MoltresJsonMaterial

Declares material properties based on names and values prescribed by input parameters.

Overview

This material class preloads and interpolates JSON-based group constant data provided at various temperature. MoltresJsonMaterial declares the interpolated group constant data as material properties which may be accessed by the neutron diffusion kernels to model a reactor and simulate temperature reactivity feedback. Refer to the "Materials Block" subsection of the Tutorial 2a for more information.

Table 1: Relevant group constants for neutron energy group $var element = document.getElementById("moose-equation-f8987891-9d00-429e-ae12-14a746d4d27f");katex.render("g", element, {displayMode:false,throwOnError:false});$ or delayed neutron precursor group $var element = document.getElementById("moose-equation-7687ee80-b87b-4892-ac69-0ceb97a981b2");katex.render("i", element, {displayMode:false,throwOnError:false});$

Group constant	Formula	Label
Macroscopic fission cross section	$var element = document.getElementById("moose-equation-7ac784e3-fec4-4725-b031-45285e72d148");katex.render("\\Sigma_{f,g}", element, {displayMode:false,throwOnError:false});$	FISSXS
Macroscopic removal cross section	$var element = document.getElementById("moose-equation-cf9a1ff3-e27e-4245-a5d7-2c6676b0198f");katex.render("\\Sigma_{r,g}", element, {displayMode:false,throwOnError:false});$	REMXS
Macroscopic scattering cross section	$var element = document.getElementById("moose-equation-7ddbe25f-dac4-45a8-a0d2-a79b94f0168f");katex.render("\\Sigma_s^{g'\\rightarrow g}", element, {displayMode:false,throwOnError:false});$	GTRANSFXS
Neutron diffusion coefficient	$var element = document.getElementById("moose-equation-b62ebd9f-3a11-46f2-bca8-355aed1bc298");katex.render("D_g", element, {displayMode:false,throwOnError:false});$	DIFFCOEF
Inverse neutron velocity	$var element = document.getElementById("moose-equation-0df14395-bbbe-45b6-a606-ed3326ebfee9");katex.render("\\frac{1}{v_g}", element, {displayMode:false,throwOnError:false});$	RECIPVEL
Fission neutron spectrum (total)	$var element = document.getElementById("moose-equation-7443d5d4-84b0-466a-b1cb-1942d8294b67");katex.render("\\chi_{t,g}", element, {displayMode:false,throwOnError:false});$	CHI_T
Fission neutron spectrum (prompt)	$var element = document.getElementById("moose-equation-d25aad8d-be3b-414e-bc38-d07b745d87f7");katex.render("\\chi_{p,g}", element, {displayMode:false,throwOnError:false});$	CHI_P
Fission neutron spectrum (delayed)	$var element = document.getElementById("moose-equation-55c9e390-46e6-496f-a7f1-35a6a900b9c8");katex.render("\\chi_{d,g}", element, {displayMode:false,throwOnError:false});$	CHI_D
Effective delayed neutron fraction	$var element = document.getElementById("moose-equation-8f5bc907-82e8-4a66-a505-41bc7086a2a4");katex.render("\\beta_{eff}", element, {displayMode:false,throwOnError:false});$	BETA_EFF
Delayed neutron precursor decay constant	$var element = document.getElementById("moose-equation-a52db868-5d2c-4b60-b204-8b5b154a3573");katex.render("\\lambda_i", element, {displayMode:false,throwOnError:false});$	DECAY_CONSTANT

Example Input File Syntax

Input Parameters

base_fileThe file containing macroscopic XS.
C++ Type:std::string
Controllable:No
Description:The file containing macroscopic XS.
interp_typeThe type of interpolation to perform.
C++ Type:MooseEnum
Options:bicubic, spline, monotone_cubic, linear, none, least_squares
Controllable:No
Description:The type of interpolation to perform.
material_keyThe file key where the macroscopic XS can be found.
C++ Type:std::string
Controllable:No
Description:The file key where the macroscopic XS can be found.
num_groupsThe number of groups the energy spectrum is divided into.
C++ Type:unsigned int
Controllable:No
Description:The number of groups the energy spectrum is divided into.
num_precursor_groupsThe number of delayed neutron precursor groups.
C++ Type:unsigned int
Controllable:No
Description:The number of delayed neutron precursor groups.
prop_namesThe names of the properties this material will have
C++ Type:std::vector<std::string>
Controllable:No
Description:The names of the properties this material will have
prop_valuesThe values associated with the named properties
C++ Type:std::vector<double>
Controllable:Yes
Description:The values associated with the named properties

