Search

The inelastic electron scattering cross sections for the excitation of the low-lying states of 6 Li have been measured in the momentum transfer region q = 0.7–1.8 fm − , with emphasis on the transverse transitions to the 3.56 and 5.36 MeV T = 1 states. The intermediate coupling shell-model wave functions both in these states and in the ground state have been determined using radial wave functions generated in finite potentials. The form factors, especially the form factor for the M1 transition to the 3.56 MeV state, are sensitive to the radial distribution of the outer nucleons in 6 Li. The form factor and nucleon distribution of the four 6 Li core nucleons relative to the nuclear center of mass have been deduced from the well-known elastic charge form factor and fitted to a Gaussian shape.

Inelastic electron cross sections for Li6 were measured using the facilities at the 300 MeV linear accelerator of the Institut fur Kernphysik in Mainz. The form factor for theC 2 transition to the 2.184 MeV level is given in the region of momentum transfer 0.4 fm−1

In this paper, we attempt to give a general survey and a comprehensive description of the most significant features of the facilities for electron scattering experiments at the Mainz 300 MeV Linear Accelerator, along with a list of literature, where more detailed information on certain subjects can be found. The accelerator provides energies between 80 and 300 MeV. Scattering angles are available up to 160° resulting in a momentum transfer region up to 3.0 fm −1 . The overall experimental resolution is 0.1%. Cross sections down to 10 −34 cm 2 /sr can be measured. The main features of the apparatus are: an achromatic magnet system with 90° deflection, a double focusing spectrometer, a 75 channel double coincidence detector ladder, spanning a 7% final energy width, and an on-line data acquisition system, together with several beam stabilizing and monitoring systems.

The Mainz electron scattering facility provides energies between 80 and 300 MeV and scattering angles up to 158° which corres-pond to a useful momentum transfer region 0.4 ≤ q ≤ 3.0 fm−1. The accelerator and analyzing system produce approximately 1 μA average current with the overall resolution in the final spectra of usually 0.15% to 0.30%.

The form factor for the excitation of the 5.36 MeV level in 6 Li has been measured in a momentum transfer region q = 0.3 ÷ 1.8 fm -1. Calculations of this form factor were performed with L - S coupled intermediate-coupling shell model wave functions.