The S800 Spectrograph
The ultimate goal of experiments performed on the S800 spectrograph is to acquire knowledge on atomic nuclei in conditions that are not found in nature except in stars or supernovae. Used in combination with accelerated beams of heavy ions, this instrument allows experimentalists to explore the unknown properties of nuclei involved in the stellar synthesis of all elements found on earth. In a more fundamental aim, it is essential to the understanding of the world of quantum mechanics, for which the system of protons and neutrons that constitute a nucleus is a perfect site.

The S800 spectrograph; D. Bazin, J. A. Caggiano, B.M. Sherrill, J. Yurkon, A. Zeller, EMIS-14 conference proceedings, Victoria, BC, Canada, May 6-10, 2002, Nucl. Instr. Meth. B 204 (2003) 629.

 

The S800 spectrograph combines both high resolution and high acceptance in a single device and is specially designed for reaction studies with radioactive beams. Its large acceptances both in solid angle (20 msr) and momentum (5%) are well adapted to the large emittances of secondary beams produced by projectile fragmentation. The high resolution is achieved via an analytical reconstruction method in which aberrations are calculated a priori from the magnetic field maps and used directly to correct the raw data. The spectrograph is installed vertically on a carriage that can rotate from 0° to 60°. Its maximum rigidity is limited to 4 Teslameter (Tm). The S800 is preceded by an analysis line that allows for different optical modes of operations, either focussing or dispersion matched. The maximum rigidity of the analysis line is limited to 4.9 Tm.