Required Parameters

blockThe list of blocks (ids or names) that this object will be applied
C++ Type:std::vector<SubdomainName>
Controllable:No
Description:The list of blocks (ids or names) that this object will be applied
boundaryThe list of boundaries (ids or names) from the mesh where this object applies
C++ Type:std::vector<BoundaryName>
Controllable:No
Description:The list of boundaries (ids or names) from the mesh where this object applies
computeTrueWhen false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.
Default:True
C++ Type:bool
Controllable:No
Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.
constant_onNONEWhen ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped
Default:NONE
C++ Type:MooseEnum
Options:NONE, ELEMENT, SUBDOMAIN
Controllable:No
Description:When ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped
declare_suffixAn optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.
C++ Type:MaterialPropertyName
Controllable:No
Description:An optional suffix parameter that can be appended to any declared properties. The suffix will be prepended with a '_' character.
group_constantsREMXS FISSXS NSF FISSE DIFFCOEF RECIPVEL CHI_T CHI_P CHI_D GTRANSFXS BETA_EFF DECAY_CONSTANT Group constants to be determined.
Default:REMXS FISSXS NSF FISSE DIFFCOEF RECIPVEL CHI_T CHI_P CHI_D GTRANSFXS BETA_EFF DECAY_CONSTANT
C++ Type:std::vector<std::string>
Controllable:No
Description:Group constants to be determined.
prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
C++ Type:MaterialPropertyName
Controllable:No
Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
sss2_inputTrueWhether serpent 2 was used to generate the input files.
Default:True
C++ Type:bool
Controllable:No
Description:Whether serpent 2 was used to generate the input files.
temperature937.0The temperature field for determining group constants.
Default:937.0
C++ Type:std::vector<VariableName>
Controllable:No
Description:The temperature field for determining group constants.
use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.
Default:False
C++ Type:bool
Controllable:No
Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:Yes
Description:Set the enabled status of the MooseObject.
implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Controllable:No
Description:Determines whether this object is calculated using an implicit or explicit form
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Controllable:No
Description:The seed for the master random number generator
use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Advanced Parameters

output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)
C++ Type:std::vector<std::string>
Controllable:No
Description:List of material properties, from this material, to output (outputs must also be defined to an output type)
outputsnone Vector of output names where you would like to restrict the output of variables(s) associated with this object
Default:none
C++ Type:std::vector<OutputName>
Controllable:No
Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object

Outputs Parameters

(tutorial/eigenvalue/nts-action.i)

[GlobalParams]
  num_groups = 2
  num_precursor_groups = 6
  use_exp_form = false
  group_fluxes = 'group1 group2'
  pre_concs = 'pre1 pre2 pre3 pre4 pre5 pre6'
  temperature = 900
  sss2_input = true
  account_delayed = true
[]

[Mesh]
  coord_type = RZ
  [mesh]
    type = FileMeshGenerator
    file = 'mesh.e'
  []
[]

[Problem]
  type = EigenProblem
  bx_norm = bnorm
[]

[Nt]
  var_name_base = group
  vacuum_boundaries = 'fuel_bottom mod_bottom right fuel_top mod_top'
  pre_blocks = '0'
  create_temperature_var = false
  eigen = true
[]

[Precursors]
  [pres]
    var_name_base = pre
    family = MONOMIAL
    order = CONSTANT
    block = 0
    outlet_boundaries = 'fuel_top'
    constant_velocity_values = true
    u_def = 0
    v_def = 18.085
    w_def = 0
    nt_exp_form = false
    loop_precursors = false
    transient = false
    eigen = true
  []
[]

[Materials]
  [fuel]
    type = MoltresJsonMaterial
    block = '0'
    base_file = 'xsdata.json'
    material_key = 'fuel'
    interp_type = LINEAR
    prop_names = ''
    prop_values = ''
  []
  [graphite]
    type = MoltresJsonMaterial
    block = '1'
    base_file = 'xsdata.json'
    material_key = 'graphite'
    interp_type = LINEAR
    prop_names = ''
    prop_values = ''
  []
[]

[Executioner]
  type = Eigenvalue
  initial_eigenvalue = 1
  solve_type = 'PJFNK'
  petsc_options = '-snes_converged_reason -ksp_converged_reason -snes_linesearch_monitor'
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'

  automatic_scaling = true
  compute_scaling_once = false
  resid_vs_jac_scaling_param = 0.1

  line_search = none
[]

