Interplanetary and Interstellar Dust

Refractory cosmic dust analogues, such as mineral, polymer or metal powders, are prepared and characterised using a range of techniques, including:

• Planetary Ball Milling

  Using a Retsch PM100 CM planetary ball mill, with zirconium or hardened steel milling chambers and balls, we can produce ultrafine sub-micron and micron-scale powders for subsequent metal coating and acceleration as cosmic dust analogues, or use in hydrothermal experiments which seek to simulate the subsurface environment of Enceladus.

• Pycnometry

  Our Micromeritics Accupyc II 1340, with 1 cc insert, can measure the bulk density of small solid or powder samples. Surface Area and Porosity Analysis - a Micromeritics Gemini VII 1390t enables the rapid determination of sample surface areas and pore distributions. A Micromeritics VacPrep 061, vacuum and flow sample preparation system allows volatile contaminants to be removed from samples prior to surface area or porosity analysis.

• Composition

  A Linseis PT 1000 thermogravimetric analyser, with optional vacuum system, enables the temperature-dependent masses of samples to be measured, providing information about sample composition - such as volatile and organic composition, mineral phases, and melting point, as samples are heated to up to 1100 °C under vacuum or inert gas flow.

Thus far, samples of a range of minerals, including antigorite, olivine (San Carlos, peridot), opal, muscovite, orthopyroxene, silica and diopside, as well as CV3 ( Allende) and CO3 ( NWA 13178) meteorites have been powdered and characterised to produce samples for use with impact ionisation mass spectrometers, impact and ablation experiments. After these dust analogue ensembles (powders) have been produced, they are then coated with a thin (<15 nm) layer of conductive material, typically a metal such as silver, palladium or platinum. This enables the grains to charge and accelerate at facilities such as U. Stuttgart's electrostatic accelerator.