23:40

Offline anlaysis shows two clear peaks for DSSD1 and 2 at very low energies close to the threshold. One must be elastics and the other a noise peak.

For DSSD3 the noise level is so exceptionally high due to the low threshold that nothing can be discerned from background.

Therefore I decided to stop the previous run and increase the slow comparator threshold for DSSD3 from 50 keV to 80 keV (same as DSSD2).

Run 65 started.

150 keV/u beam on target, Target overlap confirmed with lifetime measurement using bunched beam.

Detectors in with servos only. Both arms are IN and stationary.

Left potentiometer = 36.54 mm

Right potentiometer = 37.96 mm

Data rate has dropped to 1.5 MB/sec and merger is between 600k and 900k.

Stats attached at new thresholds.

Stats zero'd to see number of pause and resume overnight.

02:30

Some reaction counts visible on monitoring histograms (rate v low)

Checks OK, same fee (aida16 fails clock and adc as before)

pause info items after a few hours attached

05:00

We see the peaks much more clearly now. Rate is low but they are there. Target density looks like it has been fluctuating in the low 10^12 region. 

Note for this energy with 1e8 pps, 1e12 target density I estimate ~2 counts/h per detector for the 3He peak.from our spreadsheet calculator. After 6 hours of this run I saw about 10-15 counts in the peak of DSSD2, perhaps the same in DSSD3. DSSD1 has missing strips so is harder to see. This rate is about 48 hours for 5% (if we had 4 dssds).   

Checks OK

Leakage current of dssd4 has been stable at 40V for a while now. Pushed voltage up to 75V with leakage current stable. At 80V it started to go over current

Turned bias to 60V and have left on at this level. It looks stable. Perhaps in the morning it can be pushed to close to 100V.

07:15

Temps OK

System wide checks: 16 fails ADC calibration, 14 fails WR decoder

Rates OK, some Pause/resume statementes overnight. See attached x2

Merger OK. 1.5 Mb/s

Peaks clearly visible in two detectors.

08:25 All checks OK. DSSD 4 to 75V - OK.

09:10 All checks OK. DSSD 4 to 80V. Trying to improve target (2-4E12).