First thing on shift, we requested the south hall lights to be turned off
to investigate whether or not LTOF11 (counting from 1) had a light leak.
A run was started with beam at 80mA (beam was shut off shortly
thereafter). In parallel we continued trouble
shooting the lack of right sector ADC's. The lack of south hall lights
did indeed shift LTOF11 adc spectra down and thus it was concluded that
there must be a light leak. This was verified locally (at the tube) with
the scope. The leak was located and fixed. LTOF13, which has a strange
structure to its bottom TDC was examined locally as well. The bottom PMT
exhibited good cosmic pulses but with an anomalous signal at a lower rate
and not seen by the top. This signal is spread out in time to 200nsec and
has a max pulse height on the order of 200mV. Priority shifted to the ADC
problem and several attempts were made to identify the root cause.
1) Right and Left ADC cable were swapped - we saw right ADC signal albeit
through the left crate.
2) Backplane common gate cards were swapped. Only saw left ADC signal.
3) ADC from slot 5 left was moved to slot 7 right and ADC from slot 7 was
removed and is in the counting bay. Only saw left ADC signals.
Current configuration has the right sector ADC's into slot 5 of the left
crate. With this, right ADC's are read-out (including cerenkov) but not
all channels look healthy.
**** The electronics map was updated to reflect this. ****
CODA seemed more stable at 250 Hz (no hangs).
Work is in progress to understand the cause of our right ADC problems.
This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:28 EST