In this work, we present new data on the ${}^{182,183,184}\mathrm{W}(\gamma ,n$) cross sections, utilizing a quasi-monochromatic photon beam produced at the NewSUBARU synchrotron radiation facility. Further, we have extracted the nuclear level density and $\gamma$-ray strength function of ${}^{186}\mathrm{W}$ from data on the ${}^{186}\mathrm{W}(\alpha ,{\alpha }^{\prime }\gamma ){}^{186}\mathrm{W}$ reaction measured at the Oslo Cyclotron Laboratory. Combining previous measurements on the ${}^{186}\mathrm{W}(\gamma ,n$) cross section with our new ${}^{182,183,184}\mathrm{W}(\gamma ,n$) and ($\alpha ,{\alpha }^{\prime }\gamma ){}^{186}\mathrm{W}$ data sets, we have deduced the ${}^{186}\mathrm{W}\gamma$-ray strength function in the range of $1<E_{\gamma }<6$ MeV and $7<E_{\gamma }<14$ MeV. Our data are used to extract the level density and $\gamma$-ray strength functions needed as input to the nuclear-reaction code talys, providing an indirect, experimental constraint for the ${}^{185}\mathrm{W}(n,\gamma ){}^{186}\mathrm{W}$ cross section and reaction rate. Compared to the recommended Maxwellian-averaged cross section (MACS) in the KADoNiS-1.0 database, our results are on average lower for the relevant energy range $k_{B}T\in [5,100]$ keV, and we provide a smaller uncertainty for the MACS. The theoretical values of Bao et al. [At. Data Nucl. Data Tables 76, 70 (2000)] and the cross section experimentally constrained on photoneutron data of Sonnabend et al. [Astrophys. J. 583, 506 (2003)] are significantly higher than our result. The lower value by Mohr et al. [Phys. Rev. C 69, 032801(R) (2004)] is in very good agreement with our deduced MACS. Our new results provide an improved uncertainty estimate for the ($n,\gamma ){}^{186}\mathrm{W}$ reaction rate, which is one important ingredient in simulations for investigating the neutron density and the ${}^{186,187}\mathrm{Os}$ production in the $s$ process.

• Received 31 January 2023
• Accepted 28 June 2023

DOI:https://doi.org/10.1103/PhysRevC.108.025804