In-situ observation of cascade damage in gold under heavy ion irradiation at high temperature

Transmission Electron Microscopy Study of Cascade Collapse in Copper During in- Situ Ion- Irradiation at Elevated Temperatures

“…fully addressed. During ion-irradiation an increase in defect loss rate over those rates measured under similar conditions without ionirradiation has been observed [2,3]; this increase was reported to scale with influence. The immediate question arises as to whether a temperature dependence for the isothermal loss rate during ion-irradiation can account for the change in postirradiation yield.…”

Stability and Mobility of Interstitial-Type Defect Clusters Generated from Displacement Cascades in Copper and Gold by <I>In-Situ</I> Transmission Electron Microscopy

“…It is known that there are two and three lifetime components at 573 K and 673 K, respectively, indicating the varying nature of defect clusters. Ishino et al 10,27) claimed that vacancy-type loops and SFT could be observed by a combination of the bright-field and inside-outside techniques. We observed the same behavior in ion-irradiated gold.…”

“…A typical lifetime of SFT was several seconds or more, and that of the vacancy-type dislocation loops (V-clusters) was less than several seconds, as estimated in a previous work. 10) In addition to the above, we must note that tiny defects (a couple of nm) with much shorter lifetimes, lasting for several thirtieths of a second or less, were detected. These have not been previously reported, presumably because the WBDF technique enables higher spatial and time resolutions than those obtained by the bright-field technique.…”

“…To confirm the thermal stability of the defects and to clarify the nature-dependent lifetime in gold, we performed post-irradiation thermal annealing experiments under the beam-off condition. 8,10,11) This experiment considers in-situ observations as a function of time after ion irradiation has been terminated. At the moment of beam off, nonfatal mechanical vibrations were induced from an insert of a Faraday cup for several thirtieths of a second.…”

“…The simultaneous observations of the accumulation process and the instability of defect clusters under ion irradiations revealed that the fraction and size of surviving defects depend on irradiation conditions, such as incoming particles and temperature. [6][7][8][9][10][11][12][13] In-situ observations using high-voltage electron microscopes are also indispensable in detecting the motion of defect clusters in metals. 14,15) The motion suggests that dislocation loops transform into mobile defects enabling diffusion with relatively low activation energy; however, its mechanism has not yet been experimentally clarified.…”