 Sat Jun 8 13:11:52 2024, Carsten, General, Put the go4login in atplaser .bashrc
|
Put the go4login in atplaser .bashrc in order to avoid that one always has to go to the go4 directory to set the environment variable.
go4login64 is now executed automaticlally and the environments are now set every time you open a (bash) shell.
A fixed version 6.3 is used. The login file might be changed back after the beamtime. |
|
Sat Jun 8 12:45:05 2024, Carsten, DAQ, Temporary change of RF signal
|
The setting was 1.540974 MHz and division factor 68 (for a 200 MeV/u) beam, and the signal was taken from a signal generator.
I now switch to the "real" RF signal from the accelerator (~400MeV/u), that is 1.9693 MHz and the factor is set to 88.
This should be set back for laser tests or adjusted when we have the real decellerated beam. |
|
Sat Jun 8 12:02:20 2024, Carsten, Detectors, Test Particle Detectors - Det South not working
|
With the test beam from ESR I started to have a look at the PartDets.:
North outside: Works properly with a voltage of 1450 V
South outside (behind cooler) : no signal.
Later (when Danyal is here) we will check detectors cables etc., and if required put the north detector to position south and mount the untested (newly made, but with "old" material and PMT) spare detecotr to poistion north. |
|
Fri Jun 7 17:10:45 2024, Sebastian, General, XUV LED
|
Maximum XUV LED Voltage: 6.5V |
Fri Jun 7 15:29:50 2024, Rodolfo, Detectors, Stored beam @ ESR 
|
| One of the first PMT signals from the stored-ion beam @ ESR |
|
Fri Jun 7 11:14:04 2024, Rodolfo, Laser, Trigger-signal for MRC
|
We are using a 2-Channel Function Generator (from Textronik) to generate the trigger signal for the MRC Beam Stabilization.
The triggers are (according to the MRC nomenclature):
- Tmin = 500 us.
- T1 = 40 us.
- T2 = 460 us. |
|
Fri Jun 7 09:15:31 2024, Carsten, DAQ, Updated Channel List
|
|
|
Thu Jun 6 19:51:11 2024, Carsten, Accelerator, ESR crew left after persisting problems with ESR magnets
|
No beam today.--. |
|
Thu Jun 6 19:47:01 2024, Carsten, DAQ, Exchange of Mesytec CFD/shaper - noise on signal lines from ESR magnets
|
Jan exchanged the Mesytec CFD/shper since it could not be "remote controlled" anymore. The new one has different shaping times and delays.
It is noted the threshold range is rather small.
With the new shaper only the x100 signals could meaningfully discriminated etc.
After start of the ESR (magnets etc.) the signals of the 10x channels see quite some noise that makes it more difficult to adjust the thresholds for the low signals. |
|
Thu Jun 6 19:42:20 2024, Carsten, Detectors, Exchange of amplifer channels / cables channels / HV voltage cables for PMT south
|
In order to check if the problem of regular burst of pulses on the PMT south is related to amplfier channels and or the HV cable, the cheannels of the amplifiers in the ESR were changed. Likewise, a different HV cable is now used for the supply of the PS.
The problem still persists. It is visible on all three cable lines from ESR to Messhuette (100x DAQ1 cables , and 10x / 100x cables DAQ2). |
|
Thu Jun 6 09:39:23 2024, Carsten, DAQ, Preliminary Channel Table (DAQ1 and DAQ2)
|
|
|
Thu Jun 6 09:23:53 2024, Konstantin Mohr, DAQ, Timing
|
The best way to adjust the bunch-laser timing is to start go4 (mbs must be running) from atppc023. Therefore use x2goclient and use the predefined session to access LXG1297. Start go4 as usual (Entry 10 + Entry 11).
With this preparation one can directly observe changes in the relative time between the common stop trigger and the photodiode signals (see Screenshot 3) when rotating the upper channel's fine adjustment wheel of the right dual timer above the laser table (see Screenshot 2, Don't touch the coarse adjustment wheel directly above!!!).
