The Curie-point technique involves placing a thin ferromagnetic wire in an induction coil connected to a high frequency power supply (Figure 14). When the h.f. field is switched on, the ferromagnetic wire inductively heats to its Curie-point temperature, at which the wire loses its ferromagneticity and becomes paramagnetic. This causes a drastic loss in energy absorption from the h.f. field in the coil. Provided that the wire dimensions and h.f. field parameters are properly matched, the equilibrium temperature (T ) of the wire stabilizes close to the Curie-point temperature, at a point where the residual energy absorption by Eddy currents ("skin glass reaction tube sample

0 0

Post a comment