McPherson Spectrometers for Green, Clean Fusion Power

McPherson, Inc. receives multiple Spectrometer Contracts from U.S. Department of Energy Major Fusion Projects: Princeton Plasma Physics Lab and General Atomics.

McPherson, Inc. received additional contracts from major US fusion research facilities during the fourth quarter 2008. The contracts call for McPherson, Inc. Model 207 spectrometers for use at the NSTX experiment at Princeton Plasma Physics Laboratory (PPPL) in New Jersey, and additional unit(s) slated for the DIII-D experiment at General Atomics in San Diego, California. Some units have already been delivered with more scheduled for shipment during the first quarter of 2009.

The McPherson Spectrometer Model 207 has 0.67 meter focal length and f/4.7 aperture ratio. For given applications, the instrument can accommodate various gratings with different groove densities and blaze wavelengths. Used with a 1200 groove per millimeter grating and a wavelength setting at 529 nm, the reciprocal linear dispersion at the exit focal plane is 1.2 nanometers per millimeter. It means that 1.2 nanometers of spectral energy are dispersed onto 1 mm of focal plane. With an aperture or exit slit set to 10 micron width, one hundredth or 0.012 nanometers equaling 0.12 angstroms are resolved.

Similar opto-mechanical McPherson spectrometers are used for Visible-light diagnostic applications. At research facilities all around the world, McPherson instruments disperse emitted light to monitor the charge exchange recombination region of the magnetically confined plasma in experimental fusion reactors. Spectral light from high temperature plasmas helps scientists to discern the composition and temperature of occurring reactions. The principal investigators work with McPherson to equip spectrometers with special detector systems and input fiber-optic arrays best suited for their respective investigations and facilities.

Fusion power may one day provide abundant energy. It will not produce long-lived nuclear waste or air pollution. Similar to the process occurring in the Sun and other stars, the high temperature fusion plasmas will be harnessed to yield energy convertible into electricity. Fusion is a technically challenging task, involving large, elaborate experiments, confined high temperature plasmas, and neat spectral and other analysis.