[Postprocessors]
  [k_eff]
    type = VectorPostprocessorComponent
    index = 0
    vectorpostprocessor = k_vpp
    vector_name = eigen_values_real
  []
  [bnorm]
    type = ElmIntegTotFissNtsPostprocessor
    block = 0
    execute_on = linear
  []
  [tot_fissions]
    type = ElmIntegTotFissPostprocessor
    execute_on = linear
  []
  [powernorm]
    type = ElmIntegTotFissHeatPostprocessor
    execute_on = linear
  []
  [group1norm]
    type = ElementIntegralVariablePostprocessor
    variable = group1
    execute_on = linear
  []
  [group1max]
    type = NodalExtremeValue
    value_type = max
    variable = group1
    execute_on = timestep_end
  []
  [group1diff]
    type = ElementL2Diff
    variable = group1
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
  [group2norm]
    type = ElementIntegralVariablePostprocessor
    variable = group2
    execute_on = linear
  []
  [group2max]
    type = NodalExtremeValue
    value_type = max
    variable = group2
    execute_on = timestep_end
  []
  [group2diff]
    type = ElementL2Diff
    variable = group2
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
[]

[VectorPostprocessors]
  [k_vpp]
    type = Eigenvalues
    inverse_eigenvalue = true
  []
  [centerline_flux]
    type = LineValueSampler
    variable = 'group1 group2'
    start_point = '0 0 0'
    end_point = '0 150 0'
    num_points = 151
    sort_by = y
    execute_on = FINAL
  []
  [midplane_flux]
    type = LineValueSampler
    variable = 'group1 group2'
    start_point = '0 75 0'
    end_point = '69.375 75 0'
    num_points = 100
    sort_by = x
    execute_on = FINAL
  []
[]

[Outputs]
  perf_graph = true
  print_linear_residuals = true
  [exodus]
    type = Exodus
  []
  [csv]
    type = CSV
  []
[]

(tests/materials/mjm_none.i)

[GlobalParams]
  num_groups = 2
  num_precursor_groups = 6
  use_exp_form = false
  group_fluxes = 'group1 group2'
  temperature = 900
  sss2_input = true
  account_delayed = false
[]

[Mesh]
  [mesh]
    type = GeneratedMeshGenerator
    dim = 2
  []
[]

[Nt]
  var_name_base = group
  create_temperature_var = false
  eigen = true
[]

[Materials]
  [fuel]
    type = MoltresJsonMaterial
    base_file = 'xsdata-900K.json'
    material_key = 'fuel'
    interp_type = 'none'
  []
[]

[Executioner]
  type = Eigenvalue
  initial_eigenvalue = 1
  nl_abs_tol = 1e-12
  solve_type = 'NEWTON'
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
[]

[Preconditioning]
  [SMP]
    type = SMP
    full = true
  []
[]

[Postprocessors]
  [k_eff]
    type = VectorPostprocessorComponent
    index = 0
    vectorpostprocessor = k_vpp
    vector_name = eigen_values_real
  []
  [fiss_neutrons]
    type = ElmIntegTotFissNtsPostprocessor
    execute_on = linear
  []
  [tot_fissions]
    type = ElmIntegTotFissPostprocessor
    execute_on = linear
  []
  [group1diff]
    type = ElementL2Diff
    variable = group1
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
[]

[VectorPostprocessors]
  [k_vpp]
    type = Eigenvalues
    inverse_eigenvalue = true
  []
[]

[Outputs]
  perf_graph = true
  print_linear_residuals = true
  [out]
    type = Exodus
  []
[]

[Debug]
  show_var_residual_norms = true
[]

(tests/materials/mjm_monotone_cubic.i)

[GlobalParams]
  num_groups = 2
  num_precursor_groups = 6
  use_exp_form = false
  group_fluxes = 'group1 group2'
  temperature = 922
  sss2_input = true
  account_delayed = false
[]

[Mesh]
  [mesh]
    type = GeneratedMeshGenerator
    dim = 2
  []
[]

[Nt]
  var_name_base = group
  create_temperature_var = false
  eigen = true
[]

[Materials]
  [fuel]
    type = MoltresJsonMaterial
    base_file = 'xsdata.json'
    material_key = 'fuel'
    interp_type = 'monotone_cubic'
  []
[]

