JC259 & JC259Z-4 are a field-castable dry mix that provides excellent neutron shielding characteristics.
It is typically cast into closed containers and retains its hydrogen content even at elevated temperatures. JC259 contains 0.9% boron. For better thermal neutron attenuation JC259Z-4 contains 4% boron.
JC259 is mixed on-site with water and provides a hydrogen atom density that is roughly 6% greater than that of pure water. While the recommended temperature limit for JC259 is 150 °F (66 °C), it will retain about 80% of its hydrogen content up to 300 °F (140 °C).
JC259 can be poured in layers and each layer forms a solid bond with the one underneath. It requires approximately 56lbs. of JC259 dry mix to produce 1 ft³ of cast material. The material is typically provided in fibre barrels weighing 165lbs (net).
Features at a glance
- Excellent neutron shielding with 0.9% to 4% boron additive
- Field-castable into closed containers
- Maintains 80% of its very high hydrogen content up to 300°F
- Uses include, walls, back filling and roof slabs for cyclotron facilities
- Sets up in about 30 minutes, requires only mixing with water
|Composition Data (as cast):||JC259||JC259Z-4|
|Hydrogen atom density / cm³:||7.15 x 10²²||6.98 x 10²²|
|Hydrogen weight percent:||10.40%||10.10%|
|Boron atom density / cm³:||5.82 x 10²⁰||2.57 x 10²¹|
|Boron natural isotope distribution:||19.6% ¹⁰B and 80.4% ¹¹B||19.6% ¹⁰B and 80.4% ¹¹B|
|Boron weight percent:||0.91%||4.00%|
|Total Density:||1.15g/cm³ (72 lbs/ft³)||1.15g/cm³ (72 lbs/ft³)|
|Macroscopic thermal neutron cross section:||0.46 (cm⁻¹)||1.96 (cm⁻¹)|
|Gamma resistance:||5x10⁸ rad||5x10⁸ rad|
|Neutron resistance:||2.5x10¹⁷ n/cm²||2.5x10¹⁷ n/cm²|
|State:||Solid composite with pellets||Solid composite with pellets|
|Odour:||No odour||No odour|
|Recommended Temperature Limit:||150°F (66°C)||150°F (66°C)|
|Chemical Name & Synonyms:||Borated hydrogenated mix||Borated hydrogenated mix|
|Trade Name & Synonyms:||JC259 Polykast||JC259Z-4 Polykast|
|Chemical Family:||Ca salt, B, polyolefins||Ca salt, B, polyolefins|
|Solubility in Water:||<1% (cast)||<1% (cast)|
|Reactive Metals and Metal Compounds:||Aluminium|
|Materials to Avoid:||Water, potassium and acetic anhydride.|
|Not compatible with aluminium housings|
|Gas:||C, CO, CO₂, H₂O, organic vapours|
|Hazardous Polymerisation:||Will Not Occur|