ABSTRACT Spider, the Keck Array, and BICEP2 are projects to study the polarization of the cosmic ... more ABSTRACT Spider, the Keck Array, and BICEP2 are projects to study the polarization of the cosmic microwave background (CMB). All three use large format arrays of antenna-coupled, membrane-isolated, transition edge sensors (TES’s). Although similar, each project requires its own set of device parameters, such as thermal conductance, time constants, and normal state resistances. We have perfected a fabrication process that achieves two primary objectives: (1) high device yields of 95% or greater, and (2) very low spreads in devices parameters. Currently our arrays are taking science data at the South Pole in both the BICEP2 and Keck array telescopes. The focal planes for Spider, a high altitude balloon mission, are on schedule for a 2012 deployment. An overview of fabrication and development is given as well as a snapshot of scientific data.
ABSTRACT We have deployed arrays of antenna-coupled TES bolometers for cosmic microwave backgroun... more ABSTRACT We have deployed arrays of antenna-coupled TES bolometers for cosmic microwave background (CMB) polarimetry in the BICEP2 and Keck array experiments and will deploy similar detectors in SPIDER and Polar-1. Each pixel receives optical power centered at 146 GHz with a 20% bandwidth (−10 dB edges) through an integrated dual-polarized phased-array antenna. In past deployments, these detectors have shown offsets in the two polarizations’ beam centroids (differential ‘steering’), but we have redesigned the feed networks by strategically spacing lines and adding intentional phase delays to suppress this unwanted effect. We expect that the focal planes in this season’s deployment of Keck and in SPIDER will have detectors with less than 5′ steering, which is 0.5% of the 14.2° nominal antenna’s FWHM (i.e. without lenses). We have also redesigned the antenna-array’s illumination pattern to suppress side-lobe response in anticipation of the Polar-1 experiment, reducing spillover by a factor of 2.5.
We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and K... more We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150 GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes...
The ACBAR photometer on the Viper telescope at the South Pole has been used to map the Cosmic Mic... more The ACBAR photometer on the Viper telescope at the South Pole has been used to map the Cosmic Microwave Background with 5 arcminute resolution. Several fields of size 2 x 3 degrees have been mapped at 150 GHz with a per-beam noise level about 25 microkelvin. The same fields have also been mapped at 220, 280 and 350 GHz, but
The SPT‐SZ is, currently, the most powerful instrument for detecting galaxy clusters through the ... more The SPT‐SZ is, currently, the most powerful instrument for detecting galaxy clusters through the Sunyaev‐Zel'dovich (SZ) effect. The SPT‐SZ focal plane consists of over 700 background limited TES spiderweb bolometers observing in three different pass bands (90 GHz, 150 GHz, ...
SPTpol will consist of an 850 element polarization sensitive bolometric camera deployed to the So... more SPTpol will consist of an 850 element polarization sensitive bolometric camera deployed to the South Pole Telescope in late 2011. This camera is optimized for measurement of the polarization of the cosmic microwave background with arcminute resolution. These measurements will ...
ABSTRACT Spider, the Keck Array, and BICEP2 are projects to study the polarization of the cosmic ... more ABSTRACT Spider, the Keck Array, and BICEP2 are projects to study the polarization of the cosmic microwave background (CMB). All three use large format arrays of antenna-coupled, membrane-isolated, transition edge sensors (TES’s). Although similar, each project requires its own set of device parameters, such as thermal conductance, time constants, and normal state resistances. We have perfected a fabrication process that achieves two primary objectives: (1) high device yields of 95% or greater, and (2) very low spreads in devices parameters. Currently our arrays are taking science data at the South Pole in both the BICEP2 and Keck array telescopes. The focal planes for Spider, a high altitude balloon mission, are on schedule for a 2012 deployment. An overview of fabrication and development is given as well as a snapshot of scientific data.
ABSTRACT We have deployed arrays of antenna-coupled TES bolometers for cosmic microwave backgroun... more ABSTRACT We have deployed arrays of antenna-coupled TES bolometers for cosmic microwave background (CMB) polarimetry in the BICEP2 and Keck array experiments and will deploy similar detectors in SPIDER and Polar-1. Each pixel receives optical power centered at 146 GHz with a 20% bandwidth (−10 dB edges) through an integrated dual-polarized phased-array antenna. In past deployments, these detectors have shown offsets in the two polarizations’ beam centroids (differential ‘steering’), but we have redesigned the feed networks by strategically spacing lines and adding intentional phase delays to suppress this unwanted effect. We expect that the focal planes in this season’s deployment of Keck and in SPIDER will have detectors with less than 5′ steering, which is 0.5% of the 14.2° nominal antenna’s FWHM (i.e. without lenses). We have also redesigned the antenna-array’s illumination pattern to suppress side-lobe response in anticipation of the Polar-1 experiment, reducing spillover by a factor of 2.5.
We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and K... more We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150 GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes...
The ACBAR photometer on the Viper telescope at the South Pole has been used to map the Cosmic Mic... more The ACBAR photometer on the Viper telescope at the South Pole has been used to map the Cosmic Microwave Background with 5 arcminute resolution. Several fields of size 2 x 3 degrees have been mapped at 150 GHz with a per-beam noise level about 25 microkelvin. The same fields have also been mapped at 220, 280 and 350 GHz, but
The SPT‐SZ is, currently, the most powerful instrument for detecting galaxy clusters through the ... more The SPT‐SZ is, currently, the most powerful instrument for detecting galaxy clusters through the Sunyaev‐Zel'dovich (SZ) effect. The SPT‐SZ focal plane consists of over 700 background limited TES spiderweb bolometers observing in three different pass bands (90 GHz, 150 GHz, ...
SPTpol will consist of an 850 element polarization sensitive bolometric camera deployed to the So... more SPTpol will consist of an 850 element polarization sensitive bolometric camera deployed to the South Pole Telescope in late 2011. This camera is optimized for measurement of the polarization of the cosmic microwave background with arcminute resolution. These measurements will ...
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Papers by M. Lueker