High Energy Lasers Green, David 2/16/2016 David Green 85 NW Sleret Ave Gresham, Oregon david.green35@verizon.net 503-492-2108 High Energy Lasers used as Weapons David Green Advancements in technology has brought about many changes in our everyday lives. Some of these changes are beneficial and some are not. In our race for advancement, we have developed many weapons, none of them as formidable as the laser. Lasers have great potential in industry, surgery and communications. To understanding how society has advanced towards high-energy lasers: a better understanding of their development and functionality is needed. Lasers come in different forms and construction. However, all lasers contain an energized substance that has the properties to intensity the light passing through it. This substance can be made from a variety of mediums. The mediums can be in any of the principle states such as solid, liquid or gas. These mediums must have the ability to store energy until it is released as light. The variation of substance establishes the medium’s factor. This factor contributes to the lasers amplification, along with the wavelength and intensity of the incoming light, and the length of the medium. Figure 1 diagram of a laser in operation 1 High Energy Lasers Green, David 2/16/2016 To increase the intensity of the light beam that is passing through the medium, energy must be added. The energy is supplied by an additional source. The process is known as “pumping.” The photon’s energy (E) is determined by its frequency (V) and Planck’s constant (h). Photon emission occurs when the electron drops from one state to a lower state. The energy source causes the electrons in the medium to become excited. While absorbing the energy the electrons will climb into a higher state. This state is unstable and the electrons will fall back to the lower state, however they will emit photons. The photons will travel in a multitude of directions. On each end of the medium are attached mirrors, one of which has a lesser reflective property than the other. Some of the photons strike the mirrors and are reflected back along the length of the medium. Figure 2 Photon building up energy Lasers operate at relative wavelengths; in appendix A is a chart of laser types and their corresponding wavelengths. What makes a high energy laser (HEL)? When laser energy is more that 1 Joule/pulse, and the average power exceeds 100 Watts, then the laser is considered high energy. Actual systems develop up to 100,000 Joules, and an average power of 1,000,000 Watts. The peak power on the pulsed lasers may even exceed 10,000,000,000 Watts. At the High Energy Laser Systems Test Facility (HELSTF) located in White Sands Missile Range, New Mexico, resides the Mid Infrared Advanced Chemical Laser (MIRACL), the United States' most powerful laser. The Mid-Infrared Advanced Chemical Laser (MIRACL) was the first megawatt-class, continuous wave, chemical laser built in the free world. It is a deuterium 2 High Energy Lasers Green, David 2/16/2016 fluoride (DF) chemical laser with energy spectra distributed among about 10 lasing lines between 3.6 and 4.2 microns wavelength. It remains the highest average power laser in the US. MIRACL operation is similar to a rocket engine in which a fuel (ethylene, C2H4) is burned with an oxidizer (nitrogen trifluoride, NF3). Free, excited fluorine atoms are one of the combustion products of MIRACL’s exhaust. Just downstream from the combustor, deuterium and helium are injected into the exhaust. Deuterium combines with the excited fluorine to give excited deuterium fluoride (DF) molecules, while the helium stabilizes the reaction and controls the temperature. The laser's resonator mirrors are wrapped around the excited exhaust gas and optical energy is extracted. The cavity is actively cooled and can be run until the fuel supply is exhausted. The laser's output power can be varied over a wide range by altering the fuel flow rates and mixture. This laser produces a beam in the resonator is approximately 21 cm high and 3 cm wide. Beam shaping optics are used to produce a 14 cm square beam shape, which is propagated through the rest of the beam train. MIRACL ready for action 3 High Energy Lasers Green, David 2/16/2016 A Beam Director is mounted on top and consists of a large aperture (1.8 meter) gimbaled telescope with optics to point the MIRACL at the target. The high power clear aperture is 1.5 meters. The remaining 0.3 meters is normally reserved for a tracker using the outer annulus of the primary mirror. The system is extremely agile and capable of high rotation and acceleration rates. The targeting device (SLBD) weighs 28,000 pounds, of which 18,000 are on the movable portion. The SLBD can also be used as a sensor platform. The telescope is capable of focusing from a minimum range of 400 meters to infinity. A suite of infrared and visible sensors on the top of the gimbal (off axis from the HEL aperture) is used to acquire and track the target. These sensors look through a 40 cm telescope that can focus over the same range as the SLBD telescope and also correct for parallax between the two lines of sight. Boresight between the SLBD telescope and the sensor is maintained by an automatic laser alignment system. In addition, an aperture-sharing element in the high power beam path makes it possible to track a target through the full 1.5 meter telescope aperture even when the high power beam is propagating. Artist rendering of the SLBD These elements have been combined into an integrated system that can acquire and track targets at extended ranges, accept a very high energy beam, focus and aim the beam on a moving target, and keep this beam at the same position as long as necessary to destroy or disable the target. The SLBD has successfully engaged five BQM-34 drones as well as a supersonic Vandal missile, all at tactically significant ranges. 