Cl Cross Section: Early Solar System Irradiation Effects on Short-Lived Radioisotope Production*

Short-lived radioisotopes (SLRs) with half-lives ~ 100 Ma are known to have existed during the formation of the solar system around 4.5 billion years ago through the detection of their decay products in meteorites. Freshly synthesized  SLRs are believed to have been injected into the Giant Molecular Cloud from which the sun was formed, by a nearby stellar source (e.g. supernovae). The concentration of the decay products of ³⁶Cl exceed their expected enrichment levels, suggesting that a secondary source may be responsible for the excess. Solar energetic particles from the sun may have irradiated gas and dust present in the solar accretion disk, aiding the accumulation of SLRs in chondrules and Ca-Al rich inclusions. Experimental data is needed in order to validate the solar irradiation model, and therefore, the cross sections of the nuclear reactions in question must be measured. The cross section of the ³⁵Cl(³He,2p)³⁶Cl reaction was estimated in order to evaluate the feasibility of creating the reaction in a laboratory setting. Based off of cross section predictions, seven activation energies within the range of  1.44 MeV/A to 2.51 MeV/A are proposed for future measurement.