16:30
Run 40 started.
D+ beam deuterium target. D+ beam energy is 0.75 MeV/u. (beam calc calculation is 0.7619 MeV/u)
Beam calc - Attachment 1
Target density is about 1e12 at/cm2
All four detectors positioned fully out and stationary.
Left potentiometer = 18.86 mm
Right potentiometer = 19.8 mm
Ring cycle time is 30 seconds. Note we see some hydrogen in in the spectrum, this disapears after a few seconds.
Target T1=30.1K, T2=31.9K.
Nozzle position x=-2.96, z=1.72 mm
YR09-Etarget pressure = 2.55e-10 mbar.
Cooler set value = 439 V, 15 mA. Read value = 439.81 V, 12.88 mA
All leakage currents look good
Beam position. Vertical =0.0mm , Horizontal=-1.5 mm
Beam intensity ~1e8 on bunched beam, 1e7 on coasting. This is less intensity than higher energies, may require an increase in the morning.
Data rate ~ 403kB/s
Lowered slow comparator threshold to 0x24 (360 keV) since we decreased beam energy.
18:36
Temps OK - attached
Rates OK - attached
Merger OK - attached.
Spectra appear to have a flat background to the right of Rutherford that was not there at higher energies.
The xy plot also does not seem to be as centered.
21:17
Tems OK
Stats OK
Merger OK
Leakage current stable
Run continues OK
Ring vacuum 2E-10 mbar, likely getting less target.
02:00
Temps OK
Stats OK
Merger OK
Leakage current OK
Run continues - attached
Ring vacuum as before
04:20
Temps OK
Stats OK
Merger OK
L. current stable
Run continues
Ring vacuum as before
07:00
All checks OK
Leakage currents remain stable.
We have accumulated good statistics. 3He peak does seem a bit off. Cooling could be slightly off. Problem is not so bad looking at Ey compared to Ex. Online code uses pulser calibration only so may be a bit off depending on Ey/Ex.
Target density has been stable in the 1e12-2e12 at/cm2 range overnight. A bit more would be good.
Will ask on call operator to check cooling and try to increase intensity.
Run stopped gas target off.
07:30
Note during the tuning process we observed the same structure at 2.5 MeV in DSSD 1 as we did overnight that may overlap with the 3He peak. Perhaps it can be removed offline. See final attachment
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