Revision History Prior to Version 9.0.0

Version 8.0.0

• After a Helios simulation is completed, the output file that is opened by default in Hydroplot is now *.exo. Please note that Prism plans to discontinue supporting *.bpf output format.
• Linux users working in a KDE 5 desktop environment will likely experience very slow graphics performance. Use of KDE 5 is discouraged for the time being.
• Implemented support for atomic data generated by FAC in Helios-CR. For more details, see attachment titled "FAC Atomic Data in Prism Codes" in the main documentation.
• Helios-CR will be distributed with a standard set of FAC-generated data. Custom user-generated data are supported as well. The data need to be generated with the latest version of FAC available at GitHub.
• Added support for Big Sur operating system on both Intel- and M1-based computers.
• Updated algorithms and libraries for software activation.
• HydroPLOT:
  • Added options to plot electron and ion specific heat.
  • Some plotting problems for calculations which include CR have been fixed. Those problems included:
    • Ionization Fraction plots (Spatial tab) were getting bad data for CR regions
    • Frequency-dependent plots which also depend on space and time (lower-left pane in Frequency tab), e.g. Radiation energy density, Rosseland opacity, Heating rate, Cooling rate, were getting the wrong number of points.
    • Kinetic energy per ion plots were giving slightly incorrect energy values when plotting from Exodus file.
    • "Radiation power in band" (under Fluxes, in Time tab) were missing data from CR regions, and were plotting incorrect values for non-CR regions, when plotting from Exodus file.
  • Some incorrect axis unit labels have been fixed. Those included:
    • Radiation heating rate, Radiation cooling rate, and Net radiation heating rate (Spatial tab, and also in 2D/3D Contour plots) incorrectly included geometry-dependent length unit dependency (e.g. 1/cm for cylindrical geometry).
    • Fluid kinetic energy (Time tab > Regional properties) was missing geometry-dependent length unit dependency (e.g. 1/cm for cylindrical geometry).
    • For BPF files only, "Plasma internal energy" was actually only the ion component (as opposed to the sum of electron and ion internal energies, which the Exodus files correctly display), so the plot name has been changed to "Ion internal energy" for BPF files.
  • Changed units for "Fluid kinetic energy" (Time tab > Regional properties) from MJ to J.
  • Some issues with "Space/time int. fusion yields" plots have been fixed for spatial line plots as well as for 2D contour plots:
    • For Exodus files, the plots are now integral plots over radius (or zone, or mass), i.e., for a given time, each value is the sum of all values leading up to it in radius.
    • For BPF files, correctly weighted yield values are now plotted.
    • For both Exodus and BPF files, the name of these plots incorrectly said integrated "rates", whereas they are really integrated "yields".

Version 7.5.0

• Ability to specify tabulated thermal conductivities and electrical resistivities is enabled for all users.
• Data for the Tabular Zoning model (set up in Preview Zoning widget) is now stored in the workspace file with more significant figures.
• Added cross-sections for TT fusion reaction. The model is based on tabulated data and a fitting formulas 12-14 from Bosch and Hale, Nuclear Fusion, V. 32, No 4 (1992). Note that the alpha particles and neutrons created in this reaction are NOT added to the particle pool.
• Old PROPACEOS files (format ID < 4, EOSOPA-based formats) are no longer supported in Helios simulations and for visualizing with EOS Opacity Viewer.
• Bug fixes:
  • Fixed crash that occurred when attempting to run simulation in which Tabulated Group Boundaries is selected in Radiation Transport widget, but no group boundaries are entered into the table.
  • Checks for values of zero in the Radiation Source tables are no longer performed.
  • Radiation flux multiplier is no longer ignored when CR calculation starts.
  • If the radiation BC is specified as a time- and photon-energy-dependent table, it is also accounted for when CR model starts.
  • Option to use “Laser as radiation source” now works properly when CR model starts.
• HydroPLOT:
  • In addition to existing option to plot the plasma pressure (electron+ion), it is now possible to plot the electron and the radiation pressure. Note that the radiation pressure plots are only available for the simulation results performed with Helios 7.5.0 or newer.
  • HydroPLOT no longer crashes when requested to plot velocities (node-centered quantity) vs. zone mass.
  • Eliminated potential inconsistencies when plotting photon-energy-dependent quantities in CR simulations where the photon energy grid can change between the time steps.
• EOS and Opacity Viewer
  • The viewer now supports the latest PROPACEOS format (format ID 9) designed for the tables with more than two independent variables.
  • The viewer has redesigned graphical user interface with new features and plot options.

Version 7.4.0

• Electron beam option under Particle Beam tab has been made available to all users.
• Fusion reactions tab has been made available to all Helios CR users.
  Fusion rates for reactions are computed using the local density of deuterium and tritium nuclei and the fuel ion temperature for each volume element. All neutrons are assumed to escape the capsule. Detailed transport of protons and alpha particles is not considered. So the fusion product modeling is applicable to targets that are small and have yields that are sufficiently low that fusion particle transport can be neglected. The following reactions are supported:
  • DD -> nHe3
  • DT -> nHe4
  • DD -> pT
  • DHe3 -> pHe4
  • TT -> nnHe4
• License agreement for Helios was updated. Please read new terms and conditions carefully.
• Enabled support for new sets of Prism atomic data and EOS/opacity tables.
• Users with activated-based licensure may now deactivate their license, in order to use that license seat on a different computer instead. The option is located under License Manager in the Help menu:



A button is available for online deactivation. Alternatively, manual deactivation is available via email contact with Prism.



• Bug fixes:
  • Various issues with tables have been fixed, including unexpected clearing of bad user-entered data when sorting and saving.
  • Fixed issue with tabulated data for initial temperature not being loaded properly to the table when read from an old workspace.
  • Prevent erroneous warning messages to appear when a table with inconsistent data was created but not used.
    
