Space atomic clock used to detect gravitational waves

American physicists have already released a proposal for a gravitational wave detector made from two space atomic clocks. The plan involves placing two atomic clocks in different places around the sun and using them to measure small changes in the frequency of the laser beam from clock to clock. The designers claim that the detector will be used to complement the LISA space gravitational wave detector and is expected to launch in 2034. Gravitational wave is a kind of corrugation in space time fabric, which is produced when the celestial body accelerates. In February this year, LIGO jointly announced the first direct history of gravitational waves being detected. Using a pair of kilometer-sized interferometers located in the United States under two black hole mergers, The exploration carried out. In the past week, the Laser Interference Gravitational Wave Observatory detected a second gravitational wave on the basis of another different black hole merger. Now, Shimon Kolkowitz and Jun Ye of the Colorado Collaboration in Experimental Astrophysics worked with Mikhail Lukin and colleagues at Harvard University to propose a proposal to detect gravitational waves using two space atomic clocks. Each device will be equipped with an optical lattice atomic clock, which is a very accurate timer, the use of atomic transition frequency measurement time. The atoms are imprisoned in a one-dimensional optical lattice, a standing wave generated by a mirror that reflects the laser light. This is a very effective way for atoms to shield noise from the outside that slows clock performance. Lock the laser Each satellite will also contain an ultra-stable laser source that will be launched from one satellite to another and vice versa. The optical system on the satellite locks the two lasers onto a single frequency, essentially creating a single laser at a single frequency. When a gravitational wave travels through the solar system, it causes periodic relative motion between the satellites, bringing them closer together and then separating them again, then approaching again. This motion will result in a Doppler shift of the laser because as the satellites move closer together the frequency of laser propagation between the spacecraft increases slightly and the laser frequency drops slightly again when the satellite moves apart . In the research proposal, the activity will be probed by using an atomic clock in a satellite called "A" to measure the frequency of the laser light it outputs. The atomic clock of satellite B will measure the frequency of the incident laser light from A because the atomic clocks are the same and any difference in the frequencies measured at A and B can only be caused by the gravitational waves assuming here that the relative motion of all other satellites has been Reduce to a suitable level. "All we want to detect is the small, periodic changes in laser frequency," Kolkowitz. Narrowband detection Unlike Lisa detectors, this device will be able to detect gravitational waves at a relatively wide frequency (0.03 100 MHz) and the proposed atomic clock detector will be narrow-band in nature with the best working signal The frequency is about 3 milli-Hz. And this does not offer any real benefit over Lisa's detectors, which is its maximum sensitivity in the millihertz range. Kolkowitz said the narrow-band "window" of the detector can be moved from 3 mHz to Up to 10 Hz without loss of strength. This adjustment can be done by adjusting the atomic clock to measure the laser frequency. This may prove to be very useful, as most of the tunable ranges go beyond the capabilities of the laser interferometer Gravity Observatory and Lisa. This means that a black hole combined with a gravitational wave can be detected a few years earlier by a Lisa probe when the gravitational waves radiated by the black hole are at a frequency of millihertz. As the black hole merges, the frequency of the gravitational waves will increase and exceed the working frequency of the Lisa detector. "With our detector's tunable narrowband mode, you can continue to detect and track gravitational waves until we can exploit the visible range that the Observatory can detect with the laser interferometer," Kolkowitz said. Spacecraft clock Kolkowitz and his colleagues think that their design can be integrated into the Lisa spacecraft. "We hope our advice will provide a reference path for thinking about integrating the optical lattice atomic clock into the spacecraft," he said. Kolkowitz also pointed out that such a clock network in space will allow physicists to complete new testing and exploration of the unknown physical nature and basic laws. Tim Sumner of the Imperial College London, who is working on the Lissajous detector, believes that it is highly unlikely that the European Space Agency will develop a completely new technology and implementation plan at this stage. Instead, he believes that an atomic clock-based graviton wave detector can be thought of as a future mission.