[Executioner]
  type = Eigenvalue
  initial_eigenvalue = 1
  nl_abs_tol = 1e-12
  solve_type = 'NEWTON'
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
[]

[Preconditioning]
  [SMP]
    type = SMP
    full = true
  []
[]

[Postprocessors]
  [k_eff]
    type = VectorPostprocessorComponent
    index = 0
    vectorpostprocessor = k_vpp
    vector_name = eigen_values_real
  []
  [fiss_neutrons]
    type = ElmIntegTotFissNtsPostprocessor
    execute_on = linear
  []
  [tot_fissions]
    type = ElmIntegTotFissPostprocessor
    execute_on = linear
  []
  [group1diff]
    type = ElementL2Diff
    variable = group1
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
[]

[VectorPostprocessors]
  [k_vpp]
    type = Eigenvalues
    inverse_eigenvalue = true
  []
[]

[Outputs]
  perf_graph = true
  print_linear_residuals = true
  [out]
    type = Exodus
  []
[]

[Debug]
  show_var_residual_norms = true
[]

(tests/postprocessors/neutron_leakage.i)

[GlobalParams]
  group_fluxes = 'group1 group2'
  num_groups = 2
  num_precursor_groups = 0
  use_exp_form = false
  temperature = 900
  sss2_input = true
[]

[Mesh]
  [gmg]
    type = GeneratedMeshGenerator
    dim = 2
    nx = 2
    ny = 2
    xmax = 1
    ymax = 1
  []
[]

[Variables]
  [group1]
  []
  [group2]
  []
[]

[Kernels]
  [group1_diffusion]
    type = GroupDiffusion
    variable = group1
    group_number = 1
  []
  [group2_diffusion]
    type = GroupDiffusion
    variable = group2
    group_number = 2
  []
[]

[BCs]
  [group1_left]
    type = DirichletBC
    variable = group1
    boundary = left
    value = 3
  []
  [group1_right]
    type = DirichletBC
    variable = group1
    boundary = right
    value = 2
  []
  [group2_left]
    type = DirichletBC
    variable = group2
    boundary = left
    value = 30
  []
  [group2_right]
    type = DirichletBC
    variable = group2
    boundary = right
    value = 20
  []
[]

[Materials]
  [mat]
    type = MoltresJsonMaterial
    base_file = mat.json
    material_key = 'mat1'
    interp_type = 'none'
    group_constants = 'DIFFCOEF'
  []
[]

[Executioner]
  type = Steady
[]

[Postprocessors]
  [group1_leakage]
    type = NeutronLeakage
    variable = group1
    boundary = 'right'
    group_number = 1
  []
  [group2_leakage]
    type = NeutronLeakage
    variable = group2
    boundary = 'right'
    group_number = 2
  []
  [total_leakage]
    type = TotalNeutronLeakage
    boundary = 'right'
  []
[]

[Outputs]
  csv = true
[]

(tests/materials/mjm_spline.i)

[GlobalParams]
  num_groups = 2
  num_precursor_groups = 6
  use_exp_form = false
  group_fluxes = 'group1 group2'
  temperature = 922
  sss2_input = true
  account_delayed = false
[]

[Mesh]
  [mesh]
    type = GeneratedMeshGenerator
    dim = 2
  []
[]

[Nt]
  var_name_base = group
  create_temperature_var = false
  eigen = true
[]

[Materials]
  [fuel]
    type = MoltresJsonMaterial
    base_file = 'xsdata.json'
    material_key = 'fuel'
    interp_type = 'spline'
  []
[]

[Executioner]
  type = Eigenvalue
  initial_eigenvalue = 1
  nl_abs_tol = 1e-12
  solve_type = 'NEWTON'
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
[]

[Preconditioning]
  [SMP]
    type = SMP
    full = true
  []
[]

[Postprocessors]
  [k_eff]
    type = VectorPostprocessorComponent
    index = 0
    vectorpostprocessor = k_vpp
    vector_name = eigen_values_real
  []
  [fiss_neutrons]
    type = ElmIntegTotFissNtsPostprocessor
    execute_on = linear
  []
  [tot_fissions]
    type = ElmIntegTotFissPostprocessor
    execute_on = linear
  []
  [group1diff]
    type = ElementL2Diff
    variable = group1
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
[]

[VectorPostprocessors]
  [k_vpp]
    type = Eigenvalues
    inverse_eigenvalue = true
  []
[]

