Hydra Report - May 2002: System work & Eng Results

Detector, dewar and Arcon work, Ramon Galvez H., June 2002

CCD Dewar

1. Leak tested.
    
2. Determine gasification rate = 1.8 SCFH
    
3. Determine As Is Thermal Radiation Load = 3.8 Watts
    
4. New vacuum valve installed.

CCD & Arcon

1. Dark Current = 1.43 e/pix/hr ; Conditions = Bin 2x2, Gain 1, all sorrounding rooms and dome lights ON.
    
2. Dark Current = 0.88 e/pix/hr ; Conditions = Bin 2x2, Gain 1, all lights OFF.
    
3. New ADC bd prepared + tested ( s/n4 new batch). Got no more missing codes around 15k ADU.
    
4. Video original and spare bd. Noise comparison : both at 3e.
    
5. Not a single crash. Neither during exposure tests nor while downloading.

Dewar Cryogenics

1. A new LN2 refill and solidification device was designed. I had the good advices from Brooke on this. Tested in the lab and, along with Daniel, on the telescope.
    
2. Cryo Status : 24hrs hold time, one daily refill. Cryo system ‘tuned’; as a result the refill is done without necessity of vacuum valve control.