The relationship of levitation force between individual discs and double-layer disc YBa_2Cu_3O_(7-x) superconductors

摘要

Two well-textured single-domain YBa_2Cu_3O_(7-x) (YBCO) thin disc samples (phi 30 X 7 mm), SI_1 and SI_2, were used to investigate the relationship of levitation force between individual YBCO discs and a double-layer disc sample, SD (formed by putting samples SI_1 and SI_2 coaxially together). The levitation forces for samples SI_1 and SI_2 are 18.1 and 17.8 N, respectively. The levitation force of the sample SD is 31.2 N, slightly less than the levitation force summation of the two individual samples; the difference factor is about 15.1 percent. The real difference factor is about 0.64 percent after we take into account the real distance between the magnet and each individual disc. The result is very attractive and useful for practical applications of levitation devices during the design and fabrication.