# Release Notes

The release notes describes new features for the VSim computational engine (Vorpal) and the VSimComposer graphical user interface. Deprecated features and bug fixes are also noted within the release notes.

## New and Updated VSim 8.1 Features

The following features are new or have been updated for the 8.1 release.

### VSim Computational Engine (Vorpal)

• Scattering processes added for antimony (Sb), including electron-electron scattering
• Added transport and emission from antimony (Sb) using the density of states
• Added model to specify percentage of specular and diffusive emissions
• Fixed issues with several commandline arguments including -h and –help
• Improved warnings when improper values are given for simulation parameters
• Fixed issue with line dumping without a name
• Fixed issue where all 3 components of deltaAtBreaks were not checked to determine if the grid is uniform
• Fixed energy conservation for binary elastic Monte Carlo collisions
• Improved error recovery and reporting for the Filter Diagonalization analyzer

### VSim Examples

These examples now have Visual Setup:

• A Loop Antenna created from a coaxial cable (VSimEM) : See Example
• Horn Antenna (VSimEM) : See Example
• Patch Antenna Far Field (VSimEM) : See Example
• Rectangular Waveguide (VSimEM) : See Example
• Electron Gun (VSimMD) : See Example
• Gyrotron Mode (VSimMD) : See Example
• Helix Traveling Wave Tube 1: Dispersion (VSimMD) : See Example
• Helix Traveling Wave Tube 2: Impedance and Attenuation (VSimMD) : See Example
• Helix Traveling Wave Tube 3: Power Run (VSimMD) : See Example
• 2D Magnetron (VSimMD) : See Example
• Multipacting Resonance in Waveguide (VSimMD) : See Example
• Multistage Collector (VSimMD) : See Example
• 3D Stripline Multipacting (VSimMD) : See Example

Other example features include:

• Updated examples to take advance of new macro functionality
• Added the numerical Cerenkov filter option to EM examples
• Improved Photonic Crystal examples

### VSim Macros and Translator

• New macro to allow numerical Cerenkov filters in Visual Setup as a parameter of the field solver
• New macro, stfuncs.mac, to handle built-in Space-Time functions including Python file import and feedback
• Added support to set localVelocity parameter off of shape emitters
• Updated the reflecting particle boundary macros to handle rails and corners
• Added history to let user set pseudoPotential by coordinates in addition to via grid index
• Added support for secondary emitters to test particles
• Added support to simplify creation of rectangular and coaxial waveguides
• Fixed issue with HalfWave Dipole Antenna failing on GPU
• Fixed several issues dealing with handling of cylindrical coordinates
• Improved performance of filters macro
• Improved embcs.mac and VSimEm.mac for a faster implement of MAL boundaries
• Removed unused macros, remove unneeded parameters, and cleaned up referenced inside macros
• Fixed several issues with histories.mac for logging of ptclQty and speciesAbsPtclData
• Fixed issue with parallel restarts on Win10 with CAD geometries
• Fixed issue with specifying name of external magnetic fields
• Better handling of global variables in macros

### VSim Analyzers

• Improvements to data analysis executables. : See Analysis Scripts
• New analyzer, exportSpecies.py, that exports a particle species to a text file or sequence of text files
• New analyzer, getFieldComponentsOnPlane.py, to get field components on a plane
• Updated the computePtclNumDensity.py analyzer to perform spatial averaging
• Improved addPtclComponentKEeV.py, fixing bug involving mismatched components after multiple runs, adding check on restart, executing dump files in numerical order, better specifying of KEeV, KEeVx, KEeVy, or KEeVz, all in one script

### VSim Graphical User Interface (VSimComposer)

• Improvements to tree-based/visual setup : See Visual-setup Simulations
• Fixed issue in visual setup current sources changing field specified from E-Field to a proper J-Field
• Better handling of Space-Time functions in Visual Setup tree
• Added support for Field Scaling Electrons
• Improved Constructive Solid Geometry tessellation and meshing for geometry primitives
• Improved speed of Visual Setup rendering
• Added support for geometries described by Python functions
• Improved expression handling in Visual Setup tree
• Fixed issues with certain plots incorrectly displaying in Visualization Tab
• Fixed automatic scrolling issues in Run and Analyze Tabs
• Added support for scaling and translation of STL files
• Added support for all macro changes above in Visual Setup tree
• Fixes issues with resizing of the grid
• Improved usability and robustness of Visual Setup tree interface
• Improved wildcard searching in Documentation/Help
• Reduced the verbosity of search results in Documentation/Help
• Added instructions on searching in Documentation/Help
• Improved navigation in sidebar contents in Documentation/Help
• Fixed issue with equation rendering speed in Documentation/Help.
• Improved appearance of overall Documentation/Help formatting
• Improved documentation of Visual Setup
• Improved operation under node-locked license