4 High Energy Lasers Green, David 2/16/2016 This development has brought the army and air force new weapons. The Airborne Laser (ABL) weapon system consists of a high-energy, chemical oxygen iodine laser (COIL) mounted on a modified 747-400F (freighter) aircraft to shoot down theater ballistic missiles in their boost phase. A crew of four, including pilot and co-pilot, would be required to operate the airborne laser, which would patrol in pairs at high altitude, about 40,000 feet, flying in orbits over friendly territory, scanning the horizon for the plumes of rising missiles. Capable of autonomous operation, the ABL would acquire and track missiles in the boost phase of flight, illuminating the missile with a tracking laser beam while computers measure the distance and calculate its course and direction. After acquiring and locking onto the target, a second laser, with weapons-class strength, would fire a three to five second burst from a turret located in the 747's nose, destroying the missiles over the launch area. Artist rendering of THEL in action 5 High Energy Lasers Green, David 2/16/2016 The U.S. Army Space and Strategic Defense Command is working on a new active defense weapon system concept to enhance protection for combat forces and theater level assets for the Force XXI Army. The mobile Tactical High Energy Laser, or THEL, weapon system would provide an innovative solution for the acquisition and close-in engagement problems associated with so-called "dumb munitions" -- a primary concern because counter-battery fire may not be an option in densely populated areas. In its first live warhead test, the Tactical High Energy Laser (THEL) system intercepted and destroyed an armed Russian-made Katyusha rocket within seconds of its launch at the White Sands Missile Range. The system detected the 10-foot-long, 5-inch-diameter rocket with its radar before shooting it down at the speed of light with any difficulty. The army’s LBL program utilizing the THEL data. Given the advancements in technology and development in high-energy lasers, military defense weapons of war would naturally follow. The research into HEL is mainly 6 High Energy Lasers Green, David 2/16/2016 funded by the federal government. This double edge sword has given industry opportunities that would never have been available. Research continues, weapon development along side gives America the advancement in industry to compete in today’s global economy Star wars program SBHEL in construction MIRCLE night test at White Sands 7 High Energy Lasers Green, David 2/16/2016 Appendix A Wave Lengths Of The More Common Laser Types Wave Laser Type Media Length (s) Excimer Gas Lasers Argon Fluoride Nanometers (UV) 193 nm (UV) 222 nm Krypton Fluoride (UV) 248 nm Xenon Chloride (UV) 308 nm Xenon Fluoride (UV) 351 nm Nitrogen (UV) 337 nm Helium Cadmium (UV) 325 nm Krypton Chloride Gas Lasers (Violet Helium Cadmium 441 nm ) Argon (Blue) 488 nm (Gree Argon 514 nm n) Krypton (Blue) 476 nm (Gree Krypton 528 nm n) Krypton (Yello 568 nm 8 High Energy Lasers Green, David 2/16/2016 w) Krypton (Red) 647 nm (White Xenon Multiple ) (Gree Helium Neon 543 nm n) (Yello Helium Neon 594 nm w) (Oran Helium Neon 612 nm ge) Helium Neon (Red) 633 nm Helium Neon (NIR) 1,152 nm Helium Neon (MIR) 3,390 nm Hydrogen Fluoride (MIR) 2,700 nm Carbon Dioxide (FIR) 10,600 nm (Gree Metal Vapor Lasers Copper Vapor 510 nm n) (Yello Copper Vapor 570 nm w) Gold Vapor (Red) 627 nm 9 High Energy Lasers Green, David 2/16/2016 (Gree Doubled Nd: YAG 532 nm n) Neodymium: YAG (NIR) 1,064 nm Erbium: Glass (MIR) 1,540 nm Erbium: YAG (MIR) 2,940 nm Holmium: YLF (MIR) 2,060 nm Holmium: YAG (MIR) 2,100 nm (Red) 694 nm Chromium Sapphire (Ruby) 840-1,100 Titanium Sapphire (NIR) nm 700-815 Alexandrite (NIR) nm 570-650 Dye Lasers Rhodamine 6G (VIS) nm (Gree Coumarin C30 504 nm n) Semiconductor Gallium Arsenide (GaAs) (NIR) 840 nm Gallium Aluminum (VIS/ 670-830 Lasers Arsenide NIR) nm 10 High Energy Lasers Green, David 2/16/2016 Work Cited US Army Space and Missile Defense Command, “High Energy Laser System Test Facility, 03/09/2003,www.smdc.army.mil Defense Department, “Tactical High Energy Laser THEL system” 03/09/2003, www.defenseupdate.com/directory/THEL.htm Foundation for Advancement in Science, “Tactical High Energy Laser” 03/07/2003, www.fas.org/spp/starwars/program/thel/htm Foundation for Advancement in Science, “Laser Technology” 03/07/2003, www.fas.org/spp/starwars/program/nssrm/categories/lt.htm Robert Aldrich, ”Laser Fundamentals”, 03/07/2003, www.fas.org/man/dod101/navy/doc/laser/fundamentals.htm John Gormally, “Laser Tutorial”, 03/07/2003, http://members.aol.com/WSRNet/tut/tx.htm 11