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Due to the good decay modes and suitable half-life, 89Zr is widely used in the field of immune-PET imaging. The objective is to develop a new target system suitable for cyclotron nuclide production and to obtain a new method for batch production of 89Zr. Herein, two kinds of coin targets were designed and developed based on C30 cyclotron solid target system, and superior coin target structures were determined through irradiation verification. The yttrium foil was assembled in the coin target plate, then irradiated by protons in C30 cyclotron for about 2-4 h. The initial proton energy was 16.5 MeV, and the proton beam was decayed by a proton beam degrader loaded with carbon films of varying thicknesses. The secondary beam of suitable proton energy irradiated the target. The irradiated yttrium foil was moved into the target dissolution tank, the stages of target dissolution, separation and purification were executed sequentially through an automatic separation apparatus loaded hydroxamic acid resin. Finally, the 89Zr solution was collected and tested for the radionuclide purity, radiochemical purity and element impurity contents respectively. In coin target verification, the direct-cooling coin target shows better thermal conduction properties and the yttrium foil remains intact with a nearly perfect beam shape after bombardment. It proves that the direct-cooling coin target has the ability to withstand long-term beam bombardment and satisfies the production prerequisites for 89Zr. A preferred range of beam energy is determined by irradiation experiments. The beam energy could be controlled within 14.5-12.4 MeV by using 0.3-0.6 mm carbon films. By this means, the radioactive impurities such as 88Zr and 88Y decrease significantly and the radionuclide purity of 89Zr is higher than 99.9%. A stable, automated process for the separation and purification of 89Zr is achieved by separation experiments. These test results show that the production capacity of 89Zr could reach 5 GBq. The radiochemical purity of 89Zr is higher than 97%. While the contents of main element impurities are all less than 2.5 μg/GBq. In this study, the 89Zr production technology is stable and reliable. 89Zr nuclide is successfully produced by the coin target system and automatic separation device. These systems have the potential to expand the production of numerous radionuclide. The large-scale supply of 89Zr is realized for the research and development of 89Zr labelled radiopharmaceuticals in China.

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We assess if variations in the in situ cosmogenic 26Al/10Be production ratio expected from nuclear physics are consistent with empirical data, knowledge critical for two-isotope studies. We do this using 313 samples from glacially transported boulders or scoured bedrock with presumed simple exposure histories in the Informal Cosmogenic-nuclide Exposure-age Database (ICE-D) from latitudes between 53°S to 70°N and altitudes up to 5000 m above sea level. Although there were small systematic differences in Al/Be ratios measured in different laboratories, these were not significant and are in part explained by differences in elevation distribution of samples analyzed by each laboratory. We observe a negative correlation between the 26Al/10Be production ratio and elevation (p = 0.0005), consistent with predictions based on the measured energy dependence of nuclear reaction cross-sections and the spatial variability in cosmic-ray energy spectra. We detect an increase in the production ratio with increasing latitude, but this correlation is significant only in a single variate model, and we attribute at least some of the correlation to sample elevation bias because lower latitude samples are typically from higher elevations (and vice versa). Using 6.75 as the 26Al/10Be production ratio globally will bias two-isotope results at higher elevations and perhaps higher latitudes. Data reported here support using production rate scaling that incorporates such ratio changes, such as the LSDn scheme, to minimize such biases.

Abstract: MEGAPIE, the first liquid metal target irradiated by a proton beam at the MW power level, was successfully operated in 2006. A continuous beam of 575MeV protons with a current up to 1.35mA irradiated the liquid lead–bismuth target placed in the SINQ target location at PSI (Switzerland) for a period of 4 months. The activation of the lead–bismuth irradiated in MEGAPIE has been investigated. Experimental cross-sections and evaluated data available for neutron- and proton-induced reaction cross-sections at incident energies from 10−5 eV to 600MeV, and results of nuclear model calculations have been used to obtain nuclear reaction rates. Calculated nuclide and gas production rates are compared with calculations using the MCNPX and FLUKA Monte Carlo codes. The total activation of the LBE agrees well with the other codes. Discrepancies with FLUKA and MCNPX are mainly in two mass regions, where experimental data are scarce: the region 30

We assess if variations in the in situ cosmogenic 26Al/10Be production ratio expected from nuclear physics are consistent with empirical data, knowledge critical for two-isotope studies. We do this using 313 samples from glacially transported boulders or scoured bedrock with presumed simple exposure histories in the Informal Cosmogenic-nuclide Exposure-age Database (ICE-D) from latitudes between 53°S to 70°N and altitudes up to 5000 m above sea level. Although there were small systematic differences in Al/Be ratios measured in different laboratories, these were not significant and are in part explained by differences in elevation distribution of samples analyzed by each laboratory. We observe a negative correlation between the 26Al/10Be production ratio and elevation (p = 0.0005), consistent with predictions based on the measured energy dependence of nuclear reaction cross-sections and the spatial variability in cosmic-ray energy spectra. We detect an increase in the production ratio with increasing latitude, but this correlation is significant only in a single variate model, and we attribute at least some of the correlation to sample elevation bias because lower latitude samples are typically from higher elevations (and vice versa). Using 6.75 as the 26Al/10Be production ratio globally will bias two-isotope results at higher elevations and perhaps higher latitudes. Data reported here support using production rate scaling that incorporates such ratio changes, such as the LSDn scheme, to minimize such biases. [ABSTRACT FROM AUTHOR]