realization of a magneto-optical trap of rubidium atoms in microgravity (ATKAT)

abstract

Since the possibility of trapping and cooling neutral atoms with laser light, ultracold quantum degenerate gases have shifted boundaries in a growing field of modern physics. The current developments in the domain of atom optics lead to an utilization of ultracold quantum matter techniques in unique practical applications as high-precision atomic clocks, atom interferometer technologies and inertial sensing instruments for gravity field mapping, underground structure detection, autonomous navigation, as well as precision measurements in fundamental physics. The expectations of even higher precision measurements can be performed by arbitrarily extending the time of unperturbed evolution of quantum degenerate systems. In respect thereof weightlessness provides an outstanding basis for such applications and measurements. We report on the first experimental demonstration of a magneto-optical trap (MOT) of rubidium atoms in the environment of weightlessness at the earth-bound short-term microgravity laboratory Drop Tower Bremen, a facility of ZARM ("Center of Applied Space Technology and Microgravity") - University of Bremen. This pilot project was performed within the ATKAT collaboration (''Atom-Catapult'') as a preliminary part of the QUANTUS pilot project (''Quantum Systems in Weightlessness'') pursuing a Bose- Einstein condensation (BEC) of rubidium atoms in microgravity at the drop tower. Furthermore we had successfully accomplished 19 drops with the ATKAT drop capsule in MOT-mode since October 2006 till the end of summer 2007 to investigate ultracold quantum matter feasibility in drop tower conditions. Also we could successfully execute 3 shots with the smaller ATKAT catapult capsule in December 2007 primarily to probe the frequency and power stability of the laser system during the capsule acceleration phase in the new catapult system of the drop tower. In summary the entire ATKAT drop tower inquiries displayed no major structural weakenings by handling an atom-optical experiment at the drop tower whereat the experimental components have to withstand decelerations up to 50g on every drop or shot. For this purpose the goal of the preliminary ATKAT pilot project could be attained to initiate a first basis for extended atom-optical experiments like QUANTUS which aim at realising, observing and investigating Bose-Einstein condensates in microgravity.

• A freely falling magneto-optical trap drop tower experiment; T. Könemann, W. Brinkmann, E. Göklü, C. Lämmerzahl, H. Dittus, T. van Zoest, E.M. Rasel, W. Ertmer, W. Lewoczko-Adamczyk, M. Schiemangk, A. Peters, A. Vogel, G. Johannsen, S. Wildfang, K. Bongs, K. Sengstock, E. Kajari, G. Nandi, R. Walser and W.P. Schleich; Appl. Phys. B 89, no. 4, 431-438 (2007)

• Realization of a magneto-optical trap in microgravity; K. Bongs, W. Brinkmann, H. Dittus, W. Ertmer, E. Göklü, G. Johannsen, E. Kajari, T. Könemann, C. Lämmerzahl, W. Lewoczko-Adamczyk, G. Nandi, A. Peters, E. M. Rasel, W. P. Schleich, M. Schiemangk, K. Sengstock, A. Vogel, R. Walser, S. Wildfang, T. van Zoest; J. Mod. Opt. 54, no. 16 & 17, 2513-2522 (2007)

experiment year: 2007
number of drops: 13
number of catapult flights: 3

experiment year: 2006
number of drops: 8