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Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of(More)
We present a measurement of the cosmic microwave background (CMB) gravitational lensing potential using data from the first two seasons of observations with SPTpol, the polarization-sensitive receiver currently installed on the South Pole Telescope (SPT). The observations used in this work cover 100 deg 2 of sky with arcminute resolution at 150 GHz. Using a(More)
We have constructed an achromatic half wave plate (AHWP) suitable for the millimeter wavelength band. The AHWP was made from a stack of three sapphire a-cut birefringent plates with the optical axes of the middle plate rotated by 50.5 degrees with respect to the aligned axes of the other plates. The measured modulation efficiency of the AHWP at 110 GHz was(More)
1 This white paper was assembled by Lyman Page with input from many of the co-signers. It is part of the efforts of NASA'a Primordial Polarization Program Definition Team (PPPDT), Shaul Hanany chair, and of a NASA award to Steve Meyer and colleagues entitled " A study for a CMB Probe of Inflation " (07-ASMCS07-0012). Executive summary How did the universe(More)
We present measurements of the electrical and thermal properties of new arrays of bolometeric detectors that were fabricated as part of a program to develop bolometers optimized for the low photon background of the EBEX balloon-borne experiment. An array consists of 140 spider-web transition edge sensor bolometers microfabricated on a 4 " diameter silicon(More)
The increasing scale of cryogenic detector arrays for submillimeter and millimeter wavelength astrophysics has led to the need for large aperture, high index of refraction, low loss, cryogenic refracting optics. Silicon with n=3.4, low loss, and high thermal conductivity is a nearly optimal material for these purposes but requires an antireflection (AR)(More)
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