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Fixed, e768s, Sat Jul 20 01:02:10 2019, Serge & Franco, OTHER, General, , Night shift beam & resync
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timeline of run 116
00:xx resync Agata #13C
00:57 lost beam, back at full intensity at 01:12
01:30 lost beam, back at full intensity at 01:45
01:37 FP_CATS5 tripped, reset
01:43 resync Agata #13C
02:04 resync Agata #13C
02:20 lost beam, back at full intensity at 02:30
02:36 resync Agata #13C
03:45 Vamos rate down to 900 pps, checked that intensity on profiler is 1.1e7 so decided to continue
05:58 resync Agata #13C
06:55 Vamos rate at 1400 pps but diamond is decreasing since several hours: we had 17500 counts at midnight and now only 7500.
Checked beam rate on profiler and found 1.8e7 so indeed it is the diamond efficiency that is going down steeply |
Fixed, e768s, Sat Jul 20 04:30:42 2019, Serge & Franco, RUN, General, LiF, screenshots run 116 @ 02h00 14x
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Fixed, e768s, Sat Jul 20 04:47:49 2019, Serge & Franco, RUN, General, LiF, screenshots run 116 @ 04h30 15x
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| The rate in the diamond was decreasing even if the rate in VAMOS was more or less constant. Now it seems stabilized. |
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Fixed, e768s, Sat Jul 20 05:58:18 2019, Franco, OFFLINE, General, , Time calibration for MG10_X
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Attached a tentative time calibration for the square MG10_X from run 89 (to be checked!).
Even applying the calibration the spectrum E_TOF for MG10 (run 115) displays many structures. |
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Fixed, e768s, Sat Jul 20 08:01:06 2019, Nikola, ONLINE, General, , screenshots run 116 @ 08h00 22x
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Fixed, e768s, Sat Jul 20 09:20:35 2019, Nikola, ONLINE, General, , screenshots run 116 @ 09h20 22x
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Fixed, e768s, Sat Jul 20 10:50:01 2019, Nikola, ONLINE, General, , End of run 116 (beam problem) -> screenshots run 116 end @ 10h40 22x
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1. A monitor of the primary beam failed and the astreinte had to be call (PCP did it).
2. The H2O cold box went in default. The cold water for AGATA digitizer; vamos crates and CTA went up to 25 deg!
Reset..... waiting that it goes back to 17deg in the cave circuit |
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Fixed, e768s, Sat Jul 20 11:33:01 2019, Christian, OTHER, General, , Previous Papers - gamma decays from states in the 4-MeV region
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This search was triggered by our lack of seeing the 3958keV line at the expected level. 2689 keV line observed (runs 112,115,116) as 55-60 counts. Expected yield in 3958 keV line based on 80:20 branching and 1.5:1.0 efficiency is 10 counts. We see (at most) 2 in the full photo-peak for this line. (Theses two counts are also lower than expected by about 20 keV.)
The 4.20 MeV to 0.24MeV line in the attached spectrum (p. 2 of J.M.Davidson & M.L.Roush) is one of three spectra by them, on which this branching ratio was based. With the level of detail in these spectra, I think it is fair to question this result. NNDC and TUNL data for branching ratios of this state is entirely based on this paper.
Action: other branching ratios in this region should be checked in this paper to see whether there could be other dubious branchings. |
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Fixed, e768s, Sat Jul 20 12:06:00 2019, Christian, OTHER, General, , Previous Papers - gamma decays from states in the 4-MeV region
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| Further to the previous post on gamma-ray lines, attached is Kanungo's paper on doppler-attenuation measurement of the 4033 line for lifetime measurement. The lower-energy lines are, however, not included in the figures. |
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Fixed, e768s, Sat Jul 20 12:57:41 2019, Christian, OTHER, General, , Previous Papers - gamma decays from states in the 4-MeV region
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2019 paper by Hall, Bardayan, et al., gamma decays of 4.14 and 4.20 states, g-g-t triple coincidences.
Abstract:
The 15O(α,γ)19Ne reaction is responsible for breakout from the hot CNO cycle in Type I x-ray bursts. Understanding the properties of resonances between Ex = 4 and 5 MeV in 19Ne is crucial in the calculation of this reaction rate. The spins and parities of these states are well known, with the exception of the 4.14- and 4.20-MeV states, which have adopted spin-parities of 9/2− and 7/2−, re- spectively. Gamma-ray transitions from these states were studied using triton-γ-γ coincidences from the 19F(3He,tγ)19Ne reaction measured with GODDESS (Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies) at Argonne National Laboratory. The observed transitions from the 4.14- and 4.20-MeV states provide strong evidence that the Jπ values are actually 7/2− and 9/2−, respectively. These assignments are consistent with the values in the 19F mirror nucleus and in contrast to previously accepted assignments.
Noteworthy is that they also don't observe the 3.96MeV transition from the 4.20MeV state, consistent with our observations.
No data is given on the 4.033 MeV state [potentially see further discussion in the corresponding PhD thesis].
From the data, however, it would seem that the (3He,t) reaction does not really populate the 4033 state [otherwise, the 4033 transition should have been seen in Figure 4]. |
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Fixed, e768s, Sat Jul 20 14:00:22 2019, OttoRun, RUN, General, LiF, Run117
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*************************
Run : 117
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Start at 2019-07-20 13:59:36.817451
H2O cold box reset. took a while to reach below 20deg in cave.
beam back.