• HydroPLOT:
• Colorbar and legend visibility graphics items can now be hidden and shown with Text menubar options.
• Layer properties editing has been disabled for lineout plots.
• Bug fixes:
  • Fixed crashes when plotting MHD related quantities from an *.exo output file.

Version 7.3.0

• The default EOS was changed from SESAME to PROPACEOS to avoid warnings messages for users that do not utilize SESAME tables.
• Changed defaults for energy and flux of charged particles if electron or ion sources are specified.
• Added check to verify selection of ion species for ion beam model.
• Added checks to verify that users provided tabulated radiation flux data if tabulated radiation BC model was specified.
• On Windows machines, Helios is now correctly installed in 64-bit Program Files folder.
• To better support newer computer hardware, distributions for Windows and Linux are now built with updated compilers and include a new set of dynamic libraries. Average simulation time on Windows machines is reduced by 15%.
• Added capability to specify different initial electron and ion temperatures.
• The first tab (Geometry) was renamed to be "Simulation type". Added controls for requesting non-default initial conditions for electron and ion temperatures, velocities, and magnetic fields models. Relevant fields in "Spatial Grid" tab are only displayed if a corresponding box is checked in Simulation Type. Note that "Magnetic field" control is only enabled in cylindrical geometry.





• Bug fixes:
  • Bug that caused hiding of widgets used to specify materials as DCA materials and setting their composition has been fixed. This occurred when selecting the File | New menu item.
  • Fixed fluid velocities to be interpreted as zone-boundary values rather than zone-centered values. This results in one additional velocity index for the whole grid. Note that, in the case of multiple plasma regions, the velocity value at the boundary between regions will acquire the first velocity in the secondary region, as opposed to the last velocity in the first region. Some simulations that used non-uniform initial velocity distributions may produce slightly different results.
• Fixed bug that prevented simulations with tabulated custom zoning to run in batch mode.
• Fixed inconsistency in particle energy distribution visualization if all alpha particles in fusion reactions were deposited locally.
• To prevent repetitive warning messages from progress monitor while a simulation is running, "New region" button was disabled until the simulation is completed.
  
• HydroPLOT:
• In exo files, spatial distributions of velocities are now correctly displayed.
• In exo files, spatial distributions of ionization fractions are now correctly displayed for simulations that use the same material in different spatial regions.
  

Version 7.2.0

• Added functionality to specify custom stopping powers for alpha particles produced by fusion reactions. This option is not available for all users.
  .
• Added option to specify local deposition model for alpha particles. Absorption probability can vary from 0 to 1, with 0 being free escape, and 1 - complete absorption in a zone where the alphas were introduced to the system.
  .
• New, more robust activation procedure has been implemented. Activation daemons are no longer required. Affected users will receive new activation codes.

• Bug fixes:
• Fixed problem with opening workspaces that contain parameters with absolute values less than 1e-99.
• Disabled ability to start a new calculation from zoning dialog until the previous simulation is complete. Associated crashes are prevented.
• Corrected error message for calculations from a restart file where restart file name is an empty string.
  

Version 7.1.1

• Bug fixes:
• On some Mac computers, recently saved workspace could not be opened because unused opacity multiplier parameter was corrupted.
• "Advanced" button on Radiation source panel is now operational.
• Problem with multiple DCA materials sharing the same element has been resolved.
• In Frequency-dependent Rad BC table, range for allowable values was increased to 1e15.
• Default atomic model for DCA material is now correctly set to Helios CR.
• On Particle beam Help button was not connected to html page.
• For some web browsers, subject index in documentation was not operational.
  
• HydroPLOT:
• Incorrect values for "Regional Properties: Fluid Kinetic Energy" were fixed.
  

Version 7.1.0

• New model for specifying time- and photon-energy-dependent radiation boundary conditions. The data are provided in tabular form. The first column (row 2 through Npe+1) contains photon energies in eV. The first row (columns 2 through Nt+1) contains time in seconds. Npe is the number of photon energy points, and Nt is the number of times. Fluxes for each time and photon energy are in W/cm^2/eV. These tabulated data contain information similar to what was previously available only from VisRad files.
  .
• Laser deposition on inner surfaces is allowed in cylindrical and spherical geometries.
• User-defined volumetric radiation energy sink term can be specified (This feature is in beta form and not available to all users.)

• Bug fixes:
• Fix for non-zero inner radius values being ignored in batch mode.
• Prevent crashes when using laser deposition in cylindrical geometry with void region in the center.
• Fixed units in power table/plot for ions deposition to reflect geometry.
  
• HydroPLOT:
• Plot layers are supported again.
• Significant improvements in graphics redraw speed for computers with low-end video cards.
• Integration Window : Axis tick labels and other graphics items were plotted in wrong place relative to axes (Mac only).
  
  

Version 7.0.0

• Significant changes for output have been implemented. Prism is phasing out support for custom bpf file format. Now, a single netCDF format exo output file is generated that can be used with HydroPLOT as well as input for SPECT3D. The file can also be parsed with standard netCDF utilities to extract quantities of interest.
• External Radiation Source Modeling: Support has been added to include the use of angle-dependent incident radiation fields using files generated by VISRAD.
• Time stamp of simulation completion was added to log file.
• List of users allowed to utilize fusion reaction rates has been expanded.

• Bug fixes:
• When constant opacities are specified, they are no longer overwritten with zero values.
  
• HydroPLOT:
• Empty unit strings are now not added to the Z axis label of contour plots. e.g. the color bar label for mean ion charge now reads "Mean charge" rather than "Mean charge ( )"
• Fixed behavior for plot toolbars.
• Minor improvements to axis labels for several graphs.

