The $\gamma$-ray strength function and the nuclear level density of $^{ 167}$Ho have been extracted using the Oslo method from a $^{ 164}\text{ Dy}(\alpha,p\gamma)^{ 167}$Ho experiment carried out at the Oslo Cyclotron Laboratory. The level density displays a shape that is compatible with %can be approximated with the constant temperature model in the quasicontinuum, while the strength function shows structures indicating the presence of both a scissors and a pygmy dipole resonance. Using our present results as well as data from a previous $^{ 163}\text{ Dy}(\alpha,p\gamma)^{ 166}$Ho experiment, the $^{ 165}\text{ Ho}(n,\gamma)$ and $^{ 166}\text{ Ho}(n,\gamma)$ MACS uncertainties have been constrained. The possible influence of the low-lying, long-lived 6~keV isomer $^{ 166}$Ho in the $s$ process is investigated in the context of a 2~$M_\odot$, [Fe/H]=-0.5 AGB star. We show that the newly obtained $^{ 165}\text{ Ho}(n,\gamma)$ MACS affects the final $^{ 165}$Ho abundance, while the $^{ 166}\text{ Ho}(n,\gamma)$ MACS only impacts the enrichment of $^{ 166,167}$Er to a limited degree due to the relatively rapid $\beta$ decay of the thermalized $^{ 166}$Ho at typical $s$-process temperatures.
Categories: nucl-ex