Partner User Proposal Abstract
Incorporation of a High Field Magnet on Beamline 4-ID-C (PUP-8)
We propose to add and commission a high-field magnet experimental endstation on APS beamline 4-ID-C, and to develop instrumentation for a series of photon-in-photon-out experimental techniques to be used with high field. This station will incorporate a 7 Tesla ultrahigh vacuum superconducting magnet, a variable-temperature sample insert, sample preparation facilities, and a series of detectors to allow a wide range of soft x-ray absorption, fluorescence spectroscopy, and scattering techniques. Soft x-ray probes are very powerful techniques that offer simultaneous structural, chemical, and magnetic information. X-ray absorption spectroscopy gives element specific electronic structure, x-ray resonant scattering adds site selectivity and roughness information, and x-ray induced optical luminescence provides additional information on valence and conduction band structure. When circularly polarized x-rays are used as the excitation source, all of these techniques can probe magnetic structure as well using dichroism effects that occur on resonance. These techniques have been very successful in studying a wide variety of technologically important magnetic materials. However, soft x-rays have very short scattering lengths at ambient pressure, and thus require an ultrahigh vacuum sample environment, making the application of magnetic fields above 0.2 Tesla very difficult. The addition of high-field x-ray techniques to 4-ID-C will enhance the soft x-ray capabilities at the APS to be on par with those of other synchrotron facilities and will allow the study of several new classes of magnetic materials that currently cannot be effectively probed with the current end stations.
