Use of an Acetylene-filled Counter for Natural Radiocarbon

Abstract

THE use of natural carbon-14 activity for purposes of archæological dating was suggested by Libby, who used a screen-wall counter¹. The majority of workers in this field have employed the same type of counter in which the carbon is introduced as a solid. However, the counting of carbon-14 in its elementary form appears to be inherently a method of low efficiency, and the alternative use of a counter in which the filling gas is also the sample seems to offer greater scope for improvement. This has been the subject of several recent publications. De Vries and Barendsen² have used carbon dioxide as the sample gas, and Faltings³ has considered the use of methane as an alternative to carbon dioxide. A further improvement may be sought by the use of a gas containing more than one carbon atom per molecule, and to this end an apparatus has been constructed in this laboratory for the counting of natural radiocarbon in the form of acetylene.