Version 6.5.0

• Photon energy resolved opacity data can now be read from OPLIB formatted files and used as an alternative to PROPACEOS data. (This feature is in beta form and not available to all users).
• It now now possible to specify a multiplier to be used for the electron-ion coupling term of the thermal conductivity. This can be found in the Thermal Conductivity part of the Spatial Grid setup in the Advanced section.
• The format of the preferences file has changed and is not backwards compatible with earlier versions of the code. It is advisable to check in preferences ( Edit | Preferences ) to make sure that the default and custom paths for PROPACEOS, Atbase and SESAME data are set correctly. Additionally, if you plan to also run old versions of HELIOS it is suggested to keep a copy of the old preferences file before running the new version of HELIOS. The preferences file is called .heliosrc and can be found in the user home directory. 
• HydroPLOT :
• The dialog box used to adjust the size/position of a plot (by selecting Size/Position from the Graph menu) has been updated to use up/down arrows to alter the values the plot is updated automatically as the buttons are pressed.  Pressing Cancel restores the settings to the original values (i.e. those when the dialog box was first opened).
  
  .

• Superscripts are now used instead of 'e' notation in plots with numbers in Scientific or Engineering notation. For example, what previously appeared as  ' 1.2e23 ' is now rendered as ' 1.2×10²³ ' .
• The lineout tool for taking horizontal and vertical lineouts from 2d contour plots is now much faster; the lineouts from non-regular grid data are now generated correctly.
  

Version 6.4.2

• Options are now available in the Spatial Grid widget to specify the magnetic field used for the initial conditions of each spatial region. (This feature is in beta form and not available to all users.)

Version 6.4.1

• Bug fix:
  • An update was made to fix a crash that could occur on the Mac when running a problem with a single CR region driven by a laser radiation source.
• HydroPLOT:
  • Improvements to graphics:
    • The method used to draw symbols for line plots has been made more efficient, improving the rendering speed.
    • Updates to legends in line plots: The line/symbol properties in the legend are now kept up-to-date with the line/symbol properties of the plotted data; symbols and lines appearing in the legend are rendered at at higher resolution to improve on-screen and print quality.
    • The formatting of numbers that appear in the legend has been improved by reducing the number of signifcant figures when possible.

Version 6.4.0

• Better memory handling of multi-dimensional arrays in the radiation diffusion model has been implemented.
• For CR calculations, there is an improved model for computing line strengths and determining if a bound-bound transition needs be included in the calculation. Line strengths are now based on relative fractions of each atomic species in order to prevent potential problems for mixtures.
• Bug fixes:
  • Updates were made so that filtered radiation data is correctly written to the binary plot file.
  • A bug would cause a radiation source based on lasers to be isotropic, not directional has been fixed.
  • Potential crashes while performing particle tracking in some contracting geometries have been fixed..
  • In CR calculations with a mixture of DCA and non-DCA materials, specific fractions could be computed incorrectly depending on the order of the materials. This could manifest itself in a several ways including incorrect behavior of the frequency meshing algorithm, missing transitions, etc.
• HydroPLOT:
  • Exporting images: Images from the graphics windows can now be exported with a user-specified number of pixels.
    • Options for the exported image size include:
      • Original size
      • Specifying a custom number of pixels for either width or height (the aspect ratio remains fixed)
      • Percentage of original width and height.

    

    • Limitations:
      • The aspect ratio is held fixed (same as that shown in displayed window).
      • Number of pixels: The buffer size, which limits the maximum number of pixels in the image that is exported, is system-dependent. In test cases on a Windows 7 PC, the largest image produced was ~ 20,000 x 12,000 pixels (which is ~ 10 to 20 times larger than images previously exported).
  • Improvements to graphics:
    • The quality of text rendered in various plot windows has been improved. This in particular affects Mac and Linux platforms.
    • Legends and colorbars are now resizable.
    • The ability to reset legends and colorbars to their default position is now available in contour plots and line plots. To reset the position, select the Graph | Reset Legend Position menu item of that plot window.
• Bug fixes:
  • The calculation of albedos and reemitted radiation fluxes has been updated.

Version 6.3.1

• Bug fixes:
  • Materials with different equation of state types but the same opacity file are now correctly treated as seperate materials.
  • When modeling laser deposition as an External Radiation Source, the laser light is now incident normal to the suface, as opposed to being isotropic in angle.

Version 6.3.0

• Support has been added to generate ouput for user-specified radiation bands. The time-dependent radiation power in the band, the time-integrated radiation energy in the band, and the the conversion efficiency (i.e., the ratio of output energy in the band to the laser input energy) are written to the plot file and can be plotted using HydroPLOT. The radiation bands can be defined using either Square or Gaussian bands, or by supplying a Filter Response File. Parameters for the radiation bands are specified in the Output Widget:
  
  
  
  
• The Simple Zoning option now spreads the mass evenly amongst all zones. Previously, the minimum and maximum zones were treated differently.
• If the automated zoning algorithm fails, no graph is shown on the Zoning Widget.
• Bug fixes:
  • Problems on Mac OS X arising from starting HELIOS with an expiring or expired license have been fixed.
  • A bug associated with computing the total region mass for cylindrical or spherical geometries has been fixed.
  • For tabular or analytic mass density values, the calculation of the accumulated mass for a region a non-zero inner radius is now correct.
  • For tabular or analytic temperature or velocity values, the values in regions with a non-zero inner radius are now correct.
  • For regions with constant density, when finding the zone widths there could be a discrepancy between the final radius and the minimum radius of the next region. In particular, this was a problem in cases where a wide region with few zones was followed by a relatively narrow region with many zones. This problem has now been fixed.
  • Units for velocity are now shown correctly in the user interface.
  • All table dialogs are now hidden when the current widget is changed.
  • Deleting selected rows from one- and two-column tables now works.
  • When the Table model is used for zoning, the final zone in each region now has the correct mass density.
    
