-Band Photocathode rf Gun. This emittance compensated photoinjector is now in operation at the Brookhaven Accelerator Test Facility. It has produced a 0.329 {+-} 0.012 pC, {tau}{sub 95%} = 10.9 psec electron bunches with a normalized rms transverse emittance of {epsilon}{sub n,rms} = 1.17 {+-} 0.16 {pi} mm mrad. POISSON field maps were used with PARMELA to optimize the emittance compensation solenoidal magnet design. Magnetic field measurements show that at the cathode plane B{sub z} {le} 10 G for a peak magnetic field of B{sub z,max} = 3 kG. Which is in agreement with POISSON simulation. A single emittance compensation solenoidal magnet will produces an initial angular momentum of the electron bunch that manifests itself in a initial magnetic emittance term that cannot be eliminated. This magnetic emittance {epsilon}{sub n,rms}{sup mag} scales as 0.010 {pi} mm mrad/G as the cathode, which is in agreement with PARMELA simulations. Experimental beam dynamics results are presented that shows relative angular rotation and spot size as a function of cathode magnetic field. These results are compared to theory.

  1. Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method

    SciTech Connect

    Arbelaez, D.; Madur, A.; Lipton, T.M.; Waldron, W.L.; Kwan, J.W.

    2011-04-01

    A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 {micro}m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.

  2. Laser ion source with solenoid field

    SciTech Connect

    Kanesue, Takeshi Okamura, Masahiro; Fuwa, Yasuhiro; Kondo, Kotaro

    2014-11-10

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 10{sup 11}, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

  3. Laser ion source with solenoid field

    SciTech Connect

    Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; Okamura, Masahiro

    2014-11-12

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. In this study, the laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 1011, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

  4. Laser ion source with solenoid field

    DOE PAGESBeta

    Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; Okamura, Masahiro

    2014-11-12

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. In this study, the laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 1011, whichmore » was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.« less

  5. Laser ion source with solenoid field

    NASA Astrophysics Data System (ADS)

    Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; Okamura, Masahiro

    2014-11-01

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 1011, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

  6. The Mechanical Design Optimization of a High Field HTS Solenoid

    SciTech Connect

    Lalitha, SL; Gupta, RC

    2015-06-01

    This paper describes the conceptual design optimization of a large aperture, high field (24 T at 4 K) solenoid for a 1.7 MJ superconducting magnetic energy storage device. The magnet is designed to be built entirely of second generation (2G) high temperature superconductor tape with excellent electrical and mechanical properties at the cryogenic temperatures. The critical parameters that govern the magnet performance are examined in detail through a multiphysics approach using ANSYS software. The analysis results formed the basis for the performance specification as well as the construction of the magnet.

  7. Alternative Methods for Field Corrections in Helical Solenoids

    SciTech Connect

    Lopes, M. L.; Krave, S. T.; Tompkins, J. C.; Yonehara, K.; Flanagan, G.; Kahn, S. A.; Melconian, K.

    2015-05-01

    Helical cooling channels have been proposed for highly efficient 6D muon cooling. Helical solenoids produce solenoidal, helical dipole, and helical gradient field components. Previous studies explored the geometric tunability limits on these main field components. In this paper we present two alternative correction schemes, tilting the solenoids and the addition of helical lines, to reduce the required strength of the anti-solenoid and add an additional tuning knob.

  8. Field measurements in the Fermilab electron cooling solenoid prototype

    SciTech Connect

    A. C. Crawford et al.

    2003-10-02

    To increase the Tevatron luminosity, Fermilab is developing a high-energy electron cooling system [1] to cool 8.9-GeV/c antiprotons in the Recycler ring. The schematic layout of the Recycler Electron Cooling (REC) system is shown in Figure 1. Cooling of antiprotons requires a round electron beam with a small angular spread propagating through a cooling section with a kinetic energy of 4.3 MeV. To confine the electron beam tightly and to keep its transverse angles below 10{sup -4} rad, the cooling section will be immersed into a solenoidal field of 50-150G. As part of the R&D effort, a cooling section prototype consisting of 9 modules (90% of the total length of a future section) was assembled and measured. This paper describes the technique of measuring and adjusting the magnetic field quality in the cooling section and presents preliminary results of solenoid prototype field measurements. The design of the cooling section solenoid is discussed in Chapter 2. Chapter 3 describes details of a dedicated measurement system, capable of measuring small transverse field components, while the system's measurement errors are analyzed in Chapter 4. Chapter 5 contains measured field distributions of individual elements of the cooling section as well as an evaluation of the magnetic shielding efficiency. An algorithm of field adjustments for providing lowest possible electron trajectory perturbations is proposed in Chapter 6; also, this chapter shows the results of our first attempts of implementing the algorithm.

  9. Collective Focusing of a Plasma-Neutralized Intense Ion Beam Propagating Along a Weak Solenoidal Magnetic Field

    NASA Astrophysics Data System (ADS)

    Dorf, Mikhail A.; Kaganovich, Igor D.; Startsev, Edward A.; Davidson, Ronald C.

    2009-11-01

    Two schemes are considered for focusing intense ion beams utilizing the collective dynamics of plasma electrons. In the first approach, an ion beam propagates through a neutralizing background plasma along a uniform magnetic field. In the second approach, an ion beam passes through a finite size plasma, extracts neutralizing electrons from the plasma, and then enters a magnetic lens. In the both cases, a strong radial electric field is produced due to the collective electron dynamics. This self-electric field provides the enhanced transverse focusing of the ion beam. Detailed analytical and advanced numerical studies using particle-in-cell simulations are performed for both approaches. The radial focusing force acting on beam ions is calculated for an arbitrary ratio between the electron cyclotron and plasma frequencies. Collective focusing effects are shown to be important for the design of heavy ion drivers for high energy density and warm dense matter physics applications.

  10. Studies on the Magnetic Center of the Mu2e Solenoid System

    SciTech Connect

    Lopes, M. L.; Ambrosio, G.; Buehler, M.; Coleman, R.; Evbota, D.; Khalatian, V.; Lamm, M.; Miller, J.; Moretti, G.; Page, T.; Tartaglia, M.

    2014-01-01

    The definition of the magnetic center in the Mu2e solenoid system is not trivial given the S-shaped nature of the transport solenoid. Moreover, due to the fringe field of the larger bore adjacent magnets-production solenoid and the detector solenoid-the magnetic center does not coincide with the geometric center of the system. The reference magnetic center can be obtained by tracking a low-momentum charged particle through the whole system. This paper will discuss this method and will evaluate the deviations from the nominal magnetic center given the tolerances in the manufacturing and the alignment of the coils. Methods for the correction of the magnetic center will also be presented.

  11. Solenoidal Fields for Ion Beam Transport and Focusing

    SciTech Connect

    Lee, Edward P.; Leitner, Matthaeus

    2007-11-01

    In this report we calculate time-independent fields of solenoidal magnets that are suitable for ion beam transport and focusing. There are many excellent Electricity and Magnetism textbooks that present the formalism for magnetic field calculations and apply it to simple geometries [1-1], but they do not include enough relevant detail to be used for designing a charged particle transport system. This requires accurate estimates of fringe field aberrations, misaligned and tilted fields, peak fields in wire coils and iron, external fields, and more. Specialized books on magnet design, technology, and numerical computations [1-2] provide such information, and some of that is presented here. The AIP Conference Proceedings of the US Particle Accelerator Schools [1-3] contain extensive discussions of design and technology of magnets for ion beams - except for solenoids. This lack may be due to the fact that solenoids have been used primarily to transport and focus particles of relatively low momenta, e.g. electrons of less than 50 MeV and protons or H- of less than 1.0 MeV, although this situation may be changing with the commercial availability of superconducting solenoids with up to 20T bore field [1-4]. Internal reports from federal laboratories and industry treat solenoid design in detail for specific applications. The present report is intended to be a resource for the design of ion beam drivers for Inertial Fusion Energy [1-5] and Warm Dense Matter experiments [1-6], although it should also be useful for a broader range of applications. The field produced by specified currents and material magnetization can always be evaluated by solving Maxwell's equations numerically, but it is also desirable to have reasonably accurate, simple formulas for conceptual system design and fast-running beam dynamics codes, as well as for general understanding. Most of this report is devoted to such formulas, but an introduction to the Tosca{copyright} code [1-7] and some numerical

  12. Residual magnetism holds solenoid armature in desired position

    NASA Technical Reports Server (NTRS)

    Crawford, R. P.

    1967-01-01

    Holding solenoid uses residual magnetism to hold its armature in a desired position after excitation current is removed from the coil. Although no electrical power or mechanical devices are used, the solenoid has a low tolerance to armature displacement from the equilibrium position.

  13. Study of HTS Insert Coils for High Field Solenoids

    SciTech Connect

    Lombardo, Vito; /Fermilab

    2009-09-01

    Fermilab is currently working on the development of high field magnet systems for ionization cooling of muon beams. The use of high temperature superconducting materials (HTS) is being considered for these solenoids using Helium refrigeration. Several studies have been performed on insert coils made of BSCCO-2223 tapes and second generation (2G) YBCO coated conductors, which are tested at various temperatures and at external fields of up to 14 T. Critical current (I{sub c}) measurements of YBCO short samples are presented as a function of bending stress, magnetic field and field orientation with respect to the sample surface. An analytical fit of critical current data as a function of field and field orientation is also presented. Results from several single-layer and double-layer pancake coils are also discussed.

  14. Optimum dimensions of power solenoids for magnetic suspension

    NASA Technical Reports Server (NTRS)

    Kaznacheyev, B. A.

    1985-01-01

    Design optimization of power solenoids for controllable and stabilizable magnetic suspensions with force compensation in a wind tunnel is shown. It is assumed that the model of a levitating body is a sphere of ferromagnetic material with constant magnetic permeability. This sphere, with a radius much smaller than its distance from the solenoid above, is to be maintained in position on the solenoid axis by balance of the vertical electromagnetic force and the force of gravitation. The necessary vertical (axial) force generated by the solenoid is expressed as a function of relevant system dimensions, solenoid design parameters, and physical properties of the body. Three families of curves are obtained which depict the solenoid power for a given force as a function of the solenoid length with either outside radius or inside radius as a variable parameter and as a function of the outside radius with inside radius as a variable parameter. The curves indicate the optimum solenoid length and outside radius, for minimum power, corresponding to a given outside radius and inside radius, respectively.

  15. Electromotive force and current in a superconducting solenoid with limited length induced by a bar magnet and a monopole

    NASA Astrophysics Data System (ADS)

    Ma, Lianxi

    The magnetic flux ΦB, electromotive force, EMF, and current Iin, induced by a moving magnetic bar and an imaginary magnetic monopole in a superconducting solenoid of multiple turns and length L, are numerically calculated. The magnetic field of the bar magnet is approximated with the magnetic field along z axis of a solenoid with length l and radius a and current I, while the magnetic field of the monopole is supposed to be inversely proportional to r2. Calculations show that, for a bar magnet, ΦB and Iin essentially saturate when the bar moves inside superconducting solenoid, so EMF is zero while Iin is constant. EMF is only induced when the bar enters and exits the solenoid and Iin is zero after the bar leaves the solenoid. For a magnetic monopole, ΦB is discontinuous (from positive maximum to negative maximum) when the it moves through each turn of the superconducting solenoid, but EMF caused by dΦB /dt is continuous while the EMF induced by the a moving monopole is a delta function (moving monopole produces a ring-shaped E field). The total EMFTot in solenoid is the superposition of EMF of each turn of coil and the plateau appears. The current Iin continues to grow while the monopole leaves the solenoid. Thanks to Dr. Liancun Zheng and Mr. Lin Liu for verifying my calculation.

  16. Confinement of laser plasma by solenoidal field for laser ion source

    SciTech Connect

    Okamura, M.; Kanesue,T.; Kondo, K.; Dabrowski, R.

    2010-05-23

    A laser ion source can provide high current, highly charged ions with a simple structure. However, it was not easy to control the ion pulse width. To provide a longer ion beam pulse, the plasma drift length, which is the distance between laser target and extraction point, has to be extended and as a result the plasma is diluted severely. Previously, we applied a solenoid field to prevent reduction of ion density at the extraction point. Although a current enhancement by a solenoid field was observed, plasma behavior after a solenoid magnet was unclear because plasma behavior can be different from usual ion beam dynamics. We measured a transverse ion distribution along the beam axis to understand plasma motion in the presence of a solenoid field.

  17. CALCULATIONS FOR A MERCURY JET TARGET IN A SOLENOID MAGNET CAPTURE SYSTEM.

    SciTech Connect

    GALLARDO, J.; KAHN, S.; PALMER, R.B.; THIEBERGER, P.; WEGGEL, R.J.; MCDONALD, K.

    2001-06-18

    A mercury jet is being considered as the production target for a muon storage ring facility to produce an intense neutrino beam. A 20 T solenoid magnet that captures pions for muon production surrounds the mercury target. As the liquid metal jet enters or exits the field eddy currents are induced. We calculate the effects that a liquid metal jet experiences in entering and exiting the magnetic field for the magnetic configuration considered in the Neutrino Factory Feasibility Study II.

  18. RF and Magnetic Measurements on the SPARC Photoinjector and Solenoid at UCLA

    SciTech Connect

    Rosenzweig, J.B.; Cook, A.M.; Dunning, M.P.; Frigola, P.; Travish, G.; Sanelli, C.; Tazzioli, F.; Palmer, D.T.; /SLAC

    2006-01-30

    The rf photocathode gun and the solenoid for the SPARC project at INFN-LNF (Frascati) have been fabricated and undergone initial testing at UCLA. The advanced aspects of the design of these devices are detailed. Final diagnosis of the tuning of the RF gun performance, including operating mode frequency and field balance, is described. The emittance compensating solenoid magnet, which is designed to be tuned in longitudinal position by differential excitation of the coils, has been measured using Hall probe scans for field profiling, and pulsed wire methods to determine the field center. Comparisons between measurements and the predictions of design codes are made.

  19. Analysis of eddy current distributions in the CMS magnet yoke during the solenoid discharge

    SciTech Connect

    Klyukhin, V.I.; Campi, D.; Cure, B.; Gaddi, A.; Gerwig, H.; Grillet, J.P.; Herve, A.; Loveless, R.; Smith, R.P.; /Fermilab

    2005-01-01

    Flux loops have been installed on selected segments of the magnetic flux return yoke of the 4 T superconducting coil of the Compact Muon Solenoid (CMS) detector under construction at CERN. Voltages induced in the loops during discharge of the solenoid will be sampled on-line during the entire discharge and integrated off-line to provide a measurement of the initial magnetic flux density in steel at the maximum field to an accuracy of a few percent. Although the discharge of the solenoid is rather slow (190 s time constant), the influence of eddy currents induced in the yoke elements should be estimated. The calculation of eddy currents is performed with Vector Fields program ELEKTRA. The results of calculations are reported.

  20. High Magnetic field generation for laser-plasma experiments

    SciTech Connect

    Pollock, B B; Froula, D H; Davis, P F; Ross, J S; Fulkerson, S; Bower, J; Satariano, J; Price, D; Glenzer, S H

    2006-05-01

    An electromagnetic solenoid was developed to study the effect of magnetic fields on electron thermal transport in laser plasmas. The solenoid, which is driven by a pulsed power system suppling 30 kJ, achieves magnetic fields of 13 T. The field strength was measured on the solenoid axis with a magnetic probe and optical Zeeman splitting. The measurements agree well with analytical estimates. A method for optimizing the solenoid design to achieve magnetic fields exceeding 20 T is presented.

  1. Magnetic and Cryogenic Design of the MICE Coupling Solenoid Magnet System

    SciTech Connect

    Wang, Li; Xu, FengYu; Wu, Hong; Liu, XiaoKum; Li, LanKai; Guo, XingLong; Chen, AnBin; Green, Michael A; Li, D.R.; Virostek, Steve; Pan, H.

    2008-08-02

    The Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling in a short section of a realistic cooling channel using a muon beam at Rutherford Appleton Laboratory in the UK. The coupling magnet is a superconducting solenoid mounted around four 201MHz RF cavities, which produces magnetic field up to 2.6 T on the magnet centerline to keep muons within the iris of RF cavities windows. The coupling coil with inner radius of 750mm, length of 285mm and thickness of 102.5mm will be cooled by a pair of 1.5 W at 4.2 K small coolers. This paper will introduce the updated engineering design of the coupling magnet made by ICST in China. The detailed analyses on magnetic fields, stresses induced during the processes of winding, cool down and charging, and cold mass support assembly are presented as well.

  2. Effect of superconducting solenoid model cores on spanwise iron magnet roll control

    NASA Technical Reports Server (NTRS)

    Britcher, C. P.

    1985-01-01

    Compared with conventional ferromagnetic fuselage cores, superconducting solenoid cores appear to offer significant reductions in the projected cost of a large wind tunnel magnetic suspension and balance system. The provision of sufficient magnetic roll torque capability has been a long-standing problem with all magnetic suspension and balance systems; and the spanwise iron magnet scheme appears to be the most powerful system available. This scheme utilizes iron cores which are installed in the wings of the model. It was anticipated that the magnetization of these cores, and hence the roll torque generated, would be affected by the powerful external magnetic field of the superconducting solenoid. A preliminary study has been made of the effect of the superconducting solenoid fuselage model core concept on the spanwise iron magnet roll torque generation schemes. Computed data for one representative configuration indicate that reductions in available roll torque occur over a range of applied magnetic field levels. These results indicate that a 30-percent increase in roll electromagnet capacity over that previously determined will be required for a representative 8-foot wind tunnel magnetic suspension and balance system design.

  3. Scattering detection of a solenoidal Poynting vector field.

    PubMed

    Fardad, Shima; Salandrino, Alessandro; Samadi, Akbar; Heinrich, Matthias; Chen, Zhigang; Christodoulides, Demetrios N

    2016-08-01

    The Poynting vector S plays a central role in electrodynamics as it is directly related to the power and the momentum carried by an electromagnetic wave. In the presence of multiple electromagnetic waves with different polarizations and propagation directions, the Poynting vector may exhibit solenoidal components which are not associated to any power flow. Here, we demonstrate theoretically and experimentally that the presence of such solenoidal components has physical consequences, and it is not a mere artifact of the gauge invariance of S. In particular, we identify a simple field configuration displaying solenoidal components of S and theoretically show that a judiciously designed scatterer can act as a "Poynting vector detector" which when immersed in such field distribution would experience a transverse optical force orthogonal to the incidence plane. We experimentally validate our theoretical predictions by observing a pronounced asymmetry in the scattering pattern of a spherical nanoparticle. PMID:27472632

  4. A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms.

    PubMed

    Huo, Ming-Xia; Nie, Wei; Hutchinson, David A W; Kwek, Leong Chuan

    2014-01-01

    Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a "hairline" solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions. PMID:25103877

  5. A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms

    NASA Astrophysics Data System (ADS)

    Huo, Ming-Xia; Nie, Wei; Hutchinson, David A. W.; Kwek, Leong Chuan

    2014-08-01

    Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a ``hairline'' solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions.

  6. A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms

    PubMed Central

    Huo, Ming-Xia; Nie, Wei; Hutchinson, David A. W.; Kwek, Leong Chuan

    2014-01-01

    Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a “hairline” solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions. PMID:25103877

  7. Progress on Design and Construction of a MuCool Coupling Solenoid Magnet

    SciTech Connect

    Wang, L.; Liu, Xiao Kun; Xu, FengYu; Li, S.; Pan, Heng; Wu, Hong; Guo, Xinglong; Zheng, ShiXian; Li, Derun; Virostek, Steve; Zisman, Mike; Green, M.A.

    2010-06-28

    The MuCool program undertaken by the US Neutrino Factory and Muon Collider Collaboration is to study the behavior of muon ionization cooling channel components. A single superconducting coupling solenoid magnet is necessary to pursue the research and development work on the performance of high gradient, large size RF cavities immersed in magnetic field, which is one of the main challenges in the practical realization of ionization cooling of muons. The MuCool coupling magnet is to be built using commercial copper based niobium titanium conductors and cooled by two cryo-coolers with each cooling capacity of 1.5 W at 4.2 K. The solenoid magnet will be powered by using a single 300A power supply through a single pair of binary leads that are designed to carry a maximum current of 210A. The magnet is to be passively protected by cold diodes and resistors across sections of the coil and by quench back from the 6061 Al mandrel in order to lower the quench voltage and the hot spot temperature. The magnet is currently under construction. This paper presents the updated design and fabrication progress on the MuCool coupling magnet.

  8. Measured Effects of a Longitudinal Solenoidal Field on an Iron Quadrupole

    NASA Astrophysics Data System (ADS)

    Ecklund, S.; Seeman, J. T.; Wolf, Z.

    1997-05-01

    We have measured the effects of a longitudinal solenoidal field on the field harmonics of an iron dominated quadrupole. These measurements are useful when designing a colliding beam interaction region where the first quadrupole is very near the solenoidal field of the physics detector. The effects of mirror plates, quadrupole excition, skew quadrupole windings, dipole windings, and solenoidal fields that enter at an angle have been measured. Conclusions and interpretations are given.

  9. A unique 30 Tesla single-solenoid pulsed magnet instrument for x-ray studies

    NASA Astrophysics Data System (ADS)

    Islam, Zahirul; Capatina, Dana; Ruff, Jacob; Das, Ritesh; Nojiri, Hiroyuki; Narumi, Yasuo

    2011-03-01

    We present a dual-cryostat pulsed-magnet instrument at the Advanced Photon Source (APS) with unique capabilities. The dual-cryostat independently cools the solenoid (Tohoku design) using liquid nitrogen and the sample using a closed-cycle refrigerator, respectively. Liquid nitrogen (LN) cooling allows a repetition rate of seven minutes for peak fields of 30 Tesla. The system is unique in that the LN cryostat incorporates a double-funnel vacuum tube passing through the solenoid's bore preserving the entire angular range allowed by the magnet. This scheme is advantageous in that it allows the applied magnetic field to be parallel to the scattering plane complementing typical split-pair magnets with fields normal to the scattering plane. Performance of the coils along with preliminary x-ray diffraction and spectroscopic studies will be presented. Use of the APS is supported by the U. S. DOE, Office of Science, under Contract No. DE-AC02-06CH11357. The work was supported in part by ICC-IMR, Tohoku University.

  10. Design, Fabrication, and Test of a Superconducting Dipole Magnet Based on Tilted Solenoids

    SciTech Connect

    Caspi, S.; Dietderich, D. R.; Ferracin, P.; Finney, N. R.; Fuery, M. J.; Gourlay, S. A.; Hafalia, A. R.

    2007-06-01

    It can be shown that, by superposing two solenoid-like thin windings that are oppositely skewed (tilted) with respect to the bore axis, the combined current density on the surface is 'cos-theta' like and the resulting magnetic field in the bore is a pure dipole. As a proof of principle, such a magnet was designed, built and tested as part of a summer undergraduate intern project. The measured field in the 25mm bore, 4 single strand layers using NbTi superconductor, exceeded 1 T. The simplicity of this high field quality design, void of typical wedges end-spacers and coil assembly, is especially suitable for insert-coils using High Temperature Superconducting wire as well as for low cost superconducting accelerator magnets for High Energy Physics. Details of the design, construction and test are reported.

