A method of producing strong magnetic fields

Abstract

There are only two methods of producing a strong magnetic field. The first is by a solenoid, and the second by a solenoid with an iron core in it. The iron is introduced for the purpose of diminishing the magnetic resistance of the magnetic flux, and makes possible the production of much stronger fields than can be obtained without it. This is the principle on which modern electro-magnets are constructed, and by means of them it is possible to obtain field up to 60 kilogauss in a volume of a few cubic millimetres. The saturation of iron, however, makes it impossible to go further than this. According to the present theory of ferro-magnetism we can hardly hope to obtain any ferro-magnetic material which will give a much higher saturation-value than the iron used in modern electro-magnets; and without such a material it is impossible to increase the field obtainable by this means.