三角形平面载流线圈磁场的空间分布

根据一段载流直导线在空间某点的磁场矢量公式,将多边形载流线圈视为多段载流导线,然后根据场强叠加原理,给出了计算多边形平面载流线圈在空间任意点的磁场分布的方法,并求出了三角形平面载流线圈空间磁场分布的普遍表达式。     

正三角形载流线圈的空间磁场分布

利用一段载流直导线在空间某点的磁场,对正三角形载流线圈进行分段计算,然后根据场强叠加原理,求出正三角形载流线圈的空间磁场分布,并讨论了线圈平面上和中心轴线上的磁场分布情况。     

三角形载流线圈空间磁场的分布

将三角形载流线圈视为三段载流直导线,采取分段计算的办法,导出三角形载流线圈空间磁场分布的普遍表达式,并以正三角形载流线圈为例进行验证。     

任意形状的载流线圈在远处磁场分布的简单计算

文章根据毕－沙定律、电流回路元和载流线圈的费曼模型，用普通物理的方法计算出载流线圈在远处一点的磁场分布。     

用费曼模型求截面为任意形状的无限长载流螺线管的磁场

利用载流线圈的费曼模型，根据截面为圆形的无限长载流螺线管的磁场分布和场叠加原理，求出截面为任意形状的无限长载流螺线管的磁场分布．     

多个矩形载流线圈组合磁场的模拟仿真及应用

根据毕奥-萨伐尔定律推导出矩形载流线圈在空间产生磁场的计算公式.利用公式计算出两个\\四个矩形载流线圈同名磁极相对时磁场分布规律.根据计算结果,设计出磁场能量转化演示仪,分析了弹体在磁场中运动特点及动能的来源.     

磁场对载流线圈的作用

讨论了磁场对于载流线圈的合作用力、合力矩、磁力作功公式和载流线圈在外磁场中的相互作用能，以及带电粒子在一对励磁线圈之间的往复运动。     

科学可视化技术在物理教学中的应用

通过求解平面载流线圈在基所在平面上磁场分布，介绍了科学可视化技术在物理教学中的应用。     

关于磁场的两个张量

本文通过非均匀磁场对载流线圈的作用的研究，引入了关于磁场的两个张量，这就是磁力 张量 T和磁力矩张量g，利用L和g计算非均匀磁场对载流线圈的作用，十分方便。     

任意四边形载流线圈的空间磁场计算

从教材中一个常见例题的结论出发,首先导出了载流直导线磁场的x、y、z分量表达式.然后,利用这一表达式,采取分段计算然后叠加的方法,对任意形状的四边形载流线圈的磁场进行了计算,并对矩形线圈和方形线圈的特殊情况进行了讨论.     

SHAPING AND ADJUSTING THE FRINGING FIELD OF IRON-FREE COILS BY USE OF SEPARATED COILS

Magnetic field distribution, expressed in terms of coil parameters (geometric and current), of various kind of ironfree current wire elements is derived. A method for shaping and adjusting fringing field profile by the use of separated current wires which have different coil parameters is suggested, and the optimization of coil parameters is realized by the use of the method of least square. As an example, magnetic field profile of an iron-free magnetic β-ray spectrometer is shaped and adjusted to illustrate the use of this method.     

安培分子电流假说思想的应用

本文介绍了安培分子电流思想在磁力对载流线圈做功方面的应用和对斯托克斯公式的几何解释。     

Differentiating the shape of stellarator coils with respect to the plasma boundary

The task of designing the geometry of a set of current-carrying coils that produce the magnetic field required to confine a given plasma equilibrium in stellarators is expressed as a minimization principle, namely that the coils minimize a suitably defined error expressed as a surface integral, which is recognized as the quadratic-flux. A penalty on the coil length is included to avoid pathological solutions. A simple expression for how the quadratic-flux and coil length vary as the coil geometry varies is derived, and an expression describing how this varies with variations in the surface geometry is derived. These expressions allow efficient coil-design algorithms to be implemented, and also enable efficient algorithms for varying the shape of the plasma surface in order to simplify the coil geometry, and a numerical illustration of this is given.     

Relativity and gravity

A logical sequence of ideas in electromagnetism can be based on the behaviour of a current-carrying coil as a magnetic dipole of moment μiA, where μ is the permeability of the medium in which the coil is situated, i the current and A the effective area (area × number of turns) of the coil (Chalmers 1965). The occurrence of μ rather than μ_o is verified from the effect of permeability on self-inductance.     

Guiding neutral atoms on a chip

We demonstrate the guiding of neutral atoms by the magnetic fields due to microfabricated current-carrying wires on a chip. Atoms are guided along a magnetic field minimum parallel to and above the current-carrying wires. Two guide configurations are demonstrated: one using two wires with an external magnetic field, and a second using four wires without an external field. These guide geometries can be extended to integrated atom optics circuits, including beam splitters.     

Magnetic guide of cold atoms using a U-shaped current-carrying conductor

We propose a new scheme to magnetically guide cold neutral atoms using a U-shaped current carrying conductor. The spatial magnetic field distribution from the U-shaped current-carrying conductor and the relationship between the magnetic field and parameters of the U-shaped conductor are analysed. Our study shows that U-shaped current-carrying conductor can be used to realize single- or double-channel magnetic guiding of cold atoms in weak-field-seeking states and to construct various atom-optical elements. By using Monte Carlo simulations, the dynamic process of the guided atomic-beam splitting in an atomic-beam splitter composed by the U-shaped current-carrying conductor is studied, and some results are presented.     

EAST极向场线圈及磁测量系统的修正

采用网格法计算空间磁场,应用最小二乘法优化极向场线圈、单匝环、磁探针位置参数及标定系数获得了更准确的位置坐标,明显地改善了磁场和磁通的计算误差,也为等离子体平衡反演算法提供更准确的格林函数。     

Magnetic guiding of cold neutral atoms using a V-shaped current-carrying conductor

A new scheme to magnetically guide cold, neutral atoms using a V-shaped current-carrying conductor is proposed. The spatial distributions of the magnetic fields, potentials and forces generated by the V-shaped current-carrying conductor are calculated, and the relationship between the magnetic field and the parameters of the V-shaped current-carrying conductor are analyzed in detail. Our study shows that the V-shaped current-carrying conductor proposed here can be used to guide cold atoms in the weak-field-seeking state, and to construct various atom-optical elements, such as atomic funnel, atomic beam-splitter and atom interferometer and so on, and even to realize a single-mode atomic waveguiding under certain conditions. Received 17 November 2000 and Received in final form 26 May 2001     

Guiding Neutral Atoms with Two Current-Carrying Wires and a Vertical Bias Field on the Atom Chip

We demonstrate the guiding of neutral atoms with two parallel microfabricated current-carrying wires on the atom chip and a vertical magnetic bias field. The atoms are guided along a magnetic field minimum parallel to the current-carrying wires and confined in the other two directions. We describe in detail how the precooled atoms are efficiently loaded into the two-wire guide. We present a detailed experimental study of the motional properties of the atoms in the guide and the relationship between the location of the guide and the vertical bias field. This two-wire guide with vertical bias field can be used to realize large area atom interferometer.     

The correspondence between a current-carrying coil and a magnetic dipole

The difficulties associated with the correspondence between the electric vectors E and D and the magnetic vectors B and H, when a current-carrying coil is considered as a magnetic dipole, are eliminated if it is considered, not as a simple dipole, but as a ‘dipotential’ or dipole with a constant potential difference.