Phys.org October 26, 2021 Compact cold-atom sensors depend on vacuum technology. One of the major limitations to miniaturizing these sensors is the active pumps that are required to sustain the low pressure needed for laser cooling. Although passively pumped chambers have been proposed as a solution to this problem, technical challenges have prevented successful operation at the levels needed for cold-atom experiments. A team of researchers in the US (Sandia National Laboratory, University of Oklahoma) has demonstrated a vacuum package that is independent of ion pumps for more than a week. It can sustain a cloud of cold atoms in […]
Category Archives: GPS
Physics experiment in Earth’s atmosphere could help improve GPS performance
Phys.org October 27, 2021 Plasma in the ionosphere plays a significant role in reflecting and modifying radio waves used for communication and radio navigation systems such as GPS, but the accuracy of these can be affected by ‘space weather’ events such as solar storms. The space weather events dynamically increase the total number of ionospheric electrons; GPS systems cannot correctly model this dynamic enhancement and errors occur in position calculations. An international team of researchers (UK, Norway, Portugal) conducted a controlled radar wave experiment by injecting radio waves into the ionosphere, at slightly different frequencies. By annlyzing the returned signals […]