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Message ID: 622     Entry time: Thu Jun 13 00:50:33 2024
Author: JM, JS 
Subject: Run 64 - beam on target 

01:50

Right arm at 64.60 mm

Left arm IN at 36.54 mm

MBS working - hopefully

Target ~3E11

Injection ca. 3E7

horizontal beam position 8.75 mm

vertical beam position  -5mm

Changed electron cooler set point to 247.3 V

Read value 246.75 V

Collector current 4.3A

Histograms and statistics zero'd. Code reset

Rates OK. Temps OK.

 

NOTE. Between 23:45 and 12:45 the electron cooler was off? We called HKR and they turned it back on. Are we using the same cooler settings? Is the cooler still definitely working properly? Ask Claude in the morning

02:30

The target density started to oscillate between 2e+10 and 3.5e+10. However, the pump speed seems to be stable.

03:50

The oscillations seems to deepend between 1e+10 and 6e+10. Additionally the E1 pump slowed down to 815. As Nikos suggested during the tuning, I tried to lower the temperature from 41K to 40.8K.

04:00 - 04:30

No major change was observed, thus I increased the temperature to 42.2K in order to try to get the pump to the nominal rotation. After 10 minutes, the pump slowed down to 810 and the pressure in E1 reached 2.2e-1. Since increasing the temperature seemed to have a negative effect, I slowly decresed the temperature with steps of 0.2 K, until reaching 40K. At this point, the E1 pump returned to 819/820, the pressure of E1 lowered to 1.6e-1 and the target density seems to be more stable with a value of 2.8e+11.

05:00

The target density started decreasing to 1.5e+10 and the pump speed slowed to 815. I've tried to lower the temperature to 39.8K, but the target density started to decrease. Thus I've set the temperature to 40.2K. The pump speed raised to 818 but the target density remaind at 1e+11 level with oscillations between 8.5e+10 and 1.5e+11. After some minutes, it started slowly increasing towards the 2e+11 region. The E1 pumping speed is stable at 818 and the pressure of E1 is 2.02e-1.

05:10

Electron cooler off, restarted 10 minutes after by calling HKK.

05:30

Target density at 1.5e+11, however, the E1 raised to 2.3e-1 and the pump speed decreased to 810. Since going down seemed to solve it, I decreased the temperature to 39.6K. After 5 minutes the E1 lowered to 1.9e-1 and the pump speed is going up (currently at 814). The target density is at the same level of 1.5e+11.

06:00

Again the target density started to go down, as well the speed of the E1 pump and the E1 pressure reached 2.3e-1. I lowered the temperature to 39.2K: the target density raised to approximately 3.8e+11 (and keeps going up), the E1 pressure lowered to 1.9e-1 and the E1 pump speed started increasing from 810 to 815.

06:30

The target density starting going down again, the E1 started increasing to 2.3e-1 and the E1 pump speed decreased to 810. I lowered the temperature to 38.8K, the density raised to 3.5e+11, the E1 pressure lowered to 1.9e-1 and the pumping speed starting increasing.

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