Dependences of slowing results on both decelerator parameters and the new operating mode: Taking ND₃ molecules as an example

We experimentally test our homemade electrostatic Stark decelerator with 99 slowing stages with a supersonic ND₃ molecular beam. Relationships between the performance of the decelerator and various parameters, including the kinetic energy loss per stage versus the synchronous phase angle φ₀, the final central velocity of a slowed molecular packet versus both the phase angle φ₀ and the decelerating stage number and the relative slowing efficiency versus the phase angle φ₀, are studied both theoretically and experimentally. With our homemade Stark decelerator, a supersonic ND₃ beam is successfully decelerated from 330 to 24 m s^-1, producing a molecular packet with a translational temperature of ∼36 mK. Experimental results are in good agreement with their simulated and theoretically calculated counterparts. In addition, we propose and study a new mode to operate a Stark decelerator that allows one to prepare a slow, number-density-enhanced, high-energy-resolution molecular beam, which is essentially a complementary mode to the scheme proposed by Parazzoli et al (2009 New J. Phys. 11 055031) in a low velocity regime and promises important applications in the research of cold collisions and cold chemistry.