Gamma ray heating

Specimens used in tests were sections of cables with PVC outer coating. PVC was plasticized with DOF softener. The materials considered were exposed to the radiation and thermal aging. The samples have been irradiated at room temperature by hard gamma rays with 10 rad/sec dose power. A number of samples had been heated for long different times at 90°C. Besides a special specimens were cut out from outer coating for test on tensile machine like "Instron". The total doses of irradiation, times of heating and elongations at break obtained with "Instron" are listed in Table 1. 

Natural titanium is reported to become very radioactive after bombardment with deuterons. The emitted radiations are mostly positrons and hard gamma rays. The metal is dimorphic. The hexagonal alpha form changes to the cubic beta form very slowly at about 88O0C. The metal combines with oxygen at red heat, and with chlorine at 550oC. 

In the spring of 1989, it was announced that electrochemists at the University of Utah had produced a sustained nuclear fusion reaction at room temperature, using simple equipment available in any high school laboratory. The process, referred to as cold fusion, consists of loading deuterium into pieces of palladium metal by electrolysis of heavy water, E)20, thereby developing a sufficiently large density of deuterium nuclei in the metal lattice to cause fusion between these nuclei to occur. These results have proven extremely difficult to confirm (20,21). Neutrons usually have not been detected in cold fusion experiments, so that the D-D fusion reaction familiar to nuclear physicists does not seem to be the explanation for the experimental results, which typically involve the release of heat and sometimes gamma rays. 

With the exception of diamond coloring and the turning of topa2 blue, the source of the irradiation is immaterial. Gamma rays are the preferred source because of uniformity of coloration and the absence of heating and induced radioactivity. The most commonly seen gemstones enhanced by irradiation are summari2ed in Table 4. 

An expanding development is the use of peroxodisulfates as oxidants in organic chemistry (80,81). These reactions are initiated by heat, light, gamma rays, or transition-metal ions. The primary oxidising species is usually the sulfate ion radical, P hskip -3pt peroxodisulfate anion... 

In the past, the extraction of Sr and Cs was investigated for some practical applications (heat and gamma ray sources) but the main interest today is for decreasing the thermal power and the potential hazard of nuclear waste in underground repositories. Results of extractions with some... 

We now have clear evidence of non-thermal processes in the sky. A whole panoply of violent activities is revealed to the watchful eye of our radio. X-ray and gamma-ray telescopes. Supernova remnants, pulsars, active galactic nuclei and gamma bursts emit radiation that has clearly nothing to do with thermal activity, for their spectra bear no resemblance to those of heated bodies. 

Conventional tin and glass containers can be satisfactorily treated by steam or hot air. Paper, cardboard, and heat-sensitive plastics require subtler techniques. Experiments with Co60 gamma rays indicate that 200,000 r. are sufficient to inactivate vegetative contaminants, while the customary 2 X 10 r. are required for spore formers. These doses are considerably below those that would be expected to have any effect on the physical properties of these materials (Sec. IIIC5). 

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