Showing papers on "Solenoid published in 2013"

The physics of tokamak start-upa)

Abstract: Tokamak start-up on present-day devices usually relies on inductively induced voltage from a central solenoid. In some cases, inductive startup is assisted with auxiliary power from electron cyclotron radio frequency heating. International Thermonuclear Experimental Reactor, the National Spherical Torus Experiment Upgrade and JT60, now under construction, will make use of the understanding gained from present-day devices to ensure successful start-up. Design of a spherical tokamak (ST) with DT capability for nuclear component testing would require an alternative to a central solenoid because the small central column in an ST has insufficient space to provide shielding for the insulators in the solenoid. Alternative start-up techniques such as induction using outer poloidal field coils, electron Bernstein wave start-up, coaxial helicity injection, and point source helicity injection have been used with success, but require demonstration of scaling to higher plasma current.

Status of Conductor Qualification for the ITER Central Solenoid

Abstract: The ITER central solenoid (CS) must be capable of driving inductively 30 000 15 MA plasma pulses with a burn duration of 400 s. This implies that during the lifetime of the machine, the CS, comprised of six independently powered coil modules, will have to sustain severe and repeated electromagnetic cycles to high current and field conditions. The design of the CS calls for the use of cable-in-conduit conductors made up of and pure copper strands, assembled in a five-stage, rope-type cable around a central cooling spiral that is inserted into a circle-in-square jacket made up of a special grade of high manganese stainless steel. Since cable-in-conduit conductors are known to exhibit electromagnetic cycling degradation, prior to the launch of production, the conductor design and potential suppliers must be qualified through the successful testing of full-size conductor samples. These tests are carried out at the SULTAN test facility. In this paper, we report the results of the on-going CS conductor performance qualification and we present the options under consideration for the different modules constituting the CS coil.

Design Features and Commissioning of the Versatile Experiment Spherical Torus (VEST) at Seoul National University

Abstract: A new spherical torus called VEST (Versatile Experiment Spherical Torus) is designed, constructed and successfully commissioned at Seoul National University. A unique design feature of the VEST is two partial solenoid coils installed at both vertical ends of a center stack, which can provide sufficient magnetic fluxes to initiate tokamak plasmas while keeping a low aspect ratio configuration in the central region. According to initial double null merging start-up scenario using the partial solenoid coils, appropriate power supplies for driving a toroidal field coil, outer poloidal field coils, and the partial solenoid coils are fabricated and successfully commissioned. For reliable start-up, a pre-ionization system with two cost-effective homemade magnetron power supplies is also prepared. In addition, magnetic and spectroscopic diagnostics with appropriate data acquisition and control systems are well prepared for initial operation of the device. The VEST is ready for tokamak plasma operation by completing and commissioning most of the designed components.

High-Bandwidth Low-Insertion Loss Solenoid Transformers Using FeCoB Multilayers

Abstract: High-bandwidth low-insertion loss solenoid transformers using a multilayered FeCoB magnetic core have been designed, modeled, fabricated, and characterized for high-frequency power conversion. Various transformer designs are compared in terms of inductance, resistance, quality factor, mutual coupling, and insertion loss. A mutual coupling coefficient of 0.9 up to 50 MHz is achieved for intertwined solenoid transformers with a patterned magnetic core.

Drive device for fuel injection device, and fuel injection system

Abstract: A drive device capable of detecting individual variations of an injection quantity of a fuel injection device of each cylinder and adjusting a current waveform provided to an injection pulse width and a solenoid such that the individual variations of the fuel injection devices are reduced. The fuel injection device in the present invention includes a valve body 114 that closes a fuel passage by coming into contact with a valve seat 118 and opens the fuel passage by separating from the valve seat 118 and a magnetic circuit constructed of a solenoid 105, a fixed core 107, a nozzle holder 101, a housing 103, and a needle 102 and when a current is supplied to the solenoid 105, a magnetic suction force acts on the needle 102 and the needle 102 has a function to open the valve body 114 by colliding against the valve body 114 after performing a free running operation and changes of acceleration of the needle 102 due to collision of the needle 102 against the valve body 114 are detected by a current flowing through the solenoid 105.

