| Status |
ExpNbr |
Date |
Author |
Type |
Category |
Target-Source |
Subject |
| Fixed | e768s |
Sun Jul 21 22:40:23 2019 |
Kseniia & Nicolas | BEAM | General | N/A | beam check run121 |
| best intensity ever: 2.2e7 pps |
| Fixed | e768s |
Mon Jul 22 00:13:08 2019 |
Faïrouz & Sylvain | RUN | General | LiF | Screenshots run 121 @00h13 |
|
| Fixed | e768s |
Mon Jul 22 02:07:44 2019 |
Faïrouz & Sylvain | BEAM | General | LiF | Run 121 : Beam profile |
| Status at 2:05 AM |
| Fixed | e768s |
Mon Jul 22 04:15:53 2019 |
Faïrouz & Sylvain | RUN | General | LiF | Beam intensity & profile & scalers |
|
| Fixed | e768s |
Mon Jul 22 05:03:59 2019 |
Faïrouz & Sylvain | RUN | General | LiF | Screenshots run 121 @05h04 |
|
| Fixed | e768s |
Mon Jul 22 05:12:13 2019 |
OttoRun | RUN | General | LiF | Run122 |
*************************
Run : 122
*************************
Start at 2019-07-22 05:11:56.885037
beam intensity after optimization 2.0e7 pps
OR VAMOS ~ 1500 Hz
Target: 1.25 mg/cm2 (nb 1) 7LiF
Triggers
MUGAST (backward, MM, 90 deg)
VAMOS %100
BaF2 %100
Stop at 2019-07-22 07:01:32.414292
Stop comment: stop run 122. We wait for Bertrand to optimize the beam centering and size. |
| Fixed | e768s |
Mon Jul 22 05:16:22 2019 |
Faïrouz & Sylvain | RUN | General | LiF | Stop run 121 because problems of AGATA trigger validation |
| The run 121 has to be stopped because problems of AGATA trigger validation due to very high request rate of AGATA >=85K |
| Fixed | e768s |
Mon Jul 22 05:19:36 2019 |
Faïrouz & Sylvain | RUN | General | LiF | Start new run 122 |
Start new run 122. AGATA validation was recovered.
BUT the AGATA request rate is increasing very quickly!!! The OR-AGATA increased up to ~32000.
OR MUGAST : 371
OR AGATA : 31856
OR VAMOS : 1545 |
| Fixed | e768s |
Mon Jul 22 05:30:37 2019 |
Faïrouz & Sylvain | RUN | General | LiF | CF put because AGATA went crazy |
CF put because AGATA went crazy.
The beam profile is shifted in comparison to the initial profile at midnight. The beam is touching somewhere.
We asked the beam operators to try to center the beam. |
| Fixed | e768s |
Mon Jul 22 06:14:38 2019 |
Faïrouz & Sylvain | RUN | General | LiF | Run 122 with more centered beam profile |
Even with a more centered beam profile, AGATA request triggers is increasing too much and too fast!!! after 5 mn run, we are already at 100khz!!!
Need Bertrand to solve the situation. |
| Fixed | e768s |
Mon Jul 22 06:32:40 2019 |
Faïrouz & Sylvain | RUN | General | LiF | We put the Faraday cup because AGATA can not cope with the very high counting rate (>110kHz) |
We will call Emmanuel & Bertrand.
We stopped the run 122, waiting for Bertrand to come and work on the beam size and focalization. |
| Fixed | e768s |
Mon Jul 22 07:48:03 2019 |
OttoRun | RUN | General | LiF | Run123 |
*************************
Run : 123
*************************
Start at 2019-07-22 07:47:55.021346
beam intensity after optimization 2.0e7 pps
OR VAMOS ~ 1500 Hz
Target: 1.25 mg/cm2 (nb 1) 7LiF
Triggers
MUGAST (backward, MM, 90 deg)
VAMOS %100
BaF2 %100
Stop at 2019-07-22 08:16:58.580316
Stop comment: End of beam position optimization |
| Fixed | e768s |
Mon Jul 22 08:23:02 2019 |
Christian - Bertrand, Sylvain, Frank, Francois | BEAM | General | LiF | Beam adjustment notes |
| Adjustment of beam position, moved up by approximately 15mm on VAMOS FP, down by 2mm on target. AGATA rate reduced to normal, about 4k after 5 min equilibration, no substantial satellite seen in direct beam on VAMOS FP. See separate entry for detailed discussion. Note, however that while beam intensity measurement is 2.1e7, VAMOS trigger on reaction setting is approximately 1100. |
| Fixed | e768s |
Mon Jul 22 08:26:07 2019 |
OttoRun | RUN | General | LiF | Run124 |
*************************
Run : 124
*************************
Start at 2019-07-22 08:18:38.043920
Restart after beam position optimization by Bertrand to reduce AGATA rate
(probably from beam hitting the target frame)
Beam position in VAMOS FP moved by +15 mm in vertical
-> - 2 mm in vertical on target
Beam intensity: 2.0e7 pps
OR VAMOS ~ 1100 Hz
So the VAMOS/intensity ratio has changed
Target: 1.25 mg/cm2 (nb 1) 7LiF
Triggers:
MUGAST (backward, MM, 90 deg)
VAMOS %100
BaF2 %100
Rates:
FAG: 160
MUGAST: 150
OR AGATA: 1400
OR VAMOS: 1100
Stop at 2019-07-22 10:54:58.589478
Stop comment: stop to recover MG3X |
| Fixed | e768s |
Mon Jul 22 08:28:00 2019 |
mugast | OTHER | General | LiF | Scalers at start of run124 |
|
| Fixed | e768s |
Mon Jul 22 08:29:19 2019 |
Faïrouz, Sylvain, Francois et Franck, Bertrand | BEAM | General | LiF | Beam profile updated |
To solve the very high counting rate observed on AGATA (and on MUST2 with a lesser degree), the beam was retuned.
