Abstract
The spin polarized electron source developed at Orsay uses the chemi-ionization of CO{sub 2} gas by polarized metastable helium atoms to produce free polarized electrons. A new scheme of optical pumping is applied, using D{sub 0} resonance line of helium by combining {sigma} and {pi} polarized light. The pumping beam is split along two perpendicular directions. The flow velocity of the afterglow is increased by using high speed mechanical pumps, yielding high metastable densities by reducing the loss of metastable diffusing to the walls. Theoretically, with this method, the electron polarization can reach 100 pc. but in the experiment, the helium atoms are polarized to 85 pc. Their polarization increases when {pi} pumping is added to the {sigma} one. 30 to 45 pc. electron polarization that is observed is related to a degradation close to the extraction region (collection of spurious electrons).
Citation Formats
Humblot, H.
A contribution to the study and the realization of a spin polarized electron source with helium afterglow; Contribution a l`etude et a la realisation d`une source a electrons polarises a post-decharge d`helium.
France: N. p.,
1993.
Web.
Humblot, H.
A contribution to the study and the realization of a spin polarized electron source with helium afterglow; Contribution a l`etude et a la realisation d`une source a electrons polarises a post-decharge d`helium.
France.
Humblot, H.
1993.
"A contribution to the study and the realization of a spin polarized electron source with helium afterglow; Contribution a l`etude et a la realisation d`une source a electrons polarises a post-decharge d`helium."
France.
@misc{etde_10127449,
title = {A contribution to the study and the realization of a spin polarized electron source with helium afterglow; Contribution a l`etude et a la realisation d`une source a electrons polarises a post-decharge d`helium}
author = {Humblot, H}
abstractNote = {The spin polarized electron source developed at Orsay uses the chemi-ionization of CO{sub 2} gas by polarized metastable helium atoms to produce free polarized electrons. A new scheme of optical pumping is applied, using D{sub 0} resonance line of helium by combining {sigma} and {pi} polarized light. The pumping beam is split along two perpendicular directions. The flow velocity of the afterglow is increased by using high speed mechanical pumps, yielding high metastable densities by reducing the loss of metastable diffusing to the walls. Theoretically, with this method, the electron polarization can reach 100 pc. but in the experiment, the helium atoms are polarized to 85 pc. Their polarization increases when {pi} pumping is added to the {sigma} one. 30 to 45 pc. electron polarization that is observed is related to a degradation close to the extraction region (collection of spurious electrons).}
place = {France}
year = {1993}
month = {Mar}
}
title = {A contribution to the study and the realization of a spin polarized electron source with helium afterglow; Contribution a l`etude et a la realisation d`une source a electrons polarises a post-decharge d`helium}
author = {Humblot, H}
abstractNote = {The spin polarized electron source developed at Orsay uses the chemi-ionization of CO{sub 2} gas by polarized metastable helium atoms to produce free polarized electrons. A new scheme of optical pumping is applied, using D{sub 0} resonance line of helium by combining {sigma} and {pi} polarized light. The pumping beam is split along two perpendicular directions. The flow velocity of the afterglow is increased by using high speed mechanical pumps, yielding high metastable densities by reducing the loss of metastable diffusing to the walls. Theoretically, with this method, the electron polarization can reach 100 pc. but in the experiment, the helium atoms are polarized to 85 pc. Their polarization increases when {pi} pumping is added to the {sigma} one. 30 to 45 pc. electron polarization that is observed is related to a degradation close to the extraction region (collection of spurious electrons).}
place = {France}
year = {1993}
month = {Mar}
}