Spectroscopy

NOTCam spectroscopy mode uses the 3 lamps installed on the inside of the baffle lid. The Argon lamp usually switches on with a delay, but the delay time is variable. The problem arises in automatic calibration scripts, since we have no feedback on when the lamp is actually on. The recommended script for night-time in-situ calibrations, "notcam.easy-calib", has therefore been programmed to switch on the Argon lamp as early as possible (as soon as the TV is switched off, while mirror covers are closing), which gives the lamp 40 seconds to come on, and then do Argon exposures for all setups first. But even in this mode, it happens that there is no lamp light. Tests show that the lamp can come on relatively fast, i.e. within a few seconds, or relatively slow, up to 2 minutes.

With the help of Francesca Ghinassi of the TNG we tested our Argon lamp with their power-supply, which is different from ours, and it turns out that the lamp comes on with no delay. The TNG uses fix current AC power supplies, while we have a dual-mode power supply, but it turns out that the AC mode of our device is somewhat different than the definition of AC mode in the fix current AC power supply. A new power supply for the Argon lamp (plus a spare) of the same kind that TNG uses was ordered, and is expected to arrive this month. If this solved the problem with switching-on the Argon lamp, the calibration script can also be modified, and made more (time) efficient.

The NOT Exposure Time Calculator was upgraded to include Z- and Y-band spectroscopy for NOTCam.

Thomas Augusteijn 2016-05-05