First results from a next-generation off-plane X-ray diffraction grating. (arXiv:1301.5531v1 [astro-ph.IM])

First results from a next-generation off-plane X-ray diffraction grating. (arXiv:1301.5531v1 [astro-ph.IM]):
Future NASA X-ray spectroscopy missions will require high throughput, high
resolution grating spectrometers. Off-plane reflection gratings are capable of
meeting the performance requirements needed to realize the scientific goals of
these missions. We have identified a novel grating fabrication method that
utilizes common lithographic and microfabrication techniques to produce the
high fidelity groove profile necessary to achieve this performance. Application
of this process has produced an initial pre-master that exhibits a radial
(variable line spacing along the groove dimension), high density (>6000
grooves/mm), laminar profile. This pre-master has been tested for diffraction
efficiency at the BESSY II synchrotron light facility and diffracts up to 55%
of incident light into usable spectral orders. Furthermore, tests of spectral
resolving power show that these gratings are capable of obtaining resolutions
well above 1300 ($\lambda/\Delta\lambda$) with limitations due to the test
apparatus, not the gratings. Obtaining these results has provided confidence
that this fabrication process is capable of producing off-plane reflection
gratings for the next generation of X-ray observatories.