After the chemical pretreatment the sample material in a quantity corresponding to ca. The schematic layout of AMS spectrometer is presented below adapted from Tuniz et al. As yet, the system has been used to produce graphite targets from plant macrofossils, charcoal, peat, bones, shells and pollen extracts. The reaction is usually complete after 3 to 4 hours. The negative ions of the isotope of interest are accelerated to the terminal of the accelerator at a potential of at least 0. The relative numbers of the atoms of different carbon isotopes in the sample are directly measured and the radiocarbon age is determined. Pressing the graphite target Fe-C powder is pressed into a tablet which is used as a target in the sputter ion source of the accelerator.
Water vapour is frozen in a trap cooled with a mixture of dry ice and alcohol ca.
GLIWICE RADIOCARBON LABORATORY
Fe-C powder is pressed into a tablet which is used as a target in the sputter ion source of the accelerator. CO 2 for gas proportional counters or graphite for AMS. Then CO 2 and H 2 are introduced in stechiometric amounts, with ca. Due to the very small sample amount, considerable effort is put into avoiding contamination with either modern or inactive carbon during the sample preparation. The purpose of the preparation of samples before radiocarbon measurement is the extraction of material that contains indigenous carbon in a quantity sufficient to measure the 14 C content, remove contaminating substances which usually give different age, and produce the medium for appropriate measurement technique e. The schematic layout of AMS spectrometer is presented below adapted from Tuniz et al.