Among the many production and destruction nuclear reactions that bear on the net44Ti yield in the supernova environment, recently highlighted by γ-ray astronomy observations, the α capture on40Ca stands out in the α-rich freezeout phase conjectured by astrophysical models. We activate a He-gas target, with a40Ca beam and implant recoiling44Ti nuclei (∼106) in a Cu catcher. The44Ti atoms chemically extracted with anatTi carrier are counted by accelerator mass spectrometry (AMS). The measurement of the44Ti/Ti ratio, together with the amount, of Ti carrier added, determine the number of44Ti nuclei produced in the activation, independent, of chemical yield or transmission efficiency. The resonance strength (7.4±2.5 eV) at Ecm∼1.1 MeV/n determined for two close-by levels of44Ti is in excellent agreement, with previous prompt-γ measurements. We plan to extend our experiments to the lower energy range.
|Original language||English (US)|
|Number of pages||4|
|Journal||Nuclear Physics A|
|State||Published - Jul 28 2003|