Motional, isotope and quadratic Stark effects in Rydberg–Stark deceleration and electric trapping of H and D

Hydrogen and deuterium Rydberg atoms, initially moving at velocities of 600 m/s and 560 m/s, respectively, in pulsed supersonic beams, have been decelerated and electrostatically trapped following adiabatic 90◦ deflection from their initial axis of propagation to minimise collisions with the trailing edge of the gas pulses. The time evolution of the potential energy surfaces, over which the atoms undergoing deceleration travel during the trap-loading process, is analogous to that of a moving electrodynamic trap and has been studied in the laboratory-fixed frame of reference and in the continuously-moving frame of reference defined by the instantaneous position of the electric-field minimum around which they are located. The importance of the quadratic Stark effect in the deceleration of samples in Rydberg states with principal quantum numbers above 35 has also been investigated by comparison of experimental results with predictions resulting from the numerical calculation of particle trajectories. The data presented for deuterium atoms represent the first application of RydbergStark deceleration and trapping for this atom. Comparison of the rate of loss of n = 30 H and D atoms from the trap enables one to conclude that it is not affected by the particle dynamics during deceleration and trap loading.