Absolute <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e262" altimg="si68.svg"><mml:msup><mml:mrow /><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math>He polarimetry for a double-chambered cell using transmission of thermal neutrons

We present an absolute $^3$He polarimetry method based on thermal neutron transmission for a double-chambered cell. This utilizes the fact that nucleus has large absorption cross section and spin dependence neutrons. The cell had pumping chamber target chamber. Polarized gas was produced in by SEOP then diffused into polarization determined comparing transmissions with polarized unpolarized targets. measurement performed at RIKEN Accelerator-Driven Compact Neutron Source. statistical error of 1.8% systematic uncertainty 0.6%. can be used to obtain high-precision data observables few-nucleon scattering investigation nuclear forces.