Directly measuring the 65 keV resonance strength of the $^{17}O(p, \gamma)^{18}F$ reaction at LUNA.

The $^{17}O (p, \gamma)^{18}F$ reaction plays a crucial role in AGB nucleosynthesis as well as in explosive hydrogen burning occurring in type-Ia novae. At the temperatures of interest for the former scenario ($20 MK < T< 80$ MK) the main contribution to the astrophysical reaction rate comes from the poorly constrained $E_R = 6$ keV resonance. The strength of this resonance is presently determined only through indirect measurements. A new high-sensitivity setup was installed at LUNA, located at LNGS, where the cosmic-ray background is reduced by several orders of magnitude. The residual background was further reduced installing a devoted shielding. Furthermore the $4\pi$ BGO detector was coupled with Al target chamber and holder to increase efficiency. With more than 400C accumulated on $Ta_2{O}_5$ targets the LUNA Collaboration has performed the first direct measurement of the 65 keV resonance strength. In this communication the improved experimental setup will be described, the analysis procedure will be discussed and preliminary results will be shown.