Run 23 Stopped due to some unexpected spikes in the

voltage of collimator.

The plunger did not responde to change distance.

The chamber was opened and observed some yellow spots

seen over the Cd target.

Run 24 has been started but no beams at the moment.

EAGLE is opened.

Just colecting background.

Using  the data which we've sorted to date, I looked into the gamma-gamma coincidences and have identified a number of nuclei e.g. 50Cr, 52Mn, 55Fe which would be consistent with fusion-evaporation reactions involving the sulphur-32 projectiles and aluminium-27. Such reactions would yield a 59Cu comound system and these channels would be populated as a result of the evaporation of a combination of alphas, protons and neutrons.

These lines are intense and the conicdences are very clear and clean. I think this suggests that the beam is hitting some aluminium components within the plunger chamber. This could be the plunger vessel itself or the target frame perhaps.

There is another interesting observation: some of the identified transitions are emitted from levels which have sub-ps lifetimes. At this plunger distance, we might expect these lines to be fully Doppler shifted as they would decay in-flight well in advance of reaching the stopper. Yet, we observe these lines with their non-Doppler shifted energies suggesting that they are not being emitted in-flight but rather at rest. This might suggest that the 32S+27Al reactions are taking place within some thick piece of aluminium. Some of the lines show signs of having been shifted in energy to some extent which might indicate that not all of the ions are completely stopped. The observed lineshapes seem to be consistent with the short-lived states showing evidence of Doppler shift while the decay of the "longer-lived" states (~9 ps) are very sharp.

I haven't slept for about 24 hours so I may be talking absolute sh*te (famous Scottish word).

We will change the trigger and we stopped the run number 29

Run 33 Started

Plunger Run : 48

Supposed Distance = 10 um

position of the target = 10 um

micrometer = 6.5 um

Voltage = 7.957 V

Plunger off set 60 um

Which means we are running 60 um + 10 um (read from position window of plunger) = 70 um.

20:50   Observed beam dropped by a factor of 2 (1.5 enA on the beam dump). Asked the operator to improve beam. 

run stop 22:53 acquisition problem

Started after beam current was reduced by a factor of 2

plunger run # 116

Earlier:   CUP#6  100 enA

Now: CUP#6   50eNA

Beam dump 1.8 enA

Collimator  0.8 enA

The operator is asked to keep the beam dump current not larger than the present value.

Supposed Distance = 10 um

position of the target = 10 um

micrometer = 11.7 um

Voltage = 7.9 V

Plunger off set 60 um

Which means we are running 60 um + 10 um (read from position window of plunger) = 70 um.

Observed that detectors at theta 143 degrees count most.  Is this because they see beam dump?

The counting rate in 511 keV line for sum of the Ge detectors placed at 101, 117 and 143 degrees (with approved ACS). The largest intensity is visible for Ge at 143 degrees, lowest for 101 deg.

=============================== RING 101

Integration in spectrum user_ge_ring101_acceptedACS_clone.spc

RESULT : 3895

=============================== RING 117

Integration in spectrum user_ge_ring117_acceptedACS.spc

RESULT : 9392

=============================== RING 143

Integration in spectrum user_ge_ring143_acceptedACS.spc

RESULT : 15767

The Coulex of 197Au (279.5 keV ) line is visible in all rings with a comparable intensity:

=============================== RING 101

Integration in spectrum user_ge_ring101_acceptedACS_clone.spc

RESULT : 12491

=============================== RING 117

Integration in spectrum user_ge_ring117_acceptedACS.spc

RESULT : 11443

===============================RING 143

Integration in spectrum user_ge_ring143_acceptedACS.spc

RESULT : 10460

See pictures in the attachment:

1) stopper seen from the back (upstream view)

2) stopper  seen from the front (downstream view)

Mind the two small off-center dots. It is clear that the beam hits the edge of the frame.  This is possible because the 5 mm collimator has two small dots outside the 5 mm hole (the collimator  can be seen in the beam tube).

3) old target, upstream view

4)  new target, upstream view, after the stopper drove into it

5) new target, before it was mounted

6) the stopper, after the collision with the target. One of the visible rings is probably due to this collision, other traces probably reflect its complicated history earlier.

41_ge_single_theta 101,117,143 looks ok. No peakdeformation of 511, other gammas FWHM around half of that of511 - ok

ch4 in total rate EAGLE_0 arouns 2.1 kHz - ok

planger tollerace limits (green and blue horizontal markers) set far of the current distance, intantionally?

ch4 in total rate EGALE_) reached 2.4 kHz, beam intensity has been reduced to fit the required 2kHz.

at 11:34:50 sek on 11 march a spike in counting rate of some Ge detectors is observed. Buffers not cleared properly?

Again beam intensity gradually increased reaching 2.4 kHz ontotal rate EAGLE_0 ch4.  Beam intensity reduction requested. 1.8 kHz on ch4 after reduction.

14:12 beam intensity instability. Rapid increase of beam intensity - twice the previous value. Returned to normal after 4 minutes.

Large beam intensity instabilities from 14:10 till 14:40.  Beam intensity reduction requested. CH4 on Total rate EAGLE_0 returned to 1.9kHz. Intensity became stable.

Again beam intensity to high. Reduced to 2 kHz on ch4 GE

Beam stable, counting rate within limits, plunger distance within the given tollerance, gamma spectra ok, everything looks good but....

(yes there must be some "but"), refreshing of EAGLE_array_monitor.mat and NEDA_array_monitor.mat are out of sync. Mostly pure red colour is dysplayed. Not very usefull and (I suppose) missleading information.

For a split second a red "NO DATA" notification appeared in the top right corner of Counting rates dashboard.

It looks like it did not change anything in data collection.

started

source in the target position, as precisely as possible

At about 12:00, 13/03/2023 (about  17 hours after the beam was stopped), a measurement of activity of the beam line was performed using  FH 40G-L10 meter.

Radioctivity run 65 stopped before the measurement, radioactivity run  66 started after the measurement

Background level 120 ns/h

Target, stopper, the forward half of the target chamber - dismounted.

Approximate distance from the target position (upstream), approximate activity

10 cm    500 ns/h

25 cm    420 ns/h

35          350 ns/h

40          350 ns/h

50          200 ns/h

75          170 ns/h

run 66 started, radiocativity (background)