  11. LCLS Gun Solenoid Design Considerations

    SciTech Connect

    Schmerge, John

    2010-12-10

    The LCLS photocathode rf gun requires a solenoid immediately downstream for proper emittance compensation. Such a gun and solenoid have been operational at the SSRL Gun Test Facility (GTF) for over eight years. Based on magnetic measurements and operational experience with the GTF gun solenoid multiple modifications are suggested for the LCLS gun solenoid. The modifications include adding dipole and quadrupole correctors inside the solenoid, increasing the bore to accommodate the correctors, decreasing the mirror plate thickness to allow the solenoid to move closer to the cathode, cutouts in the mirror plate to allow greater optical clearance with grazing incidence cathode illumination, utilizing pancake coil mirror images to compensate the first and second integrals of the transverse fields and incorporating a bipolar power supply to allow for proper magnet standardization and quick polarity changes. This paper describes all these modifications plus the magnetic measurements and operational experience leading to the suggested modifications.

  12. Design features of the solenoid magnets for the central cell of the MFTF-B

    SciTech Connect

    Wohlwend, J.W.; Tatro, R.E.; Ring, D.S.

    1981-10-23

    The 14 superconducting solenoid magnets which form the central cell of the MFTF-B are being designed and fabricated by General Dynamics for the Lawrence Livermore National Laboratory. Each solenoid coil has a mean diameter of five meters and contains 600 turns of a proven conductor type. Structural loading resulting from credible fault events, cooldown and warmup requirements, and manufacturing processes consistent with other MFTF-B magnets have been considered in the selection of 304 LN as the structural material for the magnet. The solenoid magnets are connected by 24 intercoil beams and 20 solid struts which resist the longitudinal seismic and electromagnetic attractive forces and by 24 hanger/side supports which react magnet dead weight and seismic loads. A modular arrangement of two solenoid coils within a vacuum vessel segment allow for sequential checkout and installation.

  13. An Implantable RF Solenoid for Magnetic Resonance Microscopy and Microspectroscopy

    PubMed Central

    Cohen, Mark S.; Clark, W. Gilbert; Chu, Allen C.; Nunnally, Ray L.; Smith, Jolinda; Mills, Dixie; Judy, Jack W.

    2014-01-01

    Miniature solenoids routinely enhance small volume nuclear magnetic resonance imaging and spectroscopy; however, no such techniques exist for patients. We present an implantable microcoil for diverse clinical applications, with a microliter coil volume. The design is loosely based on implantable depth electrodes, in which a flexible tube serves as the substrate, and a metal stylet is inserted into the tube during implantation. The goal is to provide enhanced signal-to-noise ratio (SNR) of structures that are not easily accessed by surface coils. The first-generation prototype was designed for implantation up to 2 cm, and provided initial proof-of-concept for microscopy. Subsequently, we optimized the design to minimize the influence of lead inductances, and to thereby double the length of the implantable depth (4 cm). The second-generation design represents an estimated SNR improvement of over 30% as compared to the original design when extended to 4 cm. Impedance measurements indicate that the device is stable for up to 24 h in body temperature saline. We evaluated the SNR and MR-related heating of the device at 3T. The implantable microcoil can differentiate fat and water peaks, and resolve submillimeter features. PMID:22156945

  14. Jefferson Lab CLAS12 Superconducting Solenoid magnet Requirements and Design Evolution

    SciTech Connect

    Rajput-Ghoshal, Renuka; Hogan, John P.; Fair, Ruben J.; Ghoshal, Probir K.; Luongo, Cesar; Elouadrhiri, Latifa

    2014-12-01

    As part of the Jefferson Lab 12GeV accelerator upgrade project, one of the experimental halls (Hall B) requires two superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of 5 coils. In this presentation the physics requirements for the 5 T solenoid magnet, design constraints, conductor decision, and cooling choice will be discussed. The various design iterations to meet the specification will also be discussed in this presentation.

  15. Solenoid Fringe Field Effects for the Neutrino Factory Linac - MAD-X Investigation

    SciTech Connect

    M. Aslaninejad,C. Bontoiu,J. Pasternak,J. Pozimski,Alex Bogacz

    2010-05-01

    International Design Study for the Neutrino Factory (IDS-NF) assumes the first stage of muon acceleration (up to 900 MeV) to be implemented with a solenoid based Linac. The Linac consists of three styles of cryo-modules, containing focusing solenoids and varying number of SRF cavities for acceleration. Fringe fields of the solenoids and the focusing effects in the SRF cavities have significant impact on the transverse beam dynamics. Using an analytical formula, the effects of fringe fields are studied in MAD-X. The resulting betatron functions are compared with the results of beam dynamics simulations using OptiM code.

  16. Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

    SciTech Connect

    Molvik, A.W.; Kireeff Covo, M.; Cohen, R.; Coleman, J.; Sharp, W.; Bieniosek, F.; Friedman, A.; Roy, P.K.; Seidl, P.; Lund, S.M.; Faltens, A.; Vay, J.L.; Prost, L.

    2007-06-04

    The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam.

  17. Electrons in a Positive-Ion Beam with Solenoid or Quadrupole Magnet Transport

    SciTech Connect

    Molvik, A W; Cohen, R H; Friedman, A; Covo, M K; Lund, S M; Sharp, W M; Seidl, P A; Bieniosek, F M; Coleman, J E; Faltens, A; Roy, P K; Vay, J L; Prost, L

    2007-06-01

    The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam.

  18. Performance measurements of a pilot superconducting solenoid model core for a wind tunnel magnetic suspension and balance system

    NASA Technical Reports Server (NTRS)

    Goodyer, M. J.; Britcher, C. P.

    1983-01-01

    The results of experimental demonstrations of a superconducting solenoid model core in the Southampton University Magnetic Suspension and Balance System are detailed. Technology and techniques relevant to large-scale wind tunnel MSBSs comprise the long term goals. The magnetic moment of solenoids, difficulties peculiar to superconducting solenoid cores, lift force and pitching moment, dynamic lift calibration, and helium boil-off measurements are discussed.

  19. Solenoid Compensation for the SuperB Interaction Region

    SciTech Connect

    Bertsche, Kirk; Sullivan, Michael K.; /SLAC

    2010-08-25

    We present an approach for compensating adverse effects of the detector solenoid in the SuperB Interaction Region (IR). We place compensating solenoids around the IR quadrupole magnets to reduce the magnetic fields nearly to zero. This allows more operational headroom for superconducting IR magnets and avoids saturation of ferric IR magnets. We place stronger compensating solenoids between IR magnets to reverse the magnetic field direction. This allows adjusting the total integrated solenoid field to zero, which eliminates coordinate plane rotation and reduces vertical beam displacements in the IR.

  20. Plasma confinement apparatus using solenoidal and mirror coils

    DOEpatents

    Fowler, T. Kenneth; Condit, William C.

    1979-01-01

    A plasma confinement apparatus, wherein multiple magnetic mirror cells are linked by magnetic field lines inside of a solenoid with the mirroring regions for adjacent magnetic mirror cells each formed by a separate mirror coil inside of the solenoid. The magnetic mirror cells may be field reversed.

  1. The IRAC Shutter Mechanism: Residual Magnetism and the Rotary Solenoid

    NASA Technical Reports Server (NTRS)

    Schwinger, Scott; Hakun, Claef; Brown, Gary; Blumenstock, Ken

    2002-01-01

    The Infrared Array Camera (IRAC) Shutter mechanism was originally presented in the paper, 'A Low Power Cryogenic Shutter Mechanism for Use on Infrared Imagers' at the 34th Aerospace Mechanisms Symposium, May 2000. At that time, the shutter was believed to be performing flawlessly and there was every indication it would continue to do so. In early spring of 2001, the calibration shutter, a rotary solenoid designed to be fail-safe open, remained in a closed state with no power to the electromagnetic coils. The ensuing investigation, subsequent testing, proposed remedy, and lessons learned are the focus of this paper.

  2. Design of High Field Solenoids made of High Temperature Superconductors

    SciTech Connect

    Bartalesi, Antonio; /Pisa U.

    2010-12-01

    This thesis starts from the analytical mechanical analysis of a superconducting solenoid, loaded by self generated Lorentz forces. Also, a finite element model is proposed and verified with the analytical results. To study the anisotropic behavior of a coil made by layers of superconductor and insulation, a finite element meso-mechanic model is proposed and designed. The resulting material properties are then used in the main solenoid analysis. In parallel, design work is performed as well: an existing Insert Test Facility (ITF) is adapted and structurally verified to support a coil made of YBa{sub 2}Cu{sub 3}O{sub 7}, a High Temperature Superconductor (HTS). Finally, a technological winding process was proposed and the required tooling is designed.

  3. Design and Construction of a Prototype Solenoid Coil for MICE Coupling Magnets

    SciTech Connect

    Wang, Li; Pan, Heng; Guo, XingLong; Xu, FengYu; Liu, XiaoKun; Wu, Hong; Zheng, ShiXian; Green, Michael A; Li, Derun; Virostek, Steve; Zisman, Michael

    2010-06-28

    A superconducting coupling solenoid mounted around four conventional RF cavities, which produces up to 2.6 T central magnetic field to keep the muons within the cavities, is to be used for the Muon Ionization Cooling Experiment (MICE). The coupling coil made from copper matrix NbTi conductors is the largest of three types of magnets in MICE both in terms of 1.5 m inner diameter and about 13MJ stored magnetic energy at full operation current of 210A. The stress induced inside the coil assembly during cool down and magnet charging is relatively high. In order to validate the design method and develop the coil winding technique with inside-wound SC splices required for the coupling coil, a prototype coil made from the same conductor and with the same diameter and thickness but only one-fourth long as the coupling coil was designed and fabricated by ICST. The prototype coil was designed to be charged to strain conditions that are equivalent or greater than would be encountered in the coupling coil. This paper presents detailed design of the prototype coil as well as developed coil winding skills. The analyses on stress in the coil assembly and quench process were carried out.

  4. Some options for the muon collider capture and decay solenoids

    NASA Astrophysics Data System (ADS)

    Green, Michael A.

    1996-05-01

    This report discusses some of the problems associated with using solenoid magnets to capture the secondary particles that are created when an intense beam of 8 to 10 GeV protons interacts with the target at the center of the capture region. Hybrid capture solenoids with inductions of 28 T and a 22 T are described. The first 14 to 15 T of the solenoid induction will be generated by a superconducting magnet. The remainder of the field will be generated by a Bitter type of water cooled solenoid. The capture solenoids include a transition section from the high field solenoid to a 7 T decay channel where pions and kaons that come off of the target decay into muons. A short 7 T solenoidal decay channel between the capture solenoid system and the phase rotation system is described. A concept for separation of negative and positive pions and kaons is briefly discussed.

  5. Magnetic Fields at the Center of Coils

    ERIC Educational Resources Information Center

    Binder, Philippe; Hui, Kaleonui; Goldman, Jesse

    2014-01-01

    In this note we synthesize and extend expressions for the magnetic field at the center of very short and very long current-carrying coils. Elementary physics textbooks present the following equation for the magnetic field inside a very long current-carrying coil (solenoid): B[subscript sol] = µ[subscript 0] (N/L) I, (1) where I is the current, N…

  6. Design and Construction of Test Coils for the MICE Coupling Solenoid Magnet

    SciTech Connect

    Wang, Li; Pan, Heng; Xu, F.Y.; Liu, XioaKun; Chen, AnBin; Li, LanKai; Gou, XingLong; Wu, Hong; Green, Michael; Li, Darun; Strauss, Bruce

    2008-08-08

    The superconducting coupling solenoid to be applied in the Muon Ionization Cooling Experiment (MICE) is made from copper matrix Nb-Ti conductors with inner radius of 750 mm, length of 285 mm and thickness of 102.5 mm at room temperature. The magnetic field up to 2.6 T at the magnet centerline is to keep the muons within the MICE RF cavities. Its self inductance is around 592 H and its magnet stored energy is about 13 MJ at a full current of 210 A for the worst operation case of the MICE channel. The stress induced inside the coil during cool down and charging is relatively high. Two test coils are to build and test in order to validate the design method and develop the fabrication technique required for the coupling coil winding, one is 350 mm inner diameter and full length same as the coupling coil, and the other is one-quarter length and 1.5 m diameter. The 1.5 m diameter coil will be charged to strain conditions that are greater than would be encountered in the coupling coil. This paper presents detailed design of the test coils as well as developed winding skills. The analyses on stress in coil assemblies, AC loss, and quench process are carried out.

  7. The Mechanical and Thermal Design for the MICE Focusing SolenoidMagnet System

    SciTech Connect

    Yang, S.Q.; Green, M.A.; Barr, G.; Bravar, U.; Cobb, J.; Lau, W.; Senanayake, R.S.; White, A.E.; Witte, H.

    2004-05-07

    The focusing solenoids for MICE surround energy absorbers that are used to reduce the transverse momentum of the muon beam that is being cooled within MICE. The focusing solenoids will have a warm-bore diameter of 470 mm. Within this bore is a flask of liquid hydrogen or a room temperature beryllium absorber. The focusing solenoid consists of two coils wound with a copper matrix Nb-Ti conductor originally designed for MRI magnets. The two coils have separate leads, so that they may be operated at the same polarity or at opposite polarity. The focusing magnet is designed so that it can be cooled with a pair of 1.5 W (at 4.2 K) coolers. The MICE cooling channel has three focusing magnets with their absorbers. The three focusing magnets will be hooked together in series for a circuit stored-energy of about 9.0 MJ. Quench protection for the focusing magnets is discussed. This report presents the mechanical and thermal design parameters for this magnet, including the results of finite element calculations of mechanical forces and heat flow in the magnet cold mass.

  8. EFFECT OF SOLENOID FIELD ERRORS ON ELECTRON BEAM TEMPERATURES IN THE RHIC ELECTRON COOLER.

    SciTech Connect

    MONTAG,C.KEWISCH,J.

    2003-05-12

    As part of a future upgrade to the Relativistic Heavy Ion Collider (RHIC), electron cooling is foreseen to decrease ion beam emittances. Within the electron cooling section, the ''hot'' ion beam is immersed in a ''cold'' electron beam. The cooling effect is further enhanced by a solenoid field in the cooling section, which forces the electrons to spiral around the field lines with a (Larmor) radius of 10 micrometers, reducing the effective transverse temperature by orders of magnitude. Studies of the effect of solenoid field errors on electron beam temperatures are reported.

  9. High-field superconducting nested coil magnet

    NASA Technical Reports Server (NTRS)

    Laverick, C.; Lobell, G. M.

    1970-01-01

    Superconducting magnet, employed in conjunction with five types of superconducting cables in a nested solenoid configuration, produces total, central magnetic field strengths approaching 70 kG. The multiple coils permit maximum information on cable characteristics to be gathered from one test.

  10. Commissioning and Testing the 1970's Era LASS Solenoid Magnet in JLab's Hall D

    SciTech Connect

    Ballard, Joshua T.; Biallas, George H.; Brown, G.; Butler, David E.; Carstens, Thomas J.; Chudakov, Eugene A.; Creel, Jonathan D.; Egiyan, Hovanes; Martin, F.; Qiang, Yi; Smith, Elton S.; Stevens, Mark A.; Spiegel, Scot L.; Whitlatch, Timothy E.; Wolin, Elliott J.; Ghoshal, Probir K.

    2015-06-01

    JLab refurbished and reconfigured the LASS1, 1.85m bore Solenoid and installed it as the principal analysis magnet for nuclear physics in the newly constructed, Hall D at Jefferson Lab. The magnet contains four superconducting coils within an iron yoke. The magnet was built in the early1970's at Stanford Linear Accelerator Center and used a second time at Los Alamos National Laboratory. The coils were extensively refurbished and individually tested by JLab. A new Cryogenic Distribution Box provides cryogens and their control valving, current distribution bus, and instrumentation pass-through. A repurposed CTI 2800 refrigerator system and new transfer line complete the system. We describe the re-configuration, the process and problems of re-commissioning the magnet and the results of testing the completed magnet.

  11. Stress Analysis of the D-Zero Solenoid Magnet Lifting Fixture PPD Fixture #102

    SciTech Connect

    Zaczek, M.; /Fermilab

    1997-12-12

    This engineering note presents stress analysis calculations for the below the hook lifting fixture which will be used to move the D-Zero solenoid magnet during installation work at the D-Zero Assembly building. Load bearing structural members are shown to have a minimum design factor of 3 based on yield strength as required by ASME B30.20. All bolts were analyzed and shown to be kept below allowable loads/stresses listed in the American Institute of Steel Construction (AISC) manual. The lifting fixture will be manufactured at Fermilab using some material scavenged from an existing lifting fixture that was shipped with the magnet from the magnet manufacturer, Toshiba Corporation. The fixture is designed with built in versatility so that the solenoid magnet can be maneuvered through the stages of preparation and installation into it's final mounted position. The structure has been analyzed for all phases of its use, although the analysis of the structure as a below the hook lifting device is the main purpose of this note.

  12. Tolerance Studies of the Mu2e Solenoid System

    SciTech Connect

    Lopes, M. L.; Ambrosio, G.; Buehler, M.; Coleman, R.; Evbota, D.; Feher, S.; Kashikhin, V. V.; Lamm, M.; Miller, J.; Moretti, G.; Ostojic, R.; Page, T.; Popp, J.; Tartaglia, M.

    2014-01-01

    The muon-to-electron conversion experiment at Fermilab is designed to explore charged lepton flavor violation. It is composed of three large superconducting solenoids, namely, the production solenoid, the transport solenoid, and the detector solenoid. Each subsystem has a set of field requirements. Tolerance sensitivity studies of the magnet system were performed with the objective of demonstrating that the present magnet design meets all the field requirements. Systematic and random errors were considered on the position and alignment of the coils. The study helps to identify the critical sources of errors and which are translated to coil manufacturing and mechanical support tolerances.

  13. The effects of realistic pancake solenoids on particle transport

    SciTech Connect

    Gu, X.; Okamura, M.; Pikin, A.; Fischer, W.; Luo, Y.

    2011-02-01

    Solenoids are widely used to transport or focus particle beams. Usually, they are assumed as being ideal solenoids with a high axial-symmetry magnetic field. Using the Vector Field Opera program, we modeled asymmetrical solenoids with realistic geometry defects, caused by finite conductor and current jumpers. Their multipole magnetic components were analyzed with the Fourier fit method; we present some possible optimized methods for them. We also discuss the effects of 'realistic' solenoids on low energy particle transport. The finding in this paper may be applicable to some lower energy particle transport system design.

  14. Magnetic field measurements of the superEBIS superconducting magnet. Informal report

    SciTech Connect

    Herschcovitch, A.; Kponou, A.; Clipperton, R.; Hensel, W.; Usack, F.

    1994-06-02

    SuperEBIS was designed to have a solenoidal magnetic field of a 5 Tesla strength with a 120 cm long bore. The field was specified to be straight within 1 part in 10000 within the bore, and uniform to within 1 part in 1000 within the central 90 cm. Magnetic field measurements were performed with a computerized magnetic field measuring setup that was borrowed from W. Sampson`s group. A preliminary test was made of a scheme to determine if the magnetic and mechanical axes of the solenoid coincided, and, if not, by how much.

  15. HIGH-RESOLUTION SOLENOID COIL NUCLEAR MAGNETIC RESONANCE PROBE FOR SUPERCONDUCTING MAGNET SPECTROMETERS

    EPA Science Inventory

    A broadband probe having a tuning range of 20 to 65 MHz has been designed and built specifically to give maximum sensitivity per unit volume of sample. This is accomplished through use of a solenoid rf coil instead of the usual Helmholtz coil found in commercial probes for superc...

  16. A design of novel type superconducting magnet for super-high field functional magnetic resonance imaging by using the harmonic analysis method of magnetic vector potentials

    NASA Astrophysics Data System (ADS)

    Zu, Dong-Lin; Guo, Hua; Song, Xiao-Yu; Bao, Shang-Lian

    2002-10-01

    The approach of expanding the magnetic scalar potential in a series of Legendre polynomials is suitable for designing a conventional superconducting magnetic resonance imaging magnet of distributed solenoidal configuration. Whereas the approach of expanding the magnetic vector potential in associated Legendre harmonics is suitable for designing a single-solenoid magnet that has multiple tiers, in which each tier may have multiple layers with different winding lengths. A set of three equations to suppress some of the lowest higher-order harmonics is found. As an example, a 4T single-solenoid magnetic resonance imaging magnet with 4×6 layers of superconducting wires is designed. The degree of homogeneity in the 0.5m diameter sphere volume is better than 5.8 ppm. The same degree of homogeneity is retained after optimal integralization of turns in each correction layer. The ratio Bm/B0 in the single-solenoid magnet is 30% lower than that in the conventional six-solenoid magnet. This tolerates higher rated superconducting current in the coil. The Lorentz force of the coil in the single-solenoid system is also much lower than in the six-solenoid system. This novel type of magnet possesses significant advantage over conventional magnets, especially when used as a super-high field functional magnetic resonance imaging magnet.

  17. Investigation of effect of solenoid magnet on emittances of ion beam from laser ablation plasma.

    PubMed

    Ikeda, Shunsuke; Romanelli, Mark; Cinquegrani, David; Sekine, Megumi; Kumaki, Masafumi; Fuwa, Yasuhiro; Kanesue, Takeshi; Okamura, Masahiro; Horioka, Kazuhiko

    2014-02-01

    A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ion beams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface. PMID:24593624

  18. Investigation of effect of solenoid magnet on emittances of ion beam from laser ablation plasma

    NASA Astrophysics Data System (ADS)

    Ikeda, Shunsuke; Romanelli, Mark; Cinquegrani, David; Sekine, Megumi; Kumaki, Masafumi; Fuwa, Yasuhiro; Kanesue, Takeshi; Okamura, Masahiro; Horioka, Kazuhiko

    2014-02-01

    A magnetic field can increase an ion current of a laser ablation plasma and is expected to control the change of the plasma ion current. However, the magnetic field can also make some fluctuations of the plasma and the effect on the beam emittance and the emission surface is not clear. To investigate the effect of a magnetic field, we extracted the ion beams under three conditions where without magnetic field, with magnetic field, and without magnetic field with higher laser energy to measure the beam distribution in phase space. Then we compared the relations between the plasma ion current density into the extraction gap and the Twiss parameters with each condition. We observed the effect of the magnetic field on the emission surface.

  19. Solenoid and monocusp ion source

    SciTech Connect

    Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

    1995-12-31

    An ion source which generates ions having high atomic purity incorporates a solenoidal magnetic field to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures.

  20. Expanding Non-solenoidal Startup with Local Helicity Injection to Increased Toroidal Field and Helicity Injection Rate

    NASA Astrophysics Data System (ADS)

    Perry, J. M.; Barr, J. L.; Bodner, G. M.; Bongard, M. W.; Burke, M. G.; Fonck, R. J.; Hinson, E. T.; Lewicki, B. T.; Reusch, J. A.; Schlossberg, D. J.; Winz, G. R.