• HydroPLOT:
  • On the Spatial tab and the Frequency tab, the plot legend shows the plots in order of monotonically increasing time, regardless of the order in which they were selected with the mouse.
  • A data file can be opened by dragging the file to the Data File edit box, clicking in the box and pressing the Enter/Return key.
  • On the Time tab, plots of the radiation power, time-integrated radiation energy and the conversion efficiency for each specified output radiation band have been added.
  • Bug fixes:
    • Problems on Mac OS X arising from starting HydroPLOT with an expiring or expired license have been fixed.
• PROPACEOS Data: HELIOS now supports the use of the updated PROPACEOS Data Library 5.1. Major upgrades to the data tables include:
  • Data computed using PROPACEOS software version 6.3.0, which includes several improvements and bug fixes.
  • Improved use of QEOS for all materials.
  • QEOS results are utilized not only for energies and pressures, but also for average ionization.
  • New model added for computing free-free Gaunt factors: For non-degenerate plasmas, the two-dimensional Chebyshev expansion of Hummer is used. For degenerate plasmas, the Nakagawa model is used. The updated modeling provides better agreement with the TOPS database in benchmark calculations.

Version 6.2.0

• On the Advanced area of the Geometry widget, there is an option to specifiy the position of the minimum edge of the plasma.
  
• On the Advanced area of the Time Controls widget, there is an option to include void regions when the time step is calculated.
  

• On the EOS tab of the Spatial Grid widget, if the equation of state is than of an ideal gas and ionization effects are included, a constant mean charge can be specified.
  
  

• If the plasma density exceeds the maximum in the EOS table, EOS values will be obtained by extrapolotation.
• Bug fixes:
  • For a caculation using a restart file, the first time step used the wrong electron density.
  • A potential problem when calculating radiation rates in parallel has been fixed.
• HydroPLOT:
  • There is a new implementation of text boxes and legends for the plots.
• PROPACEOS data:
  • A new set of PROPACEOS tables (v. 5.0.0) has been generated with PROPACEOS v. 6.3.0 and format ID 8. The tables are available for all pure elements with 1 ≤ Z ≤ 36, Hydrogen isotopes, and several mixtures.

    All tables have been computed using the following parameters

    • Temperature grid for EOS: 36 points from 10^-2 to 10⁵ eV.
    • Temperature grid for opacity: 36 points from 10^-2 to 10⁵ eV.
    • Density grid for EOS: 91 points from 10¹⁶ to 10²⁵ ions/cm³.
    • Density grid for opacity: 46 points from 10¹⁶ to 10²⁵ ions/cm³.
    • Opacity group structure: 500 groups from 10^-1 to 10⁵ eV.

    For Hydrogen, its isotopes and mixtures with Ar, the upper density range has been extended to 10²⁶ ions/cm³.

    Major differences with the previous distribution (v. 4.2.0) include:

    • Consistent use of QEOS for all materials.
    • QEOS corrections are applied not only to energies and pressures, but also to the average ionization.
    • Improved consistency in computing photoionization by eliminating potential double-counting for some transitions.

  An example EOS is shown below for Co.:

  

Version 6.1.1

• Bug fixes:
  • Material regions parameters: the Duplicate and Delete regions buttons work correctly.
  • Atomic elements parameters: the Delete button is no longer active if there are no elements.

Version 6.1.0

• An option has been added to model an external radiation source as having normal incidence to a planar slab (such as occurs when a planar target is located far from an external radiation source). Prior to this, external radiation sources were always assumed to be Lambertian. To use this option, select the Incident Radiation Normal to Surface button under the Advanced parameters of the Radiation Source parameters widget. Using this option requires that the Multiangle radiation transport model be used.

• An option to apply a multiplier to the artificial viscosity has been added. See the Advanced options in the Hydro panel.

• A vertical splitter bar has been added to the Preview Zoning widget.
• Bug fixes:
• Problem of running with materials using custom (i.e, non-Library) equation of state or opacity data files has been fixed.
• Additional checks for negative zone widths have been added to avoid a crash that could occur if attempts to fix the problem failed.
• Bugs associated with cycle-based output have been fixed.
• Bugs associated with writing and reading a restart file have been fixed.

• HydroPLOT:
• Bug fixes:
  • Correct data is now shown in plots of plasma pressure vs. time for a specified volume element

Version 6.0.0

• Support has been added for 64-bit Windows and 64-bit Linux systems.
• An option to use parallel processing for the collisional-radiative (CR) portion of simulations has been added. Parallelization is performed over frequency points when computing opacities and updating radiative rate integrals. This option is selected on the Simulations tab of the Preferences dialog. The magnitude of the speedup obtained with parallel processing will vary depending on the nature of the simulation, the operating system being used and the number of processors available.
• NetCDF plot files can be written for CR and non-CR calculations. For a CR calculation, frequency dependent data is not written after CR has started. (Note that NetCDF files cannot be opened in HydroPLOT).
• When the ideal gas option is selected for the equation of state, the ideal gas "gamma" (C_p/C_v), can be specified. In addition, ionization effects on the equation of state can be included.

• Bug fixes:
  • Fixed bug associated with running multi-threaded simulations when parallelizing over frequency groups and the Typical frequency group setup is not used.
  • Fixed location of preferences file on Windows platforms running Vista OS or later.
  • Fixed loss of text in various combo boxes (atomic model, initial density value, EOS file, opacity file, laser incident region).
  • Data entered in the custom zoning table is saved correctly and duplicate values are removed.
  • The zone width radio button is correctly set on first viewing the zoning dialog.
  • Identical zone widths are used for interactive and batch runs.
  • The external radiation source is now included correctly in calculations with cylindrical or spherical geometry.
  • A problem occurring on some platforms in which the bound-bound structure was omitted in CR calculations was fixed.
• HydroPLOT:
  • Plot windows can be closed by pressing the 'Esc' key.
• Bug fixes:
  • Fixed location of preferences file on Windows platforms running Vista OS or later.
  • Plot preferences are restored correctly.
  • A problem with Version 5.2.0 where the populations from a CR calculation could not be read has been fixed.

