Abstract

Disclosed are a system, and method, for producing a directly extracted flow of preferred-spin-polarization-direction electrons. The present invention optically pumped electron spin filter system provides a mixture of, typically alkali, atoms and electron polarization direction enhancing buffer gas, to a, preferably, single chamber essentially enclosed space, into which essentially enclosed space is entered a predominately single handedness, preferably laser system produced, beam of photons which optically pumps electrons in atoms to a dark-ground state with a preferred-spin-polarization, that is maintained in the presence of an imposed magnetic field, which magnetic field is oriented essentially co-linear with said beam of predominately single polarized photons. Concurrently electrons are, by practice of the method of the present invention, generated in the essentially enclosed space by a buffer gas mediated electric discharge, and are caused to be in a preferred-spin-polarization-direction via pumped dark-ground state atom--electron collision mediated exchange mechanism(s), prior to being directly extracted.

Other References

• "Polarized Electrons In Surface Physics" Edited by R. Feder, (World Scientific, Singapore, 1985)
• "Polarized Gas Targets And Polarized Beams", (Seventh International Workshop), Edited by Holt and Miller, AIP Conference Proceedings Series CP421, (AIP New York 1998)
• "The Scattering Of Fast Electrons By Atomic Nuclei" Mott, Proc. R. Soc., London, Ser. A 124, 425 (1929) and "Stern-Gerlach Effect For Electron Beams", Batelaan, Gay, Schwendiman, Phys. Rev. Lett. 79, 4517 (1997)
• "Electron Polarization", Shull et al., Phys. Rev. 63, 29 (1943)
• "A Method Of Measuring The Gyromagnetic Ratio Of The Free Electron", Louisell et al., Phys. Rev. 91, 475 (1953)
• "A Source Of Highly Spin-Polarised Slow Electrons Based On The `Fano Effect` On Caesium Atoms", Mollenkamp et al., J. Phys. E. 15, 692, (1982)
• "GaAs Spin Polarized Electron Source", Pierce et al., Rev. Sci. Instrum. 51, 478 (1980) and the previously cited Holt and Miller reference
• "Improved Source Of Polarized Electrons Based On A Flowing Helium Afterglow", Rutherford et al., Rev. Sci. Instrum. 61, 1460 (1990); and
• "The Orsay Polarized Electron Source From A Flowing Helium Afterglow", Arianer et al., Nucl. Instrum. Meth. A 382, 371 (1996)
• "Cumulative Ionization In Optically Pumped Helium Discharges: A Source Of Polarized Electrons", McCusker et al.Phys. Rev. A 5, 177 (1972)
• "The Production Of Polarized Electron Beams By Spin Exchange Collision", Fargo et al.,Phys. Lett. 20, 279 (1966)
• Fargo, et al., title "The Production Of Polarized Electron Beams By Spin Exchange Collision", Phys. Lett. 20, 279 (1966)
• "On A Source Of Polarized Electrons", Campbell et al. Proc. R. Soc. Edinb. A, Math. 70, 15 (1971/72); and
• "Theoretical Consideration Of Spin-Polarized Electron Source Based On Elastic Electron-Hydrogen Spin-Exchange Collisions", Krisciokaitis-Krisst et al., Nucl. Instrum. Methods Phys. Res. (Netherlands) 83, 45 (1970)
• "Prototype Polarized-Electron Source Through Electron-Hydrogen Spin Exchange With Teflon Containment Of Hydrogen And A Longitudinal Magnetic Trap", Nucl. Instrum. Methods Phys. Res. (Netherlands) 118, 157 (1974)
• "Neutron Polarization With A Polarized ³ He Spin Filter", Coulter et al., Nucl. Instrum. Methods Phys. Res. A, Accel. Spectrom. Detect. Assoc. Equip. (Netherlands) 288, 463, (1990)
• "Electron Transmission Through Ultra-thin Metal Layers And Its Spin Dependence For Magnetic Structures", Drouhin et al.J. Magn. Mat. 151, 417 (1995)
• "Transmission Of Electrons Through Ferromagnetic Material And Applications To Detection Of Electron Spin Polarization", Schonhense et al., Ann. Physik. (Liepzig) 2, 465, (1993)
• Talks given by the inventors herein appeared in Compilations of Abstracts, one for the American Physical Society Conference, in April, vol. 42, No. 2 (1997); and one for the Gaseous Electronics Conference, Oct. vol. 42, No. 8
• Rb density measurement using a Faraday rotation method is described by Knize et al. in an article which appeared in Adv. At. Mol. Phys. 24, 223 (1988)
• "Effect Of Radiation Trapping On The Polarization Of An Optically Pumped Alkali-Metal Vapor"; Tupa et al., in Phys. Rev. A 33, 1045 (1986), discusses the presence of buffer gas on polarization of P_Rb at this density could not be pumped above ten (10%) percent
• "Polarized, High-density, Gaseous ³ He Targets", Chupp et al, Physical Rev. C, Vol 36, No. 6, (1997)
• "Optical Pumping Of High-Density Rb With A Broadband Dye Laser And GaAs Diode Laser Arrays: Application to ³ He Polarization", Wagshul et al., Phys. Rev. A, vol. 40, No. 8, (1989)
• "Effect Of Radiation Trapping On The Polarization Of An Optically Pumped Alkali-Metal Vapor In A Week Magnetic Field", Tupa et al., Phys. Rev. A, vol. 36, No. 5, (1987)
• "On The Production Of Polarized Electron Beams By Spin Exchange Collisions", Byrne et al., Proc. Phys. Soc., Vol 86, (1965)
• An article titled "Effect Of Radiation Trapping On The Polarization Of An Optically Pumped Alkali-Metal Vapor"by Tupa et al., which appeared in Phys. Rev. A 33, 1045 (1986), discusses the presence of buffer gas on polarizarion on P_Rb at this density could not be pumped above ten (10%) percen