CAPMAP (the Cosmic Anisotropy Polarization MAPper) consisted of sixteen heterodyne correlation polarimeters, twelve operating at 90 GHz and four operating at 40 GHz. These detectors were integrated on the Crawford Hill 7-meter antenna located in Holmdel, New Jersey, just a few hundred meters from the site where the CMB was first discovered!
CAPMAP operated for three winter seasons, starting in December 2002 and completing at the end of April 2005. Results from the first and third observing seasons have been published in Barkats et al. (2005) and Bischoff et al. (2008), respectively. The third-year data yield a detection of the CMB E-mode polarization over a range of angular scales from 400 < ℓ < 2000, with a total detection significance of 11σ, as well as upper limits on the level of B-mode polarization.
Novel aspects of CAPMAP include its fine angular resolution (since improved upon by QUaD, ACTpol, SPTpol, and POLARBEAR) and the fact that it was able to detect the faint CMB polarization with sensitivity comparable to other contemporary instruments, despite observing from a site with inferior atmospheric conditions.
- Bischoff et al. (2008), New Measurements of the Fine-Scale CMB Polarization Power Spectra from CAPMAP at Both 40 and 90 GHz, ApJ, 684, 2, 771 [ADS, arXiv:0802.0888]
- Barkats et al. (2005), First Measurements of the Polarization of the Cosmic Microwave Background Radiation at Small Angular Scales from CAPMAP, ApJ, 619, 2, L127 [ADS, arXiv:astro-ph/0409380]
- Barkats et al. (2005), Cosmic Microwave Background Polarimetry Using Correlation Receivers with the PIQUE and CAPMAP Experiments, ApJS, 159, 1, 1 [ADS, arXiv:astro-ph/0503329]