There is no beam in the ESR due to some problem in the UNILAC.

Beam is back in the ESR.

There is no beam in the ESR again.

12:50 Beam is back again in the ring.
12:52-until now Kicker problem in the ESR.

Dear all,

unfortunately, the E128 experiment must now come to an early end. 
The problem(s) with the injection septum are severe and no work around solution (with acceptable risks) could be found. 
Several things were tried, but without hope. 

Many thanks to everybody involved during the preparation time and the shifts during the beamtime. 

Best wishes,

Wilfried

> Dear all,
> 
> unfortunately, the E128 experiment must now come to an early end. 
> The problem(s) with the injection septum are severe and no work around solution (with acceptable risks) could be found. 
> Several things were tried, but without hope. 
> 
> Many thanks to everybody involved during the preparation time and the shifts during the beamtime. 
> 
> Best wishes,
> 
> Wilfried

There is beam again in the ESR. The plan is to take beam until tomorrow morning. 

We overlapped the laser and ion bunch in the time domain. 
Therefore we delayed the bunching HF in order to see the PMT signal between bin 10 and 22. Before the signal Peak was in channel ~145-5 and difficult to gate on.
Afterwards we also have to shift the laser.
The new values are:

PD NO: 77.5
PD SO: 113
Ion bunch: 16.5 

until 15:15 we have measured with I_e = 100 mA (3 loops per file) 
E_cool HV = 225255 V 


after that (at 15:26) we changed to I_e = 200 mA (2 loops per file) 
E_cool HV = 225272 V 

after that (at 17:15) we changed to I_e = 50 mA (first 4 then 6 loops per file) 
E_cool HV = 225247 V 

At 17:15 we changed again the E-cooler current I_e = 50 mA  
(4 laser scan loops per injection) 
E-cool HV = 225248 V 

We changed PMT north and PMT south and tested them at 1500 V.

Both new PMTs are broadband.

PMT north and middle see between 2 and 7 kHz signal rate with a threshold close to the background noise.
PMT south still has the plastic cap on and is intended to be used as a reference for electro-magnetic disruptions. No signal was seen at 1500 V.
We fixed the signal cable of PMT south to the NIM-crate to get rid of background noise picked up by the cable.

Voltage SA_SZ (capture behind cooler): 1500 V (thin plastic scintillator)
Voltage NA_SZ (capture behind target): 750V (thick plastic, short absorption length)

Voltages and thershholds from thorium run, still to be verified.

Since we have ions in the ring now, we looked at the PMT thresholds and the widths. In order to do so we looked at the Raw Signal directly before the CFD and its output simultaneously. You can now set the threshold just above the noise. If the threshold is too low you will also see flat lines in the oscilloscope when triggered on the CFD output. New values:

PMT Mitte
---
Width: 200 -> 220 (60ns -> 90ns)
Threshold: 20 -> 5

PMT Nord
---
Width: 200 -> 220 (60ns -> 90ns)
Threshold: 12 -> 10

PMT Süd
---
blind.

In entry 36 one finds an additional PD NO peak around bin 100.
This was caused by signal reflection in the cable.
The problem was solved by adjusting the CFD threshold from 10 to 30.