The attachment contains information on how to start and shutdown NTCap and bridge computer.

By changing the tune to Qx=2.33, Qy=2.36 the momentum acceptance was significantly improved. A variation of the cooler voltage of 10300 V was possible without beam loss. That corresponds to a momentum acceptance of 2.7 %. That should provide good conditions for longitudinal stacking.

Thanks to the ESR team !

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.

XY co-relation of DSSSD showing 206Pb82+ beam hitting the CsISiPHOS detector present in the inner pocket of ESR after the first dipole after the gas jet. 206Pb82+ is 
produced by ionisation of 
206Pb81+ due to interaction of beam with the gas jet.

Alex and Pierre-Michel applied 1500 V to the anode and adjusted the threshold in Messhute.
x1 signal was small & noisy and rest of the signals were fine.

10:51 am the CsISiPHOS is moved to 65 mm from 60 mm.The spot on the DSSSD is changed by 5 mm which confirms the hit of the beam.

11:05 
Detector is moved back to 60 mm.

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

Since last night, the signals from the p-side of all the Si pads were seen as negative on picoscope.
The signals from DSSSD, all n-sides of Si pads and CsI were positive which all are in MSCF-5.
Thus, I and RuiJiu, changed the polarity jumpers of MSCF 1,2,3 and 4(all the four jumpers inside the mentioned MSCF) and now hope to see positive signals from the p-side of all the Si pads.

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

beam: 
energy: 
storage time:

purpose: data with TARGET ON

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:           60V  
CH1 leakage current:   uA

CH2 voltage:           60V  
CH2 leakage current:   uA

CH3 voltage:           60V  
CH3 leakage current:   uA

CH4 voltage:           60V  
CH4 leakage current:   uA

HV2
CH1 voltage:           60V  
CH1 leakage current:   uA

CH2 voltage:           60V  
CH2 leakage current:   uA

CH3 voltage:           -50V  
CH3 leakage current:   uA

CH4 voltage:           -160V  
CH4 leakage current:   uA


SIS particles before:           
ESR particles after stacking:     
Number of stackings:
Target ON density:   
Target on time for measurement:           


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

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).

store 206Pb81+ beam inside ESR and measure its halflife. 
The HV of detector is off.
Start DAQ to record the ESR current in lmd file.
Nik is optimizing the gas jet target. So this file is still test run.

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.