Evidence for Transient Electric Field Gradients in H-like Ions Traversing Gd Targets at High Velocities

Abstract

Transient electric field gradients have been observed in measurements of particle-{gamma}-angular correlations of Coulomb excited nuclei in H-like ions during traversal through thick metallic layers. The V{sub ZZ} values deduced for {sup 20}Ne( 2{sup +}) , {sup 32}S( 2{sup +}) , {sup 40}Ar( 2{sup +}) , {sup 52}Cr( 2{sup +}) , {sup 54}Fe( 2{sup +}) , and {sup 62}Ni( 2{sup +}) are found to be of the order of 10{sup 21} V/cm{sup 2} with consistently positive sign. They arise from distortions of the 1s electron orbit of the H-like ions by the wake field gradient induced in the solid by the charge of the moving ion. The observed interaction frequencies reflect the sign of the quadrupole moment of the excited 2{sup +} states. {copyright} {ital 1997} {ital The American Physical Society}