Single-knob beam line for transverse emittance partitioning

Abstract: Flat beams feature unequal emittances in the horizontal and vertical phase space. Such beams were created successfully in electron machines by applying effective stand-alone solenoid fringe fields in the electron gun. Extension of this method to ion beams was proposed conceptually. The present paper is on the decoupling capabilities of an ion beam emittance transfer line. The proposed beam line provides a single-knob tool to partition the horizontal and vertical rms emittances, while keeping the product of the two emittances constant as well as the transverse rms Twiss parameters (αx,y and βx,y) in both planes. It is shown that this single knob is the solenoid field strength.

Surface-scanning coil detectors for magnetoelastic biosensors: A comparison of planar-spiral and solenoid coils

Abstract: This research introduces a planar spiral coil as a surface-scanning detector for magnetoelastic biosensors, which have been used to detect bacteria directly on food surfaces. The planar coil was compared with the previously investigated solenoid coil, in terms of the magnetic flux change, signal amplitude, and detection distance. Both theoretical calculations and experimental results demonstrated that the planar coil detector yields a dramatically improved signal amplitude and greater detection distance. In addition, simultaneous measurement of multiple biosensors on surfaces was demonstrated. This planar coil is therefore anticipated to facilitate the detection of bacteria on surfaces using magnetoelastic biosensors.

Bilateral Control of Nonlinear Pneumatic Teleoperation System With Solenoid Valves

Abstract: In past research on the control of pneumatic actuators, typically proportional servovalves have been used for achieving high-performance control of the mass flow rate. In this brief, we instead use fast-switching ON/OFF valves due to their distinct advantages in terms of low cost and small size. Accurate control of pneumatic actuators with ON/OFF solenoid valves is a challenge since the system dynamics is both discrete input and highly nonlinear. In this brief, we apply a hybrid control algorithm to a pneumatic actuator with ON/OFF valves. Such a control approach is developed for choosing the best control vector at each sample time to track the reference state (i.e., desired force) in the inner force control loop within a bilateral teleoperation system. Experimental results show that good teleoperation transparency is achieved despite all the obstacles such as discrete input and nonlinear behavior of the pneumatic-actuated teleoperation system.

Non-inductive plasma start-up on NSTX and projections to NSTX-U using transient CHI

Abstract: Transient coaxial helicity injection (CHI) in the National Spherical Torus Experiment (NSTX) has generated toroidal current on closed-flux surfaces without the use of the central solenoid. When induction from the central solenoid was added, CHI initiated discharges in NSTX achieved 1 MA of plasma current using 65% of the solenoid flux of standard induction-only discharges. In addition, the CHI-initiated discharges have lower density and a low normalized internal plasma inductance of 0.35, as desired for achieving advanced scenarios. Transient CHI will be used for non-inductive plasma start-up on the upgrade to NSTX (NSTX-U) that is now under construction. It will have numerous improvements that significantly enhance CHI start-up capability. The TSC code is now starting to be used for full discharge simulation, which includes solenoid-less start-up with CHI and subsequent non-inductive current ramp-up using neutral beams. These results suggest that the increased injector flux capability of NSTX-U should allow CHI start-up at more than the 400 kA level and that the new tangential neutral beam system on NSTX-U should be able to ramp the current to the 1 MA levels.

Performance of solenoids versus quadrupoles in focusing and energy selection of laser accelerated protons

Abstract: Using laser accelerated protons or ions for various applications---for example in particle therapy or short-pulse radiographic diagnostics---requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. Generally speaking, the two approaches are equivalent in focusing capability, if parameters are such that the solenoid length approximately equals its diameter. The scaling also shows that this is usually not the case above a few MeV; consequently, a solenoid needs to be pulsed or superconducting, whereas the quadrupoles can remain conventional. It is also important that the transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for energy selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al. [Phys. Rev. Lett. 103, 135001 (2009].

Experimental Results From a 4-Stage Synchronous Induction Coilgun

Abstract: To demonstrate the multistage induction launch capability and test the accuracy of the simulation result, a small-scale, 4-stage synchronous induction coilgun is designed, fabricated, and tested based on the simulation result. The four coils are stacked end-to-end, forming a barrel, and each coil is energized by the identical pulsed power supply in sequence to create a traveling magnetic wave that accelerates a projectile. The inductance of four coils is tailored by changing the number of turns in order to decrease the pulsed current risetime. The tracking of the projectile location during a launching provides a precise feedback to control when the coils are triggered to create the wave. Two types of the projectiles are tested. A 0.65-kg sleeve projectile is accelerated from rest to 125 m/s with a projectile kinetic energy to capacitor-stored energy efficiency of 6%. A 1-kilogram sleeve projectile is accelerated from rest to 92 m/s with the efficiency of 5%. The solenoid projectile is broken at the bending point when it induces high current. The launcher provides data for model verification and the engineering basis for proceeding with larger multistage system. Further research is to improve the system efficiency and maximize the magnetic coupling between the driving coil and the projectile.

