An inclusive process involving ALS and ALS-U staff, the ALS user community, and external advisory committees was undertaken to select the flagship insertion-device beamlines that will be the first to take full advantage of the soft x-ray coherent flux of the upgraded source. These beamlines will join existing ALS beamlines to form the full complement of capabilities that will be available at the upgraded ALS.
Two new beamlines will be built:
- a soft x-ray beamline in Sector 10, dubbed “FLEXON,” whose high-brightness coherent flux and multiple complementary techniques will probe the roles of multiscale heterogeneity in quantum materials; and
- a tender x-ray beamline in Sector 8, whose coherent scattering and scanning spectromicroscopy capabilities will address challenges at the frontiers of diverse scientific areas, ranging from soft condensed matter and biomaterials to energy science and Earth and environmental sciences.
Two existing soft x-ray beamlines in Sector 7 will be upgraded:
- COSMIC (7.0.1), which will leverage the full brightness and coherence of the upgraded ALS to perform zone-plate-based microscopy, ptychography, and 3D tomography with an up to hundred-fold increase in measurement speed and an improvement in spatial resolution down to 1 nm; and
- MAESTRO (7.0.2), which will take full advantage of the improved coherence of the upgraded ALS to improve the angle-resolved photoemission spectroscopy (ARPES) collection efficiency by more than an order of magnitude, enabling much better spatial resolution, faster measurements, and more comprehensive data sets for materials discovery.
These beamlines were selected from among a number of strong proposals put forward by teams of ALS scientists, leveraging critical input from the user community. Several advisory committees provided feedback that informed the outcome, most notably an ad hoc committee of external experts who thoughtfully evaluated the proposals for scientific importance, relevance of ALS-U characteristics and potential world leadership, technical feasibility and fit to project resources, and strength of the relevant user community and expected productivity.
The selection criteria for determining these beamlines were:
- Scientific importance
- Relevance of ALS-U characteristics and potential world leadership
- Technical feasibility and fit to project resources
- Strength of the relevant user community and expected productivity