CHAMIZO CALVO , Elena

El primer bloque, sobre la descripción de la técnica y de los dos sistemas empleados, comprende los Capítulos 2, 3 y 4. En el Capítulo 2 presentaremos los fundamento s del AMS de baja energía y las características de diseño de sus instalaciones. De esta forma, veremos que un sistema compacto de AMS no es simplemente una versión a escala de uno...

New analytical methods developed at the facilities here, based on two ultra-sensitive mass spectrometry (MS) techniques, inductively coupled plasma sector field mass spectrometer with a desolvator system (Aridus-ICP-SFMS) and accelerator MS (AMS), have been applied in this work for the reassessment of 239Pu in alpha spectrometry (AS) planchets...

A new and highly sensitive method for the determination of 239Pu in human urine has been developed permitting the reassessment of planchets initially prepared for alpha spectrometry (AS) analysis in the context of internal dosimetry. A set of urine samples (volume: 500 mL) was spiked with known quantities of 239Pu, ranging from 2 to 120 fg (4.6...

This study explores for the first time the possibilities that the 233U/236U atom ratio offers to distinguish waters of Atlantic or Pacific origin in the Arctic Ocean. Atlantic waters entering the Arctic Ocean often carry an isotopic signature dominantly originating from European reprocessing facilities with some smaller contribution from global...

En este trabajo se exponen las principales características de las tres técnicas de medida utilizádas y puestas a punto en nuestro laboratorio para la determinación del cociente isotópico 240Pu/239Pu en partículas calientes. La medida de este cociente tiene un alto interés, pues permite caracterizar el origen del plutonio presente en la...

Radioactive residues, in order to be classified as Low-Level Waste (LLW), need to fulfil certain conditions; the limitation of the maximum activity from long-lived radionuclides is one of these requirements. In order to verify compliance to this limitation, the abundance of these radionuclides in the residue must be determined. However,...

The performance of the 1 MV AMS system at the CNA (Centro Nacional de Aceleradores, Seville, Spain) for 236U and 239,240Pu measurements has been extensively investigated. A very promising 236U/238U abundance sensitivity of about 3 × 10−11 has been recently achieved, and background figures for 239Pu of about 106 atoms were reported in the past....

SARA (Spanish Accelerator for Radionuclides Analysis) was the first multielemental AMS facility installed in Spain in 2005. Since then it has been dedicated to the routine analysis of several radionuclides, such as 10Be, 14C, 26Al, 129I and Pu isotopes. Tests have been carried out with other isotopes, such as 41Ca, 236U and 237Np, and several...

There are very few data available of 236U in marine sediment cores. In this study we present the results from the first oceanic depth profile of 236U in a sediment core sampled in the North Atlantic Ocean, at the PAP site (4500 m depth, Porcupine Abyssal Plain (PAP) site, 49°0′ N, 16°30′ W). Additionally, the sediment core was radiologically...

The Centro Nacional de Aceleradores (CNA) hosts a 1 MV accelerator mass spectrometry (AMS) apparatus since September 2005. In order to improve its overall performance, several updates have been made on the existing facility during the last 10 years of operation. In this paper, two modifications conducted in 2015 will be described. To increase...

Continental dust can be suspended and transported by the wind, reaching seawater masses far away from its source. The deposition of the aerosols on the ocean surface can alter the abundance of chemical species in the water column and contribute to element inventories in seafloor sediments. A major Saharan dust intrusion into the Western...

Desde que el Centro Nacional de Aceleradores (CNA) abriera sus puertas en 1997, los investigadores españoles cuentan con un laboratorio de referencia para estudiar la caracterización y modificación de materiales. Uno de los proyectos que allí se desarrollan consiste en medir isótopos radiactivos, lo que con las técnicas empleadas hasta ahora no...

As part of the GEOTRACES Program, six laboratories participated in an intercalibration exercise on several anthropogenic radionuclides of interest. The effort was successful for 239,240Pu activity, 240Pu/239Pu isotope ratio, and 137Cs activity measured in filtered seawater samples from the Bermuda Atlantic Time Series station (BATS) and a site...