Existing JLab SRF Capabilities
Facilities
Jefferson Lab’s production and developmental capabilities in SRF reside mostly in the test lab of the SRF Institute—a high-bay, fieldhouse-sized building modified incrementally since being inherited from NASA in the mid-1980s, during Jefferson Lab’s earliest years. These capabilities include:
- Cavity fabrication and electron beam welding capabilities.
- Clean room with integrated chemistry and high-pressure rinsing system.
- An electropolishing facility capable of handling multicell structures to as low as ~750 MHz.
- A dedicated helium refrigerator capable of 300 W at 2 K.
- A vertical test facility containing eight dewars of various sizes, with a dedicated control room for the testing of cavities over a broad range of sizes, geometries, and frequencies.
- A large magnetically shielded (<10 mG) cryomodule test cave with a dedicated control room and RF power sources.
- An extensive surface science and analytical laboratory (including scanning Auger microscope, scanning field emission microscope, transmission electron microscope, and secondary ion mass spectrometer).
- Several high-vacuum, high-temperature (to 1250 ºC) furnaces.
- Modest RF structure testing facilities—tuning, field mapping.
- Material and metallurgical testing facilities (including microscopes and low-temperature materials properties measurements).
- RF laboratory for the development of SRF cavity control systems.
- Experimental niobium thin film deposition system.
It is also important to note that both the CEBAF SRF accelerator and the laboratory’s SRF-driven free-electron laser (FEL) are test beds for the extension of SRF technology to new directions that may enable new applications. For example, high-power energy recovery was demonstrated in the FEL’s SRF driver accelerator and is used in its routine operation as a facility for science and technology users. A 2003 energy-recovery experiment on CEBAF demonstrated that energy recovery could be applied to high input-to-output energy ratios with little beam degradation. As a result, ERLs—energy-recovering linear accelerators, or linacs—are now integral parts of many of the light sources that are being considered and even proposed worldwide, including the Cornell and Daresbury efforts mentioned above. The Jefferson Lab SRF accelerators are directly suitable for testing these and related new concepts, particularly with RF structures for b =1 particles (that is, for speed-of-light particles) and frequencies that are harmonic with 1500 MHz.