Table 2.

Annihilation detector efficiencies and background rates

	Efficiency	Uncertainty	Background rate (10−3 s−1)	Uncertainty (10−3 s−1)
Laser exposure (300 s)	0.472	0.001	1.04	0.11
Microwave exposure (32 s)	0.801	0.002	33.0	0.6
Release of surviving atoms (1.6 s)	0.852	0.002	191	1

The detection efficiencies and background rates of the silicon vertex detector, as determined by the multivariate analysis (Methods), are listed for the three observation windows. The 1.6-s window during which the surviving atoms are released extends for 0.1 s after the magnet rampdown is complete.