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1
08/06/11: Bad fill again! The 1st with 144 b injections (1/5)
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2
08/06/11: Bad fill again! The 1st with 144 b injections (2/5)
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3
08/06/11: Bad fill again! The 1st with 144 b injections (3/5)
18:06:44 18:08:00
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08/06/11: Bad fill again! The 1st with 144 b injections (4/5)
Low-intensity tune
Laslett tune shift
-Qs appearing!
Green = 18:06:53Blue= 18:07:05
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08/06/11: Bad fill again! The 1st with 144 b injections (5/5)
=> Seems really to come from mode m = - 1 => Use octupoles the
next time (~ - 10 A)!
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09/06/11: 1st fill with octupoles at injection and it was a good one! (1/5)
Ioct finally put at 6.5 A at injection
after some tests with a single bunch!
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09/06/11: 1st fill with octupoles at injection and it was a good one! (2/5)
1st fill (# 1865) with Ioct = 6.5 A at
injection
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09/06/11: 1st fill with octupoles at injection and it was a good one! (3/5)
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09/06/11: 1st fill with octupoles at injection and it was a good one! (4/5)
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09/06/11: 1st fill with octupoles at injection and it was a good one! (5/5)
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11
10/06/11: Q” meas. without and with octupoles (see LHC 08:30 meeting on 11/06/11)
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24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (1/?)
Since 09/06/11, octupoles are used at injection (-6.5 A) and transverse
emittance blow-up was not observed anymore
Is the BU confirmed? => Doubt in the ELogBook that the measured is
good…
Did we have the Ioct at -6.5 A? => Seems yes
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13
24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (2/?)
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14
24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (3/?)
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15
24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (4/?)
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16
24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (5/?)
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17
24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (6/?)
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24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (7/?)
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24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (8/?)
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24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (9/?)
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24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (10/?)
=> According to BBQ, we don’t see huge coherent motion which
was usually associated to erratic transverse emittance BU. In other
words, looking only at this signal, I would not have said that strong
emittance BU was observed… To be followed up.
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LHC 08:30 meeting on 29/06/11 (1/?)
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LHC 08:30 meeting on 29/06/11 (2/?)
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LHC 08:30 meeting on 29/06/11 (3/?)
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25
1-batch BU seen on 06/08/11 (1/7)
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1-batch BU seen on 06/08/11 (2/7)
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1-batch BU seen on 06/08/11 (3/7)
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1-batch BU seen on 06/08/11 (4/7)
The transverse emittance BU on the 3rd batch seems to be correlated to some coherent
motion in V
Why? The octupoles were
ON… The intensity per bunch was just increased to ~
1.25E11 p/b. There was some vacuum activity also…
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1-batch BU seen on 06/08/11 (5/7)
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1-batch BU seen on 06/08/11 (6/7)
The perturbed emittances are ~ constant over many hours => Can we explain this emittance BU by a
factor ~2-3 in V? => Action discussed at the last Ecloud
meeting
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1-batch BU seen on 06/08/11 (7/7)