Jan-Olof Lill

High specific activity 61Cu via 64Zn(p,α)61Cu reaction at low proton energies

The PET radionuclide (61)Cu is accessible through several nuclear reactions. Besides the common production route via (61)Ni(p,n)(61)Cu the (64)Zn(p,α)(61)Cu reaction offers some advantages. Especially the comparatively cheap enriched (64)Zn makes this process economical. For fast product purification and recycling of target material an ion exchange cascade was developed. In addition a separation technique with a copper selective resin was tested. (61)Cu with specific activities up to 1000 GBq/μmol was produced with these methods.

Thick-Target PIXE Analysis of Trace Elements in Wood Incoming to a Pulp Mill

Summary Trunk-wood samples of wood raw material incoming to a pulp mill were analysed by thick-target particle induced X-ray emission (PIXE). The tree species studied were pine and spruce from Finland, birch from Finland and Poland and eucalyptus from Uruguay. The wood samples were dry ashed to 550 °C prior to the analysis in order to increase the sensitivity of the method. The method was calibrated and validated using some wood based certified reference materials. The elements determined with the method were P, S, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Pb, Sr, Rb, Ba and F. The concentrations of the main elements P, S, K, Ca and Mn exceeded 50 ppm in most wood samples. The concentrations of heavy metal ions like Cu, Ni and Pb in the samples studied were below or close to 1 ppm. The ash content of birch, pine and spruce wood were in the range 0.2–0.4% and that of eucalyptus ca 0.5%.

Spatial modeling of sediment transfer and identification of sediment sources during snowmelt in an agricultural watershed in boreal climate

Sediment transfer patterns during snowmelt were studied in a small Finnish agricultural watershed. Erosion rates were high as a consequence of high runoff volumes over saturated soil that partly lacked vegetation cover. Automatic high-frequency monitoring data of sediment and phosphorus concentrations in stream showed a clock-wise hysteresis loop as a dominant pattern. GIS-based modeling of runoff and soil erosion, using LiDAR DTM data, suggested that runoff and erosion mostly came from cropland that had the highest sediment contribution index. Also sediment fingerprinting with Cesium-137 suggested cropland and stream bank were the most important sources of suspended sediments in streams. Because a major part of annual sediment transfer takes place during snowmelt, it is a critical period for annual losses of pollutants. Management practices that minimize springtime sediment and pollutant losses from cropland would be needed to make a marked impact on annual pollution transfer to stream waters.

Determination of 68 Ge-trace activities in 68 Ga eluates from a 68 Ge/ 68 Ga generator using X-ray spectrometry with a gas proportional counter

The aim of this study was to introduce a new concept for measuring the remaining radioactivity in the ⁶⁸Ga eluate or in the final radiopharmaceutical product. ⁶⁸Ge decays to ⁶⁸Ga through electron capture (EC, 100%). Using the 9.24 keV K X-rays of ⁶⁸Ga following the EC of ⁶⁸Ge the remaining ⁶⁸Ge radioactivity in the ⁶⁸Ga eluate can be measured with a gas proportional counter.