ELOG E0052

scraper info by Robert Boywitt

attched is more info about the T-scrapers (E-cooler) by Robert Boywitt (Tel: 2067 or 3357)

Thu Jun 13 10:42:02 2024

Danyal

General

Question

What is the ion beam lifetime, according to the DCCT and Schottky? 
Can somebody measure it, please? 
Yesterday we could not see a fast drop in the "main" beam. 

Because the lifetime that is mentioned here is the one based on the particle detector and on the PMT countrate. 
If what is seen now is "only" some fast decaying component inside the beam, we could simply wait for its decay and then continue with the real measurement.

Thu Jun 13 10:06:35 2024

Constantine, Peter, Lukas, Jonas, Dounia, Carsten

Suspected Beam Troubles (is it really 229-Thorium?)

From experience, the lifetime of the beam in the storage ring should be on the order of magnitude of hours, however, we observer beam lifetimes of the order of 10ish minutes. This suggests either a beam loss mechanism, a totally wrong species or a combination of both.

Yesterday (Elog entry 46) it was verified that the main beam is indeed 229-Thorium in the ESR.

2024-06-13: After discussion (phone) with Markus the lifetimes are reasonable and are dominated by recombination in the cooler.

Mon Jun 10 08:57:35 2024

Carsten/Konstantin

Further Tests from Sunday 2024-06-09 - new voltages and tresholds for PMTs - testdata in files

Voltages and thresholds increased for PMT Middle and North (in order to account for the ADC measurement in DAQ2

PMT South ("braodband") ET9422	1500 V	thresh: 7
PMT Middle ("smallband") ET9423	2650 V	thresh: 10
PMT North ("smallband") ET9423	2650 V	thresh: 12

Tests with laser

Thresholds adjusted for PD SO and PD NO.
Smaller adjustements in the analysis cdoe of DAQ1 (directory 229Th) to deal with the proper alignment of laser steps (Step-spectra). Seems to solved now.

DAQ rate/trigger rate DAQ1 - interference with Labview
DAQ1 can be started without connection to Labview server after some timeout (~ 1min) or so the usual trigger rtate of 200 Hz can be seen in mbs (via: "sh acq" command)
If the Labview server is closed, e.g. during the run or between to laser runs - the DAQ rate drops to 30 Hz only. Very likely MBS is busy trying to fetch data from the non existing Labiew server.
The problem can be solved by leaving closing the the DAQ (MBS not Go4...) and restarting mbs/DAQ, e.g. via @shutdown, leave mbs, resl, start mbs, Qstartup, start acq.
Of course, also Go4 needs to be restarted to establish a new connection to MBS.
The DAQ rate of DAQ1 should be regularly checked with sh acq !

Test data
DAQ1: 005.lmd
DAQ2: 010.lmd
both rubbish, partially adjustments of threshilds etc.

~2.7e6 ions (238U92+)
201 laser steps 550nm, 549nm, 50 shots per step
DAQ1: 006.lmd
DAQ2: 011.lmd/012.lmd
Threshold for PD SO not adjusted

restart
DAQ1: 007.lmd
DAQ2 013-017.lmd

same with few 10^5 ions:
DAQ1: 008.lmd
DAQ2: 018-020.lmd

Sun Jun 9 10:08:24 2024

Carsten/Danyal

Particle detectors - Recap of yesterdays work

South (behind cooler) - "SA_SZ" - DD2...
We have put the particle detecotr North to the poistion behind the cooler (north) to replace the defective particle detector.
This detector is an old "Kozhuharov" style plastic szintillator that runs with a voltage of 1400-1500 V.
The signal line in the Messhütte / ESR is the #5 (normally we have #6).

