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The Drop Tower Bremen as a source for atom optical experiments in gravitation-free conditions

Könemann, T., Resch, A., Müntinga, H., Hermann, S., Cláus Lämmerzahl, Rath, H. J., Van Zoest, T., Dittus, H., Seidel, S. T., Ahlers, H., Herr, W., Singh, Y. P., Gaaloul, N., Ernst Maria Rasel, Ertmer, W., Krutzik, M., Lewoczko-Adamczyk, W., Achim Peters, Schiemangk, M., Andreas Wicht, Vogel, A., Sengstock, K., Nadine Meyer, Bongs, K., Theodor W. Hänsch, Jakob Reichel, Kajari, E., Walser, R., Schleich, W. P.

Published Jan 1, 2009• 0 citations
OpenAlex

Abstract

Low gravity provides an outstanding basis for precision measurements in atom optics pursuing multi-disciplines in fundamental physics. On the other hand it leads to an utilization of ultracold quantum matter techniques in unique practical applications. We report on the first establishments of atom optical experiments in the gravitation-free conditions at the Drop Tower Bremen in Germany, a facility of the Center of Applied Space Technology and Microgravity (ZARM). The chosen drop tower has an easy access to low gravity on earth with a daily usage, a more than sufficient time of free fall for experiments in quantum regimes (about 4s in drop mode and about 9s in catapult mode) and a well quality of weightlessness of 10-6g. Our report demonstrates the results of the precursor pilot project ATKAT ("atom catapult") and the current pilot project QUANTUS ("quantum systems under weightlesness") . The pure technological experiment ATKAT could successfully realize a compact and robust setup for trapping and cooling neutral rubidium atoms ( 87Rb) in microgravity conditions. After ATKAT's test accomplishment we have started the parallel developed QUANTUS main pilot projekt to investigate quantum degenerated gases in free fall. The first Bose-Einstein condensate (BEC) in a weightless environment world wide and longest evolution times of the 87Rb BEC up to 1s could be achieved within the science experiment QUANTUS. In respect thereof our collaboration opens further opportunities in atom optics. At least we will give an outlook of the new QUANTUS II project and its supporting project PRIMUS ("precision interferometry with matter waves under weightlessness") aiming on a precise inertial sensor by using an atom interferometer under weightlessness.

Related papers

Konzeption, Entwicklung und Umsetzung von atomoptischen Fallturmexperimenten für den Einsatz unter Schwerelosigkeit am Fallturm Bremen

Thorben Könemann

Since the possibility of trapping and cooling neutral atoms, ultracold quantum gases have shifted boundaries in a growing field of modern physics based on the first observation of Bose-Einstein condensates in 1995 and appreciated by the Nobel Prizes in 1997 and 2001. 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 those quantum systems. In respect thereof weightlessness provides an outstanding basis for such applications and measurements. Motivated by these prospects, many national and international groups have initialized research programs aiming for compact, transportable and ruggedly designed atom-optical experiments, which might be launched in parabolic flights and space applications. Thanks to an easy access to low gravity on earth, realization of quantum degenerated gases in excellent microgravity conditions at the Drop Tower Bremen opened a new kind of perspectives on atom-optical experiments, e.g., to currently achieve longest expansion times of Bose-Einstein condensates within the QUANTUS pilot project (up to one second). Thus, ultracold quantum matter in an environment of weightlessness represents an emerging area of science in quantum engineering with an impressive potential for a future technology and multidisciplinary applications.

