Self-radiation

Weber, W. J., Wald, J. W. Matzke, Hi. 1986. Effects of self-radiation damage in Cm-doped Gd2Ti207 and CaZrTi2C>7. Journal of Nuclear Materials, 138, 196-209. 

Assumptions Base area is smooth and no direct self-radiation is intercepted by the base surface separating medium behveen surfaces is nonabsorbing emissivity is equal to absorptivity... 

Weber WJ (1990) Radiation-induced defeets and amorphization in zireon. J Mater Res 5 2687-2697 Weber WJ (1991) Self-radiation damage and reeoveiy in Pn-doped zircon. Radiation Effects Defects in Solids 115 341-349... 

The radiative exchange in a gas filled enclosure is more difficult to calculate than the exchange dealt with in 5.5.3, without an absorbing and therefore self radiating gas. In the following we will consider two simple cases, in which an isothermal gas is involved in radiative interchange with its boundary walls that are likewise at a uniform temperature. At the end of this section we will point to more complex methods with which more difficult radiative exchange problems may be solved. 

Fig. 8). As shown in Fig. 9, it is installed with self-radiation shielding, being under routine operation in the beam-current between 300 and 500 mA. 

Fig. 9 A photo of the commercially available ring AURORA-2S installed with self-radiation shielding...

Wald JW, Weber WJ (1984) Effects of self-radiation damage on the leachability of actinide-host phases. In Advances in Ceramics, Vol. 8. Wicks GG, Ross WA (eds) Am Ceram Soc, Columbus, Ohio, p 71-75 Wang LM (1998) Application of advanced transmission electron microscopy techniques in the study of radiation effects in insulators. Nucl Instr Meth Phys Res B 141 312-325 Wang LM and Ewing RC (1992) Ion beam induced amorphization of complex ceramic materials-minerals. Mater Res Soc Bull 17 38-44... 

Radiation doses of 10 Gy can induce decomposition effects of the order of 1 %. Samples whose specific activity exceed 40 GBq (1 Ci)/mol for or about 400 GBq (10 Ci) per mol for will receive a dose of this magnitude in a period of a year. Samples may be stored in benzene solution in vacuo or in deep freeze to minimize self-radiation effects and should be re-purified before use if the decomposition products are likely to affect the experiment. 

Here D = n qao and is the typical dipole mom t of a Rydberg atom. The collective field radiated is thus of order NE and for this to dominate the individual dipoles must be flipped by the self-radiated field in a time shorter than the spontaneous decay rate or other damping processes. The threshold condition is therefore. 

One of the inescapable problems associated with the storage of high specific activity hpids is self-radiation decomposition (Tolbert, 1963). Changes due to radiation decomposition can be minimized when solid supports and solvent molecules are added to help absorb a portion of the radiation energies and when recommended storage conditions are maintained for the satisfactory chemical preservation of polyunsaturated lipids (James, 1960). The term minimize should not be misconstrued to mean prevent regardless of the storage conditions, the purity of each lipid must be determined before each use. 

Certain types of equipment are specifically excluded from the scope of the directive. It is self-evident that equipment which is already regulated at Union level with respect to the pressure risk by other directives had to be excluded. That is the case with simple pressure vessels, transportable pressure equipment, aerosols and motor vehicles. Other equipment, such as carbonated drink containers or radiators and piping for hot water systems are excluded from the scope because of the limited risk involved. Also excluded are products which are subject to a minor pressure risk which are covered by the directives on machinery, lifts, low voltage, medical devices, gas appliances and on explosive atmospheres. A further and last group of exclusions refers to equipment which presents a significant pressure risk, but for which neither the free circulation aspect nor the safety aspect necessitated their inclusion. 

Cold-roUed alloys of lead with 0.06 wt % teUurium often attain ultimate tensile strengths of 25—30 MPa (3625—5350 psi). High mechanical strength, excellent creep resistance, and low levels of alloying elements have made lead—teUurium aUoys the primary material for nuclear shielding for smaU reactors such as those aboard submarines. The aUoy is self-supporting and does not generate secondary radiation. 

Phosphors usually contain activator ions in addition to the host material. These ions are dehberately added in the proper proportion during the synthesis. The activators and their surrounding ions form the active optical centers. Table 1 Hsts some commonly used activator ions. Some soflds, made up of complexes such as calcium tungstate [7790-75-2] CaWO, are self-activated. Also in many photolurninescence phosphors, the primary activator does not efficiently absorb the exciting radiation and a second impurity ion is introduced known as the sensitizer. The sensitizer, which is an activator ion itself, absorbs the exciting radiation and transfers this energy to the primary activator. 

The experimental and theoretical aspects of the radiation and self-induced conversion kinetics and equiUbria between the ortho and para forms of hydrogen, deuterium, and tritium have been correlated (17). In general, the radiation-induced transitions are faster than the self-induced transitions. 

J. W. Pyper and C. K. Briggs, The Ortho-Para Forms of Hydrogen, Deuterium and Tritium Radiation and Self-induced Conpersion Kinetics and Equilibrium, Eawrence Eipermore Eaboratoy Report UCRE-52278, 1977. 

Selbststrahltmg,/. self-emission (of rays), spontaneous radiation. 

Microporous insulation materials consist mainly of highly dispersed silica with a particle size of only 5-30 nm. The highly dispersed silica powder is pressed to plates, which receive heat treatment up to 800 °C, after which the plates are self-supporting and possess a micropore structure with pore diameter of 0.1pm. The addition of opacifiers to the highly dispersed silica starting material reduces the loss of heat by radiation. The dates for such insulation boards are shown in Table 18. 

Thus, the process of PAN transformation under the effect of IR radiation proceeds with considerable self-acceleration. The irradiation of uniaxially oriented PAN films gives a polymer with a distinct anisotropy of optical properties, dichroism in the visible spectral region in particular. Figure 8 presents dichroism curves [D =/(X)] at various angles (ip) between the polarization plane and the orientation axis. The same figure shows the dependence D =f(uniaxially oriented film. 

Mandelkow, E., Lange, G., Mandelkow, E.-M. Applications of Synchrotron Radiation to the Study of Biopolymers in Solution Time-Resolved X-Ray Scattering of Microtubule Self-Assembly and Oscillations. 151, 9-29 (1989). 

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