ZGOUBI USERS' GUIDE - HEP

Examples 231oÑwü¦INTRODUCTIONSeveral examples of the use of zgoubi are given here. They show the contents of the input and output data files, and arealso intended to help understanding some subtleties of the data definition.Example 1: checks the resolution of the QDD spectrometer SPES 2 of SATURNE Laboratory [32], by means of aMonte Carlo initial object and an analysis of images at the focal plane with histograms. The measured field maps of thespectrometer are used for that purpose. The design of SPES 2 is given in Fig. 45.Example 2: calculates the first and second order transfer matrices of an 800 MeV/c kaon beam line [33] at each of itsfour foci: at the end of the first separation stage (vertical focus), at the intermediate momentum slit (horizontal focus), atthe end of the second separation stage (vertical focus), and at the end of the line (double focusing). The first bending isrepresented by its 3-D map previously calculated with the TOSCA magnet code. The second bending is simulated withDIPOLE. The design of the line is given in Fig. 46.Example 3: illustrates the use of MCDESINT and REBELOTE with a simulation of the in-flight decayG Ëin the SATURNE Laboratory spectrometer SPES 3 [16]. The angular acceptance of SPES 3 is oN \mrd horizontally andSPES 3 is given in Fig. 47.N \mrd vertically; its momentum acceptance is oR \%. The bending magnet is simulated with DIPOLE. The design ofExample 4: illustrates the functioning of the fitting procedure: a quadrupole triplet is tuned from -0.7/0.3 T to field valuesleading to transfer coefficients R12=16.6 and R34=-.88 at the end of the beam line. Other example can be found in [34].Example 5: shows the use of the spin and multiturn tracking procedures, applied to the case of the SATURNE·3 GeVsynchrotron [5, 8, 30]. Protons with (· initial•£vertical spin ) are accelerated throughw Ë •the depolarizingresonance. For easier understanding, some results are summarized in Figs. 49, 50 (obtained with the graphicpost-processor, see Part D).Á ºExample 6: shows ray-tracing through a micro-beam line that involves electro-magnetic quadrupoles for the suppressionof second order (chromatic) aberrations [4]. The extremely small beam spot sizes involved (less than 1 micrometer) revealthe high accuracy of the ray-tracing (Figs. 51).