from a cryogenic buffer-gas beam source into the moving traps of a 4.5-m-long traveling-
wave Stark decelerator. The SrF molecules in X 2 Σ+(v= 0, N= 1) state are brought to rest as
the velocity of the moving traps is gradually reduced from 190 m/s to zero. The molecules
are held for up to 50 ms in multiple electric traps of the decelerator. The trapped packets
have a volume (FWHM) of 1 mm 3 and a velocity spread of 5 (1) m/s, which corresponds to a …