Temperature dependence of the AGOR magnetic field

Abstract

It has been found necessary to change the magnet currents gradually during long term operation of the AGOR cyclotron due to temperature changes in the iron, which are caused by the correction coils. These changes influence the magnetisation in various ways: through a change in susceptibility, saturation magnetization, and through a change in metal density. Based on long term measurements of the magnetic field as function of temperature, a thermal model has been made, which is compared with theoretical estimates.</p