Thanks to Sergey and Markus, stacking of primary H-like 206Pb81+ beam in ESR is achieved.

The stacking of the primary beam was established. There is continuous cooling on the injection orbit by stochastic cooling and by electron cooling on the stack orbit. (Time controlled operation of stochastic cooling could not be achieved due to controls issues). After stchastic cooling on the injection orbit the rf system decelerates the beam by 1.5 % in momentum and at the lower momentum electron cooling keeps the beam. The DC trafo shows accumulation of 10 injections of primary low intensity Pb81+ beam. Losses during the accumulation seems to be small.

Thanks to Nikos, stable H2 gas jet target with 10^14 particles/cm^3 is ready.
(More information can be found on: https://ulpc24.gsi.de/cgi-bin/jet.py?gasart=Helium )

We plan to measure:

1. Lifetime of H-like 206Pb81+ beam with two electron cooler currents:
a) 200 mA
b) 10 mA (so that recombination rate is less)
using MWPC (capture detector in outer pocket) and CsISiPHOS (loss detector in inner pocket). 

2. To find the efficiency of the MWPC.

Cross-section for capture and ionisation of 206Pb81+ with H2 gas jet target are calculated using GLOBAL code.
The ionisation (on CsISiPHOS) and capture (on MWPC) trigger rates are calculated for 206Pb81+ beam with 10^6 particles revolving in ESR ~2 MHz frequency with H2 gas jet target density ~ 10^14 particles/cm3.

The gas jet target is now being changed from H2 to Ar by Nikos.

Yuri reduces beam intensity in the ESR to reduce the countrate on the detectors.

ESR is open now

From Yury,

For now, measure the beam life time with 3 different electron current in the e-cooler,i.e. 200mA(default), 10mA, and 20mA. For each current, 4 sets of 30mins long measurements shall be taken.

Starting from 9pm Helmut and Sergey will come for setting up FRS

Attached are the instructions on how to change the electron cooler current for the lifetime measurements of 206Pb81+ beam (interaction with residual gas and electron cooler).

We see two species in the Schottky spectra during the beam lifetime measurement without the target. The one (probably the primiary beam) is significantly better cooled than the other.
So, we were wondering what is the other beam? Maybe the recombined ones?

Ragan and Ruijiu went in the ESR for short time to fix something with the slow control of the silicon detector.
After this, there is no beam in the ESR.

The HKR crew informs us that several machines in ESR are showing malfunctions.
The on-call expert cannot be reached.

Update (16:36): On-call service has been informed.

Update (16:48): ESR cycle stopped.

Yuri and Sergey (on phone) have investigated extensively the problem with having no beam in the ESR. The FRS has been checked and seems OK. The ESR is fine as well.
The problem seems to be the timing. Ths SIS and the ESR seem to be completely out of synchronization. The on-call service for the control system has been called. 

As we (RuiJiu and me) changed the jumpers of MSCF 1, 2,3 and 4 yesterday, now we see nice positive signals on picoscope.
Yuri and Sergey are still working on optimising the Tl fragments !

beam: 
energy: 

purpose: data with electron cooler current xx mA

Detector position (CsISiPHOS):  mm
Detector position (MWPC):       mm

run start at xx:xx , first file: run0xxx.lmd
run stop  at xx:xx , last file:  run0xxx.lmd

_______________________________________________________________________________

time: 

I_cooler =  mA



HV1
CH1 voltage:           V  
CH1 leakage current:   uA

CH2 voltage:           V  
CH2 leakage current:   uA

CH3 voltage:           V  
CH3 leakage current:   uA

CH4 voltage:           V  
CH4 leakage current:   uA

HV2
CH1 voltage:           V  
CH1 leakage current:   uA

CH2 voltage:           V  
CH2 leakage current:   uA

CH3 voltage:           V  
CH3 leakage current:   uA

CH4 voltage:           V  
CH4 leakage current:   uA


SIS particles before:           
ESR particles at injection:     
ESR particles after stacking:     
Target ON density:              


NTCAp file:
IQ_2020-03-27_21-02-31/0000xxx.iq.tdms
SC_2020-03-27_21-02-31/0000xxx.iq.tdms

copy and repeat the above (below the line) every 30 minutes

Alex goes to Messhute to check the signals from MPWC. After he completes, we start with the measurements with the primary beam )

There is problem with SIS
Run stop: 0257.lmd (at1:06)

The following shows the pattern for first measurement in ESR (gas jet is on for = 60*5 secs = 300 secs as it can be seen on step SC7 in pattern).
One injection cycle runs for ~ 6 mins.

In the picture below, a very nice storage of 206Pb81+ at 200 mA electron cooler current for no gas jet target can be seen in ESR. The measurement started at 02:24 and we will now finish it in 5-10 mins. We will now do two more measurements for I_cooler = 10 mA ans 20 mA.

In the ESR picture below, the decay of beam is very fast initially for few minutes and then the decay is constant. But why does it decay for first few minutes ?