"The Alpha particle speed is ~20000 km/s and they interact with matter, causing much ionisation over a very short distance. They usually pass short distances (a 5 MeV alpha particle will travel about 20 micrometres in silicon) and can be stopped by a sheet of paper. Alpha particles do not produce Bremsstrahlung radiation when slowing down."
Expected headings
"Properties"
"Hazards"
"Applications"
"Alpha decay (a.k.a. α decay) is the radioactive process in which an alpha (α) particle (containing two neutrons and two protons) is ejected from the nucleus. An alpha particle is identical to the nucleus of a helium atom. All nuclei with an atomic number (Z) greater than 82, are considered unstable. These are considered “neutron-rich” and undergo alpha decay commonly."
"Alpha decay occurs in the nuclei of heavy elements, like radium, uranium, thorium, etc. When a nucleus of Ra (radium) decays, it emits an alpha particle and becomes an Rn (radon) nucleus. In general, during alpha decay, the atomic number (Z) is reduced by two, and the mass number (A), by four. For example, alpha decay generates Rn-222 with atomic number 86 and the mass number 222 from Ra-226 with the atomic number 88 and the mass number 226."
"Historically, radium and radon were the principal alpha emitters of medical interest. Radium-223 dichloride is still used today in treating osseous metastases. Other alpha emitters (e.g. actinium-225 (Ac-225), lead-212 and bismuth-213) are being researched for therapeutic approaches using radiopharmaceuticals that can target the delivery of short half-life alpha emitters into cancerous cells, with some (e.g. Ac-225-PSMA (Prostate-Specific Membrane Antigen)-617) in the clinical trials phase 6."