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MUST2
SAMURAI_2018
S3-LEB-LPC
SUPERNEMO
MUGAST
EXPAND
SCALP
GALATRON
HiCARI
VELO
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 Mon Jul 22 16:54:33 2019, Marlène, Franck, François & Nicolas, e768s, BEAM, General, Fixed, , Cheking beam transmission from G1 profiler to VAMOS
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 Tue Jul 23 14:33:03 2019, Marlène, Yorick, Faïrouz & Nicolas, e768s, BEAM, General, Fixed, , Cheking beam transmission from G1 profiler to VAMOS 
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Message ID: 5287
Entry time: Tue Jul 23 14:33:03 2019
In reply to: 5264
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| Author: |
Marlène, Yorick, Faïrouz & Nicolas |
| ExpNbr: |
e768s |
| Type: |
BEAM |
| Category: |
General |
| Status: |
Fixed |
| Target-Source: |
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| Subject: |
Cheking beam transmission from G1 profiler to VAMOS |
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Goal:
Estimate beam transmission from profiler to VAMOS (FP)
We question whether the factor of two found yesterday (VAMOS/Profiler ~ 0.5) could be due:
1. to an incorrect measurement of the beam intensity with the profiler
2. a charge state equilibration in the target (LISE++ calculation indicates 8+/7+ = 85%/15%)
Same conditions as yesterday:
1. Beam intensity is reduced with the pepper pot 1/9 and by closing slits after the 15O target production and the accelerators so that the beam quality (emittance, etc...) is not affected.
2. VAMOS plate is removed to allow the direct beam detection
Results:
We measure in VAMOS with the LiF target and with the target ladder totally removed. In the latter case, direct beam 15O(8+) is sent in VAMOS and no charge state effect enter into the game.
1. Beam intensity at G1 profiler ~ 6.5e4 pps
VAMOS (FP) + no target ~ 3.8e4 pps
2. Beam intensity at G1 profiler ~ 3.8e4 pps
VAMOS (FP) + thick LiF (nb 1) ~ 2.0e4 pps
Discussion:
We find the same results as yesterday, e.g. a factor of two attenuation between the profiler and VAMOS. If part of this loss would happen in the pipe/target/MUST2 mask, this should be observed in AGATA which is not the case. Could it be that the PPAC in VAMOS is not as efficient as announced at the beginning of the campaign (98%)? This must be checked when we get beam back later on.
Note:
While doing the above measurement, we observed a factor of 3 loss between profiler AR.Gaz13 and G1.Gaz31. Numbers follows:
L3.GAZ42 AR.GAZ13 G1.GAZ31
2.1e4 1.5e4 4.1e3
1.4e5 1.0e5 2.5e4
??? 1.8e5 6.5e4 |
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