ID |
Date |
Author |
Category |
Subject |
Year |
567
|
Sun May 30 14:40:55 2021 |
Jan, Sophia | Detectors | real detector assignment | 2021 |
************************************
GEM1800 @ 90deg (xray1)
GLP2000 @ 35deg (xray2)
GEM3000 @ 145deg (xray3)
************************************
Was noted wrongly in most calib runs. |
568
|
Sun May 30 14:48:09 2021 |
Jan, Sophia | Calibration | run0215 - crap | 2021 |
|
569
|
Mon May 31 10:08:42 2021 |
Jan, Sophia | Runs | E127b runsheet | 2021 |
|
570
|
Mon May 31 14:38:33 2021 |
Sophia | Calibration | Runlist for X-ray detector calibrations after the experiment | 2021 |
The by Jacobus Swartz created table in entry 335 extended by the calibration after the experiment. |
571
|
Wed Jun 2 09:14:04 2021 |
Jan | General | Telegram Chat Export | 2021 |
Attached is the exported Telegram chat.
There is the simple PDF and the zip-file containing the chat in json-format as well as all media files. |
572
|
Tue Jun 8 15:06:17 2021 |
Shahab | Analysis | Beam lifetime | 2021 |
measured beam lifetime after the second deceleration using parallel plate Schottky detector and the RSA5103 spectrum analyser. Analysis code can be found here:
https://github.com/xaratustrah/e127_scripts/
The plots here were produced using the script:
https://nbviewer.ipython.org/github/xaratustrah/e127_scripts/blob/main/lifetime_calculator.ipynb
UPDATE 2022-06-30:
Life times have been slightly corrected. Please see attachment.
Filename Start Frame Correct Lifetime [s] Mean [s]
pgamma_lifetime-2021.05.25.21.56.37.593_on.tiq 29500 1.43
pgamma_lifetime-2021.05.25.22.02.16.618_on.tiq 29500 1.55 1.49
pgamma_lifetime-2021.05.25.22.07.22.369_off.tiq 53500 1.75
pgamma_lifetime-2021.05.25.22.13.24.787_off.tiq 34900 1.89 1.82 |
573
|
Wed Jun 23 12:29:35 2021 |
Jan, Sophia | Calibration | Efficiency of the x-ray Detectors | 2021 |
For the x-ray detectors, efficiencies have been measured, before and after the experiment was performed.
The preliminary results of the determined efficiencies can be seen in the attached plots |
574
|
Thu Jun 24 09:43:01 2021 |
Jan Glorius | DAQ | Unpacker | 2021 |
The unpacker used for the production runs of E127b is located at
/u/litv-exp/unpacker/unpackexps/e127_TO_2021_with_ECL
It is also aliased for litv-exp user as: E127_unpack
This is for the data structure as documented here:
https://elog.gsi.de/esr/E127/346
As of now, this is compiled for ROOT v6-18-04 located here:
/cvmfs/csee.gsi.de/root/618-04/bin/root |
575
|
Thu Jul 8 13:39:34 2021 |
Jan | Calibration | Electron cooler parameters | 2021 |
Below are the results from the e-cooler voltage offset measurments done by Regina Hess et al. using the voltage divider (VD).
--7 MeV--
Sollwert GECEBG1E: 4008.3 V
Measured at VD: 3913 V
Offset: -95.3 V
--6 MeV--
Sollwert GECEBG1E: 3460.5 V
Measured at VD: 3364 V
Offset: -96.5 V
Below are the cooler parameters from ParaModi for our production runs.
--7 MeV/u--
UE: 3842.7V
IE: 50mA
BG1E: 4008.7V
BG1E dU: 120V
--6 MeV/u--
UE: 3290.833V
IE: 50mA
BG1E: 3460.4809V
BG1E dU: 120V
--energy calculation--
as described here
-- uncertainty --
for E108b we agreed on 10%
maybe further discussion is needed |
576
|
Thu Jul 8 14:07:19 2021 |
Jan | Calibration | beam energies | 2021 |
Table of ion energies calculated from cooler parameters
nominal energy | V_set | V_meas | I_set | E_ion | E_Error
|
6 MeV/u | 3460.5 V | 3364 V | 50 mA | 6.042 MeV/u | YY keV/u
|
7 MeV/u | 4008.3 V | 3913 V | 50 mA | 7.049 MeV/u | YY keV/u
|
Here is how the calculation works:
1. Find the voltage and current set values that were active during the measurement cycle.
2. These are only SetValues. For the current this is fine, but for the voltage you have to subtract an offset. This offset comes from the power supply and changes over time. It is measured regularly and the present offset you have to inquire with the ESR/cooler crew. For our beam time E127b in 2021 the offset is:
V_offset = -95 +/- ?? V (only for E127b)
The uncertainty has still to be discussed.
3. The space charge of the electron beam reduces the effective voltage seen by the electrons and thus reduces their energy. You have to calculate the space charge potential Phi_0 on the beam axis using the following formular:
using R_tube = 10cm and R_e-beam = 2,54 cm and all constants, you arrive at the ESR specific equation:
4. Now calculate effective Voltage and electron energy:
V_eff = V_set + V_offset + Phi_0
This time we measured the effective voltage for each energy, so we can actually use this values (V_meas) instead of V_set + V_offset.