    2015-11-01

    Local helicity injection (LHI) is a non-solenoidal startup technique under development on the Pegasus ST. Plasma currents up to 0.18 MA have been initiated by LHI in conjunction with poloidal field induction. A 0-D power balance model has been developed to predict plasma current evolution by balancing helicity input against resistive dissipation. The model is being validated against a set of experimental measurements and magnetic reconstructions with radically varied plasma geometric evolutions. Outstanding physics issues with LHI startup are the scalings of confinement and MHD activity with helicity injection rate and toroidal field strength, as well as injector behavior at high field. Preliminary results from the newly-installed Thomson scattering system suggest core temperatures of a few hundred eV during LHI startup. Measurements are being expanded to multiple spatial points for ongoing confinement studies. A set of larger-area injectors is being installed in the lower divertor region, where increased toroidal field will provide a helicity injection rate over 3 times that of outboard injectors. In this regime helicity injection will be the dominant current drive. Experiments with divertor injectors will permit experimental differentiation of several possible confinement models, and demonstrate the feasibility of LHI startup at high field. Work supported by US DOE grant DE-FG02-96ER54375.

  1. D-zero rototrack: first stage of D-zero 2 Tesla solenoid field mapping device

    SciTech Connect

    Yamada, R.; Korienek, J.; Krider, J.; Lindenmeyer, C.; Miksa, D.; Miksa, R.

    1997-09-01

    A simple and portable field mapping device was developed at Fermilab and successfully used to test the D0 2 Tesla solenoid at Toshiba Works in Japan. A description of the mechanical structure, electric driving and control system, and software of the field mapping device is given. Four Hall probe elements of Group3 Digital Gaussmeters are mounted on the radial extension arm of a carriage, which is mounted on a central rotating beam. The system gives two dimensional motions (axial and rotational) to the Hall probes. To make the system compact and portable, we used a laptop computer with PCMCIA cards. For the control system we used commercially available software LabVIEW and Motion Toolbox, and for the data analysis we used Microsoft Excel.

  2. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    NASA Astrophysics Data System (ADS)

    Teng, J.; Gu, Y. Q.; Zhu, B.; Hong, W.; Zhao, Z. Q.; Zhou, W. M.; Cao, L. F.

    2013-11-01

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

  3. Solenoid and monocusp ion source

    SciTech Connect

    Brainard, John Paul; Burns, Erskine John Thomas; Draper, Charles Hadley

    1997-01-01

    An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures.

  4. Bent Superconducting Solenoids for the Muon Cooling Experiment

    SciTech Connect

    Green, M.A.; Eyssa, Y.; Kenney, S.; Miller, J. R.; Prestemon, S.; Wang, S.T.

    1999-03-18

    This report describes some solenoid design work done for the cooling experiment for the muon collider collaboration. This report describes an analysis section of superconducting solenoids that have a center line induction of 3.0 T. The section is bent in the shape of an S. Each bend in the S bends the muon beam one radian (57.3 degrees). The warm bore diameter of the solenoid bent solenoid is 300 to 320 mm. The radius of the bend at the solenoid center line is 1000 mm. This report shows the results of three dimensional field calculations and presents a solenoid design that will include four TPC detectors that are 240 mm in diameter and 550 mm long as well as a 1300 mm long section of 1300 MHz RF cavities. The TPC sections need a solenoid wann bore diameter of about 300 320 mm while RF cavities require a warm bore diameter of 440 mm. The superconducting solenoid design must take into account the varying warm bore diameter requirements for the magnet string yet meet the stringent solenoidal field uniformity requirements within the active volume of the four TPCs.

  5. Mu2e production solenoid cryostat conceptual design

    SciTech Connect

    Nicol, T.H.; Kashikhin, V.V.; Page, T.M.; Peterson, T.J.; /Fermilab

    2011-06-01

    Mu2e is a muon-to-electron conversion experiment being designed by an international collaboration of more than 65 scientists and engineers from more than 20 research institutions for installation at Fermilab. The experiment is comprised of three large superconducting solenoid magnet systems, production solenoid (PS), transport solenoid (TS) and detector solenoid (DS). A 25 kW, 8 GeV proton beam strikes a target located in the PS creating muons from the decay of secondary particles. These muons are then focused in the PS and the resultant muon beam is transported through the TS towards the DS. The production solenoid presents a unique set of design challenges as the result of high radiation doses, stringent magnetic field requirements, and large structural forces. This paper describes the conceptual design of the PS cryostat and will include discussions of the vacuum vessel, thermal shield, multi-layer insulation, cooling system, cryogenic piping, and suspension system.

  6. Magnetic field sensor

    NASA Astrophysics Data System (ADS)

    Silva, Nicolas

    2012-09-01

    Earlier papers1-3 in this journal have described experiments on measuring the magnetic fields of current-carrying wires and permanent magnets using magnetic field probes of various kinds. This paper explains how to use an iPad and the free app MagnetMeter-3D Vector Magnetometer and Accelerometer4 (compass HD) to measure the magnetic fields.

  7. High magnetic fields at the Clarendon Laboratory, Oxford

    NASA Astrophysics Data System (ADS)

    Hudson, P. A.; Jones, H.; Whitworth, H. M.

    The Clarendon Laboratory in Oxford has been a centre for research in high magnetic fields for a number of years. The high-field facilities have been established around a 2MW do motorgenerator and today include a number of IOT solenoids which are energised by this machine as well as a hybrid resistive/superconductive magnet which is operated as an item of established laboratory equipment in which fields of 16T are routinely produced.

  8. How current loops and solenoids curve spacetime

    NASA Astrophysics Data System (ADS)

    Füzfa, André

    2016-01-01

    The curved spacetime around current loops and solenoids carrying arbitrarily large steady electric currents is obtained from the numerical resolution of the coupled Einstein-Maxwell equations in cylindrical symmetry. The artificial gravitational field associated to the generation of a magnetic field produces gravitational redshift of photons and deviation of light. Null geodesics in the curved spacetime of current loops and solenoids are also presented. We finally propose an experimental setup achievable with current technology of superconducting coils, that produces a phase shift of light of the same order of magnitude as astrophysical signals in ground-based gravitational wave observatories.

  9. Focusing solenoid for the front end of a linear RF accelerator

    SciTech Connect

    Terechkine, I.; Kashikhin, V.V.; Page, T.; Tartaglia, M.; Tompkins, J.; /Fermilab

    2007-06-01

    A prototype of a superconducting focusing solenoid for use in an RF linac has been built and tested at Fermi National Accelerator Laboratory (FNAL). The solenoid is comprised of the main coil, two bucking coils, two dipole corrector windings, and a low carbon steel flux return. At the excitation current of 250 A, the magnetic field reaches 7.2 T in the center of the solenoid and is less than 5 G on the axis at a distance of 150 mm from the center. The length of the solenoid is 150 mm; the length of a cryovessel for the solenoid with a 20 mm diameter 'warm' bore is 270 mm. This paper presents the main design features of the focusing solenoid and discusses results from tests of the solenoid.

  10. Numerical analyses of trapped field magnet and stable levitation region of HTSC

    SciTech Connect

    Tsuchimoto, M.; Kojima, T.; Waki, H.; Honma, T.

    1995-05-01

    Stable levitation with a permanent magnet and a bulk high {Tc} superconductor (HTSC) is examined numerically by using the critical state model and the frozen field model. Differences between a permanent magnet and a trapped field magnet are first discussed from property of levitation force. Stable levitation region of the HTSC on a ring magnet and on a solenoid coil are calculated with the numerical methods. Obtained results are discussed from difference of the magnetic field configuration.

  11. Hollow Plasma in a Solenoid

    SciTech Connect

    Anders, Andre; Kauffeldt, Marina; Oks, Efim M.; Roy, Prabir K.

    2010-11-30

    A ring cathode for a pulsed, high-current, multi-spot cathodic arc discharge was placed inside a pulsed magnetic solenoid. Photography is used to evaluate the plasma distribution. The plasma appears hollow for cathode positions close the center of the solenoid, and it is guided closer to the axis when the cathode is away from the center.

  12. A Magnetic Paradox

    ERIC Educational Resources Information Center

    Arndt, Ebe

    2006-01-01

    Two recent articles in this journal described how an air core solenoid connected to an ac power source may restore the magnetization of a bar magnet with an alternating magnetic field (see Figs. 1 and 2). Although we are quite accustomed to using a constant magnetic field in an air core solenoid to remagnetize a ferromagnet, it is puzzling that we…

  13. High intensity neutrino source superconducting solenoid cyrostat design

    SciTech Connect

    Page, T.M.; Nicol, T.H.; Feher, S.; Terechkine, I.; Tompkins, J.; /Fermilab

    2006-06-01

    Fermi National Accelerator Laboratory (FNAL) is involved in the development of a 100 MeV superconducting linac. This linac is part of the High Intensity Neutrino Source (HINS) R&D Program. The initial beam acceleration in the front end section of the linac is achieved using room temperature spoke cavities, each of which is combined with a superconducting focusing solenoid. These solenoid magnets are cooled with liquid helium at 4.5K, operate at 250 A and have a maximum magnetic field strength of 7.5 T. The solenoid cryostat will house the helium vessel, suspension system, thermal shield, multilayer insulation, power leads, instrumentation, a vacuum vessel and cryogenic distribution lines. This paper discusses the requirements and detailed design of these superconducting solenoid cryostats.

  14. Design of pulsed guiding magnetic field for high power microwave generators.

    PubMed

    Ju, J-C; Zhang, H; Zhang, J; Shu, T; Zhong, H-H

    2014-09-01

    In this paper, we present a comprehensive study on designing solenoid together with the corresponding power supply system to excite pulsed magnetic field required for high power microwave generators. Particularly, a solenoid is designed and the excited magnetic field is applied to a Ku-band overmoded Cerenkov generator. It is found in experiment that the electron beam is properly guided by the magnetic field and a 1.1 GW high power microwave is achieved at a central frequency of 13.76 GHz. Pulsed solenoid system has the advantages of compactness and low energy consumption, which are of great interest for repetitive operation. The reported studies and results can be generalized to other applications which require magnetic fields. PMID:25273750

  15. Design of pulsed guiding magnetic field for high power microwave generators

    SciTech Connect

    Ju, J.-C. Zhang, H.; Zhang, J.; Shu, T.; Zhong, H.-H.

    2014-09-15

    In this paper, we present a comprehensive study on designing solenoid together with the corresponding power supply system to excite pulsed magnetic field required for high power microwave generators. Particularly, a solenoid is designed and the excited magnetic field is applied to a Ku-band overmoded Cerenkov generator. It is found in experiment that the electron beam is properly guided by the magnetic field and a 1.1 GW high power microwave is achieved at a central frequency of 13.76 GHz. Pulsed solenoid system has the advantages of compactness and low energy consumption, which are of great interest for repetitive operation. The reported studies and results can be generalized to other applications which require magnetic fields.

  16. Photospheric magnetic fields

    NASA Technical Reports Server (NTRS)

    Howard, R.

    1972-01-01

    Knowledge on the nature of magnetic fields on the solar surface is reviewed. At least a large part of the magnetic flux in the solar surface is confined to small bundles of lines of force within which the field strength is of the order of 500 gauss. Magnetic fields are closely associated with all types of solar activity. Magnetic flux appears at the surface at the clearly defined birth or regeneration of activity of an active region. As the region ages, the magnetic flux migrates to form large-scale patterns and the polar fields. Some manifestations of the large-scale distribution are discussed.

  17. The ESRF Miniature Pulsed Magnetic Field System

    SciTech Connect

    Linden, Peter J. E. M. van der; Strohm, Cornelius; Roth, Thomas; Detlefs, Carsten; Mathon, Olivier

    2010-06-23

    We have developed a portable system to provide pulsed magnetic fields on the ESRF X-ray beamlines. The complete system consists of a power supply, liquid Helium and liquid Nitrogen dewars with a siphon each, control electronics and a double cryostat for separate coil and sample cooling. The liquid nitrogen cooled solenoids reach a maximum field of 30 Tesla for a total pulse duration of one milisecond. They are constructed for optimised cooling rate after the pulse to obtain a high duty cycle, the repetition rate is five pulses per minute at maximum field. The sample is cooled in an independent Helium flow cryostat which is inserted into the bore of the magnet. The flow cryostat has a temperature range from 5 to 250 Kelvin with a direct contact between the sample and Helium flow. This overview gives a general presentation of the system and we will show recent results.

  18. The ESRF Miniature Pulsed Magnetic Field System

    NASA Astrophysics Data System (ADS)

    van der Linden, Peter J. E. M.; Strohm, Cornelius; Roth, Thomas; Detlefs, Carsten; Mathon, Olivier

    2010-06-01

    We have developed a portable system to provide pulsed magnetic fields on the ESRF X-ray beamlines. The complete system consists of a power supply, liquid Helium and liquid Nitrogen dewars with a siphon each, control electronics and a double cryostat for separate coil and sample cooling. The liquid nitrogen cooled solenoids reach a maximum field of 30 Tesla for a total pulse duration of one milisecond. They are constructed for optimised cooling rate after the pulse to obtain a high duty cycle, the repetition rate is five pulses per minute at maximum field. The sample is cooled in an independent Helium flow cryostat which is inserted into the bore of the magnet. The flow cryostat has a temperature range from 5 to 250 Kelvin with a direct contact between the sample and Helium flow. This overview gives a general presentation of the system and we will show recent results.

  19. Progress on the Design and Fabircation of the MICE SpectrometerSolenoids

    SciTech Connect

    Virostek, S.P.; Green, M.A.; Lia, D.; Sizman, M.S.

    2007-06-20

    The Muon Ionization Cooling Experiment (MICE) willdemonstrate ionization cooling in a short section of a realistic coolingchannel using a muon beam at Rutherford Appleton Laboratory (RAL) in theUK. A five-coil, superconducting spectrometer solenoid magnet at each endof the cooling channel will provide a 4 T uniform field region for thescintillating fiber tracker within the magnet bore tubes. The trackermodules are used to measure the muon beam emittance as it enters andexits the cooling channel. The cold mass for the 400 mm warm bore magnetconsists of two sections: a three-coil spectrometer magnet and a two-coilmatching section that matches the uniform field of the solenoid into theMICE cooling channel. The spectrometer solenoid detailed designandanalysis has been completed, and the fabrication of the magnets is wellunder way. The primary features of the spectrometer solenoid magnet andmechanical designs are presented along with a summary of key fabricationissues and photos of the construction.

  20. Changes made on a 2.7-m long superconducting solenoid magnet cryogenic system that allowed the magnet to be kept cold using 4 K pulse tube coolers

    SciTech Connect

    Green, M. A.; Pan, H.; Preece, R. M.

    2014-01-29

    Two 2.7-m long solenoid magnets with a cold mass of 1400 kg were fabricated in between 2007 and 2010. The magnet cryostat outside diameter is ∼1.4 meters and the cryostat length is ∼2.73 meters. The magnet warm bore is 0.4 meters. The magnet was designed to be cooled using three 1.5 W two-stage coolers. In both magnets, three coolers could not keep the cryostat filled with liquid helium. The temperatures of the shield and the tops of the HTS leads were too warm. A 140 W single stage cooler was added to magnet 2 to cool the HTS leads, the shield and the cold mass support intercepts. When the magnet 2 was retested in 2010, the net cooling at 4.2 K was −1.5 W with first-stage temperatures of the four coolers at ∼42 K. The tops of the HTS leads were <50 K, but the shield and cold mass support intercepts remained too warm. The solenoid cryostat and shield were modified during 2011 and 2012 to reduce the 4.2 K heat load and increase the cooling. This magnet was tested in 2012, with five 1.5 W two-stage coolers and the single stage cooler. The changes made in the magnet are described in this report. As a result of the cryostat and shield changes, and adding 3.0 W of cooling at 4.2 K, the net 4.2 K cooling changed from −1.6 W to +5.0 W. About half of the change in net cooling to this magnet was due changes that reduced the shield temperature. This report demonstrates the importance of running the shield cold (∼40 K) and reducing the heat loads from all sources on both the shield and the cold mass.

  1. Magnetic field generator

    DOEpatents

    Krienin, Frank

    1990-01-01

    A magnetic field generating device provides a useful magnetic field within a specific retgion, while keeping nearby surrounding regions virtually field free. By placing an appropriate current density along a flux line of the source, the stray field effects of the generator may be contained. One current carrying structure may support a truncated cosine distribution, and it may be surrounded by a current structure which follows a flux line that would occur in a full coaxial double cosine distribution. Strong magnetic fields may be generated and contained using superconducting cables to approximate required current surfaces.

  2. On Cosmic Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Florido, E.; Battaner, E.

    2010-12-01

    Magnetic fields are present in all astrophysical media. However, many models and interpretations of observations often ignore them, because magnetic fields are difficult to handle and because they produce complicated morphological features. Here we will comment on the basic intuitive properties, which even if not completely true, provide a first guiding insight on the physics of a particular astrophysical problem. These magnetic properties are not mathematically demonstrated here. How magnetic fields evolve and how they introduce dynamical effects are considered, also including a short comment on General Relativity Magnetohydrodynamics. In a second part we consider some audacious and speculative matters. They are answers to three questions: a) How draw a cube without lifting the pencil from the paper so that when the pen passes through the same side do in the same direction? B) Are MILAGRO anisotropies miraculous? C) Do cosmic magnetic lenses exist?. The last two questions deal with issues related with the interplay between magnetic fields and cosmic ray propagation.

  3. Linear Coupling for B-Factory Tilted Solenoid

    SciTech Connect

    Fedotov, A.

    2005-02-16

    In this thesis they have presented the transfer matrix for B Factory tilted solenoid with the expansion of magnetic field up to the fifth order. Starting with the general theory of linear coupling, we got the Hamiltonian for solenoid with the bending magnet and quadrupole inside. The solenoid axis is tilted by 20 mrad horizontally w.r.t. the collision axis and at the entrance and the exit of the solenoid the beam will sense transverse and longitudinal non-linear fields. To account both this effects the expansion of the magnetic field was done. The code of coordinate transformation, which relates the frame of the reference orbit to the frame of the collision axis and to the solenoid frame, has been introduced. They tried to show that not symplectic fourth-order Runge Kutta integration method, which had been used for integration of the Hamiltonian equations, might be used as a model for ''not tracking'' problems. The deviation from a symplectic transfer matrix is smaller than 10{sup -5}. Using the transfer matrix, the change in beam shape and blow up of emittance, due to the solenoid coupling, was discussed. In order to compensate this effect they used 4 tilted quadrupoles on each side of the IP. The method based on the Hamiltonian in Eq.19 integrates along a reference orbit which is defined only by the horizontal and vertical bending fields and not by the tilted solenoid. In order to get the Hamiltonian, which is associated with a non-planar curvature of the reference orbit, it is necessary to account the effect of torsion. In that case the transformation between the three different coordinate systems will become more complicated.

  4. Magnetic Fields in Galaxies

    NASA Astrophysics Data System (ADS)

    Beck, Rainer

    Magnetic fields are a major agent in the interstellar medium. They contribute significantly to the total pressure which balances the gas disk against gravitation. They affect the gas flows in spiral arms (Gómez and Cox, 2002). The effective sound speed of the gas is increased by the presence of strong fields which reduce the shock strength. The interstellar fields are closely connected to gas clouds. They affect the dynamics of the gas clouds (Elmegreen, 1981; de Avillez and Breitschwerdt, 2004). The stability and evolution of gas clouds are also influenced by magnetic fields, but it is not understood how (Crutcher, 1999; see Chap. 7). Magnetic fields are essential for the onset of star formation as they enable the removal of angular momentum from the protostellar cloud during its collapse (magnetic braking, Mouschovias, 1990). Strong fields may shift the stellar mass spectrum towards the more massive stars (Mestel, 1990). MHD turbulence distributes energy from supernova explosions within the ISM (Subramanian, 1998) and regenerates the field via the dynamo process (Wielebinski, R., Krause, 1993, Beck et al., 1996; Sect. 6). Magnetic reconnection is a possible heating source for the ISM and halo gas (Birk et al., 1998). Magnetic fields also control the density and distribution of cosmic rays in the ISM. A realistic model for any process in the ISM needs basic information about the magnetic field which has to be provided by observations.

  5. Determining if an axially rotated solenoid will induce a radial EMF

    NASA Astrophysics Data System (ADS)

    MacDermott, Dustin R.

    The nature of the electromagnetic field of an axially rotated solenoid or magnet is investigated. The investigations reviewed suggest the possibility of a radially emitted electric field by either: axially rotated magnetic field lines, or a relativistic change in charge of the electron. For a very long solenoid a relativistic change in charge leaves no electric field inside while leaving an electric field outside. The concept of axially rotating magnetic field lines gives an opposite prediction. They both seem to be in contradiction to the standard model of induction, which gives no change in the electric field for a rotated solenoid or magnet. An experiment by Joseph B. Tate [48], [49] conducted in 1968 seemed to have measured a change in charge outside of a rotated solenoid. Another experiment by Barnett [3] in 1912 reported measuring no electric field inside of a rotated solenoid. Further experimentation was decided necessary and the method decided upon to attempt detection of the radial E or EMF induced by an axially rotating B field or change in charge is two concentric capacitor plates, one inside and the other outside an axially rotated solenoid. The solenoid was rotated on a lathe for the test. A concentric capacitor around an axially rotated permanent neodymium magnet was also used as a test. These experiments proved very challenging because of the small magnitude of the predicted effect. Nevertheless, the bulk of the evidence obtained indicates that no induced E arises when a magnetic source is rotated about its magnetic axis, thus supporting the standard field model of electromagnetic induction, and casting doubt on the alternative theories of magnetic field line rotation or relativistic charge enhancement.

  6. A new generation of superconducting solenoids for heavy-ion linac application.

    SciTech Connect

    Ostroumov, P. N.; Kim, S. H.; Lessner, E. S.; Shepard, K. W.; Laxdal, R. E.; Wheatley, R.

    2002-08-22

    The beam dynamics of superconducting (SC) heavy-ion linacs operating in the velocity range below 0.4c require a compact accelerating-focusing lattice. The use of SC solenoids together with SC RF resonators within a common cryostat can solve the real-estate problem. The solenoids must have low fringe fields to avoid magnetic flux capture in the SC RF resonators. Also, incorporating dipole steering coils together with the SC solenoids in one magnet assembly can increase the compactness of the linac lattice. R&D work has been carried out to determine the feasibility of combining the three elements of high solenoid field, low fringe field, and integral dipole field, into one compact package. A 9-Tesla magnet has been initially designed and will be prototyped, with the goal of eventually developing 14-Tesla solenoids of similar design. The most important design issues are: (1) to minimize stray field in the RF cavity region using SC bucking coils and (2) to achieve adequate mechanical stability of the transverse dipole windings in the presence of forces produced by the solenoid/bucking coil assembly. The assembly, including terminals, switches, and protection circuit, are designed to fit inside a 25-cm diameter helium reservoir. The results of the preliminary design of the solenoid, including numerical simulations of the beam dynamics, are reported.

