The Multiple Color Video Pyrometer (MCVP) was developed
to measure the electrode temperatures of the Lithium
Lorentz Force Accelerator
(LiLFA). Knowledge of the electrode temperature can be used to help
determine the efficiency of the anode and cathode, the lifetime of the
thruster, and how the arc attaches to the cathode. The two primary
reasons for developing th MCVP were to validate the theory of arc attachment
within the cathode and to determine the evaporation rate (thus the lifetime)
of the cathode.
Measuring the temperature of the electrodes by direct-contact is
an extremely difficult task for many reasons:
- Temperatures exceed that of most direct-contact diagnostics (2500 K)
.
- Electromagnetic noise generated by the thruster arc interferes with
measurement signals.
- A detailed temperature profile requires many probes to be placed in
the harsh environment.
- The probe must be electrically insulated from the electrodes and the
plasma.
Pyrometry is immune to the problems that plague direct-contact measurement
because the thermal radiation from the hot surface is measured at a safe
distance from the thruster.
The MCVP consists of two components, the Thermal Imager on the right developed by Optical Insights, LLC
and the video camera, a Sony XCD-SX900 digital camera.
Relevant Publications
Relevant Links
Contact
lcassady@princeton.edu
