Chemical properties
Cs-131 is usually in monovalent state.
Nuclear properties
Cs-131 decays by electron capture with a half-life of 9.69 days to stable Xe-131.
Cs-131 emits X rays, notably Kα at 29 keV (60.0(14)%) and Kβ at 34 keV (12.79(29) %). Cs-131 emits no γ rays REF.
The mean photon energy per Cs-131 decay is 22.4 keV and the mean electron energy emitted per decay is 5.0 keV REF. The electrons are short-range Auger electrons with <0.01 µm, <0.1 µm, <1 µm and >10 µm range, respectively REF.
Production
Cs-131 is produced indirectly by thermal neutron bombardment of enriched Ba-130 targets in RHF at ILL. Ba-131 is produced upon neutron capture on Ba-130, which decays (T1/2=11.52 days) to Cs-131 via electron capture. A radiochemical Cs/Ba separation via precipitation of Ba in the carbonate form leads to n.c.a. Cs-131.
Distribution
Radiochemical separations are performed at the Hevesy Laboratory (DTU). Activity will be shipped from there to the users or PRISMAP+ biomedical research facility as a chloride salt with NaCl carrier.
Examples of use
| Parameter | Specifications |
|---|---|
| Production route | Ba-130(n,γ)Ba-131(ε)Cs-131 |
| Daughter | Decays to stable Xe-131: 100% electron capture |
| Half-life | 9.69 d |
| Processing | Separation from Ba by precipitation |
| Primary Container | 2.5 mL borosilicate glass V-vial with silicone rubber screw cap |
| Product Grade | n.c.a. |
| Physical Form | Solid |
| Chemical Form | Cs-131 as the chloride salt with NaCl carrier |
| Radioactive Concentration (gamma spectrometry) | n.a. |
| Appearance | Salt |
| Radionuclide identification (gamma spectrometry) | No γ (29 keV and 34 keV X-rays present) |
| Radionuclidic Purity (gamma spectrometry) | 97% |
| Chemical purity (ICP-OES) | t.b.d. |
| Molar activity (ICP-OES) | t.b.d. |
| Apparent Molar Activity | t.b.d. |
| Microbiological quality | Bioburden and endotoxin burden can be analysed post release, upon request. |
| Bacterial endotoxin | Bioburden and endotoxin burden can be analysed post release, upon request. |
| pH (pH strips) | n.a. |
| Additional information | |
| Activity available | ~0.5 GBq |
| Activity limit for UN2910 (excepted package) shipment | 30 GBq in dry state or 3 GBq in liquid form |
| Other information |
