Nuclear stopping power and its impact on the determination of electronic stopping power

As already noted by Behar et al. in the nineties, the penetration depth of heavy ions into light targets is often much larger than predicted by Ziegler's SRIM (The Stopping and Range of Ions in Matter) program. Evidently, SRIM stopping power must be too high at low energy in these cases. This leads to the question: are there any stopping power measurements that show this directly? There are a few, indeed. We first discuss the description of nuclear stopping in SRIM, and then discuss these measurements. Naturally, the contribution of nuclear stopping is large in these cases. Assuming that SRIM nuclear stopping is correct, we find that indeed, SRIM electronic stopping is much too high at low energy.