Building a vertical drift chamber for the KVI Big-Bite Spectrometer

The superconducting K=600 cyclotron AGOR, presently under construction at the IPN of Orsay, will be installed at the KVI and commissioned in 1994. In order to take full advantage of the variety of beams that AGOR will provide a magnetic spectrometer is presently under construction and will be installed next year. This Big-Bite Spectrometer (BBS) has a large solid angles including 0 deg C. The combination of this new instrument with a high-energy (5-20 MeV) γ-ray spectrometer with good resolution will create unique possibilities for the measurements of the neutron skin thickness of nuclei. A novel method was developed to investigate this fundamental quantity, based on the fact that the giant dipole resonance (GDR) excitation cross section by inelastic α-scattrering depends strongly on the neutron skin thickness of nuclei. (N.T.) 3 refs