Rehovot Radiocarbon Measurements III

Abstract

This list contains results obtained between 1981 and 1985. Since the first description of the laboratory (Carmi, Noter & Schlesinger, 1971) the following changes were made. Two proportional counters are now used: 1) 0.5L volume, 0.865 ± 0.023 cpm background, 12.830 ± .134 cpm NBS oxalic acid standard (old); 2) 0.25L volume, 0.484 ± 0.023 cpm background, 6.185 ± .123 cpm NBS oxalic acid standard (old). The passive shield has been increased by 2cm of mercury next to the counters. For anticoincidence, a modular, hand-made gas counter is used. The laboratory was transferred to the ground floor of a 7-storey building. Data acquisition and processing are done with a sealer/buffer built at the institute and an IBM PC computer. Samples are filled into the counters and counted for ca 1000min at least twice. The sample preparation method and counter filling pressure have not been changed.