Add Li2O properties

doc/content/bib/tmap8.bib

@@ -7,6 +7,75 @@ @book{Fogler1999
    year = {1999},
 }
 
+@article{Ohira1989Li2O,
+  author = {O'Hira, S. and Hayashi, T. and Okuno, K. and Kudo, H.},
+  title = {{Tritium dissolution in and release from Li$_2$O}},
+  journal = {Fusion Engineering and Design},
+  volume = {8},
+  pages = {335--338},
+  year = {1989},
+  doi = {10.1016/S0920-3796(89)80127-9},
+  url = {https://doi.org/10.1016/S0920-3796(89)80127-9},
+}
+
+@article{Tanifuji1987Li2O,
+  author = {Tanifuji, T. and Noda, K. and Takahashi, T. and Watanabe, H.},
+  title = {{Tritium release from neutron-irradiated Li$_2$O: Diffusion in single crystal}},
+  journal = {Journal of Nuclear Materials},
+  volume = {149},
+  number = {2},
+  pages = {227--232},
+  year = {1987},
+  doi = {10.1016/0022-3115(87)90481-8},
+  url = {https://doi.org/10.1016/0022-3115(87)90481-8},
+}
+
+@article{Kurasawa1991Li2O,
+  author = {Kurasawa, Toshimasa and Watanabe, Hitoshi},
+  title = {The influence of surface phenomena on in-situ tritium release from lithium oxide},
+  journal = {Journal of Nuclear Materials},
+  volume = {179--181},
+  pages = {851--854},
+  year = {1991},
+  doi = {10.1016/0022-3115(91)90222-S},
+  url = {https://doi.org/10.1016/0022-3115(91)90222-S},
+}
+
+@article{Terai1988TTTExLi2O,
+  author = {Terai, T. and Takahashi, Y. and Tanaka, S.},
+  title = {{In-situ tritium release experiments from solid breeding materials (TTTEx) - Released chemical form of tritium and its diffusivities in Li$_2$O}},
+  journal = {Fusion Engineering and Design},
+  volume = {7},
+  pages = {345--351},
+  year = {1988},
+  doi = {10.1016/S0920-3796(88)80023-1},
+  url = {https://doi.org/10.1016/S0920-3796(88)80023-1},
+}
+
+@article{Katsuta1983Li2O,
+  author = {Katsuta, H. and Konishi, S. and Yoshida, H.},
+  title = {{Solubility and diffusivity of hydrogen in Li$_2$O}},
+  journal = {Journal of Nuclear Materials},
+  volume = {116},
+  number = {2--3},
+  pages = {244--248},
+  year = {1983},
+  doi = {10.1016/0022-3115(83)90108-3},
+  url = {https://doi.org/10.1016/0022-3115(83)90108-3},
+}
+
+@article{Tetenbaum1985LiOHInLi2O,
+  author = {Tetenbaum, M. and Fischer, A. K. and Johnson, C. E.},
+  title = {{Investigation of the solubility of LiOH in solid Li$_2$O}},
+  journal = {Fusion Technology},
+  volume = {7},
+  number = {1},
+  pages = {53--56},
+  year = {1985},
+  url = {https://www.osti.gov/biblio/5969087},
+  note = {OSTI ID: 5969087},
+}
+
 @article{CODATA2021552941,
   author = {Eite Tiesinga and Peter Mohr and David Newell and Barry Taylor},
   title = {{CODATA} Recommended Values of the Fundamental Physical Constants: 2018},

doc/content/source/materials/Li2OTransportMaterials.md

@@ -0,0 +1,18 @@
+# Li2O Transport Materials
+
+This page groups the current Li2O transport-property material documentation.
+
+The current set includes:
+
+- [TritiumDiffusivityLi2O.md]
+- [TritiumSolubilityLi2O.md]
+
+## Current Scope
+
+- `TritiumDiffusivityLi2O` covers the shortlisted source-backed tritium diffusivity models for Li2O.
+- `TritiumSolubilityLi2O` currently targets reduced-species solubility only.
+
+## Still Deferred
+
+- Katsuta et al. (1983) Li2O solubility and H/D diffusivity models until the exact primary-source coefficients are verified.
+- Oxidized LiOH/LiOT solution chemistry as a direct scalar `solubility` law.

