Parameter Name 
Valid Entries 
Description 


RZ, XY 
OM2p only. OM2p will search for modes in either rotationally symmetric cylindrical coordinates (RZ) or Cartesian coordinates (XY). In the RZ coordinate system, the xaxis is the rotational axis. For details see “Coordinate Systems”. 

h0.5, h1.5, h2.5, h3.5, h4.5, c1.5, c2.5, c3.5, c4.5 
The basis set dictates the accuracy of the field representation within each mesh element. The higher the basis set order, the more functions are used, generally resulting in a more accurate result. For more information, see “Basis Set”. 

Integer > zero 
Number of modes to extract above the shift frequency. 

Integer ≥ zero 
OM2p RZ coordinates only. Indicates the desired mode number in the azimuthal direction. 
[FREQUENCY] 
Real number > zero 
Only modes above this frequency will be extracted. This value should be set reasonably close to the first mode of interest to reduce computational costs. 

True, False 
If True, allows user access to settings specific to accelerator problems such as shunt impedance and kick factor. Signals the solver to compute those quantities and output them after the simulation completes. 

True, False 
OM2p RZ coordinates only. If True, the basis set on the axis is increased by one order, to improve modeling of radial field variations on the axis. 
 [LENGTH] 
Three commadelimited real numbers. 
Start point of path used to orient the solution modes, in Cartesian coordinates. 
 [LENGTH] 
Three commadelimited real numbers. 
End point of path used to orient the solution modes, in Cartesian coordinates. 
 [LENGTH] 
Three commadelimited real numbers. 
Visible when Compute Accelerator Results is True. Start point of path used in the shunt impedance calculation, in Cartesian coordinates. 
 [LENGTH] 
Three commadelimited real numbers. 
Visible when Compute Accelerator Results is True. End point of path used in the shunt impedance calculation, in Cartesian coordinates. 
[LENGTH] 
Three commadelimited real numbers. 
Visible when Compute Accelerator Results is True. Start point of path used in the kick factor calculation, in Cartesian coordinates. 
[LENGTH] 
Three commadelimited real numbers. 
Visible when Compute Accelerator Results is True. End point of path used in the kick factor calculation, in Cartesian coordinates. 

Real number ≥ zero 
Visible when Compute Accelerator Results is True. Particle beta as used in the calculation of various output quantities in the mode summary table. 

True, False 
Visible when Compute Accelerator Results is True. If true, the paths specified for the kick factor and shunt impedance calculations are clipped by the actual mesh thus impacting the length of the integrations paths which impact the results of these calculations. If false, the length of the integration paths is strictly determined by the start and end points you specify. 

Linear Range Count, Linear Range Increment, “Custom List Specification” 
Determines how the phase advances are specified. This quantity is only used when periodic boundary conditions are present. 

Conductivity, Resistance 
Method of specifying loss in the cavity walls that have been described with PEC boundary conditions, for use in the computation of surface losses for estimation of cavity Q and power dissipation. It is not used in the eigensolve itself. 
[CONDUCTIVITY] 
Real number ≥ zero 
Visible if Conductivity. This is used in the computation of surface losses for estimation of cavity Q and power dissipation. It is not used in the eigensolve itself. is 
[IMPEDANCE] 
Real number ≥ zero 
Visible if Resistance. This is used in the computation of surface losses for estimation of cavity Q and power dissipation. It is not used in the eigensolve itself. is 

All Modes, None 
Controls field output. 

Energy, Average Accelerating Gradient, Peak Volumetric, Peak Surface, Peak Axial on Axis, Average Accelerating Gradient EField Magnitude 
Controls the manner in which the fields are normalized. 

Real number > zero 
Specifies the value of the field normalization. The unit of this value depends on the value of the field normalization type. 

Automatic, Iterative, Direct 
This flag controls whether the eigensolver uses a direct or iterative method. The Direct method identifies all of the eigenmodes and then selects the appropriate ones based upon sorting criteria. The Direct method is very robust, but it scales very poorly with mesh element count. The Iterative methods converge only one, to at most a few modes of interest, but do so quite rapidly and in a fashion that scales well as the port meshes increase in element count. Except possibly for very small problems, the Iterative methods are the best choice, and the Automatic selection is equivalent to Iterative. 

