Proton elastic scattering and neutron distribution of unstable nuclei

We study theoretically how we can determine the neutron density distributio ns of unstable nuclei from proton elastic scattering. We apply the relativi stic impulse model to study the sensitivities of the observables to the den sity distributions which are expressed in Woods-Saxon form. We find that bo th the radius and diffuseness of densities can be determined from restricte d elastic scattering data in principle. We think this result is helpful to design future experiments.