High Temperature Superconducting Magnetic Levitation

6.5 Levitation forces vs. temperature Ë 163

Fig. 6.12:Photograph of the test device using the G-M refrigerator at 38–77 K in the SCML-01
platform [32].

Fig. 6.13:Photograph of the measurement curve

for levitation forces at 38.4 K [30].

Tab. 6.6:The maximum levitation forces at different temperatures [30].

Levitation forces (N) Temperatures (K)

32.5 38.4

33.5 48.5

32.5 50.0

32.5 54.3

30.6 59.0

29.7 64.5

29.6 67.6

28.7 70.5

25.8 75.5

21.1 82.0

9.6 88.0

0 93.0

0 100.0

On the basis of the above studies, Wang et al. [31] further studied the relationship
between the levitation force and the temperature. A single YBCO bulk (휙 30 ×17 mm)
was fixed on the second stage cooling head of the G-M refrigerator, rather than being
immerged in liquid nitrogen (77 K), whose temperature can be controlled by the