Commissioning and first measurements at the CASPAR underground accelerator facility

The Compact Accelerator System for Performing Astrophysical Research (CASPAR) is the only U.S. deep underground accelerator facility, with a low-background environment created by 4300 m.w.e of overhead rock shielding, suitable for low-energy nuclear astrophysics measurements. Utilizing an electrostatic acceleration system covering the energy range 150 keV to 1.1 MeV for both ¹H⁺ and ⁴He⁺ beams, crucial reactions of interest in stellar burning are accessible in the Gamow energy range. Commissioning measurements of the CNO-cycle reaction ¹⁴N(p,γ)¹⁵O are now complete, with results presented here. CASPAR now begins to focus on reactions of interest for the production of heavy elements through the s-process, primarily the neutron source reactions for both the main and weak s-process, ¹³C(α,n) and ²²Ne(α,n) respectively.