The uniform magnetic field coil can be placed in the shielding room (MSR) to provide a more accurate source. could generate by conventional design method, but when MSR, uniformity of would affected. analysis model based on cuboid ferromagnetic boundary condition is constructed image method. This paper proposes new method parameters deviation distribution volumes boundary. system shield designed compared with system, which not only solves problem reducing, also further improves field....

Sensing vector magnetic fields is important to many applications in fundamental physics, bioimaging, and materials science. Sensors exploiting nitrogen-vacancy (N-$V$) centers typically interrogate N-$V$ ensembles oriented all directions, thwarting nanoscale spatial resolution. Utilizing the level anticrossing triplet ground state, authors demonstrate a...

During the last decades, development of increasingly sensitive magnetic sensors led to numerous applications field measurements in neuro-science, medical diagnostics, brain-computer interfaces, metrology or for experiments testing fundamental laws nature. Especially small, lightweight, rather mobile and easy handle optically pumped magnetometers allows more advanced dynamic studies of, e.g., brain. The limitation quality such signals are gradients drifts measuring environment. This article...

In this article, a uniform magnetic field coil with shield is presented and designed to cancel the geomagnetic surrounding noises. First, an analytical model of developed, based on Biot–Savart law traditional images method. Second, in order improve accuracy, influence noninfinite thickness produced by considered using multireflection theory, improved obtained. The verified three-dimensional finite-element method, its accuracy significantly compared previous analysis model. Then,...

We report the design and performance of a nonmagnetic drift stable optically pumped cesium magnetometer with measured sensitivity 35 fT at 200 s integration time stability below 50 between 70 600 s. The sensor is based on nonlinear magneto-optical rotation effect: in Bell–Bloom configuration, higher order polarization moment (alignment) Cs atoms created pump laser beam an anti-relaxation coated Pyrex cell under vacuum, filled vapor room temperature. plane light passing through modulated due...

Ultra-low magnetic fields have drawn lots of attention due to their important role in scientific and technological research. The combination a shield an active compensation coil is adopted most high performance magnetically shielded rooms. Special consideration needs be taken the design since significantly affects uniformity field that generated by coil. An analytical model for calculation inside cubic proposed based on generalized image method, which validated finite element analysis. A...

The minimization of the remanent magnetization ferromagnetic materials is a prerequisite for reproducible low magnetic field inside shields. To realistically describe this so-called equilibration procedure, paper proposes two approaches calculation time- and space-dependent fields in presence like permalloy. first method based on Jiles-Atherton model also takes into account frequency dependent effects. second newly developed empirical phase shift model, tailored specially simulation...

To enable the realization of weak magnetic field at level several nanotesla, a magnetically shielded room (MSR) is required to create space with residual below 1 nT. Since by inner shielding shells very low, permeability materials in this range measured. As gaps between ferromagnetic material strips wall lead considerable reduction factor, new numerical model evaluate equivalent discontinuous layers proposed and demonstrated experimentally. Based on property lower normal range, improved...

This article proposes a novel hybrid rotor permanent magnet (HRPM) machine for the performance of torque and overload capability with constraint diameter. In order to optimize electromagnetic performance, an analytical model (AM) is built by magnetic equivalent circuit (MEC) stator considering saturation leakage flux effect. A good prediction accuracy verified finite element method (FEM), even in high condition. Based on AM, characteristics pole are analyzed strategy that PM remanence...

The homogeneity of the magnetic field generated by a coil inside shield is essential for many applications, such as ultra-low nuclear resonance or spin precession experiments. In course upgrading Berlin Magnetically Shielded Room (BMSR-2) with new inserted Permalloy layer side length 2.87 m, we designed built-in consisting four identical square windings attached to its walls. spacings were optimized using recently developed semi-analytic model and finite element analysis. result reveals...

Magnetic shielding made from permalloy is frequently used to provide a time-stable magnetic field environment. A low and gradients inside the shield can be obtained by using demagnetization coils through walls, encircling edges of shield. We first introduce test computational models calculate properties large size shields with thin walls. then vary size, location shape openings for at corners cubic It turns out that effect on factor expected influence residual homogeneity in vicinity center...

