Intense Polarized Electron Beams from Optically Pumped Helium Discharges

Abstract

Spin conservation in ionizing reactions involving optically oriented 2 3 S 1 metastable helium atoms in a helium discharge has been exploited to produce a continous beam of polarized electrons. A beam polarization of (10±0.5)% is measured, with beam current 0.2 /iA. Electrons extracted from the pulsed discharge afterglow have polarization (14 ±0.7)%. The apparatus is simple and versatile, and should be readily adaptable to atomic and nuclear scattering experiments.

Polarisation nucléaire de 3He gazeux par pompage optique laser

“…realisation de jets polarises, soit d'ions 3He+ [12], soit d'electrons [13], soit encore d'atomes metastables [14]; mise en oeuvre d'un maser Zeeman a 3 He [15] ou d'un magnetometre [16] ; polarisation nucleaire de 3He liquide, soit pur [ 17], soit dilue dans 4He [ 18] ;…”

Preparation of individual magnetic sub-levels of $^4$He($2^3$S$_1$) in a supersonic beam using laser optical pumping and magnetic hexapole focusing

“…In atom optics, He SP has found applications in nanolithography, as well as in atomic waveguides and beamsplitters for atom interferometry [8,9]. He SP also serves as a source of polarized electrons [10,11] and ions [12], e.g., for atomic and high-energy nuclear scattering experiments. Besides that, spin-polarized samples of 3 He(2 3 S 1 ) are used for biomedical imaging, e.g., to visualize the human lung [13][14][15].…”