An ultrahigh vacuum apparatus for H atom scattering from surfaces

Abstract

We present an apparatus to study inelastic H or D atom scattering from surfaces under ultra-high vacuum conditions. The apparatus provides high resolution information on scattering energy and angular distributions by combining a photolysis-based atom source with Rydberg atom tagging time-of-flight. Using hydrogen halides as precursors, H and D atom beams can be formed with energies from 500 meV up to 7 eV, with an energy spread of down to 2 meV and an intensity of up to 10⁸ atoms per pulse. A six-axis manipulator holds the sample and allows variation of both polar and azimuthal incidence angles. Surface temperature can be varied from 45 K up to 1500 K. The apparatus' energy resolution <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>(</mml:mo> <mml:mrow><mml:mi>E</mml:mi> <mml:mo>/</mml:mo> <mml:mi>Δ</mml:mi> <mml:mi>E</mml:mi></mml:mrow> <mml:mo>)</mml:mo></mml:mrow> </mml:math> can be as high as 1000 and its angular resolution can be adjusted between 0.3° and 3°.