The CAMECA-ims 1290 ion microprobe is the last addition to the UCLA SIMS lab. This instrument was delivered in August 2015 and then was commissioned in Dec 2015. The UCLA ims1290 is based on the ims1200-series ion optical platform and capable of attaining a mass resolving power (MRP) of up to 5,000 without significant loss of secondary ion intensity permitting isotopic analysis of certain trace elements at high sensitivity (e.g., Pb or intermediate U-series isotopes in accessory minerals). A MRP as high as 50,000 is achievable with decreased transmission. As with all the ims1200-series, it functions as an ion microscope by direct ion imaging of the sample (with ~1 μm lateral resolution), which is a key component for achieving good (~10’s nm scale) depth resolution during depth-profiling (i.e., by eliminating crater edge contributions). For the analysis of negative secondary ions from electrically insulating samples (e.g., O isotopes in silicates or carbonates), a normal incidence electron flood gun provides charge compensation. A five moveable collector ion detection system is operational for isotopic analyses of elements ranging from Li to U. Internal precision for most isotopic ratios in multicollector mode with Faraday cups is on the order of ±0.1‰.
The Hyperion-2 uses an RF generator to produce primary oxygen ions at current densities that are much higher than the CAMECA duoplasmatron was capable of. We demonstrated a critical focus of 20 nA (a typical current used for U-Pb zircon dating) into a 5 μm spot (Liu et al., 2018) in contrast to the ~30 μm spot that would be needed for the duoplasmatron. This is important for analyses that are not sample-limited but instead require sufficiently high secondary ion intensities such that all isotopes can be detected using FCs, enabling high precision.