High magnetic fields are useful to study many magnetic phenomena in solids and for the magnetization of permanent magnets. For a comprehensive survey of the applications of high magnetic fields in solid state physics the visitor can look for specialized books devoted to this subject. The term ‘high magnetic fields’ accounts for the generation of maximum magnetic field values well above to those produced by resistive electromagnets. A resistive electromagnet is in fact the most common way to produce static magnetic fields of moderate intensity.

Commercial electromagnets commonly produce maximum static magnetic fields in the air gap between poles in the range 10-20 kOe, although the state-of-the-art electromagnets found nowadays in the market are able to create 25-30 kOe. As in any other system the maximum field obtained depends on the maximum possible current. The maximum current that can circulate through the coils is limited by the insulating of the cooper wire used. In order to increase the maximum current without damaging of the insulating copper wire the coils are water or air cooled.
From theThe systems developed to produce ‘high static magnetic fields’, such as superconducting solenoids, cryogen-free magnets, Bitter magnets or hybrid magnets, are complex and quite expensive. They can not be considered as conventional techniques. By using these systems maximum magnetic fields in the range 50-300 kOe can be obtained.

From the practical point of view, the less expensive way to obtain magnetic fields in the range 100-400 kOe is by means of pulsed magnets. These systems are based on the discharge, over a few turns cooper mechanically reinforced solenoid, of the energy stored in a battery of condensers. In the bore of the few-turns solenoid, or pulsed magnet, a pulsed magnetic field is generated. Fig. 1 show the typical shape of pulsed current, or the magnetic field, as a function of time.
		Fig. 1 Shape of the pulsed current, or the magnetic field, as a function of time in a pulsed field solenoid.

		Fig. 2 shows the electric circuit of a pulsed field system or magnetizer. A DC power supply serves as charging unit, generating a selectable charging voltage that energizes a capacitor bank. The stored energy is given by E = CV2/2; where C is the total capacity and V the charging voltage. Using an appropriate high current electronic switch the energy stored in the battery of condensers is discharged on the magnetizing coil. The latter must be mechanically reinforced in order to avoid its destruction due to the huge forces of magnetic origin between the windings.
Fig. 2. Electric circuit of a pulsed field system.

Along the axial direction the interaction is attractive in character while along the radial direction is repulsive. Fig. 3 shows a cut view and a photograph of a few turns pulsed field solenoidal magnet. Fig. 4 shows a typical dependence on the charge voltage, Vc, of the magnetic field (Hp) and current (Ip) peak values (total capacity of the capacitor bank C = 2400 microFarads). For generating a ?eld of the order of 20 T (pulse duration of 1.5 ms), Vc = 2.8 kiloVolts).
		Fig. 4 Typical dependence on the charge voltage

Fig. 3 (a) Cut view of a few turns pulsed field solenoidal magnet.	Fig. 3 (b) Reinforced pulsed field coil.