TY - JOUR

T1 - Fast determination of 2D current patterns in flat conductors from measurement in their magnetic field.

AU - Wijngaarden, R.J.

AU - Heeck, K.

AU - Spoelder, H.J.W.

AU - Surdeanu, R.C.

AU - Griessen, R.P.

PY - 1998/2/1

Y1 - 1998/2/1

N2 - An extremely fast method is presented to calculate the local current–density vector in a flat conductor from the z-component of the magnetic field measured above its surface, e.g. by means of magneto-optical indicators, Hall-probe arrays or scanning SQUIDs. The method may be used for samples of arbitrary thickness provided that the current vector has only x- and y-components. The method combines the conjugate gradient (CG) method and fast Fourier transform to invert the relevant Toeplitz matrix equation. For a current map of n×n pixels, the number of operations needed is of order n2.8 only, compared to n4.5 or higher for earlier methods. The increase in speed for 512×512 pixels is found to be a factor 135 with respect to the fastest existing CG method.

AB - An extremely fast method is presented to calculate the local current–density vector in a flat conductor from the z-component of the magnetic field measured above its surface, e.g. by means of magneto-optical indicators, Hall-probe arrays or scanning SQUIDs. The method may be used for samples of arbitrary thickness provided that the current vector has only x- and y-components. The method combines the conjugate gradient (CG) method and fast Fourier transform to invert the relevant Toeplitz matrix equation. For a current map of n×n pixels, the number of operations needed is of order n2.8 only, compared to n4.5 or higher for earlier methods. The increase in speed for 512×512 pixels is found to be a factor 135 with respect to the fastest existing CG method.

U2 - 10.1016/S0921-4534(97)01799-1

DO - 10.1016/S0921-4534(97)01799-1

M3 - Article

VL - 295

SP - 177

EP - 185

JO - Physica C. Superconductivity and its Applications

JF - Physica C. Superconductivity and its Applications

SN - 0921-4534

IS - 3-4

ER -