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From the Director of LCLS

(Photo - Joachim Stöhr)

As LCLS Director, the key part of my day-to-day job, or "mission," is to enable and support forefront scientific research based on ultrashort, high peak brightness X-rays by a broad user community in a safe environment. Another important aspect of my job—the "vision"—is to keep the Linac Coherent Light Source at the international forefront.

The LCLS mission requires two key competencies: reliable operation of the SLAC linac and user support on the experimental floor. LCLS day-to-day operation is actually defined "bottom-up," that is, it begins with the end user, who requests what is needed for a given experiment in terms of instrumentation and X-ray properties, i.e., the X-ray energy, intensity, pulse length, spot size, polarization, etc. To accommodate the user needs involves staff on the experimental floor as well as the SLAC linac operations team.

At today's ring based X-ray facilities like SSRL, users work hand-in-hand with staff on the experimental floor but the accelerator operations staff typically remains in the background. This is because the operation of storage rings has been mastered with remarkably reliable beam delivery of more than 95% of scheduled time. This will be quite different for LCLS, where the teams on the experimental floor need to be more closely coupled to the main linac control room because experiments are done essentially pulse-by-pulse and adjustments of the accelerator beam that determines the X-ray beam are part of the experiments. This will be accomplished by a core team consisting of experimental floor staff and accelerator operations staff. The novelty is that the staffing will involve two SLAC directorates.

The mission of this core team is to ensure a seamless link from the user to the main control room and to respond to user needs through operational delivery. The core team therefore contains key people from the LCLS Directorate and a few managers who are "matrixed" from the Accelerator Directorate to the LCLS Directorate. Besides their core team role, these managers are responsible for the broader linac operations and maintenance personnel—a large number of people (~200) from the entire Accelerator Directorate. In terms of day-to-day operations, one may thus summarize the interaction of the LCLS Directorate with the Accelerator Directorate this way: the LCLS Directorate represents the users and defines what is needed in terms of beams, and the Accelerator Directorate is responsible to deliver the requested beam.

The Accelerator Directorate also plays a key role in enabling the LCLS vision through innovative accelerator research and development. This think tank aspect greatly helps LCLS remain at the cutting edge. I am already excited about brainstorming with the accelerator scientists about new opportunities such as different linac energies, additional injection points, bunches with different charges, lengths and repetition rates, new undulator types and laser-based beam manipulation techniques.

—Joachim Stöhr
  SLAC Today, July 29, 2009