Channeling radiation from thick crystals and at high electron-bunch charges

For possible applications channeling of electrons has been investigated with respect to the maximum achievable channeling-radiaton intensity per crystal thickness and also for high electron-bunch charges. Using diamond crystals of various thickness up to 204 μm and electron energies of 9 and 10 MeV the photon intensity of the 1–0 transition of the (110) plane was found to be (1.12 ± 0.17) 10−1 photons/e/sr at 9 MeV and (1.56 ± 0.25) 10−1 photons/e/sr 10 MeV. The maximum intensity is expected at these electron energies for a thickness between 500 and 800 μm, respectively. In a further experiment that is currently under development at the A0 TESLA Test Facility at Fermilab the upper intensity limit for the production of channeling radiation by relativistic electrons of typically 16 MeV energy interacting with thin (∼ 18 μm) diamond and Si crystals is investigated. It is the aim to explore channeling under extreme conditions and thus to use channeling as a test bench to study the basics of channeling-plasma acceleration. For electron charge densities up to 8 nC/bunch, which is nearly six orders of magnitude larger than employed so far, resulting in a photon flux of 2 · 1010 photons/sr pulse at a photon energy between 15 and 25 keV no evidence has been found of significant quenching of channeling.