### Other

• Over 50 use issues fixed.

## Known Issues in VSim 8.1

• Remote VSimComposer does not work
• Windows Cluster support was lost with upgrade to MPI on windows needed for certain simulations.
• EM Cylindrical not implemented for visual setup
• Occasionally, for parallel runs, the stl reader can spuriously set some regions outside of objects to being inside. When this happens, it is manifest in the visualization of the corresponding geometry field in Data Overview. In all cases observed so far, this has been fixed by offsetting the grid a small amount, changing the number of cells, and/or changing the number of parallel processes.

## New and Updated VSim 8.0 Features

The following features are new or have been updated for the 8.0 release.

### VSim Computational Engine (Vorpal)

• New package: VSim for Semiconductor Devices for modeling electron transport in diamond or Gallium Arsenide : See VSim for Semiconductor Devices
• Fast dielectric algorithm can take multiple dielectrics assigned to multiple shapes : See multiDielectricUpdater
• Windows Cluster Support with graceful shutdown of job : See Windows HPC Cluster
• Automatic detection of GPU acceleration : More info on GPU Computing
• Ability to use cross-section data files from a user definable location : See SIM_DATA_PATH
• 17+ new simulation object kinds (including Species, Particle Sources/Sinks, Emission Models, Histories, Field Updaters, Grids, Grid Boundaries, and Domains)
• Improved reliability of fast electrostatic solves on linux

### VSim Analyzers

• VSim now comes with more than 30 data analysis executables. : See Analysis Scripts
• Standardization of all analyzers so that user defined input will show up as entry boxes.

### VSim Graphical User Interface (VSimComposer)

• Easy, configurable tree-based/visual setup for many problems : See Visual-setup Simulations
• Ability to import materials from a file. : See Importing Materials
• Easily switch between different simulation types (electrostatic, electromagnetic, with or without particles) with GUI adapting to the selection. : See Basic Settings
• Import CAD objects from multiple formats (step, stl, ply, vtk) and set materials of those objects : See Geometries
• Multiple Geometry shapes can be visually added to simulation. : See Geometries
• Ability to define parts through constructive solid geometry. : See Geometries
• Ability to define expressions and parameters and use those in defining the simulation. : See Parameters and See Functions and : See SpaceTimeFunctions
• Ability to assign materials to parts, regardless of how they were imported or constructed. : See Importing Materials
• Uniformization of output across all platforms.
• Multiple simulations can be saved to one directory.

### Other

• Over 373 use issues fixed.

## Known Issues in VSim 8.0

• Remote VSimComposer does not work
• EM Cylindrical not implemented for visual setup
• Occasionally, for parallel runs, the stl reader can spuriously set some regions outside of objects to being inside. When this happens, it is manifest in the visualization of the corresponding geometry field in Data Overview. In all cases observed so far, this has been fixed by offsetting the grid a small amount, changing the number of cells, and/or changing the number of parallel processes.

## Deprecated Features

### VSim Computational Engine (Vorpal)

The following engine features are deprecated as of the VSim 7.0.0 release and may no longer be supported in future releases of VSim:

#### Attributes Deprecated in Version 8.0

• The kinds bitRevDensSrc, bitRevDensSrcVW, gaussDensSrc, gridDenSrcVW, and planarPtclEmitter of the ParticleSource block have been deprecated.

• Please use the xvLoaderEmitter kind instead.
• kind is deprecated for the Decomp block. The regular decomposition is the only one available and therefore this attribute is not needed at all.

• Please simply omit “kind = ” from the Decomp block
• stCadRgn kind of STRgn block has been deprecated.

