February 5, 2024

SLAC Power Outage and impact on LCLS

Dear LCLS user community,

I hope you’re all in the final stages of completing your submissions to LCLS Run 23 (due on 21st February!).

In the meantime, I wanted to update you on the status of operations at LCLS following a major storm on 4th February, in which the winds in the Bay Area got up to 100 miles per hour, over 300,000 people lost power to their homes, and local cities declared a state of emergency.

The main power line to SLAC (a 230 kV line) was damaged, requiring the lab to run on its backup line (60 kV) up until today when the full power was restored. It was a major effort to enact these repairs as the road up to the damaged site was impassable due to fallen trees, and obviously there was a complex process at the site itself to ensure the work proceeded safely and robustly. Huge thanks to our facilities team and their contractors for undertaking this work, including tree trimming and removal, and line inspection, repair and switching.

This has meant that the major accelerators at SLAC (LCLS and SSRL) have been out of operation throughout this period. We project that LCLS will be restarted for user operations by Friday of this week (16th Feb). MeV-UED has already been restored and will be fielding users by tomorrow.

It is a rare event for us to have to cancel entire beam times for users, and so we will honor our commitments and reschedule the affected users in the coming months. I appreciate the understanding and flexibility of the local team and our users in accommodating the revised schedule for those that had also to be moved around over this period.

The power outage also impacted our new superconducting accelerator and its cryoplant. Fortunately, the recovery to backup power was in time to ensure there was no lasting impact on these systems, which remained at sufficiently low cryogenic temperatures throughout. We are now in the process of restarting these systems in order to move forward with the beam commissioning program. There is inevitably a knock-on impact to the volume of experiments we can field in Run 22 on the new instruments (TMO and ChemRIXS), and we are working with the relevant user groups to resubmit where needed for Run 23 so that our Proposal Review Panel (PRP) has insight into the full range of candidate experiments.

These power outages are frustrating for us all, particularly with two within the space of a year. The SLAC team is working with the local utility company and assessing onsite options to mitigate the likelihood and impact of future outages to the extent possible, acknowledging that many regions around the world are experiencing an increased frequency of severe weather events.

The latest Run 22 schedule can be found here

I hope this update is useful to you. Please let me know if you have any questions.


Mike Dunne