Astrophysical science metrics for next-generation gravitational-wave detectors

The second generation of gravitational-wave (GW) detectors are being built and tuned all over the world. The detection of signals from binary black holes is beginning to fulfil the promise of GW astronomy. In this work, we examine several possible configurations for third-generation laser interferometers in existing km-scale facilities. We propose a set of astrophysically motivated metrics to evaluate detector performance. We measure the impact of detector design choices against these metrics, providing a quantitative cost-benefit analyses of the resulting scientific payoffs. (paper)