Subcascade formation in displacement cascade simulations: Implications for fusion reactor materials
- Oak Ridge National Lab., TN (United States)
- Pacific Northwest National Lab., Richland, WA (United States)
Primary radiation damage formation in iron has been investigated by the method of molecular dynamics (MD) for cascade energies up to 40 keV. The initial energy EMD given to the simulated PKA is approximately equivalent to the damage energy in the standard secondary displacement model by Norgett, Robinson, and Torrens (NRT); hence, EMD is less than the corresponding PKA energy. Using the values of EMD in Table 1, the corresponding EPKA and the NRT defects in iron have been calculated using the procedure described in Ref. 1 with the recommended 40 eV displacement threshold. These values are also listed in Table 1. Note that the difference between the EMD and the PKA energy increases as the PKA energy increases and that the highest simulated PKA energy of 61.3 keV is the average for a collision with a 1.77 MeV neutron. Thus, these simulations have reached well into the fast neutron energy regime. For purposes of comparison, the parameters for the maximum DT neutron energy of 14.1 MeV are also included in Table 1. Although the primary damage parameters derived from the MD cascades exhibited a strong dependence on cascade energy up to 10 keV, this dependence was diminished and slightly reversed between 20 and 40 keV, apparently due to the formation of well-defined subcascades in this energy region. Such an explanation is only qualitative at this time, and additional analysis of the high energy cascades is underway in an attempt to obtain a quantitative measure of the relationship between cascade morphology and defect survival.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- Nuclear Regulatory Commission, Washington, DC (United States); USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 335408
- Report Number(s):
- DOE/ER-0313/23; ON: DE98004697; TRN: 99:005198
- Resource Relation:
- Other Information: PBD: Mar 1998; Related Information: Is Part Of Fusion materials semiannual progress report for the period ending December 31, 1997; Burn, G. [ed.] [comp.]; PB: 390 p.
- Country of Publication:
- United States
- Language:
- English
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