Hopefully we will not be opening the chamber for quite some time so find attached images of all four installed detectors and a video of them both moving into the beam axis for future reference

The left (inside ring) bellow for the motors rod was replaced.

Replacing the bellow involved;

• One person holding the metal plate the detectors are mounted on (cabling remains plugged in) while the operation is performed. 
• The motors box is supported by the cryring crane by its mounting points
• Bolts on the flange connecting to the chamber can then be undone. The whole motors section (rod included) is then moved out of the chamber using the crane and someone to stabilise the rod as it slides off the detector plate. 
• Once off the chamber, the steel cover can be removed by disconnecting from the flange and from the motors box. Best to perform on a table. 
• The bellow is then removed by removing the nuts on the small flange (kf 25) connecting the bellow to the box. The bolts for these bolts are very long and go through the motors box from the moving metal plate seen in the attached image. 
• Follow these steps in reverse to install the new bellow. 

While replacing the bellow, it was noticed the long bolts for the small flange were too short. It was therefore very difficult to re-attach the nuts with any torque. The thickness of the head of the bolts was shortend to effectively lenghten the bolt which was sufficient to tighten the nuts. New bolts should be bought in case of replacing the bellows again. 

The CARME chamber was closed and pushed back into position on the ring. 

Prior to moving back onto the ring, the detectors were bias tested and the distance between the detectors was also checked using the motors. Bias test was performed before the detector movement tests and before moving the chamber back onto the ring.  

Attached images shows the separation between the detectors when moved in togther. Separation is < 10 mm. Motors logs will be checked to place safety limits on the movement.

The chamber was pumped down. At 2 mbar the turbo was turned on, but the pressure would not decrease below 1e-2 mbar. The turbo was switched off and the pressure increased to 2 mbar. Isopropanol was sprayed on the wire seal causing an increase in the pressure. Leak on the wire seal. 

Biased detectors this morning to 150V, the leakage current for all detectors appears stable and is ~3.5 uA. We have also replaced the CAEN bias module so that all channels are now functional. Detectors are connected as follows;

CHN0 -> Top left

CHN1 -> Top Right

CHN2 -> Bottom Left

CHN3 -> Bottom Right

Reconnected the motors and moved the detectors while biased. No observable change in the leakage current during movement at 150V. An increase in the pressure of the electron target was observed during movement (up to 1e-9 mbar). This increase was only momentarily, and the pressure recovered after a couple of seconds. We expect the pressure increase from movement to decrease over time.

*Updated following FEE changes. Correct as of 31/01/24

FEE modules are labelled according to the diagram in attachment. Note attachment is looking downstream. Each FEE module is also labelled with its assigned number and whether it is a bias connection on the FEE holders. MAC addresses and FEE descriptions are as follows;

1 -  41:d8:20  - top left detector -  pn bias

2 -  41:d8:2a  - top left detector - 

3 -  41:d0:05  - top left detector - 

4 -  41:b4:0b  - top left detector -  nn bias

5 -  42:0d:0c  - top right detector -  pn bias

6 -  41:0d:16  - top rightdetector - 

7 -  41:b4:16  - top right detector - 

8 -  41:ba:2b  - top right detector -  nn bias

9 -  41:d0:0e  - bottom left detector -  nn bias

10 -  41:d8:2b  - bottom left detector - 

11 -  41:d7:cc  - bottom left detector - 

12 -  41:d7:c2  - bottom left detector -  pn bias

13 -  41:ba:22  - bottom right detector -  nn bias

14 -  41:ee:72  - bottom right detector - 

15 -  41:a0:71  - bottom right detector -

16 -  41:ee:71  - bottom right detector -  pn bias

Arrived at the control room to find we had lost connection to the power relay. We rebooted the nnrpi1 and re-connected according to the steps laid out in elog 471 -> all okay

11:00 Restarted daq with no changes to the system from yesterday. Bias consistent with previous days. All pulser peaks are slightly improved (even more for the pn pulser, one goes from 91 chn to 78). No pulser observed in nn FEE modules 9, 10, 13, 14 again.

