Pulsed field magnetization of melt-processed Sm–Ba–Cu–O

Ishihara, Hiromasa; Ikuta, Hiroshi; Itoh, Yoshitaka; Yanagi, Yousuke; Yoshikawa, Masaaki; Oka, Tetsuo; Mizutani, Uichiro

doi:10.1016/s0921-4534(01)00383-5

Cited by 18 publications

(13 citation statements)

References 6 publications

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“…It was demonstrated that, by the IMRA method, the YBaCuO bulk could trap almost the same amount of the magnetic flux as the FCM method in liquid nitrogen [7]. At temperatures lower than 77 K, however, the maximum value of B T and T by PFM including the IMRA method is generally lower than that by FCM as reported for the SmBaCuO bulk superconductors with the stronger pinning force F p [8,9]. A possible reason may be a large temperature rise caused by the magnetization hysteresis loss and by the viscous loss due to the magnetic flux motion in a short pulse field period, which results in the decrease of B T .…”

Section: Introductionmentioning

confidence: 97%

Generated heat during pulse field magnetizing for REBaCuO (RE = Gd, Sm, Y) bulk superconductors with different pinning abilities

Fujishiro

Kaneyama

Yokoyama³

et al. 2004

Supercond. Sci. Technol.

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Pulse field magnetizing (PFM) using five successive magnetic pulses (Nos 1-5) with the same amplitude from 3.01 to 5.42 T has been performed for three types of cryo-cooled REBaCuO bulk superconductor discs (RE = Gd, Sm, Y) with an identical size. The time evolution and spatial distribution of temperature T (t), the total trapped magnetic flux P T and the trapped magnetic field B P T have been measured after applying the magnetic pulse. The total magnetic flux FC T trapped by the field cooled magnetizing (FCM) is the largest for the Gd bulk and is the smallest for the Y bulk. The time and position dependences of T (t) during PFM show a characteristic behaviour depending on the species of bulks which results from the difference in the strength of the pinning force F p. The generated heat Q(No i) after the No i pulse has been estimated based on the maximum temperature rise T max and the specific heat C. The Q = Q(No 1)-Q(No 5) value, which is mainly contributed by the pinning power loss (Q p) for pulse No 1, is the smallest for the Y bulk, and the Q(No 5) value, which is mainly contributed by the viscous flow loss (Q v), is the smallest for the Gd bulk. These results suggest that the heat generation by PFM is closely related to the strength of F p of the bulk crystal.

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Section: Introductionmentioning

confidence: 97%

Generated heat during pulse field magnetizing for REBaCuO (RE = Gd, Sm, Y) bulk superconductors with different pinning abilities

Fujishiro

Kaneyama

Yokoyama³

et al. 2004

Supercond. Sci. Technol.

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“…Our group has therefore studied the PFM process by employing two local probe methods based on small Hall sensors and pickup coils [12][13][14][15]. In particular, the small Hall sensor method has elucidated that the penetration of the flux lines into the sample is anisotropic [14; 15].…”

Section: Introductionmentioning

confidence: 99%

Local measurements of the magnetization process of bulk superconductors induced by a pulsed magnetic field

Ikuta

Tokuyama

Yanagi³

2008

J. Phys.: Conf. Ser.

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“…It is widely accepted that the magnetic fluxes penetrate into the bulk crystal preferentially through the weaker pinning regions of the superconductors [4]. The 4-fold GSBs may act as efficient pinning centres for the magnetic fluxes.…”

Section: Position Dependence Of Temperature Risementioning

confidence: 99%

“…It was demonstrated that, by the IMRA method, the YBaCuO bulk could trap almost an equal amount of the magnetic flux as the FCM method in liquid nitrogen [3]. However, at temperatures lower than 77 K, the maximum trapped magnetic flux by PFM even using the IMRA method is generally lower than that by FCM as shown for the SmBaCuO bulk superconductors [4,5]. A possible origin for this observation can be the temperature rise caused by the viscous motion of the magnetic fluxes, resulting in the decrease of the trapped field.…”

Section: Introductionmentioning

confidence: 99%

Time evolution and spatial distribution of temperature in YBCO bulk superconductor after pulse field magnetizing

Fujishiro

Oka²,

Yokoyama³

et al. 2003

Supercond. Sci. Technol.

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The time evolutions of temperature rise T (t) after pulse field magnetizing have been measured on the surface of a cryo-cooled YBaCuO bulk superconductor. The temperature rise T increases with increasing pulse field strength, and a quite large temperature rise (T max ∼ 18.8 K) is observed just before the trapped magnetic flux reaches the central region of the bulk. The epoxy resin, impregnated and coated to the bulk crystal for mechanical reinforcement, prevents the heat exhaust towards the cold stage of the refrigerator and it needs much time to recover its initial temperature. The spatial distribution of T (t) has indicated that the magnetic fluxes tend to enter into the bulk, avoiding the 4-fold growth sector boundaries of the bulk crystal.

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Pulsed field magnetization of melt-processed Sm–Ba–Cu–O

Cited by 18 publications

References 6 publications

Generated heat during pulse field magnetizing for REBaCuO (RE = Gd, Sm, Y) bulk superconductors with different pinning abilities

Generated heat during pulse field magnetizing for REBaCuO (RE = Gd, Sm, Y) bulk superconductors with different pinning abilities

Local measurements of the magnetization process of bulk superconductors induced by a pulsed magnetic field

Time evolution and spatial distribution of temperature in YBCO bulk superconductor after pulse field magnetizing

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