Update:
W decided at 8.00 to stop, check the tune, retune and get back going. This has nearly, finished but it is a very long process indeed - note for future - this takes AT LEAST 12 hours, if one is systematic about it.
We tested the tune as it was - it was OK, (90% transmission or so acdording to a straight ratio of the cups) but there are a fair bit on the 4mm collimator.
Marco then tuned, and improved it with a high intensity tune, reduced the rate on the collimator by at least a factor of 5 - maybe more. Good position on scintillator - see photo below.
We have since pumped out and run several tests with the window in, but no gas: (1) 10mm collimator on first target ladder, nothing on second - transmission was about the same, measured the same way. Rate similar to same test we did a couple of days ago. (2) 5mm collimator and blank second target - result about the same. (3) 5mm collimator and scintillator in - photo below. Beam spot blew up a bit compared with no gas. See below. (4) 5mm collimator and PD2 (5) 5mm collimator and blank. Ran this to disk. and (6) CH2 target. This made no sense and we got a lot of horrible ate of this so we stopped it.
We saw noise in S2-2 when we had no gas. It was bad - 1200Hz with no beam - all from S2-2. When we put gas in, it all went away! We suspect that it was a gauge that we disconnected, perhaps.
Waiting for beam, as buncher has now tripped.
Note that full cycle (pump, flush, vent, tune, flush, pump H2) - with all the tests as you go along, took 12 hours!
The pictures below are tunes without and with the window. From Mikes iphone. !
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