  7. New Generation of Superconducting Solenoids for Heavy-Ion Linac Application

    NASA Astrophysics Data System (ADS)

    Ostroumov, P. N.; Kim, S. H.; Lessner, E. S.; Shepard, K. W.; Laxdal, R. E.

    2002-01-01

    The beam dynamics of superconducting (SC) heavy-ion linacs operating in the velocity range below 0.4c require a compact accelerating-focusing lattice. The use of SC solenoids together with SC RF resonators within a common cryostat can solve the real-estate problem. The solenoids must have low fringe fields to avoid magnetic-flux capture in the SC RF resonators. Also, incorporating dipole steering coils together with the SC solenoids in one magnet assembly can increase the compactness of the linac lattice. R&D work has been carried out to determine the feasibility of combining the three elements of high solenoid field, low fringe field, and integral dipole field, into one compact package. A 9-Tesla magnet has been initially designed and will be prototyped, with the goal of eventually developing 14-Tesla solenoids of similar design. The most important design issues are: (1) to minimize stray field in the RF cavity region using SC bucking coils and (2) to achieve adequate mechanical stability of the transverse dipole windings in the presence of forces produced by the solenoid/bucking coil assembly. The assembly, including terminals, switches, and protection circuit, are designed to fit inside a 25-cm diameter helium reservoir. The results of the preliminary design of the solenoid, including numerical simulations of the beam dynamics, are reported.

  8. SU-E-J-233: A Facility for Radiobiological Experiments in a Large Magnetic Field

    SciTech Connect

    Carlone, M; Heaton, R; Keller, H; Wouters, B; Jaffray, D

    2014-06-01

    Purpose: There is considerable interest in developing medical linear accelerators with integrated image guidance by MRI. Less work has been done on the fundamental biology of cell survival in the presence of a strong magnetic field. The purpose of this work is to describe an experimental system capable of measuring cell survival response in the types of MRI-linac systems currently under development. Methods: We have integrated a cobalt irradiator with a solenoid magnet. The solenoid magnet has inner diameter of 10 cm. To enable measurement of the biological effects as a function of depth, we are utilizing the sliced gel technique, in which cells are embedded and fixed within a gelatin matrix. Irradiated cells at defined positions (sub mm resolution) can subsequently be recovered and assessed for cell survival or other biological effects. Results: The magnetic field profile in the solenoid has a peak magnetic field 36 cm below the top edge of the magnet bore and can be placed at and SAD of 100 cm. At a solenoid current of 35 A, the peak magnetic field is 0.25 T. The dose rate of the cobalt irradiator is 16 cGy/min at 100 cm SAD. EBT3 film was used to demonstrate the system functionality. It was irradiated at 1 cm depth at 100 cm SSD with a 4×4 field to 1.5 Gy in a 0.25 T magnetic field. The dose profile was similar between this film and the control exposure without magnetic field. Conclusion: Integrating a cobalt irradiator with a high field magnet is demonstrated. The magnetic field at the cobalt defining head was minimal and did not interfere with the functioning of this unit. Cell survival experiments can be reproduced exactly in the presence or absence of a magnetic field since a resistive magnet is used.

  9. Fabrication, Testing and Modeling of the MICE Superconducting Spectrometer Solenoids

    SciTech Connect

    Virostek, S.P.; Green, M.A.; Trillaud, F.; Zisman, M.S.

    2010-05-16

    The Muon Ionization Cooling Experiment (MICE), an international collaboration sited at Rutherford Appleton Laboratory in the UK, will demonstrate ionization cooling in a section of realistic cooling channel using a muon beam. A five-coil superconducting spectrometer solenoid magnet will provide a 4 tesla uniform field region at each end of the cooling channel. Scintillating fiber trackers within the 400 mm diameter magnet bore tubes measure the emittance of the beam as it enters and exits the cooling channel. Each of the identical 3-meter long magnets incorporates a three-coil spectrometer magnet section and a two-coil section to match the solenoid uniform field into the other magnets of the MICE cooling channel. The cold mass, radiation shield and leads are currently kept cold by means of three two-stage cryocoolers and one single-stage cryocooler. Liquid helium within the cold mass is maintained by means of a re-condensation technique. After incorporating several design changes to improve the magnet cooling and reliability, the fabrication and acceptance testing of the spectrometer solenoids have proceeded. The key features of the spectrometer solenoid magnets, the development of a thermal model, the results of the recently completed tests, and the current status of the project are presented.

  10. Symplectic tracking using point magnets in the presence of a longitudinal magnetic field

    SciTech Connect

    Parzen, G.

    1993-09-01

    In the absence of a longitudinal magnetic field, symplectic tracking can be achieved by replacing the magnets by a series of point magnets and drift spaces. To treat the case when a longitudinal magnetic field is also present, this procedure is modified in this paper by replacing the drift space by a solenoidal drift, which is defined as the motion of a particle in a uniform longitudinal magnetic field. A symplectic integrator can be obtained by subdividing each magnet into pieces and replacing each magnet piece by point magnets, with only transverse fields, and solenoidal drift spaces. The reference orbit used here is made up of arcs of circles and straight lines which join smoothly with each other. For this choice of reference orbit, the required results are obtained to track particles, which are the transfer functions, and the transfer time for the different elements. It is shown that these results provide a symplectic integrator, and they are exact in the sense that as the number of magnet pieces is increased, the particle motion will converge to the particle motion of the exact equations of motion.

  11. Numerical Simulations for the Design of a Magnetoplasmadynamic Thruster with Coaxial Applied Magnetic Field

    NASA Astrophysics Data System (ADS)

    Haag, D.; Auweter-Kurtz, M.; Fertig, M.

    2004-10-01

    In this paper, the plasma flow in applied field magneto-plasmadynamic (AFMPD) thrusters is described by conservation equations for heavy particles, electrons and the magnetic field for thermal and chemical non-equilibrium. To take into account the effects of the applied magnetic field a quasi-three dimensional approach with vanishing azimuthal derivatives is used for the velocity and magnetic field. The vector potential formulation has been chosen for the description of the applied magnetic field to handle the influences of solenoidal coils and induced azimuthal current density on the magnetic field. The numerical scheme is based on a two-dimensional, axisymmetric finite volume method on unstructured, adaptive meshes.

  12. Magnetic field dosimeter development

    SciTech Connect

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1980-09-01

    In recent years there has been increased concern over potential health hazards related to exposure of personnel to magnetic fields. If exposure standards are to be established, then a means for measuring magnetic field dose must be available. To meet this need, the Department of Energy has funded development of prototype dosimeters at the Battelle Pacific Northwest Laboratory. This manual reviews the principle of operation of the dosimeter and also contains step-by-step instructions for its operation.

  13. Magnetic fields in spiral galaxies

    NASA Astrophysics Data System (ADS)

    Chiba, Masashi

    The magnetic-field characteristics in spiral galaxies are investigated, with emphasis on the Milky Way. The dynamo theory is considered, and axisymmetric spiral (ASS) and bisymmetric spiral (BSS) magnetic fields are analyzed. Toroidal and poloidal magnetic fields are discussed.

  14. Solar Wind Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Smith, E. J.

    1995-01-01

    The magnetic fields originate as coronal fields that are converted into space by the supersonic, infinitely conducting, solar wind. On average, the sun's rotation causes the field to wind up and form an Archimedes Spiral. However, the field direction changes almost continuously on a variety of scales and the irregular nature of these changes is often interpreted as evidence that the solar wind flow is turbulent.

  15. Open Cavity Solutions to the rf in Magnetic Field Problem

    NASA Astrophysics Data System (ADS)

    Palmer, Robert B.; Berg, J. Scott; Fernow, Richard C.; Gallardo, Juan C.; Kirk, Harold G.

    2008-02-01

    It has been observed [1] that breakdown in an 805 MHz pill-box cavity occurs at much lower gradients as an external axial magnetic field is increased. This effect was not observed with on open iris cavity. It is proposed that this effect depends on the relative angles of the magnetic and maximum electric fields: parallel in the pill-box case; at an angle in the open iris case. If so, using an open iris structure with solenoid coils in the irises should perform even better. A lattice, using this principle, is presented, for use in 6D cooling for a Muon Collider. Experimental layouts to test this principle are proposed.

  16. OPEN CAVITY SOLUTIONS TO THE RF IN MAGNETIC FIELD PROBLEM.

    SciTech Connect

    PALMER,R.B.; BERG, J.S.; FERNOW, R.C.; GALLARDO, J.C.; KIRK, H.G.

    2007-08-06

    It has been observed [1] that breakdown in an 805 MHz pill-box cavity occurs at much lower gradients as an external axial magnetic field is increased. This effect was not observed with on open iris cavity. It is proposed that this effect depends on the relative angles of the magnetic and maximum electric fields: parallel in the pill-box case; at an angle in the open iris case. If so, using an open iris structure with solenoid coils in the irises should perform even better. A lattice, using this principle, is presented, for use in 6D cooling for a Muon Collider. Experimental layouts to test this principle are proposed.

  17. Ferrofluidic solenoid

    NASA Technical Reports Server (NTRS)

    Sabelman, E. E. (Inventor)

    1973-01-01

    An electromechanical actuator for producing mechanical force and/or motion in response to electrical signals is disclosed. The actuator includes a ferromagnetic fluid and a coil which are contained within an elastomeric capsule. Energization of the coil by application of current to a pair of coil electrodes extending through the walls of the elastomeric capsule produces distortion of the capsule, i.e., radial expansion and axial contraction. This distortion is caused by the redistribution of the ferromagnetic fluid within the capsule under the influence of the magnetic field. Variation of the current input will produce corresponding variations in the degree of capsule distortion.

  18. Magnetic Field Measurement System

    SciTech Connect

    Kulesza, Joe; Johnson, Eric; Lyndaker, Aaron; Deyhim, Alex; Waterman, Dave; Blomqvist, K. Ingvar; Dunn, Jonathan Hunter

    2007-01-19

    A magnetic field measurement system was designed, built and installed at MAX Lab, Sweden for the purpose of characterizing the magnetic field produced by Insertion Devices (see Figure 1). The measurement system consists of a large granite beam roughly 2 feet square and 14 feet long that has been polished beyond laboratory grade for flatness and straightness. The granite precision coupled with the design of the carriage yielded minimum position deviations as measured at the probe tip. The Hall probe data collection and compensation technique allows exceptional resolution and range while taking data on the fly to programmable sample spacing. Additional flip coil provides field integral data.

  19. Magnetic Field Solver

    NASA Technical Reports Server (NTRS)

    Ilin, Andrew V.

    2006-01-01

    The Magnetic Field Solver computer program calculates the magnetic field generated by a group of collinear, cylindrical axisymmetric electromagnet coils. Given the current flowing in, and the number of turns, axial position, and axial and radial dimensions of each coil, the program calculates matrix coefficients for a finite-difference system of equations that approximates a two-dimensional partial differential equation for the magnetic potential contributed by the coil. The program iteratively solves these finite-difference equations by use of the modified incomplete Cholesky preconditioned-conjugate-gradient method. The total magnetic potential as a function of axial (z) and radial (r) position is then calculated as a sum of the magnetic potentials of the individual coils, using a high-accuracy interpolation scheme. Then the r and z components of the magnetic field as functions of r and z are calculated from the total magnetic potential by use of a high-accuracy finite-difference scheme. Notably, for the finite-difference calculations, the program generates nonuniform two-dimensional computational meshes from nonuniform one-dimensional meshes. Each mesh is generated in such a way as to minimize the numerical error for a benchmark one-dimensional magnetostatic problem.

  20. Magnetic fields at neptune.

    PubMed

    Ness, N F; Acuña, M H; Burlaga, L F; Connerney, J E; Lepping, R P; Neubauer, F M

    1989-12-15

    The National Aeronautics and Space Administration Goddard Space Flight Center-University of Delaware Bartol Research Institute magnetic field experiment on the Voyager 2 spacecraft discovered a strong and complex intrinsic magnetic field of Neptune and an associated magnetosphere and magnetic tail. The detached bow shock wave in the supersonic solar wind flow was detected upstream at 34.9 Neptune radii (R(N)), and the magnetopause boundary was tentatively identified at 26.5 R(N) near the planet-sun line (1 R(N) = 24,765 kilometers). A maximum magnetic field of nearly 10,000 nanoteslas (1 nanotesla = 10(-5) gauss) was observed near closest approach, at a distance of 1.18 R(N). The planetary magnetic field between 4 and 15 R(N) can be well represented by an offset tilted magnetic dipole (OTD), displaced from the center of Neptune by the surprisingly large amount of 0.55 R(N) and inclined by 47 degrees with respect to the rotation axis. The OTD dipole moment is 0.133 gauss-R(N)(3). Within 4 R(N), the magnetic field representation must include localized sources or higher order magnetic multipoles, or both, which are not yet well determined. The obliquity of Neptune and the phase of its rotation at encounter combined serendipitously so that the spacecraft entered the magnetosphere at a time when the polar cusp region was directed almost precisely sunward. As the spacecraft exited the magnetosphere, the magnetic tail appeared to be monopolar, and no crossings of an imbedded magnetic field reversal or plasma neutral sheet were observed. The auroral zones are most likely located far from the rotation poles and may have a complicated geometry. The rings and all the known moons of Neptune are imbedded deep inside the magnetosphere, except for Nereid, which is outside when sunward of the planet. The radiation belts will have a complex structure owing to the absorption of energetic particles by the moons and rings of Neptune and losses associated with the significant changes

  1. The Effect of Magnetic Field on the Position of HTS Leads and theCooler in the Services Tower of the MICE Focusing Magnet

    SciTech Connect

    Green, M.A.; Yang, S.Q.; Cobb, J.; Lau, P.; Lau, W.W.; Witte,H.; Baynham, D.E.; Bradshaw, T.W.

    2007-08-27

    The MICE focusing solenoids have three 4 K coolers (two forthe superconducting magnet and one for the liquid absorber) and four HTSleads that feed the current to the focusing coils. The focusing solenoidsproduce large radial external fields when they operate with the polarityof the two coils in opposition (the gradient or flip mode). When the MICEfocusing coils operate at the same polarity (the solenoid or non-flipmode), the fields are much smaller and parallel to the axis of thesolenoid. The worst-case magnetic field affects the selection of thecooler and the HTS leads. This magnetic field can also determine theheight of the service towers that house the three coolers and the fourHTS leads. This paper shows the criteria used for Cooler selection, HTSlead selection, and the position of both the cooler and leads withrespect to the solenoid axis of rotation.

  2. A Superconducting Solenoid for Heavy Ion Beam Focusing

    NASA Astrophysics Data System (ADS)

    Kim, J. W.; Kubo, Toshiyuki; Kawaguchi, Takeo; Imai, Yoshio; Minato, Tsuneaki; Seo, Kazutaka

    1997-05-01

    A superconducting solenoid has been constructed to use as a final focusing element at the entrance of the projectile fragment separator RIPS (T. Kubo et al, Nucl. Instr. & Meth. B70 (1992) 309) at RIKEN. The design field on axis is 6 tesla, the average current density being 9,600 A/cm^2. The overall coil length is 1.1 meter, and the coil is divided into three sections of equal length to ease winding and possibly to distribute the stored energy. A major feature of the magnet is that cooling is conductive without LHe involved, using a cryocooler directly attached onto the coil. The solenoid is currently being tested, and the test results will be presented. After magnet testing, the solenoid will be installed in the beamline. The results of beam experiment will also be presented, along with calculation results with TRANSPORT.

  3. Standing Helicon Wave Induced by a Rapidly Bent Magnetic Field in Plasmas.

    PubMed

    Takahashi, Kazunori; Takayama, Sho; Komuro, Atsushi; Ando, Akira

    2016-04-01

    An electron energy probability function and a rf magnetic field are measured in a rf hydrogen helicon source, where axial and transverse static magnetic fields are applied to the source by solenoids and to the diffusion chamber by filter magnets, respectively. It is demonstrated that the helicon wave is reflected by the rapidly bent magnetic field and the resultant standing wave heats the electrons between the source and the magnetic filter, while the electron cooling effect by the magnetic filter is maintained. It is interpreted that the standing wave is generated by the presence of a spatially localized change of a refractive index. PMID:27081982

  4. Nuclear Spin Maser at Highly Stabilized Low Magnetic Field and Search for Atomic EDM

    SciTech Connect

    Yoshimi, A.; Asahi, K.; Inoue, T.; Uchida, M.; Hatakeyama, N.; Tsuchiya, M.; Kagami, S.

    2009-08-04

    A nuclear spin maser is operated at a low static field through an active feedback scheme based on an optical nuclear spin detection and succeeding spin control by a transverse field application. The frequency stability of this optical-coupling spin maser is improved by installation of a low-noise current source for a solenoid magnet producing a static magnetic field in the maser operation. Experimental devices for application of the maser to EDM experiment are being developed.

  5. Rotating coil field measurement of superconducting magnet for BEPCII interaction region

    NASA Astrophysics Data System (ADS)

    Peng, Quanling; Ren, Fanglin; Yin, Baogui; Wu, Yingzhi; Dong, Lan; Sun, Zhirui

    2011-06-01

    Two multifunction superconducting magnets in the interaction region (IR) for Beijing electron positron collider upgrade project (BEPCII) have been measured in BESIII detector hall in 2007. Each superconducting magnet package contains multiple concentric layers with several function magnets called as a vertical focusing quadrupole (SCQ), a horizontal corrector (HDC/SCB), a vertical corrector (VDC), a skew quadrupole (SKQ) and three anti-solenoids (AS1, AS2 and AS3) to compensate the experimental detector solenoid field. All these function magnets SCQs, SCB/HDCs, VDCs and SKQs have been measured using two rotating coils. Their integral fields, their high order harmonics contents and the local fields along the beam line are obtained in detail with the rotating coil probe system. Comparing the results to the stretched wire, the differences for the integral fields are less than 0.2%. As a result, the method presented in this paper can be used as an absolute field measurement in our lab.

  6. Ultra-high field magnets for whole-body MRI

    NASA Astrophysics Data System (ADS)

    Warner, Rory

    2016-09-01

    For whole-body MRI, an ultra-high field (UHF) magnet is currently defined as a system operating at 7 T or above. Over 70 UHF magnets have been built, all with the same technical approach originally developed by Magnex Scientific Ltd. The preferred coil configuration is a compensated solenoid. In this case, the majority of the field is generated by a simple long solenoid that stretches the entire length of the magnet. Additional coils are wound on a separate former outside the main windings with the purpose of balancing the homogeneity. Most of the magnets currently in operation are passively shielded systems where the magnet is surrounded by a steel box of 200–870 tonnes of carbon steel. More recently actively shielded magnets have been built for operation at 7 T; in this case the stray field is controlled by with reverse turns wound on a separate former outside the primary coils. Protection against quench damage is much more complex with an actively shielded magnet design due to the requirement to prevent the stray field from increasing during a quench. In the case of the 7 T 900 magnet this controlled by combining some of the screening coils into each section of the protection circuit. Correction of the field variations caused by manufacturing tolerances and environmental effects are made with a combination of superconducting shims and passive shims. Modern UHF magnets operate in zero boil-off mode with the use of cryocoolers with cooling capacity at 4.2 K. Although there are no cryogen costs associated with normal operation UHF magnets require a significant volume (10 000–20 000 l) of liquid helium for the cool-down. Liquid helium is expensive therefore new methods of cool-down using high-power cryocoolers are being implemented to reduce the requirement.

  7. Magnetic Field Gradient Levitation System for Physics and Biophysics

    NASA Astrophysics Data System (ADS)

    Valles, James; Guevorkian, Karine

    2002-03-01

    We are developing a Magnetic Field Gradient Levitation (MFGL) apparatus as a ground based system for simulating a low or variable gravity environment for diamagnetic materials. The system consists of a superconducting solenoid with a room temperature bore that can generate a magnetic force strong enough to levitate or cancel the body force of gravity in common organic materials (e.g. water, proteins, polypropylene). We will describe the specifications and capabilities of the apparatus and our initial experimental studies of gravitational sensitivity in the biological systems, frog embryos and paramecium.

  8. Three dimensional multilayer solenoid microcoils inside silica glass

    NASA Astrophysics Data System (ADS)

    Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Si, Jinhai; Hou, Xun

    2016-01-01

    Three dimensional (3D) solenoid microcoils could generate uniform magnetic field. Multilayer solenoid microcoils are highly pursued for strong magnetic field and high inductance in advanced magnetic microsystems. However, the fabrication of the 3D multilayer solenoid microcoils is still a challenging task. In this paper, 3D multilayer solenoid microcoils with uniform diameters and high aspect ratio were fabricated in silica glass. An alloy (Bi/In/Sn/Pb) with high melting point was chosen as the conductive metal to overcome the limitation of working temperature and improve the electrical property. The inductance of the three layers microcoils was measured, and the value is 77.71 nH at 100 kHz and 17.39 nH at 120 MHz. The quality factor was calculated, and it has a value of 5.02 at 120 MHz. This approach shows an improvement method to achieve complex 3D metal microstructures and electronic components, which could be widely integrated in advanced magnetic microsystems.

  9. High field superconducting magnets

    NASA Technical Reports Server (NTRS)

    Hait, Thomas P. (Inventor); Shirron, Peter J. (Inventor)

    2011-01-01

    A superconducting magnet includes an insulating layer disposed about the surface of a mandrel; a superconducting wire wound in adjacent turns about the mandrel to form the superconducting magnet, wherein the superconducting wire is in thermal communication with the mandrel, and the superconducting magnet has a field-to-current ratio equal to or greater than 1.1 Tesla per Ampere; a thermally conductive potting material configured to fill interstices between the adjacent turns, wherein the thermally conductive potting material and the superconducting wire provide a path for dissipation of heat; and a voltage limiting device disposed across each end of the superconducting wire, wherein the voltage limiting device is configured to prevent a voltage excursion across the superconducting wire during quench of the superconducting magnet.

  10. The interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Davis, L., Jr.

    1972-01-01

    Large-scale properties of the interplanetary magnetic field as determined by the solar wind velocity structure are examined. The various ways in which magnetic fields affect phenomena in the solar wind are summarized. The dominant role of high and low velocity solar wind streams that persist, with fluctuations and evolution, for weeks or months is emphasized. It is suggested that for most purposes the sector structure is better identified with the stream structure than with the magnetic polarity and that the polarity does not necessarily change from one velocity sector to the next. Several mechanisms that might produce the stream structure are considered. The interaction of the high and low velocity streams is analyzed in a model that is steady state when viewed in a frame that corotates with the sun.

  11. Precise mapping of the magnetic field in the CMS barrel yoke using cosmic rays

    SciTech Connect

    Chatrchyan, S.; et al.,

    2010-03-01

    The CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location.

