Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.
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Transcript of Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.
![Page 1: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/1.jpg)
Wire ScannersObservationsIn SPS & LHC
G. TRAD
Emittance working group26/08/2015
![Page 2: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/2.jpg)
Layout Quantification of the “crosstalk” effect experimentally with beam in
the SPS and LHC WS Crosstalk seen as an overall signal leakage to adjacent 25 ns slots. SPS WS studied are 419 and 519 (rotational), according to OP the
most frequently used. LHC WS studied are the 4 active ones, B1H2-B1V2-B2H1-B2V1
Quantification of the impact on trains emittance measurement
Implementation of a possible cure.
![Page 3: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/3.jpg)
SPSWS 416
![Page 4: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/4.jpg)
Measured SlotsSl
ot 1
Slot
2
Slot
3
Slot
4
Slot
5
Slot
6
Slot
7
Only 1 filled Bucket
Experimental SetupExample of a
measurement output
![Page 5: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/5.jpg)
Bringing these
points to zero
=>Subtracting the slot 1
profile considered as
noise of an empty bucket
![Page 6: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/6.jpg)
SPS.BWS.41677.H_ROTIN SCAN 1 IN SCAN 2 IN SCAN 3 IN SCAN 4
![Page 7: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/7.jpg)
SPS.BWS.41677.V_ROTIN SCAN 1 IN SCAN 2 IN SCAN 3
![Page 8: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/8.jpg)
FITTING
Example:'SPS.BWS.41677.H_ROT'
![Page 9: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/9.jpg)
𝑒− 𝑡𝜏
=13 ns
'SPS.BWS.41677.H_ROT'
13.7%
4.6%1.7%
6% ?
FITTING - SCANNER 1
![Page 10: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/10.jpg)
𝑒− 𝑡𝜏
=13.8 ns
'SPS.BWS.41677.V_ROT'
15.1%
5.3%3%3% ?
FITTING - SCANNER 2
![Page 11: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/11.jpg)
SPSWS 519
![Page 12: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/12.jpg)
SPS.BWS.51995.H_ROTIN SCAN OUT SCAN
Almost the same Intensity!
![Page 13: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/13.jpg)
SPS.BWS.51995.V_ROTIN SCAN OUT SCAN
![Page 14: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/14.jpg)
'SPS.BWS.51995.H_ROT'
Slot
1
Slot
2
Slot
3
Slot
4
Slot
5
Slot
6
Slot
7
As if WS slots have wrong delay:Even though it is not the croostalk originating from the system BW, The result is the same
WS
Slot
1
WS
Slot
2
WS
Slot
3
WS
Slot
4
WS
Slot
5
WS
Slot
6
WS
Slot
7
77.2 %
13 %5.4 %
2.8 % 1.75 % 1.2 %
FITTING - SCANNER 3
![Page 15: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/15.jpg)
FITTING - SCANNER 4
'SPS.BWS.51995.V_ROT'
79.8 %
13.1 %5.4 % 2.6 % 1.5 %
Same Issue for the vertical
scanner
![Page 16: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/16.jpg)
LHC
![Page 17: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/17.jpg)
Slot
1
Slot
2
Slot
3
Slot
4
Slot
5
Slot
6
Slot
7
Slot
179
3
Slot
179
4
Slot
179
5
Slot
179
6
Slot
179
7
Slot
179
8
Slot
179
9
Measured by :LHC.BWS.5R4.B1H2LHC.BWS.5R4.B1V2LHC.BWS.5L4.B2H1LHC.BWS.5L4.B2V1
Experimental Setup
![Page 18: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/18.jpg)
𝑒− 𝑡𝜏
=16.12 ns
‘LHC.BWS.5R4.B1H2'
21.07 %
4.4 % 2.4 %
![Page 19: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/19.jpg)
𝑒− 𝑡𝜏
=18.55 ns
‘LHC.BWS.5R4.B1V2'
26.95 %
4.75 %2.3%
![Page 20: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/20.jpg)
𝑒− 𝑡𝜏
=11.16 ns
‘LHC.BWS.5L4.B2H1'
10 %
3.9 % 2.6 %
![Page 21: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/21.jpg)
𝑒− 𝑡𝜏
=12.02 ns
‘LHC.BWS.5L4.B2V1'
11.6 %
4.7 % 3.2 %
![Page 22: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/22.jpg)
IMPACTA train of 72 bunches (25 ns spacing) has to be measured;
Assuming realistic but still conservative values:Mean Bunch intensity 1.2 e11 prot (+/- 5 %)Mean Bunch Emittance 2 e-6 m (+/- 8 %)
Due to this signal leakage between slots, an error on each bunch profile is introduced by the previous bunches in the train:
Slot 1 Slot 2 Slot 3 Slot 4
![Page 23: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/23.jpg)
30% spread peak to peak
20% spread peak to peak
![Page 24: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/24.jpg)
IMPACT
Slot 1 Slot 2 Slot 3 Slot 4
K1 * Prof S1K2 * Prof S1
K3 * Prof S1
A train of 72 bunches (25 ns spacing) has to be measured;
