These experiments afaik don't require particle accelerators and are a different field of science, one of the largest of these detectors is the LIGO observatory overseen by Caltech
I know. That is why I think the money that would be spent on a new particle accelerator should be spent on new more sensitive gravitational wave detectors.
https://www.ligo.caltech.edu/page/what-is-ligo
There is a list of similar observatories in this document
https://dcc-llo.ligo.org/public/0125/G1600979/003/G1600979_L...