Radiation damage process

Slifkin, L.M. (1975) in Radiation Damage Processes in Materials, ed. Dupuy, C.H.S. (Noordhoff, Leiden). 

In the first part of this chapter, we provide an overview of the radiation damage processes that control the form of the irradiation-induced microstructure under the radiation conditions reactor pressure vessel (RPV) steels experience in service. We demonstrate that the irradiation damage in RPV steels can broadly be classified as matrix damage (for instance voids, interstitial clusters, dislocation loops, complexes trapped at sinks such as... 

Radiation Damage. It has been known for many years that bombardment of a crystal with energetic (keV to MeV) heavy ions produces regions of lattice disorder. An implanted ion entering a soHd with an initial kinetic energy of 100 keV comes to rest in the time scale of about 10 due to both electronic and nuclear coUisions. As an ion slows down and comes to rest in a crystal, it makes a number of coUisions with the lattice atoms. In these coUisions, sufficient energy may be transferred from the ion to displace an atom from its lattice site. Lattice atoms which are displaced by an incident ion are caUed primary knock-on atoms (PKA). A PKA can in turn displace other atoms, secondary knock-ons, etc. This process creates a cascade of atomic coUisions and is coUectively referred to as the coUision, or displacement, cascade. The disorder can be directiy observed by techniques sensitive to lattice stmcture, such as electron-transmission microscopy, MeV-particle channeling, and electron diffraction. 

Zirconium is used as a containment material for the uranium oxide fuel pellets in nuclear power reactors (see Nuclearreactors). Zirconium is particularly usehil for this appHcation because of its ready availabiUty, good ductiUty, resistance to radiation damage, low thermal-neutron absorption cross section 18 x 10 ° ra (0.18 bams), and excellent corrosion resistance in pressurized hot water up to 350°C. Zirconium is used as an alloy strengthening agent in aluminum and magnesium, and as the burning component in flash bulbs. It is employed as a corrosion-resistant metal in the chemical process industry, and as pressure-vessel material of constmction in the ASME Boiler and Pressure Vessel Codes. 

The process responsible for initiating RES follows from the earlier discussion of radiation damage in graphite. Specifically, in a displacement event a Frenkel pair... 

T.D. Burchell, Radiation Damage in Carbon Materials. In Physical Processes of the Interaction of Fusion Plasmas with Solids, W.O. Hofer and J. Roth, Eds., 1996, Academic Press, pp. 341-382. 

The radicals are produced by various processes, although little is known for certain. A major question exists as to whether the radicals are produced by the initial bond rupture - , by recoil impact , by Auger ionization , by gamma radiation damage or by normal exchange . ... 

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