[Outputs]
  perf_graph = true
  print_linear_residuals = true
  [out]
    type = Exodus
  []
[]

[Debug]
  show_var_residual_norms = true
[]

(tutorial/transient/transient.i)

[GlobalParams]
  num_groups = 2
  num_precursor_groups = 6
  use_exp_form = false
  group_fluxes = 'group1 group2'
  pre_concs = 'pre1 pre2 pre3 pre4 pre5 pre6'
  temperature = temp
  sss2_input = true
  account_delayed = true
[]

[Mesh]
  coord_type = RZ
  [mesh]
    type = FileMeshGenerator
    file = '../eigenvalue/mesh.e'
  []
[]

[Variables]
  [group1]
    order = FIRST
    family = LAGRANGE
  []
  [group2]
    order = FIRST
    family = LAGRANGE
  []
  [temp]
    order = FIRST
    family = LAGRANGE
    initial_condition = 1000
  []
[]

[Precursors]
  [pres]
    var_name_base = pre
    family = MONOMIAL
    order = CONSTANT
    block = 0
    outlet_boundaries = 'fuel_top'
    constant_velocity_values = true
    u_def = 0
    v_def = 18.085
    w_def = 0
    nt_exp_form = false
    loop_precursors = false
    transient = true
  []
[]

[Kernels]
  #---------------------------------------------------------------------
  # Group 1 Neutronics
  #---------------------------------------------------------------------
  [time_group1]
    type = NtTimeDerivative
    variable = group1
    group_number = 1
  []
  [sigma_r_group1]
    type = SigmaR
    variable = group1
    group_number = 1
  []
  [diff_group1]
    type = GroupDiffusion
    variable = group1
    group_number = 1
  []
  [inscatter_group1]
    type = InScatter
    variable = group1
    group_number = 1
  []
  [fission_source_group1]
    type = CoupledFissionKernel
    variable = group1
    group_number = 1
    block = '0'
  []
  [delayed_group1]
    type = DelayedNeutronSource
    variable = group1
    block = '0'
    group_number = 1
  []

  #---------------------------------------------------------------------
  # Group 2 Neutronics
  #---------------------------------------------------------------------
  [time_group2]
    type = NtTimeDerivative
    variable = group2
    group_number = 2
  []
  [sigma_r_group2]
    type = SigmaR
    variable = group2
    group_number = 2
  []
  [diff_group2]
    type = GroupDiffusion
    variable = group2
    group_number = 2
  []
  [fission_source_group2]
    type = CoupledFissionKernel
    variable = group2
    group_number = 2
    block = '0'
  []
  [inscatter_group2]
    type = InScatter
    variable = group2
    group_number = 2
  []

  #---------------------------------------------------------------------
  # Temperature
  #---------------------------------------------------------------------
  [temp_time_derivative]
    type = INSTemperatureTimeDerivative
    variable = temp
  []
  [temp_advection_fuel]
    type = ConservativeTemperatureAdvection
    variable = temp
    velocity = '0 18.085 0'
    block = '0'
  []
  [temp_diffusion]
    type = MatDiffusion
    variable = temp
    diffusivity = 'k'
  []
  [temp_source_fuel]
    type = TransientFissionHeatSource
    variable = temp
    block = '0'
  []
[]

[BCs]
  [vacuum_group1]
    type = VacuumConcBC
    boundary = 'fuel_bottom fuel_top mod_bottom mod_top right'
    variable = group1
  []
  [vacuum_group2]
    type = VacuumConcBC
    boundary = 'fuel_bottom fuel_top mod_bottom mod_top right'
    variable = group2
  []
  [temp_inlet_bc]
    type = FunctionDirichletBC
    variable = temp
    boundary = 'fuel_bottom mod_bottom right'
    function = 'temp_bc_func'
  []
  [temp_outlet_bc]
    type = TemperatureOutflowBC
    variable = temp
    boundary = 'fuel_top'
    velocity = '0 18.085 0'
  []
[]

[ICs]
  [group1_ic]
    type = FunctionIC
    variable = group1
    function = ic_func
  []
  [group2_ic]
    type = FunctionIC
    variable = group2
    function = ic_func
  []
[]

[Functions]
  [temp_bc_func]
    type = ParsedFunction
    expression = '1000 - (1000-965) * tanh(t/1)'
  []
  [dt_func]
    type = ParsedFunction
    expression = 'if(t<50, if(t<30, .4, 5), 10)'
  []
  [ic_func]
    type = ParsedFunction
    expression = '1e5 * (-x^2+70^2) * (-y * (y-150))'
  []
[]

