Keywords

EUV, extreme ultraviolet, optics, aluminum, reflectance

Abstract

The best material for constructing a mirror for a broad-bandwidth telescope that is also capable of reflecting EUV light is pure aluminum. In order to test how the reflectance of aluminum in the EUV range changes as it oxidizes, a system has been constructed that allows a thin aluminum mirror to be constructed inside of a vacuum, where its reflectance can then be tested immediately. Because the experiment must take place in a vacuum, it must also be controlled remotely through a computer program, which manages the mirror fabrication process as well as the collection and analysis of reflectance data. This data analysis process accounts for other factors that influence the measured intensity of the reflected light aside from the surface of the mirror and the angle of incidence, including the position of the detector, random noise, and the time dependence of the plasma source. This ensures that the actual reflectance of the mirror at a given angle of incidence is always clearly distinguishable in the data. The fabrication controls are now at a stage where they can be used to create a mirror inside the chamber of the reflectometer. A separate part of the program is currently in use to scan the detector across the beam and perform several calculations using the resulting data. Once the most consistent method of analysis is determined, this method will be implemented as part of the main program, which will then be ready for testing with the experimental equipment.

Description

This paper was completed during the 2017 Research Experiences for Undergraduates in Physics (REU) program. More information about this program can be found here.