The 40Ca(alpha,gamma)44Ti Reaction Using DRAGON


In our every day life we are surrounded by materials composed of the elements of the periodic table. Rarely does one ask where these elements came from. It has been a long process of discovery to understand the precise origin of many of the elements we consider commonplace. It is now believed that the Big-Bang produced only the lightest elements, primarily hydrogen and helium, and that heavier elements were synthesized as the product of nuclear reactions within stars. Occasionally the nuclear reactions that occur within stars produce an isotope of an element which is unstable, radioactive. When a radioactive species decays it emits radiation which is characteristic of the species that decayed. Satellites have been able to detect the characteristic radiation from the decay of several isotopes in the Milky Way. One in particular which has been detected is the isotope of titanium, 44Ti. The decay of 44Ti has been seen in the ashes of exploding stars, vast gas clouds termed supernova remnants. This isotope of titanium eventually decays to a stable isotope of calcium found everywhere on Earth from bones to chalk. It is believed that the bulk of the production in stars of 44Ti occurs as the star explodes, during the supernova. Calculations indicate that among the many possible reactions during a supernova, a particular nuclear reaction, where calcium captures a helium nucleus and fuses into titanium, is the main source of 44Ti. In this work it is detailed how using laboratory equipment on Earth one is able to shed light on the nuclear physics of this particular reaction governing the production of an isotope in our universe.

Author: Christian Ouellet