Project

Back to overview

Beschaffung eines Spektrometers basierend auf kontinuierlichen raumtemperatur Quantenkaskadenlasern (CW-RT-QCL) zur Spurengasanalytik

English title A novel cryogenic free spectrometer for high-precision trace gas analysis based on continuous wave quantum cascade lasers
Applicant Emmenegger Lukas
Number 121297
Funding scheme R'EQUIP
Research institution Luftfremdstoffe / Umwelttechnik 500 - Mobility, Energy and Environment EMPA
Institution of higher education Swiss Federal Laboratories for Materials Science and Technology - EMPA
Main discipline Climatology. Atmospherical Chemistry, Aeronomy
Start/End 01.01.2009 - 31.12.2010
Approved amount 135'000.00
Show all

Keywords (8)

tracer gas analysis; ambient air; quantum cascade laser; formaldehyde; glyoxal; spectrometry; trace gas analysis; gas spectrometry

Lay Summary (English)

Lead
Lay summary
Infrared spectroscopy is a powerful technique for the continuous measurement of trace gases in ambient air. A new generation of laser based instruments became available with the development of pulsed, room temperature quantum cascade lasers (RT-QCL) over the last ten years. Their cryogenic free operation is highly important for unattended measurements. However, RT-QCL based systems are often restricted in sensitivity due to the rather broad instrumental linewidth. Furthermore, the limited output power often requires liquid nitrogen cooled detectors to reach the necessary signal to noise ratio. The newest generation of lasers can be operated as continuous wave devices above room temperature (CW-RT-QCL). This is the key to a better spectroscopic performance because of their smaller linewidth, and to Peltier cooled detectors thanks to a significant increase in laser power. Their full potential can, however, only be explored if the quantum cascade laser spectrometer (QCLAS) is fully optimized for these most recent laser devices. The progress of QCLAS is well illustrated by formaldehyde. While this substance was out of reach for cryogenic free laser instruments until now, we expect HCOH to be measurable in ambient air by a novel spectrometer for high-precision trace gas analysis based on continuous wave quantum cascade lasers.HCHO in the atmosphere is one of the key compounds for photochemical reactions leading to the production of radicals and secondary photooxidants. Considering its importance, the database about the distribution of formaldehyde is still limited, which is mainly due to analytical difficulties.Our work will be based on the newest generation of QCLAS based on CW-RT-QCL. Both laser and spectrometer are currently in their final stage of development and, combined, will provide a unique instrument for trace gas analysis. Their first application is planned for continuous measurements of formaldehyde, but other substances (i.e. HNO3, CO, NO2 HONO, HCOOH) may be measured with the same optical platform. This novel QCLAS is a key technology to keep our research groups at the front of current developments in ambient air monitoring, atmospheric chemistry, source identification and source quantification. It is also a powerful infrastructure that will be used in collaboration with many different national and international research groups.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Associated projects

Number Title Start Funding scheme
125336 Kontinuierliche Bestimmung von N2O Isotopomeren in Umgebungsluft mittels Quantenkaskadenlaser-Absorptionspektrometrie 01.11.2009 Project funding

Abstract

Infrared spectroscopy is a very powerful technique for the continuous measurement of trace gases in ambient air. A new generation of laser based instruments became available with the development of pulsed, room temperature quantum cascade lasers (RT-QCL) over the last ten years. Their cryogenic free operation is highly important for unattended measurements. However, RT-QCL based systems are often restricted in sensitivity due to the rather broad instrumental linewidth. Furthermore, the limited output power often requires liquid nitrogen cooled detectors to reach the necessary signal to noise ratio.The newest generation of lasers can be operated as continuous wave devices above room temperature (CW-RT-QCL). This is the key to a better spectroscopic performance because of their smaller linewidth, and to Peltier cooled detectors thanks to a significant increase in laser power. Their full potential can, however, only be explored if the quantum cascade laser spectrometer (QCLAS) is fully optimized for these most recent laser devices. The progress of QCLAS is well illustrated by formaldehyde and glyoxal. While these two substances were out of reach for cryogenic free laser instruments until now, we expect them to be measurable in ambient air by a novel spectrometer for high-precision trace gas analysis based on continuous wave quantum cascade lasers.Formaldehyde (HCHO) in the atmosphere is one of the key compounds for photochemical reactions leading to the production of radicals and secondary photooxidants. Considering its importance, the database about the distribution of formaldehyde is still limited, which is mainly due to analytical difficulties.Glyoxal (CHOCHO) is the smallest alpha-dicarbonyl. It is released by several processes, e.g. biomass burning, fermentation and industrial activities. In addition, glyoxal is formed by the oxidation of anthropogenic and biogenic VOCs. Recent studies indicate that glyoxal may serve as a novel indicator for fast VOC chemistry.We intend to purchase the newest generation of QCLAS based on CW-RT-QCL. Both laser and spectrometer are currently in their final stage of development and, combined, will provide a unique instrument for trace gas analysis. Their first application is planned for continuous measurements of formaldehyde and glyoxal, but other substances (i.e. HNO3, CO, NO2 HONO, HCOOH) may be measured with the same optical platform. This novel QCLAS is a key technology to keep our research groups at the front of current developments in ambient air monitoring, atmospheric chemistry, source identification and source quantification. It is also a powerful infrastructure that will be used in collaboration with many different national and international research groups.
-