Adiabatric following and optical pumping effects in the process of slowing atoms with the Zeeman tuning technique

Through studying the declaration process of an atomic beam of sodium using the Zeeman tuning technique1 we verify that for certain laser detunings the atoms do not follow the magnetic field adiabatically. The explanation for this is that at some point the deceleration required is above the maximum allowed value2 of (ħKΓ)/(2M), where K is the laser wave vector, Γ is the natural transition linewidth, and M is the atomic mass.