Real number > zero 
Visible if Iterative. The target residual for convergence of modes. A mode is considered converged if the corresponding eigenpair (mode field pattern and propagation constant) gives a matrix equation residual less than this value. is 

Integer > zero 
Visible if Iterative. This is the maximum number of iterations that the iterative eigensolvers will use to converge the number of modes requested at each port. is 

Automatic, Arnoldi, Lanczos 
Visible if Iterative. The iterative methods include Arnoldi and Lanczos, which implement the symmetric Arnoldi and Lanczos processes, respectively. The Automatic selection is equivalent to Lanczos. is 

True, False 
If true, status messages from the port eigensolver are sent to the Log. 

Automatic, Iterative, Direct 
This parameter controls the type of solver that is used to solve the matrix equation(s). The options are Direct and Iterative. The Direct solver performs an LU factorization of the matrix, and the iterative method uses a variant of the preconditioned conjugate gradient (PCG) method. The Automatic selection is equivalent to Direct, and this is almost always faster than the Iterative option. For more information, see “Linear Solver”. 

CG, BiStabCG, CGS, GMR 
Visible if Eigensolver/Linear Solver/Method is Iterative. Several iterative linear solver methods are available. The CG option invokes the standard preconditioned conjugate gradient method, BiStabCG invokes the stabilized variant of biconjugate gradient, CGS is the conjugate gradient squared method, and GMR is the generalized minimum residual method. Of these, only GMR has the property that the residual error will reduce every iteration, but CG is generally the most efficient. For more information, see “Iterative Methods”. 

Jacobi, GaussSeidel, PMultigrid. 
Visible if Eigensolver/Linear Solver/Method is Iterative. Use of a matrix preconditioner improves the convergence rate of iterative methods. The Jacobi method is the most efficient in terms of computer memory. PMultigrid uses the most computer memory but will result in very short iteration sequences for higherorder elements (it involves a factorization of a portion of the matrix, and is equivalent to using a Direct method if only the lowest order h0.5 basis set is used). 

Real number > zero 
Visible if Eigensolver/Linear Solver/Method is Iterative. When the residual of the matrix equation falls below this value the linear solver considers the result converged. Setting this value too low can cause very long solution times, and setting it too high will result in breakdown of the simulation. 

Integer > zero 
Visible if Eigensolver/Linear Solver/Method is Iterative. This is the maximum number of iterations the linear solver will perform before stopping, irrespective of the size of the matrix equation residual. 

Automatic, Low, Medium, High, Perfect 
The HMLU linear solver produces an inexact LU factorization of the system matrix that is subsequently used in an iterative loop to determine the solution vectors for port/mode excitations. The accuracy of the factor can be controlled via the Factor Accuracy Level solver parameter. Options are Low, Medium, High, Perfect, and Automatic. The Perfect setting yields a factor with an accuracy equivalent to that obtained using the MFLU solver, and will result in the iterative loop converging in a single step. A lower factor accuracy is faster to compute and takes less system memory, as compared to higher accuracy settings, but it can also lead to more iterations being required in the iterative loop. If the Automatic setting is chosen, the solver will adjust the accuracy setting as necessary to minimize runtime and memory, starting with the Low setting. The Automatic setting also allows for failover to a different solver if the default solver cannot solve the problem. 

Full path to optional field output file to be used by other simulators (e.g. PT3p). 


True, False 
If False, the solver will not output the mesh to its dataset, thus reducing computation time and dataset (and thus project) size. This can be useful in cases such as sweeps or optimizations, where mesh data is not necessary. 

Per Material, Never, Always 
This flag controls whether the solver will solve for the field inside metal conductors. This is sometimes necessary to achieve high accuracy solutions. Solving inside conductors generally increases the solution time and should not be done unless the skindepth is comparable to the metal thickness over at least a portion of the frequency band. Otherwise, lossy metal will be approximated using impedance boundary conditions on the metal surface, which will yield sufficient accuracy in most cases without incurring the runtime performance penalty of solving inside the metal. 
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