Development of Central Solenoid for JT-60SA

Abstract: Several components for central solenoid (CS) of JT-60 Super Advanced (JT-60SA) were newly developed and tested. The butt-type joint, the electrical resistance of which is about 2 nΩ, was developed to increase the winding diameter. The insulation system, which consists of Glass/Kapton/Glass tape and Bisphenol A diglycidyl ether (DGEBA) epoxy, showed sufficient tensile strength after the irradiation of 100 kGy. Insulation characteristics of 4 × 4 winding stack sample after the compression of 705 kN 36 000 times was able to withstand voltages larger than 21 kV. The heat treatment and transfer of the CS model coil with superconductor were conducted. The pancake temperature during flat top was maintained at 923 ± 4 K. The maximum temperature difference in the pancake was 30 K. All manufacturing processes were confirmed so that the mass production of CS will be started in 2013.

Six-Beam Gun Design for a High Power Multiple-Beam Klystron

Abstract: This paper presents the detailed design of a six-beam gun for use in an L-band 10-MW multiple-beam klystron. To facilitate the gun simulation, we developed a joint design methodology with 2-D and 3-D simulation codes. The six-beam gun is designed to produce a total current of 132 A divided equally among the six beams at an accelerating potential of 115 kV. For the design of the gun, special emphasis is placed on the geometric layout of the electrodes to ensure moderate voltage gradient, accurate beam perveance and reasonable cathode loading. The magnetic circuit consists of solenoid magnet structures. Special coils and iron shells are set to ensure a uniform parallel magnetic field in the region between the cathode and the anode. Two set of amendatory coils and shield irons are set in the transition region to optimize the beam radius. Special coils are set in the both ends of the interaction region to trim the radial magnetic fields. The gun design is accomplished with EGUN and CST codes. Simulation results show that the joint design methodology is effective and the magnetic circuit has an excellent flexibility. The final gun has a cathode loading lower than 2.1 A/cm2 and excellent beam transport characteristics. The dependency relationship between the beam off-centering and the asymmetry radial magnetic fields is analyzed.

Method to reduce non-specific tissue heating of small animals in solenoid coils

Abstract: Purpose: Solenoid coils that generate time-varying or alternating magnetic fields (AMFs) are used in biomedical devices for research, imaging and therapy. Interactions of AMF and tissue produce eddy currents that deposit power within tissue, thus limiting effectiveness and safety. We aim to develop methods that minimise excess heating of mice exposed to AMFs for cancer therapy experiments.Materials and methods: Numerical and experimental data were obtained to characterise thermal management properties of water using a continuous, custom water jacket in a four-turn simple solenoid. Theoretical data were obtained with method-of-moments (MoM) numerical field calculations and finite element method (FEM) thermal simulations. Experimental data were obtained from gel phantoms and mice exposed to AMFs having amplitude >50 kA/m and frequency of 160 kHz.Results: Water has a high specific heat and thermal conductivity, is diamagnetic, polar, and nearly transparent to magnetic fields. We report at least a two-fold re...

Ultra slow muon microscopy by laser resonant ionization at J-PARC, MUSE

Abstract: As one of the principal muon beam line at the J-PARC muon facility (MUSE), we are now constructing a Muon beam line (U-Line), which consists of a large acceptance solenoid made of mineral insulation cables (MIC), a superconducting curved transport solenoid and superconducting axial focusing magnets. There, we can extract 2 × 108/s surface muons towards a hot tungsten target. At the U-Line, we are now establishing a new type of muon microscopy; a new technique with use of the intense ultra-slow muon source generated by resonant ionization of thermal Muonium (designated as Mu; consisting of a μ + and an e − ) atoms generated from the surface of the tungsten target. In this contribution, the latest status of the Ultra Slow Muon Microscopy project, fully funded, is reported.