ADC data items check OK - all ~3k

Rates - all OK  - attachment 1

1.8L spectra. - attachment 2,3

1.8W waveforms - attachment 4,5

11:20 Changed shaping time from 0xf to 0x3 (2us)

ADC data items check OK - all ~3k attachment 6

Rates - all OK  - attachment 7

1.8L pn spectra. - attachment 8

1.8W waveforms - attachment 9,10

11:35 Changed shaping time from 0x3 to 0x7 (4us)

ADC data items check OK - all ~3k attachment 11

Rates - all OK  - attachment 12

1.8L pn spectra. - attachment 13

1.8W waveforms - attachment 14,15

11:45 Changed shaping time from 0x7 to 0xb (6us)

ADC data items check OK - all ~3k - attachment 16

Rates - all OK  - attachment 17

1.8L spectra. - attachment 18,19

1.8W waveforms - attachment 20,21

11:59 Changed shaping time from 0xb to 0xd (7us)

ADC data items check OK - all ~3k - attchment 22

Rates - all OK  - attachment 23

1.8L pn spectra. - attachment 24

1.8W waveforms - attachment 25, 26

12:09 Changed shaping time back to 0xf (8us)

ADC data items check OK - all ~3k - attchment 27

Rates - all OK  - attachment 28

1.8L pn spectra. - attachment 29

1.8W waveforms - attachment 30,31

13:10 Power cycled FEE modules. nn pulser for FEEs 9,10,13,14 are now active again (no changes made in the cave) Pulser widths for nn and pn  both consistent with before lunch

To include alll 16 FEE modules in the NewMerger we edited the file /MIDAS/DB/EXPERIMENTS/MERGE/Options/carme-gsi from MERGE.LinksAvailable string 5 to MERGE.LinksAvailable string 15

We also edited the file /MIDAS/Linux/startup/NewMerger from ./master64 -i 8 -l 16 -p 11001  & to ./master64 -i 16 -l 16 -p 11001  &

We have started the Merger and tape server. The merger settings were 'corrupted' and did not display xfer Links => Merger. We implemented a fix from https://elog.ph.ed.ac.uk/DESPEC/36 and this resolved the issue.

We started the tape server, merger and go on the run control. We observe the merger working and data links to the tape server. A new file is created each time but we observe no data being written to that file. After 5 minutes of no data being written the merger crashed and the fees crashed soon after. We will leave until tomorrow to resolve.

Issue subsequently resolved see elog https://elog.ph.ed.ac.uk/CARME/487

07:10

FEE temperatures OK

System checks OK
Merger and tape server OK
Statistics look OK,
Rates in the detectors from the mointoring code indicate we have beam on target.

Detector leakge current appears to be following same pattern as yesterday -> temperature (attachment 1)

Merger stats (attachment 2) - quite a few more pause / resume statements than normal - noise last night?

Target density appears stable over the last 3 hours ~3.8e11 at/cm2, ring pressure stable YR09 ~1.5e-10 mbar

Beam injection looks stable over the last few hours.

09:08

FEE temperatures OK -aida03 and aida09 0.5 C over 65C warning.

system checks OK

ADC data item stats  OK

Spectrum browser rate (attachment 3)

Merger and Tape server OK

Monitoring  xy and energy histograms since zero'd last night (attachments 4+5)

Target density slight drop to ~3.5e11 at/cm2. Pressure in the ring stable. CB attempting to optimise target density and ring pressure.

Beam injection into the ring still good

11:04

FEE temperatures OK

System checks OK

ADC data items and spectrum browser rates OK

Target density ~4.6e11 at/cm2, ring pressure looks OK ~1e-10 mbar

Beam injection still good.

Merger and tape server OK

12:45

Beam injection over last 2 hours has been stable

Target density 4.75e11 and stable. ring pressures are stable.

FEE temperatures OK

System checks OK

ADC data items stats and spectrum browser rates look OK

Merger and tape server OK

14:01

We wish to test the beam ahlo on injection so are ending run

Run stopped.