Assuming realistic but still conservative values:Mean Bunch intensity 1.2 e11 prot (+/- 5 %)Mean Bunch Emittance 2 e-6 m (+/- 8 %)
Due to this signal leakage between slots, an error on each bunch profile is introduced by the previous bunches in the train:
![Page 25: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/25.jpg)
IMPACT
Slot 1 Slot 2 Slot 3 Slot 4
K1 * Prof S2K2 * Prof S2
A train of 72 bunches (25 ns spacing) has to be measured;
Assuming realistic but still conservative values:Mean Bunch intensity 1.2 e11 prot (+/- 5 %)Mean Bunch Emittance 2 e-6 m (+/- 8 %)
Due to this signal leakage between slots, an error on each bunch profile is introduced by the previous bunches in the train:
![Page 26: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/26.jpg)
IMPACT
Slot 1 Slot 2 Slot 3 Slot 4
K1 * Prof S3
A train of 72 bunches (25 ns spacing) has to be measured;
Assuming realistic but still conservative values:Mean Bunch intensity 1.2 e11 prot (+/- 5 %)Mean Bunch Emittance 2 e-6 m (+/- 8 %)
Due to this signal leakage between slots, an error on each bunch profile is introduced by the previous bunches in the train:
![Page 27: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/27.jpg)
Quantified IMPACT
Error on the measured emittance in the slot,
falsed by crosstalk effects
By definition the first bunch has no induced from other
bunches since …it is the first
A Histogram of the obtained errors to
study the distribution patterns
![Page 28: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/28.jpg)
SPS.BWS.41677.H_ROT
Quantified IMPACT
![Page 29: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/29.jpg)
SPS.BWS.41677.V_ROT
Quantified IMPACT
Erro
r on
emitt
ance
det
erm
inati
on %
Bunch slots along the train Error on emittance determination %
![Page 30: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/30.jpg)
SPS.BWS.51995.H_ROT
Quantified IMPACT
Erro
r on
emitt
ance
det
erm
inati
on %
Bunch slots along the train Error on emittance determination %
![Page 31: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/31.jpg)
SPS.BWS.51995.V_ROT
Quantified IMPACT
Erro
r on
emitt
ance
det
erm
inati
on %
Bunch slots along the train Error on emittance determination %
![Page 32: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/32.jpg)
Quantified IMPACT
Scanner 416 H Rot 416 V Rot 519 H Rot 519 V Rot
Max Rel Error Up to 21 % Up to 24 % Up to 45 % Up to 48 %
SPS summary
![Page 33: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/33.jpg)
LHC.BWS.5R4.B1H2
Quantified IMPACT
Erro
r on
emitt
ance
det
erm
inati
on %
Bunch slots along the train Error on emittance determination %
![Page 34: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/34.jpg)
LHC.BWS.5R4.B1V2
Quantified IMPACT
Erro
r on
emitt
ance
det
erm
inati
on %
Bunch slots along the train Error on emittance determination %
![Page 35: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/35.jpg)
LHC.BWS.5R4.B2H1
Quantified IMPACT
Erro
r on
emitt
ance
det
erm
inati
on %
Bunch slots along the train Error on emittance determination %
![Page 36: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/36.jpg)
LHC.BWS.5R4.B2V1
Quantified IMPACT
Erro
r on
emitt
ance
det
erm
inati
on %
Bunch slots along the train Error on emittance determination %
![Page 37: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/37.jpg)
Quantified IMPACT
LHC summary
Scanner B1H2 B1V2 B2H1 B2V1
Max Rel Error Up 24 % Up to 30 % Up to 18% Up to 16%
![Page 38: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/38.jpg)
Solution
Bunch 1 Profile
Bunch 2 Profile
Bunch 3 Profile
Bunch 4 Profile
…………
Bunch n-1 Profile
Bunch n Profile
Obtained by Scan Measured Weights
Bunch 1 Profile
Bunch 2 Profile
Bunch 3 Profile
Bunch 4 Profile
…………
Bunch n-1 Profile
Bunch n Profile
Calculated
1K 1K 2K 3K 4…
K n
![Page 39: Wire Scanners Observations In SPS LHC G. TRAD Emittance working group 26/08/2015.](https://reader035.fdocuments.in/reader035/viewer/2022062317/5a4d1b677f8b9ab0599b133a/html5/thumbnails/39.jpg)
% SPS 51995 H Rotcrosstalk_weights=[0.772; 0.13; 0.054; 0.028 ;0.0175; 0.012];
deconvoluted_buckets=zeros(size(buckets));
for bucketID=1:size(deconvoluted_buckets,1)
previous_contributions=zeros(1,size(deconvoluted_buckets,2));
for j=1:length(crosstalk_weights) if bucketID-j>0 previous_contributions=previous_contributions+...
crosstalk_weights(j).*deconvoluted_buckets(bucketID-j,:); end end
deconvoluted_buckets(bucketID,:)=buckets(bucketID,:)-previous_contributions;
end
Easy cure, just a SW routine
Where should it be implemented? FEC or WS applications??