Alpha emitter

Polonium-210 is a low-melting, fairly volatile metal, 50% of which is vaporized in air in 45 hours at 55C. It is an alpha emitter with a half-life of 138.39 days. A milligram emits as many alpha particles as 5 g of radium. 

Twenty isotopes are known. Radon-22, from radium, has a half-life of 3.823 days and is an alpha emitter Radon-220, emanating naturally from thorium and called thoron, has a half-life of 55.6 s and is also an alpha emitter. Radon-219 emanates from actinium and is called actinon. It has a half-life of 3.96 s and is also an alpha emitter. It is estimated that every square mile of soil to a depth of 6 inches contains about 1 g of radium, which releases radon in tiny amounts into the atmosphere. Radon is present in some spring waters, such as those at Hot Springs, Arkansas. 

The isotope produced was the 20-hour 255Fm. During 1953 and early 1954, while discovery of elements 99 and 100 was withheld from publication for security reasons, a group from the Nobel Institute of Physics in Stockholm bombarded 238U with 160 ions, and isolated a 30-min alpha-emitter, which they ascribed to 250-100, without claiming discovery of the element. This isotope has since been identified positively, and the 30-min half-life confirmed. 

In 1967, Flerov and associates at the Dubna Laboratory reported their inability to detect an alpha emitter with a half-life of 8 s which was assigned by the Berkeley group to 257-103. This assignment has been changed to 258Lr or 259Lr. 

TRU are those containing isotopes, like 241Am and 243Am, that follow uranium in the periodic table and whose half-lives are >20 years. If their level of activity was more than 100 nanocuries of alpha-emitters per gram of waste material (up from 10 nanocuries/g in 1982), the waste could be disposed of by shallow burial. Otherwise, the waste had to be placed in retrievable storage for eventual transfer to a permanent repository. TRUs generally have low levels of radioactivity, generate very little heat, and can be handled by ordinary means without remote control (Eisenbud 1987 Murray 1994). 

Hegde AG, Bhat IS. 1983. Occupational exposure to airborne alpha emitters in a BWR atomic power station. Bull Radiat Prot 6(2) 25-28. 

Lefuma J, Chameaud J, Perraud R, et al. 1976. [An experimental study on a comparison between the toxic effects of radon-222 and its daughters on the lungs, and those exerted by alpha-emitters of the actinium series.] Occup Saf Health Ser 32 43-53. (French). 

BEIRIV. 1988. Health risks of radon and other internally deposited alpha emitters. Committee on the Biological Effects of Ionizing Radiations, National Research Council. Washington, DC National Academy Press. 

The brittle, silvery, shiny metal was long considered the last stable element of the Periodic Table. In 2003 it was unmasked as an extremely weak alpha emitter (half-life 20 billion years). Like thulium, there is only one isotope. Bismuth alloys have low melting points (fuses, fire sprinklers). As an additive in tiny amounts, it imparts special properties on a range of metals. Applied in electronics and optoelectronics. The oxichloride (BiOCl) gives rise to pearlescent pigments (cosmetics). As bismuth is practically nontoxic, its compounds have medical applications. The basic oxide neutralizes stomach acids. A multitalented element. Crystallizes with an impressive layering effect (see right). 

Polonium was considered a rarity. With beryllium, the alpha emitter generates a strong neutron flux. Used as the detonator in the first atomic bombs. 

Soft, silver white metal that is isolated in the tiniest of amounts. All isotopes are radioactive, the longest-lived has a half-life of 22 years. The element is an intermediate in the decay series of 235U. Strong alpha emitter that is used in radioactivation analysis and forms an effective neutron source with beryllium. 

Alpha Emitters. Proceedings, 8th Hot Laboratory and Equipment Conference, San Francisco, Calif., 13—15. Dez. i960. Report TID-7599, S. 21 Off. (1960). 

Both polonium nuclides are alpha emitters and therefore of particular concern. In health physics it is customary to differentiate between attached and unattached 218Po the former, usually the larger of the two consists of 218Po atoms attached to airborne particles which are copiously present in virtually every atmosphere the latter consists of a 218Po atom or ion, frequently surrounded by several dozen molecules of a condensible species present in the air. The purpose of this paper is to present a new method for measuring the size properties of these unattached 218Po clusters. 

Using the miner data for this purpose may be overestimating the risk due to indoor exposure, since it includes risks from simultaneous exposure to external gamma radiation, long lived alpha emitters. This effect, however, may be outweighed by the fact... 

Masse,R., Histiogenesis of Lung Tumors Induced in Rats by Inhalation of Alpha Emitters an Overview, in Pulmonary Toxicology of Respirable Particles (C.L. Sanders et al., eds) p. 498, C0NF - 791002, National Technical Information Service, Springfield, USA (1980). 

The main problems of the study of chromosome aberrations, caused by radon and daughters at their most frequently existing dose levels, i. e. boardering the natural burdens, ares (i) to get statistical significance at very low doses, and (ii) to study their induction by internal exposure to alpha emitters only. 

Any alpha emitter with physical half-life 3.7 TBq (100 TpCi) 3... 

Common radioactive material in use today includes the alpha emitters Americium-241 and Plutonim-238 the beta emitters Phosporus-32 and Strontium-90 and the gamma emitters Cesium-137, Cobalt-60, and Iridium-192 [44], These materials are commonly used in smoke detectors, oil exploration, industrial gauges, food and mail irradiation, cancer therapy, industrial radiography, and in research laboratories. 

Thorium is also an alpha emitter. Th-232 goes through six alpha and fonr beta decay steps before becoming the stable isotope Pb-208. Th-232 is sufficiently... 

During development of the Truex process, various monofunctional organophosphorus reagents [e.g., TBP DBBP (dibutylbutylphosphonate) HDEHP (di-(2-ethylhexyl)phosphoric acid)] were considered for removal of alpha-emitters from HNO3 waste solutions. Two typical flow sheets for the use of HDEHP and TBP are shown in Fig. 12.14. Because of the poor performance of these two extractants, the processes were complicated. Distribution ratios... 

Even though most isotopes of unnilseptium are alpha emitters, there is little radiation hazard because only a few atoms have been produced. 

The magnitude of AV is measured most conveniently by placing an air electrode (a radiation emitter Po210 [alpha-emitter]), near the surface (ca. millimeter in air), connected to an impedance electrometer. This is required since resistance in air is very high, but it is appreciably reduced by the radiation electrode. However, proper isolation is essential for the data to be reliable. 

Muller WA, Gdssner W, Hug 0, et al. 1978. Late effects after incorporation of the short-lived alpha-emitters radium-224 and thorium-227 in mice. Health Phys 35 33-55. 

---