Pulsed ion deflection to overcome detector saturation in cryogenic ice sampling

Area of Science:

• Astrochemistry
• Analytical Chemistry
• Spectroscopy

Background:

• UV photo-processing of cryogenic ices is crucial for understanding interstellar chemistry.
• Previous time-of-flight mass spectrometry (ToF-MS) methods faced limitations in detecting complex photoproducts due to detector dynamic range.
• The Mass Analytical Tool to Research Interstellar ICES (MATRICES) setup was previously developed for this purpose.

Purpose of the Study:

• To introduce a novel method for overcoming detector dynamic range limitations in ToF-MS for studying UV-processed ices.
• To enhance the sensitivity for detecting low-abundance, complex photoproducts in astrophysical ice analogs.
• To demonstrate the applicability of this technique for analyzing UV-irradiated methanol ice and other complex organic molecules.

Main Methods:

• Implementation of a high-energy pulser to control voltage across ToF-MS deflection plates.
• Precisely deflecting abundant ions to prevent detector saturation.
• Increasing detector operating voltage from 2500 V to 3000 V.

Main Results:

• Achieved a 30-fold increase in detection sensitivity for argon dimers (40Ar2+) in an argon matrix by deflecting 40Ar+ ions.
• Successfully measured larger complex organic molecules in UV-irradiated methanol ice, overcoming previous detection limits.
• Demonstrated enhanced sensitivity for detecting minor species in complex ice matrices.

Conclusions:

• The developed deflection method significantly improves the detection capabilities for complex molecules in UV-processed ices.
• This technique offers a valuable tool for astrochemical research and other fields requiring sensitive analysis of complex mixtures.
• The enhanced sensitivity enables more comprehensive studies of interstellar ice chemistry and the formation of prebiotic molecules.