1. The LINAC  produces a reliable, flexible and accurate radiation beam. 2. For this reason, many high energy electron accelerators are linacs . 3. The next stage of acceleration is linear particle accelerator ( linac  ). 4. The linac  first 200 MeV beam started on December 1, 1970. 5. In 1984, Betti and Derechinsky described a Linac -based radiosurgical system. 6. Today, both Gamma Knife and Linac  radiosurgery programs are commercially available worldwide. 7. As such, impractically long linac  structures were required for higher-energy particles. 8. Linear accelerators ( " linacs  " ) accelerate elementary particles along a straight path. 9. With a Linac , the gantry moves in space to change the delivery angle. 10. The ATLAS linac  section contains 62 resonators, each one of seven different type.