Radiocarbon: detection, contamination, and determination

My PhD research deals with radiocarbon, the natural radioactive isotope of carbon, known for its application in dating. The first and main part was the exploration of the capabilities of a new, potentially revolutionary technique to measure radiocarbon. This technique, ICOGS (IntraCavity OptoGalvanic Spectroscopy), much cheaper and easier than the accelerators presently in use, was first published as successful for radiocarbon detection by the Murnick group, Rutgers University, USA. Motivated by their results, we collaborated with them in the development and improvement of ICOGS in Groningen. However, after more than two years of experiments, we had to conclude that the results claimed by the Murnick group were not real. We have finally published these -negative- results in the journal Analytical Chemistry ("ICOGS Not Suitable for Ambient Level Radiocarbon Detection"), to discredit the technique and warn other research groups. So far, however, Murnick et al have not given up their claim. The second project aimed at improving the accuracy of radiocarbon measurements close to the age limit of the method (>40,000 years). We learned that samples stored in certain form and condition could be severely affected by contamination with "modern" carbon. We published our understandings and recommendations concerning ways to minimize sample contamination in the journal Radiocarbon. The third project demonstrated radiocarbon measurements on ultra-small stratospheric CO2 samples (altitude 12-28 km) collected using an ingenious new sampling method, "AirCore", developed at NOAA. We successfully demonstrated that extraction and radiocarbon measurements of such small samples are feasible and that the sampling method is promising