Short-lived radionuclides ( SLRs ) with lifetimes \tau < 100 Ma are known to have been extant when the Solar System formed over 4.5 billion years ago .
Identifying the sources of SLRs is important for understanding the timescales of Solar System formation and processes that occurred early in its history .
Extinct ^ { 36 } Cl ( t _ { 1 / 2 } = 0.301 Ma ) is thought to have been produced by interaction of solar energetic particles ( SEPs ) , emitted by the young Sun , with gas and dust in the nascent Solar System .
However , models that calculate SLR production in the early Solar System ( ESS ) lack experimental data for the ^ { 36 } Cl production reactions .
We present here the first measurement of the cross section of one of the main ^ { 36 } Cl production reactions , ^ { 33 } S ( \alpha , p ) ^ { 36 } Cl , in the energy range 0.70 - 2.42 MeV/A .
The cross section measurement was performed by bombarding a target and collecting the recoiled ^ { 36 } Cl atoms produced in the reaction , chemically processing the samples , and measuring the ^ { 36 } Cl/Cl ratio of the activated samples with accelerator mass spectrometry ( AMS ) .
The experimental results were found to be systematically higher than the cross sections used in previous local irradiation models and other Hauser-Feshbach calculated predictions .
However , the effects of the experimentally measured cross sections on the modeled production of ^ { 36 } Cl in the early Solar System were found to be minimal .
Reactions channels involving S targets dominate ^ { 36 } Cl production , but the astrophysical event parameters can dramatically change each reactions ’ relative contribution .