Status Report on the SIN Universal Spectrometer Installation (SUSI)

Abstract

At an early stage of planning the experimental facilities at SIN it was decided to build a high resolution π-channel and a π-spectrometer for nuclear structure studies. For the π-channel an achromatic system with a large dispersion at the intermediate focus was designed in order to provide a versatile beam line for different kinds of experiments. The lay out is shown in Fig. 1. The π-channel consists of two ion optically almost symmetric sections. The first one (consisting of the quadrupoles Q₁ – Q₆, the separator S, the compensating magnets M_s, the bending magnet M1 and the beam blocker B) disperses the pion beam (produced at the target P) in the horizontal plane at M. At this point a horizontal focus is also required in order to select the pion momenta by means of a MWPC (C₁). The second section (consisting of the bending magnet M2 and the quadrupoles Q₇ – Q₁₀ recombines the dispersed beam into an achromatic beam spot on the scattering target (1 cm x 2 cm). The second MWPC (C₂) determines the incident angle of the pions on the target.

ETH-GRENOBLE-HEIDELBERG-KARLSRUHE-NEUCHÂTEL-SIN-COLLABORATION. (J. Arvieux, E.T. Boschitz, R. Corfu, J. Domingo, J.P. Egger, K. Gabathuler, P. Gretillat, Q. Ingram, C. Lunke, E. Pedroni, C. Perrin, J. Piffaretti, E. Schwarz, C. Wiedner, J. Zichy.)