### STP384: Remarks on Correlation Studies

Pages: 2 Published: Jan 1965

**Abstract**

There has been much discussion regarding the correlation of radiation effects; that is, trying to tie radiation effects together between different radiation environments. We originally devised theories for radiation effects dealing with both displacement effects(*permanent damage*) and ionization effects (transient effects). Since many of the simplest theories for predicting the magnitudes of these radiation effects did not seem to work, we were tempted to abandon them and approach the radiation damage problem from a more empirical standpoint. I would like to suggest that we return to some of the simple theories, examine how far we can apply them, and establish their region of validity, accuracy, and limitations. Consider first displacement effects. If we have a certain integrated flux φ(E) of particles of energy E, we calculate the total number of displaced atoms from the formula Nd=∫O∞∫EeEm(E)NOφ(E)σ(E,ER)N(ER)dERdE. N(ER=f(ER)ER∕2E¯t. where N^{o} is the density of atoms, σ(E, E^{R}) is the cross section with which an incident particle of energy E produces a recoil of energy E^{R}, N(E^{R}) is the number of displaced atoms resulting from a recoil of energy E^{R}, f(E^{R}) is the fraction of E^{R} going into displacement production, E^{t} is the displacement threshold, and Ē^{t} is the displacement threshold averaged over all collision directions.

**Paper ID:** STP44615S

**Committee/Subcommittee:** E10.93

**DOI:** 10.1520/STP44615S

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