We develop a series expansion for the calculation of the magnetic field near the center of Helmholtz coils and apply the result to a magnet of our design. Our analysis considers geometric details of the coils, the magnetic properties of the form and windings, conductor insulation effects, and several winding imperfections. We also consider the relaxation of coil symmetry which happens when the mean radius of each coil and the coil midplane separation distance are unequal. We compute the field uniformity near the coil's center for three cases, including one where axial symmetry remains but geometric imperfections of the order of 10(-3) of the coil "radius" exist.

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This paper presents a novel backside de-processing technique for effective failure analysis of advanced multi-level interconnect metallization CMOS ICs with flip chip package.

In order to build high-temperature superconductor (HTS) multichip modules (MCMs), it is necessary to grow several epitaxial layers of YBCO that are separated by thick dielectric layers without seriously affecting the quality of the YBCO layers. In this work, we have successfully fabricated YBCO/YSZ/SiO2/YSZ/YBCO structures on single-crystal LaAlO3 substrates using a combination of pulsed laser deposition for the YBCO layers and ion-beam-assisted rf sputtering to obtain biaxially aligned YSZ intermediate layers. The bottom YBCO layer had a Tc∼89 K, Jc∼7.2×105 A/cm2 at 77 K, whereas the top YBCO layer had a Tc∼86 K, Jc∼6×105 A/cm2 at 77 K. The magnetic field and temperature dependence of Jc for the YBCO films in the multilayer have been obtained. The results for each of the YBCO layers within the YBCO/YSZ/SiO2/YSZ/YBCO structure are quite similar to those for a good quality single-layer YBCO film.

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