Ge rates increasing, similar to what it was 24h before. Asking to decrease beam intensity by a factor of 2.

Attached Ge spectra before decreasing.
 

Before decreas beam current was 1.75enA, afterwards 1.1enA.

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.

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.

/onlineNEDA_00/xData/hil099/run_0045_07-03-2023_09h14m17s/needleRU_i45_0045_0027.caendat

/onlineNEDA_00/xData/hil099/run_0045_07-03-2023_09h14m17s/needleLF_i44_0045_0010.adf

Since 2:32 increased counting rate observed:

Sinde 3:45 decrease to 1.5 kHz ch4.

run control = 48

/onlineNEDA_00/xData/hil099/run_0048_08-03-2023_01h08m57s/needleRU_i48_0048_0007.caendat
run data =

RU =  8.69 MB/s

LF =   3.79 MB/s

Eagle Rated ch4: around 2.3 kHz

plunger: (2:48)

plunger run = 514

actual distance =  382.7 um

supposed distance = 382.7 um

micrometer =   383.5 um

position =  149.8 um

voltage =  2.144 V

Beam dump =  1.5 nA

Collimater=  0.5 nA

Count rates are still a bit high (~2.6kHz for EAGLE det4). Ge spectra looks fine compared to earlier ones.

From 13:00 the rate of the Ge [the chanel 4] is a bit higher (~2.15 kHz). And also the rate of other detectors.

the rates of detectors are still a bit higher

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.

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.

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.

Plunger run files for later to calculate error in the distance

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)