At-211 decays with 7.214(7) h half-life. It decays by 58.2% electron capture to short-lived Po-211 (T1/2 = 0.516(3) s) that decays in turn with 100% ɑ emission to stable Pb-207. Moreover, At-211 decays by 41.8% ɑ emission to quasi-stable Bi-207 (T1/2=31.6 years; only 26 Bq Bi-207 per 1 MBq of At-211 after decay of the latter) that decays in turn to stable Pb-207. Including its short-lived Po-211 daughter, the cumulative ɑ emission is 100% per At-211 decay with an average ɑ energy of 6.78 MeV.
Moreover, At-211 and its daughter Po-211 in equilibrium emit weak γ-rays at 567.7 keV (0.31%), 687.0 keV (0.26%) and 897.8 keV (0.32%).
The mean ɑ energy per decay is 6785 keV, the mean recoil energy (of Bi-207 or Pb-207 recoils respectively) is 131 keV, the mean electron energy per decay is 3 keV, and the mean photon energy per decay is 43 keV.
At-211 is produced by ɑ particle irradiation of metallic Bi-209 targets at the cyclotron ARRONAX.
The radiochemical separation is performed at ARRONAX (ARRONAX, Nantes, France) and activity will be shipped from there to the users.
Examples of use
|Production route||Bi-209(α,2n) At-211|
|Daughter||Decays to Po-211 which decays immediately (T1/2=0.5 s) to stable Pb-207 and Bi-207 that is quasi-stable (T1/2=31.6 y): cumulative 100% α, 100% EC|
|Primary Container||2.5 mL borosilicate glass V-vial with silicon rubber screw cap|
|Radioactive Concentration (gamma spectrometry)||n.a.|
|Appearance||Clear colourless solution|
|Radionuclide identification (gamma spectrometry)||570 keV, 687 keV and 898 keV gamma lines present|
|Radionuclidic Purity (gamma spectrometry)||At-210/At-211 < 0.5%|
|Chemical purity (ICP-OES)||n.a.|
|Molar activity (ICP-OES)||n.a.|
|Apparent Molar Activity||n.a.|
|pH (pH strips)||n.a.|
|Activity available||Tens of MBq on demand|
|Activity limit for UN2910 (excepted package) shipment||0.5 GBq in dry state or 50 MBq in liquid form|