Compression mode resonances in Zr-90
Abstract
The giant resonance region from 10 MeV < E-x < 55 MeV in Zr-90 has been studied with inelastic scattering of 240 MeV alpha particles at small angles including 0degrees. The isoscalar monopole resonance was found to contain 100 +/- 12% of the E0 energy weighted sum rule with a centroid of (17.81+0.32-0.20) MeV. Eighty one percent of the isoscalar E1 energy weighted sum rule was located in two peaks having E-x=(17.1+/-0.4) and (26.7+/-0.5) MeV, Gamma=(5.4+/-0.3) and (8.8+/-1.0) MeV, and containing 13+/-3% and 70+/-10%, respectively, of the E1 energy weighted sum rule.