GA-ASI's Aircraft Systems Group, staying on as non-executive chairman of the company's management committee. Frank Pace, the executive vice president of Aircraft Systems Group, succeeded Cassidy as President of GA-ASI. General Atomics is also developing a Generation IV reactor design, the Gas Turbine Modular Helium Reactor (GT-MHR). In 2010, General Atomics presented a new version of the GT-MHR, the Energy Multiplier Module (EM2), which uses fast neutrons and is a Gas-cooled fast reactor. General Atomics, including its affiliate, General Atomics Aeronautical Systems, is San Diego County's largest defense contractor, according to a September 2013 report by the San Diego Military Affairs Council. The top five contractors, ranked by defense-generated revenue in fiscal year 2013, were General Atomics, followed by Northrop Grumman, General Dynamics-NASSCO, BAE Systems, and SAIC. A separate October 2013 report by the San Diego Business Journal ranked contractors by the number of local employees. The top three contractors were General Atomics, Northrop Grumman, and General Dynamics NASSCO. In September 2020, a $7.4 billion contract for MQ-9 Reaper drones was announced between the U.S. Air Force and General Atomics. The contract calls for the delivery of up to 36 aircraft per year. Leadership In 2020, General Atomics Global Corporation appointed Indian-American defense industry veteran Vivek Lall as its new Chief Executive. This is Dr. Lall's second stint with the company as he has worked with General Atomics from August 2014 to December 2017 before joining Lockheed Martin. Business groups Electromagnetic Systems Group The Electromagnetic Systems (EMS) Group is a supplier of electromagnetic systems and related power equipment for a variety of defense, energy, and commercial transportation applications. EMS has expertise in the design and fabrication of linear motors, superconducting and conventional rotating motors, power inverters, high-voltage DC power distribution systems, and numerous other energy conversion, distribution, and storage systems. EMS is a major factor in applying electromagnetic technologies to aircraft launch and recovery (EMALS and AAG System), projectile launch (Navy railgun), and magnetic levitation transportation systems. Nuclear Technology & Materials (NTM) Advanced fission reactor technology Nuclear fuels and medical isotopes Nuclear Materials Science & Engineering Energy Group Magnetic Fusion Energy DIII-D National Fusion Facility ITER Central Solenoid Fusion Plasma Theory and Computation Inertial confinement fusion technology Affiliated companies General Atomics Aeronautical Systems, Inc. (GA-ASI)GA-ASI's Aircraft Systems Group produces the Predator series of remotely piloted aircraft used in the Kosovo, Iraq, and Afghanistan conflicts. GA-ASI's Reconnaissance Systems Group provides tactical