Version 5.3.0

• Updated compilers are now used for Windows versions of HELIOS. In many cases, this results in a reduction in CPU time required for calculations.
• The (3rd party) user interface software used by HELIOS had been updated, resulting in a slightly different style for the widgets.
• Multi-threading support for simulations has been added, which can produce significant speed-ups when running HELIOS on multi-core desktop computers. The multi-threading affects the calculations of multi-group radiation transport when either the Diffusion or Multiangle model is used. To set parameters for performing multi-threaded calculations, go to the Simulations tab in the Preferences Dialog (invoked with Edit | Preferences).
• Ion beam modeling: Energy deposition by energetic ions into the target plasma is now available in HELIOS-CR. The energy deposition rate is computed using the ion deposition model of Mehlhorn (1981).
• Laser beam modeling:
  • Support added for performing simulations with up to 3 laser beams. The characteristics (wavelength, power, etc.) of each beam can be individually adjusted.
  • For cylindrical or spherical geometries, the focal position, half cone angle and the number of angles can be entered. In addition, the number of points in the focal plane, the spatial profile, and the spot radius can be specified.

  

  .

• For HELIOS-CR calculations, a temperature floor of 0.1 eV is applied when the atomic populations are computed to avoid numerical problems.
• An option to use parallel processing for the radiation transport segment of a non-CR calculation has been added. This is selected on the Simulations tab of the Preferences dialog. The magnitude of the speedup obtained with parallel processing will vary depending on the nature of the simulation, the operating system being used and the number of processors available.
• On Linux and Mac systems, Helios will search for versions of PROPACEOS and ATBASE data, and AtomicModelBuilder that are newer than those currently listed in the preferences and offer the option to use them as defaults. The seach assumes that the default directory scheme is used.
• Bug fixes:
  • The bound electron contribution to the stopping of energetic ions in plasmas has been added. This term had been omitted in versions 4.5 - 5.2.
  • For HELIOS-CR calculations, a problem producing inaccurate photoionization cross-sections due to inconsistent configuration strings has been fixed.
  • HydroPLOT and AtomicModelBuilder launch correctly on the Mac.
• HydroPLOT:
  • Plots of region boundary heat fluxes vs. time for electron and ion thermal conduction are now available.
  • Contour plots: the last used settings for each plot type are stored and will be reused when the plot type is re-selected.

Version 5.2.0

• EXODUS file output:
  • The ion temperature data is written to the exodus file for use in post-processing by SPECT3D.
  • The fluid velocity data is written to the exodus file for use in computing Doppler shift effects when post-processing by SPECT3D.
• Bug fixes:
  • Spatial Grid Widget:
    • Problem associated with moving Regions up and down in regions list has been fixed.
    • Problem associated with initializing Fluid Velocity using Analytic method has been fixed.
    • Mis-labeling of Variable Temperature Table dialog has been fixed.
    • Unneeded checks on Variable Temperature, Density, and Velocity table values have been fixed.
  • Fixed problems with incorrectly plotted values for the laser radiation exiting the plasma in spherical geometry.
• Zoning Table: Cell editing has been fixed.
• Radiation Source Widget:
  • Fixed inconsistent activation of the Advanced button.
• View menu:
  • Progress Monitor menu item works correctly.
• HydroPLOT:
  • Plots added: laser power incident at boundary
  • Bug fixes:
    • HydroPLOT: On the Mac, the message box for a soon to expire license no longer blocks the initial open file dialog .
    • Fixed problem where spatial plots with data on the zone boundaries had the wrong number of points when cycled through time

Version 5.1.1

• Bug fixes:
  • Problem associated with initializing region properties using a Variable temperature or Variable velocity with multiple Spatial Regions has been fixed.
  • Message about bad value for a Constant temperature is no longer shown if Constant temperature model not used.

Version 5.1.0

• The temperature and velocity for each spatial region can now be initialized to have a user-specified spatial distribution. (Previously this option was supported only for density.) Both analytic expressions and table interpolation are supported. Parameters are entered on the Initial Conditions tab of the Spatial Grid widget. Table values can be imported from an ascii file.

• The option to initialize atomic level populations to a non-LTE state when running HELIOS-CR in collisional-radiative mode has been added. (Previously, levels populations were initialized to LTE.) This option is selected in the Initialization tab of the Atomic Processes widget. When selecting "Non-LTE (thin)", both photoionization and photoexcitation are neglected in the initialization step.

• User Preferences: The use and saving of existing Preferences data has been updated.
• Bug fixes:
  • HydroPLOT: Bug associated with displaying atomic levels has been fixed.

Version 5.0.1

• Both HELIOS and HydroPLOT have been upgraded to utilize a newer version of the user interface software library.
• An option to write out the populations of the atomic energy levels for a CR calculation has been added.
• HydroPLOT: Spatial and temporal plots of the atomic energy level populations are available.
• Bug fixes:
  • HydroPLOT: The position at which a specified laser attenuation occurs was correct for the overall zone, but incorrect within a zone. This has been fixed.

Version 5.0.0

• A new angle dependent radiation boundary condition has been implemented for laser driven problems where the laser energy is treated as an external radiation boundary condition. The model applies only for planar geometry and mutli-angle radiation transport. The laser beam is assumed to be normal to the surface with a non-zero radiation field in a narrow angle around the normal.
• For CR modeling, upgrades were made to substantially reduce memory requirements for problems involving complex atomic models (i.e., with many atomic levels and transitions). The effect on CPU time is minimal.
• HydroPLOT: Additional laser related plots are available (for planar geometry only)
  • Spatial dependence of laser power (line and contour plots)
  • Time dependence of the laser power relative to the incident power at the boundary.
• The multi-angle radiation transport model has been modified to better treat simulations with a rapidly varying external radiation field (e.g. a short-pulse laser).
• All graphs now have fonts that scale with the size of the graph.
• There is a greater choice of plot symbols for line plots.
• Bug fixes:
  • Fix to prevent double counting of the radiation pressure at the boundary when incident laser beam is modeled as an external radiation field..
  • The 'BadContext' messages on Linux should no longer show.

