Dipolar and scalar <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi>He</mml:mi><mml:mprescripts /><mml:none /><mml:mn>3</mml:mn></mml:mmultiscripts><mml:mtext>−</mml:mtext><mml:mmultiscripts><mml:mi>Xe</mml:mi><mml:mprescripts /><mml:none /><mml:mn>129</mml:mn></mml:mmultiscripts></mml:mrow></mml:math> frequency shifts in stemless cells

Abstract

We study nuclear spin frequency shifts in a 3He−129Xe comagnetometer caused by spin polarization of 3He. We use stemless cylindrical cells to systematically vary the cell geometry and separately measure the cell shape-dependent and shape-independent frequency shifts. We find that a certain aspect ratio for a cylindrical cell cancels the dipolar effects of 3He magnetization in the regime of fast spin diffusion. Using this control, we observe a scalar 3He−129Xe collisional frequency shift characterized by an enhancement factor κHeXe = −0.011 ± 0.001, which is in excellent agreement with theoretical calculations.