Dark Energy Spectroscopic Instrument (DESI) Fiber Positioner Thermal and Wind Disturbance Test

TL;DR

This paper details thermal and wind disturbance testing of DESI fiber positioners, ensuring their reliable operation under extreme conditions to support the instrument's goal of mapping the universe's expansion.

Contribution

It presents the testing procedures and results that enhanced the robustness of DESI fiber positioners against temperature variations and wind disturbances.

Findings

Thermal tests identified temperature limits for optimal performance.

Wind disturbance tests informed ventilation system design.

Test results improved fiber positioner robustness.

Abstract

The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 sq deg will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. To achieve this goal, it is crucial to guarantee that fiber positioners work properly under the extremes of potential operating conditions, including the full range of temperatures, high speed wind disturbance etc. Thermal testing provides valuable insight into the functionality of the fiber positioners that can be used to help mitigate poor performance at extreme temperatures and wind disturbance test provide guidance to design of ventilation system. Here, we describe the thermal and wind disturbance tests for DESI fiber positioners and how the test results helped improve the robustness of the positioners.