a b s t r a c tWe developed the use of a porous iron pellet as a catalyst for AMS 14 C analysis of small samples down to ultra-microscale size (10-25 lgC). It resulted in increased and more stable beam currents through our HVEE 4130 14 C AMS system, which depend smoothly on the sample size. We find that both the expected decrease of oxalic acid standards and increase of backgrounds with decreasing sample size, due to increasing influence of contamination, are reproducible. Using a mass-dependent background correction for dead (1.0 ± 0.4 lgC) and modern (0.25 ± 0.10 lgC) contamination, we obtain reliable results for small samples down to 10 lgC and possibly smaller. Due to our low graphitization yield for ultra-small samples (increases from 40% to 80% on average with sample size), we measured graphite standards as small as 3 lgC. The standard deviation of the corrected activity is about 5% for a 10-lgC HOxII standard.Here we report the iron pellet technique, which is new to the best of our knowledge. It is generally applicable for AMS 14 C laboratories that want to measure small samples down to ultra-microscale size. As an illustrative test-case, we analyze 14 C data for IAEA-C5, C7 and C8 samples with masses ranging from 15 to 300 lgC.
Volume 11 RILEM, The International Union of Laboratories and Experts in Construction Materials, Systems and Structures, founded in 1947, is a non-governmental scientific association whose goal is to contribute to progress in the construction sciences, techniques and industries, essentially by means of the communication it fosters between research and practice. RILEM's focus is on construction materials and their use in building and civil engineering structures, covering all phases of the building process from manufacture to use and recycling of materials. More information on RILEM and its previous publications can be found on www.RILEM.net.The RILEM State-of-the-Art Reports (STAR) are produced by the Technical Committees. They represent one of the most important outputs that RILEM generateshigh level scientific and engineering reports that provide cutting edge knowledge in a given field. The work of the TCs is one of RILEM's key functions.Members of a TC are experts in their field and give their time freely to share their expertise. As a result, the broader scientific community benefits greatly from RILEM's activities.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.