14:01

Run 36 started.

We put both detectors to the fully out position. Detectors then driven IN using the pnuematic motor only once the beam is ready and driven fully out before beam dumping.

We notice the right arm is significantly slower than the left arm and does not manage to go fully out before being told to go back in. This is not ideal.

Run stopped.

14:10

Run 37 started

Right arm is positioned at pot = 70.49 and remains stationary. The left arm is moved with the ring cycle. When IN left arm pot = 62.71 mm. When out left arm pot = 18.89 mm

Movement signals are being saved to jan MBS system and can be used to seperate out injection periods on other runs where both detectors will be stationary.

All beam and target settings are the same as for Run 35.

Spectrum browser rates for each FEE when left arm IN shown in (attachment 1). Rates dependent on beam cycle, when detectors move out, rates in left arm drop significantly as expected.

XY and energy histogram plots from monitoring code (attachments 2+3)

We see the Rutherford much more well defined on the bottom left detector now (it is further in and halo effect is reduced). Still some low energy counts (may be due to detector movement -> need to test without beam)

Top left detector energy histogram looks a lot different, still much halo effect.

we will collect some stats for 30 mins or so

14:57

Run 37 Stopped. Run 38 started.

Faraday cup to the ring closed. No beam in the ring. Left arm of the detectors still moving IN and out of the beam with the ring cycle.

Very little counts observed in energy spectra.

15:02

Run 38 stopped so Gleb can change the beam energy. Run 39 started.

09:00

R4 alpha background continues, currently R4_12

Temps OK, system checks unchanged from previous status (OK, aida16 clock and ADC issue)

10:30

R4 stopped and moved to the next run R5.

Lithium 3+ beam is not feasible at sufficient densities so we are switching to D+ at a beam energy of 0.75 MeV/u. A measurement of d+p at this energy would produce 3He at energies of ~900 keV. 

The current threshold (slow comparator) has been 1 MeV (0x64). We lowered the thresholds in all FEE modules to 200 keV (0x14). ADC rates look fine in all FEEs (~tens of Hz) except in aida 15 and aida 16 which was ~several hundred kHz. Data rate to disk was 1.2 Mb/s

We increased the threshold in aida 15 and 16 only to 500 keV (0x32) and rates in aida 15 and 16 have dropped to <20 kHz. Data rate to disk now 220 kB/s.

11:00

R5 stopped. R6 started - background with reduced thresholds. 

Attachment 1 - ADC data items statistics

Attachment 2 - Histogram browser statistics

Attachment 3 - Tape server

Attachment 4 - New Merger

13:12

R6 continues R6_9

Edits to the CARME sort code have been made. EyEx energy cut for online monitoring reduced to 100 keV. Multiplicity cut applies to lowEnergyEy, lowEnergyEx and lowEnergyXY histograms. Multiplicity cut considers only single strip events.

15:00

D+ beam is now in the ring and is being optimised by the beam operators. The CARME detectors are currently fullt out, but we can see some effects of the beam on the online monitoring code.

14:00

Access to the cave as Nikos and Andreas have begun work on the target.

Run 36 started - pulser walkthrough.

Pulser amplitudes of 8, 7, 6, 5, 4, 3, 2, 1

Attachment 1 - pn channels

Attachment 2 - nn channels

Attachment 3 - pn channels (zoom)

Attachment 4 - nn channels (zoom)

Best pn channel looks like AIDA09 - pulser width 63

Worst pn channel looks like AIDA14 - pulser width 148

Best nn channel looks like AIDA12 - pulser width 58

Worst nn channel looks like AIDA16 - pulser width 246

This is approximately the same as pulser widths before the beam time.

09:30

New run 54 with:

Electron cooler setpoint 244.1 V

Electron cooler read 243.55 V

Collector current 4.3 uA

Right arm at 64.60 mm

Left arm IN at 36.54 mm

MBS working - hopefully

Target 7E11

Injection ca. 5E7

horizontal beam position changed to 8.75 mm

vertical beam position still -5mm

10:30

No beam

ADC stats increased to 250k again same time as beam lost

Detector shake resolved problem

System checks OK

10:35

Beam back

12:17

All system checks OK

12:29

DSSD top left noisy again. Detector shake resolves issuie

14:02

Running smoothly. Temps OK. Stats OK, but write to disk rate x10 usual for unclear reasons.

