polonium/staticmaster

[P3D Mark Josephson <icebox@xxxxxxx>]

There's been a lot of confusion about Polonium on the list.  
Here are some facts. This is taken from:
http://mwanal.lanl.gov/CST/imagemap/periodic/periodic.html
Oh, Polonium decays into lead once it loses the Alpha particle.

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History

(Poland, native country of Mme. Curie) Polonium, also called Radium F, 
was the first element discovered by Mme. Curie in 1898 while seeking the 
cause of radioactivity of pitchblend from Joachimsthal, Bohemia. The 
electroscope showed it separating with bismuth.

Sources

Polonium is a very rare natural element. Uranium ores contain only about 100
micrograms of the element per ton. Its abundance is only about 0.2% of 
that of radium. 

In 1934, scientists discovered that when they bombarded natural bismuth 
(209Bi) with neutrons, 210Bi, the parent of polonium, was obtained. 
Milligram amounts of polonium may now be prepared this way, by using the 
high neutron fluxes of nuclear reactors. 

Polonium is available commercially on special order from the Oak Ridge 
National Laboratory. 

Properties

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. 

The energy released by its decay is so large (140W/g) that a capsule 
containing about half a gram reaches a temperature above 500C. The 
capsule also presents a contact gamma-ray does rate of 0.012 Gy/h. A few 
curies (1 curie = 3.7 x 10^10Bq) of polonium exhibit a blue glow, caused 
by excitation of the surrounding gas. 

Uses

Because almost all alpha radiation is stopped within the solid source and 
its container, giving up its energy, polonium has attracted attention for 
uses as a lighweight heat source for thermoelectric power in space 
satellites. 

Polonium can be mixed or alloyed with beryllium to provide a source of 
neutrons. The element has been used in devices for eliminating static 
charges in textile mills, etc.; however, beta sources are both more 
commonly used and less dangerous. It is also used on brushes for removing 
dust from photographic films.

The plonium for these is carefully sealed and controlled, minimizing 
hazards to the user. 

Hazards

Polonium-210 is very dangerous to handle in even milligram or microgram
amounts, and special equipment and strict control is necessary. Damage arises
from the complete absorption of the energy of the alpha particle into 
tissue. 

The maximum permissible body burden for ingested polonium is only 0.03
microcuries, which represents a particle weighing only 6.8 x 10^-12 g. 
Weight for weight it is abot 2.5 x 10^11 times as toxic as hydrocyanic 
acid. The maximum allowable concentration for soluble polonium compounds 
in air is about 2 x 10^-11 microcuries/cm^3. 
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It seems safe enough, as long as you don't rip your static master apart 
and eat the polonium :)  I wonder what the beta-radiation 
anti-static devices they refer to would cost.  

---
Mark Josephson  |  UNLESS 
icebox@xxxxxxx  | 
-- 
Icebox in effect on WHPK 88.5 FM, Chicago, Wednesdays, 9PM-Midnite 


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