Update on Beam Commissioning Cornell physicists, working with Brookhaven National Lab, are constructing a new type of particle accelerator called CBETA at Cornell's Wilson Lab. This Energy Recovery Linac (ERL) is a test accelerator built with permanent magnets as well as electro magnets. How it works: CBETA will recirculate multiple beams of different energies around the accelerator at one time. The electrons will make four accelerating passes around the accelerator, while building up energy as they pass through a cryomodule with superconducting RF (SRF) accelerating structures. In four more passes, they will return to the superconducting cavities that accelerated them and return their energy back to these cavities - hence it is an Energy Recovery Linac (ERL). While this method conserves energy, it also creates beams that are tightly bound and are a factor of 1,000 times brighter than other sources. For more details, please contact the Cornell PI Prof. Georg Hoffstaetter. Although linear accelerators (Linac) can have superior beam densities when compared to large circular accelerators, they are exceedingly wasteful due to the beam being discarded after use and can therefore only have an extremely low current compared to ring accelerators. This means that the amount of data collected in one hour in a circular accelerator may take several years to collect in a linear accelerator. In an ERL, the energy is recovered, and the beam current can therefore be as large as in a circular accelerator while its beam density remains as large as in a Linac.
- The Photoinjector that creates and prepares high-current electron beams to be injected into the Main Linac Cryomodule (MLC). The photoinjector in turn consists of a laser system that illuminates a photo-emitter cathode to produce electrons within a high-current DC electron source. These electrons traverses an emittance-matching section to produce a high-brightness beam which is then sent thorough the high-power injector cryomodule (ICM) for acceleration to the ERL's injection energy.
- The Main Linac Cryomodule (MLC) that accelerates the beam through several passages and then decelerates the beam the same number of times to recapture its energy.
- The high-power Beam Stop where the electron beam is discarded after most of its energy has been recaptured.
- 4 Spreaders and 4 combiners with electro magnets that separate beams at 4 different energies after the MLC to match them into the FFAG return loop and then combine them again before re-entering the MLC.
- FFAG Magnets residing in the return loop. These cause very strong focusing so that beams with energies that differ by up to a factor 4 can be transported simultaneously.