ImpactX
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#include <SoftQuad.H>
Public Attributes | |
amrex::Vector< amrex::ParticleReal > | default_cos_coef |
amrex::Vector< amrex::ParticleReal > | default_sin_coef |
Default Fourier coefficients
Fourier coefficients for the on-axis quadrupole field gradient k = 1/(Brho)*dBy/dx as a function of longitudinal position z. The default on-axis gradient is described by the function: k(z) = gscale/2*(tanh((z-zi)/g) - tanh((z-zf)/g)), where zf = -zi = L/2, L is the magnetic length of the quadrupole, and g is the full gap parameter. Here the parameters are chosen so that g/L = 1/10. This is based on a similar model used for soft-edge elements in MaryLie and ML/I, eg. http://www.physics.umd.edu/dsat/docs/MaryLieMan.pdf
This is equivalent to a single-parameter Enge model for the fields in the fringe region.
Usually superseded by user-provided input values.
amrex::Vector<amrex::ParticleReal> impactx::Quad_field_data::default_cos_coef |
amrex::Vector<amrex::ParticleReal> impactx::Quad_field_data::default_sin_coef |