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.