Novel calibration system with sparse wires for CMB polarization receivers

Conference · Fri Jul 01 04:00:00 EDT 2011

OSTI ID:1022776

Tajima, O; Nguyen, H; Bischoff, C; Brizius, A; Buder, I

B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature ({approx}10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL
• Sponsoring Organization: DOE Office of Science
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1022776
• Report Number(s): FERMILAB-CONF-11-327-AE-E
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMBIENT TEMPERATURE
Astrophysics
Instrumentation
BOLOMETERS
CALIBRATION
CHILE
DESERTS
INFLATIONARY UNIVERSE
PERFORMANCE
POLARIZATION
RADIATIONS
REFLECTION
RELICT RADIATION
SENSITIVITY
SKY