Nuclear Physics – K600 Magnetic Spectrometer


The K=600 light ion spectrometer at iThemba LABS consists of five active elements namely a quadrupole, two dipoles and two trim coils, referred to as the K and H coils. It is based on the design of the former K=600 magnetic spectrometer at the Indiana University Cyclotron Facility. As an indication of its size, the average flight path for a particle from target to detector is approximately 8m. It is one of the very few light ion spectrometers in the world that can be used to make high energy-resolution measurements in the proton energy region up to 200 MeV.

The focal plane position-sensitive detector package is positioned behind the second dipole, and consists of multi-wire drift chambers and a pair of plastic scintillation detectors. By employing dispersion matching techniques an energy resolution of 30 keV FWHM can be achieved at 200 MeV for (p,p’) reactions at scattering angles as low as 7°.

The K600 is used in the investigation of nuclear structure as well as in various reaction mechanism studies.

A K600 0° Facility, funded by the NRF and the German research funding organisation Deutsche Forschungsgemeinschaft (DFG), allows measurements of inelastic proton or alpha scattering as well as transfer reactions such as the (p,t) reaction, at very small angles, including zero degrees. Such measurements can address a number of important questions concerning, amongst other, the properties of the isoscalar giant monopole and dipole resonances and their relation to the nuclear equation of state or the mapping of Gamow- Teller (GT) strength distributions relevant for the understanding of supernova dynamics.