AMS of heavy elements with an ECR ion source and the ATLAS linear accelerator

Abstract

Abstract. Understanding the fate of heavy-metal contaminants in the environment is of fundamental importance in the development and evaluation of effective remdlation ad sequestration strategies. Among the factom influencing the transport of these contaminants are their chemical speciation and the chemical and physical attributes of the surrounding medium. Baetena and the extracellular material associated with them are thought to play a key role in determining a contaminant's speciation and thus its mobility in the environment. In addition, the microenvironment at and adjacent to actively metabolizing cell surfaces can be significantly different from the bulk environment. Thus, the spatial distribution and chemical speciation of contruninants and elements that are key to biological processes must be characterized at micron and submicron resolution in order to understand the microscopic physical, geological, chemical. and biological interfaces that determine a contaminant's macroscopic fate.Hard x-my microimaging is a powerful teehnique for the element-specific investigation of complex environmental samples at the needed micron and submicron resolution. An important advantage of this technique results from the large penetration depth of hard X-rays in water. This advantage minimizes the requirements for sample preparation and allows the detailed study of hydmted samples. Thk paper presents results of studies of the spatial dMibution of naturally occurring metals and a heavy-metal contaminant (Cr) in ml near hydmted bacteria (Pseudomonas jhorescens) in the early stages of biofilm developmen~performed at the Advanced Photon Source Sector 2 X-ray microscopy bearnline. ENVIRONMENTAL RESEARCHChemicalcontaminationof soil and groundwater is a universalproblem of immense complexity and greatglobal concern. Sources of contaminationinclude past and present agriculturaland industrialactivities,operationsat nationaldefense sites, and mti.g and manufacturingprocesses. Assessment of thousands of hazardous waste sites m the United Statesalone (including over 1,200 on the National Priority List) has identified the presence of an arrayof toxic substances. These include heavy metals (such as Pb,

Natural and anthropogenic 236U in environmental samples

“…In sediments from the Irish Sea affected by the Sellafield (UK) nuclear fuel reprocessing plant, ratios are 10 À6 to 10 À5 [16,18,19]. In commercial reagents and artificial standard materials, 236 U/U ratios as high as 10 À6 have been measured [16,20]. It is difficult to predict how far anthropogenic 236 U is spread at the yet unexplored sensitivity level of 236 U/U below 10 À6 .…”

Thermal Ionisation Mass Spectrometry

“…169,170 (Accelerator mass spectrometry has pushed the limits for 233 U and 236 U even further. 171 ) Due to its proven analytical performance in nuclear material analysis, TIMS remains pivotal in the certification of nuclear reference materials at leading metrological institutions such as NBL and IRMM (see Section 14.4.8).…”

Toward laser ablation Accelerator Mass Spectrometry of actinides

“…This discrimination is best achieved at ATLAS by using the FMA which has a very large dispersive power and can analyze very heavy ions. A proof of concept and first measurements of rare species in the actinide region were successfully performed for 236 U [14] and 244 Pu [4]. The typical setup consists of accelerating and decelerating a desired ion so that its energy matches the electricrigidity acceptance of the FMA.…”