Target mostly stable. Beam OK, missing some injections occasionally.

14:25

Detector 0 noisy. Shook. Fixed it.

Target density this morning had stabalised at 7e11 at/cm2

This is sufficient to test the beam/target overlap using the lifetime of the beam in the ring.

Previous attempt at this method was done at 1.5e11 at/cm2 where lifetime from residual gas and target are essentially the same.

Beam set to bunched. Beam position varied by 1mm and the number of particles in the ring taken from Grafana plots. Particles at injection compared with at dump.

Significantly more beam loss at > 8 mm beam position with highest value at 8.75 mm. This is the maximum we can move the beam.

Test repeated with no target. Same beam loss rate for all positions. We see a clear difference with the target only at positions > 8mm.

Test repeated with original electron cooler voltage Gleb tuned with last night. Same outcome -> cooler voltage has no significant impact on overlap (for 0.1V at least)

Overlap using count rate over 7.5 minutes also tested. DSSD 1 (top right) used as gauge as no beam stripe is seen in this detector. 

At horizontal position 4 mm (previous estimation of overlap) we saw a small increase in counts around 4.7 MeV with the target off compared to target on (76 vs 57)

At horizontal position 8.75 mm we saw a large decrease in counts around 4.7 MeV with target off compared to target on (95 vs 290)

It appears clear the overlap is at 8.75 mm. Future runs will use this as horizontal beam position.

10:00

The computer screen controlling the DAQ on carme-gsi appeared to have crashed.

Unable to move throught the different windows etc.

Unable to connect via anydesk. ssh access still available. It appears the x-server had crashed, we noticed earlier in the beam certain functions such as screenshots were glitchy so this was probably expected eventually.

We were able to access the DAQ on another CRYRING machine machine via 192.168.207.143:8015 and 192.168.207.143:8015 in the browser. DAQ is still running. We will try to reboot the x server without disturbing the DAQ.

ssh into carme-gsi and used the command 'systemctl reboot gdml' to attempt to reboot only this server.

This did not have the desired effect, whole of carme-gsi rebooted. We should have turned off the FEEs and stopped the DAQ gracefully but did not.

Restarted carme-gsi and rebooted the FEEs and DAQ system.

All checks OK -> clocks, ADC calibration etc.

ASIC settings loaded are 2025APR08. Only changes made to this settings were reducing the slow comparator threshold from 0x32 (1 MeV) to 0x14 (200 keV). aida03 and aida04 were set to the MEC on these settings, they have now been reset to the LEC channel (0x0). All channels on the LEC.

Pulser walkthrough conducted while the cave was open.

Pulser amplitudes 90000, 80000, 70000, 60000, 50000, 40000, 30000, 20000, 10000

DSSD4 was set to MEC and bias off as the detector had previously tripped.

All thresholds set to 0x64 for the pulser walkthrough

18:05 We believe we have an overlap between the beam and the target. Run 22 started.

          CARME detectors in with the servo ONLY. Left arm pot 36.5 mm, right arm pot 37.7 mm

          Target density apporx 2e11 atoms/cm2.

          Shots into the rin partially stable (sometimes consecutive injections at high intensity, sometime apporx 1 in 4 fail rate).

          We plan beam run overnight, remote shifters will check on the progress every 2 hours.

18:32

Everything ok. Temperatures and leakage current are okay.

Attachment 1: Rates

Attachment 2: Temperatures

Attachment 3: Waveforms layout 7

Attachment 4: Waveforms layout 8

Attachment 5: Waveforms layout 1

Attachment 6: Waveforms layout 2

Attachment 7: Leakage current

Attachment 8: xy plot for all four detectors.

21:00 Checks made, everything okay!

