Polonium attachment

Predetonation would reduce the bomb s efficiency, Berber repeated so also might postdetonation. When the pieces reach their best position we want to be very sure that a neutron starts the reaction before the pieces have a chance to separate and break. So there might be a third basic component to their atomic bomb besides nuclear core and confining tamper an initiator— Ra -h Be source or, better, a Po -t- Be source, with the radium or polonium attached perhaps to one piece of the core and the beryllium to the other, to smash together and spray neutrons when the parts mated to start the chain reaction. 

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. 

It has been reported for many years that condensation nuclei can be produced by ionizing radiation. Recent studies have improved the measurement of the activity size distribution of these ultrafine particles produced by radon and its daughters (Reineking, et al., 1985 Knutson, et al., 1985). It seems that the Po-218 ion is formed by the radon decay, is neutralized within a few tens of milliseconds, and then attached to an ultrafine particle formed by the radiolysis generated by the polonium ion recoil. Although there will be radiolysis along the alpha track, those reactions will be very far away (several centimeters) from the polonium nucleus when it reaches thermal velocity. The recoil path radiolysis therefore seems to be the more likely source of the ultrafine particles near enough to the polonium atom to rapidly incorporate it. 

The Po-218 activity was also attached to particles in the accumulation mode peak in the 0.1 to 1.0 pm range. The Po-214 (RaC ) activity was only observed in the accumulation mode and not associated with the ultrafine particles. Thus, the initial motion and deposition of much of the polonium-218 may be related to the transport by these ultrafine clusters. 

Ion exchange and solvent extraction data indicate that the compound contains one diethyldithiocarbamate ion attached to each polonium atom. It sublimes at about 110°C (81). 

Bones are actually living protein networks to which minerals attach themselves. Not aU of the minerals deposited on bones are essential to bone building. There are at least two dozen elements in bones that have no known function in the human body, as well as a handful of nonessential elements, such as boron, strontium, silicon, barium, bismuth, and arsenic (yes, arsenic), that are believed to do some good. Five toxic elements—lead, cadmium, mercury, polonium, and radium—are often found in human bones. As long as they are stabilized in the bones, they do no apparent harm. 

This polonium isotope is radioactive and is a nonvolatile heavy metal that can attach itself to bronchial or lung tissue, emitting hazardous radiation and producing other isotopes that are also radioactive. 

As usual, Fermi hewed the neutron experiments by hand. In February and early March he personally assembled crude Geiger counters from aluminum cylinders acquired by cutting the bottoms off tubes of medicinal tablets. Wired, filled with gas, their ends sealed and leads attached, the counters were slightly smaller than rolls of breath mints and a hundred times less efficient than modern commercial units, but with Fermi to operate them they served. While he built Geiger counters he asked Rasetti to prepare a neutron source in the form of polonium evaporated onto beryllium. Since polonium emits relatively low-energy alpha particles, the resulting source emitted relatively few neutrons per second, and Fermi and Rasetti irradiated several samples without success. 

In some instances, the source of radon is in wastes from uranium mining or phosphate production. In most cases, it is emitted by the radioactive decay of present in small amounts in rocks and soils. Because radon is a gas, it readily passes through air passages in the body and is breathed in and out. The product formed when a Rn atom gives up an a particle is the isotope polonium-218, which also emits a particles. Unlike radon, polonium is a solid. Health hazards posed by radon seem to be from Po and other radioactive decay products becoming attached to dust particles in the air and then being breathed into the lungs. 

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