Compact, low-power-consuming systems and methods for exposing samples to
high-energy radiation, for example, for exposing samples to x-rays for
implementing x-ray absorption near edge analysis (XANES). The systems and
methods include a low-power-consuming radiation source, such as an x-ray
tube; one or more tunable crystal optics for directing and varying the
energy of the radiation onto a sample under analysis; and a radiation
detecting device, such as an x-ray detector, for detecting radiation
emitted by the sample. The one or more tunable crystal optics may be
doubly-curved crystal optics. The components of the system may be
arranged in a collinear fashion. The disclosed systems and methods are
particularly applicable to XANES analysis, for example, XANES analysis of
the chemical state of chromium or another transition metal in biological
processes.