SRF
overview
TRIUMF’s Superconducting Radiofrequency (SRF) research program is operated as part of a dedicated TRIUMF-based SRF facility, Canada’s only centre for the research, design, testing, and assembly of SRF accelerator technologies.
SRF is at the cutting edge of radio frequency (RF) accelerator technology, enabling the operation of more efficient, powerful, compact and cost-effective accelerators.
For over 20 years, TRIUMF’s SRF team has collaborated with university research and laboratory partners worldwide, and designed, assembled, and maintained TRIUMF’s two SRF accelerators: ISAC-II Superconducting Heavy-Ion linear accelerator (SC-linac) and the ARIEL Electron linac (e-Linac).
As Canada’s only centre for university training and research in SRF technologies, the SRF facility also includes a graduate and post-graduate program of research into next-generation SRF technologies. This includes both micro-and macroscopic research topics, from characterizing and optimizing superconducting properties of potential new alloys to more efficient cavity designs and optimization of surface preparation techniques.
Research area: RF Acceleration
Although acceleration of charged particles can be done from rest using DC voltages, high energy charge particle acceleration typically utilizes radio-frequency electromagnetic waves formed in resonant structures (cavities) either at room temperature using copper or at cryogenic temperature using niobium. The cavities are designed to produce an alternating electric field in the direction of travel.
The particles are grouped into bunches and the spatial distance between bunches and the frequency of the accelerating field are synchronized such that the bunch arrives when the field is in the accelerating phase.
RF acceleration can work from very low energies and velocities to fully relativistic accelerators with the RF structure customized for the particle velocity. Incremental energy increase is achieved either by repeated trips through a few cavities in a circular accelerator or with a single trip through many cavities in a linear accelerator.
Research Area: SRF Technology and Research
While copper is a good electrical conductor, Superconducting RF (SRF) technology represents the forefront of accelerator technology, with an electrical RF surface resistance five orders of magnitude lower than copper.
TRIUMF has two superconducting linear accelerators, a 40MV heavy ion accelerator composed of 40 so-called ‘quarter wave’ accelerating cavities operating near 100 MHz and a 30 MeV electron linac composed of three nine-cell elliptical cavities operating at 1.3GHz. The TRIUMF SRF group designs, builds, and supports the installed accelerators.
The SRF group also engages in both technical and fundamental research and development. The SRF research area offers a rich field for student exploration. Technical studies include the design and fabrication of specialty RF cavities and RF ancillaries both for TRIUMF and for external collaborators. Fundamental studies range from tests of SRF materials using mSR to heat treatments including doping in an induction oven.