Building custom magnetic field coils, pulsed power systems, and scientific instrumentation since 2005
Refractive-Index Measurements
The refractive index of a plasma is a robust indicator of the electron density. Interferometers are commonly used to take a chord-averaged measurement of the refractive index, thereby measuring the density along the beam line. An interferometer is favored for its non-perturbing measurement, at the expense of point resolution. Interferometers are often deployed in sets, sampling several chords to build up profile information for the target plasma. Woodruff Scientific provides interferometers in microwave, infrared (CO2), and visible (HeNe) wavelengths to meet your specifications for sensitivity range and vibration tolerance. Density profile information can also be recovered through additional refractive-index diagnostics such as reflectometry (in which the beam is reflected by a surface at the cutoff density) and refractometry (in which the deflection or spread of the transmitted beam is used to infer the density profile). Finally, one can also use the difference in refractive index between left and right circularly polarized waves in a polarimeter to achieve a chord-averaged measurement of the magnetic field component parallel to the beam. An excellent reference for refractive index diagnostics is Hutchinson's Principles of Plasma Diagnostics 2nd Edition.
HeNe Interferometer
Microwave Interferometer
Fiber-Coupled Interferometer
Fiber-coupled interferometers are very flexible and robust systems, often allowing for lines of sight to be quickly changed without the need for optical realignment.
Fiber-Coupled, Two-Color Interferometer
This two-color system provides vibration compensation in addition to the flexibility and robustness of fiber-coupled systems.
CO2 Interferometer
CO2 Interferometer References
Polarimeter
Polarimeter References
Optical Mount Components for 3D Printing
Over time, we plan to develop a whole range of mechanical components for use in our diagnostics, passing on cost savings to customers in the diagnostics. It is also possible that we can design the entire optical system as a single monolithic structure to be printed with alignment built-in. Check back in the coming months as we add more information here, and to our thingiverse pages.
Download files ready for 3D-printing: Optical Mount, Optical Mount Adjust
Download files ready for 3D-printing: Beam splitter Mount (for 40mm cube beam splitter)
Download files ready for 3D-printing: Laser Mount (uses 1/4 20 nuts and screws)