doc/content/source/materials/TritiumDiffusivityLi2O.md

@@ -0,0 +1,47 @@
+# TritiumDiffusivityLi2O
+
+!syntax description /Materials/TritiumDiffusivityLi2O
+
+## Overview
+
+`TritiumDiffusivityLi2O` provides literature-based tritium diffusivity correlations for Li2O and
+creates both a regular and an AD Real-value material property from the same object.
+
+The class computes the diffusivity $D$ of tritium in Li$_2$O in m$^2$/s.
+The literature fits are implemented as published and stored in the implementation directly in m$^2$/s.
+The [!param](/Materials/TritiumDiffusivityLi2O/model) parameter is required because the available
+Li$_2$O correlations correspond to different irradiation states and microstructures.
+
+## Implemented Models
+
+The implemented diffusivity models are summarized in [li2o_diffusivity_models_table] and
+plotted in [li2o_diffusivity_models_figure].
+
+!table id=li2o_diffusivity_models_table caption=Implemented Li$_2$O tritium diffusivity models. All Arrhenius expressions use the ideal gas constant value from [PhysicalConstants](source/utils/TMAP8PhysicalConstants.md).
+| Enum | Expression used in TMAP8 | Property units | Validity range (K) | Reference | Notes |
+| :- | :- | :- | :- | :- | :- |
+| `Ohira1989` | $D = 1.2 \times 10^{-11}\exp(-45.1\times10^3/RT)$ | m$^2$/s | 600-711 | [!cite](Ohira1989Li2O) | Tritium in unirradiated single-crystal Li$_2$O |
+| `Tanifuji1987` | $D = 1.16 \times 10^{-5}\exp(-101\times10^3/RT)$ | m$^2$/s | 573-950 | [!cite](Tanifuji1987Li2O) | Tritium release from neutron-irradiated Li$_2$O single-crystal particles |
+| `Kurasawa1991` | $D = 2.0 \times 10^{-7}\exp(-81.7\times10^3/RT)$ | m$^2$/s | 723.15-1093.15 | [!cite](Kurasawa1991Li2O) | In-situ tritium release interpretation for single-crystal Li$_2$O |
+| `Terai1988Grain` | $D_g = 1.27 \times 10^{-9}\exp(-54.9\times10^3/RT)$ | m$^2$/s | 633.15-873.15 | [!cite](Terai1988TTTExLi2O) | Grain diffusivity from TTTEx polycrystalline Li$_2$O analysis under $\Phi = 10^{8} n/cm$^2$/s irradiation |
+| `Terai1988GrainBoundary` | $D_{int} = 1.61 \times 10^{-2}\exp(-95.1\times10^3/RT)$ | m$^2$/s | 633.15-873.15 | [!cite](Terai1988TTTExLi2O) | Grain-boundary diffusivity from TTTEx polycrystalline Li$_2$O analysis under $\Phi = 10^{8} n/cm$^2$/s irradiation |
+
+Note that the models are not interchangeable descriptions of the same specimen.
+They reflect different combinations of material microstructures and irradiation damage.
+
+The [!param](/Materials/TritiumDiffusivityLi2O/validity_action) parameter controls how TMAP8
+responds when a model is evaluated outside its documented temperature range.
+
+!media plot_li2o_review_models.py
+       image_name=li2o_diffusivity_models.png
+       style=width:80%;margin-bottom:2%;margin-left:auto;margin-right:auto
+       id=li2o_diffusivity_models_figure
+       caption=Comparison of the implemented Li$_2$O tritium diffusivity correlations from [li2o_diffusivity_models_table].
+
+!syntax parameters /Materials/TritiumDiffusivityLi2O
+
+!syntax inputs /Materials/TritiumDiffusivityLi2O
+
+!syntax children /Materials/TritiumDiffusivityLi2O
+
+!bibtex bibliography

