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  laser spectroscopy on Be-like Kr, Page 3 of 5  Not logged in ELOG logo
ID Date Author Category Subject
  41   Thu Feb 27 21:23:02 2025 JensDAQPython Data Channels
Python variables and names in DAQ
Because the Name of variables in DAQ doesnt match the the real variables, here is List of the channels and what value is in this channel

UTC : Time in seconds (UTC time in seconds)
TIMERMS : Time in 100ms (UTC time, only digits after decimalpoint)
VOLTECOOL : E-Cooler scaled Voltage / Volt (value / -1.e+4)
COBRASETWL : Laser Frequency / MHz (Thz Output of WLM / 1e08)
ATOSWL : Gentec1 "COM5" Southwest / pW (W of Gentec / 1e12)
ATOSINTENSITY : Gentec2 "COM6" Northwest / pW (W of Gentec / 1e12)
ATOSNUMIFM : not used (not used, only 1 digit)
STATFLUKE : not used (not used, only 1 digit)
STATATOS : not used (not used, only 1 digit)
COBMOTHI : E-Cooler raw Voltage / V (value / -1.e+8)
COBMOTLO : not used
COBNUMLOOP : not used
COBSTAT : not used
ATOSCNTR : not used
COBFROMWL : not used
COBTOWL : not used
COBINCREM : not used
COBSTEPNR : not used
HEINZREGVOLT : not used
STATAGILENT : not used
  40   Thu Feb 27 20:21:31 2025 SebastianGeneral10 MHz Ref Clock (Butis)
10 MHz Referenz Clock von BUTIS mit AFG als externl clock verbunden.
Wird benötigt das die Bunch Kavität (DDS System) in Phase mit AFG (Laserreprate) ist.
  39   Thu Feb 27 16:30:57 2025 Konstantin und RodolfoDAQHF Signal
We have exchanged the HF-Signal in the DAQ Electronic: from Dummy-HF to the real HF from accelerator.
  38   Thu Feb 27 11:19:55 2025 DanyalAcceleratorpictures of the ion beam from 26.02.2025
Hier sind noch ein paar Bilder vom Ionenstrahl , wie er gestern Abend war.
  37   Thu Feb 27 10:52:32 2025 RodolfoDetectorsTaking PMTs into operation
PMT Nord the power supply (CH0) is giving an alarm already by an applied voltage of -1707 V (operation voltage is -2450 V). It is leaking to much current, larger than the set value of 310 uA. See attached picture 20250227_105411.jpg .

  • 10:50 I am trying to identify the issue.
  • 14:00 I increased the current limit Iset to 500 uA and the PMT was working OK by an applied voltage of -2500 V. After few minutes the HV power supply showed again an alarm. Afterwards the HV power supply CH0 is not giving any voltage anymore :-/
  • 14:15 We Danyal and me, tried to get the PMT working using an alternative power supply. By a voltage of -2500 V the PMT does not show any signal.
  • 16:50 I tested the HV power supply (CH0). It is working again.

Once the cave is opened, we will check this PMT in situ

PMT Mitte It is working fine by an applied voltage of -2450 V (current of 144.6 uA). See attached picture 20250227_143518.jpg. Its dark count rate is < 10 Hz by a threshold of -26 mV measured in the oscilloscope.
  36   Thu Feb 27 09:59:08 2025 KonstantinCalibrationHV-Divider
The readout of the HV divider runs on a RaspberryPi inside the HV-cave of the electron cooler.
Starting from 2025-02-27 09:42, the divider ratio was changed from 248517 to 248515. Usually, the
readout should run continuously. If not, the following procedure must be applied:

1. Connect to the Rasperry:
  ssh esr_cooler@140.181.95.195 (ask Konstantin for pwd)
2. Display logging screen:
  screen -R signals (Typically you can use arrow up)
3. Stop logging, if it is running:
  Option 1: Type "stop" and press enter.
  Option 2: control + C
4. Restart logging:
  "python main.py -i 0.1 -f loss_current -d 3 5"
5. Detach screen:
  control + a + d
6. Disconnect from Raspberry
  35   Thu Feb 27 09:38:04 2025 Konstantin & DanyalDetectorsLaufzeit Messungen
Gestern Abend haben wir die Signal Laufzeiten im gemessen:

PMT Mitte: 1213 ns (bis zur Messhütte ohne DAQ sind es 1025 ns) 
PMT Nord: 1212 ns
PD Nord: 1171 ns (ohne DAQ sind es 1172 ns) 

Weil PD Nord zu kurz war und wir es mit einem Gate&Delay nur um >40 ns Sekunden verschieben konnten, was gerade nicht reichte,
wurde entschieden dann PD Nord ein kleines delay zu geben, damit es 1240 ns sind. 
(Es gab kein passendes Kabel um anzupassen) 

Danach haben wir alle andere Laufzeiten mit Gate&Delay daran angepasst.  
PD Nord: 1240 ns 
PD Süd: 1240 ns  
PMT Nord: 1240 ns (offset war 27 ns, extra delay ist 165,88 ns) 
PMT Mitte: 1240 ns (offset war 28 ns, extra delay ist 166,2 ns)   
XUV Anode: 1008 +/- 1 ns (nur bis zu CFD in Messhütte)  Delay muss noch angepasst werden! 
  34   Wed Feb 26 18:53:52 2025 DanyalAcceleratorESR settings
Date: 26.02.2025 @  18:35

E-cooler:  HV = 157366 +/- 1 V  (HV divider value)
E-cooler current = 200 mA (scale:  1V --> 10 mA) 

Schottky f_rev = 1.782012 +/- 1 MHz (measured value) 
f_b = 1.782013 MHz (set value) 

orbit length in ESR = 108.5 m (based on experience, injection is further out, not central) 

y = 1.30796 
ß = 0.64456 


We have 1 ion bunch in the ESR
  33   Tue Feb 25 14:51:52 2025 DanyalGeneralExperiment Acceptance
Today, 25 FEB 2025 at 9:00 AM, our experiment was reviewed carefully by the safety committee. 
The experiment was accepted without problems. 
All was fine, only minor comments were made and only a few short-notice actions were required. 

The procedure has become much more complicated and lengthy over time, though. 
(Something to keep in mind.)

Many thanks to the whole team !!
  32   Tue Feb 25 13:12:01 2025 SebastianDAQTeilungsverhältnis Ohmlabs HVS250
Hochspannung Maßstabsfaktoren

-140 kV >>> 248514
-160 kV >>> 248515
  31   Thu Feb 20 13:51:04 2025 Denise, SebatianDAQDAQ Channelliste
TDC Channels
Channel # Kanalbelegung
0 Laser busy Kr
1 Next Laserstep Kr
2
3
4 PMT Mitte
5 PMT Nord
6 XUV Anode
7
8
9
10 Bunch HF (common stop)
11 Shutter auf
12 Shutter zu
13 PD NW / 89
14 PD SW / 89
15 AFG rep / 89



Scaler Channels
Channel # Kanalbelegung
16 DC Trafo
17 Injection
18 U-ecool
19 I-ecool
20 P-gun
21 P-coll
22 common stop (Bunch HF)
23 1MHz clock
24 Extraktion
25 Shutter (10kHz)
26
27
28
29
30
31
  30   Thu Feb 20 13:37:30 2025 Denise, SebastianDAQCFD Schwellen DAQ
Schwellen fuer den CFD N842 (lascool)
Lasereinstellungen dabei waren: 0.5 Skalenteile -> 115ps Pulse
3.56654MHz Reprate
Stab (3.FV) wurde auf 1.2A betrieben
mit dem PBSc wurdee eine Laserleistung von 50mW in den ESR geschickt

CFD Channel Kanalbelegung Schwelle
0PD NW 14
1 PD SW 14
2 Shutter auf 20
3 Shutter zu 20
4 AFG rep 5
  29   Thu Feb 20 00:45:00 2025 DanyalGeneralDoppler width of M1 transition
According to Paul Indelicato

transition 3P1 -> 3P0  in 78Kr32+ : 

A	2.48E+08	1/s   "transition rate" 
t	4.03E-09	s     "lifetime 3P1" 
dv	3.95E+07	Hz    "natural line width" 
dE	1.63E-07	eV    "width in eV" 

Now, if we assume a final dp/p (after electron cooling) of the ion beam of ~1E-5, 
this corresponds to a longitudinal temperature of ~16000 K (~1.4 eV). 
This implies a Doppler width of ~26 GHz (ION frame). 