•Jan 1, 2010•0 citations

Matter-wave optics with Bose-Einstein condensates in microgravity

Jan Rudolph

Quantum sensors based on the interference of cold atoms have advanced to the forefront of precision measurements in geodesy, metrology and tests of fundamental physics. The ultimate potential of these devices is realized using quantum degenerate atoms in extended free fall. This can be achieved on microgravity platforms such as drop towers, parabolic flights, ballistic rockets, satellites and space stations. The transition to mobile and robust devices that can withstand the demands of these environments comes with many challenges. Quantum sensors need to be scaled down and integrated without compromising their performance. In fact, they need to significantly outpace conventional instruments, since microgravity time is an expensive resource and limited to a few seconds at a time on the most accessible platforms. This thesis describes the construction, qualification and operation of a miniaturized ultracold atom experiment that meets these challenges. The QUANTUS-2 apparatus features a payload weight of 147 kg and a payload volume of 0.3 m^3. It generates Bose-Einstein condensates of 4×10^5 ^87Rb atoms every 1.6 seconds, a flux of ultra-cold atoms that is on par with the best lab-sized devices. Ensembles of 1×10^5 atoms can be created at a 1 Hz rate. It is currently the fastest machine of its kind and achieves the highest atom number of any atom chip setup. The apparatus continuously withstands peak accelerations of up to 45 g during microgravity campaigns at the drop tower facility in Bremen, Germany. Here, the payload has accrued 208 drops and 9 catapult launches over 24 month. The setup is the first atom optics experiment to stand up to the technical demands of catapult operation. Four condensates can be created and observed consecutively during nine seconds of free fall in a single catapult launch. In total, the experiment has been suspended in microgravity for over 17 minutes. With the record source performance, the repetition rate for microgravity experiments with ultra-cold atoms was increased by a factor of four compared to previous devices. The total atom number was increased by a factor of 40, vastly improving the signal to noise ratio for absorption images of spatially extended clouds. The ensembles can be prepared consistently over many weeks of drop tower operation. The variance of the mean center of mass velocity in two observable directions is 7.3 μm/s and 6.9 μm/s. Magnetic lensing techniques were employed to manipulate the expansion of the ensembles. First results yield a residual expansion rate in three dimensions of σ_v = 116.9 ± 13.9 μm/s, which implies a three-dimensional effective temperature of T = 47.6 ± 11.3 pK at an average condensate atom number of N = 93000. These values constitute the best collimation of any atomic ensemble and the most promising source for atom interferometry reported to date. Optimizing the current lensing sequence will reduce the expansion rate further to effective temperatures in the femtokelvin regime. The level of control demonstrated over the condensates is highly relevant for the advancement of matter-wave optics and quantum sensors. Controlling the motion and size of atomic clouds is intrinsically tied to many systematic effects in high precision measurements. QUANTUS-2 will provide a platform to explore and mitigate these limitations on unprecedented time scales of up to seven seconds of free evolution.

•Jan 1, 2016•16 citations

Realization of a magneto-optical trap in microgravity

Kai Bongs, Wiebke Brinkmann, Hansjörg Dittus +17 more

We report on the first realization of magneto-optically cooled atoms in microgravity as a first result of the collaboration project ATKAT (atom catapult). We present the compact and robust setup for cooling and trapping neutral 87Rb atoms in microgravity conditions in the drop tower in Bremen⊥ ⊥www.zarm.uni-bremen.de and discuss the specific requirements the setup has to meet. In particular we present a small size and mechanically stable laser system and discuss the specifics of the ultra high vacuum chamber. A free falling magneto-optical trap (MOT) as realized in this project provides a basis for further experiments which aim at investigating cold quantum matter in microgravity.

Journal of Modern Optics•Nov 10, 2007•3 citations

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Wojciech Lewoczko-Adamczyk, Achim Peters, Tim van Zoest +16 more

Weightlessness promises to substantially extend the science of quantum gases toward presently inaccessible regimes of low temperatures, macroscopic dimensions of coherent matter waves, and enhanced duration of unperturbed evolution. With the long-term goal of studying cold quantum gases on a space platform, we currently focus on the implementation of an 87 Rb Bose–Einstein condensate (BEC) experiment under microgravity conditions at the ZARM drop tower in Bremen (Germany). Special challenges in the construction of the experimental setup are posed by a low volume of the drop capsule (< 1 m3) as well as critical vibrations during capsule release and peak decelerations of up to 50 g during recapture at the bottom of the tower. All mechanical and electronic components have thus been designed with stringent demands on miniaturization, mechanical stability and reliability. Additionally, the system provides extensive remote control capabilities as it is not manually accessible in the tower two hours before and during the drop. We present the robust system and show results from first tests at the drop tower.

International Journal of Modern Physics D•Dec 1, 2007•2 citations

Interferometry with Bose-Einstein condensates in microgravity

Holger Ahlers, Ernst Maria Rasel

Matter-wave sensors are considered to be one of the most promising fields for progress in metrology and fundamental tests. We report on the development of a miniaturized and robust experiment within the QUANTUS collaboration using ultra cold atoms in a free fall environment as a test-bed for matter-wave interferometry on long timescales. Over 200 experiments in microgravity have been performed so far at the ZARM drop tower in Bremen and a BEC was observed after expansion times of up to 1s. The combination of long expansion times and low density samples is beneficial for the application in interferometry. We present the recently implemented interferometer in our chip-based87Rb BEC experiment including on-chip state preparation. Bragg diffraction is used for coherent manipulation, realizing different interferometer schemes. First results on ground and in microgravity are shown.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•May 1, 2011•0 citations