[Materials]
  [fuel]
    type = MoltresJsonMaterial
    block = '0'
    base_file = '../eigenvalue/xsdata.json'
    material_key = 'fuel'
    interp_type = LINEAR
    prop_names = 'rho k cp'
    prop_values = '2.146e-3 .0553 1967'
  []
  [graphite]
    type = MoltresJsonMaterial
    block = '1'
    base_file = '../eigenvalue/xsdata.json'
    material_key = 'graphite'
    interp_type = LINEAR
    prop_names = 'rho k cp'
    prop_values = '1.86e-3 .312 1760'
  []
[]

[Executioner]
  type = Transient
  end_time = 200

  nl_rel_tol = 1e-6
  nl_abs_tol = 1e-1

  automatic_scaling = true
  compute_scaling_once = false
  resid_vs_jac_scaling_param = 0.1
  scaling_group_variables = 'group1 group2; pre1 pre2 pre3 pre4 pre5 pre6; temp'

  solve_type = 'NEWTON'
  petsc_options = '-snes_converged_reason -ksp_converged_reason -snes_linesearch_monitor'
  petsc_options_iname = '-pc_type -pc_factor_shift_type -pc_factor_mat_solver_package'
  petsc_options_value = 'lu       NONZERO               superlu_dist'

  line_search = none

  dtmin = 1e-3
  dtmax = 10
  [TimeStepper]
    type = FunctionDT
    function = dt_func
  []
  #  [TimeStepper]
  #    type = IterationAdaptiveDT
  #    dt = .2
  #    cutback_factor = 0.4
  #    growth_factor = 1.2
  #    optimal_iterations = 20
  #  []
[]

[Preconditioning]
  [SMP]
    type = SMP
    full = true
  []
[]

[Postprocessors]
  [tot_fissions]
    type = ElmIntegTotFissPostprocessor
    execute_on = linear
  []
  [powernorm]
    type = ElmIntegTotFissHeatPostprocessor
    execute_on = linear
  []
  [average_temp]
    type = ElementAverageValue
    variable = temp
    execute_on = linear
  []
  [inlet_temp]
    type = SideAverageValue
    variable = temp
    boundary = fuel_bottom
  []
  [outlet_temp]
    type = SideAverageValue
    variable = temp
    boundary = fuel_top
  []
[]

[VectorPostprocessors]
  [centerline_flux]
    type = LineValueSampler
    variable = 'group1 group2'
    start_point = '0 0 0'
    end_point = '0 150 0'
    num_points = 151
    sort_by = y
    execute_on = FINAL
  []
  [midplane_flux]
    type = LineValueSampler
    variable = 'group1 group2'
    start_point = '0 75 0'
    end_point = '69.375 75 0'
    num_points = 100
    sort_by = x
    execute_on = FINAL
  []
[]

[Outputs]
  perf_graph = true
  #  print_linear_residuals = true
  [exodus]
    type = Exodus
  []
  [csv]
    type = CSV
    execute_on = FINAL
  []
[]

[Debug]
  #  show_var_residual_norms = true
[]

(tutorial/eigenvalue/nts.i)

[GlobalParams]
  num_groups = 2
  num_precursor_groups = 6
  use_exp_form = false
  group_fluxes = 'group1 group2'
  pre_concs = 'pre1 pre2 pre3 pre4 pre5 pre6'
  temperature = 900
  sss2_input = true
  account_delayed = true
[]

[Mesh]
  coord_type = RZ
  [mesh]
    type = FileMeshGenerator
    file = 'mesh.e'
  []
[]

[Problem]
  type = EigenProblem
  bx_norm = bnorm
[]

[Variables]
  [group1]
    order = FIRST
    family = LAGRANGE
  []
  [group2]
    order = FIRST
    family = LAGRANGE
  []
[]

[Precursors]
  [pres]
    var_name_base = pre
    family = MONOMIAL
    order = CONSTANT
    block = 0
    outlet_boundaries = 'fuel_top'
    constant_velocity_values = true
    u_def = 0
    v_def = 18.085
    w_def = 0
    nt_exp_form = false
    loop_precursors = false
    transient = false
    eigen = true
  []
[]

