Dicke Candidate Seminar | Ariel Cukierman| Multiscale multichroic focal planes for measurements of the cosmic microwave background | Jadwin A09

Mon, Dec 11, 2017, 2:30 pm


Lithographed superconducting detectors have found many applications in millimeter and submillimeter astronomy including observations of the cosmic microwave background (CMB). A major goal of modern cosmology is to make precise measurements of the polarized fluctuations in the CMB with science goals such as a measurement of the sum of neutrino masses and a detection of primordial B-modes, which would be considered direct evidence for an inflationary epoch in the early universe. The signals of interest are at the level of 10-100 nK on a 2.7-K background, which motivates the development of increasingly sensitive instruments. The Berkeley CMB group has been developing broadband (multichroic) pixels consisting of planar superconducting sinuous antennas coupled to extended hemispherical lenses and transition-edge-sensor (TES) bolometers. A recent advance is in the demonstration of a multiscale architecture, i.e., one in which the effective pixel size changes as a function of frequency. This property keeps the beam width approximately constant across all frequencies, which allows the sensitivity of the experiment to be near-optimal in every frequency band. The design is based on a hierarchy of phase-arrayed sinuous antennas. In this talk, I will describe the detector-development effort of the Berkeley CMB group and its connections to current and upcoming CMB experiments.


Jadwin A09