23:00 Checks made, everything okay!

Attachment 9: Rates

Attachment 10: Temperatures

Attachment 11: Waveforms layout 1

Attachment 12: Waveforms layout 2

Attachment 13: Waveforms layout 7

Attachment 14: Waveforms layout 8

Attachment 15: Leakage current

14.02.2023 01:00

Checks made, everything okay!

Attachment 16: Waveforms layout 1

Attachment 17: Waveforms layout 2

Attachment 18: Waveforms layout 7

Attachment 19: Waveforms layout 8

Attachment 20: Rates

Attachment 21: Temperatures

Attachment 22: Leakage current

02:27

FEE temperatures OK

System checks OK

ADC data items appears ok for all FEEs, except aoda09 shows rates of ~1kHz. Spectrum borwser shows this is from a single strip. Checl load aida09 several times but no change to the rate.

Leakage current appears fine. (Attachment 23)

Merger and tape server OK

Ring pressure appeared to have dropped and the target density had dropped to approx 5e10 at/cm2 range. Target nozzle moved 200 steps. Density back to 2.5e11 range and pressure is high -11 low -10 mbar range. <----- Operator mistake

XY plot all detector (attachment 24)

EyTotal all detectors (attachment 25)

05:08

Target density appears to have been very stable over the last few hours ~2e11 at/cm2. Ring pressure also appears stable.

FEE temperatures OK

System checks OK

ADC data items appears ok for all FEEs,Aida09 rate appears to be reduced again.

Leakage current appears fine.

Spectrum browser rates (attachment 26)

Spectrum browser stats (attachment 27)

Spectrum browser 1.8*L pn (attachment 28)

Spectrum browser 1.8*L nn (attachment 29)

New merger stats (attachment 30)

I am not confident we are seeing significant Rutherford scattering accumalated so far.

07:18

FEE temperatures OK

System checks OK

Stats OK

Leakage current appears fine.

Spectrum browser rates OK

Spectrum browser stats OK

Spectrum browser 1.8*L OK

Spectrum browser 1.8*L nn OK

New merger stats OK

7:40

Noticed operator mistake at 3 am. Ring pressure was very bad in YR08. Unlikely we had much beam since then. Moved nozzle to improve pressure.

See attach 38 & 39.

08:51

Checks all ok. Temperatures and leakage current ok. Merger ok. 

Attatchment 40: Rates

Attatchment 41: Temperatures

Attatchment 42: Waveforms layout 7

Attatchment 43: Waveforms layout 8

Attahcment 44: Waveforms layout 1

Attatchment 45: Waveforms layout 2

Attatchment 46: Leakage current

Attatchment 47: Gasjet board - not much change from last check

Attatchment 48: Vacuum pressures 

Beam energy - 1.361 MeV/u

17:12

Run 28 Started - beam on target

Detectors IN (left arm pot = 36.5 mm, right arm pot = 70.5 mm)

Beam position (vertical offset -9mm, horizontal offset -7.5mm)

Ions circulate in the ring for 3 seconds before they are dumped. Total time between injections is 12 seconds.

Target density apporx 4.2e11 atoms/cm2, pressures in the ring are below 1e-10 mbar. (Attachment 1+2)

Leakage current plot (attachment 3) - change in leakage current is consistent with temperature variation from ML online plot.

18:18

FEE temperatures OK - aida09 is slightly hot - 65.06 C so slightly above vertex temp value of 65C and stays this way over several reloads (attachment 4)

System wide checks OK

Statistics (attachments 5+6) - aida09 and aida12 slightly high stats but still <1K. Check load does not resolve.

Tape server OK - writing ~730 kB/sec

Merger OK

Monitoring code XY plots and Ey energy histograms (attachments 7+8)

18:53 All checks OK

21:58

All system checks ok. Temperatures and leakage current ok. Merger ok.

Attatchment 9: Rates and stats - all below 1k

Attatchment 10: Temperatures

Attatchment 11-14: Waveforms layouts 1,2,7,8 respectively look okay

Attatchment 15: Leakge current

Attatchment 16: lowenergyXY plots

Vacuum pressure is ok.