Stop at 2019-07-20 16:47:36.880786
Stop comment: VXI VAMOS LOST |
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Fixed, e768s, Sat Jul 20 14:21:22 2019, Nikola, ONLINE, General, , screenshots run 117 @ 14h20 22x
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Fixed, e768s, Sat Jul 20 14:32:18 2019, Nicolas, BEAM, General, LiF, Beam profile & intensity (run 117 @ 14h30)
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Beam intensity: 1.4e7 pps
VAMOS: ~ 1200 |
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Fixed, e768s, Sat Jul 20 17:00:19 2019, OttoRun, RUN, General, LiF, Run118
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*************************
Run : 118
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Start at 2019-07-20 16:59:33.086411
Start after the overtemperature of VXI VAMOS.
Stop at 2019-07-20 21:11:28.272749
Stop comment: Vamos VXI offline |
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Fixed, e768s, Sat Jul 20 17:03:23 2019, mugast, RUN, General, LiF, Run 117 stopped
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| Run 117 stopped because VAMOS VXI went offline |
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Fixed, e768s, Sat Jul 20 17:06:12 2019, mugast, RUN, General, LiF, Run 118 Scaler
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| Start run 118 |
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Fixed, e768s, Sat Jul 20 19:12:58 2019, Faïrouz & Sylvain, RUN, General, LiF, Run 118 screenshots @ 19h14 20x
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Fixed, e768s, Sat Jul 20 19:21:56 2019, Marlene, Nicolas, Christian, Fairouz, OFFLINE, General, , Trying to understand AGATA g-ray yields
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goal: we want to check whether the yields of the 1297.7 keV (from 19Ne 1536, 3/2+, l=1 state) and 1340 keV (from 19Ne 1615, 3/2-, l=2 state) g-ray lines is compatible with what we expect from x-sec calculations
conditions: we consider runs 112, 115 and 116
observations:
N(1297) = 17 g-rays
N(1340) = 23 g-rays
remarks:
Given x-sec from mirror nucleus (Francois 15N(7Limt) paper) we expect N(1340) >~ N(1297)
ingredients:
1. beam normalization
We use the TAC_FPMW_HF as a proxy. During the same time we integrate the prompt peak and compare the integrated OR VAMOS scaler, we find Scaler(OR VAMOS)/N(TAC) = 193.
We use the comparison of the OR VAMOS (pps) and the beam profiler (pps), we find profiler/OR VAMOS = 1e4
We obtain (2.17e5 + 6.44e4 + 3.52e5)*193*1e4 = 1.2 e12 15O incident particles (at profiler position!)
2. target thickness -> known to be 1.25 mg/cm2 of LiF (RBS measurement)
N(Li) = 1.25e-3 / (19+7) * 6.02e23 at/cm2
3.efficiencies
AGATA @ 1.3 MeV -> 7.5 %
VAMOS intrinsic -> 67 % (Eff_Check.C macro applied to run 116)
MUGAST -> 50 % (lab, geometry), needed because MUGAST is the main trigger
4. 19Ne charge state
we assume 40 % for 9+
5. g-ray branching ratio -> taken from NNDC
6. cross-section
we calculate differential cross section for the 1536-keV 19Ne state (FRESCO, FR-DWBA)
-> at 0 deg, ds/dW =
-> integrated x-sec in VAMOS acceptance (4 deg (lab) -> 20 deg (cm)) = 445 micro barn (C2Sa = 1)
-> taking into account know spectroscopic factor form analog state -> 89 micro barn
Conclusion:
for the 1536-keV 19Ne state we obtain 30 g-rays, instead of 17.
Discussion:
This factor of two could be well within the mirror symmetry assumption. However it seems it is also the case for the 1615-keV 19Ne state, so would not it be a systematic error with a factor of two missing somewhere (beam transmission between the profiler and the target? deficiencies?)? |
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Fixed, e768s, Sat Jul 20 19:23:37 2019, Christiqn, OFFLINE, General, LiF, Ex in 19F from run 72
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Data: Total integral for peak region around 4 MeV in 19F during run 72:
~35 average peak height over 27 bins = 945 counts. Note that this includes what looks like background in the spectrum. In reality, however, this should be considered part of the yield, because the 1.5 MeV , 4.0 MeV peak, and 5.5 MeV peaks just about touch, and are about the same intensity. So realistic integral is approximately the number of counts between 2.8 and 4.8 MeV.
Comparison to previously observed cross section [F. de O.]:
Ex = 3.999+4.033 [19F]
d-sigma/d-Omega ~ 3.5mb/sr (approximately constant over the range of 0-20 deg c.m.
d-Omega = 0.061 sr [over 0-20 deg. c.m]
=>
sigma = 0.21mb
Assumed efficiencies:
e_MUGAST = 0.5
e_charge-state = 0.5
e_VAMOS = 0.8 [intrinsic]
d_tgt = 337ug/cm2 [7Li component]
Run72:
beam = 1e8pps
run time = 2.4h
Total reaction rate = 2.2k/h
Coincidence detection rate = 440/h
Coincidence detection yield over 2.4h [run72] = 1056
Consistent with the observation for MUGAST-VAMOS coincidences for the run. |
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Fixed, e768s, Sat Jul 20 19:24:31 2019, Faïrouz & Sylvain, RUN, General, LiF, Beam intensity is decreasing.
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The beam intensity decreased by half since 19h00 (600 in Vamos-or)due to the primary beam.
The operators are working on it since.
The intensity of 10^7 pps came back at 8 pm.
Intensity measurement with the profiler 1.1x10^7 pps for Or-Vamos=1100 |
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