beam section (mandatory)

Here we define the main properties of the beam at the entrance of the linac. Note that with TraceWin, most of these properties are defined within its own .ini file. The units must be consistent with LightWin’s system of units, see also Units and conventions.

Entry	Type	Description	Mandatory?	Allowed values
e_mev	float	Energy of particle at entrance in:unit:MeV	✅
e_rest_mev	float	Rest energy of particle in:unit:MeV	✅
f_bunch_mhz	float	Beam bunch frequency in:unit:MHz	✅
i_milli_a	float	Beam current in:unit:mA. Warning: this key is not used. EnvelopeiD solvers do not model space-charge, and the current in TraceWin solver is controlled by the current1 key.	❌
q_adim	float	Adimensioned charge of particle	✅
sigma	list or ndarray	Input:math:sigma beam matrix in:unit:m; \(\mathrm{rad}\). Must be a list of lists of floats that can be transformed to a 6*6 matrix.	✅

Format for the sigma entry:

sigma = [
   [ 1e-6, -2e-7,  0e+0, 0e+0,  0e+0, 0e+0],
   [-2e-7,  8e-7,  0e+0, 0e+0,  0e+0, 0e+0],
   [ 0e+0,  0e+0, -2e-7, 8e-7,  0e+0, 0e+0],
   [ 0e+0,  0e+0, -2e-7, 8e-7,  0e+0, 0e+0],
   [ 0e+0,  0e+0,  0e+0, 0e+0, -2e-7, 8e-7],
   [ 0e+0,  0e+0,  0e+0, 0e+0, -2e-7, 8e-7]
 ]