The Feasibility of direct measurement of the 44Ti(α, p)47V and 40Ca(α, p)43Sc reactions in forward kinematics at astrophysically relevant temperatures

Understanding the synthesis of radioactive 44Ti in the α-rich freeze-out following core-collapse supernovae may help to better interpret such explosive events. The γ-ray lines from the decay of 44Ti have been observed by space-based γ-ray telescopes from two supernova remnants. It is believed that the 44Ti(α,p)47V reaction dominates the destruction of 44Ti, while the 40Ca(α,p)43Sc reaction removes fuel from the main 44Ti production reaction 40Ca(α,γ)44Ti. Here we report on a possible technique to determine both reaction rates at astrophysically relevant energies in forward kinematics. The first reaction will be performed using a 1–10 MBq 44Ti target. Two important concerns are considered to make this study possible: The amount of stable Ti in the radioactive target, which will be prepared via spallation reactions at Paul Scherrer Institute (PSI), and the degree of radioactive contaminations in the experimental setup due to sputtered 44Ti atoms after intensive irradiations. Several online and offline measurements in parallel with Monte Carlo simulations were performed to investigate these issues.