Study on Magnetic Flux Dissipation and Field-Trapping Performance of HTS Bulk-Shaped Magnesium Diboride in Pulse-Field Magnetizing Processes

Oka, Tetsuo; Oki, Hayami; Ogawa, J.; Fukui, Satoshi; Scheiter, J.; Häßler, Wolfgang; Yokoyama, K.; Yamanaka, K.; Dadiel, Longji; Muralidhar, M.; Sakai, Naomichi; Murakami, Masato; Noudem, Jacques

doi:10.1109/tasc.2019.2908752

Cited by 7 publications

(4 citation statements)

References 19 publications

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“…The areas enclosed in blue rectangles in figure 6 (5) and ( 6) demonstrate this process. Very similar responses to magnetic pulses with flux jumps upon demagnetization were observed in papers [15,30,32,34].…”

Section: Discussionsupporting

confidence: 76%

“…Numerous studies of bulk superconductors and stacks of HTS-tapes [1,15,18,24,[26][27][28][29][30][31][32][33][34][35][36][37] are dedicated to the socalled flux jumps (or 'giant field leaps' as first introduced in [27]). These jumps occur at certain critical (or activation) fields and result in a rapid invasion of the magnetic flux into the superconducting samples.…”

Section: Introductionmentioning

confidence: 99%

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Thermal behavior of ﬂux jumps and inﬂuence of pulse-shape on the trapped ﬁeld during pulsed magnetization of a high-temperature superconductor

Moroz¹,

Kashurnikov²,

Rudnev³

et al. 2021

J. Phys.: Condens. Matter

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The impact of temperature on the pulsed magnetization of a high-temperature superconductor (HTS) has been numerically studied. The resulting trapped field (TF) and its distribution over the HTS have been calculated for samples with random and periodic pinning (a regular triangular lattice). The increasing ambient temperature (within the considered values) has been shown to improve the field-trapping efficiency and lead to the possibility of pumping more flux into the sample with each consecutive pulse (contrary to the low-temperature case). Various pulse shapes produced different results at high temperatures. Trapezoidal pulses showed the highest efficiency owing to the constant-field segments during which the vortices continued to enter the sample. The critical (activation) field of flux jumps has been shown to decrease with the rising temperature. At the highest considered temperature (30 K), the flux jumps occurred during the TF relaxation. To the best of our knowledge, such calculations have been done for the first time.

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Section: Discussionsupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Thermal behavior of ﬂux jumps and inﬂuence of pulse-shape on the trapped ﬁeld during pulsed magnetization of a high-temperature superconductor

Moroz¹,

Kashurnikov²,

Rudnev³

et al. 2021

J. Phys.: Condens. Matter

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“…In the existing literature, studies optimising the final trapped field in MgB 2 bulk samples have focussed on exploring bulk properties [22,23] or the use of split-coil magnetic field geometries [24]. The effect of interfacial cooling has not been explicitly explored despite numerical studies indicating its significance during magnetisation experiments [25].…”

Section: Factors Influencing Final Trapped Fieldmentioning

confidence: 99%

Improved pulsed field magnetisation in MgB₂ trapped-field magnets

Moseley

Matthews

Zhou

et al. 2021

Supercond. Sci. Technol.

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Bulk superconductors can act as trapped-field magnets with the potential to be used for many applications such as portable medical magnet systems and rotating machines. Maximising the trapped field, particularly for practical magnetisation techniques such as pulsed field magnetisation (PFM), still remains a challenge. PFM is a dynamic process in which the magnetic field is driven into a superconducting bulk over milliseconds. This flux motion causes heating and a complex interplay between the magnetic and thermal properties. In this work, the local flux density during PFM in a MgB 2 bulk superconductor has been studied. We find that improving the cooling architecture increases the flux trapping capabilities and alters the flux motion during PFM. These improvements lead to the largest trapped field (0.95T) for a single MgB 2 bulk sample magnetised by a solenoidal pulsed field magnet. The findings illustrate the fundamental role bulk cooling plays during PFM.

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“…An intermetallic superconductor MgB 2 [1] with strongly linked grains [2,3] enables the fabrication of practicable untextured samples with a high critical current density, J c , over 10 5 -10 6 Acm −2 below 20 K in the self-field [4][5][6][7]. A polycrystalline MgB 2 bulk acts as a quasi-permanent magnet that sustains a Tesla-class magnetic field via various magnetizing processes under static [8][9][10][11][12][13][14][15][16][17][18][19] and pulsed [20][21][22][23] magnetic fields. The record-high trapped field, B T , of 5.4 T among MgB 2 bulk magnets was realized by field-cooled magnetization (FCM) at 12 K for the MgB 2 disk bulk (20 mm in diameter and 8 mm in thickness, ϕ20 mm × t8 mm), which was fabricated by an ex-situ hot pressing method using ball-milled nanometersize MgB 2 powder [13].…”

Section: Introductionmentioning

confidence: 99%

A record-high trapped field of 5.6 T in the stacking of MgB₂/TiB₂ composite bulks prepared by an in-situ hot isostatic pressing method

Naito

Takahashi

Awaji

2020

Supercond. Sci. Technol.

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We have studied the trapped field properties of triple and double stacking of M g B 2 / T i B 2 composite superconductor bulks magnetized by field-cooled magnetization. The triple-stacked M g B 2 / T i B 2 bulks trapped a magnetic field of 5.58 T successfully at 11.3 K, which was only 0.18 T but evidently higher than the world record trapped field of 5.4 T among M g B 2 bulk magnets. We also found a potential ability of the present M g B 2 / T i B 2 bulks trapping a 7-T class magnetic field at low temperatures below 4.2 K, although the FCM experiments at both 2.2 and 4.2 K were disturbed by the flux jumps.

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Study on Magnetic Flux Dissipation and Field-Trapping Performance of HTS Bulk-Shaped Magnesium Diboride in Pulse-Field Magnetizing Processes

Cited by 7 publications

References 19 publications

Thermal behavior of ﬂux jumps and inﬂuence of pulse-shape on the trapped ﬁeld during pulsed magnetization of a high-temperature superconductor

Thermal behavior of ﬂux jumps and inﬂuence of pulse-shape on the trapped ﬁeld during pulsed magnetization of a high-temperature superconductor

Improved pulsed field magnetisation in MgB₂ trapped-field magnets

A record-high trapped field of 5.6 T in the stacking of MgB₂/TiB₂ composite bulks prepared by an in-situ hot isostatic pressing method

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Study on Magnetic Flux Dissipation and Field-Trapping Performance of HTS Bulk-Shaped Magnesium Diboride in Pulse-Field Magnetizing Processes

Cited by 7 publications

References 19 publications

Thermal behavior of ﬂux jumps and inﬂuence of pulse-shape on the trapped ﬁeld during pulsed magnetization of a high-temperature superconductor

Thermal behavior of ﬂux jumps and inﬂuence of pulse-shape on the trapped ﬁeld during pulsed magnetization of a high-temperature superconductor

Improved pulsed field magnetisation in MgB2 trapped-field magnets

A record-high trapped field of 5.6 T in the stacking of MgB2/TiB2 composite bulks prepared by an in-situ hot isostatic pressing method

Contact Info

Product

Resources

About

Improved pulsed field magnetisation in MgB₂ trapped-field magnets

A record-high trapped field of 5.6 T in the stacking of MgB₂/TiB₂ composite bulks prepared by an in-situ hot isostatic pressing method