3. DESCRIPTION OF PROGRAM OR FUNCTION
POISSON, SUPERFISH is a group of (1) codes that solve Poisson's equation and are used to compute field quality for both magnets and fixed electric potentials and (2) RF cavity codes that calculate resonant frequencies and field distributions of the fundamental and higher modes. The group includes: POISSON, PANDIRA, SUPERFISH, AUTOMESH, LATTICE, FORCE, MIRT, PAN-T, TEKPLOT, SF01, and SHY.
POISSON solves Poisson's (or Laplace's) equation for the vector (scalar) potential with nonlinear isotropic iron (dielectric) and electric current (charge) distributions for two-dimensional Cartesian or three-dimensional cylindrical symmetry. It calculates the derivatives of the potential, the stored energy, and performs harmonic (multipole) analysis of the potential.
PANDIRA is similar to POISSON except it allows anisotropic and permanent magnet materials and uses a different numerical method to obtain the potential.
SUPERFISH solves for the accelerating (TM) and deflecting (TE) resonant frequencies and field distributions in an RF cavity with two-dimensional Cartesian or three-dimensional cylindrical symmetry. Only the azimuthally symmetric modes are found for cylindrically symmetric cavities.
AUTOMESH prepares input for LATTICE from geometrical data describing the problem, (i.e., it constructs the "logical" mesh and generates (x,y) coordinate data for straight lines, arcs of circles, and segments of hyperbolas).
LATTICE generates an irregular triangular (physical) mesh from the input data, calculates the "point current" terms at each mesh point in regions with distributed current density, and sets up the mesh point relaxation order needed to write the binary problem file for the equation-solving POISSON, PANDIRA, or SUPERFISH.
FORCE calculates forces and torques on coils and iron regions from POISSON or PANDIRA solutions for the potential.
MIRT optimizes magnet profiles, coil shapes, and current densities from POISSON output based on a field specification defined by the user.
PAN-T calculates the temperature distribution in the walls of a
RF-cavity given the electric field at the walls, the thermal conductivity of the wall materials, and the temperature at the outer surface of the wall.
TEKPLOT plots the physical boundaries and mesh resulting from a
LATTICE run and equipotential or field lines generated as a result of POISSON, PANDIRA, MIRT, or SUPERFISH runs.
SF01 and SHY process results from SUPERFISH runs. SF01 calculates quantities useful for a drift-tube linac. SHY calculates the value of the electric field in the TM mode over an area in the XY-plane.