Version 4.4.0

• The algorithms used to describe the electron-ion coupling term at low temperatures have been improved. Unphysical behaviors that were observed at temperatures below 1 eV no longer occur.
• Algorithms describing the deposition of laser energy in spherical and cylindrical geometries have been improved to give smoother deposition profiles, especially for plasmas with densities less than critical and near the center zones.
• The number of significant figures that can be used to specify the output times for the plot file and the log file has been increased to accommodate the use of short pulse lasers.
• HydroPLOT: An option has been added on the frequency tab to apply an instrumental resolution to the calculated frequency spectra.
• Bug fixes:
  • In the electrical resistivity calculation, the Coulomb logarithm is correctly computed using temperatures and densities of the electrons, not the ions.

Version 4.3.0

• New options on the advanced tab of the Laser settings:
  • Bound-bound and bound free transitions can be included when calculating laser absorption.
• The minimum value of the mean charge used for free-free laser absorption can be user set. The default value is 0.1

• Bound-bound and bound-free contributions to the laser absorption coefficient are computed for each material based on the opacity tables (before regrouping). The contributions are added to the existing free-free absorption coefficient.
• HydroPLOT: Plots of the transmitted laser power have been added to the time tab.
• Bug fixes:
• The time dependent laser beam power is now calculated correctly when the total energy in the beam is specified.
• HydroPLOT: Results from large files, where only a selection of the time steps are used, should now display without crashing.

Version 4.2.0

• Checks on the maximum time change between calculation steps can be turned off.
• The restart option is available for non-CR calculations.
• An incident laser can be used in cylindrical geometry.
• All zone boundaries within a region can be user specified.
• The variable in the analytic density expression can be 'x' or 'r'.
• The zone widths at the extremes of the plasma or at the extremes of each region can be set by the user.
• More options are offered for fusion reactions (if available).
• The time grid for a Gaussian laser pulse always contains a point at the peak of the Gaussian.
• Changes have been made to the time step controller to ensure that a laser pulse with a width much less than the time step is included in the simulation.
• The laser absorption coefficient is adjusted to be continuous when the mean ionization in the plasma is very low.
• Upgrades relevant to HELIOS-CR (Collisional-Radiative modules):
  • An improved algorithm for non-local calculations reduces the number of iterations required giving a significant speed up.
  • An improved algorithm for the photon energy mesh used when computing non-local radiation dependent rates gives a faster calculation.
  • The high energy wing of a line does not extend beyond a corresponding bound-free edge. This prevents potential double-counting of emissivity/opacity close to the edge, and may improve computational efficiency.
• HydroPLOT: new plots of laser quantities and ion beam quantities.
• Bug fixes:
  • Integers on the form n e^m are accepted.
  • The floating point precision in the zone boundaries table has been increased.
  • Clicking the close box on the progress monitor no longer aborts the simulation.

Version 4.1.0

• When running interactively, any error messages produced by the physics library are shown in a message box.
• Laser:
  • In calculating laser deposition for cylindrical and spherical geometries, the ray angles are adjusted at each time step, resulting in a smoother deposition profile.
  • The laser beam power profile can be specified to be a Gaussian characterized by either the peak power or the total energy::

  

• If a table is used to set the power, a multiplier may be applied to the table values:
• The density for each region can be specified using an analytic expression:

• The maximum number of cycles has been increased from 1e6 to 1e8.
• HydroPLOT: A save button has been added to the toolbar.
• HydroPLOT: On the contour plot parameters window, the wavelength units now include nm.
• Bug fixes:
  • For the variable density table option, the zoning failed if there were more density points than zones.
  • If a batch run fails to start, the application exits.
  • In the event of poor mass matching, a message is written to the console in batch mode, not to a message box.
  • HydroPLOT: The ionization fractions for DCA materials are shown correctly when CR is turned on.
  • HydroPLOT: Contour plots of the radiation loss with the frequency in Angstroms no longer cause a crash.
  • HydroPLOT: Line and contour plots of the time integrated power loss now show correctly for CR calculations.

Version 4.0.0

• HydroPLOT has been upgraded to support copying graphs directly into Microsoft Office applications (e.g., MS Word and PowerPoint). The upgraded capability not only provides more convenience (by eliminating the intermediate steps of generating image files, such as *.jpg files), it also provides for higher quality transfer with improved resolution.
  • At present, support is provided for line plots only on Windows PC platforms.
  • Graphs can be copied using the Edit | Copy Graph menu item on the plot window menu, and then pasted into Microsoft Office applications (and other applications such as WordPad or NotePad). For more information, see Copying Graphs into MS Office Applications.

  

   

• HydroPLOT now supports the use of workspaces. This allows all plots being viewed by HydroPLOT to be saved and re-opened with the same plot settings. For the plot windows being displayed, plot data can be saved to a HydroPLOT workspace (*.hyw) file. When opening the HydroPLOT workspace, the plot windows will be restored. For more information, see HydroPLOT Workspaces.
• HydroPLOT now supports the use of Graph Templates. Graph settings can be saved to a Template file which can be used when plotting the same quantity in the future. The template file can also be applied to other plot quantities. For more information, see HydroPLOT Templates.

