run control = 58

run data = xdaq 3303602776 Mar 12 08:01 needleRU_i58_0058_0024.caendat

RU = 7.88 MB/s

LF =   3.70 MB/s

plunger:

plunger run = 1530

actual distance =  262.6 um

micrometer =   266.8 um

position = 29.9 um

voltage =  3.308 V

Beam dump: 1 nA 

Colimator :  0.5 nA

run control = 58

run data =xdaq 1111949504 Mar 12 17:01 needleRU_i58_0058_0083.caendat

RU = 7.14 MB/s

LF =   3.46 MB/s

plunger:

plunger run = 1620

actual distance =  262.5 um

micrometer =   266.7 um

position = 29.8 um

voltage =  3.31 V

Beam dump: 0.7 nA 

Colimator :  0.5 nA

run control = 58

run data =xdaq  471656980 Mar 12 18:47 needleRU_i58_0058_0095.caendat

RU = 7.35 MB/s

LF =   3.50 MB/s

plunger:

plunger run = 1638

actual distance =  262.6 um

micrometer =   266.9 um

position = 29.8 um

voltage =  3.308 V

Beam dump: 0.7 nA 

Colimator :  0.5 nA

18:54 Run 58 stopped and 18:55 Run 59 started.

BEAM STOPPED.

END of EXPERIMENT.

Run 59 collects radioactivity.

-rw-rw-r-- 1 xdaq xdaq 295178920 Mar 12 18:59 needleLF_i58_0059_0000.adf
-rw-rw-r-- 1 xdaq xdaq 802293316 Mar 12 18:59 needleRU_i59_0059_0000.caendat

run control = 51

run data = /onlineNEDA_00/xData/hil099/run_0051_09-03-2023_16h25m16s/needleRU_i51_0051_0007.caendat

RU =  6.45MB/s

LF =   3.47 MB/s

plunger:

plunger run = 907

actual distance =  532.8 um

supposed distance = 532.7 um

micrometer =   533.0 um

position =  299.0 um

voltage =  1.657 V

Beam dump: 1 nA

Colimator :  0.6 enA

A list of runs, to be filled during the experiment is available here:
https://docs.google.com/spreadsheets/d/11tyI5pqYKJ-rMaYLuBIPZCClWz9Vu87W0R5AZc2srd8/edit?usp=sharing

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?

New target mounted.

106Cd 1 mg/cm2

181Ta  1.2 mg/cm2

Problems in alignment. Offset of 100 um, in spite of the fact that a gap is visible at this distance, and a hair could be moved in between stopper and the target.
Decided to close and pump anyway, after several attempts to improve the alignment.

Stopper same as before, slightly more stretched.

Beam energy measured:  148.2 MeV
Mind that this may be an overestimate (by ~1-2 MeV)

Operators tune beam on the target, collecting run 0023, trigger gg.

Beam on the target:

target+stopper+beam dump: 25 enA   (1.7 pnA)    not stable
5 mm collimator:  0.8 enA 

data taking continued with run 0023

Run 31 was stopped, because plunger distance is reduced to the mininimal one.
It takes time, in the meantime, after some break, run 32  was started, with no beam.

Run 37 stopped by itslelf at 15:43. This was noticed at about 16:10 by observing that grafana data rates do not change.

Stop at Run COntrol.  LF looks  disabled.

Attempt to restart normal way --> run 38  --> failed

Attempts to load topology failed.

Cannot any more refresh or load the Run COntrol web page (192.168.0.133:5000)

Grzes is trying to fix the problem remotely, while we are starting changing of the target....

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.

Run 59 collected data using gg trigger radioactivty

Run 60 trigger changed fropm gg to single g.

Just in the beginning a few minutes gg data could have been collected.

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)

Attached are the lists of files copied to the two 4 TB Bahadir's disks.

16/03/2023

Plunger chamber closed, some dummy target and stopper probably inside

run 72    eagle closed

run 73    right half of EAGLE completely opened

Three screenshots are attached:

Run 72  EAGLE closed

1)  Three rings.  There is significantly more 511 in ring 143 than in 117, 101

2) 5 detectors of ring 143. They all look similar to each other.

Run 73  right half of EAGLE opened

3) 5 detectors of ring 143.  The 3 detectors in the opened half hardly see 511 keV, the other 2 do.

Check with Colibri and a gamma scintillator probe ws done: largest activity is visible close to the target chamber, in the region starting at the edge of the chamber, end ending about 6 cm upstream.

About 80 gamma counts/s are seen there. The count rate decreases further upstream.

Background rate:  20 to 30 counts/s, 25 counts/s in Sala Fizykow.

Radioactivity line seen in the spectra,  with the same behaviour as 511:   743.5,  936 keV, 1434 keV.  These are lines from 52Cr, fed by beta+ decay of 52Mn.

Confirmed by Michain gamma-gamma.

52Mn can be produced in the a2pn channel in  the reaction 32S+27Al