Test mass charge management in the detection of gravitational waves in space based on UV micro-LED

TL;DR

This study explores the use of UV micro-LEDs for charge management in space-based gravitational wave detection, demonstrating their effectiveness, space qualification, and potential for future space deployment.

Contribution

It introduces UV micro-LEDs as a compact, efficient alternative for charge management in space gravitational wave detectors, with experimental validation and space qualification progress.

Findings

Micro-LEDs demonstrated effective charge management with varied discharge rates.

Performance characteristics showed less than 5% variation, indicating stability.

Micro-LED technology reached TRL-5, nearing space readiness.

Abstract

As an alternative to the ultraviolet light emitting diode(UV LED), the feasibility of utilizing UV micro-LED in the charge management in the detection of gravitational waves in space is experimentally studied. Compared with UV LED, micro-LED is more compact in size, has better current spreading, faster response time and longer operating life. Performance characteristics of micro-LEDs were measured, with peak wavelength of 254 nm, 262 nm, 274 nm, and 282 nm for each respective micro-LED, and the photoelectric effect was demonstrated. The effectiveness of micro-LED based charge management experiments were demonstrated using above micro-LEDs mounted on a cubical test mass, and different discharge rates were achieved by varying the drive current and duty cycle using pulse width modulation(PWM). Laboratory data was also shown to demonstrate the space qualification of the micro-LED device, the key electrical and optical characteristics of the micro-LEDs showed less than 5% variation. The results of the qualification bring the micro-LED device Technology Readiness Level(TRL) to TRL-5. TRL-6 will be reached provided additional radiation and thermal tests are conducted and in a position ready to be flown and further tested in space.