Integrated Transformers With Sputtered Laminated Magnetic Core

Abstract: Integrated interleaved solenoid transformers with a single layer of laminated magnetic core have been designed and fabricated. A coupling coefficient of > 0.97 was achieved for a device with a primary and secondary inductance of 565 nH, which represents an enhancement of more than 60 times that of air core inductors of identical geometry. By using the laminated magnetic core structure, the quality factor of the primary or secondary inductance was increased to a peak value of 6.3 with 3 μm thick electroplated copper coils. Measured characteristics of the integrated transformers agree very well with simulation results for values of self-resonant frequency, inductance, quality factor, and coupling coefficient.

Development of Extended Heating Pulse Operation Mode at GOL-3

Abstract: Novel technology of electron beam generation for plasma heating in GOL-3 was developed and for the first time used in the experiment The distinctive features of the new beam are non-relativistic energy, medium power and sub-ms duration The experiments were done at the following beam and plasma parameters: ~100 keV, ~10 MW, >100 μs, ~1020 m-3 The beam was safely transported through the 13-m-long deuterium-filled multiple-mirror solenoid The plasma was created and then heated by the beam Main physical task for the reported experiments was to reach quasi-stationary plasma conditions during the long-pulse beam injection

Novel Electromagnetic Actuator Using a Permanent Magnet and an Inter-Locking Mechanism for a Magnetic Switch

Abstract: The solenoid magnetic actuator has been widely used as an actuator for MS (magnetic switch). Thus, conventional MSs continuously consume electrical power to maintain a closed state. To address this problem, an innovative structure which uses a permanent magnet to generate holding force in the closed state without electrical power is suggested in this paper. Further, the permanent magnet is dedicated to the opening operation and the closing operation by means of its magnetic force. In other words, an eco-friendly MS is proposed in this research. However, this structure has a critical problem in that, if unexpected external force is applied to the MS when in the open state, the MS returns to the closed state by the force of the permanent magnet and remains in the closed state, causing an unintended operation of the load. To solve this problem, a novel inter-locking mechanism is proposed. Hence, we termed the proposed novel MS the MSPI (magnetic switch using a permanent magnet and an inter-locking system). In addition, analysis and design methods for the MSPI are proposed in this paper. The usefulness of the MSPI and the accuracy of the analysis and design methods are confirmed through an experiment.

Special Coils Development at the National High Magnetic Field Laboratory in Toulouse

Abstract: The Laboratoire National des Champs Magnetiques Intenses (LNCMI) develops different types of coils suited to specific experiments. We present some recent developments on magnet design. Several coils are dedicated to experiments in large scale facilities in France and Switzerland. A 30 T split-pair coil for X-rays diffraction and one 40 T coil for plasma physics at the LULI, two 30 T coils with axial access (one with an conical bore) for X-ray diffraction and absorption experiments. A 40 T wide angle conical access solenoid with a high duty-cycle for neutron scattering at the ILL is being constructed. For use at the installation in Toulouse we have developed, apart from our standard 60 and 70 T coils, several special coils: a coil with a long optical path with 30 T transverse magnetic field and a 90 T long pulse dual coil system.

Household gas cooker wireless monitoring system

Abstract: The invention discloses a household gas cooker wireless monitoring system which comprises a controller, a wireless transceiver module, a gas cooker ON-state detection unit for real-time detection of the ON state of a gas cooker, an inflammable gas concentration detection unit for real-time detection of the concentration of inflammable gas around the gas cooker, a remote wireless communication terminal for bidirectional communication through the wireless transceiver module and the controller, a clock circuit for automatic statistics of continuous working time of the gas cooker, a hand-operated parameter setting unit, an alarm unit, a solenoid electric valve, and a display unit; the solenoid electric valve is mounted at a gas supply pipe mounted at a gas inlet of the monitored gas cooker, and both the ON/OFF state and the opening degree of the solenoid electric valve are controlled by the controller. The invention is simple in structure, convenient for wiring, simple in operation, high in intelligentization degree, and good in application effect, and can solve the defects of low automation and intelligentization degrees, inconvenient usage and operation, indispensability of personal on-site hand-operated control by users, incapability of realizing remote intelligent monitoring, and the like for current gas cookers.

