Two of the astrophysically important reactions for X-ray burst models are 24Mg(α, γ)28Si and 59Cu(p, γ)60Zn. However, since these models are sensitive to nuclear reaction rates, it is important to constrain them to reduce possible model uncertainties. Constraining these reaction rates will help to improve the precision of model calculations and our understanding of the behavior of matter in astrophysical environments. We performed 27Al(d, n)28Si neutron evaporation spectrum measurements to constrain the nuclear level density of 28Si and benchmark this method against known levels from the level scheme. We also briefly discuss ongoing work to upgrade our lab with the charged-particle-neutron spectrometer which will enable the simultaneous measurements of neutrons and charged particles.

There is an increasing necessity for low background active materials as ton-scale, rare-event and cryogenic detectors are developed. Poly(ethylene-2,6-naphthalate) (PEN) has been considered for these applications because of its robust structural characteristics, and its scintillation light in the blue wavelength region. Radioluminescent properties of PEN have been measured to aid in the evaluation of this material. In this article we present a measurement of PEN's quenching factor using three different neutron sources; neutrons emitted from spontaneous fission in Cf-252 , neutrons generated from a DD generator, and neutrons emitted from the 13 C(alpha,n) 16 O and the 7 Li(p,n) 7 Be nuclear reactions. The fission source used time-of-flight to determine the neutron energy, and the neutron energy from the nuclear reactions was defined using thin targets and reaction kinematics. The Birks' factor and scintillation efficiency were found to be kB = 0.12 +/- 0.01 mm MeV-1 -1 and S = 1.31 +/- 0.09 MeVeeMeV-1 ee MeV -1 from a simultaneous analysis of the data obtained from the three different sources. With these parameters, it is possible to evaluate PEN as a viable material for large-scale, low background physics experiments.

40K is one of the main isotopes responsible for the radiogenic heating of the mantle in Earth-like exoplanets [1] and hence, plays a very important role in the internal geophysical dynamics of a planet. The abundance of 40K in the mantle and the core of such planets is not always possible to be determined by astrophysical observations, although constraining the nuclear reaction rates of 40K during stellar evolution can also lead to constraining the present amount of 40K in these planets, which will improve our understanding on the habitability potential of Earth-like exoplanets. This study aims to constrain the 40K(n,α)37Cl reaction rate, one of the two major destruction paths of 40K in stellar nucleosynthesis,by measuring the reverse reaction 37Cl(α,n)40K and applying the principle of detailed balance as we have done before for the 40K (40K(n,p)40Ar reaction rate) [2]. During the first set of measurements we performed differential cross-section measurements of the 37Cl(α,n1γ)40K, 37Cl(α,n2γ)40K and 37Cl(α,n3γ)40K reaction channels, for six different center of mass energies in the range between 5.1 and 5.4 MeV. The experiment took place at the Edwards Accelerator Laboratory of Ohio University. The gamma rays from the reaction channels mentioned above were detected by two LaBr3 scintillators. Using the swinger facility to change the angle of the beam-target system with respect to the detection system, we were able to take measurements for the differential cross-section at six different angles between 20° and 120° in the lab system.