Atomic Beams in Space R. Ruffieux, S. Lecomte, S. Zivanov, D. L. Boiko A progress in a series of projects supported by ESA on optically pumped Cesium beam clock technology for space applications is reported. Such frequency st<strong>and</strong>ard will be employed in the atomic clock ensemble at GNSS Galileo satellites of second generation. The first generation of satellites of the European Global Navigation Satellite System (GNSS) Galileo will bring an atomic clock ensemble with two Passive Hydrogen Maser (PHM) clocks for the long-term time keeping <strong>and</strong> two Rubidium Atomic Frequency St<strong>and</strong>ard (RAFS) as clockwork during a swap between PHMs. Both technologies were developed by the former Neuchatel Observatory (now Time & Frequency at <strong>CSEM</strong>) <strong>and</strong> are industrialized by SpectraTime. These two frequency st<strong>and</strong>ards operate in cell conditions <strong>and</strong> the environment might cause long term drifts. While the RAFSs are very compact (2.4 liters, 3.4 kg), the PHMs show the long-term stability by a factor of 5 better, reaching the relative frequency variations of 10-14 for a measurement interval τ of 104 s. However, PHMs are bulky (26 liters, 18 kg), which was not the only argument for the European Space Agency (ESA) to search for a possible alternative, overcoming the long term drift of PHMs as well. A good c<strong>and</strong>idate was an atomic-beam frequency st<strong>and</strong>ard. Magnetically-pumped cesium beam clocks with separated oscillatory fields are used nowadays to define a second in the SI metric system, as 9’192’631’770 periods of microwave oscillations at the resonance with ground-state hyperfine splitting in 133Cs atoms. An atomic beam clock shows no frequency drifts, however, the clock with magnetic deflection of atoms cannot be deployed at a long-term mission satellite. Figure 1: Optically-pumped Space Cesium Atomic Resonator. (The GNSS Galileo requires a clock that operates 12 years.) Since the two hyperfine ground states of 133Cs atoms have 16 Zeeman sublevels, a commercial magnetically-deflected clock will typically run out of cesium in about 3 years, utilizing only 1/16 part of Cs atoms from the beam <strong>and</strong> yet lacking the required frequency stability. The solution was found to optically pump cesium atoms. A laser-pumped atomic-beam resonator has better short-term stability <strong>and</strong> has a real potential to compete with the PHM, offering smaller frequency drift <strong>and</strong> a simpler design. Since 2004, ESA supports the development of ultra stable atomic beam clocks, which has been initiated at the former Neuchatel observatory <strong>and</strong> then continued at <strong>CSEM</strong>. This activity resulted in the Optically-pumped Space Cesium Atomic Resonator (OSCAR) demonstrator shown in Figure 1 <strong>and</strong> Figure 2. The project was successfully closed in the past year, reaching the goal of relative frequency stability in the range 1÷3x10-12 at 1s [1] . However the OSCAR demonstrator was quite far from a design compatible with the space applications, by consuming Cesium too fast. The next step towards space, the project on feasibility study of cesium clock technology for Galileo (ESA), was initiated in 2006, when Thales Electron Devices (TED) set up a French- Swiss consortium (<strong>CSEM</strong>, SYRTE <strong>and</strong> Oerlikon Space Zurich as partners) aiming at a breadboard of the flight-compatible atomic resonator with the relative frequency stability 1x10-12τ-1/2 <strong>and</strong> flicker noise floor 10-14 for a measurement interval 105 s. The objective was to develop an atomic resonator technology ensuring the clock operation for 12 years. In the past <strong>2008</strong> year, the goal of this project was achieved [ 2, 3] . Figure 2 shows the breadboard of Opticallypumped Space Cesium Clock (OSCC) for Galileo. In the next phase of cesium atomic beam clock development for space applications, which starts in 2009, the French-Swiss consortium will build a size-representative elegant breadboard of the clock (15 liters, 10 kg) based on previous development at <strong>CSEM</strong>. Figure 2: Optically-pumped Space Cesium Clock at <strong>CSEM</strong>. [1] Project web page http://telecom.esa.int/telecom/www/object/index.cfm?fobjectid=2 9392 [2] R. Ruffieux, et al., “Optically-pumped Space Cesium Clock for Galileo: Results of the Breadboard”, Proc. of the 7th Symposium on Frequency St<strong>and</strong>ards <strong>and</strong> Metrology <strong>2008</strong>, Pacific Grove, CA, USA, to be published. [3] P. Berthoud, et al., “Optically-pumped Space Cesium Clock for Galileo: First Results of the Breadboard”, IEEE International Frequency Control Symposium jointly with the 22st European Time <strong>and</strong> Frequency Forum, Toulouse (FR), April <strong>2008</strong> 99
