Leibniz laboratory for radiometric dating
After subsequent magnetic and electrostatic analysis, the ions are identified in an ion detector.The schematic layout of AMS spectrometer is presented below (adapted from Tuniz et al., 1998): Abbreviations used on the figure: IS1, IS2 - two ion sources used for different elements/applications or to increase the throughput L1-L6 - electrostatic or magnetic lenses ESA1, ESA2 - electrostatic analysers PA - pre-acceleration of ions M1, M2 - magnets AT-, AT - acceleration tubes for negative and positive ions, respectively HV - high-voltage terminal SC - stripping channel D - detector Compact Carbon AMS at Pozna Radiocarbon Laboratory, Poland (also in Polish).
charcoal, seeds, leaves, wood, and sediments), carbonates, and bones can be dated.
For bones the collagen is extracted according to the modified Longin's method (see poster) After the chemical pretreatment the sample material in a quantity corresponding to ca.
1mg of carbon is placed into a quartz tube with copper dioxide (the source of oxygen needed for combustion) and silver wool (for the removal of gaseous sulphur and chlorine compounds). is reduced to graphite during the reaction with hydrogen at the temperature of 600-630°C (dependent on the reduction rate for a given sample) in the presence of iron as a catalyst.
Identifiable samples (macrofossils) with high carbon contents are preferred over sediments and soils.
For high precision we recommend at least 1 mg of carbon after chemical preparation (see: Pre-treatment procedures).