• A Restart capability has been added, which is suitable for running long-CPU simulations (CR version only). The option to write a restart file and set the times at which it is written is on the Output panel:

The option to use a restart file and select the time at which to restart is on the Advanced section of the Time Controls panel:

• HELIOS now supports initial density distributions within a single Spatial Region that are non-uniform. There are now 3 options for specifying the initial density distribution:
  • Mass Density - constant: Mass density is spatially uniform (previously, the only option)
  • Mass Density - variable: Mass density in a given Spatial Region is variable
  • Gas Pressure @ 298K: Mass density is spatially uniform, and is obtained from the specified pressure using the ideal gas law and an assumed temperature of 298K:
    

  
  

  
  
  

• HELIOS now supports the use of PROPACEOS files with a format ID = 6 and binary PROPACEOS files. It also supports PROPACEOS files that contain equation-of-state data only (i.e., no opacity data).
• For laser deposition modeling, users can specify the fraction of laser energy that is reflected from the critical surface. (This was previously assumed to be zero.) The setting is on the Advanced section of the Laser Source panel:

• Thermal conductivity parameters: There is an option to turn conductivity flux limiters on or off, and change the limiter value. The settings are on the Advanced section of the Th. Conductivity tab on the Spatial Grid panel:

• If there is no preferences file, warnings are given if the environment variables are not set (Windows PC platforms only). The default directory paths are shown, with a warning is given if the default directories do not exist.
• Upgrades relevant to HELIOS-CR (Collisional-Radiative modules):
  • Computational efficiency:
    • Upgrades were made to photoionization setup routines that result in significant improvements in efficiency (~ factor of 5 in test case).
    • Arrays used to track transition indices upgraded to reduce memory requirements (results in ~10x memory reduction in large-scale calculations).
    • Calculation of collapsed transition parameters has been optimized resulting in significant reduction of application initialization time for mid-Z elements.
    • Calculation of natural line width parameters has been optimized resulting in significant reduction of applications initialization time.
  • Improved line profiles for inner-shell satellite line (Kα, Kβ, Kγ, ...) transitions in L-shell ions (Be- through F-like) based on He-like scaling and adjusted to match R. Mancini's calculations for N-, O-, and F-like Al Kα lines.
  • Plasma coupling parameter gamma is used as a criterion to switch to LTE population kinetics at high densities to prevent convergence problems due to excessive continuum lowering.
  • Automated frequency grid generator: Line frequency point distribution parameters have been revised in order to increase the accuracy of results when a minimum number of frequency-points-per-line are used.
  • Threshold for including bound-free transitions, based on atomic level populations was adjusted to include more transitions.
  • Added support for new atomic model file formats. Improved consistency for level configuration and term accounting.
  • Added emissivity correction for inner-shell photoionization transitions in which upper states are not explicitly included in atomic model.
  • Added detailed balancing correction to effective dielectronic recombination rate coefficient when transitions involving autoionization states are not treated in detail.
  • Upgrades were added to improve convergence of non-LTE populations at high densities.
• Bug fixes:
  • Problem fixed in radiation modeling when running multi-group radiation transport for a two temperature plasma.
  • Problem fixed for potential problems in parallel calculations using tabulated opacities with a non-square opacity grid.
  • Problem fixed for underflows associated with excessively small external radiation source temperatures.
  • Problem fixed for occasional binary characters written to a log file.

Version 3.5.2

• Added capability to utilize SESAME-formatted electrical resistivity tables.
• User can now specify percentage of laser power reflected at the critical surface.
• Added flux limiter for electron thermal conduction modeling. Flux limiter can be adjusted by the user.
• PROPACEOS data:
  • HELIOS now reads PROPACEOS data file formats up for format ID #6.
  • PROPACEOS 3.0 data includes QEOS modeling for strongly coupled regime (i.e., near solid density and low temperatures).
• See Hydroplot updates.

Version 3.5.0

• Added capability to utilize SESAME-formatted thermal conductivity tables (#603 tables).
• For HELIOS-CR:
  • Physics library:
    • Computational efficiency: upgrades were made to non-DCA opacity calculation routines that result in significant improvements in efficiency.
  • ATBASE 5.1
    • Dielectronic recombination rate coefficients have been upgraded to better model rates for L-shell (Be-like to Ne-like) ions.
    • Electron impact excitation cross sections computed from distorted wave calculations are scaled at near-threshold energies consistent with published close-coupling results.
    • All autoionization energy levels for He-like and Li-like satellites are treated explicitly.
    • A flag has been added to identify transitions present in the NIST database.
    • A new configuration string that contains information about parent terms has been added.

Version 3.4.0

• In MHD simulations, an applied voltage can now be specified as input. The discharge current is determined by solving the circuit equation. To simulate z-pinches with a return current can, users should set the outer boundary (Rmax) as fixed (in "Hydro tab"), and the outermost (vacuum) region can be set to a low density. Algorithms for tallying conservation of energy checks have been updated.
• Progress monitor is now set up to update every hydro cycle when collisional-radiative mode is on.
• Artificial viscosity is now written to both the binary plot file and NETCDF plot file.
• The spatial grid for the plasma can be imported from a file.
• Frequency group boundaries for radiation transport can be set by the user.
• The opacity can be set to be constant below a specified temperature and photon energy. The opacity can be either a specified constant or the value obtained from the opacity file at the specified temperature.
• See Hydroplot updates.
• Bug fixes:
  • Fixed crash that occurred when the 'Update Zoning' button was clicked with zero regions.
  • Fixed loop optimization problem on Linux.

Version 3.3.0

• User option to set the opacity to a constant value.
• Updated to use the new atm file structure.
• MHD modeling is available to all users. The MHD model is presently limited to discharge current model.
• Plot NETCDF files now have suffixes hna and hnb (previously hn1 and hn2).
• See Hydroplot updates.

Version 3.2.1

• Void cells are now included when updating time step controls.
• Void cells now turn into plasma cells when a threshhold density (r = 10^-6 g/cm³) is reached.
• Checks have been added to make sure EOS tables have monotonically increasing temperature and density grids.
• See Hydroplot updates.
• Bug fixes:
  • Problem fixed in radiation modeling when running multi-group radiation transport for 2-T plasma.
  • Problem associated with inadvertant reporting of exceptions during time step reductions has been fixed.