E_e = e * V_eff
5. With E_e you can now calculate the ion energy by using the definition of the Lorentzfactor gamma:
gamma - 1 = E_kin/(m_0 * c^2)
In equilibrium, the left side of the equation is equal for both, electrons and ions in the cooler, leading to:
E_ion = E_el * M_ion/M_el
which gives the total energy of the ions.
NOTE:
In principle, this should be an iterative calculation, since the potential depends on beta and is then used to calulate beta or ion energy. But in practice a single iteration is precise enough, if beta was a good estimate. |
577
|
Wed Jul 14 14:46:05 2021 |
Jan, Sophia | Detectors | collimator geometry | 2021 |
We have measured the collimator geometry. The annotations of the variables can be found in the attached sketch
90° Detector GEM1800 | Distance[mm]
|
A | 2.4
|
B | 10.05
|
C | 2.1
|
D | 35.025
|
145° Detector GEM3000 | Distance[mm]
|
A | 2.15
|
B | 10.05
|
C | 5.025
|
D | 35
|
35° Detetektor GLP-2000 | Distance[mm]
|
A | 2.1
|
B | 10.05
|
C | 0
|
D | 13
|
|
578
|
Wed Oct 13 15:09:04 2021 |
Jan | Collaboration | K-REC cross sections A. Surzhykov | 2021 |
Attached are the theory K-REC cross sections as calculated by Andrey Surzhykov (August 2021).
They are done for 118Te52+ on H2 at 7.049 and 6.042 MeV/u as well as for 124Xe54+ on H2 at 7.049 MeV/u.
first column - photon angle (deg), second column - cross section (barn/sr). The results are given already in the laboratory frame.
Comment of Andrey on uncertainty:
Important question about theoretical model and, hence, accuracy of calculations. I used slightly improved "impulse approximation" that takes into account momentum and energy distribution of target electron (in initial state). By playing with the models for the Compton profile of target electron, I estimate the accuracy of calculations as 1 %. To be fair, it is rather conservative estimate. I suspect that for large emission angle (around 90 deg) accuracy is even better. But let us stay with 1 %. |
579
|
Wed Oct 13 15:15:53 2021 |
Jan | DAQ | root-file header for analysis | 2021 |
Attached is the header file needed for root analysis. |
228
|
Mon Mar 23 08:04:07 2020 |
Shahab, Laszlo,Yury | Runs | run entry - run094 | 2020 |
open file : run094
beam: 124Xe54+
energy: 10 MeV/u
purpose: data with TARGET ON and SCRAPER in scraping poisition--> We expect to cut the Rutherford for now on.
at the 3. shoot counting backwards from the end of this file the TARGET LEFT ON for the whole cycle --> got a burst of particles on the detector in
Target ON Mode as well. --> CUT OUT THIS ONE 1min PHASE!
Detector position (Si): -27 mm
GE01DD1IG position (Scraper): 9 mm
run start at 08:15, first file: run094_0001.lmd
run stop at 08:17, last file: run_094.lmd
_______________________________________________________________________________
time: 08:10
ON Rates
Si_X: 2 Hz
Si_Y: 2 Hz
Xray_35: 5 Hz
Xray_90: 84 Hz
Xray_145: 18 Hz
BaF_OR: ---
Si voltage: 60.02 V
Si leakage current: 4.32 uA
SIS particles before: 2.5e8
ESR current at injection: 4.5e7
ESR particles after decel.: 1e7
Target ON density: 3.8e13
copy and repeat the above (below the line) every 30 minutes |
283
|
Fri Jun 5 14:06:15 2020 |
Laszlo | Detectors | DSSSD and SCRAPER position estimate for Xe and Te experiments | 2020 |
We don't know the exact absolute positions of the detector (+scraper) and the beam. However, what we have to know is only these two relative positions respect to each other. To get this distance I use two methods:
1, combining the infos from the set position during the beamtime + the measured pg peak position on the detector. The pg peak position is defined only by the eye (because of the low number of counts in every case, it doesnt make much sense to make fits). Since we rely on the detector resolution, we would be never more accurate than ~ +/-1.5mm anyhow. The active area of the detector is 49.5x49.5mm2 with a 45° tilt in y.
2, MOCADI simulation of the beam and the pg peak. This is used only as a crosscheck.
