“…If the twist pitch is ≥Lc, the filaments would be magnetically coupled, and stability and AC loss would be similar to the ones of a single, very large filament. • Flux jumps in tapes: most of the magnets build in 60's and 70' with Nb3Sn tapes reached only 20% to 50% of the field expected from short sample Jc, the reason was flux jump instabilities [11].…”