ThAr exposures

Following is the plot of the time evolution of the intensity measured on the two fibers from the two ThAr calibration lamps. "Fiber A" is illuminated by "lamp4" (or "ThAr1"), "Fiber B" is illuminated by "lamp5" (or "ThAr2"). The data are obtained from the "spot" files output by the pipeline for every ThAr calibration exposure. Only the last exposure of the day, taken just before the beginning of the night, is considered.
A trend different from flat might be due to a lamp change, a lamp aging, a change in the injection (alignment), or in the fibers (stress). For diagnostic these plots have to be compared to the ThAr lamps history, the flat fields and the day sky exposures.