Precisely controlled fabrication, manipulation and in-situ analysis of Cu based nanoparticles (L. Martínez, K. Lauwaet, G. Santoro, J. M. Sobrado, R. J. Peláez, V. J. Herrero, I. Tanarro, G. J. Ellis, J. Cernicharo, C. Joblin, Y. Huttel, and J. A. Martín-Gago). Scientific Reports 8, 7250 (13pp), 2018 May 8.
More information on the Stardust experimental set-up can be found here
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. Throughout 2016, we entered into the commissioning phase with several ongoing verification experiments and processes. The article shown above is the result of this commissioning phase. From mid-2017, we are dealing with the first astrophysical experiments, the so-called exploitation phase.
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 allows the formation of nanoparticles of controlled elemental composition by atomic aggregation. A special port has been adapted to perform optical spectroscopy.
- NEON (NEutral to iON) chamber that separates 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 are induced between the generated nanoparticles and molecules in the gas phase (H2, CH4, C2H2, etc).
- INFRA chamber. In-flight analysis is performed through UV, visible, near-mid and far-infrared spectroscopy. It is expected that microwave spectroscopy will be performed 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. A cryostat and a sample manipulator were acquired in order to study ice interstellar analogs.
- ANA chamber, the analysis chamber. This allows us to collect the nanoparticles and 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. The collected samples are duly transported and delivered to the AROMA setup for ulterior analysis.
In summary, the Stardust machine combines 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.