ChiefsPlanet - The Beryllium Thread

[31]
Also many high-energy particle physics collision experiments such as the Large Hadron Collider, the Tevatron, the SLAC and others contain beam pipes made of beryllium. Beryllium's low density allows collision products to reach the surrounding detectors without significant interaction, its stiffness allows a powerful vacuum to be produced within the pipe to minimize interaction with gases, its thermal stability allows it to function correctly at temperatures of only a few degrees above absolute zero, and its diamagnetic nature keeps it from interfering with the complex multipole magnet systems used to steer and focus the particle beams.[32]
[edit]Mechanical applications
Because of its stiffness, light weight and dimensional stability over a wide temperature range, beryllium metal is used for lightweight structural components in the defense and aerospace industries in high-speed aircraft, missiles, space vehicles and communication satellites. Several liquid-fuel rockets use nozzles of pure beryllium.[33][34]
Beryllium is used as an alloying agent in the production of beryllium copper, which contains up to 2.5% beryllium. Beryllium-copper alloys are used in many applications because of their combination of high electrical and thermal conductivity, high strength and hardness, nonmagnetic properties, along with good corrosion and fatigue resistance. These applications include the making of spot welding electrodes, springs, non-sparking tools and electrical contacts.
The excellent elastic rigidity of beryllium has led to its extensive use in precision instrumentation, e.g. in gyroscope inertial guidance systems and in support structures for optical systems.[3]
Beryllium was also used in Jason pistols which were used to strip paint from the hulls of ships. In this case, beryllium was alloyed to copper and used as a hardening agent.[35]
[edit]Mirrors
Beryllium mirrors are of particular interest. Large-area mirrors, frequently with a honeycomb support structure, are used, for example, in meteorological satellites where low weight and long-term dimensional stability are critical. Smaller beryllium mirrors are used in optical guidance systems and in fire-control systems, e.g. in the German-made Leopard 1 and Leopard 2 main battle tanks. In these systems, very rapid movement of the mirror is required which again dictates low mass and high rigidity. Usually the beryllium mirror is coated with hard electroless nickel plating which can be more easily polished to a finer optical finish than beryllium. In some applications, though, the beryllium blank is polished without any coating. This is particularly applicable to cryogenic operation where thermal expansion mismatch can cause the coating to buckle.[3]
The James Webb Space Telescope[36] will have 18 hexagonal beryllium sections for its mirrors. Because JWST will face a temperature of 33 K, the mirror is made of beryllium, capable of handling extreme cold better than glass. Beryllium contracts and deforms less than glass—and remains more uniform—in such temperatures.[37] For the same reason, the optics of the Spitzer Space Telescope are entirely built of beryllium metal.[38]
An earlier major application of beryllium was in brakes for military aircraft because of its hardness, high melting point and exceptional heat dissipation. Environmental considerations have led to substitution by other materials.[3]
[edit]Magnetic applications
Beryllium is non-magnetic. Therefore, tools fabricated out of beryllium are used by naval or military explosive ordnance disposal-teams for work on or near naval mines, since these mines commonly have magnetic fuzes.[39] They are also found in maintenance and construction materials near magnetic resonance imaging (MRI) machines. In addition to their being very difficult to remove once magnetic tools have become misplaced inside of the MRI machine, the expulsion of any magnetic items as missiles during ordinary operation of the MRI machine is extremely dangerous.[40]
In the fields of radio communications and powerful (usually military) radars, hand tools made of beryllium are also used to tune the highly magnetic klystrons, magnetrons, traveling wave tubes, etc., that are used for generating high levels of microwave power in the transmitters .
[edit]Nuclear applications
Thin plates or foils of beryllium are sometimes used in nuclear weapon designs as the very outer layer of the plutonium pits in the primary stages of thermonuclear bombs, placed to surround the fissile material. These layers of beryllium are good "pushers" for the implosion of the plutonium-239, and they are also good neutron reflectors, just as they are in beryllium-moderated nuclear reactors.[41]
Beryllium is also commonly used as a neutron source in laboratory experiments in which relatively-few neutrons are needed (rather than having to use an entire nuclear reactor). In this, a target of beryllium-9 is bombarded with energetic alpha particles from a radio-isotope. In the nuclear reaction that occurs, beryllium nuclei are transmuted into carbon-12, and one free neutron is emitted, traveling in about the same direction than the alpha particle was heading.