Thomson scattering
The Thomson scattering laser enters the chamber at section H-I (phi ~ 180 degrees), aimed toward section A-B (phi ~ 22 degrees). There are 17? core viewing chords looking down through a 6" port on top of the vessel in the H-I shell gap. There are 5? edge viewing chords
This document explains the access procedures for the Thomson laser capacitor banks
Jacobson, C. M. (2014). Electron transport in plasmas with lithium-coated plasma-facing components. Princeton University. Princeton University. Retrieved from [1]
Boyle, D. P. (2016, September). Measurements of impurity concentrations and transport in the Lithium Tokamak Experiment. Princeton University. Princeton University. Retrieved from [2]
Strickler, T., Majeski, R., Kaita, R., & LeBlanc, B. P. (2008). The Thomson scattering system on the lithium tokamak experiment. Review of Scientific Instruments, 79(10), 10E738. [3]
Acquisition
Holospec spectrometer and intensified (ICCD) camera measured up to 11 channels in LTX. New ICCD camera will measure 10-11 channels in LTX-β, perhaps ~17 if spectrometer optics improved. Possible new spectrometer would allow simultaneous use of old and new cameras. 5 polychromators will measure at least one channel each, 2-3 if we add delay lines.
Polychromator signals are digitized with CAEN digitizers located in racks against the east test cell wall next to the laser enclosure.
The system is presently triggered by the Jorway timing unit in the main CAMAC crate via a fiber optic link to the test cell. The initial trigger fires the flashlamps and the laser Q-switch fires 0.85 msec later.
??????? channels. Cables run from where to where?
The Thomson scattering power meter is digitized into Helios input 49.
The ICCD camera is controlled using WinSpec and a VisualBasic interface to automate the shot cycle and write raw data to the tree.
IDL routines analyze the raw data and write profiles (and laser energy?) to the tree.
Cooling Water
Should be kept below 2μS.
Related Pages
Diagnostics
Magnetics (Local): Reentrant array | Toroidal array | Saddle coils | Shell eddy sensors
Magnetics (Areal): Poloidal flux loops | Loop voltage | Diamagnetic loop | IP Rogowski
Spectroscopy: Thomson scattering | ChERS | X-ray spectroscopy | Spectrometry | Vacuum UV spectroscopy
Microwaves: Reflectometry | Interferometry
Physical Probes: HFS edge probes | LFS SOL probes | RFEA
Operational Diagnostics: Ion gauges | Coil current monitors | Thermocouples | RTDs
Water Systems
Cooling water: TF magnets | Vacuum vessel | Thomson scattering | Robicons