  12. Simulation of RF Cavity Dark Current in Presence of Helical Magnetic Field

    SciTech Connect

    Romanov, Gennady; Kashikhin, Vladimir; /Unlisted

    2010-09-01

    In order to produce muon beam of high enough quality to be used for a Muon Collider, its large phase space must be cooled several orders of magnitude. This task can be accomplished by ionization cooling. Ionization cooling consists of passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF cavities within a multi-Tesla solenoidal focusing channel. But first high power tests of RF cavity with beryllium windows in solenoidal magnetic field showed a dramatic drop in accelerating gradient due to RF breakdowns. It has been concluded that external magnetic fields parallel to RF electric field significantly modifies the performance of RF cavities. However, magnetic field in Helical Cooling Channel has a strong dipole component in addition to solenoidal one. The dipole component essentially changes electron motion in a cavity compare to pure solenoidal case, making dark current less focused at field emission sites. The simulation of dark current dynamic in HCC performed with CST Studio Suit is presented in this paper.

  13. Simulation of RF Cavity Dark Current In Presence of Helical Magnetic Field

    SciTech Connect

    Romanov, Gennady; Kashikhin, Vladimir; /Fermilab

    2012-05-01

    In order to produce muon beam of high enough quality to be used for a Muon Collider, its large phase space must be cooled several orders of magnitude. This task can be accomplished by ionization cooling. Ionization cooling consists of passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF cavities within a multi-Tesla solenoidal focusing channel. But first high power tests of RF cavity with beryllium windows in solenoidal magnetic field showed a dramatic drop in accelerating gradient due to RF breakdowns. It has been concluded that external magnetic fields parallel to RF electric field significantly modifies the performance of RF cavities. However, magnetic field in Helical Cooling Channel has a strong dipole component in addition to solenoidal one. The dipole component essentially changes electron motion in a cavity compare to pure solenoidal case, making dark current less focused at field emission sites. The simulation of dark current dynamic in HCC performed with CST Studio Suit is presented in this paper.

  14. BEAM-BASED ALIGNMENT IN THE RHIC E-COOLING SOLENOIDS.

    SciTech Connect

    CAMERON, P.; BEN-ZVI, I.; DAWSON, W.C.; ET AL.

    2005-05-16

    Accurate alignment of the electron and ion beams in the RHIC electron cooling solenoids is crucial for well-optimized cooling. Because of the greatly differing rigidities of the electron and ion beams, to achieve the specified alignment accuracy it is required that transverse magnetic fields resulting from imperfections in solenoid fabrication be down by five orders of magnitude relative to the pure solenoid fields. Shimming the solenoid field to this accuracy might be accomplished by survey techniques prior to operation with beam, or by methods of beam-based alignment. We report on the details of a method of beam-based alignment, as well as the results of preliminary measurements with the ion beam at RHIC.

  15. Crustal Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Taylor, Patrick T.; Ravat, D.; Frawley, James J.

    1999-01-01

    Cosmos 49, Polar Orbit Geophysical Observatory (POGO) (Orbiting Geophysical Observatory (OGO-2, 4 and 6)) and Magsat have been the only low-earth orbiting satellites to measure the crustal magnetic field on a global scale. These missions revealed the presence of long- wavelength (> 500 km) crustal anomalies predominantly located over continents. Ground based methods were, for the most part, unable to record these very large-scale features; no doubt due to the problems of assembling continental scale maps from numerous smaller surveys acquired over many years. Questions arose as to the source and nature of these long-wave length anomalies. As a result there was a great stimulant given to the study of the magnetic properties of the lower crust and upper mantle. Some indication as to the nature of these deep sources has been provided by the recent results from the deep crustal drilling programs. In addition, the mechanism of magnetization, induced or remanent, was largely unknown. For computational ease these anomalies were considered to result solely from induced magnetization. However, recent results from Mars Orbiter Laser Altimeter (MOLA), a magnetometer-bearing mission to Mars, have revealed crustal anomalies with dimensions similar to the largest anomalies on Earth. These Martian features could only have been produced by remanent magnetization, since Mars lacks an inducing field. The origin of long-wavelength crustal anomalies, however, has not been completely determined. Several large crustal magnetic anomalies (e.g., Bangui, Kursk, Kiruna and Central Europe) will be discussed and the role of future satellite magnetometer missions (Orsted, SUNSAT and Champ) in their interpretation evaluated.

  16. Magnetization dynamics using ultrashort magnetic field pulses

    NASA Astrophysics Data System (ADS)

    Tudosa, Ioan

    Very short and well shaped magnetic field pulses can be generated using ultra-relativistic electron bunches at Stanford Linear Accelerator. These fields of several Tesla with duration of several picoseconds are used to study the response of magnetic materials to a very short excitation. Precession of a magnetic moment by 90 degrees in a field of 1 Tesla takes about 10 picoseconds, so we explore the range of fast switching of the magnetization by precession. Our experiments are in a region of magnetic excitation that is not yet accessible by other methods. The current table top experiments can generate fields longer than 100 ps and with strength of 0.1 Tesla only. Two types of magnetic were used, magnetic recording media and model magnetic thin films. Information about the magnetization dynamics is extracted from the magnetic patterns generated by the magnetic field. The shape and size of these patterns are influenced by the dissipation of angular momentum involved in the switching process. The high-density recording media, both in-plane and perpendicular type, shows a pattern which indicates a high spin momentum dissipation. The perpendicular magnetic recording media was exposed to multiple magnetic field pulses. We observed an extended transition region between switched and non-switched areas indicating a stochastic switching behavior that cannot be explained by thermal fluctuations. The model films consist of very thin crystalline Fe films on GaAs. Even with these model films we see an enhanced dissipation compared to ferromagnetic resonance studies. The magnetic patterns show that damping increases with time and it is not a constant as usually assumed in the equation describing the magnetization dynamics. The simulation using the theory of spin-wave scattering explains only half of the observed damping. An important feature of this theory is that the spin dissipation is time dependent and depends on the large angle between the magnetization and the magnetic

  17. Coronal Magnetic Field Models

    NASA Astrophysics Data System (ADS)

    Wiegelmann, Thomas; Petrie, Gordon J. D.; Riley, Pete

    2015-07-01

    Coronal magnetic field models use photospheric field measurements as boundary condition to model the solar corona. We review in this paper the most common model assumptions, starting from MHD-models, magnetohydrostatics, force-free and finally potential field models. Each model in this list is somewhat less complex than the previous one and makes more restrictive assumptions by neglecting physical effects. The magnetohydrostatic approach neglects time-dependent phenomena and plasma flows, the force-free approach neglects additionally the gradient of the plasma pressure and the gravity force. This leads to the assumption of a vanishing Lorentz force and electric currents are parallel (or anti-parallel) to the magnetic field lines. Finally, the potential field approach neglects also these currents. We outline the main assumptions, benefits and limitations of these models both from a theoretical (how realistic are the models?) and a practical viewpoint (which computer resources to we need?). Finally we address the important problem of noisy and inconsistent photospheric boundary conditions and the possibility of using chromospheric and coronal observations to improve the models.

  18. Kinetic description of intense nonneutral beam propagation through a periodic solenoidal focusing field based on the nonlinear Vlasov-Maxwell equations

    SciTech Connect

    Davidson, R.C.; Chen, C.

    1997-08-01

    A kinetic description of intense nonneutral beam propagation through a periodic solenoidal focusing field B{sup sol}({rvec x}) is developed. The analysis is carried out for a thin beam with characteristic beam radius r{sub b} {much_lt} S, and directed axial momentum {gamma}{sub b}m{beta}{sub b}c (in the z-direction) large compared with the transverse momentum and axial momentum spread of the beam particles. Making use of the nonlinear Vlasov-Maxwell equations for general distribution function f{sub b}({rvec x},{rvec p},t) and self-consistent electrostatic field consistent with the thin-beam approximation, the kinetic model is used to investigate detailed beam equilibrium properties for a variety of distribution functions. Examples are presented both for the case of a uniform solenoidal focusing field B{sub z}(z) = B{sub 0} = const. and for the case of a periodic solenoidal focusing field B{sub z}(z + S) = B{sub z}(z). The nonlinear Vlasov-Maxwell equations are simplified in the thin-beam approximation, and an alternative Hamiltonian formulation is developed that is particularly well-suited to intense beam propagation in periodic focusing systems. Based on the present analysis, the Vlasov-Maxwell description of intense nonneutral beam propagation through a periodic solenoidal focusing field {rvec B}{sup sol}({rvec x}) is found to be remarkably tractable and rich in physics content. The Vlasov-Maxwell formalism developed here can be extended in a straightforward manner to investigate detailed stability behavior for perturbations about specific choices of beam equilibria.

  19. Magnetic Field Stabilization for 129Xe EDM Search Experiment

    NASA Astrophysics Data System (ADS)

    Furukawa, Takeshi; Inoue, Takeshi; Nanao, Tsubasa; Yoshimi, Akihiro; Tsuchiya, Masato; Hayashi, Hironori; Uchida, Makoto; Asahi, Koichiro

    2011-09-01

    Magnetic field stabilization is a crucial condition parameter for many kinds of ultra-high precision measurements such as a search for an electric dipole moment (EDM). The instability of magnetic field strength often arises from the drift of current flow in a solenoid coil to generate the magnetic field. For our EDM search experiment with maser oscillating diamagnetic 129Xe atoms, we have developed a new stabilized current source based on a feedback system which is devised to correct the amount of current flow measured precisely with high-precision digital multimeter and standard resistor. Using this new current source, we have successfully reduced the drifts of coil current by at least a factor of 100 compared to commercially available current sources.

  20. Dense Metal Plasma in a Solenoid for Ion Beam Neutralization

    SciTech Connect

    Anders, Andre; Kauffeldt, Marina; Oks, Efim M.; Roy, Prabir K.

    2010-10-30

    Space-charge neutralization is required to compress and focus a pulsed, high-current ion beam on a target for warm dense matter physics or heavy ion fusion experiments. We described approaches to produce dense plasma in and near the final focusing solenoid through which the ion beam travels, thereby providing an opportunity for the beam to acquire the necessary space-charge compensating electrons. Among the options are plasma injection from pulsed vacuum arc sources located outside the solenoid, and using a high current (> 4 kA) pulsed vacuum arc plasma from a ring cathode near the edge of the solenoid. The plasma distribution is characterized by photographic means, by an array of movable Langmuir probes, by a small single probe, and by evaluating Stark broadening of the Balmer H beta spectral line. In the main approach described here, the plasma is produced at several cathode spots distributed azimuthally on the ring cathode. It is shown that the plasma is essentially hollow, as determined by the structure of the magnetic field, though the plasma density exceeds 1014 cm-3 in practically all zones of the solenoid volume if the ring electrode is placed a few centimeters off the center of the solenoid. The plasma is non-uniform and fluctuating, however, since its density exceeds the ion beam density it is believed that this approach could provide a practical solution to the space charge neutralization challenge.

  1. Superhorizon magnetic fields

    NASA Astrophysics Data System (ADS)

    Campanelli, Leonardo

    2016-03-01

    We analyze the evolution of superhorizon-scale magnetic fields from the end of inflation till today. Whatever is the mechanism responsible for their generation during inflation, we find that a given magnetic mode with wave number k evolves, after inflation, according to the values of k ηe , nk , and Ωk , where ηe is the conformal time at the end of inflation, nk is the number density spectrum of inflation-produced photons, and Ωk is the phase difference between the two Bogoliubov coefficients which characterize the state of that mode at the end of inflation. For any realistic inflationary magnetogenesis scenario, we find that nk-1≪|k ηe|≪1 , and three evolutionary scenarios are possible: (i) |Ωk∓π |=O (1 ) , in which case the evolution of the magnetic spectrum Bk(η ) is adiabatic, a2Bk(η )=const , with a being the expansion parameter; (ii) |Ωk∓π |≪|k ηe| , in which case the evolution is superadiabatic, a2Bk(η )∝η ; (iii) |k ηe|≪|Ωk∓π |≪1 or |k ηe|˜|Ωk∓π |≪1 , in which case an early phase of adiabatic evolution is followed, after a time η⋆˜|Ωk∓π |/k , by a superadiabatic evolution. Once a given mode reenters the horizon, it remains frozen into the plasma and then evolves adiabatically till today. As a corollary of our results, we find that inflation-generated magnetic fields evolve adiabatically on all scales and for all times in conformal-invariant free Maxwell theory, while they evolve superadiabatically after inflation on superhorizon scales in the nonconformal-invariant Ratra model, where the inflaton is kinematically coupled to the electromagnetic field. The latter result supports and, somehow, clarifies our recent claim that the Ratra model can account for the presence of cosmic magnetic fields without suffering from both backreaction and strong-coupling problems.

  2. Magnetic Field Topology in Jets

    NASA Technical Reports Server (NTRS)

    Gardiner, T. A.; Frank, A.

    2000-01-01

    We present results on the magnetic field topology in a pulsed radiative. jet. For initially helical magnetic fields and periodic velocity variations, we find that the magnetic field alternates along the, length of the jet from toroidally dominated in the knots to possibly poloidally dominated in the intervening regions.

  3. Low field magnetic resonance imaging

    DOEpatents

    Pines, Alexander; Sakellariou, Dimitrios; Meriles, Carlos A.; Trabesinger, Andreas H.

    2010-07-13

    A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

  4. Electric and magnetic fields

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.; Robinson, R. S.; Etters, R. D.

    1982-01-01

    A number of energy momentum anomalies are described that result from the use of Abraham-Lorentz electromagnetic theory. These anomalies have in common the motion of charged bodies or current carrying conductors relative to the observer. The anomalies can be avoided by using the nonflow approach, based on internal energy of the electromagnetic field. The anomalies can also be avoided by using the flow approach, if all contributions to flow work are included. The general objective of this research is a fundamental physical understanding of electric and magnetic fields which, in turn, might promote the development of new concepts in electric space propulsion. The approach taken is to investigate quantum representations of these fields.

  5. Thermal design of the Mu2e detector solenoid

    SciTech Connect

    Dhanaraj, N.; Wands, R.; Buehler, M.; Feher, S.; Page, T.; Peterson, T.; Schmitt, R.

    2014-12-18

    The reference design for a superconducting detector solenoid (DS) for the Mu2e experiment has been completed. In this study, the main functions of the DS are to provide a graded field in the region of the stopping target, which ranges from 2 to 1 T and a uniform precision magnetic field of 1 T in a volume large enough to house a tracker downstream of the stopping target. The inner diameter of the magnet cryostat is 1.9 m and the length is 10.9 m. The gradient section of the magnet is about 4 m long and the spectrometer section with a uniform magnetic field is about 6 m long. The inner cryostat wall supports the stopping target, tracker, calorimeter and other equipment installed in the DS. This warm bore volume is under vacuum during operation. It is sealed on one end by the muon beam stop, while it is open on the other end where it interfaces with the Transport Solenoid. The operating temperature of the magnetic coil is 4.7 K and is indirectly cooled with helium flowing in a thermosiphon cooling scheme. This paper describes the thermal design of the solenoid, including the design aspects of the thermosiphon for the coil cooling, forced flow cooling of the thermal shields with 2 phase LN2 (Liquid Nitrogen) and the transient studies of the cool down of the cold mass as well.

  6. Thermal design of the Mu2e detector solenoid

    DOE PAGESBeta

    Dhanaraj, N.; Wands, R.; Buehler, M.; Feher, S.; Page, T.; Peterson, T.; Schmitt, R.

    2014-12-18

    The reference design for a superconducting detector solenoid (DS) for the Mu2e experiment has been completed. In this study, the main functions of the DS are to provide a graded field in the region of the stopping target, which ranges from 2 to 1 T and a uniform precision magnetic field of 1 T in a volume large enough to house a tracker downstream of the stopping target. The inner diameter of the magnet cryostat is 1.9 m and the length is 10.9 m. The gradient section of the magnet is about 4 m long and the spectrometer section withmore » a uniform magnetic field is about 6 m long. The inner cryostat wall supports the stopping target, tracker, calorimeter and other equipment installed in the DS. This warm bore volume is under vacuum during operation. It is sealed on one end by the muon beam stop, while it is open on the other end where it interfaces with the Transport Solenoid. The operating temperature of the magnetic coil is 4.7 K and is indirectly cooled with helium flowing in a thermosiphon cooling scheme. This paper describes the thermal design of the solenoid, including the design aspects of the thermosiphon for the coil cooling, forced flow cooling of the thermal shields with 2 phase LN2 (Liquid Nitrogen) and the transient studies of the cool down of the cold mass as well.« less

  7. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory.

    PubMed

    Ikeda, S; Kumaki, M; Kanesue, T; Okamura, M

    2016-02-01

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL. PMID:26931976

  8. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory

    NASA Astrophysics Data System (ADS)

    Ikeda, S.; Kumaki, M.; Kanesue, T.; Okamura, M.

    2016-02-01

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  9. Quench anaylsis of MICE spectrometer superconducting solenoid

    SciTech Connect

    Kashikhin, Vladimir; Bross, Alan; Prestemon, Soren; / /LBL, Berkeley

    2011-09-01

    MICE superconducting spectrometer solenoids fabrication and tests are in progress now. First tests of the Spectrometer Solenoid discovered some issues which could be related to the chosen passive quench protection system. Both solenoids do not have heaters and quench propagation relied on the 'quench back' effect, cold diodes, and shunt resistors. The solenoids have very large inductances and stored energy which is 100% dissipated in the cold mass during a quench. This makes their protection a challenging task. The paper presents the quench analysis of these solenoids based on 3D FEA solution of coupled transient electromagnetic and thermal problems. The simulations used the Vector Fields QUENCH code. It is shown that in some quench scenarios, the quench propagation is relatively slow and some areas can be overheated. They describe ways of improving the solenoids quench protection in order to reduce the risk of possible failure.

  10. Absolute magnetic helicity and the cylindrical magnetic field

    NASA Astrophysics Data System (ADS)

    Low, B. C.

    2011-05-01

    evolution; (iii) twist as a topological property of solenoidal fields versus the linkage properties of open and closed discrete curves treated by Gauss, Caligarneau, Berger, and Prior; and (iv) the change of absolute helicity by resistive diffusion. These are important hydromagnetic properties of twisted magnetic fields in the million-degree hot, highly conducting corona of the Sun.

  11. Reconnection of Magnetic Fields

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Spacecraft observations of steady and nonsteady reconnection at the magnetopause are reviewed. Computer simulations of three-dimensional reconnection in the geomagnetic tail are discussed. Theoretical aspects of the energization of particles in current sheets and of the microprocesses in the diffusion region are presented. Terrella experiments in which magnetospheric reconnection is simulated at both the magnetopause and in the tail are described. The possible role of reconnection in the evolution of solar magnetic fields and solar flares is discussed. A two-dimensional magnetohydrodynamic computer simulation of turbulent reconnection is examined. Results concerning reconnection in Tokamak devices are also presented.

  12. Magnetic fields and stardust

    NASA Technical Reports Server (NTRS)

    Hildebrand, Roger H.

    1988-01-01

    The purpose of this paper is to outline the principles governing the use of far-infrared and submillimeter polarimetry to investigate magnetic fields and dust in interstellar clouds. Particular topics of discussion are the alignment of dust grains in dense clouds, the dependence on wavelength of polarization due to emission or to partial absorption by aligned grains, the nature of that dependence for mixtures of grains with different properties, and the problem of distinguishing between (1) the effects of the shapes and dielectric functions of the grains and (2) the degree and direction of their alignment.

  13. Simulations of Dynamical Friction Including Spatially-Varying Magnetic Fields

    SciTech Connect

    Bell, G. I.; Bruhwiler, D. L.; Busby, R.; Abell, D. T.; Messmer, P.; Veitzer, S.; Litvinenko, V. N.; Cary, J. R.

    2006-03-20

    A proposed luminosity upgrade to the Relativistic Heavy Ion Collider (RHIC) includes a novel electron cooling section, which would use {approx}55 MeV electrons to cool fully-ionized 100 GeV/nucleon gold ions. We consider the dynamical friction force exerted on individual ions due to a relevant electron distribution. The electrons may be focussed by a strong solenoid field, with sensitive dependence on errors, or by a wiggler field. In the rest frame of the relativistic co-propagating electron and ion beams, where the friction force can be simulated for nonrelativistic motion and electrostatic fields, the Lorentz transform of these spatially-varying magnetic fields includes strong, rapidly-varying electric fields. Previous friction force simulations for unmagnetized electrons or error-free solenoids used a 4th-order Hermite algorithm, which is not well-suited for the inclusion of strong, rapidly-varying external fields. We present here a new algorithm for friction force simulations, using an exact two-body collision model to accurately resolve close interactions between electron/ion pairs. This field-free binary-collision model is combined with a modified Boris push, using an operator-splitting approach, to include the effects of external fields. The algorithm has been implemented in the VORPAL code and successfully benchmarked.

  14. AC Loss Analysis on the Superconducting Coupling Magnet in MICE

    SciTech Connect

    Wu, Hong; Wang, Li; Green, Michael; Li, LanKai; Xu, FengYu; Liu, XiaoKun; Jia, LinXinag

    2008-07-08

    A pair of coupling solenoids is used in MICE experiment to generate magnetic field which keeps the muons within the iris of thin RF cavity windows. The coupling solenoids have a 1.5-meter inner diameter and will produce 7.4 T peak magnetic field. Three types of AC losses in coupling solenoid are discussed. The affect of AC losses on the temperature distribution within the cold mass during charging and rapid discharging process is analyzed also. The analysis result will be further confirmed by the experiment of the prototype solenoid for coupling solenoid, which will be designed, fabricated and tested at ICST.

  15. Photonic Magnetic Field Sensor

    NASA Astrophysics Data System (ADS)

    Wyntjes, Geert

    2002-02-01

    Small, in-line polarization rotators or isolators to reduce feedback in fiber optic links can be the basis for excellent magnetic field sensors. Based on the giant magneto-optical (GMO) or Faraday effect in iron garnets, they with a magnetic field of a few hundred Gauss, (20 mT) for an interaction length for an optical beam of a few millimeters achieve a polarization rotation or phase shift of 45 deg (1/8 cycle). When powered by a small laser diode, with the induced linear phase shift recovered at the shot noise limit, we have demonstrated sensitivities at the 3.3 nT/Hz1/2 level for frequencies from less than 1 Hz to frequencies into the high kHz range. Through further improvements; an increase in interaction length, better materials and by far the greatest factor, the addition of a flux concentrator, sensitivities at the pT/Hz1/2 level appear to be within reach. We will detail such a design and discuss the issues that may limit achieving these goals.

  16. Polar Magnetic Field Experiment

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1999-01-01

    This grant covers the initial data reduction and analysis of the magnetic field measurements of the Polar spacecraft. At this writing data for the first three years of the mission have been processed and deposited in the key parameter database. These data are also available in a variety of time resolutions and coordinate systems via a webserver at UCLA that provides both plots and digital data. The flight software has twice been reprogrammed: once to remove a glitch in the data where there were rare collisions between commands in the central processing unit and once to provide burst mode data at 100 samples per second on a regular basis. The instrument continues to function as described in the instrument paper (1.1 in the bibliography attached below). The early observations were compared with observations on the same field lines at lower altitude. The polar magnetic measurements also proved to be most useful for testing the accuracy of MHD models. WE also made important contributions to study of waves and turbulence.

