# Lifetime Testing UV LEDs for Use in the LISA Charge Management System

## TL;DR

This study evaluates the long-term reliability of UV LEDs for space-based charge management in LISA, demonstrating that some LEDs can last over 25 years under realistic operational conditions.

## Contribution

It provides the first comprehensive lifetime testing data for UV LEDs in space mission conditions, establishing their suitability for LISA's charge management system.

## Key findings

- Two UV LED types last over 25 years in simulated space conditions.
- UV LEDs outperform traditional mercury lamps in longevity and performance.
- The tests validate UV LEDs as reliable, long-term solutions for space charge management.

## Abstract

As a future charge management light source, UV light-emitting diodes (UV LEDs) offer far superior performance in a range of metrics compared to the mercury lamps used in the past. As part of a qualification program a number of short wavelength UV LEDs have been subjected to a series of lifetime tests for potential use on the Laser Interferometer Space Antenna (LISA) mission. These tests were performed at realistic output levels for both fast and continuous discharging in either a DC or pulsed mode of operation and included a DC fast discharge test spanning 50 days, a temperature dependent pulsed fast discharge test spanning 21 days and a pulsed continuous discharge test spanning 507 days. Two types of UV LED have demonstrated lifetimes equivalent to over 25 years of realistic mission usage and provide a baseline and backup solution for LISA.