iThemba Labs

iThemba Labs

In the picture the K600 magnetic spectrometer is shown. On the right-hand side the beam line, the target chamber and
several vacuum pumbs can be seen. The huge spectrometer consisting of dipole and quadrupole magnets
is placed in the middle of the picture. The focal plane detector system is shown on the left-hand side. It is shielded
with a massive lead against radiation background coming from the beam dump and the scattering chamber. In the picture
is working at the electronics. The spectrometer is painted in blue and in yellow colors.

The iThemba Laboratory for Accelerator Based Sciences is located in Cape Town, South Africa and addresses many different areas like particle radiotherapy for the treatment of cancer, supply of accelerator-produced radioactive isotopes and basic and applied research using particle beams. Our focus is on the K600 magnetic spectrometer which offers the possibility to investigate the structure of nuclei in high-resolution proton scattering experiments. It consists of five magnets namely a quadrupole, two dipoles and two trim coils. Due to dispersion matching techniques an energy resolution of 25keV (FWHM) is possible using a proton beam up to an energy of 200 MeV. The detector system on the focal plane consists of several multi-wire drift chambers which allow to reconstruct the energies and the scattering angles of the deflected protons.

The pictures displays the focal plane detector system of the K600 magnetic spectrometer. The three multi wire drift
chambers and two scintillators for starting the drift time measurement can be seen.

Using the K600 magnetic spectrometer we mainly investigate „Mixed-Symmetry States“ and Giant Resonances like the Isovector Dipole Resonance or the Isoscalar Quadrupole Resonance. The cross section measured in proton scattering exhibits an useful additional observable to understand the structure and the properties of these two classes of nuclear excitations.

Very recently a new 0° scattering facility has been developed at iThemba LABS. Proton scattering at an scattering angle of 0° degrees offers the unique possibility to measure electromagnetic transition strength below and above the neutron separation threshold with one single experiment.