Pulsed loading of a magneto-optical trap on an atom chip with fast recovery of ultrahigh vacuum

Abstract Here, we present studies on pulsed loading of a rubidium (Rb) magneto-optical trap (MOT) in an ultra-high vacuum (UHV) environment on an atom chip. We have used a parallel combination of Rb dispensers for better heat dissipation to achieve fast UHV recovery in the chamber after the end of the current pulse to the dispensers. We have estimated the threshold heat energy required for activation of the dispensers for different values of current pulses. Although a pulse with a higher current value and shorter duration has a lower threshold heat energy, we operated the dispensers at moderate current pulse parameters (24 A, 10 s) for protection of the circuits. Nearly, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mn>7</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> cold <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msup> <mml:mrow/> <mml:mrow> <mml:mn>87</mml:mn> </mml:mrow> </mml:msup> <mml:mtext>Rb</mml:mtext> </mml:mrow> </mml:math> atoms were loaded in the MOT using this current pulse, with a UHV recovery time of ∼600 ms in the chamber. This fast recovery of UHV in the MOT chamber is useful for further experiments such as magnetic trapping and evaporative cooling of atoms in the same chamber.