Results for “wigglers and undulators)”

NASA NTRS1985

Study of the potential usefulness of superfine holographic x-ray gratings in AXAF and astrophysics in general

Present day high energy electron storage rings and insertion devices (wigglers and undulators) provide the necessary technology to manufacture superfile (line density or=100,00/mm) holographic X-ray gratings. The usefulness in future astrophysical research of such gratings is determined, as a function of the grating size and line density. A model design is given for an instrument which would fit within the (presently specified) constraints of the planned Advanced X-ray Astrophysics Facility (AXAF).

Csonka, P. L.↗

NASA NTRS1989

Trace element abundance determinations by Synchrotron X Ray Fluorescence (SXRF) on returned comet nucleus mineral grains

Trace element analyses were performed on bulk cosmic dust particles by Proton Induced X Ray Emission (PIXE) and Synchrotron X Ray Fluorescence (SXRF). When present at or near chondritic abundances the trace elements K, Ti, Cr, Mn, Cu, Zn, Ga, Ge, Se, and Br are presently detectable by SXRF in particles of 20 micron diameter. Improvements to the SXRF analysis facility at the National Synchrotron Light Source presently underway should increase the range of detectable elements and permit the analysis of smaller samples. In addition the Advanced Photon Source will be commissioned at Argonne National Laboratory in 1995. This 7 to 8 GeV positron storage ring, specifically designed for high-energy undulator and wiggler insertion devices, will be an ideal source for an x ray microprobe with one micron spatial resolution and better than 100 ppb elemental sensitivity for most elements. Thus trace element analysis of individual micron-sized grains should be possible by the time of the comet nucleus sample return mission.

Flynn, G. J.↗