To ensure proper operation of Go4 make sure that it is closed in the ssh-session after the correct timing has been set!!! |
|
Thu Jun 6 08:16:36 2024, Danyal, Accelerator, scraper info by Robert Boywitt
|
attched is more info about the T-scrapers (E-cooler) by Robert Boywitt (Tel: 2067 or 3357) |
|
Thu Jun 6 07:54:15 2024, Danyal, General, pressure gauges and ion pumps
|
yesterday (05.06.2024), firstly, the two ion pumps (underneath the fluorescence chamber) were switched off by the vacuum group (Björn Mai, Tel: 3438). Secondly, the two pressure gauges (located near the target) were switched off. The pressure gauge at the fluo chamber is called E02VM3x and the pressure was 5.5e-11 mbar. The other gauge is called IG2 and located further south, it measured 3.7e-11 mbar. That was when ion pumps were still switched on. Since ~10:45 (05.06.2024), the two ion pumps and the two ion gauges are switched off. There was no measurable change in the pressure after switching off the ion pumps. |
|
Thu Jun 6 07:12:49 2024, Konstantin Mohr, Laser, T-Scraper 6x
|
The T-Scrapers can be driven by DeviceControl, which must be started from a console. To do so, first open the app-launcher and then select "Device Control", which is found under "Betrieb & Steuerung". Then select the appropriate context (should be the name of the experiment). After a short time the device icons will be present. The scrapers can be found in the last four columns and the second last row (see screenshot 1). By default, they should be colored like the following: DS1VU: green, DS1HA: yellow, DS2VU: green, DS2HA: yellow.
To test the scrapers, I made a measurement of the current laser position.
|
motor | laser position (mm) | screenshot | |
DS1VU (GECEDS1VU) | 0 | 2 | |
DS1HA (GECEDS1HA) | -10 | 3 | |
DS2VU (GECEDS2VU) | 2 | 4 | |
DS2HA (GECEDS2HA) | -8 | 5
|
Note that the interlock of DS2VU is overridden when DS2HA is at 3mm. The interlock of DS1VU is overridden when DS1HA is at -4mm. The horizontal scrapers can only be moved when the corresponding vertical motors have reached their inner end positions.
Compared to the last position of Bi the horizontal and vertical positions deviate by approximately 5mm at all axes. However, since the electron cooler was completely dis- and reassembled in the meantime, it seems to be a reasonable starting point. |
|
Wed Jun 5 19:22:43 2024, Carsten, Konstantin, Rodolfo, Detectors, PMT tests and preliminary thresholds
|
For all channels of the CAEN CFD the width of the logic signal is set to 255ns (maximum) to mitigate potential double pulses. For the very low count rates of the experiment this is not problem.
Tested and (partially) set-up UV PMTs and Chenneltron with a UV LED.
- The UV LED does not give a useful signal for the small-band VUV PMTs.
- In general, (using the new cables?) it seems that the cable noise is very low and can be easily discriminated.
- PMT south (the broadband) sees a regular "strong" pulse-train/burst of photon signals. Therefore, the PMT was exchanged against a different one (SolarBlind ET Enterprises Model 9422, SN1042) - same result. New data sheet is attached.
- The channeltron has a rather broad pulse height distribution but very low background. CFD thresholds can easily be set. Very likely the best detector to adjust the laser timing?
- Channeltron Head : -2.5 kV , CFD threshold 8 mV.
- PD SO threshold needs to be checked (in Go4 the number of counts of PD SO is much lower than of PD NO). Present values: both 10 mV.
- Voltage PMT north / middle (both small-band) : -2600V, PMT south (replacement): -1500V. All thresholds: 15 mV
- CAEN CFD must be switched back to LOCK or it otherwise produces additional background
Both DAQs run with about 2 laser scan cycles, 201 steps. 90 shots each...
date written to files.
|
|
Wed Jun 5 14:17:36 2024, Carsten, Accelerator, Distance Cooler Detector
|
Calculation from Helmut Weick (copied from E142)
Distance e-cooler to particle detectors chamber:
“This is half of ESR plus distance target - detector. This even is on the web page”
54.28 m + 21.64 m |
|
Tue Jun 4 22:54:02 2024, Rodolfo, Detectors, PMT - Manufacture - Test Result Data
|
|
|
Mon Jun 3 19:42:06 2024, Rodolfo, Laser, Laser-beam through E-Cooler
|
UV-laser beam is now going through the Electron-Cooler.
Telescope settings:
- Plan concave lens -500 mm
- Plan convex lens + 1000 mm
- Distance between the both linses: 535 mm
- Position at Long Travel Stage: 60,0 mm |
|
Mon Jun 3 18:24:44 2024, Rodolfo, Detectors, PMT arrangement
|
The picture shows the actual configuration of the PMTs.
We are using a 4-Channel High-Voltage supply. The channels are labeled according to the PMTs names.
The suggested operation voltages are:
- PMT Nord (Type 9423, SN. 652): -2600 V
- PMT Mitte (Type 9423, SN. 653): -2500 V
- PMT Süd (Type 9422, SN. 1049): -1750 V |