The first three years of DREAMS: Routine operation and developments

The DREAMS (DREsden AMS) facility is based on a state-of-the-art 6 MV accelerator AMS-system [1]. Located at the ion beam centre, the accelerator is also used for ion beam analysis (IBA), material modifications and high-energy ion implantation. Though having no 24/7 availability for AMS, the advantage of a multi-purpose accelerator is the synergy effect with respect to joint technology development and µ-beam IBA for the in-situ identification of elements in problematic cathodes.
Most often measured nuclides are ¹⁰Be, ²⁶Al and ³⁶Cl. The majority of samples is prepared on-site [2], ³⁶Cl in a dedicated laboratory for halide targets. About 600 ¹⁰Be unknowns have been measured for different applications [3]. The mean ratio of processing blanks is as low as 3x10^{-15 10}Be/⁹Be, even when measuring samples with ratios as high as 10^-10–10^-11. However, the mean machine blank is generally a factor of four lower. While analysing 150 ²⁶Al unknowns, machine blanks are as low as 3x10^{-15 26}Al/²⁷Al. Typical high-energy currents (Al³⁺) e.g. for the in-house standard are about 300 nA (mean / 1 h).
One of the original ion sources has been modified for reducing long-term memory for volatiles [4] and yet applied to ~100 unknowns of ³⁶Cl [e.g. 5]. Measurements of ⁴¹Ca are mainly for nuclear decommissioning [6] and cosmochemistry [5] applications.
The high-energy setup is upgraded with a time-of-flight and energy detector system to perform actinide AMS and Super-SIMS [7].
[1] Akhmadaliev et al., NIMB 294 (2013) 5. [2] Merchel et al., AMS-13. [3] Feige et al., Ludwig et al., Ott et al., Rodrigues et al. & Smith et al., AMS-13. [4] Pavetich et al., NIMB, (2014) 10.1016/j.nimb.2014.02.130 & AMS-13. [5] Ott et al., MAPS, subm. [6] Hampe et al., JRNC 296 (2013) 617. [7] Rugel et al., AMS-13.