North (behind target) - "NA_SZ" - ....
In the north we put one of my "spare" detectors that I assembled from "old" parts of not well known provenience (old plastic, old small 1 inch PMT). While machining the plastic szintillation material it seems that the mateerial got slightly to warm and shows micro cracks. Still the detecotr works without any issues and with good timing.
Please note that typical voltages here are ~600-700V.
The signal line in the Messhütte is the #5 (north outside)

Sun Jun 9 10:20:38 2024

Carsten/Danyal

Recap from yesterdays work with test beam (Detectors / beam /DAQ)

In the ESR we had thw whole day (saturday) a 400MeV/u bunched 238U92+ test beam (about 2 MHz). The RF signal is cabled as input to the DAQ (seperate post/entry).
Intensity is artificially reduced to a few 10^6 (with some tests alsodone at 10^5).
In all the tests the both particle detectors were moved in pus the empty pocket on the inside to mimick the background conditions during the run (aka no other isoopes, no other charge state, clearing of orbit fromdonw-charged ions.

Noise background
With the bunched beam all three PMTs and the channeltron show an ~20MHz "noise beat" below the actual signal that seems to be phase stable. The "noise train" is repeated with about 2 MHz (very likely the bunch revolution frequency). The amplitude of the noise is rather low and can be easily discriminated for the three PMTs, but not so easy for the channeltron, as the channeltron signal is more "continuous" and has no clear gap for the threshold.
A working hypothesis could be that Al mirrors or something similar act as pickup electrodes for the real beam.
2024-06-10: Correction : Signal is not "phase-stable" - and 200 kHz (wrong reading and triggering of scope)

Channeltron
The signal of the CT is rather small. In order to get the singal of the CT out of the noise it needed to be opreated at about 2600V. With an according threshold setting the CT sees a signal that is clearly from the beam and absent with "no-beam". The signal is 6-7 kHz even at the lowest intensitiies of ~10^5 ions in the ring. Worse, it doesn't show any bunch timing peak in the spctrum.
We decided that under these conditions the CT cannot be used during the 229Th beamtime.

PMTs
Voltages of the PMTs and thresholds of the CAEN CFD are adjusted with a bunched beam with an intensity of few 1 to 3*10^6 ions (and thus should be ok for lower intensities):

PMT South ("braodband") ET9422	1500 V	thresh: 7
PMT Middle ("smallband") ET9423	2550 V	thresh: 9
PMT North ("smallband") ET9423	2600 V	thresh: 11

Bunch signals in DAQ

Ion frequency (measured) used in DAQ1 in SetParameter.C: 1.9693 MHz, the divisiion factor is set to 88.

All three PMTs show very nice and small bunch-time signals with a very low background floor. Thresholds are adjusted to have at least "1CFD tick" extra margin.
The small-band PMTs have no-beam rates < 1Hz, PMT south < 10 Hz.

The clear visibility of the bunches on the small-band PMTs means, on the other hand, that we still have quite some background from collisions with the residual gas (albeit it seems to be lower that in the last beamtime, but no concrete (normalized) numbers are available. PMT North and Middle have about the same solid angle but PMT middle features the CaF2 window. The bunch singal rate of PMT middle is about twice the one of PMT north indicating that about half of the signal stems from hydrogen Ly-alpha (at 121.6 nm) that is cut-off by the CaF2-window (about 123 nm).

We should discuss a) if the vacuum can be further improved, e.g. using the turbo pump, b) if PMT north should get a CaF2 filter (not at the moment).

All these findings are for the 400 MeV/u 238U92+ beam and should be rechecked with decelerated 200 MeV/u beam.

For both DAQs data are accumulated with two data sets, the first at a a few 10^6 ions and the second at a few 10^5 ions:
files for run1 (mid int): 003.lmd (DAQ1), 006-006.lmd (DAQ2)
files for run2 (low int): xxx.lmd (DAQ1), yyy-yyy.lmd (DAQ2)

The timing signals can also be very nicely be seen in the 25 ps TDC of DAQ2.
DAQ2 records also th common Stop signal in the 25ps TDC. There are indications that the CS signal (derived from the bunch frequency) jitters. The discrimonation of the bunchsignal should be cheked.
In DAQ2 the thesholds and windows for Mesytec are not yet set properly, so thre is no ADC signal, and no "second" discriminated signal.
This is because the Mesytec MSFC16 module had to replaced by a different similar module but with non-ideal internal components. The module still needs ot be adjusted properly.

Wed Jun 5 19:22:43 2024

Carsten, Konstantin, Rodolfo

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.

