This image was produced as part of the calibration of a spectrometer for the Thomson scattering system on the Lithium Tokamak Experiment at the Princeton Plasma Physics Laboratory. This diagnostic is used to measure electron temperatures and densities in plasma experiments, including experimental fusion energy devices. Light from a calibrated source passes through a diffraction grating where it is separated by wavelength and is then sent to a CCD, a device used to capture images. The collected data is displayed using IDL, a software analysis tool. Colors represent the intensity of light.