This is broader than the width of the laser pulse in the ION frame (between 4.4 and 23.4 GHz). 

This, in turn, implies that we should "see" the transition if we make 0.0024 nm steps in the UV (LAB frame). 
The transition would then be something like 2-3 steps wide. 

If we use this stepsize, and scan from 257.175 nm to 257.675 nm (LAB frame), we need 207 steps. 

If one step takes 1 minute (using 1 ESR cycle and fixed laser wavelength per cycle), one scan takes ~3.5 hours ! 
I think that is too long. 

For this procedure, the ESR cycle (injection -> next injection) must be faster. 
Also the time for the laser to change the wavelength must be fast, but that should be OK. 
We should try to get to sth. like 1 hour per scan. 
  28   Mon Feb 17 13:49:20 2025 DeniseGeneralFrequenzbreiten Ionensystem
Berechnung der Frequenzbreiten des Lasers im Ionensystem 
Werte für die Frequezbreiten des Lasers aus Dissertation Benedikt Langfeld übernommen

v=0.644c 

Pulsdauer = 115ps
Frequenzbreite (FWHM) = 10.87GHz
Frequenzbreite Ionensystem = 23.36GHz

Pulsdauer = 240ps
Frequenzbreite (FWHM) = 4.19GHz
Frequenzbreite Ionensystem = 9.00GHz

Pulsdauer = 400ps
Frequenzbreite (FWHM) = 2.82GHz
Frequenzbreite Ionensystem = 6.06GHz

Pulsdauer = 735ps
Frequenzbreite (FWHM) = 2.05GHz
Frequenzbreite Ionensystem = 4.41GHz
  27   Fri Feb 14 16:41:54 2025 Sebastian GeneralVerkabelung PD ESR
Verkabelung von den Photodioden im ESR. Sind auch gelabelt.

PD gehen zuerst einmal in den FAMP (10x Verstärkung) 

PD NW -> ESR Panel 4 
PD SW -> ESR Panel 7 

XUV LED -> ESR Panel 8 
  26   Fri Feb 14 16:24:22 2025 DeniseGeneralStrahlprofil UV im ESR
Erstes Bild ist das Strahlptofil in Höhe des Nord 
towers. 
Zweites Bild (mit Millimeterpapier) und Video zeigt 
das Strahlprofils etwa in Höhe des XUV Detektors im 
ESR. Das Zittern ist dabei durch anstoßen am Nord 
Tower entstanden, wichtig hier zu sehen ist das 
„Atmen“ des Strahlprofils, welches dabei allerdings 
örtlich fest bleibt. 
  25   Thu Feb 13 12:56:01 2025 DanyalGeneralESR access - monday (whole day) 8-18 hr
  24   Thu Feb 13 12:55:13 2025 DanyalGeneralESR access - tomorrow (Fri) 10:00 - 12:00
  23   Wed Feb 12 12:48:48 2025 DanyalGeneralESR access
We had the chance to shortly enter the ESR, between 10:45 and 11:30. 

- We repositioned the PSDs of the TEM system. 
- We could see the laser beam at the ESR exit window. 
- We used a wedge at the exit window and directed the two laser beams onto a power meter and a fast photodiode. 
- We photographed the XUV detector setup. 
- We documented the cabling at the central cable panel. 

In the ESR laser lab we could see the laser beam power on the power meter and we could also see 
the laser pulses on the fast photodiode (scope). 

We still need a longer break (~2 hrs) to further optimize the setup and all the settings. 
  22   Tue Feb 11 13:08:32 2025 DanyalAcceleratorlimited access to ESR this week
Hitrap will kein ESR Zugang erlauben bevor 22 Uhr. Außerdem merken die, wenn ESR-SIS nicht laufen, dass sie morgens immer 1 Stunde Zeit verlieren weil nicht "angefordert" wurde. Deswegen wollen sie, dass ESR-SIS nachts auch weiter Strahl anfordern, etwa 1 mal pro 5 Minuten. Aber wir finden schon noch eine Lücke um reinzugehen.


Hitrap does not want to allow ESR access before 10 p.m. In addition, when ESR-SIS is not running, they notice that they always lose 1 hour of time in the morning because nothing was "requested". That's why they want ESR-SIS to continue requesting beams at night, about once every 5 minutes. But we can still find a gap to go in.
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