Stardust machine

The Stardust machine
The Stardust machine

The Stardust machine has been designed and assembled at the Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC). The elapsed time has been from October 2014 to the end of 2015. In 2016, we have entered into the commissioning phase with several ongoing verification experiments and processes. It is expected that first astrophysical experiments (the exploitation phase) will begin in the last term of 2016.

The Stardust machine is basically a forefront facility to produce and analyze in-situ highly-controlled analogs of the dust grains in a versatile ultra-high-vacuum experiment (up to pressures of 10-11 mbar) to reproduce the physical conditions that prevail in the photospheres of AGB stars. In this environment, the nucleation of the aggregates and their possible interaction with the circumstellar gases will be mimicked. The Stardust machine will characterize microscopic processes (interaction with photons and gas) through surface science techniques. It encompasses 5 independent vacuum chambers, with their own instrumentation, pumping systems, gas-dosed systems in a highly-controlled ultra-high vacuum (UHV) environment:

  • MICS (Multiple Ion Cluster Source) chamber. The MICS is a new optimized route for cluster growth of a standard technique based on a sputtering gas. It will allow the formation of nanoparticles of controlled elemental composition by atomic aggregation.
  • NEON (NEutral to iON) chamber that will separate neutral from ionized nanoparticles as well as a mass selection. It also accelerates, simulating the radiation pressure, and anneals the formed clusters.
  • INTERACTION chamber. Interaction and chemical reactions will be induced between the generated nanoparticles and molecules in the gas phase (H2, CH4, C2H2, etc).
  • INFRA chamber. In-flight analysis will be performed through UV, visible, near-mid and far-infrared spectroscopy as well as microwave spectroscopy with the new HEMT receivers (developed in CNIG/IGN) that will provide the opportunity to study second/minute time-dependent changes in the gas composition using these extremely sensitive radio astronomical receivers.
  • ANA chamber, the analysis chamber. This will allow us to collect the nanoparticles to perform X-ray photoelectron spectroscopy (XPS), thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES) and Ultraviolet photoelectron spectroscopy (UPS) in-situ. Also some in-situ processing can be performed here.

In summary, the Stardust machine will combine different techniques to achieve original studies on individual nanoparticles, their processing to produce complex molecules, the chemical evolution of their precursors and their reactivity with abundant astronomical molecules. The simulation chambers are equipped with state-of-the-art in situ and ex situ diagnostics.

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