Development of Chemical Evolution Simular in Interstellar Space

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Primordial solid particles in the dark nebula consist of minuscule silicate minerals mantled by organic materials, and in turn by cosmochemical ice. When they are exposed to UV,cosmic rays, or some high energy sources such as collision and radiation, their physical and chemical properties are altered accordingly through thermal metamorphism, evaporation, and chemical and isotopic fractionations. The new molecules generated in those events become constituents of the next generation in interstellar space. In our own solar nebula, in ancient times, interstellar dust were altered and recycled in much the same way, collided each other, and coaggulated to primary bodies of miniature planets. Carbonaceous meteorites are debris of such celestial bodies.We have developed a new laboratory system that is capable of monitoring time-dependent evolution of molecules generated from primordial interstellar particles as they are exposed to controlled fluxes of various energy sources. With this new devi … More ce, we are able to investigate the physical environment of the primordial solar nebula, and hopefully decipher the origin of the solar system materials.The new device, "the cosmochemical evolution simulator" is equipped with three turbomolecular pumps, a main vacuum Chamber, and a diffentia11y-evacuated sub-chamber. The high vacuum system produces 10^<-10> Torr with no load, and better than 10^<-7> Torr during high-temperature heatings. The main vacuum chamber is equipped with a high-T tungsten heater, UV lamp, or IR lamp to provide high/low temperatures or high/low energies, with which primordial materials such as carbonaceous fine particles are heated, altered, and evaporated. The sub-chamber is used for mass spectrometric analyzes and photometry either with a quadrupole mass spectrometer or IR spectrophotometry attached to it. A criostat chamber in place of the sub-chamber attached to the main chamber provides a cold substrate for extreme low temperatures. Indigenous molecules generated from the primordial solid particles are condensed to reproduce interstellar ice and organic compounds.From these results, our primary goal, viz.development of chemical evolution simulator in interstellar space, is now complete. Less