Critical current density and third-harmonic voltage in superconducting films

Mawatari, Yasunori; Yamasaki, H.; Nakagawa, Yoshihiko

doi:10.1063/1.1510159

Cited by 95 publications

(89 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When the current amplitude exceeds the value at which the maximum induced sheet-current density reaches K c = j c d, a third-harmonic voltage appears in the coil. 26,27,28,29 A similar technique was introduced by Hochmuth and Lorenz. 30 The effects discussed in this paper and applied to type-II superconducting films are quite general and also should be observed in type-I superconductors.…”

Section: Summary and Discussionmentioning

confidence: 99%

Flux domes in weak-pinning superconducting films without edges

Clem

Mawatari

2006

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

Domelike magnetic-flux-density distributions previously have been observed experimentally and analyzed theoretically in superconducting films with edges, such as in strips and thin plates. Such flux domes have been explained as arising from a combination of strong geometric barriers and weak bulk pinning. In this paper we predict that, even in films with bulk pinning, flux domes also occur when vortices and antivortices are produced far from the film edges underneath current-carrying wires, coils, or permanent magnets placed above the film. Vortex-antivortex pairs penetrating through the film are generated when the magnetic field parallel to the surface exceeds Hc1 + Kc, where Hc1 is the lower critical field and Kc = jcd is the critical sheet-current density (the product of the bulk critical current density jc and the film thickness d). The vortices and antivortices move in opposite directions to locations where they join others to create separated vortex and antivortex flux domes. We consider a simple arrangement of a pair of current-carrying wires carrying current I0 in opposite directions and calculate the magnetic-field and current-density distributions as a function of I0 both in the bulk-pinning-free case (Kc = 0) and in the presence of bulk pinning, characterized by a field-independent critical sheet-current density (Kc > 0).

show abstract

Section: Summary and Discussionmentioning

confidence: 99%

Flux domes in weak-pinning superconducting films without edges

Clem

Mawatari

2006

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…5. After applying the voltage criterion [5] (I 0 = I T ⇐⇒ V 3 = 0.1 mV) to the curves, we get I T = 47.6 mA and 24.2 mA for y c = 0 mm and 9 mm, respectively. By substituting the values of F m and I T into (8), we obtain j * C = 0.988 MA/cm 2 and 0.503 MA/cm 2 for y c = 0 mm and 9 mm, respectively.…”

Section: Numerical Simulation Of Inductive Methodsmentioning

confidence: 99%

“…In addition, F m is a factor determined only by the configuration of a coil and a film [5]. Equation (8) indicates that the critical current density can be estimated from the measured value of the threshold current I T .…”

Section: Inductive Methods and Mawatari's Theorymentioning

confidence: 99%

“…The inductive method [4,5] has been widely used as a contactless method for measuring j C in a HTS thin film. In the method, an ac current I(t) is applied in a coil and, simultaneously, the third-harmonic voltage V 3 sin(6π f t + θ 3 ) induced in the coil is monitored.…”

Section: Inductive Methods and Mawatari's Theorymentioning

confidence: 99%

“…The purpose of the present study is to develop a highperformance method for analyzing the time evolution of the shielding current density in a HTS thin film and to numerically investigate the inductive method [4,5] by means of the high-performance method.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

High Performance Analysis of Shielding Current Density in High Temperature Superconducting Thin Film

Kamitani

Takayama

Nakamura

2010

Plasma and Fusion Research

View full text Add to dashboard Cite

A high-performance method has been proposed for calculating the shielding current density in a hightemperature superconducting thin film. After spatially discretized, the initial-boundary-value problem of the shielding current density is reduced to a system of first-order ordinary differential equations that has a strong nonlinearity. However, the system cannot be always solved by means of the Runge-Kutta method even when an adaptive step-size control algorithm is incorporated to the method. In order to suppress an overflow in the algorithm, the following method is proposed: the J-E constitutive relation is modified so that its solution may satisfy the original constitutive relation. A numerical code for analyzing the shielding current density has been developed on the basis of the proposed method and the inductive method has been investigated by use of the code.

show abstract