Estimates of cluster-impact fusion yields

We present several theoretical estimates of D+D fusion rates for heavy-water molecular clusters impacting on TiD targets. Our considerations range from the simple thick-target yield to single- and multiple-deuteron knock-on to thermonuclear and thermal-spike models; detailed molecular-dynamics simulations are also presented. Each of our models fails, by many orders of magnitude, to reproduce the yields observed in recent experiments. We consider the extent to which experimental artifacts might contribute to the results claimed.