The Cosmic X-ray Telescope Mirror · AI Generator #GEN-479B6A60
Physics · modern-physics
Problem
A space-based X-ray telescope uses a cylindrical nickel mirror to focus X-rays through Bragg reflection. The mirror surface has nickel atoms arranged in a crystal lattice with spacing d=2.03×10−10m. When observing a distant neutron star, the telescope detects X-rays with energy E=8.05keV that undergo first-order Bragg reflection (n=1) at a grazing angle.
To optimize the telescope's sensitivity, engineers need to know the exact reflection angle. However, they also discover that photoelectrons are being ejected from the nickel surface by these same X-rays. The work function of nickel is ϕ=5.15eV.
(a) Find the Bragg angle θ at which the X-rays are reflected from the nickel crystal lattice.
(b) Calculate the de Broglie wavelength of the photoelectrons ejected from the nickel surface.