Cr/Sc multilayer radiator for parametric EUV radiation in “water-window” spectral range

Diffracted diffraction radiation and its application to beam diagnostics

“…PXR and DTR can be produced not only by crystals, where the lattice parameter limits the wavelength range of the generated radiation to < 2 , but also by artificial periodic structures with an arbitrary lattice parameter, which are often called multi-layered X-ray mirrors [24,25]. Increasing the lattice parameter up to several tens of nanometers will increase to several millimeters and allow us to measure linear collider electron beam parameters in the particle energy region of 20-500 GeV.…”

“…See, for example, Ref. [25], where the authors have confidently observed PXR and especially DTR with energy of several hundred electron volts from a Cr/Sc multilayer radiator. Moreover, DDR in such X-ray mirrors could be used for diagnostics of electron beams from XFEL linear accelerators with particle energies of 10-20 GeV.…”

“…The most optimal way is using a Cr/Sc multilayer radiator with the lattice parameter = 2.34 nm turned on the angle Θ = 45 • as in the experiment [25]. Similar mirrors with 250 layers provide a reflection coefficient about 10%, [27] and angular size of the reflection spot Δ = Δ ∕ ⋅ (Θ ) ≈ 4 mrad.…”

“…Possible imperfections in the X-ray mirror structure must also be taken into account (see, e.g., Ref. [25]). The last item is especially important for comparing experimental and calculation results.…”

Generation of X-rays by electrons recycling through thin internal targets of cyclic accelerators

“…The multilayer structures must be fabricated on the thinnest substrates because the substrates decrease the number of passes through the structures. But, the experiment in [14] showed that there was a problem connected with the quality of structures created on very thin substrates. A study of radiation generated by 5.7 MeV electrons of the extracted microtron beam in a structure consisting of 100 Cr/Sc bi-layers with a period of 2.34 nm deposited onto a 500 nm Si 3 N 4 substrate showed that radiation yield was 10 times lower than that calculated theoretically.…”