$\mathbf{\vec{n}}$-d Analyzing Power at $\mathbf{E_{n} = 21.0}$ and 22.7 MeV

The $\vec{n}-d$ analyzing power $A_{y}(\theta)$ was measured for $E_{n} = 21.0$ MeV and $E_{n} = 22.5$ MeV. Polarized deuterons were accelerated using the TUNL FN-Tandem into a $^{2}$H gas cell to produce the incident polarized neutrons using the $^{2}$H($\vec{d},\vec{n})^{3}$He source reaction. We used a deuterated scintillator as the center detector in our $A_{y}(\theta)$ measurements and a $^{4}$He gas cell to determine the beam polarization. $A_{y}(\theta)$ values were taken at lab angles $39^{\circ}$, $60^{\circ}$, $81^{\circ}$, $94^{\circ}$, $107^{\circ}$, and $128^{\circ}$. This data addresses the long standing discrepancy between rigorous three-nucleon calculations and experimental data (3NAPP) in the unexplored neutron energy range from 19.0 to 30.0 MeV. Our results confirm the 3NAPP. They also show a sensible trend in the maxima and minima between $E_{n} = 19.0$ and 30.0 MeV. This suggests that the theoretical treatment of the three-nucleon systems needs revision. \\ \\ Funded by the NSF (NSF-PHY-05-52723) and the DOE, Office of Nuclear Physics (DE-FG02-97ER41033).