New detectors will hunt for primordial gravitational waves in Chile and Antarctica

IEEE Spectrum : In 2014, before the Laser Interferometer Gravitational-Wave Observatory detected its first gravitational waves, the BICEP2 team claimed to find evidence of primordial gravitational waves embedded in the universe’s oldest light. Those results did not hold up. Now scientists are building several bigger and better superconducting receivers to detect multiple frequencies of that ancient light (the cosmic microwave background, or CMB) and hopefully isolate a gravitational-wave signal. In Chile’s Atacama Desert, two new telescopes will join the Huan Tran Telescope as part of the Polarization of Background Radiation experiment. The new telescopes will house a series of “sinuous” antenna detector arrays, each consisting of four zigzagging niobium arms covered with silicon lenses. Because of their repeating structure, the arrays will be able to pick up a wider range of CMB frequencies, depending on the orientation of the arms. A similar design will be used to upgrade the sensor array on the South Pole Telescope. Work to install the new arrays is scheduled to begin later this year at both locations.