After inspection of the beam profile in VAMOS, Bertrand tuned the vertical steerers G1.DC21-VE (from 0.5 -> 0.0A). The consequence is a shift of 2mm in vertical position at the target position.
Everything seems back to normal. |
| Fixed | e768s |
Mon Jul 22 09:40:06 2019 |
Franck, François, Adrien, Jérémy, Nicolas | ONLINE | General | LiF | Screenshots run 124 |
|
| Fixed | e768s |
Mon Jul 22 10:01:12 2019 |
Franck, François D | BEAM | General | LiF | Beam profile |
Slight shift in vertical +1 mm (with respect to this morning at 8:30)?
Intensity = 1.7e7 pps |
| Fixed | e768s |
Mon Jul 22 10:10:02 2019 |
Christian | OTHER | General | | Previous Papers - alpha-branching ratios for states in the 4-MeV region |
Branching ratio data overview from Tan et al. (PRL 2007, attached):
Ex/MeV B_alpha
4.03 2.9(21)e-4
4.14/4.20 1.2(5)e-3
4.38 1.2(3)e-3
4.55 0.07(2)
In the spectra so far, we are very clearly seeing the 4.14/4.20 MeV doublet. We may also be seeing some indication of the 4.38, 4.55 and/or 4.60 MeV states above 4 MeV (4.14, 4.27, and 4.36 MeV respectively, as dominant lines). Note that we have no alpha-branching-ratio data for the 4.60MeV state, and that most likely the gamma-ray events we currently see above 4MeV are the 4.14MeV and 4.36MeV lines (4.38 and 4.60 MeV states).
Comments to lifetimes from Mythili et al., (PRC 2008, attached). The relevant lifetimes are for the states between 4.14 and 4.55. Only dominant errors are given, for details, see attached table:
Pre-2008 Mythili
Ex/MeV lifetime/fs lifetime/fs
4.14 18(+2/-3) 14(4)
4.20 43(+12/-9) 38(+20/-10)
4.38 5(+3/-2) <5.4 (95% CL)
4.55 15(+11/-5) 19(4)
In combination:
4.38 MeV: Branching ratio is fairly well known. Lifetime is very poorly known, if at all. We have 7 counts so far (provisional), in the 4.14 MeV peak after about 3 days of beam on target.
4.55 MeV: Branching ratio is fairly well known. Lifetime is fairly well known, but it is not clear that we see this decay.
4.14/4.20: Lifetimes is known reasonably well for 4.14, poorly for 4.20, and differ by about a factor of 2-4 (within error). Branching ratio is only known in combination between the two. This complicates normalisation to these two states greatly, as we would in principle have to assume any combination of this contribution from 4.14, 4.20, or combined. In their paper (Tan 2007), they do state for this measurement that: "The measured􏰑 peak [in the alpha-spectrum] seems to be lower in energy than the simulated one, indicating that these decay events are more likely from the 4.14-MeV state.". Looking at the spectrum they refer to, however, I would not say that this is in any way a clear cut argument (and they do state it with some hesitation).
In summary: because of the overlap of the 4.14 and 4.20 states in the branching ratio data [which I should admit that I had missed when investigating the previous data and results earlier] it will be much harder than expected to cross check normalisation of the data based on the observed lifetimes and alpha branching ratios for 19Ne resonances.
|
| Fixed | e768s |
Mon Jul 22 11:16:09 2019 |
OttoRun | RUN | General | LiF | Run125 |
*************************
Run : 125
*************************
Start at 2019-07-22 11:11:08.167773
Beam intensity: 2.0e7 pps
OR VAMOS ~ 1100 Hz
So the VAMOS/intensity ratio has changed
Target: 1.25 mg/cm2 (nb 1) 7LiF
Triggers:
MUGAST (backward, MM, 90 deg)
VAMOS %100
BaF2 %100
Rates:
FAG: 160
MUGAST: 150
OR AGATA: 1400
OR VAMOS: 1100
MG3 pedestal suppression between 0 and 6800
Stop at 2019-07-22 15:16:35.174290
Stop comment: Stop to check beam intensity with vamos |