Documents / Report
This unclassified Defense Intelligence Reference Document from the Defense Intelligence Agency is dated 2 March 2010. It was produced in FY 2009 under the Advanced Aerospace Weapon System Applications (AAWSA) Program. The report reviews work on using positrons as aerospace fuel. It covers air-breathing turbojet and ramjet engines, unmanned aircraft, missiles, single-stage reusable vehicles, positron rockets and a crewed Mars mission, along with how positrons could be produced and stored. It concludes that a first positron-powered flight around the globe could be possible within 10 years.
“Masse”17 pages
UNCLASSIFIED/ }F9A: 9FFI~llk YE'lii 911k>C MSS, and the astronauts descend to the Mars surface on the MSL using a high- thrust variant of the positron rocket engine. Positron Production Positrons are currently produced at particle accelerators worldwide for basic and applications research. For example, the positron-emitting radioisotope Na 22 (2.7 year mean lifetime) is made by bombarding targets with neutrons from a high-energy proton accelerator in the reaction Al 27 (n,x)Na 22 . Capture of these positrons is used to form beams with keV (slow) to MeV (fast) energies. Handling of large radioactive sources results in limits of 106 slow positrons/sec. For intensities up to 1010/sec, bombardment of metal targets with electron beams in the 10- to 100-MeV range is used, followed by collection and acceleration (deceleration) of positrons to form fast or slow beams. In addition, it has recently been shown that slow positron beams of up to 10 11/sec can be realized by converting neutrons in reactors to electron-positron pairs in thin metal foils. Much higher positron currents are being sought in a variety of proposed solutions. Illustrated below are a few of the more promising concepts. First, in 1996, the U.S. Naval Research Laboratory 56 proposed developing an intense source of fast positrons (10 16/sec) utilizing compact electron betatron accelerators. Second, tabletop femtosecond laser-driven positron sources currently under development at the National Ignition Facility (Lawrence Livermore National Laboratory), the Rutherford-Appleton Laboratory (United Kingdom), and the Max Planck Institute (Munich) look promising, although more must be done to demonstrate efficient collection of positrons into beams. Finally, a most important step forward is multi-gigaelectronvolt (GeV) energy electron storage rings being developed for the high-energy physics International Linear Collider (ILC) project that uses undulators in electron beams to create intense photon beams that produce intense (10 14- 16/sec) positron beams by pair production. 57 A schematic drawing from one proposal for the ILC is shown in Figure 18. 58 8- SOLl'C8 Layout of /LC Positron Source Un-ju alUI l:i 8·,••Pd•,, Lllll' 0 tr pra-accel!>rator -5G9V ,. ., Figure 18. Proposed Undulator-Based Positron Source for the International Linear Collider (courtesy KEK, Japan} 59 22 UNCLASSIFIED//F&~ 8FFIIIAL ~:!II!! 8HLY
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Report, from the dia collection. The PDF is mirrored here; the original link is under it. 35 pages are in the text index: search them above, or from the library's search.