|Assessment Report /Dating Laboratory|
Assessment of the University of Helsinki Dating Laboratory
The Dating Laboratory is associated with the University through its status as a section of the National Museum of History. Founded more than 30 years ago, at the time of the rising interest in 14C dating, it has developed into a small yet skilfully operated dating laboratory. It applies radiocarbon dating and tracing, thermo-luminescence (including optically stimulated thermoluminescence) and isotope ratio measurements to a broad variety of research areas.
These areas include traditional archeology and archeometry, as well as recent developments into areas of environmental and climate research, geophysics and geology. Given the limited size of the group (2 scientific staff plus technical support staff) the program and its scientific output can only be characterised as being of high quality. Particularly noteworthy are studies of carbon household and transport, including CO2, in geophysical settings (Finnish peat bogs, Norwegian sea, etc.), and studies in retrospective dosimetry (Chernobyl, Semipalatinsk test sites etc).
In the Panel’s opinion the effectiveness of the group’s 14C dating is severely hampered by the fact that the now dominant technique of accelerator mass spectrometry (AMS) is not locally available. While the respective sample preparation apparatus has been developed and is broadly used for AMS ion-source sample preparation, the samples then need to be sent out for the actual AMS measurements to laboratories at Uppsala and Aarhus. In addition to additional cost, this has the severe scientific drawback that new developments to enhance the AMS technique (including possibly also other radioisotopes of geophysical
significance, such as 10Be) cannot be carried out.
In view of the fact that a low-energy ion accelerator is available in the Physics Department’s Accelerator Laboratory, the Panel strongly supports the intent to make the Dating Laboratory more closely connected with the Department and establish an AMS program at the 5MV tandem accelerator. This is an obvious opportunity to broaden and strengthen the scientific impact of this excellent program.
It is worth pointing out that essentially all projects carried out within this program are of broad interdisciplinary nature. Many have research goals which, while of general importance such as the CO2 production and transport, in the specific study may address issues in geology or environmental science of particular interest to Finland. The interdisciplinary nature of the research should also be an ideal basis for a broad education of correspondingly interested students. This could be accomplished soon at the Kumpula campus. Another important aspect that the Panel notes is the high level of international collaboration in many of the projects. This comes through the broad geophysical range of some of the studies as well as through their specific character (e.g. dosimetry near test sites etc.).
Finally, while adaptation and use of the existing 5MV tandem in the Physics Department’s Acclerator Laboratory provides a major advance in the technical capabilities of the Dating Laboratory’s programs (opening possibly also the application of heavier radioisotopes of geophysical significance, such as 36Cl, due to the fairly high energy of the ion beams from the 5MV machine) truely state-of –the-art, i.e. precise, 14C dating via AMS would benefit from a smaller yet dedicated AMS apparatus. Costs of such a facility are not negligible. But the potential payoffs, given the broad range of applications and opportunities of interdisciplinary research, in the Panel’s opinion seem well worth the effort towards securing such a facility as the Accelerator Laboratory.
Because of these instrumental shortcomings the Panel can only rate the present activities of this group on a total level of Grade 5 being sure, however, that a Grade 6 will be justified as soon as more modern equipment/methods have been introduced. The work of the group is of high quality within the limitations of the present facilities.