MDM Trouble Report for 2006 Apr 9

Telescope: 2.4m
Observer(s): Frank (OSU)
Instrument: MDM8K

Problem(s) Encountered:
First : the pattern on chip 04 described in earlier reports showed up
again...and became gradually worse.

Additionally and much worse : more than ha;fway through Kochanek's Bootes 
Field Observations, I realised that the streaks and hot pixel became
more abundant ALL over all the chips - I only caught that so late, because 
I was just checking chips 06 and 01 where that phenomenon occured latest.
At first, it looked like the classical 'warming CCD' with more and more hot pixels 
spilling charge everywhere. Thus, I immediately checked for a LN2
deficit or leak....but the gauge showed still less than 0.3 mTorr (a lack
of LN2 would have surprised me since I had filled the dewar every
12 hours and made sure that LN2 was 'dripping' in a thick gush..

So : I am a bit puzzled as to what that means. I did power the whole system 
down twice, filled once more with LN2 (just to make sure)...but
to no avail. The abundance of 'hot pixels' remains....

I have prepared a separate directory with example exposures that document
the progression of the severity of the effect - under 
/data/vesuvius/visitor/08_04_2006/Progression_of_problems/
one can find the details.

After 'flushing' in the morning for about 100 cycles, the streaks become less 
prominent, but are still there - furthermore : while flushing, often the
error message : no response from 2nd timing board (ltbS CLN)  
('cmd ltbS CLN' failed) came up.

As a precaution, I did power down..before going to bed.

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Submitted on 2006 Apr 9 [7:17:05]