Design of the Superconducting Magnet System for the SuperKEKB Intercation Region

Abstract: SuperKEKB is the upgraded accelerator of KEKB aiming at an extremely high luminosity. The machine is designed on the basis of nano-beam scheme. The beam final focusing system is the most important element for achieving the luminosity of this accelerator. The system consists of 8 quadrupoles, 4 solenoids and 43 correctors. INTRODUCTION The target luminosity of SuperKEKB [1] is 40 times higher luminosity of 8×10 35 cm -2 s -1 than that of KEKB. The 7 GeV electrons in the high-energy ring (HER) and the 4 GeV positrons in the low-energy ring (LER) collide at a single interaction point, IP, with a finite crossing angle of 83 mrad. The accelerator is designed on the basis of the nanobeam scheme [2], and the final beam focusing system has been designed with superconducting quadrupole doublets for each beam. Since the positions of quadrupole magnets must be aligned very precisely within several nano meters, the alignment of quadrupoles is performed by the correctors [3]. In addition, from the requirement of beam optics, 43 corrector coils are installed in the system. The system has four compensation solenoids to reduce the effect of the detector solenoid field on the beams. All magnets and correctors are assembled into two cryostats. In the paper, the design of the system is described. SUPERCONDUCTING MAGNET SYSTEM Magnet Layout in the IR Figure 1 shows the layout of the superconducting magnets near the interaction point, IP [4]. The system consists of 8 main quadrupole magnets, 4 compensation solenoids, 35 corrector coils and 8 coils to cancel the leakage magnetic fields of QC1LP/RP. The main quadrupole magnets (QC1s and QC2s) are designed to form a quadrupole doublet for each beam. Table 1 shows the main parameters of the quadrupole magnets at the colliding energy of 11 GeV. The QC1LP/RP magnets are located at the closest position, +/935mm, to IP. They are quadrupole magnets without magnetic yokes in order to make the solenoid field profile for minimizing vertical beam emittance. The other quadrupole magnets have magnetic yokes. Since the QC1LP/RP magnets are non-yoked magnets, the leakage field from the magnets to the ebeam line contains all field components as shown in Fig. 2. In order to cancel these components, the B3, B4, B5 and B6 cancel coils [3] are wound using the helium inner vessel as the coil bobbin. A small twist of the windings which produce the normal cancel components also generates the needed skew cancel components. The B1 and B2 field components are included in the optics design. The compensation solenoids, ESL, ESR1, ESR2 and ESR3, are designed to cancel the Belle-II solenoid field integrally along the beam lines [5]. In the ESL and ESR1 solenoids, two or three quadrupoles are assembled, respectively, as shown in Fig. 1. In the right cryostat, the additional solenoids, ERS2 and ESR3, are also installed. Figure 1: Layout of S.C. magnets near the IP of SuperKEKB. Figure 2: Leakage field profiles along the ebeam line. Table 1: Main Quadrupole Parameters Magnet GL, T (T/m×m) Type Z, mm θ, mrad QC2RE 13.04 (31.12×0.419) Yoke 2925 0 QC2RP 11.54 (28.15×0.410) Yoke 1925 -2.114 QC1RE 25.39 (68.07×0.373) Yoke 1410 0 QC1RP 22.96 (68.74×0.334) no Yoke 935 7.204 QC1LP 22.96 (68.74×0.334) no Yoke -935 -13.65 QC1LE 26.94 (72.23×0.373) Yoke -1410 0 QC2LP 11.48 (28.00×0.410) Yoke -1925 -3.725 QC2LE 15.27 (28.44×0.537) Yoke -2700 0 GL is the integral field gradient (field gradient at center× effective magnetic length). ___________________________________________ #norihito.ohuchi@kek.jp Proceedings of PAC2013, Pasadena, CA USA WEODA1 07 Accelerator Technology T10 Superconducting Magnets ISBN 978-3-95450-138-0 759 C op yr ig ht c © 20 13 C C -B Y3. 0 an d by th e re sp ec tiv e au th or s Alignment of Q uadrupole Magnets In Table 1, the quadrupole centers from IP and the midplane angles to the horizontal plane are listed. The quadrupole magnets for LER are assembled with these angles in the cryostats. Since the solenoid field and the leakage field of QC1P magnets change the ebeam orbits, the beam orbits will be controlled by dipole correctors. In order to optimize the corrector system, the magnet axes of QC1s and QC2s are shifted as shown in Table 2. In the table, ∆Y is the shift amount in vertical direction from the horizontal plane including IP and the negative sign means downward. The plus ∆X means the horizontal shift toward the outer direction of the accelerator ring. Table 2: Shift Amount of Magnet Axis

