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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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4

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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5

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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6

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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7

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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8

09/06/11: 1st fill with octupoles at injection and it was a good one! (3/5)

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9

09/06/11: 1st fill with octupoles at injection and it was a good one! (4/5)

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10

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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12

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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18

24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (7/?)

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19

24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (8/?)

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20

24/06/11: 1236b for the 1st time in LHC and seems that transverse emittance BU was observed!!! (9/?)

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21

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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22

LHC 08:30 meeting on 29/06/11 (1/?)

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23

LHC 08:30 meeting on 29/06/11 (2/?)

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24

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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26

1-batch BU seen on 06/08/11 (2/7)

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27

1-batch BU seen on 06/08/11 (3/7)

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28

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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29

1-batch BU seen on 06/08/11 (5/7)

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30

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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31

1-batch BU seen on 06/08/11 (7/7)