We have been working with our colleagues at the University of Heidelberg, Germany for the last two weeks, using their tandem van de graaf dust accelerator to fire submicron dust particles into aerogel tiles and aluminum foils. Zack Gainsforth from Berkeley is working with Frank Postberg, Ralf Srama and Eberhard Gruen on this important project.
We are shooting particles into flight spare aerogel tiles and aluminum foils at various velocities from 5 to 25 km/sec. The projectiles are submicron latex, aluminum, and iron spheres. Our goal is to determine the dependence of track and crater size (diameter and depth) on particle type and velocity. We are optimistic that this will lead to improved laboratory analogs for the interstellar dust impacts in the Stardust collectors. They still will not be perfect — an absolutely accurate laboratory simulation of interstellar dust impacts is probably impossible — so we still have to keep an open mind about the appearance of the tracks that we’re working so hard to find.
Also, over the last 10 days or so, our colleagues Frank Brenker, Bart Vekemans, Laszlo Vincze, Sylvia Schmitz and Manfred Burghammer have been looking at new picokeystones on the x-ray microprobe beamline ID21 at the European Synchrotron Radiation Facility This is a beautiful instrument, and the analyses have been going well.