ALS Beamline 8.3.1 – The “TomAlberTron”

James Holton standing in front of the 8.3.1 minihutch in the early days

Beamline 8.3.1 at the Advanced Light Source is operated by the University of California San Francisco with the support of generous grants from the National Institutes of Health (R01 GM124149 for technology development and P30 GM124169 for dissemination and user support), Relay Therapeutics Inc., and the Integrated Diffraction Analysis Technologies (IDAT) program of the US Department of Energy Office of Biological and Environmental Research. The Advanced Light Source (Berkeley, CA) is a national user facility operated by Lawrence Berkeley National Laboratory on behalf of the US Department of Energy under contract number DE-AC02-05CH11231, Office of Basic Energy Sciences.

Beamline 8.3.1 is directed by James Holton. Additional hardware and software support are provided by George Meigs and Scott Classen. Scheduling and access is handled by Kathryn Burnett. The Participating Research Team includes UCSF, UC Berkeley, and Relay Therapeutics, and is headed by James Fraser and Robert Stroud.


Pilatus3 S 6M with up to 100Hz data collection.

Beam Characteristics

Beam energy at 8.3.1 is tunable, with a useful range between 6 and 18 keV (2 to 0.7 Å). For native data at 8.3.1 we usually run at 11111 eV (1.116 Å) where we get 1e12 photons/s through a 100 μm aperture. Native beam size is a Gaussian shape with full-width at half-max of 80 x 60 μm (v x h) at the sample. You can aperture this down with 100, 75, 50, 30, 20, and 15 μm holes. These apertures reduce the flux, but the lifetime of the crystal stays the same. What you are throwing away is flux that misses the crystal and ends up as background.

What we do

Tom Alber

Professor Tom Alber passed away in 2014. He spearheaded the construction of Beamline 8.3.1 and ensured that it was a home for innovative structural biology. In 2017, we renamed the beamline the “TomAlberTron” in honor of Tom. We miss him.

Tom Alber in the High Sierras