Dear readers, First of all, a merry end-of-year thingie (insert name here) to all of you. Last week, I presented a short 15-minute talk at the MRS-J conference in Yokohama. While it was a nice opportunity to present and meet people, it is a relatively small conference. With that in mind, I decided to re-record the presentation and post in online so you can take what you want from it. I was slightly ill when re-recording so the edit is a bit choppy (after removing the sneezes). It is available on Youtube here (and embedded below). Please leave comments and/or thumbs up if you like, and follow me on twitter @drheaddamage if you want to hear more ramblings from this side. Lastly, the next video definitely should be a custom one explaining the monte-carlo method we’ve developed referred to in the video.
edited on 2011-07-20 14:51 to add equation defining observability Of course I could not leave you hanging after the last post with that question “does the observability still scale with the radius squared for samples with more than two particles?”. Short answer: yes. Long answer: mostly, with some interesting lessons w.r.t. q-angles and limitations. Click “more” to read on…
Abstract of this post: In this post, I will show that for a spherical two-particle system, the observability of the smaller particle scales with the inverse squared radius, quite different from the scattering power, which scales with the radius to the sixth power (volume squared). This means that scattering data with 1% error can be used to distinguish at most particles 1/20th the size of the largest particle present, and data with 0.1% error can be used to observe single particles at most 1/50th of the size of the largest particle. Beyond this, only proportional numbers of smaller particles can be observed. Additionally the point of maximum observability is determined to be at q*Rg~2.6 for numeric examples, and q*Rg~2.45 for an algebraic approximation.