- Linac Systems Linear Accelerators for Scientific, Medical, and Industrial Applications Exploiting our patented Rf Focused Drift tube (RFD) Linac Structure, Linac Systems is developing a line of compact, reliable and economical linac-based systems to provide beams of protons and light ions for scientific, medical and industrial applications. The proof-of-principle prototype of the new RFD Linac ...www.linac.com