M.N. Martins

Electrodisintegration of 208Pb, 209Bi and 181Ta

The electrodisintegration cross section has been measured for 208Pb, 209Bi and 181Ta, from threshold to 22 MeV, by detecting the emitted neutrons. The quantity measured is sigma e,Tn= sigma e,n+2 sigma e,2n. The results are analysed with DWBA virtual photon spectra for finite nuclei to obtain M1 and E2 strengths.

Disintegration of the deuteron by linearly polarized photons at low energies

Abstract The cross section and the Σ -asymmetry of the reaction d (γ → ,p) were measured in the energy interval E γ = 5–10 MeV. Cross sections dσ and dσ ⊥ were derived from the measured quantities dσ 0 and Σ -asymmetry. The results are compared with theoretical calculations available for this energy region.

M1 strength in 197Au

The electrodisintegration of 197Au was measured by residual activity from threshold to 23 MeV. The results are analysed with DWBA virtual photon spectra for finite nuclei (E1 and E2 multipoles, point DWBA for M1) to obtain M1 and E2 strengths.

Nuclear size effects in virtual photon spectra

The (e,n) cross section has been measured for 181Ta from threshold to 30 MeV. The results are compared with the cross sections predicted by virtual photon theory using different corrections for nuclear size effects.

An analysis of electrodisintegration of nuclei using E1 virtual radiation spectra evaluated with coulomb distorted waves

Abstract Data on the ratio of photodisintegration to electrodisintegration of several nuclei (12C, 63Cu, 64Zn, 109Ag, 181Ta and 197Au) are compared with the theoretical ratios predicted by plane-wave and distorted-wave calculations. The analysis with distorted waves shows that all data are compatible with photoabsorption through dominant E1 transitions, as can be explained by the electric dipole sum rule. This outcome does not agree with published conclusions for high Z using the plane-wave approximation.

Study of 7Li(p, pn) and 7Li(p, 2p) reactions at 70 MeV

Abstract Differential cross sections for the reactions 7 Li( p , pn ) and 7 Li( p , 2 p ) were simultaneously measured at an incident proton energy of 70 MeV. The measured spectra were decomposed into contributions from 1 p and 1 s shells. The obtained cross sections were analyzed in the framework of the DWTA approach.