The LSPE-Strip beams

TL;DR

This paper details the design, simulation, and characterization of the LSPE/Strip optical system, a microwave polarimeter array for sky observation, focusing on understanding systematic effects for precise measurements.

Contribution

It provides electromagnetic simulations of the LSPE/Strip optical system, analyzing key parameters like resolution, sidelobes, and polarization purity to inform future data analysis.

Findings

Electromagnetic simulations characterized the optical system's resolution and sidelobes.

Results will guide systematic effect mitigation in data analysis.

Essential input for further optical optimization and scientific interpretation.

Abstract

In this paper we describe the design and characterization of the optical system of LSPE/Strip, a coherent polarimeter array that will observe the microwave sky from the Teide Observatory in Tenerife in two frequency bands centred at 43 and 95 GHz through a dual-reflector crossed-Dragone telescope of 1.5 m aperture. In general, optical systems composed by a telescopefeed array assembly have non-idealities that might limit their ability to perform high-precision measurements. It is thus necessary to understand, characterize and properly control these systematic effects. For this reason, we performed electromagnetic simulations to characterize angular resolution, sidelobes, main beam symmetry, polarization purity and feedhorns orientation. The results presented in this paper will be an essential input for further optical studies and for the LSPE/Strip data analysis. Ultimately, they will be used to assess the impact of optical systematic effects on the scientific results.