23:01

system wide checks ok. Temperatures ok. Leakage current ok. Merger ok all went green. Waveforms same as 10pm check.

Statistics - aida09 and aida12 went over 1k (attach 17), but reloaded and settled down again seconds appart (attatch 18). Reloaded again at 23:14 and stats were aove 1k again (attatch 19).

Attatchment 20 is the leakage current, still ok. 

Vacuum pressure ok (attatchment 21) - rises after small bump down from the regular value.

01:00

System wide checks ok. Temperatures ok. Leakage current ok (see attatchment 22). Merger ok all went green. Waveforms the same as 10pm check.

Statistics - aida09 and aida12 occasionally just over 1k when reloading a few times, but goes below mostly.

Vacuum pressure ok, stablised after small bump around 10ish (attatchment 23)

03:00

Ring vacuum suffered from long-term creep, especially in YR08. Tweaked nozzle position. Pressure improves, target density slightly affected. Attachment 24-25

Leakage current and temperature indicate we have an increase in temperature in the ring. This is confirmed by vacplot. Attachment 26-27

Merger continues OK 28

Rates and Stats show we have no beam. Going to the lab 29-30.

R28_22 NO BEAM

03:45

No beam in the ring, we are missing all the spills. Called HKR.

Detectors out in case beam manipulation is required.

Stat plot looked OK. 31

04:35

DAQ continues OK on run R28_24, still no beam

Temperatures slightly lower - OK

System wide checks - OK

Stats - OK

Merger - OK

05:44

Beam is back. It had been away since 1:30 am due to a fault in the new EC power supply. Fault reason unclear.

Detectors back in (left 36.54, right 70.49 mm)

R28_26 BEAM ON

(Beam likely off from R28_ 21-25 inclusive)

Temps as before

Stats now OK - att 32

Merger OK - att 33, 34

Stat spectra OK - att 35. Note slope in ASICS (Rutherford?)

Leakage current trending up - likely temperature related.

Ring pressure OK

Gas target 4.14E11

Beam at injection around 7.5E6. Could be higher. Asked for optimisation later today assuming current configuration holds.

06:59

Temperatures OK

System checks OK

Stats looking good in all FEEs except aida01 and aida15

Leakage current has levelled off - looks OK

Ring pressure looks OK and is trending down - target density 4.1e11

Merger and tape server OK

08:30

System checks all OK

Temperatures OK

Merger / tape server OK - data being written R28_29

Target density 4.1e11, ring pressure stable

09:00

Attachment 38 Spectrum browser stats for all FEEs (log scale)

Attachment 39-42 Spectrum browser *L histograms for select channels for each detector. MIDAS data is consistent with inline monitoring plots.

System checks OK

Beam still on - target density and ring pressure remain stable

11:28 We have access to the voltage dividers for the electron cooler. The voltage is -763.625 V. This corresponds to an electron energy of 746.795 eV and a beam energy of 1.361 MeV/u  using ML ion calc.

This is above the resonance energy of 1.3435 MeV/u. We will now end the run and set the cooler voltage to this ion energy.

Run ended. Run 29 started while setting beam energy.

21:32

New run 59

Right arm at 64.60 mm

Left arm IN at 36.54 mm

MBS working - hopefully

Target 4.7E11

Injection ca. 4E7

horizontal beam position 8.75 mm

vertical beam position  -5mm

Changed electron cooler set point to 244.85 V

Read value 244.3 V

Collector current 4.31A

Histograms and statistics zero'd. Code reset

Rates OK. Temps OK.

22:44

Screenshots of the above

23:00

Detector 0 shows usual strong noise. Shook twice. Fixed it. Beam loss in correspondence with this event.

Beam mostly recovered a few minutes later.

23:28

Detector 0 shows noise. Shook twice with servo. No result. Shook with pneumatic. Fixed. Some beam instabilities again.

01:00

Temps OK. Rates OK.

