|Acquisition Program: ||PMA264-Air Anti-Submarine Warfare Systems|| Objective: ||Develop a miniature ultra-cold atom source without active pumps.
|| Description: ||Atom interferometers currently form the basis for state of the art sensors, ranging from gyroscopes to gravity gradiometers. Sensors based on cold and ultra-cold atom sources have been proven to provide significant (orders of magnitude) improvement in sensitivity over currently fielded devices. This effort seeks to enhance the performance of these devices by using quantum degenerate gases. Until now, ultrahigh vacuum systems have been maintained by active vacuum pumps. However, current efforts to miniaturize these sources have been limited by the physical size of these active pumps.
The focus of this effort is to develop a miniature, portable, ultra-cold (Bose condensed or Fermi degenerated) atom source without active pumps although proposed solutions utilizing active pumps which could still meet the required size restrictions may be considered. In order to achieve degeneracy, proposed systems must be able to maintain exceptional vacuum (~10-9 torr). Adding to the challenge, precise control of the dispensing of the atom of choice (typically Rubidium or Cesium) usually necessitates the use of dispensers, rather than ampoules, which can contaminate the vacuum. Although leak-less vacuum cells are by now standard technology, the combination of requiring ultra-high vacuum and precise control on the atom source requires innovative solutions. The cell (“sensor head”) should be no larger than 5cm by 5cm by 5cm. Support electronics and laser systems should be incorporated into standard 19 inch rack-mountable units.
|| ||PHASE I: Develop a vacuum system concept that is capable of maintaining better than 10 -9 torr vacuum with an appropriate alkali dispenser. Demonstrate proof-of-principle by the end of the Phase I base effort.
|| ||PHASE II: Construct a prototype ultra-high vacuum cell with an ultra-cold atom source, based on the design and lessons learned in Phase I.
|| ||PHASE III: Transition the final product to a host of applications that involve precise measurement of gravity gradients (for inertial navigation, tunnel detection, etc), rotation (also for inertial navigation) and magnetic gradients (for anti-submarine warfare).
PRIVATE SECTOR COMMERCIAL POTENTIAL/|| ||DUAL-USE APPLICATIONS: In addition to potential commercial uses for the sensors as outlined above (inertial navigation), gravity gradiometers and magnetic gradiometers can be used for oil exploration. Gravity gradiometers can help find open pockets inside a massive environment, such as pockets inside collapsed buildings or collapsed mines.
|| References: ||1. Gustavson, T.L., Bouyer, P., and Kasevich, M.A., "Precision Rotation Measurements with an Atom Interferometer Gyroscope." APS Phys. Rev. Lett. 78 (1997): 2046 - 2049.
2. Snadden, M.J., McGuirk, J.M., Bouyer, P., Haritos, K.G., and Kasevich, M.A., "Measurement of the Earth's Gravity Gradient with an Atom Interferometer-Based Gravity Gradiometer." APS Phys. Rev. Lett. 81 (1998): 971-974.
3. McGuirk, J.M., Foster, G.T., Fixler, J.B., Snadden, M.J., and Kasevich, M.A., "Sensitive absolute-gravity gradiometry using atom interferometry." APS Phys. Rev. A 65 033608 (2002): 14 pages.
4. Schoser, J., Batar, A., Low, R., Schweikhard, V., Grabowski, A., Ovchinnikov, Yu. B., and Pfau, T., "Intense source of cold Rb atoms from a pure two dimensional magneto-optical trap." APS Phys. Rev. A 66 023410 (2002): 10 pages.|
|Keywords: ||Ultracold Atom Source; Atom Interferometer; Passive Vacuum Pump; Inertial Navigation; Gyroscopes; Gravity Gradiometers|