THEMIS Solar Telescope

Because of the height of the THEMIS spectrograph, about 50 meters of cables are needed to connect the THEMIS control room with the different systems of the telescope and its instrumentation. These cables are used to power the mount and the different motors, to send commend to the telescope and to receive housekeeping and scientific data. This image of the month presents THEMIS cable reel and ill-known although fundamental element for the operations of THEMIS. A specificity of THEMIS is that the whole THEMIS instrumentation hangs under the THEMIS mount and rotates with it as the telescope tracks the Sun. THEMIS cable reel, located at the 4th floor of the THEMIS building permits to avoid the tearing out of the cables as the telescope rotate. About 6 meters of cable length are “stored” within it, compensating the lengthening of the distance as THEMIS moves.