PROTOCALC: an artificial calibrator source for CMB telescopes

TL;DR

PROTOCALC is a newly developed polarized calibrator source for CMB telescopes at 90GHz, enabling precise instrument characterization essential for accurate polarization measurements in cosmology.

Contribution

It introduces PROTOCALC, a novel artificial polarized calibrator with high polarization angle accuracy, specifically designed for CMB experiments at 90GHz.

Findings

First flight in May 2022 demonstrating functionality.

Achieved polarization direction accuracy better than 0.1 degrees.

Shows promising results for future CMB calibration applications.

Abstract

Cosmic Microwave Background experiments need to measure polarization properties of the incoming radiation very accurately to achieve their scientific goals. As a result of that, it is necessary to properly characterize these instruments. However, there are not natural sources that can be used for this purpose. For this reason, we developed the PROTOtype CALibrator for Cosmology, PROTOCALC, which is a calibrator source designed for the 90GHz band of these telescopes. This source is purely polarized and the direction of the polarization vector is known with an accuracy better than 0.1deg. This source flew for the first time in May 2022 showing promising result