Thin-Wall Bulk High Temperature Superconductor as a Permanent Cryomagnet
Résumé
Thin-wall single domains with artificial patterned holes are highly interesting for stimulating superconducting and mechanical properties of bulk YBCO materials. YBCO single domains were successfully grown from multiple holes preforms by using TSIG or TSMG techniques. The thin-wall configuration enables a remarkable improvement in flux trapping and superconducting properties whatever the used growth process. Progressive oxygenation under high pressure associated to the large specific areas was shown to boost the material performances. A trapped field maximum of 0.84 T was recorded at 0.2 mm above the top surface of a 16 mm thin wall pellet at 77 K. Such complex geometry can be easily and abundantly produced by using an extrusion process. We report for the first time to our knowledge the growth of a single domain from an extruded preform. Thin-wall samples were then impregnated by resign/alloy for mechanical reinforcement.
Mots clés
Extrusion
Flux trapping
High-pressure oxygenation
High temperature superconductors
Thin-wall single grain
Superconducting magnets
Yttrium barium copper oxide
Preforms
Resins
Barium compounds
Copper compounds
Cryogenics
High-temperature superconductors
Mechanical properties
Permanent magnets
Yttrium compounds