07:00
After putting the target back, we observe strong periodic (5 s) fluctuations going from 3E11 to 5E12. The reason is unclear. One may warm up the target to solve this, but will ask Nikos later instead.
The target may be a bit too thick for our purposes, and the luminosity will vary greatly depending on injection vs. target fluctuations timing.
Rates OK. Temperatures OK. Merger OK.
System wide checks as before.
07:30
Moved detectors fully out to check elastic and signal rate in this configuration.
Half of DSSD BR was missing. Checkloaded. Solved.
Moved to run 48. Target still unstable.
08:23
Beam issues. Called HKR. Target out.
09:00
Still no beam. Increased target temperature to 29K from 28.5K. It seems the fluctuations disappeared.
Rates as before.
10:22
Beam might be back but people are checking the steerer. Target in. Started run 49. Detectors still out.
10:13
Some beam. HKR is still working on it.
Data rate up to 2 MB/s. Merger events merged matches. However Stats do not seem to have increased. This is the second time I observe this. |