Fri Jun 14 11:44:23 2024

Carsten Brandau

Cooling Time in SC7 increased from 9s to 12s

Cooling Time in SC7 increased from 9s to 12s

Tue Jun 11 23:46:06 2024

Carsten ))))

----
The frequency of the primary beam 238U82+ at the injection:
Ucool = -360 V
Frev = 1.974647 MHz without bump
Frev=1.97387 MHz with bump
---
ID:
246 MHz + kHz (+/- intensity) ID
521 +++ 238/92+
565 +.    230/89+
595 +++ 235/91+
642 +.    227/88+
670 +.    232/90+ 
693 +++ 237/92+ (strongest line)
721 +.      224/87+
744 ++.   229/89+ (our Th line)
767 ++.   234/91+
822 +.     226/88+
845 +.     231/90+
867 +.     236/92+
901 -       223/87+
922 +.     228/89+
942 +.     233/91+
1001 +.    225/88+    
1020 ++.  230/90+
1039 +.    235/92+ 
1100 +.     227/89+
1211 + <- far off

Fri May 31 16:49:52 2024

Wiring DAQ 1

Started to Check the wiring.

Status as of 2024-05-31

Inputs into 1. DAQ /TDC/Scaler - List according to file TLdaInputDescription.h in directory ~/go4/229Th

Cobra_Busy, // 0:
Next_Laserstep, // 1:
Laserscan_Complete, //2 :
{"PMT_South", 3, {3,11}},
{"PMT_Middle", 4, {4,11}},
{"PMT_North", 5, {5,11}},
{"Empty0", 6, {}},
{"ParDet_South", 7, {}},
{"ParDet_North", 8, {}},
{"QSwitch_500us", 9, {}}, // Important to mitigate missing Q-Switch
{"EmptyA", 10, {}},
{"Channeltron", 11, {9}}, //not yet wired
{"Bunch HF", 12, {}}, //not yet wired
{"PD_NorthEast", 13, {}},
{"PD_SouthEast", 14, {}},
QSwitch, //15
DC_Trafo, //16
{"Injection", 17, {}},
U_ECooler, // 18
I_ECooler, // 19
{"P_Gun", 20, {}},
{"P_Coll", 21, {}},
{"Common_Stop", 22, {}}, //? P_coll two times????
Clock_1MHz, // 23
{"Empty1", 24, {}},
{"Empty2", 25, {}},
{"Empty3", 26, {}},
{"Empty4", 27, {}},
{"Empty5", 28, {}},
{"Empty6", 29, {}},
{"Empty7", 30, {}},
{"Empty8", 31, {}},

Checked also the connections from the CFD to DAQ 1 (ok)
input connections to CFD are as labelled on the black laser Messhütte panel

CFD channels:

0: PMT south
1: PMT niddle
2: PMT north
3: PMT copper (not used)
4: PD NO
5: PD SO
6: Part Det South
7: Part Det North
8: empty
9: XUV front (not used)
10: XUV back (not used)
11:
12: Master Osci Bunchng HF (Süd)
13: empty
14: empty
15: Master Osci Bunchng HF (Nord)

PD_NO and PD_SO are terminated with 50 Ohm at input (conflicts with 50 Ohm input termination of CFD)

Sat Jun 1 18:00:20 2024

ReadOut Trigger im Timer Scaler changed because of faulty signal from frequency generator

Old readout trigger (~200 Hz) in 1MHz Scaler showed two nearby peaks indicating a jitter of the readout frequency or same faulty output driver of the frequency generator Metrix GX240 used to produce the readout frequency (see below).

Used the 1 kHz clok instead divided by 5 -> only a single peak in 1MHz spectrum in the scaler (see below).

This should be used during the beamtime.

Sat Jun 1 18:14:01 2024

DAQ and analysis directories

Analysis

DAQ1 (original):
-user atplaser
-runs on lxg1297
-go4 in ~/go4/229Th
-mbs in /esr/usr/atplaser/mbsrun/E0052/DAQ1
-data in lxg1297:/data.local2/229Th/
filenames follow the style 229ThDAQ1_nnnn.lmd (where nnnn is 4 digit integer number)
Data backup on WDBook lxg0155 local:
/media/stoe_exp/WDBook/E0052daq1 (/dev/sdc2)

Since the Go4 Code is still under development (clean up etc.), I still plan to submit regular updates, the last version before is always in ~go4/229Th
It is planned that all essential settings can be done via the automatically loaded script files SetParamters.C and SetConditions.C, so that no recompilation (and change of code) is required (work in progress).
Values in SetParamters.C and SetConditions.C have to be adjusted to the actual run.

