  X-ray emission spectroscopy is emerging as an important complement to x-ray
absorption fine structure spectroscopy, providing a characterization of the
occupied electronic density of states local to the species of interest. Here,
we present details of the design and performance of a compact x-ray emission
spectrometer that uses a dispersive refocusing Rowland (DRR) circle geometry to
achieve excellent performance for the 2 - 2.5 keV energy range. The DRR
approach allows high energy resolution even for unfocused x-ray sources. This
property enables high count rates in laboratory studies, comparable to those of
insertion-device beamlines at third-generation synchrotrons, despite use of
only a low-powered, conventional x-ray tube. The spectrometer, whose overall
scale is set by use of a 10-cm diameter Rowland circle and a new small-pixel
CMOS x-ray camera, is easily portable to synchrotron or x-ray free electron
beamlines. Photometrics from measurements at the Advanced Light Source show
somewhat higher overall instrumental efficiency than prior systems based on
less tightly curved analyzer optics. In addition, the compact size of this
instrument lends itself to future multiplexing to gain large factors in net
collection efficiency, or its implementation in controlled gas gloveboxes
either in the lab or in an endstation.
