Production and deceleration of a pulsed beam of metastable NH (a1Δ) radicals

Abstract

We report on the production of a pulsed molecular beam of metastable NH (a1Δ) radicals and present first results on the Stark deceleration of the NH (a1Δ, J = 2, MΩ = −4) radicals from 550 m s−1 to 330 m s−1. The decelerated molecules are excited on the spin-forbidden A3Π ← a1Δ transition, and detected via their subsequent spontaneous fluorescence to the X3Σ−, v = 0 ground state. These experiments demonstrate the feasibility of our recently proposed scheme (2001 Phys. Rev. A 64 041401) to accumulate ground-state NH radicals in a magnetic trap. In addition, we propose to transfer the NH radicals from the a1Δ state to the X3Σ− state using a cw-laser to allow cooling of the beam during trap loading.