Mössbauer Techniques Using High-Field Water-Cooled Solenoids
It has been clear for some time that external magnetic fields are frequently of considerable use in various aspects of Mössbauer spectroscopy. Such fields are, among other things, useful for producing hyperfine splitting in magnetically disordered systems, for simplifying hyperfine structure by providing a magnetic axis of symmetry, for finding the sign of the hyperfine field relative to some externally observable parameter, and for studying certain features of the magnetic properties of matter. In general, for Mössbauer experiments, field uniformity is not a prime consideration; however, most experiments have required fairly large volumes (approx. 1 in.3) within which the field is uniform to within 1% and available for durations as long as several days. Very low fields (less than 2 kOe) in practically any size volume may be obtained with permanent magnets. Iron core magnets can easily produce 10 to 20 kOe in suitable volumes. Where fields of about 20 kOe or less will suffice (such as to magnetize an iron foil in a direction parallel to the plane of the foil), permanent and iron core magnets are readily available and their use poses no unusual technological problems. Still higher fields, which are frequently required, may be obtained using superconducting solenoids which are capable of producing up to 100 kOe in useful volumes . While superconducting magnets may soon produce fields as high as 150 kOe using present technology, practical considerations rule out the probability of using such magnets for Mössbauer experiments in the immediate future.
KeywordsVelocity Signal Pickup Coil Mossbauer Spectrum Cold Finger Triangular Wave
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