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13.1 Adapting simulation parameters to fit reference path

The radii of the four dipole magnets habe been manually adapted to fit the geometry of the dogleg. The focus has been on introducing an

-offset of

m after each set of two dipoles, and keeping a beamline parallel to the

-axis on both sides of these two dipoles sets. Table 13.1 references the values used to obtained the desired reference path. Figure 13.2 represents the simulated reference path, with the exact geometry of the four dipoles. On figure 13.3, the deflection angle $\arctan\frac{dx'}{dz}$ , is plotted along the trajectory. The deflection angle is $\alpha=20.94$ $^\circ$ instead of the value 22.5 $^\circ$ expected by the designed geometry.

**Figure 13.1:** Scheme of an emittance exchanger made of 4 dipoles and corresponding sign of magnetic fields

Table 13.1: Dipole radii needed by astra to fit the geometry

	Dipole 1	Dipole 2	Dipole 3	Dipole 4
Radius $\rho$ [m]	-0.598	0.598	-0.595	0.595

**Figure 13.2:** Reference path through the four dipoles in the dogleg configuration

**Figure 13.3:** Deflection angle along the trajectory through the dogleg

Emmanuel Branlard
http://emmanuel.branlard.free.fr/