[Kernels]
  #---------------------------------------------------------------------
  # Group 1 Neutronics
  #---------------------------------------------------------------------
  [sigma_r_group1]
    type = SigmaR
    variable = group1
    group_number = 1
  []
  [diff_group1]
    type = GroupDiffusion
    variable = group1
    group_number = 1
  []
  [inscatter_group1]
    type = InScatter
    variable = group1
    group_number = 1
  []
  [fission_source_group1]
    type = CoupledFissionKernel
    variable = group1
    group_number = 1
    block = '0'
    extra_vector_tags = 'eigen'
  []
  [delayed_group1]
    type = DelayedNeutronSource
    variable = group1
    block = '0'
    group_number = 1
  []

  #---------------------------------------------------------------------
  # Group 2 Neutronics
  #---------------------------------------------------------------------
  [sigma_r_group2]
    type = SigmaR
    variable = group2
    group_number = 2
  []
  [diff_group2]
    type = GroupDiffusion
    variable = group2
    group_number = 2
  []
  [fission_source_group2]
    type = CoupledFissionKernel
    variable = group2
    group_number = 2
    block = '0'
    extra_vector_tags = 'eigen'
  []
  [inscatter_group2]
    type = InScatter
    variable = group2
    group_number = 2
  []
[]

[BCs]
  [vacuum_group1]
    type = VacuumConcBC
    boundary = 'fuel_bottom fuel_top mod_bottom mod_top right'
    variable = group1
  []
  [vacuum_group2]
    type = VacuumConcBC
    boundary = 'fuel_bottom fuel_top mod_bottom mod_top right'
    variable = group2
  []
[]

[Materials]
  [fuel]
    type = MoltresJsonMaterial
    block = '0'
    base_file = 'xsdata.json'
    material_key = 'fuel'
    interp_type = LINEAR
    prop_names = ''
    prop_values = ''
  []
  [graphite]
    type = MoltresJsonMaterial
    block = '1'
    base_file = 'xsdata.json'
    material_key = 'graphite'
    interp_type = LINEAR
    prop_names = ''
    prop_values = ''
  []
[]

[Executioner]
  type = Eigenvalue
  initial_eigenvalue = 1
  solve_type = 'PJFNK'
  petsc_options = '-snes_converged_reason -ksp_converged_reason -snes_linesearch_monitor'
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'

  automatic_scaling = true
  compute_scaling_once = false
  resid_vs_jac_scaling_param = 0.1

  line_search = none
[]

[Postprocessors]
  [k_eff]
    type = VectorPostprocessorComponent
    index = 0
    vectorpostprocessor = k_vpp
    vector_name = eigen_values_real
  []
  [bnorm]
    type = ElmIntegTotFissNtsPostprocessor
    block = 0
    execute_on = linear
  []
  [tot_fissions]
    type = ElmIntegTotFissPostprocessor
    execute_on = linear
  []
  [powernorm]
    type = ElmIntegTotFissHeatPostprocessor
    execute_on = linear
  []
  [group1norm]
    type = ElementIntegralVariablePostprocessor
    variable = group1
    execute_on = linear
  []
  [group1max]
    type = NodalExtremeValue
    value_type = max
    variable = group1
    execute_on = timestep_end
  []
  [group1diff]
    type = ElementL2Diff
    variable = group1
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
  [group2norm]
    type = ElementIntegralVariablePostprocessor
    variable = group2
    execute_on = linear
  []
  [group2max]
    type = NodalExtremeValue
    value_type = max
    variable = group2
    execute_on = timestep_end
  []
  [group2diff]
    type = ElementL2Diff
    variable = group2
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
[]

[VectorPostprocessors]
  [k_vpp]
    type = Eigenvalues
    inverse_eigenvalue = true
  []
  [centerline_flux]
    type = LineValueSampler
    variable = 'group1 group2'
    start_point = '0 0 0'
    end_point = '0 150 0'
    num_points = 151
    sort_by = y
    execute_on = FINAL
  []
  [midplane_flux]
    type = LineValueSampler
    variable = 'group1 group2'
    start_point = '0 75 0'
    end_point = '69.375 75 0'
    num_points = 100
    sort_by = x
    execute_on = FINAL
  []
[]

[Outputs]
  perf_graph = true
  print_linear_residuals = true
  [exodus]
    type = Exodus
  []
  [csv]
    type = CSV
  []
[]

(tutorial/PinCell/pin_cell.i)

global_temperature = 600

[GlobalParams]
  num_groups = 2
  base_file = 'PinXS.json'
  group_fluxes = ' group1  group2'
  num_precursor_groups = 6
  use_exp_form = false
  temperature = ${global_temperature}
[]

