Morning shift
08:16 - as run 18, target off
9:00 Increased storage time to 5 minutes. Aquired data after initial beam loss. Attach 1 &2. Far less H2+ vs D.
Temps OK
Rates as before
10:00 beam being optimised to reduce 2H+ content
Rates in aida 13, 14 suddenly spike as during overnight. Checkloaded repeatedly. No effect. Increased thresholds in 13, 14 to 0x32 bringing them in line with 15,16.
12:50
We started test with beam
Test1 ( Attached 12-52-55)
Horiz. offset: 8mm
Max vuel on 1.5MeV =1480 counst
Test2
Horiz. offset: 7mm
Test3
Horiz. offset: 6mm
target density=2.4E11
Test4
Horiz. offset: 5mm
target density=from 1.7E11 to 2.5E11
Test5
Horiz. offset: 4mm
target density=from 5.6E11 to 1.1E11 several fluctuations
Test6
Horiz. offset: 3mm
target density=1.1E11 several fluctuations. Until now we do not see a clear signel from the reaction!
Test7
Horiz. offset: 2mm
target density=1.1E11 several fluctuations.
Test8
Beam back again. Coasting beam. Detectors IN
Horiz. offset: 8mm
xy and energy histograms - attachment 12 and 13.
Test9
Bunched beam Detectors IN
Horiz. offset: 8mm
xy and energy histograms - attachment 14 and 15.
Test10
Horiz. offset: 6mm
xy and energy histograms - attachment
target:1.6E11
xy and energy histograms - attachment 16 and 17.
Afternoon shift
From previous overlap tests we can see that moving the beam position does cause a change in the number of events observed in the detectors.
But the change in events appears to be due to beam halo hitting the detectors rather than elastic scattering. New approach required.
We have varied the beam position (horizontal) in 1mm steps from 0mm to 9mm (the maximum allowed). We do this with the target ON and then with the target OFF.
Integral of events ~1.5 MeV taken . Difference between the target and no target plotted to gauge overlap position.
Note we have moved left arm fully out as we were worried about beam hitting dssds on injection. Will check overlap with right dssds only as left dssds have very low rate at this position.
We have determined the overlap position is about 7.0mm horizontal
Attachment 18 shows initial scan.
Attachment 19 shows a second scan in the region we highlighted as possible overlap. |