A Plasma Diagnostic Package (PDP) is a set of scientific instruments designed to measure key properties of plasma without disturbing it. In this study, the PDP integrates an active Thomson scattering system and an Optical Emission Spectroscopy (OES) system.

The objectives are to demonstrate the application of the PDP to the Wisconsin Hydrogen Alpha Mapper (WHAM) experiment and to measure plasma parameters, including electron temperature, density, and ion velocity. One of the main goals is to provide insights into plasma behavior and to advance experimental plasma studies.

The system utilises components coated with super black materials for stray light suppression. Black coated surfaces with Acktar’s ultra black properties were used to absorb unnecessary reflections and enhance SNR. These black coatings were crucial in achieving reliable results in a high-flux environment.

The PDP functions as a compact unit that can be rapidly deployed and integrated into existing plasma experiments. The OES system uses a spectrometer to measure impurity lines and plasma rotation, while the TS system uses a pulsed laser to illuminate the plasma and extract localized electron temperature and density profiles.

The PDP successfully measured plasma rotation profiles and electron temperature in commissioning plasmas on WHAM. Additionally, it resolved line emissions from various ions to determine ion temperatures and impurity dynamics through passive OES. The TS system enabled the first measurements of electron temperature in commissioning plasmas on WHAM.

The contribution of black-coated surfaces, especially the darkest black coatings used in various applications, is vital to system performance. These helped maintain thermal and optical stability within the setup and prevented background IR radiation from disrupting the signal while highlighting the significance of IR coating materials in precision optical instruments.

Fujii, D. Endrizzi, J. K. Anderson, C. B. Forest, J. Pizzo, T. Qian, M. Yu, and T. M. Biewer, “Application of the Portable Diagnostic Package to the Wisconsin HTS Axisymmetric Mirror (WHAM),” arXiv preprint, arXiv:2505.11473, May 16, 2025.