Power transmission device

Abstract: PROBLEM TO BE SOLVED: To suppress abrasion of a valve body caused by pulsation of input pressure of a solenoid valve, and to suppress detachment of the solenoid valve from the valve body before an oil pressure control device is fixed to a transmission case in the oil pressure control device in which at least either of the solenoid valves is fixed to the transmission case together with the valve body.SOLUTION: A first solenoid valve S1 has a first bracket 110, fixed to a transmission case 22 together with a valve body 31 by a bolt V1 at a left-hand side of assembling direction toward the valve body 31, and a protrusion 125 protruded in a right-hand side of the assembling direction. A second solenoid valve S2 has a second bracket 210, fixed to the valve body 31 by a bolt V2 in the left-hand side of the assembling direction toward the valve body 31, and a retainer 215 capable of abutting with the protrusion 125 of the first solenoid valve S1 at the left-hand side of the assembling direction.

Heating of metallic rods induced by time-varying gradient fields in MRI.

Abstract: Purpose To develop and validate an analytical technique to estimate the heating of metallic rods by magnetic resonance imaging (MRI) gradient fields to aid developers of MRI-compatible devices. Materials and Methods Twelve rods (12.7 mm diameter, 127 mm long) were used. The magnetic field was provided by a custom-made water-cooled solenoid driven by a 1 kHz sinusoidal waveform with a 7.2 A peak current. The sample was insulated with polystyrene and the temperature measured using an MR-compatible thermocouple system (Sa1-E from Omega). Measurements were recorded using a National Instruments SCXI-1303. The AC/DC module of COMSOL 3.4 was used for finite element analysis of the power deposited. Results Finite element analysis (FEA) showed good correspondence with the analytical estimates for the rod parallel to the field and then FEA was used to determine the scaling function for the rod perpendicular to the field. The experimental results showed good correlation with the theoretical estimate when the finite length of the test coil was accounted for. Conclusion A new scaling function for the rod perpendicular to the field was developed. Heating in this orientation is double that of the parallel case. The results will aid developers of MRI-compatible devices in estimating heating before testing in the MRI. J. Magn. Reson. Imaging 2013;38:411–416. © 2013 Wiley Periodicals, Inc.

Magnetic force on a magnetic particle within a high gradient magnetic separator

Abstract: HGMS (High Gradient Magnetic Separator) uses matrix to make high magnetic field gradient so that ferro- or para-magnetic particles can be attracted to them by high magnetic force. The magnetic force generated by the field gradient is several thousand times larger than that by background magnetic field alone. So the HGMS shows excellent performance compared with other magnetic separators. These matrixes are usually composed of stainless steel wires having high magnetization characteristics. This paper deals with superconducting HGMS which is aimed for purifying waste water by using stainless steel matrix. Background magnetic field up to 6 T is generated by a superconducting solenoid and the stainless steel matrixes are arranged inside of the solenoid. Based on magnetic field calculated by FEM (Finite Element Method), we could calculate magnetic force acting on a magnetic particle such as hematite and maghemite consisting of major impurities in the condenser water of a thermal power station.

An omnidirectional electromagnet for remote manipulation

Abstract: An Omnimagnet is an omnidirectional electromagnet comprised of a ferromagnetic core inside of three orthogonal nested solenoids. It generates a magnetic dipole-field with both a variable dipole-moment magnitude and orientation with no moving parts. The design of an Omnimagnet, in which each solenoid has the same dipole moment and minimizes the differences between each of the solenoid's fields, is provided and optimized for strength by tailoring the size of the spherical core used to amplify the solenoids' field. This design is then analyzed using FEA tools and shown to be dipole-like in nature. Various magnetic control methods are then motivated by providing the necessary equations relating the three applied currents to applied field, torque, or force on an adjacent magnetic device. Finally, the optimal design is constructed and its utility is demonstrated by driving a helical capsule endoscope mockup through a transparent lumen.

Phenomenological modeling and measurement of proportional solenoid with stroke-dependent magnetic hysteresis characteristics

Abstract: In this paper, a phenomenological model of stroke-dependent magnetic characteristics of proportional solenoids is proposed. The Discrete Dynamic Preisach hysteresis model is extended so as to map a bivariate hysteresis of the flux linkage depending on both, the coil current and anchor stroke. Moreover an elaborated and hardware implemented method for measuring the magnetic characteristics using the primary excitation coil only is addressed. Is is shown how the model can be identified by a set of quasi-static magnetic measurements. The dynamic measurement with time-varying current and stroke is used to evaluate the model-based flux linkage prediction.