RUBIDIUM BOSE–EINSTEIN CONDENSATE UNDER MICROGRAVITY

Achim Peters, Wojciech Lewoczko-Adamczyk, Tim van Zoest +16 more

Weightlessness promises to substantially extend the science of quantum gases toward presently inaccessible regimes of low temperature, mcroscopic dimensions of coherent matter waves, and enhanced duration of unperturbed evolution. With the long-term goal of studying cold quantum gases on a space platform, we currently focus on the implementation of an 87Rb Bose-Einstein condensate (BEC) experiment under microgravity conditions at the ZARM drop tower in Bremen (Germany). Special challenges in the construction of the experimental setup are posed by a low volume of the drop capsule (< 1 m^3) as well as critical vibrations during capsule release and paek decelerations of up to 50 g during recapture at teh bottom of the tower. All mechanical and electronic components have thus been designed with stringent demands on miniaturization, mechanical stability and reliability. Additionally, the system provide extensive remote control capabilities as it is not manually accessible in the tower for two hours before and during the drop. We present the robust system and show results from first tests at teh drop tower.

WORLD SCIENTIFIC eBooks•May 1, 2009•1 citation
Low gravity provides an outstanding basis for precision measurements in atom optics pursuing multi-disciplines in fundamental physics. On the other hand it leads to an utilization of ultracold quantum matter techniques in unique practical applications. We report on the first establishments of atom optical experiments in the gravitation-free conditions at the Drop Tower Bremen in Germany, a facility of the Center of Applied Space Technology and Microgravity (ZARM). The chosen drop tower has an easy access to low gravity on earth with a daily usage, a more than sufficient time of free fall for experiments in quantum regimes (about 4s in drop mode and about 9s in catapult mode) and a well quality of weightlessness of 10-6g. Our report demonstrates the results of the precursor pilot project ATKAT ("atom catapult") and the current pilot project QUANTUS ("quantum systems under weightlesness") . The pure technological experiment ATKAT could successfully realize a compact and robust setup for trapping and cooling neutral rubidium atoms ( 87Rb) in microgravity conditions. After ATKAT's test accomplishment we have started the parallel developed QUANTUS main pilot projekt to investigate quantum degenerated gases in free fall. The first Bose-Einstein condensate (BEC) in a weightless environment world wide and longest evolution times of the 87Rb BEC up to 1s could be achieved within the science experiment QUANTUS. In respect thereof our collaboration opens further opportunities in atom optics. At least we will give an outlook of the new QUANTUS II project and its supporting project PRIMUS ("precision interferometry with matter waves under weightlessness") aiming on a precise inertial sensor by using an atom interferometer under weightlessness.
Since the possibility of trapping and cooling neutral atoms, ultracold quantum gases have shifted boundaries in a growing field of modern physics based on the first observation of Bose-Einstein condensates in 1995 and appreciated by the Nobel Prizes in 1997 and 2001. 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 those quantum systems. In respect thereof weightlessness provides an outstanding basis for such applications and measurements. Motivated by these prospects, many national and international groups have initialized research programs aiming for compact, transportable and ruggedly designed atom-optical experiments, which might be launched in parabolic flights and space applications. Thanks to an easy access to low gravity on earth, realization of quantum degenerated gases in excellent microgravity conditions at the Drop Tower Bremen opened a new kind of perspectives on atom-optical experiments, e.g., to currently achieve longest expansion times of Bose-Einstein condensates within the QUANTUS pilot project (up to one second). Thus, ultracold quantum matter in an environment of weightlessness represents an emerging area of science in quantum engineering with an impressive potential for a future technology and multidisciplinary applications.
Quantum sensors based on the interference of cold atoms have advanced to the forefront of precision measurements in geodesy, metrology and tests of fundamental physics. The ultimate potential of these devices is realized using quantum degenerate atoms in extended free fall. This can be achieved on microgravity platforms such as drop towers, parabolic flights, ballistic rockets, satellites and space stations. The transition to mobile and robust devices that can withstand the demands of these environments comes with many challenges. Quantum sensors need to be scaled down and integrated without compromising their performance. In fact, they need to significantly outpace conventional instruments, since microgravity time is an expensive resource and limited to a few seconds at a time on the most accessible platforms. This thesis describes the construction, qualification and operation of a miniaturized ultracold atom experiment that meets these challenges. The QUANTUS-2 apparatus features a payload weight of 147 kg and a payload volume of 0.3 m^3. It generates Bose-Einstein condensates of 4×10^5 ^87Rb atoms every 1.6 seconds, a flux of ultra-cold atoms that is on par with the best lab-sized devices. Ensembles of 1×10^5 atoms can be created at a 1 Hz rate. It is currently the fastest machine of its kind and achieves the highest atom number of any atom chip setup. The apparatus continuously withstands peak accelerations of up to 45 g during