To enable the realization of ultra-low magnetic fields for scientific and technological research, shielding is required to create a space with low residual field high factors. The factors shields are due nonlinear material properties, geometry structure shields, external fields. Magnetic used in environments full random realistic disturbances, resulting an arbitrary field, this case, effect hard define simply by A new method simulate predict dynamic internal wave proposed based on Finite...

This paper presents an analytical method for predicting the electromagnetic performance in permanent magnet (PM) machine with spoke-type rotor (STR) and a proposed hybrid structure (HRS), respectively. The key of this is to combine magnetic field analysis model (MFAM) equivalent circuit model. influence irregular PM shape considered by segmentation calculation. To obtain boundary condition MFAM, respectively, two methods on side are proposed. In STR, average flux density core outer-surface...

One new approach for detection tank level is investigated based on the auto-adaptive double-threshold Canny operator, considering IR imaging of and aiming at problem level. Edge operator can set automatically, according to different gray gradient histogram's feature, instead traditional in which should be artificially, avoid loss edge information especially liquid level's because improper artificial selection. In process picking up information, it analyze number horizontal stripes, get their...

In this paper, a feasibility analysis of modular uniform magnetic field coil is provided. The consists n2 square units. By adjusting the number units or current in units, different sizes and patterns coils can be easily formed to meet experimental requirements. An analytical model considering gap between first developed based on Biot–Savart law superposition principle, verified by 3D finite element method. Then, characteristics are analyzed compared with traditional Helmholtz coil,...

Electric actuators with fast dynamic response and high torque density are widely used in aerospace industrial applications. In this paper, the design optimization of a short-term high-overload permanent magnet synchronous motor (STHO-PMSM) is presented. The rated working point optimized according to operating conditions motor. effect electromagnetic load on extreme which mainly include ampoule number magnetic energy PM researched. Due nonlinear saturation influence, equivalent network model...

Accurately calculating the magnetic acceleration noise is essential to designing space inertial sensor and constructing its evaluation system. In view of shortcomings calculation model, which considers test mass (TM) as an ideal dipole rather than entity, Maxwell stress tensor method (MSTM) virtual work principle (VWPM), consider influence shape size TM into account are adopted in this study. Through comparison, it concluded that non-uniformities internal field magnetization intensity...

The magnetic field inside a spherical shield with infinite permeability and circular aperture in homogeneous of arbitrary direction is analytically derived. closed-form formulas for the static shielding factors are theoretical upper limits real shields. We discuss gradient caused by single aperture, implying that using symmetric pairs more favorable. Based on results ideal shields, an approximate solution to calculate factor shields finite and/or multiple apertures developed. calculations...

The existing flow analysis in air gap of high speed motor commonly neglects Tooth-slots effects. influence whirlpools induced by the slots and teeth on field heat transfer is investigated this paper. According to theory fluid mechanics, solved region boundary conditions are assigned. Two kinds distributions considering notches domain or not presented. Then normal temperature coupled calculation model ignoring movements notch established calculated. And new which included calculated solved....

There are two kinds of high temperature superconducting motor (HTS) according to the angle superconductor's shape, one with bulk and other tapes. Using tapes, HTS motors, whose magnets located in rotor, have been researched by many researchers institutes. This paper research a novel structure that coils placed slots stator made ferromagnetic materials. researches magnetic field distribution coil teeth stator. The electromagnetic under influence rotating material is presented firstly. Then,...

The magnetic acceleration noise (MAN) that stems from the eddy current dissipation of a test mass (TM) serves as an important source for space inertial sensors. Given problem (ECDMAN) cubic TM defies analytical solutions, model ECDMAN spherical TM, which has same volume is systematically derived on basis principles electromagnetism and fluctuation-dissipation theorem, this can be used approximate evaluation term. Based model, with LISA Pathfinder (LPF) research object, paper obtains...

Magnetic shields are specified by the shielding factor (SF) determined with an external ac magnetic field that is uniform in absence of shield. External excitation coils (EECs) close to shield widely used as source. An analytic solution for SF measured EEC presented case a spherical shield, which common approximation shields. At sphere center, independent dimensions and its value equal known result excitation. The behavior two configurations, single coil symmetrical pair, compared respect...