Laser Isotope Ratiometer


Volcanic degassing is the primary pathway for carbon release from Earth’s interior to its atmosphere. The isotopic composition of outgassed CO2 — specifically the 13CO2/12CO2 ratio — can reveal carbon sources and validate degassing models. Understanding carbon fluxes is critical to the DCO’s Reservoirs and Fluxes Community goals to identify principal deep carbon reservoirs, to determine the mechanisms and rates by which carbon moves among these reservoirs, and to assess Earth’s total carbon budget. Achieving these scientific goals requires technologies and instrumentation that deliver data at relevant cost, temporal, and spatial scales.

To promote technology to help researchers quantify and constrain the relative contributions from various gas sources of volcanic origin, DCO provided partial support in 2013 to develop a novel concept proposed by Damien Weidmann and his collaborators at Rutherford Appleton Laboratory, UK. The prototype Laser Isotope Ratiometer (LIR) employed high-resolution middle infrared (2-20 µm) laser spectroscopy to precisely fingerprint isotopologues, which — owing to their slight mass difference — vibrate with different frequencies that can be resolved by lasers. Desired characteristics for the new instrument included precision, immunity to interferences, and capabilities for non-contact measurements, minimal sample preparation, real-time measurements, and the possibility for absolute concentration measurements — all in a portable format.

With the DCO support, Weidmann and colleagues transformed their laboratory demonstrator into a compact and field deployable instrument capable of real-time in situ measurement of 13CO2/12CO2. To this end, the instrument was ruggedized and reduced in size without loss of sensitivity, and dedicated field electronics were designed for operation using portable power sources. A gas handling system to sample and preserve the unique chemical mixtures expected at different field sites also was designed and implemented. 

image of LIR measuring volcanic gases

Sampling a fumarole at the Solfatara.

A field campaign at La Solfatara, Campi Fleigrei, Italy — in collaboration with Stefano Caliro, Istituto Nazionale di Geofisica e Vulcanologia (INGV) Naples —successfully tested all aspects of the LIR system in 2015. The LIR made a series of isotopic measurements, using different sampling approaches, in tandem with Caliro conducting routine INGV Naples sampling. The data from INGV’s subsequent laboratory isotope mass spectrometry analyses independently verified the LIR’s field measurements.

Once validated as an option for monitoring gas sources, the LIR became the first product of MIRICO Ltd., a company established by Weidmann and colleagues. The LIR’s potential applications for gas analysis extend beyond volcano monitoring and range from high-precision measurements for healthcare (e.g., breath, urine, blood samples) to applications for the energy industries.

MIRICO, which stands for the Mid Infra-Red Instrumentation Company, is a UK-based laser spectroscopy instrumentation company formed in 2015 as a spin-out from the United Kingdom’s Science and Technology Facilities Council (STFC), of which Rutherford Appleton Laboratory (RAL) is part. RAL’s Space Laser Spectroscopy Team, led by Weidmann, developed the technology underpinning the new company. Its formation resulted from over ten years of cutting-edge research and development in the STFC/RAL Space division. The research focused on developing innovative spectroscopic techniques for Earth observation and planetary landers, which evolved into analytical instruments for trace gas analysis that deliver laboratory-standard performance in a compact and sturdy form. The Space Laser Spectroscopy Team consists of senior scientists who have developed a range of techniques that overcome the drawbacks of other technologies. MIRICO Ltd. was formed to commercialize and market these new technologies, and the company continues to grow with additional investors.

MIRICO seeks additional collaborators and opportunities within the scientific community to further improve the LIR’s performance. Although the base instrument is designed for stable isotope analysis, MIRICO can customize development to meet the application requirements of various users.

Principal Investigator

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