# Arrhenius Mass Diffusion Coefficients

Computes a two-term Arrhenius diffusion coefficient

## Description

This material computes a two-term Arrhenius diffusion coefficient. Mass diffusion coefficients are defined using an equation with the Arrhenius form (Miller et al., 2009) (1)

where is a pre-exponential factor, is the activation energy, is the universal gas constant, and is temperature.

## Example Input Syntax


[./UO2_cesium_diffusion]
type = ArrheniusDiffusionCoef
d1 = 5.6e-8
q1 = 2.09e5
d2 = 5.2e-4
q2 = 3.62e5
block = 1
temp = temp
[../]
(test/tests/2d_arrhenius/2d_arrhenius_test.i)

## Input Parameters

• q1209000First activation energy (J/mol)

Default:209000

C++ Type:double

Description:First activation energy (J/mol)

• arrhenius_prpty_namearrhenius_diffusion_coefProperty name for the Arrhenius diffusion coefficient.

Default:arrhenius_diffusion_coef

C++ Type:std::string

Description:Property name for the Arrhenius diffusion coefficient.

• q2362000Second activation energy (J/mol)

Default:362000

C++ Type:double

Description:Second activation energy (J/mol)

• computeTrueWhen false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the Material via MaterialPropertyInterface::getMaterial(). Non-computed Materials are not sorted for dependencies.

Default:True

C++ Type:bool

Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the Material via MaterialPropertyInterface::getMaterial(). Non-computed Materials are not sorted for dependencies.

• tempCoupled Temp

C++ Type:std::vector

Description:Coupled Temp

• gas_constant8.3143Universal gas constant (J/mol-K)

Default:8.3143

C++ Type:double

Description:Universal gas constant (J/mol-K)

• d1_function_variableVariable to be used when evaluating d1_function. If not given, time will be used.

C++ Type:std::vector

Description:Variable to be used when evaluating d1_function. If not given, time will be used.

• boundaryThe list of boundary IDs from the mesh where this boundary condition applies

C++ Type:std::vector

Description:The list of boundary IDs from the mesh where this boundary condition applies

• d1_functionFunction to be multiplied by d1

C++ Type:FunctionName

Description:Function to be multiplied by d1

• d20.00052Second coefficient (m**2/s)

Default:0.00052

C++ Type:double

Description:Second coefficient (m**2/s)

• blockThe list of block ids (SubdomainID) that this object will be applied

C++ Type:std::vector

Description:The list of block ids (SubdomainID) that this object will be applied

• d15.6e-08First coefficient (m**2/s)

Default:5.6e-08

C++ Type:double

Description:First coefficient (m**2/s)

### Optional Parameters

• enableTrueSet the enabled status of the MooseObject.

Default:True

C++ Type:bool

Description:Set the enabled status of the MooseObject.

• 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

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.

• control_tagsAdds user-defined labels for accessing object parameters via control logic.

C++ Type:std::vector

Description:Adds user-defined labels for accessing object parameters via control logic.

• seed0The seed for the master random number generator

Default:0

C++ Type:unsigned int

Description:The seed for the master random number generator

• implicitTrueDetermines whether this object is calculated using an implicit or explicit form

Default:True

C++ Type:bool

Description:Determines whether this object is calculated using an implicit or explicit form

• 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 computeSubdomainProperties() 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

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 computeSubdomainProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

• output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)

C++ Type:std::vector

Description:List of material properties, from this material, to output (outputs must also be defined to an output type)

• outputsnone Vector of output names were you would like to restrict the output of variables(s) associated with this object

Default:none

C++ Type:std::vector

Description:Vector of output names were you would like to restrict the output of variables(s) associated with this object

## References

1. G. K. Miller, D. A. Petti, J. T. Maki, and D. L. Knudsen. PARFUME theory and model basis report. Technical Report INL/EXT-08-14497, Idaho National Laboratory, 2009.[BibTeX]