beam: 205Tl81+ (no scraping , Al ~1g/cm2)
energy: 400 MeV/u
storage time: 10 hr
S2: 0/35 mm
s6: -20/7

purpose: data with TARGET ON

Detector position (CsISiPHOS):  out of the ring
Detector position (MWPC):  -60 mm

run start at 20:21,  run0540.lmd 
file running: 0558.lmd

_______________________________________________________________________________

time when accumulation starts: 08:21
time when storage starts: 09:27
time when storage ends: 19:27
I_cooler during storage time: -1 mA (20 mA)

I_cooler = 180 mA  


I_SIS: 1.8e9      
ESR particles after stacking: 3.1e6 (offset 4e5)
Number of stackings:  200 
Target ON density: 4.15e12 
Target on time for measurement: 10 mins (by event mode)      
time spend at manipulation 13 : 10 mins
(i.e. time for which electron cooler is on after gas jet) 



I_ESR (10:34): 2.78e6
I_ESR (11:07): 2.53e6
I_ESR (12:07): 2.2e6
I_ESR (13:43): 1.7e6
I_ESR (14:00): 1.6E6
I_ESR (14:43): 1.5e6
I_ESR (15:24): 1.43e6
I_ESR (16:19): 1.3e6
I_ESR (17:03): I.IIIeVI
I_ESR (18:20): 1.15e6 (frozen screen) 
I_ESR (18:50): 9.5e5
I_ESR (19:27): 8.5e5




NTCAp file:
SC_2020-04-06_00-59-46
\IQ_2020-04-06_00-59-38
IQ rate: 8 MS/s
(saved in drive : O)

copy and repeat the above (below the line) for every storage time measurement/

cheers!

We saw reduction in ESR beam life. It turned out that FRS has opened valves and venting caused us reduction of the quality of vacuum in ESR leading to beam loss. We manged to closed GEE5VV so that now beam is stable somehow.


how could you guys!!!!

arrrrgggggggg!!!!!!!

cooler component GECEBG2T again had to be reset.

Many thanks to Sergey and Nikos we have tested the connection of the new control system for turning on and off of the gas target.

Connections:

For the test event machines 12 (event 162) and 14 (event 163) were chosen for gas target on and off. The old Pulzzentrale code remains unchanged on 10. The middle output of the TIF editors can then be connected to the gas target control.

The created pulses were measured on the oscilloscope and hat the duration of 1us and amplitude of 5V.

The gas target control then produces the required long pulse which comes out as a BNC connection. If in the local mode, gas target can controlled by out-on and out-off. For the above scenario, we need the event mode.

The output of the gas target control is connected to the ESR-Messhuette-Panel number 2, which goes back to Messhuete and form there to the top of ESR.


All connections are working properly until the gas target itself.

Software:

Different subchains can be activated and deactivated on demand. Also their duration can be changed on the fly, but currently a change in other settings (such as Quadrupoles) might reset the duration values to their default.

e127: https://docs.google.com/spreadsheets/d/14m8WcCq1erx6HqWJRK7TLbCx121IkjqGa5l-frf4YjI/edit#gid=0

e121: https://docs.google.com/spreadsheets/d/10MUzA5-Ilf2WzCyNj8u_KSG6yzPg0e4vtZGGPFB3K-k/edit#gid=0

1) From SIS, 206Pb67+ @401.17 MeV/u goes to FRS where only SEETRAM is placed in the target area to strip off 206Pb67+ to get 206Pb81+.
2) There is 206Pb81+ (H-like primary beam) inside ESR at 400 MeV/u.
3) The ESR team is now trying Stochastic cooling with 206Pb81+ beam at 400 MeV/u.

1) ESR team is successful with the Stochstic cooling of primary H-like 206Pb81+ beam @400 MeV/u.
2) Now, they are trying for stacking of the beam.

Yuri and Helmut have been extensively involved in tuning and optimizing of the FRS.

26th March, 2020 (Evening setting):
1) 206Pb67+ beam from SIS @401.17 MeV/u.
2) SEETRAM in target area of FRS is used for stripping the beam from SIS to get 206Pb81+ and is then transported to ESR @400 MeV/u. (SEETRAM consists of three Ti foils of ~10 um thickness which are used for stripping purpose (more info: https://www-win.gsi.de/frs-setup/ ))
3) SL1 slits are opened +-10 mm to get rid of other charge states of 206Pb and only transport 206Pb81+ through FRS.

27th March, 2020 (Evening setting):
1) Different target (Be 1-6 g/cm2 with Nb backing) and degrader (Al)thicknesses are used for the optimization of 206Pb81+ with matter in FRS to get the beam with @400 MeV/u in ESR.
2) 206Pb67+ beam from SIS @540-560 MeV/u.

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.

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).