| Abstract | The design of solenoids with inside radii of 4 or more cm and capable of producing alternating fields of a few thousand oersted is given. It is shown that, to produce such high fields, large wire sizes
are required, the ohmic resistance being the main determining factor of the field attainable. A multi-layer solenoid (5. 7 cm core radius) designed to produce fields of 3,800 oersted peak on an input of 230 volts is described. Practical
considerations such as field uniformity, core sizes, heating problems, high voltages and methods of preventing anhysteretic remanent magnetization are discussed. The circuit, the semi-automatic operation and other details of an apparatus onsisting
principally of a solenoid, a tumbler and an induction coil are given. Severa! workers have extensively used the apparatus for rock magnetism studies. |