100
- Page 1 and 2:
centre suisse d’électronique et
- Page 4 and 5:
CONTENTS PREFACE 5 RESEARCH ACTIVIT
- Page 6:
PREFACE Dear Reader, In this report
- Page 9 and 10:
TissueOptics - Portable Pulse Oxime
- Page 11 and 12:
PackTime - Zero-level Packaging of
- Page 13 and 14:
BioTool - an Integrated Parallel At
- Page 15 and 16:
SUMO - SUrface MOdified Vision Syst
- Page 17 and 18:
SixSense - Six Dimensional Micro Se
- Page 20 and 21:
MICROELECTRONICS Christian Enz The
- Page 22 and 23:
Hand Detection Using Boosted Classi
- Page 24 and 25:
A Low-power 32-bit Dual-MAC 120 µW
- Page 26 and 27:
Design of RF Passives in 65 nm CMOS
- Page 28 and 29:
Effect of Size on the Performance o
- Page 30:
Wireless Sensor Networks Built Usin
- Page 33 and 34:
Massively Parallel Optical Tomograp
- Page 35 and 36:
High-speed Imagers P. Buchschacher,
- Page 37 and 38:
Applications of X-ray Phase Contras
- Page 39 and 40:
Enhanced Visual Chemical Sensor Bas
- Page 41 and 42:
Integrated Organic Spectrometer on
- Page 44 and 45:
NANOTECHNOLOGY & LIFE SCIENCES Harr
- Page 46 and 47:
Polarization Imaging using Nanostru
- Page 48 and 49:
Plasmon Based All Optical Switch R.
- Page 50 and 51: Gold Nanorings from Block Copolymer
- Page 52 and 53: J-aggregates inside Mesoporous Meta
- Page 54 and 55: Batch Fabrication of Ultrathin Nano
- Page 56 and 57: A Liquid Delivery System for Single
- Page 58 and 59: On-chip Electrical Characterization
- Page 60 and 61: Surfaces that Regulate Cell Growth
- Page 62 and 63: Sensing Optical Fibres for Integrat
- Page 64 and 65: Miniaturization of an Integrated Op
- Page 66 and 67: NANOMEDICINE Peter Seitz The Europe
- Page 68 and 69: High-Efficiency X-ray Microscopy an
- Page 70 and 71: A Universal Protein Assembler H. Ze
- Page 72 and 73: A Microfluidic Chip for Cytotoxicol
- Page 74 and 75: The CSEM Electrical Impedance Tomog
- Page 76: DNA-fragment Binding Studies on the
- Page 79 and 80: Fall Detector in Wrist Device M. Be
- Page 81 and 82: Distributed Electronics for Wearabl
- Page 83 and 84: Using IEEE 802.15.4 for Athlete Con
- Page 85 and 86: Compressed Sensing: Multi-user Impu
- Page 87 and 88: Efficient Information Dissemination
- Page 89 and 90: A Remote Reconfiguration Mechanism
- Page 91 and 92: European Large Telescope M5 Field S
- Page 93 and 94: Integration and Tests of the Config
- Page 95 and 96: Reaction Sphere for Attitude Contro
- Page 97 and 98: Compact Cell Atomic Clocks and Semi
- Page 99: Guidance Navigation and Control Sys
- Page 103 and 104: Low Cost Micro Metrology Concept P.
- Page 105 and 106: Static Micromixer with Minimized De
- Page 107 and 108: A Noninvasive Sensor for Fluidic Pr
- Page 109 and 110: Integrated ESR Sensors R. Jose Jame
- Page 111 and 112: Laser Micromachining for Microfluid
- Page 113 and 114: Low-cost Packages for Ultrabright L
- Page 115 and 116: Small Volume Production S. Jeannere
- Page 117 and 118: Engineering of Thin Film Crystallin
- Page 119 and 120: New Technology Platforms Alex Domma
- Page 121 and 122: [18] S. Jeanneret, A. Dommann, N. F
- Page 123 and 124: Proceedings [1] C. Arm, S. Gyger, J
- Page 125 and 126: [37] A. Ridolfi, O. Chételat, J. K
- Page 127 and 128: A. Dommann "Reliability and test fo
- Page 129 and 130: A. Meister, J. Przybylska, P. Niede
- Page 131 and 132: P. Seitz "Advanced Scientific Imagi
- Page 133 and 134: 9495.1 LAF CFMCW - Coherent Frequen
- Page 135 and 136: FP6 - NMP NANOSECURE Advanced nanot
- Page 137 and 138: Industrial Property Creativity In 2
- Page 139 and 140: University Institute Professor Fiel
- Page 141 and 142: C. Piguet Microélectronique pour S
- Page 143 and 144: PhD Funded by CSEM Name Professor /
- Page 145 and 146: H. Heinzelmann Evaluator, Austrian
- Page 147: Headquarters CSEM Centre Suisse d