Spin structure of the neutron ({sup 3}He) and the Bjoerken sum rule

A first measurement of the longitudinal asymmetry of deepinelastic scattering of Polarized electrons from a Polarized {sup 3}He target at energies ranging from 19 to 26 GeV ha, been performed at the Stanford Linear Accelerator Center (SLAC). The spin-Structure function of the neutron g{sub 1}{sup n} has been extracted from the measured asymmetries. The Quark Parton Model (QPM) interpretation of the nucleon spin-structure function is examined in light of the new results. A test of the Ellis-Jaffe sum rule (E-J) on the neutron is performed at high momentum transfer and found to be satisfied. Furthermore, combining the proton results of European Muon Collaboration (EMC) and the neutron results of E-142 the Bjoerken sum rule test is carried at high Q{sup 2} where higher order Perturbative Quantum Chromodynamics (PQCD) corrections and higher-twist corrections are smaller. The sum rule saturated to within one standard deviation.