Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
An Inline Optical Electron Polarimeter, K. W. Trantham, Timothy J. Gay, R. J. Vandiver
An Inline Optical Electron Polarimeter, K. W. Trantham, Timothy J. Gay, R. J. Vandiver
Timothy J. Gay Publications
The design and operation of a simple inline optical electron polarimeter is presented. It is based on exchange excitation of ground state neon atoms. The electron polarization is determined from the degree of circular polarization of the subsequent 2p53p 3D3→2p53s 3P2 (6402 Å) fluorescence. This device can characterize both longitudinally and transversely polarized electron beams in a nondestructive fashion, and is inexpensive and easily constructed.
Current Status Of The Saddle-Point Model, Timothy J. Gay
Current Status Of The Saddle-Point Model, Timothy J. Gay
Timothy J. Gay Publications
The saddle-point model of ionizing ion-atom collisions is based on the idea that when a charged projectile ionizes target electrons. some of the ejected electrons find themselves on the transient, moving saddle-point of Coulomb potential with a velocity that matches that of the saddle point. Feeling no force at this position, they "ride" the saddle out of the collision volume and are thus ionized. In the case of the prototypical H+ + H system, or in any proton–neutral target collision, the saddle point moves at half the projectile velocity, so these electrons are often referred to as "v/2" electrons. …
Optical Electron Polarimetry With Heavy Noble Gases, Timothy J. Gay, J. E. Furst, K. W. Trantham, W. M. K. P. Wijayaratna
Optical Electron Polarimetry With Heavy Noble Gases, Timothy J. Gay, J. E. Furst, K. W. Trantham, W. M. K. P. Wijayaratna
Timothy J. Gay Publications
We have measured the polarization of fluorescence emitted by the noble gases He, Ne, Ar, Kr, and Xe following impact excitation by polarized electrons. In He, the 33P→23S transition was studied; in the heavy noble gases the np5 (n+1) p 3D3→np5 (n+1) s3P2 transitions were analyzed. We investigated these transitions as candidates for efficient optical electron polarimetry and found that, because of their larger excitation cross sections and analyzing power, the heavy noble gases are superior to He, which had been used …
Failure To Observe Electron Circular Dichroism In Camphor, K. W. Trantham, M. E. Johnston, Timothy J. Gay
Failure To Observe Electron Circular Dichroism In Camphor, K. W. Trantham, M. E. Johnston, Timothy J. Gay
Timothy J. Gay Publications
Analogous to optical circular dichroism, it is possible to have electron circular dichroism, the preferential transmission of longitudinally polarized electrons through a chiral medium. Using stereoisomers of camphor vapor as a scattering target, we looked for this effect at incident electron energies of 1, 3, 5, 7, or 10 eV. Within our detection limit (~0.02%) we have not observed a spin-dependent asymmetric transmission.
Résumé : En analogie avec le dichroïsme circulaire optique, il est possible d'avoir un dichroïsme circulaire électronique, la propagation préférentielle d'électrons polarisés longitudinalement à travers un milieu chiral. Utilisant de la vapeur de stéréoisomères de carnphre comme …