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  nuclear two-photon decay, Page 12 of 12  Not logged in ELOG logo
ID Date Authorup Category Subject
  135   Fri Jun 25 21:47:24 2021 YuriAnalysisIdentification
Attached are two files with a proposed particle identification.
Different colors indicate different harmonic numbers
Attachment 1: Spectrum_possible_ID.png
Spectrum_possible_ID.png
Attachment 2: ID_2nd_Part.jpg
ID_2nd_Part.jpg
  147   Wed Jun 30 08:59:37 2021 YuriAccelerator70Se setting
X(9Be)=1.815 g/cm2 (adjusted in primary beam setting)

Gamma_t=1.3956
E(70Se)=368.499 MeV/u
Br(70Se)=6.21993 Tm

Pre-drilling:
E(78Kr)@Br(70Se)=337.461 MeV/u
E(SIS) = 415.792 MeV/u

Fragment Setting:
E(SIS) = 445.68 MeV/u
  209   Fri Jul 2 13:10:00 2021 YuriAcceleratorScrapers
12:46 moved the TOF detector scraper back to -11 mm
  214   Fri Jul 2 16:14:17 2021 YuriAcceleratorScrapers 4 72Br
Starting 15:15
The scrapers are moved very much close to each other to eliminate all background particles and leaving basically single ions injected for 72Br. Do not wonder, this means that also many empty files are created.
Scrapers:
E02DS3HG -> -40 mm
EEXDS1HG -> +5 mm
EEXDS2HA -> 0.0 mm

One sees probably a decay of 100 keV isomer, see the attached figure at about 18 s
We will run a few hours with this setting
Attachment 1: 1C28A49A-5FA1-4A81-8675-3ED9660FD793.png
1C28A49A-5FA1-4A81-8675-3ED9660FD793.png
  220   Fri Jul 2 20:33:44 2021 YuriAccelerator70Se setting with closed scrapers
We tune back to 70Se.
The scrapers stay closed at EEXDS2HA=0 mm, EEXDS1HG=+5 mm
"Single"-particle run
  16   Thu May 6 21:26:02 2021 Yuri et al.AcceleratorEnergies
gamma_t = 1.3955
Br(72Ge) corresponds to 6.79575 Tm
E (Kr) at Br(72Ge) = 392.9 MeV/u
ESIS = 467.45 MeV/u (pre-drilling, after 1.8 g/cm2 target)
ESIS = 440.98 MeV/u (final energy for 72Ge)

-during setup, a 20 mm offset in the TE line was observed. Beam centered via changing the Br of the beamline (~4 MeV/u up). Optimized pre-drilling transmission ~20% (with thick target)
  148   Wed Jun 30 09:04:50 2021 Yuri, MarkusAcceleratorStatus
1) Over night the source was conservated. It is being restarted now.
2) The approximated amount of Gas in this bottle shall allow for running until tomorrow morning (~24 h). There is still another bottle in reserve (1 l) and one reserve from GANIL (0.5 l).
3) Beam-time coordinator suggests to run until the gas is over, i.e., up into the weekend.
  153   Wed Jun 30 13:57:14 2021 Yuri, SergeyAcceleratorsextupoles + scraper positions
After setting up on 70Se
Sextupoles were adjusted to optimize the resolution of the 70Se peak. Set values are in the ESR logbook.
The SIS energy was shifted up to increase the number of 70Se.
Esis original = 445.68 MeV/u
Esis now = 451.68 MeV/u (+6 MeV/u)

See attached pictures

scrapers: 
GE01DS_HI =  -58mm
GE01DS_HA = +130mm (fully open)
GEEXDD2_S = -0.5mm
GEEXDS2HA = -11.2mm
Attachment 1: photo_2021-06-30_14-09-08.jpg
photo_2021-06-30_14-09-08.jpg
Attachment 2: photo_2021-06-30_14-02-25.jpg
photo_2021-06-30_14-02-25.jpg
  77   Sat May 8 17:29:54 2021 Yuri, Sergey, Wolfram, Michael, ShahabRunsrecording Kr decay measurement on NTCAP
Uc = 250mA
decay Kr 78, 476 MeV/u

in iso mode

NTCAP is running
  105   Sun May 9 13:53:07 2021 Yuri, Wolfram, Andrew, LilianaCalibrationChange of energy: Back as before
After looking at the spectrum it was concluded that the same isotopes, and no more, could be identified. 
Now we change the energy back to 441.7 MeV/u and will open the scrappers to see if Mn comes in. 

The picture shows the effect of going back to the previous energy and then the effect of opening the scrappers
Attachment 1: Screenshot_2021-05-09_13-59-36.png
Screenshot_2021-05-09_13-59-36.png
  167   Thu Jul 1 14:47:15 2021 Yury, HelmutAcceleratoradded high Brho scrapers
So far only scrapers for low Brho were used:
  GE01DS_HI = -58mm (arc from inside) and
  GEEXDS2HA = -11.2 (straight from outside)
We also want a cut on high Brho to avoid possible strange lines.

GE01DS_HA is limited in motion, at the maximum inside position (0.0 mm) there is no effect.

Next EEXDS1HG (aperture for ToF-detctor) in mm
120 -  completely out
 60 - no effect full beam
 45 -   "
 30 -   "
 20 -   "
 10 - very little beam remaining
  5 - gone
 12 - little beam
 14 - narow but little
 16 - narrow with small tail in left side
 20 - again like full
100 - full (as reference for the eye)

Then similar with E02DSHG in arc dipole in mm
 -130 - full
  -60 - full
  -40 - gone
  -45 - very tiny
  -55 - full
  -50 - less beam
  -52 - similar
  -53 - no difference
  -58 - looks like full

Now add EEXDS1HG again with -16mm, no difference, so keep both in.
==> we cut in arc from both sides and on straight secton from both sides
    Intensity does not look different to scrapers out. 
    It looks like a bit less 70Se in ESR then 1h before, but maybe other reason.
Attachment 1: ESR-scraper-overview.jpg
ESR-scraper-overview.jpg
Attachment 2: scrapers-used.JPG
scrapers-used.JPG
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