• Please use gridRgnBndry kind of GridBoundary block instead. The gridRgnBndry is a much faster method for importing STL geometries.
• cell kind of Species block has been deprecated.

• Please use any of the remaining kinds listed under Species Kinds

#### Features Deprecated in Version 8.0

• Chinese is no longer supported for VSimComposer

#### Attributes Deprecated in Version 7.0

• The attributes GridDenSrc, CoordProdGridPosGen, CoordProdGridDenSrcVW of the ParticleSource block have been deprecated.

• Please use gridPosGen of the xvLoaderEmitter kind instead.
• The attribute numPhysCells of the Grid block has been deprecated.

• Please use numCells instead.

#### Attributes Deprecated in Version 6.0

• The attributes kind=yeeEmField and kind=exp24EmField of the EmField block have been deprecated.

• The attributes kind=block, kind=cosSqPulse, kind=expPeak, kind=gaussianGrad, kind=gaussianLapl, kind=linearRamp, kind=mask, kind=muWaveMode, kind=periodicSTFunc, kind=qFormPolyn, kind=radSymFunc, kind=sawtoothWave, kind=strap and kind=waveguide of the STFunc block have been deprecated.

• Use kind=expression and specify desired functional expression instead
• The attributes kind=smoothWide1D and kind=spaceScalarFieldFuncUpdater of the FieldUpdater block have been deprecated.

• Use kind=smooth1D instead
• The Component sub block of the EmField of kind=funcEmField has been deprecated.

• The components are now set using STFunc blocks with the names E0,E1,E2,B1,B2 and B3.

#### Attributes Deprecated in Version 5.2

• The STFunc block with the name loadProb, which is a sub-block of the ParticleSource block, which is, in turn, a sub-block of the Species block, has been renamed to an STFunc block with the name macroDensFunc.

• The attribute loadInGuardCellFlag of the ParticleSource block with kind=ptclEmitter, which is a sub-block of the Species block, has been renamed loadInGuardCell.

• The attributes kind=speciesTrackTagInternals, kind=speciesTrackTagTraj, kind=speciesTrackTraj, and kind=speciesTracVel have been deprecated

• Use kind=speciesTrackTag instead. We are now only supporting history tracking if the user uses tagged particles.

#### Attributes Deprecated in Version 5.0

• The components attribute in the FieldUpdater blocks of kind=gpuSTFuncUpdater, kind=STFuncUpdater, and kind=unaryFieldOpUpdater has been renamed writeComponents.
• The attributes kind=nonRelESCell and kind=2ndOrderRelBorisCell of the Species block have been deprecated. The same models can be accessed with kind=cell and pusher=nonRelEs for kind=nonRelESCell and kind=cell, pusher=relBoris and stencil=spline2ndOrder for kind=2ndOrderRelBorisCell.

#### Blocks Deprecated in Version 5.0

• Collision
• ImpactCollider
• Ionizer
• Use the Monte-Carlo framework (i.e., the MonteCarloInteractions blocks) in place of using the above deprecated blocks.

#### Attributes Deprecated in Version 4.2

• The attribute function of the BoundaryCondition block and the EmField blocks of kind=yeeStaticElecField, kind=funcEmField, and kind=yeeStaticElecFieldTrillinos, has been replaced with an STFunc block with the name function.
• The UserFunc block now requires specific names. Arbitrary names for this block have been deprecated.

#### Attributes Deprecated in Version 4.0

• The attribute periodicityDirs of the Decomp block has been renamed periodicDirs.
• The attribute indices of the BoundaryCondition and InitialCondition blocks has been replaced with the attribute components.
• The attribute function of the STFunc block has been replaced by the attribute kind.
• The attribute singleEmission of the ParticleSource block, which is a sub-block of the Species block, has been deprecated. The option singleEmission=true has been replaced by the option ptclCountType=noCounting, while the default setting is equivalent to the option singleEmission=false.

#### Attribute Deprecated in Version 2.0

• The attribute xtendUpdate of the FieldUpdater block has been relpaced by the attributes cellsToUpdateAboveDomain and cellsToUpdateBelowDomain.

### VorpalView

• VorpalView, an IDL-based visualization tool, is a deprecated feature as of VSim 6.0.0.