Investigation of the Effect of Phantom Size and Ferromagnetic Core of Ni-Cu Alloy on the Amount of Induction Heating in the Thermotherapy Process Using Comsol Multyphysics® Software

Nickel-Copper ferromagnetic core is used for interstitial local thermotherapy techniques to treat deep-seated tumors such as brain tumors and prostatic tumors. In the present study, the effective parameters on the amount of induction heating in the ferromagnetic core and determining the optimal conditions before performing laboratory processes was investigated by the Comsol Multiphysics 5.4 software. The model consisted of a single Nickel-Copper ferromagnetic core (29.6-70.4 wt %) in the two different size that placed in the central region of a cylindrical water phantom with different radius between 20 mm up to 60 mm. For the study of the thermal distribution due to the electromagnetic induction was used from a finite-element analysis method. The temperature profiles of the ferromagnetic core in the electromagnetic field with a frequency of 75- 350 kHz and the magnetic field of strength (H0) with 200-500 Oe up to 30 minutes showed the possibility of temperature control at the thermo-seed for producing the desired temperature in the thermotherapy process. The decreased phantom radius, as well as increase in the volume of the ferromagnetic core led to a rise in the induction temperature of the core due to the increase in the amount of induced field at the center of the phantom in the constant current and frequency. The results showed that the induced temperature in the core was increased due to the rise of the magnetic field in the fixed frequency or the increase of the frequency in the fixed magnetic field type, which is within most of us interested.