• Dressed cavity ready for test in horizontal cryostat

LCLS-II Activities at Fermilab

Fermilab is one of the partner institutions contributing to SLAC Linac Coherent Light Source II (LCLS-II), an electron accelerator project that will produce a high-power free-electron laser for cutting-edge scientific explorations ranging from refined observations of molecules and cellular interactions to innovative materials engineering. Argonne National Laboratory, Cornell University, Lawrence Berkeley National Laboratory and Thomas Jefferson National Accelerator Facility are also partners.

Fermilab is contributing to LCLS-II in the overlapping areas of superconducting radio-frequency (SRF) accelerator technology and cryogenics, critical components that distinguish LCLS-II from SLAC’s current LCLS facility, whose laser production has enabled noted scientific investigations examining the details of biomolecules, as well as important experiments in chemistry, materials science and other areas. The SRF technology used in the new 4 GeV linear accelerator for LCLS-II will allow the pulse rate to increase from 120 pulses per second to 1 million pulses per second. LCLS-II will also add a second X-ray laser beam and room for additional new instruments, greatly increasing the number of experiments carried out each year. The project is supported by DOE-Basic Energy Sciences.

Fermilab’s scope of work for LCLS-II includes:

  • High Q0 R&D program: LCLS-II uses the breakthrough nitrogen-doping technology invented at Fermilab to improve the quality factor (Q0), lowering the both cost of the cryogenic plant infrastructure and the operating costs. The high Q0 R&D program established a recipe to reproducibly achieve the Q0 goal of 2.7×1010.
  • Design, fabricate & test seventeen 1.3 GHz and two 3.9 GHz cryomodules
    • Fermilab was responsible for the design
    • Fermilab and JLab share production of 1.3 GHz cryomodules
    • Fermilab has sole responsibility for 3.9 GHz cryomodule
    • This activity leverages DOE investment made for infrastructure at both labs, using existing infrastructure and adding cryomodule testing capability
  • Design & fabricate cryogenic distribution system: Fermilab experts have worked closely with those at Jefferson Lab on the interface of the cryoplant, cryo distribution and cryomodules to ensure a completely consistent design
  • For above deliverables provide installation and commissioning support at SLAC
  • Assistance with linac accelerator physics and LLRF control

LCLS-II offers the opportunity to bring together on one project the leading U.S. SRF institutions and takes advantage of the existing DOE investment in SRF infrastructure at both Fermilab and Jefferson Lab. It provides an opportunity for cooperation and collaboration between our two labs, using expertise at both labs and to build identical cryomodules at each facility. Cryomodules are tested at the lab where they are assembled and shipped to SLAC for installation in the tunnel. These modules, when lined up end to end, will make up the bulk of the accelerator. Fermilab began delivering the cryomodules to SLAC in January 2018:

The cryomodules are the product of many years of innovation in accelerator technology. The first cryomodule Fermilab developed for this project set a world record in energy efficiency.