Initial Results with Low Energy Single Stage AMS

Abstract

The National Electrostatics Corporation has built and tested a prototype low energy, open-air, single stage carbon accelerator mass spectrometry (AMS) system (patent pending). The configuration tested has a standard 40-sample, multi-cathode SNICS source on a 300-kV deck. The beam is mass analyzed before acceleration to a gas stripper located at ground. The 14C+ ions are separated from 13C+ and 12C+ arising from the molecular breakup by a 90° analyzing magnet immediately after the gas stripper which acts as a molecular dissociator. The 14C+ beam passes through an electrostatic spherical analyzer before entering the particle detector. The observed 14C/12C precision is better than 5% with a sensitivity of better than 0.05 dpm/gmC. A first single stage AMS system has been ordered. The configuration of this system will be discussed.

14CO2 dispersion around two PWR nuclear power plants in Brazil

“…Certified NBS oxalic acid was used as a reference material, and 14 C-free anthracite was used as a reference for background values of the sample preparation and accelerator system. The analytical precision was better than 5& and the sensitivity better than 0.05 dpm/gC (Schroeder et al, 2004), corresponding to 0.8 mBq 14 C/mgC. Analytical errors of the samples in this study were smaller than 3%.…”

“…The SSAMS employed is described by Synal et al (2000), Schroeder et al (2004) and Skog (2007). The elemental carbon samples were pressed into an aluminum holder and placed in the ion source of the accelerator, which can hold up to 40 samples.…”

14C content in vegetation in the vicinities of Brazilian nuclear power reactors

“…A sub-sample of ground material (15 mg) was mixed with approximately 200 mg of copper oxide, combusted to CO 2 in an evacuated graphitization line and reduced to elemental carbon (Stenström, 1995). A few milligrams of the elemental carbon were then pressed into aluminum sample holders and placed in the ion source of a single stage accelerator mass spectrometry system (SSAMS) (Synal et al, 2000;Schroeder et al, 2004), at the GeoBiosphere Science Centre, Lund University, Sweden (Skog, 2007). The 14 C activities of the samples were obtained from the SSAMS analysis, which has a precision of 5& and a sensitivity better than 0.05 dpm/g C or 0.8 mBq/mg C (Schroeder et al, 2004).…”

Performance Evaluation of the New AMS System at Accium BioSciences

“…The single-stage, 250-kV acceleration unit (Schroeder et al 2004) was also considered but later discarded as at the time there was no sufficient independent validation that it could provide the desired machine background level.…”