The Spin Structure of the Neutron and 3HE:. AN Overview of the Jlab Experiments in Hall a

I shall discuss three experiments which form part of a comprehensive physics program aimed at the study of the spin structure of the neutron using a polarized ³He target and a polarized beam at JLab in Hall A. Results from the first experiment performed to evaluate the Gerasimov-Drell-Hearn (GDH) extended sum rule are presented and future approved measurements are discussed. The main goal of these experiments is to bridge our understanding of the strong interaction in the large Q² regime where quarks and gluons are the relevant degrees of freedom to the low Q² regime where constituent quarks and mesons seem to be more adequate for a description of the nucleon properties.