  17. Magnetized boxes for housing polarized spins in homogeneous fields.

    PubMed

    Hiebel, S; Grossmann, T; Kiselev, D; Schmiedeskamp, J; Gusev, Y; Heil, W; Karpuk, S; Krimmer, J; Otten, E W; Salhi, Z

    2010-05-01

    We present novel types of permanently magnetized as well as current powered boxes built from soft-ferromagnetic materials. They provide shielded magnetic fields which are homogeneous within a large fraction of the enclosed volume, thus minimizing size, weight, and costs. For the permanently magnetized solutions, homogenization is achieved either by an optimized distribution of the permanent field sources or by jacketing the field with a soft-ferromagnetic cylindrical shell which is magnetized in parallel to the enclosed field. The latter principle may be applied up to fields of about 0.1T. With fields of about 1mT, such boxes are being used for shipping spin-polarized (3)He worldwide for MRI purposes. For current powered boxes, we present concepts and realizations of uniaxial and tri-axial shielded magnetic fields which are homogeneous on the level of 10(-4) within the entire shielded volume. This is achieved by inserting tightly fitting solenoids into a box from soft-magnetic material. The flexible tri-axial solution suits in particular laboratory applications, e.g. for establishing a spin quantization axis. PMID:20211572

  18. An ultra-thin-walled solenoid for the CELSIUS/WASA experiments

    NASA Astrophysics Data System (ADS)

    Ruber, R. J. M. Y.; Blom, M.; Calén, H.; Fridén, C.-J.; Larsson, A.; Norman, G.; Yamamoto, A.; Yamaoka, H.; Makida, Y.; Kimura, N.; Tanaka, K.; Iida, M.; Ohhata, H.; Hirabayashi, H.; Takasu, N.; Nawrot, A.

    2003-05-01

    An ultra-thin-walled superconducting warm bore solenoid has been developed for the WASA detector set-up at the CELSIUS accelerator of the The Svedberg Laboratory (TSL), Sweden. It gives a central magnetic field up to 1.3 T, and can be operated in persistent mode. The total thickness of the superconducting coil is 9 mm with an inner diameter of 554 mm and an energy-to-cold-mass ratio of 6 kJ/ kg. The total wall thickness is a record low 0.18 in units of the radiation length ( X0) including the material of the cryostat. The solenoid has been successfully operated in combination with the WASA detector set-up since 1998. The solenoid has a coil split in two parts with a central gap of 40 mm for a tube guiding small frozen hydrogen target pellets into the accelerator beam. The solenoid is fixed by glass-fibre supports. It has a vacuum vessel with 1 mm thick corrugated walls of aluminium and it has high-purity aluminium strips in axial direction to improve heat conduction. The solenoid is enclosed by an iron yoke which shields the detector readout electronics from the magnetic field. A diagnostics, control and safety system has been developed for the solenoid itself and for the associated cryogenics.

  19. Magnetic Fields: Visible and Permanent.

    ERIC Educational Resources Information Center

    Winkeljohn, Dorothy R.; Earl, Robert D.

    1983-01-01

    Children will be able to see the concept of a magnetic field translated into a visible reality using the simple method outlined. Standard shelf paper, magnets, iron filings, and paint in a spray can are used to prepare a permanent and well-detailed picture of the magnetic field. (Author/JN)

  20. Note: High temperature pulsed solenoid valve.

    PubMed

    Shen, Wei; Sulkes, Mark

    2010-01-01

    We have developed a high temperature pulsed solenoid valve with reliable long term operation to at least 400 degrees C. As in earlier published designs, a needle extension sealing a heated orifice is lifted via solenoid actuation; the solenoid is thermally isolated from the heated orifice region. In this new implementation, superior sealing and reliability were attained by choosing a solenoid that produces considerably larger lifting forces on the magnetically actuated plunger. It is this property that facilitates easily attainable sealing and reliability, albeit with some tradeoff in attainable gas pulse durations. The cost of the solenoid valve employed is quite low and the necessary machining quite simple. Our ultimate level of sealing was attained by making a simple modification to the polished seal at the needle tip. The same sealing tip modification could easily be applied to one of the earlier high T valve designs, which could improve the attainability and tightness of sealing for these implementations. PMID:20113132

  1. Investigation and simulation of muon cooling rings with tilted solenoids

    SciTech Connect

    Valeri I. Balbekov

    2003-05-28

    Alternating solenoid focused muon cooling ring without special bending magnets is considered and investigate in detail. Both fringe field between solenoid coils with opposite directed current, and an inclination of the coils in vertical plane are used to provide a bending and closing of the particle trajectories. Realistic (Maxwellian) magnetic field is calculated and used for a simulation. Methodic is developed and applied to find closed orbit at any energy, dispersion, region of stability, and other conventional accelerator characteristics. Earlier proposed RFOFO cooling ring with 200 MHz RF system and liquid hydrogen absorbers is investigated in detail. After an optimization, normalized 6D emittance about 20 mm{sup 3} and transmission 57% are obtained.

  2. Observations of galactic magnetic fields

    NASA Astrophysics Data System (ADS)

    Beck, Rainer

    Magnetic fields are enchored in gas clouds. Field lines are tangled in spiral arms, but highly regular between the arms. The similarity of pitch angles between gaseous and magnetic arms suggests a coupling between the density wave and the magnetic wave. Observations of large-scale patterns in Faraday rotation favour a dynamo origin of the regular fields. Fields in barred galaxies do not reveal the strong shearing shocks observed in the cold gas, but swing smoothly from the upstream region into the bar. Magnetic fields are important for the dynamcis of gas clouds, for the formation of spiral structures, bars and halos, and for mass and angular momentum transport in central regions.

  3. Fast superconducting magnetic field switch

    DOEpatents

    Goren, Y.; Mahale, N.K.

    1996-08-06

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles. 6 figs.

  4. Fast superconducting magnetic field switch

    DOEpatents

    Goren, Yehuda; Mahale, Narayan K.

    1996-01-01

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles.

  5. Martian external magnetic field proxies

    NASA Astrophysics Data System (ADS)

    Langlais, Benoit; Civet, Francois

    2015-04-01

    Mars possesses no dynamic magnetic field of internal origin as it is the case for the Earth or for Mercury. Instead Mars is characterized by an intense and localized magnetic field of crustal origin. This field is the result of past magnetization and demagnetization processes, and reflects its evolution. The Interplanetary Magnetic Field (IMF) interacts with Mars' ionized environment to create an external magnetic field. This external field is weak compared to lithospheric one but very dynamic, and may hamper the detailed analysis of the internal magnetic field at some places or times. Because there are currently no magnetic field measurements made at Mars' surface, it is not possible to directly monitor the external field temporal variability as it is done in Earth's ground magnetic observatories. In this study we examine to indirect ways of quantifying this external field. First we use the Advanced Composition Explorer (ACE) mission which measures the solar wind about one hour upstream of the bow-shock resulting from the interaction between the solar wind and the Earth's internal magnetic field. These measurements are extrapolated to Mars' position taking into account the orbital configurations of the Mars-Earth system and the velocity of particles carrying the IMF. Second we directly use Mars Global Surveyor magnetic field measurements to quantify the level of variability of the external field. We subtract from the measurements the internal field which is otherwise modeled, and bin the residuals first on a spatial and then on a temporal mesh. This allows to compute daily or semi daily index. We present a comparison of these two proxies and demonstrate their complementarity. We also illustrate our analysis by comparing our Martian external field proxies to terrestrial index at epochs of known strong activity. These proxies will especially be useful for upcoming magnetic field measurements made around or at the surface of Mars.

  6. Cyclical magnetic field flow fractionation

    NASA Astrophysics Data System (ADS)

    Tasci, T. O.; Johnson, W. P.; Gale, B. K.

    2012-04-01

    In this study, a new magnetic field flow fractionation (FFF) system was designed and modeled by using finite element simulations. Other than current magnetic FFF systems, which use static magnetic fields, our system uses cyclical magnetic fields. Results of the simulations show that our cyclical magnetic FFF system can be used effectively for the separation of magnetic nanoparticles. Cyclical magnetic FFF system is composed of a microfluidic channel (length = 5 cm, height = 30 μm) and 2 coils. Square wave currents of 1 Hz (with 90 deg of phase difference) were applied to the coils. By using Comsol Multiphysics 3.5a, magnetic field profile and corresponding magnetic force exerted on the magnetite nanoparticles were calculated. The magnetic force data were exported from Comsol to Matlab. In Matlab, a parabolic flow profile with maximum flow speed of 0.4 mL/h was defined. Particle trajectories were obtained by the calculation of the particle speeds resulted from both magnetic and hydrodynamic forces. Particle trajectories of the particles with sizes ranging from 10 to 50 nm were simulated and elution times of the particles were calculated. Results show that there is a significant difference between the elution times of the particles so that baseline separation of the particles can be obtained. In this work, it is shown that by the application of cyclical magnetic fields, the separation of magnetic nanoparticles can be done efficiently.

  7. Magnetic field modification of optical magnetic dipoles.

    PubMed

    Armelles, Gaspar; Caballero, Blanca; Cebollada, Alfonso; Garcia-Martin, Antonio; Meneses-Rodríguez, David

    2015-03-11

    Acting on optical magnetic dipoles opens novel routes to govern light-matter interaction. We demonstrate magnetic field modification of the magnetic dipolar moment characteristic of resonant nanoholes in thin magnetoplasmonic films. This is experimentally shown through the demonstration of the magneto-optical analogue of Babinet's principle, where mirror imaged MO spectral dependencies are obtained for two complementary magnetoplasmonic systems: holes in a perforated metallic layer and a layer of disks on a substrate. PMID:25646869

  8. Exposure guidelines for magnetic fields.

    PubMed

    Miller, G

    1987-12-01

    The powerful magnetic fields produced by a controlled fusion experiment at Lawrence Livermore National Laboratory (LLNL) necessitated the development of personnel-exposure guidelines for steady magnetic fields. A literature search and conversations with active researchers showed that it is currently possible to develop preliminary exposure guidelines for steady magnetic fields. An overview of the results of past research into the bioeffects of magnetic fields was compiled, along with a discussion of hazards that may be encountered by people with sickle-cell anemia or medical electronic and prosthetic implants. The LLNL steady magnetic-field exposure guidelines along with a review of developments concerning the safety of time-varying fields were also presented in this compilation. Guidelines developed elsewhere for time varying fields were also given. Further research is needed to develop exposure standards for both steady or time-varying fields. PMID:3434538

  9. Exposure guidelines for magnetic fields

    SciTech Connect

    Miller, G.

    1987-12-01

    The powerful magnetic fields produced by a controlled fusion experiment at Lawrence Livermore National Laboratory (LLNL) necessitated the development of personnel-exposure guidelines for steady magnetic fields. A literature search and conversations with active researchers showed that it is currently possible to develop preliminary exposure guidelines for steady magnetic fields. An overview of the results of past research into the bioeffects of magnetic fields was compiled, along with a discussion of hazards that may be encountered by people with sickle-cell anemia or medical electronic and prosthetic implants. The LLNL steady magnetic-field exposure guidelines along with a review of developments concerning the safety of time-varying fields were also presented in this compilation. Guidelines developed elsewhere for time varying fields were also given. Further research is needed to develop exposure standards for both steady or time-varying fields.

  10. [Magnetic fields and fish behavior].

    PubMed

    Krylov, V V; Iziumov, Iu G; Izvekov, E I; Nepomniashchikh, V A

    2013-01-01

    In the review, contemporary data on the influence of natural and artificial magnetic fields on fish behavior are considered. In this regard, elasmobranchs and teleosts appear to be studied most exhaustively. Elasmobranchs and some teleosts are able to perceive magnetic fields via electroreceptors. A number of teleosts can sense magnetic fields via sensory cells containing crystals of biogenic magnetite. Laboratory experiments and field observations indicate the influence of magnetic fields on fish locomotor activity and spatial distribution. The geomagnetic field can be used by fish for navigation. Besides, artificial magnetic fields and natural fluctuations of the geomagnetic field can affect fish embryos leading to alterations in their development. It is suggested that, afterwards, these alterations can have an effect on fish behavior. PMID:25438567

  11. [Magnetic fields and fish behavior].

    PubMed

    2013-01-01

    In the review, contemporary data on the influence of natural and artificial magnetic fields on fish behavior are considered. In this regard, elasmobranchs and teleosts appear to be studied most exhaustively. Elasmobranchs and some teleosts are able to perceive magnetic fields via electroreceptors. A number of teleosts can sense magnetic fields via sensory cells containing crystals of biogenic magnetite. Laboratory experiments and field observations indicate the influence of magnetic fields on fish locomotor activity and spatial distribution. The geomagnetic field can be used by fish for navigation. Besides, artificial magnetic fields and natural fluctuations of the geomagnetic field can affect fish embryos leading to alterations in their development. It is suggested that, afterwards, these alterations can have an effect on fish behavior. PMID:25508098

  12. Design of the 2 Tesla superconducting solenoid for the Fermilab D0 detector upgrade

    SciTech Connect

    Squires, B.; Brzezniak, J.; Fast, R.W.; Krempetz, K.; Kristalinski, A.; Lee, A.; Markley, D.; Mesin, A.; Orr, S.; Rucinski, R.

    1994-12-31

    A thin superconducting solenoid has been designed for an upgrade to the Fermilab D0 detector, one of two major hadron collider detectors at Fermilab. The original design of the D0 detector did not incorporate a central magnetic field which necessitates a retrofit within the parameters of the existing tracking volume of the detector. The two layer solenoid coil is indirectly cooled and provides a 2 T magnetic field for a central tracking system. To minimize end effects in this no iron configuration, the conductor width is varied thereby increasing current density at the ends and improving field uniformity. This paper summarizes the results of the conceptual design study for the D0 superconducting solenoid.

  13. Magnetic-field-dosimetry system

    DOEpatents

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1981-01-21

    A device is provided for measuring the magnetic field dose and peak field exposure. The device includes three Hall-effect sensors all perpendicular to each other, sensing the three dimensional magnetic field and associated electronics for data storage, calculating, retrieving and display.

  14. Analytical Study of Stress State in HTS Solenoids

    SciTech Connect

    Barzi, E.; Terzini, E.; /Fermilab

    2009-01-01

    A main challenge for high field solenoids made of in High Temperature Superconductor (HTS) is the large stress developed in the conductor. This is especially constraining for BSCCO, a brittle and strain sensitive ceramic material. To find parametric correlations useful in magnet design, analytical models can be used. A simple model is herein proposed to obtain the radial, azimuthal and axial stresses in a solenoid as a function of size, i.e. self-field, and of the engineering current density for a number of different constraint hypotheses. The analytical model was verified against finite element modeling (FEM) using the same hypotheses of infinite rigidity of the constraints and room temperature properties. FEM was used to separately evaluate the effect of thermal contractions at 4.2 K for BSCCO and YBCO coils. Even though the analytical model allows for a finite stiffness of the constraints, it was run using infinite stiffness. For this reason, FEM was again used to determine how much stresses change when considering an outer stainless steel skin with finite rigidity for both BSCCO and YBCO coils. For a better understanding of the actual loads that high field solenoids made of HTS will be subject to, we have started some analytical studies of stress state in solenoids for a number of constraint hypotheses. This will hopefully show what can be achieved with the present conductor in terms of self-field. The magnetic field (B) exerts a force F = B x J per unit volume. In superconducting magnets, where the field and current density (J) are both high, this force can be very large, and it is therefore important to calculate the stresses in the coil.

  15. Report of the large solenoid detector group

    SciTech Connect

    Hanson, G.G.; Mori, S.; Pondrom, L.G.; Williams, H.H.; Barnett, B.; Barnes, V.; Cashmore, R.; Chiba, M.; DeSalvo, R.; Devlin, T.

    1987-09-01

    This report presents a conceptual design of a large solenoid for studying physics at the SSC. The parameters and nature of the detector have been chosen based on present estimates of what is required to allow the study of heavy quarks, supersymmetry, heavy Higgs particles, WW scattering at large invariant masses, new W and Z bosons, and very large momentum transfer parton-parton scattering. Simply stated, the goal is to obtain optimum detection and identification of electrons, muons, neutrinos, jets, W's and Z's over a large rapidity region. The primary region of interest extends over +-3 units of rapidity, although the calorimetry must extend to +-5.5 units if optimal missing energy resolution is to be obtained. A magnetic field was incorporated because of the importance of identifying the signs of the charges for both electrons and muons and because of the added possibility of identifying tau leptons and secondary vertices. In addition, the existence of a magnetic field may prove useful for studying new physics processes about which we currently have no knowledge. Since hermeticity of the calorimetry is extremely important, the entire central and endcap calorimeters were located inside the solenoid. This does not at the moment seem to produce significant problems (although many issues remain to be resolved) and in fact leads to a very effective muon detector in the central region.

  16. The Results of Tests of the MICE Spectrometer Solenoids

    SciTech Connect

    Green, Michael A.; Virostek, Steve P.

    2009-10-19

    The Muon Ionization Cooling Experiment (MICE) spectrometer solenoid magnets will be the first magnets to be installed within the MICE cooling channel. The spectrometer magnets are the largest magnets in both mass and surface area within the MICE ooling channel. Like all of the other magnets in MICE, the spectrometer solenoids are kept cold using 1.5 W (at 4.2 K) pulse tube coolers. The MICE spectrometer solenoid is quite possibly the largest magnet that has been cooled using small coolers. Two pectrometer magnets have been built and tested. This report discusses the results of current and cooler tests of both magnets.

  17. Magnetic fields in nearby spirals

    NASA Astrophysics Data System (ADS)

    Sun, Xiaohui; Lenc, Emil

    2013-10-01

    Magnetic fields play an important role in star formation process and dynamic evolution of galaxies. Previous studies of magnetic fields relied on narrow band polarisation observations and difficult to disentangle magnetised structures along line of sight. Thanks to the broad bandwidth and multi-channels of CABB we are now able to recover the 3D structures of magnetic fields using RM synthesis and QU-fitting. We propose to observe two nearby spirals M83 and NGC 4945 to build clear pictures of their magnetic fields.

  18. EU contribution to the test and analysis of the ITER poloidal field conductor insert and the central solenoid model coil

    NASA Astrophysics Data System (ADS)

    Zanino, R.; Bagnasco, M.; Ciazynski, D.; Lacroix, B.; van Lanen, E. P. A.; Nicollet, S.; Nijhuis, A.; Savoldi Richard, L.; Sborchia, C.; Torre, A.; Vostner, A.; Zani, L.

    2009-08-01

    The PFCI is a single-layer solenoid wound from a 45 m long ITER-type NbTi dual-channel cable-in-conduit conductor, designed to be representative of the one currently proposed for the ITER PF1&6 coils. The PFCI, installed in the bore of the ITER central solenoid model coil (CSMC) at JAEA Naka, Japan, and well instrumented from both the thermal hydraulic and the electromagnetic points of view, has been successfully tested in June-August 2008. The test concentrated on DC performance (current sharing temperature and critical current measurements) and AC loss measurements. The results of the analysis of those measurements are reported in the paper, with particular attention to the comparison with the PFCI short sample, which was previously tested in the SULTAN facility. The evolution of the DC performance of the CSMC is also discussed.

  19. The Wisconsin Pegasus solenoid

    NASA Astrophysics Data System (ADS)

    Pernambuco-Wise, P.; Lesch, B. L.; Schneider-Muntau, H. J.; Intrator, T. P.; Fonck, R. J.; Winz, G. R.

    1998-05-01

    A 1.6 m long x0.1m diameter coil has just been constructed by the NHMFL for the University of Wisconsin Pegasus Tokamak. It will form the central solenoid for the high plasma energy density fusion machine. The magnet consists of two layers of Glidcop conductor, reinforced with S2 glass, carbon fiber and steel. Normal operating parameters will be 14 T in a 58 mm bore with a number of pulses to 20 T+. Current densities will approach 1 kA/mm2 and the stored energy will be >2 MJ. The philosophy behind the design will be presented and details of the construction and testing will be shown.

  20. Muscle Motion Solenoid Actuator

    NASA Astrophysics Data System (ADS)

    Obata, Shuji

    It is one of our dreams to mechanically recover the lost body for damaged humans. Realistic humanoid robots composed of such machines require muscle motion actuators controlled by all pulling actions. Particularly, antagonistic pairs of bi-articular muscles are very important in animal's motions. A system of actuators is proposed using the electromagnetic force of the solenoids with the abilities of the stroke length over 10 cm and the strength about 20 N, which are needed to move the real human arm. The devised actuators are based on developments of recent modern electro-magnetic materials, where old time materials can not give such possibility. Composite actuators are controlled by a high ability computer and software making genuine motions.

  1. Bent solenoids for spectrometers and emittance exchange sections.

    SciTech Connect

    Norem, J.

    1999-03-26

    Bent solenoids can be used to transport low energy beams as they provide both confinement and dispersion of particle orbits. Solenoids are being considered both as emittance exchange sections and spectrometers in the muon cooling system as part of the study of the muon collider. They present the results of a study of bent solenoids which considers the design of coupling sections between bent solenoids to straight solenoids, drift compensation fields, aberrations, and factors relating to the construction, such as field ripple, stored energy, coil forces and field errors.

  2. A Computer Study of Beam Transport by Solenoids

    NASA Astrophysics Data System (ADS)

    Chan, Chun Fai; Lee, Edward P.

    1997-11-01

    Beam transport by solenoids provides an alternative to the use of electrostatic quadrupole arrays that has been less studied for applications to heavy ion fusion drivers. A 1-d code (named SALT, for Solenoid Applications to Linac Transport) has been developed to simulate the axisymmetric beam dynamics through a sequence of solenoids. The beam is modeled as a set of ringlets, with radius and momentum traced in the axial coordinate. Solenoid fringe field aberrations, envelope matching, phase space evolution and emittance growth are studied using relativistically correct equations that include the electric and magnetic fields of the beam. Initial application is to the transport of a 2 MeV, 31.10 Ampere of K^+ beam through a channel of strength 6 Tesla. This implies a line charge density of 10 μC/m, a factor of 40 above the realistic limit for electrostatic quadrupoles. A second application is to the focusing of a 20 MeV, 4 kA electron beam down to its emittance limit.