Merger OK. Write to disk OK (file 59_13)

01:36

Detector 0 shows usual strong noise. Shook it. Fixed it.

01:46

Detector 0 shows noise. Shook twice with servo. No result. Shook with pneumatic. Fixed.

The noise increase is definitely correlated with spikes in YRT1DT1MK current reading. Unclear what the reading is.

02:36

Target density has been consistentyl above 1E12 recently, very unstable and trending forward. Increased Lakeshore setpoint by 0.5 K.

Density decreases to high 1E11, and appear significantly more stable. E1 pressure reading also decreasing to 1E-1 mbar.

Temps OK. Stats OK. Merger OK. Write to disk OK.

03:58

Temps OK. Stats OK. Merger OK. Write to disk OK.

Target still unstable and now a bit too low density. Trying to slowly lower the temperature in 0.1 K steps.

04:55

Temps OK. Stats OK. Merger OK. Write to disk OK.

Target around 6E11 atoms/cm2, with Lakeshore temperature at 30.8 K. Waiting for it to stabilise.

05:34

Detector 0 noisy. Shook. Fixed it.

Realised I had not moved the detector back at 01:46 after shaking it. Most of this run has been taken with detector 0 fully out, i.e. 18.86 mm.

Moving in and moving to a new run.

14:05

Run 22 stopped. Run 23 started we will now adjust the vertical beam position to see if we observe the beam stripe seen in the last beamtime.

Current vertical beam position 0.0 mm. Horizontal beam position 7.0 mm. Coasting beam.

Beam D+, 1.5 MeV. Storage time ~ 20 minutes. Target ON. Density ~1e11 at/cm2.

XY plot from run 22 with the same settings - attachment 1

Beam stripe looks like it is just on bottom detectors (just )

14:10

New beam settings

Vertical Beam position 5.0mm, Horizontal unchanged. Storage time reduced to ~2 minute

No real change observed. Perhaps some thing more can be seen on top right detector but definitely not like in the Feb experiment.

14:15

New beam settings

Vertical Beam position 9.0mm, Horizontal unchanged.

No real change observed again.

14:20

New beam settings

Vertical Beam position -9.0mm, Horizontal unchanged.

More events observed on bottom left detector but nothing like the Feb measurements. I think we do not have stripe effects like previously.

14:40:50

New Beam settings to check beam lifetime.

Vertical beam position set back to 0.0 mm. Horizontal unchanged

In bunched mode to observed intensity over time. 

Injection into ring 2.2e7

15:15

Beam intensity dropped to 1.1e7. Beam lifetime 35 minutes.

Merger OK, Tape server OK

ADC data item statistics looks as before. OK

FEE temperatures look OK

System checks OK

Leakage current stable

15:24

We removed the target. Beam intensity at 2.2E7

After 35 minutes, the beam intensity is 1.41e7. So target does have effect on beam lifetime! We would like more.

16:05

We will now bring target back in and try to increase density.

16:10

Some sort of GSI-wide failure, we have lost beam entirely. We don't see any effect on our system. Temperatures and leakage currents are stable

Detectors moved fully out for safety

17:15

Merger OK, Tape server OK

ADC data item statistics looks as before. OK

FEE temperatures look OK

System checks OK

Leakage current stable

19:15

Still no beam

Merger OK, Tape server OK

ADC data item statistics looks as before. OK

FEE temperatures look OK

System checks OK

Leakage current stable

21:15

Still no beam

Merger OK, Tape server OK

ADC data item statistics looks as before. OK

FEE temperatures look OK

System checks OK

Leakage current stable

21:40

Beam has returned!

22:00

Target at around 9e11 and appears stable

Merger OK, Tape server OK

ADC data item statistics looks as before. OK

FEE temperatures look OK

System checks OK

Leakage current stable

22:33

Beam back in the ring. Beam settings to be updated.

Rates in right hand detectors look slightly different to before - lower in bottom right, slightly higher in top left. Perhaps beam vertical position needs to be lowered slightly.

ASIC check load just to be sure. Rates in aida15 greatly reduced - only temporarily.