microgravity campaigns at the drop tower facility in Bremen, Germany. Here, the payload has accrued 208 drops and 9 catapult launches over 24 month. The setup is the first atom optics experiment to stand up to the technical demands of catapult operation. Four condensates can be created and observed consecutively during nine seconds of free fall in a single catapult launch. In total, the experiment has been suspended in microgravity for over 17 minutes. With the record source performance, the repetition rate for microgravity experiments with ultra-cold atoms was increased by a factor of four compared to previous devices. The total atom number was increased by a factor of 40, vastly improving the signal to noise ratio for absorption images of spatially extended clouds. The ensembles can be prepared consistently over many weeks of drop tower operation. The variance of the mean center of mass velocity in two observable directions is 7.3 μm/s and 6.9 μm/s. Magnetic lensing techniques were employed to manipulate the expansion of the ensembles. First results yield a residual expansion rate in three dimensions of σ_v = 116.9 ± 13.9 μm/s, which implies a three-dimensional effective temperature of T = 47.6 ± 11.3 pK at an average condensate atom number of N = 93000. These values constitute the best collimation of any atomic ensemble and the most promising source for atom interferometry reported to date. Optimizing the current lensing sequence will reduce the expansion rate further to effective temperatures in the femtokelvin regime. The level of control demonstrated over the condensates is highly relevant for the advancement of matter-wave optics and quantum sensors. Controlling the motion and size of atomic clouds is intrinsically tied to many systematic effects in high precision measurements. QUANTUS-2 will provide a platform to explore and mitigate these limitations on unprecedented time scales of up to seven seconds of free evolution.
We report on the first realization of magneto-optically cooled atoms in microgravity as a first result of the collaboration project ATKAT (atom catapult). We present the compact and robust setup for cooling and trapping neutral 87Rb atoms in microgravity conditions in the drop tower in Bremen⊥ ⊥www.zarm.uni-bremen.de and discuss the specific requirements the setup has to meet. In particular we present a small size and mechanically stable laser system and discuss the specifics of the ultra high vacuum chamber. A free falling magneto-optical trap (MOT) as realized in this project provides a basis for further experiments which aim at investigating cold quantum matter in microgravity.
Weightlessness promises to substantially extend the science of quantum gases toward presently inaccessible regimes of low temperatures, macroscopic dimensions of coherent matter waves, and enhanced duration of unperturbed evolution. With the long-term goal of studying cold quantum gases on a space platform, we currently focus on the implementation of an 87 Rb Bose–Einstein condensate (BEC) experiment under microgravity conditions at the ZARM drop tower in Bremen (Germany). Special challenges in the construction of the experimental setup are posed by a low volume of the drop capsule (< 1 m3) as well as critical vibrations during capsule release and peak decelerations of up to 50 g during recapture at the bottom of the tower. All mechanical and electronic components have thus been designed with stringent demands on miniaturization, mechanical stability and reliability. Additionally, the system provides extensive remote control capabilities as it is not manually accessible in the tower two hours before and during the drop. We present the robust system and show results from first tests at the drop tower.
Matter-wave sensors are considered to be one of the most promising fields for progress in metrology and fundamental tests. We report on the development of a miniaturized and robust experiment within the QUANTUS collaboration using ultra cold atoms in a free fall environment as a test-bed for matter-wave interferometry on long timescales. Over 200 experiments in microgravity have been performed so far at the ZARM drop tower in Bremen and a BEC was observed after expansion times of up to 1s. The combination of long expansion times and low density samples is beneficial for the application in interferometry. We present the recently implemented interferometer in our chip-based87Rb BEC experiment including on-chip state preparation. Bragg diffraction is used for coherent manipulation, realizing different interferometer schemes. First results on ground and in microgravity are shown.
Weightlessness promises to substantially extend the science of quantum gases toward presently inaccessible regimes of low temperature, mcroscopic dimensions of coherent matter waves, and enhanced duration of unperturbed evolution. With the long-term goal of studying cold quantum gases on a space platform, we currently focus on the implementation of an 87Rb Bose-Einstein condensate (BEC) experiment under microgravity conditions at the ZARM drop tower in Bremen (Germany). Special challenges in the construction of the experimental setup are posed by a low volume of the drop capsule (< 1 m^3) as well as critical vibrations during capsule release and paek decelerations of up to 50 g during recapture at teh bottom of the tower. All mechanical and electronic components have thus been designed with stringent demands on miniaturization, mechanical stability and reliability. Additionally, the system provide extensive remote control capabilities as it is not manually accessible in the tower for two hours before and during the drop. We present the robust system and show results from first tests at teh drop tower.