  3. Refrigerator and Solenoid Run Summary August/September 1999

    SciTech Connect

    Rucinski, R.; /Fermilab

    1999-09-20

    The helium refrigerator was cooled down and operated for the third time since its installation. D-Zero's 2 Tesla superconducting solenoid was cooled down and operated for its second time since its installation into the D-Zero detector. This engineering note summarizes the cryogenic aspects of the test run and performance measurements made. The main purpose of this run was to do field mapping of the solenoid with different combinations of field polarity on the Solenoid and CF iron magnets. This was accomplished. A second purpose was to test the lower field joint repair that was done in January 1999. This field joint had a measurable voltage drop across the soldered bus splice. The repair was an undoing of the joint, extensive cleaning of the bus, and then welding the splice. The repair was successful, no voltage drop was measured and the magnet behaved nicely. A parasitic purpose was to get some operating time on the refrigerator, measure the refrigeration performance, and measure the heat leak in the VLPC lines mounted on the detector platform. Refrigerator performance was spot checked, and was found to be 60 watts (10%) less than generic operating curves. At this level of performance, the operating margin for the full solenoid and VLPC system will be 75 watts (15%) which is somewhat uncomfortable from an operational stand point. The VLPC lines were operated and heat leak numbers of around 40 watts was measured for each pipe section including the supply u-tubes to the detector, the bayonet can, valve box on the platform and the piping back to the refrigerator valve box. Another purpose of the test run was to test the compatibility of other detector components with the new central magnetic field environment. I do not know the results of these tests.

  4. Vestibular stimulation by magnetic fields

    PubMed Central

    Ward, Bryan K.; Roberts, Dale C.; Della Santina, Charles C.; Carey, John P.; Zee, David S.

    2015-01-01

    Individuals working next to strong static magnetic fields occasionally report disorientation and vertigo. With the increasing strength of magnetic fields used for magnetic resonance imaging (MRI) studies, these reports have become more common. It was recently learned that humans, mice and zebrafish all demonstrate behaviors consistent with constant peripheral vestibular stimulation while inside a strong, static magnetic field. The proposed mechanism for this effect involves a Lorentz force resulting from the interaction of a strong static magnetic field with naturally occurring ionic currents flowing through the inner ear endolymph into vestibular hair cells. The resulting force within the endolymph is strong enough to displace the lateral semicircular canal cupula, inducing vertigo and the horizontal nystagmus seen in normal mice and in humans. This review explores the evidence for interactions of magnetic fields with the vestibular system. PMID:25735662

  5. Magnetic fields around evolved stars

    NASA Astrophysics Data System (ADS)

    Leal-Ferreira, M.; Vlemmings, W.; Kemball, A.; Amiri, N.; Maercker, M.; Ramstedt, S.; Olofsson, G.

    2014-04-01

    A number of mechanisms, such as magnetic fields, (binary) companions and circumstellar disks have been suggested to be the cause of non-spherical PNe and in particular collimated outflows. This work investigates one of these mechanisms: the magnetic fields. While MHD simulations show that the fields can indeed be important, few observations of magnetic fields have been done so far. We used the VLBA to observe five evolved stars, with the goal of detecting the magnetic field by means of water maser polarization. The sample consists in four AGB stars (IK Tau, RT Vir, IRC+60370 and AP Lyn) and one pPN (OH231.8+4.2). In four of the five sources, several strong maser features were detected allowing us to measure the linear and/or circular polarization. Based on the circular polarization detections, we infer the strength of the component of the field along the line of sight to be between ~30 mG and ~330 mG in the water maser regions of these four sources. When extrapolated to the surface of the stars, the magnetic field strength would be between a few hundred mG and a few Gauss when assuming a toroidal field geometry and higher when assuming more complex magnetic fields. We conclude that the magnetic energy we derived in the water maser regions is higher than the thermal and kinetic energy, leading to the conclusion that, indeed, magnetic fields probably play an important role in shaping Planetary Nebulae.

  6. A Comparison of the Availability and Failure Modes of the BaBar Superconducting Solenoid with Similar Magnets at Other High Energy Physics Laboratories

    SciTech Connect

    Knodel, Mallory

    2003-09-05

    One of the key technologies in the BaBar detector is the 1.5 T superconducting solenoid. It is imperative that this device operate reliably at its nominal current to allow data taking. While this system is available for physics 98.8% of the time, further improvements are desirable. The object of this project is to survey similar magnet systems, for example those at KEK (Belle), Fermilab (D0 and CDF), DESY (H1 and ZEUS), and CERN (ALEPH and DELPHI), to see how often such magnets stop functioning properly and what the root causes of the failures are. A survey was carried out via e-mail and telephone calls. Information was obtained regarding the operation of superconducting magnets, specifically the BaBar magnet and its ancillary systems, as well as an overview of the use of other such magnets both in the US and overseas. In this work, failure modes will be investigated and compared to the BaBar operational experience. Future investigations can now assess the feasibility of reducing the time the BaBar magnet is nonoperational and unavailable for physics research.

  7. Progress on the Fabrication and Testing of the MICE Spectrometer Solenoids

    SciTech Connect

    Virostek, Steve; Green, M.A.; Li, Derun; Zisman, Michael

    2009-05-19

    The Muon Ionization Cooling Experiment (MICE) is an international collaboration that will demonstrate ionization cooling in a section of a realistic cooling channel using a muon beam at Rutherford Appleton Laboratory (RAL) in the UK. At each end of the cooling channel a spectrometer solenoid magnet consisting of five superconducting coils will provide a 4 tesla uniform field region. The scintillating fiber tracker within the magnet bore will measure the muon beam emittance as it enters and exits the cooling channel. The 400 mm diameter warm bore, 3 meter long magnets incorporate a cold mass consisting of two coil sections wound on a single aluminum mandrel: a three-coil spectrometer magnet and a two-coil section that matches the solenoid uniform field into the MICE cooling channel. The fabrication of the first of two spectrometer solenoids has been completed, and preliminary testing of the magnet is nearly complete. The key design features of the spectrometer solenoid magnets are presented along with a summary of the progress on the training and testing of the first magnet.

  8. Thin film metallic sensors in an alternating magnetic field for magnetic nanoparticle hyperthermia cancer therapy

    NASA Astrophysics Data System (ADS)

    Hussein, Z. A.; Boekelheide, Z.

    In magnetic nanoparticle hyperthermia in an alternating magnetic field for cancer therapy, it is important to monitor the temperature in situ. This can be done optically or electrically, but electronic measurements can be problematic because conducting parts heat up in a changing magnetic field. Microfabricated thin film sensors may be advantageous because eddy current heating is a function of size, and are promising for further miniaturization of sensors and fabrication of arrays of sensors. Thin films could also be used for in situ magnetic field sensors or for strain sensors. For a proof of concept, we fabricated a metallic thin film resistive thermometer by photolithographically patterning a 500Å Au/100Å Cr thin film on a glass substrate. Measurements were taken in a solenoidal coil supplying 0.04 T (rms) at 235 kHz with the sensor parallel and perpendicular to the magnetic field. In the parallel orientation, the resistive thermometer mirrored the background heating from the coil, while in the perpendicular orientation self-heating was observed due to eddy current heating of the conducting elements by Faraday's law. This suggests that metallic thin film sensors can be used in an alternating magnetic field, parallel to the field, with no significant self-heating.

  9. Plasma shape control by pulsed solenoid on laser ion source

    DOE PAGESBeta

    Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

    2015-05-28

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. It was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled bymore » the pulsed magnetic field. Thus, this approach may also be useful to reduce beam emittance of a LIS.« less

  10. Plasma shape control by pulsed solenoid on laser ion source

    NASA Astrophysics Data System (ADS)

    Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

    2015-09-01

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  11. Plasma shape control by pulsed solenoid on laser ion source

    SciTech Connect

    Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

    2015-05-28

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. It was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. Thus, this approach may also be useful to reduce beam emittance of a LIS.

  12. Conceptual design of the Mu2e production solenoid cold mass

    SciTech Connect

    Kashikhin, V.V.; Ambrosio, G.; Andreev, N.; Lamm, M.; Mokhov, N.V.; Nicol, T.H.; Page, T.M.; Pronskikh, V.; /Fermilab

    2011-06-01

    The Muon-to-Electron conversion experiment (Mu2e), under development at Fermilab, seeks to detect direct muon to electron conversion to provide evidence for a process violating muon and electron lepton number conservation that cannot be explained by the Standard Model of particle physics. The required magnetic field is produced by a series of superconducting solenoids of various apertures and lengths. This paper describes the conceptual design of the 5 T, 4 m long solenoid cold mass with 1.67 m bore with the emphasis on the magnetic, radiation and thermal analyses.

  13. R&D ERL: HTS Solenoid

    SciTech Connect

    Gupta, R.; Muratore, J.; Plate, S.

    2010-01-01

    An innovative feature of the ERL project is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The HTS solenoid design offers many advantages because of several unique design features. Typically the solenoid is placed outside the cryostat which means that the beam gets significantly defused before a focusing element starts. In the current design, the solenoid is placed inside the cryostat which provides an early focusing structure and thus a significant reduction in the emittance of the electron beam. In addition, taking full advantage of the high critical temperature of HTS, the solenoid has been designed to reach the required field at {approx}77 K, which can be obtained with liquid nitrogen. This significantly reduces the cost of testing and allows a variety of critical pre-tests which would have been prohibitively expensive at 4 K in liquid helium because of the additional requirements of cryostat and associated facilities.

  14. The Capacitive Magnetic Field Sensor

    NASA Astrophysics Data System (ADS)

    Zyatkov, D. O.; Yurchenko, A. V.; Balashov, V. B.; Yurchenko, V. I.

    2016-01-01

    The results of a study of sensitive element magnetic field sensor are represented in this paper. The sensor is based on the change of the capacitance with an active dielectric (ferrofluid) due to the magnitude of magnetic field. To prepare the ferrofluid magnetic particles are used, which have a followingdispersion equal to 50 < Ø < 56, 45 < Ø < 50, 40 < Ø < 45 and Ø < 40micron of nanocrystalline alloy of brand 5BDSR. The dependence of the sensitivity of the capacitive element from the ferrofluid with different dispersion of magnetic particles is considered. The threshold of sensitivity and sensitivity of a measuring cell with ferrofluid by a magnetic field was determined. The experimental graphs of capacitance change of the magnitude of magnetic field are presented.

  15. Origin of cosmic magnetic fields.

    PubMed

    Campanelli, Leonardo

    2013-08-01

    We calculate, in the free Maxwell theory, the renormalized quantum vacuum expectation value of the two-point magnetic correlation function in de Sitter inflation. We find that quantum magnetic fluctuations remain constant during inflation instead of being washed out adiabatically, as usually assumed in the literature. The quantum-to-classical transition of super-Hubble magnetic modes during inflation allow us to treat the magnetic field classically after reheating, when it is coupled to the primeval plasma. The actual magnetic field is scale independent and has an intensity of few×10(-12)  G if the energy scale of inflation is few×10(16)  GeV. Such a field accounts for galactic and galaxy cluster magnetic fields. PMID:23971556

  16. Measurements of magnetic field alignment

    SciTech Connect

    Kuchnir, M.; Schmidt, E.E.

    1987-11-06

    The procedure for installing Superconducting Super Collider (SSC) dipoles in their respective cryostats involves aligning the average direction of their field with the vertical to an accuracy of 0.5 mrad. The equipment developed for carrying on these measurements is described and the measurements performed on the first few prototypes SSC magnets are presented. The field angle as a function of position in these 16.6 m long magnets is a characteristic of the individual magnet with possible feedback information to its manufacturing procedure. A comparison of this vertical alignment characteristic with a magnetic field intensity (by NMR) characteristic for one of the prototypes is also presented. 5 refs., 7 figs.

  17. Magnetic fields in young galaxies

    NASA Astrophysics Data System (ADS)

    Nordlund, Åke; Rögnvaldsson, Örnólfur

    We have studied the fate of initial magnetic fields in the hot halo gas out of which the visible parts of galaxies form, using three-dimensional numerical MHD-experiments. The halo gas undergoes compression by several orders of magnitude in the subsonic cooling flow that forms the cold disk. The magnetic field is carried along and is amplified considerably in the process, reaching μG levels for reasonable values of the initial ratio of magnetic to thermal energy density.

  18. The MAVEN Magnetic Field Investigation

    NASA Technical Reports Server (NTRS)

    Connerney, J. E. P.; Espley, J.; Lawton, P.; Murphy, S.; Odom, J.; Oliversen, R.; Sheppard, D.

    2014-01-01

    The MAVEN magnetic field investigation is part of a comprehensive particles and fields subsystem that will measure the magnetic and electric fields and plasma environment of Mars and its interaction with the solar wind. The magnetic field instrumentation consists of two independent tri-axial fluxgate magnetometer sensors, remotely mounted at the outer extremity of the two solar arrays on small extensions ("boomlets"). The sensors are controlled by independent and functionally identical electronics assemblies that are integrated within the particles and fields subsystem and draw their power from redundant power supplies within that system. Each magnetometer measures the ambient vector magnetic field over a wide dynamic range (to 65,536 nT per axis) with a quantization uncertainty of 0.008 nT in the most sensitive dynamic range and an accuracy of better than 0.05%. Both magnetometers sample the ambient magnetic field at an intrinsic sample rate of 32 vector samples per second. Telemetry is transferred from each magnetometer to the particles and fields package once per second and subsequently passed to the spacecraft after some reformatting. The magnetic field data volume may be reduced by averaging and decimation, when necessary to meet telemetry allocations, and application of data compression, utilizing a lossless 8-bit differencing scheme. The MAVEN magnetic field experiment may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors and the MAVEN mission plan provides for occasional spacecraft maneuvers - multiple rotations about the spacecraft x and z axes - to characterize spacecraft fields and/or instrument offsets in flight.

  19. The MAVEN Magnetic Field Investigation

    NASA Astrophysics Data System (ADS)

    Connerney, J. E. P.; Espley, J.; Lawton, P.; Murphy, S.; Odom, J.; Oliversen, R.; Sheppard, D.

    2015-12-01

    The MAVEN magnetic field investigation is part of a comprehensive particles and fields subsystem that will measure the magnetic and electric fields and plasma environment of Mars and its interaction with the solar wind. The magnetic field instrumentation consists of two independent tri-axial fluxgate magnetometer sensors, remotely mounted at the outer extremity of the two solar arrays on small extensions ("boomlets"). The sensors are controlled by independent and functionally identical electronics assemblies that are integrated within the particles and fields subsystem and draw their power from redundant power supplies within that system. Each magnetometer measures the ambient vector magnetic field over a wide dynamic range (to 65,536 nT per axis) with a resolution of 0.008 nT in the most sensitive dynamic range and an accuracy of better than 0.05 %. Both magnetometers sample the ambient magnetic field at an intrinsic sample rate of 32 vector samples per second. Telemetry is transferred from each magnetometer to the particles and fields package once per second and subsequently passed to the spacecraft after some reformatting. The magnetic field data volume may be reduced by averaging and decimation, when necessary to meet telemetry allocations, and application of data compression, utilizing a lossless 8-bit differencing scheme. The MAVEN magnetic field experiment may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors and the MAVEN mission plan provides for occasional spacecraft maneuvers—multiple rotations about the spacecraft x and z axes—to characterize spacecraft fields and/or instrument offsets in flight.

  20. Cosmic Magnetic Fields - An Overview

    NASA Astrophysics Data System (ADS)

    Wielebinski, Richard; Beck, Rainer

    Magnetic fields have been known in antiquity. Aristotle attributes the first of what could be called a scientific discussion on magnetism to Thales, who lived from about 625 BC. In China “magnetic carts” were in use to help the Emperor in his journeys of inspection. Plinius comments that in the Asia Minor province of Magnesia shepherds' staffs get at times “glued” to a stone, a alodestone. In Europe the magnetic compass came through the Arab sailors who met the Portuguese explorers. The first scientific treatise on magnetism, “De Magnete”, was published by William Gilbert who in 1600 described his experiments and suggested that the Earth was a huge magnet. Johannes Kepler was a correspondent of Gilbert and at times suggested that planetary motion was due to magnetic forces. Alas, this concept was demolished by Isaac Newton,who seeing the falling apple decided that gravity was enough. This concept of dealing with gravitational forces only remains en vogue even today. The explanations why magnetic effects must be neglected go from “magnetic energy is only 1% of gravitation” to “magnetic fields only complicate the beautiful computer solutions”. What is disregarded is the fact that magnetic effects are very directional(not omni-directional as gravity) and also the fact that magnetic fields are seen every where in our cosmic universe.

  1. Assessment of magnetic field asymmetries in ELMO Bumpy Square

    SciTech Connect

    Uckan, T.; Uckan, N.A.

    1985-01-01

    There exist two separate and independent magnetic field asymmetries in the ELMO Bumpy Square (EBS). One is associated with the small perturbations in the magnetic field, known as the field errors, caused by coil misalignments during installation, imperfection in coil winding, etc. The second source of asymmetry is the magnetic field ripple in the high-field toroidal solenoids (corners) produced by the finiteness of the number of coils. In general, these two sources of asymmetry introduce enhanced transport losses (in addition to other effects) to the system, although they affect different classes of particles. Toroidally passing (circulating) particles (v/sub parallel//v approx. 1) are influenced by the field errors, whereas trapped particles (v/sub parallel//v approx. 0) in the corners are influenced by the field ripple. In this paper we discuss these two effects separately and calculate the allowable magnitudes of the field error and field ripple in EBS, both for an experimental-size device and for a reactor.

  2. D0 Solenoid Commissioning September 1998

    SciTech Connect

    Rucinski, R.; /Fermilab

    1998-10-12

    D-Zero installed a new 2 Tesla superconducting solenoid magnet into the central tracking region of the D-Zero detector. This report documents the cryogenic performance of the superconducting solenoid during its first cryogenic operation at Fermilab. By necessity, the liquid helium refrigerator was also operated. This was the second time the refrigerator plant has been operated. The refrigerator's performance is also documented herein.

  3. Giant Magnetic Field-induced Phase Transitions in Dimeric Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Salili, Seyyed Muhammad; Salamonczyk, Miroslaw; Tamba, Maria-Gabriela; Sprunt, Samuel; Mehl, Georg; Jakli, Antal; Gleeson, James; Kent Group Collaboration; Hull Group Collaboration

    Liquid crystals are responsive to external fields such as electric, magnetic fields. The first experimental observation of dependence of isotropic to nematic phase transition on the applied magnetic field was done using a strong magnetic field on bent-core nematogens and the phase transition temperature exhibited an upshift of 0.7 C at B =30 T. We report on measurements of giant magnetic field-induced isotropic-nematic transition of chainsticks (nunchuks) type dimeric liquid crystals. Upon using the B =25 T split-helix resistive solenoid magnet at NHMFL, we have observed up to 18 C upshift of the isotropic to nematic phase transition temperature at B =22T. We discuss the results within the context of differential thermodynamic potential and the two basic mean-field theories. To our knowledge, this is the first observation of such huge shifts in the phase transitions of thermotropic liquid ctystals

  4. 2 T superconducting detector solenoid for the PANDA target spectrometer

    NASA Astrophysics Data System (ADS)

    Efremov, A. A.; Koshurnikov, E. K.; Lobanov, Y. Y.; Makarov, A. F.; Orth, H.; Sissakian, A. N.; Vodopianov, A. S.

    2008-02-01

    This paper describes the JINR design of the large 2 T superconducting solenoid for the target spectrometer of the PANDA experiment at HESR (FAIR, GSI, Darmstadt, Germany). The solenoid coil has an inner radius of 1.08 m and a length of 2.90 m. This solenoid is non-centrally split providing a warm bore of 100 mm in diameter through the coil to accommodate sufficient space for the internal target installations. Maximally stored energy in the windings is 22.3 MJ. All tracking and calorimetric detectors surrounding the target point, with exception of a forward cone of 5∘ opening, are placed inside the lqHe-cryostat. The main features of the design and technique are as follows: a copper stabilizer and soldering technique for the superconducting cable; a stainless steel cryostat; winding technique over a mandrel; coreless type of the coil; low operational current. The details of the PANDA solenoid design including the magnetic field and stress-strain calculations are covered.

  5. Magnetic field synthesis for microwave magnetics

    NASA Astrophysics Data System (ADS)

    Morgenthaler, F. R.

    1982-04-01

    The Microwave and Quantum Magnetics Group of the M.I.T. Department of Electrical Engineering and Computer Science undertook a two-year research program directed at developing synthesis procedures that allow magnetostatic and/or magnetoelastic modes to be specially tailored for microwave signal processing applications that include magnetically tunable filters and limiters as well as delay lines that are either linearly dispersive or nondispersive over prescribed bandwidths. Special emphasis was given to devices employing thin films of yttrium iron garnet (YIG) that are blessed with spatially nonuniform dc magnetic fields.

  6. COMPENSATION OF DETECTOR SOLENOID IN SUPER-B

    SciTech Connect

    Nosochkov, Yuri; Bertsche, Kirk; Sullivan, Michael; /SLAC

    2011-06-02

    The SUPER-B detector solenoid has a strong 1.5 T field in the Interaction Region (IR) area, and its tails extend over the range of several meters. The main effect of the solenoid field is coupling of the horizontal and vertical betatron motion which must be corrected in order to preserve the small design beam size at the Interaction Point. The additional effects are orbit and dispersion caused by the angle between the solenoid and beam trajectories. The proposed correction system provides local compensation of the solenoid effects independently for each side of the IR. It includes 'bucking' solenoids to remove the solenoid field tails and a set of skew quadrupoles, dipole correctors and anti-solenoids to cancel linear perturbations to the optics. Details of the correction system are presented.

  7. First Generation Final Focusing Solenoid For NDCX-I

    SciTech Connect

    Seidl, P. A.; Waldron, W.

    2011-11-09

    This report describes the prototype final focus solenoid (FFS-1G), or 1st generation FFS. In order to limit eddy currents, the solenoid winding consists of Litz wire wound on a non-conductive G-10 tube. For the same reason, the winding pack was inserted into an electrically insulating, but thermally conducting Polypropylene (Cool- Poly© D1202) housing and potted with highly viscous epoxy (to be able to wick the single strands of the Litz wire). The magnet is forced-air cooled through cooling channels. The magnet was designed for water cooling, but he cooling jacket cracked, and therefore cooling (beyond natural conduction and radiation) was exclusively by forced air. Though the design operating point was 8 Tesla, for the majority of running on NDCX-1 it operated up to about 5 Tesla. This was due mostly from limitations of voltage holding at the leads, where discharges at higher pulsed current damaged the leads. Generation 1 was replaced by the 2nd generation solenoid (FFS-2G) about a year later, which has operated reliably up to 8 Tesla, with a better lead design and utilizes water cooling. At this point, FFS-1G was used for plasma source R&D by LBNL and PPPL. The maximum field for those experiments was reduced to 3 Tesla due to continued difficulty with the leads and because higher field was not essential for those experiments. The pulser for the final focusing solenoid is a SCR-switched capacitor bank which produces a half-sine current waveform. The pulse width is ~800us and a charge voltage of 3kV drives ~20kA through the magnet producing ~8T field.

  8. Magnetic field structure evolution in rotating magnetic field plasmas

    SciTech Connect

    Petrov, Yuri; Yang Xiaokang; Huang, T.-S.

