Medium Energy (MEP) Group - Polarized 3He Target Experiement
Group Members / Theoretical Background / Experimental Setup / Polarized Target / Reference /
Abstract
In the last twenty years, significant progress has been made into understanding the structure of nucleons in terms of the strong interaction. The development of polarized beam, polarized target and recoil polarimetry technology has provided precision data that has provoked a wide variety of theoretical work.
Nucleon Polarizabilities describe the response of the nucleon within an external electromagnetic field and compromise another set of fundamental quantities related to the nucleon's structure. These polarizabilities can be measured using low-energy Compton scattering. Compton scattering, photons scattering off of matter, is dominated by the nucleons static properties (e.g. mass, anamolous magnetic moment, charge). However, at second-order the electric and magnetic polarizabilities enter into the cross-section. If one goes to third-order, the 4 spin-polarizability parameters appear. The asymmetry in compton-scattering caused by these spin-polarizability parameters has never been measured.
The High Intensity Gamma Source (HIGS) at the Duke Free Electron Laser Laboratory (DFELL) has created an opportunity to measure the spin polarizablities of the neutron using polarized Compton scattering from a polarized nuclear target. This website describes the plans to measure the spin-dependent asymmetries from Compton scattered photons scattered from a high-pressure polarized 3 He gas target.