Strong Focusing Synchrotron

Abstract

This chapter introduces the strong focusing alternating gradient (AG) and separated function synchrotrons. It provides the theoretical material which the simulation exercises lean on. The chapter begins with a brief reminder of the historical context, and continues with beam optics, chromaticity, acceleration, resonances and resonant extraction, dynamical effects of synchrotron radiation (SR), the electromagnetic SR impulse, and depolarizing resonances. This resorts to basic charged particle optics, acceleration, and dynamics in magnetic fields introduced in the previous chapters. The simulation of a strong focusing AG synchrotron requires just two optical elements from library: DIPOLE or MULTIPOL to simulate a combined function dipole, and DRIFT to simulate straight sections. Main dipoles in a separated function synchrotron can use BEND. It requires in addition quadrupoles, simulated using QUADRUPO or MULTIPOL. The latter can simulate higher order lenses, which can otherwise resort to SEXTUPOL, OCTUPOLE, etc. Acceleration uses CAVITE. Accounting for synchrotron radiation (SR) energy loss requires SRLOSS. Monte Carlo SR monitoring can use SRPRNT, which logs data in zgoubi.res. SRPRNT[PRINT] in addition logs data in zgoubi.SRPRNT.Out. Computation of synchrotron radiation (SR) Poynting and spectral brightness uses . Particle monitoring requires keywords introduced in the previous Chapters, including FAISCEAU, FAISTORE, possibly PICKUPS, and some others. Spin motion computation and monitoring resort to SPNTRK, SPNPRT, FAISTORE. Optics matching and optimization use FIT[2]. INCLUDE is used, mostly here in order to simplify the input data files. SYSTEM is used to, mostly, resort to gnuplot so as to end simulations with some specific graphs. Data for the latter are read from output files filled up during the execution of the code, such as zgoubi.fai (resulting from the use of FAISTORE), zgoubi.plt (resulting from IL$$=$$ = 2), or other zgoubi.*.out files resulting from a PRINT command. Stepwise particle data logged in zgoubi.plt are used by the interface zpop to compute the electric field impulse of SR and subsequent spectral angular energy density of the radiation.