0000000001057081
AUTHOR
O. Kettig
showing 3 related works from this author
Novel digital K-edge imaging system with transition radiation from an 855-MeV electron beam
2001
A novel K-edge imaging method has been developed at the Mainz Microtron MAMI aiming at a very efficient use of the transition radiation (TR) flux generated by the external 855-MeV electron beam in a foil stack. A fan-like quasi-monochromatic hard X-ray beam is produced from the /spl plusmn/1-mrad-wide TR cone with a highly oriented pyrolytic graphite (HOPG) crystal. The absorption of the object in front of a 30 mm/spl times/10 mm pn charge-coupled device (pn-CCD) photon detector is measured at every pixel by a broad-band energy scan around the K-absorption edge. This is accomplished by a synchronous variation of the lateral crystal position and the electron beam direction which defines also…
How narrow is the linewidth of parametric X-ray radiation?
1997
Parametric x-ray or quasi-Cherenkov radiation is produced by the passage of an electron through a crystal. A critical absorber technique has been employed to investigate its linewidth. Experiments have been performed with the 855MeV electron beam from the Mainz Microtron MAMI. Thin absorber foils were mounted in front of a CCD camera serving as a position sensitive photon detector. Upper limits of the linewidth of 1.2 and 3.5eV were determined for the (111) and (022) reflections of silicon at photon energies of 4966 and 8332eV. These limits originate from geometrical line broadening effects that can be optimized to reach the ultimate limit given by the finite length of the wave train. {copy…
Transition radiation in the x-ray region from a low emittance 855 MeV electron beam
1997
A quasi-monochromatic hard x-ray beam with a photon energy of 33 keV has been produced from transition radiation (TR) at the Mainz Microtron MAMI. The radiator was a stack of 30 polyimide foils of 25 μm thickness and 75 μm separation and the monochromator a highly-oriented pyrolytic graphite crystal. The intrinsic bandwidth was measured with a critical absorption technique to be 100 eV. On the basis of these experiments a photon flux of 4⋅109/mm2s over an illuminated area of 5.7×125 mm2 can be expected from an optimized beryllium radiator at a beam current of 100 μA. At the K-absorption edge of titanium at 5 keV narrow band transition radiation has been observed from a stack of four foils o…