10Be as paleoclimatic tracer: initial results from south western Indian Ocean sediments

A new AMS facility at Inter University Accelerator Centre, New Delhi

“…Bi-directional motion of cathode wheel and quick change of cathodes is one of the requirements of AMS measurement for changing between standard, blank and sample quickly to minimize the accelerator and ion source parameters variation effects. Typical 12 C, 9 BeO and 27 Al analyzed current extracted from ion source were found to be 15 lA, 1.1 lA and 100 nA respectively. IUAC Pelletron has both foil and gas stripping arrangement.…”

“…For molecular beams like BeO, the combination of both strippers (gas followed by foil stripper) yields higher transmission [11,12]. At terminal voltage of 10MV, ion beam transmission of 19% is achieved with injected 9 Be 16 O À and 9 Be 3+ current measured after analyzer magnet.…”

“…SRM 4325 was diluted into five different concentrations using 9 Be standard solution SRM 3105a (NIST, Lot No. 892707).…”

“…An aliquot of the leachate ($1 mL) was stored for 9 Be measurement present in the sediment. 9 Be spike (0.1 mL of 1000 ppm solution) was added into rest of the solution and dried completely. Then samples were picked up by 6 M HCl for the anion exchange column [AG-1X8 Resin (200-400 mesh) from Bio-Rad)].…”

“…The new components added to the system are multi-cathode source of negative ion by cesium sputtering (MC-SNICS), recirculating turbos at the terminal for gas stripper [7], offset Faraday cup after the analyzer magnet and +30°AMS beam line, which is composed of a Wien filter, a quadrupole doublet, a double slit, an AMS chamber followed by a gas cell absorber and multi anode gas ionization chamber (MAGIC). Initially we started with 10 Be measurements [8][9][10] and later on 26 Al measurements with standard samples were also performed. It should be mentioned here that this is the first and only AMS facility at present in the country for 10 Be and 26 Al measurements.…”