Use of in situ wire in small magnets

A number of small solenoids have been wound from Nb
3
Sn-Cu in situ wire in order to determine the suitability of these compositions for magnet construction. Magnets were wound after the wire was reacted and it was found that bending strains as large as 2% at the outer surfaee of the wire can be used with no degradation of the critical current. Calorimetric measurements of the ac losses indicate full penetration of the magnetic field into the wire above 8 Tesla. In addition it is found that losses are proportional to frequency as would be expected if the losses were hysteretic. Both the core method and an external diffusion method can be used satisfactorily for the fabrication of long lengths of wire.