DAQ2 (new / enhanced):
additional 25ps TDC, ADC and Vulom Scaler
-user stoe_exp
-runs on lxg0155
-go4 in ~/E0052/go4
-mbs in /esr/usr/atplaser/mbsrun/E0052/DAQ2
-data in lxg0155:/data.lcoal2/E0052/
filenames follow the style ThDAQ2_nnnn.lmd (where nnnn is 4 digit integer number)
Data backup on WDBook lxg1297 local:
/media/stoe_exp/WDBook/E0052daq2 (/dev/sdd2)

The following .scom in the directories will help to run the experiment
@startup in mbs -> Generic startup of all mbs tasks for data acquisition
@shutdown in mbs -> Ceans up everything before leaving mbs
@connectdisk -> connects to the rfio server on the data local disks.
or this, rawDispRFIO64, has to be started (locally __IN__ the data directory).
@openfile -> automatically opens a new file in the data local disks
@closefile -> closes the file
@disconndisk -> disconnects from the rfio server

Please note that the different path and file names are on purpose, so that they can be distinguished after the run.

Sat Jun 1 18:55:18 2024

Go4 Analysis Version for DAQ1 (atplaser)

Analysis

Small enhancements and minor corrections / bug fixes are made to the original version of the online GO$ for DAQ1.
Assignment of channel names corrected, condition names adapted to present DAQ
Potential pitfalls are commented in the code.
The old version is untouched in its old directory.

The new version is in directory ~/go4/229Th. This version should be used for DAQ1 !

Some minor changes will still be needed to be done.
Please comment changes in the code with date and name and write into Elog.

Sat Jun 1 19:00:57 2024

Change of (offline) frequency for common stop (CS) of VUPROMs (and 2nd TDC) and scaling factor

Temporarily, for tests of the second DAQ I changed the frequency from the frequency generator and scaling factor that is used for the common stop signal to a value that is close to the expected value in the experiment.
Reason: For the second TDC (CAEN 25ps) TDC the time between to CS events must be of the order of 45 us. The TDC can store events up to about 51,x us and allows for overlap of these regions to be able to stitch together the events to a continuous time axis.

Since we plan to run at ~ beta= 0.5566 the revolution frequency is about

f=1.540974 MHz (0.6489 us)
This value is used in the frequency generator.

The scaling factor is set to 68.
=> 68 x 0,6489us = 44,1252 us between to CS.

Of course later the real RF value from the accelerator will be used.

Please leave or, if required to change, mark in ELog.

Sat Jun 1 19:19:07 2024

Reminder: Check signals in scope and in DAQ of detectors with voltages switched off (vs. CFD threshold)

When the ion pumps and vacuum gauges are switched off the scaler data of 
PMT_south, PMT_middle, PMT_north, PD_NO, PD_SO, PartDet North, PartDet South and (Channeltron) should be checked without voltages applied in dependence on the CFD thresholds to determine the "cable noise level" at which thre are NO entries other than 0 in hte spectra (minimum background).

Same for 2nd DAQ and Mesytec MSCF16

Sun Jun 2 00:01:46 2024

25ps TDC CAEN V1290N DAQ2 lead to crash in DAQ2 due to a hardware issue

On the CAEN V1290N TDC the piggy board for the lower 8 channels is not fixed well to the motherboard.
That prevented to the whole DAQ2 to trigger correctly or even crash every once in a while. Long attempt sot find the error in hard and in software.

I fixed/reattached the piggy board, but be careful with the attached Lemo cables. They might loose the board again (it used to fixed with hot glue).

DAQ2 now also seem to run smoothly.

Wed Jun 5 14:17:36 2024

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

Thu Jun 6 09:39:23 2024

Preliminary Channel Table (DAQ1 and DAQ2)

Thu Jun 6 19:42:20 2024

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 19:47:01 2024