Analytical alignment tolerances for off-plane reflection grating spectroscopy

Off-plane grating mount tolerances for Constellation-X

High groove density reflection gratings placed at grazing incidence in the extreme off-plane mount offer increased performance over conventional in-plane mounts in the x-ray. We are developing an off-plane approach to the Reflection Grating Spectrometer of the Constellation-X Mission. In this paper we discuss the geometry of the off-plane mount and present formulae for the key tolerances of the...

Grating-coupler assisted infrared reflection absorption spectroscopy for the characterization of organic thin films.

We demonstrate how grating-coupler assisted infrared reflection absorption spectroscopy can be used to simultaneously determine the chemical identity and relative thickness of organic thin films. With a grating substrate, a threshold anomaly associated with passing off of the -1 diffracted order occurs at grazing angles of incidence, resulting in a sharp absorbance in the infrared. The position...

Investigating Ultrasonic Diffraction Grating Spectroscopy and Reflection Techniques for Characterizing Slurry Properties

XMM-Newton Reflection Grating Spectrometer

We present the first high resolution X-ray spectrum of the bright O4Ief supergiant star ζ Puppis, obtained with the Reflection Grating Spectrometer on-board XMM-Newton. The spectrum exhibits bright emission lines of hydrogen-like and helium-like ions of nitrogen, oxygen, neon, magnesium, and silicon, as well as neon-like ions of iron. The lines are all significantly resolved, with characteristi...

Analytical Dynamic Modelling of Heel-off and Toe-off Motions for a 2D Humanoid Robot

The main objective of this article is to optimize the walking pattern of a 2D humanoid robot with heel-off and toe-off motions in order to minimize the energy consumption and maximize the stability margin. To this end, at first, a gait planning method is introduced based on the ankle and hip joint position trajectories. Then, using these trajectories and the inverse kinematics, the position tra...