Investigations on assembly and coverage for modular focal planes of multiplexed telescopes

TL;DR

This paper investigates various assembly methods for modular focal planes in multiplexed telescopes, optimizing coverage and alignment for future large-scale spectroscopic surveys.

Contribution

It introduces and compares framed, semi-frameless, and frameless module assembly techniques, including automated focal plate generation for adaptable telescope instrumentation.

Findings

Framed and semi-frameless assemblies provide precise focus and tilt control.

Frameless assembly offers a flexible connection method without a focal plate.

All methods aim to optimize coverage and assembly efficiency.

Abstract

Multiplexed surveys have the ambition to grow larger for the next generation of focal plane instruments. Future projects such as Spec-S5, MUST, and WST have an ever-growing need for multi-object spectroscopy (13,000 - 20,000 simultaneous objects) which demands further investigations of novel focal plane instrumentation. In this paper, we present a rigorous study of focal plane coverage optimization and assembly of triangular modules of alpha-beta fiber positioners with a 6.2 mm pitch. The main focus here is to examine different module arrangements namely, framed, semi-frameless, and fullyframeless assemblies. Framed and semi-frameless describe here the usage of a manufactured focal plate to hold the modules together and provide the correct focus and tilt to the fibers. Work on automatically generating such focal plates for project adaptability and ease of manufacturing will also be presented. On the other hand, the frameless approach proposes a connection method freed from the need of a focal plate. The following paper will also present their capabilities to meet the requirements for focal plane assembly such as focus, tilt and coverage.