Summary at start of run

Read through the runbook and end of run summar and the situation appears to be:

1. The check of the tune showed it was OK, although a bit of beam (or halo) clipping 4mm collimator

2. There are some changes to the gas filling scheme - Jamie should be present for the next one.

3. Evidence that the gas pressure is dropping slowly - need to watch this

4. Trigger is Coinc.OR.SS_2.OR.PD.  Rate at this is 200/s at 4epA (50/50 Coinc and S2_2)

5. Suggestion we could increase the beam a factor of two to get back to the same coinc rate.

Analysis.  Looking at the rates I see:

Running at 66 pnA and see about 4,000/s triggers and 3,200/s accepts. Scaler 9 over 40,000/s.

Looking back in run book the max trigger accept rate we see is about 3,800/s.  Could double beam and gain only

modest increase on accepted rate, but at cost of faster damage of detector.  Suggest we run

like this for a bit and make sure all is well.

Took a look through the spectra.  All ADCs OK, but no TDC signals.  Checked past saved runs.  There up

to run 98.  The next saved on disc is run 104 and they aren't there.  Nor in any saved runs after this.

Looked at electronics and reason clear as the module providing the TDC trigger (lower section of a

429 unit) has no input.  Eventually determined that it would make sense if this unit was operating

in 2 x 8 mode rather than what it is currently set on (4x4).  Switched this over and now working OK.

Assume this was changed inadvertently during all the work on the chamber yesterday.

0300.  Running again and all ADC and TDC spectra make sense.  Off for a cup of tea.