The Paleomagnetics Research Laboratory (PRL) of the University of Houston comprises a two-component cryogenic magnetometer housed in a three layered magnetically shielded room constructed with high permeability silicon steel. Ambient magnetic fields within the shielded room are less than 200nT. The magnetometer has a large dynamic range (1.0 x 10-8 to 5.0 Gauss cm3) making it suitable for the measurement of the magnetization of a wide range of materials.
In addition to the magnetometer, there is a thermal demagnetization unit suitable for heating batches of samples between room temperature and 800 C: samples are cooled in a low field region (<1 nT) to prevent the acquisition of spurious magnetizations. There is also an alternating field magnetization unit (non-tumbling) which generates unidirectional demagnetizing fields between 0 and 100 nT for the study of coercivity spectra of the remnant magnetization of materials.
The magnetometer is interfaced with a microcomputer to facilitate the recording of data on floppy disc for later processing and analysis.
A second magnetically shielded room (two-layer mu-metal; ambient fields <200 nT) is currently used to store samples, and houses a MOLSPIN flux-gate spinner magnetometer which has a sensitivity of better than 1 x 10-7 emu/cc at 24 seconds and has an integration time of between 6 seconds (24 spins) or 24 seconds (120 spins). Investigators at the PRL also have access to a Franz Isodynamic Separator, which is capable of isolating magnetic grains from host rock material, and an electromagnet that can be used to study the isothermal remanence characteristics of paleomagnetic samples. This magnet is capable of producing uniform fields of 8 kOe over a volume suitable for typical paleomagnetic core samples and can be used to determine the saturation remanence of many magnetic minerals.
