OTCCD CCD18 Test 14-Nov-97

The system setup was CCD18 in dewar 2 connected to first gen. SDSU controller SDSU1 using cicada V2.0b3. Sparcstations usage was Monaro used for data taking and mephisto was used user interface.

Aim

To get orthogonal transfer CCD working

Test Pattern Position

Test pattern positioned in slot closest to the projector and micrometer set on 0.25

Results

When connected warm

1. all temperature sensors worked and read ~294K
2. bias frame saturated except for overscan and first 20 rows.

When cold, ie at 187K, CCD worked OK except for a light emitting diode at approx [218,407] produced a bright disc with a tail.

Quick investigation of ways of reducing light emitting diode by varying parallel clock voltage levels

Image 10 sec dark	FSP_LO	FSP_HI	IAP_LO	IAP_HI	Center Height	Tail	Notes
ccd0159	-3.0V	+3.0V	-3.0V	+3.0V	18300	1600
ccd0160	-4.0V	+3.0V	-4.0V	+3.0V	18000	1700
ccd0161	-5.0V	+3.0V	-5.0V	+3.0V	18000	1700
ccd0162	-6.0V	+3.0V	-6.0V	+3.0V	18200	1700
ccd0163	-7.0V	+3.0V	-7.0V	+3.0V	18400	1700
ccd0164	-8.0V	+3.0V	-8.0V	+3.0V	18200	1700
ccd0165	-9.0V	+3.0V	-9.0V	+3.0V	18200	1700
ccd0166	-5.0V	+2.0V	-5.0V	+2.0V	18200	1700
ccd0167	-5.0V	+1.0V	-5.0V	+1.0V	18200	1700
ccd0167	-5.0V	+4.0V	-5.0V	+4.0V			image streaks

Result, affect from light emitting diode does not seem to be varied by changing parallel clock voltages.

Set at parallel low=-5 and high=+3.0 and measured gain and noise

Frame Store/Guide Area

• Gain 0.174 e/ADU
• Read Noise 4.368e­ in frame store area
• Read Noise 3.3e­ in overscan area
  

Image Area

• Gain 0.196 e/ADU
• Read Noise 5.695e­ in image area
• Read Noise 3.9e­ in overscan area

Some Images

• bias
• dark 30 secs
• flat

Some Images in gzip form

• bias
• dark 30 secs
• flat

Dark Current at

CCD temperature is not getting lower than 187K, therefore warm up and check cold strap before doing any more characterization.