IEC 61788-8:2010 Superconductivity - Part 8: AC loss measurements - Total AC loss measurement of round superconducting wires exposed to a transverse alternating magnetic field at liquid helium temperature by a pickup coil method
This part of IEC 61788 specifies the measurement method of total AC losses by the pickup coil
method in composite superconducting wires exposed to a transverse alternating magnetic field.
The losses may contain hysteresis, coupling and eddy current losses. The standard method to
measure only the hysteresis loss in DC or low-sweep-rate magnetic field is specified in
IEC 61788-13 [2].
In metallic and oxide round superconducting wires expected to be mainly used for pulsed coil
and AC coil applications, AC loss is generated by the application of time-varying magnetic field
and/or current. The contribution of the magnetic field to the AC loss is predominant in usual
electromagnetic configurations of the coil applications. For the superconducting wires exposed
to a transverse alternating magnetic field, the present method can be generally used in
measurements of the total AC loss in a wide range of frequency up to the commercial level,
50/60 Hz, at liquid helium temperature. For the superconducting wires with fine filaments, the
AC loss measured with the present method can be divided into the hysteresis loss in the
individual filaments, the coupling loss among the filaments and the eddy current loss in the
normal conducting parts. In cases where the wires do not have a thick outer normal conducting
sheath, the main components are the hysteresis loss and the coupling loss by estimating the
former part as an extrapolated level of the AC loss per cycle to zero frequency in the region of
lower frequency, where the coupling loss per cycle is proportional to the frequency.
IEC 61788-8:2010 history
2010IEC 61788-8:2010 Superconductivity - Part 8: AC loss measurements - Total AC loss measurement of round superconducting wires exposed to a transverse alternating magnetic field at liquid helium temperature by a pickup coil method
2003IEC 61788-8:2003 Superconductivity Part 8: AC loss measurements Total AC loss measurement of Cu/Nb-Ti composite superconducting wires exposed to a transverse alternating magnetic field by a pickup coil method (Edition 1.0)