Instantaneous heat dissipation from magnetization losses during ramping of magnets

Coils where current is carried by type-II superconducting filaments are studied, with emphasis on instantaneous heat dissipation. A way to compute these heat losses as a function of time and location for certain magnet systems under certain restrictions is suggested. A numerical method to compute the two-dimensional current distribution and electric field in non-penetrated filaments is described. It is shown how the proposed program can be used to calculate heat losses in a typical coil configuration. Given a transport current through the coil, one first computes the induced field in a cross-section of the coil by that current. The induced field is perpendicular to the current carrying filaments. Next, one studies short pieces of filament, assuming that they are part of an infinitely long filament, and computes heat loss per unit length. From the current distributions and electric field one can obtain heat losses.<
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