Collaborative Research: Stray Light Control for Cosmic Explorer

Gravitational-wave astronomy has now opened a new window to the universe, which along with conventional telescopes, significantly broadens our understanding of astrophysics and cosmology. Cosmic Explorer is a concept for a next-generation gravitational-wave observatory in the United States, enabling the detection of nearly every black-hole collision in the observable universe. To achieve the unprecedented sensitivity of this observatory, significant R&D effort needs to be invested in designs that will minimize various sources of noise. This award addresses a major noise source, namely stray light, and will produce a conceptual design for its mitigation. Specifically, this award enables a team of scientists and engineers to analyze how stray light in the interferometer’s 40km arm cavities may limit Cosmic Explorer's sensitivity and produce an initial conceptual design for the beamtube baffles. Mitigating stray light in the beamtubes is a high-priority research topic, as it directly impacts the facility design and cost. In addition, the project will produce requirements for surface roughness of the mirrors used as test masses in the interferometer and explore low-scatter vacuum-compatible materials. This award is one of a series of NSF awards that together will produce conceptual designs and technologies to enable the realization of Cosmic Explorer. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.