Low-energy properties of spin-polarized electron-helium $(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ and spin-polarized positronium-helium $(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ scattering are calculated using the modified confined variational method. To take the van der Waals interaction into consideration, the van der Waals coefficient between positronium and helium $(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ is calculated using the explicitly correlated Gaussian basis. Compared with the ground state noble gases, the larger scattering length and zero pickoff annihilation rate indicates that $\mathrm{He}(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ may be a more suitable cooling gas. In the energy range we considered, no similarity is found for the $S$ -wave cross sections between these two scatterings. A Ramsauer-Townsend minimum is observed in spin-polarized electron-helium $(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ scattering due to the large polarization of metastable helium. This may open a new way to find and study the Ramsauer-Townsend effect.Low-energy properties of spin-polarized electron-helium $(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ and spin-polarized positronium-helium $(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ scattering are calculated using the modified confined variational method. To take the van der Waals interaction into consideration, the van der Waals coefficient between positronium and helium $(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ is calculated using the explicitly correlated Gaussian basis. Compared with the ground state noble gases, the larger scattering length and zero pickoff annihilation rate indicates that $\mathrm{He}(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ may be a more suitable cooling gas. In the energy range we considered, no similarity is found for the $S$-wave cross sections between these two scatterings. A Ramsauer-Townsend minimum is observed in spin-polarized electron-helium$(2\phantom{\rule{0.16em}{0ex}}^{3}S)$ scattering due to the large polarization of metastable helium. This may open a new way to find and study the Ramsauer-Townsend effect.

Physical Review AMay 5, 20215 citations

Spin-polarized hydrogen

Jook T. M. Walraven

Physica B+CNov 1, 19848 citations

Low-energy properties of spin-polarized electron-helium

(2\phantom{\rule{0.16em}{0ex}}^{3}S)

and spin-polarized positronium-helium

(2\phantom{\rule{0.16em}{0ex}}^{3}S)

scattering are calculated using the modified confined variational method. To take the van der Waals interaction into consideration, the van der Waals coefficient between positronium and helium

(2\phantom{\rule{0.16em}{0ex}}^{3}S)

is calculated using the explicitly correlated Gaussian basis. Compared with the ground state noble gases, the larger scattering length and zero pickoff annihilation rate indicates that

\mathrm{He}(2\phantom{\rule{0.16em}{0ex}}^{3}S)

may be a more suitable cooling gas. In the energy range we considered, no similarity is found for the

S

-wave cross sections between these two scatterings. A Ramsauer-Townsend minimum is observed in spin-polarized electron-helium

(2\phantom{\rule{0.16em}{0ex}}^{3}S)

scattering due to the large polarization of metastable helium. This may open a new way to find and study the Ramsauer-Townsend effect.