doc/content/source/materials/TritiumSolubilityLi2O.md

@@ -0,0 +1,61 @@
+# TritiumSolubilityLi2O
+
+!syntax description /Materials/TritiumSolubilityLi2O
+
+## Overview
+
+`TritiumSolubilityLi2O` provides reduced-species hydrogen isotope solubility models for Li2O and creates
+both a regular and an AD Real-valued material property from the same Material object.
+
+The current implementation targets reduced gas-species hydrogen isotope dissolution behavior represented
+with a Sieverts-law type coefficient,
+
+!equation
+C = K_s P^{1/2},
+
+where $K_s$ is provided by the selected literature model.
+
+## Modeling Scope
+
+The Li2O literature does not currently support treating all reported chemistry as one scalar solubility model.
+
+Two regimes need to stay distinct:
+
+1. Reduced-species hydrogen isotope dissolution and transport.
+   This is the regime targeted by this implementation of `TritiumSolubilityLi2O`.
+
+2. Oxidized LiOH/LiOT solution chemistry.
+   This regime matters for inventory and release at higher hydrogen isotope content, but it is not implemented here.
+
+## Implemented Models
+
+The implemented solubility model is summarized in [li2o_solubility_models_table] and plotted in
+[li2o_solubility_models_figure].
+
+!table id=li2o_solubility_models_table caption=Implemented Li$_2$O reduced-species hydrogen isotope solubility model. The implemented model uses the ideal gas constant provided by [PhysicalConstants](source/utils/TMAP8PhysicalConstants.md).
+| Enum | Expression used in TMAP8 | Property units | Validity range (K) | Reference | Notes |
+| :- | :- | :- | :- | :- | :- |
+| `Ohira1989Tritium` | $K_{s,T} = \exp(1290/T + 1.14)$ | atm$^{1/2}$ | 583-963 K | [!cite](Ohira1989Li2O) | Reduced-species tritium dissolution in single-crystal Li2O |
+| `Ohira1989Hydrogen` | $K_{s,T} = \exp(1271/T + 2.33)$ | atm$^{1/2}$ | 476-963 K | [!cite](Ohira1989Li2O) | Reduced-species hydrogen dissolution in single-crystal Li2O |
+!alert warning title=Inconsistency in temperature range for `Ohira1989Hydrogen` in [!cite](Ohira1989Li2O). 
+In [!cite](Ohira1989Li2O), the test above Eq. (3) states that the upper temperature of the range of validity of the hydrogen solubility is 596 K, but Fig. (3) of the same paper shows values up to around 963 K (as for tritium). In this implementation, we therefore use the value from the figure (i.e., 963 K) and assume that the upper limit in the text is a typo. 
+!media plot_li2o_review_models.py
+       image_name=li2o_solubility_models.png
+       style=width:80%;margin-bottom:2%;margin-left:auto;margin-right:auto
+       id=li2o_solubility_models_figure
+       caption=Comparison of the implemented Li$_2$O hydrogen isotope solubility correlations from [li2o_solubility_models_table].
+
+The broader Li$_2$O solubility literature also includes H/D reduced-species measurements
+from [!cite](Katsuta1983Li2O) and oxidized LiOH-in-Li$_2$O solution chemistry from
+[!cite](Tetenbaum1985LiOHInLi2O), but those models are not implemented here yet.
+
+The [!param](/Materials/TritiumSolubilityLi2O/validity_action) parameter controls how TMAP8
+responds when a model is evaluated outside its documented temperature range.
+
+!syntax parameters /Materials/TritiumSolubilityLi2O
+
+!syntax inputs /Materials/TritiumSolubilityLi2O
+
+!syntax children /Materials/TritiumSolubilityLi2O
+
+!bibtex bibliography