Version 3.2.0

• A paper describing models in HELIOS has been added to the online documentation (in Appendix).
• Time step control information (criterion and zone) has been added to the progress monitor.
• Added support for user-specified thermal conductivity multiplier to region parameters.
• One or both boundaries (R_min and R_max in planar, or R_max in cylindrical and spherical geometry) of the plasma can be kept stationary instead of being allowed to expand freely.
• Support for "void" regions added. In void regions, no Joule heating or laser energy deposition occurs, and the B-field does not contribute to the momentum equation in void cells. Void cells are also ignored in updating time step controls.
• Option to write plot data as NETCDF files - one for data written at all times and one for frequency data. Writing NETCDF data for collisional-radiative (CR) variables in HELIOS-CR calculations not yet supported.
• See Hydroplot updates.
• Bug fixes:
  • Force rezoning when a region is added or deleted.

Version 3.1.0

• A sesame file containing table 301 can be used.
• See Hydroplot updates.
• Bug fixes:
  • The 'Hide' button on the progress window now hides the window instead of leading to the abort dialog.
  • In energy accounting, kinetic energy is now computed including the first zone.
  • Fixed a crash that occurred when two regions used the same prp file.
  • Fixed a crash that occurred if a two temperature simulation was chosen and the sesame file only contained one temperature tables.

Version 3.0.3

• See Hydroplot updates.
• Bug fixes:
  • The tabs were shown on the Spatial Grid widget are now correct.
  • A message box no longer shows during a batch run when a large amount of output is being generated.

Version 3.0.0

• Runs in batch.
  • Helios.exe <workspace_file>
  • For the GUI application:
    • No parameters: launches the GUI application.
    • <workspace_file> opens <workspace_file> in the GUI application.
  • For the batch application:
    • -b Run in batch mode.
    • -i WORKSPACE Input workspace file (required).
    • -o RUNNAME Name for the output files (defaults to workspace name).
    • -d OUTPUT_DIR The directory for the output files (defaults to workspace directory).
    • -x Overwrite existing data files.
    • -h Prints a help message.
• The number of times a warning is printed to the log file is now limited.
• Added user set value for the minumum oscillator strength transitions to include in the photoabsorption grid (non LTE only).
• See Hydroplot updates.
• Bug fixes:
  • Fixed problem associated with automatic frequency grid generation; relevant to inline collisional-radiative calculations only.
  • Memory leak fixed for HELIOS-CR; relevant to inline collisional-radiative calculations only.
  • Fixed problem that can occur when 2-T option is used and density for a volume element drops below EOS table values.
  • Fixed problem that occurred when the same material was present in both a DCA and a non-DCA region.

Version 2.1.1

• Additional output for displaying energetics has been added to HELIOS and HydroPLOT.
• See Hydroplot updates.
• Bug fixes:
  • Flux multiplier is now applied to 1-T external radiation sources (previously, it was applied only to VISRAD radiation sources).

Version 2.1.0

• Uses Prism Plot Library 3.0.0.
• HELIOS-CR uses Prism SPECT3D Physics Library 4.1.0.
• Seseame files: reads 301 tables for one-temperature calcualations if 303 and 304 tables are not available.
• Radiation Source, advanced settings: input a multiplier for the flux.
• Atomic Processes, advanced settings: input number of continuum and line points for the photoionization grid.
• Preferences: set workspace directory preference.
• See Hydroplot updates.

Version 2.0.0

• HELIOS uses Prism Plot Library 2.1.0.
• HELIOS-CR uses Prism SPECT3D Physics Library 4.0.0.
• Capability added to view equation of state (SESAME and PROPACEOS) and multigroup opacity (PROPACEOS) data directly from HELIOS materials setup widget.
• This distribution includes a new set of PrOpacEOS files.
• Time step controls:
  • Max. allowed fractional change for T_e, T_i, E_R, V, and Courant adjusted downward from 0.5 to 0.25.
• Graphics:
  • Can now plot time-dependent radiation fluxes at material region boundaries.
  • Can now plot time-dependent net radiation cooling rates for each material region.
• Documentation:
  • New benchmark simulations have been added to Appendices:
    • Al Shock Breakout Simulation
    • Radiation-Driven Capsule Implosion Simulation
    • Ar-Doped Capsule Implosion with Non-LTE Atomic Kinetics
• Miscellaneous upgrades and bug fixes:
  • Plasma conduction boundary condition default to reflective boundaries for ions and electrons.
  • Support added for single-frequency-group radiation simulations.
  • Support use of PROPACEOS files with Format ID = 3.
  • Exception flags reset after uncompleted simulation.
• See Hydroplot updates.

Version 1.3.0

• HELIOS-CR uses Prism Physics Library 4.0.0 and enhanced Prism Plot Library.
• Enhancements:
  • Improved algorithms for short-characteristics in planar geometry.
  • Improved algorithms for diffusion (new boundary conditions and flux limiters are implemented). Default flux limiter is Larsen's with n=2.
• Several minor fixes.
• This distribution includes a new set of PrOpacEOS files.
• See Hydroplot updates.

Version 1.2.0

• Graphics
  • Helios now utilizes the new improved Prism plot library.
• Laser deposition
  • For spherical geometries, Helios now utilizes a ray tracing algorithm, that allows for more realistic laser deposition modeling within a 1D approximation.
  • Improved algorithms for computing the Coulomb logarithm.
• Lagrangian zoning
  • The default zone widths for R(min) and R(max) are now based on the mean zone widths of the corresponding regions.
• Several minor bug fixes
• This distribution includes a new set of PrOpacEOS files.

Version 1.1.0

• Conductivities
  • Previously, only Spitzer conductivity model was supported. Two other conductivity models have been added:
    • Constant conductivity for a region
    • Spitzer / Constant conductivity hybrid model, where constant conductivity is used in solid regime.
  • Conductivity tab has been added to Spatial Grid setup widget for selecting model and entering parameters.
• Equation of State (EOS)
  • For SESAME EOS, modifications to table properties at low-temperature are no longer made.
  • Birational interpolation model added.
• Progress Monitor Graphics
  • Pressures are now displayed in GPa.
  • Fluid velocities are now displayed in km/sec.
• Several minor bug fixes