[Mesh]
  file = pin_cell_mesh.e
[]

[Problem]
  type = FEProblem
  coord_type = XYZ
[]

[Nt]
  var_name_base = group
  create_temperature_var = false
  eigen = true
  account_delayed = 0
  sss2_input = 1
[]

[Materials]
  [F]
    type = MoltresJsonMaterial
    block = '1 2'
    material_key = 'F'
    interp_type = 'NONE'
    temperature = 600
    prop_names = ''
    prop_values = ''
  []
  [C]
    type = MoltresJsonMaterial
    block = 3
    material_key = 'C'
    interp_type = 'NONE'
    temperature = 600
    prop_names = ''
    prop_values = ''
  []
  [W]
    type = MoltresJsonMaterial
    block = 4
    material_key = 'W'
    interp_type = 'NONE'
    temperature = 600
    prop_names = ''
    prop_values = ''
  []
[]

[Executioner]
  type = NonlinearEigen
  max_power_iterations = 50
  xdiff = 'group1diff'

  bx_norm = 'bnorm'
  k0 = 1.0
  pfactor = 1e-2
  l_max_its = 100

  solve_type = 'NEWTON'
  petsc_options = '-snes_converged_reason -ksp_converged_reason -snes_linesearch_monitor'
  petsc_options_iname = '-pc_type -sub_pc_type'
  petsc_options_value = 'asm lu'
[]

[Preconditioning]
  [SMP]
    type = SMP
    full = true
  []
[]

[Postprocessors]
  [bnorm]
    type = ElmIntegTotFissNtsPostprocessor
    execute_on = linear
  []
  [tot_fissions]
    type = ElmIntegTotFissPostprocessor
    execute_on = linear
  []
  [group1norm]
    type = ElementIntegralVariablePostprocessor
    variable = group1
    execute_on = linear
  []
  [group1max]
    type = NodalExtremeValue
    value_type = max
    variable = group1
    execute_on = timestep_end
  []
  [group1diff]
    type = ElementL2Diff
    variable = group1
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
  [group2norm]
    type = ElementIntegralVariablePostprocessor
    variable = group2
    execute_on = linear
  []
  [group2max]
    type = NodalExtremeValue
    value_type = max
    variable = group2
    execute_on = timestep_end
  []
  [group2diff]
    type = ElementL2Diff
    variable = group2
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
[]

[Outputs]
  [out]
    type = Exodus
    execute_on = 'timestep_end'
  []
[]

(tests/materials/mjm_linear.i)

[GlobalParams]
  num_groups = 2
  num_precursor_groups = 6
  use_exp_form = false
  group_fluxes = 'group1 group2'
  temperature = 922
  sss2_input = true
  account_delayed = false
[]

[Mesh]
  [mesh]
    type = GeneratedMeshGenerator
    dim = 2
  []
[]

[Nt]
  var_name_base = group
  create_temperature_var = false
  eigen = true
[]

[Materials]
  [fuel]
    type = MoltresJsonMaterial
    base_file = 'xsdata.json'
    material_key = 'fuel'
    interp_type = 'linear'
  []
[]

[Executioner]
  type = Eigenvalue
  initial_eigenvalue = 1
  nl_abs_tol = 1e-12
  solve_type = 'NEWTON'
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
[]

[Preconditioning]
  [SMP]
    type = SMP
    full = true
  []
[]

[Postprocessors]
  [k_eff]
    type = VectorPostprocessorComponent
    index = 0
    vectorpostprocessor = k_vpp
    vector_name = eigen_values_real
  []
  [fiss_neutrons]
    type = ElmIntegTotFissNtsPostprocessor
    execute_on = linear
  []
  [tot_fissions]
    type = ElmIntegTotFissPostprocessor
    execute_on = linear
  []
  [group1diff]
    type = ElementL2Diff
    variable = group1
    execute_on = 'linear timestep_end'
    use_displaced_mesh = false
  []
[]

[VectorPostprocessors]
  [k_vpp]
    type = Eigenvalues
    inverse_eigenvalue = true
  []
[]

[Outputs]
  perf_graph = true
  print_linear_residuals = true
  [out]
    type = Exodus
  []
[]

[Debug]
  show_var_residual_norms = true
[]

Overview
Example Input File Syntax
Input Parameters
Input Files