3, The scraper had a small angle in y direction causing ~0.5cm shift to the upper direction. the length of the scraping edge is 7cm
-124Xe with scraper measurement:
- measurement
d1 = moved back from beam = 15 +/-.5 mm
d2 = DSSSD frame width = 8.85 mm
d3 = pg center on DSSSD = 7-7.5 bin = 21.7-23.2 mm = avg = 22.5 mm
--> pg from beam in x = -46.4mm +/- 1.5mm
--> pg on DSSSD from center ~ -3.28mm +/- 1.5mm
- simulation
x = -46.5 mm
y = 0 mm
- detector active area position
x = (-73.35mm) - (-23.85mm)
y = (-14.2195mm) - 23.5125mm
- SCRAPING: x=-35mm +/-0.5mm away from beam
y=(-20mm) - (40mm)
-118Te:
- measurement
d1 = moved back from beam = 16 +/-.5 mm
d2 = DSSSD frame width = 8.85 mm
d3 = pg center on DSSSD = 7.5 bin = 23.2 mm
--> pg from beam in x = -48.05mm +/- 1.5mm
--> pg on DSSSD from center ~ -3.28mm +/- 1.5mm
- simulation
x = -48 mm
y = 0 mm
- detector active area position
x = (-74.35mm) - (-24.85mm)
y = (-14.2195mm) - 23.5125mm
- SCRAPING:
x=-35mm +/-0.5mm away from beam
y=(-20mm) - (40mm)
notes during beam-time:
https://elog.gsi.de/esr/E127/97?suppress=1 |
1
|
Thu Sep 13 11:42:33 2018 |
Jan Glorius | Collaboration | Proposal | |
Attached is the beam time proposal submitted and accepted by the G-PAC in 2017. |
2
|
Thu Jan 17 08:45:43 2019 |
Jan | Detectors | Micron W1 DSSSD - technical information | |
Attached are the spec sheets and design drawings of the new DSSSDs from Micron.
Additionally, the 3D model made by Laszlo is also attached as stp and dwg. |
3
|
Wed Feb 6 10:04:23 2019 |
Laszlo Varga | Simulations | Background subtraction for 124Xe, 109In, 73As made by MOCADI | |
General remarks to the MOCADI simulations:
- scraper size vertically > (p,g) spot at the scraping position --> (p,g) can be separated by truncating the
backscattered Rutherford events in the energy.
- replacing the atomic masses to nuclear masses does not change significantly the absolute positions of the
(p,g) and the Rutherford. However, the (p,g) spot in the simulation seems bigger using the nuclear masses, than
in the 124Xe experiment with a factor ~1.6.
- going for lighter elements, the separation between (p,g) and Rutherford getting better, than slit can be
placed even more far from the beam in x (radial) direction. For 124Xe the minimal distance from the beam axis is
<4cm, for 73As it is <7.5cm.
- in the simulations the scraping is mostly until x=-inf. However, if the scraping is incomplete in x, we can end
up with underlying background events below the p,g peak (see the last slides)! The Rutherford cone gets bigger by
going down with A,Z. For 91Nb the minimal width of the scraper: x>6cm, for 73As x>7cm. Therefore, I suggest to
have a scraper width x=9cm. For the y, y=6cm should be safe.
- for lighter elements, the (p,g) spot size increases: in the simulation for 73As it reaches the detector size.
However, the (p,g) spot size might be overestimated, please read the 2. point.
|
4
|
Wed Feb 6 10:16:09 2019 |
Laszlo Varga | General | Study on scraping | |
A publication on scraping systems suggested by Siegbert.
In the study they have used cylindrical "high-quality" slits. "High-quality" stands for well polished surface
with surface roughness <50nm. The material of the slit is Tungsten Carbide. |
5
|
Fri Apr 5 05:46:20 2019 |
Jan | DAQ | running DRASI for (p,g) | |
We now have a drasi DAQ running for our (p,g) experiments.
The RIO we have it installed right now is: r4l-58
It shall be used with the user <litv-exp>
The DAQ-controle shall be done from lxg1275 inside a SCREEN SESSION named "daq"
tab 0 >> drasi
tab 1 >> logger
tab 2 >> rate
tab 3 >> stream server
tab 4 >> file writing (optional)
To check and control running daq:
login on lxg1275
> ssh litv-exp@lxg1275
enter screen session
> screen -x daq
DRASI
go to tab 0
> ctrl-a 0
should be quite, no errors showing, no terminal outputs
full restart proceedure
> ssh r4l-58
> cd esrdaq_2018/r4l-58
> ./start.sh (for det. triggered daq)
> ./pulser.sh (for internal pulser trigger)
> ctrl-c (for killing daq)
LOGGER
go to tab 1
> ctrl-a 1
should be quite, no errors showing, no terminal outputs
full restart proceedure
> ssh r4l-58
> cd esrdaq_2018/r4l-58
> ./logger.sh
RATE MONITOR
go to tab 2
> ctrl-a 2
rates should update each second
"incr" should be event rate per sec
"send" column should be reasonable value if data is written
full restart proceedure
> ssh r4l-58
> cd esrdaq_2018/r4l-58
> ./rate.sh
EMPTY STREAM SERVER
go to tab 3
> ctrl-a 3
empty stream should be running
number of processed events should keep increasing
you should see the number of clients connected
full restart proceedure (on lxg1275)
> empty stream://r4l-58 --server=stream:6002
WRITE A FILE
can be done by litv-exp from any lgx-machine
ROOT FILE:
> e127_unpack --stream=lxg1275 --ntuple=RAW,/data.local1/e127/pre_data/file.root
LMD FILE:
> e127_unpack --stream=lxg1275 --output=/data.local1/e127/pre_data/test.lmd
|