    2008-07-15

    A study of magnetic field structure evolution during 40-ms plasma discharge has been performed in a new device with 80 cm long/40 cm diameter cylindrical chamber, in which a plasma current I{sub p}{approx_equal}2 kA was driven and sustained by a rotating magnetic field. The main focus of the experiments is on how the changes in externally applied magnetic field affect the current profile and magnetic field in plasma. During plasma discharge, a pulse current was briefly fed to a magnetic coil located at the midplane (middle coil). The magnetic field in cross section of plasma was scanned with pickup probes. Two regimes were studied: without and with an external toroidal field (TF) produced by axial I{sub z} current. With a relatively small current (I{sub m} {<=} 600 A) in the middle coil, the plasma current is boosted up to 5 kA. The magnetic flux surfaces become extended along the axial Z direction, sometimes with the formation of doublet shape plasma. The regime without TF appears to be less stable, presumably due to the reversal of plasma current in central area of plasma column.

  9. Electrostatic ion acceleration across a diverging magnetic field

    NASA Astrophysics Data System (ADS)

    Ichihara, D.; Uchigashima, A.; Iwakawa, A.; Sasoh, A.

    2016-08-01

    Electrostatic ion acceleration across a diverging magnetic field, which is generated by a solenoid coil, permanent magnets, and a yoke between an upstream ring anode and a downstream off-axis hollow cathode, is investigated. The cathode is set in an almost magnetic-field-free region surrounded by a cusp. Inside the ring anode, an insulating wall is set to form an annular slit through which the working gas is injected along the anode inner surface, so the ionization of the working gas is enhanced there. By supplying 1.0 Aeq of argon as working gas with a discharge voltage of 225 V, the ion beam energy reached about 60% of a discharge voltage. In spite of this unique combination of electrodes and magnetic field, a large electrical potential drop is formed almost in the axial direction, located slightly upstream of the magnetic-field-free region. The ion beam current almost equals the equivalent working gas flow rate. These ion acceleration characteristics are useful for electric propulsion in space.

  10. PREPROCESSING MAGNETIC FIELDS WITH CHROMOSPHERIC LONGITUDINAL FIELDS

    SciTech Connect

    Yamamoto, Tetsuya T.; Kusano, K.

    2012-06-20

    Nonlinear force-free field (NLFFF) extrapolation is a powerful tool for the modeling of the magnetic field in the solar corona. However, since the photospheric magnetic field does not in general satisfy the force-free condition, some kind of processing is required to assimilate data into the model. In this paper, we report the results of new preprocessing for the NLFFF extrapolation. Through this preprocessing, we expect to obtain magnetic field data similar to those in the chromosphere. In our preprocessing, we add a new term concerning chromospheric longitudinal fields into the optimization function proposed by Wiegelmann et al. We perform a parameter survey of six free parameters to find minimum force- and torque-freeness with the simulated-annealing method. Analyzed data are a photospheric vector magnetogram of AR 10953 observed with the Hinode spectropolarimeter and a chromospheric longitudinal magnetogram observed with SOLIS spectropolarimeter. It is found that some preprocessed fields show the smallest force- and torque-freeness and are very similar to the chromospheric longitudinal fields. On the other hand, other preprocessed fields show noisy maps, although the force- and torque-freeness are of the same order. By analyzing preprocessed noisy maps in the wave number space, we found that small and large wave number components balance out on the force-free index. We also discuss our iteration limit of the simulated-annealing method and magnetic structure broadening in the chromosphere.

  11. The D0 solenoid NMR magnetometer

    SciTech Connect

    Sten Uldall Hansen Terry Kiper, Tom Regan, John Lofgren et al.

    2002-11-20

    A field monitoring system for the 2 Tesla Solenoid of the D0 detector is described. It is comprised of a very small NMR probe cabled to a DSP based signal processing board. The design magnetic field range is from 1.0 to 2.2 Tesla, corresponding to an RF frequency range of 42.57 to 93.67 MHz. The desired an accuracy is one part in 10{sup 5}. To minimize material in the interaction region of the D0 detector, the overall thickness of the NMR probe is 4 mm, including its mounting plate, and its width is 10 mm. To minimize cable mass, 4mm diameter IMR-100A cables are used for transmitting the RF signals from a nearby patch panel 25 meters to each of four probes mounted within the bore of the solenoid. RG213U cables 45 meters long are used to send the RF from the movable counting house to the patch panel. With this setup, the detector signal voltage at the moving counting room is in the range of 250-400 mV.

  12. Preliminary Test Results for the MICE Spectrometer Superconducting Solenoids

    SciTech Connect

    Virostek, Steve P.; Green, Michael A; Li, Derun; Zisman, Michael S.; Wang, S.T.; Wahrer, R.; Taylor, Clyde; Lu, X.; Chen, J. Y.; Wang, Mimi; Juang, Tiki

    2008-08-02

    This report describes the MICE spectrometer solenoids as built. Each magnet consists of five superconducting coils. Two coils are used to tune the beam going from or to the MICE spectrometer from the rest of the MICE cooling channel. Three spectrometer coils (two end coils and a long center coil) are used to create a uniform 4 T field (to {+-}0.3 percent) over a length of 1.0 m within a diameter of 0.3 m. The three-coil spectrometer set is connected in series. The two end coils use small power supplies to tune the uniform field region where the scintillating fiber tracker is located. This paper will present the results of the preliminary testing of the first spectrometer solenoid.

  13. Preliminary result of rapid solenoid for controlling heavy-ion beam parameters of laser ion source

    DOE PAGESBeta

    Okamura, M.; Sekine, M.; Ikeda, S.; Kanesue, T.; Kumaki, M.; Fuwa, Y.

    2015-03-13

    To realize a heavy ion inertial fusion driver, we have studied a possibility of laser ion source (LIS). A LIS can provide high current high brightness heavy ion beams, however it was difficult to manipulate the beam parameters. To overcome the issue, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The rapid ramping magnetic field could enhance limited time slice of the current and simultaneously the beam emittance changed accordingly. This approach may also useful to realize an ion source for HIF power plant.

  14. Rotating superconductor magnet for producing rotating lobed magnetic field lines

    DOEpatents

    Hilal, Sadek K.; Sampson, William B.; Leonard, Edward F.

    1978-01-01

    This invention provides a rotating superconductor magnet for producing a rotating lobed magnetic field, comprising a cryostat; a superconducting magnet in the cryostat having a collar for producing a lobed magnetic field having oppositely directed adjacent field lines; rotatable support means for selectively rotating the superconductor magnet; and means for energizing the superconductor magnet.

  15. Laser-generated magnetic fields in quasi-hohlraum geometries

    NASA Astrophysics Data System (ADS)

    Pollock, Bradley; Turnbull, David; Ross, Steven; Hazi, Andrew; Ralph, Joseph; Lepape, Sebastian; Froula, Dustin; Haberberger, Dan; Moody, John

    2014-10-01

    Laser-generated magnetic fields of 10--40 T have been produced with 100--4000 J laser drives at Omega EP and Titan. The fields are generated using the technique described by Daido et al. [Phys. Rev. Lett. 56, 846 (1986)], which works by directing a laser through a hole in one plate to strike a second plate. Hot electrons generated in the laser-produced plasma on the second plate collect on the first plate. A strap connects the two plates allowing a current of 10 s of kA to flow and generate a solenoidal magnetic field. The magnetic field is characterized using Faraday rotation, b-dot probes, and proton radiography. Further experiments to study the effect of the magnetic field on hohlraum performance are currently scheduled for Omega. This work was performed under the auspices of the United States Department of Energy by the Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA-27344.

  16. Preflare magnetic and velocity fields

    NASA Technical Reports Server (NTRS)

    Hagyard, M. J.; Gaizauskas, V.; Chapman, G. A.; Deloach, A. C.; Gary, G. A.; Jones, H. P.; Karpen, J. T.; Martres, M.-J.; Porter, J. G.; Schmeider, B.

    1986-01-01

    A characterization is given of the preflare magnetic field, using theoretical models of force free fields together with observed field structure to determine the general morphology. Direct observational evidence for sheared magnetic fields is presented. The role of this magnetic shear in the flare process is considered within the context of a MHD model that describes the buildup of magnetic energy, and the concept of a critical value of shear is explored. The related subject of electric currents in the preflare state is discussed next, with emphasis on new insights provided by direct calculations of the vertical electric current density from vector magnetograph data and on the role of these currents in producing preflare brightenings. Results from investigations concerning velocity fields in flaring active regions, describing observations and analyses of preflare ejecta, sheared velocities, and vortical motions near flaring sites are given. This is followed by a critical review of prevalent concepts concerning the association of flux emergence with flares

  17. AC photovoltaic module magnetic fields

    SciTech Connect

    Jennings, C.; Chang, G.J.; Reyes, A.B.; Whitaker, C.M.

    1997-12-31

    Implementation of alternating current (AC) photovoltaic (PV) modules, particularly for distributed applications such as PV rooftops and facades, may be slowed by public concern about electric and magnetic fields (EMF). This paper documents magnetic field measurements on an AC PV module, complementing EMF research on direct-current PV modules conducted by PG and E in 1993. Although not comprehensive, the PV EMF data indicate that 60 Hz magnetic fields (the EMF type of greatest public concern) from PV modules are comparable to, or significantly less than, those from household appliances. Given the present EMF research knowledge, AC PV module EMF may not merit considerable concern.

  18. Magnetic Field of Strange Dwarfs

    NASA Astrophysics Data System (ADS)

    Baghdasaryan, D. S.

    2016-03-01

    The generation of a magnetic field in a strange quark star owing to differential rotation of the superfluid and superconducting quark core relative to the normal electron-nuclear crust of the star is examined. The maximum possible magnetic field on the surface is estimated for various models of strange dwarfs. Depending on the configuration parameters, i.e., the mass M and radius R of the star, a range of 103-105 G is found. These values of the magnetic field may be an additional condition for identification of strange dwarfs among the extensive class of observed white dwarfs.

  19. Magnetic fields and scintillator performance

    SciTech Connect

    Green, D.; Ronzhin, A.; Hagopian, V.

    1995-06-01

    Experimental data have shown that the light output of a scintillator depends on the magnitude of the externally applied magnetic fields, and that this variation can affect the calorimeter calibration and possibly resolution. The goal of the measurements presented here is to study the light yield of scintillators in high magnetic fields in conditions that are similar to those anticipated for the LHC CMS detector. Two independent measurements were performed, the first at Fermilab and the second at the National High Magnetic Field Laboratory at Florida State University.

  20. Magnetoconvection in sheared magnetic fields

    SciTech Connect

    Bian, N. H.; Garcia, O. E.

    2008-10-15

    The development of magnetoconvection in a sheared magnetic field is investigated. The equilibrium magnetic field B{sub 0} is horizontal and its orientation varies linearly along the vertical axis. Preliminary consideration of the transition from the inertial to the viscous regime of the gravitational resistive interchange instability, reveals that the latter is characterized by the existence of viscoresistive boundary layers of vertical width which scales as Q{sup -1/6}, where Q is the Chandrasekhar number. The situation is analogous to the one encountered in magnetically confined laboratory plasmas, where convective flows are constrained by the magnetic shear to develop in boundary layers located around resonant magnetic surfaces in order to fulfill the 'interchange condition'k{center_dot}B{sub 0}=0, where k is the wave vector of the magnetic perturbation. It follows that when the effect of thermal diffusion is taken into account in the process, convection can only occur above a certain critical value of the Rayleigh number which scales as Q{sup 2/3} for large Q. At the onset, the convection pattern is a superposition of identically thin convective rolls everywhere aligned with the local magnetic field lines and which therefore adopt the magnetic field geometry, a situation also reminiscent of the penumbra of sunspots. Using this degeneracy, equations describing the weakly nonlinear state are obtained and discussed. A reduced magnetohydrodynamic description of magnetoconvection is introduced. Since it is valid for arbitrary magnetic field configurations, it allows a simple extension to the case where there exists an inclination between the direction of gravity and the plane spanned by the equilibrium magnetic field. These reduced magnetohydrodynamic equations are proposed as a powerful tool for further investigations of magnetoconvection in more complex field line geometries.

  1. Superconducting solenoids for the MICE channel

    SciTech Connect

    Green, M.A.; Barr, G.; Baynham, D.E.; Rockford, J.H.; Fabbricatore, P.; Farinin, S.; Palmer, R.B.; Rey, J.M.

    2003-05-01

    This report describes the channel of superconductingsolenoids for the proposed international Muon Ionization CoolingExperiment (MICE). MICE consists of two cells of a SFOFO cooling channelthat is similar to that studied in the level 2 study of a neutrinofactory[1]. MICE also consists of two detector solenoids at either end ofthe cooling channel section. The superconducting solenoids for MICEperform three functions. The coupling solenoids, which are largesolenoids around 201.25 MHz RF cavities, couple the muon beam between thefocusing sections as it passes along the cooling channel. The focusingsolenoids are around the liquid hydrogen absorber that reduces themomentum of the muons in all directions. These solenoids generate agradient field along the axis as they reduce the beta of the muon beambefore it enters the absorber. Each detector solenoid system consists offive coils that match the muon beam coming to or from an absorber to a4.0 T uniform solenoidal field section that that contains the particledetectors at the ends of the experiment. There are detector solenoids atthe beginning and at the end of the experiment. This report describes theparameters of the eighteen superconducting coils that make up the MICEmagnetic channel.

  2. A Sub-Millimeter Solenoid Device for Trapping Paramagnetic Microbeads

    SciTech Connect

    Garcia, L D; Cheung, L C; Mikkelsen, J C; Santiago, J G; bernhardt, A F; Malba, V

    2001-08-01

    We present the design and preliminary evaluation of a paramagnetic microsphere trapping and separation device consisting of a copper solenoid wrapped around a 1.3 mm diameter glass capillary. The magnetization and subsequent dipole-dipole interaction of paramagnetic spheres under an applied magnetic field results in the formation of bead chains that persist and grow under the applied field, but quickly disperse upon field removal. The chaining of paramagnetic spheres is important to the design of magnetic-based separation devices because the viscous-drag-limited velocities of chains are typically several times larger than that of individual particles. We have performed a set of experiments designed to evaluate the performance of a sub-millimeter solenoid device including measurements of the temperature versus field strength of the device, observations of the controlled chain formation process, and preliminary observations regarding the maximum flow rate over which the bead chains can be held in place by magnetic forces. These results are applicable to the design and characterization of magnetically induced microsphere trapping and separation systems which use pressure driven flow.

  3. Enhanced trapped field performance of bulk high-temperature superconductors using split coil, pulsed field magnetization with an iron yoke

    NASA Astrophysics Data System (ADS)

    Ainslie, M. D.; Fujishiro, H.; Mochizuki, H.; Takahashi, K.; Shi, Y.-H.; Namburi, D. K.; Zou, J.; Zhou, D.; Dennis, A. R.; Cardwell, D. A.

    2016-07-01

    Investigating and predicting the magnetization of bulk superconducting materials and developing practical magnetizing techniques is crucial to using them as trapped field magnets in engineering applications. The pulsed field magnetization (PFM) technique is considered to be a compact, mobile and relative inexpensive way to magnetize bulk samples, requiring shorter magnetization times (on the order of milliseconds) and a smaller and less complicated magnetization fixture; however, the trapped field produced by PFM is generally much smaller than that of slower zero field cooling or field cooling techniques, particularly at lower operating temperatures. In this paper, the PFM of two, standard Ag-containing Gd–Ba–Cu–O samples is carried out using two types of magnetizing coils: (1) a solenoid coil, and (2) a split coil, both of which make use of an iron yoke to enhance the trapped magnetic field. It is shown that a significantly higher trapped field can be achieved using a split coil with an iron yoke, and in order to explain these how this arrangement works in detail, numerical simulations using a 2D axisymmetric finite element method based on the H -formulation are carried to qualitatively reproduce and analyze the magnetization process from both electromagnetic and thermal points of view. It is observed that after the pulse peak significantly less flux exits the bulk when the iron core is present, resulting in a higher peak trapped field, as well as more overall trapped flux, after the magnetization process is complete. The results have important implications for practical applications of bulk superconductors as such a split coil arrangement with an iron yoke could be incorporated into the design of a portable, high magnetic field source/magnet to enhance the available magnetic field or in an axial gap-type bulk superconducting electric machine, where iron can be incorporated into the stator windings to (1) improve the trapped field from the magnetization

  4. Bioluminescence under static magnetic fields

    NASA Astrophysics Data System (ADS)

    Iwasaka, M.; Ueno, S.

    1998-06-01

    In the present study, the effect of magnetic fields on the emission of light by a living system was studied. The fireflies Hotaria parvula and Luciola cruciata were used as the bioluminescence systems. The firefly light organ was fixed at the edge of an optical fiber. The emitted light was introduced into a single-channel photon-counting system using an optical fiber. We measured both the spectrum of a constant light emission and, the time course of bioluminescence pulses. Two horizontal-type superconducting magnets, which produced 8 and 14 T magnetic fields at their center, were used as the magnetic-field generators. We also carried out an in vitro study of bioluminescence. The enzymatic activity of luciferase was measured under a 14 T magnetic field. We measured emission spectra of bioluminescence over the interval 500-600 nm at 25 °C in a stable emission state. It was observed that the peak wavelength around 550 nm shifted to 560 nm under a 14 T magnetic field. However, the effects of magnetic fields were not significant. Also, we measured the time course of emissions at 550 nm in a transient emission state. The rate in the light intensity under a 14 T magnetic field increased compared to the control. There is a possibility that the change in the emission intensities under a magnetic field is related to a change in the biochemical systems of the firefly, such as the enzymatic process of luciferase and the excited singlet state with subsequent light emission.

  5. Magnetic field structure of Mercury

    NASA Astrophysics Data System (ADS)

    Hiremath, K. M.

    2012-04-01

    Recently planet Mercury - an unexplored territory in our solar system - has been of much interest to the scientific community due to recent flybys of the spacecraft MESSENGER that discovered its intrinsic stationary and large-scale dipole like magnetic field structure with an intensity of ˜300nT confirming Mariner 10 observations. In the present study, with the observed constraint of Mercury's atmospheric magnetic field structure, internal magnetic field structure is modeled as a solution of magnetic diffusion equation. In this study, Mercury's internal structure mainly consists of a stable stratified fluid core and the convective mantle. For simplicity, magnetic diffusivity in both parts of the structure is considered to be uniform and constant with a value represented by a suitable averages. It is further assumed that vigorous convection in the mantle disposes of the electric currents leading to a very high diffusivity in that region. Thus, in order to satisfy observed atmospheric magnetic field structure, Mercury's most likely magnetic field structure consists of a solution of MHD diffusion equation in the core and a combined multipolar (dipole and quadrupole like magnetic field structures embedded in the uniform field) solution of a current free like magnetic field structure in the mantle and in the atmosphere. With imposition of appropriate boundary conditions at the core-mantle boundary for the first two diffusion eigen modes, in order to satisfy the observed field structure, present study puts the constraint on Mercury's core radius to be ˜2000km. From the estimated magnetic diffusivity and the core radius, it is also possible to estimate the two diffusion eigen modes with their diffusion time scales of ˜8.6 and 3.7 billion years respectively suggesting that the planet inherits its present-day magnetic field structure from the solar Nebula. It is proposed that permanency of such a large-scale magnetic field structure of the planet is attained during

  6. Magnetic Field Generation in Stars

    NASA Astrophysics Data System (ADS)

    Ferrario, Lilia; Melatos, Andrew; Zrake, Jonathan

    2015-10-01

    Enormous progress has been made on observing stellar magnetism in stars from the main sequence (particularly thanks to the MiMeS, MAGORI and BOB surveys) through to compact objects. Recent data have thrown into sharper relief the vexed question of the origin of stellar magnetic fields, which remains one of the main unanswered questions in astrophysics. In this chapter we review recent work in this area of research. In particular, we look at the fossil field hypothesis which links magnetism in compact stars to magnetism in main sequence and pre-main sequence stars and we consider why its feasibility has now been questioned particularly in the context of highly magnetic white dwarfs. We also review the fossil versus dynamo debate in the context of neutron stars and the roles played by key physical processes such as buoyancy, helicity, and superfluid turbulence, in the generation and stability of neutron star fields.

  7. Designing focusing solenoids for superconducting RF accelerators

    SciTech Connect

    Davis, G.; Kashikhin, V.V.; Page, T.; Terechkine, I.; Tompkins, J.; Wokas, T.; /Fermilab

    2006-08-01

    The design of a focusing solenoid for use in a superconducting RF linac requires resolving a range of problems with conflicting requirements. Providing the required focusing strength contradicts the goal of minimizing the stray field on the surfaces of adjacent superconducting RF cavities. The requirement of a compact solenoid, able to fit into a gap between cavities, contradicts the need of mechanical support necessary to restrain electromagnetic forces that can result in coil motion and subsequent quenching. In this report we will attempt to address these and other issues arising during the development of focusing solenoids. Some relevant test data will also be presented.

  8. Measuring Earth's Magnetic Field Simply.

    ERIC Educational Resources Information Center

    Stewart, Gay B.

    2000-01-01

    Describes a method for measuring the earth's magnetic field using an empty toilet paper tube, copper wire, clear tape, a battery, a linear variable resistor, a small compass, cardboard, a protractor, and an ammeter. (WRM)

  9. RF breakdown of 805 MHz cavities in strong magnetic fields

    SciTech Connect

    Bowring, D.; Stratakis, D.; Kochemirovskiy, A.; Leonova, M.; Moretti, A.; Palmer, M.; Peterson, D.; Yonehara, K.; Freemire, B.; Lane, P.; Torun, Y.; Haase, A.

    2015-05-03

    Ionization cooling of intense muon beams requires the operation of high-gradient, normal-conducting RF structures in the presence of strong magnetic fields. We have measured the breakdown rate in several RF cavities operating at several frequencies. Cavities operating within solenoidal magnetic fields B > 0.25 T show an increased RF breakdown rate at lower gradients compared with similar operation when B = 0 T. Ultimately, this breakdown behavior limits the maximum safe operating gradient of the cavity. Beyond ionization cooling, this issue affects the design of photoinjectors and klystrons, among other applications. We have built an 805 MHz pillbox-type RF cavity to serve as an experimental testbed for this phenomenon. This cavity is designed to study the problem of RF breakdown in strong magnetic fields using various cavity materials and surface treatments, and with precise control over sources of systematic error. We present results from tests in which the cavity was run with all copper surfaces in a variety of magnetic fields.

  10. The magnetic field of Mercury

    NASA Technical Reports Server (NTRS)

    Ness, N. F.

    1977-01-01

    The Mariner 10 spacecraft encountered Mercury three times in 1974-1975. The first and third encounters provided detailed observations of a well-developed detached bow shock wave which results from the interaction of the solar wind. The planet possesses a global magnetic field and a modest magnetosphere, which deflects the solar wind. The field is approximately dipolar, with orientation in the same sense as earth, tilted 12 deg from the rotation axis. The magnetic moment corresponds to an undistorted equatorial field intensity of 350 gammas, approximately 1% of earth's. The field, while unequivocally intrinsic to the planet, may be due to remanent magnetization acquired from an extinct dynamo or a primordial magnetic field or due to a presently active dynamo. The latter possibility appears more plausible at present. In any case, the existence of the magnetic field provides very strong evidence of a mature differentiated planetary interior with a large core (core radius about 0.7 Mercury radius) and a record of the history of planetary formation in the magnetization of the crustal rocks.