A Tunable, High Power Interferometer Beam with Reduced Pointing Fluctuations and Wavefront Aberrations for 100-Meter Baseline Atom Interferometry (MAGIS-100)

MAGIS-100 is a 100 meter baseline atom interferometer which will search for wavelike dark matter, serve as a prototype gravitational wave detector in the 0.3-3 Hz frequency range, and realize large scale quantum superpositions. The interferometer will be assembled in the vertical MINOS access shaft at Fermilab and will split the wave function of an atom cloud via the strontium clock resonance. The space-time area enclosed by the interferometer arms can be increased with large momentum transfer pulse sequences, but jitter in the pointing of the interferometer beam and aberrations in the wavefront of the laser limits the ultimate sensitivity. We present the design and prototype test of a beam delivery system for MAGIS-100 informed by numerical simulations addressing the impact of laser wavefront aberrations on the atom cloud interference pattern, as well as a plan for measuring laser wavefront aberrations with the atoms on site.