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