Design and performance characterization of a new LISA-like (laser interferometer space antenna-like) gravitational reference sensor and torsion pendulum testbed.

In this paper, we present the design and performance of the upgraded University of Florida torsion pendulum facility for testing inertial sensor technology related to space-based gravitational wave observatories and geodesy missions. In particular, much work has been conducted on inertial sensor technology related to the Laser Interferometer Space Antenna (LISA) space gravitational wave observatory mission. A significant upgrade to the facility was the incorporation of a newly designed and fabricated LISA-like gravitational reference sensor (GRS) based on the LISA Pathfinder GRS. Its LISA-like geometry has allowed us to make noise measurements that are more representative of those in LISA and has allowed for the characterization of the mechanisms of noise induced on a LISA GRS and their underlying physics. Noise performance results and experiments exploring the effect of temperature gradients across the sensor will also be discussed. The LISA-like sensor also includes unique UV light injection geometries for UV LED based charge management. Pulsed and DC charge management experiments have been conducted using the University of Florida charge management group's technology readiness level 4 charge management device. These experiments have allowed for the testing of charge management system hardware and techniques as well as characterizations of the dynamics of GRS test mass charging. The work presented here demonstrates the upgraded torsion pendulum's ability to act as an effective testbed for GRS technology.

High volume UV LED performance testing.

There is increasing interest in deep UV Light-Emitting Diodes (LEDs) for applications in water purification, virus inactivation, sterilization, bioagent detection, and UV curing, as well as charge management control in the Laser Interferometer Space Antenna (LISA), which will be the first gravitational wave detector in space. To fully understand the current state of commercial UV LEDs and assess their performance for use on LISA, large numbers of UV LEDs need to be tested across a range of temperatures while operating in air or in a vacuum. We describe a new hardware system designed to accommodate a high volume of UV LED performance tests and present the performance testing results from over 200 UV LEDs with wavelengths in the 250 nm range.